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   8668篇
  免费   714篇
  国内免费   290篇
耳鼻咽喉   431篇
儿科学   25篇
妇产科学   69篇
基础医学   392篇
口腔科学   213篇
临床医学   1007篇
内科学   2272篇
皮肤病学   16篇
神经病学   249篇
特种医学   334篇
外国民族医学   2篇
外科学   2346篇
综合类   937篇
预防医学   126篇
眼科学   34篇
药学   216篇
  4篇
中国医学   30篇
肿瘤学   969篇
  2025年   8篇
  2024年   175篇
  2023年   292篇
  2022年   427篇
  2021年   564篇
  2020年   537篇
  2019年   472篇
  2018年   439篇
  2017年   345篇
  2016年   369篇
  2015年   342篇
  2014年   767篇
  2013年   558篇
  2012年   498篇
  2011年   555篇
  2010年   392篇
  2009年   366篇
  2008年   392篇
  2007年   347篇
  2006年   293篇
  2005年   229篇
  2004年   196篇
  2003年   162篇
  2002年   133篇
  2001年   100篇
  2000年   81篇
  1999年   92篇
  1998年   77篇
  1997年   75篇
  1996年   52篇
  1995年   49篇
  1994年   57篇
  1993年   42篇
  1992年   43篇
  1991年   39篇
  1990年   12篇
  1989年   16篇
  1988年   10篇
  1987年   12篇
  1986年   7篇
  1985年   6篇
  1984年   6篇
  1983年   7篇
  1982年   6篇
  1981年   5篇
  1980年   9篇
  1979年   2篇
  1978年   2篇
  1976年   4篇
  1972年   1篇
排序方式: 共有9672条查询结果,搜索用时 15 毫秒
1.

Objective

To compare perioperative and long-term outcomes in patients undergoing hemiarch and aggressive arch replacement for acute type A aortic dissection (ATAAD).

Methods

From 1996 to 2017, we compared outcomes of hemiarch (n = 322) versus aggressive arch replacements (zones 2 and 3 arch replacement with implantation of 2-4 arch branches, n = 150) in ATAAD. Indications for aggressive arch were arch aneurysm >4 cm or intimal tear in the aortic arch that was not resectable by hemiarch replacement, or dissection of arch branches with malperfusion.

Results

Patients in the aggressive arch group were significantly younger (mean age: 57 vs 61 years old) and had significantly longer hypothermic circulatory arrest, cardiopulmonary bypass, and aortic crossclamp times. There were no significant differences in perioperative outcomes between hemiarch and aggressive arch groups, including 30-day mortality (5.3% vs 7.3%, P = .38) and postoperative stroke rate (7% vs 7%, P = .96). Over 15 years, Kaplan–Meier survival was similar between hemiarch and aggressive arch groups (log-rank P = .55, 10-year survival 70% vs 72%). Given death as a competing factor, incidence rates of reoperation over 15 years (2.1% vs 2.0% per year, P = 1) and 10-year cumulative incidence of reoperation (14% vs 12%, P = .89) for arch and distal aorta pathology were similar between the 2 groups.

Conclusions

Both hemiarch and aggressive arch replacement are appropriate approaches for select patients with ATAAD. Aggressive arch replacement should be considered for an arch aneurysm >4 cm or an intimal tear at the arch unable to be resected by hemiarch replacement, or dissection of the arch branches with malperfusion.  相似文献   
2.
IntroductionThis report evaluates whether health related quality of life (HRQoL) and patient-reported arm morbidity one year after axillary surgery are affected by the omission of axillary lymph node dissection (ALND).MethodsThe ongoing international non-inferiority SENOMAC trial randomizes clinically node-negative breast cancer patients (T1-T3) with 1–2 sentinel lymph node (SLN) macrometastases to completion ALND or no further axillary surgery. For this analysis, the first 1181 patients enrolled in Sweden and Denmark between March 2015, and June 2019, were eligible. Data extraction from the trial database was on November 2020. This report covers the secondary outcomes of the SENOMAC trial: HRQoL and patient-reported arm morbidity. The EORTC QLQ-C30, EORTC QLQ-BR23 and Lymph-ICF questionnaires were completed in the early postoperative phase and at one-year follow-up. Adjusted one-year mean scores and mean differences between the groups are presented corrected for multiple testing.ResultsOverall, 976 questionnaires (501 in the SLN biopsy only group and 475 in the completion ALND group) were analysed, corresponding to a response rate of 82.6%. No significant group differences in overall HRQoL were identified. Participants receiving SLN biopsy only, reported significantly lower symptom scores on the EORTC subscales of pain, arm symptoms and breast symptoms. The Lymph-ICF domain scores of physical function, mental function and mobility activities were significantly in favour of the SLN biopsy only group.ConclusionOne year after surgery, arm morbidity is significantly worse affected by ALND than by SLN biopsy only. The results underline the importance of ongoing attempts to safely de-escalate axillary surgery.Trial registrationThe trial was registered at clinicaltrials.gov prior to initiation (https://clinicaltrials.gov/ct2/show/NCT 02240472).  相似文献   
3.
Polycystic kidney disease (PKD) is a multiple cystic disease involving both the kidneys. Some studies have reported cases of patients with PKD and concurrent aortic dissection; however, autopsy has been performed in only few of these cases. Here, we present the case of a 62-year-old male patient with PKD who showed generalized vascular degeneration, including aortic dissection. The patient had a family history of autosomal dominant PKD and was brought to our hospital because of cardiopulmonary arrest. He was diagnosed with Stanford type A aortic dissection and died on the same day, despite being under cardiopulmonary resuscitation. Autopsy detected multiple cysts in the kidneys, liver, pancreas, and testes. Moreover, multiple tears in the vascular wall of the splenic artery and superior mesenteric artery, including the aorta, were observed. The case findings indicate that patients with PKD may develop associated generalized vascular disease; however, development of cerebral aneurysms and aortic dissections with PKD is particularly serious. Therefore, suitable screening tests must be developed for the early diagnosis and disease characterization, thus, ensuring that the appropriate treatment is administered to the patients.  相似文献   
4.
5.
目的 系统评价我国腹腔镜D2淋巴结清扫术联合远端胃癌切除术治疗进展期远端胃癌的有效性和安全性。方法 计算机检索PubMed数据库、Cochrane图书馆、中国科学引文数据库(China science citation database,CSCD)、万方数据库(Wanfang)、中文科技期刊数据库(China science and technology journal database,CSTJ)、中国生物医学文献数据库(China biomedical literature database,CBM)和中国学术期刊网络出版总库(China academic journal network publishing database,CAJD)数据库,检索时限均从建库至2013年6月。采用Review Manager 5.2软件进行Meta分析。结果 最终纳入了7个临床随机对照试验,共548例进展期胃癌患者。Meta分析结果显示:与传统开放式远端胃癌切除术(CODG)相比,腹腔镜辅助远端胃癌切除术 (LADG)的术中出血量少(MD =-94.02,95% CI:-140.96~-47.07)、术后住院时间短(MD =-3.66,95% CI:-5.76~-1.57)、术后下床活动时间早(MD =-1.95,95% CI:-2.74~-1.17)、肛门排气时间早(MD =-1.67,95% CI:-2.05~-1.30)、总并发症发生率低(OR=0.26,95% CI:0.14~0.51),差异均有统计学意义(P<0.050),但LADG组的手术时间长于CODG组(MD =35.01,95% CI:10.41~59.61,P=0.005)。2组间淋巴结清扫数量比较差异无统计学意义 (MD =-0.24,95% CI:-0.99~0.51,P=0.530)。结论 LADG的近期疗效及安全性均优于传统CODG,但其手术时间长,远期疗效尚需进一步探究。  相似文献   
6.
目的总结不同主动脉断端加固方法在主动脉夹层手术中的应用及其效果。方法2012年1月至2013年5月,共有95例主动脉夹层在南京医科大学附属南京医院接受手术治疗。根据主动脉断端的加固方法不同,将其中72例患者(23例Bentall手术患者未纳入本研究)分为3组,A组:23例,男18例、女5例,年龄(48.67±9.23)岁,其中主动脉壁内外均使用毛毡条行“三明治”加固;B组:11例,男8例、女3例,年龄(48.00±9.17)岁,仅主动脉内膜内侧使用心包条加固;C组:38例,男29例、女9例,年龄(49.20±8.57)岁,主动脉断端不进行任何加固,与人工血管直接吻合。分析并比较3组患者的术后转归情况。结果术后住院死亡8例[其中A组1例(4.35%,1/23),C组7例(18.42%,7/38)],住院死亡率11.11%。1例(A组)死于创面广泛渗血,最后出现弥散性血管内凝血;3例(均为C组)死于术后针眼、吻合口广泛渗血,循环不能维持;4例(均为C组)术后三尖瓣重度反流,继发严重低心排血量综合征,最终导致多脏器功能衰竭而死亡。术后严重并发症包括肾功能衰竭5例,呼吸功能不全7例,严重脑梗死致偏瘫1例,轻瘫3例,延迟苏醒2例,下肢缺血坏死1例。术后胸腔引流量C组最多,A组胸腔引流量与B组比较差异无统计学意义。随访64例,随访时间1~6个月。随访期间无死亡。5例肾功能衰竭患者中只有1例定期行血液透析治疗,其余4例患者肾功能均恢复正常;1例脑梗死患者肢体功能部分恢复,可以拄拐行走;3例轻瘫患者肢体功能均恢复正常。结论主动脉夹层断端的吻合质量异常重要,术中可根据具体情况选择合适的加固方式;使用毛毡条行“三明治”加固可以减少吻合口渗血,预防吻合口撕裂所致急性心肌梗死的发生,降低术后死亡率;若主动脉夹层剥离累及冠状动脉开口,需同期行冠状动脉旁路移植术。  相似文献   
7.

Context

Ischemia of the cervical spinal cord is a rare complication of spontaneous vertebral artery dissection (VAD) and usually involves the ventral portion. We describe a less evocative clinical presentation and images of unilateral posterior spinal cord infarction due to spontaneous VAD in order to facilitate early diagnosis.

Findings

A previously fit 30-year-old man presented with persistent headaches and proximal motor deficit of the right arm. He was diagnosed with spontaneous dissection of both vertebral arteries, with occlusion of the right one, and the right carotid artery. Neurological examination also revealed a right C2–C3 tactile sensory loss, with unilateral proprioceptive deficit below. Brain images revealed small bilateral cerebellar infarcts which could not be responsible for the clinical symptoms. Magnetic resonance imaging of the spinal cord showed a right posterior cervical spinal cord infarction. The patient achieved nearly complete recovery after several weeks of anticoagulation and rehabilitation.

Conclusion and clinical relevance

Infarction of the caudal portion of the cervical spinal cord, especially unilateral, caused by spontaneous VAD, has rarely been described and is certainly under-diagnosed due to less suggestive symptoms, like unilateral and mainly sensory deficit. Nevertheless, early diagnosis of this condition is important to guide patient management and rehabilitation.  相似文献   
8.
9.
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