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Comment by Dr. Krishna Kumari Challa on February 3, 2021 at 11:19am

Twisted van der Waals materials as a new platform to realize exotic...

Researchers from the MPSD, the RWTH Aachen University and the Flatiron Institute, Columbia University (both in the U.S.) and part of the Max Planck—New York City Center for Non-equilibrium Quantum Phenomena have provided a fresh perspective on the potential of twisted van der Waals materials for realizing novel and elusive states of matter and providing a unique materials-based quantum simulation platform.

Comment by Dr. Krishna Kumari Challa on February 3, 2021 at 8:54am

Say goodbye to the dots and dashes to enhance optical storage media

Innovators have created technology aimed at replacing Morse code with colored "digital characters" to modernize optical storage. They are confident the advancement will help with the explosion of remote data storage during and after the COVID-19 pandemic.

Morse code has been around since the 1830s. The familiar dots and dashes system may seem antiquated given the amount of information needed to be acquired, digitally archived and rapidly accessed every day. But those same basic dots and dashes are still used in many optical media to aid in storage.

A new technology developed at Purdue is aimed at modernizing the optical digital storage technology. Rather than using the traditional dots and dashes as commonly used in these technologies, the  innovators encode information in the angular position of tiny antennas, allowing them to store more data per unit area.

The storage capacity greatly increases because it is only defined by the resolution of the sensor by which you can determine the angular positions of antennas. They mapped the antenna angles into colors, and the colors are decoded.

This advancement allows for more data to be stored and for that data to be read at a quicker rate. The research is published in Laser & Photonics Reviews.

 Maowen Song et al, Enabling Optical Steganography, Data Storage, and Encryption with Plasmonic Colors, Laser & Photonics Reviews (2021). DOI: 10.1002/lpor.202000343

https://phys.org/news/2021-02-goodbye-dots-dashes-optical-storage.h...

Comment by Dr. Krishna Kumari Challa on February 3, 2021 at 8:41am

A new way to make wood transparent, stronger and lighter than glass

A team of researchers at the University of Maryland, has found a new way to make wood transparent. In their paper published in the journal Science Advances, the group describes their process and why they believe it is better than the old process.

Qinqin Xia et al. Solar-assisted fabrication of large-scale, patternable transparent wood, Science Advances (2021). DOI: 10.1126/sciadv.abd7342

https://phys.org/news/2021-02-wood-transparent-stronger-lighter-gla...

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Comment by Dr. Krishna Kumari Challa on February 3, 2021 at 8:38am

An origami-inspired medical patch for sealing internal injuries

Many surgeries today are performed via minimally invasive procedures, in which a small incision is made and miniature cameras and surgical tools are threaded through the body to remove tumors and repair damaged tissues and organs. The process results in less pain and shorter recovery times compared to open surgery.

While many procedures can be performed in this way, surgeons can face challenges at an important step in the process: the sealing of internal wounds and tears.

The bioadhesives currently used in minimally invasive surgeries are available mostly as biodegradable liquids and glues that can be spread over damaged tissues. When these glues solidify, however, they can stiffen over the softer underlying surface, creating an imperfect seal. Blood and other biological fluids can also contaminate glues, preventing successful adhesion to the injured site. Glues can also wash away before an injury has fully healed, and, after application, they can also cause inflammation and scar tissue formation.

Taking inspiration from origami, MIT engineers have now designed a medical patch that can be folded around minimally invasive surgical tools and delivered through airways, intestines, and other narrow spaces, to patch up internal injuries. The patch resembles a foldable, paper-like film when dry. Once it makes contact with wet tissues or organs, it transforms into a stretchy gel, similar to a contact lens, and can stick to an injured site.

Given the limitations of current designs, the team aimed to engineer an alternative that would meet three functional requirements. It should be able to stick to the wet surface of an injured site, avoid binding to anything before reaching its destination, and once applied to an injured site resist bacterial contamination and excessive inflammation.

The team's design meets all three requirements, in the form of a three-layered patch. The middle layer is the main bioadhesive, made from a hydrogel material that is embedded with compounds called NHS esters. When in contact with a wet surface, the adhesive absorbs any surrounding water and becomes pliable and stretchy, molding to a tissue's contours. Simultaneously, the esters in the adhesive form strong covalent bonds with compounds on the tissue surface, creating a tight seal between the two materials. 

This could be used to repair a perforation from a coloscopy, or seal solid organs or blood vessels after a trauma or elective surgical intervention. Instead of having to carry out a full open surgical approach, one could go from the inside to deliver a patch to seal a wound at least temporarily and maybe even long-term.

In contrast to existing surgical adhesives, the team's new tape is designed to resist contamination when exposed to bacteria and bodily fluids. Over time, the patch can safely biodegrade away. The team has published its results in the journal Advanced Materials.

Sarah J. Wu et al. A Multifunctional Origami Patch for Minimally Invasive Tissue Sealing, Advanced Materials (2021). DOI: 10.1002/adma.202007667

https://phys.org/news/2021-02-origami-inspired-medical-patch-intern...

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 11:59am

A new treatment to help people with a spinal cord injury

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 11:59am

A call for a global ban on lead paint

Once lead paint is on a wall, it becomes an expensive problem to fix. In impoverished settings, be they neighborhoods in Philadelphia or developing nations globally, remediation can be prohibitively costly.

Branches and treetops can reduce greenhouse gas emission from heavy...

New research from University of Gävle shows that forest residues can generate large amounts of biofuel, and, in the long run, reduce greenhouse gas emission by 88-94% from heavy transport on Swedish roads.

Water disinfection with ozone

While chlorine and ultraviolet light are the standard means of disinfecting water, ozone is equally effective in killing germs. To date, ozone has only been used as an oxidation agent for treating water in large plants. Now, however, a project consortium from Schleswig-Holstein is developing a miniaturized ozone generator for use in smaller applications such as water dispensers or small domestic appliances. The Fraunhofer Institute for Silicon Technology ISIT has provided the sensor chip and electrode substrates for the electrolysis cell.

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:40am

Virtual conference CO2 emissions quantified in new study

The virtual conferencing that has replaced large, in-person gatherings in the age of COVID-19 represents a drastic reduction in carbon emissions, but those online meetings still come with their own environmental costs, new research from the University of Michigan shows.

The research offers a framework for analyzing and tallying the carbon emissions of an online conference based on factors that include everything from energy used by servers and monitors to the resources used to manufacture and distribute the computers involved.

Individuals could skip features like gallery view, disable HD video and repair instead of replace computers to extend their useful lifetimes.

Grant Faber. A framework to estimate emissions from virtual conferences, International Journal of Environmental Studies (2021). DOI: 10.1080/00207233.2020.1864190

https://phys.org/news/2021-02-virtual-conference-co2-emissions-quan...

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:34am

Lactobacillus manipulates bile acids to create favorable gut environment

New research  reveals that probiotic Lactobacillus bacteria use enzymes situationally to manipulate bile acids and promote their own survival in the gut. These findings further elucidate the complicated relationship between bile acids and gut bacteria and could eventually enable researchers to design lactobacilli with therapeutic properties, thereby engineering a healthier human gut environment.

Bile acids are key players in digestion and overall gut health. Produced in the liver and released after we eat, these acids not only break down cholesterol and help regulate fat absorption, they also have a huge impact on what types of bacteria colonize the gut.

As bile acids move through the gut, they are initially chemically modified through the addition of an amino acid (frequently glycine or taurine), creating a complex "conjugated" bile acid pool. Some gut bacteria have enzymes, called bile salt hydrolases (BSHs), which can cleave or "deconjugate" these amino acids from the bile acids, allowing other bacteria to further transform the bile acids as they continue through the colon. These transformations affect the bile acids' toxicity, which in turn affects the ability of different bacteria to survive in the gut.

The assumed relationship was that probiotic bacteria like Lactobacillus have BSHs that just deconjugate the bile acid, rendering it less toxic and allowing the bacteria to survive.

The interplay between bile and bacteria has a huge impact on their ability to live, thrive or die in a very competitive environment.

 Matthew H. Foley el al., "Lactobacillus bile salt hydrolase substrate specificity governs bacterial fitness and host colonization," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2017709118

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It was found that bile acid toxicity was not merely dependent upon whether the bile acid was conjugated or deconjugated by a BSH; rather, the relationships were dependent upon the type of bile acid, the bacteria being acted upon, and which BSH was present.

https://phys.org/news/2021-02-lactobacillus-bile-acids-favorable-gu...

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:29am

Marine organisms use previously undiscovered receptors to detect, respond to light

Just as plants and animals on land are keenly attuned to the hours of sunlight in the day, life in the oceans follows the rhythms of the day, the seasons and even the moon. A new study finds the biological light switches that make this possible.

Single-celled organisms in the open ocean use a diverse array of genetic tools to detect light, even in tiny amounts, and respond.

If you look in the ocean environment, all these different organisms have this day-night cycle. They are very in tune with each other, even as they get moved around. How do they know when it's day? How do they know when it's night?

By analyzing RNA filtered out of seawater samples collected throughout the day and night, the study identifies four main groups of photoreceptors, many of them new. This genetic activity uses light to trigger changes in the metabolism, growth, cell division, movements and death of marine organisms.

The discovery of these new genetic "light switches" could also aid in the field of optogenetics, in which a cell's function can be controlled with light exposure. Today's optogenetic tools are engineered by humans, but versions from nature might be more sensitive or better detect light of particular wavelengths, the researchers think.

Sacha N. Coesel el al., "Diel transcriptional oscillations of light-sensitive regulatory elements in open-ocean eukaryotic plankton communities," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2011038118

https://phys.org/news/2021-02-marine-previously-undiscovered-recept...

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:24am

Part 2

investigated whether sidewinders' skin might also play a role in their unique movement style.

They focused on three species of sidewinders, all of them vipers, in residence at zoos: The sidewinder rattlesnake (Crotalus cerastes), found in the deserts of the Southwestern United States and northern Mexico; and the Saharan horned viper (Cerastes cerastes) and the Saharan sand viper (Cerastes vipera), both from the deserts of north Africa.

Skins shed from the sidewinders were collected and scanned with atomic force microscopy, a technique that provides resolution at the atomic level, on the order of fractions of a nanometer. For comparison, they also scanned snake skins shed from non-sidewinders.

As expected, the microscopy revealed tiny, head-to-tail pointing spikes on the skin of the non-sidewinders. Previous research had identified these micro spikes on a variety of other slithering snakes.

The current study, however, found that the skin of sidewinders is different. The two African sidewinders had micro pits on their bellies and no spikes. The skin of the sidewinder rattlesnake was also studded with tiny pits, along with a few, much smaller, spikes—although far fewer spikes than those of the slithering snakes.

The researchers created a mathematical model to test how these different structures affect frictional interactions with a surface. The model showed that head-to-tail pointing spikes enhance the speed and distance of forward undulation but are detrimental to sidewinding.

The model also showed that the uniform, non-directional structure of the round pits enhanced sidewinding, but was not as efficient as spikes for forward undulation.

The research provides snapshots at different points in time of convergent evolution—when different species independently evolve similar traits as a result of having to adapt to similar environments.

Jennifer M. Rieser el al., "Functional consequences of convergently evolved microscopic skin features on snake locomotion," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2018264118

https://phys.org/news/2021-02-physics-snakeskin-sidewinding.html?ut...

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