全文获取类型
收费全文 | 115971篇 |
免费 | 5907篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 1771篇 |
儿科学 | 5196篇 |
妇产科学 | 3928篇 |
基础医学 | 16052篇 |
口腔科学 | 2831篇 |
临床医学 | 8306篇 |
内科学 | 21963篇 |
皮肤病学 | 3355篇 |
神经病学 | 8973篇 |
特种医学 | 5043篇 |
外国民族医学 | 32篇 |
外科学 | 19013篇 |
综合类 | 1595篇 |
一般理论 | 29篇 |
预防医学 | 5803篇 |
眼科学 | 3390篇 |
药学 | 8041篇 |
中国医学 | 325篇 |
肿瘤学 | 6370篇 |
出版年
2018年 | 887篇 |
2017年 | 773篇 |
2016年 | 1089篇 |
2015年 | 1215篇 |
2014年 | 1598篇 |
2013年 | 2359篇 |
2012年 | 3089篇 |
2011年 | 3138篇 |
2010年 | 1966篇 |
2009年 | 1926篇 |
2008年 | 3245篇 |
2007年 | 3481篇 |
2006年 | 3623篇 |
2005年 | 3739篇 |
2004年 | 3684篇 |
2003年 | 3552篇 |
2002年 | 3504篇 |
2001年 | 7013篇 |
2000年 | 6957篇 |
1999年 | 5857篇 |
1998年 | 1622篇 |
1997年 | 1558篇 |
1996年 | 1334篇 |
1995年 | 1201篇 |
1994年 | 1091篇 |
1993年 | 1119篇 |
1992年 | 3765篇 |
1991年 | 3575篇 |
1990年 | 3561篇 |
1989年 | 3348篇 |
1988年 | 2985篇 |
1987年 | 2894篇 |
1986年 | 2803篇 |
1985年 | 2617篇 |
1984年 | 1943篇 |
1983年 | 1594篇 |
1982年 | 927篇 |
1981年 | 915篇 |
1980年 | 765篇 |
1979年 | 1822篇 |
1978年 | 1346篇 |
1977年 | 1111篇 |
1976年 | 936篇 |
1975年 | 1178篇 |
1974年 | 1212篇 |
1973年 | 1198篇 |
1972年 | 1040篇 |
1971年 | 975篇 |
1970年 | 880篇 |
1969年 | 787篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
21.
K C Ho U Roessmann L Hause G Monroe 《Journal of neuropathology and experimental neurology》1986,45(2):179-188
This study compares the weight of the human brain to gestational age and body dimensions. A new formula for calculating the rate of growth is proposed. It consists of a second order polynomial function: Y = A0 + A1X + A2X2, in which Y is brain weight, body weight, height, or body surface area; X is gestational age in weeks and A0, A1, and A2 are statistically estimated coefficients. In utero, the growth rate is most rapid for body weight, followed in decreasing order by brain weight, body surface area, and height. Brain growth is the same for both sexes in black and white races; it accelerates between the 20th and 45th weeks of gestation. The size of the newborn infant brain is directly related to gestational age and body size and is not determined by sex or race. 相似文献
22.
23.
In 50 children, 4 months to 12 years of age, with minor head trauma non-target visual event-related potentials were performed and compared to a second registration of the potentials some months later. On following-up there was a clear tendency for a relative improvement of the latencies of the endogenous potentials. In this way non-target visual event-related potentials proved to be of value in the investigation of mental impairment in early childhood. 相似文献
24.
25.
N U Khodzhaeva I V Ovchinnikov A G Bogdanov-Berezovski? Sh A Khuda?bergenov 《Laboratornoe delo》1991,(3):60-61
The duodenal contents were examined in 81 patients with gastroduodenal ulcer. Bile acid concentrations, alkaline phosphatase activity, and sodium ion concentration were measured for the detection of duodenogastric reflux. Measurements of sodium ion concentration permitted estimation of the immediate volume of the duodenogastric reflux in the gastric contents. No methods for duodenogastric reflux detection should be given preference in examinations of peptic ulcer patients. Multiple-modality studies appear to be the most effective. 相似文献
26.
The analysis of vestibular responses in a comatose patient often provides the critical information for making a correct preliminary diagnosis and directing the subsequent laboratory evaluation. Because of some uncertainties about what is being tested with the various bedside maneuvers that are used to elicit vestibular responses, we review the physiologic basis for the oculomotor responses that occur with head rotation or with caloric stimuli. We further urge precise and unambiguous terminology to describe both stimulus and response. We suggest using physiologically well-defined terms such as vestibulo-ocular reflex and cervico-ocular reflex and avoiding potentially misleading terms such as the doll's head and the oculocephalic maneuvers. 相似文献
27.
28.
K Junge U Klinge B Klosterhalfen P R Mertens R Rosch A Schachtrupp F Ulmer V Schumpelick 《Journal of investigative surgery》2002,15(6):319-328
Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material. 相似文献
29.
30.
S L Gardini U Sergiacomi G G Colarossi 《Quaderni Sclavo di diagnostica clinica e di laboratorio》1987,23(1):32-42
New parametric and non parametric statistical methods have been compared in the evaluation of experimental data of CEA and CA 19.9 using a brief program in BASIC. We have found that the distribution of the two markers is the same of that described in literature except for both the means that we have found being slightly higher than that ones described by other authors. 相似文献