全文获取类型
收费全文 | 3248篇 |
免费 | 176篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 108篇 |
妇产科学 | 112篇 |
基础医学 | 605篇 |
口腔科学 | 77篇 |
临床医学 | 245篇 |
内科学 | 550篇 |
皮肤病学 | 68篇 |
神经病学 | 233篇 |
特种医学 | 259篇 |
外科学 | 359篇 |
综合类 | 36篇 |
预防医学 | 178篇 |
眼科学 | 48篇 |
药学 | 261篇 |
中国医学 | 3篇 |
肿瘤学 | 273篇 |
出版年
2021年 | 55篇 |
2020年 | 37篇 |
2019年 | 32篇 |
2018年 | 51篇 |
2017年 | 37篇 |
2016年 | 56篇 |
2015年 | 55篇 |
2014年 | 71篇 |
2013年 | 111篇 |
2012年 | 130篇 |
2011年 | 139篇 |
2010年 | 106篇 |
2009年 | 109篇 |
2008年 | 156篇 |
2007年 | 173篇 |
2006年 | 131篇 |
2005年 | 125篇 |
2004年 | 117篇 |
2003年 | 135篇 |
2002年 | 111篇 |
2001年 | 92篇 |
2000年 | 77篇 |
1999年 | 102篇 |
1998年 | 52篇 |
1997年 | 59篇 |
1996年 | 44篇 |
1995年 | 36篇 |
1994年 | 31篇 |
1993年 | 29篇 |
1992年 | 78篇 |
1991年 | 45篇 |
1990年 | 51篇 |
1989年 | 59篇 |
1988年 | 34篇 |
1987年 | 38篇 |
1986年 | 38篇 |
1985年 | 48篇 |
1984年 | 34篇 |
1983年 | 23篇 |
1982年 | 27篇 |
1979年 | 18篇 |
1978年 | 25篇 |
1977年 | 22篇 |
1976年 | 28篇 |
1975年 | 17篇 |
1974年 | 20篇 |
1973年 | 18篇 |
1972年 | 31篇 |
1971年 | 27篇 |
1970年 | 18篇 |
排序方式: 共有3474条查询结果,搜索用时 10 毫秒
1.
2.
Jens J Bock Peter Maurer Cornelia Otto Robert A W Fuhrmann Johannes Schubert 《Journal of cranio-maxillo-facial surgery》2006,34(3):156-161
AIM: The aim of this study was to analyse possible intra- and postoperative complications and long-term results in combined orthodontic-orthognathic treatment of mentally handicapped patients compared with a control group of patients without handicap. PATIENTS AND METHODS: A group of 20 mentally handicapped patients (male = 7, female = 13) and of 102 non-handicapped patients (male = 36, female = 66) were evaluated retrospectively. The results of the two point-discrimination sensory test and the cephalometric findings of both groups were assessed. Complications during and after the operation, the results of nerve function tests and relapse rates were reported. The statistical analysis was carried out using binary logistical regression analysis with adjustment according to the diagnosis and the type of operation (p < 0.05) RESULTS: No significant differences could be found between the mentally handicapped and the non-handicapped patients. Only the nerve function test immediately postoperatively revealed differences between the two patient groups. The relapse rate in mentally handicapped patients was similar to non-handicapped patients. Forty-seven months after the operation, relapse (change in the ANB angle of more than 0.5 degrees ) was observed in four patients only (handicapped patients). CONCLUSION: Orthognathic surgical procedures in mentally handicapped patients can be carried out with a similarly high success rate as in mentally healthy patients. 相似文献
3.
4.
Dioxinlike components in incinerator fly ash: a comparison between chemical analysis data and results from a cell culture bioassay.
下载免费PDF全文
![点击此处可从《Environmental health perspectives》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Till P Behnisch H Hagenmaier K W Bock D Schrenk 《Environmental health perspectives》1997,105(12):1326-1332
Potent polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxinlike polychlorinated biphenyls (PCBs) are among the most relevant toxic emissions from incinerators. Induction of cytochrome P450 1A1-catalyzed 7-ethoxyresorufin O-deethylase (EROD) activity in mammalian cell culture (EROD bioassay) is thought to be a selective and sensitive parameter used for the quantification of dioxinlike compounds. Fly ash extracts from municipal waste incinerators (MWI), a crematorium, wood combustors, and a noble metal recycling facility were analyzed in the EROD bioassay using rat hepatocytes in primary culture. Fractions containing 2,3,7,8-substituted PCDDs/PCDFs, dioxinlike PCBs, and 16 major polycyclic aromatic hydrocarbons (PAHs) were isolated from the extract and analyzed by gas chromatography-mass spectrometry (GC-MS) and by the EROD bioassay. It was found that with MWI samples the bioassay of the extract resulted in a two- to fivefold higher estimate of TCDD equivalents (TEQ) than the chemical analysis of PCDDs/PCDFs and PCBs. However, the outcome of both methods was significantly correlated, making the bioassay useful as a rough estimate for the sum of potent PCDDs/PCDFs and dioxinlike PCBs in extracts from MWI fly ash samples and in a fly ash sample from a crematorium. In noble metal recycling facility and wood combustor samples, higher amounts of PAHs were found, contributing to more pronounced differences between the results of both methods. The remaining unexplained inducing potency in fly ash samples probably results from additional dioxinlike components including certain PAHs not analyzed in this study.The hypothesis that emissions from MWI of hitherto unidentified dioxinlike compounds are higher by orders of magnitude than emissions of potent PCDDs/PCDFs and dioxinlike PCBs could not be confirmed. We found no indication for a marked synergistic interaction of dioxinlike fly ash components in the bioassay. 相似文献
5.
6.
Klaus Edvardsen Nils Brünner Mogens Spang-Thomsen Frank S. Walsh Elisabeth Bock 《International journal of developmental neuroscience》1993,11(5)
A cDNA encoding a transmembrane 140 kDa isoform of the neural cell adhesion molecule, NCAM, was transfected into the rat glioma cell line BT4Cn. Transfectants with a homogeneously high expression of NCAM-B showed a decreased capacity for penetration of an artificial basement membrane when compared to cells transfected with expression-vector alone or untransfected cells. However, when injected subcutaneously into nude mice, both NCAM expressing cells and control cells produced invasive tumors. Nude mice injected with NCAM positive cells developed tumors with slower growth rates as compared to those induced by NCAM negative cells. This implies that NCAM may not only be involved in adhesive and motile behaviour of glioma cells, but also in their growth regulation. 相似文献
7.
Margaretha Jennerwein Ronald Gust Richard Müller Helmut Schnenberger Jürgen Engel Martin R. Berger Dietrich Schmhl Siegfried Seeber Reinhanidt Osieka Ghanem Atassi Danile Marchal-De Bock 《Archiv der Pharmazie》1989,322(2):67-73
The activity of stereoisomeric [1,2-bis(3-hydroxyphenyl)ethylenediamine] dichloroplatinum(II)-complexes (1-PtCl2,R,S; 2-PtCl2, R,R/S,S; 3-PtCl2, R,R; 4-PtCl2, S,S) on several tumor models (MDA-MB 231 breast cancer cell line; P 388 leukemia, mouse; L 1210 leukemia, mouse; L 5222 leukemia, rat; Ehrlich ascites tumor, mouse--wildtype; cisplatin-, etoposide-, cyclophosphamide-, and daunomycin-resistant, resp.) is described. For comparison the analogous [1,2-bis(4-hydroxyphenyl)ethylendiamine]dichloroplatinum (II)-complexes (5-PtCl2, R, S; 6-PtCl2, R,R/S,S; 7-PtCl2, R,R; 8-PtCl2, S,S) and cisplatin are used. 1-PtCl2 to 4-PtCl2 (OH in 3,3'-positions) show their maximum antitumor effect at lower doses than 5-PtCl2 to 8-PtCl2 (OH in 4,4'-positions). 2-PtCl2 and 6-PtCl2 (R,R/S,S) are more active than 1-PtCl2 and 5-PtCl2 (R,S). 4-PtCl2 and 8-PtCl2 (S,S) are superior to 3-PtCl2 and 7-PtCl2 (R,R). On the L 5222 leukemia 2-PtCl2 (R,R/S,S), 4-PtCl2 (S,S) and 8-PtCl2 (S,S) markedly surpass cisplatin. Strong effects are produced by 2-PtCl2 to 4-PtCl2 on the Ehrlich ascites tumor (wildtype, cisplatin-, etoposide-, cyclophosphamide-, and daunomycin-resistant, resp.). The combination of 4-PtCl2 with cisplatin results in a weakly synergistic effect. 相似文献
8.
9.
Thorsten Grund Konrad Lehmann Nathalie Bock Aribert Rothenberger Gertraud Teuchert-Noodt 《Behavioral and brain functions : BBF》2006,2(1):2-14
Methylphenidate (MPH) is the most commonly used drug to treat attention deficit/hyperactivity disorder (ADHD) in children
effectively and safely. In spite of its widespread application throughout one of the most plastic and sensitive phases of
brain development, very little is known to date about its long-term effects on brain structure and function. Hence, this short
review updates the influence of MPH on brain development, since recent human and animal studies suggest that MPH alters the
dopaminergic system with long-term effects beyond the termination of treatment. 相似文献
10.
Jan Petr Jan Kybic Michael Bock Sven Müller Václav Hlavác 《Magnetic resonance in medicine》2007,58(3):582-591
A new reconstruction method for parallel MRI called PROBER is proposed. The method PROBER works in an image domain similar to methods based on Sensitivity Encoding (SENSE). However, unlike SENSE, which first estimates the spatial sensitivity maps, PROBER approximates the reconstruction coefficients directly by B-splines. Also, B-spline coefficients are estimated at once in order to minimize the reconstruction error instead of estimating the reconstruction in each pixel independently (as in SENSE). This makes the method robust to noise in reference images. No presmoothing of reference images is necessary. The number of estimated parameters is reduced, which speeds up the estimation process. PROBER was tested on simulated, phantom, and in vivo data. The results are compared with commercial implementations of the algorithms SENSE and GRAPPA (Generalized Autocalibrating Partially Parallel Acquisitions) in terms of elapsed time and reconstruction quality. The experiments showed that PROBER is faster than GRAPPA and SENSE for images wider than 150x150 pixels for comparable reconstruction quality. With more basis functions, PROBER outperforms both SENSE and GRAPPA in reconstruction quality at the cost of slightly increased computational time. 相似文献