Development of ionic-liquid-impregnated activated carbon for sorptive removal of PFAS in drinking water treatment.

Adsorption of per- and poly-fluoroalkyl substances (PFAS) on activated carbon (AC) is considerably hindered by the surface water constituents, degrading the ability of the AC adsorption process to remove PFAS in drinking water treatment. Herein, we developed ionic-liquid-impregnated AC (IL/AC) as an alternative to AC for PFAS sorption and demonstrated its performance with real surface water for the first time. Ionic liquids (ILs) of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (IL(C2)) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (IL(C6)) were selected from among 272 different ILs using the conductor-like screening model for realistic solvents (COSMO-RS) simulation. Impregnation of the ILs in AC was verified using various analytical techniques. Although the synthesized IL/ACs were less effective than pristine AC in treating PFAS in deionized water, their performances were less impacted by the surface water constituents, resulting in comparable or sometimes better performances than pristine AC for treating PFAS in surface water. The removal efficiencies of 10 wt% IL(C6)/AC for six PFAS were 1.40-1.96 times higher than those of pristine AC in a surface water sample containing 2.6 mg/L dissolved organic carbon and millimolar-level divalent cation concentration. PFAS partitioning from the surface water to ILs was not hindered by dissolved organic matter and was enhanced by the divalent cations, indicating the advantages of IL/ACs for treating significant amounts of PFAS in water. The synthesized IL/ACs were effective at treating coexisting pharmaceutical and personal-care products in surface water, showcasing their versatility for treating a broad range of water micropollutants.

Whitening Efficacy of Toothpastes on Coffee-Stained Teeth: An Enamel Surface Analysis.

AIM: This study aimed to identify the optimal toothpaste for removing coffee-induced stains while also evaluating its impact on tooth enamel through roughness and abraded depth parameters, providing a comprehensive understanding of their effects. MATERIALS AND METHODS: Three whitening toothpastes and 2 conventional toothpastes were prepared for a simulated brushing procedure on coffee-stained bovine enamel tooth specimens. Using a toothbrushing machine, up to 10,000 brushstrokes were completed, while spectrophotometric readings were taken at designated intervals. A mixed-effects model for statistical analysis determined the effects of toothpaste and brushing on colour change, roughness, and abraded depth. RESULTS: Whitening toothpastes significantly deviated from the control (P < .001, P < .001, and P < .003, respectively), whereas the conventional toothpaste did not exhibit a significant contrast (P < .081). Regarding colour restoration following coffee staining, whitening toothpastes showed higher restoration than conventional toothpastes. Surface roughness and abraded depth parameters increased with accumulated brushing. CONCLUSIONS: Sodium hexametaphosphate-containing toothpaste demonstrated the highest efficacy in removing coffee-induced stains and restoring tooth colour. Nevertheless, this stronger whitening effect was associated with increased abrasion. While conventional toothpastes exhibited some whitening effects, the most substantial improvement in lightness was consistently observed with whitening toothpastes. CLINICAL RELEVANCE: Understanding how whitening toothpaste affects enamel integrity is crucial for refining formulations and advancing dental care. This knowledge lays the groundwork for more effective oral care products and improved whitening procedures, ultimately enhancing the overall quality of dental treatments.

Unveiling the oxidation mechanism of persistent organic contaminants via visible light-induced dye-sensitized reaction by red mud suspension with peroxymonosulfate.

A dye-sensitized photocatalysis system was developed for degrading persistent organic contaminants using solid waste (i.e., red mud, RM) and peroxymonosulfate (PMS) under visible light. Complete degradation of acid orange 7 (AO7) was achieved in RM suspension with PMS, where the co-existence of amorphous FeO(OH)/α-Fe2O3 was the key factor for PMS activation. The experimental results obtained from photochemical and electrochemical observations confirmed the enhanced PMS activation due to the Fe-OH phase in RM. DFT calculations verified the acceleration of PMS activation due to the high adsorption energy of PMS on FeO(OH) and low energy barrier for generating reactive radicals. Compared to the control experiment without AO7 showing almost no degradation of other organic contaminants (phenol, bisphenol A, 4-chlorophenol, 4-nitrophenol, and benzoic acid), photo-sensitized AO7* enhanced electron transfer in the FeIII/FeII cycle, dramatically enhancing the degradation of organic contaminants via radical (•OH, SO4•-, and O2•-) and non-radical (dye*+ and 1O2) pathways. Therefore, the novel finding of this study can provide new insights for unique PMS activation by heterogeneous Fe(III) containing solid wastes and highlight the importance of sensitized dye on the interaction of PMS with Fe charge carrier for the photo-oxidation of organic contaminants under visible light.

Unveiling interfacial interaction between antimony oxyanions and boehmite nanorods: Spectroscopic evidence and density functional theory analysis.

In natural environments, the fate and migratory behavior of metalloid contaminants such as antimony (Sb) significantly depend on the interfacial reactivity of mineral surfaces. Although boehmite (γ-AlOOH) is widely observed in (sub)surface environments, its underlying interaction mechanism with Sb oxyanions at the molecular scale remains unclear. Considering Sb-contaminated environmental conditions in this study, we prepared boehmite under weakly acidic conditions for use in the systematic investigation of interfacial interactions with Sb(III) and Sb(V). The as-synthesized boehmite showed a nanorod morphology and comprised four crystal facets in the following order: 48.4% (010), 27.1% (101), 15.0% (001), and 9.5% (100). The combined results of spectroscopic analyses and theoretical calculations revealed that Sb(III) formed hydrogen bonding outer-sphere complexation on the (100), (010), and (001) facets and that Sb(V) preferred to form bidentate inner-sphere complexation via mononuclear edge-sharing configuration on the (100), (001), and (101) facets and binuclear corner-sharing configuration on the (010) facet. These findings indicate that the facet-mediated thermodynamic stability of the surface complexation determines the interaction affinity toward the Sb species. This work is the first to document the contribution of boehmite to (sub)surface media, improving the ability to forecast the fate and behavior of Sb oxyanions at mineral-water interfaces.

Electrochemical production of hydroxylamine from nitrate on metal electrodes: A comparative study of selectivity and efficiency.

Despite the great potential of electrochemical nitrate reduction as a hydroxylamine production method, this strategy has not been sufficiently examined, and the effects of electrode material type on the selectivity and efficiency of this reduction remain underexplored. To bridge this gap, the present study evaluated six metals (Ag, Cu, Ni, Sn, Ti, and Zn) as cathode materials for the electrochemical reduction of nitrate to hydroxylamine, showing that the selectivity of hydroxylamine production was maximal for Sn, while the corresponding faradaic and energy utilization efficiencies were maximal for Ti. Although all tested materials favored nitrate reduction over hydrogen evolution, the disparity in the onset potentials of these reactions did not adequately explain the variations in nitrate removal efficiency, which was found to be influenced by material resistance and charge-transfer properties. The rate constants of elementary nitrate reduction steps determined from the time-dependent concentrations of nitrate and its reduction products (nitrous acid, hydroxylamine, and ammonium) were used to calculate the selectivity and efficiency of hydroxylamine production for each electrode. In turn, these selectivities and efficiencies were correlated with the density functional theory-computed adsorption energies of a key hydroxylamine precursor on different electrodes to afford a volcano-type plot with Ti and Sn at its pinnacle. Thus, this study introduces valuable descriptors and methods for the further screening of electrocatalysts for hydroxylamine generation and the establishment of more environmentally friendly hydroxylamine production techniques utilizing sustainable electricity.

Insight into disparate nonradical mechanisms of peroxymonosulfate and peroxydisulfate activation by N-doped oxygen-rich biochar: Unraveling the role of active sites.

In this study, we first comprehensively studied peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation mechanisms using N, O codoped sludge biochar (NOSB) to degrade organics from water. Among the catalysts, NOSB with a higher content of graphitic N, optimal edge nitrogen (pyridinic N and pyrrolic N), CO groups, sp2-hybridized C, and rich defects were demonstrated to be a superior catalyst. Therefore, by activating PDS and PMS, NOSB exhibited the highest rate of BPA degradation, which was 22-fold and 13-fold that of pristine sludge biochar, respectively. However, owing to different oxidation potentials and molecular structures, PMS and PDS show different degradation performances due to various catalytic mechanisms occurring, even with the same biochar. Due to the asymmetrical structure of PMS, electrons passed from PMS to NOSB and further generated singlet oxygen (1O2), which governs the degradation of bisphenol A with an auxiliary contribution of single electron transfer. Meanwhile, PDS is reduced at the Lewis basic sites of NOSB, forming inner-surface-bound {PDS-NOSB}, which was oxidizing around neighboring carbon and decomposed targets through transferring single and double electrons. NOSB is promising for practical applications because of its adaptation to a wide pH range, anions, high total organic carbon removal, tunable active sites, and re-usability for degrading organics via PMS/PDS activation. This study unveils knowledge about N, O codoped sludge biochar catalysts for activating PMS/PDS and advocates a great approach for organics' degradation in the environment.

Virucidal activity of Cu-doped TiO2 nanoparticles under visible light illumination: Effect of Cu oxidation state.

Copper (Cu) is an effective antimicrobial material; however, its activity is inhibited by oxidation. Titanium dioxide (TiO2) photocatalysis prevents Cu oxidation and improves its antimicrobial activity and stability. In this study, the virucidal efficacy of Cu-doped TiO2 nanoparticles (Cu-TiO2) with three different oxidation states of the Cu dopant (i.e., zero-valent Cu (Cu0), cuprous (CuI), and cupric (CuII) oxides) was evaluated for the phiX174 bacteriophage under visible light illumination (Vis/Cu-TiO2). CuI-TiO2 exhibited superior virucidal activity (5 log inactivation in 30 min) and reusability (only 11 % loss of activity in the fifth cycle) compared to Cu0-TiO2 and CuII-TiO2. Photoluminescence spectroscopy and photocurrent measurements showed that CuI-TiO2 exhibited the highest charge separation efficiency and photocurrent density (approximately 0.24 µA/cm2) among the three materials, resulting in the most active redox reactions of Cu. Viral inactivation tests under different additives and viral particle integrity analyses (i.e., protein oxidation and DNA damage analyses) revealed that different virucidal species played key roles in the three Vis/Cu-TiO2 systems; Cu(III) was responsible for the viral inactivation by Vis/CuI-TiO2. The Vis/CuI-TiO2 system exhibited substantial virucidal performance for different viral species and in different water matrices, demonstrating its potential practical applications. The findings of this study offer valuable insights into the design of effective and sustainable antiviral photocatalysts for disinfection.

Three methods to measure the photopolymerization kinetics for different radiant emittance and composite type.

Photopolymerization kinetics affects the curing time, degree of conversion, polymerization shrinkage, and mechanical properties of composites. The aim of this study was to compare three methods (temperature, heat flow, and polymerization shrinkage) for photopolymerization kinetics measurement of composites. The photopolymerization kinetics of four composites (2 packable and 2 flowable) were measured with an LED light for 20 s (radiant emittance: 2,100 mW/cm2). For the two packable composites, photopolymerization kinetics was measured with varying the radiant emittance and exposure time. For each measurement method, peak times were determined as the time when maximum temperature rise, heat flow, and shrinkage rate occurred, respectively. The photopolymerization kinetics differed among the measurement methods. The photopolymerization kinetics of composites changed as the radiant emittance and composite type varied. In clinical practice and research on the composite restoration, the kinetics should be considered comprehensively with the complementary use of various measurement methods.

Long-term Outcomes of Polytetrafluoroethylene Bicuspid Pulmonary Valve Replacement.

BACKGROUND: In 2016 we reported promising midterm outcomes of bicuspid pulmonary valve replacement using 0.1-mm polytetrafluoroethylene (PTFE) membrane. This follow-up study analyzes long-term outcomes and risk factors for reintervention and structural valve deterioration (SVD). METHODS: We performed a retrospective review of the original 119 patients who underwent PTFE bicuspid pulmonary valve replacement. Median patient age was 16.9 years (range, 0.4-57.1). Reintervention was defined as any surgical or percutaneous catheter procedure on the PTFE valve. SVD was defined as development of a peak pressure gradient ≥ 50 mm Hg or at least a moderate amount of pulmonary regurgitation on follow-up echocardiography. RESULTS: The median follow-up duration was 9.5 years. The survival rate was 96.5% at 5 and 10 years, with 2 early and 2 late mortalities. Freedom from reintervention was 90.0% at 5 years and 63.3% at 10 years. Freedom from SVD was 92.8% at 5 years and 51.1% at 10 years, with regurgitation the predominant mode (64.6%). Freedom from both reintervention and SVD at 5 and 10 years were 89.1% and 49.5%, respectively. Multivariable analysis identified smaller valve diameter (hazard ratio, 0.82; P < .001) and more than trivial pulmonary regurgitation at discharge (hazard ratio, 5.81; P < .001) as risk factors for reintervention or SVD. CONCLUSIONS: Long-term results of the PTFE bicuspid pulmonary valve replacement were acceptable. However, improvements may be needed to reduce technical error and improve durability. Smaller valve diameter and more than trivial pulmonary regurgitation at discharge were risk factors for reintervention or SVD, warranting careful follow-up for timely reintervention.

Fabrication of biodegradable cellulose acetate nanofibers containing Rose Bengal dye by electrospinning technique and their antiviral efficacy under visible light irradiation.

Biodegradable cellulose acetate (CA) nanofibers containing Rose Bengal (RB) dye were fabricated by electrospinning technique. RB dye, an anionic photosensitizer, has been used in photodynamic therapy due to its excellent biocompatibility and ability to absorb light to generate reactive oxygen species (ROS), but has a decisive disadvantage of water solubility on infection prevention. Firstly, water-insoluble RB dye was synthesized through complexation with cationic ionic liquid (IL) for antiviral agents. The synthesized water-insoluble RB dyes were embedded into biodegradable CA nanofibers by electrospinning. The electrospun nanofibers passed both antiviral test for φx174 virus under visible light irradiation and biodegradability-test using enzymes. The fabricated RB nanofibers absorbed light and generated ROS to inactivate the virus. As a result, the log reduction (-Log10(N/N0)) of φx174 titer under visible light reached a detection limit of 5.00 within 30 min. Also, the fabricated nanofibers were degraded up to 34 wt % in 9 weeks by lipase and cellulase enzymes compared with non-biodegradable nanofibers.

Bridging the Catalytic Turnover Gap Between Single-Atom Iron Nanozymes and Natural Enzymes by Engineering the First and Second Shell Coordination.

Single-atom nanozymes (SAzymes) constitute a promising category of enzyme-mimicking materials with outstanding catalytic performance. The performance of SAzymes improves through modification of the coordination environments around the metal center. However, the catalytic turnover rates of SAzymes, which are key measures of the effectiveness of active site modifications, remain lower than those of natural enzymes, especially in peroxidase-reactions. Here, the first and second shell coordination tuning strategy that yields SAzymes with structures and activities analogous to those of natural enzymes is reported. The optimized SAzyme exhibits a turnover rate of 52.7 s-1 and a catalytic efficiency of 6.97 × 105 M-1 s-1 . A computational study reveals that axial S-ligands induce an alternative reaction mechanism, and SO2 - functional groups provide hydrogen bonds to reduce the activation energy. In addition, SAzyme shows superior anti-tumor ability in vitro and in vivo. These results demonstrate the validity of coordination engineering strategies and the carcinostatic potential of SAzymes.

Mg-incorporated sorbent for efficient removal of trace CO from H2 gas.

Removal of trace CO impurities is an essential step in the utilization of Hydrogen as a clean energy source. While various solutions are currently employed to address this challenge, there is an urgent need to improve their efficiency. Here, we show that a bead-structured Mg, Cu, and Ce-based sorbent, Mg13CuCeOx, demonstrates superior removal capacity of trace CO from H2 with high stability. The incorporation of Mg boosts sorption performance by enhancing the porous structure and Cu+ surface area. Remarkably, compared to existing pelletized sorbents, Mg13CuCeOx exhibits 15.5 to 50 times greater equilibrium capacity under pressures below 10 Pa CO and 31 times longer breakthrough time in removing 50 ppm CO in H2. Energy-efficient oxidative regeneration using air at 120 °C allows its stable sorption performance over 20 cycles. Through in-situ DRIFTS analysis, we elucidate the reaction mechanism that Mg augments the surface OH groups, promoting the formation of bicarbonate and formate species. This study highlights the potential of MgCuCeOx sorbents in advancing the hydrogen economy by effectively removing trace CO from H2.

Highly Efficient Nitrogen-Fixing Microbial Hydrogel Device for Sustainable Solar Hydrogen Production.

Conversion of sunlight and organic carbon substrates to sustainable energy sources through microbial metabolism has great potential for the renewable energy industry. Despite recent progress in microbial photosynthesis, the development of microbial platforms that warrant efficient and scalable fuel production remains in its infancy. Efficient transfer and retrieval of gaseous reactants and products to and from microbes are particular hurdles. Here, inspired by water lily leaves floating on water, a microbial device designed to operate at the air-water interface and facilitate concomitant supply of gaseous reactants, smooth capture of gaseous products, and efficient sunlight delivery is presented. The floatable device carrying Rhodopseudomonas parapalustris, of which nitrogen fixation activity is first determined through this study, exhibits a hydrogen production rate of 104 mmol h-1  m-2 , which is 53 times higher than that of a conventional device placed at a depth of 2 cm in the medium. Furthermore, a scaled-up device with an area of 144 cm2 generates hydrogen at a high rate of 1.52 L h-1  m-2 . Efficient nitrogen fixation and hydrogen generation, low fabrication cost, and mechanical durability corroborate the potential of the floatable microbial device toward practical and sustainable solar energy conversion.

Effect of translucency and absorbance of composite on temperature change during photopolymerization.

This study investigated the effect of translucency and absorbance of conventional (FiltekTM-Z350-XT) and bulk-fill (Tetric®-N-Ceram) composites on temperature change during photopolymerization, using a non-contact infrared sensor. Three shades from each composite were selected to prepare disk-shaped specimens (n=3), which then photopolymerized with LED-light for 20 s. A second light exposure was performed on the photopolymerized specimens. The first peak temperature rise during composite photopolymerization (ΔTtotal), second peak temperature rise by the light (ΔTlight), and net peak temperature rise by composite curing heat (ΔTcomposite) were obtained from the temperature change vs. time curve. The changes in ΔTtotal and ΔTlight with varying the composite shade were greater than those in ΔTcomposite. The conventional composite showed higher ΔTtotal and ΔTlight than bulk-fill composite. ΔTtotal and ΔTlight increased as translucency parameter decreased, and absorbance increased. The potential risk for heat-induced pulpal damage should be considered when selecting a composite shade, especially for deep cavities.

Real-time morphological detection of label-free submicron-sized plastics using flow-channeled differential interference contrast microscopy.

Owing to the surge in plastic waste generated during the COVID-19 pandemic, concerns regarding microplastic pollution in aqueous environments are increasing. Since microplastics (MPs) are broken down into submicron (< 1 µm) and nanoscale plastics, their real-time morphological detection in water is necessary. However, the decrease in the scattering cross-section of MPs in aqueous media precludes morphological detection by bright-field microscopy. To address this problem, we propose and demonstrate a differential interference contrast (DIC) system that incorporates a magnification-enhancing system to detect MPs in aqueous samples. To detect MPs in both the stationary and mobile phases, a microfluidic chip was designed, taking into consideration the imaging depth of focus and flow resistance. MPs of various sizes flowing in deionized, tap, and pond water at varying speeds were observed under Static and Flow conditions. Successful real-time morphological detection and quantification of polystyrene beads down to 200 nm at a constant flow rate in water were achieved. Thus, the proposed novel method can significantly reduce analysis time and improve the size-detection limit. The proposed DIC microscopy system can be coupled with Raman or infrared spectroscopy in future studies for chemical composition analysis. ENVIRONMENTAL IMPLICATION: Microplastics (MPs), particularly submicron plastics < 1-µm, can pose a risk to human health and aquatic ecosystems. Existing methods for detecting MPs in the aqueous phase have several limitations, including the use of expensive instruments and prolonged and labor-intensive procedures. Our results clearly demonstrated that a new low-cost flow-channeled differential interference contrast microscopy enables the real-time morphological detection and quantification of MPs down to 200 nm under flowing conditions without sample labeling. Consequently, our proposed rapid method for accurate quantitative measurements can serve as a valuable reference for detecting submicron plastics in water samples.

Removal of the red tide dinoflagellate Cochlodinium polykrikoides using chemical disinfectants.

For decades, red tide control has been recognized as necessary for mitigating financial damage to fish farms. Chemical disinfectants, frequently used for water disinfection, can reduce the risk of red tides on inland fish farms. This study systematically evaluated four different chemical disinfectants (ozone (O3), permanganate (MnO4-), sodium hypochlorite (NaOCl), and hydrogen peroxide (H2O2)) for their potential use in inland fish farms to control red tides by investigating their (i) inactivation efficacy regarding C. polykrikoides, (ii) total residual oxidant and byproduct formation, and (iii) toxicity to fish. The inactivation efficacy of C. polykrikoides cells by chemical disinfectants from highest to lowest followed the order of O3 > MnO4- > NaOCl > H2O2 for different cell density conditions and disinfectant doses. The O3 and NaOCl treatments generated bromate as an oxidation byproduct by reacting with bromide ions in seawater. The acute toxicity tests of the disinfectants for juvenile red sea bream (Pagrus major) showed that 72-h LC50 values were 1.35 (estimated), 0.39, 1.32, and 102.61 mg/L for O3, MnO4-, NaOCl, and H2O2, respectively. Considering the inactivation efficacy, exposure time of residual oxidants, byproduct formation, and toxicity toward fish, H2O2 is suggested as the most practical disinfectant for controlling red tides in inland fish farms.

Enhanced oxidation of urea by pH swing during chlorination: pH-dependent reaction mechanism.

Urea reacts with chlorine to form chlorinated ureas (chloroureas), and fully chlorinated urea (tetrachlorourea) is further hydrolyzed into CO2 and chloramines. This study found that the oxidative degradation of urea by chlorination was enhanced by the pH swing, wherein the reaction proceeded under an acidic pH (e.g., pH = 3) in the first stage, and the solution pH was subsequently increased to a neutral or alkaline value (e.g., pH > 7) in the second-stage reaction. The degradation rate of urea by pH-swing chlorination increased with increasing chlorine dose and pH during the second-stage reaction. The pH-swing chlorination was based on the opposite pH dependence of sub-processes comprising urea chlorination. The formation of monochlorourea was favored under acidic pH conditions; however, the subsequent conversion into di- and trichloroureas was favored under neutral or alkaline pH conditions. The deprotonation of monochlorourea (pKa = 9.7 ± 1.1) and dichlorourea (pKa = 5.1 ± 1.4) was suggested to be responsible for the accelerated reaction in the second stage under increased pH conditions. pH-swing chlorination was also effective in degrading urea at low concentrations (micromolar levels). In addition, the total nitrogen concentration significantly decreased during the degradation of urea because of the volatilization of chloramines and the release of other gaseous nitrogen compounds.

Historical Review and Future of Cardiac Xenotransplantation.

Along with the development of immunosuppressive drugs, major advances on xenotransplantation were achieved by understanding the immunobiology of xenograft rejection. Most importantly, three predominant carbohydrate antigens on porcine endothelial cells were key elements provoking hyperacute rejection: α1,3-galactose, SDa blood group antigen, and N-glycolylneuraminic acid. Preformed antibodies binding to the porcine major xenoantigen causes complement activation and endothelial cell activation, leading to xenograft injury and intravascular thrombosis. Recent advances in genetic engineering enabled knock-outs of these major xenoantigens, thus producing xenografts with less hyperacute rejection rates. Another milestone in the history of xenotransplantation was the development of co-stimulation blockaded strategy. Unlike allotransplantation, xenotransplantation requires blockade of CD40-CD40L pathway to prevent T-cell dependent B-cell activation and antibody production. In 2010s, advanced genetic engineering of xenograft by inducing the expression of multiple human transgenes became available. So-called 'multi-gene' xenografts expressing human transgenes such as thrombomodulin and endothelial protein C receptor were introduced, which resulted in the reduction of thrombotic events and improvement of xenograft survival. Still, there are many limitations to clinical translation of cardiac xenotransplantation. Along with technical challenges, zoonotic infection and physiological discordances are major obstacles. Social barriers including healthcare costs also need to be addressed. Although there are several remaining obstacles to overcome, xenotransplantation would surely become the novel option for millions of patients with end-stage heart failure who have limited options to traditional therapeutics.

Impact of Pulmonary Arterial Elastance on Right Ventricular Mechanics and Exercise Capacity in Repaired Tetralogy of Fallot.

BACKGROUND AND OBJECTIVES: Pathophysiological changes of right ventricle (RV) after repair of tetralogy of Fallot (TOF) are coupled with a highly compliant low-pressure pulmonary artery (PA) system. This study aimed to determine whether pulmonary vascular function was associated with RV parameters and exercise capacity, and its impact on RV remodeling after pulmonary valve replacement. METHODS: In a total of 48 patients over 18 years of age with repaired TOF, pulmonary arterial elastance (Ea), RV volume data, and RV-PA coupling ratio were calculated and analyzed in relation to exercise capacity. RESULTS: Patients with a low Ea showed a more severe pulmonary regurgitation volume index, greater RV end-diastolic volume index, and greater effective RV stroke volume (p=0.039, p=0.013, and p=0.011, respectively). Patients with a high Ea had lower exercise capacity than those with a low Ea (peak oxygen consumption [peak VO2] rate: 25.8±7.7 vs. 34.3±5.5 mL/kg/min, respectively, p=0.003), while peak VO2 was inversely correlated with Ea and mean PA pressure (p=0.004 and p=0.004, respectively). In the univariate analysis, a higher preoperative RV end-diastolic volume index and RV end-systolic volume index, left ventricular end-systolic volume index, and higher RV-PA coupling ratio were risk factors for suboptimal outcomes. Preoperative RV volume and RV-PA coupling ratio reflecting the adaptive PA system response are important factors in optimal postoperative results. CONCLUSIONS: We found that PA vascular dysfunction, presenting as elevated Ea in TOF, may contribute to exercise intolerance. However, Ea was inversely correlated with pulmonary regurgitation (PR) severity, which may prevent PR, RV dilatation, and left ventricular dilatation in the absence of significant pulmonary stenosis.

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.