559 research outputs found

    Erosion—diagnosis and risk factors

    Get PDF
    Dental erosion is a multifactorial condition: The interplay of chemical, biological and behavioural factors is crucial and helps explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors, e.g. pH, titratable acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties. Biological factors such as saliva, acquired pellicle, tooth structure and positioning in relation to soft tissues and tongue are related to the pathogenesis of dental erosion. Furthermore, behavioural factors like eating and drinking habits, regular exercise with dehydration and decrease of salivary flow, excessive oral hygiene and, on the other side, an unhealthy lifestyle, e.g. chronic alcoholism, are predisposing factors for dental erosion. There is some evidence that dental erosion is growing steadily. To prevent further progression, it is important to detect this condition as early as possible. Dentists have to know the clinical appearance and possible signs of progression of erosive lesions and their causes such that adequate preventive and, if necessary, therapeutic measures can be initiated. The clinical examination has to be done systematically, and a comprehensive case history should be undertaken such that all risk factors will be reveale

    Erosion—diagnosis and risk factors

    Get PDF
    Dental erosion is a multifactorial condition: The interplay of chemical, biological and behavioural factors is crucial and helps explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors, e.g. pH, titratable acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties. Biological factors such as saliva, acquired pellicle, tooth structure and positioning in relation to soft tissues and tongue are related to the pathogenesis of dental erosion. Furthermore, behavioural factors like eating and drinking habits, regular exercise with dehydration and decrease of salivary flow, excessive oral hygiene and, on the other side, an unhealthy lifestyle, e.g. chronic alcoholism, are predisposing factors for dental erosion. There is some evidence that dental erosion is growing steadily. To prevent further progression, it is important to detect this condition as early as possible. Dentists have to know the clinical appearance and possible signs of progression of erosive lesions and their causes such that adequate preventive and, if necessary, therapeutic measures can be initiated. The clinical examination has to be done systematically, and a comprehensive case history should be undertaken such that all risk factors will be revealed

    High Precision Surface Structuring with Ultra-Short Laser Pulses and Synchronized Mechanical Axes

    Get PDF
    For surface and 3D structuring in a 2.5D process, ultra-short pulsed laser systems are mostly used in combination with mechanical axes, whereas the mechanical axes can include electrical motor as well as beam deflecting systems like a galvo scanner. The motion of the axes is synchronized with the clock of the laser pulses, by a modification of the electronic axes control. This work shows the scalability of the ablation process up to MHz-regime in relation to surface quality and ablation efficiency, drilling of thin foils without any heat accumulation and deforming problems of the foil. Furthermore the transfer of the machining strategy from a synchronized galvo scanner to a rotating cylinder setup is shown

    Predicting Fluid Intelligence of Children using T1-weighted MR Images and a StackNet

    Full text link
    In this work, we utilize T1-weighted MR images and StackNet to predict fluid intelligence in adolescents. Our framework includes feature extraction, feature normalization, feature denoising, feature selection, training a StackNet, and predicting fluid intelligence. The extracted feature is the distribution of different brain tissues in different brain parcellation regions. The proposed StackNet consists of three layers and 11 models. Each layer uses the predictions from all previous layers including the input layer. The proposed StackNet is tested on a public benchmark Adolescent Brain Cognitive Development Neurocognitive Prediction Challenge 2019 and achieves a mean squared error of 82.42 on the combined training and validation set with 10-fold cross-validation. In addition, the proposed StackNet also achieves a mean squared error of 94.25 on the testing data. The source code is available on GitHub.Comment: 8 pages, 2 figures, 3 tables, Accepted by MICCAI ABCD-NP Challenge 2019; Added ND

    Multi-objective engineering shape optimization using differential evolution interfaced to the Nimrod/O tool

    Get PDF
    This paper presents an enhancement of the Nimrod/O optimization tool by interfacing DEMO, an external multiobjective optimization algorithm. DEMO is a variant of differential evolution – an algorithm that has attained much popularity in the research community, and this work represents the first time that true multiobjective optimizations have been performed with Nimrod/O. A modification to the DEMO code enables multiple objectives to be evaluated concurrently. With Nimrod/O’s support for parallelism, this can reduce the wall-clock time significantly for compute intensive objective function evaluations. We describe the usage and implementation of the interface and present two optimizations. The first is a two objective mathematical function in which the Pareto front is successfully found after only 30 generations. The second test case is the three-objective shape optimization of a rib-reinforced wall bracket using the Finite Element software, Code_Aster. The interfacing of the already successful packages of Nimrod/O and DEMO yields a solution that we believe can benefit a wide community, both industrial and academic

    Long-term outcome after surgical intervention and interventional procedures for the management of Takayasu’s arteritis in children

    Get PDF
    ObjectiveThere is little information available on the results of reconstructive arterial surgery for Takayasu’s arteritis in children. This study evaluates midterm to long-term outcome after surgical, as well as interventional, procedures.MethodsFrom 1984 through 2004, 10 children (5 boys and 5 girls; age, 12.7 ± 2.6 years) with Takayasu’s arteritis were referred to our center. Baseline cardiovascular assessment included contrast angiography (n = 4), magnetic resonance imaging–angiography (n = 3), and combined contrast angiography plus magnetic resonance imaging–angiography (n = 3). Two patients had disease confined to the thoracic aorta, 4 had disease confined to the abdominal aorta, and 4 had combined thoracoabdominal aortic disease. Steno-occlusive lesions were predominant in 92% of cases. Seven patients were maintained on steroid therapy throughout the follow-up period. Eight children underwent complex surgical procedures, 1 patient had balloon dilatation of the renal and mesenteric arteries, and 1 patient had combined vascular surgery with percutaneous transluminal angioplasty. Overall, 24 grafts (polytetrafluoroethylene, Dacron grafts, and cryopreserved homografts) were implanted in various locations.ResultsThere were no perioperative deaths. Arterial hypertension regressed in all patients, and cardiac function normalized in all 4 patients with dilative cardiomyopathy. Over a 20-year period, 1 patient presented with sudden death and 2 showed nonfatal disease progression, one of whom required surgical reintervention. The occlusion rate was higher in Dacron grafts.ConclusionsOur study shows that despite the extent and severity of vascular lesions, children with Takayasu’s arteritis could benefit from reconstructive surgery, with low mortality, morbidity, and satisfactory long-term results

    Foetal echocardiographic assessment of borderline small left ventricles can predict the need for postnatal intervention

    Get PDF
    Abstract Background We sought to prospectively determine foetal echocardiographic factors associated with neonatal interventions in borderline hypoplastic left ventricles. Methods Foetuses were included who had a left ventricle that was 2-4 standard deviations below normal for length or diameter and had forward flow across the mitral and aortic valves. Factors associated with an intervention in the first month of life or no need for intervention were sought using univariate and multivariate logistic regression models. Results From 2005 to 2008, 47 foetuses meeting the criteria had an additional diagnosis (+foetal coarctation/+transverse arch hypoplasia): atrioventricular septal defect 7 (+2/+0), double outlet right ventricle 2 (+0/+0), Shone's complex 19 (+9/+4), and ventricular disproportion 19 (+13/+11; 4 both). There were seven pregnancies terminated, three foetal demises, and five had compassionate care. There were 32 livebirths that either had a biventricular repair (n = 20, n = 2 dead), univentricular palliation (n = 2, both alive), or no intervention (n = 9). Overall survival of livebirths to 6 months of age was 79%. Factors associated with early intervention on first foetal echocardiogram were: obstructed or retrograde arch flow (p = 0.08, odds ratio 3.3), coarctation (p = 0.05, odds ratio 11.4), and left ventricle outflow obstruction (p = 0.05, odds ratio 12.5). Neonatal factors included: Shone's diagnosis (p = 0.02, odds ratio 4.9), bicuspid aortic valve (p = 0.005, odds ratio 11.7), and larger tricuspid valve z-score (p = 0.05, odds ratio 3.6). A neonatal factor associated with no intervention was a larger mitral valve z-score (mean −3.8 versus −4.2 intervention group, p = 0.04, odds ratio 2.8). Discussion The need for early intervention in foetuses with borderline hypoplastic left ventricle can be predicted by foetal echocardiograph

    Leprosy Post-Exposure Prophylaxis (LPEP) Programme : study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin

    Get PDF
    Introduction: The reported number of new leprosy patients has barely changed in recent years. Thus, additional approaches or modifications to the current standard of passive case detection are needed to interrupt leprosy transmission. Large-scale clinical trials with single dose rifampicin (SDR) given as post-exposure prophylaxis (PEP) to contacts of newly diagnosed patients with leprosy have shown a 50–60% reduction of the risk of developing leprosy over the following 2 years. To accelerate the uptake of this evidence and introduction of PEP into national leprosy programmes, data on the effectiveness, impact and feasibility of contact tracing and PEP for leprosy are required. The leprosy post-exposure prophylaxis (LPEP) programme was designed to obtain those data. Methods and analysis: The LPEP programme evaluates feasibility, effectiveness and impact of PEP with SDR in pilot areas situated in several leprosy endemic countries: India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. Complementary sites are located in Brazil and Cambodia. From 2015 to 2018, contact persons of patients with leprosy are traced, screened for symptoms and assessed for eligibility to receive SDR. The intervention is implemented by the national leprosy programmes, tailored to local conditions and capacities, and relying on available human and material resources. It is coordinated on the ground with the help of the in-country partners of the International Federation of Anti-Leprosy Associations (ILEP). A robust data collection and reporting system is established in the pilot areas with regular monitoring and quality control, contributing to the strengthening of the national surveillance systems to become more action-oriented. Ethics and dissemination: Ethical approval has been obtained from the relevant ethics committees in the countries. Results and lessons learnt from the LPEP programme will be published in peer-reviewed journals and should provide important evidence and guidance for national and global policymakers to strengthen current leprosy elimination strategies
    • …
    corecore