目的:观察牙根发育情况,评价iRoot BP Plus与氢氧化钙用于年轻恒牙外伤露髓后部分牙髓切断治疗3年的临床随机对照实验效果。方法:选取符合入组条件的外伤冠折露髓的年轻恒牙104颗,随机分为2组,每组52颗,分别应用iRoot BP Plus(iRoot)和...目的:观察牙根发育情况,评价iRoot BP Plus与氢氧化钙用于年轻恒牙外伤露髓后部分牙髓切断治疗3年的临床随机对照实验效果。方法:选取符合入组条件的外伤冠折露髓的年轻恒牙104颗,随机分为2组,每组52颗,分别应用iRoot BP Plus(iRoot)和氢氧化钙(calcium hydroxide,CH)作为盖髓剂进行部分牙髓切断术治疗。术后1、3、6、12、18、24、30、36个月复查,通过临床及影像学检查观察牙根发育情况,评价临床疗效。结果:CH组和iRoot组最终分别有44颗牙(失访8颗,失访率15.4%)和45颗牙(7颗失访,失访率13.5%)纳入本研究,采用符合方案分析方法的成功率分别为80%和87%,采用意向治疗方案分析方法的成功率分别为67%和75%,两组间差异均无统计学意义(非劣效界值为-10%,疗效差异的95%CI为-8%~22%)。牙髓切断治疗牙的牙根继续发育,根管壁厚度与健康同名对照牙相比差异无统计学意义。iRoot组近冠1/3根管壁厚度比CH组略薄[(1.82±0.21)mm vs.(1.91±0.20)mm,P=0.047]。结论:iRoot BP Plus用于年轻恒牙外伤露髓后牙髓切断治疗可以有效保存活髓,且促进了牙根的继续发育。展开更多
Various defects exist in natural rock masses,withfilled joints being a vital factor complicating both the mechanical characteristics and seepage mechanisms of the rock mass.Filled jointed rocks usually show mechanical...Various defects exist in natural rock masses,withfilled joints being a vital factor complicating both the mechanical characteristics and seepage mechanisms of the rock mass.Filled jointed rocks usually show mechanical properties that are weaker than those of intact rocks but stronger than those of rocks with fractures.The shape of the rock,filling material,prefabricatedfissure geometry,fissure roughness,fissure inclination angle,and other factors mainly influence the mechanical and seepage properties.This paper systematically reviews the research progress andfindings onfilled rock joints,focusing on three key aspects:mechanical properties,seepage properties,andflow properties under mechanical response.First,the study emphasizes the effects of prefabricated defects(shape,size,filling material,inclination angle,and other factors)on the mechanical properties of the rock.The fracture extension behavior of rock masses is revealed by the stress state of rocks withfilled joints under uniaxial compression,using advanced auxiliary test techniques.Second,the seepage properties of rocks withfilled joints are discussed and summarized through theoretical analysis,experi-mental research,and numerical simulations,focusing on organizing the seepage equations of these rocks.The study also considers the form of failure under stress-seepage coupling for both fullyfilled and partiallyfilledfissured rocks.Finally,the limitations in the current research on the rock withfilled joints are pointed out.It is emphasized that the specimens should more closely resemble real conditions,the analysis of mechanical indexes should be multi-parameterized,the construction of the seepage model should be refined,and the engineering coupling application should be multi-field-multiphase.展开更多
In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale ...In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area.Through experiments and numerical simulations,plant roots characteristics,soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed,and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed.The results show that the highest soil moisture infiltration capacity(FIR)is found on the shady slope of the enclosed grassland(2.25),followed by the sunny slope of the enclosed grassland(1.23)and the shady slope of the naturally grazed grassland(-0.87).Correlation analysis show that soil water content,root dry weight density,total soil porosity,number of forks and root length are positively correlated with infiltration rate(P<0.05),whereas soil dry density is negatively correlated with infiltration rate(P<0.05).The results of stepwise regression analyses show that soil water content,total soil porosity,root length and number of forks are the main factors affecting soil infiltration capacity.And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself.After 60 min of simulated rainfall,the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56%and 19.63%,respectively,comparing to those before rainfall.Therefore,in this study,the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content,soil total porosity and shear strength while decreasing soil dry density.The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.展开更多
文摘目的:观察牙根发育情况,评价iRoot BP Plus与氢氧化钙用于年轻恒牙外伤露髓后部分牙髓切断治疗3年的临床随机对照实验效果。方法:选取符合入组条件的外伤冠折露髓的年轻恒牙104颗,随机分为2组,每组52颗,分别应用iRoot BP Plus(iRoot)和氢氧化钙(calcium hydroxide,CH)作为盖髓剂进行部分牙髓切断术治疗。术后1、3、6、12、18、24、30、36个月复查,通过临床及影像学检查观察牙根发育情况,评价临床疗效。结果:CH组和iRoot组最终分别有44颗牙(失访8颗,失访率15.4%)和45颗牙(7颗失访,失访率13.5%)纳入本研究,采用符合方案分析方法的成功率分别为80%和87%,采用意向治疗方案分析方法的成功率分别为67%和75%,两组间差异均无统计学意义(非劣效界值为-10%,疗效差异的95%CI为-8%~22%)。牙髓切断治疗牙的牙根继续发育,根管壁厚度与健康同名对照牙相比差异无统计学意义。iRoot组近冠1/3根管壁厚度比CH组略薄[(1.82±0.21)mm vs.(1.91±0.20)mm,P=0.047]。结论:iRoot BP Plus用于年轻恒牙外伤露髓后牙髓切断治疗可以有效保存活髓,且促进了牙根的继续发育。
基金Postgraduate Research&Practice Innovation Program of Jiangsu Province for Funding support,Grant/Award Number:KYCX22_2843Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:2024XKT0628National Natural Science Foundation of China,Grant/Award Number:52034007。
文摘Various defects exist in natural rock masses,withfilled joints being a vital factor complicating both the mechanical characteristics and seepage mechanisms of the rock mass.Filled jointed rocks usually show mechanical properties that are weaker than those of intact rocks but stronger than those of rocks with fractures.The shape of the rock,filling material,prefabricatedfissure geometry,fissure roughness,fissure inclination angle,and other factors mainly influence the mechanical and seepage properties.This paper systematically reviews the research progress andfindings onfilled rock joints,focusing on three key aspects:mechanical properties,seepage properties,andflow properties under mechanical response.First,the study emphasizes the effects of prefabricated defects(shape,size,filling material,inclination angle,and other factors)on the mechanical properties of the rock.The fracture extension behavior of rock masses is revealed by the stress state of rocks withfilled joints under uniaxial compression,using advanced auxiliary test techniques.Second,the seepage properties of rocks withfilled joints are discussed and summarized through theoretical analysis,experi-mental research,and numerical simulations,focusing on organizing the seepage equations of these rocks.The study also considers the form of failure under stress-seepage coupling for both fullyfilled and partiallyfilledfissured rocks.Finally,the limitations in the current research on the rock withfilled joints are pointed out.It is emphasized that the specimens should more closely resemble real conditions,the analysis of mechanical indexes should be multi-parameterized,the construction of the seepage model should be refined,and the engineering coupling application should be multi-field-multiphase.
基金supported by the National Natural Science Foundation of China(42041006)the Natural Science Foundation of Qinghai Province(2020-ZJ-906).
文摘In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area.Through experiments and numerical simulations,plant roots characteristics,soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed,and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed.The results show that the highest soil moisture infiltration capacity(FIR)is found on the shady slope of the enclosed grassland(2.25),followed by the sunny slope of the enclosed grassland(1.23)and the shady slope of the naturally grazed grassland(-0.87).Correlation analysis show that soil water content,root dry weight density,total soil porosity,number of forks and root length are positively correlated with infiltration rate(P<0.05),whereas soil dry density is negatively correlated with infiltration rate(P<0.05).The results of stepwise regression analyses show that soil water content,total soil porosity,root length and number of forks are the main factors affecting soil infiltration capacity.And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself.After 60 min of simulated rainfall,the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56%and 19.63%,respectively,comparing to those before rainfall.Therefore,in this study,the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content,soil total porosity and shear strength while decreasing soil dry density.The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.
