Nanobiomaterial boosts neuronal growth in mice with spinal cord injuries

Researchers from the Department of Orthopedics of Tongji Hospital at Tongji University in Shanghai have successfully used a nanobiomaterial called layered double hydroxide (LDH) to inhibit the inflammatory environment surrounding spinal cord injuries in mice, accelerating the regeneration of neurons and reconstruction of the neural circuit in the spine.

The researchers were also able to identify the underlying genetic mechanism by which LDH works. This understanding should allow further modification of the therapy, which, in combination with other elements, could finally produce a comprehensive, clinically applicable system for spinal cord injury relief in humans.

The research appeared in the American Chemical Society journal ACS Nano on February 2.

There is no effective treatment for spinal cord injuries, which are always accompanied by the death of neurons, breakage of axons or nerve fibers, and inflammation.

Even though the body continues to generate new neural stem cells, this inflammatory microenvironment (the immediate, small-scale conditions at the injury site) severely hinders the regeneration of neurons and axons. Worse still, the prolonged activation of immune cells in this area also results in secondary lesions of the nervous system, in turn preventing the stem cells from differentiating themselves into new cell types.

If this aggressive immune response at the injury site could be moderated, there is the possibility that neural stem cells could begin differentiation, and neural regeneration could occur.

In recent years, a raft of novel nano-scale biomaterials—natural or synthetic materials that interact with biological systems—have been designed to assist activation of neural stem cells, along with their mobilization and differentiation. Some of these “nanocomposites” are capable of delivering drugs to the injury site and accelerate neuronal regeneration.

These nanocomposites are especially attractive for spinal cord treatment due to their low toxicity. However, few have any ability to inhibit or moderate the immune reaction at the site, and so do not tackle the underlying problem. Moreover, the underlying mechanisms of how they work remain unclear.

Nanolayered double hydroxide (LDH) is a kind of clay with many interesting biological properties relevant to spinal cord injuries, including good biocompatibility (ability to avoid rejection by the body), safe biodegradation (breakdown and removal of the molecules after application), and excellent anti-inflammatory capability.

LDH has already been widely explored in biomedical engineering with respect to immune response regulation, but mainly in the field of anti-tumor therapy.

“These properties made LDH a really promising candidate for the creation of a much more beneficial microenvironment for spinal cord injury recovery,” says Rongrong Zhu of the Department of Orthopedics of Tongji Hospital, first author of the study.

Under the leadership of Liming Cheng, corresponding author of the study, the research team transplanted the LDH into the injury site of mice and found that the nanobiomaterial had significantly accelerated neural stem cells migration, neural differentiation, activation of channels for neuron excitation, and induction of action potential (nerve impulse) activation.

The mice also exhibited significantly improved locomotive behavior compared to the control group of mice. In addition, when the LDH was combined with Neurotrophin-3 (NT3), a protein that encourages the growth and differentiation of new neurons, the mice enjoyed even better recovery effects than the LDH on its own. In essence, the NT3 boosts neuronal development while the LDH creates an environment where that development is allowed to thrive.

Then, via transcriptional profiling, or analysis of gene expression of thousands of genes at once, the researchers were able to identify how the LDH performs its assistance.

They found that once LDH is attached to cell membranes, it provokes greater activation of the “transforming growth factor-β receptor 2” (TGFBR2) gene, decreasing the production of the white blood cells that enhance inflammation and increasing production of the white blood cells that inhibit inflammation.

Upon application of a chemical that inhibits TGFBR2, they found the beneficial effects were reversed.

The understanding of how LDH performs these effects should now allow the researchers to tweak the therapy to enhance its performance and to finally create a comprehensive therapeutic system for spinal cord injuries—combining these biomaterials with neurotrophic factors like NT3-that can be used in clinical application on people.

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Carbon Nanotubes: The Next Generation of Global Water Purification?

A typical day (maybe like yours) involves waking up, taking a 10 minute shower, cooking breakfast, running the dishwasher if it’s full, going to work, eating dinner with a refreshing glass of filtered water, and maybe tackling a load of laundry in the evening. None of these actions feel extravagant, but when I look at statistics of global water usage and the lack of fresh water availability, it’s obvious that as Americans, we consume significantly more gallons of water per day than anywhere else in the world. In fact, on average each American uses about 152 gallons of water daily, while people in some other countries such as Uganda and Haiti use only about 4 gallons.¹

That extreme low usage in some countries is not just because people are very conservation-minded – it is largely because there is not enough clean water to go around. Living in Wisconsin, I am conscientious of my water intake, but I am fortunate to not be in constant fear of turning on the faucet to see no water or even dirty water pouring out. Unfortunately, as we’ve learned from the recent experience of people in Flint, Michigan, it is not only countries outside the U.S. that have to worry about availability of clean water.

Personally, a trip to Israel last winter was what forced me to step out of my typical routine and experience firsthand how precious water is to their nation as a natural resource. My guide on the trip encouraged us to shower efficiently, never leave the water running while doing dishes, and to purchase bottled water, but to never waste a drop.

Enjoying the availability of fresh, clean water. (image by Elvert Barnes)

Being a scientist and an advocate for reducing my footprint on the environment, I wanted to learn more about what is being done to solve the problem of global freshwater availability. Considering what other recent medical and energy-related advancements have been made with the use of nanotechnology, it came as no surprise to me that carbon nanotubes (CNTs) are being studied as a means of water purification.

What exactly is a carbon nanotube? Picture a flat sheet of carbon atoms rolled into an incredibly tiny cylindrical tube with a diameter on the nanoscale, as shown here:

Carbon nanotube. (image from wikimedia commons)

These tiny, flexible, and surprisingly resilient materials may very well be our new direction in sustainable, large-scale water purification. The major advantage of CNTs is that water passes through them in a nearly frictionless manner due to something called hydrophobicity (i.e. preference to be away from water). But if CNTs are hydrophobic, you might wonder why water would even come near or enter them in the first place. This is an important point because water is a polar molecule and CNTs are non-polar, meaning they typically don’t want to mix together. One option for overcoming this is to coat the top of each tube with specific molecules that will initially attract water to the opening. Then, when water enters the nanotube, it flows through very quickly because it is being repelled by the hydrophobic tube walls. Conversely, most salts, ions, and pollutants won’t flow through the nanotube because they are attracted to and captured by the coating at the opening.

Also Read: Reusable carbon nanotubes could be the water filter of the future

Because water passes through the CNTs so easily and pollutants do not, CNTs have potential to be a great solution for water purification. If we’re able to use CNTs in the next generation of water purification technology, then we may be able to both desalinate (get rid of salt) and remove pollutants from otherwise unusable water around the world with less energy and less money than current methods require.

Improving water purification really is a global issue. On my trip last winter, I learned that Israel, along with other nations in the Middle East and Northern Africa, were already considered “water stressed” in 1995. This phrase indicates that the nation is withdrawing more than 25% of their renewable freshwater resources for agricultural, domestic, and industrial uses annually. By the year 2025 it is predicted that over 2.8 billion people in 48 countries will be “water stressed” or worse.² To combat this growing issue, countries are turning to unconventional options for wastewater treatment and desalination.

Freshwater stress map showing percentage ranges of how much water will be withdrawn with respect to amount naturally available.²

With a greater understanding of the problem at hand, let’s take a closer look at current techniques for water purification. Right now, the most common practice of cleansing salt water to produce freshwater is the use of desalination plants. These plants operate by the technique of reverse osmosis, which is shown in the figure below. Osmosis is when a less concentrated liquid (like fresh water) moves through a membrane toward a more concentrated liquid (water containing salt in this case). This process happens naturally without any need for applying external pressure. For reverse osmosis, we want the exact opposite to happen, and unlike osmosis, that requires an input of external energy. These semi-permeable reverse osmosis membranes that separate the two liquids are usually made of common organic materials with pores ranging from 0.3 to 0.6 nanometers in diameter. (As a comparison the diameter of a dime is 18,008,600 nanometers while the diameter of a water molecule is a mere 0.1 nm).

Differences between osmosis and reverse osmosis. (image by Emily Caudill)

As of 2013, there were over 17,000 plants worldwide providing more than 300 million people with desalinated water, many using reverse osmosis technology.³ Israel alone, with its relatively small land mass, has four plants with a fifth currently being built, while the U.S. houses about 250 plants.⁴

Desalination plants are effective, yet they are costly monetarily, energetically, and environmentally speaking. These plants require a great deal of energy input daily, and most desalination plants run on non-renewable energy sources (like fossil fuels and nuclear energy).⁵ With global freshwater availability declining, there is a need for cheaper, more efficient, and more environmentally sustainable desalination technology, and CNTs may be our most viable option looking forward. Their desalination capacity and frictionless water interaction means they require less energy than reverse osmosis to produce the same amount of fresh water.

Inside a reverse osmosis desalination plant  (image by James Grellier)

There are a few hurdles that must be overcome before we hear about the next “CNT desalination plant,” though. For example, we need to develop a method for large scale synthesis of CNTs that ensures consistent shape, size, and function. However, it is evident that our current methods of water purification aren’t enough and motivation is strong to develop this new use for CNTs.⁶

With increasing resources and technologies, we are closer than ever to a newer, faster, cheaper, and overall better way to provide fresh water on the global scale. Nanotechnology has proven to be a wonderful alternative to previously used methods in energy and medicine, for example, and we may be close to seeing a similar improvement in the case of water purification. As part of the Center for Sustainable Nanotechnology, I want to mention that it will be absolutely vital to produce and dispose of CNTs in a way that doesn’t lead to greater issues in the future (such as their own toxicity to the environment). This is an exciting time in science because we have groundbreaking approaches, but we are also in a day and age where we need to be more thoughtful about how our actions impact our finite supply of water, precious metals, and other vital resources.

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EDUCATIONAL RESOURCES

• Teach Engineering: Hands-On Activity: Water Filtration (grades 3-5)
• SafeWaterScience: Treatment of Water Teacher’s Guide (grades 5-8)
• National Nanotechnology Infrastructure Network: The Water Race: Hydrophobic & Hydrophilic Surfaces activity (high school)

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REFERENCES (may require subscription for full access)

1. The Water Information Program. Water Facts http://www.waterinfo.org/resources/water-facts.
2. United Nations Environment Program. Vital Water Graphics, retrieved from http://www.unep.org/dewa/vitalwater/article141.html.
3. International Desalination Association. Desalination by the Numbers http://idadesal.org/desalination-101/desalination-by-the-numbers/.
4. Texas Water Development Board. Seawater FAQs http://www.twdb.texas.gov/innovativewater/desal/faqseawater.asp.
5. Nuclear Energy Institue. Water Desalination
   http://www.nei.org/Knowledge-Center/Other-Nuclear-Energy-Applications/Water-Desalination
6. Das, R.; Ali, M. E.; Hamid, S. B. A.; Ramakrishna, S.; Chowdhury, Z. Z. Carbon nanotube membranes for water purification: a bright future in water desalination. Desalination, 2014, 336, 97-109. doi: 10.1016/j.desal.2013.12.026

China’s Dominance Of Clean Energy Supply Chains Raises Concerns

Over the past decade, no major energy source has grown faster than solar power. According to the 2020 BP Statistical Review of World Energy, installed solar photovoltaic (PV) capacity has grown at an average annual rate of over 42% over the past 10 years, translating into a doubling of global capacity every 1.7 years on average.

Although that blistering pace could start slowing down as installed capacity grows, solar will likely remain the fastest-growing energy source for the foreseeable future. Much as with other energy sources, however, solar growth is giving rise to a number of thorny questions regarding geopolitics, supply chains, and national security.

The Path to Decarbonization

From a North American perspective, the election of Joe Biden as U.S. President has breathed new life into the Paris climate agreement — the most significant global effort to rein in carbon dioxide emissions to date. Fulfilling a key campaign promise, President Biden officially rejoined the Paris accord last month. At the same time, following meetings between President Biden and Canadian Prime Minister Justin Trudeau, Canada also pledged to submit its own new target under the Paris pact, with the two leaders insisting on a joint approach to climate issues.

The European Union, for its part, has consistently maintained an aggressive stance toward carbon emission reductions. The EU is on a path to surpass its goal of generating a third of its energy from renewable sources by 2030. Last September, the European Commission presented its plan to reduce EU greenhouse gas emissions by at least 55% by 2030, compared to 1990 levels. That would put the EU on a path to reach climate neutrality by 2050.

All of these efforts point to one inescapable conclusion: installed renewable energy capacity will continue to rise as governments on both sides of the Atlantic pour money into decarbonization efforts.

At the same time, many of these countries are understandably sensitive about energy security. Political leaders don’t like to depend on other countries for their energy supplies, but this is frequently an accepted trade-off due to economic considerations.

That pattern has long held true for fossil fuels, with OPEC maintaining a stranglehold on the world’s oil supplies until the U.S. fracking boom somewhat weakened its monopoly. Now, as the renewable revolution picks up steam, one country – China – has built up a clear advantage around certain key renewable technologies, in particular the components needed to construct solar energy infrastructure in the West.

Huawei in the Spotlight

China’s own energy consumption continues to grow rapidly, making the Chinese economy the world’s largest energy consumer. As a result, Beijing invested aggressively in renewables and has now achieved predominant market shares in solar photovoltaics as well as lithium-ion batteries, another key renewable technology.

Chinese state-linked company Huawei, better known for telecommunications equipment and consumer electronics, has also become one of the world’s largest suppliers of solar inverters, a critical part of solar PV systems that converts direct current power generated by solar panels into alternating current electricity to power electronics in homes and businesses.

Huawei’s dominant position in the inverter market, coupled with the backing it enjoys from the Chinese government, has raised concerns in the U.S. In 2019, a bipartisan group of U.S. Senators sent letters to Energy Secretary Rick Perry and Department of Homeland Security Secretary Kirstjen Nielsen, urging them to ban the sale of all Huawei solar products in the U.S., citing a national security threat to U.S. energy infrastructure.

Noting that Congress had previously blocked Huawei from the U.S. telecommunications equipment market due to concerns over its links to China’s intelligence services, the letter stated in part:

“Both large-scale photovoltaic systems and those used by homeowners, school districts, and businesses are equally vulnerable to cyberattacks. Our federal government should consider a ban on the use of Huawei inverters in the United States and work with state and local regulators to raise awareness and mitigate potential threats.”

Comparing finite and renewable planetary energy reserves (Terawatt-years). Total recoverable reserves are shown for the finite resources. Yearly potential is shown for the renewables.

The concern is that if the U.S. power grid becomes dependent on a critical piece of state-linked Chinese electronic equipment, it could render that grid especially vulnerable to outside disruption or manipulation. This dynamic mirrors concerns in the U.S. about reliance on OPEC for oil supplies. Huawei responded to what it called an “unwelcoming climate being fostered in the United States” by closing its U.S. inverter business.

Europe’s Diverging Approach

A more ambivalent approach toward Huawei was initially adopted in the EU, which only agreed to reduce its dependency on equipment susceptible to Chinese government influence for future 5G networks. However, officials in a number of EU countries are now sounding an alarm over the Chinese state’s role in sectors of their economies that represent key national security interests, including banking, energy, and infrastructure.

Those concerns extend to solar energy, with EU policymakers also expressing concern over China’s use of Muslim forced labor in solar PV module supply chains. That issue has given additional impetus to the European Parliament, which is now pushing for trade bans on Chinese solar module equipment if human rights abuses are involved in their manufacture.

These factors all create major incentives for Western countries to address Chinese state dominance in the clean energy sector. That imbalance didn’t arise overnight, and it will take some time to address.

President Biden took a step in that direction by signing an executive order aimed at making U.S. supply chains more resilient. Among other things, the report calls for identifying “risks in the supply chain for high-capacity batteries, including electric-vehicle batteries, and policy recommendations to address these risks.”

The EU will now have to decide whether it is ready to pursue a similar approach. Clean energy supply chains haven’t received a lot of policy attention until recently, but governments are increasingly under pressure to ensure potential threats to those supply chains don’t derail global efforts to decarbonize.

Article from The Energy Collective Group: Robert Rapier

How Quantum Computing Could Remake Chemistry

Photo Credit: Andriy Onufriyenko  Article By Jeanette Garcia

In my career as a chemist, I owe a huge debt to serendipity. In 2012, I was in the right place (IBM’s Almaden research lab in California) at the right time—and I did the “wrong” thing. I was supposed to be mixing three components in a beaker in the hope of systematically uncovering a combination of chemicals, meaning to replace one of the chemicals with a version that was derived from plastic waste, in an effort to increase the sustainability of thermoset polymers.

Instead, when I mixed two of the reagents together, a hard, white plastic substance formed in the beaker. It was so tough I had to smash the beaker to get it out. Furthermore, when it sat in dilute acid overnight, it reverted to its starting materials. Without meaning to, I had discovered a whole new family of recyclable thermoset polymers. Had I considered it a failed experiment, and not followed up, we would have never known what we had made. It was scientific serendipity at its best, in the noble tradition of Roy Plunkett, who invented Teflon by accident while working on the chemistry of coolant gases.

Today, I have a new goal: to reduce the need for serendipity in chemical discovery. Nature is posing some real challenges in the world, from the ongoing climate crisis to the wake-up call of COVID-19. These challenges are simply too big to rely on serendipity. Nature is complex and powerful, and we need to be able to accurately model it if we want to make the necessary scientific advances.

Specifically, we need to be able to understand the energetics of chemical reactions with a high level of confidence if we want to push the field of chemistry forward. This is not a new insight, but it is one that highlights a major constraint: accurately predicting the behavior of even simple molecules is beyond the capabilities of even the most powerful computers.

This is where quantum computing offers the possibility of major advances in the coming years. Modeling energetic reactions on classical computers requires approximations, since they can’t model the quantum behavior of electrons over a certain system size. Each approximation reduces the value of the model and increases the amount of lab work that chemists have to do to validate and guide the model. Quantum computing, however, is now at the point where it can begin to model the energetics and properties of small molecules such as lithium hydride, LiH—offering the possibility of models that will provide clearer pathways to discovery than we have now.

THE QUANTUM CHEMISTRY LEGACY

Of course, quantum chemistry as a field is nothing new. In the early 20th century, German chemists such as Walter Heitler and Fritz London showed the covalent bond could be understood using quantum mechanics. In the late the 20th century, the growth in computing power available to chemists meant it was practical to do some basic modeling on classical systems.

Even so, when I was getting my Ph.D. in the mid-2000s at Boston College, it was relatively rare that bench chemists had a working knowledge of the kind of chemical modeling that was available via computational approaches such as density functional theory (DFT). The disciplines (and skill sets involved) were orthogonal. Instead of exploring the insights of DFT, bench chemists stuck to systematic approaches combined with a hope for an educated but often lucky discovery. I was fortunate enough to work in the research group of Professor Amir Hoveyda, who was early to recognize the value of combining experimental research with theoretical research.

THE DISCONTENTS OF COARSE DATA

Today, theoretical research and modeling chemical reactions to understand experimental results is commonplace, as the theoretical discipline became more sophisticated and bench chemists gradually began to incorporate these models into their work. The output of the models provides a useful feedback loop for in-lab discovery. To take one example, the explosion of available chemical data from high throughput screening has allowed for the creation of well-developed chemical models. Industrial uses of these models include drug discovery and material experimentation.

The limiting factor of these models, however, is the need to simplify. At each stage of the simulation, you have to pick a certain area where you want to make your compromise on accuracy in order to stay within the bounds of what the computer can practically handle. In the terminology of the field, you are working with “coarse-grained” models—where you deliberately simplify the known elements of the reaction in order to prioritize accuracy in the areas you are investigating. Each simplification reduces the overall accuracy of your model and limits its usefulness in the pursuit of discovery. To put it bluntly, the coarser your data, the more labor intensive your lab work.

The quantum approach is different. At its purest, quantum computing lets you model nature as it is; no approximations. In the oft-quoted words of Richard Feynman, “Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical.”

We’ve seen rapid advances in the power of quantum computers in recent years. IBM doubled its quantum volume not once but twice in 2020 and is on course to reach quantum volume of more than 1,000, compared with single-digit figures in 2016. Others in the industry have also made bold claims about the power and capabilities of their machines.

So far, we have extended the use of quantum computers to model energies related to the ground states and excited states of molecules. These types of calculations will lead us to be able to explore reaction energy landscapes and photo-reactive molecules. In addition, we’ve explored using them to model the dipole moment in small molecules, a step in the direction of understanding electronic distribution and polarizability of molecules, which can also tell us something about how they react.

Looking ahead, we’ve started laying the foundation for future modeling of chemical systems using quantum computers and have been exploring different types of calculations on different types of molecules soluble on a quantum computer today. For example, what happens when you have an unpaired electron in the system? Do the calculations lose fidelity, and how can we adjust the algorithm to get them to match the expected results? This type of work will enable us to someday look at radical species, which can be notoriously difficult to analyze in the lab or simulate classically.

To be sure, this work is all replicable on classical computers. Still, none of it would have been possible with the quantum technology that existed five years ago. The progress in recent years holds out the promise that quantum computing can serve as a powerful catalyst for chemical discovery in the near future.

QUANTUM MEETS CLASSICAL

I don’t envision a future where chemists simply plug algorithms into a quantum device and are given a clear set of data for immediate discovery in the lab. What is feasible—and may already be possible— would be incorporating quantum models as a step in the existing processes that currently rely on classical computers.

In this approach, we use classical methods for the computationally intensive part of a model. This could include an enzyme, a polymer chain or a metal surface. We then apply a quantum method to model distinct interactions—such as the chemistry in the enzyme pocket, explicit interactions between a solvent molecule and a polymer chain, or hydrogen bonding in a small molecule. We would still accept approximations in certain parts of the model but would achieve much greater accuracy in the most distinct parts of the reaction. We have already made important progress through studying the possibility of embedding quantum electronic structure calculation into a classically computed environment obtained at the Hartree-Fock (HF) or DFT level of theory.

The practical applications of advancing this approach are numerous and impactful. More rapid advances in the field of polymer chains could help address the problem of plastic pollution, which has grown more acute since China has cut its imports of recyclable material. The energy costs of domestic plastic recycling remain relatively high; if we can develop plastics that are easier to recycle, we could make a major dent in plastic waste. Beyond the field of plastics, the need for materials with lower carbon emissions is ever more pressing, and the ability to manufacture substances such as jet fuel and concrete with a smaller carbon footprint is crucial to reducing total global emissions.

MODELING THE FUTURE

The next generation of chemists emerging from grad schools across the world brings a level of data fluency that would have been unimaginable in the 2000s. But the constraints on this fluency are physical: classically built computers simply cannot handle the level of complexity of substances as commonplace as caffeine. In this dynamic, no amount of data fluency can obviate the need for serendipity: you will be working in a world where you need luck on your side to make important advances. The development of— and embrace of—quantum computers is therefore crucial to the future practice of chemists.

This is an opinion and analysis article.

Super Oil & Gas Company Total Orders Hydrogen Re-Fueling Station from HRS – A Hydrogen Fuel Success Story

Hydrogen Refueling Solutions (HRS) has announced that it has received an order from Total for the supply and installation of a hydrogen station at the site of one of its customers.

A European designer and manufacturer of hydrogen fueling stations, HRS is a success
story. Recently listed on the stock exchange, the Iserise company has just formalized an order related to the supply and installation of a hydrogen station for one of the total group’s customers.

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Engie and Total embark on massive production of green hydrogen

A hydrogen station delivered by June 2021

If hrS does not specify the location of this future station, it says it will be delivered and commissioned by June 2021.
Specially designed to meet the needs of Total’s teams, this station will be able to distribute up to 200 kilograms of hydrogen per day. Accessible to all types of vehicles, it will offer two levels of pressure: 350 and 700 bars. With a storage capacity of 190 kilos, it can be easily dismantled and transported.

(Quote) Philippe Callejon, Director of Mobility and New Energy of Total Marketing France,

“With this high-capacity, transportable HRS solution, Total is able to offer its customers an innovative solution of temporary rental offer turnkey and quickly deployable, to address their experimental operational needs (bus fleets, household dumpsters, heavy trucks, commercial vehicles …).” says