For Science: April 2014

Wednesday, April 30, 2014

Lithum batteries to be replaced?

Researchers at Rice University developed a thin and flexible film made out of nanoporous nickel-fluoride electrodes that, according to its creators, combines the best qualities of batteries and supercapacitators. The film, called electrochemical capacitator, packs high electrical storage capacity even if it is only one-hundredth of an inch thick.

This technology could be scaled to all types of devices and its capacity can be increased by adding layers or increasing its size. It represents a step forward in the search for parts that can be used in flexible, wearable devices.

According to a news release the flexible device held 76 percent of its capacity over 10,000 charge-discharge cycles and 1,000 bending cycles.

“Compared with a lithium-ion device, the structure is quite simple and safe,” said postdoctoral researchers Yang Yang in the news release. “It behaves like a battery but the structure is that of a supercapacitor. If we use it as a supercapacitor, we can charge quickly at a high current rate and discharge it in a very short time. But for other applications, we find we can set it up to charge more slowly and to discharge slowly like a battery.”

Y chromosome linked to cancer

Though overall life expectancy varies around the globe, it is true for pretty much any country you look at that females live longer than males. There are many factors assumed to play into this, such as a later onset of cardiovascular disease for females compared to males, but a new study from a team of researchers led by Jan Dumanski of Uppsala University has found a correlation between loss of the Y chromosome and early death, in addition to an increased risk of cancer. Their findings were published in Nature Genetics.

As a person ages, the genome alters slightly through random mutations over a lifetime of DNA replication for cell division. This natural process has been attributed to an increase in risk for diseases like cancer or diabetes later in life, but not much was known about the causal mechanism. Dumanski’s team sought to find if there were any common trends about which parts of the genome were changing. Blood samples were taken from over 1,600 elderly men and their health was tracked until their deaths.

The most common place to identify the age-related loss of the Y chromosome (LOY) was in the white blood cells, which play a role in tumor suppression. One cohort found that about 8.2% of the men with non-hematological cancer had LOY, and those individuals lived an average of 5.5 shorter than those with the Y chromosome in tact. An independent cohort found that about one in five men had LOY and died earlier, regardless of the cause.

"Men who had lost the Y chromosome in a large proportion of their blood cells had a lower survival, irrespective of cause of death,” said Lars Forsberg, lead author on the study, in a press release. “We could also detect a correlation between loss of the Y chromosome and risk of cancer mortality."

The researchers note that this indicator could be used as a biomarker for physicians to use in explaining the risk carcinogenesis to their patients. This may also indicate that the Y chromosome, which contains the SRY gene responsible for sex determination, may also have other functions that are not currently well-understood.

“You have probably heard before that the Y chromosome is small, insignificant and contains very little genetic information. This is not true,” Dumanski explained in the press release. “Our results indicate that the Y chromosome has a role in tumor suppression and they might explain why men get cancer more often than women.”

Probable HIV cure found

Whilst screening the National Cancer Institute’s extract repository, scientists discovered a new class of proteins from a feathery coral found in Australian waters. It transpires that these proteins, called cnidarins, are in fact potent inhibitors of HIV entry into T-cells in laboratory tests.At a time when over 35 million people worldwide are infected with HIV and current treatments are not curative, focusing on the prevention of new infections is paramount in confronting this global problem. HIV has also presented significant challenges in the development of vaccines and none are so far available.Right now there are not too many methods that can prevent HIV transmission and scientist believe cnidarins may be used to do just that.

After a recent discovery finding HIV viruses are actually adopting to humans, (http://www.thehealthsite.com/news/deadly-hiv-adapting-to-humans

https://uk.news.yahoo.com/hiv-mutating-adapt-humans-warn-scientists-112636786.html)

scientists are racing against time to make a cure.

After discovering these proteins, scientists purified them and tested them for inhibitory effects against laboratory HIV strains. They found that they prevented HIV from being able to enter T-cells at impressively low concentrations. T-cells are one of the main cells that HIV targets for replication. The proteins achieved this block by binding to the virus and preventing fusion with the host cell, which is a pre-requisite to viral entry.

Before the scientists can proceed with preclinical tests to find out more about the safety and efficacy of these proteins, they first need to find a way to mass produce these proteins without having to harvest vast quantities of corals.

Although it is certainly very early days, the scientists are optimistic that these proteins may present an ideal candidate for the development of topical gels or lubricants that could prevent sexual HIV transmission without encouraging resistance, which is a problem that current antivirals face.

This study also serves as an exciting reminder for the fact that many natural substances with surprising medicinal properties may await discovery. “The natural products extract repository is a national treasure,” said Barry O’Keefe, senior investigator of this study. “You never know what you might find. Hopefully, discoveries like this will encourage more investigators to use this resource to identify extracts with activity against infectious disease.”

cheap microscope

Clear liquid droplets can bend light, acting like a lens. By exploiting this well-known phenomenon, scientists have devised a cheap and simple way to turn a smartphone into a high-resolution microscope. The high-powered lenses cost less than a cent apiece to make, and all you need is a cover slip or glass slide, some common polymer, and an oven. The method would be immensely helpful for diagnosing medical conditions in remote areas and developing countries.

Conventional lenses are usually made in one of two ways. You can grind and polish a flat disk of glass into a particular curved shape, or you can pour gel into molds. These new lentil-sized lenses simply retain the natural shape of liquid droplets. They're made of a gel-like silicon polymer called polydimethylsiloxane (PDMS) -- the same unbreakable, scratch-free stuff used for contact lenses.

TO make your own microscope at home -

1. Drop a small amount of PDMS onto the slide.

2. Bake at 70 degrees Celsius to harden it and create a base.

3. Afterwards, drop another dollop of PDMS onto the base and flip the slide over.

4. Watch as gravity pulls the new droplet down into a parabolic shape.

5. Bake the droplet again to solidify the lens.

6. Add more drops as needed to hone the lens shape and enhance the imaging quality of the lens.

The whole lens was only a few millimeters thick and just over a centimeter in diameter. The team then designed a lightweight 3D-printable frame to hold the lens, along with a couple mini LEDs and a coin battery for watches. The attachment turns a smartphone camera into a dermascope to diagnose skin diseases like melanoma. Dermascopes can cost $500; this new prototype dermascope add-on comes to about $2. You can check out this comparison of the magnified images.