Trivalent Copper Ion-Mediated Dual Oxidation in the Copper-Catalyzed Fenton-Like System in the Presence of Histidine.

The Cu(II)/H2O2 system is recognized for its potential to degrade recalcitrant organic contaminants and inactivate microorganisms in wastewater. We investigated its unique dual oxidation strategy involving the selective oxidation of copper-complexing ligands and enhanced oxidation of nonchelated organic compounds. L-Histidine (His) and benzoic acid (BA) served as model compounds for basic biomolecular ligands and recalcitrant organic contaminants, respectively. In the presence of both His and BA, the Cu(II)/H2O2 system rapidly degraded His complexed with copper ions within 30 s; however, BA degraded gradually with a 2.3-fold efficiency compared with that in the absence of His. The primary oxidant responsible was the trivalent copper ion [Cu(III)], not hydroxyl radical (•OH), as evidenced by •OH scavenging, hydroxylated BA isomer comparison with UV/H2O2 (a •OH generating system), electron paramagnetic resonance, and colorimetric Cu(III) detection via periodate complexation. Cu(III) selectively oxidized His owing to its strong chelation with copper ions, even in the presence of excess tert-butyl alcohol. This selectivity extended to other copper-complexing ligands, including L-asparagine and L-aspartic acid. The presence of His facilitated H2O2-mediated Cu(II) reduction and increased Cu(III) production, thereby enhancing the degradation of BA and pharmaceuticals. Thus, the Cu(II)/H2O2 system is a promising option for dual-target oxidation in diverse applications.

Effect of protein fouling on filtrate flux and virus breakthrough behaviors during virus filtration process.

Virus filtration process is used to ensure viral safety in the biopharmaceutical downstream processes with high virus removal capacity (i.e., >4 log10 ). However, it is still constrained by protein fouling, which results in reduced filtration capacity and possible virus breakthrough. This study investigated the effects of protein fouling on filtrate flux and virus breakthrough using commercial membranes that had different symmetricity, nominal pore size, and pore size gradients. Flux decay tendency due to protein fouling was influenced by hydrodynamic drag force and protein concentration. As the results of prediction with the classical fouling model, standard blocking was suitable for most virus filters. Undesired virus breakthrough was observed in the membranes having relatively a large pore diameter of the retentive region. The study found that elevated levels of protein solution reduced virus removal performance. However, the impact of prefouled membranes was minimal. These findings shed light on the factors that influence protein fouling during the virus filtration process of biopharmaceutical production.

Practical scale evaluation of a photocatalytic air purifier equipped with a Titania-zeolite composite bead filter for VOC removal and viral inactivation.

A practical scale photocatalytic air purifier equipped with a TiO2/H-ZSM-5 composite bead filter was demonstrated to be able to effectively remove indoor volatile organic compounds (VOCs) and viruses with sustainable performances under UVA-LED illumination. TiO2 hybridized with 5 wt% H-ZSM-5 zeolite significantly enhanced its photocatalytic activity for degrading VOCs including formaldehyde, acetaldehyde, and toluene, than bare TiO2. H-ZSM-5 provided strong adsorption sites for these compounds, thus accelerating their photocatalytic conversion into CO2 by adjacent TiO2 photocatalyst. Moreover, owing to its superior adsorption capacity, the composite bead filter completely prevented the emission of formaldehyde produced by photocatalytic oxidation of toluene. The sustainability of this composite bead filter for VOC removal was confirmed by regeneration and accelerated durability tests. In addition, the photocatalytic air purifier was effective in removing aerosolized viral particles of bacteriophage Phi-X 174. It was confirmed that the viruses on filter surfaces were completely inactivated by photocatalytic oxidation. TiO2/H-ZSM-5 composite beads also exhibited excellent efficacies for inactivation of pathogenic coronaviruses including SARS-CoV-2. The photocatalytic process degraded viral RNAs of SARS-CoV-2 by more than 99.999% in 1 h, eliminating the viral infectivity. Results of this study suggest that the air purifier equipped with the composite bead filter is ready for practical applications for home and hospital uses.

Long-Term Outcomes of Surgical Repair for Ventricular Septal Defect in Adults.

Data of the outcomes of ventricular septal defect (VSD) closure in adults are limited to establish recommendations. Therefore, we reviewed our experience with surgical VSD closure in adult patients. We retrospectively reviewed 152 patients who underwent surgical VSD closure between January 1996 and April 2020. The median age of the patients was 30.5 [interquartile range (IQR) 23.1-42.7] years. The median follow-up duration was 10.9 (IQR 4.8-16.1) years. VSDs were classified according to the Society of Thoracic Surgeons classification as type 2 (n = 66, 43.4%), type 1 (n = 59, 38.8%), and type 4 (n = 27, 17.8%). Aortic cusp prolapse (n = 86, 56.6%) and aortic valve regurgitation (AR, n = 75, 49.3%) were the most common indications for surgical closure. Four patients underwent late reoperation (2.6%) due to AR, infective endocarditis and residual VSD. In the log-rank test, preoperative trivial or more degree of AR (P = 0.004) and coronary cusp deformity (P = 0.031) was associated with late moderate or greater degree of AR. Preoperative moderate or greater AR was associated with reoperation (P = 0.047). Only concomitant aortic valve (AV) repair at the time of VSD closure was a significant risk factor for late significant AR progression in the multivariable analysis. VSD closure in adults can be performed with low mortality and morbidity rates. AR can progress after VSD closure because the aortic cusp may have irreversible damage from long-standing shunt flow exposure. We conclude that VSD with AV deformity or AR in adults should be treated aggressively before disease progression with irreversible damage occurs.

Tricuspid Valve Repair at Pulmonary Valve Replacement in Repaired Tetralogy of Fallot.

BACKGROUND: Pulmonary valve replacement (PVR) is often performed in patients with repaired tetralogy of Fallot (TOF). Concomitant tricuspid valvuloplasty (TVP) in those with tricuspid regurgitation (TR) at the time of PVR is still controversial. METHOD: We retrospectively reviewed clinical records of patients who underwent PVR between 2001 and 2012. We analyzed the impact of concomitant TVP on the tricuspid valve function and right ventricle function and size in mid-term. RESULTS: 119 patients with mild to moderate TR at the time of PVR were enrolled. 33 patients underwent concomitant TVP (TVP group) and 86 patients underwent PVR alone (no-TVP group). There was a significant reduction of TR (p < 0.001) and right ventricular end-diastolic volume index (RVEDVi) (p < 0.001). However, in patients who showed prosthetic pulmonary valve (PV) failure at the last follow-up, there was no significant decrease in TR regardless of concomitant TVP. In the patients with preserved prosthetic PV function, TR was significantly improved (p < 0.001 in both groups). The multivariable analysis showed that significant risk factors for recurrence of significant TR were preoperative moderate TR and prosthetic PV failure. CONCLUSIONS: After PVR in repaired TOF patients, there was an improvement in the degree of TR and the RVEDVi. Concomitant TVP at the time of PVR may not be able to prevent the recurrence of TR when prosthetic PV failure occurs; however, it may effectively preserve tricuspid valve function until that time.

Fabrication of Ag-doped ZnO/PAN composite nanofibers by electrospinning: Photocatalytic and antiviral activities.

Ag-doped ZnO nanoparticles (AZNs) were directly synthesized using sol-gel method to embed into polyacrylonitrile (PAN) nanofibers by electrospinning. The synthesized AZNs were optically and structurally characterized by UV-VIS spectroscopy, photoluminescence spectroscopy, high resolution HR-TEM and XRD. The photocatalytic activity of the AZNs was examined by photocatalytic degradation of methylene blue to correlate with their antiviral efficacy in PAN nanofibers fabricated via electrospinning technique. The PAN nanofibers containing AZNs were characterized using SEM and EDS. Finally, antiviral activity of AZNs/PAN nanofibers was investigated by using virus ϕx174 under visible light irradiation. As a result, the antiviral efficacy of nanofibers increased as the concentration of Ag in AZNs increased. The results show that better antiviral efficacy was obtained in AZNs/PAN nanofibers prepared with AZNs of higher photocatalytic performance.

Prediction of Oxidant Exposures and Micropollutant Abatement during Ozonation Using a Machine Learning Method.

Oxidation of micropollutants (MPs) by ozonation proceeds via the reactions with molecular ozone (O3) and hydroxyl radicals (•OH). To predict MP abatement during ozonation, a model that can accurately predict oxidant exposures (i.e., ∫0t[O3]dt⁢ and⁢ ∫0t[O•H]dt) needs to be developed. This study demonstrates machine learning models based on the random forest (RF) algorithm to output oxidant exposures from water quality parameters (input variables) that include pH, alkalinity, dissolved organic carbon concentration, and fluorescence excitation-emission matrix (FEEM) data (to characterize organic matter). To develop the models, 60 different samples of natural waters and wastewater effluents were collected and characterized, and the oxidant exposures in each sample were determined at a specific O3 dose (2.5 mg/L). Four RF models were developed depending on how FEEM data were utilized (i.e., one model free of FEEM data, and three other models that used FEEM data of different resolutions). The regression performance and Akaike information criterion (AIC) were evaluated for each model. The models using high-resolution FEEM data generally exhibited high prediction accuracy with reasonable AIC values, implying that organic matter characteristics quantified by FEEM can be important factors to improve the accuracy of the prediction model. The developed models can be applied to predict the abatement of MPs in drinking water and wastewater ozonation processes and to optimize the O3 dose for the intended removal of target MPs. The machine learning models using higher-resolution FEEM data offer more accurate prediction by better calculating the complex nonlinear relationship between organic characteristics and oxidant exposures.

Chloride-Mediated Enhancement in Heat-Induced Activation of Peroxymonosulfate: New Reaction Pathways for Oxidizing Radical Production.

This study is the first to demonstrate the capability of Cl- to markedly accelerate organic oxidation using thermally activated peroxymonosulfate (PMS) under acidic conditions. The treatment efficiency gain allowed heat-activated PMS to surpass heat-activated peroxydisulfate (PDS). During thermal PMS activation at excess Cl-, accelerated oxidation of 4-chlorophenol (susceptible to oxidation by hypochlorous acid (HOCl)) was observed along with significant degradation of benzoic acid and ClO3- occurrence, which involved oxidants with low substrate specificity. This indicated that heat facilitated HOCl formation via nucleophilic Cl- addition to PMS and enabled free chlorine conversion into less selective oxidizing radicals. HOCl acted as a key intermediate in the major oxidant transition based on temperature-dependent variation in HOCl concentration profiles, kinetically retarded organic oxidation upon NH4+ addition, and enabled rapid organic oxidation in heated PMS/HOCl mixtures. Chlorine atom that formed via the one-electron oxidation of Cl- by the sulfate radical served as the primary oxidant and was involved in hydroxyl radical production. This was corroborated by the quenching effects of alcohols and bicarbonates, reactivity toward multiple organics, and electron paramagnetic resonance spectral features. PMS outperformed PDS in degrading benzoic acid during thermal activation operated in reverse osmosis concentrate, which was in conflict with the well-established superiority of heat-activated PDS.

Long-term and stable antimicrobial properties of immobilized Ni/TiO2 nanocomposites against Escherichia coli, Legionella thermalis, and MS2 bacteriophage.

Nickel has been extensively used as a high work function metal because of its abundance, low cost, relatively non-toxic nature, and environmentally benign characteristics. However, it has rarely been extended in a form of immobilized composite, which is a practical strategy applicable for photocatalytic antimicrobial activities. In this study, a composite of nickel and TiO2 (Ni/TiO2) was prepared using a photodeposition method, and its antibacterial properties were investigated using Escherichia coli (E. coli). To optimize Ni/TiO2 synthesis, the effect of various photodeposition conditions on antibacterial performance were investigated, such as the light irradiation time, metal content, TiO2 crystalline structure, and presence or absence of electron donors (i.e., methanol). The optimized 2 wt% Ni/TiO2 exhibited an antibacterial efficiency of 3.74 log within 7 min, which is more than 10-fold higher than that of pristine TiO2 (2.54 log). Based on this optimized weight ratio, Ni/TiO2 was immobilized on a steel mesh using an electrospray/thermal compression method, and its antibacterial performance was further assessed against E. coli, MS2 bacteriophage virus (MS2 phage), and a common pulmonary pathogen (Legionella thermalis, L. thermalis). Within 70 min, all target microorganisms achieved an inactivation that exceeded 4 log. Furthermore, the long-term stability and sustainable usability of the Ni/TiO2 mesh were confirmed by performing more than 50 antibacterial evaluation cycles using E. coli. The results of this study facilitate the successful utilization of immobilized Ni/TiO2 mesh in water disinfection applications.

Versatile Yolk-Shell Encapsulation: Catalytic, Photothermal, and Sensing Demonstration.

Here, a novel, versatile synthetic strategy to fabricate a yolk-shell structured material that can encapsulate virtually any functional noble metal or metal oxide nanocatalysts of any morphology in a free suspension fashion is reported. This strategy also enables encapsulation of more than one type of nanoparticle inside a single shell, including paramagnetic iron oxide used for magnetic separation. The mesoporous organosilica shell provides efficient mass transfer of small target molecules, while serving as a size exclusion barrier for larger interfering molecules. Major structural and functional advantages of this material design are demonstrated by performing three proof-of-concept applications. First, effective encapsulation of plasmonic gold nanospheres for localized photothermal heating and heat-driven reaction inside the shell is shown. Second, hydrogenation catalysis is demonstrated under spatial confinement driven by palladium nanocubes. Finally, the surface-enhanced Raman spectroscopic detection of model pollutant by gold nanorods is presented for highly sensitive environmental sensing with size exclusion.

Activation of Hydrogen Peroxide by a Titanium Oxide-Supported Iron Catalyst: Evidence for Surface Fe(IV) and Its Selectivity.

Iron immobilized on supports such as silica, alumina, titanium oxide, and zeolite can activate hydrogen peroxide (H2O2) into strong oxidants. However, the role of the support and the nature of the oxidants produced in this process remain elusive. This study investigated the activation of H2O2 by a TiO2-supported catalyst (FeTi-ox). Characterizing the catalyst surface in situ using X-ray absorption spectroscopy (XAS), together with X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR), revealed that the interaction between H2O2 and the TiO2 phase played a key role in the H2O2 activation. This interaction generated a stable peroxo-titania ≡Fe(III)-Ti-OOH complex, which reacted further with H2O to produce a surface oxidant, likely ≡Fe[IV] ═ O2+. The oxidant effectively degraded acetaminophen, even in the presence of chloride, bicarbonate, and organic matter. Unexpectedly, contaminant oxidation continued after the H2O2 in the solution was depleted, owing to the decomposition of ≡Fe(III)-Ti-OOH by water. In addition, the FeTi-ox catalyst effectively degraded acetaminophen over five testing cycles. Overall, new insights gained in this study may provide a basis for designing more effective catalysts for H2O2 activation.

Correlation Between Total Repair Timing and Late Aortic Root Dilatation in Repaired Tetralogy of Fallot.

Aortic root dilatation is frequently encountered in adults with repaired Tetralogy of Fallot (TOF). The timing of total repair is known to have a significant correlation with late aortic root dilatation, but it is not well established. The objective of this study was to investigate the risk factors and correlation with timing of total repair for aortic root dilatation in adults with repaired TOF. An observational retrospective cohort study was conducted in 314 adults (≥ 18 years) with repaired TOF. Aortic root dilatation was defined when the absolute diameter of Sinus of Valsalva (SoV) was over 40 mm. SoV was measured by echocardiography in 110 patients, computed tomography angiography in 168 patients, and magnetic resonance image in 36 patients. Aortic root dilatation was observed in 65 patients (20.7%). Among them, 3 patients underwent Bentall operation due to acute aortic dissection or aortic root aneurysm. On multivariate logistic regression analysis, age at total repair was a significant risk factor for late aortic root dilatation (OR = 3.14; 95% CI 1.62-6.08; p = 0.001) and the cutoff value of age was 1.9 years. However, late aortic root dilatation was also observed in 10% of patients (10/91) who operated before 1 year of age. Late total repair was a significant risk factor for late aortic root dilatation in repaired TOF. However, early total repair did not always prevent late aortic root dilatation. These results suggest that congenital aortic pathology may also be a possible cause of aortic root dilatation along with longstanding hemodynamic stress.

Ozonation of Microcystins: Kinetics and Toxicity Decrease.

The ozonation of six microcystins (MCs) (MC-LR, MC-RR, MC-LA, MC-LF, MC-YR, and MC-LW) was investigated with a focus on the kinetics and decrease in toxicity. Second-order rate constants for the reactions of the six MCs with O3 and •OH ( kO3,MC and k•OH,MC) ranged from 7.1 × 105 to 6.1 × 106 M-1 s-1 ( kO3,MC) and from 1.2 × 1010 to 1.8 × 1010 M-1 s-1 ( k•OH,MC), at pH 7.2 and 20 °C. The activation energies were calculated to be 21.6-34.5 and 11.6-13.1 kJ mol-1 for kO3,MC and k•OH,MC, respectively. The rate constants did not show an important pH dependency, except for kO3,MC-YR, which increased at pH > 7. A kinetic model using the determined rate constants and the measured exposures of O3 and •OH was able to precisely predict the removal of MCs in natural water. The hepatotoxicities of MCs were decreased by ozonation; the toxicities of the four MCs (MC-LR, MC-RR, MC-LA, and MC-LF) decreased nearly concurrently with decreases in their concentrations. However, MC-YR and MC-LW showed a gap between the concentration and toxicity as a result of the incomplete destruction of the Adda moiety (a key amino acid expressing the hepatotoxicity of MCs). A product study using liquid chromatography-mass spectrometry identified a number of oxidation products with an intact Adda moiety produced by the ozonation of MC-YR and MC-LW.

Spontaneous Generation of H2O2 and Hydroxyl Radical through O2 Reduction on Copper Phosphide under Ambient Aqueous Condition.

Copper phosphide (Cu xP) was synthesized and tested for its reactivity for generating H2O2 through spontaneous reduction of dioxygen under ambient aqueous condition. The in situ generated H2O2 was subsequently decomposed to generate OH radicals, which enabled the degradation of organic compounds in water. The oxygen reduction reaction proceeded along with the concurrent oxidation of phosphide to phosphate, then copper ions and phosphate ions were dissolved out during the reaction. The reactivity of Cu xP was gradually reduced during 10 cycles with consuming 8.7 mg of Cu xP for the successive removal of 17 µmol 4-chlorophenol. CoP which was compared as a control sample under the same experimental condition also produced H2O2 through activating dioxygen but did not degrade organic compounds at all. The electrochemical analysis for the electron transfers on Cu xP and CoP showed that the number of electrons transferred to O2 is 3 and 2, respectively, which explains why OH radical is generated on Cu xP, not on CoP. The Cu+ species generated on the Cu xP surface can participate in Fenton-like reaction with in situ generated H2O2. Cu xP is proposed as a solid reagent that can activate dioxygen to generate reactive oxygen species in ambient aqueous condition, which is more facile to handle and store than liquid/gas reagents (e.g., H2O2, Cl2, O3).

Differential Microbicidal Effects of Bimetallic Iron-Copper Nanoparticles on Escherichia coli and MS2 Coliphage.

Bimetallic iron-copper nanoparticles (Fe/Cu-NPs) were synthesized by a single-pot surfactant-free method in aqueous solution [via the reduction of ferrous ion to zerovalent iron nanoparticles (Fe-NPs) and the subsequent copper-coating by metal ion exchange]. The produced Fe/Cu-NPs formed aggregates of spherical nanoparticles (approximately 30-70 nm) of Fe-Cu core-shell structures with 11 wt % copper content. The microbicidal effects of Fe/Cu-NPs were explored on Escherichia coli and MS2 coliphage, surrogates for bacterial and viral pathogens, respectively. Fe/Cu-NPs exhibited synergistically enhanced activity for the inactivation of E. coli and MS2, compared to single-metal nanoparticles (i.e., Fe-NPs and Cu-NPs). Various experiments (microbial inactivation tests under different conditions, fluorescence staining assays, experiments using ELISA and qRT-PCR, etc.) suggested that Fe/Cu-NPs inactivate E. coli and MS2 via dual microbicidal mechanisms. Two biocidal copper species [Cu(I) and Cu(III)] can be generated by different redox reactions of Fe/Cu-NPs. It is suggested that E. coli is strongly influenced by the cytotoxicity of Cu(I), while MS2 is inactivated mainly due to the oxidative damages of protein capsid and RNA by Cu(III).

Assessing the recently noted surgical outcome of isolated total anomalous pulmonary venous connection repair: A single-secondary center experience.

BACKGROUND AND AIM OF THE STUDY: Total anomalous pulmonary venous connection (TAPVC) is a rare cyanotic congenital heart defect. This study aimed to evaluate the outcome of isolated TAPVC repairs and the prognoses of affected patients in the last 12 years at a single center. METHODS: We retrospectively analyzed the medical records of 51 patients who underwent isolated TAPVC repair from 2007 to 2018. RESULTS: The median age at operation was 19 days, and the median body weight was 3.3 kg. Thirteen (25.5%) patients had emergency operations, and the median follow-up period was 29.54 ± 36.77 months. Early mortality was noted in five patients and late mortality was noted in one patient. Pulmonary vein stenosis was observed in 22 patients within 3 to 6 months after the operation, and six patients required reoperation or transcatheter interventions. Low birth weight, small left atrial volume, long operation time, and preoperative heart failure were identified as risk factors for mortality. CONCLUSIONS: Isolated TAPVC can rapidly lead to hemodynamic instability during the neonatal period and is associated with high mortality rates. Increasing the prenatal diagnosis rate and stabilizing the patients' condition before the operation are considered important for improving the surgical outcome.

Relation Between Exercise Capacity and Extracardiac Conduit Size in Patients with Fontan Circulation.

Because Fontan circulation does not have a subpulmonary ventricle, the preload is limited. In Fontan circulation with extracardiac conduit, the size of conduit could be an important factor in determining the preload. We compared exercise capacity with each conduit size and tried to search for optimal conduit size in Fontan circulation. We reviewed the medical record of 677 patients with Fontan circulation. Patients who had other type Fontan circulation (Kawashima, atriopulmonary, lateral tunnel), SpO2 < 85%, protein losing enteropathy, results of inappropriate exercise test were excluded. As a result, 150 patients were enrolled and classified according to conduit size. We compared with their exercise capacity and analyzed correlation between exercise capacity and conduit size per body surface area (BSA). 97 Males were included and mean age was 17.5 ± 5.1 years old. In cardiac catheterization, central venous pressure (CVP) was 12.4 ± 2.5 mmHg and pulmonary vascular resistance was 1.2 ± 0.5 wu m2. In cardiopulmonary exercise test, predictive peak VO2 was 59.1 ± 9.7% and VE/VCO2 was 36.2 ± 6.9. In analysis using quadratic model, impacts of gender, age at Fontan operation, ventricular morphology, isomerism, and fenestration on exercise capacity were excluded and conduit size per BSA had a significant curved correlation with predictive peak VO2 and VE/VCO2. Our results showed that patients with about 12.5 mm/m2 conduit per BSA have the best exercise capacity. Patients with larger than smaller-sized conduit were found to be more attenuated in their ability to exercise.

Oxidation of Microcystins by Permanganate: pH and Temperature-Dependent Kinetics, Effect of DOM Characteristics, and Oxidation Mechanism Revisited.

Oxidative degradation of six representative microcystins (MCs) (MC-RR, -LR, -YR, -LF, -LW, and -LA) by potassium permanganate (KMnO4; Mn(VII)) was investigated, focusing on the temperature- and pH-dependent reaction kinetics, the effect of dissolved organic matter (DOM), and the oxidation mechanisms. Second-order rate constants for the reactions of the six MCs with Mn(VII) ( kMn(VII),MC) were determined to be 160.4-520.1 M-1 s-1 (MC-RR > -LR ≈ -YR > -LF ≈ -LW > -LA) at pH 7.2 and 21 °C. The kMn(VII),MC values exhibited activation energies ranging from 15.1 to 22.4 kJ mol-1. With increasing pH from 2 to 11, the kMn(VII),MC values decreased until pH 5, and plateaued over the pH range of 5-11, except for that of MC-YR (which increased at pH > 8). Species-specific second-order rate constants were calculated using predicted p Ka values of MCs. The oxidation of MCs in natural waters was accurately predicted by the kinetic model using kMn(VII),MC and Mn(VII) exposure (∫[Mn(VII)]dt) values. Among different characteristics of DOM in natural waters, UV254, SUVA254, and the abundance of humic-like substances characterized by fluorescence spectroscopy exhibited good correlation with ∫[Mn(VII)]dt. A thorough product study of MC-LR oxidation by Mn(VII) was performed using liquid chromatography-mass spectrometry.

Activation of Periodate by Freezing for the Degradation of Aqueous Organic Pollutants.

A new strategy (i.e., freezing) for the activation of IO4- for the degradation of aqueous organic pollutants was developed and investigated. Although the degradation of furfuryl alcohol (FFA) by IO4- was negligible in water at 25 °C, it proceeded rapidly during freezing at -20 °C. The rapid degradation of FFA during freezing should be ascribed to the freeze concentration effect that provides a favorable site (i.e., liquid brine) for the proton-coupled degradation process by concentrating IO4-, FFA, and protons. The maximum absorption wavelength of cresol red (CR) was changed from 434 nm (monoprotonated CR) to 518 nm (diprotonated CR) after freezing, which confirms that the pH of the aqueous IO4- solution decreases by freezing. The degradation experiments with varying experimental parameters demonstrate that the degradation rate increases with increasing IO4- concentration and decreasing pH and freezing temperature. The application of the IO4-/freezing system is not restricted to FFA. The degradation of four other organic pollutants (i.e., tryptophan, phenol, 4-chlorophenol, and bisphenol A) by IO4-, which was negligible in water, proceeded during freezing. In addition, freezing significantly enhanced the IO4--mediated degradation of cimetidine. The outdoor experiments performed on a cold winter night show that the IO4-/freezing system for water treatment can be operated without external electrical energy.

Hepatic Stiffness Using Shear Wave Elastography and the Related Factors for a Fontan Circulation.

Hepatic problems related to a Fontan circulation have been highlighted and elastography using ultrasound is a non-invasive tool that can measure the severity of hepatic stiffness. We investigated the hepatic stiffness using shear wave elastography (SWE) and related factors in patients with a Fontan circulation. This study enrolled 64 patients with a Fontan circulation who underwent cardiac catheterization and abdominal ultrasound from 2011 to 2015. The correlation between the laboratory tests, hemodynamic factors by cardiac catheterization, and SWE was evaluated. The patients were classified into non-cirrhotic level (≥ 2.0 m/s) and cirrhotic level (< 2.0 m/s) groups by the SWE value. The mean age was 17.6 years and the mean duration after the Fontan operation was 12.1 years. The mean value of SWE in patients (1.95 m/s) was higher than the normal (< 1.3 m/s). The SWE was higher in patients without than those with a fenestration (2.03 vs. 1.75 m/s, P = 0.003). In a multiple regression analysis between SWE and other factors, the CVP, fenestration, and lipoprotein Apo B had a significant correlation. In a multivariate analysis of cirrhotic level group, the CVP was the only significant factor. The hepatic stiffness had significantly progressed in most patients with a Fontan circulation. A low CVP and Fontan circulation with a fenestration might reduce the progression of the hepatic stiffness.