Many of the greatest inventions in modern medicine were developed by physicists who imported technologies such as X rays, nuclear magnetic resonance, ultrasound, particle accelerators and radioisotope tagging and detection techniques into the medical domain.

There they became magnetic resonance imaging (MRI), computerized tomography (CT) scanning, nuclear medicine, positron emission tomography (PET) scanning, and various radiotherapy treatment methods. These contributions have revolutionized medical techniques for imaging the human body and treating disease.

In 2008, the American Association of Physicists in Medicine (AAPM), is celebrating its 50th anniversary and is calling attention to the field of medical physics achievements.

The best way to do that? Make a top 5 list and publish it here.

Scientists have long known that most compounds in living things exist in mirror-image forms. The two forms are like hands; one is a mirror reflection of the other. They are different, cannot be superimposed, yet identical in their parts.

When scientists synthesize these molecules in the laboratory, half of a sample turns out to be “left-handed” and the other half “right-handed.” But amino acids, which are the building blocks of terrestrial proteins, are all “left-handed,” while the sugars of DNA and RNA are “right-handed.” The mystery as to why this is the case, “parallels in many of its queries those that surround the origin of life,” says Sandra Pizzarello, a research professor at Arizona State University.

An important discovery has been made with respect to the mystery of this “handedness” in biomolecules. Some of the possible abiotic precursors to the origin of life on Earth have been shown to carry “handedness” in a larger number than previously thought.

It has been a mystery why unusually severe epidemics of influenza occur from time to time, such as in 1947 and 1951, when illness and mortality rates exceeded standard epidemic levels.

The standard model of human influenza virus evolution holds that major influenza pandemics, the largest of which occurred in 1918, are caused by reassortment between human and avian influenza viruses. But seasonal influenza epidemics, which occur each winter in the United States, do not involve the reassortment of genetic material.

Researchers at Pennsylvania State University and the National Institute of Health used an evolutionary analysis of influenza viruses sampled from 1918 – 2005 to investigate the influenza viruses that cause seasonal epidemics in humans, particularly those where mortality was unusually high.

The distinctive ability of mothers to identify the cries of their offspring is widely evident in nature, where it is critical to the survival of these offspring. In humans, we are aware that the distinctive ability of mothers to recognize and respond to the smiles and cries of their babies plays an important role in the psychological, cognitive, and social development of these babies.

We have had a very limited understanding of how the maternal brain accomplishes these amazing feats, but a new study published in Biological Psychiatry now provides some new insight.

Noriuchi, Kikuchi, et al. used functional magnetic resonance imaging (fMRI), a tool that enables scientists to study the function of brain circuits in people, to examine patterns of maternal brain activation.

While its known that cigarette smoking can cause cancer it has been unclear how cigarette smoke causes healthy lung cells to become cancerous.

Researchers from U.C. - Davis say that hydrogen peroxide (or similar oxidants) in cigarette smoke is the culprit. This finding may help the tobacco industry develop “safer” cigarettes by eliminating such substances in the smoke, while giving medical researchers a new avenue to developing lung cancer treatments.

“With the five-year survival rate for people with lung cancer at a dismally low 15.5 percent, we hope this study will provide better insight into the identification of new therapeutic targets,” said Tzipora Goldkorn, senior author of the report.

A highly specialised computer modelling technique developed at The University of Nottingham has been instrumental in the design of a revolutionary new swimsuit which is now being hailed as the fastest in the world.

Dr Herve Morvan, a lecturer in fluid mechanics in the School of Mechanical, Materials and Manufacturing Engineering, is working as an advisor to the AQUALAB, Speedo’s competition research and development department, responsible for the development of Speedo’s new LZR Racer swimsuit.

Within a week of its launch athletes wearing the new swimsuit had broken three world records.

Differences in gene expression levels between people of European versus African ancestry can affect how each group responds to certain drugs or fights off specific infections, say researchers in the American Journal of Human Genetics.

They used Affymetrix exon arrays to show that expression levels for nearly five percent of the 9,156 human genes they studied varied significantly between individuals of European and African ancestry. The research team took an unbiased whole genome approach and found significant differences in several unrelated processes, especially among genes involved in producing antibodies to potential microbial invaders.

A report in a recent New England Journal of Medicine, led by researchers at the New England Newborn Screening Program (NENSP) of the University of Massachusetts Medical School (UMMS), indicates a declining incidence of a genetic disease, providing what may be the first demonstration of a link between two independent population-based screening programs.

The state of Massachusetts has offered universal newborn screening to detect cystic fibrosis (CF) since 1999. Independently, recommendations for nationwide (adult) carrier screening for CF were introduced in the U.S. around 2002, coming from the National Institutes of Health, the American College of Obstetrics and Gynecology and the American College of Medical Genetics.

Scientists at the John Innes Centre in Norwich have discovered how roots find their way past obstacles to grow through soil. The discovery also explains how germinating seedlings penetrate the soil without pushing themselves out as they burrow.

“The key is in the fuzzy coat of hairs on the roots of plants” says Professor Liam Dolan. “We have identified a growth control mechanism that enables these hairs to find their way and to elongate when their path is clear”.

Root hairs explore the soil in much the same way as a person would feel their way in the dark. If they come across an obstacle, they feel their way around until they can continue growing in an opening.

In the 1980s and 90s, Scotland was known for its alarmingly high suicide rate. But since 2000, suicide rates have fallen sharply. A study published in the online open access journal BMC Public Health found this reduction is associated with a significant drop in hangings as a means of suicide.

Dr Cameron Stark led the research team from the Department of Public Health, NHS Highland. The research team based the analysis on routinely collected information for the period 1980-2004 from the General Register Office for Scotland (GROS). The data showed a 42% reduction in suicide rates among 15-29 year old men, from 42.5/100,000 in 2000 to 24.5/100 000 in 2004, There were no significant changes in trend in any other male age group in the period reviewed.