4,294 research outputs found

    Green synthesis of vanillin: Pervaporation and dialysis for process intensification in a membrane reactor

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    In the present work, two different membrane processes (pervaporation and dialysis) are compared in view of their utilization in a membrane reactor, where vanillin, which is probably the most important aroma of the food industry, is synthesized in a green and sustainable way. The utilized precursor (ferulic acid, which is possibly a natural product from agricultural wastes) is partially oxidized (photocatalytically or biologically) and the product is continuously recovered from the reacting solution by the membrane process to avoid its degradation. It is observed that pervaporation is much more selective towards vanillin than dialysis, but the permeate flux of dialysis is much higher. Furthermore, dialysis can work also at lower temperatures and can be used to continuously restore the consumed substrate into the reacting mixture. A mathematical model of the integrated process (reaction combined with membrane separation) reproduces quite satisfactorily the experimental results and can be used for the analysis and the design of the process

    Pulmonary embolism in COVID-19: Ventilation and perfusion computed tomography

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    This is an illustrated case about CT ventilation and perfusion in Covid patient

    Visible Light Induced Oxidation of Trans-ferulic Acid by TiO2 Photocatalysis

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    The oxidation of trans-ferulic acid (C 10H 10O 4) in aqueous TiO 2 dispersion occurs via the formation of a charge-transfer complex on the TiO 2 surface that is able to absorb visible light (\u3bb 65 400 nm). The main product is CO 2, whereas secondary oxidation products are organic species such as vanillin, caffeic acid, homovanillic acid, and vanillylmandelic acid. Oxidation through the formation of a charge-transfer complex occurs only in the presence of specific TiO 2 samples. Experiments in the absence of oxygen, in the presence of bromate ions and by using a phosphate-modified TiO 2, have been carried out for investigating the reaction mechanism. In order to study the interaction between trans-ferulic acid and TiO 2 surface and to characterize the charge-transfer complex, UV-Vis diffuse reflectance and FT-IR spectroscopies have been used. FT-IR characterization of TiO 2 samples in contact with the aqueous trans-ferulic acid solution indicates that the charge-transfer complex formation occurs via adsorption of bidentate ferulate species

    A new predictive technology for perinatal stem cell isolation suited for cell therapy approaches

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    The use of stem cells for regenerative applications and immunomodulatory effect is in-creasing. Amniotic epithelial cells (AECs) possess embryonic‐like proliferation ability and multipo-tent differentiation potential. Despite the simple isolation procedure, inter‐individual variability and different isolation steps can cause differences in isolation yield and cell proliferation ability, compromising reproducibility observations among centers and further applications. We investi-gated the use of a new technology as a diagnostic tool for quality control on stem cell isolation. The instrument label‐free separates cells based on their physical characteristics and, thanks to a micro-camera, generates a live fractogram, the fingerprint of the sample. Eight amniotic membranes were processed by trypsin enzymatic treatment and immediately analysed. Two types of profile were generated: a monomodal and a bimodal curve. The first one represented the unsuccessful isolation with all recovered cell not attaching to the plate; while for the second type, the isolation process was successful, but we discovered that only cells in the second peak were alive and resulted adherent. We optimized a Quality Control (QC) method to define the success of AEC isolation using the frac-togram generated. This predictive outcome is an interesting tool for laboratories and cell banks that isolate and cryopreserve fetal annex stem cells for research and future clinical applications

    Quali-Quantitative Analysis by LC/DAD and GPC of the Polyphenols ofUva Di Troia Canosina Grape Seeds for the Development of an IndustrialNutraceutical Product

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    The quali-quantitative determination of the principal components of "uva di Troia canosina" seed extracts by LC/ DAD analysis and the optimization of the extraction and purification processes for the development of an industrial nutraceutical product, are described. Two different fractions of seeds collected at different stages of fermentation were compared: "Tesi" 2 when there is a spontaneous stratification of the seeds at the bottom of the recipient and "Tesi" 4 at the end of fermentation. Percolation was applied and compared to maceration and the purification step carefully evaluated to obtain extracts free of contaminant species endowed with polyphenolic content comparable to commercial preparations such as Leucoselect® (Indena, SpA, Italy), Vitis Vinifera extract 95% (seeds), Vitis Vinifera dry extract 95%, Biovin grape seed and vinasse extract. (Farmalabor, Italy). In particular, "Tesi" 2 extract obtained by percolation and purified with a LLE extraction with ethyl acetate showed a polyphenolic content similar to Leucoselect®. From the quantitative analyses it was evident, as expected, that "Tesi"2 has a higher polyphenolic content compared to "Tesi" 4, because during vinification the must extracts polyphenols from the seeds. On the other hand, "Tesi" 4 is particularly convenient since it is easily obtained and very economical, being a waste product. The residual content of organic solvents (ethanol and ethyl acetate) and water was assessed in the grape extracts according to ICH rules by means respectively of HS/GC and Karl Fisher titration in order to meet the requirements for commercialization. Furthermore, the high molecular weight polyphenolic fraction of our extracts was investigated through gel permeation chromatography (GPC) and compared to that of Leucoselect®

    Corneal Biomechanical Response Alteration After Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment

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    Purpose: To compare the corneal biomechanics of eyes that underwent scleral buckle (SB) for rhegmatogenous retinal detachment (RRD) with those of fellow eyes (fellow eyes) and to further investigate the effects of SB on intraocular pressure (IOP) values. Design: Retrospective, fellow-eye matched cohort study. Methods: A total of 18 consecutive patients (11 males and 7 females) treated with SB for RRD in 1 eye were enrolled. Goldmann applanation tonometry was used to measure IOP. Biomechanical properties of the cornea were investigated by using the Ocular Response Analyzer (ORA) (Reichert Instruments) for the calculation of corneal resistant factor (CRF), corneal hysteresis, Goldmann-correlated IOP, and corneal-compensated IOP. Customized software was used for analysis of the ORA infrared and pressure signals, and a significance threshold was set to a P value of. 05. Results: Operated eyes (OEs) showed significantly lower values of corneal hysteresis and CRF than fellow eyes (9.0 ± 1.8 vs 10.1 ± 1.8 mm Hg, respectively; P < .001; 10.0 ± 2.2 vs 10.9 ± 2.2 mm Hg; P < .001). GAT was significantly lower than corneal-compensated IOP in OEs (18.1 ± 4.9 vs 19.8 ± 4.8 mm Hg, respectively; P = .022) but not in fellow eyes. The second applanation event (A2) took place earlier in time, and the cornea was moving faster during A2 in the OEs than in the fellow eyes. Conclusions: SB for the treatment of RRD affects corneal biomechanical response, likely due to a less compliant sclera that limits corneal motion and reduces energy dissipation, reflected in a lower corneal hysteresis. This has potentially meaningful clinical implications as the accuracy of the measurement of IOP values may be affected in these eyes

    Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster

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    Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle θ13\theta_{13} in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small L/EL/E, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current νμ\nu_{\mu} disappearance tension with νe\nu_e appearance and disappearance at the eV mass scale. Instead, a new CERN neutrino beam would allow a further span in the parameter space together with a refined control of systematics and, more relevant, the measurement of the antineutrino sector, by upgrading the spectrometer with detectors currently under R&D study.Comment: 76 pages, 52 figure
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