Scientists discover new family of quasiparticles in graphene-based materials

A group of researchers have discovered and characterized a new family of quasiparticles named 'Brown-Zak fermions' in graphene-based superlattices.

The team achieved this breakthrough by aligning the atomic lattice of a graphene layer to that of an insulating boron nitride sheet, dramatically changing the properties of the graphene sheet.

In a graphene layer which has been aligned with the boron nitride, electrons also start to bend—but if you set the magnetic field at specific values, the electrons move in straight line trajectories again, as if there is no magnetic field anymore! Such behaviour is radically different from textbook physics.

Researchers attribute this fascinating behaviour to the formation of novel quasiparticles at high magnetic field. Those quasiparticles have their own unique properties and exceptionally high mobility despite the extremely high magnetic field.

Nature Communications (2020). DOI: 10.1038/s41467-020-19604-0

https://phys.org/news/2020-11-scientists-family-quasiparticles-grap...

Microbes feeding on methane release arsenic into groundwater

Arsenic is a toxin now widely present in rivers and groundwater in countries such as Bangladesh and Vietnam. It is released by the activity of microorganisms. Yet for a long time it was unclear what the microorganisms ate to release the arsenic. A team of geomicrobiologists led by Professor Andreas Kappler from the University of Tübingen has shown that the microbes break down arsenic-bearing sediments using organic compounds from deep layers as food, disproving theories that the fuel for their activity was drawn from plants or algae on the surface. Now the team has also shown that along with the organic materials in the sediments, methane gas is an important source of food for the bacteria and also plays a key role in their release of arsenic. This new mechanism responsible for arsenic mobilization can explain elevated concentration of arsenic in many aquifers and will help to more precisely predict future drinking water contamination.

 Arsenic mobilization by anaerobic iron-dependent methane oxidation, Nature Communications Earth & Environment (2020). DOI: 10.1038/s43247-020-00037-y

https://phys.org/news/2020-11-microbes-methane-arsenic-groundwater....

Organoids produce embryonic heart

 stem cell biology and tissue engineering are turning fiction into reality with the advent of organoids: tiny lab-grown tissues and organs that are anatomically correct and physiologically functional.

The appeal of organoids is obvious. Essentially, they can provide us with an on-demand production of tissues and mini-organs for pharmaceutical and medical research, without constantly having to rely on donors. And although that goal might still be a long way off, we’re slowly getting closer.

Now, researchers have successfully produced a mouse heart organoid in its early embryonic stages.  The researchers grew their organoids from mouse embryonic stem cells, which, under the right conditions, can self-organize into structures that “mimic aspects of the architecture, cellular composition, and function of tissues found in real organs”. Placed in cell-culture under specific conditions, the embryonic stem cells form a three-dimensional aggregate called a “gastruloid”, which can follow the developmental stages of the mouse embryo.

Armed with this, the researchers exposed mouse embryonic stem cells to a “cocktail” of three factors known to promote heart growth. After 168 hours, the resulting gastruloids showed signs of early heart development: they expressed several genes that regulate cardiovascular development in the embryo, and they even generated what resembled a vascular network.

But more importantly, the researchers found that the gastruloids developed what they call an “anterior cardiac crescent-like domain”. This structure produced a beating heart tissue, similar to the embryonic heart. And much like the muscle cells of the embryonic heart, the beating compartment was also sensitive to calcium ions.

https://actu.epfl.ch/news/organoids-produce-embryonic-heart/

https://researchnews.cc/news/3583/Organoids-produce-embryonic-heart...

Anti-ageing therapy against metastases

Scientists discovered a genetic factor that determines whether ageing prostate cancer cells either die or become more aggressive. This finding provides important information for personalised therapy of patients.

Aging tumour cells stop proliferating. This cell ageing process is called senescence. In cancer therapy, it is deliberately induced with drugs to slow down tumour growth. However, such senescent tumour cells can, in certain conditions, also take the opposite path, which is undesirable in therapy: they become more aggressive and form metastases.

An international team of researchers was studying the senescence processes in prostate cancer. They have now found the genetic switch that determines the fate of senescent cells: the gene TIMP1. If this gene is inactive or absent in patients, factors are released in the tumour cell which reprogramme the cell and make it more aggressive and invasive.

Based on clinical data and genetic studies of prostate cancer patients, the scientists were also able to show that an inactive TIMP1 gene frequently occurs and correlates with lack of responsiveness to chemotherapy and a more severe clinical outcome.

The results of this research once again direct us towards personalised cancer therapy. Genetic factors of the patient can in fact determine whether senescence has a positive effect on tumour growth or a negative effect in stimulating the formation of metastases. In the latter case it is important to administer chemotherapeutic drug that induce senescence with caution. Instead, senolytic drugs that kill the senescent cells should be administered.

https://ethz.ch/en/news-and-events/eth-news/news/2020/11/anti-agein...

https://researchnews.cc/news/3571/Anti-ageing-therapy-against-metas...

Rosetta Comet Mission 

How to make a fake supernova

Powerful, mysterious stellar explosions are difficult to understand from afar, so researchers have figured out how to re-create supernovas' extreme physics in the lab and study how outbursts seed the cosmos with elements and energetic particles.

Compounds block stress-enhanced nicotine intake in rats
Stress is a major cause of relapse after people quit smoking. Worrying situations, such as money or relationship problems, can affect neurotransmitter levels in the brain, leading former smokers to reach for a cigarette. Now, researchers reporting in ACS Pharmacology & Translational Science have discovered that compounds that activate γ-aminobutyric acid (GABA) receptors in the brain can keep rats from self-administering increased levels of nicotine during stressful conditions in an animal model for relapse.

GABA is an inhibitory neurotransmitter that decreases nerve signaling in the brain. When a person experiences stress, their GABA levels can decrease, causing some neurons to become hyperactive. Using an animal model, Burt Sharp and colleagues wanted to find out if giving rats compounds that stimulate GABAA, a specific type of GABA receptor, on certain neurons, called basolateral amygdala principal output neurons, could lessen the rats’ relapse to nicotine during stressful conditions.

In the animal model, rats were taught to press a lever to self-administer nicotine. After a week, the animals were withdrawn from nicotine for 8 days. To cause stress, the researchers confined the rats in a small space. After releasing the rodents, the team injected one of three compounds, called positive allosteric modulators of GABAA, or PAMs, into a specific region of the stressed rats’ brains, and then gave them access to the nicotine-administering levers. Untreated stressed rats pressed the levers about 1.5 times more frequently than they had before the abstinence period, while rats treated with any of the PAMs reduced nicotine intake to levels seen in unstressed rats before the abstinence period. If similar effects are confirmed in humans, novel, selective PAMs could be helpful in alleviating the stress-induced relapse to smoked tobacco, with potentially fewer side effects than GABA administration, the researchers say.
https://www.acs.org/content/acs/en/pressroom/presspacs/2020/acs-pre...
https://researchnews.cc/news/3588/Compounds-block-stress-enhanced-n...

Diagnostic imaging may increase risk of testicular cancer

Early and repeated exposures to diagnostic imaging, such as X-rays and CT scans, may increase the risk of testicular cancer, suggests a new study from Penn Medicine researchers published online in PLOS ONE. “The steady rise in testicular germ cell tumor (TGCT) cases over the past three or four decades suggests there is an environmental exposure risk at play, but no definitive risk factor has ever been identified.

The data suggests that the increased use of diagnostic radiation below the waist in men over that same time may contribute to the increase in incidence.

In this latest research, the authors conducted an observational study of 1,246 men between the ages of 18 and 55 with and without testicular cancer at Penn Medicine. The participants were invited to complete a questionnaire that elicited information on known and presumptive risk factors for testicular cancer and diagnostic imaging during their lifetime, including location on the body and number of exposures, prior to their diagnosis. Tumor samples were also collected.

After adjusting for known risks of testicular cancer, including cryptorchidism and family history, race, age, and other factors, the researchers found that there was a statistically significant increased risk of testicular cancer among those reporting at least three exposures to X-ray, including a colon X-ray, and CT below the waist, compared to men with no such exposure.

Individuals with three or more exposures to diagnostic radiation had a 59 percent increased risk of having TGCT compared to individuals with no exposures to diagnostic radiation. The risk was also elevated for those exposed to diagnostic radiation during the first decade of their life, compared to those first exposed at age 18 years or later.

https://www.pennmedicine.org/news/news-releases/2020/november/diagn....

https://researchnews.cc/news/3586/Diagnostic-imaging-may-increase-r...

Building blocks of life can form long before stars

An international team of scientists have shown that glycine, the simplest amino acid and an important building block of life, can form under the harsh conditions that govern chemistry in space.

The results, published in Nature Astronomy, suggest that glycine, and very likely other amino acids, form in dense interstellar clouds well before they transform into new stars and planets.

Comets are the most pristine material in our Solar System and reflect the molecular composition present at the time our Sun and planets were just about to form. The detection of glycine in the coma of comet 67P/Churyumov-Gerasimenko and in samples returned to Earth from the Stardust mission suggests that amino acids, such as glycine, form long before stars. However until recently, it was thought that glycine formation required energy, setting clear constraints to the environment in which it can be formed.

In the new study the international team of astrophysicists and astrochemical modelers have shown that it is possible for glycine to form on the surface of icy dust grains, in the absence of energy, through 'dark chemistry'. The findings contradict previous studies that have suggested UV radiation was required to produce this molecule.

Dark chemistry refers to chemistry without the need of energetic radiation. In the laboratory researchers were able to simulate the conditions in dark interstellar clouds where cold dust particles are covered by thin layers of ice and subsequently processed by impacting atoms causing precursor species to fragment and reactive intermediates to recombine.

The scientists first showed methylamine, the precursor species of glycine that was detected in the coma of the comet 67P, could form. Then, using a unique ultra-high vacuum setup, equipped with a series of atomic beam lines and accurate diagnostic tools, they were able to confirm glycine could also be formed, and that the presence of water ice was essential in this process.

Further investigation using astrochemical models confirmed the experimental results and allowed the researchers to extrapolate data obtained on a typical laboratory timescale of just one day to interstellar conditions, bridging millions of years.

Once formed, glycine can also become a precursor to other complex organic molecules . Following the same mechanism, in principle, other functional groups can be added to the glycine backbone, resulting in the formation of other amino acids, such as alanine and serine in dark clouds in space. In the end, this enriched organic molecular inventory is included in celestial bodies, like comets, and delivered to young planets, as happened to our Earth and many other planets.

A non-energetic mechanism for glycine formation in the interstellar medium, Nature Astronomy (2020). DOI: 10.1038/s41550-020-01249-0 , www.nature.com/articles/s41550-020-01249-0

https://phys.org/news/2020-11-blocks-life-stars.html?utm_source=nwl...

Fish carcasses deliver toxic mercury pollution to the deepest ocean trenches

The sinking carcasses of fish from near-surface waters deliver toxic mercury pollution to the most remote and inaccessible parts of the world's oceans, including the deepest spot of them all: the 36,000-foot-deep Mariana Trench in the northwest Pacific.

And most of that mercury began its long journey to the deep-sea trenches as atmospheric emissions from coal-fired power plants, mining operations, cement factories, incinerators and other human activities.

Joel D. Blum el al., "Mercury isotopes identify near-surface marine mercury in deep-sea trench biota," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2012773117

https://phys.org/news/2020-11-fish-carcasses-toxic-mercury-pollutio...

New technology allows more precise view of the smallest nanoparticles

Current state-of-the-art techniques have clear limitations when it comes to imaging the smallest nanoparticles, making it difficult for researchers to study viruses and other structures at the molecular level.

Scientists from the University of Houston and the University of Texas M.D. Anderson Cancer Center have reported in Nature Communications a new optical imaging technology for nanoscale objects, relying upon unscattered light to detect nanoparticles as small as 25 nanometers in diameter. The technology, known as PANORAMA, uses a glass slide covered with gold nanodiscs, allowing scientists to monitor changes in the transmission of light and determine the target's characteristics.

PANORAMA takes its name from Plasmonic Nano-aperture Label-free Imaging (PlAsmonic NanO-apeRture lAbel-free iMAging), signifying the key characteristics of the technology. PANORAMA can be used to detect, count and determine the size of individual dielectric nanoparticles.

Nareg Ohannesian et al. Plasmonic nano-aperture label-free imaging (PANORAMA), Nature Communications (2020). DOI: 10.1038/s41467-020-19678-w

https://phys.org/news/2020-11-technology-precise-view-smallest-nano...

Excess consumption of eggs linked to diabetes

The health benefits of the humble egg might not be all they're cracked up to be as new research from the University of South Australia shows that excess egg consumption can increase your risk of diabetes. It found that people who regularly consumed one or more eggs per day (equivalent to 50 grams) increased their risk of diabetes by 60 percent.

It was discovered  that higher long-term egg consumption (greater than 38 grams per day) increased the risk of diabetes among Chinese adults by approximately 25 percent.

The effect was also more pronounced in women than in men.

Yue Wang et al, Higher egg consumption associated with increased risk of diabetes in Chinese adults – China Health and Nutrition Survey, British Journal of Nutrition (2020). DOI: 10.1017/S0007114520003955

https://medicalxpress.com/news/2020-11-easy-eggs-egg-cess-consumpti...

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Baking Soda Boosts T Cells’ Ability to Fight Leukemia

 Math shows diverse thinkers equal better results

The exchange of information is key in making everyday decisions. But new  research shows that the group decision-making process may work best when members process information a bit differently.

Researchers published a new study today that tackles how groups make decisions and the dynamics that make for fast and accurate decision making. They found that networks that consisted of both impulsive and deliberate individuals made, on average, quicker and better decisions than a group with homogenous thinkers.

Bhargav Karamched et al. Heterogeneity Improves Speed and Accuracy in Social Networks, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.125.218302

https://phys.org/news/2020-11-decision-math-diverse-thinkers-equal....

New optical method paves way to breath test for cancer biomarker

Researchers have developed an extremely sensitive, yet simple optical method for detecting formaldehyde in a person's breath. Because formaldehyde is being studied as a potential biomarker for lung and breast cancer, the new method could one day lead to an inexpensive and fast way to screen for cancer.

Measuring biomarkers in exhaled breath is noninvasive, painless and fast and could be used to screen for cancer even at very early disease stages, which is crucial for successful treatment.

This new optical sensing method based on multipass spectroscopy can detect the presence of 1 molecule of formaldehyde in a million air particles, or 1 part per million, even in the presence of gasses that can interfere with optical measurement.

Mateusz Winkowski et al, Optical detection of formaldehyde in air in the 36 µm range, Biomedical Optics Express (2020). DOI: 10.1364/BOE.405384

https://phys.org/news/2020-11-optical-method-paves-cancer-biomarker...

Cancer researchers discover new human salivary glands

Scientists Discover New Human Salivary Glands

The findings may have implications for radiotherapy, a cancer treatment that can cause damage to salivary glands and leave lasting complications.

https://www.the-scientist.com/news-opinion/scientists-discover-new-...

New study could help predict which individuals are more susceptible to cancer-causing agents

New insights into the mechanisms behind how cancer-causing agents in the environment activate genetic recombination in DNA could help to explain some of the effects of exposure as well as predicting which individuals may be more susceptible to developing the disease, a new study has suggested.

Everyone is exposed to low levels of carcinogens (substances or radiation that promote the formation of cancer) in the environment. One of the most widely found is benzopyrene—a general chemical pollutant found in smoke from stoves such as wood burners, exhaust fumes and barbequed meat and fish. One active ingredient of benzopyrene, BPDE, directly damages the DNA sequence forming what is known as adducts which in turn promote cancer-causing mutations.

While models exist showing how BPDE causes these mutations, some of the pathways are still not understood. It is currently believed that a BPDE adducts cause mutations during DNA synthesis because they activate a process called translesion synthesis—where cells copy the DNA despite the presence of unrepaired damage to allow progression of the replication fork—and this induces mutations. However, evidence also suggests the involvement of another process called homologous recombination (HR) which works by copying other undamaged parts of the genome. HR proteins repair complex DNA damage such as breaks in the DNA strands and interstrand cross-links, and protect and recover stalled or broken replication forks.

This latest study treated human cell lines with BPDE before using molecular biology methods, such as microscopy, to characterize the homologous recombination pathway in detail. Results have offered new insights showing that HR proceeds by an unusual mechanism at BPDE adducts and the process can be activated even when there are no stalled or collapsed replication forks. Instead, it is activated at single-stranded gaps in the DNA that are generated by the re-priming activity of PrimPol—a protein encoded by the PRIMPOL gene in humans.

The findings also address longstanding questions by showing that at bulky DNA adducts, the exchanges between the sister chromatids (the identical copies formed by the DNA replication of a chromosome), products of HR that have been traditionally connected with replication fork collapse and DSB repair, are associated with the repair of post-replicative gaps. Furthermore, these post-replicative gaps are produced by PrimPol, shedding light on the function of PrimPol during DNA damage tolerance.

Ann Liza Piberger, Akhil Bowry, Richard D. W. Kelly, Alexandra K. Walker, Daniel González-Acosta, Laura J. Bailey, Aidan J. Doherty, Juan Méndez, Joanna R. Morris, Helen E. Bryant, Eva Petermann. PrimPol-dependent single-stranded gap formation mediates homologous recombination at bulky DNA adducts. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-19570-7

https://medicalxpress.com/news/2020-11-individuals-susceptible-canc...

Unexpectedly, The Universe Is Getting Hotter And Hotter as It Expands

The Universe is in a state of expansion and  the rate of expansion has been speeding up.

As this progresses, and the galaxy clusters and filaments of the Universe move farther apart, scientists theorize that the mean temperature of the Universe will gradually decline.

But according to new research led by the Center for Cosmology and AstroParticle Physics (CCAPP) at Ohio State University, it appears that the Universe is actually getting hotter as time goes on.

After probing the thermal history of the Universe over the last 10 billion years, the team concluded that the mean temperature of cosmic gas has increased more than 10 times and reached about 2.2 million K (~2.2 °C; 4 million °F) today.

Explanation by scientists for this heating:  As the Universe evolves, gravity pulls dark matter and gas in space together into galaxies and clusters of galaxies. The drag is violent - so violent that more and more gas is shocked and heated up.

https://iopscience.iop.org/article/10.3847/1538-4357/abb403

https://www.sciencealert.com/the-universe-is-getting-hotter-and-hot...

Solar device can sterilize medical tools in off-grid areas without the need for electricity

Autoclaves, the devices used to sterilize medical tools in hospitals, clinics, and doctors' and dentists' offices, require a steady supply of pressurized steam at a temperature of about 125 degrees Celsius. This is usually provided by electrical or fuel-powered boilers, but in many rural areas, especially in the developing world, power can be unreliable or unavailable, and fuel is expensive.

Now, a team of researchers at MIT and the Indian Institute of Technology has come up with a way to generate the needed steam passively, using just the power of sunlight, with no need for fuel or electricity. The device, which would require a solar collector of about 2 square meters (or yards) to power a typical small-clinic autoclave, could maintain safe, sterile equipment at low cost in remote locations. A prototype was successfully tested in Mumbai, India.

The key to the new system is the use of optically transparent aerogel, a material developed over the last few years by Wang and her collaborators. The material is essentially a lightweight foam made of silica, the material of beach sand, and consists mostly of air. Light as it is, the material provides effective thermal insulation, reducing the rate of heat loss by tenfold.

This transparent insulating material is bonded onto the top of what is essentially off-the-shelf equipment for producing solar hot water, which consists of a copper plate with a heat-absorbing black coating, bonded to a set of pipes on the underside. As the sun heats the plate, water flowing through the pipes underneath picks up that heat. But with the addition of the transparent insulating layer on top, plus polished aluminum mirrors on each side of the plate to direct extra sunlight at the plate, the system can generate high-temperature steam instead of just hot water. The system uses gravity to feed water from a tank into the plate; the steam then rises to the top of the enclosure and is fed out through another pipe, which carries the pressurized steam to the autoclave. A steady supply of steam must be maintained for 30 minutes to achieve proper sterilization.

Joule, Zhao et al.: "A passive high-temperature high-pressure solar steam generator for medical sterilization" DOI: 10.1016/j.joule.2020.10.007,
www.cell.com/joule/fulltext/S2542-4351(20)30496-7

https://techxplore.com/news/2020-11-solar-device-sterilize-medical-...

How giant viruses fuel the evolution of algae

Viruses are tiny invaders that cause a wide range of disease. But viruses can do more than elicit sickness—and not all viruses are tiny.

Large viruses, especially those in the nucleo-cytoplasmic large DNA virus family, can integrate their genome into that of their host—dramatically changing the genetic makeup of that organism. This family of DNA viruses, otherwise known as "giant" viruses, has been known within scientific circles for quite some time, but the extent to which they affect eukaryotic organisms has been shrouded in mystery—till now.

Viruses play a central role in the evolution of life on Earth. One way that they shape the evolution of cellular life is through a process called endogenization, where they introduce new genomic material into their hosts. When a giant virus endogenizes into the genome of a host algae, it creates an enormous amount of raw material for evolution to work with.

Researchers discovered that 24 of the 65 genomes they analyzed had some kinds of viral signatures in their genomes, which originated from repeated endogenization of distinct viruses. In one algal organism, Tetrabaena socialis, researchers found that around 10 percent of its genes originated from a virus in the nucleo-cytoplasmic large DNA virus family.

Although the endogenization of viruses have been well studied, studies have mostly been limited to small RNA viruses, such as the human immunodeficiency virus (HIV), the retrovirus that is responsible for causing acquired immunodeficiency syndrome (AIDS).

Widespread endogenization of giant viruses shapes genomes of green algae, Nature (2020). DOI: 10.1038/s41586-020-2924-2 , www.nature.com/articles/s41586-020-2924-2

https://phys.org/news/2020-11-lurking-genomic-shadows-giant-viruses...

The magic of science: Making diamonds in minutes!

An international team of scientists has defied nature to make diamonds in minutes in a laboratory at room temperature—a process that normally requires billions of years, huge amounts of pressure and super-hot temperatures.

The scientific team made two types of diamonds: the kind found on an engagement ring and another type of diamond called Lonsdaleite, which is found in nature at the site of meteorite impacts such as Canyon Diablo in the US.

Natural diamonds are usually formed over billions of years, about 150 kilometres deep in the Earth where there are high pressures and temperatures above 1,000 degrees Celsius.

This new unexpected discovery shows both Lonsdaleite and regular diamond can also form at normal room temperatures by just applying high pressures—equivalent to 640 African elephants on the tip of a ballet shoe.

The twist in the story is how researchers  applied the pressure. As well as very high pressures, they allowed the carbon to also experience something called 'shear' - which is like a twisting or sliding force. This might allow the carbon atoms to move into place and form Lonsdaleite and regular diamond.

Dougal G. McCulloch et al. Investigation of Room Temperature Formation of the Ultra‐Hard Nanocarbons Diamond and Lonsdaleite, Small (2020). DOI: 10.1002/smll.202004695

https://phys.org/news/2020-11-scientists-insta-bling-room-temperatu...

A DNA-based nanogel for targeted chemotherapy

Current chemotherapy regimens slow cancer progression and save lives, but these powerful drugs affect both healthy and cancerous cells. 

Now, researchers reporting in ACS' Nano Letters have designed DNA-based nanogels that only break down and release their chemotherapeutic contents within cancer cells, minimizing the impacts on normal ones and potentially eliminating painful and uncomfortable side effects.

Once ingested or injected, chemotherapy medications move throughout the body, indiscriminately affecting healthy cells along with those that are responsible for disease. Since many of these drugs are toxic to all cells, the desired tumor shrinkage can be accompanied by undesirable side effects, such as hair loss, gastrointestinal issues and fatigue. Nanogels made of DNA are one way that these drugs could be delivered, but they would still enter all cells. Tianhu Li, Teck-Peng Loh and colleagues reasoned that biomarkers—proteins or other components that are present in differing amounts in cancer cells and their healthy counterparts—could play a role in breaking down a nanogel, causing it to release its contents only in those that are cancerous. A biomarker called FEN1, a repair enzyme that cuts certain types of DNA, is present in larger amounts in cancer cells compared with healthy ones. The researchers wanted to see whether they could design a DNA nanogel that would specifically be degraded in cancer cells by FEN1.

To make DNA nanogels, the researchers used special DNA structures that FEN1 could recognize and cut. With cell-free systems, the researchers observed that the DNA-based nanogels were broken down by FEN1 but not by other DNA repair enzymes or compounds. When live cells were incubated with the DNA-based nanogels, healthy ones did not have enough FEN1 to break them down, but cancer cells did. When the chemotherapeutic drugs doxorubicin and vinorelbine were incorporated into the nanogel, human breast cancer cells died at higher rates than normal, healthy breast cells.

These findings indicate DNA-based nanogels can introduce drugs into cancer cells with a high specificity, reducing the risk of side effects. The researchers say that the nanogels also could be used as probes for the biomarker enzyme, helping physicians more directly diagnose cancer compared with current methods.

Hao Zhang et al. Cancer Biomarker-Triggered Disintegrable DNA Nanogels for Intelligent Drug Delivery, Nano Letters (2020). DOI: 10.1021/acs.nanolett.0c03671

https://phys.org/news/2020-11-dna-based-nanogel-chemotherapy.html?u...

SCI-COM: Time for scientists to speak up and be heard

https://www.scidev.net/asia-pacific/governance/columns/time-for-sci...

Strange Case : Kids Develop Coronavirus Antibodies Without Ever Testing Positive

From the early days of the coronavirus pandemic, scientists observed that children seemed to be less susceptible to developing COVID-19, although the exact reasons why remain unclear.
Now, an unusual case in Australia may provide unique insight into the mystery. In this family of five, the two parents became sick with COVID-19 after attending an interstate wedding without their children. However, the symptoms didn't show until days after they had returned from the trip.

Nonetheless, completely unbeknownst to them, they had brought SARS-CoV-2 into their home, and exposed their children to it. Once both the parents developed symptoms – including cough, congested nose, fever and headache – the entire family was tested for the virus. The parents' tests came back positive. The children's tests came back negative.
Healthcare workers asked the family to repeat the tests, but again the children's tests came back negative for SARS-CoV-2, even though two of the boys in the family (aged 9 and 7) had mild symptoms.
The youngest child, a 5-year-old daughter, remained asymptomatic throughout the entire episode, even though she was frequently sleeping in the same bed as the parents during their sickness (physical distancing precautions not feasible in the household during their quarantine).

Intrigued by the children's negative results while living in such close proximity to their infected parents, researchers asked the family to take part in a study, analysing samples of their blood, saliva, stools, and urine, and taking nose and throat swabs every two to three days.

Strangely enough, despite repeated polymerase chain reaction (PCR) tests showing the children were consistently SARS-CoV-2 PCR negative, the researchers found SARS-CoV-2 specific antibodies in saliva of all the family members, and in detailed serology testing.

In other words, the children never tested positive for the virus, but some level of exposure to the virus had nonetheless triggered an immune response inside them, and one seemingly capable of countering the infection.
The youngest child, who showed no symptoms at all, had the strongest antibody response. Despite the active immune cell response in all children, levels of cytokines, molecular messengers in the blood that can trigger an inflammatory reaction, remained low. This was consistent with their mild or no symptoms.
The fact these children were able to shut down the virus and without even showing a positive test result suggests they have some level of their immune system which is able to respond and deal effectively with the virus, without them ever becoming very unwell.
In effect, the researchers think that the children did actually become infected by the virus, but their immune systems were somehow able to mount an anti-virus response that was highly effective in restricting virus replication, unlike their parents.

That immune response was so effective, it could have brought the viral load so low, that it went under the sensitivity of the PCR testing, which is another issue that bears further examination, the team thinks.

"The discordance between the virological PCR results and clinical serological testing, despite an evident immune response, highlights limitations to the sensitivity of nasopharyngeal PCR and current diagnostic serology in children," the researchers write.
https://www.nature.com/articles/s41467-020-19545-8
https://www.sciencealert.com/everyone-in-this-family-has-coronaviru...

New effective and safe antifungal isolated from sea squirt microbiome

By combing the ocean for antimicrobials, scientists have discovered a new antifungal compound that efficiently targets multi-drug-resistant strains of deadly fungi without toxic side effects in mice.

The new molecule was discovered in the microbiome of a sea squirt from the Florida Keys as part of an effort to identify novel antimicrobials from understudied ecosystems. Scientists named the antifungal turbinmicin, after the sea squirt from which it was isolated, Ecteinascidia turbinate.

The researchers tested purified turbinmicin against a slate of 39 fungi isolated from patients. These strains both represented diverse species and encompassed all the known ways that fungi have evolved resistance to existing drugs. In lab experiments, turbinmicin halted or killed nearly all fungal strains at low concentrations, indicating a potent effect.

Similar experiments in mice infected with drug-resistant strains of Candida auris and Aspergillus fumigatus also demonstrated turbinmicin's ability to attack resistant fungi. Because fungi and animals are closely related, and thus share similar cellular machinery, antifungals can prove toxic to animals as well. Yet, turbinmicin did not show toxic side effects in mice, even at concentrations 1000 times higher than the minimum dose. The effective dose would work out to tens of milligrams for an average-weight adult, less than for many other antibiotics.

F. Zhang el al., "A marine microbiome antifungal targets urgent-threat drug-resistant fungi," Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abd6919

"Drugs from bugs in creatures of the sea," Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abf1675

https://phys.org/news/2020-11-effective-safe-antifungal-isolated-se...

Disease-causing fungi continue to evolve resistance to the small number of drugs available to thwart them. As a result, more people are dying from previously treatable diseases, such as candidiasis or aspergillosis, which are caused by common fungi that sometimes turn virulent. Identifying compounds like turbinmicin is key to developing new and effective drugs. However, while turbinmicin is a promising drug candidate, additional study of the molecule and extensive preclinical research must be performed before a new drug can become available.

Researchers show water has multiple liquid states

An international team of researchers has shown that water can exist in two different liquid states—a finding that can explain many of water's anomalous properties.

The possibility that water could exist in two different liquid states was proposed approximately 30 years ago, based on results obtained from computer simulations. This hypothesis has been one of the most important questions in the chemistry and physics of water, and a controversial scenario since its beginnings. This is because experiments that can access the two liquid states in water have been very challenging due to the apparently unavoidable ice formation at the conditions where the two liquids should exist.

The usual "liquid" state of water that we are all familiar with corresponds to liquid water at normal temperatures (approximately 25 degrees C). However, a new research paper shows that water at low temperatures (approximately -63 degrees C) exists in two different liquid states, a low-density liquid at low pressures and a high-density liquid at high pressures. These two liquids have noticeably different properties and differ by 20% in density. The results imply that at appropriate conditions, water should exist as two immiscible liquids separated by a thin interface similar to the coexistence of oil and water.

Because water is one of the most important substances on Earth—the solvent of life as we know it—its phase behaviour plays a fundamental role in different fields, including biochemistry, climate, cryopreservation, cryobiology, material science, and in many industrial processes where water acts as a solvent, product, reactant, or impurity. It follows that unusual characteristics in the phase behaviour of water, such as the presence of two liquid states, can affect numerous scientific and engineering applications.

Experimental observation of the liquid-liquid transition in bulk supercooled water under pressure. Science (2020). science.sciencemag.org/lookup/ … 1126/science.abb9385

https://phys.org/news/2020-11-multiple-liquid-states.html?utm_sourc...

Undesirable rejection mechanism identified in stem cell transplantation

In the treatment of leukemia, stem cell transplantation subsequent to chemotherapy and radiation can often engender severe adverse inflammatory reactions—especially in the skin or in the gut, since these so-called barrier organs are more frequently affected. Up until now, the reason for this was unclear till now. Scientists now identified an immune mechanism that is partially responsible for this.

The term leukemia is used to describe a group of malignant diseases of the haematopoietic system, in which precursors of the white blood cells (leucocytes) proliferate uncontrollably. Chemotherapy and radiotherapy are used to destroy the abnormal blood cells, which are then replaced by means of a stem cell transplant. In leukemia, the transplantation of healthy bone marrow stem cells or haematopoietic stem cells is often the only hope of recovery for patients. The process involves "replacing" all the recipient's blood cells that were previously destroyed by the treatment with donor cells.

However, the MedUni Vienna dermatologists have now found that there are so-called skin-resident and inactive T cells in the endogenous immune system that survive chemotherapy and radiotherapy intact and go on to survive for a further ten years between and beneath the epithelial cells of the skin, while the circulating T cells are destroyed.

"We were able to demonstrate that T cells surviving in the skin tissue are responsible for the inflammatory reaction following a stem cell transplant. These phenomena often occur within the first 100 days and can cause anything from mild eczema through to extensive fibrosis, hardening of the tissue, or blistering on the surface of the skin. In other words, the endogenous T cells attack the recipient (host) following stem cell transplantation." In specialist jargon, the condition is also referred to as Graft versus Host Disease (GvHD), and, for the first time, this study identified an inverse "Host-versus-graft reaction."

There were also cases in which the donor T cells further "supported," and thus intensified, this reaction. Affected patients are treated with cortisone, which causes an additional burden for patients who are already immunosuppressed following the transplantation. The study found that in patients who do not develop graft-versus-host disease, tissue-resident T cells remaining after treatment even proved to be beneficial to the recipient, in that they assumed their role in immune defense and protecting against infection.

In the future, the exemplary study results could lead to new treatment strategies that help to avoid, or at least to minimize, undesirable and violent inflammatory reactions following stem cell transplants by manipulating the recipient's inactive T cells in advance. In addition, the manipulation of tissue-resident T cells might lead to new therapeutic approaches for other chronic inflammatory skin diseases, such as psoriasis or neurodermatitis.

Johanna Strobl et al. Long-term skin-resident memory T cells proliferate in situ and are involved in human graft-versus-host disease, Science Translational Medicine (2020). DOI: 10.1126/scitranslmed.abb7028

https://medicalxpress.com/news/2020-11-undesirable-mechanism-stem-c...

.

The fundamental chemistry behind electrocatalytic water splitting

https://phys.org/news/2020-11-fundamental-chemistry-electrocatalyti...

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New system can sterilize medical tools using solar heat

Gut microbiome manipulation could result from virus discovery

Scientists have discovered how a common virus in the human gut infects and takes over bacterial cells – a finding that could be used to control the composition of the gut microbiome, which is important for human health.

The Rutgers co-authored research, which could aid efforts to engineer beneficial bacteria that produce medicines and fuels and clean up pollutants.
CrAssphages are the most abundant viruses infecting bacteria in the human gut. As such, they likely control our intestinal community of microbes (the microbiome).Understanding how these tiny viruses infect bacteria may allow scientists to control and manipulate the makeup of the microbiome, either by increasing the proportion of beneficial bacteria in our intestines or decreasing the number of harmful bacteria, thus promoting health and fighting disease.
Scientists found that crAssphages use their own enzyme (an RNA polymerase) to make RNA copies of their genes. RNA has the genetic information to make proteins. All cells, ranging from bacterial to human, use such enzymes to make RNA copies of their genes. And these enzymes are very similar in all living matter, implying that they’re ancient and related by common ancestry.
The atomic structure of a crAssphage enzyme is distinct from other RNA polymerases but closely resembles an enzyme in humans and other higher organisms that is involved in RNA interference. Such interference silences the function of some genes and may lead to certain diseases.

This is a startling result. It suggests that enzymes of RNA interference, a process that was thought to occur only in cells of higher organisms, were ‘borrowed’ from an ancestral bacterial virus early in evolution. The result provides a glimpse of how cells of higher organisms evolved by mixing and matching components of simpler cells and even their viruses.

In addition to deep evolutionary insights, phage (viral) enzymes such as crAssphage RNA polymerase may be used in synthetic biology to generate genetic circuits that do not exist in nature.

https://www.rutgers.edu/news/gut-microbiome-manipulation-could-resu...

https://researchnews.cc/news/3670/Gut-microbiome-manipulation-could...

Scientists identify brain cells that drive wakefulness and resist general anesthetics
Neuroscientists don’t know precisely what brain circuits control wakefulness and sleep, nor exactly how drugs for general anesthesia affect those circuits. But a new study from Penn Medicine researchers brings neuroscience a step closer to solving that important conundrum.

A team of researchers from the Perelman School of Medicine at the University of Pennsylvania, in a study published online Nov. 13 in Current Biology, identified a population of neurons in the hypothalamus region of the brain that keeps mice from sleeping when they normally would when they are activated. Activating these neurons also “wakes” them from ongoing exposure to inhaled anesthetics like isoflurane or sevoflurane, and even helps maintain the alert state when animals are dosed with anesthetics.

The study also supports a hypothesis long debated by neuroscientists: that the parts of the brain regulating sleep and waking are also capable of regulating the brain’s response to general anesthetics.

https://www.pennmedicine.org/news/news-releases/2020/november/scien...

https://researchnews.cc/news/3673/Scientists-identify-brain-cells-t...

Your Tears Might Save Your Life Someday

They could ultimately be used to find diseases the way blood tests do now—but cheaper and more easily

At any given moment, about seven microliters of tears are present in each of our eyes—about a tenth of a drop of water. You might think of them as nothing more than salty water, but it’s more accurate to think if them filtered blood; they deliver oxygen and nutrients to our eyes, removing waste, serving as the first line of defense against pathogens and helping to heal injuries.

Tears also contain traces of the various chemicals originally present in blood, some of which serve as markers of illness—glucose, for example, which can signal diabetes, or enzymes that point to possible liver disease. That’s a primary reason doctors order blood tests. But it also that means that physicians—and maybe, in the near future, you—can look for indicators of illness by looking at your tears.

https://www.scientificamerican.com/article/your-tears-might-save-yo...

How rotavirus causes severe gastrointestinal disease

Rotavirus is a major cause of diarrhea and vomiting, especially in children, that results in approximately 128,000 deaths annually. The virus triggers the disease by infecting enterocyte cells in the small intestine, but only a fraction of the susceptible cells has the virus. In the mid-90s, scientists proposed that the small portion of infected cells promotes severe disease by sending out signals that disrupt the normal function of neighbouring uninfected cells, but the nature of the signal has remained a mystery.

In the current study published in the journal Science, a team led by researchers at Baylor College of Medicine discovered that rotavirus-infected cells release signaling molecules, identified as adenosine diphosphate (ADP), which binds its cellular receptor P2Y1 on neighboring cells. Activating P2Y1 by ADP results in signals called intercellular calcium waves in these uninfected cells. Disrupting ADP binding to its receptor reduced the severity of diarrhea in a mouse model of the disease, suggesting that targeting the P2Y1 may be an effective strategy to control viral diarrhea in human populations.

Further studies revealed previously unknown roles of ADP on rotavirus infection and replication, shining a spotlight on ADP as an important trigger of the multiple factors involved in severe diarrhea and vomiting caused by rotavirus. For instance, the researchers found evidence that ADP signaling increases rotavirus infection, the expression of inflammatory cytokine IL1-alpha and the secretion of serotonin, an inducer of diarrhea. ADP signaling also increases the expression of enzymes that produce prostaglandin and nitric oxide, potentially causing the increases in those compounds observed in rotavirus infection. Preventing ADP signaling and intercellular calcium waves reduced the production of the compounds mentioned above.

 Alexandra L. Chang-Graham et al, Rotavirus induces intercellular calcium waves through ADP signaling, Science (2020). DOI: 10.1126/science.abc3621

https://medicalxpress.com/news/2020-11-rotavirus-severe-gastrointes...

**In a First, Scientists Say They've Partially Reversed a Cellular Aging Process in Humans

Every time a cell inside your body replicates, a slither of your youth crumbles to dust. This occurs via the shortening of telomeres, structures that 'cap' the tips of our chromosomes.

Now, scientists in Israel say they've been able to reverse this process and extend the length of telomeres in a small study involving 26 patients.

The participants sat in a hyperbaric oxygen chamber for five 90 minutes sessions per week over three months, and as a result, some of their cell's telomeres were extended by up to 20 percent.

It's an impressive claim - and something many other researchers have attempted in the past without success. But of course it's worth flagging that this is a small sample size, and the results will need to be replicated before we can get too excited. 

However, the fact that hyperbaric oxygen therapy appears to affect telomere length is a compelling link worth investigating further. 

Telomeres are repeating chunks of code that act as the DNA equivalent of the plastic or metal aglet capping the end of a shoelace.

They copy themselves along with the rest of the chromosomes whenever a cell divides. Yet with every replication, tiny fragments of code from the very tip of the sequence fail to make it into the new copy, leaving the freshly minted chromosome a touch shorter than its predecessor.

As anybody who has lost the cap of their shoelace knows, it doesn't take long for the shoelace to lose its integrity. Similarly, shorter telomeres put sequences further down the chromosome at higher risk of hazardous mutations.

These mutations coincide with changes that predispose us to a bunch of age-related conditions, not least of all diseases such as cancer.

That's not necessarily to say that we age because our telomeres shrink, but there is a connection between telomere length and health that researchers are keen to investigate further.

"Longer telomeres correlates with better cellular performance. There are plenty of ways to accelerate the erosion of our telomeres. Failing to get adequate sleep could do it, as might chowing down on too much processed food, and maybe even having kids.
Slowing down the loss takes a bit more effort, but engaging in regular exercise and eating well are sound bets if you want your chromosomes to remain as long as possible.

A real achievement would be to flip our chromosomal hourglass completely and return lost sections of telomere. The fact that high-turnover tissues lining our gut do this naturally using an enzyme called telomerase has fuelled research over the years.

There have been plenty of milestones in attempts to achieve this task. Gene therapy in mice has shown it could one day be feasible in humans. More recently, stem cells from a supercentenarian woman had their telomeres completely reset outside of her body.

Some studies have found potential for tiny increases of maybe a few percent with provision of nutritional supplements such as vitamin D.

https://www.aging-us.com/article/202188/text

https://www.sciencealert.com/oxygen-therapy-found-to-turn-back-the-...

** Asymptomatic Children Can Spread Malaria to Mosquitoes

Children infected with malaria can become 'superspreaders' and pass the parasite to droves of local mosquitoes, even if the kids never develop symptoms of the disease, a new study suggests. 

Since this disease is passed from humans to mosquitoes and then back again, rather than from person to person, this finding is worrisome. If malaria goes untreated in these asymptomatic children, the parasites will continue to circulate among mosquitoes, even in places that employ intensive malaria controls like insecticides, bednets, and free diagnostic tests and treatments. According to new research, presented Wednesday (Nov. 18) at the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), even a small number of infected children can transmit malaria parasites to a mob of mosquitoes, which can then go on to infect more humans. From their new research in Uganda, the researchers concluded that asymptomatic children between ages 5 and 15 are the main source of infection for local mosquitoes in the region they studied. Some of these children were so-called superspreaders, meaning they infected a much larger number of mosquitoes than others; in experiments where mosquitoes were fed blood samples from infected people, more than 60 percent of the resulting mosquito infections could be traced back to just four asymptomatic children, two of whom were school-age. The other two superspreaders were ages 3 and 4.

Despite some children becoming infected with multiple malaria clones during the study, these kids never fell ill and continued to lead a "normal life … somehow living with all these parasites

https://www.livescience.com/asymptomatic-children-malaria-reservoir...

3D-printed, lifelike heart models could help train tomorrow’s surgeons

Astronomers discover new 'fossil galaxy' buried deep within the Milky Way

Scientists working with data from the Sloan Digital Sky Surveys' Apache Point Observatory Galactic Evolution Experiment (APOGEE) have discovered a "fossil galaxy" hidden in the depths of our own Milky Way.

The proposed fossil galaxy may have collided with the Milky Way ten billion years ago, when our galaxy was still in its infancy. Astronomers named it Heracles, after the ancient Greek hero who received the gift of immortality when the Milky Way was created.

The remnants of Heracles account for about one third of the Milky Way's spherical halo. But if stars and gas from Heracles make up such a large percentage of the galactic halo, why didn't we see it before? The answer lies in its location deep inside the Milky Way.

"To find a fossil galaxy like this one, we had to look at the detailed chemical makeup and motions of tens of thousands of stars. That is especially hard to do for stars in the center of the Milky Way, because they are hidden from view by clouds of interstellar dust. APOGEE lets us pierce through that dust and see deeper into the heart of the Milky Way than ever before.

APOGEE does this by taking spectra of stars in near-infrared light, instead of visible light, which gets obscured by dust. Over its ten-year observational life, APOGEE has measured spectra for more than half a million stars all across the Milky Way, including its previously dust-obscured core and finally discovered this fossil galaxy .

"Evidence from APOGEE for the Presence of a Major Building Block of the Halo Buried in the Inner Galaxy," Danny Horta et al., 2020 Nov. 20, Monthly Notices of the Royal Astronomical Society: arxiv.org/abs/2007.10374].

https://phys.org/news/2020-11-astronomers-fossil-galaxy-deep-milky....

Fake news and misinformation kill: How can you trust what you are told about Covid-19?

**Virus evolution could undermine a COVID-19 vaccine – but this can be stopped

https://theconversation.com/virus-evolution-could-undermine-a-covid...

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Ultrasound Reveals Parasitic Worms Squirming Around Inside Man's Stomach in Delhi

Previewed Reality: A system that allows users to predict future changes in their environment

When robots and humans interact in a shared environment, it is important for them to move in ways that prevent collisions or accidents. To reduce the risk of collisions, roboticists have developed numerous of techniques that monitor an environment, predict the future actions of humans moving in it, identify safe trajectories for a robot and control its movements accordingly.

Researchers at Kyushu University in Japan recently created a system that allows human users to forecast future changes in their environment, which could then inform their decisions and guide their actions. 

To collect information about the position of different objects, robots and humans in a shared environment, the researchers used a number of strategically placed sensors, including optical trackers and an RGB-D camera. The optical trackers monitored the movements of objects or robots, while the RGB-D camera mainly tracked human actions.

The data gathered by the sensors was then fed to a motion planner and a dynamics simulator. Combined, these two system components allowed the researchers to forecast changes in a given environment and synthesize images of events that are likely to occur in the near future, from the viewpoint of a specific human.

Human users could then view these synthesized images simply by wearing a VR headset or an AR display. On the headset or display, the images were layed over those of a user's actual surroundings, in order to clearly illustrate the changes that could take place in the future.

Asuka Egashira et al. Near-future perception system: Previewed Reality, Advanced Robotics (2020). DOI: 10.1080/01691864.2020.1829041

https://techxplore.com/news/2020-11-previewed-reality-users-future-...

Social bacteria build shelters using the physics of fingerprints

Forest-dwelling bacteria known for forming slimy swarms that prey on other microbes can also cooperate to construct mushroom-like survival shelters known as fruiting bodies when food is scarce. Now a team at Princeton University has discovered the physics behind how these rod-shaped bacteria, which align in patterns like those on fingerprint whorls and liquid crystal displays, build the layers of these fruiting bodies.

( See pic above )

In some ways, these bacteria  are teaching us new kinds of physics. These questions exist at the intersection of physics and biology. And you need to understand both to understand these organisms.

Myxococcus xanthus, or Myxo for short, is a bacterial species capable of surprisingly cooperative behaviors. For example, large numbers of Myxo cells  come together to hunt other bacteria by swarming toward their prey in a single undulating mass.

When food is scarce, however, the rod-like cells stack atop one another to form squishy growths called fruiting bodies, which are hideaways in which some of the Myxo cells transform into spores capable of rebooting the population when fresh nutrients arrive. But until now, scientists haven't understood how the rods acquire the ability to begin climbing on top of each other to build the droplet-like structures.

To find out more about how these bacteria behave, the researchers set up a microscope capable of tracking Myxo's actions in three dimensions. The scientists recorded videos of the rod-shaped microbes, which pack closely together like stampeding wildebeest, rushing across the microscope dish in swaths that swirl around each other, forming fingerprint-like patterns.

When two swaths meet, the researchers observed, the point of intersection was exactly where the new layer of cells started to form. The bacteria started to pile up and created a situation where the only direction to go was up. these bacteria are exploiting particular points of the cell alignment where stresses build that enable the colony to construct new cell layers, one on top of the other. And that's ultimately how this colony responds to starvation. Researchers call the points where the massing cells collide "topological defects," a term that refers to the mathematics that describe these singular points. Topology is the branch of mathematics that finds similarities between objects such as teacups and donuts, because one can be stretched or deformed into the other.

Myxo bacterial cells behave much like liquid crystals, the fluids found in smartphone screens, which are made of rod-shaped molecules. Unlike passive liquid crystals, however, Myxo rods are alive and can crawl. The bacteria most likely have evolved to take advantage of both passive and active factors to build the fruiting bodies.

The combination of physics and biology training among the researchers enabled them to recognize new theoretical insights into how the vertical layers form.

Understanding ion channel inhibition to open doors in drug discovery

Scientists have discovered how drug-like small molecules can regulate the activity of therapeutically relevant ion channels—and their findings could transform ongoing drug development efforts.

A major mechanism by which cells communicate with their environment is the movement of metal ions through channels located within their cell membranes.

The new study by researchers at the University of Leeds, published today in Communications Biology, provides detailed insight into the regulation of TRPC5 ion channels, which allow positively charged ions such as calcium, sodium and potassium to flow in and out of cells.

TRPC5 channels are considered potential therapeutic targets for the treatment of a range of conditions, including anxiety, kidney disease and cardiovascular disease.

Cryo-EM structures of human TRPC5 reveal interaction of a xanthine-based TRPC1/4/5 inhibitor with a conserved lipid binding site, Communications Biology (2020).

https://phys.org/news/2020-11-ion-channel-inhibition-doors-drug.htm...

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Scientists observe directed energy transport between neighboring molecules in a nanomaterial

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 molecules of a nanomaterial. Theoretical simulations have confirmed the experimental results. 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. 

 Antonietta De Sio et al, Intermolecular conical intersections in molecular aggregates, Nature Nanotechnology (2020). DOI: 10.1038/s41565-020-00791-2

https://phys.org/news/2020-11-scientists-energy-neighboring-molecul...

Nature's toolkit for killing viruses and bacteria

Tiny infectious microbes—from the virus that causes COVID-19 to waterborne bacteria—kill millions of people around the world each year. Now engineers are studying how zinc oxide surfaces and natural hydrodynamic churning have the power to kill pathogens first.

Reseachers now  submerged clean zinc in hot water for 24 hours, which formed a zinc oxide surface covered in sharp nanoneedles. Then they introduced E. coli bacteria.

The surface kills almost all bacteria cultured on top of it very efficiently. And the biggest surprise? When sitting in contaminated water, the surface kills all waterborne E. coli within three hours—even bacteria it didn't touch.

This water disinfection at a distance works because the process generates a reactive oxygen species, which damages the cell walls of bacteria. 

This surface can be used to disinfect water in remote areas at a very low cost. "The fabrication technique is environmentally friendly, simple, and economical."

Environmental Friendly and Scalable Fabrication of Antibacterial ZnO-Nanostructured Surfaces, meetings.aps.org/Meeting/DFD20/Session/Z01.12

https://phys.org/news/2020-11-nature-toolkit-viruses-bacteria.html?...

**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...

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...

Deep learning helps robots grasp better

**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...

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-...

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.

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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.