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Archive for the ‘chemistry’ category: Page 25

Jul 9, 2024

Sustaining wakefulness: Brainstem connectivity in human consciousness

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

Consciousness is comprised of arousal (i.e., wakefulness) and awareness. Substantial progress has been made in mapping the cortical networks that modulate awareness in the human brain, but knowledge about the subcortical networks that sustain arousal is lacking. We integrated data from ex vivo diffusion MRI, immunohistochemistry, and in vivo 7 Tesla functional MRI to map the connectivity of a subcortical arousal network that we postulate sustains wakefulness in the resting, conscious human brain, analogous to the cortical default mode network (DMN) that is believed to sustain self-awareness. We identified nodes of the proposed default ascending arousal network (dAAN) in the brainstem, hypothalamus, thalamus, and basal forebrain by correlating ex vivo diffusion MRI with immunohistochemistry in three human brain specimens from neurologically normal individuals scanned at 600–750 µm resolution. We performed deterministic and probabilistic tractography analyses of the diffusion MRI data to map dAAN intra-network connections and dAAN-DMN internetwork connections. Using a newly developed network-based autopsy of the human brain that integrates ex vivo MRI and histopathology, we identified projection, association, and commissural pathways linking dAAN nodes with one another and with cortical DMN nodes, providing a structural architecture for the integration of arousal and awareness in human consciousness. We release the ex vivo diffusion MRI data, corresponding immunohistochemistry data, network-based autopsy methods, and a new brainstem dAAN atlas to support efforts to map the connectivity of human consciousness.

One sentence summary We performed ex vivo diffusion MRI, immunohistochemistry, and in vivo 7 Tesla functional MRI to map brainstem connections that sustain wakefulness in human consciousness.

BF has a financial interest in CorticoMetrics, a company whose medical pursuits focus on brain imaging and measurement technologies. BF’s interests were reviewed and are managed by Massachusetts General Hospital and Mass General Brigham HealthCare in accordance with their conflict-of-interest policies.

Jul 8, 2024

Researchers Develop World’s First Anode-Free Sodium Solid-State Battery

Posted by in categories: chemistry, engineering, sustainability, transportation

UChicago Pritzker Molecular Engineering Prof. Y. Shirley Meng’s Laboratory for Energy Storage and Conversion has created the world’s first anode-free sodium solid-state battery.

With this research, the LESC – a collaboration between the UChicago Pritzker School of Molecular Engineering and the University of California San Diego’s Aiiso Yufeng Li Family Department of Chemical and Nano Engineering – has brought the reality of inexpensive, fast-charging, high-capacity batteries for electric vehicles and grid storage closer than ever.

“Although there have been previous sodium, solid-state, and anode-free batteries, no one has been able to successfully combine these three ideas until now,” said UC San Diego PhD candidate Grayson Deysher, first author of a new paper outlining the team’s work.

Jul 8, 2024

New material paves the way to on-chip energy harvesting

Posted by in categories: chemistry, computing

Researchers from Germany, Italy, and the UK have achieved a major advance in the development of materials suitable for on-chip energy harvesting. By composing an alloy made of silicon, germanium and tin, they were able to create a thermoelectric material, promising to transform the waste heat of computer processors back into electricity.

With all elements coming from the 4th main group of the periodic table, these new semiconductor alloy can be easily integrated into the CMOS process of chip production. The research findings are published in ACS Applied Energy Materials.

The increasing use of electronic devices in all aspects of our lives is driving up energy consumption. Most of this energy is dissipated into the environment in the form of heat.

Jul 5, 2024

NASA seeks industry support in GLIMR concept study

Posted by in categories: biological, chemistry, economics, engineering, space, sustainability

WASHINGTON — The National Aeronautics and Space Administration (NASA) has announced that the agency is seeking assistance from industry as it begins a study into its Geostationary Littoral Imaging and Monitoring Radiometer (GLIMR) Access to Space (ATS) approach.

The GLIMR mission aims to provide transformative rapid observations of dynamic coastal zone ecosystems throughout the Gulf of Mexico (GoM) and coastal continental U.S. (CONUS). Its goal is to observe and monitor ocean biology, chemistry, and ecology to help protect ecosystem sustainability, improve resource management, and enhance economic activity. This includes identifying and tracking harmful algal blooms and oil spills, while also observing, quantifying, and understanding processes associated with rapid changes in phytoplankton growth.

The GLIMR ATS scope is expected to include several key components and activities: the spacecraft itself, the launch vehicle, the integration and testing of the GLIMR payload with the spacecraft, and the integration of the spacecraft with the launch vehicle and subsequent launch. It will also cover the command uplink from the industry-provided Mission Operations Center (MOC), the downlink of GLIMR engineering and science telemetry to industry-allocated ground stations, and the delivery of error-checked GLIMR data to various mission partners. Additionally, it encompasses all related tasks and support required during the planned GLIMR Mission, such as pre-launch planning, launch support, in-orbit check-out, and operations.

Jul 5, 2024

Researchers pioneer new methods in ultrafast science for sharper molecular movies

Posted by in categories: chemistry, science

Imagine being able to watch the inner workings of a chemical reaction or a material as it changes and reacts to its environment—that’s the sort of thing researchers can do with a high-speed “electron camera” called the Megaelectronvolt Ultrafast Electron Diffraction (MeV-UED) instrument at the Linac Coherent Light Source (LCLS) at the U.S. Department of Energy’s SLAC National Accelerator Laboratory.

Now, in two new studies, researchers from SLAC, Stanford and other institutions have figured out how to capture those tiny, ultrafast details with more accuracy and efficiency.

In the first study, recently published in Structural Dynamics, one team invented a technique to improve for the electron camera.

Jul 3, 2024

Researchers discover photo-induced charge-transfer complex between amine and imide

Posted by in categories: chemistry, energy

A research team led by Prof. Zhang Guoqing from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) has discovered a highly reactive photo-induced charge-transfer complex (PCTC) between amine and imide. Their findings are published in the journal Chem.

Charge transfer between molecules, a critical process in both natural and synthetic systems, plays a fundamental role in photosynthesis, respiration, and various organic synthesis and energy conversion applications.

Despite extensive research, creating stable, light-responsive charge-transfer complexes in artificial systems remains challenging. The discovery of PCTCs addresses this challenge, offering new insights into complex photochemical processes.

Jul 3, 2024

An inexpensive, easy-to-use method to create solid-state nanopores

Posted by in categories: biotech/medical, chemistry

SMU and the University of Rhode Island have patented an inexpensive, easy-to-use method to create solid-state nanopores (SSNs), while also making it possible to self-clean blocked nanopores.

The technique called chemically-tuned controlled dielectric breakdown (CT-CDB) addresses two key problems that have kept solid-state nanopores – which are too tiny for the human eye to see – from being used more often to build biosensors that can measure biological and chemical reactions of a given sample.

Biosensors have widespread medical applications, enabling rapid, early and effective disease diagnosis and monitoring.

Jul 1, 2024

Reconnaissance of Potentially Habitable Worlds with Webb

Posted by in categories: alien life, chemistry

Exoplanets are common in our galaxy, and some even orbit in the so-called habitable zone of their star. NASA’s James Webb Space Telescope has been busy observing a few of these small, potentially habitable planets, and astronomers are now hard at work analyzing Webb data. We invite Drs. Knicole Colón and Christopher Stark, two Webb project scientists at NASA’s Goddard Space Flight Center, to tell us more about the challenges in studying these other worlds:

A potentially habitable planet is often defined as a planet similar in size to Earth that orbits in the ‘habitable zone’ of its star, a location where the planet could have a temperature where liquid water could exist on its surface. We currently know of around 30 planets that may be small, rocky planets like Earth and that orbit in the habitable zone. However, there is no guarantee that a planet that orbits in the habitable zone actually is habitable (it could support life), let alone inhabited (it currently supports life). At the time of writing, there is only one known habitable and inhabited planet—Earth.

The potentially habitable worlds Webb is observing are all transiting exoplanets, meaning their orbits are nearly edge-on so that they pass in front of their host stars. Webb takes advantage of this orientation to perform transmission spectroscopy when the planet passes in front of its star. This orientation allows us to examine the starlight filtered through the atmospheres of planets to learn about their chemical compositions.

Jun 30, 2024

First Step in Allergic Reactions, Paving the way for New Preventative Strategies

Posted by in categories: biotech/medical, chemistry, food, health

Scientists at Duke-NUS Medical School have identified how the first domino falls after a person encounters an allergen, such as peanuts, shellfish, pollen or dustmites. Their discovery, published in the April issue of Nature Immunology, could herald the development of drugs to prevent these severe reactions.

It is well established that when mast cells, a type of immune cell, mistake a harmless substance, such as peanuts or dust mites, as a threat, they release an immediate first wave of bioactive chemicals against the perceived threat. When mast cells, which reside under the skin, around blood vessels and in the linings of the airways and the gastrointestinal tract, simultaneously release their pre-stored load of bioactive chemicals into the blood, instant and systemic shock can result, which can be lethal without quick intervention.

More than 10 per cent of the global population suffers from food allergies, according to the World Health Organisation (WHO). As allergy rates continue to climb, so does the incidence of food-triggered anaphylaxis and asthma worldwide. In Singapore, asthma affects one in five children while food allergies are already the leading cause of anaphylactic shock.

Jun 29, 2024

Defying Limits: Discovery of New Membrane Behavior Could Lead to Unprecedented Separations

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

Recent research on isoporous membranes, which feature uniformly sized pores, show potential for improving the precision and efficiency of industrial separation processes by allowing solutes multiple attempts to pass through the pores.

Imagine a close basketball game that comes down to the final shot. The probability of the ball going through the hoop might be fairly low, but it would dramatically increase if the player were afforded the opportunity to shoot it over and over.

A similar idea is at play in the scientific field of membrane separations, a key process central to industries that include everything from biotechnology to petrochemicals to water treatment to food and beverage.

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