Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environment...Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environmental impacts.This study reviews the remarkable benefits of check dams on the land reclamation and environmental improvement on the Loess Plateau,and sediment reduction entering the Yellow River.However,the flood incidents on check dams have been frequently reported for the past decades,which has attracted more attention in the context of climate change and extreme rainfall events recently.Advances in the flood migration techniques achieved by the research group led by the first author have been highlighted to migrate the breach risk of check dams due to floods.The“family tree method”has been proposed to determine the survival status and critical rainfall threshold of each check dam in the complicated dam system.An updated dam breach flood evaluation framework and the corresponding numerical algorithm(i.e.,DB-IWHR)have been developed.Moreover,innovative types of water-release facilities for check dams,including geobag stepped spillway and prestressed concrete cylinder pipe in the underlying conduit,have been proposed and developed.Finally,the perspectives concerning the check dam construction on the Loess Plateau have been put forward.展开更多
BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymoly...BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymolysis gauze(refers to sterile gauze soaked in a multi-enzyme cleaning solution)reduces bacterial air pollution in endoscopy rooms.AIM To evaluate the efficacy of an enzymolysis gauze cover in reducing bacterial aerosols from the biopsy valve.METHODS This prospective,single-blind trial included 80 patients undergoing elective diagnostic colonoscopy.During the procedure,the biopsy hole check valve was either covered or left uncovered with enzymolysis gauze.Air samples(100 L)were collected at a distance of 30 cm from the biopsy hole check valve and approximately 140 cm above the floor using a percussive air sampling instrument.Gram-positive bacteria were cultured on standard 90 mm colimycin nalidixic agar blood plates.The primary outcome measures were bacterial load and species identification.RESULTS Covering the biopsy hole check valve with enzymolysis gauze reduced bacterial load near the check valve from 50 colony-forming unit(CFU)/m^(3)[interquartile range(IQR):30-80]to 20 CFU/m^(3)(IQR:10-20).At the end of the procedure each day,covering the valve also decreased bacterial load in the endoscopy room from 35 CFU/m^(3)(IQR:33-85)to 10 CFU/m^(3)(IQR:5-10).The predominant bacteria identified were Gram-positive cocci.CONCLUSION Applying enzymolysis gauze to cover the biopsy hole check valve significantly reduces bacterial aerosol contamination in endoscopy rooms during colonoscopy.展开更多
The implementation of the cascade check dam system, which integrates beam and closed-type dams, has been extensively adopted as a pivotal engineering measure for mitigating debris flow in Southwest China. In the post-...The implementation of the cascade check dam system, which integrates beam and closed-type dams, has been extensively adopted as a pivotal engineering measure for mitigating debris flow in Southwest China. In the post-debris flow events, it is imperative to quantitatively assess the volume of sediment volume captured by the cascade check dams and to monitor their impact on sediment dynamics. This study investigates the cascade check dams in Guanmenzi Gully, Beichuan County, Sichuan Province in Southwest China, surveying the reservoir topography of the dams on two occasions over a fiveyear period. The #3 closed-type dam, located in the upper upstream, the #2 closed-type dam, located in the middle stream(which was manually cleaned), and the beam dam, located in the downstream were all surveyed. A simplified yet accurate method was developed to estimate sediment volume within check dam reservoirs under complex topographic conditions. A combination of terrestrial surveys and Unmanned Aerial Vehicle(UAV) based surveys was employed, resulting in the acquisition of two high-resolution Digital Elevation Models(DEMs) at different temporal intervals. The utilization of DEMs of Difference(DoD) facilitated the quantification of terrain variations and the sediment transport. The following conclusions were obtained: firstly, it was found that the volume of sediment trapped in the reservoirs of #2 closed-type dam and #1 beam dam were almost the same, with #3 closed-type dam being the smallest. The validation of the results in conjunction with the geometric method demonstrated that the percentage error was less than 7%, proving the reliability of the results. In addition, an analysis of changes in the detailed topography of the reservoirs revealed that the sediment deposit occurred in areas distant from the structures, while erosion exhibited concentration in specific areas close to the dams. The percentage volume of sediment deposit was found to be significantly higher than that of erosion(all higher than 85%). Furthermore, the excessive sediment deposition reduces the storage capacity of closed-type check dams, whereas in the case of beam dams, the maximum erosion amount in the reservoir is 35.8 m^(3) and the percentage of the maximum erosion amount is 14.00%. This suggests that the self-cleaning of beam dam can effectively slow down the sediment deposition process. Finally, the current study proposes an expression for storage capacity composition and suggests that, in engineering practice, emphasis should be placed on maintenance programs that synergize manual cleaning and self-cleaning of open-type check dams. The conclusions may facilitate the refinement of maintenance strategies of cascade check dams, thereby effectively preventing and mitigating debris flows.展开更多
In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge...In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge is introduced into the past tense operator, and then a new temporal epistemic logic LTLKP is obtained, so that LTLKP can naturally and precisely describe the system＇s reliability. Secondly, a set of prior algorithms are designed to calculate the maximal reachable depth and the length of the longest of loop free paths in the structure based on the graph structure theory. Finally, some theorems are proposed to show how to approximate the complete threshold with the diameter and recurrence diameter. The proposed work resolves the completeness threshold problem so that the completeness of bounded model checking can be guaranteed.展开更多
目的探讨美国心脏协会的My Life Check在线评估系统对冠心病患者健康生活方式干预的影响以及其在心脏健康指数评价中的应用效果。方法将心内科随诊的121例冠心病患者用随机数字表分成两组,观察组63例、对照组58例,两组均使用My Life Ch...目的探讨美国心脏协会的My Life Check在线评估系统对冠心病患者健康生活方式干预的影响以及其在心脏健康指数评价中的应用效果。方法将心内科随诊的121例冠心病患者用随机数字表分成两组,观察组63例、对照组58例,两组均使用My Life Check其中的Life’s simple 7调查表进行心脏健康调查,观察组根据My Life Check给出的相应健康生活方式指导措施进行干预,对照组常规宣教,并于1个月后对两组患者再次进行心脏健康指数评估。结果观察组及对照组干预后心脏健康指数均明显高于干预前(P<0.05),但干预后观察组较对照组心脏健康指数改善更明显(P<0.05)。结论 My Life Check评估干预能有效改善冠心病患者的健康生活方式。展开更多
基金National Natural Science Foundation of China,Grant/Award Number:42330719National Natural Science Foundation of China,Grant/Award Number:U2443228+1 种基金Power Construction Corporation of China,Grant/Award Number:DJ-ZDXM-2021-51China Institute of Water Resources and Hydropower Research,Grant/Award Number:GE121003A0042022。
文摘Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environmental impacts.This study reviews the remarkable benefits of check dams on the land reclamation and environmental improvement on the Loess Plateau,and sediment reduction entering the Yellow River.However,the flood incidents on check dams have been frequently reported for the past decades,which has attracted more attention in the context of climate change and extreme rainfall events recently.Advances in the flood migration techniques achieved by the research group led by the first author have been highlighted to migrate the breach risk of check dams due to floods.The“family tree method”has been proposed to determine the survival status and critical rainfall threshold of each check dam in the complicated dam system.An updated dam breach flood evaluation framework and the corresponding numerical algorithm(i.e.,DB-IWHR)have been developed.Moreover,innovative types of water-release facilities for check dams,including geobag stepped spillway and prestressed concrete cylinder pipe in the underlying conduit,have been proposed and developed.Finally,the perspectives concerning the check dam construction on the Loess Plateau have been put forward.
基金Supported by the Construction Fund of Key Medical Disciplines of Hangzhou,No.2025HZGF05the Key R and D Program of Zhejiang Province,No.2023C03054 and No.2024C03048+1 种基金the Key Discipline of Integrated Chinese and Western Medicine(Digestive Diseases)in Zhejiang Province,No.2024-XK-61the Zhejiang Province Medical and Health Science and Technology Plan Project,No.2021KY848.
文摘BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymolysis gauze(refers to sterile gauze soaked in a multi-enzyme cleaning solution)reduces bacterial air pollution in endoscopy rooms.AIM To evaluate the efficacy of an enzymolysis gauze cover in reducing bacterial aerosols from the biopsy valve.METHODS This prospective,single-blind trial included 80 patients undergoing elective diagnostic colonoscopy.During the procedure,the biopsy hole check valve was either covered or left uncovered with enzymolysis gauze.Air samples(100 L)were collected at a distance of 30 cm from the biopsy hole check valve and approximately 140 cm above the floor using a percussive air sampling instrument.Gram-positive bacteria were cultured on standard 90 mm colimycin nalidixic agar blood plates.The primary outcome measures were bacterial load and species identification.RESULTS Covering the biopsy hole check valve with enzymolysis gauze reduced bacterial load near the check valve from 50 colony-forming unit(CFU)/m^(3)[interquartile range(IQR):30-80]to 20 CFU/m^(3)(IQR:10-20).At the end of the procedure each day,covering the valve also decreased bacterial load in the endoscopy room from 35 CFU/m^(3)(IQR:33-85)to 10 CFU/m^(3)(IQR:5-10).The predominant bacteria identified were Gram-positive cocci.CONCLUSION Applying enzymolysis gauze to cover the biopsy hole check valve significantly reduces bacterial aerosol contamination in endoscopy rooms during colonoscopy.
基金jointly funded by the National Key R&D Program of China (2024YFC3012705)the CAS Light of West China Program (Grant Recipient:Wanyu Zhao)+1 种基金the National Natural Science Foundation of China (Grant No.42201095)the Postdoctoral Research Project Special Funding of Sichuan (Grant No.TB2023028)。
文摘The implementation of the cascade check dam system, which integrates beam and closed-type dams, has been extensively adopted as a pivotal engineering measure for mitigating debris flow in Southwest China. In the post-debris flow events, it is imperative to quantitatively assess the volume of sediment volume captured by the cascade check dams and to monitor their impact on sediment dynamics. This study investigates the cascade check dams in Guanmenzi Gully, Beichuan County, Sichuan Province in Southwest China, surveying the reservoir topography of the dams on two occasions over a fiveyear period. The #3 closed-type dam, located in the upper upstream, the #2 closed-type dam, located in the middle stream(which was manually cleaned), and the beam dam, located in the downstream were all surveyed. A simplified yet accurate method was developed to estimate sediment volume within check dam reservoirs under complex topographic conditions. A combination of terrestrial surveys and Unmanned Aerial Vehicle(UAV) based surveys was employed, resulting in the acquisition of two high-resolution Digital Elevation Models(DEMs) at different temporal intervals. The utilization of DEMs of Difference(DoD) facilitated the quantification of terrain variations and the sediment transport. The following conclusions were obtained: firstly, it was found that the volume of sediment trapped in the reservoirs of #2 closed-type dam and #1 beam dam were almost the same, with #3 closed-type dam being the smallest. The validation of the results in conjunction with the geometric method demonstrated that the percentage error was less than 7%, proving the reliability of the results. In addition, an analysis of changes in the detailed topography of the reservoirs revealed that the sediment deposit occurred in areas distant from the structures, while erosion exhibited concentration in specific areas close to the dams. The percentage volume of sediment deposit was found to be significantly higher than that of erosion(all higher than 85%). Furthermore, the excessive sediment deposition reduces the storage capacity of closed-type check dams, whereas in the case of beam dams, the maximum erosion amount in the reservoir is 35.8 m^(3) and the percentage of the maximum erosion amount is 14.00%. This suggests that the self-cleaning of beam dam can effectively slow down the sediment deposition process. Finally, the current study proposes an expression for storage capacity composition and suggests that, in engineering practice, emphasis should be placed on maintenance programs that synergize manual cleaning and self-cleaning of open-type check dams. The conclusions may facilitate the refinement of maintenance strategies of cascade check dams, thereby effectively preventing and mitigating debris flows.
基金The National Natural Science Foundation of China (No.10974093)the Scientific Research Foundation for Senior Personnel of Jiangsu University (No.07JDG014)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province (No.08KJD520015)
文摘In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge is introduced into the past tense operator, and then a new temporal epistemic logic LTLKP is obtained, so that LTLKP can naturally and precisely describe the system＇s reliability. Secondly, a set of prior algorithms are designed to calculate the maximal reachable depth and the length of the longest of loop free paths in the structure based on the graph structure theory. Finally, some theorems are proposed to show how to approximate the complete threshold with the diameter and recurrence diameter. The proposed work resolves the completeness threshold problem so that the completeness of bounded model checking can be guaranteed.
文摘目的探讨美国心脏协会的My Life Check在线评估系统对冠心病患者健康生活方式干预的影响以及其在心脏健康指数评价中的应用效果。方法将心内科随诊的121例冠心病患者用随机数字表分成两组,观察组63例、对照组58例,两组均使用My Life Check其中的Life’s simple 7调查表进行心脏健康调查,观察组根据My Life Check给出的相应健康生活方式指导措施进行干预,对照组常规宣教,并于1个月后对两组患者再次进行心脏健康指数评估。结果观察组及对照组干预后心脏健康指数均明显高于干预前(P<0.05),但干预后观察组较对照组心脏健康指数改善更明显(P<0.05)。结论 My Life Check评估干预能有效改善冠心病患者的健康生活方式。
