全文获取类型
收费全文 | 1512篇 |
免费 | 92篇 |
国内免费 | 113篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 77篇 |
妇产科学 | 13篇 |
基础医学 | 186篇 |
口腔科学 | 22篇 |
临床医学 | 188篇 |
内科学 | 352篇 |
皮肤病学 | 49篇 |
神经病学 | 78篇 |
特种医学 | 370篇 |
外国民族医学 | 1篇 |
外科学 | 57篇 |
综合类 | 41篇 |
预防医学 | 75篇 |
眼科学 | 12篇 |
药学 | 102篇 |
中国医学 | 3篇 |
肿瘤学 | 89篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2016年 | 22篇 |
2015年 | 20篇 |
2014年 | 21篇 |
2013年 | 42篇 |
2012年 | 19篇 |
2011年 | 38篇 |
2010年 | 47篇 |
2009年 | 55篇 |
2008年 | 41篇 |
2007年 | 75篇 |
2006年 | 42篇 |
2005年 | 65篇 |
2004年 | 29篇 |
2003年 | 22篇 |
2002年 | 22篇 |
2001年 | 28篇 |
2000年 | 34篇 |
1999年 | 34篇 |
1998年 | 94篇 |
1997年 | 97篇 |
1996年 | 110篇 |
1995年 | 64篇 |
1994年 | 61篇 |
1993年 | 67篇 |
1992年 | 17篇 |
1991年 | 31篇 |
1990年 | 28篇 |
1989年 | 49篇 |
1988年 | 45篇 |
1987年 | 49篇 |
1986年 | 34篇 |
1985年 | 50篇 |
1984年 | 22篇 |
1983年 | 17篇 |
1982年 | 29篇 |
1981年 | 20篇 |
1980年 | 32篇 |
1979年 | 10篇 |
1978年 | 14篇 |
1977年 | 17篇 |
1976年 | 27篇 |
1975年 | 15篇 |
1972年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有1717条查询结果,搜索用时 31 毫秒
91.
92.
Ayala Espinosa MJ Pérez-Santonja JJ Alió Y Sanz JL Artola Roig A Cardona Ausina C 《Archivos de la Sociedad Espa?ola de Oftalmología》2000,75(12):835-837
CASE REPORT: We present a case of traumatic displacement of corneal flap in the superior temporal quadrant 13 days after LASIK. The flap was repositioned after gentle irrigation of BSS, cleaned the interface and then drying the flap to verify its stability. In the next day the flap was adhered, clear cornea,smooth and visual acuity without correction was 1.00. DISCUSSION: We should try immediately to reposition the flap after traumatic displacement, as in this case. 相似文献
93.
94.
Herrador Montiel A Sánchez Vicente JL Sánchez Vicente P 《Archivos de la Sociedad Espa?ola de Oftalmología》2000,75(10):697-700
PURPOSE/METHODS: We report a 34-year-old woman with sytemic lupus erythematosus (S.L.E.) and antiphospholipidic syndrome which presented severe ischaemic retinopathy and neovascular proliferation. RESULTS/CONCLUSIONS: We achieved no progression of the disease and stabilization of visual acuity with panphotocoagulation. We recommend periodic ophtalmologic exams because of the scarce symptomatology. 相似文献
95.
An International Collaborative Study involving 12 laboratories in 7 different countries was undertaken in order to replace the 1st International Standard (IS) for Fibrinogen, Plasma (89/644). The candidate replacement standard was the ampouled and freeze-dried residue of solvent/detergent treated plasma and was calibrated as coded duplicates (A and B) versus the 1st IS Fibrinogen, Plasma by automated Clauss assay and by a recommended clot collection (gravimetric) assay. This latter method had been used to calibrate the 1st IS Fibrinogen, Plasma. Comparing the ratios of the potency estimates of sample A to sample B (the coded duplicates), all of the laboratories obtained a ratio within 5% of the expected value of 1.0 by automated Clauss assay, which suggests that the laboratories were able to perform this assay well. Scrutiny of the data obtained from the gravimetric assays revealed that in almost all cases the results were invalid. The results of these assays are included in this report but clearly should be treated with caution and indeed produced significantly lower mean estimates of potency than the other assay methods. The overall geometric mean of all estimates of potency of the proposed 2nd IS Fibrinogen, Plasma (98/612) is 2.19 mg/ampoule by the automated Clauss assay. These data have been presented to the Fibrinogen Sub-Committee of the Standardisation and Scientific Committee (SSC) of the International Society on Thrombosis and Haemostasis (ISTH) (Washington, DC, August 1999), which recommended the establishment of 98/612 as the 2nd IS Fibrinogen, Plasma. This report has been presented to the Expert Committee on Biological Standardisation of the World Health Organisation (ECBS-WHO) at their 1999 session and 98/612 was established as the 2nd IS Fibrinogen, Plasma with a potency of 2.2 mg/ampoule. 相似文献
96.
Picture storybooks and starting school 总被引:1,自引:0,他引:1
This paper reports an investigation of children's picture storybooks about school. Previous research has indicated that parents and educators choose to read books about school to children as a way of helping children become familiar with school expectations. Drawing on over 100 children's picture storybooks, the content (text and illustrations) of these books has been analysed according to categories established through the Starting School Research Project, enabling a comparison of the issues raised by children and the issues addressed in picture storybooks. 相似文献
97.
98.
背景:在亚洲、非洲和欧洲,致病性H5N1流感病毒引起禽流感在家禽和候鸟中爆发流行,还导致了人类发病和死亡。虽然目前H5N1毒株引起人与人之间的传染不太可能,但它仍可能是未来流感大范围流行的潜在威胁因素。本试验的目的就是评价针对H5N1病毒株的裂解病毒疫苗的安全性和免疫原性。方法:对300名志愿者(年龄为18岁~40岁)进行随机、开放标签的、无对照的Ⅰ期试验。300名志愿者被分为6组:7.5mg血凝素加佐剂组(n=50)、7.5mg血凝素不加佐剂组(n=49)、15mg血凝素加佐剂组(n=50)、15mg血凝素不加佐剂组(n=50)、30mg血凝素加佐剂组(n=51)、30mg血… 相似文献
99.
Elizabeth M Poole Jeannette Bigler John Whitton Justin G Sibert John D Potter Cornelia M Ulrich 《Cancer epidemiology, biomarkers & prevention》2006,15(3):502-508
Prostacyclin synthase (PGIS) and arachidonate 5-lipoxygenase (ALOX5) are enzymes relevant to prostaglandin and leukotriene synthesis, both important pathways for colon cancer risk. We hypothesized that genetic variation altering the function of these enzymes would modify risk of colorectal polyps. In a Minnesota-based case-control study of adenomatous (n = 517) or hyperplastic (n = 192) polyps versus polyp-free controls (n = 618), we investigated the role of promoter repeat polymorphisms in PGIS and ALOX5 as well as ALOX5 -1700 G>A. Having fewer than six repeats on both PGIS alleles (<6R/<6R) was associated with an increased risk of adenomas compared with the 6R/6R (wild-type) genotype (OR, 1.90; 95% CI, 1.09-3.30). Having more repeats (>6R/> or =6R) reduced risk (OR, 0.73; 95% CI, 0.40-1.35; P(trend) = 0.03). In allele-based analyses, fewer repeats were associated with a modestly increased risk of adenomas and perhaps hyperplastic polyps. There were no risk differences for either the ALOX5 VNTR or -1700 G>A polymorphisms. Associations with regular use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) differed by PGIS genotype. Among individuals with at least one wild-type allele, NSAID use was associated with a decreased risk; however, those with fewer PGIS repeats (<6R/<6R) did not benefit (P(interaction) = 0.06). There was also evidence of an interaction between the COX-2 -765 G>C and ALOX5 -1700 G>A genotypes (P(interaction) = 0.07). The PGIS promoter polymorphism may affect risk of colorectal polyps and modify the effects of NSAID use on polyp risk. A more comprehensive investigation of genetic variability in prostaglandin synthesis in relation to risk of colorectal neoplasia and NSAID pharmacogenetics is warranted. 相似文献
100.
Predictors of smoking initiation and cessation among childhood cancer survivors: a report from the childhood cancer survivor study. 总被引:7,自引:0,他引:7
Karen Emmons Frederick P Li John Whitton Ann C Mertens Raymond Hutchinson Lisa Diller Leslie L Robison 《Journal of clinical oncology》2002,20(6):1608-1616
PURPOSE: To examine the determinants of smoking behavior among participants in the Childhood Cancer Survivors Study (CCSS). METHODS: This retrospective cohort survey study was conducted among 9,709 childhood cancer survivors. Main outcomes included smoking initiation and cessation. RESULTS: Twenty-eight percent of patients reported ever smoking and 17% reported being current smokers. Standardized to United States population rates, the observed to expected (O/E) ratios and corresponding 95% confidence limits (95% CL) of cigarette smoking were 0.72 (95% CL, 0.69, 0.75) among all survivors and 0.71 (95% CL, 0.68 to 0.74) and 0.81 (95% CL, 0.70, 0.93) among whites and nonwhites, respectively. Significantly lower O/E ratios were present among both males (O/E, 0.73) and females (O/E, 0.70). Factors independently associated with a statistically significant relative risk of smoking initiation included older age at cancer diagnosis, lower household income, less education, not having had pulmonary-related cancer treatment, and not having had brain radiation. Blacks were less likely to start smoking. Survivors who smoked were significantly more likely to quit (O/E, 1.22; 95% CL, 1.15, 1.30). Among ever-smokers, factors associated with the likelihood of being a current smoker included age less than 13 years at smoking initiation, less education, and having had brain radiation; those age less than 3 years at cancer diagnosis were significantly more likely to be ex-smokers. CONCLUSIONS: Although survivors in the CCSS cohort seem to be smoking at rates below the general population, interventions are needed to prevent smoking initiation and promote cessation in this distinct population. 相似文献