The prominent role Ca^2＋ ion plays as a major small biological messenger is fascinating. There are many physiologically important ions, such as Na^＋, K^＋, H^＋, Cl^-, Ca^2＋, Mg2＋, Fe^3＋, and PO4^3- that particip...The prominent role Ca^2＋ ion plays as a major small biological messenger is fascinating. There are many physiologically important ions, such as Na^＋, K^＋, H^＋, Cl^-, Ca^2＋, Mg2＋, Fe^3＋, and PO4^3- that participate in cell signaling. Among them, monovalent ions primarily contribute to rapid electrical signaling, while multivalent ions generally act as a co-factor for chemical reactions by associating with the host molecule through electrostatic or covalent interactions. Ca^2＋ plays both roles. Its transmembrane influx supports the plateau phase of cardiac action potential and helps set the speed of pacemaker potential.展开更多
Langevin dynamics simulations were conducted to study the collapse of grafted partially charged 4-arm star chains onto the oppositely charged grafting electrode in the presence of trivalent salt coions.Simulation resu...Langevin dynamics simulations were conducted to study the collapse of grafted partially charged 4-arm star chains onto the oppositely charged grafting electrode in the presence of trivalent salt coions.Simulation results reveal that the average charge fraction of the grafted star chains and the salt concentration play critical roles in the competitive adsorption of charged monomers and trivalent salt coions onto the oppositely charged electrode.For grafted star chains with relatively high charge fraction,charged monomers are the dominant species collapsing on the oppositely charged electrode with the emergence of charge reversal on the grafting electrode.At a low charge fraction such that the total amount of charges on a grafted star molecule is comparable to that of a trivalent salt coion,trivalent salt coions absorb more strongly onto the electrode than grafted stars even at very low salt concentration.It is found that at relatively low charge fraction of star chains,the addition of trivalent salt coions does not lead to charge overcompensation of the surface charges on the grafting electrode.The stretching of star brushes under an electric field in the presence of trivalent salt coions was also briefly investigated.展开更多
Technological advances in the past 30 years have boosted the use of PSM （membrane separation processes）, important for its efficiency and flexibility of operation. These processes can be used in many types of separa...Technological advances in the past 30 years have boosted the use of PSM （membrane separation processes）, important for its efficiency and flexibility of operation. These processes can be used in many types of separation, with some advantages over the usual separation processes. NF （nanofiltration） is a membrane separation technique, which has properties intermediate between reverse osmosis and ultrafiltration in terms of separated species, because the average of the pores is in the range of 1/2 to 10 nm, and the separation occurs in function of load and size of the species. Usually removes species in solution with an effective diameter of about 1 nm or larger and multivalent ions to a greater extent than monovalent ions. The objective was to study the formation of biofouling on the surface of commercial nanofiltration membrane （Osmonics/GE） and surface membrane synthesized in our laboratory. The study was conducted in permeation system with filtration cell with tangential displacement of 15 bar for 8 days flow. DBNPA （2,2-dibromo-3-nitrilopropionamide） was used as a biocide agent, and an anti-fouling, in concentrations of 5 and 300 ppm, respectively, added to the water coming from the Beach Sea Galleon, RJ. The results demonstrated that there was no change in the flow and rejection of sulphate ions, even in the presence of anti-fouling. The count of aerobic, anaerobic and BRS （sulfate reducing bacteria） in seawater before and after using the DBNPA showed efficiency in controlling these groups of microorganisms and biofouling microbial consortium consisting of the existing in seawater.展开更多
文摘The prominent role Ca^2＋ ion plays as a major small biological messenger is fascinating. There are many physiologically important ions, such as Na^＋, K^＋, H^＋, Cl^-, Ca^2＋, Mg2＋, Fe^3＋, and PO4^3- that participate in cell signaling. Among them, monovalent ions primarily contribute to rapid electrical signaling, while multivalent ions generally act as a co-factor for chemical reactions by associating with the host molecule through electrostatic or covalent interactions. Ca^2＋ plays both roles. Its transmembrane influx supports the plateau phase of cardiac action potential and helps set the speed of pacemaker potential.
基金supported by the National Research Fund for Fundamental Key Projects(2019YFA070870)the National Natural Science Foundation of China(22090052,21988102)+1 种基金the Frontier Science Key Projects of CAS(ZDBS-LY-SLH022)the Key R&D Project of Shandong Province(2022CXGC010302)。
基金supported by the Joint Funds of the National Natural Science Foundation of China(U22A20140)the Independent Cultivation Program of Innovation Team of Ji’nan City(2019GXRC011)the National Natural Science Foundation of China(62001189)。
基金supported by the National Natural Science Foundation of China (No.21774067)the support from K. C. Wong Magna Fund in Ningbo University。
文摘Langevin dynamics simulations were conducted to study the collapse of grafted partially charged 4-arm star chains onto the oppositely charged grafting electrode in the presence of trivalent salt coions.Simulation results reveal that the average charge fraction of the grafted star chains and the salt concentration play critical roles in the competitive adsorption of charged monomers and trivalent salt coions onto the oppositely charged electrode.For grafted star chains with relatively high charge fraction,charged monomers are the dominant species collapsing on the oppositely charged electrode with the emergence of charge reversal on the grafting electrode.At a low charge fraction such that the total amount of charges on a grafted star molecule is comparable to that of a trivalent salt coion,trivalent salt coions absorb more strongly onto the electrode than grafted stars even at very low salt concentration.It is found that at relatively low charge fraction of star chains,the addition of trivalent salt coions does not lead to charge overcompensation of the surface charges on the grafting electrode.The stretching of star brushes under an electric field in the presence of trivalent salt coions was also briefly investigated.
文摘Technological advances in the past 30 years have boosted the use of PSM （membrane separation processes）, important for its efficiency and flexibility of operation. These processes can be used in many types of separation, with some advantages over the usual separation processes. NF （nanofiltration） is a membrane separation technique, which has properties intermediate between reverse osmosis and ultrafiltration in terms of separated species, because the average of the pores is in the range of 1/2 to 10 nm, and the separation occurs in function of load and size of the species. Usually removes species in solution with an effective diameter of about 1 nm or larger and multivalent ions to a greater extent than monovalent ions. The objective was to study the formation of biofouling on the surface of commercial nanofiltration membrane （Osmonics/GE） and surface membrane synthesized in our laboratory. The study was conducted in permeation system with filtration cell with tangential displacement of 15 bar for 8 days flow. DBNPA （2,2-dibromo-3-nitrilopropionamide） was used as a biocide agent, and an anti-fouling, in concentrations of 5 and 300 ppm, respectively, added to the water coming from the Beach Sea Galleon, RJ. The results demonstrated that there was no change in the flow and rejection of sulphate ions, even in the presence of anti-fouling. The count of aerobic, anaerobic and BRS （sulfate reducing bacteria） in seawater before and after using the DBNPA showed efficiency in controlling these groups of microorganisms and biofouling microbial consortium consisting of the existing in seawater.
