Untersuchungen zur Pathogenese der "Bypass graft disease"

Untersuchung zur Pathogenese der 'Bypass graft disease' Histomorphologische Untersuchungen und in vitro Zellkulturanalysen bilden die Grundlage für Fortschritte im Verständnis der pathologischen Mechanismen der aortokoronaren 'Bypass graft disease'. In der vorliegenden Arbeit wurde die pathomorphologische Veränderung der Gefäßanatomie im Verlauf der 'Bypass graft disease' an Hand histologischer Präparate explantierter humaner venöser Bypass-Läsionen analysiert. Erstmalig wurde ein histomorphologisches Klassifizierungsschema (Typ I - Typ III) beschrieben. Morphometrische Analysen zeigten, dass die Fläche der Neointima und Media im Verlauf der pathologischen Umgestaltung der Bypass-Architektur (Typ I zu Typ III) deutlich zunimmt. Bestimmungen der Zelldichte dokumentierten eine deutlich größere Zellzahl in allen Gefäßwandschichten der Bypass-Läsionen bei der Gegenüberstellung mit einer Kontrollgruppe nativer Venen, wobei im Verlauf der 'Bypass graft disease' (Typ I zu Typ III) eine Abnahme der Zelldichte zu beobachten war. Erstmalig durchgeführte Untersuchungen zur Proliferationsaktivität in aortokoronaren Bypass-Läsionen im Vergleich zu nativen Gefäßen präsentierten eine deutlich höhere zelluläre Proliferation in den Bypass-Präparaten. Diese war am stärksten in Typ III Läsionen ausgeprägt. Expressionsstudien im in vitro Zellkulturmodellsystem identifiziereten die homodimeren Isotypen (AA / BB) des Wachstumsfaktors PDGF als Stimulatoren der Transkriptionsfaktoren c-fos und c-myc in primärkultivierten humanen Muskelzellen der Aorta.

Synthesis of Hand Exoskeletons for the Rehabilitation of Post-Stroke Patients

This dissertation presents the synthesis of a hand exoskeleton (HE) for the rehabilitation of post-stroke patients. Through the analysis of state-of-the-art, a topological classification was proposed. Based on the proposed classification principles, the rehabilitation HEs were systematically analyzed and classified. This classification is helpful to both understand the reason of proposing certain solutions for specific applications and provide some useful guidelines for the design of a new HE, that was actually the primary motivation of this study. Further to this classification, a novel rehabilitation HE was designed to support patients in cylindrical shape grasping tasks with the aim of recovering the basic functions of manipulation. The proposed device comprises five planar mechanisms, one per finger, globally actuated by two electric motors. Indeed, the thumb flexion/extension movement is controlled by one actuator whereas a second actuator is devoted to the control of the flexion/extension of the other four fingers. By focusing on the single finger mechanism, intended as the basic model of the targeted HE, the feasibility study of three different 1 DOF mechanisms are analyzed: a 6-link mechanism, that is connected to the human finger only at its tip, an 8-link and a 12-link mechanisms where phalanges and articulations are part of the kinematic chain. The advantages and drawbacks of each mechanism are deeply analyzed with respect to targeted requirements: the 12-link mechanism was selected as the most suitable solution. The dimensional synthesis based on the Burmester theory as well as kinematic and static analyses were separately done for all fingers in order to satisfy the desired specifications. The HE was finally designed and a prototype was built. The experimental results of the first tests are promising and demonstrate the potential for clinical applications of the proposed device in robot-assisted training of the human hand for grasping functions.

The twofold role of Cloud Computing in Digital Forensics: target of investigations and helping hand to evidence analysis

This PhD thesis discusses the impact of Cloud Computing infrastructures on Digital Forensics in the twofold role of target of investigations and as a helping hand to investigators. The Cloud offers a cheap and almost limitless computing power and storage space for data which can be leveraged to commit either new or old crimes and host related traces. Conversely, the Cloud can help forensic examiners to find clues better and earlier than traditional analysis applications, thanks to its dramatically improved evidence processing capabilities. In both cases, a new arsenal of software tools needs to be made available. The development of this novel weaponry and its technical and legal implications from the point of view of repeatability of technical assessments is discussed throughout the following pages and constitutes the unprecedented contribution of this work

Studio e implementazione di tecniche di Hand Eye Calibration di un Braccio Robotico

La tesi indaga il problema di calibrazione Hand Eye, ovvero la trasformazione geometrica fra i diversi sistemi di riferimento della camera e dell'attuatore del robot, presentando il problema ed analizzando le varie soluzioni proposte in letteratura. Viene infine presentata una implementazione realizzata in collaborazione con l'azienda SpecialVideo, implementata utilizzando l'algoritmo proposto da Konstantinos Daniilidis, il quale propone una formulazione del problema sfruttando l'utilizzo di quaternioni duali, risolvendo simultaneamente la parte rotatoria e traslatoria della trasformazione. Si conclude il lavoro con una analisi dell'efficacia del metodo implementato su dati simulati e proponendo eventuali estensioni, allo scopo di poter riutilizzare in futuro il lavoro svolto nel software aziendale, con dati reali e con diversi tipi di telecamere, principalmente camere lineari o laser.

Hand and ultrasonic instrumentation for orthograde root canal treatment of permanent teeth

Root canal treatment is a frequently performed dental procedure and is carried out on teeth in which irreversible pulpitis has led to necrosis of the dental pulp. Removal of the necrotic tissue remnants and cleaning and shaping of the root canal are important phases of root canal treatment. Treatment options include the use of hand and rotary instruments and methods using ultrasonic or sonic equipment. OBJECTIVES: The objectives of this systematic review of randomized controlled trials were to determine the relative clinical effectiveness of hand instrumentation versus ultrasonic instrumentation alone or in conjunction with hand instrumentation for orthograde root canal treatment of permanent teeth. MATERIAL AND METHODS: The search strategy retrieved 226 references from the Cochrane Oral Health Group Trials Register (7), the Cochrane Central Register of Controlled Trials (CENTRAL) (12), MEDLINE (192), EMBASE (8) and LILACS (7). No language restriction was applied. The last electronic search was conducted on December 13th, 2007. Screening of eligible studies was conducted in duplicate and independently. RESULTS: Results were to be expressed as fixed-effect or random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated including both clinical and methodological factors. No eligible randomized controlled trials were identified. CONCLUSIONS: This review illustrates the current lack of published or ongoing randomized controlled trials and the unavailability of high-level evidence based on clinically relevant outcomes referring to the effectiveness of ultrasonic instrumentation used alone or as an adjunct to hand instrumentation for orthograde root canal treatment. In the absence of reliable research-based evidence, clinicians should base their decisions on clinical experience, individual circumstances and in conjunction with patients' preferences where appropriate. Future randomized controlled trials might focus more closely on evaluating the effectiveness of combinations of these interventions with an emphasis on not only clinically relevant, but also patient-centered outcomes.

Prediction of hip and hand fractures in older persons with or without a diagnosis of periodontitis

Purpose: In a prospective study, we assessed if a diagnosis of osteoporosis and periodontitis could predict hip and hand fractures in older persons. Materials and methods: Bone density was assessed by a Densitometer. Periodontitis was defined by evidence of alveolar bone loss. Results: 788 Caucasians (52.4% women, overall mean age: 76 years, S.D. +/- 9.0, range: 62 to 96) were enrolled and 7.4% had a hip/hand fracture in 3 years. Calcaneus PIXI T-values < - 1.6 identified osteoporosis in 28.2% of the older persons predicting a hip/hand fracture with an odds ratio of 3.3:1 (95% CI: 1.9, 5.7, p < 0.001). Older persons with osteoporosis had more severe periodontitis (p < 0.01). Periodontitis defined by >= 30% of sites with >= 5 mm distance between the cemento-enamel junction (CEJ) and bone level (ABL) was found in 18.7% of the older persons predicting a hip/hand fracture with an odds ratio of 1.8:1 (95% CI: 1.0, 3.3, p < 0.05). Adjusted for age, the odds ratio of a hip/hand fracture in older persons with osteoporosis (PIXI T-value <-2.5) and periodontitis was 12.2:1 (95% CI: 3.5, 42.3, p < 0.001). Conclusions: Older persons with osteoporosis and periodontitis have an increased risk for hip/hand fractures

Lesions to primary sensory and posterior parietal cortices impair recovery from hand paresis after stroke

Neuroanatomical determinants of motor skill recovery after stroke are still poorly understood. Although lesion load onto the corticospinal tract is known to affect recovery, less is known about the effect of lesions to cortical sensorimotor areas. Here, we test the hypothesis that lesions of somatosensory cortices interfere with the capacity to recover motor skills after stroke.

A modified DRIL procedure by flow reversal of an aborted distal cephalic vein for critical hand ischaemia

Treatment of dialysis access-related hand ischaemia with preservation of the access remains an issue. We report the case of a patient presenting critical hand ischaemia 2 years after proximalisation of a distal radio-cephalic fistula with preservation of the original access. After valvulotomy, the distal cephalic vein was used as in situ bypass and directly anastomosed to the distal brachial artery, providing a direct flow to the hand. This procedure relieved the hand ischaemia without sacrificing the functioning fistula. Six months later, the fistula and bypass were still patent, showing that flow reversal of a previous fistula can be an efficient strategy to correct dialysis access-related hand ischaemia in selected cases.