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   33878篇
  免费   3303篇
  国内免费   2328篇
耳鼻咽喉   326篇
儿科学   429篇
妇产科学   359篇
基础医学   3747篇
口腔科学   590篇
临床医学   4349篇
内科学   4901篇
皮肤病学   345篇
神经病学   1661篇
特种医学   1497篇
外国民族医学   16篇
外科学   3902篇
综合类   5828篇
现状与发展   7篇
一般理论   3篇
预防医学   2190篇
眼科学   733篇
药学   3669篇
  36篇
中国医学   1936篇
肿瘤学   2985篇
  2024年   126篇
  2023年   534篇
  2022年   1353篇
  2021年   1673篇
  2020年   1274篇
  2019年   1085篇
  2018年   1144篇
  2017年   1078篇
  2016年   1078篇
  2015年   1520篇
  2014年   1911篇
  2013年   1703篇
  2012年   2266篇
  2011年   2645篇
  2010年   1705篇
  2009年   1348篇
  2008年   1715篇
  2007年   1769篇
  2006年   1736篇
  2005年   1640篇
  2004年   1250篇
  2003年   1253篇
  2002年   1154篇
  2001年   966篇
  2000年   869篇
  1999年   838篇
  1998年   497篇
  1997年   548篇
  1996年   372篇
  1995年   328篇
  1994年   259篇
  1993年   206篇
  1992年   239篇
  1991年   228篇
  1990年   196篇
  1989年   173篇
  1988年   139篇
  1987年   145篇
  1986年   126篇
  1985年   77篇
  1984年   50篇
  1983年   28篇
  1982年   17篇
  1981年   18篇
  1980年   25篇
  1979年   45篇
  1978年   22篇
  1976年   12篇
  1975年   18篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
In January and again in April 1985, a 30-year old woman received 150 mg injections of Depo-Provera for contraception. 3 days after the 2nd injection, she experienced blurred vision in both eyes and was diagnosed as having bilateral papilledema. Her vision improved after treatment with vitamin B1 and other drugs. But optic atrophy of the right eye and papilledema of the left eye remained. In July 1985, after an injection with Depo-Provera, her vision again worsened. The woman received no more Depo-Provera after this time. In early 1987, she was referred to Beijing's Tong Ren Hospital, where she was diagnosed as having bilateral ischemic papillopathy and optic atrophy. There have been few documented cases in medical literature of ocular complications related to use of contraceptives. In 1981, Petursson et al. reported a case of macula edema resulting from oral contraceptives. In animal studies, oral contraceptives have been linked to papilledema and retinal vein obstruction. The case reported here is the 1st to link use of Depo- Provera with ocular complications.  相似文献   
72.
通过对冶金、锻造、铸造、陶瓷、纺织、印染、铁路、航运等行业的16个作业环境热环境参数和工人生理反应关系的调查,对现行的高温作业分级标准不足之处提出了一些看法,并认为IS0提出的热环境下机体反应的阈限值对我国亦是适宜的。经统计学分析发现,作业环境的计算温度和工人平均体温之间有明显相关(r=0.86)。不同气温下464名工人的主观感觉调查表明,35℃时100%的工人都有热或很热的感觉。  相似文献   
73.
永久性结肠造口术后不同患者的心理护理   总被引:20,自引:0,他引:20  
付佳 《医学争鸣》2005,26(13):1223-1223
1临床资料 我科1998-03/2003-03共做永久性结肠造口术39(男22,女17)例,年龄42~71岁. 39例患者均表现出不同程度的心理问题. 我们根据性别、年龄的不同,针对男性和女性患者、中年和老年患者的心理问题做一些比较,找出共性问题及差别,分别做出了心理分析及术后心理指导.  相似文献   
74.
双生子屈光状态的研究   总被引:4,自引:0,他引:4  
  相似文献   
75.
本实验表明,猕猴高脂造型22—28个月,其大脑中动脉(Middle Cerebral Artery:MCA)内皮发生水肿、细胞间隙变宽,局部破裂等改变,中膜平滑肌细胞增生、迁移。老年高脂组病损程度较重,且中央支也表现出类似改变。结果提示,高血脂可以引起脑动脉硬化性改变,且病损程度与年龄因素密切相关。  相似文献   
76.
It has been shown that ultrasonographic measurements can be used to predict body composition in adults. The purpose of this study was to assess the relationship between ultrasonograph and caliper (SKF) measurements of subcutaneous adipose tissue thickness in athletic Caucasian (English, E) and Asian (Chinese, C) men against estimates of body composition determined from hydrodensitometry (HYD). The usefulness of a proposed ultrasonographic method of estimating lean and fat proportions in the upper and lower limbs was also evaluated as a potential method of predicting body composition. Ultrasonography (US) was used to measure adipose and skin thickness at the following sites: biceps, triceps, subscapular, suprailiac, abdominal, pectoral, thigh and calf. Caliper measurements were also made at the above sites. Subcutaneous fat thickness and segmental radius were measured directly from the display screen of the ultrasonic scanner (Aloka 500 SD). By applying the geometry of a cone, the proximal and distal radii of the upper arm and upper leg were used to calculate the proportionate volumes of adipose tissue. The best correlations for US and SKF were obtained at the quadriceps, subscapular and pectoral sites for E (r = 0.96, 0.93 and 0.90, respectively) and at the quadriceps, calf and abdominal sites for C (r = 0.90, 0.81 and 0.75, respectively). The best ultrasonographic predictor of the percentage fat in both groups was the percentage adipose tissue volume in the upper leg (r = 0.83 and 0.79 for C and E, respectively). Stepwise multiple regression analysis indicated that the prediction of percentage fat was improved by the addition of the ultrasonographic abdomen measurement in both groups: Chinese sample: %fat = %fat(leg) (0.491) + US abdomen (0.337) + 0.95 ( R = 0.89, s.e.e. = 1.9%); English sample: %fat = %fat(leg) (0.435) + US abdomen (0.230) - 0.765 ( R = 0.80, s.e.e. = 3.6%). It is concluded that ultrasonographic measurements of subcutaneous adipose tissue and volumetric assessment of percentage adipose tissue in the thigh are useful estimates of body composition in athletic English and Chinese males.  相似文献   
77.
近年来,对护理伦理学的研究已日渐增多,护理伦理学已列入护理的正规教程,但时于基层医院护理队伍伦理道德素质状况的研究甚少,县级医院面对的是占中国80%的农村和城镇居民,其服务对象不同于大医院,也不同于村、镇卫生院。基于上述原因,本问卷调查目的在于丁解县级医院护理队伍伦理道德素质教育的状况。以及护士所面对的冲突和困难,以加强和改善护理队伍的素质建设,提高护理工作质量。  相似文献   
78.
杨淑玲  毛乾国  傅群芳 《护理研究》2006,20(34):3171-3172
报道了应用计算机对感染内科门诊干扰素治疗慢性乙型病毒性肝炎病人的一般资料、干扰素治疗方案、干扰素治疗效果、干扰素副反应、每次复查的生化结果、随访的时间等项目建立数据库,设计程序进行管理。微机能准确地储存资料,方便医护人员对门诊干扰素治疗病人进行及时、有效的治疗和管理,促进病人的健康,提高医护人员的科学管理和社区保健的能力。  相似文献   
79.
BACKGROUND AND PURPOSE: Fluorine-18-2-deoxy-D-glucose (18F-FDG) has been used in the clinic as a diagnostic radiotracer for monitoring many kinds of tumors, but its value for monitoring fibrosarcoma is not well established. METHODS: In this study, the uptake of 18F-FDG in a fibrosarcoma-bearing mouse model was evaluated using the high resolution positron emission tomography (PET) system microPET. Tumor cells were implanted in 3 FVB/N mice, and static microPET scanning was performed on day 1, 7, 12 and 15 after implantation. A dynamic microPET image was scanned on day 12 to determine the 18F-FDG uptake in 3 other tumor-bearing mice. Time-activity curves were plotted by drawing regions of interest in the tumor, liver, kidneys and muscles. The mice were sacrificed after dynamic microPET imaging and whole-body autoradiography (WBAR) was performed. For biodistribution study, 9 tumor-bearing mice, 3 per experimental group, were studied at 3 time points and the results were compared with the static microPET images. RESULTS: MicroPET images suggested that 18F-FDG could be used to monitor the growth of tumors 7 days after implantation. Dynamic scans of 18F-FDG uptake reached a plateau in the tumor after 20 minutes on day 12 after implantation. Both microPET and WBAR revealed evidence of tumor necrosis. The results of biodistribution and WBAR agreed with those from microPET images. CONCLUSION: MicroPET was useful for monitoring the growth of fibrosarcoma and determination of the maximal uptake time point of 18F-FDG in tumors in this tumor-bearing mouse model.  相似文献   
80.
茴三硫治疗慢性肝损害北京地区多中心临床研究   总被引:1,自引:0,他引:1  
目的:观察茴三硫对慢性病毒性肝炎、药物性肝病、酒精性肝病、瘀胆性肝病等的保肝、利胆和解毒的作用。方法:本研究是一项随机对照的多中心临床研究。按病例选择标准将人选病例随机分成两组,实验组(茴三硫组,70例)给予茴三硫25mg,tid;对照组(硫普罗宁组,36例)给予凯西来1片,tid;两组疗程均为8周。根据两组病人治疗后症状改善及肝功能恢复情况的判定标准,来评估两组药物的显效率、有效率和总有效率。结果:茴三硫组的显效率、有效率和总有效率分别为52.9%、27.1%和80%,硫普罗宁组的显效率、有效率和总有效率分别为55.6%、27.8%和83.3%,治疗前后两组的各症状及肝功能改善率基本相同,两组间无显没差异(P>0.05),两组均未发生明显不良反应。结论:茴三硫治疗慢性病毒性肝炎、药物性肝炎等馒性肝损害,可以明显减轻患症状,改善肝功能,其疗效与硫普罗宁效果相近,临床观察无明显不良反应。  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