Posts belonging to Category Computational chemistry



Solar Nanotechnology-based Desalination

A new desalination system has been developed that combines membrane distillation technology and light-harvesting nanophotonics. Called nanophotonics-enabled solar membrane distillation technology, or NESMD for short, the development has come from the Center for Nanotechnology Enabled Water Treatment (NEWT), based at Rice University. The system works whereby hot salt water is flowed across one side of a porous membrane and cold freshwater is flowed across the otherWater vapor is naturally drawn through the membrane from the hot to the cold side, and because the seawater doesn’t need to be boiled, the energy requirements are less than they would be for traditional distillation, according to the researchers. However, the energy costs are still significant because heat is continuously lost from the hot side of the membrane to the cold.

Unlike traditional membrane distillation, NESMD benefits from increasing efficiency with scale,” said Rice’s Naomi Halas, a corresponding author on the paper and the leader of NEWT‘s  nanophotonics research efforts. “It requires minimal pumping energy for optimal distillate conversion, and there are a number of ways we can further optimise the technology to make it more productive and efficient.

The distillation membrane in the chamber contained a specially designed top layer of carbon black nanoparticles infused into a porous polymer. The light-capturing nanoparticles heated the entire surface of the membrane when exposed to sunlight. A thin half-millimeter-thick layer of salt water flowed atop the carbon-black layer, and a cool freshwater stream flowed below.

Rice scientist and water treatment expert Qilin Li said the water production rate increased greatly by concentrating the sunlight: “The intensity got up 17.5 kilowatts per meter squared when a lens was used to concentrate sunlight by 25 times, and the water production increased to about 6 liters per meter squared per hour.”

In the PNAS study, researchers offered proof-of-concept results based on tests with an NESMD chamber about the size of three postage stamps and just a few millimeters thick.

Source: http://www.waterworld.com/

The Fountain Of Youth

It’s been a dream of civilizations since the dawn of time: If we can’t live forever, can we at least slow down the aging process and stretch our lives out as long as possible? Now, researchers from Brigham Young University (BYU) say they’ve found that a certain type of physical exercise can slow the aging process within our cells. That ultimately means better health, and physical conditioning that matches the natural age progression of a significantly younger person–as many as nine years younger.

105 years old Champion French cyclist

If it’s not quite the fountain of youth, it’s an intriguing step toward it. I’m also the first to admit that such a big claim deserves a skeptical eye. So let’s dive right into the study and examine what the researchers claim–along with exactly how much exercise we’re talking about here to achieve the results.

 

Researchers at BYU, led by a professor of exercise science named Larry Tucker, studied 5,823 adults who had participated in a Centers for Disease Control and Prevention (CDC) research project called the National Health and Nutrition Examination Survey. Among many other things, this study kept track of the participants’ daily physical activity. Specifically, it tracked the degree to which these people engaged in 62 types of exercise over a 30-day period.

The CDC study also measured something called “telomere length values.” Telomeres are “the nucleotide endcaps of our chromosomes,” as a BYU press release explained it, continuing: They’re like our biological clock and they’re extremely correlated with age; each time a cell replicates, we lose a tiny bit of the endcaps. Therefore, the older we get, the shorter our telomeres.

Here’s where it gets interesting. By poring through the data in the CDC study, BYU‘s Tucker claims that he was able to correlate people’s relative telomere length with their various levels of physical activity–and he found a surprise. If you think of people’s levels of physical activity as being in four categoriessedentary, low, moderate, and high–Tucker found that people in the first three categories had roughly similar telomere lengths.

But for that last category, the people who engaged in high levels of physical activity had “140 base pairs of DNA [more] at the end of their telomeres” than everyone else. According to Tucker’s paper, which was published in the July 2017 edition of Preventive Medicine, that results in a “biologic aging advantage of nine years.” To put this plainly and in layman’s terms, engage in high levels of physical activity, and your cells are more likely to resemble the cells of a considerably younger person. The BYU researchers had to draw a line somewhere, so for purposes of their study they defined “high levels of physical activity” to mean engaging in 30 minutes of jogging for women, or 40 minutes of jogging for men–and to do it five days per week. That’s the kind of level that requires a commitment, but probably isn’t beyond the abilities of anyone who wants to make a decision to become healthier. And, of course, this isn’t the first study by any means to attempt to find the link between increased exercise, better health, and longer life.

Recently, for example, researchers at the Mayo Clinic reached a similar conclusion for different reasons, finding that people who engaged regularly in high-intensity interval training had cells that were more efficient at creating new proteins–which in turn results in “reversing a major adverse effect of aging.”

Source: https://magazine.byu.edu/
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How To Repair Connections Between Nerve Cells

Carbon nanotubes exhibit interesting characteristics rendering them particularly suited to the construction of special hybrid devices – consisting of biological tissue and synthetic material – planned to re-establish connections between nerve cells, for instance at spinal level, lost on account of lesions or trauma. This is the result of a piece of research published on the scientific journal Nanomedicine: Nanotechnology, Biology, and Medicine conducted by a multi-disciplinary team comprising SISSA (International School for Advanced Studies), the University of Trieste, ELETTRA Sincrotrone and two Spanish institutions, Basque Foundation for Science and CIC BiomaGUNE. More specifically, researchers have investigated the possible effects on neurons of the interaction with carbon nanotubes. Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process. This result, which shows the extent to which the integration between nerve cells and these synthetic structures is stable and efficient, highlights the great potentialities of carbon nanotubes as innovative materials capable of facilitating neuronal regeneration or in order to create a kind of artificial bridge between groups of neurons whose connection has been interrupted. In vivo testing has actually already begun.

Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process

Interface systems, or, more in general, neuronal prostheses, that enable an effective re-establishment of these connections are under active investigation” explain Laura Ballerini (SISSA) and Maurizio Prato (UniTSCIC BiomaGUNE), coordinating the research project. “The perfect material to build these neural interfaces does not exist, yet the carbon nanotubes we are working on have already proved to have great potentialities. After all, nanomaterials currently represent our best hope for developing innovative strategies in the treatment of spinal cord injuries“. These nanomaterials are used both as scaffolds, a supportive framework for nerve cells, and as means of interfaces releasing those signals that empower nerve cells to communicate with each other.

Source: https://eurekalert.org/

Artificial Intelligence At The Hospital

Diagnosing cancer is a slow and laborious process. Here researchers at University Hospital Zurich painstakingly make up biopsy slides – up to 50 for each patient – for the pathologist to examine for signs of prostate cancer. A pathologist takes around an hour and a half per patient – a task IBMs Watson supercomputer is now doing in fractions of a second.

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“If the pathologist becomes faster by using such a system I think it will pay off. Because my time is also worth something. If I sit here one and a half hours looking at slides, screening all these slides, instead of just signing out the two or three positive ones, and taking into account that there may be a .1 error rate, percent error rate. this will pay off, because I can do in one and a half hours at the end five patients,” says Dr. Peter Wild, University Hospital Zürich.

The hospital’s archive of biopsy images is being slowly fed into Watson – a process that will take years. But maybe one day pathologists won’t have to view slides through a microscope at all. Diagnosis is not the only area benefiting from AI. The technology is helping this University of Sheffield team design a new drug that could slow down the progress of motor neurone disease. A system built by British start-up BenevolentAI is identifying new areas for further exploration far faster than a person could ever hope to.

Benevolent basically uses their artificial intelligence system to scan the whole medical and biomedical literature. It’s not really easy for us to stay on top of millions of publications that come out every year. So they can interrogate that information, using artificial intelligence and come up with ideas for new drugs that might be used in a completely different disease, but may be applicable on motor neurone disease. So that’s the real benefit in their system, the kind of novel ideas that they come up with,” explains Dr. Richard Mead, Sitran, University of Sheffield. BenevolentAI has raised one hundred million dollars in investment to develop its AI system, and help revolutionise the pharmaceutical industry.

Source: http://www.reuters.com/

Skin Regeneration

A small U.S. biotech has successfully regenerated skin and stimulated hair growth in pigs with burns and abrasions, paving the way for a scientific breakthrough that could lead to the regeneration of fully functional human skinSalt Lake City-based PolarityTE Inc‘s patented approach to tissue engineering is designed to use a patient’s own healthy tissue to re-grow human skin for the treatment of burns and wounds. Despite recent advances in reconstructive surgery, plastic surgeons cannot give burn victims what they require the most — their skin. Current approaches to treat serious burns are “severely limited” in their effectiveness and in some cases, are rather expensive, PolarityTE‘s founder and CEO Denver Lough said in an interview.

Epicel, a skin graft widely used in burn units that is sold by Cambridge, Massachusetts-based Vericel Corp, does not result in fully thick and functional skin — which is PolarityTE‘s objective.

“If clinically successful, the PolarityTE platform could deliver the first scientific breakthrough in wound healing and reconstructive surgery in nearly half a century,” said Lough, who served as senior plastic surgery resident at Johns Hopkins Hospital before creating PolarityTE last year.

“PolarityTE expects to begin a human trial later this year and the cell therapy could hit the market 12 to 18 months thereafter”.

PolarityTE conducted its pre-clinical study on wounded pigs at an animal facility in Utah. The use of therapy resulted in scar-less healing, growth of hair follicles, complete wound coverage and the progressive regeneration of all skin layers, the company said. As pig skin is more complex and robust than human skin, successful swine data is typically seen as a precursor to effectiveness in human trials.

The technology also has the potential to develop fully-functional tissues, including bone, muscle, cartilage and the liver, PolarityTE said.

Source: http://www.polarityte.com/
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Cellulose-based Ink For 3D Printing

Empa (Switzerland) researchers have succeeded in developing an environmentally friendly ink for 3D printing based on cellulose nanocrystals. This technology can be used to fabricate microstructures with outstanding mechanical properties, which have promising potential uses in implants and other biomedical applications.

Cellulose, along with lignin and hemicellulose, is one of the main constituents of wood. The biopolymer consists of glucose chains organized in long fibrous structures. In some places the cellulose fibrils exhibit a more ordered structure.

In order to produce 3D microstructured materials for composite applications, for instance, Empa researchers have been using a 3D printing method called “Direct Ink Writing” for the past year. During this process, a viscous substance – the printing ink – is squeezed out of the printing nozzles and deposited onto a surface, pretty much like a pasta machine. Empa researchers Gilberto Siqueira and Tanja Zimmermann from the Laboratory for Applied Wood Materials have now succeeded, together with Jennifer Lewis from Harvard University and André Studart from the ETH Zürich, in developing a new, environmentally friendly 3D printing ink made from cellulose nanocrystals (CNC).
The places with a higher degree of order appear in a more crystalline form. And it is these sections, which we can purify with acid, that we require for our research“, explains Siqueira. The final product is cellulose nanocrystals, tiny rod-like structures that are 120 nanometers long and have a diameter of 6.5 nanometers. And it is these nanocrystals that researchers wanted to use to create a new type of environmentally friendly 3D printing ink.They have now succeeded that  their new inks contain a full 20 percent CNC.

The biggest challenge was in attaining a viscous elastic consistency that could also be squeezed through the 3D printer nozzles“, says Siqueira. The ink must be “thick” enough so that the printed material stays “in shape” before drying or hardening, and doesn’t immediately melt out of shape again.

Source: https://www.empa.ch/

How Yo Make Sea Water Drinkable

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved. New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves. Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.

The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.

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Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” says Professor Rahul Raveendran Nair.

The new findings from a group of scientists at The University of Manchester have been published in the journal Nature Nanotechnology.

Source: http://www.manchester.ac.uk/
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Startup Promises Immortality Through AI, Nanotechnology, and Cloning

One of the things humans have plotted for centuries is escaping death, with little to show for it, until now. One startup called Humai has a plan to make immortality a reality. The CEO, Josh Bocanegra says when the time comes and all the necessary advancements are in place, we’ll be able to freeze your brain, create a new, artificial body, repair any damage to your brain, and transfer it into your new body. This process could then be repeated in perpetuityHUMAI stands for: Human Resurrection through Artificial Intelligence. The technology to accomplish this isn’t here now, but on the horizon. Bocanegra says they’ll reach this Promethean feat within 30 years. 2045 is currently their target date. So how do they plan to do it?

We’re using artificial intelligence and nanotechnology to store data of conversational styles, behavioral patterns, thought processes and information about how your body functions from the inside-out. This data will be coded into multiple sensor technologies, which will be built into an artificial body with the brain of a deceased human, explains the website.

Source: https://www.facebook.com/humaitech/
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Rechargeable Lithium Metal Battery

Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem.

The Rice battery stores lithium in a unique anode, a seamless hybrid of graphene and carbon nanotubes. The material first created at Rice in 2012 is essentially a three-dimensional carbon surface that provides abundant area for lithium to inhabit. Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites.

The anode itself approaches the theoretical maximum for storage of lithium metal while resisting the formation of damaging dendrites or “mossy” deposits.

Dendrites have bedeviled attempts to replace lithium-ion with advanced lithium metal batteries that last longer and charge faster. Dendrites are lithium deposits that grow into the battery’s electrolyte. If they bridge the anode and cathode and create a short circuit, the battery may fail, catch fire or even explode.

Rice researchers led by chemist James Tour found that when the new batteries are charged, lithium metal evenly coats the highly conductive carbon hybrid in which nanotubes are covalently bonded to the graphene surface. As reported in the American Chemical Society journal ACS Nano, the hybrid replaces graphite anodes in common lithium-ion batteries that trade capacity for safety.

Lithium-ion batteries have changed the world, no doubt,” Tour said, “but they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.

He said the new anode’s nanotube forest, with its low density and high surface area, has plenty of space for lithium particles to slip in and out as the battery charges and discharges. The lithium is evenly distributed, spreading out the current carried by ions in the electrolyte and suppressing the growth of dendrites.

Source: http://news.rice.edu

Coral That Beats Global Warming

Coral reefs in the Red Sea’s Gulf of Aqaba can resist rising water temperatures. If they survive local pollution, these corals may one day be used to re-seed parts of the world where reefs are dying. The scientists urge governments to protect the Gulf of Aqaba ReefsCoral reefs are dying on a massive scale around the world, and global warming is driving this extinction. The planet’s largest reef, Australia’s Great Barrier Reef, is currently experiencing enormous coral bleaching for the second year in a row, while last year left only a third of its 2300-km ecosystem unbleached. The demise of coral reefs heralds the loss of some of the planet’s most diverse ecosystems. Scientists have shown that corals in the Gulf of Aqaba in the Northern Red Sea are particularly resistant to the effects of global warming and ocean acidification. The implications are important, as the Gulf of Aqaba is a unique coral refuge. The corals may provide the key to understanding the biological mechanism that leads to thermal resistance, or the weakness that underlies massive bleaching. There is also the hope that the Gulf of Aqaba Reefs could be used to re-seed deteriorated reefs in the Red Sea and perhaps even around the world.

Scientists at EPFL (Ecole polytechnique fédérale de Lausanne) and UNIL (Université de Lausanne) in Switzerland, and Bar Ilan University and the InterUniversity Institute of Marine Sciences in Israel, performed the very first detailed physiological assessment of corals taken from the Gulf of Aqaba after exposure to stressful conditions over a six-week period. They found that the corals did not bleach.

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Under these conditions,  most corals around the world would probably bleach and have a high degree of mortality,” says EPFL scientist Thomas Krueger. “Most of the variables that we measured actually improved, suggesting that these corals are living under suboptimal temperatures right now and might be better prepared for future ocean warming.”

The results are published today in the journal Royal Society Open Science.

Source: https://actu.epfl.ch/

Self-Healing Lithium-Ion Batteries

Researchers at the University of Illinois have found a way to apply self-healing technology to lithium-ion batteries to make them more reliable and last longer.

The group developed a battery that uses a silicon nanoparticle composite material on the negatively charged side of the battery and a novel way to hold the composite together – a known problem with batteries that contain silicon.

Materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White led the study published in the journal Advanced Energy Materials.

“This work is particularly new to self-healing materials research because it is applied to materials that store energy,” White said. “It’s a different type of objective altogether. Instead of recovering structural performance, we’re healing the ability to store energy.”

The negatively charged electrode, or anode, inside the lithium-ion batteries that power our portable devices and electric cars are typically made of a graphite particle composite. These batteries work well, but it takes a long time for them to power up, and over time, the charge does not last as long as it did when the batteries were new.

Silicon has such a high capacity, and with that high capacity, you get more energy out of your battery, except it also undergoes a huge volume expansion as it cycles and self-pulverizes,” Sottos explained.

Past research found that battery anodes made from nanosized silicon particles are less likely to break down, but suffer from other problems.

You go through the charge-discharge cycle once, twice, three times, and eventually you lose capacity because the silicon particles start to break away from the binder,” White said.

To combat this problem, the group further refined the silicon anode by giving it the ability to fix itself on the fly. This self-healing happens through a reversible chemical bond at the interface between the silicon nanoparticles and polymer binder.

Source: https://news.illinois.edu/

Wood Mixed With Nanoparticles Filters Toxic Water

Engineers at the University of Maryland have developed a new use for wood: to filter water. Liangbing Hu of the Energy Research Center and his colleagues added nanoparticles to wood, then used it to filter toxic dyes from water.

The team started with a block of linden wood, which they then soaked in palladium – a metal used in cars’ catalytic converters to remove pollutants from the exhaust. In this new filter, the palladium bonds to particles of dye. The wood’s natural channels, that once moved water and nutrients between the leaves and roots, now allow the water to flow past the nanoparticles for efficient removal of the toxic dye particles. The water, tinted with methylene blue, slowly drips through the wood and comes out clear.

VIDEO: Wood filter removes toxic dye from water

This could be used in areas where wastewater contains toxic dye particles,” said Amy Gong, a materials science graduate student, and co-first author of the research paper.

The purpose of the study was to analyze wood via an engineering lens. The researchers did not compare the filter to other types of filters; rather, they wanted to prove that wood can be used to remove impurities.

We are currently working on using a wood filter to remove heavy metals, such as lead and copper, from water,’ said Liangbing Hu, the lead researcher on the project. “We are also interested in scaling up the technology for real industry applications.” Hu is a professor of materials science and a member of the University of Maryland’s Energy Research Center.

Source: http://www.mse.umd.edu/