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Archive for the ‘chemistry’ category: Page 162

Dec 1, 2022

Femtosecond to attosecond light pulses from a molecular modulator

Posted by in category: chemistry

Year 2011 face_with_colon_three


Ultrafast science has begun to tackle the measurement of electronic and chemical processes taking place on the few-femtosecond-to-attosecond timescale. This field requires high-power, extremely short-duration laser pulses. Here we review progress towards the generation of such pulses by Raman scattering in a medium whose component molecules oscillate in phase, which modulates the optical polarizability of the medium and generates high-order Raman sidebands on a field propagating through it. This process may occur with high efficiency and thus lead to sufficient bandwidth for supporting few-femtosecond to attosecond pulses. Significant progress has recently been made in the use of this technique to deliver useable ultrashort pulses in the visible to ultraviolet regions of the spectrum.

Dec 1, 2022

Nanotech strategy shows promise for treating autoimmune disease

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

Scientists at Scripps Research have reported success in initial tests of a new, nanotech-based strategy against autoimmune diseases.

The scientists, who reported their results in ACS Nano, engineered cell-like “” that target only the driving an autoimmune reaction, leaving the rest of the immune system intact and healthy. The nanoparticles greatly delayed, and in some animals even prevented, in a mouse model of arthritis.

“The potential advantage of this approach is that it would enable safe, long-term treatment for where the immune system attacks its own tissues or organs—using a method that won’t cause broad immune suppression, as current treatments do,” says study senior author James Paulson, Ph.D., Cecil H. and Ida M. Green Chair of Chemistry in the Department of Molecular Medicine at Scripps Research.

Dec 1, 2022

Scientists link rare genetic phenomenon to neuron function, schizophrenia

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

In our cells, the language of DNA is written, making each of us unique. A tandem repeat occurs in DNA when a pattern of one or more nucleotides—the basic structural unit of DNA coded in the base of chemicals cytosine ©, adenine (A), guanine (G) and thymine (T)—is repeated multiple times in tandem. An example might be: CAG CAG CAG, in which the pattern CAG is repeated three times.

Now, using state-of-the-art whole-genome sequencing and machine learning techniques, the UNC School of Medicine lab of Jin Szatkiewicz, Ph.D., associate professor of genetics, and colleagues conducted one of the first and the largest investigations of repeats in , elucidating their contribution to the development of this devastating disease.

Published in the journal Molecular Psychiatry, the research shows that individuals with schizophrenia had a significantly higher rate of rare tandem repeats in their genomes—7% more than individuals without schizophrenia. And they observed that the tandem repeats were not randomly located throughout the genome; they were primarily found in genes crucial to brain function and known to be important in schizophrenia, according to previous studies.

Dec 1, 2022

Lab-grown adrenal glands could help treat hormone-related conditions

Posted by in categories: biotech/medical, chemistry

Functional adrenal glands have been grown in the lab by coaxing a type of stem cell to develop in a certain way by constantly tweaking the mix of chemicals they are bathed in.

Nov 30, 2022

20 Times More Intense: New Material Will Help Improve Phone and Television Displays

Posted by in categories: chemistry, computing, mobile phones, physics

Scientists have created, synthesized, and analyzed a new class of fluorophores, which are luminous chemical compounds. These are the new bullet systems based on cyanopyrazine. According to research, the inclusion of cyanogroup compounds in fluorophores considerably boosts the efficiency of organic light-emitting diodes (OLED). This indicates they can be utilized to develop new materials to improve the brightness of smartphone, computer, and television screens. The researchers’ findings were recently published in the journal Dyes and Pigments.

The research was led by Egor Verbitskiy, the director of the Postovsky Institute of Organic Synthesis Ural Branch of RAS and a member of the Laboratory of Medical Chemistry and Advanced Organic Materials at the Ural Federal University. He states that physicists were aware that introducing cyanogroups to fluorophores can enhance the OLEDs’ properties and overall efficiency.

Nov 29, 2022

New Insights into the Chemical Composition of Ayahuasca

Posted by in category: chemistry

Ayahuasca is a psychedelic beverage originally from the Amazon rainforest used in different shamanic settings for medicinal, spiritual, and cultural purposes. It is prepared by boiling in water an admixture of the Amazonian vine Banisteriopsis caapi, which is a source of β-carboline alkaloids, with plants containing N, N-dimethyltryptamine, usually Psychotria viridis. While previous studies have focused on the detection and quantification of the alkaloids present in the drink, less attention has been given to other nonalkaloid components or the composition of the solids suspended in the beverage, which may also affect its psychoactive properties. In this study, we used nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) to study the composition of ayahuasca samples, to determine their alkaloid qualitative and quantitative profiles, as well as other major soluble and nonsoluble components. For the first time, fructose was detected as a major component of the samples, while harmine (a β-carboline previously described as an abundant alkaloid in ayahuasca) was found to be present in the solids suspended in the beverage. In addition, N, N-dimethyltryptamine (DMT), harmine, tetrahydroharmine, harmaline, and harmol were identified as the major alkaloids present in extracts of all samples. Finally, a novel, easy, and fast method using quantitative NMR was developed and validated to simultaneously quantify the content of these alkaloids found in each ayahuasca sample.

Ayahuasca, commonly translated from the Quechua language as “vine of the spirits” or “vine of the dead”, is a psychedelic beverage originally from the Amazon rainforest used in different shamanic settings for a variety of medicinal, spiritual, and cultural purposes.1 It is prepared by boiling in water an admixture of the vine Banisteriopsis caapi, which is a source of β-carboline alkaloids, and other plants containing N, N-dimethyltryptamine (DMT), usually Psychotria viridis ( Figure Figure1 1 ) or Diplopterys cabrerana, (where the preparation name is usually referred to as yagé).2.

Nov 29, 2022

Seemingly Impossible: Nanostructure Compresses Light 10,000 Times Thinner Than a Human Hair

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

Until recently, physicists widely believed that it was impossible to compress light below the so-called diffraction limit, except when utilizing metal nanoparticles, which also absorb light. As a result, it seemed to be impossible to compress light strongly in dielectric materials like silicon, which are essential for information technologies and had the significant advantage of not absorbing light. Interestingly, it was theoretically shown that the diffraction limit does not apply to dielectrics back in 2006. However, no one has been able to demonstrate this in the actual world due to the fact that it requires such complex nanotechnology that no one has yet been able to create the required dielectric nanostructures.

A research team from the Technical University of Denmark has created a device known as a “dielectric nanocavity” that successfully concentrates light in a volume 12 times smaller than the diffraction limit. The finding is groundbreaking in optical research and was recently published in the journal Nature Communications.

Nature Communications is a peer-reviewed, open access, multidisciplinary, scientific journal published by Nature Research. It covers the natural sciences, including physics, biology, chemistry, medicine, and earth sciences. It began publishing in 2010 and has editorial offices in London, Berlin, New York City, and Shanghai.

Nov 29, 2022

Four-million-mile battery is now a reality

Posted by in categories: chemistry, sustainability, transportation

Dahn, a world-renowned battery scientist and NSERC/Tesla Canada Chair, presented the exciting news during his keynote presentation (titled: More than a million miles and a century of life) at the international battery seminar (IBS) held 28–31 March 2022 in Orlando, Florida.

The term “Million Mile” battery first came to life after Dahn’s 2019 open access publication in Journal of The Electrochemical Society (JES) stating “we conclude that cells of this type should be able to power an electric vehicle for over 1.6 million kilometers (1 million miles) and last at least two decades in grid storage”.

Nov 29, 2022

A crystal shape conundrum is finally solved

Posted by in categories: chemistry, materials

A crystal’s shape is determined by its inherent chemistry, a characteristic that ultimately determines its final form from the most basic of details. But sometimes the lack of symmetry in a crystal makes the surface energies of its facets unknowable, confounding any theoretical prediction of its shape.

Theorists at Rice University say they’ve found a way around this conundrum by assigning arbitrary latent energies to its surfaces or, in the case of two-dimensional materials, its edges.

Yes, it seems like cheating, but in the same way a magician finds a select card in a deck by narrowing the possibilities, a little algebraic sleight-of-hand goes a long way to solve the problem of predicting a crystal’s shape.

Nov 28, 2022

Highly integrated watch for noninvasive continual glucose monitoring

Posted by in categories: biotech/medical, chemistry, mobile phones

This article reports a highly integrated watch for noninvasive continual blood glucose monitoring. The watch employs a Nafion-coated flexible electrochemical sensor patch fixed on the watchband to obtain interstitial fluid (ISF) transdermally at the wrist. This reverse iontophoresis-based extraction method eliminates the pain and inconvenience that traditional fingerstick blood tests pose in diabetic patients’ lives, making continual blood glucose monitoring practical and easy. All electronic modules, including a rechargeable power source and other modules for signal processing and wireless transmission, are integrated onto a watch face-sized printed circuit board (PCB), enabling comfortable wearing of this continual glucose monitor. Real-time blood glucose levels are displayed on the LED screen of the watch and can also be checked with the smartphone user interface.