Optimization of a laccase-mediator stage for TCF bleaching of flax pulp

7 p.-3 fig.-3 tab.Flax pulp obtained by anthraquinone-soda pulping, resulting in a kappa number of 11.1, a viscosity of 950 ml/g and 36.7% ISO brightness, was bleached in a totally chlorine-free sequence using the enzyme laccase from the fungus Pycnoporus cinnabarinus and 1-hydroxybenzotriazole (HBT) as redox mediator (stage L), followed by a hydrogen peroxide stage (P). The laccase treatment was optimized using a three-variable sequential statistical plan over the following ranges: 1–20 U/g o.d.p. (oven-dried pulp) laccase dose, 0.5–7.5% o.d.p. HBT dose and 1–24 h reaction time. The influence of these variables on several pulp properties after the P stage of the LP sequence was examined.The models defined from the results obtained predicted variations in ISO brightness, viscosity and kappa number of 57.6–74.8%, 590–955 ml/g and 0–6.2, respectively. The variables most strongly influencing these pulp properties were found to be the reaction time and the enzyme dose. A compromise was adopted as regards the operating conditions in order to ensure optimum results. The study was completed by conducting a biobleaching assay in a pressurized reactor (590 kPa) to assess the effect of oxygen pressure. The high pressure level resulted in improved pulp properties by the laccase-mediator system.This work was supported by Spanish CICyT (Project PPQ2000–1068-C02-02, and FEDER Project 2FD97-0896-C02) and Comunidad Autónoma de Madrid, the EU Commission (QLK3-99-590) and the Spanish grant 2002FI 00556.Peer reviewe

Efficient bleaching of non-woody high-quality paper pulp using lacasse-mediator systems

aDepartment of Molecular Microbiology, CIB, Consejo Superior de Investigaciones Científicas (CSIC), Velázquez 144, E-28006 Madrid, Spain; bDepartment of Textile and Paper Engineering, ETSII, Polytechnic University of Catalunya (UPC), Colón 11, E-08222 Terrassa, Spain; cDepartment of Biogeochemistry, IRNAS, CSIC, PO Box 1052, E-41080, Seville, Spain; dCelulosas de Levante SA (CELESA), Ctra. C-237, km 4.5, E-43500 Tortosa, SpainHigh-quality flax pulp was bleached in a totally-chlorine-free (TCF) sequence using a laccase-mediator system. Three fungal laccases (from Pycnoporus cinnabarinus, Trametes versicolor and Pleurotus eryngii) and two mediators, 2,2´-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and 1-hydroxybenzotriazole (HBT), were compared. P. cinnabarinus and T. versicolor laccases in the presence of HBT gave the best results in terms of high brightness and low lignin content (kappa number). The former laccase also resulted in the best preservation of cellulose and the largest removal of residual lignin as revealed by analytical pyrolysis, and was selected for subsequent TCF bleaching. Up to 90% delignification and strong brightness increase were attained after a laccase-mediator treatment followed by H2O2 bleaching. This TCF sequence was further improved by applying H2O2 under pressurized O2. In this way, we obtained up to 82% ISO brightness (compared with 37% in the initial pulp, and 60% in the peroxide-bleached control) and very low kappa number (near 1). Good results were also found when the laccase-mediator treatment was performed in a bioreactor under pressurized oxygen. The pulp properties obtained, which could not be attained by conventional TCF bleaching of flax pulp, demonstrate the feasibility of enzymatic bleaching to substitute chlorine-containing reagents in manufacturing of these high-price paper pulps.This study was supported by the European Commission (contract QLK3-99-590), the Spanish CICYT (FEDER project 2FD97-0896-C02, and projects AGL2002-00393, BIO2002-1166 and PPQ2000-1068-C02-02), the Comunidad de Madrid, and the CSIC network on “Bioremediation and Phytoremediation”.Peer reviewe

Type-3 Secretion System-induced pyroptosis protects Pseudomonas against cell-autonomous immunity

Inflammasome-induced pyroptosis comprises a key cell-autonomous immune process against intracellular bacteria, namely the generation of dying cell structures. These so-called pore-induced intracellular traps (PITs) entrap and weaken intracellular microbes. However, the immune importance of pyroptosis against extracellular pathogens remains unclear. Here, we report that Type-3 secretion system (T3SS)-expressing Pseudomonas aeruginosa ( P. aeruginosa ) escaped PIT immunity by inducing a NLRC4 inflammasome-dependent macrophage pyroptosis response in the extracellular environment. To the contrary, phagocytosis of Salmonella Typhimurium promoted NLRC4-dependent PIT formation and the subsequent bacterial caging. Remarkably, T3SS-deficient Pseudomonas were efficiently sequestered within PIT-dependent caging, which favored exposure to neutrophils. Conversely, both NLRC4 and caspase-11 deficient mice presented increased susceptibility to T3SS-deficient P. aeruginosa challenge, but not to T3SS-expressing P. aeruginosa. Overall, our results uncovered that P. aeruginosa uses its T3SS to overcome inflammasome-triggered pyroptosis, which is primarily effective against intracellular invaders. Importance Although innate immune components confer host protection against infections, the opportunistic bacterial pathogen Pseudomonas aeruginosa ( P. aeruginosa ) exploits the inflammatory reaction to thrive. Specifically the NLRC4 inflammasome, a crucial immune complex, triggers an Interleukin (IL)-1β and -18 deleterious host response to P. aeruginosa . Here, we provide evidence that, in addition to IL-1 cytokines, P. aeruginosa also exploits the NLRC4 inflammasome-induced pro-inflammatory cell death, namely pyroptosis, to avoid efficient uptake and killing by macrophages. Therefore, our study reveals that pyroptosis-driven immune effectiveness mainly depends on P. aeruginosa localization. This paves the way toward our comprehension of the mechanistic requirements for pyroptosis effectiveness upon microbial infections and may initiate targeted approaches in order to ameliorate the innate immune functions to infections. Graphical abstract Macrophages infected with T3SS-expressing P. aeruginosa die in a NLRC4-dependent manner, which allows bacterial escape from PIT-mediated cell-autonomous immunity and neutrophil efferocytosis. However, T3SS-deficient P. aeruginosa is detected by both NLRC4 and caspase-11 inflammasomes, which promotes bacterial trapping and subsequent efferocytosis of P. aeruginosa -containing-PITs by neutrophils

Carbon and nitrogen limitation increase chitosan antifungal activity in Neurospora crassa and fungal human pathogens

Chitosan permeabilizes plasma membrane and kills sensitive filamentous fungi and yeast. Membrane fluidity and cell energy determine chitosan sensitivity in fungi. A five-fold reduction of both glucose (main carbon (C) source) and nitrogen (N) increased 2-fold Neurospora crassa sensitivity to chitosan. We linked this increase with production of intracellular reactive oxygen species (ROS) and plasma membrane permeabilization. Releasing N. crassa from nutrient limitation reduced chitosan antifungal activity in spite of high ROS intracellular levels. With lactate instead of glucose, C and N limitation increased N. crassa sensitivity to chitosan further (4-fold) than what glucose did. Nutrient limitation also increased sensitivity of filamentous fungi and yeast human pathogens to chitosan. For Fusarium proliferatum, lowering 100-fold C and N content in the growth medium, increased 16-fold chitosan sensitivity. Similar results were found for Candida spp. (including fluconazole resistant strains) and Cryptococcus spp. Severe C and N limitation increased chitosan antifungal activity for all pathogens tested. Chitosan at 100 μg ml-1 was lethal for most fungal human pathogens tested but non-toxic to HEK293 and COS7 mammalian cell lines. Besides, chitosan increased 90% survival of Galleria mellonella larvae infected with C. albicans. These results are of paramount for developing chitosan as antifungal.This work was supported by Grants from the Spanish Ministries of Economy and Competitiveness (AGL 2011-29297/AGR) and (BFU 2010-16548)

Spatial and temporal facies evolution of a Lower Jurassic carbonate platform, NW Tethyan margin (Mallorca, Spain)

The variety of depositional facies of a Lower Jurassic carbonate platform has been investigated on the island of Mallorca along a transect comprising six stratigraphic profiles. Twenty-nine facies and sub-facies have been recognized, grouped into seven facies associations, ranging in depositional environment from supratidal/terrestrial and peritidal to outer platform. Spatial and temporal (2D) facies distribution along the transect reflects the evolution of the carbonate platform with time showing different facies associations, from a broad peritidal platform (stage 1) to a muddy open platform (stage 2), and finally to a peritidal to outer carbonate platform (stage 3). Stage 1 (early Sinemurian to earliest late Sinemurian) corresponds to a nearly-flat peritidal-shallow subtidal epicontinental platform with facies belts that shifted far and fast over the whole study area. The evolution from stage 1 to stage 2 (late Sinemurian) represents a rapid flooding of the epicontinental shallow platform, with more open-marine conditions, and the onset of differential subsidence. During stage 3 (latest Sinemurian), peritidal and shallow-platform environments preferentially developed to the northeast (Llevant Mountains domain) with a rapid transition to middle-outer platform environments toward the northwest (Tramuntana Range domain). Stages 1 and 3 present facies associations typical of Bahamian-type carbonates, whereas stage 2 represents the demise of the Bahamian-type carbonate factory and proliferation of muddy substrates with suspension-feeders. The described platform evolution responded to the interplay between the initial extensional tectonic phases related to Early Jurassic Tethyan rifting, contemporaneous environmental perturbations, and progressive platform flooding related to the Late Triassic–Early Jurassic worldwide marine transgression and associated accommodation changes

Carbon dioxide (CO2) emissions and adherence to Mediterranean diet in an adult population: the Mediterranean diet index as a pollution level index

Background Research related to sustainable diets is is highly relevant to provide better understanding of the impact of dietary intake on the health and the environment. Aim To assess the association between the adherence to an energy-restricted Mediterranean diet and the amount of CO2 emitted in an older adult population. Design and population Using a cross-sectional design, the association between the adherence to an energy-reduced Mediterranean Diet (erMedDiet) score and dietary CO2 emissions in 6646 participants was assessed. Methods Food intake and adherence to the erMedDiet was assessed using validated food frequency questionnaire and 17-item Mediterranean questionnaire. Sociodemographic characteristics were documented. Environmental impact was calculated through greenhouse gas emissions estimations, specifically CO2 emissions of each participant diet per day, using a European database. Participants were distributed in quartiles according to their estimated CO2 emissions expressed in kg/day: Q1 (= 2.80 kg CO2). Results More men than women induced higher dietary levels of CO2 emissions. Participants reporting higher consumption of vegetables, fruits, legumes, nuts, whole cereals, preferring white meat, and having less consumption of red meat were mostly emitting less kg of CO2 through diet. Participants with higher adherence to the Mediterranean Diet showed lower odds for dietary CO2 emissions: Q2 (OR 0.87; 95%CI: 0.76-1.00), Q3 (OR 0.69; 95%CI: 0.69-0.79) and Q4 (OR 0.48; 95%CI: 0.42-0.55) vs Q1 (reference). Conclusions The Mediterranean diet can be environmentally protective since the higher the adherence to the Mediterranean diet, the lower total dietary CO2 emissions. Mediterranean Diet index may be used as a pollution level index

Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición

[ES] En este artículo presentamos el diseño de un nuevo escáner PET para animales pequeños basado en una tecnología completamente innovadora. Los resultados preliminares son muy prometedores, permitiendo obtener imágenes funcionales de alta resolución con una instrumentación compacta y de bajo coste. Los prototipos desarrollados se encuentran actualmente en pruebas en diversos centros de investigación médica, obteniéndose imá- genes de alta calidad en los campos de oncología, neurología y cardiología. Este diseño puede ser fácilmente extendido a cámaras PET dedicadas a la exploración del cerebro o de la mama. La innovación más notable de la presente tecnología consiste en el uso de un único cristal continuo por módulo, a diferencia de otras cámaras PET comerciales donde se utilizan cientos de cristales pixelados. El uso de un único cristal continuo permite abaratar el coste de fabricación, al tiempo que mejora las características de funcionamiento: resolución intrínseca en posición de 1,2 mm, resolución en energía media del 14%, resolución en la profundidad de interacción de 3 mm, sensibilidad > 4% y campo de visión transaxial de 80 mm de diámetro. En el presente artículo se describen en detalle el diseño de esta nueva cámara PET, los principios de funcionamiento, el método utilizado para su calibración y se anticipan algunas imágenes "in vivo" del miocardio y el cerebro de un ratón, permitiendo apreciar de forma preliminar la resolución y calidad alcanzadas.[EN] In this paper we present the design of a new small animal PET scanner based on a completely innovative technology. The achieved results are very promising, showing the possibility to obtain high resolution functional images with a compact and low cost scanner. Several prototypes have been developed and are currently being used at different research medical institutions. High resolution images are being obtained in application fields like oncology, neurology and cardiology. This technology can be easily applied in PET cameras for brain or breast exploration. The most significant innovation of the design is the fact of using a single crystal per module instead of hundreds of pixellated crystals as in other commercial PETs. It has the advantage of decreasing the manufacturing costs and simultaneously improves its performance: 1.2 mm position intrinsic resolution, mean energy resolution as good as 14%, 3 mm depth of interaction resolution, sensitivity above 4%, and 80 mm diameter of transaxial field of view. In this paper we describe in detail the design of this new PET camera, its principle, the calibration methodology and also some preliminary "in vivo" images of a mouse myocardium and brain, showing the achieved image resolution and qualityBenlloch Baviera, JM.; González Martínez, AJ.; Carrilero, V.; Catret, JV.; Correcher, C.; Lerche, CW.; Morera, C.... (2007). Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición. Revista de física médica. 8(2):315-321. http://hdl.handle.net/10251/79285S3153218

Smoking cessation opportunities in severe mental illness (tobacco intensive motivational and estimate risk — TIMER—): study protocol for a randomized controlled trial

There is an increased risk of premature death in people with severe mental illness (SMI). Respiratory disorders and cardiovascular disease are leading causes of increased mortality rates in these patients, and tobacco consumption remains the most preventable risk factor involved. Developing new tools to motivate patients towards cessation of smoking is a high priority. Information on the motivational value of giving the lung age and prevention opportunities is unknown in this high-risk population. In the context of community care, screening and early detection of lung damage could potentially be used, together with mobile technology, in order to produce a prevention message, which may provide patients with SMI with a better chance of quitting smoking.This study receives funding by the Spanish Ministry of Economy, Industry and Competitiveness, Instituto Carlos III (FIS PI16/00802)

Key mechanisms governing resolution of lung inflammation

Innate immunity normally provides excellent defence against invading microorganisms. Acute inflammation is a form of innate immune defence and represents one of the primary responses to injury, infection and irritation, largely mediated by granulocyte effector cells such as neutrophils and eosinophils. Failure to remove an inflammatory stimulus (often resulting in failed resolution of inflammation) can lead to chronic inflammation resulting in tissue injury caused by high numbers of infiltrating activated granulocytes. Successful resolution of inflammation is dependent upon the removal of these cells. Under normal physiological conditions, apoptosis (programmed cell death) precedes phagocytic recognition and clearance of these cells by, for example, macrophages, dendritic and epithelial cells (a process known as efferocytosis). Inflammation contributes to immune defence within the respiratory mucosa (responsible for gas exchange) because lung epithelia are continuously exposed to a multiplicity of airborne pathogens, allergens and foreign particles. Failure to resolve inflammation within the respiratory mucosa is a major contributor of numerous lung diseases. This review will summarise the major mechanisms regulating lung inflammation, including key cellular interplays such as apoptotic cell clearance by alveolar macrophages and macrophage/neutrophil/epithelial cell interactions. The different acute and chronic inflammatory disease states caused by dysregulated/impaired resolution of lung inflammation will be discussed. Furthermore, the resolution of lung inflammation during neutrophil/eosinophil-dominant lung injury or enhanced resolution driven via pharmacological manipulation will also be considered

Actividades, realizaciones y proyectos de la Cátedra de Tecnologia Papelera de la Escuela Técnica Superior de Ingenieros Industriales de Tarrasa

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