270 research outputs found

    Furfural, 5-HMF, acid-soluble lignin and sugar contents in C. ladanifer and E. arborea lignocellulosic biomass hydrolysates obtained from microwave-assisted treatments in different solvents

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    Cistus ladanifer L. and Erica arborea L. are the two most representative shrub species from the Iberian Peninsula. With a view to their valorization, their biomass hydrolysate components, obtained from microwave-assisted treatments with choline chloride/urea - HNO3 10%, N,N-dimethylacetamide/NaHCO3 and N,N-dimethylacetamide/CH3OK as solvents, have been measured using a spectrophotometric method. Concentrations of furfural and 5-(hydroxymethyl)furfural (5-HMF) in the filtrate have been determined after reduction with NaBH4. The production of total sugars, reducing sugars and non-reducing sugars has also been assessed. The obtained results support the choice of microwave-assisted choline chloride/urea deep eutectic solvent in acid media as the preferred method (over the polar aprotic solvent-based alternatives) for the extraction of lignin, furfural, 5-HMF and sugars from C. ladanifer and E. arborea biomass, attaining the best production yields for 60¿min exposure times. Another is the case if the aim of the treatments is to recovery sugars from both shrubs for subsequent enzymatic saccharification: the very low 5-HMF contents resulting from the dimetylacetamide systems (especially is association with CH3OK) make them highly advantageous as compared to the traditional method using NaOH

    Crystallinity of cellulose microfibers derived from Cistus ladanifer and Erica arborea shrubs

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    The effectiveness of the use of cellulose fibers as particulates/composite reinforcers involves the assessment of the crystallinity of such fibers. The aim of the present work is to provide information on the degree of crystallinity of the cellulose microfibers obtained from the stems of Cistus ladanifer and Erica arborea shrubs through two different methods, namely an alkaline treatment and a microwave-assisted deep eutectic solvent (DES) method. The crystallinity indexes (CrI) obtained from X-ray powder diffraction patterns indicated that higher CrI were attained for cellulose obtained from the DES treatment. Complementary information on the degree of crystallinity was also retrieved from attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) vibrational spectra, scanning electron microscopy (SEM) micrographs, and accessibility data for the DES-treated celluloses from the two species. The crystallinity results for the fibers derived from these two Mediterranean shrubs were within the range of the results for those derived from wood pulp, opening the door to their valorization for cellulose-derived packing applications or for their use as reinforcers in composite materials in combination with other biopolymers

    Mediterranean shrublands as carbon sinks for climate change mitigation: new root-to-shoot ratios

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    Shrublands play an important role in the reduction of atmospheric CO2 and contribute to the mitigation of the effects of climate change, due to their ability to act as carbon sinks and the large expanses of land involved. Two of the most representative shrub species in the Iberian Peninsula, Cistus ladanifer L. and Erica arborea L., were studied in terms of biomass distribution and carbon and nitrogen contents in the different fractions. With a view to fast and cost-effective estimation of radical biomass, a new procedure for easy root-to-shoot calculation based on vibrational data was proposed, resulting in an excellent agreement with the values obtained from conventional direct belowground and aerial biomass measurements: 0.23 for C. ladanifer and 0.54 for E. arborea. Carbon sequestration, estimated at 45 and 73 t CO2 eq·ha-1 for C. ladanifer and E. arborea, respectively, was subsequently determined. Since these values are substantially higher than those of other shrubs, these two key species can be deemed particularly promising for ecological restoration and carbon offsetting

    Virulence factors and antimicrobial resistance in environmental strains of Vibrio alginolyticus

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    Vibrio alginolyticus has acquired increasing importance because this microorganism may be pathogenic to aquatic animals and humans. It has been reported that some V. alginolyticus strains carry virulence genes derived from pathogenic V. cholerae and V. parahaemolyticus strains. In this work V. alginolyticus was isolated from oyster samples acquired from a food-market in Mexico City. Thirty isolates were identified as V. alginolitycus. Strains showed β-haemolysis and proteolytic activity and produced a capsule. Strains displayed swimming and swarming motility and 93.3% of them produced siderophores. Several genes encoding virulence factors were detected using PCR amplification. These included proA, wza, vopD, vopB, hcp, vasH and vgrG genes, which were present in all strains. Other genes had a variable representation: tdh (86.6%), lafA (96.6%), pvsA (62%) and pvuA (16%). The trh gene could not be amplified from any of the strains. The antimicrobial resistance profile revealed that more than 90% of the strains were resistant to beta-lactams antibiotics, 60% to cephalotin, 45% to amikacin, 16% to cephotaxime, and 10% to pefloxacin, while 100% were susceptible to ceftriaxone. The V. alginolyticus strains isolated from oysters showed multiple resistance to antibiotics and several virulence factors described in well-characterized pathogenic vibrios. [Int Microbiol 19(4):191-198 (2016)]Keywords: Vibrio alginolyticus · secretion system · virulence factors · capsular polyssacharides · oyster

    Valorization of Cistus ladanifer and Erica arborea shrubs for fuel: Wood and bark thermal characterization

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    As a form of upgraded biomass characterized by its high energy density, low production costs, and low process energy requirements, wood pellets are an environmentally friendly fuel allowing for carbon neutral heating with high energy efficiency. In this work, the suitability of a valorization of the woods from the two most representative shrub species from the Iberian Peninsula (namely Cistus ladanifer and Erica arborea) for heating has been assessed. Whereas Erica arborea met the requirements of ISO 17225-2:2014 for ENplus-B class (the calorific content for both wood and bark was high and not significantly different, and the ash content was permissible for specimens with branch diameter ≥2,8 cm), Cistus ladanifer was in the limit of the normative and only met the requirements in terms of acceptable ash percentage (1,9%) and heating value (19 kJ·g-1) for old specimens with branch diameters >3,4 cm. Consequently, while the harvest of E. arborea for its use as fuel does not need to be selective, that of C. ladanifer should be limited to the most robust specimens and foliage should be avoided.   PDF XM

    Crystallinity of cellulose microfibers derived from Cistus ladanifer and Erica arborea shrubs

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    The effectiveness of the use of cellulose fibers as particulates/composite reinforcers involves the assessment of the crystallinity of such fibers. The aim of the present work is to provide information on the degree of crystallinity of the cellulose microfibers obtained from the stems of Cistus ladanifer and Erica arborea shrubs through two different methods, namely an alkaline treatment and a microwave-assisted deep eutectic solvent (DES) method. The crystallinity indexes (CrI) obtained from X-ray powder diffraction patterns indicated that higher CrI were attained for cellulose obtained from the DES treatment. Complementary information on the degree of crystallinity was also retrieved from attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) vibrational spectra, scanning electron microscopy (SEM) micrographs, and accessibility data for the DES-treated celluloses from the two species. The crystallinity results for the fibers derived from these two Mediterranean shrubs were within the range of the results for those derived from wood pulp, opening the door to their valorization for cellulose-derived packing applications or for their use as reinforcers in composite materials in combination with other biopolymers

    Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV

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    Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS detector at the LHC in 2011. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.Comment: Submitted to Physical Review

    HIGH PREVALENCE OF Strongyloides stercoralis INFECTION AMONG THE ELDERLY IN BRAZIL

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    SUMMARY Little is known about the frequency of intestinal parasites in the elderly due to a lack of attention given to the occurrence of these infections among older adults. This study compares the frequency of Strongyloides stercoralis and other enteroparasites between elderly living in nursing homes (n = 100) and those noninstitutionalized (n = 100) from Uberlândia, state of Minas Gerais, southeastern Brazil, associated with data of epidemiological and socio-demographic conditions. Through coproparasitological examination of both groups, enteroparasites were detected in 15 of 200 individuals examined (7.5%; CI: 5.1- 9.9). S. stercoralis was the most frequent parasite 10/200 (5%; CI: 4.2-5.8), being significantly higher in males and in individuals with autonomy for daily living activities. There were no statistical differences in the prevalence of parasites between the two groups compared. In conclusion, S. stercoralis infection was highly prevalent in elderly patients and it does not depend on whether the individual was institutionalized or not

    Natural History of MYH7-Related Dilated Cardiomyopathy

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    BACKGROUND Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVES We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 +/- 19.2 years) recruited from 29 international centers. RESULTS At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% +/- 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of <= 35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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