663 research outputs found

    Alternativas na Colocação de Cateteres em Hemodiálise

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    Background: Although vascular access is essential for adequate haemodialysis delivery, the systematic use of a patient's venous patrimony may eventually lead to exhaustion of suitable sites for placement of a new vascular access. Case Report: We present two cases of such patients. In the first one we inserted a 55cm catheter through the left external iliac vein, and a 40cm translumbar catheter was placed in the second one. Both interventions were performed percutaneously under radiological guidance. Both patients were anticoagulated after the procedure. Conclusion: Unusual sites for haemodialysis catheter placement may be life saving in selected situations and offer safe and viable alternatives for adequate haemodialysis delivery

    Global priorities for conservation across multiple dimensions of mammalian diversity

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    Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity-taxonomic, phylogenetic, and traits-and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts

    Calcium-dependent Inactivation Terminates Calcium Release in Skeletal Muscle of Amphibians

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    In skeletal muscle of amphibians, the cell-wide cytosolic release of calcium that enables contraction in response to an action potential appears to be built of Ca2+ sparks. The mechanism that rapidly terminates this release was investigated by studying the termination of Ca2+ release underlying sparks. In groups of thousands of sparks occurring spontaneously in membrane-permeabilized frog muscle cells a complex relationship was found between amplitude a and rise time T, which in sparks corresponds to the active time of the underlying Ca2+ release. This relationship included a range of T where a paradoxically decreased with increasing T. Three different methods were used to estimate Ca2+ release flux in groups of sparks of different T. Using every method, it was found that T and flux were inversely correlated, roughly inversely proportional. A simple model in which release sources were inactivated by cytosolic Ca2+ was able to explain the relationship. The predictive value of the model, evaluated by analyzing the variance of spark amplitude, was found to be high when allowance was made for the out-of-focus error contribution to the total variance. This contribution was estimated using a theory of confocal scanning (Ríos, E., N. Shirokova, W.G. Kirsch, G. Pizarro, M.D. Stern, H. Cheng, and A. González. Biophys. J. 2001. 80:169–183), which was confirmed in the present work by simulated line scanning of simulated sparks. Considering these results and other available evidence it is concluded that Ca2+-dependent inactivation, or CDI, provides the crucial mechanism for termination of sparks and cell-wide Ca2+ release in amphibians. Given the similarities in kinetics of release termination observed in cell-averaged records of amphibian and mammalian muscle, and in spite of differences in activation mechanisms, CDI is likely to play a central role in mammals as well. Trivially, an inverse proportionality between release flux and duration, in sparks or in global release of skeletal muscle, maintains constancy of the amount of released Ca2+

    Concerted vs. Sequential. Two Activation Patterns of Vast Arrays of Intracellular Ca2+ Channels in Muscle

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    To signal cell responses, Ca2+ is released from storage through intracellular Ca2+ channels. Unlike most plasmalemmal channels, these are clustered in quasi-crystalline arrays, which should endow them with unique properties. Two distinct patterns of local activation of Ca2+ release were revealed in images of Ca2+ sparks in permeabilized cells of amphibian muscle. In the presence of sulfate, an anion that enters the SR and precipitates Ca2+, sparks became wider than in the conventional, glutamate-based solution. Some of these were “protoplatykurtic” (had a flat top from early on), suggesting an extensive array of channels that activate simultaneously. Under these conditions the rate of production of signal mass was roughly constant during the rise time of the spark and could be as high as 5 μm3 ms−1, consistent with a release current >50 pA since the beginning of the event. This pattern, called “concerted activation,” was observed also in rat muscle fibers. When sulfate was combined with a reduced cytosolic [Ca2+] (50 nM) these sparks coexisted (and interfered) with a sequential progression of channel opening, probably mediated by Ca2+-induced Ca2+ release (CICR). Sequential propagation, observed only in frogs, may require parajunctional channels, of RyR isoform β, which are absent in the rat. Concerted opening instead appears to be a property of RyR α in the amphibian and the homologous isoform 1 in the mammal

    Production Per Animal and Use of Intake Estimatives to Predicted Animal Productivity in \u3cem\u3ePennisetum Purpureum\u3c/em\u3e cv. Mott and \u3cem\u3eCynodon\u3c/em\u3e spp cv. Tifton 85 Pastures

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    Dairy production is a very important activity in southern Brazil, being an essential source of income to small household farms. Milk production from pastures is an alternative to reduce costs in dairy systems. Some C4 grasses, such as dwarf elephant grass (DEG) and Tifton 85, have presented high animal production per animal and per area. Although studies evaluating milk production from these pastures are rare in south Brazil, in vitro studies have demonstrated that the nutritional value of these forages is higher than production registered in grazing. So, it is possible that, in spite of a high intrinsic nutritional value, limitation on cows’ productivity is linked to the food’s capacity of conversion to milk and/or management conditions that limit forage intake. Leaf mass in pastures is a factor that determinates forage intake, as cows prefer leaf to other parts of plants. In this context, adequate animal performance may be possible if offered enough leaf biomass at pasture. The aim of this experiment was to evaluate the potential of milk production with these two forage species

    Effectiveness of 0.05% oxymetazoline (Vicks Sinex Micromist) nasal spray in the treatment of objective nasal congestion demonstrated to 12h post-administration by magnetic resonance imaging

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    Introduction: This study aimed to assess the qualitative and quantitative utility of MRI imaging to illustrate the magnitude and duration of the effect of a standard 100 μg dose of oxymetazoline in a commercially available formulation that also contains aromatic oils. Methods: This was a randomized, open label, single dose, parallel group study in 21 adult male and female subjects who reported moderate to severe nasal congestion due to acute upper respiratory tract infection or hay fever. MRI scans were acquired using a 3T Philips Achieva scanner with a 16 channel head receive coil. High resolution MRI scans of the nasal turbinates were obtained immediately prior to dosing (baseline) and at approximately 1, 8, 10, 11, and 12 hours after dosing. The efficacy variables of primary interest were inferior turbinate total volume at 8 and 12 hours post-dosing. The secondary efficacy variables analysed were inferior turbinate total volume at 1, 10, and 11 hours post-dosing, middle turbinate total volume at 1, 8, 10, 11, and 12 hours post-dosing. Results: Changes from baseline volumes measured for the inferior and middle turbinates of subjects receiving the oxymetazoline formulation showed significant (P<0.05) decreases at all times up to and including 12 hours post-administration. No significant decreases from baseline were detected in subjects receiving a sham ‘spray’ (untreated control - spray bottles with no spray solution). Statistical ANCOVA results of inferior and middle turbinate volume indicated significant differences (P<0.05) at all measurement points up to and including 12 hours post-administration between the oxymetazoline treatment group and the untreated control with the only exception the middle turbinate volume at 10 hours (P=0.0896). The significant changes were likely to be clinically relevant though this was not measured in the study. No AEs were reported during this study and no other safety evaluations were made. Conclusions: This study showed that MRI assessment of nasal congestion in human volunteers is a robust, repeatable and viable measurement technique. The application of a 100 µg Vicks Sinex Micromist® nasal decongestant (0.05% oxymetazoline solution) delivered a highly significant reduction in inferior and middle turbinate volumes compared with the application of a control, measurable by the MRI method up to and including a 12 hour post-dose scan

    Farelo de soja geneticamente modificado é equivalente aos demais farelo de soja convencionais utilizados em rações para frangos de corte.

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    Com este estudo objetivou-se avaliar o desempenho de frangos de corte alimentados com ração contendo farelo de soja evento CV127, geneticamente modificada, tolerante aos herbicidas do grupo químico das Imidazolinonas, tendo como testemunhas os farelos de soja convencionais CONQUISTA, MONSOY 8001 e COODETEC 217

    Magnetic-field-induced singularities in spin dependent tunneling through InAs quantum dots

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    Current steps attributed to resonant tunneling through individual InAs quantum dots embedded in a GaAs-AlAs-GaAs tunneling device are investigated experimentally in magnetic fields up to 28 T. The steps evolve into strongly enhanced current peaks in high fields. This can be understood as a field-induced Fermi-edge singularity due to the Coulomb interaction between the tunneling electron on the quantum dot and the partly spin polarized Fermi sea in the Landau quantized three-dimensional emitter.Comment: 5 pages, 4 figure
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