1,842 research outputs found
Use of 3-aminotriazole to isolate oleate/acetate non-utilizing mutants of Aspergillus nidulans
Oleate non-utilizing (olu) mutants of Aspergillus nidulans were isolated on selective medium containing the catalase inhibitor, 3-aminotriazole (3-AT); in an attempt to obtain strains that would enable analysis of peroxisome biogenesis and function in filamentous fungi. Out of 816 putative mutants recovered from the selective medium, 40 were olu mutants. All of the olu mutants were unable to utilize acetate for growth, and so ressembled the acu mutants obtained by previous workers. The 40 olu mutants were placed in 5 different complementation groups
The components’ roles in thermal stability and flammability of cork powder
In this study, an analysis of the influence of extractives, suberin and lignocellulosic components on the pyrolysis decomposition and fire reaction mechanisms of a cork oak powder from Quercus suber L. is presented. The summative chemical composition of cork powder was determined. Suberin was the main component at 40% of the total weight, followed by 24% of lignin, 19% of polysaccharides and 14% of extractives. The absorbance peaks of cork and its individual components were further analyzed by means of ATR-FTIR spectrometry. Thermogravimetric analysis (TGA) showed that the removal of extractives from cork slightly increased the thermal stability between 200 °C and 300 °C and led to the formation of a more thermally stable residue at the end of the cork decomposition. Moreover, by removing suberin, a shift of the onset decomposition temperature to a lower temperature was noticed, indicating that suberin plays a major role in enhancing the thermal stability of cork. Furthermore, non-polar extractives showed the highest flammability with a peak of heat release rate (pHRR) of 365 W/g analyzed by means of micro-scale combustion calorimetry (MCC). Above 300 °C, the heat release rate (HRR) of suberin was lower than that of polysaccharides or lignin. However, below that temperature it released more flammable gases with a pHRR of 180 W/g, without significant charring ability, contrary to the mentioned components that showed lower HRR due to their prominent condensed mode of action that slowed down the mass and heat transfer processes during the combustion process.Peer ReviewedPostprint (published version
Tryptophan in the Japanese quails diets in the rearing and laying periods
Objetivou-se estudar o efeito de diferentes planos alimentares, de acordo com os nÃveis de triptofano, sobre o desempenho e estresse (pela avaliação de parâmetros fisiológicos) de codornas japonesas (Coturnix coturnix japonica) nas fases de recria e postura. Cento e noventa e duas codornas japonesas na fase de recria (30 a 44 dias de idade) foram alojadas em gaiolas e distribuÃdas em um delineamento em blocos casualizados, com quatro planos de nutrição [0,27 (controle); 0,52; 0,77 ou 1,02% de triptofano], seis repetições e oito aves por parcela. Foram avaliados os parâmetros de desempenho (consumo de ração, ganho de médio peso, conversão alimentar e taxa de mortalidade) e os parâmetros fisiológicos das aves (relação heterófilo/linfócito e concentração de corticosterona no plasma sangüÃneo). Outras 192 codornas japonesas na fase de postura (45 a 146 dias) foram distribuÃdas em delineamento de blocos ao acaso e submetidas a quatro planos de nutrição (0,23 [controle]; 0,48; 0,73 ou 0,98% de triptofano), com seis repetições e oito aves por parcela. Foram avaliados o consumo de ração, a produção de ovos, a conversão alimentar por dúzia de ovos, a taxa de mortalidade, a relação heterófilo/linfócito e a concentração de corticosterona no plasma. Os nÃveis de triptofano testados não afetaram o desempenho e os parâmetros fisiológicos de codornas japonesas nas fases de recria e postura.The effects of feeding levels of tryptophan on performance and stress of Japanese quails (Coturnix coturnix japonica) in the rearing and laying periods were evaluated. In the rearing phase, from 30 to 44 days old, 192 Japanese quails were lodged to cages and allotted to completely randomized blocks design, with four nutrition plans [0.27% (control) 0.52; 0.77 and 1.02% of tryptophan] with six replicates and eight birds per cage. Performance (feed intake, body average weight gain, feed conversion ratio), mortality rate and physiological parameters (heterophil/lymphocyte ratio) and corticosterone blood plasma were evaluated. In the lay period, another 192 Japanese quails were allotted to a completely randomized design in a four nutrition plans [0.23% (control); 0.48; 0.73 and 0.98% of tryptophan] with six replicates and eight birds per cage. Performance (feed intake, egg production, feed conversion ratio/egg dozen), mortality rate and physiological parameters (heterophil/lymphocyte ratio) and corticosterone blood plasma was evaluated. The tested tryptophan levels did not affect performance and physiological parameters of Japanese quails in the rearing and laying phases.FAPES
SÃntesi de nous compostos tipus catecol amb aplicació en materials funcionals
En el nostre grup d'investigació i en col·laboració amb el grup d'investigació del doctor Daniel Ruiz-Molina del Centre d'investigació en Nanociència i Nanotecnologia (CIN2) d'aquest campus universitari, hem iniciat un projecte que es planteja aconseguir biomimetitzar certes proteïnes adhesives de mol·luscs, en que la seva adherència es deu a la presència de la funcionalitat catecol. Aprofitant aquesta propietat adhesiva dels catecols, l'objectiu és poder desenvolupar nous materials per a recobriments hidro- i oleofòbics, i nous materials adhesius sent necessari el desenvolupament de protocols sintètics per a l'obtenció de compostos tipus catecol convenientment substituïts. En el present treball de recerca s'ha aconseguit la sÃntesi del nou catecol 10, que presenta en la seva estructura una cadena alquÃlica parcialment fluorada amb la finalitat de fer-ne recobriments hidro- i oleofòbics, i l'optimització i escalat del catecol 2, que presenta una cadena alquÃlica, amb la finalitat de fer-ne recobriments hidrofòbics. També s'ha explorat en la sÃntesi de catecols amb una funcionalitat tiol amb la finalitat de poder desenvolupar superfÃcies o nanopartÃcules d'or adhesives. Partint del producte comercial 17, s'ha aconseguit obtenir 10 en tres etapes sintètiques i un rendiment global del 57% i 2 en dues etapes sintètiques i un rendiment global del 63% a escala multigram, millorant la metodologia sintètica existent que consistia en quatre etapes sintètiques i un 48% de rendiment global
Avaliação gap óptico do TiO2 obtido pelo método Pechini: influência da variação das fases anatásio-rutilo
 Neste trabalho foi sintetizado TiO2 pelo método Pechini em diferentes proporções de ácido cÃtrico/cátions metálicos visando avaliar a influência das fases anatásio e rutilo na estrutura, morfologia e gap óptico de energia. Dessa forma, as amostras foram caracterizadas por DRX, FTIR, distribuição e tamanho de aglome-rados, densidade por picnometria de hélio, TGA e determinação de banda gap a partir da refletância difusa. Os resultados mostram a formação das fases anatásio e rutilo em todas as proporções de ácido cÃtrico/cátions metálicos avaliadas. Morfologicamente as amostras apresentaram tamanho de aglomerados entre 15,89 a 19,34 μm com densidade em torno de 3,7 g/cm3. Com relação à s propriedades ópticas avaliadas observou-se que o aumento da proporção da fase rutilo em relação à fase anatásio não alterou significativamente sua ban-da gap, obtendo-se valores entre 2,97 a 3,00 eV.Palavras-Chave: TiO2, método Pechini; gap óptico, anatásio-rutilo
Arming Oncolytic Adenoviruses: Effect of Insertion Site and Splice Acceptor on Transgene Expression and Viral Fitness
Oncolytic adenoviruses (OAds) present limited efficacy in clinics. The insertion of therapeutic transgenes into OAds genomes, known as "arming OAds", has been the main strategy to improve their therapeutic potential. Different approaches were published in the decade of the 2000s, but with few comparisons. Most armed OAds have complete or partial E3 deletions, leading to a shorter half-life in vivo. We generated E3+ OAds using two insertion sites, After-fiber and After-E4, and two different splice acceptors linked to the major late promoter, either the Ad5 protein IIIa acceptor (IIIaSA) or the Ad40 long fiber acceptor (40SA). The highest transgene levels were obtained with the After-fiber location and 40SA. However, the set of codons of the transgene affected viral fitness, highlighting the relevance of transgene codon usage when arming OAds using the major late promoter
Liver transplantation in metastatic colorectal cancer: are we ready for it?
Liver transplantation; Metastatic colorectal cancerTrasplantament de fetge; Cà ncer colorectal metastà ticTrasplante de hÃgado; Cáncer colorrectal metastásicoColorectal cancer (CRC) is a prevalent disease worldwide, with more than 50% of patients developing metastases to the liver. Five-year overall survival remains modest among patients with metastatic CRC (mCRC) treated with conventional therapies however, liver transplantation in a highly selected population can improve clinical outcomes with an impressive 5-year overall survival of 83%. Despite liver transplantation appearing to be a promising therapeutical option for well-selected patients with mCRC with the liver-limited disease, these data come from small monocentric trials which included a heterogeneous population. Currently, several clinical trials are evaluating liver transplantation in this scenario, aiming for a more accurate patient selection by integrating liquid biopsy, tissue profiling, and nuclear medicine to the already known clinical biomarkers that eventually may lead to a survival improvement. In this paper, the clinical outcomes and inclusion criteria from the most relevant clinical trials and clinical series involving liver transplantation in patients with liver-limited disease colorectal cancer are reviewed as well as the trials currently recruiting
The Expression of TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Can Be Controlled by the Antioxidant Orchestrator NRF2 in Human Carcinoma Cells
Hyperactivation of the KEAP1-NRF2 axis is a common molecular trait in carcinomas from different origin. The transcriptional program induced by NRF2 involves antioxidant and metabolic genes that render cancer cells more capable of dealing with oxidative stress. The TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) is an important regulator of glycolysis and the pentose phosphate pathway that was described as a p53 response gene, yet TIGAR expression is detected in p53-null tumors. In this study we investigated the role of NRF2 in the regulation of TIGAR in human carcinoma cell lines. Exposure of carcinoma cells to electrophilic molecules or overexpression of NRF2 significantly increased expression of TIGAR, in parallel to the known NRF2 target genes NQO1 and G6PD. The same was observed in TP53KO cells, indicating that NRF2-mediated regulation of TIGAR is p53-independent. Accordingly, downregulation of NRF2 decreased the expression of TIGAR in carcinoma cell lines from different origin. As NRF2 is essential in the bone, we used mouse primary osteoblasts to corroborate our findings. The antioxidant response elements for NRF2 binding to the promoter of human and mouse TIGAR were described. This study provides the first evidence that NRF2 controls the expression of TIGAR at the transcriptional level
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