Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR)

Ventilatory differences between rat strains and genders have been described but the morphology of the phrenic nerve has not been investigated in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. A descriptive and morphometric study of the phrenic nerves of male (N = 8) and female (N = 9) SHR, and male (N = 5) and female (N = 6) WKY is presented. After arterial pressure and heart rate recordings, the phrenic nerves of 20-week-old animals were prepared for epoxy resin embedding and light microscopy. Morphometric analysis performed with the aid of computer software that took into consideration the fascicle area and diameter, as well as myelinated fiber profile and Schwann cell nucleus number per area. Phrenic nerves were generally larger in males than in females on both strains but larger in WKY compared to SHR for both genders. Myelinated fiber numbers (male SHR = 228 ± 13; female SHR = 258 ± 4; male WKY = 382 ± 23; female WKY = 442 ± 11 for proximal right segments) and density (N/mm²; male SHR = 7048 ± 537; female SHR = 10355 ± 359; male WKY = 9457 ± 1437; female WKY = 14351 ± 1448) for proximal right segments) were significantly larger in females of both groups and remarkably larger in WKY than SHR for both genders. Strain and gender differences in phrenic nerve myelinated fiber number are described for the first time in this experimental model of hypertension, indicating the need for thorough functional studies of this nerve in male and female SHR

Влияние электромагнитного состояния турбоагрегата на работоспособность его узлов. Диагностика, демагнитезация

Рассмотрены условия возникновения электроэрозионных повреждений узлов турбоагрегатов, а так же их характерные признаки. Даны рекомендации по диагностике и устранению электроэрозии на турбоагрегатах находящихся в эксплуатации. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/21587There considered conditions resulting in occurring electroerozion damage sites in turbine unit, as well as their characteristic features. There given recommendations concerning diagnosis and elimination of electroerozion on turbine units being in operation. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/2158

Bentonite/polymer compound development to application in drilling fluids: Part 2

The most important bentonite clays sources are placed at Paraíba state, Brazil. These clays are largely used as viscosity agent in drilling fluids. Unfortunately for some kinds of available clay their parameters are far from PETROBRAS standard. Treatments based on polymeric addition consist on method to improve such parameters. In order to improve these parameters, this work proposes a methodology to develop bentonite/polymers compound for use in water based drilling fluids. Besides the raw clay others samples have been evaluated: i) one sample of a commercial bentonite; ii) two samples of carboximethyl cellullose (CMC) and iii) one sample of partially-hydrolyzed polyacrylamide (PAM). Based on experimental planning, ten compositions of polymeric compound (mix of two and three polymers) have been evaluated. For each composition of polymeric compound three different concentrations was added to clay. All experimental fluids have been evaluated accordingly with PETROBRAS standard to determine apparent and plastic viscosity, yield stress, and water loss. The results of the analysis show that by polymeric treatment of bentonite clay with compound polymeric allow to obtain a mixture with improved rheologic properties. Finally, this procedure allows to use low quality bentonite clays for drilling fluids application.Os depósitos de bentonita da Paraíba constituem um dos mais importantes do país. Essas argilas são empregadas, dentre outras aplicações, como viscosificante em fluidos de perfuração. Contudo, atualmente, alguns tipos de argila encontradas nesses depósitos não apresentam os parâmetros exigidos pela PETROBRAS e a aditivação polimérica surge como alternativa para adequar essas propriedades. Sendo assim, este trabalho objetiva o desenvolvimento de compostos bentonita/polímeros para uso em fluidos de perfuração à base de água. Para tanto, foram estudadas uma amostra de argila bentonítica sódica industrializada da Paraíba, Brasil, duas amostras de carboximetilcelulose (CMC) e uma amostra de poliacrilamida (PAM). O dimensionamento do composto polimérico (misturas de dois e três polímeros) foi elaborado por meio do planejamento experimental, sendo estudadas dez diferentes composições. Os compostos poliméricos, em três diferentes concentrações, foram misturados à argila seca. Em seguida, foram preparados os fluidos de perfuração e determinadas as viscosidades aparente e plástica, o limite de escoamento e o volume de filtrado de acordo com as normas da PETROBRAS. Os resultados das análises mostraram que a aditivação da bentonita com o composto polimérico permite obter uma mistura com melhores propriedades reológicas e de filtração. Finalmente, esse procedimento permite o uso de argilas bentoníticas de qualidade inferior em fluidos de perfuração de poços de petróleo.20921

DEGRADABILIDADE in vitro DA PROTEÍNA DE ESPÉCIES ARBÓREAS DO SEMI-ÁRIDO BRASILEIRO

This experiment was carried out to evaluate the protein degradability in vitro of arboreal plants from Brazilian semi-arid. The plants tested were angico (Anadenanthera colubrina), algaroba (Prosopis juliflora), espinheiro (Acacia glomerosa), juazeiro (Ziziphus joazeiro) and soybean meal, which had crude protein values of 22,5 16,0, 22,0, 19,0 and 38,0%, respectively. Samples (60 mg) were incubated with McDougal (8 ml) and inoculated ruminal fluid (2 ml). Aliquots (1 ml) were taking after 0, 6, 12, 24, 36 and 48 hours for analysis of ammonia, soluble protein and microbial protein. Soybean meal and the algaroba showed larger ammonia production and concentration of soluble protein compared to the other treatments. Soybean meal also displayed higher values for microbial protein. The treatment with angico was the one that displayed closed values towards soybean in regard to microbial protein, in spite of showing lesser ammonia production. The largest value of potential degradability 66,47%, was observed for the treatment with soybean meal, followed by the algaroba 46,27% and of the angico 45,20. Very low degradability was observed for the espinheiro and juazeiro, 19,16 e16,63%, respectively. Among the studied plants the angico and the algaroba were better sources of protein.O experimento teve como objetivo avaliar a degradabilidade in vitro da proteína de plantas arbóreas do semi-árido brasileiro e do farelo de soja. As plantas utilizadas foram angico (Anadenanthera colubrina), algaroba (Prosopis juliflora), espinheiro (Acacia glomerosa), juazeiro (Ziziphus joazeiro) e o farelo de soja, com valores de proteína bruta de 22,5 16,0, 22,0, 19,0 e 38,0%, respectivamente. Amostras de cada planta (60 mg) foram incubadas em 8 ml de meio tampão de McDougal, com adição de 2 ml de inóculo ruminal. Nos tempos 0, 6, 12, 24, 36 e 48 horas após a incubação foi retirada uma alíquota de 1,0 ml para análise de amônia, proteína solúvel e proteína microbiana. O farelo de soja e a algaroba proporcionaram maiores produção de amônia e concentração de proteína solúvel em relação aos outros alimentos, sendo que o farelo de soja apresentou maior valor de proteína microbiana. O tratamento com o angico foi o que mais se aproximou à soja com relação ao valor de proteína microbiana, apesar da sua menor produção de amônia. O maior valor de degradabilidade potencial 66,47 %, foi observado no tratamento com farelo de soja, seguidos dos tratamentos da algaroba 46,27% e angico 45,20%. Foram observados valores de degradabilidade muito baixos para o espinheiro e juazeiro, 19,16 e 16,63%, respectivamente. O angico e a algaroba apresentaram-se como melhores fontes de proteína entre as plantas avaliadas

Design of a nanostructured mucoadhesive system containing curcumin for buccal application : from physicochemical to biological aspects

Mucoadhesive nanostructured systems comprising poloxamer 407 and Carbopol 974P® have already demonstrated good mucoadhesion, as well as improved mechanical and rheological properties. Curcumin displays excellent biological activity, mainly in oral squamous cancer; however, its physicochemical characteristics hinder its application. Therefore, the aim of this study was to develop nanostructured formulations containing curcumin for oral cancer therapy. The photophysical interactions between curcumin and the formulations were elucidated by incorporation kinetics and location studies. They revealed that the drug was quickly incorporated and located in the hydrophobic portion of nanometer-sized polymeric micelles. Moreover, the systems displayed plastic behavior with rheopexy characteristics at 37 °C, viscoelastic properties and a gelation temperature of 36 °C, which ensures increased retention after application in the oral cavity. The mucoadhesion results confirmed the previous findings with the nanostructured systems showing a residence time of 20 min in porcine oral mucosa under flow system conditions. Curcumin was released after 8 h and could permeate through the porcine oral mucosa. Cytotoxicity testing revealed that the formulations were selective to cancer cells over healthy cells. Therefore, these systems could improve the physicochemical characteristics of curcumin by providing improved release and permeation, while selectivity targeting cancer cells

Evaluation of mitochondrial activity in spermatozoids after collecting and posthawing in Boer and Alpine goats in autumn and spring

Caprine spermatozoa undergo glycolisis and mitocondrial respiration to keep the necessary energy balance to their transportation and other cellular functions. An objective test to evaluate quantitatively and qualitatively mitochondrial activity in caprine spermatozoa was applied in the analysis of semen samples of 9 bucks from Boer (n=5) and Alpine (n=4) breeds. Samples were collected and frozen in TRIS medium in two different year seasons. Semen collection was performed using artificial vagina to obtain 135 ejaculates, which were used to post-collection and post-frozen extended in sildes. To determine mitochondrial activity, a citochemical procedure developed and validated for HRUDKA (1987) was used. The technique is based on the enzymatic 3,3-diaminobenzidine (DAB) oxidation, where the reagent is polymerized and attached to the mitochondrial membrane throughout the spermatic intermediary piece. A medium level of citochemical activity (IAC) was determined as being 74,37%, 74,37% during Autumn and 77% e 77,75% during Spring for Boer and Alpine breeds, respectively. For post-collection IAC levels were 85,62% and 85,93 and for post-frozen 66% and 67,25% for Boer and Alpine breeds, respectively. ANOVA test was used to evaluate breed, post-collection, post-frozen, IAC rates and year season parameters. Differences were not noticed for breed, IAC rates and year season. Nonetheless, there was a significant effect among samples for post-collection and post-frozen analysis (POs espermatozóides caprinos realizam a respiração mitocondrial, mantendo um balanço energético necessário para o transporte e as demais funções celulares. Um teste objetivo de avaliação quantitativa e qualitativa da atividade mitocondrial em espermatozóides caprinos foi aplicado no sêmen de nove reprodutores das raças Boer (n=5) e Alpina (n=4) colhidos e congelados em diluidor TRIS em duas estações. A colheita do sêmen foi realizada com auxílio da vagina artificial, totalizando 135 ejaculados e foram confeccionados esfregaços com sêmen pós-colheita e pós-descongelação. Para a determinação da atividade mitocondrial foi utilizado o procedimento citoquímico desenvolvido e validado por HRUDKA (1987). Esta técnica é baseada na oxidação da 3,3-diaminobenzidine (DAB) pela enzima em reação em cadeia, onde o reagente é polimerizado e depositado na bainha mitocondrial ao longo da peça intermediária dos espermatozóides. Foi determinado um índice médio de atividade citoquímica (IAC) de 74,37%, 74,37% no outono, 77% e 77,75% na primavera. E 85,62% e 85,93 no pós-colheita, 66% e 67,25% pós-descongelação para as raças Boer e Alpina, respectivamente. As variáveis raças, pós-colheita e pós-descongelação, classes (IAC), e estação foram estudadas por meio de ANOVA. Não foram observadas diferenças estatísticas para raças, classes, bem como para as estações. Entretanto, efeito significativo entre as amostras pós-colheita e pós-descongelação (

Theoretical description of phase coexistence in model C60

We have investigated the phase diagram of the Girifalco model of C60 fullerene in the framework provided by the MHNC and the SCOZA liquid state theories, and by a Perturbation Theory (PT), for the free energy of the solid phase. We present an extended assessment of such theories as set against a recent Monte Carlo study of the same model [D. Costa et al, J. Chem. Phys. 118:304 (2003)]. We have compared the theoretical predictions with the corresponding simulation results for several thermodynamic properties. Then we have determined the phase diagram of the model, by using either the SCOZA, or the MHNC, or the PT predictions for one of the coexisting phases, and the simulation data for the other phase, in order to separately ascertain the accuracy of each theory. It turns out that the overall appearance of the phase portrait is reproduced fairly well by all theories, with remarkable accuracy as for the melting line and the solid-vapor equilibrium. The MHNC and SCOZA results for the liquid-vapor coexistence, as well as for the corresponding critical points, are quite accurate. All results are discussed in terms of the basic assumptions underlying each theory. We have selected the MHNC for the fluid and the first-order PT for the solid phase, as the most accurate tools to investigate the phase behavior of the model in terms of purely theoretical approaches. The overall results appear as a robust benchmark for further theoretical investigations on higher order C(n>60) fullerenes, as well as on other fullerene-related materials, whose description can be based on a modelization similar to that adopted in this work.Comment: RevTeX4, 15 pages, 7 figures; submitted to Phys. Rev.

Jet disc coupling in black hole binaries

In the last decade multi-wavelength observations have demonstrated the importance of jets in the energy output of accreting black hole binaries. The observed correlations between the presence of a jet and the state of the accretion flow provide important information on the coupling between accretion and ejection processes. After a brief review of the properties of black hole binaries, I illustrate the connection between accretion and ejection through two particularly interesting examples. First, an INTEGRAL observation of Cygnus X-1 during a 'mini-' state transition reveals disc jet coupling on time scales of orders of hours. Second, the black hole XTEJ1118+480 shows complex correlations between the X-ray and optical emission. Those correlations are interpreted in terms of coupling between disc and jet on time scales of seconds or less. Those observations are discussed in the framework of current models.Comment: Invited talk at the Fifth Stromlo Symposium: Disks, Winds & Jets - from Planets to Quasars. Accepted for publication in Astrophysics & Space Scienc