Tag Archives: China

Nano-photosynthesis in your brain as a stroke treatment?

A May 19, 2021 news item on phys.org sheds some light on a new approach to stroke treatments,

Blocked blood vessels in the brains of stroke patients prevent oxygen-rich blood from getting to cells, causing severe damage. Plants and some microbes produce oxygen through photosynthesis. What if there was a way to make photosynthesis happen in the brains of patients? Now, researchers reporting in ACS’ Nano Letters have done just that in cells and in mice, using blue-green algae and special nanoparticles, in a proof-of-concept demonstration.

A May 19, 2021 American Chemical Society (ACS) news release, which originated the news item, provides more information on strokes and how this new approach may prove useful,

Strokes result in the deaths of 5 million people worldwide every year, according to the World Health Organization. Millions more survive, but they often experience disabilities, such as difficulties with speech, swallowing or memory. The most common cause is a blood vessel blockage in the brain, and the best way to prevent permanent brain damage from this type of stroke is to dissolve or surgically remove the blockage as soon as possible. However, those options only work within a narrow time window after the stroke happens and can be risky. Blue-green algae, such as Synechococcus elongatus, have been studied previously to treat the lack of oxygen in heart tissue and tumors using photosynthesis. But the visible light needed to trigger the microbes can’t penetrate the skull, and although near-infrared light can pass through, it is insufficient to directly power photosynthesis. “Up-conversion” nanoparticles, often used for imaging, can absorb near-infrared photons and emit visible light. So, Lin Wang, Zheng Wang, Guobin Wang and colleagues at Huazhong University of Science and Technology wanted to see if they could develop a new approach that could someday be used for stroke patients by combining these parts — S. elongatus, nanoparticles and near-infrared light — in a new “nano-photosynthetic” system.

The researchers paired S. elongatus with neodymium up-conversion nanoparticles that transform tissue-penetrating near-infrared light to a visible wavelength that the microbes can use to photosynthesize. In a cell study, they found that the nano-photosynthesis approach reduced the number of neurons that died after oxygen and glucose deprivation. They then injected the microbes and nanoparticles into mice with blocked cerebral arteries and exposed the mice to near-infrared light. The therapy reduced the number of dying neurons, improved the animals’ motor function and even helped new blood vessels to start growing. Although this treatment is still in the animal testing stage, it has promise to advance someday toward human clinical trials, the researchers say.

The authors acknowledge funding from the National Key Basic Research Program of China, the National Natural Science Foundation of China, the Chinese Ministry of Education’s Science and Technology Program, the Major Scientific and Technological Innovation Projects in Hubei Province, and the Joint Fund of Ministry of Education for Equipment Pre-research.

Here’s a link to and a citation for the paper,

Oxygen-Generating Cyanobacteria Powered by Upconversion-Nanoparticles-Converted Near-Infrared Light for Ischemic Stroke Treatment by Jian Wang, Qiangfei Su, Qiying Lv, Bo Cai, Xiakeerzhati Xiaohalati, Guobin Wang, Zheng Wang, and Lin Wang. Nano Lett. 2021, 21, 11, 4654–4665 DOI: https://doi.org/10.1021/acs.nanolett.1c00719 Publication Date:May 19, 2021 © 2021 American Chemical Society

This paper is behind a paywall.

Memristors, it’s all about the oxides

I have one research announcement from China and another from the Netherlands, both of which concern memristors and oxides.

China

A May 17, 2021 news item on Nanowerk announces work, which suggests that memristors may not need to rely solely on oxides but could instead utilize light more gainfully,

Scientists are getting better at making neuron-like junctions for computers that mimic the human brain’s random information processing, storage and recall. Fei Zhuge of the Chinese Academy of Sciences and colleagues reviewed the latest developments in the design of these ‘memristors’ for the journal Science and Technology of Advanced Materials …

Computers apply artificial intelligence programs to recall previously learned information and make predictions. These programs are extremely energy- and time-intensive: typically, vast volumes of data must be transferred between separate memory and processing units. To solve this issue, researchers have been developing computer hardware that allows for more random and simultaneous information transfer and storage, much like the human brain.

Electronic circuits in these ‘neuromorphic’ computers include memristors that resemble the junctions between neurons called synapses. Energy flows through a material from one electrode to another, much like a neuron firing a signal across the synapse to the next neuron. Scientists are now finding ways to better tune this intermediate material so the information flow is more stable and reliable.

I had no success locating the original news release, which originated the news item, but have found this May 17, 2021 news item on eedesignit.com, which provides the remaining portion of the news release.

“Oxides are the most widely used materials in memristors,” said Zhuge. “But oxide memristors have unsatisfactory stability and reliability. Oxide-based hybrid structures can effectively improve this.”

Memristors are usually made of an oxide-based material sandwiched between two electrodes. Researchers are getting better results when they combine two or more layers of different oxide-based materials between the electrodes. When an electrical current flows through the network, it induces ions to drift within the layers. The ions’ movements ultimately change the memristor’s resistance, which is necessary to send or stop a signal through the junction.

Memristors can be tuned further by changing the compounds used for electrodes or by adjusting the intermediate oxide-based materials. Zhuge and his team are currently developing optoelectronic neuromorphic computers based on optically-controlled oxide memristors. Compared to electronic memristors, photonic ones are expected to have higher operation speeds and lower energy consumption. They could be used to construct next generation artificial visual systems with high computing efficiency.

Now for a picture that accompanied the news release, which follows,

Fig. The all-optically controlled memristor developed for optoelectronic neuromorphic computing (Image by NIMTE)

Here’s the February 7, 2021 Ningbo Institute of Materials Technology and Engineering (NIMTE) press release featuring this work and a more technical description,

A research group led by Prof. ZHUGE Fei at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) developed an all-optically controlled (AOC) analog memristor, whose memconductance can be reversibly tuned by varying only the wavelength of the controlling light.

As the next generation of artificial intelligence (AI), neuromorphic computing (NC) emulates the neural structure and operation of the human brain at the physical level, and thus can efficiently perform multiple advanced computing tasks such as learning, recognition and cognition.

Memristors are promising candidates for NC thanks to the feasibility of high-density 3D integration and low energy consumption. Among them, the emerging optoelectronic memristors are competitive by virtue of combining the advantages of both photonics and electronics. However, the reversible tuning of memconductance depends highly on the electric excitation, which have severely limited the development and application of optoelectronic NC.

To address this issue, researchers at NIMTE proposed a bilayered oxide AOC memristor, based on the relatively mature semiconductor material InGaZnO and a memconductance tuning mechanism of light-induced electron trapping and detrapping.

The traditional electrical memristors require strong electrical stimuli to tune their memconductance, leading to high power consumption, a large amount of Joule heat, microstructural change triggered by the Joule heat, and even high crosstalk in memristor crossbars.

On the contrary, the developed AOC memristor does not involve microstructure changes, and can operate upon weak light irradiation with light power density of only 20 μW cm-2, which has provided a new approach to overcome the instability of the memristor.

Specifically, the AOC memristor can serve as an excellent synaptic emulator and thus mimic spike-timing-dependent plasticity (STDP) which is an important learning rule in the brain, indicating its potential applications in AOC spiking neural networks for high-efficiency optoelectronic NC.

Moreover, compared to purely optical computing, the optoelectronic computing using our AOC memristor showed higher practical feasibility, on account of the simple structure and fabrication process of the device.

The study may shed light on the in-depth research and practical application of optoelectronic NC, and thus promote the development of the new generation of AI.

This work was supported by the National Natural Science Foundation of China (No. 61674156 and 61874125), the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB32050204), and the Zhejiang Provincial Natural Science Foundation of China (No. LD19E020001).

Here’s a link to and a citation for the paper,

Hybrid oxide brain-inspired neuromorphic devices for hardware implementation of artificial intelligence by Jingrui Wang, Xia Zhuge & Fei Zhuge. Science and Technology of Advanced Materials Volume 22, 2021 – Issue 1 Pages 326-344 DOI: https://doi.org/10.1080/14686996.2021.1911277 Published online:14 May 2021

This paper appears to be open access.

Netherlands

In this case, a May 18, 2021 news item on Nanowerk marries oxides to spintronics,

Classic computers use binary values (0/1) to perform. By contrast, our brain cells can use more values to operate, making them more energy-efficient than computers. This is why scientists are interested in neuromorphic (brain-like) computing.

Physicists from the University of Groningen (the Netherlands) have used a complex oxide to create elements comparable to the neurons and synapses in the brain using spins, a magnetic property of electrons.

The press release, which follows, was accompanied by this image illustrating the work,

Caption: Schematic of the proposed device structure for neuromorphic spintronic memristors. The write path is between the terminals through the top layer (black dotted line), the read path goes through the device stack (red dotted line). The right side of the figure indicates how the choice of substrate dictates whether the device will show deterministic or probabilistic behaviour. Credit: Banerjee group, University of Groningen

A May 18, 2021 University of Groningen press release (also on EurekAlert), which originated the news item, adds more ‘spin’ to the story,

Although computers can do straightforward calculations much faster than humans, our brains outperform silicon machines in tasks like object recognition. Furthermore, our brain uses less energy than computers. Part of this can be explained by the way our brain operates: whereas a computer uses a binary system (with values 0 or 1), brain cells can provide more analogue signals with a range of values.

Thin films

The operation of our brains can be simulated in computers, but the basic architecture still relies on a binary system. That is why scientist look for ways to expand this, creating hardware that is more brain-like, but will also interface with normal computers. ‘One idea is to create magnetic bits that can have intermediate states’, says Tamalika Banerjee, Professor of Spintronics of Functional Materials at the Zernike Institute for Advanced Materials, University of Groningen. She works on spintronics, which uses a magnetic property of electrons called ‘spin’ to transport, manipulate and store information.

In this study, her PhD student Anouk Goossens, first author of the paper, created thin films of a ferromagnetic metal (strontium-ruthenate oxide, SRO) grown on a substrate of strontium titanate oxide. The resulting thin film contained magnetic domains that were perpendicular to the plane of the film. ‘These can be switched more efficiently than in-plane magnetic domains’, explains Goossens. By adapting the growth conditions, it is possible to control the crystal orientation in the SRO. Previously, out-of-plane magnetic domains have been made using other techniques, but these typically require complex layer structures.

Magnetic anisotropy

The magnetic domains can be switched using a current through a platinum electrode on top of the SRO. Goossens: ‘When the magnetic domains are oriented perfectly perpendicular to the film, this switching is deterministic: the entire domain will switch.’ However, when the magnetic domains are slightly tilted, the response is probabilistic: not all the domains are the same, and intermediate values occur when only part of the crystals in the domain have switched.

By choosing variants of the substrate on which the SRO is grown, the scientists can control its magnetic anisotropy. This allows them to produce two different spintronic devices. ‘This magnetic anisotropy is exactly what we wanted’, says Goossens. ‘Probabilistic switching compares to how neurons function, while the deterministic switching is more like a synapse.’

The scientists expect that in the future, brain-like computer hardware can be created by combining these different domains in a spintronic device that can be connected to standard silicon-based circuits. Furthermore, probabilistic switching would also allow for stochastic computing, a promising technology which represents continuous values by streams of random bits. Banerjee: ‘We have found a way to control intermediate states, not just for memory but also for computing.’

Here’s a link to and a citation for the paper,

Anisotropy and Current Control of Magnetization in SrRuO3/SrTiO3 Heterostructures for Spin-Memristors by A.S. Goossens, M.A.T. Leiviskä and T. Banerjee. Frontiers in Nanotechnology DOI: https://doi.org/10.3389/fnano.2021.680468 Published: 18 May 2021

This appears to be open access.

Follow up to the Charles M. Lieber affair and US government efforts to prosecute nanotech scientists

Rebecca Trager in a March 5, 2021 news article for Chemistry World highlights support for Charles M. Lieber (Harvard professor and chair of the chemistry department) from his colleagues (Note: Links have been removed),

More than a year after the chair of Harvard University’s chemistry department was arrested for allegedly hiding his receipt of millions of dollars in research funding from China from his university and the US government, dozens of prominent researchers – including many Nobel Prize winners – are coming to Charles Lieber’s defence. They are calling the US Department of Justice (DOJ) case against him ‘unjust’ and urging the agency to drop it.

Following his January 2020 arrest, Lieber was placed on ‘indefinite’ paid administrative leave. The nanoscience pioneer was indicted in June [2020] on charges of making false statements to federal authorities regarding his participation in China’s Thousand Talents plan – the country’s programme to attract, recruit and cultivate high-level scientific talent from abroad. Lieber faces up to five years in prison and a fine of $250,000 (£179,000) if convicted.

A 1 March [2021] open letter, drafted and coordinated by Harvard chemist Stuart Schreiber, co-founder of the Broad Institute, and professor emeritus Elias Corey, winner of the 1990 chemistry Nobel prize, says Lieber became the target of a ‘tragically misguided government campaign’. The letter refers to Lieber as ‘one of the great scientist of his generation’ and warns such government actions are discouraging US scientists from collaborating with peers in other countries, particularly China. The open letter also notes that Lieber is fighting to salvage his reputation while suffering from incurable lymphoma.

Ferguson goes on to contrast Lieber’s treatment by Harvard to another embattled colleague’s treatment by his home institution (Note: Links have been removed),

Harvard’s treatment of Lieber stands in contrast to how the Massachusetts Institute of Technology (MIT) handled the more recent case of nanotechnologist Gang Chen, who was arrested in January [2021] for failing to report his ties to the Chinese government. MIT agreed to cover his legal fees, and more than 100 faculty members signed a letter to their university’s president that picked apart the DOJ’s allegations against Chen.

I have more details about the case against Lieber (as it was presented at the time) in a January 28, 2020 posting.

As for Professor Chen, I found this MIT statement dated January 14, 2021 (the date of his arrest) and this January 14, 2021 statement from The United States District Attorney’s Office District of Massachusetts.

Carbon nanotubes (CNTs) in 466 colours

Caption: A color map illustrates the inherent colors of 466 types of carbon nanotubes with unique (n,m) designations based their chiral angle and diameter. Credit: Image courtesy of Kauppinen Group/Aalto University

This is, so to speak, a new angle on carbon nanotubes (CNTs). It’s also the first time I’ve seen two universities place identical news releases on EurekAlert under their individual names.

From the Dec. 14, 2020 Rice University (US) news release or the Dec. 14, 2020 Aalto University (Finland) press release on EurekAlert,

Nanomaterials researchers in Finland, the United States and China have created a color atlas for 466 unique varieties of single-walled carbon nanotubes.

The nanotube color atlas is detailed in a study in Advanced Materials about a new method to predict the specific colors of thin films made by combining any of the 466 varieties. The research was conducted by researchers from Aalto University in Finland, Rice University and Peking University in China.

“Carbon, which we see as black, can appear transparent or take on any color of the rainbow,” said Aalto physicist Esko Kauppinen, the corresponding author of the study. “The sheet appears black if light is completely absorbed by carbon nanotubes in the sheet. If less than about half of the light is absorbed in the nanotubes, the sheet looks transparent. When the atomic structure of the nanotubes causes only certain colors of light, or wavelengths, to be absorbed, the wavelengths that are not absorbed are reflected as visible colors.”

Carbon nanotubes are long, hollow carbon molecules, similar in shape to a garden hose but with sides just one atom thick and diameters about 50,000 times smaller than a human hair. The outer walls of nanotubes are made of rolled graphene. And the wrapping angle of the graphene can vary, much like the angle of a roll of holiday gift wrap paper. If the gift wrap is rolled carefully, at zero angle, the ends of the paper will align with each side of the gift wrap tube. If the paper is wound carelessly, at an angle, the paper will overhang on one end of the tube.

The atomic structure and electronic behavior of each carbon nanotube is dictated by its wrapping angle, or chirality, and its diameter. The two traits are represented in a “(n,m)” numbering system that catalogs 466 varieties of nanotubes, each with a characteristic combination of chirality and diameter. Each (n,m) type of nanotube has a characteristic color.

Kauppinen’s research group has studied carbon nanotubes and nanotube thin films for years, and it previously succeeded in mastering the fabrication of colored nanotube thin films that appeared green, brown and silver-grey.

In the new study, Kauppinen’s team examined the relationship between the spectrum of absorbed light and the visual color of various thicknesses of dry nanotube films and developed a quantitative model that can unambiguously identify the coloration mechanism for nanotube films and predict the specific colors of films that combine tubes with different inherent colors and (n,m) designations.

Rice engineer and physicist Junichiro Kono, whose lab solved the mystery of colorful armchair nanotubes in 2012, provided films made solely of (6,5) nanotubes that were used to calibrate and verify the Aalto model. Researchers from Aalto and Peking universities used the model to calculate the absorption of the Rice film and its visual color. Experiments showed that the measured color of the film corresponded quite closely to the color forecast by the model.

The Aalto model shows that the thickness of a nanotube film, as well as the color of nanotubes it contains, affects the film’s absorption of light. Aalto’s atlas of 466 colors of nanotube films comes from combining different tubes. The research showed that the thinnest and most colorful tubes affect visible light more than those with larger diameters and faded colors.

“Esko’s group did an excellent job in theoretically explaining the colors, quantitatively, which really differentiates this work from previous studies on nanotube fluorescence and coloration,” Kono said.

Since 2013, Kono’s lab has pioneered a method for making highly ordered 2D nanotube films. Kono said he had hoped to supply Kauppinen’s team with highly ordered 2D crystalline films of nanotubes of a single chirality.

“That was the original idea, but unfortunately, we did not have appropriate single-chirality aligned films at that time,” Kono said. “In the future, our collaboration plans to extend this work to study polarization-dependent colors in highly ordered 2D crystalline films.”

The experimental method the Aalto researchers used to grow nanotubes for their films was the same as in their previous studies: Nanotubes grow from carbon monoxide gas and iron catalysts in a reactor that is heated to more than 850 degrees Celsius. The growth of nanotubes with different colors and (n,m) designations is regulated with the help of carbon dioxide that is added to the reactor.

“Since the previous study, we have pondered how we might explain the emergence of the colors of the nanotubes,” said Nan Wei, an assistant research professor at Peking University who previously worked as a postdoctoral researcher at Aalto. “Of the allotropes of carbon, graphite and charcoal are black, and pure diamonds are colorless to the human eye. However, now we noticed that single-walled carbon nanotubes can take on any color: for example, red, blue, green or brown.”

Kauppinen said colored thin films of nanotubes are pliable and ductile and could be useful in colored electronics structures and in solar cells.

“The color of a screen could be modified with the help of a tactile sensor in mobile phones, other touch screens or on top of window glass, for example,” he said.

Kauppinen said the research can also provide a foundation for new kinds of environmentally friendly dyes.

Here’s a link to and a citation for the paper,

Colors of Single‐Wall Carbon Nanotubes by Nan Wei, Ying Tian, Yongping Liao, Natsumi Komatsu, Weilu Gao, Alina Lyuleeva‐Husemann, Qiang Zhang, Aqeel Hussain, Er‐Xiong Ding, Fengrui Yao, Janne Halme. Kaihui Liu, Junichiro Kono, Hua Jiang, Esko I. Kauppinen. Advanced Materials DOI: https://doi.org/10.1002/adma.202006395 First published: 14 December 2020

Thi8s paper is open access.

City University of Hong Kong (CityU) and its anti-bacterial graphene face masks

This looks like interesting work and I think the integration of visual images and embedded video in the news release (on the university website) is particularly well done. I won’t be including all the graphical information here as my focus is the text.

A Sept. 10, 2020 City University of Hong Kong (CityU) press release (also on EurekAlert) announces a greener, more effective face mask,

Face masks have become an important tool in fighting against the COVID-19 pandemic. However, improper use or disposal of masks may lead to “secondary transmission”. A research team from City University of Hong Kong (CityU) has successfully produced graphene masks with an anti-bacterial efficiency of 80%, which can be enhanced to almost 100% with exposure to sunlight for around 10 minutes. Initial tests also showed very promising results in the deactivation of two species of coronaviruses. The graphene masks are easily produced at low cost, and can help to resolve the problems of sourcing raw materials and disposing of non-biodegradable masks.

The research is conducted by Dr Ye Ruquan, Assistant Professor from CityU’s Department of Chemistry, in collaboration with other researchers. The findings were published in the scientific journal ACS Nano, titled “Self-Reporting and Photothermally Enhanced Rapid Bacterial Killing on a Laser-Induced Graphene Mask“.

Commonly used surgical masks are not anti-bacterial. This may lead to the risk of secondary transmission of bacterial infection when people touch the contaminated surfaces of the used masks or discard them improperly. Moreover, the melt-blown fabrics used as a bacterial filter poses an impact on the environment as they are difficult to decompose. Therefore, scientists have been looking for alternative materials to make masks.

Converting other materials into graphene by laser

Dr Ye has been studying the use of laser-induced graphene [emphasis mine] in developing sustainable energy. When he was studying PhD degree at Rice University several years ago, the research team he participated in and led by his supervisor discovered an easy way to produce graphene. They found that direct writing on carbon-containing polyimide films (a polymeric plastic material with high thermal stability) using a commercial CO2 infrared laser system can generate 3D porous graphene. The laser changes the structure of the raw material and hence generates graphene. That’s why it is named laser-induced graphene.

Graphene is known for its anti-bacterial properties, so as early as last September, before the outbreak of COVID-19, producing outperforming masks with laser-induced graphene already came across Dr Ye’s mind. He then kick-started the study in collaboration with researchers from the Hong Kong University of Science and Technology (HKUST), Nankai University, and other organisations.

Excellent anti-bacterial efficiency

The research team tested their laser-induced graphene with E. coli, and it achieved high anti-bacterial efficiency of about 82%. In comparison, the anti-bacterial efficiency of activated carbon fibre and melt-blown fabrics, both commonly-used materials in masks, were only 2% and 9% respectively. Experiment results also showed that over 90% of the E. coli deposited on them remained alive even after 8 hours, while most of the E. coli deposited on the graphene surface were dead after 8 hours. Moreover, the laser-induced graphene showed a superior anti-bacterial capacity for aerosolised bacteria.

Dr Ye said that more research on the exact mechanism of graphene’s bacteria-killing property is needed. But he believed it might be related to the damage of bacterial cell membranes by graphene’s sharp edge. And the bacteria may be killed by dehydration induced by the hydrophobic (water-repelling) property of graphene.

Previous studies suggested that COVID-19 would lose its infectivity at high temperatures. So the team carried out experiments to test if the graphene’s photothermal effect (producing heat after absorbing light) can enhance the anti-bacterial effect. The results showed that the anti-bacterial efficiency of the graphene material could be improved to 99.998% within 10 minutes under sunlight, while activated carbon fibre and melt-blown fabrics only showed an efficiency of 67% and 85% respectively.

The team is currently working with laboratories in mainland China to test the graphene material with two species of human coronaviruses. Initial tests showed that it inactivated over 90% of the virus in five minutes and almost 100% in 10 minutes under sunlight. The team plans to conduct testings with the COVID-19 virus later.

Their next step is to further enhance the anti-virus efficiency and develop a reusable strategy for the mask. They hope to release it to the market shortly after designing an optimal structure for the mask and obtaining the certifications.

Dr Ye described the production of laser-induced graphene as a “green technique”. All carbon-containing materials, such as cellulose or paper, can be converted into graphene using this technique. And the conversion can be carried out under ambient conditions without using chemicals other than the raw materials, nor causing pollution. And the energy consumption is low.

“Laser-induced graphene masks are reusable. If biomaterials are used for producing graphene, it can help to resolve the problem of sourcing raw material for masks. And it can lessen the environmental impact caused by the non-biodegradable disposable masks,” he added.

Dr Ye pointed out that producing laser-induced graphene is easy. Within just one and a half minutes, an area of 100 cm² can be converted into graphene as the outer or inner layer of the mask. Depending on the raw materials for producing the graphene, the price of the laser-induced graphene mask is expected to be between that of surgical mask and N95 mask. He added that by adjusting laser power, the size of the pores of the graphene material can be modified so that the breathability would be similar to surgical masks.

A new way to check the condition of the mask

To facilitate users to check whether graphene masks are still in good condition after being used for a period of time, the team fabricated a hygroelectric generator. It is powered by electricity generated from the moisture in human breath. By measuring the change in the moisture-induced voltage when the user breathes through a graphene mask, it provides an indicator of the condition of the mask. Experiment results showed that the more the bacteria and atmospheric particles accumulated on the surface of the mask, the lower the voltage resulted. “The standard of how frequently a mask should be changed is better to be decided by the professionals. Yet, this method we used may serve as a reference,” suggested Dr Ye.

Laser-induced graphene (LIG), Rice University, and Dr. Ye were mentioned here in a May 9, 2018 titled: Do you want that coffee with some graphene on toast?

Back to the latest research, read the caption carefully,

Research shows that over 90% of the E. coli deposited on activated carbon fibre (fig c and d) and melt-blown fabrics (fig e and f) remained alive even after 8 hours. In contrast, most of the E. coli deposited on the graphene surface (fig a and b) were dead. (Photo source: DOI number: 10.1021/acsnano.0c05330)

Here’s a link to and a citation for the paper,

Self-Reporting and Photothermally Enhanced Rapid Bacterial Killing on a Laser-Induced Graphene Mask by Libei Huang, Siyu Xu, Zhaoyu Wang, Ke Xue, Jianjun Su, Yun Song, Sijie Chen, Chunlei Zhu, Ben Zhong Tang, and Ruquan Ye. ACS Nano 2020, 14, 9, 12045–12053 DOI: https://doi.org/10.1021/acsnano.0c05330 Publication Date:August 11, 2020 Copyright © 2020 American Chemical Society

This paper is behind a paywall.

July 2020 update on Dr. He Jiankui (the CRISPR twins) situation

This was going to be written for January 2020 but sometimes things happen (e.g., a two-part overview of science culture in Canada from 2010-19 morphed into five parts with an addendum and, then, a pandemic). By now (July 28, 2020), Dr. He’s sentencing to three years in jail announced by the Chinese government in January 2020 is old news.

Regardless, it seems a neat and tidy ending to an international scientific scandal concerned with germline-editing which resulted in at least one set of twins, Lulu and Nana. He claimed to have introduced a variant (“Delta 32” variation) of their CCR5 gene. This does occur naturally and scientists have noted that people with this mutation seem to be resistant to HIV and smallpox.

For those not familiar with the events surrounding the announcement, here’s a brief recap. News of the world’s first gene-edited twins’ birth was announced in November 2018 just days before an international meeting group of experts who had agreed on a moratorium in 2015 on exactly that kind of work. The scientist making the announcement about the twins was scheduled for at least one presentation at the meeting, which was to be held in Hong Kong. He did give his presentation but left the meeting shortly afterwards as shock was beginning to abate and fierce criticism was rising. My November 28, 2018 posting (First CRISPR gene-edited babies? Ethics and the science story) offers a timeline of sorts and my initial response.

I subsequently followed up with two mores posts as the story continued to develop. My May 17, 2019 posting (Genes, intelligence, Chinese CRISPR (clustered regularly interspaced short palindromic repeats) babies, and other children) featured news that Dr. He’s gene-editing may have resulted in the twins having improved cognitive skills. Then, more news broke. The title for my June 20, 2019 posting (Greater mortality for the CRISPR twins Lulu and Nana?) is self-explanatory.

I have roughly organized my sources for this posting into two narratives, which I’m contrasting with each other. First, there is one found in the mainstream media (English language), ‘The Popular Narrative’. Second, there is story where Dr. He is viewed more sympathetically and as part of a larger community where there isn’t nearly as much consensus over what should or shouldn’t be done as ‘the popular narrative’ insists.

The popular narrative: Dr. He was a rogue scientist

A December 30, 2019 article for Fast Company by Kristin Toussaint lays out the latest facts (Note: A link has been removed),

… Now, a court in China has sentenced He to three years in prison, according to Xinhua, China’s state-run press agency, for “illegal medical practices.”

The court in China’s southern city of Shenzhen says that He’s team, which included colleagues Zhang Renli and Qin Jinzhou from two medical institutes in Guangdong Province, falsified ethical approval documents and violated China’s “regulations and ethical principles” with their gene-editing work. Zhang was sentenced to two years in jail, and Qin to 18 months with a two-year reprieve, according to Xinhau.

Ian Sample’s December 31, 2020 article for the Guardian offers more detail (Note: Links have been removed),

The court in Shenzhen found He guilty of “illegal medical practices” and in addition to the prison sentence fined him 3m yuan (£327,360), according to the state news agency, Xinhua. Two others on He’s research team received lesser fines and sentences.

“The three accused did not have the proper certification to practise medicine, and in seeking fame and wealth, deliberately violated national regulations in scientific research and medical treatment,” the court said, according to Xinhua. “They’ve crossed the bottom line of ethics in scientific research and medical ethics.”

[…] the court found He had forged documents from an ethics review panel that were used to recruit couples for the research. The couples that enrolled had a man with HIV and a woman without and were offered IVF in return for taking part.

Zhang Renli, who worked with He, was sentenced to two years in prison and fined 1m yuan. Colleague Qin Jinzhou received an 18-month sentence, but with a two-year reprieve, and a 500,000 yuan fine.

He’s experiments, which were carried out on seven embryos in late 2018, sent shockwaves through the medical and scientific world. The work was swiftly condemned for deceiving vulnerable patients and using a risky, untested procedure with no medical justification. Earlier this month, MIT Technology Review released excerpts from an early manuscript of He’s work. It casts serious doubts on his claims to have made the children immune to HIV.

Even as the scientific community turned against He, the scientist defended his work and said he was proud of having created Lulu and Nana. A third child has since been born as a result of the experiments.

Robin Lovell-Badge at the Francis Crick Institute in London said it was “far too premature” for anyone to pursue genome editing on embryos that are intended to lead to pregnancies. “At this stage we do not know if the methods will ever be sufficiently safe and efficient, although the relevant science is progressing rapidly, and new methods can look promising. It is also important to have standards established, including detailed regulatory pathways, and appropriate means of governance.”

A December 30, 2019 article, by Carolyn Y. Johnson for the Washington Post, covers much the same ground although it does go on to suggest that there might be some blame to spread around (Note: Links have been removed),

The Chinese researcher who stunned and alarmed the international scientific community with the announcement that he had created the world’s first gene-edited babies has been sentenced to three years in prison by a court in China.

He Jiankui sparked a bioethical crisis last year when he claimed to have edited the DNA of human embryos, resulting in the birth of twins called Lulu and Nana as well as a possible third pregnancy. The gene editing, which was aimed at making the children immune to HIV, was excoriated by many scientists as a reckless experiment on human subjects that violated basic ethical principles.

The judicial proceedings were not public, and outside experts said it is hard to know what to make of the punishment without the release of the full investigative report or extensive knowledge of Chinese law and the conditions under which He will be incarcerated.

Jennifer Doudna, a biochemist at the University of California at Berkeley who co-invented CRISPR, the gene editing technology that He utilized, has been outspoken in condemning the experiments and has repeatedly said CRISPR is not ready to be used for reproductive purposes.

R. Alta Charo, a fellow at Stanford’s Center for Advanced Study in the Behavioral Sciences, was among a small group of experts who had dinner with He the night before he unveiled his controversial research in Hong Kong in November 2018.

“He Jiankui is an example of somebody who fundamentally didn’t understand, or didn’t want to recognize, what have become international norms around responsible research,” Charo said. “My impression is he allowed his personal ambition to completely cloud rational thinking and judgment.”

Scientists have been testing an array of powerful biotechnology tools to fix genetic diseases in adults. There is tremendous excitement about the possibility of fixing genes that cause serious disease, and the first U.S. patients were treated with CRISPR this year.

But scientists have long drawn a clear moral line between curing genetic diseases in adults and editing and implanting human embryos, which raises the specter of “designer babies.” Those changes and any unanticipated ones could be inherited by future generations — in essence altering the human species.

“The fact that the individual at the center of the story has been punished for his role in it should not distract us from examining what supporting roles were played by others, particularly in the international scientific community and also the environment that shaped and encouraged him to push the limits,” said Benjamin Hurlbut [emphasis mine], associate professor in the School of Life Sciences at Arizona State University.

Stanford University cleared its scientists, including He’s former postdoctoral adviser, Stephen Quake, finding that Quake and others did not participate in the research and had expressed “serious concerns to Dr. He about his work.” A Rice University spokesman said an investigation continues into bioengineering professor Michael Deem, He’s former academic adviser. Deem was listed as a co-author on a paper called “Birth of Twins After Genome Editing for HIV Resistance,” submitted to scientific journals, according to MIT Technology Review.

It’s interesting that it’s only the Chinese scientists who are seen to be punished, symbolically at least. Meanwhile, Stanford clears its scientists of any wrongdoing and Rice University continues to investigate.

Watch for the Hurlbut name (son, Benjamin and father, William) to come up again in the ‘complex narrative’ section.

Criticism of the ‘twins’ CRISPR editing’ research

Antonio Regalado’s December 3, 2020 article for the MIT (Massachusetts Institute of Technology) Technology Review features comments from various experts on an unpublished draft of Dr. He Jiankui’s research

Earlier this year a source sent us a copy of an unpublished manuscript describing the creation of the first gene-edited babies, born last year in China. Today, we are making excerpts of that manuscript public for the first time.

Titled “Birth of Twins After Genome Editing for HIV Resistance,” and 4,699 words long, the still unpublished paper was authored by He Jiankui, the Chinese biophysicist who created the edited twin girls. A second manuscript we also received discusses laboratory research on human and animal embryos.

The metadata in the files we were sent indicate that the two draft papers were edited by He in late November 2018 and appear to be what he initially submitted for publication. Other versions, including a combined manuscript, may also exist. After consideration by at least two prestigious journals, Nature and JAMA, his research remains unpublished.

The text of the twins paper is replete with expansive claims of a medical breakthrough that can “control the HIV epidemic.” It claims “success”—a word used more than once—in using a “novel therapy” to render the girls resistant to HIV. Yet surprisingly, it makes little attempt to prove that the twins really are resistant to the virus. And the text largely ignores data elsewhere in the paper suggesting that the editing went wrong.

We shared the unpublished manuscripts with four experts—a legal scholar, an IVF doctor, an embryologist, and a gene-editing specialist—and asked them for their reactions. Their views were damning. Among them: key claims that He and his team made are not supported by the data; the babies’ parents may have been under pressure to agree to join the experiment; the supposed medical benefits are dubious at best; and the researchers moved forward with creating living human beings before they fully understood the effects of the edits they had made.

1. Why aren’t the doctors among the paper’s authors?

The manuscript begins with a list of the authors—10 of them, mostly from He Jiankui’s lab at the Southern University of Science and Technology, but also including Hua Bai, director of an AIDS support network, who helped recruit couples, and Michael Deem, an American biophysicist whose role is under review by Rice University. (His attorney previously said Deem never agreed to submit the manuscript and sought to remove his name from it.)

It’s a small number of people for such a significant project, and one reason is that some names are missing—notably, the fertility doctors who treated the patients and the obstetrician who delivered the babies. Concealing them may be an attempt to obscure the identities of the patients. However, it also leaves unclear whether or not these doctors understood they were helping to create the first gene-edited babies.

To some, the question of whether the manuscript is trustworthy arises immediately.

Hank Greely, professor of law, Stanford University: We have no, or almost no, independent evidence for anything reported in this paper. Although I believe that the babies probably were DNA-edited and were born, there’s very little evidence for that. Given the circumstances of this case, I am not willing to grant He Jiankui the usual presumption of honesty. 

That last article by Regalado is the purest example I have of how fierce the criticism is and how almost all of it is focused on Dr. He and his Chinese colleagues.

A complex, measured narrative: multiple players in the game

The most sympathetic and, in many ways, the most comprehensive article is an August 1, 2019 piece by Jon Cohen for Science magazine (Note: Links have been removed),

On 10 June 2017, a sunny and hot Saturday in Shenzhen, China, two couples came to the Southern University of Science and Technology (SUSTech) to discuss whether they would participate in a medical experiment that no researcher had ever dared to conduct. The Chinese couples, who were having fertility problems, gathered around a conference table to meet with He Jiankui, a SUSTech biophysicist. Then 33, He (pronounced “HEH”) had a growing reputation in China as a scientist-entrepreneur but was little known outside the country. “We want to tell you some serious things that might be scary,” said He, who was trim from years of playing soccer and wore a gray collared shirt, his cuffs casually unbuttoned.

He simply meant the standard in vitro fertilization (IVF) procedures. But as the discussion progressed, He and his postdoc walked the couples through informed consent forms [emphasis mine] that described what many ethicists and scientists view as a far more frightening proposition. Seventeen months later, the experiment triggered an international controversy, and the worldwide scientific community rejected him. The scandal cost him his university position and the leadership of a biotech company he founded. Commentaries labeled He, who also goes by the nickname JK, a “rogue,” “China’s Frankenstein,” and “stupendously immoral.” [emphases mine]

But that day in the conference room, He’s reputation remained untarnished. As the couples listened and flipped through the forms, occasionally asking questions, two witnesses—one American, the other Chinese—observed [emphasis mine]. Another lab member shot video, which Science has seen [emphasis mine], of part of the 50-minute meeting. He had recruited those couples because the husbands were living with HIV infections kept under control by antiviral drugs. The IVF procedure would use a reliable process called sperm washing to remove the virus before insemination, so father-to-child transmission was not a concern. Rather, He sought couples who had endured HIV-related stigma and discrimination and wanted to spare their children that fate by dramatically reducing their risk of ever becoming infected. [emphasis mine]

He, who for much of his brief career had specialized in sequencing DNA, offered a potential solution: CRISPR, the genome-editing tool that was revolutionizing biology, could alter a gene in IVF embryos to cripple production of an immune cell surface protein, CCR5, that HIV uses to establish an infection. “This technique may be able to produce an IVF baby naturally immunized against AIDS,” one consent form read.[emphasis mine]

The couples’ children could also pass the protective mutation to future generations. The prospect of this irrevocable genetic change is why, since the advent of CRISPR as a genome editor 5 years earlier, the editing of human embryos, eggs, or sperm has been hotly debated. The core issue is whether such germline editing would cross an ethical red line because it could ultimately alter our species. Regulations, some with squishy language, arguably prohibited it in many countries, China included.

Yet opposition was not unanimous. A few months before He met the couples, a committee convened by the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) concluded in a well-publicized report that human trials of germline editing “might be permitted” if strict criteria were met. The group of scientists, lawyers, bioethicists, and patient advocates spelled out a regulatory framework but cautioned that “these criteria are necessarily vague” because various societies, caregivers, and patients would view them differently. The committee notably did not call for an international ban, arguing instead for governmental regulation as each country deemed appropriate and “voluntary self-regulation pursuant to professional guidelines.”

[…] He hid his plans and deceived his colleagues and superiors, as many people have asserted? A preliminary investigation in China stated that He had forged documents, “dodged supervision,” and misrepresented blood tests—even though no proof of those charges was released [emphasis mine], no outsiders were part of the inquiry, and He has not publicly admitted to any wrongdoing. (CRISPR scientists in China say the He fallout has affected their research.) Many scientists outside China also portrayed He as a rogue actor. “I think there has been a failure of self-regulation by the scientific community because of a lack of transparency,” virologist David Baltimore, a Nobel Prize–winning researcher at the California Institute of Technology (Caltech) in Pasadena and co-chair of the Hong Kong summit, thundered at He after the biophysicist’s only public talk on the experiment.

Because the Chinese government has revealed little and He is not talking, key questions about his actions are hard to answer. Many of his colleagues and confidants also ignored Science‘s requests for interviews. But Ryan Ferrell, a public relations specialist He hired, has cataloged five dozen people who were not part of the study but knew or suspected what He was doing before it became public. Ferrell calls it He’s circle of trust. [emphasis mine]

That circle included leading scientists—among them a Nobel laureate—in China and the United States, business executives, an entrepreneur connected to venture capitalists, authors of the NASEM report, a controversial U.S. IVF specialist [John Zhang] who discussed opening a gene-editing clinic with He [emphasis mine], and at least one Chinese politician. “He had an awful lot of company to be called a ‘rogue,’” says geneticist George Church [emphases mine], a CRISPR pioneer at Harvard University who was not in the circle of trust and is one of the few scientists to defend at least some aspects of He’s experiment.

Some people sharply criticized He when he brought them into the circle; others appear to have welcomed his plans or did nothing. Several went out of their way to distance themselves from He after the furor erupted. For example, the two onlookers in that informed consent meeting were Michael Deem, He’s Ph.D. adviser at Rice University in Houston, Texas, and Yu Jun, a member of the Chinese Academy of Sciences (CAS) and co-founder of the Beijing Genomics Institute, the famed DNA sequencing company in Shenzhen. Deem remains under investigation by Rice for his role in the experiment and would not speak with Science. In a carefully worded statement, Deem’s lawyers later said he “did not meet the parents of the reported CCR5-edited children, or anyone else whose embryos were edited.” But earlier, Deem cooperated with the Associated Press (AP) for its exclusive story revealing the birth of the babies, which reported that Deem was “present in China when potential participants gave their consent and that he ‘absolutely’ thinks they were able to understand the risks. [emphasis mine]”

Yu, who works at CAS’s Beijing Institute of Genomics, acknowledges attending the informed consent meeting with Deem, but he told Science he did not know that He planned to implant gene-edited embryos. “Deem and I were chatting about something else,” says Yu, who has sequenced the genomes of humans, rice, silkworms, and date palms. “What was happening in the room was not my business, and that’s my personality: If it’s not my business, I pay very little attention.”

Some people who know He and have spoken to Science contend it is time for a more open discussion of how the biophysicist formed his circle of confidants and how the larger circle of trust—the one between the scientific community and the public—broke down. Bioethicist William Hurlbut at Stanford University [emphasis mine] in Palo Alto, California, who knew He wanted to conduct the embryo-editing experiment and tried to dissuade him, says that He was “thrown under the bus” by many people who once supported him. “Everyone ran for the exits, in both the U.S. and China. I think everybody would do better if they would just openly admit what they knew and what they did, and then collectively say, ‘Well, people weren’t clear what to do. We should all admit this is an unfamiliar terrain.’”

Steve Lombardi, a former CEO of Helicos, reacted far more charitably. Lombardi, who runs a consulting business in Bridgewater, Connecticut, says Quake introduced him to He to help find investors for Direct Genomics. “He’s your classic, incredibly bright, naïve entrepreneur—I run into them all the time,” Lombardi says. “He had the right instincts for what to do in China and just didn’t know how to do it. So I put him in front of as many people as I could.” Lombardi says He told him about his embryo-editing ambitions in August 2017, asking whether Lombardi could find investors for a new company that focused on “genetic medical tourism” and was based in China or, because of a potentially friendlier regulatory climate, Thailand. “I kept saying to him, ‘You know, you’ve got to deal with the ethics of this and be really sure that you know what you’re doing.’”

In April 2018, He asked Ferrell to handle his media full time. Ferrell was a good fit—he had an undergraduate degree in neuroscience, had spent a year in Beijing studying Chinese, and had helped another company using a pre-CRISPR genome editor. Now that a woman in the trial was pregnant, Ferrell says, He’s “understanding of the gravity of what he had done increased.” Ferrell had misgivings about the experiment, but he quit HDMZ and that August moved to Shenzhen. With the pregnancy already underway, Ferrell reasoned, “It was going to be the biggest science story of that week or longer, no matter what I did.”

MIT Technology Review had broken a story early that morning China time, saying human embryos were being edited and implanted, after reporter Antonio Regalado discovered descriptions of the project that He had posted online, without Ferrell’s knowledge, in an official Chinese clinical trial registry. Now, He gave AP the green light to post a detailed account, which revealed that twin girls—whom He, to protect their identifies, named Lulu and Nana—had been born. Ferrell and He also posted five unfinished YouTube videos explaining and justifying the unprecedented experiment.

“He was fearful that he’d be unable to communicate to the press and the onslaught in a way that would be in any way manageable for him,” Ferrell says. One video tried to forestall eugenics accusations, with He rejecting goals such as enhancing intelligence, changing skin color, and increasing sports performance as “not love.” Still, the group knew it had lost control of the news. [emphasis mine]

… On 7 March 2017, 5 weeks after the California gathering, He submitted a medical ethics approval application to the Shenzhen HarMoniCare Women and Children’s Hospital that outlined the planned CCR5 edit of human embryos. The babies, it claimed, would be resistant to HIV as well as to smallpox and cholera. (The natural CCR5 mutation may have been selected for because it helps carriers survive smallpox and plague, some studies suggest—but they don’t mention cholera.) “This is going to be a great science and medicine achievement ever since the IVF technology which was awarded the Nobel Prize in 2010, and will also bring hope to numerous genetic disease patients,” the application says. Seven people on the ethics committee, chaired by Lin Zhitong—a one-time Direct Genomics director and a HarMoniCare administrator—signed the application, indicating they approved it.

[…] John Zhang, […] [emphasis mine] earned his medical degree in China and a Ph.D. in reproductive biology at the University of Cambridge in the United Kingdom. Zhang had made international headlines himself in September 2016, when New Scientist revealed that he had created the world’s first “three-parent baby” by using mitochondrial DNA from a donor egg to revitalize the egg of a woman with infertility and then inseminating the resulting egg. “This technology holds great hope for ladies with advanced maternal age to have their own children with their own eggs,” Zhang explains in the center’s promotional video, which alternates between Chinese and English. It does not mention that Zhang did the IVF experiment in Mexico because it is not now allowed in the United States. [emphasis mine]

When Science contacted Zhang, the physician initially said he barely knew He: [emphases mine] “I know him just like many people know him, in an academic meeting.”

After his talk [November 2018 at Hong Kong meeting], He immediately drove back to Shenzhen, and his circle of trust began to disintegrate. He has not spoken publicly since. “I don’t think he can recover himself through PR,” says Ferrell, who no longer works for He but recently started to do part-time work for He’s wife. “He has to do other service to the world.”

Calls for a moratorium on human germline editing have increased, although at the end of the Hong Kong summit, the organizing committee declined in its consensus to call for a ban. China has stiffened its regulations on work with human embryos, and Chinese bioethicists in a Nature editorial about the incident urged the country to confront “the eugenic thinking that has persisted among a small proportion of Chinese scholars.”

Church, who has many CRISPR collaborations in China, finds it inconceivable that He’s work surprised the Chinese government. China has “the best surveillance system in the world,” he says. “I conclude that they were totally aware of what he was doing at every step of the way, especially because he wasn’t particularly secretive about it.”

Benjamin Hurlbut, William’s son and a historian of biomedicine at Arizona State University in Tempe, says leaders in the scientific community should take a hard look at their actions, too. [emphases mine] He thinks the 2017 NASEM report helped give rise to He by following a well-established approach to guiding science: appointing an elite group to decide how scientists should be regulated. Benjamin Hurlbut, whose book Experiments in Democracy explores the governance of embryo research and bioethics, questions why small, scientist-led groups—à la the totemic Asilomar conference held in 1975 to discuss the future of recombinant DNA research—are seen as the best way to shape thinking about new technologies. Hurlbut has called for a “global observatory for gene editing” to convene meetings with diverse perspectives.

The prevailing notion that the scientific community simply “failed to see the rogue among the responsible,” Hurlbut says, is a convenient narrative for those scientific leaders and inhibits their ability to learn from such failures. [emphases mine] “It puts them on the right side of history,” he says. They failed to paint a bright enough red line, Hurlbut contends. “They are not on the right side of history because they contributed to this.”

If you have the time, I strongly recommend reading Cohen’s piece in its entirety. You’ll find links to the reports and more articles with in-depth reporting on this topic.

A little kindness and no regrets

William Hurlbut was interviewed in an As it happens (Canadian Broadcasting Corporation’ CBC) radio programme segment on December 30, 2020. This is an excerpt from the story transcript written by Sheena Goodyear (Note: A link has been removed),

Dr. William Hurlbut, a physician and professor of neural-biology at Stanford University, says he tried to warn He to slow down before it was too late. Here is part of his conversation with As It Happens guest host Helen Mann.

What was your reaction to the news that Dr. He had been sentenced to three years in prison?

My first reaction was one of sadness because I know Dr. He — who we call J.K., that’s his nickname.

I spent quite a few hours talking with him, and I’m just sad that this worked out this way. It didn’t work out well for him or for his country or for the world, in some sense.

Except the one good thing is it’s alerted us, it’s awakened the world, to the seriousness of the issues that are coming down toward us with biotechnology, especially in genetics.

How does he feel about [how] not just the Chinese government, but the world generally, responded to his experiment?

He was surprised, personally. But I had actually warned him that he was proceeding too fast, and I didn’t know he had implanted embryos.

We had several conversations before this was disclosed, and I warned him to go more slowly and to keep in conversation with the rest of the international scientific community, and more broadly the international perspectives on social and ethical matters.

He was doing that to some extent, but not deeply enough and not transparently enough.

It sounds like you were very thoughtful in the conversations you had with him and the advice you gave him. And I guess you operated with what you had. But do you have any regrets yourself?

I don’t have any regrets about the way I conducted myself. I regret that this happened this way for J.K., who is a very bright person, and a very nice person, a humble person.

He grew up in a poor urban farming village. He told me that at one point he wanted to ask out a certain girl that he thought was really pretty … but he was embarrassed to do so because her family owned the restaurant. And so you see how humble his origins were.

By the way, he did end up asking her out and he ended up marrying her, which is a happy story, except now they’re separated for years of crucial time, and they have little children. 

I know this is a bigger story than just J.K. and his family. But there’s a personal story to it too.

What happens He Jiankui? … Is his research career over?

It’s hard to imagine that a nation like China would not give him some some useful role in their society. A very intelligent and very well-educated young man. 

But on the other hand, he will be forever a sign of a very crucial and difficult moment for the human species. He’s not going outlive that.

It’s going to be interesting. I hope I get a chance to have good conversations with him again and hear his internal ruminations and perspectives on it all.

This (“I don’t have any regrets about the way I conducted myself”) is where Hurlbut lost me. I think he could have suggested that he’d reviewed and rethought everything and feels that he and others could have done better and maybe they need to rethink how scientists are trained and how we talk about science, genetics, and emerging technology. Interestingly, it’s his son who comes up with something closer to what I’m suggesting (this excerpt was quoted earlier in this posting from a December 30, 2019 article, by Carolyn Y. Johnson for the Washington Post),

“The fact that the individual at the center of the story has been punished for his role in it should not distract us from examining what supporting roles were played by others, particularly in the international scientific community and also the environment that shaped and encouraged him to push the limits,” said Benjamin Hurlbut [emphasis mine], associate professor in the School of Life Sciences at Arizona State University.

The man who CRISPRs himself approves

Josiah Zayner publicly injected himself with CRISPR in a demonstration (see my January 25, 2018 posting for details about Zayner, his demonstration, and his plans). As you might expect, his take on the He affair is quite individual. From a January 2, 2020 article for STAT, Zayner presents the case for Dr. He’s work (Note: Links have been removed),

When I saw the news that He Jiankui and colleagues had been sentenced to three years in prison for the first human embryo gene editing and implantation experiments, all I could think was, “How will we look back at what they had done in 100 years?”

When the scientist described his research and revealed the births of gene edited twin girls at the [Second] International Summit on Human Genome Editing in Hong Kong in late November 2018, I stayed up into the early hours of the morning in Oakland, Calif., watching it. Afterward, I couldn’t sleep for a few days and couldn’t stop thinking about his achievement.

This was the first time a viable human embryo was edited and allowed to live past 14 days, much less the first time such an embryo was implanted and the baby brought to term.

The majority of scientists were outraged at the ethics of what had taken place, despite having very little information on what had actually occurred.

To me, no matter how abhorrent one views [sic] the research, it represents a substantial step forward in human embryo editing. Now there is a clear path forward that anyone can follow when before it had been only a dream.

As long as the children He Jiankui engineered haven’t been harmed by the experiment, he is just a scientist who forged some documents to convince medical doctors to implant gene-edited embryos. The 4-minute mile of human genetic engineering has been broken. It will happen again.

The academic establishment and federal funding regulations have made it easy to control the number of heretical scientists. We rarely if ever hear of individuals pushing the ethical and legal boundaries of science.

The rise of the biohacker is changing that.

A biohacker is a scientist who exists outside academia or an institution. By this definition, He Jiankui is a biohacker. I’m also part of this community, and helped build an organization to support it.

Such individuals have much more freedom than “traditional” scientists because scientific regulation in the U.S. is very much institutionally enforced by the universities, research organizations, or grant-giving agencies. But if you are your own institution and don’t require federal grants, who can police you? If you don’t tell anyone what you are doing, there is no way to stop you — especially since there is no government agency actively trying to stop people from editing embryos.

… When a human embryo being edited and implanted is no longer interesting enough for a news story, will we still view He Jiankui as a villain?

I don’t think we will. But even if we do, He Jiankui will be remembered and talked about more than any scientist of our day. Although that may seriously aggravate many scientists and bioethicists, I think he deserves that honor.

Josiah Zayner is CEO of The ODIN, a company that teaches people how to do genetic engineering in their homes.

You can find The ODIN here.

Final comments

There can’t be any question that this was inevitable. One needs only to take a brief stroll through the history of science to know that scientists are going to push boundaries or, as in this case, press past an ill-defined grey zone.

The only scientists who are being publicly punished for hubris are Dr. He Jiankui and his two colleagues in China. Dr. Michael Deem is still working for Rice University as far as I can determine. Here’s how the Wikipedia entry for the He Jiankui Affair describes the investigation (Note: Links have been removed),

Michael W. Deem, an American bioengineering professor at Rice University and He’s doctoral advisor, was involved in the research, and was present when people involved in He’s study gave consent.[24] He was the only non-Chinese out of 10 authors listed in the manuscript submitted to Nature.[30] Deem came under investigation by Rice University after news of the work was made public.[58] As of 31 December 2019, the university had not released a decision.[59] [emphasis mine]

Meanwhile the scientists at Stanford are cleared. While there are comments about the Chinese government not being transparent, it seems to me that US universities are just as opaque.

What seems missing from all this discussion and opprobrium is that the CRISPR technology itself is problematic. My September 20, 2019 post features research into off-target results from CRISPR gene-editing and, prior, there was this July 17, 2018 posting (The CRISPR [clustered regularly interspaced short palindromic repeats]-CAS9 gene-editing technique may cause new genetic damage kerfuffle).

I’d like to see more discussion and, in line with Benjamin Hurlbut’s thinking, I’d like to see more than a small group of experts talking to each other as part of the process especially here in Canada and in light of efforts to remove our ban on germline-editing (see my April 26, 2019 posting for more about those efforts).

Antiviral, antibacterial surface for reducing spread of infectious diseases

In the past several years, scientists have created antibacterial surfaces by fabricating materials with specific types of nanostructures. According to a May 27, 2020 news item on Nanowerk, scientists have now been able to add antiviral properties (Note: A link has been removed),

The novel coronavirus pandemic has caused an increased demand for antimicrobial treatments that can keep surfaces clean, particularly in health care settings. Although some surfaces have been developed that can combat bacteria, what’s been lacking is a surface that can also kill off viruses.

Now, researchers have found a way to impart durable antiviral and antibacterial properties to an aluminum alloy used in hospitals, according to a report in ACS Biomaterials Science & Engineering (“Antiviral and Antibacterial Nanostructured Surfaces with Excellent Mechanical Properties for Hospital Applications”).

A May 27, 2020 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, describes the problem and the proposed solution,

Among other mechanisms, viruses and bacteria can spread when a person touches a site where germs have settled, such as a doorframe, handrail or medical device. A healthy person can often fight off these bugs, but hospital patients can be more vulnerable to infection. The number of hospital-acquired infections has been on the decline in the U.S., but they still cause tens of thousands of deaths every year, according to the U.S. Department of Health and Human Services. Chemical disinfectants or coatings containing hydrophobic compounds, silver ions or copper can reduce infectious contaminants on surfaces, but these treatments don’t last. However, nature has developed its own solutions for battling microorganisms, including microscopic structural features that render some insect wings lethal to bacteria. Scientists have replicated this effect by forming surfaces covered with minute pillars and other shapes that distort and kill bacterial cells. But Prasad Yarlagadda and colleagues wanted to inactivate viruses as well as bacteria, so they set out to generate a novel nanoscale topography on long-lasting, industrially relevant materials.

The team experimented with disks of aluminum 6063, which is used in doorframes, window panels, and hospital and medical equipment. Etching the disks with sodium hydroxide for up to 3 hours changed the initially smooth, hydrophobic surface into a ridged, hydrophilic surface. Bacteria or viruses were then applied to the etched disks. Most of the Pseudomonas aeruginosa and Staphylococcus aureus bacteria were inactivated after 3 hours on the surface, while viability of common respiratory viruses dropped within 2 hours; both results were better than with plastic or smooth aluminum surfaces. The disks retained their effectiveness even after tests designed to mimic hospital wear and tear. The researchers note this is the first report to show combined antibacterial and antiviral properties of a durable, nanostructured surface that has the potential to stop the spread of infections arising from physical surfaces in hospitals. This strategy could be extended to surfaces in other public areas, such as cruise ships, planes and airports, they say. The team is now studying the effects of their nano-textured aluminum surfaces on the novel coronavirus.

This approach reminds me of Sharklet, a company fabricating a material designed to mimic a shark’s skin which is naturally antibacterial due to the nanostructures on its skin (see my September 18, 2014 posting).

More about Sharklet later. First, here’s a link to and a citation for the paper about this latest work,

Antiviral and Antibacterial Nanostructured Surfaces with Excellent Mechanical Properties for Hospital Applications by Jafar Hasan, Yanan Xu, Tejasri Yarlagadda, Michael Schuetz, Kirsten Spann, and Prasad KDV Yarlagadda. ACS Biomater. Sci. Eng. 2020, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsbiomaterials.0c00348 Publication Date:May 7, 2020 Copyright © 2020 American Chemical Society

This paper is behind a paywall.

Business and science: a Sharklet update

You can find the Sharklet website here. I wasn’t able to find any news about recent business deals other than the company’s acquisition by Peaceful Union in May 2017. From a May 17, 2017 Sharklet news release on Business Wire (and on the company website here),

Sharklet Technologies, Inc., a biotechnology company lauded for the creation and commercialization of Sharklet®, the world’s first micro-texture that inhibits bacterial growth on surfaces, has announced that it has completed a financing event led by Peaceful Union, an equity medical device firm in Hangzhou, China. Terms of the transaction were not disclosed.

The acquisition of the company will enable Sharklet Technologies to accelerate the development of Sharklet for medical devices where chemical-free bacterial inhibition is desired as well as high-touch surfaces prone to bacterial contamination. The company also will accelerate development of a newly enhanced wound dressing technology to encourage healing.

Joe Bagan and Mark Spiecker led the transaction structure. “This is an important day for the company and investors,” said Joe Bagan, former board chair, and Mark Spiecker, former CEO. “Our investors will realize a significant transaction while enabling the company to accelerate growth.”

In concert with the investment, Sharklet Technologies founding member, chief technology officer, and Sharklet inventor Dr. Anthony Brennan, will become chairman of the board assuming duties from chairman Joe Bagan and CEO Mark Spiecker.

Interestingly, Bagan and Spiecker are Chief Executive Officer (CEO) and President, respectively at STAQ Pharma. I wonder if there are plans to sell this company too.

Getting back to Sharklet, I found two items of recent origin about business but I cannot speak to the accuracy or trustworthiness of either item. That said, you will find they provide some detail about Sharklet’s new business directions and new business ties.

While Sharklet’s current business associations have a sketchy quality, it seems that’s not unusual in business, especially where new technologies are concerned. For example, the introduction of electricity into homes and businesses was a tumultuous affair as the 2008 book, ‘Power Struggles; Scientific Authority and the Creation of Practical Electricity Before Edison’ by Michael Brian Schiffer makes clear, from the MIT [Massachusetts Institute of Technology] Press ‘Power Struggles’ webpage,

In 1882, Thomas Edison and his Edison Electric Light Company unveiled the first large-scale electrical system in the world to light a stretch of offices in a city. … After laying out a unified theoretical framework for understanding technological change, Schiffer presents a series of fascinating case studies of pre-Edison electrical technologies, including Volta’s electrochemical battery, the blacksmith’s electric motor, the first mechanical generators, Morse’s telegraph, the Atlantic cable, and the lighting of the Capitol dome. Schiffer discusses claims of “practicality” and “impracticality” (sometimes hotly contested) made for these technologies, and examines the central role of the scientific authority—in particular, the activities of Joseph Henry, mid-nineteenth-century America’s foremost scientist—in determining the fate of particular technologies. These emerging electrical technologies formed the foundation of the modern industrial world. Schiffer shows how and why they became commercial products in the context of an evolving corporate capitalism in which conflicting judgments of practicality sometimes turned into power struggles. [emphases mine]

Even given that the book’s focus is pre-Edison electricity, how do you mention Edison himself without even casually mentioning Nikola Tesla and George Westinghouse in the book’s overview? Getting back to my point, emerging technologies do not emerge easily.

China’s neuromorphic chips: Darwin and Tianjic

I believe that China has more than two neuromorphic chips. The two being featured here are the ones for which I was easily able to find information.

The Darwin chip

The first information (that I stumbled across) about China and a neuromorphic chip (Darwin) was in a December 22, 2015 Science China Press news release on EurekAlert,

Artificial Neural Network (ANN) is a type of information processing system based on mimicking the principles of biological brains, and has been broadly applied in application domains such as pattern recognition, automatic control, signal processing, decision support system and artificial intelligence. Spiking Neural Network (SNN) is a type of biologically-inspired ANN that perform information processing based on discrete-time spikes. It is more biologically realistic than classic ANNs, and can potentially achieve much better performance-power ratio. Recently, researchers from Zhejiang University and Hangzhou Dianzi University in Hangzhou, China successfully developed the Darwin Neural Processing Unit (NPU), a neuromorphic hardware co-processor based on Spiking Neural Networks, fabricated by standard CMOS technology.

With the rapid development of the Internet-of-Things and intelligent hardware systems, a variety of intelligent devices are pervasive in today’s society, providing many services and convenience to people’s lives, but they also raise challenges of running complex intelligent algorithms on small devices. Sponsored by the college of Computer science of Zhejiang University, the research group led by Dr. De Ma from Hangzhou Dianzi university and Dr. Xiaolei Zhu from Zhejiang university has developed a co-processor named as Darwin.The Darwin NPU aims to provide hardware acceleration of intelligent algorithms, with target application domain of resource-constrained, low-power small embeddeddevices. It has been fabricated by 180nm standard CMOS process, supporting a maximum of 2048 neurons, more than 4 million synapses and 15 different possible synaptic delays. It is highly configurable, supporting reconfiguration of SNN topology and many parameters of neurons and synapses.Figure 1 shows photos of the die and the prototype development board, which supports input/output in the form of neural spike trains via USB port.

The successful development ofDarwin demonstrates the feasibility of real-time execution of Spiking Neural Networks in resource-constrained embedded systems. It supports flexible configuration of a multitude of parameters of the neural network, hence it can be used to implement different functionalities as configured by the user. Its potential applications include intelligent hardware systems, robotics, brain-computer interfaces, and others.Since it uses spikes for information processing and transmission,similar to biological neural networks, it may be suitable for analysis and processing of biological spiking neural signals, and building brain-computer interface systems by interfacing with animal or human brains. As a prototype application in Brain-Computer Interfaces, Figure 2 [not included here] describes an application example ofrecognizingthe user’s motor imagery intention via real-time decoding of EEG signals, i.e., whether he is thinking of left or right, and using it to control the movement direction of a basketball in the virtual environment. Different from conventional EEG signal analysis algorithms, the input and output to Darwin are both neural spikes: the input is spike trains that encode EEG signals; after processing by the neural network, the output neuron with the highest firing rate is chosen as the classification result.

The most recent development for this chip was announced in a September 2, 2019 Zhejiang University press release (Note: Links have been removed),

The second generation of the Darwin Neural Processing Unit (Darwin NPU 2) as well as its corresponding toolchain and micro-operating system was released in Hangzhou recently. This research was led by Zhejiang University, with Hangzhou Dianzi University and Huawei Central Research Institute participating in the development and algorisms of the chip. The Darwin NPU 2 can be primarily applied to smart Internet of Things (IoT). It can support up to 150,000 neurons and has achieved the largest-scale neurons on a nationwide basis.

The Darwin NPU 2 is fabricated by standard 55nm CMOS technology. Every “neuromorphic” chip is made up of 576 kernels, each of which can support 256 neurons. It contains over 10 million synapses which can construct a powerful brain-inspired computing system.

“A brain-inspired chip can work like the neurons inside a human brain and it is remarkably unique in image recognition, visual and audio comprehension and naturalistic language processing,” said MA De, an associate professor at the College of Computer Science and Technology on the research team.

“In comparison with traditional chips, brain-inspired chips are more adept at processing ambiguous data, say, perception tasks. Another prominent advantage is their low energy consumption. In the process of information transmission, only those neurons that receive and process spikes will be activated while other neurons will stay dormant. In this case, energy consumption can be extremely low,” said Dr. ZHU Xiaolei at the School of Microelectronics.

To cater to the demands for voice business, Huawei Central Research Institute designed an efficient spiking neural network algorithm in accordance with the defining feature of the Darwin NPU 2 architecture, thereby increasing computing speeds and improving recognition accuracy tremendously.

Scientists have developed a host of applications, including gesture recognition, image recognition, voice recognition and decoding of electroencephalogram (EEG) signals, on the Darwin NPU 2 and reduced energy consumption by at least two orders of magnitude.

In comparison with the first generation of the Darwin NPU which was developed in 2015, the Darwin NPU 2 has escalated the number of neurons by two orders of magnitude from 2048 neurons and augmented the flexibility and plasticity of the chip configuration, thus expanding the potential for applications appreciably. The improvement in the brain-inspired chip will bring in its wake the revolution of computer technology and artificial intelligence. At present, the brain-inspired chip adopts a relatively simplified neuron model, but neurons in a real brain are far more sophisticated and many biological mechanisms have yet to be explored by neuroscientists and biologists. It is expected that in the not-too-distant future, a fascinating improvement on the Darwin NPU 2 will come over the horizon.

I haven’t been able to find a recent (i.e., post 2017) research paper featuring Darwin but there is another chip and research on that one was published in July 2019. First, the news.

The Tianjic chip

A July 31, 2019 article in the New York Times by Cade Metz describes the research and offers what seems to be a jaundiced perspective about the field of neuromorphic computing (Note: A link has been removed),

As corporate giants like Ford, G.M. and Waymo struggle to get their self-driving cars on the road, a team of researchers in China is rethinking autonomous transportation using a souped-up bicycle.

This bike can roll over a bump on its own, staying perfectly upright. When the man walking just behind it says “left,” it turns left, angling back in the direction it came.

It also has eyes: It can follow someone jogging several yards ahead, turning each time the person turns. And if it encounters an obstacle, it can swerve to the side, keeping its balance and continuing its pursuit.

… Chinese researchers who built the bike believe it demonstrates the future of computer hardware. It navigates the world with help from what is called a neuromorphic chip, modeled after the human brain.

Here’s a video, released by the researchers, demonstrating the chip’s abilities,

Now back to back to Metz’s July 31, 2019 article (Note: A link has been removed),

The short video did not show the limitations of the bicycle (which presumably tips over occasionally), and even the researchers who built the bike admitted in an email to The Times that the skills on display could be duplicated with existing computer hardware. But in handling all these skills with a neuromorphic processor, the project highlighted the wider effort to achieve new levels of artificial intelligence with novel kinds of chips.

This effort spans myriad start-up companies and academic labs, as well as big-name tech companies like Google, Intel and IBM. And as the Nature paper demonstrates, the movement is gaining significant momentum in China, a country with little experience designing its own computer processors, but which has invested heavily in the idea of an “A.I. chip.”

If you can get past what seems to be a patronizing attitude, there are some good explanations and cogent criticisms in the piece (Metz’s July 31, 2019 article, Note: Links have been removed),

… it faces significant limitations.

A neural network doesn’t really learn on the fly. Engineers train a neural network for a particular task before sending it out into the real world, and it can’t learn without enormous numbers of examples. OpenAI, a San Francisco artificial intelligence lab, recently built a system that could beat the world’s best players at a complex video game called Dota 2. But the system first spent months playing the game against itself, burning through millions of dollars in computing power.

Researchers aim to build systems that can learn skills in a manner similar to the way people do. And that could require new kinds of computer hardware. Dozens of companies and academic labs are now developing chips specifically for training and operating A.I. systems. The most ambitious projects are the neuromorphic processors, including the Tianjic chip under development at Tsinghua University in China.

Such chips are designed to imitate the network of neurons in the brain, not unlike a neural network but with even greater fidelity, at least in theory.

Neuromorphic chips typically include hundreds of thousands of faux neurons, and rather than just processing 1s and 0s, these neurons operate by trading tiny bursts of electrical signals, “firing” or “spiking” only when input signals reach critical thresholds, as biological neurons do.

Tiernan Ray’s August 3, 2019 article about the chip for ZDNet.com offers some thoughtful criticism with a side dish of snark (Note: Links have been removed),

Nature magazine’s cover story [July 31, 2019] is about a Chinese chip [Tianjic chip]that can run traditional deep learning code and also perform “neuromorophic” operations in the same circuitry. The work’s value seems obscured by a lot of hype about “artificial general intelligence” that has no real justification.

The term “artificial general intelligence,” or AGI, doesn’t actually refer to anything, at this point, it is merely a placeholder, a kind of Rorschach Test for people to fill the void with whatever notions they have of what it would mean for a machine to “think” like a person.

Despite that fact, or perhaps because of it, AGI is an ideal marketing term to attach to a lot of efforts in machine learning. Case in point, a research paper featured on the cover of this week’s Nature magazine about a new kind of computer chip developed by researchers at China’s Tsinghua University that could “accelerate the development of AGI,” they claim.

The chip is a strange hybrid of approaches, and is intriguing, but the work leaves unanswered many questions about how it’s made, and how it achieves what researchers claim of it. And some longtime chip observers doubt the impact will be as great as suggested.

“This paper is an example of the good work that China is doing in AI,” says Linley Gwennap, longtime chip-industry observer and principal analyst with chip analysis firm The Linley Group. “But this particular idea isn’t going to take over the world.”

The premise of the paper, “Towards artificial general intelligence with hybrid Tianjic chip architecture,” is that to achieve AGI, computer chips need to change. That’s an idea supported by fervent activity these days in the land of computer chips, with lots of new chip designs being proposed specifically for machine learning.

The Tsinghua authors specifically propose that the mainstream machine learning of today needs to be merged in the same chip with what’s called “neuromorphic computing.” Neuromorphic computing, first conceived by Caltech professor Carver Mead in the early ’80s, has been an obsession for firms including IBM for years, with little practical result.

[Missing details about the chip] … For example, the part is said to have “reconfigurable” circuits, but how the circuits are to be reconfigured is never specified. It could be so-called “field programmable gate array,” or FPGA, technology or something else. Code for the project is not provided by the authors as it often is for such research; the authors offer to provide the code “on reasonable request.”

More important is the fact the chip may have a hard time stacking up to a lot of competing chips out there, says analyst Gwennap. …

What the paper calls ANN and SNN are two very different means of solving similar problems, kind of like rotating (helicopter) and fixed wing (airplane) are for aviation,” says Gwennap. “Ultimately, I expect ANN [?] and SNN [spiking neural network] to serve different end applications, but I don’t see a need to combine them in a single chip; you just end up with a chip that is OK for two things but not great for anything.”

But you also end up generating a lot of buzz, and given the tension between the U.S. and China over all things tech, and especially A.I., the notion China is stealing a march on the U.S. in artificial general intelligence — whatever that may be — is a summer sizzler of a headline.

ANN could be either artificial neural network or something mentioned earlier in Ray’s article, a shortened version of CANN [continuous attractor neural network].

Shelly Fan’s August 7, 2019 article for the SingularityHub is almost as enthusiastic about the work as the podcasters for Nature magazine  were (a little more about that later),

The study shows that China is readily nipping at the heels of Google, Facebook, NVIDIA, and other tech behemoths investing in developing new AI chip designs—hell, with billions in government investment it may have already had a head start. A sweeping AI plan from 2017 looks to catch up with the US on AI technology and application by 2020. By 2030, China’s aiming to be the global leader—and a champion for building general AI that matches humans in intellectual competence.

The country’s ambition is reflected in the team’s parting words.

“Our study is expected to stimulate AGI [artificial general intelligence] development by paving the way to more generalized hardware platforms,” said the authors, led by Dr. Luping Shi at Tsinghua University.

Using nanoscale fabrication, the team arranged 156 FCores, containing roughly 40,000 neurons and 10 million synapses, onto a chip less than a fifth of an inch in length and width. Initial tests showcased the chip’s versatility, in that it can run both SNNs and deep learning algorithms such as the popular convolutional neural network (CNNs) often used in machine vision.

Compared to IBM TrueNorth, the density of Tianjic’s cores increased by 20 percent, speeding up performance ten times and increasing bandwidth at least 100-fold, the team said. When pitted against GPUs, the current hardware darling of machine learning, the chip increased processing throughput up to 100 times, while using just a sliver (1/10,000) of energy.

BTW, Fan is a neuroscientist (from her SingularityHub profile page),

Shelly Xuelai Fan is a neuroscientist-turned-science writer. She completed her PhD in neuroscience at the University of British Columbia, where she developed novel treatments for neurodegeneration. While studying biological brains, she became fascinated with AI and all things biotech. Following graduation, she moved to UCSF [University of California at San Francisco] to study blood-based factors that rejuvenate aged brains. She is the co-founder of Vantastic Media, a media venture that explores science stories through text and video, and runs the award-winning blog NeuroFantastic.com. Her first book, “Will AI Replace Us?” (Thames & Hudson) will be out April 2019.

Onto Nature. Here’s a link to and a citation for the paper,

Towards artificial general intelligence with hybrid Tianjic chip architecture by Jing Pei, Lei Deng, Sen Song, Mingguo Zhao, Youhui Zhang, Shuang Wu, Guanrui Wang, Zhe Zou, Zhenzhi Wu, Wei He, Feng Chen, Ning Deng, Si Wu, Yu Wang, Yujie Wu, Zheyu Yang, Cheng Ma, Guoqi Li, Wentao Han, Huanglong Li, Huaqiang Wu, Rong Zhao, Yuan Xie & Luping Shi. Nature volume 572, pages106–111(2019) DOI: https//doi.org/10.1038/s41586-019-1424-8 Published: 31 July 2019 Issue Date: 01 August 2019

This paper is behind a paywall.

The July 31, 2019 Nature podcast, which includes a segment about the Tianjic chip research from China, which is at the 9 mins. 13 secs. mark (AI hardware) or you can scroll down about 55% of the way to the transcript of the interview with Luke Fleet, the Nature editor who dealt with the paper.

Some thoughts

The pundits put me in mind of my own reaction when I heard about phones that could take pictures. I didn’t see the point but, as it turned out, there was a perfectly good reason for combining what had been two separate activities into one device. It was no longer just a telephone and I had completely missed the point.

This too may be the case with the Tianjic chip. I think it’s too early to say whether or not it represents a new type of chip or if it’s a dead end.

Gecko-like toes needed for climbing robots

Caption: The spotted belly of a Tokay gecko used by UC Berkeley biologists to understand how the animal’s five sticky toes help it climb on many types of surface. Credit: Yi Song

Those are fabulous toes. Geckos and the fine hairs on their toes have been of great interest to researchers looking to increase qualities of adhesion for all kinds of purposes including for robots that climb. The latest foray into the research suggests that it’s not just the fine hairs found on gecko toes that are important.

A May 8, 2020 news item on ScienceDaily makes the proclamation,

Robots with toes? Experiments suggest that climbing robots could benefit from having flexible, hairy toes, like those of geckos, that can adjust quickly to accommodate shifting weight and slippery surfaces.

Biologists from the University of California, Berkeley, and Nanjing University of Aeronautics and Astronautics observed geckos running horizontally along walls to learn how they use their five toes to compensate for different types of surfaces without slowing down.

Close-up look at the toe pads of a Tokay gecko. They have about 15,000 hairs per foot, each of which has split ends that maximize contact with the surface and support the animal’s weight by interacting with surface molecules via van der Waals forces. (Photo by Yi Song)

You can find that image and more embedded in the May 8, 2020 University of California at Berkeley news release (also on EurekAlert) by Robert Sanders. The news release delves further into the work

“The research helped answer a fundamental question: Why have many toes?” said Robert Full, UC Berkeley professor of integrative biology.

As his previous research showed, geckos’ toes can stick to the smoothest surfaces through the use of intermolecular forces, and uncurl and peel in milliseconds. Their toes have up to 15,000 hairs per foot, and each hair has “an awful case of split ends, with as many as a thousand nano-sized tips that allow close surface contact,” he said.

These discoveries have spawned research on new types of adhesives that use intermolecular forces, or van der Waals forces, to stick almost anywhere, even underwater.

One puzzle, he said, is that gecko toes only stick in one direction. They grab when pulled in one direction, but release when peeled in the opposite direction. Yet, geckos move agilely in any orientation.

To determine how geckos have learned to deal with shifting forces as they move on different surfaces, Yi Song, a UC Berkeley visiting student from Nanjing, China, ran geckos sideways along a vertical wall while making high-speed video recordings to show the orientation of their toes. The sideways movement allowed him to distinguish downward gravity from forward running forces to best test the idea of toe compensation.

Using a technique called frustrated total internal reflection, Song, also measured the area of contact of each toe. The technique made the toes light up when they touched a surface.

To the researcher’s surprise, geckos ran sideways just as fast as they climbed upward, easily and quickly realigning their toes against gravity. The toes of the front and hind top feet during sideways wall-running shifted upward and acted just like toes of the front feet during climbing.

To further explore the value of adjustable toes, researchers added slippery patches and strips, as well as irregular surfaces. To deal with these hazards, geckos took advantage of having multiple, soft toes. The redundancy allowed toes that still had contact with the surface to reorient and distribute the load, while the softness let them conform to rough surfaces.

“Toes allowed agile locomotion by distributing control among multiple, compliant, redundant structures that mitigate the risks of moving on challenging terrain,” Full said. “Distributed control shows how biological adhesion can be deployed more effectively and offers design ideas for new robot feet, novel grippers and unique manipulators.”

The team, which also includes Zhendong Dai and Zhouyi Wang of the College of Mechanical and Electrical Engineering at Nanjing University of Aeronautics and Astronautics, published its findings this week in the journal Proceedings of the Royal Society B.

Here’s a link to and a citation for the paper,

Role of multiple, adjustable toes in distributed control shown by sideways wall-running in geckos by Yi Song, Zhendong Dai, Zhouyi Wang, and Robert J. Full. Proceedings of the Royal Society B; Biological Sciences 29 April 2020 Volume 287Issue 1926 DOI: https://doi.org/10.1098/rspb.2020.0123 Published [online]:06 May 2020

This paper is open access.

Gas nanomedicine

This study comes from China and it offers an overview of the state-of-the-art of gas nanomedicine and a roadmap for future research. A May 6, 2020 news item on Nanowerk announces the study,

Cancer is deadly, but available cancer treatment methods are quite limited. The use of therapeutic gas molecules such as H2 [hydrogen gas], NO [nitrogen oxide], CO [carbon monoxide] and H2S [hydrogn sulfide] for cancer treatment is promising owing to their unique properties for selectively killing cancer cells and protecting normal cells from damage from other traditional therapies.

However, these gases and most of their prodrugs lack the abilities of active intratumoral accumulation and controlled gas release, causing limited therapeutic efficacy and potential side effects. The development of precision and intelligent gas delivery nanomedicines can maximize the profits of gas therapy by enhancing the bio-availability and bio-safety of therapeutic gases.

More and more gas-releasing nanomedicines are being developed by virtue of multifunctional nanoplatforms, making it ever-increasingly expectable to make breakthrough in cancer treatment. Even so, there are still many gaps between gas therapy and nanomedicines, needing to be filled.

In a new overview published in the Beijing-based National Science Review, scientists at Shenzhen University, China propose a series of engineering strategies of advanced gas-releasing nanomedicines for augmented cancer therapy from four aspects, 1) stimuli-responsive strategies for controlled gas release, 2) catalytic strategies for controlled gas release, 3) tumor-targeted gas delivery strategies, 4) multi-model combination strategies based on gas therapy.

A May 6, 2020 China Science Press news release on EurekAlert, which originated the news item, provides a little more detail about the overview and about a future application as an assistive therapy in diseases such as coronovirus pneumonia,

“This review systematically dissects the roles of carrier and gas prodrug within nanomedicine for stimuli-responsive gas release, catalytic gas generation routes, tumor-targeted gas delivery approaches and gas therapy-based combination methods, and also provides an insight into their engineering principles and working mechanisms, and correspondingly proposed a series of superior engineering strategies of nanomedicines for gas therapy of cancer to guide the future research.” Dr. Yingshuai Wang said “We believe this review could provide inspiration for constructing advanced gas-releasing nanomedicines.”

Moreover, they have also pointed out current issues and gaps in knowledge, and have envisaged current trends and future prospects of advanced nanomedicines for gas therapy of cancer in this review.

“There are many gaps intriguing me, such as high tissue penetration stimuli-responsive gas release, the local, endless and prodrug-free generation of gases by catalysis, and the super ability of assisting other almost all therapies.” Prof. Qianjun He adds “It is noticeable, in the recent fight of novel coronavirus pneumonia, hydrogen therapy is playing an vitally important role in assisting large numbers of patients to improve oxygen inhalation, relieve hypoxia, and scavenge inflammation. I hope our hydrogen-producing medicines would make bigger contribution to human being in the near future.”

This illustration accompanies the news release,

Caption: Illustration of strategies for engineering advanced nanomedicines for augmented gas therapy of cancer. Credit: ©Science China Press

Here’s a link to and a citation for the paper,

Strategies for engineering advanced nanomedicines for gas therapy of cancer by Yingshuai Wang, Tian Yang, Qianjun He. National Science Review, nwaa034, https://doi.org/10.1093/nsr/nwaa034 Published: 27 February 2020

This appears to be an open access paper in PDF only.

For anyone new to the term, a prodrug is (Note: Links have been removed),

A prodrug is a medication or compound that, after administration, is metabolized (i.e., converted within the body) into a pharmacologically active drug.[1][2] Inactive prodrugs are pharmacologically inactive medications that are metabolized into an active form within the body. Instead of administering a drug directly, a corresponding prodrug might be used instead to improve how a medicine is absorbed, distributed, metabolized, and excreted (ADME).[3][4]

You can find out more in the Prodrug Wikipedia entry.