全文获取类型
收费全文 | 11257篇 |
免费 | 850篇 |
国内免费 | 181篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 488篇 |
妇产科学 | 323篇 |
基础医学 | 1518篇 |
口腔科学 | 238篇 |
临床医学 | 1139篇 |
内科学 | 2665篇 |
皮肤病学 | 172篇 |
神经病学 | 730篇 |
特种医学 | 592篇 |
外科学 | 1430篇 |
综合类 | 213篇 |
一般理论 | 10篇 |
预防医学 | 705篇 |
眼科学 | 287篇 |
药学 | 710篇 |
中国医学 | 100篇 |
肿瘤学 | 898篇 |
出版年
2023年 | 62篇 |
2022年 | 110篇 |
2021年 | 231篇 |
2020年 | 131篇 |
2019年 | 239篇 |
2018年 | 259篇 |
2017年 | 193篇 |
2016年 | 203篇 |
2015年 | 256篇 |
2014年 | 323篇 |
2013年 | 418篇 |
2012年 | 670篇 |
2011年 | 679篇 |
2010年 | 399篇 |
2009年 | 395篇 |
2008年 | 636篇 |
2007年 | 652篇 |
2006年 | 638篇 |
2005年 | 599篇 |
2004年 | 536篇 |
2003年 | 467篇 |
2002年 | 439篇 |
2001年 | 429篇 |
2000年 | 412篇 |
1999年 | 325篇 |
1998年 | 200篇 |
1997年 | 154篇 |
1996年 | 146篇 |
1995年 | 125篇 |
1994年 | 98篇 |
1993年 | 109篇 |
1992年 | 200篇 |
1991年 | 164篇 |
1990年 | 160篇 |
1989年 | 181篇 |
1988年 | 162篇 |
1987年 | 146篇 |
1986年 | 137篇 |
1985年 | 115篇 |
1984年 | 82篇 |
1983年 | 56篇 |
1982年 | 54篇 |
1981年 | 39篇 |
1980年 | 39篇 |
1979年 | 38篇 |
1978年 | 23篇 |
1977年 | 35篇 |
1976年 | 27篇 |
1975年 | 24篇 |
1974年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
JJ Piccininni 《The Journal of the Canadian Chiropractic Association》1994,38(4):223-226
This paper examines various devices used in strength building exercise programs. These include free weights, pulley machines, variable resistance weight machines, isokinetic units and elastic tubing and banding. Advantages and disadvantages of each are discussed and examined from the view point of the health care provider and the suitability of each type of device for prescribed progressive resistance exercise programs for patients. In addition to such practical aspects such as cost and maintenance, biomechanical factors, types of contraction elicited, ease of patient instruction and proprioception benefits are also compared in order to assist the clinician in selecting the most appropriate equipment for each individual patient. 相似文献
52.
53.
54.
Interleukin-5 has a specific role in various eosinophilic activities. It is the predominant cytokine produces by activated T-lymphocytes isolated from patients with idiopathic hypereosinophilic syndrome. We studied a young patient suffering from idiopathic hypereosinophilic syndrome who presented with Horner's syndrome, peripheral neuropathy and skin ulcers. The IL-5 gene expression by CD4+ T-lymphocytes and the peripheral eosinophil count were raised. The skin ulcers continued to deteriorate despite a swift reduction of the IL-5 gene expression and peripheral eosinophil count following systemic corticosteroid treatment. We suggest that peripheral eosinophilia may not be responsible for the damage in skin lesions and more aggressive treatment may be required. 相似文献
55.
Liver transplantation for chronic hepatitis B with lamivudine-resistant YMDD mutant using add-on adefovir dipivoxil plus lamivudine. 总被引:5,自引:0,他引:5
Chung Mau Lo Chi Leung Liu George K Lau See Ching Chan Irene O Ng Sheung Tat Fan 《Liver transplantation》2005,11(7):807-813
Lamivudine treatment in patients with chronic hepatitis B virus (HBV) infection may improve clinical state and suppress viral replication before liver transplantation. Emergence of lamivudine-resistant YMDD mutant is common. We report the results of liver transplantation in 16 patients with pretransplantation YMDD mutants after receiving lamivudine treatment for a median of 738 days (range, 400-1799 days). Adefovir dipivoxil (10 mg daily) was added on to lamivudine for a median of 20 days (range, 8-271 days) before (n = 11) or at (n = 5) liver transplantation, and the combination was continued indefinitely thereafter. Eight patients received additional intravenous hepatitis B immune globulin (HBIG) for a median of 24 months. Fifteen patients with known pre-adefovir HBV DNA levels had a median titer of 14,200 x 10(3) copies/mL (2 x 10(3) to 4,690,000 x 10(3) copies/mL), and 14 had HBV DNA >10(5) copies/mL. All but 1 patient remained positive for HBV DNA (by quantitative polymerase chain reaction [qPCR]) at the time of liver transplantation, and the titer was greater than10(5) copies/mL in 8 patients. The median follow-up after liver transplantation was 21.1 (range, 4.4-68.9) months. One patient (6%) died of an unrelated cause 12.2 months after transplantation, and 15 patients (94%) were alive with the original graft. All patients cleared HBV DNA and had no detectable HBV DNA by qPCR at the latest follow-up. Fourteen patients had cleared hepatitis B surface antigen (HBsAg), but 2 patients who received only adefovir dipivoxil and lamivudine without HBIG remained HBsAg positive after 7.7 and 9.5 months. Serum HBV DNA, however, was negative, and there was no biochemical or histological evidence of recurrence. Adefovir dipivoxil was well tolerated with no significant renal toxicity. In conclusion, a combination of add-on adefovir dipivoxil plus lamivudine therapy provides effective prophylaxis in patients with pretransplantation YMDD mutant that may be actively replicating. The cost effectiveness of additional passive immunoprophylaxis remains to be defined. 相似文献
56.
Pramod K Pal Joanne Leung Katya Hedrich Ali Samii Abraham Lieberman Paul A Nausieda Donald B Calne Xandra O Breakefield Christine Klein A Jon Stoessl 《Movement disorders》2002,17(4):789-794
There are few reports of positron emission tomography (PET) in juvenile parkinsonism (JP). We report on the results of (18)F-6-fluoro-L-dopa (FD) PET in a 14-year-old patient with JP of 5 years duration associated with atypical features. This is the youngest subject to be investigated to date. There was a severe asymmetric reduction in striatal FD uptake, with a rostrocaudal gradient in the putamen similar to that seen in adult-onset idiopathic parkinsonism. Extensive DNA analysis in this patient did not show mutations in the parkin gene. 相似文献
57.
Retroperitoneal soft-tissue sarcoma: analysis of 500 patients treated and followed at a single institution. 总被引:29,自引:1,他引:28
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE: To analyze treatment and survival of a large cohort of patients with retroperitoneal soft-tissue sarcomas (STS) treated and prospectively followed at a single institution. SUMMARY BACKGROUND DATA: Retroperitoneal STS are relatively uncommon and constitute a difficult management problem. Although surgical resection is often difficult or impossible, current chemotherapy is not effective and radiation is limited by toxicity to adjacent structures. Thus, complete surgical resection remains the most effective modality for selected primary and recurrent disease. METHODS: Five hundred patients with retroperitoneal STS were admitted and treated between July 1, 1982, and September 30, 1997, and prospectively followed. Patient, tumor, and treatment variables were analyzed for disease-specific and disease-free survival. Survival was determined with the Kaplan-Meier method. Statistical significance was evaluated using the logrank test for univariate influence and Cox model stepwise regression for multivariate influence. RESULTS: Two hundred seventy-eight patients (56%) had primary disease and 222 (44%) recurrent disease. Median follow-up was 28 months (range 1 to 172 months), 40 months for survivors. Median survival was 72 months for patients with primary disease, 28 months for those with local recurrence, and 10 months for those with metastasis. For patients with primary or locally recurrent tumors, unresectable disease, incomplete resection, and high-grade tumors significantly reduced survival time. CONCLUSIONS: In this study of patients with retroperitoneal STS, stage at presentation, high histologic grade, unresectable primary tumor, and positive gross margin are strongly associated with the tumor mortality rate. Patients approached with curative intent should undergo aggressive attempts at complete surgical resection. Incomplete resection should be undertaken only for symptom relief. 相似文献
58.
We describe a radial partition enzyme immunoassay in which fully automated quantification of human thyrotropin (hTSH) takes less than 11 min. This "sandwich"-type assay involves two monoclonal antibodies, both specific for the intact hTSH molecule. The solid phase consists of tabs of glass-fiber filter paper containing a pre-immobilized monoclonal anti-hTSH antibody complexed with a goat antibody specific for the Fc region of mouse IgG. The patient's sample is first applied to the central "reaction zone" of the tab, wherein hTSH binds to the immobilized antibody. Application of a buffered solution containing enzyme-labeled Fab' fragments of the second monoclonal anti-hTSH antibody initiates "sandwich" formation. A wash buffer containing a fluorogenic substrate elutes unbound conjugate to the tab periphery. The bound enzyme conjugate is quantified by measuring the rate of increase in fluorescence in the reaction zone of the tab, then converting the rate to clinical units by comparison with a stored calibration curve. The clinical utility and performance of the present assay compare favorably with those of other sensitive assays for hTSH. 相似文献
59.
Superior mesenteric artery is more important than inferior mesenteric artery in maintaining colonic mucosal perfusion and integrity in rats 总被引:1,自引:0,他引:1
Dr. Felix W. Leung MD Kenny C. Su MD Jose M. Pique MD Gerard Thiefin MD Edward Passaro Jr MD Paul H. Guth MD 《Digestive diseases and sciences》1992,37(9):1329-1335
Mucosal hemodynamics (by reflectance spectrophotometry) and mucosal damage (by histologic examination) following acute colonic ischemia were evaluated in different anatomic locations in the colon of anesthetized rats. The reflectance spectrophotometer provides an index of mucosal hemoglobin concentration (IHB) and an index of oxygen saturation of hemoglobin (ISO2). The patterns of ischemia without congestion (IHB, ISO2) during superior mesenteric artery occlusion, and ischemia with congestion (IHB, ISO2) during portal vein occlusion, previously demonstrated in the stomach and duodenum, are also applicable to the colon. The significant linear correlations between changes (as percent of baseline) in IHB, ISO2, and hydrogen gas clearance suggest that changes in these indices are adequate indicators of changes in colonic mucosal perfusion. Superior mesenteric artery ligation produced significant reductions in both indices, and an increase in damage in the mucosa of the cecum, transverse colon, splenic flexure, and left colon, but not the rectum. Inferior mesenteric artery ligation produced only slight reduction in these indices and minimal damage only in the mucosa of the splenic flexure. These results support the hypothesis that the superior mesenteric artery is more important than the inferior mesenteric artery in maintaining colonic perfusion and colonic mucosal integrity in the rat.Supported by the American Society for Gastrointestinal Endoscopy Career Development Award (H850208, H870212), Veterans Administration Medical Research Funds; and in part by research grants (0162-01, 0162-02; 0291-01) from the Smokeless Tobacco Research Council, Inc.; and by funds provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco Related Disease Research Program of the University of California. 相似文献
60.
P C Leung 《Microsurgery》1989,10(3):242-244
This study reports the results of 30 patients who entered a program of sensory reeducation following toe-to-thumb transfer. Results were analyzed after subdividing the patients into those whose injury had produced severe scarring (fibrotic group, N = 15) and those with clean, more distal amputations (non-fibrotic group, N = 15). Patients who were unable to complete sensory reeducation were considered as "drop-out" controls. Although the follow-up time was less than 1 year, the group receiving sensory reeducation did improve to a greater degree and more quickly than the controls, with the level of two-point discrimination recovered being better than that originally present in the toe. 相似文献