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Archive for the ‘chemistry’ category: Page 80

Oct 4, 2023

The Nobel Prize in Chemistry 2023

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

Moungi G. Bawendi, Louis E. Brus and Alexei I. Ekimov are awarded the Nobel Prize in Chemistry 2023 for the discovery and development of quantum dots. These tiny particles have unique properties and now spread their light from television screens and LED lamps. They catalyse chemical reactions and their clear light can illuminate tumour tissue for a surgeon.

“Toto, I’ve a feeling we’re not in Kansas anymore,” is a classic quote from the film The Wizard of Oz. Twelve-year-old Dorothy faints onto her bed when her house is swept away by a powerful tornado, but when the house lands again and she steps outside the door, her dog Toto in her arms, everything has changed. Suddenly she is in a magical, technicolour world.

If an enchanted tornado were to sweep into our lives and shrink everything to nano dimensions, we would almost certainly be as astonished as Dorothy in the land of Oz. Our surroundings would be dazzlingly colourful and everything would change. Our gold earrings would suddenly glimmer in blue, while the gold ring on our finger would shine a ruby red. If we tried to fry something on the gas hob, the frying pan might melt. And our white walls – whose paint contains titanium dioxide – would start generating lots of reactive oxygen species.

Oct 4, 2023

Using Nanoparticles to Treat Cancer

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

PhD candidate at UniSA’s Applied Chemistry and Translational Biomaterials (ACTB) Group, Cintya Dharmayanti, has taken out UniSA’s 2021 Three Minute Thesis (3MT) with a condensed presentation of her research about developing nanoparticles for cancer treatment, potentially leading to more effective treatments and reduced side effects. She will be competing in the 2023 FameLab National Finals with a presentation titled, “Behind enemy lines: Tiny assassins in the war against cancer.

For more from University of South Australia visit: https://www.unisa.edu.au/connect/alumni-network/alumni-news/…Track=true.

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Oct 4, 2023

A special molecule that violates the laws of physics could lead to limitless energy

Posted by in categories: chemistry, energy, physics

Scientists may have made a major breakthrough in the quest to produce limitless energy. According to a new study published in the journal American Chemical Society, scientists are looking deeper at a molecule known as azulene, which is a blue-light emitting molecule that seems to flout the fundamental rules of photochemistry.

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Oct 3, 2023

Dr. Alex Colville, Ph.D. — Co-Founder and General Partner — age1

Posted by in categories: bioengineering, biotech/medical, chemistry, finance, genetics, life extension

Venture Investing To Catalyze The Next Generation Of Founder-Led, Longevity Biotech Companies — Dr. Alex Colville, Ph.D., Co-Founder and General Partner — age1.


Dr. Alex Colville, Ph.D. is Co-Founder and General Partner of age1 (https://age1.com/), a venture capital firm focused on catalyzing the next generation of founder-led, longevity biotech companies, with a strategy of building a community of visionaries advancing new therapeutics, tools, and technologies targeting aging and age-related diseases.

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Oct 3, 2023

Physicists who built ultrafast ‘attosecond’ lasers win Nobel Prize

Posted by in categories: biological, chemistry, particle physics, quantum physics

This year’s Nobel Prize in Physics has been awarded to three physicists — Pierre Agostini at Ohio State University, US, Ferenc Krausz at the Max Planck Institute of Quantum Optics in Garching, Germany, and Anne L’Huillier at Lund University, Sweden — for their research into attosecond pulses of light.

Attosecond physics allows scientists to look at the very smallest particles at the very shortest timescales (an attosecond is one-quintillionth of a second, or one-billionth of a nanosecond). The winners all developed experiments to be able to produce these ultrafast laser pulses, which can be used to probe our world at the smallest scales and have applications across chemistry, biology and physics.

The prize was announced this morning by the Royal Swedish Academy of Sciences, in Stockholm, Sweden. The winners share a prize of 11 million Swedish kroner (US$1 million).

Oct 3, 2023

Functional photoacoustic imaging: from nano- and micro- to macro-scale

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

In the biomedical field, optical characterization of cells and tissues is a valuable tool for understanding physiological mechanisms. Current biomedical optical imaging techniques include fluorescence imaging [1], confocal microscopy [2], optical coherence tomography [3], two-photon microscopy [4], near-infrared spectroscopy [5], and diffuse optical tomography [6]. These techniques have significantly advanced biomedical technology and are widely used for both preclinical and clinical purposes. However, the strong optical scattering within turbid biological tissues fundamentally limits the imaging depth of these pure optical imaging techniques to no deeper than the optical ballistic depth ( 1 mm). Thus, their observation depth is superficial and other imaging modalities are needed to explore deeper layers of biological tissue [7].

Photoacoustic imaging (PAI), a promising biomedical technique, achieves superior imaging depths by forming images from optically-derived acoustic signals, which inherently attenuate less than optical signals in biological tissue [8, 9, 10]. PAI is based on the photoacoustic (PA) effect, in which energy is converted from light to acoustic waves via thermoelastic expansion [11,12,13,14,15,16]. To generate PA waves, a laser beam with a typical pulse width of a few nanoseconds illuminates the target tissue. The optical chromophores in biological tissue absorb the light energy and then release the energy soon after. The energy release can can occur as either light energy with a slightly shifted wavelength or as thermal energy that causes thermoelastic expansion. In PAI, the rapidly alternating thermoelastic expansion and contraction caused by pulsed light illumination generates vibrations in tissue that propagate as acoustic waves called PA waves. The generated PA waves can be detected by conventional ultrasound (US) transducers for image generation. Because PAI and ultrasound imaging (USI) share the same signal reception and image reconstruction principle, the two modalities are technically fully compatible and can be implemented in a single US imaging platform accompanied with pulse laser source [17,18,19,20,21]. Since PAI can capture the photochemical properties of the target site, combining PAI with USI can provide both chemical and structural information about a target tissue.

One distinctive advantage of PAI is that its resolution and imaging depth can be adjusted to suit a specific target area. The resolution of PA signals depends on both the optical focus of the excitation laser and the acoustic focus of the receiving US transducer [22], so images with tuned spatial resolutions and imaging depths can be achieved by modifying the system configuration [23]. PAI’s wide applications to date have included nanoscale surface and organelle imaging [24,25,26,27,28], microscale cellular imaging [29,30,31,32], macroscale small animal imaging [33,34,35], and clinical human imaging [36,37,38].

Oct 2, 2023

Total Triterpenes of Wolfiporia cocos (Schwein.) Ryvarden & Gilb Exerts Antidepressant-Like Effects in a Chronic Unpredictable Mild Stress Rat Model and Regulates the Levels of Neurotransmitters, HPA Axis and NLRP3 Pathway

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

Purpose: Wolfiporia cocos is frequently used in traditional Chinese medicine to treat depression. However, antidepressant-like effects of the main active ingredients of Wolfiporia cocos, total triterpenes of Wolfiporia cocos (TTWC), are not well studied. This study aimed to investigate those effects and explore their specific mechanisms of action in depth. Methods: Chemical components of TTWC were analyzed using LC-MS. Depression-like behavior in rats were induced by chronic unpredictable mild stress (CUMS). The suppressive effects of TTWC (60120240 mg/kg) against CUMS-induced depression-like behavior were evaluated using the forced swimming test (FST), open field test (OFT) and sucrose preference test (SPT). Levels of 5-hydroxytryptamine (5-HT), glutamate (GLU), corticotropin-releasing hormone (CRH), interleukin-1 beta (IL-1beta), interleukin-18 (IL-18), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in different groups were determined by ELISA. Western blotting (WB) was used to detect the expression of NLRP3, ASC, pro-caspase-1, caspase-1, pro-IL-1beta, IL-1beta, pro-IL-18, and IL-18 in the prefrontal cortex. Additionally, the mRNA levels of NLRP3, ASC, caspase-1, IL-1beta and IL-18 were detected by RT-PCR. Results: A total of 69 lanostane-type triterpene acids of TTWC were identified. The results showed that TTWC exhibited an antidepressant-like effect in CUMS rats, reversed the decreased sugar preference in the SPT, reduction of immobility time in the FST, reduced the rest time, increased the total moving distance in the OFT. TTWC increased 5-HT levels and decreased GLU levels in the hippocampus. Moreover, TTWC decreased CRH levels in serum, indicating the regulation of over-activation of the hypothalamic-pituitary-adrenal (HPA) axis. In addition, reduced serum levels of IL-1beta, IL-18, IL-6, and TNF-alpha. The WB results implied that TTWC inhibited the expression of NLRP3, ASC, caspase-1, IL-1beta, and IL-18 in the prefrontal cortex and enhanced the expression of pro-caspase-1, pro-IL-1beta, and pro-IL-18. Although most of the results were not significant, PCR results showed that TTWC inhibited the expression of NLRP3, ASC, caspase-1, IL-1beta, and IL-18 in the prefrontal cortex. Conclusion: TTWC treatment exerted an antidepressant-like effect and regulates neurotransmitters, HPA axis and NLRP3 signaling pathway. These results indicated the potential of TTWC in preventing the development of depression.

Keywords: NLRP3 pathway; Wolfiporia cocos (schwein.) ryvarden & gilb; chronic unpredictable mild stress; depression; hypothalamic-pituitary-adrenal axis; neurotransmitter; triterpenes.

Copyright © 2022 Pan, Chen, Han, Luo, Zhang, Zhang, Zhang, Zhou, Li, Fang, Wang and Ye.

Sep 30, 2023

Striking rare gold: Researchers unveil new material infused with gold in an exotic chemical state

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

For the first time, Stanford researchers have found a way to create and stabilize an extremely rare form of gold that has lost two negatively charged electrons, denoted Au2+. The material stabilizing this elusive version of the valued element is a halide perovskite—a class of crystalline materials that holds great promise for various applications including more-efficient solar cells, light sources, and electronics components.

Surprisingly, the Au2+ is also quick and simple to make using off-the-shelf ingredients at .

“It was a real surprise that we were able to synthesize a stable material containing Au2+ —I didn’t even believe it at first,” said Hemamala Karunadasa, associate professor of chemistry at the Stanford School of Humanities and Sciences and senior author of the study published Aug. 28 in Nature Chemistry. “Creating this first-of-its-kind Au2+ perovskite is exciting. The in the perovskite bear strong similarities to the copper atoms in high-temperature superconductors, and heavy atoms with unpaired electrons, like Au2+, show cool magnetic effects not seen in lighter atoms.”

Sep 30, 2023

Small Strands of Genetic Code Can Enhance Immunotherapy

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

Ribonucleic acid (RNA) is a molecule which is present in cells and made of genetic material to help build proteins necessary for cell function. RNA provides a template for the construction of proteins and is essential for cell and organism life. Immune cells rely on these proteins, including CD8+ or cytotoxic T cells which are responsible for killing invading pathogens. Importantly, cytotoxic T cells are a major component of the memory immune response. A pool of T cells specifically designed to recognize an invader is stored for future invasion of that particular pathogen. For example, once these cells are exposed to an invading antigen or protein, the immune system will expand T cells specific to that antigen and remember the antigen next time it enters the body. Vaccines work in a similar way by introducing a foreign antigen to the body, so the immune system is ready if the pathogen ever enters your body in the future. Only a small set of T cells that expand survive and it is unclear how this process occurs.

Recently a team of researchers at the University of Massachusetts Amherst (UMass) demonstrated that a single strand of RNA governs a T cells ability to recognize and kill tumors. The single strand of RNA is known as let-7 and is a microRNA, which is responsible for gene expression regulation. The recent discovery may improve vaccine development and cellular memory to enhance immunotherapy against cancers. Immunotherapy is a general term referring to cancer therapies that try to activate the immune system to kill the tumor compared to other drugs that try to directly kill the tumor with chemicals, such as chemotherapy.

The report published in Nature Communications identified that the microRNA, let-7, may enhance memory of T cells. Researchers led by Dr. Leonid Pobezinsky, Associate Professor of Veterinary and Animal Sciences at UMass, further built on our understanding of how T cells form immune memory. Pobezinsky and colleagues found that a small piece of microRNA that has been present throughout evolution is expressed in memory cells. Additionally, they found that more let-7 a cell has, the more likely that cell will recognize a cancer cell and kill it. The increased let-7 also indicates that the cell will turn into a memory cell after being exposed to an antigen. The regulation of enhanced memory T cells by let-7 is an integral process key to fight infections. This is a critical finding, especially because memory cells retain stem-like characteristics and can survive for decades.

Sep 29, 2023

Milestone for novel atomic clock: X-ray laser shows possible route to substantially increased precision time measurement

Posted by in categories: chemistry, particle physics

An international research team has taken a decisive step toward a new generation of atomic clocks. At the European XFEL X-ray laser, the researchers have created a much more precise pulse generator based on the element scandium, which enables an accuracy of one second in 300 billion years—that is about a thousand times more precise than the current standard atomic clock based on cesium. The team presents its success in the journal Nature.

Atomic clocks are currently the world’s most accurate timekeepers. These clocks have used electrons in the atomic shell of chemical elements, such as cesium, as a pulse generator in order to define the time. These electrons can be raised to a higher energy level with microwaves of a known frequency. In the process, they absorb the .

An atomic clock shines microwaves at cesium atoms and regulates the frequency of the radiation such that the absorption of the microwaves is maximized; experts call this a resonance. The quartz oscillator that generates the microwaves can be kept so stable with the help of resonance that cesium clocks will be accurate to within one second within 300 million years.

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