On inverse subsemigroups of the semigroup of orientation-preserving or orientation-reversing transformations

It is well-known [16] that the semigroup Tn of all total transformations of a given n-element set Xn is covered by its inverse subsemigroups. This note provides a short and direct proof, based on properties of digraphs of transformations, that every inverse subsemigroup of order-preserving transformations on a finite chain Xn is a semilattice of idempotents, and so the semigroup of all order-preserving transformations of Xn is not covered by its inverse subsemigroups. This result is used to show that the semigroup of all orientation-preserving transformations and the semigroup of all orientation-preserving or orientation-reversing transformations of the chain Xn are covered by their inverse subsemigroups precisely when n≤3

Power generation by unhealthy photovoltaic modules

Hotspots are one of many defects that can occur on degraded photovoltaic system, yielding a detrimental effect on the PV module production. Infrared thermography was used to detect and quantify the severity of hotspots. Temperature difference between overheated and healthy areas was assessed. Four PV modules were analysed, one of them presenting a hotspot. A model for both healthy and unhealthy PV modules was developed, based on the single diode solar cell model and considering, exclusively, data-sheet parameters. To validate the model, the outputs for these working conditions were compared with the real outputs of the studied PV modules, which were previously measured and stored. The relationship between the severity of a hotspot and its respective impact on the power generation of the PV module was studied and the consequent monetary loss can be assessed. Thermographic analysis was enhanced as an optimizing decision-aid tool for the operation of photovoltaic installations.publishersversionpublishe

Variability of sclerosis along the longitudinal hippocampal axis in epilepsy: A post mortem study

Detailed neuropathological studies of the extent of hippocampal sclerosis (HS) in epilepsy along the longitudinal axis of the hippocampus are lacking. Neuroimaging studies of patients with temporal lobe epilepsy support that sclerosis is not always localised. The extent of HS is of relevance to surgical planning and poor outcomes may relate to residual HS in the posterior remnant. In 10 post mortems from patients with long histories of drug refractory epilepsy and 3 controls we systematically sampled the left and right hippocampus at seven coronal anatomical levels along the body to the tail. We quantified neuronal densities in CA1 and CA4 subfields at each level using Cresyl Violet (CV), calretinin (CR), calbindin (CB) and Neuropeptide Y (NPY) immunohistochemistry. In the dentate gyrus we graded the extent of granule cell dispersion, patterns of CB expression, and synaptic reorganisation with CR and NPY at each level. We identified four patterns of HS based on patterns of pyramidal and interneuronal loss and dentate gyrus reorganisation between sides and levels as follows: (1) symmetrical HS with anterior–posterior (AP) gradient, (2) symmetrical HS without AP gradient, (3) asymmetrical HS with AP gradient and (4) asymmetrical cases without AP gradient. We confirmed in this series that HS can extend into the tail. The patterns of sclerosis (classical versus atypical or none) were consistent between all levels in less than a third of cases. In conclusion, this series highlights the variability of HS along the longitudinal axis. Further studies are required to identify factors that lead to focal versus diffuse HS

Assessing the Impact of Charcoal Production on Southern Angolan Miombo and Mopane Woodlands

About 80% of Angola’s forest surface is covered by Miombo and Mopane woodlands, which are explored for diverse activities such as fuelwood and food. This study aimed to assess the recovery dynamics of Miombo and Mopane woodlands after the selective cutting of tree species for charcoal production. For that, the structure and composition of plant communities in 37 plots, located in southwestern Angola, were characterized in fallows of different ages. Results showed that the diameter at breast height, basal area, biomass, and biovolume of trees all rose as the age of the fallow increased, and there were no significant differences in richness, diversity, or dominance of trees between adult–young classes or recent–older fallows. In Mopane, fallows took longer to regenerate, were more affected by environmental and anthropogenic factors, and also presented a higher species adaptation to disturbance. There were more sprouter and seeder trees in Miombo, and new kilns were more distant from roads and villages. Moreover, the selective removal of species deeply altered the community structure and dynamics, despite not directly affecting tree diversity. Thus, new management strategies are needed to ensure the survival of these woodlands such as expanding protected areas and increasing systematic research.info:eu-repo/semantics/publishedVersio

Adult-onset autoimmune diabetes: comparative analysis of classical and latent presentation

Introduction: Adult-onset autoimmune diabetes (AID) has two different phenotypes: classic type 1 diabetes mellitus (T1DM), with insulin requirement just after diagnosis, and latent autoimmune diabetes in adults (LADA). The purpose of this study is to characterize patients with AID followed on a tertiary centre, comparing classic T1DM and LADA. Methods: We collected data from patients with diabetes and positive islet autoantibodies, aged 30 years old and over at diagnosis. Patients who started insulin in the first 6 months were classified as T1DM and patients with no insulin requirements in the first 6 months were classified as LADA. Data regarding clinical presentation, autoantibodies, A1C and C-peptide at diagnosis, pharmacologic treatment and complications were analysed. Results: We included 92 patients, 46 with classic T1DM and 46 with LADA. The percentage of females was 50% in T1DM group and 52.1% in LADA group. The median age at diagnosis was 38 years (IQR–15) for T1DM and 42 years (IQR–15) for LADA (p = 0.057). The median time between diagnosis of diabetes and diagnosis of autoimmune aetiology was 0 months in T1DM group and 60 months in LADA group (p < 0.001). The mean BMI at diagnosis was 24.1 kg/m2 in T1DM group and 26.1 kg/m2 in LADA group (p = 0.042). In T1DM group, 67.4% of the patients had more than one positive autoantibody, comparing to 41.3% of LADA patients (p = 0.012). There was no statistical difference in what concerns to title of GAD autoantibodies, A1C and C-peptide at diagnosis of autoimmune aetiology. The presence of symptoms at diagnosis was associated with T1DM group (p < 0.001). The median daily insulin dose was 40 IU for T1DM (0.58 IU/kg) and 33.5 IU for LADA (0.57 IU/kg), with no statistical difference. LADA patients were more often under non-insulin antidiabetic drugs (p = 0.001). At 10 years follow up, 21.1% of T1DM patients and 63.3% of LADA patients had microvascular complications (p = 0.004). Diabetic nephropathy was present in 23.5% of T1DM patients and 53.3% of LADA patients (p = 0.047). At the last evaluation, 55.6% of T1DM and 82.6% of LADA patients had metabolic syndrome and this difference was independent of diabetes duration. Conclusion: Patients with classic T1DM presented more often with symptoms, lower BMI and higher number of autoantibodies, which may be related to a more aggressive autoimmune process. Patients with LADA developed more frequently microvascular complications for the same disease duration, namely diabetic nephropathy, and had more often metabolic syndrome

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

On inverse subsemigroups of the semigroup of orientation-preserving or orientation-reversing transformations

It is well-known [16] that the semigroup Tn of all total transformations of a given n-element set Xn is covered by its inverse subsemigroups. This note provides a short and direct proof, based on properties of digraphs of transformations, that every inverse subsemigroup of order-preserving transformations on a finite chain Xn is a semilattice of idempotents, and so the semigroup of all order-preserving transformations of Xn is not covered by its inverse subsemigroups. This result is used to show that the semigroup of all orientation-preserving transformations and the semigroup of all orientation-preserving or orientation-reversing transformations of the chain Xn are covered by their inverse subsemigroups precisely when n≤3

Quantiication of coumarins in wine spirit aged by different technologies using Chestnut wood

info:eu-repo/semantics/publishedVersio

Role of the RAD51 G172T polymorphism in the clinical outcome of cervical cancer patients under concomitant chemoradiotherapy

INTRODUCTION: Cervical cancer is one of the most common cancers diagnosed in women worldwide. Mammalian cells are constantly exposed to a wide variety of genotoxic agents from both endogenous and exogenous sources. The RAD51 protein is required for meiotic and mitotic recombination and plays a central role in homology-dependent recombinational repair of double-strand breaks (DSBs). Given the functional relevance of the DNA repair system on carcinogenesis, potential associations between genetic polymorphisms of DNA repair genes, cancer risk and response to therapy have been intensively evaluated. This is the first study evaluating the role of the RAD51 G172T genetic variants in cancer prognosis and clinical outcome of cervical cancer patients. MATERIAL AND METHODS: We analyzed RAD51 G172T polymorphism genotypes in cervical cancer patients who underwent a platinum-based chemotherapy in combination with radiotherapy. Genotyping was performed by Taqman™ Allelic Discrimination methodology. RESULTS AND DISCUSSION: Concerning the overall survival rates found using Kaplan-Meier method and Log Rank Test, we observed that the mean survival rates were statistically different according to the patients RAD51 genotypes. The group of patients carrying the T allele present a higher mean survival rate than the other patients (102.3months vs. 86.4months, P=0.020). Using the Cox regression analysis, we found an increased overall survival time for T-carrier patients, when compared with GG genotype, with tumor stage, age and presence of lymph nodes as covariates [hazard ratio (HR), 0.373; 95% CI, 0.181-0.770; P=0.008]. Among patients (n=193), RAD51 genotype frequency distributions were not under the influence of clinicopathologic characteristics, namely, treatment response (P=0.508), recurrence (P=0.150) and tumor stage (P=0.250). CONCLUSIONS: This is the first study evaluating the role of the RAD51 G172T genetic variants in cancer prognosis and clinical outcome of cervical cancer patients. Our results indicate an influence of the RAD51 genetic variants in overall survival of cervical cancer. Thereby, RAD51 G172T genotypes may provide additional prognostic information in cervical cancer patients who underwent cisplatin-based chemotherapy in combination with radiotherapy