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   728篇
  免费   57篇
  国内免费   18篇
耳鼻咽喉   13篇
儿科学   21篇
妇产科学   5篇
基础医学   37篇
口腔科学   19篇
临床医学   105篇
内科学   72篇
皮肤病学   11篇
神经病学   68篇
特种医学   21篇
外科学   54篇
综合类   130篇
预防医学   111篇
眼科学   4篇
药学   73篇
中国医学   38篇
肿瘤学   21篇
  2024年   2篇
  2023年   6篇
  2022年   7篇
  2021年   11篇
  2020年   11篇
  2019年   13篇
  2018年   12篇
  2017年   15篇
  2016年   13篇
  2015年   29篇
  2014年   51篇
  2013年   68篇
  2012年   65篇
  2011年   84篇
  2010年   42篇
  2009年   49篇
  2008年   66篇
  2007年   79篇
  2006年   41篇
  2005年   29篇
  2004年   27篇
  2003年   10篇
  2002年   13篇
  2001年   4篇
  2000年   18篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1993年   4篇
  1992年   2篇
  1991年   1篇
  1990年   5篇
  1989年   1篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1981年   4篇
  1976年   1篇
  1975年   4篇
  1973年   1篇
  1971年   1篇
  1964年   1篇
排序方式: 共有803条查询结果,搜索用时 15 毫秒
791.
792.
Carcinomaofthecervixisthesecondleading causeofdeathamongwomenworldwide.Each year,anestimated500000casesarenewlydiag nosed[1].Manystudiesshowedinfectionofhu manpapillomavirus(HPV)wasoneofthemost importantetiologicfactorsforcervicalcarcinoma[24].Morethan95%ofallcervicalcarcinomas havebeenfoundtobeassociatedwithHPV(ma inlytypes16and18)[5].Thestudiesinmolec ularoncologyrecentlyshowedthatitresultedin occurrenceanddevelopmentofcervicalcarcinomasthatcarcinogenicfactorsmadeproto oncogene activatean…  相似文献   
793.
With increased frequency, clinical geneticists are asked for genetic advice on the heredity of dementia in families. Alzheimer's disease is in most cases a complex disease, but may be autosomal dominant inherited. Mutations in the PSEN1 gene are the most common genetic cause of early onset Alzheimer's disease, whereas APP and PSEN2 gene mutations are less frequent. Familial frontotemporal dementia may be associated with a mutation in the MAPT or GRN gene, or with a repeat expansion in the C9orf72 gene. All these genes show autosomal dominant inheritance with a high penetrance. Although Alzheimer's disease and frontotemporal dementia are clinically distinguishable entities, phenotypical overlap may occur. Rarely, dementia is caused by mutations in other autosomal dominant genes or by genetic defects with autosomal recessive, X-linked dominant or mitochondrial inheritance. The inherited forms of frontotemporal dementia and Alzheimer's disease show a large phenotypic variability also within families, resulting in many remaining uncertainties for mutation carriers. Therefore, genetic counseling before performing genetic testing is essential in both symptomatic individuals and healthy at risk relatives. This review provides an overview of the genetic causes of dementia and discusses all aspects relevant for genetic counseling and testing. Furthermore, based on current knowledge, we provide algorithms for genetic testing in patients with early onset Alzheimer's disease or frontotemporal dementia. ? 2012 Wiley Periodicals, Inc.  相似文献   
794.
目的 通过对甲状腺手术中最常发生喉返神经损伤的Berry韧带区的解剖,为甲状腺手术中避免喉返神经的损伤提供解剖学基础.方法 对25例(男性15例,女性10例)固定尸体标本进行大体解剖,记录Berry韧带的起止点及其与喉返神经的位置关系.将甲状腺分别向外侧、前内侧提拉,从甲状腺的内、外侧测量喉返神经距Berry韧带甲状腺...  相似文献   
795.
目的:检测口腔鳞癌组织(OSCC)中NBS1的表达水平,探讨其与OSCC病理分化级别的相关性以及在肿瘤发生发展中的作用。方法:①采用免疫组化(SP法)检测NBS1蛋白在30例口腔鳞癌组织、9例癌旁组织中的表达。②应用RT-PCR技术检测组织中NBS1的mRNA表达水平。结果:在OSCC与癌旁正常组织中,NBS1 mRNA和蛋白表达差异显著,在口腔癌组织中均表达较高,并随着病理级别增高而增高(P<0.05)。结论:NBS1在不同病理分化程度OSCC中表达水平的差别与多种因素密切相关,与肿瘤的恶性生物学行为有关,其表达水平可成为判断口腔鳞癌侵袭转移和预后的指标之一。  相似文献   
796.

Background  

Although attention to human rights in Indonesia has been improving over the past decade, the human rights situation of persons with mental disorders is still far from satisfactory. The purpose of this paper is to examine the legal framework for protection of human rights of persons with mental disorder and the extent to which Indonesia's international obligations concerning the right to health are being met.  相似文献   
797.

Objective

To evaluate whether magnetic resonance imaging (MRI) of the wrists and finger joints and an analysis of serologic autoantibodies are clinically meaningful for the subsequent development of rheumatoid arthritis (RA) in patients with undifferentiated arthritis (UA).

Methods

A total of 129 patients with UA, a disease status formally confirmed by a rheumatologist over a period of at least 1 year, were included. Gadolinium‐diethylenetriamine–enhanced MRI of both wrists and finger joints and serologic variables were examined upon admission to our Early Arthritis Clinic at Nagasaki University. After a prospective followup of 1 year, a predictive value for the development of RA was determined for each patient.

Results

The subjects were evaluated for their positive or negative status with respect to 3 objective measures at study entry: anti–cyclic citrullinated peptide (anti‐CCP) antibodies and/or IgM‐rheumatoid factor, MRI‐proven symmetric synovitis, and MRI‐proven bone edema and/or bone erosion. The patients who were positive for at least 2 of these measures progressed to RA at 1 year with a 79.7% positive predictive value (PPV), 63.0% negative predictive value, 75.9% specificity, 68.0% sensitivity, and 71.3% accuracy. Furthermore, in 22 UA patients positive for both anti‐CCP antibodies and MRI‐proven bone edema who were considered to have progressed to RA at 1 year, the PPV was increased to 100%. A close correlation was found between the present rule and that established in the Leiden Early Arthritis Cohort.

Conclusion

MRI‐proven early joint damage in conjunction with serologic autoantibodies is efficient in predicting progression from UA to RA. This method can be used to identify patients who would benefit from early treatment with disease‐modifying antirheumatic drugs.  相似文献   
798.
This study examines whether the expression of cyclooxgenase‐2 (COX‐2) in urothelial carcinoma (UC) is associated with macrophage infiltration, hypoxia‐inducible factor‐1α (HIF‐1α) expression and angiogenesis. We investigated the expression of COX‐2 associated with HIF‐1α and performed double immunohistochemical analysis of 216 UCs for COX‐2 expression and the correlation with tumor‐associated‐macrophage (TAM) density and microvessel density (MVD) in situ. A high expression of COX‐2 was positively correlated with tumor invasiveness, histologic grade and HIF‐1α expression in UC (p<0.0001, p=0.003, p<0.0001, respectively). Quantification of double staining of COX‐2/CD34 and COX‐2/CD68 showed that a higher MVD and TAM density was found in COX‐2 high‐expression than in COX‐2 low‐expression tumor fields (p<0.0001). Adjacent to the principal of COX‐2 expression areas, MVD value and TAM density were significantly increased in HIF‐1α high‐expression specimens compared with HIF‐1α low‐expression ones (p<0.0001). Interestingly, our data revealed that high COX‐2 expression (p=0.002), high HIF‐1α expression (p<0.0001) and TAM density (p<0.0001) were all associated with high MVD value. Our results suggest that COX‐2 may produce a cooperative effect in promoting tumor progression and may be involved in the process of angiogenesis through increasing TAM infiltration or HIF‐1α regulation by hypoxia.  相似文献   
799.
血管平滑肌脂肪瘤(Angiomyolipoma,AML)是一种少见的主要好发于肾脏的间叶肿瘤.肾外AML偶见于肝脏、腹膜后、纵隔等处[1].发生于小肠系膜的AML午见.现将我院经于术病理证实的1例小肠系膜AML报告如下.病例男,20岁,发现腹部肿块3,中余入院.查体:神清、精神可,心肺(一).腹平软,左侧腹部以脐为中心可触及一约15cm人小的肿块,质韧界清,活动度大,无压痛,移动性浊音(一),神经系统(一).T 36.7 ℃,P 80次/min,R 18次/min,血压120/85mmHg.血尿常规与肝功能生化检查末见异常.  相似文献   
800.
OBJECTIVE: Synchronization likelihood analysis of resting state EEG has shown that cognitive dysfunction in Alzheimer's disease (AD) and its precursor mild cognitive impairment (MCI) are associated with a loss of functional connectivity in high (upper alpha and beta) frequency bands. Working memory tasks are known to change functional connectivity, but it is unknown whether this increases the differences between AD, MCI and healthy controls. Our objective was to investigate the behavior of synchronization likelihood of multichannel EEG in AD, MCI and cognitively healthy controls, both at rest and during a working memory task. METHODS: EEGs (200 Hz sample frequency, 21 channels, average reference) were recorded at rest as well as during a visual working memory task in 14 patients with AD according to the NINCDS-ADRDA criteria (mean age 76.4; SD 13.6), 11 patients with MCI according to the criteria of Petersen (mean age 78.4; SD 6.4) and 14 with subjective memory complaints but no demonstrable memory disturbance (mean age 61.6; SD 26.6). The synchronization likelihood was computed over 19 channels, comparing each channel with all the other channels for the 0.5-4, 4-8, 8-10, 10-12, 12-30, 30-50 Hz frequency bands. RESULTS: The synchronization likelihood was significantly decreased in the upper alpha (10-12) and beta (12-30) bands in AD compared to persons with subjective memory complaints. The working memory task scores strongly correlated with Mini-Mental State Examination scores. During the working memory task the synchronization likelihood was significantly higher in MCI compared to the control subjects in the lower alpha band (8-10 Hz). CONCLUSIONS: Decrease of beta band synchronization occurs in mild AD, both in a resting condition and during a working memory task. SIGNIFICANCE: Decrease of beta band synchronization in mild AD is a robust finding. The present study confirms our findings in a different cohort of patients, using alternative frequency bands. The diagnostic value of the synchronization likelihood in AD and MCI needs to be further established.  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