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   7664篇
  免费   488篇
  国内免费   59篇
耳鼻咽喉   37篇
儿科学   185篇
妇产科学   80篇
基础医学   883篇
口腔科学   114篇
临床医学   557篇
内科学   1756篇
皮肤病学   140篇
神经病学   444篇
特种医学   173篇
外国民族医学   1篇
外科学   1619篇
综合类   207篇
一般理论   5篇
预防医学   494篇
眼科学   153篇
药学   773篇
中国医学   150篇
肿瘤学   440篇
  2023年   139篇
  2022年   112篇
  2021年   384篇
  2020年   328篇
  2019年   398篇
  2018年   425篇
  2017年   291篇
  2016年   301篇
  2015年   345篇
  2014年   412篇
  2013年   504篇
  2012年   771篇
  2011年   709篇
  2010年   331篇
  2009年   307篇
  2008年   453篇
  2007年   425篇
  2006年   362篇
  2005年   340篇
  2004年   255篇
  2003年   251篇
  2002年   126篇
  2001年   42篇
  2000年   30篇
  1999年   21篇
  1998年   16篇
  1997年   8篇
  1996年   11篇
  1995年   5篇
  1994年   9篇
  1993年   12篇
  1992年   5篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1988年   8篇
  1987年   4篇
  1986年   3篇
  1985年   6篇
  1984年   8篇
  1983年   3篇
  1982年   5篇
  1981年   10篇
  1980年   2篇
  1978年   4篇
  1977年   2篇
  1976年   3篇
  1975年   2篇
  1972年   3篇
  1969年   3篇
排序方式: 共有8211条查询结果,搜索用时 15 毫秒
1.
Hepatitis C virus(HCV)is a significant cause of hepatocellular carcinoma(HCC).The direct-acting antivirals marked a new era of HCV therapy and are associated with greater than 95%cure rate.Successful treatment of chronic hepatitis C greatly reduces the risk of HCC.A proportion of patients,especially those with pre-existing cirrhosis,remain at risk for HCC despite sustained virologic response(SVR).Diabetes mellitus,hepatic steatosis,alcohol consumption and lack of fibrosis regression are associated with risks of HCC after HCV cure.Noninvasive modalities such as aspartate aminotransferase to platelet ratio index and fibrosis-4 index and transient elastography have been used to monitor hepatic fibrosis.More recently,various fibrosis scores have been combined with clinical parameters and other novel biomarkers to predict risks of HCC for patients who achieved SVR.These models still need to be validated and standardized prior to applying to routine clinical care.  相似文献   
2.
Journal of Molecular Medicine - Non-alcoholic steatohepatitis (NASH), a chronic liver disease that emerged in industrialized countries, can further progress into liver fibrosis, cirrhosis, and...  相似文献   
3.
Therapy with immune checkpoint inhibitors (ICI) is effective in patients with metastatic mismatch-repair deficient (dMMR) colorectal cancer (CRC); however, data on treatment with neoadjuvant ICI in patients with locally advanced CRC are limited. From March 2019 to June 2020, five Danish oncological centers treated 10 patients with a treatment-naïve dMMR CRC with preoperative pembrolizumab, 9 with a nonmetastatic, unresectable colon cancer and 1 with a locally advanced rectum cancer. All 10 patients were evaluated regularly at a multidisciplinary team (MDT) meeting, and they all had a radical resection after a median of 8 cycles (range 2-13) of pembrolizumab. A microscopic evaluation of the resected tumors revealed no remaining tumor cells in five patients, while five still had tumor cells present. The patients were given no additional therapy. No recurrences were reported after a median follow-up of 26 months (range 23-38.5 months). Biopsies from Danish patients with CRC are routinely screened for dMMR proteins. In 2017, data from the Danish Colorectal Cancer Group showed that 19% (565/3000) of the patients with colon cancer and 1.5% (19/1279) of those with rectum cancer had an dMMR tumor. Among the patients with MMR determination, 26% (99/384) patients had a T4 dMMR colon cancer; thus, the 10 patients treated with neoadjuvant pembrolizumab comprised about 9% of the patients with a T4 dMMR colon cancer (9/99) and 5% of patients with dMMR rectal cancer (1/19). Therapy with pembrolizumab was feasible and effective. Larger prospective trials are needed to confirm our findings.  相似文献   
4.
Partial differential equations (PDEs) play a dominant role in the mathematical modeling of many complex dynamical processes. Solving these PDEs often requires prohibitively high computational costs, especially when multiple evaluations must be made for different parameters or conditions. After training, neural operators can provide PDEs solutions significantly faster than traditional PDE solvers. In this work, invariance properties and computational complexity of two neural operators are examined for transport PDE of a scalar quantity. Neural operator based on graph kernel network (GKN) operates on graph-structured data to incorporate nonlocal dependencies. Here we propose a modified formulation of GKN to achieve frame invariance. Vector cloud neural network (VCNN) is an alternate neural operator with embedded frame invariance which operates on point cloud data. GKN-based neural operator demonstrates slightly better predictive performance compared to VCNN. However, GKN requires an excessively high computational cost that increases quadratically with the increasing number of discretized objects as compared to a linear increase for VCNN.  相似文献   
5.
6.
7.
8.
Background: Oral submucous fibrosis (OSF) is a chronic debilitating condition characterized by juxta-epithelial fibrosis. The main etiological agent associated with the high-risk precancerous condition is areca nut use. S100A7 is a member of the largest calcium-binding proteins exclusively found in vertebrates and are associated with the regulation of numerous intracellular and extracellular functions. The aim of this study was to investigate the expression of protein S100A7 in salivary samples of individuals with stage I OSF and healthy controls. Methods: This study included 63 participants, 30 of whom had OSF stage I and 33 healthy controls. Nonprobability quota sampling technique was utilized for recruitment of the study participants. A structured baseline questionnaire was used to collect demographic data. Saliva samples were collected by passive droll technique in a sterile container. Salivary levels of S100A7 were quantified by enzyme-linked immunosorbent assay. For the normality of the data Shapiro Wilk test was performed. Student t-test was commuted to evaluate the expression of S100A7 protein expression between both the study groups. Results: The mean salivary S100A7 value for stage I OSF group was 0.334 ng/ml, compared to 0.172 ng/ml for healthy controls. Student t-test reported a statistically significant difference, indicating higher levels of S100A7 in stage I OSF group than in healthy controls (p < 0.001). In the individual group analysis, a significant negative correlation was found between salivary S100A7 and duration of areca nut use (r = –0.45, p = 0.009) and gutka chewing (r = –0.20, p = 0.03), while a significant positive correlation was found between salivary S100A7 and mouth opening (r = 0.03, p = 0.04). Conclusions: Higher levels of S100A7 protein level was seen in stage I OSF group in comparison to the healthy individuals. Results of our study suggest that S100A7 could be used as a surrogate assessment to identify patients at risk of OSF development.  相似文献   
9.
Dengue, a mosquito‐borne viral disease, causes about 100 million cases of infection annually. It is a major public concern, and if left untreated or improperly diagnosed, may cause serious health problems or even death. Historically, dengue has not considered priorities for pharmaceutical companies made the available treatment options. Therefore, medicinal scientists are revealing new insights and enabling novel interventions and approaches to dengue prevention and control. Diterpenes, a class of terpenes have gained much attention due to their diverse biological effects. This review aimed at summarizing available evidences of diterpenes and their derivatives acting against dengue virus and their vectors. For this, an updated search was made in the databases: PubMed and ScienceDirect by using specific keywords. Among the 117 published reports, a total of 30 articles was included in this review. Findings suggest that a number of diterpenes and/or their derivatives act against dengue virus and their two potential vectors namely Aedes aegypti and Ae. albopictus. In conclusion, diterpenes and their derivatives may have the potential alternative therapeutic tools for the management of dengue virus and some associated diseases transmitted by Aedes mosquito.  相似文献   
10.
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