全文获取类型
收费全文 | 3052篇 |
免费 | 304篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 114篇 |
妇产科学 | 162篇 |
基础医学 | 375篇 |
口腔科学 | 110篇 |
临床医学 | 378篇 |
内科学 | 503篇 |
皮肤病学 | 31篇 |
神经病学 | 214篇 |
特种医学 | 223篇 |
外科学 | 414篇 |
综合类 | 82篇 |
一般理论 | 10篇 |
预防医学 | 243篇 |
眼科学 | 34篇 |
药学 | 147篇 |
中国医学 | 3篇 |
肿瘤学 | 291篇 |
出版年
2023年 | 16篇 |
2021年 | 22篇 |
2020年 | 30篇 |
2019年 | 40篇 |
2018年 | 31篇 |
2017年 | 42篇 |
2016年 | 57篇 |
2015年 | 47篇 |
2014年 | 48篇 |
2013年 | 82篇 |
2012年 | 161篇 |
2011年 | 193篇 |
2010年 | 92篇 |
2009年 | 107篇 |
2008年 | 153篇 |
2007年 | 172篇 |
2006年 | 171篇 |
2005年 | 123篇 |
2004年 | 128篇 |
2003年 | 133篇 |
2002年 | 137篇 |
2001年 | 99篇 |
2000年 | 127篇 |
1999年 | 74篇 |
1998年 | 69篇 |
1997年 | 90篇 |
1996年 | 66篇 |
1995年 | 55篇 |
1994年 | 53篇 |
1993年 | 47篇 |
1992年 | 72篇 |
1991年 | 57篇 |
1990年 | 49篇 |
1989年 | 55篇 |
1988年 | 48篇 |
1987年 | 48篇 |
1986年 | 41篇 |
1985年 | 41篇 |
1984年 | 24篇 |
1983年 | 22篇 |
1982年 | 23篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1978年 | 20篇 |
1977年 | 11篇 |
1974年 | 16篇 |
1973年 | 16篇 |
1972年 | 21篇 |
1970年 | 12篇 |
1966年 | 16篇 |
排序方式: 共有3366条查询结果,搜索用时 203 毫秒
1.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
2.
3.
A quasi-experimental study was conducted to evaluate the effect of preoperative interviews on patients' anxiety levels. A convenience sample of 60 was assigned between two groups of equal size: a treatment group in which subjects were interviewed by a perioperative nurse or a control group in which subjects were not interviewed. All subjects completed state-trait Anxiety Inventory questionnaires. Group comparison using analysis of covariance showed subjects who were interviewed by the perioperative nurse reported significantly less anxiety than control group subjects. 相似文献
4.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
5.
6.
7.
8.
9.
N. J. Cortes B. Afzali D. MacLean D. J. A. Goldsmith H. O'Sullivan J. Bingham D. A. Lewis E. MacMahon C. Y. W. Tong G. Koffman 《American journal of transplantation》2006,6(10):2497-2499
Two organ recipients developed serologic evidence of syphilis infection after renal transplantation from a common deceased donor with a history of treated syphilis. Testing of donor serum for syphilis, which occurred after transplantation, gave results interpreted as consistent with past infection. However, subsequent serologic results in the recipients suggested transmission of infection at transplantation due to active infection of the donor. This may be explained by recent donor re-infection in view of the current syphilis epidemic in the United Kingdom. An initial error in the treatment of recipients further served to highlight unfamiliarity in managing this resurgent infection in the context of organ transplantation. 相似文献
10.
Analysis of selenium content in commercial dietetic products 总被引:1,自引:0,他引:1
Selenium (Se) is largely associated with the protein component of foods. The processing of elemental feeds and artificial formulations used in clinical dietetic practice can, therefore, result in significant losses of Se from these products and the Se status of patients consuming these feeds may be compromised. A selection of commercial formulas typically used for enteral feeding, and for patients with cystic fibrosis, phenylketonuria and maple syrup urine disease were analysed for Se micro-fluorimetrically. Low Se contents were found in all food supplements except for Peptisorbon (0.09 mg Se/2000 kcal) and Clinifeed Protein Rich (0.08 mg Se/2000 kcal) which contained adequate daily Se levels according to the American RDI. The results show that a number of feeds are low in Se, especially those used for patients with cystic fibrosis and maple syrup urine disease. An investigation of the Se status of patients on these formulations may indicate the need for Se supplementation. 相似文献