全文获取类型
收费全文 | 29360篇 |
免费 | 2591篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 321篇 |
儿科学 | 1027篇 |
妇产科学 | 703篇 |
基础医学 | 4120篇 |
口腔科学 | 508篇 |
临床医学 | 3198篇 |
内科学 | 5742篇 |
皮肤病学 | 307篇 |
神经病学 | 2373篇 |
特种医学 | 1098篇 |
外国民族医学 | 3篇 |
外科学 | 3955篇 |
综合类 | 745篇 |
一般理论 | 34篇 |
预防医学 | 2985篇 |
眼科学 | 536篇 |
药学 | 2352篇 |
1篇 | |
中国医学 | 50篇 |
肿瘤学 | 1946篇 |
出版年
2021年 | 462篇 |
2020年 | 283篇 |
2019年 | 490篇 |
2018年 | 512篇 |
2017年 | 372篇 |
2016年 | 427篇 |
2015年 | 496篇 |
2014年 | 768篇 |
2013年 | 1061篇 |
2012年 | 1574篇 |
2011年 | 1686篇 |
2010年 | 877篇 |
2009年 | 799篇 |
2008年 | 1406篇 |
2007年 | 1568篇 |
2006年 | 1511篇 |
2005年 | 1512篇 |
2004年 | 1374篇 |
2003年 | 1286篇 |
2002年 | 1236篇 |
2001年 | 680篇 |
2000年 | 708篇 |
1999年 | 612篇 |
1998年 | 356篇 |
1997年 | 302篇 |
1996年 | 257篇 |
1995年 | 286篇 |
1994年 | 248篇 |
1993年 | 246篇 |
1992年 | 548篇 |
1991年 | 520篇 |
1990年 | 491篇 |
1989年 | 448篇 |
1988年 | 433篇 |
1987年 | 444篇 |
1986年 | 447篇 |
1985年 | 455篇 |
1984年 | 361篇 |
1983年 | 302篇 |
1982年 | 254篇 |
1981年 | 214篇 |
1980年 | 199篇 |
1979年 | 327篇 |
1978年 | 252篇 |
1977年 | 220篇 |
1976年 | 181篇 |
1975年 | 188篇 |
1974年 | 200篇 |
1973年 | 219篇 |
1972年 | 188篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
81.
Sung-Eun Kong Lewis R. Blennerhassett Kathryn A. Heel Rosalie D. McCauley John C. Hall 《ANZ journal of surgery》1998,68(8):554-561
Ischaemia-reperfusion injury (IRI) is of obvious relevance in situations where there is an interruption of blood supply to the gut, as in vascular surgery, or in the construction of free intestinal grafts. It is now appreciated that IRI also underlies the gut dysfunction that occurs in early shock, sepsis, and trauma. The events that occur during IRI are complex. However, recent advances in cellular biology have started to unravel these underlying processes. The aim of this review is to provide an outline of current knowledge on the mechanisms and consequences of IRI. Initially, IRI appears to be mediated by reactive oxygen metabolites and, at a later stage, by the priming and activation of polymorphonuclear neutrophils (PMN). Ischaemia-reperfusion injury can diminish the barrier function of the gut, and can promote an increase in the leakage of molecules (intestinal permeability) or the passage of microbes across the wall of the bowel (bacterial trans-location). Ischaemia-reperfusion injury to the gut can result in the generation of molecules that may also harm distant tissues. 相似文献
82.
83.
84.
85.
86.
M R Ashton A D Postle D E Smith M A Hall 《Archives of disease in childhood. Fetal and neonatal edition》1994,71(2):F114-F117
Objectives - To determine whether dexamethasone `matures' the phosphatidylcholine (PC) composition of broncheoalveolar fluid in infants at high risk of neonatal chronic lung disease (CLD), either by increasing the proportion of dipalmitoylphosphatidylcholine (DPPC), expressed as a percentage of total PC (%DPPC), or by increasing the ratio of DPPC to palmitoyloleoylphosphatidylcholine (DPPC:POPC ratio). 相似文献
87.
P C Chan J Huff J K Haseman J A Quest W Hall 《Japanese journal of cancer research》1992,83(3):258-263
Short-term and long-term carcinogenicity of methyl carbamate (MCB) was evaluated in F344 rats and B6C3F1 mice. In experiments lasting 6, 12, and 18 months, MCB was given in water by gavage to groups of 10 male and 10 female rats at 0 or 400 mg/kg body weight, 5 days per week, and to similar groups of mice at 0 or 1,000 mg/kg. At 6 months, MCB induced atypical mitoses, cytologic alterations, cytomegaly, pigmentation, necrosis, and neoplastic nodules of the liver in rats. At 12 and 18 months, carcinomas of the liver were induced by MCB in 80-90% of male rats and in 60-80% of female rats. None was observed in control rats or in mice. In the 2-year studies, MCB was given to groups of 50 male and 50 female rats at 0, 100, or 200 mg/kg and to similar groups of mice at 0, 500, or 1,000 mg/kg, 5 days/week. Chronic focal inflammation, cytologic alteration, hyperplasia, and neoplastic nodules and carcinomas (200 mg/kg groups only) of the liver were induced by MCB in rats. Liver tumor incidence data for combined experiments in rats were: males--5% in controls, 0% in 100 mg/kg group, 14% in 200 mg/kg group, and 77% in 400 mg/kg group; females--5% in controls, 0% in controls, 0% in 100 mg/kg group, 12% in 200 mg/kg group, and 63% in 400 mg/kg group. MCB was not shown to be carcinogenic in mice. 相似文献
88.
Egidio L. Romano res Soyano Ramón F. Montaño Murray Ratcliffe Marilyn Olson Guillermo Suarez Nelly Martínez and Geoffrey Worstey 《Vox sanguinis》1994,66(3):194-199
Thirteen infants, 10 with A-O and 3 with B-O hemolytic disease of the newborn (ABO-HDN), were treated with synthetic A or B blood group trisaccharides (ATS, BTS) which cause dissociation of maternal antibody bound to infant red cells. The clinical outcome was compared with that of a control group of 21 infants treated with phototherapy during the preceding year. Exchange transfusion was required in 2 out of 13 infants in the experimental group and in 7 in the control group. A randomized prospective controlled study is necessary to confirm these results. 相似文献
89.
Salmonella arizonae are rarely isolated in the UK. Since 1966 there have been sixty-six isolates from humans of whom 35% gave a recent history of foreign travel. Terrapins and snakes are potential sources of infection. 相似文献
90.
Cytokines (IL-1 alpha and IL-2) and soluble interleukin 2 receptors (sIL-2r) were evaluated in patients with rheumatoid arthritis (RA) and controls. In RA, serum sIL-2r and IL-1 alpha were increased, and sIL-2r were significantly higher in synovial fluid than in serum. Serum levels of sIL-1r but not IL-1 alpha were increased in patients with acute infections, suggesting additional discriminatory specificity for IL-1 alpha. Both tender and swollen joint scores were higher for patients with RA with serum sIL-2r levels greater than or equal to 700 U/ml. Quantitation of immune mediators may be useful in the clinical assessment of RA in addition to their implication regarding the pathogenesis of the disease. 相似文献