13 research outputs found

    PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

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    The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

    2D and 3D models based on patients temporomandibular joint diseases

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    Temporomandibulární kloub (TMK) je jedním z nejsložitějších kloubů v těle. Jeho funkce je řízena koordinací pohybů a postavení zubních oblouků, svalů a kloubů. Změna životního stylu snižuje tělesnou aktivitu, která vede k stále většímu počtu degenerativních onemocnění kloubů s různou etiologií. Proto se zvyšuje i počet pacientů, kteří si stěžují na bolest a další obtíže v oblasti TMK. Odhadem 42% populace má alespoň jeden z příznaků a 2 - 5,5 % vyhledá léčbu. Poruchy čelistního kloubu (TMD) mají klinické příznaky, které zahrnují žvýkací svaly, čelistní klouby i další související anatomické struktury. Typické jsou bolesti, zvukové fenomény, omezené otvírání úst a různé parafunkce dolní čelisti. Základem úspěšné léčby je stanovení příčiny obtíží pacienta. Terapie vychází z modelu ideální biomechaniky TMK. Rehabilitace čelistního kloubu vyžaduje komplexní dlouhodobou léčbu založenou především na fyzikální, chirurgické a protetické terapii. Podrobné znalosti o funkci a morfologii čelistního kloubu jsou nezbytné pro léčbu jeho onemocnění. Pohyby čelistního kloubu jsou biomechanicky sofistikované, ale jejich průběh není zcela objasněn. Cílem PhD práce bylo vytvořit matematický model založený na analýze čelistního kloubu, z hlediska vznikajících sil při tahu a tlaku. Získané výsledky, založené na dvou a...The temporomandibular joint (TMJ) is one of the most complex joints in the body. Its harmony is established by coordination between occlusion, muscle, and joint. Changing lifestyles, decreasing physical activity, which is increasing the number of degenerative joint diseases of various etiologies, and certain dental procedures, are increasing the number of patients complaining of pain or other problems in their temporomandibular joints. Estimated 42% of the population is affected and 2-5,5 % is seeking treatment. Temporomandibular disorders (TMD) are clinical problems that involve the masticatory muscles, the temporomandibular joints and associated anatomical structures. Typical signs and symptoms of TMD are facial pain, clicking or crepitation of the TMJs, limited jaw opening capacity and deviation in the movement patterns of the mandible. The basis of successful treatment is a determination of the patient's causal problems. The analysis is based on the model of the ideal biomechanics of TMJ. The rehabilitation of temporomandibular joint disorders needs comprehensive long-term therapy based mainly on physical, surgical, and prosthetic treatment. Detailed knowledge about the function and morphology of temporomandibular joint are necessary for clinical evaluation and treatment of temporomandibular...Department of StomatologyStomatologická klinika dětí a dospělých2. lékařská fakultaSecond Faculty of Medicin

    National eHealth system – platform for preventive, predictive and personalized diabetes care

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    National eHealth System, covering all citizens and all healthcare levels in Republic of Macedonia, was introduced in July 2013, has been internationally recognized System for successful reduction of waiting times and instrumental in the management of national healthcare resources. For the first time, National Diabetes Committee, formed in February 2015 according to the Law on healthcare and being overall responsible for the diabetes care in the country, was able to derive exact figures on the national diabetes prevalence from the System, instead of extrapolations used before, serving as a basis for development of strategies for prediction and prevention of diabetic complications, as well as for personalized diabetes care. Number of diabetes cases identified through the National eHealth System in June 2015 was 84,568 (4.02 % of total population), 36,119 males (3.42 % of total male population) and 48,449 females (4.61% of total female population). Age stratified diabetes prevalence was as follows: less than 20 years – 549 cases (0.11 % of respective population), 20-39 years – 3,202 (0.49 %), 40-59 years – 26,561 (4.58 %), 60-79 years – 48,470 (14.57 %), 80 years or more – 5,786 (12.96 %). Addition of parameters for metabolic control and diabetic complications in the System is under way, further facilitating the modeling of diabetes treatment, metabolic control and the outcomes. Inclusion of pre-diabetes patients (IGT and IFG) is also planned, thus providing opportunity to also focus healthcare activities for prevention of progression into overt type 2 diabetes

    Numerical modelling of additive manufacturing process for stainless steel tension testing samples

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    Nowadays additive manufacturing (AM) technologies including 3D printing grow rapidly and they are expected to replace conventional subtractive manufacturing technologies to some extents. During a selective laser melting (SLM) process as one of popular AM technologies for metals, large amount of heats is required to melt metal powders, and this leads to distortions and/or shrinkages of additively manufactured parts. It is useful to predict the 3D printed parts to control unwanted distortions and shrinkages before their 3D printing. This study develops a two-phase numerical modelling and simulation process of AM process for 17-4PH stainless steel and it considers the importance of post-processing and the need for calibration to achieve a high-quality printing at the end. By using this proposed AM modelling and simulation process, optimal process parameters, material properties, and topology can be obtained to ensure a part 3D printed successfully

    Mécanismes cérébraux de la régulation de la douleur : perception de la douleur et hypoalgésie induite psychologiquement

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    Objectif : Cette thèse a pour but de préciser les mécanismes neuropsychologiques de la douleur, de la régulation endogène de la douleur et de l'hypoalgésie induite psychologiquement (HIP) par la synthèse de près de trente ans de recherche imagerie cérébrale fonctionnelle. Méthodologie : Étant donné l'abondance des études sur le sujet et le manque d'intégration de leurs résultats, la technique de métaanalyse quantitative basée sur les coordonnées d'activation cérébrale fut privilégiée dans cette thèse, telle qu’implémentée dans l'algorithme ALE (Activation Likelyhood Estimate). Une force supplémentaire de cette thèse repose sur la rigueur du processus de sélection des articles. En effet, les études incluses dans les métaanalyses devaient satisfaire des critères stricts d'inclusion, ceci dans le but de favoriser la précision et la validité des conclusions subséquentes. Étude 1 : Le premier article visait à identifier les aires cérébrales impliquées dans la réduction de la douleur par des méthodes psychologiques d'interventions. Les articles retenus portent sur une variété de méthodes d'intervention, telles que le placebo, l'hypnose, la méditation, la perception de contrôle sur la stimulation douloureuse et l'induction d'émotions. Les résultats indiquent que l'HIP implique un vaste réseau d'activation qui comprend le cortex cingulaire antérieur, l'insula antérieure, les zones orbitofrontale et préfrontale latérale, ainsi que les régions pariétale, temporale et souscorticales. Ces activations reflèteraient l'implication des mécanismes neuropsychologiques cognitifs et émotionnels sous-tendent les interventions psychologiques ciblées par ces études, incluant la conscience de soi et la motivation. De plus, les divergences de patron d'activation entre les approches ont été explorées, notamment pour le placebo et la distraction. Étude 2 : Le deuxième article a identifié des patrons d'activations préférentiellement associés à la perception de la douleur, à l'HIP, ainsi que des activations communément associées à la douleur et l'HIP. Les résultats indiquent que 1) la perception de la douleur est associée à l'activation d'aires somatosensorielles et motrices, ce qui pourrait être le reflet de la préparation d'une action adaptative, 2) l'HIP est liée à l'engagement de régions préfrontales antéromédianes et orbitales, possiblement en lien avec des processus motivationnels et émotionnels, et 3) la douleur et l'HIP sont associés à l'activation d'aires préfrontales dorsolatérales, de l'insula antérieure et du cortex cingulaire moyen, ce qui pourrait refléter l'engagement spontané pendant la douleur de mécanismes endogènes de régulation descendante. Conclusion : Par ces études, cette thèse fait le point sur les mécanismes cérébraux impliqués différentiellement dans la perception de la douleur, dans sa régulation endogène et dans l'hypoalgésie induite psychologiquement.Objective: This thesis aims to clarify the neuropsychological mechanisms of pain, of the endogenous regulation of pain and of psychologically induced hypoalgesia (PIH), through the synthesis of almost thirty years of functional brain imaging research. Methodology: Given the abundance of studies in this domain and the lack of integration of their results, we used the quantitative meta-analysis technique based on brain activation using the ALE (Activation likelihood Estimate) statistic. The strength of this thesis lies in the globalized perspective of the litterature, and in the rigor of the article selection process from which results were extracted. Indeed, the studies included in the meta-analyses needed to meet strict inclusion criteria in order to strengthen the accuracy and the validity of subsequent conclusions. Study 1: The first article is aimed at identifying brain areas involved in pain reduction through psychological methods of intervention. Chosen articles that covered a variety of approaches, such as placebo, hypnosis, meditation, perception of control over the stimulation, and induction of emotions. Analysis across these various studies indicated that PIH involves a broad network of activation that includes the anterior cingulate cortex, anterior insulae, orbital and lateral prefrontal and frontal areas, as well as parietal, temporal and subcortical regions. This activation network may reflect the involvement of diverse neuropsychological mechanisms in the various affective, self-awareness, cognitive and motivational processes underlying the psychological interventions targeted by these studies. In addition, we explored some specific patterns of brain activity related to placebo and distraction, in comparison to other approaches. We propose several hypotheses regarding the distinctive neuropsychological processes underlying these approaches. Study 2: The second article aimed at investigating patterns of brain activity preferentially associated with pain perception or with PIH. First we assessed patterns of increased and decreased activity during experimental pain in healthy volunteers. Second we determined the brain regions preferentially activated during pain perception or during PIH with subtraction analyses. Using a conjunction analysis, we also determined a set of brain regions possibly involved in regulatory processes activated spontaneously during acute of pain. Our results indicate that 1) somatosensory and motor areas are preferentially related to pain perception, which may reflect the preparation of a motor response, 2) dorsolateral prefrontal areas, anterior insula and the anterior midcingulate cortex were associated with both pain and PIH and may reflect the spontaneous activation of top-down regulation mechanisms during pain, and 3) antero-medial and orbital prefrontal regions were preferentially associated with PIH, which may indicate motivational and emotional processes associated with the engagement of an externally driven hypoalgesic procedure

    The University of Iowa 2018-19 General Catalog

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    The University of Iowa 2020-21 General Catalog

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