63 research outputs found

    Non-contact determination of the viscoelastic properties of agar culture media by Brillouin spectroscopy

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    This study aimed to investigate the potential of Brillouin spectroscopy as a non-contact and real-time tool for measuring the viscoelastic properties of agar culture media and using them to determine the percentages of their different components. The Brillouin spectrum of media samples with varying concentrations of different components was successfully acquired. A custom-designed refractometer was employed for assessing the refractive index of the gels. The study shows that the Brillouin spectrum and viscoelastic properties of the media vary in dependence on the concentration of their different components in a predictable and controllable way and that the variation is different for each of the additives tested. This approach has the advantage of correlating to the component percentages, providing a non-contact method for evaluating the evolution of the culture medium in real-time, without disturbing the growth of cells or microorganisms. The results of this study have the potential to encourage the design of new tools and methods targeting the prediction, measuring, and control of agar plate behavior during cell culture. This could include measuring and maintaining optimal humidity conditions for maintaining suitable agar plates for cell culture or monitoring cell growth by measuring the consumption of each substance.This work was supported by CMEMS-UMinho Strategic Project UIDB/04436/2020 and UIDP/04436/2020 and project MPhotonBiopsy, PTDC/FIS-OTI/1259/2020. Bruno Esteves was supported by FCT, PhD grant 2021.07239.BD

    Vigilância da Gripe em Portugal no inverno 2013/2014

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    Introdução: O Programa Nacional de Vigilância da Gripe tem como objetivos: recolha, análise e divulgação da informação sobre a atividade gripal em Portugal. A vigilância clínica e laboratorial possibilita a determinação semanal das taxas de incidência de síndroma gripal (SG), identificação/ caracterização do vírus influenza, deteção de surtos, vírus emergentes com potencial pandémico e risco para a saúde pública. Foi analisada e descrita a atividade gripal em Portugal, na época de 2013/2014. Materiais e Métodos: Em 2013/2014, colaboraram: a Rede de Médicos-Sentinela (Rede MS), possibilitando o cálculo da taxa de incidência da síndroma gripal. Na componente laboratorial, colaboram Rede MS, Rede de Serviços-Urgência, médicos projeto-EuroEVA e Rede Portuguesa Laboratórios Diagnóstico Gripe com envio de amostras respiratórias para pesquisa/caraterização do vírus influenza. Resultados: Em 2013/2014, a atividade gripal foi moderada. O período epidémico ocorreu entre as semanas 1/2014 e 8/2014, valor máximo 80,7 casos SG / 100000 habitantes na semana 4/2014. A análise laboratorial a 869 exsudados-nasofaringe permitiu a identificação do vírus influenza em 467 (54%) casos de SG. Destes, 460 (98,5%) do tipo A: 279 (32%) do subtipo A(H1)pdm09 e 181 (21%) do subtipo AH3. Foram detetados 7 vírus influenza do tipo B. Discussão e Conclusão: Na época 2013/2014, a atividade gripal foi moderada com taxas de incidência semelhantes às 2012/2013. O período epidémico ocorreu mais cedo em relação a 2012/2013 e foi de menor duração. O vírus influenza do tipo A foi predominante com co-circulação dos dois subtipos: A(H1)pdm09 e A(H3). Os vírus detetados são genética e antigenicamente semelhantes às estirpes vacinais e sensíveis ao oseltamivir e zanamivir

    High-field magnetoresistance of La0.67Sr0.33MnO3 thin films deposited on LiNbO3 substrates

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    Colossal magnetoresistive manganites have been widely studied due to their potential use in sensor and device applications. In this work, La0.67Sr0.33MnO3 thin films were deposited by pulsed laser ablation on LiNbO3 substrates and magnetoresistance measurements were performed using pulsed magnetic fields up to 25 T. The corresponding magnetoconductance of the films was fitted in order to obtain the grain boundary (GB) contribution to the transport properties. The observed temperature dependence of the fitting parameters was indicative of antiferromagnetism across GB spins and reflected the progressive reduction of magnetic ordering with increasing temperature.This work was supported in part by Project No. FEDER/POCTI 155/94 from Fundação para a Ciência e Tecnologia (FCT). I.T. Gomes, A. Pereira and J. Barbosa gratefully acknowledge Ph.D. grants (SFRH/BD/36348/2007, SFRH/BD/22373/2005 and SFRH/BD/41913/2007, respectively) from FCT

    Infants prenatally exposed to SARS-CoV-2 show the absence of fidgety movements and are at higher risk for neurological disorders: A comparative study

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    Congenital viral infections are believed to damage the developing neonatal brain. However, whether neonates exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) show manifestations of such damage remains unclear. For neurodevelopment evaluation, general movement assessments have been shown to be effective in identifying early indicators of neurological dysfunction, including the absence of fidgety movements. This study compared the early motor repertoire by general movement assessment at three to five months of age in neonates who were or were not prenatally exposed to SARS-CoV-2 to determine whether infants prenatally exposed to SARS-CoV-2 are at risk of developing neurological disorders. Fifty-six infants, including 28 in the exposed group of mothers without vaccination who had no need for intensive care and likely had SARS-CoV-2 infection close to the time of pregnancy resolution and 28 infants in the nonexposed group, were videotaped to compare their detailed early motor repertoires, in which a motor optimality score-revised (MOS-R) was calculated using Prechtl’s method by using the chi-square or Mann–Whitney U tests. In the exposed group, 3 (11%) infants showed the absence of fidgety movements with a total MOS-R<14 points, and 3 (11%) other infants showed abnormal fidgety movements. Between groups, atypical body symmetry (p = 0.009) and MOS-R values were significantly lower (Z = -3.08, p = 0.002), with a large size effect (Cohen’s d = 0.97). The consequences of this new virus go beyond the health of the pregnant mother, and these consequences in some of the infants in the exposed group are likely not transitory because of the absence of fidgety movements between 3–5 months; thus, these babies are at increased risk of developing a serious neurological disorder

    Implantation of ICD and CRT-D in the elderly population : will it be a limiting factor?

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    Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017Introduction: Implantable cardioverter defibrillator (ICD) and cardiac resynchronization (CRT-D) implantation in elderly patients is effective in preventing sudden death, although limited by the natural shorter life expectancy. The different device brands present very variable survival estimates and it has been discussed the availability of less expensive, less longevity generators for the elderly population. Purpose: To determine if the expected survival rate in the elderly patient population (≥75 years) should influence the selection of the desired longevity of the devices. Methods: A retrospective single-center study of consecutive patients who underwent implantation of ICD or CRT-D after November 1995. The mean survival of patients undergoing 1st implant or generator replacement at an advanced age (≥75 years) was evaluated and compared to the effective longevity of the generators. Cumulative survival analyzes using the Kaplan Meier method were used. Results: A total of 1312 cardiac devices were implanted, of which 163 generators in elderly patients (53% CDI and 47% CRT-D). Of these, 77% corresponded to the 1st implant. The median survival after implantation of the elderly patients was 6.8 years, not differing according to the type of device (Log-rank P = NS). The median longevity of CDI generators was 6.9 years, in line with the expected survival of elderly patients. Conversely, the median CRT-D longevity was 5.8 years, lower than the average survival of the elderly. For this reason, 21% of these CRT-D carriers were subsequently subjected to generator replacement, due to battery exhaustion. Conclusion: The effective longevity of ICDs is in agreement with an expected survival of elderly patients, for which it will not make sense to provide generators of shortened longevity for this population. The effective longevity of the CRTs is lower than the survival expectancy of the treatments, so that, paradoxically, generators with increased longevity should be favored.info:eu-repo/semantics/publishedVersio

    Atrial fibrillation ablation : the added value of adenosine test in confirming pulmonary vein isolation

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    © The European Society of Cardiology 2018. All rights reserved.Introduction: Adenosine test has been increasingly used to confirm pulmonary vein isolation (PVI) in patients undergoing ablation of atrial fibrillation (AF). However, its impact on the success of ablation remains unknown. Purposes: To evaluate the results of the adenosine triphosphate (ATP) test in patients undergoing PVI and assess the success of ablation related to the use of this test (adenosine-guided PVI versus conventional PVI). Methods: Single-center prospective study of consecutive patients undergoing first AF ablation procedure, started at January 2013. After ablation, the persistence of PVI was tested with adenosine triphosphate administration (15–30mg by intravenous route). When adenosine triphosphate-induced pulmonary vein conduction (termed as reconduction) was observed, additional energy applications of radiofrequency were applied to obtain persistent isolation on retesting. Cardiac event recorder was performed at 7 days, 3, 6 and 12 months after ablation and annually from the 2nd year. The adenosine triphosphate-induced reconduction rate was evaluated depending on the pulmonary vein involved. The impact of adenosine test implementation in the success of the ablation at 365 days (recurrence of AF or supraventricular tachycardia) was determined by analysis of overall survival using Kaplan-Meier method. Results: Adenosine test was performed on 151 patients, with reconduction detected on at least one of the pulmonary veins in 11 patients (33.8%) and in 17.6% of the 641 pulmonary veins evaluated, with no statistically significant difference between the different veins. The overall success rate of AF ablation at 365 days was 72% and did not differ significantly between adenosine-guided PVI versus conventional PVI (74.3% versus 70.8%, P = NS), although the duration of follow-up had been shorter in the first group (median of 13.0 vs. 38.3 months; p<0.001). Conclusion: The adenosine-induced reconduction occurs in about one third of the patients. However, the additional adenosine-guided energy applications do not seem to increase the overall success of ablation. We found no significant reduction in the 1 year incidence of recurrent atrial tachyarrhythmias by ATP-guided PVI compared with conventional PVI.info:eu-repo/semantics/publishedVersio

    Molecularly imprinted polypyrrole based electrochemical sensor for selective determination of 4-ethylphenol

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    This work describes the development of an electrochemical sensor based on a molecularly imprinted polymer (MIP) for sensitive and selective determination of 4-ethylphenol in wine. The sensor has been built by means of the electrosynthesis of the MIP on a glassy carbon electrode surface using cyclic voltammetry. The electropolymerization has been performed in the presence of 4-ethylphenol and pyrrole as template molecule and functional monomer, respectively. The influence of the molar ratios of template molecules to functional pyrrole monomers and the time needed to remove the template have been optimized taking into account the differential pulse voltammetric response of 4-ethylphenol. Under the optimal experimental conditions the developed MIP/GCE sensor shows good capability of detection (0.2 μM, α = β = 0.05) and reproducibility (3.0%) in the concentration range from 0.2 to 34.8 μM. The influence of possible interfering species in the analytical response has been studied and the sensor has successfully been applied to the determination of 4-ethylphenol in different wine samples.Junta de Castilla y León (BU018G19

    A prospective survey in European Society of Cardiology member countries of atrial fibrillation management: baseline results of EURO bservational Research Programme Atrial Fibrillation (EORP-AF) Pilot General Registry

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    Aims: Given the advances in atrial fibrillation (AF) management and the availability of new European Society of Cardiology (ESC) guidelines, there is a need for the systematic collection of contemporary data regarding the management and treatment of AF in ESC member countries. Methods and results: We conducted a registry of consecutive in- and outpatients with AF presenting to cardiologists in nine participating ESC countries. All patients with an ECG-documented diagnosis of AF confirmed in the year prior to enrolment were eligible. We enroled a total of 3119 patients from February 2012 to March 2013, with full data on clinical subtype available for 3049 patients (40.4% female; mean age 68.8 years). Common comorbidities were hypertension, coronary disease, and heart failure. Lone AF was present in only 3.9% (122 patients). Asymptomatic AF was common, particularly among those with permanent AF. Amiodarone was the most common antiarrhythmic agent used (~20%), while beta-blockers and digoxin were the most used rate control drugs. Oral anticoagulants (OACs) were used in 80% overall, most often vitamin K antagonists (71.6%), with novel OACs being used in 8.4%. Other antithrombotics (mostly antiplatelet therapy, especially aspirin) were still used in one-third of the patients, and no antithrombotic treatment in only 4.8%. Oral anticoagulants were used in 56.4% of CHA 2DS2-VASc = 0, with 26.3% having no antithrombotic therapy. A high HAS-BLED score was not used to exclude OAC use, but there was a trend towards more aspirin use in the presence of a high HAS-BLED score. Conclusion: The EURObservational Research Programme Atrial Fibrillation (EORP-AF) Pilot Registry has provided systematic collection of contemporary data regarding the management and treatment of AF by cardiologists in ESC member countries. Oral anticoagulant use has increased, but novel OAC use was still low. Compliance with the treatment guidelines for patients with the lowest and higher stroke risk scores remains suboptimal. © The Author 2013
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