321 research outputs found
Impact of potassium and phosphorus in biomass on the properties of fast Pyrolysis bio-oil
This study investigates fast pyrolysis bio-oils produced from alkali-metal-impregnated biomass (beech wood). The impregnation aim is to study the catalytic cracking of the pyrolysis vapors as a result of potassium or phosphorus. It is recognized that potassium and phosphorus in biomass can have a major impact on the thermal conversion processes. When biomass is pyrolyzed in the presence of alkali metal cations, catalytic cracking of the pyrolysis liquids occurs in the vapor phase, reducing the organic liquids produced and increasing yields of water, char, and gas, resulting in a bio-oil that has a lower calorific value and an increased chance of phase separation. Beech wood was impregnated with potassium or phosphorus (K impregnation and P impregnation, respectively) in the range of 0.10-2.00 wt %. Analytical pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) was used to examine the distribution of char and volatiles. Both potassium and phosphorus are seen to catalyze the pyrolytic decomposition of biomass and modify the yields of products. 3-Furaldehyde and levoglucosenone become more dominant products upon P impregnation, pointing to rearrangement and dehydration routes during the pyrolysis process. Potassium has a significant influence on cellulose and hemicellulose decomposition, not just on the formation of levoglucosan but also other species, such as 2(5H)-furanone or hydroxymethyl-cyclopentene derivatives. Fast pyrolysis processing has also been undertaken using a laboratory-scale continuously fed bubbling fluidized-bed reactor with a nominal capacity of 1 kg h-1 at the reaction temperature of 525 °C. An increase in the viscosity of the bio-oil during the stability assessment tests was observed with an increasing percentage of impregnation for both additives. This is because bio-oil undergoes polymerization while placed in storage as a result of the inorganic content. The majority of inorganics are concentrated in the char, but small amounts are entrained in the pyrolysis vapors and, therefore, end up in the bio-oil
Coxiella burnetii Phagocytosis Is Regulated by GTPases of the Rho Family and the RhoA Effectors mDia1 and ROCK
The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the host´s cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C. burnetii by phagocytic and non-phagocytic cells. The internalization of C. burnetii into HeLa and RAW cells was significantly inhibited when the cells were treated with Clostridium difficile Toxin B which irreversibly inactivates members of the Rho family. In addition, the internalization was reduced in HeLa cells that overexpressed the dominant negative mutants of RhoA, Rac1 or Cdc42 or that were knocked down for the Rho GTPases. The pharmacological inhibition or the knocking down of ROCK diminished bacterium internalization. Moreover, C. burnetii was less efficiently internalized in HeLa cells overexpressing mDia1-N1, a dominant negative mutant of mDia1, while the overexpression of the constitutively active mutant mDia1-ΔN3 increased bacteria uptake. Interestingly, when HeLa and RAW cells were infected, RhoA, Rac1 and mDia1 were recruited to membrane cell fractions. Our results suggest that the GTPases of the Rho family play an important role in C. burnetii phagocytosis in both HeLa and RAW cells. Additionally, we present evidence that ROCK and mDia1, which are downstream effectors of RhoA, are involved in that processFil: Salinas Ojeda, Romina Paola. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Ortiz Flores, Rodolfo Matias. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Distel, Jesús Sebastián. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Aguilera, Milton Osmar. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Beron, Walter. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de HistologÃa y EmbriologÃa de Mendoza Dr. Mario H. Burgos; Argentin
Single Assay for Simultaneous Detection and Differential Identification of Human and Avian Influenza Virus Types, Subtypes, and Emergent Variants
For more than four decades the cause of most type A influenza virus infections of humans has been attributed to only two viral subtypes, A/H1N1 or A/H3N2. In contrast, avian and other vertebrate species are a reservoir of type A influenza virus genome diversity, hosting strains representing at least 120 of 144 combinations of 16 viral hemagglutinin and 9 viral neuraminidase subtypes. Viral genome segment reassortments and mutations emerging within this reservoir may spawn new influenza virus strains as imminent epidemic or pandemic threats to human health and poultry production. Traditional methods to detect and differentiate influenza virus subtypes are either time-consuming and labor-intensive (culture-based) or remarkably insensitive (antibody-based). Molecular diagnostic assays based upon reverse transcriptase-polymerase chain reaction (RT-PCR) have short assay cycle time, and high analytical sensitivity and specificity. However, none of these diagnostic tests determine viral gene nucleotide sequences to distinguish strains and variants of a detected pathogen from one specimen to the next. Decision-quality, strain- and variant-specific pathogen gene sequence information may be critical for public health, infection control, surveillance, epidemiology, or medical/veterinary treatment planning. The Resequencing Pathogen Microarray (RPM-Flu) is a robust, highly multiplexed and target gene sequencing-based alternative to both traditional culture- or biomarker-based diagnostic tests. RPM-Flu is a single, simultaneous differential diagnostic assay for all subtype combinations of type A influenza viruses and for 30 other viral and bacterial pathogens that may cause influenza-like illness. These other pathogen targets of RPM-Flu may co-infect and compound the morbidity and/or mortality of patients with influenza. The informative specificity of a single RPM-Flu test represents specimen-specific viral gene sequences as determinants of virus type, A/HN subtype, virulence, host-range, and resistance to antiviral agents
Localization of polyhydroxybutyrate in sugarcane using Fourier-transform infrared microspectroscopy and multivariate imaging
An alternative application to the portuguese agro-industrial residue : wheat straw
The effects of alkaline treatments of the wheat straw with sodium hydroxide were investigated. The optimal condition for extraction of hemicelluloses was found to be with 0.50 mol/l sodium hydroxide at 55 °C for 2 h. This resulted in the release of 17.3% of hemicellulose (% dry starting material), corresponding to the dissolution of 49.3% of the original hemicellulose. The yields were determined by gravimetric analysis and expressed as a proportion of the starting material. Chemical composition and physico-chemical properties of the samples of hemicelluloses were elucidated by a combination of sugar analyses, Fourier transform infrared (FTIR), and thermal analysis. The results showed that the treatments were very effective on the extraction of hemicelluloses from wheat straw and that the extraction intensity (expressed in terms of alkali concentration) had a great influence on the yield and chemical features of the hemicelluloses. The FTIR analysis revealed typical signal pattern for the hemicellulosic fraction in the 1,200–1,000 cm−1 region. Bands between 1,166 and 1,000 cm−1 are typical of xylans.Conselho Nacional de
Desenvolvimento CientÃfico e Tecnológico (CNPq)Fundação de Amparo a Pesquisa do Estado de São Paulo/Brazil (FAPESP)Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/26156/2005, SFRH/BPD/26108/200
Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network.
OBJECTIVE: This report presents data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network on care of and morbidity and mortality rates for very low birth weight infants, according to gestational age (GA).
METHODS: Perinatal/neonatal data were collected for 9575 infants of extremely low GA (22-28 weeks) and very low birth weight (401-1500 g) who were born at network centers between January 1, 2003, and December 31, 2007.
RESULTS: Rates of survival to discharge increased with increasing GA (6% at 22 weeks and 92% at 28 weeks); 1060 infants died at
CONCLUSION: Although the majority of infants with GAs of \u3eor=24 weeks survive, high rates of morbidity among survivors continue to be observed
Sex- and Age-Related Differences in Morbidity Rates of 2009 Pandemic Influenza A H1N1 Virus of Swine Origin in Japan
BACKGROUND: The objective of the present study was to determine whether the morbidity rates of the 2009 pandemic influenza A H1N1 virus (pdmH1N1) varied by age and/or sex. METHODS AND FINDINGS: Retrospective analysis of 2,024,367 cases of pdmH1N1 was performed using the national surveillance data from influenza sentinel points in Japan. The male-to-female morbidity ratios (M/F ratios) in nineteen age groups were estimated as the primary outcome. The M/F ratios for pdmH1N1 influenza were: >1 in age groups <20 years and ≥80 years (p<0.001); <1 in age groups 20-79 years (p<0.001). This data suggests that males <20 years of age may be more likely to suffer from pdmH1N1 influenza than females in the same age categories. When the infection pattern for pdmH1N1 was compared with that of seasonal influenza outbreaks between 2000 and 2008, the M/F ratio for pdmH1N1 influenza was higher in ages 3-29 years and lower in ages 40-79 years. Because the present study was based on the national surveillance, it was impossible to estimate the morbidity rate for the Japanese population. It is also likely that the data did not capture asymptomatic or mild infections. CONCLUSIONS: Although exposure to the pdmH1N1 virus is assumed to be similar in both boys and girls, M/F ratios were >1 in those younger than 20 years. The subsequent reversal of the M/F ratio in the adult generation could be due to several possibilities, including: greater immunity among adult males, more asymptomatic infections among males, less reporting of illness by males, or differences in exposure to the virus and probability of visiting a clinic. These results suggest that the infection and virulence patterns of pdmH1N1 are more complex than previously considered
Valorization, comparison and characterization of coconuts waste and cactus in a biorefinery context using NaClO2-C2H4O2 and sequential NaClO2-C2H4O2/autohydrolysis pretreatment
The search for new sources of lignocellulosic raw materials for the generation of energy and new compounds encourages the search for locations not well known and with a high potential for biomass availability as is the case of the Northeast Region of Brazil. Thus, the cactus (CAC), green coconut shell (GCS), mature coconut fibre and mature coconut shell were pretreated by NaClO2C2H4O2 and sequential NaClO2C2H4O2/autohydrolysis aiming at the obtention of high added-value compounds in the liquid fraction and solid phase. The yield of the solid phase was between 61.42 and 90.97% and the reduction up to 91.63% of lignin in the materials pretreated by NaClO2C2H4O2. After NaClO2C2H4O2/autohydrolysis pretreatment the obtained solids yield was between 43.57 and 52.08%, with a solubilization of the hemicellulose content up to 81.42%. For both pretreatments the cellulosic content remained almost unchanged. The pretreated solids were characterized by SEM, X-ray and crystallinity indexes showing significant modifications when submitted to pretreatments. These results were further confirmed by the enzymatic conversion yields of 81.6890.03 and 86.9790.36% of the LCMs pretreated by NaClO2C2H4O2 and pretreated by NaClO2C2H4O2/autohydrolysis, respectively. The resulting liquors had a total phenolic compounds content between 0.20 and 3.05 g/L, lignin recovered up to 7.40 g/L (absence of sulphur) and xylooligosaccharides between 16.13 and 20.37 g/L. Thus, these pretreatments showed an efficient fractionation of LCMs, especially in the GCS, being an important requirement for the generation of products and byproducts in the context of the biorefinery.The authors gratefully acknowledge the Brazilian research funding agencies CNPq and CAPES for financial support. Financial support from the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (CemieBio), Cluster of Bioalcohols (Ref. 249564) is gratefully acknowledged. We also gratefully acknowledge support for this research by the Mexican Science and Technology Council (CONACYT, Mexico) for the infrastructure project - INFR201601 (Ref. 269461) and CB-2015-01 (Ref. 254808).info:eu-repo/semantics/publishedVersio
Enzymatic hydrophobic modification of jute fibers via grafting to reinforce composites
Horseradish peroxidase (HRP)/H2O2 system catalyzes the free-radical polymerization of aromatic compounds such as lignins and gallate esters. In this work, dodecyl gallate (DG) was grafted onto the surfaces of lignin-rich jute fabrics by HRP-mediated oxidative polymerization with an aim to enhance the hydrophobicity of the fibers. The DG-grafted jute fibers and reaction products of their model compounds were characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results clearly indicated the grafting of DG to the jute fiber by HRP. Furthermore, the hydrophobicity of jute fabrics was determined by measuring the wetting time and static contact angle. Compared to the control sample, the wetting time and static contact angle of the grated fabrics changed from ~1 s to 1 h and from ~0° to 123.68°, respectively. This clearly proved that the hydrophobicity of jute fabrics improved considerably. Conditions of the HRP-catalyzed DG-grafting reactions were optimized in terms of the DG content of modified jute fabrics. Moreover, the results of breaking strength and elongation of DG-grafted jute/ polypropylene (PP) composites demonstrated improved reinforcement of the composite due to enzymatic hydrophobic modification of jute fibers.This work was financially supported by the National Natural Science Foundation of China (51173071), the Program for New Century Excellent Talents in University (NCET-12-0883), Program for Changjiang Scholars and Innovative Research Team in University (No. IRT_15R26) the Fundamental Research Funds for the Central Universities (JUSRP51312B, JUSRP51505), and the Graduate Student Innovation Plan of Jiangsu Province of China (SJLX_0527)
Different modes of state transitions determine pattern in the Phosphatidylinositide-Actin system
<p>Abstract</p> <p>Background</p> <p>In a motile polarized cell the actin system is differentiated to allow protrusion at the front and retraction at the tail. This differentiation is linked to the phosphoinositide pattern in the plasma membrane. In the highly motile <it>Dictyostelium </it>cells studied here, the front is dominated by PI3-kinases producing PI(3,4,5)tris-phosphate (PIP3), the tail by the PI3-phosphatase PTEN that hydrolyses PIP3 to PI(4,5)bis-phosphate. To study de-novo cell polarization, we first depolymerized actin and subsequently recorded the spontaneous reorganization of actin patterns in relation to PTEN.</p> <p>Results</p> <p>In a transient stage of recovery from depolymerization, symmetric actin patterns alternate periodically with asymmetric ones. The switches to asymmetry coincide with the unilateral membrane-binding of PTEN. The modes of state transitions in the actin and PTEN systems differ. Transitions in the actin system propagate as waves that are initiated at single sites by the amplification of spontaneous fluctuations. In PTEN-null cells, these waves still propagate with normal speed but loose their regular periodicity. Membrane-binding of PTEN is induced at the border of a coherent PTEN-rich area in the form of expanding and regressing gradients.</p> <p>Conclusions</p> <p>The state transitions in actin organization and the reversible transition from cytoplasmic to membrane-bound PTEN are synchronized but their patterns differ. The transitions in actin organization are independent of PTEN, but when PTEN is present, they are coupled to periodic changes in the membrane-binding of this PIP3-degrading phosphatase. The PTEN oscillations are related to motility patterns of chemotaxing cells.</p
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