Comment

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 11:18am

Tire toxicity faces fresh scrutiny after fish fatalities

For decades, concerns about automobile pollution have focused on what comes out of the tailpipe. Now, researchers and regulators say, we need to pay more attention to toxic emissions from tires as vehicles roll down the road.

At the top of the list of worries is a chemical called 6PPD, which is added to rubber tires to help them last longer. When tires wear on pavement, 6PPD is released. It reacts with ozone to become a different chemical, 6PPD-q, which can be extremely toxic—so much so that it has been linked to repeated fish kills in the US.

The trouble with tires doesn't stop there. Tires are made primarily of natural rubber and synthetic rubber, but they contain hundreds of other ingredients, often including steel and heavy metals such as copper, lead, cadmium, and zinc.

As car tires wear, the rubber disappears in particles, both bits that can be seen with the naked eye and microparticles. Testing by a British company, Emissions Analytics, found that a car's tires emit 1 trillion ultrafine particles per kilometer driven—from 5 to 9 pounds of rubber per internal combustion car per year.

And what's in those particles is a mystery, because tire ingredients are proprietary. You've got a chemical cocktail in these tires that no one really understands and is kept highly confidential by the tire manufacturers.

Regulators have only begun to address the toxic tire problem, though there has been some action on 6PPD.

Native American tribes have petitioned the Environmental Protection Agency to prohibit the chemical. The EPA said it is considering new rules governing the chemical. "We could not sit idle while 6PPD kills the fish that sustain us", they say.

But, tragically,  today there is no alternative to 6PPD.

One outstanding research question is whether 6PPD-q affects people, and what health problems, if any, it could cause. A study published in Environmental Science & Technology Letters found high levels of the chemical in urine samples from a region of South China, with levels highest in pregnant women.

The discovery of 6PPD-q, Molden said, has sparked fresh interest in the health and environmental impacts of tires.

Source: Environmental Science & Technology Letters

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 10:59am

Plastic particle air pollution is now pervasive and inhalation ranks as the second most likely pathway for human exposure.
The primary types are intentionally manufactured, including a wide array of cosmetics and personal care products such as toothpaste.

The secondary ones are fragments derived from the degradation of larger plastic products, such as water bottles, food containers and clothes.
Extensive investigations have identified synthetic textiles as a principal source of indoor airborne plastic particles, while the outdoor environment presents a multitude of sources encompassing contaminated aerosols from the ocean to particles originating from wastewater treatment.
Researchers' modelling found that breathing rate along with particle size and shape determined where in the respiratory system plastic particles would be deposited.

Faster breathing rates led to heightened deposition in the upper respiratory tract, particularly for larger microplastics, whereas slower breathing facilitated deeper penetration and deposition of smaller nanoplastic particles.
Particle shape was another factor, with non-spherical microplastic particles showing a propensity for deeper lung penetration compared to spherical microplastics and nanoplastics, potentially leading to different health outcomes.

These findings highlight the imperative consideration of breathing rates and particle sizes in health risk assessments associated with respiratory exposure to nano and microplastic particles.

Xinlei Huang et al, Transport and deposition of microplastics and nanoplastics in the human respiratory tract, Environmental Advances (2024). DOI: 10.1016/j.envadv.2024.100525

Part 2

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 10:56am

The journey of inhaled plastic particle pollution

With recent studies having established the presence of nano and microplastic particles in the respiratory systems of both human and bird populations, a new study has modeled what happens when people breathe in different kinds of plastic particles and where they end up.

Researchers used computational fluid-particle dynamics (CFPD) to study the transfer and deposition of nano and microplastic particles of different sizes and shapes depending on the rate of breathing.

The results of the modeling, published in the journal Environmental Advances, have pinpointed hotspots in the human respiratory system where plastic particles can accumulate, from the nasal cavity and larynx and into the lungs. The paper based on these results is titled, "Transport and deposition of microplastics and nanoplastics in the human respiratory tract."

Evidence 's mounting on the significant impact of nano and microplastics on respiratory health and the UTS study would provide essential insights for the development of targeted strategies to mitigate potential risks and ensure effective health interventions.
Experimental evidence has strongly suggested that these plastic particles amplify human susceptibility to a spectrum of lung disorders, including chronic obstructive pulmonary disease, fibrosis, dyspnea (shortness of breath), asthma, and the formation of what are called frosted glass nodules.
Part 1

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 10:06am

The scientists looked for connections the brain might have with inflammation and innate immunity, the defense system shared by all animals and the most ancient component of the immune system. Whereas the adaptive immune system remembers previous encounters with intruders to help it resist them if they invade again, the innate immune system attacks anything with common traits of germs. The relative simplicity of innate immunity lets it respond to new insults more quickly than adaptive immunity.

Prior studies in humans revealed that electrically stimulating the vagus nerve—a bundle of thousands of nerve fibers linking the brain and the body's internal organs—could reduce the response linked to a specific inflammatory molecule.
However, much remained unknown about the nature of this body-brain system: for instance, the generality of the brain's modulation of immunity and the inflammatory response, the selective lines of communication between the body and the brain, the logic of the underlying neural circuit, and the identity of the vagal and brain components that monitor and regulate inflammation.
Researchers turned to a bacterial compound that sets off innate immune responses. The scientists found that giving this molecule to mice activated the caudal nucleus of the solitary tract, or cNST, which is tucked inside the brainstem. The cNST plays a major role in the body-brain axis and is the primary target of the vagus nerve.
The scientists showed that chemically suppressing the cNST resulted in an out-of-control inflammatory response to the immune insult: levels of pro-inflammatory molecules released by the immune system were more than three times higher than usual, and levels of anti-inflammatory immune compounds were roughly three times lower than normal.

In contrast, artificially activating the cNST reduced pro-inflammatory molecule levels by nearly 70% and increased anti-inflammatory chemical levels almost tenfold.

Similar to a thermostat, this newfound brain circuit helps increase or decrease inflammatory responses to keep the body responding in a healthy manner.

A body–brain circuit that regulates body inflammatory responses, Nature (2024). DOI: 10.1038/s41586-024-07469-y

Part 2

**

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 10:04am

Scientists identify new brain circuit in mice that controls body's inflammatory reactions

The brain can direct the immune system to an unexpected degree, capable of detecting, ramping up and tamping down inflammation, shows a new study in mice by  researchers.

The brain is the center of our thoughts, emotions, memories and feelings. Thanks to great advances in circuit tracking and single-cell technology, we now know the brain does far more than that. It is monitoring the function of every system in the body.

Future research could identify drugs that can target this newfound brain circuit to help treat a vast range of disorders and diseases in which the immune system goes haywire. This new discovery could provide an exciting therapeutic venue to control inflammation and immunity.

Recent work by scientists is revealing the importance of the body-brain axis, a vital pathway that conveys data between the organs and the brain. For example, they discovered that sugar and fat entering the gut use the body-brain axis to drive the craving and strong appetite for sugary and fatty foods.

They  found all these ways in which the body is informing the brain about the body's current state. 

Part 1

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 9:24am

The complementary structural and functional connectivity maps provide a neuroanatomic basis for integrating arousal and awareness in human consciousness. The researchers released the MRI data, brain mapping methods, and a new Harvard Ascending Arousal Network Atlas, to support future efforts to map the connectivity of human consciousness.

This connectivity results suggest that stimulation of the ventral tegmental area's dopaminergic pathways has the potential to help patients recover from coma because this hub node is connected to many regions of the brain that are critical to consciousness.
The human brain connections that they identified can be used as a roadmap to better understand a broad range of neurological disorders associated with altered consciousness, from coma, to seizures, to sudden infant death syndrome (SIDS).

The researchers are currently conducting clinical trials to stimulate the default ascending arousal network in patients with coma after traumatic brain injury, with the goal of reactivating the network and restoring consciousness.

 Brian Edlow et al, Multimodal MRI reveals brainstem connections that sustain wakefulness in human consciousness, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adj4303. www.science.org/doi/10.1126/scitranslmed.adj4303

Part 2

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 9:22am

Brain imaging study reveals connections critical to human consciousness

In a paper titled, "Multimodal MRI reveals brainstem connections that sustain wakefulness in human consciousness," published in Science Translational Medicine, a group of researchers at Massachusetts General Hospital and Boston Children's Hospital, created a connectivity map of a brain network that they propose is critical to human consciousness.

The study involved high-resolution scans that enabled the researchers to visualize brain connections at submillimeter spatial resolution. This technical advance allowed them to identify previously unseen pathways connecting the brainstem, thalamus, hypothalamus, basal forebrain, and cerebral cortex.
Together, these pathways form a "default ascending arousal network" that sustains wakefulness in the resting, conscious human brain. The concept of a "default" network is based on the idea that specific networks within the brain are most functionally active when the brain is in a resting state of consciousness. In contrast, other networks are more active when the brain is performing goal-directed tasks.

To investigate the functional properties of this default brain network, the researchers analyzed 7 Tesla resting-state functional MRI data from the Human Connectome Project. These analyses revealed functional connections between the subcortical default ascending arousal network and the cortical default mode network that contributes to self-awareness in the resting, conscious brain.

Part 1

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 9:15am

Their findings challenge previous assumptions about the backgrounds of RA, that overlooked the antibodies' diversity and complexity. This shows that RA is not just a disease occurring due to small errors, but a big structural problem in the immune system. 

The study also revealed that these ACPAs are extensively modified with sugar molecules, known as Fab glycans. Intriguingly, some antibodies had multiple sugar molecules attached. This is much more then researchers normally observe in antibody profiles.

Having extra glycans aboard, may help the ACPA antibodies pass the filter of the immune system. The immune system uses several very strict checks during antibody production, to make sure all antibodies are correct. Wrongly produced antibodies are then detected and removed. Scientists suspect that glycans could help ACPAs trick the control system, allowing ACPAs to pass through the filter and form the onset of RA.
Current efforts to develop treatments for RA are mainly geared towards eliminating autoantibodies directly. This strategy may not be effective, say the researchers. When you realize that there is such an extreme diversity in RA-related autoantibodies, it seems virtually impossible to eliminate them. A better approach may be to intervene earlier in the disease process, by targeting the malfunctioning filtering mechanism that allows autoantibodies to pass through.

Understanding these unique proteins is important, as it could ultimately also help doctors diagnose RA better. Even though RA remains an incurable disease, with an earlier diagnosis you can take better measures to control its progression.

Eva Maria Stork et al, Antigen-specific Fab profiling achieves molecular-resolution analysis of human autoantibody repertoires in rheumatoid arthritis, Nature Communications (2024). DOI: 10.1038/s41467-024-47337-x

Part 2

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 9:14am

Patients with rheumatoid arthritis have unique and complex autoantibody patterns, study reveals

Patients with rheumatoid arthritis (RA) all have a unique and diverse set of antibodies that are involved in the development of the disease. Researchers unveiled the complexity of these antibodies using powerful lab tools capable of analyzing our immune system at molecular levels. Their discovery suggests that current assumptions about the origin of RA are too simple. Their findings may point towards improved diagnostics.

Rheumatoid arthritis is a chronic autoimmune disease that primarily affects the joints, causing pain, stiffness, and swelling. It arises when the immune system mistakenly attacks the body's own tissues, leading to inflammation in the joints and potentially other organs.

The exact cause of RA remains unknown, but a crucial role is played by antibodies, special proteins made by the immune system to help fight off infections. They recognize and attack specific targets, like viruses or bacteria. Some antibodies are wrongly produced, causing them to attack our own body. Normally, our body's immune system is equipped with a 'filter' that cleans up these so-called autoantibodies. Researchers think that this mechanism is malfunctioning in RA patients.

The extend to which this filter is malfunctioning, now appears to be much greater than expected. Research  published in Nature Communications reveals that it's not just a handful of different RA-associated autoantibodies that evade the filter. On the contrary, the researchers found an extremely broad variety of these antibodies.

The team used novel mass spectrometry tools that profile specific antibodies typically seen in the blood of RA patients, which are called anti-citrullinated protein antibodies (ACPAs). They discovered that each RA patient possesses a unique and diverse set of ACPAs.

Part 1

Comment by Dr. Krishna Kumari Challa on May 2, 2024 at 9:06am

The difficulty lies in the fact that such a "second law" for quantum entanglement would require us to show that entanglement transformations can be made reversible, just like work and heat can be interconverted in thermodynamics.

It is known that reversibility of entanglement is much more difficult to ensure than the reversibility of thermodynamic transformations, and all previous attempts at establishing any form of a reversible theory of entanglement have failed. It was even suspected that entanglement might actually be irreversible, making the quest an impossible one.
In their new work, published in Nature Communications, the authors solve this long-standing conjecture by using probabilistic entanglement transformations, which are only guaranteed to be successful some of the time, but which, in return, provide an increased power in converting quantum systems.

Under such processes, the authors show that it is indeed possible to establish a reversible framework for entanglement manipulation, thus identifying a setting in which a unique entropy of entanglement emerges and all entanglement transformations are governed by a single quantity. The methods they used could be applied more broadly, showing similar reversibility properties also for more general quantum resources.
findings mark significant progress in understanding the basic properties of entanglement, revealing fundamental connections between entanglement and thermodynamics, and crucially, providing a major simplification in the understanding of entanglement conversion processes.
This not only has immediate and direct applications in the foundations of quantum theory, but it will also help with understanding the ultimate limitations on our ability to efficiently manipulate entanglement in practice.

Bartosz Regula et al, Reversibility of quantum resources through probabilistic protocols, Nature Communications (2024). DOI: 10.1038/s41467-024-47243-2

Part 2

• ‹ Previous
• 1
• …
• 205
• 206
• 207
• 208
• 209
• …
• 1053
• Next ›
• Page