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Metallic NanoParticles 50 Times More Effective As Catalysts

Scientists at Tokyo Institute of Technology produced subnano-sized metallic particles that are very effective as catalysts for the oxidation of hydrocarbons. These catalysts can be as much as 50 times more effective than well-known Au-Pd bimetallic nanocatalysts.
The oxidation of aromatic hydrocarbons is critically important for producing a great variety of useful organic compounds that are used throughout all types of industries. These oxidation processes require the use of catalysts and solvents, which are usually environmentally hazardous. Thus, finding a solvent-free oxidation process using nanosized catalytic particles has attracted considerable attention. Interestingly, sub-nanoscale catalytic particles (subnanocatalysts, or SNCs) composed of noble metals are even better at their job because their increased surface area and unique electronic state results in favorable effects for oxidizing hydrocarbons and also prevents them from getting oxidized themselves. This makes them cost-effective because the amount of metal required for SNCs is lower than for nano-sized catalysts.

A team including Dr. Miftakhul Huda, Keigo Minamisawa, Dr. Takamasa Tsukamoto, and Dr. Makoto Tanabe at Tokyo Institute of Technology (Tokyo Tech), led by Prof. Kimihisa Yamamoto, created multiple types of SNCs by using dendrimers, which are tree-like spherical molecules that can be used as a template to contain the desired catalysts. “Dendrimer is expected to provide internal nanospaces that could be suitable for catalytic conversion in the presence of metal particles,” explains Yamamoto . The scientists created various catalysts of different sizes, depending on the noble metal used and the number of atoms of each catalytic particle.

Each dendrimer molecule hosts a subnano-sized metallic particle that allows for the oxidation of aromatic hydrocarbons, such as toluene (left), to produce useful organic compounds, such as benzoic acid (right). Oxygen molecules are represented in red.

They compared their performance to find the best noble metal for making SNCs and then tried to determine the mechanism behind their high catalytic activity. Smaller SNCs were found to be better, while less oxophilic metals (such as platinum) were superior. The team postulated that the surface of platinum SNCs does not oxidize easily, which makes them reusable and results in the highest catalytic performance of the Pt19 SNC that can be as high as 50 times more effective than the common Au-Pd nanocatalysts. The team will continue working to shed light on these catalytic phenomena. “The development of a more detailed mechanism including theoretical considerations is currently in progress,” says Tanabe. The applications of such catalysts could greatly contribute for reducing pollution and enhancing our effective use of Earth’s metal resources.

Source: https://www.titech.ac.jp/

How To Replace The Thick Glass Lenses by 2D Metalens

In optics, the era of glass lenses may be waning. In recent years, physicists and engineers have been designing, constructing and testing different types of ultrathin materials that could replace the thick glass lenses used today in cameras and imaging systems. Critically, these engineered lenses — known as metalenses — are not made of glass. Instead, they consist of materials constructed at the nanoscale into arrays of columns or fin-like structures. These formations can interact with incoming light, directing it toward a single focal point for imaging purposes.

But even though metalenses are much thinner than glass lenses, they still rely on “high aspect ratio” structures, in which the column or fin-like structures are much taller than they are wide, making them prone to collapsing and falling over. Furthermore, these structures have always been near the wavelength of light they’re interacting with in thickness — until now. In a paper published in the journal Nano Letters, a team from the University of Washington (UW) and the National Tsing Hua University in Taiwan announced that it has constructed functional metalenses that are one-tenth to one-half the thickness of the wavelengths of light that they focus. Their metalenses, which were constructed out of layered 2D materials, were as thin as 190 nanometers — less than 1/100,000ths of an inch thick.

This is the first time that someone has shown that it is possible to create a metalens out of 2D materials,” said senior and co-corresponding author Arka Majumdar, a UW assistant professor of physics and of electrical and computer engineering.

Their design principles can be used for the creation of metalenses with more complex, tunable features, added Majumdar, who is also a faculty researcher with the UW’s Molecular Engineering & Sciences Institute and Institute for Nano-Engineered Systems.

Source: https://www.washington.edu/

Gene-editing Tools Will Alter Foods Precisely And Cheaply

The next generation of biotech food is headed for the grocery aisles, and first up may be salad dressings or granola bars made with soybean oil genetically tweaked to be good for your heart. By early next year, the first foods from plants or animals that had their DNAedited” are expected to begin selling. It’s a different technology than today’s controversial “genetically modifiedfoods, more like faster breeding that promises to boost nutrition, spur crop growth, and make farm animals hardier and fruits and vegetables last longer.

The U.S. National Academy of Sciences has declared gene editing one of the breakthroughs needed to improve food production so the world can feed billions more people amid a changing climate. Yet governments are wrestling with how to regulate this powerful new tool. And after years of confusion and rancor, will shoppers accept gene-edited foods or view them as GMOs in disguise?

GMOs, or genetically modified organisms, are plants or animals that were mixed with another species’ DNA to introduce a specific trait — meaning they’re “transgenic.” Best known are corn and soybeans mixed with bacterial genes for built-in resistance to pests or weed killers.

If the consumer sees the benefit, I think they’ll embrace the products and worry less about the technology,” said Dan Voytas, a University of Minnesota professor and chief science officer for Calyxt Inc., which edited soybeans to make the oil heart-healthy.

Researchers are pursuing more ambitious changes: Wheat with triple the usual fiber, or that’s low in gluten. Mushrooms that don’t brown, and better-producing tomatoes. Drought-tolerant corn, and rice that no longer absorbs soil pollution as it grows. Dairy cows that don’t need to undergo painful de-horning, and pigs immune to a dangerous virus that can sweep through herds.

Scientists even hope gene editing eventually could save species from being wiped out by devastating diseases like citrus greening, a so far unstoppable infection that’s destroying Florida’s famed oranges. First they must find genes that could make a new generation of trees immune.

If we can go in and edit the gene, change the DNA sequence ever so slightly by one or two letters, potentially we’d have a way to defeat this disease,” said Fred Gmitter, a geneticist at the University of Florida Citrus Research and Education Center, as he examined diseased trees in a grove near Fort Meade.

Source: https://whyy.org/

Double Layers Of Graphene Conduct Current Without Resistance

Scientists at the Helmholtz Zentrum Berlin (HZB) have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance. They probed the bandstructure at BESSY II with extremely high resolution ARPES and could identify a flat area at a surprising location.

Carbon atoms have diverse possibilities to form bonds. Pure carbon can therefore occur in many forms, as diamond, graphite, as nanotubes, football molecules or as a honeycomb-net with hexagonal meshes, graphene. This exotic, strictly two-dimensional material conducts electricity excellently, but is not a superconductor. But perhaps this can be changed.

In April 2018, a group at MIT, USA, showed that it is possible to generate a form of superconductivity in a system of two layers of graphene under very specific conditions: To do this, the two hexagonal nets must be twisted against each other by exactly the magic angle of 1.1°. Under this condition a flat band forms in the electronic structure. The preparation of samples from two layers of graphene with such an exactly adjusted twist is complex, and not suitable for mass production. Nevertheless, the study has attracted a lot of attention among experts.

But there is one more, much simpler way of flat band formation. This was shown by a group at the HZB around Prof. Oliver Rader and Dr. Andrei Varykhalov with investigations at BESSY II. The samples were provided by Prof. Thomas Seyller, TU Chemnitz. There they are produced using a process that is also suitable for the production of larger areas and in large quantities: A silicon carbide crystal is heated until silicon atoms evaporate from the surface, leaving first a single-layer of graphene on the surface, and then a second layer of graphene. The two graphene layers are not twisted against each other, but lie exactly on top of each other.

This flat area is a prerequisite for superconductivity but only if it is situated exactly at the so-called Fermi energy. In the case of the two-layer graphene, its energy level is only 200 milli-electron volts below the Fermi energy, but it is possible to raise the energy level of the flat area to the Fermi energy either by doping with foreign atoms or by applying an external voltage, the so-called gate voltage.

The findings have been Published in Science Advances.

Source: https://www.helmholtz-berlin.de/

AI Robot Presents TV News In China

China’s state news agency Xinhua this week introduced the newest members of its newsroom: AI anchors who will reporttirelessly” all day every day, from anywhere in the country. Chinese viewers were greeted with a digital version of a regular Xinhua news anchor named Qiu Hao. The anchor, wearing a red tie and pin-striped suit, nods his head in emphasis, blinking and raising his eyebrows slightly.

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Not only can I accompany you 24 hours a day, 365 days a year. I can be endlessly copied and present at different scenes to bring you the news,” he says. Xinhua also presented an English-speaking AI, based on another presenter, who adds: “The development of the media industry calls for continuous innovation and deep integration with the international advanced technologies … I look forward to bringing you brand new news experiences.”

Developed by Xinhua and the Chinese search engine, Sogou, the anchors were developed through machine learning to simulate the voice, facial movements, and gestures of real-life broadcasters, to present a “a lifelike image instead of a cold robot,” according to Xinhua.

Source: https://www.theguardian.com/

Spy Drone Stays Airborne For One Entire Year

A solar-powered spy drone that can fly for a year without maintenance or fuel could one day carry out missions for the military. The Unmanned Aerial Vehicle (UAV) uses the sun to power its engines during the day as well as recharge its batteries for overnight operation. Known as Phasa-35, the aircraft could one day be used for surveillance and provide vital communications to remote areas at altitudes of up to 70,000ft (21,000m). Work is already underway to prepare the first drone for flight tests in 2019, according to British defence giant BAE Systems, which is developing the aircraft.

Engineers from BAE and Farnborough-based firm Prismatic announced they would collaborate on the development of the UAV.

 ‘Phasa-35 has the ability to revolutionise the way we think about Beyond Line of Sight communications. ‘It’s great to have the support of a world leading technology company like BAE Systems. said Paul Brooks, founder and managing director of Prismatic.

 So-called ‘High Altitude Low Energy‘ (HALE) aircraft offer a cheaper alternative to conventional satellite technology, according to BAEPhasa-35 (Persistent High Altitude Solar Aircraft) uses long-life battery technology and ultra-lightweight solar cells to potentially maintain flight for up to 12 months. According to Prismatic, the UAV has a range of potential applications, including defence, security, surveillance and even environmental science imagery.

Source: https://www.baesystems.com/
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https://www.reuters.com/

How To Heal Acute Kidney Injury

Each year, there are some 13.3 million new cases of acute kidney injury (AKI), a serious affliction. Formerly known as acute renal failure, the ailment produces a rapid buildup of nitrogenous wastes and decreases urine output, usually within hours or days of disease onset.  Severe complications often ensue. Currently, there is no known cure for AKI.

AKI is responsible for 1.7 million deaths annually. Protecting healthy kidneys from harm and treating those already injured remains a significant challenge for modern medicine.

In new research appearing in the journal Nature Biomedical Engineering, Hao Yan and his colleagues at the University of Wisconsin-Madison and in China describe a new method for treating and preventing AKI. Their technique involves the use of tiny, self-assembling forms measuring just billionths of a meter in diameter.

Yan directs the Biodesign Center for Molecular Design and Biomimetics and is Professor in the School of Molecular Sciences at the Arizona State University (ASU).

Their research demonstrated that the introduction of DNA origami nanostructures (DONs) protected normal kidneys and improved functioning of kidneys damaged by AKI. The beneficial effect of the nanostructures was comparable to the current treatment modality, administration of an anti-oxidant drug known as N-acetylcysteine (NAC). New treatments are being saught because NAC is not easily absorbed in the kidneys. Further examination of stained tissue samples from mice confirmed the beneficial effects of the DONs.

Source: https://biodesign.asu.edu/

Immunotherapy Technique Specifically Targets Tumor Cells

A new immunotherapy screening prototype developed by University of California, Irvine (UCI) researchers can quickly create individualized cancer treatments that will allow physicians to effectively target tumors without the side effects of standard cancer drugsUCI’s Weian Zhao and Nobel laureate David Baltimore with Caltech led the research team that developed a tracking and screening system that identifies T cell receptors with 100-percent specificity for individual tumors within just a few days.

In the human immune system, T cells have molecules on their surfaces that bind to antigens on the surface of foreign or cancer cells. To treat a tumor with T cell therapy, researchers must identify exactly which receptor molecules work against a specific tumor’s antigens. UCI researchers have sped up that identification process.

This technology is particularly exciting because it dismantles major challenges in cancer treatments,” said Zhao, an associate professor of pharmaceutical sciences. “This use of droplet microfluidics screening significantly reduces the cost of making new cancer immunotherapies that are associated with less systemic side effects than standard chemotherapy drugs, and vastly speeds up the timeframe for treatment.

Zhao added that traditional cancer treatments have offered a one-size-fits-all disease response, such as chemotherapy drugs which can involve systemic and serious side effects.

Research findings appear in Lab on a Chip.

Source: https://news.uci.edu/

Ultrathin, Ultralight NanoCardboard For Aerospace

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure. Now, a team of Penn Engineers has demonstrated a new material they call “nanocardboard,” an ultrathin equivalent of corrugated paper cardboard. A square centimeter of nanocardboard weighs less than a thousandth of a gram and can spring back into shape after being bent in half.

Nanocardboard is made out of an aluminum oxide film with a thickness of tens of nanometers, forming a hollow plate with a height of tens of microns. Its , similar to that of corrugated cardboard, makes it more than ten thousand times as stiff as a solid plate of the same mass.

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Nanocardboard is made out of an aluminum oxide film with a thickness of tens of nanometers, forming a hollow plate with a height of tens of microns. Its sandwich structure, similar to that of corrugated cardboard, makes it more than ten thousand times as stiff as a solid plate of the same mass. A square centimeter of nanocardboard weighs less than a thousandth of a gram and can spring back into shape after being bent in half.

Nanocardboard‘s stiffness-to-weight ratio makes it ideal for aerospace and microrobotic applications, where every gram counts. In addition to unprecedented mechanical properties, nanocardboard is a supreme thermal insulator, as it mostly consists of empty space. Future work will explore an intriguing phenomenon that results from a combination of properties: shining a light on a piece of nanocardboard allows it to levitate. Heat from the light creates a difference in temperatures between the two sides of the plate, which pushes a current of air molecules out through the bottom.

Igor Bargatin, Assistant Professor of Mechanical Engineering, along with lab members Chen Lin and Samuel Nicaise, led the study.

They published their results in the journal Nature Communications.

Source: https://phys.org/

Stem Cell Therapy Could Treat Alzheimer’s And Parkinson’s

Rutgers scientists have created a tiny, biodegradable scaffold to transplant stem cells and deliver drugs, which may help treat Alzheimer’s and Parkinson’s diseases, aging brain degeneration, spinal cord injuries and traumatic brain injuriesStem cell transplantation, which shows promise as a treatment for central nervous system diseases, has been hampered by low cell survival rates, incomplete differentiation of cells and limited growth of neural connections.

So, Rutgers scientists designed bio-scaffolds that mimic natural tissue and got good results in test tubes and mice. These nano-size scaffolds hold promise for advanced stem cell transplantation and neural tissue engineering. Stem cell therapy leads to stem cells becoming neurons and can restore neural circuits.

It’s been a major challenge to develop a reliable therapeutic method for treating central nervous system diseases and injuries,” said study senior author KiBum Lee, a professor in the Department of Chemistry and Chemical Biology at Rutgers University-New Brunswick. “Our enhanced stem cell transplantation approach is an innovative potential solution.

The researchers, in cooperation with neuroscientists and clinicians, plan to test the nano-scaffolds in larger animals and eventually move to clinical trials for treating spinal cord injury. The scaffold-based technology also shows promise for regenerative medicine.

The study included researchers from Rutgers and Kyung Hee University in South Korea. The results have been published in  Nature Communications.

Source: https://www.eurekalert.org/