Bringing measuring accuracy to radical treatment

Significant progress made in evaluating the density of active species used in medical applications of plasma physics could improve the accuracy of treatment

2012-11-12

(Press-News.org) An international team of scientists working at the Plasma Technology research unit at Ghent University, Belgium, has determined for the first time the absolute density of active substances called radicals found in a state of matter known as plasma, in a study about to be published in EPJ D. These findings could have important implications for medicine—for example, for stimulating tissue regeneration, or to induce a targeted antiseptic effect in vivo without affecting neighbouring tissues.

Qing Xiong and colleagues utilised laser fluorescence spectroscopy (LIF), a detection method used to estimate the density of radicals in plasma. Plasma is made of charged species, active molecules such as radicals and atoms.

The authors chose to focus on OH radicals because they are one of the most important reactive species in plasma science due to their high level of oxidation. This means that chemical reactions with OH initiate the destruction of harmful components either in the human body or in nature such as carbon monoxide, volatile organic compounds and methane.

The problem is that, up to now, laser-induced fluorescent capability to measure the absolute density of radicals has been very limited because of issues with registering and analysing the fluorescence signal.

In this study, the authors present a simplified model which takes into account energy transfer stemming from the radicals' vibrations. It can be used to analyse the LIF signal at regular atmospheric pressure. They then confirm the validity of their model experimentally, with a plasma jet made of Argon gas mixed with water molecules.

The calculation of one-dimensional line-averaged OH density made in this paper could also be extended to a two-dimensional spatial resolution of the OH radicals in future work.

### Reference: Q. Xiong, A. Nikiforov, L. Li2, N. Britun, R. Snyders, X. P. Lu, C. Leys, Absolute OH density determination by laser induced fluorescence spectroscopy in an atmospheric pressure RF plasma jet, European Physical Journal D, DOI: 10.1140/epjd/e2012-30474-8

For more information, please visit www.epj.org

The full-text article is available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

Duke Medicine news -- Genome sequencing of Burkitt Lymphoma reveals unique mutation

2012-11-12

DURHAM, N.C. – In the first broad genetic landscape mapped of a Burkitt lymphoma tumor, scientists at Duke Medicine and their collaborators identified 70 mutations, including several that had not previously been associated with cancer and a new one that was unique to the disease. Findings from the genetic sequencing of Burkitt lymphoma, an aggressive form of lymphoma, could be used to develop new drugs or aim existing therapies at mutations known to be susceptible. The researchers published their findings online Sunday, Nov. 11, 2012, in the journal Nature Genetics. "This ...

News from Annals of Internal Medicine

2012-11-12

Philadelphia, November 12, 2012 – A new article being published early online in Annals of Internal Medicine describes the diagnosis and treatment protocol established in a Roanoke, Va. hospital to care for dozens of patients presenting with suspected fungal meningitis related to contaminated epidural spinal injections. This unprecedented surge of patients seeking care for a rare central nervous system (CNS) infection required physicians to react quickly with little data to guide treatment decisions. The authors suggest that the data collected from these cases may fill information ...

Genetic link between pancreatitis and alcohol consumption, says Pitt team

2012-11-12

PITTSBURGH, Nov. 12, 2012 – A new study published online today in Nature Genetics reveals a genetic link between chronic pancreatitis and alcohol consumption. Researchers from the University of Pittsburgh School of Medicine and more than 25 other health centers across the United States found a genetic variant on chromosome X near the claudin-2 gene (CLDN2) that predicts which men who are heavy drinkers are at high risk of developing chronic pancreatitis. This finding enables doctors to identify people with early signs of pancreatitis or an attack of acute pancreatitis ...

Job stress and mental health problems contribute to higher rates of physician suicide

2012-11-12

ANN ARBOR, Mich. — Doctors who commit suicide appear to be under-treated for mental health problems, despite their seemingly good access to health care, a new University of Michigan study shows. Although more physicians than non-physicians in the study had known mental health problems prior to suicide, this didn't translate into a higher rate of antidepressant use, according to the study, which appears in General Hospital Psychiatry and provides a deeper look at why physicians may have a higher-than-average suicide rate. Major depression is a known risk factor for ...

Robots enable scar-free hysterectomies for some women

2012-11-12

AUGUSTA, Ga. – The precision and three-dimensional view provided by robots can enable essentially scar-free surgery for some women needing hysterectomies, physicians report. The case report in the Journal of Minimal Access Surgery is of a 46-year-old physically fit female with a history of excessive bleeding and benign growths on her uterus. Her surgery was performed through a two inch-long incision in the belly button, the thinnest part of the abdomen, using the robotic arms in a "chopstick" fashion, said Dr. John R. Lue, Chief of the Medical College of Georgia Section ...

Desecrated ancient temple sheds light on early power struggles at Tel Beth-Shemesh

2012-11-12

Tel Aviv University researchers have uncovered a unique 11th century BCE sacred compound at the site of Tel Beth-Shemesh, an ancient village that resisted the aggressive expansion of neighboring Philistines. The newly discovered sacred complex is comprised of an elevated, massive circular stone structure and an intricately constructed building characterized by a row of three flat, large round stones. Co-directors of the dig Prof. Shlomo Bunimovitz and Dr. Zvi Lederman of TAU's Sonia and Marco Nadler Institute of Archaeology say that this temple complex is unparalleled, ...

FASEB urges biomedical research community to speak out against sequestration

2012-11-12

Bethesda, MD – The Federation of American Societies for Experimental Biology (FASEB) is rallying the biomedical research community to advocate against devastating funding cuts facing the nation's research agencies unless Congress acts before the end of the year. Under sequestration, the National Institutes of Health (NIH) could lose $2.8 billion and would fund 25 percent (2,300) fewer grants. The National Science Foundation (NSF) could be cut by nearly $600 million. More than 5,800 emails have been sent to Congress in response to a FASEB e-action alert urging individuals ...

National study shows protective eyewear reduces eye, head, and facial injuries

2012-11-12

PROVIDENCE, R.I. – A new study conducted by researchers at Hasbro Children's Hospital, the Center for Injury Research and Policy of The Research Institute at Nationwide Children's Hospital, Fairfax (VA) County Public Schools, and Boston Children's Hospital has found that high school field hockey players competing in states with mandated protective eyewear have significantly lower rates of head, eye, and facial injuries when compared to players who compete in states without protective eyewear mandates. Each academic year, an estimated 63,000 girls participate in high ...

New cause of thyroid hormone deficiency discovered

2012-11-12

International researchers, including a team at McGill University, have discovered a new cause for thyroid hormone deficiency, or hypothyroidism. This common endocrine disorder is typically caused by problems of the thyroid gland, and more rarely, by defects in the brain or the pituitary gland (hypophysis). However, a new cause of the disease has been discovered from an unsuspected source and is reported in the journal Nature Genetics. The scientists, led by McGill Professor Daniel Bernard, Department of Pharmacology and Therapeutics in the Faculty of Medicine, identified ...

More scientific research of 'fracking' urged in Pennsylvania

2012-11-12

"Pennsylvania has opened up its doors to fracking in ways that many other states in the U.S. have not," said David Dausey, Ph.D., chair of the Mercyhurst University Public Health Department. "We don't know enough about the environmental and human health effects of fracking and, as a result, Pennsylvania has become the home of experimental fracking." Dausey discusses his concerns in this month's episode of The Dausey File: Public Health News Today. Hydraulic fracturing or fracking is a controversial method to extract natural gas or petroleum from subterranean shale ...