The covalently closed circular DNA(cccDNA)of HBV plays a crucial role in viral persistence and is also a risk factor for developing HBV-induced diseases,including liver fibrosis.Stimulator of interferon genes(STING),a...The covalently closed circular DNA(cccDNA)of HBV plays a crucial role in viral persistence and is also a risk factor for developing HBV-induced diseases,including liver fibrosis.Stimulator of interferon genes(STING),a master regulator of DNA-mediated innate immune activation,is a potential therapeutic target for viral infection and virus-related diseases.In this study,agonist-induced STING signaling activation in macrophages was revealed to inhibit cccDNA-mediated transcription and HBV replication via epigenetic modification in hepatocytes.Notably,STING activation could efficiently attenuate the severity of liver injury and fibrosis in a chronic recombinant cccDNA(rcccDNA)mouse model,which is a proven suitable research platform for HBV-induced fibrosis.Mechanistically,STING-activated autophagic flux could suppress macrophage inflammasome activation,leading to the amelioration of liver injury and HBV-induced fibrosis.Overall,the activation of STING signaling could inhibit HBV replication through epigenetic suppression of cccDNA and alleviate HBV-induced liver fibrosis through the suppression of macrophage inflammasome activation by activating autophagic flux in a chronic HBV mouse model.This study suggests that targeting the STING signaling pathway may be an important therapeutic strategy to protect against persistent HBV replication and HBV-induced fibrosis.展开更多
This manuscript presents an application of calculation methods in neutron activation analysis (NAA) of a large crude oil sample. Monte-Carlo computer code was developed. The computer code calculates neutron cross sect...This manuscript presents an application of calculation methods in neutron activation analysis (NAA) of a large crude oil sample. Monte-Carlo computer code was developed. The computer code calculates neutron cross sections and neutron flux density distribution in the interior large sample. ENDF/B-VII.0 data files and ENSDF BNL-NCS-51655-01/02-Rev data files were used as nuclear databases in our computer code. HPGe planar detector efficiency registration technique and the software were developed for the absolute NAA technique of the large sample. The concentrations of Na, K, Ca, Sc, Cr, Fe, Co, Ni, Cu, Zn, Ga, As, Br, Sr, Zr, Mo, Ag, Sb, Cs, Ba, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, Hf, Ta, W, Pt, Au, Hg, Th and U in the crude oil samples of Eastern Siberia oilfield were determined using calculation and relative techniques in the concentration range from 10-9 to 0.5%.展开更多
Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was...Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was added to its shim to compensate for excess reactivity loss. The thermal, epithermal and fast neutron fluxes were determined by the method of foil activation. The experimental samples with and without a cadmium cover of 1-mm thickness were irradiated in the isotropic neutron field of the irradiation sites of Ghana Research Reactor-1 facility. The induced activities in the sample were measured by gamma ray spectrometry with a high purity germanium detector. The necessary correction for gamma attenuation, thermal neutrons and resonance neutron self-shielding effects were taken into account during the experimental analysis. By defining cadmium cutoff energy of 0.55eV, Al-0.1% Au wires of negligible thickness were irradiated at 3kW to determine the neutron fluxes of two irradiation channels, outer channel 7 and inner channel 2 whose Neutron Shaping Factor (α) were found to be (0.037 ± 0.001) and (–0.961 ± 0.034). The neutron flux ratios at the inner irradiation site 2 were found to be, (25.308 ± 3.201) for thermal to epithermal neutrons flux, (0.179 ± 0.021) for epithermal to fast neutrons flux and (4.528 ± 0.524) for thermal to fast neutrons flux, in the outer irradiation site 7, the neutron flux ratios were found to be, (40.865 ± 3.622) for thermal to epithermal neutrons flux, (0.286 ± 0.025) for epithermal to fast neutrons flux and (11.680 ± 1.030) for thermal to fast neutrons flux.展开更多
In this investigation we analyze the rotating three-dimensional magnetohydrodynamic flow of Maxwell fluid in attendance of binary chemical reaction with activation energy. Furthermore, effects of non-Fourier heat flux...In this investigation we analyze the rotating three-dimensional magnetohydrodynamic flow of Maxwell fluid in attendance of binary chemical reaction with activation energy. Furthermore, effects of non-Fourier heat flux are taken into account. Formulation is done in the presence of heat and mass convective boundary conditions. Self-similar forms from boundary layer equations are obtained using apposite transformations. Numerical solution is obtained via built-in bvp-4c function in MATLAB for the system of differential equations. Effects of ensuing parameters on flow distributions are portrayed graphically. It is witnessed that increasing values of rotational parameter lowers the velocity profile and both Biot numbers have escalating effect on temperature and concentration distributions. A comparative study to a previously done investigation is also included to corroborate our results.展开更多
One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their r...One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their respective receptors on the cell membrane [1]. To demonstrate the mitogenio action of transferrin, our results show that an addition of transferrin to 'serum-deprived' rat hepatoma cells produced a rapid but transient rise in inositol 1, 4, 5-trisphosphate (IP3) level, and at the same time, an increased intraoellular Oa2+ activity and a oytoplasmic alkalinization were observed. These signal transduo-tions further lend support to the mitogenic nature of transferrin. In addition, a possible link between the receptor-mediated endocytosis of transferrin with the generation of intraoellular signals is discussed herewith.展开更多
A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm...A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm thickness,a polyethylene moderator of 50-mm thickness,a source-to-sample distance of 70 mm,and cement samples of 1200 mm×600 mm×170 mm.To absorb thermal neutrons and suppress low-energy γ-rays,the optimum-sized sheets are 150 mm×7 mm Cd,and 150 mm×15 mm Pb.展开更多
通过对BPZ 220/5 W JA55型阳光球泡灯进行额定功率下40℃和60℃温度应力加速寿命实验,分析了该款LED球泡灯的失效机理.通过推导激活能计算公式,建立了计算光衰激活能的理论模型,给出了测试LED球泡灯光衰激活能方法.通过实验测定该款球...通过对BPZ 220/5 W JA55型阳光球泡灯进行额定功率下40℃和60℃温度应力加速寿命实验,分析了该款LED球泡灯的失效机理.通过推导激活能计算公式,建立了计算光衰激活能的理论模型,给出了测试LED球泡灯光衰激活能方法.通过实验测定该款球泡灯的光衰激活能数值为0.67 eV.展开更多
The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed ...The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed that the neutron relative flux proportion reduced with increasing cement thickness.When the cement thickness remains unchanged,the reduced proportion of thermal neutrons increases to a small extent,but the epithermal, intermediate,and fast neutrons will decrease according to the geometric progression.H element in the cement mainly affects the reduction of fast neutrons and other single-substance elements,e.g.,O,Ca,56Fe,Si,and Al.It also slows down the reduction of the fast neutrons via inelastic scattering.O contributes more than other elements in the reduction of fast neutrons.Changing the H content affects the thermal,epithermal,intermediate,and fast neutrons, while changing the Ca,Fe,and Si contents only influences the thermal,epithermal,and intermediate neutrons;hence, there is little effect on the reduction of fast neutrons.展开更多
Neutron activation analysis technique of the Gd2O2S:М scintillation ceramics was developed. The concentrations of 15 trace, minor and major elements (As, Ce, Co, Cr, Cs, Eu, Fe, La, Sc, Tb, Zn, Zr, Pr, Gd, Na) have b...Neutron activation analysis technique of the Gd2O2S:М scintillation ceramics was developed. The concentrations of 15 trace, minor and major elements (As, Ce, Co, Cr, Cs, Eu, Fe, La, Sc, Tb, Zn, Zr, Pr, Gd, Na) have been measured with the instrumental neutron activation analysis of the Gd2O2S:Pr sample. The concentrations range of the determined elements is from 3 × 10-8 to 2.0% in mass. The determination limit of the elements was calculated to be (0.6 - 1.3 × 10-8% in mass).展开更多
The fast and maximum thermal neutron fluxes from the DD-109 neutron generator at the University of Sharjah were experimentally measured by the activation technique using different neutron reactions. The thermal and fa...The fast and maximum thermal neutron fluxes from the DD-109 neutron generator at the University of Sharjah were experimentally measured by the activation technique using different neutron reactions. The thermal and fast neutron fluxes were found to be 2.960 × 10~6 and6.186 × 10~7 n/cm^2 s, respectively. This was done to verify the modeling results for the optimum moderator thickness needed to maximize the thermal neutron flux. The optimum moderator thickness was found to be between 3.5 and4 cm. The present data were compared with the detailed MCNP model-based calculation performed in earlier work to simulate the generator.展开更多
基金This work was supported by grants from the National Natural Science Foundation of China(C31872731,C32070910,C31470839)Zhengyi Scholar Foundation of School of Basic Medical Sciences,Fudan University(S25-01).
文摘The covalently closed circular DNA(cccDNA)of HBV plays a crucial role in viral persistence and is also a risk factor for developing HBV-induced diseases,including liver fibrosis.Stimulator of interferon genes(STING),a master regulator of DNA-mediated innate immune activation,is a potential therapeutic target for viral infection and virus-related diseases.In this study,agonist-induced STING signaling activation in macrophages was revealed to inhibit cccDNA-mediated transcription and HBV replication via epigenetic modification in hepatocytes.Notably,STING activation could efficiently attenuate the severity of liver injury and fibrosis in a chronic recombinant cccDNA(rcccDNA)mouse model,which is a proven suitable research platform for HBV-induced fibrosis.Mechanistically,STING-activated autophagic flux could suppress macrophage inflammasome activation,leading to the amelioration of liver injury and HBV-induced fibrosis.Overall,the activation of STING signaling could inhibit HBV replication through epigenetic suppression of cccDNA and alleviate HBV-induced liver fibrosis through the suppression of macrophage inflammasome activation by activating autophagic flux in a chronic HBV mouse model.This study suggests that targeting the STING signaling pathway may be an important therapeutic strategy to protect against persistent HBV replication and HBV-induced fibrosis.
文摘This manuscript presents an application of calculation methods in neutron activation analysis (NAA) of a large crude oil sample. Monte-Carlo computer code was developed. The computer code calculates neutron cross sections and neutron flux density distribution in the interior large sample. ENDF/B-VII.0 data files and ENSDF BNL-NCS-51655-01/02-Rev data files were used as nuclear databases in our computer code. HPGe planar detector efficiency registration technique and the software were developed for the absolute NAA technique of the large sample. The concentrations of Na, K, Ca, Sc, Cr, Fe, Co, Ni, Cu, Zn, Ga, As, Br, Sr, Zr, Mo, Ag, Sb, Cs, Ba, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, Hf, Ta, W, Pt, Au, Hg, Th and U in the crude oil samples of Eastern Siberia oilfield were determined using calculation and relative techniques in the concentration range from 10-9 to 0.5%.
文摘Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was added to its shim to compensate for excess reactivity loss. The thermal, epithermal and fast neutron fluxes were determined by the method of foil activation. The experimental samples with and without a cadmium cover of 1-mm thickness were irradiated in the isotropic neutron field of the irradiation sites of Ghana Research Reactor-1 facility. The induced activities in the sample were measured by gamma ray spectrometry with a high purity germanium detector. The necessary correction for gamma attenuation, thermal neutrons and resonance neutron self-shielding effects were taken into account during the experimental analysis. By defining cadmium cutoff energy of 0.55eV, Al-0.1% Au wires of negligible thickness were irradiated at 3kW to determine the neutron fluxes of two irradiation channels, outer channel 7 and inner channel 2 whose Neutron Shaping Factor (α) were found to be (0.037 ± 0.001) and (–0.961 ± 0.034). The neutron flux ratios at the inner irradiation site 2 were found to be, (25.308 ± 3.201) for thermal to epithermal neutrons flux, (0.179 ± 0.021) for epithermal to fast neutrons flux and (4.528 ± 0.524) for thermal to fast neutrons flux, in the outer irradiation site 7, the neutron flux ratios were found to be, (40.865 ± 3.622) for thermal to epithermal neutrons flux, (0.286 ± 0.025) for epithermal to fast neutrons flux and (11.680 ± 1.030) for thermal to fast neutrons flux.
基金Supported by the Korea Ministry of Trade,Industry and Energy,"Energy Technology Development Work in 2017",Project No.20172010105570
文摘In this investigation we analyze the rotating three-dimensional magnetohydrodynamic flow of Maxwell fluid in attendance of binary chemical reaction with activation energy. Furthermore, effects of non-Fourier heat flux are taken into account. Formulation is done in the presence of heat and mass convective boundary conditions. Self-similar forms from boundary layer equations are obtained using apposite transformations. Numerical solution is obtained via built-in bvp-4c function in MATLAB for the system of differential equations. Effects of ensuing parameters on flow distributions are portrayed graphically. It is witnessed that increasing values of rotational parameter lowers the velocity profile and both Biot numbers have escalating effect on temperature and concentration distributions. A comparative study to a previously done investigation is also included to corroborate our results.
文摘One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their respective receptors on the cell membrane [1]. To demonstrate the mitogenio action of transferrin, our results show that an addition of transferrin to 'serum-deprived' rat hepatoma cells produced a rapid but transient rise in inositol 1, 4, 5-trisphosphate (IP3) level, and at the same time, an increased intraoellular Oa2+ activity and a oytoplasmic alkalinization were observed. These signal transduo-tions further lend support to the mitogenic nature of transferrin. In addition, a possible link between the receptor-mediated endocytosis of transferrin with the generation of intraoellular signals is discussed herewith.
基金Supported by NSFC(40974065)National Innovation Method(2008IM021500)+1 种基金National Key Technology R & D Program(2008BAC44B04)Province Key Technology R & D Program(2008SZ0148,2008GZ0197,2008GZ0040)
文摘A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm thickness,a polyethylene moderator of 50-mm thickness,a source-to-sample distance of 70 mm,and cement samples of 1200 mm×600 mm×170 mm.To absorb thermal neutrons and suppress low-energy γ-rays,the optimum-sized sheets are 150 mm×7 mm Cd,and 150 mm×15 mm Pb.
基金Supported by National Natural Science Foundation for Distinguished Young Scholar(41025015)NSFC(40974065,11105132)+3 种基金Province Key Technology R&D Program(2011FZ0055)National High Technology Research and Development Program of China(2012AA063501)the Basic Research for Application of Sichuan Province(2012JY0109)China Postdoctoral Science Foundation(2012M520245)
文摘The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed that the neutron relative flux proportion reduced with increasing cement thickness.When the cement thickness remains unchanged,the reduced proportion of thermal neutrons increases to a small extent,but the epithermal, intermediate,and fast neutrons will decrease according to the geometric progression.H element in the cement mainly affects the reduction of fast neutrons and other single-substance elements,e.g.,O,Ca,56Fe,Si,and Al.It also slows down the reduction of the fast neutrons via inelastic scattering.O contributes more than other elements in the reduction of fast neutrons.Changing the H content affects the thermal,epithermal,intermediate,and fast neutrons, while changing the Ca,Fe,and Si contents only influences the thermal,epithermal,and intermediate neutrons;hence, there is little effect on the reduction of fast neutrons.
文摘Neutron activation analysis technique of the Gd2O2S:М scintillation ceramics was developed. The concentrations of 15 trace, minor and major elements (As, Ce, Co, Cr, Cs, Eu, Fe, La, Sc, Tb, Zn, Zr, Pr, Gd, Na) have been measured with the instrumental neutron activation analysis of the Gd2O2S:Pr sample. The concentrations range of the determined elements is from 3 × 10-8 to 2.0% in mass. The determination limit of the elements was calculated to be (0.6 - 1.3 × 10-8% in mass).
文摘The fast and maximum thermal neutron fluxes from the DD-109 neutron generator at the University of Sharjah were experimentally measured by the activation technique using different neutron reactions. The thermal and fast neutron fluxes were found to be 2.960 × 10~6 and6.186 × 10~7 n/cm^2 s, respectively. This was done to verify the modeling results for the optimum moderator thickness needed to maximize the thermal neutron flux. The optimum moderator thickness was found to be between 3.5 and4 cm. The present data were compared with the detailed MCNP model-based calculation performed in earlier work to simulate the generator.
