2,066 research outputs found
Optimization of Ultrasound Assisted Extraction of Bioactive Compounds from Apple Pomace
In the present work, the optimization of the extraction of antioxidant compounds from apple pomace using ultrasound technology as an environmentally friendly and intensification process was developed. Different sonication powers, extraction temperatures and extraction times were studied and their influence on extraction yield and characteristics of the extracted samples (total phenolic compounds, flavonoid content and antioxidant capacity) are presented. The elaborated experimental design and the analysis of Pareto and response surface diagrams allowed us to determine the optimal extraction conditions. The conditions that allow the maximum extraction of phenolic compounds were found at 20 min, 90 °C and 50% ultrasound amplitude. Nevertheless, at these conditions, the antioxidant capacity measured by DPPH decreased in the extracted samples.This research was funded by Diputación Foral de Gipuzcoa, Departamento de Promoción económica, Turismo y Medio Rural, Proyecto Fortalecimiento-96, grant number LEHIAKORTASUNA INDARTZEA-97/18
Optimisation of lignin liquefaction with polyethylene glycol/ glycerol through response surface methodology modelling
In order to diminish the dependence on oil lignin, which is the most abundant biopolymer of phenolic origin on Earth and can be utilised in different industrial endeavours, such as, the production of polyurethanes. In this study, hardwood (Eucalyptus globulus) and softwood (Pinus radiata) organosolv lignins were employed to produce bio-polyols trough microwave-assisted liquefaction. The resulting bio-polyols possessed specific properties to be employed in the synthesis of rigid and elastic polyurethanes. The values of the reaction parameter were optimized using response surface methodology to determine the most effective conditions for producing bio-polyols from both types of lignins for the purpose of rigid and elastic polyurethane formulation. The effect of catalyst concentration (%wt.), temperature (ºC) and Polyethylene glycol/Glycerol weight ratio on the molecular weight (Mw) and hydroxyl number (IOH) of bio-polyols was evaluated. The optimum reaction conditions of bio-polyols production for rigid polyurethanes were virtually equal for the two lignins, 159–161 ºC, Polyethylene glycol/Glycerol ratio of 3 without catalyst. On the contrary, the bio-polyols for elastic polyurethanes required different reaction parameters depending on the lignin used. For hardwood lignin the optimised conditions were 180 ºC, 7.57 (Polyethylene glycol/Glycerol ratio) and 5.00% of catalyst while for softwood lignin were 160 ºC, 7.34 (Polyethylene glycol/Glycerol) and 3.85% of catalyst. Additionally, the bio-polyols obtained at optimised conditions were fully characterised and acid number, polydispersity index, functionality and the rheological behaviour was studied.The authors would like to acknowledge the financial support of the University of the Basque Country (project COLAB20/04). F.Hernández-Ramos would like to acknowledge the Grant received from the Environmental Department of the Diputación Foral de Gipuzkoa. The authors thank SGIker (UPV/EHU/ERDF, EU) for their technical and human support
Valorisation of crude glycerol in the production of liquefied lignin bio-polyols for polyurethane formulations
Bio-polyols, produced by liquefying lignin with polyhydric alcohols, offer a promising alternative to conventional polyols for polyurethane production. To enhance the sustainability on the production of these bio-polyols, this study proposes the use of crude glycerol and microwave-assisted liquefaction as substitutes for conventional methods and commercial glycerol. This approach reduces the energy requirements of the reaction while also adding value to this by-product. The synthesis of bio-polyols with suitable properties to produce elastic and rigid polyurethane was carried out using previously optimised reaction conditions. Organosolv lignins obtained from Eucalyptus globulus and Pinus radiata were employed, using polyethylene glycol and crude glycerol as solvents and sulphuric acid as a catalyst. Several parameters of the bio-polyols were analysed, including hydroxyl number (IOH), acid number (An), and functionality (f), suggesting that the bio-polyols were suitable for polyurethane synthesis. Bio-polyols formulated to produce rigid polyurethanes exhibited IOH values of 554 and 383 (mg KOH/g), An values of 1.91 and 4.21 (mg KOH/g), and functionalities of 4.16 and 3.14 for Eucalyptus globulus and Pinus radiata lignin. In the case of bio-polyols for elastic polyurethanes, the values were 228 and 173 (mg KOH/g) (IOH), 20.94 and 25.09 (mg KOH/g) (An), and functionalities of 3.51 and 2.08.The authors would like to acknowledge the financial support of the University of the Basque Country (project COLAB20/04). F. Hernández-Ramos would like to acknowledge the Grant received from the Environmental Department of the Diputación Foral de Gipuzkoa. The authors thank SGIker (UPV/EHU/ERDF, EU) for their technical and human support
Antioxidant, Antifungal and Phytochemical Investigations of Capparis spinosa L.
The antioxidant and antifungal activities of crude hydro-ethanolic extract from Capparis spinosa L. (Capparidaceae) leaves and their fractions, obtained by liquid-liquid extraction (LLE) using solvents with increasing polarity (hexane, diethyl ether, ethyl acetate, butanol, and water), were investigated. The crude extract and the obtained fractions were characterized by colorimetric analysis, pyrolysis-gas chromatography (GC)-mass spectroscopy (MS), Fourier Transform Infrared Spectroscopy, and their antioxidant and antifungal capacity were determined. It was observed that the ethyl acetate fraction was enriched in polyphenols, the butanol fraction resulted in purified from proteins and the residual aqueous fraction contains more hydrophobic compounds. The evaluation of the antioxidant activity revealed that the ethyl acetate fraction possesses an interesting capacity 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging with a percentage of inhibition of 84.02% at a concentration of 2 mg/mL and better ferric reducing antioxidant power (FRAP) 4.275 ± 0.011 mmol/g of dry sample than the other fractions tested. Regarding the antifungal activity, the diethyl ether fraction showed the highest activity against Aspergillus niger with 58.78% of inhibition. The results obtained in this work showed the relevance of the valorization of the leaves of Capparis spinosa L., given its richness in bioactive molecules can be regarded as a natural source of antioxidant and antifungal and may be considered in the future to replace synthetic preservatives in food, pharmaceutic products and cosmetic.This research was funded by University of Basque Country, grant number PES20/38 and “The APC was funded by University of Basque Country”
Life Cycle Assessment of various biorefinery approaches for the valorisation of almond shells
In the near future, sustainable and efficient biorefineries would be essential for the production of commodity chemicals and high-added value compounds. Therefore, in this work, six scenarios differing on the delignification steps and cellulose conversion routes were assessed via Life Cycle Assessment methodology in order to study the environmental impacts derived from the conversion of an abundant agricultural residue (almond shells) into high added-value products and select the most suitable one for large-scale valorisation. The assessments were conducted employing experimental results and processing them by SimaPro software. The main conclusion achieved suggested that the enzymatic hydrolysis of the solid from any delignification step entailed the highest environmental impacts and had the highest relative contribution in all the studied impact categories with a maximum of 74%, which was ascribed to Scenario 5. It was also concluded that the organosolv delignification process affected overall more negatively than the alkaline treatment having bigger impacts especially in abiotic depletion (ADP) and photochemical oxidation (POP) categories. Finally, it can be stated that the best route for valorising the almond shell in a biorefinery facility is composed of autohydrolysis (common for every scenario), alkaline delignification, bleaching and acid hydrolysis steps for the obtaining of oligosaccharides, lignin and nanocrystals as products.Authors want to acknowledge the University of the Basque Country UPV/EHU, as well as the Spanish Ministry of Science and Innovation (CTQ2016-78689-R) for supporting financially this research. L.S. and R.F. would like to acknowledge the Departmentof Economic Development and Infrastructures of the Basque Government (scholarship of young researchers training) . A.M. and I.D, would like to thank the University of the Basque Country (Training of Researcher Staff, PIF17/207 and grant reference DOCREC19/47, respectively)
Eco-friendly isolation and characterization of nanochitin from different origins by microwave irradiation: optimization using response surface methodology
[EN] The extraction of nanochitin from marine waste has attracted great industrial interest due to its unique properties,
namely biodegradability, biocompatibility and as a functional reinforcing agent. Conventional acid hydrolysis
isolation of nanochitin requires high temperatures and acid concentration, time and energy. Herein, for
the first time, microwave irradiation method was used as an eco-friendly approach to isolate nanochitin from
different sources. The isolation conditions were optimized through an experimental Box-Behnken design using
surface response methodology. The data showed optimal conditions of 1 M HCl, 10.00 min and 124.75 W to
obtain lobster nanocrystals; 1 M HCl, 14.34 min and 50.21 W to obtain shrimp nanocrystals; and 1 M HCl, 29.08
min and 54.08 W to obtain squid pen nanofibres, reducing time and HCl concentration. The obtained isolation
yields where of 85.30, 79.92 and 80.59 % for lobster, shrimp and squid, respectively. The morphology of the
nanochitins was dependent of the chitin origin, and the lengths of the nanochitins were of 314.74, 386.12 and >
900 nm for lobster, shrimp and squid pen, respectively. The thermal stability of the ensuing nanochitins was
maintained after treatment. The results showed that nanochitin could be obtained by using an eco-friendly
approach like microwave irradiation.The authors would like to thank the Basque Government (scholarship of young researchers training and project IT1008-16) for supporting financially this research and their gratitude for technical and human support provided by SGIker (UPV/EHU/ERDF, EU). S.C.M.F. is the recipient of an E2S UPPA Research Partnership Chair (MANTA: Marine Materials) supported by the “Investissements d’Avenir” French program managed by ANR (ANR-16-IDEX-0002), the R ́egion Nouvelle-Aquitaine and the Communaut ́e d’Agglom ́eration du Pays Basque, France
Cultural and socio-economic impacts of Mediterranean marine protected areas
Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socio-economic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natural benthic communities as a result of diver damage, mooring and the feeding of large fish by divers. Emphasis has been given in only a few MPAs to promoting public awareness of these impacts. Although the conservation of nature should be considered the fundamental objective of MPAs, neglecting their social, cultural and economic impacts has at times led to poor local consensus, if not hostility. We believe that planning and managing MPAs should be conducted on a multidisciplinary basis. Nonetheless, no single model can be considered valid for the whole Mediterranean. The very variable characteristics of coastal areas, from those of small uninhabited islands to those of cities, require different weightings to be assigned for each factor in order to achieve a durable equilibrium and realize the original objectives of each MPA. Only with such flexibility of management will it be possible to reach a greater understanding of the MPA system and create a lasting consensus in favour of conservation, a consensus which would mean an overwhelming majority of people actively avoiding damaging nature and preventing others from doing so.This paper was realized with funds from the EU CEC DGXII–MAST III contract number: MAS3-ct97–0155
Less than 10 percent of star formation in z=0.6 massive galaxies is triggered by major interactions
Both observations and simulations show that major tidal interactions or
mergers between gas-rich galaxies can lead to intense bursts of starformation.
Yet, the average enhancement in star formation rate (SFR) in major mergers and
the contribution of such events to the cosmic SFR are not well estimated. Here
we use photometric redshifts, stellar masses and UV SFRs from COMBO-17, 24
micron SFRs from Spitzer and morphologies from two deep HST cosmological survey
fields (ECDFS/GEMS and A901/STAGES) to study the enhancement in SFR as a
function of projected galaxy separation. We apply two-point projected
correlation function techniques, which we augment with morphologically-selected
very close pairs (separation <2 arcsec) and merger remnants from the HST
imaging. Our analysis confirms that the most intensely star-forming systems are
indeed interacting or merging. Yet, for massive (M* > 10^10 Msun) star-forming
galaxies at 0.4<z<0.8, we find that the SFRs of galaxies undergoing a major
interaction (mass ratios <1:4 and separations < 40 kpc) are only 1.80 +/- 0.30
times higher than the SFRs of non-interacting galaxies when averaged over all
interactions and all stages of the interaction, in good agreement with other
observational works.
We demonstrate that these results imply that <10% of star formation at 0.4 <
z < 0.8 is triggered directly by major mergers and interactions; these events
are not important factors in the build-up of stellar mass since z=1.Comment: Submitted to ApJ. 41 pages, 11 figure
Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study
Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak.
Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study.
Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM.
Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide
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