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   109248篇
  免费   9670篇
  国内免费   6164篇
耳鼻咽喉   1197篇
儿科学   1457篇
妇产科学   961篇
基础医学   11574篇
口腔科学   1839篇
临床医学   12715篇
内科学   13772篇
皮肤病学   1745篇
神经病学   4364篇
特种医学   4778篇
外国民族医学   21篇
外科学   11124篇
综合类   20142篇
现状与发展   35篇
一般理论   7篇
预防医学   9416篇
眼科学   2796篇
药学   12330篇
  97篇
中国医学   6843篇
肿瘤学   7869篇
  2024年   341篇
  2023年   1303篇
  2022年   3411篇
  2021年   4528篇
  2020年   3548篇
  2019年   2772篇
  2018年   2990篇
  2017年   3085篇
  2016年   3086篇
  2015年   4801篇
  2014年   6125篇
  2013年   6483篇
  2012年   9447篇
  2011年   9877篇
  2010年   7380篇
  2009年   6488篇
  2008年   7509篇
  2007年   7067篇
  2006年   6530篇
  2005年   5621篇
  2004年   4129篇
  2003年   3916篇
  2002年   3166篇
  2001年   2354篇
  2000年   1911篇
  1999年   1391篇
  1998年   817篇
  1997年   725篇
  1996年   627篇
  1995年   561篇
  1994年   549篇
  1993年   357篇
  1992年   386篇
  1991年   354篇
  1990年   294篇
  1989年   264篇
  1988年   179篇
  1987年   191篇
  1986年   146篇
  1985年   97篇
  1984年   57篇
  1983年   44篇
  1982年   42篇
  1981年   27篇
  1980年   27篇
  1979年   16篇
  1976年   7篇
  1975年   8篇
  1973年   10篇
  1972年   6篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
中药生产过程质量控制关键技术研究进展   总被引:10,自引:8,他引:2  
中医药发展已上升到国家战略层面,在医药行业贯彻实施"中国制造2025"战略的新形势下,中药生产过程质量控制是中药工业需要加快突破的关键领域之一。对中药生产过程质量控制领域在工艺设计、分析检测、过程建模、制造装备等方面的关键共性问题进行解析,综述了中药生产过程质量控制体系中工艺过程理解、生产过程实时分析方法开发、过程控制策略建立3个方面的研究进展;并结合企业研究实践,介绍了质量源于设计(quality by design,Qb D)、过程分析技术(process analytical technology,PAT)、实验设计(design of experiment,DOE)、多变量统计分析等关键技术在上述3个研究方向中的应用进展,分析了实际工业应用的难点问题并对其应用前景进行展望,旨在为中药企业应用和提升生产过程质量控制技术提供参考。  相似文献   
2.
3.
4.
目的:探讨保妇康凝胶联合诺氟沙星治疗宫颈糜烂的临床效果。方法将100例宫颈糜烂患者根据随机数字表法分为观察组和对照组各50例。观察组给予保妇康凝胶和诺氟沙星联合治疗,对照组单独给予治糜灵栓治疗,比较两组患者临床症状的变化,并对临床疗效进行评价。结果观察组治愈率为86.00%,明显高于对照组的74.00%,临床症状评分改善较对照组明显,且其临床症状消失的时间短于对照组,差异均有统计学意义(P<0.05)。结论保妇康凝胶与诺氟沙星合用比治糜灵栓治疗宫颈糜烂效果更佳,且治愈时间上明显较优,值得临床上推广应用。  相似文献   
5.
6.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.  相似文献   
7.
8.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF.  相似文献   
9.
Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese.  相似文献   
10.
This paper describes the use of a composite graft from the mastoid area consisting of full-thickness skin peripherally and selectively localised fascia-fat tissue underneath the skin centrally for immediate reconstruction of moderate defects of the nasal tip including the columella and soft triangle. Mastoid composite grafting is a simple and safe procedure that avoids partial graft loss and provides adequate augmentation of soft tissue, easy reshaping of the new nostril rim, minimal post-operative shrinkage, and no donor-site morbidity. Then, it results in a satisfactory nasal appearance with adequate tip projection and symmetry. This procedure may represent a preferred method of nasal tip reconstruction.  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