1,898 research outputs found
Mixed matrix membranes based on ionic liquids and porous organic polymers for selective CO2 separation
The Associate Laboratory Institute for Health and Bioeconomy - i4HB ( LA/P/0140/2020 ), which are financed by national funds from FCT/MCTES. The authors also thank the National Natural Science Foundation of China (No. 21772013 ) and Beijing Natural Science Foundation (No. 2202049 ) for generous support.
Publisher Copyright:
© 2022 Elsevier B.V.The development of more efficient materials is a crucial step in the development of gas separation membranes. In this work, we combine ionic liquids (ILs) and porous organic polymers (POPs) for the first time to fabricate a new type of mixed matrix iongel membranes, which are entirely composed of organic materials. The new azo-POPs reported in this work were specifically designed due to their “CO2-philic” feature to be incorporated in iongel materials. The membranes, comprising 80 wt% of [C2mim][TFSI] IL and 20 wt% of poly(ethylene glycol) diacrylate (PEGDA) network, were prepared using a solvent-free UV curing method. The unique properties of azo-POPs within the iongel material resulted in the fabrication of dense and defect-free membranes with improved gas separation performances, in terms of both CO2 permeability (62.3–90.6 barrer) and, CO2/CH4 (9.9–12.0), CO2/H2 (6.0–12.1) and CO2/N2 (16.8–53.1) ideal selectivities, with the latter revealing to be highly dependent on the morphological properties of the azo-POPs. Furthermore, iongel characterization in terms of morphology, chemical structure and thermal properties, confirmed the potential of the novel mixed matrix iongels for CO2 separation processes.publishersversionpublishe
ESR, raman and conductivity studies on fractionated poly(2-methoxyaniline-5-sulfonic acid)
Synthesis methods used to produce poly(2-methoxyaniline-5-sulfonic acid) (PMAS), a water soluble, self-doped conducting polymer, have been shown to form two distinctly different polymer fractions with molecular weights of approximately 2 kDa and 8 -10 kDa. The low molecular weight (LMWT) PMAS fraction is redox inactive and non-conducting while the high molecular weight (HMWT) PMAS is electro-active with electrical conductivities of 0.94 0.05 S cm-1. Previous investigations have illustrated the different photochemical and electrochemical properties of these fractions, but have not correlated these properties with the structural and electronic interactions that drive them. Incomplete purification of the PMAS mixture, typically via bag dialysis, has been shown to result in a mixture of approximately 50:50 HMWT:LMWT PMAS with electrical conductivity significantly lower at approximately 0.10 to 0.26 S cm-1. The difference between the electrical conductivities of these fractions has been investigated by the controlled addition of the non-conducting LMWT PMAS fraction into the HMWT PMAS composite film with the subsequent electronic properties investigated by solid-state ESR and Raman spectroscopies. These studies illustrate strong electronic intereactions of the insulating LMWT PMAS with the emeraldine salt HMWT PMAS to substantially alter the population of the electronic charge carriers in the conducting polymer. ESR studies on these mixtures, when compared to HMWT PMAS, exhibited a lower level of electron spin in the presence of LMWT PMAS indicative of the the formation of low spin bipolarons without a change the oxidation state of the conducting HMWT fraction
Ocorrência de insetos fitófagos em Adenium obesum (Forssk.) Roem. & Schult no estado de Goiás
A rosa do deserto, Adenium obesum (Forssk.) Roem. & Schult, é uma planta ornamental da família Apocynaceae, de elevado valor comercial, que é empregada na ornamentação de jardins, praças e áreas públicas. A rápida expansão dessa espécie propiciou um ambiente favorável para sua colonização por diversas espécies de insetos e ácaros em novas regiões de introdução. Dessa forma, objetivou-se com este estudo relatar a ocorrência e injúrias ocasionadas por insetos fitófagos em A. obesum. Assim, foram realizadas observações entre o período de agosto e outubro de 2012, em plantas de rosa do deserto, empregadas no paisagismo da Universidade Federal de Goiás. A coleta foi realizada aleatoriamente, sendo os insetos armazenados em recipientes de vidro contendo etanol 70%, seguindo para identificação por taxonomistas da área. Foram identificadas duas espécies de cochonilhas: Hemiberlesia rapax Comstock (Hemiptera:
Diaspididae), Parasaissetia nigra (Nietner) (Hemiptera: Coccoidea: Pseudococcidae) e o pulgão Aphis nerii Boyer (Hemiptera: Aphididae), ocasionando injúrias nas folhas, flores e no caule da rosa do deserto. Durante as observações, verificou-se a presença de inimigos naturais de A. nerii, como parasitoides, em razão da
presença de múmias (indivíduos parasitados), e também de predadores como crisopídeos, coccinelídeos e sirfídeos. Este é o primeiro relato de ocorrência de H. rapax em A. obesum
What are we measuring? A critique of range of motion methods currently in use for Dupuytren's disease and recommendations for practice
Background: Range of motion is the most frequently reported measure used in practice to evaluate outcomes.
A goniometer is the most reliable tool to assess range of motion yet, the lack of consistency in reporting prevents comparison between studies. The aim of this study is to identify how range of motion is currently assessed and reported in Dupuytren’s disease literature. Following analysis recommendations for practice will be made to enable consistency in future studies for comparability. This paper highlights the variation in range of motion reporting in Dupuytren’s disease.
Methods: A Participants, Intervention, Comparison, Outcomes and Study design format was used for the search strategy and search terms. Surgery, needle fasciotomy or collagenase injection for primary or recurrent Dupuytren’s disease in adults were included if outcomes were monitored using range of motion to record change. A literature search was performed in May 2013 using subject heading and free-text terms to also capture electronic publications ahead of print. In total 638 publications were identified and following screening 90 articles met the inclusion criteria. Data was extracted and entered onto a spreadsheet for analysis. A thematic analysis was carried out to establish any duplication, resulting in the final range of motion measures identified.
Results: Range of motion measurement lacked clarity, with goniometry reportedly used in only 43 of the 90 studies, 16 stated the use of a range of motion protocol. A total of 24 different descriptors were identified describing range of motion in the 90 studies. While some studies reported active range of motion, others reported passive or were unclear. Eight of the 24 categories were identified through thematic analysis as possibly describing the same measure, ‘lack of joint extension’ and accounted for the most frequently used. Conclusions: Published studies lacked clarity in reporting range of motion, preventing data comparison and
meta-analysis. Percentage change lacks context and without access to raw data, does not allow direct comparison of baseline characteristics. A clear description of what is being measured within each study was required. It is recommended that range of motion measuring and reporting for Dupuytren’s disease requires consistency to address issues that fall into 3 main categories:-
Definition of terms
Protocol statement
Outcome reportin
Effect of a high-dose target-controlled naloxone infusion on pain and hyperalgesia in patients following groin hernia repair: study protocol for a randomized controlled trial
Optimal functional outcome measures for assessing treatment for Dupuytren's disease: A systematic review and recommendations for future practice
This article is available through the Brunel Open Access Publishing Fund. Copyright © 2013 Ball et al.; licensee BioMed Central Ltd.Background: Dupuytren's disease of the hand is a common condition affecting the palmar fascia, resulting in progressive flexion deformities of the digits and hence limitation of hand function. The optimal treatment remains unclear as outcomes studies have used a variety of measures for assessment. Methods: A literature search was performed for all publications describing surgical treatment, percutaneous needle aponeurotomy or collagenase injection for primary or recurrent Dupuytren’s disease where outcomes had been monitored using functional measures. Results: Ninety-one studies met the inclusion criteria. Twenty-two studies reported outcomes using patient reported outcome measures (PROMs) ranging from validated questionnaires to self-reported measures for return to work and self-rated disability. The Disability of Arm, Shoulder and Hand (DASH) score was the most utilised patient-reported function measure (n=11). Patient satisfaction was reported by eighteen studies but no single method was used consistently. Range of movement was the most frequent physical measure and was reported in all 91 studies. However, the methods of measurement and reporting varied, with seventeen different techniques being used. Other physical measures included grip and pinch strength and sensibility, again with variations in measurement protocols. The mean follow-up time ranged from 2 weeks to 17 years. Conclusions: There is little consistency in the reporting of outcomes for interventions in patients with Dupuytren’s disease, making it impossible to compare the efficacy of different treatment modalities. Although there are limitations to the existing generic patient reported outcomes measures, a combination of these together with a disease-specific questionnaire, and physical measures of active and passive individual joint Range of movement (ROM), grip and sensibility using standardised protocols should be used for future outcomes studies. As Dupuytren’s disease tends to recur following treatment as well as extend to involve other areas of the hand, follow-up times should be standardised and designed to capture both short and long term outcomes
Calcium-dependent conformational changes of membrane-bound Ebola fusion peptide drive vesicle fusion
The fusogenic subdomain of the Ebola virus envelope glycoprotein is an internal sequence located ca. 20 residues downstream the N‐terminus of the glycoprotein transmembrane subunit. Partitioning of the Ebola fusion peptide into membranes containing phosphatidylinositol in the absence of Ca2+ stabilizes an α‐helical conformation, and gives rise to vesicle efflux but not vesicle fusion. In the presence of millimolar Ca2+ the membrane‐bound peptide adopts an extended β‐structure, and induces inter‐vesicle mixing of lipids. The peptide conformational polymorphism may be related to the flexibility of the virus-cell intermembrane fusogenic complex
Exacerbated grassland degradation and desertification in Central Asia during 2000-2014.
Grassland degradation and desertification is a complex process, including both state conversion (e.g., grasslands to deserts) and gradual within-state change (e.g., greenness dynamics). Existing studies hardly separated the two components and analyzed it as a whole based on time series vegetation index data, which cannot provide a clear and comprehensive picture for grassland degradation and desertification. Here we propose an integrated assessment strategy, by considering both state conversion and within-state change of grasslands, to investigate grassland degradation and desertification process in Central Asia. First, annual maps of grasslands and sparsely vegetated land were generated to track the state conversions between them. The results showed increasing grasslands were converted to sparsely vegetated lands from 2000 to 2014, with the desertification region concentrating in the latitude range of 43-48° N. A frequency analysis of grassland vs. sparsely vegetated land classification in the last 15 yr allowed a recognition of persistent desert zone (PDZ), persistent grassland zone (PGZ), and transitional zone (TZ). The TZ was identified in southern Kazakhstan as one hotspot that was unstable and vulnerable to desertification. Furthermore, the trend analysis of Enhanced Vegetation Index during thermal growing season (EVITGS ) was investigated in individual zones using linear regression and Mann-Kendall approaches. An overall degradation across the area was found; moreover, the second desertification hotspot was identified in northern Kazakhstan with significant decreasing in EVITGS , which was located in PGZ. Finally, attribution analyses of grassland degradation and desertification were conducted by considering precipitation, temperature, and three different drought indices. We found persistent droughts were the main factor for grassland degradation and desertification in Central Asia. Considering both state conversion and gradual within-state change processes, this study provided reference information for identification of desertification hotspots to support further grassland degradation and desertification treatment, and the method could be useful to be extended to other regions
The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children
<p>Abstract</p> <p>Background</p> <p>The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders.</p> <p>Objective</p> <p>The aim of this study was to explore the association of <it>Trichuris trichiura </it>and <it>Ascaris lumbricoides </it>infections with wheezing and atopy in early childhood.</p> <p>Study design</p> <p>A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations <it>(Dermatophagoides pteronyssinus, Blomia tropicalis </it>and common child food), as well as against <it>A. lumbricoides </it>antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations.</p> <p>Results</p> <p>Active <it>T. trichiura </it>infection but not <it>A. lumbricoides </it>infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-<it>A. lumbricoides </it>IgE antibodies, but not current <it>A. lumbricoides </it>infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non-atopic children [adjusted OR = 3.07; CI = 1.13;8.35] and it was also associated with atopy [adjusted OR = 7.29; CI = 3.90; 13.4]. On the other hands, reports of wheezing were not significantly associated with atopy.</p> <p>Conclusions</p> <p>These data corroborate previous studies showing that wheezing is predominantly associated with infection in early childhood and shows that anti-<it>A. lumbricoides </it>IgE antibodies, but not active <it>Ascaris </it>infections, are associated with wheezing and atopy. Additionally, the data demonstrate that <it>T. trichiura </it>infection may play a role in the pathogenesis of atopic wheezing in early childhood.</p
The 2013 face recognition evaluation in mobile environment
Automatic face recognition in unconstrained environments is a challenging task. To test current trends in face recognition algorithms, we organized an evaluation on face recognition in mobile environment. This paper presents the results of 8 different participants using two verification metrics. Most submitted algorithms rely on one or more of three types of features: local binary patterns, Gabor wavelet responses including Gabor phases, and color information. The best results are obtained from UNILJ-ALP, which fused several image representations and feature types, and UC-HU, which learns optimal features with a convolutional neural network. Additionally, we assess the usability of the algorithms in mobile devices with limited resources. © 2013 IEEE
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