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   245篇
  免费   34篇
  国内免费   10篇
耳鼻咽喉   6篇
基础医学   18篇
口腔科学   3篇
临床医学   44篇
内科学   47篇
皮肤病学   8篇
神经病学   11篇
特种医学   12篇
外科学   29篇
综合类   32篇
现状与发展   1篇
预防医学   8篇
眼科学   2篇
药学   17篇
中国医学   7篇
肿瘤学   44篇
  2023年   21篇
  2022年   73篇
  2021年   38篇
  2020年   34篇
  2019年   7篇
  2018年   8篇
  2017年   5篇
  2016年   3篇
  2015年   9篇
  2014年   6篇
  2013年   9篇
  2012年   6篇
  2011年   8篇
  2010年   12篇
  2009年   9篇
  2008年   6篇
  2007年   7篇
  2006年   2篇
  2005年   8篇
  2004年   5篇
  2003年   3篇
  2001年   1篇
  1995年   1篇
  1994年   1篇
  1991年   2篇
  1988年   2篇
  1987年   1篇
  1984年   2篇
排序方式: 共有289条查询结果,搜索用时 15 毫秒
1.
熊丹  谢海花  李浩  张泓  谭洁  赵宁 《中国全科医学》2023,26(8):997-1007
背景 上肢运动功能障碍是脑卒中后常见的后遗症之一,严重影响患者日常生活能力。重复经颅磁刺激(rTMS)作为常见的神经电生理技术对治疗脑卒中后上肢运动功能障碍有较好的疗效,但临床对不同rTMS干预模式的选择仍缺乏循证依据。目的 采用网状Meta分析方法比较rTMS的4种模式对脑卒中后上肢运动功能障碍患者的临床疗效。方法 计算机检索PubMed、Embase、Cochrane Library、Web of Science、中国生物医学文献数据库、中国知网、万方数据知识服务平台、维普网中有关rTMS治疗脑卒中后上肢运动功能障碍的随机对照试验,并通过追溯Meta分析的参考文献作为补充。检索时间均为建库至2022年2月,采用主题词和自由词结合方式进行。2名研究者进行文献筛选、资料提取及质量评价。采用RevMan 5.0软件和Stata 16.0软件进行统计学分析。结果 最终纳入17篇文献,790例患者,共涉及6种干预措施:高频rTMS(HF-rTMS)、低频rTMS(LF-rTMS)、间断性theta节律刺激(iTBS)、连续性theta节律刺激(cTBS)、假刺激、常规疗法。网状Meta分析结...  相似文献   
2.
Guan  Xiu-Hao  Xu  Tian-Hua  Chen  Xi  Mu  Qi-Shuang  Suo  Jing-Fei  Xu  Rui-Xue  Chen  John  Xiao  Ting  Xing-Hua  Gao  Chen  Hong-Duo 《Lasers in medical science》2021,36(8):1619-1623
Lasers in Medical Science - This study is to determine the role of the fractional CO2 laser in topical drug delivery and the impact of local immune responses. Experimental rabbit nails were treated...  相似文献   
3.
目的观察转入 bak 基因对膀胱癌多药耐药(MDR)细胞的杀伤效果,探讨其可能的机制。方法用脂质体将 bak 基因导入 MDR 细胞,通过原位杂交法检测 bak mRNA 的表达,同时用 SABC 免疫组化法分析 bak 和 Bcl-2的表达。采用细胞计数法检测细胞生长抑制率,流式细胞仪检测细胞周期的变化。荧光染色观察细胞形态。结果转入 bak 基因后,MDR 细胞的生长明显受抑制(P<0.05)。细胞周期分析可见凋亡峰,凋亡率35%。细胞中可见 bak 阳性表达(P<0.05),Bck-2表达显著减少(P<0.05)。凋亡细胞在荧光显做镜下形成凋亡小体。结论转入 bak 基因可显著促进 MDR 细胞的凋亡,其作用机制与下调 Bcl-2基因的表达有关。  相似文献   
4.
目的 :研究异丙酚不同麻醉深度对兔脑海马c fosmRNA水平的影响。方法 :30只日本大耳兔 ,随机分为 3组 ,即对照组 ,浅麻醉组 ,深麻醉组。浅麻醉组 ,深麻醉组予以异丙酚靶控输注 (TCI)达到所需麻醉状态 30min后断头处死 ,0~ 4℃分离取脑 ,采用原位杂交法测定海马各区c fosmRNA表达水平。结果 :与对照组比较 ,海马CA1区 ,齿状回(DG)区c fosmRNA表达水平随着麻醉深度的增加而显著升高 (P <0 .0 5 )。海马CA3区未见明显变化。结论 :异丙酚可能通过影响c fosmRNA的表达 ,从而影响随后反应基因的转录而发挥抑制中枢的作用且此作用存在区域性差异。  相似文献   
5.
6.
PurposeTo compare the outcomes of self-expandable metal stent placement and percutaneous gastrostomy (PG) for the treatment of patients with esophageal cancer (EC) and dysphagia.Materials and MethodsThis retrospective observational study consisted of 113 patients with EC and dysphagia who underwent either stent placement (n = 47) or PG (n = 66) at a single center between June 2014 and June 2018.ResultsThere were 63 men and 50 women, with a mean age of 76.5 years (standard deviation 4.9 years). The 2 groups had similar baseline characteristics, except that the PG group had a higher percentage of patients with cervical EC (22.7% vs 2.1%, P < .001). The PG group had better maintenance of nutritional status in terms of reduction in serum albumin level (P = .039) and weight loss (P = .041). Compared with the stent group, the PG group demonstrated a lower incidence of local severe pain (0% vs 21.3%, P < .001) and lower incidence of dislodgment of device (1.5% vs 19.1%, P = .002). The PG group demonstrated longer overall survival compared with the stent group for Stages II and III (201 vs 185 days, P = .034) and Stage IV (122 vs 86 days, P = .001).ConclusionsCompared with stent insertion, PG is associated with better maintenance of nutritional status, fewer complications, and better survival. Thus, PG may be the preferred choice for treating malnutrition in patients with EC and dysphagia.  相似文献   
7.
8.
Background and study aimsData from Japanese series show that surface morphology of laterally spreading tumors (LST) in the colon identifies lesions with different incidence and pattern of submucosal invasion. Such data from western countries are scarce. We compared clinical and histological features of LST in a western country and an eastern country, with special interest on mucosal invasiveness of LST, and investigated the effect of clinical factors on invasiveness in both countries.Patients and methodsPatients with LST lesions ≥20 mm were included from a multicenter prospective registry in Spain and from a retrospective registry from the National Cancer Center Hospital East, Japan. The primary outcome was the presence of submucosal invasion in LST. The secondary outcome was the presence of high-risk histology, defined as high-grade dysplasia or submucosal invasion.ResultsWe evaluated 1102 patients in Spain and 663 in Japan. Morphological and histological characteristics differed. The prevalence of submucosal invasion in Japan was six-fold the prevalence in Spain (Prevalence Ratio PR = 5.66; 95%CI: 3.96, 8.08), and the prevalence of high-risk histology was 1.5 higher (PR = 1.44; 95%CI: 1.31, 1.58). Compared to the granular homogeneous type and adjusted by clinical features, granular mixed, flat elevated, and pseudo-depressed types were associated with higher odds of submucosal invasion in Japan, whereas only the pseudo-depressed type showed higher risk in Spain. Regarding high-risk histology, both granular mixed and pseudo-depressed were associated with higher odds in Japan, compared with only the granular mixed type in Spain.ConclusionThis study reveals differences in location, morphology and invasiveness of LST in an eastern and a western cohort.  相似文献   
9.
AimTo determine the prevalence of endoscopic lesions unrelated with portal hypertension in patients with cirrhosis.Patients and methodsCross-sectional study including a consecutive cohort of patients with liver cirrhosis enrolled in a screening program of oesophageal varices who underwent an upper gastrointestinal endoscopy from November, 2013, to November, 2018. Clinical predictors of endoscopic lesions unrelated to portal hypertension were analyzed by univariate and multivariate logistic regression.ResultsA total of 379 patients were included. The most frequent aetiology of liver disease was alcohol consumption (60.4%). The prevalence of endoscopic lesions unrelated with portal hypertension was 39.6% (n=150). Among 96 patients with peptic lesions, urease was obtained in 56.2% of patients (positive in 44.4% of them). The prevalence of endoscopic lesions unrelated to portal hypertension was not associated with age, gender, liver function or ultrasound findings of portal hypertension. The prevalence of endoscopic lesions unrelated to portal hypertension was not associated with age, gender, liver function or ultrasound findings of portal hypertension. Smokers had a trend to increased prevalence of endoscopic lesions unrelated to portal hypertension (43.2% vs. 34.6%; p=0.09), particularly peptic ulcer (6.4% vs. 0.6%; p=0.05) and peptic duodenitis (17.3% vs. 6.3%; p=0.002). Active smoking was the only independent predictor of peptic ulcer or duodenitis (OR=2.56; p=0.017).ConclusionActive smoking is a risk factor for endoscopic lesions unrelated to portal hypertension. This finding should be further investigated to reassess endoscopic screening programs in cirrhotic smokers.  相似文献   
10.
The use of intensity-modulated radiation therapy (IMRT) is developing rapidly in clinical routines. Because of the high complexity and uniqueness of IMRT treatment plans, patient-specific pretreatment quality assurance is generally considered a necessary prerequisite for patient treatment. In this work, we proposed a modified methodology of electronic portal imaging device (EPID)–based dose validation for pretreatment verification of IMRT fields by applying artificial neural networks (ANNs). The ANN must be trained and validated before use for pretreatment dose verification. For this purpose, 20 EPID fluence maps of IMRT prostate anterior-posterior fields were used as an input for ANN (feed forward type) and a dose map of those fluence maps that were predicted by treatment planning system as an output for ANN. After the training and validation of the neural network, the analysis of 10 IMRT prostate anterior-posterior fields showed excellent agreement between ANN output and dose map predicted by the treatment planning system. The average overall fields pass rate was 96.0% ± 0.1% with 3 mm/3% criteria. The results indicated that the ANN can be used as a low-cost, fast, and powerful tool for pretreatment dose verification, based on an EPID fluence map.  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