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71.
The synaptosomal effluxes of D-aspartate and gamma-aminobutyric acid (GABA) induced by a substitution of the Cl- ions with propionate in the incubation medium were measured in preparations of hippocampal tissue homogenates. The efflux of aspartate was significantly higher than spontaneous efflux at 125 mM Cl- (normal = 144 mM) and was increased with decreasing Cl- concentration. GABA efflux was much less sensitive to a reduction in Cl- concentration than D-aspartate. The efflux was Ca2+-dependent in both cases.  相似文献   
72.
73.
Hydrobiologia - By hindering migration and inducing direct turbine mortality during downstream migration, hydropower is regarded as one of the most serious threats to anadromous salmonids. Yet,...  相似文献   
74.
The Chrysididae are a group of cleptoparasitic and parasitoid aculeate wasps with a large number of rare and endangered species. The taxonomy of this group has long been confusing due to the similarity of species and extensive intraspecific variation. We present for the first time a comprehensive dichotomous key for all 74 species found in the Nordic and Baltic countries. In addition to diagnostic characters, information on the distribution and biology of each species is also presented. A new species, Chrysis borealis Paukkunen, Ødegaard & Soon, sp. n. is described on the basis of specimens collected from Fennoscandia. Chrysis gracillima Förster, 1853 is recorded as new to the Nordic and Baltic countries.  相似文献   
75.
Immune reactions to citrulline-containing proteins appear to be central in the immunopathogenesis of rheumatoid arthritis. Citrulline residues are introduced into proteins by deimination of arginine residues, likely by an enzymatic process. There is a need to characterize which proteins in the inflamed joints of rheumatoid patients contain citrulline in situ. The characterization of deiminated proteins will be greatly facilitated by specific modification of peptide-bound citrulline residues that will enable specific enrichment and detection of citrulline-containing peptides. This study presents the details of such a modification method. The chemistry behind the reaction of the ureido group of citrulline with 2,3-butanedione in the presence of antipyrine is unraveled. Parameters for optimization of the reaction with respect to specificity and completeness, including the testing of different acids, reactant concentrations, and reaction time, are presented. This modification reaction is specific for citrulline residues. The modified product shows a characteristic mass shift of +238Da, as demonstrated by mass spectrometry. The product absorbs UV-Vis radiation at 464nm, and it is demonstrated that this can be used to selectively monitor citrulline-containing peptides during the separation of protein digests. Finally, the structure of the product of modified citrulline is solved by nuclear magnetic resonance spectroscopy using N-butylurea as a model substance. The results presented should facilitate the development of tags that can be used for the enrichment and subsequent detection of citrulline-containing protein fragments by mass spectrometry.  相似文献   
76.
Intervertebral disc calcification and herniation commonly affects Dachshund where the predisposition is caused by an early onset degenerative process resulting in disc calcification. A continuous spectrum of disc degeneration is seen within and among dog breeds, suggesting a multifactorial etiology. The number of calcified discs at 2 years of age determined by a radiographic evaluation is a good indicator of the severity of disc degeneration and thus serves as a measure for the risk of developing intervertebral disc herniation. The aim of the study was to identify genetic variants associated with intervertebral disc calcification in Dachshund through a genome-wide association (GWA) study. Based on thorough radiographic examinations, 48 cases with ≥ 6 disc calcifications or surgically treated for disc herniation and 46 controls with 0-1 disc calcifications were identified. GWA using the Illumina CanineHD BeadChip identified a locus on chromosome 12 from 36.8 to 38.6 Mb with 36 markers reaching genome-wide significance (P(genome) = 0.00001-0.026). This study suggests that a major locus on chromosome 12 harbors genetic variations affecting the development of intervertebral disc calcification in Dachshund.  相似文献   
77.
In recent decades, several animal and plant species have been in regression (population size decrease and geographical distribution shrinking). This loss of biodiversity can be due to various factors such as the destruction and fragmentation of habitat, urban development, pesticides or climate change. However, some species benefit from these changes and expand their distribution. Here we report observations (in 2013 and 2014) of two Euro-Mediterranean bumblebee species: Bombus terrestris for the first time and Bombus lapidarius, north of the Arctic Circle in Fennoscandia.  相似文献   
78.
Due to conservation needs, reliable rapid-assessment methods for mapping of biodiversity are needed. One approach is to use surrogates, i.e. quantities that correlate strongly with the number of species, but are easier to obtain. The purpose of this paper is to test two polychaete surrogates, one for higher taxa and one for indicator groups, that will facilitate prediction of species richness in marine soft-bottom communities. Soft sediment is an important habitat which covers most of the ocean bottom. Data on polychaetes from the North Atlantic were used since polychaetes are often numerically dominant in the benthic assemblages, both with regard to the number of species and their abundance. In the polychaete assemblages along the Norwegian coast, richness at the genus, family and order level were significantly, linearly correlated to total species richness (r 0.92). Polychaetes in the order Terebellida were found to be a good indicator of polychaete species richness and to a lesser extent also of whole benthic assemblages. The group Terebellida is potentially well suited as an indicator group, since it contains long-lived, large species that are easy to sort from the sediment and it is well defined taxonomically. Although promising as proxies for species richness in marine biodiversity studies, the use of lower taxonomic resolution and indicator groups requires further investigations in more local areas where there are conservation issues.  相似文献   
79.
The comparative advantages and disadvantages of intact antibodies and single-chain Fv as immunotoxins and radioimmunoconjugates have been widely discussed but not directly compared. In this study, the in vivo properties of anti-CD19 B43 monoclonal antibody and its derived single-chain Fv (FVS191) were studied in athymic nude mice bearing CD19-positive human lymphomas. B43 mab and FVS191 were labeled with iodine-125 using iodine-beads, and immunoreactivities were determined to be 57% and 72%, respectively. Scatchard analysis showed a similar high affinity for both. The results of pharmacokinetic studies revealed that FVS191 had a rapid biphasic clearance from the circulation (T1/2α = 2.5 min, T1/2β = 3.7 h); The T1/2α and T1/2β phases of B43 mab were determined to be 0.72 h and 57 h respectively. Biodistribution studies compared the uptake of labeled antibodies by CD19-positive and by CD19-negative tumors. The peak percentages of injected dose were 5.7% at 12 h for B43 and 2.45% at 1 h for FVS191. Radiolocalization indices (RI) demonstrated tumor-specific uptake for both, but higher uptake for B43. The optimal RI was seen at 15 min for FVS191 and 6 h for B43. FVS191 was unstable in vivo, approximately 50% of the injected dose being degraded in blood in 100 min. Radioactivity detected in the urine was present mainly as the deiodinized form of FVS191. The results suggest that B43 mab is favored over FVS191 in biodistribution properties and in vivo stability. Because B43 Mab showed early tumor-specific uptake, high RI values, and favorable tissue-to-blood ratios, it is a potential candidate for radioimmunotherapy and immunotoxin therapy of B-cell leukemia and lymphoma. Received: 17 June 1997 / Accepted: 17 June 1998  相似文献   
80.
Expression of surface-associated and secreted protein MopE of the methanotrophic bacterium Methylococcus capsulatus (Bath) in response to the concentration of copper ions in the growth medium was investigated. The level of protein associated with the cells and secreted to the medium changed when the copper concentration in the medium varied and was highest in cells exposed to copper stress.  相似文献   
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