71 research outputs found

    Incorporation of an acrylic fatty acid derivative as comonomer for oxidative cure in acrylic latex

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    An acrylic fatty acid derivative (AcFAD) was evaluated as comonomer for promotion of oxidative cure in waterborne latexes. AcFAD was polymerized by solvent homopolymerization and copolymerization and by emulsion copolymerization, and the final products characterized. In the two polymerization processes, NMR analyses confirmed that the reaction occurred involving both the terminal acrylic double bond and the conjugated double bonds of the aliphatic chain. Compared with a reference acrylic latex, the results obtained after AcFAD incorporation showed a time-dependent increase in gel content and in solvent resistance of dry films. These were ascribed to oxidative cure and consequent self-crosslinking of the acrylic polymer, involving the conjugated double bonds in AcFAD side chains. Oxidative cure was also confirmed by FTIR analyses. In addition, reduction in minimum film-forming temperature evidenced that AcFAD has an internal plasticization effect during film formation. Incorporation of this comonomer in acrylic paint binder formulations constitutes a promising alternative to the use of volatile coalescing agents

    New insights into a bacterial metabolic and detoxifying association responsible for the mineralization of the thiocarbamate herbicide molinate

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    A novel pathway of molinate mineralization promoted by a defined mixed culture composed of five bacteria (named ON1 to ON5) was proposed previously. Evidence was obtained of a metabolic association between Gulosibacter molinativorax ON4T, capable of molinate breakdown, and the remaining bacteria. In the present study, the role of each isolate in that metabolic association was further explored and the possible synergistic effect of all the bacterial isolates for the stability of the mixed culture is discussed. The cleavage of the molinate thioester bond, whether occurring under aerobic or anaerobic conditions, releases ethanethiol (S-ethyl moiety) and an azepane moiety derivative, identified as azepane-1-carboxylic acid. This azepane moiety is degraded, in the presence of oxygen, by Pseudomonas strains ON1 and ON3 and G. molinativorax ON4T. Ethanethiol, which inhibits G. molinativorax ON4T, is consumed by Pseudomonas strain ON1 and Stenotrophomonas maltophilia ON2. Although a two-member mixed culture of G. molinativorax ON4T and Pseudomonas strain ON1 was able to promote the aerobic mineralization of molinate, after 20 successive transfers of the five-member mixed culture in mineral medium with molinate, none of these isolates were lost. The results obtained indicate that the whole mixed culture may have a higher fitness than the two-member culture, even when the basic degradative and cross-protection functions are assured

    MicroRNA-21 expression and susceptibility to HPV-induced carcinogenesis - role of microenvironment in K14-HPV16 mice model

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    Aims: Human papillomaviruses (HPVs) are responsible for several types of cancer. K14-HPV16 transgenic mice express the HPV16 early genes, developing multi-step carcinogenesis associated with marked inflammation, as observed in human patients. MicroRNAs (MiRNA) constitute a class of non-coding RNAs that regulate gene expression. In particular, miR-21 has been associated with carcinogenesis. However, little is known about this microRNA in the normal tissue microenvironment and its possible relationship with cancer predisposition. We hypothesized that miR-21 expression influences each tissue's susceptibility to HPV-induced carcinogenesis. Main methods: In order to test this hypothesis, we evaluated miR-21 expression by RT-qPCR in ear and chest skin samples from 24-28 weeks old, female K14-HPV16 transgenic and wild-type mice. Key findings: In wild-type mice (HPV-/-) miR-21 expression was lower in ear skin compared with that of chest skin (p = 0.036). Under the influence of HPV16 oncogenes, transgenic animals (HPV16+/-), developed in situ carcinoma in all ear samples and epidermal hyperplasia in chest samples. These results are consistent with the hypothesis that microRNA expression in the microenvironment of normal tissues may influence HPV-associated carcinogenesis. Furthermore, among transgenic animals, miR-21 expression was lower in in situ carcinoma samples compared with hyperplasia (p = 0043). Significance: This suggests that, despite the well-known role of miR-21 as an oncogene, its anti-inflammatory and immunomodulatory properties may modulate HPV-induced carcinogenesis in a tissue-dependent manner. Further studies are warranted in order to explore the role of microRNAs in tissue susceptibility to carcinogenesis

    Novel approach for a controlled delivery of essential Oils during long-term maize storage: clove bud and pennyroyal oils efficacy to control sitophilus zeamais, reducing grain damage and post-harvest losses

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    Maize grains represent a significant contribution for assuring food safety all over the globe. Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), also known as the maize weevil, is one of the most destructive pests in stored maize, causing qualitative and quantitative losses. To control S. zeamais populations in maize storage sites, synthetical chemical insecticides are applied. However, these are often used wastefully, have environmental implications, and can induce the development of resistant populations. In this work, the insecticidal and grain protecting efficacy of an innovative macro-capsule delivery device, loaded with essential oils from Clove bud and Pennyroyal, as well as their combined solutions, was tested against naturally S. zeamais-infested maize grains. The blend of both compounds incorporated in a controlled release device reduced losses by more than 45% over a long storage period of twenty weeks, diminishing the survivability of maize weevils by over 90%. The usage of the blend at a concentration of 370 L L1 air with an antioxidant showed the best results, however, by halving the concentration 185 L L1 air , a significant control of S. zeamais populations was still achieved.info:eu-repo/semantics/publishedVersio

    Preparation of robust polyamide microcapsules by interfacial polycondensation of p-phenylenediamine and sebacoyl chloride and plasticization with oleic acid

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    Microcapsules produced by interfacial polycondensation of p-phenylenediamine (PPD) and sebacoyl chloride (SC) were studied. The products were characterized in terms of morphology, mean diameter and effectiveness of dodecane encapsulation. The use of Tween 20 as dispersion stabilizer, in comparison with polyvinyl alcohol (PVA), reduced considerably the mean diameter of the microcapsules and originated smoother wall surfaces. When compared to ethylenediamine (EDA), microcapsules produced with PPD monomer were more rigid and brittle, prone to fracture during processing and ineffective retention of the core liquid. The use of diethylenetriamine (DETA) cross-linker in combination with PPD did not decrease capsule fragility. On the other hand, addition of a small fraction of oleic acid to the organic phase remarkably improved wall toughness and lead to successful encapsulation of the core-oil. Oleic acid is believed to act as a plasticizer. Its incorporation in the polymeric wall was demonstrated by FTIR and (1)H-NMR.This work was funded by FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE), ON.2 – O Novo Norte – North Portugal Regional Operational Programme and National Funds through Foundation for Science and Technology (FCT) under the projects: PEst-C/EQB/UI0511, NORTE-07-0124-FEDER-000026 – RL1_ Energy and PTDC/CTM-NAN/119979/2010. The Bruker Avance III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment, REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). Joana R. Góis acknowledges FCT-MCTES for her PhD scholarship (SFRH/BD/69635/2010)

    Pulegone and Eugenol Oral Supplementation in Laboratory Animals: Results from Acute and Chronic Studies

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    Essential oils are natural compounds used by humans for scientific purposes due to their wide range of properties. Eugenol is mostly present in clove oil, while pulegone is the main constituent of pennyroyal oil. To guarantee the safe use of eugenol and pulegone for both humans and animals, this study addressed, for the first time, the effects of these compounds, at low doses (chronic toxicity) and high doses (acute toxicity), in laboratory animals. Thirty-five FVB/n female mice were randomly assigned to seven groups (n = 5): group I (control, non-additive diet); group II (2.6 mg of eugenol + 2.6 mg of pulegone); group III (5.2 mg of eugenol + 5.2 mg of pulegone); group IV (7.8 mg of eugenol + 7.8 mg of pulegone); group V (7.8 mg of eugenol); group VI (7.8 mg of pulegone); and group VII (1000 mg of eugenol + 1000 mg of pulegone). The compounds were administered in the food. Groups I to VI were integrated into the chronic toxicity study, lasting 28 days, and group VII was used in the acute toxicity study, lasting 7 days. Animals were monitored to assess their general welfare. Water and food intake, as well as body weight, were recorded. On the 29th day, all animals were euthanized by an overdose of ketamine and xylazine, and a complete necropsy was performed. Blood samples were collected directly from the heart for microhematocrit and serum analysis, as well as for comet assay. Organs were collected, weighed, and fixed in formaldehyde for further histological analysis and enzymatic assay. Eugenol and pulegone induced behavioral changes in the animals, namely in the posture, hair appearance and grooming, and in mental status. These compounds also caused a decrease in the animals' body weight, as well as in the food and water consumption. A mortality rate of 20% was registered in the acute toxicity group. Both compounds modulated the serum levels of triglycerides and alanine aminotransferase. Eugenol and pulegone induced genetic damage in all animals. Eugenol increased the activity of the CAT enzyme. Both compounds increased the GR enzyme at the highest dose. Moreover, pulegone administered as a single compound increased the activity of the GST enzyme. Histopathological analysis revealed inflammatory infiltrates in the lungs of groups II, III, and IV. The results suggest that eugenol and pulegone may exert beneficial or harmful effects, depending on the dose, and if applied alone or in combination

    Učinci ekstrakta Cytinus hypocistis (L.) L. u životinjskom modelu neoplazije inducirane papiloma virusom

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    Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeutic compounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals, 30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/n+CH12.4); V (HPV+control) and VI (FVB/n+-control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.Infekcije određenim vrstama papiloma virusa, poput humanog papiloma virusa 16 (HPV16), povezane su s razvojem preneoplastičnih lezija i karcinoma anogenitalnog područja i područja glave i vrata. Ekstrakti Cytinus hypocistis (CH) sadrže tvari koje pokazuju antiproliferativna, antioksidativna, protuupalna i antibakterijska svojstva te bi stoga mogle predstavljati nove, obećavajuće terapijske spojeve. Cilj je ovog rada bio analizirati utjecaj topikalne primjene ekstrakta dobivenog iz C. hypocistis (L.) L. na K14-HPV16 i FVB/n miševima za procjenu njegovih terapijskih i toksikoloških svojstava. Za postizanje ciljeva istraživanja, trideset ženki miševa starosti 33-37 tjedana podijeljeno je u šest skupina (n=5/ skupini): I (HPV+CH3,1); II (HPV+CH6,2); III (HPV+CH12,4); IV (FVB/n+CH12,4); V (HPV+kontrola) i VI (FVB/n+kontrola). CH je tijekom 28 dana topikalno primijenjen na oba uha. Nakon tog razdoblja sve životinje su žrtvovane u svrhu prikupljanja rezulata. Lezije kože su histološki klasificirane. Toksikološki parametri uključivali su hematološke i biokemijske markere krvi te analizu oksidativnog stresa jetre. Transgenične životinje pokazale su smanjenje srednje tjelesne mase, bez obzira na primijenjenu koncentraciju ekstrakta. Ekstrakt nije utjecao na fiziološke parametre, masu organa ili parametre biokemijskog i oksidativnog stresa. Histološki je dokazana prisutnost proliferativnih epitelnih lezija na koži i oralnoj sluznici K14-HPV16 miševa, bez povezanosti s primjenom ovog ekstrakta. Općenito, primjena CH ekstrakta nije utjecala na lezije kože te su ga životinje dobro podnosile u primijenjenim koncentracijama

    Bio-based solar energy harvesting for onsite mobile optical temperature sensing in Smart Cities

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    The Internet of Things (IoT) fosters the development of smart city systems for sustainable living and increases comfort for people. One of the current challenges for sustainable buildings is the optimization of energy management. Temperature monitoring in buildings is of prime importance, as heating account for a great part of the total energy consumption. Here, a solar optical temperature sensor is presented with a thermal sensitivity of up to 1.23% °C-1 based on sustainable aqueous solutions of enhanced green fluorescent protein and C-phycocyanin from biological feedstocks. These photonic sensors are presented under the configuration of luminescent solar concentrators widely proposed as a solution to integrate energy-generating devices in buildings, as windows or façades. The developed mobile sensor is inserted in IoT context through the development of a self-powered system able to measure, record, and send data to a user-friendly website.publishe

    Aloysia citrodora extract as a chemopreventive agent against HPV16-induced lesions: findings from K14-HPV16 mice

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    Aim: Aloysia citrodora has a long history of traditional use in treating various ailments. This study evaluated the in vivo chemopreventive efficacy and systemic toxicity of an extract of A. citrodora in a transgenic mouse model of HPV16 (human papillomavirus type 16)-induced cancer. Methods: The experiment involved six groups (n = 5): group 1 (G1, wild-type (WT), water), group 2 (G2, HPV, water), group 3 (G3, WT, 0.013 g/mL), group 4 (G4, HPV, 0.006 g/mL), group 5 (G5, HPV, 0.008 g/mL), and group 6 (G6, HPV, 0.013 g/mL). Throughout the assay, humane endpoints, body weight, food, and water consumption were recorded weekly. The internal organs and skin of the mice were collected for analysis after they were sacrificed. Toxicological parameters that were studied included hematological and biochemical blood markers, splenic and hepatic histology, and hepatic oxidative stress. Results: A. citrodora extract seems to reduce the incidence of dysplastic and in situ carcinoma skin lesions induced by HPV16 in this model, suggesting that dietary supplementation with concentrations of 0.008 g/mL and 0.013 g/mL may have beneficial chemopreventive effects. Conclusions: The extract did not induce any concentration-dependent toxicological effects on any of the parameters included in the study, indicating a favorable toxicological profile under these experimental conditions.info:eu-repo/semantics/publishedVersio

    A complex scenario of tuberculosis transmission is revealed through genetic and epidemiological surveys in Porto

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    Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases.This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and supported by contributions from Iceland, Liechtenstein and Norway through the European Economic Area Grants under the Public Health Initiative programme, (PT06, Project 000138DT1). TR is supported by the Portuguese Foundation for Science and Technology (FCT) through a post-doctoral grant (SFRH/BPD/108126/2015)info:eu-repo/semantics/publishedVersio
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