69 research outputs found

    Comparison of The Transformation Temperatures of Heat-Activated Nickel-Titanium Orthodontic Archwires By Two Different Techniques

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    Objectives The purpose of this study was to investigate the suitability of the Bend and Free Recovery (BFR) method as a standard test method to determine the transformation temperatures of heat-activated Ni-Ti orthodontic archwires. This was done by determining the transformation temperatures of two brands of heat-activated Ni-Ti orthodontic archwires using the both the BFR method and the standard method of Differential Scanning Calorimetry (DSC). The values obtained from the two methods were compared with each other and to the manufacturer-listed values. Methods Forty heat-activated Ni-Ti archwires from both Rocky Mountain Orthodontics (RMO) and Opal Orthodontics (Opal) were tested using BFR and DSC. Round (0.016 inches) and rectangular (0.019 × 0.025 inches) archwires from each manufacturer were tested. The austenite start temperatures (As) and austenite finish temperatures (Af) were recorded. Results For four of the eight test groups, the BFR method resulted in lower standard deviations than the DSC method, and, overall, the average standard deviation for BFR testing was slightly lower than for DSC testing. Statistically significant differences were seen between the transformation temperatures obtained from the BFR and DSC test methods. However, the Af temperatures obtained from the two methods were remarkably similar with the mean differences ranging from 0.0 to 2.1 °C: Af Opal round (BFR 26.7 °C, DSC 27.6 °C) and rectangular (BFR 27.6 °C, DSC 28.6 °C); Af RMO round (BFR 25.5 °C, DSC 25.5 °C) and rectangular (BFR 28.0 °C, DSC 25.9 °C). Significant differences were observed between the manufacturer-listed transformation temperatures and those obtained with BFR and DSC testing for both manufacturers. Significance The results of this study suggest that the Bend and Free Recovery method is suitable as a standard method to evaluate the transformation temperatures of heat-activated Ni-Ti orthodontic archwires

    Beam Profile Influence on Polymerization Characteristics of Resin-Matrix Composites

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    poster abstractThe objective of this study was to quantify the homogeneity of the beam of light radiated from each of two different light-curing units (LCUs) using beam profiling, and then evaluate the relationship between these beam profiles and polymerization patterns of a resin-matrix composite (RMC). Beam profile and irradiance measurements of one light-emitting diode (LED) and one quartz-tungsten-halogen (QTH) curing unit were collected using a beam-profiler-system and a MARC-RC resin calibrator, respectively. The camera-based beam-profiler-system (BGP-USB-SP620 with 50-mm-lens, Ophir-Spiricon) combined radiant-power-values from an irradiance-probe (cosine-corrector/spectrometer-assembly) to measure beam-homogeneity (the distribution of irradiance-values across the light-beam) for each curing-unit. A mapping approach was used to investigate the polymerization pattern of nano-hybrid RMC samples (5×5×2mm) at various depths utilizing both micro-Raman-spectroscopy (degree-of-conversion, DC) and ethanol softening (cross-link-density, CLD), which was determined using automated-microhardness testing after exposure to ethanol. Two-sample t-tests with unequal-variances were used to compare the LCUs for differences in irradiance (mW/cm2) and radiant-exposure (J/cm2). Comparisons among polymerization by depths with-respect-to LCU were made using paired t-tests and two-sample t-tests as appropriate for the specific depths. The effects at each depth of location on the sample and LCU were tested using mixed-model ANOVA. The LED demonstrated inhomogeneity and significantly higher irradiance values compared to the QTH. Both LCUs demonstrated variations in DC (62-74%) and percent Knoop hardness number (KHN) reduction (33-49%) at different depths and locations. A gradual decrease in KHN occurred from top to bottom in the RMC cured with QTH unlike the LED. A gradual decrease in CLD was exhibited in both LCUs. This study showed that the beam-profile-inhomogeneity of QTH and LED curing-units resulted in localized differences in DC, KHN and CLD of RMC samples at specific depths and locations. However, adequate polymerization of the RMC was achieved at all points when using the LED LCU

    Prevalence and clinical implications of respiratory viruses in stable chronic obstructive pulmonary disease (COPD) and exacerbations: a systematic review and meta-analysis protocol.

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    INTRODUCTION: Both stable chronic obstructive pulmonary disease (COPD) and acute exacerbations represent leading causes of death, disability and healthcare expenditure. They are complex, heterogeneous and their mechanisms are poorly understood. The role of respiratory viruses has been studied extensively but is still not adequately addressed clinically. Through a rigorous evidence update, we aim to define the prevalence and clinical burden of the different respiratory viruses in stable COPD and exacerbations, and to investigate whether viral load of usual respiratory viruses could be used for diagnosis of exacerbations triggered by viruses, which are currently not diagnosed or treated aetiologically. METHODS AND ANALYSIS: Based on a prospectively registered protocol, we will systematically review the literature using standard methods recommended by the Cochrane Collaboration and the Grading of Recommendations Assessment, Development and Evaluation working group. We will search Medline/PubMed, Excerpta Medica dataBASE (EMBASE), the Cochrane Library, the WHO's Clinical Trials Registry and the proceedings of relevant international conferences on 2 March 2020. We will evaluate: (A) the prevalence of respiratory viruses in stable COPD and exacerbations, (B) differences in the viral loads of respiratory viruses in stable COPD vs exacerbations, to explore whether the viral load of prevalent respiratory viruses could be used as a diagnostic biomarker for exacerbations triggered by viruses and (C) the association between the presence of respiratory viruses and clinical outcomes in stable COPD and in exacerbations. ETHICS AND DISSEMINATION: Ethics approval is not required since no primary data will be collected. Our findings will be presented in national and international scientific conferences and will be published in peer reviewed journals. Respiratory viruses currently represent a lost opportunity to improve the outcomes of both stable COPD and exacerbations. Our work aspires to 'demystify' the prevalence and clinical burden of viruses in stable COPD and exacerbations and to promote clinical and translational research. PROSPERO REGISTRATION NUMBER: CRD42019147658

    Inflammatory myofibroblastic tumor of epididymis: a case report and review of literature

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    Background Epididymal inflammatory myofibroblastic tumor, also known by various other synonyms is a rare benign disease. Only eight cases have been reported to date. The most common presentation is a scrotal mass of variable duration. For a scrotal mass it is difficult to distinguish a benign or malignant etiology, in addition to the origin whether from testis or epididymis. As a result the definitive diagnosis can only be established by surgical exploration. Case presentation We report the ninth case of epididymal IMT who based on clinical and radiological findings underwent radical orchidectomy, with the histology suggestive of inflammatory myofibroblastic tumor. At 4 years follow up the patient is free of disease recurrence. Conclusion IMT though rare should be considered in the differential diagnosis of epididymal mass. Clinically it is often difficult to distinguish the origin of mass and even though the disease has benign nature and course it is crucial to counsel patients for orchidectomy as definitive diagnosis is established on surgical exploration

    Thyroid Ultrasound Findings in Children from Three Japanese Prefectures: Aomori, Yamanashi and Nagasaki

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    Due to the likelihood of physical and mental health impacts following the unprecedented accident at the Fukushima Daiichi Nuclear Power Plant, the Fukushima prefectural government decided to conduct the Fukushima Health Management Survey to assist in the long-term health management of residents. This included thyroid ultrasound examination for all children in Fukushima. For appropriate evaluation of ultrasound screening of the thyroid, it is important to understand its reference data of thyroid findings in children in general. In order to analyze the frequencies of specific thyroid findings, we conducted ultrasound screening of the thyroid by the same procedures as used in Fukushima in 4,365 children, aged 3 to 18 years, from three Japanese prefectures. Overall, thyroid cysts were identified in 56.88% and thyroid nodules in 1.65% of the participants. Thyroid cysts and nodules with a maximum diameter of more than 5 mm were identified in 4.58% and 1.01%, respectively, and age-adjusted prevalences were 3.82% and 0.99%, respectively. Although the prevalence of cysts and nodules varied among the examination areas, no significant differences were observed among the three examination areas in the prevalence of cysts and nodules with a maximum diameter of more than 5 mm. Also, the prevalence of thyroid cysts and nodules, especially those with a maximum diameter of more than 5 mm, significantly increased with age, and showed a female predominance. We also identified ectopic thymus (1.95%), diffuse goiter (1.40%), ultimobranchial body (0.73%), lymph node swelling (0.21%) and thyroid agenesis (0.05%). This is the first ultrasound description of the age-adjusted prevalence of thyroid cysts and nodules, or of the prevalence of abnormalities other than cysts and nodules, such as ectopic thymus, in relation to age, in the general Japanese child population. We contend that this can provide relevant information for the Fukushima Health Management Survey and future population studies

    The common cold: Potential for future prevention or cure topical collection on rhinosinusitis

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    The common cold is the most frequent, although generally mild, human disease. Human Rhinoviruses are the prevalent causative agents, but other viruses are also implicated. Being so common, viral colds, have significant implications on public health and quality of life, but may also be life-threatening for vulnerable groups of patients. Specific diagnosis and treatment of the common cold still remain unmet needs. Molecular diagnostic techniques allow specific detection of known pathogens as well as the identification of newly emerging viruses. Although a number of medications or natural treatments have been shown to have some effect, either on the number or on the severity of common colds, no single agent is considerably effective. Virus-specific management remains in most cases a challenging potential as many factors have to be taken into account, including the diversity of the viral genomes, the heterogeneity of affected individuals, as well as the complexity of this long standing host-virus relationship. © 2014 Springer Science+Business Media New York

    Contributing factors to the development of childhood asthma: Working toward risk minimization

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    Asthma is the most common chronic disease in childhood, and considerable research has been undertaken to find ways to prevent its development and reduce its prevalence. For such interventions to be successful, risk factors for asthma emergence should be identified and clearly defined. Data are robust for some of them, including atopy, viral infections and exposure to airborne irritants, whereas it is less conclusive for others, such as aeroallergen exposure and bacterial infections. Several interventions for asthma prevention, including avoidance and pharmacotherapy, have been attempted. However, most of them have furnished equivocal results. Various issues hinder the establishment of risk factors for asthma development and reduce the effectiveness of interventions, including the complexity of the disease and the fluidity of the developing systems in childhood. In this review, we revisit the evidence on pediatric asthma risk factors and prevention and discuss issues that perplex this field. © 2015 Informa UK, Ltd

    The virome in allergy and asthma: A nascent, ineffable player

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    Allergic diseases can be affected by virus-host interactions and are increasingly linked with the tissue-specific microbiome. High-throughput metagenomic sequencing has offered the opportunity to study the presence of viruses as an ecologic system, namely, the virome. Even though virome studies are technically challenging conceptually and analytically, they are already producing novel data expanding our understanding of the pathophysiologic mechanisms related to chronic inflammation and allergy. The importance of interspecies and intraspecies interactions is becoming apparent, as they can significantly, directly or indirectly, affect the host's response and antigenic state. Here, we emphasize the challenges and potential insights related to study of the virome in the context of allergy and asthma. We review the limited number of studies that have investigated the virome in these conditions, underlining the need for prospective, repeated sampling designs to unravel the virome's impact on disease development and its interplay with microbiota and immunity. The potential therapeutic use of bacteriophages, which are highly complex components of the virome, is discussed. There is clearly a need for further in-depth investigation of the virome as a system in allergic diseases
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