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Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 11:13am

This Strange Crystal Has Two Melting Points

In 1896, German chemist Emil Fischer noted something very strange about a molecule named acetaldehyde phenylhydrazone. Identical batches of the crystalline compound appeared to have wildly different melting points.

Some batches, he found, melted at temperatures of around 65 degrees Celsius (149 Fahrenheit). Others at 100 degrees Celsius. It was, in a word, utterly bizarre. No other substance was known to behave this way. Nor should it.

According to the laws of thermodynamics that describe the way the physical world behaves, such a result should be impossible.

More than 120 years after Fischer's original discovery, in 2019, an international team of researchers led by chemist Terry Threfall of the University of Southampton in the UK finally found and published the answer. Fischer (who went on to win a 1902 Nobel prize for other work, so he was clearly no quack) had observed something real; but not, as it would turn out, anything that would break thermodynamics.

The culprit? An absolutely miniscule contamination, so small that it is all but undetectable. When acetaldehyde phenylhydrazone melts, it becomes one of two liquids, based on whether the compound has been exposed to a base or an acid. The former appears at the higher melting point; and the latter at the lower.

The observation of such behavior will be exceedingly rare because it depends on the molecules in the crystal and in the liquid having different geometries, which is unusual. Furthermore, it depends also on the conversion by acid being both possible and rapid.

Part 1

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 10:13am

Healthy women have cells that resemble breast cancer, study finds

A new study from cancer researchers   finds that, in healthy women, some breast cells that otherwise appear normal may contain chromosome abnormalities typically associated with invasive breast cancer. The findings question conventional thinking on the genetic origins of breast cancer, which could influence early cancer detection methods.

The study, published recently in Nature, discovered that at least 3% of normal cells from breast tissue in 49 healthy women contain a gain or loss of chromosomes, a condition known as aneuploidy, and that they expand and accumulate with age. This poses questions for our understanding of "normal" tissues, according to principal investigator of this research.

As researchers continue to develop earlier detection methods using molecular diagnostics along with ductal carcinoma in situ (DCIS) and biopsies, these findings pose a challenge and highlight the potential risk of identifying false positives, as the cells can mistakenly be confused with invasive breast cancer.

A cancer researcher or oncologist seeing the genomic picture of these normal breast tissue cells would classify them as invasive breast cancer.

"We've always been taught that normal cells have 23 pairs of chromosomes, but that appears to be inaccurate because every healthy woman that we analyzed in our study had irregularities, bringing up the very provocative question about when cancer actually occurs", say the researchers.

The study builds upon their previous work on the Human Breast Cell Atlas, which profiled over 714,000 cells to generate a comprehensive genetic map of normal breast tissue at the cellular level.

 Yiyun Lin et al, Normal breast tissues harbour rare populations of aneuploid epithelial cells, Nature (2024). DOI: 10.1038/s41586-024-08129-x

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 10:07am

Females sleep less and awaken more frequently than males, which may have broad implications for medical research

Females sleep less, wake up more often and get less restorative sleep than males, according to a new animal study by researchers.

The findings, published in the journal Scientific Reports, shed new light on what may underlie sleep differences in men and women and could have broad implications for biomedical research, which for decades has focused primarily on males.

In humans, men and women exhibit distinct sleep patterns, often attributed to lifestyle factors and caregiving roles.  However, these new results suggest that biological factors  may play a more substantial role in driving these sleep differences than previously recognized.

Sleep research has exploded in recent years, with thousands of animal studies exploring how insufficient sleep impacts risk of diseases like diabetes, obesity, Alzheimer's and immune disorders—and how such diseases impact sleep.

But many of those results may have been skewed due to a lack of female representation, the study suggests.

The question the female researchers now ask is: Are we creating too much stress for ourselves because we don't sleep as much as our husband or partner and think our sleep is poor when actually that is a normal sleep profile for ourselves?

The authors hope their findings inspire more research into underlying biological differences. More importantly, they hope the study prompts scientists to re-evaluate how they do research and interpret the results.

Grant S. Mannino et al, The importance of including both sexes in preclinical sleep studies and analyses, Scientific Reports (2024). DOI: 10.1038/s41598-024-70996-1

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:51am

Weight-loss drug found to shrink heart muscle in mice and human cells

Trendy weight-loss drugs making headlines for shrinking waistlines may also be shrinking the human heart and other muscles, according to a new  study in JACC: Basic to Translational Science. The authors say the research should serve as a "cautionary tale" about possible long-term health effects of these drugs.

Researchers set out to study why a reported side-effect of the leading weight-loss drug Ozempic is the loss of skeletal muscle.

Ozempic, known medically as semaglutide, was originally designed to help adult patients with type 2 diabetes control their blood sugar. However, this drug—and a host of others in this class of medication—are also being touted for their effectiveness as an anti-obesity medication.

Using mice for the study, the researchers found that heart muscle also decreased in both obese and lean mice. The systemic effect observed in mice was then confirmed in cultured human heart cells.

 Matthew D. Martens et al, Semaglutide Reduces Cardiomyocyte Size and Cardiac Mass in Lean and Obese Mice, JACC: Basic to Translational Science (2024). DOI: 10.1016/j.jacbts.2024.07.006

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:43am

Scientists discover the molecular composition of potentially deadly venomous fish

New research in FEBS Open Bio reveals insights into the venom of two of the most venomous fish species on Earth: the estuarine stonefish (Synanceia horrida) and the reef stonefish (Synanceia verrucosa), which are typically found in the warm and shallow regions of the Indo-Pacific region, the Persian Gulf, and the Red Sea.

Through multiple analytical techniques, investigators discovered the presence of three neurotransmitters new to stonefish venom, namely gamma-aminobutyric acid (GABA), choline, and 0-acetylcholine.

Although these molecules have been previously found in venoms from other species, such as hornets and spiders, this is the first report of a fish venom that contains GABA, which is capable of modulating cardiovascular function with a range of effects including increased heart rate and low blood pressure.

Characterization of the specific composition of each of these fish species' venom not only provides us with a better understanding of envenomation mechanisms, which are needed for the development of targeted treatments against venom effects, but may also aid in the exploration and development of venom-derived compounds in drug discovery.

Silvia Luiza Saggiomo et al, Interrogating stonefish venom: small molecules present in envenomation caused by Synanceia spp., FEBS Open Bio (2024). DOI: 10.1002/2211-5463.13926

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:33am

Ethiopian wolves seen feeding on nectar of red hot poker flowers

Strange things happen in nature!

New findings, published in the journal Ecology, describe a newly documented behavior of Ethiopian wolves (Canis simensis).

Researchers observed Ethiopian wolves foraging for the nectar of the Ethiopian red hot poker (Kniphofia foliosa) flower. Some individuals would visit as many as 30 blooms in a single trip, with multiple wolves from different packs exploiting this resource. There is also some evidence of social learning, with juveniles being brought to the flower fields along with adults.

In doing so, the wolves' muzzles become covered in pollen, which they could potentially transfer from flower to flower as they feed. This novel behavior is perhaps the first known plant-pollinator interaction involving a large predator, as well as the only large meat-eating predator ever to be observed feeding on nectar.

Sandra Lai et al, Canids as pollinators? Nectar foraging by Ethiopian wolves may contribute to the pollination of Kniphofia foliosa, Ecology (2024). DOI: 10.1002/ecy.4470

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:18am

'Flame-Throwing' Guitar Nebula

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:51am

Astronauts found to process some tasks slower in space, but no signs of permanent cognitive decline

A stay in space exerts extreme pressures on the human body. Astronauts' bodies and brains are impacted by radiation, altered gravity, challenging working conditions, and sleep loss—all of which could compromise cognitive functioning. At the same time, they are required to perform complex tasks, and minor mistakes can have devastating consequences.

Working with 25 astronauts who spent an average of six months on the International Space Station (ISS), researchers  have examined changes in a wide range of cognitive performance domains. This dataset makes up the largest sample of cognitive performance data from professional astronauts published to date.

The research shows that there is no evidence of any significant cognitive impairment or neurodegenerative decline in astronauts spending six months on the ISS. Living and working in space was not associated with widespread cognitive impairment that would be suggestive of significant brain damage.

The results showed that responses to tasks assessing processing speed, working memory, and attention were slower than on Earth, but they were no less accurate. These changes, however, did not persist equally long.

Slowed performance on attention, for example, was only observed early during the mission, while slowed performance on processing speed did not return to baseline levels until after the mission ended and the crew were back on Earth.

Overall, astronauts' cognitive performance was stable, and the researchers did not find evidence that would suggest damage to the central nervous system during a six-month space mission.

Cognitive Performance in ISS Astronauts on 6-month Low Earth Orbit Missions, Frontiers in Physiology (2024). DOI: 10.3389/fphys.2024.1451269

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:31am

These networks shared a common feature: Each molecular network had two forms of "memory" storage that captured information learned from the environment. One memory decayed much faster than the other -- a form of memory loss necessary for habituation, the researchers noted. This finding suggests that single cells process and remember information over different time spans.

Studying habituation in single cells could help propel understanding of how learning in general works, the researchers said. The findings also cast the humble single-cell creatures in a new, more tantalizing light: They are not merely molecular machines packed in microscopic bodies, but they are also agents that can learn.

Practical applications of this work:

One daring idea would be to apply the concept of habituation to the relationship between cancer and immunity.

Tumors are notoriously good evaders of immune surveillance because they trick immune cells into viewing them as innocent bystanders. In other words, the immune cells responsible for recognizing cancer may get somehow habituated to the presence of a cancer cell -- the immune cell gets used to the stimulus and no longer responds to it.

If we knew how these false perceptions get encoded in immune cells, we may be able to re-engineer them so that immune cells begin to perceive their environments correctly, the tumor becomes visible as malign, and they get to work.

Lina Eckert, Maria Sol Vidal-Saez, Ziyuan Zhao, Jordi Garcia-Ojalvo, Rosa Martinez-Corral, Jeremy Gunawardena. Biochemically plausible models of habituation for single-cell learning. Current Biology, 2024; DOI: 10.1016/j.cub.2024.10.041

Part 2

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:31am

Research reveals even single-cell organisms exhibit habituation, a simple form of learning

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals. But a new study offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

A dog learns to sit on command, a person hears and eventually tunes out the hum of a washing machine while reading … The capacity to learn and adapt is central to evolution and, indeed, survival.

Habituation involves the lessening response to a stimulus after repeated exposure. Think of the need for a third espresso to maintain the same level of concentration you once achieved with a single shot.

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals.

But a new study, published Nov. 19 in Current Biology, offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

This finding opens up an exciting new mystery for us: How do cells without brains manage something so complex?

The results add to a small but growing body of work on this subject. Earlier work led by Gunawardena found that a single-cell ciliate showed avoidance behavior, not unlike the actions observed in animals that encounter unpleasant stimuli.

Instead of studying cells in a lab dish, the scientists used advanced computer modeling to analyze how molecular networks inside ciliate and mammalian cells respond to different patterns of stimulation. They found four networks that exhibit hallmarks of habituation present in animal brains.

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