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   298538篇
  免费   24240篇
  国内免费   9254篇
耳鼻咽喉   2466篇
儿科学   9363篇
妇产科学   2138篇
基础医学   25111篇
口腔科学   4961篇
临床医学   33089篇
内科学   74632篇
皮肤病学   3595篇
神经病学   28038篇
特种医学   8882篇
外国民族医学   300篇
外科学   22597篇
综合类   45957篇
现状与发展   42篇
一般理论   13篇
预防医学   22211篇
眼科学   2842篇
药学   23174篇
  228篇
中国医学   15828篇
肿瘤学   6565篇
  2024年   310篇
  2023年   5454篇
  2022年   7238篇
  2021年   13901篇
  2020年   13866篇
  2019年   10972篇
  2018年   10824篇
  2017年   10913篇
  2016年   11372篇
  2015年   11061篇
  2014年   23439篇
  2013年   24491篇
  2012年   18681篇
  2011年   19737篇
  2010年   17419篇
  2009年   16460篇
  2008年   14608篇
  2007年   13517篇
  2006年   11951篇
  2005年   9989篇
  2004年   8491篇
  2003年   7349篇
  2002年   6224篇
  2001年   5429篇
  2000年   4506篇
  1999年   3848篇
  1998年   3532篇
  1997年   2829篇
  1996年   2546篇
  1995年   2637篇
  1994年   2415篇
  1993年   1988篇
  1992年   1903篇
  1991年   1643篇
  1990年   1333篇
  1989年   1147篇
  1988年   1060篇
  1987年   950篇
  1986年   834篇
  1985年   1023篇
  1984年   840篇
  1983年   511篇
  1982年   600篇
  1981年   529篇
  1980年   391篇
  1979年   322篇
  1978年   246篇
  1977年   218篇
  1976年   186篇
  1975年   73篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
《Saudi Pharmaceutical Journal》2022,30(11):1572-1588
Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of a metabolic syndrome caused by excessive accumulation of fat in the liver. Orthosiphon stamineus also known as Orthosiphon aristatus is a medicinal plant with possible potential beneficial effects on various metabolic disorders. This study aims to investigate the in vitro inhibitory effects of O. stamineus on hepatic fat accumulation and to further use the computational systems pharmacology approach to identify the pharmacokinetic properties of the bioactive compounds of O. stamineus and to predict their molecular mechanisms against NAFLD. Methods: The effects of an ethanolic extract of O. stamineus leaves on cytotoxicity, fat accumulation and antioxidant activity were assessed using HepG2 cells. The bioactive compounds of O. stamineus were identified using LC/MS and two bioinformatics databases, namely the Traditional Chinese Medicine Integrated Database (TCMID) and the Bioinformatics Analysis Tool for the Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM). Pathway enrichment analysis was performed on the predicted targets of the bioactive compounds to provide a systematic overview of the molecular mechanism of action, while molecular docking was used to validate the predicted targets. Results: A total of 27 bioactive compounds corresponding to 50 potential NAFLD-related targets were identified. O. stamineus exerts its anti-NAFLD effects by modulating a variety of cellular processes, including oxidative stress, mitochondrial β-oxidation, inflammatory signalling pathways, insulin signalling, and fatty acid homeostasis pathways. O. stamineus is significantly targeting many oxidative stress regulators, including JNK, mammalian target of rapamycin (mTOR), NFKB1, PPAR, and AKT1. Molecular docking analysis confirmed the expected high affinity for the potential targets, while the in vitro assay indicates the ability of O. stamineus to inhibit hepatic fat accumulation. Conclusion: Using the computational systems pharmacology approach, the potentially beneficial effect of O. stamineus in NAFLD was indicated through the combination of multiple compounds, multiple targets, and multicellular components.  相似文献   
3.
IntroductionThere is no consensus on the most appropriate treatment for chronic active antibody-mediated rejection (cAMR). Recent studies suggest that treatment with tocilizumab (TCZ) may stabilize graft function, decrease the intensity of donor-specific HLA antibodies (DSAs) and reduce inflammation of microcirculation.Patients and methodsObservational study with renal allograft recipients diagnosed with cAMR (n = 5) who had not submitted a response to traditional treatment based on the combination of plasma replacements, immunoglobulins, and rituximab. Patients were told to be treated with TCZ as compassionate use in six doses per month (8 mg/kg/month). Renal function, proteinuria, and the intensity of DSAs were monitored during follow-up.ResultsFive patients, average age 60 ± 13 years, three male and two retrasplants (cPRA average 55%) with preformed DSAs. Treatment with TCZ was initiated within 47 ± 52 days of biopsy. In two cases treatment was discontinued after the first dose, by severe bicitopenia with cytomegalovirus viremia and by graft failure, respectively. In the three patients who completed treatment, no stability of renal function (serum creatinine from 1.73 ± 0.70 to 2.04 ± 0.52 mg/dL, e-FGR 4 6 ± 15 to 36 ± 16 mL/min), showed increased proteinuria (3.2 ± 4.0 to 6.9 ± 11.0 g/g) and the intensity of DSAs maintain stable. No changes were observed in the degree of inflammation of microcirculation (g + pt 4.2 ± 0.8 vs. 4.3 ± 1.0) or in the degree of transplant glomerulopathy (cg 1.2 ± 0.4 vs. 1.8 ± 1.0).ConclusionsTCZ therapy does not appear to be effective in modifying the natural history of chronic active antibody-mediated rejection, does not improve the degree of inflammation of microcirculation and does not reduces the intensity of DSAs.  相似文献   
4.
5.
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   
6.
7.
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children.  相似文献   
8.
黄晓云  陈玲 《现代肿瘤医学》2022,(21):3944-3947
目的:探讨初诊急性白血病患者化疗期间应用伏立康唑进行预防侵袭性真菌病(IFD)的临床疗效及安全性。方法:回顾性分析2016年02月至2018年03月期间我院血液科收治的初诊急性白血病行化疗的患者166例,按照是否使用抗真菌药进行预防性治疗分为观察组(应用伏立康唑进行预防治疗,n=103)和对照组(未应用抗真菌药物,n=63),比较两组患者IFD发生率差异,并分析抗真菌药物应用的不良反应。结果:观察组IFD发生率为10.7%,对照组为33.3%,两组患者的IFD发生率有明显差异(P<0.05);所有应用伏立康唑进行预防治疗的患者均未出现严重的不良反应。结论:伏立康唑可以有效减低急性白血病患者化疗期间IFD发生率,并且有着较好的安全性,值得在临床推广应用。  相似文献   
9.
BackgroundWe aimed to describe the effectiveness and safety of inhaled antibiotics in chronic obstructive pulmonary disease (COPD) patients, as well as the patient profile in which they are usually prescribed and the patient groups that can most benefit from this treatment.MethodsMulticentre retrospective observational cohort study in COPD patients who had received ≥1 dose of inhaled antibiotics in the last 5 years. Clinical data from the two years prior to and subsequent to the start of the treatment were compared. Primary outcome: COPD exacerbations. Secondary outcomes: side effects, symptomatology (sputum purulence, dyspnoea), microbiological profile and pathogen eradication.ResultsOf 693 COPD patients analyzed (aged 74.1; 86.3% men; mean FEV1 = 43.7%), 71.7% had bronchiectasis and 46.6% presented chronic bronchial infection (CBI) by Pseudomonas aeruginosa (PA). After 1 year of treatment with inhaled antibiotics, there was a significant decrease in the number of exacerbations (?33.3%; P < .001), hospital admissions (?33.3%; P < .001) and hospitalization days (?26.2%; P = .003). We found no difference in effectiveness between patients with or without associated bronchiectasis. Positive patient outcomes were more pronounced in PA-eradicated patients. We found a significant reduction in daily expectoration (?33.1%; P = .024), mucopurulent/purulent sputum (?53.9%; P < .001), isolation of any potentially pathogenic microorganisms (PPM) (?16.7%; P < .001), CBI by any PPM (?37.4%; P < .001) and CBI by PA (?49.8%; P < .001). CBI by any PPM and ≥three previous exacerbations were associated with a better treatment response. 25.4% of patients presented non-severe side-effects, the most frequent of these being bronchospasm (10.5%), dyspnoea (8.8%) and cough (1.7%).ConclusionsIn COPD patients with multiple exacerbations and/or CBI by any PPM (especially PA), inhaled antibiotics appear to be an effective and safe treatment, regardless of the presence of bronchiectasis.  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