首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   345篇
  免费   4篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   1篇
基础医学   33篇
口腔科学   41篇
临床医学   28篇
内科学   32篇
神经病学   11篇
特种医学   14篇
外科学   135篇
综合类   15篇
预防医学   6篇
眼科学   7篇
药学   7篇
肿瘤学   9篇
  2018年   3篇
  2016年   2篇
  2015年   9篇
  2014年   10篇
  2013年   21篇
  2012年   13篇
  2011年   8篇
  2010年   12篇
  2009年   2篇
  2008年   15篇
  2007年   6篇
  2005年   2篇
  2004年   5篇
  2003年   3篇
  2002年   4篇
  1999年   6篇
  1998年   4篇
  1997年   10篇
  1996年   4篇
  1995年   8篇
  1994年   2篇
  1993年   4篇
  1992年   6篇
  1991年   3篇
  1990年   8篇
  1989年   6篇
  1988年   3篇
  1987年   5篇
  1986年   7篇
  1985年   5篇
  1984年   6篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1979年   3篇
  1978年   5篇
  1977年   11篇
  1976年   14篇
  1975年   12篇
  1974年   10篇
  1973年   12篇
  1972年   14篇
  1971年   9篇
  1970年   13篇
  1969年   6篇
  1968年   3篇
  1967年   4篇
  1966年   7篇
  1965年   3篇
  1964年   3篇
排序方式: 共有349条查询结果,搜索用时 31 毫秒
1.
2.
Oscillatory motion of the normal cervical spinal cord   总被引:2,自引:0,他引:2  
  相似文献   
3.
4.
It has previously been shown that, in the heterozygous state, mutations in the SOX9 gene cause campomelic dysplasia (CD) and the often associated autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one recurrent mutation were characterized in one SOX9 allele each, and in one case, no mutation was found. Four missense mutations are all located within the high mobility group (HMG) domain. They either reduce or abolish the DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense and three frameshift mutations identified, two leave the C-terminal transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or almost completely intact. When tested in cell transfection experiments, the recurrent nonsense mutation Y440X, found in two patients who survived for four and more than 9 years, respectively, exhibits some residual transactivation ability. In contrast, a frameshift mutation extending the protein by 70 residues at codon 507, found in a patient who died shortly after birth, showed no transactivation. This is apparently due to instability of the mutant SOX9 protein as demonstrated by Western blotting. Amino acid substitutions and nonsense mutations are found in patients with and without XY sex reversal, indicating that sex reversal in CD is subject to variable penetrance. Finally, none of 18 female patients with XY gonadal dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP assays, providing evidence that SOX9 mutations do not usually result in XY sex reversal without skeletal malformations.   相似文献   
5.
6.
7.

Back ground

Stroke produces a wide range of mental and emotional disorders. Neuropsychiatric complications associated with stroke may have negative effects on the social functioning, overall quality of life and the recovery of motor functioning of stroke survivors.

Objective

To determine the prevalence and nature of psychiatric morbidity among stroke patients attending neurology outpatient clinic of the University of Ilorin Teaching Hospital (UITH), Ilorin-Nigeria.

Methods

All patients with stroke aged 18 years and above at an outpatient neurology clinic in Ilorin, Nigeria were assessed for mental and emotional disorders using the Schedule for Clinical Assessment in Neuropsychiatry (SCAN) over one year (March 2009 to February 2010).

Results

Overall prevalence of psychiatric morbidity was 36.0% (30/83) among 83 patients who constituted the study population. Specific diagnoses recorded were depression (19.2%), generalised anxiety disorder (9.6%), harmful alcohol use (2.4%); dementia, somatoform disorder, phobia and delusional disorder each had a prevalence of 1.2%. Clinical and sociodemographic variables were not significantly associated with psychiatric morbidity.

Conclusion

Psychiatric disorders are often associated with stroke. Identifying and treating stroke patients with these psychiatric co-morbidities could thus help to improve the overall quality of life of these patients.  相似文献   
8.
Photocatalysts based on zinc hydroxide and a solid solution of CdS and ZnS were prepared via the precipitation method and used for photocatalytic hydrogen production from aqueous solutions of inorganic (Na2S/Na2SO3) and organic (ethanol) sacrificial agents. The photocatalysts were tested in cyclic experiments for hydrogen evolution and studied using X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) techniques. Different transformations of the β-Zn(OH)2 co-catalyst were observed in the presence of inorganic and organic sacrificial agents; namely, ZnS was formed in Na2S/Na2SO3 solution, whereas the formation of ε-Zn(OH)2 was detected in solution with ethanol. The composite Zn(OH)2/Cd1−xZnxS photocatalysts have great potential in various photocatalysis processes (e.g., hydrogen production, CO2 reduction, and the oxidation of organic contaminants) under visible light.

The nature of the sacrificial agent affects the transformations of a Zn(OH)2 co-catalyst during photocatalytic hydrogen production.  相似文献   
9.
A sol-gel technique was applied to prepare the two-component oxide system Cu-Mg-O, where MgO plays the role of oxide matrix, and CuO is an active chemical looping component. The prepared samples were characterized by scanning electron microscopy, low-temperature nitrogen adsorption, and X-ray diffraction analysis. The reduction behavior of the Cu-Mg-O system was examined in nine consecutive reduction/oxidation cycles. The presence of the MgO matrix was shown to affect the ability of CuO towards reduction and re-oxidation significantly. During the first reduction/oxidation cycle, the main characteristics of the oxide system (particle size, crystallization degree, etc.) undergo noticeable changes. Starting from the third cycle, the system exhibits a stable operation, providing the uptake of similar hydrogen amounts within the same temperature range. Based on the obtained results, the two-component Cu-Mg-O system can be considered as a prospective chemical looping agent.  相似文献   
10.
Summary Using an indirect lymphokin-assay, the leucocyte-migration-inhibition-test (LMI-test), the cellular sensitization of fertile and infertile patients before and after homologous and heterologous intrauterine insemination (IUI) was investigated. In this assay several preparations of spermatozoa (“washed”-, “swim-up”- and “pellet”-spermatozoa) in different concentrations (1, 5 and 10×106 sperms/ml culture medium) and seminal plasma were tested as antigen. In all investigated groups a cellular immune response against spermatic antigen was demonstrable and seemed to be dose dependent. In contrast to fertile women who reacted with an enhancement of the macrophage migration for low concentrations the same concentration of antigen induced an inhibition of macrophage migration in fertile patients. For high concentrations of spermatic antigens there was a difference in the intensity of cell-mediated immune response between fertile and infertile women. Since infertile patients demonstrated an increased level of cell-mediated immune response it is possible that infertility may be caused by this altered immunological reaction. This response changes after multiple IUI-treatment and that change might be caused by the high concentration of spermatic antigens as there was a difference in the intensity of cell-mediated immune response between fertile and infertile women. Since infertile patients demonstrated an increased level of cell-mediated immune response it is possible that infertility may be caused by this altered immunological reaction. This response changes after multiple IUI-treatment and that change might be caused by the high concentration of spermatozoa. The immunological response of infertile patients seems to be similar in those receiving husband and donor IUI.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号