Artificial neural network for modeling the elastic modulus of electrospun polycaprolactone/gelatin scaffolds

Scaffolds for tissue engineering (TE) require the consideration of multiple aspects, including polymeric composition and the structure and mechanical properties of the scaffolds, in order to mimic the native extracellular matrix of the tissue. Electrospun fibers are frequently utilized in TE due to their tunable physical, chemical, and mechanical properties and porosity. The mechanical properties of electrospun scaffolds made from specific polymers are highly dependent on the processing parameters, which can therefore be tuned for particular applications. Fiber diameter and orientation along with polymeric composition are the major factors that determine the elastic modulus of electrospun nano- and microfibers. Here we have developed a neural network model to investigate the simultaneous effects of composition, fiber diameter and fiber orientation of electrospun polycaprolactone/gelatin mats on the elastic modulus of the scaffolds under ambient and simulated physiological conditions. The model generated might assist bioengineers to fabricate electrospun scaffolds with defined fiber diameters, orientations and constituents, thereby replicating the mechanical properties of the native target tissue.     

Screening for Trauma-Related Sleep Disturbance in Women Admitted for Specialized Inpatient Treatment

Abstract

The authors designed a Sleep Disturbance Screening questionnaire to assist clinicians in disentangling trauma-related factors that contribute to sleep disturbance from other common factors, such as depression. They administered the questionnaire to 129 female psychiatric inpatients, most of whom were treated in a specialty program for trauma-related disorders. Confirmatory and exploratory factor analyses distinguished four sleep disturbance scales, two pertaining to sleep disturbance generally (Insomnia, Hypersomnia) and two pertaining to sleep-related fear (Intrusive, Phobic). Correlations of the sleep disturbance scales with the Childhood Trauma Questionnaire (Bernstein et al., 1994), Impact of Event Scale-Revised (Weiss & Marmar, 1997), Dissociative Experiences Scale (Bernstein & Putnam, 1986), Beck Depression Inventory (Beck & Steer, 1993), and selected scales of the Millon Clinical Multiaxial Inventory (MCMI-III; Millon, 1994) show evidence of convergent and discriminant validity for the Sleep Disturbance Screening. The findings point to the potential diagnostic value of screening for trauma-related sleep disturbance, with the Sleep Disturbance Screening providing a small set of key questions that may be used in psychometric form or incorporated into routine diagnostic clinical interviews.     

表面麻醉纤维喉镜与全麻显微支撑喉镜下对不同类型声带息肉摘除的临床疗效分析

目的比较表面麻醉纤维喉镜与全麻显微支撑喉镜对不同类型声带息肉(VCP)摘除的临床疗效。方法以2007年11月至2012年10月芜湖市第一人民医院收治的164例VCP患者作为研究对象,按照随机数字表法分为两组,表麻纤维喉镜组66例,采用表面麻醉纤维喉镜下VCP摘除术(广基VCP27例、带蒂VCP39例),全麻显微支撑喉镜组98例,采用全麻显微支撑喉镜下VCP摘除术(广基VCP50例、带蒂VCP48例),比较两组治疗效果及术后随访期间并发症发生情况。结果表麻纤维喉镜组手术时间显著短于全麻显微支撑喉镜组[(35.6±12.3)min vs(46.5±17.6)min,P<0.05]。全麻显微支撑喉镜组与表麻纤维喉镜组对带蒂VCP有效率差异无统计学意义(95.8%vs97.4%,P>0.05);但全麻显微支撑喉镜组对广基VCP有效率显著高于表麻纤维喉镜组(94.0%vs81.5%,P<0.05)。全麻显微支撑喉镜组不良并发症发生率与表麻纤维喉镜组比较,差异无统计学意义(7.1%vs 4.5%,P>0.05)。结论表麻纤维喉镜与全麻显微支撑喉镜下VCP摘除术各有优点及局限,临床上应综合考虑以选择最优的治疗方案。     

Scanning Electron Microscopic Study of the Muscle Fiber Ends at the Myotendinous Junction in the Posterior Cricoarytenoid and Cricothyroid Muscles in Rats

The fine structural organization of muscle fiber ends at the myotendinous junction in the posterior cricoarytenoid (PCA) and cricothyroid (CT) muscles in adult rats was studied by scanning electron microscopy, after removal of tendon connective tissues using the HCl-hydrolysis method. The muscle fiber ends in the PCA muscle had a relatively simple conical appearance and contained a great number of longitudinal slits on the surface. In the CT muscle, the muscle fiber ends were classified into two types. One type had a conical appearance similar to the PCA muscle with many slits on the surface, while the other type was characterized by a complex arrangement of cylindrical cytoplasmic processes and deep clefts, as seen in common skeletal muscles. These findings suggest that the PCA muscle is evolutionarily primitive, and that the CT muscles represent a transitional form between primitive and evolved muscles.     

Terror Suicide: How Is It Possible?

How it is possible for people who apparently do not suffer from distress or pathology to commit violent, cruel suicides? Based on the distinction between causes for suicide and facilitators of suicide, I contend that terror suicide is based largely on processes that facilitate suicide rather than on personal distress. Under this premise, terror suicides are examined in terms of enthusiastic determination to achieve a goal, ideological rage, glorification of the post self, heavenly rewards, materialistic benefits for families, induced dissociative processes, and linguistic mediation. Also described are the processes and preparations by which the idea of terror suicide and its facilitators are induced. Further, a theoretically inferred profile of the suicide attacker is also suggested.     

感染科住院医师规范化培训的实践与探索

住院医师规范化培训是医学生毕业后教育的重要组成部分,是培养合格的、具有综合素养的青年医师的重要手段。西安交通大学第二附属医院感染科在住院医师规范化培训的实践与探索中,逐步建立了符合专业特点的规培管理体系,包括规培管理梯队、规培实施细则、三阶段评价反馈体系、教学相长双向培训模式、三维评价体系等,旨在以岗位胜任力为导向,从理论知识、临床技能、医学人文素养、科研能力、人际沟通能力,多维度高质量的进行住院医师规范化培训工作。     

Accuracy and Efficiency of 3-dimensional Dynamic Navigation System for Removal of Fiber Post from Root Canal–Treated Teeth

IntroductionThe purpose of this study was to investigate the accuracy and efficiency of the 3-dimensional dynamic navigation system (DNS) compared with the freehand technique (FH) when removing fiber posts from root canal–treated teeth.MethodsTwenty-six maxillary teeth were included. Teeth were root canal treated and restored with Parapost Taper Lux (Coltene/Whaledent, Altstätten, Switzerland) luted with RelyX Unicem (3M ESPE, St Paul, MN). A core buildup was then performed using Paracore (Coltene/Whaledent). Teeth were mounted in tissue-denuded cadaver maxillae. Teeth were divided into 2 groups: the DNS group (n = 13) and the FH group (n = 13). Cone-beam computed tomographic scans were taken pre- and postoperatively. The drilling path and depth were planned virtually using X-guide software (X-Nav Technologies, Lansdale, PA) in both groups. For the DNS group, drilling was guided with X-Nav software and the FH group under a dental operating microscope. Global coronal and apical deviations, angular deflection, operation time, and the number of mishaps were compared between the groups to determine the accuracy and efficiency. The 3-dimensional volume (mm³) of all teeth was calculated before and after post removal using the Mimics Innovation Suite (Materialise NV, Leuven, Belgium). The Shapiro-Wilk, 1-way analysis of variance, and Fisher exact tests were used (P < .05).ResultsThe DNS group showed significantly less global coronal and apical deviations and angular deflection than the FH group (P < .05). DNS required less operation time than FH. Moreover, the DNS technique had significantly less volumetric loss of tooth structure than the FH technique (P < .05).ConclusionsThe DNS was more accurate and efficient in removing fiber posts from root canal–treated teeth than the FH technique.