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171.
Compositional alteration of the gut microbiota is associated with ulcerative colitis (UC). Here, a model culture system is established for the in vitro human colonic microbiota of UC, which will be helpful for determining medical interventions. 16S ribosomal RNA sequencing confirms that UC models are successfully developed from fecal inoculum and retain the bacterial species biodiversity of UC feces. The UC models closely reproduce the microbial components and successfully preserve distinct clusters from the healthy subjects (HS), as observed in the feces. The relative abundance of bacteria belonging to the family Lachnospiraceae significantly decreases in the UC models compared to that in HS, as observed in the feces. The system detects significantly lower butyrogenesis in the UC models than that in HS, correlating with the decreased abundance of Lachnospiraceae. Interestingly, the relative abundance of Lachnospiraceae does not correlate with disease activity (defined as partial Mayo score), suggesting that Lachnospiraceae persists in UC patients at a decreased level, irrespective of the alteration in disease activity. Moreover, the system shows that administration of Clostridium butyricum MIYAIRI restores butyrogenesis in the UC model. Hence, the model detects deregulation in the intestinal environment in UC patients and may be useful for simulating the effect of probiotics.  相似文献   
172.
Spatial genetic structure (SGS) of plants mainly depends on the effective population size and gene dispersal. Maternally inherited loci are expected to have higher genetic differentiation between populations and more intensive SGS within populations than biparentally inherited loci because of smaller effective population sizes and fewer opportunities of gene dispersal in the maternally inherited loci. We investigated biparentally inherited nuclear genotypes and maternally inherited chloroplast haplotypes of microsatellites in 17 tree populations of three wild cherry species under different conditions of tree distribution and seed dispersal. As expected, interpopulation genetic differentiation was 6–9 times higher in chloroplast haplotypes than in nuclear genotypes. This difference indicated that pollen flow 4–7 times exceeded seed flow between populations. However, no difference between nuclear and chloroplast loci was detected in within‐population SGS intensity due to their substantial variation among the populations. The SGS intensity tended to increase as trees became more aggregated, suggesting that tree aggregation biased pollen and seed dispersal distances toward shorter. The loss of effective seed dispersers, Asian black bears, did not affect the SGS intensity probably because of mitigation of the bear loss by other vertebrate dispersers and too few tree generations after the bear loss to alter SGS. The findings suggest that SGS is more variable in smaller spatial scales due to various ecological factors in local populations.  相似文献   
173.
During craniofacial development, Meckel's cartilage and the mandible bone derive from the first branchial arch, and their development depends upon the contribution of cranial neural crest (CNC) cells. We previously demonstrated that conditional inactivation of Tgfbr2 in the neural crest of mice (Tgfbr2fl/fl;Wnt1-Cre) results in severe defects in mandibular development, although the specific cellular and molecular mechanisms by which TGF-β signaling regulates the fate of CNC cells during mandibular development remain unknown. We show here that loss of Tgfbr2 does not affect the migration of CNC cells during mandibular development. TGF-β signaling is specifically required for cell proliferation in Meckel's cartilage and the mandibular anlagen and for the formation of the coronoid, condyle and angular processes. TGF-β-mediated connective tissue growth factor (CTGF) signaling is critical for CNC cell proliferation. Exogenous CTGF rescues the cell proliferation defect in Meckel's cartilage of Tgfbr2fl/fl;Wnt1-Cre mutants, demonstrating the biological significance of this signaling cascade in chondrogenesis during mandibular development. Furthermore, TGF-β signaling controls Msx1 expression to regulate mandibular osteogenesis as Msx1 expression is significantly reduced in Tgfbr2fl/fl;Wnt1-Cre mutants. Collectively, our data suggest that there are differential signal cascades in response to TGF-β to control chondrogenesis and osteogenesis during mandibular development.  相似文献   
174.
gamma-Secretase is an atypical aspartyl protease that cleaves amyloid beta-precursor protein to generate Abeta peptides that are causative for Alzheimer disease. gamma-Secretase is a multimeric membrane protein complex composed of presenilin (PS), nicastrin, Aph-1, and Pen-2. Pen-2 directly binds to transmembrane domain 4 of PS and confers proteolytic activity on gamma-secretase, although the mechanism of activation and its role in catalysis remain unknown. Here we show that an addition of amino acid residues to the N terminus of Pen-2 specifically increases the generation of Abeta42, the longer and more aggregable species of Abeta. The effect of the N-terminal elongation of Pen-2 on Abeta42 generation was independent of the amino acid sequences, the expression system and the presenilin species. In vitro gamma-secretase assay revealed that Pen-2 directly affects the Abeta42-generating activity of gamma-secretase. The elongation of Pen-2 N terminus caused a reduction in the water accessibility of the luminal side of the catalytic pore of PS1 in a similar manner to that caused by an Abeta42-raising gamma-secretase modulator, fenofibrate, as determined by substituted cysteine accessibility method. These data suggest a unique mechanism of Abeta42 overproduction associated with structural changes in the catalytic pore of presenilins caused commonly by the N-terminal elongation of Pen-2 and fenofibrate.  相似文献   
175.

Background  

The construct validity of alexithymia and its assessment using the 20-item Toronto Alexithymia Scale (TAS-20) in Japan is unknown. Low reliability has been found for the third factor of the TAS-20 in some cultures, and the factor structure for psychosomatic disorder patients has not been adequately investigated. Although alexithymia most likely has certain developmental aspects, this has infrequently been investigated.  相似文献   
176.
Previous studies have indicated that lipopolysaccharide(LPS)from Gram-negative bacteria inplaque induces the release of prostaglandin E_2(PGE_2),which promotes alveolar bone resorption in periodontitis,and that tobacco smoking might be an important risk factor for the development and severity of periodontitis.We determined the effect of nicotine and LPS on alkaline phosphatase(ALPase)activity,PGE_2 production,and the expression of cyclooxygenase(COX-1,COX-2),PGE_2 receptors Ep1-4,and macrophage colonystimulating factor(M-CSF)in human osteoblastic Saos-2 cells.The cells were cultured with 10~(-3)M nicotinein the presence of 0,1,or 10μg/ml LPS,or with LPS alone.ALPase activity decreased in cells cultured withnicotine or LPS alone,and decreased further in those cultured with both nicotine and LPS,whereas PGE_2production significantly increased in the former and increased further in the latter.By itself,nicotine did notaffect expression of COX-1,COX-2,any of the PGE_2 receptors,or M-CSF,but when both nicotine and LPSwere present,expression of COX-2,Ep3,Ep4,and M-CSF increased significantly.Simultaneous addition of10~(-4)M indomethacin eliminated the effects of nicotine and LPS on ALPase activity,PGE_2 production,and M-CSF expression.Phosphorylation of protein kinase A was high in cells cultured with nicotine and LPS.Theseresults suggest that LPS enhances the production of nicotine-induced PGE_2 by an increase in COX-2 expres-sion in osteoblasts,that nicotine-LPS-induced PGE_2 interacts with the osteoblast Ep4 receptor primarily inautocrine or paracrine mode,and that the nicotine-LPS-induced PGE_2 then decreases ALPase activity andincreases M-CSF expression.  相似文献   
177.
Personalized medicine allows the selection of treatments best suited to an individual patient and disease phenotype. To implement personalized medicine, effective tests predictive of response to treatment or susceptibility to adverse events are needed, and to develop a personalized medicine test, both high quality samples and reliable data are required. We review key features of state-of-the-art proteomic profiling and introduce further analytic developments to build a proteomic toolkit for use in personalized medicine approaches. The combination of novel analytical approaches in proteomic data generation, alignment and comparison permit translation of identified biomarkers into practical assays. We further propose an expanded statistical analysis to understand the sources of variability between individuals in terms of both protein expression and clinical variables and utilize this understanding in a predictive test.  相似文献   
178.
Here, we developed a novel in vitro co-culture model, in which process-bearing astrocytes and isolated cerebral microvessels from mice were co-cultured. Astrocytes formed contacts with microvessels from both adult and neonatal mice. However, concentrated localization of the immunofluorescence signal for aquaporin-4 (AQP4) at contact sites between perivascular endfoot processes and blood vessels was only detected with neonatal mouse microvessels. Contact between astrocytic processes and microvessels was retained, whereas concentrated localization of AQP4 signal at contact sites was lost, by knockdown of dystroglycan or α-syntrophin, reflecting polarized localization of AQP4 at perivascular regions in the brain. Further, using our in vitro co-culture model, we found that astrocytes predominantly extend processes to pericytes located at the abluminal surface of microvessels, providing additional evidence that this model is representative of the in vivo situation. Altogether, we have developed a novel in vitro co-culture model that can reproduce aspects of the in vivo situation and is useful for assessing contact formation between astrocytes and blood vessels.  相似文献   
179.
Mice carrying two t complementary haplotypes (tw5/tw32) are totally sterile. Their spermatozoa have poor motility and fertilize neither zone-intact nor zona-free oocytes, even though they are structurally indistinguishable from control (wild-type) spermatozoa. However, when injected directly into oocytes, these infertile spermatozoa are able to participate in normal development. This suggests that infertility of tw5/tw32 male (spermatozoa) is more likely to be due to poor sperm-oocyte interaction than to genetic incompetence of sperm nuclei. © 1996 Wiley-Liss, Inc.  相似文献   
180.
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