初期弾性率を組み入れた非圧縮超弾性モデルによる動脈組織の非線形の力学的挙動の特性評価：定式化と動脈硬化，動脈解離への適用

九州工業大学博士学位論文（要旨）学位記番号：生工博甲第382号 学位授与年月日：令和2年9月25

Medial epicondyle fractures in children: a study of functional outcome of surgical fixation

Background: Medial epicondyle fracture is a common elbow injury in children. It is associated with elbow dislocation in many cases. Treatment of displaced medial epicondyle fracture with and without elbow dislocation is a debated topic. Surgical and non surgical methods are practiced with variable results.Methods: Our study was a prospective study of medial epicondyle fractures treated by surgical fixation with k wires. We studied total of 24 cases out of which 15 had elbow dislocation. The study period was from 2012 to 2015 and indications for surgery were displacement more than 5 mm, elbow instability, incarceration of fragment, ulnar nerve irritation. Open reduction and internal fixation with K wire done. We used joystick method while reducing the fragment with k wire which was a great help. We assessed the cases using mayo elbow performance score.Results: Our study yielded excellent results in 92% of patients (mayo elbow performance score >90). There was no major difference in clinical outcome between two groups of patients. Complications like instability and non-union not seen following surgical fixation with K wires. The mean loss of flexion, extension, supination, and pronation was 4, 5, 3 and 2 degrees respectively with elbow dislocation group and 2, 3, 1, 1 in without dislocation group. Pre op instability seen in 54% patients was absent in follow up period. Stiffness was more in elbow dislocation group but overall performance was almost equal.Conclusions: Surgical fixation of medial epicondyle fractures yields excellent results and may be advisable when indicated

Role of General Dental Practitioners in Smoking Cessation Programme

Tobacco use is a dental as well as a medical problem. Its use is the root cause of many oral health problems including periodontal disease and tooth loss. In the past few years, there has been an increasing awareness of the role of tobacco use in the prevalence and severity of periodontal disease. Like other health professions, dentistry has taken a stand against cigarette smoking. Dentists can use a variety of smoking cessation techniques to prevent the oral health problems associated with tobacco use. To carry out a minimal programme of antismoking measures, dentists in general practice can serve as a non-smoking role model for their patients, provide information about the health hazards of smoking, give advice and guidance, refer patients to cessation programmes, recommend cessation measures and monitor patients’ effort to quit smoking. Dental practice in 21st century has to increasingly move from a restorative orientation to one of a broader promotion of health and wellbeing

Paediatric forearm refractures- management and outcome: a prospective study

Background: Forearm fractures are one of the commonest injuries accounting for 40% of paediatric fractures with a refracture rate of nearly 5%. Forearm refractures are increasing probably due to poor bone mineralization as a result of decreased physical activity, Vitamin D deficiency. These are treated by conservative measures with closed reduction and casting or by surgical fixation with flexible nails or plates. There are no definitive guidelines for management of forearm refracture and implant removal.Methods: The study is aimed at the epidemiology, methods and difficulties of management and functional outcome of forearm refracture treatment. A prospective study of all the cases of forearm refracture who presented to our institution from 2010 to 2016 with refractures treated either by conservative methods or by IMN. All cases were followed up for 2 years and functional outcome was assessed serially according to price et-al criteria.Results: Our study contained 17 males and 8 females between 6 years and 14 years. 76% refractures occurred before 16 weeks and majority had only tricortical union at this time. 42% patients underwent surgical fixation following refracture. Price et al criteria showed excellent results in 72% of patients.Conclusions: Forearm refractures in children can be treated both conservatively and surgically like a primary fracture depending on the indications but needs 2 to 3 more weeks of immobilization. A good functional outcome was obtained in majority of the cases. We suggest using splints till quadricortical union is achieved to prevent chances of refracture

Mechanical characterization of dissected and dilated human ascending aorta using Fung-type hyperelastic models with pre-identified initial tangent moduli for low-stress distensibility

Ascending aortic dissection (AD) is a potentially fatal vascular disease associated with degradation and fragmentation of the elastic fibers in the aortic media, increasing low-stress distensibility, and a dilated aorta may lead to dissection. In this study, a Fung-type hyperelastic model was formulated incorporating the initial tangent moduli (ITM) of stress–strain curves as an index of low-stress distensibility. ITM were correlated with the material constants by linearizing incompressible stress–strain relationships at zero strain. For uniaxial loading tests, the robustness of the material constants was examined in the stress ranges of 0–200, 0–180, and 0–160 kPa and to the ITM values of 100%, 95%, and 90%. Examination revealed stable changes in the material constants of 80% of the specimens. For equibiaxial stretch tests, the material constants were determined for each curve of the isotropic and anisotropic deformation groups by pre-identifying the ITM and minimizing fitting errors using isotropic or anisotropic models. The errors for all groups were <6% using a transversely isotropic model, and <10% for an orthotropic model. Comparisons with experimental curves showed that Fung-type models described both the ITM and significant stiffening at high stress levels. The mechanical characteristics of the aorta in the stage prior/posterior to dissection is such that while hardening occurs under both low- and high-stress levels with an increase in collagen content as an aging response, softening occurs under low-stress conditions due to histological abnormalities such as elastin deficiency and fragmentation. Numerical simulations using Fung-type models implied that elastic fiber degeneration and fragmentation in AD tissues reduced not only the low-stress stiffness but also the elastic stiffness with superimposed shear. The latter stiffness was modulated by the stiffening at high stress levels in tensile deformation behavior and normal-strain state under physiological loading conditions, and therefore provides further insight into wall rupture.journal articl

Simulation in Medical School Education: Review for Emergency Medicine

<p>Medical education is rapidly evolving. With the paradigm shift to small-group didactic sessions and focus on clinically oriented case-based scenarios, simulation training has provided educators a novel way to deliver medical education in the 21st century. The field continues to expand in scope and practice and is being incorporated into medical school clerkship education, and specifically in emergency medicine (EM). The use of medical simulation in graduate medical education is well documented. Our aim in this article is to perform a retrospective review of the current literature, studying simulation use in EM medical student clerkships. Studies have demonstrated the effectiveness of simulation in teaching basic science, clinical knowledge, procedural skills, teamwork, and communication skills. As simulation becomes increasingly prevalent in medical school curricula, more studies are needed to assess whether simulation training improves patient-related outcomes.</p

Identification Of Uniaxial Deformation Behavior and Its Initial Tangent Modulus for Atheromatous Intima in The Human Carotid Artery and Thoracic Aorta Using Three-Parameter Isotropic Hyperelastic Models

Uniaxial stretching tests are used for mechanical identification of small fibrous regions of atheromatous arteries. Material constants in isotropic hyperelastic models are determined to minimize the fitting error for the stress–strain curve. We developed a novel method to better characterize the material constants in typical forms of Yeoh, Ogden, Chuong–Fung (CF) and Gasser–Ogden–Holzapfel (GOH) isotropic hyperelastic models for fibrous caps and normal intimal layers from human carotid artery and thoracic aorta by incorporating Young’s modulus, i.e., the initial tangent modulus of uniaxial stress–strain relationships, as one of three material constants. We derived a unified, isotropic form for the anisotropic exponential-type strain energy density functions of CF and GOH models. The uniaxial stress–strain relationship equations were expanded to Maclaurin series to identify Young’s modulus as a coefficient of the linear term of the strain and to examine the roles of the material constants in the nonlinear function. The remaining two material constants were determined by curvefitting. The incorporation of Young’s modulus into the CF and GOH models gave reasonable curvefitting, with errors 10%) were observed in one case for the Yeoh model and in two cases for the Ogden model.journal articl

Antioxidant Property of a Novel Lemongrass Oil Mouth Wash: An Experimental Study

Oxidative stress is believed to be in part responsible for the inflammatory conditions affecting the periodontium manifesting as gingivitis and periodontitis. Antioxidants are those substances which when present in minimum quantities prevents the oxidation of a substrate. Recently, there has been a considerable interest in finding natural antioxidants from plants. Natural antioxidants are presumed to be safe since they occur in plant foods. These natural antioxidants occur in all higher plants, and in all parts of plants.The aim of our study was to compare the efficacy of lemongrass oil mouthwash for anti oxidant property by estimation of thiol levels before and after administration of lemongrass oil mouthwash. A total of 40 subjects were included in this study. Subjects were divided into 4 groups i.e. 3 test groups and one control group. Initially, saliva and gingival crevicular fluid (GCF) were collected and sent for analyzing the thiol levels. After scaling, lemongrass oil mouthwash that was prepared indigenously was administered at three different concentrations. Subjects were recalled on the 15th day; saliva and GCF sample were collected and sent for estimation of thiol levels. Statistical analysis was done using SPSS 16.0 software and results were analyzed.There was no statistical difference in the thiol levels within the case groups whereas the subjects in the case group showed increased thiol levels when compared to the control group. The lemongrass oil mouthwash was found to have anti oxidant activity at all the three concentrations levels

Influence of Titanium on the Microstructure and Wear Properties of Spray-Formed Hypereutectic Al-Si Alloys

The present study explored the development of hypereutectic Al-Si alloys such as Al-15Si (SF1), Al-15Si-0.5Ti (SF2), Al-15Si-1.0Ti (SF3), and Al-15Si-2Ti (SF4) alloys by spray forming, a technique that yields refined microstructures with minimal segregation, and examined the effects of titanium (Ti) on the microstructure and wear properties of alloys at various temperatures. Microstructural analysis revealed equiaxed aluminum (Al) matrices with distributed silicon (Si) phases and Al3Ti intermetallics in Ti-containing alloys. The addition of Ti refined the microstructure and enhanced the refinement of Si particles. The hardness increased as Ti content increased in the alloy, with spray-formed alloys (SF) exhibiting 30-35% higher hardness than their as-cast (AC) counterparts at all temperatures. The SF alloys demonstrated improved wear resistance, with 50-65% lower wear rates than AC alloys at 25 °C and 68-82% lower at 250 °C. Specifically, the Al-15Si-2Ti SF alloy exhibited 62% and 82% lower wear rates than Al-15Si-2TiAC alloy at 25 °C and 250 °C, respectively. The coefficient of friction (COF) decreased with load for both AC and SF alloys, while COF values increased as the temperature increased. The AC alloys exhibited a 21-35% increase in coefficient of friction (µ) per unit rise in temperature, while SF alloys showed a significantly lower increase of 0.18-0.29%. The SF4 alloy demonstrated the lowest COF across the entire load and temperature range. Spray-formed hypereutectic Al-Si-Ti alloys demonstrate a high potential for aerospace and automotive applications due to their refined microstructure and enhanced wear resistance, achieved through addition of Ti, making them suitable for high-performing applications