全文获取类型
收费全文 | 196124篇 |
免费 | 3378篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 1295篇 |
儿科学 | 7186篇 |
妇产科学 | 3369篇 |
基础医学 | 19299篇 |
口腔科学 | 2156篇 |
临床医学 | 14567篇 |
内科学 | 35093篇 |
皮肤病学 | 958篇 |
神经病学 | 18938篇 |
特种医学 | 9668篇 |
外科学 | 31703篇 |
综合类 | 2803篇 |
一般理论 | 34篇 |
预防医学 | 20133篇 |
眼科学 | 3212篇 |
药学 | 10889篇 |
1篇 | |
中国医学 | 663篇 |
肿瘤学 | 17630篇 |
出版年
2021年 | 271篇 |
2020年 | 189篇 |
2019年 | 350篇 |
2018年 | 22218篇 |
2017年 | 17617篇 |
2016年 | 19787篇 |
2015年 | 1228篇 |
2014年 | 1290篇 |
2013年 | 1455篇 |
2012年 | 7954篇 |
2011年 | 22118篇 |
2010年 | 19362篇 |
2009年 | 12029篇 |
2008年 | 20442篇 |
2007年 | 22687篇 |
2006年 | 1575篇 |
2005年 | 3197篇 |
2004年 | 4291篇 |
2003年 | 5287篇 |
2002年 | 3420篇 |
2001年 | 996篇 |
2000年 | 1189篇 |
1999年 | 787篇 |
1998年 | 480篇 |
1997年 | 478篇 |
1996年 | 366篇 |
1995年 | 300篇 |
1994年 | 305篇 |
1993年 | 258篇 |
1992年 | 492篇 |
1991年 | 514篇 |
1990年 | 582篇 |
1989年 | 432篇 |
1988年 | 448篇 |
1987年 | 404篇 |
1986年 | 337篇 |
1985年 | 351篇 |
1984年 | 272篇 |
1983年 | 242篇 |
1982年 | 219篇 |
1981年 | 175篇 |
1980年 | 208篇 |
1979年 | 232篇 |
1978年 | 174篇 |
1977年 | 158篇 |
1976年 | 146篇 |
1974年 | 184篇 |
1973年 | 148篇 |
1972年 | 136篇 |
1971年 | 132篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
41.
L R?stam R V Luepker M B Mittelmark D M Murray J S Slater H Blackburn 《American journal of preventive medicine》1988,4(5):249-254
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community. 相似文献
42.
Irwin L. Flink 《Brain structure & function》2002,205(3):235-244
43.
Peter E Murray Thomas W Smyth Imad About Remeille Remusat Jean-Claude Franquin Anthony J Smith 《Journal of dentistry》2002,30(1):29-36
OBJECTIVES: The incidence of bacterial microleakage, pulp inflammation and necrosis associated with dentine etching treatments prior to restoration are not known. Consequently, to resolve some of the controversy surrounding the effects and importance of vital dentine etching, the authors investigated these factors. METHODS: 110 standardised class V cavities were cut into buccal dentine, without exposing the pulp of teeth scheduled for extraction for orthodontic reasons. Cavities were either left unetched, or etched with the non-equivalent treatments of phosphoric acid gel for 60s or Ethylenediaminetetraacetic acid (EDTA) for 30s, prior to placement of composite resin. Teeth were collected and pulp responses were evaluated according to ISO guidelines, using pathohistomorphometric analysis and ANOVA statistics. RESULTS: Etching was found to be correlated to bacterial microleakage (p=0.0001) and tertiary dentine formation (p=0.0023). Bacterial microleakage was correlated to inflammatory activity (p=0.0001). The frequency of bacterial microleakage was: no etching (65%), EDTA (51%) and phosphoric acid (PA) (20%). SIGNIFICANCE: Vital dentine etching treatment is of extreme importance for the placement of RC to minimise bacterial microleakage. PA etching proved to be more effective at preventing bacterial microleakage than non-etching, and etching with EDTA. 相似文献
44.
Dorsal dislocation of the ulnar styloid and extensor carpi ulnaris tendon into the distal radioulnar joint: the empty sulcus sign 总被引:1,自引:0,他引:1
Two cases of distal radioulnar joint (DRUJ) disruption and diastasis secondary to distal radial fractures were associated with displacement of the ulnar styloid and extensor carpi ulnaris (ECU) into the DRUJ. Both cases had a palpable empty ECU tendon sulcus. In one case surgical exploration revealed that the ulnar styloid, triangular fibrocartilage, and extensor carpi ulnaris tendon had dislocated into the DRUJ as a unit. The end result was good. In the second case lack of recognition and reduction of the ECU tendon and ulnar styloid led to persistent subluxation and diastasis. The end result was poor. Early recognition of the dislocation of the ulnar and ECU into the DRUJ and their significance may avoid poor results. 相似文献
45.
46.
47.
48.
Paul Hochstein Ulrich Glatzel Thomas Schmickal Andreas Wentzensen 《Trauma und Berufskrankheit》2002,4(2):s110-s114
The treatment of deep cartilage defects in load-bearing joints is a problem that still has no satisfactory solution. Full-thickness defects of the articular cartilage rarely heal spontaneously, usually leaving damage that can lead to early arthrosis. Techniques currently available for the treatment of chondral defects include abrasion, drilling, micro-fracturing, transplantation of tissue autografts and allografts, and cell transplantation. Osteochondral autograft transplantation is currently the only surgical cartilage repair technique known to lead to the formation of genuine hyaline articular cartilage and its retention at least in the medium term. The Draenert method, in which a water-cooled diamond bone-cutting system is used, is an effective procedure for resurfacing the joints affected by localised cartilaginous defects, even when there is also severe bone loss. Donor-side morbidity can be kept to a minimum by filling the defect caused by harvesting with a press-fit cylinder of cancellous bone covered with periosteum for protection. 相似文献
49.
Annemieke Smit-van Oosten Winston W. Bakker Harry van Goor 《Transplant international》2002,15(12):602-609
Ischemic injury plays an important role in chronic renal transplant failure (CRTF). Down-regulation of ecto-adenosine triphosphatase (ATPase) in combination with up-regulation of ecto-5'-nucleotidase is a hallmark of ischemic injury. We studied the expression of renal ecto-5'-nucleotidase and ecto-ATPase in experimental renal transplantation. Fisher 344-to-Lewis allografted rats were either treated with an angiotensin-converting enzyme inhibitor (ACEi) or left untreated. Lewis-to-Lewis syngrafted rats served as controls. Untreated allografted rats developed proteinuria, glomerulosclerosis, and mild intimal hyperplasia. ACEi completely prevented focal and segmental glomerulosclerosis (FGS) and proteinuria, but significantly enhanced intimal hyperplasia. Untreated allografted rats revealed marked vascular ecto-5'-nucleotidase activity, which increased with ACEi. Vascular ecto-5'-nucleotidase activity was absent in syngrafted animals. Ecto-5'-nucleotidase activity correlated well with intimal hyperplasia. Glomerular ecto-ATPase expression was significantly reduced in untreated allografted rats compared to syngrafted rats and correlated well with the extent of FGS. ACEi prevented reduction in glomerular ecto-ATPase. We found de-novo expression of ecto-5'-nucleotidase at sites of renal intimal hyperplasia. Glomerular ecto-ATPase expression was markedly reduced in allografted rats and was prevented by ACEi. These enzyme expression patterns suggest local ischemic damage in experimental CRTF. 相似文献
50.
J. Bryan Page 《Journal of urban health》2005,82(3):iii35-iii43
Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors. 相似文献