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51.
It has been hypothesized that normal pruning of exuberant branching of afferent neurons in the developing cochlea is caused by the arrival of the olivocochlear efferent neurons and the resulting competition for synaptic sites on hair cells. This hypothesis was supported by a report that afferent innervation density on mature outer hair cells (OHCs) is elevated in animals deefferented at birth, before the olivocochlear system reaches the outer hair cell area (Pujol and Carlier [1982] Dev. Brain Res. 3:151-154). In the current study, this claim was evaluated quantitatively at the electron microscopic level in four cats that were de-efferented at birth and allowed to survive for 6-11 months. A semiserial section analysis of 156 OHCs from de-efferented and normal ears showed that, although de-efferentation essentially was complete in all four cases, the number and distribution of afferent terminals on OHCs was indistinguishable from normal, and the morphology of afferent synapses was normal in both the inner hair cell area and the OHC area. Thus, the postnatal presence of an efferent system is not required for the normal development of cochlear afferent innervation, and the synaptic competition hypothesis is not supported.  相似文献   
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Phyllodes tumors of the breast: a review of 32 cases   总被引:2,自引:0,他引:2  
Most general surgeons involved in breast cancer care have limited experience with phyllodes tumors. We analyzed a comprehensive database incorporating 8567 breast cancer cases treated surgically in the Tulsa, Oklahoma, region between 1969 and 1993. This yielded 32 cases of phyllodes tumors (0.37%) in 31 patients. The median age was 57 years (range, 18-91). There were 9 low-grade (28%), 2 intermediate-grade (6%), and 21 high-grade (66%) lesions. Size distribution consisted of 23 (72%) lesions 5 cm or less and 9 (28%) greater than 5 cm (mean, 3; range, 1.2-17.5 cm). Of 137 resected nodes in 13 patients, none were positive for metastatic disease. Surgical management consisted of wide excision or mastectomy. No patients received adjuvant chemoradiation therapy. The disease-free, locoregional disease-free, and overall mean survival rates were 80, 81, and 97 months, respectively. Ten-year disease-free survival (DFS), locoregional disease-free survival (LRDFS), and overall survival (OS) rates were 66, 72, and 55 per cent, respectively. Although there was a tendency toward a higher rate of locoregional recurrences and metastases with high-grade lesions, this was not statistically significant and did not affect DFS, LRDFS, or OS rates. Similarly, size of lesion did not affect DFS, LRDFS, or OS rates. Three patients (9.6%) had metastatic disease at presentation, and a further two (6.4%) developed metastases during follow-up. Overall, nine (28.1%) recurrences developed in eight patients, seven locoregional and two distant. Four patients (12.9%) died with evidence of disease. These findings indicate prolonged survival in this patient population with cystosarcoma phyllodes. Wide local excision of primary and recurrent lesions remains the mainstay of therapy. Neither regional lymph node dissection nor adjuvant chemoradiation adds significant benefit.  相似文献   
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The Community‐Engaged Research Team Support (CERTS) program was developed and tested to build research and partnership capacity for community‐engaged research (CEnR) teams. Led by the Northwestern University Clinical and Translational Sciences Institute (NUCATS), the goals of CERTS were: (1) to help community‐academic teams build capacity for conducting rigorous CEnR and (2) to support teams as they prepare federal grant proposal drafts. The program was guided by an advisory committee of community and clinical partners, and representatives from Chicago''s Clinical and Translational Science Institutes. Monthly workshops guided teams to write elements of NIH‐style research proposals. Draft reviewing fostered a collaborative learning environment and helped teams develop equal partnerships. The program culminated in a mock‐proposal review. All teams clarified their research and acquired new knowledge about the preparation of NIH‐style proposals. Trust, partnership collaboration, and a structured writing strategy were assets of the CERTS approach. CERTS also uncovered gaps in resources and preparedness for teams to be competitive for federally funded grants. Areas of need include experience as principal investigators, publications on study results, mentoring, institutional infrastructure, and dedicated time for research.  相似文献   
56.
Abstract: We report the case of an adolescent boy with aquagenic urticaria unresponsive to oral antihistamine therapy. We successfully treated his condition by topical application of a petrolatum‐containing cream as a protective coating. To our knowledge, this is the first report showing the use of topical therapy alone to treat aquagenic urticaria in a child. Based on the effectiveness, safety profile, and ease of use, clinicians may wish to consider this regimen as a first‐line therapy.  相似文献   
57.
Three invasive Streptococcus pneumoniae strains nonsusceptible to linezolid were isolated in the United States between 2001 and 2012 from the CDC''s Active Bacterial Core surveillance. Linezolid binds ribosomal proteins where structural changes within its target site may confer resistance. Our study identified mutations and deletions near the linezolid binding pocket of two of these strains within the rplD gene, which encodes ribosomal protein L4. Mutations in the 23S rRNA alleles or the rplV gene were not detected.  相似文献   
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Objective. To assess the effectiveness of virtual patient cases to promote self-directed learning (SDL) in a required advanced therapeutics course.Design. Virtual patient software based on a branched-narrative decision-making model was used to create complex patient case simulations to replace lecture-based instruction. Within each simulation, students used SDL principles to learn course objectives, apply their knowledge through clinical recommendations, and assess their progress through patient outcomes and faculty feedback linked to their individual decisions. Group discussions followed each virtual patient case to provide further interpretation, clarification, and clinical perspective.Assessments. Students found the simulated patient cases to be organized (90%), enjoyable (82%), intellectually challenging (97%), and valuable to their understanding of course content (91%). Students further indicated that completion of the virtual patient cases prior to class permitted better use of class time (78%) and promoted SDL (84%). When assessment questions regarding material on postoperative nausea and vomiting were compared, no difference in scores were found between the students who attended the lecture on the material in 2011 (control group) and those who completed the virtual patient case on the material in 2012 (intervention group).Conclusion. Completion of virtual patient cases, designed to replace lectures and promote SDL, was overwhelmingly supported by students and proved to be as effective as traditional teaching methods.  相似文献   
59.
The Diabetes Control and Complications Trial established that a stimulated C-peptide concentration ≥0.2 nmol/L at study entry among subjects with up to a 5-year diabetes duration is associated with favorable metabolic and clinical outcomes over the subsequent 7 years of follow-up. Herein we further examine the association of both fasting and stimulated C-peptide numerical values with outcomes. In the intensive treatment group, for a 50% higher stimulated C-peptide on entry, such as from 0.10 to 0.15 nmol/L, HbA1c decreased by 0.07% (0.8 mmol/mol; P = 0.0003), insulin dose decreased by 0.0276 units/kg/day (P < 0.0001), hypoglycemia risk decreased by 8.2% (P < 0.0001), and the risk of sustained retinopathy was reduced by 25% (P = 0.0010), all in unadjusted analyses. Other than HbA1c, these effects remained significant after adjusting for the HbA1c on entry. While C-peptide was not significantly associated with the incidence of nephropathy, it was strongly associated with the albumin excretion rate. The fasting C-peptide had weaker associations with outcomes. As C-peptide decreased to nonmeasurable concentrations, the outcomes changed in a nearly linear manner, with no threshold or breakpoint. While preservation of stimulated C-peptide at ≥0.2 nmol/L has clinically beneficial outcomes, so also does an increase in the concentration of C-peptide across the range of values.  相似文献   
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