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Archive for the ‘chemistry’ category: Page 120

Jun 29, 2023

This Plasma Engine Could Get Humans to Mars on 100 Million Times Less Fuel

Posted by in categories: chemistry, energy, physics, satellites

Year 2015 😗😁


Physicists in France have figured out how to optimise an advanced type of electric rocket thruster that uses a stream of plasma travelling at 72,420 km/h (45,000 mph) to propel spacecraft forward, allowing them to run on 100 million times less fuel than conventional chemical rockets.

Known as a Hall thruster, these engines have been operating in space since 1971, and are now routinely flown on communication satellites and space probes to adjust their orbits when needed. These things are awesome, and scientists want to use them to get humans to Mars, except there’s one — rather large — problem: the current lifespan of a Hall thruster is around 10,000 operation hours, and that’s way too short for most space exploration missions, which require upwards of 50,000 hours.

Continue reading “This Plasma Engine Could Get Humans to Mars on 100 Million Times Less Fuel” »

Jun 29, 2023

Artificially cultured brains improve processing of time series data, shows study

Posted by in categories: chemistry, computing

The brain comprises billions of interconnected neurons that transmit and process information and allow it to act as a highly sophisticated information processing system. To make it as efficient as possible, the brain develops multiple modules tasked with different functions, like perception and body control. Within a single area, neurons form multiple clusters and function as modules—an important trait that has remained essentially unchanged throughout evolution.

Still, many unanswered questions remain regarding how the specific structure of the brain’s network, such as the modular structure, works together with the physical and chemical properties of neurons to process information.

Reservoir computing is a inspired by the brain’s powers, where the comprises a large number of interconnected nodes that transform input signals into a more complex representation.

Jun 28, 2023

Oxygen restriction helps fast-aging lab mice live longer

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

For the first time, researchers have shown that reduced oxygen intake, or “oxygen restriction,” is associated with longer lifespan in lab mice, highlighting its anti-aging potential. Robert Rogers of Massachusetts General Hospital in Boston, US, and colleagues present these findings in a study published May 23rd in the open access journal PLOS Biology.

Research efforts to extend healthy lifespan have identified a number of chemical compounds and other interventions that show promising effects in mammalian lab animals— for instance, the drug metformin or . Oxygen restriction has also been linked to longer lifespan in yeast, nematodes, and fruit flies. However, its effects in mammals have been unknown.

To explore the anti-aging potential of oxygen restriction in mammals, Rogers and colleagues conducted lab experiments with mice bred to age more quickly than other mice while showing classic signs of mammalian aging throughout their bodies. The researchers compared the lifespans of mice living at normal atmospheric oxygen levels (about 21%) to the lifespans of mice that, at 4 weeks of age, had been moved to a living environment with a lower proportion of oxygen (11%—similar to that experienced at an altitude of 5,000 meters).

Jun 28, 2023

New mass spectrometry combo offers promise for tapping nature’s unknown chemical universe

Posted by in categories: biotech/medical, chemistry

The universe is awash in billions of possible chemicals. But even with a bevy of high-tech instruments, scientists have determined the chemical structures of just a small fraction of those compounds, maybe 1%.

Scientists at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) are taking aim at the other 99%, creating new ways to learn more about a vast sea of unknown compounds. There may be cures for disease, new approaches for tackling climate change, or new chemical or biological threats lurking in the chemical universe.

The work is part of an initiative known as m/q, or “m over q” —shorthand for mass divided by charge, which signifies one of the ways that scientists measure chemical properties in the world of .

Jun 28, 2023

Chemical imbalance in the forebrain underpins compulsive behavior and OCD, study reveals

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

Scientists at the University of Cambridge have used powerful new brain imaging techniques to reveal a neurochemical imbalance within regions of the frontal lobes in patients with obsessive-compulsive disorder (OCD). The research findings are published in the journal Nature Communications.

The study shows that the balance between glutamate and GABA—two major neurotransmitter chemicals—is “disrupted” in OCD patients in two frontal regions of the brain.

Researchers also found that people who do not have OCD but are prone to habitual and compulsive behavior have increased glutamate levels in one of these brain regions.

Jun 27, 2023

A surprise chemical find by ALMA may help detect and confirm protoplanets

Posted by in categories: chemistry, space

Scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) to study the protoplanetary disk around a young star have discovered the most compelling chemical evidence to date of the formation of protoplanets. The discovery will provide astronomers with an alternate method for detecting and characterizing protoplanets when direct observations or imaging are not possible. The results will be published in an upcoming edition of The Astrophysical Journal Letters.

HD 169,142 is a young star located in the constellation Sagittarius that is of significant interest to astronomers due to the presence of its large, dust-and gas-rich circumstellar disk that is viewed nearly face-on. Several candidates have been identified over the last decade, and earlier this year, scientists at the University of Liùge and Monash University confirmed that one such candidate—HD 169,142 b—is, in fact, a giant Jupiter-like protoplanet.

The discoveries revealed in a new analysis of archival data from ALMA—an in which the National Science Foundation’s National Radio Astronomy Observatory (NRAO) is a member—may now make it easier for scientists to detect, confirm, and ultimately characterize, protoplanets forming around .

Jun 27, 2023

MIT scientists have found a way to boil water more quickly and efficiently

Posted by in categories: chemistry, energy

What if water could be boiled more quickly and efficiently? It would benefit many industrial processes by reducing energy use, including most electricity generating plants, many chemical production systems, and even cooling systems for electronics.

Improving HTC and CHF

Now, MIT scientists have conceived of a method to do just that, according to a press release by the institution published on Tuesday. The researchers have found a way to improve at the same time the two key parameters that are conducive to the boiling process, the heat transfer coefficient (HTC) and the critical heat flux (CHF).

Jun 26, 2023

A Self-Replicating Radiation-Shield for Human Deep-Space Exploration: Radiotrophic Fungi can Attenuate Ionizing Radiation aboard the International Space Station

Posted by in categories: biotech/medical, chemistry, nuclear energy

The greatest hazard for humans on deep-space exploration missions is radiation. To protect astronauts venturing out beyond Earth’s protective magnetosphere and sustain a permanent presence on Moon and/or Mars, advanced passive radiation protection is highly sought after. Due to the complex nature of space radiation, there is likely no one-size-fits-all solution to this problem, which is further aggravated by up-mass restrictions. In search of innovative radiation-shields, biotechnology holds unique advantages such as suitability for in-situ resource utilization (ISRU), self-regeneration, and adaptability. Certain fungi thrive in high-radiation environments on Earth, such as the contamination radius of the Chernobyl Nuclear Power Plant. Analogous to photosynthesis, these organisms appear to perform radiosynthesis, using pigments known as melanin to convert gamma-radiation into chemical energy. It is hypothesized that these organisms can be employed as a radiation shield to protect other lifeforms. Here, growth of Cladosporium sphaerospermum and its capability to attenuate ionizing radiation, was studied aboard the International Space Station (ISS) over a time of 30 days, as an analog to habitation on the surface of Mars. At full maturity, radiation beneath a ≈ 1.7 mm thick lawn of the melanized radiotrophic fungus (180° protection radius) was 2.17±0.35% lower as compared to the negative control. Estimations based on linear attenuation coefficients indicated that a ~ 21 cm thick layer of this fungus could largely negate the annual dose-equivalent of the radiation environment on the surface of Mars, whereas only ~ 9 cm would be required with an equimolar mixture of melanin and Martian regolith. Compatible with ISRU, such composites are promising as a means to increase radiation shielding while reducing overall up-mass, as is compulsory for future Mars-missions.

The authors have declared no competing interest.

Jun 25, 2023

Major cause of Type 2 diabetes uncovered

Posted by in categories: biotech/medical, chemistry

Oxford Research has reveals how high blood glucose reprograms the metabolism of pancreatic beta-cells in diabetes, acting as a major causal factor of Type 2 diabetes. This is significant because glucose metabolites (chemicals produced when glucose is broken down by cells), rather than glucose itself, have been discovered to be key to the progression of Type 2 diabetes.

With diabetes, the pancreatic beta-cells do not release enough of the hormone insulin, which lowers blood glucose levels. This is because a glucose metabolite damages pancreatic beta-cell function. High blood glucose levels cause an increased rate of glucose metabolism in the beta-cell which leads to a metabolic bottleneck and the pooling of upstream metabolites.

Around 90 percent of global cases of diabetes are Type 2 diabetes (T2D). T2D normally presents in later adult life, and by the time of diagnosis, as much as 50 percent of beta cell function has been lost. In T2D, the beta-cells have a reduced insulin content and the coupling between glucose and insulin release is impaired.

Jun 24, 2023

A new class of interlocking supramolecular systems: MOFaxanes

Posted by in categories: biotech/medical, chemistry

A team of chemists and material scientists at the University of Tokyo has developed a new class of interlocking supramolecular systems by combining metal-organic frameworks with rotaxanes. In their study, reported in the journal Nature Communications, the group combined the two structures and found possible uses for the results.

Metal-organic frameworks (MOFs) are compounds made using in such a way as to create one-, two-, or three-dimensional structures. The resultant ligands are known in the chemistry world as linkers or struts. They are typically used to make products such as sensing equipment, machines that store energy or those that separate and purify liquids. They have also been used for biological imaging and .

Rotaxanes are molecular structures that are interlocked in dumbbell shapes. They are created by threading cyclic molecules into other molecules and then applying end caps. They are typically used as molecular switches in electronics devices, and sometimes as shuttles. In this new effort, the research team developed a way to connect the two types of to create new kinds of interlocking structures.