Comment

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 11:18am

Pharmaceutical waste contaminates India's main rivers

India's major rivers are thick with heavy metals, dyes, toxic chemicals and pharmaceutical products, a study shows.

The study, published in December in the journal Science of the Total Environment, found high concentrations of pharmaceutical waste as well as toxic metals such as arsenic, zinc, chromium, lead and nickel in the Cauvery, a major river in southern India.

These  observations are alarming. The researchers' environmental risk assessment has shown that pharmaceutical contaminants pose medium to high risk to selected aquatic lifeforms of the riverine system.

Pharmaceutical products found in the river included anti-inflammatories like ibuprofen and diclofenac, anti-hypertensives such as atenolol and isoprenaline, enzyme inhibitors like perindopril, stimulants like caffeine, antidepressants such as carbamazepine, and antibiotics such as ciprofloxacin.

India is among the world's biggest producers of pharmaceutical drugs. Although there are regulations governing effluents from manufacturing units, there is very little real monitoring by regulators such as the state pollution control boards. For instance, the Karnataka State Pollution Control Board takes samples only once in every three months and only during the day whereas illegal dumping of effluents is often done at night.

"Clearly there is a need to ensure that wastewater treatment systems are working optimally to reduce the level of contaminants reaching the rivers," the researchers said.

Jayakumar Renganathan et al, Spatio-temporal distribution of pharmaceutically active compounds in the River Cauvery and its tributaries, South India, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.149340

https://phys.org/news/2021-12-pharmaceutical-contaminates-india-mai...

Provided by SciDev.Net

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 11:12am

When variations in Earth's orbit drive biological evolution

Coccolithophores are microscopic algae that form tiny limestone plates, called coccoliths, around their single cells. The shape and size of coccoliths varies according to the species. After their death, coccolithophores sink to the bottom of the ocean and their coccoliths accumulate in sediments, which faithfully record the detailed evolution of these organisms over geological time.

A team of scientists led by CNRS researchers show, in an article published in Nature on December 1, 2021, that certain variations in Earth's orbit have influenced the evolution of coccolithophores. To achieve this, no less that 9 million coccoliths, spanning an interval of 2.8 million years and several locations in the tropical ocean, were measured and classified using automated microscope techniques and artificial intelligence.

The researchers observed that coccoliths underwent cycles of higher and lower diversity in size and shape, with rhythms of 100 and 400 thousand years. They also propose a cause: the more or less circular shape of Earth's orbit around the Sun, which varies at the same rhythms. Thus, when Earth's orbit is more circular, as is the case today (this is known as low eccentricity), the equatorial regions show little seasonal variation and species that are not very specialized dominate all the oceans. Conversely, as eccentricity increases and more pronounced seasons appear near the equator, coccolithophores diversify into many specialized species, but collectively produce less limestone.

Crucially, due to their abundance and global distribution, these organisms are responsible for half of the limestone (calcium carbonate, partly composed of carbon) produced in the oceans and therefore play a major role in the carbon cycle and in determining ocean chemistry. It is therefore likely that the cyclic abundance patterns of these limestone producers played a key role in ancient climates, and may explain hitherto mysterious climate variations in past warm periods.

In other words, in the absence of ice, the biological evolution of micro-algae could have set the tempo of climates. This hypothesis remains to be confirmed.

Luc Beaufort, Cyclic evolution of phytoplankton forced by changes in tropical seasonality, Nature (2021). DOI: 10.1038/s41586-021-04195-7. www.nature.com/articles/s41586-021-04195-7

https://phys.org/news/2021-12-variations-earth-orbit-biological-evo...

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 11:08am

Safely delivering radiation to cancer patients in a 'FLASH'

Researchers at Lawrence Livermore National Laboratory (LLNL) have shown for the first time the potential for linear induction accelerators (LIAs) to deliver effective, targeted doses of "FLASH" radiation to cancer patients. The new technique selectively kills cancer cells with minimal damage to healthy cells. The approach is outlined in a Scientific Reports paper.

Efforts to deliver a rapid, high, targeted dose of therapy radiation, or FLASH radiotherapy (FLASH-RT) at the required depth, have required large, complex machines the size of gymnasiums and have so far proven impractical for clinical use. In the Scientific Reports paper, the authors note that LIAs powerful enough to deliver the necessary dose rate to cancer cells can be built only 3 meters long.

Researchers have combined technologies that were developed for weapons—either diagnostics or weapon design itself—and spinning off something that could potentially be a major breakthrough in cancer radiotherapy.

 Stephen E. Sampayan et al, Megavolt bremsstrahlung measurements from linear induction accelerators demonstrate possible use as a FLASH radiotherapy source to reduce acute toxicity, Scientific Reports (2021). DOI: 10.1038/s41598-021-95807-9

https://phys.org/news/2021-12-safely-cancer-patients.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 11:03am

Study links high cholesterol, cardiovascular disease to plastics

Plastics, part of modern life, are useful but can pose a significant challenge to the environment and may also constitute a health concern. Indeed, exposure to plastic-associated chemicals, such as base chemical bisphenol A and phthalate plasticizers, can increase the risk of human cardiovascular disease. What underlying mechanisms cause this, however, remain elusive.

Now in a mouse study,  researchers found a phthalate—a chemical used to make plastics more durable—led to increased plasma cholesterol levels. Dicyclohexyl phthalate, or DCHP, strongly binds to a receptor called pregnane X receptor, or PXR.

DCHP 'turns on' PXR in the gut, inducing the expression of key proteins required for cholesterol absorption and transport. Experiments show that DCHP elicits high cholesterol by targeting intestinal PXR signaling.

Mice exposed to DCHP had in their intestines higher circulating "ceramides"—a class of waxy lipid molecules associated with increased cardiovascular disease risk  in humans—in a way that was PXR-dependent.

This, too, points to the potentially important role of PXR in contributing to the harmful effects of plastic-associated chemicals on cardiovascular health in humans.

"Effects of dicyclohexyl phthalate exposure on PXR activation and lipid homeostasis in miceEnvironmental Health Perspectives (2021). " doi.org/10.1289/EHP9262

https://medicalxpress.com/news/2021-12-links-high-cholesterol-cardi...

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 10:57am

Engineers create perching bird-like robot

Comment by Dr. Krishna Kumari Challa on December 1, 2021 at 10:42am

Filtering microplastics trash from water with acoustic waves

Microplastics are released into the environment by cosmetics, clothing, and industrial processes or from larger plastic products as they break down naturally.

The pollutants eventually find their way into rivers and oceans, posing problems for marine life. Filtering and removing the small particles from water is a difficult task, but acoustic waves may provide a solution.

A research team used two speakers to create acoustic waves. The force produced by the waves separates the microplastics from the water by creating pressure on a tube of inflowing water. As the tube splits into three channels, the microplastic particles are pressed toward the center as the clean water flows toward the two outer channels.

The prototype device cleaned 150 liters per hour of polluted water and was tested with three different microplastics. Each plastic was filtered with a different efficiency, but all were above 56% efficient in pure water and 58% efficient in seawater. Acoustic frequency, speaker-to-pipe distance, and density of the water all affected the amount of force generated and therefore the efficiency.

The acoustic waves may impact marine life if the wave frequency is in the audible range. The group is currently studying this potential issue.

Source: News Agencies

https://www.eurekalert.org/news-releases/935152

acousticalsociety.org/asa-meetings/

https://phys.org/news/2021-11-filtering-microplastics-trash-acousti...

Comment by Dr. Krishna Kumari Challa on December 1, 2021 at 10:18am

A research team developed mRNA delivery nanoparticles that mimic the flu virus's ability to do this. To make the nanoparticles, the researchers genetically engineered cells in the lab to express the hemagglutinin protein on their cell membranes. They then separated the membranes from the cells, broke them into tiny pieces, and coated them onto nanoparticles made from a biodegradable polymer that has been pre-packed with mRNA molecules inside.

The finished product is a flu virus-like nanoparticle that can get into a cell, break out of the endosome, and free its mRNA payload to do its job: Instruct the cell to produce proteins.

The researchers tested the nanoparticles in mice. The flu-virus like nano particles effectively delivered their mRNA payloads into cells in vivo.

 Joon Ho Park et al, Virus‐Mimicking Cell Membrane‐Coated Nanoparticles for Cytosolic Delivery of mRNA, Angewandte Chemie International Edition (2021). DOI: 10.1002/anie.202113671

https://phys.org/news/2021-11-flu-virus-shells-delivery-mrna.html?u...

Part 2

Comment by Dr. Krishna Kumari Challa on December 1, 2021 at 10:16am

Flu virus shells could improve delivery of mRNA into cells

Nanoengineers  have developed a new and potentially more effective way to deliver messenger RNA (mRNA) into cells. Their approach involves packing mRNA inside nanoparticles that mimic the flu virus—a naturally efficient vehicle for delivering genetic material such as RNA inside cells.

The new mRNA delivery nanoparticles are described in a paper published recently in the journal Angewandte Chemie International Edition.

The work addresses a major challenge in the field of drug delivery: Getting large biological drug molecules safely into cells and protecting them from organelles called endosomes. These tiny acid-filled bubbles inside the cell serve as barriers that trap and digest large molecules that try to enter. In order for biological therapeutics to do their job once they are inside the cell, they need a way to escape the endosomes.

Current mRNA delivery methods do not have very effective endosomal escape mechanisms, so the amount of mRNA that actually gets released into cells and shows effect is very low. The majority of them are wasted when they get administered. Achieving efficient endosomal escape would be a game changer for mRNA vaccines and therapies. If you can get more mRNA into cells, this means you can take a much lower dose of an mRNA vaccine, and this could reduce side effects while achieving the same efficacy. It could also improve delivery of small interfering RNA (siRNA) into cells, which is used in some forms of gene therapy.

In nature, viruses do a very good job of escaping the endosome. The influenza A virus, for example, has a special protein on its surface called hemagglutinin, that when activated by acid inside the endosome, triggers the virus to fuse its membrane with the endosomal membrane. This opens up the endosome, enabling the virus to release its genetic material  into the host cell without getting destroyed.

part 1

Comment by Dr. Krishna Kumari Challa on November 30, 2021 at 9:18am

Living robots that can reproduce!

To persist, life must reproduce.

Over billions of years, organisms have evolved many ways of replicating, from budding plants to sexual animals to invading viruses.

Now scientists have discovered an entirely new form of biological reproduction—and applied their discovery to create the first-ever, self-replicating living robots.

The same team that built the first living robots ("Xenobots," assembled from frog cells—reported in 2020) has discovered that these computer-designed and hand-assembled organisms can swim out into their tiny dish, find single cells, gather hundreds of them together, and assemble "baby" Xenobots inside their Pac-Man-shaped "mouth"—that, a few days later, become new Xenobots that look and move just like themselves.

And then these new Xenobots can go out, find cells, and build copies of themselves. Again and again.

Sam Kriegman el al., "A scalable pipeline for designing reconfigurable organisms," PNAS (2019). www.pnas.org/cgi/doi/10.1073/pnas.1910837117

https://techxplore.com/news/2020-01-team-robots.html

Comment by Dr. Krishna Kumari Challa on November 30, 2021 at 9:10am

Salt grain size camera!

Micro-sized cameras have great potential to spot problems in the human body and enable sensing for super-small robots, but past approaches captured fuzzy, distorted images with limited fields of view.

But now, researchers  have overcome these obstacles with an ultracompact camera the size of a coarse grain of salt. The new system can produce crisp, full colour images on par with a conventional compound camera lens 500,000 times larger in volume, the researchers reported in a paper published Nov. 29 in Nature Communications.

Enabled by a joint design of the camera's hardware and computational processing, the system could enable minimally invasive endoscopy with medical robots to diagnose and treat diseases, and improve imaging for other robots with size and weight constraints. Arrays of thousands of such cameras could be used for full-scene sensing, turning surfaces into cameras.

While a traditional camera uses a series of curved glass or plastic lenses to bend light rays into focus, the new optical system relies on a technology called a metasurface, which can be produced much like a computer chip. Just half a millimeter wide, the metasurface is studded with 1.6 million cylindrical posts, each roughly the size of the human immunodeficiency virus (HIV).

Each post has a unique geometry, and functions like an optical antenna. Varying the design of each post is necessary to correctly shape the entire optical wavefront. With the help of machine learning-based algorithms, the posts' interactions with light combine to produce the highest-quality images and widest field of view for a full-color metasurface camera developed to date.

A key innovation in the camera's creation was the integrated design of the optical surface and the signal processing algorithms that produce the image. This boosted the camera's performance in natural light conditions.

 Ethan Tseng et al, Neural nano-optics for high-quality thin lens imaging, Nature Communications (2021). DOI: 10.1038/s41467-021-26443-0

https://phys.org/news/2021-11-camera-size-salt-grain.html?utm_sourc...

• ‹ Previous
• 1
• …
• 576
• 577
• 578
• 579
• 580
• …
• 1112
• Next ›
• Page