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   7701篇
  免费   444篇
  国内免费   154篇
耳鼻咽喉   519篇
儿科学   208篇
妇产科学   322篇
基础医学   695篇
口腔科学   69篇
临床医学   1263篇
内科学   514篇
皮肤病学   33篇
神经病学   194篇
特种医学   270篇
外国民族医学   1篇
外科学   998篇
综合类   1253篇
预防医学   873篇
眼科学   230篇
药学   485篇
  7篇
中国医学   157篇
肿瘤学   208篇
  2024年   10篇
  2023年   91篇
  2022年   219篇
  2021年   293篇
  2020年   271篇
  2019年   205篇
  2018年   205篇
  2017年   219篇
  2016年   262篇
  2015年   251篇
  2014年   567篇
  2013年   516篇
  2012年   559篇
  2011年   561篇
  2010年   437篇
  2009年   388篇
  2008年   339篇
  2007年   377篇
  2006年   330篇
  2005年   317篇
  2004年   237篇
  2003年   198篇
  2002年   158篇
  2001年   139篇
  2000年   132篇
  1999年   104篇
  1998年   118篇
  1997年   80篇
  1996年   86篇
  1995年   80篇
  1994年   77篇
  1993年   49篇
  1992年   46篇
  1991年   42篇
  1990年   35篇
  1989年   37篇
  1988年   34篇
  1987年   31篇
  1986年   26篇
  1985年   41篇
  1984年   24篇
  1983年   19篇
  1982年   17篇
  1981年   10篇
  1980年   15篇
  1979年   13篇
  1978年   13篇
  1977年   5篇
  1976年   7篇
  1973年   4篇
排序方式: 共有8299条查询结果,搜索用时 15 毫秒
101.
目的探讨采用自制气囊引流管行结肠旁路引流在医源性结肠穿孔患者中的临床应用价值。方法回顾性分析2009年1月至2011年3月间哈尔滨医科大学附属第二医院消化内科采用自行设计的结肠气囊引流管治疗的8例医源性结肠穿孔患者的临床资料。所有结肠穿孔在内镜下金属夹和(或)尼龙绳缝合后。将自制气囊引流管在内镜直视下留置于肠腔内.引流管前端气囊充气后固定于穿孔部位的近口侧.后端固定于患者臀部并行持续引流肠液及粪便。结果8例患者气囊引流管均成功放置并引流通畅.穿孔均完全愈合.无中转外科手术病例。气囊引流管旁路引流时间3-10(平均7.6)d,1例患者术后3d复查结肠镜,发现气囊导管移位,予以内镜下校正。所有8例患者气囊引流管均顺利拔除。拔除后肠壁气囊固定部位无溃疡穿孔发生。术后随访12-36(平均25.4)个月,全组患者术后无慢性肠瘘、粘连性肠梗阻或腹腔感染等并发症发生。结论应用自制气囊引流管行结肠旁路引流治疗医源性结肠穿孔简单、安全并可靠。  相似文献   
102.
Antifibrinolytic agents such as aprotinin and epsilon aminocaproic acid limit postoperative bleeding and blood transfusion in patients undergoing cardiac operations using cardiopulmonary bypass (CPB). Recent evidence suggests that these agents have adverse side effects that influence operative mortality and morbidity. We studied postoperative bleeding, transfusion rates, and operative outcomes in our patients in order to assess the efficacy of these agents during cardiac operations requiring CPB. We reviewed records of 520 patients undergoing a variety of cardiac operations between January 2005 and May 2009. We measured multiple variables including pre-operative risk factors, antifibrinolytic agent used, and outcomes of operation, such as measures of bleeding and blood transfusion, as well as serious operative morbidity and mortality. Postoperative bleeding rates varied significantly between patients receiving aprotinin and those receiving aminocaproic acid (P < 0.05). There was an associated 12% decrease in operative site bleeding in aprotinin-treated patients compared with aminocaproic acid. There was no significant difference in the transfusion rates of packed red blood cells between patients receiving aminocaproic acid or aprotinin (P > 0.05), though individuals in the aprotinin group did receive FFP more frequently than patients in the aminocaproic acid group (P < 0.05). There was no significant difference in morbidity and mortality rates between patients in either drug group (P > 0.05). Our study shows that aprotinin is more effective at controlling operative site bleeding than aminocaproic acid. Reduced operative site bleeding did not portend better outcome or differences in transfusion requirements. Aminocaproic acid remains a safe and cost-effective option for antifibrinolytic prophylaxis because of unavailability of aprotinin.  相似文献   
103.
Torsion of the fallopian tube accompanying hydrosalpinx is a rare occurrence in the pediatric population. This report describes a 13 year old sexually inactive girl with isolated tubal torsion due to hydrosalpinx. The girl had lower left abdominal pain for two days. The physical examination revealed left lower quadrant tenderness with a firm round anterior mass on rectal examination. Abdominal ultrasound showed left tubal enlargement with free pelvic peritoneal fluid. Magnetic Resonance Imaging (MRI) showed engorgement and dilatation of the left fallopian tube without contrast enhancement suspicious of tubal torsion. At operation, torsion of the left tube on its longitudinal axis was observed, and a salpingectomy was performed.  相似文献   
104.
Ingestion of caustic agents may result in severe scarring and stricture formation of the esophagus. Reversed gastric tube esophagoplasty is an option for definitive surgical management of severe esophageal stricture refractory to medical treatment. Delayed complications from this procedure have rarely been reported. We present a case involving a patient who developed a delayed gastric stricture three decades after receiving a reversed gastric tube esophagoplasty. A historical review of the reversed gastroplasty is presented as well.  相似文献   
105.

Background/purpose

Esophageal reconstruction in long-gap esophageal atresia (EA) poses a technical challenge with several surgical options. The purpose of this study was to review the authors’ experience with the reversed gastric tube (RGT) in esophageal reconstruction.

Methods

This series describes 7 babies with pure EA treated at 2 centers between 1989 and 2001. Data, gathered by retrospective chart review, included clinical details of the esophageal and associated malformations, technique and timing of repair, early and late complications, and long-term follow-up. Institutional review board (IRB) approval of this study has been obtained.

Results

Seven babies were included. Associated malformations were present in 4: trisomy 21 in 2 and imperforate anus in 2. After gastrostomy tube placement, patients were treated with gastrostomy tube feedings and continuous upper pouch suction. Median gap length was 5.5 vertebral segments (range, 3 to 9). RGT with a posterior mediastinal esophagogastric anastomosis was performed at median age of 62 days (range, 38 to 131). There were no anastomotic leaks. Three patients had strictures, one required resection. Exclusive oral nourishment was achieved in 5 patients by 6 months of age. At last follow-up (mean, 4.5 years), 6 patients were receiving oral nutrition exclusively, and all were maintaining growth curves.

Conclusions

In long gap EA, early esophageal reconstruction using an RGT can be performed with minimal morbidity and promising short-term results.  相似文献   
106.
目的了解社区老年留置胃管患者口腔健康状况并分析其影响因素。方法采用一般资料调查问卷、日常生活活动能力量表、改良版Beck口腔评分表和流行病研究中心抑郁调查量表,对127例社区老年留置胃管患者及其主要照护者进行调查,并对患者口腔pH值进行测量。结果社区老年留置胃管患者Beck口腔得分为(10.02±2.39)分,96.85%患者存在不同程度的口腔功能受损,71.65%患者口腔pH值呈酸性。多重线性回归分析结果显示,患者胃管留置时间、清洁口腔频率、口腔pH值,以及照护者与患者关系、刷牙频率、抑郁程度为老年留置胃管患者口腔健康状况的影响因素(P0.05,P0.01)。结论社区老年留置胃管患者口腔健康状况不容乐观,主要照护者应重视老年患者留置胃管的口腔清洁,家属和社区工作者应提供正确的指引并关爱照护者,培养其正确的刷牙习惯。  相似文献   
107.
目的系统评价经鼻肠内营养管(NJT)与空肠造口置管(JT)两种不同营养途径在上消化道改建术后病人肠内营养的临床效果。方法计算机检索PubMed、EMbase、Web of science、The Cochrane Library(2015年第9期)、中国生物医学文献数据库(CBM)、中国知网、维普、万方数据等数据库,查找所有比较术后NJT与JT行肠内营养的上腹部肠道改建手术的随机对照试验(RCT),检索时限为从建库至2015年9月。由2位研究者按纳入与排除标准独立筛选文献、提取资料和评价文献质量后,进行Meta分析。结果最终纳入7个RCT,包括544例病人。Meta结果显示:虽然JT组术后总并发症发生率少于NJT组[RR=0.58,95%CI(0.38,0.90),P=0.02],但与管道相关并发症发生率两组差异无统计学意义[RR=1.30,95%CI(0.93,1.81),P=0.12];两组肠内营养置管后不能耐受发生率差异无统计学意义[RD=-0.08,95%CI(-0.20,0.03),P=0.16];术后主要并发症吻合口漏及肺炎两组差异无统计学意义(P0.05);肠功能恢复时间JT组明显短于NJT组[SMD=-1.19,95%CI(-1.77,-0.60),P0.0001],两组比较差异有统计学意义。结论两种肠内营养途径均是安全有效的方法,但JT在促进肠功能恢复和减少术后总并发症方面更有优势。  相似文献   
108.
目的:探讨胸腔镜胸腺切除术后不留置引流管的临床效果及安全性。方法:采用随机对照法比较胸腔镜胸腺切除术后留置与不留置引流管的临床效果,利用计算机产生随机数字的方法将2014年5月至2016年5月就诊的54例良性胸腺肿瘤患者分为观察组(n=27)与对照组(n=27)。观察组胸腔镜胸腺切除术后不留置引流管,对照组术后则留置引流管。对比评估两组手术时间、术中出血量、术后住院时间、术后疼痛度及术后并发症情况。结果:两组均顺利完成手术。观察组术后住院时间短于对照组,差异有统计学意义(t=-5.811,P0.001),两组术中出血量、手术时间差异无统计学意义(P0.05)。术后第1天、第3天,观察组疼痛度低于对照组,差异有统计学意义(t=-6.244,P0.001;t=-5.988,P0.001)。术后并发症发生率两组相比差异无统计学意义(P0.05)。结论:胸腔镜胸腺切除术后不留置引流管可缩短住院时间,减轻术后疼痛,改善术后生活质量,且不增加术后并发症的发生风险,是安全、可行的。  相似文献   
109.
晚期胰腺癌导致的胆道及十二指肠梗阻患者生存期一般较短,对此类患者应以最小的创伤方法治疗为主。本文报道1例晚期胰腺癌导致的胆道及十二指肠梗阻患者,胆道梗阻给予胆道支架治疗后解除了梗阻性黄疸,由于此患者心脏功能不全不能耐受胃空肠吻合术,并且在DSA下和内窥镜下放置支架及营养管失败,最后采取经肝、胆道支架放置营养管治疗,获得了一定的疗效。  相似文献   
110.

Background

Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes.

Methods

In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration.

Results

In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation.

Conclusion

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.

Registration of Clinical Trial

DRKS-ID DRKS00014788 ( www.drks.de ).  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