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   61144篇
  免费   6358篇
  国内免费   2362篇
耳鼻咽喉   453篇
儿科学   869篇
妇产科学   3240篇
基础医学   11227篇
口腔科学   2026篇
临床医学   5463篇
内科学   4933篇
皮肤病学   1282篇
神经病学   3578篇
特种医学   1498篇
外国民族医学   43篇
外科学   5338篇
综合类   10211篇
现状与发展   17篇
一般理论   12篇
预防医学   4212篇
眼科学   946篇
药学   5992篇
  41篇
中国医学   2100篇
肿瘤学   6383篇
  2024年   59篇
  2023年   696篇
  2022年   995篇
  2021年   2169篇
  2020年   1924篇
  2019年   1819篇
  2018年   1781篇
  2017年   2157篇
  2016年   2309篇
  2015年   2330篇
  2014年   3840篇
  2013年   4534篇
  2012年   3496篇
  2011年   3883篇
  2010年   3313篇
  2009年   2956篇
  2008年   2848篇
  2007年   3057篇
  2006年   2844篇
  2005年   2467篇
  2004年   2244篇
  2003年   2076篇
  2002年   1704篇
  2001年   1511篇
  2000年   1205篇
  1999年   1071篇
  1998年   1059篇
  1997年   994篇
  1996年   949篇
  1995年   863篇
  1994年   763篇
  1993年   689篇
  1992年   621篇
  1991年   551篇
  1990年   427篇
  1989年   427篇
  1988年   376篇
  1987年   283篇
  1986年   270篇
  1985年   439篇
  1984年   385篇
  1983年   266篇
  1982年   307篇
  1981年   223篇
  1980年   185篇
  1979年   117篇
  1978年   119篇
  1977年   72篇
  1976年   72篇
  1975年   36篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
2.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
3.
4.
陈红亮 《中医学报》2016,(6):910-912
目的:观察理筋通督手法治疗颈性眩晕的临床疗效。方法:将120例颈性眩晕患者随机分成3组,理筋通督组、传统手法组及安慰剂组。理筋通督组采用理筋通督手法;传统手法组采用传统手法;安慰剂组口服维生素C。结果:理筋通督手法可显著减缓患者基底动脉舒张期最低血流速度(P0.05)。理筋通督组有效率为93.67%,传统手法组有效率为67.5%,安慰剂组有效率为17.5%,3组比较差异有统计学意义(P0.05),理筋通督组明显优于其他两组。结论:理筋通督手法治疗颈性眩晕临床疗效显著。  相似文献   
5.
目的:了解2011-2017年四川省三州地区卫生人力资源配置现状,为三州地区卫生人力资源的合理配置提供参考。方法:利用千人卫生人力资源拥有量指标、基尼系数和卫生人力资源密度指数(HRDI)分析卫生人力资源配置现状及其公平性。结果:三州地区千人卫生人力资源拥有量呈增长趋势;基尼系数大多超过0.4,仅护士按人口分布的基尼系数较小;卫生人力资源密度指数较小,需要量、缺乏量及缺乏比例均较大。结论:三州地区卫生人力得到一定程度改善;但配置公平性较差,尤其按地理、经济分布很不均衡;医护人员短缺,需要重点投入。  相似文献   
6.
7.
Background: Self sampled HPV testing is a cervical cancer screening method . However, cytology in self-sampled specimen cannot be used as a triage test.  Therefore, other methods for triage should be considered. CyclinA1 (CCNA1) promoter methylation has strong association with cervical precancerous and cancerous lesion. The objective of this study was to compare the diagnostic value of CCNA1 and self-sampled specimen for detecting high-grade cervical intraepithelial lesions or worse (CIN2+). Materials and Methods: A cross sectional study was conducted. Women with abnormal cytology or positive for high risk HPV (hrHPV) indicated for colposcopic examination were enrolled.  Self-collected sampling for hrHPV DNA (SS-HPV) and CCNA1 were performed. hrHPV DNA testing was done by Cobas 4800 method. CCNA1 promoter methylation was detected by CCNA1 duplex methylation specific PCR. Histopathologic result as CIN2+ obtaining from colposcopic directed biopsy or excisional procedure  was considered as positive a gold standard. The results of hrHPV and CCNA1 were reported as positive or negative. Sensitivity specificity, positive predictive value, and negative predictive value of SS-HPV and CCNA1 were calculated by comparing the results with the gold standard. Results: Two hundreds and eighty women were recruited. High-grade cervical lesions and cervical cancer (CIN2+) were diagnosed in 21.8% (61 cases) of the patients. The most common type of hrHPV was non 16, 18 subtype, followed by HPV16 and 18. CCNA1 was positive in 13 patients out of whom, twelve were CIN2+. Sensitivity of CCNA1 was 19.7 % and its  specificity and accuracy were 99.5% and 82.14%, respectively.  The sensitivity of SS-HPV was 70.5%, and its  specificity and accuracy were 39.2% and 43.3%, respectively. Conclusion:  Due to high specificity and positive predictive value of CCNA1, it can be used as alarming sign of having high-grade cervical intraepithelial lesions, especially in patient who has positive hrHPV DNA test based on self-collected sampling.  相似文献   
8.
Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicatedin advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-EastIndia and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examinationfrom September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational(epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved,standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters.Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantlyhigher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patientswith well differentiated histology and was more common in patients with stage II and III diseases, but neither of theassociations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours(56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patientswith locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlatedsignificantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expressionis recommended to provide a therapeutic advantage in Indian patients.  相似文献   
9.
宫颈癌对妇女健康构成严重威胁,人乳头瘤病毒感染与宫颈病变及宫颈癌的发生密切相关。关于宫颈癌发生发展的机制仍在研究中。近年研究发现一种多功能核蛋白,即死亡结构域相关蛋白(death domain associated protein,Daxx),其与细胞内蛋白或病毒蛋白相互作用,参与调节细胞凋亡、转录调控、抗病毒等细胞活动,在不同途径中发挥不同的生理或病理作用。通过对Daxx功能及其作用机制的研究有助于进一步阐明宫颈癌发生发展的机制,有助于发现新的预防和治疗方法。综述Daxx的一般特性和研究现况及其在宫颈病变的研究进展。  相似文献   
10.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  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