全文获取类型
收费全文 | 1745766篇 |
免费 | 123082篇 |
国内免费 | 4673篇 |
专业分类
耳鼻咽喉 | 22376篇 |
儿科学 | 57045篇 |
妇产科学 | 46440篇 |
基础医学 | 268334篇 |
口腔科学 | 46125篇 |
临床医学 | 167132篇 |
内科学 | 330466篇 |
皮肤病学 | 35857篇 |
神经病学 | 138213篇 |
特种医学 | 63938篇 |
外国民族医学 | 418篇 |
外科学 | 246322篇 |
综合类 | 35301篇 |
现状与发展 | 3篇 |
一般理论 | 551篇 |
预防医学 | 144608篇 |
眼科学 | 38825篇 |
药学 | 130366篇 |
7篇 | |
中国医学 | 4032篇 |
肿瘤学 | 97162篇 |
出版年
2021年 | 13908篇 |
2019年 | 14524篇 |
2018年 | 20492篇 |
2017年 | 15317篇 |
2016年 | 16913篇 |
2015年 | 19230篇 |
2014年 | 26287篇 |
2013年 | 40282篇 |
2012年 | 56231篇 |
2011年 | 60274篇 |
2010年 | 34954篇 |
2009年 | 31823篇 |
2008年 | 54980篇 |
2007年 | 58753篇 |
2006年 | 58422篇 |
2005年 | 56217篇 |
2004年 | 53995篇 |
2003年 | 51469篇 |
2002年 | 49854篇 |
2001年 | 77200篇 |
2000年 | 79219篇 |
1999年 | 66247篇 |
1998年 | 18681篇 |
1997年 | 16629篇 |
1996年 | 16473篇 |
1995年 | 15655篇 |
1994年 | 14484篇 |
1992年 | 52447篇 |
1991年 | 52660篇 |
1990年 | 51494篇 |
1989年 | 49277篇 |
1988年 | 45483篇 |
1987年 | 44641篇 |
1986年 | 42316篇 |
1985年 | 40429篇 |
1984年 | 30346篇 |
1983年 | 25842篇 |
1982年 | 15018篇 |
1979年 | 27909篇 |
1978年 | 19872篇 |
1977年 | 16168篇 |
1976年 | 16242篇 |
1975年 | 17466篇 |
1974年 | 20896篇 |
1973年 | 20242篇 |
1972年 | 18743篇 |
1971年 | 17677篇 |
1970年 | 16379篇 |
1969年 | 14966篇 |
1968年 | 14271篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Clinical experience of phototherapy for non-haemolytic hyperbilirubinaemia in 3999 infants in Kandang Kerbau Hospital, Singapore, is documented. Phototherapy was most effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1500 g) and least effective in full term infants with very low birth weight (gestation greater than or equal to 37 weeks, birth weight less than or equal to 1500 g) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2270 g). Overall, phototherapy was effective in almost all the infants, with a failure rate of only 2.00/1000 infants. No characteristic features common to all the failures could be detected. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1000), with the response to the second exposure comparable to that to the first. No infant required a third exposure. All the infants tolerated phototherapy well, none developing any illness that could be attributed to the treatment. This clinical experience shows that phototherapy for the treatment of nonhaemolytic hyperbilirubinaemia is effective and safe. 相似文献
962.
In this study, the lamination pattern of the main olfactory bulb (MOB) of P. hispanica has been described using EM and Golgi-impregnation techniques. Six layers could be distinguished from the external surface to the ventricles: olfactory nerve layer (ONL), glomerular layer (GL), external plexiform layer (EPL), mitral layer (ML), internal plexiform layer (IPL), and granular cell layer (GCL). In ONL unmyelinated axonic bundles from the olfactory mucosa are seen. The GL is defined by the presence of terminal ramifications of the mitral primary dendrites and by axonic terminals of the olfactory nerve. The EPL is a dendritic articulation layer between the mitral and granule cells, where a great density of dendrodendritic synaptic contacts has been found. The ML is defined by the large mitral cell somata, and the IPL by myelinated axonic bundles that run rostro-caudally. Finally, the GCL is characterized by the presence of granule cells. Using the Golgi-impregnation method, five different neuronal types have been described. In the glomerular layer, a small cell population is located; these neurons seem the periglomerular cells described in mammals. The second type corresponds to the mitral cell population and the morphological features of these cells resemble to those of mammals. The three remaining types constitute the granule cell population; this population is characterized by a great morphological heterogeneousness. However, these types have been differentiated according to their dendritic tree morphology and location of the cell body. A morphological gradient depending on the distance of cell body for each type to the ependymal layer, has been observed. In EM, four different types of neuronal cell bodies according to their location and ultrastructure have been defined. The laminar organization of the MOB of Podarcis is similar to that in all vertebrates. The results for the fine structure and dendritic tree morphology have revealed a high similarity between these reptiles and mammals. 相似文献
963.
Electrophysiologic effects of halothane and quinidine on canine Purkinje fibers: evidence for a synergistic interaction 总被引:3,自引:0,他引:3
The authors studied possible interactions between halothane and quinidine on the action potentials of canine Purkinje fibers superfused with Tyrode's solution. Using standard microelectrode techniques and a physiologic pacing rate (2 Hz), halothane in concentrations from 0.5% to 2% decreased the action potential duration to 50% repolarization (ADP50). Total ADP (APD100), in contrast, increased after 1% and 2% halothane. Resting membrane potential (RMP) and action potential amplitude (APamp) increased after 0.5% halothane, but returned to control with higher halothane levels. Conduction time (CT) increased at each halothane level. Pacing at faster (3 Hz) or slower (1 Hz) rates did not markedly alter the effects of halothane. Quinidine 1 X 10(-5)M decreased the phase O upstroke (Vmax) and prolonged APD100 and CT. When halothane was added, RMP and APamp decreased, Vmax decreased further, and APD100 and CT were markedly prolonged. This resulted in conduction block or inexcitability, especially at faster pacing rates (3 Hz). Synergistic interactions between halothane and quinidine were found on RMP, APamp, APD100, and CT. Effects on Vmax, APD50, and action potential duration to 90% repolarization (APD90) were additive. It is concluded that quinidine and halothane act synergistically to decrease action potential amplitude, lower RMP, and prolong conduction. Severe depression of conduction often progressed to conduction block or inexcitability when halothane, 2%, was administered during superfusion with therapeutic concentrations of quinidine. 相似文献
964.
965.
V K Ryzhkov N A Borisova E M Gapchenko I A Dmitrieva 《Vestnik khirurgii imeni I. I. Grekova》1986,136(1):11-14
Roentgen endovascular occlusion with spiral emboli was used in 240 patients with different diseases. The introduction of spiral emboli into the arteries of abdominal and retroperitoneal organs was fulfilled through usual angiographic catheters. Duration of the arterial occlusion was checked up in the following angiographic examinations and showed the devices described to be appropriate for a continuous arterial blockade. No complications resulting from the introduction of the spiral embolus were noted. 相似文献
966.
967.
968.
Pyomyositis occurs infrequently in temperate climates. The fulminating peracute form caused by group A Streptococcus is exceedingly rare. We present two children with streptococcal pyomyositis. One child was admitted in septic shock and required intensive supportive care during the acute stage of his illness. Persistent swelling and tenderness of his left thigh presented a diagnostic problem, which was eventually resolved with the aid of computerized tomography. Despite appropriate antibiotic therapy from the onset of illness, surgical debridement of the affected muscle was necessary. The second child presented with pyomyositis of the left paravertebral muscles and signs of incipient shock but did well on antibiotic therapy alone. 相似文献
969.
970.
The development of the eye was investigated in the mouse embryo following a single administration of ethanol plus [3H]thymidine to the dam on day 13 of gestation. After 1 hr there was no difference in the number of labelled cells/100 micron 2 in the neural layer of the retina compared to controls, but there was an alcohol-related reduction in labelling density. After 24 hr there was an increase in the numbers of both pyknotic cells and mitotic figures, breaks occurred in the inner surface of the retina and cell debris was being extruded into the posterior chamber. At 48 hr the increase in pyknotic cells persisted, but there was less evidence of cell debris and the borders had been repaired. The estimated cell cycle time in the neural progenitor cells following maternal alcohol administration was increased 7-fold compared to controls. Morphometric analysis revealed that after 48 hr there were significant alcohol-related reductions in the width and depth of the eye, in the thickness of the neural layer and in the interocular distance. It appears that many of the ophthalmic abnormalities reported in human fetal alcohol syndrome can be produced in the mouse embryo following a single episode of acute maternal intoxication during a critical period of ocular ontogeny, and that they evolve primarily from disturbances in the normal patterns of recruitment and loss of neural progenitor cells in the developing retina. 相似文献