Comment

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 8:24am

DNA might replace barcodes to tag art, voter ballots: study

Easy-to-remove barcodes and QR codes used to tag everything from T-shirts to car engines may soon be replaced by a tagging system based on DNA and invisible to the naked eye, according to scientists.

The DNA-based system could help anti-forgery efforts, according to researchers who said thieves struggle to find or tamper with a transparent splash of DNA on valuable or vulnerable items, such as election ballots, works of art, or secret documents.

In an article published in Nature Communications, researchers said that the molecular tagging system, called Porcupine, is -- unlike most alternatives -- cost-effective.

Using DNA for tagging objects has been out of reach in the past because it is expensive and time consuming to write and read, and requires expensive lab equipment.

Porcupine gets around this by prefabricating fragments of DNA that users can mix together arbitrarily to create new tags, the researchers said.

Instead of radio waves or printed lines, the Porcupine tagging scheme relies on a set of distinct DNA strands called molecular bits, or 'molbits' for short.

To encode an ID, scientists pair each digital bit with a molbit.

If the digital bit is 1, they add its molbit to the tag, and if it's 0 they leave it out. Then they can dry it until it's ready to be decoded later. Once the item has been tagged, it can then be shipped or stored.

When someone wants to read the tag, water is added to rehydrate the molecular tag, which is read by a nanopore sequencer -- a DNA-reading device smaller than an Iphone.

The name Porcupine comes from a play on words (PORE-cupine, as in nanopore) and the idea that porcupines can 'tag' objects, and critters that dare to get too close.

Unlike existing systems to tag objects, DNA tags are undetectable by sight or touch. Practically speaking, this means they are difficult to tamper with.

1. Kathryn Doroschak, Karen Zhang, Melissa Queen, Aishwarya Mandyam, Karin Strauss, Luis Ceze, Jeff Nivala. Rapid and robust assembly and decoding of molecular tags with DNA-based nanopore signatures. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-19151-8

https://researchnews.cc/news/3442/DNA-might-replace-barcodes-to-tag...

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 7:42am

A potential new treatment for premature aging diseases keeps stem cells fresh longer

The drug helps keep stem cells telomeres long, preventing them from aging too quickly.

The ends of our DNA, called telomeres, get shorter as we age. Our cells lose a bit of telomere every time they divide. This shortening is a normal and needed process that serves a protective function against cancer. This is because the older our cells get, the more likely they are to have accumulated damage or mutations that make them function incorrectly. Telomere shortening helps to take old cells that are reaching their “best before date” off the shelf before they can cause trouble.

But this can backfire: cells can shorten their telomeres too quickly, age rapidly, and die. This is what causes a subset of genetic premature aging diseases, including idiopathic pulmonary fibrosis, forms of aplastic anemia, and a rare disease called dyskeratosis congenita. Unfortunately, there are currently no available drug-based therapies for treating telomere-driven premature aging diseases.

Now, a candidate drug has found a new potential purpose in treating premature aging disease. 

This drug, called RG7834, was originally identified as an inhibitor of hepatitis B virus (HBV). While it has been found to be well-tolerated in short-term administration to living organisms (like rodents and primates), this drug does not cure HBV, and is not yet publicly available. Interestingly, the host cell proteins affected by RG7834 are two enzymes that modify many different RNAs. These enzymes can cause degradation of host cell RNA — so RG7834 keeps RNA around that the cell otherwise might get rid of.

https://massivesci.com/articles/telomere-telomerase-rna-drug-premat...

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 6:52am

**SARS-CoV-2 uses 'genome origami' to infect and replicate inside host cells

Scientists at the University of Cambridge, in collaboration with Justus-Liebig University, Germany, have uncovered how the genome of SARS-CoV-2—the coronavirus that causes COVID-19—uses genome origami to infect and replicate successfully inside host cells. This could inform the development of effective drugs that target specific parts of the virus genome, in the fight against COVID-19.

Most current work to find drugs and vaccines for COVID-19 is focused on targeting the proteins of the virus. Because the shape of the RNA molecule is critical to its function, targeting the RNA directly with drugs to disrupt its structure would block the lifecycle and stop the virus replicating.

the team uncovered the entire structure of the SARS-CoV-2 genome inside the host cell, revealing a network of RNA-RNA interactions spanning very long sections of the genome. Different functional parts along the genome need to work together despite the great distance between them, and the new structural data shows how this is accomplished to enable the coronavirus life cycle and cause disease.

"The RNA genome of coronaviruses is about three times bigger than an average viral RNA genome—it's huge

In all cells the genome holds the code for the production of specific proteins, which are made when a molecular machine called a ribosome runs along the RNA reading the code until a 'stop sign' tells it to terminate. In coronaviruses, there is a special spot where the ribosome only stops 50% of the times in front of the stop sign. In the other 50% of cases, a unique RNA shape makes the ribosome jump over the stop sign and produce additional viral proteins. By mapping this RNA structure and the long-range interactions involved, the new research uncovers the strategies by which coronaviruses produce their proteins to manipulate our cells.

The genome of most human viruses is made of RNA rather than DNA. Ziv developed methods to investigate such long-range interactions across viral RNA genomes inside the host cells, in work to understand the Zika virus genome. This has proved a valuable methodological basis for understanding SARS-CoV-2.

 Omer Ziv et al, The short- and long-range RNA-RNA Interactome of SARS-CoV-2, Molecular Cell (2020). DOI: 10.1016/j.molcel.2020.11.004

https://phys.org/news/2020-11-sars-cov-genome-origami-infect-replic...

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 6:32am

**Has the hidden matter of the universe been discovered?

Astrophysicists consider that around 40% of the ordinary matter that makes up stars, planets and galaxies remains undetected, concealed in the form of a hot gas in the complex cosmic web. Today, scientists at the Institut d'Astrophysique Spatiale (CNRS/Université Paris-Saclay) may have detected, for the first time, this hidden matter through an innovative statistical analysis of 20-year-old data.

 H. T Tanimura et al. First detection of stacked X-ray emission from cosmic web filaments, Astronomy & Astrophysics (2020). DOI: 10.1051/0004-6361/202038521

https://phys.org/news/2020-11-hidden-universe.html?utm_source=nwlet...

--

**Coronavirus testing finally gathers speed

The imminent large-scale rollout of rapid coronavirus tests promises to aid public health responses to COVID-19 — but a rapid home test remains elusive.

https://www.nature.com/articles/d41587-020-00021-z?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 6:21am

Gold-catalyzed reaction releases an active drug to kill cancer cells

Drugs that are activated inside the body with catalytic quantities of gold could offer a new option for treating cancer and other diseases.

Using metals to convert masked "prodrugs" into their active forms inside the body is an emerging area of biomedical research. These drug-release reactions are designed to be triggered by metals that are not naturally present in the body, providing a new way to trigger drug release that promises to increase the efficacy and reduce the side effects of a therapy.

Kenward Vong et al. Bioorthogonal release of anticancer drugs via gold-triggered 2-alkynylbenzamide cyclization, Chemical Science (2020). DOI: 10.1039/d0sc04329j

https://phys.org/news/2020-11-gold-catalyzed-reaction-drug-cancer-c...

Comment by Dr. Krishna Kumari Challa on November 7, 2020 at 6:18am

Seeing dark matter in a new light

A small team of astronomers have found a new way to 'see' the elusive dark matter haloes that surround galaxies, with a new technique 10 times more precise than the previous-best method.

Scientists currently estimate that up to 85% of the mass in the universe is effectively invisible. This "dark matter" cannot be observed directly, because it does not interact with light in the same way as the ordinary matter that makes up stars, planets, and life on Earth.

So how do we measure what cannot be seen? The key is to measure the effect of gravity that the dark matter produces. It's like looking at a flag to try to know how much wind there is. You cannot see the wind, but the flag's motion tells you how strongly the wind is blowing.

The new research focuses on an effect called weak gravitational lensing, which is a feature of Einstein's general theory of relativity. The dark matter will very slightly distort the image of anything behind it.

Weak gravitational lensing is already one of the most successful ways to map the dark matter content of the Universe. Now, the team has used the ANU 2.3m Telescope in Australia to map how gravitationally lensed galaxies are rotating. Because we know how stars and gas are supposed to move inside galaxies, we know roughly what that galaxy should look like. By measuring how distorted the real galaxy images are, then we can figure out how much dark matter it would take to explain what we see. The new research shows how this velocity information enables a much more precise measurement of the lensing effect than is possible using shape alone.

Pol Gurri et al. The first shear measurements from precision weak lensing, Monthly Notices of the Royal Astronomical Society (2020). DOI: 10.1093/mnras/staa2893

https://phys.org/news/2020-11-dark.html?utm_source=nwletter&utm...

Comment by Dr. Krishna Kumari Challa on November 6, 2020 at 8:18am

The Science Communication Crisis

Comment by Dr. Krishna Kumari Challa on November 6, 2020 at 8:13am

 2020 Heroes of Chemistry

Comment by Dr. Krishna Kumari Challa on November 6, 2020 at 8:05am

Startling Case Study Finds Asymptomatic COVID-19 Carrier Who Shed Virus For 70 Days

A team of researchers and doctors has now reported the case of one woman with leukemia who had no symptoms of COVID-19 but 70 days after her first positive test, she was still shedding infectious SARS-CoV-2 particles.

This result is much longer than previous reports of hospitalised adults found shedding infectious SARS-CoV-2 virus up to 20 days after their COVID-19 diagnosis, plus other accounts of people shedding genetic material from the virus up to 63 days after their symptoms first appeared.

The new report should alert doctors and public health experts alike to the fact that people without symptoms and with weakened immune systems, such as cancer patients, can seemingly shed the SARS-CoV-2 virus for a really long time. In this case, even months.

"Although it is difficult to extrapolate from a single patient, our data suggest that long-term shedding of infectious virus may be a concern in certain immunocompromised patients," the research team wrote in their paper describing the case.

https://www.cell.com/cell/fulltext/S0092-8674(20)31456-2

https://www.sciencealert.com/case-study-reveals-rare-patient-who-sh...

Comment by Dr. Krishna Kumari Challa on November 6, 2020 at 7:54am

How Some Vaccines Protect Against More than Their Targets

As researchers test existing vaccines for nonspecific protection against COVID-19, immunologists are working to understand how some inoculations protect against pathogens they weren’t designed to fend off.

https://www.the-scientist.com/features/how-some-vaccines-protect-ag...

• ‹ Previous
• 1
• …
• 725
• 726
• 727
• 728
• 729
• …
• 1081
• Next ›
• Page