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   65172篇
  免费   5669篇
  国内免费   1968篇
耳鼻咽喉   469篇
儿科学   1331篇
妇产科学   2339篇
基础医学   6990篇
口腔科学   1285篇
临床医学   6341篇
内科学   6104篇
皮肤病学   838篇
神经病学   4371篇
特种医学   1680篇
外国民族医学   7篇
外科学   4583篇
综合类   10727篇
现状与发展   3篇
一般理论   13篇
预防医学   6189篇
眼科学   1706篇
药学   7613篇
  88篇
中国医学   7453篇
肿瘤学   2679篇
  2024年   157篇
  2023年   1080篇
  2022年   1497篇
  2021年   2674篇
  2020年   2616篇
  2019年   2455篇
  2018年   2140篇
  2017年   2216篇
  2016年   2182篇
  2015年   2055篇
  2014年   3971篇
  2013年   4900篇
  2012年   3927篇
  2011年   4394篇
  2010年   3487篇
  2009年   3003篇
  2008年   2886篇
  2007年   2899篇
  2006年   2545篇
  2005年   2231篇
  2004年   1903篇
  2003年   1871篇
  2002年   1422篇
  2001年   1359篇
  2000年   1106篇
  1999年   1051篇
  1998年   906篇
  1997年   907篇
  1996年   820篇
  1995年   790篇
  1994年   657篇
  1993年   564篇
  1992年   522篇
  1991年   466篇
  1990年   481篇
  1989年   410篇
  1988年   298篇
  1987年   265篇
  1986年   328篇
  1985年   444篇
  1984年   432篇
  1983年   263篇
  1982年   338篇
  1981年   274篇
  1980年   292篇
  1979年   218篇
  1978年   185篇
  1977年   170篇
  1976年   165篇
  1975年   117篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
不寐,现代医学称睡眠障碍,是一种临床常见病和多发病,本病发病原因尚不明确,通常不伴明显器质性病变,病人自觉症状重,西医尚无明确的治愈方法。祖国医学很早就认识到本病,积累了丰富的经验。刘中勇教授在古人的基础上提出从"气血瘀滞"的角度论治不寐,临床取得较好疗效,本文将从病因病机、理论探析、辨证论治三个方面介绍其相关经验,供同行参考。  相似文献   
52.
肌萎缩侧索硬化症是一种病因不清的致死性神经系统罕见病,临床表现为进行性加重的肌无力、肌肉萎缩及延髓麻痹,最终累及呼吸肌致呼吸衰竭而死亡。顾锡镇教授从脾肾论治,运用健脾补肾法治疗该病在延缓疾病进展与改善生活质量方面取得了一定疗效。文章总结了顾教授辨治肌萎缩侧索硬化症的临床经验,并例举1个典型医案加以佐证。  相似文献   
53.
功能性便秘的发生严重困扰着现代人群,进而影响人们的生活质量。杜长海名老中医认为功能性便秘究其内因为大肠传导失常,外因乃现代人的生活方式、紧张的生活氛围等等,因此杜老结合自己数十年的临床经验,根据中医辨证总结出临床常用药对,对有效治疗功能性便秘进行了经验总结。  相似文献   
54.
PurposeTo investigate dynamic variables obtained from retrospective computed tomography angiography for ability to predict thoracic endovascular aortic repair (TEVAR) outcomes in patients with complicated type B aortic dissection (cTBAD).Materials and MethodsSeventy-nine patients with cTBAD who received TEVAR from March 2009 to June 2018 were retrospectively enrolled. Relative true lumen area (r-TLA) was computed at the level of tracheal bifurcation every 5% of all R-R intervals. Parameters that reflect the state of intimal motion were evaluated, including difference between maximum and minimum r-TLA (D-TLA) and true lumen collapse. The endpoints comprised early (≤ 30 days) and late (> 30 days) outcomes after intervention.ResultsOverall early mortality rate was 13.9% (11/79), and early adverse events rate was 24.1% (19/79). Patients who received TEVAR within 2 days of symptom onset demonstrated the worst outcomes. A longer time of r-TLA < 25% in 1 cardiac cycle (P = .049) and larger D-TLA (P < .001) were correlated to an increased early death. In addition, D-TLA was an independent predictor of early mortality. Area under the curve of D-TLA was 0.849 (95% confidence interval 0.730–0.967) for predicting early mortality and 0.742 (95% CI 0.611–0.873) for predicting early adverse events. Survival and event-free survival rates during follow-up were decreased in the D-TLA > 21.5% group compared with the D-TLA ≤ 21.5% group (all P < .001).ConclusionsLarger D-TLA is correlated with worse postoperative outcomes and might be a crucial parameter for future risk stratification in patients with cTBAD.  相似文献   
55.
56.
57.
目的探讨预见习在精神病教学中的作用。方法选取120名本科学生,随机分为预见习组(n=60)和对照组(n=60)。预见习组在学习精神病学理论课程前一学期开始实施带教老师带领学生预见习、见习、实习全程教学,对比两组学生实践操作、理论知识成绩和学生满意度。结果干预后,导师制预见习组实践操作和理论知识成绩显著高于对照组(P<0.05)。导师制预见习组学生满意度显著高于对照组(P<0.05)。结论预见习教学有助于学生全面发展,提高精神病学教学水平。  相似文献   
58.
《Clinical neurophysiology》2019,130(9):1562-1569
ObjectiveConventional deep brain stimulation (DBS) systems with ring-shaped leads generate spherical electrical fields. In contrast, novel directional leads use segmented electrodes. Aim of this study was to quantify the impedance variations over time in subjects with the directional Cartesia-Boston® system.MethodsImpedance records, programming settings, and clinical data of 11 consecutive Parkinsonian patients implanted with DBS directional leads in two Italian centers (Udine and Vicenza) were retrospectively evaluated. Data were collected before starting stimulation (in the operating room and at days 5 and 40) and after switching stimulation on at the successive follow-up visits (1, 6 and 12 months).ResultsDirectional leads have significantly higher impedance than ring leads. Stimulated contacts had always lower impedance compared to non-stimulated contacts. Before DBS-on, all contacts had higher impedance in the operating room, with an initial decrease five days post-surgery and a subsequent increase at day 40, more evident for directional contacts. The impedance of directional leads increased post-implantation at 1 and 6 months with a plateau at 12 months.ConclusionsThere was a significant difference between the directional and ring leads at baseline (before activation of DBS) and during follow-up (chronic DBS).SignificanceOur study reveals new information about the impedance of segmented electrodes that is useful for patient management during the initial test period, as well as during long-term DBS follow-up.  相似文献   
59.
Sessile serrated adenoma/polyps (SSA/Ps) are early precursor lesions in the serrated neoplasia pathway, which results in BRAF‐mutated colorectal carcinomas with not only high levels of microsatellite instability but also microsatellite stable. SSA/Ps with advanced histology, including cytological dysplasia or minimally invasive carcinomas, are important lesions because SSA/Ps are considered major contributors to “interval cancers” and these lesions can rapidly become dysplastic or invasive carcinomas. Clinicopathologically, SSA/Ps with dysplasia or invasive carcinoma were associated with advanced age, female sex, and proximal colon. Although SSA/Ps with submucosal invasive carcinoma were smaller and invaded less deeply into the submucosal layer than conventional tubular adenomas with submucosal invasive carcinoma, SSA/Ps with submucosal invasive carcinoma frequently had a mucinous component and exhibited a higher potential for lymphatic invasion and lymph node metastasis. In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, may help accurately diagnose SSA/Ps with advanced histology. Removal of SSA/Ps with dysplasia or invasive carcinoma was recommended. Endoscopic treatment such as endoscopic mucosal resection or endoscopic submucosal dissection is useful for those lesions. However, surgical resection with lymph node dissection might be indicated when SSA/Ps with invasive carcinoma are endoscopically suspected, because these have the high risk of lymph node metastasis. Greater awareness may promote further research into improving the detection, recognition, and complete resection rates of SSA/Ps with dysplasia or invasive carcinoma and reduce the interval cancer rates.  相似文献   
60.
目的:研究Visumax飞秒激光辅助的准分子激光原位角膜磨镶术(LASIK)术中不透明气泡层(OBL)产生的类型、相关影响因素及其临床意义。方法:回顾性分析。收集2016 年7 月1 日至8 月20 日在南京医科大学附属眼科医院行飞秒LASIK的患者154 例(300 眼)的临床资料,等效球镜度为(-5.88±1.51)D。飞秒激光采用Zeiss公司 Visumax飞秒激光仪,将术中产生的OBL分为瓣外OBL、瓣内快速OBL和瓣内慢速OBL。300 眼按角膜曲率平均K值分为A组(<42 D)、B组(42~46 D)和C组(>46 D);按角膜瓣的厚度分为D组(100 μm)、E组(110 μm)和F组(120 μm);按角膜厚度分为G组(<500 μm)、H组(500~540 μm)和I组(>540 μm)。统计不同角膜曲率、角膜瓣厚度、角膜厚度情况下3 种OBL产生的比例,并采用多元Logistic回归模型进行统计分析。结果:300 眼均发生OBL。以瓣外OBL作为参照,角膜瓣越薄,越容易出现瓣内快速OBL(r=-0.719,P=0.034)和瓣内慢速OBL(r=-0.875,P=0.044)。以瓣内慢速OBL作为参照,角膜曲率越高,越容易出现瓣内快速OBL(r=0.923,P=0.046);角膜瓣越厚,越容易出现瓣外OBL(r=0.897,P=0.044)。结论:OBL的产生与角膜曲率、角膜瓣厚度、角膜厚度均存在一定的相关性,但瓣外OBL、瓣内快速OBL和瓣内慢速OBL对Visumax飞秒激光辅助的LASIK术后视觉质量的影响及远期疗效仍有待进一步观察研究。  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