Efficient channel estimation using TCH codes

In this paper, we consider the use of TCH codes to perform channel estimation in an OFDM system, using either data multiplexed pilots or superimposed pilots over the data. TCH codes possess several properties that allow us to use them efficiently in various applications which includes channel estimation, as we address in this paper. With this objective, several performance results were obtained through simulations which allowed the evaluation of the impact of different pilot power levels and modulations, as well as the comparison of TCH against other conventional pilots. In order to cope with the interference between pilots and data, an iterative receiver with interference suppression was employed for the superimposed pilots method.info:eu-repo/semantics/acceptedVersio

Robust joint synchronization and channel estimation approach for frequency-selective environments

Supporting spontaneous low-latency machine type communications requires fast synchronization and channel estimation at the receiver. The problems of synchronizing the received frame and estimating the channel coefficients are often addressed separately with the later one relying on accurate timing acquisition. While these conventional approaches can be adequate in flat fading environments, time dispersive channels can have a negative impact on both tasks and severely degrade the performance of the receiver. To circumvent this large degradation, in this paper we consider the use of a sparse based reconstruction approach for joint timing synchronization and channel estimation by formulating the problem in a form that is closely related to Compressive Sensing(CS) framework. Using modified versions of well-known sparse reconstruction techniques, which can take into account the additional signal structure in addition to sparsity, it is shown through numerical simulations that, even with short training sequences, excellent timing synchronization and channel estimation performance can be achieved, both in single user and multiuser scenarios.info:eu-repo/semantics/publishedVersio

Experiência de 6 Anos de Cirurgia Micrográfica de Mohs num Hospital Português

Introduction: Mohs micrographic surgery (MMS) is a surgical method of treating skin tumors that consists of histological control of the tumor margins using horizontal slices in thin, freshly frozen layers. This technique is a preferred indication for cutaneous facial tumors (basal and squamous cell carcinoma, among others) associated with higher risk of recurrence, recurrent tumors, tumors with undefined clinical margins, when there is perivascular and perineural involvement or with aggressive histological subtypes. Methods: The authors carried out a retrospective study of a 6-year period (from July 2012 until June 2018) at a Portuguese hospital – Egas Moniz hospital, to define the characteristics of patients undergoing Mohs micrographic surgery and to evaluate the advantages of this technique. The following factors were analyzed: age, gender, provenience, diagnosis, tumor location, number of stages of MMS, type of reconstruction of the surgical defect, follow-up and recurrences. Results: A total of 835 tumors were excised, 459 in male patients and 376 in female patients. The mean age at surgery was 71 years old (range 23- 95 years). Most of the lesions submitted to MMS were basal cell carcinomas (87%) and the most common location was the nasal pyramid (43%). In 44% of the cases, it was necessary to perform more than one micrographic stage. Half of the surgical defect closures were performed by graft or skin flap. Considering patients with a follow up equal or superior to 3 years, the recurrence rate was 4.9%. Discussion: The most frequent diagnosis was basal cell carcinoma, reflecting the importance of MMS in this type of skin malignancy, in both primary and persistent/recurrent lesions. Compared to other European surgery reviews, our recurrence rate is within normal range. This fact is particularly relevant, if we consider that our institution receives patients sent from hospitals and dermatologists from all over the country, specially selected for tumor aggressiveness or previous relapse. More than half of these patients were referred from other centers and consisted of persistent/recurrent basal cell carcinomas. The follow-up at recurrence for MMS was 27.9 months, supporting that a long follow-up of these patients is necessary. Conclusion: MMS allows lower rates of recurrence compared to simple surgical excision, so its practice should be encouraged in selected tumors. The surgical control of the margins instead of the “blind margins” is an advantage in saving healthy tissue and allows the complete excision of the tumor in the same surgical time.Introdução: A cirurgia micrográfica de Mohs é um método cirúrgico de tratamento dos tumores cutâneos que consiste no controlo histológico das margens do tumor usando cortes horizontais em camadas finas congeladas a fresco. Esta técnica é uma indicação preferencial para tumores cutâneos da face (carcinoma basocelular e espinocelular, entre outros) associados a maior risco de recidiva, tumores recidivados, com margens clínicas indefinidas, quando existe envolvimento perivascular e perineural ou com subtipos histológicos agressivos. Métodos: Os autores realizaram um estudo retrospetivo de um período de 6 anos (de julho 2012 até junho 2018) num hospital Português – Hospital de Egas Moniz, para definir as características dos doentes submetidos a cirurgia micrográfica de Mohs e avaliar as vantagens desta técnica. Foram analisados os fatores: idade, género, proveniência, diagnóstico, localização do tumor, número de estádios da cirurgia micrográfica de Mohs, tipo de reconstrução do defeito cirúrgico, seguimento e recidiva. Resultados: Foram operados 835 tumores no total, 459 em doentes do sexo masculino e 376 em doentes do sexo feminino. A média de idades foi de 71 anos (intervalo entre 23- 95 anos). A maioria dos tumores submetidos a cirurgia micrográfica de Mohs foram carcinomas basocelulares (87%) localizados na pirâmide nasal (43%). Em 44% dos casos, houve necessidade de realizar mais de um estadio micrográfico. Metade dos encerramentos do defeito cirúrgico foram realizados por enxerto ou retalho cutâneo. Em doentes com seguimento igual ou superior a 3 anos, a taxa de recidiva foi de 4,9%. Discussão: O diagnóstico mais frequente foi o de carcinoma basocelular, o que reflete a importância da cirurgia micrográfica de Mohs, neste tipo de neoplasia cutânea, quer em lesões primárias como persistente/recorrentes. Salientamos que comparativamente a outras revisões europeias de cirurgia de Mohs, a taxa de recidiva dos tumores se encontra dentro dos parâmetros normais. Este dado é particularmente relevante, se considerarmos que o nosso serviço recebe doentes enviados de hospitais e dermatologistas de todo o país, especialmente selecionados quanto à agressividade tumoral ou já recidivados. O intervalo médio de recorrência para MMS foi de 27,9 meses, o que demonstra a necessidade de um seguimento a longo prazo destes doentes. Conclusão: A cirurgia micrográfica de Mohs permite menores taxas de recidiva comparativamente á excisão cirúrgica simples pelo que a sua prática deve ser encorajada em tumores devidamente selecionados. O controlo cirúrgico das margens em vez das “margens cegas” é uma mais-valia tanto na poupança de tecido são como na garantia da excisão completa do tumor num mesmo tempo cirúrgico

Design of smart garments for sports and rehabilitation

Physical exercise has proved benefits for general health [1] and can reduce the number of sports injuries to one third [2]. However, an athlete that has been injured during sports practice may omit this out of fear of discrimination, and worsen the injury in the weight room, during strength training [5]. Monitoring physiological status of an athlete or rehabilitation patients during training may thus help the person to get an earlier intervention, preventing injuries from getting worse. With this in mind, we propose a set of compression garments – shirt and leggings – with textile sensors to continually monitor heart and muscle activity, breathing rate and temperature. This paper reports the design of the garments and production of the shirt, which comprised a 3-lead ECG system, sEMG (Surface Electromiography) electrodes and a breathing sensor. The ECG (Electrocardiography) system was tested and presented some good results, in particular for very even movements, but the system still needs to be improved, in order to get a better signal, when it comes to movements with a considerable amplitude.This work is financed by Project “Deus ex Machina”, NORTE-01-0145-FEDER-000026, funded by CCDRN, through Sistema de Apoio à Investigação Cientifica e Tecnológica (Projetos Estruturados I&D&I) of Programa Operacional Regional do Norte, from Portugal 2020 and by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136.info:eu-repo/semantics/publishedVersio

Vitamin B12 in Leber hereditary optic neuropathy mutation carriers: a prospective cohort study

Background Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder, frequently resulting in acute or subacute severe bilateral central vision loss. Vitamin B12 deficiency is also a known cause of optic neuropathy through mitochondrial dysfunction. Here we evaluated the prevalence and clinical significance of vitamin B12 deficiency in a large cohort of LHON patients and asymptomatic mutation carriers from a tertiary referral center. Methods From the Munich LHON prospective cohort study, participants included all LHON patients and asymptomatic LHON mutation carriers, who were recruited between February 2014 and March 2020 and consented to participate. Neurological, general, and ophthalmological examinations were regularly performed, as were laboratory tests. Vitamin B12 deficiency was diagnosed if serum vitamin B12 was below 201 pg/mL, or if 201–339 pg/mL plus low serum holotranscobalamin or elevated serum methylmalonic acid or elevated total plasma homocysteine. Results We analyzed 244 subjects, including 147 symptomatic LHON patients (74% males) and 97 asymptomatic mutation carriers (31% males). Median age at study baseline was 34 years (range 5–82 years). The prevalence of vitamin B12 deficiency was higher for LHON mutation carriers than for the general population in all age categories. This was statistically significant for the LHON mutation carriers under 65 years (21% vs. 5–7%, p = 0.002). While vitamin B12 deficiency prevalence was not statistically different between LHON patients and asymptomatic mutation carriers, its clinical correlates, e.g., macrocytosis and polyneuropathy, were more frequent in the subgroup of LHON patients. Excessive alcohol consumption was a significant predictor of vitamin B12 deficiency (p < 0.05). Conclusions The high prevalence of vitamin B12 deficiency in LHON mutation carriers, both asymptomatic mutation carriers and LHON patients, highlights the need for regular vitamin B12 screening in this population, in order to ensure early treatment, aiming for better outcomes. Our study is not conclusive regarding vitamin B12 deficiency as determinant for disease conversion in LHON, and further research is warranted to disentangle the role of vitamin B12 in the pathophysiology and prognosis of LHON

FTIR-ATR, FT-RAMAN and GC-FID assessment of discrimination of aged wine spirits under different conditions

info:eu-repo/semantics/publishedVersio

A new perspective on vescalagin, castalagin, and their degadation pathways in wine spirits ageing

info:eu-repo/semantics/publishedVersio

Volatile phenols in aged wine spirits: role, contents and impact of ageing systems

The volatile phenols (eugenol, guaiacol, 4-methylguaiacol, syringol, 4-methylsyringol and 4-allylsyringol) are odorant compounds that may exist in aged wine spirits resulting from their contact with wooden barrels during the ageing process. These compounds, which are originated from wood lignin’s, revealed an important sensory impact in aged wine spirits due to their low sensory thresholds and correlations with sensory attributes such as woody, toasted, smoke, which have a close relationship with the quality of these beverages. The wine spirits are traditionally aged in wooden barrels but the use of wood fragments, with or without micro-oxygenation, is a technological alternative that has been recently studied by our team with promising results. This work presents an overview of volatile phenols’ amounts in wine spirits aged in wooden barrels during different ageing times and using two kinds of wood (chestnut versus oak). These compounds were quantified by GC-FID, after a previous extraction and concentration steps, and their identification was assessed by GC-MS. It is also examined the results and the impact of alternative technologies on the amounts of such compounds. The ANOVA results showed a significant effect of the ageing system and the wood botanical species on the volatile phenols contentsinfo:eu-repo/semantics/publishedVersio

Smoking and alcohol, health-related quality of life and psychiatric comorbidities in Leber's Hereditary Optic Neuropathy mutation carriers: a prospective cohort study

BACKGROUND Leber's hereditary optic neuropathy (LHON) is a rare mitochondrial disorder, characterized by acute or subacute bilateral vision loss, frequently leading to significant chronic disability, mainly in young people. The causal LHON mutations of the mitochondrial DNA have incomplete penetrance, with the highest risk of disease manifestation for male mutation carriers in the second and third decades of life. Here we evaluated smoking, alcohol drinking habits, health-related quality of life (QOL) and psychiatric comorbidities in a cohort of LHON patients and asymptomatic mutation carriers from a tertiary referral centre. METHODS Cross-sectional analysis of the ongoing Munich LHON prospective cohort study. Participants included all LHON patients and asymptomatic LHON mutation carriers older than 16 years at baseline, who were recruited between February 2014 and June 2015 and consented to participate. General, neurological and ophthalmological investigations were performed, including validated questionnaires on smoking, alcohol drinking habits, depressive symptoms and health-related QOL. RESULTS Seventy-one participants were included, 34 LHON patients (82% male) and 37 asymptomatic mutation carriers (19% male). Median age at baseline was 36 years (range 18-75 years). For LHON patients, median age at visual loss onset was 27 years (9 to 72 years). Smoking is more frequent in LHON patients than asymptomatic LHON mutation carriers, and significantly more frequent in both groups than in the general population. Sixty percent of LHON patients, who smoked at disease onset, stopped or significantly reduced smoking after visual loss onset, yet 40% of LHON patients continued to smoke at study baseline. Excessive alcohol consumption is more frequent in male LHON patients than in LHON asymptomatic and more frequent than in the male general population. Further, female asymptomatic LHON mutation carriers are at risk for depression and worse mental QOL scores. CONCLUSIONS Given the high prevalence of smoking and excessive drinking in LHON mutation carriers, implementing effective measures to reduce these risk factors may have a significant impact in reducing LHON disease conversion risk. The underrecognized prevalence of mental health issues in this population of LHON mutation carriers highlights the need for awareness and more timely diagnosis, which may lead to improved outcomes

First Report of Dieback Caused by Neofusicoccum batangarum in Cashew in Guinea-Bissau

info:eu-repo/semantics/acceptedVersio