Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate a...Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.展开更多
The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and...The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and calibration of radiation monitoring instruments in a secondary standard dosimetry laboratory. In Nigeria, the suboptimal performances of these instruments are attributed to inadequate maintenance practices, insufficient calibration, and limited awareness of proper equipment handling for optimal use. This study assesses the current practices related to the optimal use, maintenance, repair, and calibration of radiation detection equipment across Nigeria’s six geopolitical zones. Using a cross-sectional survey approach, data were collected from Ninety (90) radiation monitoring equipment operators, Radiation Safety Officers, and frontline responders to evaluate their knowledge, awareness, and practices concerning equipment usage, operation, storage, handling, and calibration. The findings reveal significant gaps in knowledge of usage (trained is 43.2%, not trained is 56.8%) and inconsistencies in maintenance practices (as indicated by the regression analysis (β = 0.51, p < 0.01), particularly regarding specialized instruments such as the PackEye, Mobile Detection System (MDS), Radionuclide Identifinder (RID), and Personal Radiation Detectors (PRD). While there is high awareness of the need for regular calibration and handling training, the lack of standardized protocols and training alignment poses challenges to the effective use of these instruments. This study underscores the importance of comprehensive training programs, standardized maintenance protocols, and enhanced awareness initiatives to optimize the usage, performance and safety of radiation monitoring instruments in Nigeria.展开更多
Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from Jan...Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from January to October 2024,and quality nursing activities were implemented in the management of reusable instruments.The completion of quality indicators was analyzed.The instrument quality management scores,department satisfaction,and nurses’professional ability scores before and after nursing management were compared.Results:After nursing intervention,the qualified rates of initial cleaning and final cleaning of sterilization instruments were 99.66%and 100%,respectively.The qualified rate of packaging was 99.97%,the wet package rate was 0.1‰,the loading qualified rate was 99.88%,and the qualified rate of distribution was 99.99%.After nursing intervention,the nurses’instrument quality management scores,department satisfaction,and nurses’professional ability scores were all higher than those before nursing intervention(P<0.05).Conclusion:Quality nursing activities can improve the cleaning,packaging,and sterilization qualified rates of reusable instruments in the CSSD,enhance the effect of instrument quality management,obtain higher department satisfaction from nurses,cultivate their professional abilities,and possess significant nursing management advantages.展开更多
The in-flight instrumental background of the Follow-up X-ray Telescope(FXT)onboard Einstein Probe mis sion is analysed in this work by utilizing observations collected during the performance verification phase and sub...The in-flight instrumental background of the Follow-up X-ray Telescope(FXT)onboard Einstein Probe mis sion is analysed in this work by utilizing observations collected during the performance verification phase and subsequent dedicated filter wheel closed observations.The instrumental backgrounds of the two FXT modules are consistent with each other,with an average rate of~4×10^(-2)counts s^(-1)keV^(-1)in the 0.5-10 keV band for each module.The background is nearly uniformly distributed across the detector area,with a minor increase(<8%)observed along rows.The spatial distribution shows significant modulation by the geomagnetic field.The spectral shapes remain unchanged in 0.5-10 keV at different rates.The long-term temporal variation indicates a periodic change associated with the orbital precession(~57 days).The innovative design of FXT full-frame readout mode enables simultaneous recording of events in both the imaging area(IMG)and the frame store area(FSA)of the pnCCD.FSA event rates show a strong linear correlation with the IMG,based on which the IMG instrumental background modeling is established.展开更多
The efficacy requirements of cosmetic instruments and explored their efficacy evaluation methods was investigated.The efficacy and claims of common cosmetic instruments on the market were investigated,and human clinic...The efficacy requirements of cosmetic instruments and explored their efficacy evaluation methods was investigated.The efficacy and claims of common cosmetic instruments on the market were investigated,and human clinical trials were conducted to evaluate the efficacy of household cosmetic instruments.Household cosmetic instruments mainly include technologies such as sound wave,ion conduction,LED light,EMS microcurrent,RF radio frequency,and laser.This paper took microcurrent as an example to explore its efficacy claim methods.In human test I,the water content in the stratum corneum of the forearms of 31 subjects increased significantly compared with the blank control after 8 h.In human test II,30 subjects showed significant decreases in skin texture R5,transepidermal water loss TEWL,skin firmness F4 value,skin elasticity R2 value,overall size and depth of facial wrinkles,and facial jawline angle,and a significant increase in facial gloss value.The results showed that the cosmetic instrument had effects of moisturizing,improving facial evenness,repairing barrier,improving skin elasticity and firmness,and improving facial edema.展开更多
Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decade...Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decades of development,the current MAAC engineering lacks highly robust specialized instruments,which limits the further industrial application of the MAAC process.Herein,to guide the design and optimization of the advanced MAAC instrument(DUT-iMC),we developed a parameter evaluation strategy based on cold model experiments.This approach utilizes the average particle size variation rate and the counts variation rate to characterize crystal size changes.The layout of the internal membrane module in DUT-iMC and the arrangement of the conveying pipeline were optimized.This improvement enhanced particle conveying characteristics,promoting more efficienttransport and circulation within the module.The advanced MAAC instrument substantially automates the production process,and the internal probes accurately monitor and record process variables,allowing for precise regulation of crystal size and morphology.The optimal operating range was expanded by 150%compared to the laboratory instrument.The range of shell side flow rate options increased by 50%,and the production time can be shortened by up to 30%.This paper provides ideas and guidance for the industrialization of MAAC processes and the development of related instruments.展开更多
This study examined the development of technician teams on large-scale instrument platforms in universities,using the State Key Laboratory of Natural and Biomimetic Drugs in the Peking University School of Pharmaceuti...This study examined the development of technician teams on large-scale instrument platforms in universities,using the State Key Laboratory of Natural and Biomimetic Drugs in the Peking University School of Pharmaceutical Sciences as a case study.Data were collected through questionnaire surveys and interviews conducted in 2017,followed by a questionnaire survey in 2023,offering both subjective and objective insights.The evolution of the platform’s technician team over the past 5 years was analyzed,highlighting key experiences and identifying ongoing challenges.Recommendations to enhance technician team development include recruiting skilled faculty,clearly defining job responsibilities,and refining the assessment and incentive systems.展开更多
This paper introduces the key design aspects of automotive center console instrument systems,including hardware architecture,ergonomics,antenna layout,etc.It elaborates on the application and advantages of various adv...This paper introduces the key design aspects of automotive center console instrument systems,including hardware architecture,ergonomics,antenna layout,etc.It elaborates on the application and advantages of various advanced technologies,such as 3D printing and dual-color injection molding.Additionally,it discusses advancements in structural design,as well as future challenges and the trend of multidisciplinary collaborative innovation.展开更多
BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation...BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation failure is poor bone quality.On the other hand,some evidence suggests that surgical tactics can influence long-term instrumentation stability.AIM To assess factors that influence the stability of spinal instrumentation in patients with thoracolumbar injuries.METHODS This study is a non-randomized single center ambispective evaluation of 204 consecutive patients(117 men;87 women)with unstable thoracolumbar injuries.All patients underwent either stand-alone or combined with anterior column reconstruction instrumentation.In cases with spinal cord and nerve root injuries,either posterior or anterior decompression were performed.Patients with pedicle screw loosening were identified via computed tomography imaging.Out of those,cases with clinically significant instrumentation failure were registered.RESULTS The rate of pedicle screw loosening detected by computed tomography was inversely correlated with bone radiodensity figures and an increased association with the number of instrumented levels,residual kyphotic deformity,laminectomy,and lumbosacral fixation.Intermediate screws and anterior reconstruction were associated with a clinically relevant decreased risk of pedicle screw loosening development.Either complete or partial posterior fusion within instrumented levels was capable of decreasing instrumentation failure risk,while extensive decompression with laminectomy and at least one-level total facetectomy were associated with an increased risk of instrumentation failure.Anterior decompression does not have a negative impact on instrumentation stability.CONCLUSION Intermediate screws,anterior reconstruction and posterior tension band preservation are associated with decreased rates of instrumentation instability development.Posterior fusion is beneficial in terms of instrumentation failure prevention.展开更多
The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-se...The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.展开更多
Aiming at node deployment in the monitoring area of the field observation instrument network in the cold and arid regions,we propose a virtual force algorithm based on Voronoi diagram(VFAVD),which adopts probabilistic...Aiming at node deployment in the monitoring area of the field observation instrument network in the cold and arid regions,we propose a virtual force algorithm based on Voronoi diagram(VFAVD),which adopts probabilistic sensing model that is more in line with the actual situation.First,the Voronoi diagram is constructed in the monitoring area to determine the Thiessen polygon of each node.Then,the virtual force on each node is calculated,and the node update its position according to the direction and size of the total force,so as to achieve the purpose of improving the network coverage rate.The simulation results show that the proposed algorithm can effectively improve the coverage rate of the network,and also has a good effect on the coverage uniformity.展开更多
On April 6th,the"Silk Road People-to-People Connectivity"China-Cambodia Traditional Instrument Concert was successfully held in Phnom Penh.The event was attended by Li Ji,Cultural Counsellor of the Chinese E...On April 6th,the"Silk Road People-to-People Connectivity"China-Cambodia Traditional Instrument Concert was successfully held in Phnom Penh.The event was attended by Li Ji,Cultural Counsellor of the Chinese Embassy in Cambodia,officials from Ministry of Culture and Fine Arts of Cambodia and Ministry of Commerce of Cambodia,along with vips from various sectors.展开更多
Objective:To evaluate and compare the quality of life(QoL)in patients with multidrug-resistant(MDR-TB)and drug-sensitive(DS-TB)as well as to investigate factors associated with QoL among MDR-TB patients in real-world ...Objective:To evaluate and compare the quality of life(QoL)in patients with multidrug-resistant(MDR-TB)and drug-sensitive(DS-TB)as well as to investigate factors associated with QoL among MDR-TB patients in real-world scenarios at the Haji Hospital,Surabaya.Methods:We conducted a case-control study from June to December 2024.MDR-TB and DS-TB patients were classified into case and control groups,respectively.We used the World Health Organization’s Quality of Life Brief(WHOQOL-BREF)instrument and Patient Health Questionnaire-9(PHQ-9)to assess QoL and depression levels,respectively.Multivariate analysis was used to analyze factors associated with QoL of patients with MDR-TB.Results:Forty-one patients with MDR-TB and 43 with DS-TB were enrolled in the study.A mean score for all domains(physical,psychological,social relationship,environmental)and total mean score of WHOQOL-BREF was significantly lower in MDR-TB than those with DS-TB(P<0.05).The prevalence of depression and the mean score of PHQ-9 were significantly higher in MDR-TB than in DS-TB(P<0.05).PHQ-9 negatively correlates with the WHOQOL-BREF score(r=-0.502,P<0.05)among MDR-TB patients.MDR-TB patients with depression were significantly associated with low QoL in the physical(OR 3.611;95%CI 2.393-6.951;P=0.029),psychological(OR 1.672;95%CI 1.179-5.941;P=0.021),social relationship(OR 2.586;95%CI 1.611-2.909;P=0.014),and environmental domains(OR 1.926;95%CI 1.047-2.147;P=0.048).Conclusions:MDR-TB patients had worse QoL than DS-TB.Those with depression were associated with low QoL.Strategies that identify and tackle alterations in the QoL for MDR-TB patients are necessary during TB treatment.展开更多
The research topic of the author’s PhD dissertation is“The Impact of Motivation Cultivation on English Autonomous Learning among University Students in Hunan,China—A Mediating Role of Learning Strategy.”Within thi...The research topic of the author’s PhD dissertation is“The Impact of Motivation Cultivation on English Autonomous Learning among University Students in Hunan,China—A Mediating Role of Learning Strategy.”Within this topic,three key variables are identified:the dependent variable(DV),the independent variable(IV),and the mediating variable(MV).Specifically,the DV refers to English autonomous learning,the IV refers to motivation,and the MV refers to learning strategy.The research establishes that the MV(learning strategy)is an integral component of information processing theory(IPT).Consequently,the dissertation incorporates integrative and instrumental motivation theories alongside IPT as its foundational theoretical framework.This paper aims to explore the theoretical framework of the PhD dissertation in detail,focusing on the interplay of these three theories.展开更多
Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method br...Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.展开更多
Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and m...Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and method of the classical control theory to analyze this temperature control system, and establishes mathematics model. According to mathematics model the text demonstrated the system at S field and time- area, and proposed optimizing basis to the total mark of proportion and differential parameter to con- troller PID, thus proposed a kind of temperature control scheme. And the thermostatically system is simulated by MATLAB.展开更多
Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estim...Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estimate the azimuth angle and the gyro constant drift in the paper. The relative errors which affect the estimation accuracy of the azimuth angle are the analysed.展开更多
文摘Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.
文摘The response and performance of radiation detectors for accurate measurements and effective use for radiological safety in medical, industrial, and nuclear sectors are based on the optimal use, maintenance, repair and calibration of radiation monitoring instruments in a secondary standard dosimetry laboratory. In Nigeria, the suboptimal performances of these instruments are attributed to inadequate maintenance practices, insufficient calibration, and limited awareness of proper equipment handling for optimal use. This study assesses the current practices related to the optimal use, maintenance, repair, and calibration of radiation detection equipment across Nigeria’s six geopolitical zones. Using a cross-sectional survey approach, data were collected from Ninety (90) radiation monitoring equipment operators, Radiation Safety Officers, and frontline responders to evaluate their knowledge, awareness, and practices concerning equipment usage, operation, storage, handling, and calibration. The findings reveal significant gaps in knowledge of usage (trained is 43.2%, not trained is 56.8%) and inconsistencies in maintenance practices (as indicated by the regression analysis (β = 0.51, p < 0.01), particularly regarding specialized instruments such as the PackEye, Mobile Detection System (MDS), Radionuclide Identifinder (RID), and Personal Radiation Detectors (PRD). While there is high awareness of the need for regular calibration and handling training, the lack of standardized protocols and training alignment poses challenges to the effective use of these instruments. This study underscores the importance of comprehensive training programs, standardized maintenance protocols, and enhanced awareness initiatives to optimize the usage, performance and safety of radiation monitoring instruments in Nigeria.
文摘Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from January to October 2024,and quality nursing activities were implemented in the management of reusable instruments.The completion of quality indicators was analyzed.The instrument quality management scores,department satisfaction,and nurses’professional ability scores before and after nursing management were compared.Results:After nursing intervention,the qualified rates of initial cleaning and final cleaning of sterilization instruments were 99.66%and 100%,respectively.The qualified rate of packaging was 99.97%,the wet package rate was 0.1‰,the loading qualified rate was 99.88%,and the qualified rate of distribution was 99.99%.After nursing intervention,the nurses’instrument quality management scores,department satisfaction,and nurses’professional ability scores were all higher than those before nursing intervention(P<0.05).Conclusion:Quality nursing activities can improve the cleaning,packaging,and sterilization qualified rates of reusable instruments in the CSSD,enhance the effect of instrument quality management,obtain higher department satisfaction from nurses,cultivate their professional abilities,and possess significant nursing management advantages.
基金supported by Strategic Priority Program on Space Science of Chinese Academy of Sciences,in collaboration with ESA,MPE and CNES(grant Nos.XDA15310303,XDA15310103 and XDA15052100)。
文摘The in-flight instrumental background of the Follow-up X-ray Telescope(FXT)onboard Einstein Probe mis sion is analysed in this work by utilizing observations collected during the performance verification phase and subsequent dedicated filter wheel closed observations.The instrumental backgrounds of the two FXT modules are consistent with each other,with an average rate of~4×10^(-2)counts s^(-1)keV^(-1)in the 0.5-10 keV band for each module.The background is nearly uniformly distributed across the detector area,with a minor increase(<8%)observed along rows.The spatial distribution shows significant modulation by the geomagnetic field.The spectral shapes remain unchanged in 0.5-10 keV at different rates.The long-term temporal variation indicates a periodic change associated with the orbital precession(~57 days).The innovative design of FXT full-frame readout mode enables simultaneous recording of events in both the imaging area(IMG)and the frame store area(FSA)of the pnCCD.FSA event rates show a strong linear correlation with the IMG,based on which the IMG instrumental background modeling is established.
文摘The efficacy requirements of cosmetic instruments and explored their efficacy evaluation methods was investigated.The efficacy and claims of common cosmetic instruments on the market were investigated,and human clinical trials were conducted to evaluate the efficacy of household cosmetic instruments.Household cosmetic instruments mainly include technologies such as sound wave,ion conduction,LED light,EMS microcurrent,RF radio frequency,and laser.This paper took microcurrent as an example to explore its efficacy claim methods.In human test I,the water content in the stratum corneum of the forearms of 31 subjects increased significantly compared with the blank control after 8 h.In human test II,30 subjects showed significant decreases in skin texture R5,transepidermal water loss TEWL,skin firmness F4 value,skin elasticity R2 value,overall size and depth of facial wrinkles,and facial jawline angle,and a significant increase in facial gloss value.The results showed that the cosmetic instrument had effects of moisturizing,improving facial evenness,repairing barrier,improving skin elasticity and firmness,and improving facial edema.
基金financial contribution from the National Natural Science Foundation of China(22021005,22378041)Supporting Plan of Scientificand Technology Innovative Talents in Dalian(2023RJ001)Central Guidance on Local Science and Technology Development Fund of Liaoning Province(2025040052-JH6/1011)。
文摘Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decades of development,the current MAAC engineering lacks highly robust specialized instruments,which limits the further industrial application of the MAAC process.Herein,to guide the design and optimization of the advanced MAAC instrument(DUT-iMC),we developed a parameter evaluation strategy based on cold model experiments.This approach utilizes the average particle size variation rate and the counts variation rate to characterize crystal size changes.The layout of the internal membrane module in DUT-iMC and the arrangement of the conveying pipeline were optimized.This improvement enhanced particle conveying characteristics,promoting more efficienttransport and circulation within the module.The advanced MAAC instrument substantially automates the production process,and the internal probes accurately monitor and record process variables,allowing for precise regulation of crystal size and morphology.The optimal operating range was expanded by 150%compared to the laboratory instrument.The range of shell side flow rate options increased by 50%,and the production time can be shortened by up to 30%.This paper provides ideas and guidance for the industrialization of MAAC processes and the development of related instruments.
文摘This study examined the development of technician teams on large-scale instrument platforms in universities,using the State Key Laboratory of Natural and Biomimetic Drugs in the Peking University School of Pharmaceutical Sciences as a case study.Data were collected through questionnaire surveys and interviews conducted in 2017,followed by a questionnaire survey in 2023,offering both subjective and objective insights.The evolution of the platform’s technician team over the past 5 years was analyzed,highlighting key experiences and identifying ongoing challenges.Recommendations to enhance technician team development include recruiting skilled faculty,clearly defining job responsibilities,and refining the assessment and incentive systems.
文摘This paper introduces the key design aspects of automotive center console instrument systems,including hardware architecture,ergonomics,antenna layout,etc.It elaborates on the application and advantages of various advanced technologies,such as 3D printing and dual-color injection molding.Additionally,it discusses advancements in structural design,as well as future challenges and the trend of multidisciplinary collaborative innovation.
基金Supported by AI For Spinal Surgery Planning and Results Assessment Project under the“Priority 2030”Academic Leadership Initiative,No.6.18-01/240724-15.
文摘BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation failure is poor bone quality.On the other hand,some evidence suggests that surgical tactics can influence long-term instrumentation stability.AIM To assess factors that influence the stability of spinal instrumentation in patients with thoracolumbar injuries.METHODS This study is a non-randomized single center ambispective evaluation of 204 consecutive patients(117 men;87 women)with unstable thoracolumbar injuries.All patients underwent either stand-alone or combined with anterior column reconstruction instrumentation.In cases with spinal cord and nerve root injuries,either posterior or anterior decompression were performed.Patients with pedicle screw loosening were identified via computed tomography imaging.Out of those,cases with clinically significant instrumentation failure were registered.RESULTS The rate of pedicle screw loosening detected by computed tomography was inversely correlated with bone radiodensity figures and an increased association with the number of instrumented levels,residual kyphotic deformity,laminectomy,and lumbosacral fixation.Intermediate screws and anterior reconstruction were associated with a clinically relevant decreased risk of pedicle screw loosening development.Either complete or partial posterior fusion within instrumented levels was capable of decreasing instrumentation failure risk,while extensive decompression with laminectomy and at least one-level total facetectomy were associated with an increased risk of instrumentation failure.Anterior decompression does not have a negative impact on instrumentation stability.CONCLUSION Intermediate screws,anterior reconstruction and posterior tension band preservation are associated with decreased rates of instrumentation instability development.Posterior fusion is beneficial in terms of instrumentation failure prevention.
基金support from the National Natural Science Foundation of China(Grant Nos.12172332,11727803 and 12072009)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ23A020007)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-C2022003).
文摘The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.
基金supported by National Natural Science Foundation of China(No.61862038)Lanzhou Talent Innovation and Entrepreneurship Technology Plan Project(No.2019-RC-14).
文摘Aiming at node deployment in the monitoring area of the field observation instrument network in the cold and arid regions,we propose a virtual force algorithm based on Voronoi diagram(VFAVD),which adopts probabilistic sensing model that is more in line with the actual situation.First,the Voronoi diagram is constructed in the monitoring area to determine the Thiessen polygon of each node.Then,the virtual force on each node is calculated,and the node update its position according to the direction and size of the total force,so as to achieve the purpose of improving the network coverage rate.The simulation results show that the proposed algorithm can effectively improve the coverage rate of the network,and also has a good effect on the coverage uniformity.
文摘On April 6th,the"Silk Road People-to-People Connectivity"China-Cambodia Traditional Instrument Concert was successfully held in Phnom Penh.The event was attended by Li Ji,Cultural Counsellor of the Chinese Embassy in Cambodia,officials from Ministry of Culture and Fine Arts of Cambodia and Ministry of Commerce of Cambodia,along with vips from various sectors.
文摘Objective:To evaluate and compare the quality of life(QoL)in patients with multidrug-resistant(MDR-TB)and drug-sensitive(DS-TB)as well as to investigate factors associated with QoL among MDR-TB patients in real-world scenarios at the Haji Hospital,Surabaya.Methods:We conducted a case-control study from June to December 2024.MDR-TB and DS-TB patients were classified into case and control groups,respectively.We used the World Health Organization’s Quality of Life Brief(WHOQOL-BREF)instrument and Patient Health Questionnaire-9(PHQ-9)to assess QoL and depression levels,respectively.Multivariate analysis was used to analyze factors associated with QoL of patients with MDR-TB.Results:Forty-one patients with MDR-TB and 43 with DS-TB were enrolled in the study.A mean score for all domains(physical,psychological,social relationship,environmental)and total mean score of WHOQOL-BREF was significantly lower in MDR-TB than those with DS-TB(P<0.05).The prevalence of depression and the mean score of PHQ-9 were significantly higher in MDR-TB than in DS-TB(P<0.05).PHQ-9 negatively correlates with the WHOQOL-BREF score(r=-0.502,P<0.05)among MDR-TB patients.MDR-TB patients with depression were significantly associated with low QoL in the physical(OR 3.611;95%CI 2.393-6.951;P=0.029),psychological(OR 1.672;95%CI 1.179-5.941;P=0.021),social relationship(OR 2.586;95%CI 1.611-2.909;P=0.014),and environmental domains(OR 1.926;95%CI 1.047-2.147;P=0.048).Conclusions:MDR-TB patients had worse QoL than DS-TB.Those with depression were associated with low QoL.Strategies that identify and tackle alterations in the QoL for MDR-TB patients are necessary during TB treatment.
基金Swan College of Central South University of Forestry and Technology Teaching Reform Research Project“The Impact of Teachers’Task-Based Teaching Method on English Interpreting Learning among University Students in Hunan,China”(SWXYJGPJ27)Swan College of Central South University of Forestry and Technology Scientific Research Project“The Impact of Integrative Motivation and Instrumental Motivation on English Autonomous Learning among University Students in Hunan,China--A Mediating Role of Learning Strategy”(SYXY202441)。
文摘The research topic of the author’s PhD dissertation is“The Impact of Motivation Cultivation on English Autonomous Learning among University Students in Hunan,China—A Mediating Role of Learning Strategy.”Within this topic,three key variables are identified:the dependent variable(DV),the independent variable(IV),and the mediating variable(MV).Specifically,the DV refers to English autonomous learning,the IV refers to motivation,and the MV refers to learning strategy.The research establishes that the MV(learning strategy)is an integral component of information processing theory(IPT).Consequently,the dissertation incorporates integrative and instrumental motivation theories alongside IPT as its foundational theoretical framework.This paper aims to explore the theoretical framework of the PhD dissertation in detail,focusing on the interplay of these three theories.
文摘Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.
文摘Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and method of the classical control theory to analyze this temperature control system, and establishes mathematics model. According to mathematics model the text demonstrated the system at S field and time- area, and proposed optimizing basis to the total mark of proportion and differential parameter to con- troller PID, thus proposed a kind of temperature control scheme. And the thermostatically system is simulated by MATLAB.
文摘Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estimate the azimuth angle and the gyro constant drift in the paper. The relative errors which affect the estimation accuracy of the azimuth angle are the analysed.
