全文获取类型
收费全文 | 731篇 |
免费 | 38篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 30篇 |
妇产科学 | 12篇 |
基础医学 | 72篇 |
口腔科学 | 20篇 |
临床医学 | 72篇 |
内科学 | 191篇 |
皮肤病学 | 8篇 |
神经病学 | 36篇 |
特种医学 | 83篇 |
外科学 | 61篇 |
综合类 | 9篇 |
预防医学 | 43篇 |
眼科学 | 9篇 |
药学 | 65篇 |
肿瘤学 | 67篇 |
出版年
2022年 | 8篇 |
2021年 | 21篇 |
2020年 | 19篇 |
2019年 | 26篇 |
2018年 | 22篇 |
2017年 | 12篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 26篇 |
2013年 | 30篇 |
2012年 | 34篇 |
2011年 | 35篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 18篇 |
2007年 | 25篇 |
2006年 | 20篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 20篇 |
2002年 | 11篇 |
2001年 | 15篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 21篇 |
1997年 | 12篇 |
1996年 | 15篇 |
1995年 | 15篇 |
1994年 | 20篇 |
1993年 | 18篇 |
1992年 | 18篇 |
1991年 | 20篇 |
1990年 | 20篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 15篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1966年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有784条查询结果,搜索用时 0 毫秒
91.
Barra JA Bezon E Mondine P Resk A Gilard M Boshat J 《The Annals of thoracic surgery》2000,70(5):1541-1545
BACKGROUND: Surgical coronary artery reconstruction for diffuse coronary disease is described and assessed. METHODS: A long arteriotomy, internal thoracic artery graft, and exclusion of atheromatous plaques from the coronary lumen are the bases of the technique. One hundred eighteen reconstructions were performed in 108 patients with a mean age of 59 years. Stable angina was present in 62% of patients and unstable angina in 22%. Sixteen percent had had a recent myocardial infarction. The reconstructions involved 94 left anterior descending coronary arteries, 17 marginal, 5 diagonal, and 2 right coronary arteries. RESULTS: The perioperative mortality rate was 3.7% (4 patients). The rate of perioperative myocardial infarction was 6.3%. Mean follow-up was 29 months (standard deviation, 10 months). Two patients were lost to follow-up. Ninety patients were free from angina and cardiac-related events. Five patients sustained a myocardial infarction, 3 were in congestive heart failure, 3 had class II angina, and 1 died of stroke. Seventy-four of the surgical coronary artery reconstructions have been angiographically evaluated (29 months): 94.6% of the internal thoracic artery grafts were completely patent, and 70 of the reconstructions were patent without restenosis. String signs and occlusions were present in two internal thoracic arteries each. CONCLUSIONS: This technique allows revascularization of severely and diffusely diseased coronary arteries with encouraging results. 相似文献
92.
93.
94.
E Bidoli S Franceschi R Talamini S Barra C La Vecchia 《International journal of cancer. Journal international du cancer》1992,50(2):223-229
The relation between dietary factors and the risk of colorectal cancer was investigated in a case-control study conducted in Pordenone province, North-eastern Italy, on 123 cases of colon cancer, 125 of rectal cancer and 699 controls admitted to hospital for acute, non-neoplastic or digestive disorders. Consistent positive associations were observed with more frequent consumption of bread (odds ratio, OR = 2.1 for colon and 2.2 for rectum for highest vs. lowest tertile), polenta (OR = 2.1 for colon, 1.9 for rectum), cheese (OR = 1.7 for colon, 1.8 for rectum) and eggs (2.5 for colon, 1.9 for rectum), whereas reduced ORs were observed in subjects reporting more frequent consumption of tomatoes (OR = 0.5 for colon and 0.4 for rectum). High consumption of margarine exerted a significant protection against cancer of the colon whereas high consumption of carrot spinach, whole-grain bread and pasta (favorably) and red meat (unfavorably) affected rectal cancer risk in particular. Thus the present study gives support for a protective effect associated with a fiber-rich or vegetable-rich diet, while it indicates that frequent consumption of refined starchy foods, eggs and fat-rich foods such as cheese and red meat is a risk factor for colo-rectal cancer. 相似文献
95.
Various antigenic activities of polyoma virus-transformed and embryonic mouse cells were retained after 3M KCl solubilization of surface components. Particularly, transplantation antigen (TSTA) demonstrated by homograft rejection, and surface (S) antigen, detected by inhibition of immunofluorescence on polyoma-virus-transformed mouse cells, could be demonstrated. The crude soluble extracts were partially purified by salting out with (NH4)2SO4. In the case of polyoma-virus-transformed cells, TSTA and a part of S antigen activity were found in the same fraction (60% (NH4)2SO4 saturation) while another part of S antigen was salted out at 80% saturation. By chromatography, S antigen activity was found in 2 zones for transformed cells and in one zone for embryonic cells. One of these zones was common to both cell extracts. 相似文献
96.
97.
A polymer system was developed for use in permanent inflation of detachable balloons, to avoid long-term reliance on the integrity of balloon shells or valve mechanisms. This system is based on 2-hydroxy-ethyl methacrylate (HEMA) as the monomer, in combination with a cross-linking agent and a water-soluble curing system. The low-viscosity, hydrophilic mixture can be exchanged through a small-bore catheter into a detachable balloon and polymerizes in 40-60 minutes at body temperature. Partially polymerized HEMA can cause vascular occlusion; hence, careful timing of balloon detachment is required. The evolution of the radiographic appearance of HEMA-filled balloons is predictable. The balloons remain radiopaque on plain radiographs as long as the balloon shell and valve mechanisms are competent. After rupture of the shell or failure of the valve mechanism, the balloons become invisible on plain radiographs but remain hyperattenuating on computed tomography scans. 相似文献
98.
GB Winter 《Archives of disease in childhood》1983,58(7):485-487
99.
100.
Francesco Bossa Giovanni Polidoro Donatella Barra Anna Liverzani Roberto Scandurra 《Chemical biology & drug design》1976,8(5):499-501
The sequence around the coenzyme-binding lysine of mitochondrial aspartate aminotransferase from beef kidney was determined. The holoenzyme was treated with NaB3H4 and digested with thermolysin; the labelled peptide was isolated and its sequence proved to be identical with sequences around the coenzyme site from the same isoenzyme of different organs and animals (pig heart and sheep liver). The sequences of the phosphopyridoxyl peptides of the mitochondrial aspartate aminotransferases appear to be closely related to the corresponding peptides from the cytoplasmic isoenzymes. 相似文献