The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate str...The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.展开更多
目的探讨单核细胞单层实验(monocyte monolayer assay,MMA)是否能够用于IgG抗-M相关胎儿新生儿溶血病(hemolytic disease of fetus and newborn,HDFN)的预测。方法选取8例含有IgG抗-M的孕妇并采集血浆标本,其中有胎儿水肿等严重临床症...目的探讨单核细胞单层实验(monocyte monolayer assay,MMA)是否能够用于IgG抗-M相关胎儿新生儿溶血病(hemolytic disease of fetus and newborn,HDFN)的预测。方法选取8例含有IgG抗-M的孕妇并采集血浆标本,其中有胎儿水肿等严重临床症状及无明显临床症状的各4例;8份血浆用二硫苏糖醇(dithiothreitol,DTT)灭活,与M抗原阳性红细胞孵育致敏后,将致敏红细胞与单核细胞混合进行吞噬试验,同时设立阳性及阴性对照,并计算吞噬率;采用t检验对2组吞噬率进行比较。结果4例发生严重抗-M相关HDFN的孕妇的MMA吞噬率分别为15.37%、13.05%、9.17%和24.50%,均值为15.52%;检出IgG抗-M但未发生HDFN的孕妇,其MMA吞噬率分别为8.74%、11.07%、5.12%和6.23%,均值为7.79%,2组吞噬率无差异(P>0.05)。2组吞噬率分别与阴性对照比较均无差异(P>0.05),但均明显低于阳性对照(P<0.05)。结论IgG抗-M介导单核细胞吞噬的能力较低,提示抗-M导致胎儿水肿的机制可能并非红细胞被吞噬破坏而发生的溶血,因此体外单核细胞单层实验可能不适用于IgG抗-M相关HDFN的预测。对于检出IgG抗-M的孕妇,现仍需通过定期监测胎儿大脑中动脉血流,来判断胎儿宫内贫血情况。展开更多
Quantum anomalous Hall(QAH) insulators have highly potential applications in spintronic device. However,available candidates with tunable Chern numbers and high working temperature are quite rare. Here, we predict a 1...Quantum anomalous Hall(QAH) insulators have highly potential applications in spintronic device. However,available candidates with tunable Chern numbers and high working temperature are quite rare. Here, we predict a 1T-PrN_(2) monolayer as a stable QAH insulator with high magnetic transition temperature of above 600 K and tunable high Chern numbers of C = ±3 from first-principles calculations. Without spin-orbit coupling(SOC),the 1T-PrN_(2) monolayer is predicted to be a p-state Dirac half metal with high Fermi velocity. Rich topological phases depending on magnetization directions can be found when the SOC is considered. The QAH effect with periodical changes of Chern number(±1) can be produced when the magnetic moment breaks all twofold rotational symmetries in the xy plane. The critical state can be identified as Weyl half semimetals. When the magnetization direction is parallel to the z-axis, the system exhibits high Chern number QAH effect with C = ±3.Our work provides a new material for exploring novel QAH effect and developing high-performance topological devices.展开更多
Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical pr...Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).展开更多
基金Project supported by the National Natural Science Foundation of China (Grants No. 12075201)the Science and Technology Planning Project of Jiangsu Province, China (Grant No. BK20201428)+1 种基金the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China (Grant No. KYCX21 3193)the Special Program for Applied Research on Supercomputation of the NSFC–Guangdong Joint Fund (the second phase)。
文摘The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.
文摘目的探讨单核细胞单层实验(monocyte monolayer assay,MMA)是否能够用于IgG抗-M相关胎儿新生儿溶血病(hemolytic disease of fetus and newborn,HDFN)的预测。方法选取8例含有IgG抗-M的孕妇并采集血浆标本,其中有胎儿水肿等严重临床症状及无明显临床症状的各4例;8份血浆用二硫苏糖醇(dithiothreitol,DTT)灭活,与M抗原阳性红细胞孵育致敏后,将致敏红细胞与单核细胞混合进行吞噬试验,同时设立阳性及阴性对照,并计算吞噬率;采用t检验对2组吞噬率进行比较。结果4例发生严重抗-M相关HDFN的孕妇的MMA吞噬率分别为15.37%、13.05%、9.17%和24.50%,均值为15.52%;检出IgG抗-M但未发生HDFN的孕妇,其MMA吞噬率分别为8.74%、11.07%、5.12%和6.23%,均值为7.79%,2组吞噬率无差异(P>0.05)。2组吞噬率分别与阴性对照比较均无差异(P>0.05),但均明显低于阳性对照(P<0.05)。结论IgG抗-M介导单核细胞吞噬的能力较低,提示抗-M导致胎儿水肿的机制可能并非红细胞被吞噬破坏而发生的溶血,因此体外单核细胞单层实验可能不适用于IgG抗-M相关HDFN的预测。对于检出IgG抗-M的孕妇,现仍需通过定期监测胎儿大脑中动脉血流,来判断胎儿宫内贫血情况。
基金supported by National Natural Science Foundation of China (Grant No. 11874092)the Fok Ying Tong Education Foundation, China (Grant No. 161005)the Science Fund for Distinguished Young Scholars of Hunan Province (Grant No. 2021JJ10039)。
文摘Quantum anomalous Hall(QAH) insulators have highly potential applications in spintronic device. However,available candidates with tunable Chern numbers and high working temperature are quite rare. Here, we predict a 1T-PrN_(2) monolayer as a stable QAH insulator with high magnetic transition temperature of above 600 K and tunable high Chern numbers of C = ±3 from first-principles calculations. Without spin-orbit coupling(SOC),the 1T-PrN_(2) monolayer is predicted to be a p-state Dirac half metal with high Fermi velocity. Rich topological phases depending on magnetization directions can be found when the SOC is considered. The QAH effect with periodical changes of Chern number(±1) can be produced when the magnetic moment breaks all twofold rotational symmetries in the xy plane. The critical state can be identified as Weyl half semimetals. When the magnetization direction is parallel to the z-axis, the system exhibits high Chern number QAH effect with C = ±3.Our work provides a new material for exploring novel QAH effect and developing high-performance topological devices.
基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFE0202700 and 2023YFA1406500)the National Natural Science Foundation of China(Grant Nos.11974422 and 12104504)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)Fundamental Research Funds for the Central Universities,and Research Funds of Renmin University,China(Grant No.22XNKJ30)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2023 of Renmin University,China。
文摘Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).
