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   184726篇
  免费   17515篇
  国内免费   11927篇
耳鼻咽喉   1652篇
儿科学   1922篇
妇产科学   2453篇
基础医学   22128篇
口腔科学   3323篇
临床医学   24317篇
内科学   26897篇
皮肤病学   2236篇
神经病学   9626篇
特种医学   6563篇
外国民族医学   98篇
外科学   18776篇
综合类   30119篇
现状与发展   39篇
一般理论   23篇
预防医学   12395篇
眼科学   4774篇
药学   19955篇
  195篇
中国医学   11173篇
肿瘤学   15504篇
  2024年   748篇
  2023年   3025篇
  2022年   7908篇
  2021年   9944篇
  2020年   7490篇
  2019年   6410篇
  2018年   6718篇
  2017年   6172篇
  2016年   5749篇
  2015年   8825篇
  2014年   10714篇
  2013年   9889篇
  2012年   14445篇
  2011年   15568篇
  2010年   9930篇
  2009年   7650篇
  2008年   10184篇
  2007年   9625篇
  2006年   9239篇
  2005年   8943篇
  2004年   5755篇
  2003年   5221篇
  2002年   4344篇
  2001年   3661篇
  2000年   3844篇
  1999年   3919篇
  1998年   2312篇
  1997年   2370篇
  1996年   1805篇
  1995年   1761篇
  1994年   1535篇
  1993年   924篇
  1992年   1288篇
  1991年   1120篇
  1990年   901篇
  1989年   850篇
  1988年   766篇
  1987年   626篇
  1986年   462篇
  1985年   398篇
  1984年   190篇
  1983年   163篇
  1982年   93篇
  1981年   124篇
  1980年   79篇
  1979年   109篇
  1978年   52篇
  1977年   51篇
  1976年   42篇
  1974年   44篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
942.
943.
944.
A better understanding of tumor metastasis is urgently required for the treatment and prognosis of hepatocarcinoma patients. Current work contributes a novel ceRNA feedback regulation pathway composed of epiregulin (EREG), microRNA-330-3p (miR-330-3p) and long non-coding RNA 021545 (lncRNA021545) in regulating hepatocarcinoma malignancy via epithelial-mesenchymal transition (EMT) process. Closely correlated, the deficiencies of EREG and lncRNA021545 and the overexpression of miR-330-3p were involved in the clinical progression of hepatocarcinoma. In vitro results showed that 1) lncRNA021545 downregulation promoted, 2) miR-330-3p dysexpression positively correlated, and 3) EREG dysexpression reversely correlated with the migratory and invasive properties of hepatocarcinoma HCCLM3 and Huh7 cell lines. By directly binding to EREG and lncRNA021545, miR-330-3p expression change reversely correlated with their expressions in HCCLM3 and Huh7 cells, which was also confirmed in primary tumors from HCCLM3-xenograft mice in responding to miR-330-3p change. LncRNA021545 and EREG positively regulated each other, and lncRNA021545 negatively regulated miR-330-3p, while, EREG dysregulation unchanged miR-330-3p expression in hepatocarcinoma cells. Furthermore, systemic in vitro cellular characterizations showed that the malfunctions of the three molecules mediated the invasiveness of hepatocarcinoma cells via EMT process through affecting the expressions of E-cadherin, N-cadherin, vimentin, snail and slug, which was further confirmed by in vivo miR-330-3p promotion on the tumorigenicity and metastasis of HCCLM3 bearing nude mice and by in vitro miR-330-3p promotion on the migration and invasion of hepatocarcinoma cells to be antagonized by EREG overexpression through acting on EMT process. Our work indicates, that by forming a circuit signaling feedback pathway, the homeostatic expressions of lncRNA021545, miR-330-3p and EREG are important in liver health. Its collapse resulted from the downregulations of lncRNA021545 and EREG together with miR-330-3p overexpression promote hepatocarcinoma progression by enhancing the invasiveness of tumor cells through EMT activation. These discoveries suggest that miR-330-3p/lncRNA021545/EREG axis plays a critical role in hepatocarcinoma progression and as a candidate for its treatment.  相似文献   
945.
Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) is a high-risk disease subtype with a dismal prognosis. Inhibiting BCR-ABL kinase alone is insufficient to eradicate Ph+ALL clones, and alternative BCR-ABL-dependent and -independent pathways need to be targeted as an effective strategy. Our study revealed that the combination of dasatinib and interferon-α showed synergistic activity against Ph+ALL, inducing mitochondrial dysfunction and causing necrosis-like cell lysis. Mechanistic studies showed that the induced cell death was caspase-3-independent. Canonical necroptosis signals, such as RIP1 and MLKL, were not activated; instead, the pyroptosis executor Gasdermin D was upregulated expression and activated. The expression levels of extracellular ATP and IL-1β were also upregulated, both of which are markers of pyroptotic cell death. In a murine Ph+ALL model, the dual drug treatment prolonged the survival of tumor-bearing mice. More importantly, we incorporated the dual drugs to maintenance therapy in 39 patients who were unfit for allogeneic stem cell transplantation (allo-HSCT). The median follow-up was 28.5 months, the 4-year disease-free survival and overall survival rates were 52.2% and 65.2%, respectively. Our data suggest that the combination of dasatinib and interferon-α has potential synergistic activity against Ph+ALL and shows promise as a maintenance therapy for Ph+ALL patients who are unfit for allo-HSCT.  相似文献   
946.
目的 探讨瞬时弹性记录仪(FibroScan)检测肝脏受控衰减参数(CAP)诊断非酒精性脂肪性肝炎(NASH)的效能.方法 2016年1月~2020年1月我院收治的NASH患者142例和同期健康体检者130例,使用FibroScan检测肝脏CAP值.采用受试者工作特征曲线(ROC)并计算曲线下面积(AUC)评价CAP值...  相似文献   
947.
BACKGROUNDEpidemiologic studies have explored the association between a single cardiovascular risk factor (CVRF) and resting heart rate (RHR), but the research on the relation of multiple risk factors with RHR remains scarce. This study aimed to explore the associations between CVRFs clustering and the risk of elevated RHR.METHODSIn this cross-sectional study, adults aged 35–75 years from 31 provinces were recruited by the China PEACE Million Persons Projects from September 2015 to August 2020. We focused on seven risk factors: hypertension, diabetes mellitus, dyslipidemia, obesity, smoking, alcohol use, and low physical activity. Multivariate logistic regression was used to calculate odds ratios (OR) for elevated RHR (> 80 beats/min).RESULTSAmong 1,045,405 participants, the mean age was 55.67 ± 9.86 years, and 60.4% of participants were women. The OR (95% CI) for elevated RHR for the groups with 1, 2, 3, 4 and ≥ 5 risk factor were 1.11 (1.08–1.13), 1.36 (1.33–1.39), 1.68 (1.64–1.72), 2.01 (1.96–2.07) and 2.58 (2.50–2.67), respectively (Ptrend < 0.001). The association between the CVRFs clustering number and elevated RHR was much more pronounced in young males than in other age-sex subgroups. Clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR than those comprising more behavioral risk factors. CONCLUSIONSThere was a significant positive association between the CVRFs clustering number and the risk of elevated RHR, particularly in young males. Compared clusters comprising more behavioral risk factors, clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR. RHR may serve as an indicator of the cumulative effect of multiple risk factors.

Over the past several years, the rapid development of smart wrist-worn devices has resulted in a convenient approach to monitoring resting heart rate (RHR) in daily life. RHR is becoming a promising indicator of cardiovascular health. Observational studies have shown that elevated RHR is associated with increased all-cause and cardiovascular mortality in populations with or without cardiovascular disease (CVD).[1,2] Elevated RHR has also been found to be associated with cardiovascular risk factors (CVRFs), such as hypertension, diabetes mellitus, dyslipidemia, low physical activity and smoking, indicating its potential to reflect total cardiac risk.[37] There is abundant epidemiologic evidence supporting the association between a single CVRF and RHR, but studies exploring associations between multiple CVRFs and RHR are limited. CVRFs tend to cluster within individuals, and several weak risk factors combined may result in a much higher risk than that due to a single strong risk factor. According to a cross-sectional survey in China, more than 45% of Chinese adults have two or more coexisting CVRFs.[8] Thus, it is important to consider the situation of multiple CVRFs clustering. However, very few studies have analyzed the association between CVRFs clustering and RHR, and several aspects remain unknown. Firstly, prior studies mainly focused on the relation between metabolic risk factors and RHR.[911] Behavioral risk factors such as smoking, physical activity and alcohol use have rarely been considered, even though these risk factors also have a significant effect on heart rate.[3,5,7] Secondly, most studies merely dealt with the relation of CVRFs clustering number with RHR, while regarding each number of risk factors, different combinations of risk factors have not yet been considered before.[9,12] It is important to consider different CVRF clustering patterns since some risk factors combined may lead to a higher risk of elevated RHR than others, even if the number of CVRFs is the same. Thirdly, prior studies did not assess associations stratified by sex and age. It has been well documented that RHR levels differ by sex and age. The RHR in women was on average 2–7 beats/min higher than that in men, and there was a decrease in the RHR with age.[13,14] As such, whether the associations of CVRFs clustering with RHR varied between sex and age remains unclear. Taking advantage of the large sample size in our study, we are able to include a wider range of CVRFs (metabolic and behavioral risk factors), comprehensively evaluate the association between these CVRFs clustering and RHR, and further explore sex and age differences. This finding may inform us whether RHR can be used as a simple and efficient metric for the identification of high-risk individuals who require more intensive risk factor evaluation and earlier cardiovascular health monitoring in resource-constrained countries with substantial CVD burdens, such as China. To bridge this knowledge gap, we used data from the China PEACE Million Persons Projects, a nationwide screening project, to explore (1) the association between the number of CVRFs clustering and elevated RHR in the overall population and populations stratified by age and sex; and (2) the associations between different CVRFs clusters and the risk of elevated RHR in the overall population and populations stratified by sex.  相似文献   
948.
Aims/IntroductionOverweight and obesity in adults are strongly associated with an increased risk of prediabetes, and this study set out to gain a better understanding of the optimal body mass index (BMI) range for assessing the risk of prediabetes in the Chinese population.Materials and MethodsThe cohort study included 100,309 Chinese adults who underwent health screening. Participants were divided into six groups based on the cut‐off point for BMI recommended by the World Health Organization (underweight: <18.5 kg/m2, normal‐weight: 18.5–24.9 kg/m2, pre‐obese: 25.0–29.9 kg/m2, obese class I: 30.0–34.9 kg/m2, obese class II: 35.0–39.9 kg/m2, and obese class III ≥40 kg/m2). The association of BMI with prediabetes and the shape of the correlation were modeled using multivariate Cox regression and restricted cubic spline regression, respectively.ResultsIn the multivariate Cox regression model, with normal weight as the control group, underweight people had a lower risk of developing prediabetes, whereas obese and pre‐obese people had a higher risk of prediabetes. Additionally, in the restricted cubic spline model, we found that the association of BMI with prediabetes follows a positive dose–response relationship, but does not conform to the pattern of obesity paradox. Among the general population in China, a BMI of 23.03 kg/m2 might be a potential intervention threshold for prediabetes.ConclusionsThe national cohort study found that the association of BMI with prediabetes follows a positive dose–response relationship, rather than a pattern of obesity paradox. For Chinese people with normal weight, more attention should be paid to glucose metabolism when BMI exceeds 23.03 kg/m2.  相似文献   
949.
目的 探讨护士工作繁荣对教练型领导与职业成长关系的中介效应。方法 采用多阶段分层抽样法,选择河南省7所三级甲等医院的447名护士为研究对象,使用护士职业成长量表、教练型领导感知评价量表(护士他评版)和工作繁荣量表进行调查。结果 护士评估的教练型领导评分为69.61±19.17,工作繁荣评分为49.93±10.12,职业成长评分为49.00±10.07,三者之间互为正相关(均P<0.05)。分层回归分析结果显示,在控制一般资料变量后,教练型领导及工作繁荣能解释职业成长总变异的38.2%。工作繁荣在教练型领导与职业成长之间起中介作用,中介效应占总效应的52.560%。结论 教练型领导有助于提升临床护士工作繁荣水平,进而促进其职业成长,提示护理管理者施展教练型领导以挖掘护士职业发展潜力。  相似文献   
950.
A 63-year-old man with an 8-year history of proteinuria was diagnosed with nephrotic syndrome, and a renal biopsy was performed. Light and electron microscopic analyses showed classic features of idiopathic membranous nephropathy (IMN). However, immunofluorescence tests revealed solitary polyclonal granular IgA deposition along the glomerular capillary walls, rather than IgG, which is often dominant in IMN. The combined use of corticosteroids and calcineurin inhibitor was noticeably effective in reducing proteinuria and improving edema in the current case. Two additional rare cases of IMN with solitary IgA deposition were reviewed, and long-term surveillance is still warranted to characterize its clinicopathological features and outcome.  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