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Archive for the ‘chemistry’ category: Page 269

Dec 1, 2020

A strategy to transform the structure of metal-organic framework electrocatalysts

Posted by in categories: chemistry, energy

The oxygen evolution reaction (OER) is a chemical process that leads to the generation of molecular oxygen. This reaction is of key importance for the development of clean energy technologies, including water electrolyzers, regenerative fuel cells and rechargeable metal-air batteries.

The extent to which this reaction occurs has so far been limited in many materials, which has restricted the conversion efficiency of some types of technologies. Materials scientists have thus been trying to identify alternative materials, including metals, and hydroxides, that could be used as electrocatalysts to fuel this reaction. The materials identified so far, however, are far from ideal for large-scale implementation, as they are either not particularly resistant or too expensive.

A class of materials widely investigated as possible electrocatalysts for the OER are (MOFs), hybrid and crystalline compounds that consist of a regular array of positively charged metal ions surrounded by organic molecules. While these materials have promising , scientists have yet to identify optimal strategies to enhance their performance.

Nov 30, 2020

New family of quasiparticles appears in graphene

Posted by in categories: chemistry, computing, mathematics, particle physics

Researchers identify Brown-Zak fermions in superlattices made from the carbon sheet.


Researchers at the University of Manchester in the UK have identified a new family of quasiparticles in superlattices made from graphene sandwiched between two slabs of boron nitride. The work is important for fundamental studies of condensed-matter physics and could also lead to the development of improved transistors capable of operating at higher frequencies.

In recent years, physicists and materials scientists have been studying ways to use the weak (van der Waals) coupling between atomically thin layers of different crystals to create new materials in which electronic properties can be manipulated without chemical doping. The most famous example is graphene (a sheet of carbon just one atom thick) encapsulated between another 2D material, hexagonal boron nitride (hBN), which has a similar lattice constant. Since both materials also have similar hexagonal structures, regular moiré patterns (or “superlattices”) form when the two lattices are overlaid.

Continue reading “New family of quasiparticles appears in graphene” »

Nov 29, 2020

How to make the food and water Mars-bound astronauts will need for their mission

Posted by in categories: chemistry, food, space, sustainability

The technology doesn’t seem to be here yet; obviously, the ice on Mars will be harvested to provide drinking and irrigation water.


If we ever intend to send crewed missions to deep-space locations, then we need to come up with solutions for keeping the crews supplied. For astronauts aboard the International Space Station (ISS), who regularly receive resupply missions from Earth, this is not an issue. But for missions traveling to destinations like Mars and beyond, self-sufficiency is the name of the game.

Continue reading “How to make the food and water Mars-bound astronauts will need for their mission” »

Nov 26, 2020

New protein imaging method paves way for next generation biomaterials and tissue analysis

Posted by in categories: biotech/medical, chemistry

Scientists have established a new method to image proteins that could lead to new discoveries in disease through biological tissue and cell analysis and the development of new biomaterials that can be used for the next generation of drug delivery systems and medical devices.

Scientists from the University of Nottingham in collaboration with the University of Birmingham and The National Physical laboratory have used the state-of-the-art 3D OrbiSIMS instrument to facilitate the first matrix- and label-free in situ assignment of intact proteins at surfaces with minimal sample preparation. Their research has been published today in Nature Communications.

The University of Nottingham is the first University in the world to own a 3D OrbiSIMS instrument. It is able to facilitate an unprecedented level of mass spectral molecular analysis for a range of materials (hard and soft matter, biological cells and tissues). The facility in Nottingham also has freezing cryo-preparation facilities that enable biological samples to be maintained close to their native state as frozen-hydrated to complement the more commonly applied but more disruptive freeze drying and sample fixation. When the surface sensitivity, high mass/spatial resolution are combined with a depth profiling sputtering beam, the instrument becomes an extremely powerful tool for 3D chemical analysis as demonstrated in this recent work.

Nov 23, 2020

Microfluidic Brain-on-a-Chip: Perspectives for Mimicking Neural System Disorders

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

Neurodegenerative diseases (NDDs) include more than 600 types of nervous system disorders in humans that impact tens of millions of people worldwide. Estimates by the World Health Organization (WHO) suggest NDDs will increase by nearly 50% by 2030. Hence, development of advanced models for research on NDDs is needed to explore new therapeutic strategies and explore the pathogenesis of these disorders. Different approaches have been deployed in order to investigate nervous system disorders, including two-and three-dimensional (2D and 3D) cell cultures and animal models. However, these models have limitations, such as lacking cellular tension, fluid shear stress, and compression analysis; thus, studying the biochemical effects of therapeutic molecules on the biophysiological interactions of cells, tissues, and organs is problematic. The microfluidic “organ-on-a-chip” is an inexpensive and rapid analytical technology to create an effective tool for manipulation, monitoring, and assessment of cells, and investigating drug discovery, which enables the culture of various cells in a small amount of fluid (10−9 to 10−18 L). Thus, these chips have the ability to overcome the mentioned restrictions of 2D and 3D cell cultures, as well as animal models. Stem cells (SCs), particularly neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs) have the capability to give rise to various neural system cells. Hence, microfluidic organ-on-a-chip and SCs can be used as potential research tools to study the treatment of central nervous system (CNS) and peripheral nervous system (PNS) disorders. Accordingly, in the present review, we discuss the latest progress in microfluidic brain-on-a-chip as a powerful and advanced technology that can be used in basic studies to investigate normal and abnormal functions of the nervous system.

Nov 23, 2020

Scientists observe directed energy transport between neighboring molecules in a nanomaterial

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

When light falls on a material, such as a green leaf or the retina, certain molecules transport energy and charge. This ultimately leads to the separation of charges and the generation of electricity. Molecular funnels, so-called conical intersections, ensure that this transport is highly efficient and directed.

An international team of physicists has now observed that such conical intersections also ensure a directed energy transport between neighboring of a nanomaterial. Theoretical simulations have confirmed the . Until now, scientists had observed this phenomenon only within one molecule. In the long term, the results could help to develop more efficient nanomaterials for organic solar cells, for example. The study, led by Antonietta De Sio, University of Oldenburg, and Thomas Frauenheim, University of Bremen, Germany, was published in the current issue of the scientific journal Nature Nanotechnology.

Photochemical processes play a major role in nature and in technology: When molecules absorb light, their electrons transit to an excited state. This transition triggers extremely fast molecular switching processes. In the human eye, for example, the molecule rhodopsin rotates in a certain way after absorbing light and thus ultimately triggers an electrical signal—the most elementary step in the visual process.

Nov 23, 2020

Chemical reactions high in Mars’ atmosphere rip apart water molecules

Posted by in categories: chemistry, space

Mars is so dry because its water constant escapes into space. A new study suggests this process occurs in the ionosphere and faster than thought.

Nov 20, 2020

Getting it just right: The Goldilocks model of cancer

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

Senescence in cancer cells

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Sometimes, too much of a good thing can turn out to be bad. This is certainly the case for the excessive cell growth found in cancer. But when cancers try to grow too fast, this excessive speed can cause a type of cellular aging that actually results in arrested growth. Scientists at Duke-NUS Medical School have now discovered that a well-known signaling pathway helps cancers grow by blocking the pro-growth signals from a second major cancer pathway.

Continue reading “Getting it just right: The Goldilocks model of cancer” »

Nov 19, 2020

Dipole Drive for space propulsion | Robert Zubrin at Breakthrough Discuss 2018

Posted by in categories: chemistry, space travel

Circa 2018


The speed of space travel is currently limited by the quantity of chemical fuel that spacecraft must carry. Robert Zubrin, President of Pioneer Astronautics, introduces the dipole drive — a new propulsion system which uses ambient space plasma as propellant, thereby avoiding the need to carry its own.

Nov 19, 2020

Near-infrared probe decodes telomere dynamics

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

A new synthetic probe offers a safe and straightforward approach for visualizing chromosome tips in living cells. The probe was designed by scientists at the Institute for Integrated Cell-Material Science (iCeMS) and colleagues at Kyoto University, and could advance research into aging and a wide range of diseases, including cancers. The details were published in the Journal of the American Chemical Society.

“Chromosome ends are constantly at risk of degradation and fusion, so they are protected by structures called telomeres, which are made of long repeating DNA sequences and bound proteins,” says iCeMS chemical biologist Hiroshi Sugiyama, who led the study. “If telomeres malfunction, they are unable to maintain chromosome stability, which can lead to diseases such as cancer. Also, telomeres normally shorten with each cell division until they reach their limit, causing cell death.”

Visualizing telomeres, especially their physical arrangements in , is important for understanding their relevance to disease and aging. Several visualization approaches already exist, but they have disadvantages. For example, some can only observe telomeres in preserved, or fixed, cells. Others are time-consuming or involve harsh treatments that denature DNA.