In this paper, we use a molecular theory to study the anomalous switching of ssDNA monolayers. Here, both ssDNA- water and water-water hydrogen bonds and their explicit coupling to the ssDNA conformations are consider...In this paper, we use a molecular theory to study the anomalous switching of ssDNA monolayers. Here, both ssDNA- water and water-water hydrogen bonds and their explicit coupling to the ssDNA conformations are considered. We find that hydrogen bonding becomes a key element in inducing the anomalous switching of ssDNA monolayers. This finding accords well with the experimental observations. Based on our theoretical model, we predict that the anomalous switching induced by water vapor will be applicable to a wide range of hydrogen bonds polymers, and ssDNA-water hydrogen bonds and water-water hydrogen bonds hybridization will lead to the hydrogen-bond network formation of 3D ssDNA monolayers.展开更多
The interaction between two single-stranded DNA （ssDNA） molecules as pairing to a double-stranded DNA （dsDNA） molecule is studied by the reflectometric interference spectroscopy （RIFS） technology. A nano-porous ...The interaction between two single-stranded DNA （ssDNA） molecules as pairing to a double-stranded DNA （dsDNA） molecule is studied by the reflectometric interference spectroscopy （RIFS） technology. A nano-porous anode alumina membrane coated an Au layer is employed as the sensor substrate. The results indicate that when there are mismatched nucleotide bases, the effective optical thicknesses （OTeft） have obvious difference, and the changes of OTeff are connected with the sensor layer thickness and the effective refractive index. It is also demonstrated that the RIFS technique can be used to precisely detect the ssDNA molecules with individual base mismatched as pairing to dsDNA.展开更多
AIM. To evaluate bhe activity of apoptosis in liver tissue and explore its possible association with hepatic necroinflammarion and fibrosis as well as serum hepatitis C virus （HCV） load. METHODS： The studied popula...AIM. To evaluate bhe activity of apoptosis in liver tissue and explore its possible association with hepatic necroinflammarion and fibrosis as well as serum hepatitis C virus （HCV） load. METHODS： The studied population included 50 chronic hepatitis C patients （20 women and 30 men, aged 18-66 years）. HCV-RNA quantification was performed by two-step real-time quantitative RT-PCR mebhod using the TaqMan technology （reagents of Applera Corporation firm, USA）. The morphology of liver tissue was assessed descriptively and scored （necroinflammatory activity and fibrosis）. The early apoptosis activity in liver tissue was examined by ssDNA apoptosis ELISA kit, （Chemicon, Germany）. RESULTS： The correlation between apoptosis and fibrosis in liver tissue was observed. High intensification of apoptosis was proportional to the increase of fibrosis （ssDNA： 16.65×10^-5μg/g; 12.71×10^-5μg/g）, however, bhis difference was not statistically significant （P〉0.05）. Activity of apoptosis in the liver tissue, expressed by ssDNA concentration did not depend on hepatic necroinflammatory changes, HCVRNA viral load, ALT, and AST activity as well as prothrombin time and INR index. CONCLUSION： Fibrosis in the tissue is closely associated with early apoptosis in HCV-infected patients.展开更多
The hunt for agents that are suitable for actinide decorporation to reduce the whole-body load of actinide in accidental internal exposure is the ever-lasting goal in radiation protection and medical treatment in nucl...The hunt for agents that are suitable for actinide decorporation to reduce the whole-body load of actinide in accidental internal exposure is the ever-lasting goal in radiation protection and medical treatment in nuclear emergency.All current decorporation agents can be categorized as two groups,one is the molecular ligands,and the other is the nanoparticles decorated with molecular ligands.Here in this work,functional nanodiamonds(fN Ds)with ss DNA(the endogenous biomacromolecule rich in phosphate groups)loaded on the NDs is reported,which poses good uranyl adsorption selectivity,high cellular uptake,fast excretion,and effective decorporation of uranyl from rat renal proximal tubular epithelial cells(NRK-52E).All those results corroborate that f NDs can potentially serve as a brand new family of chelators for actinide decorporation.展开更多
单链DNA(single-stranded DNA,ssDNA)适配体是通过体外配体指数富集系统进化筛选获得的较短的单链脱氧核糖核苷酸序列。它们能够通过构象变化实现与靶标高亲和力和特异性结合,具有制备简单、成本低、稳定性高、易于修饰和免疫原性低等优...单链DNA(single-stranded DNA,ssDNA)适配体是通过体外配体指数富集系统进化筛选获得的较短的单链脱氧核糖核苷酸序列。它们能够通过构象变化实现与靶标高亲和力和特异性结合,具有制备简单、成本低、稳定性高、易于修饰和免疫原性低等优点,因此被称为“化学抗体”。ssDNA适配体已在食品安全检测领域显示出巨大潜力。作者综述了基于细胞指数富集配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术发展的ssDNA适配体筛选技术,以及ssDNA适配体在食源性致病菌检测领域中的应用,总结了目前研究的不足以及未来发展方向,旨在为提高食品安全监管与食源性疾病预防和控制效果提供理论依据。展开更多
DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surf...DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surface affects the adsorption process of single-strand DNA(ssDNA).In this paper,based on the molecular dynamics simulations,we find that ssDNA molecule is absorbed on the GO surface in the most stable state with the oxidation degree around 15%.The microscopic mechanism is attributed to the van Der Walls and the electrostatic interactions between the ssDNA molecule and the graphene-based surface,which is accompanied with theπ-πstacking and hydrogen bond formation.The number ofπ-πstacking between ssDNA and GO reaches the maximum value when the oxidation degree is around 15%among all the GO surfaces.Our simulation results also reveal the coexistence of stretched and curved configurations as well as the adsorption orientation of ssDNA on the GO surface.Furthermore,it is found that the absorbed ssDNA molecules are more likely to move on the graphene-based surface of low oxidation degree,especially on pristine graphene.Our work provides the physics picture of ssDNA’s physisorption dynamics onto graphene-based surface and it is helpful in designing DNA/GO nanomaterials.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21264016,11464047,and 21364016)the National Basic Research Program of China(Grant No.2012CB821500)the Natural Science Foundation of Xinjiang Uygur Autonomous Region,China(Grant No.2013211A053)
文摘In this paper, we use a molecular theory to study the anomalous switching of ssDNA monolayers. Here, both ssDNA- water and water-water hydrogen bonds and their explicit coupling to the ssDNA conformations are considered. We find that hydrogen bonding becomes a key element in inducing the anomalous switching of ssDNA monolayers. This finding accords well with the experimental observations. Based on our theoretical model, we predict that the anomalous switching induced by water vapor will be applicable to a wide range of hydrogen bonds polymers, and ssDNA-water hydrogen bonds and water-water hydrogen bonds hybridization will lead to the hydrogen-bond network formation of 3D ssDNA monolayers.
基金Supported by the National Natural Science Foundation of China under Grant No 61378083the International Cooperation Foundation of the Ministry of Science and Technology of China under Grant No 2011DFA12220+2 种基金the Major Research Plan of National Natural Science Foundation of China under Grant No 91123030the Natural Science Foundation of Shaanxi Province under Grant Nos 2010JS110 and 2013SZS03-Z01the Major Basic Research Project of the Natural Science Basic Research Program of Shaanxi Province under Grant No 2016ZDJC-15
文摘The interaction between two single-stranded DNA （ssDNA） molecules as pairing to a double-stranded DNA （dsDNA） molecule is studied by the reflectometric interference spectroscopy （RIFS） technology. A nano-porous anode alumina membrane coated an Au layer is employed as the sensor substrate. The results indicate that when there are mismatched nucleotide bases, the effective optical thicknesses （OTeft） have obvious difference, and the changes of OTeff are connected with the sensor layer thickness and the effective refractive index. It is also demonstrated that the RIFS technique can be used to precisely detect the ssDNA molecules with individual base mismatched as pairing to dsDNA.
文摘AIM. To evaluate bhe activity of apoptosis in liver tissue and explore its possible association with hepatic necroinflammarion and fibrosis as well as serum hepatitis C virus （HCV） load. METHODS： The studied population included 50 chronic hepatitis C patients （20 women and 30 men, aged 18-66 years）. HCV-RNA quantification was performed by two-step real-time quantitative RT-PCR mebhod using the TaqMan technology （reagents of Applera Corporation firm, USA）. The morphology of liver tissue was assessed descriptively and scored （necroinflammatory activity and fibrosis）. The early apoptosis activity in liver tissue was examined by ssDNA apoptosis ELISA kit, （Chemicon, Germany）. RESULTS： The correlation between apoptosis and fibrosis in liver tissue was observed. High intensification of apoptosis was proportional to the increase of fibrosis （ssDNA： 16.65×10^-5μg/g; 12.71×10^-5μg/g）, however, bhis difference was not statistically significant （P〉0.05）. Activity of apoptosis in the liver tissue, expressed by ssDNA concentration did not depend on hepatic necroinflammatory changes, HCVRNA viral load, ALT, and AST activity as well as prothrombin time and INR index. CONCLUSION： Fibrosis in the tissue is closely associated with early apoptosis in HCV-infected patients.
基金supported by grants from the National Natural Science Foundation of China(Nos.82050005,21976127,22022410)the Youth Innovation Promotion Association of CAS(No.2016236)+2 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20190044,BK20210736)funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the China Postdoctoral Science Foundation(No.2020M681431)。
文摘The hunt for agents that are suitable for actinide decorporation to reduce the whole-body load of actinide in accidental internal exposure is the ever-lasting goal in radiation protection and medical treatment in nuclear emergency.All current decorporation agents can be categorized as two groups,one is the molecular ligands,and the other is the nanoparticles decorated with molecular ligands.Here in this work,functional nanodiamonds(fN Ds)with ss DNA(the endogenous biomacromolecule rich in phosphate groups)loaded on the NDs is reported,which poses good uranyl adsorption selectivity,high cellular uptake,fast excretion,and effective decorporation of uranyl from rat renal proximal tubular epithelial cells(NRK-52E).All those results corroborate that f NDs can potentially serve as a brand new family of chelators for actinide decorporation.
文摘单链DNA(single-stranded DNA,ssDNA)适配体是通过体外配体指数富集系统进化筛选获得的较短的单链脱氧核糖核苷酸序列。它们能够通过构象变化实现与靶标高亲和力和特异性结合,具有制备简单、成本低、稳定性高、易于修饰和免疫原性低等优点,因此被称为“化学抗体”。ssDNA适配体已在食品安全检测领域显示出巨大潜力。作者综述了基于细胞指数富集配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术发展的ssDNA适配体筛选技术,以及ssDNA适配体在食源性致病菌检测领域中的应用,总结了目前研究的不足以及未来发展方向,旨在为提高食品安全监管与食源性疾病预防和控制效果提供理论依据。
基金supported by the National Natural Science Foundation of China(Grant Nos.11305237 and 11974366)the Fundamental Research Funds for the Central Universities,China,the Natural Science Foundation of Shanghai,China(Grant No.19ZR1463200)the Key Research Program of Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SLH053).
文摘DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surface affects the adsorption process of single-strand DNA(ssDNA).In this paper,based on the molecular dynamics simulations,we find that ssDNA molecule is absorbed on the GO surface in the most stable state with the oxidation degree around 15%.The microscopic mechanism is attributed to the van Der Walls and the electrostatic interactions between the ssDNA molecule and the graphene-based surface,which is accompanied with theπ-πstacking and hydrogen bond formation.The number ofπ-πstacking between ssDNA and GO reaches the maximum value when the oxidation degree is around 15%among all the GO surfaces.Our simulation results also reveal the coexistence of stretched and curved configurations as well as the adsorption orientation of ssDNA on the GO surface.Furthermore,it is found that the absorbed ssDNA molecules are more likely to move on the graphene-based surface of low oxidation degree,especially on pristine graphene.Our work provides the physics picture of ssDNA’s physisorption dynamics onto graphene-based surface and it is helpful in designing DNA/GO nanomaterials.
