全文获取类型
收费全文 | 14134篇 |
免费 | 874篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 85篇 |
儿科学 | 244篇 |
妇产科学 | 239篇 |
基础医学 | 1944篇 |
口腔科学 | 436篇 |
临床医学 | 1821篇 |
内科学 | 2786篇 |
皮肤病学 | 273篇 |
神经病学 | 1152篇 |
特种医学 | 709篇 |
外科学 | 2028篇 |
综合类 | 89篇 |
一般理论 | 2篇 |
预防医学 | 1212篇 |
眼科学 | 244篇 |
药学 | 838篇 |
1篇 | |
中国医学 | 34篇 |
肿瘤学 | 909篇 |
出版年
2023年 | 99篇 |
2022年 | 97篇 |
2021年 | 236篇 |
2020年 | 172篇 |
2019年 | 228篇 |
2018年 | 307篇 |
2017年 | 268篇 |
2016年 | 265篇 |
2015年 | 248篇 |
2014年 | 389篇 |
2013年 | 552篇 |
2012年 | 704篇 |
2011年 | 763篇 |
2010年 | 398篇 |
2009年 | 373篇 |
2008年 | 627篇 |
2007年 | 630篇 |
2006年 | 593篇 |
2005年 | 517篇 |
2004年 | 513篇 |
2003年 | 450篇 |
2002年 | 427篇 |
2001年 | 367篇 |
2000年 | 453篇 |
1999年 | 385篇 |
1998年 | 180篇 |
1997年 | 144篇 |
1996年 | 127篇 |
1995年 | 135篇 |
1994年 | 120篇 |
1993年 | 114篇 |
1992年 | 322篇 |
1991年 | 329篇 |
1990年 | 328篇 |
1989年 | 280篇 |
1988年 | 261篇 |
1987年 | 293篇 |
1986年 | 270篇 |
1985年 | 219篇 |
1984年 | 210篇 |
1983年 | 184篇 |
1982年 | 108篇 |
1981年 | 86篇 |
1980年 | 73篇 |
1979年 | 127篇 |
1978年 | 91篇 |
1977年 | 85篇 |
1975年 | 80篇 |
1974年 | 75篇 |
1973年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Ordinary surgical rubber gloves are penetrated by methylmethacrylate monomer (MMA) in less than 1 minute, as demonstrated by gas chromatographic measurements. A three-layered PVP glove, 0.07 mm thick - consisting of an outer layer of polyethylene, an intermediary layer of ethylene vinyl alcohol copolymer, and an inner layer of polyethylene - was impervious for 20 minutes, whereas a viton-butyl rubber glove, 0.27 mm thick, was impervious for 15 minutes.
The PVP glove is recommended to orthopedic surgeons, nurses, and other handling acrylic bone cements to avoid sensitization, and is especially recommended to persons with known contact allergy to MMA. 相似文献
The PVP glove is recommended to orthopedic surgeons, nurses, and other handling acrylic bone cements to avoid sensitization, and is especially recommended to persons with known contact allergy to MMA. 相似文献
93.
Cerebrospinal fluid A beta42 is increased early in sporadic Alzheimer's disease and declines with disease progression 总被引:7,自引:0,他引:7
Jensen M Schröder J Blomberg M Engvall B Pantel J Ida N Basun H Wahlund LO Werle E Jauss M Beyreuther K Lannfelt L Hartmann T 《Annals of neurology》1999,45(4):504-511
All mutations known to cause familial Alzheimer's disease (AD) act by increasing the levels of soluble beta-amyloid peptide (A beta), especially the longer form, A beta42. However, in vivo elevation of soluble A beta in sporadic AD has so far not been shown. In the present study, we used enzyme-linked immunosorbent assays specific for A beta42 and A beta40 to investigate cerebrospinal fluid from sporadic AD at different stages of disease severity, to clarify the roles of A beta42 and A beta40 during disease progression. We also evaluated three other groups--one group of patients with mild cognitive impairment who were at risk of developing dementia, a cognitively intact, nondemented reference group diagnosed with depression, and a perfectly healthy control group. We found that A beta42 is strongly elevated in early and mid stages of AD, and thereafter it declines with disease progression. On the contrary, A beta40 levels were decreased in early and mid stages of AD. The group of cognitively impaired patients and the depression reference group had significantly higher levels of A beta42 than the healthy control group, implying that A beta42 is increased not only in AD, but in other central nervous system conditions as well. Our data also point out the importance of having thoroughly examined control material. The initial increase and subsequent decrease of A beta42 adds a new biochemical tool to follow the progression of AD and might be important in the monitoring of therapeutics. 相似文献
94.
Rikke H Dahlrot Steinbj?rn Hansen Stine S Jensen Henrik D Schr?der Jacob Hjelmborg Bjarne W Kristensen 《International journal of clinical and experimental pathology》2014,7(7):3739-3751
Cancer stem cell-related (CSC) markers have been suggested to have promising potentials as novel types of prognostic and predictive markers in gliomas. However no single CSC-related marker is currently used in clinical decisions. The aim of this study was to investigate the prognostic value of CD133 and nestin separately and in combination using a novel quantitative approach in a well-characterized population-based cohort of glioma patients. The expression of CD133 and nestin was measured by systematic random sampling in stained paraffin sections from 239 glioma patients diagnosed between 2005 and 2009. We found that the expression of CD133 did not correlate with WHO grade, and there was no association with overall survival (OS). The level of nestin correlated positively with WHO grade. In patients with WHO grade II tumors, a high level of nestin was associated with short progression-free survival (PFS) in multivariate analysis. High levels of co-localization were associated with poor PFS in patients with WHO grade II tumors, but not with OS. We conclude that CD133 was not an independent prognostic factor, but a high level of nestin was associated with poor PFS in patients with WHO grade II tumors. The combination of double-immunofluorescence and automated analysis seems to be a feasible and reproducible approach for investigation of the prognostic potential of biomarkers. 相似文献
95.
96.
Nissen N Gravholt CH Abrahamsen B Hauge EM Jensen JE Mosekilde L Brixen K 《Clinical endocrinology》2007,67(6):897-903
Objective Patients with Turner syndrome (TS) have altered growth and increased risk of osteoporosis due to oestrogen deficiency and possibly a host of other factors. Thus, TS patients have a 4·9‐fold increased risk of femoral neck fractures. Most patients are treated with oestrogen during puberty and adolescence to facilitate pubertal development and prevent secondary osteoporosis. The geometry of the hip is a predictor for hip fractures independent of bone mineral density (BMD). The purpose of the present study was to investigate the variation of the geometry of the hip in patients with TS in comparison with healthy controls. Patients The study population comprised 58 patients with TS (aged 22–67 years) and 60 age‐matched healthy women (aged 21–65 years). Measurements Hip axis length (HAL), neck width (NW), neck shaft angle (NSA), and femoral head‐radius (HR) on dual‐energy X‐ray absorptiometry (DXA) screen images. These parameters related to age of oestrogen supplementation, menarche, and duration of oestrogen exposure. Results Height was 146·6 ± 6·9 cm and 167·1 ± 6·2 cm (P < 0·1) and weight 57·4 ± 13·9 kg and 62·3 ± 8·3 kg (P < 0·001) in patients and controls, respectively. After adjustment for differences in height, HAL was not significantly different (9·4 ± 0·5 vs. 9·5 ± 0·5 cm; NS) in TS compared with controls while NW was significantly increased (3·5 ± 0·4 cm vs. 3·3 ± 0·2 cm, P < 0·001), NSA was similar (129 ± 4°vs. 130 ± 4°, NS), and HR was significantly decreased (4·1 ± 0·4 vs. 4·5 ± 0·3 cm, P < 0·001). The duration of oestrogen exposure was significantly shorter among TS, but did not correlate significantly with the geometrical parameters in either TS or controls. Conclusion Our data demonstrates that hip geometry is disproportionate in TS compared with normal controls. The altered hip geometry, however, cannot explain the increased risk of hip fracture in TS. 相似文献
97.
Jensen JD Hartmann H de Mul A Schuit A Brug J;ENERGY Consortium 《Nutrition reviews》2011,69(11):660-674
The aim of the present review was to examine the existing literature on the effectiveness of economic incentives for producing sound nutritional behavior in schools. Studies published in the English-language literature that included baseline and/or outcome data regarding food and beverage intake of schoolchildren were eligible for inclusion. A systematic search of the literature was conducted to identify relevant primary studies and relevant systematic reviews of primary studies. Altogether, 3,472 research publications were identified in the systematic search, of which 50 papers were retrieved. Of these, 30 publications representing 28 studies fulfilled the criteria for inclusion. The studies addressing price incentives suggest that such incentives are effective for altering consumption in the school setting. Other types of economic incentives have been included in combined intervention schemes, but the inclusion of other intervention elements makes it difficult to draw conclusions about the effectiveness of the economic incentive instruments per se in these studies. 相似文献
98.
99.
Sandra E. File S. Pellow L. H. Jensen 《Journal of neural transmission (Vienna, Austria : 1996)》1986,65(2):103-114
Summary The effects of the-carboline ZK 93426, a putative benzodiazepine receptor antagonist, were investigated in the social interaction test of anxiety and in the holeboard. Like the receptor antagonist Ro 15-1788, ZK 93426 (2.5–10 mg/kg) caused a specific reduction in social interaction (interpreted as an anxiogenic effect) and caused a significant elevation in exploratory head-dipping (5 mg/kg). When low (ineffective) doses of both compounds (1 mg/kg ZK 93426; 4 mg/kg Ro 15-1788) were administered together they significantly reduced social interaction. No further reductions in social interaction were observed when effective doses of both compounds (5 mg/kg ZK 93426; 10 mg/kg Ro 15-1788) were tested in combination; it is likely that this is due to almost total benzodiazepine receptor occupancy at effective doses of either compound. When doses of each compound (5 mg/kg ZK 93426; 10 mg/kg Ro 15-1788) that resulted in stimulation of head-dipping were examined in combination, the elevation in exploration was no longer observed. Since at higher doses of both compounds there is an attenuation of the elevation in head-dipping, it is again likely that the effects of the two compounds are additive. 相似文献
100.