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   4886篇
  免费   329篇
  国内免费   131篇
耳鼻咽喉   22篇
儿科学   86篇
妇产科学   45篇
基础医学   969篇
口腔科学   27篇
临床医学   224篇
内科学   899篇
皮肤病学   89篇
神经病学   546篇
特种医学   193篇
外国民族医学   1篇
外科学   273篇
综合类   419篇
预防医学   237篇
眼科学   40篇
药学   828篇
  3篇
中国医学   152篇
肿瘤学   293篇
  2023年   49篇
  2022年   63篇
  2021年   125篇
  2020年   135篇
  2019年   113篇
  2018年   149篇
  2017年   151篇
  2016年   139篇
  2015年   161篇
  2014年   323篇
  2013年   404篇
  2012年   269篇
  2011年   331篇
  2010年   243篇
  2009年   271篇
  2008年   265篇
  2007年   249篇
  2006年   210篇
  2005年   195篇
  2004年   174篇
  2003年   192篇
  2002年   115篇
  2001年   86篇
  2000年   95篇
  1999年   76篇
  1998年   46篇
  1997年   41篇
  1996年   59篇
  1995年   57篇
  1994年   58篇
  1993年   45篇
  1992年   45篇
  1991年   45篇
  1990年   38篇
  1989年   40篇
  1988年   26篇
  1987年   22篇
  1986年   24篇
  1985年   37篇
  1984年   28篇
  1983年   14篇
  1982年   24篇
  1981年   21篇
  1980年   14篇
  1979年   13篇
  1978年   13篇
  1977年   10篇
  1976年   10篇
  1974年   6篇
  1973年   7篇
排序方式: 共有5346条查询结果,搜索用时 265 毫秒
1.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment.  相似文献   
2.
3.
4.
Erythema induratum of Bazin (EIB) is a form of tuberculid resulting from hypersensitivity to tuberculosis antigen. EIB occurs most commonly in middle‐aged women and is not typically seen in children. Here, we present a rare case of EIB, presenting as a chronic nodular panniculitis, in a 10‐year‐old Korean boy.  相似文献   
5.
Frontal fibrosing alopecia (FFA) is a primary patterned cicatricial alopecia with a complicated pathogenesis yet to be fully understood. FFA appears to be increasing in incidence worldwide, especially in the last decade. In order to consider current treatment options, we reviewed current evidence for its pathogenesis comprising immune-mediated, genetic, hormonal and environmental factors. Th1-mediated inflammation with collapse of hair follicle immune privilege and bulge epithelial stem cell destruction, peroxisome proliferator-activated receptor gamma (PPAR-γ) depletion and epithelial–mesenchymal transition are key events leading to permanent hair follicle destruction in FFA. Although the vast majority of cases are sporadic, familial reports of FFA implicate genetic or epigenetic mechanisms in its pathogenesis. The frequent onset of FFA in post-menopausal women, similar patterning and co-existence with female pattern hair loss, together with a reportedly good response to 5α-reductase inhibitors suggest a role for sex steroid hormones. The reported increasing incidence invites speculation for, yet unproven, environmental triggers such as sun exposure and topical allergens. More robust research into this unique entity is required to help understand the complexity of the pathogenesis of FFA in order to find satisfactory therapeutic targets for this often distressing condition.  相似文献   
6.
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis.  相似文献   
7.
BackgroundAlthough colitis has been reported in patients treated with immune checkpoint inhibitors (ICIs), associations between colitis and ICIs had not been thoroughly assessed in real-world studies. Here, we identified and characterized significant colitis-associated with ICIs.MethodsBased on the Food and Drug Administration Adverse Event Reporting System (FAERS) from January 2004 to December 2019, the disproportionality analysis and Bayesian analysis, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN) and the multi-item gamma Poisson shrinker (MGPS) algorithms were adopted to data mining of the suspected adverse events of colitis after ICIs administrating. Clinical characteristics of patients with ICIs-associated colitis and the time to onset of colitis following different ICI regimens were collected.ResultsA total of 3786 reports of colitis adverse events were identified with ICIs. Seven ICI monotherapies were associated with the reporting of colitis. Statistically significant ROR, PRR, information component (IC), and empirical Bayesian geometric mean (EBGM) emerged for all ICI monotherapies and combination therapies. ICIs-associated colitis affected mostly male (53.51%), with a wide mean age range (60.65 to 72 years). Colitis adverse events were commonly reported in patients with melanoma and lung cancer. Adverse outcomes of colitis concerning ICI were mainly outcomes of hospitalization-initiated or prolonged and other serious. Among colitis cases, 17.43% cases of colitis concerning ICI lead to death. The adverse event of colitis occurred earliest in ipilimumab monotherapy with a median time to onset of 64.21 days (IQR: 27–69 days) among all monotherapies.ConclusionsICI may lead to severe and disabling ICIs-associated colitis during therapy. Analysis of FAERS data identified signals for adverse events of colitis with ICI regimens. Practitioners should consider the factors that may increase the likelihood of colitis. The findings support a continued surveillance and risk factor identification studies.  相似文献   
8.
9.
Podocyte apoptosis plays a pivotal role in the pathogenesis of diabetic nephropathy (DN). The main purpose of this study was to investigate the effects of perilipin2 on high glucose (HG)-induced podocyte apoptosis and associated mechanisms. Differentially expressed genes (DEGs) in BTBR ob/ob mice vs. nondiabetic mice kidneys were obtained from GSE106841 dataset and picked out using the ‘limma’ package. The protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) and was visualized by Cytoscape. Perilipin2 was a hub gene using the cytoHubba plug-in from Cytoscape. Gene ontology (GO) analysis revealed that the 126 overlapping DEGs were mainly enriched in ‘oxidation reduction’ [biological process, (BP)], metal ion binding’ [molecular function, (MF)] and ‘extracellular region’ [cellular component, (CC)]. KEGG pathway analysis revealed that perilipin2 was mainly involved in ‘PPAR signaling pathway’. DN inhibited perilipin2 expression and PPARγ expression, as by both in vitro and in vivo studies. In vitro experiments demonstrated that perilipin2 inhibition could not only reduced PPARγ expression in podocytes, it could also promote the apoptosis, and inhibit the viability in HG treated podocytes using western blot, CCK8 and flow cytometry assays. Perilipin2 overexpression reversed the effects of HG on inhibiting podocalyxin, nephrin, precursor (pro)-caspase-3/-9 and PPARγ protein expression and increasing cleaved caspase-3/-9 protein expression. Furthermore, the functions of perilipin2 overexpression reversing HG-induced podocyte apoptosis were inhibited by PPARγ inhibitor. In conclusion, the functions of DN-induced podocyte apoptosis were inhibited by activation of the PPARγ signaling pathway caused by perilipin2 overexpression.  相似文献   
10.
随着人类平均寿命延长,癌症对人类的威胁日益突出,已经成为我国城乡居民的第1位死因。随着病情进展,很多患者除了原发恶性肿瘤外,多数会有其他部位的转移瘤出现,因此选择有效的治疗方法至关重要。体部伽马刀治疗是一种精确的立体定向放疗方法,能够给予肿瘤较高剂量,并较好的保护周围正常组织。大量临床治疗结果显示体部伽马刀治疗肺转移瘤、肝转移瘤和肾上腺转移瘤可获得较高的局控率。本文就体部伽马刀治疗各类转移瘤进行综述。  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