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101.
Horton R Gibson R Coggill P Miretti M Allcock RJ Almeida J Forbes S Gilbert JG Halls K Harrow JL Hart E Howe K Jackson DK Palmer S Roberts AN Sims S Stewart CA Traherne JA Trevanion S Wilming L Rogers J de Jong PJ Elliott JF Sawcer S Todd JA Trowsdale J Beck S 《Immunogenetics》2008,60(1):1-18
The human major histocompatibility complex (MHC) is contained within about 4 Mb on the short arm of chromosome 6 and is recognised
as the most variable region in the human genome. The primary aim of the MHC Haplotype Project was to provide a comprehensively
annotated reference sequence of a single, human leukocyte antigen-homozygous MHC haplotype and to use it as a basis against
which variations could be assessed from seven other similarly homozygous cell lines, representative of the most common MHC
haplotypes in the European population. Comparison of the haplotype sequences, including four haplotypes not previously analysed,
resulted in the identification of >44,000 variations, both substitutions and indels (insertions and deletions), which have
been submitted to the dbSNP database. The gene annotation uncovered haplotype-specific differences and confirmed the presence
of more than 300 loci, including over 160 protein-coding genes. Combined analysis of the variation and annotation datasets
revealed 122 gene loci with coding substitutions of which 97 were non-synonymous. The haplotype (A3-B7-DR15; PGF cell line)
designated as the new MHC reference sequence, has been incorporated into the human genome assembly (NCBI35 and subsequent
builds), and constitutes the largest single-haplotype sequence of the human genome to date. The extensive variation and annotation
data derived from the analysis of seven further haplotypes have been made publicly available and provide a framework and resource
for future association studies of all MHC-associated diseases and transplant medicine.
Horton and Gibson contributed equally to this work. 相似文献
102.
Surface-layer protein extracts from Lactobacillus helveticus inhibit enterohaemorrhagic Escherichia coli O157:H7 adhesion to epithelial cells 总被引:2,自引:0,他引:2
Johnson-Henry KC Hagen KE Gordonpour M Tompkins TA Sherman PM 《Cellular microbiology》2007,9(2):356-367
Adherence of intestinal pathogens, including Escherichia coli O157:H7, to human intestinal epithelial cells is a key step in pathogenesis. Probiotic bacteria, including Lactobacillus helveticus R0052 inhibit the adhesion of E. coli O157:H7 to epithelial cells, a process which may be related to specific components of the bacterial surface. Surface-layer proteins (Slps) are located in a paracrystalline layer outside the bacterial cell wall and are thought to play a role in tissue adherence. However, the ability of S-layer protein extract derived from probiotic bacteria to block adherence of enteric pathogens has not been investigated. Human epithelial (HEp-2 and T84) cells were treated with S-layer protein extract alone, infected with E. coli O157:H7, or pretreated with S-layer protein extract prior to infection to determine their importance in the inhibition of pathogen adherence. The effects of S-layer protein extracts were characterized by phase-contrast and immunofluorescence microscopy and measurement of the transepithelial electrical resistance of polarized monolayers. Pre-treatment of host epithelial cells with S-layer protein extracts prior to E. coli O157:H7 infection decreased pathogen adherence and attaching-effacing lesions in addition to preserving the barrier function of monolayers. These in vitro studies indicate that a non-viable constituent derived from a probiotic strain may prove effective in interrupting the infectious process of an intestinal pathogen. 相似文献
103.
104.
Diel vertical migration of zooplankton in the Northeast Atlantic 总被引:7,自引:0,他引:7
Acoustic Doppler current profiler (ADCP) data collected duringAugustSeptember 1991 reveal the diel migration of zooplanktonin the northeast Atlantic (5060 相似文献
105.
Alireza Behjousiar Antony Constantinou Karen M. Polizzi Cleo Kontoravdi 《Journal of visualized experiments : JoVE》2014,(84)
In the era of computational biology, new high throughput experimental systems are necessary in order to populate and refine models so that they can be validated for predictive purposes. Ideally such systems would be low volume, which precludes sampling and destructive analyses when time course data are to be obtained. What is needed is an in situ monitoring tool which can report the necessary information in real-time and noninvasively. An interesting option is the use of fluorescent, protein-based in vivo biological sensors as reporters of intracellular concentrations. One particular class of in vivo biosensors that has found applications in metabolite quantification is based on Förster Resonance Energy Transfer (FRET) between two fluorescent proteins connected by a ligand binding domain. FRET integrated biological sensors (FIBS) are constitutively produced within the cell line, they have fast response times and their spectral characteristics change based on the concentration of metabolite within the cell. In this paper, the method for constructing Chinese hamster ovary (CHO) cell lines that constitutively express a FIBS for glucose and glutamine and calibrating the FIBS in vivo in batch cell culture in order to enable future quantification of intracellular metabolite concentration is described. Data from fed-batch CHO cell cultures demonstrates that the FIBS was able in each case to detect the resulting change in the intracellular concentration. Using the fluorescent signal from the FIBS and the previously constructed calibration curve, the intracellular concentration was accurately determined as confirmed by an independent enzymatic assay. 相似文献
106.
Rolland M Heckerman D Deng W Rousseau CM Coovadia H Bishop K Goulder PJ Walker BD Brander C Mullins JI 《PloS one》2008,3(1):e1424
Background
HLA class-I alleles differ in their ability to control HIV replication through cell-mediated immune responses. No consistent associations have been found between the breadth of Cytotoxic T Lymphocytes (CTL) responses and the control of HIV-1, and it is unknown whether the size or distribution of the viral proteome-wide epitope repertoire, i.e., the intrinsic ability to present fewer, more or specific viral epitopes, could affect clinical markers of disease progression.Methodology/Principal Findings
We used an epitope prediction model to identify all epitope motifs in a set of 302 HIV-1 full-length proteomes according to each individual''s HLA (Human Leukocyte Antigen) genotype. The epitope repertoire, i.e., the number of predicted epitopes per HIV-1 proteome, varied considerably between HLA alleles and thus among individual proteomes. In a subgroup of 270 chronically infected individuals, we found that lower viral loads and higher CD4 counts were associated with a larger predicted epitope repertoire. Additionally, in Gag and Rev only, more epitopes were restricted by alleles associated with low viral loads than by alleles associated with higher viral loads.Conclusions/Significance
This comprehensive analysis puts forth the epitope repertoire as a mechanistic component of the multi-faceted HIV-specific CTL response. The favorable impact on markers of disease status of the propensity to present more HLA binding peptides and specific proteins gives impetus to vaccine design strategies that seek to elicit responses to a broad array of HIV-1 epitopes, and suggest a particular focus on Gag. 相似文献107.
Laminin (LN), an extracellular matrix component, is a key factor in promoting axonal regeneration, coordinately regulating growth in conjunction with trophic signals provided by the neurotrophins, including nerve growth factor (NGF). This study investigated potential interactions between the LN and NGF-mediated signaling pathways in PC12 cells and primary neurons. Neurite outgrowth stimulated by NGF was enhanced on a LN substrate. Western blot analysis of pertinent signal transduction components revealed both enhanced phosphorylation of early signaling intermediates upon co-stimulation, and a LN-induced down-regulation of p75NTR which could be prevented by the addition of integrin inhibitory arginine-glycine-aspartate (RGD) peptides. This p75NTR down-regulation was associated with a LN-mediated up-regulation of PTEN and resulted in a decrease in Rho activity. Studies using over-expression or siRNA-mediated knock-down of PTEN demonstrate a consistent inverse relationship with p75NTR, and the over-expression of p75NTR impaired neurite outgrowth on a LN substrate, as well as resulting in sustained activation of Rho which is inhibitory to neurite outgrowth. p75NTR is documented for its role in the transduction of inhibitory myelin-derived signals, and our results point to extracellular matrix regulation of p75NTR as a potential mechanism to ameliorate inhibitory signaling leading to optimized neurite outgrowth. 相似文献
108.
The tumour suppressor gene BRCA1 encodes a 220 kDa protein that participates in multiple cellular processes. The BRCA1 protein contains a tandem of two BRCT repeats at its carboxy-terminal region. The majority of disease-associated BRCA1 mutations affect this region and provide to the BRCT repeats a central role in the BRCA1 tumour suppressor function. The BRCT repeats have been shown to mediate phospho-dependant protein-protein interactions. They recognize phosphorylated peptides using a recognition groove that spans both BRCT repeats. We previously identified an interaction between the tandem of BRCA1 BRCT repeats and ACCA, which was disrupted by germ line BRCA1 mutations that affect the BRCT repeats. We recently showed that BRCA1 modulates ACCA activity through its phospho-dependent binding to ACCA. To delineate the region of ACCA that is crucial for the regulation of its activity by BRCA1, we searched for potential phosphorylation sites in the ACCA sequence that might be recognized by the BRCA1 BRCT repeats. Using sequence analysis and structure modelling, we proposed the Ser1263 residue as the most favourable candidate among six residues, for recognition by the BRCA1 BRCT repeats. Using experimental approaches, such as GST pull-down assay with Bosc cells, we clearly showed that phosphorylation of only Ser1263 was essential for the interaction of ACCA with the BRCT repeats. We finally demonstrated by immunoprecipitation of ACCA in cells, that the whole BRCA1 protein interacts with ACCA when phosphorylated on Ser1263. 相似文献
109.
Focused glycomic analysis of the N-linked glycan biosynthetic pathway in ovarian cancer 总被引:1,自引:0,他引:1
Abbott KL Nairn AV Hall EM Horton MB McDonald JF Moremen KW Dinulescu DM Pierce M 《Proteomics》2008,8(16):3210-3220
110.
Karen Molyneux Barbra J. Starman Peter H. Byers Raymond Dalgleish 《Human genetics》1993,90(6):621-628
RNase A protection analysis was used in the search for the cause of a non-lethal osteogenesis imperfecta (OI) phenotype (Sillence type III). Cleavage of the hybrid formed between a normal 2(I) sequence and RNA isolated from the patient indicated the presence of a mismatch. The position of the mismatch was determined and the corresponding area of COL1A2 was amplified using the polymerase chain reaction. Sequencing of cloned amplified DNA revealed the deletion, which was not present in either parent, of the final three bases of exon 19 in one of the patient's two COL1A2 alleles. The deletion results in the loss of amino acid 255 (a valine encoded by the last codon of exon 19) of the triple helical region of half of the 2(I) collagen chains but does not disrupt the splicing of the heterogeneous nuclear RNA (hnRNA). This provides further evidence that OI type III may result from autosomal dominant mutations rather than only from autosomal recessive mutations as had previously been believed. 相似文献