UPI NewsTrack Health and Science News

Scientists discover repulsing light force

NEW HAVEN, Conn., July 15 (UPI) -- Yale University researchers say they've discovered a "repulsive" light force that can be used to control components on silicon microchips.

The scientists said their finding is important because it means future nanodevices might be controlled by light rather than electricity.

The same Yale team of scientists previously discovered an "attractive" force of light and showed how it could be manipulated to move components in semiconducting micro- and nano-electrical systems. Now they've discovered a complementary repulsing force that scientists had theorized existed, but had never proved.

"This completes the picture," said Assistant Professor Hong Tang, who led the study. "We've shown that this is indeed a bipolar light force with both an attractive and repulsive component."

Such light forces might eventually control telecommunications devices that would require far less power, but would operate much faster than today's conventional counterparts, Tang said, noting an added benefit of using light rather than electricity is that it can be routed through a circuit with almost no signal interference and eliminates the need for large numbers of electrical wires.

The team reports its findings in the online early edition of the journal Nature Photonics.

New Hodgkin's lymphoma treatment reported

PROVIDENCE, R.I., July 15 (UPI) -- U.S. medical scientists say they have developed a new chemotherapy regimen for pediatric Hodgkin's lymphoma patients.

Dr. Cindy Schwartz of Brown University Medical School's Hasbro Children's Hospital said the new treatment enhances efficacy through dose-dense drug delivery, while simultaneously reducing the long-term risks presented by high cumulative dose chemotherapy. Schwartz said current therapy for the disease in the United States did not include the most modern treatment models, in large part because it was one of the first malignancies for which a curative chemotherapy regimen was developed.

"For decades, the chemotherapy regimens known as MOPP and ABVD had been the standard treatment options for these patients," said Schwartz. "However, while they yielded excellent survival rates, they often resulted in long-term effects from toxicity, including infertility, second malignancy and cardiopulmonary toxicity. With the new treatment paradigm we've developed … we've been able to cure the cancer while reducing the risk of long-term effects on our patients."

Schwartz and her colleagues report their findings in the online early edition of the journal Blood.

System created to make paper biosensors

HAMILTON, Ontario, July 15 (UPI) -- Canadian scientists say they've created a technology similar to inkjet printing that can be used in making paper-based biosensors to detect harmful toxins.

McMaster University Associate Professor John Brennan and his research team say they've developed a method of printing a toxin-detecting biosensor on paper. The biosensor can be used to detect toxins that can cause food poisoning or that can be used as bioterrorism agents, the scientists said.

The researchers said their process involves formulating an ink like the one found in computer printer cartridges, but comprised of biocompatible silica nanoparticles. That ink is first deposited on paper, followed by a second ink containing an enzyme, with the resulting bio-ink forming a thin film of enzyme that is entrapped in the silica on paper.

When the enzyme is exposed to a toxin, reporter molecules in the ink change color in a manner corresponding to the concentration of the toxin in the sample, the scientists said.

The researchers said their goal is to provide a rapid, portable, disposable and inexpensive way of detecting harmful substances, including toxins, pathogens and viruses, without the need for sophisticated instrumentation.

The research is reported in the journal Analytical Chemistry.

Child porn not a sex offense risk factor

ZURICH, Switzerland, July 15 (UPI) -- For men without a prior sex offense conviction, consumption of child pornography does not represent a risk factor for a sex offense, Swiss researchers say.

Frank Urbaniok of the Canton of Zurich Department of Justice in Switzerland and colleagues studied 231 men convicted of consuming child pornography in 2002.

The study, published in the journal BMC Psychiatry, found 1 percent had gone on to commit a hands-on sex offense in the following six years.

"Our results support the assumption that these consumers, in fact, form a distinct group of sex offenders. Probably, the motivation for consuming child pornography differs from the motivation to physically assault minors," Urbaniok said in a statement.

"Furthermore, the recidivism rates of 1 percent for hands-on and 4 percent for hands-off sex offenses were quite low."

Due to the widespread use of the Internet, child pornography consumers today may differ from our sample in some socioeconomic aspects, such as in the level of education or level of income, Urbaniok said.

"Nevertheless, there are two relevant and practical findings that seem to be robust," Urbaniok said. "For consumers of child pornography without a criminal history, the prognosis for hands-on sex offenses and for recidivism with child pornography is favorable."