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Comment by Dr. Krishna Kumari Challa on October 6, 2022 at 10:40am

For some materials like glass, this involves carefully heating the material so its molecules are unstuck and can arrange themselves in a more organized way. But for some materials, like mayonnaise, heating has destructive or unappetizing side effects. So for materials where heating is not an option, we use a process called mechanical annealing to physically deform the material and bring it to a lower energy state.

Researchers previously investigated how mechanical annealing of disordered solids can allow a material to a form a memory of that deformation, impacting how it responds to future deformation. In a new paper appearing Oct. 5 in the journal Science Advances, the researchers provide a more refined understanding of how memories form in disordered solids and how existing memories can be "read" and even erased.

Nathan C. Keim et al, Mechanical annealing and memories in a disordered solid, Science Advances (2022). DOI: 10.1126/sciadv.abo1614

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Comment by Dr. Krishna Kumari Challa on October 6, 2022 at 10:37am

Some everyday materials have memories, and now they can be erased

Some solid materials have a memory of how they have previously been stretched out, which impacts how they respond to these kinds of deformations in the future. A new study lends insight into memory formation in the foams and emulsions common in food products and pharmaceuticals and provides a new method to erase this memory, which could guide how materials are prepared for future use.

A crease in a piece of paper serves as a memory of being folded or crumpled. A lot of other materials form memories when they are deformed, heated up, or cooled down, and you might not know it unless you ask the right questions. Improving our understanding of how to write, read, and erase memories provides new opportunities for diagnostics and programming of materials. We can find out the history of a material by doing some tests or erase a material's memory and program a new one to prepare it for consumer or industrial use.

The researchers studied memory in a type of material called disordered solids, which have particles that are often erratically arranged. For example, ice cream is a disordered solid made up of a combination of ice crystals, fat droplets, and air pockets mixed together in a random way. This is in stark contrast to materials with "crystalline structures," with particles arranged in highly ordered rows and columns. Disordered solids are common in food sciences, consumer products, and pharmaceuticals and include foams like ice cream and emulsions like mayonnaise.

"Preparation of materials often includes manipulating them in ways that change the arrangement of their molecules, bubbles, or drops, taking them from a higher energy state to a lower energy, more stable state.

part1

Comment by Dr. Krishna Kumari Challa on October 6, 2022 at 8:39am

Nobel prize for three chemists who made molecules 'click'

Three scientists were jointly awarded this year's Nobel Prize in chemistry  this year for developing a way of "snapping molecules together" that can be used to explore cells, map DNA and design drugs that can target diseases such as cancer more precisely.

Americans Carolyn R. Bertozzi and K. Barry Sharpless, and Danish scientist Morten Meldal were cited for their work on click chemistry and bioorthogonal reactions. It's all about snapping molecules together.

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 11:57am

Aftermath of DART Impact

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 11:40am

The aim of the research consortium is to find a chemical compound that activates the receptor in the central nervous system without a sedative effect. In a virtual library of more than 300 million different and easily accessible molecules, the researchers looked for compounds that physically match the receptor but are not chemically related to known medication. After a series of complex virtual docking simulations, around 50 molecules were selected for synthesis and testing and two of these fulfilled the desired criteria. They had good bonding characteristics, activated only certain protein sub-types and thus a very selective set of cellular signal pathways, whereas dexmedetomidine responds to a significantly wider range of proteins.

By further optimizing the identified molecules, for which extremely high-resolution cryo-electron microscopic imaging was used, the researchers were able to synthesize agonists that produced high concentrations in the brain and reduced the sensation of pain effectively in investigations with animal models.

The successful separation of analgesic properties and sedation is a milestone in the development of non-opioid pain medication , especially as the newly-identified agonists are comparatively easy to manufacture and administer orally to patients.

Elissa A. Fink et al, Structure-based discovery of nonopioid analgesics acting through the α 2A -adrenergic receptor, Science (2022). DOI: 10.1126/science.abn7065

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Part 2

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 11:39am

Pain relief without side effects and addiction

New substances that activate adrenalin receptors instead of opioid receptors have a similar pain relieving effect to opiates, but without the negative aspects such as respiratory depression and addiction.

This is the result of research carried out by an international team of researchers. 

Opiates cause addiction, new substances do not

They are a blessing for patients suffering from severe pain, but they also have serious side effects: Opioids, and above all morphine, can cause nausea, dizziness and constipation and can also often cause slowed breathing that can even result in respiratory failure. In addition, opiates are addictive—a high percentage of the drug problem  is caused by pain medication, for example.

In order to tackle the unwanted medical and social effects of opioids, researchers all over the world are searching for alternative analgesics.

They are focusing particularly on the molecular structures of the receptors that dock onto the pharmaceutical substances. It is only when researchers understand these on the atomic level that they can develop effective and safe active substances. They have now turned their attention to a new receptor that is responsible for binding adrenaline—the alpha 2A adrenergic receptor. There are already some analgesics that target this receptor such as brimonidine, clonidine and dexmedetomidine.

Part 1

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 11:30am

Far-ultraviolet LED can kill bacteria and viruses efficiently without harming humans

Ultraviolet germicidal lamps are extremely effective at exterminating bacteria and viruses, and they are routinely used in hospitals to sterilize surfaces and medical instruments.

Such lamps can be made with LEDs, making them energy efficient. But these LEDs use ultraviolet light in a range that damages DNA and thus cannot be used around people. The hunt is on to develop efficient LEDs that shine light within a narrow band of far-ultraviolet light that appears to be both good at disinfecting and safe for people.

A highly efficient LED that is deadly to microbes and viruses but safe for people has been engineered by  physicists. It could one day help countries emerge from the shadows of pandemics by killing pathogens in rooms full of people.

Germicidal LED lamps that operate in the absence of humans are often made from aluminum, gallium and nitrogen. By increasing the amount of aluminum they contain, these LEDs can be modified to work in a wavelength region that is safe for humans. But traditionally this has dramatically reduced their power.

To get around this, Masafumi Jo, Yuri Itokazu and Hideki Hirayama, all at the RIKEN Quantum Optodevice Laboratory, created an LED with a more complex design. They sandwiched together multiple layers, each containing slightly different proportions of aluminum, while in some layers they also added tiny amounts of silicon or magnesium.

This effectively created an obstacle course for electrons, hampering their movement across the material and trapping them for longer in certain areas. This, in turn, increased the amount of light emitted by the device and reduced the amount it absorbed.

To help pin down the best design, the team used  computer simulations to model all possible effects and came up with the best. They will still strive to improve their LED's performance even further, according to their research paper.

 Masafumi Jo et al, Milliwatt-power far-UVC AlGaN LEDs on sapphire substrates, Applied Physics Letters (2022). DOI: 10.1063/5.0088454

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 10:24am

Study finds the mechanism used by metastatic cancer cells to infiltrate the liver

Metastasis—when cancer spreads to form new tumors—causes approximately 90% of cancer-related deaths. Because metastatic cancer cells circulate in the blood, the liver—which filters the blood—is considered the most vulnerable organ, so treatments that prevent liver metastasis are urgently needed. A team of  researchers discovered a mechanism that allows metastatic cancer cells to infiltrate the liver, and how that infiltration can be blocked by inhibiting a related protein.

Approximately 90% of cancer-related deaths are due to metastasis when cancer spreads and forms new tumors. The liver is considered the most vulnerable organ to metastatic cancer: the 5-year survival rate after surgery to remove liver metastases is as low as 30–50%, so developing treatments to prevent liver metastasis is urgently needed.

A group of researchers has identified an alternative pathway for liver metastasis, showing that cancer cells invade via intracellular gap formation in endothelial cells, and clarified the molecular mechanism involved. The results of their research are expected to lead to the development of drugs to prevent and treat metastatic liver cancer.

Truong Huu Hoang et al, Cancer cells produce liver metastasis via gap formation in sinusoidal endothelial cells through proinflammatory paracrine mechanisms, Science Advances (2022). DOI: 10.1126/sciadv.abo5525

Comment by Dr. Krishna Kumari Challa on October 5, 2022 at 10:06am

Nobel prize: physicists share prize for insights into the spooky world of quantum mechanics

The 2022 Nobel prize for physics has been awarded to a trio of scientists for pioneering experiments in quantum mechanics, the theory covering the micro-world of atoms and particles.

Alain Aspect from Université Paris-Saclay in France, John Clauser from J.F. Clauser & Associates in the US, and Anton Zeilinger from University of Vienna in Austria, will share the prize sum of 10 million Swedish kronor (US$915,000) “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science”.

https://www.nobelprize.org/

Comment by Dr. Krishna Kumari Challa on October 4, 2022 at 8:47am

Scientists discover dual-function messenger RNA

For the very first time, a study has discovered an unprecedented pathway producing telomerase RNA from a protein-coding messenger RNA (mRNA).

The central dogma of molecular biology specifies the order in which genetic information is transferred from DNA to make proteins. Messenger RNA molecules carry the genetic information from the DNA in the nucleus of the cell to the cytoplasm where the proteins are made. Messenger RNA acts as the messenger to build proteins.

Actually, there are many RNAs (ribonucleic acids) that are not used to make proteins. 

About 70 percent of the human genome is used to make noncoding RNAs that don't code for protein sequences but have other uses."

Telomerase RNA is one of the noncoding RNAs that assembles along with telomerase proteins to form the enzyme telomerase. Telomerase is crucial for cellular immortality in cancer and stem cells. In this study, scientists show that a fungal telomerase RNA is processed from a protein-coding mRNA, instead of being synthesized independently.

Most RNA molecules are synthesized independently and here scientists uncovered a dual function mRNA that can be used to produce a protein or to make a noncoding telomerase RNA, which is really unique.

 Logeswaran, Dhenugen et al, Biogenesis of telomerase RNA from a protein-coding mRNA precursor, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2204636119. doi.org/10.1073/pnas.2204636119

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