44 research outputs found

    Extraction and characterization of nanocellulose from three types of palm residues

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    Carbon footprint and nonrenewability are among the motives to mitigate dependence on oil resources. On the other hand, palm trees exceeded 100 million around globe, which poses enormous amount of biowastes to get exploited per annum. Moreover, nanocellulose is emerging as efficient low cost material, which shows increasing versatility throughout time. In this investigation we will attempt to extract nanocellulose from palm wastes (fronds, leaves, and coir), and characterize them. Dry biomass was pulped by being subjected to 10% (wt/wt) NaOH alkaline treatment at 160 C for 2 h. Pulped non-bleached biomass underwent acidic hydrolysis by mechanical stirring in 20% H2SO4 (v/v) and heating to 120 C for 30 min. After filtration, neutralization, and centrifugion, resultant particles were characterized to assess their morphology, size, particle charge, existing chemical groups, and crystallinity. For the three types of palm residues, our preparation technique was successful to isolate lignin containing nanocellulose particles. However, coir was more recalcitrant to acidic hydrolysis than fronds and leaves. Our palm residues yielded 42 e82 nm spherical particles, and zeta potential ranging between 11 and 19 mV. Crystallinity was higher after pulping, and lower after hydrolysis, which suggests promotion of amorphous content of cellulose. Lignin-containing nanocellulose prepared in this study initiates promising horizon especially in heavy metal (cations) removal from water in environmental applications and sustained drug delivery for medical applications.European Commissio

    Spanish Poplar Biomass as a Precursor for Nanocellulose Extraction

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    The effect of acidic hydrolysis duration on nanocellulose size, morphology, and proper ties was investigated, which opens up a whole new horizon of versatility in poplar applications. This study aimed to examine Spanish poplar wastes as raw material to extract crystalline nanocellulose (CNC), which substantiates the importance of poplar wastes. Wastes were pulped using 1 L of 10% NaOH (wt./wt.) solution, and bleached several times by NaClO2 ; afterwards, white wastes were subjected to acidic hydrolysis by 60% H2SO4 for either 5, 10, or 15 min. Microcrystalline cellulose (MCC) underwent a similar hydrolysis protocol as poplar as control. TEM, IR, and XRD characterization techniques were performed. Poplar based nanocellulose sized 219 nm length and 69 nm width after 15 min acidic hydrolysis. MCC yielded 122 nm length and 12 nm width crystals after 10 min acidic hydrolysis. Hydrolysis resulted in a drastic change and intense peaks at 3500 and 2900 cm−1 for nanocellulose. Although pre-hydrolysis fiber treatment was not influencial on the crystallinity of poplar, acidic hydrolysis remarkably raised the crystallinity index (CI) by 7–8%. The more hydrolysis duration was prolonged, the size of the resulting crystal (whisker) decreased, and the aspect ratio increased. Hydrolysis was more impactful on MCC than poplar. However, for future work, it seems that longer duration of pulping and bleaching could have significantly removed unwanted components (hemicellulose and lignin), showcased in IR and XRD, and hence smoothened the following hydrolysis.European Union under umbrella of Erasmus+ KA107 PhD Mobility schem

    Magnesium Exchanged Zirconium Metal−Organic Frameworks with Improved Detoxification Properties of Nerve Agents

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    UiO-66, MOF-808 and NU-1000 metal-organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)2(MeOH)2]4 related to their pore accessibility. Microporous UiO-66 remains unchanged while mesoporous MOF-808 and hierarchical micro/mesoporous NU-1000 materials yield doped systems containing exposed MgZr5O2(OH)6 clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P-F and P-S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions

    Steering a Tractor by Means of an EMG-Based Human-Machine Interface

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    An electromiographic (EMG)-based human-machine interface (HMI) is a communication pathway between a human and a machine that operates by means of the acquisition and processing of EMG signals. This article explores the use of EMG-based HMIs in the steering of farm tractors. An EPOC, a low-cost human-computer interface (HCI) from the Emotiv Company, was employed. This device, by means of 14 saline sensors, measures and processes EMG and electroencephalographic (EEG) signals from the scalp of the driver. In our tests, the HMI took into account only the detection of four trained muscular events on the driver’s scalp: eyes looking to the right and jaw opened, eyes looking to the right and jaw closed, eyes looking to the left and jaw opened, and eyes looking to the left and jaw closed. The EMG-based HMI guidance was compared with manual guidance and with autonomous GPS guidance. A driver tested these three guidance systems along three different trajectories: a straight line, a step, and a circumference. The accuracy of the EMG-based HMI guidance was lower than the accuracy obtained by manual guidance, which was lower in turn than the accuracy obtained by the autonomous GPS guidance; the computed standard deviations of error to the desired trajectory in the straight line were 16 cm, 9 cm, and 4 cm, respectively. Since the standard deviation between the manual guidance and the EMG-based HMI guidance differed only 7 cm, and this difference is not relevant in agricultural steering, it can be concluded that it is possible to steer a tractor by an EMG-based HMI with almost the same accuracy as with manual steering

    Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications

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    Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.This work was supported by the Instituto de Salud Carlos III (ISCIII) of the Spanish Ministry of Health (FIS; PI16/00425 and PI19/00321), Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER, 06/07/0036), IIS-FJD BioBank (PT13/0010/0012), Comunidad de Madrid (CAM, RAREGenomics Project, B2017/BMD-3721), European Regional Development Fund (FEDER), the Organización Nacional de Ciegos Españoles (ONCE), Fundación Ramón Areces, Fundación Conchita Råbago and the University Chair UAM-IIS-FJD of Genomic Medicine. Irene Perea-Romero is supported by a PhD fellowship from the predoctoral Program from ISCIII (FI17/00192). Ionut F. Iancu is supported by a grant from the Comunidad de Madrid (CAM, PEJ-2017-AI/BMD7256). Marta del Pozo-Valero is supported by a PhD grant from the Fundación Conchita Råbago. Berta Almoguera is supported by a Juan Rodes program from ISCIII (JR17/00020). Pablo Minguez is supported by a Miguel Servet program from ISCIII (CP16/00116). Marta Corton is supported by a Miguel Servet program from ISCIII (CPII17/00006). The funders played no role in study design, data collection, data analysis, manuscript preparation and/or publication decisions

    The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

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    The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033

    Improving hydrogen production from the hydrolysis of ammonia borane by using multifunctional catalysts

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    A novel multifunctional catalytic system has been developed for efficient hydrogen generation through the hydrolysis of ammonia borane. This system combines Pd NPs with acid sites and amines, which are both task-specific functionalities able to destabilize the N → B dative bond. The acidity of the support (zeolites of different structure and SiO2/Al2O3 ratio) used to disperse the Pd NPs causes an increase in the hydrogen production rate. However, the positive effect of incorporating p-phenylenediamine in the catalyst is much more pronounced, causing a two-fold increase in the activity of the catalyst. The combined effect of the different functionalities yields excellent performance in the hydrolysis of ammonia borane, greatly enhancing the activity of the metal-based catalyst and reducing the activation energy of the catalyzed reaction.The authors wish to thank the University of Alicante for financial support under the project GRE15-07. E.S. and N.L. acknowledge the University of Alicante, through the “Programa de Retención de Talento” (ref. UATALENTO16-03 and UATALENTO17-05, respectively)

    MOF/polymer hybrids through in situ free radical polymerization in metal-organic frameworks

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    We use the free radical polymerization initiator 4,4â€Č-azobis(cyanovaleric acid) coordinated to the open metal sites of metal-organic frameworks (MOFs) to give rise to highly uniform MOF/polymer hybrids. We demonstrate this strategy on two robust zirconium MOFs (NU-1000 and MOF-808), which are the most effective catalysts for degradation of chemical warfare nerve agents. The resulting hybrid materials maintain their hydrolytic catalytic activity and have substantially improved adhesion to polypropylene and activated carbon textile fibers, yielding highly robust MOF/polymer/textile hybrid systems. These composites are suitable for the green production of active protective clothing and filters capable of detoxifying organophosphorus warfare agents

    Stable production of peptide antigens in transgenic tobacco chloroplasts by fusion to the p53 tetramerisation domain

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    7 p., 3 figures and bibliographyThe production of short peptides as single molecules in recombinant systems is often limited by the low stability of the foreign peptide. In the plant expression system this problem has been solved by translational fusions to recombinant proteins that are highly stable or are able to form complex structures. Previously, we demonstrated that the highly immunogenic 21 amino acid peptide 2L21, which is derived from the canine parvovirus (CPV) VP2 protein, did not accumulate in transgenic tobacco chloroplasts. In this report, we translationally fused the 2L21 peptide to the 42 amino acid tetramerisation domain (TD) from the human transcription factor p53. The chimaeric 2L21-TD protein was expressed in tobacco chloroplasts. Leaves accumulated high levels of the recombinant protein (up to 0.4 mg/g fresh weight of leaf material, equivalent to ~6% of total soluble protein; 2% considering only the 2L21 peptide). The 2L21-TD protein was able to form tetramers in the stroma of the chloroplast. Mice immunised intraperitoneally with partially purified leaf extracts containing the 2L21-TD protein developed specific antibodies with titres similar to those elicited by a previously reported fusion between 2L21 and the B subunit of the cholera toxin. Mouse sera were able to detect both the 2L21 synthetic peptide and the CPV VP2 protein, showing that the antigenicity of the 2L21 epitope was preserved in the chimaeric protein. These results demonstrate that the p53 TD can be used as a carrier molecule for the accumulation of short peptides (such as 2L21) in the chloroplast without altering the immunogenic properties of the peptide.This work was partially supported by Grant BIO2005-00155 from the Ministerio de EducaciĂłn y Ciencia (Spain).Peer reviewe
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