Catalytic Transformation of Nitroarenes to Amines over Ba(1-x)SrxTiO3 (0 < x < 1) Perovskites in Water.

This work is focused on the application of lanthanide-free perovskite Ba1-xSrxTiO3 (0 < x < 1) in valorization of toxic pollutants as 4-nitrophenol (4-NPh). The series of perovskites were fabricated by facile, one-step solid-state preparation method and characterized via various techniques: elemental analysis (Inductively Coupled Plasma Optical Emission Spectrometry, ICP-OES), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and dielectric properties (impedance spectroscopy, IS). The methods confirmed the assumed composition, structure and high purity of the materials. The results showed that substitution of Ba2+ by Sr2+ in the perovskite crystal lattice influenced the dielectric properties of samples and the size of the grains. The absorption and catalytic properties of Ba(1-x)SrxTiO3 (0 < x < 1) series were evaluated in reduction of 4-NPh in water using NaBH4 as reducing agent. No adsorption of 4-NPh was found for all the materials during 180 min of contact (experiment without reducing agent), and the best catalytic performance was found for the Ba(1-x)SrxTiO3 (x = 0.3) sample. The catalytic transformation of 4-NPh to 4-APh follows a pseudo-first-order model, and the catalysts can be easily regenerated via mild annealing (300 °C).

Ternary (molybdenum disulfide/graphene)/carbon nanotube nanocomposites assembled via a facile colloidal electrostatic path as electrocatalysts for the oxygen reduction reaction: Composition and nitrogen-doping play a key role in their performance.

Nanocomposites have garnered attention for their potential as catalysts in electrochemical reactions vital for technologies like fuel cells, water splitting, and metal-air batteries. This work focuses on developing three-dimensional (3D) nanocomposites through aqueous phase exfoliation, non-covalent functionalization of building blocks with surfactants and polymers, and electrostatic interactions in solution leading to the nanocomposites assembly and organization. By combining molybdenum disulfide (MoS2) layers with graphene nanoplatelets (GnPs) to form a binary 2D composite (MoS2/GnP), and subsequently incorporating multiwalled carbon nanotubes (MWNTs) to create ternary 3D composites, we explore their potential as catalysts for the oxygen reduction reaction (ORR) critical in fuel cells. Characterization techniques such as X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction elucidate material composition and structure. Our electrochemical studies reveal insights into the kinetics of the reactions and structure-activity relationships. Both the (MoS2/GnP)-to-MWNT mass ratio and nitrogen-doping of GnPs (N-GnPs) play a key role on the electrocatalytic ORR performance. Notably, the (MoS2/N-GnP)/MWNT material, with a 3:1 mass ratio, exhibits the most effective ORR activity. All catalysts demonstrate good long-term stability and methanol crossover tolerance. This facile fabrication method and observed trends offer avenues for optimizing composite electrocatalysts further.

Hybrid Zn-ß-Aminoporphyrin-Carbon Nanotubes: Pyrrolidine and Direct Covalent Linkage Recognition, and Multiple-Photo Response.

To unveil and shape the molecular connectivity in (metallo)porphyrin-carbon nanotube hybrids are of main relevance for the multiple medicinal, photoelectronic, catalytic, and photocatalytic applications of these materials. Multi-walled carbon nanotubes (MWCNTs) were modified through 1,3-dipolar cycloaddition reactions with azomethine ylides generated in situ and carrying pentafluorophenyl groups, followed by immobilization of the ß-amino-tetraphenylporphyrinate Zn(II). The functionalities were confirmed via XPS and FTIR, whereas Raman spectroscopy showed disruptions on the graphitic carbon nanotube surface upon both steps. The functionalization extension, measured via TGA mass loss and corroborated via XPS, was 0.2 mmol·g-1. Photophysical studies attest to the presence of the different porphyrin-carbon nanotube connectivity in the nanohybrid. Significantly different emission spectra and fluorescence anisotropy of 0.15-0.3 were observed upon variation of excitation wavelength. Vis-NIR absorption and flash photolysis experiments showed energy/charge transfer in the photoactivated nanohybrid. Moreover, evidence was found for direct reaction of amino groups with a carbon nanotube surface in the presence of molecular dipoles such as the zwitterionic sarcosine amino acid.

Graphene-Type Materials for the Dispersive Solid-Phase Extraction Step in the QuEChERS Method for the Extraction of Brominated Flame Retardants from Capsicum Cultivars.

A new application of graphene-type materials as an alternative cleanup sorbent in a quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure combined with GC-ECD/GC-MS/GC-MS/MS detection was successfully used for the simultaneous analysis of 12 brominated flame retardants in Capsicum cultivar samples. The chemical, structural, and morphological properties of the graphene-type materials were evaluated. The materials exhibited good adsorption capability of matrix interferents without compromising the extraction efficiency of target analytes when compared with other cleanups using commercial sorbents. Under optimal conditions, excellent recoveries were obtained, ranging from 90 to 108% with relative standard deviations of <14%. The developed method showed good linearity with a correlation coefficient above 0.9927, and the limits of quantification were in the range of 0.35-0.82 µg/kg. The developed QuEChERS procedure using reduced graphite oxide (rGO) combined with GC/MS was successfully applied in 20 samples, and the pentabromotoluene residues were quantified in two samples.

Unveiling the structural transformations of the PW11Co@ZIF-67 nanocomposite induced by thermal treatment.

A guest@host POM@ZIF nanocomposite-PW11Co@ZIF-67-has been synthesized using an in situ strategy. This new nanocomposite exhibits (i) individually ZIF-67-cage-confined POM units, (ii) structural defects in the ZIF-67 host induced by the POM, and (iii) charge transfer from the ZIF-67 to the confined POM. In addition, it has served as a template to produce a set of derived samples by applying thermal treatment at various temperatures (200, 400, 500, 600, and 950 °C) under a N2 flow. We have used multiple characterization techniques, ICP-OES, CHNS analysis, XPS, ATR-IR, PXRD, Raman spectroscopy, N2/CO2 adsorption analysis, CV, and TEM/EDS, to fully assess the thermally-induced variation tendencies. The first two derivatives-D200 and D400-show the same nanoarrangement as the PW11Co@ZIF-67 precursor, although with incipient signs of both POM and ZIF-67 structural decompositions. The following samples-D500, D600, and D950-exhibit a carbonaceous nature consisting of C-embedded compositionally complex nanoparticles that involve Co and W present as diverse species, metallic/oxide/phosphate/phosphide. D500 presents the best intrinsic electrochemistry, probably due to the high proportion of pyridinic N moieties doping its C matrix combined with small-sized and highly dispersed Co-enriched nanoparticles. This study focuses on the need for a thorough physicochemical characterization of this class of highly nanostructured materials with a view to exploring their application in electrocatalysis.

Clinical significance of baseline Pan-Immune-Inflammation Value and its dynamics in metastatic colorectal cancer patients under first-line chemotherapy.

Pan-Immune-Inflammation Value (PIV) has been recently proposed as a new blood-based prognostic biomarker in metastatic colorectal cancer (mCRC). Herein we aimed to validate its prognostic significance and to evaluate its utility for disease monitoring in patients with mCRC receiving first-line chemotherapy. We conducted a single-centre retrospective study involving 130 previously untreated mCRC patients under first-line standard chemotherapy in a real-world scenario. PIV was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count at three different time-points: baseline, week 4 after therapy initiation, and at disease progression. We analyzed the influence of baseline PIV on overall survival (OS), progression-free survival (PFS), disease control rate (DCR), and overall response rate (ORR). We also explored the utility of PIV dynamics for disease monitoring. Baseline PIV high was significantly associated with worse OS in univariate [hazard ratio (HR) = 2.10, 95% CI, 1.41-3.15; p = 0.000299] and multivariate (HR = 1.82, 95% CI, 1.15-2.90; p = 0.011) analyses. Baseline PIV was also associated with worse PFS in univariate (HR = 2.04, 95% CI, 1.40-2.97; p = 0.000187) and multivariate (HR = 1.56, 95% CI, 1.05-2.31; p = 0.026) analyses. Baseline PIV was not correlated either with DCR or ORR. Regarding PIV dynamics, there was a statistically significant increase from week 4 to disease progression (p = 0.0003), which was at the expense of cases with disease control as best response (p < 0.0001). In conclusion, this study validates the prognostic significance of baseline PIV in patients with mCRC receiving first-line standard chemotherapy in a real-world scenario. Moreover, it suggests the potential utility of PIV monitoring to anticipate the disease progression among those patients who achieve initial disease control.

Solar Light-Induced Methylene Blue Removal over TiO2/AC Composites and Photocatalytic Regeneration.

TiO2-containing photocatalysts, which combine TiO2 with carbon-based materials, are promising materials for wastewater treatment due to synergistic photodegradation and adsorption phenomena. In this work, TiO2/AC composites were produced by the in situ immobilization of TiO2 nanoparticles over activated carbon (AC) derived from spent coffee grains, using different TiO2/AC proportions. The TiO2/AC composites were tested as adsorbents (dark) and as photocatalysts in a combined adsorption+photocatalytic process (solar irradiation) for methylene blue (MB) removal from ultrapure water, and from a secondary effluent (SecEf) of an urban wastewater treatment plant. All the materials were characterized by XRD (X-ray powder diffraction), N2 adsorption-desorption isotherms at -196 °C, SEM (scanning electron microscopy), UV-Vis diffuse reflectance, FTIR (Fourier-transform infrared spectroscopy), TPD (temperature programmed desorption), XPS (X-ray photoelectron spectroscopy) and TGA (thermogravimetric analysis). The TiAC60 (60% C) composite presented the lowest band gap (1.84 eV), while, for TiAC29 (29% C), the value was close to that of bare TiO2 (3.18 vs. 3.17 eV). Regardless of the material, the solar irradiation improved the percentage of MB discolouration when compared to adsorption in dark conditions. In the case of simultaneous adsorption+photocatalytic assays performed in ultrapure water, TiAC29 presented the fastest MB removal. Nevertheless, both TiAC29 and TiAC60 led to excellent MB removal percentages (96.1-98.1%). UV-induced photoregeneration was a promising strategy to recover the adsorption capacity of the materials, especially for TiAC60 and AC (>95%). When the assays were performed in SecEf, all the materials promoted discolouration percentages close to those obtained in ultrapure water. The bulk water parameters revealed that TiAC60 allowed the removal of a higher amount of MB, associated with the overall improvement of the SecEf quality.

Progesterone Metabolism by Human and Rat Hepatic and Intestinal Tissue.

Following oral administration, the bioavailability of progesterone is low and highly variable. As a result, no clinically relevant, natural progesterone oral formulation is available. After oral delivery, first-pass metabolism initially occurs in the intestines; however, very little information on progesterone metabolism in this organ currently exists. The aim of this study is to investigate the contributions of liver and intestine to progesterone clearance. In the presence of NADPH, a rapid clearance of progesterone was observed in human and rat liver samples (t1/2 2.7 and 2.72 min, respectively). The rate of progesterone depletion in intestine was statistically similar between rat and human (t1/2 197.6 min in rat and 157.2 min in human). However, in the absence of NADPH, progesterone was depleted at a significantly lower rate in rat intestine compared to human. The roles of aldo keto reductases (AKR), xanthine oxidase (XAO) and aldehyde oxidase (AOX) in progesterone metabolism were also investigated. The rate of progesterone depletion was found to be significantly reduced by AKR1C, 1D1 and 1B1 in human liver and by AKR1B1 in human intestine. The inhibition of AOX also caused a significant reduction in progesterone degradation in human liver, whereas no change was observed in the presence of an XAO inhibitor. Understanding the kinetics of intestinal as well as liver metabolism is important for the future development of progesterone oral formulations. This novel information can inform decisions on the development of targeted formulations and help predict dosage regimens.

Evaluation of Rhodamine B Photocatalytic Degradation over BaTiO3-MnO2 Ceramic Materials.

Ferroelectric ceramics (BaTiO3_MnO2) with different Mn admixtures were prepared using solid-state synthesis. Elemental analysis, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and impedance spectroscopy confirmed that the BaTiO3 and MnO2 coexisted in the ceramics. In addition, the high purity and homogeneity of the element distributions in the ceramic samples were confirmed. The adsorptive and photocatalytic properties of the BaTiO3 (reference sample, BTO) and BaTiO3_MnO2 materials (BTO_x, where x is wt.% of MnO2 and x = 1, 2 or 3, denoted as BTO_1, BTO_2 and BTO_3, respectively) were evaluated using Rhodamine B (RhB) as the model dye in a photocatalytic chamber equipped with a UV lamp (15 W) in the absence of additional oxidants and (co)catalysts. No adsorption of RhB dye was found for all the materials during 360 min (dark experiment). All samples were photocatalytically active, and the best results were observed for the BTO_3 material, where RhB was 70% removed from aqueous solution during 360 min of irradiation. The photodegradation of RhB in the presence of MnO2-modified BTO ceramics followed a pseudo-first order model and the rate constant of BTO_3 was about 10 times higher than that of BTO, 2 times that of BTO_2, and 1.5 times that of BTO_1. The photocatalysts could be successfully reused after thermal activation.

Nanocomposites Prepared from Carbon Nanotubes and the Transition Metal Dichalcogenides WS2 and MoS2 via Surfactant-Assisted Dispersions as Electrocatalysts for Oxygen Reactions.

Fuel cells are emerging devices as clean and renewable energy sources, provided their efficiency is increased. In this work, we prepared nanocomposites based on multiwalled carbon nanotubes (MWNTs) and transition metal dichalcogenides (TMDs), namely WS2 and MoS2, and evaluated their performance as electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR), relevant to fuel cells. The one- and two-dimensional (1D and 2D) building blocks were initially exfoliated and non-covalently functionalized by surfactants of opposite charge in aqueous media (tetradecyltrimethylammonium bromide, TTAB, for the nanotubes and sodium cholate, SC, for the dichalcogenides), and thereafter, the three-dimensional (3D) MoS2@MWNT and WS2@MWNT composites were assembled via surfactant-mediated electrostatic interactions. The nanocomposites were characterized by scanning electron microscopy (SEM) and structural differences were found. WS2@MWNT and MoS2@MWNT show moderate ORR performance with potential onsets of 0.71 and 0.73 V vs. RHE respectively, and diffusion-limiting current densities of -1.87 and -2.74 mA·cm-2, respectively. Both materials present, however, better tolerance to methanol crossover when compared to Pt/C and good stability. Regarding OER performance, MoS2@MWNT exhibits promising results, with η10 and jmax of 0.55 V and 17.96 mA·cm-2, respectively. The fabrication method presented here is cost-effective, robust and versatile, opening the doors for the optimization of electrocatalysts' performance.

Venous Thrombosis and Thrombocyte Activity in Zebrafish Models of Quantitative and Qualitative Fibrinogen Disorders.

Venous thrombosis occurs in patients with quantitative and qualitative fibrinogen disorders. Injury-induced thrombosis in zebrafish larvae has been used to model human coagulopathies. We aimed to determine whether zebrafish models of afibrinogenemia and dysfibrinogenemia have different thrombotic phenotypes. Laser injuries were used to induce venous thrombosis and the time-to-occlusion (TTO) and the binding and aggregation of fluorescent Tg(itga2b:EGFP) thrombocytes measured. The fga-/- larvae failed to support occlusive venous thrombosis and showed reduced thrombocyte binding and aggregation at injury sites. The fga+/- larvae were largely unaffected. When genome editing zebrafish to produce fibrinogen Aα R28C, equivalent to the human Aα R35C dysfibrinogenemia mutation, we detected in-frame skipping of exon 2 in the fga mRNA, thereby encoding AαΔ19-56. This mutation is similar to Fibrinogen Montpellier II which causes hypodysfibrinogenemia. Aα+/Δ19-56 fish had prolonged TTO and reduced thrombocyte activity, a dominant effect of the mutation. Finally, we used transgenic expression of fga R28C cDNA in fga knock-down or fga-/- mutants to model thrombosis in dysfibrinogenemia. Aα R28C expression had similar effects on TTO and thrombocyte activity as Aα+/Δ19-56. We conclude that thrombosis assays in larval zebrafish can distinguish between quantitative and qualitative fibrinogen disorder models and may assist in anticipating a thrombotic phenotype of novel fibrinogen mutations.

Associations between binge eating, depressive symptoms and anxiety and weight regain after Roux-en-Y gastric bypass surgery.

BACKGROUND: Weight regain (WR) after bariatric surgery (BS) is frequent. OBJECTIVE: The aim of this study was to evaluate whether the occurrence of psychiatric disorders would be associated with short- and long-term WR after BS. METHODS: Ninety-six patients (77.6% female, age 40.2 ± 10.1 years, BMI of 50 ± 8.2 kg/m2) from the Obesity and Bariatric Surgery Outpatient Clinic of the Universidade Federal São Paulo completed the Questionnaire on Eating and Weight Patterns-Revised, the Beck Depression Inventory and an anxiety inventory to assess the occurrence of binge eating, depressive symptoms (DS) and anxious symptoms (AS) before and after short-term and long-term BS. RESULTS: Twenty-four months after BS, the prevalence of binge eating, depression and anxiety decreased from 100 to 13%, 100 to 15% and 43 to 4%, respectively. The mean WR of 35.2 ± 17.3% of weight loss occurred in nine patients after 24 months and was associated with binge eating (p = 0.002) but not with DS or AS. At long-term follow-up (12 ± 1.5 years), 67% had a mean WR of 50.3 ± 24.9%. The prevalence of binge eating, DS and AS were 48%, 46% and 63%, respectively, in this group, and significant associations were observed between WR and binge eating (p = 0.001), DS (p = 0.029) and AS (p = 0.001). Furthermore, the number of psychiatric disorders was inversely associated with the percentage of weight loss (p < 0.05) and positively associated with WR (p < 0.05). CONCLUSION: Weight regain was associated with the occurrence of binge eating in the short and long term after BS, whereas the occurrence of depressive and anxious symptoms was associated with WR only in the long term. LEVEL III: Evidence obtained from well-designed cohort or case-control analytic studies.

Optimizing the extraction of phenolic antioxidants from chestnut shells by subcritical water extraction using response surface methodology.

The objective of this study was to evaluate the optimal Subcritical Water Extraction (SWE) conditions of antioxidants and polyphenols from chestnut shells using Response Surface Methodology (RSM). A central composite design (CCD) was conducted to analyse the time (6-30 min) and temperature (51-249 °C) effects in antioxidant activity (ABTS, DPPH and FRAP) and Total Phenolic Compounds (TPC). TPC ranged from 315.21 to 496.80 mg gallic acid equivalents (GAE)/g DW; the DPPH from 549.23 to 1125.68 mg Trolox equivalents (TE)/g DW; ABTS varied between 631.16 and 965.45 mg ascorbic acid equivalents (AAE)/g DW and FRAP from 2793.95 to 11393.97 mg ferrous sulphate equivalents (FSE)/g DW. The optimal extraction conditions were 30 min/220 °C, revealing excelling scavenging efficiencies against HOCl (IC50 = 0.79 µg/mL) and O2- (IC50 = 12.92 µg/mL) without toxicity on intestinal cells (0.1 µg/mL). The phenolic composition revealed high amounts of pyrogallol and protocatechuic acid. SWE can be a useful extraction technique for the recovery of polyphenolics from chestnut shells.

A genetic modifier of venous thrombosis in zebrafish reveals a functional role for fibrinogen AαE in early hemostasis.

Plasma fibrinogen molecules comprise 2 copies of Aα, Bß, and γ chains folded into a hexameric protein. A minor fibrinogen isoform with an extended Aα chain (AαE) is more abundant in newborn human blood than in adults. Larval zebrafish produce predominantly AαE-containing fibrinogen, but its functional significance is unclear. In 3-day-old zebrafish, when hemostasis is reliant on fibrinogen and erythrocyte-rich clotting but is largely thrombocyte-independent, we measured the time to occlusion (TTO) in a laser-induced venous thrombosis assay in 3 zebrafish strains (AB, TU, and AB × TL hybrids). AB larvae showed delayed TTO compared with the TU and AB × TL strains. Mating AB with TU or TL produced larvae with a TU-like TTO. In contrast to TU, AB larvae failed to produce fibrinogen AαE, due to a mutation in the AαE-specific coding region of fibrinogen α-chain gene (fga). We investigated whether the lack of AαE explained the delayed AB TTO. Transgenic expression of AαE, but not Aα, shortened the AB TTO to that of TU. AαE rescued venous occlusion in fibrinogen mutants or larvae with morpholino-targeted fibrinogen α-chain messenger RNA, but Aα was less effective. In 5-day-old larvae, circulating thrombocytes contribute to hemostasis, as visualized in Tg(itga2b:EGFP) transgenics. Laser-induced venous thrombocyte adhesion and aggregation is reduced in fibrinogen mutants, but transgenic expression of Aα or AαE restored similar thrombocyte accumulation at the injury site. Our data demonstrate a genetic modifier of venous thrombosis and a role for fibrinogen AαE in early developmental blood coagulation, and suggest a link between differentially expressed fibrinogen isoforms and the cell types available for clotting.

Progestogens Are Metabolized by the Gut Microbiota: Implications for Colonic Drug Delivery.

Following oral administration, the bioavailability of progestogens is very low and highly variable, in part due to metabolism by cytochrome P450 enzymes found in the mucosa of the small intestine. Conversely, the mucosa in the colon contains much lower levels of cytochrome P450 enzymes, thus, colonic delivery of progestogens may be beneficial. Microbiota in the colon are known to metabolize a great number of drugs, therefore, it is important to understand the stability of these hormones in the presence of colonic flora before developing formulations. The aim of this study was to investigate the stability of three progestogens: progesterone, and its two synthetic analogues, medroxyprogesterone acetate (MPA) and levonorgestrel (LNG), in the presence of human colonic microbiota. Progesterone, MPA, and LNG were incubated in mixed fecal inoculum (simulated human colonic fluid) under anerobic conditions. Progesterone was completely degraded after 2 h, whereas levels of MPA and LNG were still detectable after 24 h. The half-lives of progesterone, MPA, and LNG in fecal inoculum were 28, 644, and 240 min, respectively. This study describes the kinetics of colonic microbial metabolism of these hormones for the first time. MPA and LNG show promise for delivery to the colon, potentially improving pharmacokinetics over current oral delivery methods.

Evaluation of the Extraction Temperature Influence on Polyphenolic Profiles of Vine-Canes (Vitis vinifera) Subcritical Water Extracts.

This work focused on evaluating the possibility of using vineyard pruning wastes from two Portuguese Vitis vinifera varieties; Touriga Nacional (TN) and Tinta Roriz (TR), as new potential ingredients for the nutraceutical industry. An environmentally friendly extraction technique; namely subcritical-water extraction (SWE), was employed. The overall results indicate that phenolic acids were the major class of compounds quantified; being gallic acid the principal one. The highest value for total phenolic content (TPC) was obtained for the TR extract at 250 °C (181 ± 12 mg GAE/g dw). In terms of antioxidant activity; the DPPH values for the extracts obtained at 250 °C were approximately 4-fold higher than the ones obtained at 125 °C; with TR extract presenting the highest value (203 ± 22 mg TE/g dw). Thus, the TR extract obtained through SWE at 250 °C was selected to evaluate the scavenging activity and the in vitro effects on cells due to the best results achieved in the previous assays. This extract presented the ability to scavenge reactive oxygen species (O2●-, HOCl and ROO●). No adverse effects were observed in HFF-1 viability after exposure to extract concentrations below 100 µg/mL. This work demonstrated that vine-canes extracts could be a potential ingredient to nutraceutical industry.

Ru single atoms and nanoparticles on carbon nanotubes as multifunctional catalysts.

In the last decade we have witnessed increasing interest in the production of renewable energy and value-added chemicals through sustainable and low-cost technologies where catalysts play a crucial role. Herein, we report the application of a Ru/CNT material containing a mixture of Ru single atoms and Ru nanoparticles as a multifunctional catalyst for both the catalytic reduction of nitroarenes and the electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The catalytic activity of the Ru-CNT material was evaluated in the reduction of 4-nitrophenol (4-NP), 4-nitroaniline (4-NA) and 2-nitrophenol (2-NP) in the presence of sodium borohydride as a reducing agent at room temperature, showing high catalytic activity with normalized rate constants (knor) of 19.0 × 103, 57.7 × 103 and 16.6 × 103 min-1 mmol-1 respectively. Furthermore, the catalyst could be reused in at least 10 cycles without catalytic activity loss, confirming the high stability and robustness of the material. The Ru/CNT material also showed good ORR electrocatalytic activity in alkaline medium with Eonset of 0.76 V vs. RHE, a diffusion-limited current density of 3.89 mA cm-2 and ñO2 of 3.3. In addition, Ru/CNT was remarkably insensitive to methanol with a current retention of 93% (51% for Pt/C) and competitive electrochemical stability of 80% after 20 000 s. Moreover, Ru/CNT was active for the OER with jmax = 29.5 mA cm-2 at E = 1.86 V vs. RHE, η10 = 0.50 V and good stability (η10 changed to 0.01 V and jmax only decreased by ≈12% after 500 cycles).

Electrochemical immunosensor towards invasion-associated protein p60: An alternative strategy for Listeria monocytogenes screening in food.

This work reports the development of an electrochemical immunosensor for rapid, specific and decentralized detection of the invasion-associated protein p60 secreted by Listeria monocytogenes, a life-threatening foodborne pathogen. A disposable screen-printed electrode was used as transducer surface and monoclonal and polyclonal antibodies that specifically recognize Listeria monocytogenes p60 protein and Listeria spp. p60 proteins, respectively, were used as the sandwich immuno-pair. The reaction was detected with the aid of an additional secondary antibody conjugated with the enzyme reporter (alkaline phosphatase) and using 3-indoxyl phosphate/silver ions as the mixture substrate. The analytical signal was acquired through the voltammetric stripping of the enzymatically deposited silver, which was directly correlated to p60 concentration in the sample. In optimized conditions, a limit of detection and quantification of 1.5 ng mL-1 and 5.1 ng mL-1 were achieved, respectively, in a useful time (<3 h). As proof-of-concept, the proposed immunosensor was successfully applied to spiked milk samples, demonstrating to be a suitable device for further use in real sample detection of Listeria monocytogenes in food products.

Vine-Canes Valorisation: Ultrasound-Assisted Extraction from Lab to Pilot Scale.

Wine production generates large amounts of vine-canes, a devalued by-product that could be used for the recovery of bioactive compounds. In this work, two vine-canes varieties, namely Touriga Nacional (TN) and Tinta Roriz (TR), were submitted to different ultrasound-assisted extraction (UAE) conditions. The highest phenolic and flavonoid content was observed for TR extract obtained at lab-scale without an ice bath and pilot-scale after 60 min of extraction (32.6 ± 2.1 and 26.0 ± 1.5 mg gallic acid equivalent/g dry weight (dw) and 9.5 ± 0.6 and 8.3 ± 0.8 mg epicatechin equivalents/g dw, respectively). Further, all extracts demonstrated a high antioxidant activity to scavenge DPPH free radicals with the best value reached by TR at the lab-scale without an ice bath after 30 min and pilot-scale extraction after 60 min (34.2 ± 2.4 and 33.4 ± 2.1 mg trolox equivalents/g dw, respectively). Extracts phenolic composition were also evaluated by HPLC, demonstrating that resveratrol, myricetin and catechin were the main compounds. According to our knowledge, this is the first time that a pilot scale of UAE of phenolic compounds from vine-canes was performed. This paper represents an important step to the use of UAE as an industrial process to recover bioactive compounds.