Herein,we fabricated a flexible semidry electrode with excellent mechanical performance,satisfactory self-adhesiveness,and low-contact impedance using physical/chemical crosslinked polyvinyl alcohol/polyacrylamide dua...Herein,we fabricated a flexible semidry electrode with excellent mechanical performance,satisfactory self-adhesiveness,and low-contact impedance using physical/chemical crosslinked polyvinyl alcohol/polyacrylamide dual-network hydrogels(PVA/PAM DNHs)as an efficient saline reservoir.The resultant PVA/PAM DNHs showed admirable adhesive and compliance to the hairy scalp,facilitating the establishment of a robust electrode/skin interface for biopotential signal transmission.Moreover,the PVA/PAM DNHs steadily released trace saline onto the scalp to achieve the minimized potential drift(1.47±0.39 mV/min)and low electrode–scalp impedance(18.2±8.9 kΩ@10 Hz).More importantly,the application feasibility of real-world brain−computer interfaces(BCIs)was preliminarily validated by 10 participants using two classic BCI paradigms.The mean temporal cross-correlation coefficients between the semidry and wet electrodes in the eyes open/closed and the N200 speller paradigms are 0.919±0.054 and 0.912±0.050,respectively.Both electrodes demonstrate anticipated neuroelectrophysiological responses with similar patterns.This semidry electrode could also effectively capture robust P-QRS-T peaks during electrocardiogram recording.Considering their outstanding advantages of fast setup,user-friendliness,and robust signals,the proposed PVA/PAM DNH-based electrode is a promising alternative to wet electrodes in biopotential signal acquisition.展开更多
The effective Lagrangian of a finite volume system should, in principle, depend on the system size. In the framework of the Nambu-Jona-Lasinio(NJL) model, by considering the influence of quark feedback on the effectiv...The effective Lagrangian of a finite volume system should, in principle, depend on the system size. In the framework of the Nambu-Jona-Lasinio(NJL) model, by considering the influence of quark feedback on the effective coupling, we obtain a modified NJL model so that its Lagrangian depends on the volume. Based on the modified NJL model, we study the influence of finite volume on the chiral phase transition at finite temperature, and find that the pseudo-critical temperature of crossover is much lower than that obtained in the normal NJL model. This clearly shows that the volume dependent effective Lagrangian plays an important role in the chiral phase transitions at finite temperature.展开更多
At extremely high temperature T~200 Me V and low chemical potentialμ,the quarks and gluons get released from the nucleon and form the quark-gluon plasma(QGP)state,which is accessible in the heavy ion collisions(HIC)...At extremely high temperature T~200 Me V and low chemical potentialμ,the quarks and gluons get released from the nucleon and form the quark-gluon plasma(QGP)state,which is accessible in the heavy ion collisions(HIC)globally[1,2].Theoretically,ab initio lattice QCD simulation found the transition from hadrons to QGP at lowμis continuous crossover instead of phase transition.In this connection,RHIC is running the beam energy scan program to look into the territory with higherμ[3].One important goal is to determine if there is the first order phase transition as expected by many model studies and locate the critical end point(CEP)if it exists.展开更多
When an orthopedics device is implanted into bone injury site, it will contact the soft tissue (skeletal muscle, fascia, ligament etc.) except for bone. Magnesium based biodegradable metals are becoming an important...When an orthopedics device is implanted into bone injury site, it will contact the soft tissue (skeletal muscle, fascia, ligament etc.) except for bone. Magnesium based biodegradable metals are becoming an important research object in orthopedics due to their bioactivity to promote bone healing. In this study, pure Mg rods with and without chemical conversion coating were implanted into the muscle tissue of rabbits. Implants and their surrounding tissues were taken out for weight loss measurement, cross- sectional scanning electron microscopy observation, elemental distribution analysis and histological examination. The results showed that the chemical conversion coating would increase the in vivo cor- rosion resistance of pure Mg and decrease the accumulation of calcium (Ca) and phosphorus (P) elements around the implants. For the bare magnesium implant, both Ca and P contents in the surrounding tissues increased at the initial stage of implantation and then decreased at 12 weeks implantation, while for the magnesium with chemical conversion coating, Ca and P contents in the surrounding tissues de- creased with the implantation time, but were not significant. The histological results demonstrated that there was no calcification in the muscle tissue with implantation of magnesium for up to 12 weeks. The chemical conversion coating not only increased the in vivo corrosion resistance of pure Mg, but also avoided the depositions of Ca and P in the surrounding tissues, meaning that pure magnesium should be biosafe when contacting with muscle tissues,展开更多
基金supported by the National Natural Science Foundation of China (Nos.62176089,61703152)the Hunan Provincial Natural Science Foundation (Nos.2021JJ30226,2018JJ3134)+1 种基金Scientific Research Foundation of Hunan Provincial Education Department (No.21B0532)Science and Technology Planning Project of Zhuzhou (No.2020015).
文摘Herein,we fabricated a flexible semidry electrode with excellent mechanical performance,satisfactory self-adhesiveness,and low-contact impedance using physical/chemical crosslinked polyvinyl alcohol/polyacrylamide dual-network hydrogels(PVA/PAM DNHs)as an efficient saline reservoir.The resultant PVA/PAM DNHs showed admirable adhesive and compliance to the hairy scalp,facilitating the establishment of a robust electrode/skin interface for biopotential signal transmission.Moreover,the PVA/PAM DNHs steadily released trace saline onto the scalp to achieve the minimized potential drift(1.47±0.39 mV/min)and low electrode–scalp impedance(18.2±8.9 kΩ@10 Hz).More importantly,the application feasibility of real-world brain−computer interfaces(BCIs)was preliminarily validated by 10 participants using two classic BCI paradigms.The mean temporal cross-correlation coefficients between the semidry and wet electrodes in the eyes open/closed and the N200 speller paradigms are 0.919±0.054 and 0.912±0.050,respectively.Both electrodes demonstrate anticipated neuroelectrophysiological responses with similar patterns.This semidry electrode could also effectively capture robust P-QRS-T peaks during electrocardiogram recording.Considering their outstanding advantages of fast setup,user-friendliness,and robust signals,the proposed PVA/PAM DNH-based electrode is a promising alternative to wet electrodes in biopotential signal acquisition.
基金Supported by the National Natural Science Foundation of China(11475085,11535005,11690030)the National Major state Basic Research and Development(2016YFE0129300)
文摘The effective Lagrangian of a finite volume system should, in principle, depend on the system size. In the framework of the Nambu-Jona-Lasinio(NJL) model, by considering the influence of quark feedback on the effective coupling, we obtain a modified NJL model so that its Lagrangian depends on the volume. Based on the modified NJL model, we study the influence of finite volume on the chiral phase transition at finite temperature, and find that the pseudo-critical temperature of crossover is much lower than that obtained in the normal NJL model. This clearly shows that the volume dependent effective Lagrangian plays an important role in the chiral phase transitions at finite temperature.
基金supported by the National Natural Science Foundation of China(Grant Nos.11475085,11535005,11690030,and 51405027)the China Postdoctoral Science Foundation(Grant No.2016M591808)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.020414380074)the Major State Basic Research and Development Program of China(Grant No.2016YFE0129300)
文摘At extremely high temperature T~200 Me V and low chemical potentialμ,the quarks and gluons get released from the nucleon and form the quark-gluon plasma(QGP)state,which is accessible in the heavy ion collisions(HIC)globally[1,2].Theoretically,ab initio lattice QCD simulation found the transition from hadrons to QGP at lowμis continuous crossover instead of phase transition.In this connection,RHIC is running the beam energy scan program to look into the territory with higherμ[3].One important goal is to determine if there is the first order phase transition as expected by many model studies and locate the critical end point(CEP)if it exists.
基金financially supported by the National Science & Technology Pillar Program of China (No. 2012BAI18B01)the National Basic Research Program of China ("973 Program", No. 2012CB619101)+1 种基金the National Natural Science Foundation of China (No. 81171443)the Foundation of Jiangsu Collaborative Innovation Center of Biomedical Functional Materials
文摘When an orthopedics device is implanted into bone injury site, it will contact the soft tissue (skeletal muscle, fascia, ligament etc.) except for bone. Magnesium based biodegradable metals are becoming an important research object in orthopedics due to their bioactivity to promote bone healing. In this study, pure Mg rods with and without chemical conversion coating were implanted into the muscle tissue of rabbits. Implants and their surrounding tissues were taken out for weight loss measurement, cross- sectional scanning electron microscopy observation, elemental distribution analysis and histological examination. The results showed that the chemical conversion coating would increase the in vivo cor- rosion resistance of pure Mg and decrease the accumulation of calcium (Ca) and phosphorus (P) elements around the implants. For the bare magnesium implant, both Ca and P contents in the surrounding tissues increased at the initial stage of implantation and then decreased at 12 weeks implantation, while for the magnesium with chemical conversion coating, Ca and P contents in the surrounding tissues de- creased with the implantation time, but were not significant. The histological results demonstrated that there was no calcification in the muscle tissue with implantation of magnesium for up to 12 weeks. The chemical conversion coating not only increased the in vivo corrosion resistance of pure Mg, but also avoided the depositions of Ca and P in the surrounding tissues, meaning that pure magnesium should be biosafe when contacting with muscle tissues,