Effect of 5% albumin on endothelial glycocalyx degradation during off-pump coronary artery bypass.

PURPOSE: The integrity of the endothelial glycocalyx (EG), a critical player in vascular homeostasis, reportedly influences the outcomes of critically ill patients. We investigated the effect of 5% albumin, which preserved EG integrity in preclinical studies, vs balanced crystalloid solution on EG degradation in patients undergoing off-pump coronary surgery. METHODS: Patients were randomized to receive either 5% albumin (N = 51) or balanced crystalloid solution (Plasma-Lyte [Baxter Incorporated, Seoul, Republic of Korea]; N = 53) for intravenous volume replacement during surgery (double-blinded). The primary outcome was plasma syndecan-1 concentration, a marker of EG degradation, measured after anesthetic induction (baseline), completion of grafting, and sternal closure. Secondary outcomes were atrial natriuretic peptide (ANP), tumour necrosis factor (TNF)-α, soluble thrombomodulin, and perioperative fluid balance. RESULTS: The mean (standard deviation) fluid requirements were 833 (270) mL and 1,323 (492) mL in the albumin and Plasma-Lyte group, respectively (mean difference, -489 mL; 95% confidence interval [CI], -643 to -335; P < 0.001). Plasma syndecan-1 concentration increased after completion of grafting (median difference, 116 ng·mL-1; 95% CI, 67 to 184; P < 0.001) and sternal closure (median difference, 57 ng·mL-1; 95% CI, 36 to 80; P < 0.001) compared with those at baseline, without any intergroup differences. Atrial natriuretic peptide, TNF-α, and soluble thrombomodulin concentrations were similar between the two groups. The amount of chest tube drainage was greater in the albumin group than that in the Plasma-Lyte group (median difference, 190 mL; 95% CI, 18 to 276; P = 0.03). CONCLUSION: Off-pump coronary surgery was associated with significant EG degradation. Yet, intraoperative fluid therapy with 5% albumin could not ameliorate EG degradation when compared with balanced crystalloid solution. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03699462); first posted 9 October 2018.

RéSUMé: OBJECTIF: L'intégrité du glycocalyx endothélial (GE), un acteur essentiel de l'homéostasie vasculaire, influencerait le devenir des patient·es gravement malades. Nous avons étudié l'effet de l'albumine à 5 %, qui préservait l'intégrité du GE dans les études précliniques, par rapport à une solution cristalloïde équilibrée sur la dégradation du GE chez les patient·es bénéficiant d'une chirurgie coronarienne à cœur battant. MéTHODE: Les patient·es ont été randomisé·es à recevoir soit de l'albumine à 5 % (N = 51) ou de la solution cristalloïde équilibrée (Plasma-Lyte [Baxter Incorporated, Séoul, République de Corée]; N = 53) pour le remplacement du volume intraveineux pendant la chirurgie (en double aveugle). Le critère d'évaluation principal était la concentration plasmatique de syndécan-1, un marqueur de la dégradation du GE, mesurée après l'induction de l'anesthésie (ligne de base), la fin de la greffe et la fermeture du sternum. Les critères d'évaluation secondaires étaient le peptide natriurétique auriculaire (ANP), le facteur de nécrose tumorale (TNF)-α, la thrombomoduline soluble et le bilan hydrique périopératoire. RéSULTATS: Les besoins liquidiens moyens (écart type) étaient de 833 (270) mL et 1323 (492) mL dans les groupes albumine et Plasma-Lyte, respectivement (différence moyenne, −489 mL; intervalle de confiance [IC] à 95 %, −643 à −335; P < 0,001). La concentration plasmatique de syndécan-1 a augmenté après la fin de la greffe (différence médiane, 116 ng·mL−1; IC 95 %, 67 à 184; P < 0,001) et la fermeture du sternum (différence médiane, 57 ng·mL−1; IC 95 %, 36 à 80; P < 0,001) par rapport aux concentrations au départ, sans différences intergroupe. Les concentrations de peptide natriurétique auriculaire, de TNF-α et de thrombomoduline soluble étaient similaires entre les deux groupes. La quantité de drainage du drain thoracique était plus importante dans le groupe albumine que dans le groupe Plasma-Lyte (différence médiane, 190 mL; IC 95 %, 18 à 276; P = 0,03). CONCLUSION: La chirurgie coronarienne à cœur battant a été associée à une dégradation significative du glycocalyx endothélial. Pourtant, la fluidothérapie peropératoire avec 5 % d'albumine n'a pas pu améliorer la dégradation du GE par rapport à une solution cristalloïde équilibrée. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03699462); enregistrée pour la première fois le 9 octobre 2018.

Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of Bifidobacterium longum subsp. suis.

Bifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-l-arabinofuranosidases (ABFs) and endo-α-1,5-l-arabinanases (ABNs) are required for efficient arabinan degradation. In this study, the putative gene cluster for arabinan degradation was discovered in the genome of Bifidobacterium longum subsp. suis. It consists of a variety of genes encoding exo- and endo-hydrolases, sugar-binding proteins, ABC-binding cassettes, and transcriptional regulators. Among them, two endo-ABNs GH43 (BflsABN43A and BflsABN43B), two exo-ABFs GH43 (BflsABF43A and BflsABF43B), and an exo-ABF GH51 (BflsABF51) were predicted to be the key hydrolases for arabinan degradation. These hydrolase genes were functionally expressed in Escherichia coli, and their enzymatic properties were characterized. Their synergism in arabinan degradation has been proposed from the detailed modes of action. Extracellular endo-BflsABN43A hydrolyzes sugar beet and debranched arabinans into the short-chain branched and linear AOS. Intracellularly, AOS can be further degraded into l-arabinose via the cooperative actions of endo-BflsABN43B, exo-BflsABF43A with debranching activity, α-1,5-linkage-specific exo-BflsABF43B, and exo-BflsABF51 with dual activities. The resulting l-arabinose is expected to be metabolized into energy through the pentose phosphate pathway by three enzymes expressed from the ara operon of bifidobacteria. It is anticipated that uncovering arabinan utilization gene clusters and their detailed functions in the genomes of diverse microorganisms will facilitate the development of customized synbiotics.

Effects of intraoperative inspired oxygen fraction (FiO2 0.3 vs 0.8) on patients undergoing off-pump coronary artery bypass grafting: the CARROT multicenter, cluster-randomized trial.

BACKGROUND: To maintain adequate oxygenation is of utmost importance in intraoperative care. However, clinical evidence supporting specific oxygen levels in distinct surgical settings is lacking. This study aimed to compare the effects of 30% and 80% oxygen in off-pump coronary artery bypass grafting (OPCAB). METHODS: This multicenter trial was conducted in three tertiary hospitals from August 2019 to August 2021. Patients undergoing OPCAB were cluster-randomized to receive either 30% or 80% oxygen intraoperatively, based on the month when the surgery was performed. The primary endpoint was the length of hospital stay. Intraoperative hemodynamic data were also compared. RESULTS: A total of 414 patients were cluster-randomized. Length of hospital stay was not different in the 30% oxygen group compared to the 80% oxygen group (median, 7.0 days vs 7.0 days; the sub-distribution hazard ratio, 0.98; 95% confidence interval [CI] 0.83-1.16; P = 0.808). The incidence of postoperative acute kidney injury was significantly higher in the 30% oxygen group than in the 80% oxygen group (30.7% vs 19.4%; odds ratio, 1.94; 95% CI 1.18-3.17; P = 0.036). Intraoperative time-weighted average mixed venous oxygen saturation was significantly higher in the 80% oxygen group (74% vs 64%; P < 0.001). The 80% oxygen group also had a significantly greater intraoperative time-weighted average cerebral regional oxygen saturation than the 30% oxygen group (56% vs 52%; P = 0.002). CONCLUSIONS: In patients undergoing OPCAB, intraoperative administration of 80% oxygen did not decrease the length of hospital stay, compared to 30% oxygen, but may reduce postoperative acute kidney injury. Moreover, compared to 30% oxygen, intraoperative use of 80% oxygen improved oxygen delivery in patients undergoing OPCAB. Trial registration ClinicalTrials.gov (NCT03945565; April 8, 2019).

Effect of Perioperative Intravenous Iron Supplementation for Complex Cardiac Surgery on Transfusion Requirements: A Randomized, Double-blinded Placebo-controlled Trial.

OBJECTIVES: We investigated whether routine perioperative intravenous iron replenishment reduces the requirement for packed erythrocytes (pRBC) transfusion. SUMMARY OF BACKGROUND DATA: Patients undergoing complex cardiac surgery are at high risk of developing postoperative iron deficiency anemia, thus requiring transfusion, which is associated with adverse outcomes. METHODS: Patients were randomized to receive either ferric derisomaltose 20 mg/kg (n = 103) or placebo (n = 101) twice during the perioperative period: 3 days before and after the surgery. The primary endpoint was the proportion of patients who received pRBC transfusion until postoperative day (POD) 10. Hemoglobin, reticulocyte count, serum iron profile, hepcidin, and erythropoietin were serially measured. RESULTS: pRBC was transfused in 60.4% and 57.2% of patients in the control and iron group, respectively (P = 0.651). Hemoglobin concentration at 3 weeks postoperatively was higher in the iron group than in the control group (11.6 ± 1.5 g/dL vs 10.9 ± 1.4 g/dL, P < 0.001). The iron group showed higher reticulocyte count [205 (150-267)×103/µL vs 164 (122-207)×103/µL, P = 0.003] at POD 10. Transferrin saturation and serum ferritin were significantly increased in the iron group than in the control group (P < 0.001). Serum hepcidin was higher in the iron group than in the control group at POD 3 [106.3 (42.9-115.9) ng/mL vs 39.3 (33.3-43.6) ng/mL, P < 0.001]. Erythropoietin concentration increased postoperatively in both groups (P = 0.003), with no between-group difference. CONCLUSIONS: Intravenous iron supplementation during index hospitalization for complex cardiac surgery did not minimize pRBC transfusion despite replenished iron store and augmented erythropoiesis, which may be attributed to enhanced hepcidin expression.

Remimazolam for General Anesthesia in a Patient with Severe Aortic Stenosis Undergoing High-Risk Surgery: A Case Report.

High-risk surgeries for patients with severe aortic stenosis (AS) are challenging for anesthesiologists and can result in hemodynamic deterioration and even mortality. We describe a case in which remimazolam was used to induce and maintain general anesthesia for a high-risk, noncardiac surgery accompanied by ongoing bleeding. An 86-year-old man with severe AS was scheduled to undergo proximal gastrectomy due to ongoing gastrointestinal bleeding and severe anemia. Remimazolam, a novel, ultra-short-acting benzodiazepine, was administered along with remifentanil for the induction and maintenance of general anesthesia. Throughout the anesthetic process, the patient's cardiac index and systemic vascular resistance were well preserved without any vasopressor support. Remimazolam seems to have possible effectiveness as a relatively safe agent for the induction and maintenance of general anesthesia in patients with severe AS who are undergoing high-risk, noncardiac surgery with bleeding.

Desorption technologies for remediation of cesium-contaminated soils: a short review.

This review summarizes the mechanisms for desorbing and extracting cesium (Cs+) from clay minerals and soil. Most techniques use ion exchange with acids, cations, polymers, and surfactants. Some improve desorption of Cs+ from clay minerals, while surfactants and polymers expand the interlayer. Mixtures of acids/polymers, acids/surfactants, cations/polymers, and cations/surfactants are therefore more effective agents for desorption of Cs+ from clay minerals. Hydrothermal treatment plays a role similar to that of polymers and surfactants in expanding the interlayer of clay minerals. The primary desorption mechanism expands the interlayer and desorbs Cs+, but multiple sequential extractions based on these techniques can more effectively desorb Cs+ from clay minerals and field-contaminated soils. Desorption techniques for Cs+ based on multiple sequential extractions can reportedly achieve an efficiency greater than 90%, and such approaches are likely to be important technologies for remediation of Cs+-contaminated soils and industrial accident sites, as well as the dismantling of nuclear power plants.

Bifunctional iron-modified graphitic carbon nitride (g-C3N4) for simultaneous oxidation and adsorption of arsenic.

Iron-modified graphitic carbon nitride (FG materials) was prepared through a simple and cost-effective method using iron oxide and melamine to achieve simultaneous oxidation and adsorption of arsenic. We hypothesized that graphitic carbon nitride oxidizes As(III) to As(V) under light irradiation, and the converted As(V) is adsorbed by the amorphous iron phase on FG materials. FG materials were characterized by X-ray diffraction, Fourier transform infrared spectra, field-emission scanning electron microscopy, specific surface area, ultraviolet-visible light spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy. As(III) was efficiently transformed to As(V) due to the photocatalytic-oxidation ability of graphic carbon nitride under visible and UV light irradiation, the oxidized As(V) was adsorbed by the amorphous iron phases, and As species were removed from the system. The removal efficiency of As(III) decreased from 50%, 41%, and 33% under UV light, visible light and dark, respectively. FG materials exhibited the photocatalytic-oxidation ability and adsorption capacity, and a synergistic effect was observed between graphitic carbon nitride and iron oxide. Removal of As can be achieved even under visible light, confirming the field applicability of low-cost FG materials.

Smart Contract-Based Review System for an IoT Data Marketplace.

Internet of Things (IoT)-based devices, especially those used for home automation, consist of their own sensors and generate many logs during a process. Enterprises producing IoT devices convert these log data into more useful data through secondary processing; thus, they require data from the device users. Recently, a platform for data sharing has been developed because the demand for IoT data increases. Several IoT data marketplaces are based on peer-to-peer (P2P) networks, and in this type of marketplace, it is difficult for an enterprise to trust a data owner or the data they want to trade. Therefore, in this study, we propose a review system that can confirm the reputation of a data owner or the data traded in the P2P data marketplace. The traditional server-client review systems have many drawbacks, such as security vulnerability or server administrator's malicious behavior. However, the review system developed in this study is based on Ethereum smart contracts; thus, this system is running on the P2P network and is more flexible for the network problem. Moreover, the integrity and immutability of the registered reviews are assured because of the blockchain public ledger. In addition, a certain amount of gas is essential for all functions to be processed by Ethereum transactions. Accordingly, we tested and analyzed the performance of our proposed model in terms of gas required.

Adequate sedation with single-dose dexmedetomidine in patients undergoing transurethral resection of the prostate with spinal anaesthesia: a dose-response study by age group.

BACKGROUND: Dexmedetomidine (DMT), a highly selective α2-adrenoceptor agonist, has been used safely as a sedative in patients under regional anesthesia. The purpose of this study was to determine the 50% effective dose (ED50) of single-dose DMT to induce adequate light sedation in elderly patients in comparison with younger patients undergoing transurethral resection of the prostate (TURP) with spinal anesthesia. METHODS: Forty-two male patients were recruited. The young age group (Group Y) included patients 45 to 64 years old and the old age group (Group O) included patients 65 to 78 years old. After the spinal anesthesia was performed, a pre-calculated dose of DMT was administered for 10 min. The Observer's Assessment of Alertness/Sedation (OAA/S) scale, bispectral index score (BIS) were assessed then at 2-min intervals for 20 min. A modified Dixon's up-and-down method was used to determine the ED50 of the drug for light sedation (OAA/S score 3/4). In the recovery room, regression times of the motor and sensory blocks were recorded. RESULTS: The ED50 of DMT was 0.25 (95% C.I. 0.15-0.35) µg/kg in Group O and 0.35 (95% C.I. 0.35-0.45) µg/kg in Group Y (p = 0.002). The ED95 was 33% lower in Group O compare with Group Y (0.38 (95% C.I. 0.29-0.39) µg/kg vs. 0.57 (95% C.I. 0.49-0.59) µg/kg). The regression time of sensory block was longer in Group O than in Group Y (109.0 ± 40.2 min vs. 80.0 ± 31.6 min) (p = 0.014). CONCLUSION: The single-dose of DMT for light sedation was lower by 21% in Group O compare with Group Y underwent TURP with spinal anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01665586. Registered July 31, 2012.

Electrochemical oxidation and mechanism of sulfanilamide from groundwater in a flow-through system using carbon fiber (CF) anode.

Metal-based anodes have been used for a long time in the electrochemical oxidation processes to remediate groundwater. However, the high cost of this technique as well as the release of potentially toxic metals (ex, lead), are major barriers being fully implemented. As an alternative of metal-based anodes, in recent years, carbon-based anodes have been paid attention due to their eco-friendliness and cost-effectiveness. This study evaluated the oxidation performance of carbon fiber (CF) anode in a flow-through system. The CF anode degraded 45-87% of the target pollutant (sulfanilamide), depending on the current intensity applied. However, no further degradation of sulfanilamide was observed after the cathode, indicating that sulfanilamide degradation occurred mainly at the anode. This study also determined the effect of electrolytes on electrochemical oxidation using chloride (Cl-), sulfate (SO42-), bicarbonate (CO3-), and synthetic groundwater. Cl- and SO42- electrolytes were converted electrochemically into active species, thereby enhancing sulfanilamide degradation, while the bicarbonate and groundwater electrolytes inhibited oxidation performance by scavenging hydroxyl radicals. A series of scavenger tests and characterization showed that the direct oxidation and hydroxyl radicals involved the sulfanilamide degradation. Especially, the production of hydroxyl radicals is more favorable in high currents than in low currents. That is, CF anode contributed to the degradation by direct oxidation of carbon-based electrodes and generation of hydroxyl radicals. In summary, this study highlights how a CF anode is capable of effectively degrading organic pollutants via anodic oxidation.

Anti-osteoporotic effects of Boswellia serrata gum resin extract in vitro and in vivo.

BACKGROUND/OBJECTIVES: This study evaluated the beneficial effects of an ethanol extract of Boswellia serrata gum resin (FJH-UBS) in osteoporosis. MATERIALS/METHODS: MC3T3-E1 osteoblastic cells and RAW 264.7 osteoclastic cells were treated with FJH-UBS. The alkaline phosphatase (ALP) activity, mineralization, collagen synthesis, osteocalcin content, and Runt-related transcription factor 2 (RUNX2) and Osterix expression were measured in MC3T3-E1 cells. The actin ring structures, tartrate-resistant acid phosphatase (TRAP) activity, and the nuclear factor of activator T-cells, cytoplasm 1 (NFATc1) expression were evaluated in RAW 264.7 cells. Ovariectomized ICR mice were orally administered FJH-UBS for eight weeks. The bone mineral density (BMD) and the serum levels of osteocalcin, procollagen 1 N-terminal propeptide (P1NP), osteoprotegerin, and TRAP 5b were analyzed. RESULTS: FJH-UBS increased the ALP activity, collagen, osteocalcin, mineralization, and RUNX2 and osterix expression in MC3T3-E1 osteoblastic cells, whereas it decreased the TRAP activity, actin ring structures, and NFATc1 expression in RAW 264.7 osteoclastic cells. In ovariectomy-induced osteoporosis mice, FJH-UBS positively restored all of the changes in the bone metabolism biomarkers (BMD, osteocalcin, P1NP, osteoprotegerin, and TRAP 5b) caused by the ovariectomy. CONCLUSION: FJH-UBS has anti-osteoporotic activity by promoting osteoblast activity and inhibiting osteoclast activity in vitro and in vivo, suggesting that FJH-UBS is a potential functional food ingredient for osteoporosis.

Prediction of arsenic retention in vadose zone based on empirical relationship between soil properties and segmented retardation factors.

Arsenic (As) is a widespread environmental contaminant that poses a significant threat to ecosystems and human health. Although previous studies have qualitatively revealed the effects of individual soil properties on the transport and fate of As in the vadose zone, their integrated impacts remain obscure. Moreover, studies investigating the retardation factor therein, which is a key parameter for comprehending As transport in the vadose zone, are extremely limited. In this study, we investigated the interplay of soil properties with As transport and retention within the vadose zone, while focusing on the retardation factor of As. We employed steady-state unsaturated water-flow soil column experiments coupled with a mobile-immobile model and multiple linear regression analysis to elucidate the dependence of As retardation factors on the soil properties. In the mobile water zone, iron and organic matter contents emerged as the two most influential properties that impedes As mobility. Whereas, in the immobile water zone, the coefficient of uniformity and bulk density were the most influential factors that enhanced As retention. Finally, we derived an empirical equation for calculating the As retardation factors in each zone, offering a valuable tool for describing and predicting As behavior to protect the groundwater resources underneath.

Immunoprotective Effect of Liver Allograft on Patients with Combined Liver and Kidney Transplantation.

BACKGROUND Simultaneous liver-kidney transplantation (SLKT) and kidney transplantation (KT) after liver transplantation (LT) provide potential treatment options for patients with end-stage liver and kidney disease. There is increasing attention being given to liver-kidney transplantation (LTKT), particularly regarding the immune-protective effects of the liver graft. This retrospective, single-center, observational study aimed to evaluate the clinical outcomes of KT in LTKT patients - either SLKT or KT after LT (KALT) - compared to KT alone (KTA). MATERIAL AND METHODS We included patients who underwent KT between January 2005 and December 2020, comprising a total of 4312 patients divided into KTA (n=4268) and LTKT (n=44) groups. The LTKT group included 11 SLKT and 33 KALT patients. To balance the difference in sample sizes between the 2 groups, we performed 3: 1 propensity score matching (PSM). RESULTS There was no significant difference in graft survival between the groups. However, the LTKT group exhibited significantly superior rejection-free survival compared to the KTA group (P.

Effect of erythropoietin on the incidence of acute kidney injury following complex valvular heart surgery: a double blind, randomized clinical trial of efficacy and safety.

INTRODUCTION: Recombinant human erythropoietin (EPO) is known to provide organ protection against ischemia-reperfusion injury through its pleiotropic properties. The aim of this single-site, randomized, case-controlled, and double-blind study was to investigate the effect of pre-emptive EPO administration on the incidence of postoperative acute kidney injury (AKI) in patients with risk factors for AKI undergoing complex valvular heart surgery. METHODS: We studied ninety-eight patients with preoperative risk factors for AKI. The patients were randomly allocated to either the EPO group (n = 49) or the control group (n = 49). The EPO group received 300 IU/kg of EPO intravenously after anesthetic induction. The control group received an equivalent volume of normal saline. AKI was defined as an increase in serum creatinine >0.3 mg/dl or >50% from baseline. Biomarkers of renal injury were serially measured until five days postoperatively. RESULTS: Patient characteristics and operative data, including the duration of cardiopulmonary bypass, were similar between the two groups. Incidence of postoperative AKI (32.7% versus 34.7%, P = 0.831) and biomarkers of renal injury including cystatin C and neutrophil gelatinase-associated lipocalin showed no significant differences between the groups. The postoperative increase in interleukin-6 and myeloperoxidase was similar between the groups. None of the patients developed adverse complications related to EPO administration, including thromboembolic events, throughout the study period. CONCLUSIONS: Intravenous administration of 300 IU/kg of EPO did not provide renal protection in patients who are at increased risk of developing AKI after undergoing complex valvular heart surgery. TRIAL REGISTRATION: Clinical Trial.gov, NCT01758861.

Novel electrochemical method to activate biochar derived from spent coffee grounds for enhanced adsorption of lead (Pb).

Biochar (BC) has received much attention as a promising adsorbent that can be exploited to remove heavy metals in domestic and wastewater. The adsorption capacity of BC is, however, relatively low compared to that of conventional adsorbents, and its performance is inversely proportional to its stability. Various chemical and physical methods have been tried to address these limitations, but BC activation still generates too much acidic or alkaline wastewater. Here we propose a novel electrochemical method and compare its lead (Pb) adsorption capacity to that of acid- and alkaline-based approaches. We found that electrochemical activation significantly increased the number of hydroxyl and carboxylic groups on the BC surface, which led to an increase in Pb absorption from 27 % (pristine BC) to 100 % because the oxygenated-functional groups contributed to the adsorption of Pb. Pb capacity was 1.36, 2.64, 3.31, and 5.00 mg g-1, corresponding to pristine, acidic, alkaline, and electrochemical activation, respectively. The Pb absorption capacity of electrochemically activated BC was also higher than that of acid- and alkali-activated BC, which we attribute to the observed increases in oxygen ratio and surface area. Moreover, the adsorption rate of BC after electrochemical activation was 190 times faster and its capacity was 2.4 times higher than that of pristine BC. These findings show that the electrochemical activation of BC results in greater adsorption capacity than conventional methods.

Mitigation of arsenic release by calcium peroxide (CaO2) and rice straw biochar in paddy soil.

Biochar has a great potential in the stabilization of soil heavy metals; however, the application can actually enhance the mobility of Arsenic (As) in soil. Here, a biochar-coupled calcium peroxide system was proposed to control the increase in As mobility caused by biochar amendment in paddy soil environment. The capability of rice straw biochar pyrolyzed at 500 °C (RB) and CaO2 to control As mobility was evaluated by incubation for 91 days. CaO2 encapsulation was performed for pH control of CaO2, and As mobility was evaluated using a mixture of RB + CaO2 powder (CaO2-p), and RB + CaO2 bead (CaO2-b), respectively. The control soil solely and RB alone were included for comparison. The combination of RB with CaO2 exhibited remarkable performance in controlling As mobility in soil, and As mobility decreased by 40.2% (RB + CaO2-p) and 58.9% (RB + CaO2-b) compared to RB alone. The result was due to high dissolved oxygen (6 mg L-1 in RB + CaO2-p and RB + CaO2-b) and calcium concentrations (296.3 mg L-1 in RB + CaO2-b); oxygen (O2) and Ca2+ derived from CaO2 is able to prevent the reductive dissolution and chelate-promoted dissolution of As bound to iron (Fe) oxide by biochar. This study revealed that the simultaneous application of CaO2 and biochar could be a promising way to mitigate the environmental risk of As.

Covalent immobilizing horseradish peroxidase on electrochemically-functionalized biochar for phenol removal.

Enzyme-based biocatalytic treatment has been known as an effective measure to biologically degrade organic pollutants. Advantageously, enzymes could be immobilized on solid supports, and such fact enables reuse/prolong the enzymatic capability. It could be of great importance to functionalize a support material for enhancing the immobilization efficiency/stability of enzymes. As such, this study laid great emphasis on covalent bonding to immobilize horseradish peroxidase (HRP) on a functionalized rice straw biochar with glutaraldehyde (GA) as a crosslinker. Biochar was pretreated by the electrochemical method and the acid treatment respectively to enrich the oxygen-containing functional groups. These led to the enhanced immobilizing ability of biochar. The HRP immobilized on the electrochemically-functionalized biochar (HRP-EBC) showed three times as much enzyme activity as the HRP directly adsorbed onto biochar. The HRP immobilized on the acid-functionalized biochar (HRP-ABC) showed activity similar to that of HRP-EBC. It was concluded that both the (acid/electrochemical) pretreatments are effective to enhance enzyme immobilization. Nevertheless, the electrochemical functionalized method of biochar is chemical oxidant-free, and one important lesson from a series of tests was that the pretreatment of biochar through the electrochemical method could be more environmentally benign. Moreover, employing HRP-EBC could be beneficial from a perspective of a real environmental practice considering its higher pH, thermal stability, and good reusability. 80% of phenol was degraded in 1 h in the presence of HRP-EBC when pH was 7.0 and a ratio of H2O2 to phenol was 1:1.5.

Enhancing adoptive T-cell therapy with fucoidan-based IL-2 delivery microcapsules.

Adoptive cell therapy (ACT) with antigen-specific T cells is a promising treatment approach for solid cancers. Interleukin-2 (IL-2) has been utilized in boosting the efficacy of ACT. However, the clinical applications of IL-2 in combination with ACT is greatly limited by short exposure and high toxicities. Herein, a complex coacervate was designed to intratumorally deliver IL-2 in a sustained manner and protect against proteolysis. The complex coacervate consisted of fucoidan, a specific IL-2 binding glycosaminoglycan, and poly-l-lysine, a cationic counterpart (FPC2). IL-2-laden FPC2 exhibited a preferential bioactivity in ex vivo expansion of CD8+T cells over Treg cells. Additionally, FPC2 was embedded in pH modulating injectable gel (FPC2-IG) to endure the acidic tumor microenvironment. A single intratumoral administration of FPC2-IG-IL-2 increased expansion of tumor-infiltrating cytotoxic lymphocytes and reduced frequencies of myeloid populations. Notably, the activation and persistency of tumor-reactive T cells were observed only in the tumor site, not in the spleen, confirming a localized effect of FPC2-IG-IL-2. The immune-favorable tumor microenvironment induced by FPC2-IG-IL-2 enabled adoptively transferred TCR-engineered T cells to effectively eradicate tumors. FPC2-IG delivery system is a promising strategy for T-cell-based immunotherapies.

Control of arsenic release from paddy soils using alginate encapsulated calcium peroxide.

The mobilization of As in paddy soils is affected by iron redox cycles. In this regard, calcium peroxide (CaO2) can be used as an alternative to maintaining oxidizing conditions by liberating oxygen under flooding environments. Nevertheless, the problem of increase in pH by CaO2 dissolution remains unresolved. In this study, the encapsulation of CaO2 using alginate is proposed. Encapsulated CaO2 (CaO2-b) using 1% sodium alginate was applied to As-contaminated soil to evaluate the ability of pH control and As mobility during flooding conditions. The pH increased rapidly from 6.8 to 9.0 in unencapsulated CaO2 (CaO2-p) within 1 day, while CaO2-b increased slowly to 8.6 over 91 days. CaO2 created an oxidizing condition in the soil by providing oxygen, thus effectively prevented the reductive dissolution of iron. The mobility of As decreased by 50% (CaO2-p) and 83% (CaO2-b) compared with that of the control soil. Furthermore, the As in pore water was three times lower than CaO2-p because CaO2-b released 1.8 times more Ca2+ to form Ca-As complexes than CaO2-p. Consequently, the encapsulated CaO2 reduced the negative effects of CaO2 treatment on increasing pH of the soil and furnished a better environmental condition for inhibiting As mobility.

Simultaneous oxidation and analysis of TOC-TN-TP in one pot reactor.

Total organic carbon (TOC), total nitrogen (TN), and total phosphorous (TP) are the most common indicators of water quality. The analytical processes of the indicators require oxidation of any type of C, N, and P to carbon dioxide, nitrate, and phosphate as final products. Persulfate is the recommended oxidant for these transformations. In this study, co-oxidation was suggested for the simultaneous analysis of TOC-TN-TP. A single oxidizing reactor using persulfate was proposed instead of three individual systems. The system oxidizes complex organic chemicals to carbon dioxide, nitrate, and phosphate. However, the residual persulfate after oxidation interferes with the spectrophotometric analysis of nitrate and phosphate. Therefore, in the proposed system, the complete transformation of persulfate is a key factor for simultaneous analysis. In this system, ultraviolet irradiation for 30 min under alkaline conditions converted residual persulfate to sulfate. The complete transformation eliminated persulfate interference in nitrate and phosphate detection. In the proposed system with a single oxidation reactor, TOC, TN, and TP were oxidized and analyzed simultaneously within 15% of the analytical error range compared to the standard test method.