Contribuição ao estudo da atividade antifúngica de Maytenus ilicifolia Mart. ex Reiss., Celastraceae

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M. M. Cunico

Full Text Available Maytenus ilicifolia Mart. ex Reiss, Celastraceae, espinheira-santa, é nativa em muitas partes da América do Sul, sendo encontrada no sul do Brasil. É utilizada no tratamento de gastrite, úlceras e outras desordens do estômago, na forma de decocção das folhas ou extrato liofilizado em cápsulas. Neste trabalho, estudou-se a atividade antifúngica do seu extrato etanólico sobre o crescimento micelial dos fungos fitopatogênicos Colletotrichum acutatum, Fusarium oxysporum e Cylindrocladium spathulatum. Na comparação do crescimento micelial de isolados desses fungos em BDA (Batata Dextrose Agar, adicionados do extrato etanólico da espinheira-santa, foi observado que o mesmo inibiu em mais de 10% o crescimento micelial de Fusarium oxysporum, nas três concentrações avaliadas (0,2; 0,4 e 0,6mg/mL, estimulou o crescimento micelial de Colletotrichum acutatum em mais de 30% na concentração de 0,2mg/mL, e algumas de suas frações inibiram o desenvolvimento de Cylindrocladium spathulatum.

Comparação do teor de taninos entre duas espécies de espinheira-santa (Maytenus aquifolium Mart.e Maytenus ilicifolia Mart. ex Reissekcultivadas no Horto Medicinal do Refúgio Biológico Bela Vista - RBBV da Itaipu Binacional - Foz do Iguaçu, PR - Brasil.

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P.R. HOLNIK

2015-09-01

Full Text Available RESUMO As duas espécies de espinheira-santa Maytenus aquifolium Mart. e Maytenus ilicifolia Mart. ex Reissek pertencentes à família Celastraceae e têm sido intensamente exploradas nas populações nativas devido seu alto valor medicinal. O grande interesse pela espinheira-santa é para o tratamento de gastrites, úlceras gástricas e duodenais. O efeito antiulcerogênico está relacionado com a presença de polifenóis totais, mais especificamente com os taninos. Este trabalho teve como objetivo comparar o teor de taninos entre essas duas espécies cultivadas no Horto Medicinal do Refúgio Biológico Bela Vista - RBBV da Itaipu Binacional no município de Foz do Iguaçu, PR - Brasil. Foram realizadas duas coletas com intervalo de um mês para cada espécie e para a quantificação foi realizada a análise por espectrofotometria segundo a Farmacopeia Brasileira V. Os resultados foram analisados através do teste de variância (ANOVA e a diferença no teor de taninos foi evidenciada pelo teste Tukey, a 5% de nível de significância empregando-se o software SISVAR. Foram obtidos em média 0,61% para o lote 1 e 2 de Maytenus aquifolium e (3,90% para Maytenus ilicifolia, resultando em uma média de 84,35% de taninos a mais para Maytenus ilicifolia em comparação com Maytenus aquifolium concluindo assim que as espécies não devem ser intercambiáveis.

Caracterização dos constituintes poliméricos da Maytenus ilicifolia por relaxação nuclear de ¹H por RMN no estado sólido Characterization of Maytenus ilicifolia Samples by ¹H NMR relaxation in the solid state

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Mônica S. de M. Preto

2011-01-01

Full Text Available A Maytenus ilicifolia, conhecida como espinheira-santa, é uma planta popular de uso diverso, como chá é empregada no combate a problemas de doenças gástricas e da diabetes, por exemplo. As plantas possuem em sua constituição polímeros naturais como polissacarídeos, politerpenoides, celulose e fibras. O estudo dos constituintes poliméricos nesse tipo de material tem importância fundamental tanto na identificação, ou seja, qualificação quanto na adulteração da planta. É sabido que podem ser encontrados diversos produtos rotulados como sendo originário da mesma planta, entretanto, muitas das vezes a origem da planta é similar, mas não a mesma, o que pode gerar algum desconforto ou não atividade biológica dos chás quando da ingestão destes. Na literatura não são encontrados muitos trabalhos que envolvam a caracterização comparativa dos constituintes poliméricos, como polissacarídeos e fibras presentes em amostras de origens distintas, para comprovação de adulteração destes produtos. Uma técnica que pode ser promissora para este tipo de estudo é a Ressonância Magnética Nuclear (RMN em estado sólido, já que permite analisar a amostra in natura não sendo um método destrutivo ou invasivo. Esta espectroscopia analisa amostras em campos magnéticos de diferentes potências ou forças. Neste trabalho é apresentado um estudo de caracterização dos constituintes poliméricos majoritários presentes na M. ilicifolia. Três amostras foram estudadas: uma amostra denominada controle e duas comerciais. O estudo envolveu a determinação dos tempos de relaxação spin-rede (T1 do ¹H utilizando a técnica de campo cíclico rápido (FFC, numa gama de frequências que variou de 100 kHz a 10 MHz. Assim, o principal objetivo deste trabalho foi estudar a possibilidade de utilização da RMN de baixo campo magnético na elaboração de um método expedito de análise que permita realizar a caracterização estrutural

A quantitative validated method using liquid chromatography and chemometric analysis for evaluation of raw material oF Maytenus ilicifolia (Schrad. Planch., Celastraceae

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Flávio Luís Beltrame

2012-01-01

Full Text Available The hydroalcoholic extracts prepared from standard leaves of Maytenus ilicifolia and commercial samples of espinheira-santa were evaluated qualitatively (fingerprinting and quantitatively. In this paper, fingerprinting chromatogram coupled with Principal Component Analysis (PCA is described for the metabolomic analysis of standard and commercial espinheira-santa samples. The epicatechin standard was used as an external standard for the development and validation of a quantitative method for the analysis in herbal medicines using a photo diode array detector. This method has been applied for quantification of epicatechin in commercialized herbal medicines sold as espinheira-santa in Brazil and in the standard sample of M. ilicifolia.

A quantitative validated method using liquid chromatography and chemometric analysis for evaluation of raw material oF Maytenus ilicifolia (Schrad.) Planch., Celastraceae

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Beltrame, Flávio Luís; Mainardes, Rubiana Mara; Khalil, Najeh Maissar; Prestes, Rosilene Aparecida; Nogueira, Alessandro; Demiate, Ivo Mottin; Cass, Quezia Bezerra

2012-01-01

The hydroalcoholic extracts prepared from standard leaves of Maytenus ilicifolia and commercial samples of espinheira-santa were evaluated qualitatively (fingerprinting) and quantitatively. In this paper, fingerprinting chromatogram coupled with Principal Component Analysis (PCA) is described for the metabolomic analysis of standard and commercial espinheira-santa samples. The epicatechin standard was used as an external standard for the development and validation of a quantitative method for...

Development and validation of an HPLC method for the determination of epicatechin in Maytenus ilicifolia (Schrad. Planch., Celastraceae Desenvolvimento e validação de um método de CLAE para a determinação da epicatequina em Maytenus ilicifolia (Schrad. Planch., Celastraceae

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Gisely Cristiny Lopes

2010-11-01

Full Text Available A simple, reproducible and efficient high-performance liquid chromatography (HPLC method was developed. Water (0.05% TFA:acetonitrile (0.05% TFA was used as the mobile phase in a gradient system for the determination of epicatechin (EP in leaves of Maytenus ilicifolia (Schrad. Planch. The analysis was performed using an RP C-18 column (5 µm as the stationary phase, with a flow rate of 0.8 mL/min, at a wavelength of 210 nm for detection and determination. The main validation parameters of the method were also determined. The calibration curve was found to be linear, with a range of 10-120 µg/mL (EP. The correlation coefficient of the linear regression analysis was within 0.9988, and the detection and quantification limits were 28.61 and 86.77 µg/mL, respectively. The content of EP was successfully determined, with satisfactory reproducibility and recovery. Recovery of the EP was 99.32%. The method was successfully applied to the determination of epicatechin in leaves of M. ilicifolia. The interlaboratorial evaluation showed the reproducibility of the method with a relative standard deviation of 14.62%.Um método simples, reprodutível e eficiente de cromatografia líquida de alta eficiência (CLAE foi desenvolvido. Água (0,05% TFA:acetonitrila (0,05% TFA foi utilizado como fase móvel em um sistema de gradiente para a determinação da epicatequina (EP em folhas de Maytenus ilicifolia (Schrad. Planch., Celastraceae. A análise foi realizada utilizando coluna RP C-18 (5 µm como fase estacionária, com vazão de 0,8 mL/min, e comprimento de onda de 210 nm para a detecção e determinação. Os principais parâmetros de validação do método foram determinados. A curva analítica apresentou-se linear no intervalo de 10-120 µg/mL (EP. O coeficiente de correlação da análise de regressão linear foi de 0,9988, o limite de detecção e o limite de quantificação foram de 28,61 e 86,77 µg/mL, respectivamente. O conteúdo do EP foi determinado

Evaluation of the antiulcerogenic activity of Maytenus robusta (Celastraceae) in different experimental ulcer models.

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de Andrade, Sérgio Faloni; Lemos, Marivane; Comunello, Eros; Noldin, Vânia Floriani; Filho, Valdir Cechinel; Niero, Rivaldo

2007-09-05

Maytenus robusta (Celastraceae) is used in folk medicine for the treatment of stomach ulcers and is very well adapted to the South of Brazil. Maytenus ilicifolia is the main species of the Celastraceae family, and is used in the treatment of gastric ulcers. However, Maytenus ilicifolia is presently at the stage of extinction, due to indiscriminate use in Brazil. Thus, the use of Maytenus robusta in phytotherapeutic preparations, instead of Maytenus ilicifolia, is suggested. However, there have been no reports regarding the antiulcer activity of Maytenus robusta extract. Therefore, this study was carried out to evaluate the antiulcerogenic property of the hydroalcoholic extract of aerial parts of Maytenus robusta. The antiulcer assays were performed using the following protocols: nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, and stress-induced ulcer. The effects of the extract on gastric content volume, pH and total acidity, using the pylorus ligated model, were also evaluated. In the ethanol-induced ulcer model, it was observed that the treatment with Maytenus robusta extract significantly reduced the lesion index in 75.1 +/- 8.6, 85.0 +/- 9.2, 86.6 +/- 7.4 and 75.5 +/- 5.3 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (omeprazole 30 mg/kg), respectively. Also were observed significant inhibition in lesion index in the indomethacin-induced ulcer model, being the decrease of the 62.5 +/- 7.1, 62.5 +/- 6.1, 63.6 +/- 5.5 and 96.2 +/- 3.6 for groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Results similar were observed in the stress-induced ulcer model, where the inhibition of ulcer lesions were 71.3 +/- 5.5, 72.7 +/- 6.3, 76.5 +/- 7.1 and 92.3 +/- 7.5 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Regarding the model of gastric

Friedelin Synthase from Maytenus ilicifolia: Leucine 482 Plays an Essential Role in the Production of the Most Rearranged Pentacyclic Triterpene

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Souza-Moreira, Tatiana M.; Alves, Thaís B.; Pinheiro, Karina A.; Felippe, Lidiane G.; de Lima, Gustavo M. A.; Watanabe, Tatiana F.; Barbosa, Cristina C.; Santos, Vânia A. F. F. M.; Lopes, Norberto P.; Valentini, Sandro R.; Guido, Rafael V. C.; Furlan, Maysa; Zanelli, Cleslei F.

2016-11-01

Among the biologically active triterpenes, friedelin has the most-rearranged structure produced by the oxidosqualene cyclases and is the only one containing a cetonic group. In this study, we cloned and functionally characterized friedelin synthase and one cycloartenol synthase from Maytenus ilicifolia (Celastraceae). The complete coding sequences of these 2 genes were cloned from leaf mRNA, and their functions were characterized by heterologous expression in yeast. The cycloartenol synthase sequence is very similar to other known OSCs of this type (approximately 80% identity), although the M. ilicifolia friedelin synthase amino acid sequence is more related to β-amyrin synthases (65-74% identity), which is similar to the friedelin synthase cloned from Kalanchoe daigremontiana. Multiple sequence alignments demonstrated the presence of a leucine residue two positions upstream of the friedelin synthase Asp-Cys-Thr-Ala-Glu (DCTAE) active site motif, while the vast majority of OSCs identified so far have a valine or isoleucine residue at the same position. The substitution of the leucine residue with valine, threonine or isoleucine in M. ilicifolia friedelin synthase interfered with substrate recognition and lead to the production of different pentacyclic triterpenes. Hence, our data indicate a key role for the leucine residue in the structure and function of this oxidosqualene cyclase.

Development and validation of an HPLC method for the determination of epicatechin in Maytenus ilicifolia (Schrad. Planch., Celastraceae

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Gisely Cristiny Lopes

2010-09-01

Full Text Available A simple, reproducible and efficient high-performance liquid chromatography (HPLC method was developed. Water (0.05% TFA:acetonitrile (0.05% TFA was used as the mobile phase in a gradient system for the determination of epicatechin (EP in leaves of Maytenus ilicifolia (Schrad. Planch. The analysis was performed using an RP C-18 column (5 µm as the stationary phase, with a flow rate of 0.8 mL/min, at a wavelength of 210 nm for detection and determination. The main validation parameters of the method were also determined. The calibration curve was found to be linear, with a range of 10-120 µg/mL (EP. The correlation coefficient of the linear regression analysis was within 0.9988, and the detection and quantification limits were 28.61 and 86.77 µg/mL, respectively. The content of EP was successfully determined, with satisfactory reproducibility and recovery. Recovery of the EP was 99.32%. The method was successfully applied to the determination of epicatechin in leaves of M. ilicifolia. The interlaboratorial evaluation showed the reproducibility of the method with a relative standard deviation of 14.62%.

Quantitative determination for cytotoxic Friedo-nor-oleanane derivatives from five morphological types of Maytenus ilicifolia (Celastraceae) by reverse-phase high-performance liquid chromatography.

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Buffa Filho, Waldemar; Corsino, Joaquim; Bolzani, da Silva Vanderlan; Furlan, Maysa; Pereira, Ana Maria S; França, Suzelei Castro

2002-01-01

Five different morphological types of Maytenus ilicifolia of the same age and harvested under the same conditions showed distinct accumulations of some friedo-nor-oleananes. A rapid, sensitive and reliable reverse-phase HPLC method (employing an external standard) was used for the determination of the cytotoxic triterpenoids, 20 alpha-hydroxymaytenin, 22 beta-hydroxymaytenin, maytenin, celastrol and pristimerin in each of the five types. Well resolved peaks with good detection response and linearity in the range 1.0-100 micrograms/mL were obtained.

Technical aspects of the production of dried extract of Maytenus ilicifolia leaves by jet spouted bed drying.

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Cordeiro, Daniel S; Oliveira, Wanderley P

2005-08-11

This work presents an evaluation of the performance of jet spouted bed with inert particles for production of dried extracts of Maytenus ilicifolia leaves. The development of the extraction procedure was carried-out with the aid of three factors and three levels Box-Behnken design. The effects of the extraction variables, temperature (Text); stirring time (theta); and the ratio of the plant to solvent mass (m(p)/m(s)) on the extraction yield were investigated. The drying performance and product properties were evaluated through the measurement of the product size distribution, loss on drying (Up), flavonoid degradation (D) and, process thermal efficiency (eta). These parameters were measured as a function of the inlet temperature of the spouting gas (Tgi), the feed mass flow rate of the concentrated extract relative to mass flow rate of the spouting gas (Ws/Wg), the ratio between the feed flow rate of spouting gas relative to feed flow rate at a minimum spouting condition (Q/Qms) and the static bed height (H0). A powder product with a low degradation of active substances and good physical properties were obtained for selected operating conditions. These results indicate the feasibility of this drying equipment for the production of dried extracts of M. ilicifolia Martius ex Reiss leaves.

Enraizamento de miniestacas de espinheira-santa (Maytenus ilicifolia Mart. ex Reissek em diferentes substratos Rooting of espinheira-santa (Maytenus ilicifolia Mart. ex Reissek minicuttings on different substrates

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Daniela Macedo de Lima

2009-04-01

Full Text Available Pertencente à família Celastraceae, a espinheira-santa (Maytenus ilicifolia Mart. ex Reissek é uma espécie medicinal nativa da região sul do Brasil, utilizadas no tratamento de gastrite e úlceras gástricas. Estudos sobre a produção de mudas por meio de estaquia demonstraram que esta espécie é considerada de difícil enraizamento. Objetivou-se, no presente trabalho, avaliar os efeitos de diferentes substratos no enraizamento de miniestacas de espinheira-santa. Miniestacas apicais foram coletadas a partir das brotações das minicepas de 10 meses de idade, mantidas em casa-de-vegetação e confeccionadas com 3 a 4cm de comprimento, mantendo-se duas folhas com a superfície reduzida à metade. O plantio foi realizado em caixas contendo areia e tubetes contendo casca de arroz carbonizada, Plantmax HT® ou vermiculita de granulometria fina como substrato. As miniestacas foram mantidas em casa-de-vegetação com nebulização intermitente e 90 dias após o plantio, foram avaliadas as características: porcentagem de estacas enraizadas, número e comprimento médio de raízes, porcentagem de estacas com calos, sobrevivência e mortalidade. O delineamento experimental foi inteiramente casualizado, com 4 tratamentos e 4 repetições de 22 estacas por parcela. A análise estatística revelou que os substratos areia (92,04%, casca de arroz carbonizada (88,66% e Plantmax HT® (94,31% apresentaram índices de enraizamento significativamente superiores à vermiculita (78,41%, além de menores taxas de mortalidade, sendo que a propagação vegetativa de espinheira-santa por meio de miniestaquia é viável.Espinheira-santa (Maytenus ilicifolia Mart. ex Reissek, which belongs to the Celastraceae family, is a medicinal species native to the south region of Brazil, used in gastritis and gastric ulcer treatment. Studies about plant production by cutting have shown that this species is considered difficult to root. The purpose of this work was to evaluate

Nitric oxide-dependent vasorelaxation induced by extractive solutions and fractions of Maytenus ilicifolia Mart ex Reissek (Celastraceae) leaves.

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Rattmann, Yanna D; Cipriani, Thales R; Sassaki, Guilherme L; Iacomini, Marcello; Rieck, Lia; Marques, Maria C A; da Silva-Santos, José E

2006-04-06

This study reveals that an ethanolic supernatant obtained from an aqueous extractive solution prepared from residues of methanolic extracts of ground leaves of Maytenus ilicifolia is able to cause a concentration- and endothelium-dependent relaxation in pre-contract rat aorta rings, with EC(50) of 199.7 (190-210) microg/ml. The non-selective nitric oxide synthase inhibitors l-NAME and l-NMMA abolished this effect, while superoxide dismutase and MnTBAP (a non-enzymatic superoxide dismutase mimetic) enhanced it. Further, relaxation induced by this ethanolic supernatant have been strongly inhibited by the guanylate cyclase inhibitors methylene blue and ODQ, as well as by the potassium channel blockers 4-aminopyridine and tetraethylammonium, but was unchanged by the cyclooxygenase inhibitor indomethacin and the membrane receptor antagonists atropine, HOE-140 and pirilamine. Partition of the ethanolic supernatant between H(2)O and EtOAc generated a fraction several times more potent, able to fully relax endothelium-intact aorta rings with an EC(50) of 4.3 (3.9-4.8) microg/ml. (13)C NMR spectrum of this fraction showed signals typical of catechin. This study reveals that the leaves of M. ilicifolia possess one or more potent substances able to relax endothelium-intact rat aorta rings, an event that appears to involve nitric oxide production, guanylate cyclase activation and potassium channel opening.

In vitro antiviral activity of Brazilian plants (Maytenus ilicifolia and Aniba rosaeodora) against bovine herpesvirus type 5 and avian metapneumovirus.

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Kohn, L K; Queiroga, C L; Martini, M C; Barata, L E; Porto, P S S; Souza, L; Arns, C W

2012-10-01

Medicinal plants are well known for their use in traditional folk medicine as treatments for many diseases including infectious diseases. Six Brazilian medicinal plant species were subjected to an antiviral screening bioassay to investigate and evaluate their biological activities against five viruses: bovine herpesvirus type 5 (BHV-5), avian metapneumovirus (aMPV), murine hepatitis virus type 3, porcine parvovirus and bovine respiratory syncytial virus. The antiviral activity was determined by a titration technique that depends on the ability of plant extract dilutions (25 or 2.5 µg/mL) to inhibit the viral induced cytopathic effect and the extracts' inhibition percentage (IP). Two medicinal plant species showed potential antiviral activity. The Aniba rosaeodora Ducke (Lauraceae) extract had the best results, with 90% inhibition of viral growth at 2.5 µg/mL when the extract was added during the replication period of the aMPV infection cycle. The Maytenus ilicifolia (Schrad.) Planch. (Celastraceae) extracts at a concentration of 2.5 µg/mL exhibited antiviral activity during the attachment phase of BHV-5 (IP = 100%). The biomonitored fractionation of the active extracts from M. ilicifolia and A. rosaeodora could be a potential tool for identifying their active compounds and determining the exact mechanism of action.

Atividade antioxidante das folhas de espinheira-santa - Maytenus ilicifolia Mart. ex Reiss., secas em diferentes temperaturas

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Myrian Lane Soares Negri

Full Text Available Maytenus ilicifolia Mart. ex Reiss, a espinheira-santa verdadeira, é largamente utilizada para tratamento de gastrites e úlceras estomacais. O seu valor terapêutico é atribuído principalmente aos polifenóis (flavonóides e taninos e triterpenos. Os polifenóis são bastante estudados e estão relacionados à atividade antioxidante exercida pela planta. Existem vários métodos para avaliar a atividade antioxidante, a qual pode ser medida a capacidade antioxidante total utilizando o método de formação do complexo fosfomolibdênio e a atividade antioxidante em relação à redução de um radical, utilizando-se o DPPH (2,2-difenil-1-picrilhidrazila. A atividade antioxidante das folhas de espinheira-santa seca em diferentes temperaturas foi avaliada, visando verificar a possível influência das temperaturas de secagens e seu poder antioxidante. Foram utilizadas cinco temperaturas (40, 50, 60, 70 e 80 ºC e uma temperatura de secagem de rotina, de um produtor/beneficiador de plantas medicinais. As menores temperaturas apresentaram as maiores atividades antioxidantes.

Efectos sobre la temperatura, frecuencia respiratoria, frecuencia cardiaca y electrocardiograma de Maytenus macrocarpa (Ruiz & Pav.) Briq. (chuchuhuasi)

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Huaccho Rojas, Juan Jesús; Cavero Aguilar, Evelyn Sally; Quezada Rojas, Melissa Andrea; Lara Paredes, Andrea Mercedes; Lluen Escobar, Silvana Estela; Paragulla Bocángel, Ahmed Alberto; Rojas Villacorta, Fernando Junior; Loja Herrera, Berta; Alvarado Yarasca, Ángel Tito; Mujica Calderón, José; Salazar Granara, Alberto Alcibíades

2012-01-01

Introducción: estudios de árboles del género Maytenus, especies forsskaoliana, ilicifolia y krukovii revelan efectos depresores a nivel cardiovascular sobre la presión arterial y frecuencia cardiaca. Objetivos: analizar experimentalmente los efectos de las hojas de Maytenus macrocarpa "chuchuhuasi" sobre la frecuencia cardiaca, patrones electrocardiográficos, frecuencia respiratoria, y temperatura. Métodos: investigación de tipo exploratorio, analítico y experimental. Se uti...

Co-processed extracts of Cassia angustifolia Vahl, Fabaceae, and Maytenus ilicifolia (Schrad. Planch., Celastraceae, for production of high load tablets

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Verônica M. L. Alves

2011-06-01

Full Text Available The aim of this study was to investigate the feasibility of a co-processing technique for improving the manufacturing properties of Maytenus ilicifolia (Schrad. Planch., Celastraceae, and Cassia angustifolia Vahl, Fabaceae, extracts in order to obtain tablets containing a high dose of such extracts. An experimental mixture design was used to optimise the formulation composition. Flowability parameters, such as compressibility index, time flow and angle of repose, were determined. Additional important industrial parameters, such as granulometry, bulk density and moisture stability, were also studied. The results demonstrated that co-processing technique was able to improve the flowability of vegetal extracts, making these materials suitable for a direct compression process. The contour plots revealed that formulations with a higher amount of lactose produced the best flow results as well as a larger particle size and a greater bulk density. Tablets from co-processed extracts containing lactose as majority diluent showed appropriate physical-chemical characteristics and presented a more stable moisture sorption behaviour compared to commercial gelatine capsules.

Modeling of the overal kinetic extraction from Maytenus aquifolia using compressed CO2

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M. Minozzo

2012-12-01

Full Text Available In Brazil, the species Maytenus aquifolia and Maytenus ilicifolia are widely used in popular medicine in the form of teas for stomach and ulcer illness treatment. Despite the great interest in Maytenus aquifolia therapeutic properties and the fact that it is an abundant and native plant growing in Brazil, there is a lack of information in the literature concerning the extraction at high pressures. In this context, this work is focused on the mathematical modelling of the packed-bed extraction of Maytenus aquifolia with compressed CO2. Three mathematical models were used to represent the experimental data. The experiments were performed in a laboratory-scale unit, evaluating the effects of temperature (293 to 323 K, pressure (100 to 250 bar, and extraction time on the yield of the extracts. Results show that the extraction temperature and solvent density exerted a pronounced effect on yield. The mathematical model of Sovová was the most suitable to represent the experimental extraction data of M. aquifolia.

Determinação espectrométrica dos flavonóides das folhas de Maytenus (Celastraceae e de Passiflora (Passifloraceae e comparação com método CLAE-UV

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Regina de A. O. Chabariberi

Full Text Available Este trabalho apresenta uma modificação dos procedimentos descritos nas Farmacopéias Francesa e Européia para a análise de flavonoides de Passiflora incarnata L., Passifloraceae, por espectrometria UV-Visível e propõe a sua aplicação na determinação dos flavonoides totais das folhas da espinheira-santa (Maytenus aquifolium Mart. e Maytenus ilicifolia (Schrad. Planch., Celastraceae e do maracujá (Passiflora edulis Sims. e Passiflora alata Curtis, Passifloraceae. Os resultados obtidos por espectrometria no UV-Visível foram comparados aos obtidos por cromatografia líquida de alta eficiência (CLAE-UV, encontrando-se resultados estatisticamente similares entre os métodos espectrométrico modificado da Farmacopéia Francesa e CLAE-UV.

Perfil cromatográfico dos componentes polifenólicos de Maytenus ilicifolia mart. (Celastraceae

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Haroudo Satiro Xavier

Full Text Available Buscando-se fornecer subsídios farmacognósticos para uma melhor caracterização da "espinheira santa" (Mavtenus ilicifolia, elaborou-se urn perfil cromatográfico a partir de folhas do vegetal disponíveis no comércio local. Heterosídeos flavonólicos a proantocianidinas foram constatados, podendo perfeitamente estas moléculas, servirem como marcadores para afeição da originalidade da droga ou de sua qualidade coma insumo farmacêutico.

Efeito do composto "mais vida" na ativação de macrófagos de ratos diabéticos Effects of "mais vida", a commercial natural mix, on the activation of macrophages from diabetic rats

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E.L. França

2012-01-01

Full Text Available O objetivo deste trabalho foi avaliar a atividade funcional de macrófagos de ratos diabéticos, através da liberação do ânion superóxido, na presença do composto "mais vida". Os animais foram divididos em dois grupos, controle (N=20 e diabético (N=20. Avaliou-se a glicemia, massa corpórea e a liberação de superóxido pelos macrófagos de baço de ratos. O composto "mais vida" foi obtido através da mistura de extratos de sete plantas, sendo Orbignia martiana Rodr., Tabebuia avellanedae L.G., Arctium lappa L., Rosa centifolia L., Maytenus ilicifolia Mart., Vernonia condensata Baker e Thuja occidentalis L. Observou-se que glicemia foi maior no grupo diabético. A liberação espontânea do ânion superóxido pelos macrófagos foi menor no grupo diabético. O composto "mais vida", independente dos níveis glicêmicos, aumentou a liberação de superóxido dos macrófagos. Quando as células foram estimuladas pelos extratos vegetais isolados, também houve aumento na liberação do ânion superóxido pelos macrófagos em ambos os grupos. As maiores liberações de superóxido ocorreram quando os macrófagos foram estimulados pela Thuja occidentalis L., Rosa centifolia L., Tabebuia avellanedae L.G. e Maytenus ilicifolia Mart. Estes dados sugerem que a ativação de macrófagos pelo composto "mais vida" pode representar um mecanismo alternativo de defesa para infecções em indivíduos diabéticos.This study investigated the effects of "mais vida", a commercial natural mix, on macrophages functional activity as evaluated by the superoxide release in diabetic rats. The animals were divided into two groups, control (N = 20 and diabetic (N = 20. This was achieved by determining blood glucose weight and the superoxide released by spleen macrophages. The "mais vida" mix was obtained by the combination of extracts from seven medicinal species, which were: Orbignia martiana Rodr., Tabebuia avellanedae L.G., Arctium lappa L., Rosa centifolia L

RAPD-PCR na identificação molecular de plantas medicinais regulamentadas pelo Sistema Único de Saúde do Brasil | RAPD-PCR in molecular identification of medicinal plants regulated by the Unified Health System in Brazil

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José Luiz Neves Aguiar

2015-08-01

Full Text Available O desenvolvimento de metodologia altamente discriminatória para a identificação e caracterização de genótipos das espécies de plantas medicinais regulamentadas pelo sistema público de saúde brasileiro (SUS é de suma importância para o controle de qualidade destas espécies como matérias-primas na produção de medicamentos fitoterápicos, consequentemente, minimizar o risco sanitário associado à ineficácia terapêutica devido ao uso de matéria prima de identidade duvidosa. Por isto, foi utilizado o método RAPD-PCR para a elaboração de um perfil genético de três espécies de plantas medicinais regulamentadas pelo SUS do Brasil: Mikania glomerata, Maytenus ilicifolia e Schinus terebinthifolius, a partir de exemplares destas plantas, que foram cedidas pela Coleção Temática de Plantas Medicinais do Instituto de Pesquisas do Jardim Botânico do Rio de Janeiro. Os 60 iniciadores utilizados no RAPD-PCR com o DNA das três espécies geraram 1284 produtos amplificados que variaram de 100-1500 pb. Foram selecionados cinco iniciadores que geraram no total 76 fragmentos entre 200-1100 pb com astrês espécies, sendo os iniciadores OPG18, OPA7 e OPG17 para a Mikania glomerata, os iniciadores OPG20, OPC13 e OPA11 para a Maytenus ilicifolia e OPA4, OPA18 e OPG14 para a Schinus terebinthifolius e os iniciadores OPA17 e OPC6 para as três espécies. Os perfis resultantes permitiram a identificação eficiente das espécies. Foram identificados iniciadores que geraram um único fragmento que poderão servir para desenhar um iniciador específico, que poderá ser usado na identificação da planta em produtos como monofarmacos e associações. ----------------------------------------------------------------------------------------------- Development of a highly discriminatory method for the identification of genotypes and species of medicinal plants regulated by the Brazilian public health system (SUS is of paramount importance for the

Anatomia foliar de Maytenus Mol. emend Mol. (Celastraceae, ocorrente no Estado do Rio de Janeiro, Brasil Leaf anatomy of the Maytenus Mol. emend Mol. (Celastraceae in Rio de Janeiro State, Brazil

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Ana Joffily

2005-09-01

Full Text Available Este trabalho aborda o estudo anatômico de cinco espécies do gênero Maytenus Mol. emend. Mol. (Celastraceae. O gênero é o maior da família, e está representado no Brasil por aproximadamente 80 espécies. Maytenus é um gênero polifilético, necessitando de trabalhos adicionais para nova circunscrição. Maytenus ardisiaefolia Reiss., M. brasiliensis Mart., M. cestrifolia Reiss., M. communis Reiss. e M. obtusifolia Mart. são de difícil identificação, devido à semelhança dos verticilos reprodutivos, e pela variação na forma e no tamanho das folhas. As estruturas anatômicas observadas nas diversas partes da folha mostraram-se muito semelhantes nas espécies estudadas, sendo de valor taxonômico e de provável importância filogenética para o gênero Maytenus. A organização da epiderme e estratos subepidérmicos em M. obtusifolia demonstrou ser caráter diagnóstico importante na comparação com M. ardisiaefolia, e a ocorrência de cristais aciculares nas células epidérmicas de M. communis e de M. ardisiaefolia, que as separam de M. cestrifolia, que não apresenta cristais, apontaram a anatomia como importante ferramenta a ser explorada nos estudos taxonômicos das demais espécies do gênero. A observação e descrição das verrugas suberosas na epiderme da lâmina foliar poderá contribuir para a taxonomia das Celastraceae.This paper describes anatomical approaches to study the Genus Maytenus Mol. Emnd. Mol. (Celastraceae. The genus is the largest in the family Celastraceae, and in Brazil is represented by approximately 80 species. Maytenus is a polyphyletic genus and additional research is required to better understand its taxonomy. Maytenus ardisiaefolia Reiss., M. brasiliensis Mart., M. cestrifolia Reiss., M. communis Reiss. and M. obtusifolia Mart. are difficult to identify because of similarities in their reproductive structures and variations in the size and shape of their leaves. The anatomical structures observed

Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines

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da Silva, G.; Serrano, R.; Silva, O.

2011-01-01

Maytenus heterophylla (Eckl. and Zeyh.) N.K.B. Robson and Maytenus senegalensis (Lam.) Exell are two African shrubs or trees that go under the common name of spike thorn, which belong to the Celastraceae family. Different plant parts of this species are largely used in traditional medicine for infectious and inflammatory diseases treatment. Several studies have been reported for both these species, but there are no recent review articles focusing microscopic, phytochemistry and pharmacological studies. The aim of this review is to summarize the information about these two African traditional medicines. Such kind of data can be applied in future experimental work and may guide future studies, namely in the field of validation of traditional medicine. PMID:22470236

Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines.

Science.gov (United States)

da Silva, G; Serrano, R; Silva, O

2011-01-01

Maytenus heterophylla (Eckl. and Zeyh.) N.K.B. Robson and Maytenus senegalensis (Lam.) Exell are two African shrubs or trees that go under the common name of spike thorn, which belong to the Celastraceae family. Different plant parts of this species are largely used in traditional medicine for infectious and inflammatory diseases treatment. Several studies have been reported for both these species, but there are no recent review articles focusing microscopic, phytochemistry and pharmacological studies. The aim of this review is to summarize the information about these two African traditional medicines. Such kind of data can be applied in future experimental work and may guide future studies, namely in the field of validation of traditional medicine.

Novidades taxonômicas em Maytenus (Celastraceae para a flora da Argentina

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Leonardo Biral

2014-01-01

Full Text Available No decorrer dos estudos taxonômicos de Maytenus Molina desenvolvidos pelo autor para a América do Sul, novidades taxonômicas para a flora argentina são apresentadas. Essas novidades incluem três sinonimizações, cinco lectotipificações e um novo registro de ocorrência no país. Dessa forma objetiva-se atualizar as informações disponíveis sobre o presente táxon na Argentina.

Variabilidade em matrizes de acessos de espinheira-santa Variability in matrices of espinheira-santa accessions

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Márcio Paim Mariot

2008-04-01

Full Text Available Maytenus ilicifolia e M. aquifolium são espécies nativas do Brasil, popularmente conhecidas como espinheira-santa, sendo indicadas para gastrite e para úlcera estomacal. A Embrapa Clima Temperado e a Universidade Federal de Pelotas (UFPel mantêm um banco de germoplasma destas espécies. Com o objetivo de identificar a variabilidade fenotípica para alguns caracteres morfológicos em matrizes de espinheira-santa, estimar a dissimilaridade e agrupar os acessos através de análises multivariadas, 105 acessos foram caracterizados morfologicamente. Foram avaliados os caracteres comprimento e largura de fruto, número de sementes por fruto, comprimento e largura de folha, relação comprimento/largura de folha e número de espinhos por folha. Foi estimada a distância euclidiana e os acessos foram agrupados pelo método de otimização de Tocher. Foi observada uma ampla variabilidade para todos os caracteres analisados. O número de espinhos por folha foi o caráter que mais contribuiu para a divergência. Os caracteres morfológicos permitiram separar os acessos em sete grupos. A maior dissimilaridade foi entre os acessos 57 (M. ilicifolia e 91 (M. aquifolium. Não foi evidenciada uma separação de acordo com a localização geográfica dos acessos. Na análise de agrupamento foram identificados dois grupos que apresentavam tanto acessos de M. ilicifolia quanto de M. aquifolium, o que indica proximidade filogenética entre estas espécies.Maytenus ilicifolia and M. aquifolium are native Brazilian species popularly known as espinheira-santa, being indicated for gastritis and stomach ulcer. Embrapa Clima Temperado and Universidade Federal de Pelotas (UFPel keep a gene bank of these species. With the objective of identifing phenotypic variability for some morphological characters in matrices of espinheira-santa, estimating dissimilarity and clustering accessions through multivariate analysis, 105 accessions had been morphologically characterized

Anatomia foliar de soja infectada por Phakopsora pachyrhizi H. Sydow & Sydow e tratadas com extratos vegetais Leaf anatomy of soybean infected with Phakopsora pachyrhizi H. Sydow & Sydow and treated with plant extracts

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R.M. Mussury

2012-01-01

Full Text Available Folhas de Glycine max (L. Merril,infectadas pelo fungo Phakopsora pachyrhizi H. Sydow & Sydow e tratadas com extratos vegetais foram avaliadas, visando determinar in vivo as modificações anatômicas nas diferentes estruturas/tecidos foliares, além de reconhecer prováveis mecanismos de defesa. Folhas de soja cultivar 181 provenientes do quinto nó foram inoculadas com fungo e tratadas com diferentes extratos vegetais, água e álcool 70%. Para comparação foram analisadas a anatomia das folhas sadia e infectada e realizadas medidas nas estruturas/tecidos foliares. Na folha infectada, observou-se destruição da epiderme e parênquima lacunoso, visível proliferação de tricomas e cutícula espessada, principalmente na face abaxial. Observou-se a presença de compostos fenólicos nas células da epiderme quando rompida, em função do crescimento micelial. Nas folhas infectadas e tratadas com os extratos vegetais de Azadirachta indica, Maytenus ilicifolia e Allium sativum, as estruturas/tecidos vegetais apresentaram aumento de espessura por alongamento celular.Glycine max (L. Merril leaves, infected by the fungus Phakopsora pachyrhizi H. Sydow & Sydow and treated with plant extracts, were evaluated with the aim of determining in vivo the anatomical modifications in different leaf structures and of identifying probable defense mechanisms. Leaves from the 181 soybean cultivar originated from the fifth node were inoculated with the fungus and treated with different plant extracts, water and alcohol at 70%. For comparison, the anatomy of the healthy and infected leaves was analyzed and the leaf structures were measured. In the infected leaf, there was destruction of the epidermis and lacunar parenchyma, apparent trichome proliferation and denser cuticle, especially on the abaxial surface. There were also phenolic compounds in ruptured epidermis cells, due to mycelium growth. In the infected leaves treated with Azadirachta indica, Maytenus

SOBRE LA PRESENCIA DE CONDALIA BUXIFOLIA (RHAMNACEAE Y MAYTENUS SPINOSA (CELASTRACEAE EN URUGUAY

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MARCHESI EDUARDO

2004-12-01

Full Text Available A partir de la revisión de muestras de herbarios y nuevos relevamientos florísticosconcluimos que Maytenus spinosa (Celastraceae, especie citada para la flora deUruguay, fue reiteradamente confundida con Condalia buxifolia (Rhamnaceae,cuya presencia en Uruguay pasó inadvertida durante casi un siglo. Maytenus spinosadebe ser excluida de la flora del Uruguay.

Efecto de Maytenus macrocarpa“Chuchuhuasi” en el sistema reproductor masculino del ratón (Mus musculus)

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Acosta, Láyonal G.; Vásquez, Jonathan; Núñez, Víctor; Pino, José; Shiga, Betty

2014-01-01

Maytenus macrocarpa(chuchuhuasi) is native tree of the Peruvian Amazon used as traditional medicine for the treatment of many diseases, but its effect on the male reproductive system has not yet been elucidated. The aim of this study is evaluate the effect of aqueous extract of M. macrocarpa in daily doses for 7 days on reproductive parameters of male mice. We used C57BL mature male mice divided into 2 groups (n= 10), Control Group (C): 0.9% NaCl and Treatment group (T): Aqueous extract ...

Estudo anatômico do xilema secundário da raiz e do caule de Maytenus guyanensis Klotzsch ex Reissek (Celastraceae Anatomic study of secundary xylem of root and stem of Maytenus guyanensis Klotzsch ex Reissek (Celastraceae

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Ressiliane Ribeiro Prata

2009-01-01

Full Text Available Maytenus guyanensis é uma planta medicinal, conhecida popularmente por chichuá, possuindo ação analgésica, antiinflamatória, afrodisíaca e antireumática. O objetivo do presente trabalho foi analisar as características estruturais, da raiz e caule desta espécie como contribuição aos trabalhos anatômicos já realizados para o gênero. O material botânico foi coletado na Reserva Florestal Adolpho Ducke, Manaus/AM onde foram selecionados três indivíduos e de cada um deles retirados fragmentos de 1cm³ do caule e raiz. Amostras foram seccionadas em micrótomo de deslize e coradas com safranina e azul de astra. A análise estrutural revelou-se de acordo com o registrado pela literatura para o gênero. O xilema secundário da raiz e do caule apresentam parênquima axial apotraqueal, raios multisseriados, heterogêneos, vasos solitários, de distribuição difusa, uniforme, seção circular, com parede delgada, pontoações intervasculares alternas e areoladas.Maytenus guyanensis, known popularly as chichuá, possess analgesic, anti-inflammatory, aphrodisiac and anti-rheumatic agents. The object of this present wor was the anatomical analysis of material collected of this species at the Adolpho Ducke Forest Reserve. Stem and root fragments of 1cm were removed from 3 selected individuals. Sections from the stem and root were cut with slide microtome, and stained with astra blue and safranin. The structural analysis of stems and roots was in accordance with the literature available for the Maytenus genus. The secondary xylem of the root and stem presented parenchyma axial apotracheal, multiseriates, heterogeneous rays, solitary vessels, of diffuse distribution, uniform, circular section, with thin wall, bordered and alternate intervascular pits.

Antidiarrheal activity of extracts from Maytenus gonoclada and inhibition of Dengue virus by lupeol

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FERNANDO C. SILVA

Full Text Available ABSTRACT Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.

Genotoxicity of plant extracts

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Vera M. F. Vargas

1991-01-01

Full Text Available Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome. Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990 the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.

Aedes aegypti Larvicidal Sesquiterpene Alkaloids from Maytenus oblongata.

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Touré, Seindé; Nirma, Charlotte; Falkowski, Michael; Dusfour, Isabelle; Boulogne, Isabelle; Jahn-Oyac, Arnaud; Coke, Maïra; Azam, Didier; Girod, Romain; Moriou, Céline; Odonne, Guillaume; Stien, Didier; Houël, Emeline; Eparvier, Véronique

2017-02-24

Four new sesquiterpene alkaloids (1-4) with a β-dihydroagrofuran skeleton and a new triterpenoid (5) were isolated from an ethyl acetate extract of Maytenus oblongata stems. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS and ECD experiments. The M. oblongata stem EtOAc extract and the pure compounds isolated were tested for larvicidal activity against Aedes aegypti under laboratory conditions, and compounds 2 and 3 were found to be active.

Anatomía de leño de Maytenus vitis-idaea y M. viscifolia (Celastraceae

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Ana María Giménez

2012-12-01

Full Text Available Es objetivo del trabajo describir el leño de Maytenus vitis-idaea Griseb. y M. viscifolia Griseb. (Celastraceae y determinar rasgos ecoanatómicos. Las muestras fueron recolectadas del bosque natural en la localidad Guampacha, Sierras de Guasayán, Santiago del Estero, Argentina (distrito chaqueño serrano. Cinco individuos de cada especie fueron seleccionados al azar, obteniéndose una rodaja a 0.3 m. En las descripciones del leño se usó la terminología del Comité de Nomenclatura de IAWA. Los rasgos fundamentales del leño de Maytenus se resumen en: poros pequeños, numerosos, vasos pequeños, miembros de vasos cortos y anillos de crecimiento angostos. El leño de las dos especies estudiadas se caracteriza por presentar porosidad difusa a semicircular, anillos de crecimiento tipo 5b; poros numerosos y pequeños, parénquima axial de distribución apotraqueal en bandas discontinuas de una sola hilera de células, con tendencia a reticulado; escaso paratraqueal unilateral y difuso en agregados, radios heterogéneos; presencia de fibrotraqueidas. Las principales diferencias anatómicas radican en el tipo de poros, fundamentalmente solitarios en M. vitis-idaea y la presencia de radios de mayor longitud en M. viscifolia. Ambas maderas presentan rasgos xerofiticos notorios.Wood anatomy of Maytenus vitis-idaea. y M. viscifolia (Celastraceae. Is objective of this study to describe the wood anatomy of Maytenus vitis-idaea Griseb. and M. viscifolia Griseb. (Celastraceae and to determine ecoanatomy features. The samples were collected from natural forest in Guampacha, Guasayán, Santiago del Estero, Argentina (Chaco Serrano district. Five individuals were randomly selected; being obtained a track to 0.3 m. IAWA Committee on Nomenclature terminology was used in wood descriptions. Xylem features of Maytenus be summarized as: numerous small pores, short vessel members and growth rings narrow. The wood of the two species were characterized by diffuse to

Pharmacological studies of ethanolic extracts of Maytenus rigida Mart (Celastraceae in animal models

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Vanda Lucia dos Santos

Full Text Available The crude ethanol extract (EEOH of the bark of Maytenus rigida Mart (Celastraceae a plant used in Brazil herbal traditional medicine, was tested for anti-inflammatory, antiulcer and antidiarrhoeal activities in animal models. No acute toxicological sign was observed in animals treated with the highest dose (5000 mg/kg, p.o. or 2000 mg/kg i.p. of EEOH. The extract doses of 250, 500 or 750 mg/kg revealed a significant inhibitory effect (P < 0,01 in carrageenin-induced rat paw oedema and exhibited ulcer-protective properties against ethanol-induced ulceration in rats. An anti-diarrhoeal activity (P < 0.01 was also observed in castor-oil-induced diarrhoeal in mice. The intestinal transit was significantly (P < 0.01 reduced, however the pretreatment did not reduce the weight of intestinal contents. These results support the popular applications of Maytenus rigida for the treatment of inflammation, ulcer and diarrhoea in Brazil herbal traditional medicine.

Maytensifolone, a new triterpene from Maytenus distichophylla Mart. ex Reissek

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Duarte, Marcelo Cavalcante; Tavares, Josean Fechine; Madeiro, Sara Alves L.; Costa, Vicente Carlos O.; Barbosa Filho, Jose Maria; Silva, Marcelo Sobral da, E-mail: marcelosobral.ufpb@gmail.com [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Departamento de Ciencias Farmaceuticas; Agra, Maria de Fatima [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Centro de Biotecnologia. Departamento de Biotecnologia; Braz Filho, Raimundo [Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ (Brazil). Lab. de Ciencias Quimicas

2013-10-15

Phytochemical study of the leaves of Maytenus distichophylla Mart. ex Reissek led to the isolation of the new triterpene 3,16,21-trioxo-6{beta},12{alpha}-dihydroxy-1-en-friedelane, named maytensifolone, along with the known triterpenes 3-oxofriedelane, 3,12-dioxofriedelane, 3{beta}-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 3-oxo-12{alpha}-hydroxyfriedelane and 3-oxo- 30-hydroxyfriedelane. Their structural identification was based on spectroscopic methods and comparison with literature data. (author)

Isolation and antitrichomonal activity of the chemical constituents of the leaves of Maytenus phyllanthoides Benth. (Celastraceae

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Juan Alberto Moo-Puc

2014-01-01

Full Text Available Cyclolignan (+-lyoniresinol (1, veratric acid (2, vanillic acid (3, lupeol, oleanolic acid, 3β-hydroxy-urs-11-en-28,13β-lactone (4, the mixture of α- and β-amyrin, trans-polyisoprene, and β-sitosterol were isolated from the leaves of Maytenus phyllanthoides. The structures of the isolated compounds were established based on spectroscopic data, mainly ¹H and 13C nuclear magnetic resonance (NMR. Compound 1, its acetate analog 1a, and compounds 2, 3, and 4 were tested against Trichomonas vaginalis. (+-Lyoniresinol showed activity corresponding to IC50 17.57 µM. This is the first report on the occurrence of 3β-hydroxy-urs-11-en-28,13β-lactone (4 in the Celastraceous family and lyoniresinol in the Maytenus genus, and on the antitrichomonal activity of lyoniresinol.

Isolation and antitrichomonal activity of the chemical constituents of the leaves of Maytenus phyllanthoides Benth. (Celastraceae)

International Nuclear Information System (INIS)

Moo-Puc, Juan Alberto; Martin-Quintal, Zhelmy; Miron-Lopez, Gumersindo; Mena-Rejon, Gonzalo J.; Moo-Puc, Rosa Esther; Quijano, Leovigildo

2014-01-01

Cyclolignan (+)-lyoniresinol (1), veratric acid (2), vanillic acid (3), lupeol, oleanolic acid, 3β-hydroxy-urs-11-en-28,13β-lactone (4), the mixture of α- and β-amyrin, trans-polyisoprene, and β-sitosterol were isolated from the leaves of Maytenus phyllanthoides. The structures of the isolated compounds were established based on spectroscopic data, mainly 1 H and 13 C nuclear magnetic resonance (NMR). Compound 1, its acetate analog 1a, and compounds 2, 3, and 4 were tested against Trichomonas vaginalis. (+)-Lyoniresinol showed activity corresponding to IC 50 17.57 μM. This is the first report on the occurrence of 3β-hydroxy-urs-11-en-28,13β-lactone (4) in the Celastraceous family and lyoniresinol in the Maytenus genus, and on the antitrichomonal activity of lyoniresinol. (author)

Isolation and antitrichomonal activity of the chemical constituents of the leaves of Maytenus phyllanthoides Benth. (Celastraceae)

Energy Technology Data Exchange (ETDEWEB)

Moo-Puc, Juan Alberto; Martin-Quintal, Zhelmy; Miron-Lopez, Gumersindo; Mena-Rejon, Gonzalo J., E-mail: mrejon@uady.mx [Laboratorio de Quimica Farmaceutica. Facultad de Quimica. Universidad Autonoma de Yucatan (Mexico); Moo-Puc, Rosa Esther [Unidad de Investigacion Medica Yucatan, Instituto Mexicano del Seguro Social, Yucatan (Mexico); Quijano, Leovigildo [Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Coyoacan (Mexico)

2014-07-01

Cyclolignan (+)-lyoniresinol (1), veratric acid (2), vanillic acid (3), lupeol, oleanolic acid, 3β-hydroxy-urs-11-en-28,13β-lactone (4), the mixture of α- and β-amyrin, trans-polyisoprene, and β-sitosterol were isolated from the leaves of Maytenus phyllanthoides. The structures of the isolated compounds were established based on spectroscopic data, mainly {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR). Compound 1, its acetate analog 1a, and compounds 2, 3, and 4 were tested against Trichomonas vaginalis. (+)-Lyoniresinol showed activity corresponding to IC{sub 50} 17.57 μM. This is the first report on the occurrence of 3β-hydroxy-urs-11-en-28,13β-lactone (4) in the Celastraceous family and lyoniresinol in the Maytenus genus, and on the antitrichomonal activity of lyoniresinol. (author)

Effect of X- and gamma-rays on phenolic compounds from Maytenus aquifolium Martius

International Nuclear Information System (INIS)

Campos, P.; Yariwake, J.H.; Lancas, F.M.

2005-01-01

The effect of irradiation using several doses of X- and γ-rays (10, 20, 40, 60, 80 and 100 kGy), upon total phenolic compounds contained in the leaves of Maytenus aquifolium Martius (Celastraceae) 'espinheira santa', was investigated. The content of phenolic compounds (measured by the Folin-Denis spectrophotometric method) was unaffected by X- or γ-ray irradiation, at any dose. (author)

Pharmacological potential of Maytenus species and isolated constituents, especially tingenone, for treatment of painful inflammatory diseases

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Clarice C. Veloso

Full Text Available ABSTRACT Uses of medicinal plants by people around the world significantly contribute and guide biologically active compounds research that can be useful in the combat against various diseases. Due to a great chemical and structural variety found in their vegetal structures it consolidates ethnopharmacology as an important science for the pharmaceutical section. Inserted in the diversity of medicinal plants, is the Maytenus genus, whose research has already revealed lots of isolated substances which are responsible for a great variety of biological activities, among which we cite analgesic and anti-inflammatory, for the treatment of inflammatory diseases such as rheumatoid arthritis, gastritis, ulcers and gastrointestinal disorders. The aim of this review article is to make a compendium of the Maytenus genus and its isolated chemical compounds, among them tingenone. The elucidation of its mechanism of action reveals promising sources for the development of new drugs specially targeted for the treatment of painful inflammatory diseases.

Perfil fitoquímico e ensaio microbiológico dos extratos da entrecasca de Maytenus rigida Mart. (Celastraceae

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Charles S. Estevam

Full Text Available Maytenus rigida Mart (Celastraceae, conhecida por "Bom-homem", "Bom-nome", "Cabelo-de-negro", "Casca-grossa" e "Pau-de-colher", é uma arvore de pequeno porte. A entrecasca do caule é empregada popularmente no Nordeste do Brasil no tratamento das dores em geral, infecções e inflamações. O presente trabalho avaliou tanto o perfil fitoquímico de M. rigida por meio de um roteiro analítico, quanto à atividade antibiótica dos extratos pelo método de Kirby-Bauer modificado. Os resultados demonstraram que os extratos etanólico, aquoso, clorofórmico, acetato de etila e hidroalcoólico de M. rigida apresentam atividade antibacteriana contra Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus, enquanto que a fração hexânica não exibe qualquer atividade. Catequinas, quinonas, esteróides, triterpenos, saponinas, flavonóides e compostos fenólicos foram detectados na análise fitoquímica.

Antioxidant, cytotoxic and UVB-absorbing activity of Maytenus guyanensis Klotzch. (Celastraceae) bark extracts

OpenAIRE

Macari,Patrícia de Almeida Telles; Portela,Cíntia Nicácio; Pohlit,Adrian Martin

2006-01-01

Maytenus guyanensis Klotzch. is an Amazonian medicinal tree species known in Brazil by the common name chichuá and in Peru and Colombia by the name chuchuhuasi. It is used in traditional medicine as stimulant, tonic, and muscle relaxant, for the relief of arthritis, rheumatism, hemorrhoids, swollen kidney, skin eruptions, and skin cancer prevention, among others. Initially, different extraction solvents and methods were applied to dried, ground bark which made possible the preparation of extr...

Genetic diversity in populations of Maytenus dasyclada (Celastraceae in forest reserves and unprotected Araucaria forest remnants

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Manuel Castilhos Reichmann

Full Text Available ABSTRACT Understanding the genetic structure and diversity of plants is fundamental to their conservation and permits their sustainable use by local communities. The genus Maytenus (Celastraceae is composed of plants possessing pharmacological and antioxidant properties. However, the genetic and economic properties of the species M. dasyclada, a typical species of Araucaria forests in Brazil and Uruguay, have been little studied. In this work, the genetic structure and diversity of natural populations of M. dasyclada located in unprotected and preserved forest remnants were investigated using RAPD and isozymes markers. The results demonstrated that in areas of preservation, populations of M. dasyclada possess a relatively high degree of polymorphism and high values for Na, Ne, Shannon index, He and Ho, indicating high genetic variability. Moreover, these protected populations are very close to each other and potentially experience significant gene flow. The results presented here highlight the relevance of preservation areas for the conservation of M. dasyclada, and that populations inhabiting these areas could serve as a genetic source for the recovery of populations in regions where genetic diversity has been lost.

Flora arbórea da bacia do rio Tibagi (Paraná, Brasil: Celastrales sensu Cronquist Tree flora of the Tibagi river basin (Paraná, Brazil: Celastrales sensu Cronquist

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Ricardo Augusto Gorne Viani

2007-06-01

Full Text Available Este trabalho estudou, por meio de coleções de herbários, os representantes arbóreos da ordem Celastrales sensu Cronquist, encontrados na bacia do rio Tibagi, estado do Paraná, Brasil. Esta bacia hidrográfica, subdividida em três zonas de norte para sul, baixo Tibagi (BT, médio Tibagi (MT e alto Tibagi (AT, apresenta diferentes condições ambientais e tipos de vegetação ao longo de sua extensão. A ordem Celastrales está representada na bacia estudada por 15 espécies arbóreas, pertencentes às famílias Aquifoliaceae, Celastraceae e Icacinaceae. Icacinaceae conta com apenas duas espécies, Citronella gongonha e C. paniculata, sendo a primeira distinta pelo ovário glabro e folhas geralmente com espinhos. Aquifoliaceae contém seis espécies: Ilex brasiliensis, I. brevicuspis, I. chamaedryfolia, I. dumosa, I. paraguariensis e I. theezans, que ocorrem preferencialmente no AT e MT e se distinguem pela dimensão, revestimento, ápice e margem da folha e pela morfologia das sépalas. Celastraceae está representada por sete espécies pertencentes a dois gêneros, Plenckia populnea, espécie de cerrado, encontrada apenas no MT e seis espécies de Maytenus (M. aquifolia, M. dasyclada, M. evonymoides, M. ilicifolia, M. robusta e M. salicifolia, com distinção baseada principalmente no tipo de margem e dimensão das folhas, forma do ramo e número de flores por inflorescência.A study of the tree species of the order Celastrales sensu Cronquist from the Tibagi river basin, Paraná state, Brazil, is presented, based on herbarium material. This basin is subdivided into three zones, from north to south: lower Tibagi (BT, mid Tibagi (MT and upper Tibagi (AT, each with different environmental conditions and vegetation types. The order Celastrales is represented in the basin by 15 tree species belonging to three families: Aquifoliaceae, Celastraceae and Icacinaceae. Icacinaceae has only two species, Citronella gongonha and C. paniculata. The

Avaliação da atividade antimicrobiana de Maytenus rigida Mart. (Celastraceae Evaluation of the antimicrobial activity of Maytenus rigida Mart. (Celastraceae

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V.L Santos

2011-01-01

Full Text Available A realização de estudos farmacológicos é fundamental para comprovar a eficácia do uso de plantas medicinais pela população para o tratamento de doenças e descobrir novos fitoterápicos. Esse estudo teve como objetivo avaliar o potencial antimicrobiano do extrato etanólico e fase acetato de etila do bom nome (Maytenus rigida Mart. sobre Staphylococcus aureus ATCC 25923, 3 amostras de Staphylococcus aureus multirresistentes isoladas de pacientes com infecções nosocomiais, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 e Salmonella sp. (228-R-Tet, 118-R-Sut e 01-S isoladas de ambiente aquático, utilizando o método de difusão em agar. Os testes revelaram que o extrato e fase de M. rigida apresentaram atividade antimicrobiana in vitro frente a todas as cepas de S. aureus testadas, apresentando concentração inibitória mínima (MIC de 400 mg mL-1. Entretanto, estes produtos não apresentaram atividade frente às linhagens de bactérias Gram-negativas testadas, Escherichia coli, Pseudomonas aeruginosa e Salmonella sp.Ppharmacological studies are essential to prove the effectiveness of using medicinal plants to treat diseases and discover new phytotherapics. This study aimed to evaluate the antimicrobial potential of ethanol and ethyl acetate extracts of "bom-nome" (Maytenus rigida Mart. against Staphylococcus aureus ATCC 25923, three samples of multiresistant Staphylococcus aureus isolated from patients with nosocomial infections, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Salmonella sp. (228-R-Tet, 118-R-Sut and 01-S isolated from water environment, using the agar diffusion test. Both extracts showed in vitro antimicrobial activity against all S. aureus strains, presenting 400 mg mL-1 minimum inhibitory concentration (MIC. However, these products did not show activity against strains of the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa and Salmonella sp.

Utilization of labelled urea in Helicobacter pylori eradication study by Espinheira Santa

International Nuclear Information System (INIS)

Chausson, Yvon; Coelho, Luiz Gonzaga Vaz; Passos, Maria do Carmo Friche; Andrade, Angela Almeida Magalhaes; Paiva Leriza, Duilio de; Paula Castro, Luiz de

1995-01-01

Maytenus ilicifolia, Espinheira Santa, is usually used to treat some gastric diseases, in special duodenal ulcer, in agreement with the medical literature. The aim of this work was to verify the efficiency of those leaves in such disease. It was selected a group of volunteers with ulcer caused by Helicobacter pylori (Hp) confirmed by Urea Breath Test (UBT). It was administered to all patients one capsule having 300 mg of dry extract of the leaves 20 minutes before the UBT. The capsule went on being administered during a week three times a day. At the end of this period two tests were applied to evaluate the Hp eradication: one 12 hours just after the treatment and another after one month. The results indicated that the antibiotic action was not confirmed. (author). 4 refs., 1 fig

Determination of metals in medicinal plants highly consumed in Brazil

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Alexandre Soares Leal

2013-09-01

Full Text Available In this work, samples of the medicinal plants: Boldo (Peumus boldus, Castanha da Índia (Aesculus hippocastanum, Chá Verde (Camelia sinensis, Erva Cidreira (Melissa officinalis, Espinheira Santa (Maytenus ilicifolia, Guaraná (Paullinia cupana, Maracujá (Passiflora sp., Mulungu (Erythrina velutina, Sene (Cassia angustifolia and Valeriana (Valeriana officinalis were evaluated BY using the Neutron Activation Analysis technique (NAA- k0 in order to determine the levels of metals and other chemical contaminants. The results showed the presence of non essential elements to the human body. The diversity of chemical impurities found even at low concentration levels, considering the potential for chronic toxicity of these elements, reinforces the need to improve the implementation of good practices by growers and traders, and the hypothesis of lack of quality control in plant products.

Persistência de plantas medicinais em sistemas agroflorestais no município de São Bento do Sul, SC, Brasil

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A.L. Hanisch

2013-01-01

Full Text Available No final da década de 90, a comunidade de Rio Natal, no município de São Bento do Sul, SC, passou a fazer parte de uma Área de Preservação Ambiental e desde então, muitas áreas de cultivo, paulatinamente, estão retomando o processo de formação florestal. Neste cenário, foi sugerido pela comunidade, a possibilidade de cultivo de plantas medicinais adaptadas às condições de sombreamento. Em atendimento a essa demanda foi realizada uma pesquisa participativa na comunidade, de 2005 a 2008, onde foram avaliadas 14 espécies de plantas medicinais com potencial de mercado, cultivadas em áreas sombreadas, em três propriedades familiares. Foram avaliados: taxa de sobrevivência das espécies, incidência de doenças e pragas, teor de massa seca e altura das plantas. Apresentaram persistência ao cultivo em áreas sombreadas as espécies: Curcuma longa L. (açafrão-da-índia; Arctium lappa L. (bardana; Pfaffia glomerata (Spreng Pedersen (fáfia ou ginseng-brasileiro; Mikania glomerata Sprengel (guaco; Alternanthera brasiliana L. Kuntze (penicilina; Pogostemon cablin (Blanco Benth (patchuli e Maytenus ilicifolia Mart. Ex Reissek (espinheira-santa.

Evaluación de la actividad hipotensora del Maytenus Krukovii (Chuchuhuasi) en rata consciente.

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Salazar Granara, Alberto; Milla Flores, Diana Rosa; Morales Gutiérrez, Valeria; Velarde Barrantes, Luis Fernando; Villanueva Espinoza, Alan Alexis; Segura Carrillo, Karla; Casquero Del Castillo, Diego; Vargas Pareja, Yisella; Vela Gonzáles, Yliana; Sánchez Alarcón, Vanessa; Manrique Mejia, Renán

2008-01-01

Maytenus krukovii (chuchuhuasi), oriunda de la amazonia sudamericana, tradicionalmente se le atribuye acción analgésica, antiinflamatoria, afrodisíaca entre otros; investigaciones reportan acción analgésica con intermediación de receptores opiáceos, efecto antipirético, antiinflamatorio y gastroprotector. El presente estudio experimental indagó acerca de la acción sobre la presión arterial y frecuencia cardiaca del chuchuhuasi en rata consciente. Se utilizaron 10 ratas albinas machos, a las q...

Screening of the in vitro antileishmanial activities of compounds and secondary metabolites isolated from Maytenus guianensis Klotzsch ex Reissek (Celastraceae) chichuá Amazon.

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Meneguetti, Dionatas Ulises de Oliveira; Lima, Renato Abreu; Hurtado, Fernanda Bay; Passarini, Guilherme Matos; Macedo, Sharon Rose Aragão; Barros, Neuza Biguinati de; Oliveira, Flávio Augusto de Souza; Medeiros, Patrícia Soares de Maria de; Militão, Júlio Sancho Linhares Teixeira; Nicolete, Roberto; Facundo, Valdir Alves

2016-01-01

Maytenus guianensis is a member of the Celastraceae family that is used in traditional medicine, particularly for its anti-parasitic and anti-cancer effects. To explore the ethnopharmacological potential of this plant, the present study was designed to screen the in vitro antileishmanial activities of extracts and compounds isolated from M. guianensis. Maytenus guianensis stems and leaves were extracted in acetone, followed by the preparation of eluates and isolation of secondary metabolites using chromatography on a glass column with silica gel as the fixed phase. The chemical components were identified using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance of hydrogen-1 and carbon-13, mass spectroscopy, and infrared spectroscopy. The anti-Leishmania amazonensis activities of these eluates and compounds were evaluated by direct promastigote counting and viability assays. It was found that the hexane bark eluate produced the strongest anti-L. amazonensis effect, with 90-100% inhibition of the promastigote form. The isolated metabolite that produced the best result was tingenone B, followed by a compound formed by the union of tingenone and tingenone B (80-90% inhibition). Maytenus guianensis shows anti-parasite activity that warrants further investigation to determine the mechanisms underlying this antileishmanial effect and to evaluate the pharmacological potential of these eluates and isolated secondary metabolites, while minimizing any adverse effects.

Screening of the in vitro antileishmanial activities of compounds and secondary metabolites isolated from Maytenus guianensis Klotzsch ex Reissek (Celastraceae chichuá Amazon

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Dionatas Ulises de Oliveira Meneguetti

Full Text Available Abstract INTRODUCTION Maytenus guianensis is a member of the Celastraceae family that is used in traditional medicine, particularly for its anti-parasitic and anti-cancer effects. To explore the ethnopharmacological potential of this plant, the present study was designed to screen the in vitro antileishmanial activities of extracts and compounds isolated from M. guianensis. METHODS Maytenus guianensis stems and leaves were extracted in acetone, followed by the preparation of eluates and isolation of secondary metabolites using chromatography on a glass column with silica gel as the fixed phase. The chemical components were identified using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance of hydrogen-1 and carbon-13, mass spectroscopy, and infrared spectroscopy. The anti-Leishmania amazonensis activities of these eluates and compounds were evaluated by direct promastigote counting and viability assays. RESULTS It was found that the hexane bark eluate produced the strongest anti-L. amazonensis effect, with 90-100% inhibition of the promastigote form. The isolated metabolite that produced the best result was tingenone B, followed by a compound formed by the union of tingenone and tingenone B (80-90% inhibition. CONCLUSIONS Maytenus guianensis shows anti-parasite activity that warrants further investigation to determine the mechanisms underlying this antileishmanial effect and to evaluate the pharmacological potential of these eluates and isolated secondary metabolites, while minimizing any adverse effects.

Chemical constituents from branches of Maytenus gonoclada (Celastraceae) and evaluation of antimicrobial activity

International Nuclear Information System (INIS)

Silva, Fernando C.; Duarte, Lucienir P.; Silva, Gracia D.F.; Vieira Filho, Sidney A.; Lula, Ivana S.; Takahashi, Jacqueline A.; Sallum, William S.T.

2011-01-01

Six pentacyclic triterpenes were isolated from branches of Maytenus gonoclada (Celastraceae) and all NMR data of a new compound 3-oxo-12α,29-dihydroxyfriedelane are herein reported. The stereochemistry of the new friedelane was established by bidimensional NMR (HSQC, HMBC and NOESY) data, and its molecular weight confirmed by ESI mass spectrometry. Antimicrobial activity assays using the method of disk diffusion and macrodilution were carried out against the bacteria Escherichia coli, Citrobacter freundii, and Bacillus cereus, and against the fungi Candida albicans. The triterpene 3-oxo-12α-hydroxyfriedelane showed positive result against C. albicans. (author)

Dihydroagarofuranoid Sesquiterpenes as Acetylcholinesterase Inhibitors from Celastraceae Plants: Maytenus disticha and Euonymus japonicus.

Science.gov (United States)

Alarcón, Julio; Cespedes, Carlos L; Muñoz, Evelyn; Balbontin, Cristian; Valdes, Francisco; Gutierrez, Margarita; Astudillo, Luis; Seigler, David S

2015-12-02

Natural cholinesterase inhibitors have been found in many biological sources. Nine compounds with agarofuran (epoxyeudesmane) skeletons were isolated from seeds and aerial parts of Maytenus disticha and Euonymus japonicus. The identification and structural elucidation of compounds were based on spectroscopic data analyses. All compounds had inhibitory acetylcholinesterase (AChE) activity. These natural compounds, which possessed mixed or uncompetitive mechanisms of inhibitory activity against AChE, may be considered as models for the design and development of new naturally occurring drugs for management strategies for neurodegenerative diseases. This is the first report of these chemical structures for seeds of M. disticha.

Chemical constituents from branches of Maytenus gonoclada (Celastraceae) and evaluation of antimicrobial activity

Energy Technology Data Exchange (ETDEWEB)

Silva, Fernando C.; Duarte, Lucienir P.; Silva, Gracia D.F.; Vieira Filho, Sidney A.; Lula, Ivana S., E-mail: lucienir@ufmg.b [Universidade Federal de Minas Gerais (DQ/UFMG), Belo Horizonte (Brazil). Dept. de Quimica. Nucleo de Estudos de Plantas Medicinais; Takahashi, Jacqueline A.; Sallum, William S.T. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil). Escola de Farmacia

2011-07-01

Six pentacyclic triterpenes were isolated from branches of Maytenus gonoclada (Celastraceae) and all NMR data of a new compound 3-oxo-12{alpha},29-dihydroxyfriedelane are herein reported. The stereochemistry of the new friedelane was established by bidimensional NMR (HSQC, HMBC and NOESY) data, and its molecular weight confirmed by ESI mass spectrometry. Antimicrobial activity assays using the method of disk diffusion and macrodilution were carried out against the bacteria Escherichia coli, Citrobacter freundii, and Bacillus cereus, and against the fungi Candida albicans. The triterpene 3-oxo-12{alpha}-hydroxyfriedelane showed positive result against C. albicans. (author)

EFECTO DIURÉTICO DE LAS HOJAS DE MAYTENUS MACROCARPA “CHUCHUHUASI” EN RATAS ALBINAS

OpenAIRE

Fanny Bastidas Garcia; Juan Jesús Huaccho Rojas; Javier Chambi Torres; Antonio Padilla Alexander; Luis Aguirre Tipismana; Alberto Salazar Granara; Benjamín Castañeda Castañeda

2016-01-01

Objetivo: Evaluar la actividad diurética del extracto acuoso obtenido a partir de la hojas del Maytenus macrocarpa “Chuchuhuasi” en ratas albinas. Material y Métodos: Se utilizaron 68 ratas albinas machos, con pesos medios de 250 g, se empleó el Método de Lipschitz, donde se registró el volumen de orina por hora y total a la sexta hora. Los grupos experimentales fueron: Control (suero fisiológico al 0.9%), chuchuhuasi 1 (250mg/kg), chuchuhuasi 2 (500mg/kg), chuchuhuasi 3 (750mg/kg), hojas de ...

Evaluation of the toxicity and antiulcerogenic activity of the ethanol extract of Maytenus obtusifolia Mart. leaves

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Kelly Samara de Lira Mota

Full Text Available Maytenus obtusifolia is used in folk medicine for the treatment of serious ulcers, general inflammations and cancer. Despite of the ethnopharmacological importance of this species, no study was conducted to evaluate its toxicity and antiulcerogenic activity. In this study, we evaluated the toxicity and antiulcerogenic property of the ethanol extract of the leaves of Maytenus obtusifolia (MO-EtOH. The MO-EtOH (10-1000 µg/mL showed low toxicity for larvae of A. salina with LC50 higher than 1000 µg/mL. The MO-EtOH (2000 mg/kg, p.o. did not change the body and organs weight of the mice, but it was observed an increase in the water consumption of males and a decrease in the food consumption of females. During the study no deaths and no macroscopic changes in the organs were observed in the mice. MO-EtOH (62.5, 125, 250 and 500 mg/kg and lansoprazole (30 mg/kg significantly reduced the ulcerative index for 65.58 ± 8.74, 43.00 ± 9.53, 15.50 ± 7.56, 54.75 ± 8.88 and 36.13 ± 9.55, respectively, in comparison with saline 82.13 ± 12.48. In conclusion, the MO-EtOH showed low toxicity and antiulcerogenic activity, confirming the popular use of M. obtusifolia.

EFECTO DIURÉTICO DE LAS HOJAS DE MAYTENUS MACROCARPA “CHUCHUHUASI” EN RATAS ALBINAS

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Fanny Bastidas Garcia

2016-07-01

Full Text Available Objetivo: Evaluar la actividad diurética del extracto acuoso obtenido a partir de la hojas del Maytenus macrocarpa “Chuchuhuasi” en ratas albinas. Material y Métodos: Se utilizaron 68 ratas albinas machos, con pesos medios de 250 g, se empleó el Método de Lipschitz, donde se registró el volumen de orina por hora y total a la sexta hora. Los grupos experimentales fueron: Control (suero fisiológico al 0.9%, chuchuhuasi 1 (250mg/kg, chuchuhuasi 2 (500mg/kg, chuchuhuasi 3 (750mg/kg, hojas de chuchuhuasi 4 (1000mg/kg, furosemida 1 (10mg/kg y furosemida 2 (20mg/kg. Para la validación estadística se usó la prueba de Shapiro-Wilk, Tukey y Dunns. Resultados: El mayor volumen total obtenido durante las primeras 24 horas fue de 5,17ml para chuchuhuasi de 1000 mg/kg, llegando a tener inclusive mayor valor que la furosemida de 20 mg/kg. Por otro lado el grupo de chuchuhuasi de 250 mg/kg (2.32 obtuvo  menor acción diurética que el grupo control (2.55 ml. El test de Tukey no indicó diferencias significativas. Sin embargo, en el análisis bioquímico el test de Xi cuadrado tuvo un p< 0.05 para el PH. Conclusión: Se demuestra una respuesta diurética positiva en todos los niveles de dosis ensayadas del extracto etanólico de Maytenus macrocarpa: 250, 500, 750 y un mayor efecto 1000 mg/kg de peso, al compararlos con el grupo control y la Furosemida. Palabras Clave: Diuresis, Furosemida, Medicina Tradicional, Etnofarmacología.

Avaliação do fator de proteção solar em fotoprotetores acrescidos com extratos da flora brasileira ricos em substâncias fenólicas

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Vanessa Marquito Munhoz

2012-04-01

Full Text Available Sabe-se que o número de casos de câncer de pele tem crescido muito nos últimos anos. Com isso, novos produtos são constantemente desenvolvidos no intuito de aumentar a gama de substâncias para proteção solar. O principal objetivo desse trabalho foi a análise in vitro da propriedade fotoprotetora de uma formulação contendo filtros solares químicos, adicionada de extratos brutos de Guazuma ulmifolia, Maytenus ilicifolia, Stryphnodendron adstringens e Trichilia catigua, respectivamente, e a avaliação quanto ao acréscimo do Fator de Proteção Solar (FPS. O ensaio foi conduzido pelo método espectrofotométrico in vitro do Fator de Proteção Solar (FPS. O teor de Polifenóis Totais (PT e sua correlação com a Capacidade Antioxidante (CA dos extratos avaliados foram realizados. Os resultados demonstram que as formulações foram estáveis após a adição dos extratos, quanto a características físicoquímicas (características macroscópicas, ensaio de centrifugação e pH quando comparadas ao controle. O ensaio de FPS in vitro demonstrou decaimento do FPS das formulações acrescidas de extratos vegetais ricas em compostos fenólicos, exceto para o extrato de S. adstringens. Os FPS obtidos para os extratos foram ≤2. O teor em PT foram (%: G. ulmifolia, 24,26±0,34; M. ilicifolia, 14,66±0,18; S. adstringens, 34,38±0,62 e T. catigua, 41,60±0,13. Os valores da CA (IC50 frente ao radical DPPH foram (μg/mL: vitamina C (7,52±0,12, G. ulmifolia (8,94±0,13, M. ilicifolia (38,41±0,93, S. adstringens (7,31±0,15 e T. catigua (5,48±0,04. A CA foi diretamente proporcional ao teor de PT.

Behavior of triterpenes from Maytenus aquifolium Martius ('espinheira santa') upon X- and gamma-rays irradiation

International Nuclear Information System (INIS)

Campos, P.; Vilegas, J.H.Y.; Lancas, F.M.

1997-01-01

The behavior of the triterpenes friedelin and friedelan-3-ol, contained on the leaves of Maytenus aquifolium Martius (Celastraceae), upon several doses of X- and γ-rays (10 to 100 kGy), was investigated by high resolution gas chromatography (HRGC) and high resolution gas chromatography -mass spectrometry (HRGC-MS). The friedelin content has not changed with γ-irradiation, but the content of friedelan-3-ol decreased around 17% at doses of 10, 20 and 40 kGy and around 27% at doses of 60, 80 and 100 kGy. The levels of both triterpenes remained unchanged even at higher X-ray doses. Lupen-3-one was detected by HRGC-MS. (author)

Systematic review and gamma radiosensitivity of medicinal plants: development of protocol for quality control

International Nuclear Information System (INIS)

Oliveira, Ralph Santos

2006-01-01

The present study discusses the contribution of the adoption of more rigorous and objective criteria to the selection and analysis of information sources, leading to more scientific rigour when registering phytotherapic drugs. To this end, it is herein proposed the adoption of a previously tested and acknowledged methodology, namely the Systematic Revision, as a standard for phytotherapic drug analyses. In order to show differences brought about by the Systematic Revision during the registration procedures of phytotherapic drugs, the case of the Maytenus ilicifolia (known popularly in Brazil as 'espinheira-santa') is presented. As it is well known, the use of ionizing radiation is expanding, especially in medicine and pharmacy. Therefore, gamma radiation was applied to the microbiological quality control of phytotherapic matrices. Results indicated a positive contribution of Systematic Revision to the registration procedures of phytotherapic drugs, as well as the advantages of using gamma radiation to the microbiological quality control of phytotherapic matrices. (author)

Systematic review and gamma radiosensitivity of medicinal plants: development of protocol for quality control; Revisao sistematica e radiossensitividade gama de plantas medicinais: desenvolvimento de protocolo para controle de qualidade

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Ralph Santos

2006-07-01

The present study discusses the contribution of the adoption of more rigorous and objective criteria to the selection and analysis of information sources, leading to more scientific rigour when registering phytotherapic drugs. To this end, it is herein proposed the adoption of a previously tested and acknowledged methodology, namely the Systematic Revision, as a standard for phytotherapic drug analyses. In order to show differences brought about by the Systematic Revision during the registration procedures of phytotherapic drugs, the case of the Maytenus ilicifolia (known popularly in Brazil as 'espinheira-santa') is presented. As it is well known, the use of ionizing radiation is expanding, especially in medicine and pharmacy. Therefore, gamma radiation was applied to the microbiological quality control of phytotherapic matrices. Results indicated a positive contribution of Systematic Revision to the registration procedures of phytotherapic drugs, as well as the advantages of using gamma radiation to the microbiological quality control of phytotherapic matrices. (author)

Antiproliferative activity of pristimerin isolated from Maytenus ilicifolia (Celastraceae) in human HL-60 cells.

Science.gov (United States)

Costa, Patricia Marçal da; Ferreira, Paulo Michel Pinheiro; Bolzani, Vanderlan da Silva; Furlan, Maysa; de Freitas Formenton Macedo Dos Santos, Vânia Aparecida; Corsino, Joaquim; de Moraes, Manoel Odorico; Costa-Lotufo, Letícia Veras; Montenegro, Raquel Carvalho; Pessoa, Cláudia

2008-06-01

Pristimerin has been shown to be cytotoxic to several cancer cell lines. In the present work, the cytotoxicity of pristimerin was evaluated in human tumor cell lines and in human peripheral blood mononuclear cells (PBMC). This work also examined the effects of pristimerin (0.4; 0.8 and 1.7 microM) in HL-60 cells, after 6, 12 and 24h of exposure. Pristimerin reduced the number of viable cells and increased number of non-viable cells in a concentration-dependent manner by tripan blue test showing morphological changes consistent with apoptosis. Nevertheless, pristimerin was not selective to cancer cells, since it inhibited PBMC proliferation with an IC50 of 0.88 microM. DNA synthesis inhibition assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation in HL-60 cells was 70% and 83% for the concentrations of 0.4 and 0.8 microM, respectively. Pristimerin (10 and 20 microM) was not able to inhibit topoisomerase I. In AO/EB (acridine orange/ethidium bromide) staining, all tested concentrations reduced the number of HL-60 viable cells, with the occurrence of necrosis and apoptosis in a concentration-dependent manner, results in agreement with trypan blue exclusion findings. The analysis of membrane integrity and internucleosomal DNA fragmentation by flow cytometry in the presence of pristimerin indicated that treated cells underwent apoptosis. The present data point to the importance of pristimerin as representative of an emerging class of potential anticancer chemicals, exhibiting an antiproliferative effect by inhibiting DNA synthesis and triggering apoptosis.

Effect of Maytenus macrocarpa“Chuchuhuasi” in the male system reproductive of mouse (Mus musculus

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Láyonal G. Acosta

2014-03-01

Full Text Available Maytenus macrocarpa(chuchuhuasi is native tree of the Peruvian Amazon used as traditional medicine for the treatment of many diseases, but its effect on the male reproductive system has not yet been elucidated. The aim of this study is evaluate the effect of aqueous extract of M. macrocarpa in daily doses for 7 days on reproductive parameters of male mice. We used C57BL mature male mice divided into 2 groups (n= 10, Control Group (C: 0.9% NaCl and Treatment group (T: Aqueous extract of Chuchuhuasi, both supplied daily via oral gavages. At the eight day of treatment the mice were euthanized. The weight of the body and reproductive organs: testis, epididymis and vas deferens, were registered. Concentration, motility and sperm morphology were evaluated. The results showed significantly differences (t- Student test P<0.05 in the weight of the head and body epididymis (C: 19.25±1.1 vs T: 21.26±2.0, vas deferens (C: 10.61±0.7 vs T: 11.75±0.5, progressive sperm motility (C: 42.16±5.2 vs T: 25.82±8.4 and immobile sperm (C: 36.05±4.9 vs T: 48.51±7.2. No difference in sperm count was observed. The sperm normal morphology diminished with ingest of M. macrocarpa(tStudent test p <0.05 (C: 39.72±1.3 vs T: 30.78±4.9. We conclude that the aqueous extract of chuchuhuasi, has a negative effect on the male reproductive system of mice.

Potential pitfalls in the nuclear medicine imaging: Experimental models to evaluate the effect of natural products on the radiolabeling of blood constituents, bioavailability of radiopharmaceutical and on the survival of Escherichia coli strains submitted to the treatment with stannous ion

International Nuclear Information System (INIS)

Soares, Scheila F.; Brito, Lavinia C.; Souza, Deise E.; Bernardo, Luciana C.; Oliveira, Joelma F.; Bernardo-Filho, Mario

2006-01-01

Single photon emission computed tomography (SPECT) allows studies of physiological or pathological processes. Red blood cells labeled with technetium-99m ( 99m Tc-RBC) are used as a radiopharmaceutical in several evaluations. The radiolabeling efficiency and bioavailability of radiopharmaceuticals can be altered by natural/synthetic drugs and may induce pitfalls in the analysis of the nuclear medicine imaging. The labeling with 99m Tc requires a reducing agent and stannous chloride (SnCl 2 ) is widely utilized. However, SnCl 2 presents a citotoxic and/or genotoxic potential in Escherichia coli (E. coli) strains. The aim of this work was to evaluate the influence of aqueous extracts of Baccharis genistelloides (BG), Terminalia chebula (TC), Maytenus ilicifolia (MI), Cassia angustifolia (CA) and Equisetum arvense (EA) on (i) radiolabeling of blood constituents (ii) bioavailability of sodium pertechnetate(Na 99m TcO 4 ) radiopharmaceutical (iii) survival of E. coli. In vitro labeling of RBC was performed with blood (Wistar rats) incubated with each extract, SnCl 2 and Na 99m TcO 4 . Plasma (P) and blood cells (BC) were isolated, another aliquots precipitated and soluble (SF) and insoluble (IF) fractions isolated and counted. In the bioavailability of Na 99m TcO 4 , Wistar rats were treated (7 days) with aqueous extract or with 0.9%NaCl, the radiopharmaceutical was administered, the animals sacrificed, the organs isolated, weighted and radioactivity counted. To evaluate the effect on the bacterial survival, E. coli was treated with: (a) SnCl 2 ; (b) 0.9% NaCl; (c) vegetal extract; or (d) SnCl 2 and vegetal extract. Radiolabeling efficiency showed a significantly decrease (ANOVA/Tukey post-test, p 99m TcO 4 was altered significantly (unpaired t-student test, p 2 action and this fact can be related to the free radical scavenging properties of the chemical compounds of the extracts. In conclusion these findings could be worthwhile to try to understand and to avoid some

Evaluación de la actividad analgésica central de las hojas de Maytenus macrocarpa (Ruiz & Pav.) Briq. (chuchuhuasi)

OpenAIRE

León Fernández, Angélica; Tupia Céspedes, Lourdes; Turriate Montaldo, Yessica; Maraví Rengifo, Julio; Barrientos Herrera, Alejandro; Urbano Farje, Orlando; Salazar Granara, Alberto Alcibíades

2014-01-01

INTRODUCCIÓN: Maytenus macrocarpa Ruiz & Pav.) Briq (chuchuhuasi), es una planta medicinal peruana, a la cual se le atribuyen efectos: antidisentérico, antidiarreico, analgésico, antiinflamatorio, entre otros. OBJETIVO: explorar la actividad analgésica central de las hojas de M. macrocarpa, en ratones, mediante el modelo de retirada de la cola. MÉTODOS: a 50 ratones albinos (25 g promedio), divididos en 5 grupos, se les administró por la vía oral lo siguiente: M. macrocarpa ...

ATIVIDADE ANTIFÚNGICA DO EXTRATO ETANÓLICO DAS CASCAS DE Maytenus guianensis KLOTZSCH EX REISSEK SOBRE Candida albicans

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Renato Abreu Lima

2016-06-01

Full Text Available O presente trabalho teve como objetivo avaliar a atividade fungicida do extrato etanólico das cascas de Maytenus guianensis sobre Candida albicans in vitro. As cascas coletadas foram devidamente secas e trituradas, sendo submetidas à extração em aparelho de Soxhlet com etanol p.a., sendo posteriormente diluídas com DMSO a 2% e para avaliar o potencial biológico sobre o fungo, utilizou-se à técnica de difusão em ágar em poços na concentração de 1mg.mL-1, concentração esta já definida pela técnica de Menor Concentração Inibitória (MIC realizada. Leveduras de C. albicans foram cultivadas em meio BDA durante 24 horas com a absorbância de turvação. Para o controle negativo, utilizou-se somente o meio BDA; controle positivo foi realizado com emulsificante Kasumin®. O delineamento foi inteiramente casualizado, com três repetições por tratamento. A avaliação consistiu em verificar os halos de inibição de crescimento fúngico, a cada 24 horas, durante cinco dias. Observou-se, que após 120 horas, o extrato etanólico das cascas de M. guianensis apresentou resultados dos halos de inibição sobre C. albicans, na qual os halos de inibição de crescimento foram de 1,52 mm do extrato etanólico, demonstrando maior espectro inibitório, se comparado com o controle negativo que foi de 2,87 mm, enquanto que no controle positivo o halo de inibição foi de 2,11 mm. Os resultados sinalizam o potencial antimicrobiano dessa planta, podendo ser promissoras para estudos de desenvolvimento de novos fármacos. Palavras-chave: Celastraceae, triterpenos, fitoquímica.

Assessment of phytochemicals, antioxidant, anti-lipid peroxidation and anti-hemolytic activity of extract and various fractions of Maytenus royleanus leaves.

Science.gov (United States)

Shabbir, Maria; Khan, Muhammad Rashid; Saeed, Naima

2013-06-22

Maytenus royleanus is traditionally used in gastro-intestinal disorders. The aim of this study was to evaluate the methanol extract of leaves and its derived fractions for various antioxidant assays and for its potential against lipid peroxidation and hemolytic activity. Various parameters including scavenging of free-radicals (DPPH, ABTS, hydroxyl and superoxide radical), hydrogen peroxide scavenging, Fe3+ to Fe2+ reducing capacity, total antioxidant capacity, anti-lipid peroxidation and anti-hemolytic activity were investigated. Methanol extract and its derived fractions were also subjected for chemical constituents. LC-MS was also performed on the methanol extract. Qualitative analysis of methanol extract exhibited the presence of alkaloids, anthraquinones, cardiac glycosides, coumarins, flavonoids, saponins, phlobatannins, tannins and terpenoids. LC-MS chromatogram indicated the composition of diverse compounds including flavonoids, phenolics and phytoestrogens. Methanol extract, its ethyl acetate and n-butanol fractions constituted the highest amount of total phenolic and flavonoid contents and showed a strong correlation coefficient with the IC50 values for the scavenging of DPPH, hydrogen peroxide radicals, superoxide radicals, anti-lipid peroxidation and anti-hemolytic efficacy. Moreover, n-butanol fraction showed the highest scavenging activity for ABTS radicals and for reduction of Fe3+ to Fe2+. Present results suggested the therapeutic potential of Maytenus royleanus leaves, in particular, methanol extract, ethyl acetate and n-butanol fraction as therapeutic agent against free-radical associated damages. The protective potential of the extract and or fraction may be attributed due to the high concentration of phenolic, flavonoid, tannins and terpenoids.

Evaluation of fungal burden of medicinal plants submitted to gamma radiation process after 30 days

International Nuclear Information System (INIS)

Aquino, Simone; Araujo, Michel M.; Villavicencio, A.L.C.H.; Goncalez, Edlayne; Reis, Tatiana A. dos; Correa, Benedito

2007-01-01

Forty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia and Cassia angustifolia), purchased from pharmacies and street market in the five cities of Sao Paulo State, were irradiated using a 60 Co gamma ray source (Gammacell) with a dose of 10.0 kGy, delivered at dose rate of 3.0 kGy/h. Nonirradiated samples were used as controls of fungal isolates. For fungal counts and identification in medicinal plants a serial dilutions from 10 -1 to 10 -6 of the samples were seeded in duplicates and plated using the method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25 deg C. Mycological analysis of control samples revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi. The process of gamma radiation was effective in reducing the number of colony forming units (cfu/g) in all irradiated samples of medicinal plants after 30 days, using the dose of 10.0 kGy and kept of veiled conditions. (author)

Evaluation of fungal burden of medicinal plants submitted to gamma radiation process after 30 days

Energy Technology Data Exchange (ETDEWEB)

Aquino, Simone; Araujo, Michel M.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes]. E-mail: siaq06@hotmail.com; Goncalez, Edlayne; Reis, Tatiana A. dos; Correa, Benedito [Universidade de Sao Paulo, SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia]. E-mail: correabe@usp.br

2007-07-01

Forty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia and Cassia angustifolia), purchased from pharmacies and street market in the five cities of Sao Paulo State, were irradiated using a {sup 60}Co gamma ray source (Gammacell) with a dose of 10.0 kGy, delivered at dose rate of 3.0 kGy/h. Nonirradiated samples were used as controls of fungal isolates. For fungal counts and identification in medicinal plants a serial dilutions from 10{sup -1} to 10{sup -6} of the samples were seeded in duplicates and plated using the method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25 deg C. Mycological analysis of control samples revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi. The process of gamma radiation was effective in reducing the number of colony forming units (cfu/g) in all irradiated samples of medicinal plants after 30 days, using the dose of 10.0 kGy and kept of veiled conditions. (author)

Antimicrobial activity and cytotoxicity of triterpenes isolated from leaves of Maytenus undata (Celastraceae).

Science.gov (United States)

Mokoka, Tsholofelo Abednego; McGaw, Lyndy Joy; Mdee, Ladislaus Kakore; Bagla, Victor Patrick; Iwalewa, Ezekiel Olugbenga; Eloff, Jacobus Nicolaas

2013-05-20

Plants of the genus Maytenus belong to the family Celastraceae and are widely used in folk medicine as anti-tumour, anti-asthmatic, analgesic, anti-inflammatory, antimicrobial and anti-ulcer agents, and as a treatment for stomach problems. The aim of this study was to isolate and identify active compounds with antifungal activity from Maytenus undata after a preliminary study highlighted promising activity in crude extracts. Sequential extracts of M. undata leaves prepared using hexane, dichloromethane (DCM), acetone and methanol (MeOH) were tested for activity against Cryptococcus neoformans, a fungal organism implicated in opportunistic infections. Bioassay-guided fractionation of the hexane extract using C. neoformans as test organism was carried out to isolate antifungal compounds. The cytotoxicity of compounds isolated in sufficient quantities was evaluated using a tetrazolium-based colorimetric cellular assay (MTT) and a haemagglutination assay (HA). The hexane extract was most active with an MIC of 20 μg/ml against C. neoformans. The triterpene compounds friedelin (1), epifriedelanol (2), taraxerol (3), 3-oxo-11α-methoxyolean-12-ene-30-oic acid (4), 3-oxo-11α-hydroxyolean-12-ene-30-oic acid (5) and 3,11-dihydroxyolean-12-ene-30-oic acid (6) were isolated. Compound 6 was isolated for the first time from a plant species. The antimicrobial activity of compounds 1, 3, 5 and 6 was determined against a range of bacteria and fungi implicated in opportunistic and nosocomial infections. Compounds 5 and 6 were the most active against all the tested microorganisms with MIC values ranging between 24 and 63 μg/ml, except against Staphylococcus aureus which was relatively resistant. Compounds 1 and 3 had a low toxicity with an LC50 > 200 μg/ml towards Vero cells in the MTT assay. Compounds 5 and 6 were toxic with LC50 values of 6.03±0.02 and 2.98±0.01 μg/ml, respectively. Compounds 1 and 3 similarly were not toxic to the red blood cells (RBCs) but compounds 5 and

EFECTO ANTINOCICEPTIVO DEL EXTRACTO ETANÓLICO DE LAS HOJAS DE MAYTENUS MACROCARPA (RUIZ & PAV. BRIQ. “CHUCHUHUASI” MEDIANTE LA PRUEBA DE CONTORSIONES ABDOMINALES EN RATONES.

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V Robles-Pizarro

2014-01-01

Full Text Available ABSTRACT Objective: To determine the effect and antinociceptive activity of the leaves of Maytenus macrocarpa (Ruiz & Pav Briq . “Chuchuhuasi “ by the writhing test in rodents. Material and Methods: 40 male albino mice were used, with average weights of 25g , the writhing test was used to determine the antinociceptive activity . The experimental groups were: Control; received no substance, ethanol extract of the leaves of M. macrocarpa Briq (Ruiz & Pav. 2000 mg/kg, Tramadol 10 mg/kg and 10mg Sodium Diclofenac /kg. The substances were administered orally one hour before the induction of pain. For statistical validation the Shapiro -Wilk test, one-tailed ANOVA, Tukey, and Newman -Keuls was used. Results: Writhing number was 41 +/- 3.04, 27 +/- 3.55, 9 +/- 4.14, and 18 +/- 2.65 respectively. The inhibition percentage of the nociceptive behavior was: 0%, 34%, 77% and 55%. The test of one-way ANOVA showed statistical differences (p < 0.05, 95% CI, and the Tukey and Newman-Keuls test showed significant differences between groups versus control. Conclusion: Antinociceptive effect of the leaves of Maytenus macrocarpa (Ruiz & Pav. Briq “Chuchuhuasi “ was found at doses of 2000 mg/kg. (Horiz Med 2013; 13(4: 6-10

Antioxidant, cytotoxic and UVB-absorbing activity of Maytenus guyanensis Klotzch. (Celastraceae bark extracts Atividade antioxidante, citotóxica e absorção no UVB de extratos da casca de Maytenus guyanensis Klotzch. (Celastraceae

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Patrícia de Almeida Telles Macari

2006-12-01

Full Text Available Maytenus guyanensis Klotzch. is an Amazonian medicinal tree species known in Brazil by the common name chichuá and in Peru and Colombia by the name chuchuhuasi. It is used in traditional medicine as stimulant, tonic, and muscle relaxant, for the relief of arthritis, rheumatism, hemorrhoids, swollen kidney, skin eruptions, and skin cancer prevention, among others. Initially, different extraction solvents and methods were applied to dried, ground bark which made possible the preparation of extracts having both significant lethality to brine shrimp larvae (Artemia franciscana Leach as well as antioxidant activity in vitro based on tests involving reactions with 2,2,-diphenyl-1-picrylhydrazyl (DPPH. Analysis of fractions from serial extractions with solvents of increasing polarity supports the notion that antioxidant activity is associated with compounds of intermediate polarity and cytotoxicity is associated with compounds of low to intermediate polarity. Variation of extraction time and conditions revealed that hot, continuous ethanol extraction provided good yields of bark extract in several hours. Hot extraction also provided ethanol extracts having greater lethality to brine shrimp and antioxidant activity (compared to the flavonoid rutin in semi-quantitative methods based on DPPH than extracts obtained from maceration at room temperature. Freeze-dried ethanol extracts were prepared by: 1 maceration at room temperature and 2 hot extraction (eight hours on several hundred gram scales and the latter extract was shown to have partial screening effects on UVB light. In this work, cytotoxic, antioxidant and potential sun-screening activity are shown for the first time in M. guyanensis.Maytenus guyanensisKlotzch. é uma árvore medicinal proveniente da Amazônia conhecida comochichuá (xixuáe no Peru e Colombia porchuchuhuasi. É utilizada medicinalmente como estimulante, tônico e relaxante muscular, para o alívio de artrite, reumatismo, hemorr

EFECTO ANTINOCICEPTIVO DEL EXTRACTO ETANÓLICO DE LAS HOJAS DE MAYTENUS MACROCARPA (RUIZ & PAV.) BRIQ. “CHUCHUHUASI” MEDIANTE LA PRUEBA DE CONTORSIONES ABDOMINALES EN RATONES.

OpenAIRE

V Robles-Pizarro; L Tarqui-Cabrera; N Rodríguez-Collazos; A Morales-Chau; J De La Cruz-Manyari; K Ríos-Melgar; D Rivera-Cruzado; A Rubio-Gonzáles; C Santa Cruz-Contreras; G Velazco-Curay; B Loja-Herrera; A Alvarado-Yarasca; B Castañeda-Castañeda; A Salazar-Granara

2014-01-01

OBJETIVODeterminar el efecto y actividad antinociceptiva de las hojas de Maytenus macrocarpa (Ruiz & Pav) Briq. “chuchuhuasi” mediante la prueba de contorsiones abdominales en roedor.MATERIAL Y MÉTODOSe utilizaron 40 ratones albinos machos, con pesos medios de 25g, se empleó la prueba de contorsiones abdominales para determinar la actividad antinociceptiva. El grupo Control, no recibió ninguna sustancia. Se administró extracto etanólico de las hojas de M. macrocarpa (Ruiz & Pav.) Briq...

Etnobotânica de Plantas Medicinais no Assentamento Monjolinho, município de Anastácio, Mato Grosso do Sul, Brasil Ethnobotany of medicinal plants in the Monjolinho settlement, Anastácio, Mato Grosso do Sul, Brazil

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Simone Alves da Cunha

2011-09-01

Full Text Available O objetivo desse trabalho foi realizar um estudo etnobotânico sobre as plantas medicinais utilizadas pelos moradores do assentamento Monjolinho, Anastácio, Mato Grosso do Sul. Foram entrevistados através do método bola de neve 35 moradores (33 mulheres. As espécies (210 pertencem a 72 famílias, destacando-se as nativas do Cerrado, sendo o restante cultivado próximos das casas. Fabaceae e Asteraceae foram as mais citadas. Das 23 espécies de Fabaceae, 20 são nativas. As espécies que obtiveram o maior número de citações foram jatobá (Hymenaea spp. e o barbatimão (Stryphnodendron obovatum Benth. e as com índice de concordância de uso (CUP alto foram barbatimão (S. obovatum e cancorosa (Maytenus ilicifolia (Schrad. Planch. As folhas foram as partes mais utilizadas. As doenças do aparelho respiratório e geniturinário foram as mais citadas. A diversidade (H'= 5,03 de uso das espécies é alta. O conhecimento foi adquirido entre amigos (37%, cursos (17% ou família (39% e mostra que, ao longo do tempo, há expressivo aproveitamento das espécies medicinais e conhecimento da comunidade.This work carried out an ethnobotanical survey of the medicinal plants used by the inhabitants of the Monjolinho settlement in Anastácio city, in the state of Mato Grosso do Sul. The goal of this work was to verify how residents congregate information brought from their place with information obtained where they live now, and to verify how the knowledge of spontaneous and native species from cerrado varies in relation to the specie cultivated. A total of 35 inhabitants were interviewed using the snowball method (33 women. The species (210 recorded belong to 72 families. Of these, many are native Cerrado species and the remaining species are cultivated next to the houses. Fabaceae and Asteraceae were the most cited families. Of the 23 species of Fabaceae, 20 are native. The species with the highest number of citations were jatobá (Hymenaea spp. and

Ficusonic acid: a new cytotoxic triterpene isolated from Maytenus royleanus (Wall. ex M. A. Lawson) cufodontis

Energy Technology Data Exchange (ETDEWEB)

Din, Ala Ud; Uddin, Ghias [Center for Phytomedicine and Medicinal Organic Chemistry, Institute of Chemical Sciences, University of Peshawar(Pakistan); Hussain, Nusrat; Choudary, Mohammad Iqbal, E-mail: allauddin77@yahoo.com [International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, University of Karachi (Pakistan)

2013-04-15

Phytochemical investigation of the roots of Maytenus royleanus resulted into the isolation of a new cytotoxic triterpene ficusonic acid, 3{beta},21{beta}-dihydroxyolean-12-en-29-oic acid, together with three known compounds, 3{alpha},22{beta}-dihydroxyolean-12-en-29-oic acid, salaspermic acid and orthosphenic acid, reported for the first time from this source. Their structures were established on the basis of extensive spectroscopic techniques. The cytotoxic activity of compound 3{beta},21{beta}-dihydroxyolean-12-en-29-oic acid was evaluated against two cancer cell lines, PC-3 prostate and HeLa cervical cancer lines. 3{beta},21{beta}-dihydroxyolean-12-en-29-oic acid showed weak activity against PC-3 (IC{sub 50} = 35.42 Greek-Small-Letter-Mu mol L{sup -1}) however against HeLa (IC{sub 50} = 20.47 Greek-Small-Letter-Mu mol L{sup -1}), its activity was moderate. (author)

Interacciones farmacológicas de las hojas de Maytenus macrocarpa o “chuchuhuasi” con fármacos inhibitorios y estimuladores de la motilidad intestinal

OpenAIRE

Meléndez-Espíritu, S.; Huaccho Rojas, Juan Jesús; Santos-Cajahuanca, F.; Abanto-Cabeza, C.; Jáuregui-Farfán, J.; Mendoza-Toribio, J.; Morales-Zenteno, E.; Salgado-Silva, L.; Sueyoshi-Hernández, H.; Robles-Ojeda, M.; Loja Herrera, Berta; Alvarado Yarasca, Ángel Tito; Salazar Granara, Alberto Alcibíades

2013-01-01

OBJETIVO: Determinar las posibles interacciones farmacológicas de las hojas de Maytenus macrocarpa, con fármacos estimulantes e inhibitorios de la motilidad intestinal. MÉTODOS: Se utilizaron 110 ratones albinos machos, con pesos medios de 25 g, se empleó el método de Arbos y col, se administró carbón activado al 5 % vía oral, dosis de 0.1ml/10g, como marcador intestinal. Los grupos experimentales fueron: control (agua destilada 0,3ml), hojas de chuchuhuasi 1 (500mg/kg), hojas de chuchuhua...

Acción del extracto etanólico de las hojas de Maytenus macrocarpa (Ruiz. Pav.) Briq. “chuchuhuasi” sobre la motilidad intestinal

OpenAIRE

Alosilla Uscamaita, Annie; Chaves Palomares, Fátima; Ascaño Ramírez, Alberto; Cornejo Liñán, Maria; Huamán Castro, Cynthia; Medina Morales, John; Tomaylla Lima, Frank; Torres Otarola, Claudia; Tordoya Rodríguez, Luis; Vargas Castillo, Hector; Loja Herrera, Berta; Alvarado Yarasca, Ángel; Salazar Granara, Alberto

2013-01-01

OBJETIVODeterminar el efecto del extracto etanólico de las hojas de Maytenus macrocarpa, “chuchuhuasi” sobre la motilidad intestinal en ratón.MATERIAL Y MÉTODOSe utilizó 50 ratones albinos machos, con pesos medios de 25 g, se empleó el método de Arbos y otros, se administró carbón activado al 5 % vía oral, dosis de 0.1ml/10g, como marcador intestinal. Los grupos experimentales fueron: Control (agua destilada 0.1 ml/10g de peso corporal), Sulfato de Atropina 1 mg/kg, Neostigmina 1 mg/kg, extra...

Co-processing Plant Extracts for Improvement of Their Pharmacotechnic Properties

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P. C. Gustmann

2012-11-01

Full Text Available ABSTRACT: The herbal Espinheira Santa (Maytenus ilicifolia can ingested in capsules for treatment of injuries from digestive tract, such as gastritis. However, the large amount of drug administered dose medication adherence difficult, so this study sought an alternative by formulating effervescent granules facilitating drug intake. The obtained granules made by wet and effervescent mixture of citric acid, sodium carbonate and sodium bicarbonate at different concentrations, totaling eight formulations, in addition to lactose as diluent and disintegrant in the composition. The granules were produced in sizes from 1 and 2mm. Rheological tests were compared against the dry extract, analyzed the average particle sizes of beads, mapped its surface by scanning electron microscopy and evaluated their behavior effervescent. The flow properties of the granules showed better values than the dry extract. The co-processed formulations showed average particle sizes distributed closed, where 1mm time effervescence had smaller, respecting all formulations, pharmacopeial limits of maximum 5 minutes. The preparation of effervescent granules Espinheira Santa proved to be a good alternativel, once that have easy preparation, low cost, excellent flow and rapid disintegration.Keywords: Espinheira Santa, effervescent granules, dry extract.

•Antinocicepción opioide del extracto metanólico del Chuchuhuasi (Maytenus krukovii) en un modelo de dolor visceral en ratón.

OpenAIRE

Zimic C, Zimic C; Sánchez L, Sánchez L; Zapater L, Zapater L; Arias M, Arias M; Ulffe G, Ulffe G; Páucar R, Páucar R; Ibáñez V, Lucy; Castañeda C, Benjamín; Salinas I, Salinas I; Arrambide J, Arrambide J

2006-01-01

Evaluamos la acción antinociceptiva del extracto metanólico del Chuchuhuasi (Maytenus krukovii), al 20%, administrado por vía oral, en ratones albinos, machos, raza Webster Suizo obtenidos del Centro Nacional de Producción de Biológicos del Ministerio de Salud del Perú, utilizando un modelo de dolor visceral, mediante la administración de ácido acético al 2%, vía intraperitoneal, a la dosis de 0,05 ml/10g de peso. Observamos una disminución del 50% del número de contorsiones abdominales, en r...

Maytenus erythroxylon Reissek (Celastraceae) ethanol extract presents antidiarrheal activity via antimotility and antisecretory mechanisms.

Science.gov (United States)

Formiga, Rodrigo de Oliveira; Quirino, Zelma Glebya Maciel; Diniz, Margareth de Fátima Formiga Melo; Marinho, Alexsandro Fernandes; Tavares, Josean Fechine; Batista, Leônia Maria

2017-06-28

To investigate the acute toxicity, phytochemical profile, antidiarrheal activity and mechanisms of action of Maytenus erythroxylon ( M. erythroxylon ) ethanol extract. A castor oil-induced diarrhea model was used to evaluate antidiarrheal activity. Intestinal transit and gastric emptying protocols were used to evaluate a possible antimotility effect. K ATP channels, nitric oxide, presynaptic α2-adrenergic and tissue adrenergic receptors were investigated to uncover antimotility mechanisms of action and castor oil-induced enteropooling to elucidate antisecretory mechanisms. All tested doses of the extract (62.5, 125, 250 and 500 mg/kg) possessed antidiarrheal activity, with a significant decrease of the evacuation index. This activity is possibly related to a reduced gastric emptying (125, 250 and 500 mg/kg) and to a decreased percentage of intestinal transit for all tested doses. That last effect seems to be modulated by nitric oxide, K ATP channels and tissue adrenergic receptors. Besides, the extract also presented antisecretory effect due to a decrease of intestinal fluid accumulation. The antidiarrheal effect of M. erythroxylon found in this study involves antimotility and antisecretory mechanisms that may be attributed to the chemical compounds found in this species: saponins, flavonoids, tannins, triterpenes and steroids.

Maytenus erythroxylon Reissek (Celastraceae) ethanol extract presents antidiarrheal activity via antimotility and antisecretory mechanisms

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Formiga, Rodrigo de Oliveira; Quirino, Zelma Glebya Maciel; Diniz, Margareth de Fátima Formiga Melo; Marinho, Alexsandro Fernandes; Tavares, Josean Fechine; Batista, Leônia Maria

2017-01-01

AIM To investigate the acute toxicity, phytochemical profile, antidiarrheal activity and mechanisms of action of Maytenus erythroxylon (M. erythroxylon) ethanol extract. METHODS A castor oil-induced diarrhea model was used to evaluate antidiarrheal activity. Intestinal transit and gastric emptying protocols were used to evaluate a possible antimotility effect. KATP channels, nitric oxide, presynaptic α2-adrenergic and tissue adrenergic receptors were investigated to uncover antimotility mechanisms of action and castor oil-induced enteropooling to elucidate antisecretory mechanisms. RESULTS All tested doses of the extract (62.5, 125, 250 and 500 mg/kg) possessed antidiarrheal activity, with a significant decrease of the evacuation index. This activity is possibly related to a reduced gastric emptying (125, 250 and 500 mg/kg) and to a decreased percentage of intestinal transit for all tested doses. That last effect seems to be modulated by nitric oxide, KATP channels and tissue adrenergic receptors. Besides, the extract also presented antisecretory effect due to a decrease of intestinal fluid accumulation. CONCLUSION The antidiarrheal effect of M. erythroxylon found in this study involves antimotility and antisecretory mechanisms that may be attributed to the chemical compounds found in this species: saponins, flavonoids, tannins, triterpenes and steroids. PMID:28706420

Maytenus distichophylla and Salacia crassifolia: source of products with potential acetylcholinesterase inhibition

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Fernanda L. Ferreira

Full Text Available ABSTRACT The phytochemical study of the extract leaves from Maytenus distichophylla Mart. and Salacia crassifolia (Mart. ex Schult. G. Don, Celastraceae, resulted in the isolation of 3-oxofriedelane, 3β-hydroxyfriedelane, 3β,24-dihydroxyfriedelane, 3-oxo-28,29-dihydroxyfriedelane, two mixtures of pentacyclic triterpenes (α-amyrin with β-amyrin and 3β-stearyloxy-urs-12-ene with 3β-stearyloxy-olean-12-ene, 3β-palmityloxy-urs-12-ene, the steroid β-sitosterol and its glycosylated derivative β-glucosyl-β-sitosterol, tritriacontanoic acid and the natural polymer gutta percha. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts, the mixtures of triterpenes and the isolated constituents were subjected to in vitro acetylcholinesterase inhibitory evaluation. Acetylcholinesterase inhibitory effect was observed for crude chloroform extract leaves from M. distichophylla (100% and S. crassifolia (97.93 ± 5.63% and for the triterpenes 3β,24-dihydroxyfriedelane (99.05 ± 1.12%, 3-oxo-28,29-dihydroxyfriedelane (90.59 ± 3.76% and 3β-palmityloxy-urs-12-ene (97.93 ± 1.47%. The percent inhibitions induced by these natural products were very similar to those produced by physostigmine (93.94 ± 2.10% a standard acetylcholinesterase inhibitor. Therefore, these results open perspectives for the use of these species as source of compounds with similar physostigmine pharmacological effect.

Antinociceptive effects of an extract, fraction and an isolated compound of the stem bark of Maytenus rigida

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Marina V. Martins

2012-01-01

Full Text Available The antinociceptive activity of the Maytenus rigida Mart. (Celastraceae ethanol extract and its ethyl acetate fraction as well as of (--4'-methylepigallocatechin (1, a previously isolated compound, was demonstrated in vivo. ED50 for 1 in the writhing test was 14.14 mg/kg. The acetic acid-induced writhing was inhibited by 98.4, 84.4, and 58.3%, respectively, when mice were treated with the ethanol extract, ethyl acetate fraction, and 1. In the hot plate test, mice pretreated with 1 showed significantly increased reaction times (60-89%. Oral administration of 1 significantly inhibited first and second phases of the formalin-induced pain (50 and 26.5%, respectively, whereas indomethacin inhibited only the second phase of the test (41.2%. Ethanol extract and its fraction showed effects on inflammatory pain, while neurogenic and inflammatory pain suppression by 1 is a strong indication of the presence of both central and peripheral effects and suggests its analgesic and anti-inflammatory potential.

Antinociceptive effects of an extract, fraction and an isolated compound of the stem bark of Maytenus rigida

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Marina V. Martins

2012-06-01

Full Text Available The antinociceptive activity of the Maytenus rigida Mart. (Celastraceae ethanol extract and its ethyl acetate fraction as well as of (--4'-methylepigallocatechin (1, a previously isolated compound, was demonstrated in vivo. ED50 for 1 in the writhing test was 14.14 mg/kg. The acetic acid-induced writhing was inhibited by 98.4, 84.4, and 58.3%, respectively, when mice were treated with the ethanol extract, ethyl acetate fraction, and 1. In the hot plate test, mice pretreated with 1 showed significantly increased reaction times (60-89%. Oral administration of 1 significantly inhibited first and second phases of the formalin-induced pain (50 and 26.5%, respectively, whereas indomethacin inhibited only the second phase of the test (41.2%. Ethanol extract and its fraction showed effects on inflammatory pain, while neurogenic and inflammatory pain suppression by 1 is a strong indication of the presence of both central and peripheral effects and suggests its analgesic and anti-inflammatory potential.

Study on the stability of the Maytenus aquifolium Martius chemical components submitted to ionizing radiation (X-ray and {gamma}); Estudo da estabilidade dos componentes quimicos de Maytenus aquifolium Martius frente a radiacao ionizante (X e {gamma})

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Campos, Patricia

1995-07-01

The interest for medicinal plants has raised again in the last decades, after overcoming a declination period caused by the advances in the researches and development of the synthetic drugs industries. This growing interest has been stimulated mainly by searching cheap and accessible alternative therapies. However, in order to have natural products based treatment in an efficient and safety way, it is necessary to guarantee the plant authenticity, finding adulterations and to assure a low level of microbiological contaminations to avoid damages to consumer's health. The decontamination method should be chosen for eliminating or reduce the microorganisms level without loss of the plant active constituents that would destroy its therapeutic action. At the present work, the possibility of using {gamma} and X electromagnetic radiations to sterilize a Brazilian medicinal plant (Maytenus aquifolium Martius, Celastraceae), which shows anti-ulcer activity, was studied by accomplishing its actives constituent behavior, the triterpenes friedeline and friedelan-3-ol and the phenolic compounds by spectrophotometric techniques (UV-Vis.), high resolution gas chromatography (HRGC) and high resolution gas chromatography coupled to mass spectrometry (HRGC-MS). (author)

Fungos endofíticos associados a plantas medicinais Endophytic fungi associated with medicinal plants

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V Mussi-Dias

2012-01-01

Full Text Available Com a utilização de plantas medicinais em infusões, xaropes, tinturas, ungüentos, dentre outras formas, pressupõe-se que fungos endofíticos, presentes no interior das plantas, mas sem causar doença, possam tornar-se um componente destes produtos, principalmente quando utilizados in natura. Além disso, os fungos endofíticos podem também produzir substâncias tóxicas aos usuários ou mesmo alterar o metabolismo vegetal, modificando a composição e as propriedades medicinais, assim como, a qualidade do produto armazenado e comercializado. Neste sentido, objetivou-se isolar e identificar a flora fúngica endofítica de onze espécies medicinais escolhidas ao acaso. Obtiveram-se culturas-puras dos fungos Phomopsis, Colletotrichum, Pestalotia, Trichoderma, Fusarium, Nigrospora e Glomerella ocorrendo endofiticamente em Plectranthus barbatus, Vernonia condensata, Pfaffia paniculata, Foeniculum vulgare, Cymbopogon citratus, Cymbopogon nardus, Cordia curassavica, Maytenus ilicifolia, Punica granatum, Morus nigra e Bauhinia forficata. As espécies vegetais em que se identificaram o maior número de fungos endofíticos foram Vernonia condensata, Punica granatum e Morus nigra. Todos os fungos recuperados neste trabalho apresentaram características estritamente endofíticas, não manifestando patogenicidade nas espécies hospedeiras. Dentre os fungos detectados, especial atenção deve ser dada ao gênero Fusarium, uma vez que inúmeras espécies deste gênero são conhecidas produtoras de micotoxinas e constituem-se em importantes patógenos pós-colheita.With the use of medicinal plants in infusions, syrups, dyes, unguents, among other forms, it is expected that endophytic fungi, present inside the plants but not causing diseases, become components of these products, especially when used in natura. In addition, endophytic fungi can produce toxic substances to the users or even modify the plant metabolism, altering the medicinal composition and

Maytenus salicifolia Reissek, Celastraceae: triterpenes isolated from stems and antioxidant property of extracts from aerial parts

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Cássia G. Magalhães

2011-06-01

Full Text Available Six pentacyclic triterpenes were isolated from hexane extract of stems of Maytenus salicifolia Reissek, Celastraceae: 30-hydroxyfriedelan-3-one (1, 3,16-dioxofriedelane (2, friedeline (3, lupeol (4, betuline (5 and lup-20(29-en-3,30-diol (6. The structure each one was established on the basis of detailed ¹H and 13C NMR spectral investigation and by comparison with the respective literature values. For compound 1, the complete 2D NMR (HMBC, HMQC and NOESY spectral data were herein reported for the first time. Compounds 1, 2, 5 and 6 were isolated for the first time from this plant. Antioxidant activity is described for some extracts from species of the Celastraceae family, then, the extracts from aerial parts of M. salicifolia were evaluated in relation to antioxidant potential using the DPPH method. Compared to quecertin, the AcEt extract (EAF from leaves, AcEt (EAPF and MeOH (EMPF from pulp fruit and AcEt (EAT and MeOH (EMT from stems showed significant antioxidant property.

Seasonal variation of gastroprotective terpenoids in Maytenus robusta (Celastraceae) quantified by gas chromatography-flame ionization detection (GC-FID).

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Zermiani, Tailyn; Junior, Antonio A S; Ferreira, Renê A; Wagner, Theodoro M; Machado, Marina S; Cechinel-Filho, Valdir; Niero, Rivaldo

2016-11-01

The triterpenes friedelin (1), β-friedelinol (2) and 3,15-dioxo-21α-hydroxyfriedelane (3) in the aerial parts of Maytenus robusta, a Brazilian medicinal plant with antiulcer potential, were seasonally quantified by gas chromatography flame-ionization detection (GC-FID) using an external standard. The method was found to be linear, precise and sensitive. Compounds 1 and 2 were found in M. robusta leaves and branches, with highest concentrations in the leaves collected in autumn, i.e. 3.21 ± 0.16 and 12.60 ± 1.49 mg g-1 dry weight of 1 and 2, respectively. On the other hand, compound 3 was found only in the branches, with the highest concentrations in winter and autumn (0.21 ± 0.01 and 0.20 ± 0.02 mg g-1). The results allow to define the optimal season and plant parts for the collection of M. robusta as a phytotherapeutic drug.

HPTLC finger print and anti-inflammatory activity of ethanolic extract of different Maytenus species grown in Kingdom of Saudi Arabia

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Mohamed F. Alajmi

2013-10-01

Full Text Available Objective: To evaluate and compare the anti-inflammatory activity and to develop HPTLC fingerprint profile of ethanolic extract of Maytenus obscura (M. obscura and Maytenus parviflora (M. parviflora. Methods: Preliminary phytochemical screening was done and HPTLC studies were carried out using CAMAG HPTLC system equipped with Linomat IV applicator, TLC scanner 3, Reprostar 3, CAMAG ADC 2 and WIN CATS-4 software. The anti-inflammatory activity was tested by injecting different groups of rats (6 each with formalin in hind paw and measuring the edema volume before and 1 h after formalin injection. Control group received saline i.p. The extract treatment was injected i.p with doses of 200 and 400 mg/kg 1 h before formalin administration. Indomethacin (30 mg/kg was used as standard. Results: Treatment of rats (i.p. with M. obscura and M. parviflora in doses of 200 and 400 mg/kg inhibited significantly (P<0.05 formalin-induced inflammation by 55.9%, 63.2% and 77.9%, 82.4%, respectively. Preliminary phytochemical studies were done which confirmed the presence of protein, lipid, carbohydrate, phenol, flavonoid, saponin, triterpenoid, alkaloid and anthraquinone. Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with the solvent system: Toluene: ethylacetate: glacial acetic acid (5:2:0.1, v/v/v as mobile phase. HPTLC finger printing of M. obscura revealed major 8 peaks with Rf values in the range of 0.27 to 0.77 and the M. parviflora revealed maximum 9 peaks with Rf values in the range of 0.17 to 0.76. The purity of sample was confirmed by comparing the absorption spectra at start, middle and end position of the band. Conclusions: HPTLC of M. parviflora revealed 8 major spots and 9 spots for M. obscura. HPTLC finger printing of ethanolic extract of M. obscura and M. parviflora may become potential tool for checking authenticity of these species. It may help in quality control against adulterant and act as a biochemical marker

Variabilidade sazonal de constituintes químicos (triterpenos, flavonóides e polifenóis das folhas de Maytenus aquifolium Mart. (Celastraceae

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Janete H. Yariwake

Full Text Available Estudou-se a variabilidade química sazonal em Maytenus aquifolium Mart. (Celastraceae, conhecida como "espinheira santa", em exemplares cultivados em Ribeirão Preto, SP, através da análise das substâncias presentes nas folhas, ao longo das quatro estações em dois anos. O teor de fenóis totais variou de 21,96 a 45,92 mg / g (expresso em mg ácido tânico / g folhas secas, de 55,88 a 93,20 mg triterpenos totais / g folhas secas, e de 1,349 a 3,859 mg flavonóides / g folhas secas. A amostra Primavera 92 apresentou o maior teor de flavonóides e fenóis totais, e a amostra Inverno 94 apresentou o maior teor de triterpenos.

Antifungal Activity of Maytenin and Pristimerin

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Fernanda P. Gullo

2012-01-01

Full Text Available Fungal infections in humans have increased alarmingly in recent years, particularly in immunocompromised individuals. Among the infections systemic candidiasis, aspergillosis, cryptococcosis, paracoccidioidomycosis, and histoplasmosis mortality are more prevalent and more severe in humans. The current high incidence of dermatophytosis is in humans, especially as the main etiologic agents Trichophyton rubrum and Trichophyton mentagrophytes. Molecules pristimerin and maytenin obtained from the plant Maytenus ilicifolia (Celastraceae are known to show various pharmacological activities. This study aimed to evaluate the spectrum of antifungal activity of maytenin and pristimerin and their cytotoxicity in human keratinocytes (NOK cells of the oral mucosa. It was concluded that the best spectrum of antifungal activity has been shown to maytenin with MIC varying from 0.12 to 125 mg/L, although it is also active with pristimerin MIC ranging between 0.12 and 250 mg/L. Regarding the toxicity, both showed to have high IC50. The SI showed high pristimerin against some species of fungi, but SI maytenin was above 1.0 for all fungi tested, showing a selective action of fungi. However, when comparing the two substances, maytenin also showed better results. The two molecules can be a possible prototype with a broad spectrum of action for the development of new antifungal agents.

Survey of plants popularly used for pain relief in Rio Grande do Sul, southern Brazil

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Eveline D. Stolz

Full Text Available Ethnobotanical data can be an important tool in the search for new drugs. The Brazilian Health Surveillance Agency accepts the registration of herbal medicines based on ethnopharmacological and ethnobotanical studies. With the purpose of increasing the knowledge of potentially useful plants for the treatment of painful conditions, we analyzed the ethnobotanical studies carried out in Rio Grande do Sul state (RS-Southern Brazil; we had access to nineteen studies.To our knowledge, this is the first compilation of ethnobotanical studies that focus on pain relief carried out in RS. The species native to RS cited in at least nine (about 50% of these studies were selected. The search retrieved 28 native species cited as used to alleviate painful conditions, which are distributed in eighteen botanical families, being Asteraceae the most mentioned. The species more frequently cited for pain relief were Achyrocline satureioides, Baccharis articulata, Baccharis crispa, Lepidium didymum, Eugenia uniflora and Maytenus ilicifolia. The only species not reported in any pre-clinical study associated with pain relief was B. articulata. Among the six species cited, no studies on clinical efficacy were found. In conclusion, the folk use of native plants with therapeutic purposes is widespread in RS State (Brazil, being pain relief an important property.

Antifungal Activity of Maytenin and Pristimerin

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Gullo, Fernanda P.; Sardi, Janaina C. O.; Santos, Vânia A. F. F. M.; Sangalli-Leite, Fernanda; Pitangui, Nayla S.; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Soares, Luciana A.; Silva, Julhiany F.; Oliveira, Haroldo C.; Furlan, Maysa; Silva, Dulce H. S.; Bolzani, Vanderlan S.; Mendes-Giannini, Maria José S.; Fusco-Almeida, Ana Marisa

2012-01-01

Fungal infections in humans have increased alarmingly in recent years, particularly in immunocompromised individuals. Among the infections systemic candidiasis, aspergillosis, cryptococcosis, paracoccidioidomycosis, and histoplasmosis mortality are more prevalent and more severe in humans. The current high incidence of dermatophytosis is in humans, especially as the main etiologic agents Trichophyton rubrum and Trichophyton mentagrophytes. Molecules pristimerin and maytenin obtained from the plant Maytenus ilicifolia (Celastraceae) are known to show various pharmacological activities. This study aimed to evaluate the spectrum of antifungal activity of maytenin and pristimerin and their cytotoxicity in human keratinocytes (NOK cells of the oral mucosa). It was concluded that the best spectrum of antifungal activity has been shown to maytenin with MIC varying from 0.12 to 125 mg/L, although it is also active with pristimerin MIC ranging between 0.12 and 250 mg/L. Regarding the toxicity, both showed to have high IC50. The SI showed high pristimerin against some species of fungi, but SI maytenin was above 1.0 for all fungi tested, showing a selective action of fungi. However, when comparing the two substances, maytenin also showed better results. The two molecules can be a possible prototype with a broad spectrum of action for the development of new antifungal agents. PMID:22675379

Medicinal Plants Used by a Mbyá-Guarani Tribe Against Infections: Activity on KPC-Producing Isolates and Biofilm-Forming Bacteria.

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Brandelli, Clara Lia Costa; Ribeiro, Vanessa Bley; Zimmer, Karine Rigon; Barth, Afonso Luís; Tasca, Tiana; Macedo, Alexandre José

2015-11-01

The traditional use of medicinal plants for treatment of infectious diseases by an indigenous Mbyá-Guarani tribe from South Brazil was assessed by evaluating the antibiotic and antibiofilm activities against relevant bacterial pathogens. Aqueous extracts from 10 medicinal plants were prepared according to indigenous Mbyá-Guarani traditional uses. To evaluate antibiotic (OD600) and antibiofilm (crystal violet method) activities, Pseudomonas aeruginosa ATCC 27853, Staphylococcus epidermidis ATCC 35984 and seven multi-drug resistant Klebsiella pneumoniae carbapenemase (KPC)-producing bacterial clinical isolates were challenged with the extracts. Furthermore, the susceptibility profile of KPC-producing bacteria and the ability of these isolates to form biofilm were evaluated. The plants Campomanesia xanthocarpa, Maytenus ilicifolia, Bidens pilosa and Verbena sp. showed the best activity against bacterial growth and biofilm formation. The majority of KPC-producing isolates, which showed strong ability to form biofilm and a multidrug resistance profile, was inhibited by more than 50% by some extracts. The Enterobacter cloacae (KPC 05) clinical isolate was the only one resistant to all extracts. This study confirms the importance of indigenous traditional medicinal knowledge and describes for the first time the ability of these plants to inhibit biofilm formation and/or bacterial growth of multi-drug resistant KPC-producing isolates.

Herbs of interest to the Brazilian Federal Government: female reproductive and developmental toxicity studies

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Luiz Fernando Verissimo

2011-12-01

Full Text Available In 2009 the Brazilian Ministry of Health published a document named RENISUS that lists 71 herbs traditionally used in Brazil that could result in phytomedicines to be dispensed by the governmental health care program. This manuscript reviews female reproductive and/or developmental toxicity information of these herbs. More than half (35 of the herbs lack information regarding female reproductive and/or developmental effects. From the fourteen herbs used traditionally to disturb female reproduction, five present experimental data corroborating their actions as abortifacients (Maytenus ilicifolia, Momordica charantia, Plectranthus barbatus, Ruta graveolens or labour facilitator (Bidens pilosa. For 23 of the herbs evaluated experimentally for any type of female reproductive endpoint, only a single study was retrieved and at least twelve of these studies were conducted with a single dose. This scenario suggests that the scientific power of the published information is very low and that a scientifically-based risk/benefit analysis about the use of these herbs during pregnancy is not possible. Considering the appeal that phytomedicines have for pregnant women, usually aware and afraid of the risks that synthetic drugs may have in their pregnancy and progeny, well designed studies evaluating reproductive and/or developmental toxicity of these herbs urge.

Herbs of interest to the Brazilian Federal Government: female reproductive and developmental toxicity studies

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Luiz Fernando Verissimo

2011-08-01

Full Text Available In 2009 the Brazilian Ministry of Health published a document named RENISUS that lists 71 herbs traditionally used in Brazil that could result in phytomedicines to be dispensed by the governmental health care program. This manuscript reviews female reproductive and/or developmental toxicity information of these herbs. More than half (35 of the herbs lack information regarding female reproductive and/or developmental effects. From the fourteen herbs used traditionally to disturb female reproduction, five present experimental data corroborating their actions as abortifacients (Maytenus ilicifolia, Momordica charantia, Plectranthus barbatus, Ruta graveolens or labour facilitator (Bidens pilosa. For 23 of the herbs evaluated experimentally for any type of female reproductive endpoint, only a single study was retrieved and at least twelve of these studies were conducted with a single dose. This scenario suggests that the scientific power of the published information is very low and that a scientifically-based risk/benefit analysis about the use of these herbs during pregnancy is not possible. Considering the appeal that phytomedicines have for pregnant women, usually aware and afraid of the risks that synthetic drugs may have in their pregnancy and progeny, well designed studies evaluating reproductive and/or developmental toxicity of these herbs urge.

In vitro effects of aqueous extract from Maytenus senegalensis (Lam.) Exell stem bark on egg hatching, larval migration and adult worms of Haemonchus contortus.

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Zangueu, Calvin Bogning; Olounlade, Abiodoun Pascal; Ossokomack, Marlyse; Djouatsa, Yolande Noelle Nangue; Alowanou, Goue Géorcelin; Azebaze, Anatole Guy Blaise; Llorent-Martínez, Eulogio José; de Córdova, Maria Luisa Fernández; Dongmo, Alain Bertrand; Hounzangbe-Adote, Mawulé Sylvie

2018-05-02

Maytenus senegalensis is a common shrub which is scattered in tropical Africa. Different parts of this plant have been reported to be useful in traditional medicine against gastrointestinal disorders and intestinal worms. This study evaluated the anthelmintic activity of the aqueous stem bark extract of M. senegalensis using egg hatch assay (EHA), larval migration inhibition assay (LMIA) and adult worms' motility inhibition assay (AMIA). On EHA, the extract concentrations tested resulted in a significant (p  50%). These in vitro results suggest the presence of some anthelmintic properties in M. senegalensis extract, which is traditionally used by small farmers in west and central Africa. These effects may be due to the flavonoids and proanthocyanidins present in the extract and need to be studied under in vivo conditions.

Genotoxicity test of Maytenus rigida and Aristolochia birostris in the radicular meristem of the onion, Allium cepa

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Sandra S. Mendes

2011-09-01

Full Text Available Medicinal plants are an important source of treatment for many ailments, although little is known of the potential genotoxic effects of most species. In the present study, two species from diverse and medicinally important genera - Maytenus rigida Mart., Celastraceae, and Aristolochia birostris Ducht, Aristolochiaceae - were analyzed to identify potentially significant secondary metabolites and the possible effects of their aqueous and alcoholic extracts on cell division in the onion root stem (genotoxicity test. The phytochemical testing revealed the presence of a number of potentially important secondary compounds in both species, including phenols, flavonoids, triterpenoids, steroids, and saponins. In the genotoxicity tests, no chromosomal abnormalities of any kind were observed in either species. In the case of M. rigida, a significant increase in mitotic activity was observed at the highest concentration. No significant tendency was recorded in A. birostris, although a considerable increase in the prophase was observed at all concentrations of the alcoholic extract. The triterpenoid content of both species may be especially important from a medicinal viewpoint, although recent findings on the carcinogenic potential of Aristolochia extracts demands caution in the interpretation of the results, and the need for further research.

Genotoxicity test of Maytenus rigida and Aristolochia birostris in the radicular meristem of the onion, Allium cepa

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Sandra S. Mendes

2012-02-01

Full Text Available Medicinal plants are an important source of treatment for many ailments, although little is known of the potential genotoxic effects of most species. In the present study, two species from diverse and medicinally important genera - Maytenus rigida Mart., Celastraceae, and Aristolochia birostris Ducht, Aristolochiaceae - were analyzed to identify potentially significant secondary metabolites and the possible effects of their aqueous and alcoholic extracts on cell division in the onion root stem (genotoxicity test. The phytochemical testing revealed the presence of a number of potentially important secondary compounds in both species, including phenols, flavonoids, triterpenoids, steroids, and saponins. In the genotoxicity tests, no chromosomal abnormalities of any kind were observed in either species. In the case of M. rigida, a significant increase in mitotic activity was observed at the highest concentration. No significant tendency was recorded in A. birostris, although a considerable increase in the prophase was observed at all concentrations of the alcoholic extract. The triterpenoid content of both species may be especially important from a medicinal viewpoint, although recent findings on the carcinogenic potential of Aristolochia extracts demands caution in the interpretation of the results, and the need for further research.

Antiulcerogenic activity of fractions and 3,15-dioxo-21alpha-hydroxy friedelane isolated from Maytenus robusta (Celastraceae).

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de Andrade, Sérgio Faloni; Comunello, Eros; Noldin, Vânia Floriani; Monache, Franco Delle; Cechinel Filho, Valdir; Niero, Rivaldo

2008-01-01

The hexane, chloroform, ethyl acetate and aqueous-soluble fractions from leaves of Maytenus robusta (Celastraceae) were evaluated for their protective actions against ethanol-induced gastric lesions in rats. The treatment with all fractions (150 mg/kg) and omeprazol (30 mg/kg) significantly reduced the lesion index, the total lesion area, and the percentage of lesion, in comparison with the control group (p<0.05). Since the ethyl acetate-soluble fraction was found to be most active in the pylorus ligated model, this fraction was further investigated and resulted in the isolation of triterpene 3,15-dioxo-21alpha-hydroxy friedelane. The triterpene was evaluated in the HCl/ethanol-induced ulcer model in mice. In this assay, both the groups treated with 3,15-dioxo-21alpha-hydroxy friedelane and omeprazol, at a dose of 30 mg/kg, presented a significant reduction in lesion index, total lesion area, and in the percentage of the lesion, when compared with the control group (p<0.05). The result suggests that the antiulcer effect observed in the extract and fractions may be attributed, at least in part, to this compound. Further experiments are underway to determine which antiulcer mechanisms involved in gastroprotection.

Anti-inflammatory activity and qualitative analysis of different extracts of Maytenus obscura (A. Rich.) Cuf. by high performance thin layer chromatography method

Institute of Scientific and Technical Information of China (English)

Mohamed F. Alajmi; Perwez Alam

2014-01-01

Objective: To perform aqueous ethanol soluble fraction (AESF) and dichloromethane extract of aerial parts of Maytenus obscura (A. Rich.) Cuf. using high performance thin layer chromatography (HPTLC) and to test anti-inflammatory activity of these extracts.Methods:HPTLC studies were carried out using CAMAG HPTLC system equipped with Linomat IV applicator, TLC scanner 3, Reprostar 3, CAMAG ADC 2 and WIN CATS-4 software were used. The anti-inflammatory activity was tested by injecting different groups of rats (6 each) with formalin in hind paw and measuring the edema volume before and 1 h later formalin injection. Control group received saline i.p. The extracts treatment was injected i.p. in doses of 100 and 200 mg/kg 1 h before formalin administration. Indomethacin (30 mg/kg) was used as standard.Results:The results of preliminary phytochemical studies confirmed the presence of protein, lipid, carbohydrate, phenol, flavonoid, saponin, triterpenoid, alkaloid and anthraquinone in both extracts. Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with the green solvents toluene: ethyacetate: glacial acetic acid (5:3:0.2, v/v/v) as mobile phase. HPTLC finger printing of AESF revealed major eight peaks with Rf values in the range of 0.28 to 0.80 and the dichloromethane revealed major 11 peaks with Rf values in the range of 0.12 to 0.76. The purity of sample was confirmed by comparing the absorption spectra at start, middle and end position of the band. Treatment of rats (i.p.) with AESF and dichloromethane in doses of 100 and 200 mg/kg inhibited singnificantly (P<0.05, n=6) formalin-induced inflammation by 50%, 55.9%, 45.5%, and 51.4%, respectively.Conclusions:HPTLC finger printing of AESF and dichloromethane of Maytenus obscura revealed eight major spots for alcoholic extracts and nine major spots for dichloromethane extracts. These HPTLC profiles may be of great usefulness in the quality control of herbal products containing these extracts. The

Dihydro-β-agarofurans from the roots of the Australian endemic rainforest tree Maytenus bilocularis act as leucine transport inhibitors.

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Wibowo, Mario; Wang, Qian; Holst, Jeff; White, Jonathan M; Hofmann, Andreas; Davis, Rohan A

2018-04-01

Phytochemical studies of the roots of the Australian plant, Maytenus bilocularis, resulted in the identification of six previously undescribed dihydro-β-agarofuran sesquiterpenoids, bilocularins D-I, along with three known natural products, namely 1α,2α,6β,15-tetraacetoxy-9β-benzoyloxydihydro-β-agarofuran, pristimerin, and celastrol. The structures of all compounds were characterized via analysis of 1D/2D NMR and MS data. The absolute configuration of bilocularin D was defined by X-ray crystallography analysis. Bilocularins D and G, 1α,2α,6β,15-tetraacetoxy-9β-benzoyloxydihydro-β-agarofuran, and celastrol inhibited leucine transport in the human prostate cancer cell line LNCaP with IC 50 values ranging from 2.5-27.9 μM, which were more potent than the L-type amino acid transporter (LAT) family inhibitor 2-aminobicyclo[2,2,1]-heptane-2-carboxylic acid (BCH). Bilocularins D-F are the first examples of dihydro-β-agarofurans bearing a hydroxyacetate group. Copyright © 2018 Elsevier Ltd. All rights reserved.

Study on the stability of the Maytenus aquifolium Martius chemical components submitted to ionizing radiation (X-ray and γ)

International Nuclear Information System (INIS)

Campos, Patricia

1995-01-01

The interest for medicinal plants has raised again in the last decades, after overcoming a declination period caused by the advances in the researches and development of the synthetic drugs industries. This growing interest has been stimulated mainly by searching cheap and accessible alternative therapies. However, in order to have natural products based treatment in an efficient and safety way, it is necessary to guarantee the plant authenticity, finding adulterations and to assure a low level of microbiological contaminations to avoid damages to consumer's health. The decontamination method should be chosen for eliminating or reduce the microorganisms level without loss of the plant active constituents that would destroy its therapeutic action. At the present work, the possibility of using γ and X electromagnetic radiations to sterilize a Brazilian medicinal plant (Maytenus aquifolium Martius, Celastraceae), which shows anti-ulcer activity, was studied by accomplishing its actives constituent behavior, the triterpenes friedeline and friedelan-3-ol and the phenolic compounds by spectrophotometric techniques (UV-Vis.), high resolution gas chromatography (HRGC) and high resolution gas chromatography coupled to mass spectrometry (HRGC-MS). (author)

Acute genotoxicity analysis in vivo of the aqueous extract of Maytenus guyanensis Amazonian chichuá

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Dionatas Ulises de Oliveira Meneguetti

Full Text Available Abstract The species Maytenus guyanensis Klotzsch ex Reissek, Celastraceae, present a wide variety of possible pharmacological activities and its roots and stems are used by popular medicine in the western Amazon rainforest. Few studies have demonstrated the genotoxic safety of the popular use of this species, and owing to this, the present study aimed to perform an analysis of the acute genotoxicity in vivo of the aqueous extract of M. guyanensis. Male and female mice from Mus musculus species, of weights ranging from 20 to 40 g, organized in eight groups with different treatments were used. The aqueous extracts of the bark of M. guyanensis were administered orally by gavage with 0.1 ml of the test substance per 10 g of the animal, followed by performance of comet assay in peripheral blood, PCE/NCE correlation and occurrence of micronuclei in the bone marrow. It was found that the aqueous extract of M. guyanensis, with ten times higher concentration than those used in ethnopharmacology, did not present genotoxic effect and, moreover, it has antigenotoxic action in mice treated acutely. Further studies regarding bioaccumulation and chronic effects of this species are suggested, in order to improve the understanding of its mechanism of action, ensuring the efficacy and safety of its utilization and developing phytotherapics and drugs.

Testicular Dysfunction Ameliorative Effect of the Methanolic Roots Extracts of Maytenus procumbens and Ozoroa paniculosa

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Nkosinathi David Cele

2017-01-01

Full Text Available The traditional use of medicinal plants in the management of sexual dysfunctions has a long history. This study investigated testicular dysfunction ameliorative effect of the methanolic roots extracts of Maytenus procumbens and Ozoroa paniculosa in a butanol-induced testicular dysfunction rat model. The rats in respective experimental groups were orally administered with the extract at 50 and 250 mg/kg bw, daily for 28 days. The cytotoxicity of the extracts was evaluated against HEK293, MCF-7, and HT29 cell lines. The extracts exhibited moderate (LC50 30.3–330.2 μg/mL to weak (LC50 200.8–438.4 μg/mL cytotoxicity level on the cancer and normal cells, respectively. While relatively lower serum testosterone levels and total sperm count along with decreased numbers of spermatogonia were noted in the untreated group, all these parameters were improved in the groups treated with the extracts at 250 mg/kg. Improved histomorphological changes of the testes were also observed when compared to the untreated group. While the extracts (at 250 mg/kg increased serum reduced glutathione content and decreased malondialdehyde content, a relatively higher serum creatinine level was also observed in the treated animals group. The results indicate that the two plant extracts have potential to ameliorate testicular dysfunction.

Analysis of the elementary composition of the phytoterapics Espinheira Santa and eggplant by the method of Neutron Activation Analysis

International Nuclear Information System (INIS)

Pereira, Luan M.; Saiki, Mitiko

2017-01-01

The use of herbal medicines has become quite popular in Brazil due to its vast flora and the belief that everything that is natural does not present harmful effects to human health. However, these products may contain toxic or excessively harmful to the human organism. The objective of this work was to analyze herbal medicine Espinheira Santa (Maytenus ilicifolia) and Eggplant (Solanum melongena) by the method of neutron activation analysis (NAA). Phytotherapeutic samples were obtained from drugstores in the form of capsules, and their contents were removed from the capsules for analysis. The NAA procedure consisted of irradiate phytotherapeutic aliquots and the synthetic neutron element patterns of the nuclear reactor IEAR-1 followed by gamma-ray spectrometry. The radioisotopes formed were identified by half lives and gamma ray energies and the concentrations of the elements were calculated by the comparative method. For analytical quality control, the certified reference materials were analyzed and the results presented good accuracy and precision. In the phytoterapics, the elements K and Ca were found in higher concentrations, in the order of mg g -1 , Br, Fe, Rb and Zn of the order of μg g -1 and the elements Co, Cr, Cs, La and Sc of the order of ng g -1 . Results obtained in this work demonstrated the feasibility of applying the NAA procedure in the determination of the elemental composition of phytoterapics

Potential pitfalls in the nuclear medicine imaging: Experimental models to evaluate the effect of natural products on the radiolabeling of blood constituents, bioavailability of radiopharmaceutical and on the survival of Escherichia coli strains submitted to the treatment with stannous ion

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Soares, Scheila F. [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil); Brito, Lavinia C. [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil); Souza, Deise E. [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil); Bernardo, Luciana C. [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil); Oliveira, Joelma F. [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil); Bernardo-Filho, Mario [Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofisica e Biometria, Laboratorio de Radiofarmacia Experimental, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro, 87, Rio de Janeiro, RJ 20551-030 (Brazil)]. E-mail: bernardo@uerj.br

2006-12-20

Single photon emission computed tomography (SPECT) allows studies of physiological or pathological processes. Red blood cells labeled with technetium-99m ({sup 99m}Tc-RBC) are used as a radiopharmaceutical in several evaluations. The radiolabeling efficiency and bioavailability of radiopharmaceuticals can be altered by natural/synthetic drugs and may induce pitfalls in the analysis of the nuclear medicine imaging. The labeling with {sup 99m}Tc requires a reducing agent and stannous chloride (SnCl{sub 2}) is widely utilized. However, SnCl{sub 2} presents a citotoxic and/or genotoxic potential in Escherichia coli (E. coli) strains. The aim of this work was to evaluate the influence of aqueous extracts of Baccharis genistelloides (BG), Terminalia chebula (TC), Maytenus ilicifolia (MI), Cassia angustifolia (CA) and Equisetum arvense (EA) on (i) radiolabeling of blood constituents (ii) bioavailability of sodium pertechnetate(Na{sup 99m}TcO{sub 4}) radiopharmaceutical (iii) survival of E. coli. In vitro labeling of RBC was performed with blood (Wistar rats) incubated with each extract, SnCl{sub 2} and Na{sup 99m}TcO{sub 4}. Plasma (P) and blood cells (BC) were isolated, another aliquots precipitated and soluble (SF) and insoluble (IF) fractions isolated and counted. In the bioavailability of Na{sup 99m}TcO{sub 4}, Wistar rats were treated (7 days) with aqueous extract or with 0.9%NaCl, the radiopharmaceutical was administered, the animals sacrificed, the organs isolated, weighted and radioactivity counted. To evaluate the effect on the bacterial survival, E. coli was treated with: (a) SnCl{sub 2}; (b) 0.9% NaCl; (c) vegetal extract; or (d) SnCl{sub 2} and vegetal extract. Radiolabeling efficiency showed a significantly decrease (ANOVA/Tukey post-test, p<0.05) after treatment with BG, TC, MI and CA extracts. The bioavailability results showed that the uptake of Na{sup 99m}TcO{sub 4} was altered significantly (unpaired t-student test, p<0.05) in blood, lungs (CA

Avaliação da Qualidade de Amostras de Plantas Medicinais Comercializadas no Brasil

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Renato Pamplona Cardozo Costa

2014-08-01

Full Text Available Drogas vegetais constituem uma das matérias-primas utilizadas na fabricação de fitoterápicos, além de serem largamente utilizadas pela população como recurso terapêutico. O mercado de produtos derivados de matéria-prima vegetal, com isso, se tornou alvo de investimentos de empresas do setor farmacêutico. O presente trabalho objetivou verificar a qualidade de drogas vegetais comercializadas no mercado brasileiro, utilizando-se conjuntamente métodos de análise simples e de baixo custo.Para tanto , foram usadas amostras de “centela”, “chá verde” e “espinheira santa”, obtidas em estabelecimentos comerciais, sendo sua identidade e qualidade avaliadas por meio de análises anatômicas e microquímicas. O estudo anatômico demonstrou que as três amostras de centela continham Centella asiatica, estando algumas em mau estado de conservação. Os contaminantes desta amostra eram principalmente outras partes do corpo vegetativo de C. asiatica, além de folhas de Poaceae e de outras espécies vegetais. Duas amostras de chá verde foram identificadas como Camellia sinensis e apresentavam caules da mesma espécie como contaminantes. A terceira amostra de chá verde era constituída por Ilex paraguariensis, sendo que folhas de Bambusoideae (Poaceae também foram encontradas. Uma das amostras de espinheira santa era constituída de Sorocea bonplandii. As demais continham folhas e fragmentos de caule de Maytenus ilicifolia. As três amostras de centela apresentaram saponinas triterpênicas. Todas as amostras de chá verde possuíam metilxantinas. Dessas, apenas aquelas constituídas por C. sinensis demonstraram a presença de flavonoides. As amostras de espinheira-santa apresentaram taninos condensados. Desse modo, as metodologias propostas forneceram resultados complementares que podem ser empregados no controle de qualidade de drogas vegetais.

Genetic diversity and structure in natural populations of Maytenus truncata Reiss, 1861, a medicinal plant vulnerable to extractivism in Bahia State, Brazil.

Science.gov (United States)

Simplicio, R R; Waldschmidt, A M; Amorim, M B; Almeida, B S; Pereira, D G

2015-12-28

Maytenus truncata (Celastraceae) is a plant species widely used in the treatment of ulcers and tumors. Despite the intensive harvest of native specimens in the State of Bahia, northeastern Brazil, there is no information about the genetic variability or structure of this species. Therefore, the goal of this study was to estimate the genetic diversity and population structure of M. truncata based on inter simple sequence repeat (ISSR) molecular markers. The samples comprised specimens from Jequié, Contendas do Sincorá, Boa Nova, and Boa Vista do Tupim in the State of Bahia. After selection of eight ISSR primers, the percentage of polymorphic loci was equal to 96.2% and genetic diversity was 0.3581. The Mantel test revealed positive correlation among genetic and geographic distances (r = 0.5462), but it was not significant (r ≥ 0, P = 0.8365). Even though AMOVA revealed that most variation was found within populations (68%), a high structuring was detected among them (ΦST = 0.31, P extractivism of populations of this species.

Foliar manganese accumulation by Maytenus founieri (Celastraceae) in its native New Caledonian habitats: populational variation and localization by X-ray microanalysis.

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Fernando, D R; Woodrow, I E; Jaffré, T; Dumontet, V; Marshall, A T; Baker, A J M

2008-01-01

Hyperaccumulation by plants is a rare phenomenon that has potential practical benefits. The majority of manganese (Mn) hyperaccumulators discovered to date occur in New Caledonia, and little is known about their ecophysiology. This study reports on natural populations of one such species, the endemic shrub Maytenus founieri. Mean foliar Mn concentrations of two populations growing on ultramafic substrates with varying soil pHs were obtained. Leaf anatomies were examined by light microscopy, while the spatial distributions of foliar Mn in both populations were examined by qualitative scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Plants growing on two different substrates were found to have very different mean dry weight (DW) foliar Mn concentrations. Light microscopy showed that the leaves had very distinct thick dermal structures, consisting of multiple layers of large cells in the hypodermis. In vivo X-ray microprobe analyses revealed that, in both populations, Mn sequestration occurred primarily in these dermal tissues. The finding here that foliar Mn is most highly localized in the nonphotosynthetic tissues of M. founieri contrasts with results from similar studies on other woody species that accumulate high Mn concentrations in their shoots.

Determination of herb authenticity by low-field NMR.

Science.gov (United States)

Preto, M S M; Tavares, M I B; Sebastião, P J O; Azeredo, R B V

2013-02-15

The safe use of herbal medicines requires prior authentication of the raw materials used to make them. This is an important step, since the ingestion of herbal preparations or extracts can cause serious health problems. Among the different analytical techniques, nuclear magnetic resonance (NMR) spectroscopy has the advantage of being non-invasive and therefore suitable for the characterization of natural products such as medicinal plants. This work presents a characterisation study of the samples of the popular plant Maytenus ilicifolia, obtained from different commercial producers. This plant is used for the treatment of gastrointestinal disorders, as it possesses antitumorigenic, analgesic, anti-inflammatory and antioxidant properties. The differences in the chemical structure and molecular organisation detected by thermogravimetric analysis (TGA), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) were also investigated by proton nuclear magnetic resonance relaxometry, in particular by fast field cycling (FFC) relaxometry, and relaxometry in the rotating frame. All results confirmed the similarity between the control sample and only one of the plant investigated. The differences detected between the samples could be related to their non-authenticity, due to the non recognise the plant due to the leaves similarity among plants from the same family and/or contamination, due to addition of similar other plants parts to the commercial ones, as they are mixed together this difficulties the acceptation of the plant. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of the elementary composition of the phytoterapics Espinheira Santa and eggplant by the method of Neutron Activation Analysis; Análise da composição elementar dos fitoterápicos espinheira santa e berinjela pelo método de análise por ativação com nêutrons

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Pereira, Luan M.; Saiki, Mitiko, E-mail: luan.pereira@usp.br, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

The use of herbal medicines has become quite popular in Brazil due to its vast flora and the belief that everything that is natural does not present harmful effects to human health. However, these products may contain toxic or excessively harmful to the human organism. The objective of this work was to analyze herbal medicine Espinheira Santa (Maytenus ilicifolia) and Eggplant (Solanum melongena) by the method of neutron activation analysis (NAA). Phytotherapeutic samples were obtained from drugstores in the form of capsules, and their contents were removed from the capsules for analysis. The NAA procedure consisted of irradiate phytotherapeutic aliquots and the synthetic neutron element patterns of the nuclear reactor IEAR-1 followed by gamma-ray spectrometry. The radioisotopes formed were identified by half lives and gamma ray energies and the concentrations of the elements were calculated by the comparative method. For analytical quality control, the certified reference materials were analyzed and the results presented good accuracy and precision. In the phytoterapics, the elements K and Ca were found in higher concentrations, in the order of mg g{sup -1}, Br, Fe, Rb and Zn of the order of μg g{sup -1} and the elements Co, Cr, Cs, La and Sc of the order of ng g{sup -1}. Results obtained in this work demonstrated the feasibility of applying the NAA procedure in the determination of the elemental composition of phytoterapics.

Capacidade de enraizamento de estacas de Maytenus muelleri Schwacke com a aplicação de ácido indol butírico relacionada aos aspectos anatômicos Rooting capacity of Maytenus muelleri Schwacke cuttings with indolebutyric acid application related to anatomical aspects

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D.M. Lima

2011-01-01

Full Text Available A espinheira-santa (Maytenus muelleri - Celastraceae é a planta medicinal nativa do Sul do Brasil, cujas folhas são tradicionalmente utilizadas pela medicina popular para o tratamento de úlceras e outros problemas gástricos. Existem poucos trabalhos publicados sobre a produção de mudas e técnicas de propagação vegetativa da espécie. A propagação de espinheira-santa por estaquia poderia ser um método eficiente para obtenção de material homogêneo, com características genéticas desejáveis, produzido a partir de plantas matrizes selecionadas. O presente trabalho teve por objetivo estudar os efeitos da aplicação de ácido indol butírico (AIB, em solução e em pó, no enraizamento de estacas de espinheira-santa coletadas nas quatro estações do ano (abril/2005 a janeiro/2006, bem como averiguar, por meio de análises anatômicas e histoquímicas das estacas, a presença de possíveis impedimentos à iniciação do enraizamento adventício. Estacas provenientes de ramos de plantas matrizes de seis anos cultivadas da Estação Experimental do Canguiri, Pinhais, PR, foram coletadas e tratadas com AIB (0, 1500, 3000 mg L-1 ou mg kg-1, em solução alcoólica (50% v/v e em talco. Aos 365 dias foram avaliadas as porcentagens de estacas enraizadas e mortas, número e comprimento médio de raízes formadas por estaca. Análises anatômicas e histoquímicas com lugol e cloreto férrico foram realizadas. A estação mais promissora para o enraizamento foi o verão/2006 com 62,50% para o tratamento controle, devido à menor lignficação dos ramos no período de intenso crescimento vegetativo. O número médio de raízes formadas por estaca foi de 6,94 (solução e o comprimento médio de raízes formadas/estaca chegou a 4,82 cm nesta mesma estação. As concentrações de AIB aplicadas não foram eficientes na indução radicial, independentemente do modo de aplicação. Foi detectada a presença de uma camada quase contínua de fibras e

Distinct sesquiterpene pyridine alkaloids from in Salvadoran and Peruvian Celastraceae species.

Science.gov (United States)

Callies, Oliver; Núñez, Marvin J; Perestelo, Nayra R; Reyes, Carolina P; Torres-Romero, David; Jiménez, Ignacio A; Bazzocchi, Isabel L

2017-10-01

As part of a bioprospecting program aimed at the discovery of undescribed natural products from Salvadoran and Peruvian flora, the phytochemical investigations of four Celastraceae species, Celastrus vulcanicola, Maytenus segoviarum, Maytenus jeslkii, and Maytenus cuzcoina, were performed. The current study reports the isolation and structural characterization of five previously undescribed macrolide sesquiterpene pyridine alkaloids, named vulcanicoline-A, cuzcoinine, vulcanicoline-B, jelskiine, and vulcanicoline-C, along with sixteen known alkaloids. The structures of the alkaloids were established by spectrometric and extensive 1D and 2D NMR spectroscopic analysis, including COSY, HSQC, HMBC, and ROESY experiments. The absolute configurations of alkaloids were proposed based on optical rotation sign, and biogenetic considerations. This study represents the first phytochemical analysis of Maytenus segoviarum. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of fungal bio burden and mycotoxins presence in irradiated samples of medicinal plants purchased from wholesale and retail market

International Nuclear Information System (INIS)

Aquino, Simone

2007-01-01

This present study evaluated the effect of gamma radiation on the fungal survival in packed medicinal plants, purchased from wholesale and retail market, in different period (0 and 30 days) after the treatment. Five kind of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia, Paullinia cupana and Cassia angustifolia), were collected from different cities of Sao Paulo State, and submitted to irradiation treatment using a 60 Co source (type Gammacell 220) with doses of 5,0 kGy and 10 kGy and at dose rate of 3.0 kGy/h. Non-irradiated samples (control group) were used for fungal counts and serial dilutions from 10 -1 to 10 -6 of the samples were seeded in duplicates and plated using the surface culture method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25 deg C. The control group revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi and a few samples of control group were within the safety limits of World Health Organization (WHO, 1998) to medicinal plants. In response to resistance of ionizing treatment, in the dose of 5 kGy, it was observed that the genera Aspergillus, Phoma and Syncephalastrum were radio-resistant after the process (day 0 and 30th day). The treatment by gamma radiation was effective in decontamination of all irradiated samples of medicinal plants, after 30 days, with the dose of 10 kGy and kept of veiled conditions. It was not detected aflatoxins in samples of control group, even though these samples were heavily contaminated with Aspergillus flavus. (author)

Evaluation of fungal bio burden and mycotoxins presence in irradiated samples of medicinal plants purchased from wholesale and retail market; Avaliacao da microbiota fungica e da presenca de micotoxinas em amostras de plantas medicinais irradiadas adquiridas no comercio varejista e atacadista

Energy Technology Data Exchange (ETDEWEB)

Aquino, Simone

2007-07-01

This present study evaluated the effect of gamma radiation on the fungal survival in packed medicinal plants, purchased from wholesale and retail market, in different period (0 and 30 days) after the treatment. Five kind of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia, Paullinia cupana and Cassia angustifolia), were collected from different cities of Sao Paulo State, and submitted to irradiation treatment using a {sup 60}Co source (type Gammacell 220) with doses of 5,0 kGy and 10 kGy and at dose rate of 3.0 kGy/h. Non-irradiated samples (control group) were used for fungal counts and serial dilutions from 10{sup -1} to 10{sup -6} of the samples were seeded in duplicates and plated using the surface culture method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25 deg C. The control group revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi and a few samples of control group were within the safety limits of World Health Organization (WHO, 1998) to medicinal plants. In response to resistance of ionizing treatment, in the dose of 5 kGy, it was observed that the genera Aspergillus, Phoma and Syncephalastrum were radio-resistant after the process (day 0 and 30th day). The treatment by gamma radiation was effective in decontamination of all irradiated samples of medicinal plants, after 30 days, with the dose of 10 kGy and kept of veiled conditions. It was not detected aflatoxins in samples of control group, even though these samples were heavily contaminated with Aspergillus flavus. (author)

Horta orgânica de ervas medicinais: inclusão social na comunidade da Barra em Muriaé/MG - Brasil

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José Luiz de Freitas Paixão

2013-09-01

Full Text Available Foi implantada uma horta orgânica de ervas medicinais na comunidade da Barra (Muriaé, MG com o objetivo de inclusão social de pessoas carentes ao permitir acesso ao tratamento por fitoterapia. O início das atividades foi em janeiro de 2006, com a escolha das espécies, obtenção de mudas e instalação da horta. As 40 espécies selecionadas, sob manejo agroecológico, eram indicadas com terapêutica aos 25 principais problemas de saúde levantados na comunidade. O formato didático da horta, representando o corpo humano, serviu como referência às indicações de uso de cada espécie. A horta foi mantida até meados de 2012 na Barra e transferida ao IFMURIAÉ, em área de cultivo agroecológico, no Bairro Sofoco, onde se realizam as práticas do curso de técnico em agroecologia. A comunidade da Barra auxiliou desde as primeiras ações, sendo atuante na colheita das plantas medicinais. As plantas coletadas foram levadas a sala anexa à Paróquia local onde se realizou o processamento pós-colheita e o preparo de fitoterápicos. A dispensação dos preparados foi em outra sala cedida pela Paróquia. As formas fitoterápicas disponibilizadas à população foram de uso interno (erva seca, tintura, xarope e externo (creme, gel, pomada, sendo as mais procuradas: gel, tintura e xarope. De 2006 a 2012 foram  32.400 atendimentos, média de 385 pessoas/mês. O sucesso do projeto se reflete no aumento do número de espécies utilizadas, passando de 40 espécies em 2006 para 170 espécies em 2012, dentre elas: alecrim de jardim (Rosmarinus officinalis, alfavaca (Ocimum basilicum, amora (Morus alba, arnica brasileira (Solidago microglossa, calêndula (Calendula officinalis, camomila (Matricaria chamomilla, capim gordura (Melinis minutiflora, cavalinha (Equisetum arvense, chapéu-de-couro (Echinodorus grandiflorus e espinheira santa (Maytenus aquifolium.

Plants of Haiti used as antifertility agents.

Science.gov (United States)

Weniger, B; Haag-Berrurier, M; Anton, R

1982-07-01

Haitian empirical medicine sprang from both European (16th to 19th century) and African (especially voodoo) traditional therapies. The use of medicinal herbs is highly developed. Our purpose was to list the plants held to be antifertility agents in the island. We identified about twenty species more or less currently used by the women as abortifacients or emmenagogues. The chemistry and active components of a few species are well-known. However, for most of them, some were partially studied, and no relation could be established between their chemical composition and their potential activities, and the rest are chemically unknown. We chemically screened extracts of Casearia ilicifolia, Eleutherine bulbosa, Rhoeo spathacea and Stemodia durantifolia, and identified flavonoids, triterpenes and sterols in the leaves of C. ilicifolia, and naphthoquinones, and a new anthraquinone, anthracene-9,10-dione-1,5-diol-4-methoxy-3-methyl-2-carboxylic acid methyl ester, in the bulbs of E, bulbosa. R. spathacea showed a stimulative activity on mouse uterus. Antifertility screening tests of C. ilicifolia and E. bulbosa showed activity in rats, but also probably toxicity.

Parametri za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati

Directory of Open Access Journals (Sweden)

Liljana Ugrinova

2002-03-01

Full Text Available Napraven e pregled na parametrite za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati. Za procena na kvalitetot na ispituvaniot materijal bea izvrseni fizicki, hemiski i bioloski ispituvanja spored postapkite dadeni vo Ph. Eur., DIN i spored DIN ISO standardite. Baranjata za kvalitet na ovoj vid ambalaza propisani spored Ph. Eur., DIN i DIN ISO standardite se razlikuvaat vo odnos na predvidenite parametri za fizicki, za hemiski i za bioloski ispituvanja. Isto taka, propisani se i razlicni granici na dozvoleno otstapuvanje na oddelni parametri.

Načrtovan porod na domu

OpenAIRE

Todorović, Tamara; Takač, Iztok

2017-01-01

Izhodišča: Porod na domu je sicer star toliko kot človeštvo, pa vendar v veliki večini srednje in visoko razvitih držav prevladuje mnenje, da so zaradi nepredvidljivosti zapletov porodnišnice najbolj varno okolje za rojevanje. Kljub temu obstaja peščica držav, v katerih je porod na domu integriran v sistem zdravstvenega varstva (npr. Nizozemska, Velika Britanija, Kanada). Pri porodih na domu ločimo nenačrtovane in načrtovane porode na domu, slednje pa lahko nadalje razdelimo še na porode s sp...

Composição florística e a conservação de floresta secundárias na serra da Cantareira, São Paulo, Brasil. Floristic composition and conservation of old secondary Forest in the serra Cantareira in São Paulo, South-Eastern Brazil.

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Frederico Alexandre Roccia Dal Pozzo ARZOLLA

2011-06-01

Full Text Available Florestas secundárias estão seriamente ameaçadas pela expansão urbana na região metropolitana. Alguns remanescentes são protegidos, principalmente em parques estaduais e municipais, mas a maioria dessas florestas está sob risco de supressão pela contínua expansão de áreas urbanas. O objetivo deste trabalho foi caracterizar a composição florística do componente arbóreo de trecho de floresta, em estágio médio a avançado de regeneração no Parque Estadual da Cantareira, São Paulo (SP. Foram realizadas caminhadas nos traçados antigo e novo da Linha de Transmissão Guarulhos–Anhanguera, num total aproximado de 11 km de extensão. A amostragem foi realizada no período de 2006 a 2010. No levantamento florístico, foram identificadas 179 espécies, pertencentes a 54 famílias e 127 gêneros. As famílias com maior riqueza de espécies foram Fabaceae (19 espécies, Myrtaceae (18, Lauraceae (16 e Rubiaceae (15 e os gêneros mais ricos, Ocotea e Myrcia (6, Eugenia (5 e Maytenus, Mollinedia e Nectandra com quatro espécies cada. Foram registradas dez espécies consideradas ameaçadas de extinção, sendo quatro espécies na lista de São Paulo e seis na lista da IUCN. Uma delas, Mollinedia oligotricha, é considerada presumivelmente extinta. A similaridade florística encontrada com outros remanescentes florestais da Região Metropolitana de São Paulo e arredores variou entre 11% a 38%. Florestas secundárias apresentam uma considerável riqueza de espécies, incluindo espécies ameaçadas de extinção. Foram discutidas as pressões incidentes sobre esses remanescentes florestais, bem como possíveis estratégias para a sua conservação.Secondary forests are seriously threatened by urban expansion in the metropolitan region of São Paulo. Some remnants are protected, mainly in state or municipal parks, but most of these forests are in immanent danger of being destroyed by the continual expansion of urban areas. The aim of this

Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for 'new' Mn hyperaccumulators and potential applications in taxonomy.

Science.gov (United States)

Fernando, Denise R; Guymer, Gordon; Reeves, Roger D; Woodrow, Ian E; Baker, Alan J; Batianoff, George N

2009-04-01

The analysis of herbarium specimens has previously been used to prospect for 'new' hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). The resulting data demonstrated (a) up to seven 'new' Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these 'new' Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as 'new' Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible 'new' Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible 'new' subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be followed up by field studies.

Na+-stimulated ATPase of alkaliphilic halotolerant cyanobacterium Aphanothece halophytica translocates Na+ into proteoliposomes via Na+ uniport mechanism

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Soontharapirakkul Kanteera

2010-08-01

Full Text Available Abstract Background When cells are exposed to high salinity conditions, they develop a mechanism to extrude excess Na+ from cells to maintain the cytoplasmic Na+ concentration. Until now, the ATPase involved in Na+ transport in cyanobacteria has not been characterized. Here, the characterization of ATPase and its role in Na+ transport of alkaliphilic halotolerant Aphanothece halophytica were investigated to understand the survival mechanism of A. halophytica under high salinity conditions. Results The purified enzyme catalyzed the hydrolysis of ATP in the presence of Na+ but not K+, Li+ and Ca2+. The apparent Km values for Na+ and ATP were 2.0 and 1.2 mM, respectively. The enzyme is likely the F1F0-ATPase based on the usual subunit pattern and the protection against N,N'-dicyclohexylcarbodiimide inhibition of ATPase activity by Na+ in a pH-dependent manner. Proteoliposomes reconstituted with the purified enzyme could take up Na+ upon the addition of ATP. The apparent Km values for this uptake were 3.3 and 0.5 mM for Na+ and ATP, respectively. The mechanism of Na+ transport mediated by Na+-stimulated ATPase in A. halophytica was revealed. Using acridine orange as a probe, alkalization of the lumen of proteoliposomes reconstituted with Na+-stimulated ATPase was observed upon the addition of ATP with Na+ but not with K+, Li+ and Ca2+. The Na+- and ATP-dependent alkalization of the proteoliposome lumen was stimulated by carbonyl cyanide m - chlorophenylhydrazone (CCCP but was inhibited by a permeant anion nitrate. The proteoliposomes showed both ATPase activity and ATP-dependent Na+ uptake activity. The uptake of Na+ was enhanced by CCCP and nitrate. On the other hand, both CCCP and nitrate were shown to dissipate the preformed electric potential generated by Na+-stimulated ATPase of the proteoliposomes. Conclusion The data demonstrate that Na+-stimulated ATPase from A. halophytica, a likely member of F-type ATPase, functions as an electrogenic Na

Polarization dependence of Na* + Na* associative ionization revisited

NARCIS (Netherlands)

Meijer, H.A.J.; Meulen, H.P. v.d.; Morgenstern, R.; Hertel, I.V.; Meyer, E.; Witte, R.

1986-01-01

The dependence of the associative ionization process Na 3 2P3/2 + Na 3 2P3/2 → Na2+ + e- on the polarization of the laser light used for Na excitation was independently investigated in Utrecht and Berlin. The purpose of this paper is to clarify discrepancies between two other earlier experimental

Pseudo-ternary phase diagram in the Na2O-Na2O2-NaOH system

International Nuclear Information System (INIS)

Saito, Jun-ichi; Tendo, Masayuki; Aoto, Kazumi

1997-10-01

Generally, the phase diagrams are always used to understand the present state of compounds at certain temperature. In order to understand the corrosion behavior of structural material for FBR by main sodium compounds (Na 2 O, Na 2 O 2 and NaOH), it is very important to comprehend the phase diagrams of their compounds. However, only Na 2 O-NaOH pseudo-binary phase diagram had been investigated previously in this system. There is no study of other pseudo-binary or ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system. In this study, in order to clarify the present states of their compounds at certain temperatures, the pseudo-binary and ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system were prepared. A series of thermal analyses with binary and ternary component system has been carried out using the differential scanning calorimetry (DSC). The liquidus temperature and ternary eutectic temperatures were confirmed by these measurements. The beneficial indications for constructing phase diagrams were obtained from these experiments. On the basis of these results, the interaction parameters between compounds which were utilized for the Thermo-Calc calculation were optimized. Thermo-Calc is one of thermodynamic calculation software. Consequently the accurate pseudo-binary and ternary phase diagrams were indicated using the optimized parameters. (author)

Extracellular Na+ levels regulate formation and activity of the NaX/alpha1-Na+/K+-ATPase complex in neuronal cells.

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Emmanuelle eBerret

2014-12-01

Full Text Available MnPO neurons play a critical role in hydromineral homeostasis regulation by acting as sensors of extracellular sodium concentration ([Na+]out. The mechanism underlying Na+-sensing involves Na+-flow through the NaX channel, directly regulated by the Na+/K+-ATPase α1-isoform which controls Na+-influx by modulating channel permeability. Together, these two partners form a complex involved in the regulation of intracellular sodium ([Na+]in. Here we aim to determine whether environmental changes in Na+ could actively modulate the NaX/Na+/K+-ATPase complex activity.We investigated the complex activity using patch-clamp recordings from rat MnPO neurons and Neuro2a cells. When the rats were fed with a high-salt-diet, or the [Na+] in the culture medium was increased, the activity of the complex was up-regulated. In contrast, drop in environmental [Na+] decreased the activity of the complex. Interestingly under hypernatremic condition, the colocalization rate and protein level of both partners were up-regulated. Under hyponatremic condition, only NaX protein expression was increased and the level of NaX/Na+/K+-ATPase remained unaltered. This unbalance between NaX and Na+/K+-ATPase pump proportion would induce a bigger portion of Na+/K+-ATPase-control-free NaX channel. Thus we suggest that hypernatremic environment increases NaX/Na+/K+-ATPase α1-isoform activity by increasing the number of both partners and their colocalization rate, whereas hyponatremic environment down-regulates complex activity via a decrease in the relative number of NaX channels controlled by the pump.

Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for ‘new’ Mn hyperaccumulators and potential applications in taxonomy

Science.gov (United States)

Fernando, Denise R.; Guymer, Gordon; Reeves, Roger D.; Woodrow, Ian E.; Baker, Alan J.; Batianoff, George N.

2009-01-01

Background and Aims The analysis of herbarium specimens has previously been used to prospect for ‘new’ hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. Methods ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). Key Results The resulting data demonstrated (a) up to seven ‘new’ Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these ‘new’ Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Conclusions Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as ‘new’ Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible ‘new’ Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible ‘new’ subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be

A Study of the Distribution of Sodium Cations in the Zeolites NaX, NaY and ZnNaY Using Carbon Monoxide Adsorption and 23Na NMR Techniques

Science.gov (United States)

Seidel, A.; Boddenberg, B.

1995-03-01

The zeolites NaX, NaY, Zn(55)NaY, and Zn(74)NaY were investigated by means of carbon monoxide adsorption and with static and magic angle spinning (MAS) 23Na NMR spectroscopy. The Na+ distribution between the sodalite (ß)- and supercages of the fully hydrated zeolites NaX and NaY were found to agree with XRD results. In the hydrated zinc-exchanged zeolites the Na+ ions almost exclusively populate the ß-cages. The adsorption isotherms of CO in the dehydrated zeolites were analyzed quantitatively to yield the concentrations of Na+ residing in the supercages. The measured static and MAS 23Na NMR spectra were analyzed by comparing their widths and shapes with simulated central transition patterns and yield, inter alia, the concentrations of Na+ associated with the spectrum components. Arguments are put forward that 23Na NMR of dehydrated zeolites is well suited to distinguish Na+ cations in highly symmetric environments and mobile Na+ species from others located on general positions, but further resolution is hardly feasible.

HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

International Nuclear Information System (INIS)

Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

1991-01-01

Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

The effect of Na vapor on the Na content of chondrules

Science.gov (United States)

Lewis, R. Dean; Lofgren, Gary E.; Franzen, Hugo F.; Windom, Kenneth E.

1993-01-01

Chondrules contain higher concentrations of volatiles (Na) than expected for melt droplets in the solar nebula. Recent studies have proposed that chondrules may have formed under non-canonical nebular conditions such as in particle/gas-rich clumps. Such chondrule formation areas may have contained significant Na vapor. To test the hypothesis of whether a Na-rich vapor would minimize Na volatilization reaction rates in a chondrule analog and maintain the Na value of the melt, experiments were designed where a Na-rich vapor could be maintained around the sample. A starting material with a melting point lower that typical chondrules was required to keep the logistics of working with Na volatilization from NaCl within the realm of feasibility. The Knippa basalt, a MgO-rich alkali olivine basalt with a melting temperature of 1325 +/- 5 C and a Na2O content of 3.05 wt%, was used as the chondrule analog. Experiments were conducted in a 1 atm, gas-mixing furnace with the fO2 controlled by a CO/CO2 gas mixture and fixed at the I-W buffer curve. To determine the extent of Na loss from the sample, initial experiments were conducted at high temperatures (1300 C - 1350 C) for duration of up to 72 h without a Na-rich vapor present. Almost all (up to 98%) Na was volatilized in runs of 72 h. Subsequent trials were conducted at 1330 C for 16 h in the presence of a Na-rich vapor, supplied by a NaCl-filled crucible placed in the bottom of the furnace. Succeeding Knudsen cell weight-loss mass-spectrometry analysis of NaCl determined the P(sub Na) for these experimental conditions to be in the 10(exp -6) atm range. This value is considered high for nebula conditions but is still plausible for non-canonical environments. In these trials the Na2O content of the glass was maintained or in some cases increased; Na2O values ranged from 2.62% wt to 4.37% wt. The Na content of chondrules may be controlled by the Na vapor pressure in the chondrule formation region. Most heating events capable

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes.

Science.gov (United States)

Lu, Fang-Min; Hilgemann, Donald W

2017-07-03

Decades ago, it was proposed that Na transport in cardiac myocytes is modulated by large changes in cytoplasmic Na concentration within restricted subsarcolemmal spaces. Here, we probe this hypothesis for Na/K pumps by generating constitutive transsarcolemmal Na flux with the Na channel opener veratridine in whole-cell patch-clamp recordings. Using 25 mM Na in the patch pipette, pump currents decay strongly during continuous activation by extracellular K (τ, ∼2 s). In contradiction to depletion hypotheses, the decay becomes stronger when pump currents are decreased by hyperpolarization. Na channel currents are nearly unchanged by pump activity in these conditions, and conversely, continuous Na currents up to 0.5 nA in magnitude have negligible effects on pump currents. These outcomes are even more pronounced using 50 mM Li as a cytoplasmic Na congener. Thus, the Na/K pump current decay reflects mostly an inactivation mechanism that immobilizes Na/K pump charge movements, not cytoplasmic Na depletion. When channel currents are increased beyond 1 nA, models with unrestricted subsarcolemmal diffusion accurately predict current decay (τ ∼15 s) and reversal potential shifts observed for Na, Li, and K currents through Na channels opened by veratridine, as well as for Na, K, Cs, Li, and Cl currents recorded in nystatin-permeabilized myocytes. Ion concentrations in the pipette tip (i.e., access conductance) track without appreciable delay the current changes caused by sarcolemmal ion flux. Importantly, cytoplasmic mixing volumes, calculated from current decay kinetics, increase and decrease as expected with osmolarity changes (τ >30 s). Na/K pump current run-down over 20 min reflects a failure of pumps to recover from inactivation. Simulations reveal that pump inactivation coupled with Na-activated recovery enhances the rapidity and effectivity of Na homeostasis in cardiac myocytes. In conclusion, an autoregulatory mechanism enhances cardiac Na/K pump activity when

Na+/Ca2+ exchange and Na+/K+-ATPase in the heart

Science.gov (United States)

Shattock, Michael J; Ottolia, Michela; Bers, Donald M; Blaustein, Mordecai P; Boguslavskyi, Andrii; Bossuyt, Julie; Bridge, John H B; Chen-Izu, Ye; Clancy, Colleen E; Edwards, Andrew; Goldhaber, Joshua; Kaplan, Jack; Lingrel, Jerry B; Pavlovic, Davor; Philipson, Kenneth; Sipido, Karin R; Xie, Zi-Jian

2015-01-01

This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field. PMID:25772291

Altered Na+ transport after an intracellular alpha-subunit deletion reveals strict external sequential release of Na+ from the Na/K pump.

Science.gov (United States)

Yaragatupalli, Siddhartha; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

2009-09-08

The Na/K pump actively exports 3 Na(+) in exchange for 2 K(+) across the plasmalemma of animal cells. As in other P-type ATPases, pump function is more effective when the relative affinity for transported ions is altered as the ion binding sites alternate between opposite sides of the membrane. Deletion of the five C-terminal residues from the alpha-subunit diminishes internal Na(+) (Na(i)(+)) affinity approximately 25-fold [Morth et al. (2007) Nature 450:1043-1049]. Because external Na(+) (Na(o)(+)) binding is voltage-dependent, we studied the reactions involving this process by using two-electrode and inside-out patch voltage clamp in normal and truncated (DeltaKESYY) Xenopus-alpha1 pumps expressed in oocytes. We observed that DeltaKESYY (i) decreased both Na(o)(+) and Na(i)(+) apparent affinities in the absence of K(o)(+), and (ii) did not affect apparent Na(o)(+) affinity at high K(o)(+). These results support a model of strict sequential external release of Na(+) ions, where the Na(+)-exclusive site releases Na(+) before the sites shared with K(+) and the DeltaKESYY deletion only reduces Na(o)(+) affinity at the shared sites. Moreover, at nonsaturating K(o)(+), DeltaKESYY induced an inward flow of Na(+) through Na/K pumps at negative potentials. Guanidinium(+) can also permeate truncated pumps, whereas N-methyl-D-glucamine cannot. Because guanidinium(o)(+) can also traverse normal Na/K pumps in the absence of both Na(o)(+) and K(o)(+) and can also inhibit Na/K pump currents in a Na(+)-like voltage-dependent manner, we conclude that the normal pathway transited by the first externally released Na(+) is large enough to accommodate guanidinium(+).

Active transport of Na+ by reconstituted Na,K-ATPase

International Nuclear Information System (INIS)

Boldyrev, A.A.; Svinukhova, I.A.

1987-01-01

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na + by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low [Na + ]/[K + ] ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N 1 -hydroxy-ATP, possessing proton acceptor capacity, and N 1 -methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na + in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective

Investigation on U - O - Na, Pu - O - Na and U,Pu - O - Na phase diagrams

International Nuclear Information System (INIS)

Pillon, S.

1989-03-01

The thermochemical interaction between the nuclear fuel (uranium and plutonium mixed oxides) and the sodium has been investigated and particularly the three phase diagrams: U - O - Na; Pu - O - Na; U,Pu - O - Na. High temperature neutron diffraction, microcalorimetry and powder X-ray diffraction were used for the characterization of the compounds synthetized. This study allowed to complete the knowledge about each of these diagrams and to measure some physical and thermal properties on the compounds. The limits on the modelization of the fuel-sodium interaction are discussed from the results of the UO 2 - Na reaction [fr

Measurement of exchangeable sodium: 22Na or 24Na

International Nuclear Information System (INIS)

Smith, T.; Edmonds, C.J.

1987-01-01

A case is made for the use of 22 Na in low activities in preference to 24 Na for routine diagnostic estimation of exchangeable sodium, and is based chiefly on considerations of availability, cost and radiation dosimetry. A method in which only 37 kBq (1 μCi) 22 Na is administered orally is shown to be sufficiently accurate and to possess distinct advantages in terms of cost and convenience with a committed radiation dose no greater than that for a measurement using 24 Na. (author)

Suppression of Na interstitials in Na-F codoped ZnO

Science.gov (United States)

Huo, Wenxing; Mei, Zengxia; Tang, Aihua; Liang, Huili; Du, Xiaolong

2018-04-01

Controlling the formation of interstitial Na (Nai) self-compensating defects has been a long-term physics problem for effective Na doping in ZnO. Herein, we present an experimental approach to the suppression of Nai defects in ZnO via Na and F codoping under an oxygen-rich condition during the molecular beam epitaxy growth process. It is found that the incorporation of such large numbers of Na and F dopants (˜1020 cm-3) does not cause an obvious influence on the lattice parameters. Hall-effect measurements demonstrate that F doping efficiently raises the Fermi level (EF) of ZnO films, which is expected to make the formation energy of Nai and NaZn increase and decrease, respectively. Most of the Na atoms occupy the substitutional Zn sites, and the formation of Nai is suppressed consequently. Secondary ion mass spectrometry measurements reveal that F and Na atoms are tightly bonded together due to their strong Coulomb interaction. The enhanced deep level emission (DLE) in ZnO:Na-F is ascribed to the considerable amount of isolated Zn vacancy (VZn) defects induced by the elevated EF and the formation of neutral (" separators="| FO + - Na Zn - ) 0 complexes. On the other hand, formation of (" separators="| FO + - VZn 2 - ) - complexes in ZnO:F exhausts most of the isolated Zn vacancies, leading to the disappearance of the DLE band.

OGLAŠEVANJE NA DRUŽBENIH OMREŽJIH NA PRIMERU FACEBOOKA

OpenAIRE

Novak, Martina

2012-01-01

V diplomskem delu obravnavamo družbene medije kot novo priložnost za promocijo in oglaševanje podjetij. Spoznali smo družbena omrežja na splošno in nekaj teh, ki jih uporabljamo tudi v Sloveniji na kratko predstavili. Podrobneje smo se osredotočili na družbeno omrežje Facebook, predvsem na samo spletno stran, njen izgled in storitve, ki jih ponuja uporabnikom. V nalogi je podrobneje opisan Facebook kot orodje za uporabo oglaševanja. Spoznali smo brezplačne in plačljive načine promocije in ogl...

Na+,K+-ATPase Na+ affinity in rat skeletal muscle fiber types

DEFF Research Database (Denmark)

Kristensen, Michael; Juel, Carsten

2010-01-01

Previous studies in expression systems have found different ion activation of the Na(+)/K(+)-ATPase isozymes, which suggest that different muscles have different ion affinities. The rate of ATP hydrolysis was used to quantify Na(+),K(+)-ATPase activity, and the Na(+) affinity of Na(+),K(+)-ATPase...

Crystal structure of Na+, K(+)-ATPase in the Na(+)-bound state.

Science.gov (United States)

Nyblom, Maria; Poulsen, Hanne; Gourdon, Pontus; Reinhard, Linda; Andersson, Magnus; Lindahl, Erik; Fedosova, Natalya; Nissen, Poul

2013-10-04

The Na(+), K(+)-adenosine triphosphatase (ATPase) maintains the electrochemical gradients of Na(+) and K(+) across the plasma membrane--a prerequisite for electrical excitability and secondary transport. Hitherto, structural information has been limited to K(+)-bound or ouabain-blocked forms. We present the crystal structure of a Na(+)-bound Na(+), K(+)-ATPase as determined at 4.3 Å resolution. Compared with the K(+)-bound form, large conformational changes are observed in the α subunit whereas the β and γ subunit structures are maintained. The locations of the three Na(+) sites are indicated with the unique site III at the recently suggested IIIb, as further supported by electrophysiological studies on leak currents. Extracellular release of the third Na(+) from IIIb through IIIa, followed by exchange of Na(+) for K(+) at sites I and II, is suggested.

Meltability in system of K2TaF7-NaF-NaCl-KCl

International Nuclear Information System (INIS)

Kartsev, V.E.; Kovalev, F.V.; Korshunov, B.G.

1975-01-01

Thermographic and visual-polythermal techniques were used to study the meltability in K 2 TaF 7 -NaF-NaCl-KCl system. The tetrahedron-forming sections NaF-NaCl-K 2 TaF 7 xKCl and NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl divide the concentration tetrahedron into three particular tetrahedra: NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl-K 2 TaF 7 , NaF-NaCl-K 2 TaF 7 xKCl-2K 2 TaF 7 xaCl, and NaF-NaCl-KCl-K 2 TaF 7 xKCl. Non-variant equilibrium points in all of the particular four-component systems have been determined

Active transport of Na/sup +/ by reconstituted Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Boldyrev, A.A.; Svinukhova, I.A.

1987-02-20

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na/sup +/ by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low (Na/sup +/)/(K/sup +/) ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N/sub 1/-hydroxy-ATP, possessing proton acceptor capacity, and N/sub 1/-methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na/sup +/ in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective.

Relationship between intracellular Na+ concentration and reduced Na+ affinity in Na+,K+-ATPase mutants causing neurological disease

DEFF Research Database (Denmark)

Toustrup-Jensen, Mads Schak; Einholm, Anja P.; Schack, Vivien

The neurological disorders familial hemiplegic migraine type 2 (FHM2), alternating hemiplegia of childhood (AHC), and rapid-onset dystonia parkinsonism (RDP) are caused by mutations of Na+,K+-ATPase α2 and α3 isoforms, expressed in glial and neuronal cells, respectively. Although these disorders......, addressing the question to what extent they cause a change of the intracellular Na+ and K+ concentrations ([Na+]i and [K+]i) in COS cells. C-terminal extension mutants generally showed dramatically reduced Na+ affinity without disturbance of K+ binding, as did other RDP mutants. No phosphorylation from ATP...

MOŽNOSTI VSTOPA NA TUJE TRGE NA PRIMERU PODJETJA AWOODTURE

OpenAIRE

Orličnik, Urša

2014-01-01

Danes pojavljanje podjetja samo na domačem trgu ni več dovolj. Spremembe okolja, naraščanje konkurence ter hiter tehnološki napredek, silijo podjetja k nenehnemu prilagajanju in iskanju novih priložnosti tako na domačem kot tudi na tujem trgu. Internacionalizacija podjetja tako postaja vedno bolj pomemembna za preživetje podjetja. Internacionalizacija se v najširšem smislu nanaša na vse oblike mednarodnega ekonomskega sodelovanja. Je dinamičen proces, kateremu nujno sledi sprememba stanja...

2018-05-09T13:20:33Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

article/67957 2018-05-09T13:20:33Z ajtcam:ART Medicinal Plants Traditionally Used In Mali for Dysmenorrhea Sanogo, R Dysmenorrhea; Maytenus senegalensis; Stereospermum kunthianum; Trichilia emetica; Mali Dysmenorrhea is painful ...

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes

OpenAIRE

Lu, Fang-Min; Hilgemann, Donald W.

2017-01-01

The Na/K pump exports cytoplasmic Na ions while importing K ions, and its activity is thought to be affected by restricted intracellular Na diffusion in cardiac myocytes. Lu and Hilgemann find instead that the pump can enter an inactivated state and that inactivation can be relieved by cytoplasmic Na.

Antimicrobial activity of some medicinal barks used in Peruvian Amazon.

Science.gov (United States)

Kloucek, P; Svobodova, B; Polesny, Z; Langrova, I; Smrcek, S; Kokoska, L

2007-05-04

The aim of this study was to evaluate the antimicrobial activity of six barks traditionally used in Callería District (Ucayali Department, Peru) for treating conditions likely to be associated with microorganisms. Ethanol extracts of stem barks of Abuta grandifolia (Menispermaceae), Dipteryx micrantha (Leguminosae), Cordia alliodora (Boraginaceae), Naucleopsis glabra (Moraceae), Pterocarpus rohrii (Leguminosae), and root bark of Maytenus macrocarpa (Celastraceae) were tested against nine bacteria and one yeast using the broth microdilution method. All plants possessed significant antimicrobial effect, however, the extract of Naucleopsis glabra exhibited the strongest activity against Gram-positive bacteria (MICs ranging from 62.5 to 125 microg/ml), while the broadest spectrum of action was shown by the extract of Maytenus macrocarpa, which inhibited all the strains tested with MICs ranging from 125 to 250 microg/ml.

Vpliv toplotnih mostov na porabo energije za ogrevanje na primeru osnovne šole

OpenAIRE

Megušar, Primož

2015-01-01

Na primeru Osnovne šole Dobrova sem preveril, kakšen vpliv imajo dejanski toplotni mostovi na porabo energije za ogrevanje. Iz načrtov stavbe sem evidentiral vse toplotne mostove, kateri vplivajo na porabo energije. Tem toplotnim mostovom sem nato v standardu SIST EN ISO 14683 poiskal ustrezne približke. Nato sem s programom TOST izvedel tri simulacije. V prvem primeru toplotnih mostov nisem upošteval. V drugem primeru sem toplotne mostove upošteval na poenostavljen način, v zadnjem primeru p...

Na and K dependence of the Na/K pump in cystic fibrosis fibroblasts.

OpenAIRE

Reznik, V M; Schneider, J A; Mendoza, S A

1981-01-01

The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fi...

Vliv mikroflóry na senzorické vlastnosti vína

OpenAIRE

Petrášová, Ludmila

2014-01-01

Tato bakalářská práce se zabývá vlivem mikroflóry na senzorické vlastnosti vína. Teoretická část informuje o botanickém popisu hroznů vína Veltlínské zelené, dále o jeho složení, o technologii zpracování bílého vína a o vlivu kvasinek na aromatický profil vína. V další části popisuje metodu stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s mikroextrakcí tuhou fází (SPME-GC). Cílem experimentální části bylo proměřit vzorky 4 různých moštů odrůdy Veltlínské zelené...

O Complexo Vegetacional da Zona Litorânea no Ceará: Pecém, São Gonçalo do Amarante The vegetation complex of the coastal zone of Ceará: Pecém, São Gonçalo do Amarante

Directory of Open Access Journals (Sweden)

Antônio Sérgio Farias Castro

2012-03-01

Full Text Available O Litoral Setentrional do Nordeste (LSN por sua localização geográfica apresenta clima mais quente e seco do que na costa leste do Brasil. Por sua proximidade com a caatinga e o cerrado, o LSN permite a co-existência de espécies destes Domínios conjuntamente com espécies de restinga, em diferentes formações, constituindo um Complexo Vegetacional. Apesar da grande importância ecológica e botânica deste ecótono, existem poucos estudos sobre a flora regional. O objetivo deste trabalho foi aprofundar o conhecimento sobre a composição florística e fitossociológica da região. Para isso, fizemos um levantamento florístico na área (entre 2007-2011, bem como consultas a registros de herbário na região e um levantamento fitossociológico em um trecho da floresta estacional semidecídua costeira (mata de tabuleiro. Foram inventariadas 382 espécies vegetais, pertencentes a 96 famílias. Na parcela fitossociológica (0,32 ha foram registrados 2.970 indivíduos de 52 espécies, sendo as mais abundantes as arbóreas Manilkara triflora, Chamaecrista ensiformis e Guapira nitida e as arbustivas Cordiera sessilis e Maytenus erythroxyla (altura média 3,8 m, diâmetro médio 6,2 cm, área basal 39,28 m²/ha. A flora local inclui elementos florísticos de caatinga, cerrado e restinga, sugerindo que a comunidade vegetal na região costeira do Ceará possui natureza ecotonal.Due to its geographical location, the northeastern Coast of Brazil (Litoral Setentrional do Nordeste - LSN is a hotter and drier climate than the eastern coast. In addition, because of its proximity to caatinga and cerrado, the LSN contains species from these vegetation biomes and from the restinga on the coast, which comprise different plant formations and creates a vegetation complex. Despite the great importance of this ecotone, there are few studies about its flora. The objective of this work was to contribute to what is known about the floristic and phytosociological

Study of the Na-C-O and Na-H-O ternary systems in the sodium rich corner

International Nuclear Information System (INIS)

Maupre, J.-P.

1978-02-01

The purpose of this study is to provide a contribution to the understanding of the sodium - carbon - oxygen and sodium - hydrogen - oxygen ternary systems in the sodium rich corner. In order to do this the Na-NaH-Na 2 O-NaOH phase diagram was completed and the Na-Na 2 O-Na 2 CO 3 -C phase diagram was outlined. This work is made up of two parts. The first is devoted to a critical literature survey essential to establish correct phase diagrams. The second is an experimental study followed by a discussion collating our finding to the literary data. The basic experimental technique used is differential thermal analysis (DTA) but it has been completed by quenching, X-ray and chemical analysis methods. The proposed phase diagrams imply that Na-NaH-Na 2 O-NaOH and Na-Na 2 O-Na 2 CO 3 -C systems are reciprocal ternary systems. Temperatures of stable pairs reversal are respectively 410 and 690 0 C. The stable pairs are Na-NaOH and Na-Na 2 CO 3 at elevated temperature, Na 2 O-NaH and Na 2 O-C at low temperature [fr

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions.

Science.gov (United States)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

2017-06-01

Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the subsequent rate of repletion. The rate of Na depletion and subsequent rate of Na repletion with two levels of dietary Na to lactating dairy cows housed under tropical conditions were investigated using the salivary Na/K. The 12 lactating cows (salivary Na/K ratio 14.6) rapidly developed clinical signs of Na deficiency, including pica, polyuria and polydipsia, reduced body weight and reduced milk yield when fed a low-Na ration (0.33 g kg -1 dry matter (DM)) for 3 weeks. Deficiency symptoms were associated with a rapid decrease in salivary Na/K ratio to cows with NaCl to a ration concentration of 1.1 or 1.6 g Na kg -1 DM for 5 weeks did not restore salivary Na/K ratio to values of >6. A daily Na intake of heat-stressed lactating cows to a ration intake of 1.6 g Na kg -1 DM was insufficient to restore Na deficiency. One week was sufficient to deplete heat-stressed lactating cows of Na, allowing for rapid dose-response studies utilizing the salivary Na/K ratio as a parameter for Na status of cows under tropical conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

Science.gov (United States)

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J.; Rasmussen, Helge H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no known physical barriers that account for such restricted Na+ diffusion, and we examined if changes of activity of the Na+-K+ pump itself cause the transient peak current. Reexposure to K+ reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na+ concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K+-free pipette solution could not be reconciled with restricted subsarcolemmal Na+ diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na+- and K+ concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na+-K+ pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na+-K+ pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K+-induced peak Na+-K+ pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K+-induced peak Na+-K+ pump current reflects the effect of conformation-dependent β1 pump subunit

Glutathionylation-Dependence of Na(+)-K(+)-Pump Currents Can Mimic Reduced Subsarcolemmal Na(+) Diffusion.

Science.gov (United States)

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J; Rasmussen, Helge H

2016-03-08

The existence of a subsarcolemmal space with restricted diffusion for Na(+) in cardiac myocytes has been inferred from a transient peak electrogenic Na(+)-K(+) pump current beyond steady state on reexposure of myocytes to K(+) after a period of exposure to K(+)-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na(+) that accumulated in the diffusion-restricted space during pump inhibition in K(+)-free extracellular solution. However, there are no known physical barriers that account for such restricted Na(+) diffusion, and we examined if changes of activity of the Na(+)-K(+) pump itself cause the transient peak current. Reexposure to K(+) reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na(+) concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K(+)-free pipette solution could not be reconciled with restricted subsarcolemmal Na(+) diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na(+)- and K(+) concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na(+)-K(+) pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na(+)-K(+) pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K(+)-induced peak Na(+)-K(+) pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K(+)-induced peak Na(+)-K(+) pump current reflects the effect

Crystal structure of a Na+-bound Na+,K+-ATPase preceding the E1P state.

Science.gov (United States)

Kanai, Ryuta; Ogawa, Haruo; Vilsen, Bente; Cornelius, Flemming; Toyoshima, Chikashi

2013-10-10

Na(+),K(+)-ATPase pumps three Na(+) ions out of cells in exchange for two K(+) taken up from the extracellular medium per ATP molecule hydrolysed, thereby establishing Na(+) and K(+) gradients across the membrane in all animal cells. These ion gradients are used in many fundamental processes, notably excitation of nerve cells. Here we describe 2.8 Å-resolution crystal structures of this ATPase from pig kidney with bound Na(+), ADP and aluminium fluoride, a stable phosphate analogue, with and without oligomycin that promotes Na(+) occlusion. These crystal structures represent a transition state preceding the phosphorylated intermediate (E1P) in which three Na(+) ions are occluded. Details of the Na(+)-binding sites show how this ATPase functions as a Na(+)-specific pump, rejecting K(+) and Ca(2+), even though its affinity for Na(+) is low (millimolar dissociation constant). A mechanism for sequential, cooperative Na(+) binding can now be formulated in atomic detail.

Na+-H+ exchange and Na+-dependent transport systems in streptozotocin diabetic rat kidneys

International Nuclear Information System (INIS)

El-Seifi, S.; Freiberg, J.M.; Kinsella, F.J.; Cheng, L.; Sacktor, B.

1987-01-01

The streptozotocin-induced diabetic rat was used to test the hypothesis that Na + -H + exchange activity in the proximal tubule luminal membrane would be increased in association with renal hypertrophy, altered glomerular hemodynamics, enhanced filtered load and tubular reabsorption of 22 Na + , and stimulated 22 Na= pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H + gradient-dependent Na + uptake and Na + gradient-dependent H + flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na + gradient-dependent uptakes of phosphate, D-glucose, L-proline, and myoinositol were decreased in the drug-induced diabetic animals. These membrane transport alterations were not found when the streptozotocin-diabetic animals were treated with insulin

The two C-terminal tyrosines stabilize occluded Na/K pump conformations containing Na or K ions.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2010-07-01

Interactions of the three transported Na ions with the Na/K pump remain incompletely understood. Na/K pump crystal structures show that the extended C terminus of the Na,K-adenosine triphosphatase (ATPase) alpha subunit directly contacts transmembrane helices. Deletion of the last five residues (KETYY in almost all Na/K pumps) markedly lowered the apparent affinity for Na activation of pump phosphorylation from ATP, a reflection of cytoplasmic Na affinity for forming the occluded E1P(Na3) conformation. ATPase assays further suggested that C-terminal truncations also interfere with low affinity Na interactions, which are attributable to extracellular effects. Because extracellular Na ions traverse part of the membrane's electric field to reach their binding sites in the Na/K pump, their movements generate currents that can be monitored with high resolution. We report here electrical measurements to examine how Na/K pump interactions with extracellular Na ions are influenced by C-terminal truncations. We deleted the last two (YY) or five (KESYY) residues in Xenopus laevis alpha1 Na/K pumps made ouabain resistant by either of two kinds of point mutations and measured their currents as 10-mM ouabain-sensitive currents in Xenopus oocytes after silencing endogenous Xenopus Na/K pumps with 1 microM ouabain. We found the low affinity inhibitory influence of extracellular Na on outward Na/K pump current at negative voltages to be impaired in all of the C-terminally truncated pumps. Correspondingly, voltage jump-induced transient charge movements that reflect pump interactions with extracellular Na ions were strongly shifted to more negative potentials; this signals a several-fold reduction of the apparent affinity for extracellular Na in the truncated pumps. Parallel lowering of Na affinity on both sides of the membrane argues that the C-terminal contacts provide important stabilization of the occluded E1P(Na3) conformation, regardless of the route of Na ion entry into the

Celastraceae—I

NARCIS (Netherlands)

Hou, Ding

1960-01-01

Trees, erect or scandent shrubs; stems sometimes producing rootlets ( Euonymus spp.), rarely buttressed at the base (e.g. Bhesa) or with aerophores (Lophopetalum multinervium), sometimes thorny (Maytenus spp.) ; sometimes with elastic or resinous threads in the leaves, inflorescences, floral parts,

Avaliação da inibição da acetilcolinesterase por extratos de plantas medicinais Evaluation of acetylcholinesterase inhibition by extracts from medicinal plants

Directory of Open Access Journals (Sweden)

W.M. Mota

2012-01-01

Full Text Available Neste trabalho foi avaliada a atividade inibitória da acetilcolinesterase (AChE pelo método de Ellman, modificado por Rhee, de extratos aquosos e etanólicos de oito plantas utilizadas na medicina popular da região Nordeste do Brasil. O extrato aquoso de E. velutina não apresentou atividade inibitória enquanto o extrato aquoso de Maytenus rigida apresentou baixa atividade inibitória (percentual de inibição de 4%. Detectou-se atividade inibitória moderada com o extrato aquoso de P. piperoides (percentual de inibição de 40 %, enquanto o extrato de V. agnus-castus L. inibiu 74% da atividade da AChE, caracterizando-se como potente atividade inibitória. A avaliação da inibição da AChE com os extratos etanólicos demonstrou que os extratos de Sideroxylon obtusifolium, Erythrina velutina, Vitex agnus-castus, Phoradendron piperoides, Chrysobalanus icaco, Bauhinia cheilantha e Orbignya phalerata não apresentaram atividade inibitória. Baixa atividade inibitória foi observada com os extratos etanólicos de Maytenus rigida (percentual de inibição de 7% e de Hyptis fruticosa (percentual de inibição de 11%. O extrato etanólico de Moringa oleifera apresentou atividade inibitória moderada, inibindo 47% da atividade dessa enzima. Nenhum dos extratos etanólicos testados apresentou atividade inibitória potente da AChE. Os resultados dos estudos de inibição da acetilcolinesterase permitem concluir que o extrato aquoso de V. agnus-castus L. mostrou-se o mais eficaz quanto a inibição da AChE. Este resultado reforça a necessidade da continuidade do estudo desse extrato, de forma a realizar a partição do extrato e a purificação das frações para isolar a molécula responsável pela inibição observada.In this study, we evaluated the inhibitory activity against acetylcholinesterase (AChE according to Ellman's method, modified by Rhee, for ethanol and aqueous extracts from eight plants used in folk medicine in the northeast region of

Anion-coupled Na efflux mediated by the human red blood cell Na/K pump

International Nuclear Information System (INIS)

Dissing, S.; Hoffman, J.F.

1990-01-01

The red cell Na/K pump is known to continue to extrude Na when both Na and K are removed from the external medium. Because this ouabain-sensitive flux occurs in the absence of an exchangeable cation, it is referred to as uncoupled Na efflux. This flux is also known to be inhibited by 5 mM Nao but to a lesser extent than that inhibitable by ouabain. Uncoupled Na efflux via the Na/K pump therefore can be divided into a Nao-sensitive and Nao-insensitive component. We used DIDS-treated, SO4-equilibrated human red blood cells suspended in HEPES-buffered (pHo 7.4) MgSO4 or (Tris)2SO4, in which we measured 22Na efflux, 35SO4 efflux, and changes in the membrane potential with the fluorescent dye, diS-C3 (5). A principal finding is that uncoupled Na efflux occurs electroneurally, in contrast to the pump's normal electrogenic operation when exchanging Nai for Ko. This electroneutral uncoupled efflux of Na was found to be balanced by an efflux of cellular anions. (We were unable to detect any ouabain-sensitive uptake of protons, measured in an unbuffered medium at pH 7.4 with a Radiometer pH-STAT.) The Nao-sensitive efflux of Nai was found to be 1.95 +/- 0.10 times the Nao-sensitive efflux of (SO4)i, indicating that the stoichiometry of this cotransport is two Na+ per SO4=, accounting for 60-80% of the electroneutral Na efflux. The remainder portion, that is, the ouabain-sensitive Nao-insensitive component, has been identified as PO4-coupled Na transport and is the subject of a separate paper. That uncoupled Na efflux occurs as a cotransport with anions is supported by the result, obtained with resealed ghosts, that when internal and external SO4 was substituted by the impermeant anion, tartrate i,o, the efflux of Na was inhibited 60-80%. This inhibition could be relieved by the inclusion, before DIDS treatment, of 5 mM Cli,o

Na5NbO5 and Na5TaO5 phases

International Nuclear Information System (INIS)

Darriet, J.; Maazaz, A.; Bouloux, J.C.; Delmas, C.

1982-01-01

New ternary oxides of formulas Na 5 NbO 5 and Na 5 TaO 5 have been prepared. They crystallize in the monoclinic system (space group C2/c). The crystal structure of Na 5 NbO 5 has been determined. It derives from a NaCl-type structure by ordering of the cations and of the oxygen vacancies in the anionic sublattice, the corresponding formula being Nasub(5/6)Nbsub(1/6)Osub(5/6)vacant sub(1/6). Sodium and niobium have a distorted square-pyramidal surrounding. (author)

Synthesis of Na-A and/or Na-X zeolite/porous carbon composites from carbonized rice husk

International Nuclear Information System (INIS)

Katsuki, Hiroaki; Komarneni, Sridhar

2009-01-01

Na-A and/or Na-X zeolite/porous carbon composites were prepared under hydrothermal conditions by NaOH dissolution of silica first from carbonized rice husk followed by addition of NaAlO 2 and in situ crystallization of zeolites i.e., using a two-step process. When a one-step process was used, both Na-A and Na-X zeolites crystallized on the surface of carbon. Na-A or Na-X zeolite crystals were prepared on the porous carbonized rice husk at 90 deg. C for 2-6 h by changing the SiO 2 /Al 2 O 3 , H 2 O/Na 2 O and Na 2 O/SiO 2 molar ratios of precursors in the two-step process. The surface area and NH 4 + -cation exchange capacity (CEC) of Na-A zeolite/porous carbon were found to be 171 m 2 /g and 506 meq/100 g, respectively, while those of Na-X zeolite/porous carbon composites were 676 m 2 /g and 317 meq/100 g, respectively. Na-A and Na-X zeolites are well-known microporous and hydrophilic materials while carbonized rice husk was found to be mesoporous (pores of ∼3.9 nm) and hydrophobic. These hybrid microporous-mesoporous and hydrophilic-hydrophobic composites are expected to be useful for decontamination of metal cations as well as organic contaminants simultaneously. - Graphical Abstract: Novel Na-X zeolite/porous carbon composite.

Equilibrium chemical transformations in NaPO3 + NaCl melts

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Rodionov, Yu.I.

1988-01-01

Because of the problems of the burial of solidified radioactive wastes into different geological rock formations, in particular into massives of rock-salt, the state of molten polyphosphate-chloride mixtures (taking into account the chemical character of the interaction of their components) for a prolonged period of time. The equilibrium products of the reaction in the NaPO 3 -NaCl system were studied in melts in air in the composition range of 30-70 mole % NaCl. It was shown that with increase in the NaCl content in the mixtures, the polyphosphate gradually depolymerizes to sodium tri-, di-, and monophosphates, and the composition of the equilibrium melts is dependent only on the ratio between the components in the initial molten mixtures. The time until the equilibrium is attained is shorter, the higher is the experimental temperature

Long-Range Effects of Na(+) Binding in Na,K-ATPase Reported by ATP.

Science.gov (United States)

Middleton, David A; Fedosova, Natalya U; Esmann, Mikael

2015-12-01

This paper addresses the question of long-range interactions between the intramembranous cation binding sites and the cytoplasmic nucleotide binding site of the ubiquitous ion-transporting Na,K-ATPase using (13)C cross-polarization magic-angle spinning (CP-MAS) solid-state nuclear magnetic resonance. High-affinity ATP binding is induced by the presence of Na(+) as well as of Na-like substances such as Tris(+), and these ions are equally efficient promoters of nucleotide binding. CP-MAS analysis of bound ATP with Na,K-ATPase purified from pig kidney membranes reveals subtle differences in the nucleotide interactions within the nucleotide site depending on whether Na(+) or Tris(+) is used to induce binding. Differences in chemical shifts for ATP atoms C1' and C5' observed in the presence of Na(+) or Tris(+) suggest alterations in the residues surrounding the bound nucleotide, hydrogen bonding, and/or conformation of the ribose ring. This is taken as evidence of a long-distance communication between the Na(+)-filled ion sites in the membrane interior and the nucleotide binding site in the cytoplasmic domain and reflects the first conformational change ultimately leading to phosphorylation of the enzyme. Stopped-flow fluorescence measurements with the nucleotide analogue eosin show that the dissociation rate constant for eosin is larger in Tris(+) than in Na(+), giving kinetic evidence of the difference in structural effects of Na(+) and Tris(+). According to the recent crystal structure of the E1·AlF4(-)·ADP·3Na(+) form, the coupling between the ion binding sites and the nucleotide side is mediated by, among others, the M5 helix.

Interaction between Na+/K+-pump and Na+/Ca2+-exchanger modulates intercellular communication.

Science.gov (United States)

Matchkov, Vladimir V; Gustafsson, Helena; Rahman, Awahan; Briggs Boedtkjer, Donna M; Gorintin, Sarah; Hansen, Anne Kirstine; Bouzinova, Elena V; Praetorius, Helle A; Aalkjaer, Christian; Nilsson, Holger

2007-04-13

Ouabain, a specific inhibitor of the Na(+)/K(+)-pump, has previously been shown to interfere with intercellular communication. Here we test the hypothesis that the communication between vascular smooth muscle cells is regulated through an interaction between the Na(+)/K(+)-pump and the Na(+)/Ca(2+)-exchanger leading to an increase in the intracellular calcium concentration ([Ca(2+)](i)) in discrete areas near the plasma membrane. [Ca(2+)](i) in smooth muscle cells was imaged in cultured rat aortic smooth muscle cell pairs (A7r5) and in rat mesenteric small artery segments simultaneously with force. In A7r5 coupling between cells was estimated by measuring membrane capacitance. Smooth muscle cells were uncoupled when the Na(+)/K(+)-pump was inhibited either by a low concentration of ouabain, which also caused a localized increase of [Ca(2+)](i) near the membrane, or by ATP depletion. Reduction of Na(+)/K(+)-pump activity by removal of extracellular potassium ([K(+)](o)) also uncoupled cells, but only after inhibition of K(ATP) channels. Inhibition of the Na(+)/Ca(2+)-exchange activity by SEA0400 or by a reduction of the equilibrium potential (making it more negative) also uncoupled the cells. Depletion of intracellular Na(+) and clamping of [Ca(2+)](i) at low concentrations prevented the uncoupling. The experiments suggest that the Na(+)/K(+)-pump may affect gap junction conductivity via localized changes in [Ca(2+)](i) through modulation of Na(+)/Ca(2+)-exchanger activity.

Caracterización palinológica de la familia Celastraceae para Colombia

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Bogotá A. R. Giovanni

2001-07-01

Full Text Available La caracterización palinológica de especies de los siete géneros de Celastraceae con área de distribución en Colombia permitió establecer de manera general el comportamiento estenopalinológico de la misma; los granos de polen son mónadas, isopolares, radiosimétricas; oblados esferoidales o suboblados; tricolporados con exina semitectada microreticulada o reticulada (58%. Las endoaberturas son lalongadas en el 92 % de los casos, la disminución en el espesor de la exina cerca a los colpos es común para casi todos los taxones examinados. Excepciones a este patrón se encuentran en Maytenus longipes pro lado esferoidal; Celastrus colombianus endoaberturas lolongadas; Gymnosp oria gentryi; Zinowiewia australis y Crossopetalum panamense que presentan costilla. Maytenus novogranatensis y Goupia glabra tienen exina tectada perforada, en las especies de Perrottetia la exina es tectada foveolada o fosulada. Perrotttetia y Goupia son los géneros mas disímiles al interior de la familia, condición que igualmente se presenta en la morfología macroscópica. Las características polínicas de Goupia refuerzan la opción de separarla de Celastraceae para estructurar la familia Goupiaceae.The palinological characterization of species of the seven genus of Celastraceae with distribution in Colombia allowed us to establish, in a general way, its stenopalynological behavior; the pollen grains are monads, isopolares radially symmetric; oblate spheroidal or suboblate; tricolporate, with semitectate exine, reticulate or microreticulate in 58%. The endoapertures are lalongate in 92% ofthe cases, the decrease in the exine thickness near the colpus is common to all the taxa. Some exceptions are found in Maytenus longipes prolate spheroidal; Celastrus colombianus lolongate endoapertures; Gymnosporia gentryi, Zinowiewia australis and Crossopetalum panamense costa. Maytenus novogranatensis and Goupia glabra have tectate exine, foveolate o fosulate. Perrottetia

Intracellular Na(+) and metabolic modulation of Na/K pump and excitability in the rat suprachiasmatic nucleus neurons.

Science.gov (United States)

Wang, Yi-Chi; Yang, Jyh-Jeen; Huang, Rong-Chi

2012-10-01

Na/K pump activity and metabolic rate are both higher during the day in the suprachiasmatic nucleus (SCN) that houses the circadian clock. Here we investigated the role of intracellular Na(+) and energy metabolism in regulating Na/K pump activity and neuronal excitability. Removal of extracellular K(+) to block the Na/K pump excited SCN neurons to fire at higher rates and return to normal K(+) to reactivate the pump produced rebound hyperpolarization to inhibit firing. In the presence of tetrodotoxin to block the action potentials, both zero K(+)-induced depolarization and rebound hyperpolarization were blocked by the cardiac glycoside strophanthidin. Ratiometric Na(+) imaging with a Na(+)-sensitive fluorescent dye indicated saturating accumulation of intracellular Na(+) in response to pump blockade with zero K(+). The Na(+) ionophore monensin also induced Na(+) loading and hyperpolarized the membrane potential, with the hyperpolarizing effect of monensin abolished in zero Na(+) or by pump blockade. Conversely, Na(+) depletion with Na(+)-free pipette solution depolarized membrane potential but retained residual Na/K pump activity. Cyanide inhibition of oxidative phosphorylation blocked the Na/K pump to depolarize resting potential and increase spontaneous firing in most cells, and to raise intracellular Na(+) levels in all cells. Nonetheless, the Na/K pump was incompletely blocked by cyanide but completely blocked by iodoacetate to inhibit glycolysis, indicating the involvement of both oxidative phosphorylation and glycolysis in fueling the Na/K pump. Together, the results indicate the importance of intracellular Na(+) and energy metabolism in regulating Na/K pump activity as well as neuronal excitability in the SCN neurons.

Synthesis of zeolites Na-A and Na-X from tablet compressed and calcinated coal fly ash

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Hu, Tao; Gao, Wenyan; Liu, Xin; Zhang, Yifu; Meng, Changgong

2017-10-01

Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace the conventionally used sodium silicate and aluminate for zeolite synthesis. We used Na2CO3 to replace the expensive NaOH used for the calcination of CFA and showed that tablet compression can enhance the contact with Na2CO3 for the activation of CFA through calcination for the synthesis of zeolites Na-A and Na-X under mild conditions. We optimized the control variables for zeolite synthesis and showed that phase-pure zeolite Na-A can be synthesized with CFA at reactant molar ratio, hydrothermal reaction temperature and reaction time of 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2O at 80°C for 6 h, respectively, while phase-pure zeolite Na-X can be synthesized at 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2O at 100°C for 8 h, respectively. The composition, morphology, specific surface area, vibration spectrum and thermogravimetry of synthesized Na-A and Na-X were further characterized.

The CERES / NA45 experiment

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Laurent Guiraud

2000-01-01

Ceres is one of the second generation heavy ion experiments at CERN's SPS. It is dedicated to the study of electron-positron pairs in relativistic nuclear collisions. NA45 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN's Heavy Ion programme which provided evidence for the existence of a new state of matter, the quark-gluon plasma. In this state, quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

The rapid-onset dystonia parkinsonism mutation D923N of the Na+, K+-ATPase alpha3 isoform disrupts Na+ interaction at the third Na+ site.

Science.gov (United States)

Einholm, Anja Pernille; Toustrup-Jensen, Mads S; Holm, Rikke; Andersen, Jens Peter; Vilsen, Bente

2010-08-20

Rapid-onset dystonia parkinsonism (RDP), a rare neurological disorder, is caused by mutation of the neuron-specific alpha3-isoform of Na(+), K(+)-ATPase. Here, we present the functional consequences of RDP mutation D923N. Relative to the wild type, the mutant exhibits a remarkable approximately 200-fold reduction of Na(+) affinity for activation of phosphorylation from ATP, reflecting a defective interaction of the E(1) form with intracellular Na(+). This is the largest effect on Na(+) affinity reported so far for any Na(+), K(+)-ATPase mutant. D923N also affects the interaction with extracellular Na(+) normally driving the E(1)P to E(2)P conformational transition backward. However, no impairment of K(+) binding was observed for D923N, leading to the conclusion that Asp(923) is specifically associated with the third Na(+) site that is selective toward Na(+). The crystal structure of the Na(+), K(+)-ATPase in E(2) form shows that Asp(923) is located in the cytoplasmic half of transmembrane helix M8 inside a putative transport channel, which is lined by residues from the transmembrane helices M5, M7, M8, and M10 and capped by the C terminus, recently found involved in recognition of the third Na(+) ion. Structural modeling of the E(1) form of Na(+), K(+)-ATPase based on the Ca(2+)-ATPase crystal structure is consistent with the hypothesis that Asp(923) contributes to a site binding the third Na(+) ion. These results in conjunction with our previous findings with other RDP mutants suggest that a selective defect in the handling of Na(+) may be a general feature of the RDP disorder.

Recikliranje plastenk na kreativen način

OpenAIRE

Pavlin, Suzana

2017-01-01

Plastenke, poleg ostalih plastičnih izdelkov, v zadnjih letih predstavljajo pravo katastrofo za okolje. Domnevamo, da se le redko kdo vpraša, kaj se zgodi z njo po tem, ko je iz nje zaužil še zadnjo kapljico vode. Plastenka je lahko kot večina ostalih komunalnih odpadkov ponovno uporabljena, reciklirana, sežgana ali odložena na deponijo. V primeru nespoštovanja Zakona o varstvu okolja pa pristane v naravi, pogosto v morju, kjer prav počasi razpada in negativno vpliva na celoten ekosistem. V d...

Plant Defensins NaD1 and NaD2 Induce Different Stress Response Pathways in Fungi

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Peter M. Dracatos

2016-09-01

Full Text Available Nicotiana alata defensins 1 and 2 (NaD1 and NaD2 are plant defensins from the ornamental tobacco that have antifungal activity against a variety of fungal pathogens. Some plant defensins interact with fungal cell wall O-glycosylated proteins. Therefore, we investigated if this was the case for NaD1 and NaD2, by assessing the sensitivity of the three Aspergillus nidulans (An O-mannosyltransferase (pmt knockout (KO mutants (An∆pmtA, An∆pmtB, and An∆pmtC. An∆pmtA was resistant to both defensins, while An∆pmtC was resistant to NaD2 only, suggesting NaD1 and NaD2 are unlikely to have a general interaction with O-linked side chains. Further evidence of this difference in the antifungal mechanism was provided by the dissimilarity of the NaD1 and NaD2 sensitivities of the Fusarium oxysporum f. sp. lycopersici (Fol signalling knockout mutants from the cell wall integrity (CWI and high osmolarity glycerol (HOG mitogen-activated protein kinase (MAPK pathways. HOG pathway mutants were sensitive to both NaD1 and NaD2, while CWI pathway mutants only displayed sensitivity to NaD2.

Glutamate Water Gates in the Ion Binding Pocket of Na(+) Bound Na(+), K(+)-ATPase

DEFF Research Database (Denmark)

Han, Minwoo; Kopec, Wojciech; Solov'yov, Ilia A

2017-01-01

III is always protonated. Glutamic acid residues in the three binding sites act as water gates, and their deprotonation triggers water entry to the binding sites. From DFT calculations of Na(+) binding energies, we conclude that three protons in the binding site are needed to effectively bind Na......The dynamically changing protonation states of the six acidic amino acid residues in the ion binding pocket of the Na(+), K(+) -ATPase (NKA) during the ion transport cycle are proposed to drive ion binding, release and possibly determine Na(+) or K(+) selectivity. We use molecular dynamics (MD......(+) from water and four are needed to release them in the next step. Protonation of Asp926 in site III will induce Na(+) release, and Glu327, Glu954 and Glu779 are all likely to be protonated in the Na(+) bound occluded conformation. Our data provides key insights into the role of protons in the Na...

NA62 and NA48/2 results on search for Heavy Neutral Leptons

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Lamanna Gianluca

2018-01-01

Full Text Available In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL with data collected by NA48/2 (2003-2004, NA62-RK (2007 and NA62 (2015 CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

Transmural gradients in Na/K pump activity and [Na+]I in canine ventricle.

Science.gov (United States)

Gao, J; Wang, W; Cohen, I S; Mathias, R T

2005-09-01

There are well-documented differences in ion channel activity and action potential shape between epicardial (EPI), midmyocardial (MID), and endocardial (ENDO) ventricular myocytes. The purpose of this study was to determine if differences exist in Na/K pump activity. The whole cell patch-clamp was used to measure Na/K pump current (I(P)) and inward background Na(+)-current (I(inb)) in cells isolated from canine left ventricle. All currents were normalized to membrane capacitance. I(P) was measured as the current blocked by a saturating concentration of dihydro-ouabain. [Na(+)](i) was measured using SBFI-AM. I(P)(ENDO) (0.34 +/- 0.04 pA/pF, n = 17) was smaller than I(P)(EPI) (0.68 +/- 0.09 pA/pF, n = 38); the ratio was 0.50 with I(P)(MID) being intermediate (0.53 +/- 0.13 pA/pF, n = 19). The dependence of I(P) on [Na(+)](i) or voltage was essentially identical in EPI and ENDO (half-maximal activation at 9-10 mM [Na(+)](i) or approximately -90 mV). Increasing [K(+)](o) from 5.4 to 15 mM caused both I(P)(ENDO) and I(P)(EPI) to increase, but the ratio remained approximately 0.5. I(inb) in EPI and ENDO were nearly identical ( approximately 0.6 pA/pF). Physiological [Na(+)](i) was lower in EPI (7 +/- 2 mM, n = 31) than ENDO (12 +/- 3 mM, n = 29), with MID being intermediate (9 +/- 3 mM, n = 22). When cells were paced at 2 Hz, [Na(+)](i) increased but the differences persisted (ENDO 14 +/- 3 mM, n = 10; EPI 9 +/- 2 mM, n = 10; and MID intermediate, 11 +/- 2 mM, n = 9). Based on these results, the larger I(P) in EPI appears to reflect a higher maximum turnover rate, which implies either a larger number of active pumps or a higher turnover rate per pump protein. The transmural gradient in [Na(+)](i) means physiological I(P) is approximately uniform across the ventricular wall, whereas transporters that utilize the transmembrane electrochemical gradient for Na(+), such as Na/Ca exchange, have a larger driving force in EPI than ENDO.

Reactions of metal oxides with molten NaPO3 + NaCl mixtures

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

We consider the dissolution mechanism for iron (III), europium(III), and tin(IV) oxides in molten NaPO 3 + NaCl that are responsible for the peak solubilities. We chose Fe 2 O 3 as the basic material since this occurs in large amounts around damaged metal structures in rock salt mines in a proposed zone for storing vitrified radioactive wastes. Solubility measurement and paper chromatography show that Fe 2 O 3 dissolves in molten NaPO 3 + NaCl in air by reaction with the solvent to give double iron and sodium diphosphates and monophosphates in accordance with the initial solution-in-the-melt composition, the degree of equilibration, and the temperature. The elevated solubilities for initial NaCl contents close to 30 mole % are due to sodium triphosphates and tricyclophosphates present in these melts. Moessbauer spectroscopy confirms that double iron, europium and tin diphosphates and monophosphates containing sodium occur in these chloride-polyphosphate melts

Na(+),K (+)-ATPase as a docking station: protein-protein complexes of the Na(+),K (+)-ATPase.

Science.gov (United States)

Reinhard, Linda; Tidow, Henning; Clausen, Michael J; Nissen, Poul

2013-01-01

The Na(+),K(+)-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na(+) ions out of the cell and of K(+) ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na(+),K(+)-ATPase, recent work has suggested additional roles for Na(+),K(+)-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na(+),K(+)-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na(+),K(+)-ATPase as a signal transducer, but also briefly discuss other Na(+),K(+)-ATPase protein-protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme.

Characterization of Na+-linked and Na+-independent Cl-/HCO3- exchange systems in Chinese hamster lung fibroblasts

International Nuclear Information System (INIS)

Cassel, D.; Scharf, O.; Rotman, M.; Cragoe, E.J. Jr.; Katz, M.

1988-01-01

The PS120 variant of Chinese hamster lung fibroblasts which lacks Na + /H + exchange activity was used to investigate bicarbonate transport systems and their role in intracellular pH (pH/sub i/) regulation. When pH/sub i/ was decreased by acid load, bicarbonate caused pH/sub i/ increase and stimulated 36 Cl - efflux from the cells, both in a Na + -dependent manner. These results together with previous findings that bicarbonate stimulates 22 Na + uptake in PS120 cells demonstrate the presence of a Na + -linked Cl - /HCO 3 - exchange system. In cells with normal initial pH/sub i/, bicarbonate caused Na + -independent pH/sub i/ increase in Cl - -free solutions and stimulated Na + -independent 36 Cl - efflux, indicating that a Na + -independent Cl - /HCO 3 - exchanger is also present in the cell. Na + -linked and Na + -independent Cl - /HCO 3- exchange is apparently mediated by two distinct systems, since a [(tetrahydrofluorene-7-yl)oxy]acetic acid derivative selectively inhibits the Na + -independent exchanger. An additional distinctive features is a 10-fold lower affinity for chloride of the Na + -linked exchanger. The Na + -linked and Na + -independent Cl - /HCO 3 - exchange systems are likely to protect the cell from acid and alkaline load, respectively

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy

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Cassiano Felippe Gonçalves-de-Albuquerque

2017-04-01

Full Text Available Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy.

Science.gov (United States)

Felippe Gonçalves-de-Albuquerque, Cassiano; Ribeiro Silva, Adriana; Ignácio da Silva, Camila; Caire Castro-Faria-Neto, Hugo; Burth, Patrícia

2017-04-21

Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Subnitride chemistry: A first-principles study of the NaBa3N, Na5Ba3N, and Na16Ba6N phases

International Nuclear Information System (INIS)

Oliva, Josep M.

2005-01-01

An ab initio study on the electronic structure of the subnitrides NaBa 3 N, Na 5 Ba 3 N, and Na 16 Ba 6 N is performed for the first time. The NaBa 3 N and Na 5 Ba 3 N phases consist of infinite 1 ∞ [NBa 6/2 ] strands composed of face-sharing NBa 6 octahedra surrounded by a 'sea' of sodium atoms. The Na 16 Ba 6 N phase consist of discrete [NBa 6 ] octahedra arranged in a body-cubic fashion, surrounded by a 'sea' of sodium atoms. Our calculations suggest that the title subnitrides are metals. Analysis of the electronic structure shows partial interaction of N(2s) with Ba(5p) electrons in the lower energy region for NaBa 3 N and Na 5 Ba 3 N. However, no dispersion is observed for the N(2s) and Ba(5p) bands in the cubic phase Na 16 Ba 6 N. The metallic band below the Fermi level shows a strong mixing of N(2p), Ba(6s), Ba(5d), Ba(6p), Na(3s) and Na(3p) orbitals. The metallic character in these nitrides stems from delocalized electrons corresponding to hybridized 5d l 6s m 6p n barium orbitals which interact with hybridized 3s n 3p m sodium orbitals. Analysis of the electron density and electronic structure in these nitrides shows two different regions: a metallic matrix corresponding to the sodium atoms and the regions around them and heteropolar bonding between nitrogen and barium within the infinite 1 ∞ [NBa 6/2 ] strands of the NaBa 3 N and Na 5 Ba 3 N phases, and within the isolated [NBa 6 ] octahedra of the Na 16 Ba 6 N phase. The nitrogen atoms inside the strands and octahedra are negatively charged, the anionic character of nitrogens being larger in the isolated octahedra of the cubic phase Na 16 Ba 6 N, due to the lack of electron delocalization along one direction as opposed to the other phases. The sodium and barium atoms appear to be slightly negatively and positively charged, the latter to a larger extent. From the computed Ba-N overlap populations as well as the analysis of the contour maps of differences between total density and superposition of

WPŁYW WIEKU NA WYTRZYMAŁOŚĆ NA ŚCISKANIE BETONU MODYFIKOWANEGO DODATKIEM METAKAOLINITU

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Janusz KONKOL

Full Text Available W artykule przedstawiono wyniki badań wytrzymałości na ściskanie betonów modyfikowanych dodatkiem metakaolinitu po 2, 3, 7, 14, 28 i 56 dniach dojrzewania. Dodatek metakaolinitu użyto jako częściowy substytut cementu, dokonując wymiany 10% masy cementu na metakaolinit. Udział ten uznawany jest za optymalny z uwagi na inne niż wytrzymałość na ściskanie właściwości betonu, w tym trwałość betonu modyfikowanego metakaolinitem. Badania przeprowadzono także dla betonu tła, betonu bez dodatku metakaolinitu. Betony wykonano przy założeniu stałego stosunku woda/spoiwo, względnie woda/cement wynoszącego 0,45 oraz przy użyciu cementu portlandzkiego CEM I 32,5R, piasku kwarcowego frakcji do 2 mm oraz grysu bazaltowego frakcji do 16 mm. W celu uzyskania pożądanej konsystencji mieszanki betonowej zastosowano upłynniacz na bazie estrów polikarboksylowych. Uzyskane rezultaty badań potwierdziły wysoką aktywność pucolanową metakaolinitu już we wczesnym okresie dojrzewania betonu. W okresie między 3 a 7 dniem dojrzewania stwierdzono wolniejszy przyrost wytrzymałości na ściskanie w betonie niemodyfikowanym metakaolinitem, podczas gdy w betonie, w którym 10% masy cementu zastąpiono metakaolinitem uwidocznił się znaczący przyrost wytrzymałości na ściskanie. Po 2 dniach dojrzewania wytrzymałość na ściskanie betonu tła była nieznacznie wyższa od wytrzymałości na ściskanie betonu modyfikowanego. Korzystny wpływ dodatku metakaolinitu wynikający z jego wysokiej aktywności pucolanowej, jak również z uszczelniającego charakteru tego dodatku obserwowano jest zwłaszcza w okresie między 3 a 14 dniem dojrzewania. W tym okresie obserwowano znaczny przyrost wytrzymałości na ściskanie betonu modyfikowanego w porównaniu z wytrzymałością na ściskanie betonu tła. Po 7 i 14 dniach dojrzewania stwierdzono odpowiednio prawie 25% i 21% wzrost wytrzymałości na ściskanie na skutek użycia metakaolinitu.

Teratological studies of DTPA-CaNa3, DTPA-ZnNa3 and quinamic acid in mice

International Nuclear Information System (INIS)

Luo Meichu; Ruan Tianming; Tong Shungao

1989-01-01

DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid are effective chelating agents for removing actinide elements from the body. In this experiment, different doses of DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid were given to mice on gestation days 6-10. Eight groups of mice received 0.8 and 2.0 mM/kg of DTPA-CaNa 3 , 3.8, 7.6, and 11.4 mM/kg of DTPA-ZnNa 3 and 0.42, 2.1, and 4.2 mM/kg of quinamic acid. Hypetonic saline and isotonic saline were given to two control groups. DTPA-CaNa 3 and quinamidic acid were found to be much more toxic to fetus of mice than DTPA-ZnNa 3 . When the doses of DTPA-CaMa 3 and quinamidic acid were 20 times higher than the human dose, the number of resorbed fetus was increased and the number and weight of live fetus were reduced. The result of injection with 7.6 mM/kg (200 times of human dose)DTPA-ZnNa 3 and that of injection with isotonic saline are the same. Therefore, we suggest that the DTPA-CaNa 3 and quinamidic acid should not be given to pregnant woman, if chelation therapy is needed, while the much safer DTPA-ZnNa 3 could be used

Na-ion dynamics in Quasi-1D compound NaV2O4

International Nuclear Information System (INIS)

Månsson, M; Umegaki, I; Nozaki, H; Higuchi, Y; Sugiyama, J; Kawasaki, I; Watanabe, I; Sakurai, H

2014-01-01

We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV 2 O 4 . By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above T diff ≈ 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above T diff . Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV 2 O 4 and related compounds in energy related applications

O Passeio Público do Rio de Janeiro na Literatura, na Pintura e na Fotografia do Século XIX

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Solange de Aragão

2012-06-01

Full Text Available Este artigo tem como objetivo geral e mais amplo chamar a atenção dos pesquisadores para a importância da literatura, da pintura e da fotografia como fontes documentais para a construção da História do Paisagismo no Brasil por meio de um estudo de caso muito particular: o Passeio Público do Rio de Janeiro no século XIX. São objetivos específicos apresentar e analisar o modo como esse espaço livre público aparece na literatura, na pintura e na fotografia desse período, considerando suas transformações paisagísticas.

Solubility of NaNd(CO3)2.6H2O(c) in concentrated Na2CO3 and NaHCO3 solutions

International Nuclear Information System (INIS)

Rao, L.; Rai, D.; Felmy, A.R.; Fulton, R.W.; Novak, C.F.

1996-01-01

NaNd(CO 3 ) 2 x 6 H 2 O(c) was identified to be the final equilibrium solid phase in suspensions containing concentrated sodium carbonate (0.1 to 2.0 M) and sodium bicarbonate (0.1 to 1.0 M), with either NaNd(CO 3 ) 2 x 6 H 2 O(c) or Nd 2 (CO 3 ) 3 x xH 2 O(s) as initial solids. A thermodynamic model, based on Pitzer's specific into-interaction approach, was developed to interpret the solubility of NaNd(CO 3 ) 2 x 6 H 2 O(c) as functions of sodium carbonate and sodium bicarbonate concentrations. In this model, the solubility data of NaNd(CO 3 ) 2 x 6 H 2 O(c) were explained by assuming the formation of NdCO 3 + , Nd(CO 3 ) 2 - and Nd(CO 3 ) 3 3- species and invoking the specific ion interactions between Na + and Nd(CO 3 ) 3 3- . Ion interaction parameters for Na + -Nd(CO 3 ) 3 3- were developed to fit the solubility data. Based on the model calculations, Nd(CO 3 ) 3 3- was the predominant aqueous neodymium species in 0.1 to 2 M sodium carbonate and 0.1 to 1 M sodium bicarbonate solutions. The logarithm of the NaNd(CO 3 ) 2 x 6 H 2 O solubility product (NaNd(CO 3 ) 2 x 6 H 2 O(c)=Na + +Nd 3+ +2 CO 3 2- +6 H 2 O) was calculated to be -21.39. This model also provided satisfactory interpretation of the solubility data of the analogous Am(III) system in less concentrated carbonate and bicarbonate solutions. (orig.)

2700-IJBCS-Article-Dr Matar Seck

African Journals Online (AJOL)

hp

of Maytenus senegalensis in the management of sickle cell disease. © 2016 International ... En plus de l'anémie, la vaso-occlusion, résultant de la ... crises de douleur, de la fièvre et des douleurs ... vaso-occlusives dans la drépanocytose. Ces.

Mechanism of μ-conotoxin PIIIA binding to the voltage-gated Na+ channel NaV1.4.

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Rong Chen

Full Text Available Several subtypes of voltage-gated Na+ (NaV channels are important targets for pain management. μ-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of μ-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of μ-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of μ-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to μ-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude.

Muscle K+, Na+, and Cl- disturbances and Na+-K+ pump inactivation: implications for fatigue

DEFF Research Database (Denmark)

McKenna, Michael J; Bangsbo, Jens; Renaud, Jean-Marc

2008-01-01

(+)-ATPase activity during exercise stabilizes Na(+) and K(+) concentration gradients and membrane excitability and thus protects against fatigue. However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue.......Membrane excitability is a critical regulatory step in skeletal muscle contraction and is modulated by local ionic concentrations, conductances, ion transporter activities, temperature, and humoral factors. Intense fatiguing contractions induce cellular K(+) efflux and Na(+) and Cl(-) influx......, causing pronounced perturbations in extracellular (interstitial) and intracellular K(+) and Na(+) concentrations. Muscle interstitial K(+) concentration may increase 1- to 2-fold to 11-13 mM and intracellular K(+) concentration fall by 1.3- to 1.7-fold; interstitial Na(+) concentration may decline by 10 m...

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps

Science.gov (United States)

Vedovato, Natascia

2014-01-01

A single Na+/K+-ATPase pumps three Na+ outwards and two K+ inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na+ than K+ generates outward current across the cell membrane. Less well understood is the ability of Na+/K+ pumps to generate an inward current of protons. Originally noted in pumps deprived of external K+ and Na+ ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K+ and Na+ concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na+ release from phosphorylated Na+/K+ pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na+/K+ pumps that enables proton import is not required for completion of the 3 Na+/2 K+ transport cycle. However, the back-step occurs readily during Na+/K+ transport when external K+ ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na+-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na+ and K+ ions that passes through binding site II. The inferred occurrence of Na+/K+ exchange and H+ import during the same conformational cycle of a single molecule identifies the Na+/K+ pump as a hybrid transporter. Whether Na+/K+ pump–mediated proton inflow may have any physiological or pathophysiological significance remains to be clarified. PMID

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2014-04-01

A single Na(+)/K(+)-ATPase pumps three Na(+) outwards and two K(+) inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na(+) than K(+) generates outward current across the cell membrane. Less well understood is the ability of Na(+)/K(+) pumps to generate an inward current of protons. Originally noted in pumps deprived of external K(+) and Na(+) ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K(+) and Na(+) concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na(+) release from phosphorylated Na(+)/K(+) pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na(+)/K(+) pumps that enables proton import is not required for completion of the 3 Na(+)/2 K(+) transport cycle. However, the back-step occurs readily during Na(+)/K(+) transport when external K(+) ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na(+)-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na(+) and K(+) ions that passes through binding site II. The inferred occurrence of Na(+)/K(+) exchange and H(+) import during the same conformational cycle of a single molecule identifies the Na(+)/K(+) pump as a hybrid transporter. Whether Na(+)/K(+) pump-mediated proton inflow may have any physiological or

Medicinal plants in Brazil: Pharmacological studies, drug discovery, challenges and perspectives.

Science.gov (United States)

Dutra, Rafael C; Campos, Maria M; Santos, Adair R S; Calixto, João B

2016-10-01

This review article focuses on pre-clinical and clinical studies with some selected Brazilian medicinal plants in different areas of interest, conducted by research groups in Brazil and abroad. It also highlights the Brazilian market of herbal products and the efforts of Brazilian scientists to develop new phytomedicines. This review is divided into three sections. The section I describes the Brazilian large biodiversity and some attempts of Brazilian scientists to assess the pharmacological profile of most plant extracts or isolated active principles. Of note, Brazilian scientists have made a great effort to study the Brazilian biodiversity, especially among the higher plants. In fact, more than 10,000 papers were published on plants in international scientific journals between 2011 and 2013. This first part also discussed the main efforts to develop new medicines from plants, highlighting the Brazilian phytomedicines market. Despite the large Brazilian biodiversity, notably with the higher plants, which comprise over 45,000 species (20-22% of the total worldwide), and the substantial number of scientific publications on medicinal plants, only one phytomedicine is found in the top 20 market products. Indeed, this market is still only worth about 261 million American dollars. This represents less than 5% of the global Brazilian medicine market. The section II of this review focus on the use of Brazilian plant extract and/or active principles for some selected diseases, namely: central nervous systems disorders, pain, immune response and inflammation, respiratory diseases, gastrointestinal tract and metabolic diseases. Finally, section III discusses in more details some selected Brazilian medicinal plants including: Cordia verbenacea, Euphorbia tirucalli, Mandevilla velutina, Phyllanthus spp., Euterpe oleracea, Vitis labrusca, Hypericum caprifoliatum and Hypericum polyanthemum, Maytenus ilicifolia, Protium kleinii and Protium heptaphylium and Trichilia catigua. Most

Growth mechanism of NaClO 3 and NaBrO 3 crystals from aqueous ...

Indian Academy of Sciences (India)

A study of growth rates of NaClO3 and NaBrO3 has been carried out using a small growth cell by in situ observation. Normal growth rates of {100} faces of NaClO3 and {111} faces of NaBrO3 along ⟨ 110 ⟩ direction are measured under relatively high supersaturation ranging from 3–8%. In the initial stages of growth, {100}, ...

Rescue of Na+ affinity in aspartate 928 mutants of Na+,K+-ATPase by secondary mutation of glutamate 314.

Science.gov (United States)

Holm, Rikke; Einholm, Anja P; Andersen, Jens P; Vilsen, Bente

2015-04-10

The Na(+),K(+)-ATPase binds Na(+) at three transport sites denoted I, II, and III, of which site III is Na(+)-specific and suggested to be the first occupied in the cooperative binding process activating phosphorylation from ATP. Here we demonstrate that the asparagine substitution of the aspartate associated with site III found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood causes a dramatic reduction of Na(+) affinity in the α1-, α2-, and α3-isoforms of Na(+),K(+)-ATPase, whereas other substitutions of this aspartate are much less disruptive. This is likely due to interference by the amide function of the asparagine side chain with Na(+)-coordinating residues in site III. Remarkably, the Na(+) affinity of site III aspartate to asparagine and alanine mutants is rescued by second-site mutation of a glutamate in the extracellular part of the fourth transmembrane helix, distant to site III. This gain-of-function mutation works without recovery of the lost cooperativity and selectivity of Na(+) binding and does not affect the E1-E2 conformational equilibrium or the maximum phosphorylation rate. Hence, the rescue of Na(+) affinity is likely intrinsic to the Na(+) binding pocket, and the underlying mechanism could be a tightening of Na(+) binding at Na(+) site II, possibly via movement of transmembrane helix four. The second-site mutation also improves Na(+),K(+) pump function in intact cells. Rescue of Na(+) affinity and Na(+) and K(+) transport by second-site mutation is unique in the history of Na(+),K(+)-ATPase and points to new possibilities for treatment of neurological patients carrying Na(+),K(+)-ATPase mutations. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

The system NaVO3-Na2WO4-Na2W2O7

International Nuclear Information System (INIS)

Kazanbekov, V.R.; Gasanaliev, A.M.; Kazanbekov, R.G.

1994-01-01

Phase diagrams of sodium metavanadate-sodium ditungstate, sodium metavanadate-sodium tungstate systems and surface of primary crystallization of sodium metavabadate-sodium tungstate-sodium ditungstate system were studied. The system sodium metavanadate-sodium ditungstate is eutectic one. Compound NaVO 3 x2Na 2 WO 4 is formed in solid state in sodium metavanadate-sodium tungstate system. Liquidus surface of sodium metavanadate-sodium tungstate-sodium ditungstate is presented by three crystallization fields of initial components. Composition and melting point of ternary eutectics are determined

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

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D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF.

We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

Directory of Open Access Journals (Sweden)

D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF. We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

Corte foliar e tempo de transplantio para o uso de plântulas do sub-bosque na restauração florestal

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Ricardo Augusto Gorne Viani

2012-04-01

Full Text Available O uso de plântulas da regeneração natural tem sido recomendado como estratégia para produção de mudas visando à restauração florestal, contudo muitos aspectos técnicos desse método ainda carecem de investigação científica. O objetivo deste trabalho foi avaliar o efeito da redução da área foliar e do transplantio imediato na sobrevivência e crescimento de mudas de espécies arbóreas produzidas a partir de plântulas obtidas da regeneração natural. Plântulas de Esenbeckia leiocarpa (Rutaceae, Eugenia ligustrina (Myrtaceae e Maytenus salicifolia (Celastraceae, obtidas em remanescente de vegetação secundária de Floresta Estacional Semidecidual em Bofete, SP, foram extraídas do solo e submetidas aos tratamentos: I redução de 50% da área de cada folha e transplantio imediato; II nenhuma redução de área das folhas e transplantio imediato; III redução de 50% da área de cada folha, manutenção das plântulas em água e transplantio 24 h após a coleta; e IV nenhuma redução de área das folhas, manutenção das plântulas em água e transplantio 24 h após a coleta. As mudas foram avaliadas com relação à sobrevivência e ao crescimento em altura, ao longo de oito meses. Os resultados evidenciaram que nem o corte das folhas ou a manutenção das plântulas dentro de recipientes com água por 24 h antes do transplantio afetaram os parâmetros avaliados. Assim, para as espécies estudadas a redução da área foliar e o transplantio imediato são desnecessários para a produção de mudas em viveiro a partir de plântulas obtidas da regeneração natural.

Muziki wa Hip Hop na Haki Za Kijamii: Dhima, Changamoto na ...

African Journals Online (AJOL)

Ni dhahiri kuwa haki za kijamii zinaweza kuwasilishwa kwa jamii pana kupitia sanaa ya hip hop. Makala haya basi, yanabainisha dhima na mchango wa muziki wa hip hop katika masuala ya haki za kijamii, yanafafanua changamoto za muziki huu katika kuwasilisha haki za kijamii na kutoa mapendekezo kwa makundi ...

Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

Energy Technology Data Exchange (ETDEWEB)

Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

2015-12-01

Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

Intracellular Na+ regulation of Na+ pump sites in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Allen, J.C.; Navran, S.S.; Seidel, C.L.; Dennison, D.K.; Amann, J.M.; Jemelka, S.K.

1989-01-01

Enzymatically dispersed cells from canine saphenous vein and femoral artery were grown in fetal calf serum and studied at day 0 (freshly dispersed) through confluence in primary culture. Intracellular Na levels (Nai), but not intracellular K (Ki), were increased after 24 h in culture and then decreased to a steady state by 4 days. Na+ pump site number [( 3 H] ouabain binding) increased through day 3 and remained elevated. Nai was still elevated at 2 days when the Na+ pump site number began to increase. Total pump turnover (maximum ouabain-inhibited 86 Rb uptake) reflected the increase in Na+ pump site number. These key events precede the observed increases in both protein production and cellular proliferation. If the same cells are maintained in defined medium, without fetal calf serum, Nai, Ki, and the number of [ 3 H]ouabain binding sites do not change with time. These data are consistent with the suggestion that the initial mitogenic response of vascular smooth muscle cells to fetal calf serum involves an increased Na+ influx, and a Nai accumulation, caused by low Na+ pump density. The synthesis of new pump sites effects a decrease in the accumulated Nai, which may be related to cell proliferation

On the Stability of NaO2 in Na-O2 Batteries.

Science.gov (United States)

Liu, Chenjuan; Carboni, Marco; Brant, William R; Pan, Ruijun; Hedman, Jonas; Zhu, Jiefang; Gustafsson, Torbjörn; Younesi, Reza

2018-04-25

Na-O 2 batteries are regarded as promising candidates for energy storage. They have higher energy efficiency, rate capability, and chemical reversibility than Li-O 2 batteries; in addition, sodium is cheaper and more abundant compared to lithium. However, inconsistent observations and instability of discharge products have inhibited the understanding of the working mechanism of this technology. In this work, we have investigated a number of factors that influence the stability of the discharge products. By means of in operando powder X-ray diffraction study, the influence of oxygen, sodium anode, salt, solvent, and carbon cathode were investigated. The Na metal anode and an ether-based solvent are the main factors that lead to the instability and decomposition of NaO 2 in the cell environment. This fundamental insight brings new information on the working mechanism of Na-O 2 batteries.

NaK handling and removal

International Nuclear Information System (INIS)

Desreumaux, J.; Rodriguez, G.; Guigon, A.; Verdelli, J.; Thomine, G.

1997-01-01

Sodium-potassium alloy is used in specific application in French Fast Breeder Reactors as: cold traps, NaK bubbler for argon purification, valves and also in experimental irradiation devices. lt has been preferred to sodium because it is liquid from + 7 deg. C for the most common peritectic alloy. After its use, NaK is considered as a hazardous waste (nuclear or not) due to its high reactivity with air and water. The most important risk remains in handling NaK systems which have not been operated for some time. The NaK will be covered with a crust of the superoxide K02 which is a strong oxidising agent. Thermodynamically, K02 will react with most organic material or metallic dust or swarfs and can also react with additional NaK to give sufficient heat to boil part of the NaK, resulting in a sudden increase in pressure and small explosions. We describe the formation given to experimenters in our Sodium School and the CEA's experience in treating specific devices for transportation, decanting of tanks, tank opening and NaK removal. (author)

Angiotensin II-induced hypertension increases plasma membrane Na pump activity by enhancing Na entry in rat thick ascending limbs.

Science.gov (United States)

Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

2013-11-01

Thick ascending limbs (TAL) reabsorb 30% of the filtered NaCl load. Na enters the cells via apical Na-K-2Cl cotransporters and Na/H exchangers and exits via basolateral Na pumps. Chronic angiotensin II (ANG II) infusion increases net TAL Na transport and Na apical entry; however, little is known about its effects on the basolateral Na pump. We hypothesized that in rat TALs Na pump activity is enhanced by ANG II-infusion, a model of ANG II-induced hypertension. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 7 days, and TAL suspensions were obtained. We studied plasma membrane Na pump activity by measuring changes in 1) intracellular Na (Nai) induced by ouabain; and 2) ouabain-sensitive oxygen consumption (QO2). We found that the ouabain-sensitive rise in Nai in TALs from ANG II-infused rats was 12.8 ± 0.4 arbitrary fluorescent units (AFU)·mg(-1)·min(-1) compared with only 9.9 ± 1.1 AFU·mg(-1)·min(-1) in controls (P Na pump expression, the number of Na pumps in the plasma membrane, or the affinity for Na. When furosemide (1.1 mg·kg(-1)·day(-1)) was coinfused with ANG II, no increase in plasma membrane Na pump activity was observed. We concluded that in ANG II-induced hypertension Na pump activity is increased in the plasma membrane of TALs and that this increase is caused by the chronically enhanced Na entry occurring in this model.

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie

2016-08-19

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954mAh/g for freestanding silicene and 730mAh/g for the graphenesilicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of >0.3 V against the Na/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be <0.3 eV.

NOVAS APLICAÇÕES DE SISTEMAS SFE "HOME MADE".: I. PLANTAS MEDICINAIS BRASILEIRAS

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Fernando M. LANÇAS

1997-12-01

Full Text Available Neste trabalho, apresenta-se uma visão geral da evolução do uso da SFE (extração com fluido supercrítico na análise de plantas medicinais brasileiras dentro das pesquisas desenvolvidas pelo Laboratório de Cromatografia do IQSC-USP. Utilizou-se como fluido extrator o CO2, puro ou modificado com solventes de polaridade baixa a alta (pentano, solventes halogenados, álcoois, água, para a extração seletiva de princípios ativos de Maytenus aquifolium ("espinheira santa" e Mikania glomerata ("guaco", respectivamente contendo triterpenos e cumarina. Os extratos obtidos por SFE foram analisados por CGAR (cromatografia gasosa de alta resolução, CLAE-DAD (cromatografia líquida de alta eficiência com detector" photodiodearray" ou CCD (cromatografia de camada delgada. A SFE forneceu resultados similares ou melhores do que os obtidos com métodos convencionais de extração (Soxhlet, maceração, etc, indicando o potencial uso da SFE para análise e/ou produção de preparações contendo estas plantas medicinais.Further applications of "home made" SFE systems. I. Brazilian medicinal plants. In this paper, an overview on the evolution of the utilization of SFE for the analysis of Brazilian medicinal plants in the research developed by the Laboratório de Cromatografia, IQSC-USP, is presented. CO2, pure or with modifiers from low to high polarity (pentane, halogenated solvents, alcohols, water were used for the selective extraction of active compounds. Maytenus aquifolium (known popularly in Brazil as" espinheira santa", and Mikania glomerata ("guaco", containing respectively triterpenes and coumarin, were studied. The extracts obtained by SFE showed similar or better results than of those extracts obtained by conventional extraction methods (Soxhlet, maceration, etc., which indicates the potential of SFE technique in the analysis and/or production of phytomedicines.

Hydrolysis of Rice Straw Pretreated by Na2SO3 Over Fe-resin/NaCl

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YANG Hui

2017-05-01

Full Text Available To increase the conversion of rice straw(RS and the yield of products, we employed three methods, which were ultrasonic wave, steam explosion and Na2SO3 pretreatment to pretreat RS(the treated RS noted as CS-RS, ZQ-RS and Na2SO3-RS, respectively and found that Na2SO3 treatment was the best pretreatment method based on XRD, SEM, elemental analysis and content of cellulose, hemicellulose and lignin. The conversion of Na2SO3-RS and the yield of total reducing sugar(TRS and levulinic acid(LA were 97.3%, 29.6% and 13.5%, respectively by 10% Fe-resin in 3.3% NaCl solution under 200 ℃.

Na+/H+ and Na+/NH4+ exchange activities of zebrafish NHE3b expressed in Xenopus oocytes

Science.gov (United States)

Ito, Yusuke; Kato, Akira; Hirata, Taku; Hirose, Shigehisa

2014-01-01

Zebrafish Na+/H+ exchanger 3b (zNHE3b) is highly expressed in the apical membrane of ionocytes where Na+ is absorbed from ion-poor fresh water against a concentration gradient. Much in vivo data indicated that zNHE3b is involved in Na+ absorption but not leakage. However, zNHE3b-mediated Na+ absorption has not been thermodynamically explained, and zNHE3b activity has not been measured. To address this issue, we overexpressed zNHE3b in Xenopus oocytes and characterized its activity by electrophysiology. Exposure of zNHE3b oocytes to Na+-free media resulted in significant decrease in intracellular pH (pHi) and intracellular Na+ activity (aNai). aNai increased significantly when the cytoplasm was acidified by media containing CO2-HCO3− or butyrate. Activity of zNHE3b was inhibited by amiloride or 5-ethylisopropyl amiloride (EIPA). Although the activity was accompanied by a large hyperpolarization of ∼50 mV, voltage-clamp experiments showed that Na+/H+ exchange activity of zNHE3b is electroneutral. Exposure of zNHE3b oocytes to medium containing NH3/NH4+ resulted in significant decreases in pHi and aNai and significant increase in intracellular NH4+ activity, indicating that zNHE3b mediates the Na+/NH4+ exchange. In low-Na+ (0.5 mM) media, zNHE3b oocytes maintained aNai of 1.3 mM, and Na+-influx was observed when pHi was decreased by media containing CO2-HCO3− or butyrate. These results provide thermodynamic evidence that zNHE3b mediates Na+ absorption from ion-poor fresh water by its Na+/H+ and Na+/NH4+ exchange activities. PMID:24401990

The relation between aging, aortic NaF avidity and coronary artery NaF avidity: A NaF PET CT study

DEFF Research Database (Denmark)

Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene

2013-01-01

volunteers without traditional cardiovascular risk factors were prospectively assessed by Sodium 18-Fluoride (Na-18F) PET CT imaging. Global aortic uptake of Na-18F was determined by calculating the average aortic blood pool subtracted maximum standardized uptake value (cSUV) [maximum SUVaorta - mean...

Rescue of Na+ and H+ binding in Na+,K+-ATPase M8 aspartate mutants by secondary mutation

DEFF Research Database (Denmark)

Holm, Rikke; Einholm, Anja P.; Andersen, Jens Peter

A mutation replacing the aspartate in transmembrane segment M8 in the a3-isoform of Na,K-ATPase with asparagine has been found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood. This aspartate may be a critical Na+ coordinating residue, but the crystal......-isoforms of Na,K-ATPase, and much smaller effects were seen for other mutations to the M8 aspartate, which were less disruptive of Na+ binding than mutations to other residues related to Na+ site III. The D928 (rat a1 numbering) mutations strongly diminished the cooperativity of Na+ binding. Moreover the p......H optimum of Na,K-ATPase activity was left-shifted, again with D928N being most disruptive. The reduced affinity for activating Na+ and for inhibitory protons, caused by D928N and D928A mutations, could be rescued by introduction of an additional mutation of a glutamate located far away from D928....

Salinity tolerance in barley (hordeum vulgare l.): effects of varying NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ levels on cultivars differing in tolerance

International Nuclear Information System (INIS)

Mahmood, K.

2011-01-01

Although barley (Hordeum vulgare L.) is regarded as salt tolerant among crop plants, its growth and plant development is severely affected by ionic and osmotic stresses in salt-affected soils. To elucidate the tolerance mechanism, growth and ion uptake of three barley cultivars, differing in salt tolerance, were examined under different levels of NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ in the root medium. The cultivars differed greatly in their responses to varying root medium conditions. Plant growth was more adversely affected by NaHCO/sub 3/ than NaCl. In general, biomass yields were comparable under control and 100 mM NaCl. However, growth of all three cultivars was significantly inhibited by NaHCO/sub 3/ even at low concentration (10 mM). Improved K/sup +/ supply in saline medium increased K/sup +/ uptake and growth of less tolerant cultivars. K/sup +/ uptake was more adversely affected by NaHCO/sub 3/ than NaCl salinity. Selective K/sup +/ uptake and lower Cl/sup -/ in shoots seemed to be associated with the growth responses. K application would help better growth of these cultivars on K-deficient saline-sodic soils and under irrigation with poor quality water having high Residual Sodium Carbonate (RSC) and/or Sodium Adsorption Ratio (SAR). (author)

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

OpenAIRE

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald?J.; Rasmussen, Helge?H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no know...

Myocardial Na,K-ATPase: Clinical aspects

OpenAIRE

Kjeldsen, Keld

2003-01-01

The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs...

Down-Regulation of the Na+-Coupled Phosphate Transporter NaPi-IIa by AMP-Activated Protein Kinase

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Miribane Dërmaku-Sopjani

2013-11-01

Full Text Available Background/Aims: The Na+-coupled phosphate transporter NaPi-IIa is the main carrier accomplishing renal tubular phosphate reabsorption. It is driven by the electrochemical Na+ gradient across the apical cell membrane, which is maintained by Na+ extrusion across the basolateral cell membrane through the Na+/K+ ATPase. The operation of NaPi-IIa thus requires energy in order to avoid cellular Na+ accumulation and K+ loss with eventual decrease of cell membrane potential, Cl- entry and cell swelling. Upon energy depletion, early inhibition of Na+-coupled transport processes may delay cell swelling and thus foster cell survival. Energy depletion is sensed by the AMP-activated protein kinase (AMPK, a serine/threonine kinase stimulating several cellular mechanisms increasing energy production and limiting energy utilization. The present study explored whether AMPK influences the activity of NAPi-IIa. Methods: cRNA encoding NAPi-IIa was injected into Xenopus oocytes with or without additional expression of wild-type AMPK (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1-HA, of inactive AMPKαK45R (AMPKα1K45R+AMPKβ1-Flag+AMPKγ1-HA or of constitutively active AMPKγR70Q (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1R70Q. NaPi-IIa activity was estimated from phosphate-induced current in dual electrode voltage clamp experiments. Results: In NaPi-IIa-expressing, but not in water-injected Xenopus oocytes, the addition of phosphate (1 mM to the extracellular bath solution generated a current (Ip, which was significantly decreased by coexpression of wild-type AMPK and of AMPKγR70Q but not of AMPKαK45R. The phosphate-induced current in NaPi-IIa- and AMPK-expressing Xenopus ooocytes was significantly increased by AMPK inhibitor Compound C (20 µM. Kinetic analysis revealed that AMPK significantly decreased the maximal transport rate. Conclusion: The AMP-activated protein kinase AMPK is a powerful regulator of NaPi-IIa and thus of renal tubular phosphate transport.

Thermodynamic study of NaFe complex oxides. High temperature properties of Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3

CERN Document Server

Furukawa, T

2002-01-01

In order to contribute the investigation into corrosion mechanism of the structural materials by leakage sodium, thermodynamic study of Na-Fe complex oxides formed by the reactions was carried out. Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3 were used as the sample. Its high temperature properties (i.e. melting, solidification and transformation) were observed by Differential Scanning Calorimetry, DSC. Moreover, the original test named 'melting point confirmation test' was performed for the observation of traces of melting and solidification after the tests. Following contents have been obtained by this study. (1) Na sub 5 FeO sub 4 was stably as the solid without phase transformation and melting until 800degC. However, the compound was showing a tendency to change into Na sub 4 FeO sub 3 with temperature increasing under the low oxygen potential. (2) The stability of Na sub 3 FeO sub 3 is the same as that of Na sub 5 FeO sub 4 until 700degC. Over the temperature, the compound was changed differential compound ...

Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon

Energy Technology Data Exchange (ETDEWEB)

Owaki, Shigehiro [Osaka Prefecture Univ., Sakai, Osaka (Japan). Coll. of Integrated Arts and Sciences; Koyama, Shigeko; Takahashi, Masao; Kamada, Masao; Suzuki, Ryouichi

1997-03-01

Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)

Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold

Energy Technology Data Exchange (ETDEWEB)

Xu, Jingke; Shields, Emily; Calaprice, Frank; Westerdale, Shawn; Froborg, Francis; Suerfu, Burkhant; Alexander, Thomas; Aprahamian, Ani; Back, Henning O.; Casarella, Clark; Fang, Xiao; Gupta, Yogesh K.; Ianni, Aldo; Lamere, Edward; Lippincott, W. Hugh; Liu, Qian; Lyons, Stephanie; Siegl, Kevin; Smith, Mallory; Tan, Wanpeng; Kolk, Bryant Vande

2015-07-01

The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3 to 52 keVnr, covering the whole DAMA/LIBRA energy region for dark matter-Na scattering interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies but fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal.

Synthesis of Ag or Pt Nanoparticles by Hydrolysis of Either Ag2Na or PtNa

Directory of Open Access Journals (Sweden)

Huabin Wang

2008-01-01

Full Text Available Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of either Ag2Na or PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst for H2O formation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.

Dynamic polarizabilities and Van der Waals coefficients for alkali atoms Li, Na and alkali dimer molecules Li2, Na2 and NaLi

Science.gov (United States)

Mérawa, M.; Dargelos, A.

1998-07-01

The present paper gives an account of investigations of the polarizability of the alkali atoms Li, Na, diatomics homonuclear and heteronuclear Li2, Na2 and NaLi at SCF (Self Consistent Field) level of approximation and at correlated level, using a time Time-Dependent Gauge Invariant method (TDGI). Our static polarizability values agree with the best experimental and theoretical determinations. The Van der Waals C6 coefficients for the atom-atom, atom-dimer and dimer-dimer interactions have been evaluated. Les polarisabilités des atomes alcalins Li, Na, et des molécules diatomiques homonucléaires et hétéronucléaire Li2, Na2 et NaLi, ont été calculées au niveau SCF (Self Consistent Field) et au niveau corrélé à partir d'une méthode invariante de jauge dépendante du temps(TDGI). Nos valeurs des polarisabilités statiques sont en accord avec les meilleurs déterminations expérimentales et théoriques. Les coefficients C6 de Van de Waals pour les interactions atome-atome, atome-dimère et dimère-dimère ont également été évalués.

Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

DEFF Research Database (Denmark)

Jorgensen, Peter L.; Pedersen, Per Amstrup

2000-01-01

Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

At NA2

CERN Multimedia

1977-01-01

One of the NA2 calorimeter sections is moved in. The NA2 calorimeter was divided in two halves, to the left and the right of the beam, each half consisting of sheets of passive high Z material interleaved with blades of plastic scintillators. The photo shows on the right, the upstream 'electron' module with eleven lead plates for a total radiation length of 20.

Na+-K+ pump in chronic renal failure

International Nuclear Information System (INIS)

Deepak, K.; Kahn, T.

1987-01-01

This review summarizes the evidence for the defect in Na + -K + pump in chronic renal failure, considers the role of various factors in causing this defect, and discusses the clinical implications thereof. Intracellular Na is elevated in erythrocytes, leukocytes, and muscle cells from some patients with chronic renal failure (CRF). Recent evidence suggest that this elevation of cell Na may be, in large part, a consequence of decreased number of Na + -K + pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na + , and this improvement is contemporaneous with an increase in the number of Na + -K + pump sites per cell. In erythrocytes with normal cell Na + , acute hemodialysis increases the rate of 22 Na + and 42 K + transport. Many factors such as the presence of retained toxic metabolite or circulating inhibitor in the uremic plasma, or biochemical changes produced by acute hemodialysis, may explain this finding. In cells with high cell Na + , the pump-mediated 42 K + transport is normalized at the expense of a raised cell Na + . The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na + -K + pump. The authors discuss the role of hormonal abnormalities and circulating inhibitors, which may cause an acute inhibition of the pump and of other factors such as K + depletion, which may cause more chronic alterations. The implications of alteration of Na + and K + pump transport and raised cell Na + on other non-pump-mediated transport pathways are discussed. Raised cell Na + may be a marker for the adequacy of maintenance dialysis in patients with end-stage renal failure

Pozitivni in negativni vplivi risank na otroke

OpenAIRE

Povše, Nika

2017-01-01

V tej diplomski nalogi smo raziskovali pozitivne in negativne vplive risank na otroke. Začeli smo z zgodovino televizije, tako svetovno zgodovino kot zgodovino televizije na Slovenskem. Na isti način smo pregledali tudi zgodovino risank. Raziskovali smo otrokov razvoj, predvsem tiste vidike, ki so izpostavljeni vplivom risank, kot so morala, jezik, domišljija in učenje. Sledilo je raziskovanje negativnih in pozitivnih vplivov, ki jih imajo risanke na otroke, kar je tudi naš glavni problem te ...

Vpliv konfucija na sodobno izobraževanje na Kitajskem

Directory of Open Access Journals (Sweden)

Katja Skitek

2009-12-01

Full Text Available Izobraževanje na Kitajskem je bilo vedno trdno povezano s Konfucijem in konfucianizmom, kar pa ni čudno, saj je bil Konfucij prvi, ki je poudarjal moč z nanja in izobraževanja. LR Kitajska je v zadnjih petdesetih letih počasi in postopoma začela uveljavljati določene spremembe v vzgojno-izobraževalni sistem. Kakšne so te spremembe in koliko nanje še vedno vpliva konfucianizem, bo osrednja tema pričujočega članka. Konfucianizem danes na Kitajskem ni preveč popularen, izobraženci pa so se razporedili v dve skupini: eni trdijo, da je njegov vpliv še vedno velik, drugi pa zatrjujejo, da nima več nobenega vpliva na sodobno življenje. Katera stran ima prav? Konfucij je v prvi vrsti poudarjal pomembnost moralnih vrednot vsakega človeka in prav moralne vrednote, za katere se je zavzemal, so še danes trdno zasidrane v kitajski kulturi. Ali je torej sploh mogoče popolnoma izriniti Konfucija iz sodobnega izobraževanja?

Low-spin states of 23Na

International Nuclear Information System (INIS)

Bakkum, E.L.

1987-01-01

A study of 23 Na via the 22 Ne(p,γ) 23 Na and 23 Na(γ,γ) 23 Na reactions is presented. Only a limited number of resonances has been studied, selected on the basis of strong excitation of the lowest levels of which the spin was unknown. As a result the spins are now known of all levels of 23 Na with excitation energies up to 7 MeV, except for a few high-spin states which are too weakly excited in the decay of the known 22 Ne(p,γ) resonances. The mean lifetimes of the 23 Na levels at 4.43 and 7.89 MeV were found to be 350±70 and 220±17 attoseconds (1 attosecond = 10 -18 seconds) respectively. 97 refs.; 22 figs.; 12 tabs

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, Thomas J.; Verstegen, Martin W.A.; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H.

2017-01-01

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Clues to NaCN formation

Science.gov (United States)

Quintana-Lacaci, G.; Cernicharo, J.; Velilla Prieto, L.; Agúndez, M.; Castro-Carrizo, A.; Fonfría, J. P.; Massalkhi, S.; Pardo, J. R.

2017-11-01

Context. ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to understand the formation of many species, and to significantly improve our knowledge of the chemistry that occurs in the space. Aims: We studied the molecular distribution of NaCN around IRC +10216, a molecule detected previously, but whose origin is not clear. High angular resolution maps allow us to model the abundance distribution of this molecule and check suggested formation paths. Methods: We modeled the emission of NaCN assuming local thermal equilibrium (LTE) conditions. These profiles were fitted to azimuthal averaged intensity profiles to obtain an abundance distribution of NaCN. Results: We found that the presence of NaCN seems compatible with the presence of CN, probably as a result of the photodissociation of HCN, in the inner layers of the ejecta of IRC +10216. However, similar as for CH3CN, current photochemical models fail to reproduce this CN reservoir. We also found that the abundance peak of NaCN appears at a radius of 3 × 1015 cm, approximately where the abundance of NaCl, suggested to be the parent species, starts to decay. However, the abundance ratio shows that the NaCl abundance is lower than that obtained for NaCN. We expect that the LTE assumption might result in NaCN abundances higher than the real ones. Updated photochemical models, collisional rates, and reaction rates are essential to determine the possible paths of the NaCN formation. Based on observations carried out with ALMA and the IRAM 30 m Telescope. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. IRAM is supported by INSU/CNRS (France

The effect of Na+ and K+ on the thermal denaturation of Na+ and + K+-dependent ATPase.

Science.gov (United States)

Fischer, T H

1983-01-01

To increase our understanding of the physical nature of the Na+ and K+ forms of the Na+ + K+-dependent ATPase, thermal-denaturation studies were conducted in different types of ionic media. Thermal-denaturation measurements were performed by measuring the regeneration of ATPase activity after slow pulse exposure to elevated temperatures. Two types of experiments were performed. First, the dependence of the thermal-denaturation rate on Na+ and K+ concentrations was examined. It was found that both cations stabilized the pump protein. Also, K+ was a more effective stabilizer of the native state than was Na+. Secondly, a set of thermodynamic parameters was obtained by measuring the temperature-dependence of the thermal-denaturation rate under three ionic conditions: 60 mM-K+, 150 mM-Na+ and no Na+ or K+. It was found that ion-mediated stabilization of the pump protein was accompanied by substantial increases in activation enthalpy and entropy, the net effect being a less-pronounced increase in activation free energy. PMID:6309139

Financiranje projekata na pomorskom dobru

Directory of Open Access Journals (Sweden)

Zoran Tasić

2018-02-01

Full Text Available Koncesije otvaraju vrlo osjetljiva politička, ekonomska i pravna pitanja u mnogim državama svijeta. Samo definiranje pojma koncesije često je komplicirana i ne sasvim jasna zadaća. OECD je prihvatila definiciju koncesije kao: ’’davanje prava privatnom trgovačkom društvu da može gospodarski upravljati određenom infrastrukturnim uslugama i za to zarađivati naknadu. Koncesionar dobija u posjed određene objekte (ali vlasništvo na tim objektima ostaje u rukama države te ih koristi u svrhu obavljanja određene djelatnosti ili usluge sukladno odredbama ugovora’’. Hrvatsko pravo definira koncesije načelno kao pravo stečeno temeljem ugovora o koncesiji, a sukladno uvjetima sadržanim u odluci o davanju koncesije (koju je donijelo odgovarajuće upravno tijelo, a u odnosu na pomorsko dobro, specifično, kao pravo državne vlasti da može dio pomorskog dobra, koje je inače dobro izvan pravnog prometa (res extra commercium, isključiti iz opće uporabe bilo dijelom ili u cijelosti, i dati ga fizičkoj ili pravnoj osobi na gospodarsko korištenje sukladno određenim prostornim planovima. Građevine i drugi objekti izgrađeni na pomorskom dobru čine njegov sastavni dio. Zakonom je jasno određeno da nikakva stvarna prava nisu dopuštena na pomorskom dobru, uključivo i na objektima izgrađenima na njemu. Projekti na pomorskom dobru često uključuju velike infrastrukturne projekte, razvoje luka i marina, koji iziskuju značajna financijska sredstva. Banke koje financiraju takve projekte zahtijevaju organiziran i transparentan zakonski okvir koncesija, slobodu ugovaranja, pravnu zaštitu svih strana uključenih u projekt (uključivo i mogućnost međunarodne arbitraže. (...

Controlled phase stability of highly Na-active triclinic structure in nanoscale high-voltage Na2-2xCo1+xP2O7 cathode for Na-ion batteries

Science.gov (United States)

Song, Hee Jo; Kim, Jae-Chan; Dar, Mushtaq Ahmad; Kim, Dong-Wan

2018-02-01

With the increasing demand for high energy density in energy-storage systems, a high-voltage cathode is essential in rechargeable Li-ion and Na-ion batteries. The operating voltage of a triclinic-polymorph Na2CoP2O7, also known as the rose form, is above 4.0 V (vs. Na/Na+), which is relatively high compared to that of other cathode materials. Thus, it can be employed as a potential high-voltage cathode material in Na-ion batteries. However, it is difficult to synthesize a pure rose phase because of its low phase stability, thus limiting its use in high-voltage applications. Herein, compositional-engineered, rose-phase Na2-2xCo1+xP2O7/C (x = 0, 0.1 and 0.2) nanopowder are prepared using a wet-chemical method. The Na2-2xCo1+xP2O7/C cathode shows high electrochemical reactivity with Na ions at 4.0 V, delivering high capacity and high energy density.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

Directory of Open Access Journals (Sweden)

Rafiza Abdul Razak

2015-05-01

Full Text Available This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA using LUSI (Sidoarjo mud and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

Science.gov (United States)

Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

2015-01-01

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

UTJECAJ POZITIVNE DISKRIMINACIJE NA UKLJUČIVANJE ŽENA NA TRŽIŠTE RADA U REPUBLICI HRVATSKOJ

OpenAIRE

Dovranić, Dora; Katavić, Ivica

2016-01-01

U početku 21. stoljeća često se koristi pojam pozitivne (afirmativne) diskriminacije. Pozitivna diskriminacija mjera je koju poduzima vlada, neka organizacija ili korporacija s ciljem da se smanje nejednakosti u društvu nastale upravo diskriminacijom, na način da se pružaju određene povlastice onima koji su pretrpjeli neku vrstu diskriminacije. Nastala je u Sjedinjenim Američkim Državama na inicijativu predsjednika Kennedyja, Johnsona i Nixona. Diskriminacija, nažalost, ima mnogo oblika, a ne...

Reaction of metal oxides with molten mixtures NaPO3+NaCl

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

By methods of solubility determination and paper chromatography it is shown, that Fe 2 O 3 solution in NaPO 3 +NaCl melts in the air relizes due to its chemical interaction with solvent resulting in formation of iron and sodium binary di- and monophosphates depending on melt-solvent initial composition, its attainment of equilibrium state and experiment temperature. It is established, that oxides increased solubility in melts with NaCl initial content ∼30 mol.% is specified by sodium tri- and tricyclophosphates presence in the melts. On this basis of NGR-spectroscopy data the presence of iron, europium, tin and sodium binary di- and monophosphates in some chloride-polyphosphate melts is confirmed

Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

International Nuclear Information System (INIS)

Murashova, E.V.; Chudinova, N.N.

1997-01-01

Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

Effect of growth in lithium on ouabain binding, Na-K-ATPase and Na and K transport in hela cells.

Science.gov (United States)

Boardman, L J; Hume, S P; Lamb, J F; Polson, J

1975-01-01

1. HeLa cells were grown for 24 hr in growth medium in which part of the Na was replaced with Li. Ion contents, cell volumes and numbers, Na-K-ATPase and specific ouabain binding were measured. In some experiments the Na efflux and net Na transport was also measured. 2. Growth in Li caused a rise in the specific ouabain binding and membrane Na-K-ATPase of these cells. The Li concentrations in the cells necessary to produce this effect ranged up to 50 mM. 3. It is suggested that Li, like Na, acts on the genetic material of the cells to cause the production of more Na pumps within the membrane. PMID:124350

Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

1954-01-01

The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

Novel aspects of Na+,K+-ATPase

OpenAIRE

Aizman, Oleg

2002-01-01

Na,K-ATPase, an integral membrane protein expressed in each eukaryotic cell, serves as the major determinant of intracellular ion composition. In the current study we investigated novel aspects of Na,K-ATPase function and regulation. It is well established that Na,K-ATPase activity is regulated by reversible phosphorylation. New findings in this study are: 1) the level of intracellular Ca 2. concentration determines the functional effects of PKA and PKC-mediated Na,K-ATP...

High-Performance Na-O2 Batteries Enabled by Oriented NaO2 Nanowires as Discharge Products.

Science.gov (United States)

Khajehbashi, S Mohammad B; Xu, Lin; Zhang, Guobin; Tan, Shuangshuang; Zhao, Yan; Wang, Lai-Sen; Li, Jiantao; Luo, Wen; Peng, Dong-Liang; Mai, Liqiang

2018-06-13

Na-O 2 batteries are emerging rechargeable batteries due to their high theoretical energy density and abundant resources, but they suffer from sluggish kinetics due to the formation of large-size discharge products with cubic or irregular particle shapes. Here, we report the unique growth of discharge products of NaO 2 nanowires inside Na-O 2 batteries that significantly boosts the performance of Na-O 2 batteries. For this purpose, a high-spin Co 3 O 4 electrocatalyst was synthesized via the high-temperature oxidation of pure cobalt nanoparticles in an external magnetic field. The discharge products of NaO 2 nanowires are 10-20 nm in diameter and ∼10 μm in length, characteristics that provide facile pathways for electron and ion transfer. With these nanowires, Na-O 2 batteries have surpassed 400 cycles with a fixed capacity of 1000 mA h g -1 , an ultra-low over-potential of ∼60 mV during charging, and near-zero over-potential during discharging. This strategy not only provides a unique way to control the morphology of discharge products to achieve high-performance Na-O 2 batteries but also opens up the opportunity to explore growing nanowires in novel conditions.

Insight to the Thermal Decomposition and Hydrogen Desorption Behaviors of NaNH2-NaBH4 Hydrogen Storage Composite.

Science.gov (United States)

Pei, Ziwei; Bai, Ying; Wang, Yue; Wu, Feng; Wu, Chuan

2017-09-20

The lightweight compound material NaNH 2 -NaBH 4 is regarded as a promising hydrogen storage composite due to the high hydrogen density. Mechanical ball milling was employed to synthesize the composite NaNH 2 -NaBH 4 (2/1 molar ratio), and the samples were investigated utilizing thermogravimetric-differential thermal analysis-mass spectroscopy (TG-DTA-MS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The full-spectrum test (range of the ratio of mass to charge: 0-200) shows that the released gaseous species contain H 2 , NH 3 , B 2 H 6 , and N 2 in the heating process from room temperature to 400 °C, and possibly the impurity gas B 6 H 12 also exists. The TG/DTA analyses show that the composite NaNH 2 -NaBH 4 (2/1 molar ratio) is conductive to generate hydrogen so that the dehydrogenation process can be finished before 400 °C. Moreover, the thermal decomposition process from 200 to 400 °C involves two-step dehydrogenation reactions: (1) Na 3 (NH 2 ) 2 BH 4 hydride decomposes into Na 3 BN 2 and H 2 (200-350 °C); (2) remaining Na 3 (NH 2 ) 2 BH 4 reacts with NaBH 4 and Na 3 BN 2 , generating Na, BN, NH 3 , N 2 , and H 2 (350-400 °C). The better mechanism understanding of the thermal decomposition pathway lays a foundation for tailoring the hydrogen storage performance of the composite complex hydrides system.

Distinct pH dependencies of Na+/K+ selectivity at the two faces of Na,K-ATPase.

Science.gov (United States)

Cornelius, Flemming; Tsunekawa, Naoki; Toyoshima, Chikashi

2018-02-09

The sodium pump (Na,K-ATPase) in animal cells is vital for actively maintaining ATP hydrolysis-powered Na + and K + electrochemical gradients across the cell membrane. These ion gradients drive co- and countertransport and are critical for establishing the membrane potential. It has been an enigma how Na,K-ATPase discriminates between Na + and K + , despite the pumped ion on each side being at a lower concentration than the other ion. Recent crystal structures of analogs of the intermediate conformations E2·Pi·2K + and Na + -bound E1∼P·ADP suggest that the dimensions of the respective binding sites in Na,K-ATPase are crucial in determining its selectivity. Here, we found that the selectivity at each membrane face is pH-dependent and that this dependence is unique for each face. Most notable was a strong increase in the specific affinity for K + at the extracellular face ( i.e. E2 conformation) as the pH is lowered from 7.5 to 5. We also observed a smaller increase in affinity for K + on the cytoplasmic side (E1 conformation), which reduced the selectivity for Na + Theoretical analysis of the p K a values of ion-coordinating acidic amino acid residues suggested that the face-specific pH dependences and Na + /K + selectivities may arise from the protonation or ionization of key residues. The increase in K + selectivity at low pH on the cytoplasmic face, for instance, appeared to be associated with Asp 808 protonation. We conclude that changes in the ionization state of coordinating residues in Na,K-ATPase could contribute to altering face-specific ion selectivity. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

OGLAŠEVANJE NA FACEBOOKU

OpenAIRE

Renko, Katica

2013-01-01

V magistrskem delu smo se seznanili z oglaševanjem na Facebooku. S pregledom gradiva, ki nam je ponujeno, smo preverili pogoje, načine, oblike … oglaševanja, ki pa smo jih s pregledom situacije v praksi preverili in dopolnili. Ob zaključku dela lahko rečemo, da je oglaševanje preko FB enostavnejše, cenejše, dostopnejše, omogoča nam ažurnost in samo komunikacijo z naslovniki, ki so potencialni kupci naših ponudb. Množični mediji nam omogočajo mnogotero obliko oglaševanja. Izbrana oblika ponuja...

Bio-evaluation of South African plants for insecticidal properties

CSIR Research Space (South Africa)

Maharaj, R

2006-02-01

Full Text Available Flacourtia indica Maytenus senegalensis Psiadia punctulata Ximenia caffra Dodonaea viscosa Helichrysum species Nuxia floribunda Pterocarpus angolensis Euphorbia tirucalli Lippia javanica Parinari curatellifolia Rauvolfia caffra Hyptis pectinata Parinari... crispus Schefflera umbellifera Rauvolfia caffra Schefflera umbellifera Strychnos madagascariensis Ricinus communis Spirostachys africana Vangueria infausta Rumex crispus Strychnos potatorum Warburgia salutaris Schefflera umbellifera Vernonia myriantha...

Laser-induced ionization of Na vapor

International Nuclear Information System (INIS)

Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

1982-01-01

The production of Na 2 + ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na 2 molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na 2 D 1 PIμ Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na 2 + ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na 2 + through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na 2 molecules

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

Energy Technology Data Exchange (ETDEWEB)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik, E-mail: niknizam@fbb.utm.my

2016-02-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550 °C, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

International Nuclear Information System (INIS)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

2016-01-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550 °C, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

Carbon dioxide sequestration using NaHSO4 and NaOH: A dissolution and carbonation optimisation study.

Science.gov (United States)

Sanna, Aimaro; Steel, Luc; Maroto-Valer, M Mercedes

2017-03-15

The use of NaHSO 4 to leach out Mg fromlizardite-rich serpentinite (in form of MgSO 4 ) and the carbonation of CO 2 (captured in form of Na 2 CO 3 using NaOH) to form MgCO 3 and Na 2 SO 4 was investigated. Unlike ammonium sulphate, sodium sulphate can be separated via precipitation during the recycling step avoiding energy intensive evaporation process required in NH 4 -based processes. To determine the effectiveness of the NaHSO 4 /NaOH process when applied to lizardite, the optimisation of the dissolution and carbonation steps were performed using a UK lizardite-rich serpentine. Temperature, solid/liquid ratio, particle size, concentration and molar ratio were evaluated. An optimal dissolution efficiency of 69.6% was achieved over 3 h at 100 °C using 1.4 M sodium bisulphate and 50 g/l serpentine with particle size 75-150 μm. An optimal carbonation efficiency of 95.4% was achieved over 30 min at 90 °C and 1:1 magnesium:sodium carbonate molar ratio using non-synthesised solution. The CO 2 sequestration capacity was 223.6 g carbon dioxide/kg serpentine (66.4% in terms of Mg bonded to hydromagnesite), which is comparable with those obtained using ammonium based processes. Therefore, lizardite-rich serpentinites represent a valuable resource for the NaHSO 4 /NaOH based pH swing mineralisation process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite.

Science.gov (United States)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

2016-02-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550°C, 5h) and this material has excellent performance as an antibacterial agent after silver ions loading. Copyright © 2015 Elsevier B.V. All rights reserved.

Composition and thermochemistry of the equilibrium vapour of the systems NaI-FeI2 and NaI-PbI2

International Nuclear Information System (INIS)

Hilpert, K.; Gerads, H.; Koberts, D.; Miller, M.

1987-01-01

The vaporization of NaI/FeI 2 and NaI/PbI 2 samples of equimolar composition was investigated was investigated in the temperature ranges between 574 to 683 K and 562 to 669 K, respectively, by using the mass spectrometric Knudsen effusion method. The gaseous species I, I 2 , NaI, (NaI) 2 , FeI 2 , (FeI 2 ) 2 , FeI 3 , NaFeI 3 , and Na 2 FeI 4 (NaI-FeI 2 system) as well as NaI, (NaI) 2 , PbI 2 , (PbI 2 ) 2 , and NaPbI 3 (NaI-PbI 2 system) are present in the equilibrium vapours. The equilibrium partial pressures of these species were determined with the exception of I, I 2 , and FeI 3 . Enthalpies and entropies of dissociation resulted for the reactions NaFeI 3 (g) ↔ NaI(g)+FeI 2 (g) (1), Na 2 FeI 4 (g) ↔ 2NaI(g)+FeI 2 (g) and (2) NaPbI 3 (g) ↔ NaI(g)+PbI 2 (g) (3) as Δ d H 298 0 (Eq. (1)) = 184±5 kJ mol -1 , Δ d S 298 0 (Eq. (1)) = 143±8 J mol -1 K -1 ; Δ d H 298 0 (Eq. (2)) = 333±9 kJ mol -1 , Δ d S 298 0 (Eq. (2)) = 274±14 J mol -1 K -1 ; and Δ d H 298 0 (Eq. (3)) = 168±5 kJ mol -1 , Δ d S 298 0 (Eq. (3)) = 151±9 J mol -1 K -1 . Equilibrium constants for these reactions are additionally given. The pressures of NaFeI 3 (g) and NaPbI 3 (g) as all as their enthalpies of dissociation are discussed with respect to their significance of semi empirical rules. (orig.)

Phylogeny of the Celastreae (Celastraceae) and the relationships of Catha edulis (qat) inferred from morphological characters and nuclear and plastid genes.

Science.gov (United States)

Simmons, Mark P; Cappa, Jennifer J; Archer, Robert H; Ford, Andrew J; Eichstedt, Dedra; Clevinger, Curtis C

2008-08-01

The phylogeny of Celastraceae tribe Celastreae, which includes about 350 species of trees and shrubs in 15 genera, was inferred in a simultaneous analysis of morphological characters together with nuclear (ITS and 26S rDNA) and plastid (matK, trnL-F) genes. A strong correlation was found between the geography of the species sampled and their inferred relationships. Species of Maytenus and Gymnosporia from different regions were resolved as polyphyletic groups. Maytenus was resolved in three lineages (New World, African, and Austral-Pacific), while Gymnosporia was resolved in two lineages (New World and Old World). Putterlickia was resolved as nested within the Old World Gymnosporia. Catha edulis (qat, khat) was resolved as sister to the clade of Allocassine, Cassine, Lauridia, and Maurocenia. Gymnosporia cassinoides, which is reportedly chewed as a stimulant in the Canary Islands, was resolved as a derived member of Gymnosporia and is more closely related to Lydenburgia and Putterlickia than it is to Catha. Therefore, all eight of these genera are candidates for containing cathinone- and/or cathine-related alkaloids.

Phylogeny of the Celastraceae inferred from 26S nuclear ribosomal DNA, phytochrome B, rbcL, atpB, and morphology.

Science.gov (United States)

Simmons, M P; Savolainen, V; Clevinger, C C; Archer, R H; Davis, J I

2001-06-01

Phylogenetic relationships within Celastraceae (spindle-tree family) were inferred from nucleotide sequence characters from the 5' end of 26S nuclear ribosomal DNA (including expansion segments D1-D3; 84 species sampled), phytochrome B (58 species), rbcL (31 species), atpB (23 species), and morphology (94 species). Among taxa of questionable affinity, Forsellesia is a member of Crossosomataceae, and Goupia is excluded from Celastraceae. However, Brexia, Canotia, Lepuropetalon, Parnassia, Siphonodon, and Stackhousiaceae are supported as members of Celastraceae. Gymnosporia and Tricerma are distinct from Maytenus, Cassine is supported as distinct from Elaeodendron, and Dicarpellum is distinct from Salacia. Catha, Maytenus, and Pristimera are not resolved as natural genera. Hippocrateaceae (including Plagiopteron and Lophopetalum) are a clade nested within a paraphyletic Celastraceae. These data also suggest that the Loesener's classification of Celastraceae sensu stricto and Hallé's classification of Hippocrateaceae are artificial. The diversification of the fruit and aril within Celastraceae appears to be complex, with multiple origins of most fruit and aril forms. Copyright 2001 Academic Press.

Adsorption and Formation of Small Na Clusters on Pristine and Double-Vacancy Graphene for Anodes of Na-Ion Batteries.

Science.gov (United States)

Liang, Zhicong; Fan, Xiaofeng; Zheng, Weitao; Singh, David J

2017-05-24

Layered carbon is a likely anode material for Na-ion batteries (NIBs). Graphitic carbon has a low capacity of approximately 35 (mA h)/g due to the formation of NaC 64 . Using first-principles methods including van der Waals interactions, we analyze the adsorption of Na ions and clusters on graphene in the context of anodes. The interaction between Na ions and graphene is found to be weak. Small Na clusters are not stable on the surface of pristine graphene in the electrochemical environment of NIBs. However, we find that Na ions and clusters can be stored effectively on defected graphene that has double vacancies. In addition, the adsorption energy of small Na clusters near a double vacancy is found to decrease with increasing cluster size. With high concentrations of vacancies the capacity of Na on defective graphene is found to be as much as 10-30 times higher than that of graphitic carbon.

Novel regulation of cardiac Na pump via phospholemman.

Science.gov (United States)

Pavlovic, Davor; Fuller, William; Shattock, Michael J

2013-08-01

As the only quantitatively significant Na efflux pathway from cardiac cells, the Na/K ATPase (Na pump) is the primary regulator of intracellular Na. The transmembrane Na gradient it establishes is essential for normal electrical excitability, numerous coupled-transport processes and, as the driving force for Na/Ca exchange, thus setting cardiac Ca load and contractility. As Na influx varies with electrical excitation, heart rate and pathology, the dynamic regulation of Na efflux is essential. It is now widely recognized that phospholemman, a 72 amino acid accessory protein which forms part of the Na pump complex, is the key nexus linking cellular signaling to pump regulation. Phospholemman is the target of a variety of post-translational modifications (including phosphorylation, palmitoylation and glutathionation) and these can dynamically alter the activity of the Na pump. This review summarizes our current understanding of the multiple regulatory mechanisms that converge on phospholemman and govern NA pump activity in the heart. The corrected Fig. 4 is reproduced below. The publisher would like to apologize for any inconvenience caused. [corrected]. Copyright © 2013. Published by Elsevier Ltd.

All new for NA62

CERN Multimedia

Antonella Del Rosso

2012-01-01

This week sees the start of the first run of the new NA62 experiment. This will be a unique opportunity for the collaboration to test its new beam, new detectors and new data acquisition system before the physics run in 2014. Speaking to the Bulletin, the NA62 technical coordinator Ferdinand Hahn shares the many challenges that the various teams faced to be on time for beam. Ready, steady, start!   A Large Angle Veto detector (white) in place in the NA62 decay volume (blue). With components from almost all the detectors in place downstream of the decay point of the mother particles – the kaons – and of the KTAG detector that tags the kaons before they decay, NA62 is ready for its first technical run. This unique run will test all the equipment as well as the trigger and the data acquisition systems. “This year, we will have about five weeks of beam from the SPS before the long shutdown of all the CERN machines,” says Ferdinand Hahn, NA62 Technical Co-...

Effect of chloride substitution on the order–disorder transition in NaBH4 and Na11BD4

International Nuclear Information System (INIS)

Olsen, Jørn Eirik; Karen, Pavel; Sørby, Magnus H.; Hauback, Bjørn C.

2014-01-01

Graphical abstract: Interactions that order the BD 4 - tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na( 11 BD 4 ) 1−x Cl x solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH 4 ) 1−x Cl x and Na( 11 BD 4 ) 1−x Cl x is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na( 11 BD 4 ) 1−x Cl x for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na 11 BD 4 at room temperature and 8 K and Na( 11 BD 4 ) 1−x Cl x (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na 11 BD 4 (NaBH 4 ) and its solid solutions with NaCl, Na( 11 BD 4 ) 1−x Cl x , is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na 11 BD 4 , ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na( 11 BD 4 ) 1−x Cl x follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na 11 BD 4 ) at 8 K

Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yahia, H. Ben [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Essehli, R., E-mail: ressehli@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Avdeev, M. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights NSW 2234 (Australia); Park, J-B.; Sun, Y-K. [Department of Energy Engineering Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Al-Maadeed, M.A. [Center for Advanced Materials (CAM), Qatar University, 2713 Doha (Qatar); Belharouak, I., E-mail: ibelharouak@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar)

2016-06-15

The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structures of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.

Evaluation of NaX and NaY packed beds for chromium uptake from multicomponent solution

Directory of Open Access Journals (Sweden)

Maria Angélica Simões Dornellas de Barros

2014-04-01

Full Text Available In this paper the removal of chromium from Cr/Ca/Mg/K and Cr/Ca/Mg/K/Na solutions was investigated in NaX and NaY packed beds. The breakthrough curves presented some overshooting phenomena where chromium ions displaced the previous exchanged cations. Length of unused bed, overall mass transfer coefficient, operational ratio and dimensionless variance were obtained. According to such mass transfer parameters it was concluded that the chromium uptake is influenced by the competition and interaction of the entering ions. Such influences were verified through some differences in the dynamic selectivity obtained for each system. NaY seemed to have a higher affinity towards Cr3+ and its sites were more efficiently used in the ion exchange process.

Water transport by the renal Na(+)-dicarboxylate cotransporter

DEFF Research Database (Denmark)

Meinild, A K; Loo, D D; Pajor, A M

2000-01-01

. This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume...

Pioneering instrumentation aspects of NA60

International Nuclear Information System (INIS)

David, Andre

2004-01-01

NA60 is taking data with proton and heavy-ion beams at the CERN SPS. Although building up on previous experiments, the dimuon physics programme of NA60 places very demanding requirements on its new detectors, in terms of radiation tolerance, granularity and read-out electronics speed. We start by comparing dimuon detection strategies in NA60 with those of previous experiments. We then describe the new detectors used in NA60, placing particular emphasis on their technological pioneering aspects as well as on their contributions to the overall physics performance of the experiment

Occlusion of 22Na+ and 86Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

International Nuclear Information System (INIS)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-01-01

In this work, we examined occlusion of 22 Na+ and 86 Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of 22 Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of 22 Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by 32 P incorporation from [gamma- 32 P]CrATP. Maximum capacity for phosphorylation from [gamma- 32 P]CrATP was 6 nmol/mg of protein and equal to capacities for binding of [48V]vanadate and [ 3 H]ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport

Transcriptional regulators of Na, K-ATPase subunits

Directory of Open Access Journals (Sweden)

Zhiqin eLi

2015-10-01

Full Text Available The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during development and to accommodate physiological needs. The spatial and temporal expression of Na,K-ATPase is partially regulated at the transcriptional level. Numerous transcription factors, hormones, growth factors, lipids and extracellular stimuli modulate the transcription of the Na,K-ATPase subunits. Moreover, epigenetic mechanisms also contribute to the regulation of Na,K-ATPase expression. With the ever growing knowledge about diseases associated with the malfunction of Na,K-ATPase, this review aims at summarizing the best-characterized transcription regulators that modulate Na,K-ATPase subunit levels. As abnormal expression of Na,K-ATPase subunits have been observed in many carcinoma, we will also discuss transcription factors that are associated with epithelial-to-mesenchymal transition, a crucial step in the progression of many tumors to malignant disease.

Sepsis does not alter red blood cell glucose metabolism or Na+ concentration: A 2H-, 23Na-NMR study

International Nuclear Information System (INIS)

Hotchkiss, R.S.; Song, S.K.; Ling, C.S.; Ackerman, J.J.; Karl, I.E.

1990-01-01

The effects of sepsis on intracellular Na+ concentration ([Na+]i) and glucose metabolism were examined in rat red blood cells (RBCs) by using 23Na- and 2H-nuclear magnetic resonance (NMR) spectroscopy. Sepsis was induced in 15 halothane-anesthetized female Sprague-Dawley rats by using the cecal ligation and perforation technique; 14 control rats underwent cecal manipulation without ligation. The animals were fasted for 36 h, but allowed free access to water. At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent. Human RBCs from 17 critically ill nonseptic patients and from 7 patients who were diagnosed as septic were also examined for [Na+]i. Five rat RBC specimens had [Na+]i determined by both 23Na-NMR and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). For glucose metabolism studies, RBCs from septic and control rats were suspended in modified Krebs-Henseleit buffer containing [6,6-2H2]glucose and examined by 2H-NMR. No significant differences in [Na+]i or glucose utilization were found in RBCs from control or septic rats. There were no differences in [Na+]i in the two groups of patients. The [Na+]i determined by NMR spectroscopy agreed closely with measurements using ICP-AES and establish that 100% of the [Na+]i of the RBC is visible by NMR. Glucose measurements determined by 2H-NMR correlated closely (correlation coefficient = 0.93) with enzymatic analysis. These studies showed no evidence that sepsis disturbed RBC membrane function or metabolism

SPOLNO NADLEGOVANJE NA DELOVNEM MESTU

OpenAIRE

Rubič, Gašper

2016-01-01

V diplomskem delu smo v uvodu predstavili problem spolnega nadlegovanja na delovnem mestu in predstavili podjetje TEKSTIL d.d. V nadaljevanju smo z anketo raziskali, ali problem spolnega nadlegovanja na delovnem mestu v obravnavanem podjetju obstaja in če, kako se nanj odziva okolje. V teoretičnem delu smo nadaljevali in predstavili definicijo spolnega nadlegovanja, ki je kakršna koli oblika nezaželenega verbalnega in neverbalnega ali fizičnega ravnanja spolne narave z učinkom ali nameno...

Photodesorption of Na atoms from rough Na surfaces

DEFF Research Database (Denmark)

Balzer, Frank; Gerlach, R.; Manson, J.R.

1997-01-01

We investigate the desorption of Na atoms from large Na clusters deposited on dielectric surfaces. High-resolution translational energy distributions of the desorbing atoms are determined by three independent methods, two-photon laser-induced fluorescence, as well as single-photon and resonance......-enhanced two-photon ionization techniques. Upon variation of surface temperature and for different substrates (mica vs lithium fluoride) clear non-Maxwellian time-of-flight distributions are observed with a cos θ angular dependence and most probable kinetic energies below that expected of atoms desorbing from...... atoms are scattered by surface vibrations. Recent experiments providing time constants for the decay of the optical excitations in the clusters support this model. The excellent agreement between experiment and theory indicates the importance of both absorption of the laser photons via direct excitation...

Evaluation of {sup 23}Na(n,2n){sup 22}Na reaction cross-sections

Energy Technology Data Exchange (ETDEWEB)

Manokhin, V N [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1997-06-01

Using available experimental data and (n,2n) excitation function systematics {sup 23}Na(n,2n){sup 22}Na reaction cross-sections were evaluated for energies ranging from the reaction threshold to 20 MeV. (author). 21 refs, 1 fig., 2 tabs.

Formation of hydroxyl groups and exchange with deuterium on NaHX and NaHY zeolites

International Nuclear Information System (INIS)

Kubelkova, L.; Novakova, J.

1976-01-01

Deammoniation and dehydroxylation of Na(NH 4 )X and Na(NH 4 )Y zeolites were compared. With the X type, both processes overlapped and proceeded more easily than with the Y type. Both H forms contained structural OH groups and hydroxyls denoted as SiOH, to which the 3740 cm -1 band in the IR spectrum was assigned. In addition, the NaHX zeolite contained OH groups characterized by the 3700 and 3600 cm -1 bands. Certain differences in the behaviour of NaHX and NaHY zeolites during deammoniation and dehydroxylation might be attributed to the presence of ''non-localizable'' H atoms. The active sites for the D 2 -OH exchange were probably formed during dehydroxylation. Hydrogen in SiOH groups was replaced by deuterium in both zeolite types more slowly than H atoms in other OH groups, which influenced the kinetic variations in the gaseous phase. The presence of water in the gaseous phase affected the kinetics and could distort the determination of the number of H atoms bound in the zeolites. (author)

High resolution laser spectroscopy of the D lines of on-line produced 21Na, 22Na, 24Na, 25Na using a new high sensitivity method of detection of optical resonances

International Nuclear Information System (INIS)

Huber, G.; Thibault, G.; Klapisch, R.; Duong, H.T.; Vialle, J.L.; Pinard, I.; Juncar, P.; Jacquinot, P.

1975-01-01

A polyisotopic sodium beam of 21 - 25 Na, produced by spallation of Al, was illuminated by a tunable dye laser. The atomic beam, analyzed by a sixpole magnet is then ionized and detected after a mass spectrometer. The results are the isotope shifts, nuclear magnetic moment and quadrupole moment of 25 Na [fr

OGLAŠEVANJE NA SOCIALNEM OMREŽJU FACEBOOK, NA PRIMERU SPLETICNA.SI

OpenAIRE

Reisman, Nina

2011-01-01

Internet je od svojega razvoja dolgo časa obstajal kot prostor za enostransko komunikacijo. Isto se je dogajalo na televiziji, radiu in časopisih, kjer je javnost sprejemala informacije, ki jih je nekdo pripravil. Tradicionalni mediji so hitro doumeli, da takšna vrsta komunikacije ni naravna in ne predstavlja najboljšega ohranjanja gledalcev in poslušalcev. Začela se je uporabljati dvosmerna komunikacija. Trenutno v svetu najbolje poznan primer dvosmerne komunikacije je socialno omrežje F...

FTIR spectra of the solid solutions (Na0.88K0.12)VO3, (Na0.5K0.5)VO3, and Na(V0.66P0.34)O3

Science.gov (United States)

de Waal, D.; Heyns, A. M.

1992-03-01

It is known that three different solid solutions, (Na0.88K0.12)VO3, (Na0.5K0.5)VO3 and Na(V0.66P0.34)O3, form in the (Na,K)(V,P)O3 system. These compounds all have monoclinic crystal structures similar to the pure alkali metal metavanadates containing small cations, e.g. Li+ and Na+ (Space group C2/c). Metavanadates with large cations like K+, Rb+, C+s and NH+4 form orthorhombic crystals, space group Pbcm. All those are structurally related to the silicate pyroxenes. Na(V0.66P0.34)O3 and (Na0.88K0.12)VO3 have the same modified diopside structure as (alpha) - NaVO3 while (Na0.5K0.5)VO3 adopts the true diopside structure. The infrared spectra of the three solid solutions are reported here in comparison with those of (alpha) -NaVO3 and KVO3. The results are also correlated with those obtained in two independent high pressure Raman studies of NH4VO3 and RbVO3 as the introduction of a larger cation like K+ should increase the pressure in the structure.

Medetomidīna un detomidīna hidrogēnhlorīdu struktūra noteikšana

OpenAIRE

Smuļko, Irina

2012-01-01

Medetomidīna un detomidīna hidrogēnhlorīdu struktūras noteikšana. Smuļko I., zinātniskais vadītājs Dr. ķīm., asoc. prof. Actiņš A. Maģistra darbs, 52 lappuses, 37 attēli, 6 tabulas, 29 literatūras avoti. Latviešu valodā. Maģistra darbā pētītas farmaceitiski aktīvās vielas – medetomidīna un detomidīna hidrogēnhlorīdi. Veikti mēģinājumi detomidīna bezūdens formas un monohidrāta struktūras noteikšanai, kā arī medetomidīna bezūdens formu A un B struktūras noteikšanai. Struktūras noteikšanai iz...

NAKUPOVANJE NA SPLETU

OpenAIRE

Visenjak, Monika

2013-01-01

Nakupovanje na spletu je prihodnost poslovanja. Za podjetja pomeni manjše stroške, lažje prilagajanje tržnim pogojem. Hitreje lahko razvijajo odnose in analizirajo uporabnike, saj jim je dan dostop o nakupnih podatkih uporabnika. Za potrošnike je nakupovanje na spletu možnost hitrega, preprostega in učinkovitega nakupovanja od doma ali pisarne. Pomembno je, da se seznanijo z vsemi informacijami in pogoji spletnih trgovin, saj se lahko le tako izognejo nezadovoljstvu ob nakupu v spletni trgovi...

The Na+ transporter, TaHKT1;5-D, limits shoot Na+ accumulation in bread wheat

KAUST Repository

Byrt, Caitlin Siobhan

2014-10-01

Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K+/Na+ ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na+-selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na+ concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na+ from the xylem vessels in the root and has an important role in restricting the transport of Na+ from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na+ exclusion and is critical in maintaining a high K+/Na+ ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes.

The Na+ transporter, TaHKT1;5-D, limits shoot Na+ accumulation in bread wheat

KAUST Repository

Byrt, Caitlin Siobhan; Xu, Bo; Krishnan, Mahima; Lightfoot, Damien; Athman, Asmini; Jacobs, Andrew Keith; Watson-Haigh, Nathan S.; Plett, Darren; Munns, Rana; Tester, Mark A.; Gilliham, Matthew

2014-01-01

Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K+/Na+ ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na+-selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na+ concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na+ from the xylem vessels in the root and has an important role in restricting the transport of Na+ from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na+ exclusion and is critical in maintaining a high K+/Na+ ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes.

Osmotic and ionic effects of NaCl and Na₂SO₄ salinity on Phragmites australis

DEFF Research Database (Denmark)

Pagter, Majken; Bragato, Claudia; Malagoli, Mario

2009-01-01

Osmotic and ion-specific effects of NaCl and Na2SO4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na2SO4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange....... Plants were supplied with a control standard nutrient solution (Ψ = -0.09 MPa) or solutions of NaCl or Na2SO4 at water potentials of -0.50, -1.09 or -1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S...... and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na2SO4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na2SO4, implying that a non...

Polarization and collision velocity dependence of associative ionization in cold Na (3p)-Na(3p) collisions

NARCIS (Netherlands)

Meijer, H.A.J.

1990-01-01

We studied the polarization dependence of the associative ionization (AI) process Na(3p) + Na(3p) → Na2+ at collision velocities between 100 and 700 m/s (5 and 200 K), using linearly and circularly polarized light for the excitation. We found that the polarization dependence varies strongly in the

Erythrocyte Na+/K+ ATPase activity measured with sup 23 Na NMR

Energy Technology Data Exchange (ETDEWEB)

Ouwerkerk, R.; van Echteld, C.J.; Staal, G.E.; Rijksen, G. (University Hospital, Utrecht (Netherland))

1989-11-01

A {sup 23}Na NMR assay for measurement of erythrocyte Na+/K+ ATPase activity is presented. Using the nonpermeant shift reagent dysprosium tripolyphosphate the signals of intra- and extracellular sodium are separated, enabling measurement of sodium fluxes nondestructively, without the need to physically separate the cells from their environment. By increasing membrane permeability with nystatin we have shown that the assay allows the detection of differences in membrane permeability. With low doses of nystatin the ouabain-sensitive sodium flux increased more than twofold. With high doses of nystatin the Na+/K+ pump could not prevent an almost total equilibration of intra- and extracellular sodium. All sodium that entered the cells remained NMR visible, proving that sodium influx can be measured quantitatively. {sup 31}P NMR spectra taken before and after the assay revealed a slight acidification of the cells and no significant change in ATP concentration. No evidence of Dy3+ entering the cell was observed.

Molecular dynamics investigation of Na+ in Na2Ni2TeO6

International Nuclear Information System (INIS)

Sau, Kartik; Kumar, P. Padma

2014-01-01

An inter-atomic potential for Na 2 Ni 2 TeO 6 in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na + in the system

Efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl

Directory of Open Access Journals (Sweden)

Maíra do PRADO

Full Text Available Resumo Introdução O tratamento de plasma é uma tecnologia eficaz que pode manter as propriedades internas dos materiais inalteradas após o tratamento, modificando apenas a superfície. Objetivo Avaliar o efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl 6%. Material e método Foram utilizados 60 incisivos bovinos. A coroa foi removida, a raiz foi dividida e as faces planificadas, totalizando 120 segmentos referentes ao terço cervical. As amostras foram divididas em dois grupos: controle (imersa em NaOCl 6%, lavada com água destilada, seca, imersa em EDTA 17%, lavada e seca e plasma de oxigênio (após tratamento descrito no grupo controle, plasma de oxigênio foi aplicado por 30 s. As amostras foram avaliadas qualitativamente em relação à topografia por microscopia eletrônica de varredura, utilizando-se microfotografias com ampliação de 1.000×. O goniômetro Ramé-hart foi utilizado para a mensuração do ângulo de contato entre as superfícies e as seguintes soluções foram utilizadas: água, etilenoglicol e di-iodometano. Em seguida, a energia de superfície, representada pelas componentes polar e dispersiva, foi calculada. Avaliou-se também o escoamento dos cimentos Pulp Canal Sealer EWT (PCS e Real Sal SE (RS na superfície dentinária. Os dados foram analisados estatisticamente utilizando os testes Kruskal-Wallis e Mann-Whitney U (p<0,05. Resultado O tratamento com plasma levou à formação de uma camada semelhante à smear layer na superfície dentinária. Este tratamento levou a um aumento da energia de superfície e da componente polar, favorecendo a hidrofilicidade da superfície. Entretanto, desfavoreceu o escoamento do cimento PCS e não influenciou no escoamento do cimento RS. Conclusão O plasma de oxigênio ocasionou mudanças topográficas na superfície dentinária, favorecendo a hidrofilicidade desta. Contudo, não favoreceu o escoamento dos cimentos endodônticos na dentina.

Phase formation in the systems ZrO2-H2SO4-Na2SO4 (NaCl)-H2O

International Nuclear Information System (INIS)

Sozinova, Yu.P.; Motov, D.L.; Rys'kina, M.P.

1988-01-01

Formation of solid phases in the systems ZrO 2 - H 2 SO 4 - Na 2 SO 4 (NaCl) - H 2 O at 25 and 75 deg C is studied. Three basic Na 2 Zr(OH) 2 (SO 4 ) 2 x (0.2 - 0.4)H 2 O, NaZrOH(SO 4 ) 2 x H 2 O, NaZrO 0.5 (OH) 2 SO 4 x 2H 2 O and three normal sodium sulfatozirconates Na 2 Zr(SO 4 ) 3 x 3H 2 O, Na 4 Zr(SO 4 ) 4 x 3H 2 O, Na 6 Zr(SO 4 ) 5 x 4H 2 O have been isolated, their solubility and crystal optical properties are determined

Modification of NaK (Na and K) dissolution device at the L.E.C.I

International Nuclear Information System (INIS)

Mansard, Bernard; Ducas, Serge; Riviere, Michel

1969-12-01

As three NaK dissolution devices had been operated since 1965 and as irradiation assemblies with a greater capacity (2 to 3 times) are now to be used, the modification of these dissolution devices is addressed. This requires a better control of the dissolution reaction (the NaK + alcohol reaction is highly exothermic and results in an effervescence which requires a greater volume). The objectives are therefore to delay the dissolution, to trigger it, to stop it, to control it at will, and to release heat. The new device is then described with its vessel, its cap, its ball valve, and its two tight sleeves. The operation principle is described, as well as the NaK draining process, and the NaK dissolution. Safety, time saving and raw matter saving issues are finally outlined

OGLAŠEVANJE NA FACEBOOKU V SLOVENIJI

OpenAIRE

Dobnik, Monja

2013-01-01

Danes so zahvaljujoč napredni mobilni tehnologiji družbena omrežja z nami na vsakem koraku. Facebook (FB) se po priljubljenosti uvršča v sam vrh družbenih omrežij in glede na to, da ga uporablja že več kot milijarda zemljanov, ponuja tudi odlične trg za oglaševanje. To so ugotovili tudi slovenski podjetniki. V diplomski nalogi je predstavljeno, kako na FB oglašujejo nekatera slovenska podjetja, s pomočjo spletnega vprašalnika pa je ugotovljeno tudi, kaj o oglasih na FB menijo njegovi uporabni...

Myocardial Na,K-ATPase: Clinical aspects

Science.gov (United States)

Kjeldsen, Keld

2003-01-01

The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical

Advancement of technology towards developing Na-ion batteries

Science.gov (United States)

Jamesh, Mohammed Ibrahim; Prakash, A. S.

2018-02-01

The Na-ion-batteries are considered much attention for the next-generation power-sources due to the high abundance of Na resources that lower the cost and become the alternative for the state of the art Li-ion batteries in future. In this review, the recently reported potential cathode and anode candidates for Na-ion-batteries are identified in-light-of-their high-performance for the development of Na-ion-full-cells. Further, the recent-progress on the Na-ion full-cells including the strategies used to improve the high cycling-performance (stable even up-to 50000 cycles), operating voltage (even ≥ 3.7 V), capacity (>350 mAhg-1 even at 1000 mAg-1 (based-on-mass-of-the-anode)), and energy density (even up-to 400 Whkg-1) are reviewed. In addition, Na-ion-batteries with the electrodes containing reduced graphene oxide, and the recent developments on symmetric Na-ion-batteries are discussed. Further, this paper identifies the promising Na-ion-batteries including the strategies used to assemble full-cell using hard-carbon-anodes, Na3V2(PO4)3 cathodes, and other-electrode-materials. Then, comparison between aqueous and non-aqueous Na-ion-batteries in terms of voltage and energy density has been given. Later, various types of electrolytes used for Na-ion-batteries including aqueous, non-aqueous, ionic-liquids and solid-state electrolytes are discussed. Finally, commercial and technological-developments on Na-ion-batteries are provided. The scientific and engineering knowledge gained on Na-ion-batteries afford conceivable development for practical application in near future.

Negative electrodes for Na-ion batteries.

Science.gov (United States)

Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

2014-08-07

Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

Corpo e sexualidade na gravidez

Directory of Open Access Journals (Sweden)

Natalúcia Matos Araújo

2012-06-01

Full Text Available Estudo etnográfico que teve como objetivo compreender como as gestantes vivenciam os processos fisiológicos do seu corpo durante a gestação e a sua repercussão na sexualidade. A pesquisa envolveu sete mulheres residentes em bairro popular de São Paulo. Na coleta de dados, utilizou-se observação participante e entrevista com questões norteadoras. Os dados foram apresentados na forma de narrativa e posteriormente organizados nas categorias: Percebendo as transformações corporais; Convivendo com as mudanças no corpo; Sentimentos e sensações na vida sexual durante a gestação e imaginando o corpo e a sexualidade após a gestação. As mulheres referiram-se às transformações do corpo como desconfortos e expressaram a preocupação de que fossem definitivas. Expressaram o desejo de que, após o parto, o corpo volte a ser como era e que volte a sentir desejo sexual. O reconhecimento destes fatos constitui-se numa ferramenta primordial na adequação das práticas profissionais.

Comparison of the effectiveness of seven amiloride congeners as inhibitors of Na/H and Na/Ca antiport in cultured smooth muscle cells

International Nuclear Information System (INIS)

Smith, L.; Higgins, B.L.; Cragoe, E.J. Jr.; Smith, J.B.

1987-01-01

The authors cultured smooth muscle cells from rat aorta and assayed Na/Ca antiport by measuring the initial rate of 45 Ca influx in Na-loaded cells. Na/H antiport was assayed by measuring the initial rate of 22 Na influx in acid-loaded cells. The external medium was the same for both assays except Na was 10 mM for Na/H antiport and O for the Na/Ca antiport assay. The dose of each congener that caused 50% inhibition (I 50 ) was calculated using a log-log median effect plot. The linear regression coefficients ranged from 0.916 to 0.998. Of all the compounds tested only dimethylbenzamil is more potent as an inhibitor of Na/Ca compared to Na/H antiport

Presoja notranjih kontrol pri obračunu davka na dodano vrednost na primeru "Podjetja x"

OpenAIRE

Majcen, Borut

2016-01-01

Poslovanje podjetja si je ob odsotnosti notranjih kontrol nemogoče predstavljati. Podjetja so podvržena raznim tveganjem, še posebej v današnjih razmerah globalnega poslovanja, ko se podjetja soočajo z vedno novimi izzivi, kar prinaša tudi nova tveganja. Najučinkovitejši ukrep za obvladovanje tveganj predstavlja vzpostavitev sistema notranjih kontrol. Obvladovanje tveganj pa ne poteka samo na ravni podjetja kot celote, ampak je prisotno na vseh področjih delovanja podjetja, torej tudi na p...

Culturas morais e políticas de desenvolvimento na noruega e na união europeia

Directory of Open Access Journals (Sweden)

Maria Macedo Barroso

2014-06-01

Full Text Available A partir de um diálogo entre os casos da Noruega e da União Europeia, pretendemos analisar a combinação de diferentes fatores e escalas de processos sociais (individuais, institucionais e de unidades políticas nacionais e supranacionais, estruturantes na formação dos sentidos sociais do desenvolvimento, notadamente das relações entre princípios morais e trocas interessadas, constitutivas das "culturas morais" dos universos analisados. Na perspectiva dos indivíduos, observaremos pela lente do caso da UE as motivações, vocações e histórias de vida dos "profissionais do desenvolvimento", bem como as razões da adesão da opinião pública às ações de cooperação internacional. Na escala institucional, abordaremos, nos dois casos, os modelos político-administrativos utilizados pela burocracia do desenvolvimento, e as lógicas dos diferentes grupos organizados para disputar seus recursos, no caso da Noruega. Na dimensão dos Estados, analisaremos a lógica das políticas nacionais e internacionais sob as quais são negociadas as intervenções de cooperação bilateral e/ou multilaterais tanto na Noruega quanto na UE.

Intermittent Hypoxia Inhibits Na+-H+ Exchange-Mediated Acid Extrusion Via Intracellular Na+ Accumulation in Cardiomyocytes

Directory of Open Access Journals (Sweden)

Huai-Ren Chang

2018-04-01

Full Text Available Background/Aims: Intermittent hypoxia (IH has been shown to exert preconditioning-like cardioprotective effects. It also has been reported that IH preserves intracellular pH (pHi during ischemia and protects cardiomyocytes against ischemic reperfusion injury. However, the exact mechanism is still unclear. Methods: In this study, we used proton indicator BCECF-AM to analyze the rate of pHi recovery from acidosis in the IH model of rat neonatal cardiomyocytes. Neonatal cardiomyocytes were first treated with repetitive hypoxia-normoxia cycles for 1-4 days. Cells were then acid loaded with NH4Cl, and the rate of pHi recovery from acidosis was measured. Results: We found that the pHi recovery rate from acidosis was much slower in the IH group than in the room air (RA group. When we treated cardiomyocytes with Na+-H+ exchange (NHE inhibitors (Amiloride and HOE642 or Na+-free Tyrode solution during the recovery, there was no difference between RA and IH groups. We also found intracellular Na+ concentration ([Na+]i significantly increased after IH exposure for 4 days. However, the phenomenon could be abolished by pretreatment with ROS inhibitors (SOD and phenanathroline, intracellular calcium chelator or Na+-Ca2+ exchange (NCX inhibitor. Furthermore, the pHi recovery rate from acidosis became faster in the IH group than in the RA group when inhibition of NCX activity. Conclusions: These results suggest that IH would induce the elevation of ROS production. ROS then activates Ca2+-efflux mode of NCX and results in intracellular Na+ accumulation. The rise of [Na+]i further inhibits the activity of NHE-mediated acid extrusion and retards the rate of pHi recovery from acidosis during IH.

Elastic Coulomb breakup of 34Na

Science.gov (United States)

Singh, G.; Shubhchintak, Chatterjee, R.

2016-08-01

Background: 34Na is conjectured to play an important role in the production of seed nuclei in the alternate r -process paths involving light neutron rich nuclei very near the β -stability line, and as such, it is important to know its ground state properties and structure to calculate rates of the reactions it might be involved in, in the stellar plasma. Found in the region of `island of inversion', its ground state might not be in agreement with normal shell model predictions. Purpose: The aim of this paper is to study the elastic Coulomb breakup of 34Na on 208Pb to give us a core of 33Na with a neutron and in the process we try and investigate the one neutron separation energy and the ground state configuration of 34Na. Method: A fully quantum mechanical Coulomb breakup theory within the architecture of post-form finite range distorted wave Born approximation extended to include the effects of deformation is used to research the elastic Coulomb breakup of 34Na on 208Pb at 100 MeV/u. The triple differential cross section calculated for the breakup is integrated over the desired components to find the total cross-section, momentum, and angular distributions as well as the average momenta, along with the energy-angular distributions. Results: The total one neutron removal cross section is calculated to test the possible ground state configurations of 34Na. The average momentum results along with energy-angular calculations indicate 34Na to have a halo structure. The parallel momentum distributions with narrow full widths at half-maxima signify the same. Conclusion: We have attempted to analyze the possible ground state configurations of 34Na and in congruity with the patterns in the `island of inversion' conclude that even without deformation, 34Na should be a neutron halo with a predominant contribution to its ground state most probably coming from 33Na(3 /2+)⊗ 2 p3 /2ν configuration. We also surmise that it would certainly be useful and rewarding to test our

Osmotic and activity coefficients of aqueous NaTcO4 and NaReO4 solutions at 250C

International Nuclear Information System (INIS)

Boyd, G.E.

1978-01-01

Isopiestic vapor-pressure comparison experiments were performed with aqueous binary sodium perchlorate, pertechnetate, and perrhenate solutions to concentrations of approximately 8.5 m. Osmotic coefficients for these solutions and mean molal ionic activity coefficients for NaTcO 4 and NaReO 4 were derived from the isotonic molalities. Pitzer's treatment was applied to describe the concentration dependence of the osmotic coefficients of NaClO 4 , NaTcO 4 , and NaReO 4 , and the implications of the parameters derived from a least-squares fit are discussed in terms of solvent structure and interionic forces. 4 tables, 1 figure

Energy levels of the single excited states in NaI and Na-like ions

International Nuclear Information System (INIS)

El-Sherbini, T.M.; Wahby, A.S.

1987-08-01

Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

Fabrication of implanted $^{22}$Na targets

CERN Multimedia

2002-01-01

A knowledge of the $^{22}$Na(p,$\\gamma$)$^{23}$ Mg reaction rate is of significant astrophysical interest. In order to complete previous studies of this reaction, radioactive $^{22}$Na targets of high purity are required. We ask for support to fabricate these targets via the implantation technique at ISOLDE GPS (off—line mode) using $^{22}$Na nuclides in an Al matrix produced in Nov. 1990 at the PSI (Zürich). The $^{22}$Na nuclides are released and ionized in a surface ionisation source, mass-analyzed at ISOLDE GPS, and implanted in a Ni-Ta backing and a C—foil in a special implantation setup.

Painful Na-channelopathies: an expanding universe.

Science.gov (United States)

Waxman, Stephen G

2013-07-01

The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Usmerjanje urbanega razvoja na mestni ravni

Directory of Open Access Journals (Sweden)

Mojca Šašek Divjak

1999-01-01

Full Text Available Kot je poudarjeno v predstavljenem načrtu Kopenhagna, mestni načrt ne more rešiti vseh planskih problemov mesta. Predstavljal naj bi predvideni red, ki pa se pogosto sproti podira glede na nepredvidena dogajanja v prostoru. Probleme je velikokrat treba reševati šele, ko se pokažejo. Zato mora biti mestni načrt zastavljen dovolj prilagodljivo in fleksibilno, da dovoljuje potrebne spremembe. Vendar mora kljub temu dati mestu trdne glavne usmeritve in s tem omogočiti, da meščani lahko izkoristijo priložnosti, ki jih nudi nova doba in uveljavljajo nove kvalitete bivanja.

Velocity distribution and dimer formation in a Na/Na2 beam

International Nuclear Information System (INIS)

Bergmann, K.; Hefter, U.; Hering, P.

1977-01-01

Using the TOF via optical pumping method and the Doppler-shifted laser induced emission described previously, the authors have measured the parallel and perpendicular velocity distribution respectively for Na atoms and Na 2 molecules in a variety of individual quantum states. In addition they monitored the flux of molecules in specific states while changing the stagnation pressure. In all cases a significant dependence on the internal energy of the molecules was found. The goal of these experiments is to improve understanding of the beam dynamics and the dimer formation process. (Auth.)

Angular distributions of photoelectrons from free Na clusters

International Nuclear Information System (INIS)

Wopperer, P.; Dinh, P. M.; Faber, B.; Reinhard, P.-G.; Suraud, E.

2010-01-01

We explore, from a theoretical perspective, photoelectron angular distributions (PADs) of the Na clusters Na 8 , Na 10 , Na 12 , Na 18 , Na 3 + , Na 11 + , Na 13 + , and Na 19 + . The basis of the description is the time-dependent local-density approximation (TDLDA), augmented by a self-interaction correction (SIC) to describe ionization properties correctly. The scheme is solved on a numerical grid in coordinate space with absorbing bounds. We assume for each cluster system an isotropic ensemble of free clusters and develop for the case of one-photon emission analytical formulas for computing the orientation-averaged PAD on the basis of a few TDLDA-SIC calculations for properly chosen reference orientations. It turns out that all the information in the averaged PAD is contained in one anisotropy parameter. We find that this parameter varies very little with system size, but as a whole is crucially influenced by the detailed ionic structure. We also make comparisons with direct orientation averaging and consider one example reaching outside the perturbative regime.

The Na+ transport in gram-positive bacteria defect in the Mrp antiporter complex measured with 23Na nuclear magnetic resonance.

Science.gov (United States)

Górecki, Kamil; Hägerhäll, Cecilia; Drakenberg, Torbjörn

2014-01-15

(23)Na nuclear magnetic resonance (NMR) has previously been used to monitor Na(+) translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na(+). In this work, the (23)Na NMR method was adapted for measurements of internal Na(+) concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na(+) translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na(+) concentration than an external one. Copyright © 2013 Elsevier Inc. All rights reserved.

Quatenary Na//F, Cl, CO3, MoO4 system

International Nuclear Information System (INIS)

Kochkarov, Zh.A.; Lok''yaeva, S.M.; Shurdumov, G.K.; Gasanaliev, A.M.; Trunin, A.S.

1999-01-01

Perspective in applied respect quatenary system (NaF) 2 -(NaCl)-Na 2 CO 3 -Na 2 MoO 4 being element of narrowing of more complex six-membered mutual Na//F, Cl, CO 3 , MoO 4 (WO 4 ) system is investigated by differential thermal analysis with the use of projection-thermographic method for the first time. Crystallization tree of Na//F, Cl, CO 3 , MoO 4 system is established. It is shown that this system by tetrahedrating (NaF) 2 -Na 2 CO 3 -Na 3 ClMoO 4 section is triangulated on two stable system: (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -(NaCl) 2 and (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -Na 2 MoO 4 . Phase single units are determined too. Coordinates of desired quatenary nonvariant points are calculated on analytical models of surfaces by mutual crystallization of two phases and are refined by differential thermal analysis [ru

Experimental Study of Na based Titanium Nanofluid-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

2015-10-15

In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

Energy Technology Data Exchange (ETDEWEB)

Aboussatar, Mohamed [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Mbarek, Aïcha [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieurs de Sfax, Université de Sfax, BP W3038, 3000 Sfax (Tunisia); Naili, Houcine [Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); El-Ghozzi, Malika [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Chadeyron, Geneviève [Université Clermont Auvergne, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS/UBP/SIGMA, BP 10448, F-63000 Clermont-Ferrand (France); Avignant, Daniel [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Zambon, Daniel, E-mail: Daniel.Zambon@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France)

2017-04-15

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds

Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

International Nuclear Information System (INIS)

Dolotko, Oleksandr; Zhang Haiqiao; Ugurlu, Ozan; Wiench, Jerzy W.; Pruski, Marek; Scott Chumbley, L.; Pecharsky, Vitalij

2007-01-01

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH 4 and LiNH 2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH 4 -NaNH 2 system after 60 min ball milling; and 5.2 wt.% H 2 is released when LiAlH 4 and NaNH 2 or NaAlH 4 and LiNH 2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH 4 (s) + MNH 2 (s) → 2MH(s) + AlN(s) + 2H 2 (g) was identified based on detailed spectroscopic analysis of the intermediate (M 3 AlH 6 ) and final products of the ball milling process

Makosa Yanayofanywa na Wanafunzi Wanaojifunza Kiswahili kama ...

African Journals Online (AJOL)

Makala haya, yanashughulika na makosa ambayo hufanywa na wanafunzi wanaojifunza Kiswahili kama lugha ya pili katika shule za sekondari nchini Uganda. Mtafiti ameyaainisha makosa mbalimbali na kuyaeleza kiusahihi. Makala yanaeleza namna ambavyo makosa hayo hutokea. Yaani, kama ni makosa ...

Učinak video igre "Flappy Bird" na adolescente

OpenAIRE

Horvat, Marija

2018-01-01

Ovaj diplomski rad nastoji predstaviti uvid u učinke videoigre Flappy Bird na adolescente, fokusirajući se pritom na to potiče li ona nasilno ponašanje te nastoji odgovoriti na pitanje koliko je ta videoigra bila popularna među adolescentima u Hrvatskoj te po čemu je smatraju posebnom, tj. specifičnom. U tu svrhu provedeno je anketno istraživanje, a isti anketni upitnik proveden je na terenu i putem interneta te su uspoređeni rezultati. Anketni upitnik konstruiran je na način da se prvi dio u...

Perinatal Na+ Overload Programs Raised Renal Proximal Na+ Transport and Enalapril-Sensitive Alterations of Ang II Signaling Pathways during Adulthood

Science.gov (United States)

Cabral, Edjair V.; Vieira-Filho, Leucio D.; Silva, Paulo A.; Nascimento, Williams S.; Aires, Regina S.; Oliveira, Fabiana S. T.; Luzardo, Ricardo; Vieyra, Adalberto; Paixão, Ana D. O.

2012-01-01

Background High Na+ intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na+ overload-programmed alterations in Na+ transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Methodology/Principal Findings Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na++K+)ATPase expression and activity. Ouabain-insensitive Na+-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT2 receptor expression decreased while AT1 expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na++K+)ATPase, partially recovered the response of Na+-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na+ or not. In addition, treatment with enalapril per se reduced AT2 receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na+-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Conclusions/Significance Maternal Na+ overload programmed alterations in renal Na+ transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril

alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

Science.gov (United States)

Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

2008-08-01

Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

VPLIV OSEBNOSTI NA STILE VODENJA

OpenAIRE

Vučak, Petra

2009-01-01

Nekatere naše vrline krasijo zlate lastnosti, druge pa kvarijo sivi odtenki. Če bi ljudje razumeli in spoznali svojo osebnost, ter osebnostne tipe drugih ljudi, bi se problemi pri komunikaciji občutno zmanjšali. Takrat bi namreč lažje uvideli, zakaj je nekdo reagiral na način, kot je ali zakaj je nekdo dejal to, kar je. Smisel tega je, da spoznamo svoje dobre lastnosti, ki jih lahko še bolj razvijemo, slabe pa poskušamo nadzorovati in tako zmanjšati njihov vpliv. Iskanje uspešnih in učink...

VPLIV CENE NA ZADOVOLJSTVO IN ZVESTOBO UPORABNIKOV TELEKOMUNIKACIJSKIH STORITEV

OpenAIRE

Majcen, Mateja

2016-01-01

Cena izdelka ali storitve, ki jo plača uporabnik, ima pomemben vpliv na zadovoljstvo ali nezadovoljstvo uporabnika z uporabo tega izdelka ali storitve in posledično na zadovoljstvo do podjetja. Glede na to, da se različni avtorji strinjajo in to tudi dokazujejo z raziskavami, zadovoljstvo nedvoumno vpliva na zvestobo uporabnika, zvestoba pa na dolgoročno uspešnost podjetja, smo v delu ugotavljali, kako sama cena storitve vpliva na zadovoljstvo in kako posredno preko zadovoljstva vpliva na zve...

NaI(Tl) electron energy resolution

CERN Document Server

Mengesha, W

2002-01-01

NaI(Tl) electron energy resolution eta sub e was measured using the Modified Compton Coincidence Technique (MCCT). The MCCT allowed detection of nearly monoenergetic internal electrons resulting from the scattering of incident 662 keV gamma rays within a primary NaI(Tl) detector. Scattered gamma rays were detected using a secondary HPGe detector in a coincidence mode. Measurements were carried out for electron energies ranging from 16 to 438 keV, by varying the scattering angle. Measured HPGe coincidence spectra were deconvolved to determine the scattered energy spectra from the NaI(Tl) detector. Subsequently, the NaI(Tl) electron energy spectra were determined by subtracting the energy of scattered spectra from the incident source energy (662 keV). Using chi-squared minimization, iterative deconvolution of the internal electron energy spectra from the measured NaI(Tl) spectra was then used to determine eta sub e at the electron energy of interest. eta sub e values determined using this technique represent va...

Quantitative (23) Na MRI of human knee cartilage using dual-tuned (1) H/(23) Na transceiver array radiofrequency coil at 7 tesla.

Science.gov (United States)

Moon, Chan Hong; Kim, Jung-Hwan; Zhao, Tiejun; Bae, Kyongtae Ty

2013-11-01

To develop quantitative dual-tuned (DT) (1) H/(23) Na MRI of human knee cartilage in vivo at 7 Tesla (T). A sensitive (23) Na transceiver array RF coil was developed at 7T. B1 fields generated by the transceiver array coil were characterized and corrected in the (23) Na images. Point spread function (PSF) of the (23) Na images was measured, and the signal decrease due to partial-volume-effect was compensated in [(23) Na] quantification of knee cartilage. SNR and [(23) Na] in anterior femoral cartilage were measured from seven healthy subjects. SNR of (23) Na image with the transceiver array coil was higher than that of birdcage coil. SNR in the cartilage at 2-mm isotropic resolution was 26.80 ± 3.69 (n = 7). B1 transmission and reception fields produced by the DT coil at 7T were similar to each other. Effective full-width-half-maximum of (23) Na image was ∼5 mm at 2-mm resolution. Mean [(23) Na] was 288.13 ± 29.50 mM (n = 7) in the anterior femoral cartilage of normal subjects. We developed a new high-sensitivity (23) Na RF coil for knee MRI at 7T. Our (1) H/(23) Na MRI allowed quantitative measurement of [(23) Na] in knee cartilage by measuring PSF and cartilage thickness from (23) Na and (1) H image, respectively. Copyright © 2013 Wiley Periodicals, Inc.

Razvitak naselja na kvarnerskim otocima - primjer Dobrinja

Directory of Open Access Journals (Sweden)

Marijan Bradanović

2012-12-01

Full Text Available Na dosad slabo poznatom i sa stajališta povijesti umjetnosti još posve neobrađenom primjeru Dobrinja na otoku Krku, raspravlja se o razvitku naselja na kvarnerskim otocima. Uz isticanje štetnosti dosad prevladavajućih uopćavanja, karakteristični položaj i razvitak Dobrinja tumače se u širem, komparativnom kontekstu. Analiziraju se prostiranje i obilježja pojedinih dijelova ovog naselja, a naglasak je na vremenu kasnog srednjeg i ranijeg novog vijeka. Tada je najuži dio povijesnog središta Dobrinja poprimio čvrstu, na tlorisnoj osnovi i danas, usprkos opsežnim pregradnjama i arhitektonskim preinakama, jasno uočljivu, urbanu fizionomiju.

Investigation of sodalites for conditioning halide salts (NaCl and NaI): Comparison of two synthesis routes

Energy Technology Data Exchange (ETDEWEB)

Bardez, Isabelle; Campayo, Lionel; Rigaud, Danielle; Chartier, Myriam; Calvet, Aurelie [CEA, Laboratoire d' Etudes des Materiaux Ceramiques pour le Conditionnement, Site de Marcoule, Batiment 208, B.P. 17171, 30207 Bagnols sur Ceze cedex (France)

2008-07-01

Sodalites with the general formula Na{sub 8}Al{sub 6}Si{sub 6}O{sub 24}X{sub 2} (where X = Cl or I) were investigated for ceramic conditioning of halide salts (NaCl and NaI). Because of the tendency of halides to volatilize at high temperature, two synthesis routes were tested to optimize the halide content in the sodalite phase. The first is based on heating at high temperature of a [nepheline NaAlSiO{sub 4} + salt] mixture prepared by a dry process. The second, performed at low temperature, consists of the reaction in aqueous media between kaolinite (Al{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}), sodium hydroxide (NaOH) and the salt. The present study compares these two syntheses and examines differences between chloro-sodalite and iodo-sodalite based on X-ray diffraction and infrared spectroscopy. The next step will consist in sintering the resulting powder samples to obtain dense ceramics. (authors)

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO3 and NaNO2 on the dissolution time

International Nuclear Information System (INIS)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O.

2011-01-01

Faced with global crisis in the production of radioisotope 99 Mo, which product of decay, 99 mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain 99 Mo from irradiated UA1 x -A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of 99 Mo and 99 mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1 x -A1 targets. Al corresponds to about 79% of the total weight of the UA1 x -A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L -1 NaOH, b) 3 mol.L -1 NaOH/NaNO 3 and c) 3 mol.L -1 NaOH/NaNO 2 , keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO 3 or NaNO 2 in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

Science.gov (United States)

Shrivastava, Navadeep; Rocha, Uéslen; Muraca, Diego; Jacinto, Carlos; Moreno, Sergio; Vargas, J. M.; Sharma, S. K.

2018-05-01

Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (˜ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (˜ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (˜ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.

The plant vacuolar Na+/H+ antiport.

Science.gov (United States)

Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

1994-01-01

Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

Correlation of the Na2SiO3 to NaOH Ratios and Solid to Liquid Ratios to the Kedah’s Soil Strength

Directory of Open Access Journals (Sweden)

Nur Hamzah Hazamaah

2016-01-01

Full Text Available Geopolymer was used for the soil stabilization of Kedah’s soil at different ratios of solid to liquid and Na2SiO3 to NaOH in order to achieve the desired compressive strength. The geopolymerization process which produces an aluminosilicate gel was occurred due to the mixing of Kedah’s soil and fly ash with Na2SiO3 and NaOH. Soil stabilization by geopolymer was synthesized by the activation of fly ash and Kedah’s soil with Na2SiO3 and NaOH at different ratios of solid to liquid (1.5, 2.0, 2.5 and 3.0 and Na2SiO3 to NaOH (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 at a specific constant concentration of NaOH solution of 6M. The compressive strength up to 5.12 MPa was obtained at 3.0 of solid to liquid ratio and 2.5 of Na2SiO3 to NaOH ratio in 7 days curing at room temperature.

Near resonant charge transfer in Na(4D)+K+ → Na++K*: Optical pumping of the Na(4D) state and energy dependence of rank 4 alignment

International Nuclear Information System (INIS)

Campbell, E.E.B.; Huelser, H.; Witte, R.; Hertel, I.V.

1990-01-01

Rank 4 alignment has been observed in a quasi one electron system. Relative charge transfer cross sections of the Na 4dσ, 4dπ and 4dδ sublevels for the K + +Na(4D)→K * +Na + system have been measured. A strong energy dependence is observed. The results at energies less than 1 keV may be attributed to rotational coupling of the Na 4dπ state to the K 4fδ state. The Na atom is excited in a two-step process, the first step being excitation to the 3 2 P 3/2 level with a two-mode laser to pump from both hyperfine levels of the ground state simultaneously. This two-mode laser is described in detail. The optical pumping problem is solved using rate equations. The general formula for describing the scattering intensity for cylindrical symmetry, in terms of multipole moments, for atoms excited by two linearly polarised lasers is derived and used to evaluate the experimental results. (orig.)

Thermodynamic description of Tc(iv) solubility and carbonate complexation in alkaline NaHCO3-Na2CO3-NaCl systems.

Science.gov (United States)

Baumann, A; Yalçıntaş, E; Gaona, X; Polly, R; Dardenne, K; Prüßmann, T; Rothe, J; Altmaier, M; Geckeis, H

2018-03-28

The solubility of 99 Tc(iv) was investigated in dilute to concentrated carbonate solutions (0.01 M ≤ C tot ≤ 1.0 M, with C tot = [HCO 3 - ] + [CO 3 2- ]) under systematic variation of ionic strength (I = 0.3-5.0 M NaHCO 3 -Na 2 CO 3 -NaCl-NaOH) and pH m (-log[H + ] = 8.5-14.5). Strongly reducing conditions (pe + pH m ≈ 2) were set with Sn(ii). Carbonate enhances the solubility of Tc(iv) in alkaline conditions by up to 3.5 log 10 -units compared to carbonate-free systems. Solvent extraction and XANES confirmed that Tc was kept as +IV during the timeframe of the experiments (≤ 650 days). Solid phase characterization performed by XAFS, XRD, SEM-EDS, chemical analysis and TG-DTA confirmed that TcO 2 ·0.6H 2 O(am) controls the solubility of Tc(iv) under the conditions investigated. Slope analysis of the solubility data in combination with solid/aqueous phase characterization and DFT calculations indicate the predominance of the species Tc(OH) 3 CO 3 - at pH m ≤ 11 and C tot ≥ 0.01 M, for which thermodynamic and activity models are derived. Solubility data obtained above pH m ≈ 11 indicates the formation of previously unreported Tc(iv)-carbonate species, possibly Tc(OH) 4 CO 3 2- , although the likely formation of additional complexes prevents deriving a thermodynamic model valid for this pH m -region. This work provides the most comprehensive thermodynamic dataset available for the system Tc 4+ -Na + -Cl - -OH - -HCO 3 - -CO 3 2- -H 2 O(l) valid under a range of conditions relevant for nuclear waste disposal.

Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin

International Nuclear Information System (INIS)

Sopjani, Mentor; Alesutan, Ioana; Wilmes, Jan; Dermaku-Sopjani, Miribane; Lam, Rebecca S.; Koutsouki, Evgenia; Jakupi, Muharrem; Foeller, Michael; Lang, Florian

2010-01-01

Research highlights: → The oncogenic transcription factor β-catenin stimulates the Na + /K + -ATPase. → β-Catenin stimulates SGLT1 dependent Na + , glucose cotransport. → The effects are independent of transcription. → β-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: β-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. β-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that β-catenin influences membrane transport. To this end, β-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of β-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na + /K + -ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of β-catenin on the endogenous Na + /K + -ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of β-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of β-catenin expression. The stimulating effect of β-catenin on both Na + /K + ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of β-catenin, i.e. the regulation of transport.

Explosive phenomena in heavily irradiated NaCl

NARCIS (Netherlands)

denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

1997-01-01

In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

Crystallographic characterization of cement pastes hydrated with NaCl; Caracterizacao cristalografica de pastas de cimento hidratadas com NaCl

Energy Technology Data Exchange (ETDEWEB)

Melo, Carina Gabriela de Melo e; Martinelli, Antonio Eduardo; Melo, Dulce Maria Araujo; Melo, Marcus Antonio de Freitas; Melo, Vitor Rodrigo de Melo e [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2012-07-01

One of the major current challenges faced by oil companies is the exploration of pre salt basins. Salt layers deposited upon the evaporation of ocean water and continental separation are mainly formed by NaCl and isolate immense oil reservoirs. The mechanical stability and zonal isolation of oil wells that run through salt layers must be fulfilled by cement sheaths saturated with NaCl to assure chemical compatibility between cement and salt layer. The present study aimed at evaluating the effect of NaCl addition on the hydration of oil well cement slurries as well as identifying the nature of crystalline phases present in the hardened cement. To that end, cement slurries containing NaCl were mixed, hardened and characterized by X-ray diffraction. The results revealed that the presence of NaCl affects the formation of hydration products by the presence of Friedel's salt. The intensity of the corresponding peaks increase as the contents of NaCl in the slurry increase. High concentrations of NaCl in Portland slurries increase the setting time of cement and the presence of Friedel's salt decreases the strength of the hardened cement. (author)

Estereótipos na comunicação intercultural: o caso do intercâmbio cultural na PUCRS

OpenAIRE

Espindola, Polianne Merie

2010-01-01

Este é um estudo da estereotipia existente na comunicação intercultural. O objetivo é entender a natureza do estereótipo mental e seu papel na comunicação entre interlocutores de culturas distintas. Para tanto, observa os estudantes estrangeiros em programas de intercâmbio no campus da Pontifícia Universidade Católica do Rio Grande do Sul. O estudo define o conceito de estereótipo e explicita seu papel na comunicação intercultural; verifica sua relevância na construção das narrativas entre cu...

VPLIV ULCEROZNEGA KOLITISA NA KAKOVOST ŽIVLJENJA

OpenAIRE

Dugi, Maja

2015-01-01

Pri vsaki bolezni je zelo pomembna kakovost življenja pacientov. Ulcerozni kolitis je kronična bolezen, ki je znana po obdobjih mirovanja in izbruhov, kar definitivno vpliva na posameznika, ki se s tem spopada. Sooča se z raznimi omejitvami, ki vplivajo na njegov vsakdan. Rezultati raziskave so pokazali, da je kakovost življenja bolnikov z ulceroznim kolitisom izrazito okrnjena. Ne le, da se spopadajo z bolečino, ampak tudi s psihičnimi in socialnimi posledicami, ki vplivajo na fizične aktivn...

Análise do efeito imunomodulador da ouabaína na inflamação e nocicepção

OpenAIRE

Vasconcelos, Danielle Ingrid Bezerra de

2011-01-01

A Ouabaína é um glicosídeo cardiotônico, inibidor da Na+/K+-ATPase, utilizada na clínica para o tratamento de insuficiência cardíaca. Atualmente, sabe-se que essa substância é endógena, e capaz de interferir em várias funções fisiológicas, inclusive em diversos aspectos do sistema imunológico. Apesar disso, pouco se sabe sobre seu envolvimento em processos inflamatórios e nociceptivos. Neste trabalho, foi avaliada a atividade da Ouabaína na inflamação aguda desencadeada pela ad...

Erythrocyte 22Na+ influx in hypertension

International Nuclear Information System (INIS)

Shalev, O.; Eaton, J.W.; Ben-Ishay, D.

1984-01-01

We assessed 22Na+ uptake by erythrocytes (RBC) from 38 individuals with essential hypertension and 37 healthy controls. All subjects were male, white, non-obese and with normal renal function, obviating sex, race, hormonal, ponderal and renal factors known to influence RBC Na+ handling. The mean +/- sem 22Na+ uptake of the patients was 284 +/- 16 mumole/liter RBC/hour while that of normal controls was 249 +/- 11 mumole/liter RBC/hour; although the difference reached borderline significance, individual values showed considerable overlap. Consequently, in our population, RBC 22Na+ uptake is not a reliable marker for essential hypertension. We believe that previous studies should be reassessed with regard to patients' characteristics and future studies employ rigorous criteria in selection of subjects

O grotesco na imagem publicitária

OpenAIRE

Silva, Maria João Barros

2013-01-01

O significado da palavra grotesco teve um começo puramente artístico numa descoberta, de imagens de figuras humanas deformadas e alteradas. No entanto, este foi evoluindo e adotando novos significados mais amplos e concretos na atualidade. É possível encontrar vários exemplos do grotesco em várias plataformas, como no cinema, na televisão e na literatura. Neste sentido, para se poder proceder ao estudo desta temática é fundamental a conquista do conhecimento sobre o estatuto do grotesco na pu...

Gravidez na adolescência: tendência na produção científica de enfermagem

OpenAIRE

Gurgel, Maria Glêdes Ibiapina; Alves, Maria Dalva Santos; Vieira, Neiva Francenely Cunha; Pinheiro, Patrícia Neyva da Costa; Barroso, Grasiela Teixeira

2008-01-01

A gravidez em adolescentes tem implicações biológica, psicológica, social, econômica e cultural. O estudo exploratório, descritivo e bibliográfico objetivou identificar as concepções da gravidez na adolescência, sujeito, vulnerabilidade e gênero, presentes na produção científica de Enfermagem. Foram selecionados intencionalmente quatro periódicos brasileiros e dois da América Latina indexados de 2002 a 2006 na Scientific Electronic Library. Dos 1.472 artigos identificados, 43 tinham como temá...

Neutralization of Na2PO4: Reaction between Na3PO4 and CaCL2

International Nuclear Information System (INIS)

Xia Shenglan; Wang Luning

1990-01-01

The results of reaction Na 3 PO 4 with CaCl 2 in water at ambient and higher temperature are described. The reaction rate of Na 3 PO 4 with CaCl 2 is slow at ambient temperature and the reaction is complete at 260 deg C after 2 h. The products are Ca(OH) 2 and Ca 5 (PO 4 ) 3 (OH). The quantity of them is dependent upon the quanity of Na 3 PO 4 and CaCl 2 contained in water, all of them control pH of water

Raman scattering and lattice stability of NaAlH{sub 4} and Na{sub 3}AlH{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Yukawa, H. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)], E-mail: hiroshi@numse.nagoya-u.ac.jp; Morisaku, N.; Li, Y.; Komiya, K.; Rong, R.; Shinzato, Y. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan); Sekine, R. [Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Shizuoka 422-8529 (Japan); Morinaga, M. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)

2007-10-31

In situ Raman spectroscopy measurements have been performed during the decomposition of NaAlH{sub 4} in order to investigate the transition from the four-coordinated complex anion, [AlH{sub 4}]{sup -}, in NaAlH{sub 4} to the six-coordinated complex anion, [AlH{sub 6}]{sup 3-}, in Na{sub 3}AlH{sub 6}. Also, the local geometry and the Al-H vibrations are analyzed theoretically by the first-principle calculations of the electronic structures. It is found that the Raman sift at 1765 cm{sup -1} for the Al-H stretching vibration in NaAlH{sub 4} shifts towards the higher frequency side, 1801 cm{sup -1} upon melting. This Raman spectrum for the liquid phase recovers to the original position when it is cooled down to room temperature before Na{sub 3}AlH{sub 6} start to appear. The Raman peak around 1800 cm{sup -1} is still observed after the decomposition of NaAlH{sub 4} occurs to precipitate Na{sub 3}AlH{sub 6}. However, this peak does not recover to its original position by cooling, but still persists in the sample cooled down to room temperature. From these results, the intermediate transition state during the decomposition of NaAlH{sub 4} into Na{sub 3}AlH{sub 6} is discussed. In addition, it is shown from a series of calculation that the highest frequency of the Al-H vibration correlates with the shortest Al-H bond length in the MAlH{sub 4}-type and its derivative complex hydrides.

Predstave o seksu u filmovima na temu postapokalipse

Directory of Open Access Journals (Sweden)

Ana Banić-Grubišić

2016-03-01

Full Text Available Rad se bavi načinima predstavljanja seksualnih odnosa u filmovima na temu postapokalipse. Razmatraju se različiti oblici/vrste seksualnih veza, koje se javljaju u postkataklizmičnom okruženju, u odnosu na dva tipa zajednica/društava koja nastaju nakon kraja sveta. Ti filmovi pokazuju koliko je ideja o nagonskoj, prirodnoj, biološkoj seksualnosti raširena u popularnoj imaginaciji – seks je u postapokalipsi predstavljen kao pokretačka sila, na isti način kao što je to i glad.

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

Science.gov (United States)

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Robust high pressure stability and negative thermal expansion in sodium-rich antiperovskites Na3OBr and Na4OI2

International Nuclear Information System (INIS)

Wang, Yonggang; Wen, Ting; Park, Changyong; Kenney-Benson, Curtis; Pravica, Michael; Zhao, Yusheng; Yang, Wenge

2016-01-01

The structure stability under high pressure and thermal expansion behavior of Na 3 OBr and Na 4 OI 2 , two prototypes of alkali-metal-rich antiperovskites, were investigated by in situ synchrotron X-ray diffraction techniques under high pressure and low temperature. Both are soft materials with bulk modulus of 58.6 GPa and 52.0 GPa for Na 3 OBr and Na 4 OI 2 , respectively. The cubic Na 3 OBr structure and tetragonal Na 4 OI 2 with intergrowth K 2 NiF 4 structure are stable under high pressure up to 23 GPa. Although being a characteristic layered structure, Na 4 OI 2 exhibits nearly isotropic compressibility. Negative thermal expansion was observed at low temperature range (20–80 K) in both transition-metal-free antiperovskites for the first time. The robust high pressure structure stability was examined and confirmed by first-principles calculations among various possible polymorphisms qualitatively. The results provide in-depth understanding of the negative thermal expansion and robust crystal structure stability of these antiperovskite systems and their potential applications

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

International Nuclear Information System (INIS)

Somera, L.; Cruz Z, E.; Roman L, J.; Hernandez A, J. M.; Murrieta S, H.

2015-10-01

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl 2 ) impurity were grown by using the Czochralski method. The emission characteristic of Mn 2+ was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from 60 Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Somera, L.; Cruz Z, E.; Roman L, J. [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Hernandez A, J. M.; Murrieta S, H., E-mail: ecruz@nucleares.unam.mx [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

2015-10-15

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl{sub 2}) impurity were grown by using the Czochralski method. The emission characteristic of Mn{sup 2+} was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from {sup 60}Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Occlusion of /sup 22/Na+ and /sup 86/Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-08-05

In this work, we examined occlusion of /sup 22/Na+ and /sup 86/Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of /sup 22/Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of /sup 22/Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by /sup 32/P incorporation from (gamma-/sup 32/P)CrATP. Maximum capacity for phosphorylation from (gamma-/sup 32/P)CrATP was 6 nmol/mg of protein and equal to capacities for binding of (48V)vanadate and (/sup 3/H)ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport.

Europlanet NA2 Science Networking

Science.gov (United States)

Harri, Ari-Matti; Szego, Karoly; Genzer, Maria; Schmidt, Walter; Krupp, Norbert; Lammer, Helmut; Kallio, Esa; Haukka, Harri

2013-04-01

Europlanet RI / NA2 Science Networking [1] focused on determining the major goals of current and future European planetary science, relating them to the Research Infrastructure that the Europlanet RI project [2] developed, and placing them in a more global context. NA2 also enhanced the ability of European planetary scientists to participate on the global scene with their own agenda-setting projects and ideas. The Networking Activity NA2 included five working groups, aimed at identifying key science issues and producing reference books on major science themes that will bridge the gap between the results of present and past missions and the scientific preparation of the future ones. Within the Europlanet RI project (2009-2012) the NA2 and NA2-WGs organized thematic workshops, an expert exchange program and training groups to improve the scientific impact of this Infrastructure. The principal tasks addressed by NA2 were: • Science activities in support to the optimal use of data from past and present space missions, involving the broad planetary science community beyond the "space club" • Science activities in support to the preparation of future planetary missions: Earth-based preparatory observations, laboratory studies, R&D on advanced instrumentation and exploration technologies for the future, theory and modeling etc. • Develop scientific activities, joint publications, dedicated meetings, tools and services, education activities, engaging the public and industries • Update science themes and addressing the two main scientific objectives • Prepare and support workshops of the International Space Science Institute (ISSI) in Bern and • Support Trans National Activities (TNAs), Joined Research Activities (JRAs) and the Integrated and Distributed Information Service (IDIS) of the Europlanet project These tasks were achieved by WG workshops organized by the NA2 working groups, by ISSI workshops and by an Expert Exchange Program. There were 17 official WG

NA61/SHINE ion program

CERN Document Server

Mackowiak, Maja

2010-01-01

The Super Proton Synchrotron (SPS) at CERN covers one of the most interesting regions of the phase diagram (T - \\mu_{B}) of strongly interacting matter. The study of central Pb+Pb collisions by NA49 indicate that the threshold for deconfinement is reached already at the low SPS energies. Theoretical considerations predict a critical point of strongly interacting matter at energies accessible at the SPS. The NA61/SHINE experiment, a successor of the NA49 project, will study hadron production in p+p, p+A, h+A, and A+A reactions at various energies. The broad physics program includes the investigation of the properties of strongly interacting matter, as well as precision measurements of hadron spectra for the T2K neutrino experiment and for the Pierre Auger Observatory and KASCADE cosmic-ray projects. The main physics goals of the NA61/SHINE ion program are to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. To ach...

Armas na escola: que fazer?

Directory of Open Access Journals (Sweden)

Raymundo de Lima

2010-09-01

Full Text Available

Um aluno portava um revólver na sala de aula de uma escola de Maringá (O Diário, 30/07/2010. Ele pegou arma do pai, sem que este soubesse, para se proteger de garotos que o intimidavam. Trata-se de um caso isolado ou é hora de a escola tomar medidas preventivas? Semanas antes, tiros foram disparados dentro de uma faculdade da mesma cidade. O autor dos disparos está preso, e a faculdade tenta apagar as marcas com publicidade positiva na Tv. Em Campo Mourão, cidade a cerca de uma hora de Maringá, duas meninas foram mortas e enterradas na escola.

Isotope separation of 22Na and 24Na with using light induced drift effect

International Nuclear Information System (INIS)

Hradecny, C.; Tethal, T.; Ermolaev, I.M.; Zemlyanoj, S.G.; Zuzaan, P.

1993-01-01

The LIDIS (Light Drift Isotope Separation) separator without a gas flow is discussed. It is shown, that atomization degree of the separated isotopes limited real separation coefficient. The better buffer gas purification allowed to increase the experimental separation factor of 22 Na and 24 Na isotopes up to 25. The new experimental set up allow to increase the separation efficiency up to 50%. 12 refs.; 5 figs

MOBILNO POSLOVANJE NA PRIMERU UPORABE MICROSOFT DYNAMICS CRM

OpenAIRE

Duh, Tamara

2016-01-01

Hitro razvijajoči se svet nas spodbuja k hitremu reagiranju na novosti, ki se pojavljajo na trgu. Prav zaradi tega je danes zelo pomembno upravljati z mobilnimi napravami, da se lahko hitro in brez težav soočimo z morebitnimi težavami oz. zagatami. Prav iz tega razloga je mobilno poslovanje ena izmed inovativnih rešitev, ki ljudem omogoča seznanjenost z informacijami na vsakem koraku in omogoča hiter odziv na spremembe. Prav ta rešitev omogoča podjetjem, da so konkurenčna in hkrati lahko hitr...

Usando a antimatéria na medicina moderna

OpenAIRE

Machado,A.C.B.; Pleitez,V.; Tijero,M.C.

2006-01-01

Neste artigo, fazemos uma breve exposição de como um dos conceitos fundamentais da física moderna, a existência de antimatéria, tem aplicação na medicina, na chamada tomografia por emissão de pósitrons (PET na sigla em inglês). Ela consiste na produção de imagens tomográficas digitais do organismo que são obtidas pela detecção da radiação produzida na aniquilação do pósitron com o elétron.

43. Calmodulin regulating calcium sensitivity of Na channels

Directory of Open Access Journals (Sweden)

R. Vegiraju

2016-07-01

Full Text Available By extrapolating information from existing research and observing previous assumptions regarding the structure of the Na Channel, this experiment was conducted under the hypothesis that the Na Channel is in part regulated by the calmodulin protein, as a result proving calcium sensitivity of the Na Channel. Furthermore, we assume that there is a one to one stoichiometry between the Na Channel and the Calmodulin. There has been extensive research into the functionality and structure of sodium ion channels (Na channels, as several diseases are associated with the lack of regulation of sodium ions, that is caused by the disfunction of these Na channels. However, one highly controversial matter in the field is the importance of the protein calmodulin (CaM and calcium in Na channel function. Calmodulin is a protein that is well known for its role as a calcium binding messenger protein, and that association is believed to play an indirect role in regulating the Na channel through the Na channel’s supposed calcium sensitivity. While there are proponents for both sides, there has been relatively little research that provides strong evidence for either case. In this experiment, the effect of calmodulin on NaV 1.5 is tested by preparing a set of cardiac cells (of the human specie with the NaV 1.5 C-Termini and CaM protein, which were then to be placed in solutions with varying concentrations of calcium. We took special care to test multiple concentrations of calcium, as previous studies have tested very low concentrations, with Manu Ben-Johny’s team from the John Hopkins laboratory in particular testing up to a meager 50 micromolar, despite producing a well-respected paper (By comparison, the average Na channel can naturally sustain a concentration of almost 1-2 millimolar and on some occasions, reaching even higher concentrations. After using light scattering and observing the signals given off by the calcium interacting with these Nav1.5/Ca

In vivo PTH provokes apical NHE3 and NaPi2 redistribution and Na-K-ATPase inhibition

DEFF Research Database (Denmark)

Zhang, Y; Norian, J M; Magyar, C E

1999-01-01

and to determine whether the same cellular signals drive the changes in apical and basolateral transporters. PTH-(1-34) (20 U), which couples to adenylate cyclase (AC), phospholipase C (PLC), and phospholipase A2 (PLA2), or [Nle8,18,Tyr34]PTH-(3-34) (10 U), which couples to PLC and PLA2 but not AC, were given....../diuresis and NHE3 and NaPi2 internalization, and that Na-K-ATPase inhibition is not secondary to depressed apical Na+ transport....

Aspectos valorizados por porfissionais de enfermagem na higiene pessoal e na higiene corporal do paciente

Directory of Open Access Journals (Sweden)

Elóide André Oliveira

2003-10-01

Full Text Available Survey descritivo, com o qual se objetivou identificar que aspectos da higiene corporal são valorizados pelos componentes da equipe de enfermagem, na higiene corporal pessoal e na higiene corporal do paciente. A pesquisa foi desenvolvida em oito instituições públicas de saúde e a amostra foi composta por 126 profissionais de enfermagem, correspondendo a 12,8% do total de 986 componentes das equipes de enfermagem destas instituições. Na higiene corporal pessoal, chamou a atenção o fato de que os cuidados com as unhas e com os cabelos tenham suplantado, no número de citações dos profissionais de enfermagem, aspectos básicos como o cuidado com as mãos. Na higiene corporal do paciente, o banho foi o aspecto considerado mais importante pelas três categorias profissionais; a higiene oral, pelas(os enfermeiras(os e auxiliares de enfermagem; e as unhas, pelas(os enfermeiras(os e técnicas(os de enfermagem.

Modulation of contraction by intracellular Na+ via Na(+)-Ca2+ exchange in single shark (Squalus acanthias) ventricular myocytes.

Science.gov (United States)

Näbauer, M; Morad, M

1992-01-01

1. The effect of direct alteration of intracellular Na+ concentration on contractile properties of whole-cell clamped shark ventricular myocytes was studied using an array of 256 photodiodes to monitor the length of the isolated myocytes. 2. In myocytes dialysed with Na(+)-free solution, the voltage dependence of Ca2+ current (ICa) and contraction were similar and bell shaped. Contractions activated at all voltages were completely suppressed by nifedipine (5 microM), and failed to show significant tonic components, suggesting dependence of the contraction on Ca2+ influx through the L-type Ca2+ channel. 3. In myocytes dialysed with 60 mM Na+, a ICa-dependent and a ICa-independent component of contraction could be identified. The Ca2+ current-dependent component was prominent in voltages between -30 to +10 mV. The ICa-independent contractions were maintained for the duration of depolarization, increased with increasing depolarization between +10 to +100 mV, and were insensitive to nifedipine. 4. In such myocytes, repolarization produced slowly decaying inward tail currents closely related to the time course of relaxation and the degree of shortening prior to repolarization. 5. With 60 mM Na+ in the pipette solution, positive clamp potentials activated decaying outward currents which correlated to the size of contraction. These outward currents appeared to be generated by the Na(+)-Ca(2+)-exchanger since they depended on the presence of intracellular Na+, and were neither suppressed by nifedipine nor by K+ channel blockers. 6. The results suggest that in shark (Squalus acanthias) ventricular myocytes, which lack functionally relevant Ca2+ release pools, both Ca2+ channel and the Na(+)-Ca2+ exchanger deliver sufficient Ca2+ to activate contraction, though the effectiveness of the latter mechanism was highly dependent on the [Na+]i. PMID:1338467

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

Science.gov (United States)

Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

2016-09-01

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

KANDUNGAN NATRIUM (Na DAN GARAM (NaCl DALAM IKAN ASIN KERING MENTAH DAN GORENG DI PASAR ANYAR BOGOR

Directory of Open Access Journals (Sweden)

Heru Yuniati

2012-11-01

Full Text Available Telah dilakukan penelitian untuk mengetahui kandungan natrium (Na dan garam (NaCl dalam 10 jenis ikan asin kering yang beredar di Pasar Anyar Bogor. Analisis natrium dilakukan terhadap ikan asin mentah, setelah dicuci, dan setelah digoreng dengan menggunakan flamefometer. Analisis garam dilakukan dengan titrasi argentometri terhadap ikan asin mentah. Hasil analisis menunjukkan, kandungan Na dan garam dalam ikan asin sangat beragam besarnya berturut-turut berkisar antara 0,3-8,1% dan 5,7-21,2%. Ikan asin yang mempunyai kadar Na dan garam tinggi adalah ikan sepat, peda putih dan gabus. Jumlah air dalam ikan asin juga bervariasi, berkisar antara 10,3-46,8%. pencucian dan penggorengan dapat menurunkan kadar garam ataupun natrium sebesar 37,4%.

Aprendizagem como/na prática

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Jean Lave

2015-12-01

Full Text Available ResumoEste artigo considera como o estudo da cultura e da aprendizagem pode ser de particular relevância para o campo da antropologia sociocultural em geral. O termo mais importante na expressão “cultura & aprendizagem” talvez seja o logograma “&” – ou seja, coloca-se a questão sobre o que conecta cultura e aprendizagem, perguntando-se como esses termos estão relacionados. Como devemos compreender cultura e aprendizagem como instâncias produtoras delas próprias, e uma da outra, na prática? Recalibrando em termos relacionais, podemos dizer que não é possível abordar a “aprendizagem” ou “cultura e aprendizagem” sem o seu emaranhamento na vida político-econômica, nas lutas e disputas históricas, em suas coerências e incoerências, e na produção relacional e histórica da vida cotidiana. Através das lentes da teoria da prática social, os estudos etnográficos sobre aprendizagem na prática oferecem diferentes entendimentos sobre como certa vida e certas disputas e incoerências são produzidas.

Metodologija analize stroškov in koristi za investicije v prometno infrastrukturo na osnovi Poročila vplivov na okolje

OpenAIRE

Podvornik, Nina

2016-01-01

Povečane potrebe po prometnem omrežju vodijo k dodatnim prometnim investicijam, ki so ne glede na njihov obseg, postavitev v prostor ter učinkovitost pomemben dejavnik gospodarskega razvoja. Investicije v prometno infrastrukturo lahko na sam razvoj vplivajo pozitivno (dvig gospodarske rasti, kakovost življenja, dostopnost idr.) in tudi negativno (različni vplivi na okolje). Ker so prometne investicije zelo obsežne, je vsestranska ocena le-teh ključnega pomena pri samem prometnem načrtovanju v...

Agmag Igbo dka Ngwar n'kwalite Ezi Nchekwa na Nkwsiike haobodo

African Journals Online (AJOL)

Ka Najira nwerechara onwe ya n'af 1960, olileanya tt mamala ya b na ihe ga-adz mma. Mana ka oge na-aga, a chptara na ihe na-akawanye nj. Usoro chch d iche iche daptara. Nd am na nd nkt achala mana nd gara n'ihu na-akawanye nj. O bu ihe doro anya na chch ha b nke nchgbu na fnfju akpa. N'agbanyegh na ...

Regulation of Epithelial Sodium Transport via Epithelial Na+ Channel

Science.gov (United States)

Marunaka, Yoshinori; Niisato, Naomi; Taruno, Akiyuki; Ohta, Mariko; Miyazaki, Hiroaki; Hosogi, Shigekuni; Nakajima, Ken-ichi; Kusuzaki, Katsuyuki; Ashihara, Eishi; Nishio, Kyosuke; Iwasaki, Yoshinobu; Nakahari, Takashi; Kubota, Takahiro

2011-01-01

Renal epithelial Na+ transport plays an important role in homeostasis of our body fluid content and blood pressure. Further, the Na+ transport in alveolar epithelial cells essentially controls the amount of alveolar fluid that should be kept at an appropriate level for normal gas exchange. The epithelial Na+ transport is generally mediated through two steps: (1) the entry step of Na+ via epithelial Na+ channel (ENaC) at the apical membrane and (2) the extrusion step of Na+ via the Na+, K+-ATPase at the basolateral membrane. In general, the Na+ entry via ENaC is the rate-limiting step. Therefore, the regulation of ENaC plays an essential role in control of blood pressure and normal gas exchange. In this paper, we discuss two major factors in ENaC regulation: (1) activity of individual ENaC and (2) number of ENaC located at the apical membrane. PMID:22028593

Na+,K+ pumpen vedbliver at overraske

DEFF Research Database (Denmark)

Vilsen, Bente

2008-01-01

This article provides an overview of news about the Na+,K+ pump, an indispensable enzyme whose protein structure has been described in a recent article in Nature, 50 years after its discovery. In combination with mutational analysis, the structure reveals the binding pocket for the K+ ions...... and the regulation of Na+ transport by a strategically located C-terminus of the protein. Focus is also on the pathophysiology of two neurological disorders, familial hemiplegic migraine and rapid-onset dystonia-parkinsonism, recently shown to be caused by mutations in the Na+,K+-ATPase. Udgivelsesdato: may 19...

Risbjerg: Historisk stemmeskred med NA

DEFF Research Database (Denmark)

Thomsen, Søren Risbjerg

2007-01-01

ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007......ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007...

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO{sub 3} and NaNO{sub 2} on the dissolution time

Energy Technology Data Exchange (ETDEWEB)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O., E-mail: rcamilo@ipen.br, E-mail: icaraujo@ipen.br, E-mail: acmindri@ipen.br, E-mail: cforbici@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN/SP), Sao Paulo, SP (Brazil)

2011-07-01

Faced with global crisis in the production of radioisotope {sup 99}Mo, which product of decay, {sup 99}mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain {sup 99}Mo from irradiated UA1{sub x}-A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of {sup 99}Mo and {sup 99}mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1{sub x}-A1 targets. Al corresponds to about 79% of the total weight of the UA1{sub x}-A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L{sup -1} NaOH, b) 3 mol.L{sup -1} NaOH/NaNO{sub 3} and c) 3 mol.L{sup -1} NaOH/NaNO{sub 2}, keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO{sub 3} or NaNO{sub 2} in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Crystal Structure of Na3MoCl6

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Martin Beran

2011-07-01

Full Text Available The ternary chloride Na3MoCl6 is obtained as red crystals from a disproportionation reaction of molybdenum dichloride, {Mo6}Cl12, in an acidic NaCl/AlCl3 melt at 350 °C. The crystal structure (trigonal, P-31c, a = 687.1(1, c = 1225.3(2 pm, Z = 2, V = 501,0(1 106 pm3 is that of Na3CrCl6: within a hexagonal closest-packing of chloride ions two thirds of the octahedral voids are filled between the AB double layers with Na+/Mo3+, and between the BA layers with Na+.

Diffusion of calcium in pure and doped NaCl; Diffusion du calcium dans NaCl pur et dope

Energy Technology Data Exchange (ETDEWEB)

Slifkin, L; Brebec, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

We have determined, by diffusion experiments of Ca in pure and doped NaCl, the activation energy for the calcium jumps and the binding energy between calcium ion and vacancy. (authors) [French] Nous avons determine, par des mesures de diffusion du Ca dans NaCl pur et NaCl dope avec CaCl{sub 2}, l'energie d'activation relative aux sauts du calcium et l'energie de liaison lacune-calcium. (auteurs)

Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim

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Zbigniew Greń

2017-12-01

Full Text Available The image of the atheist and his place on the confessional map of the world in Cieszyn Silesia The aim of this article is to create an image of the atheist based on historical and contemporary sources. The history of the concept of the atheist is described on the basis of the regional press, the contemporary picture of the concept – on the basis of the results of a questionnaire and discussions on religious topics on regional websites. The analysis showed that the concept of the atheist is treated as a term equivalent to the terms of members of different churches. The research shows not only the image of the atheist, but also its place in the system of perception of religious differences.   Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim Celem niniejszego artykułu jest stworzenie obrazu ateisty na podstawie źródeł historycznych i współczesnych. Historia pojęcia ateisty została opisana na podstawie prasy regionalnej, współczesny obraz – na podstawie wyników ankiet i dyskusji na tematy religijne na regionalnych stronach internetowych. Analiza wykazała, że pojęcie ateisty jest traktowane jako pojęcie równorzędne z określeniami członków różnych Kościołów. W wyniku badań przedstawiono nie tylko wizerunek ateisty, lecz także jego miejsce w systemie postrzegania różnic wyznaniowych.

Mabadiliko Ya Kifonolojia Na Kimofolojia Wakati Wa Utohozi Wa ...

African Journals Online (AJOL)

Mwingiliano wa lugha ya Kiswahili na Kiarabu una historia ndefu kidogo. Inasemekana Waarabu walianza muwasala na 'Waswahili' tangu karne ya kwanza (BK) (Polome 1967:9). Kutokana na muwasala huo wa muda mrefu, lugha hizi mbili (Kiarabu na Kiswahili) zimeathiriana sana. Lakini kuna maoni kwamba Kiarabu ...

Aqueous partial molar heat capacities and volumes for NaReO4 and NaTcO4

International Nuclear Information System (INIS)

Lemire, R.J.; Saluja, P.P.S.; Campbell, A.B.

1989-01-01

As part of the Canadian Nuclear Fuel Waste Management Program, data are required to model the equilibrium thermodynamic behavior of key radionuclides at temperatures above 25 degree C. A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species. Measurements for solutions of aqueous NaReO 4 (a common analogue for NaTcO 4 ) were made at seven temperatures (15 to 100 degree C) over the concentration range 0.05 to 0.2 mol·kg -1 . Subsequently, measurements were made for NaTcO 4 solutions under similar conditions. The heat capacity and density data are analyzed using Pitzer's ion-interaction model, and values of the NaReO 4 partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO 4 data is good below 75 degree C, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. The uncertainties introduced by using thermodynamic data for ReO 4 - , in the absence of data for TcO 4 - , are discussed

Effects of dietary Na+ deprivation on epithelial Na+ channel (ENaC, BDNF, and TrkB mRNA expression in the rat tongue

Directory of Open Access Journals (Sweden)

Stähler Frauke

2009-03-01

Full Text Available Abstract Background In rodents, dietary Na+ deprivation reduces gustatory responses of primary taste fibers and central taste neurons to lingual Na+ stimulation. However, in the rat taste bud cells Na+ deprivation increases the number of amiloride sensitive epithelial Na+ channels (ENaC, which are considered as the "receptor" of the Na+ component of salt taste. To explore the mechanisms, the expression of the three ENaC subunits (α, β and γ in taste buds were observed from rats fed with diets containing either 0.03% (Na+ deprivation or 1% (control NaCl for 15 days, by using in situ hybridization and real-time quantitative RT-PCR (qRT-PCR. Since BDNF/TrkB signaling is involved in the neural innervation of taste buds, the effects of Na+ deprivation on BDNF and its receptor TrkB expression in the rat taste buds were also examined. Results In situ hybridization analysis showed that all three ENaC subunit mRNAs were found in the rat fungiform taste buds and lingual epithelia, but in the vallate and foliate taste buds, only α ENaC mRNA was easily detected, while β and γ ENaC mRNAs were much less than those in the fungiform taste buds. Between control and low Na+ fed animals, the numbers of taste bud cells expressing α, β and γ ENaC subunits were not significantly different in the fungiform, vallate and foliate taste buds, respectively. Similarly, qRT-PCR also indicated that Na+ deprivation had no effect on any ENaC subunit expression in the three types of taste buds. However, Na+ deprivation reduced BDNF mRNA expression by 50% in the fungiform taste buds, but not in the vallate and foliate taste buds. The expression of TrkB was not different between control and Na+ deprived rats, irrespective of the taste papillae type. Conclusion The findings demonstrate that dietary Na+ deprivation does not change ENaC mRNA expression in rat taste buds, but reduces BDNF mRNA expression in the fungiform taste buds. Given the roles of BDNF in survival of

Hydrogen production by sodium borohydride in NaOH aqueous solution

Science.gov (United States)

Wang, Q.; Zhang, L. F.; Zhao, Z. G.

2018-01-01

The kinetics of hydrolysis reaction of NaBH4 in NaOH aqueous solution is studied. The influence of pH of the NaOH aqueous solution on the rate of hydrogen production and the hydrogen production efficiency are studied for the hydrolysis reaction of NaBH4. The results show that the activation energy of hydrolysis reaction of NaBH4 increased with the increase of the initial pH of NaOH aqueous solution.With the increasing of the initial pH of NaOH aqueous solution, the rate of hydrogen production and hydrogen production efficiency of NaBH4 hydrolysis decrease.

Altered Regulation of type 3 Na+/H+ exchanger, type 1 Na+/HCO3- cotransporter, and Na+,K+-ATPase in the Kidney of Rats with Experimental Rhabdomyolysis

Science.gov (United States)

Ma, Seong Kwon; Bae, Eun Hui; Lee, JongUn; Kim, Sun Young; Kim, Sung Zoo; Choi, Ki Chul

2007-01-01

Metabolic acidosis was shown to correlate with deterioration of renal function in patients with rhabdomyolysis. The present study was aimed to investigate whether the changes of type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), and Na+,K+-ATPase α1 subunit may play a role in the pathogenesis of metabolic acidosis in glycerol-induced experimental rhabdomyolysis. Male Sprague-Dawley rats were deprived of fluid intake for 24 hours, and then were injected with 50% glycerol in normal saline (10 mL/kg, intramuscularly). At 24 hours after the glycerol injection, rats were sacrificed by decapitation. Control rats were injected with normal saline. The protein expression of NHE3, NBC1 and Na+,K+-ATPase α1 subunit was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Following the treatment of glycerol, creatinine clearance was significantly decreased, and high anion gap metabolic acidosis developed. In the experimental group, the expression of Na+,K+-ATPase α1 subunit was significantly decreased in the cortex of the kidney. On the contrary, the expression of NHE3 and NBC1 was significantly increased. Immunohistochemical analyses confirmed the immunoblotting data. In conclusion, the coordinate up-regulation of NHE3 and NBC1 may play an adaptive role against the metabolic acidosis in glycerol-induced rhabdomyolysis. PMID:24459502

K⁺ congeners that do not compromise Na⁺ activation of the Na⁺,K⁺-ATPase

DEFF Research Database (Denmark)

Mahmmoud, Yasser A; Kopec, Wojciech; Khandelia, Himanshu

2015-01-01

The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation...

Kupokelewa Zaidi Kwa Simu Ya Mkononi Kuliko Kompyuta Na ...

African Journals Online (AJOL)

Mtandao wa tovuti ni nyenzo ya msingi katika maendeleo ya uwanja wa mawasiliano unaounganisha watu na jamii mbalimbali katika ulimwengu wa leo unaotandawaa. Katika “ulimwengu wa kwanza na wa pili”, yaani mabara ya Amerika, Uropa na Asia, maendeleo na mapinduzi makubwa katika uwanja wa teknolojia ya ...

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie; Schwingenschlö gl, Udo

2016-01-01

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received

Coulomb excitation of radioactive 20, 21Na

Science.gov (United States)

Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

2009-12-01

The low-energy structures of the radioactive nuclei 20, 21Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ˜ 5×106 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 natTi target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for γ -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21Na , Coulomb excitation from the 3/2+ ground state to the first excited 5/2+ state was observed, while for 20Na , Coulomb excitation was observed from the 2+ ground state to the first excited 3+ and 4+ states. For both beams, B ( λ L) values were determined using the 2+ rightarrow 0+ de-excitation in 48Ti as a reference. The resulting B( E2) ↓ value for 21Na is 137±9 e^2fm^4, while the resulting B( λ L) ↓ values for 20Na are 55±6 e^2fm^4 for the 3+ rightarrow 2+ , 35.7±5.7 e^2 fm^4 for the 4+ rightarrow 2+ , and 0.154±0.030 μ_ N^2 for the 4+ rightarrow 3+ transitions. This analysis significantly improves the measurement of the 21Na B( E2) value, and provides the first experimental determination of B( λ L) values for the proton dripline nucleus 20Na .-1

Detailed investigation of Na2.24FePO4CO3 as a cathode material for Na-ion batteries

Science.gov (United States)

Huang, Weifeng; Zhou, Jing; Li, Biao; Ma, Jin; Tao, Shi; Xia, Dingguo; Chu, Wangsheng; Wu, Ziyu

2014-01-01

Na-ion batteries are gaining an increased recognition as the next generation low cost energy storage devices. Here, we present a characterization of Na3FePO4CO3 nanoplates as a novel cathode material for sodium ion batteries. First-principles calculations reveal that there are two paths for Na ion migration along b and c axis. In-situ and ex-situ Fe K-edge X-ray absorption near edge structure (XANES) point out that in Na3FePO4CO3 both Fe2+/Fe3+ and Fe3+/Fe4+ redox couples are electrochemically active, suggesting also the existence of a two-electron intercalation reaction. Ex-situ X-ray powder diffraction data demonstrates that the crystalline structure of Na3FePO4CO3 remains stable during the charging/discharging process within the range 2.0–4.55 V. PMID:24595232

Artesanato na terceira idade: um estudo na cidade de Sinop no ano de 2011

Directory of Open Access Journals (Sweden)

Rosane Marlene Weber

2015-04-01

Full Text Available Essa pesquisa tem como objetivo mostrar a importância do artesanato na Terceira Idade como atividade educacional e de autonomia para os idosos. Por existir uma preocupação com a qualidade de vida da Terceira Idade e sua autonomia, nesta fase que muitos acabam ficando dependentes dos membros da família, espera-se encontrar através da arte uma motivação e uma forma de demonstrar a autoria por meio do fazer, criar e recriar com o artesanato. Aprender e ensinar são um processo contínuo na vida do ser humano, independente da idade, para Paulo Freire precisamos ter consciência de que somos inacabados, e sendo conscientes de nossa inconclusão, devemos viver num permanente movimento de busca. Essa é uma das causas pelas quais será pesquisada a prática formativa/educacional por meio do artesanato na Terceira Idade. Os motivos que levaram a escolha desta pesquisa com o artesanato na Terceira Idade é o fato de ter vivido uma experiência de trabalho na ala geriátrica de um hospital. Já o artesanato é a arte que fascina, e acreditamos que sempre há tempo para recomeçar, para descobrir algo que possa trazer qualidade para nossa vida. Devido ao crescimento cada vez maior da expectativa de vida em nosso país, cria-se uma preocupação com a qualidade de vida das pessoas da Terceira Idade. Em relação aos aspectos educacionais e culturais, esta pesquisa deseja compreender como o artesanato pode trazer motivação para as pessoas da Terceira Idade como forma de autoria e autonomia, nesta fase da vida, na cidade de Sinop, e quais os motivos que os levam a realizar esse tipo de atividade. Para investigação teórica desta pesquisa do Artesanato na Terceira Idade: um estudo na cidade de Sinop em 2011 usaremos bibliografia de vários autores, mas em especial os que dedicam seus estudos a esta faixa etária, como a coleção de Vivaidade, que tem como organizadora principal Anita Liberalesso Neri. Os autores desta coleção nos trazem a reflex

Biphasic voltage-dependent inactivation of human NaV 1.3, 1.6 and 1.7 Na+ channels expressed in rodent insulin-secreting cells.

Science.gov (United States)

Godazgar, Mahdieh; Zhang, Quan; Chibalina, Margarita V; Rorsman, Patrik

2018-05-01

Na + current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na + (Na V ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single Na V subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that Na V channels adopt different inactivation behaviours depending on the local membrane environment. Pancreatic β-cells are equipped with voltage-gated Na + channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na + current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na + channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different Na V α-subunits. We tested this possibility by expression of TTX-resistant variants of the Na V subunits found in β-cells (Na V 1.3, Na V 1.6 and Na V 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all Na V subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. Na V 1.7 inactivated at 15--20 mV more negative membrane potentials than Na V 1.3 and Na V 1.6 in Ins1 cells but this small difference is insufficient to solely

A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

Science.gov (United States)

Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

2017-08-02

In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

Effect of chloride substitution on the order–disorder transition in NaBH{sub 4} and Na{sup 11}BD{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Olsen, Jørn Eirik [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Karen, Pavel [University of Oslo, Department of Chemistry, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway); Sørby, Magnus H. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, Bjørn C., E-mail: bjorn.hauback@ife.no [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway)

2014-02-25

Graphical abstract: Interactions that order the BD{sub 4}{sup -} tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH{sub 4}){sub 1−x}Cl{sub x} and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na{sup 11}BD{sub 4} at room temperature and 8 K and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na{sup 11}BD{sub 4} (NaBH{sub 4}) and its solid solutions with NaCl, Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x}, is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na{sup 11}BD{sub 4}, ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na{sup 11}BD{sub 4}) at 8 K.

TweetNaCl : a crypto library in 100 tweets

NARCIS (Netherlands)

Bernstein, D.J.; van Gastel, B.; Janssen, W.; Lange, T.; Schwabe, P.; Smetsers, S.; Aranha, D.F.; Menezes, A.

2015-01-01

This paper introduces TweetNaCl, a compact reimplementation of the NaCl library, including all 25 of the NaCl functions used by applications. TweetNaCl is published on Twitter and fits into just 100 tweets; the tweets are available from anywhere, any time, in an unsuspicious way. Distribution via

Na7 [Fe2S6 ] , Na2 [FeS2 ] and Na2 [FeSe2 ] : New 'reduced' sodium chalcogenido ferrates

Science.gov (United States)

Stüble, Pirmin; Peschke, Simon; Johrendt, Dirk; Röhr, Caroline

2018-02-01

Three new 'reduced' FeII containing sodium chalcogenido ferrates were obtained applying a reductive synthetic route. The mixed-valent sulfido ferrate Na7 [Fe2S6 ] , which forms bar-shaped crystals with metallic greenish luster, was synthesized in pure phase from natural pyrite and elemental sodium at a maximum temperature of 800 °C. Its centrosymmetric triclinic structure (SG P 1 bar , a = 764.15(2), b = 1153.70(2), c = 1272.58(3) pm, α = 62.3325 (7) , β = 72.8345 (8) , γ = 84.6394 (8) ° , Z = 3, R1 = 0.0185) exhibits two crystallographically different [Fe2S6 ] 7 - dimers of edge-sharing [FeS4 ] tetrahedra, with somewhat larger Fe-S distances than in the fully oxidized FeIII dimers of e.g. Na6 [Fe2III S6 ] . In contrast to the localized AFM ordered pure di-ferrates(III), the Curie-Weiss behavior of the magnetic susceptibility proves the rarely observed valence-delocalized S = 9/2 state of the mixed-valent FeIII /FeII dimer. The nearly spin-only value of the magnetic moment combined with the chemical bonding not generally differing from that in pure ferrates(II) and (III), provides a striking argument, that the reduction of the local Fe spin moments observed in all condensed sulfido ferrate moieties is connected with the AFM spin ordering. The two isotypic ferrates(II) Na2 [FeS2 ] and Na2 [FeSe2 ] with chain-like structural units (SG Ibam, a = 643.54(8)/ 660.81(1), b = 1140.2(2)/1190.30(2) c = 562.90(6)/585.59(1) pm, Z = 4, R1 = 0.0372/0.0466) crystallize in the K2 [ZnO2 ] -type structure. Although representing merely further members of the common series of chalcogenido metallates(II) Na2 [MIIQ2 ] , these two new phases, together with Na6 [FeS4 ] and Li2 [FeS2 ] , are the only examples of pure FeII alkali chalcogenido ferrates. The new compounds allow for a general comparison of di- and chain ferrates(II) and (III) and mixed-valent analogs concerning the electronic and magnetic properties (including Heisenberg super-exchange and double-exchange interactions

ZAZNAVA IN VPLIV BARV NA PRIMERU TISKANIH OGLASOV

OpenAIRE

Spes, Katja

2015-01-01

V diplomski nalogi smo s pomočjo literature opisali simboliko osnovnih barv, vpliv, ki ga imajo na ljudi, ter njihov pomen v oglasnih sporočilih. Omejili smo se na tiskane oglase (plakate, časopise, revije, neposredno pošto in embalažo) in opisali njihove prednosti in slabosti. Z anketnim vprašalnikom smo ugotavljali, na katere barve smo najbolj pozorni in katerim lastnostim se posamezne barve bolj približajo. Osredotočili smo se na sedem barv

Lipopolysaccharide hyperpolarizes guinea pig airway epithelium by increasing the activities of the epithelial Na(+) channel and the Na(+)-K(+) pump.

Science.gov (United States)

Dodrill, Michael W; Fedan, Jeffrey S

2010-10-01

Earlier, we found that systemic administration of lipopolysaccharide (LPS; 4 mg/kg) hyperpolarized the transepithelial potential difference (V(t)) of tracheal epithelium in the isolated, perfused trachea (IPT) of the guinea pig 18 h after injection. As well, LPS increased the hyperpolarization component of the response to basolateral methacholine, and potentiated the epithelium-derived relaxing factor-mediated relaxation responses to hyperosmolar solutions applied to the apical membrane. We hypothesized that LPS stimulates the transepithelial movement of Na(+) via the epithelial sodium channel (ENaC)/Na(+)-K(+) pump axis, leading to hyperpolarization of V(t). LPS increased the V(t)-depolarizing response to amiloride (10 μM), i.e., offset the effect of LPS, indicating that Na(+) transport activity was increased. The functional activity of ENaC was measured in the IPT after short-circuiting the Na(+)-K(+) pump with basolateral amphotericin B (7.5 μM). LPS had no effect on the hyperpolarization response to apical trypsin (100 U/ml) in the Ussing chamber, indicating that channel-activating proteases are not involved in the LPS-induced activation of ENaC. To assess Na(+)-K(+) pump activity in the IPT, ENaC was short-circuited with apical amphotericin B. The greater V(t) in the presence of amphotericin B in tracheas from LPS-treated animals compared with controls revealed that LPS increased Na(+)-K(+) pump activity. This finding was confirmed in the Ussing chamber by inhibiting the Na(+)-K(+) pump via extracellular K(+) removal, loading the epithelium with Na(+), and observing a greater hyperpolarization response to K(+) restoration. Together, the findings of this study reveal that LPS hyperpolarizes the airway epithelium by increasing the activities of ENaC and the Na(+)-K(+) pump.

Redetermination of Na(3)TaF(8).

Science.gov (United States)

Langer, Vratislav; Smrcok, Lubomír; Boca, Miroslav

2010-09-01

The crystal structure of trisodium octafluoridotantalate, Na(3)TaF(8), has been redetermined using diffractometer data collected at 153 K, resulting in more accurate bond distances and angles than obtained from a previous structure determination based on film data. The structure is built from layers running along [101], which are formed by distorted [TaF(8)] antiprisms and [NaF(6)] rectangular bipyramids sharing edges and corners. The individual layers are separated by eight-coordinated Na ions. Two atoms in the asymmetric unit are in special positions: the Ta atom is on a twofold axis in Wyckoff position 4e and one of the Na ions lies on an inversion centre in Wyckoff site 4d.

ser precoce na intervenção

OpenAIRE

Bernardo, Ana Carolina Couto

2013-01-01

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio da Intervenção Precoce na Infância Este estudo centra-se na implementação de uma Escola de Mães, programa de educação parental realizado em seis sessões na freguesia de Calhetas, ilha de S. Miguel, e na avaliação comparativa, anterior e posterior ao programa, das três mães participantes no que...

Na+/H+ exchange activity in the plasma membrane of Arabidopsis.

Science.gov (United States)

Qiu, Quan-Sheng; Barkla, Bronwyn J; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S

2003-06-01

In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt.

Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

International Nuclear Information System (INIS)

Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

2009-01-01

The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

Optimization and kinetics decomposition of monazite using NaOH

International Nuclear Information System (INIS)

MV Purwani; Suyanti; Deddy Husnurrofiq

2015-01-01

Decomposition of monazite with NaOH has been done. Decomposition performed at high temperature on furnace. The parameters studied were the comparison NaOH / monazite, temperature and time decomposition. From the research decomposition for 100 grams of monazite with NaOH, it can be concluded that the greater the ratio of NaOH / monazite, the greater the conversion. In the temperature influences decomposition 400 - 700°C, the greater the reaction rate constant with increasing temperature greater decomposition. Comparison NaOH / monazite optimum was 1.5 and the optimum time of 3 hours. Relations ratio NaOH / monazite with conversion (x) following the polynomial equation y = 0.1579x 2 – 0.2855x + 0.8301 (y = conversion and x = ratio of NaOH/monazite). Decomposition reaction of monazite with NaOH was second orde reaction, the relationship between temperature (T) with a reaction rate constant (k), k = 6.106.e - 1006.8 /T or ln k = - 1006.8/T + 6.106, frequency factor A = 448.541, activation energy E = 8.371 kJ/mol. (author)

The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample

Energy Technology Data Exchange (ETDEWEB)

Mody, D.; Li, C.Z.

1999-07-01

A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.

Avaliação do tratamento térmico na composição química e na qualidade da cajuína Evaluation of the thermal treatment on the chemical composition and quality of "cajuína" beverage

Directory of Open Access Journals (Sweden)

Ronaldo Ferreira do Nascimento

2003-08-01

Full Text Available Neste trabalho foi estudado o efeito do processo de tratamento térmico na qualidade e composição química da bebida cajuína quando submetida ao cozimento sob temperatura constante de 100ºC durante 1:00, 1:30, 2:00, 2:30, 3:00 e 4:00 horas. Alíquotas foram coletadas em cada tempo de aquecimento e analisadas por cromatografia líquida de alta eficiência (CLAE em relação aos ácidos (cítrico e ascórbico, aldeídos furânicos (5-hidroximetilfurfural e furfural e açúcares (frutose, glicose e frutose. Os resultados foram reprodutíveis e indicaram que as cajuínas comerciais do estado do Ceará apresentam uma grande diversidade quanto ao processo de cozimento e ao teor de vitamina C, causados principalmente por processos térmicos inadequados. O tempo mais adequado sugerido para o "cozimento" da cajuína está em torno de 2:00h. O trabalho também aponta a combinação das análises de 5-HMF, furfural, ácido ascórbico e teor de ácido ascórbico/ácido cítrico como uma metodologia alternativa para a avaliação da qualidade da cajuína.In this work the effect of the thermal process on the quality and chemical composition of the beverage cajuína was studied. Cajuína is basically clarified cashew juice. Samples of cajuína were submitted to thermal processes, of constant heating (100ºC for 1:00, 1:30, 2:00, 2:30, 3:00 and 4:00 hours. The samples were subsequently analyzed by HPLC for glucose, fructose, citric acid, ascorbic acid, hydroxymethylfurfural (5-HMF and furfural. The results showed that the commercial cajuína beverage of Ceará State presented a great diversity in process standardization and vitamin C content, caused by inadequate thermal processing. The process is more efficient with a time period of 2:00hs. The work also indicates a combination of the analyses of 5-HMF, furfural and ascorbic acid and the ratio ascorbic acid/citric acid, as an alternative methodology for the evaluation of cajuína quality.

Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density

DEFF Research Database (Denmark)

Yan, Wei; Huang, Shengli; Stenby, Erling Halfdan

2011-01-01

over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2–NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2–saturated NaCl brine density. A literature review of the available data was presented first...

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

International Nuclear Information System (INIS)

Wang, Yimin; Bowman, Joel M.; Kamarchik, Eugene

2016-01-01

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na + H 2 O, F − H 2 O, and Cl − H 2 O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H 2 O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na + and aVTZ basis for Cl − and F − ), over a large range of distances and H 2 O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Threshold oxygen levels in Na(I) for the formation of NaCrO 2(s) on 18-8 stainless steels from accurate thermodynamic measurements

Science.gov (United States)

Sreedharan, O. M.; Madan, B. S.; Gnanamoorthy, J. B.

1983-12-01

The compound NaCrO 2(s) is an important corrosion product in sodium-cooled LMFBRs. The standard Gibbs energy of formation of NaCrO 2(s) is required for the computation of threshold oxygen levels in Na(1) for the formation of NaCrO 2(s) on 18-8 stainless steels. For this purpose the emf of the galvanic cell: Pt, NaCrO 2, Cr 2O 3, Na 2CrO 4/15 YSZ/O 2 ( P O 2 = 0.21 atm, air), Pt was measured over 784-1012 K to be: (E±4.4)(mV) = 483.67-0.34155 T(K). From this, the standard Gibbs energy of formation of NaCrO 2(s) from the elements ( ΔG f,T0) and from the oxides ( ΔG f,OX,T0) was calculated to be: [ΔG f,T0(NaCrO 2, s)±1.86] (kJ/mol) =-869.98 + 0.18575 T(K) , [ΔG f,OX,T0(NaCr0 2, s)±4.8] (kJ/mol) = -104.25-0.00856 T(K) . The molar heat capacity, C P0, of NaCrO 2(s) was measured by DSC to be (350-600 K): C P0(NaCrO 2, s) (J/K mol) = 27.15 + 0.1247 T (K) , From these data, values of -99.3 kJ/mol and 91.6 J/K mol were computed for ΔH f,2980 and S 2980 of NaCrO 2(s). The internal consistency was checked with the use of enthalpy data on Na 2CrO 4(s). From the standard Gibbs energy of formation of NaCrO 2(s) the equation logC 0(wppm) = 3.9905-3147.6 T(K) was derived, where C 0 is the threshold oxygen level for the formation of NaCrO 2(s) on 18-8 stainless steels.

PRIMERJAVA GEODETSKIH METOD NA ZAHTEVNEM GRADBENEM OBJEKTU

OpenAIRE

Reberčnik, Matic

2017-01-01

V projektni nalogi smo v uvodnih poglavjih predstavili različne načine izvajanja geodetskih meritev, ki jih v gradbeništvu uporabljamo pri analizi pomikov in deformacij gradbenih konstrukcij ter terena, na katerem so le-te postavljene. V nadaljevanju opisujemo terestične in GNSS (globalni navigacijski satelitski sistem) metode, ki smo jih uporabljali pri izvajanju meritev na izbranem premostitvenem objektu avtocestnega odseka v Sloveniji (zaradi varovanja podatkov ga imenujemo Objekt 1). Pod...

Synthesis of Li(x)Na(2-x)Mn2S3 and LiNaMnS2 through redox-induced ion exchange reactions

International Nuclear Information System (INIS)

Luthy, Joshua A.; Goodman, Phillip L.; Martin, Benjamin R.

2009-01-01

Na 2 Mn 2 S 3 was oxidatively deintercalated using iodine in acetonitrile to yield Na 1.3 Mn 2 S 3 , with lattice constants nearly identical to that of the reactant. Lithium was then reductively intercalated into the oxidized product to yield Li 0.7 Na 1.3 Mn 2 S 3 . When heated, this metastable compound decomposed to form a new crystalline compound, LiNaMnS 2 , along with MnS and residual Na 2 Mn 2 S 3 . Single crystal X-ray diffraction structural analysis of LiNaMnS 2 revealed that this compound crystallizes in P-3m1 with cell parameters a=4.0479(6) A, c=6.7759(14) A, V=96.15(3) A 3 (Z=1, wR2=0.0367) in the NaLiCdS 2 structure-type. - Graphical abstract: Structure of LiNaMnS 2 . Li and Mn are statistically distributed in edge-shared tetrahedral environments linked into infinite planes. Sodium ions occupy interlayer sites

Número de amostras na análise geoestatística e na krigagem de mapas de atributos do solo

Directory of Open Access Journals (Sweden)

Zigomar Menezes de Souza

2014-02-01

Full Text Available O objetivo deste trabalho foi analisar diferentes intensidades de amostragem do solo com relação à precisão na análise geoestatística e interpolação de mapas, para fins de agricultura de precisão em área de cana-de-açúcar. O solo foi coletado em duas grades regulares na profundidade de 0,00-0,20m para análise granulométrica (área 1 e da fertilidade do solo (área 2. Foram comparadas intensidades de amostragem do solo: 208, 105, 58 e 24 pontos na área 1 e 206, 102 e 53 pontos na área 2. Os dados foram submetidos à análise descritiva e geoestatística. Os variogramas construídos com 105 pontos não diferem dos variogramas com 208 pontos, fato que não ocorre para 58 e 24 pontos. O aumento do intervalo de amostragem e a redução do número de pontos promovem o maior erro na estimativa por krigagem. As amostragens com mais de 100 pontos por área não resultaram em melhorias significativas no erro da estimativa por krigagem, nem diferiram na quantidade de insumos aplicados em campo.

Corpo-escrita na esquizofrenia

OpenAIRE

Bialer, Marina

2014-01-01

Este artigo aborda a importância do trabalho de escrita na esquizofrenia. Toma-se como ponto de partida a formulação lacaniana sobre o esquizofrênico como aquele que não tem as funções dos órgãos do seu corpo dadas pelos discursos estabelecidos. A hipótese de que o trabalho sobre a letra pode permitir o tratamento do gozo debordante na esquizofrenia é analisada pelo estudo da obra do escritor esquizofrênico Robert Walser, a qual evidencia a viabilidade da construção de um corpo pela escrita n...

Chemisorption of Na on the Ti Nanoparticle surface and its effects on the Na-H{sub 2}O reaction reactivity

Energy Technology Data Exchange (ETDEWEB)

Kim, Soo Jae; Park, Gunyeop; Baek, Jehyun; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-10-15

This accident showed that elimination of SWR risk should be one of the most significant design criteria for the development of safe SFRs. Design solutions to ensure isolation of the Na from the water have been proposed; these include double-walled structures in the steam generator and at coolant boundaries and guard vessels or guard piping lines filled with inert gas. However, those methods cannot be ultimate solutions because the system still has a possibility of failure. An alternative approach to reduce the severity of the SWR is to reduce the reactivity of Na. Recently, this goal has been achieved by suspending a small amount of Ti nanoparticles (NPs) in liquid Na. Adding 2 at% of 10-nm Ti NPs in liquid Na reduced the heat of the reaction up to 80% and H{sub 2} production rate by 10%. The number of adsorbed Na atoms onto Ti NPs with respect to the various temperature and pressure was calculated by using ab-initio and thermodynamics. Furthermore, the model which relates the Na chemisorption and SWR reactivity was proposed. The repression of SWR by Ti NPs was expected to be caused by strong chemical interaction between Ti NP surface and Na atoms; ab initio calculation using density functional theory and atomistic thermodynamic approach were conducted to test this hypothesis. Adsorption of 0.25ML Na at hcp hollow sites was the most favorable adsorption surface state and strong chemical adsorption was confirmed by the adsorption energy of -1.65 eV. A covalent-like metallic bond was confirmed between adsorbed Na and Ti atoms on the Ti(0001) surface; this bond affects the hydration energy of Na atoms and the activation barrier of the SWR. Using adsorption energy from the ab-initio calculation and atomistic thermodynamics, the thermodynamically most stable adsorption state at (T,P) was determined Na chemisorption effect on the SWR reactivity regression rate is modeled. The model predict χ variation with respect to time well especially dramatic reduction of χ; the �

O apelo ecológico na propaganda como fator de influência na atitude de compra do consumidor: um estudo experimental

OpenAIRE

Santos, João Maurício

2010-01-01

Este estudo examinou o apelo ecológico utilizado na propaganda como influenciador na atitude de compra do consumidor, tendo em vista que nas duas últimas décadas houve um crescimento nos anúncios que utilizam este tipo de apelo, demonstrando que, pelo surgimento de um novo nicho de mercado, empresas têm se valido do marketing verde e da influência normativa na sua estratégia de marketing. Buscou-se investigar se efetivamente o uso do apelo ecológico na propaganda influencia pos...

Dejavniki psihološkega nasilja na delovnem mestu

OpenAIRE

Ilc, Teja

2011-01-01

Raziskave na področju delovnih razmer kažejo, da je danes pereč problem ravno psihološko nasilje na delovnem mestu. Posebna oblika psihološkega nasilja na delovnem mestu je mobing, s katerim se v praksi srečujemo vsak dan, vendar se ga pogosto ne zavedamo. Namen magistrske naloge je pojasniti pojem in pomen mobinga v delovnih organizacijah, poiskati možne vzroke in posledice, ki vplivajo na ta pojav, ter predlagati rešitve. Poznavanje mehanizmov, ki povzročajo mobing, njegovih vzrokov in...

Anisotropy and polarization in charge changing collisions of C4+ with Na(3s) and laser aligned Na(3p)

NARCIS (Netherlands)

Hoekstra, R; Morgenstern, R; Olson, RE

1996-01-01

Absolute cross sections for C3+(6-->5) emission at 465.7 nm after collisions of C4+ ions with ground state Na(3s) and laser excited aligned Na(Sp) atoms are measured over the collision energy range of 3-7 keV amu(-1). For Na(3s) polarizations are observed by measuring the linear polarization of the

Efeito da dexametasona e do cetoprofeno na osteogênese e na resistência óssea em ratos

Directory of Open Access Journals (Sweden)

Patrícia Costa dos Santos da Silva

2012-04-01

Full Text Available O presente estudo teve como objetivo avaliar o efeito do cetoprofeno e da dexametasona na osteogênese ao redor de implante de hidroxiapatita densa (HAD na tíbia, no osso parietal, e na resistência óssea. Utilizaram-se 15 ratos Wistar, pesando 250±30 g, com 50 dias de idade. Após a anestesia com quetamina/xilazina IM, produziuse no osso parietal e na epífise proximal da tíbia uma cavidade de 3 mm, sendo implantada a HAD. Após a cirurgia os animais foram divididos em três grupos (n=5: controle (CT, anti-inflamatório não esteroidal (AINES e anti-inflamatório esteroidal (AIES. O grupo AINES foi submetido ao tratamento com cetoprofeno na dose de 12 mg/Kg/dia, o AIES recebeu doses de 0,10 mg/kg/dia de dexametasona o grupo CT recebeu solução fisiológica 0,9% (SF por via subcutânea durante 30 dias. Todos os grupos receberam a mesma dieta sólida e água ad libitum. Após 30 dias de experimento os animais sofreram eutanásia, os fêmures coletados, para teste mecânico, e os locais do implante das tíbias e o osso parietal, para análise histomorfométrica. Os grupos AINES e AIES apresentaram menor volume de osso neoformado na falha óssea e ao redor do implante de HAD , como também, menor força máxima para a ruptura completa dos fêmures, quando comparados com o grupo CT. O uso do cetoprofeno e a dexametasona interferiram na osteogênese ao redor do implante de HAD e no osso parietal, diminuindo a resistência óssea principalmente pela inibição da COX2 e diminuição das prostaglandinas, comprometendo a estabilidade e manutenção do implante.

Nalaz tombusvirusa na vrsti Erigeron canadensis L.

OpenAIRE

Jeknić, Zoran; Erić, Živojin; Grbelja, Julijana

1988-01-01

Iz listova zaraženih primjeraka korovne biljke Erigeron canadensis L. koji su rasli na nekoliko lokaliteta u Sarajevu izoliran je virus iz skupine tombusvirusi. Identifikacija virusa izvršena je na osnovi reakcije pokusnih biljaka, analize ultratankih presjeka kroz zaraženo tkivo, morfologije i veličine virusnih čestica, te na osnovi seroloških reakcija metodom dvostruke imunodifuzije u agarskom gelu i čvrsto fazne imunoelektronske mikroskopije (SPIEM). U serološkim pokusima upotrijebljen je ...

Transcriptional regulators of Na, K-ATPase subunits

OpenAIRE

Zhiqin eLi; Sigrid A Langhans

2015-01-01

The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during developme...

NaIrO3-A pentavalent post-perovskite

International Nuclear Information System (INIS)

Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

2011-01-01

Sodium iridium (V) oxide, NaIrO 3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO 3 , the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO 3 . Among the oxide post-perovskites, NaIrO 3 is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO 6 octahedra separated by layers of NaO 8 bicapped trigonal prisms. NaIrO 3 shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides. -- Graphical abstract: Sodium iridium(V) oxide, NaIrO 3 , synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO 3 post-perovskite. Research highlights: → NaIrO 3 post-perovskite stabilized by pressure. → First example of a pentavalent oxide post-perovskite. → Non-metallic and non-magnetic behavior of NaIrO 3 .

LiVO/sub 3/-Li/sub 2/Mo(W)O/sub 4/ and NaVO/sub 3/-Na/sub 2/Cr(Mo)O/sub 4/ systems

Energy Technology Data Exchange (ETDEWEB)

Belyaev, I N; Lupeiko, T G; Vyalikova, V I [Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)

1975-09-01

The systems LiVO/sub 3/-Li/sub 2/MoO/sub 4/, LiVO/sub 3/-Li/sub 2/WO/sub 4/, NaNO/sub 3/-Na/sub 2/CrO/sub 4/, NaNO/sub 3/-Na/sub 2/MoO/sub 4/ were studied with thermographic and partially visual polythermal methods of physical and chemical analyses. Except NaVO/sub 3/-Na/sub 2/MoO/sub 4/ all investigated systems are eutectic ones with limited solid solutions on the basis of some component; the eutectics melt at 542, 544, 550/sup 0/C and contain 25, 20 and 26% of Li/sub 2/MoO/sub 4/, Li/sub 2/WO/sub 4/ and Na/sub 2/CrO/sub 4/ respectively. The system NaNO/sub 3/-Na/sub 2/MoO/sub 4/ contains compound 18 NaVO/sub 3/.11Na/sub 2/MoO/sub 4/ congruently melting at 570/sup 0/C. Two eutectics of the system have melting points at 542 and 548/sup 0/C and contain 47 and 67% of Na/sub 2/MoO/sub 4/.

DRUŽBENA OMREŽJA NA INTERNETU

OpenAIRE

Ploj, Alen

2013-01-01

Družbena omrežja na spletu so zadnje čase zelo popularen način posredne komunikacije in predstavljajo naš vsakdan. Uporaba je enostavna in hitra, učinkovitost pa neverjetna. Zaradi priljubljenosti družbenih omrežij se njihove uporabe poslužujejo tudi različne organizacije, ki z njihovo pomočjo širijo obseg svojega delovanja ter obveščanja uporabnikov o svojih izdelkih/storitvah (marketing). Kot vsako donosno tržišče je tudi internetno tržišče nasičeno z družbenimi omrežji, ki ponujajo najr...

O Platonismo de Russell na metafísica e na matemática

Directory of Open Access Journals (Sweden)

Guido Imaguire

2005-06-01

Full Text Available Neste artigo, analiso o surgimento e a superação do Platonismo em B. Russell, tanto na sua filosofia da matemática como na sua metafísica. Começo por explicitar os argumentos que levaram Russell a aderir ao chamado "Platonismo Proposicional" - posição que será tecnicamente relevante na definição de números. Na seção seguinte, discutirei até que ponto a teoria das descrições definidas determina, necessariamente, uma adesão ao nominalismo, e as dificuldades que surgem para o logicismo conseqüentes do abandono do platonismo. Finalmente, mostrarei como a posição madura de Russell caracteriza-se mais como um reducionismo do que propriamente como um nominalismo, e como este é fundado no princípio do mínimo vocabulário.In this paper, I analyze the emergence and the overcoming of Platonism both in Russell's philosophy of mathematics and his metaphysics. I begin by examining the arguments which led Russell to endorse a position that I term "Propositional Platonism" - this position proves to be relevant for Russell's definition of numbers. In the following section, I address the question of the extent to which Russell's theory of descriptions implies the acceptance of nominalism. Moreover, I examine the difficulties which arise for logicism, if it no longer goes hand in hand with platonism. Finally, I argue argue that Russell's mature position is to be characterized as a form of reductionism rather than as a variant of nominalism

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

Energy Technology Data Exchange (ETDEWEB)

Wang, Yimin, E-mail: yimin.wang@emory.edu; Bowman, Joel M., E-mail: jmbowma@emory.edu [Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States); Kamarchik, Eugene, E-mail: eugene.kamarchik@gmail.com [Quantum Pomegranate, LLC, 2604 Kings Lake Court NE, Atlanta, Georgia 30345 (United States)

2016-03-21

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na{sup +}H{sub 2}O, F{sup −}H{sub 2}O, and Cl{sup −}H{sub 2}O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H{sub 2}O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na{sup +} and aVTZ basis for Cl{sup −} and F{sup −}), over a large range of distances and H{sub 2}O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Recovery of the heavy elements by NaY AND NaZSM-5 sorbant materials

International Nuclear Information System (INIS)

Nibou, D.; Lebail, S.

1997-04-01

Porous sorbants as zeolites have a several applications in differents fiels: industrial gas purification, catalysis, transformation hydrocarbures prosesses and exchange ions. The hiogh capacity to exchange their cations with those of aqueous solutions was known (1). Since the accession of synthetic zeolites, these silicates have invaded the market and the firstindustrial applications were in exchange field. Studies at Battelle Northwest in Rchland, Washington have shown that zeolites may be used in treatment of radioactive wastes (2). The used method for storing the isotopes is based on selective removal by ion exchange. Clinoptilolite, zeolite (modernite), NaA, and AW-500 have been used. In this context, the present work deals with the recovery of heavy metals like lead and uranium using some microporous materials. The obtained results show that NaY faujasite and NaZSM-5 of the FAU- and MFI-type structure respectively are very effective in removing these elements from waste water

Hali ya taaluma ya ukalimani Tanzania: jana, leo na kesho ...

African Journals Online (AJOL)

Umuhimu wa ukalimani katika mawasiliano umeongezeka kutokana na utandawazi. Utandawazi umerahisisha kukutanika na kuwasiliana kwa watu wazungumzao lugha tofauti kupitia wakalimani. Kutokana na ongezeko hilo la umuhimu wa ukalimani, kumekuwa na jitihada mbalimbali katika nchi mbalimbali kuhakikisha ...

Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

Science.gov (United States)

Dempsey, Paula J.; Zakrajsek, James J.

2001-01-01

NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

Secretory NaCl and volume flow in renal tubules.

Science.gov (United States)

Beyenbach, K W

1986-05-01

This review attempts to give a retrospective survey of the available evidence concerning the secretion of NaCl and fluid in renal tubules of the vertebrate kidney. In the absence of glomerular filtration, epithelial secretory mechanisms, which to this date have not been elucidated, are responsible for the renal excretion of NaCl and water in aglomerular fish. However, proximal tubules isolated from glomerular fish kidneys of the flounder, killifish, and the shark also have the capacity to secrete NaCl and fluid. In shark proximal tubules, fluid secretion appears to be driven via secondary active transport of Cl. In another marine vertebrate, the sea snake, secretion of Na (presumably NaCl) and fluid is observed in freshwater-adapted and water-loaded animals. Proximal tubules of mammals can be made to secrete NaCl in vitro together with secretion of aryl acids. An epithelial cell line derived from dog kidney exhibits secondary active secretion of Cl when stimulated with catecholamines. Tubular secretion of NaCl and fluid may serve a variety of renal functions, all of which are considered here. The occurrence of NaCl and fluid secretion in glomerular proximal tubules of teleosts, elasmobranchs, and reptiles and in mammalian renal tissue cultures suggests that the genetic potential for NaCl secretion is present in every vertebrate kidney.

Mechanochemical transformations in Li(Na)AlH{sub 4}-Li(Na)NH{sub 2} systems

Energy Technology Data Exchange (ETDEWEB)

Dolotko, Oleksandr [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Zhang Haiqiao [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Ugurlu, Ozan [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Wiench, Jerzy W. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Pruski, Marek [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Scott Chumbley, L. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Pecharsky, Vitalij [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States) and Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States)]. E-mail: vitkp@ameslab.gov

2007-05-15

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH{sub 4} and LiNH{sub 2} taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH{sub 4}-NaNH{sub 2} system after 60 min ball milling; and 5.2 wt.% H{sub 2} is released when LiAlH{sub 4} and NaNH{sub 2} or NaAlH{sub 4} and LiNH{sub 2} are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH{sub 4}(s) + MNH{sub 2}(s) {sup {yields}} 2MH(s) + AlN(s) + 2H{sub 2}(g) was identified based on detailed spectroscopic analysis of the intermediate (M{sub 3}AlH{sub 6}) and final products of the ball milling process.

Ética na pesquisa em Administração

OpenAIRE

Leite, Ana Patrícia Rodrigues

2012-01-01

A ética na pesquisa científica é um tema abordado e muito discutido em diversas áreas do conhecimento ligadas à saúde. Na área da Administração, são raros os estudos que abordam o tema da ética na pesquisa. O presente estudo buscou preencher esta lacuna na produção do conhecimento sobre o tema, investigando como os princípios éticos encontrados na literatura e nos códigos de conduta são percebidos e considerados nas atividades de pesquisa em Administração, desenvolvidas por pes...

NA48 experiment : view along the NA48 beamline with the detector in the distance.

CERN Multimedia

Hans Taureg

1996-01-01

Photo 02: Side view of the NA48 experiment showing the LKR calorimeter cryostat No one is sure why the Universe wound up the way it has: all matter and no antimatter. According to prevailing theories, the early universe had equal amounts of matter and antimatter. To see what might be missing from the theories, physicists search for the rare cases in which matter and antimatter behave differently. One such imbalance, called direct CP violation, showed up in the NA 31 experiment at CERN. The results from this experiment, first presented in 1993, showed that when K mesons and their antimatter cousins decay, they show a slight preference for matter over antimatter. Later experiments with neutral K mesons, including NA48 at CERN and KTeV at Fermilab in the United States, showed direct CP violation is real.

Microhardness studies on as-grown faces of NaClO3 and NaBrO3 ...

Indian Academy of Sciences (India)

Unknown

studies are made on as-grown faces of these crystals at various loads. Typical cracks are ... crystals is around 1⋅6 suggesting that these are moderately harder samples. ... the values of elastic constants (C44) and are found to be close to the experimental results. ..... the structure of NaClO3 and NaBrO3 is not as simple as.

Thermodiffusive behaviour of NaCl and KCl aqueous solutions a model for the Na-K pump

International Nuclear Information System (INIS)

Gaeta, F.S.; Mita, D.G.; Perna, G.; Scala, G.

1975-01-01

In NaCl and KCl aqueous nonisothermal solutions K + inverts its sense of migration within the physiological concentration range; Na + behaves similarly at much lower concentrations. These findings are discussed in relation to solute induced modifications of water structure and of their influence on thermal diffusion. A possible evolutionary model of a thermodiffusive mechanism for the sodium potassium pump is also suggested

ANALIZA UPORABNIŠKIH VMESNIKOV NA MOBILNIH NAPRAVAH

OpenAIRE

Bohak, Gregor

2012-01-01

V diplomskem delu smo predstavili pravila in smernice oblikovanja uporabniških vmesnikov na mobilnih napravah. Omejili smo se na platforme Google Android, Nokia Symbian, Nokia MeeGo, Apple iOS ter Microsoft Windows Phone 7. Za vsako izmed platform smo predstavili splošen model uporabniškega vmesnika, splošen model uporabniškega vmesnika aplikacije, navigacijske vzorce ter gradnike. Vse skupaj tudi smo obogatili z veliko grafičnega materiala. V drugem delu smo na podlagi pridobljenega znanja p...

Role of alkali carbonate and salt in topochemical synthesis of K1/2Na1/2NbO3 and NaNbO3 templates

Science.gov (United States)

Lee, Jae-Seok; Jeon, Jae-Ho; Choi, Si-Young

2013-11-01

Since the properties of lead-free piezoelectric materials have thus far failed to meet those of lead-based materials, either chemical doping or morphological texturing should be employed to improve the piezoelectric properties of lead-free piezoelectric ceramics. The goal of this study was to synthesize plate-like K1/2Na1/2NbO3 and NaNbO3 particles, which are the most favorable templates for morphological texturing of K1/2Na1/2NbO3 ceramics. To achieve this goal, Bi2.5Na3.5Nb5O18 precursors in a plate-like shape were first synthesized and subsequently converted into K1/2Na1/2NbO3 or NaNbO3 particles that retain the morphology of Bi2.5Na3.5Nb5O18. In this study, we found that sodium or potassium carbonate does not play a major role in converting the Bi2.5Na3.5Nb5O18 precursor to K1/2Na1/2NbO3 or NaNbO3, on the contrary to previous reports; however, the salt contributes to the conversion reaction. All synthesis processes have been performed via a molten salt method, and scanning electron microscopy, scanning probe microscopy, and inductively coupled plasma mass spectroscopy were used to characterize the synthesized K1/2Na1/2NbO3 or NaNbO3 templates.

Marketingový mix Restaurace Na chalupě

OpenAIRE

Kubíková, Martina

2013-01-01

Bakalářská práce se zaměřuje na rozbor marketingu a především marketingového mixu. Tedy na známé definice marketingu, marketingová prostředí a rozbor marketingového mixu, kde jsou zmapovány všechny jeho části (Produkt, Cena, Distribuce, Propagace, Fyzický důkaz, Lidé, Procesy). Z teoretických poznatků, které byly zjištěny v odborné literatuře, je vypracována praktická část. Zde je rozebrán marketingový mix Restaurace Na chalupě a zároveň tak i porovnání dvou provozovatelů, kteří se zde vystří...

Co-intercalation of Mg(2+) and Na(+) in Na(0.69)Fe2(CN)6 as a High-Voltage Cathode for Magnesium Batteries.