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Comment by Dr. Krishna Kumari Challa on June 8, 2021 at 10:13am

A new material made from carbon nanotubes can generate electricity by scavenging energy from its environment

Engineers have discovered a new way of generating electricity using tiny carbon particles that can create a current simply by interacting with liquid surrounding them.

The liquid, an organic solvent, draws electrons out of the particles, generating a current that could be used to drive chemical reactions or to power micro- or nanoscale robots, the researchers say.

"This mechanism is new, and this way of generating energy is completely new.

When a carbon nanotube is coated with layer of fuel, moving pulses of heat, or thermopower waves, travel along the tube, creating an electrical current.

This technology is intriguing because all you have to do is flow a solvent through a bed of these particles. This allows you to do electrochemistry, but with no wires.

In a new study describing this phenomenon, the researchers showed that they could use this electric current to drive a reaction known as alcohol oxidation—an organic chemical reaction that is important in the chemical industry.

Albert Tianxiang Liu et al, Solvent-induced electrochemistry at an electrically asymmetric carbon Janus particle, Nature Communications (2021). DOI: 10.1038/s41467-021-23038-7

https://phys.org/news/2021-06-material-carbon-nanotubes-electricity...

Comment by Dr. Krishna Kumari Challa on June 8, 2021 at 9:56am

A framework to simulate the same physics using two different Hamiltonians

Researchers  have recently been investigating situations in which two distinct Hamiltonians could be used to simulate the same physical phenomena. A Hamiltonian is a function or model used to describe a dynamic system, such as the motion of particles.

In a paper published in Physical Review Letters,  researchers introduced a framework that could prove useful for simulating the same physics with two distinct Hamiltonians. In addition, they provide an example of an analog simulation and show how one could build an alternative version of a digital quantum simulator.

Their result indicates that using the same Hamiltonian is not always a necessary condition. As an example, they showed that the physics of one-axis twisting can be simulated by a spin chain with an external field, even though the one-axis twisting model has infinite range interactions and this spin chain model has only nearest-neighboring interactions. The Hamiltonian of these two models are physically different, i.e. having different energy spectra, but still one can simulate the one with the other if the dynamics starts with special states.

 Simulating the same physics with two distinct Hamiltonians. Physical Review Letters(2021). DOI: 10.1103/PhysRevLett.126.160402.

https://phys.org/news/2021-06-framework-simulate-physics-hamiltonia...

Comment by Dr. Krishna Kumari Challa on June 7, 2021 at 7:02am

Part 4:

Despite that, the Indian recommendation still works out to a wide range across moderate and severe categories — from a low of about 35 mg to a high of 140 mg (for a 70kg person). This is in sharp contrast to the 32mg (total daily dose) recommendation in the US.

Indian government spokespersons have attributed the rise in fungal infections to the fact doctors in the country may have irrationally used steroids.

But given the government’s own guidelines for steroid use are so much higher than in other countries, there should be analysis into whether this may be contributing to the significant rise in fungal infections (3).

Those findings would have profound implications on India’s pandemic management.

Footnotes: 

1. Now we have white and yellow fungi to deal with
2. Potentially fatal 'black fungus' infections in COVID-19 patients
3. Doctors have been blamed for the rise in black fungus in India, but...

Comment by Dr. Krishna Kumari Challa on June 7, 2021 at 6:59am

Part 3: 

A study of ten Indian hospitals found 74% of patients with secondary infections during the first wave were given antibiotics the WHO has said should be used sparingly, and another 9% received antibiotics that were not recommended.

The guidelines should advise the same procedure for moderate and severe cases, that is, to conduct blood cultures before starting patients on antimicrobial therapy to ensure the antibiotics will work, and that they won’t lead to a secondary fungal infection.

One of the recommended COVID treatments of the National Institute of Health in the US is 32mg a day of the steroid methylprednisolone.

In March 2020, Indian guidelines for treatment recommended 1-2mg methyprednisolone per kilo of body weight for patients with severe symptoms (so 70-140mg for a 70kg person).

This was updated in June 2020 with a lower dose of methylprednisolone (35–70mg per day for a 70kg person) for three days for moderate cases and the original recommended dose (70–140mg per day for a 70kg person) for five to seven days for severe cases.

The most recent guideline of April 2021 does not alter the dosage per day but recommended an increased duration of therapy, five to ten days, for both moderate and severe cases.

Comment by Dr. Krishna Kumari Challa on June 7, 2021 at 6:58am

Part 2:

The two most recent versions of COVID treatment guidelines in India (June 27, 2020 and May 24, 2021) rightly state antibiotics should not be prescribed routinely.

Instead, they urge doctors to consider “empiric” antibiotic therapy as per a “local antibiogram” when COVID patients have moderate secondary infections. Empiric antibiotic therapy implies making a diagnosis based on what the literature says is the most likely pathogen (or bug) causing the infection. Antibiograms are sent out to hospitals periodically and they describe the current infections circulating in the area and which antiobiotics work against them.

For severe secondary infections, the guidelines suggest conducting blood cultures to check which antibiotic might work, ideally before the medication is started.

An empirical approach can work effectively only if a majority of COVID facilities treating moderate cases have access to local antibiograms. If they don’t, doctors will usually end up prescribing broad-spectrum antibiotics. Broad-spectrum antiobiotics kill a range of bugs, rather than a specific one, which is risky because they can also kill the good bugs we use to fight off things like fungal infections

Comment by Dr. Krishna Kumari Challa on June 7, 2021 at 6:58am

Part 1

Doctors have been blamed for the rise in black fungus in India, but the COVID treatment guidelines could be contributing

The emergence of black, white and yellow fungal infections are causing concern in India (1,2).

People use use black, white and yellow fungus to refer to mucormycosis, aspergillosis, candidiasis and cryptococcosis. Together, they are referred to as invasive fungal infections, and they usually infect people with an impaired immune system, or with damaged tissue. These are said to have been caused by misuse of steroids and antibiotics (which impair our ability to fight these fungal infections) in COVID treatments, and high numbers of patients with poorly controlled diabetes where tissue is damaged (3).

Could the situation have been averted? Perhaps, if the government had considered recent evidence and issued clear guidelines on using steroids and antiobiotics in treating COVID-19.

Comment by Dr. Krishna Kumari Challa on June 6, 2021 at 1:04pm

Part 2:

Shima Shahbaz, Lai Xu, Mohammed Osman, Wendy Sligl, Justin Shields, Michael Joyce, D. Lorne Tyrrell, Olaide Oyegbami, Shokrollah Elahi. Erythroid precursors and progenitors suppress adaptive immunity and get invaded by SARS-CoV-2. Stem Cell Reports, 2021; 16 (5): 1165 DOI: 10.1016/j.stemcr.2021.04.001

Comment by Dr. Krishna Kumari Challa on June 6, 2021 at 1:03pm

New study may help explain low oxygen levels in COVID-19 patients

 A new study published in the journal Stem Cell Reports by University of Alberta researchers is shedding light on why many COVID-19 patients, even those not in hospital, are suffering from hypoxia—a potentially dangerous condition in which there is decreased oxygenation in the body’s tissues. The study also shows why the anti-inflammatory drug dexamethasone has been an effective treatment for those with the virus.

Low blood-oxygen levels have been a significant problem in COVID-19 patients.

One potential mechanism might be that COVID-19 impacts red blood cell production.

In the study, the research team examined the blood of 128 patients with COVID-19. The patients included those who were critically ill and admitted to the ICU, those who had moderate symptoms and were admitted to hospital, and those who had a mild version of the disease and only spent a few hours in hospital. The researchers found that, as the disease became more severe, more immature red blood cells flooded into blood circulation, sometimes making up as much as 60 per cent of the total cells in the blood. By comparison, immature red blood cells make up less than one per cent, or none at all, in a healthy individual’s blood.

Immature red blood cells reside in the bone marrow and we do not normally see them in blood circulation. This indicates that the virus is impacting the source of these cells. As a result, and to compensate for the depletion of healthy immature red blood cells, the body is producing significantly more of them in order to provide enough oxygen for the body.

The problem is that immature red blood cells do not transport oxygen—only mature red blood cells do. The second issue is that immature red blood cells are highly susceptible to COVID-19 infection. As immature red blood cells are attacked and destroyed by the virus, the body is unable to replace mature red blood cells—which only live for about 120 days—and the ability to transport oxygen in the bloodstream is diminished.

The question was how the virus infects the immature red blood cells. It was found that immature red blood cells expressed the receptor ACE2 and a co-receptor, TMPRSS2, which allowed SARS-CoV-2 to infect them.

These findings are exciting but also show two significant consequences: First, immature red blood cells are the cells being infected by the virus, and when the virus kills them, it forces the body to try to meet the oxygen supply requirements by pumping more immature red blood cells out of the bone marrow. But that just creates more targets for the virus.

Second, immature red blood cells are actually potent immunosuppressive cells; they suppress antibody production and they suppress T-cell immunity against the virus, making the entire situation worse. So more immature red blood cells means a weaker immune response against the virus.

When the team began exploring why dexamethasone had such an effect, they found two potential mechanisms. First, dexamethasone suppresses the response of the ACE2 and TMPRSS2 receptors to SARS-CoV-2 in immature red blood cells, reducing the opportunities for infection. Second, dexamethasone increases the rate at which the immature red blood cells mature, helping the cells shed their nuclei faster. Without the nuclei, the virus has nowhere to replicate.

https://researchnews.cc/news/7075/New-study-may-help-explain-low-ox...

Comment by Dr. Krishna Kumari Challa on June 5, 2021 at 8:49am

Mockingbird song decoded

The North American mockingbird is famous for its ability to imitate the song of other birds. But it doesn't just mimic its kindred species, it actually composes its own songs based on other birds' melodies. An interdisciplinary research team has now worked out how exactly the mockingbird constructs its imitations. The scientists determined that the birds follow similar musical rules as those found in human music, from Beethoven to Kendrick Lamar.

--

The human genome: filling in the blanks

Scientists are a step closer to completely sequencing the entire human genome. An international collaboration of researchers has worked out how some stretches of DNA containing many repeating letters (or base pairs) fit together, and discovered about 115 genes that code for proteins in the process. The newly sequenced genome adds nearly 200 million base pairs to the most recent human genome sequence, which researchers have used as a reference since 2013.

A complete human genome sequence is close: how scientists filled in the gaps

Researchers added 200 million DNA base pairs and 115 protein-coding genes — but they’ve yet to entirely sequence the Y chromosome.

When the sequencing of the human genome was announced two decades ago by the Human Genome Project and biotech firm Celera Genomics, the sequence was not truly complete. About 15% was missing: technological limitations left researchers unable to work out how certain stretches of DNA fitted together, especially those where there were many repeating letters (or base pairs). Scientists solved some of the puzzle over time, but the most recent human genome, which geneticists have used as a reference since 2013, still lacks 8% of the full sequence.

Now, researchers in the Telomere-to-Telomere (T2T) Consortium, an international collaboration that comprises around 30 institutions, have filled in those gaps. In a 27 May preprint entitled ‘The complete sequence of a human genome’, genomics researcher Karen Miga at the University of California, Santa Cruz, and her colleagues report that they’ve sequenced the remainder, in the process discovering about 115 new genes that code for proteins, for a total of 19,969.

Nurk, S. et al. Preprint at bioRxiv https://doi.org/10.1101/2021.05.26.445798 (2021).

https://www.nature.com/articles/d41586-021-01506-w?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on June 5, 2021 at 8:43am

How to retard time for cells

Scientists have succeeded in reversibly slowing down cellular processes. A team of biophysicists were able to show in experiments that cells can be transferred into slow motion without changing the temperature.

 Cells are not only our biological building blocks, but also highly dynamic, active systems. The research group  has succeeded in significantly reducing these dynamics with heavy water, without damaging the cells. For cells, time—or, more specifically, their dynamics—can be significantly slowed down in the presence of heavy water.

The research showed on various biological levels that the movement of cells and their dynamics was only taking place in slow motion.

The researchers confirmed this effect with a variety of complementary methods and attributed the observations to an increased interaction between the structural proteins. "Heavy water also forms hydrogen bonds, but these are stronger than in normal aqueous environments. As a result, structural proteins such as actin seem to interact more strongly with one another and briefly stick together. What is spectacular here is that the effects are reversible, with cells showing their native properties again as soon as they are transferred into a normal aqueous medium.

These changes show the fingerprint of a passive material. However, cells are highly active and far from thermodynamic equilibrium. If they behave like a passive material, they are usually dead. However, as the researchers were able to show, this was not the case in their experiments. They now hope to be able to use the knowledge gained to keep cells or even tissue vital for longer. If this approach is confirmed, heavy water could be used for longer storage times, for example during organ transplants.

Jörg Schnauß et al, Cells in Slow Motion: Apparent Undercooling Increases Glassy Behavior at Physiological Temperatures, Advanced Materials (2021). DOI: 10.1002/adma.202101840

https://phys.org/news/2021-06-retard-cells.html?utm_source=nwletter...

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