234 research outputs found

    Microtensile bond strength of ceramic to resin using different silanes

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    Oral Session - Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms: 9. Cement Adhesion to Ceramics: no. 27OBJECTIVES: The purpose of this study was to assess the micro-tensile bond strength of a leucite-reinforced feldspathic ceramic to a resin cement using different types of silane primers. METHODS: 18 leucite-reinforced feldspathic ceramic blocks (Ceramco II, Dentsply) in dimensional of 6×6×6 mm were fabricated. The ceramic blocks were ground on wet SiC papers and then cleansed ultrasonically in distilled water. The bonding ceramic surfaces were treated with different silane solutions as follows: Commercial silane as control: Monobond S (Ivoclar-Vivadent); methacryloxypropyl silane and experimental silanes with two concentrations (1% and 2.5%): amino, isocyanate, styryl, and acrylate silanes. The silane application method consisted of ...postprin

    Minimally invasive glaucoma surgery: comparison of iStent with iStent inject in primary open angle glaucoma

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    Importance:Minimally invasive glaucoma surgery has gained significant traction in recent years. This study evaluates the first‐ and second‐generation trabecular micro‐bypass stents “iStent” and “iStent inject”.Background:To evaluate and compare the effect of a single iStent and double iStent inject in primary open angle glaucoma.Design:Prospective comparative case series.Participants:Primary open angle glaucoma patients undergoing trabecular micro‐bypass stent insertion combined with cataract surgery.Methods:Baseline demographic information, preoperative, intraoperative and postoperative outcomes including intraocular pressure (IOP), visual acuity, reliance on glaucoma medication and complications were collected and analysed.Main Outcome Measures:Primary, secondary and tertiary outcome measures were consecutively defined as an IOP of ≤18 mmHg with zero medications, an IOP of ≤18 mmHg with reduced medications or a 20% reduction in IOP with or without medication.Results:The study comprised 145 eyes in the iStent and 100 eyes in the iStent inject group. At 12 months, 56.0% of the iStent and 51.3% of the iStent inject eyes had achieved primary success and 63.1% and 57.7% secondary success. The mean postoperative IOP was 16.6 mmHg in iStent and 16.9 mmHg in iStent inject. Survival analysis demonstrated a greater incidence of failure in the iStent inject beyond 5 months.Conclusions and Relevance:Both trabecular micro‐bypass stents in this study were effective in reducing IOP and the burden of medication when combined with cataract surgery. There was no statistically significant difference between the two groups across our outcome measures although the iStent inject required earlier recommencement of medications for optimal IOP control

    Assessment of Bond Strength between Metal Brackets and Non-Glazed Ceramic in Different Surface Treatment Methods

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    Objective: The aim of this study was to evaluate the bond strength between metal brackets and non-glazed ceramic with three different surface treatment methods.Materials and Methods: Forty-two non-glazed ceramic disks were assigned into three groups. Group I and II specimens were etched with 9.5% hydrofluoric acid. Subsequently in group I, silane and adhesive were applied and in group II, bonding agent was used only.In group III, specimens were treated with 35% phosphoric acid and then silane and adhesive were applied. Brackets were bonded with light-cured composites. The specimens were stored in water in room temperature for 24 hours and then thermocycled 500 times between 5°C and 55°C.Results: The difference of tensile bond strength between groups I and III was not significant(P=0.999). However, the tensile bond strength of group II was significantly lower than groups I, and III (P<0.001). The adhesive remnant index scores between the threegroups had statistically significant differences (P<0.001).Conclusion: With the application of scotch bond multi-purpose plus adhesive, we can use phosphoric acid instead of hydrofluoric acid for bonding brackets to non-glazed ceramic restorations

    Quality assessment of services provided by health centers in Mashhad, Iran: SERVQUAL versus HEALTHQUAL scales

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    Background: Primary health care is the entry point to the health-care system and regarded as an essential step to achieving universal health coverage. The present study aimed at evaluating the quality of health-care services provided in health centers in Mashhad, Iran. Methods: This was a cross-sectional study implemented among 200 health service users who were referring to four health centers in Mashhad during January to June 2019. The quality of services in health centers was evaluated with the SERVQUAL and HEALTHQUAL models. Data was analyzed by employing paired t-test and independent sample t-test using SPSS version 16 software. The Levene test was used for examining the equality of variance (homogeneity). Significance level of all the tests was considered when p � 0.05. Results: According to the results of SERVQUAL questionnaire, the average scores of health service users� expectations and perceptions were 4.97 and 3.26, respectively, and the quality gap in the provided services was equal to � 1.7. Based on HEALTHQUAL questionnaire, the average scores of health service users� perception and expectations were 4.72 and 3.25, respectively, and the quality gap in the provided services was equal to � 1.16. Empathy was the highest quality dimension (� 2.019) based on SERVQUAL model, and efficiency dimension was the highest based on HEALTHQUAL model (� 1.761). Conclusions: The findings of the current study showed a negative gap between the service users� expectations and perceptions in both models. Therefore, the results of this study helps the health managers and policymakers to plan effective interventions for improving the provided services emphasizing the dimensions with the wider gaps. © 2021, The Author(s)

    CAIDE Dementia Risk Score, Alzheimer and cerebrovascular pathology : a population-based autopsy study

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    Background. CAIDE Dementia Risk Score is a tool for estimating dementia risk in the general population. Its longitudinal associations with Alzheimer or vascular neuropathology in the oldest old are not known. Aim. To explore the relationship between CAIDE Dementia Risk Score at baseline and neuritic plaques, neurofibrillary tangles, cerebral infarcts and cerebral amyloid angiopathy (CAA) after up to 10-year follow-up in the Vantaa 85+ population. Methods. Study population included 149 participants aged 85 years, without dementia at baseline, and with available clinical and autopsy data. Methenamine silver staining was used for beta-amyloid and modified Bielschowsky method for neurofibrillary tangles and neuritic plaques. Macroscopic infarcts were identified from cerebral hemispheres, brain-stem and cerebellum slices. Standardized methods were used to determine microscopic infarcts, CAA and alpha-synuclein pathologies. The CAIDE Dementia Risk Score was calculated based on scores for age, sex, BMI, total cholesterol, systolic blood pressure, physical activity and APOE epsilon 4 carrier status (range 0-18 points). Results. A CAIDE Dementia Risk Score above 11 points was associated with more cerebral infarctions up to 10 years later: OR (95% CI) was 2.10 (1.06-4.16). No associations were found with other neuropathologies. Conclusion. In a population of elderly aged 85 years, higher CAIDE Dementia Risk Score was associated with increased risk of cerebral infarcts.Peer reviewe

    Radio Location of Partial Discharge Sources: A Support Vector Regression Approach

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    Partial discharge (PD) can provide a useful forewarning of asset failure in electricity substations. A significant proportion of assets are susceptible to PD due to incipient weakness in their dielectrics. This paper examines a low cost approach for uninterrupted monitoring of PD using a network of inexpensive radio sensors to sample the spatial patterns of PD received signal strength. Machine learning techniques are proposed for localisation of PD sources. Specifically, two models based on Support Vector Machines (SVMs) are developed: Support Vector Regression (SVR) and Least-Squares Support Vector Regression (LSSVR). These models construct an explicit regression surface in a high dimensional feature space for function estimation. Their performance is compared to that of artificial neural network (ANN) models. The results show that both SVR and LSSVR methods are superior to ANNs in accuracy. LSSVR approach is particularly recommended as practical alternative for PD source localisation due to it low complexity

    Epidermal Neural Crest Stem Cell (EPI-NCSC)—Mediated Recovery of Sensory Function in a Mouse Model of Spinal Cord Injury

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    Here we show that epidermal neural crest stem cell (EPI-NCSC) transplants in the contused spinal cord caused a 24% improvement in sensory connectivity and a substantial recovery of touch perception. Furthermore we present a novel method for the ex vivo expansion of EPI-NCSC into millions of stem cells that takes advantage of the migratory ability of neural crest stem cells and is based on a new culture medium and the use of microcarriers. Functional improvement was shown by two independent methods, spinal somatosensory evoked potentials (SpSEP) and the Semmes-Weinstein touch test. Subsets of transplanted cells differentiated into myelinating oligodendrocytes. Unilateral injections of EPI-NCSC into the lesion of midline contused mouse spinal cords elicited bilateral improvements. Intraspinal EPI-NCSC did not migrate laterally in the spinal cord or invade the spinal roots and dorsal root ganglia, thus implicating diffusible factors. EPI-NCSC expressed neurotrophic factors, angiogenic factors, and metalloproteases. The strength of EPI-NCSC thus is that they can exert a combination of pertinent functions in the contused spinal cord, including cell replacement, neuroprotection, angiogenesis and modulation of scar formation. EPI-NCSC are uniquely qualified for cell-based therapy in spinal cord injury, as neural crest cells and neural tube stem cells share a higher order stem cell and are thus ontologically closely related

    Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet

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    Osteoporosis and low bone mineral density affect millions of Americans. The majority of adults in North America have insufficient intake of vitamin D and calcium along with inadequate exercise. Physicians are aware that vitamin D, calcium and exercise are essential for maintenance of bone health. Physicians are less likely to be aware that dietary insufficiencies of magnesium, silicon, Vitamin K, and boron are also widely prevalent, and each of these essential nutrients is an important contributor to bone health. In addition, specific nutritional factors may improve calcium metabolism and bone formation. It is the authors’ opinion that nutritional supplements should attempt to provide ample, but not excessive, amounts of factors that are frequently insufficient in the typical American diet
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