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Comment by Dr. Krishna Kumari Challa on May 13, 2021 at 11:38am

Higher antibiotic doses may make bacteria 'fitter': study

Using higher doses of antibiotics in a bid to tackle the growing problem of drug resistance may end up strengthening certain bacteria, according to research released recently that highlights a previously unthought-of risk.

Previous research has shown that inflicting higher antibiotic doses on bacteria can slow its ability to develop resistance, yet little attention has been paid to how those higher doses impact the overall health of microbes.

A team of Britain- and Europe-based researchers looked at how populations of E. coli reacted to varying concentrations of three common antibiotics.

They found that while higher antibiotic doses slowed the rate at which the bacteria developed resistance, they also gave rise to bacteria with "higher overall fitness"—meaning it had a higher rate of reproduction.

"We consider growth rate as a proxy for fitness, under the assumption that a strain that grows faster is more likely to take over the population and become dominant.

This 

showed how higher antibiotic doses presented a "dilemma" and could result in ultimately more-resistant bacteria.

Considering the fitness of the evolved strains adds another dimension to the problem of optimal antibiotic dosing.

Mato Lagator et al. Adaptation at different points along antibiotic concentration gradients, Biology Letters (2021). DOI: 10.1098/rsbl.2020.0913

https://phys.org/news/2021-05-higher-antibiotic-doses-bacteria-fitt...

Comment by Dr. Krishna Kumari Challa on May 13, 2021 at 11:28am

Brand new physics of superconducting metals refuted by Lancaster physicists

Lancaster scientists have demonstrated that other physicists' recent "discovery" of the field effect in superconductors is nothing but hot electrons after all.

A team of scientists in the Lancaster Physics Department have found new and compelling evidence that the observation of the field effect in superconducting metals by another group can be explained by a simple mechanism involving the injection of the electrons, without the need for novel physics.

Dr. Sergey Kafanov, who initiated this experiment, said: "Our results unambiguously refute the claim of the electrostatic field effect claimed by the other group. This gets us back on the ground and helps maintain the health of the discipline."

The experimental team also includes Ilia Golokolenov, Andrew Guthrie, Yuri Pashkin and Viktor Tsepelin.

Their work is published in the latest issue of Nature Communications.

When certain metals are cooled to a few degrees above absolute zero, their electrical resistance vanishes—a striking physical phenomenon known as superconductivity. Many metals, including vanadium, which was used in the experiment, are known to exhibit superconductivity at sufficiently low temperatures.

For decades it was thought that the exceptionally low electrical resistance of superconductors should make them practically impervious to static electric fields, owing to the way the charge carriers can easily arrange themselves to compensate for any external field.

It therefore came as a shock to the physics community when a number of recent publications claimed that sufficiently strong electrostatic fields could affect superconductors in nanoscale structures—and attempted to explain this new effect with corresponding new physics. A related effect is well known in semiconductors and underpins the entire semiconductor industry.

The Lancaster team embedded a similar nanoscale device into a microwave cavity, allowing them to study the alleged electrostatic phenomenon at much shorter timescales than previously investigated. At short timescales, the team could see a clear increase in the noise and energy loss in the cavity—the properties strongly associated with the device temperature. They propose that at intense electric fields, high-energy electrons can "jump" into the superconductor, raising the temperature and therefore increasing the dissipation.

This simple phenomenon can concisely explain the origin of the "electrostatic field effect" in nanoscale structures, without any new physics.

Nature Communications (2021). DOI: 10.1038/s41467-021-22998-0

https://phys.org/news/2021-05-brand-physics-superconducting-metals-...

Comment by Dr. Krishna Kumari Challa on May 13, 2021 at 11:15am

How fasting diets could harm future generations

Fasting diets could impact the health of future generations according to new research .

Fasting diets have risen in popularity in recent years, however little is known about the long-term impact of these diets, particularly for future generations.

New research, published today in the journal Proceedings of the Royal Society B, reveals that reduced food intake in roundworms (Caenorhabditis elegans) has a detrimental effect on three generations of offspring—particularly when those descendants have access to unlimited food.

We know that reduced food intake increases the lifespan in many animals and can potentially improve health in humans. However, little is known about the long-term effects of reduced food intake, including time-limited fasting, on distant descendants.

The team investigated the effect of time-limited fasting on lifespan and reproduction in roundworms and across three generations of their descendants.

They studied more than 2,500 worms split across four generations. The first generation of worms were placed in one of four environments, including being able to eat as much as they liked, and being on a fasting diet.

Four generations of offspring from these parents were then placed onto either full-feeding or fasting diets.

The team then assessed the effects of different scenarios on the reproduction and longevity of future generations. These included what happens when great grandparents fast, but future generations are able to eat as much as they like, and cumulative fasting for four generations.

fasting did indeed increase their lifespan and it also improved offspring performance in terms of reproduction, when offspring themselves were fasting.

"However, we were surprised to find that fasting reduced offspring performance when the offspring had access to unlimited food.

"And this detrimental effect was evident in grand-offspring and great-grand-offspring.

This shows that fasting can be costly for descendants and this effect may last for generations.

"There has been a lot of interest in the potential benefits of fasting in promoting healthy aging in humans.

"A lot of the molecular pathways involved in the fasting response are evolutionarily conserved, which means the same pathways exist across a multitude of species including humans.

This study strongly prompts us to consider multigenerational effects of fasting in different organisms, including humans.

Edward R. Ivimey-Cook et al. Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans, Proceedings of the Royal Society B (2020). DOI: 10.1101/2020.06.24.168922

https://medicalxpress.com/news/2021-05-fasting-diets-future.html?ut...

Comment by Dr. Krishna Kumari Challa on May 13, 2021 at 10:08am

How to thermally cloak an object

Do you feel the heat? To a thermal camera, which measures infrared radiation, the heat that we can feel is visible, like the heat of a traveler in an airport with a fever or the cold of a leaky window or door in the winter.

Researchers now report a theoretical way of mimicking thermal objects or making objects invisible to thermal measurements. 

The method allows for fine-tuning of heat transfer even in situations where the temperature changes in time, the researchers say. One application could be to isolate a part that generates heat in a circuit (say, a power supply) to keep it from interfering with heat sensitive parts (say, a thermal camera). Another application could be in industrial processes that require accurate temperature control in both time and space, for example controlling the cooling of a material so that it crystallizes in a particular manner.

Just as our eyes see objects if they emit or reflect light, a thermal camera can see an object if it emits or reflects infrared radiation. In mathematical terms, an object could become invisible to a thermal camera if heat sources placed around it could mimic heat transfer as if the object wasn't there.

The novelty in the team's approach is that they use heat pumps rather than specially crafted materials to hide the objects. A simple household example of a heat pump is a refrigerator: to cool groceries it pumps heat from the interior to the exterior. Using heat pumps is much more flexible than using carefully crafted materials. So at least from the perspective of thermal measurements they can make an apple appear as an orange.

The researchers carried out the mathematical work needed to show that, with a ring of heat pumps around an object, it's possible to thermally hide an object or mimic the heat signature of a different object.

The work remains theoretical

Active Thermal Cloaking and Mimicking, Proceedings of the Royal Society A (2021). royalsocietypublishing.org/doi … .1098/rspa.2020.0941

https://phys.org/news/2021-05-thermally-cloak.html?utm_source=nwlet...

Comment by Dr. Krishna Kumari Challa on May 12, 2021 at 1:23pm

Potentially Deadly 'Black Fungus' Keeps Showing Up in COVID-19 Patients in India

Potentially fatal 'black fungus' infections on the rise in India's COVID-19 patients

Some COVID-19 patients in India have developed a rare and potentially fatal fungal infection called mucormycosis, also known as "black fungus," according to news reports.

Mucormycosis is caused by a group of molds called mucormycetes, which grow in soil and decaying organic matter, such as rotting leaves and wood. It is ubiquitous and found in soil and air and even in the nose and mucus of healthy people.

The mold can enter the body through cuts and other abrasions in the skin, or the infection can take hold in the sinuses or lungs after people breathe in the fungal spores. Once inside the body, the fungus can sometimes spread through the bloodstream and affect other organs, such as the brain, eyes, spleen and heart.

Most commonly, mucormycosis strikes those with weakened immune systems, including those with diabetes and those taking medicines that suppress immune activity. Now, an increasing number of COVID-19 patients in India appear to be contracting the infection. 

Cases are appearing throughout India now. 

The rise in cases may be connected to the use of steroids in hospitalized COVID-19 patients, since the drugs suppress the immune system.

And those with diabetes start out at increased risk for the infection, even before taking steroids.

"Diabetes lowers the body's immune defenses, coronavirus exacerbates it, and then steroids which help fight COVID-19 act like fuel to the fire. In addition, many families have had to treat relatives for COVID-19 at home, meaning people may become exposed to the mold after receiving medicine or oxygen therapy in less-than-sterile conditions.

https://www.livescience.com/black-fungus-infection-coronavirus-indi...

Comment by Dr. Krishna Kumari Challa on May 12, 2021 at 1:10pm

SARS-CoV-2 coronavirus spike protein under siege

This is video of a SARS-CoV-2 spike protein under siege. The little blobs buzzing around it are called lectins, and they could be the secret weapon in a new defence against COVID-19, new research has found. 

--

Most COVID-19 drugs currently in clinical trials are designed to block receptor sites on our cells -- the little doors on the surface of our cells that the SARS-CoV-2 spike protein breaches to gain access. But this treatment would be different, targeting the spike protein itself. The protein hides from our immune system by covering itself with sugar molecules called glycans. These glycans are a disguise that helps the virus get in the door. What if, instead of trying to block the door, you gummed up the key instead?

Researchers developed the largest lectin library in the world to find two lectins that are particularly good at binding to glycans on the SARS-CoV-2 spike protein. These lectins are the gum on the key, and could be the starting point for a lectin-based drug to combat COVID-19. The best part? The glycan sites that the spike protein uses for its disguise show up in all circulating variants of the SARS-CoV-2 virus.

Not only have the researchers learned how these lectins bind to the spike protein, they've recorded it happening.

https://www.biorxiv.org/content/10.11...

Comment by Dr. Krishna Kumari Challa on May 12, 2021 at 11:50am

New material to treat wounds can protect against resistant bacteria

Researchers at Chalmers University of Technology, Sweden, have developed a new material that prevents infections in wounds, a specially designed hydrogel that works against all types of bacteria, including antibiotic-resistant strains. The new material offers great hope for combating a growing global problem.

After testing the new hydrogel on different types of bacteria, researchers observed a high level of effectiveness, including against those which have become resistant to antibiotics.

The active substance in the new bactericidal material consists of antimicrobial peptides, small proteins found naturally in the immune system.

"With these types of peptides, there is a very low risk for bacteria to develop resistance against them, since they only affect the outermost membrane of the bacteria. That is perhaps the foremost reason why they are so interesting.

Researchers have long tried to find ways to use these peptides in medical applications, but so far without much success. The problem is that they break down quickly when they come into contact with bodily fluids such as blood. The current study describes how the researchers managed to overcome the problem through the development of a nanostructured hydrogel, into which the peptides are permanently bound, creating a protective environment.

Saba Atefyekta et al, Antimicrobial Peptide-Functionalized Mesoporous Hydrogels, ACS Biomaterials Science & Engineering (2021). DOI: 10.1021/acsbiomaterials.1c00029

https://phys.org/news/2021-05-material-wounds-resistant-bacteria.ht...

Comment by Dr. Krishna Kumari Challa on May 12, 2021 at 11:07am

Estimation of total mortality due to COVID-19

A team of researchers at the University of Washington Institute for Health Metrics and Evaluation (IHME) has found evidence that suggests the number of people who have died due to COVID-19 is much higher than official reports would indicate. They have undertaken a country-by-country analysis of deaths due to COVID-19 that includes factors associated with the pandemic as a whole and have published their results on the IHME website.

Scientists have calculated total number of people died due to covid:

 By May 3, 2021, the total number of COVID-19 deaths in the world was 6.93 million, a figure that is more than two times higher than the reported number of deaths of 3.24 million.

India: Total number of people actually died due to copvid-19: 6,54,935

Reported deaths: 2, 21,181

Source: http://www.healthdata.org/special-analysis/estimation-excess-mortal...

Comment by Dr. Krishna Kumari Challa on May 12, 2021 at 10:01am

Scientists catch exciting magnetic waves in action in the Sun's photosphere

Researchers have confirmed the existence of magnetic plasma waves, known as Alfvén waves, in the Sun's photosphere. The study, published in Nature Astronomy, provides new insights into these fascinating waves that were first discovered by the Nobel Prize winning scientist Hannes Alfvén in 1947.

The vast potential of these waves resides in their ability to transport energy and information over very large distances due to their purely magnetic nature. The direct discovery of these waves in the solar photosphere, the lowest layer of the solar atmosphere, is the first step towards exploiting the properties of these magnetic waves.

The ability for Alfvén waves to carry energy is also of interest for solar and plasma-astrophysics as it could help explain the extreme heating of the solar atmosphere—a mystery that has been unsolved for over a century.

Alfvén waves form when charged particles (ions) oscillate in response to interactions between magnetic fields and electrical currents.

Within the solar atmosphere bundles of magnetic fields, known as solar magnetic flux tubes, can form. Alfvén waves are though to manifest in one of two forms in solar magnetic flux tubes; either axisymmetric torsional pertubations (where symmetric oscillations occur around the flux tube axis) or anti-symmetric torsional pertubations (where oscillations occur as two swirls rotating in opposite directions in the flux tube).

Despite previous claims, torsional Alfvén waves have never been directly identified in the solar photosphere, even in their simplest form of axisymmetric oscillations of magnetic flux tubes.

In this study, the researchers used high resolution observations of the solar atmosphere, made by the European Space Agency's imager IBIS, to prove the existence of anti-symmetric torsional waves first predicted almost 50 years ago.

They also found that these waves could be used to extract vast amounts of energy from the solar photosphere, confirming the potential of these waves for a wide range of research areas and industrial applications.

Marco Stangalini et al. Torsional oscillations within a magnetic pore in the solar photosphere, Nature Astronomy (2021). DOI: 10.1038/s41550-021-01354-8

https://phys.org/news/2021-05-scientists-magnetic-action-sun-photos...

Comment by Dr. Krishna Kumari Challa on May 11, 2021 at 12:31pm

Targeting viral RNA: The basis for next-gen broad spectrum anti-viral drugs

A new approach to tackling viruses by targeting the 'control center' in viral RNA could lead to broad spectrum anti-viral drugs and provide a first line of defense against future pandemics, according to new research.

In a new study, published in Angewandte Chemie, researchers have shown how this approach could be effective against the SARS-CoV-2 virus responsible for the COVID-19 pandemic. Earlier modeling and in vitro analysis by the team and published in Chemical Science has also shown effectiveness against the HIV virus.

The technique proposed by the team uses cylindrically-shaped molecules which can block the function of a particular section at one end of the RNA strand. These RNA sections, known as untranslated RNA, are essential for regulating the replication of the virus.

Untranslated RNA contain junction points and bulges—essentially small holes in the structure– which are normally recognized by proteins or other pieces of RNA—events that are critical for viral replication to occur. The cylindrical molecules are attracted to these holes, and once they slide into them, the RNA closes around them, forming a precise fit, which consequently will interfere with the virus's ability to replicate.

Lazaros Melidis et al. Supramolecular cylinders target bulge structures in the 5' UTR of the RNA genome of SARS‐CoV‐2 and inhibit viral replication, Angewandte Chemie (2021). DOI: 10.1002/ange.202104179

Lazaros Melidis et al. Targeting structural features of viral genomes with a nano-sized supramolecular drug, Chemical Science (2021). DOI: 10.1039/D1SC00933H

https://phys.org/news/2021-05-viral-rna-basis-next-gen-broad.html?u...

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