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   3380篇
  免费   109篇
  国内免费   9篇
耳鼻咽喉   33篇
儿科学   65篇
妇产科学   12篇
基础医学   442篇
口腔科学   67篇
临床医学   222篇
内科学   918篇
皮肤病学   47篇
神经病学   270篇
特种医学   151篇
外科学   549篇
综合类   9篇
预防医学   79篇
眼科学   30篇
药学   251篇
  1篇
中国医学   1篇
肿瘤学   351篇
  2023年   19篇
  2022年   32篇
  2021年   68篇
  2020年   36篇
  2019年   52篇
  2018年   39篇
  2017年   52篇
  2016年   51篇
  2015年   41篇
  2014年   68篇
  2013年   73篇
  2012年   164篇
  2011年   167篇
  2010年   88篇
  2009年   69篇
  2008年   151篇
  2007年   152篇
  2006年   167篇
  2005年   143篇
  2004年   137篇
  2003年   141篇
  2002年   135篇
  2001年   104篇
  2000年   112篇
  1999年   126篇
  1998年   35篇
  1997年   35篇
  1996年   41篇
  1995年   21篇
  1994年   24篇
  1993年   31篇
  1992年   90篇
  1991年   99篇
  1990年   86篇
  1989年   78篇
  1988年   73篇
  1987年   68篇
  1986年   40篇
  1985年   61篇
  1984年   27篇
  1983年   27篇
  1982年   14篇
  1979年   23篇
  1978年   18篇
  1975年   16篇
  1974年   19篇
  1972年   18篇
  1969年   24篇
  1968年   16篇
  1967年   22篇
排序方式: 共有3498条查询结果,搜索用时 15 毫秒
81.
82.
83.
We report on two children with acute encephalopathy showing mild clinical manifestations and reversible white matter lesions. In both patients, MRI revealed high intensities on T (2)-weighted imaging and marked reductions of water diffusion in the white matter of the bilateral centrum semiovale and the corpus callosum. These abnormalities disappeared along with the neurological symptoms within a week in both patients. These children represent a characteristic group of patients among childhood acute encephalopathy.  相似文献   
84.
Acute graft-versus-host disease (aGVHD) remains a major complication of allogeneic bone marrow transplantation, which is caused by donor T cells specific for host alloantigens. In a murine model, we found that donor T cells expressed a natural killer cell inhibitory receptor, CD94/NKG2A, during the course of aGVHD. Administration of an anti-NKG2A mAb markedly inhibited the expansion of donor T cells and ameliorated the aGVHD pathologies. These results suggested that the CD94/NKG2A inhibitory receptor expressed on host-reactive donor T cells can be a novel target for the amelioration of aGVHD.  相似文献   
85.
Previous reports have shown the expression of several mechanosensitive ionic channels on the plasma membrane in odontoblasts, which are the cells responsible for dentin formation. The membrane characteristics of odontoblasts imply that they could play critical roles in the mechano-transduction of fluid displacement within dentinal tubules into the electrical cell signals, to carry dentin sensation to the central nervous system. However, the direct ionic mechanism underlying such a dentin nociceptive function remains unclear. In the present study, we investigated the expression of the transient receptor potential vanilloid subfamily member 1 (TRPV1) channel - which essentially contributes to the detection of pain sensation - in rat odontoblasts by immunohistochemical and nystatin perforated patch-clamp techniques. Immunohistochemical observation showed the localization of TRPV1-immunoreactions on the distal regions of odontoblast membranes. In the patch-clamp experiments, we observed capsaicin-induced inward currents that were inhibited by capsazepine, a TRPV1 channel antagonist. Our results indicate a significant expression of TRPV1 channels in odontoblasts, suggesting that odontoblasts may directly respond to noxious stimuli such as a thermal-heat stimulus, and point to the necessity for a reconsideration of the cellular mechanisms of dentin sensation based on the transmembrane ionic signals in odontoblasts.  相似文献   
86.
Cyclosporin A absorption profiles in children with nephrotic syndrome   总被引:1,自引:0,他引:1  
A single blood concentration measurement of Neoral 2 h after administration (C2) is a new concept in therapeutic drug monitoring (TDM). In most adult patients, the concentration of cyclosporin A (CyA) peaks within 2 h after Neoral administration. Therefore, monitoring the area under the concentration-time curve over the first 4 h post-dose (AUC0–4) is considered to be the most reliable strategy for Neoral TDM. In addition, C2 is considered to be the most accurate predictor of AUC0–4, with which C2 correlates best. Thus, in adult patients, C2 monitoring is recommended as the best single-point TDM method for Neoral. However, in paediatric patients, the effectiveness of C2 monitoring is still unclear. We examined the trough concentration (C0), C1, C2, C3, and C4 of CyA in 60 patients (1 to 20 years old, mean age 7.42±0.67 years) who had nephrotic syndrome treated with Neoral. The peak concentration of C0-C4 was C1 or C2 in 38 patients (early peak group) and C3 or C4 in 22 patients (late peak group). C2 in the late peak group was significantly lower than that in the early peak group (422±50.1 vs. 665 ±53.8 ng/ml, P =0.0008), although the administered doses of Neoral and C0 were similar between these groups. Therefore, TDM by C2 using the same standard as in the early peak group might result in an overdose of CyA in the late peak group. As the concentration peaked at 3 h or more after Neoral administration in the late peak group, AUC0–4 does not necessarily reflect the Neoral absorption profile. As more than 33% of the paediatric patients were in the late peak group, TDM by AUC0–4 or C2 should be used carefully in paediatric patients treated with Neoral.  相似文献   
87.
OBJECTIVE: Liver regeneration after hepatectomy is correlated with liver fibrosis. Retrospectively, we compared three quantitative indices (HH15, LHL15 and LU15) of Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (Tc-99m-GSA) liver scintigraphy with liver fibrosis; in particular, we compared the HH15 index and the rate of remnant liver regeneration. METHODS: Fifty-three patients who had undergone hepatectomy were enrolled in this study. The non-neoplastic parts of their resected specimens were divided into 5 groups (F0-F4) according to the degree of liver fibrosis, as determined using the New Inuyama classification system: F0, no fibrosis (n = 12); F1, portal fibrosis widening (n = 12); F2, portal fibrosis widening with bridging fibrosis (n = 14); F3, bridging fibrosis plus lobular distortion (n = 7); F4, liver cirrhosis (n = 8). RESULTS: When the cases were divided into a no or mild fibrosis group (F0 and F1) and a moderate or severe fibrosis or cirrhosis group (F2, F3 and F4), all of the indices were significantly different between the two groups. In this analysis, the areas (Az) under the receiver operating characteristic (ROC) curves for the HH15 and LHL15 indices were very similar, while the Az for the LU15 index was smaller. An HH15 index equal to 0.52 was the most accurate, producing a 79.3% sensitivity and a 75.0% specificity rating. When 18 patients that had received a CT scan one month after hepatectomy were divided into 2 groups according to their HH15 value (group A, HH15 < or = 0.52; group B, HH15 > 0.52), group A exhibited a better regeneration rate. CONCLUSION: Tc-99m-GSA scintigraphy is well correlated with liver fibrosis and may be useful for non-invasive, preoperative evaluations of liver fibrosis. The HH15 index, in particular, may be useful for predicting the rate of liver regeneration after hepatectomy.  相似文献   
88.
To examine the effects of change in meteorological parameters on pain-related behaviors in a simulated arthritic condition, rats with an injection of complete Freund's adjuvant into the tibio-tarsal joint were exposed to low barometric pressure (20 mmHg below the natural atmospheric pressure) and low ambient temperature (7 degrees C lower than 22 degrees C) in a climate-controlled room. When the arthritic rats were exposed to these environments, the already increased number of hindpaw withdrawals in response to noxious mechanical stimulation (hyperalgesia) was further increased, and a hindpaw withdrawal response to innocuous mechanical stimulation (allodynia) began to occur. Such exposures did not influence any of the pain-related behaviors of the control rats. These results show that lowering barometric pressure and ambient temperature within the range of natural environmental fluctuation intensify pain in arthritic rats.  相似文献   
89.
We compared the nutritional status of children aged 1-5 years from slums attending two day-care centres (DCCs) in Nepal (one in an urban slum area) with that of non-attendees to evaluate the impact of supplementary feeding. We measured the anthropometrics of 23 children attending two DCCs and 23 matched controls from the same neighbourhood and interviewed their mothers. We found a better nutritional status, particularly the height-for-age Z-score, among the attendees of the DCC with children's longer attendance, but no difference at the other, although attendees who had been fed for longer tended to show better nutrition. Our study indicates that in the least developed countries good quality day-care of sufficient duration has the potential to improve child nutrition.  相似文献   
90.
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