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21.
The expression of cell adhesion molecules (CAMs) in the choroid plexus was studied in normal brain and during experimental autoimmune encephalomyelitis (EAE) in the SJL/J mouse during inflammation induced by intracerebral injection of killed Corynebacterium parvum in the C3H/He mouse. Both ICAM-1 and VCAM-1, but not MAdCAM-1, were constitutively expressed on choroid plexus epithelium but not on the fenestrated capillary endothelial cells within the choroid plexus. During EAE, we observed an up-regulation of ICAM-1 and VCAM-1 and de novo expression of MAdCAM-1 on choroid plexus epithelial cells. In contrast, endothelial cells in the choroid plexus were not induced to express any of the investigated CAMs. In in situ hybridization analysis we demonstrated that ICAM-1, VCAM-1, and MAdCAM-1 were locally synthesized and that the amount of their mRNAs increased in the inflamed choroid plexus. In vitro, primary choroid plexus epithelial cells could be induced to express ICAM-1, VCAM-1, and MAdCAM-1 on their surface after treatment with proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin-1, interferon-gamma, and lipopolysaccharide. To investigate the functional status of the expressed CAMs we performed Stamper-Woodruff binding assays on frozen sections of inflamed and naive brains. ICAM-1, VCAM-1, and MAdCAM-1 expressed in choroid plexus epithelial cells mediated binding of lymphocytes via their known ligands LFA-1 and alpha4-integrin, respectively. The expression of ICAM-1, VCAM-1, and MAdCAM-1 on choroid plexus epithelial cells together with the lack of their expression on the fenestrated choroid plexus endothelium raises the possibility that the epithelial blood-cerebrospinal-fluid barrier plays an important role in the immunosurveillance of the central nervous system.  相似文献   
22.
The magnetic flux normal to the scalp surface was measured with a whole-head neuromagnetometer while right-handed subjects (N = 15) were engaged in either an auditory word- or a tone-recognition task. Sources of the recorded magnetic fields were modeled as equivalent current dipoles at 4 ms intervals and the number of sources in the later portion of the magnetic response was used as an index of the degree of brain activation. Significantly more sources were found in the left as compared to the right hemisphere in the word but not the tone task on a group basis. On an individual basis, 13/15 subjects had more sources in the left as compared to the right hemisphere during the word task, while in the tone task 3/10 subjects showed this pattern. Sources of activity were found in the left superior and middle temporal gyri in all subjects with available MRI scans. Sources were also found in the supramarginal gyrus and in medial temporal areas, including the hippocampus, in the majority of cases. MEG appears to be a promising tool for detecting activity in cerebral areas specialized for language and memory function.  相似文献   
23.
This study was designed to determine whether the somatostatin analogue, octreotide, could prevent embryonic loss by normalizing increased uterine insulin-like growth factor-I (IGF-I) action related to hyperoestrogenaemia following superovulation. Superovulated immature and oestradiol-17beta-treated adult rats were infused with 100 or 300 microg/ml of octreotide respectively, or injected daily with 1 or 10 microg of octreotide from day 1 to day 3 of pregnancy. On day 3, embryos were collected from the oviducts and uteri. Uterine luminal fluid was subjected to embryo culture. The amounts of uterine IGF-I and IGF binding proteins (IGFBP) were determined by radioimmunoassay and ligand binding assay respectively. Octreotide infusion normalized uterine IGF-I action following superovulatory and oestradiol-17beta treatment, by reducing IGF-I concentrations and increasing IGFBP concentrations. Octreotide infusion increased the number of normal embryos by 2.7-fold and 1.7-fold in superovulated and oestradiol-17beta- treated rats respectively, and reversed the detrimental effects of uterine luminal fluid on embryonic development caused by superovulatory and oestradiol-17beta treatment. Daily injections with octreotide had similar but reduced effects in all parameters examined in both treatment groups. In conclusion, octreotide may reduce embryonic loss, at least in part, by normalizing IGF-I action following superovulation.   相似文献   
24.
BACKGROUND: The objective of this study was to determine the clinical and quality of life outcomes associated with adjunctive treatment of olanzapine added to either lithium or valproic acid/divalproex sodium in patients with bipolar disorder. METHODS: Patients with bipolar I disorder, were randomized to receive either olanzapine (5-20 mg) added to mood stabilizer therapy (n=224), or placebo added to mood stabilizer therapy (n=112) for 6 weeks. Changes in clinical outcomes over 6 weeks were measured by the Young Mania Rating Scale (Y-MRS) and the Hamilton Rating Scale for Depression (HAM-D). Quality of life was measured by the Lehman Brief Quality of Life Interview (QLI). RESULTS: Patients treated with olanzapine added to mood stabilizers, experienced significantly greater mean clinical improvements from baseline on both the Y-MRS and the HAM-D compared to those treated with placebo added to mood stabilizers. Over 6 weeks, patients treated with olanzapine added to mood stabilizers had significantly greater mean improvements from baseline on five of the nine subjective scales on the QLI, compared to patients treated with placebo added to mood stabilizers. Changes in scores on the subjective scales of the QLI were more strongly correlated to changes in depressive symptomatology measured by the HAM-D, than to changes in symptoms of mania measured by the Y-MRS. CONCLUSION: The results of this study demonstrate that patients receiving adjunctive treatment have significantly greater improvements in both clinical and quality of life outcomes compared to monotherapy with mood stabilizers.  相似文献   
25.
BACKGROUND: A substantial proportion of patients with bipolar disorder are characterized by a rapidly cycling course and are particularly resistant to conventional treatment. METHODS: This secondary analysis, defined a priori, was conducted on a larger data set from patients with bipolar I disorder to determine the efficacy of a 3-week treatment with the atypical antipsychotic olanzapine (5-20 mg/day, n=19) versus placebo (n=26) in patients with >or=4 episodes in the preceding year. RESULTS: Significantly fewer placebo patients completed treatment (34.6 vs. 73.7%, P=0.016), and more than half discontinued due to lack of efficacy (53.8 vs. 21.1%, P=0.035). Olanzapine reduced Young Mania Rating Scale (YMRS) total scores significantly more than placebo (-13.9 vs. -4.1, P=0.011). Clinical responses, defined as >or=50% improvement in YMRS, were achieved in 58% of olanzapine patients, compared with 28% of placebo patients (P=0.066). Extrapyramidal symptoms were not significantly changed in either group. Somnolence was the most common adverse event in both groups (olanzapine: 52.6%, placebo: 23.1%; P=0.060). No event occurred significantly more frequently with olanzapine than with placebo. No patients discontinued due to an adverse event. LIMITATIONS: The duration of this study was limited to 3 weeks, precluding conclusions about long-term efficacy of olanzapine. Moreover, a sizeable placebo effect was obtained, possibly masking optimal therapeutic effect. Despite these limitations, treatment differences in efficacy were highly significant. CONCLUSIONS: These results indicate that olanzapine was effective in reducing symptoms of mania and well tolerated in patients with bipolar I disorder with a rapid-cycling course.  相似文献   
26.
27.
We have previously suggested that tumor angiogenesis in human gliomas is regulated by a paracrine mechanism involving vascular endothelial growth factor (VEGF) and flt-I (VEGF-receptor I). VEGF, an endothelial-cell-specific mitogen, is abundantly expressed in glioma cells which reside along necrotic areas, whereas fit-I, a tyrosine-kinase receptor for VEGF, is expressed in tumor endothelial cells, but not in endothelial cells in normal adult brain. Recently, a second tyrosine-kinase receptor which binds VEGF with high affinity, designated KDR or flk-I, has been described. We performed in situ hybridization for VEGF mRNA, flt-I mRNA and KDR mRNA on serial sections of normal brain, low-grade and high-grade glioma specimens. We show that KDR mRNA is co-expressed with flt-I in vascular cells in glioblastoma but not in low-grade glioma. Since flt-I and KDR are not expressed in endothelial cells in the normal adult brain, the coordinate up-regulation of 2 receptors for VEGF appears to be a critical event which controls tumor angiogenesis. Immunocytochemistry with a monoclonal anti-VEGF antibody revealed significant amounts of VEGF protein in the same glioma cells that expressed VEGF mRNA. The largest amount of VEGF immunoreactivity, however, was detected on the vasculature of glioblastomas, the site where VEGF exerts its biological functions. These findings suggest that VEGF is produced and secreted by glioma cells and acts on tumor endothelial cells which express VEGF receptors. To further characterize VEGF-producer cells in vivo, we investigated cellular proliferation, immunoreactivity to the p53 tumor-suppressor gene product and epidermal-growth-factor-receptor(EGFR) expression on serial sections by immunocytochemistry. VEGF-producer cells did not show increased cellular proliferation, p53 immunoreactivity or EGFR immunoreactivity as compared with glioma cells which did not express VEGF. Our studies therefore do not demonstrate evidence for a growth advantage of VEGF-producer cells in vivo or VEGF induction by p53 mutation or EGFR over-expression. © 1994 Wiley-Liss, Inc.  相似文献   
28.
There is a consensus among researchers about the critical elements for effective reading instruction. These elements are the integration of explicit instruction in the alphabetic principle, reading for meaning, and opportunity to learn. These critical elements are present in classroom instruction that prevents reading difficulties as well as effective small-group and one-on-one interventions. Research on effective classroom instruction and reading interventions is described, and the case is argued that the most effective intervention is provided early--in kindergarten through 2nd grade--rather than after 3rd grade, and allows for sufficient intensity, duration, and supportiveness that no child is left behind. Policy implications for changes in (a) the way learning disabilities are identified and (b) the content of professional development of teachers are discussed.  相似文献   
29.
Brain mechanisms for reading words and pseudowords: an integrated approach   总被引:5,自引:1,他引:4  
The present study tested two predictions of dual-process models of reading: (i) that the brain structures involved in sublexical phonological analysis and those involved in whole-word phonological access during reading are different; and (ii) that reading of meaningful items, by means of the addressed phonology process, is mediated by different brain structures than reading of meaningless letter strings. We obtained brain activation profiles using Magnetic Source Imaging and, in addition, pronunciation latencies during reading of: (i) exception words (primarily involving addressed phonology and having meaning), (ii) pseudohomophones (requiring assembled phonology and having meaning), and (iii) pseudowords (requiring assembled phonology but having no meaning). Reading of meaningful items entailed a high degree of activation of the left posterior middle temporal gyrus (MTGp) and mesial temporal lobe areas, whereas reading the meaningless pseudowords was associated with much reduced activation of these two regions. Reading of all three types of print resulted in activation of the posterior superior temporal gyrus (STGp), inferior parietal and basal temporal areas. In addition, pronunciation speed of exception words correlated significantly with the onset of activity in MTGp but not STGp, whereas the opposite was true for pseudohomophones and pseudowords. These findings are consistent with the existence of two different brain mechanisms that support phonological processing in word reading: one mechanism that subserves assembled phonology and depends on the posterior part of STGp, and a second mechanism that is responsible for pronouncing words with rare print-to-sound correspondences and does not necessarily involve this region but instead appears to depend on MTGp.  相似文献   
30.
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