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Comparison of diode array and electrochemical detection in the C30 reverse phase HPLC analysis of algae carotenoids

GUARATINI, Thais; CARDOZO, Karina H. M.; PINTO, Ernani; COLEPICOLO, Pio
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.37%
Qualitative and quantitative determination of carotenoids pigments can provide valuable information about the organisms in which this important class of compounds is found. In the HPLC analysis of pigments, diode array (DAD), electrochemical (ED) and other kinds of detector may be used. The aim of this work is to develop an HPLC method using a C30 column to identify and quantify sixteen different pigments from algae. A further aim is to compare precision and accuracy obtained by DAD and ED. ED is normally more sensible than DAD. On the other hand, the highest precision and accuracy was obtained with DAD. In conclusion, the method was efficient for quantitative and qualitative analyses of pigments from cyanobacteria and different microalgae classes. Their pigment patterns for several organisms are also discussed.; A determinação qualitativa e quantitativa de carotenóides pode fornecer diferentes e importantes informações sobre os organismos que os contêm. Na análise de pigmentos por HPLC diversos detectores podem ser utilizados, como diode array (DAD) e eletroquímico (ED). O presente trabalho tem como objetivo desenvolver um método por HPLC utilizando uma coluna C30 para a identificação e quantificação de dezesseis pigmentos em diferentes classes de algas...

Functional Disability in Alzheimer Disease A Validation Study of the Brazilian Version of the Disability Assessment for Dementia (DAD-Br)

BAHIA, Valeria Santoro; CARTHERY-GOULART, Maria Teresa; NOVELLI, Marcia M.; KATO-NARITA, Eliane M.; AREZA-FEGYVERES, Renata; CARAMELLI, Paulo; NITRINI, Ricardo
Fonte: LIPPINCOTT WILLIAMS & WILKINS Publicador: LIPPINCOTT WILLIAMS & WILKINS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Background: The assessment of activities of daily living (ADL) is important both for the diagnosis and staging of dementia. The objective of this study was to verify the applicability and validity of the Brazilian version of the Disability Assessment for Dementia (DAD-Br). Methods: The DAD was applied to caregivers of 89 patients with probable Alzheimer disease (AD) and to 40 elderly individuals without cognitive impairment (controls). We assessed the construct validity of the scale and its diagnostic accuracy (sensitivity, specificity, and predictive value). In addition, intergroup and intragroup analyses were conducted to characterize patient performance on basic and instrumental ADL and to determine underlying deficits (initiation, planning, or effective execution). Results: AD patients and controls had mean ages of 76.4 +/- 6.9 years and 74.5 +/- 7.3 years (P = 0.08), respectively. Mean Mini-Mental State Examination scores were 17.4 +/- 5.0 and 26.1 +/- 5.1 (P < 0.001) and scores on the DAD were 68.4 +/- 19.0 and 99.8 +/- 0.9 (P < 0.001), for patients and controls, respectively. The DAD scale showed good internal consistency (Cronbach alpha = 0.77) and correlation with the Mini-Mental State Examination (r = 0.44; P < 0.001). The AD group did better on basic ADL than on instrumental ADL (P < 0.001). As expected...

Estudo analítico dos flavonoides dos frutos do maracujá (Passiflora edulis Sims f. flavicarpa Degener); Analytical studies of the flavonoids in passion fruit (Passiflora edulis Sims f. flavicarpa Degener)

Zeraik, Maria Luiza
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/04/2010 PT
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27.33%
Atualmente tem-se dado grande ênfase aos alimentos funcionais, pois atuam na prevenção e auxiliam na recuperação de várias doenças, como doenças inflamatórias crônicas, cardiovasculares e câncer, por apresentarem principalmente flavonoides, que previnem lesões oxidativas, propiciando benefícios à saúde. O Brasil é o maior produtor mundial do maracujá, e em vista disto é de suma importância o desenvolvimento de métodos analíticos e estudos de atividade antioxidante e anti-inflamatória do fruto de maracujá, visando sua possível utilização como alimento funcional e produção de possíveis fármacos. Passiflora edulis Sims. f. flavicarpa Degener, conhecida como maracujá azedo ou amarelo é a espécie mais cultivada e comercializada no Brasil. Desta forma, os objetivos deste trabalho foram: desenvolver e validar um método analítico por CLAE-UV/DAD (cromatografia líquida de alta eficiência acoplada detector de arranjo de fotodiodos) para quantificação da flavona isoorientina, presente na polpa de P. edulis; quantificação dos flavonoides totais desta espécie, usando um padrão de baixo custo (rutina); comparar as técnicas CLAE e CCDAE (cromatografia em camada delgada de alta eficiência) e analisar a isoorientina nas cascas dos frutos de P. edulis infectada com o vírus PWV e cascas sadias por CCDAE; quantificar as proteínas totais e avaliar as atividades antioxidantes e anti-inflamatória dos extratos de cascas de P. edulis e da polpa dos frutos de P. edulis e P. alata...

Utilização da técnica hifenada CLAE-DAD-IES-EM na detecção e caracterização de substâncias em Ocotea paranapiacabensis e Aniba firmula (Lauraceae)

Queiroz, Marcos Marçal Ferreira
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 129 f. : il.
POR
Relevância na Pesquisa
27.16%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Química - IQ; Este trabalho apresenta a aplicação da metodologia de análise in silico em frações da partição líquido-líquido obtidas a partir do extrato hidroalcoólico das folhas de Ocotea paranapiacabensis e Aniba firmula (Lauraceae). A abordagem utilizou os dados obtidos a partir da técnica hifenada CLAE-DAD-IES-EM, sendo esses dados analisados e contrastados com a base de dados do Dictionary of Natural Products (DNP), a fim de se detectar metabólitos secundários previamente isolados nos gêneros Ocotea e Aniba. A partir da obtenção desses dados, foi possível direcionar o estudo das frações analisadas para a identificação de novas substâncias nos gêneros estudados. Utilizando a metodologia, foram detectadas, estruturas isoméricas de alcalóides aporfinóides e dois flavonóides monoglicosilados nas folhas de O. paranapiacabensis. Não há relatos desses flavonóides em espécies do gênero Ocotea, o que levou ao planejamento de uma estratégia para o isolamento desses constituintes, que tiveram sua estrutura elucidada através da análise de RMN 1H e 13C. A abordagem utilizada no estudo da fração acetato de etila das folhas de A. firmula possibilitou a detecção de quatro substâncias da classe das estirilpironas (1- 4)...

Detecção in silico dos constituintes majoritários de Strychnos brasiliensis e S. pseudoquina (Loganiaceae) usando CLAE-DAD/EMAR

Matos, Alice Tereza Sampaio de
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 90 f. : il.
POR
Relevância na Pesquisa
27.37%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Química - IQ; O Núcleo de Bioensaios, Biossíntese e Ecofisiologia de Produtos Naturais (NuBBE) condensa, em suas atividades de pesquisa, o estudo de micromoléculas bioativas provenientes de plantas do Cerrado e Mata Atlântica Paulistas. Nos últimos anos o NuBBE investe no desenvolvimento de metodologias analíticas de derreplicação, utilizando diversas técnicas acopladas, tais como, CLAE/DEQ-DAD, EMAR/CLAE-DAD e EM/CLAE-DAD, para acelerar a escolha de extratos vegetais brutos. Técnicas analíticas de detecção in silico vêm sendo incorporadas às metodologias cromatográficas de construção de perfis micromoleculares, auxiliando na seleção apenas dos metabólitos de interesse presentes em matrizes brutas. Nesta dissertação foi abordado o estudo dos extratos de Strychnos brasiliensis e S. pseudoquina (Loganiaceae) através de bioensaios de atividade antioxidante e de inibição de polimerização da hematina. Esses bioensaios revelaram a fração acetato de etila, dos galhos de S. brasiliensis, como matriz promissora em ambos os testes assim como os galhos de S. pseudoquina com potencial atividade antioxidante. A fração acetato de etila dos galhos de S. brasiliensis e o extrato bruto das folhas de S. pseudoquina foram avaliados fazendo uso da técnica hifenada EMAR/CLAE-DAD. Como resultado desta análise...

Detecção in silico e caracterização dos constituintes micromoleculares majoritários do fungo endofítico Colletotrichum gloeosporioides isolado de folhas de Garcinia xanthochymus usando HPLC-DAD-HRMS e GC-MS

Cardoso, Patrícia
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 119 f. : il.
POR
Relevância na Pesquisa
27.29%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Química - IQ; O fungo endofítico Colletotrichum gloeosporioides isolado de Garcinia xanthochymus, foi cultivado em pequena escala nos meios líquidos, (400 mL) MDB, Extrato de Malte, YM, Czapek e em meio sólido (150 g) de milho tipo canjica, a 28ºC, em regime estático. Após triagem por ensaios biológicos, e análise por 1H RMN e HPLC-DAD, os meios de milho e extrato de malte foram selecionados para o estudo químico, sendo cultivados em larga escala. As matrizes brutas foram submetidas a estratégias de separação e de desreplicação utilizando as técnicas hifenadas: cromatografia líquida acoplada a detector de arranjo de diodos e espectrometria de massas de alta resolução, cromatografia gasosa acoplada a espectrometria de massas e também a ressonância magnética nuclear, sendo a detecção dos constituintes majoritários realizada in silico, através do uso de bases de dados públicas e pertencentes ao NuBBE. Os experimentos realizados permitiram a detecção de 14 substâncias: 6 por CG-MS (extrato DCM de milho) – dihexadecanoato de glicerila (1); trioctadec-9-enoato de glicerila (2); sn1`, 2` octadeca-9,12-dienoato de glicerila (3); sn1`...

Comparison of diode array and electrochemical detection in the C30 reverse phase HPLC analysis of algae carotenoids

Guaratini,Thais; Cardozo,Karina H. M.; Pinto,Ernani; Colepicolo,Pio
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
27.16%
Qualitative and quantitative determination of carotenoids pigments can provide valuable information about the organisms in which this important class of compounds is found. In the HPLC analysis of pigments, diode array (DAD), electrochemical (ED) and other kinds of detector may be used. The aim of this work is to develop an HPLC method using a C30 column to identify and quantify sixteen different pigments from algae. A further aim is to compare precision and accuracy obtained by DAD and ED. ED is normally more sensible than DAD. On the other hand, the highest precision and accuracy was obtained with DAD. In conclusion, the method was efficient for quantitative and qualitative analyses of pigments from cyanobacteria and different microalgae classes. Their pigment patterns for several organisms are also discussed.

Lrp is a direct repressor of the dad operon in Escherichia coli.

Mathew, E; Zhi, J; Freundlich, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1996 EN
Relevância na Pesquisa
27.4%
Expression of the degradative D-amino acid dehydrogenase (dad) operon is known to be increased when Escherichia coli is grown in the presence of D- or L-alanine. Alanine is thought to act as an inducer to block the action of a postulated repressor. This operon is also believed to be regulated by catabolite repression. We have used in vivo and in vitro experiments that show that the dad repressor is the leucine-responsive regulatory protein (Lrp). dad expression in a dad-lacZ operon fusion strain was increased four- to sevenfold when cells were grown in minimal medium containing alanine or leucine. A strain lacking Lrp had high-level constitutive dad expression. Gel retardation and footprinting studies revealed that Lrp binds in vitro to multiple sites over a large area in the dad promoter region. This binding was reduced by alanine or leucine. In vitro transcription assays, using a plasmid template and primer extension analysis, identified three major dad transcripts (Tr1, Tr2, and Tr3). The formation of these transcripts was differentially regulated by cyclic AMP-cyclic AMP receptor protein complex, and each was strongly repressed by Lrp. Alanine or leucine completely (for Tr1 and Tr2) or partially (for Tr3) reversed Lrp inhibition. Site-directed mutagenesis of an Lrp binding site strongly reduced Lrp binding and prevented Lrp repression of dad transcription in vivo and in vitro. Taken together...

dad-1, an endogenous programmed cell death suppressor in Caenorhabditis elegans and vertebrates.

Sugimoto, A; Hozak, R R; Nakashima, T; Nishimoto, T; Rothman, J H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/09/1995 EN
Relevância na Pesquisa
27.42%
Programmed cell death (apoptosis) is a normally occurring process used to eliminate unnecessary or potentially harmful cells in multicellular organisms. Recent studies demonstrate that the molecular control of this process is conserved phylogenetically in animals. The dad-1 gene, which encodes a novel 113 amino acid protein, was originally identified in a mutant hamster cell line (tsBN7) that undergoes apoptosis at restrictive temperature. We have identified a dad-1 homologue in Caenorhabditis elegans (Ce-dad-1) whose predicted product is > 60% identical to vertebrate DAD-1. A search of the sequence databases indicated that DAD-1-like proteins are also expressed in two plant species. Expression of either human dad-1 or Ce-dad-1 under control of a C.elegans heat-shock-inducible promoter resulted in a reduction in the number of programmed cell death corpses visible in C.elegans embryos. Extra surviving cells were present in these animals, indicating that both the human and C.elegans dad-1 genes can suppress developmentally programmed cell death. Ce-dad-1 was found to rescue mutant tsBN7 hamster cells from apoptotic death as efficiently as the vertebrate genes. These results suggest that dad-1, which is necessary for cell survival in a mammalian cell line...

The formin DAD domain plays dual roles in autoinhibition and actin nucleation

Gould, Christopher J.; Maiti, Sankar; Michelot, Alphée; Graziano, Brian R.; Blanchoin, Laurent; Goode, Bruce L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.33%
Formins are a large family of actin assembly-promoting proteins with many important biological roles [1-3]. However, it has remained unclear how formins nucleate actin polymerization. All other nucleators are known to recruit actin monomers as a central part of their mechanisms [3-5]. However, the actin-nucleating FH2 domain of formins lacks appreciable affinity for monomeric actin [6, 7]. Here, we found that yeast and mammalian formins bind actin monomers, but this activity requires their C-terminal DAD domains. Further, we observed that the DAD works in concert with the FH2 to enhance nucleation without affecting the rate of filament elongation. We dissected this mechanism in mDia1, mapped nucleation activity to conserved residues in the DAD, and demonstrated that DAD roles in nucleation and autoinhibition are separable. Further, DAD enhancement of nucleation was independent of contributions from the FH1 domain to nucleation [8]. Together, our data show that: (i) the DAD has dual functions in autoinhibition and nucleation, (ii) the FH1, FH2 and DAD form a tri-partite nucleation machine, and (iii) formins nucleate by recruiting actin monomers, and therefore are more similar to other nucleators than previously thought.

Clinical and therapeutic aspects in dento-alveolar disharmony (DAD) with crowding

Rauten, Anne-Marie; Şurlin, Petra; Olteanu, Mădălina; Maglaviceanu, Camelia; Popescu, M.R.; Teodorescu, Elina
Fonte: Medical University Publishing House Craiova Publicador: Medical University Publishing House Craiova
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.24%
Dento-alveolar disharmony (DAD) with crowding represents a predispose factor for periodontal pathology installing, especially when septic inflammation is associated. In this context, the identification of integrity or presence of the periodontal structure modifications becomes essential, any discovered element of periodontal pathology transforming into an important factor for a correct and beneficial orthodontic or periodontal-orthodontic therapy setup. The purpose of our study was to reveal the relations between the DAD existence and periodontal modifications within a lot of 528 subjects of 7 to 19 years old wearing different DAD who asked for an orthodontic control, and also the effects of orthodontic therapy upon periodontal structures for the situations in which this therapy was instituted. 74,87% was the percentage for patients with DAD and crowding who accepted the initiation of an orthodontic treatment and 12,75% of them had a friable C type periodontium (with great possibility to evolve towards a periodontal pathology), 25,62% had chronic gingivitis, and in 15,43% there have been noticed gingival recessions more than 2 mm. The orthodontic treatment was finalized for 44,96% of the patients, in 13,43% we noticed the persistence of C type periodontium...

A Comparative Study of Newly Developed HPLC-DAD and UHPLC-UV Assays for the Determination of Posaconazole in Bulk Powder and Suspension Dosage Form

Hamdy, Dalia A.; Belal, Tarek S.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.16%
Objective. To develop and compare HPLC-DAD and UHPLC-UV assays for the quantitation of posaconazole in bulk powder and suspension dosage form. Methods. Posaconazole linearity range was 5–50 μg/mL for both assays. For HPLC-DAD assay, samples were injected through Zorbax SB-C18 (4.6 × 250 mm, 5 μm) column. The gradient elution composed of the mobile phase acetonitrile: 15 mM potassium dihydrogen orthophosphate (30 : 70 to 80 : 20, linear over 7 minutes) pumped at 1.5 mL/min. For UHPLC-UV assay, samples were injected through Kinetex-C18 (2.1 × 50 mm, 1.3 μm) column. The mobile phase composed of acetonitrile: 15 mM potassium dihydrogen orthophosphate (45 : 55) pumped isocratically at 0.4 mL/min. Detection wavelength was 262 nm in both methods. Results. The run time was 11 and 3 minutes for HPLC-DAD and UHPLC-UV assays, respectively. Both assays were linear (r2 > 0.999) with CV% and % error of the mean <3%. Limits of detection and quantitation were 0.82 and 2.73 μg/mL for HPLC-DAD and 1.04 and 3.16 μg/mL for UHPLC-UV, respectively. The methods quantitated PSZ in suspension dosage form with no observable interferences. Conclusions. Both assays were proven sensitive and selective according to ICH guidelines. UHPLC-UV assay exhibited some economic and chromatographic separation superiority.

Desenvolvimento e validação de método por CLAE-DAD para determinação simultânea de Captopril, Hidroclorotiazida e seus compostos relacionados e avaliação da equivalência farmacêutica de medicamentos anti-hipertensivos

Hess, Bianca Sarturi
Fonte: Universidade Federal do Paraná Publicador: Universidade Federal do Paraná
Tipo: Dissertação Formato: 169f. : il. algumas color., grafs., tabs.; application/pdf
PORTUGUêS
Relevância na Pesquisa
27.24%
Orientador : Prof. Dr. Roberto Pontarolo; Orientador : Dr. Marco André Cardoso; Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Ciências Farmacêuticas. Defesa: Curitiba, 29/03/2011; Inclui referências; Área de concentração: Insumos, medicamentos e correlatos; Resumo: Neste trabalho os fármacos anti-hipertensivos captopril e hidroclorotiazida foram alvo de estudo por duas abordagens: (a) analítica, com o objetivo de desenvolver e validar método por CLAE-DAD para sua determinação e de seus compostos relacionados simultaneamente em comprimidos e (b) do ponto de vista do controle de qualidade com o objetivo de avaliar a equivalência farmacêutica e perfil de dissolução dos medicamentos disponíveis comercialmente que os contenham separadamente ou associados. Foi desenvolvido e validado um método rápido e econômico utilizando CLAE-DAD para quantificação de captopril (CAP), hidroclorotiazida (HCTZ) e seus principais compostos relacionados: dissulfeto de captopril (CAD), clorotiazida (CTZ) e benzotiadiazina (BTDZ). O método foi desenvolvido e validado através de um sistema cromatográfico composto por uma coluna Agilent Zorbax Eclipse XDB-Phenyl 5 ?m...

Otimização evalidação de métodos analíticos para a determinação simultânea de tuberculostáticos (4-FDC) por CLAE/DAD e CLUE/ DAD

Paiva, Marcelo Vitor de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciências Farmacêuticas; Bioanálises e Medicamentos Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciências Farmacêuticas; Bioanálises e Medicamentos
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
27.24%
Tuberculosis is a serious disease, but curable in practically 100% of new cases, since complied the principles of modern chemotherapy. Isoniazid (ISN), Rifampicin (RIF), Pyrazinamide (PYR) and Chloride Ethambutol (ETA) are considered first line drugs in the treatment of tuberculosis, by combining the highest level of efficiency with acceptable degree of toxicity. Concerning USP 33 - NF28 (2010) the chromatography analysis to 3 of 4 drugs (ISN, PYR and RIF) last in average 15 minutes and 10 minutes more to obtain the 4th drug (ETA) using a column and mobile phase mixture different, becoming its industrial application unfavorable. Thus, many studies have being carried out to minimize this problem. An alternative would use the UFLC, which is based with the same principles of HPLC, however it uses stationary phases with particles smaller than 2 μm. Therefore, this study goals to develop and validate new analytical methods to determine simultaneously the drugs by HPLC/DAD and UFLC/DAD. For this, a analytical screening was carried out, which verified that is necessary a gradient of mobile phase system A (acetate buffer:methanol 94:6 v/v) and B (acetate buffer:acetonitrile 55:45 v/v). Furthermore, to the development and optimization of the method in HPLC and UFLC...

Desenvolvimento e validação de método analítico para determinação de WE010, WE014 e WE017

Brito, Wanessa Azevedo de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciências Farmacêuticas; Bioanálises e Medicamentos Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciências Farmacêuticas; Bioanálises e Medicamentos
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
27.4%
The synthetic guanylhydrazones WE010 (3,5-di-tert-butil-4-hidroxibenzaldehyde-guanylhydrazone), WE014 (4-bifenilcarboxialdehydeguanylhydrazone) and WE017 (3,4-diclorobenzaldehydeguanylhydrazone) showed high cytotoxic activity in terms of percentage inhibition of cancer cells growth. However, further progress in the development of these drug candidates requires precise and convenient methods for their qualitative and quantitative analyses. The aim of this study was to develop and validate High Performance Liquid Chromatography with diode-array detection (HPLC-DAD) and Ultra Fast Liquid Chromatography with diode-array detection (UFLC-DAD) methods suitable for as simultaneous as isolated determination of studied guanylhydrazones, based on the optimization of chromatographic parameters and obtaining reduced detection times. The chromatographic analyses of analytes by HPLC were performed on C18 ACE analytical column (150 mm x 4.6 mm), with a particle size of 5.0 μm. Among all the conditions assayed, the best results of separation were obtained with a mixture of methanol:water (60:40, v/v) as the mobile phase at a flow rate 1.5mL/min and pH of 3.5 adjusted at acetic acid. The UFLC method was developed by experimetal desing techniques in order to find optimal chromatographic analytical conditions...

STRATEGIA ANALITICA PER LA CARATTERIZZAZIONE DEL PROFILO VITAMINICO LIPOSOLUBILE E CAROTENOIDEO DEL LATTE DI DIFFERENTI SPECIE ANIMALI MEDIANTE IFENAZIONE HPLC-DAD-TANDEM MS

BELLANTE, SIMONA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
27.29%
Vitamin determination is a complex and challenging task, especially when aimed at the analysis of biological and food samples. Milk is a unique matrix, being at the same time biological fluid and food with the chemical characteristics of three phases: emulsion, suspension and colloidal solution. Furthermore, it is an almost complete food and an excellent source of vitamins, in particular vitamins A, B1, B2, B5 and B12. The water-soluble vitamins occur in the serum, while the fat-soluble vitamins and carotenoids are associated to the lipid fraction. Bovine milk has been one of the most investigated food matrices, but also milk from other animal species deserve to be investigated since it is essential for human diet in several parts of the world. As a matter of fact, India and Pakistan are the main producers of buffalo milk, the second most produced in the world after bovine milk. Europe, China and some zones of Africa are excellent producers of sheep milk, while goat milk is produced in some parts of Asia and in the countries of the Mediterranean area. Donkey milk has a niche market, but it is considered a valuable alternative for people who are allergic to cow milk. In the scientific literature, a large number of papers have focused on the macronutrient composition of bovine milk...

The ghost of Dad Rudd, On the Stump

Lamond, Julieanne
Fonte: Association for the Study of Australian Literature (online access via NLA web site); http://asaliterature.com/ Publicador: Association for the Study of Australian Literature (online access via NLA web site); http://asaliterature.com/
Tipo: Journal article; Published Version Formato: 14 pages
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This paper examines the cultural and political legacies of Dad Rudd, a fictional character who first appeared in short stories by “Steele Rudd” (A.H.Davis) in the Bulletin in 1895 and has since appeared in popular fiction, theatre, film, television and radio adaptations throughout the twentieth century. It traces a set of national tropes – particularly that of the battler - through stump speeches made by Dad Rudd in On Our Selection! (1899), Dad in Politics (1908), the stage melodrama On Our Selection (1912), and Ken G. Hall’s film Dad Rudd, M.P.(1940), and considers how they have continued to be used to create both political and cultural constituencies in Australia.

Analysis of flavonoids in Rubus erythrocladus and Morus nigra leaves extracts by liquid chromatography and capillary electrophoresis

Tallini,Luciana R.; Pedrazza,Graziele P.R.; Bordignon,Sérgio A. de L.; Costa,Ana C.O.; Steppe,Martin; Fuentefria,Alexandre; Zuanazzi,José A.S.
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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AbstractThis study uses high performance liquid chromatography and capillary electrophoresis as analytical tools to evaluate flavonoids in hydrolyzed leaves extracts of Rubus erythrocladus Mart., Rosaceae, and Morus nigra L., Moraceae. For phytochemical analysis, the extracts were prepared by acid hydrolysis and ultrasonic bath and analyzed by high performance liquid chromatography using an ultraviolet detector and by capillary electrophoresis equipped with a diode-array detector. Quercetin and kaempferol were identified in these extracts. The analytical methods developed were validated and applied. Quercetin and kaempferol were quantified in R. erythrocladus, with 848.43 ± 66.68 μg g-1 and 304.35 ± 17.29 μg g-1, respectively, by HPLC-UV and quercetin, 836.37 ± 149.43 μg g-1, by CE-DAD. In M. nigra the quantifications of quercetin and kaempferol were 2323.90 ± 145.35 μg g-1 and 1446.36 ± 59.00 μg g-1, respectively, by HPLC-UV and, 2552.82 ± 275.30 μg g-1 and 1188.67 ± 99.21 μg g-1, respectively, by CE-DAD. The extracts were also analyzed by ultra-performance liquid chromatography coupled with a diode-array detector and mass spectrometer (MS), UPLC-DAD/MS.

Étude sur la reconnaissance de l'ubiquitine par les domaines de transactivation acides des activateurs de transcription

Lussier-Price, Mathieu
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Les domaines de transactivation (TAD) acides sont présents dans plusieurs protéines oncogéniques, virales et dans des facteurs de différenciation de cellules souches. Ces domaines acides contrôlent la transcription à travers une myriade d’interactions avec divers partenaires ce qui provoque l’activation de la transcription ou leur propre élimination. Cependant, dans la dernière décennie, de plus en plus de recherches ont démontré que les TAD possédaient un sous-domaine activation/dégradation (DAD) responsable pour une fonction d'activation de la transcription dépendante de la dégradation de la protéine. Un tel phénomène peut être accompli par plusieurs moyens tels que des modifications post-traductionnelles, l’association à des cofacteurs ou la formation d’un réseau d’interaction complexe en chaînes. Or, aucune preuve concrète n’a pu clairement démontrer le fonctionnement de la dépendance paradoxale entre ces deux fonctions sur un activateur de transcription. Le DAD, a été observé dans plusieurs facteurs de transcription incluant la protéine suppresseur de tumeur p53 et le facteur de différenciation érythrocyte EKLF. Un aspect particulier des DAD est que la composition de leur séquence d’acide aminé est fortement similaire à celle des domaines de liaison à l’ubiquitine (UBD) qui jouent un rôle clé dans le contrôle de la transcription à travers leur interaction non-covalente avec l’ubiquitine. Ainsi...

GC-FID and HPLC-DAD Methods for the Determination of Menadione Sodium Bisulphite Directly and by Converting Menadione Sodium Bisulphite to Menadione in Pharmaceutical Preparation

Demirkaya-Miloglu, Fatma; Kadioglu, Yucel; Senol, Onur
Fonte: Shaheed Beheshti University of Medical Sciences Publicador: Shaheed Beheshti University of Medical Sciences
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
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was performed in both direct analysis of MSB and analysis of MN by converting MSB to MN with sodium carbonate. GC-FID method was carried out on the HP-5 capillary column GC-FID and HPLC-DAD methods were developed for determination of menadione (MN) and menadione sodium bisulphite (MSB). By means of each method, quantitative analysis of MSB in commercial pharmaceutical using nitrogen gas. HPLC-DAD method was achieved on the reversed phase C8 column by using a mobile phase consisting methanol and water. The calibration curves of GC-FID and HPLC-DAD for both analytes were linear in the same concentration range (0.5–20 μg/mL). Both methods were validated in terms of precision, accuracy, recovery and limits of detection (LOD) and quantitation (LOQ). Although LOD values of HPLC-DAD method (0.010 μg/mL for MN and 0.005 μg/mL for MSB) is lower than obtained values with GC-FID method (0.04 μg/mL for MN and 0.06 μg/mL for MSB), both methods gave similar and favorable results in terms of precision and accuracy. The Student's t-test was applied to investigate the significant of the different between the results of MSB determination with direct analysis of MSB and analysis of MN by converting MSB to MN by means of GC-FID and HPLC-DAD method in dosage form.