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Comment by Dr. Krishna Kumari Challa on September 20, 2022 at 7:10am

Physicist makes new discovery about telomeres

With the aid of physics and a minuscule magnet, researchers have discovered a new structure of telomeric DNA. Telomeres are sometimes seen as the key to living longer. They protect genes from damage but get a bit shorter each time a cell divides. If they become too short, the cell dies. The new discovery will help us understand aging and disease.
In every cell of our bodies are chromosomes that carry genes that determine our characteristics (what we look like, for instance). At the ends of these chromosomes are telomeres, which protect the chromosomes from damage. They're a bit like aglets, the plastic tips at the end of a shoelace.

The DNA between the telomeres is two meters long, so it has to be folded to fit in a cell. This is achieved by wrapping the DNA is wrapped around packages of proteins; together, the DNA and proteins are called a nucleosome. These are arranged into something similar to a string of beads, with a nucleosome, a piece of free (or unbound) DNA, a nucleosome and so on.

This string of beads then folds up even more. How it does so depends on the length of the DNA between the nucleosomes, the beads on the string. Two structures that occur after folding were already known. In one of them, two adjacent beads stick together and free DNA hangs in between. If the piece of DNA between the beads is shorter, the adjacent beads do not manage to stick together. Then two stacks form alongside each other.

In their study physicists found another telomere structure. Here the nucleosomes are much closer together, so there is no longer any free DNA between the beads. This ultimately creates one big helix, or spiral, of DNA.

The new structure was discovered with a combination of electron microscopy and molecular force spectroscopy.  Here one end of the DNA is attached to a glass slide and a tiny magnetic ball is stuck to the other. A set of strong magnets above this ball then pull the string of pearls apart. By measuring the amount of force needed to pull the beads apart one by one, you find out more about how the string is folded. The researchers  then used an electron microscope to get a better picture of the structure.

 If we know the structure of the molecules, this will give us more insight into how genes are switched on and off and how enzymes in cells deal with telomeres: how they repair and copy DNA, for example. The discovery of the new telomeric structure will improve our understanding of the building blocks in the body. And that in turn will ultimately help us study aging and diseases such as cancer and develop drugs to fight them.

Aghil Soman et al, Columnar structure of human telomeric chromatin, Nature (2022). DOI: 10.1038/s41586-022-05236-5

Comment by Dr. Krishna Kumari Challa on September 20, 2022 at 6:59am

Warmer Earth could see smaller butterflies that struggle to fly, affecting food systems

Comment by Dr. Krishna Kumari Challa on September 17, 2022 at 12:22pm

Constipated scorpions, love at first sight inspire Ig Nobels

The sex lives of constipated scorpions, cute ducklings with an innate sense of physics, and a life-size rubber moose may not appear to have much in common, but they all inspired the winners of this year's Ig Nobels, the prize for comical scientific achievement.

The winners, honored in 10 categories, also included scientists who found that when people on a blind date are attracted to each other, their heart rates synchronize, and researchers who looked at why legal documents can be so utterly baffling, even to lawyers themselves.

You feel science is fun if you read things like these: 

Scorpions can detach a body part to escape a predator—a process called autotomy. But when they lose their tails, they also lose the last portion of the digestive tract, which leads to constipation—and, eventually, death, scientists wrote in the journal "Integrated Zoology."

The long-term decrease in the locomotor performance of autotomized males may impair mate searching.

https://arstechnica.com/science/2022/09/maya-ritual-enemas-and-cons...

Comment by Dr. Krishna Kumari Challa on September 16, 2022 at 11:52am

Researchers develop painless tattoos that can be self-administered

 Instead of sitting in a tattoo chair for hours enduring painful punctures, imagine getting tattooed by a skin patch containing microscopic needles. Researchers have developed low-cost, painless, and bloodless tattoos that can be self-administered and have many applications, from medical alerts to tracking neutered animals to cosmetics.

Researchers have miniaturized the needle so that it's painless, but still effectively deposits tattoo ink in the skin.

Tattoos are used in medicine to cover up scars, guide repeated cancer radiation treatments, or restore nipples after breast surgery. Tattoos also can be used instead of bracelets as medical alerts to communicate serious medical conditions such as diabetes, epilepsy, or allergies.

Various cosmetic products using microneedles are already on the market—mostly for anti-aging—but developing microneedle technology for tattoos is new. 

Tattoos typically use large needles to puncture repeatedly into the skin to get a good image, a time-consuming and painful process. The  Tech team has developed microneedles that are smaller than a grain of sand and are made of tattoo ink encased in a dissolvable matrix.
Because the microneedles are made of tattoo ink, they deposit the ink in the skin very efficiently.

Although most microneedle patches for pharmaceuticals or cosmetics have dozens or hundreds of microneedles arranged in a square or circle, microneedle patch tattoos imprint a design that can include letters, numbers, symbols, and images. By arranging the microneedles in a specific pattern, each microneedle acts like a pixel to create a tattoo image in any shape or pattern.

The researchers start with a mold containing microneedles in a pattern that forms an image. They fill the microneedles in the mold with tattoo ink and add a patch backing for convenient handling. The resulting patch is then applied to the skin for a few minutes, during which time the microneedles dissolve and release the tattoo ink. Tattoo inks of various colors can be incorporated into the microneedles, including black-light ink that can only be seen when illuminated with ultraviolet light.

Song Li, Youngeun Kim, Jeong Woo Lee, Mark R. Prausnitz. Microneedle patch tattoos. iScience, 2022; 105014 DOI: 10.1016/j.isci.2022.105014

Comment by Dr. Krishna Kumari Challa on September 16, 2022 at 11:38am

New lactic acid bacteria create natural sweetness in yogurt

Researchers have developed a yogurt bacterium, which can cleave lactose in a cost-effective and sustainable manner. This makes it possible to create natural sweetness in yogurt with less added sugar.

Yogurt without added sugar is a relatively sour experience. Often fruit or berries are added to improve taste, and sugar or sweeteners are added to increase sweetness. However, consumers are increasingly demanding natural foods with less added sugar.

To meet this demand researchers have developed a new and natural way to cleave the milk sugar, which relies on safe lactic acid bacteria. The developed lactic acid bacteria create natural sweetness in the yogurt, thus reducing the need for added sugar.

Belay Tilahun Tadesse et al, Consolidated Bioprocessing in a Dairy Setting─Concurrent Yoghurt Fermentation and Lactose Hydrolysis without Using Lactase Enzymes, Journal of Agricultural and Food Chemistry (2022). DOI: 10.1021/acs.jafc.2c04191

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Yogurt is fermented milk, and milk naturally contains around 50 grams sugar (lactose) per liter. Milk sugar is characterized by its low sweetness, but by breaking down lactose with enzymes, more sweet sugars (glucose and galactose) are released. By breaking down 70% of the lactose in milk, the sweetness can be increased what corresponds to 20 grams per liter of regular sugar.

Commercially available lactase enzymes currently used for breaking down lactose in milk products, are made using microorganisms, which involves, a tedious and costly purification process. Furthermore, transportation from the manufacturer site to the dairy adds to the costs.

With the solution that the DTU researchers have developed, the lactic acid bacteria-based lactase can be grown and used directly at the dairy, and in the milk that ends up being yogurt. In this way the costs for purchasing the lactase and transportation are reduced,

Comment by Dr. Krishna Kumari Challa on September 16, 2022 at 10:57am

Conversion to LED lighting brings new kind of light pollution

A team of researchers  has found that the slow conversion of outdoor lighting to LEDs across much of Europe has led to the development of a new kind of light pollution. In their paper published in the journal Science Advances, the group describes their study of photographs taken from the International Space Station.

Prior research has shown that artificial light in natural environments adversely impacts wildlife and humans. Studies have shown that both animals and humans can experience disruptions to sleep patterns, for example. And many animals can become confused by the light at night, leading to survival problems. In this new effort, the researchers noted that officials in many countries have been promoting the use of LED lighting over traditional sodium lighting along roads and in parking areas due to the reduced energy demands of LEDs. To learn more about the impact of this change, the researchers obtained photographs taken by astronauts aboard the ISS over the years 2012 to 2013 and from 2014 to 2020. The photographs provide a much better range of light wavelengths than satellite images. The researchers were able to see which parts of Europe have converted to LED lighting and to what degree. They found that the U.K., Italy and Ireland, for example, have experienced significant changes, while other countries such as Austria, Germany and Belgium have experienced little change. They found that the LEDs emitted light at different wavelengths than the sodium bulbs. Noticeably different was the increase in blue light emissions in those areas that have converted to LED lighting. Blue lighting, the researchers note, has been found to interfere with the production of melatonin in humans and other animals, which interferes with sleep patterns. The researchers suggest the increase of blue light in areas lit by LEDs could be having a negative impact on the environment and also the people who live and work in such places. They suggest officials take a closer look at the impact of LED lighting before pushing ahead with new projects.

Alejandro Sánchez de Miguel et al, Environmental risks from artificial nighttime lighting widespread and increasing across Europe, Science Advances (2022). DOI: 10.1126/sciadv.abl6891

Comment by Dr. Krishna Kumari Challa on September 15, 2022 at 12:19pm

Drug turns cancer gene into 'eat me' flag for immune system

Tumor cells are notoriously good at evading the human immune system; they put up physical walls, wear disguises and handcuff the immune system with molecular tricks. Now,  researchers have developed a drug that overcomes some of these barriers, marking cancer cells for destruction by the immune system. The new therapy, described in Cancer Cell, pulls a mutated version of the protein KRAS to the surface of cancer cells, where the drug-KRAS complex acts as an "eat me" flag. Then, an immunotherapy can coax the immune system to effectively eliminate all cells bearing this flag.

Ziyang Zhang, Peter J. Rohweder, Chayanid Ongpipattanakul, Koli Basu, Markus-Frederik Bohn, Eli J. Dugan, Veronica Steri, Byron Hann, Kevan M. Shokat, Charles S. Craik. A covalent inhibitor of K-Ras(G12C) induces MHC class I presentation of haptenated peptide neoepitopes targetable by immunotherapy. Cancer Cell, 2022; 40 (9): 1060 DOI: 10.1016/j.ccell.2022.07.005

Comment by Dr. Krishna Kumari Challa on September 15, 2022 at 12:14pm

How this jellyfish can live forever

The tiny translucent jellyfish Turritopsis dohrnii can revert to an immature polyp state and revive itself again and again — effectively making it immortal. Researchers have now sequenced the jellyfish’s genome and studied the genes involved in its rejuvenation. They found that genes associated with DNA storage were highly expressed in adult jellyfish, but reduced as the animals transformed into polyps. However, genes linked to pluripotency, or the ability of cells to turn into any cell type, were increasingly expressed as the jellyfish reverted.

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Crossref citations come out into the open

The reference lists in Crossref are now free to read and reuse. The Crossref database registers DOIs, or digital object identifiers, for many of the world’s academic publications. Open-science advocates have for years campaigned to make papers’ citation data accessible under liberal copyright licen... to identify research trends and areas of research that need funding, and to spot when scientists are manipulating citation counts.

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Some microbes lie in wait until their hosts unknowingly give them t...

After more than two years of the COVID-19 pandemic, you might picture a virus as a nasty spiked ball—a mindless killer that gets into a cell and hijacks its machinery to create a gazillion copies of itself before bursting out. For many viruses, including the coronavirus that causes COVID-19, the "mindless killer" epithet is essentially true.

Comment by Dr. Krishna Kumari Challa on September 15, 2022 at 11:31am

Electric vehicles are now powering homes when utilities go down

Soon you'll be able to say goodbye to gas-powered generators and storage batteries if you want to power your home during a utility outage.

Your backup power source will be sitting in your driveway or garage, ready to keep your lights on, your fridge cold and your air conditioner blowing. Best of all, your power source will run silently, emit no dangerous exhaust, and be capable of safely running inside or outside during hurricanes and for at least a couple days afterward while your utility works to restore power. Electric vehicles with bidirectional charging capabilities are starting to hit the market as the auto industry transitions away from internal combustion engines. Just a handful of vehicles with so-called Vehicle-to-Home (V2H) capabilities are available now—and require costly aftermarket gear—but industry analysts expect their numbers to increase as more EVs come to market.

Bidirectional charging, as the term implies, is the capability to both receive and send power, and its availability in electric vehicles could provide a valuable layer of security to homeowners as severe weather events become more frequent and destructive.

https://techxplore.com/news/2022-09-storage-batteries-gas-electric-...

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Comment by Dr. Krishna Kumari Challa on September 15, 2022 at 9:47am

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