Posts belonging to Category Computational chemistry



Liquid Storage Of The Sun’s Power

Researchers at Chalmers University of Technology in Sweden have demonstrated efficient solar energy storage in a chemical liquid. The stored energy can be transported and then released as heat whenever needed. ​Many consider the sun the energy source of the future. But one challenge is that it is difficult to store solar energy and deliver the energy ‘on demand’.

The research team from Chalmers University has shown that it is possible to convert the solar energy directly into energy stored in the bonds of a chemical fluid – a so-called molecular solar thermal system. The liquid chemical makes it possible to store and transport the solar energy and release it on demand, with full recovery of the storage medium. The process is based on the organic compound norbornadiene that upon exposure to light converts into quadricyclane.
CLICK ON THE IMAGE TO ENJOY THE VIDEO

The technique means that we can store the solar energy in chemical bonds and release the energy as heat whenever we need it,’ says Professor Kasper Moth-Poulsen, who is leading the research team. ‘Combining the chemical energy storage with water heating solar panels enables a conversion of more than 80 percent of the incoming sunlight.’

The research project was initiated at Chalmers more than six years ago and the research team contributed in 2013 to a first conceptual demonstration. At the time, the solar energy conversion efficiency was 0.01 percent and the expensive element ruthenium played a major role in the compound. Now, four years later, the system stores 1.1 percent of the incoming sunlight as latent chemical energy – an improvement of a factor of 100. Also, ruthenium has been replaced by much cheaper carbon-based elements.

We saw an opportunity to develop molecules that make the process much more efficient,’ says Moth-Poulsen. ‘At the same time, we are demonstrating a robust system that can sustain more than 140 energy storage and release cycles with negligible degradation.’

The research is presented on the cover of the scientific journal Energy & Environmental Science.

Source: http://www.reuters.com/
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https://www.chalmers.se/

Nanoparticles From Air Pollution Travel Into Blood To Cause Heart Disease

Inhaled nanoparticles – like those released from vehicle exhausts – can work their way through the lungs and into the bloodstream, potentially raising the risk of heart attack and stroke, according to new research part-funded by the British Heart Foundation. The findings, published today in the journal ACS Nano, build on previous studies that have found tiny particles in air pollution are associated with an increased risk of cardiovascular disease, although the cause remains unproven. However, this research shows for the first time that inhaled nanoparticles can gain access to the blood in healthy individuals and people at risk of stroke. Most worryingly, these nanoparticles tend to build-up in diseased blood vessels where they could worsen coronary heart disease – the cause of a heart attack.

It is not currently possible to measure environmental nanoparticles in the blood. So, researchers from the University of Edinburgh, and the National Institute for Public Health and the Environment in the Netherlands, used a variety of specialist techniques to track the fate of harmless gold nanoparticles breathed in by volunteers. They were able to show that these nanoparticles can migrate from the lungs and into the bloodstream within 24 hours after exposure and were still detectable in the blood three months later. By looking at surgically removed plaques from people at high risk of stroke they were also able to find that the nanoparticles accumulated in the fatty plaques that grow inside blood vessels and cause heart attacks and strokesCardiovascular disease (CVD) – the main forms of which are coronary heart disease and stroke – accounts for 80% of all premature deaths from air pollution.

Blood_Heart_Circulation

It is striking that particles in the air we breathe can get into our blood where they can be carried to different organs of the body. Only a very small proportion of inhaled particles will do this, however, if reactive particles like those in air pollution then reach susceptible areas of the body then even this small number of particles might have serious consequences,”  said Dr Mark Miller, Senior Research Fellow at the University of Edinburgh who led the study.

Source: http://www.cvs.ed.ac.uk/

Coldest City Grow Tomatoes All Year Round

Greenhouse invented by a Japanese company allows what’s often called the coldest city on earth to grow tomatoes when temperatures drop to -50 Celsius. Yakutsk in Siberia is one of the coldest cities in the world. During the freezing winter months it averages a temperature of minus 34 degrees Celcius with only five hours of daylight. That means crops can’t be grown in the frozen soil. But local authorities now believe they’ve found a way around that. They’ve teamed up with Japanese firm Hokkaido Corporation to build greenhouses with special technology. The local mayor hopes the project will go a long way to providing the fruit and veg needed by Yakutsk‘s people.

tomatoesCLICK ON THE IMAGE TO ENJOY THE VIDEO

When the entire infrastructure is ready, when the first and the second of the greenhouses are complete and we reach full capacity, then we plan to harvest around 1700 tonnes of cucumbers, more than 600 tonnes of tomatoes and around 25 tonnes of greens which should satisfy about 30-40 percent of the Yakutsk population’s needs,” says Aisen Nikolaev, the Mayor of Yakutsk.  The greenhouses are specially designed to withstand the extreme cold. Three layers of a rubber made from rubber with frozen soil properties are used.

It is three times thinner, but at the same time it can be stretched widely. It takes seven tonnes of weight per square metre piece for the film to break. And of course it has unique thermal insulation qualities and it lets the sunlight through better than ordinary glass. Just three layers of this thinnest film managed to last through this winter with temperatures dropping below minus 50 Celsius,”  explains the Mayor. Until now most produce had to be transported from Russia‘s Krasnodor region or imported from China. But now, if the technology proves a success, the tomatoes won’t have to travel too far to feed Yakutsk.

Source: http://www.reuters.com/

How To Prevent Metastasis In Pancreatic Cancer

UCLA scientists have unlocked an important mechanism that allows chemotherapy-carrying nanoparticles—extremely small objects between 1 and 100 nanometers (a billionth of a meter)—to directly access pancreatic cancer tumors, thereby improving the ability to kill cancer cells and hence leading to more effective treatment outcome of the disease. The researchers also confirmed the key role of a peptide (an extremely small protein) in regulating vascular access of the nanoparticle to the cancer site.

The discovery is the result of a two-year study co-led by Drs. Huan Meng and André Nel, members of UCLA‘s Jonsson Comprehensive Cancer Center and the UCLA California NanoSystems Institute. The findings are important as they demonstrate how the delivery of chemotherapy to pancreatic cancer can be improved significantly through the use of smart-designed nanoparticle features.

Pancreatic ductal adenocarcinoma is generally a fatal disease, with a five-year survival rate of less than 6 percent. The introduction of nanocarriers as delivery vehicles for common chemotherapy agents such as the drug irinotecan, has led to improved survival of patients with this disease. However, the reality is that nanocarriers may not always reach their intended target in sufficient numbers because of a constraint on their ability to transit through the blood vessel wall at the tumor site, leading the encapsulated drugs to be diverted or lost before they can deliver their payload.

silica nanoparticle

A key challenge for scientists is how to help nanoparticles travel to and be retained at tumor sites. This can be accomplished by custom-designed or engineered nanoparticles that overcome common challenges, such as the presence of a dense tissue surrounding the pancreas cancer cells. Prior research has identified a major vascular access mechanism that relies on a vesicle transport system, which can be turned with a peptide called iRGD in the blood vessel wall. iRGD is therefore potentially useful to optimize the delivery of cancer drugs by the nanoparticle to the tumor.

The UCLA research team designed a nanoparticle comprised of a hollow silica core surrounded by a lipid bilayer to enhance the delivery of irinotecan in an animal model with pancreatic cancer. The invention is called a silicasome. The researchers proposed that the therapeutic benefit of the irinotecan containing nanoparticles may be enhanced when combined with the injection of iRGD. The investigators used the nanoparticle plus the iRGD to deliver irinotecan in a robust animal model for pancreatic cancer that closely mimics human disease.

The study is published online in the Journal of Clinical Investigation.

Source: http://www.cancer.ucla.edu/

Nanoparticles reprogram immune cells to fight cancer

Dr. Matthias Stephan has a bold vision. He imagines a future where patients with leukemia could be treated as early as the day they are diagnosed with cellular immunotherapy that’s available in their neighborhood clinic and is as simple to administer as today’s chemotherapy, but without the harsh side effects. The key to that scientific leap? Nanoparticles, tiny technology that’s able to carry tumor-targeting genes directly to immune cells still within the body and program them to destroy cancer. In a proof-of-principle study published Monday in Nature Nanotechnology, Stephan and other researchers at Fred Hutchinson Cancer Research Center showed that nanoparticle-programmed immune cells, known as T cells, can clear or slow the progression of leukemia in a preclinical model.

nanoparticles reprogram genes

“Our technology is the first that we know of to quickly program tumor-recognizing capabilities into T cells without extracting them for laboratory manipulation,” said Stephan, the study’s senior author. Although his method for programming T cells is still several steps away from the clinic, Stephan envisions a future in which biodegradable nanoparticles could transform cell-based immunotherapies — whether for cancer or infectious disease — into an easily administered, off-the-shelf treatment that’s available anywhere.

Stephan imagines that in the future, nanoparticle-based immunotherapy could be “something that is available right away and can hopefully out-compete chemotherapies. That’s my excitement.”

Source: https://www.fredhutch.org/

How To Capture Quickly Cancer Markers

A nanoscale product of human cells that was once considered junk is now known to play an important role in intercellular communication and in many disease processes, including cancer metastasis. Researchers at Penn State have developed nanoprobes to rapidly isolate these rare markers, called extracellular vesicles (EVs), for potential development of precision cancer diagnoses and personalized anticancer treatments.

Lipid nanoprobes

Most cells generate and secrete extracellular vesicles,” says Siyang Zheng, associate professor of biomedical engineering and electrical engineering. “But they are difficult for us to study. They are sub-micrometer particles, so we really need an electron microscope to see them. There are many technical challenges in the isolation of nanoscale EVs that we are trying to overcome for point-of-care cancer diagnostics.”

At one time, researchers believed that EVs were little more than garbage bags that were tossed out by cells. More recently, they have come to understand that these tiny fat-enclosed sacks — lipids — contain double-stranded DNA, RNA and proteins that are responsible for communicating between cells and can carry markers for their origin cells, including tumor cells. In the case of cancer, at least one function for EVs is to prepare distant tissue for metastasis.

The team’s initial challenge was to develop a method to isolate and purify EVs in blood samples that contain multiple other components. The use of liquid biopsy, or blood testing, for cancer diagnosis is a recent development that offers benefits over traditional biopsy, which requires removing a tumor or sticking a needle into a tumor to extract cancer cells. For lung cancer or brain cancers, such invasive techniques are difficult, expensive and can be painful.

Noninvasive techniques such as liquid biopsy are preferable for not only detection and discovery, but also for monitoring treatment,” explains Chandra Belani, professor of medicine and deputy director of the Cancer Institute,Penn State College of Medicine, and clinical collaborator on the study.

We invented a system of two micro/nano materials,” adds Zheng. “One is a labeling probe with two lipid tails that spontaneously insert into the lipid surface of the extracellular vesicle. At the other end of the probe we have a biotin molecule that will be recognized by an avidin molecule we have attached to a magnetic bead.”

Source: http://news.psu.edu/

Artificial Embryo From Stem Cells

Scientists at the University of Cambridge have managed to create a structure resembling a mouse embryo in culture, using two types of stem cells – the body’s ‘master cells’ – and a 3D scaffold on which they can grow. Understanding the very early stages of embryo development is of interest because this knowledge may help explain why a significant number of human pregnancies fail at this time.

Once a mammalian egg has been fertilised by a sperm, it divides multiple times to generate a small, free-floating ball of stem cells. The particular stem cells that will eventually make the future body, the embryonic stem cells (ESCs) cluster together inside the embryo towards one end: this stage of development is known as the blastocyst. The other two types of stem cell in the blastocyst are the extra-embryonic trophoblast stem cells (TSCs), which will form the placenta, and primitive endoderm stem cells that will form the so-called yolk sac, ensuring that the foetus’s organs develop properly and providing essential nutrients.

Using a combination of genetically-modified mouse ESCs and TSCs, together with a 3D scaffold known as an extracellular matrix, Cambridge researchers were able to grow a structure capable of assembling itself and whose development and architecture very closely resembled the natural embryo.  There is a  remarkable degree of communication between the two types of stem cell: in a sense, the cells are telling each other where in the embryo to place themselves.

artificial embryo

We knew that interactions between the different types of stem cell are important for development, but the striking thing that our new work illustrates is that this is a real partnership – these cells truly guide each other,”  says Professor Zernicka-Goetz. “Without this partnership, the correct development of shape and form and the timely activity of key biological mechanisms doesn’t take place properly.”

Comparing their artificial ‘embryo’ to a normally-developing embryo, the team was able to show that its development followed the same pattern of development. The stem cells organise themselves, with ESCs at one end and TSCs at the other.

The study has been published in the journal Science.

Source: http://www.cam.ac.uk/

Quadriplegic Man Moves Again Just By Thinking

Bill Kochevar grabbed a mug of water, drew it to his lips and drank through the straw. His motions were slow and deliberate, but then Kochevar hadn’t moved his right arm or hand for eight years. And it took some practice to reach and grasp just by thinking about it. Kochevar, who was paralyzed below his shoulders in a bicycling accident, is believed to be the first person with quadriplegia in the world to have arm and hand movements restored with the help of two temporarily implanted technologies.

A brain-computer interface with recording electrodes under his skull, and a functional electrical stimulation (FES) system activating his arm and hand, reconnect his brain to paralyzed muscles. Holding a makeshift handle pierced through a dry sponge, Kochevar scratched the side of his nose with the sponge. He scooped forkfuls of mashed potatoes from a bowl—perhaps his top goal—and savored each mouthful. Kochevar (56, of Cleveland) is the focal point of research led by Case Western Reserve University, the Cleveland Functional Electrical Stimulation (FES) Center at the Louis Stokes Cleveland VA Medical Center and University Hospitals Cleveland Medical Center (UH).


brain implant2

For somebody who’s been injured eight years and couldn’t move, being able to move just that little bit is awesome to me,” said Kochevar. “It’s better than I thought it would be.”

 

He’s really breaking ground for the spinal cord injury community,” commented Bob Kirsch, chair of Case Western Reserve’s Department of Biomedical Engineering, executive director of the FES Center and principal investigator (PI) and senior author of the research. “This is a major step toward restoring some independence.”

A study of the work has been published in the The Lancet.

Source: http://thedaily.case.edu/

A Smartphone App To Loose Weight

Psychologists at the University of Exeter (UK) have found that less than ten minutes a day of ‘brain training’ using a game they have devised can slow impulses to reach for unhealthy snacks, and reduce calorie intake. Using neuroscience and lab trials to devise a proven method of curbing unhealthy food intake, Professor Natalia Lawrence’s Food Trainer app is being launched this week free to the public, in a month when people traditionally make resolutions to lose weight and cut down on junk foodDr Natalia Lawrence is a cognitive neuroscientist at Exeter University. She designed the app after using brain imaging to study how the brain’s reward system responded to pictures of unhealthy food.

food trainer

It’s very exciting to see that our free and simple training can change eating habits and have a positive impact on some people’s lives,” she said. “It’s a tool to help people make healthier choices. In an age where unhealthy food is so abundant and easily available and obesity is a growing health crisis, we need to design innovative ways to support people to live more healthily. We are optimistic that the way this app is devised will actually encourage people to opt for healthy food such as fruit and vegetables rather than junk food.

Among those to have used the training is Fiona Furness, a studios manager for a charity providing studios for artists, who went from around 11 stone to around nine stone after taking part in a trial of the food training game. She said the “pounds just melted way”. “I used to feel really guilt about my bad snacking habits. I’d often be rushing about, and I’d grab something high calorie and unsatisfying – often a pack of crisps. I’d be hungry again really soon afterwards so it became a vicious cycle. The results have been remarkable,” she explained. “These days, if I am feeling peckish I’ll go for a banana or a pack of almonds. That’s the food I’m craving. I’m now closer to nine stone than 11 – the pounds just melted away over eight or nine months without me even noticing. The weight loss wasn’t really my goal though – I feel younger and more energetic. Perhaps I’m particularly susceptible to this kind of brain training, but it has been transformative for me.

A study of 83 adults showed that people who played the game online just 4 times in one week lost weight and ate an average of 220 kcal less per day – roughly equivalent to a chocolate-iced doughnut.The academics found in trials that playing the game without distractions for a few minutes a day can train the brain to control impulses to reach for chocolate, cakes, crisps or alcohol. The release of the free app will allow dieters or those who want to cut consumption of junk food or alcohol to try it and in the process generate more anonymous data to help psychologists measure how effective an app version of the brain-training programme can be.

The basis of the app is published research showing that people are more inclined to choose foods or drink high in sugar and fat because they activate the brain’s reward system, stimulating the release of dopamine and endorphins, which can produce feelings of pleasure and make the person want more. Research has found that the more people activate brain areas associated with reward when they see foods, the more they eat and the more weight they gain. Once triggered, these impulses can be hard to control.

Source: http://www.exeter.ac.uk/

How To Eradicate Undetectable HIV Cells

French researchers have identified a marker that makes it possible to differentiate “dormantHIVinfected cells from healthy cells. This discovery will make it possible to isolate and analyze reservoir cells which, by silently hosting the virus, are responsible for its persistence even among patients receiving antiviral treatment, whose viral load is undetectable. It offers new therapeutic strategies for targeting infected cells. This research is part of the ANRS strategic program “Réservoirs du VIH”.

HIV detection

Since 1996, there has been consensus among the scientific community that a cure for HIV will involve targetingreservoir cells” that host the virus in the organisms of patients undergoing triple therapy. HIV can remain hidden in these reservoirs, in latent form, for several decades, eluding the immune system’s response and antiviral treatments, without any viral protein being expressed. But if treatment ceases, the virus massively proliferates and the disease progresses again. Patients must therefore receive treatment for life. To envisage eliminating this dormant virus, a first stage consists in distinguishing the HIV-infected reservoir cells from their healthy counterpart cells, which resemble them to a very large degree. This is what has been achieved by a team of researchers, who have identified a marker of reservoir cells: a protein present only on the surface of infected cells.

Hypothesizing that HIV might leave a mark on the surface of its host cell, researchers from the Institut de génétique humaine (CNRS/Montpellier University) first worked in vitro on an infection model developed in their laboratory. After comparing infected cells and healthy cells, they noticed one particular protein, coded by a gene among the hundred of those expressed in a specific way by infected cells. Present only on the surface of the infected cells, the CD32a protein thus met, in vitro, the criteria of a reservoir cell marker. This was then confirmed by experiments on clinical samples. By studying blood samples from 12 patients living with HIV and receiving treatment, the researchers isolated the cells expressing the marker and observed that almost all were HIV carriers. In vitro, the activation of these cells induced a production of viruses capable of reinfecting healthy cells whereas their elimination entailed a significant delay in viral production.

The findings are the result of a collaboration between the CNRS, Montpellier University, Inserm, the Institut Pasteur, the Henri-Mondor AP-HP hospital in Créteil, the Gui de Chauliac hospital (CHU de Montpellier) and the VRI (Vaccine Research Institute), and is published in the journal Nature on March 15, 2017. A patent owned by the CNRS has been filed for the diagnostic and therapeutic use of the identified marker.

Source: http://presse.inserm.fr/

How To Build A 3D Printed House in One Day For $10,000

San Francisco-based Apis Cor reported on its blog that on a cold day last December it (and a number of its partners) built an entire 400 square foot house with its custom printer and it only cost $10,000. Oh, and it took just 24 hours to complete.

ApisCor_febr_top

Others have claimed to build houses with 3D printers. But what makes Apis Cor’s house unique is that it wasn’t constructed from pre-printed panels that required assembly by construction workers. The “printer” used is a giant, mobile piece of crane-like equipment that layers on cement in one continuous process, building both the internal and external structure all at once instead of in multiple parts. It’s a one-story structure but it can be constructed in just about any shape and the company showed how it could be built in even the coldest of conditions in this YouTube video.

Contractors worrying about their jobs shouldn’t panic…yet. Once all the walls are put together, those workers are then needed to do everything else – like installing windows and the roof, plus painting, insulating and putting in appliances, according to this report in Quartz. A finished test house that the company built with a partner in Russia is “cozy and comfortable” and includes “a hall, a bathroom, a living room and a compact functional kitchen with the most modern appliances from Samsung company,” Apis Cor’s blog boasts.

3D printed house

As you can see with the advent of new technology,” the company says in its blog post. “Construction 3D printing is changing the view and approach to the construction of low-rise buildings and provides new opportunities to implement custom architectural solutions.

The possibilities of this advancement in 3D printing are many. Houses could be quickly constructed for refugee camps, people displaced by natural disaster or for those who do not have available housing, such as the homeless. Governments could build entire communities of affordable housing at just a fraction of what’s paid today.

Source:  https://www.washingtonpost.com/
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http://apis-cor.com/

How To Recycle Carbon Dioxide

An international team of scientists led by Liang-shi Li at Indiana University (IU) has achieved a new milestone in the quest to recycle carbon dioxide in the Earth’s atmosphere into carbon-neutral fuels and others materials.

 

The chemists have engineered a molecule that uses light or electricity to convert the greenhouse gas carbon dioxide into carbon monoxide — a carbon-neutral fuel source — more efficiently than any other method of “carbon reduction.”

molecular leaf

If you can create an efficient enough molecule for this reaction, it will produce energy that is free and storable in the form of fuels,” said Li, associate professor in the IU Bloomington College of Arts and Sciences‘ Department of Chemistry. “This study is a major leap in that direction.”

Burning fuel — such as carbon monoxide — produces carbon dioxide and releases energy. Turning carbon dioxide back into fuel requires at least the same amount of energy. A major goal among scientists has been decreasing the excess energy needed.

This is exactly what Li’s molecule achieves: requiring the least amount of energy reported thus far to drive the formation of carbon monoxide. The molecule — a nanographene-rhenium complex connected via an organic compound known as bipyridine — triggers a highly efficient reaction that converts carbon dioxide to carbon monoxide. The ability to efficiently and exclusively create carbon monoxide is significant due to the molecule’s versatility.

Carbon monoxide is an important raw material in a lot of industrial processes,” Li said. “It’s also a way to store energy as a carbon-neutral fuel since you’re not putting any more carbon back into the atmosphere than you already removed. You’re simply re-releasing the solar power you used to make it.

The secret to the molecule’s efficiency is nanographene — a nanometer-scale piece of graphite, a common form of carbon (i.e. the black “lead” in pencils) — because the material’s dark color absorbs a large amount of sunlight.

Li said that bipyridine-metal complexes have long been studied to reduce carbon dioxide to carbon monoxide with sunlight. But these molecules can use only a tiny sliver of the light in sunlight, primarily in the ultraviolet range, which is invisible to the naked eye. In contrast, the molecule developed at IU takes advantage of the light-absorbing power of nanographene to create a reaction that uses sunlight in the wavelength up to 600 nanometers — a large portion of the visible light spectrum.

Essentially, Li said, the molecule acts as a two-part system: a nanographeneenergy collector” that absorbs energy from sunlight and an atomic rheniumengine” that produces carbon monoxide. The energy collector drives a flow of electrons to the rhenium atom, which repeatedly binds and converts the normally stable carbon dioxide to carbon monoxide.

The idea to link nanographene to the metal arose from Li’s earlier efforts to create a more efficient solar cell with the carbon-based material. “We asked ourselves: Could we cut out the middle man — solar cells — and use the light-absorbing quality of nanographene alone to drive the reaction?” he said.

Next, Li plans to make the molecule more powerful, including making it last longer and survive in a non-liquid form, since solid catalysts are easier to use in the real world.

The process is reported in the Journal of the American Chemical Society.

Source: http://news.indiana.edu/