bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliação da atividade antiedematogênica, antimicrobiana e mutagênica das sementes de Amburana cearensis (A. C. Smith) (Imburana-de-cheiro)
Authors: Lima L.R. , Cavalcante R.R.L. , Martins M.C.C. , Parente D.M. , Cavalcante A.A.M.C.
Published: August 2013

Foram avaliados os efeitos antiinflamatório, antibacteriano e mutagênico do extrato aquoso das sementes de Amburana cearensis. A atividade antiinflamatória foi avaliada em modelo de edema de pata induzido por carragenina, utilizando o extrato em concentrações de 10 % e 20 % nos grupos experimentais; AAS 10 mg/kg (v.o) no grupo padrão e água destilada no grupo controle. A atividade antimicrobiana foi determinada através do método de diluição em Agar, utilizando concentrações de extrato de 10 %, 7,5 %, 5 %, 2,5 % e 1 % em cepas de Sthaphylococcus aureus ATCC 27853, Escherichia coli ATCC 25922 e Pseudomonas aeruginosas ATCC 25923) e a atividade mutagênica foi determinada pelo teste de Allium cepa, utilizando extrato em concentrações de 0,02 mg/mL, 0,1 mg/mL e 0,5 mg/mL. O extrato aquoso das sementes de Amburana cearensis nas concentrações de 10 % e 20 % apresentou efeito antiedematogênico, estatisticamente significativo a partir de duas horas após administração do flogógeno, e tal efeito persistiu até 24 horas após a indução da resposta inflamatória. Quanto à atividade antibacteriana, o extrato não apresentou ação contra as cepas bacterianas de Sthaphylococcus aureus, Escherichia coli e Pseudomonas aeruginosas nas concentrações testadas. A análise dos resultados do teste de Allium cepa evidenciou ação tóxica (em concentração de 0,5 mg/mL) e mutagênica (micronúcleo 0,1 mg/mL e aberrações cromossômicas 0,1 mg/mL e 0,5 mg/mL) do extrato de Amburana cearensis em células meristemáticas de Allium cepa. Tais resultados sugerem potencial aplicação terapêutica no tratamento da inflamação. Contudo, também demonstram a necessidade de estudar para comprovar a segurança na utilização dessa espécie.
Avaliação da toxicidade aguda e da atividade cicatrizante dos extratos etanólicos das folhas e raízes da Memora nodosa (Silva Manso) Miers (Bignoniaceae)
Authors: Tresvenzol L.M.F , Parente L.M.L. , Lino Júnior R.S. , Fiuza T.S. , Bara M.T.F. , Cunha L.C. , Laxor L.P. , Miguel M.P. , Paula J.R.
Published: August 2013

Memora nodosa (Silva Manso) Miers é uma espécie da flora do Cerrado cujas folhas e caules são utilizados popularmente no tratamento de feridas e úlceras externas, enquanto as raízes são empregadas para dores abdominais e no tratamento da sarna. O objetivo desse trabalho foi avaliar a toxicidade aguda dos extratos etanólicos das folhas e raízes nas doses de 2000 e 5000 mg kg-1 em ratos e camundongos e a atividade cicatrizante das soluções aquosas contendo 2% desses extratos em feridas cutâneas em ratos. A contração das bordas das feridas foi avaliada por análises histológicas e morfométricas após 4, 7 e 14 dias de tratamento e por reação imunohistoquímica após 7 dias de tratamento. Os extratos etanólicos das folhas e raízes não apresentaram toxicidade na dose de 2000 mg kg-1 para ratos e camundongos e na dose de 5000 mg kg-1 para ratos. Nos camundongos, a dose de 5000 mg kg-1 dos extratos das folhas e raízes provocou alterações histológicas no fígado. Não foram observadas diferenças significativas na contração das feridas entre os grupos tratados com os extratos das folhas e das raízes e o controle após 4 e 7 dias de tratamento. Após 14 dias de tratamento, 50% dos animais tratados com o extrato das raízes apresentaram reepitelização total das feridas e reconstrução parcial dos anexos. A alantoína, isolada do extrato etanólico da raiz, pode ser considerada como um dos metabólitos secundários responsáveis pela aceleração da reepitelização.
Assessment of antimicrobial activity in vitro of ethanolic extracts of Banisteriopsis anisandra (A. Juss.) B. Gates (Malpighiaceae)
Authors: Pádua M.S. , Mendes-Costa M.C. , Ferreira J.M.S. , Magalhães J.C. , Castro A.H.F.
Published: August 2013

The aim of this study was to evaluate the antimicrobial activity in vitro of ethanolic extracts of Banisteriopsis anisandra. Tests were performed using the extracts overlay method in the culture medium for phytopathogenic fungi Rhizoctonia solani and Fusarium oxysporum, and disk diffusion for the microorganisms Staphylococcus aureus and Candida albicans. Ethanolic extracts from leaves were prepared by maceration (extract I) and decoction (extract II) at 430.0, 215.0 and 107.5 mg/mL. The growth inhibition of R. solani and F. oxysporum was determined by calculating the mycelia growth speed rate (MGSR) and, in relation C. albicans and S. aureus, it was determined by measuring the inhibition halos. Extracts that caused significant inhibition were also tested at 86.0, 64.5, 43.0 and 21.5 mg/mL for C. albicans and S. aureus. Both extracts showed inhibitory activity on the microorganisms studied. Rizoctonia solani showed lower MGSR in the presence of extract II (107.5 mg/mL) and Fusarium oxysporum showed slight MGSR reduction in the presence of extract I (107.5 mg/mL) and II (107.5 and 215 mg/mL). Ethanolic extracts I and II inhibited the growth of C. albicans, with the highest rates of inhibition observed in the presence of extract II (215.0 mg/mL). For S. aureus, the highest inhibitory activity was observed in the presence of ethanolic extract II, prepared by decoction at 430.0 mg/mL. Results showed a promising antimicrobial activity of extracts of B. anisandra, which may contribute to further studies leading to a future development of medicines to treat human and plant diseases caused by these organisms.
Chemical composition of sage (Salvia officinalis L.) essential oil from the Rio de Janeiro State (Brazil)
Authors: Porte A. , Godoy R.L.O. , Maia-Porte L.H.
Published: August 2013

The purpose of this study was to investigate the chemical composition of the essential oil from fresh leaves of sage (Salvia officinalis L.) from Petrópolis, Rio de Janeiro State, for international trade. The oil was isolated by hydrodistillation in a Clevenger-type apparatus and analyzed through a combination of GC-FID and GC-MS. The yield was 2.3 % on dry basis. Forty-seven constituents were identified according to their chromatographic retention indices and mass spectra, corresponding to 94.90 % of the compounds present. The major constituents of the oil were α-thujone (40.90 %), camphor (26.12 %), α-pinene (5.85 %) and β-thujone (5.62 %). The essential oil studied was similar to those found in several European countries and can be a valuable product for the small farmers from the Petrópolis region in Rio de Janeiro State.
Ineficácia da autorregulamentação das propagandas de bebidas alcoólicas: uma revisão sistemática da literatura internacional
Authors: Vendrame Alan , Pinsky Ilana
Published: August 2013

OBJETIVO: A literatura científica mais recente aponta que a publicidade de bebidas alcoólicas influencia o comportamento, particularmente o consumo precoce e em grandes quantidades por crianças e adolescentes. Da perspectiva da saúde pública, a publicidade de bebidas alcoólicas deve ser restringida. Em muitos países, assim como no Brasil, os limites são estabelecidos pela autorregulamentação (ou seja, controlados pela própria comunidade publicitária). Analisou-se na presente revisão o conjunto dos trabalhos publicados na literatura internacional sobre este tipo de controle. MÉTODO: Realizou-se uma revisão bibliográfica sistemática de trabalhos que investigaram a eficácia da autorregulamentação da publicidade de bebidas alcoólicas. A busca foi feita nas bases de dados Medline, SciELO, Camy e Google Scholar, entre 1991 e 2010, bem como pela técnica de "bola de neve" para a indicação dos principais autores no tema. Foram considerados para o presente propósito 11 artigos. DISCUSSÃO: O conjunto dos trabalhos obtidos aponta que a autorregulamentação da publicidade de bebidas alcoólicas é pouco eficaz, não cumprindo com os objetivos de evitar, por exemplo, publicidade direcionada às crianças e adolescentes. CONCLUSÃO: Outras medidas devem ser consideradas para o controle e a veiculação das propagandas de bebidas alcoólicas, tais como monitoramento independente e controle legal.
Experiências internacionais com o orçamento público por regime de competência
Authors: Monteiro Bento Rodrigo Pereira , Gomes Ricardo Corrêa
Published: August 2013

Com a adoção do regime contábil de competência como base do registro contábil na Contabilidade Aplicada ao Setor Público de diversos países, os governos precisam decidir entre manter o regime de caixa para elaboração dos documentos orçamentários ou ampliar o espectro da mudança também para o campo da geração do orçamento público. O assunto tem sido estudado, especialmente, por governos nacionais e organismos internacionais de forma a verificar a adequação do caminho percorrido por estes países. O presente artigo tem como objetivo iniciar uma discussão importante para o Brasil, em face da futura edição de uma nova lei de finanças públicas e abre caminho para a realização de novos estudos que aprofundem a discussão aqui iniciada. Para isso, foram utilizadas, como fonte dos dados, as pesquisas internacionais realizadas sobre o orçamento de competência, bem como alguns documentos governamentais dos países que adotaram o orçamento por regime de competência. A partir da coleta desses documentos na internet, realizando análise de conteúdo, foi possível identificar as diferenças entre os regimes existentes, bem como vantagens e desvantagens do orçamento por competência. Notadamente, foram identificadas diferenças quanto ao registro de valores referentes a despesas não financeiras (por exemplo, a depreciação), reconhecimento de passivos durante sua geração, ao invés de no momento de seu pagamento. A comparação entre os países que mantiveram o orçamento em caixa depois da adoção da competência com os países que fizeram a adoção da competência para orçamento e contabilidade é importante para verificar até que ponto é fundamental que o mesmo regime seja utilizado para os dois sistemas.
Social disclosure e custo de capital próprio em companhias abertas no Brasil
Authors: Gonçalves Rodrigo de Souza , Medeiros Otávio Ribeiro de , Niyama Jorge Katsumi , Weffort Elionor Farah Jreige
Published: August 2013

Esta pesquisa tem por objetivo analisar a relação entre o nível de social disclosure e o custo de capital próprio em companhias abertas no Brasil. Assume-se a hipótese de que os programas sociais externos promovidos ou apoiados pelas empresas contribuem para a construção da imagem reputacional das organizações, compensando as externalidades, trazendo benefícios sob o ponto de vista econômico, pela relação negativa com o custo do capital. Para testar essa hipótese, foram coletados e analisados os relatórios de responsabilidade social de 83 empresas listadas na Bolsa de Valores, Mercadorias e Futuros de São Paulo (BM), no período de 2005 a 2009. Para avaliação do nível de social disclosure das empresas analisadas, foi utilizado um índice composto de 13 indicadores. O custo de capital próprio foi ajustado ao risco mediante o Capital Asset Pricing Model (CAPM) e testado por meio de regressão com dados em painel com efeitos fixos seccionais. Os resultados evidenciam que há relação negativa entre custo de capital próprio e nível de social disclosure, indicando, para o mercado acionário brasileiro, uma forma semiforte de eficiência de mercado.
Evidenciação ambiental dos resíduos sólidos de companhias abertas no Brasil potencialmente poluidoras
Authors: Voss Barbara de Lima , Pfitscher Elisete Dahmer , Rosa Fabricia Silva da , Ribeiro Maisa de Souza
Published: August 2013

Esta pesquisa tem como motivação a obrigatoriedade das empresas de apresentarem informações ambientais sobre os resíduos sólidos no ano de 2010. Parte da seguinte pergunta de pesquisa: como estão sendo evidenciadas as informações ambientais relativas aos resíduos sólidos das companhias abertas no Brasil potencialmente poluidoras no ano de 2010? Com vista a uma resolução plausível, tem-se como objetivo geral verificar a evidenciação ambiental quanto aos resíduos sólidos das companhias abertas no Brasil potencialmente poluidoras no ano de 2010. Para atingir esse objetivo, são estipulados os seguintes objetivos específicos: (i) propor um modelo para identificar itens de evidenciação ambiental dos resíduos sólidos; (ii) avaliar o nível da evidenciação ambiental e correlacioná-lo com variáveis financeiras. Para a análise dos dados é construído um modelo de análise da evidenciação ambiental dos resíduos sólidos (Waste-Ede), que compreende a junção das ideias contidas no modelo Environmental Disclosure Evaluation, na política nacional de resíduos sólidos (Lei Federal n. 12.305/2010) e nas diretrizes da Global Reporting Initiative (2006). Os resultados demonstram que a maioria das companhias não publicou o relatório de sustentabilidade. A amostra final não probabilística contemplou 86 companhias. Os resultados limitados a essa amostra revelam que as companhias estão evidenciando informações de resíduos sólidos no nível mercado (conforme modelo), com média de 12,44 pontos, e que há correlação significante em 95% do índice Waste-Ede com as variáveis financeiras: investimentos ambientais, ativo total, patrimônio líquido e receita bruta. Conclui-se que, no ano de 2010, as companhias abertas no Brasil potencialmente poluidoras que fizeram parte do estudo respeitaram, provavelmente, as pressões de seus investidores, uma vez que os reguladores não apresentaram poder de enforcement.
Teoria da autodeterminação: uma análise da motivação dos estudantes do curso de ciências contábeis
Authors: Leal Edvalda Araújo , Miranda Gilberto José , Carmo Carlos Roberto Souza
Published: August 2013

A Teoria da Autodeterminação tem sido bastante discutida no campo da motivação para a aprendizagem escolar e, segundo alguns pesquisadores, essa teoria pode ser resumida em um continuum de autodeterminação que indica seis tipos de motivação, os quais variam, qualitativamente, conforme a internalização das regulações externas para o comportamento. Nesse sentido, o presente estudo teve o propósito de avaliar a motivação dos estudantes de Ciências Contábeis de uma universidade pública, à luz da Teoria da Autodeterminação. A amostra da pesquisa foi composta de 259 estudantes matriculados em todos os períodos do Curso de Ciências Contábeis de uma instituição de ensino superior pública brasileira. Os resultados da pesquisa foram analisados por meio da análise fatorial exploratória, a qual identificou sete fatores que explicam 61,09% da variabilidade total dos dados. Verificou-se, neste estudo, que os resultados foram parcialmente convergentes com aqueles encontrados em estudos anteriores e, ainda, a existência de uma motivação bem diversificada para a aprendizagem entre os universitários estudados. De um lado, encontram-se estudantes preocupados em aprofundar o nível de conhecimentos ou em atingir uma fundamentação adequada para o desempenho de sua futura atuação; de outro lado, estão aqueles preocupados apenas com a obtenção do diploma ou interessados em comparecer às aulas para garantir frequência. Esses resultados mostram a relevância de pesquisas sobre o ensino da Contabilidade, uma vez que a área possui peculiaridades epistemológicas que devem ser consideradas no processo de ensino e aprendizagem. É importante ressaltar a relevância de se compreender e de avaliar os níveis motivacionais dos estudantes, possibilitando, assim, o planejamento para incentivar e explorar a motivação em ambientes acadêmicos.
Residual strength of reinforced concrete columns subjected to blast loading
Authors: Park Jong Yil , Kim Min Sook , Scanlon Andrew , Choi Hosoon , Lee Young Hak
Published: August 2013

Failure modes of concrete structures due to blast load vary according to the point of detonation, stand-off distance and TNT charge weight. Usually, columns are the key load-bearing elements in concrete frame structures. They are typically weak, not to long-distance explosive loadings, but to short-distance loadings. The effect of blast loadings occurring within a short distance was examined analytically in this study. Scaled distance (which considers both the stand-off distance and TNT charge weight), various aspect ratios of column sections with the same sectional area and reinforcement ratio, and various arrangements of longitudinal reinforcements with the same sectional area and reinforcement ratio were considered as variables in order to evaluate damage levels and define the relations among these variables with respect to the residual strength of columns after blast. Autodyn was used for the finite-element analysis. It was found that the ratio of residual strength to nominal axial strength of the columns decreased as the contact area of the column to the blast loading became smaller; a denser arrangement of the longitudinal reinforcements using smaller diameter bars showed relatively better residual capacity.
Variations in Highway Stormwater Runoff Quality and Stormwater Treatment Performance in Relation to the Age of Porous Friction Courses
Authors: Moores Jonathan P. , Pattinson Peter E. , Hyde Christian R.
Published: August 2013

A program of highway runoff sampling was conducted at four sites in Auckland, New Zealand. Concentrations of suspended solids, particulate copper, and zinc were significantly lower in runoff from a highway paved with a 1‐year‐old porous friction course (PFC) than in runoff at the other sites. Differences in total metal concentrations were less marked, reflecting relatively high concentrations of dissolved copper and zinc in runoff from the 1‐year‐old PFC. Runoff quality at a highway site that had been paved with a PFC 6 years previously was similar to that discharged from two impermeable roads, indicating a reduction over time in the quality of runoff discharged from PFCs. Runoff from the highways paved with 1‐ and 6‐year‐old PFCs was treated by a grass swale and wet pond, respectively. Both treatments were effective, the former predominantly through the lowering of dissolved metal concentrations and the latter through the lowering of particulate metal concentrations. These results indicate that stormwater treatment can improve the quality of runoff discharged from PFCs, irrespective of their age, provided that treatment is targeted to the predominant contaminant phase present.
Effects of Surface Area and Inflow on the Performance of Stormwater Best Management Practices with Uncertainty Analysis
Authors: Park Daeryong , Roesner Larry A.
Published: August 2013

The performance of stormwater best management practices (BMPs) is affected by BMP geometric and hydrologic factors. The objective of this study was to investigate the effect of BMP surface area and inflow on BMP performance using the k‐C* model with uncertainty analysis. Observed total suspended solids (TSS) from detention basins and retention ponds data sets in the International Stormwater BMP Database were used to build and evaluate the model. Detention basins are regarded as dry ponds because they do not always have water, whereas retention ponds have a permanent pool and are considered wet ponds. In this study, Latin hypercube sampling (LHS) was applied to consider uncertainty in both influent event mean concentration (EMC), Cin, and the areal removal constant, k. The latter was estimated from the hydraulic loading rate, q, through use of a power function relationship. Results show that effluent EMC, Cout, decreased as inflow decreased and as BMP surface area increased in both detention basins and retention ponds. However, the change in Cout, depending on inflow and BMP surface area for detention basins, differed from the change in Cout for retention ponds. Specifically, Cin was more dominantly associated with the performance of the k‐C* model of detention basins than were BMP surface area and inflow. For retention ponds, however, results suggest that BMP surface area and inflow both influenced changes in Cout as well as Cin. These results suggest that sensitive factors in the performance of the k‐C* model are limited to Cin for detention basins, whereas BMP surface area, inflow, and Cin are important for retention ponds.
Size Fractionation of Metals Present in Highway Runoff: Beyond the Six Commonly Reported Species
Authors: Ferreira M. , Lau S.‐L. , Stenstrom M. K.
Published: August 2013

Highway runoff is an important non‐point source of pollutants, especially metals. This study reports monitoring results from 17 storm events at three highway sites for six commonly sampled metals: cadmium, chromium, copper, lead, nickel, and zinc. The study also reports the results of eight additional metals: aluminum, arsenic, cobalt, iron, manganese, selenium, strontium, and vanadium. Soluble phase, defined as passing a 0.45 μm filter, and particulate phase concentrations on four size fractions from 0.45 to larger than 100 μm are reported. The greatest metal masses were typically observed in the 8 to 20 μm fraction. The size distribution shows that sedimentation as a treatment process typically found in stormwater management can remove only 65% of the mass of most particulate phase metal species. Additional processes, such as coagulation or filtration, are needed to obtain greater removal rates. The results indicate the need to study particle size distribution (PSD) in order to better select treatment alternatives or assess environmental impacts.
Performance of Compost Filtration Practice for Green Infrastructure Stormwater Applications
Authors: Faucette Britt , Cardoso Fatima , Mulbry Walter , Millner Pat
Published: August 2013

Urban storm water runoff poses a substantial threat of pollution to receiving surface waters. Green infrastructure, low impact development, green building ordinances, National Pollutant Discharge Elimination System (NPDES) storm water permit compliance, and Total Maximum Daily Load (TMDL) implementation strategies have become national priorities; however, designers need more sustainable, low‐cost solutions to meet these goals and guidelines. The objective of this study was to determine the multiple‐event removal efficiency and capacity of compost filter socks (FS) and filter socks with natural sorbents (NS) to remove soluble phosphorus, ammonium‐nitrogen, nitrate‐nitrogen, E. coli, Enterococcus, and oil from urban storm water runoff. Treatments were exposed to simulated storm water pollutant concentrations consistent with urban runoff originating from impervious surfaces, such as parking lots and roadways. Treatments were exposed to a maximum of 25 runoff events, or when removal efficiencies were ≤ 25%, whichever occurred first. Experiments were conducted in triplicate. The filter socks with natural sorbents removed significantly greater soluble phosphorus than the filter socks alone, removing a total of 237 mg/linear m over eight runoff events, or an average of 34%. The filter socks with natural sorbents removed 54% of ammonium‐nitrogen over 25 runoff events, or 533 mg/linear m, and only 11% of nitrate‐nitrogen, or 228 mg/linear m. The filter socks and filter socks with natural sorbents both removed 99% of oil over 25 runoff events, or a total load of 38,486 mg/linear m. Over 25 runoff events the filter socks with natural sorbents removed E. coli and Enteroccocus at 85% and 65%, or a total load of 3.14 CFUs x 108/linear m and 1.5 CFUs x 109/linear m, respectively; both were significantly greater than treatment by filter socks alone. Based on these experiments, this technique can be used to reduce soluble pollutants from storm water over multiple runoff events.
Nitrate and Phosphate Removal through Enhanced Bioretention Media: Mesocosm Study
Authors: Palmer Eric T. , Poor Cara J. , Hinman Curtis , Stark John D.
Published: August 2013

Bioretention is an evolving type of Green Stormwater Infrastructure (GSI) designed to attenuate peak flows, reduce stormwater volume, and treat stormwater. This article examines the capabilities of a bioretention soil mixture of sand and compost enhanced with aluminum‐based drinking water treatment residuals to reduce nutrients from stormwater runoff. Columns with and without a saturation zone and vegetation were compared to examine their role in removing nitrate and ortho‐phosphate from stormwater. Results show that utilization of a saturation zone can significantly reduce nitrate in effluent water (71% compared to 33% without a saturated zone), even in a newly constructed system. However, ortho‐phosphate reduction was significantly better in the columns without a saturated zone (80%) compared to columns with (67%). Plants did not significantly improve removal. This suggests amendments such as aluminum‐based water treatment residuals for phosphorus removal and a saturation zone for nitrogen removal are needed during the initial establishment period.
Of: Sorption Media for Stormwater Treatment—A Laboratory Evaluation of Five Low‐Cost Media for Their Ability to Remove Metals and Phosphorus from Artificial Stormwater
Authors: Minervini William P.
Published: August 2013

Of: Sorption Media for Stormwater Treatment—A Laboratory Evaluation of Five Low‐Cost Media for Their Ability to Remove Metals and Phosphorus from Artificial Stormwater, T. Wium‐Andersen, A. H. Nielsen, T. Hvitved‐Jacobsen, N. K. Kristensen, H. Brix, C. Arias, J. Vollertsen, 84, 605–616 (2012).
Conditional Hypovascularization and Hypoxia in Islets Do Not Overtly Influence Adult β-Cell Mass or Function
Authors: D'Hoker Joke , De Leu Nico , Heremans Yves , Baeyens Luc , Minami Kohtaro , Ying Cai , Lavens Astrid , Chintinne Marie , Stangé Geert , Magenheim Judith , Swisa Avital , Martens Geert , Pipeleers Daniel , van de Casteele Mark , Seino Susumo , Keshet Eli , Dor Yuval , Heimberg Harry
Published: August 2013

It is generally accepted that vascularization and oxygenation of pancreatic islets are essential for the maintenance of an optimal β-cell mass and function and that signaling by vascular endothelial growth factor (VEGF) is crucial for pancreas development, insulin gene expression/secretion, and (compensatory) β-cell proliferation. A novel mouse model was designed to allow conditional production of human sFlt1 by β-cells in order to trap VEGF and study the effect of time-dependent inhibition of VEGF signaling on adult β-cell fate and metabolism. Secretion of sFlt1 by adult β-cells resulted in a rapid regression of blood vessels and hypoxia within the islets. Besides blunted insulin release, β-cells displayed a remarkable capacity for coping with these presumed unfavorable conditions: even after prolonged periods of blood vessel ablation, basal and stimulated blood glucose levels were only slightly increased, while β-cell proliferation and mass remained unaffected. Moreover, ablation of blood vessels did not prevent β-cell generation after severe pancreas injury by partial pancreatic duct ligation or partial pancreatectomy. Our data thus argue against a major role of blood vessels to preserve adult β-cell generation and function, restricting their importance to facilitating rapid and adequate insulin delivery.
Increased Persistent Sodium Current Due to Decreased PI3K Signaling Contributes to QT Prolongation in the Diabetic Heart
Authors: Lu Zhongju , Jiang Ya-Ping , Wu Chia-Yen C. , Ballou Lisa M. , Liu Shengnan , Carpenter Eileen S. , Rosen Michael R. , Cohen Ira S. , Lin Richard Z.
Published: August 2013

Diabetes is an independent risk factor for sudden cardiac death and ventricular arrhythmia complications of acute coronary syndrome. Prolongation of the QT interval on the electrocardiogram is also a risk factor for arrhythmias and sudden death, and the increased prevalence of QT prolongation is an independent risk factor for cardiovascular death in diabetic patients. The pathophysiological mechanisms responsible for this lethal complication are poorly understood. Diabetes is associated with a reduction in phosphoinositide 3-kinase (PI3K) signaling, which regulates the action potential duration (APD) of individual myocytes and thus the QT interval by altering multiple ion currents, including the persistent sodium current INaP. Here, we report a mechanism for diabetes-induced QT prolongation that involves an increase in INaP caused by defective PI3K signaling. Cardiac myocytes of mice with type 1 or type 2 diabetes exhibited an increase in APD that was reversed by expression of constitutively active PI3K or intracellular infusion of phosphatidylinositol 3,4,5-trisphosphate (PIP3), the second messenger produced by PI3K. The diabetic myocytes also showed an increase in INaP that was reversed by activated PI3K or PIP3. The increases in APD and INaP in myocytes translated into QT interval prolongation for both types of diabetic mice. The long QT interval of type 1 diabetic hearts was shortened by insulin treatment ex vivo, and this effect was blocked by a PI3K inhibitor. Treatment of both types of diabetic mouse hearts with an INaP blocker also shortened the QT interval. These results indicate that downregulation of cardiac PI3K signaling in diabetes prolongs the QT interval at least in part by causing an increase in INaP. This mechanism may explain why the diabetic population has an increased risk of life-threatening arrhythmias.
GAD65 Autoantibodies Detected by Electrochemiluminescence Assay Identify High Risk for Type 1 Diabetes
Authors: Miao Dongmei , Guyer K. Michelle , Dong Fran , Jiang Ling , Steck Andrea K. , Rewers Marian , Eisenbarth George S. , Yu Liping
Published: August 2013

The identification of diabetes-relevant islet autoantibodies is essential for predicting and preventing type 1 diabetes (T1D). The aim of the current study was to evaluate a newly developed electrochemiluminescence (ECL)-GAD antibody (GADA) assay and compare its sensitivity and disease relevance with standard radioassay. The assay was validated with serum samples from 227 newly diagnosed diabetic children; 68 prediabetic children who were prospectively followed to T1D; 130 nondiabetic children with confirmed islet autoantibodies to insulin, GAD65, IA-2, and/or ZnT8 longitudinally followed for 12 ± 3.7 years; and 181 age-matched, healthy, antibody-negative children. The ECL-GADA assay had a sensitivity similar to that of the standard GADA radioassay in children newly diagnosed with T1D, prediabetic children, and high-risk children with multiple positive islet autoantibodies. On the other hand, only 9 of 39 nondiabetic children with only a single islet autoantibody (GADA only) by radioassay were positive for ECL-GADA. GADA not detectable by ECL assay is shown to be of low affinity and likely not predictive of future diabetes. In conclusion, the new ECL assay identifies disease-relevant GADA by radioassay. It may help to improve the prediction and correct diagnosis of T1D among subjects positive only for GADA and no other islet autoantibodies.
Coxsackievirus B1 Is Associated With Induction of β-Cell Autoimmunity That Portends Type 1 Diabetes
Authors: Laitinen Olli H. , Honkanen Hanna , Pakkanen Outi , Oikarinen Sami , Hankaniemi Minna M. , Huhtala Heini , Ruokoranta Tanja , Lecouturier Valérie , André Philippe , Harju Raimo , Virtanen Suvi M. , Lehtonen Jussi , Almond Jeffrey W. , Simell Tuula , Simell Olli , Ilonen Jorma , Veijola Riitta , Knip Mikael , Hyöty Heikki
Published: August 2013

The rapidly increasing incidence of type 1 diabetes implies that environmental factors are involved in the pathogenesis. Enteroviruses are among the suspected environmental triggers of the disease, and the interest in exploring the possibilities to develop vaccines against these viruses has increased. Our objective was to identify enterovirus serotypes that could be involved in the initiation of the disease process by screening neutralizing antibodies against 41 different enterovirus types in a unique longitudinal sample series from a large prospective birth-cohort study. The study participants comprised 183 case children testing persistently positive for at least two diabetes-predictive autoantibodies and 366 autoantibody-negative matched control children. Coxsackievirus B1 was associated with an increased risk of β-cell autoimmunity. This risk was strongest when infection occurred a few months before autoantibodies appeared and was attenuated by the presence of maternal antibodies against the virus. Two other coxsackieviruses, B3 and B6, were associated with a reduced risk, with an interaction pattern, suggesting immunological cross-protection against coxsackievirus B1. These results support previous observations suggesting that the group B coxsackieviruses are associated with the risk of type 1 diabetes. The clustering of the risk and protective viruses to this narrow phylogenetic lineage supports the biological plausibility of this phenomenon.
Peroxynitrite-Dependent Zinc Release and Inactivation of Guanosine 5′-Triphosphate Cyclohydrolase 1 Instigate Its Ubiquitination in Diabetes
Authors: Zhao Yu , Wu Jiliang , Zhu Huaiping , Song Ping , Zou Ming-Hui
Published: August 2013

Aberrant degradation of guanosine 5′-triphosphate cyclohydrolase 1 (GTPCH1) with consequent deficiency of tetrahydrobiopterin is considered the primary cause for endothelial dysfunction in diabetes. How GTPCH1 becomes susceptible to the degradation remains unknown. We hypothesized that oxidation and release of the zinc ion by peroxynitrite (ONOO−), a potent oxidant generated by nitric oxide and superoxide anions, instigates GTPCH1 ubiquitination and degradation. Zinc contents, GTPCH1 ubiquitination, and GTPCH1 activity were assayed in purified GTPCH1, endothelial cells, and hearts from diabetic mice. Exogenous ONOO− dose-dependently released zinc, inhibited its activity, and increased the ubiquitin binding affinity of GTPCH1 in vitro and in endothelial cells. Consistently, high glucose (30 mmol/L) inhibited GTPCH1 activity with increased ubiquitination, which was inhibited by antioxidants. Furthermore, mutation of the zinc-binding cysteine (141) (C141R or C141A) significantly reduced GTPCH1 activity and reduced its half-life but increased GTPCH1 ubiquitination, indicating an essential role of the zinc ion in maintaining the catalytic activity and stability of GTPCH1. Finally, GTPCH1 ubiquitination and degradation markedly increased in parallel with decreased GTPCH1 activity in the aortas and hearts of diabetic mice, both of which were attenuated by the inhibitors of ONOO− in mice in vivo. Taken together, we conclude that ONOO− releases zinc and inhibits GTPCH1, resulting in its ubiquitination and degradation of the enzyme.
Lower “Awake and Fed Thermogenesis” Predicts Future Weight Gain in Subjects With Abdominal Adiposity
Authors: Piaggi Paolo , Krakoff Jonathan , Bogardus Clifton , Thearle Marie S.
Published: August 2013

Awake and fed thermogenesis (AFT) is the energy expenditure (EE) of the nonactive fed condition above the minimum metabolic requirement during sleep and is composed of the thermic effect of food and the cost of being awake. AFT was estimated from whole-room 24-h EE measures in 509 healthy subjects (368 Native Americans and 141 whites) while subjects consumed a eucaloric diet. Follow-up data were available for 290 Native Americans (median follow-up time: 6.6 years). AFT accounted for ∼10% of 24-h EE and explained a significant portion of deviations from expected energy requirements. Energy intake was the major determinant of AFT. AFT, normalized as a percentage of intake, was inversely related to age and fasting glucose concentration and showed a nonlinear relationship with waist circumference and BMI. Spline analysis demonstrated that AFT becomes inversely related to BMI at an inflection point of 29 kg/m2. The residual variance of AFT, after accounting for covariates, predicted future weight change only in subjects with a BMI >29 kg/m2. AFT may influence daily energy balance, is reduced in obese individuals, and predicts future weight gain in these subjects. Once central adiposity develops, a blunting of AFT may occur that then contributes to further weight gain.
Synthesis of new (arylcarbonyloxy)aminopropanol derivatives and the determination of their physico-chemical properties
Authors: Tengler Jan , Kapustíková Iva , Stropnický Ondřej , Mokrý Petr , Oravec Michal , Csöllei Jozef , Jampílek Josef
Published: August 2013

Eight hydrochlorides of 3-{2-[(2/4-fluorophenoxy)-ethylamino]}-2-hydroxypropyl-4-alkoxybenzoates and four hydrochlorides of 3-tert-butylamino-2-hydroxypropyl-4-butoxybenzoates were prepared as potential antagonists of the β1-adrenergic receptor (beta-blockers). A multistep synthesis of these compounds is described as well as their detailed analytical characterization. The pharmacokinetic properties of these weak base compounds are significantly influenced by their acid-base dissociation constant, pK a. The knowledge of this value is crucial for new drug development. This paper is aimed at developing a methodology that utilizes pH-dependent 1H NMR spectroscopy for its routine analysis. The selected predicted physico-chemical parameters of the new (arylcarbonyloxy)aminopropanols (i.e., aryloxyaminopropanol derivatives) were compared with the model drugs esmolol and flestolol.
Archaeometric investigations on naturally and thermally-aged iron-gall inks using different tannin sources
Authors: Costa Antonio , Fonseca Nazareth , Carvalho Sheyla , Santos Fernanda , Barki Luana , Freitas Denise , Herbst Marcelo , Lutterbach Márcia
Published: August 2013

This paper investigates the behavior of paper strips containing iron-gall inks prepared with tannins from different sources, subjected to natural and thermally-induced aging. Results indicate that inks containing initial concentrations of ferrous sulphate ranging from 0.2 to 10.0 g are amenable to treatment with calcium phytate, and thata good correlation exists between the recovery of excess iron and the initial concentration. Infrared spectra showed an absorption band at 1,750 cm−1, typical of esther, solely in the samples prepared with a condensed tannin. The condensed nature of this tannin produced a different oxidation pattern, with iron removal inferior to those observed from inks produced with hydrolisable tannins. When tannic acid was used ferrous iron removals ranged from 0.050 to 1.800 g, decreasing to 0.5 g in the presence of copper; the same behavior was observed for the remaining hydrolisable tannins, with a lower recovery from the condensed tannin. The adopted natural aging procedure released a higher amount of ferrous iron compared to ASTM thermal aging. This was probably due to the marked effect of humidity, not considered in the thermal procedure. A series of archaeometric possibilities were used to help elucidate the degradation of cellulose strips impregnated with iron-gall inks.
Oligomers-model building in protonation equilibria of sitagliptin
Authors: Meloun Milan , Ferenčíková Zuzana , Niesnerová Irena , Pekárek Tomáš
Published: August 2013

Mixed protonation constants of sitagliptin phosphate at various ionic strengths I (mol kg−1) in range 0.01 and 0.50 and at 298.15 K are determined using FBSTAC4 and HYPERQUAD nonlinear regression analyses of the potentiometric titration curve. At a low concentration c L = 1.1 mmol kg−1 the monomers L, LH, LH2, LH3 and LH4 dominate, while for a concentration range from c L = 13.7 to 24.7 mmol kg−1 dimers L2H2, L2H3, L2H4 and L2H are mainly present. The regression programme has almost no influence on the precision of the protonation constants. The accuracy of the protonation constants log βqr depends on the accuracy of the group parameters. As two group parameters c L,0, c H,T are ill-conditioned in a model, their determination is therefore uncertain: both can significantly cause a systematic error in the estimated common parameters log10βqr . Fitness tests using regression diagnostics have proven the reliability of the parameter estimates.
Differential pulse adsorptive stripping voltammetric determination of methotrexate using a functionalized carbon nanotubes-modified glassy carbon electrode
Authors: Oliveira Geiser , Janegitz Bruno , Zucolotto Valtencir , Fatibello-Filho Orlando
Published: August 2013

A glassy carbon electrode (GC) containing multiwalled functionalized carbon nanotubes (MWCNTs) immobilized within a dihexadecylhydrogenphosphate film (DHP) is proposed as a nanostructured platform for determination of methotrexate (MTX) concentration (a drug used in cancer treatment) using differential pulse adsorptive stripping voltammetry (DPAdSV). The voltammograms for a MTX solution using MWCNTs-DHP/GC electrode presented an oxidation peak potential at 0.98 V vs. Ag/AgCl (3.0 mol L−1 KCl) in a 0.1 mol L−1 sulphuric acid. The apparent heterogeneous electron transfer rate constant of 0.46 s−1 was calculated. The recovery area of 2.62×10−9 mol cm2 was also obtained. Under the optimal experimental conditions, the analytical curve was linear in the MTX concentration range from 5.0×10−8 to 5.0×10−6 mol L−1, with a detection limit of 3.3×10−8 mol L−1. The MWCNTs-DHP/GC electrode can be easily prepared and was applied for the determination of MTX in pharmaceutical formulations, with results similar to those obtained using a high-performance liquid chromatography comparative method.
Self-assembly of acetylcholinesterase on gold nanoparticles electrodeposited on graphite
Authors: Dimcheva Nina , Horozova Elena , Ivanov Yavor , Godjevargova Tzonka
Published: August 2013

The immobilisation of AChE enzyme through chemisorption on Au-modified graphite was examined with view of its prospective application in the design of membraneless electrochemical biosensors for the assay of enzyme inhibitors. The developed immobilisation protocol has been based on a two-stage procedure, comprising i) electrodeposition of gold nanostructures on spectroscopic graphite; followed by ii) chemisorption of the enzyme onto gold nanoparticles. Both the coverage of the electrode surface with Au nanostructures and the conditions for enzyme immobilisation were optimised. The proposed electrode architecture together with the specific type of enzyme immobilisation allow for a long-term retaining of the enzyme catalytic activity. The extent of inhibition of the immobilised acetylcholinesterase enzyme by the organophosphorous compound monocrotophos has been found to depend linearly on its concentration over the range from 50 to 400 nmol mL−1 with sensitivity 77.2% inhibition per 1 µmol mL−1 of monocrotophos.
Epoxy resin modified with amine as an effective complexing agent of metal cations
Authors: Kurczewska Joanna , Schroeder Grzegorz
Published: August 2013

A simple synthesis of a material capable of metal cation removal is proposed. The material was a derivative of epoxy resin containing amine groups. It is insoluble in water and in this study it was characterized by elemental analysis and infrared spectroscopy. The sorbent obtained was tested for its ability to remove coper(II), cadmium(II) and lead(II) from water solutions. The tests were performed for different concentrations of metal ions (10–200 mg L−1) and at different pH (2.0–9.0). The effects of temperature and stirring time, as well as reusability of the sorbent were also studied in batch experiments. In the optimum conditions, the decrease in the cation concentration in aqueous solutions was observed in the order Cu>Pb>Cd but for each ion the decrease was at least 50% of the initial concentration. The sorbent has demonstrated high effectiveness in cation sorption and after regeneration it can be applied repeatedly in the process described.
Ionic liquids based on 2-chloroethyltrimethylammonium chloride (CCC) as plant growth regulators
Authors: Praczyk Tadeusz , Zakrocka Katarzyna , Wyrzykowska Danuta , Niemczak Michał , Pernak Juliusz
Published: August 2013

Plant growth regulator — 2-chloroethyltrimethylammonium chloride (CCC) was converted into ionic liquid in the metathesis reaction. New forms of CCC as ILs were stable in air as well in contact with water and organic solvents. The biological action of the cation (CCC) in ILs was preserved. Type of anion determined hydrophobicity and hydrophilicity of the whole molecule and it also influenced the biological activity of the plant growth regulator. All of the investigated salts retarded growth of winter wheat stems and most of them increased yield at the same time, when compared to control and standard 2-chloroethyltrimethylammonium chloride.
Polymer conjugates with potential biological activity based on new derivatives of 2-mercaptobenzoxazole-synthesis and characterization
Authors: Aparaschivei Rǎdiţa , Şunel Valeriu , Holban Mihaela , Popa Marcel , Desbrieres Jacques
Published: August 2013

New potentially biologically active compounds derived from 2-mercapto-benzoxazole were synthesized and coupled on polymeric support of poly (maleic anhydride-alt-vinyl acetate) for the preparation of polymer-drug conjugates with controlled drug release. All compounds were characterized by elemental and spectroscopy (FT-IR, 1H-NMR) analysis. The toxicological tests recommend the products for further laboratory screening.
A theoretical study of the limits of the acidity of carbon acids in phase transfer catalysis in water and in liquid ammonia
Authors: Alkorta Ibon , Elguero José , Gallo Roger
Published: August 2013

The acidities of a large number of carbon acids have been theoretically calculated for the gas-phase and for DMSO solution. The gas-phase values, both ΔH and ΔG, are very well correlated with the available experimental data. From the calculated ΔG values in DMSO and the pKas in the same solvent, a homogeneous set of pK a (DMSO) values was devised that was used to generate pK a (water). These last pK as were used to establish the limits of the acidity of carbon acids for reactions under PTC conditions both alkylations and H/D exchange. A step further led to the pK as in liquid ammonia and from them to the virtual use of PTC using liquid ammonia instead of water.
New 5-bromo-2-hydroxybenzaldehyde S-ethylisothiosemicarbazone and its mixed-ligand Cu(II) complex with imidazole: synthesis, characterization and DFT calculation
Authors: Takjoo Reza , Akbari Alireza , Ahmadi Mehdi , Rudbari Hadi , Bruno Giuseppe
Published: August 2013

A new Schiff base ligand of 5-bromo-2-hydroxybenzaldehyde S-ethyl-isothiosemicarbazone (H2L) was synthesized and its mixed-ligand Cu(II) complex was also prepared by reaction of Cu(NO3)2·3H2O with H2L and imidazole. Their structures were fully characterized by elemental analysis, FT-IR, molar conductivity and UV-Vis methods. The analytical data suggest that the metal, H2L and imidazole ratios in the Schiff base complex are 1:1:1. Single crystal diffraction was also used to better understand the molecular structure of the Cu(II) complex. The results of physico-chemical analyses of the Schiff base complex reveal the coordination geometry around the central atom is square planar. The H2L ligand (NNO donor) is coordinated to the metal center as a tridentate bionegatively agent. Another position of the square planar geometry is occupied by the imidazole ligand. Furthermore, computational studies of the new complex were performed by carrying out DFT calculations. Geometry optimization and natural band analysis of the complex is discussed in further detail.
Separation of trace amounts palladium by SiO2/TiO2/Ce nanoparticles prior to flame atomic absorption spectrometry determination in anodic slime and wastewater samples
Authors: Mohammadi Sayed , Hamidian Hooshang , Moeinadini Zahra
Published: August 2013

In the present work, a new SiO2/TiO2/Ce, nanoparticle was synthesed using sol-gel method and evaluated as an adsorbent for preconcentration trace amounts of Pd(II) ions. The characterization of the nanoparticles has been studied by transmission electron microscope and X-ray diffraction. The preconcentration method is based on palladium adsorption onto the surface of nanoparticle at pH 8.5. The main factors affecting Pd(II) adsorption, such as pH of sample solution, concentration and volume of eluent, sample volume, interfering of the coexisting ions and flow rate of sample and eluent were investigated and optimized. At optimum conditions, linearity was maintained between 4.0 to 1000.0 ng mL−1. Detection limit based on 3Sb/m was 2.3 ng mL−1. Seven replicate determinations of a solution containing of 12.5 µg palladium gave a relative standard deviation ±1.7%. According to the Langmuir linear model, the maximum adsorption capacity of palladium was found to be 34.5 mg g−1. Finally, the feasibility of the proposed method for Pd(II) determination was assessed by analysis of certified reference materials, anodic slime and wastewater samples and satisfactory results were obtained.