Aim To evaluate the interactive effects of different self- adhesive resin cements and tribochemical treatment on bond strength to zirconia. Methodology The following self-adhesive resin cements for bonding two zirconi...Aim To evaluate the interactive effects of different self- adhesive resin cements and tribochemical treatment on bond strength to zirconia. Methodology The following self-adhesive resin cements for bonding two zirconia blocks were evaluated： Maxcem （MA）, Smartcem （SM）, Rely X Unicem Aplicap （UN）, Breeze （BR）, Biscem （BI）, Set （SE）, and Clearfil SA luting （CL）. The specimens were grouped according to conditioning as follows： Group 1, polishing with 600 grit polishing paper; Group 2, silica coating with 110 μm Al2O3 particles which modified with silica; and, Group 3, tribochemical treatment - silica coating ＋ silanization. Specimens were stored in distilled water at 37℃ for 24 hours before testing shear bond strength. Results Silica coating and tribochemical treatment significantly increased the bond strength of the MA, UN, BR, B1, SE and CL to zirconia compared to #600 polishing. For both #600 polished and silica coating treatments, MDP- containing self-adhesive resin cement CL had the highest bond strengths to zirconia. Conclusion Applying silica coating and tribochemical treatment improved the bond strength of self-adhesive resin cement to zirconia, especially for CL.展开更多
With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-he...With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.展开更多
Wound management is a crucial measure for skin wound healing and is significantly important to maintaining the integrity of skins and their functions.Electrical stimulation at the wound site is a compelling strategy f...Wound management is a crucial measure for skin wound healing and is significantly important to maintaining the integrity of skins and their functions.Electrical stimulation at the wound site is a compelling strategy for skin wound repair.However,there has been an urgent need for wearable and point-of-care electrical stimulation devices that have self-adhesive and mechanical properties comparable to wound tissue.Herein,we develop a bioinspired hybrid patch with self-adhesive and piezoelectric nanogenerator(HPSP)for promoting skin wound healing,which is composed of a mussel-inspired hydrogel matrix and a piezoelectric nanogenerator based on aligned electrospun poly(vinylidene fluoride)nanofibers.The device with optimized modulus and permeability for skin wear can self-adhere to the wound site and locally produce a dynamic voltage caused by motion.We show that the HPSP not only promotes fibroblast proliferation and migration in vitro,but also effectively facilitates the collagen deposition,angiogenesis,and re-epithelialization in vivo with the increased expressions of crucial growth factors.The HPSP reduces the wound closure time of full-thickness skin defects by about 1/3,greatly accelerating the healing process.This patch can serve as wearable and real-time electrical stimulation devices,potentially useful in clinical applications of skin wound healing.展开更多
Ionic hydrogel-based sensors have shined a spotlight on wearable electronics.However,the sensitivity and reliability of hydrogel devices are significantly hampered by the weak adhesion of skin-sensor interface as well...Ionic hydrogel-based sensors have shined a spotlight on wearable electronics.However,the sensitivity and reliability of hydrogel devices are significantly hampered by the weak adhesion of skin-sensor interface as well as inferior temperature tolerance.Here,inspired by the structure and composition of dermis,a novel skin-attachable and environment-stable hydrogel was designed by integrating collagen into the LiCl-containing chemically cross-linked polyacrylamide hydrogel.The hydrogel exhibited skin-like mechanical properties of low modulus,superior stretchability as well as excellent elasticity.Furthermore,the introduction of collagen endowed the hydrogel with robust and seamless interfaces with diverse materials,including the curved skin.As a result,the hydrogel is capable of serving as a human-machine interface for collecting reliable electrocardiography(ECG)signals and discerning various human motions,with high sensitivity(gauge factor=10.7),fast response,negligible hysteresis as well as extensive monitoring range.Notably,the hydrogel that can mimick the temperature-tolerant mechanism of most organisms possesses persistent stabilization of adhesive,conductive,sensory and mechanical performances at subzero or ambient conditions.The skin-inspired strategy paves an effective way for the design of multifunctional materials with potential applications in next-generation electronics.展开更多
The complexity of application environment stimulates the development of wearable devices based on functional hydrogels.Among all the promising performances,self-healing and self-adhesion properties are ideal for hydro...The complexity of application environment stimulates the development of wearable devices based on functional hydrogels.Among all the promising performances,self-healing and self-adhesion properties are ideal for hydrogel sensors,which can guarantee good accuracy,comfort and long service life.However,it is still a challenge to achieve simultaneous self-healing and self-adhesion in different environments(in the air,underwater and at low temperatures).Herein,a feasible new strategy was successfully carried out to prepare a starch-based composite conductive organohydrogel based on the reversible borate ester bonds formed by complexing starch/polyvinyl alcohol(PVA)/tea polyphenol(TP)with borax,and multiple hydrogen-bond interactions among PVA,starch,TP and ethylene glycol(EG).Silver nanoparticles(Ag-NPs),reduced and stabilized by TP,and MWCNTs(multi-walled carbon nanotubes)were introduced into the cross-linking networks to endow the resulting PBSTCE organohydrogel with considerable antibacterial property and conductivity,respectively.The organohydrogel possessed rapid self-healing(HE(self-healing efficiency)=96.07%in 90 s,both in the air and underwater,also at-20℃),considerable self-adhesion(both in the air and underwater,also at-20℃),remarkable stretchability(814%of elongation),anti-freezing(-20℃)and moisture-retention abilities,antibacterial activity,sensitive pH/sugar-responsiveness,and plasticity.The strain sensor formed by the PBSTCE organohydrogel can not only effectively record large-scale human motions(e.g.finger/wrist/elbow bending,walking,etc.),but also accurately capture subtle motion changes(e.g.breathing,chewing,swallowing,speaking,smiling and frowning).Moreover,the self-healed organohydrogel sensor also exhibited almost invariable mechanical,electrical and sensing behaviors.This work demonstrates a feasible strategy to construct multifunctional starch-based organohy-drogels,and promotes their efficient,stable and eco-friendly application as flexible wearable devices.展开更多
目的比较两种不同粘接系统用于玻璃纤维桩核修复的临床效果。方法选取136颗已行根管治疗的患牙随机分为自酸蚀Multilink N和自粘接Rely X Unicem两组,行玻璃纤维桩+全冠修复。分别在修复后进行随访观察,比较两组患牙的临床修复成功率。...目的比较两种不同粘接系统用于玻璃纤维桩核修复的临床效果。方法选取136颗已行根管治疗的患牙随机分为自酸蚀Multilink N和自粘接Rely X Unicem两组,行玻璃纤维桩+全冠修复。分别在修复后进行随访观察,比较两组患牙的临床修复成功率。结果修复后6、12、24月,两组成功率均在97%以上,且两组间比较差异无统计学意义(P>0.05)。结论 Multilink N自酸蚀树脂水门汀和RelyX Unicem自粘接树脂水门汀用于粘接纤维桩均能获得良好的临床修复效果。展开更多
目的评估2种类型复合树脂水门汀与E.MAX铸瓷全冠的3年临床粘接效果。方法对154名接受E.MAX铸瓷全冠修复的患者进行为期3年的随访,共计218件冠修复体,使用的树脂粘接系统包括自酸蚀类复合树脂水门汀PANAVIA F,需使用ED-Primer预处理基牙...目的评估2种类型复合树脂水门汀与E.MAX铸瓷全冠的3年临床粘接效果。方法对154名接受E.MAX铸瓷全冠修复的患者进行为期3年的随访,共计218件冠修复体,使用的树脂粘接系统包括自酸蚀类复合树脂水门汀PANAVIA F,需使用ED-Primer预处理基牙表面和自粘接类复合树脂水门汀Rely X Unicem,粘接前均使用硅烷偶联剂预处理冠内粘接面。3年观察期间出现的修复体脱落和折裂均记为失败。记录失败情况并计算成功率。结果E.MAX铸瓷全冠与PANAVIA F和Rely X Unieem粘接的3年保存率分别为97.5%和96.0%。脱落失败均出現在后牙区有大面积树脂充填物的基牙上。结论在3年观察期内,自酸蚀类和白粘接类复合树脂水门汀粘接的E.MAX铸瓷全冠临床表现良好。展开更多
文摘Aim To evaluate the interactive effects of different self- adhesive resin cements and tribochemical treatment on bond strength to zirconia. Methodology The following self-adhesive resin cements for bonding two zirconia blocks were evaluated： Maxcem （MA）, Smartcem （SM）, Rely X Unicem Aplicap （UN）, Breeze （BR）, Biscem （BI）, Set （SE）, and Clearfil SA luting （CL）. The specimens were grouped according to conditioning as follows： Group 1, polishing with 600 grit polishing paper; Group 2, silica coating with 110 μm Al2O3 particles which modified with silica; and, Group 3, tribochemical treatment - silica coating ＋ silanization. Specimens were stored in distilled water at 37℃ for 24 hours before testing shear bond strength. Results Silica coating and tribochemical treatment significantly increased the bond strength of the MA, UN, BR, B1, SE and CL to zirconia compared to #600 polishing. For both #600 polished and silica coating treatments, MDP- containing self-adhesive resin cement CL had the highest bond strengths to zirconia. Conclusion Applying silica coating and tribochemical treatment improved the bond strength of self-adhesive resin cement to zirconia, especially for CL.
基金support from the National Natural Science Foundation of China(61801525)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010693)+1 种基金the Guangdong Natural Science Funds Grant(2018A030313400),the Science and Technology Program of Guangzhou(201904010456)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(2021qntd09).
文摘With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.
基金We thank the funding support from the National Natural Science Foundation of China(Nos.51973075 and 51525302)Program for HUST Academic Frontier Youth Team(2015-01)The authors thank HUST Analytical and Testing Center for their supports on the facilities.
文摘Wound management is a crucial measure for skin wound healing and is significantly important to maintaining the integrity of skins and their functions.Electrical stimulation at the wound site is a compelling strategy for skin wound repair.However,there has been an urgent need for wearable and point-of-care electrical stimulation devices that have self-adhesive and mechanical properties comparable to wound tissue.Herein,we develop a bioinspired hybrid patch with self-adhesive and piezoelectric nanogenerator(HPSP)for promoting skin wound healing,which is composed of a mussel-inspired hydrogel matrix and a piezoelectric nanogenerator based on aligned electrospun poly(vinylidene fluoride)nanofibers.The device with optimized modulus and permeability for skin wear can self-adhere to the wound site and locally produce a dynamic voltage caused by motion.We show that the HPSP not only promotes fibroblast proliferation and migration in vitro,but also effectively facilitates the collagen deposition,angiogenesis,and re-epithelialization in vivo with the increased expressions of crucial growth factors.The HPSP reduces the wound closure time of full-thickness skin defects by about 1/3,greatly accelerating the healing process.This patch can serve as wearable and real-time electrical stimulation devices,potentially useful in clinical applications of skin wound healing.
基金supported by the National Natural Science Foundation of China (51873024)the Science and Technology Department of Jilin Province (20200708102YY and 20190201234JC)
文摘Ionic hydrogel-based sensors have shined a spotlight on wearable electronics.However,the sensitivity and reliability of hydrogel devices are significantly hampered by the weak adhesion of skin-sensor interface as well as inferior temperature tolerance.Here,inspired by the structure and composition of dermis,a novel skin-attachable and environment-stable hydrogel was designed by integrating collagen into the LiCl-containing chemically cross-linked polyacrylamide hydrogel.The hydrogel exhibited skin-like mechanical properties of low modulus,superior stretchability as well as excellent elasticity.Furthermore,the introduction of collagen endowed the hydrogel with robust and seamless interfaces with diverse materials,including the curved skin.As a result,the hydrogel is capable of serving as a human-machine interface for collecting reliable electrocardiography(ECG)signals and discerning various human motions,with high sensitivity(gauge factor=10.7),fast response,negligible hysteresis as well as extensive monitoring range.Notably,the hydrogel that can mimick the temperature-tolerant mechanism of most organisms possesses persistent stabilization of adhesive,conductive,sensory and mechanical performances at subzero or ambient conditions.The skin-inspired strategy paves an effective way for the design of multifunctional materials with potential applications in next-generation electronics.
基金This work is financed by the National Natural Science Founda-tion of China(No.21978180).We appreciate the valuable help of Dr.Jinwei Zhang from the College of Biomass Science and Engineering of Sichuan University and Hui Wang from the Analytical&Testing Center of Sichuan University.We thank eceshi(www.eceshi.com)for the great help in SEM analysis.
文摘The complexity of application environment stimulates the development of wearable devices based on functional hydrogels.Among all the promising performances,self-healing and self-adhesion properties are ideal for hydrogel sensors,which can guarantee good accuracy,comfort and long service life.However,it is still a challenge to achieve simultaneous self-healing and self-adhesion in different environments(in the air,underwater and at low temperatures).Herein,a feasible new strategy was successfully carried out to prepare a starch-based composite conductive organohydrogel based on the reversible borate ester bonds formed by complexing starch/polyvinyl alcohol(PVA)/tea polyphenol(TP)with borax,and multiple hydrogen-bond interactions among PVA,starch,TP and ethylene glycol(EG).Silver nanoparticles(Ag-NPs),reduced and stabilized by TP,and MWCNTs(multi-walled carbon nanotubes)were introduced into the cross-linking networks to endow the resulting PBSTCE organohydrogel with considerable antibacterial property and conductivity,respectively.The organohydrogel possessed rapid self-healing(HE(self-healing efficiency)=96.07%in 90 s,both in the air and underwater,also at-20℃),considerable self-adhesion(both in the air and underwater,also at-20℃),remarkable stretchability(814%of elongation),anti-freezing(-20℃)and moisture-retention abilities,antibacterial activity,sensitive pH/sugar-responsiveness,and plasticity.The strain sensor formed by the PBSTCE organohydrogel can not only effectively record large-scale human motions(e.g.finger/wrist/elbow bending,walking,etc.),but also accurately capture subtle motion changes(e.g.breathing,chewing,swallowing,speaking,smiling and frowning).Moreover,the self-healed organohydrogel sensor also exhibited almost invariable mechanical,electrical and sensing behaviors.This work demonstrates a feasible strategy to construct multifunctional starch-based organohy-drogels,and promotes their efficient,stable and eco-friendly application as flexible wearable devices.
文摘目的评估2种类型复合树脂水门汀与E.MAX铸瓷全冠的3年临床粘接效果。方法对154名接受E.MAX铸瓷全冠修复的患者进行为期3年的随访,共计218件冠修复体,使用的树脂粘接系统包括自酸蚀类复合树脂水门汀PANAVIA F,需使用ED-Primer预处理基牙表面和自粘接类复合树脂水门汀Rely X Unicem,粘接前均使用硅烷偶联剂预处理冠内粘接面。3年观察期间出现的修复体脱落和折裂均记为失败。记录失败情况并计算成功率。结果E.MAX铸瓷全冠与PANAVIA F和Rely X Unieem粘接的3年保存率分别为97.5%和96.0%。脱落失败均出現在后牙区有大面积树脂充填物的基牙上。结论在3年观察期内,自酸蚀类和白粘接类复合树脂水门汀粘接的E.MAX铸瓷全冠临床表现良好。
