1,888 research outputs found
Avaliação in vitro do efeito da desproteinização da dentina decídua de humanos na união de sistemas adesivos
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Odontologia, Florianópolis, 2009.O objetivo deste estudo, in vitro, foi avaliar a resistência de união à microtração e a nanoinfiltração, após desproteinização da dentina decídua humana. Foram utilizadas coroas de molares decíduos hígidos, as quais tiveram a superfície oclusal desgastada com lixas de carbeto de silício, até a completa exposição da superfície dentinária, e para padronização da smear layer. Os espécimes foram distribuídos em seis grupos, de acordo com o tipo de tratamento (condicionamento ácido - CA ou CA + hipoclorito de sódio - NaOCl) e os sistemas adesivos: One Step Plus - Bisco (OSP), Single Bond - 3M ESPE (SB), Prime & Bond 2.1 - Dentsply (PB). Para o procedimento de desproteinização foi utilizado hipoclorito de sódio 10% por 30s. Os sistemas adesivos e a resina (Filtek Z 250 - 3M ESPE) foram aplicados de acordo com as recomendações dos fabricantes e os espécimes armazenados em água destilada (37ºC/24h). As coroas foram seccionadas obtendo-se palitos (0,8mm2), os quais foram imediatamente submetidos ao teste de resistência à microtração (Instron - 0,5mm/min), até fratura dos corpos-de-prova. Os valores obtidos foram analisados por ANOVA e teste de Tukey (p<0,05). Os corpos-de-prova foram levados ao microscópio eletrônico de varredura (MEV), para visualização do tipo de fratura e os dados submetidos ao teste de Kruskal-Wallis (p<0,05).A nanoinfiltração foi avaliada utilizando-se palitos e nitrato de prata amoniacal como marcador químico. A deposição da prata foi visualizada ao MEV e analisada de duas formas: 1. Em porcentagem (%), em três regiões do palito, utilizando-se espectometria por energia dispersa por raio-x (EDS); 2. Atribuição de escores pela avaliação das fotomicrografias obtidas ao MEV. Os dados (%) foram analisados por ANOVA e teste de Tukey (p<0,05) e os escores submetidos aos testes de Kruskal-Wallis e U de Mann-Whitney (p<0,05).Os valores médios obtidos para o teste de microtração sem desproteinização foram [MPa(DP)]: PB - 35,95(6,12); SB - 28,82(6,38); OSP - 24,59(6,10); e após desproteinização: PB - 41,47(6,79); OSP - 31,09(9,16); SB - 25,55(7,23). Os padrões de fratura mais comumente encontrados foram coesiva do adesivo e mista, para todos os grupos. A nanoinfiltração, avaliada por porcentagem, apresentou diferença significante para as variáveis tratamento e adesivo. A desproteinização da dentina condicionada reduziu significativamente a infiltração para o adesivo OSP. Para a variável sistema adesivo, na análise por porcentagem e por escores, o adesivo SB apresentou significativamente maior infiltração pelo nitrato de prata quando comparado ao OSP e PB, que foram similares entre si. Conclui-se que a resistência adesiva não foi influenciada pela remoção do colágeno exposto pelo condicionamento ácido e que a nanoinfiltração não foi evitada pela desproteinização dentinária
Racism, Eh ? A Critical Inter-Disciplinary Anthology of Race and Racism in Canada
No full text"Racism, Eh? is the first publication that examines racism within the broad Canadian context. It focuses fundamentally on two key aspects of identity or identification – race and nationality – and the complex ways in which they intersect" -- Publisher's website
All-fibre-optic clock recovery from non-return-to-zero format data
No full textThe author; demonstrate an all-optical clock recovery scheme from non-return-to-zero format data, with an asymmetric Mach-Zehnder interferometer and a mode-locked Er-doped fibre laser. Since this scheme consists of an all-fibre device, the clock recovery bandwidth can extend to the terahertz region. Such all-optical clock recovery techniques will find application in ultra-high speed all-optical communication systems
Navigating global-local tensions in accountability/autonomy policies: Comparative case studies in 'Asian' universities
No full textThe twin policy domains of accountability and autonomy have featured in recent education reforms in many countries, signalling new relationships between governments and educational institutions. Despite different national and localised contexts, a number of common 'global' trends have been identified. However, simultaneously context-specific differences are also evident. For us, the concept of 'globalisation', when it implies policy homogenisation, is too blunt an instrument to critically analyse these major reforms. We would argue that there are still too few studies on globalisation processes grounded in detailed examinations of particular historical times and geographical spaces. Our research is located within the tensions between global commonalities and localised differences.
This paper reports research on changing accountability and autonomy in higher education in three 'Asian' countries. Empirical data has been collected in the People's Republic of China, Hong Kong and Singapore in an attempt to begin to redress a 'Western' hegemony in such research. Within each national context two different types of universities became case study sites for the analysis of both commonalities and differences in accountability and autonomy policies and practices. The current paper focuses in particular on the conceptual and methodological framings of the research and presents some preliminary findings
A Nanopower 95.6% Efficiency Voltage Regulator with Adaptive Supply-Switching for Energy Harvesting Applications
No full textA nanopower highly efficient low-dropout (LDO) regulator for energy harvesting (EH) applications is presented in this paper. The LDO is fully autonomous with a bandgap reference (BGR) featuring a novel bandgap supply-switching (SS) topology, an over-voltage protection (OVP), a under-voltage lockout (UVLO) and control block to obtain stable output and robust cold-start. The system provides configurable voltage supply (1.1 \sim2V) for potential loads, while consuming as low as 66 nW power. The entire system achieves a peak power efficiency of 95.6% at Vout=2V and I-{\iota-{oad}}=100\muA.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentatio
External validation of anti-Müllerian hormone based prediction of live birth in assisted conception
No full text<p>Background - Chronological age and oocyte yield are independent determinants of live birth in assisted conception. Anti-Müllerian hormone (AMH) is strongly associated with oocyte yield after controlled ovarian stimulation. We have previously assessed the ability of AMH and age to independently predict live birth in an Italian assisted conception cohort. Herein we report the external validation of the nomogram in 822 UK first in vitro fertilization (IVF) cycles.</p>
<p>Methods - Retrospective cohort consisting of 822 patients undergoing their first IVF treatment cycle at Glasgow Centre for Reproductive Medicine. Analyses were restricted to women aged between 25 and 42 years of age. All women had an AMH measured prior to commencing their first IVF cycle. The performance of the model was assessed; discrimination by the area under the receiver operator curve (ROCAUC) and model calibration by the predicted probability versus observed probability.</p>
<p>Results - Live births occurred in 29.4% of the cohort. The observed and predicted outcomes showed no evidence of miscalibration (p = 0.188). The ROCAUC was 0.64 (95% CI: 0.60, 0.68), suggesting moderate and similar discrimination to the original model. The ROCAUC for a continuous model of age and AMH was 0.65 (95% CI 0.61, 0.69), suggesting that the original categories of AMH were appropriate.</p>
<p>Conclusions - We confirm by external validation that AMH and age are independent predictors of live birth. Although the confidence intervals for each category are wide, our results support the assessment of AMH in larger cohorts with detailed baseline phenotyping for live birth prediction.</p>
Clinical Outcomes One Year and Beyond After Combination Sirolimus-Eluting Endothelial Progenitor Cell Capture Stenting During Primary Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction
No full text10.1016/j.carrev.2018.11.004Cardiovascular Revascularization Medicine209739-74
Treating Very Long Coronary Artery Lesions in the Contemporary Drug-Eluting-Stent Era: Single Long 48 mm Stent Versus Two Overlapping Stents Showed Comparable Clinical Outcomes
No full text10.1016/j.carrev.2020.02.005Cardiovascular Revascularization Medicine2191115-111
A graph-based model framework for steady-state load flow problems of general multi-carrier energy systems
No full textCoupling single-carrier networks into multi-carrier energy systems (MESs) has recently become more important. Conventional load flow models for the separate single-carrier networks are not able to capture the full extend of the coupling. Recently, different models for multi-carrier energy networks have been proposed, either using the energy hub (EH) concept, or using a case specific approach. Although the EH concept can be applied to a general MES, it is unclear how the EH should be represented in the graph of the MES. On the other hand, the case specific approaches are not easily applicable to general MESs. This paper presents a graph-based framework for steady-state load flow analysis of general MESs. Furthermore, the effect of coupling on the resulting integrated system of equations is investigated. The proposed framework is validated using a small MES. This example shows that our framework is applicable to a general MES, and that it generalizes both the EH concept and the case specific approach.Numerical Analysi
Design and Development of an RF Energy Harvesting Wireless Sensor Node (EH-WSN) for Aerospace Applications
No full textAbstractNumerous applications of wireless sensor networks are constrained by the limited battery power of the sensors. The power consumption of processors and microcontrollers could be scaled down dramatically with the new advances in microelectronics. This reduction gives rise to the possibility of energy harvesting sources to power wireless sensor nodes. In this paper a summary is given of our ongoing research work on RF Energy Harvesting Wireless Sensor Node (EH-WSN) which can plug-in to the already developed Wireless Instrumentation System (WIS) for aerospace applications. Present WSN's which are powered from battery have limited operational lifetime. While energy harvesting has the potential to enable near-perpetual system operation, design of which is a complex trade-off due to the interaction of numerous factors such as the characteristics of the energy source, power supply requirements, power management futures, WSN application behaviour, chemistry and capacity of batteries used etc. In this work, we have identified a suitable power harvesting cum battery management scheme which harvests power consistently and deterministically from a secondary RF source which can be used even in harsh real-time applications. Using a RF power harvesting receiver IC and a compact power management cum storage circuit, we establish the test bed and conduct a series of experiments to verify the effectiveness of the proposed scheme. We have demonstrated continuous operation of the sensor node at an operating distance of 2 meters from the RF power source for a data rate of 240 sps. This is achieved by using special synchronized MAC protocol, low power techniques, usage of low leakage components and systematic coding of the micro controller firmware. This paper provides an insight into how various power reduction techniques can be used and orchestrated such that satisfactory performance can be achieved for a given energy budget
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