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Comment by Dr. Krishna Kumari Challa on November 23, 2022 at 9:34am

Scientists unlock nature's secret to super-selective binding

 Researchers have discovered that it is not just molecular density, but also pattern and structural rigidity, that control super-selective binding interactions between nanomaterials and protein surfaces. The breakthrough could help optimize existing approaches to virus prevention and cancer detection.

So much of biology comes down to the biophysical process of binding: making a strong connection between one or more groups of atoms—known as ligands—to their corresponding receptor molecule on a surface. A binding event is the first fundamental process that allows a virus to infect a host, or chemotherapy to fight cancer. But binding interactions—at least, our understanding of them—have a "Goldilocks problem": too few ligands on one molecule makes it impossible for it to stably bind with the correct target, while too many can result in undesirable side-effects.

When binding is triggered by a threshold density of target receptors, scientists call this 'super-selective' binding, which is key to preventing random interactions that could dysregulate biological function. 

Since nature typically doesn't overcomplicate things, researchers wanted to know the minimum number of binding interactions that would still allow for super-selective binding to occur. They were also interested to know whether the pattern the ligand molecules are arranged in makes a difference in selectivity. As it turns out, it does.

They have recently published a study in the Journal of the American Chemical Society that identifies the optimal ligand number for super-selective binding: six. But they also found, to their excitement, that the arrangement of these ligands—in a line, circle, or triangle, for example—also significantly impacted binding efficacy. They have dubbed the phenomenon "multivalent pattern recognition" or MPR.

After engineering a series of ligand-receptor architectures to explore how density, geometry, and nano-spacing influenced binding super-selectivity, the team realized that rigidity was a key factor. The more flexible, the less precise.

Diagnostics and therapeutics such as chemotherapy could also benefit from super-selectivity, which could allow for more reliable binding with cancer cells, for which certain receptor molecules are known to have a higher density. In this case, healthy cells would remain undetected, drastically reducing side effects.

Finally, such selectivity engineering could offer key insights into complex interactions within the immune system.

Hale Bila et al, Multivalent Pattern Recognition through Control of Nano-Spacing in Low-Valency Super-Selective Materials, Journal of the American Chemical Society (2022). DOI: 10.1021/jacs.2c08529

Comment by Dr. Krishna Kumari Challa on November 23, 2022 at 8:41am

Things that make  people feel more awake and alert during mornings and afternoons

A team of researchers affiliated with multiple institutions has isolated factors that they think have an impact on how awake and/or alert people feel during the day.

Prior research has shown that more people than ever are complaining of feeling tired, sleepy and unalert during the daytime. Such complaints have been connected to increases in motor vehicle and work accidents and also sloppy job performance. In this new effort, the researchers noted that little research has been conducted looking into the factors that contribute to daytime alertness. To rectify that problem, they conducted a study of their own.

The researchers recruited 833 volunteers (many of whom were either identical or fraternal twins) to undergo testing for two weeks. Each adhered to a prescribed diet and wore a watch that recorded their sleep and physical activity and also their glucose levels. They also recorded the food they ate using a custom phone app, which they also used to record their level of alertness. After the two-week period, the researchers found some patterns. For example, those people who slept longer reported feeling more alert the next day—no surprise there.

But they also found that it was not duration that led to an increase in alertness, but the time that they woke up—waking up later than normal, they found, made the volunteers feel more alert, at least during the morning, even if they did not go to bed late. They also found that the volunteers were more alert on days when they were physically active the day before. And they found that eating a high-carb breakfast, such as muffins, resulted in higher morning alertness.

Drinking pure glucose had them feeling even more alert. A high-protein breakfast, on the other hand, had the volunteers dragging in the morning. The researchers also found four factors that most contributed to daily variances for the volunteers: age, sleep, mood and frequency of eating—eating less often seemed to reduce next-day fatigue.

Raphael Vallat et al, How people wake up is associated with previous night's sleep together with physical activity and food intake, Nature Communications (2022). DOI: 10.1038/s41467-022-34503-2

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Comment by Dr. Krishna Kumari Challa on November 22, 2022 at 11:10am

A combination of ultrasound and nanobubbles allows cancerous tumors...

A new technology developed at Tel Aviv University makes it possible to destroy cancerous tumors in a targeted manner, via a combination of ultrasound and the injection of nanobubbles into the bloodstream. According to the research team, unlike invasive treatment methods or the injection of microbubbles into the tumor itself, this latest technology enables the destruction of the tumor in a non-invasive manner.

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Researchers develop a new type of light-sensitive nanoparticle to h...

Oregon State University scientists have produced a proof of concept for a new and better way of caring for women facing the life-threatening situation of ectopic pregnancy, which occurs when a fertilized egg implants somewhere other than the lining of the uterus.

Comment by Dr. Krishna Kumari Challa on November 22, 2022 at 11:08am

Discovery reveals 'brain-like computing' at molecular level is possible

A discovery has revealed for the first time that unconventional brain-like computing at the tiniest scale of atoms and molecules is possible.

Researchers which consisted an international team of scientists  created a new type of organic material that learns from its past behaviour. The discovery of the "dynamic molecular switch" that emulates synaptic behavior is revealed in a new study in the journal Nature Materials.

The team developed a two-nanometer thick layer of molecules, which is 50,000 times thinner than a strand of hair and remembers its history as electrons pass through it. Switching probability and the values of the on/off states continually change in the molecular material, which provides a disruptive new alternative to conventional silicon-based digital switches that can only ever be either on or off.

The newly discovered dynamic organic switch displays all the mathematical logic functions necessary for deep learning, successfully emulating Pavlovian "call and response" synaptic brain-like behavior.

The researchers demonstrated the new materials properties using extensive experimental characterization and electrical measurements supported by multi-scale modeling spanning from predictive modeling of the molecular structures at the quantum level to analytical mathematical modeling of the electrical data.

Enrique del Barco, Dynamic molecular switches with hysteretic negative differential conductance emulating synaptic behaviour, Nature Materials (2022). DOI: 10.1038/s41563-022-01402-2

https://phys.org/news/2022-11-discovery-reveals-brain-like-molecula...

Comment by Dr. Krishna Kumari Challa on November 22, 2022 at 10:41am

Lab mice fed processed food found to fare worse against flu than those eating grains

A team of researchers  has found that lab mice are more likely to survive a flu infection if they are fed grain-based foods rather than processed food. The paper is published in Cell Reports.

In recent years, medical researchers have reported evidence that diet plays a larger role in illness recovery than was thought. Some studies have shown, for example, that caloric density and the concentration of nutrients consumed while recovering from an infection can have a major impact on the severity of the infection. In this new effort, the researchers found evidence suggesting that other characteristics of food can also play a role in illness recovery, at least in mice.

In this new effort, the researchers were studying how mammals such as mice fight off influenza infections. As part of that effort, they inadvertently fed two groups of lab mice slightly different meals that were thought to be equivalent in nutritional value and hence unlikely to have an impact on disease recovery. More specifically, they fed one group of mice a diet consisting mostly of grains. The other mice were fed a highly processed diet.

Both groups were subsequently infected with the influenza virus and were kept on the same diets they had prior to being infected. The researchers note that prior studies had shown that mice fed either diet when not battling an infection displayed little difference in health or behavior. But when infected with influenza, the researchers found that all of those fed the highly processed diet died. They also found that those fed the highly processed diet failed to regain weight lost due to the illness. In sharp contrast, all of the mice on the grain-based diet began regaining weight within 10 days of initial infection, and all of them recovered.

The researchers note that the difference in survival was not due to differences in an immune response, but was instead due to recovery issues. They note that the mice on the highly processed food diet ate less than those given grains and wound up getting less nutrients. They also had cooler body cores. The researchers also found some evidence that suggested IFN-γ, a signaling protein, played a role in the outcomes for the mice.

Taylor A. Cootes et al, The quality of energy- and macronutrient-balanced diets regulates host susceptibility to influenza in mice, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.111638

Comment by Dr. Krishna Kumari Challa on November 21, 2022 at 9:46am

Why Scientists Are Listening to Coral Reefs

Comment by Dr. Krishna Kumari Challa on November 21, 2022 at 9:13am

Some Sugar Free Gummy Bears Are In Reality Laxatives! 

Comment by Dr. Krishna Kumari Challa on November 19, 2022 at 11:13am

Making mosquitoes' love songs fall on deaf ears

A team of researchers  have developed a new method that may help control mosquito populations. The annoying buzzing sound that mosquitoes make when flying inspired this technique.

Mosquitoes are not just a nuisance to people sitting outside on warm summer evenings. They also spread deadly diseases that kill thousands of people every year, including dengue, malaria, and the Zika virus. Therefore, it is vital to reduce mosquito populations around the world. Unfortunately, commonly used insecticides have become less effective over time because mosquitoes have developed resistance. They also have a negative impact on the environment. Therefore, alternative methods are needed for mosquito control.

One promising method for controlling mosquitoes takes advantage of perhaps their most annoying feature—their high-pitched buzzing. Females create this sound as they fly around seeking sources of blood. Male mosquitoes listen specifically for this characteristic high-pitched noise. Shaped like antennas, male mosquito ears vibrate at the same frequency as the female mosquito's wings. When a female flies by, the male's ears detect this frequency and resonate, sending a signal to their brain that helps them identify a potential mate.

A team of researchers  tested whether they could control mosquito mating behavior by altering the frequency at which male mosquitoes listen. By making the male mosquitoes' ears go "out of tune," they sought to influence their mating behavior.

he team first identified the involvement of the major neurotransmitter serotonin in the auditory system of the insect. Serotonin plays an important role in nervous systems and brains of various animals', influencing a wide range of behaviors.

After demonstrating serotonin in the mosquito auditory system, the team's next step was to manipulate serotonin levels. To do this, they used a method called "laser doppler vibrometry." This involves using a laser as a highly sensitive measurement tool to detect changes in the nanoscale vibrations of mosquito ears after exposure to serotonin-related compounds.

The researchers discovered that after feeding mosquitoes a serotonin-inhibiting compound, the male ears' vibration frequency decreased. When they gave the mosquitoes glucose laced with a compound that inhibited serotonin, both the range of frequencies the mosquitoes responded to, and their response itself, were reduced.

The next step in the development of a potential auditory-based "birth control" will involve identifying the exact receptors responsible for tuning the ears of mosquitoes. This could enable researchers to administer targeted compounds to disrupt mating behavior. 

Yifeng Y. J. Xu, YuMin M. Loh, Tai-Ting Lee, Takuro S. Ohashi, Matthew P. Su, Azusa Kamikouchi. Serotonin modulation in the male Aedes aegypti ear influences hearing. Frontiers in Physiology, 2022; 13 DOI: 10.3389/fphys.2022.931567

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Comment by Dr. Krishna Kumari Challa on November 19, 2022 at 10:59am

Messel boa: Live birth in a 47-million-year-old snake

team of scientists, including Senckenberg’s Krister Smith, has discovered the world’s first fossil evidence of live birth in snakes. The fossil they examined came from the Hessian UNESCO World Heritage Site “Messel Pit.” In the study, published in the journal “The Science of Nature,” the researchers describe bones of snake embryos discovered in the mother’s body. The finding shows that viviparous snakes already existed at least 47 million years ago.

Most reptiles alive today lay eggs; this so-called oviparity is their most common mode of reproduction. But there are exceptions: Numerous species of lizards and snakes are known to deviate from the norm and give birth to their offspring alive – viviparously. Fossil preservation of reproductive events is generally very rare. In total, only two fossil records of viviparous land reptiles have been discovered to date. Scientists have now succeeded in describing the world’s first fossil evidence of a viviparous snake.

The fossil Messelophis variatus, from a family of boa-like snakes, is about 50 centimeters long, dates from the Eocene, and is related to modern-day dwarf boas from Central America. The species is among the most common snakes known from Messel. Nevertheless, this specimen,  is about 47 million years old.

It is a pregnant female with at least two embryos found in the posterior third of her trunk area. These bones were located quite a distance behind the stomach – if they were part of the snake’s prey, they would have already been digested this far back in the intestine and would no longer be recognizable. Thus, they must represent the boa’s embryos. The fact that the bones are from very young snakes, yet already further developed than in an unlaid egg, supports the assumption that scientists are dealing with a pregnant, viviparous female.

In live births, the young remain in the female’s body until they are viable – eliminating the need for a protective eggshell. This is considered an advantageous evolutionary strategy for reptiles in cold climates, as the temperature inside the female’s body is more stable and thus safer for their offspring. Therefore, many of today’s viviparous lizards and snakes have evolved in rather cooler climates. “During the Eocene, however, the Earth was dominated by a persistent greenhouse climate with warm temperatures, a high carbon dioxide content in the atmosphere, and ice-free poles. Around the Messel Lake, average temperatures at that time were about 20 degrees Celsius, and winter temperatures did not fall below freezing. Why the boas gave birth to live offspring 47 million years ago in spite of this fact is still unknown. Perhaps additional fossils from this unique site will help us solve this mystery!

Mariana Chuliver et al, Live birth in a 47-million-year-old snake, The Science of Nature (2022). DOI: 10.1007/s00114-022-01828-3

Comment by Dr. Krishna Kumari Challa on November 19, 2022 at 9:50am

Down syndrome, like Alzheimer's, is a double-prion disorder

The brains of people with Down syndrome develop the same neurodegenerative tangles and plaques associated with Alzheimer's disease and frequently demonstrate signs of the neurodegenerative disorder in their forties or fifties. A new study from researchers shows that these tangles and plaques are driven by the same amyloid beta (Aß) and tau prions that they showed are behind Alzheimer's disease in 2019.

Prions begin as normal proteins that become misshapen and self-propagate. They spread through tissue like an infection by forcing normal proteins to adopt the same misfolded shape. In both Alzheimer's and Down syndrome, as Aß and tau prions accumulate in the brain, they cause neurological dysfunction that often manifests as dementia.

Tau tangles and Aß plaques are evident in most people with Down syndrome by age 40, according to the National Institute on Aging, with at least 50% of this population developing Alzheimer's as they age.

The new study, published Nov. 7, 2022, in Proceedings of the National Academy of Sciences, highlights how a better understanding of Down syndrome can lead to new insights about Alzheimer's, as well.

Carlo Condello et al, Aβ and tau prions feature in the neuropathogenesis of Down syndrome, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2212954119

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