Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populat...Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populations,particularly for pneumonia.Methods We developed a method to evaluate risks from airborne microorganisms,guided by the principle that closer evolutionary relationships reflect similar biological characteristics,and thus used16 S rDNA sequences of 10 common pneumonia-related bacterial pathogens.We calculated a risk of breath-related(Rbr)index of airborne bacterial communities and verified effectiveness with artificial flora and a clinical project.Results We suggested applying Rbr80 to evaluate the health risks of airborne bacterial communities that comprise 80% of dominant operational taxonomic units(OTUs).The feasibility of Rbr80 was confirmed by artificial flora and by pneumonia data from a hospital.A high Rbr80 value indicated a high risk of pneumonia from airborne bacterial communities.Conclusion Rbr80 is an effective index to evaluate the pneumonia-associated risk from airborne bacteria.Values of Rbr80 greater than 15.40 are considered high risk.展开更多
Intrinsic carrier concentration(ni) is one of the most important physical parameters for understanding the physics of strained Si and Si1-xGex materials as well as for evaluating the electrical properties of Si-based ...Intrinsic carrier concentration(ni) is one of the most important physical parameters for understanding the physics of strained Si and Si1-xGex materials as well as for evaluating the electrical properties of Si-based strained devices. Up to now, the report on quantitative results of intrinsic carrier concentration in strained Si and Si1-xGex materials has been still lacking. In this paper, by analyzing the band structure of strained Si and Si1-xGex materials, both the effective densities of the state near the top of valence band and the bottom of conduction band( Nc and Nv) at 218, 330 and 393 K and the intrinsic carrier concentration related to Ge fraction(x) at 300 K were systematically studied within the framework of KP theory and semiconductor physics. It is found that the intrinsic carrier concentration in strained Si(001) and Si1-xGex(001) and(101) materials at 300 K increases significantly with increasing Ge fraction(x), which provides valuable references to understand the Sibased strained device physics and design.展开更多
基金supported by the CAMS Innovation Fund for Medical Science[CIFMS,2018-I2M-1-001]the National Key R&D Program of China[2017YFC0702800]+1 种基金the National Natural Science Foundation of China[82070103]the Central Public-interest Scientific Institution Basal Research Fund[2016ZX310037]。
文摘Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populations,particularly for pneumonia.Methods We developed a method to evaluate risks from airborne microorganisms,guided by the principle that closer evolutionary relationships reflect similar biological characteristics,and thus used16 S rDNA sequences of 10 common pneumonia-related bacterial pathogens.We calculated a risk of breath-related(Rbr)index of airborne bacterial communities and verified effectiveness with artificial flora and a clinical project.Results We suggested applying Rbr80 to evaluate the health risks of airborne bacterial communities that comprise 80% of dominant operational taxonomic units(OTUs).The feasibility of Rbr80 was confirmed by artificial flora and by pneumonia data from a hospital.A high Rbr80 value indicated a high risk of pneumonia from airborne bacterial communities.Conclusion Rbr80 is an effective index to evaluate the pneumonia-associated risk from airborne bacteria.Values of Rbr80 greater than 15.40 are considered high risk.
基金Funded by the National Natural Science Foundation of China(Nos.51278058,41404095,51277012,61201233)the Fundamental Research Funds for the Central Universities(Nos.2013G1241120,2013G1241107,2013G1241114,CHD2011ZD004)+1 种基金Research Fund of Shaanxi Provincial Research Center for Telecommunication ASIC Design(No.SXASIC2014-1)the Shaanxi Science and Technology Research and Development Program(No.2013KJXX-93)
文摘Intrinsic carrier concentration(ni) is one of the most important physical parameters for understanding the physics of strained Si and Si1-xGex materials as well as for evaluating the electrical properties of Si-based strained devices. Up to now, the report on quantitative results of intrinsic carrier concentration in strained Si and Si1-xGex materials has been still lacking. In this paper, by analyzing the band structure of strained Si and Si1-xGex materials, both the effective densities of the state near the top of valence band and the bottom of conduction band( Nc and Nv) at 218, 330 and 393 K and the intrinsic carrier concentration related to Ge fraction(x) at 300 K were systematically studied within the framework of KP theory and semiconductor physics. It is found that the intrinsic carrier concentration in strained Si(001) and Si1-xGex(001) and(101) materials at 300 K increases significantly with increasing Ge fraction(x), which provides valuable references to understand the Sibased strained device physics and design.
