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   167篇
  免费   6篇
儿科学   7篇
妇产科学   2篇
基础医学   36篇
口腔科学   5篇
临床医学   16篇
内科学   17篇
神经病学   2篇
特种医学   10篇
外科学   17篇
综合类   3篇
预防医学   8篇
眼科学   2篇
药学   43篇
肿瘤学   5篇
  2021年   4篇
  2019年   3篇
  2018年   4篇
  2017年   4篇
  2016年   4篇
  2015年   4篇
  2014年   2篇
  2013年   2篇
  2012年   4篇
  2011年   2篇
  2010年   3篇
  2008年   4篇
  2007年   2篇
  2006年   2篇
  2005年   5篇
  2004年   3篇
  2003年   10篇
  2002年   4篇
  2000年   6篇
  1999年   7篇
  1998年   10篇
  1997年   3篇
  1996年   3篇
  1995年   3篇
  1994年   1篇
  1993年   4篇
  1992年   3篇
  1991年   7篇
  1990年   4篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   4篇
  1984年   3篇
  1983年   1篇
  1982年   2篇
  1980年   1篇
  1978年   2篇
  1976年   4篇
  1975年   1篇
  1974年   2篇
  1973年   2篇
  1972年   1篇
  1971年   1篇
  1970年   3篇
  1968年   2篇
  1967年   4篇
  1966年   3篇
  1965年   3篇
排序方式: 共有173条查询结果,搜索用时 15 毫秒
1.
2.
3.
Experiments on resting hepatocytes with inactive c-fos gene and active albumin gene. We revealed that DNA of the transcribed gene is less susceptible to the influence of endogenous Ca2+/Mg(2+)-dependent DNases in matrix-associated and highly soluble chromatin fractions. In the fraction of low soluble chromatin active gene was more accessible for DNases. Our results indicate that activity of endogenous DNases can change in the transcribed gene locus.  相似文献   
4.
5.
6.
7.
8.
9.
10.
Birth defect-related demise is mainly due to congenital heart defects. In the earlier stage of pregnancy, fetus problem can be identified by finding information about the fetus to avoid stillbirths. The gold standard used to monitor the health status of the fetus is by Cardiotachography(CTG), cannot be used for long durations and continuous monitoring. There is a need for continuous and long duration monitoring of fetal ECG signals to study the progressive health status of the fetus using portable devices. The non-invasive method of electrocardiogram recording is one of the best method used to diagnose fetal cardiac problem rather than the invasive methods.The monitoring of the fECG requires development of a miniaturized hardware and a efficient signal processing algorithms to extract the fECG embedded in the mother ECG. The paper discusses a prototype hardware developed to monitor and record the raw mother ECG signal containing the fECG and a signal processing algorithm to extract the fetal Electro Cardiogram signal. We have proposed two methods of signal processing, first is based on the Least Mean Square (LMS) Adaptive Noise Cancellation technique and the other method is based on the Wavelet Transformation technique. A prototype hardware was designed and developed to acquire the raw ECG signal containing the mother and fetal ECG and the signal processing techniques were used to eliminate the noises and extract the fetal ECG and the fetal Heart Rate Variability was studied. Both the methods were evaluated with the signal acquired from a fetal ECG simulator, from the Physionet database and that acquired from the subject. Both the methods are evaluated by finding heart rate and its variability, amplitude spectrum and mean value of extracted fetal ECG. Also the accuracy, sensitivity and positive predictive value are also determined for fetal QRS detection technique. In this paper adaptive filtering technique uses Sign-sign LMS algorithm and wavelet techniques with Daubechies wavelet, employed along with de noising techniques for the extraction of fetal Electrocardiogram.Both the methods are having good sensitivity and accuracy. In adaptive method the sensitivity is 96.83, accuracy 89.87, wavelet sensitivity is 95.97 and accuracy is 88.5. Additionally, time domain parameters from the plot of heart rate variability of mother and fetus are analyzed.  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