Elastic system of the rat ventral prostate and its modifications following orchiectomy

BACKGROUND. The extracellular matrix (ECM) has important roles in prostatic development, and marked stromal changes take place in the rat ventral prostate (VP) after androgen deprivation. However, little knowledge exists about individual ECM components.METHODS. The distribution of elastic fibers (EF) and elastic-related fibers (ERF) in the VP of castrated and control rats was investigated, using histochemistry and transmission electron microscopy (TEM).RESULTS. EF are barely detected in the prostatic stroma, but ERF are relatively abundant. Castration results in a relative increase in the number and thickness of ERF. TEM showed an open network of ECM microfibrils throughout the stroma and thin and short EF, which increase in number and thickness after orchiectomy.CONCLUSIONS. The presence of elastic system components in the rat VP warrants the deformability required for the secretion exclusion under the action of smooth muscle cells, and the castration-induced modification may be related to the contraction of the tissue and maintenance of peculiar arrangements of other ECM components. (C) 1997 Wiley-Liss, Inc.

Nonlinear characteristics of Cr2O3, WO3, ZnO and CoO doped SnO2 varistors

SnO2 based ceramics doped with 1.0 mol% ZnO, 1.0 mol% CoO, 0.1 mol% WO3 and 0.05 mol% Cr2O3 show varistor behavior with nonlinear coefficient alpha = 33, breakdown electric field E-B = 12.5 kV/cm, leakage current I = 0.63 mA/cm(2) and average grain size of 1.52 mu m. Experimental evidence shows that the addition of Cr2O3 improves the nonlinear properties of the samples significantly, the impedance data, represented by means of Nyquist diagrams, show a dramatic increase in the resistivity for the samples doped with Cr2O3. (C) 2005 Elsevier B.V. All rights reserved.

Root-system of peanuts as affected by phosphorus fertilization

There have been some responses of peanut roots to phosphorus. An experiment was carried out to study peanut root growth and distribution as related to P in the soil. The cultivars Tatu, Oira and Tup4 and the lines FCA 170 and FCA 265 were grown with or without P fertilization with 80 kg P2O5/ha, as triple superphosphate. The fertilizer was applied in the seed furrows. There was higher P contents in the 0-10 cm layer of the soil 36 days after P application. At 66 and 98 days after application, P contents of the soil were increased by fertilization down to 15 cm. There was no response of peanut roots to P fertilization. Oira showed the highest root lenght density and Tatu the lowert. There was a root concentration the first 15 cm of the soil. Oira with the largest root system showed the lowest P absorption, and Tatu, with the smallest root system absorbed as much P as the others.

Female reproductive system of ant species of the subfamily ponerinae: Review and new data

Literature data about the female reproductive system of some species in the subfamily Ponerinae are presented. Our project objective to compile a report containing the largest possible number of data about the reproductive system in Ponerinae for a better understanding of the reproductive biology of these Insects, was completed.

Influence of La2O3, Pr2O3 and CeO2 on the nonlinear properties of SnO2 multicomponent varistors

The influence of La2O3, Pr2O3 and CeO2 on a new class of polycrystalline ceramics with nonlinear properties based on SnO2, was investigated. La2O3 and Pr2O3 were found to precipitate at the grain boundary region, causing a considerable increase in the nonlinear behavior. It was found that CeO2 forms a solid solution in the bulk but. unlike La2O3 and Pr2O3, it does not increase the nonlinear behavior. A higher nonlinear coefficient of similar to80 was obtained for La2O3-doped SnO2-based systems. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Kinetics of photoinduced birefringence in the guest-host system of poly(methyl methacrylate) doped with azobenzene-containing crown ethers

The kinetics of the buildup and decay of photoinduced birefringence was examined in a series of host-guest systems: azobenzene-containing crown ethers, differing in the size of the crowns, dissolved in a poly (methyl methacrylate) matrix. In all samples, the kinetics of the buildup of the birefringence was reasonably described by a sum of two exponential functions, the time constants being inversely proportional to the intensity of the pumping light and the magnitudes of the signals at the saturation level depending on the pumping light intensity and sample thickness. The dark decays were best described by the stretched exponential function, with the characteristic parameters (time constant and stretch coefficient) being practically independent of the type of crown ether. The time constants of the signal decay were orders of magnitude shorter than the respective constants of the dark isomerization of the azo crown ethers, thus indicating that the process controlling the decay was a relaxation of the polymer matrix and/or a rearrangement of the flexible parts of the crowns. (C) 2007 Wiley Periodicals, Inc.

Nonlinear behavior of TiO2 center dot Ta2O5 center dot MnO2 material doped with BaO and Bi2O3

A study was made on the effect of the addition of BaO (0.025-0.05 mol%) and Bi2O3 (0.025-0.05 mol%) to the TiO2.Ta2O5.MnO2 material. The samples were characterized by X-ray diffraction, and current-voltage measurements were accomplished for determination of the nonlinear coefficient. An analysis was made to evaluate the microstructural characteristics of the materials. The most appropriate sintering conditions for the materials were analyzed with the purpose of obtaining the best nonlinear coefficient associated with the smallest breakdown electric field. After sintering at 1400 degreesC for 2 h, a low-voltage (30 V cm(-1)) varistor was obtained, which, however, presented a low nonlinear coefficient (6). It was found that the sintering conditions must be controlled in order to improve the electrical properties of these materials. (C) 2004 Elsevier B.V. All rights reserved.

INFLUENCE OF DIABETES-MELLITUS ON THE GLUTATHIONE REDOX SYSTEM OF HUMAN RED-BLOOD-CELLS

Several components of the erythrocyte-dependent glutathione redox system (reduced glutathione, GSH; oxidized glutathione, GSSG; glutathione peroxidase, GSH-Px; glutathione reductase, GSH-Red) were determined in patients with types I and II diabetes mellitus (DM). All groups studied were male subjects: G1, 20 young healthy individuals (aged 23.7 +/- 4.2 years); G2, 15 young insulin-treated type I DM patients; G3, 20 older insulin-treated type II DM patients; 04, 21 older oral hypoglycemic agent-treated type II DM patients; G5, 28 aged healthy individuals (aged 68.9 +/- 11.5 years). There were no differences between G1 and G2, G3 or G4 regarding erythrocyte GSH, GSSG, and GSH-Red (without FAD) levels. GSH-Px activity was significantly lower in G2 when compared to G1 (15.2 +/- 4.9 vs 20.6 +/- 6.6 IU/g Hb). The GSH-Red and GSH-Px activities and GSH levels were significantly higher in 03 (4.6 +/- 1.7 IU/g Hb, 20.2 +/- 8.7 IU/g Hb and 3.5 +/- 1.3-mu-M/g Hb) and G4 (5.0 +/- 2.2 IU/g Hb, 16.9 +/- 6.1 IU/g Hb and 5.0 +/- 2.3-mu-M/g Hb) when compared to G5 (3.4 +/- 0.9 IU/g Hb, 12.0 +/- 3.6 IU/g Hb and 2.3 +/- 0.9-mu-M/g Hb). The findings suggest that treatment of DM can stimulate the redox activity of red blood cells in aged subjects.

Nonresonant third-order nonlinear properties of NaPO3-WO3-Bi2O3 glasses in the near infrared

nonlinear (NL) refractive index, n(2), of NaPO3-WO3-Bi2O3 glass with different relative amounts of the constituents was measured at 1064 and 800 nm using the Z-scan and the thermally managed eclipse Z-scan techniques, respectively. The values of n(2) >= 10(-15) cm(2)/W and negligible NL absorption coefficient were determined. The large values of the NL refractive index and the very small NL absorption indicate that these materials have large potential for all-optical switching applications. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3212972]

Anatomy of the male reproductive system of Phrynops geoffroanus (Testudines: Chelidae).

The reproductive system of male Phrynops geoffroanus adults is macroscopically described and the variation in testicular biometry is evaluated. A pair of oval testes is connected by the efferent ductules to the epididymis, which continue as deferent ducts, which emerge in the penis. The volume of the gonads showed the highest averages during spring and summer months. GSI varied significantly throughout the year, with the highest averages observed in the months that correspond to the end of spring and the beginning of summer, when the reproduction of the species takes place, and the lowest averages were seen in winter, suggesting a cyclical testicular activity.