全文获取类型
收费全文 | 21828篇 |
免费 | 1242篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 268篇 |
儿科学 | 496篇 |
妇产科学 | 263篇 |
基础医学 | 2826篇 |
口腔科学 | 686篇 |
临床医学 | 1956篇 |
内科学 | 4291篇 |
皮肤病学 | 416篇 |
神经病学 | 2551篇 |
特种医学 | 1642篇 |
外国民族医学 | 1篇 |
外科学 | 3094篇 |
综合类 | 207篇 |
一般理论 | 5篇 |
预防医学 | 1738篇 |
眼科学 | 427篇 |
药学 | 1109篇 |
中国医学 | 17篇 |
肿瘤学 | 1122篇 |
出版年
2022年 | 167篇 |
2021年 | 360篇 |
2020年 | 210篇 |
2019年 | 269篇 |
2018年 | 363篇 |
2017年 | 309篇 |
2016年 | 357篇 |
2015年 | 420篇 |
2014年 | 575篇 |
2013年 | 745篇 |
2012年 | 1099篇 |
2011年 | 1138篇 |
2010年 | 717篇 |
2009年 | 608篇 |
2008年 | 1085篇 |
2007年 | 1167篇 |
2006年 | 1075篇 |
2005年 | 1030篇 |
2004年 | 956篇 |
2003年 | 869篇 |
2002年 | 873篇 |
2001年 | 711篇 |
2000年 | 649篇 |
1999年 | 548篇 |
1998年 | 254篇 |
1997年 | 193篇 |
1996年 | 148篇 |
1995年 | 179篇 |
1994年 | 154篇 |
1993年 | 129篇 |
1992年 | 365篇 |
1991年 | 400篇 |
1990年 | 333篇 |
1989年 | 315篇 |
1988年 | 293篇 |
1987年 | 254篇 |
1986年 | 277篇 |
1985年 | 284篇 |
1984年 | 221篇 |
1983年 | 201篇 |
1982年 | 138篇 |
1981年 | 125篇 |
1979年 | 256篇 |
1978年 | 165篇 |
1977年 | 154篇 |
1975年 | 151篇 |
1974年 | 132篇 |
1973年 | 137篇 |
1972年 | 144篇 |
1970年 | 120篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Robin E. Clark Ph.D. Philip W. Bush M.B.A. Deborah R. Becker M.Ed. Robert E. Drake M.D. Ph.D. 《Administration and policy in mental health》1996,24(1):63-77
Recent research suggests that, for some people with severe mental illness, supported employment could improve vocational outcomes for little additional expense. This study describes the costs and client outcomes in one mental health center that converted two rehabilitative day treatment programs to supported employment. Converting from day treatment to supported employment improved vocational outcomes significantly without increasing costs. Although total costs for community treatment were lower in both sites after implementing supported employment, differences appeared to be due to decreasing unit costs over the study period. Results illustrate the importance of testing the effects of cost estimation methods on findings.This study was supported by West Central Services, the New Hampshire Division of Mental Health and Developmental Services, and NIMH grant K02-MH-00839. The authors are grateful to Jesse Turner and Phil Wyzik for facilitating the research. 相似文献
22.
23.
The statistical significance of ophthalmological and pediatric findings in the development of retinopathy of prematurity (ROP) was evaluated in a retrospective study of 338 premature infants. Short gestation time, frequent hypoxia, and low birthweight were strongly correlated with advanced stages of ROP. The influence of Vitamin E treatment, duration of oxygen therapy, and need for transfusions was less significant. Neither multiple births nor the infant's sex had any influence on the development of ROP. Cryotherapy appears to reduce ROP, but the number of cases in the present study was too small to permit statistical analysis. 相似文献
24.
25.
The effect of in vitro infection with herpes simplex virus 1 (HSV-1) on the Interleukin-1 (IL-1) activity of murine keratinocytes was investigated. IL-1 alpha mRNA synthesis was measured by the Northern blot technique, and the IL-1 protein production was measured in terms of the ability of dialysed supernatants from cultures of uninfected and HSV-1 infected keratinocytes to enhance mitogen-induced murine thymocyte proliferation. IL-1 alpha mRNA-synthesis in uninfected keratinocytes was detected 24 h and 48 h after isolation of the keratinocytes. IL-1 protein secretion by these keratinocytes was measureable at 18 h and reached a peak of 73 h, whereas intracellular and membrane-bound IL-1 protein production reached a maximum after 25 h. Keratinocytes, which had been cultured in vitro for 18 h, were infected with HSV-1 for 2 h and further cultured for an additional 4 h or 22 h before IL-1 measurements. A marked reduction of IL-1 alpha gene-expression was noted 6 hours after HSV-1-infection of keratinocytes, and nearly total shut-off was detected after infection for 24 h. Reduced gene-expression was paralleled by a reduction in the IL-1 protein secretion from the HSV-1 infected keratinocytes. 相似文献
26.
B B Becker 《Archives of otolaryngology--head & neck surgery》1991,117(7):789-791
Blepharoplasty and inferior punctal occlusion were performed on 24 consecutive patients with dry eye syndrome. Fifteen patients (62.5%) had symptomatic dry eye syndrome preoperatively and nine patients (37.5%) had asymptomatic dry eye syndrome diagnosed during the preoperative workup (subclinical dry eye syndrome). After surgery, nine patients (37.5%) had improvement of their dry eye syndrome, 10 patients (42%) were unchanged, and two patients (8%) had worsening of their dry eye syndrome. A third patient had worsening of the dry eye syndrome 6 months postoperatively when her puncta reopened. Two patients (8%) had increased irritation only when wearing contact lenses, but in one patient this resolved 6 months after surgery. Thus, although a significant number are improved, a few patients will have worsening of dry eye syndrome after blepharoplasty and inferior punctal occlusion. 相似文献
27.
28.
Ovalbumin (OVA) is a major allergen (Gal d II) of hen egg white and is often the cause of hypersensitivity reactions to food. Further knowledge of the antigenic and allergenic epitopes of allergens will provide better treatment of this disease. To analyse these epitopes we produced a panel of monoclonal antibodies (mAbs) against native OVA. The initial information about the epitopes was obtained with the binding patterns of these mAbs in IEF-immunoprints and western blots of OVA under reducing and non-reducing conditions. It was possible to demonstrate that the different conformations of OVA exhibit different epitopes, and that there are other epitopes which are shared by each conformation. Seven different, although sometimes overlapping epitopes, could be determined on native OVA; four different epitopes on denaturated non-reduced OVA by means of immunoblots of the intact molecule. The number of epitopes which could be differentiated by the mAbs was increased by the use of peptide blots after CNBr fragmentation of the molecule. IgE binding to different OVA conformations and to CNBr-fragments of OVA was also detectable and appears in the same regions as the reactivity of some mAbs. Western blots of OVA and CNBr-peptides demonstrate that some antigenic/allergenic binding sites seem at least partly to be continuous epitopes. The identification of the CNBr-fragments was performed by a microsequence analysis of blotted CNBr-fragments after a 2-dimensional electrophoresis. IgE was found to bind the two largest CNBr-fragments (residues 41-172 and 301-385), but not the fragment corresponding to residues 173-196. A number of monoclonal antibodies also reacted with the two large fragments, especially with fragment 301-385, and some bind also to shorter peptides, such as fragment 173-196, which were not reactive to patients' IgE. Most of the monoclonal antibodies and patients' IgE bind to the fragments 41-172 and 301-385 in 2D-PAGE blots suggesting that these fragments are involved in an immunogenic structure. 相似文献
29.
Two techniques are currently available for the creation of low anterior rectal stapled anastomoses. The first technique requires the placement of a pursestring suture at the superior margin of the rectal cuff, which is technically difficult. In the second technique, the rectal cuff is closed with a linear stapler. The circular end-to-end stapler, with the anvil removed, is then passed through an enterotomy in the rectal remnant. We describe an easy and safe method that obviates difficulties during the transanal passage of the stapler and minimizes the risk of injury to the rectum. This method uses an inexpensive and readily available rubber catheter and metal guide. 相似文献
30.
The postoperative patient may present with one or more of a variety of problems amenable to management by interventional radiologic techniques, which may be curative by themselves or may, in addition, require or allow successful surgical intervention. To optimize patient care, a good working relationship between the vascular surgeon and the interventional radiologist is essential. Consideration should be given to the patient's presenting signs and symptoms, the surgical history with its alteration of anatomy, the results of available noninvasive studies, and knowledge of various therapeutic alternatives. Vascular radiologic interventions include angioplasty, thrombolytic therapy, a combination of both angioplasty and thrombolysis, and newer techniques such as percutaneous valvectomy. In this report, examples of some of the experience at Indiana University are presented. Emphasis is placed on the appropriate approach to the patient. 相似文献