全文获取类型
收费全文 | 22922篇 |
免费 | 1993篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 227篇 |
儿科学 | 813篇 |
妇产科学 | 532篇 |
基础医学 | 2905篇 |
口腔科学 | 428篇 |
临床医学 | 2709篇 |
内科学 | 4474篇 |
皮肤病学 | 304篇 |
神经病学 | 1807篇 |
特种医学 | 1126篇 |
外国民族医学 | 1篇 |
外科学 | 2903篇 |
综合类 | 541篇 |
一般理论 | 11篇 |
预防医学 | 2340篇 |
眼科学 | 861篇 |
药学 | 1534篇 |
中国医学 | 19篇 |
肿瘤学 | 1446篇 |
出版年
2022年 | 142篇 |
2021年 | 385篇 |
2020年 | 217篇 |
2019年 | 389篇 |
2018年 | 461篇 |
2017年 | 340篇 |
2016年 | 360篇 |
2015年 | 452篇 |
2014年 | 598篇 |
2013年 | 819篇 |
2012年 | 1195篇 |
2011年 | 1233篇 |
2010年 | 700篇 |
2009年 | 683篇 |
2008年 | 1133篇 |
2007年 | 1211篇 |
2006年 | 1157篇 |
2005年 | 1070篇 |
2004年 | 1085篇 |
2003年 | 1022篇 |
2002年 | 981篇 |
2001年 | 557篇 |
2000年 | 583篇 |
1999年 | 524篇 |
1998年 | 298篇 |
1997年 | 299篇 |
1996年 | 266篇 |
1995年 | 253篇 |
1994年 | 230篇 |
1993年 | 237篇 |
1992年 | 418篇 |
1991年 | 428篇 |
1990年 | 409篇 |
1989年 | 419篇 |
1988年 | 367篇 |
1987年 | 348篇 |
1986年 | 355篇 |
1985年 | 341篇 |
1984年 | 249篇 |
1983年 | 203篇 |
1982年 | 166篇 |
1981年 | 144篇 |
1980年 | 147篇 |
1979年 | 184篇 |
1978年 | 146篇 |
1977年 | 153篇 |
1976年 | 126篇 |
1975年 | 120篇 |
1974年 | 134篇 |
1973年 | 137篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
M G Bartels C K Varley J Mitchell S J Stamm 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(1):100-103
Electrocardiograms were evaluated in 39 children and adolescents before and after the clinical use of imipramine and desipramine. The average increase in PR interval was 0.01 seconds. The PR interval increased by 0.02 seconds in 11 subjects, and a new first-degree atrioventricular block developed in two subjects. These changes were not related to the choice between imipramine and desipramine, the dose, or the method of administration. An increase in PR interval by 0.02 seconds or more did correlate with having an abnormality disclosed on a pretreatment electrocardiogram. The average increase in PR interval was 0.007 seconds for subjects with normal baseline electrocardiograms and 0.019 seconds for subjects with conduction and nonconduction abnormalities disclosed in baseline tracings. None of the electrocardiogram changes resulted in adverse clinical consequences. 相似文献
22.
Alexis A Gintowt Jeffrey J Germer P Shawn Mitchell Joseph D C Yao 《Journal of clinical virology》2005,34(2):155-157
BACKGROUND: The current manual sample processing method recommended for use with the TRUGENE HBV Genotyping Kit (TRUGENE HBV; Bayer HealthCare LLC, Tarrytown, NY) is labor-intensive and may be prone to specimen cross-contamination. Recent evaluations of the MagNA Pure LC (MP; Roche Applied Science, Indianapolis, IN) suggest that it is suitable for automated, contamination-free extraction and purification of viral nucleic acids from large-volume (1.0 mL) serum or plasma specimens. OBJECTIVES: We evaluated the MP Total Nucleic Acid Isolation Kit--Large Volume (Roche Applied Science) in conjunction with TRUGENE HBV to establish the analytical sensitivity (threshold titer) of the assay, in HBV DNA International Units (IU)/mL, for obtaining consistent, interpretable sequence data from TRUGENE HBV. STUDY DESIGN: HBV analytical standards, prepared as 10 replicates (1.0 mL each) at each of the following concentrations: 200, 1000, 5000, and 10,000 IU/mL, were processed by MP and analyzed by TRUGENE HBV according to manufacturer's instructions. Performance of TRUGENE HBV used in conjunction with MP sample processing was evaluated further using 22 clinical serum specimens containing low titers of HBV DNA. RESULTS: All replicates of HBV analytical standards at 1000, 5000, and 10,000 IU/mL yielded interpretable TRUGENE HBV sequences, whereas interpretable sequences were obtained in 90% (9 of 10) of the replicates at 200 IU/mL. TRUGENE HBV sequences were interpretable in 86% (19 of 22) of the clinical specimens studied. CONCLUSIONS: MP sample processing is efficient and suitable for use with TRUGENE HBV. When combined with MP sample processing, TRUGENE HBV yielded interpretable sequences from HBV analytical standards and clinical serum specimens with HBV DNA titers of > or =200 IU/mL. 相似文献
23.
24.
Diane C. Mitchell Author Vitae Frank R. LawrenceAuthor Vitae Terryl J. HartmanAuthor Vitae Julianne M. CurranAuthor Vitae 《Journal of the American Dietetic Association》2009,109(5):909-913
The US Department of Agriculture's MyPyramid guidelines introduced a near doubling of the dietary recommendations for vegetables. These recommendations target specific subgroups of vegetables, including dry beans and peas. Dry beans and peas provide an array of nutrients and phytochemicals that have been shown to have beneficial health effects, yet consumption levels in the United States are quite low. Few studies have examined the influence of legume consumption on nutrient intakes. Therefore, the purpose of this study was to assess nutrient and food group intakes of dry bean and pea consumers compared to nonconsumers. Dietary intake data from the 1999-2002 National Health and Nutrition Examination Survey for adults aged ≥19 years was used. Results show that on any given day only 7.9% of adults are consuming dry beans and peas; Mexican Americans or other Hispanics are more likely to be consumers than nonconsumers. Consuming approximately ½ c dry beans or peas resulted in higher intakes of fiber, protein, folate, zinc, iron, and magnesium with lower intakes of saturated fat and total fat. These data support the specific recommendation for dry beans and peas as part of the overall vegetable recommendation. Increased consumption of dry beans and peas—economical and nutrient-rich foods—could improve the diet quality of Americans. 相似文献
25.
26.
Safety and efficacy of bariatric surgery: Longitudinal Assessment of Bariatric Surgery 总被引:3,自引:0,他引:3
Steven H. Belle Ph.D. M.Sc.Hyg. Paul D. Berk M.D. Anita P. Courcoulas M.D. M.P.H. F.A.C.S. David R. Flum M.D. M.P.H. F.A.C.S. Carolyn W. Miles Ph.D. James E. Mitchell M.D. Walter J. Pories M.D. F.A.C.S. Bruce M. Wolfe M.D. F.A.C.S. Susan Z. Yanovski M.D. Longitudinal Assessment of Bariatric Surgery Consortium Writing Group 《Surgery for obesity and related diseases》2007,3(2):116-126
27.
R G O'Donnell L León Vintró G J Duffy P I Mitchell 《Applied radiation and isotopes》2004,60(2-4):539-542
The levels of residual radioactivity induced in Havar foils at the entrance of a high-pressure 18O-enriched water target used for the production of 18F- in a medical cyclotron with 16 MeV protons have been determined using high-resolution gamma-ray spectrometry. Whole body and skin dose rates arising from exposure to these foils during their periodic replacement have been estimated. The results indicate that irradiated foils do not represent a significant radiological hazard for the cyclotron operating staff and that no waste disposal difficulties should be encountered after an appropriate 'cooling' period of 2 years. 相似文献
28.
29.
Richard Frazee M.D. Glennon Einspanier D.O. Mitchell S. Wachtel M.D. Eldo E. Frezza M.D. M.B.A. F.A.C.S. 《Surgery for obesity and related diseases》2007,3(2):191-175
BACKGROUND: Gastric bypass is an established bariatric procedure that has undergone multiple modifications to improve its effectiveness. The side-to-side stapled technique is well recognized, but closure of the gastrotomy/enterotomy by the stapler can potentially narrow the Roux limb. Because of this, many surgeons will hand suture the closure of the gastrotomy/enterotomy. To obviate this difficulty, we inserted the linear stapler from the stomach's greater curvature, using a double-stapled anastomosis that minimized the need for hand suturing. METHODS: We performed a retrospective analysis of 307 patients undergoing this technique for laparoscopic gastric bypass. The weight loss and 30-day morbidity and mortality were tabulated and compared with those in other published series. RESULTS: Of the 307 patients, none died postoperatively. The overall 30-day morbidity rate was 15%. Two leaks from the gastrojejunostomy and 2 from the jejunojejunostomy (1.2%) developed. The mean percentage of excess weight loss was 34% at 3 months, 52% at 6 months, 73% at 1 year, 71% at 2 years, and 69% at 3 years. CONCLUSION: The greater curve approach avoids Roux limb obstruction, minimizes the need for hand suturing, and uses standard trocar incisions. Our short-term follow-up results are similar to those of series of other techniques. 相似文献
30.