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   12833篇
  免费   809篇
  国内免费   79篇
耳鼻咽喉   106篇
儿科学   246篇
妇产科学   234篇
基础医学   1148篇
口腔科学   92篇
临床医学   850篇
内科学   1705篇
皮肤病学   364篇
神经病学   922篇
特种医学   297篇
外科学   1108篇
综合类   299篇
现状与发展   3篇
预防医学   3822篇
眼科学   67篇
药学   1637篇
中国医学   13篇
肿瘤学   808篇
  2024年   2篇
  2023年   219篇
  2022年   332篇
  2021年   481篇
  2020年   592篇
  2019年   279篇
  2018年   415篇
  2017年   516篇
  2016年   551篇
  2015年   560篇
  2014年   906篇
  2013年   887篇
  2012年   651篇
  2011年   693篇
  2010年   673篇
  2009年   573篇
  2008年   514篇
  2007年   519篇
  2006年   456篇
  2005年   452篇
  2004年   401篇
  2003年   332篇
  2002年   379篇
  2001年   310篇
  2000年   333篇
  1999年   259篇
  1998年   138篇
  1997年   106篇
  1996年   153篇
  1995年   78篇
  1994年   72篇
  1993年   49篇
  1992年   160篇
  1991年   140篇
  1990年   141篇
  1989年   112篇
  1988年   101篇
  1987年   67篇
  1986年   13篇
  1985年   22篇
  1984年   29篇
  1983年   17篇
  1982年   6篇
  1981年   12篇
  1980年   5篇
  1979年   3篇
  1977年   3篇
  1975年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
1.
A 25-year-old, emaciated man without medical treatment was found to have died suddenly at home by his mother. At autopsy, there were no injuries to his body, but significant circulatory insufficiency was observed. Electron microscopy revealed abnormal mitochondria in cells of the cardiac conduction system. The conduction system was filled with mitochondrial size abnormalities and mitochondrial cristae abnormalities. No notable abnormal findings were observed in other organs. Genetic examination of the blood revealed the mitochondrial pathogenetic variant m.3243A>G. Epileptic seizures, diabetic ketoacidosis, and hyperosmolar hyperglycemic state were unlikely to be the cause of sudden death. The cause of death was diagnosed as arrhythmia possibly induced by the failure of the cardiac conduction system due to mitochondrial disease. This is a rare case of sudden death caused by an accumulation of abnormal mitochondria in the cardiac conduction system.  相似文献   
2.
《Clinical therapeutics》2022,44(12):1604-1623
PurposeVoriconazole, an antifungal drug, is metabolized by a cytochrome P450 isozyme. Increased adverse effects are observed in Asians because of the high rate of poor metabolizers. In this therapeutic drug monitoring (TDM) guideline, recommendations were made according to ethnic group.MethodsFive clinical questions were used. For the preparation of the guideline, the performance of TDM in multicenter studies was surveyed (study 1). We also conducted a systematic review and meta-analysis (study 2) to establish recommendations for non-Asians and Asians.FindingsIn study 1, 401 patients were surveyed. A risk of supratherapeutic concentrations was found in Japanese patients who adhered to the recommended dose. Target trough levels were achieved in 87% of patients with dose reductions. Although the trough level measured at the onset of adverse effects (AEs) was significantly associated with hepatotoxicity, no significant correlation was found between the initial trough level and hepatotoxicity, which indicated that hepatotoxicity was successfully prevented by the trough-guided dosing. In study 2, 22 studies (11 Asian locations and 11 non-Asian locations) were included in meta-analysis for the relationship between trough cutoff level (3, 4, 5, 5.5, and 6 µg/mL) and AEs. Significant differences were found for all cutoff levels, with the highest odds ratio for 4.0 µg/mL in Asian locations. In contrast, in non-Asian locations, no more than 1 study was available for any trough cutoff level, except for 5.5 µg/mL, at which level a significant increase in AEs was found. These findings indicate that TDM is strongly recommended to prevent AEs in Asians, and TDM is generally recommended for non-Asians to address subtherapeutic concentrations. TDM on day 3 is recommended to assess pharmacokinetic properties, including loading and maintenance doses. If the patient condition permits, delaying until day 5 is suggested for Asians because of the prolonged t½ in poor metabolizers. A trough level ≥1.0 µg/mL is strongly recommended to improve efficacy. Trough levels ≥2.0 µg/mL are suggested for invasive aspergillosis. To decrease adverse effects, trough levels <4.0 µg/mL are strongly recommended in Asians, whereas trough levels <5.5 µg/mL are generally recommended in non-Asians. Maintenance doses of 4 and 3 mg/kg twice daily are recommended in non-Asians and Asians, respectively.ImplicationsDifferent indications, timings, and target trough levels for TDM and different regimens are suggested for Asians and non-Asians.  相似文献   
3.
4.
5.
6.
Toxicity resulting from off-target effects, beyond acetylcholine esterase inhibition, for the commonly used organophosphate (OP) insecticides chlorpyrifos (CPS) and malathion (MA) was investigated using Saccharomyces cerevisiae and Caenorhabditis elegans model systems. Mitochondrial damage and dysfunction were observed in yeast following exposure to CPS and MA, suggesting this organelle is a major target. In the C. elegans model, the mitochondrial unfolded protein response pathway showed the most robust induction from CPS and MA treatment among stress responses examined. GABAergic neurodegeneration was observed with CPS and MA exposure. Impaired movement observed in C. elegans exposed to CPS and MA may be the result of motor neuron damage. Our analysis suggests that stress from CPS and MA results in mitochondrial dysfunction, with GABAergic neurons sensitized to these effects. These findings may aid in the understanding of toxicity from CPS and MA from high concentration exposure leading to insecticide poisoning.  相似文献   
7.
8.

Background

It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.

Objective

To investigate the association between one-year exposure to PM with an aerodynamic diameter <2.5?μm (PM2.5) and the risk of metabolic syndrome in Korean adults without CVD.

Methods

Exposure to PM2.5 was assessed using a Community Multiscale Air Quality (CMAQ) model. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III. Andersen and Gill model with time-varying covariates, considering recurrent events, was used to investigate the association between one-year average PM2.5 and the risk of incident metabolic syndrome in 119,998 adults from the national health screening cohort provided by Korea National Health Insurance from 2009 to 2013.

Results

Higher risk of metabolic syndrome, waist-based obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia were significantly associated with a 10-μg/m3 increase in PM2.5 [adjusted hazard ratio (HR): 1.070, 1.510, 1.499, 1.468, 1.627 and 1.380, respectively]. In addition, the risk of metabolic syndrome associated with PM2.5 exposure was significant in the consistently obese group (obese at baseline and endpoint).

Conclusion

Exposure to one-year average PM2.5 is associated with an increased risk of metabolic syndrome and its components in adults without CVD. These associations are particularly prominent in the consistently obese group (obese at baseline and endpoint). Our findings indicate that PM2.5 affects the onset of MS and its components which may lead to increase the risk of CVD.  相似文献   
9.
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