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   25266篇
  免费   3354篇
  国内免费   1034篇
耳鼻咽喉   175篇
儿科学   547篇
妇产科学   373篇
基础医学   4006篇
口腔科学   447篇
临床医学   1963篇
内科学   5120篇
皮肤病学   427篇
神经病学   1753篇
特种医学   458篇
外国民族医学   5篇
外科学   2202篇
综合类   3315篇
现状与发展   5篇
一般理论   2篇
预防医学   1250篇
眼科学   319篇
药学   3090篇
  2篇
中国医学   718篇
肿瘤学   3477篇
  2024年   48篇
  2023年   801篇
  2022年   1201篇
  2021年   1694篇
  2020年   1613篇
  2019年   1681篇
  2018年   1432篇
  2017年   1377篇
  2016年   1267篇
  2015年   1579篇
  2014年   1911篇
  2013年   1619篇
  2012年   1508篇
  2011年   1682篇
  2010年   1438篇
  2009年   1110篇
  2008年   1051篇
  2007年   864篇
  2006年   684篇
  2005年   655篇
  2004年   612篇
  2003年   440篇
  2002年   322篇
  2001年   280篇
  2000年   319篇
  1999年   258篇
  1998年   173篇
  1997年   140篇
  1996年   134篇
  1995年   129篇
  1994年   90篇
  1993年   88篇
  1992年   71篇
  1991年   76篇
  1990年   62篇
  1989年   57篇
  1988年   45篇
  1987年   39篇
  1985年   123篇
  1984年   126篇
  1983年   112篇
  1982年   120篇
  1981年   105篇
  1980年   87篇
  1979年   110篇
  1978年   64篇
  1977年   53篇
  1976年   44篇
  1975年   40篇
  1973年   34篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The performance of enzyme linked immunosorbent assays (EAST) for identifying six indoor allergens was evaluated using skin prick test (SPT) as reference tests in 154 children with allergic rhinitis. Sensitivity of EAST ranged from 9% (cat) to 54% (HDM) with specificity of 74%(cockroach) to 100% (cat) with an agreement ranged from 58 to 86%. Cut off values ?> ?0.35 kU/L showed best sensitivity and specificity. Our findings agree with extant literature which suggests that the ability of EAST to determine the precipitating allergen is moderate. Assays for definitively identifying the inhalant allergen are currently not available.  相似文献   
5.
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time.  相似文献   
6.
Blood pressure regulation is impacted by a spinal cord injury (SCI) due to impaired descending sympathetic vascular control. Common blood pressure problems in the SCI population include persistently low blood pressure with bouts of orthostatic hypotension and autonomic dysreflexia, which are more prevalent in individuals with lesions above the sixth thoracic vertebral level; however, they may occur regardless of the neurological level of injury. Although blood pressure disorders adversely impact daily function and quality of life, most individuals with SCI do not acknowledge this association. Few pharmacological options have been rigorously tested for safety and efficacy to manage blood pressure disorders in the SCI population. Furthermore, clinical management of any one blood pressure disorder may adversely impact others, as such treatment is complicated and not often prioritized.  相似文献   
7.
8.
BackgroundIn order to avoid excessive treatment of thyroid nodules in the clinic, it is necessary to find a simple and practical analysis method to comprehensively and accurately reflect benign or malignant thyroid nodules. This study aimed to construct and validate a comprehensive and reliable network-based predictive model using a variety of imaging and laboratory criteria for thyroid nodules to stratify the risk of malignancy prior to surgery.MethodsWe retrospectively analyzed data from patients who underwent surgical treatment for thyroid nodules at the Thyroid and Breast Diagnosis and Treatment Center of Weifang Hospital of Traditional Chinese Medicine between January 2018 and December 2020. Binary logical regression analysis was performed to predict whether nodules were malignant or benign. The developmental dataset included 457 patients (January 2018–December 2020). The validation set included separate data points (n = 225, January 2018–December 2020).ResultsIn this study, criteria that showed significant predictive value for malignant nodules included TI-RADS: 4b (p = 0.065); Bethesda IV, Bethesda V, Bethesda VI (P < 0.0001); BRAFV600E mutation (P < 0.0001); Calcitonin>5 pg/ml (p = 0.0037); and FNA-Tg>30 ng/ml (p = 0.0003). A 10-grade risk scoring system was developed. The risk of malignancy risk ranged from 2.06% to 100% and was positively associated with increasing risk grade. The areas under the receiver-operating characteristic curve of the development and validation sets were 0.972 and 0.946, respectively.ConclusionA simple, comprehensive and reliable web-based predictive model was designed using a variety of imaging and laboratory criteria to stratify thyroid nodules by probability of malignancy.  相似文献   
9.
郑轶  周玉  刘淑玉  何玉 《现代肿瘤医学》2022,(22):4155-4161
目的:探讨细胞骨架调节剂(lncRNA cytoskeleton regulator,CYTOR)是否通过靶向调控miR-503来促进细胞周期蛋白E1(cyclin E1,CCNE1)影响上皮性卵巢癌增殖。方法:实时定量聚合酶链反应(RT-qPCR)检测CYTOR在不同临床分期、病理分级和有无淋巴结转移患者人上皮性卵巢癌组织、癌旁组织和正常组织以及不同卵巢癌细胞中的表达;starBase数据库(网址:http://starbase.sysu.edu.cn/)预测分析CYTOR和miR-503以及miR-503与CCNE1之间的关系,同时荧光素酶实验进行验证;RT-qPCR和免疫荧光分别检测miR-503与CCNE1在人上皮性卵巢癌组织、癌旁组织和正常组织以及不同卵巢癌细胞中的表达;RNA转染技术在A2780中细胞分别沉默CYTOR、过表达miR-503和沉默CCNE1表达,CCK-8检测各组细胞增殖能力变化;RT-qPCR和免疫荧光检测沉默CYTOR后miR-503和CCNE1的表达以及过表达miR-503后CCNE1的表达。结果:CYTOR和CCNE1在上皮性卵巢癌组织中表达增加,同时在临床分期III-IV期、病理分级G_(3)级、淋巴结转移阳性患者肿瘤组织中表达同样显著增加且导致卵巢癌患者术后预后较差;通过数据库分析CYTOR可直接靶向抑制miR-503,而miR-503可直接靶向抑制CCNE1表达,双荧光素酶实验结果与之相同;CYTOR和CCNE1促进上皮性卵巢癌增殖,而miR-503抑制上皮性卵巢癌增殖作用。结论:lncRNA CYTOR通过调控miR-503/CCNE1轴促进上皮性卵巢癌的增殖。  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