We all know what happens when cars collide on the freeway or an anvil lands on Wile E. Coyote's head - physics at the macro level is predictable. But what about a single hydrogen atom and a lone molecule of deuterium, the smallest atom and one of the smallest molecules?

When an atom collides with a molecule, traditional wisdom said the atom had to strike one end of the molecule hard to deliver energy to it. People thought a glancing blow from an atom would be useless in terms of energy transfer, but that turns out not to be the case, according to the researchers.

Every atom or molecule, even if it has no charge, has electrostatic forces around it-sort of like the magnetic field of the Earth. Those chemical forces exert a pull on any other atom or molecule within range, trying to form a chemical bond.

More evidence for the beneficial effect of green tea on risk factors for heart disease has emerged in a new study reported in the latest issue of European Journal of Cardiovascular Prevention and Rehabilitation.(1) The study found that the consumption of green tea rapidly improves the function of (endothelial) cells lining the circulatory system; endothelial dysfunction is a key event in the progression of atherosclerosis.

The study, performed by Dr Nikolaos Alexopoulos and colleagues at the 1st Cardiology Department, Athens Medical School in Greece, was a randomised trial involving the diameter measurement (dilatation) of the brachial artery of healthy volunteers on three separate occasions - after taking green tea, caffeine, and hot water (for a placebo effect). The measurements were taken at 30, 90 and 120 minutes after consumption. Dilatation of the brachial artery as a result of increased blood flow (following a brief period of ischaemia of the upper limb) is related to endothelial function and is known to be an independent predictor of cardiovascular risk.(2)

Do men who have more sex get less erectile disfunction(ED) or are studies skewed because men with erectile disfunction report having less sex? It's hard to say but the message is clear; have more sex.

Having intercourse more often may also help prevent the development of erectile dysfunction. A study in The American Journal of Medicine reports that researchers have found that men who had intercourse more often were less likely to develop ED.

Analyzing a five-year study of 989 men aged 55 to 75 years from Pirkanmaa, Finland, the investigators observed that men reporting intercourse less than once per week at baseline had twice the incidence of erectile dysfunction compared with those reporting intercourse once per week. Further, the risk of erectile dysfunction was inversely related to the frequency of intercourse.

Scientists from Hungary, Germany and the U.K. have discovered that our own body not only makes chemical compounds similar to the active ingredient in marijuana (THC), but these play an important part in maintaining healthy skin.

This finding on "endocannabinoids" just published in The FASEB Journal could lead to new drugs that treat skin conditions ranging from acne to dry skin, and even skin-related tumors.

"Our preclinical data encourage one to explore whether endocannabinoid system-acting agents can be exploited in the management of common skin disorders," said Tamás Biró, MD, PhD, a senior scientist involved in the research. "It is also suggested that these agents can be efficiently applied locally to the skin in the form of a cream."

Women over 90 are significantly more likely to have dementia than men of the same age, according UC Irvine researchers involved with the 90+ Study, one of the nation's largest studies of dementia and other health factors in the fastest-growing age demographic.

The researchers reviewed an analysis of 911 people enrolled in the 90+ Study. Of those, 45 percent of the women had dementia, as opposed to 28 percent of the men. The analysis did not determine when the subjects first experienced dementia.

The 90-plus age group, or the "oldest old," is the fastest growing segment of the population, according to the U.S. Census. While there are currently nearly 2 million nonagenarians in the U.S. alone, that number is projected to increase to 10 to 12 million by the middle of the century, raising concerns that the current health care system may not be able to accommodate this population.

A University of Chicago expedition at Tell Edfu in southern Egypt has unearthed a large administration building and silos that provide insight into ancient Egyptian urban life and a little understood aspect of ancient Egypt; the development of cities in a culture that is largely famous for its monumental architecture.

The archaeological work at Tel Edfu was initiated with the permission of the Supreme Council of Antiquities, headed by Zahi Hawass, under the direction of Nadine Moeller, Assistant Professor at the Oriental Institute, University of Chicago. Work late last year revealed details of seven silos, the largest grain bins found in ancient Egypt as well as an older columned hall that was an administration center.