全文获取类型
收费全文 | 1564446篇 |
免费 | 109732篇 |
国内免费 | 4822篇 |
专业分类
耳鼻咽喉 | 19620篇 |
儿科学 | 51974篇 |
妇产科学 | 42548篇 |
基础医学 | 228432篇 |
口腔科学 | 42196篇 |
临床医学 | 149405篇 |
内科学 | 300315篇 |
皮肤病学 | 31048篇 |
神经病学 | 127813篇 |
特种医学 | 59943篇 |
外国民族医学 | 462篇 |
外科学 | 218896篇 |
综合类 | 30677篇 |
现状与发展 | 1篇 |
一般理论 | 533篇 |
预防医学 | 133757篇 |
眼科学 | 34818篇 |
药学 | 114772篇 |
8篇 | |
中国医学 | 3354篇 |
肿瘤学 | 88428篇 |
出版年
2021年 | 12119篇 |
2019年 | 12872篇 |
2018年 | 21185篇 |
2017年 | 17254篇 |
2016年 | 17363篇 |
2015年 | 20950篇 |
2014年 | 26563篇 |
2013年 | 37864篇 |
2012年 | 57577篇 |
2011年 | 55568篇 |
2010年 | 31516篇 |
2009年 | 30596篇 |
2008年 | 48733篇 |
2007年 | 52037篇 |
2006年 | 52380篇 |
2005年 | 58762篇 |
2004年 | 59523篇 |
2003年 | 52266篇 |
2002年 | 45027篇 |
2001年 | 64821篇 |
2000年 | 64372篇 |
1999年 | 57443篇 |
1998年 | 15812篇 |
1997年 | 14161篇 |
1996年 | 13975篇 |
1995年 | 13332篇 |
1994年 | 12344篇 |
1992年 | 47206篇 |
1991年 | 46588篇 |
1990年 | 45325篇 |
1989年 | 42978篇 |
1988年 | 39867篇 |
1987年 | 38845篇 |
1986年 | 37006篇 |
1985年 | 35050篇 |
1984年 | 26165篇 |
1983年 | 22203篇 |
1982年 | 12924篇 |
1979年 | 24076篇 |
1978年 | 16998篇 |
1977年 | 13705篇 |
1976年 | 13296篇 |
1975年 | 14255篇 |
1974年 | 17503篇 |
1973年 | 16855篇 |
1972年 | 15770篇 |
1971年 | 14794篇 |
1970年 | 13746篇 |
1969年 | 12551篇 |
1968年 | 11897篇 |
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
991.
992.
993.
Nonhair-bearing skin should be used when grafting is necessary during urethroplasty for stricture or hypospadias repair. Occasionally, this is not possible or hair-bearing skin is used inadvertently. Traditionally, electrocoagulation has been the method used for epilation when intraluminal hair has become a problem, such as interfering with flow, as a focus for recurrent urinary tract infection or acting as a nidus for calculus formation. Electrocautery also is performed during grafting in an attempt to prevent the growth of hair when hair-bearing skin is used. Unfortunately, due to lack of penetration the hair follicles are not destroyed and the epilating procedure fails or is only partially successful. The neodymium:YAG surgical laser can photocoagulate tissue to a depth up to 5.0 mm, and thus, has the ability to destroy hair follicles. We report 4 cases presenting with clinical problems directly related to hair-bearing urethral grafts successfully treated by neodymium:YAG laser epilation. 相似文献
994.
Esophageal pH monitoring is the accepted standard for the investigation of gastroesophageal reflux (GER) in adults. A postal questionnaire was sent to 912 United Kingdom paediatric physicians & surgeons. Five hundred forty-seven (61%) replied, with 124 (22.7%) currently using the technique, mostly in conjunction with barium swallow and/or esophagoscopy. The use of pH monitoring to quantify GER was also accepted in principal as being the best determinant of reflux by a further 186 (34%), but as yet was unavailable in their hospitals. Pediatricians were also questioned as to their management of children with GER. The majority were treated medically with a variety of antireflux medication, with only 237 (42%) referring cases for surgery. 相似文献
995.
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
996.
Extracellular pH in the brain during ischemia: relationship to the severity of lactic acidosis 总被引:2,自引:0,他引:2
K Katsura A Ekholm B Asplund B K Siesj? 《Journal of cerebral blood flow and metabolism》1991,11(4):597-599
On the basis of data showing a bimodal distribution of values for extracellular pH (pHe), and a discontinuous delta PCO2/delta lactate relationship, Kraig et al. (1986) proposed that H+ is grossly compartmentalized between neurons and glia in the ischemic brain. We measured delta pHe during ischemia, varying ischemic lactate contents between 9 and 38 mmol kg-1. No bimodal distribution was found, but delta pHe varied linearly with lactate content. Because we have also failed to record a discontinuous delta PCO2/delta lactate relationship, we conclude that major compartmentation of H+ does not occur during ischemia. 相似文献
997.
The renin-angiotensin system has traditionally been associated with the regulation of fluid and electrolyte balance. In this review we summarize the data which ascribes a completely new function to this system, i.e., the regulation of alcohol consumption. In addition, we suggest a possible mechanism for this effect based on the concept of a satiety or stop process. The approach taken was to examine the effect on alcohol intake of a wide variety of drug, genetic, dietary, surgical and neurosurgical manipulations, each of which has a range of biological effects characteristic of that manipulation, but all of which share the common property of altering activity in the renin-angiotensin system. The effect of these manipulations on alcohol intake was most parsimoniously explained by reference to their ability to raise or lower activity in the renin-angiotensin system. Any intervention which modulates activity in this system, either directly or indirectly, is likely to have consequences for alcohol consumption. 相似文献
998.
A genetic analysis of mammalian neuronal physiology might now be possible due to the development of defective herpes simplex virus vectors, which allow gene transfer directly into mature neurons, in culture or in the adult brain. Genetically altered proteins that play critical roles in neuronal physiology, including those responsible for the generation of action potentials, synthesis and release of neurotransmitters, and signal transduction enzymes, can now be stably expressed in neurons. The effect of such altered proteins on neuronal physiology can therefore be examined, using the tools of modern neuroscience. Genetic manipulation is biochemically specific and stable, and can be targeted both to a particular cell type and to a particular subregion of the cell to yield insights into the molecular basis for specific brain functions. 相似文献
999.
1000.