全文获取类型
收费全文 | 9292篇 |
免费 | 237篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 385篇 |
妇产科学 | 2302篇 |
基础医学 | 952篇 |
口腔科学 | 421篇 |
临床医学 | 1032篇 |
内科学 | 1060篇 |
皮肤病学 | 154篇 |
神经病学 | 439篇 |
特种医学 | 423篇 |
外科学 | 895篇 |
综合类 | 94篇 |
一般理论 | 1篇 |
预防医学 | 676篇 |
眼科学 | 196篇 |
药学 | 239篇 |
中国医学 | 47篇 |
肿瘤学 | 131篇 |
出版年
2018年 | 57篇 |
2017年 | 83篇 |
2016年 | 48篇 |
2015年 | 66篇 |
2014年 | 88篇 |
2013年 | 274篇 |
2012年 | 104篇 |
2011年 | 185篇 |
2010年 | 145篇 |
2009年 | 288篇 |
2008年 | 202篇 |
2007年 | 165篇 |
2006年 | 194篇 |
2005年 | 186篇 |
2004年 | 167篇 |
2003年 | 139篇 |
2002年 | 127篇 |
2001年 | 164篇 |
2000年 | 159篇 |
1999年 | 343篇 |
1998年 | 289篇 |
1997年 | 341篇 |
1996年 | 371篇 |
1995年 | 321篇 |
1994年 | 277篇 |
1993年 | 205篇 |
1992年 | 246篇 |
1991年 | 261篇 |
1990年 | 207篇 |
1989年 | 183篇 |
1988年 | 179篇 |
1987年 | 146篇 |
1986年 | 178篇 |
1985年 | 139篇 |
1984年 | 120篇 |
1983年 | 154篇 |
1982年 | 97篇 |
1981年 | 92篇 |
1980年 | 108篇 |
1979年 | 105篇 |
1978年 | 73篇 |
1977年 | 103篇 |
1976年 | 106篇 |
1975年 | 103篇 |
1974年 | 74篇 |
1973年 | 73篇 |
1972年 | 57篇 |
1971年 | 52篇 |
1970年 | 54篇 |
1922年 | 60篇 |
排序方式: 共有9534条查询结果,搜索用时 15 毫秒
1.
2.
3.
C F A Peralta P Cavoretto B Csapo O Falcon K H Nicolaides 《Ultrasound in obstetrics & gynecology》2006,27(2):128-133
OBJECTIVE: To establish reference intervals for the fetal right, left and total lung volumes and heart volume between 12 and 32 weeks of gestation. METHODS: Fetal lung and heart volumes were measured using three-dimensional (3D) ultrasound in 650 normal singleton pregnancies at 12-32 weeks. The VOCAL (Virtual Organ Computer-aided AnaLysis) technique was used to obtain a sequence of six sections of each lung and the heart around a fixed axis, each after a 30 degrees rotation from the previous one. The rotation axis for the lungs extended from the apex to the upper limit of the diaphragm dome, and the rotation axis for the heart extended from its apex to its connection to the great vessels. The contour of each of these organs was drawn manually in the six different rotation planes to obtain the 3D volume measurement. In 60 cases the fetal lungs and heart volumes were measured by the same sonographer twice and also by a second sonographer once in order to compare the measurements and calculate intra- and interobserver agreement. RESULTS: The total lung volume and heart volume increased with gestation, from respective mean values of 1.6 and 0.6 mL at 12 weeks to 10.9 and 4.3 mL at 20 weeks and 49.3 and 26.6 mL at 32 weeks. The right to left lung volume ratio did not change significantly with gestation (median, 0.7), whereas the heart to total lung volume ratio increased with gestation from about 0.3 at 12 weeks to 0.5 at 32 weeks. In the Bland-Altman plot, the difference between paired measurements by two sonographers was, in 95% of the cases, less than 0.05, 0.5 and 1.9 mL for each lung at 12-13, 19-22 and 29-32 weeks, respectively, and the corresponding values for the heart volumes were 0.04, 0.4 and 2.3 mL. CONCLUSIONS: In normal fetuses the lung and heart volumes increase between 12 and 32 weeks of gestation. The extent to which in pathological pregnancies possible deviations in these measurements from normal prove to be useful in the prediction of outcome remains to be determined. 相似文献
4.
5.
6.
Socioeconomic determinants of health related quality of life in childhood and adolescence: results from a European study . von Rueden , U. , Gosch , A. , Rajmil , L. , Bisegger , C. , Ravens-Sieberer , U. , the European KIDSCREEN group ( 2006 ) Journal of Epidemiology and Community Health , 60 , 130 – 135 . 相似文献
7.
8.
Anorectal function in the solitary rectal ulcer syndrome 总被引:8,自引:6,他引:2
Nigel R. Womack F.R.C.S. Professor Norman S. Williams M.S. John H. Holmfield Mist John F. Morrison Ph.d. 《Diseases of the colon and rectum》1987,30(5):319-323
The anorectal function of nine patients with solitary rectal ulcer syndrome (SRUS) (5 F: 4 M, median age, 27 (range, 19–41
years) and nine control subjects (5 F: 4 M, median age, 47 (35–66)P<0.01) has been investigated by a new technique that radiologically visualizes the anorectum during voiding of a semisolid
contrast medium, while simultaneously measuring intrarectal pressure and anal sphincter EMG activity. A degree of rectal prolapse
was demonstrated in eight of the SRUS patients; six of these lesions were clinically occult. Abnormal failure of the anal
sphincter to relax on voiding was present in seven of the SRUS patients. These abnormalities resulted in the SRUS patients
requiring a greater increase in intrarectal pressure (median, 100 cm water) to void than the control subjects (median, 65
cm water,P<0.01). This combination of high intrarectal pressure and rectal prolapse during straining seems to be the cause of SRUS
This work was supported by a grant from the Medical Research Council. 相似文献
9.
Gordon J. Harris Ph.D. Instructor Jonathan M. Links Ph.D. Associate Professor Godfrey D. Pearlson M.B. B.S. Director Edwaldo E. Camargo M.D. Associate Professor 《Psychiatry research》1991,40(3):167-180
We developed a semiautomatic method termed “cortical circumferential profiling” for objective analysis of cerebral cortex function in emission tomographic neuroimaging studies. This method treats cortex as a continuous ring near the outer brain edge. A computer algorithm samples the cortex at 60 contiguous, equiangular locations, using 1-cm2 samples. These values are plotted as a function of cortical angle to produce the cortical circumferential profile. This method was used in a study of regional cerebral perfusion in 15 patients with Alzheimer's disease and 8 elderly control subjects using N-isopropyl [I-123]-iodoamphetamine. Cortical circumferential profiling decreases variability, examines the entire cortex within slices at preselected levels above the orbital-meatal line, and facilitates intrasubject and intersubject comparisons. 相似文献
10.
Fulminant hepatic failure associated with aplastic anaemia after treatment with danazol. Case report
T. NAKAJIMA Consultant N. MIZUSHIMA Registrar H. MATSUDA Registrar M. MATSUMOTO Registrar K. TAMAKOSHI Senior Registrar H. ISHII Consultant S. MORIOKA Consultant K. KANAI Associate Professor Y. IKEDA Senior Lecturer T. TERAO Associate Professor 《BJOG : an international journal of obstetrics and gynaecology》1986,93(9):1013-1015