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   7144篇
  免费   323篇
  国内免费   136篇
耳鼻咽喉   88篇
儿科学   163篇
妇产科学   87篇
基础医学   494篇
口腔科学   148篇
临床医学   852篇
内科学   541篇
皮肤病学   43篇
神经病学   632篇
特种医学   265篇
外科学   1468篇
综合类   992篇
预防医学   373篇
眼科学   66篇
药学   633篇
  9篇
中国医学   77篇
肿瘤学   672篇
  2024年   16篇
  2023年   81篇
  2022年   139篇
  2021年   230篇
  2020年   207篇
  2019年   181篇
  2018年   205篇
  2017年   195篇
  2016年   177篇
  2015年   213篇
  2014年   477篇
  2013年   494篇
  2012年   368篇
  2011年   426篇
  2010年   390篇
  2009年   364篇
  2008年   350篇
  2007年   364篇
  2006年   322篇
  2005年   288篇
  2004年   276篇
  2003年   230篇
  2002年   180篇
  2001年   177篇
  2000年   109篇
  1999年   121篇
  1998年   103篇
  1997年   95篇
  1996年   76篇
  1995年   55篇
  1994年   68篇
  1993年   48篇
  1992年   54篇
  1991年   44篇
  1990年   32篇
  1989年   38篇
  1988年   26篇
  1987年   40篇
  1986年   40篇
  1985年   57篇
  1984年   41篇
  1983年   19篇
  1982年   35篇
  1981年   30篇
  1980年   40篇
  1979年   18篇
  1978年   11篇
  1977年   13篇
  1974年   8篇
  1973年   8篇
排序方式: 共有7603条查询结果,搜索用时 31 毫秒
1.
IntroductionWith the increasing reliance on targeted therapies and immunotherapy, no standard management strategy is today available for the treatment of locally, distant, or both renal cell carcinoma (RCC) recurrences, and their surgical treatment seems to play a crucial role. We report the 20-year experience of our center evaluating the short- and long-term outcomes of patients undergone surgical resection of RCC recurrences, and the possible role of repeated surgical resections of RCC recurrences.Materials and methodsFrom January 1999 to January 2019, 40 patients underwent surgical resection of isolated locally recurrent RCC (iLR-RCC-group), locally recurrent RCC associated with the presence of distant recurrence (LR-DR-RCC-group), and distant-only recurrent RCC (DR-RCC-group). Data regarding pre-, intra-, post-operative course, and follow-up, prospectively collected in an institutional database, were retrospectively analyzed and compared.ResultsiLR-RCC-group was composed of 9 patients, LR-DR-RCC-group of 6 patients, and DR-RCC-group of 25 patients. The recurrence rate was 55.6% (5/9 patients) in iLR-RCC-group, 50% (3/6 patients) in LR-DR-RCC-group, and 44% (11/25) patients in DR-RCC-group, p = 0.830. 3/5 (60%) patients in iLR-RCC-group, 2/3 (66.7%) patients in LR-DR-RCC-group, and 7/11 (63.6%) patients in DR-RCC group underwent to almost one further local treatments of their recurrences, respectively (p = 0.981). No differences in the mean disease-free survival (p = 0.384), overall survival (OS) (p = 0.881), and cancer-specific survival (p = 0.265) were reported between the three groups. In DR-RCC-group, patients who underwent further local treatments of new recurrences presented a longer OS: 150.7 versus 66.5 months (p = 0.004).ConclusionsA surgical resection of RCC recurrences should be always taken in consideration, also in metastatic patients and/or in those who have already undergone surgery of previous RCC recurrence, whenever radicality is still possible, because this approach may offer a potentially long survival.  相似文献   
2.
《Vaccine》2021,39(35):4964-4972
This article applies a qualitative approach to the 2017 dengue vaccine controversy involving Sanofi Pasteur’s Dengvaxia to understand vaccine hesitancy and related anxieties in contemporary Philippines. Through a multisited project that investigated the health aspirations and lived experiences of low- and middle-income Filipinos across urban and rural Philippines, this article distills the perspectives of both ordinary community members and health workers in local and national capacities regarding the controversy—and how it altered their perceptions toward vaccines, health care, and government. Our study reveals widespread mistrust and fear in the communities toward both the state and health institutions following the controversy, with frontline health workers bearing the brunt of the communities’ apprehensions, and the media partly responsible in fomenting these fears. Given the repetitive nature of health and vaccine controversies, this article suggests the importance of responsible journalism, well-calibrated crisis communications, and a people-centered health paradigm that involves exploring local contexts of vaccine hesitancy and mining people’s lived experiences in tackling present and future health crises—especially now in the advent of COVID-19 vaccinations.  相似文献   
3.
严志 《中外医疗》2016,(14):29-31
目的:探究眼睑分裂痣的不同手术方法和治疗效果。方法随机选取该院在2014年1月—2015年12月收治的60例需要进行眼睑分裂痣手术治疗的患者作为观察对象,将其按照抽签法随机分为A组(n=20)、B组(n=20)和C组(n=20),A组患者采用全厚皮片移植术;B组患者采用转移或推进皮瓣术;C组患者采用皮片移植+皮瓣转移术。首先对3组患者的治疗效果进行观察,然后比较3组患者在治疗后的不良反应发生情况,对比不良反应的发生率。结果3组患者的治疗效果均较好,所有患者的上伤口在1期即全部愈合,未出现明显的睑缘切痕;A组患者中,出现不良反应的患者有1例,占5.0%。B组中,无患者出现不良反应,不良反应发生率为0.0%。C组中,出现不良反应的患者有1例,占5.0%。3组患者之间差异无统计学意义(P﹥0.05)。结论治疗眼睑分裂痣的方法较多,全厚皮片移植术、转移或推进皮瓣术以及皮片移植+皮瓣转移术均有较好的效果,患者无明显的不良反应,并且痊愈的效果较好,手术的操作也较为简便易行,具有较高的安全性和可行性,值得临床推广。  相似文献   
4.
Retinal fundus photographs are employed as standard diagnostic tools in ophthalmology. Serial photographs of the flow of fluorescein and indocyanine green (ICG) dye are used to determine the areas of the retinal lesions. For objective measurements of features, the registration of the images is a necessity. In this paper, we employ optimization techniques for registration with the help of 2-parameter translational motion model of retinal angiograms, based on non-linear pre-processing (Wiener filtering and morphological gradient) and computation of the similarity criteria for the alignment of the two gradient images for any given rigid transformation. The optimization methods are effectively employed to minimize the similarity criterion.

The presence of noise, the variations in the background and the temporal variation of the fluorescence level pose serious problems in obtaining a robust registration of the retinal images. Moreover, local search strategies are not robust in the case of ICG angiograms, even if one uses a multiresolution approach.

The present work makes a systematic comparison of different optimization techniques, namely the minimization method derived from the optical flow formulation, the Nelder-Mead local search and the HCIAC ant colony metaheuristic, each optimizing a similarity criterion for the gradient images. The impact of the resolution and median filtering of gradient image is studied and the robustness of the approaches is tested through experimental studies, performed on macular fluorescein and ICG angiographies.

Our proposed optimization techniques have shown interesting results especially for high resolution difficult registration problems. Moreover, this approach seems promising for affine (6-parameter motion model) or elastical registrations.  相似文献   

5.
深低温对全脑缺血性损伤的保护作用   总被引:2,自引:0,他引:2  
国际上把低温划分为轻度低温(33~35℃),中度低温 (28~32℃),深度低温(17~27℃)和超深度低温(2~16℃)。低温已经被大量动物试验和临床实践证实具有脑保护作用,但同时也存在心律失常,凝血功能障碍,免疫抑制等全身多系统副作用,产且温度越低,副作用越明显。日前国内外已经有大量的试验证实深低温对全脑缺血的脑保护作用,它能明显增加脑组织对缺血的耐受性,本文将就深低温对全脑缺血性损  相似文献   
6.
目的:应用超声多普勒探讨动脉粥样硬化(AS)与局部血流动力学的相关性。方法:对420例发生AS患者升主动脉、颈总动脉、颈内动脉、髂总动脉、股动脉的斑块分布情况进行统计、分析、对照。结果:420例AS患者各部斑块发生率分别为颈动脉窦部85.12%,动脉分叉前(腹主动脉、股动脉下端)45%,动脉分叉后(颈内、髂总、股深动脉起始)内、外侧壁分别为51.98%、53.45%,动脉平直区(颈总、股动脉干)34.58%,升主动脉为1.4%(6/420);升主动脉内径增宽和运动幅度减低发生率为90.71%(381/420)。各观察区与动脉平直区比较AS发生率有显著差异(P<0.001)。结论:AS斑块分布有明显的倾向性,认为局部血流动力学异常是导致AS发生的重要因素。  相似文献   
7.
To compare pulmonary effects, postoperative pain and fatigue, morbidity, patient satisfaction, and cost of different anesthetic techniques for inguinal hernia repair, 50 patients were randomized to local and general anesthesia groups (LA and GA). All patients received the same premedications and the same postoperative analgesic regimen. The standardized postoperative analgesic, intramuscular pyroxicam 20 mg, was given to all patients in the recovery room and an additional 20 mg on the same day was given as requested by each patient. Pulmonary function studies and arterial blood gas analysis were performed 1 h prior to the operation and at the postoperative 8th and 24th hours. All patients underwent Lichtenstein's tension-free hernioplasty. Postoperative pain and fatigue were registered 8 h and 24 h after the operation. A questionnaire was filled out by the patients, and they were asked to give grades for the general comfort of the anesthesia and the surgical procedure (1=worst, 10=best). Postoperative pulmonary function tests were significantly poorer in the GA group both on 8th- and 24th-hour measurements (P<0.05). Patients who underwent LA had significantly lower PCO2 and higher PO2 at the postoperative 8th hour (P<0.05). Mean postoperative pain and fatigue scores revealed a significant difference in favor of local anesthesia at only the 8th hour (P<0.05). There were two complications, one in each group (a hematoma in LA and a urinary retention in GA). Patient satisfaction grades were not different in the two groups. We conclude that LA in inguinal hernia repair does not adversely affect pulmonary functions, patients feel less pain, and patient satisfaction is comparable to that with GA. Electronic Publication  相似文献   
8.
目的:研究轻度高温、亚低温对大鼠脑缺血再灌注损伤组织兴奋性氨基酸(EAA)与氧自由基的相互关系及病理损伤程度的影响。方法:60只Wistar大鼠按不同脑温条件随机分为生化组(n=28)和病理组(n=32),采用改良Nagasawa局灶脑缺血再灌注模型,观察脑缺血再灌注损伤组织谷氨酸(Glu),超氧化物歧化酶(SOD)、丙二醛(MDA)的变化及光镜,电镜下的病理变化。结果:轻度高温明显加重常温脑缺血再灌注损伤组织Glu、MDA的升高(P<0.01)及SOD的下降(P<0.05),加重常温脑缺血再灌注组织病理损伤程度,亚低温的作用则相反,结论:轻度高温可能通过同时促进EAA合成,释放和氧自由基生成系统活化,造成大鼠脑缺血再灌注损组织损伤加重;亚低温可能通过同时抑制EAA合成,释放和氧自由基生成系统活化,减轻大鼠脑缺血再灌注组织损伤程度,对大鼠脑缺血再灌注损伤组织起保护作用。  相似文献   
9.
10.
Most of the papers published on spigelian hernia are either case reports or small retrospective series. In this prospective multicenter study, we aimed to outline the specific features of spigelian hernias and patients’ characteristics more clearly. Surgeons enrolled patients to be entered into the database as they diagnosed and treated the hernias at will. The baseline and surgical outcome parameters were noted in each patient. A painful mass was the main presenting complaint in half of 34 patients. Accurate preoperative diagnosis was possible in 31 patients. Open intraperitoneal mesh repair was the preferred technique. The mean hospital stay and time until return to normal daily activities were 4.1 and 15.6 days. Although a rare condition, diagnosis of a spigelian hernia is not difficult once remembered. Its surgical repair seems to cause few complications and is very well tolerated by the patient.  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