全文获取类型
收费全文 | 204936篇 |
免费 | 2743篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 1372篇 |
儿科学 | 7679篇 |
妇产科学 | 3891篇 |
基础医学 | 19834篇 |
口腔科学 | 1916篇 |
临床医学 | 17988篇 |
内科学 | 35625篇 |
皮肤病学 | 992篇 |
神经病学 | 19327篇 |
特种医学 | 9449篇 |
外国民族医学 | 1篇 |
外科学 | 31530篇 |
综合类 | 2597篇 |
现状与发展 | 1篇 |
一般理论 | 50篇 |
预防医学 | 22276篇 |
眼科学 | 3159篇 |
药学 | 11167篇 |
中国医学 | 656篇 |
肿瘤学 | 18268篇 |
出版年
2023年 | 183篇 |
2022年 | 276篇 |
2021年 | 587篇 |
2020年 | 422篇 |
2019年 | 660篇 |
2018年 | 22584篇 |
2017年 | 17806篇 |
2016年 | 20039篇 |
2015年 | 1540篇 |
2014年 | 1739篇 |
2013年 | 2296篇 |
2012年 | 9121篇 |
2011年 | 23215篇 |
2010年 | 19916篇 |
2009年 | 12550篇 |
2008年 | 21478篇 |
2007年 | 23874篇 |
2006年 | 2712篇 |
2005年 | 4272篇 |
2004年 | 5307篇 |
2003年 | 6201篇 |
2002年 | 4271篇 |
2001年 | 468篇 |
2000年 | 574篇 |
1999年 | 425篇 |
1998年 | 560篇 |
1997年 | 503篇 |
1996年 | 327篇 |
1995年 | 369篇 |
1994年 | 304篇 |
1993年 | 264篇 |
1992年 | 165篇 |
1991年 | 217篇 |
1990年 | 253篇 |
1989年 | 184篇 |
1988年 | 152篇 |
1987年 | 131篇 |
1986年 | 113篇 |
1985年 | 131篇 |
1984年 | 142篇 |
1983年 | 146篇 |
1982年 | 168篇 |
1981年 | 139篇 |
1980年 | 157篇 |
1979年 | 58篇 |
1978年 | 78篇 |
1977年 | 64篇 |
1974年 | 57篇 |
1938年 | 60篇 |
1932年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 340 毫秒
51.
Lucy Yardley David Papo Adolfo Bronstein Michael Gresty Mark Gardner Nilli Lavie Linda Luxon 《Neuropsychologia》2002,40(4):373-383
The aim of this series of experiments was to determine whether attention is normally required for continuously processing vestibular information concerning orientation, or is required only when orientation is disrupted (eg by vestibular dysfunction or by conflicting visual and vestibular orientation cues). In the first two studies, healthy subjects were passively oscillated, and indicated when they perceived they were passing through their starting position. There was only weak evidence for interference between performance on this 'continuous orientation monitoring task' and on concurrent mental tasks. However, a third study showed that when patients with vestibular imbalance carried out the continuous orientation monitoring task their performance on a concurrent mental arithmetic task was substantially impaired. This dual task interference was correlated with inaccuracy in judging orientation on the continuous orientation monitoring task, which in turn correlated with severity of recent vestibular symptomatology (assessed by questionnaire). In a fourth experiment, disorientation was induced in healthy subjects by rotating the visual field about the line of sight. Bidirectional interference was observed between monitoring orientation (assessed by accuracy in setting a rod to the perceived vertical) and performance of an arithmetic task. Dual task interference was correlated with baseline levels of disorientation induced by the visual field, as indicated by inaccuracy in judging the visual vertical. These findings suggest that monitoring orientation makes significant demands upon cortical processing resources when disorientation is induced, whether the disorientation results from deficient sensory functioning or from ambiguous perceptual information. 相似文献
52.
53.
54.
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
55.
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
56.
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
57.
58.
59.
Pilar Nicolás 《Hereditary cancer in clinical practice》2007,5(3):144-152
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing. 相似文献
60.
Multivitamin and alcohol intake and folate receptor alpha expression in ovarian cancer. 总被引:2,自引:0,他引:2
Linda E Kelemen Thomas A Sellers Gary L Keeney Wilma L Lingle 《Cancer epidemiology, biomarkers & prevention》2005,14(9):2168-2172
Folate receptor alpha (FRalpha) expression in epithelial ovarian cancer may be related to folate intake. We examined this association using multivitamin intake, a proxy for folic acid, and assessed whether the relation was modified by alcohol intake, a folate agonist. Cases (n = 148) with suspected epithelial ovarian cancer, of ages > or = 20 years, were seen at Mayo Clinic, Minnesota, between 2000 and 2004; those with tumor specimens (n = 108) were included in analyses. Outpatient controls (n = 148) without cancer and with at least one ovary intact were matched to cases by age (within 5 years) and state of residence. Multivitamin (> or = 4 pills/wk) and weekly alcohol (> or = 5 drinks) intakes were assessed. Tumor specimens were analyzed immunohistochemically for FRalpha. Multivariable rate ratios (RR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression. In case-control analysis, the RRs of multivitamin intake with absent/weak/moderate and strong-expressing FRalpha tumors were 0.30 (95% CI, 0.12-0.70) and 0.47 (95% CI, 0.24-0.91), respectively. For alcohol, the associations were 0.84 (95% CI, 0.24-2.86) and 1.65 (95% CI, 0.69-3.93), respectively. In case-case analysis, the RR associated with developing strong-expressing versus other FRalpha tumors was 3.13 (95% CI, 1.14-8.65) for multivitamins and 1.58 (95% CI, 0.45-5.60) for alcohol. The data did not support evidence for an interaction between multivitamin and alcohol intake with risk of developing a strong-expressing FRalpha tumor. The association of multivitamin intake with ovarian cancer may depend on FRalpha expression level. 相似文献