全文获取类型
收费全文 | 38023篇 |
免费 | 3896篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 225篇 |
儿科学 | 1168篇 |
妇产科学 | 1031篇 |
基础医学 | 5282篇 |
口腔科学 | 736篇 |
临床医学 | 4796篇 |
内科学 | 6806篇 |
皮肤病学 | 583篇 |
神经病学 | 3378篇 |
特种医学 | 1459篇 |
外国民族医学 | 3篇 |
外科学 | 4856篇 |
综合类 | 794篇 |
一般理论 | 50篇 |
预防医学 | 4732篇 |
眼科学 | 917篇 |
药学 | 2843篇 |
中国医学 | 47篇 |
肿瘤学 | 2246篇 |
出版年
2022年 | 305篇 |
2021年 | 708篇 |
2020年 | 398篇 |
2019年 | 665篇 |
2018年 | 703篇 |
2017年 | 539篇 |
2016年 | 590篇 |
2015年 | 623篇 |
2014年 | 869篇 |
2013年 | 1298篇 |
2012年 | 1930篇 |
2011年 | 1875篇 |
2010年 | 1104篇 |
2009年 | 979篇 |
2008年 | 1737篇 |
2007年 | 1788篇 |
2006年 | 1807篇 |
2005年 | 1711篇 |
2004年 | 1645篇 |
2003年 | 1521篇 |
2002年 | 1427篇 |
2001年 | 1223篇 |
2000年 | 1231篇 |
1999年 | 1063篇 |
1998年 | 450篇 |
1997年 | 405篇 |
1996年 | 373篇 |
1995年 | 309篇 |
1994年 | 342篇 |
1993年 | 331篇 |
1992年 | 829篇 |
1991年 | 798篇 |
1990年 | 778篇 |
1989年 | 681篇 |
1988年 | 709篇 |
1987年 | 652篇 |
1986年 | 604篇 |
1985年 | 666篇 |
1984年 | 542篇 |
1983年 | 426篇 |
1982年 | 271篇 |
1981年 | 286篇 |
1980年 | 256篇 |
1979年 | 464篇 |
1978年 | 350篇 |
1977年 | 258篇 |
1976年 | 271篇 |
1974年 | 288篇 |
1973年 | 261篇 |
1972年 | 269篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
The effect of cigarette smoking on ovarian function and early pregnancy outcome of in vitro fertilization treatment 总被引:3,自引:0,他引:3
A retrospective analysis of the results of the first attempt at in vitro fertilization (IVF) treatment in 447 couples was performed by chart review. In 124 couples the female partners smoked cigarettes, and in 236 couples they did not. A total of 69 pregnancies (19.2%) were achieved, 50 in nonsmokers (21.2% per cycle), and 19 in smokers (15.3% per cycle). There were no significant differences in these cycles between the two groups in peak estradiol level achieved, the number of eggs retrieved, fertilization rate, or implantation rate. The incidence of spontaneous abortion was higher in smokers (42.1%) than in nonsmokers (18.9%). Consequently, the delivery rate per cycle of IVF was significantly lower in the smoking group (11 of 124, 9.6%) than in the nonsmokers (40 of 236, 17.0%). There was no effect when only the husband was a smoker. From these data, smoking appears to significantly reduce the chances of successful pregnancy after IVF treatment. 相似文献
64.
65.
C van Kerckhove L Luyrink J Taylor H Melin-Aldana K Balakrishnan W Maksymowych M Elma D Lovell E Choi D N Glass 《The Journal of rheumatology》1991,18(6):874-879
To further investigate a clinical impression that patients with early onset pauciarticular juvenile rheumatoid arthritis (EOPA-JRA) who carry HLA-DQw1 have more severe arthritis, we subtyped HLA-DQw1 in American midwestern patients with EOPA-JRA. The HLA-DQA1*0101 subtype was present in 10 of 19 patients who developed persistent polyarticular erosive disease compared with 18 of 92 healthy controls (chi 2 = 9.13, p = 0.003, RR = 4.6), and occurred more frequently in this polyarticular group than in patients without polyarticular erosive disease (chi 2 = 4.11, p = 0.040, RR = 3.0). The presence of HLA-DQA1*0101 was significantly lower in patients with chronic iridocyclitis than in patients without chronic iridocyclitis (chi 2 = 7.07, p = 0.008, RR = 0.21). In HLA-DQA1*0101 positive patients, DNA sequences of the beta-1 domain of the HLA-DQ alpha and HLA-DQ beta genes (HLA-DQA1*0101, HLA-DQB1*0501 and HLA-DQB1*0503) were identical to those in controls. In this midwestern EOPA-JRA population, HLA-DQA1*0101 or genes in linkage disequilibrium with it, are associated with a cohort of patients with EOPA-JRA with distinct clinical characteristics. 相似文献
66.
Two patients with acutely thrombosed femorofemoral bypass grafts are presented. Recombinant human tissue-type plasminogen activator (rt-PA) was used successfully in thrombolysis of the occluded grafts. Utilizing a new technique the grafts were punctured directly and bolus doses of rt-PA administered. 相似文献
67.
J E Taylor R A MacTier I S Henderson J J Belch W K Stewart 《Peritoneal dialysis international》1992,12(2):221-226
OBJECTIVE: To determine the effect of subcutaneous erythropoietin treatment on dialysis efficiency in continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Dialysis efficiency, platelet and white cell aggregation, and red cell deformability were measured monthly for six months in nine anaemic CAPD patients treated with erythropoietin, and on a single occasion in seven control CAPD patients with intrinsically high haemoglobin concentrations. SETTING: Renal dialysis unit. PATIENTS: Nine patients stable on CAPD for a minimum of six months and with haemoglobin concentrations less than 8.5 g/dl were treated with erythropoietin. Seven CAPD patients matched for age and renal function, with haemoglobins greater than 9.0 g/dl served as controls. RESULTS: Daily peritoneal clearances and net ultrafiltration volumes were unchanged when haematocrit increased from 25.0 +/- 2.2% to 36.5 +/- 3.5%. Spontaneous whole blood platelet aggregation was significantly increased from week twelve (pre-treatment aggregation 46 +/- 23%; 12 weeks: 67 +/- 19%, p less than 0.05; 16 weeks: 64 +/- 19%, p less than 0.01; 20 weeks: 71 +/- 16%, p less than 0.01; 24 weeks: 73 +/- 10%, p less than 0.01). CONCLUSIONS: The increase in haematocrit and platelet aggregation associated with erythropoietin treatment did not affect peritoneal clearances or ultrafiltration capacity. 相似文献
68.
This article describes how genetic components of disease susceptibility can be evaluated in case-control studies, where cases and controls are sampled independently from the population at large. Subjects are assumed unrelated, in contrast to studies of familial aggregation and linkage. The logistic model can be used to test collapsibility over phenotypes or genotypes, and to estimate interactions between environmental and genetic factors. Such interactions provide an example of a context where non-hierarchical models make sense biologically. Also, if the exposure and genetic categories occur independently and the disease is rare, then analyses based only on cases are valid, and offer better precision for estimating gene-environment interactions than those based on the full data. 相似文献
69.
David M. Kelley Alan Lichtenstein Jianyi Wang Anna N. Taylor Steven M. Dubinett 《Immunopharmacology and immunotoxicology》1994,16(2):139-148
Previous studies have suggested that corticotropin-releasing factor (CRF) has immunoregulatory effects in addition to its neuroendocrine role. We examined the ability of CRF to inhibit lipopolysaccharide (LPS)-induced pulmonary vascular leak in vivo. Female BALB/C mice were treated with either normal saline (NS) or CRF prior to injection with LPS. Pulmonary vascular leak was inhibited by CRF as assessed by measurement of lung wet-to-dry ratios. The stress-induced increase in serum corticosterone levels in mice injected with LPS alone was not further increased by treatment with CRF. This indicates that the effect of CRF was not mediated centrally by stimulation of endogenous steroid release. Histologic examination of the lungs revealed that leukocyte infiltration was significantly depressed in CRF-treated mice thus confirming the protective effect of CRF. In addition, a modest prolongation of survival was demonstrated in CRF-treated mice following challenge with LPS (p=.08). These data indicate the potential utility of CRF as a modulator of pulmonary vascular leak. 相似文献
70.
Iliac-vessel injury from total hip arthroplasty is associated with hemorrhagic complications and an increased death rate. The authors identified seven patients who had severe medial displacement of the acetabular prosthesis and associated vascular injury to the iliac vessels after total hip replacement. One patient had two hip replacements. Preoperative findings included a pelvic mass (three hips), pelvic pain (eight), radiologic evidence of cement in the pelvis (three) and the acetabular prosthesis in the pelvis (eight), computed tomographic evidence of cement in the pelvis and proximity of the prosthesis to the iliac vessels (four), and arteriography showing displacement or compression of the iliac vessels (seven). Operative management in all cases involved medial exposure, mobilization and repair of the iliac vessels before revision of the hip prosthesis. Postoperative complications were deep vein thrombosis (three), in spite of prophylaxis, and occlusion of a vein interposition graft (one) requiring placement of a femoral crossover graft. There were no deaths, amputations or hemorrhagic complications. The authors advocate preoperative identification of patients who have iliac-vessel involvement by their total hip prosthesis and initial medial extraperitoneal exposure and repair of these vessels before removal of the displaced acetabular prosthesis. 相似文献