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Biomedical subjects

M Coman

Publications and source records attributed to M Coman.

13 recordsLinked to original sources
PubMed2005

Recoil polarization for delta excitation in pion electroproduction.

We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W = 1.23 GeV at Q(2) = 1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re (S(1+)/M(1+)) = -(6.84 +/- 0.15)% and Re (E(1+)/M(1+)) = -(2.91 +/- 0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and ll(pi) < or = 1 truncation.

Journal Article↗
PubMed2004

Measurement of the electric form factor of the neutron at Q2=0.5 and 1.0 GeV2/c2.

The electric form factor of the neutron was determined from measurements of the d-->(e-->,e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find G(n)(E)=0.0526+/-0.0033(stat)+/-0.0026(sys) and 0.0454+/-0.0054+/-0.0037 at Q(2)=0.5 and 1.0 (GeV/c)(2), respectively.

Journal Article↗
PubMed2003

Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium.

We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90 degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma) greater, similar 3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.

Journal Article↗
PubMed2000

Jumping from the Westgate Bridge, Melbourne.

OBJECTIVE: To describe characteristics of people who jumped from the Westgate Bridge (identifying risk factors for attempted suicide) and to determine why people may survive such a jump. DESIGN AND SETTING: A retrospective case review (coroners' reports and hospital records) of all people known to have jumped from the Westgate Bridge between 1991 and 1998. RESULTS: We identified 62 people who jumped from the Westgate Bridge over the study period. Seven survived. Forty-one (74%) of those who jumped were male. The average age was 33.8 years (range, 15-58 years). Forty-four (71%) had known mental illness (23 schizophrenia, 21 depression). Thirty-nine (63%) landed in water, falling from a height of 58.5 m. Nineteen (31%) fell onto land and in four cases (6%) the landing site was not determined. All survivors landed in water. Six people died from drowning after the fall, and in eight more deaths drowning was a major or contributing factor. All jumps resulted from suicidal intent, and 12 people (19%) had positive toxicology screens for alcohol or other non-prescription drugs at postmortem. CONCLUSIONS: Each year the Westgate Bridge is the scene of about eight suicide attempts by jumping (particularly by men with active psychiatric illness). Some deaths by drowning could be prevented by early detection and rapid emergency service response. The erection of an effective safety barrier would probably prevent more deaths.

Adolescent↗
PubMedDate not supplied

Nuclear magnetic resonance study of changes induced by the energy of ultrasonic field in the lungs.

156 laboratory mice were exposed to ultrasonic (US) waves under 12 different conditions. After exposure to ultrasounds, the left lung of each animal was studied morphopathologically and then analysed by nuclear magnetic resonance (NMR) spectroscopy. The study emphasized the possibility of hemorrhagical lesions in the lung through US and the fact that both measurement techniques (for T1 and T2) are alike in sensitivity. The effect on the lung is depending on the intensity and time of exposure to US.

Animals↗
PubMedDate not supplied

Histological and histochemical alteration in certain Black Sea bivalves submitted to accidental pollution.

Due to their microphage capacity, two-valve shells have great biologic importance: they clean the environment of harmful microorganisms and decaying organic compounds which result in water purification, water filtering by means of adaptive structures of digestive system and, indirectly, by those of respiratory, circulatory and excretive system is of major significance. Waste materials derived from animal metabolism coalesce in larger aggregates which sink and deposit onto the bottom, thus enabling the bivalvular shells to contribute to developing and securing adequate conditions for the productive cycle of marine environment and even twining themselves into food for animals. Our study makes a histological, histochemical and histometric survey of branchia (ctenidia) of Mytilus galloprovinciallis so as to enlarge the scant body of knowledge on the topic in reference literature.

Animals↗
PubMedDate not supplied

Aspects of the cell population in the skin of the guinea pig exposed to hyperbaric-hyperoxic environment.

Knowing that in hyperbaric-hyperoxic environment, the production of free oxygen radicals is increased, with the direct implications on cellular metabolism, our study follows the influence of the hyperbaric environment, a very complex organ that is exposed to directly to this environment. We used a group of 10 guinea pigs split into to lots (test and control lots). The test lot was exposed for consecutive days to an ambient pressure of 6 ATM for a period of 30 min. After 50 days both groups was given lethal doses of pentobarbital, afterwards skin was harvested and fixed into Bouin's fluid and formaline, than paraffin embedded. The slides stained with Haematoxylin-Eosin and trichromic Van Gieson. The epidermal fields examined by us revealed no significant variations of nuclear number, though the mean saturation of nuclei was significantly greater in test animals than in the control group, while the nuclear area fraction was higher in the control group. The melanin load of the epidermal cells was increased in the control animals. The presence of intraepidermal vacuoles was identified, their amount being almost double in test animals than in the control group.

Adaptation, Physiological↗
PubMedDate not supplied

Serum alphaphetoprotein in chronic hepatitis. Scintigraphic correlations.

On studying a number of 59 patients with chronic active hepatitis and with hepatic cirrhosis, with 37% and 41% cases respectively our research-works have proved increased serum AFP concentrations varying between 30-45 ng/ml, their values being much larger in active hepatic cirrhosis. The significant increase in aminotransferase and bilirubin has been correlated with a more severe stage of the hepatic disease. The gamma glutamyltranspeptidase (GGTP) assays for 9 of the 17 cases with active chronic hepatitis and for 17 cases with alcoholic hepatitis have shown a 6-15 times increase of this enzyme as compared to the other cases. Very high values of AFP, ranging between 300-900 ng/ml, have been found in the hepatic adenocirrhosis cases. A certain correlation between the AFP modifications and the scintigraphy has been found in 5 of the cases with malignant changes, in contrast with the AFP low and sporadic increase in the case of other gastrointestinal tract tumors. The scintigraphic modifications have been evident with low or multiple lacunary fixations, in considerable sizes and forms, with irregular edges, their dimensions, depending upon the disease evolution stage.

Adult↗
PubMedDate not supplied

Effects of chronic ethanol intake on isozyme patterns of liver alcohol dehydrogenase.

ADH isozyme patterns in cirrhotic humans who had chronic alcoholic histories were studied to elucidate the relationship between their changes and the degree of liver damage. Liver ADH activity was significantly reduced in alcoholic cirrhosis. Electrophoretic separation of ADH isozyme revealed three fractions : two faster moving anodic isozymes (A1, A2) and one cathodic from the intermediate mobility (C). No significant differences was observed in the ADH isozyme patterns among control cases. The percentages of A1, A2 and C forms were 15 - 20%, 60 - 70% and 5 - 10% of the total enzyme activities, respectively. The isozyme patterns of ADH in the liver of cirrhotic patients were somewhat different from those in control cases : the average activity of A1 and C isozyme decreased markedly while the A2 form could not be observed.

Alcohol Oxidoreductases↗