Quantification of alpha-amanitin in biological samples by HPLC using simultaneous UV- diode array and electrochemical detection

α-Amanitin is a natural bicyclic octapeptide, from the family of amatoxins, present in the deadly mushroom species Amanita phalloides. The toxicological and clinical interests raised by this toxin, require highly sensitive, accurate and reproducible quantification methods for pharmacokinetic studies. In the present work, a high-performance liquid chromatographic (HPLC) method with in-line connected diode-array (DAD) and electrochemical (EC) detection was developed and validated to quantify α-amanitin in biological samples (namely liver and kidney). Sample pre-treatment consisted of a simple and unique deproteinization step with 5% perchloric acid followed by centrifuga tion at 16,000. ×g, 4. °C, for 20. min. The high recovery found for α-amanitin (≥96.8%) makes this procedure suitable for extracting α-amanitin from liver and kidney homogenates. The resulting supernatant was collected and injected into the HPLC. Mobile phase was composed by 20% methanol in 50. mM citric acid, and 0.46. mM octanessulfonic acid, adjusted to pH 5.5. The chromatographic runs took less than 22. min and no significant endogenous interferences were observed at the α-amanitin retention time. Calibration curves were linear with regression coefficients higher than 0.994. The overall inter- and intra-assay precision did not exceed 15.3%.The present method has low interferences with simple and fast processing steps, being a suitable procedure to support in vivo toxicokinetic studies involving α-amanitin. In fact, the validated method was successfully applied to quantify α-amanitin in biological samples following intraperitoneal α-amanitin administration to rats. Moreover, human plasma was also used as matrix and the purposed method was adequate for detection of α-amanitin in that matrix. The results clearly indicate that the proposed method is suitable to investigate the pharmacokinetic and tissue distribution of α-amanitin. Additionally, the method will be very useful in the development of novel and potent antidotes against amatoxins poisoning and to improve the knowledge of α-amanitin toxicity.This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through project Pest- C/EQB/LA0006/2013. Juliana Garcia and Vera Marisa Costa thank FCT - Foundation for Science and Technology - for their PhD grant (SFRH/BD/74979/ 2010 ) and Post-doc grant (SFRH/BPD/63746/2009), respectively.info:eu-repo/semantics/publishedVersio

In situ Formation of Metal Nanoparticles through Electron Beam Irradiation: Modeling Real Materials from First-Principles Calculations

Advances in electron-matter studies, based on the irradiation of the electron beam in the transmission electron microscopy or field emission-scanning electron microscope on materials represents a preferred external physical and chemical tool for in situ remote command of the functional attributes of nanomaterials associated to its unique advantages of high spatial and temporal resolution and digital controllability. This makes the field of electron beam irradiation an emerging topic open for many researchers right now. Electron-material interactions envisage the formation, growth and coalescence of metal nanoparticles induced by electron beam irradiations and motivated by this discovery, in this Review, we provide an account of the recent advancements and theoretical developments to describe this phenomena and their applications. A theoretical framework is developed to determine the physical principles involved in the mechanism for the formation of metal nanoparticles on different materials by electron beam irradiation under the guidance of first-principles calculations at density functional level. New research directions are emerging in materials science to reach many applications by providing a deeper insight in the properties and phenomena in complex material systems. We conclude our work by briefly outlining the challenges that need to be addressed and the opportunities that can be tapped into. We hope that the review of the flourishing and vibrant topic with myriad possibilities would shine light on exploring the future directions of this research field by encouraging and opening the windows to meaningful multidisciplinary cooperation of researchers from different backgrounds and scientists from the fields such as chemistry, physics, engineering, biology, nanotechnology and materials science

A centralidade urbana e regional de Juiz de Fora (MG) - Brasil

A complexidade dos fenômenos urbanos e os estudos sobre as formas de assentamentos humanos sobre o território têm requerido uma retomada das questões regionais. Neste sentido, as reflexões contidas neste texto apresentam uma associação estreita entre o urbano e o regional, tendo como recorte espacial a cidade de Juiz de Fora (MG), Brasil, e sua região de influência direta. Propõe-se debater os movimentos de centralização e descentralização inter e intraurbanos e suas implicações em relação à concentração e dispersão de atividades na cidade nas duas escalas. O objetivo é analisar os planos e projetos intermediados pelas políticas públicas municipais, calcadas nas parcerias público-privadas e amparadas pela legislação urbana vigente, para responder à hipótese: tal quadro vem promovendo modificações na dinâmica regional de Juiz de Fora quando, em detrimento das necessidades locais, busca reafirmar o papel polarizador do município. A metodologia prevê abordar as diretrizes gerais, econômicas, políticas e técnicas locais. Na presente etapa de desenvolvimento da pesquisa, concluise que as transformações verificadas no quadro brasileiro e no modelo econômico atuais colocam uma agenda expandida de importantes desafios de identificar o papel das cidades na era da globalização e suas novas conexões com o espaço regional.The complexity of urban phenomena and the studies about ways of human settlements on the territory have requested a recovery of regional issues. In this regard, the considerations set in this paper presents a close association between the urban and the regional, having as spatial area the city of Juiz de Fora (MG), Brazil, and its area of direct influence. It is proposed to discuss the centralization and decentralization movements inter and intra urban and its implications regarding to the concentration and scattering of activities in the city in both scales. The goal is to look over the plans and projects mediated by municipal policy, sustained in public-private partnerships and supported by existing urban legislation, to respond the hypothesis: this situation has been promoting amendments in regional dynamics of Juiz de Fora while, in detriment of local needs, seeks to reaffirm the polarizing role of the municipality. The method intends to address the general, economic, political and local technical guidelines. In the present stage of development of this research, we concluded that the changes observed in the Brazilian scenario and the current economic model put an expanded list of important challenges of identifying the role of cities in the age of globalization and its new connections with the regional space.Eje 2: Forma y estructura urbana, organización del territorio, orientación del crecimiento.Facultad de Arquitectura y Urbanism

A centralidade urbana e regional de Juiz de Fora (MG) - Brasil

A complexidade dos fenômenos urbanos e os estudos sobre as formas de assentamentos humanos sobre o território têm requerido uma retomada das questões regionais. Neste sentido, as reflexões contidas neste texto apresentam uma associação estreita entre o urbano e o regional, tendo como recorte espacial a cidade de Juiz de Fora (MG), Brasil, e sua região de influência direta. Propõe-se debater os movimentos de centralização e descentralização inter e intraurbanos e suas implicações em relação à concentração e dispersão de atividades na cidade nas duas escalas. O objetivo é analisar os planos e projetos intermediados pelas políticas públicas municipais, calcadas nas parcerias público-privadas e amparadas pela legislação urbana vigente, para responder à hipótese: tal quadro vem promovendo modificações na dinâmica regional de Juiz de Fora quando, em detrimento das necessidades locais, busca reafirmar o papel polarizador do município. A metodologia prevê abordar as diretrizes gerais, econômicas, políticas e técnicas locais. Na presente etapa de desenvolvimento da pesquisa, concluise que as transformações verificadas no quadro brasileiro e no modelo econômico atuais colocam uma agenda expandida de importantes desafios de identificar o papel das cidades na era da globalização e suas novas conexões com o espaço regional.The complexity of urban phenomena and the studies about ways of human settlements on the territory have requested a recovery of regional issues. In this regard, the considerations set in this paper presents a close association between the urban and the regional, having as spatial area the city of Juiz de Fora (MG), Brazil, and its area of direct influence. It is proposed to discuss the centralization and decentralization movements inter and intra urban and its implications regarding to the concentration and scattering of activities in the city in both scales. The goal is to look over the plans and projects mediated by municipal policy, sustained in public-private partnerships and supported by existing urban legislation, to respond the hypothesis: this situation has been promoting amendments in regional dynamics of Juiz de Fora while, in detriment of local needs, seeks to reaffirm the polarizing role of the municipality. The method intends to address the general, economic, political and local technical guidelines. In the present stage of development of this research, we concluded that the changes observed in the Brazilian scenario and the current economic model put an expanded list of important challenges of identifying the role of cities in the age of globalization and its new connections with the regional space.Eje 2: Forma y estructura urbana, organización del territorio, orientación del crecimiento.Facultad de Arquitectura y Urbanism

A centralidade urbana e regional de Juiz de Fora (MG) - Brasil

A complexidade dos fenômenos urbanos e os estudos sobre as formas de assentamentos humanos sobre o território têm requerido uma retomada das questões regionais. Neste sentido, as reflexões contidas neste texto apresentam uma associação estreita entre o urbano e o regional, tendo como recorte espacial a cidade de Juiz de Fora (MG), Brasil, e sua região de influência direta. Propõe-se debater os movimentos de centralização e descentralização inter e intraurbanos e suas implicações em relação à concentração e dispersão de atividades na cidade nas duas escalas. O objetivo é analisar os planos e projetos intermediados pelas políticas públicas municipais, calcadas nas parcerias público-privadas e amparadas pela legislação urbana vigente, para responder à hipótese: tal quadro vem promovendo modificações na dinâmica regional de Juiz de Fora quando, em detrimento das necessidades locais, busca reafirmar o papel polarizador do município. A metodologia prevê abordar as diretrizes gerais, econômicas, políticas e técnicas locais. Na presente etapa de desenvolvimento da pesquisa, concluise que as transformações verificadas no quadro brasileiro e no modelo econômico atuais colocam uma agenda expandida de importantes desafios de identificar o papel das cidades na era da globalização e suas novas conexões com o espaço regional.The complexity of urban phenomena and the studies about ways of human settlements on the territory have requested a recovery of regional issues. In this regard, the considerations set in this paper presents a close association between the urban and the regional, having as spatial area the city of Juiz de Fora (MG), Brazil, and its area of direct influence. It is proposed to discuss the centralization and decentralization movements inter and intra urban and its implications regarding to the concentration and scattering of activities in the city in both scales. The goal is to look over the plans and projects mediated by municipal policy, sustained in public-private partnerships and supported by existing urban legislation, to respond the hypothesis: this situation has been promoting amendments in regional dynamics of Juiz de Fora while, in detriment of local needs, seeks to reaffirm the polarizing role of the municipality. The method intends to address the general, economic, political and local technical guidelines. In the present stage of development of this research, we concluded that the changes observed in the Brazilian scenario and the current economic model put an expanded list of important challenges of identifying the role of cities in the age of globalization and its new connections with the regional space.Eje 2: Forma y estructura urbana, organización del territorio, orientación del crecimiento.Facultad de Arquitectura y Urbanism

Amanita phalloides poisoning: Mechanisms of toxicity and treatment

Amanita phalloides, also known as 'death cap', is one of the most poisonous mushrooms, being involved in the majority of human fatal cases of mushroom poisoning worldwide. This species contains three main groups of toxins: amatoxins, phallotoxins, and virotoxins. From these, amatoxins, especially α-amanitin, are the main responsible for the toxic effects in humans. It is recognized that α-amanitin inhibits RNA polymerase II, causing protein deficit and ultimately cell death, although other mechanisms are thought to be involved. The liver is the main target organ of toxicity, but other organs are also affected, especially the kidneys. Intoxication symptoms usually appear after a latent period and may include gastrointestinal disorders followed by jaundice, seizures, and coma, culminating in death. Therapy consists in supportive measures, gastric decontamination, drug therapy and, ultimately, liver transplantation if clinical condition worsens. The discovery of an effective antidote is still a major unsolved issue. The present paper examines the clinical toxicology of A. phalloides, providing the currently available information on the mechanisms of toxicityinvolved and on the current knowledge on the treatment prescribed against this type of mushrooms. Antidotal perspectives will be raised as to set the pace to new and improved therapy against these mushrooms.This work was supported by the Fundação para a Ciência e Tecnologia (FCT ) – project PTDC/DTPFTO/4973/2014 – and the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through project Pest-C/EQB/LA0006/2013. Juliana Garcia and Vera Marisa Costa thank FCT for their PhD grant (SFRH/BD/74979/2010) and Post-doc grants (SFRH/BPD/63746/2009 and SFRH/BPD/110001/2015), respectively.info:eu-repo/semantics/publishedVersio

Co-ingestion of amatoxins and isoxazoles-containing mushrooms and successful treatment: A case report

Mushroom poisonings occur when ingestion of wild mushrooms containing toxins takes place, placing the consumers at life-threatening risk. In the present case report, an unusual multiple poisoning with isoxazoles- and amatoxins-containing mushrooms in a context of altered mental state and poorly controlled hypertension is presented. A 68-year-old female was presented to São João hospital (Portugal) with complaints of extreme dizziness, hallucinations, vertigo and imbalance, 3 h after consuming a stew of wild mushrooms. The first observations revealed altered mental state and elevated blood pressure. The examination of cooked mushroom fragments allowed a preliminary identification of Amanita pantherina. Gas chromatography-mass spectrometry (GC-MS) showed the presence of muscimol in urine. Moreover, through high-performance liquid chromatography-ultraviolet detection (HPLC-UV) analysis of the gastric juice, the presence of α-amanitin was found, showing that amatoxins-containing mushrooms were also included in the stew. After 4 days of supportive treatment, activated charcoal, silybin and N-acetylcysteine, the patient recovered being discharged 10 days post-ingestion with no organ complications. The prompt and appropriate therapy protocol for life-threatening amatoxins toxicity probably saved the patient's life as oral absorption was decreased and also supportive care was immediately started.This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through project Pest-C/EQB/LA0006/2013. Juliana Garcia and Vera Marisa Costa thank FCT e Foundation for Science and Technology e for their PhD grant (SFRH/BD/74979/2010) and Post-doc grant (SFRH/BPD/63746/2009), respectively.info:eu-repo/semantics/publishedVersio

[1-(3-Chloro­phen­yl)-1H-1,2,3-triazol-4-yl]methanol hemihydrate

The asymmetric unit of the title hydrate, C9H8ClN3O·0.5H2O, comprises two independent 1,2,3-triazole mol­ecules and a water mol­ecule of crystallization. The dihedral angles between the six- and five-membered rings in the 1,2,3-triazole mol­ecules are 12.71 (19) and 17.3 (2)°. The most significant different between them is found in the relative orientations of the terminal CH2OH groups with one being close to perpendicular to the five-membered ring [N—C—C—O torsion angle = 82.2 (5)°], while in the other mol­ecule, a notable deviation from a perpendicular disposition is found [torsion angle = −60.3 (5)°]. Supra­molecular chains feature in the crystal packing sustained by O—H⋯(O,N) inter­actions along the a-axis direction. The chains are connected via C—H⋯N inter­actions and the resultant layers stack along the b axis

Production of xylooligosaccharides from Brazilian Syrah grape pomace flour

BACKGROUND: The aim of this work was to determine the most favorable conditions for the production of xylooligosaccharides (XOS) from Brazilian Syrah grape pomace. Chemical processes were performed using a rotatable central composite design, where the concentration of sulfuric acid or concentration of sodium hydroxide and grape pomace flour: solvent mass ratio were the dependent variables. Enzymatic production was also evaluated using xylanase produced by Aspergillus niger 3T5B8 and Viscozyme® enzymatic commercial cocktail. RESULTS: Chemical extraction allowed to recover 21.8 to 74.6% and 5.2 to 96.3% of total XOS for acid and alkaline processes, respectively. Enzymatic production using xylanase extracted up to 88.68 ± 0.12% of total XOS and up to 84.09 ± 2.40% with Viscozyme®. CONCLUSION: The present study demonstrated different feasible methods to produce high added value molecules, the xylooligosaccharides, from Syrah grape pomace flour, valorizing this major by‐product. The use of enzymatic cocktails demonstrated to be an alternative to the conventional methods, allowing to obtain an eco‐friendly and sustainable grape pomace extract.info:eu-repo/semantics/acceptedVersio

Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs

Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential. Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection. Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs. Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs