How structural and functional MRI can inform dual-site tACS parameters: A case study in a clinical population and its pragmatic implications

BackgroundAbnormalities in frontoparietal network (FPN) were observed in many neuropsychiatric diseases including substance use disorders. A growing number of studies are using dual-site-tACS with frontoparietal synchronization to engage this network. However, a computational pathway to inform and optimize parameter space for frontoparietal synchronization is still lacking. In this case study, in a group of participants with methamphetamine use disorders, we proposed a computational pathway to extract optimal electrode montage while accounting for stimulation intensity using structural and functional MRI.MethodsSixty methamphetamine users completed an fMRI drug cue-reactivity task. Four main steps were taken to define electrode montage and adjust stimulation intensity using 4x1 high-definition (HD) electrodes for a dual-site-tACS; (1) Frontal seed was defined based on the maximum electric fields (EF) predicted by simulation of HD montage over DLPFC (F3/F4 in EEG 10–10), (2) frontal seed-to-whole brain context-dependent correlation was calculated to determine connected regions to frontal seeds, (3) center of connected cluster in parietal cortex was selected as a location for placing the second set of HD electrodes to shape the informed montage, (4) individualized head models were used to determine optimal stimulation intensity considering underlying brain structure. The informed montage was compared to montages with large electrodes and classic frontoparietal HD montages (F3-P3/F4-P4) in terms of tACS-induced EF and ROI-to-ROI task-based/resting-state connectivity.ResultsCompared to the large electrodes, HD frontoparietal montages allow for a finer control of the spatial peak fields in the main nodes of the FPN at the cost of lower maximum EF (large-pad/HD: max EF[V/m] = 0.37/0.11, number of cortical sub-regions that EF exceeds 50% of the max = 77/13). For defining stimulation targets based on EF patterns, using group-level head models compared to a single standard head model results in comparable but significantly different seed locations (6.43 mm Euclidean distance between the locations of the frontal maximum EF in standard-space). As expected, significant task-based/resting-state connections were only found between frontal-parietal locations in the informed montage. Cue-induced craving score was correlated with frontoparietal connectivity only in the informed montage (r = ?0.24). Stimulation intensity in the informed montage, and not in the classic HD montage, needs 40% reduction in the parietal site to reduce the disparity in EF between stimulation sites.ConclusionThis study provides some empirical insights to montage and dose selection in dual-site-tACS using individual brain structures and functions and proposes a computational pathway to use head models and functional MRI to define (1) optimum electrode montage for targeting FPN in a context of interest (drug-cue-reactivity) and (2) proper transcranial stimulation intensity.     

Precision and Accuracy of Measurements on CT Scout View

ObjectivesThe purposes of this study were to (1) investigate the limits of measurements on scout view in three computed tomography axes, x, y and z and (2) develop a model to provide better understanding of measurement accuracy.MethodsFor the first objective, anteroposterior and lateral scout views of a Catphan phantom 200 mm in diameter and length were acquired with a GE scanner at 21 different table heights. Phantom measurements on scout view were performed by two experienced readers. The comparison of their measures provided estimation of precision. The accuracy was assessed by determining the bias, calculated as the difference between the values measured on scout view and the real phantom size. Second, a model was developed investigating the relationship between the dimensions of the object, its image, and the table height. This relationship was tested on our data.ResultsScout view measurements were precise, with less than 0.53% difference between readers. In addition, small biases of about 1 mm were detected in the z-axis, whatever the table height. In the other axes, serious biases from −13 to +73 mm were measured. Furthermore, at isocentre, overestimations up to 7 mm were shown. The results also indicated that biases in scout view measurements are because of the geometrical projection related to the object-detector distance.ConclusionsMeasurements in the table movement axis are precise and accurate, conferring to scout views an added value for preoperative planning in orthopedic surgery.     

PBL教学法在中医急诊学教学中的运用分析

目的分析PBL教学法在中医急诊学教学中的运用效果。方法2018年3月-2018年6月选取本校2016级针推专升本学生68名进行调查,采用随机数字表法将其分为2组,各34名,观察组采取PBL教学法,对照组采取传统讲授法,对比2组学生的理论、实践考核成绩,并通过调查问卷评价学生对教学方法的认可程度。结果实施教学后,观察组学生理论、实践考核成绩较对照组学生明显提高(P<0.05)。相比于对照组,观察组学生在培养学习兴趣、提升学习技巧、增强合作能力、创新思维方式的层面上对教学方法的认可程度普遍较高(P<0.05)。结论采取PBL法实施中医急诊学教学有助于提升临床教学效果和质量。     

康复护理教学中应用Seminar教学法的分析

目的 探讨康复护理教学中应用Seminar教学法的效果.方法 选择医院2018年6月—2019年6月在肿瘤科实习的80名护理学生作为本次研究入组对象,根据随机数字表随机分为研究组和对照组,每组40名学生.对照组采用传统护理教学方法 ,研究组采用Seminar教学法,分析对比两组护理学生的教学效果.结果 研究组护理学生理论考试、技能考试、综合成绩高于对照组护理学生成绩(P<0.05).研究组护理学生自主学习情况由于对照组护理学生(P<0.05).结论 康复护理教学中应用Seminar教学法的效果好,有利于激发学生学习兴趣,巩固学生护理基本知识技能,提高护理思维能力,从而提高护理教学质量.     

情景模拟联合案例讨论在急诊护理临床带教中的应用体会

目的探究急诊护理临床带教中采用情景模拟、案例讨论联合教学法效果。方法在本院实习的若干名护生中,选取124名护生分按照教学方法分组,对照组62名实施传统急诊护理带教,观察组62名实施案例讨论、情景模拟联合教学法,对比临床带教效果。结果两组实践与理论成绩相比,观察组成绩更高(P<0.05)。思维、急救及应激能力自我评价相比,观察组的总提高率高于对照组(P<0.05)。实施案例分析结合情景模拟教学模式后,问卷调查中观察组无护生不赞同此模式,非常赞同此教学模式的护生占总人数的90%以上。结论实施案例讨论、情景模拟联合教学模式后,护生急诊护理实践与理论水平均提升,护生我评价较高。     

颞下颌关节强直动物模型中最大张口度与强直严重程度关系研究

目的　研究主、被动最大张口度（AMMO、PMMO）与颞下颌关节强直严重程度的关系。方法　选取28只健康雄性绵羊随机分为实验组和对照组，每组各14只。实验组绵羊双侧颞下颌关节模拟髁突矢状骨折，其中左侧翼外肌被切断以阻断其功能；对照组绵羊未进行手术。于术前及术后12、24周对所有绵羊体重、AMMO、PMMO、颞下颌关节形态学特点进行测量评估。结果　实验组只有右侧保留翼外肌功能的颞下颌关节发生了骨强直。术后12、24周，实验组绵羊AMMO、PMMO、极限距离均显著低于对照组，差异均有统计学意义（均P < 0.05）。实验组绵羊AMMO和PMMO与骨融合区宽度、长度、面积及钙化程度均呈负相关（均P < 0.05），其中骨融合区面积为主要影响因素（术后12、24周相关系数r分别为-0.94、-0.95）。结论　颞下颌关节强直动物模型中阻断翼外肌功能可阻止骨强直的发生；对于早期髁突矢状骨折，可通过牙合垫或牙合板进行张口训练，进而阻断翼外肌功能。当颞下颌关节发生骨强直时，骨融合区面积越大，张口受限越明显。