全文获取类型
收费全文 | 1076205篇 |
免费 | 71853篇 |
国内免费 | 1366篇 |
专业分类
耳鼻咽喉 | 15027篇 |
儿科学 | 34631篇 |
妇产科学 | 28652篇 |
基础医学 | 153670篇 |
口腔科学 | 29705篇 |
临床医学 | 95041篇 |
内科学 | 203960篇 |
皮肤病学 | 24403篇 |
神经病学 | 81498篇 |
特种医学 | 42994篇 |
外国民族医学 | 201篇 |
外科学 | 163259篇 |
综合类 | 21707篇 |
现状与发展 | 1篇 |
一般理论 | 263篇 |
预防医学 | 74718篇 |
眼科学 | 24550篇 |
药学 | 86207篇 |
7篇 | |
中国医学 | 2805篇 |
肿瘤学 | 66125篇 |
出版年
2019年 | 7772篇 |
2018年 | 11313篇 |
2017年 | 8929篇 |
2016年 | 10110篇 |
2015年 | 11275篇 |
2014年 | 15292篇 |
2013年 | 22247篇 |
2012年 | 30608篇 |
2011年 | 32352篇 |
2010年 | 18983篇 |
2009年 | 17844篇 |
2008年 | 30026篇 |
2007年 | 32125篇 |
2006年 | 32765篇 |
2005年 | 31098篇 |
2004年 | 29780篇 |
2003年 | 28603篇 |
2002年 | 27575篇 |
2001年 | 60066篇 |
2000年 | 61499篇 |
1999年 | 50974篇 |
1998年 | 12463篇 |
1997年 | 11016篇 |
1996年 | 11030篇 |
1995年 | 10330篇 |
1994年 | 9346篇 |
1993年 | 8864篇 |
1992年 | 37824篇 |
1991年 | 36301篇 |
1990年 | 35781篇 |
1989年 | 34328篇 |
1988年 | 30897篇 |
1987年 | 30022篇 |
1986年 | 28249篇 |
1985年 | 26465篇 |
1984年 | 19212篇 |
1983年 | 16128篇 |
1982年 | 8830篇 |
1979年 | 17066篇 |
1978年 | 11424篇 |
1977年 | 10240篇 |
1976年 | 8849篇 |
1975年 | 10088篇 |
1974年 | 11663篇 |
1973年 | 11290篇 |
1972年 | 10763篇 |
1971年 | 10107篇 |
1970年 | 9266篇 |
1969年 | 8944篇 |
1968年 | 7927篇 |
排序方式: 共有10000条查询结果,搜索用时 3 毫秒
971.
972.
Similar dose responsiveness of hepatic glycogenolysis and gluconeogenesis to glucagon in vivo 总被引:6,自引:0,他引:6
R W Stevenson K E Steiner M A Davis G K Hendrick P E Williams W W Lacy L Brown P Donahue D B Lacy A D Cherrington 《Diabetes》1987,36(3):382-389
This study was undertaken to determine whether the dose-dependent effect of glucagon on gluconeogenesis parallels its effect on hepatic glycogenolysis in conscious overnight-fasted dogs. Endogenous insulin and glucagon secretion were inhibited by somatostatin (0.8 micrograms X kg-1 X min-1), and intraportal replacement infusions of insulin (213 +/- 28 microU X kg-1 X min-1) and glucagon (0.65 ng X kg-1 X min-1) were given to maintain basal hormone concentrations for 2 h (12 +/- 2 microU/ml and 108 +/- 23 pg/ml, respectively). The glucagon infusion was then increased 2-, 4-, 8-, or 12-fold for 3 h, whereas the rate of insulin infusion was left unchanged. Glucose production (GP) was determined with 3-[3H]glucose, and gluconeogenesis (GNG) was assessed with tracer (U-[14C]alanine conversion to [14C]glucose) and arteriovenous difference (hepatic fractional extraction of alanine, FEA) techniques. Increases in plasma glucagon of 53 +/- 8, 199 +/- 48, 402 +/- 28, and 697 +/- 149 pg/ml resulted in initial (15-30 min) increases in GP of 1.1 +/- 0.4 (N = 4), 4.9 +/- 0.5 (N = 4), 6.5 +/- 0.6 (N = 6), and 7.7 +/- 1.4 (N = 4) mg X kg-1 X min-1, respectively; increases in GNG (approximately 3 h) of 48 +/- 19, 151 +/- 50, 161 +/- 25, and 157 +/- 7%, respectively; and increases in FEA (3 h) of 0.14 +/- 0.07, 0.37 +/- 0.05, 0.42 +/- 0.04, and 0.40 +/- 0.17, respectively. In conclusion, GNG and glycogenolysis were similarly sensitive to stimulation by glucagon in vivo, and the dose-response curves were markedly parallel. 相似文献
973.
974.
M K Hordinsky 《Dermatologic Clinics》1987,5(3):483-489
The evaluation of the patient with alopecia is a multistep process that comprises obtaining a good medical history, performing the clinical examination with a special emphasis on the examination of cut and plucked hair, doing a scalp biopsy, and ordering appropriate laboratory studies. Genetic counseling may be given if it is requested. 相似文献
975.
976.
Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP. 相似文献
977.
978.
979.
980.
A 68-year-old man had subacute cerebellar degeneration and a non-Hodgkin's lymphoma. Using an immunoblotting method, we found serum antibodies to rat cerebral 250-kd and 110-kd and cerebellar 110-kd acidic cytoplasmic proteins. The antibodies did not react unless the antigens were prepared soon after death with protease inhibitors. Two hundred fifty-kd and 110-kd proteins are minor components of soluble cytoplasmic proteins of the brain. The molecular weights differed from other soluble brain-specific proteins already characterized. 相似文献