1,472 research outputs found
Melanoma
No full textMelanoma is a relatively common neoplasm which is increasing in incidence. Melanoma appears as a variegated irregular maculopapular
lesion usually on the skin, but possibly on mucosae, conjunctiva, orbit, nails and oesophagus. They may be black,
brown, red-blue, grey or unpigmented. Histologically they are larger than nevi cells with irregular nucleoli and eosinophilic
nucleoli. [1] Melanoma incidence in Malta is lower than that in northern Europe and is similar to that in southern Europe. However,
incidence appears to be increasing. . In a study done between the years 2000-2004 the rates for invasive melanoma were
of 8.81 per 100,000 (males) and 7.29 per 100,000 (females). A relatively high proportion of patients present with thick lesions
emphasising the importance of continued efforts to diagnose cases earlier. [2]
Aim:
The aim of this article is to make the reader aware of the importance of early detection and prevention of melanoma, to highlight
the risk factors for developing melanoma and to outline the way in which melanoma is diagnosed, treated and followed up.peer-reviewe
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
Metals in Sediment and Phragmites Australis (Common Reed) from Tisza River, Serbia
No full textIn this study the concentrations of metals were investigated in Phragmites australis (Cav.) Trin. eh Steud. 1841 and sediment samples from the bed of the River Tisza in Serbia. Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn levels were analyzed using inductively coupled plasma - optical emission spectrometry. The sediment samples contained elevated concentrations of cadmium, chromium, copper, nickel and zinc. The increased concentration of these metals had no significant effect on wildlife of the river Tisza as the determined concentrations of the metals tested in the comon reed do not exceed the threshold of phytotoxicity. The research proved a strong positive correlation between the concentrations of metals in the sediment and all common reed organs (rhizome, stem and leave). Accumulated metals in the common reed are not distributed evenly, but there are target organs for bioaccumulation. Concentrations in belowground organs were usually higher than aboveground organs, and the general decreasing trend of element content was rhizome gt leaves gt stems
Nitrogen removal from landfill leachate in constructed wetlands with reed and willow: Redox potential in the root zone
No full textThis study investigated the effects of reed and willow on bioremediation of landfill leachate in comparison with an unplanted control by measuring redox potential levels in the rhizosphere of microcosm systems in a greenhouse. Plants had a significant influence on redox potential relative to the plant-less system. Redox potential in the reed rhizosphere was anoxic (mean -102 +/- 85 mV), but it was the least negative, being significantly higher than in the willow (mean -286 +/- 118 mV), which had the lowest Eh. Redox potential fluctuated significantly in the willow rhizosphere during daylight hours, with large decreases in the morning. Levels of NH4+ decreased significantly in the first day of the experiment and remained at similar low levels in all three variants for the next four weeks of the experiment. Following this removal of ammonia significant peaks in NO2- occurred in the control and reed tanks on the 1st day, and again on 14th day in the control tank up to 13 mg/dm(3). In the willow tank there was also one significant peak of NO2- in the first week, but only up to 0.5 mg/dm(3). Significant accumulation, within 21 days of NO3- in all variants was observed, but in tanks with reed and willow the concentration of NO3- remained significantly lower (<4 mg/dm(3)) than in the unplanted tank (similar to 35 mg/dm(3)). Final levels of total-nitrogen, nitrate and chemical oxygen demand were considerably lower in the reed and willow tank than in the unplanted tank.This experimental work was done with financial support of the
fellowship of Dr Andrzej Bia1owiec held at Cardiff University, School
of Biosciences, granted by Polish Ministry of Science and Higher
Education No. 219/MOB/2008/0. Data analysis was carried out with
financial support of EVAWET project e PTDC/AMB/73081/2006
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
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>
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
Effect of the sampling parameters in FOCV-MPPT circuits for fast-varying EH sources
No full text© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The fractional open circuit voltage (FOCV) method is extensively used in low-power energy harvesting (EH) sources to extract maximum power. For fast-varying EH sources a fast sampling rate is required. This work theoretically analyzes the influence of the sampling time and period on the harvested power of sinusoidal EH sources. In addition, the circuit limitations to achieve a fast sampling rate are presented and circuits to deal with them proposed and implemented. Furthermore, one of the circuits is based on a novel pseudo-FOCV method and achieves the fastest sampling rate. Experimental tests are performed with a 2 Hz, 1 V to 3 V sinusoidal source having an output resistance of 127 ¿, and the results are shown to agree with theoretical predictions. It is shown that 1) the harvested power increases with the sampling rate when the sampling time is negligible (sampling 15 times faster than the source frequency extracts around 99 % of the maximum), and 2) for fixed sampling times there is an optimum sampling rate where the harvested power is maximum. The first result is generic and valid for methods other than the FOCV. Tests were also performed with a small-scale wave energy converter placed in a linear shaker emulating a sea environment. Harvested power increases by 25 % with respect using a commercial FOCV unit with a low sampling rate.This work was supported by the project MELOA from the European Commission’s Horizon 2020 research and Innovation program under Grant Agreement No. 776280 and by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under project TEC2016-76991-P. The first author has a grant from the Secretariat of Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia on the FI program (ref. BDNS 362582).Peer ReviewedPostprint (author's final draft
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