984 resultados para 312.272
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A series of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acids (DOAA) which are known to be anti-inflammatory agents were studied. The geometries of some of the molecules obtained from X-ray crystallography were used in the calculations as such while the geometries of their derivatives were obtained by local, partial geometry optimization around the Sites of substitution employing the AMI method, keeping the remaining parts of the geometries the same as those in the parent molecules. Molecular electrostatic potential (MEP) mapping was performed for the molecules using optimized hybridization displacement charges (HDC) combined with Lowdin charges, as this charge distribution has been shown earlier to yield near ab initio quality results. A good correlation has been found between the MEP values near the oxygen atoms of the hydroxyl groups of the carboxy groups of the molecules and their anti-inflammatory activities. The result is broadly in agreement with the model proposed earlier by other authors regarding the structure-activity relationship for other similar molecules.
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C15H22N204.H20 , Mr= 312.37, monoclinic,P21, a=5.577(2), b=8.686(2), c= 16.228 (2) A,fl=92.63(2) ° , V=785(1)A 3, Z=2, O =1.34,Dx= 1.32Mgm -3, CuKa, 2= 1.54184'~, /2=0.78 mm -I, F(000) = 320, T= 293 K. The final R value for 1607 observed reflections ll,,>_3tr(l,,)l is 0.039. The terminal N 1 is protonated and the dipeptide exists as a zwitterion. The crystal structure is stabilized by extensive hydrogen-bonding interactions involving N and O atoms, with N...O in the range 2.65 (1)-2.95 (1) ,/~ and O...O in the range 2.60 (1)-2.78 (1) A.
Improving outcome of childhood bacterial meningitis by simplified treatment : Experience from Angola
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Background Acute bacterial meningitis (BM) continues to be an important cause of childhood mortality and morbidity, especially in developing countries. Prognostic scales and the identification of risk factors for adverse outcome both aid in assessing disease severity. New antimicrobial agents or adjunctive treatments - except for oral glycerol - have essentially failed to improve BM prognosis. A retrospective observational analysis found paracetamol beneficial in adult bacteraemic patients, and some experts recommend slow β-lactam infusion. We examined these treatments in a prospective, double-blind, placebo-controlled clinical trial. Patients and methods A retrospective analysis included 555 children treated for BM in 2004 in the infectious disease ward of the Paediatric Hospital of Luanda, Angola. Our prospective study randomised 723 children into four groups, to receive a combination of cefotaxime infusion or boluses every 6 hours for the first 24 hours and oral paracetamol or placebo for 48 hours. The primary endpoints were 1) death or severe neurological sequelae (SeNeSe), and 2) deafness. Results In the retrospective study, the mortality of children with blood transfusion was 23% (30 of 128) vs. without blood transfusion 39% (109 of 282; p=0.004). In the prospective study, 272 (38%) of the children died. Of those 451 surviving, 68 (15%) showed SeNeSe, and 12% (45 of 374) were deaf. Whereas no difference between treatment groups was observable in primary endpoints, the early mortality in the infusion-paracetamol group was lower, with the difference (Fisher s exact test) from the other groups at 24, 48, and 72 hours being significant (p=0.041, 0.0005, and 0.005, respectively). Prognostic factors for adverse outcomes were impaired consciousness, dyspnoea, seizures, delayed presentation, and absence of electricity at home (Simple Luanda Scale, SLS); the Bayesian Luanda Scale (BLS) also included abnormally low or high blood glucose. Conclusions New studies concerning the possible beneficial effect of blood transfusion, and concerning longer treatment with cefotaxime infusion and oral paracetamol, and a study to validate our simple prognostic scales are warranted.
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Mechanical joints in composites can be tailored to achieve improved performance and better life by appropriately selecting the laminate parameters. In order to gain the best advantage of this possibility of tailoring the laminate, it is necessary to understand the influence of laminate parameters on the behaviour of joints in composites. Most of the earlier studies in this direction were based on simplified assumptions regarding load transfer at the pin-plate interface and such studies were only carried out on orthotropic and quasi-isotropic laminates. In the present study, a more rigorous analysis is carried out to study pin joints in laminates with anisotropic properties. Two types of laminates with (0/ + ?4/90)s and (0/ ± ?2/90)s layups made out of graphite epoxy T300/5208 material system are considered. The analysis mainly concentrates on clearance fit in which the pin is of smaller diameter compared to the hole. The main aspect of the analysis of pin joints is the changing contact between the pin and the plate with increasing load levels. The analysis is carried out by an iterative finite element technique and a computationally efficient routine is developed for this purpose. Numerical studies indicate that the location and magnitude of the peak stresses along the hole boundary are functions of fibre angle and the overall anisotropic properties. It is also shown that the conventional assumption of cosine distribution for the contact pressure between pin and the plate in the analysis lead to underestimation of bearing failure load and overestimation of shear and tensile failure loads in typical (0/905)s cross-ply laminates.
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XVIII IUFRO World Congress, Ljubljana 1986.
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The mechanism underlying homeostatic regulation of the plasma levels of free retinol-binding protein and free thyroxine, the systemic distribution of which is of great importance, has been investigated. A simple method has been developed to determine the rate of dissociation of a ligand from the binding protein. Analysis of the dissociation process of retinol-binding protein from prealbumin-2 reveals that the free retinol-binding protein pool undergoes massive flux, and the prealbumin-2 participates in homeostatic regulation of the free retinol-binding protein pool. Studies on the dissociation process of thyroxine from its plasma carrier proteins show that the various plasma carrier proteins share two roles. Of the two types of protein, the thyroxine-binding globulin (the high affinity binding protein) contributes only 27% of the free thyroxine in a rapid transition process, despite its being the major binding protein. But prealbumin-2, which has lower affinity towards thyroxine, participates mainly in a rapid flux of the free thyroxine pool. Thus thyroxine-binding globulin acts predominantly as a plasma reservoir of thyroxine, and also probably in the �buffering� action on plasma free thyroxine level, in the long term, while prealbumin-2 participates mainly in the maintainance of constancy of free thyroxine levels even in the short term. The existence of these two types of binding protein facilitates compensation for the metabolic flux of the free ligand and maintenance of the thyroxine pool within a very narrow range.
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To accurately assess the impact of anthropogenic aerosols on climate, spatial and temporal distribution of its radiative properties is essential. The first step towards separating the radiative impact of natural aerosol from its anthropogenic counterparts is to gather information on natural aerosols. In this paper, we have used data from multiple satellites to derive the anthropogenic aerosol fraction (AAF) over the Afro-Asian region. The AAF was largest during the pre-monsoon season (May-June) and lowest during winter. We have shown that over desert locations the AAF was unexpectedly large (>0.4) and the regionally (and annually) averaged anthropogenic fraction over the Afro-Asian region was 0.54 +/- 0.12. Copyright (C) 2010 Royal Meteorological Society
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Microwave irradiation, using a commercial microwave oven accelerates (in 10–15 min) the three-step ortho ester Claisen rearrangement of allyl and propynyl alcohols in dry DMF in open Erlenmeyer flasks.
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The dissertation discusses the conceptions of place and landscape amongst Nenets living on the island of Kolguyev or being of Kolguyev descent. The conceptions are examined through the everyday life of the community, oral recollections and narration that unfold meanings related to the island. The research material has been collected in ethnographic fieldwork in 2000 2005. The duration of individual fieldworks varies from two weeks to three months and their total duration is nearly six months. The fieldwork has been conducted both on the island and in the city of Nar yan-Mar. The main methods have been participant observation and recorded and unrecorded informal interviews. In addition to the field work data, archive materials, travel accounts, and other historical texts by outsiders about Kolguyev or the Nenets living in the European side of Russia have been used as a research material. The analysis is based on the idea of the place as a meeting point of the physical features, experiences in them and collective narration about them. The concept sense of place is used to describe the interaction of these three. Lived space manifests individual s or collective sense of place. The places form different kinds of networks of meanings which are called landscapes. Hot spots are places where different meanings accumulate. Furthermore, the material is analysed using the concepts of Tale World and Story Realm by Katherine Young. The Tale World is a realm created during the Story Realm, i.e. the event of narrations. The Tale Worlds are true as such but become evaluated in the Story Realm. The Tale Worlds are seen to arise both from the physical features of a place and from oral tradition, but at the same time these worlds give meanings to the place. The Tale Worlds are one of the central ingredients for the sense of place. One of the most central hot spots in Kolguyev is the arok harbour, where most of the themes of the pre-Soviet Tale Worlds are placed: trade and interaction with the Russians, rituals of the popular religion and arrival of the first Nenets to the island. arok is also part of the landscape of the coast where the meetings of Nenets and the other(s) are generally connected. Furthermore, arok is connected to the network of amans graves but also more generally to the landscape of collective sacred and sacrificial places. Another hot spot is the population centre of Bugrino which unfolds through the evaluations of the Tale Worlds. It also is the centre of the everyday life of the community studied. The Tale Worlds of the radiant past fastens on the population centre which is described through the negative models within the genre of litany. Sacred places, that represent the possibility to meet the Otherworld or mark places were encounters with the Otherworld have taken place, generate many kinds of landscapes in the island. They fasten on the graves of the amans, sirtya tradition, and to collective sacred places with their associations. The networks are not closed systems but are given meanings and new associations continuously in narration and recollection. They form multi-level and significant landscapes which reflect the fastening of the Kolguyev Nenets in the tundra of the island. In the research material the holy places and the popular religiousness are emphasised which is one of the most significant research results. It can be seen to reflect collective resistance and the questioning of the atheistic propaganda of the Soviet years. The narration and the recollection often refer also to the discourse of the anti-religious propaganda or use its strategies. The centrality of the holy places is also based on the tenacity of the religious Tale Worlds and sense of place and to the collective significance of the religion in general.
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This thesis critically examines the patterns and processes of ethnic residential segregation in the Helsinki Metropolitan Area (HMA). These phenomena are examined in two main ways: a) between the native and immigrant populations and b) the extent to which different immigrant groups are sharing the same neighbourhoods. The main aim of the study is to test the extent to which the theoretical claims of the selective migration processes can explain the development of ethnic residential segregation in HMA. The data is mixed: it consists of neighbourhood-level statistics related to the migration, demography and housing stock. The selective migration flows are analysed within and between neighbourhood-types, defined on the basis of the percentages of foreign-language-speakers. For contextual purposes, the study also includes fifteen expert interviews who work within the housing sector. Firstly, the results show that, from the early 2000s the patterns of ethnic residential segregation have strengthened while the differences between neighbourhoods have grown. On a more general level the HMA can be divided into two main areas: some eastern and north-eastern neighbourhoods that have experienced the rise of immigrant concentrations and; the northern, north-western and southern parts of the HMA, where the number and percentages of immigrants have remained relatively low. However, within the eastern and north-eastern neighbourhoods there are also discernable internal differences that reflect the income levels of the inhabitants and the type of housing stock. The results also show that, the existing immigrant concentrations are ethnically and culturally mixed and thus qualitatively different from China town and Little-Italy enclaves of single groups of immigrants. Secondly, the results show that there are clear signs of the selective migration processes of the native and immigrant populations which have resulted in the discernable development of ethnic residential segregation. Migration flows of the native population have gravitated towards neighbourhoods, where the percentage of immigrants is below the HMA average. This has resulted in significant migration losses for neighbourhoods with established and developing concentrations of immigrants. Meanwhile, migration of immigrants has been drawn to neighbourhoods where their percentages are above the HMA average. However, the results also point to clear differences in the migration and spatial patterns of different immigrant groups. The spatial selectivity of migration is, thus, more prominent amongst the native population than when compared with immigrants. Overall, the results indicate that the reproduction of the selective migration flows of the native and immigrant populations will largely determine HMA s future development of ethnic residential segregation.
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The analysis of steady laminar forced convection boundary layer of power-law non-Newtonian fluids on a continuously moving cylinder with the surface maintained at a uniform temperature or uniform heat flux is presented. Of interest were the effects of power-law viscosity index, transverse curvature, generalized Prandtl number and streamwise coordinate on the local Nusselt number as well as on the velocity and temperature profiles. The two thermal boundary conditions yield quite similar results. Comparison of the calculated results with available series expansion solutions for a Newtonian fluid shows a very good performance of the present numerical procedure.
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The optical bandgap and thermal diffusivity of Si10AsxTe90−x (10 ≤ x ≤ 50) and Si15AsxTe85−x (5 ≤ x ≤ 40) glasses have been measured using the photoacoustic technique. The anomalous behaviour observed in these properties at the mean coordination number left angle bracketrright-pointing angle bracket = 2.60 is interpreted by reference to the formation and development of a layered structure in these glasses.
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Differences in flower success patterns in two habitat types that differed drastically with respect to rainfall, tree density and species composition were studied at Mudumalai wildlife sanctuary, India. Observations on phenological patterns of two species, Cassia fistula and Gmelina arborea, were made from April 1988 through June 1990. Quantitative data on flower-fruit ratio, insect visitation rates, pollen grain per stigma and the number of fruits per tree were recorded. Data were also collected on the number of pollen deposited on the stigma after different types of bees visited the flower. The data suggested that only carpenter bees (Xylocopa spp) effect pollination in C. fistula. The differences in fruit-flower ratios were attributed to the differences in insect visitation rates to inflorescences between sites. The low pollen number per stigma and the resultant reduction in reproductive success in C. fistula are attributed to the competing species G. arborea receiving more visitations from pollinators in the wetter site. These results suggest that pollinator limitation is another constraint in reproductive success of plants.
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Sesbania mosaic virus (SeMV) is a single-stranded positive-sense RNA plant virus belonging to the genus Sobemovirus. The movement protein (MP) encoded by SeMV ORF1 showed no significant sequence similarity with MPs of other genera, but showed 32% identity with the MP of Southern bean mosaic virus within the Sobemovirus genus. With a view to understanding the mechanism of cell-to-cell movement in sobemoviruses, the SeMV MP gene was cloned, over-expressed in Escherichia coli and purified. Interaction of the recombinant MP with the native virus (NV) was investigated by ELISA and pull-down assays. It was observed that SeMV MP interacted with NV in a concentration- and pH-dependent manner. Analysis of N- and C-terminal deletion mutants of the MP showed that SeMV MP interacts with the NV through the N- terminal 49 amino acid segment. Yeast two-hybrid assays confirmed the in vitro observations, and suggested that SeMV might belong to the class of viruses that require MP and NV/coat protein for cell-to-cell movement.