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1.
We compare two models for the analysis of repeated ordinal categorical data: the classical parametric model for means of scores assigned to the categories of the response variable and a nonparametric model based on relative effects derived from the marginal distribution functions of the response. An example in the field of Dentistry is used to illustrate and to compare the models. We also consider a simulation study to evaluate the type‐I error rates and the power of tests under both models in a balanced design setup. The simulation results suggest that both approaches behave similarly for equally spaced scores but may perform differently otherwise. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
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Summary Microorganisms which produce strong raw-starch degrading enzymes were isolated from soil using a medium containing a unique carbon source, -amylase resistant starch (-RS), which is insoluble in water and hardly digested with Bacillus amyloliquefaciens -amylase. Among the isolates, three strains showing high activities were characterized. Two of them, K-27 (fungus) and K-28 (yeast), produced -amylase and glucoamylase, and the final product from starch was only glucose. The third strain, K-2, was a bacterium and produced -amylase, which produced glucose and malto-oligosaccharides from starch. The enzyme preparation of these strains degraded raw corn starch rapidly.  相似文献   
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Abstract: The cis elements mediating activation of the tyrosine hydroxylase gene by angiotensin II were examined by transfecting tyrosine hydroxylase promoter-luciferase constructs into cultured bovine adrenal medullary cells. Angiotensin II-responsive elements are located within −54/+25-bp and −269/−55-bp promoter regions and were identified, respectively, as cyclic AMP (CRE)- and 12- O -tetradecanoylphorbol 13-acetate responsive element (TRE)-like sequences. Unlike CRE, TRE also supports basal promoter activity. Mutations of TRE or CRE that reduced angiotensin II stimulation abolished in vitro binding of nuclear proteins to those elements, suggesting that proteins forming CRE- and TRE-inducible complexes may mediate angiotensin II stimulation. The TRE is adjacent to a dyad symmetry element. Those two sites form a common regulatory unit in which the dyad symmetry element acts as a repressor of the TRE site. Isolated dyad symmetry element did not bind nuclear proteins in vitro. In supercoiled DNA it exhibited S1 nuclease sensitivity and was recognized by a DNA cruciform-specific antibody consistent with the extrusion of a cruciform structure that overlaps with the TRE. A mutation that abolished formation of the cruciform correlated with a loss of repressor activity. We propose a novel model of tyrosine hydroxylase gene regulation in which functions of the TRE are modulated via structural transition in the adjacent DNA.  相似文献   
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The physical and chemical environment, and the phytoplankton primary production of southeastern Brazil were studied in relation to the general oceanographic structure during two research cruises (winter and summer). In each cruise, a total of 91 stations were occupied. Data were collected on the spatial distribution of nutrients, phytoplankton biomass and photosynthetic capacity over the coastal, shelf and oceanic areas off São Paulo, Paraná and Santa Catarina States.During wintertime, the mixing processes between tropical warm waters of the Brazil Current and subantarctic waters of the Malvinas Current formed strong environmental gradients. The drainings of Rio de La Plata and Lagoa dos Patos are transported northwards by coastal currents, enriching the shelf waters off Santa Catarina State with inorganic nutrients and consequently increasing the chlorophyll a to the highest concentrations (> 3.5 mg m –3) measured during the two cruises. In slope waters chlorophyll values were always low (0.05–0.45 mg m –3). The chlorophyll within the euphotic layer varied from 8.8–36.7 and 1.2–18.5 mg m–2 during winter and summer, respectively.The surface photosynthetic rates during winter and summer cruises ranged respectively from 0.21–9.17 and 0.66–19.60 mgC/mgChl.a/h. The mean rates were higher in nearshore waters and decreased seaward.The thermal structure of the water column affected the vertical distribution of chlorophyll a and photosynthesis within the euphotic zone; During unstratified periods (winter) they were uniformly distributed but the occurrence of subsurface peaks of chlorophyll and strong photosynthetic inhibition of low light adapted cells in deeper layers are associated to the seasonal thermocline. Occasionally, upwelling of deep waters from shelf break enriched the deeper euphotic layers in offshore areas. Intensive upwelling was observed off Paranagua Bay (Parana State) and the mechanisms of its formation are discussed.  相似文献   
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Exercise training has demonstrated cardioprotection effects. However, the exact mechanism behind this effect is not is clear. The present study evaluated the effects of 12 weeks of previous treadmill training on the levels of oxidative damage, antioxidant enzyme activity and injury in the myocardium of rats submitted to infarction induced by isoproterenol (ISO). Isoproterenol treatment (80 mg/kg given over 2 days in two equal doses) caused arrhythmias and 60% mortality within 24 h of the last injection in the control group (C + ISO) group when compared with the saline control group (saline). Creatine Kinase ? MB levels were markedly increased in hearts from ISO-treated animals in the C + ISO group. Twelve weeks of treadmill training reduced superoxide production, lipid peroxidation levels and protein carbonylation in these animals, as well as increasing the activities and expressions of SOD and CAT. Previous training also reduced CK-MB levels and numbers of deaths by 40%, preventing the deleterious effects of ISO. Based on the data obtained in this study, it is suggested that 12-week treadmill training increases antioxidant enzymes, decreases oxidative damage and reduces the degree of infarction induced by ISO in the hearts of male rats.  相似文献   
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Endemic and endangered species are highly vulnerable to habitat perturbations and may be subject to variations in their population size. Management plan for these species is crucial to avoid population decline, loss of genetic variability, inbreeding and ultimately extinction. The sand lizard, Liolaemus lutzae, is endemic to a habitat of sandy coastal plain (restinga). Its geographical distribution extends for only 200 km stretch of the coast of Rio de Janeiro state, Brazil, one of South America’s most densely populated regions. Extensive development and degradation of the beaches where the species inhabits, have led to the species becoming critically endangered. We used mitochondrial DNA sequences and microsatellite loci to resolve patterns of population connectivity and genetic variation within the species in order to provide a platform for a species management plan. Our results indicate the existence of three main populations, separated from each other by the Guanabara Bay and by the Arraial do Cabo Peninsula. The low microsatellite genetic variation and heterozygosity witnessed in each of the three populations, together with high levels of inbreeding and low effective population sizes suggest that the species is in urgent need of intensive management. Based on the results of this study we propose strong measures to protect existing restinga fragments and the implementation of programmes of captive breeding and reintroduction of individuals from the heavily threatened regions to protected refugia. Such measures may be the only way of ensuring the continuity of the species.  相似文献   
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Leprosy is an infectious and contagious spectral disease accompanied by a series of immunological events triggered by the host response to the aetiologic agent, Mycobacterium leprae . The induction and maintenance of the immune/inflammatory response in leprosy are linked to multiple cell interactions and soluble factors, primarily through the action of cytokines. The purpose of the present study was to evaluate the serum levels of tumour necrosis factor (TNF)-α and its soluble receptors (sTNF-R1 and sTNF-R2) in leprosy patients at different stages of multidrug treatment (MDT) in comparison with non-infected individuals and to determine their role as putative biomarkers of the severity of leprosy or the treatment response. ELISA was used to measure the levels of these molecules in 30 healthy controls and 37 leprosy patients at the time of diagnosis and during and after MDT. Our results showed increases in the serum levels of TNF-α and sTNF-R2 in infected individuals in comparison with controls. The levels of TNF-α, but not sTNF-R2, decreased with treatment. The current results corroborate previous reports of elevated serum levels of TNF-α in leprosy and suggest a role for sTNF-R2 in the control of this cytokine during MDT.  相似文献   
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