A concise synthesis of carbasugars isolated from Streptomyces lincolnensis

(–)-Quinic acid was used as a starting material in the hemisynthesis of two epimeric carbasugars isolated from Streptomyces lincolnensis. Previous 10–12 steps syntheses for the carbasugars have been herein shortened to 4–6 steps by using quinic acid as a chiron, based on a regioselective reduction step, with stereoinversion of a tertiary center. Both C-5 epimers of (1R, 2R, 3R)-5-(hydroxymethyl)cyclohexane-1,2,3-triol were obtained in up to 76% overall yield.publishe

Saccharomyces cerevisiae UE-ME3 is a good strain for isoproturon biorremediation?

Isoproturon, an herbicide of pre- and pos-emergence of Autumn-Winter crops, persists occasionally in soil, groundwater and biological systems at levels above those established by European Directives. Saccharomyces cerevisiae UE-ME3 exposed in stationary phase to 50 and 100 mM isoproturon exhibit growth rates higher than control or exposed cells to 5 and 25 mM of this phenylurea. However, in S.cerevisiae UE-ME3 grown in the presence of 5 mM isoproturon, were observed a decrease of GSH/GSSG ratio, an increase of cytoplasmatic MDA level, GR and GPx activities, usual markers of cell damage and oxidative stress. Nevertheless, S.cerevisiae grown at 25, 50 and 100 mM isoproturon, have developed adaptive responses to this phenylurea by stabilization of its reducing environment, lipid peroxidation decrease and GR, GPx activities increase, events regulated by isoproturon level in culture medium, facts which suggest that this yeast strain can be useful on bioremediation

MATERIAL CHARACTERISATION OF A FLORENTINE PAINTER IN PORTUGAL IN THE LATE 19TH CENTURY: PAINTINGS BY GIORGIO MARINI

This paper presents the analytical characterisation of a series of paintings authored by Giorgio Marini (1836-1905) from the Museum of Évora. Marini was an Italian painter who lived in Portugal in the 19th century. He was a very prolific painter and his works, most of them portraits commissioned by urban and rural bourgeois and noble elites, are dispersed all over the country. The general good conservation state of most paintings prevented the collection of micro-samples for detailed study. Hence, material identification of the painting materials was performed primarily by XRF, given its non-destructive and non-invasive nature, and it was complemented when possible by auxiliary techniques optical microscopy, Raman spectroscopy, and SEM-EDX. Pigments and fillers such as yellow and red ochre, lead white, zinc white, barium white, chrome yellow and green chrome are among the identified pigments. This is the first time the palette used by Giorgio Marini was identified, helping to characterised the pigments used by foreign painters during the 19th century in Portuga

Comparative study of toxicological effects of lindane and isoproturon pesticides in the Saccharomyces cerevisiae

Organochlorine insecticides and phenylurea herbicides such as lindane (hexachlorocyclo-hexane, γ-HCH) and isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea, IPU), used in agricultural applications for the pest and broad-leaved control, are often found in contaminated groundwater and surface water. Unfortunately, the toxicity of these pesticides in eukaryotic cells is still poorly understood. Saccharomyces cerevisiae is a promising eukaryotic organism for the toxicological evaluation of pollutants, because its metabolism is similar to that of high-level organisms. Thus the aim of this study was to compare the effects of two pesticides on yeast-cell viability and its antioxidant power. S. cerevisiae UE-ME3, a wild-type strain belonging to Oenology Laboratory of the University of Évora, grown in the presence of 50 μM γ-HCH and 100 μM IPU in 2% glucose and peptone deprivation medium (YED), at 28 °C were compared with control cells. CFU were determined at the end of the experiment and remaining cells disintegrated in 10 mM phosphate buffer pH 7.0 by sonication. Post-12,000 × g supernatant was used for determination of glutathione (GSH), glutathione disulphide (GSSG) and malondialdehyde (MDA) content and glutathione reductase (GR), glutathione peroxidase (GPx) and cytoplasmic catalase (CTT1) activity. The results showed that 50 μM γ-HCH exposures, in YED medium, did not affect cell viability, CTT1 activity, non-protein thiols (GSH + GSSG) and MDA content of S. cerevisiae. However, the 50 μM γ-HCH exposure caused a decrease in GSH/GSSG ratio, GR and GPx activity. In contrast, 100 μM IPU exposures caused an increase in the cell viability, (GSH + GSSG), GSH/GSSG ratio and GR activity. Additionally, there was a decrease in the MDA levels, GPx and CTT1 activity, under the same growth conditions. In conclusion, the presence of lindane, in YED medium, caused a reducing-oxidizing transition, a slowdown of the glutathione redox cycle without disturbing the survival of S. cerevisiae. However, the increase in the cell viability, the redox buffer power and the lipid peroxidation attenuation caused by IPU in nitrogen deprivation, appears to be due to the high regeneration capacity of GSH via GR activity, pointing out a possible use of isoproturon as nitrogen source

Lemierre Syndrome in a Teenager Presenting as Pulmonary Septic Embolism

Lemierre syndrome is easily missed and may be more common than generally believed. Usually a complication of a deep neck abscess, it can present suddenly with shortness of breath and hypoxemia. Accurate diagnosis and orientation are mandatory for the treatment of an otherwise potentially life-threatening disease. We describe a case of an adolescent with Lemierre syndrome and septic pulmonary embolism.info:eu-repo/semantics/publishedVersio

Nanoconsolidants for lime mortars of wall paintings as a good alternative of traditional consolidants

Carbonate stones and wall paintings, as an irremovable part of the architectural heritage, are subject to constant attack by soluble salts and pollutants. They can undergo different kinds of degradation, including corrosion by acid rain, physical erosion, cycles of salts crystallization/solubilization and biodegradation due to bacteria, fungi or lichens. Often, past treatments tend to cause additional substrate damages. For instances, synthetic polymeric materials applied for work of art restoration as consolidants, protectives, adhesives or cleaning agents, initially were seen as a good treatment alternative. However, upon ageing they are subject to degradation which results in cross-linking or chain scission which consequently alter their own initial properties and accelerate the decay of the artwork by changing its physicochemical properties. Nanoconsolidants exhibit distinct properties when compared to their bulk analogues, and for the last decade have been seen as a good alternative of compatible materials for long term preservation of Cultural Heritage.[1,2] A highly efficient consolidant for stone or mortar must meet a large list of requisites: must be effective for long-term, be compatible with the damaged substrate, to induce mechanical improvement and protection from weathering to the material, among others. The application of micro- and nanoparticles (NPs) based on alkali-earth metal hydroxides for cultural heritage conservation has become more relevant, mainly for consolidation of historic lime mortars, biocalcarenite stone and for cellulose materials deacidification purposes. Our research intends to propose successful preparative strategies of sub-micro and nanolimes, and to study their efficiency in the inhibition of the degradation process and in the consolidation of wall renders. In this communication an overview of the main synthesis strategies to prepare nanoconsolidants for restoration of Cultural Heritage is carried out. We also report our attempts to develop nanoconsolidants based on alkali-earth metal hydroxides for lime mortars of wall paintings. Furthermore, we discuss their effectiveness for the improvement of the mechanical properties of lime mortars. [1] Baglioni, P.; Carretti, E.; Chelazzi, D., Nature Nanotechnology 2015, 10, 287. [2] Girginova, P. I.; Galacho, C.; Veiga, R.; Santos Silva, A.; Candeias, A., ChemSusChem 2018, 11, 4168.Post-doctoral grant (P.G.) SFRH/BPD/97692/201

Historic Appraisal Review and Geometric Characterization of Old Masonry Buildings in Lisbon for Seismic Risk Assessment

The Metropolitan Area of Lisbon (MAL) has the highest population and building density in Portugal, and is exposed to medium to high magnitude earthquakes due to its geographical location. Currently, the MAL housing stock is constituted by approximately 35% of masonry residential buildings with a large variability of materials and construction techniques, as a result of many centuries of history. Most of these buildings were built before the introduction of the first design code for building safety against earthquakes (RSSCS) in Citation1958 and therefore were only designed to support gravity loads. Given the presence of these buildings in areas of significant seismicity, a comprehensive research is needed to assess the seismic risk and define mitigation policies for this population of unreinforced masonry buildings. The main purpose of this work is thus to geometrically characterize these typologies, through an exhaustive survey of dozens of masonry buildings collected from original drawings and identify the most important aspects that can influence their seismic behavior. After a compressive historical background, the information collected is statistically analyzed and expressed through probability distributions that can be used for the development of numerical models and derive seismic vulnerability functions, fundamental to conduct seismic risk analyses.info:eu-repo/semantics/publishedVersio

Prevalence of antibodies to the BK and JC papovaviruses in isolated populations

A total of 173 sera from isolated Brazilian Indian populations, 39 from the Diauarun area, and 68 from the Alto Xingú area, respectively in the North and the South of the Xingú National Park and 66 Kren-Akorore Indians, were examined for hemagglutination - inhibiting (HI) antibodies against BK and JC viruses. The global percentages of positive sera (;>;; 1:40) were 5.2% for BK virus and 1.7% for JC virus. The distribution of positive sera according to the population groups showed one individual to be positive for BK virus in the Diauarun Indians and none of the sera contained HI antibody to JC virus; in the Alto Xingú Indians, 4 were positive for BK virus and 3 others were positive for JC virus; as regards Kren-Akorore Indians none of the sera contained antibody to JC virus, and only 4 were BK positive. Due to the limited number of observations it was neither possible to determine the time of occurrence of seroconversion nor correlate the positivity rates for both viruses in the different tribes with the respective "contact" with the white population.Foram estudados 173 soros de índios brasileiros, sendo 39 da área Diauarum, 68 do Alto Xingú e 66 índios Kren-Akorore. A pesquisa de anticorpos inibidores da hemaglutinação para os papovavirus BK e JC mostrou uma percentagem global de positividade (;>;; 40) para os virus BK de 5,2% e para o virus JC de 1,7%. A distribuição dos soros positivos segundo sua origem foi a seguinte: dos 39 índios Diauarum somente um apresentou titulo significante para o virus BK e nenhum deles foi positivo para o virus JC; dos 68 índios do Alto Xingú, 4 apresentaram título significante para o virus BK e 3 para o virus JC, sendo estes últimos diferentes dos indivíduos positivos para o virus BK; dos 66 índios Kren-Akorore, 4 mostraram possuir título significante para o virus BK, sem positividade para o virus JC. O número reduzido de soros não permitiu estabelecer o momento da ser o conservação, em termos de idade, como não permitiu relacionar as taxas de positividade com o maior ou menor "contato" com a população branca

Micro- and nanoparticles based on alkali-earth metal hydroxides for cultural heritage conservation

Wall renders are subject of constant aging and deterioration and they therefore need repair and treatment. The polymers used in the past for consolidation show many drawbacks and often accelerate the deterioration. This implies the need of new non-toxic materials, preferably of the same composition as the original art work, compatible, with long-term efficiency, without side effect, easy for application. Different inorganic materials have been proposed. The lime-based materials are convenient but not efficient enough, so that different approaches to enhance their efficiency must be found. Nanomaterials exhibit distinct properties when compared to their bulk analogues and have been seen as a good alternative of compatible materials for long term preservation [1]. In this context our research intends to study and optimize successful preparative strategies of micro- and nanolimes, and to improve their efficiency in the inhibition of the degradation process and in the consolidation of wall renders and stone [2,3]. The work is focused on the innovation of the tradition lime materials towards long-term efficiency and compatibility with the surfaces of original works, taking into account environmental and human risk factors. In this communication we report the synthesis and characterization of micro- and nanoparticles based on alkali-earth metal hydroxides for cultural heritage conservation. We discuss synthetic strategies applied and optimum preparative conditions, such as temperature, synthesis duration, addition of surfactant and others, in order to obtain well defined functional magnesium and calcium hydroxides nanoparticles. The composition, morphology and crystallinity are analysed mainly by microscopical techniques and by X-ray powder diffraction. Additional structural and chemical data are collected with other common techniques: Energy Dispersive X-Ray Spectrometry, micro-FTIR, micro-Raman, simultaneous thermal analysis (TGA/DTA) among others, when needed. We also discuss the laboratory tests conducted to assess the efficiency of the nanolimes on mortar specimens (porosity, dynamic elastic modulus, compressive and flexural mechanical behaviour) and the feasibility of their application. References: [1] Baglioni P., Carretti E., Chelazzi D., Nature Nanotechnology 10, Apr 2015, 287-290. [2] Girginova, P.I.; Galacho, C.; Mirão, J.; Veiga, R.; Silva, A.S.; Candeias, A., Conservar património 23, 2016, 103-107. [3] Borsoi, G.; Lubellia, B.; van Hees, R.; Veiga, R.; Silva, A.S.; J. Cult Herit. 18, 2016, 242

Simulation of Wind-Induced Flow and Transport in a Brazilian Bay

Experimental and Computational Hydraulic