全文获取类型
收费全文 | 10444篇 |
免费 | 660篇 |
国内免费 | 239篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 177篇 |
妇产科学 | 126篇 |
基础医学 | 719篇 |
口腔科学 | 592篇 |
临床医学 | 1402篇 |
内科学 | 1077篇 |
皮肤病学 | 126篇 |
神经病学 | 322篇 |
特种医学 | 300篇 |
外科学 | 1419篇 |
综合类 | 1200篇 |
预防医学 | 1222篇 |
眼科学 | 45篇 |
药学 | 1598篇 |
8篇 | |
中国医学 | 717篇 |
肿瘤学 | 231篇 |
出版年
2024年 | 17篇 |
2023年 | 145篇 |
2022年 | 217篇 |
2021年 | 383篇 |
2020年 | 339篇 |
2019年 | 330篇 |
2018年 | 281篇 |
2017年 | 325篇 |
2016年 | 376篇 |
2015年 | 355篇 |
2014年 | 642篇 |
2013年 | 864篇 |
2012年 | 566篇 |
2011年 | 665篇 |
2010年 | 553篇 |
2009年 | 521篇 |
2008年 | 543篇 |
2007年 | 491篇 |
2006年 | 402篇 |
2005年 | 398篇 |
2004年 | 286篇 |
2003年 | 318篇 |
2002年 | 264篇 |
2001年 | 169篇 |
2000年 | 186篇 |
1999年 | 146篇 |
1998年 | 126篇 |
1997年 | 142篇 |
1996年 | 116篇 |
1995年 | 121篇 |
1994年 | 118篇 |
1993年 | 81篇 |
1992年 | 93篇 |
1991年 | 80篇 |
1990年 | 55篇 |
1989年 | 55篇 |
1988年 | 51篇 |
1987年 | 67篇 |
1986年 | 56篇 |
1985年 | 59篇 |
1984年 | 52篇 |
1983年 | 48篇 |
1982年 | 41篇 |
1981年 | 37篇 |
1980年 | 34篇 |
1979年 | 23篇 |
1978年 | 16篇 |
1977年 | 19篇 |
1976年 | 18篇 |
1975年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
3种常用低温灭菌方法研究现状 总被引:5,自引:2,他引:3
阐述了环氧乙烷低温灭菌法、低温蒸汽甲醛灭菌法、过氧化氢等离子体灭菌法的灭菌机制、主要特点及应用范围。 相似文献
52.
利用热解-色质联用分析系统,对文题进行了研究,发现其热解过程是一个复杂的多元反应过程。在500~800℃,钛酸丁酯(Ⅰ)热解尾气产物主要是烯烃、醇、醚和醛类化合物。经热解机理分析,发现Ⅰ的重排断裂反应是整个热解过程的主反应,其反应动力学常数为3.87×10~5,活化能为69.3 kJ/ 相似文献
53.
A. Gustavo Gonzlez M. Angeles Herrador Agustín G. Asuero 《International journal of pharmaceutics》1995,120(2):215-220
The capacity factors (k′) of seven β-adrenoceptor blocking agents in six different reversed-phase HPLC systems have been determined. Octanol-aqueous buffer (pH 7.4) partition constants (P) for these blocking agents were also obtained. By using target factor analysis (TFA), good empirical correlations between the log k′ and log P were derived. The resulting hydrophobicity order agrees well with the metabolic elimination pathways of these drugs. 相似文献
54.
S. T. Fan Q. S. Wang C. M. Lo K. W. Tam Yu E. C. S. Lai J. Wong 《ANZ journal of surgery》1994,64(11):759-762
Impaired hepatic function is a major contributory factor to the high incidence of postoperative morbidity and mortality in patients with malignant biliary obstruction. Dynamic hepatic function tests such as indocyanine green (ICG) retention and aminopyrine breath tests were evaluated in such patients to define whether they were clinically useful for prediction of postoperative morbidity and mortality. Forty-four patients with malignant biliary obstruction undergoing surgery for relief of obstructive jaundice were recruited into the study. Indocyanine green retention and aminopyrine breath tests were carried out in all patients pre-operatively and repeated in 36 patients postoperatively. The ICG retention was abnormal in all patients before surgery and there was significant improvement 2 weeks after surgery (32.8 ± 2.5%vs 18.3 ± 2.8%, P= 0.001). The change in ICG retention levels correlated with the serum bilirubin levels but the pre-operative ICG retention value could not predict postoperative morbidity and mortality. The aminopyrine breath test was abnormal in all but one patient. It correlated with pre-operative prothrombin time of the patients before surgery but it did not improve significantly after surgery and was not predictive of postoperative outcome. It is concluded that both ICG retention and aminopyrine breath tests have limited clinical value in the pre-operative evaluation of patients with malignant biliary obstruction. 相似文献
55.
Masahiko Kawaguchi Masakazu Kuro Hisatoshi Ohsumi Toshito Nakajima Yoshihiro Kuriyama Jun Karasawa 《Journal of anesthesia》1994,8(1):60-63
We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF
was made using 50%–70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging.
All patients were anesthetized with 5.95±1.76 μg·kg−1 fentanyl and 0.22±0.07 mg·kg−1 diazepam under mechanical ventilation during CBF measurement. The values and distribution of LCBF on non-affected hemisphere
appeared to be unaltered by fentanyldiazepam anesthesia. We also assessed the cerebral carbon dioxide reactivity in 6 patients.
The cerebral carbon dioxide reactivity, expressed as percentage change in LCBF per unit change in arterial carbon dioxide
partial pressure, was 5.39±1.07, and there were no significant differences of reactivity among regions studied. In conclusion,
we showed reference values of LCBF and carbon dioxide reactivity, measured by stable xenon-enhanced computed tomography, in
patients under fentanyl-diazepam anesthesia. Carbon dioxide reactivity was preserved in all regions including gray matter,
white matter, and basal ganglia. 相似文献
56.
57.
F. Pott F. S. Larsen E. Ejlersen P. Linkis L. G. Jrgensen N. H. Secher 《Clinical physiology and functional imaging》1995,15(2):119-130
Summary. During transplantation of the liver cerebral perfusion was monitored by transcranial Doppler determined middle cerebral artery mean flow velocity (Vmean) and pulsatility index (PI) in six fulminant hepatic failure patients and 11 patients with chronic liver disease. In both groups of patients Vmean, PI and central haemodynamic variables were recorded during (1) the last preanhepatic hour; (2) the anhepatic phase; (3) the first 15 min of reperfusion; and (4) for the following 45 min of reperfusion. No significant differences were detected between the two groups of patients with respect to changes of variables with time. The Vmean (40±13 cm s-1 [mean±SD]), thoracic electrical impedance (TI) (30±7 Ohm), heart rate (97±19 beats min-1), mean arterial pressure (84±9 mmHg) and arterial carbon dioxide tension (PaCO2, 4.5±0.4 kPa) remained stable in the anhepatic phase, while cardiac output (CO, 7.6±2.7 to 5.4±1.41 min-1), stroke volume (SV, 79±26 to 56±15 ml) and PI (1.2±0.3 to 0.9±0.2) decreased (P<0.05). During reperfusion, CO (9.9±4.01 min-1), SV (105±40 ml), PaCO2 (5.5±0.6 kPa), Vmean (57±17 cm s-1) and PI (1.2±0.2) became elevated. Taken together, during the anhepatic phase of the liver transplantation a maintained central blood volume as indicated by the constant TI served for a stable blood pressure and in turn cerebral perfusion, whereas revascularization of the graft increased cerebral perfusion concomitant with an elevated carbon dioxide tension. 相似文献
58.
本研究分别观察了NO2染毒和LPG燃烧产物自然暴露对Wistar雄性成年大鼠肺脂质过氧化、肺胶原含量和尿HOP排泄的影响及其相互关系。结果发现7.52mg/m^3的NO2对三者均有一定影响,染毒剂量不同大鼠尿HOP排泄也有相应的变化。尿HOP的变化早于肺胶原含量,且两者有一定的相关关系。LPG燃烧产物暴露期间,尿HOP含量一直高于对照组,但未见肺胶原含量的变化,8周时尿HOP与肺脂质过氧化物之间有 相似文献
59.
Obstructed voiding is a well recognized complication following a suburethral sling procedure. Current methods of transvaginal
and transabdominal urethrolysis have had variable success rates in relieving the obstruction, and do not restabilize the urethra
to prevent potential postoperative stress incontinence. We report on a procedure used in 4 cases which addresses both of these
issues. All patients had persistent urinary retention beyond 8 weeks after a suburethral sling procedure. An oupatient procedure
consisting of sling incision and associated tissue interposition (vaginal wall in three cases and fascia lata in one) was
successful in relieving the obstruction. Continence status was maintained in 3 of the 4 patients. There were no major complications
of this outpatient procedure. 相似文献
60.
二氧化碳对白纹伊蚊的引诱作用 总被引:5,自引:4,他引:1
目的 测试二氧化碳(CO2)浓度与诱效率之间的关系,探明CO2对白纹伊蚊种群的引诱作用,以提高诱蚊灯的诱蚊效果。方法 不同浓CO2运用化学反应获取,通过诱蚊试验测定诱杀率反应诱杀效果。结果:探索出一个对白纹伊蚊具有较好引诱效应的CO2浓度10.34pp,与SB980型紫外光诱蚊灯结合试验表明,用CO2后对白纹伊蚊的诱杀率比对照灯提高13%—30%,平均20%。结论 浓度很低的CO2即对蚊虫有引诱效应,并能增强诱蚊灯的诱杀效果,满足无公害无污染的要求;实验为现有除虫产品的改良提供了一条新途径。 相似文献