全文获取类型
收费全文 | 19364篇 |
免费 | 1224篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 183篇 |
儿科学 | 430篇 |
妇产科学 | 447篇 |
基础医学 | 2848篇 |
口腔科学 | 721篇 |
临床医学 | 2229篇 |
内科学 | 4125篇 |
皮肤病学 | 366篇 |
神经病学 | 1790篇 |
特种医学 | 555篇 |
外科学 | 2094篇 |
综合类 | 108篇 |
一般理论 | 9篇 |
预防医学 | 1795篇 |
眼科学 | 275篇 |
药学 | 1465篇 |
中国医学 | 108篇 |
肿瘤学 | 1108篇 |
出版年
2023年 | 190篇 |
2022年 | 258篇 |
2021年 | 501篇 |
2020年 | 308篇 |
2019年 | 531篇 |
2018年 | 702篇 |
2017年 | 507篇 |
2016年 | 555篇 |
2015年 | 702篇 |
2014年 | 769篇 |
2013年 | 1091篇 |
2012年 | 1636篇 |
2011年 | 1678篇 |
2010年 | 793篇 |
2009年 | 655篇 |
2008年 | 1243篇 |
2007年 | 1244篇 |
2006年 | 1164篇 |
2005年 | 1110篇 |
2004年 | 1061篇 |
2003年 | 953篇 |
2002年 | 875篇 |
2001年 | 172篇 |
2000年 | 163篇 |
1999年 | 141篇 |
1998年 | 110篇 |
1997年 | 87篇 |
1996年 | 109篇 |
1995年 | 64篇 |
1994年 | 47篇 |
1993年 | 51篇 |
1992年 | 86篇 |
1991年 | 86篇 |
1990年 | 74篇 |
1989年 | 85篇 |
1988年 | 66篇 |
1987年 | 72篇 |
1986年 | 72篇 |
1985年 | 76篇 |
1984年 | 68篇 |
1983年 | 43篇 |
1982年 | 39篇 |
1981年 | 50篇 |
1980年 | 32篇 |
1979年 | 41篇 |
1978年 | 19篇 |
1977年 | 22篇 |
1975年 | 19篇 |
1970年 | 21篇 |
1967年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
T Nagatake V T Hoang T Tegoshi J Rabbege T K Ann M Aikawa 《The American journal of tropical medicine and hygiene》1992,47(2):259-264
Autopsy samples from the brains of 20 patients who died of falciparum malaria were examined by light microscopy and by an immunohistologic method. Particular attention was paid to a comparison of the pathologic features of the white matter and the cortex. In the high-sequestration (greater than 50%) group (n = 8), the mean +/- SD percentage of cerebral microvessels that showed parasitized red blood cell (PRBC) sequestration was 71.2 +/- 8.1% in the cortex and 84.0 +/- 6.7% in the white matter. The difference in the PRBC sequestration rate between cortex and white matter was statistically significant (P less than 0.01). Perivascular and ring hemorrhages were seen more frequently in the white matter than in the cortex. Deposition of IgG and Plasmodium falciparum antigen in the cerebral microvessels was more highly significant in the white matter than in the cortex (P less than 0.01). Our study demonstrated that the localized concentration of PRBC sequestration in the brain correlated with the marked immunohistologic differences in the microvessels of cortex and white matter. 相似文献
22.
23.
Gliomatosis peritonei, the miliary implants of mature glial tissues on the peritoneum or omentum, is a rare complication of solid ovarian teratoma. Our case is reported and 38 previously reported cases are reviewed. The grade of the primary tumors varied from grade 0 to grade 3. Only five cases were composed entirely of mature tissues. Five of the 39 patients died. Despite of varied therapy, the rest of the patients were alive from 3 months to 38 years later. Inspite of intraperitoneal implants, the prognosis in patients with these tumors is good, irrespective of the mode of therapy. On the basis of this study, we recommended a conservative therapy for the primary tumor and therapy for the implants is not required. 相似文献
24.
25.
Scott A. Rodeo Jo A. Hannafin James Tom Russell F. Warren Thomas L. Wickiewicz 《Journal of orthopaedic research》1997,15(3):427-436
The purpose of this study was to test the hypothesis that specific cytokines are involved in the initiation and evolution of the fibrotic process in adhesive capsulitis of the shoulder. After approval from the Institutional Review Board, biopsies of shoulder capsule and synovium were collected during shoulder arthroscopy from 19 patients with adhesive capsulitis, 14 patients with nonspecific synovitis and no fibrosis or clinical evidence of adhesive capsulitis, and seven patients undergoing surgery for another pathology who had a normal capsule and synovium. Immunohistochemical localization with monoclonal antibodies to transforming growth factor-β and its receptor, platelet-derived growth factor and its receptor, basic fibroblast growth factor, interleukin-1β, tumor necrosis factor-α, and hepatocyte growth factor was performed using standard immunoperoxidase techniques. The frequency of cytokine staining was correlated with the clinical diagnosis Synovial cells, fibroblasts, T-cells, and B-cells were identified with specific antibodies, and newly synthesized matrix was examined for type-I and type-III collagen by immunohistochemical staining. The predominant cell types present were synovial cells and fibroblasts. Staining for type-III collagen in adhesive capsulitis tissues indicated new deposition of collagen in the capsule. There was staining for transforming growth factor-β and its receptor, platelet-derived growth factor and its receptor, interleukin-1β, and tumor necrosis factor-α in adhesive capsulitis and nonspecific synovitis tissues, compared with minimal staining in normal capsule. Staining was more frequent in snovial cells than in capsular cells. The frequency of cell and matrix staining for transforming growth factor-β, platelet-derived growth factor, and hepatocyte growth factor was greater in adhesive capsulitis tissues than in those from patients with nonspecific synovitis. No difference in the frequency of staining between primary (idiopathic) and secondary adhesive capsulitis was found. The results of this study indicate that adhesive/capsulitis involves both synovial hyperplasia and capsular fibrosis. Cytokines such as transforming growth factor-β and platelet-derived growth factor may be involved in the inflammatory and fibrotic processes in adhesive capsulitis. Matrix-bound transforming growth factor-β may act as a persistent stimulus, resulting in capsular fibrosis. Understanding the basic pathophysiology of adhesive capsulitis is an important step in the development of clinically useful antifibrotic agents that may serve as novel treatments for patients with this condition. 相似文献
26.
27.
28.
Sara Jo Nixon Austin L. Errico Oscar A. Parsons William R. Leber Cynthia J. Kelley 《Alcoholism, clinical and experimental research》1992,16(5):949-954
This study was conducted to determine whether alcoholic and control subjects respond differently to manipulations that either enhance personal involvement (PI) or reduce negative affect (R, relaxation) on tests of neuropsychological function. In Phase 1, 48 male alcoholics and 36 male control subjects completed neuropsychological tasks under standard instructional sets. In Phase 2, subjects completed equivalent forms of these tests under one of three randomly assigned conditions; the PI condition in which subjects were encouraged to identify specific ways of improving their performance, the R condition in which subjects participated in a short relaxation exercise designed to reduce anxiety, or a No Treatment (NT) condition in which no attempt to manipulate the subjects' involvement or affect was made. Alcoholics were inferior to controls in both Phase 1 and Phase 2 [Fs (1,82) > 5.03, ps < 0.03]. The experimental manipulation differentially affected measures of negative affect and effort in the predicted direction. There were no group x condition interactions. Alcoholic and control subjects responded comparably to the experimental manipulations. This investigation, in combination with others using related manipulations, reinforces the hypothesis that alcohol-related cognitives dysfunction reflects an underlying deficit in brain states. 相似文献
29.
The in vitro and in vivo effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0), a new antiinflammatory agent, on arachidonic acid metabolism were investigated in comparison with those of reference drugs. Although the inhibitory effect of T-614 on the synthesis of prostaglandins by rabbit renal microsomes was very weak (IC50 of 58 micrograms/ml), T-614 effectively inhibited the prostaglandin E2 (PGE2) generation by mouse fibroblasts stimulated with bradykinin with an IC50 value of 0.47 micrograms/ml. The suppressive effect of T-614 on the PGE2 generation in fibroblasts was also found when cells were stimulated with Ca ionophore A23187, but not when induced with arachidonic acid. T-614 suppressed the A23187-induced PGE2 generation by rat macrophages, but not the leukotriene B4 production. In addition, 5-lipoxygenase activities in guinea-pig peritoneal exudated cells were not inhibited. In in vivo experiments, at doses of more than 1 mg/kg, T-614 reduced the PGE2 contents in inflammatory exudate of rat carrageenin-sponge type inflammation, but it was almost inactive in inhibiting gastric prostaglandins production up to 100 mg/kg. T-614 also did not affect the urinary PGE2 excretion in rats, and slightly inhibited the thromboxane synthesis in rat blood. Furthermore, the convulsion-induced increase of PGE2 in mouse brain was inhibited by T-614. These data suggest that T-614 inhibits the production of cyclooxgenase-mediated products with apparently different mode from classical non-steroidal antiinflammatory drugs, and may partly explain the discrepancy in pharmacological properties between this compound and other drugs. 相似文献
30.
Abdulbaqi Al-Toma Marije S Goerres Jos W R Meijer B Mary E von Blomberg Peter J Wahab Jo A M Kerckhaert Chris J J Mulder 《Clinical gastroenterology and hepatology》2006,4(11):1322-7; quiz 1300
BACKGROUND & AIMS: Refractory celiac disease (RCD) may be subdivided into RCD types I and II with phenotypically normal and aberrant intraepithelial T-cell populations, respectively. In RCD II, transition into enteropathy-associated T-cell lymphoma (EATL) is seen frequently. We have evaluated the effect of cladribine (2-CDA), a purine analogue inducing T-cell depletion, on clinical, histopathologic, and immunologic parameters, as well as the toxicity and side effects in a group of RCD II patients. METHODS: Between 2000 and 2005, 17 patients were included (8 men, 9 women). All patients had a clonal rearrangement of the T-cell receptor gamma gene and immunophenotyping showed an aberrant T-cell population lacking surface expression of CD3, CD8, and T-cell receptor alphabeta, in the presence of expression of surface CD103 and intracytoplasmic CD3. Treatment consisted of 2-CDA (0.1 mg/kg/day) intravenously for 5 days, given in 1-3 courses every 6 months depending on the response. RESULTS: All patients tolerated 2-CDA without serious side effects. Six patients (35.8%) showed a clinical improvement (weight gain, improvement of diarrhea, and hypoalbuminemia). In 10 patients (58.8%) a significant histologic improvement and in 6 patients (35.2%) a significant decrease in aberrant T cells was seen. Seven patients (41.1%) developed EATL and died subsequently. One patient died of progressive refractory state with emaciation. CONCLUSIONS: Treatment with 2-CDA in RCD II is feasible, well tolerated, and can induce clinical and histologic improvement as well as a significant decrease of aberrant T cells in a subgroup of patients, albeit it does not prevent EATL development. However, the earlier reported potential risk of precipitating an overt lymphoma should be taken into consideration. 相似文献