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Comment by Dr. Krishna Kumari Challa on May 30, 2025 at 10:10am

Researchers say emulsifiers may cause a variety of health problems

The difference between commerce and science: Commerce wants to sell its products by showing you eye and attention catching ads and videos, while  science tries to see what lies behind the masks and makes people alert. 

Which one do you listen to and which one do you follow?

Ice cream that resists melting. Great, you would think and buy  the thing that  can make this possible.

'But, wait', says science. Why?

This is the actual scene playing out before you:

 In a video explaining the science behind it, a seller of food chemicals shows scoops of ice cream holding their shape under hot lights. The super ingredient? Polysorbate 80.

Polysorbate 80 is an emulsifier, a chemical used to control the consistency of thousands of supermarket products. Other widely used emulsifiers or stabilizers include carboxymethyl cellulose, carrageenan, and maltodextrin.

Emulsifiers and thickening agents play an important role in improving food texture and consistency.

Recently, such ingredients have been showing up in scientific studies for another reason: Researchers say they may cause a variety of health problems.

Studies have found that emulsifiers can alter the mix of bacteria in the gut, known as the microbiome or microbiota; damage the lining of the gastrointestinal tract; and trigger inflammation, potentially contributing to problems elsewhere in the body.

Emulsifiers and stabilizers are among the most common ingredients in ultraprocessed foods. But could you ban them?

This is the complexity of the war on food additives. 

The researchers show how, when it comes to food science, regulators are chronically playing catch-up. In the meantime, for many ingredients, regulators and consumers alike are left in a gray zone between suspicion and proof of harm in humans.

Emulsifiers' assault on the microbiome could help explain inflammatory bowel diseases such as Crohn's disease and ulcerative colitis, metabolic disorders, and even cancer, the studies suggest.

"There is a lot of data showing that those compounds are really detrimental to the microbiota and that we should stop using them," say the several studies on them.

But solid proof?!

Yet much larger and more ambitious clinical trials in humans are needed to get it.

Wait, we  some evidence from doctors and patients. 

For people who  suffered from gastrointestinal illness, the research fits their own experience as a consumer. Changing their diet to avoid emulsifiers has made a shocking difference, easing symptoms that were debilitating. 

Clinically, many patients have reported an improvement in symptoms with such changes, say the gastroenterologists.

Part 1

Comment by Dr. Krishna Kumari Challa on May 30, 2025 at 9:02am

Previous studies have shown reproduction-like behaviors such as polymerization-induced self-assembly (PISA) in micelles and vesicles. However, these processes were neither biochemistry-free nor did they demonstrate true autonomous self-reproduction.

To explore the unknown, the team designed a one-pot PISA batch reactor consisting of strictly non-biochemical molecules with an aim to synthesize amphiphiles that can self-organize, self-assemble, and self-initiate into chemically active entities.

The reaction vial included an aqueous solution of a hydrophilic polymer with a hydrophobic chain transfer agent molecule (CTA) attached to its end, along with the monomer to be polymerized and a photocatalyst in a nitrogen-filled inert environment. This mixture was then allowed to sit under green LED light for 90 minutes at 33°C.

They observed that the mixture of chemicals undergoes photo-Reversible Addition-Fragmentation Chain Transfer (RAFT) photopolymerization in water to transform the starting molecules into amphiphilic block copolymers. These block copolymers then gave rise to non-biochemical polymer vesicles or synthetic cells that displayed self-reproduction behavior via PISA.

The vesicles not only formed and sustained themselves but also released polymeric "spores" that seeded a nonlinear, exponential increase in vesicle numbers, with each new generation inheriting certain properties from their "parent" vesicles.

The behavior shown in this study mimics self-reproduction—a key feature of living systems—arising from simple chemistry without the need for complex biochemical processes.

The researchers note that the findings not only offer insights into how life might have begun but also open new possibilities for creating a wide range of abiotic, life-like systems.

Sai Krishna Katla et al, Self-reproduction as an autonomous process of growth and reorganization in fully abiotic, artificial and synthetic cells, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2412514122

Part 2

Comment by Dr. Krishna Kumari Challa on May 30, 2025 at 9:02am

Artificial cell-like structures mimic self-reproduction and release polymeric spores

Life on Earth possesses an exceptional ability to self-reproduce, which, even on a simple cellular level, is driven by complex biochemistry. But can self-reproduction exist in a biochemistry-free environment?

A study by researchers  demonstrated that the answer is yes.

The researchers designed a non-biochemical system in which synthetic cell-like structures form and self-reproduce by ejecting polymeric spores.

The PNAS paper reports a one-pot reaction in which chemically active polymer protocells began their journey as a uniform mixture of molecules that usually do not self-assemble. However, when placed under green light (530 nm), they formed vesicle-like structures that grew and divided as the reaction proceeded.

Living organisms produce offspring from their own cellular material, giving rise to new, independent life forms which interact with their environment to obtain food, energy, and information needed for survival. If all goes well, the internal chemical networks of these new systems also enable them to self-reproduce, leading to future generations. As Rudolf Virchow, father of cellular pathology, stated in 1858, "every cell comes from a pre-existing cell."

In biochemistry-based life, even single-celled organisms like bacteria depend on a chain of well-coordinated complex chemical processes to run the life-sustaining processes and reproduction.

It is known that biochemistry is sufficient for driving self-reproduction, but is it essential? Or can we build artificial, compartmentalized chemical systems in the lab that can self-assemble and reproduce on their own?

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 2:02pm

By elucidating the neural basis of individual differences in fear plasticity, this study highlights the central role of brain states in stress adaptation.

Xuemei Liu et al, Neural circuit underlying individual differences in visual escape habituation, Neuron (2025). DOI: 10.1016/j.neuron.2025.04.018

Part 2

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 1:47pm

Neural circuit mechanism may explain why people have different fear levels

In a study published in Neuron, a research team revealed the neural circuit underlying individual differences in visual escape habituation.

Emotional responses, such as fear behaviors, are evolutionarily conserved mechanisms that enable organisms to detect and avoid danger, ensuring survival. Since Darwin's "On the Origin of Species" (1859) proposed that individual differences drive natural selection, understanding behavioral adaptation has become essential for unraveling biodiversity and survival strategies.

Repeated exposure to predators can elicit divergent coping strategies—habituation or sensitization—that are dependent on sensory inputs, internal physiological states, and prior experiences. However, the neural circuits underlying individual variability in the regulation of internal states and habituation to repeated threats remain poorly understood.

To address this question, researchers employed advanced techniques such as in vivo multichannel recording, fiber photometry, pupillometry and optogenetic manipulation to investigate how individual differences in arousal and internal states influence visual escape habituation.

Researchers found that distinct subcortical pathways from the superior colliculus to the amygdala and insula cortical pathways that govern two visual escape behaviors in two groups of mice. They identified two distinct defensive behaviors—sustained rapid escape (T1) and rapid habituation (T2).

T1 involves the superior colliculus (SC)/insular cortex-ventral tegmental area (VTA)-basolateral amygdala (BLA) pathway, whereas T2 relies on the SC/insula-dorsomedial thalamus (MD)-BLA circuit. The MD integrates inputs from the SC and insula to regulate arousal and fear responses, while beta oscillations in BLA modulate fear states.
Dysregulation of innate fear circuits is closely linked to many mental health conditions, including phobias, anxiety, and post-traumatic stress disorder (PTSD). Elucidating the neural circuitry underlying innate fear not only enhances our understanding of emotional disorders but also provides promising therapeutic targets for clinical interventions.

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 1:43pm

Intestinal bacteria influence aging of blood vessels

The aging of the innermost cell layer of blood vessels leads to cardiovascular diseases. Researchers at UZH have now shown for the first time that intestinal bacteria and their metabolites contribute directly to vascular aging.

As people age, the bacterial composition in their gut changes, resulting in fewer "rejuvenating" and more harmful substances in the body.

Cardiovascular diseases are the most common cause of death worldwide. Even if known traditional risk factors such as diabetes or high blood pressure are treated, the disease worsens in half of all cases, especially in older patients.

In a study published in Nature Aging, researchers at UZH have now shown for the first time that intestinal bacteria and their metabolites can accelerate the aging of blood vessels and trigger cardiovascular disease.

The human body consists of around 30 to 100 trillion bacteria that reside in our organs. Ninety percent of these bacteria live in the intestine, processing the food we eat into metabolic products, which in turn affect our bodies.

Half of these substances have not yet been recognized. 

Using data from more than 7,000 healthy individuals aged between 18 and 95 as well as a mouse model of chronological aging, the researchers found that the breakdown product of the amino acid phenylalanine—phenylacetic acid—accumulates with age.

In several series of experiments, researchers were able to prove that phenylacetic acid leads to senescence of endothelial cells, in which the cells that line the inside of blood vessels do not proliferate, secrete inflammatory molecules, and exhibit an aging phenotype. As a result, the vessels stiffen up and their function is impaired.

By conducting a comprehensive bioinformatic analysis of the microbiome of mice and humans, the researchers were able to identify the bacterium Clostridium sp.ASF356, which can process phenylalanine into phenylacetic acid.

When the researchers colonized young mice with this bacterium, they subsequently showed increased phenylacetic acid levels and signs of vascular aging. However, when the bacteria were eliminated with antibiotics, the concentration of phenylacetic acid in the body decreased.

However, the microbiome in the gut also produces substances that are beneficial to vascular health. Short-chain fatty acids such as acetate, which are produced by fermentation of dietary fibers and polysaccharides in the intestine, act as natural rejuvenating agents.

The research group used in-vitro experiments to show that adding sodium acetate can restore the function of aged vascular endothelial cells. When analyzing intestinal bacteria, they found that the number of bacteria that produce such rejuvenating agents decreases with age.

"The aging process of the cardiovascular system can therefore be regulated via the microbiome", say the researchers.

The researchers are also working on ways to reduce phenylacetic acid in the body through medication.

Seyed Soheil Saeedi Saravi et al, Gut microbiota-dependent increase in phenylacetic acid induces endothelial cell senescence during aging, Nature Aging (2025). DOI: 10.1038/s43587-025-00864-8

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 12:14pm

Earth's magnetic field typically deflects the majority of these blasts of charged particles, but during periods of intense activity, some manage to get through. Merging of the magnetic fields in the solar wind, arriving from the sun as a result of the expansion of its atmosphere into space, with the magnetic fields of Earth inject energy into near-Earth space and power space weather and the dancing northern (and southern) lights.

In order to generate the aurora, accelerated particles, mostly electrons, rain down towards Earth and then collide with atoms and molecules in the upper atmosphere, between 100 and 250 kilometers above Earth's surface. In the period after these collisions, when the particles drop back down into a lower-energy state, "they spit out a photon of light."
You have these energy conversion processes occurring at the solar surface, but then you also have something similar occurring in Earth's magnetic field. That's ultimately the origin of the energy for accelerating the charged particles that rain into Earth's atmosphere and cause this sort of glowing effect.
The palette of brilliant colors we see from the ground is a result of different gases involved in the collisions. Green, by far the most common hue, comes from particles colliding with oxygen atoms. Higher-energy collisions involving oxygen can have a red hue, and nitrogen is the gas responsible for blue and purple-tinted displays.
Part 2

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Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 12:10pm

Science behind the surge in northern lights

If you feel like you've seen more of the northern lights painting the night sky lately, you'd be right. 

We're currently in a period of solar maximum, which is good news for aurora borealis enthusiasts. If you want to watch beautiful shows of the dancing northern lights, solar max is an ideal time to do that, say the experts.

The sun operates on a roughly 11-year cycle of magnetic activity. 

As the sun's magnetic field flips its north and south poles over this time, it switches between periods of lower magnetic activity (solar minimum) and periods of higher magnetic activity (solar maximum).

Surrounding the north and south magnetic poles of Earth are regions referred to as the "auroral ovals"—areas where aurora displays typically happen. During periods of solar max, these zones tend to expand a bit closer towards the equator, moving into areas where more people live.

There's more energy available, so they're more powerful, but they also move so they're at locations where they're more visible. 

Before any colors appear in the night skies over Earth, things need to turn explosive—literally—on the sun. The sun's surface is permeated by bundles of strong magnetic fields which poke out into the solar atmosphere. The ends of such magnetic loops represent cooler regions of the solar surface called sunspots. 

Loops can be stable for days and then suddenly they'll explode and launch a whole mass of charged particles into space—that's called a coronal mass ejection. It's basically a rapid release of the energy in these magnetic loops, but in the form of charged particles, which get a lot of kinetic energy and exceed the escape velocity of the sun's gravity field, blasting outwards into the solar system. 

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 11:50am

Filtered car emissions still turn toxic after sunlight exposure, study reveals

A new international study reveals that emissions from modern gasoline cars—despite meeting the currently strictest European emission standards EURO 6d—can become significantly more harmful after being released into the atmosphere. The findings, published in Science Advances, challenge the assumption that filtered exhaust from EURO 6d-compliant vehicles is inherently safe.

The research focused on a gasoline vehicle equipped with a gasoline particulate filter (GPF), designed to drastically reduce primary particulate emissions. Freshly emitted exhaust showed no detectable cytotoxic effects on human lung cells. However, once the exhaust underwent "photochemical aging"—a natural transformation process driven by sunlight and atmospheric oxidants—it became substantially more toxic.

The aged emissions caused notable DNA damage and oxidative stress in both cancerous alveolar and normal bronchial epithelial cells. This toxicity was not only associated with newly formed particles, known as secondary organic and inorganic aerosols (SOA and SIA), but also with oxygenated volatile compounds, such as carbonyls, generated during their residence in the atmosphere.

 These findings point to a critical shortfall in current vehicle emissions testing and regulation.

While EURO 6d standards ensure low emissions at the tailpipe, they do not account for the chemical transformations those emissions undergo once released into the environment.

This new study shows that we are missing a big part of the picture by not considering how exhaust gases change—and become more harmful—after they leave the car.

The results have important implications for how air quality standards are set and monitored. Current regulations focus primarily on the emissions measured directly after combustion, without factoring in how these emissions interact with sunlight and atmospheric chemicals to form new, more harmful pollutants.

Mathilde N. Delaval et al, The efficiency of EURO 6d car particulate filters is compromised by atmospheric aging: In vitro toxicity of gasoline car exhaust, Science Advances (2025). DOI: 10.1126/sciadv.adq2348

Comment by Dr. Krishna Kumari Challa on May 29, 2025 at 11:34am

Humans are seasonal creatures, according to our circadian rhythms

It's natural to think that, with our fancy electric lights and indoor bedrooms, humanity has evolved beyond the natural influence of sunlight when it comes to our sleep routines.

But new research  shows that our circadian rhythms are still wild at heart, tracking the seasonal changes in daylight. Humans really are seasonal, even though we might not want to admit that in our modern context. 

Day length, the amount of sunlight we get,  really influences our physiology. The study shows that our biologically hardwired seasonal timing affects how we adjust to changes in our daily schedules.

This finding could enable new ways to probe and understand seasonal affective disorder, a type of depression that's connected to seasonal changes. It could also open new areas of inquiry in a range of other health issues that are connected to the alignment of our sleep schedules and circadian clocks.

Researchers have previously shown that our moods are strongly affected by how well our sleep schedules align with our circadian rhythms. 

This work may have deeper implications for mental health issues, like mood and anxiety, but also metabolic and cardiovascular conditions as well.

The research also showed there is a genetic component of this seasonality in humans, which could help explain the vast differences in how strongly individuals are affected by changes in day length.

For some people they might be able to adapt better, but for other people it could be a whole lot worse.

Exploring this genetic component will help researchers and doctors understand where individuals fall on that spectrum, but getting to that point will take more time and effort. For now, this study is an early but important step that reframes how we conceive of human circadian rhythms.

A lot of people tend to think of their circadian rhythms as a single clock. What  the researchers are showing is that there's not really one clock, but there are two. One is trying to track dawn and the other is trying to track dusk, and they're talking to each other.

The fact that circadian rhythms  in people exhibited a seasonal dependence is a compelling argument for just how hardwired this feature is in humans, which isn't altogether surprising, the researchers say.

Seasonal timing and interindividual differences in shiftwork adaptation, npj Digital Medicine (2025). DOI: 10.1038/s41746-025-01678-z

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