全文获取类型
收费全文 | 194421篇 |
免费 | 2689篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 1272篇 |
儿科学 | 7307篇 |
妇产科学 | 3292篇 |
基础医学 | 19042篇 |
口腔科学 | 1849篇 |
临床医学 | 14362篇 |
内科学 | 34520篇 |
皮肤病学 | 952篇 |
神经病学 | 18203篇 |
特种医学 | 9672篇 |
外科学 | 31632篇 |
综合类 | 2639篇 |
一般理论 | 34篇 |
预防医学 | 20153篇 |
眼科学 | 3098篇 |
药学 | 10784篇 |
2篇 | |
中国医学 | 649篇 |
肿瘤学 | 17694篇 |
出版年
2023年 | 173篇 |
2022年 | 250篇 |
2021年 | 577篇 |
2020年 | 370篇 |
2019年 | 523篇 |
2018年 | 22402篇 |
2017年 | 17736篇 |
2016年 | 19902篇 |
2015年 | 1442篇 |
2014年 | 1488篇 |
2013年 | 1686篇 |
2012年 | 8331篇 |
2011年 | 22339篇 |
2010年 | 19626篇 |
2009年 | 12169篇 |
2008年 | 20670篇 |
2007年 | 22791篇 |
2006年 | 1662篇 |
2005年 | 3300篇 |
2004年 | 4401篇 |
2003年 | 5273篇 |
2002年 | 3291篇 |
2001年 | 585篇 |
2000年 | 701篇 |
1999年 | 405篇 |
1998年 | 381篇 |
1997年 | 352篇 |
1996年 | 256篇 |
1995年 | 237篇 |
1994年 | 206篇 |
1993年 | 185篇 |
1992年 | 242篇 |
1991年 | 279篇 |
1990年 | 285篇 |
1989年 | 218篇 |
1988年 | 193篇 |
1987年 | 183篇 |
1986年 | 142篇 |
1985年 | 171篇 |
1984年 | 124篇 |
1983年 | 116篇 |
1982年 | 102篇 |
1980年 | 81篇 |
1979年 | 73篇 |
1978年 | 65篇 |
1976年 | 62篇 |
1974年 | 66篇 |
1970年 | 60篇 |
1938年 | 61篇 |
1932年 | 59篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
31.
杨娅 Thomas Bartel Loredana Latina Guido Caspari 王新房 Raimund Erbel 《华中科技大学学报(医学英德文版)》2002,22(2):158-163
Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re… 相似文献
32.
33.
Alex N. Bullock Julia Henckel Brian S. DeDecker Christopher M. Johnson Penka V. Nikolova Mark R. Proctor David P. Lane Alan R. Fersht 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(26):14338-14342
Some 50% of human cancers are associated with mutations in the core domain of the tumor suppressor p53. Many mutations are thought just to destabilize the protein. To assess this and the possibility of rescue, we have set up a system to analyze the stability of the core domain and its mutants. The use of differential scanning calorimetry or spectroscopy to measure its melting temperature leads to irreversible denaturation and aggregation and so is useful as only a qualitative guide to stability. There are excellent two-state denaturation curves on the addition of urea that may be analyzed quantitatively. One Zn2+ ion remains tightly bound in the holo-form of p53 throughout the denaturation curve. The stability of wild type is 6.0 kcal (1 kcal = 4.18 kJ)/mol at 25°C and 9.8 kcal/mol at 10°C. The oncogenic mutants R175H, C242S, R248Q, R249S, and R273H are destabilized by 3.0, 2.9, 1.9, 1.9, and 0.4 kcal/mol, respectively. Under certain denaturing conditions, the wild-type domain forms an aggregate that is relatively highly fluorescent at 340 nm on excitation at 280 nm. The destabilized mutants give this fluorescence under milder denaturation conditions. 相似文献
34.
Jeff Anglen Peter Steven Apostoles Gordon Christensen Barry Gainor Joel Lane 《Journal of orthopaedic research》1996,14(2):251-254
We examined the efficacy of various irrigation solutions delivered through a power irrigator to remove bacteria from three different surfaces. Titanium, stainless-steel, and cortical bone surfaces were coated with three different bacterial species: Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. They were then irrigated with 1 L of fluid delivered by jet lavage. The fluids tested were normal saline and solutions of bacitracin, neomycin, and soap. One set of specimens was not irrigated, as a control. After irrigation, the specimens were sonicated to remove residual bacteria, and the sonicate was quantitatively cultured to allow evaluation of the amount of residual bacteria on the surface. The results showed that removal of bacteria reflects an interaction between bacterial species, surface characteristics, and irrigation solution. Fewer bacteria were present in all the irrigation groups than in the control. Soap solution was as good as or better than any other solution at removing all three types of bacteria from all three surfaces, although not all of the pairwise comparisons were statistically significant. There was a significant advantage to soap solution over antibiotic irrigant or saline alone in removing Staphylococcus epidermidis from metallic surfaces. The use of a soap solution for irrigation seems to improve the removal of some bacteria from some surfaces in this experimental model and may represent a better type of irrigation additive. 相似文献
35.
Irwin L. Flink 《Brain structure & function》2002,205(3):235-244
36.
Alpha-adrenoreceptor reagents. 4. Resolution of some potent selective prejunctional alpha 2-adrenoreceptor antagonists 总被引:1,自引:0,他引:1
A P Welbourn C B Chapleo A C Lane P L Myers A G Roach C F Smith M R Stillings I F Tulloch 《Journal of medicinal chemistry》1986,29(10):2000-2003
The resolution of three 2-substituted derivatives of idazoxan is described. The enantiomers show large separations in activity in a variety of in vitro and in vivo tests, and the active isomers are all potent and selective antagonists at the alpha 2-adrenoreceptor. The significance of these results in relation to those published on the enantiomers of idazoxan and to those on optically active alpha 2-adrenoreceptor agonists is discussed. 相似文献
37.
38.
39.
40.
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