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排序方式: 共有397条查询结果,搜索用时 15 毫秒
131.
Acute pulmonary embolism: ancillary findings at spiral CT 总被引:28,自引:1,他引:27
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133.
A dynamic probabilistic model based on hazard rate analysis, Monte Carlo modeling, and lead-time estimation techniques was developed to determine the optimal timing and frequency of chest radiography in the monitoring for relapse of children with treated Hodgkin disease. The analysis incorporates the performance characteristics of chest radiography, the natural history of the disease process, and therapeutic efficacy as a function of earliness of detection in the determination of optimal strategy. Examples of the model applied to the experiences of Stanford Medical Center and St. Jude Children's Research Hospital illustrate the utility of such a model in customizing an optimal monitoring strategy for a specific institution and clinical experience. The results suggest that monitoring protocols significantly overutilize chest radiography in the evaluation for recurrent Hodgkin disease in children. 相似文献
134.
A modified, sensitive, solid-phase assay for platelet-associated IgG is reported. Direct comparisons were made between a 125I monoclonal radioimmunoassay (RIA) and the polyclonal antibody latex particle assay. In 209 simultaneous comparisons with the RIA, the sensitivity of the latex test was 91 percent, specificity was 100 percent, and overall efficiency was 97 percent. Commencing with platelet-rich plasma, the direct latex particle test for platelet-bound IgG requires 45 minutes; 90 minutes are required to crossmatch one patient with 12 donors. The advantages of the latex assay are absence of radioactivity, stability of reagents, economy, speed, specificity, and sensitivity. 相似文献
135.
Cardiophrenic varices in portal hypertension: evaluation with CT 总被引:6,自引:0,他引:6
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137.
Misinterpretation of the diaphragmatic crura on axial computed tomography images is a recognized pitfall in diagnosis. The right diaphragmatic crus is generally longer and thicker than the left. The authors observed a case in which the left crus was thicker than the right, causing diagnostic difficulty. Obtaining scans at full expiration and full inspiration clarified the situation. Confirmation of respiratory variation in crural thickness was obtained in ten patients. The crura increased in thickness on inspiration, compared with the size on expiration. 相似文献
138.
Russell KJ; Boileau MA; Ireton RC; Higano CS; Collins C; Koh WJ; Griffin BR; Chapman WH; Griffin TW 《Radiology》1988,167(3):845-848
Fourteen patients with transitional cell carcinoma of the urinary bladder were treated with 4,000 cGy of pelvic irradiation concurrent with two 96-hour infusions of 5-fluorouracil (5-FU). Three weeks after completion of this regimen, patients underwent repeat cystoscopy and deep-muscle biopsy at the site of their original neoplasms. Eight of 14 (57%) had no tumor left in the biopsy specimen, and they received an additional course of chemotherapy and radiation therapy to a total dose of 4,400 cGy to the pelvis and 6,000 cGy to the bladder. Five of the 14 had residual tumor in the biopsy specimen (one did not undergo biopsy) and went on to planned cystectomy. Two of the five had no tumor in the cystectomy specimen. Overall, ten of the 14 patients (71%) have been downstaged to a condition of P0 (no tumor) following 4,000 cGy and two courses of 5-FU. Of eight patients with retained bladders, seven remain well at a median follow-up of 7 months. At a range of follow-up of 3-21 months and a median of 7 months, 13 of 14 patients remain tumor-free. This regimen results in a greater percentage of downstaging than conventional irradiation alone, and may allow bladder preservation for those with radiation therapy- and chemotherapy-responsive tumors. 相似文献
139.
Plasma vitronectin polymorphism in normal subjects and patients with disseminated intravascular coagulation 总被引:4,自引:0,他引:4
Vitronectin, also known as serum-spreading factor or S-protein, mediates cell adhesion and inhibits formation of the membrane-lytic complex of complement and the rapid inactivation of thrombin by antithrombin III in the presence of heparin. Vitronectin is normally present in plasma at a concentration of approximately 300 micrograms/mL. The investigators quantified plasma vitronectin with an enzyme-linked immunosorbent assay and visualized reduced and nonreduced vitronectin by immunoblotting after separation of plasma or serum by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The concentration of plasma vitronectin was markedly reduced in some patients with disseminated intravascular coagulation, especially in those with liver failure; it was near normal in patients with metastatic cancer and acute leukemia. Patients with vitronectin levels less than 40% normal invariably had low fibrinogen and antithrombin III and a prolonged prothrombin time. In both normal and patient plasmas there was heterogeneity in the ratio of the 75,000- and 65,000-mol wt polypeptides of reduced vitronectin: 18% had mostly the 75,000-mol wt polypeptide, 59% had roughly equal amounts of the two polypeptides, and 22% had mostly the 65,000-mol wt polypeptide. This polymorphism is inherited and appears to be due to two alleles that are present with approximately equal frequency. The blotting patterns of vitronectin in reduced and nonreduced plasmas were largely unaltered in plasma of patients with defibrination syndrome, fibrinolysis, liver failure, sepsis, metastatic cancer, and acute leukemia. There was no evidence of fragmentation of vitronectin or formation of the disulfide-bonded complex of vitronectin and thrombin-antithrombin III that is found when blood is clotted. Thus these results corroborate in vitro observations that the liver is the major source of plasma vitronectin, suggest that vitronectin may become depleted during disseminated intravascular coagulation, and define a genetic polymorphism of vitronectin. 相似文献
140.
Human hepatoma cells secrete single chain factor X, prothrombin, and antithrombin III 总被引:10,自引:1,他引:9
The human hepatoma cell line, Hep G2, was analyzed for the ability to synthesize and secrete several coagulation proteins. Using specific radioimmunoassays, factor X, prothrombin, and antithrombin III were present in 8-day culture supernatants at 62, 405, and 1,220 ng/mL, respectively. Factor IX was not detected, either in supernatants or in cell extracts. Intrinsically labeled factor X was secreted as a single- chain polypeptide of 66,000 daltons, as measured by sodium dodecylsulfate-polyacrylamide gels under nonreduced and reduced conditions. Immunoblots of Hep G2 supernatants and normal human plasma also indicate the presence of single-chain factor X. These findings support the hypothesis of a postsecretion proteolytic cleavage of factor X into the two-chain form. Prothrombin and antithrombin represented their plasma protein counterparts structurally, with molecular weights of 73,000 and 61,000, respectively. Secreted factor X, prothrombin, and antithrombin III were biologically active, as determined in coagulation or chromogenic assays, and all three activities were neutralized by monospecific antibodies. Vitamin K increased the quantity of prothrombin secreted by twofold, without affecting the rate of secretion over a five-day culture period, and had an apparent transient inhibitory effect on secretion of antithrombin III. Warfarin caused a three to fourfold decrease in the rate and quantity of secreted prothrombin, but did not affect intracellular concentrations. The intracellular and extracellular concentrations and rate of secretion of antithrombin III were not modulated by warfarin. These data suggest that the Hep G2 cell line may provide a useful model for assessing the regulation of biosynthesis and secretion of human coagulation proteins. 相似文献