全文获取类型
收费全文 | 794篇 |
免费 | 42篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 34篇 |
妇产科学 | 9篇 |
基础医学 | 80篇 |
口腔科学 | 12篇 |
临床医学 | 60篇 |
内科学 | 162篇 |
皮肤病学 | 15篇 |
神经病学 | 44篇 |
特种医学 | 160篇 |
外科学 | 70篇 |
综合类 | 32篇 |
预防医学 | 45篇 |
眼科学 | 4篇 |
药学 | 86篇 |
中国医学 | 6篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 12篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 14篇 |
2017年 | 4篇 |
2016年 | 25篇 |
2015年 | 53篇 |
2014年 | 27篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 31篇 |
2010年 | 36篇 |
2009年 | 30篇 |
2008年 | 24篇 |
2007年 | 11篇 |
2006年 | 16篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 24篇 |
1997年 | 42篇 |
1996年 | 33篇 |
1995年 | 29篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1970年 | 5篇 |
排序方式: 共有846条查询结果,搜索用时 15 毫秒
51.
52.
INTESTINAL AGANGLIONOSIS IN THE SMITH-LEMLI-OPITZ SYNDROME 总被引:2,自引:0,他引:2
J. IKA J. MAREOVÁ Z. KEREKE Z. NOIKA V. JÜTTNEROVÁ P. BALÍCEK 《Acta paediatrica (Oslo, Norway : 1992)》1983,72(1):141-143
ABSTRACT. Two unrelated cases with clinical and autopsy findings of the Smith-Lemli-Opitz syndrome are described. Narrowing of the terminal ileum and congenital intestinal aganglionosis was found in both. This is a rare association and the importance of microscopic examination of the intestine in cases of the Smith-Lemli-Opitz syndrome is emphasized. 相似文献
53.
Curi MA Skelly CL Quint C Meyerson SL Farmer AJ Shakur UM Loth F Schwartz LB 《The Journal of surgical research》2002,108(2):191-197
BACKGROUND: Many investigators have measured outflow resistance (R) following peripheral bypass procedures, but correlations with graft patency have been weak. This is because the primary determinants of graft patency are the size and quality of the conduit, not its outflow bed. Efforts at separating conduit resistance from outflow resistance have been unsuccessful. Recently, the concept of longitudinal impedance ( integral Z(L)) has been suggested as a measure of conduit resistance independent of outflow resistance. The purpose of this in vitro experiment was to test the hypothesis that integral Z(L) is independent of R within physiologically relevant ranges. METHODS: Rigid polyethylene tubing of known internal diameter and length (4.3 mm, 375 cm) was perfused with a glycerin/saline mixture mimicking the viscosity of blood (4.1 cp), utilizing a variable pulsatile pump and Windkessel, with outflow into multiply branched tubes of decreasing diameter simulating the hemodynamic conditions of arterial bypass. Flow and pressure were measured using ultrasonic transit time and catheter transduction, respectively, and waveforms digitized at 200 Hz. Flow was varied while maintaining "systemic" pressure and resistance. After Fourier transformation, integral Z(L) was calculated as deltaP/Q at each harmonic and integrated over 4 Hz. RESULTS: integral Z(L) calculations were remarkably reproducible within the same day with a coefficient of variation (CV) = 4.0% (at 100 dyne. s/cm(5); n = 4) or over 4 successive days (CV = 4.3%). Furthermore, integral Z(L) was largely independent of R over the physiologic range tested, with integral Z(L) remaining relatively constant as R was increased sixfold. CONCLUSION: integral Z(L) is a consistent and reproducible measure of conduit resistance independent of R over a wide physiologic range. It may be useful for measuring the adequacy of bypass graft conduits. 相似文献
54.
血府逐瘀汤对乳鼠心肌细胞缺血再灌注损伤的影响 总被引:4,自引:0,他引:4
目的为探讨血府逐瘀汤对乳鼠心肌细胞缺血再灌注损伤的影响。方法应用培养的乳鼠心肌细胞造成缺血再灌注损伤的动物模型,观察心肌细胞中超氧化物岐化酶(SOD)的水平,推断细胞内活性氧的生成量;观察培养液中乳酸脱氢酶(LDH)活性改变以判断细胞损伤情况;并进行DNA琼脂糖凝胶电泳及末端脱氧核苷酸介导的脱氧尿苷三磷酸缺口末端标记法(TUNEL),以判断细胞死亡类型及程度。结果血府逐瘀汤可显著升高缺血再灌注时SOD的水平,显著降低LDH的水平。DNA电泳图谱表明:血府逐瘀汤可使DNA的拖尾基本消失;TUNEL显示血府逐瘀汤可显著减少缺血再灌注所致的心肌细胞死亡。结论血府逐瘀汤有保护缺血再灌注时心肌细胞免于死亡之功效。 相似文献
55.
NC de Bruin KA van Velthoven M de Ridder T Stijnen RE Juttmann HJ Degenhart HK Visser 《Archives of disease in childhood》1996,74(5):386-399
Data on body composition in conjunction with reference centiles are helpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during this important period of rapid growth. Total body fat (TBF) and fat-free mass (FFM) were estimated from total body electrical conductivity (TBEC) measurements in 423 healthy term Caucasian infants, aged 14-379 days. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Centiles were calculated using Altman's method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBEC derived anthropometric prediction equations for TBF and FFM are available to be used in conjunction with these standards. Regression equations for the P50 and the residual SD, depending on age, weight, or length, are provided for constructing centile charts and calculating standard deviation scores. 相似文献
56.
57.
KM FOCK JY KANG HS NG TM NG KA GWEE CC LIM 《Journal of gastroenterology and hepatology》1995,10(4):379-382
Roxatidine acetate, a new H2 receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25–33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P=NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P=NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine. 相似文献
58.
59.
60.