Comment

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 7:09am

A pocket cooling device based on a cascade mechanism

Recent technological advances have enabled the development of increasingly compact and flexible devices. This includes wearable or portable technology.

Researchers  have recently devised a strategy that could enable the fabrication of portable, compact and flexible electrocaloric cooling devices. This strategy, outlined in a paper published in Nature Energy, is based on a four-layer cascade mechanism that enables a significant temperature lift in a user's surroundings.

This pocket cooling device designed is made of an electrocaloric polymer film. When voltage is applied to the polymer, the device heats up due to a significant entropy reduction. Conversely, when the voltage is removed, the device's temperature drops.

Yuan Meng et al. A cascade electrocaloric cooling device for large temperature lift, Nature Energy (2020). DOI: 10.1038/s41560-020-00715-3

https://techxplore.com/news/2020-11-pocket-cooling-device-based-cas...

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 9:40am

Scientists Detect 'Superbolts' 1,000 Times Brighter Than Typical Lightning Strikes

scientists have just detected a new extreme in hotspots of lightning activity called 'superbolts': intense lightning strikes that shine up to 1,000 times brighter than typical lightning strikes. 

The observations come from researchers at the US Los Alamos National Laboratory, who used satellites to measure the extreme lightning events. The results force a rethink on what constitutes a superbolt, and shed new light on how and where superbolts originate. Unlike ground-based monitoring systems, which detect radio waves, the GLM measures the total brightness (optical energy) of lightning bolts within clouds, between clouds, plus lightning that strikes the ground.

There's also the question of whether superbolts are supercharged by some unique phenomenon, or if they're just bigger, brighter strikes of the usual lightening variety.

Understanding these extreme events is important because it tells us what lightning is capable of.

The researchers combed two years of data for lightning strikes that shone 100 times brighter than a typical bolt detected from space, and found about 2 million events intense enough to be called a superbolt – roughly one in every 300 lightning events. When the researchers raised the bar to lightning events at least 1,000 times brighter than an ordinary lightning strike, they identified key hotspots of energetic superbolt activity.

Scientists found one lightning stroke that exceeded 3 terawatts of power – thousands of times stronger than ordinary lightning detected from space.

The most powerful superbolts (producing more than 350 gigawatts of power) resulted from rare positively charged cloud-to-ground events, rather than negatively charged cloud-to-ground events, which characterises most lightning strikes.

The results also showed that superbolts often occur over the ocean and tend to spark from megaflashes, which stretch hundreds of miles horizontally from tip to tail.

Oceanic storm systems, particularly during the winter, and especially those located around Japan are shown to produce these intense superbolts.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033378

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033377

https://www.sciencealert.com/study-finds-superbolts-shine-1000-time...

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 8:47am

Oxford vaccine: How did they make it so quickly?

Ten years' vaccine work achieved in about 10 months. Yet no corners cut in designing, testing and manufacturing.

https://www.bbc.com/news/health-55041371

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 8:28am

Scientists find water microdroplets can transform into hydrogen peroxide when condensing on cold surfaces

In its bulk liquid form, whether in a bathtub or an ocean, water is a relatively benign substance with little chemical activity. But down at the scale of tiny droplets, water can turn surprisingly reactive,  researchers have discovered.

In microdroplets of water, just millionths of a meter wide, a portion of the H₂O molecules present can convert into a close chemical cousin, hydrogen peroxide, H₂O₂, a harsh chemical commonly used as a disinfectant and hair bleaching agent.

Stanford scientists first reported this unexpected behavior in forcibly sprayed microdroplets of water last year. Now in a new study, the research team has shown the same Jekyll-and-Hyde transformation happens when microdroplets simply condense from the air onto cold surfaces. The new results suggest that water's hydrogen peroxidetransformation is a general phenomenon, occurring in fogs, mists, raindrops and wherever else microdroplets form naturally.

The surprising discovery could lead to greener methods for disinfecting surfaces or promoting chemical reactions.

Jae Kyoo Lee et al. Condensing water vapor to droplets generates hydrogen peroxide, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2020158117

https://phys.org/news/2020-11-scientists-microdroplets-hydrogen-per...

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 7:41am

COVID-19: Air quality influences the pandemic

The correlation between the high concentration of fine particles and the severity of influenza waves is well known to epidemiologists. An interdisciplinary team from the University of Geneva (UNIGE) and the ETH Zürich spin-off Meteodat investigated possible interactions between acutely elevated levels of fine particulate matter and the virulence of the coronavirus disease. Their results, published in the journal Earth Systems and Environment, suggest that high concentrations of particles less than 2.5 micrometers in size may modulate, or even amplify, the waves of SARS-CoV-2 contamination and explain in part the particular profile of the COVID-19 pandemic. The increase in fine particles is generally favored by air temperature inversions, characterized by fog situations, or by Saharan dust intrusions. The study provides preventive measures related to air pollution to limit future outbreaks of morbidity and mortality due to the coronavirus.

--

India's love affair with coal cools as pressure grows on sector

Funding for coal projects in India has plunged for the second straight year, new figures showed Tuesday, as the world's second biggest coal importer weans itself off the dirty fuel.

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 7:28am

Antimicrobial soap additive worsens fatty liver disease in mice

Researchers found evidence that triclosan—an antimicrobial found in many soaps, toothpastes and other household items—worsens fatty liver disease in mice fed a high-fat diet.

The study also reveals also details the molecular mechanisms  by which triclosan disrupts metabolism and the gut microbiome, while also stripping away liver cells' natural protections. Triclosan's increasingly broad use in consumer products presents a risk of liver toxicity for humans.

The study shows that common factors that we encounter in every-day life—the ubiquitous presence of triclosan, together with the prevalence of high consumption of dietary fat —constitute a good recipe for the development of fatty liver disease in mice.

In a 2014 mouse study, the team found triclosan exposure promoted liver tumor formation by interfering with a protein responsible for clearing away foreign chemicals in the body. In the latest study, the researchers fed a high-fat diet to mice with type 1 diabetes. As previous studies have shown, the high-fat diet led to non-alcoholic fatty liver disease (NAFLD). In humans, NAFLD is an increasingly common condition that can lead to liver cirrhosis and cancer. Diabetes and obesity are risk factors for NAFLD. Some of the mice were also fed triclosan, resulting in blood concentrations comparable to those found in human studies. Compared to mice only fed a high-fat diet, triclosan accelerated the development of fatty liver and fibrosis. According to the study, here's what's likely happening: Eating a high-fat diet normally tells cells to produce more fibroblast growth factor 21, which helps protects liver cells from damage. Tukey and team discovered that triclosan messes with two molecules, ATF4 and PPARgamma, which cells need to make the protective growth factor. Not only that, the antimicrobial also disrupted a variety of genes involved in metabolism. In addition, the mice exposed to triclosan had less diversity in their gut microbiomes—fewer types of bacteria living in the intestines, and a makeup similar to that seen in patients with NAFLD. Less gut microbiome diversity is generally associated with poorer health. So far, these findings have only been observed in mice who ingested triclosan. But since these same molecular systems also operate in humans, the new information will help researchers better understand risk factors for NAFLD, and give them a new place to start in designing potential interventions to prevent and mitigate the condition.

Mei-Fei Yueh et al, Triclosan leads to dysregulation of the metabolic regulator FGF21 exacerbating high fat diet-induced nonalcoholic fatty liver disease, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2017129117

https://medicalxpress.com/news/2020-11-antimicrobial-soap-additive-...

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 6:52am

**Cocoa flavanols boost brain oxygenation, cognition in healthy adults

The brains of healthy adults recovered faster from a mild vascular challenge and performed better on complex tests if the participants consumed cocoa flavanols beforehand, researchers report in the journal Scientific Reports. In the study, 14 of 18 participants saw these improvements after ingesting the flavanols.

Previous studies have shown that eating foods rich in flavanols can benefit vascular function, but this is the first to find a positive effect on brain vascular function and cognitive performance in young healthy adults.

Flavanols are small molecules found in many fruits and vegetables, and cocoa, too. They give fruits and vegetables their bright colours, and they are known to benefit vascular function.

About two hours after consuming the cocoa, participants breathed air with 5% carbon dioxide—about 100 times the normal concentration in air. This is a standard method for challenging brain vasculature to determine how well it responds.

Researchers also challenged participants with complex tasks that required them to manage sometimes contradictory or competing demands.

Most of the participants had a stronger and faster brain oxygenation response after exposure to cocoa flavanols than they did at baseline or after consuming cocoa lacking flavanols, the researchers found. 

After ingesting the cocoa flavanols, participants also performed better on the most challenging cognitive tests, correctly solving problems 11% faster than they did at baseline or when they consumed cocoa with reduced flavanols. There was no measurable difference in performance on the easier tasks, however.

"This suggests that flavanols might only be beneficial during cognitive tasks that are more challenging.

'Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults,' Scientific Reports (2020). DOI: 10.1038/s41598-020-76160-9

https://medicalxpress.com/news/2020-11-cocoa-smarter.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on November 24, 2020 at 11:52am

Deep learning helps robots grasp better

Comment by Dr. Krishna Kumari Challa on November 24, 2020 at 11:48am

Energy drinks can raise stillbirth risk and caffeine guidance confuses mums-to-be, new research warns

Stillbirth experts warn that expectant parents need to know more about caffeine, as a new study from Tommy’s Maternal and Fetal Health Research Centre at the university of Manchester shows 1 in 20 women increased their intake during pregnancy, despite evidence that some caffeinated drinks can endanger babies’ lives.

Scientists from Tommy’s stillbirth research centre at the University of Manchester studied more than 1,000 mothers across 41 UK hospitals between 2014 and 2016. They combined information typically used to measure stillbirth risk with an interviewer-led questionnaire about mothers’ consumption of various caffeinated drinks, as well as other risk factors like alcohol and cigarettes that have confused previous studies, to see if and when stillbirth may have been linked to caffeine.

When caffeine crosses the placenta, babies can’t process it like adults, and it can endanger their lives. Current NHS guidance is to keep daily caffeine intake below 200mg when pregnant, while the World Health Organization (WHO) cites 300mg as the safe limit. This new study reports a 27% increase in stillbirth risk for each 100mg consumed, suggesting that safe limits in these guidelines need to be reconsidered.

Energy drinks had the most impact, leading to 1.85x higher stillbirth risk, followed by instant coffee (1.34x) and cola (1.23x). Researchers noted that it wasn’t possible to separate the impact of caffeine from that of sugar in cola and chemicals like taurine in energy drinks, so more detailed investigation is needed.

https://www.manchester.ac.uk/discover/news/energy-drinks-can-raise-...

https://researchnews.cc/news/3734/Energy-drinks-can-raise-stillbirt...

Comment by Dr. Krishna Kumari Challa on November 24, 2020 at 11:17am

**Choked, strangled and drowned. How balloons and plastic bags are killing marine animals

Balloons, plastic bags, recreational fishing line and food wrappers are killing thousands of marine animals as they eat plastic items that later perforate internal organs, or become entangled and drown.

Researchers found that plastics ranged in size and type, from microplastics that were perforating the gastrointestinal tract of a baby sea turtle to DVD cases and huge plastic sheets that had been swallowed by whales.

Scientists estimate that 15 million tons of plastic wash into the ocean every year, or about two garbage trucks' worth of plastic every minute. With plastic production expected to quadruple by the year 2050, some expect there will be more plastic than fish in the world's oceans.

The biggest problem was animals consuming plastic. Marine animals often mistake plastic for food or inadvertently swallow plastic while feeding or swimming.

"The result is that it can obstruct their digestion or lacerate their intestines, and all of this can interfere with their ability to feed and obtain the nourishment they need. These problems can lead to an animal's starvation and death.

https://phys.org/news/2020-11-strangled-balloons-plastic-bags-marin...

• ‹ Previous
• 1
• …
• 747
• 748
• 749
• 750
• 751
• …
• 1112
• Next ›
• Page