A theoretical study of the photochemistry of 1,3-cyclopentadiene and its cyano derivatives bound to a water dimer: Assessing reactivity of ionized clusters and possible photoproducts.

We theoretically investigate the photoionization scenarios of molecular complexes involving cyclopentadiene and cyanocyclopentadiene bound to water dimers. Using electronic structure calculations within density-functional theory (DFT) and time dependent DFT (TD-DFT), we explore the potential photochemical pathways following ionization, and determine the charge transfer excitations related to the possible subsequent reactions. Our findings suggest that the investigated photochemical pathways of the hydrated complexes take place in two well-defined ultraviolet regions: (i) 8.2-9.5 eV for the cyclic compounds and (ii) 11.2-11.4 eV for the bound water dimer. We quantify how H-bonding effects can influence the photoionization channels. Before forming possible photoproducts, we also examine the regiospecificity of OH addition to 1,3-cyclopentadiene and its cyano derivatives We analyze our results in light of photoionization studies of jet-cooled molecular complexes and possible implications in astrochemical environments.

Tradução e adaptação transcultural do questionário "Barriers to Being Active Quiz (BBAQ)'' para a língua portuguesa brasileira / Translation and cross-cultural adaptation of the questionnaire "Barriers to Being Active Quiz (BBAQ)" into Brazilian Portuguese language

Objetivou-se nesse estudo a tradução e validação transcultural do questionário Barriers to Being Active Quiz (BBAQ) para adolescentes brasileiros. Foram realizadas as seguintes etapas: (1) tradução do questionário original em inglês para o português; (2) resolução de divergências entre a versão 1 e a versão 2 e criação da versão síntese; (3) retrotradução para o inglês; (4) revisão e avaliação do comitê de especialistas, construção da versão pré-teste; e (5) pré-teste com a avaliação da compreensão por uma amostra (n = 30) da população-alvo. A versão final do BBAQ possui 21 questões. O questionário foi considerado de fácil entendimento por 70,0% dos adolescentes e os outros 30,0% dos adolescentes avaliaram o entendimento e a dificuldade de compreensão do questionário como moderado. Nenhum adolescente considerou o questionário como de difícil compreensão. O tempo médio para o preenchimento do BBAQ foi de 11 min (IC 95% = 9 ­ 12). O valor geral do Alfa de Cronbach com base nos itens padronizados do questionário foi de 0,86. O estudo apresentou evidências satisfatórias de validade e confiabilidade. Portanto, recomenda-se a utilização da adaptação transcultural do BBAQ para a avaliação de barreiras à prática de atividade física em adolescentes brasileiros.

The aim of the study was to perform the translation and cross-cultural validation of the Barriers to Being Active Quiz (BBAQ) questionnaire for Brazilian adolescents. The following steps were taken: (1) transla-tion of the original questionnaire from English to Portuguese; (2) resolution of discrepancies between version 1 and version 2 and creation of a synthesis version; (3) back-translation from Portuguese to English; (4) review and evaluation by an expert committee, construction of the pre-test version; and (5) pre-testing with comprehension assessment by a sample (n = 30) of the target population. The final version of the BBAQ com-prises 21 questions. The questionnaire was considered easy to understand by 70,0% of adolescents, while the remaining 30,0% rated the questionnaire's understanding and comprehension difficulty as moderate. None of the participants rated the questionnaire as difficult to understand. The average time for completing the BBAQ was 11 minutes (CI 95% = 9 ­ 12). The overall Cronbach's Alpha value, based on the standardized questionnaire items, was 0.86. The study presented satisfactory evidence of validity and reliability. There-fore, we recommend the use of the cross-cultural adaptation of the BBAQ for assessing barriers to physical activity among Brazilian adolescents.

Evaluation of the Effectiveness of Cutting Scalpel Blades After Use and leaning by Different Methods / Avaliação da Efetividade do Corte de Lâminas de Bisturi Após Uso e Limpeza Por Diferentes Métodos

When performing incisions during oral and maxillofacial surgical procedures, the surgeon requires a blade that ensures precise cuts which reduce unnecessary tissue injuries. After searching the literature, we realized that there is a lack of studies that assesses scalpel blades for dental use. Herein, this study aims to assess the cutting power of new scalpel blades after cleaning with different methods. Sixty sterile scalpel blades were divided into seven groups: I) new blade; II) the second insertion; III) blade cleaned with gauze; IV) blade cleaned with gauze and saline; V) blade cleaned with saline; VI) blade cleaned with cotton, and VII) blade cleaned with cotton and saline. A universal testing machine (Osvaldo Filizola, São Paulo, Brazil) was used for the insertion and measurement of the shear strength. The results revealed that cleaning the blade with gauze and saline was the method that had the greatest loss of the cutting capability. The reinsertion of the scalpel blade without any type of cleaning or the cleaning of the blade with cotton and saline were the methods that obtained the best result, which did not compromise the mechanical properties of the tested material. This study concludes that cleaning methods affect the cutting power of scalpel blade

Na execução dos procedimentos cirúrgicos bucais e maxilofaciais o operador, ao realizar incisões, necessita de uma lâmina que garanta um corte preciso, diminuindo lesões desnecessárias aos tecidos. Ao fazer uma busca na literatura, constatou-se carência de estudos que avaliassem lâminas de bisturi de uso odontológico. Diante desse cenário, o objetivo do presente estudo foi avaliar o poder de corte de lâminas de bisturi novas e após limpeza com diferentes métodos. Sessenta lâminas de bisturi estéreis foram divididas em sete grupos: I) lâmina nova; II) segunda inserção; III) lâmina limpa com gaze; IV) lâmina limpa com gaze e soro; V) lâmina limpa com soro; VI) lâmina limpa com algodão e VII) lâmina limpa com algodão e soro. Para inserção e aferição da resistência ao corte utilizou-se uma máquina de ensaio universal (Osvaldo Filizola, São Paulo, Brasil). Os resultados revelaram que a limpeza da lâmina com gaze e soro fisiológico foi o método que teve maior perda de corte. Já a reinserção da lâmina de bisturi sem quaisquer tipos de limpeza ou a limpeza da lâmina com algodão e soro foram as que obtiveram melhor resultado, não comprometendo as propriedades mecânicas do material testado. Conclui-se, com a realização desse estudo, que os métodos de limpeza afetam o poder de corte das lâminas de bisturi.

Allelic frequencies distribution and forensic parameters of 23 autosomal short tandem repeats in the population of the State of Pernambuco, Brazil.

Located in the Northeast Region, the Pernambuco State is one of the 27 federative units of Brazil. Here, we determined populational data for 23 short tandem repeat (STR) markers - CSF1PO, FGA, TH01, TPOX, vWA, D1S1656, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, PENTA D, PENTA E and SE33 - of the Pernambuco population. The sample consisted of 767 healthy, adult, unrelated individuals (437 males, 330 females) born and resident in the State of Pernambuco. STRs were amplified using three multiplex kits, according to the availability: PowerPlex® Fusion 6C System (Promega Corporation), PowerPlex® Fusion System (Promega Corporation) and GlobalFiler™ Express (Thermo Fisher Scientific). Allelic frequencies, forensic parameters and Hardy-Weinberg equilibrium determinations were estimated for all the 23 loci. No deviations from the Hardy-Weinberg equilibrium were observed for any of the markers, after Bonferroni correction. We observed that the most and less informative markers were SE33 and TPOX, respectively. The combined power of discrimination (CPD) was 0.99999999999999999999999999999, and the combined power of exclusion (CPE) was 0.99999999997. The cumulative typical paternity index was 37,919,301,869.3021. Interpopulation analyses (Nei's genetic distance) based on the expanded CODIS core loci was performed between the Pernambuco sample and other global populations. Pernambuco was the closest Brazilian population to African group and stayed distant from the Native American group. This work contributed to show that a panel of 23 autosomal STR loci is very informative, being able for forensic applications related in this population.

Suppression of a BAHD acyltransferase decreases p-coumaroyl on arabinoxylan and improves biomass digestibility in the model grass Setaria viridis.

Grass cell walls have hydroxycinnamic acids attached to arabinosyl residues of arabinoxylan (AX), and certain BAHD acyltransferases are involved in their addition. In this study, we characterized one of these BAHD genes in the cell wall of the model grass Setaria viridis. RNAi silenced lines of S. viridis (SvBAHD05) presented a decrease of up to 42% of ester-linked p-coumarate (pCA) and 50% of pCA-arabinofuranosyl, across three generations. Biomass from SvBAHD05 silenced plants exhibited up to 32% increase in biomass saccharification after acid pre-treatment, with no change in total lignin. Molecular dynamics simulations suggested that SvBAHD05 is a p-coumaroyl coenzyme A transferase (PAT) mainly involved in the addition of pCA to the arabinofuranosyl residues of AX in Setaria. Thus, our results provide evidence of p-coumaroylation of AX promoted by SvBAHD05 acyltransferase in the cell wall of the model grass S. viridis. Furthermore, SvBAHD05 is a promising biotechnological target to engineer crops for improved biomass digestibility for biofuels, biorefineries and animal feeding.

Esportes de aventura praticados na Barra da Tijuca e São Conrado, RJ: um levantamento das modalidades e formação do instrutor / Adventure sports practiced in Barra da Tijuca and São Conrado, RJ: a survey of the modalities and training of the instructor / Deportes de aventura practicados en Barra da Tijuca y São Conrado, RJ: un levantamiento de las modalidades y formación del instructor

Buscou-se identificar e analisar quais são os esportes de aventuras mais praticados na Barra da Tijuca e São Conrado, bem como a formação dos instrutores responsáveis pela condução dessa vertente esportiva nos referidos espaços naturais do Rio de Janeiro. A partir de um estudo de campo, com um grupo amostral de 176 instrutores foi possível afirmar que os esportes de aventura mais praticados são voo livre (81%), kitesurf (7%), surf (5%), trilha (5%), rapel (2%) e escalada (1%). Quanto à formação profissional, a investigação permite sinalizar que apenas 14% do total de instrutores possuíam formação em Educação Física. Portanto, o estudou concluiu que os esportes de aventura mais praticados nas regiões são os de mar e montanha, além de desvelar a necessidade de formação em Educação Física, bem como cursos de capacitação de instrutores de esportes de aventura, bem como para formação daqueles que têm interesse por atuação nesse campo.

We sought to identify and analyze the most practiced adventures sports in Barra da Tijuca and São Conrado, as well as the training of the instructors responsible for conducting this sport aspect in the aforementioned natural spaces of Rio de Janeiro. From a field study, with a sample group of 176 instructors, it was possible to state that the most practiced adventure sports are free flight (81%), kite surfing (7%), surfing (5%), , rappelling (2%) and climbing (1%). As far as professional training is concerned, research shows that only 14% of the total number of instructors had physical education. Therefore, the study concluded that the most practiced adventure sports in the regions are the sea and mountain, as well as unveiling the need for physical education training, as well as training courses for adventure sports instructors, as well as for training those who are interested in acting in this field.

Se buscó identificar y analizar cuáles son los deportes de aventuras más practicados en la Barra da Tijuca y São Conrado, así como la formación de los instructores responsables por la conducción de esa vertiente deportiva en los referidos espacios naturales de Río de Janeiro. A partir de un estudio de campo, con un grupo muestral de 176 instructores fue posible afirmar que los deportes de aventura más practicados son vuelo libre (81%), kitesurf (7%), surf (5%), trilha (5%), rapel (2%) y escalada (1%). En cuanto a la formación profesional, la investigación permite señalar que sólo el 14% del total de instructores poseían formación en Educación Física. Por lo tanto, el estudio concluyó que los deportes de aventura más practicados en las regiones son los de mar y montaña, además de desvelar la necesidad de formación en Educación Física, así como cursos de capacitación de instructores de deportes de aventura.

Correction to: Silencing of a BAHD acyltransferase in sugarcane increases biomass digestibility.

[This corrects the article DOI: 10.1186/s13068-019-1450-7.].

Silencing of a BAHD acyltransferase in sugarcane increases biomass digestibility.

BACKGROUND: Sugarcane (Saccharum spp.) covers vast areas of land (around 25 million ha worldwide), and its processing is already linked into infrastructure for producing bioethanol in many countries. This makes it an ideal candidate for improving composition of its residues (mostly cell walls), making them more suitable for cellulosic ethanol production. In this paper, we report an approach to improving saccharification of sugarcane straw by RNAi silencing of the recently discovered BAHD01 gene responsible for feruloylation of grass cell walls. RESULTS: We identified six BAHD genes in the sugarcane genome (SacBAHDs) and generated five lines with substantially decreased SacBAHD01 expression. To find optimal conditions for determining saccharification of sugarcane straw, we tried multiple combinations of solvent and temperature pretreatment conditions, devising a predictive model for finding their effects on glucose release. Under optimal conditions, demonstrated by Organosolv pretreatment using 30% ethanol for 240 min, transgenic lines showed increases in saccharification efficiency of up to 24%. The three lines with improved saccharification efficiency had lower cell-wall ferulate content but unchanged monosaccharide and lignin compositions. CONCLUSIONS: The silencing of SacBAHD01 gene and subsequent decrease of cell-wall ferulate contents indicate a promising novel biotechnological approach for improving the suitability of sugarcane residues for cellulosic ethanol production. In addition, the Organosolv pretreatment of the genetically modified biomass and the optimal conditions for the enzymatic hydrolysis presented here might be incorporated in the sugarcane industry for bioethanol production.

Identification and characterization of core abscisic acid (ABA) signaling components and their gene expression profile in response to abiotic stresses in Setaria viridis.

Abscisic acid (ABA) is an essential phytohormone that regulates growth, development and adaptation of plants to environmental stresses. In Arabidopsis and other higher plants, ABA signal transduction involves three core components namely PYR/PYL/RCAR ABA receptors (PYLs), type 2C protein phosphatases (PP2Cs) and class III SNF-1-related protein kinase 2 (SnRK2s). In the present study, we reported the identification and characterization of the core ABA signaling components in Setaria viridis, an emerging model plant for cereals and feedstock crops presenting C4 metabolism, leading to the identification of eight PYL (SvPYL1 to 8), twelve PP2C (SvPP2C1 to 12) and eleven SnRK2 (SvSnRK2.1 through SvSnRK2.11) genes. In order to study the expression profiles of these genes, two different S. viridis accessions (A10.1 and Ast-1) were submitted to drought, salinity and cold stresses, in addition to application of exogenous ABA. Differential gene expression profiles were observed in each treatment and plant genotype, demonstrating variations of ABA stress responses within the same species. These differential responses to stresses were also assessed by physiological measurements such as photosynthesis, stomatal conductance and transpiration rate. This study allows a detailed analysis of gene expression of the core ABA signaling components in Setaria viridis submitted to different treatments and provides suitable targets for genetic engineering of C4 plants aiming tolerance to abiotic stresses.

Quantitative analysis of phenolic metabolites in Copaifera langsdorffii leaves from plants of different geographic origins cultivated under the same environmental conditions.

INTRODUCTION: Galloylquinic acid derivatives and flavonoids are the main phenolic metabolites found in Copaifera langsdorffii leaves (Leguminosae, Detarioideae), a medicinal plant with potential therapeutic application in the treatment of kidney stones. The factors that affect metabolite production in this plant species are not well understood but may include environmental and genetic factors. OBJECTIVE: To quantify the variation in metabolite production over a 12-month period for 10 groups of C. langsdorffii cultivated under the same environmental conditions. METHODS: Copaifera langsdorffii seeds were collected from 10 different regions in southeast, Brazil and grown in the same field. HPLC-UV was used to quantify nine galloylquinic acid derivatives and two flavonoids in leaf samples from mature trees. Climate data for humidity, radiation, precipitation and temperature were provided by the National Institute of Meteorology, Brazil. Multivariate analyses were performed to correlate chemical and environmental variables. RESULTS: The overall effect of environmental factors on the production of phenolic metabolites was uniform among C. langsdorffii groups. Chemical variation between groups was present, but small, and probably due to differences in their genetics and physiology. Seasonal changes influenced the production of the major phenolic metabolites, with increases in temperature and radiation levels favouring metabolite production. CONCLUSION: When C. langsdorffii trees are cultivated in the same environment, the production of the major secondary metabolites found in their leaves is very similar quantitatively, varying based on geographic location of original population and seasonal changes. This favours the standardisation of plant raw material for the production of a phytomedicine.

Influence of abiotic environmental factors on the main constituents of the volatile oils of Tithonia diversifolia

ABSTRACT Tithonia diversifolia (Hemsl.) A. Gray, Asteraceae, commonly known as Mexican sunflower, is a wide distributed invasive species encountered around the world. We proposed herein to establish the relationship between different abiotic environmental factors and the variation in the production of volatile compounds in T. diversifolia, during a period of one year. Samples of leaf and inflorescence volatile oils obtained from individuals located at two different regions of Brazil were analyzed by GC-MS and the data were submitted to chemometric analysis. Based on the main constituents, the analysis allowed us to classify the volatile oils into two chemotypes, according to their geographical origin. The influence of soil nutrients, mainly Ca and P, was also observed in the composition of the volatile oils. Climate also seems to affect the constituents of the volatile oils, mainly the contents of leaf sesquiterpenes of individuals growing in areas with higher average temperatures and solar radiation levels. We can therefore highlight that the appropriate multivariate statistical analysis allowed us to propose for the first time the existence of chemotypes for the volatile oils of T. diversifolia, as well as reporting the main abiotic environmental factors related to the accumulation of the discriminant compounds in these oils.

Suppression of a single BAHD gene in Setaria viridis causes large, stable decreases in cell wall feruloylation and increases biomass digestibility.

Feruloylation of arabinoxylan (AX) in grass cell walls is a key determinant of recalcitrance to enzyme attack, making it a target for improvement of grass crops, and of interest in grass evolution. Definitive evidence on the genes responsible is lacking so we studied a candidate gene that we identified within the BAHD acyl-CoA transferase family. We used RNA interference (RNAi) silencing of orthologs in the model grasses Setaria viridis (SvBAHD01) and Brachypodium distachyon (BdBAHD01) and determined effects on AX feruloylation. Silencing of SvBAHD01 in Setaria resulted in a c. 60% decrease in AX feruloylation in stems consistently across four generations. Silencing of BdBAHD01 in Brachypodium stems decreased feruloylation much less, possibly due to higher expression of functionally redundant genes. Setaria SvBAHD01 RNAi plants showed: no decrease in total lignin, approximately doubled arabinose acylated by p-coumarate, changes in two-dimensional NMR spectra of unfractionated cell walls consistent with biochemical estimates, no effect on total biomass production and an increase in biomass saccharification efficiency of 40-60%. We provide the first strong evidence for a key role of the BAHD01 gene in AX feruloylation and demonstrate that it is a promising target for improvement of grass crops for biofuel, biorefining and animal nutrition applications.

Effect of the environment on the secondary metabolic profile of Tithonia diversifolia: a model for environmental metabolomics of plants.

Tithonia diversifolia is an invasive weed commonly found in tropical ecosystems. In this work, we investigate the influence of different abiotic environmental factors on the plant's metabolite profile by multivariate statistical analyses of spectral data deduced by UHPLC-DAD-ESI-HRMS and NMR methods. Different plant part samples of T. diversifolia which included leaves, stems, roots, and inflorescences were collected from two Brazilian states throughout a 24-month period, along with the corresponding monthly environmental data. A metabolomic approach employing concatenated LC-MS and NMR data was utilised for the first time to study the relationships between environment and plant metabolism. A seasonal pattern was observed for the occurrence of metabolites that included sugars, sesquiterpenes lactones and phenolics in the leaf and stem parts, which can be correlated to the amount of rainfall and changes in temperature. The distribution of the metabolites in the inflorescence and root parts were mainly affected by variation of some soil nutrients such as Ca, Mg, P, K and Cu. We highlight the environment-metabolism relationship for T. diversifolia and the combined analytical approach to obtain reliable data that contributed to a holistic understanding of the influence of abiotic environmental factors on the production of metabolites in various plant parts.

Brasiliensic and isobrasiliensic acids: isolation from Calophyllum brasiliense Cambess. and anti-Helicobacter pylori activity.

The occurrence of chromanone derivatives has been noticed as a distinctive feature of the genus Calophyllum (Calophyllaceae). Previous studies have demonstrated that the extract of the stem bark of Calophyllum brasiliense and its chromanone-rich fractions show anti-ulcer activity in murine gastric ulcer models. In this work, brasiliensic and isobrasiliensic acids, the two main compounds of the n-hexane extract of the stem bark extract of C. brasiliense, were isolated by flash chromatography using silica gel impregnated with silver nitrate and their structures were elucidated by NMR techniques and mass spectrometry. 13C NMR data is available for the first time for both compounds. Brasiliensic and isobrasiliensic acids showed good in vitro bacteriostatic activity against Helicobacter pylori, and are responsible, at least in part, for the bacteriostatic anti-H. pylori activity of the n-hexane extract of the stem bark of C. brasiliense.

The Use of Cannabis as a Predictor of Early Onset of Bipolar Disorder and Suicide Attempts.

Introduction. Bipolar disorder (BD) implies risk of suicide. The age at onset (AAO) of BD carries prognostic significance. Substance abuse may precede the onset of BD and cannabis is the most common illicit drug used. The main goal of this study is to review the association of cannabis use as a risk factor for early onset of BD and for suicide attempts. Materials and Methods. PubMed database was searched for articles using key words "bipolar disorder," "suicide attempts," "cannabis," "marijuana," "early age at onset," and "early onset." Results. The following percentages in bipolar patients were found: suicide attempts 3.6-42%; suicide attempts and substance use 5-60%; suicide attempts and cannabis use 15-42%. An early AAO was associated with cannabis misuse. The mean age of the first manic episode in individuals with and without BD and cannabis use disorder (CUD) was 19.5 and 25.1 years, respectively. The first depressive episode was at 18.5 and 24.4 years, respectively. Individuals misusing cannabis showed increased risk of suicide. Discussion. Cannabis use is associated with increased risk of suicide attempts and with early AAO. However, the effect of cannabis at the AAO and suicide attempts is not clear.

Uso de substâncias psicoativas por estudantes rurais: distribuição por sexo e idade / Consumo de sustancias psicoactivas en una escuela rural: distribución por sexo y edad / Use of psychoactive substances by students of a rural school: distribution by sex and age

Objetivo: analisar o uso na vida de álcool, tabaco e outras drogas e sua distribuição por sexo e idade em estudantes do fundamental II e médio, de uma escola pública e rural. Método: estudo quantitativo, descritivo e transversal, realizado de agosto a novembro de 2011 com 146 estudantes de Petrolina e analisado pelo programa Microsoft Excel 2007. Como critérios de elegibilidade elegeu-se ser maior de 18 anos e assinar o Termo de Consentimento Livre e Esclarecido ou, se menor, obter a assinatura do responsável. Resultados: verificou-se maior uso na vida por álcool, predominando mulheres de 16 a 18 anos; 16,44% usaram cigarro, sem distinção do sexo; e 3,42% usaram drogas ilícitas, prevalecendo os homens. Conclusões: estratégias educacionais, através da escola, família ou governo, são necessárias na promoção de diálogos com os alunos, reduzindo o uso de álcool, tabaco e outras drogas entre estudantes.

Objective: to analyze the lifetime use of alcohol, tobacco and other drugs, and their distribution by sex and age of students of elementary and high school, in a rural public school. Method: quantitative, descriptive and cross-sectional study, conducted from August to November of 2011 with 146 students in Petrolina and analyzed by Microsoft Excel 2007. As for the criteria of eligibility, elligible students had to be over 18 and sign the Informed Consent or, if underage, obtain the parents’ signature. Results: there was greater lifetime use of alcohol, predominantly among women of 16-18 years old; 16.44% used cigarettes, without distinction of sex; and 3.42% used illicit drugs, prevailing men. Conclusions: educational strategies, through school, family or government, are necessary to promote dialogues with students, reducing the use of alcohol, tobacco and other drugs among students.

Objetivo: analizar el consumo de alcohol, tabaco y otras drogas y su distribución por sexo y edad entre estudiantes de una escuela pública rural de primaria y secundaria. Método: estudio cuantitativo, descriptivo y transversal, realizado entre agosto y noviembre de 2011 con 146 estudiantes en Petrolina (PE, Brasil) y analizados com Microsoft Excel 2007. Como criterios de elegibilidad se exigió ser mayor de 18 años yFirmar un consentimiento informado o, para menores de edad, obtener la firma del responsable. Resultados: se verificó mayor consumo de alcohol, predominantemente entre mujeres de 16-18 años; 16,44% consumen cigarrillos, sin distinción de sexo; y 3,42% consumen drogas ilícitas, prevaleciendo los hombres. Conclusiones: estratégias educativas, a través de la escuela, la familia o el gobierno, son necesarios en la promoción de diálogos con los estudiantes, para reducir el consumo de alcohol, tabaco y otras drogas entre los estudiantes.

Environmental factors affecting the concentration of phenolic compounds in Myrcia tomentosa leaves

Myrcia tomentosa (Aubl.) DC., Myrtaceae, found in Central Brazilian Cerrado and popularly known as "goiaba-brava", belongs to the Myrcia genus, which has several species with medicinal properties such as: hypoglycemic, diuretic, hypotensive, antidiarrheal, antimicrobial and antitumor. The present study aimed to analyzed the environmental influence on concentrations of phenolic metabolites in M. tomentosa leaves. Compounds assayed in the leaves were: total phenols, tannins by protein precipitation, hydrolysable tannins and total flavonoids and mineral nutrients, while soil fertility was also analyzed, all over during one year. The results were submitted to Pearson Correlation Analysis and stepwise Multiple Regression Analysis to investigate the relationship between phenolics and environment data. Analysis of variance and Cluster Analysis allowed indicated a high variability in samples from different sites. The results obtained suggests that content of phenolics from M. tomentosa leaves are influenced by environmental factors, particularly some foliar nutrients (N1, Ca1 and Mn1), soil nutrients (Ca s and Ks) and Rainfall.

Essential oils in aerial parts of Myrcia tomentosa: composition and variability

Species in the Myrtaceae family are used in folk medicine to treat gastrointestinal disorders, infectious diseases and hemorrhagic conditions and are known for their essential oil contents. Gas chromatography coupled with mass spectrometry (GC-MS) was used to characterize the chemical composition of essential oils of the leaves, stem bark and flowers of Myrcia tomentosa (Aubl.) DC., as well as to assess the chemical variability in the constituents of the essential oils of the leaf. Soil and foliar analyses were also performed to determine the mineral compositions. Principal component analysis (PCA) was used to examine the interrelationships between the obtained data. The most abundant component in the essential oils of the flowers was (2E,6E)-methyl farnesoate, whereas hexadecanoic acid was the most abundant essential oil component in the stem bark. The leaf essential oils showed seasonal variation in their chemical composition, with bicyclogermacrene and (2E,6E)-methyl farnesoate as the major chemical components. Forty-four constituents were identified, and only nine compounds were found in all of the samples. Sesquiterpenes were mainly produced in the flowers and leaves. The PCA showed a positive correlation between the oxygenated sesquiterpenes and the foliar nutrients Cu and P. Significant statistical correlations were verified between the climatic data, foliar nutrients and essential oil compositions.

Perialveolar bacterial microbiota and bacteraemia after dental alveolitis in adult rats that had been subjected to neonatal malnutrition.

The aim of the present study was to analyse the bacteriological factors during the process of dental alveolitis, relating it to a higher incidence of bacteraemia in adult rats subjected to neonatal malnutrition. We used forty male Wistar rats, suckled by mothers fed a diet during lactation containing 17 % protein in the nourished group (N) or 8 % protein in the undernourished group (UN). After weaning, the animals were given the Labina standard diet. After 90 d, these animals underwent upper right incisor extraction and induction of alveolitis. The oral microbiota was obtained using a swab and blood culture through venous blood. These procedures were performed before the extraction, 5 min after extraction, on the 21st day after alveolitis for groups N-21 and UN-21 and on the 28th day after alveolitis for groups N-28 and UN-28. Data were expressed as means and standard deviations for parametric data, and as medians and interquartile intervals for non-parametric data. Statistical significance was considered by assuming a critical level of 5 %. Before and after extraction, lower bacterial growth was observed per colony-forming unit (CFU) in the perialveolar region of the upper right incisors of undernourished animals, while the opposite was true after alveolitis, when a larger number of CFU was observed in these animals. The percentage of positive blood cultures obtained after alveolitis was greater in the undernourished animals. The present study thus demonstrated the influence of neonatal malnutrition in the perialveolar microbiota and in the development of bacteraemia after dental alveolitis.

Influence of environmental factors on the concentration of phenolic compounds in leaves of Lafoensia pacari

Lafoensia pacari A. St.-Hil., Lythraceae, a plant from the Cerrado known as pacari or dedaleiro, is widely used as an antipyretic, wound healing, anti-inflammatory, antidiarrheal and in the treatment of gastritis and cancer. Notable among the metabolite groups identified in leaves of L. pacari are the polyphenols, such as tannins and flavonoids, related to the pharmacological activities of pacari. Studies on the influence of environmental factors over production of major groups of secondary metabolites in pacari are important because they contribute data for its cultivation and harvest, and establish quantitative parameters of secondary metabolites in the plant drug. The objective of this study was to evaluate the influence of environmental factors on concentrations of phenolic metabolites in the leaves of L. pacari. Compounds quantified in the leaves were: total phenols, tannins by protein precipitation, hydrolysable tannins, total flavonoids, ellagic acid and mineral nutrients, while soil fertility was also analyzed, all over a period of one year. The data were analyzed using multivariate analysis, and the results suggest that metabolite concentrations in the leaves of this plant are influenced by seasonal factors, in particular the temperature and foliar micronutrients (Cu, Fe, Mn, Zn).