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Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 9:24am

Older women more vulnerable to heat than their male peers, researchers find

As global climate change causes extreme heat waves to become more common around the world, epidemiological studies have shown that heat kills more women than men.

Now, a new study by researchers at Penn State has found that older women are physiologically more vulnerable to high heat and humidity than older men, and that women between the ages of 40 and 64 are as vulnerable as men 65 years of age or older.

This is the first study to determine that this disparity exists due to physiological differences and not because women live longer than men, which leaves a larger population of older women than older men.

 the researchers demonstrated that middle-aged and older women were affected by heat at lower temperature/humidity combinations than middle-aged and older men.

The results, published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, were somewhat unexpected because there are no differences in heat vulnerability based on biological sex in adults younger than 30.

In addition to demonstrating that middle-aged and older women are at greater risk from extreme heat, we also identified what levels of heat and humidity are safe for women as they age. This information is presented as a temperature/humidity curve based on a person's age, and it can be useful for setting policies designed to keep people safe during a heat wave.

 Olivia K. Leach et al, Sex differences in heat stress vulnerability among middle-aged and older adults (PSU HEAT Project), American Journal of Physiology: Regulatory, Integrative and Comparative Physiology (2024). DOI: 10.1152/ajpregu.00114.2024

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 9:03am

Newly discovered viruses in parasitic nematodes could change our understanding of how they cause disease

New research shows that parasitic nematodes, responsible for infecting more than a billion people globally, carry viruses that may solve the puzzle of why some cause serious diseases.

A study led by Liverpool School of Tropical Medicine (LSTM) used cutting-edge bioinformatic data mining techniques to identify 91 RNA viruses in 28 species of parasitic nematodes, representing 70% of those that infect people and animals. Often these are symptomless or not serious, but some can lead to severe, life-changing disease.

Nematode worms are the most abundant animals on the planet, prevalent in all continents worldwide, with several species infecting humans as well as agriculturally and economically important animals and crops. And yet in several cases, scientists do not know how some nematodes cause certain diseases.

The new research, published in Nature Microbiology, opens the door to further study of whether these newly discovered viruses—only five of which were previously known to science—could contribute to many chronic, debilitating conditions. If a connection can be proven, it could pave the way for more effective treatments in the future.

This raises the question of whether any of the diseases that these parasites are responsible for could be driven by the virus rather than directly by the parasitic nematode.

Parasitic nematodes including hookworms and whipworms can cause severe abdominal problems and bloody diarrhea, stunted development and anemia. Infection with filarial worms can lead to disfiguring conditions such as lymphedema or "elephantiasis," and onchocerciasis, or "river blindness," that leads to blindness and skin disease.

The study authors propose that these newly identified viruses may play a role in some of these conditions. For example, onchocerciasis-associated epilepsy (OAE) that occurs in children and adolescents in Sub-Saharan Africa has recently been associated with onchocerciasis, but it is not known why this causes neurological symptoms such as uncontrollable repeated head nodding, as well as severe stunting, delayed puberty and impaired mental health.

One of the viruses in the parasites that cause onchocerciasis identified in the new study is rhabdovirus—the type that causes rabies. The authors of the study suggest that if this virus is infecting or damaging human nerve or brain tissue, that could explain the symptoms of OAE.

The full extent and diversity of the viruses living in parasitic nematodes, how they impact nematode biology and whether they act as drivers of disease in people and animals now requires further study.

Quek, S., et al. Diverse RNA viruses of parasitic nematodes can elicit antibody responses in vertebrate hosts, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01796-6. www.nature.com/articles/s41564-024-01796-6

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Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 8:58am

Arctic microalgae show photosynthesis in near darkness is possible

Photosynthesis converts sunlight into biologically usable energy and thus forms the basis of all life on our planet. However, previous measurements of the amount of light required for this have always been well above the theoretically possible minimum. The study shows that the build-up of biomass can actually take place with a quantity of light that is close to this minimum.

Photosynthesis can take place in nature even at extremely low light levels. This is the result of an international study that investigated the development of Arctic microalgae at the end of the polar night. The measurements were carried out as part of the MOSAiC expedition at 88° northern latitude and revealed that even this far north, microalgae can build up biomass through photosynthesis as early as the end of March.

At this time, the sun is barely above the horizon, so that it is still almost completely dark in the microalgae's habitat under the snow and ice cover of the Arctic Ocean. The results of the study now published in the journal Nature Communications show that photosynthesis in the ocean is possible under much lower light conditions, and can therefore take place at much greater depths than previously assumed.

Clara J.M. Hoppe, Photosynthetic light requirement near the theoretical minimum detected in Arctic microalgae, Nature Communications (2024). DOI: 10.1038/s41467-024-51636-8

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 8:53am

Fungal spores of the mold Aspergillus fumigatus produce an enzyme that weakens the immune system

Aspergillus fumigatus is a mold that is found all over the world. Unlike closely related species, it can cause serious, often fatal infections in humans. What makes A. fumigatus so dangerous?

A special enzyme on the surface of the fungal spores—glycosylasparaginase—apparently suppresses the release of pro-inflammatory substances by immune cells, making it easier for the pathogen to spread unhindered in the tissue. The findings are published in the journal Nature Microbiology.

Camila Figueiredo Pinzan et al, Aspergillus fumigatus conidial surface-associated proteome reveals factors for fungal evasion and host immunity modulation, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01782-y

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 8:49am

People facing life-or-death choice put too much trust in AI

In simulated life-or-death decisions, about two-thirds of people in a  study allowed a robot to change their minds when it disagreed with them—an alarming display of excessive trust in artificial intelligence, researchers said.

Human subjects allowed robots to sway their judgment, despite being told the AI machines had limited capabilities and were giving advice that could be wrong. In reality, the advice was random.

As a society, with AI accelerating so quickly, we need to be concerned about the potential for over trust, say the researchers.

What we need instead is a consistent application of doubt.

We should have a healthy skepticism about AI, the researchers say, "especially in life-or-death decisions."

 Colin Holbrook et al, Overtrust in AI Recommendations About Whether or Not to Kill: Evidence from Two Human-Robot Interaction Studies, Scientific Reports (2024). DOI: 10.1038/s41598-024-69771-z

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 8:38am

Nuclear clock paves way for ultraprecise timekeeping

A new type of clock under development—a nuclear clock—could revolutionize how we measure time and probe fundamental physics.

An international research team led by scientists at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, has demonstrated key elements of a nuclear clock. A nuclear clock is a novel type of timekeeping device that uses signals from the core, or nucleus, of an atom.

The team presents the results in the Sept. 4 issue of the journal Nature as a cover story.

The team used a specially designed ultraviolet laser to precisely measure the frequency of an energy jump in thorium nuclei embedded in a solid crystal. They also employed an optical frequency comb, which acts like an extremely accurate light ruler, to count the number of ultraviolet wave cycles that create this energy jump. While this laboratory demonstration is not a fully developed nuclear clock, it contains all the core technology for one.
Nuclear clocks could be much more accurate than current atomic clocks, which provide official international time and play major roles in technologies such as GPS, internet synchronization, and financial transactions.

For the general public, this development could ultimately mean even more precise navigation systems (with or without GPS), faster internet speeds, more reliable network connections, and more secure digital communications.

Beyond everyday technology, nuclear clocks could improve tests of fundamental theories for how the universe works, potentially leading to new discoveries in physics. They could help detect dark matter or verify if the constants of nature are truly constant, allowing for verification of theories in particle physics without the need for large-scale particle accelerator facilities.

Chuankun Zhang, Frequency ratio of the 229mTh isomeric transition and the 87Sr atomic clock, Nature (2024). DOI: 10.1038/s41586-024-07839-6. www.nature.com/articles/s41586-024-07839-6

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 8:34am

Nanoplastics have potential to cross blood-brain barrier, study reveals

A new study published in the journal Nano Today reveals that nanoplastics, which are tiny plastic particles less than 1 micrometer in size, may cross the blood-brain barrier (BBB).

The research marks a significant advancement in understanding how nanoplastics might transfer in human blood and interact with biological systems.

An  international team of scientists investigated how nanoplastics made from polystyrene (PS) and poly vinyl chloride (PVC) behave in human plasma and tested their ability to cross the BBB.

The researchers utilized a novel approach by embedding gadolinium, a rare earth metal, into the nanoplastics, allowing precise tracking and quantification of their movement and transformation within the human body.
The team found that upon exposure to human plasma, nanoplastics rapidly attract a variety of biomolecules, immediately forming a "biological corona" that affects their behavior and interactions with cells.

The study demonstrated that both PS and PVC nanoplastics could cross the BBB, with PVC particles showing a higher penetration rate. However, the presence of a biological corona significantly reduced the amount of nanoplastics entering the brain.

The human blood-brain barrier (BBB) consists of a tightly packed layer of endothelial cells, surrounded by astrocytes and pericytes that restricts the passage of a variety of molecules and substances from the blood to the brain.

According to the researchers, the penetration of nanoplastics through the BBB highlights the need for further research on their potential neurotoxicity and long-term effects on human health.

 Fazel Abdolahpur Monikh et al, Biotransformation of nanoplastics in human plasma and their permeation through a model in vitro blood-brain barrier: An in-depth quantitative analysis, Nano Today (2024). DOI: 10.1016/j.nantod.2024.102466

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 7:33am

The researchers worried, however, that uneven distribution of the nanoparticles within the tissues might trigger overheating where the particles congregated, which could lead to tissue damage and toxicity from the cryoprotective agent at elevated temperatures.

To reduce these risks, the researchers have continued their investigation, working on a two-stage approach that more finely controls nanowarming rates. They describe this process:

Cultured cells or animal tissues were immersed in a solution containing magnetic nanoparticles and a cryoprotective substance and then frozen with liquid nitrogen.
In the first stage of thawing, as before, an alternating magnetic field initiated rapid rewarming of animal tissues.
As the samples approached the melting temperature of the cryoprotective agent, the researchers applied a horizontal static magnetic field.
The second field realigned the nanoparticles, effectively tapping the brakes on heat production.
The heating slowed fastest in areas with more nanoparticles, which dampened concerns about problematic hotspots. Applying the method to cultured human skin fibroblasts and to pig carotid arteries, the researchers noted that cell viability remained high after rewarming over a few minutes, suggesting the thawing was both rapid and safe.

The ability to finely control tissue rewarming moves us one step closer to long-term organ cryopreservation and the hope of more life-saving transplants for patients, the researchers say.

 Sangmo Liu et al, Magnetic-Nanorod-Mediated Nanowarming with Uniform and Rate-Regulated Heating, Nano Letters (2024). DOI: 10.1021/acs.nanolett.4c03081

Part 2

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 7:32am

Scientists use magnetic nanotech to safely rewarm frozen tissues for transplant

Every day, people die waiting for an organ transplant. Time is at a premium, not just for those awaiting organs, but also for the organs themselves, which can deteriorate rapidly during transportation.

Looking to extend the viability of human tissues, researchers report inNano Letters their efforts to facilitate completely freezing, rather than cooling and then thawing, potentially life-saving organs. They demonstrate a magnetic nanoparticle's successful rewarming of animal tissues.

Several people annually will die before receiving an organ transplant. One reason is the loss of organs in cold storage during transportation when delays cause them to warm prematurely. 

Methods have been developed to quickly freeze organs for longer-term storage without risking damage from ice crystal formation, but ice crystals can also form during warming. To address this problem, scientists advanced a technique known as nanowarming, pioneered by collaborator John Bischof, to employ magnetic nanoparticles and magnetic fields to thaw frozen tissues rapidly, evenly and safely.

They developed magnetic nanoparticles—effectively extremely tiny bar magnets—that, when exposed to alternating magnetic fields, generated heat. And that heat rapidly thawed animal tissues stored at -238 degrees Fahrenheit (-150 degrees Celsius) in a solution of the nanoparticles and a cryoprotective agent.

Part 1

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 7:22am

New research has potential to speed up forensic analysis in sexual assault cases

Most women around the world don't report sexual assaults. One of the main reasons is  that they don't have confidence in the justice system—and that lack of confidence was partly because of how long the process takes.

A new approach could mitigate one of the reasons victims are reluctant to report assaults: the perception that analysis of forensic evidence is too slow.

One of my friends, who is a forensic scientist, like others around the world , does this process very frequently:

Processing forensic evidence in sexual assault cases is a highly technical, multi-step process. Typically, DNA evidence is first collected from the victim, then sent to a well-equipped forensic laboratory for analysis by a skilled technician. Once there, the sample is first processed to isolate the assailant's DNA from the victim's; analysis of the assailant's DNA can then be conducted and used to identify a suspect.

The entire process can take days, weeks or longer. Most of that time is taken up with transporting the evidence to the lab; also, once at the lab, the speed with which the sample is analyzed depends on the number of other cases requiring analysis.

The researchers focused on the first step—that of separating the DNA of two individuals from a single sample. Currently, this can only be done manually by trained and experienced experts in a lab; i.e. there is no automated solution.

Researchers  have now developed  a process for separating two individuals' DNA employing a process called differential digestion technique using digital microfluidics. The new approach mitigates the current logistical and technical challenges.

The researchers simplified the process by reducing the number of manual steps needed to isolate the assailant's DNA from 13 to five. Also, because micro-fluidic processes tend to be faster, they expect that one of the eventual benefits will be shortening the overall time needed.

What's more, the new approach could lead to a mobile solution that doesn't require a lab. For example, testing could be done at a hospital where a victim would typically be taken in a sexual assault case—thereby eliminating the time necessary for the sample to reach the lab and circumventing the lab's queue.

The new technique is compatible with the technology known as Rapid DNA Analysis, already in use for the second step of identifying an individual from their DNA. According to the authors, the long term goal would be to integrate the two technologies to make the process even more streamlined.

Toward Analysis at the Point of Need: A Digital Microfluidic Approach to Processing Multi-Source Sexual Assault Samples, Advanced Science (2024). DOI: 10.1002/advs.202405712

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