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   157130篇
  免费   14974篇
  国内免费   9512篇
耳鼻咽喉   1208篇
儿科学   1965篇
妇产科学   1731篇
基础医学   23032篇
口腔科学   2694篇
临床医学   19034篇
内科学   21939篇
皮肤病学   1670篇
神经病学   7711篇
特种医学   5364篇
外国民族医学   74篇
外科学   15093篇
综合类   26238篇
现状与发展   35篇
一般理论   13篇
预防医学   10945篇
眼科学   3770篇
药学   17994篇
  135篇
中国医学   8642篇
肿瘤学   12329篇
  2024年   613篇
  2023年   2441篇
  2022年   6222篇
  2021年   7955篇
  2020年   5829篇
  2019年   5152篇
  2018年   5362篇
  2017年   4943篇
  2016年   4755篇
  2015年   6915篇
  2014年   8580篇
  2013年   8256篇
  2012年   11668篇
  2011年   12398篇
  2010年   8693篇
  2009年   7006篇
  2008年   8452篇
  2007年   8456篇
  2006年   7762篇
  2005年   7068篇
  2004年   5414篇
  2003年   5246篇
  2002年   4478篇
  2001年   3783篇
  2000年   3245篇
  1999年   2928篇
  1998年   1840篇
  1997年   1980篇
  1996年   1406篇
  1995年   1317篇
  1994年   1183篇
  1993年   817篇
  1992年   1042篇
  1991年   955篇
  1990年   859篇
  1989年   786篇
  1988年   689篇
  1987年   600篇
  1986年   572篇
  1985年   444篇
  1984年   380篇
  1983年   309篇
  1982年   274篇
  1981年   231篇
  1980年   196篇
  1979年   202篇
  1978年   192篇
  1977年   211篇
  1976年   191篇
  1974年   156篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
用视诱发电位和富里叶变换作视力客观估计   总被引:2,自引:0,他引:2  
余敏忠 《眼科学报》1997,13(2):59-61
目的:研究用图形视觉诱发电位(PVEP)和离散富里叶变换(DFT)作视力客观估计的方法。方法:检测对象为33只正常眼。用翻转频率为10次/秒,条纹张角分别为30、20、18、12、10、6、4和2弧分的垂直方波光栅图形刺激,记录相应的稳态图形视诱发电位。用离散富里叶交换提取WEP频谱中10Hz成分的幅值。以光栅条纹张角为横坐标、相应的VEP频谱幅值为纵坐标作关系曲线,取阈值附近的近似线性部分的数据点作直线回归,用外推法求得阈值和视力。结果:比较VEP所测之视力与用国际标准视力表所测之视力,可见在本研究中70%的受检眼VEP视力估计较准确。结论:用本研究中的VEP技术客观地测量视力可靠性较高。眼科学报1997;13:59~61。  相似文献   
92.
本文报道了阿昔洛韦联合胸腺肽对慢性乙型肝炎抗病毒疗效,阿昔洛韦10g,胸腺肽16mg静滴,每日一次,连续治疗2月,共治疗33例,治疗结束后,治疗组HBeAg阴转16例,阴转率5517%,HBV DNA阴转18例,阴转率5454%。对照组HBeAg阴转率952%(2/25),HBV DVA阴转率909%(1/25),两组比较有显著性差异(p<001),表明阿昔洛韦联合胸腺肽是一种有效、价廉、使用方便的抗乙型肝炎病毒药物。  相似文献   
93.
Summary The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8°, r 13°–30°) and from 33 with severe scoliosis (mean Cobb angle 46.2°, r 35°–71°). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation.  相似文献   
94.
The intraocular pressure and the anteroposterior length of the eye are of great clinical importance for the diagnosis and management, before and after surgery, of congenital glaucoma. It is well-known that normal intraocular pressure in children is different from the normal levels in adults. We performed measurements of intraocular pressure and axial length in 141 children who had been admitted for eye problems other than glaucoma. The intraocular pressures were measured with the Perkins hand-held applanation tonometer at the beginning of general anesthesia. Simultaneously, A-scan ultra-sound measurements of the axial lengths of the eyes were made. In 10 children under the age of two years, the intraocular pressure was 11.85 +/- 1.35 mmHg. In 79 children from two to seven years, the intraocular pressure was 12.80 +/- 1.73 mmHg. In 52 children from seven to 15 years, the intraocular pressure was 13.31 +/- 1.79 mmHg. The axial lengths of the eyes in children under the age of two years, from two to seven years, and from seven to 15 years, were 21.31 +/- 0.97 mm, 22.04 +/- 0.92 mm, and 23.22 +/- 1.00 mm, respectively. These results were considered to be guidelines for measuring intraocular pressure and axial length in children suspected of having congenital glaucoma. The differences of intraocular pressures stated by other authors are due to early measurement of the intraocular pressure at the beginning of general anesthesia.  相似文献   
95.
96.
97.
本文用Balb/c小鼠观察了巯亚硝基蛋白在体内产生一氧化氮的量效关系,结果发现,SNO-Hb在体内可剂量信赖地产生NO。  相似文献   
98.
用氯胺-T法125I标记眼镜蛇毒示踪液及抗眼镜蛇毒血清。小白鼠分二组,用125I-眼镜蛇毒、125I-抗眼镜蛇毒血清分别给小白鼠尾静脉注射,于注射后的不同时间测定血、颈部肌肉、肝、肺、肾、心等脏器放射性分布。结果发现:125I-眼镜蛇毒在肌肉及肝、肺等器官中于注射后2小时过高峰,在肾脏中浓度高,在脑未见放射性分布,抗眼镜蛇毒血清与眼镜蛇毒分布相似但在肌肉及肺脏有更高的分布。证明抗眼镜蛇毒血清能跟踪分布眼镜蛇毒。  相似文献   
99.
Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs of rapid variant of the dysfunction produced by acute blood loss. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998  相似文献   
100.
组织扩张术皮肤胶原的代谢改变   总被引:4,自引:0,他引:4  
李江  鲁开化 《医学争鸣》1998,19(3):307-309
目的:研究常规扩张(ITE)和持续快速扩张(CTE)对皮肤胶原代谢的影响。方法用白色小家猪制作组织扩张术动物模型,用Gordeladze法测定血清和扩张组织的羟脯氨酸(HP)含量,藻酸盐印模材膜片法测量标记区面积;光镜测量真皮厚度。结果:ITE组血清HP含量升高,0.8倍,CTE组升高1.2倍,ITE和CTE组皮肤含量与正常皮肤相同,组织中HP总量均明显升高,持续扩张皮瓣组(CTEF)术后4wk皮  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