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   2425篇
  免费   99篇
  国内免费   33篇
耳鼻咽喉   53篇
儿科学   185篇
妇产科学   143篇
基础医学   255篇
口腔科学   69篇
临床医学   204篇
内科学   541篇
皮肤病学   92篇
神经病学   201篇
特种医学   77篇
外科学   291篇
综合类   41篇
预防医学   67篇
眼科学   105篇
药学   108篇
中国医学   6篇
肿瘤学   119篇
  2024年   3篇
  2023年   18篇
  2022年   37篇
  2021年   57篇
  2020年   40篇
  2019年   56篇
  2018年   74篇
  2017年   50篇
  2016年   89篇
  2015年   114篇
  2014年   99篇
  2013年   129篇
  2012年   184篇
  2011年   228篇
  2010年   103篇
  2009年   89篇
  2008年   202篇
  2007年   208篇
  2006年   218篇
  2005年   165篇
  2004年   151篇
  2003年   111篇
  2002年   99篇
  2001年   6篇
  2000年   5篇
  1999年   17篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
排序方式: 共有2557条查询结果,搜索用时 15 毫秒
91.
Multiple sulfatase deficiency is biochemically characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The gene sulfatase-modifying factor 1 (SUMF1), recently identified, encodes the enzyme responsible for post-translational modification of a cysteine residue, which is essential for the activity of sulfatases. We describe clinical findings and mutation analysis of four patients. The patients presented with hypotonia, developmental delay, coarse face, ichthyosis, and hepatosplenomegaly. The diagnosis was made through clinical findings, enzymatic assays, and mutation analysis. We were detected to be homozygous for a novel missense mutation c. 739G > C causing a p.G247R amino acid substitution in the SUMF1 protein.Key Words: Child, multiple sulfatase deficiency, sulfatase-modifying factor 1 gene  相似文献   
92.
Objective The aim of the study was to compare safety, efficacy and tolerability of risperidone with haloperidol in the treatment of Autistic Disorder (AD). Method This study was designed as a double-blind, prospective, for a 12-week period. A total of 30 subjects, between the ages of 8 and 18 with AD based on DSM IV criteria, were included in the study. Behavioral Rating Scales were performed by the investigators and the parents. Safety assessment included vital signs, electrocardiogram, electroencephalogram, adverse events, laboratory tests, extrapyramidal symptoms and the side effects. Both treatments were applied in a once daily dosage regimen of 0.01–0.08 mg/kg/day. Results The reduction from baseline in Ritvo–Freeman Real Life Rating Scale (RF-RLRS), sensory motor (subscale I) and language (subscale V) scores were significant in risperidone group (P < 0.05). Compared to haloperidol, risperidone led to a significantly greater reduction in the Aberrant Behavior Checklist (ABC) and Turgay DSM-IV Pervasive Developmental Disorder (PDD) scale scores (P < 0.05 and P < 0.01). There was a greater increase of prolactin in the risperidone group, while alanine amino transferase (ALT) had further increased in the haloperidol group. Sensory motor behaviors (subscale I) and language at the end of the 12th week, RF-RLRS sensory motor and language subscale scores decreased in the risperidone group further than the other group (P < 0.05). Conclusions Risperidone was found to be more effective than haloperidol in the treatment of behavioral symptoms, impulsivity, language skills, and impaired social relations in children with AD. These results demonstrated that both drugs were safe and well tolerated in the treatment of AD.  相似文献   
93.
94.
95.
96.
BACKGROUND: The presence of hydrosalpinges is associated with lower implantation and pregnancy rates in women undergoing IVF-embryo transfer, while salpingectomy improves these parameters. Although the mechanism by which hydrosalpinges affects fertility is not entirely understood, an adverse effect on endometrial receptivity has been postulated. In this study, we hypothesized that the adverse effects of hydrosalpinges on fertility may be in part mediated by inappropriate endometrial expression of leukaemia inhibitory factor (LIF), a cytokine implicated in implantation. METHODS: In order to test our hypothesis, we prospectively examined the expression of LIF during the window of implantation in the endometrium of infertile women (n = 10) with hydrosalpinges prior to and following salpingectomy and of fertile controls (n = 10) by Western blotting and immunohistochemistry. RESULTS: LIF expression was significantly lower in infertile women with hydrosalpinges compared with fertile controls (P < 0.05). Salpingectomy resulted in an increase in LIF expression in eight out of 10 women with hydrosalpinges. LIF levels were increased by 231 +/-49% (mean +/- SEM) following salpingectomy. Immunohistochemical analysis confirmed the Western blot findings. The increased LIF immunoreactivity was predominantly localized to luminal and glandular epithelial cells. CONCLUSIONS: Our findings suggest that observed benefit from salpingectomy in infertile women with hydrosalpinges may be in part mediated by the up-regulation of endometrial LIF expression.  相似文献   
97.
98.
A multitude of antigens has been recently identified by screening of cDNA expression libraries derived from human tumors with autologous sera. Using a phage autoantibody assay and small panels of sera derived from cancer patients or controls it has been shown that some of these antigens display cancer-associated autoantibody responses. The diagnostic and prognostic significance of these potentially cancer-related autoantibodies remains unclear until large-scale assays are developed and serological data are available for hundreds of cancer patients and controls. The major bottleneck for the development of large-scale assays are the cloning, expression and the purification of each of the respective antigens. Due to these limitations and despite the potential clinical relevance large-scale autoantibody tests are established for only a few of these tumor antigens. Here we describe an enzyme-linked immunosorbent assay, Crude lysate ELISA (CrELISA), suitable for antigens identified by expression screening based on crude lysates of antigen-expressing bacteria. This assay permits sensitive and specific autoantibody seroscreening without the need of laborious and time-consuming cloning, expression and purification of recombinant proteins. CrELISA is robust and provides a versatile high throughput procedure for the rapid evaluation of multiple antigens in large-scale serology.  相似文献   
99.
100.
Ovarian torsion is a surgical emergency affecting not only the ipsilateral ovary but also contralateral ovary. Although the conventional treatment is salpingo-oophorectomy, recent studies advocate detorsion. We hypothesized that iloprost, an analogue of prostacyclin with cytoprotective properties, may prevent the harmful effects of ischaemia–reperfusion injury in bilateral ovaries after unilateral ovarian torsion–detorsion in rat. In this study, 24 female Wistar-albino female rats were divided into four groups. Ovarian torsion was produced by applying vascular clamps to right ovaries. In Group I, bilateral oophorectomy was performed. In group II, bilateral oophorectomy was performed after a unilateral torsion period of 4 h. In group III, bilateral ovaries were removed, following unilateral torsion–detorsion periods each lasted for 4 h. Saline was injected i.p. 30 min before detorsion. In group IV, same experimental protocol, which was conducted in group III, was repeated. Iloprost was injected i.p. 30 min before detorsion instead of saline in group IV. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), which are the indicators for oxidative stress were determined and histopathological evaluation was performed in bilateral ovaries in all groups. The MDA and NO levels for ipsilateral ovaries of four groups were compared and no significant difference was found (p>0.05). The same comparison were done for the contralateral sides and no difference was seen either (p>0.05). In histological examination, iloprost produced improvement in I/R-induced alterations in ipsilateral and contralateral ovaries. In conclusion, these results showed that iloprost has beneficial effect on the histological appearences in both the ipsilateral and contralateral rat ovaries after unilateral torsion–detorsion.  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