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1.
Chemosphere ; 362: 142609, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38878980

ABSTRACT

This paper presents the results of a research aimed at establishing a novel method for the detection of primary and secondary micro- and nanoplastics (MNPs), by using the fluorescence properties of the dye Nile Red-n-heptane (NR-H). The method has been applied to the detection of laboratory degraded polymers (Polystyrene, PS and Polyethylene Terephthalate, PET) as well as traceable latex microspheres in aqueous environments, showing a remarkable detection capacity and avoiding the prior extraction or processing of MNPs in natural samples, with significant time savings compared to conventional methods. The study has been carried out on various types of water, including samples from wastewater treatment plants, boreholes, seawater and synthesized seawater. The effectiveness of the staining process was evaluated by scanning electron microscopy (SEM), dynamic light scattering (DLS) and optical microscopy. As a result, a novel standardizable protocol for the rapid detection of MNPs has been established, with the potential to improve environmental protection through fast in-situ detection and identification of plastic contaminants. The limitations of the protocol in the quantification of MNPs have also been identified and further studies are proposed to overcome these limitations.

2.
Membranes (Basel) ; 13(7)2023 Jul 11.
Article in English | MEDLINE | ID: mdl-37505026

ABSTRACT

This scientific publication presents a novel modification of the liquid-liquid displacement porosimetry (LLDP) method, aiming for the non-destructive automated analysis of water purification membrane filtration devices in the microfiltration (MF) and ultrafiltration (UF) range. The technical adaptation of LLDP enables the direct in-line porosimetric analysis of commercial filtration devices, avoiding the filtration devices' destruction. Six commercially available filtration devices with polyethersulfone (PES) and polysulfone (PS) membranes were studied using an improved device developed by the IFTS, which was based on a commercial LLDP instrument. The filtration devices were evaluated in three different configurations: flat disks, hollow fibers, and pleated membranes. The results obtained using the proposed method were compared with other characterization techniques, including submicronic efficiency retention, image analysis of scanning electron microscopy (SEM), and gas-liquid displacement porosimetry (GLDP). The comparison of the results demonstrated that the proposed method accurately determined the porosimetric characteristics of the filters. It proved to be a precise technique for the non-destructive in-line evaluation of filter performance, as well as for periodic quality control and the fouling degree assessment of commercial filtration devices. This modified LLDP approach offers significant potential for the advanced characterization and quality assessment of water purification membrane filtration devices, contributing to improved understanding and optimization of their performance.

3.
Membranes (Basel) ; 12(2)2022 Feb 11.
Article in English | MEDLINE | ID: mdl-35207133

ABSTRACT

This works aims to study the porous characterization of several commercial Gas Diffusion Layers (GDL). Three carbon-based porous GDL featuring a highly rigid microstructure of interconnected pores of several manufacturers were analyzed. Gas Liquid Displacement Porometry (GLDP) and Liquid Extrusion Porometry (LEP) have been used to obtain their pore size distributions (PSD) and the mean and mode pore diameters (davg and dmod), by means of a gas/liquid and extrusion porometer developed at IFTS. N-dodecane liquid has been used to completely wet the GDL's assuring penetration of the liquid into the carbon fibrous structure. The results demonstrated the accuracy of the setup on characterizing GDL in the Particle Filtration (PF) range by GLDP and LEP, with reasonable agreements of resulting PSD and average sizes between both techniques when GLDP and LEP results are compared. Differences can be explained in terms of the high pore connectivity of these kinds of structures.

4.
Membranes (Basel) ; 11(11)2021 Oct 24.
Article in English | MEDLINE | ID: mdl-34832037

ABSTRACT

The following review aims at analyzing the contribution of Spanish researchers to membrane science and technology, with a historical compilation of the main milestones. We used a bibliometric analysis based on the Scopus database (1960-2020) dealing with 8707 documents covering the different disciplines and subject areas where membranes are involved. Furthermore, the information has been updated to the present moment of writing this manuscript in order to include the latest research lines and the different research groups currently active in Spain, which may lead the way to the development of the field in the coming years.

5.
Membranes (Basel) ; 10(12)2020 Nov 25.
Article in English | MEDLINE | ID: mdl-33255821

ABSTRACT

This works aims to propose and demonstrate the accuracy of a novel method of characterization aimed for non-destructive analysis of microfiltration (MF) membrane cartridges. The method adapts conventional liquid-liquid displacement porosimetry (LLDP) for performing an in-line porosimetric analysis of the membrane cartridges, getting their pore size distributions (PSDs) and mean pore diameters (davg). Six commercial filtration cartridges featuring polyethersulfone (PES) pleated membranes were analyzed using a newly designed filtration rig, based on the liquid-liquid displacement porometer, developed at the Institut de la Filtration et des Techniques Séparatives (IFTS) and operated at constant flow. The experimental rig allows the direct and non-destructive characterization of the cartridge in its original presentation. Results have been compared with those obtained by using gas-liquid displacement porosimetry (GLDP) on small membrane coupons detached from such cartridges. The comparison allows us to conclude that the proposed method gives enough accuracy in the determination of porosimetric characteristics of the filters. This method can be used as a precise characterization technique for a non-destructive in-line study of filter performance and can be envisaged as useful to periodic quality or fouling control of the commercial cartridges.

6.
Polymers (Basel) ; 11(10)2019 Oct 15.
Article in English | MEDLINE | ID: mdl-31618983

ABSTRACT

A commercial ultrafiltration (UF) membrane (HFM-183 de Koch Membrane Systems) made of poly(vinylidene fluoride) (PVDF), was recovered with a negatively-charged polyelectrolyte (poly(sodium 4-styrenesulfonate)) (PSS), and the effects on its electric, chemical, and morphological properties were analyzed. Atomic force microscopy (AFM), liquid-liquid displacement porometry, Electrical Impedance Spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to investigate the modifications induced by the deposition of PSS on the PVDF positively-charged membrane and after its treatment by a radio frequency Ar-plasma. These techniques confirmed a real deposition and posterior compaction of PSS with increasing roughness and decreasing pore sizes. The evolution of the electric resistances of the membranes confirmed crosslinking and compaction with shielding of the sulfonated groups from PSS. In this way, a membrane with a negatively-charged active layer and a pore size which was 60% lower than the original membrane was obtained. The composition of the additive used by manufacturers to modify PVDF to make it positively charged was obtained by different procedures, all of which depended upon the results of X-ray photoelectron spectroscopy, leading to fairly consistent results. This polymer, carrying positive charges, contains quaternary nitrogen, as confirmed by XPS. Moreover, Raman spectroscopy confirmed that PVDF changes from mostly the to the α phase, which is more stable as a substrate for the deposited PSS. The aim of the tested modifications was to increase the retention of divalent anions without reducing permeability.

7.
BMC Neurol ; 17(1): 80, 2017 Apr 21.
Article in English | MEDLINE | ID: mdl-28431564

ABSTRACT

BACKGROUND: In randomised studies, the capsaicin 8% patch has demonstrated effective pain relief in patients with peripheral neuropathic pain (PNP) arising from different aetiologies. METHODS: ASCEND was an open-label, non-interventional study of patients with non-diabetes-related PNP who received capsaicin 8% patch treatment, according to usual clinical practice, and were followed for ≤52 weeks. Co-primary endpoints were percentage change in the mean numeric pain rating scale (NPRS) 'average daily pain' score from baseline to the average of Weeks 2 and 8 following first treatment; and median time from first to second treatment. The primary analysis was intended to assess analgesic equivalence between post-herpetic neuralgia (PHN) and other PNP aetiologies. Health-related quality of life (HRQoL, using EQ-5D), Patient Global Impression of Change (PGIC) and tolerability were also assessed. RESULTS: Following first application, patients experienced a 26.6% (95% CI: 23.6, 29.62; n = 412) reduction in mean NPRS score from baseline to Weeks 2 and 8. Equivalence was demonstrated between PHN and the neuropathic back pain, post-operative and post-traumatic neuropathic pain and 'other' PNP aetiology subgroups. The median time from first to second treatment was 191 days (95% CI: 147, 235; n = 181). Forty-four percent of all patients were responders (≥30% reduction in NPRS score from baseline to Weeks 2 and 8) following first treatment, and 86.9% (n = 159/183) remained so at Week 12. A sustained pain response was observed until Week 52, with a 37.0% (95% CI: 31.3, 42.7; n = 176) reduction in mean NPRS score from baseline. Patients with the shortest duration of pain (0-0.72 years) experienced the highest pain response from baseline to Weeks 2 and 8. Mean EQ-5D index score improved by 0.199 utils (responders: 0.292 utils) from baseline to Week 2 and was maintained until Week 52. Most patients reported improvements in PGIC at Week 2 and at all follow-up assessments regardless of number of treatments received. Adverse events were primarily mild or moderate reversible application site reactions. CONCLUSION: In European clinical practice, the capsaicin 8% patch provided effective and sustained pain relief, substantially improved HRQoL, improved overall health status and was generally well tolerated in a heterogeneous PNP population. TRIAL REGISTRATION: NCT01737294 Date of registration - October 22, 2012.


Subject(s)
Analgesics/administration & dosage , Capsaicin/administration & dosage , Neuralgia/drug therapy , Sensory System Agents/administration & dosage , Adult , Analgesics/adverse effects , Capsaicin/adverse effects , Female , Humans , Male , Middle Aged , Pain Management , Pain Measurement , Quality of Life , Sensory System Agents/adverse effects , Transdermal Patch , Treatment Outcome
8.
Toxicology ; 278(1): 101-11, 2010 Nov 28.
Article in English | MEDLINE | ID: mdl-19857542

ABSTRACT

The efficacy of long-term intake of a novel functional food supplement Funciona™ containing vitamins and juiced fruits was evaluated in order to assess the net effect of physical activity and antioxidant potentials in healthy older adult population. The long-term (2 years) and large-scale (400 older adult subjects) interventional study was based on both moderate-intensity exercise practice and concurrent supplementation. Sustained exercise-induced oxidative stress as reflected in significantly increased blood thiobarbituric acid-reactive substances (TBARS) (+15%), protein carbonyl groups (PC) (+18%) and oxidized glutathione (GSSG) (+112%) concentrations, and leukocyte 8-OHdG contents (23%). Exercise decreased the reduced/oxidized glutathione (GSH/GSSG) molar ratio (-43%) and plasma vitamin C levels (-22%). Supplementation with Funciona™ was significant in preventing oxidative damage to lipid, protein and DNA, and normalizing blood GSSG, GSH/GSSG and vitamin C levels. Thus daily intake of the antioxidant functional beverage counteracts the exercise-induced oxidative stress in free-living older subjects, and might be necessary to restore impaired antioxidant balance due long-term regular exercise.


Subject(s)
Antioxidants/pharmacology , Dietary Supplements , Oxidative Stress/drug effects , Physical Exertion/physiology , 8-Hydroxy-2'-Deoxyguanosine/analogs & derivatives , Aged , Aged, 80 and over , Ascorbic Acid/blood , Cohort Studies , Eating/physiology , Female , Glutathione/blood , Guanine/analogs & derivatives , Guanine/blood , Humans , Male , Middle Aged , Oxidative Stress/physiology , Protein Carbonylation/physiology , Thiobarbituric Acid Reactive Substances/metabolism
9.
Biofactors ; 27(1-4): 167-83, 2006.
Article in English | MEDLINE | ID: mdl-17012773

ABSTRACT

Free radicals and oxidative stress are involved in the pathogenic mechanisms of cardiovascular disease (CVD), diabetes and cancer. Exercise is a useful strategy for preventing CVD but in elderly persons it can enhance oxidative stress, which is why some studies recommend antioxidant supplementation for exercising elderly subjects. This intervention study was performed on 320 elderly subjects following a Geriatric Revitalization Program (GEREPRO) to maintain physical health and reduce CVD risk. GEREPRO was based on regular exercise concurrent with a nutritional antioxidant treatment based on daily intake of a functional antioxidant food, Biofrutas. Sustained exercise (10 months, 3 sessions/week) significantly increased cardiorespiratory fitness and plasma HDL-cholesterol; it reduced some predictors of cardiovascular risk (arterial pressure, LDL-cholesterol, total cholesterol/LDL-C, LDL-C/HDL-C), but significantly enhanced some biomarkers of oxidative stress. Concurrent antioxidant supplementation did not produce any ergogenic effects but, meaningfully, enhanced some positive effects of exercise on physical health and the CDV risk index, and it totally prevented the exercise-induced oxidative stress. Our results show that regular and moderate exercise improves cardiorespiratory function and reduces CVD risk in elderly people, while concurrent antioxidant supplementation modulates oxidative insult during exercise in the elderly and enhances the beneficial effects of exercise.


Subject(s)
Antioxidants/pharmacology , Cardiovascular Diseases/prevention & control , Exercise/physiology , Oxidative Stress/physiology , Aged , Aged, 80 and over , Antioxidants/therapeutic use , Blood Pressure/drug effects , Cardiovascular Diseases/blood , Cardiovascular Diseases/physiopathology , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Dietary Supplements , Female , Humans , Lipid Metabolism/drug effects , Lipids/blood , Male , Middle Aged , Risk Factors , Treatment Outcome , Vitamins/pharmacology , Vitamins/therapeutic use
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