Anatomical Features Of The Urethra And Urinary Bladder Catheterization In Female Mice And Rats. An Essential Translational Tool [características Anatômicas Da Cateterização Da Uretra E Bexiga De Camundongos E Ratos Fêmeas. Instrumento Essencial Na Pesquisa Pré Clínica]

PURPOSE: To present fundamental anatomical aspects and technical skills necessary to urethra and urinary bladder catheterization in female mice and rats. METHODS: Urethral and bladder catheterization has been widely utilized for carcinogenesis and cancer research and still remains very useful in several applications: from toxicological purposes as well as inflammatory and infectious conditions to functional aspects as bladder dynamics and vesicoureteral reflux, among many others. RESULTS: Animal models are in the center of translational research and those involving rodents are the most important nowadays due to several advantages including human reproducibility, easy handling and low cost. CONCLUSIONS: Although technical and anatomical pearls for rodent urethral and bladder access are presented as tackles to the advancement of lower urinary tract preclinical investigation in a broaden sight, restriction to female animals hampers the male microenvironment, demanding future advances.26SUPPL. 2106110Reis, L.O., Fávaro, W.J., Ferreira, U., Billis, A., Fazuoli, M.G., Cagnon, V.H., Evolution on experimental animal model for upper urothelium carcinogenesis (2010) World J Urol, 28, pp. 499-505Mulder, G.J., Scholtens, E., Meijer, D.K., Collection of metabolites in bile and urine from the rat (1981) Methods Enzymol, 77, pp. 21-30Krinke, G.J., (2000) The Laboratory Rat, , San Diego, CA: Academic PressPhillips, J.I., Davies, I., The comparative morphology of the bladder and urethra in young and old female C57BL/Icrfat mice (1980) Exp Geront, 15, pp. 551-562Andersson, K.E., Arner, A., Urinary bladder contraction and relaxation: Physiology and pathophysiology (2004) Physiol Rev, 84, pp. 935-986Reis, L.O., Pereira, T.C., Favaro, W.J., Cagnon, V.H., Lopes-Cendes, I., Ferreira, U., Experimental animal model and RNA interference: A promising association for bladder cancer research (2009) World J Urol, 27, pp. 353-361Marini, R.P., Esteves, M.I., Fox, J.G., A technique for catheterization of the urinary bladder in the ferret (1994) Lab Anim, 28, pp. 155-15

Electronic polarization in pentacene crystals and thin films

Electronic polarization is evaluated in pentacene crystals and in thin films on a metallic substrate using a self-consistent method for computing charge redistribution in non-overlapping molecules. The optical dielectric constant and its principal axes are reported for a neutral crystal. The polarization energies P+ and P- of a cation and anion at infinite separation are found for both molecules in the crystal's unit cell in the bulk, at the surface, and at the organic-metal interface of a film of N molecular layers. We find that a single pentacene layer with herring-bone packing provides a screening environment approaching the bulk. The polarization contribution to the transport gap P=(P+)+(P-), which is 2.01 eV in the bulk, decreases and increases by only ~ 10% at surfaces and interfaces, respectively. We also compute the polarization energy of charge-transfer (CT) states with fixed separation between anion and cation, and compare to electroabsorption data and to submolecular calculations. Electronic polarization of ~ 1 eV per charge has a major role for transport in organic molecular systems with limited overlap.Comment: 10 revtex pages, 6 PS figures embedde

Caracterização da produção agroecológica do sul do Rio Grande do Sul e sua relação com a mecanização agrícola.

A agricultura agroecológica tem-se destacado como uma das alternativas de renda para os pequenos agricultores devido à crescente busca por parte da população por alimentação mais saudável. No Rio Grande do Sul, a Associação Regional de Produtores Agroecológicos da Região Sul (Arpasul), constituída por 48 famílias, é representativa do processo de produção e de comercialização de produtos agroecológicos, servindo como referencial para o presente estudo. O objetivo principal deste trabalho foi o levantamento das necessidades dos produtores agroecológicos em relação à mecanização agrícola. As informações obtidas foram baseadas no sistema de produção utilizado, sendo caracterizados aspectos referentes à propriedade, às operações agrícolas e às necessidades específicas de máquinas e implementos. Por meio deste estudo, foi evidenciada a carência no atendimento das demandas específicas, na área de máquinas agrícolas para esse segmento, podendo servir como referencial para o desenvolvimento de novas máquinas e/ou aperfeiçoamento das existentes. A semeadora de milho e feijão foi a máquina que a maioria dos agricultores pesquisados indicou como sua maior necessidade

Crossover and self-averaging in the two-dimensional site-diluted Ising model

Using the newly proposed probability-changing cluster (PCC) Monte Carlo algorithm, we simulate the two-dimensional (2D) site-diluted Ising model. Since we can tune the critical point of each random sample automatically with the PCC algorithm, we succeed in studying the sample-dependent $T_c(L)$ and the sample average of physical quantities at each $T_c(L)$ systematically. Using the finite-size scaling (FSS) analysis for $T_c(L)$, we discuss the importance of corrections to FSS both in the strong-dilution and weak-dilution regions. The critical phenomena of the 2D site-diluted Ising model are shown to be controlled by the pure fixed point. The crossover from the percolation fixed point to the pure Ising fixed point with the system size is explicitly demonstrated by the study of the Binder parameter. We also study the distribution of critical temperature $T_c(L)$. Its variance shows the power-law $L$ dependence, $L^{-n}$, and the estimate of the exponent $n$ is consistent with the prediction of Aharony and Harris [Phys. Rev. Lett. {\bf 77}, 3700 (1996)]. Calculating the relative variance of critical magnetization at the sample-dependent $T_c(L)$, we show that the 2D site-diluted Ising model exhibits weak self-averaging.Comment: 6 pages including 6 eps figures, RevTeX, to appear in Phys. Rev.