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   1008篇
  免费   38篇
  国内免费   4篇
耳鼻咽喉   2篇
儿科学   30篇
妇产科学   12篇
基础医学   157篇
口腔科学   4篇
临床医学   37篇
内科学   201篇
皮肤病学   17篇
神经病学   81篇
特种医学   17篇
外科学   258篇
综合类   1篇
预防医学   20篇
眼科学   11篇
药学   94篇
中国医学   7篇
肿瘤学   101篇
  2023年   5篇
  2022年   9篇
  2021年   24篇
  2020年   11篇
  2019年   26篇
  2018年   17篇
  2017年   23篇
  2016年   11篇
  2015年   15篇
  2014年   18篇
  2013年   22篇
  2012年   58篇
  2011年   54篇
  2010年   33篇
  2009年   28篇
  2008年   47篇
  2007年   67篇
  2006年   71篇
  2005年   57篇
  2004年   73篇
  2003年   70篇
  2002年   56篇
  2001年   19篇
  2000年   29篇
  1999年   21篇
  1998年   17篇
  1997年   19篇
  1996年   16篇
  1995年   13篇
  1994年   21篇
  1993年   8篇
  1992年   14篇
  1991年   6篇
  1990年   9篇
  1989年   12篇
  1988年   8篇
  1987年   5篇
  1986年   6篇
  1985年   3篇
  1984年   8篇
  1983年   6篇
  1982年   1篇
  1981年   1篇
  1980年   4篇
  1978年   2篇
  1977年   1篇
  1975年   2篇
  1973年   2篇
  1967年   1篇
  1957年   1篇
排序方式: 共有1050条查询结果,搜索用时 203 毫秒
1.
2.
3.
This study was designed to examine human subjects' ability to discriminate between spatially different bite pressures. We measured actual bite pressure distribution when subjects simultaneously bit two silicone rubber samples with different hardnesses using their right and left incisors. They were instructed to compare the hardness of these two rubber samples and indicate which was harder (right or left). The correct-answer rates were statistically significant at P < 0.05 for all pairs of different right and left silicone rubber hardnesses. Simultaneous bite measurements using a multiple-point sheet sensor demonstrated that the bite force, active pressure and maximum pressure point were greater for the harder silicone rubber sample. The difference between the left and right was statistically significant (P < 0.05) for all pairs with different silicone rubber hardnesses. We demonstrated for the first time that subjects could perceive and discriminate between spatially different bite pressures during a single bite with incisors. Differences of the bite force, pressure and the maximum pressure point between the right and left silicone samples should be sensory cues for spatial hardness discrimination.  相似文献   
4.
5.
We present six cases of antimelanoma differentiation‐associated gene 5 antibody (anti‐MDA5‐Ab)‐positive clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP‐ILD), which is known to have a poor prognosis. The outcomes of these cases are described after treatment with therapeutic plasma exchange (TPE). Clinical and therapeutic data for patients with CADM with RP‐ILD were collected retrospectively from medical records. All six patients received early intensive care including high‐dose corticosteroids, intravenous cyclophosphamide, and a calcineurin inhibitor, but lung disease and hypoxia became more severe. TPE was performed over a median of 9.5 sessions (range 3‐14) per patient, and the median duration from admission to TPE was 23 days. Three patients received combined direct hemoperfusion using a polymyxin B‐immobilized fiber column (PMX‐DHP) therapy on successive days to manage acute respiratory failure. Four patients survived and two died due to respiratory failure. In the survival cases, ferritin decreased, and ferritin and KL‐6 were lower at diagnosis. The patients who died had a higher alveolar‐arterial oxygen difference and more severe lung lesions at the time of initiation of TPE. These findings indicate that a combination of conventional therapy and TPE may be useful for improvement of the prognosis of CADM with RP‐ILD at the early stage of onset.  相似文献   
6.
7.
Association of congenital cytomegalovirus (CMV) infection with autism spectral disorder (ASD) has been suggested since 1980s. Despite the observed association, its role as a risk factor for ASD remains to be defined. In the present review, we systematically evaluated the available evidence associating congenital CMV infection with ASD using PubMed, Web of Science, Cochrane Library, and Embase databases. Any studies on children with CMV infection and ASD were evaluated for eligibility and three observational studies were included in meta-analysis. Although a high prevalence of congenital CMV infection in ASD cases (OR 11.31, 95% CI 3.07–41.66) was indicated, too few events (0–2 events) in all included studies imposed serious limitations. There is urgent need for further studies to clarify this issue.  相似文献   
8.
9.

The envelope proteins of the hepatitis C virus (HCV), E1 and E2, have been revealed to be essential for invasion of HCV. Thus, we were engaged in the search for the inhibitors against HCV invasion through the assay system using the model virus expressing recombinant HCV envelopes, E1 and E2. Now, we disclosed dimeric hydrolysable tannin oenothein B (1) from MeOH extract of Oenothera erythrosepala as an active principle for inhibition of HCV invasion and its potency was almost the same as that of monomeric hydrolysable tannin, tellimagrandin I (2). Furthermore, by use of stereoselectively prepared 1-β- and 1-α-O-methyl tellimagrandin Is (4 and 5), the introduction of methyl moiety into 1-hydroxy group of 2 was clarified to result in slightly reduction of activity and β-isomer was revealed to exhibit a little stronger activity than α-one.

  相似文献   
10.
Signal regulatory protein α (SIRPα) is expressed predominantly on type 2 conventional dendritic cells (cDC2s) and macrophages. We previously showed that mice systemically lacking SIRPα were resistant to experimental autoimmune encephalomyelitis (EAE). Here, we showed that deletion of SIRPα in CD11c+ cells of mice (SirpaΔDC mice) also markedly ameliorated the development of EAE. The frequency of cDCs and migratory DCs (mDCs), as well as that of Th17 cells, were significantly reduced in draining lymph nodes of SirpaΔDC mice at the onset of EAE. In addition, we found the marked reduction in the number of Th17 cells and DCs in the CNS of SirpaΔDC mice at the peak of EAE. Whereas inducible systemic ablation of SIRPα before the induction of EAE prevented disease development, that after EAE onset did not ameliorate the clinical signs of disease. We also found that EAE development was partially attenuated in mice with CD11c+ cell-specific ablation of CD47, a ligand of SIRPα. Collectively, our results suggest that SIRPα expressed on CD11c+ cells, such as cDC2s and mDCs, is indispensable for the development of EAE, being required for the priming of self-reactive Th17 cells in the periphery as well as for the inflammation in the CNS.  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