BACKGROUND: With the development of biotechnology, the electrophysiology of repairing heart tissues of myocardial infarction or myocardial hypertrophy by using bone marrow mesenchymal stem cell has become a hot spot. OBJECTIVE: To overview the research progress of cardiac electrophysiological characteristics after transplantation of induced differentiation of bone marrow mesenchymal stem cells into cardiomyocytes. METHODS: The databases of PubMed, Springer Link, Science Direct and CNKI were retrieved for papers published from January 2000 to October 2010 with the key words of bone marrow mesenchymal stem cells, cardiac/heart, electrophysiology/electrophysiological characteristics. The relevant articles concerning cardiac electrophysiological characteristics of induce differentiation and transplantation of bone marrow stem cells were collected. RESULTS AND CONCLUSION: Totally 208 papers have been searched. Preliminary screening by reading abstracts to exclude 162 papers that study purpose do not coincident with this review either contents duplicated, and internalized 46 papers at last. Bone marrow mesenchymal stem cells after induced differentiation and transplantation could improve heart function of animal experimental model and myocardial infarction or myocardial hypertrophy patients. Although the cardiomyocyte-like cells from bone marrow mesenchymal stem cells could help to improve heart function, the cardiac electrophysiological characteristics may be influenced by them.

ObjectiveTo investigate the noise level and influencing factors in metro platforms and station halls， thereby providing the scientific basis for the establishment of hygienic standards. MethodsDuring the morning peak（7：00‒9：30）and off-peak （9：30‒17：00） on weekdays， the noise levels were measured with noise meters at 39 monitoring points of 13 station platforms and 31 monitoring points of 6 station halls. The monitoring points arrangement and detection methods referred to the Examination methods for public places—Part 1： physical parameters（GB/T 18204.1‒2013）. ResultsThe measured noise level in the station ranged from 69.25 to 86.17 dB（A）， accounting for 44.74% below 75 dB（A）， 89.47% below 80 dB（A） and 97.37% below 85 dB（A）.The noise level of the platform ［（76.38±4.19） dB（A）］ was higher than that of the station hall ［（74.24±4.50） dB（A）］（P<0.01）. The noise level of the elevated platforms ［（80.01±2.25） dB（A）］ was higher than that of the underground platforms ［（75.73±4.13） dB（A）］（P<0.01）， and the noise level of the platforms without platform screen doors（PSD） ［（80.21±5.08） dB（A）］ was higher than that of platforms with PSD［（74.73±3.16） dB（A）］ （P<0.01）. No statistical significant differences were observed among the different areas of the platforms， monitoring periods， platform depth， exit mode and operation years （P>0.05）. ConclusionThe noise level in metro stations in the city does not fully meet the requirements of current relevant standards. It is suggested to take noise reduction measures to reduce the noise of metro stations.