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Archive for the ‘chemistry’ category: Page 250

Jan 25, 2021

Physicists succeed in filming phase transition with extremely high spatial and temporal resolution

Posted by in categories: chemistry, nanotechnology, particle physics

Laser beams can be used to change the properties of materials in an extremely precise way. This principle is already widely used in technologies such as rewritable DVDs. However, the underlying processes generally take place at such unimaginably fast speeds and at such a small scale that they have so far eluded direct observation. Researchers at the University of Göttingen and the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen have now managed to film, for the first time, the laser transformation of a crystal structure with nanometre resolution and in slow motion in an electron microscope. The results have been published in the journal Science.

The team, which includes Thomas Danz and Professor Claus Ropers, took advantage of an unusual property of a material made up of atomically thin layers of sulfur and tantalum atoms. At , its is distorted into tiny wavelike structures—a “charge-density wave” is formed. At higher temperatures, a phase transition occurs in which the original microscopic waves suddenly disappear. The electrical conductivity also changes drastically, an interesting effect for nano-electronics.

In their experiments, the researchers induced this phase transition with short laser pulses and recorded a film of the charge-density wave reaction. “What we observe is the rapid formation and growth of tiny regions where the material was switched to the next phase,” explains first author Thomas Danz from Göttingen University. “The ultrafast transmission developed in Göttingen offers the highest time resolution for such imaging in the world today.” The special feature of the experiment lies in a newly developed imaging technique, which is particularly sensitive to the specific changes observed in this phase transition. The Göttingen physicists use it to take images that are composed exclusively of electrons that have been scattered by the crystal’s waviness.

Jan 25, 2021

Scientists use a novel ink to 3D print bone with living cells

Posted by in categories: 3D printing, bioprinting, biotech/medical, chemistry

Scientists from UNSW Sydney have developed a ceramic-based ink that may allow surgeons in the future to 3D-print bone parts complete with living cells that could be used to repair damaged bone tissue.

Using a 3D-printer that deploys a special ink made up of calcium phosphate, the scientists developed a new technique, known as ceramic omnidirectional bioprinting in cell-suspensions (COBICS), enabling them to print -like structures that harden in a matter of minutes when placed in water.

While the idea of 3D-printing bone-mimicking structures is not new, this is the first time such material can be created at room temperature—complete with living cells—and without harsh chemicals or radiation, says Dr. Iman Roohani from UNSW’s School of Chemistry.

Jan 24, 2021

The Empowering Neurologist — David Perlmutter M.D., and Dr. David Sinclair

Posted by in categories: biotech/medical, chemistry, genetics, law, life extension, security

Fair to say that we all assume that aging is inevitable. In reality however, there is no biological law that says we must age. Over the years we’ve seen a variety of theories proposed to explain why we age including the accumulation of damage to our DNA, the damaging effects of chemicals called “free radicals, changes in the function of our mitochondria, and so many others.

Our guest today, Dr. David Sinclair, believes that aging is related to a breakdown of information. Specifically, he describes how, with time, our epigenome accumulates changes that have powerful downstream effects on the way our DNA functions. Reducing these changes to the epigenome is achievable and in fact, even taking it further, his research now reveals that the epigenome can be reprogrammed back to a youthful state.

Continue reading “The Empowering Neurologist — David Perlmutter M.D., and Dr. David Sinclair” »

Jan 23, 2021

You Can Actually See the Milky Way’s Wave When You Map Its Stars

Posted by in categories: chemistry, evolution, space

Spiral galaxies are one of the most commonly known types of galaxy. Most people think of them as large round disks, and know that our Milky Way is counted among their number. What most people don’t realize is that many spiral galaxies have a type of warping effect that, when you look at them edge on, can make it seem like they are forming a wave. Now scientists, led by Xinlun Chen at the University of Virginia, have studied millions of stars in the Milky Way and begun to develop a picture of a “wave” passing through our own galaxy.

Since humans are not currently able to view the Milky Way in an edge-on orientation, they must resort to more brute force methods to develop models about the what, if any, wave our galaxy has. Luckily, scientists now have the tools to do so, in the form of the Sloan Digital Sky Survey and ESA’s Gaia satellite.

The method the team used was to try to identify and track the motions of as many stars as possible. To do this, they used the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, which is part of the SDSS. This preliminary data allowed them to look at both the chemical compositions as well as the motions of hundreds of thousands of stars. While this motion data was helpful in starting to form the picture of the Milky Way’s wave, it was not sufficient to complete it.

Jan 23, 2021

How Explainable Artificial Intelligence Can Help Humans Innovate

Posted by in categories: biological, chemistry, information science, particle physics, robotics/AI, transportation

I like this idea. I don’t want AI to be a black box, I want to know what’s happening and how its doing it.


The field of artificial intelligence has created computers that can drive cars, synthesize chemical compounds, fold proteins, and detect high-energy particles at a superhuman level.

However, these AI algorithms cannot explain the thought processes behind their decisions. A computer that masters protein folding and also tells researchers more about the rules of biology is much more useful than a computer that folds proteins without explanation.

Continue reading “How Explainable Artificial Intelligence Can Help Humans Innovate” »

Jan 21, 2021

Lasers turn pure aluminum … ‘gold’

Posted by in categories: chemistry, physics

The ultimate goal of the Old World alchemist was to turn inexpensive metals into gold. Modern-day physicists at the University of Rochester’s Institute of Optics (Rochester, NY), have turned aluminum and other metals gold—in color if not chemistry. A femtosecond laser processing technique created by professor Chunlei Guo and his assistant Anatoliy Vorobeyv alters the surface properties of aluminum, platinum, titanium, tungsten, silver, and gold to create tints of gold, blue, gray, black, and even multicolored irridescence.

Jan 21, 2021

Israeli-made mask eliminates over 99% of coronavirus, lab tests suggest

Posted by in categories: biotech/medical, chemistry, nanotechnology, transportation

The SonoMask displayed an ability to neutralize the novel coronavirus at an effectiveness of 99.34% within trials performed by the ATCCR Testing laboratory in China, Ramat Gan-based Israeli fabric maker and developer Sonovia announced on Saturday. Sonovia’s reusable anti-viral masks are coated in zinc oxide nanoparticles that destroy bacteria, fungi and viruses, which it says can help stop the spread of the coronavirus. Results from the most recent round of testing showed that the mask has the ability to neutralize fallen traces of SARS-COV-2 within 30 minutes after making contact with the fabric. The SonoMask was also proven to maintain its protective properties throughout 55 wash cycles.” Following this outstanding result – the product of several months of dedicated anti-viral sonochemistry formulation – we can now assure the public that our SonoMask is working continuously, permanently and rapidly to neutralize the spread of COVID-19,” said Sonovia CEO Joshua Hershcovici. “We are proud of our latest accomplishment that will help people feel safe and protect their loved ones, all the while remaining the most ecologically sound option upon the PPE market.” Sonovia also participated in trials with Adler Plastic in Italy earlier this year, working toward creating a solution for carpets and other types of fabrics. The company boasted a 99.999% efficiency rate against bacteria during the pilot testing round. Furthermore, the Israeli fabric maker has attracted the cooperation of top brands such as Gucci, Chanel and Adidas, working on the Fashion for Good Plug and Play accelerator project – and earning a $250000 investment for their innovation.” We see our breakthrough technology transforming our everyday life, implemented in all textiles surrounding us: from the clothes we wear, to the textiles in our home, the textiles in our public spaces, in public transportation and of course as a protective measure in the workplaces & medical institutes – in a manner that ensures safer surroundings during these unusual times,” said Sonovia’s Chief Technology Officer Liat Goldhammer.

Jan 20, 2021

Multidimensional coherent spectroscopy reveals triplet state coherences in cesium lead-halide perovskite nanocrystals

Posted by in categories: chemistry, nanotechnology, physics, solar power, sustainability

Advanced optoelectronics require materials with newly engineered characteristics. Examples include a class of materials named metal-halide perovskites that have tremendous significance to form perovskite solar cells with photovoltaic efficiencies. Recent advances have also applied perovskite nanocrystals in light-emitting devices. The unusually efficient light emission of cesium lead-halide perovskite may be due to a unique excitonic fine structure made of three bright triplet states that minimally interact with a proximal dark singlet state. Excitons are electronic excitations responsible for the emissive properties of nanostructured semiconductors, where the lowest-energy excitonic state is expected to be long lived and hence poorly emitting (or ‘dark’).

In a new report now published in Science Advances, Albert Liu and a team of scientists in physics and chemistry at the University of Michigan, U.S., and Campinas State University, Brazil, used multidimensional coherent spectroscopy at cryogenic (ultra-cold) temperatures to study the fine structure without isolating the cube-shaped single . The work revealed coherences (wave properties relative to space and time) involving the triplet states of a cesium lead-iodide (CsPbI3) nanocrystal ensemble. Based on the measurements of triplet and inter-triplet coherences, the team obtained a unique exciton fine structure level ordering composed of a dark state, energetically positioned within the bright triplet manifold.

Jan 20, 2021

Red yeast from deep-sea sediment shows anticancer and antibacterial properties

Posted by in categories: biotech/medical, chemistry, genetics

Numerous natural products are awaiting discovery in all kinds of natural habitats. Especially microorganisms such as bacteria or fungi are able to produce diverse natural products with high biomedical application potential in particular as antibiotics and anticancer agents. This includes the so-called red yeast of the species Rhodotorula mucilaginosa, isolated from a deep-sea sediment sample from the Mid-Atlantic Ridge and analyzed for its genome and chemical constituents by researchers from GEOMAR Centre for Marine Biotechnology (GEOMAR-Biotech) of GEOMAR Helmholtz Centre for Ocean Research Kiel and Kiel University (CAU). In a joint effort, the scientists succeeded in demonstrating its anticancer and antibacterial effects. This study, partly-funded by Kiel Marine Science (KMS) of Kiel University, was recently published in the renowned scientific journal Marine Drugs.

A unique opportunity arose for researchers in the Department of Botanical Genetics and Molecular Biology at Kiel University, headed by Professor Frank Kempken. Via the Institute of Geosciences at Kiel University, his group had access to sediment samples from the Mid-Atlantic Ridge in 1600—4000 m depth collected during a research cruise with the German research vessel MARIA S. MERIAN. From one of these sediment cores taken at a depth of 3600 m, Prof. Kempken´s group succeeded in isolating and cultivating living fungi of the species Rhodotorula mucilaginosa. This slowly growing type of yeast, which belongs to the so-called Basidiomycete yeasts should not be confused with the well-known baker’s yeast. The species originally grows at great depth tolerating high hydrostatic pressure and rather cold temperatures.

“With the applied methodology we have succeeded in cultivating yeast colonies that can withstand and grow at room temperatures and under atmospheric pressure. These experiments have shown once more that microorganisms with specific physiological properties thrive in distinct ecological niches. The experiments have shown us further that special ecological niches can produce microorganisms with special characteristics. The assumption about the adaptability of this special genus has therefore encouraged us to further analyze this species,” says Kempken, whose research group has been analyzing genomes of marine fungi for more than ten years.

Jan 19, 2021

Rethinking spin chemistry from a quantum perspective

Posted by in categories: biotech/medical, chemistry, computing, information science, quantum physics

Researchers at Osaka City University use quantum superposition states and Bayesian inference to create a quantum algorithm, easily executable on quantum computers, that accurately and directly calculates energy differences between the electronic ground and excited spin states of molecular systems in polynomial time.

Understanding how the natural world works enables us to mimic it for the benefit of humankind. Think of how much we rely on batteries. At the core is understanding molecular structures and the behavior of electrons within them. Calculating the energy differences between a molecule’s electronic ground and excited spin states helps us understand how to better use that molecule in a variety of chemical, biomedical and industrial applications. We have made much progress in molecules with closed-shell systems, in which electrons are paired up and stable. Open-shell systems, on the other hand, are less stable and their underlying electronic behavior is complex, and thus more difficult to understand. They have unpaired electrons in their ground state, which cause their energy to vary due to the intrinsic nature of electron spins, and makes measurements difficult, especially as the molecules increase in size and complexity.