Molecular dynamics simulations based on AMBER force fields(ff96 and ff03) and generalized Born models(igb1 and igb5) have been carried out in order to study folding/unfolding of the Trp-cage mini-protein TC5b.The ther...Molecular dynamics simulations based on AMBER force fields(ff96 and ff03) and generalized Born models(igb1 and igb5) have been carried out in order to study folding/unfolding of the Trp-cage mini-protein TC5b.The thermodynamic properties of TC5b were found to be sensitive to the specific version of the solvation model and force field employed.When the ff96/igb5 combination was used,the predicted melting temperature from unfolding simulations was in good agreement with the experimental value of 315 K,but the folding simulation did not converge.The most stable thermodynamic profile in both folding and unfolding simulations was obtained when the ff03/igb5 combination was employed,and the predicted melting temperature was about 345 K,showing over-stabilization of the protein.Simulations using the igb1 version in combination with ff96 or ff03 were difficult to converge within the simulation time limit(50 ns).展开更多
Ti-6Al-4V(TC4)used in dentistry and orthopedics as implant biomaterial faces the risk of microbiologically influenced corrosion(MIC)owing to the residence of diverse oral microorganisms.Hereinto,Streptococcus mutans i...Ti-6Al-4V(TC4)used in dentistry and orthopedics as implant biomaterial faces the risk of microbiologically influenced corrosion(MIC)owing to the residence of diverse oral microorganisms.Hereinto,Streptococcus mutans is a critical pathogenic microorganism that causes dental caries.This work investigated the corrosive effects of S.mutans on TC4 and functional gradient TC4/TC4-5Cu coupons fabricated by selective laser melting(SLM)through various electrochemical measurements,surface examination,observation of biofilm and corrosion analysis.The results indicated that the Cu-bearing alloy showed an inhibitory effect on the biofilms due to the release of Cu element,thereby reducing the corrosion rate of MIC.The corrosion current density(icorr)of TC4(11.7±0.8)nA cm−2 is higher than that of TC4/TC4-5Cu(7.4±0.4)nA cm−2 in the presence of S.mutans,while the maximum pit depth of TC4 is 1.6 times that of TC4/TC4-5Cu.Therefore,metal modification through Cu alloying is an effective strategy to improve the MIC resistance.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2004CB719901)the National Natural Science Foundation of China (Grants No.10874104,20773060)the Natural Science Foundation of Shandong Province (Grant No.Z2007A05)
文摘Molecular dynamics simulations based on AMBER force fields(ff96 and ff03) and generalized Born models(igb1 and igb5) have been carried out in order to study folding/unfolding of the Trp-cage mini-protein TC5b.The thermodynamic properties of TC5b were found to be sensitive to the specific version of the solvation model and force field employed.When the ff96/igb5 combination was used,the predicted melting temperature from unfolding simulations was in good agreement with the experimental value of 315 K,but the folding simulation did not converge.The most stable thermodynamic profile in both folding and unfolding simulations was obtained when the ff03/igb5 combination was employed,and the predicted melting temperature was about 345 K,showing over-stabilization of the protein.Simulations using the igb1 version in combination with ff96 or ff03 were difficult to converge within the simulation time limit(50 ns).
基金supported by the National Natural Science Foundation of China(No.52301091)the Medical Engineering Intersection Joint Funds of the Natural Science Foundation of Liaoning Province of China(No.2022-YGJC-01).
文摘Ti-6Al-4V(TC4)used in dentistry and orthopedics as implant biomaterial faces the risk of microbiologically influenced corrosion(MIC)owing to the residence of diverse oral microorganisms.Hereinto,Streptococcus mutans is a critical pathogenic microorganism that causes dental caries.This work investigated the corrosive effects of S.mutans on TC4 and functional gradient TC4/TC4-5Cu coupons fabricated by selective laser melting(SLM)through various electrochemical measurements,surface examination,observation of biofilm and corrosion analysis.The results indicated that the Cu-bearing alloy showed an inhibitory effect on the biofilms due to the release of Cu element,thereby reducing the corrosion rate of MIC.The corrosion current density(icorr)of TC4(11.7±0.8)nA cm−2 is higher than that of TC4/TC4-5Cu(7.4±0.4)nA cm−2 in the presence of S.mutans,while the maximum pit depth of TC4 is 1.6 times that of TC4/TC4-5Cu.Therefore,metal modification through Cu alloying is an effective strategy to improve the MIC resistance.
