 |
|
|
See How Oil Mixes With Water
(Go To Top)
WASHINGTON: Have you ever seen oil mixing with water? Well, it sounds strange but this could now be possible, claims a new study. If confirmed, the findings published in New Scientist could provide evidence to one of chemistry's most puzzling phenomena. This is the so-called long-range hydrophobic force, which causes oil surfaces to attract one another. According to chemist Ric Pashley of the Australian National University in Canberra, if you first remove any gas that is dissolved in the water, it will mix spontaneously and even stay that way indefinitely. "Many scientists are going to find this very hard to believe," says colloid scientist Len Fisher of the University of Bristol in England, "but Pashley has provided very strong proof that oil and water will mix." Pashley's observation is, however, bound to cause controversy as the reason why it happens is still unclear. Chemists are waiting to see whether the experiment can be repeated. For the study, the researcher removed almost all the gas from a water-oil mixture by repeatedly freezing and thawing it while pumping off the gases as they evaporated out. The results were astonishing. "The mix spontaneously formed a cloudy emulsion. I was as surprised as anybody," says Pashley. The result suggests that dissolved gas may be involved in how the force acts. "He takes the air out and he doesn't get the long-range hydrophobic force. It doesn't nail the hydrophobic force down, but now we have something to work on," says James Quirk, a chemist at the University of Western Australia in Perth, who hopes that studying the spontaneous emulsions may lead to an explanation for the elusive force. Even more surprisingly, the mixture did not break up even when gas was put back into the water after the emulsion had formed. Pashley suggests that the gas might interfere with the hydrophobic force most effectively only when the oil droplets are extremely close together, such as when they are first separating as the emulsion starts to form. Once the emulsion has formed, hydroxyl groups from the water adsorb onto the surface of the oil droplets, making them similarly charged and thus preventing them from coming close together. The study suggests that if spontaneous emulsions can be made at will, the new findings could have important applications in medicine and the chemical industry. Combination HRT Increases Stroke
Risk in Women (Go To Top)
WASHINGTON: Combined hormone replacement therapy (HRT) increased the risk of stroke for post-menopausal women of all ages, whether or not they had hypertension, according to reports presented at the American Stroke Association's 28th International Stroke Conference. "Estrogen plus progestin increased the risk of stroke in older and younger post-menopausal women, in those with and without high blood pressure and in those with no prior history of cardiovascular disease (CVD). Our finding is that this is absolutely not a strategy for primary prevention of cardiovascular disease," says Sylvia Wassertheil-Smoller, Ph.D., professor of epidemiology and social medicine and head of the division of epidemiology and biostatistics at Albert Einstein College of Medicine in New York. Smoller is a principal investigator of a Women's Health Initiative (WHI), a multi-part study that enrolled more than 160,000 post-menopausal women at 40 US medical centres between 1993 and 1998. Drug to Arouse Women Sexually
in the Making(Go To Top)
SYDNEY: In a significant breakthrough, a British expert claims to have found a way to produce sex-enhancing drug for women. Unlike the male impotency pill Viagra, which acts on the sexual organs, the drug in the most recent study stimulates the brain, according to a report in Sydney Morning Herald. Ian Russell, a specialist nurse at Dumfries and Galloway NHS Trust, is encouraged by the results of tests carried out on 10 women during an 18-week study. The women, who suffered from lack of sexual desire, were treated with a drug called apomorphine. "The results were astonishing", Russell told BBC. Eight of the 10 women reported a heightened sexual desire at the end of 18 weeks using the drug, which mimics the effect of one of the brain's main chemical messengers, dopamine, the report said. Since its launch in 1998, scientists have been investigating whether Viagra, which has been used by more than 20 million men world-wide, could work for women too. Ian Russell's apomorphine trials could offer hope to women everywhere who suffer from reduced sexual desire. But despite the encouraging initial results, scientists remain cautious about Russell's findings, the report added. Russell agrees more research is needed and has begun a much larger clinical trial, which should be completed next year. Vaginal Gel Can Prevent HIV
Infection (Go To Top)
WASHINGTON: A simple vaginal gel shows promise to help stop the spread of HIV. Researchers say that a squirt of antibody, called b12, could control sexual transmission of HIV, thus saving lives of women in developing countries who may be unable to protect themselves by monogamy or using condoms.
"We're encouraged," says lead researcher John Moore of Cornell University
in New York. Moore's team used the antibody, which prevents the virus
burying into human cells, that binds an HIV coat protein and stops it
latching on to cells, says a report in Nature. Applied two hours before
sex, to the vagina or rectum, the human antibody prevented nine out
of 12 monkeys from getting infected with a version of HIV; 12 out of
13 monkeys were infected without the antibody. This problem is partly fuelling the runaway AIDS epidemic, which currently affects an estimated 42 million people world-wide. Unlike some other microbicides, which may also affect healthy cells, the antibody specifically targets HIV. A Dose of Stem Cells Strengthens
Injured Heart (Go To Top)
LONDON: An experimental use of stem cells to strengthen heart cells has proved successful, with researchers giving first direct proof that stem cells injected into an injured heart do develop to take on some of the work load. Muscle stem cells, called myoblasts, were taken from the thigh muscle of a man who had suffered a heart attack, cultured, and then injected into his heart. The function of the 72-year-old man's heart was stronger after the treatment. But it was only when he died 18 months later that researchers could prove that the injected myoblasts had metamorphosed, says a report in New Scientist. "This is the first demonstration of the concept in humans, and confirms animal findings," Albert Haghge at the Hospital Europien Georges Pompidou, Paris, France, was quoted as saying in the report. The key to showing that the myoblasts had developed into cells useful to the heart was a major muscle protein called myosin, which exists in two forms. The "fast" form is used mainly in skeletal muscle, while the "slow" form is expressed mainly in heart muscle. The injected cells still "looked like typical skeletal muscle fibres, but there was a lot of slow myosin in these fibres," Haghge told New Scientist. Normally cells only produce one form of myosin. According to Haghge, the environment of the heart is likely to have caused the changes in the myoblast's function. The man whose cardiac tissue transformed the muscle cells was participating in a study by Haghge and colleagues to examine the safety of the procedure. The findings, on 10 patients who had suffered heart attacks, show useful improvements in heart function. Cellphones Threaten Patients'
Lives in Hospitals (Go To Top)
WASHINGTON: Carrying cellphones to hospitals could be dangerous, as a new Harvard study now claims that the electromagnetic energy emitted by these equipments can interfere with mechanical ventilators found in intensive care units (ICU) and, if strong enough, can even shut down a machine. The team, led by biomedical engineer Cheryl Iden Shaw, conducted a study on the effects of cellular phones on 20 different medical devices. The machines tested included mechanical ventilators, which help patients breathe, and defibrillators, which are used to shock the heart back into its normal rhythm. The experts said that though visitors may not be able to get so dangerously close to the life-giving machines, the doctors and nurses themselves often keep their cellphones on in their pocket or on their hip, which could shut down a ventilator while they are standing close to it, attending to a patient. Vaccine From Chimp Virus
a Potential HIV Fighter (Go
To Top) WASHINGTON: A new study has found that a new vaccine, a modified form of a chimpanzee virus, shows promise against HIV, according to researchers. The virus could prove to be a major breakthrough against the disease. The study in mice, led by researchers at the Wistar Institute, has been published in the current issue of Immunology. "Our results show this new vaccine is capable of inducing the kind of powerful immune response that we and others believe will be critical for controlling HIV infection," says Hildegund CJ Ertl, MD, professor and immunology programme leader at the Wistar Institute, and senior author on the new study. Given the history of HIV, Ertl emphasize the lengths to which she and her colleagues have gone to ensure that the new vaccine is completely safe. To eliminate the possibility of any contaminant - an HIV-like stowaway, for example - the vaccine is derived in the laboratory from a set of genetic instructions. Importantly, too, the genes that would be needed by the viral vaccine to replicate are deleted from those instructions. The vaccine is based on chimpanzee adenovirus. In chimpanzees and humans, adenoviruses are a common cause of respiratory-tract diseases. Viagra's Rival Claims Quicker
Effect (Go To Top)
LONDON: : To enhance men's sexuality, a new sex drug, called Cialis, which claims better sexual stamina and prolonged arousal than existing drugs, has now been launched. According to its developers, the effect lasts 24 hours. More interestingly, some patients who tested it stayed aroused for 36 hours, reports the Sun. They also say that where Viagra can take over an hour to work and usually allow users to manage sex only once, the new drug gets men ready straight away. Dr Richard Petty, an impotence specialist at the London Wellman Clinic, said: "My patients are over the moon about a pill that lasts so long. The main complaint about Viagra has been the lack of spontaneity." Give Vent to Anger and Lessen
Chances of Heart Attack (Go To Top)
WASHINGTON: Expressing anger outwardly can at times help reduce risk of stroke and heart disease in men. The study, published in the journal of Psychosomatic Medicine, found that men with moderate levels of anger expression had nearly half the risk of non-fatal heart attacks and a significant reduction in the risk of stroke compared to men with low levels of anger expression. In the case of stroke, the researchers found that the risk decreased in proportion to increasing levels of anger expression, reports Health Behaviour News Service. The findings indicate "a more complex pattern of associations between anger and cardiovascular disease than previously described," according to Patricia Eng, Sc.D., of the Harvard School of Public Health, and colleagues. -ANI |
|