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Comment by Dr. Krishna Kumari Challa on June 21, 2017 at 9:41am

Potent Inhibitor of Drug-Resistant HIV-1 Strains Identified from the Medicinal Plant Justicia gendarussa

Justicia gendarussa, a medicinal plant collected in Vietnam, was identified as a potent anti-HIV-1 active lead from the evaluation of over 4500 plant extracts. Bioassay-guided separation of the extracts of the stems and roots of this plant led to the isolation of an anti-HIV arylnaphthalene lignan (ANL) glycoside, patentiflorin A (1). Evaluation of the compound against both the M- and T-tropic HIV-1 isolates showed it to possess a significantly higher inhibition effect than the clinically used anti-HIV drug AZT. Patentiflorin A and two congeners were synthesized, de novo, as an efficient strategy for resupply as well as for further structural modification of the anti-HIV ANL glycosides in the search for drug leads. Subsequently, it was determined that the presence of a quinovopyranosyloxy group in the structure is likely essential to retain the high degree of anti-HIV activity of this type of compounds. Patentiflorin A was further investigated against the HIV-1 gene expression of the R/U5 and U5/gag transcripts, and the data showed that the compound acts as a potential inhibitor of HIV-1 reverse transcription. Importantly, the compound displayed potent inhibitory activity against drug-resistant HIV-1 isolates of both the nucleotide analogue (AZT) and non-nucleotide analogue (nevaripine). Thus, the ANL glycosides have the potential to be developed as novel anti-HIV drugs.

http://pubs.acs.org/doi/abs/10.1021/acs.jnatprod.7b00004

Comment by Dr. Krishna Kumari Challa on June 17, 2017 at 9:10am

Quantum communication...

A successful quantum communication network will rely on the ability to distribute entangled photons over large distances between receiver stations. So far, free-space demonstrations have been limited to line-of-sight links across cities or between mountaintops. Scattering and coherence decay have limited the link separations to around 100 km. Yin et al. used the Micius satellite, which was launched last year and is equipped with a specialized quantum optical payload. They successfully demonstrated the satellite-based entanglement distribution to receiver stations separated by more than 1200 km. The results illustrate the possibility of a future global quantum communication network.

http://science.sciencemag.org/content/356/6343/1140

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Scientists have solved a centuries-old mystery of "bright nights" - an unusual glow that appears in the sky after dark and lets observers see distant mountains, read a newspaper or check their watch.

Researchers suggest that when waves in the upper atmosphere converge over specific locations on Earth, it amplifies naturally occurring airglow, a faint light in the night sky that often appears green due to the activities of atoms of oxygen in the high atmosphere.

Normally, people do not notice airglow, but on bright nights it can become visible to the naked eye, producing the unexplained glow detailed in historical observations.

Modern observations of bright nights from Earth are practically nonexistent light pollution. Even devoted airglow researchers have never seen a true bright night.

However, even before the advent of artificial lighting, bright nights were rare and highly localised.

Researchers could see bright night events reflected in airglow data from the Wind Imaging Interferometer (WINDII), an instrument once carried by NASA's Upper Atmosphere Research Satellite (1991-2005).

They searched for mechanisms that would cause airglow to increase to visible levels at specific locations.

Airglow comes from emissions of different colors of light from chemical reactions in the upper reaches of the atmosphere. The green portion of airglow occurs when light from the sun splits apart molecular oxygen into individual oxygen atoms.

When the atoms recombine, they give off the excess energy as photons in the green part of the visible light spectrum, giving the sky a greenish tinge.

To find factors that would cause peaks in airglow and create bright nights, researchers searched two years of WINDII data for unusual airglow profiles.

They identified 11 events where WINDII detected a spike in airglow levels that would be visible to the human eye, two of which they describe in detail in the study.

Finally, the researchers matched up the events with the ups and downs of zonal waves, large waves in the upper atmosphere that circle the globe and are impacted by weather.

Comment by Dr. Krishna Kumari Challa on June 15, 2017 at 2:17pm

Update on flourescent light treatment of babies with jaundice  ...

Update

Preemies aren’t the only babies at risk for jaundice. About 60 percent of full-term infants also develop the condition. Severe cases can cause brain damage if untreated. But today, some researchers warn that light therapy, now widely used, may not work for babies whose bilirubin levels are very high. And studies have begun to suggest a link between the therapy and certain childhood cancers . Though the risk of developing cancer is small, doctors should be cautious about prescribing the treatment, researchers wrote in 2016 in Pediatrics.

Phototherapy may slightly increase the risk of cancer in infancy, although the absolute risk increase is small. This risk should be considered when making phototherapy treatment decisions, especially for infants with bilirubin levels below current treatment guidelines.

A.C. Wickremasinghe et al. Neonatal phototherapy and infantile cancer. Pediatrics. Vol. 137, June 2016, e20151353. doi: 10.1542/peds.2015-1353.

Comment by Dr. Krishna Kumari Challa on June 14, 2017 at 8:10am

In a study published in Nature Medicine, researchers have confirmed that the targeted removal of senescent cells can delay the development of osteoarthritis in mice. This research was been led by Dr. Kim Chaekyu of the Johns Hopkins University School of Medicine, who is now at the Ulsan National Institute of Science and Technology (UNIST), and Dr. Jeon Ok Hee of the Johns Hopkins University School of Medicine. In the study, the research team describe a drug candidate that alleviates age-related degenerative joint conditions such as osteoarthritis by selectively destroying senescent cells. Their findings suggest that the selective removal of old cells from joints could reduce the development of post-traumatic osteoarthritis and allow new cartilage to grow and repair joints. 

Local clearance of senescent cells attenuates the development of post-traumatic osteoarthritis and creates a pro-regenerative environment

https://www.nature.com/nm/journal/v23/n6/full/nm.4324.html

Comment by Dr. Krishna Kumari Challa on June 11, 2017 at 9:32am

Contageous Vaccines! Future Perfect! Yes, you read it right!

When enough people get vaccinated, infectious diseases can’t spread easily and everyone benefits from herd immunity. 

But it’s hard to reach enough people for this to happen, especially in areas with poor public health infrastructure. So scientists are taking a leaf from the virus playbook. They’re devising vaccines and antiviral therapies that can spread from host to host.

These transmissible vaccines will likely first be used in animals that carry diseases that can infect people. Some may use a weakened version of the virus, or attach a piece of the pathogen to a benign virus. Other treatments are aimed at people who are already infected and will prey on the virus dwelling in their cells.

It’s early days for these kinds of vaccines and therapies, and scientists still have to show that they are effective and safe to use in wildlife or people. But they could tamp down the spread of HIV and other contagious diseases, and immunize people who would not otherwise be protected. Plus this strategy would be cheaper than vaccinating everyone by hand.

In some countries the vaccine for polio is given as an injection that carries dead poliovirus. But there’s another form of the vaccine that is taken by mouth and uses a weakened—but live—version of the virus. This version can briefly spread to other people before dying out. The World Health Organization has relied on the oral polio vaccine for its efforts to wipe out the disease worldwide.

But there is a drawback. Rarely, the live vaccine can mutate enough to revert back to its virulent form. The oral polio vaccine carries three strains of the virus, one of which has been eradicated in the wild but is also most likely to cause this problem. The WHO is switching to a vaccine that has only the two safer strains.

Many vaccines use live but weakened versions of the virus, including those for measles and chicken pox. The process that disables the virus so it can’t cause sickness also makes it less able to spread.

But it’s likely that some of these vaccines are still a little bit transmissible. This hasn’t been studied in depth, though. When these vaccines are designed, the focus is on making sure they can’t make people sick. 

If we did intentionally design transmissible vaccines, they might be more likely than regular vaccines to revert. That’s because they reach more people and have a chance to replicate and make new generations. That means more chances for mutations and evolution. One way around this would be to make a live vaccine that is only weakly transmissible. This vaccine would only spread a little bit before dying out. This kind of vaccine wouldn’t be able to eradicate a disease, but fewer people would need to be directly vaccinated. A weakly transmissible vaccine would still make a major dent in disease outbreaks.

Source: Popsci

Comment by Dr. Krishna Kumari Challa on June 1, 2017 at 5:08am

We all know that light travels faster than sound. That is why we see lightening first and then hear the sound of thunder later. Light travels roughly 800,000 times as fast as sound.

But an interesting thing about meteors is you can hear the sound and see their light at the same time! How is this possible? Now scientists explained the mystery...

The sound waves aren’t coming from the meteor itself, atmospheric scientists Michael Kelley of Cornell University and Colin Price of Tel Aviv University propose April 16 in Geophysical Research Letters. As the leading edge of the falling space rock vaporizes, it becomes electrically charged. The charged head produces an electric field, which yields an electric current that blasts radio waves toward the ground. As a type of electromagnetic radiation, radio waves travel at the speed of light and can interact with metal objects near the ground, generating a whistling sound that people can hear.

Just 0.1 percent of the radio wave energy needs to be converted into sound for the noise to be audible as the meteor zips by, the researchers estimate. This same process could explain mysterious noises heard during the aurora borealis, or northern lights. Like meteors, auroras have been known to emit radio wave bursts.

On the electrophonic generation of audio frequency sound by meteors

 http://onlinelibrary.wiley.com/doi/10.1002/2017GL072911/abstract

Comment by Dr. Krishna Kumari Challa on May 24, 2017 at 7:07am

Do statins help you avoid heart attacks and strokes? That depends on various things says a recent study

The benefits of statins for people older than 75 remain unclear, a new analysis finds. Statins did not reduce heart attacks or coronary heart disease deat... from any cause, compared with people not taking statins, researchers report online May 22 in JAMA Internal Medicine.

Recently published guidelines cited insufficient data to recommend statins for people older than age 75 who don’t have a history of cardiovascular disease. The new analysis considered a subset of older adults enrolled in a study of heart attack prevention and mortality conducted from 1994 to 2002. The sample included 2,867 adults ages 65 and older who had hypertension, 1,467 of whom took a statin.

There was no meaningful difference in the frequency of heart attacks or coronary heart disease deaths between those who took statins and those who did not. There was also no significant difference in deaths from any cause, both overall and among participants ages 65 to 74 or those 75 and older.

Statin use may be associated with muscle damage and fatigue, which could especially impact older adults and put them at higher risk for physical decline, the authors say.

Science news

Comment by Dr. Krishna Kumari Challa on May 10, 2017 at 9:10am

Smile and the world thinks you are older! Don't believe? here is the proof!

A new study shows that smiling can make you appear to be two years older than if you wear a poker face. And if you reacted to that finding with a look of surprise - well, that expression might just have dropped years from your visage.

"We associate smiling with positive values and youth," said study co-author Melvyn Goodale, director of the Brain and Mind Institute at Western University. "Think of all the skin-care and toothpaste companies that sell the same idea every day."

But this study -- in which researchers flashed images of people with smiling, neutral and surprised expressions -- showed the opposite: participants perceived the surprised faces as the youngest and smiling faces the oldest.

"The striking thing was that when we asked participants afterwards about their perceptions, they erroneously recalled that they had identified smiling faces as the youngest ones," Goodale said. "They were completely blind to the fact they had 'aged' the happy-looking faces. Their perceptions and their beliefs were polar opposites."

Goodale said the aging effect of a smile stems from people's inability to ignore the wrinkles that form around the eyes during smiling. A look of surprise, on the other hand, smooths any wrinkles.

"It may seem counter-intuitive, but the study shows that people can sincerely believe one thing and then behave in a completely different way," Goodale said.

The study, "The effects of smiling on perceived age defy belief" is newly published in the journal Psychonomic Bulletin and Review. 

source: Eurekalert

Comment by Dr. Krishna Kumari Challa on May 9, 2017 at 8:39am

Inhaled Nanoparticles Accumulate at Sites of Vascular Disease

Inhaled nanoparticles can cross the lungs, entering the bloodstream, and accumulate in blood vessels and other bodily sites vulnerable to cardiovascular disease, a new study suggests. 
 
People around the world are constantly exposed to nanoparticles mostly emitted by vehicle exhaust, but the risks are greater in crowded Asian cities, which are seeing a dramatic rise in the number of vehicles on the roads.
 
In the study — the results of which were published on 26 April in ACS Nano — it was shown that healthy volunteers exposed to gold nanoparticles retained them in the body for as long as three months. Experiments on mice also reveal that nanoparticles accumulate in the liver and blood vessels.
 
Results from human studies have been inconsistent thus far, the authors write. But evidence showing that nanoparticles enter the blood circulation by escaping the lungs “provides a direct mechanism that can explain the link between environmental nanoparticles and cardiovascular disease”. It also has implications for managing potential risks of engineered nanoparticles, they add.
 
The link between environmental nanoparticles and cardiovascular disease could be explained by gold particles detected in surgical specimens of diseased carotid artery from patients at risk of stroke and at sites of vascular inflammation, according to the study.

http://pubs.acs.org/doi/abs/10.1021/acsnano.6b08551

Comment by Dr. Krishna Kumari Challa on May 9, 2017 at 7:23am

Some farming practices destroy Earthworms...

The digging, stirring and overturning of soil by conventional ploughing in tillage farming is severely damaging earthworm populations around the world, say scientists.

The findings published in the scientific journal Global Change Biology show a systematic decline in earthworm populations in soils that are ploughed every year. The deeper the soil is disturbed the more harmful it is for the earthworms.

The scientists from the University of Vigo, Spain, and University College Dublin, Ireland, analysed 215 field studies from across 40 countries dating back as far as 1950. Each of the studies investigated earthworm populations under conventional tillage and other forms of reduced tillage.

According to the findings, the earthworm populations most vulnerable to tillage are larger earthworms that move between layers of soil and create permanent burrows between them (anecic earthworms). Small earthworms that live in the top layers of soil and convert debris to topsoil (epigeic earthworms) were also found to be highly susceptible.

Farming practices that involve no-tillage, Conservation Agriculture and shallow non-inversion tillage were shown to significantly increase earthworm populations. The scientists note that these reduced tillage practices are increasingly being adopted world-wide due to their environmental benefits in terms of erosion control and soil protection.

Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta-analysis

http://onlinelibrary.wiley.com/doi/10.1111/gcb.13744/abstract;jsess...

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