Introduction: Bracket debonding is a frequent issue that clinicians encounter, leading to increased chair time, lost revenue, and material usage. In addition to patient compliance with their diet recommendations, the ...Introduction: Bracket debonding is a frequent issue that clinicians encounter, leading to increased chair time, lost revenue, and material usage. In addition to patient compliance with their diet recommendations, the preparation and conditioning of teeth for bonding significantly influence bond strength and consequently impact orthodontic treatment success and efficiency. Because of OBA-MCP’s (orthodontic bonding adhesive with modified calcium phosphate) decreased shear bond strength (SBS), the purpose of this study was to evaluate the effects of conditioning with 5.25% sodium hypochlorite (NaOCl) before etching in the bonding protocol. Materials and Methods: 90 extracted teeth were divided into 3 groups to be bonded with orthodontic brackets with different bonding protocols: 1) Transbond XT with regular bonding protocol (etch + prime + adhesive);2) OBA-MCP with regular bonding protocol;and 3) OBA-MCP with NaOCl prior to acid etching in the regular bonding protocol. SBS (in Newtons) were measured using an MTS universal testing machine with a custom jig to apply a vertical force onto the bracket and ARI (adhesive remnant index) scores were recorded for each sample after de-bond to rate the amount of adhesive remaining. Results: The addition of NaOCl to the bonding protocol statistically significantly increased the SBS of OBA-MCP to comparable levels to Transbond XT. The ARI scores showed that when NaOCl was added, more adhesive remained. Conclusion: The addition of NaOCl to the bonding protocol can increase the SBS of adhesives with historically weaker bond strengths. However, the increased amount of adhesive remaining and the increased time spent during bonding must be considered. Further testing can be done in vivo to demonstrate the practicality of this new procedure.展开更多
A unilateral self-locking mechanism(USM) was proposed to increase the tractive ability of the inchworm in-pipe robots for pipeline inspection.The USM was basically composed of a cam,a torsional spring and an axis.The ...A unilateral self-locking mechanism(USM) was proposed to increase the tractive ability of the inchworm in-pipe robots for pipeline inspection.The USM was basically composed of a cam,a torsional spring and an axis.The self-locking and virtual work principles were applied to studying the basic self-locking condition of the USM.In order to make the cooperation between the crutch and telescopic mechanism more harmonical,the unlocking time of the USM was calculated.A set of parameters were selected to build a virtual model and fabricate a prototype.Both the simulation and performance experiments were carried out in a pipe with a nominal inside diameter of 160 mm.The results show that USM enables the robot to move quickly in one way,and in the other way it helps the robot get self-locking with the pipe wall.The traction of the inchworm robot can rise to 1.2 kN,beyond the limitation of friction of 0.497 kN.展开更多
BACKGROUND Cervical degenerative disc(CDD)disease is a common type of spondylosis.Although anterior cervical discectomy and fusion(ACDF)is the preferred treatment for CDD disease,internal fixation with a titanium plat...BACKGROUND Cervical degenerative disc(CDD)disease is a common type of spondylosis.Although anterior cervical discectomy and fusion(ACDF)is the preferred treatment for CDD disease,internal fixation with a titanium plate may cause various complications.The invention of the ACDF with a self-locking fusion cage(ROI-C)has effectively decreased the incidence of postoperative complications.AIM To observe the outcomes of CDD disease treated by ACDF with a ROI-C.METHODS Ninety patients with CDD disease treated at our hospital from March 2019 to March 2021 were included.They were divided into two groups(control group and observation group,n=45 in each)using a random number table.Patients in the control group received ACDF plus internal fixation with a titanium plate.Those in the observation group received ACDF+ROI-C placement.The two groups of patients were compared in terms of surgical parameters,pain,cervical spine function,range of motion,and complications.RESULTS The two groups of patients showed no significant differences in surgical time,blood loss,drainage volume,and length of hospital stay(P>0.05).No significant differences in the visual analogue scale(VAS),Japanese Orthopedic Association(JOA),and neck disability index(NDI)scores were observed between the two groups before surgery(P>0.05).The VAS and NDI scores in the observation group were considerably lower than those in the control group after surgery;however,the JOA scores in the observation group were significantly higher than those in the control group(P<0.05).No significant differences were observed in cervical disc height and the range of motion of the superior or inferior adjacent vertebrae between the two groups before surgery(P>0.05).The disc height in the observation group was larger than that in the control group after surgery.The range of motion of both the superior and inferior adjacent vertebrae was significantly smaller in the observation group than in the control group(P<0.05).The incidence of complications was only 2.22% in the observation group compared to 15.56% in the control group,and the difference was statistically significant(P<0.05).CONCLUSION Cervical spine function restoration was better with ROI-C with internal fixation in ACDF than with conventional titanium plates in ACDF for CDD disease.展开更多
Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various die...Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.展开更多
With the increasing global demand for renewable energy,solar photovoltaic power generation technology has been widely applied in China and even globally.Especially in mountainous areas,complex terrain resources are cl...With the increasing global demand for renewable energy,solar photovoltaic power generation technology has been widely applied in China and even globally.Especially in mountainous areas,complex terrain resources are cleverly utilized in the construction of photovoltaic power stations,but this also brings severe challenges to the anti-corrosion of photovoltaic brackets.This paper focuses on the anti-corrosion technology of mountain photovoltaic brackets,and deeply explores the influence of natural factors such as mountain climate,sandstorms,and precipitation on the corrosion of photovoltaic brackets.The research results show that the key to improving anti-corrosion performance lies in the selection of bracket materials and optimization of coating processes.After comparing various anti-corrosion treatment methods such as hot-dip galvanizing,spray aluminum coating,and new anti-corrosion materials,it is found that nano coating technology exhibits excellent protective effects in corrosive environments.This study is of great significance for promoting the sustainable development of photovoltaic power generation,providing solid theoretical support and practical guidance for the anti-corrosion design of mountain photovoltaic power stations.展开更多
With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses seve...With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses severe challenges to the design and optimization of solar photovoltaic brackets.Traditional design methods are difficult to cope with the changeable wind speed and direction in mountainous areas,resulting in structural instability or material waste.Researchers have identified the key factors affecting wind response through parametric research and dynamic wind response analysis,so as to optimize the brackets design and improve its adaptability and stability in complex wind environments.In this paper,the complexity of wind speed,wind direction and turbulence characteristics in mountainous areas and their influence on brackets design are explored.Through static and dynamic wind load analysis,the geometrical shape and material selection of the bracket are optimized to enhance its wind resistance.The application of multi-objective optimization model and intelligent optimization algorithm provides an effective solution for the design of solar photovoltaic brackets,ensuring their safety and reliability in complex wind environments.展开更多
The Bracket Set(dougong)is an important aspect of traditional Chinese architecture known for its exquisite structure,complexity,and rich variations.This design element has been used since the Qin and Han Dynasties and...The Bracket Set(dougong)is an important aspect of traditional Chinese architecture known for its exquisite structure,complexity,and rich variations.This design element has been used since the Qin and Han Dynasties and is still prevalent today.It highlights hierarchy and spiritual connotations in the design of a building.This article explores the application of Bracket Set elements in modern architectural design.It analyzes the specific application strategies of this design element,highlighting its value in modern architecture.The goal is to provide modern architectural designers with multiple perspectives and strategies to fully utilize the advantages of Bracket Set elements in architectural design and enhance the artistic value of their work.展开更多
文摘Introduction: Bracket debonding is a frequent issue that clinicians encounter, leading to increased chair time, lost revenue, and material usage. In addition to patient compliance with their diet recommendations, the preparation and conditioning of teeth for bonding significantly influence bond strength and consequently impact orthodontic treatment success and efficiency. Because of OBA-MCP’s (orthodontic bonding adhesive with modified calcium phosphate) decreased shear bond strength (SBS), the purpose of this study was to evaluate the effects of conditioning with 5.25% sodium hypochlorite (NaOCl) before etching in the bonding protocol. Materials and Methods: 90 extracted teeth were divided into 3 groups to be bonded with orthodontic brackets with different bonding protocols: 1) Transbond XT with regular bonding protocol (etch + prime + adhesive);2) OBA-MCP with regular bonding protocol;and 3) OBA-MCP with NaOCl prior to acid etching in the regular bonding protocol. SBS (in Newtons) were measured using an MTS universal testing machine with a custom jig to apply a vertical force onto the bracket and ARI (adhesive remnant index) scores were recorded for each sample after de-bond to rate the amount of adhesive remaining. Results: The addition of NaOCl to the bonding protocol statistically significantly increased the SBS of OBA-MCP to comparable levels to Transbond XT. The ARI scores showed that when NaOCl was added, more adhesive remained. Conclusion: The addition of NaOCl to the bonding protocol can increase the SBS of adhesives with historically weaker bond strengths. However, the increased amount of adhesive remaining and the increased time spent during bonding must be considered. Further testing can be done in vivo to demonstrate the practicality of this new procedure.
基金Project(2007AA04Z256) supported by the National High-Tech Research and Development Program of China
文摘A unilateral self-locking mechanism(USM) was proposed to increase the tractive ability of the inchworm in-pipe robots for pipeline inspection.The USM was basically composed of a cam,a torsional spring and an axis.The self-locking and virtual work principles were applied to studying the basic self-locking condition of the USM.In order to make the cooperation between the crutch and telescopic mechanism more harmonical,the unlocking time of the USM was calculated.A set of parameters were selected to build a virtual model and fabricate a prototype.Both the simulation and performance experiments were carried out in a pipe with a nominal inside diameter of 160 mm.The results show that USM enables the robot to move quickly in one way,and in the other way it helps the robot get self-locking with the pipe wall.The traction of the inchworm robot can rise to 1.2 kN,beyond the limitation of friction of 0.497 kN.
文摘BACKGROUND Cervical degenerative disc(CDD)disease is a common type of spondylosis.Although anterior cervical discectomy and fusion(ACDF)is the preferred treatment for CDD disease,internal fixation with a titanium plate may cause various complications.The invention of the ACDF with a self-locking fusion cage(ROI-C)has effectively decreased the incidence of postoperative complications.AIM To observe the outcomes of CDD disease treated by ACDF with a ROI-C.METHODS Ninety patients with CDD disease treated at our hospital from March 2019 to March 2021 were included.They were divided into two groups(control group and observation group,n=45 in each)using a random number table.Patients in the control group received ACDF plus internal fixation with a titanium plate.Those in the observation group received ACDF+ROI-C placement.The two groups of patients were compared in terms of surgical parameters,pain,cervical spine function,range of motion,and complications.RESULTS The two groups of patients showed no significant differences in surgical time,blood loss,drainage volume,and length of hospital stay(P>0.05).No significant differences in the visual analogue scale(VAS),Japanese Orthopedic Association(JOA),and neck disability index(NDI)scores were observed between the two groups before surgery(P>0.05).The VAS and NDI scores in the observation group were considerably lower than those in the control group after surgery;however,the JOA scores in the observation group were significantly higher than those in the control group(P<0.05).No significant differences were observed in cervical disc height and the range of motion of the superior or inferior adjacent vertebrae between the two groups before surgery(P>0.05).The disc height in the observation group was larger than that in the control group after surgery.The range of motion of both the superior and inferior adjacent vertebrae was significantly smaller in the observation group than in the control group(P<0.05).The incidence of complications was only 2.22% in the observation group compared to 15.56% in the control group,and the difference was statistically significant(P<0.05).CONCLUSION Cervical spine function restoration was better with ROI-C with internal fixation in ACDF than with conventional titanium plates in ACDF for CDD disease.
文摘Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.
文摘With the increasing global demand for renewable energy,solar photovoltaic power generation technology has been widely applied in China and even globally.Especially in mountainous areas,complex terrain resources are cleverly utilized in the construction of photovoltaic power stations,but this also brings severe challenges to the anti-corrosion of photovoltaic brackets.This paper focuses on the anti-corrosion technology of mountain photovoltaic brackets,and deeply explores the influence of natural factors such as mountain climate,sandstorms,and precipitation on the corrosion of photovoltaic brackets.The research results show that the key to improving anti-corrosion performance lies in the selection of bracket materials and optimization of coating processes.After comparing various anti-corrosion treatment methods such as hot-dip galvanizing,spray aluminum coating,and new anti-corrosion materials,it is found that nano coating technology exhibits excellent protective effects in corrosive environments.This study is of great significance for promoting the sustainable development of photovoltaic power generation,providing solid theoretical support and practical guidance for the anti-corrosion design of mountain photovoltaic power stations.
文摘With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses severe challenges to the design and optimization of solar photovoltaic brackets.Traditional design methods are difficult to cope with the changeable wind speed and direction in mountainous areas,resulting in structural instability or material waste.Researchers have identified the key factors affecting wind response through parametric research and dynamic wind response analysis,so as to optimize the brackets design and improve its adaptability and stability in complex wind environments.In this paper,the complexity of wind speed,wind direction and turbulence characteristics in mountainous areas and their influence on brackets design are explored.Through static and dynamic wind load analysis,the geometrical shape and material selection of the bracket are optimized to enhance its wind resistance.The application of multi-objective optimization model and intelligent optimization algorithm provides an effective solution for the design of solar photovoltaic brackets,ensuring their safety and reliability in complex wind environments.
文摘The Bracket Set(dougong)is an important aspect of traditional Chinese architecture known for its exquisite structure,complexity,and rich variations.This design element has been used since the Qin and Han Dynasties and is still prevalent today.It highlights hierarchy and spiritual connotations in the design of a building.This article explores the application of Bracket Set elements in modern architectural design.It analyzes the specific application strategies of this design element,highlighting its value in modern architecture.The goal is to provide modern architectural designers with multiple perspectives and strategies to fully utilize the advantages of Bracket Set elements in architectural design and enhance the artistic value of their work.
