Different functional polystyrenes were synthesized and the adsorptions of microcystin-LR onto those resins were monitored by quartz crystal microbalance-dissipation. Both adsorption pH and surface properties had a con...Different functional polystyrenes were synthesized and the adsorptions of microcystin-LR onto those resins were monitored by quartz crystal microbalance-dissipation. Both adsorption pH and surface properties had a considerable effect on the adsorption amount, while adsorption temperature was less significant. Ammonium polystyrene would be a better candidate for microcystin-LR adsorption at neutral pH conditions.展开更多
Grand canonical Monte Carlo and molecular dynamics simulation methods are used to simulate oxygen sorption and diffusion in amorphous poly（lactic acid） （PLA）. The simulated solubility coefficient of oxygen is clos...Grand canonical Monte Carlo and molecular dynamics simulation methods are used to simulate oxygen sorption and diffusion in amorphous poly（lactic acid） （PLA）. The simulated solubility coefficient of oxygen is close to experimental data obtained from the quartz crystal microbalance but much higher than those from the time-lag method. This discrepancy is explained by using the dual-mode sorption model. It is found that oxygen sorotion in PLA is predominantly Langmuir type controlled, i.e., through the process of filling holes. The time--lag method only takes into account oxygen molecules that participate the diffusion process whereas a large proportion of oxygen molecules trapped in the void have little chance to execute hopping due to the glassy nature of PLA at room temperature. The simulated diffusion coefficient of oxygen is reasonably close to the data obtained from the time-lag method. The solubility coefficient of oxygen decreases linearly with increasing relative humidity while its diffusion coefficient firstly decreases and then increases as a function of relative humidity.展开更多
The effect of salt concentration on layer-by-layer deposition of poly（sodium 4-styrene sulfonate） （PSSS）/poly（vinylbenzyl trimethylammonium chloride） （PVTC） was investigated by use of quartz crystal microbalan...The effect of salt concentration on layer-by-layer deposition of poly（sodium 4-styrene sulfonate） （PSSS）/poly（vinylbenzyl trimethylammonium chloride） （PVTC） was investigated by use of quartz crystal microbalance with dissipation （QCM-D）. The changes in frequency and dissipation demonstrate that the addition of NaC1 leads the thickness of PSSS/PVTC multilayer to increase. The deposition of PSSS/PVTC is dominated by surface charge overcompensation level at lower salt concentrations. However, it is mainly determined by the interpenetration of polyelectrolytes at a higher salt concentration, as reflected in the oscillation of dissipation change.展开更多
The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen...The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation （QCM-D） in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.展开更多
To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-...To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-Lys-Gly-D-Ala-D-Ala） was investigated by flow injection surface plasmon resonance （FI-SPR） and flow injection quartz crystal microbalance （FI-QCM）. To facilitate the formation of a compact vancomycin adsorbates layer with a uniform surface orientation, vancomycin molecules were attached onto a preformed alkanethiol self-assembled monolayer. By optimizing the conditions for the binding between Lys-Lys-Gly-D-Ala-D-Ala and vancomycin on the assembled chip, the detecting limit of Lys-Lys-Gly-D-Ala-D-Ala was greatly improved （reaching 0.5 ×10^- 6 mol/L or 7.5 × 10^-12 mol）. The equilibrium constant of the association of Lys-Lys-Gly-D-Ala-D-Ala with vancomycin was also obtained （KAds=5.0×10^4 L/tool）.展开更多
基金This work was supported by the Foundation for scholar of Hefei Normal University （No.2014rcjj03）, the Foundations of Educational Committee of Anhui Province （No.KJ2014A205）, the National Natural Science Foundation of China （No.21101053, No.21101054, No.20934004, No.91127046, and No.20874094）, the One Hundred Talent Project of Chinese Academy of Sciences, and the National Basic Research Program of China （No.2012CB821500 and No.2010CB934500）.
文摘Different functional polystyrenes were synthesized and the adsorptions of microcystin-LR onto those resins were monitored by quartz crystal microbalance-dissipation. Both adsorption pH and surface properties had a considerable effect on the adsorption amount, while adsorption temperature was less significant. Ammonium polystyrene would be a better candidate for microcystin-LR adsorption at neutral pH conditions.
基金Supported by Program of New Century Excellent Talents in University （NCET-07-0313）, the National Natural Science Foun- dation of China （20706019, 20876052）, Guangdong Science Foundation （$2011010002078）.
文摘Grand canonical Monte Carlo and molecular dynamics simulation methods are used to simulate oxygen sorption and diffusion in amorphous poly（lactic acid） （PLA）. The simulated solubility coefficient of oxygen is close to experimental data obtained from the quartz crystal microbalance but much higher than those from the time-lag method. This discrepancy is explained by using the dual-mode sorption model. It is found that oxygen sorotion in PLA is predominantly Langmuir type controlled, i.e., through the process of filling holes. The time--lag method only takes into account oxygen molecules that participate the diffusion process whereas a large proportion of oxygen molecules trapped in the void have little chance to execute hopping due to the glassy nature of PLA at room temperature. The simulated diffusion coefficient of oxygen is reasonably close to the data obtained from the time-lag method. The solubility coefficient of oxygen decreases linearly with increasing relative humidity while its diffusion coefficient firstly decreases and then increases as a function of relative humidity.
基金This work was supported by the National Natural Science Foundation of China （No.20474060）.
文摘The effect of salt concentration on layer-by-layer deposition of poly（sodium 4-styrene sulfonate） （PSSS）/poly（vinylbenzyl trimethylammonium chloride） （PVTC） was investigated by use of quartz crystal microbalance with dissipation （QCM-D）. The changes in frequency and dissipation demonstrate that the addition of NaC1 leads the thickness of PSSS/PVTC multilayer to increase. The deposition of PSSS/PVTC is dominated by surface charge overcompensation level at lower salt concentrations. However, it is mainly determined by the interpenetration of polyelectrolytes at a higher salt concentration, as reflected in the oscillation of dissipation change.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.9732011CB606200 and No.81330031） and Fundamentat Research Funds for the Central Universities （No.SWJTU11CX054）. The authors gratefully acknowledge assistance of Mr. Hai-bei Liu at Qsense company for consulting.
文摘The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation （QCM-D） in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.
基金Projects(20773165,20876179) supported by the National Natural Science Foundation of ChinaProject(09JJ1002) supported by the Hunan Provincial Natural Science Foundation,China+1 种基金Project(NCET-07-0865) for New Century Excellent Talents in Chinese UniversityProject(2007AA022006) supported by the National High Technology Research and Development Program of China
文摘To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-Lys-Gly-D-Ala-D-Ala） was investigated by flow injection surface plasmon resonance （FI-SPR） and flow injection quartz crystal microbalance （FI-QCM）. To facilitate the formation of a compact vancomycin adsorbates layer with a uniform surface orientation, vancomycin molecules were attached onto a preformed alkanethiol self-assembled monolayer. By optimizing the conditions for the binding between Lys-Lys-Gly-D-Ala-D-Ala and vancomycin on the assembled chip, the detecting limit of Lys-Lys-Gly-D-Ala-D-Ala was greatly improved （reaching 0.5 ×10^- 6 mol/L or 7.5 × 10^-12 mol）. The equilibrium constant of the association of Lys-Lys-Gly-D-Ala-D-Ala with vancomycin was also obtained （KAds=5.0×10^4 L/tool）.
