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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

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 7:11am

No link between cellphone use, brain cancer, major report finds

A new international review finds no link between cellphone use and brain cancer.

Commissioned by the World Health Organization (WHO), the review included 11 experts from 10 countries who sifted through decades of research—5,000 studies published between 1994 and 2022 to be exact. The final analysis was published in the journal Environmental International.

The researchers  were trying to determine whether greater exposure to radio frequencies commonly used by wireless electronics, including cellphones, might up the chances of a brain cancer diagnosis.

 In the 63 studies they honed in on, the risk of brain cancer did not increase, even with prolonged cellphone use (defined as 10 years or more), among those who spent a lot of time on their cellphones, or for people who made a lot of calls. They also saw no increased risks of leukemia or brain cancer in children exposed to radio or TV transmitters or cellphone towers.

The problem with some of the early research that showed a relation was that it relied on case-control studies that compared the responses of people with brain cancer against those without the disease—which can be "somewhat biased."

Not only that, but newer generation cellphone networks, including 3G and 4G networks, actually produce "substantially lower" radio frequency emissions than older networks.

There are no major studies yet of 5G networks, but there are studies of radar, which has similar high frequencies; these do not show an increased risk.

They also noted that having more cellphone towers actually reduces the amount of radiation emitted from cellphones, because they don't have to work as hard to get a signal.

Worries about the health effects of new technology are common and tend to increase when a new technology is adopted widely or adopted quickly. 

This study tries to calm these shaken nerves.

The National Cancer Institute has more on cellphones and cancer risk.

Ken Karipidis et al, The effect of exposure to radiofrequency fields on cancer risk in the general and working population: A systematic review of human observational studies – Part I: Most researched outcomes, Environment International (2024). DOI: 10.1016/j.envint.2024.108983

Comment by Dr. Krishna Kumari Challa on September 5, 2024 at 7:04am

Scientists use AI to unlock protein structures of hundreds of viruses for the first time

Scientists are pioneering the use of machine-learning artificial intelligence software to investigate viruses, revealing never-before-seen viral mechanisms which yield immediate fundamental insights and pave the way for vaccine development.

The research uses AI protein structure prediction to examine hundreds of species in the Flaviviridae, a large family of viruses that cause diseases such as Dengue, Zika and Hepatitis C. 

The work demonstrates a 'super-charging' of the scientific investigation into the evolution of viral proteins, uncovering the critically important entry mechanisms which explain how viruses get into the body and replicate in cells. This research not only provides various key biological insights, but also marks one of the first systematic applications of protein structure prediction in virology, creating a resource for other investigators, and establishing a new paradigm for structure-informed exploration of virus evolution.

The AI technology, AlphaFold and ESMFold (developed by Google Deep Mind and Meta), was used to discover and classify the entry proteins of all the viruses tested—something which would be impossible to do with traditional methods.

The research authors think the study to be an important step forward for future pandemic preparedness and current viral threats such as Mpox, for which scientists currently know very little about the entry proteins.

The researchers now want to use this technology to scale up their research to thousands of viruses. By doing this we can build foundational knowledge to inform our responses to existing and new viral diseases.

Mapping glycoprotein structure reveals Flaviviridae evolutionary history, Nature (2024). www.nature.com/articles/s41586-024-07899-8

Comment by Dr. Krishna Kumari Challa on September 4, 2024 at 8:51am

Hot flushes are associated with cardiovascular risk: Study

Severe, lasting hot flushes during menopause are associated with atherosclerosis in the coronary artery, new research from Karolinska Institutet and Linköping University and published in the Journal of the American Heart Association reveals.

Forty percent of the women who participated in the study and who reported severe hot flushes also had atherosclerosis of the coronary artery, a condition that entails a higher risk of myocardial infarction. In the group of women who reported no or only mild discomfort, the corresponding figure was  30%.

These  findings support the hypothesis that there's an association between hot flushes and an elevated risk of cardiovascular disease.

Sigrid Nilsson et al, Menopausal Vasomotor Symptoms and Subclinical Atherosclerotic Cardiovascular Disease: A Population‐Based Study, Journal of the American Heart Association (2024). DOI: 10.1161/JAHA.123.033648

Comment by Dr. Krishna Kumari Challa on September 4, 2024 at 8:44am

Inflammation imprints lasting effects on intestinal stem cells 

Scientists  have discovered that inflammation in the gut leaves long-term marks on intestinal stem cells (ISCs) that reduce their ability to heal the intestine, even after inflammation has receded. This is important because it affects ISCs' response to future challenges. The study appears in Cell Stem Cell.

GVHD is an inflammatory reaction in which immune T cells from the bone marrow transplant donor attack the host gut cells, mainly ISCs.

Although many ISCs perish during GVHD, survivors remain. However, it's not known whether they are fully functional or can return to their full functionality after the resolution of GVHD, which has fundamental implications for host resilience and repair.

In the current study, researchers investigated the consequences of inflammation on ISCs in well-defined clinically relevant models of GVHD.

Using cellular and animal models, they found that exposure to inflammation drove ISCs to change their metabolism in ways that resulted in the accumulation of succinate, a product of cellular processes, which in turn reprogramed the epigenome.

The epigenome is a system of chemical marks on the DNA that regulates the genes expressed by the cell. Inflammation-led epigenome reprogramming changed the expression of genes involved in cell reproduction. Overall, reprogrammed ISCs were less capable of regenerating, a first step toward healing the intestine.

They then investigated whether ISCs would be able to recuperate their regenerative ability after inflammation had resolved.

They found that ISCs had not overcome their initial exposure to inflammation. Despite mitigating GVHD inflammation for 28 days, ISCs retained a reduced regenerative capacity that led to poor recovery and increased mortality from challenges, such as non-lethal radiation exposure, in animal models. More research is on the way to design strategies to help ISCs 'forget' their encounter with inflammation and enhance their resilience against immune attacks.

 Dongchang Zhao et al, Inflammation-induced epigenetic imprinting regulates intestinal stem cells, Cell Stem Cell (2024). DOI: 10.1016/j.stem.2024.08.006

Comment by Dr. Krishna Kumari Challa on September 4, 2024 at 8:35am

Eye movements can create different versions of the same film in our heads

Picture two people sitting in a movie theater, both watching the screen: Are they seeing the same thing? Or is the movie playing out differently in each of their minds? Researchers from the Justus Liebig University Giessen (JLU) have found that it's the latter, and they've published their findings in the journal Proceedings of the National Academy of Sciences. It turns out that viewers experience different versions of the same film in their brains, and these differences can be predicted by their unique eye movements.

Just like our bodies are made up of the same basic parts but vary from person to person, the same is true for our brains and their activity patterns. Neuroscientists use functional magnetic resonance imaging and machine learning to make these brain activity patterns comparable across individuals. For about a decade now, these techniques have allowed researchers to "translate" activation patterns among different brains.

Researchers  used this technology to explore how individual eye movements affect our perception. They examined how well one person's brain activity could predict another's while 19 volunteers watched the same movie—either freely or while passively staring at the center of the screen. Compared to passive viewing, natural eye movements led to much stronger activation in the brain's visual centers. However, these activations were also more individual, making it harder to match one person's brain activity to another's.

Recent research shows that eye movements are as unique as personality traits. Some people focus more on faces, while others are drawn to text or other elements.

These individual viewing habits might create a unique 'world' in each person's mind. Now we know that's true. We could even predict how different the brain activity patterns would be between people by measuring the similarity of their eye movements in a separate experiment conducted days apart.

It's fascinating that while eye movements lead to stronger neural activity, they also make these activity patterns less comparable between individuals. Usually, a stronger signal means clearer data, but here the signal—the brain's representation of the movie—is different for each person, like a director's cut prepared by the individual brain.

The research  team is now exploring how eye movements develop over a person's lifetime and how they affect our understanding of scenes and daily tasks.

It makes you wonder—next time you're in the cinema, you might want to ask the person next to you, 'Which movie did you see?'

Hmmm! Now I know that you are not seeing what I am really doing! 

Petra Borovska et al, Individual gaze shapes diverging neural representations, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405602121

Comment by Dr. Krishna Kumari Challa on September 4, 2024 at 8:26am

Colorful, melodious birds at risk from poor urban planning

 Recent research reveals how urban areas  are losing bird species with characteristics that people find most "aesthetically pleasing."

The study found 82 different bird species across 42 different landscape types in Brisbane, but the variety of smaller, colorful, "melodious" bird species decreased in areas where there were not enough green spaces and fragmented landscapes. 

The findings are published in the journal Landscape Ecology in a paper titled "Landscape structure influences the spatial distribution of urban bird attractiveness."

These outcomes highlighted the importance of designing urban landscapes in future developments that increased opportunities to find colorful and melodious birds and favor people's connection with nature.

Beauty can be subjective, but several studies have demonstrated that traits such as color, size and shape favor positive feelings and perceptions of species as beneficial. Attractive' traits could even influence human preferences toward conserving species and support education and fundraising.

The results show that some species like the Scarlet Honeyeater (Myzomela sanguinolenta) and the Yellow-faced Honeyeater (Lichenostomus chrysops) were lost in highly urbanized environments.

When the number of species was low, landscapes could support some species that are considered "attractive" based on their traits, such as the (Rainbow Lorikeet Trichoglossus haematodus and Willie Wagtail Rhipidura leucophrys).

However, the overall attractiveness of a variety of different species could decline, as small-bodied, colorful and melodious species were negatively affected by built infrastructure and fragmentation.

It corresponded with the loss of species with high attractiveness values, such as small-bodied forest-dependent species that tended to be more vulnerable to urbanization (White-throated Gerygone Gerygone olivace and Australian Golden Whistler Pachycephala pectoralis).

Urban planning should consider how to bring back vibrant, colorful birdlife to our cities, enriching our daily lives and reconnecting us with nature in the very places we live and work, say the researchers.

There are relatively easy fixes like creating green corridors and adding diverse vegetation in parks and gardens. These strategies can provide key habitats for many colorful species with a high diversity of calls."

This information could help to track the success of initiatives that seek to achieve wins for both biodiversity and human well-being, and it could lead to greater support for conservation and positive human health outcomes.

Andres F. Suarez-Castro et al, Landscape structure influences the spatial distribution of urban bird attractiveness, Landscape Ecology (2024). DOI: 10.1007/s10980-024-01950-9

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