Magentically-Induced Lattice Distortions and Ferroelectricity in Magnetoelectric GdMnO3

In this work we investigate the magnetic field dependence of Ag octahedra rotation (tilt) and B2g symmetric stretching modes frequency at different temperatures. Our field-dependent Raman investigation at 10K is interpreted by an ionic displacive nature of the magnetically induced ferroelectric phase transition. The frequency change of the Ag tilt is in agreement with the stabilization of the Mn-Gd spin arrangement, yielding the necessary conditions for the onset of ferroelectricity on the basis of the inverse Dzyaloshinskii-Moriya interaction. The role of the Jahn-Teller cooperative interaction is also evidenced by the change of the B2g mode frequency at the ferroelectric phase transition. This frequency change allows estimating the shift of the oxygen position at the ferroelectric phase transition and the corresponding spontaneous polarization of 480 {\mu}C/m2, which agrees with earlier reported values in single crystals. Our study also confirms the existence of a large magnetic hysteresis at the lowest temperatures, which is a manifestation of magnetrostiction.Comment: 5 pages, 3 figure

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

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

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

Accreditation under the International Standard ISO 15189: Experience of a Genetics Laboratory in DNA Sequencing

Introduction: Health care is to some extent influenced by the results of laboratory tests. In order to provide the best care for the patient, laboratories must seek to achieve high levels of quality and competence. International Standard ISO 15189 specifies these requirements and may be used by laboratories to perform accredited genetic tests of materials derived from the human body. Here we describe the procedures to establish Accreditation of DNA sequencing in our laboratory and the first Accreditation of its kind in Portugal. Methods: Our laboratory started to prepare to comply with ISO 15189 Accreditation requirements for DNA sequencing in 2010. Documents describing administrative and technical procedures of the sequencing workflow including sample registries, laboratory protocols, operation and maintenance of equipments, as well as preparation and use of reagents were produced. Regular examination of laboratory equipments by an external entity was implemented to confirm compliance with working requirements. Requisites for personnel training and demonstration of competence were also implemented. The laboratory participated regularly in the DNA sequencing scheme organized by the European Molecular Genetics Quality Network (EMQN). Results: The laboratory obtained formal recognition by Instituto Português de Acreditação (IPAC) in May 2014. A maximum genotyping score for DNA sequencing has been obtained in the external quality assessment scheme since 2010. Sequencing quality measured in terms of the quality read overlap metrics is currently of approximately 96% according to the EMQN scheme. The laboratory processes and analyzes an average of 28.750 samples per year. Discussion: Accreditation of a genetic test under ISO 15189 is a highly demanding and laborious task for a genetic laboratory. However, it is an important step in order to guarantee the highest quality and reproducibility of genetic test results

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

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

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

Utility of pace-matching mapping in the ablation of idiopathic ventricular tachyarrhythmias

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017.Introduction: The electroanatomical mapping of idiopathic ventricular tachyarrhythmias (iVT) - premature ventricular contractions (PVC) and idiopathic ventricular tachycardia (VT) - is dependent on the recording of spontaneous PVC or induction of the clinical VT during the procedure to obtain the iVT activation map. The presence of infrequent and non-inducible iVT may preclude ablation. Pace-matching (PM) mapping of the anatomical region on interest, using the PaSo™ algorithm, may allow to circumvent this limitation. Purpose: Determination of the utility of the PaSo™pace-matching mapping for iVT ablation Methods: A single-center retrospective study was made, with inclusion of consecutive patients undergoing iVT ablation between October 2013 and October 2016. It was collected electroanatomical data, including the highest correlation obtained by PM (PaSo™). Success of the procedure was assessed (defined as the elimination of spontaneous PVC during the electrophysiological study and non-inducible iVT at the end) and the ability of the PaSo™ pace-matching mapping to guide effective ablation was determined. Results: 29 patients were studied (62.1% women, mean age 52.8±14.7 years). 65.5% presented symptomatic frequent PVC and 34.5% VT. The most frequent anatomic origin was the right ventricular outflow tract (58.6%), followed by the left coronary cusp (20.7%), mitro-aortic continuity (13.8%) and papillary muscles (6.9%). The ablation was successful (PVC elimination during the procedure) in 75.9% of the cases. In 79.3% of the cases it was possible to obtain an activation map; in 20.7% (6 cases) it was only possible to obtain a pace-matching map, because ocurred suppression of PVC during the procedure, and success was achieved in 5 of these cases. There was no relationship between success and anatomical region of origin of the iVT. The mean value of the better pace-matching correlation was 94.45% ± 3.95%, being significantly higher when the zone of interest was located in the right ventricle (95.71±3.23 vs. 92.68±4.3, p=0.04). There was a positive and significant association between the PaSo™ correlation value and success (r=0.554; p=0.007). Significantly higher correlations were observed in successful ablations [95.9% vs 92%; p=0.006), and the PaSo™ correlation value was a good predictor of success (AUC: 0.874, 95% CI 0.74–1.0, p=0.003). The pace-matching threshold of 93.55% predicted ablation success with 86.4% sensitivity and 85.7% specificity. Conclusion: In patients with iVT, pace-matching mapping provides a suitable method for performing ablation procedure, and it is essential in patients where spontaneous suppression of PVC occurs during the procedure. The achievement of a pace-matching correlation>93.55% conveniently identifies the dysrhythmic focus, allowing increasing of ablation success.info:eu-repo/semantics/publishedVersio

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

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