17 research outputs found
Thiol-disuplhide redox equilibria of glutahione metaboloma compounds investigated by tandem mass spectrometry
No full textThe thiol group of cysteine plays a pivotal role in structural and functional biology. We use mass spectrometry to study glutathione-related homo- and heterodimeric disulfides, aiming at understanding the factors affecting the redox potentials of different disulfide/thiol pairs. Several electrospray ionization (ESI)-protonated disulfides of cysteamine, cysteine, penicillamine, N-acetylcysteine, N-acetylpenicillamine, γGluCySH, HSCyGly, and glutathione were analyzed on a triple quadrupole instrument to measure their energy-resolved tandem mass spectra. Fission of the disulfide bond yields RSH*H+ and RS+ ions. The logarithm of the intensity ratio of the RS+/RSH*H+ fragments in homodimeric disulfides is proportional to the normal reduction potential of their RSSR/RSH pairs determined by nuclear magnetic resonance (NMR) in solution, the more reducing ones yielding the higher ratios. Also in some R1S-SR2 disulfides, the ratio of the intensities of the RSHRHR and RSR ions of each participating thiol shows a linear relationship with the Nernst equation potential difference of the corresponding redox pairs. This behavior allows us to measure the redox potentials of some disulfide/thiol pairs by using different thiol-reducing probes of known oxidoreductive potential as reference. To assist understanding of the fission mechanism of the disulfide bond, the fragments tentatively identified as 'sulfenium' were themselves fragmented; accurate mass measurement of the resulting second-generation fragments demonstrated a loss of thioformaldehyde, thus supporting the assigned structure of this elusive intermediate of the oxidative stress pathway. Understanding this fragmentation process allows us to employ this technique with larger molecules to measure by mass spectrometry the micro-redox properties of different disulfide bonds in peptides with catalytic and signaling biological activity. Copyrigh
Measurement of S-methylcysteine and S-methyl-mercapturic acid in human urine by alkyl-chloroformate extractive derivatization and isotope-dilution gas chromatography–mass spectrometry
No full textS-methylcysteine (SMC) is a minor amino acid naturally excreted in human urine, a protective agent against oxidative stress and a biotransformation product of the fumigant biocide methyl bromide and of nicotine. A metabolic source of SMC is catabolism of the repair catalytic protein MGMT (EC 2.1.1.37), which specifically removes the methyl group from the modified DNA nucleotide O-6-methyl-guanine to revert the normal GC base pairing. To assess the value of SMC and of S-methylmercapturic acid (SMMA) as candidate biomarkers of proliferative phenomena, a sensitive analytical method by GC-MS was applied in a pilot study of healthy subjects to assess their urinary elimination and the intra- and inter-individual variability. Extractive alkylation with butylchloroformate-n-butanol-pyridine (Husek technique) was employed for sample derivatization and isotope dilution GC-MS with S-[CD3]-SMC and -SMMA was applied for specific and sensitive detection. To resolve the target analytes from the main coeluting interferents in the derivatized urine extract a medium-polarity stationary phase was employed. SMMA was not detected in the morning urine of three healthy fertile-age women followed for one month above the minimum detectable level of approx. 500 μg/L while SMC concentrations were in the 0.02–0.7 μg/mL range (n = 61) with large inter-day and inter-individual variations. In a young healthy male urine samples taken throughout a few days yielded concentrations in the same 90–810 μg/L range (n = 11). These preliminary results points at SMC as a candidate biomarker for the study of methylation turnover in several biochemical processes
Vecchie cultivar di pero (Pyrus communis L.) censite nel Casentino (Arezzo-Toscana): caratterizzazione morfologica, biometrica e molecolare (SSR).
No full textGeometrical aspects of Co(K,X) spaces
No full textEste trabalho tem dois objetivos principais. Primeiramente, estudamos as cópias complementadas de co(T) em espaços de Banach, onde T é um cardinal infinito. Estendemos ao caso não-enumerável um resultado clássico obtido por T. Schlumprecht que caracteriza as cópias complementadas de co em um espaço de Banach X. Usamos esta nova caracterização para estender resultados de G. Emmanuele, F. Bombal, D. Leung e F. Räbiger envolvendo as cópias complementadas de co nos espaços de Banach clássicos `p(I,X), onde p T[1, ∞ ] e I é um conjunto não-vazio. Nós também provamos um novo resultado sobre as cópias complementadas de co(T) nos espaços Co(K,X), onde K é um espaço de Hausdor localmente compacto. Em seguida, estudamos uma extensão vetorial do clássico Teorema de Banach-Stone obtida por K. Jarosz. Estudando várias constantes introduzidas por R. James, J. Schäer, M. Baronti, E. Casini e P. Pappini, nós provamos uma nova relação entre os módulos de convexidade dos espaços Xe X*, que possui interesse independente. Esta relação é usada para provar uma nova reneralização vetorial do Teorema de Banach-Stone que simultaneamente estende o Teorema de Jarosz e também mostra que este último resultado é, de fato, uma consequência de um teorema obtido recentemente por F. Cidral, E. Galego e M. RincónVillamizar.The goal of this work is two-fold. First, we study the complemented copies of co(T) in Banach spaces, where T is an innite cardinal. We extend to the uncountable case a classical result by T. Schulmprecht that characterizes the complemented copies of co in a Banach space X. We use this new characterization to extend results by G. Emmanuele, F. Bombal, D. Leung and F. Räbiger concerning the complemented copies of co in the classical Banach spaces `p(I,X), where p T[1, ∞ ] and I is a non-empty set. We also obtain a new result involving the complemented copies of co(T) in Co(K,X) spaces, where Kis a locally compact Hausdor space. Next, we turn our attention to a vector-valued extension of the classical Banach-Stone theorem obtained by K. Jarosz. Studying several constants introduced by R. James, J. Schäffer, M. Baronti, E. Casini and P. Pappini, we obtain a new relationship between the moduli of convexity of Xand X*, which has independent interest. We then apply this relationship to prove a new X-valued generalization of the Banach-Stone theorem that simultaneously extends the aforementioned result by Jarosz and also shows that this result is, in fact, a consequence of a theorem obtained recently by F. Cidral, E. Galego and M. Rincón-Villamizar
Leadership and key performance indicators for market access team and institutional sales of the pharmaceutical industry in Brazil
No full textEsta dissertação objetiva analisar o papel da liderança e a implementação de indicadores de desempenho às equipes de acesso da indústria farmacêutica que atendem o segmento de pagadores institucionais de medicamentos, sejam eles o governo, planos de saúde ou grandes empresas. A dinâmica desta nova estrutura de negócios configura-se no modelo B2B, Business to Business, ou seja, no estabelecimento de relações comerciais corporativas em oposição ao modelo tradicional médico-paciente-farmácia, denominado no escopo deste estudo, como B2C, Business to Consumer. A pesquisa de campo foi realizada por meio de entrevista pessoal, com questionário pré-elaborado com uma parte de perguntas dissertativas e outra de múltiplas-escolha. A amostra contou com seis líderes de equipe de seis diferentes indústrias farmacêuticas, todas multinacionais e com alta representatividade no volume de negócios do segmento, o que confere uma base relevante à pesquisa. Nos resultados, destacou-se a ausência de indicadores consistentes capazes de medir de forma eficiente o desempenho das equipes. Ao mesmo tempo, percebe-se uma dicotomia no papel da liderança frente a esta nova dinâmica de negócio e de equipe, uma vez que os líderes pesquisados reforçaram em linhas gerais a necessidade de delegar e atuar de forma mais estratégica por ter a frente uma equipe com perfil mais experiente, mas simultaneamente, foi apresentado um incomodo com a ausência de mecanismos de controle mais sólidos como os indicadores de desempenho. Na ausência de tais indicadores torna-se imperativo maior qualificação e maturidade dos líderes e lideradosThis study aims to analyze the role of leadership and implementation of performance indicators to teams of access of the pharmaceutical industry that meet the segment of institutional payers of medicines, be they the government, HMO´s or large companies. The dynamics of this new structure of business is configured in the model B2B, Business to Business, i.e. on the establishment of trade relations corporate as opposed to the traditional model doctor-patient-pharmacy, called in the scope of this study, such as B2C, Business to Consumer. The field research was carried out by means of personal interview, through of a questionnaire pre-prepared with a part of questions interrogations and other multiple-choice. The sample consisted of six leaders of the team of six different pharmaceutical industries, all multinationals and with high representatives of the turnover of the segment, which provides a relevant basic research. In the results, it was highlighted the lack of indicators consistent in order to measure in an efficient manner the performance of the teams. At the same time, we perceive a dichotomy in the role of leadership in this new dynamic of business and of the team, since the leaders surveyed have strengthened in general lines the need to delegate and to act in a more strategic to have a team with a profile more experienced, but at the same time, it was presented a discomfort with the absence of mechanisms to control more solid as their own performance indicators. In the absence of indicators it becomes imperative higher qualification and maturity of the leaders and the tea
Inherently Chiral Macrocyclic Oligothiophenes: Easily Accessible Electrosensitive Cavities with Outstanding Enantioselection Performances
No full textLinear conjugated oligothiophenes of variable length and different substitution pattern are ubiquitous in technologically advanced optoelectronic devices, though limitations in application derive from insolubility, scarce processability and chain-end effects. This study describes an easy access to chiral cyclic oligothiophenes constituted by 12 and 18 fully conjugated thiophene units. Chemical oxidation of an “inherently chiral” sexithiophene monomer, synthesized in two steps from commercially available materials, induces the ormation of an elliptical dimer and a triangular trimer endowed with electrosensitive cavities of different tunable sizes. Combination of chirality with electroactivity makes these molecules unique in the current oligothiophenes literature. These macrocycles, which are stable and soluble in most organic solvents, show outstanding chiroptical properties, high circularly polarized luminescence effects and an exceptional enantiorecognition ability
Photocatalysis for the degradation of ionic surfactants in water: the case of DPC
No full textTraditional techniques to remove contaminants (carbon adsorption, incineration, biological activity and chemical treatment) have a lot of disadvantages. Advanced Oxidation processes (AOP’s) are used as alternative processes in the degradation of surfactants and in general for wastewater treatment. They are based on the generation of OH·, one of the most powerful oxidant known (E° = 2.73 V) and capable to react non-selectively with any organic compound.
In the present work, the degradation of a cationic surfactant (dodecylpyridinium chloride (DPC)) was performed. The photodegradation reaction was investigated both in a slurry reactor and in a vessel where the photocatalyst (P25 by Degussa) was anchored onto an aluminum surface to
avoid the final filtration of the powder at the end of the reaction. Moreover a new photoreactor was built on purpose to investigate the influence of the pressure on the degradation process
Movilidad peatonal y seguridad ciudadana. Evaluación de intervenciones urbanas en el espacio público de la comuna de La Granja
No full textTesis para optar al grado de Magíster en UrbanismoLa seguridad ciudadana es actualmente una de las demandas más importantes realizadas desde la población hacia los gobiernos. Esta demanda se ha sentir en los Municipios, por ser la persona jurídica de carácter público más inmediata a los individuos y grupos sociales de carácter local. Este trabajo propone analizar mediante evaluación ex post, 5 etapas de construcción del Programa Paseos Peatonales en el espacio público, realizados en la comuna de La Granja por parte del Gobierno Local, entre los años 2006 y 2012 en Chile. Los cuales surgen como una respuesta inmediata hacia la ciudadanía para generar aumento de seguridad, disminución del miedo en el barrio y como una invitación a apropiarse del espacio público mediante el uso y la movilidad peatonal. El tipo de investigación es la utilización de métodos cuantitativos y cualitativos, para medir la seguridad y uso en los espacios intervenidos, calificar el mejoramiento en cuanto a la calidad de lo construido e identificar modificaciones a estos diseños, posibles de ser considerados en otras etapas de construcción del Programa. Para analizar dichos objetivos específicos, se delimitan polígonos de estudios, se selecciona una muestra para la realización de encuestas y entrevistas en diferentes actores, observaciones en terreno y recorridos peatonales del espacio público intervenido junto con la revisión bibliográfica
Inherently Chiral Macrocyclic Oligothiophenes: Easily Accessible Electrosensitive Cavities with Outstanding Enantioselection Performances
No full textLinear conjugated oligothiophenes of variable length and different substitution pattern are ubiquitous in technologically advanced optoelectronic devices, though limitations in application derive from insolubility, scarce processability and chain-end effects. This study describes an easy access to chiral cyclic oligothiophenes constituted by 12 and 18 fully conjugated thiophene units. Chemical oxidation of an “inherently chiral” sexithiophene monomer, synthesized in two steps from commercially available materials, induces the formation of an elliptical dimer and a triangular trimer endowed with electrosensitive cavities of different tunable sizes. Combination of chirality with electroactivity makes these molecules unique in the current oligothiophenes literature. These macrocycles, which are stable and soluble in most organic solvents, show outstanding chiroptical properties, high circularly polarized luminescence effects and an exceptional enantiorecognition ability
O CENTENÁRIO DO TAYLORISMO E OS ESTUDOS SOBRE LIDERANÇA
No full textEsse artigo revisita a centenária obra “Princípios da Administração Científica” escrita por Taylor no início do século XX. O objetivo é avaliar as contribuições de Taylor aos estudos sobre liderança, destacando a importância da leitura de uma obra seminal para o conhecimento em administração das organizações
