Effect of the agitation on the adsorption and hydrolytic efficiency of cutinases on polyethylene terephthalate fibres

The effect of agitation on adsorption, desorption and hydrolytic efficiency of a native and a genetically modified cutinase (L182A) on polyethylene terephthalate fibres is reported in this paper. The effect of mechanical agitation was studied using a shaker bath with orbital agitation and a Rotawash machine with vertical agitation with and without extra steel discs inside the reaction pots. The results obtained indicate that mechanical agitation combined with enzymatic action enhances the adsorption and activity of cutinases towards PET (polyethylene terephthalate) fibres. L182A showed higher adsorption than the native enzyme for all the levels of mechanical agitation. Lower units of L182A lead to similar yields of terephthalic acid formed in all levels of mechanical agitation. The highest increase of hydroxyl surface groups was found for the genetically modified L182A at the lowest level of mechanical agitation with a shaker bath. These results indicate that enzymatic functionalization of PET is favoured with a process with lower levels of mechanical agitation

Methodology for hubs placement analysis: an application to Portuguese industrial CO₂ emissions

Carbon capture and Geological storage (CCGS) is recognised as a technology capable of reducing large-scale emissions of carbon dioxide (CO2), which is an important part of the portfolio of alternatives necessary to achieve significant reductions in the global emissions of greenhouse gases (GHG). As of this context where greenhouses gases constrains in Europe would come, and CCGS would be a mitigation option for GHG, it becomes necessary to develop a CO2 transport network to collect and inject it in a proper geological reservoir. Therefore, the following methodology can help to implement a pipeline network in any region in the world by doing a preliminary analysis about the best places to locate a HUB (temporary CO2 reservoir). In this paper, the demonstration of the methodology refers to Portugal’s industrial emission sources in which CCS could be implemented.This research was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013612263)

Understanding cost escalation in nuclear reactor construction projects

This work seeks to evaluate overnight construction costs (OCC) and lead time escalation of nuclear reactors from 1955 to 2016. To this end, a comprehensive database of commercial Light Water Reactors (LWR) was developed and a statistical analysis was conducted. Findings reveal that there is significant delay in lead time, especially for the last generation reactors constructed from 2010’s. This results in the escalation of capital costs rather than a decline. Average OCC of newer reactors are 60% higher than the ones implemented in the earlier stages of the nuclear era. This suggests a negative learning curve effect for both OCC and lead time, which threats the market and financial sustainability of current and future nuclear energy projects. Although this is a general trend, this negative effect is country specific and, thus, induced by national policies and regulatory frameworks. Therefore, the role of nuclear technology to cope with the decarbonisation of the power sector must be better evaluated, taking into account the real cost impacts of nuclear technology implementation.This work was also funded by the Brazilian research funding agency CNPq.This work was funded by the Brazilian research funding agency CNPq and the Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under the project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263)

CD47 expression is decreased in hematopoietic progenitor cells in patients with myelofibrosis

Myelofibrosis (MF) is characterized by increased circulating hematopoietic progenitor cells (HPCs), abnormal cytokine levels, and the survival advantage of neoplastic progenitors over their normal counterparts, which leads to progressive disappearance of polyclonal hematopoiesis. CD47 is a surface glycoprotein with many functions, such as acting as a phagocytosis inhibitor of the expressing cell, that is increased in normal hematopoietic stem and progenitor cells mobilized into the blood and several human cancer-initiating cells, such as in acute myeloid leukemia. We compared CD47 expression in hematopoietic stem and progenitor cells of patients with MF and controls and found it to be decreased in progenitors of MF. Exposure of control HPCs to the cytokines transforming growth factor β and stromal-derived factor 1, which are important regulators of hematopoietic stem cell cycling and are overexpressed in patients with MF, did not modulate CD47 expression

Tailoring cutinase activity towards polyethylene terephthalate and polyamide 6,6 fibers

Cutinase from Fusarium solani pisi was genetically modified near the active site, by site-directed mutagenesis, to enhance its activity towards polyethylene terephthalate (PET) and polyamide 6,6 (PA 6,6) fibers. The mutations L81A, N84A, L182A, V184A and L189A were done to enlarge the active site in order to better fit a larger polymer chain. Modeling studies have shown enhanced free energy stabilization of model substrate tetrahedral intermediate (TI) bound at the enzyme active site for all mutants, for both model polymers. L81A and L182A showed an activity increase of four- and five-fold, respectively, when compared with the wild type, for PET fibers. L182A showed the one- and two-fold higher ability to biodegrade aliphatic polyamide substrates. Further studies in aliphatic polyesters seem to indicate that cutinase has higher ability to recognize aliphatic substrates.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/22490/2005, SFRH/BD/22149/2005European Community - Biosyntex Project, no. G5RD-CT-2000-30110 “Competitive and Sustainable Growth

Bacteriocin production by Escherichia coli during biofilm development

Escherichia coli is a highly versatile bacterium ranging from commensal to intestinal pathogen, and is an important foodborne pathogen. E. coli species are able to prosper in multispecies biofilms and secrete bacteriocins that are only toxic to species/strains closely related to the producer strain. In this study, 20 distinct E. coli strains were characterized for several properties that confer competitive advantages against closer microorganisms by assessing the biofilm-forming capacity, the production of antimicrobial molecules, and the production of siderophores. Furthermore, primer sets for E. coli bacteriocins–colicins were designed and genes were amplified, allowing us to observe that colicins were widely distributed among the pathogenic E. coli strains. Their production in the planktonic phase or single-species biofilms was uncommon. Only two E. coli strains out of nine biofilm-forming were able to inhibit the growth of other E. coli strains. There is evidence of larger amounts of colicin being produced in the late stages of E. coli biofilm growth. The decrease in bacterial biomass after 12 h of incubation indicates active type I colicin production, whose release normally requires E. coli cell lysis. Almost all E. coli strains were siderophore-producing, which may be related to the resistance to colicin as these two molecules may use the same transporter system. Moreover, E. coli CECT 504 was able to coexist with Salmonella enterica in dual-species biofilms, but Shigella dysenteriae was selectively excluded, correlating with high expression levels of colicin (E, B, and M) genes observed by real-time PCR.info:eu-repo/semantics/publishedVersio

Mental health problems and smoking among adolescents from Southern Brazil

OBJECTIVE: To analyze the association between mental health problems and smoking in adolescents. METHODS: A total of 4,325 adolescents aged 15 from the 1993 birth cohort of the city of Pelotas, Southern Brazil, was studied. Smoking was defined as having smoked one or more cigarettes in the previous 30 days. Mental health was assessed according to the total score of the Strengths and Difficulties Questionnaire. Score >; 20 points was considered positive. Data were analyzed using Poisson regression with adjustment for robust variance. RESULTS: Smoking prevalence was 6.0% and about 30% of the adolescents presented some mental health problem. In the crude analysis, the prevalence ratio for smoking was 3.3 (95%CI 2.5; 4.2). After the adjusted analysis (for sex, age, skin color, family income, mother's level of schooling, group of friends who smoke, employment in the previous year, school failure, physical activity during leisure time and experimental use of alcohol), it decreased to 1.7 (95%CI 1.2; 2.3) among those with mental health problem. CONCLUSIONS: Mental health problems in adolescence may be related to tobacco consumption.OBJETIVO: Analisar a associação entre problemas de saúde mental e uso de tabaco em adolescentes. MÉTODOS: Foram analisados 4.325 adolescentes de 15 anos da coorte de nascimentos de 1993 da cidade de Pelotas, RS. Tabagismo foi definido como fumar um ou mais cigarros nos últimos 30 dias. Saúde mental foi avaliada de acordo com o escore total do questionário Strengths and Difficulties Questionnaire e escore maior ou igual a 20 pontos foi considerado como positivo. Os dados foram analisados por regressão de Poisson, com ajuste robusto para variância. RESULTADOS: A prevalência de tabagismo foi 6,0% e cerca de 30% dos adolescentes apresentaram algum tipo de problema de saúde mental. Na análise bruta, a razão de prevalências para tabagismo foi de 3,3 (IC95% 2,5; 4,2). Após ajuste (para sexo, idade, cor da pele, renda familiar, escolaridade da mãe, grupo de amigos fumantes, trabalho no último ano, repetência escolar, atividade física de lazer e uso experimental de bebida alcoólica), diminuiu para 1,7 (IC95% 1,2; 2,3) entre aqueles com problemas de saúde mental. CONCLUSÕES: Problemas de saúde mental na adolescência podem ter relação com o consumo de tabaco.OBJETIVO: Analizar la asociación entre problemas de salud mental y uso de cigarro en adolescentes. MÉTODOS: Se analizaron 4.325 adolescentes de 15 años de la cohorte de nacimientos de 1993 de la ciudad de Pelotas, Sur de Brasil. Tabaquismo fue definido como fumar uno o más cigarros en los últimos 30 días. Salud mental fue evaluada de acuerdo con el escore total del cuestionario Strengths and Difficulties Questionnaire y escore mayor o igual a 20 puntos fue considerado como positivo. Los datos fueron analizados por regresión de Poisson, con ajuste robusto para varianza. RESULTADOS: La prevalencia de tabaquismo fue 6,0% y cerca de 30% de los adolescentes presentaron algún tipo de problema de salud mental. En el análisis bruto, la tasa de prevalencias de problema de tabaquismo de 3,3 (IC95% 2,5;4,2). Posterior al ajuste para sexo, edad, color de la piel, renta familiar, escolaridad de la madre, grupo de amigos fumadores, trabajo en el último año, repitencia escolar, actividad física de ocio y uso experimental de bebida alcohólica, disminuyó a 1,7 (IC95% 1,2;2,3) entre aquellos con problemas de salud mental. CONCLUSIONES: Problemas de salud mental en la adolescencia pueden tener relación con el consumo de tabaco

The Temporal Pattern of Mating Behavior of the Fruit Fly, Anastrepha zenildae in the Laboratory

The state of Rio Grande do Norte is an important fruit-producing and exporting area in northeastern Brazil. The success of this industry depends on fruit fly population control, especially in fly-free exporting zones. However, many fruits are not exported because of quarantine restrictions imposed by importing countries. A survey in the state has detected a considerable increase of the fruit fly, Anastrepha zenildae Zucchi (Diptera: Tephritidae), probably a result of the introduction of irrigated guava orchards that make fruit available all year. Knowledge of the sexual behavior of Tephritidae has great importance to pest control programs, particularly those that employ the Sterile Insect Technique. In order to characterize the reproductive behavior of A. zenildae, 32 individuals (16 males; 16 females) in each of six generations were submitted to an artificial 12:12 L:D cycle (750: < 1 lux, lights on 07:00–19:00) and observed over their lifetimes. The courtship and copulation occurred in leks and the episodes varied with the time of day, courtship being most frequent between Zeitgeber time (ZT) 3 and ZT 7, peaking at ZT 5–6. Copulations occurred between ZT 2 and ZT 8, with a higher frequency between ZT 5–7 and a peak at ZT 6. Mean duration was 0.28 ± 0.03 min/male (range: 5–163 min). Males in the leks attempted to copulate mainly between ZT 3 and ZT 7 with a peak at ZT 6, and males outside leks peaked at ZT 7. The different timing of sexual behaviors among related sympatric species, including A. zenildae, may contribute to species isolation