BACKGROUND Orthopedic implant-related infection remains one of the most serious complications after orthopedic surgery.In recent years,there has been an increased scientific interest to improve prevention and treatmen...BACKGROUND Orthopedic implant-related infection remains one of the most serious complications after orthopedic surgery.In recent years,there has been an increased scientific interest to improve prevention and treatment strategies.However,many of these strategies have focused on chemical measures.AIM To analyze the effect of alternating current electrical fields on bacterial adherence to titanium surfaces.METHODS Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)were exposed to 6.5 V electrical currents at different frequencies:0.5 Hz,0.1 Hz,and 0.05 Hz.After exposure,a bacterial count was then performed and compared to the control model.Other variables registered included the presence of electrocoagulation of the medium,electrode oxidation and/or corrosion,and changes in pH of the medium.RESULTS The most effective electrical model for reducing S.aureus adhesion was 6.5 V alternating current at 0.05 Hz achieving a 90%adhesion reduction rate.For E.coli,the 0.05 Hz frequency model also showed the most effective results with a 53%adhesion reduction rate,although these were significantly lower than S.aureus.Notable adhesion reduction rates were observed for S.aureus and E.coli in the studied conditions.However,the presence of electrode oxidation makes us presume these conditions are not optimal for in vivo use.CONCLUSION Although our findings suggest electrical currents may be useful in preventing bacterial adhesion to metal surfaces,further research using other electrical conditions must be examined to consider their use for in vivo trials.展开更多
Various resting-state fMRI(R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the co...Various resting-state fMRI(R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity,voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation, which doesn't exist in phase randomized surrogate data. As a measure of intrinsic brain function, concordance for R-fMRI indices was negatively correlated with age across individuals(i.e., concordance among functional indices decreased with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual(i.e., high vs. low concordance participants) or intra-individual(i.e., high vs.low concordance states identified via temporal dynamic analyses) differences. We also noted a linear increase in functional concordance together with the R-fMRI indices through the scan, which may suggest a decrease in arousal. The current study demonstrated an enriched picture regarding the relationship among the R-fMRI indices, as well as provided new insights in examining dynamic states within and between individuals.展开更多
基金the DIRECT project (Desarrollo de Nuevos Dispositivos Biomimé ticos Mejorados Superficialmente con Nuevos Recubrimientos y Tratamientos Físicos), which has been funded with a grant from the Centre for Development of Industrial Technology (CDTI)
文摘BACKGROUND Orthopedic implant-related infection remains one of the most serious complications after orthopedic surgery.In recent years,there has been an increased scientific interest to improve prevention and treatment strategies.However,many of these strategies have focused on chemical measures.AIM To analyze the effect of alternating current electrical fields on bacterial adherence to titanium surfaces.METHODS Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)were exposed to 6.5 V electrical currents at different frequencies:0.5 Hz,0.1 Hz,and 0.05 Hz.After exposure,a bacterial count was then performed and compared to the control model.Other variables registered included the presence of electrocoagulation of the medium,electrode oxidation and/or corrosion,and changes in pH of the medium.RESULTS The most effective electrical model for reducing S.aureus adhesion was 6.5 V alternating current at 0.05 Hz achieving a 90%adhesion reduction rate.For E.coli,the 0.05 Hz frequency model also showed the most effective results with a 53%adhesion reduction rate,although these were significantly lower than S.aureus.Notable adhesion reduction rates were observed for S.aureus and E.coli in the studied conditions.However,the presence of electrode oxidation makes us presume these conditions are not optimal for in vivo use.CONCLUSION Although our findings suggest electrical currents may be useful in preventing bacterial adhesion to metal surfaces,further research using other electrical conditions must be examined to consider their use for in vivo trials.
基金supported by the National Key R&D Program of China (2017YFC1309902 to CGY)National Basic Research Program (2015CB351702 to XNZ)+4 种基金the Natural Science Foundation of China (81671774 and 81630031 to CGY, 81471740, 81220108014 to XNZ)the Hundred Talents Program of the Chinese Academy of Sciences (Y5CX072006 to CGY)Beijing Municipal Science & Technology Commission (Z161100000216152 to CGY)the National Institutes of Health (U01MH099059 to MPM)the Child Mind Institute (1FDN2012-1 to MPM)
文摘Various resting-state fMRI(R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity,voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation, which doesn't exist in phase randomized surrogate data. As a measure of intrinsic brain function, concordance for R-fMRI indices was negatively correlated with age across individuals(i.e., concordance among functional indices decreased with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual(i.e., high vs. low concordance participants) or intra-individual(i.e., high vs.low concordance states identified via temporal dynamic analyses) differences. We also noted a linear increase in functional concordance together with the R-fMRI indices through the scan, which may suggest a decrease in arousal. The current study demonstrated an enriched picture regarding the relationship among the R-fMRI indices, as well as provided new insights in examining dynamic states within and between individuals.