全文获取类型
收费全文 | 5120篇 |
免费 | 494篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 135篇 |
妇产科学 | 111篇 |
基础医学 | 590篇 |
口腔科学 | 94篇 |
临床医学 | 494篇 |
内科学 | 1010篇 |
皮肤病学 | 68篇 |
神经病学 | 251篇 |
特种医学 | 379篇 |
外科学 | 701篇 |
综合类 | 188篇 |
预防医学 | 468篇 |
眼科学 | 190篇 |
药学 | 407篇 |
中国医学 | 96篇 |
肿瘤学 | 474篇 |
出版年
2023年 | 40篇 |
2022年 | 47篇 |
2021年 | 104篇 |
2020年 | 67篇 |
2019年 | 111篇 |
2018年 | 103篇 |
2017年 | 93篇 |
2016年 | 93篇 |
2015年 | 135篇 |
2014年 | 163篇 |
2013年 | 196篇 |
2012年 | 269篇 |
2011年 | 270篇 |
2010年 | 188篇 |
2009年 | 187篇 |
2008年 | 271篇 |
2007年 | 293篇 |
2006年 | 244篇 |
2005年 | 280篇 |
2004年 | 209篇 |
2003年 | 215篇 |
2002年 | 170篇 |
2001年 | 136篇 |
2000年 | 126篇 |
1999年 | 136篇 |
1998年 | 100篇 |
1997年 | 96篇 |
1996年 | 84篇 |
1995年 | 79篇 |
1994年 | 64篇 |
1993年 | 63篇 |
1992年 | 100篇 |
1991年 | 90篇 |
1990年 | 84篇 |
1989年 | 97篇 |
1988年 | 97篇 |
1987年 | 92篇 |
1986年 | 62篇 |
1985年 | 61篇 |
1984年 | 37篇 |
1983年 | 33篇 |
1982年 | 41篇 |
1981年 | 35篇 |
1980年 | 29篇 |
1979年 | 29篇 |
1978年 | 20篇 |
1977年 | 23篇 |
1976年 | 27篇 |
1975年 | 15篇 |
1972年 | 12篇 |
排序方式: 共有5689条查询结果,搜索用时 15 毫秒
71.
7例尿毒症贫血患者在自发急性缺氧状态下,其血清红细胞生成素(EPO)浓度显著提高(平均7倍),且与PO2呈负相关。缺氧状态纠正后血清EPO浓度下降。提示尿毒症贫血患者的EPO氧依赖调控系统功能尚存在,但处于不敏感的低调状态。进一步了解其机遇,则可能通过促进内源性EPO的生成,有助于悄毒症贫血的治疗。 相似文献
72.
73.
Investigation of nimodipine pharmacokinetics in Chinese patients with acute subarachnoid haemorrhage
C. R. Kumana M. Kou Y. L. Yu K. Y. Fong C. F. Fung C. M. Chang W. Mück I. J. Lauder 《European journal of clinical pharmacology》1993,45(4):363-366
Summary Nimodipine pharmacokinetics was investigated in 12 Chinese patients with acute subarachnoid haemorrhage receiving an IV infusion of 1.6 or 2 mg/h (based on estimated body weight) for 10 days. Peripheral venous blood samples were collected for up to 4 days and plasma nimodipine was assayed by GC/ECD. The mean value was taken as the steady state concentration (Css) and Clearance (CL) (hourly dose/Css) was calculated. Eight survivors were given oral nimodipine (60 or 90 mg) every 6h (based on body weight), blood was sampled over 6 h and the plasma nimodipine level determined. The values for Css, CL and CL·kg–1 were 33.5 g·l–1, 58 l·h–1 and 1.0 l·h–1·kg–1 respectively; in survivors receiving the drug orally, bioavailability of the 30 mg tablet was 9%. In one very sick patient given crushed tablets by naso-gastric tube, the AUC was very low; in vitro studies indicated that adsorption of nimodipine by the tubing was unlikely to have been the cause.The pharmacokinetic findings in Chinese patients are comparable to previously reported values in Caucasians. 相似文献
74.
This paper reports 25 kinds of polyclonal or monoclonal antibodies by ABC immunohistochemical technique used for 253 cell smears by fine-needle aspiration. The results were,1. Immunohistochemical diagnosis were classified into 136 metastatic cancers ( K12 EMA CEA LCA-),92 lymphomas (LCA k12- EMA- CEA-), 4 mesenchymal tumors (Vimentin ), 3 melanomas (S-100 NSE ). 15 reactive proliferations (k λ4 CD CD8 ) and 3 unspecified.2. The origin of 70 metastatic cancers were classified into 36 lung (HLC3-AB ), 4 gastrointestinal tract (MG7 ), 8 thyroid (TGB ), 1 prostate (PSA ), 3 liver (AFP ) and 14 unknown. 3. Immunologic phenotype of 87 lymphomas wereclassified into 66 cases of B-cell, 4 T-cell, 3 hsitocyte, 7 Hodgkin' s diseases and 7 unclear. The above results suggest that immunohistochemlcal method may be used as a new method of diagnosing and differentiating epithelial and non-epithelial tumors, detecting primary focus of metastatic cncer, differentiating between reactive proliferation adn lymphome a 相似文献
75.
76.
目的探讨银杏叶制剂对急性脑梗死的治疗效果。方法随机选择银杏叶制剂配合治疗及常规药物治疗急性脑梗死患者各42例,对不同时期单光子发射电子计算机断层扫描(SPECT)、经颅多普勒超声检查(TCD)及血液流变学进行对比分析。结果银杏叶制剂配合治疗组治愈率及显效率明显高于常规药物治疗组(P<0.01);银杏叶治疗组血液流变学指标全血粘度及血浆粘度均明显降低(P<0.01);SPECT及TCD均示脑缺血病灶有不同程度改善,但常规药物治疗组血液流变学、SPECT、TCD改善均不明显。结论银杏叶制剂治疗急性脑梗死效果显著。 相似文献
77.
0 引言 人类免疫缺陷病毒 (human immunodeficiencyvirus,HIV) - 1编码的反式激活蛋白 TAT具有独特的跨膜运转方式 ,而且有转导速度快 ,效率高的特点 ,被称为蛋白转导结构域 (protein transduction domain,PTD) [1 ,2 ] .本研究用PCR扩增了慢性粒细胞白血病慢粒 bcr/ abl融合蛋白的基因片段 ,在其 5′端融合 PTD结构域的编码区后在大肠杆菌中进行了表达 .表达产物经纯化后 ,加入培养的 HL 6 0细胞 ,表达的蛋白可直接进入细胞内 .这一结果为用外源蛋白负载(L oading)免疫细胞提供了新的途径 .1 材料和方法1.1 DNA重组 人工合… 相似文献
78.
According to the 1990 census, the highly diverse Asian and Pacific Islander (API) American population has doubled in size from 1980 to 1990, and is now the nation's fastest growing minority group. Several studies have documented this population's comparative underuse of mental health services. A review of recent studies on the mental health of Asian and Pacific Island elders identifies a number of risk factors and protectors. Elder APIs appear to have poorer mental health compared to white counterparts, but not the poorest mental health within their own ethnic group. Within-group differences emerge, with recent immigrant groups and colonized populations appearing as most at-risk for mental health problems. A critical variable on this population's mental health status appears to be socioeconomic status,and yet an analysis of other demographic variables, notably nativity and gender, remain contradictory. A research agenda is proposed and implications for mental health administrators are suggested. 相似文献
79.
Behavioral and body size correlates of energy intake underreporting by obese and normal-weight women
Kretsch MJ Fong AK Green MW 《Journal of the American Dietetic Association》1999,99(3):300-6; quiz 307-8
Objective To examine behavioral and body size influences on the underreporting of energy intake by obese and normal-weight women.Design Seven-day estimated food records were kept by subjects before they participated in a 49-day residential study. Self-reported energy intake was compared with energy intake required to maintain a stable body weight during the residential study (reference standard). Energy intake bias and its relationship to various body size and behavioral measures were examined.Subjects Twenty-two, healthy, normal-weight (mean body mass index [BMI]=21.3) and obese (mean BMI=34.2) women aged 22 to 42 years were studied.Statistical analyses Analysis of variance, paired t test, simple linear regression, and Pearson correlation analyses were conducted.Results Mean energy intake from self-reported food records was underreported by normal-weight (−9.7%) and obese (−19.4%) women. BMI correlated inversely with the energy intake difference for normal-weight women (r=−.67, P=.02), whereas the Beck Depression Inventory correlated positively with the energy intake difference for obese women (r=.73, P<.01).Conclusion/applications Results suggest that body size and behavioral traits play a role in the ability of women to accurately self-report energy intake. BMI appears to be predictive of underreporting of energy intake by normal-weight women, whereas emotional factors related to depression appear to be more determinant of underreporting for obese women. Understanding causative factors of the underreporting phenomenon will help practicing dietitians to devise appropriate and realistic diet intervention plans that clients can follow to achieve meaningful change. J Am Diet Assoc. 1999;99:300-306. 相似文献
80.