EXPERIMENTAL STUDY OF pn ANNIHILATIONS BETWEEN 1.0 AND 1.6 GeV/c

pn annihilations into three and five charged mesons with or without neutrals have been studied, in order to measure the contributions of the various final states to the 5.5 mb enhancement discovered in the total I=1 NN cross section at 2190 MeV total CM energy. Fits have been performed to the cross sections as functions of the incident p momentum with background plus a resonant term. The fits show enhancement in several final states, the statistically most significant one being in the reaction pn to pi /sup +/ pi /sup -/ pi /sup -/ (0.51+or-0.13 mb over a background of 1.4 mb). Less significant effects are also found in all other pionic annihilation final states regardless of their G-parity. (2 refs)

Propriedades tensiométricas do peritônio da paca (Cuniculus paca) a fresco e conservado em glicerina 98%

In constant searching for alternative biological material to perform implants and new options of experimental animal models, the objective of this investigation was to describe the mechanical properties of the peritoneum paca (Cuniculus paca Linnaeus, 1766) fresh and preserved in 98% glycerin. Samples of fresh and preserved in glycerin for periods of 30, 60 and 90 days were subjected to mechanical tests. Four adult animals, male or female, with mean body weight of eight kilograms, were used for collecting samples of the peritoneum. All tissues preserved in glycerin 98% showed a decrease in stiffness and increase in ductility and toughness. Considering the maximum force applied to the peritoneum, significant increase was observed in values (p<0.01) of samples stored for 60 and 90 days when compared to fresh material. In relation to the stretch variable, an increase was observed in all storage time of glycerin samples, verifying significant difference (p<0.01) when compared with the fresh samples. The variable area also showed significance (p <0.01) between the values of the fresh samples (5.40 mm(2)) and preserved in the glycerin by periods of 30 days (4.50 mm(2)), 60 days (9.00 mm(2)) and 90 days (7.20 mm(2)), thus indicating that the area of this membrane increased by 0.033 mm(2) per day. Generally, it was concluded that the 98% glycerin is a substance effective for the preservation of the peritoneum of the agouti paca, therefore improves its mechanical properties allowing the support membranes greater deformation forces. Thus, the results obtained in mechanical tests of the peritoneum of paca suggest its use as an alternative biological material.Univ Estadual Julio de Mesquita Filho, Dept Morfol & Fisiol Anim, BR-14884900 Jaboticabal, SP, BrazilUniv Fed Parana UFPR, Setor Ciencias Exatas, Dept Fis, BR-81531990 Curitiba, PR, BrazilUniv Sao Paulo, Fac Med Ribeirao Preto, Dept Biomecan Med & Reabilitacao Aparelho Locomot, BR-14049900 Ribeirao Preto, SP, BrazilUniv Estadual Julio de Mesquita Filho, Dept Morfol & Fisiol Anim, BR-14884900 Jaboticabal, SP, Brazi

Follicular dynamics and production of oocytes in young Nellore heifers with energetic supplementation

To verify the effects of energy supplementation and fat on follicular dynamics, metabolic profile and the production of oocytes, 15 young heifers (Bos taurus indicus) with an average age of 14 months and with an initial weight of 256.35 kg were assigned to two treatments according to weight and follicular population as evaluated by ultrasonography: in T1 (1.0 × M), animals received 100% of the energy requirements for maintenance; in T2 (1.7 × M), animals received 170% of the energy requirements for maintenance, achieved by the addition of 200 g of Megalac®. After a period of adaptation to the diet, the treatments, blood collection and follicular aspirations were started using a randomized design. The dry matter intake and weight gain were lower in the 1.0 × M group than in the 1.7 × M group. No differences were found in the plasma progesterone concentrations, albumin, glucose, urea or gonadotropin (FSH and LH) levels between the groups. The mean concentrations of cholesterol were higher in the 1.7 × M group. The total number of small (<4 mm) and medium follicles (4-8 mm) was not altered by the treatments, but the number of small follicles increased on days 1 and 2 of the estrous cycle, with higher values found in the 1.7 × M group. The average of the oocytes also increased (9.50±2.1 and 12.5±4.4 for the 1.0 × M and 1.7 × M groups, respectively). The rapid increase in the amount of energy offered in the diet changes the amount of follicles and oocytes available for follicular aspiration (OPU) in young heifers without changing their metabolic profile

Cathodo And Photoluminescence Studies Of Non-stoichiometric Amorphous Silicon Carbide And Nitride

The room temperature cathodoluminescence of non-stoichiometric amorphous silicon carbide and nitride produced by glow discharge is reported. The photoluminescence emission and excitation spectra of silicon carbide samples are presented. Also, it was observed that the powder deposited onto the contraelectrode during the discharge shows efficient room temperature photo luminescence emission. © 1989.1151-34244GSK; GlaxoSmithKlineLeamy, Charge collection scanning electron microscopy (1982) Journal of Applied Physics, 53 (6)Alvarez, Fragnito, Prieto, Chambouleyron, Visible light emission from reverse biased amorphous silicon carbide P-I-N structures (1987) Journal of Non-Crystalline Solids, 97-98, p. 131