全文获取类型
收费全文 | 2850篇 |
免费 | 283篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 93篇 |
妇产科学 | 14篇 |
基础医学 | 445篇 |
口腔科学 | 92篇 |
临床医学 | 247篇 |
内科学 | 384篇 |
皮肤病学 | 117篇 |
神经病学 | 510篇 |
特种医学 | 151篇 |
外科学 | 318篇 |
综合类 | 74篇 |
预防医学 | 182篇 |
眼科学 | 72篇 |
药学 | 172篇 |
中国医学 | 1篇 |
肿瘤学 | 308篇 |
出版年
2022年 | 20篇 |
2021年 | 49篇 |
2020年 | 37篇 |
2019年 | 50篇 |
2018年 | 46篇 |
2017年 | 33篇 |
2016年 | 47篇 |
2015年 | 53篇 |
2014年 | 53篇 |
2013年 | 79篇 |
2012年 | 115篇 |
2011年 | 97篇 |
2010年 | 88篇 |
2009年 | 86篇 |
2008年 | 105篇 |
2007年 | 126篇 |
2006年 | 114篇 |
2005年 | 117篇 |
2004年 | 96篇 |
2003年 | 90篇 |
2002年 | 97篇 |
2001年 | 89篇 |
2000年 | 85篇 |
1999年 | 97篇 |
1998年 | 80篇 |
1997年 | 62篇 |
1996年 | 55篇 |
1995年 | 53篇 |
1994年 | 33篇 |
1993年 | 52篇 |
1992年 | 90篇 |
1991年 | 79篇 |
1990年 | 66篇 |
1989年 | 77篇 |
1988年 | 68篇 |
1987年 | 60篇 |
1986年 | 42篇 |
1985年 | 53篇 |
1984年 | 39篇 |
1983年 | 36篇 |
1982年 | 21篇 |
1981年 | 23篇 |
1980年 | 32篇 |
1979年 | 24篇 |
1977年 | 20篇 |
1976年 | 20篇 |
1975年 | 22篇 |
1972年 | 25篇 |
1971年 | 20篇 |
1970年 | 18篇 |
排序方式: 共有3197条查询结果,搜索用时 9 毫秒
51.
Patterns of intrinsic connections and features of individual intrinsic axons in the caudal subdivision of the dorsolateral visual area (DL(C)) were investigated in four squirrel monkeys (Saimiri) following extracellular injections of the tracers biocytin, biotinylated dextran amine, and wheat germ agglutinin conjugated to horseradish peroxidase. Injections were defined in DL(C) by reference to architectonic borders and patterns of connections with other cortical areas. Intrinsic connections extended up to 6 mm from an injection and were usually anisotropic, extending farther dorsoventrally than anteroposteriorly. Injections that involved the supragranular layers produced up to 20 mainly supragranular patches of projections that had a width of 285 +/- 8 microm (mean +/- standard error) and area of 0.125 +/- 0.016 mm(2). Seventy-four intrinsic axon segments with a total of 3,290 boutons were drawn and their bouton spacing measured. The sample included axons in layers 1, 2-3, 5, and multiple (>2) layers; horizontally and vertically oriented axons; and axons in an injection halo, patch, or nonpatch region of projections. There were no differences in bouton spacing for axons in halo, patch, or nonpatch regions. Layer 1 axons (n = 7) had a significantly sparser distribution of boutons (median interbouton interval of 45.2 +/- 17.8 microm) than the layers 2-3 (n = 35) and layer 5 axons (n = 26), which did not differ in bouton spacing (median interbouton intervals of 8.1 +/- 0.4 microm and 8.4 +/- 0.8 microm, respectively). Patterns of intrinsic connections in DL(C) are related to neural organization and properties reported for DL or visual area V4, and are compared to intrinsic connections of other areas. 相似文献
52.
This study assessed misuse of anticholinergic drugs in a population of 50 patients with serious mental illness who were assertively managed by a community-based outreach team in Sydney, Australia. One-third of the subjects reported having misused anticholinergics over the previous month. All anticholinergics were misused, and trihexyphenidyl (benzhexol) was misused most frequently. Most subjects misused at least one other drug as well. On direct questioning, the reason given most frequently was "to get high"; on indirect questioning, reasons were related more to peer participation and feelings of futility. Marginalized patients living in the community are vulnerable to the misuse of anticholinergic drugs. 相似文献
53.
Michael Weller Nicholas Butowski David D Tran Lawrence D Recht Michael Lim Hal Hirte Lynn Ashby Laszlo Mechtler Samuel A Goldlust Fabio Iwamoto Jan Drappatz Donald M ORourke Mark Wong Mark G Hamilton Gaetano Finocchiaro James Perry Wolfgang Wick Jennifer Green John H Sampson 《The lancet oncology》2017,18(12):e709-e710
54.
Andrea Pace Linda Dirven Johan A F Koekkoek Heidrun Golla Jane Fleming Roberta Rudà Christine Marosi Emilie Le Rhun Robin Grant Kathy Oliver Ingela Oberg Helen J Bulbeck Alasdair G Rooney Roger Henriksson H Roeline W Pasman Stefan Oberndorfer Michael Weller Martin J B Taphoorn 《The lancet oncology》2017,18(6):e330-e340
55.
血、尿中安眠酮及其代谢物的测定 总被引:1,自引:0,他引:1
通过一例安眠酮中毒病人血、尿中安眠酮及其代谢物的测定,描述了用紫外光谱(uv)、气相色谱(GC)和气相色谱质谱(GC/MS)法测定安眠酮及其代谢物的系统分析方法。样品的提取净化采用液一液萃取和固相萃取两种方法,都得到了很好的结果。紫外光谱用于测定血、尿中安眠酮和其代谢物的总量;气相色谱用于测定血、尿中安眠酮原药的含量;气相色谱质谱则用于鉴定血、尿中的安眠酮及其代谢物。除安眠酮外,血、尿中共检出10种安眠酮代谢物,其中包括两种乙酰化代谢物。此法还为临床救治提供指导。 相似文献
56.
Michael Weller Peter Wiedemann Martin Bresgen Klaus Heimann 《International ophthalmology》1991,15(2):103-108
Several cell types participate in the formation of vitreoretinal traction membranes in proliferative intraocular disorders. The communication between these cells involves hormones, growth factors, and the interaction with extracellular matrix molecules. We have previously demonstrated a partial colocalisation of two potent mediators of cell attachment, fibronectin and vitronectin, in periretinal membranes from patients with proliferative vitreoretinopathy (PVR). We found a similar pattern of vitronectin and fibronectin deposition in proliferative diabetic retinopathy (PDR) (n = 6). Now we show the expression of the corresponding cell surface receptors, integrins, for fibronectin and vitronectin by proliferating cells in 22 periretinal membranes, including traumatic (n = 8) and idiopathic (n = 8) PVR as well as PDR membranes (n = 6). Integrins are membrane receptors for extracellular matrix macromolecules which are involved in such basic biological phenomena as embryogenesis and metastasis. Future studies on the pathogenesis of vitreoretinal proliferation will have to focus on the initiation, maintenance, and regulation of this intercellular communication network involving attachment proteins and integrins. 相似文献
57.
M.D.Carol L. Carraccio M.D. Sc.D.Marie C. McCormick Ph.D.Susan C. Weller 《The Journal of pediatrics》1987,110(6):982-987
An assessment of health cognition and health locus of control (HLOC) was obtained in 85 healthy and 81 chronically ill children, using instruments adapted from Piaget's work and standard HLOC measures. A relationship between HLOC and compliance was sought in a subset of children with spina bifida taught self-catheterization. Evidence of the developmental nature of health cognition and HLOC was documented. Contrary to the effect of experience in formal learning, experience with chronic disease did not alter developmental progression in these health-related areas. Our results suggest that in communicating with children about illness, the pediatrician's approach should not be altered by an appearance of superficial sophistication that some children may acquire as part of their experience with chronic disease. 相似文献
58.
Bas B. Oude Munnink Roel H.T. Nijhuis Nathalie Worp Marjan Boter Babette Weller Babs E. Verstrepen Corine GeurtsvanKessel Maarten F. Corsten Anne Russcher Marion Koopmans 《Emerging infectious diseases》2022,28(9):1920
We detected a highly divergent SARS-CoV-2 Alpha variant in an immunocompromised person several months after the latest detection of the Alpha variant in the Netherlands. The patient was infected for 42 weeks despite several treatment regimens and disappearance of most clinical symptoms. We identified several potential immune escape mutations in the spike protein. 相似文献
59.
1. The virus of vaccinia in so called roller tube cultures of mixed embryonic chick tissue rapidly increases to maximal titre. 2. Under these conditions the quantity of virus in the tissue remains at or near the maximum for at least 9 weeks and considerable amounts are present in the fluids removed each day. 3. The same results are obtained when only fragments of embryonic chick heart are employed. 4. Many, though not necessarily all, of the cells in infected cultures remain alive and retain the capacity to proliferate. The presence of these living cells is essential for the persistence of the virus. 5. No apparent differences in the rate or amount of growth of cells in infected as contrasted with non-infected cultures can be discerned in the gross. 6. It is suggested, but not proved, that virus is continually being produced rather than simply preserved throughout the period. 相似文献
60.