Knowledge Update

New York, Sep 7 (IANS) While electric fans keep young adults cooler by increasing the evaporation of sweat, they may, surprisingly, have the opposite effect for those above the age of 60, suggests new research.

The heart rate and internal temperature of seniors exposed to 41.6 degree Celsius temperatures and increasing humidity levels climbed even higher when they tried to cool off with fans -- instead of falling as expected, according to study findings reported in the journal JAMA.

"Although differences were small, the cumulative effect could become clinically important during prolonged heat exposure, such as during extreme heat waves," said Craig Crandall, Professor of Internal Medicine at University of Texas Southwestern Medical Center in the US.

"We know that fans keep young adults cooler by increasing the evaporation of sweat," Crandall said. 

"We surmise that age-related impairments in sweating capacity make fans an ineffective means of cooling for the elderly during exceptionally hot days, and may, in fact, increase thermal and cardiac strain," Crandall noted.

Researchers studied the physiological responses of a small group of elderly patients in a high-heat, high-humidity environment. 

Participants between the ages of 60 and 80 were observed for approximately two hours in a room with the temperature set at a sweltering 41.6 degrees Celsius and a humidity level that was gradually increased from 30 per cent to 70 per cent. 

Not surprisingly, both heart rate and internal body temperature rose as the humidity level in the room rose. 

The eight individuals in the study were tested under those conditions without a fan and, on a separate occasion, with an electric fan. 

Unexpectedly, the participants' heart rates were 10 beats per minute higher and their internal temperatures marginally higher when a fan was part of the experimental environment. 

Although these findings suggest that fan use may be counterproductive for seniors during heat waves, the investigators propose that fan use may still be beneficial under less extreme environmental conditions, though this needs to be confirmed.

New York, July 31 (IANS) In their bid to design new bio-materials that promote tissue regeneration, scientists have identified how inflammation, when precisely controlled, is crucial for bone repair.

The findings showed that a new type of ceramic scaffold causes inflammatory cells to behave in a way that is more regenerative than scaffolds that are currently used clinically.

The reason can be attributed to macrophages -- swallowing white blood cells that digest foreign particles, the researchers said.

"We wanted to know why these scaffolds were successful and to understand the contributions of macrophages to that process," said Kara Spiller, Associate Professor Drexel University, in Pennsylvania, the US.

The findings showed that the new ceramic scaffolds caused macrophages to transform into an M2c phenotype, meaning they express genes associated with re-modelling.

This behaviour was not seen in the scaffolds that have been approved to be used in humans.

Further, the study also found that macrophages must be in direct contact with the scaffold in order to regenerate tissue.

"The macrophages degrade the scaffolds and shape them into something new," Spiller said.

Determining why certain scaffolds are successful in re-growing bone will ultimately help biomedical engineers design other types of scaffolds and new drug delivery strategies to promote healing in other areas of the body, the researchers concluded in the paper published in the Journal of the Royal Society Interface.​

​Beijing, July 31 (IANS) A rare Chinese yew tree, believed to be about 3,000 years old, was discovered in Jilin province, authorities said on Sunday.

The living tree, located in Huanggou Forest, is more than 40 metres tall and has a diameter of 1.68 metres, Xinhua news agency quoted Yang Yongsheng, head of the forest administration, as saying.

The tree was among the more than 30 Chinese yew trees discovered earlier this week in the forest.

Called a "living fossil" of the plant world, the Chinese yew has existed for 2.5 million years.

Since many of the trees have been harvested to extract taxol, used to treat cancer, the species is now under first-grade national protection for endangered plants.​

Seoul, July 31 (IANS) A research team at the Korea Advanced Institute of Science and Technology (KAIST) has developed ultra-thin and transparent oxide thin-film transistors (TFT) that can be used to make high performance wearable and transparent displays.

With the advent of the "Internet of Things" era, strong demand has grown for wearable and transparent displays that can be applied to fields like augmented reality and skin-like thin flexible devices. But flexible transparent displays developed in earlier studies face challenges like poor transparency and low electrical performance. 

Led by Keon Jae Lee and Sang-Hee Ko Park from KAIST, researchers set out to overcome these challenges by using the inorganic-based laser lift-off (ILLO) method, according to the study published recently in the journal Advanced Materials. 

"By using our ILLO process, the technological barriers for high performance transparent flexible displays have been overcome at a relatively low cost by removing expensive polyimide substrates. Moreover, the high-quality oxide semiconductor can be easily transferred onto skin-like or any flexible substrate for wearable application," Lee said.

The team fabricated a high-performance oxide TFT array on top of a sacrificial laser-reactive substrate. After laser irradiation from the backside of the substrate, only the oxide TFT arrays were separated from the sacrificial substrate as a result of reaction between laser and laser-reactive layer, and then subsequently transferred onto ultrathin plastics. 

Finally, the transferred ultrathin-oxide driving circuit for the flexible display was attached conformally to the surface of human skin to demonstrate the possibility of the wearable application. The attached oxide TFTs showed high optical transparency of 83 per cent.

​London, July 31 (IANS) Cognitive ability like intelligence and verbal abilities, whether high or low, only predicts prejudice towards specific groups, according to a study.

"Very few people are immune to expressing prejudice, especially towards people they disagree with," said Mark Brandt, researcher, Tilburg University, the Netherlands, in the study published in Social Psychological and Personality Science.

The researchers analysed data from 5,914 people that includes a measure of verbal ability and prejudice towards 24 different groups.

Analysing the results, the researchers found that people with both relatively higher and lower levels of cognitive ability show approximately equal levels of intergroup bias but towards different sets of groups. 

People with low cognitive ability tended to express prejudice towards groups perceived as liberal and unconventional such as atheists, gays and lesbians.

People with high cognitive ability showed the reverse pattern. They tended to express prejudice towards groups perceived as conservative and conventional such as Christians, the military, big business, revealed the study.

"In our prior work we found that people high and low in the personality trait of openness to experience show very consistent links between seeing a group as 'different from us' and expressing prejudice towards that group. The same appears to be true for cognitive ability,” added Brandt.

According to the study, low cognitive ability express prejudice towards some target groups. For other target groups the relationship was in the opposite direction. For these groups, people with high levels of cognitive ability expressed more prejudice. ​

​New York, July 31 (IANS) Researchers have identified a genetic link between a rare heart rhythm disease and an increased risk for seizures proving a clear association between the heart and the brain of such patients.

Long QT syndrome (LQTS) is a rare heart rhythm condition that can potentially cause fast, chaotic heartbeats. These rapid heartbeats might trigger a sudden fainting spell or seizure.

The findings showed that patients carrying LQTS genetic mutations were three times more likely to have experienced seizures in their past, compared to their family members who did not carry those mutations.

Further, people with LQTS who experience seizures are at greater risk of sudden cardiac death.

“Seizure status is the strongest predictor of cardiac arrhythmias - the abnormal heart rhythms characteristic of LQTS,” said lead author David Auerbach from University of Rochester in New York, US.

In fact, about 20 per cent of the LQTS patients in the study who had a history of seizures had survived at least one lethal cardiac arrhythmia.

For the study, the team analysed of more than 18,000 people affected with LQTS as well as their affected and unaffected family members, who provide a nearly ideal group of controls.

"In essence, they have the same genetic makeup, except theoretically, the LQTS-causing mutation," Auerbach added.

Analysing patients' genetic information, the team found that among the three different types of LQTS (LQTS1-3) patients with LQTS1 and LQTS2 had much higher prevalence of seizures than LQTS3 or no mutation - with LQTS2 at the greatest risk.

Further investigation of the LQTS-causing mutation showed that the specific location of the mutation greatly affected the risk of cardiac arrhythmias and seizures.

In one location on the gene, the mutation protected against these symptoms, but in another location on the same gene, the mutation increased the risk of those symptoms.

Understanding what each of these mutations does may shed new light on a basic mechanism of seizures and may provide viable therapeutic targets to treat LQTS, the researchers cocnluded.

The results were published in the journal Neurology.​

New York, July 31 (IANS) Researchers have determined how a protein can boost immune system's ability to battle pneumonia.

The finding may offer a new way for doctors to boost patients' ability to fight off the life-threatening infection as bacteria become more and more resistant to antibiotics.

"We're interested in seeing if there are things we can do to strengthen the natural defences of the host to help them fight the infection more effectively," said Borna Mehrad from University of Virginia School of Medicine.

"Potentially this would be the sort of thing you could do in addition to antibiotics to help patients with severe infections," Mehrad noted.

Mehrad and his team determined that the lack of the cytokine M-CSF (short for macrophage-colony stimulating factor) in infected mice worsened the outcome of bacterial pneumonia.

Not having the protein resulted in 10 times more bacteria in the lungs, 1,000 times more bacteria in the blood and spread the infection to the liver, resulting in increased deaths.

Clearly M-CSF has an important role in battling pneumonia, but what exactly does it do?

"M-CSF has previously been shown to help make a type of immune cell, called monocytes, so my idea was that if you take it away, infected hosts just stop making monocytes and that's why they get sick, and it turned out that was completely wrong," Mehrad said.

Instead, the findings published in The Journal of Immunology showed that M-CSF helped monocytes survive once they have arrived in the infected tissues.

"If you take M-CSF away, the infections get worse, so that raises two important questions about therapy: Would more be better? It may be that during infection, the body is making the right amount of M-CSF and if we add extra, it won't improve outcomes further," Mehrad said.

"The second possibility is that there is room for improvement: in the fight between monocytes and the bacteria, M-CSF may make monocytes live longer and give them an edge. In addition, some people with weakened immunity might not make enough of M-CSF. If that's the case, you could augment that and improve their ability to fight the infection," Mehrad explained.​

​New York, July 29 (IANS) Scientists have developed a sustainable, wearable bio-sensor to detect conditions like muscle fatigue, stress and dehydration by taking advantage of trove of medical information present in human sweat.

"When the human body undergoes strenuous exercise, there's a point at which aerobic muscle function becomes anaerobic muscle function," said study co-author Jenny Ulyanova from CFD Research Corporation (CFDRC). 

"At that point, lactate is produce at a faster rate than it is being consumed. When that happens, knowing what those levels are can be an indicator of potentially problematic conditions like muscle fatigue, stress, and dehydration," he added.

What separates this study from other researches is the use of purely biological green technology. 

The team, in collaboration with University of New Mexico, developed an enzyme-based sensor powered by a biofuel cell -- providing a safe, renewable power source. 

"The biofuel cell works in this particular case because the sensor is a low-power device," Ulyanova said. 

"They're very good at having high energy densities, but power densities are still a work in progress. But for low-power applications like this particular sensor, it works very well," he added in a paper published in the ECS Journal of Solid State Science and Technology.

The team powered the biofuel cells with a fuel based on glucose. This same enzymatic technology, where the enzymes oxidise the fuel and generate energy, is used at the working electrode of the sensor which allows for the detection of lactate in human sweat.

Another novel aspect of this work is the use of electrochemical processes to very accurately detect a specific compound in a very complex medium like sweat.

"We're doing it electrochemically, so we're looking at applying a constant load to the sensor and generating a current response," Ulyanova said, "which is directly proportional to the concentration of our target analyte".

Although the sensor was designed for a soldier in training, it could also be applied to people that are active and anyone participating in strenuous activity.

As for commercial applications, the researchers believe the device could be used as a training aid to monitor lactate changes in the same way that athletes use heart rate monitors to see how their heart rate changes during exercise.​

New York, July 29 (IANS) Researchers have developed a potentially game-changing solar cell that essentially does the work of plants -- converting atmospheric carbon dioxide into usable hydrocarbon fuel using only sunlight for energy.

"The new solar cell is not photovoltaic - it's photosynthetic," said senior study author Amin Salehi-Khojin from the University of Illinois at Chicago. 

"Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight," he added.

While plants produce fuel in the form of sugar, the artificial leaf delivers syngas, or synthesis gas, a mixture of hydrogen gas and carbon monoxide. Syngas can be burned directly, or converted into diesel or other hydrocarbon fuels.

The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete.

Chemical reactions that convert CO2 into burnable forms of carbon are called reduction reactions, the opposite of oxidation or combustion. 

Engineers have been exploring different catalysts to drive CO2 reduction, but so far such reactions have been inefficient and rely on expensive precious metals such as silver, Salehi-Khojin said.

"What we needed was a new family of chemicals with extraordinary properties," he added in a paper published in the journal Science.

The team focused on a family of nano-structured compounds called transition metal dichalcogenides -- or TMDCs -- as catalysts, pairing them with an unconventional ionic liquid as the electrolyte inside a two-compartment, three-electrode electrochemical cell.

The best of several catalysts they studied turned out to be nanoflake tungsten diselenide.

"The new catalyst is more active; more able to break carbon dioxide's chemical bonds," said study lead author Mohammad Asadi. 

In fact, the new catalyst is 1,000 times faster than noble-metal catalysts and about 20 times cheaper.

The technology should be adaptable not only to large-scale use, like solar farms, but also to small-scale applications, Salehi-Khojin said. 

It may prove useful on Mars, whose atmosphere is mostly carbon dioxide, if the planet is also found to have water.

New York, July 30 (IANS) Researchers have developed a portable production system that can manufacture a range of bio-pharmaceuticals on demand to help doctors treat patients in remote or developing parts of the world like India, where getting rapid access to drugs can be challenging.

Bio-pharmaceutical drugs are used in a wide range of therapies including vaccines and treatments for diabetes and cancer. But these are typically produced in large, centralised fermentation plants and transporting them to the treatment site can be expensive and time-consuming.

The new system, developed by researchers at the Massachusetts Institute of Technology, can be used to produce a single dose of treatment from a compact device containing a small droplet of cells in a liquid. 

It was recently described in the journal Nature Communications.

"Imagine you were on Mars or in a remote desert, without access to a full formulary, you could program the yeast to produce drugs on demand locally," said senior study author Tim Lu.

The system could be carried onto the battlefield and used to produce treatments at the point of care. It may also be used to manufacture a vaccine to prevent a disease outbreak in a remote village.