全文获取类型
收费全文 | 23246篇 |
免费 | 2437篇 |
国内免费 | 1551篇 |
专业分类
耳鼻咽喉 | 163篇 |
儿科学 | 361篇 |
妇产科学 | 251篇 |
基础医学 | 2917篇 |
口腔科学 | 347篇 |
临床医学 | 3142篇 |
内科学 | 3606篇 |
皮肤病学 | 214篇 |
神经病学 | 1546篇 |
特种医学 | 991篇 |
外国民族医学 | 20篇 |
外科学 | 2106篇 |
综合类 | 3597篇 |
现状与发展 | 6篇 |
一般理论 | 5篇 |
预防医学 | 1414篇 |
眼科学 | 811篇 |
药学 | 2512篇 |
34篇 | |
中国医学 | 1409篇 |
肿瘤学 | 1782篇 |
出版年
2024年 | 98篇 |
2023年 | 399篇 |
2022年 | 1071篇 |
2021年 | 1325篇 |
2020年 | 990篇 |
2019年 | 870篇 |
2018年 | 910篇 |
2017年 | 736篇 |
2016年 | 734篇 |
2015年 | 1013篇 |
2014年 | 1391篇 |
2013年 | 1125篇 |
2012年 | 1670篇 |
2011年 | 1745篇 |
2010年 | 1071篇 |
2009年 | 911篇 |
2008年 | 1123篇 |
2007年 | 1098篇 |
2006年 | 1180篇 |
2005年 | 1069篇 |
2004年 | 683篇 |
2003年 | 727篇 |
2002年 | 603篇 |
2001年 | 463篇 |
2000年 | 586篇 |
1999年 | 561篇 |
1998年 | 371篇 |
1997年 | 376篇 |
1996年 | 269篇 |
1995年 | 253篇 |
1994年 | 211篇 |
1993年 | 131篇 |
1992年 | 205篇 |
1991年 | 148篇 |
1990年 | 131篇 |
1989年 | 101篇 |
1988年 | 109篇 |
1987年 | 98篇 |
1986年 | 96篇 |
1985年 | 77篇 |
1984年 | 33篇 |
1983年 | 29篇 |
1979年 | 35篇 |
1974年 | 35篇 |
1973年 | 27篇 |
1970年 | 23篇 |
1969年 | 31篇 |
1968年 | 23篇 |
1967年 | 29篇 |
1966年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
药流与负压吸宫法的效果和可接受性研究 总被引:5,自引:1,他引:4
研究的目的:比较RU486/Cytotec药物和负压吸宫术两种流产方法的效果,以及医学的和个人的可接受性.对象为通过咨询,介绍两种流产方法后,让对象自愿选择而组成.年龄在20~34岁.药物组100例,闭经35~42天,第1天口服RU486 600mg,第3天服Cytotec(PGE1)0.4mg,第17、43天回医院随访.手术组100例,闭经≤56天,负压吸宫术后第14、43天回医院随访.结果:完全流产率药物组为89%,手术组为100%.对象选择这两种流产方法的主要原因:药物组94%的人认为痛苦少,手术组的55%认为手术快、节省时间,而且手术同时可取出或放置宫内节育器(占45%).结论:RU486/Cytotec药物流产和负压吸宫术在各自适合的人群中都具有高度的可接受性.两种方法各具优缺点,不能相互取代,二者相辅相成,取长补短,将使终止妊娠的措施更为安全 相似文献
62.
According to our supposition that "humoral mechanism" plays an important role in the pathogenesis of portal hypertension due to cirrhosis, antagonists to some of humoral substances would lower the portal pressure in cirrhotic patients. Wedged hepatic venous pressure (WHVP) was used as an indicator for changes of portal pressure. Cimetidine was given intravenously to 8 cirrhotic patients, in whom an average lowering of 0.72 kPa (7.3 cm H2O) of WHVP was observed subsequently. This change was of clinical significance as compared with the previous results of splenorenal shunting operations.
相似文献
63.
64.
65.
Factors associated with breast cancer clinical trials participation and enrollment at a large academic medical center. 总被引:5,自引:0,他引:5
Michael S Simon Wei Du Lawrence Flaherty Philip A Philip Patricia Lorusso Cheryl Miree Daryn Smith Diane R Brown 《Journal of clinical oncology》2004,22(11):2046-2052
PURPOSE: The practice patterns of medical oncologists at a large National Cancer Institute Comprehensive Cancer Center in Detroit, MI were evaluated to better understand factors associated with accrual to breast cancer clinical trials. PATIENTS AND METHODS: From 1996 to 1997, physicians completed surveys on 319 of 344 newly evaluated female breast cancer patients. The 19-item survey included clinical data, whether patients were offered clinical trial (CT) participation and enrollment, and when applicable, reasons why they were not. Multivariate analyses using logistic regression were performed to evaluate predictors of an offer and enrollment. RESULTS: The patients were 57% white, 32% black, and 11% other/unknown race. One hundred six (33%) were offered participation and 36 (34%) were enrolled. In multivariate analysis, CTs were less likely offered to older women (mean age, 52 years for those offered v 57 years for those not offered; P =.0005) and black women (21% of blacks offered v 42% of whites; P =.0009). Women with stage 1 disease, poor performance status, and those who were previously diagnosed were also less likely to be offered trials. None of these factors were significant predictors of enrollment. Women were not offered trials because of ineligibility (57%), lack of available trials (41%), and noncompliance (2%). Reasons for failed enrollment included patient refusal (88%) and failed eligibility (12%). CONCLUSION: It is important for cooperative groups to design studies that will accommodate a broader spectrum of patients. Further work is needed to assess ways to improve communication about breast cancer CT participation to all eligible women. 相似文献
66.
增殖细胞核抗原在鼻咽癌中表达的定量研究 总被引:10,自引:1,他引:10
为了增加鼻咽癌的诊断和预后判定指标,应用抗增殖细胞核抗原(PCNA)单克隆抗体,采用免疫组化染色LAS-SP法及图象分析技术,对82例鼻咽鳞状细胞癌和25例鼻咽粘膜炎症组织标本进行了定量研究,并对鼻咽癌患者5年生存率与PCNA表达情况进行了相关性分析。结果:①根据PCNA阳性细胞计算的鼻咽癌细胞增殖指数与鼻咽癌的病理分级呈明显的正相关,与患者5年生存率呈明显负相关。②图像处理检测的PCNA表达量与 相似文献
67.
基础直立倾斜试验对儿童不明原因晕厥的诊断研究 总被引:35,自引:3,他引:35
为探讨基础直立倾斜试验对不明原因的晕厥患儿的诊断价值,应用直立倾斜试验(倾斜角度60度,试验持续时间45分钟)对42例不明原因的晕厥患儿进行诊断研究,并以13名正常小儿作对照。结果:基础直立倾斜试验在不明原因晕厥患儿的阳性率为67%,对照组阳性率为0。诊断敏感度、特异度及诊断价值分别为67%、100%及74%。阳性反应诱发时间为22±12分钟。在28例阳性反应患儿中,15例为血管抑制型反应,表现为血压明显下降,心率增快;3例为心脏抑制型反应,表现为心率明显下降,血压不变;10例为混合型反应,其血压、心率均明显下降。提示:基础直立倾斜试验可较好地、客观地对血管迷走性晕厥进行诊断。 相似文献
68.
尼尔雌醇作用下去势雌兔骨组织形态计量学改变 总被引:1,自引:0,他引:1
目的:评估尼尔雌醇对绝经后骨质疏松症的疗效,并探讨其机理。方法:将30只雌性新西兰兔随机分成3组(每组10只):治疗组[摘除卵巢+尼尔雌醇(每月2mg)]、模型组(摘除卵巢)和正常对照组(假手术),6个月后处死取材,并在处死前行四环素标记,VIDAS图象分析系统下作骨组织形态计量学测定。结果:治疗组的单位体积骨小梁骨量(BV/TV)、相对类骨质量(OV/BV)、成骨细胞指数(OBI)和组织水平的骨形成速率[BFR(T)]明显高于模型组和(或)正常对照组。结论:尼尔雌醇能增加成骨细胞数量,可能是一种成骨细胞募集和(或)增殖的刺激剂。 相似文献
69.
为探讨小儿咽侧间隙肿瘤的临床特征,报告4例小儿咽侧间隙肿瘤患者儿的诊治体会。结合临床提出诊断本病宜通过CT扫描,先确定肿瘤的大小和范围,再选择颈侧径路摘除肿瘤.结果治疗的4例患儿均获得了肯定的结果。并且提示手术中应保护重要的血管和神经。 相似文献
70.
头颅X线测量在阻塞性睡眠呼吸暂停综合征诊治中的意义 总被引:29,自引:1,他引:29
OBJECTIVES: To study the value of cephalometric analysis in the diagnosis, treatment option and evaluation of prognosis. METHODS: A detailed cephalometric analysis was performed using lateral X-ray films from 50 cases with obstructive sleep apnea syndrome (OSAS) and 30 age- and sex-matched controls. RESULTS: Statistical results showed that OSAS patients were different from controls in the following aspects: 1. Their uvula, soft palate and tongue were significantly enlarged. 2. The hyoid bone was displaced inferiorly and posteriorly. 3. The posterior airway space (palatopharyngeal plane) was narrow. 4. The hard palate was elongated. 5. The mandibular body was retropositioned. Fifty unselected consecutive OSAS patients(mean AHI 51.42 +/- 3.96, Medilog SAC 847, Oxford UK) underwent LAUPP using CO2 laser. Twenty-five cases were followed-up for 4-8 months. 10/25 had obtained a reduction in AHI > 50%, 15/25 had AI < 20 times. The success rate was compared with cephalomentric findings. CONCLUSION: Cephalometry has an important diagnostic and predictive value in the clinical investigation of patients suspected of having OSAS. 相似文献