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   4564篇
  免费   298篇
  国内免费   30篇
耳鼻咽喉   30篇
儿科学   167篇
妇产科学   167篇
基础医学   676篇
口腔科学   85篇
临床医学   581篇
内科学   912篇
皮肤病学   85篇
神经病学   527篇
特种医学   98篇
外科学   384篇
综合类   38篇
一般理论   4篇
预防医学   445篇
眼科学   65篇
药学   256篇
中国医学   2篇
肿瘤学   370篇
  2024年   9篇
  2023年   63篇
  2022年   127篇
  2021年   222篇
  2020年   152篇
  2019年   177篇
  2018年   174篇
  2017年   118篇
  2016年   163篇
  2015年   150篇
  2014年   198篇
  2013年   264篇
  2012年   371篇
  2011年   365篇
  2010年   190篇
  2009年   180篇
  2008年   277篇
  2007年   341篇
  2006年   279篇
  2005年   257篇
  2004年   200篇
  2003年   193篇
  2002年   168篇
  2001年   23篇
  2000年   16篇
  1999年   24篇
  1998年   31篇
  1997年   21篇
  1996年   17篇
  1995年   17篇
  1994年   9篇
  1993年   13篇
  1992年   3篇
  1991年   7篇
  1990年   10篇
  1989年   4篇
  1988年   7篇
  1987年   3篇
  1986年   4篇
  1985年   5篇
  1983年   5篇
  1981年   4篇
  1980年   3篇
  1979年   3篇
  1978年   2篇
  1976年   3篇
  1975年   2篇
  1974年   3篇
  1973年   3篇
  1972年   3篇
排序方式: 共有4892条查询结果,搜索用时 15 毫秒
1.
2.
3.
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo.  相似文献   
4.
This study reports on the efficacy of a 'coma arousal procedure'. This procedure involved a programme of vigorous sensory stimulation administered to comatose patients by relatives using Comakits. An experimental group of 12 severely head-injured patients received the coma arousal procedure while a matched control group did not. Total duration of coma and weekly Glasgow Coma Scale Scores were recorded for the two groups. Results indicate that the total duration of coma was significantly shorter and that coma lightened more rapidly for the experimental group.  相似文献   
5.
Every child despite his individual differences and uniqueness is to be considered of equal worth. He should therefore be entitled to equal social, economic, civil and political rights, so that he may fully realise his inherent potential and share equally in life (Gill, 1979).

Obviously, these values are rooted in the humanistic philosophy of any nation's declaration of independence. In accordance with these value premises therefore “any act of commission or ommission by individuals, institutions or the society as a whole, and any conditions which deprive children of equal rights and liberties and interfere with their optimal development, constitutes by definition abuse or neglectful acts or conditions” (Gill, 1979).

Child abuse is a significant contemporary community problem. Although children have been maltreated throughout history, our community has been silent in defence of abused children. Child abuse is not a phenomenon of the 20th Century nor is it unique to our society and culture alone. It has occurred throughout the recorded history of man. The future of any nation depends on its children and their capabilities. For this reason, they must be given a full chance.  相似文献   
6.
7.
8.
Exploratory behavior (GMA) and habituation rate (IH) were studied in an open-field situation in normal and adrenalectomized rats. Following this procedure the rats were subjected to passive avoidance learning (PA). Wide-spreading individual differences were observed in the exploratory behavior and the tendency of habituation of normal rats. As compared to the normal values, either the adrenalectomy which was performed 24 hr, 7 days and 28 days prior to the experiments or the ACTH and hydrocortisone treatment failed to modify the GMA and the IH significantly. An improvement of PA was found in the normal rats following ACTH and hydrocortisone treatment. In the adrenalectomized animals the hydrocortisone proved to be effective, whereas ACTH did not influence PA. No correlation was found between GMA, IH versus PA values and the influence of ACTH and hydrocortisone administration on these parameters. It is concluded that the direction of PA is unpredictable on the basis of the open-field test performed on R-Amsterdam strain of rats, and the effect of ACTH on passive avoidance learning is mediated through the adrenal glands.  相似文献   
9.
Chronic distal spinal muscular atrophy (Chronic DSMA, MIM (*)607088) is a rare autosomal recessive disorder characterized by a progressive motor weakness and muscular atrophy, predominating in the distal parts of the limbs. A form of Chronic DSMA gene has been previously mapped to chromosome 11q13 in the 10.3 cM interval defined by loci D11S1889 and D11S1321. By linkage analysis in 12 European Chronic DSMA families, we showed that a disease gene maps to chromosome 11q13.3 (Z(max)=6.66 at theta=0.00 at the DSM4 locus) and suggested that this condition is genetically homogeneous. Recombination events allowed us to reduce the genetic interval to a 2.6 cM region, telomeric to the IGHMBP2 gene, excluding this gene as the disease causing gene in Chronic DSMA. Moreover, partial linkage disequilibrium was found between three rare alleles at loci D11S1369, DSM4 and D11S4184 and the mutant chromosome in European patients. Analysis of the markers at these loci strongly suggests that most Chronic DSMA chromosomes are derived from a single ancestor. Refinement of the Chronic DSMA locus will hopefully allow to test candidate genes and lead to identification of the disease-causing mutations.  相似文献   
10.
A new implant surface has been developed with the purpose of avoiding as much stress shielding as possible, and thus prolong the prosthesis lifespan. The aim of this study was to investigate the in vitro effect of this new ultra-high roughness and dense Titanium (Ti) surface (PG60, Ra = 74 microm) in comparison with medium (TI01, Ra = 18 microm) and high (TI60, Ra = 40 microm) roughness and open porous coatings; all the coatings were obtained by vacuum plasma spraying. MG63 osteoblast-like cells were seeded on the tested materials and polystyrene, as control, for 3 and 7 days. Cells proliferated on the material surfaces similarly to the control. Alkaline phosphatase activity had lower values for TI60 than TI01 (p < 0.0005) and PG60 (p < 0.005). Osteocalcin levels measured on TI60 were significantly (p < 0.0005) lower in comparison with TI01 and PG60 at 7 days. Procollagen-I synthesis reduced with increasing roughness and the lowest data was found for PG60. While at 3 days Transforming Growth Factor beta1 levels augmented with increasing roughness, at 7 days TI60, the high roughness surface, was significantly lower than PG60 (p < 0.005) and TI01 (p < 0.001). All tested materials showed significantly higher Interleukin-6 levels than those of polystyrene at both experimental times. Nitric Oxide activity on TI01 was significantly (p < 0.05) higher than on TI60 and polystyrene. In conclusion, the new ultra-high roughness and dense coating PG60 provided a good biological response, even though, at least in vitro, it behaved similarly to the coatings already used in orthopaedics.  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