首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21345篇
  免费   1244篇
  国内免费   91篇
耳鼻咽喉   243篇
儿科学   341篇
妇产科学   222篇
基础医学   2775篇
口腔科学   746篇
临床医学   2000篇
内科学   4420篇
皮肤病学   541篇
神经病学   2367篇
特种医学   1326篇
外科学   3492篇
综合类   110篇
一般理论   7篇
预防医学   1080篇
眼科学   426篇
药学   1126篇
中国医学   53篇
肿瘤学   1405篇
  2023年   149篇
  2022年   300篇
  2021年   558篇
  2020年   386篇
  2019年   456篇
  2018年   576篇
  2017年   468篇
  2016年   625篇
  2015年   695篇
  2014年   860篇
  2013年   1071篇
  2012年   1687篇
  2011年   1589篇
  2010年   973篇
  2009年   887篇
  2008年   1416篇
  2007年   1523篇
  2006年   1404篇
  2005年   1321篇
  2004年   1187篇
  2003年   1088篇
  2002年   974篇
  2001年   249篇
  2000年   218篇
  1999年   253篇
  1998年   187篇
  1997年   166篇
  1996年   113篇
  1995年   68篇
  1994年   60篇
  1993年   64篇
  1992年   102篇
  1991年   101篇
  1990年   91篇
  1989年   72篇
  1988年   92篇
  1987年   70篇
  1986年   43篇
  1985年   52篇
  1984年   55篇
  1983年   26篇
  1982年   19篇
  1980年   23篇
  1979年   32篇
  1978年   19篇
  1977年   17篇
  1976年   22篇
  1975年   21篇
  1974年   30篇
  1973年   20篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild...  相似文献   
2.
3.
4.
The regrowth of amputated digit tips represents a unique regenerative healing in mammals with subcutaneous volume regrowth, restoration of dactylogram, and suppression of scar formation. Although factor analysis in amphibians and even in mice is easy to obtain, safety of harvesting biomaterial from human digit tip amputations for analysis has not yet been described.The aim of this study was to evaluate if recovering wound exudate does hamper clinical outcome or influence microbiologic or inflammation status.A predefined cohort of 18 patients with fresh digit tip amputations was randomly assigned to receive standard therapy (debridement, occlusive dressing) with (n = 9) or without (n = 9) collection of the whole wound exudate in every dressing change. Primary endpoint (lengthening) and secondary endpoints (regeneration of dactylogram, nail bed and bone healing, time to complete wound closure, scar formation, 2-point discrimination, microbiologic analysis, inflammatory factors interleukin (IL)-1α, tumor necrosis factor-α, IL-4, and IL-6) were determined by an independent, blinded observer.Patients’ characteristics showed no significant differences between the groups. All patients completed the study to the end of 3 months follow-up. Exudate collection did not influence primary and secondary endpoints. Furthermore, positive microbiologic findings as well as pus- and necrosis-like appearance neither impaired tissue restoration nor influenced inflammatory factor release.Here, the authors developed an easy and safe protocol for harvesting wound exudate from human digit tip amputations. For the first time, it was shown that harvesting does not impair regenerative healing. Using this method, further studies can be conducted to analyze regeneration associated factors in the human digit tip.DRKS.de Identifier: DRKS00006882 (UTN: U1111-1166-5723).  相似文献   
5.
INTRODUCTION H pylori infection is an established risk factor for development of gastric cancer[1,2]. According to the model of carcinogenesis of the intestinal type adenocarcinoma proposed by Correa, the multi-step development starts from the condition o…  相似文献   
6.
In the present experiments we have investigated the influence of wall shear rate and axial position on platelet and fibrin deposition which results when flowing human non-anticoagulated blood is exposed to either non-procoagulant fibrillar collagen (human type III) or procoagulant subendothelium (rabbit aorta). Platelet adhesion, thrombus volume and fibrin deposition were morphometrically evaluated at axial positions of 1 and 13 mm following perfusions for 5 min at shear rates of 100, 650 and 2,600 s-1. An axially-dependent decrease of platelet adhesion (34-57%, p less than 0.01-0.05) and thrombus volume (57-80%, p less than 0.05) was observed on collagen at all shear rates. On subendothelium, an axially-dependent decrease was observed for platelet adhesion only at 100 s-1 (29%; p less than 0.01) and for thrombus volume at shear rates of 650 s-1 and above (49-58%, p less than 0.01). Deposition of fibrin on subendothelium was axially decreased (16-42%, p less than 0.05) at all shear rates, while no significant axial differences were seen on collagen. However, substantially more fibrin was deposited on the subendothelium (p less than 0.05), and the upstream platelet adhesion and thrombus volume were lower than on collagen (p less than 0.05) at 100 s-1 and 650 s-1. The axially-dependent phenomena on the two surfaces are consistent with the concept of rapid-growing upstream thrombi which deplete the blood layer streaming adjacent ot the surface of platelets, leading to decreased platelet deposition further downstream.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.
OBJECTIVE: To assess the outcome of the surgical treatment of patients who had adrenalectomy for phaeochromocytoma. DESIGN: Retrospective clinical study. SETTINGS: University hospital, Germany. SUBJECTS: 87 consecutive patients with phaeochromocytoma who were operated on. INTERVENTIONS: 29 flank and 58 transabdominal adrenalectomies between 1974 and 2000. RESULTS: The mean tumour diameter was 5 cm (range 2-13), and the mean weight 91 g (range 7-550). The postoperative hospital stay was 11 days. The flank incision entailed the shortest operating time (95 minutes). Two of the phaeochromocytomas were malignant. There were two wound infections but no deaths. With a correct selection of patients, a flank incision is safe. Endoscopic retroperitoneal adrenalectomies should be preferred.  相似文献   
8.
OBJECTIVES: Aim of this study is to correlate distribution pattern of lower limb atherosclerosis with cardiovascular risk factor profile of patients with peripheral arterial occlusive disease (PAD). PATIENTS AND METHODS: Analysis is based on a consecutive series of 2659 patients (1583 men, 1076 women, 70+/-11 years) with chronic PAD of atherosclerotic origin undergoing primary endovascular treatment of lower extremity arteries. Pattern of atherosclerosis was grouped into iliac (n=1166), femoropopliteal (n=2151) and infrageniculate (n=888) disease defined according to target lesions treated. A multivariable multinomial logistic regression analysis was performed to assess relation with age, gender and classical cardiovascular risk factors (diabetes mellitus, arterial hypertension, hypercholesterolemia, cigarette smoking) using femoropopliteal disease as reference. RESULTS: Iliac disease was associated with younger age (RRR 0.95 per year of age, 95%-CI 0.94-0.96, p<0.001), male gender (RRR 1.32, 95%-CI 1.09-1.59, p=0.004) and cigarette smoking (RRR 2.02, 95%-CI 1.68-2.42, p<0.001). Infrageniculate disease was associated with higher age (RRR 1.02, 95%-CI 1.01-1.02, p<0.001), male gender (RRR 1.23, 95%-CI 1.06-1.41, p=0.005) and diabetes mellitus (RRR 1.68, 95%-CI 1.47-1.92, p<0.001). Hypercholesterolemia was less prevalent in patients with lesions below the knee (RRR 0.82, 95%-CI 0.71-0.94, p=0.006), whereas no distinct pattern was apparent related to arterial hypertension. CONCLUSION: Clinical phenotype of peripheral atherosclerosis varies with prevalence of cardiovascular risk factors suggesting differences in mechanisms involved in iliac as compared with infrageniculate lesions. Identification of molecular mechanism might have influence on future therapeutic strategies in PAD patients.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号