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   16378篇
  免费   1700篇
  国内免费   528篇
耳鼻咽喉   1203篇
儿科学   90篇
妇产科学   135篇
基础医学   639篇
口腔科学   249篇
临床医学   2027篇
内科学   5629篇
皮肤病学   18篇
神经病学   410篇
特种医学   472篇
外国民族医学   2篇
外科学   3802篇
综合类   1785篇
预防医学   282篇
眼科学   147篇
药学   441篇
  11篇
中国医学   82篇
肿瘤学   1182篇
  2024年   9篇
  2023年   498篇
  2022年   600篇
  2021年   901篇
  2020年   1025篇
  2019年   839篇
  2018年   782篇
  2017年   739篇
  2016年   786篇
  2015年   694篇
  2014年   1430篇
  2013年   1237篇
  2012年   954篇
  2011年   1074篇
  2010年   818篇
  2009年   778篇
  2008年   777篇
  2007年   722篇
  2006年   619篇
  2005年   507篇
  2004年   481篇
  2003年   361篇
  2002年   310篇
  2001年   224篇
  2000年   197篇
  1999年   173篇
  1998年   162篇
  1997年   123篇
  1996年   87篇
  1995年   110篇
  1994年   120篇
  1993年   88篇
  1992年   83篇
  1991年   77篇
  1990年   50篇
  1989年   35篇
  1988年   26篇
  1987年   20篇
  1986年   13篇
  1985年   12篇
  1984年   10篇
  1983年   12篇
  1982年   9篇
  1981年   6篇
  1980年   12篇
  1979年   3篇
  1978年   3篇
  1977年   2篇
  1976年   4篇
  1975年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
ObjectiveTo evaluate the long-term incidence and outcome of aortic interventions for medically managed uncomplicated thoracic aortic dissections.MethodsBetween January 2012 and December 2018, 91 patients were discharged home with an uncomplicated, medically treated aortic dissection (involving the descending aorta with or without aortic arch involvement, no ascending involvement). After a median period of 4 (first quartile: 2, third quartile: 11) months, 30 patients (33%) required an aortic intervention. Patient characteristics, radiographic, treatment, and follow-up data were compared for patients with and without aortic interventions. A competing risk regression model was analyzed to identify independent predictors of aortic intervention and to predict the risk for intervention.ResultsPatients who underwent aortic interventions had significantly larger thoracic (P = .041) and abdominal (P = .015) aortic diameters, the dissection was significantly longer (P = .035), there were more communications between both lumina (P = .040), and the first communication was significantly closer to the left subclavian artery (P = .049). A descending thoracic aortic diameter exceeding 45 mm was predictive for an aortic intervention (P = .001; subdistribution hazard ratio: 3.51). The risk for aortic intervention was 27% ± 10% and 36% ± 11% after 1 and 3 years, respectively. Fourteen patients (47%) underwent thoracic endovascular aortic repair, 11 patients (37%) thoracic endovascular aortic repair and left carotid to subclavian bypass, 3 patients (10%) total arch replacement with the frozen elephant trunk technique, and 2 patients (7%) thoracoabdominal aortic replacement. We observed no in-hospital mortality.ConclusionsThe need for secondary aortic interventions in patients with initially medically managed, uncomplicated descending aortic dissections is substantial. The full spectrum of aortic treatment options (endovascular, hybrid, conventional open surgical) is required in these patients.  相似文献   
3.
IntroductionIntensive local treatment comprising total mesorectal excision (TME) with selective lateral pelvic lymph node dissection (LPND) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) has received attention among clinicians treating rectal cancer. It remains unclear whether adjuvant chemotherapy (ACT) after intensive local treatment is beneficial for these patients. We evaluated the oncologic benefit of ACT for patients with LARC who received intensive local treatment.Materials and methodsThis international multicentre retrospective cohort study included 737 patients treated in Japan and Korea between 2010 and 2017. The effectiveness of ACT on recurrence-free survival (RFS) was evaluated using univariable and multivariable Cox proportional hazards models, with subgroup analyses to identify subpopulations potentially benefiting from ACT.ResultsThe median follow-up was 49 months; the 5-year RFS and local recurrence rates for the entire cohort were 72.1% and 4.9%, respectively; 514 patients (69.7%) received adjuvant chemotherapy, without an oncologic benefit (hazard ratio, 1.14; 95% confidence interval [CI]: 0.79–1.68) demonstrated in the multivariable Cox regression analysis. In subgroup analyses, the distributions of the 95% CI in patients aged ≥70 years and those with ypStage 0 tended to place a disproportionate emphasis that favoured the non-ACT treatment strategy.ConclusionDespite achieving good local control with intensive local treatment strategy, the effectiveness of ACT for the LARC patients with CRT followed by TME with selective LPND was not proved. Elderly patients and those with ypStage0 may not receive benefit from ACT after CRT and TME ± LPND.  相似文献   
4.
5.
目的 探讨主动脉夹层术后患者心理状况、躯体症状对其生活质量的影响及作用机制,为制订干预计划提供参考。方法 采用广泛性焦虑障碍量表、患者健康问卷抑郁量表、躯体症状量表、12项简明健康状况调查表对327例主动脉夹层术后患者进行调查,根据相关性分析结果提出假设,应用AMOS软件进行结构方程模型分析。结果 主动脉夹层术后患者生活质量得分(81.56±7.36)分,焦虑得分2.00(0, 3.00)分,抑郁得分2.00(0, 3.00)分,躯体症状得分5.00(2.00, 8.00)分;焦虑、抑郁、躯体症状对生活质量有直接影响,焦虑、抑郁通过躯体症状对生活质量有间接影响(均P<0.05)。结论 主动脉夹层术后患者生活质量处于中等偏上水平,应早期对主动脉夹层术后患者的心理状况与躯体症状进行动态评估与监测,及时进行心理干预和症状管理,以改善其生活质量。  相似文献   
6.
BackgroundDue to the limited number of landmark structures, it is difficult to standardize the surgical procedures for advanced esophagogastric junction cancer such as Ivor Lewis esophagectomy that require transhiatal lower mediastinal lymph node dissection (TH-LMND). We demonstrate an easily reproducible procedure for TH-LMND, wherein four body cavities, namely, the abdominal cavity, infracardiac bursa (ICB), and left and right thoracic cavities are interconnected.MethodsFirst, the dissection between the right crus and the esophagus was used to connect the abdominal cavity to the ICB — a lower mediastinal cavity separated from the omental bursa during embryonic development [1,2]. Second, the right thoracic cavity was opened with the shortest distance by dissecting the cranial side of the ICB. The right pulmonary ligament was dissected from the right lung. Third, the dissection to the contralateral side while exposing the aorta and the pericardium connected the left and right thoracic cavities. Then, the left pulmonary ligament was dissected from the left lung. The dissected tissues, including the lymph nodes, were subsequently peeled from the esophagus.ResultsBetween April 2018 and August 2021, 14 patients underwent laparoscopic or robotic TH-LMND via the procedure above. The median time required to complete the dissection was 75 min. None of the procedures were converted to open surgery, and none of the patients experienced intraoperative complications such as pericardial injury, lung injury, or massive bleeding.ConclusionThe surgical concept of interconnecting four body cavities made the procedure more accessible and reproducible while achieving en bloc TH-LMND.  相似文献   
7.
ObjectiveTo investigate the clinical value of endoscopic signs for diagnosing Helicobacter pylori(Hp) infection by white light endoscopy.  相似文献   
8.
9.
10.
《Clinical breast cancer》2020,20(5):390-394
BackgroundBreast cancer patients with triple-negative or human epidermal growth factor receptor 2 (HER2)-overexpressing phenotypes are recommended to receive chemotherapy for primary tumors greater than 1 cm regardless of nodal status. Neoadjuvant chemotherapy may eradicate subclinical nodal metastases and reduce the extent of axillary surgery performed.Patients and MethodsA query of the National Cancer Database Participant User File was performed for new cases of female breast cancer from 2012 to 2015. Inclusion criteria were clinical N0 status, receipt of chemotherapy, and receipt of axillary surgery. Exclusions included hormone-positive/HER2-negative tumors and/or distant metastatic disease. Subjects were divided into groups by receipt of neoadjuvant or adjuvant chemotherapy. The primary end point was the extent of axillary surgery, defined as sentinel lymph node biopsy alone or axillary lymph node dissection (ALND). Subgroup analyses were performed on the basis of tumor phenotype and surgery of the primary site.ResultsA total of 66,771 female patients were included, 15,967 of whom underwent neoadjuvant chemotherapy. ALND rates were higher in patients who received adjuvant chemotherapy (30.6% vs. 28.8%, P < .001). Among tumor phenotypes, the extent of axillary surgery was reduced most significantly for hormone-negative, HER2-positive disease (30.0% vs. 25.8%, P < .001). ALND rates were more substantially reduced for patients who underwent mastectomy (41.3% vs. 36.1%, P < .001) compared to partial mastectomy (21.8% vs. 20.1%, P = .002). Adjuvant chemotherapy was an independent predictor of ALND (odds ratio, 1.26; 95% confidence interval, 1.19-1.33).ConclusionNeoadjuvant chemotherapy reduces the extent of axillary surgery in clinically node-negative, nonluminal breast cancers.  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