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   119287篇
  免费   11773篇
  国内免费   7602篇
耳鼻咽喉   978篇
儿科学   1862篇
妇产科学   1388篇
基础医学   12269篇
口腔科学   2287篇
临床医学   14939篇
内科学   15836篇
皮肤病学   1176篇
神经病学   5325篇
特种医学   4405篇
外国民族医学   32篇
外科学   11491篇
综合类   23571篇
现状与发展   21篇
一般理论   12篇
预防医学   9850篇
眼科学   2617篇
药学   13031篇
  158篇
中国医学   8757篇
肿瘤学   8657篇
  2025年   25篇
  2024年   1668篇
  2023年   2278篇
  2022年   4506篇
  2021年   5595篇
  2020年   4583篇
  2019年   3375篇
  2018年   3549篇
  2017年   3596篇
  2016年   3207篇
  2015年   5101篇
  2014年   6180篇
  2013年   6408篇
  2012年   9612篇
  2011年   10117篇
  2010年   7574篇
  2009年   6248篇
  2008年   7556篇
  2007年   7132篇
  2006年   6614篇
  2005年   5851篇
  2004年   4235篇
  2003年   3698篇
  2002年   3128篇
  2001年   2606篇
  2000年   2504篇
  1999年   2202篇
  1998年   1311篇
  1997年   1279篇
  1996年   1014篇
  1995年   987篇
  1994年   804篇
  1993年   498篇
  1992年   571篇
  1991年   518篇
  1990年   441篇
  1989年   392篇
  1988年   305篇
  1987年   314篇
  1986年   244篇
  1985年   197篇
  1984年   129篇
  1983年   91篇
  1982年   66篇
  1981年   47篇
  1980年   34篇
  1979年   44篇
  1978年   18篇
  1973年   17篇
  1966年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Pachymic acid (PA) is a lanostane type triterpenoid isolated from Poria cocos, which possesses an anti-tumor effect in breast cancer, prostate cancer, lung cancer, and bladder cancer cells. In this study, we investigated the effect of PA on the growth and apoptosis of human immortalized cell line (HOS) and primary osteosarcoma cells by a Cell Counting Kit-8 (CCK-8) and Annexin V and propidium iodide (PI) staining, respectively. Western blot was used to measure the expression of cleaved Caspase 3, PTEN, and AKT, as well as the AKT phosphorylation. The Caspase 3 activity was determined using the Caspase-3 Colorimetric Assay Kit. From the results, PA significantly reduced cell proliferation in a concentration- and time-dependent manner. PA also induced cell apoptosis in a dose-dependent fashion. PA treatment led to increased Caspase 3 activation and PTEN expression, as well as reduced AKT phosphorylation. Moreover, Ac-DEVD-CHO (a Caspase 3/7 inhibitor) pre-treatment or PTEN knockdown partially blocked the effects of PA on cell proliferation and apoptosis. Caspase 3/7 inhibitor had an additive effect with PTEN knockdown. Collectively, our results suggested that induction of apoptosis by PA was mediated in part by PTEN/AKT signaling and Caspase 3/7 activity. This study provides evidence that PA might be useful in the treatment of human osteosarcoma.  相似文献   
12.
13.
目的观察谷氨酰胺联合益生菌对失代偿肝硬化患者的疗效与安全性。方法收集本院失代偿肝硬化患者78例,随机分为2组,每组39例:对照组用常规治疗;在常规治疗的基础上,试验组用谷氨酰胺联合益生菌治疗,复方谷氨酰胺肠溶胶囊,每次750 mg;枯草杆菌二联活菌肠溶胶囊口服,每次250 mg,两药均每天3次,连用4周。治疗前后,测定2组的肠黏膜通透性指标、肝功能指标、疗效和药物不良反应(ADR)发生率。结果治疗后,试验组与对照组的尿乳果糖/甘露醇比值分别是0.09±0.06,0.12±0.08,这2组的血清白细胞介素-8水平分别是(15.02±3.69),(18.45±4.10)ng·L-1,这2组的血清谷丙转氨酶水平分别是(24.61±14.29),(36.82±15.67)U·L-1,上述3个指标在组间比较差异均有统计学意义(均P<0.05)。对照组和试验组的改善率分别为71.80%,92.31%,差异有统计学意义(P<0.05)。对照组和试验组的ADR发生率分别为15.38%(6例/39例),20.51%(8例/39例),组间比较差异无统计学意义(P>0.05)。结论谷氨酰胺联合益生菌对失代偿肝硬化患者的治疗效果确切,有助于降低肠黏膜通透性和提高肝功能;且不增加ADR发生率。  相似文献   
14.
15.
16.
There are several drug products that bind phosphate or bile acid in the gastrointestinal (GI) tract to exert their therapeutic efficacy. In vitro binding studies are used to assess bioequivalence (BE) of these products. The objective of this study is to identify the common deficiencies in Abbreviated New Drug Applications (ANDAs) for these products. Deficiencies were compiled from ANDAs containing in vitro binding BE studies. The deficiencies were classified into eight categories: Pre-Study Method Validation, During-Study Sample Analysis, Study Design, Study Procedure, Dissolution/Disintegration, Analytical Site Inspection, Data Submission, and Formulations. Within each category, additional subcategories were defined to characterize the deficiencies. A total of 712 deficiencies from 95 ANDAs for 11 drug products were identified and included in the analysis. The four categories with the most deficiencies were During-Study Sample Analysis (27.8%), Pre-Study Method Validation (17.3%), Data Submission (16.7%), and Study Design (15.7%). For the During-Study Sample Analysis category, failure to submit complete raw data or analytical runs ranked as the top deficiency (32.8%). For the Study Design category, using an unacceptable alternate study design (26.8%) was the most common deficiency. Within this category, other commonly occurring deficiencies included incorrect/insufficient number of absorbent concentrations, failure to pre-treat drug product with acid, insufficient number of replicates in study, incorrect calculation of k1 and k2 values, incorrect dosage form or pooled samples used in the study, and incorrect pH of study medium. The review and approval of these products may be accelerated if these common deficiencies are addressed in the original ANDA submissions.  相似文献   
17.
Liu  Ruyu  Guo  Jiang  Lu  Yao  Zhang  Lu  Shen  Ge  Wu  Shuling  Chang  Mi  Hu  Leiping  Hao  Hongxiao  Li  Minghui  Xie  Yao 《Clinical and experimental medicine》2019,19(3):309-320
Clinical and Experimental Medicine - According to guidelines, antiviral therapy for adults with immune-active chronic hepatitis B (CHB) should be adopted to decrease the risk of liver-related...  相似文献   
18.
The consequences of once-weekly rifapentine plus isoniazid for 3 months (3HP) against latent tuberculosis infections in hemodialysis patients have not been studied before. This is the first study to evaluate the safety and tolerability of 3HP in this population and revealed a completion rate of 65.4%. The therapy was not associated with hepatotoxicity, but with high rates of adverse events (69.2%).  相似文献   
19.
We assessed the prevalence characteristics of single and multiple high-risk human papillomavirus (HR-HPV) infections. A total of 1783 women who underwent colposcopy and cervical biopsy for abnormal ThinPrep Cytology Test and/or HR-HPV subtype genotyping results were enrolled in the study. Among the participants, 770 were diagnosed with cervicitis, 395 with cervical intraepithelial neoplasia grade 1 (CIN1), 542 with CIN2-3, and 76 with squamous cell carcinoma (SCC), with HR-HPV infection rates of 75.8%, 85.8%, 95.9%, and 88.4%, respectively. The prevalence of total and multiple HR-HPV infections exhibited a bimodal age distribution with a peak at ≤25 years, a decline with age and a second peak at ≥55 years, whereas single HR-HPV infections exhibited one peak from 35 to 44 years. The four most dominant HPV genotypes were HPV 16 (29.5%), 52 (15.0%), 58 (14.2%), and 18 (10.4%). In total, 67.0%, 70.4%, and 82.1% of patients with CIN1, CIN2-3, and SCC, respectively, had a single HR-HPV infection, which increased significantly with the aggravation of the cervical lesion grade (P = 0.045). Patients with a single HPV 16 infection had higher incidences of CIN2+ (62.2%) than those with multiple HPV 16 infections (52.4%) (P = 0.021). Patients coinfected with HPV 16 had higher CIN2+ incidence than those with single HPV 52, 31, 33, 35, 39, 45, 51, 56, or 59 infections (P < 0.001). This study provided baseline data on the prevalence characteristics of single and multiple HR-HPV infections in women attending a gynecological outpatient clinic in Beijing.  相似文献   
20.
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