Strong evidences for a nonextensive behavior of the rotation period in Open Clusters

Time-dependent nonextensivity in a stellar astrophysical scenario combines nonextensive entropic indices $q_{K}$ derived from the modified Kawaler's parametrization, and $q$, obtained from rotational velocity distribution. These $q$'s are related through a heuristic single relation given by $q\approx q_{0}(1-\Delta t/q_{K})$, where $t$ is the cluster age. In a nonextensive scenario, these indices are quantities that measure the degree of nonextensivity present in the system. Recent studies reveal that the index $q$ is correlated to the formation rate of high-energy tails present in the distribution of rotation velocity. On the other hand, the index $q_{K}$ is determined by the stellar rotation-age relationship. This depends on the magnetic field configuration through the expression $q_{K}=1+4aN/3$, where $a$ and $N$ denote the saturation level of the star magnetic field and its topology, respectively. In the present study, we show that the connection $q-q_{K}$ is also consistent with 548 rotation period data for single main-sequence stars in 11 Open Clusters aged less than 1 Gyr. The value of $q_{K}\sim$ 2.5 from our unsaturated model shows that the mean magnetic field topology of these stars is slightly more complex than a purely radial field. Our results also suggest that stellar rotational braking behavior affects the degree of anti-correlation between $q$ and cluster age $t$. Finally, we suggest that stellar magnetic braking can be scaled by the entropic index $q$.Comment: 6 pages and 2 figures, accepted to EPL on October 17, 201

A nonextensive insight to the stellar initial mass function

the present paper, we propose that the stellar initial mass distributions as known as IMF are best fitted by $q$-Weibulls that emerge within nonextensive statistical mechanics. As a result, we show that the Salpeter's slope of $\sim$2.35 is replaced when a $q$-Weibull distribution is used. Our results point out that the nonextensive entropic index $q$ represents a new approach for understanding the process of the star-forming and evolution of massive stars.Comment: 5 pages, 2 figures, Accepted to EP

Frequência de isolados clínicos de escherichia coli produtores de β-lactamases de largo espectro

Foi objectivo deste estudo determinar a frequência de isolados de E. coli produtores de β-lactamases de largo espectro (ESBLs) tanto em infecções nosocomiais como da comunidade, e avaliar a susceptibilidade aos antibióticos entre as estirpes produtoras e não produtoras de ESBLs. Dos 131 isolados investigados apenas 9 (6.8%) se enquadraram nos critérios definidos pelo CLSI para screening de ESBLs, e a sua presença foi confirmada por Etest ESBL. Estes isolados provieram maioritariamente de infecções da comunidade em doentes com idade avançada e história de hospitalização prévia. A maioria (66.6%) mostrou resistência simultânea aos β-lactâmicos estudados, às quinolonas e aos aminoglicosídeos.It was the purpose of this study to determine the frequency of extended­spectrum β­Lactamases (ESBLs) producing isolates in E. coli, from hospital acquired and community infections, and to evaluate antibiotic susceptibility between ESBL producing and non­producing strains. Of 131 isolates investigated only 9 (6.8%) fulfil CLSI screening criteria for ESBL, and its production was confirmed by ESBL Etest. This strains were mainly recovered form community infections in old aged patients, with an history of previous hospitalisation. The majority (66.6%) showed simultaneous resistance to the studied β­lactams, the quinolones and aminoglycosides

Screening of fungal metabolites in Brazil nuts using LC/MS/MS

The aim of this study was to evaluate quantitatively the occurrence of fungal metabolites in Brazil nuts. Nuts were collected from Agroforest production areas in Amazon basin region. A total of 235 mycotoxins were investigated/screened by a multi-mycotoxin method based on HPLC-MS/MS. The recovery was between 56 and 136%. Fifteen mycotoxins were detected and quantified, in at least one sample; namely, aflatoxins B1, B2, G1, and M1, kojic acid, sterigmatocystin, methyl-sterigmatocystin, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin. Aflatoxins were detected in just 1 sample (20%), but above its legal limit in Brazil and EU. Ochratoxin A and Fusarium toxins were not detected. Alternariol-methylether (from 0.75 to 3.2 g.kg-1) was detected in all five samples. This is the first study dealing with the detection of kojic acid, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin in Brazil nuts

Pyrazoles as potential modulators of inflammation through the inhibition of COX2 activity and human leukocytes' oxidative burst

The inflammatory process is a complex and tightly regulated cascade of events that involves the production of prostaglandins (PG) by the inducible isoform cyclooxygenase 2 (COX-2) and the production of reactive pro-oxidant species. When the production of these mediators becomes excessive, it can lead to chronic inflammation and associated diseases such as diabetes, rheumatoid arthritis, and cancer. Unfortunately, many existing anti-inflammatory agents are associated with unwanted side effects. Therefore, there is a critical need to discover new and effective compounds that can modulate the inflammatory cascade. In this study, an extensive panel of structurally related pyrazoles holding diverse structures and substitutions were tested in vitro against human COX-2, and ex vivo in human whole blood, through the measurement of prostaglandin E2 (PGE2) production. Their potential inhibitory effect against human leukocytes’ oxidative burst was also studied. The results showed that some of the tested compounds had a significant inhibitory effect on COX2 activity, and pyrazoles 4 and 11 (Figure 1) excelled as the most potent inhibitors, with IC50 < 25 µM. Nonetheless, among the tested compounds only 1 was able to inhibit both the COX-2 activity and the PGE2 production. The tested pyrazoles, namely pyrazole 4, also demonstrated a potential inhibitory effect (IC50 < 5 µM) against human leukocytes’ oxidative burst. These results represent a significant contribution for the design and development of new anti-inflammatory molecules.info:eu-repo/semantics/publishedVersio

Chemical Differentiation of Sugarcane Cultivars Based on Volatile Profile and Chemometric Analysis

Sugarcane (SC) is a perennial grass widely cultivated in tropical and subtropical regions. However, its cultivation in Europe is residual, where Madeira Island, Portugal, is the only region where SC continues to be extensively cultivated. For the first time, the volatile profiles of regional cultivars were established by solid-phase microextraction combined with gas chromatography− mass spectrometry. Different volatile profiles for each cultivar were recognized, identifying 260 volatile organic compounds belonging to 15 chemical classes, such as aldehydes, alcohols, ketones, hydrocarbons, esters, and terpenes. Chemometric analysis procedure, namely, one-way ANOVA with Tukey’s test, principal component analysis, partial least-square analysis, linear discriminant analysis, and hierarchical clustering analysis, allowed the differentiation between all regional cultivars. This study represents an important contribution for the maintenance of biodiversity and subsistence of the SC industry in Europe. Furthermore, it is also a valuable contribution to establish the typicality of traditional SC-based products, such as SC honey.info:eu-repo/semantics/publishedVersio

A Predictive Strategy Based on Volatile Profile and Chemometric Analysis for Traceability and Authenticity of Sugarcane Honey on the Global Market

Sugarcane honey (SCH) is a syrup produced on Madeira Island and recognized by its unique aroma, a complex attribute of quality with an important influence on the final consumer’s acceptance of the product, and determined by a complex mixture of a large number of volatile organic compounds (VOCs) generated during its traditional making process and storage. Therefore, the purpose of this study was to establish the volatile profile of genuine SCH produced by a regional certified producer for seven years and compare it with syrups from non-certified regional producers and with producers from different geographical regions (Spain, Egypt, Brazil and Australia), as a powerful strategy to define the volatomic fingerprint of SCH. Different volatile profiles were recognized for all samples, with 166 VOCs being identified belonging to different chemical classes, including furans, ketones, carboxylic acids, aldehydes and alcohols. Chemometric analysis allowed (i) the differentiation between all syrups, being more pronounced between SCH and other syrups; and (ii) the identification of 32 VOCs as potential markers for the traceability and authenticity of SCH on the global market.info:eu-repo/semantics/publishedVersio