Some Science

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Comment by Dr. Krishna Kumari Challa 13 hours ago

Bio-degradable plastic from rice starch:

Researchers in Finland have transformed rice starch into a temporally stable, optically transpa... with a high degree of mechanical strength and good thermal resistance. This important step towards bioplastics made from simple and sustainable resources has potential applications in food packaging and biomedical materials.

http://pubs.rsc.org/en/Content/ArticleLanding/2014/GC/c4gc00794h#!divAbstract

Comment by Dr. Krishna Kumari Challa yesterday

Two men who were HIV-positive appear to have cleared the virus, registering undetectable levels after bone marrow transplants in Sydney. The research was presented at the Towards an HIV Cure Symposium, which is part of the 20th International AIDS Conference in Melbourne.
https://newsroom.unsw.edu.au/sites/default/files/documents/Abstract...

Comment by Dr. Krishna Kumari Challa yesterday

Scientists have developed nanomaterials capable of simultaneous photodynamic therapy and photothermal therapy to treat tumors. When illuminated under specific wavelengths, these nanomaterials are able to produce reactive oxygen species and heat at the same time, killing tumor cells. This research has been published in the journal Advanced Materials.
http://onlinelibrary.wiley.com/enhanced/doi/10.1002/adma.201400703/
Gold nanoechinus can sensitize formation of singlet oxygen in the first and the second near-infra red (NIR) biological windows and exert in vivo dual modal photodynamic (PDT) and photothermal therapeutic effects (PDT) to destruct the tumors completely. This is the first literature example of the dual modal nanomaterial-mediated photodynamic and photothermal therapy (NmPDT & NmPTT) induced destruction of tumors in NIR window II.

Comment by Dr. Krishna Kumari Challa yesterday

New blood test could detect cancer early

British scientists claim they’ve developed a simple blood test that could detect cancer and prompt early, life-saving measures.

The tests are aimed at analyzing white blood cell which are “under stress” when there’s cancer or precancerous growth in the body, researchers wrote in the journal of the Federation of American Societies for Experimental Biology.

“We know that they are under stress when they are fighting cancer or other diseases, so I wondered whether anything measurable could be seen if we put them under further stress with UVA light,” according to lead researcher Diana Anderson, from the University of Bradford’s School of Life Sciences.

“We found that people with cancer have DNA which is more easily damaged by ultraviolet light than other people.”

The Lymphocyte Genome Sensitivity (LGS) tests looked at blood samples from 208 people — including healthy university staff and students and patients at the Bradford Royal Infirmary.

UVA light was shined on all blood samples, and DNA damage perfectly correlated to conditions of each subject, according to researchers.

The 58 subjects with the most damaged DNA samples turned out to be cancer patients, while 56 with precancerous conditions showed moderate DNA damage, researchers said.

The 94 cancer-free samples similarly showed minimal DNA damage after being exposed to UVA light, according to findings.

Comment by Dr. Krishna Kumari Challa yesterday

In Australia, money for science is cut, money for religious programs increased
http://doubtfulnews.com/2014/07/in-australia-money-for-science-is-c...

Comment by Dr. Krishna Kumari Challa yesterday

Observation of a quantum Cheshire Cat in a matter-wave interferometer experiment

Abstract:

From its very beginning, quantum theory has been revealing extraordinary and counter-intuitive phenomena, such as wave-particle duality, Schrödinger cats and quantum non-locality. Another paradoxical phenomenon found within the framework of quantum mechanics is the ‘quantum Cheshire Cat’: if a quantum system is subject to a certain pre- and postselection, it can behave as if a particle and its property are spatially separated. It has been suggested to employ weak measurements in order to explore the Cheshire Cat’s nature. Here  scientists report an experiment in which they send neutrons through a perfect ​silicon crystal interferometer and perform weak measurements to probe the location of the particle and its magnetic moment. The experimental results suggest that the system behaves as if the neutrons go through one beam path, while their magnetic moment travels along the other.

http://www.nature.com/ncomms/2014/140729/ncomms5492/full/ncomms5492...

The phenomenon is named after the curious feline in Alice in Wonderland, who vanishes leaving only its grin.

Researchers took a beam of neutrons and separated them from their magnetic moment, like passengers and their baggage at airport security.

The same separation trick could in principle be performed with any property of any quantum object, say researchers from Vienna University of Technology.

Their technique could have a useful application in metrology - helping to filter out disturbances during high-precision measurements of quantum systems.

Comment by Dr. Krishna Kumari Challa on Tuesday

Depleted Uranium Could Turn Carbon Dioxide into Valuable Chemicals
New reactions could convert excessive CO2 into building blocks for materials like nylon
European scientists have synthesised uranium complexes that take them a step closer to producing commodity chemicals from carbon dioxide.
http://www.rsc.org/chemistryworld/2014/07/uranium-carbon-dioxide-ox...

Comment by Dr. Krishna Kumari Challa on Sunday

Comment by Dr. Krishna Kumari Challa on Saturday

Swimmers have to be careful about not only the infections they get from bacteria and virus but also harm caused by brain eating amoeba  Naegleria fowleri that dwells in dwells in warm freshwater lakes and rivers and usually targets children and young adults. Once in the brain it causes a swelling called primary meningoencephalitis. The infection is almost universally fatal.

The amoeba has strategies to evade the immune system, and treatment options are meager partly because of how fast the infection progresses.

But research suggests that the infection can be stopped if it is caught soon enough. So what happens during an N. fowleri infection?

The microscopic amoebae, which can be suspended in water or nestled in soil, enter the body when water goes up the nose. After attaching to the mucous membranes in the nasal cavity, N. fowleri burrows into the olfactory nerve, the structure that enables our sense of smell and leads directly to the brain. It probably takes more than a drop of liquid to trigger a Naegleria infection; infections usually occur in people who have been engaging in water sports or other activities that may forcefully suffuse the nose with lots of water—diving, waterskiing, wakeboarding, and in one case a baptism dunking.

It turns out that "brain eating" is actually a pretty accurate description for what the amoeba does. After reaching the olfactory bulbs, N. fowleri feasts on the tissue there using suction-cup-like structures on its surface. This destruction leads to the first symptoms—loss of smell and taste—about five days after the infection sets in.

From there the organisms move to the rest of the brain, first gobbling up the protective covering that surrounds the central nervous system. When the body notices that something is wrong, it sends immune cells to combat the infection, causing the surrounding area to become inflamed. It is this inflammation, rather than the loss of brain tissue, that contributes most to the early symptoms of headache, nausea, vomiting and stiff neck. Neck stiffness in particular is attributable to the inflammation, as the swelling around the spinal cord makes it impossible to flex the muscles.

As N. fowleri consumes more tissue and penetrates deeper into the brain, the secondary symptoms set in. They include delirium, hallucinations, confusion and seizures. The frontal lobes of the brain, which are associated with planning and emotional control, tend to be affected most because of the path the olfactory nerve takes. But after that there’s kind of no rhyme or reason—all of the brain can be affected as the infection progresses.

Ultimately what causes death is not the loss of grey matter but the extreme pressure in the skull from the inflammation and swelling related to the body’s fight against the infection. Increasing pressure forces the brain down into where the brain stem meets the spinal cord, eventually severing the connection between the two. Most patients die from the resulting respiratory failure less than two weeks after symptoms begin.

- SA

Comment by Dr. Krishna Kumari Challa on July 25, 2014 at 11:02am

Carbs and gut microbes fuel colon cancer
Sugar-loving bacteria support the emergence of tumors in mice
http://www.cell.com/cell/abstract/S0092-8674%2814%2900736-3

Gut Microbial Metabolism Drives Transformation of Msh2-Deficient Colon Epithelial Cells
The etiology of colorectal cancer (CRC) has been linked to deficiencies in mismatch repair and adenomatous polyposis coli (APC) proteins, diet, inflammatory processes, and gut microbiota. However, the mechanism through which the microbiota synergizes with these etiologic factors to promote CRC is not clear. We report that altering the microbiota composition reduces CRC in APCMin/+MSH2−/− mice, and that a diet reduced in carbohydrates phenocopies this effect. Gut microbes did not induce CRC in these mice through an inflammatory response or the production of DNA mutagens but rather by providing carbohydrate-derived metabolites such as butyrate that fuel hyperproliferation of MSH2−/− colon epithelial cells. Further, we provide evidence that the mismatch repair pathway has a role in regulating β-catenin activity and modulating the differentiation of transit-amplifying cells in the colon. These data thereby provide an explanation for the interaction between microbiota, diet, and mismatch repair deficiency in CRC induction.

•Gut microbiota induce colon cancer in genetically sensitized MSH2-deficient mice
•Reduced dietary carbohydrates decreased polyp frequency in APCMin/+MSH2−/− mice
•The carbohydrate metabolite butyrate induces colon cancer in APCMin/+MSH2−/− mice
•MSH2 regulates β-catenin activity and/or transit-amplifying cell differentiation

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