Effect of the essential oil from Cantinoa carpinifolia (Benth.) Harley & J.F.B.Pastore on efflux of potassium ions from Escherichia coli and Staphylococcus aureus strains

Essential oils are secondary metabolites synthesized from glucose via two basic precursors, terpenes and phenylpropanoids. These compounds present diverse biological activities that reflect the very role they play in plants [1]. One of the most important properties is the antibacterial activity, although there are still few studies regarding the mechanism of action. Cantinoa carpinifolia (Benth.) Harley & J.F.B.Pastore, popularly known as rosman, is a plant species belonging to the Lamiaceae family and whose use in popular medicine is described in the treatment of diseases such as colds, flu, and rheumatism [2]. The objectives of the present work were to extract the essential oil from C. carpinifolia and to evaluate its effect on the efflux of potassium ions from strains of Escherichia coli and Staphylococcus aureus. The essential oil was extracted by the hydrodistillation technique using a modified Clevenger apparatus. The effect of the essential oil on the potassium efflux of bacterial strains was determined by flame photometry [3]. The concentrations tested were 6.25 μL mL-1 and 0.39 μL mL-1 for E. coli and S. aureus, respectively. The cell membrane is a barrier between the external and internal environments of the cell, being permeable to the passage of electrolytes that are important for various cellular functions, such as K+ ions. The leakage of these ions indicates that an increase in permeability or rupture of the cell membrane occurred, affecting the functioning of bacterial cell metabolism and causing lysis. There was no significant variation between the five evaluated times (0, 60, 135, 197 and 267 min) for either of the bacteria nor did the concentration of potassium ions differ statistically when the treatments containing the essential oil and the control (bacterial culture) were compared. These results suggest that the essential oil from C. carpinifolia did not influence the cell membrane permeabilities of E. coli and S. aureus to potassium ions because there was no increase in the concentration of this ion at the evaluated times

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Insights into the role of CuO in the CO2 photoreduction process

Abstract The CO2 photoreduction process to produce light hydrocarbons is known to be influenced by the presence of CuO nanoparticles, but the actual role of this material, whether as a catalyst or a reactant, has not yet been revealed. In this work, we investigate the role of CuO nanoparticles produced by a solvothermal method as a catalyst in CO2-saturated water reaction media under UV light, considering the effects of different electrolytes (Na2C2O4, KBrO3, and NaOH) and temperatures on nanoparticle phase and activity. The electrolyte strongly influenced product selectivity (NaOH led to evolution of CH4, Na2C2O4 to CO, and KBrO3 to O2) and induced CuO phase change. A long-term analysis of these processes indicated that during the initial steps, CuO acted as a reactant, rather than as a catalyst, and was converted to CuCO3.Cu(OH)2, while the as-converted material acted as a catalyst in CO2 photoreduction, with conversion values comparable to those reported in the literature

CuO Decoration Controls Nb 2 O 5 Photocatalyst Selectivity in CO 2 Reduction

The reformation of CO2 through photocatalytic processes to obtain products with high energy value and compatibility with the current energy infrastructure is a compelling strategy to minimize the emission of CO2 into the atmosphere, one of the main greenhouse gases. However, practical application of such a photocatalytic system requires significant efforts for improved CO2 photoreduction performance and product selectivity. Thus, in the present work, CuO nanoparticles were combined with Nb2O5 in order to improve the photocatalytic properties of these semiconductors in the CO2 photoreduction process. Nb2O5/CuO heterojunctions were prepared via a solvothermal treatment method, while the experimental tools, such as FESEM, HRTEM, and DRS, were employed to evaluate the microstructural and electronic properties. We describe how CuO decoration over Nb2O5 adjusts its selectivity for CO2 reduction to CH4, HCOOH, or H3CCOOH in different contents. An investigation of CO2 photoreduction using different electron donors/scavengers (water, sodium oxalate, and potassium bromate) under ultraviolet radiation revealed that its decoration influences local CO production by modifying the selectivity. CO has been confirmed as the main intermediate for HCOOH and CH3COOH production, and CO2 reduction efficiency increases at low CuO content (2.5% wt), leading to the formation of soluble hydrocarbons, and increases for CH4 in higher amounts (10% wt)

Unveiling CuO role in CO2 photoreduction process – Catalyst or reactant?

We systematically investigated CO2 photoreduction catalyzed by CuO from different synthetic methods (solvothermal, coprecipitation and solid-state reaction) to understand which mechanism is prevailing for this reaction. The results showed that CuO acts as a reactant during CO2 reduction through copper carbonate formation rather than a catalyst, but the as-formed Cu2(OH)2CO3 (malachite) is active as catalyst for the same reaction. Significant CO2 conversion was observed during the CuO carbonation process, reducing to lower conversion levels after complete conversion to copper carbonate

First Chemical Constituents from Cordia exaltata Lam and Antimicrobial Activity of Two Neolignans

The phytochemical study of Cordia exaltata Lam. (Boraginaceae) led to the isolation, through chromatographic techniques, of nineteen secondary metabolites: 8,8\u27dimethyl-3,4,3\u27,4\u27-dimethylenedioxy-7-oxo-2,7\u27cyclolignan (1), 8,8\u27-dimethyl-4,5-dimethoxy-3\u27,4\u27-methylenodioxy-7-oxo-2,7\u27cyclolignan (2), sitosterol (3a), stigmasterol (3b), sitosterol-3-O-β-d-glucopyranoside (4a), stigmasterol-3-O-β-d-glucopyranoside (4b), phaeophytin A (5), 132-hydroxyphaeophytin A (6), 173-ethoxypheophorbide A (7), 132-hydroxy-173-ethoxypheophorbide A (8), m-methoxy-p-hydroxybenzaldehyde (9), (E)-7-(3,4-dihydroxyphenyl)-7-propenoic acid (10), 1-benzopyran-2-one (11), 7-hydroxy-1-benzopyran-2-one (12), 2,5-bis-(3\u27,4\u27-methylenedioxiphenyl)-3,4-dimethyltetrahydrofuran (13), 3,4,5,3\u27,5\u27-pentamethoxy-1\u27-allyl-8.O.4\u27-neolignan (14), 3,5,7,3\u27,4\u27-pentahydroxyflavonol (15), 5,7-dihydroxy-4\u27-methoxyflavone (16), 5,8-dihydroxy-7,4’-dimethoxyflavone (17), kaempherol 3-O-β-d-glucosyl-6\u27\u27-α-L-ramnopyranoside (18) and kaempherol 3,7-di-O-α-l-ramnopyranoside (19). Their structures were identified by 1H and 13C-NMR using one and two-dimensional techniques. In addition, the antimicrobial activity of compounds 1, 2, 13 and 14 against bacteria and fungi are reported here for the first time

Estudo clínico-oftálmico e citológico de felinos domésticos com conjuntivite e mantidos em adensamento populacional

As conjuntivites se propagam facilmente em felinos, especialmente em abrigos e domicílios com elevado número de animais, diante dessa realidade objetivou-se com este estudo fazer uma avaliação oftálmica e citológica em felinos domésticos com conjuntivite e mantidos em adensamento populacional. Para tanto, foram estudados 18 animais da espécie felina, provenientes da rotina de atendimento oftálmico de dois abrigos e um domicilio. Dentre os sinais clínicos, houve predomínio de hiperemia conjuntival, quemose, e secreção mucopurulenta. Associados à conjuntivite, foram atendidos felinos apresentando úlcera dendítrica, simbléfaro e Phthisis bulbi. Na citologia, além das células epiteliais, houve maior frequência de neutrófilos, foram encontradas também inclusões citoplasmáticas morfologicamente compatíveis com Chlamydophila felis e bactérias. O estudo permitiu direcionar o diagnóstico com baixo custo e rapidez, sendo possível instituir terapia tópica e/ou sistêmica aos felinos com conjuntivite, além de oportunizar orientações sobre manejo com o objetivo de minimizar a disseminação das oftalmopatia nos animais mantidos em adensamento populacional