Canal Transportation and Centering Ability in Long Oval Canals: A Multidimentional Analysis

IntroductionThe purpose of this study was to evaluate and compare the centering ability and canal transportation of the ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) and Self-adjusting File (SAF; ReDent-Nova, Ra'anana, Israel) systems in long oval root canals using cone-beam computed tomography imaging.MethodsFifty-six fully formed single-rooted mandibular premolars were selected with a buccolingual canal size 2 to 2.5 times the mesiodistal size at 5 mm from the apex, ranging from a 0°–10° canal curvature with a 5- to 6-mm radius. The teeth were divided into 2 groups (n = 28) and prepared with PTN or SAF according to the manufacturers’ instructions. Cone-beam computed tomographic images were taken in the same position before and after instrumentation using modeling wax. The centering ability and canal transportation were calculated at 3, 6, and 9 mm from the apex in both mesiodistal and buccolingual directions. The mean and standard deviation were calculated, and the Student t test was used for comparative analysis.Resultssignificant difference for canal transportation was observed mesiodistally at 9 mm from the apex (P < .05) where the PTN shaved more dentin in 1 direction. A significant difference for the centering ability was observed at 6 mm buccolingually from the apex (P < .05) where the PTN was less centered in the canal compared with the SAF.ConclusionsBoth SAF and PTN were shown to be safe for being used in long oval canals. SAF resulted in less transportation at the coronal third in the mesiodistal direction and more centered at the middle third in the buccolingual direction compared with PTN.     

Root Canal Shaping Using Nickel Titanium,M-Wire,and Gold Wire: A Micro–computed Tomographic Comparative Study of One Shape,ProTaper Next,and WaveOne Gold Instruments in Maxillary First Molars

Introduction

The aim of this study was to evaluate the root canal shaping effect of instruments manufactured from nickel titanium, M-Wire, and Gold wire with different glide path preparation techniques.

Changes in Geometry and Transportation of Root Canals with Severe Curvature Prepared by Different Heat-treated Nickel-titanium Instruments: A Micro–computed Tomographic Study

IntroductionThe aim of this study was to compare the shaping ability of 4 different nickel-titanium systems, considering their variation in alloy treatment, kinematics, and design, used to prepare canals with severe curvature using micro–computed tomographic analysis.MethodsThirty-two mesial roots of mandibular molars with severe curvature were matched based on similar morphologic dimensions and assigned to 4 experimental groups (n = 8) according to the canal preparation: ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (RC; VDW GmbH, Munich, Germany), Reciproc Blue (RCB, VDW GmbH), and TRUShape (TRU; Dentsply Tulsa Dental Specialties, Tulsa, OK) systems. Changes in 2-dimensional (area and perimeter) and 3-dimensional (volume, surface area, and structure model index) morphologic parameters as well as canal transportation were compared among groups using the analysis of variance post hoc Tukey tests with the significance level set at 5%.ResultsPreparation significantly increased all analyzed parameters. No statistically significant differences (P > .05) were observed between RC and RCB or between PTN and TRS in any of the analyzed parameters. In the cervical third, RC and RCB presented higher mean increases than PTN and TRU. In the apical third, there were no statistically significant differences (P > .05) among the systems.ConclusionsThe instruments of greater taper may promote greater morphologic changes. However, regardless of the number of instruments (multiple or single), the type of movement (rotation or reciprocating), the type of heat treatment of alloys, and the particular characteristics of each instrument (taper and design), the evaluated systems did not result in different dimensional changes and canal transportation in the critical apical area.     

Widening Time Disparities between Two Paradigms: Tama-REgistry of Acute Endovascular Thrombectomy

Background

The Tama-REgistry of Acute endovascular Thrombectomy (TREAT) is a multicenter registry of endovascular thrombectomy in the Tama area of Tokyo. The objective of this study was to confirm the real-world status of 2 paradigms of transportation.

Ramps remain a barrier to safe wheelchair user transit bus ingress/egress

Abstract

Background: Wheelchair users (WCUs) often rely on ramps for access to transit buses. Previous studies indicate WCUs have difficulty using ramps for bus ingress/egress and many transportation-related incidents occur on ramps. However, experiences of WCU ramp usage during ingress/egress have not been fully described.

Methods: Cross-sectional, internet-based survey of WCUs who ride transit buses was conducted. The participants were queried on frequency of bus usage, difficulty and incidents involving ramps, and factors contributing to difficulty and incidents. Wheelchair characteristics, primary condition, and whether participants received travel training were also captured. Chi-square was used to describe relationships between wheelchair type and frequency of difficulties and incidents, and odd ratios were used to determine likelihood of the incidents.

Results: The majority (55.7%) of 384 participants reported using public transportation ≥ 1 per week. Seventy-eight percent of WCUs had ≥ 1 ramp incident over the past 3?years, with an increased likelihood of incidents occurring during ingress (OR = 1.53; CI 1.21–1.86). Of those who had an incident, 22% were injured or had damage to their wheelchair. Over 60% of those who had an incident identified steep ramp slope as being the contributing factor. Steep ramp slope, exterior ramp thresholds and wet surfaces were the most common contributing factors to difficulty using ramps.

Conclusion: This is the first large-scale US study enabling WCUs to describe their experiences using transit bus ramps. Despite ADA guidelines, steep ramps remain the primary factor contributing to incidents and difficulty when using ramps to access transit buses.

• Implications for rehabilitation

• The discrepancy between ADA maximum allowable ramp slopes for the built environment and transit buses may require an increased level of effort that is a barrier to transportation accessibility for some wheelchair users.

• Wheelchair users who access transit buses should be made aware of, and trained, to navigate ramp configurations found in the environment.

• We suggest rehabilitation therapists provide skills training specific to navigating transit bus ramp slopes that may be steeper and narrower than building ramps.

     

基于“脾主运化”理论探讨肝细胞自噬与脂质代谢的关系＊

脾位于中焦,主运化,为气血生化之源。膏脂由脾运化水谷所生,中土得运,纳运有常,则膏脂可随血循环以濡养五脏六腑及四肢百骸;肝脏是脂质代谢重要的器官,其参与脂质消化、吸收、转运等功能,脾气健运,肝失疏泄,肝脏脂质代谢功能与"脾"运化功能相关。肝细胞自噬是维持肝脏脂质代谢稳态的关键因素之一,自噬功能正常则肝脏脂质代谢趋于平衡。本文基于脾与脂质相关性,从"脾主运化"探讨肝细胞自噬对脂质代谢的影响及机制。     

Evaluation of the Amount of Root Canal Dentin Removed and Apical Transportation Occurrence after Instrumentation with ProTaper Next,OneShape, and EdgeFile Rotary Systems

IntroductionThe aim of this study was to evaluate the amount of root canal dentin removed and apical transportation occurrence after instrumentation of mesiobuccal canals of maxillary molars with ProTaper Next (PTN [Dentsply Maillefer, Ballaigues, Switzerland]), OneShape (OS [MicroMega, Besançon, France]), and EdgeFile (EF [Edge Endo, Albuquerque, NM]) rotary systems.MethodsTwenty-seven mesiobuccal canals of maxillary molars were used. Canals were randomly divided into 3 groups for canal preparation: PTN, EF X3, or OS (n = 9 for each group). Micro–computed tomographic imaging was used to measure apical transportation (mm) and the volume of dentin removed (mm³). The amount of dentin removed was measured for the coronal portion and for the whole canal length. Superposition of pre- and postoperative cross-sectional apical slices were used to measure apical transportation at 1 mm from the apex; the differences were evaluated using the Kruskal-Wallis test and Wilcoxon analysis. The Spearman correlation coefficient was used to display the relationship between variables for each group. The significance level was set at P < .05.ResultsThe percentages of the amount of dentin removed on the coronal portion and the amount removed for the whole canal length were statistically similar between groups (P > .05). The average amount of apical transportation for the PTN, OS, and EF X3 were 0.197, 0.263, and 0.218 mm, respectively. Statistically, there were no significant differences between the 3 rotary instruments for apical transportation.ConclusionsThe amount of dentin removed for the coronal third portion and the whole canal length was similar for the PTN, OS, and EF X3 rotary instruments. Although there were differences in the sizes of apical enlargement, no apical transportation was observed in any of the instrumentation systems.     

外泌体的生物学特征及其作为靶向药物载体在恶性肿 瘤的应用

肿瘤治疗过程中会出现很多严重的不良反应，如何将药物特异性导向癌细胞就成为了肿瘤治疗中亟需解决的问 题。外泌体是由细胞分泌的、纳米级别的、双层脂质的盘状囊泡结构。正常细胞与肿瘤细胞均可分泌外泌体，供体细胞分泌的 外泌体携带着蛋白质、脂质和核糖核酸（包括microRNA和lncRNA），可直接被同组织内其周围的受体细胞所吸收；同时外泌体 几乎存在于唾液、血液、尿液、脑脊髓液等所有体液中，通过体液运输被不同组织内受体细胞所吸收，为受体细胞的生长提供必 要的营养物质。肿瘤细胞中往往可对外释放出高于正常组织的外泌体，在肿瘤发展过程中外泌体对肿瘤的生长、转移和血管 生成起到重要的作用；同时癌细胞所分泌的外泌体中有着可用来区别与其他细胞外泌体不同的特征性分子，可作为肿瘤临床 诊断的分子标志物，也可作为肿瘤分级、精准治疗及预后评估的重要依据。鉴于此，本文收集国外内相关研究资料，对外泌体 的生物学特征进行总结，并综述了其在临床肿瘤诊断、治疗中的作用及应用潜力，并对外泌体进一步的发展方向进行展望，以 期能为外泌体在临床肿瘤精准治疗中的应用提供理论支持。