Three crucial hurdles hinder studies on human cytomegalovirus(HCMV): strict species specificity, differences between in vivo and in vitro infection, and the complexity of gene regulation. Ever since the sequencing of ...Three crucial hurdles hinder studies on human cytomegalovirus(HCMV): strict species specificity, differences between in vivo and in vitro infection, and the complexity of gene regulation. Ever since the sequencing of the whole genome was first accomplished, functional studies on individual genes have been the mainstream in the CMV field. Gene regulation has therefore been elucidated in a more detailed fashion. However, viral gene regulation is largely controlled by both cellular and viral components. In other words, viral gene expression is determined by the virus–host interaction. Generally, cells respond to viral infection in a defensive pattern; at the same time, viruses try to counteract the cellular defense or else hide in the host(latency). Viruses evolve effective strategies against cellular defense in order to achieve replicative success. Whether or not they are successful, cellular defenses remain in the whole viral replication cycle: entry, immediate–early(IE) gene expression, early gene expression, DNA replication, late gene expression, and viral egress. Many viral strategies against cellular defense, and which occur in the immediate–early time of viral infection, have been documented. In this review, we will summarize the documented biological functions of IE1 and pp71 proteins, especially with regard to how they counteract cellular intrinsic defenses.展开更多
Herpes simplex virus 1(HSV-1) is a ubiquitous human pathogen that establishes latent infection in ganglia neurons. Its unique life cycle requires a balanced "conquer and compromise" strategy to deal with the...Herpes simplex virus 1(HSV-1) is a ubiquitous human pathogen that establishes latent infection in ganglia neurons. Its unique life cycle requires a balanced "conquer and compromise" strategy to deal with the host anti-viral defenses. One of HSV-1 α(immediate early) gene products, infected cell protein 0(ICP0), is a multifunctional protein that interacts with and modulates a wide range of cellular defensive pathways. These pathways may locate in different cell compartments, which then migrate or exchange factors upon stimulation, for the purpose of a concerted and effective defense. ICP0 is able to simultaneously attack multiple host pathways by either degrading key restrictive factors or modifying repressive complexes. This is a viral protein that contains an E3 ubiquitin ligase, translocates among different cell compartments and interacts with major defensive complexes. The multiple functional domains of ICP0 can work independently and at the same time coordinate with each other. Dissecting the functional domains of ICP0 and delineating the coordination of these domains will help us understand HSV-1 pathogenicity as well as host defense mechanisms. This article focuses on describing individual ICP0 domains, their biochemical properties and their implication in HSV-1 infection. By putting individual domain functions back into the picture of host anti-viral defense network, this review seeks to elaborate the complex interactions between HSV-1 and its host.展开更多
The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.5...The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.展开更多
The non-isothermal decomposition reaction of Nd[(C_5H_ 10NS_2)_3(C_ 12H_8N_2)] were carried out by means of TG-DTG and the thermal decomposition mechanism, and the associated kinetics was investigated. The kinetic par...The non-isothermal decomposition reaction of Nd[(C_5H_ 10NS_2)_3(C_ 12H_8N_2)] were carried out by means of TG-DTG and the thermal decomposition mechanism, and the associated kinetics was investigated. The kinetic parameters are obtained from an analysis of the TG-DTG curves at different heating rate by integral and differential methods. The most probable kinetic model function of the decomposition reaction is Maple Power of n=3/2, f(α)=2/3α -1/2 and the apparent activation energy E is 116.67 kJ·mol -1 and the pre-exponential factor lg[A/s -1] is 7.6891.展开更多
We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O...We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O10shows a paramagnetic metallic behavior with a metal-to-metal phase transition(T^*)at about 162 K,as revealed by both magnetic susceptibility and resistivity.Further magnetoresistance and Hall coefficient results show a negative magnetoresistance at low temperatures and the carrier type of Nd4Ni3O10is dominated by hole-type charge carriers.The significant enhancement of Hall coefficient and resistivity below T*suggests that effective charge carrier density decreases when cooling through the transition temperature.In contrast,Nd4Ni3O8 shows an insulating behavior.In addition,this compound shows a paramagnetic behavior with the similar magnetic moment as that of Nd4Ni3O10derived from the Curie-Weiss fitting.This may suggest that the magnetic moments in both systems are contributed by Nd^3+ ions.By applying pressures up to about 49 GPa,the insulating behavior is still present and becomes even stronger under a high pressure.Our results suggest that the different Ni configurations(Ni^1+/2+ or Ni^2+/3+)and the changes of coordination environment of Ni sites may account for the contrasting behaviors in trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.展开更多
基金supported by a pilot grant from the Research Center for Minority Institutes (RCMI) program (2G12RR003050-24/8G12MD007579-27) (Q.T.)an American Cancer Society grant (RSG-090289-01MPC) (Q.T)+1 种基金NIH/NIAID SC1AI112785 (Q.T.)the Ponce Health Sciences University/RCMI Publications Office (G12 RR003050/8G12MD007579-27)
文摘Three crucial hurdles hinder studies on human cytomegalovirus(HCMV): strict species specificity, differences between in vivo and in vitro infection, and the complexity of gene regulation. Ever since the sequencing of the whole genome was first accomplished, functional studies on individual genes have been the mainstream in the CMV field. Gene regulation has therefore been elucidated in a more detailed fashion. However, viral gene regulation is largely controlled by both cellular and viral components. In other words, viral gene expression is determined by the virus–host interaction. Generally, cells respond to viral infection in a defensive pattern; at the same time, viruses try to counteract the cellular defense or else hide in the host(latency). Viruses evolve effective strategies against cellular defense in order to achieve replicative success. Whether or not they are successful, cellular defenses remain in the whole viral replication cycle: entry, immediate–early(IE) gene expression, early gene expression, DNA replication, late gene expression, and viral egress. Many viral strategies against cellular defense, and which occur in the immediate–early time of viral infection, have been documented. In this review, we will summarize the documented biological functions of IE1 and pp71 proteins, especially with regard to how they counteract cellular intrinsic defenses.
基金Supported by National Institute of Allergy and Infectious Diseases,No.1R01AI118992
文摘Herpes simplex virus 1(HSV-1) is a ubiquitous human pathogen that establishes latent infection in ganglia neurons. Its unique life cycle requires a balanced "conquer and compromise" strategy to deal with the host anti-viral defenses. One of HSV-1 α(immediate early) gene products, infected cell protein 0(ICP0), is a multifunctional protein that interacts with and modulates a wide range of cellular defensive pathways. These pathways may locate in different cell compartments, which then migrate or exchange factors upon stimulation, for the purpose of a concerted and effective defense. ICP0 is able to simultaneously attack multiple host pathways by either degrading key restrictive factors or modifying repressive complexes. This is a viral protein that contains an E3 ubiquitin ligase, translocates among different cell compartments and interacts with major defensive complexes. The multiple functional domains of ICP0 can work independently and at the same time coordinate with each other. Dissecting the functional domains of ICP0 and delineating the coordination of these domains will help us understand HSV-1 pathogenicity as well as host defense mechanisms. This article focuses on describing individual ICP0 domains, their biochemical properties and their implication in HSV-1 infection. By putting individual domain functions back into the picture of host anti-viral defense network, this review seeks to elaborate the complex interactions between HSV-1 and its host.
基金This work was supported by the National Natural Science Foundation of China (50272066) and Key Project of Science and Technology of Fujian Province (2001H107)
文摘The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.
文摘The non-isothermal decomposition reaction of Nd[(C_5H_ 10NS_2)_3(C_ 12H_8N_2)] were carried out by means of TG-DTG and the thermal decomposition mechanism, and the associated kinetics was investigated. The kinetic parameters are obtained from an analysis of the TG-DTG curves at different heating rate by integral and differential methods. The most probable kinetic model function of the decomposition reaction is Maple Power of n=3/2, f(α)=2/3α -1/2 and the apparent activation energy E is 116.67 kJ·mol -1 and the pre-exponential factor lg[A/s -1] is 7.6891.
基金supported by the National Key R&D Program of China(Grant Nos.2016YFA0300401,and 2016YFA0401704)the National Natural Science Foundation of China(Grant Nos.A0402/11534005,and A0402/11674164)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000)。
文摘We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O10shows a paramagnetic metallic behavior with a metal-to-metal phase transition(T^*)at about 162 K,as revealed by both magnetic susceptibility and resistivity.Further magnetoresistance and Hall coefficient results show a negative magnetoresistance at low temperatures and the carrier type of Nd4Ni3O10is dominated by hole-type charge carriers.The significant enhancement of Hall coefficient and resistivity below T*suggests that effective charge carrier density decreases when cooling through the transition temperature.In contrast,Nd4Ni3O8 shows an insulating behavior.In addition,this compound shows a paramagnetic behavior with the similar magnetic moment as that of Nd4Ni3O10derived from the Curie-Weiss fitting.This may suggest that the magnetic moments in both systems are contributed by Nd^3+ ions.By applying pressures up to about 49 GPa,the insulating behavior is still present and becomes even stronger under a high pressure.Our results suggest that the different Ni configurations(Ni^1+/2+ or Ni^2+/3+)and the changes of coordination environment of Ni sites may account for the contrasting behaviors in trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.
