A Preparação de Perfume como Proposta de Experimentação para o Ensino de Química no Ensino Médio

As atividades experimentais estruturadas em temas geradores, como a preparação de um perfume, permitem aos alunos compreender conteúdos químicos, centrados no contexto sociocultural do estudante. Neste sentido, o trabalho aborda a química existente nos perfumes e em seu processo fabril, a partir do princípio da extração de um óleo essencial. O experimento foi realizado com alunos da 3ª série do Ensino Médio. Funções orgânicas, conceito de acidez, basicidade, indicadores ácido/base, polaridade de moléculas, técnicas de maceração e destilação são conceitos químicos que foram abordados na atividade. O método envolveu a introdução sobre os perfumes no contexto sócio-histórico; a extração de um óleo essencial; a fabricação de perfumes; e o teste do pH dos perfumes. Foram utilizados materiais de fácil obtenção, o que permite a realização dos experimentos por qualquer instituição escolar. A atividade possibilitou aos alunos compreenderem melhor, principalmente, os conteúdos de solubilidade, volatilidade e interações intermoleculares

A novel VIVO–pyrimidinone complex: synthesis, solution speciation and human serum protein binding

The pyrimidinones mhcpe, 2-methyl-3H-5-hydroxy-6-carboxy-4-pyrimidinone ethyl ester (mhcpe, 1), 2,3- dimethyl-5-benzyloxy-6-carboxy-4-pyrimidinone ethyl ester (dbcpe, 2) and N-methyl-2,3-dimethyl-5- hydroxy-6-carboxyamido-4-pyrimidinone (N-MeHOPY, 3), are synthesized and their structures determined by single crystal X-ray diffraction. The acid–base properties of 1 are studied by potentiometric and spectrophotometric methods, the pKa values being 1.14 and 6.35. DFT calculations were carried out to determine the most stable structure for each of the H2L+, HL and L− forms (HL = mhcpe) and assign the groups involved in the protonation–deprotonation processes. The mhcpe− ligand forms stable complexes with VIVO2+ in the pH range 2 to 10, and potentiometry, EPR and UV-Vis techniques are used to identify and characterize the VIVO–mhcpe species formed. The results are consistent with the formation of VIVO, (VIVO)L, (VIVO)L2, (VIVO)2L2H−2, (VIVO)L2H−1, (VIVO)2L2H−3, (VIVO)LH−2 species and VIVO-hydrolysis products. Calculations indicate that the global binding ability of mhcpe towards VIVO2+ is similar to that of maltol (Hmaltol = 3-hydroxy-2-methyl-4H-pyran-4-one) and lower than that of 1,2-dimethyl-3-hydroxy-4- pyridinone (Hdhp). The interaction of VIVO-complexes with human plasma proteins (transferrin and albumin) is studied by circular dichroism (CD), EPR and 51V NMR spectroscopy. VIVO–mhcpe–protein ternary complexes are formed in both cases. The binding of VIVO2+ to transferrin (hTF) in the presence of mhcpe involves mainly (VIVO)1(hTF)(mhcpe)1, (VIVO)2(hTF)(mhcpe)1 and (VIVO)2(hTF)(mhcpe)2 species, bound at the FeIII binding sites, and the corresponding conditional formation constants are determined. Under the conditions expected to prevail in human blood serum, CD data indicate that the VIVO–mhcpe complexes mainly bind to hTF; the formation of VIVO–hTF–mhcpe complexes occurs in the presence of FeIII as well, distinct EPR signals being clearly obtained for FeIII–hTF and to VIVO–hTF–mhcpe species. Thus this study indicates that transferrin plays the major role in the transport of VIVO–mhcpe complexes under blood plasma conditions in the form of ternary VIV–ligand–protein complexes.The authors are grateful to the Fundo Europeu para o Desenvolvimento Regional, Fundação para a Ciência e Tecnologia (FCT), the POCI 2010 Programme, the Portuguese NMR Network (IST-UTL Center), PEst-OE/QUI/UI0100/2011, University of A Coruña and the Spanish-Portuguese Bilateral Programme (Acção Integrada E-56/05, Acción integrada HP2004- 0074)

Comparison of Two Methods to Quantify 2,6-Dichlorophenol from Tick Amblyomma cajennense by GC/MS-SIM

Amblyomma cajennense (Acari: Ixodidae) é um carrapato de grande importância sócio-econômica no subcontinente Sul-Americano. Apesar disso, pouco se conhece acerca de sua ecologia química, cuja informação é crucial para o seu controle. Nesse estudo, 2,6-diclorofenol (2,6-DCP), o feromônio sexual de A. cajennense foi quantificado por cromatografia gasosa acoplada a espectrometria de massas no modo de análise por monitoramento seletivo de íons (CG/EM-MSI) a partir de fêmeas alimentadas em coelhos durante 6 dias. O extrato do feromônio sexual foi obtido pela exposição ao ultrassom de fêmeas virgens em hexano em duas amostras independentes. Nenhum pré-tratamento da amostra foi necessário. Os métodos de adição padrão (SA) e de curva de calibração com 5-bromo-4-hidróxi-3-metóxibenzaldeído (5-BrV) como padrão interno (IS) foram utilizados para a quantificação. O conteúdo de 2,6-DCP não apresentou diferença significativa entre os extratos e/ou métodos utilizados. Os resultados mostraram que as faixas de concentração de 2,6-DCP por fêmea foram de 2,03-2,27 ng mL -1 e de 2,06-2,24 ng mL -1 para os métodos SA e IS, respectivamente. Os métodos mostraram ser específicos, sensíveis e fidedignos na determinação de 2,6-DCP em carrapatos. Amblyomma cajennense (Acari: Ixodidae) is a tick of socioeconomic importance in the South American sub-continent. Nevertheless, little is known pertaining to its chemical ecology, information deemed crucial to its management. In this study, the tick sex pheromone 2,6-dichlorophenol (2,6-DCP) was quantified from A. cajennense fed on rabbits for 6 days by use of gas chromatography-mass spectrometry in the selected ion monitoring mode (GC/MS-SIM). The sex pheromone extract was obtained by the exposure of attractive females to hexane and ultrasound probe in two independent samples. Clean-up was not necessary. Standard addition method (SA) and calibration curve with 5-bromine-4-hydroxy-3-methoxybenzaldehyde (5-BrV) as an internal standard (IS) were employed in the quantification. 2,6-DCP contents did not show significant differences between extracts and/or methods. Results showed that the concentration range of sex pheromone per female were 2.03-2.27 ng mL -1 and 2.06-2.24 ng mL -1 for SA and IS methods, respectively. The methods provide a specific, sensitive and reliable technique for determining 2,6-DCP levels in ticks

Effects of Enteral Fluid Therapy in Continuous Flow Administered by Nasogastric Tube in Buffalo Calves

To investigate the employment of enteral fluid therapy in continuous flow administered by a nasogastric tube in buffalo calves; toassesstheeffectsof a hypotonic and an isotonic electrolyte solutionon: vital functions, blood count and serum andurinary biochemistry profile of buffalo calves. Seven buffalo calves, clinically healthy, were submitted to two treatments. The solutions were administered in continuous flow through a nasogastric tube at a dose of 15 mL/kg/hr for 12 hours. The serum biochemistry profile showed an increase in chloride concentration, decrease in serumurea and osmolarity. In urine, anincrease in sodium and chloride concentrations and a decrease in calcium, creatinine and urea were observed. Enteral fluid therapy in continuous flow proved to beeasy to use and effective in maintaining volemia and concentration of electrolytes in buffalo calves

Influence of fruit biotypes on the chemical composition and antifungal activity of the essential oils of eugenia uniflora leaves

The multivariate chemical analysis of essential oils of Eugenia uniflora leaves with different fruit colours indicated the presence of three oil clusters regarding sample biotypes. The first cluster included yellowish, dark red and purple fruits with high percentages of germacrene B (11.1-30.7%), germacrone (9.8-54%) and atractylone (0-19.9%). In cluster II, with bright red fruit samples, the major constituents were curzerene (42.0-43.2%), germacrene D (8.7-9.0%) and germacrene A (5.9-8.9%), whereas cluster III included red-orange fruit samples containing high contents of selina-1,3,7(11)-trien-8-one (40.3-55.4%) and selina-1,3,7(11)-trien-8-one epoxide (12.7-24.4%). The clustered oils were investigated against the systemic fungus Paracoccidioides brasiliensis via the broth macrodilution method. The oil from cluster II revealed the most significant result. The yeast form of P. brasiliensis was completely inhibited at a concentration of 62.5 µg mL-1

Teaching resources for the European Open Platform for Prescribing Education (EurOP2E) : a nominal group technique study

© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.The European Open Platform for Prescribing Education (EurOP2E) seeks to improve and harmonize European clinical pharmacology and therapeutics (CPT) education by facilitating international collaboration and sharing problem-based, online, open educational resources. The COVID-19 pandemic forced teachers to switch to virtual modalities, highlighting the need for high-quality online teaching materials. The goal of this study was to establish the online problem-based teaching resources needed to sustain prescribing education during the pandemic and thereafter. A nominal group technique study was conducted with prescribing teachers from 15 European countries. Results were analyzed through thematic analysis. In four meetings, 20 teachers from 15 countries proposed and ranked 35 teaching materials. According to the participants, the most necessary problem-based-online teaching materials related to three overarching themes. Related to learning outcomes for CPT, participants proposed creating prescription scenarios, including materials focusing on background knowledge and resources on personalized medicine and topical/ethical issues such as the prescription's impact on planetary health. Second, related to teaching, they proposed online case discussions, gamification and decision support systems. Finally, in relation to faculty development, they recommend teacher courses, a repository of reusable exam questions and harmonized formularies. Future work will aim to collaboratively produce such materials.This study was funded by the European Union under Erasmus+ grant 2020-1-NL01-KA203-083098info:eu-repo/semantics/publishedVersio

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Associação do reflexo vermelho em recém-nascidos com variáveis neonatais

Objetivou-se investigar o resultado do teste do reflexo vermelho, conhecido como teste do olhinho, e associar as impressões do reflexo com variáveis neonatais. Este é um estudo descritivo, quantitativo, realizado com 190 recém-nascidos de uma maternidade pública, dos quais 187 apresentaram resultado não alterado e três suspeitos. Observaram-se diferentes nuances de coloração do reflexo: em 50 (26,3%) a coloração do reflexo apresentou-se vermelha; 34 (17,9%) laranja-avermelhado; 92 (48,4%) alaranjado; 11 (5,8%) amarelo claro e três (1,6%) com manchas esbranquiçadas. Encontraram-se associações estatisticamente significantes entre o instrumento gradiente de cores e variáveis neonatais: peso (p=0,03), idade gestacional (p=0,019) e oxigenoterapia (p=0,024). Enfermeiros capacitados para prática e avaliação desse teste podem se tornar profissionais em potencial para a prevenção da cegueira infantil.The aim of this study was to investigate the results of the red reflex test and to associate these results with neonatal variables. This descriptive study was conducted with 190 newborns in a public maternity hospital. A total of 187 infants presented no alteration and three presented suspect results. Different shades of reflex color were observed: 50 (26.3%) presented red; 34 (17.9%) orange-red, 92 (48.4%) orange, 11 (5.8%) light yellow and three (1.6%) milky white spots. Statistically significant associations between the color gradient instrument and neonatal variables were found: weight (p=0.03), gestational age (p=0.019) and oxygen therapy (p=0.024). Nurses trained to practice and evaluate this test may become professionals in the potential for the prevention of childhood blindness.Se objetivó investigar el resultado de la prueba del reflejo rojo, conocido como prueba del ojito, y asociar las impresiones del reflejo con variables neonatales. Se trata de un estudio descriptivo, cuantitativo, realizado con 190 recién nacidos de una maternidad pública; de los cuales 187 presentaron resultados no alterados y tres sospechosos. Se observaron diferentes matices de coloración del reflejo: en 50 (26,3%) se presentó rojo; 34 (17,9%) naranja rojizo; 92 (48,4%) anaranjado; 11 (5,8%) amarillo claro y tres (1,6%) con manchas blanquecinas. Se encontraron asociaciones estadísticamente significativas entre el instrumento gradiente de colores y las variables neonatales: peso (p=0,03), edad de gestación (p=0,019) y oxigenoterapia (p=0,024). Enfermeros capacitados para la práctica y evaluación de esa prueba pueden tornarse profesionales en potencial para la prevención de la ceguera infantil

Hundreds of variants clustered in genomic loci and biological pathways affect human height

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.