2,096 research outputs found
High pressure pre-treatments promote higher rate and degree of enzymatic hydrolysis of cellulose
The effect of high pressure (HP) pre-treatments on the subsequent enzymatic hydrolysis of cellulose from bleached kraft Eucalyptus globulus pulp by cellulase from Tricoderma viride was evaluated. Pressure pre-treatments of 300 and 400 MPa during 5–45 min, lead to both an increased rate and degree of hydrolysis, reaching values ranging from 1.5- to 1.9-fold, quantified by the formation of reducing sugars. Both the pressure and time under pressure influenced the enzymatic hydrosability of the cellulosic pulps, with the former being more important. The results indicate that the pressure pre-treatments promoted an increased accessibility of cellulose towards cellulase in the cell wall. The results obtained open promising possibilities, to contribute to overcome conventional limitations of enzymatic cellulose hydrolysis for the production of fermentable glucose, for the production of second generation bioethanol and chemicals by enhancement of both rate and yield of hydrolysis. The results are also of interest for the preparation of “pressure engineered” celullose with incremented tailored hydrolysis patterns
Respiratory symptoms (COPD Assessment Test and modified Medical Research Council dyspnea scores) and GOLD-ABCD COPD classification: the LASSYC study
Chronic obstructive pulmonary disease; Symptoms; COPDEnfermedad pulmonar obstructiva crónica; Síntomas; EPOCMalaltia pulmonar obstructiva crònica; Símptomes; MPOCObjective
To assess the frequency and severity of 24-hour respiratory symptoms according to COPD GOLD-ABCD classification (2017-version), the distribution of the patients with COPD into GOLD categories using mMRC (≥2) or CAT (≥10) scores, and agreement between these cut-off points.
Methods
In this cross-sectional study (LASSYC study), 24-hour day respiratory symptoms were assessed by the Evaluating Respiratory Symptoms in COPD (E-RS) questionnaire, Nighttime Symptoms of COPD Instrument (NiSCI), Early Morning Symptoms of COPD Instrument (EMSCI), CAT and mMRC scores.
Results
Among the 734 patients with COPD, 61% were male, age 69.6±8.7 years, FEV1% post-BD 49.1±17.5%, mMRC 1.8±1.0 and CAT 15.3±.8.1. By mMRC 33.7% were group-A, 29.2% group-B, 10.2% group-C and 26.9% group-D. By CAT 22.3% were group-A, 41% group-B, 4.8% group-C and 31.9% group-D. Using the mMRC the severity of E-RS, NiSCI and EMSCI scores increased from group A to D. Using the CAT, the groups B and D had the higher scores. Agreement between mMRC and CAT was 89.5% (Kappa statistics=75.7%). For mMRC score of 2, CAT score of ≥11 showed the maximum Youden’s index (1.34). For mMRC score of 1, CAT score of ≥9 and ≥10 showed the maximum Youden’s index (1.48).
Conclusion
GOLD COPD classification by CAT seems to better discriminate 24-hour symptoms. Results do not support the equivalent use of CAT≥10 and mMRC≥2 for assessing symptoms.This observational study was funded by AstraZeneca Latin America. The funder had no input into the study design, analysis, or interpretation of the results
Characterization of an hrp-aox-polyaniline-graphite composite biosensor
Nowadays there is an increasing demand to develop new and robust biosensors in order to detect low concentrations of different chemicals, in practical and small devices, giving fast and confident responses. The electrode material was a polyaniline-graphite-epoxy composite (PANI/GEC). Alcohol oxidase (AOX) and horseradish peroxidase (HRP) enzymes were immobilized and the responses were tested by cyclic voltammetry. The conductivities for the composites of graphite/polyaniline were determined. The cyclic voltammograms allowed detecting ethanol in pure diluted samples in a range from 0.036 to 2.62 M. Differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) were used to verify the thermal characteristics of the composites (0, 10, 20, 30 and 100 % of graphite). The Imax value was determined for the dual enzyme biosensor (0.0724 mA), and the Kapp m as 1.41 M (with R2 =0.9912)
Differential Role of Human Choline Kinase α and β Enzymes in Lipid Metabolism: Implications in Cancer Onset and Treatment
11 pages, 6 figures, 1 table.Background
The Kennedy pathway generates phosphocoline and phosphoethanolamine through its two branches. Choline Kinase (ChoK) is the first enzyme of the Kennedy branch of synthesis of 1phosphocholine, the major component of the plasma membrane. ChoK family of proteins is composed by ChoKα and ChoKβ isoforms, the first one with two different variants of splicing. Recently ChoKα has been implicated in the carcinogenic process, since it is over-expressed in a variety of human cancers. However, no evidence for a role of ChoKβ in carcinogenesis has been reported.
Methodology/Principal Findings
Here we compare the in vitro and in vivo properties of ChoKα1 and ChoKβ in lipid metabolism, and their potential role in carcinogenesis. Both ChoKα1 and ChoKβ showed choline and ethanolamine kinase activities when assayed in cell extracts, though with different affinity for their substrates. However, they behave differentially when overexpressed in whole cells. Whereas ChoKβ display an ethanolamine kinase role, ChoKα1 present a dual choline/ethanolamine kinase role, suggesting the involvement of each ChoK isoform in distinct biochemical pathways under in vivo conditions. In addition, while overexpression of ChoKα1 is oncogenic when overexpressed in HEK293T or MDCK cells, ChoKβ overexpression is not sufficient to induce in vitro cell transformation nor in vivo tumor growth. Furthermore, a significant upregulation of ChoKα1 mRNA levels in a panel of breast and lung cancer cell lines was found, but no changes in ChoKβ mRNA levels were observed. Finally, MN58b, a previously described potent inhibitor of ChoK with in vivo antitumoral activity, shows more than 20-fold higher efficiency towards ChoKα1 than ChoKβ.
Conclusion/Significance
This study represents the first evidence of the distinct metabolic role of ChoKα and ChoKβ isoforms, suggesting different physiological roles and implications in human carcinogenesis. These findings constitute a step forward in the design of an antitumoral strategy based on ChoK inhibition.This work has been supported by grants to JCL from Comunidad de Madrid (GR-SAL-0821-2004), Ministerio de Ciencia e Innovación (SAF2008-03750, RD06/0020/0016), Fundación Mutua Madrileña, and by a grant to ARM from Fundación Mutua Madrileña.Peer reviewe
Compact focusing grating couplers for silicon horizontal slot waveguides
In this Letter, we present the design, simulation (2D and 3D), fabrication, and experimental characterization of compact and fully etched focusing gratings for a horizontal slot waveguide based on a silicon nitride layer sandwiched between amorphous silicon and a silicon-on-insulator. The measured coupling losses are about 4 dB with a 3 dB bandwidth of 38 nm. The fully etched configuration allows the fabrication
in a single lithography step.Ministerio de Economia y Competitividad (MINECO) (TEC2012-38540-C02-02, TEC2016-76849-C2-2-R); Generalitat Valenciana (NANOMET PLUS -PROMETEOII/2014/034).Larrea-Luzuriaga, RA.; Gutiérrez Campo, AM.; Hurtado Montañés, J.; Ramirez, JM.; Garrido, B.; Sanchis Kilders, P. (2017). Compact focusing grating couplers for silicon horizontal slot waveguides. Optics Letters. 42(3):490-493. https://doi.org/10.1364/OL.42.000490S49049342
Evaluation of Jackknife and Bootstrap for Defining Confidence Intervals for Pairwise Agreement Measures
Several research fields frequently deal with the analysis of diverse classification results of the same entities. This should imply an objective detection of overlaps and divergences between the formed clusters. The congruence between classifications can be quantified by clustering agreement measures, including pairwise agreement measures. Several measures have been proposed and the importance of obtaining confidence intervals for the point estimate in the comparison of these measures has been highlighted. A broad range of methods can be used for the estimation of confidence intervals. However, evidence is lacking about what are the appropriate methods for the calculation of confidence intervals for most clustering agreement measures. Here we evaluate the resampling techniques of bootstrap and jackknife for the calculation of the confidence intervals for clustering agreement measures. Contrary to what has been shown for some statistics, simulations showed that the jackknife performs better than the bootstrap at accurately estimating confidence intervals for pairwise agreement measures, especially when the agreement between partitions is low. The coverage of the jackknife confidence interval is robust to changes in cluster number and cluster size distribution
Effects of High-Intensity Interval Training vs. Sprint Interval Training on Anthropometric Measures and Cardiorespiratory Fitness in Healthy Young Women
Purpose: To compare the effects of 8 weeks of two types of interval training, Sprint Interval Training (SIT) and High-Intensity Interval Training (HIIT), on anthropometric measures and cardiorespiratory fitness in healthy young women.Methods: A randomized clinical trial in which 49 young active women [age, 30.4 ± 6.1 years; body mass index, 24.8 ± 3.1 kg.m−2; peak oxygen consumption (VO2peak), 34.9±7.5 mL.kg−1.min−1] were randomly allocated into a SIT or HIIT group. The SIT group performed four bouts of 30 s all-out cycling efforts interspersed with 4 min of recovery (passive or light cycling with no load). The HIIT group performed four bouts of 4-min efforts at 90–95% of peak heart rate (HRpeak) interspersed with 3 min of active recovery at 50–60% of HRpeak. At baseline and after 8 weeks of intervention, waist circumference, skinfolds (triceps, subscapular, suprailiac, abdominal, and thigh), body mass and BMI were measured by standard procedures and cardiorespiratory fitness was assessed by cardiorespiratory graded exertion test on an electromagnetically braked cycle ergometer.Results: The HIIT and SIT groups improved, respectively, 14.5 ± 22.9% (P < 0.001) and 16.9 ± 23.4% (P < 0.001) in VO2peak after intervention, with no significant difference between groups. Sum of skinfolds reduced 15.8 ± 7.9 and 22.2 ± 6.4 from baseline (P < 0.001) for HIIT and SIT groups, respectively, with greater reduction for SIT compared to HIIT (P < 0.05). There were statistically significant decreases in waist circumference (P < 0.001) for the HIIT (−3.1 ± 1.1%) and SIT (−3.3 ± 1.8%) groups, with no significant difference between groups. Only SIT showed significant reductions in body weight and BMI (p < 0.05).Conclusions: Eight weeks of HIIT and SIT resulted in improvements in anthropometric measures and cardiorespiratory fitness, even in the absence of changes in dietary intake. In addition, the SIT protocol induced greater reductions than the HIIT protocol in the sum of skinfolds. Both protocols appear to be time-efficient interventions, since the HIIT and SIT protocols took 33 and 23 min (16 and 2 min of effective training) per session, respectively
Development of lipopolyplexes for gene delivery: a comparison of the effects of differing modes of targeting peptide display on the structure and transfection activities of lipopolyplexes
The design, synthesis and formulation of non‐viral gene delivery vectors is an area of renewed research interest. Amongst the most efficient non‐viral gene delivery systems are lipopolyplexes, in which cationic peptides are co‐formulated with plasmid DNA and lipids. One advantage of lipopolyplex vectors is that they have the potential to be targeted to specific cell types by attaching peptide targeting ligands on the surface, thus increasing both the transfection efficiency and selectivity for disease targets such as cancer cells. In this paper, we have investigated two different modes of displaying cell‐specific peptide targeting ligands at the surface of lipopolyplexes. Lipopolyplexes formulated with bimodal peptides, with both receptor binding and DNA condensing sequences, were compared with lipopolyplexes with the peptide targeting ligand directly conjugated to one of the lipids. Three EGFR targeting peptide sequences were studied, together with a range of lipid formulations and maleimide lipid structures. The biophysical properties of the lipopolyplexes and their transfection efficiencies in a basal‐like breast cancer cell line were investigated using plasmid DNA bearing genes for the expression of firefly luciferase and green fluorescent protein. Fluorescence quenching experiments were also used to probe the macromolecular organisation of the peptide and pDNA components of the lipopolyplexes. We demonstrated that both approaches to lipopolyplex targeting give reasonable transfection efficiencies, and the transfection efficiency of each lipopolyplex formulation is highly dependent on the sequence of the targeting peptide. To achieve maximum therapeutic efficiency, different peptide targeting sequences and lipopolyplex architectures should be investigated for each target cell type
Infância, exclusão social e educação como utopia realizável
A infância, como construção social, tem sofrido, no decurso da 2ª
modernidade, processos de reinstitucionalização que, em larga medida, põem em
causa as representações e imagens das crianças, dominantes nos últimos 200 anos.
A análise da (re)construção das identidades sociais e das subjectividades infantis
constitui, desse modo, uma tarefa teórica da mais exigente actualidade. O que,
entretanto, aqui se assinala é que este processo de reinstitucionalização da infância,
apesar da construção de consensos globais sobre os direitos das crianças, tem
vindo a aumentar os factores e as condições de exclusão das gerações mais jovens
face aos direitos sociais e da cidadania. Neste artigo inventariam-se alguns dos
principais indicadores de exclusão, considerando diversos espaços estruturais, e
assinalam-se alguns dos pontos de ruptura por onde pode passar a construção de
uma educação escolar centrada na afirmação activa dos direitos das crianças.Along the second modernity, childhood, as a social construction,
has undergone reinstatement processes that question the representations and
images of children that have prevailed over last two hundred years. An analysis of
the (re) construction of the social identities and childhood subjectivity thus
constitute a theoretical task of the most contemporary exigence. Nevertheless, even
though a global consensus about children’s rights has been constructed, the
increase of factors and conditions that exclude the youngest generations from
social rights and citizenship, induced by this reinstatement process of childhood,
is here emphasized. This paper lists some of the main indicators of exclusion,
considering different structural spaces, and pinpoints some turning points through
which the construction of a school education centered on the active affirmation of
the children’s rights could be attained.CIFPEC/CIEC - Centro de Investigação em Estudos da Criança, UM (UI 644 e 317 da FCT
The climate-smart village approach: Framework of an integrative strategy for scaling up adaptation options in agriculture
Increasing weather risks threaten agricultural production systems and food security across the world. Maintaining agricultural growth while minimizing climate shocks is crucial to building a resilient food production system and meeting developmental goals in vulnerable countries. Experts have proposed several technological, institutional, and policy interventions to help farmers adapt to current and future weather variability and to mitigate greenhouse gas (GHG) emissions. This paper presents the climate-smart village (CSV) approach as a means of performing agricultural research for development that robustly tests technological and institutional options for dealing with climatic variability and climate change in agriculture using participatory methods. It aims to scale up and scale out the appropriate options and draw out lessons for policy makers from local to global levels. The approach incorporates evaluation of climate-smart technologies, practices, services, and processes relevant to local climatic risk management and identifies opportunities for maximizing adaptation gains from synergies across different interventions and recognizing potential maladaptation and trade-offs. It ensures that these are aligned with local knowledge and link into development plans. This paper describes early results in Asia, Africa, and Latin America to illustrate different examples of the CSV approach in diverse agroecological settings. Results from initial studies indicate that the CSV approach has a high potential for scaling out promising climate-smart agricultural technologies, practices, and services. Climate analog studies indicate that the lessons learned at the CSV sites would be relevant to adaptation planning in a large part of global agricultural land even under scenarios of climate change. Key barriers and opportunities for further work are also discussed
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