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Category: chemistry – Page 34

Electrons travel one of two routes in nano-biohybrid systems

Peanut butter and jelly. Simon and Garfunkel. Semiconductors and bacteria. Some combinations are more durable than others. In recent years, an interdisciplinary team of Cornell researchers has been pairing microbes with the semiconductor nanocrystals known as quantum dots, with the goal of creating nano-biohybrid systems that can harvest sunlight to perform complex chemical transformations for materials and energy applications.

Now, the team has for the first time identified exactly what happens when a microbe receives an electron from a quantum dot: The charge can either follow a direct pathway or be transferred indirectly via the microbe’s shuttle molecules.

The findings are published in Proceedings of the National Academy of Sciences. The lead author is Mokshin Suri.

Epidermal Growth Factor Stability and Cell Proliferation Enhanced by Antioxidants

1. Introduction.

The natural production of EGF, a short polypeptide hormone, promotes the processes of proliferation, expansion, and division of cells [1]. For in vitro cell culture, EGF functions as a growth factor [2] and has an effective mitogenic effect on endothelial cells, fibroblasts, and most epithelial tissues. Its biological functions rely on associating itself with a specific cell membrane receptor [3]. Because EGF plays a crucial role as a mitogen in the proliferation of various cell types both in vivo and in vitro, it has been used in the therapeutic and cosmetic areas [4] to cover scars and reduce the appearance of aging skin [1]. Moreover, recombinant EGF is used topically for diabetic foot ulcers [5]. The structures and properties of proteins vary; favorable conditions are necessary for conformation, stability, and proper function. In contrast, a protein degrades, denatures, or precipitates when it is exposed to unfavorable conditions or when its natural environment changes suddenly. Recombinant human EGF is most frequently degraded by oxidation and deamidation [6]. These reactions typically have long-term implications. For protein solutions to remain stable and have a longer shelf life, excipients may need to be added, depending on how the protein is used in the experiment and other factors. When it comes to the chemical and physical degradation of proteins, the solution environment plays a crucial role in protein formulations. Of particular concern are buffer types, pH, and antioxidants [7]. Even though antioxidants assist in stability and solubility in liquid solutions, which help to preserve protein structure and function, they are frequently considered inactive ingredients in pharmaceutical compositions [8] [9].

Since an unstable protein solution can impact the product’s appearance, potency, purity, healing effects, and cell proliferation, in vitro protein stabilization is an essential practical consideration for the development of an effective EGF formulation. The stability of EGF in solution has been well documented in several in vivo solutions [10]. Though there have been numerous reports on EGF stability, none have specifically addressed treatment in cell culture conditions. Since it has a big influence on several aspects of the parenteral formulation creation process and EGF-based cell proliferation, the study of EGF stability in cell culture medium has gotten little attention. But since many of these in vitro tests are conducted in non-physiological settings, such as organic solvents or acidic solutions [11], they frequently fail to yield qualitatively positive results in cellular therapies.

Advancing light-to-electricity energy conversion: New method extends lifespan of plasmonic hot holes

When light interacts with metallic nanostructures, it instantaneously generates plasmonic hot carriers, which serve as key intermediates for converting optical energy into high-value energy sources such as electricity and chemical energy. Among these, hot holes play a crucial role in enhancing photoelectrochemical reactions. However, they thermally dissipate within picoseconds (trillionths of a second), making practical applications challenging.

Now, a Korean research team has successfully developed a method for sustaining hot holes longer and amplifying their flow, accelerating the commercialization of next-generation, high-efficiency, light-to-energy conversion technologies.

The research team, led by Distinguished Professor Jeong Young Park from the Department of Chemistry at KAIST, in collaboration with Professor Moonsang Lee from the Department of Materials Science and Engineering at Inha University, has successfully amplified the flow of hot holes and mapped local current distribution in real time, thereby elucidating the mechanism of photocurrent enhancement. The work is published in Science Advances.

The emerging armamentarium of cognitive warfare with Dr. James Giordano | CSI Talks #19

Convergent engagement of neural and computational sciences and technologies are reciprocally enabling rapid developments in current and near-future military and intelligence operations. In this podcast, Prof. James Giordano of Georgetown University will provide an overview of how these scientific and technological fields can be — and are being — leveraged for non-kinetic and kinetic what has become known as cognitive warfare; and will describe key issues in this rapidly evolving operational domain.

James Giordano PhD, is the Pellegrino Center Professor in the Departments of Neurology and Biochemistry; Chief of the Neuroethics Studies Program; Co-director of the Project in Brain Sciences and Global Health Law and Policy; and Chair of the Subprogram in Military Medical Ethics at Georgetown University Medical Center, Washington DC. Professor Giordano is Senior Bioethicist of the Defense Medical Ethics Center, and Adjunct Professor of Psychiatry at the Uniformed Services University of Health Sciences; Distinguished Stockdale Fellow in Science, Technology, and Ethics at the United States Naval Academy; Senior Science Advisory Fellow of the SMA Branch, Joint Staff, Pentagon; Non-resident Fellow of the Simon Center for the Military Ethic at the US Military Academy, West Point; Distinguished Visiting Professor of Biomedical Sciences, Health Promotions, and Ethics at the Coburg University of Applied Sciences, Coburg, GER; Chair Emeritus of the Neuroethics Project of the IEEE Brain Initiative; and serves as Director of the Institute for Biodefense Research, a federally funded Washington DC think tank dedicated to addressing emerging issues at the intersection of science, technology and national defense. He previously served as Donovan Group Senior Fellow, US Special Operations Command; member of the Neuroethics, Legal, and Social Issues Advisory Panel of the Defense Advanced Research Projects Agency (DARPA); and Task Leader of the Working Group on Dual-Use of the EU-Human Brain Project. Prof. Giordano is the author of over 350 peer-reviewed publications, 9 books and 50governmental reports on science, technology, and biosecurity, and is an elected member of the European Academy of Science and Arts, a Fellow of the Royal Society of Medicine (UK), and a Fulbright Professorial Fellow. A former US Naval officer, he was winged as an aerospace physiologist, and served with the US Navy and Marine Corps.

Ion pairing with gold complexes offers new path for organic electronics

Unsubstituted π-electronic systems with expanded π-planes are highly desirable for improving charge-carrier transport in organic semiconductors. However, their poor solubility and high crystallinity pose major challenges in processing and assembly, despite their favorable electronic properties. The strategic arrangement of these molecular structures is crucial for achieving high-performance organic semiconductive materials.

In a significant breakthrough, a research team led by Professor Hiromitsu Maeda from Ritsumeikan University, including Associate Professor Yohei Haketa from Ritsumeikan University, Professor Shu Seki from Kyoto University, and Professor Go Watanabe from Kitasato University, has synthesized a novel organic electronic system incorporating gold (AuIII) and benzoporphyrin molecules, enabling enhanced solubility and conductivity.

The findings of the study were published online in Chemical Science.

Selective Glycan Labeling of Mannose-Containing Glycolipids in MycobacteriaClick to copy article linkArticle link copied!

An interesting article where Lee et al. develop a new chemical label for studying the dynamics of select glycolipids found in tuberculosis bacteria. They target specific types of glycolipids that are involved in pathogenesis, opening the door to new insights on tuberculosis. As tuberculosis kills more than a million people every year, tools for studying the disease are sorely needed. #chemicalbiology #chemistry #microbiology

Supercritical water’s structure decoded: Analysis finds no molecular clusters, just fleeting bonds

Researchers at Ruhr University Bochum, Germany, have shed light on the structure of supercritical water. In this state, which exists at extreme temperatures and pressures, water has the properties of both a liquid and a gas at the same time. According to one theory, the water molecules form clusters, within which they are then connected by hydrogen bonds.

The Bochum-based team has now disproven this hypothesis using a combination of terahertz spectroscopy and molecular dynamics simulations. The results are published in the journal Science Advances.

The experimentalists Dr. Katja Mauelshagen, Dr. Gerhard Schwaab and Professor Martina Havenith from the Chair of Physical Chemistry II collaborated with Dr. Philipp Schienbein and Professor Dominik Marx from the Chair of Theoretical Chemistry.

Machine learning enables customized plastics that could reduce environmental impact

About 100 million metric tons of high-density polyethylene (HDPE), one of the world’s most commonly used plastics, are produced annually, using more than 15 times the energy needed to power New York City for a year and adding enormous amounts of plastic waste to landfills and oceans.

Cornell chemistry researchers have found ways to reduce the environmental impact of this ubiquitous —found in milk jugs, shampoo bottles, playground equipment and many other things—by developing a machine-learning model that enables manufacturers to customize and improve HDPE materials, decreasing the amount of material needed for various applications. It can also be used to boost the quality of recycled HDPE to rival new, making recycling a more practical process.

“Implementation of this approach will facilitate the design of next-generation commodity materials and enable more efficient polymer recycling, lowering the overall impact of HDPE on the environment,” said Robert DiStasio Jr., associate professor of chemistry and chemical biology in the College of Arts and Sciences (A&S).

Quantum behaviour in brain neurons looks theoretically possible

A new study probing quantum phenomena in neurons as they transmit messages in the brain could provide fresh insight into how our brains function.

In this project, described in the Computational and Structural Biotechnology Journal, theoretical physicist Partha Ghose from the Tagore Centre for Natural Sciences and Philosophy in India, together with theoretical neuroscientist Dimitris Pinotsis from City St George’s, University of London and the MillerLab of MIT, proved that established equations describing the classical physics of brain responses are mathematically equivalent to equations describing quantum mechanics. Ghose and Pinotsis then derived a Schrödinger-like equation specifically for neurons.

Our brains process information via a vast network containing many millions of neurons, which can each send and receive chemical and electrical signals. Information is transmitted by nerve impulses that pass from one neuron to the next, thanks to a flow of ions across the neuron’s cell membrane. This results in an experimentally detectable change in electrical potential difference across the membrane known as the “action potential” or “spike”