全文获取类型
收费全文 | 81781篇 |
免费 | 5927篇 |
国内免费 | 3700篇 |
专业分类
耳鼻咽喉 | 349篇 |
儿科学 | 1478篇 |
妇产科学 | 849篇 |
基础医学 | 13020篇 |
口腔科学 | 1663篇 |
临床医学 | 6869篇 |
内科学 | 14271篇 |
皮肤病学 | 1026篇 |
神经病学 | 7726篇 |
特种医学 | 1307篇 |
外国民族医学 | 15篇 |
外科学 | 4792篇 |
综合类 | 13892篇 |
现状与发展 | 22篇 |
预防医学 | 4754篇 |
眼科学 | 961篇 |
药学 | 10489篇 |
9篇 | |
中国医学 | 2574篇 |
肿瘤学 | 5342篇 |
出版年
2024年 | 130篇 |
2023年 | 829篇 |
2022年 | 1951篇 |
2021年 | 2971篇 |
2020年 | 2381篇 |
2019年 | 2050篇 |
2018年 | 2016篇 |
2017年 | 2332篇 |
2016年 | 2658篇 |
2015年 | 3005篇 |
2014年 | 5064篇 |
2013年 | 5664篇 |
2012年 | 5364篇 |
2011年 | 5993篇 |
2010年 | 4744篇 |
2009年 | 4605篇 |
2008年 | 4736篇 |
2007年 | 4597篇 |
2006年 | 4123篇 |
2005年 | 3879篇 |
2004年 | 3173篇 |
2003年 | 2703篇 |
2002年 | 2068篇 |
2001年 | 1781篇 |
2000年 | 1541篇 |
1999年 | 1320篇 |
1998年 | 1222篇 |
1997年 | 1072篇 |
1996年 | 918篇 |
1995年 | 730篇 |
1994年 | 699篇 |
1993年 | 586篇 |
1992年 | 505篇 |
1991年 | 473篇 |
1990年 | 394篇 |
1989年 | 310篇 |
1988年 | 295篇 |
1987年 | 286篇 |
1986年 | 255篇 |
1985年 | 361篇 |
1984年 | 317篇 |
1983年 | 210篇 |
1982年 | 244篇 |
1981年 | 191篇 |
1980年 | 164篇 |
1979年 | 109篇 |
1978年 | 91篇 |
1977年 | 77篇 |
1976年 | 67篇 |
1975年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
181.
Hisashi Ozasa 《Artificial organs》1994,18(10):768-770
Abstract: Extraction of adsorbed proteins from dialysis membranes that had been used during actual hemodialysis procedures was performed. The condition of extraction with SDS plus 2–mercaptoethanol at 95°C is more efficient than with only PBS or with SDS solution without 2–mercaptoethanol at 37°C. 相似文献
182.
构建玻片蛋白质芯片的实验研究 总被引:2,自引:0,他引:2
目的:探讨玻片蛋白质芯片的构建方法及其中间操作条件的选择与优化。方法:利用生物芯片点样仪将超微量蛋白质点到经特殊处理的玻璃片表面,然后选用不同的化学试剂对玻片背景进行封闭;再用荧光素标记的蛋白质与点样蛋白杂交;最后用生物芯片分析仪扫描成像并进行分析,比较不同条件下芯片的显示效果。结果:蛋白质样品与片基稳定结合,并保持原活性状态;封闭试剂选用酪蛋白或明胶效果较佳;点样探针与其特异蛋白质抗体可稳定结合,结合效果与点样蛋白浓度在一定范围内呈正相关;在1.6 cm×1.6 cm的玻璃片面积上,构建了36×36=1269点的蛋白质芯片。结论:本实验条件下,蛋白质抗原或抗体可以稳定地固定于经过处理的玻璃片表面.制成免疫型蛋白芯片,并可通过随后的抗原抗体反应与荧光素标记的相应抗体或抗原结合,用生物芯片分析仪可对其荧光信号进行检测分析。 相似文献
183.
Li Ming Yang Jing Shen Guan-xin Zhang Qian Liu Shen-pei Liu Zhong-bei Ye Wei-xin 《华中科技大学学报(医学英德文版)》1994,14(4):209-212
Summary T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro. Several interfering factors were also discussed. The
result indicated that lymphocyte activation and proliferation are calciumdependent. A rise of cytoplasmic free Ca2+ quickly following activation with CD3 McAb is mainly due to intracellular mobilization of Ca2+, while lymphocyte proliferation needs both intracellular mobilization of Ca2+ as well as influx of extracellular Ca2+. It was confirmed that CTX sensitive G protein plays a role in regulating T cell proliferation by pretreatment with CTX suppressing
lymphocyte3H-TdR incorporation obviously. PLC and PKC inhibitor neomycin and P. S. S could also decrease T cell proliferation. 相似文献
184.
185.
R. HENKEL T. STALF N. MERTENS W. MISKA W.-B. SCHILL 《International journal of andrology》1994,17(2):68-73
The outer dense fibres are accessory fibres in the spermatozoon. They represent up to 30% of the protein portion in human spermatozoa and are involved in sperm progressive motility. If outer dense fibres are missing or developed poorly, spermatozoa are only locally motile. For isolation of the outer dense fibres, human spermatozoa were sonicated at 25 kHz and the flagella were separated by density gradient centrifugation in Percoll. Thereafter, membranes and fibrous sheath were dissolved under reducing conditions in the cationic detergent cetyltrimethylammonium bromide for 30, 60 and 90 min, respectively. The isolation steps were monitored by phase contrast microscopy and electron microscopy. After SDS-polyacrylamide gel electrophoresis and silver staining of isolated outer dense fibres, two protein bands at 55 and 67 kDa could be detected. By means of rhodamine B staining, no phosphorus could be detected in the outer dense fibre proteins. 相似文献
186.
187.
1. Evidence that vegetarian dietary patterns lower blood pressure (BP) comes from both population studies and randomized controlled trials in normotensive and hypertensive subjects. 2. The effect has been shown most clearly in those who keep to a strict lacto-ovo vegetarian diet characterized by a relatively low intake of saturated fat, a high polyunsaturated/saturated fat ratio, and a high intake of fruit, vegetables and other fibre containing products. Randomized controlled dietary trials suggest the effects are independent of dietary sodium, additive to that of calorie restriction, and not due to the absence of meat protein per se. Indeed, recent population studies suggest an inverse relationship between dietary protein and BP. 4. Dietary fats, fibre, potassium, magnesium and calcium do not independently seem to account for the effects. A possible role for complex carbohydrate in conjunction with the other dietary factors has yet to be fully explored. 相似文献
188.
189.
A. MacDonald 《Journal of human nutrition and dietetics》1994,7(2):105-114
This article is a report of a meeting of dietitians held on 15 September 1992 in Birmingham to discuss the recommendations of a 'Medical Research Council Working Party on the Dietary Management of Phenylketonuria'. (Contributions on the day of the meeting came from Judith Houghton, Eleanor Weetch, Isabel Smith, Sheena Laing, Ruth Watling, John Walter, Rodney Pollitt.) 相似文献
190.
D. M. F. Edwards C. Pellizzoni H. P. Breuel A. Berardi M. G. Castelli E. Frigerio I. Poggesi M. Rocchetti A. Dubini M. Strolin Benedetti 《Biopharmaceutics & drug disposition》1995,16(6):443-460
The pharmacokinetics of reboxetine, a new antidepressant agent, were found to be close to linear in a crossover study comparing administration of single 2, 3, 4 and 5 mg capsule doses in 15 healthy male volunteers, and in the same study the capsules were bioequivalent to the proposed therapeutic tablet formulation (4mg). Kinetic analysis was based on HPLC assay of reboxetine in plasma and urine collected up to 72 h after each administration. Plasma levels indicated a rapid absorption (tmax?2h) and an elimination half-life of about 13 h. Clearance and volume of distribution were modest (ratios to bioavailability: CL/F?29 mL min?1; Vz/F?32L); urinary excretion was ~9% of dose, corresponding to a renal clearance of only 3 mL min?1 (a value consistent with the rate of glomerular filtration of unbound drug). In vitro, binding to plasma proteins, estimated from radioactivity levels following dialysis of 14C-labelled reboxetine, appeared to be dominated by α1-acid glycoprotein without marked saturation up to plasma concentrations of over 500 ng mL?1 (2.8–3.1% unbound with human plasma from three additional volunteers; 1.8–2.0% for 2gL?1 orosomucoid α1-acid glycoprotein, and 46.4–47.4% for 40 gL?1 albumin), whilst the mean Cmax in the current study was much lower (164 ng mL?1 after a 5 mg dose). 相似文献