Superoxide Radical Formation Research Articles

Sunlight‐Induced Degradation of Dissolved Ethyl‐Parathion and Coupled Molecular Toxicity Investigation

AbstractEthyl‐parathion (EP) is a globally‐distributed organophosphorus (OP) pesticide where environmental release is a standard use case. The present study sought to determine if sunlight degraded EP and if the degraded products were toxic to biological molecules in cell‐free assays. A 24 mg/L solution of EP (water solubility limit) was exposed to direct sunlight for 0, 1, 2, 3 and 4 hrs where as much as 64.6 % of EP was degraded relative to the 0 hr sunlight exposure. Singlet oxygen formation (1O2) increased by 15.9, 20.6, 29.8, and 64.4 % in the 1, 2, 3 and 4 hr sunlight exposures, respectively. Ultra‐high performance liquid chromatography further confirmed the sunlight‐induced transformation of EP and the increased 1O2 formation through time, likely via a type‐II photochemical mechanism. The degradation of DNA nucleotides (8‐hydroxy 2‐deoxyguanosine), the formation of superoxide anion radical (O2.‐) which was validated by significant O2.– quenching by superoxide dismutase (SOD), and peroxidation of membrane lipid (linoleic acid), increased significantly in sunlight exposures, however the presence of EP at 24 mg/L had no significant influence on this effect. Overall, sunlight quickly degraded EP in solution, however the sunlight‐irradiated EP caused no discernable toxic effects in cell‐free assays relative to sunlight alone.

Degradation of organic pollutants in the presence of new Mn (II) complexes under ambient light or darkness conditions

The Mn (II) complexes prepared from Schiff’s bases, like salophen type ligands, were complexed via N & O donors under the solvothermal method. These Mn (II) complexes were first validated through elemental data, which was confirmed by mass spectra. At the same time, several spectroscopic practices such as XPS, p-XRD, FT-IR, Raman, FESEM and thermal-stability of the Mn2+ complexes were examined from TGA. The bandgap energies and oxidation potentials of the Mn (II) complexes are assessed with UV–visible DRS and CV investigations. Emission spectra clearly stated that the rate of recombination electron and hole pair is lower for the M−2 complex as compared to the M−1complex. The prepared Mn (II) complexes were used for the mineralization of cationic and anionic dyes such as rhodamine 6G (Rh6G λmax. = 553 nm), and congo red (CR λmax. = 498 nm) under dark ambient conditions. The M−2 complex is more active than M−1 due to its low bandgap energy, low rate of recombination hole-electron pair, and insitu formation of superoxide radicals during catalytic dark ambient mineralization. Active species are identified by ESR studies, which are supported by scavenger data, and then the mechanism of the rapid mineralization of organic dye contaminants is established.

Fullerene C70 as Photoredox Catalyst for the Synthesis of Pyrrolo[2,1-a]isoquinolines by 1,3-Dipolar Cycloaddition-Aromatization Sequence.

Herein, fullerene (C70 ) is introduced as an effective photoredox catalyst for the construction of a highly functionalised pyrrolo[2,1-a]isoquinoline framework by 1,3-dipolar cycloaddition-aromatisation reaction sequence. The ability of C70 to efficiently harvest visible light, its long-triplet state lifetime, good photostability, and strong singlet oxygen generation potential (Φ▵ ≈1), make it an efficient photoredox catalyst. Upon photoirradiation, C70 promotes the formation of singlet oxygen and superoxide radical by energy transfer (EnT) and single electron transfer (SET) mechanism. The superoxide radical acts as a potential oxidant in the formation of azomethine ylide through the oxidation-deprotonation tandem process. Azomethine ylide further participates in [3+2]-cycloaddition reaction protocol with alkene/alkyne to give the corresponding pyrrolo[2,1-a]isoquinolines. Interestingly, this protocol allows the activation of a wide range of substrates giving access to a diverse library of 48 well-decorated pyrrolo[2,1-a]isoquinolines with good functional group tolerance.

MP60-03 ORGANO-SELENIUM URINARY CATHETERS INHIBIT GROWTH AND BIOFILM FORMATION OF E. COLI , K. PNEUMONIAE , P. AERUGINOSA, AND H. INFLUENZAE IN-VITRO

You have accessJournal of UrologyCME1 Apr 2023MP60-03 ORGANO-SELENIUM URINARY CATHETERS INHIBIT GROWTH AND BIOFILM FORMATION OF E. COLI, K. PNEUMONIAE, P. AERUGINOSA, AND H. INFLUENZAE IN-VITRO Rachel Vopni, Unique Jacobo, Phat Tran, Shruti Patel, Suyash Jain, Cornelia De Riese, Ted Reid, and Werner De Riese Rachel VopniRachel Vopni More articles by this author , Unique JacoboUnique Jacobo More articles by this author , Phat TranPhat Tran More articles by this author , Shruti PatelShruti Patel More articles by this author , Suyash JainSuyash Jain More articles by this author , Cornelia De RieseCornelia De Riese More articles by this author , Ted ReidTed Reid More articles by this author , and Werner De RieseWerner De Riese More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003318.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Catheter-associated urinary tract infections (CAUTIs) are of significant medical burden in cost, morbidity, and mortality. Experimental selenium-coated medical devices have demonstrated nontoxic in-vitro and in-vivo antimicrobial activity due to the ability of selenium to catalyze formation of superoxide radicals. While antimicrobial-coated catheters have shown efficacy in preventing CAUTIs, selenium has not been tested in this context. The purpose of this in-vitro study is to evaluate selenium-incorporated urinary catheters for inhibition of uropathogenic bacterial growth and biofilm formation. METHODS: Urinary catheters incorporated with 1% organo-selenium and standard (uncoated) catheters were incubated in-vitro with E. coli, K. pneumoniae, P. aeruginosa, H. influenzae, and combinations of these bacteria. Growth was evaluated by colony forming unit count and visualized with confocal laser and scanning electron microscopy. Organo-selenium catheter material integrity was also tested by soaking the tubing in phosphate-buffered saline for 12-weeks at 37°C. RESULTS: Organo-selenium-incorporated catheters demonstrated total reduction (100%) of in-vitro bacterial growth and biofilm formation for E. coli, K. pneumoniae, H. influenzae, and a combination of these species when compared to control. P. aeruginosa growth was inhibited by approximately 4 logs (99.99%). Complete inhibition of E. coli growth was maintained after long-term phosphate-buffered saline soaking. CONCLUSIONS: The results demonstrate that organo-selenium was stably incorporated into catheter tubing and inhibited bacterial attachment, growth, and biofilm formation for multiple uropathogenic organisms. Furthermore, long-term soaking of organo-selenium tubing in phosphate-buffered saline did not show any decline in bacterial growth inhibition or biofilm formation. These findings suggest that organo-selenium-incorporated catheters may be advantageous in preventing CAUTIs and warrant further in-vivo and clinical evaluation. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e843 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Rachel Vopni More articles by this author Unique Jacobo More articles by this author Phat Tran More articles by this author Shruti Patel More articles by this author Suyash Jain More articles by this author Cornelia De Riese More articles by this author Ted Reid More articles by this author Werner De Riese More articles by this author Expand All Advertisement PDF downloadLoading ...

Radical Scavenging Is Not Involved in Thymoquinone-Induced Cell Protection in Neural Oxidative Stress Models.

Thymoquinone (TQ), an active compound from Nigella sativa seeds, is often described as a pharmacologically relevant compound with antioxidative properties, while the synthesis of TQ in the plant via oxidations makes it inapplicable for scavenging radicals. Therefore, the present study was designed to reassess the radical scavenging properties of TQ and explore a potential mode of action. The effects of TQ were studied in models with mitochondrial impairment and oxidative stress induced by rotenone in N18TG2 neuroblastoma cells and rotenone/MPP+ in primary mesencephalic cells. Tyrosine hydroxylase staining revealed that TQ significantly protected dopaminergic neurons and preserved their morphology under oxidative stress conditions. Quantification of the formation of superoxide radicals via electron paramagnetic resonance showed an initial increase in the level of superoxide radicals in the cell by TQ. Measurements in both cell culture systems revealed that the mitochondrial membrane potential was tendentially lowered, while ATP production was mostly unaffected. Additionally, the total ROS levels were unaltered. In mesencephalic cell culture under oxidative stress conditions, caspase-3 activity was decreased when TQ was administered. On the contrary, TQ itself tremendously increased the caspase-3 activity in the neuroblastoma cell line. Evaluation of the glutathione level revealed an increased level of total glutathione in both cell culture systems. Therefore, the enhanced resistance against oxidative stress in primary cell culture might be a consequence of a lowered caspase-3 activity combined with an increased pool of reduced glutathione. The described anti-cancer ability of TQ might be a result of the pro-apoptotic condition in neuroblastoma cells. Our study provides evidence that TQ has no direct scavenging effect on superoxide radicals.

Water Activation for Boosting Electrochemiluminescence

AbstractIn conventional luminol electrochemiluminescence (ECL) systems, hydrogen peroxide and dissolved oxygen are employed as typical co‐reactants to produce reactive oxygen species (ROS) for efficient ECL emission. However, the self‐decomposition of hydrogen peroxide and limited solubility of oxygen in water inevitably restrict the detection accuracy and luminous efficiency of luminol ECL system. Inspired by ROS‐mediated ECL mechanism, for the first time, we used cobalt‐iron layered double hydroxide as co‐reaction accelerator to efficiently activate water to generate ROS for enhancing luminol emission. Experimental investigations verify the formation of hydroxyl and superoxide radicals in the process of electrochemical water oxidation, which subsequently react with luminol anion radicals to trigger strong ECL signals. Finally, the detection of alkaline phosphatase has been successfully achieved with impressive sensitivity and reproducibility for practical sample analysis.

Water Activation for Boosting Electrochemiluminescence.

In conventional luminol electrochemiluminescence (ECL) systems, hydrogen peroxide and dissolved oxygen are employed as typical co-reactants to produce reactive oxygen species (ROS) for efficient ECL emission. However, the self-decomposition of hydrogen peroxide and limited solubility of oxygen in water inevitably restrict the detection accuracy and luminous efficiency of luminol ECL system. Inspired by ROS-mediated ECL mechanism, for the first time, we used cobalt-iron layered double hydroxide as co-reaction accelerator to efficiently activate water to generate ROS for enhancing luminol emission. Experimental investigations verify the formation of hydroxyl and superoxide radicals in the process of electrochemical water oxidation, which subsequently react with luminol anion radicals to trigger strong ECL signals. Finally, the detection of alkaline phosphatase has been successfully achieved with impressive sensitivity and reproducibility for practical sample analysis.

Physicochemical properties of green synthesised ZnO nanoparticles and utilisation for treatment of breast cancer

Metal oxide nanoparticles with unique properties have recently attracted much attention as a potential smart material for treatment of cancer. The inherent structural and ionic defects in ZnO nanoparticles allow the formation of intracellular superoxide and hydroxyl radicals after entering a cancer cell causing damage on DNA and preventing subsequent replication. However, the full extent of the DNA damage and the knock-on effect with respect to protein synthesis is not copiously comprehended. This study tries to tune the cytotoxic activity of ZnO nanoparticles in virtue of physicochemical property against human breast cancer cell (MCF-7) via reactive oxygen species (ROS) induced DNA damage leading to apoptosis. In order to produce an array of different size and shape of ZnO nanoparticles with varying structural defects, this study utilised the unique phytochemicals of Terminalia arjuna, Swertia chirayita, and Psidium guajava as the active reducing agents for the formation of the nanoparticle from the mineral salt. Variations in the created nanoparticle size and relative structural defects have caused a consequential surge in ROS production inside cancer cells resulting in enhanced effectiveness of ZnO nanoparticles for cancer treatment.

Unraveling reactive oxygen species-dependent toluene mineralization routes via construction of TixSn1−xO2 infinite solid solution photocatalysts

Intermediates seriously affect the reaction process and rate in terms of kinetics. However, there are few studies on the effect of reactive oxygen species on intermediates of toluene mineralization. Herein, SnO2 and TixSn1−xO2 infinite solid solution photocatalysts are prepared and the mineralization ability of Ti0.1Sn0.9O2 is 2.7 times that of SnO2. Introduction of Ti shifts the conduction band position upward, providing thermodynamic possibility for superoxide radicals formation. The sole hydroxyl radicals over SnO2 lead to the generation of benzyl alcohol; while synergetic hydroxyl radicals and superoxide radicals result in benzoic acid existed in solid solution catalysts. Theoretical calculation confirms that benzoic acid has lower ring opening barrier, thereby improving toluene mineralization ability over TixSn1−xO2. The synergetic roles of Ti and Sn in adsorption and activation of water and toluene moleculars are also proposed. This work provides new insights into reactive oxygen radicals regulation to alter intermediates and ease toluene removal.

Visible-light-driven direct decarboxylative carbonylation of carboxylic acids using acridine photocatalysis in oxygen-liquid flow

Photocatalytic direct decarboxylative carbonylation of ubiquitous carboxylic acids is a promising strategy to obtain highly versatile ketone building blocks, but metal-free and efficient conversions are still lacking. Here, density functional theory calculations are used to guide the experimental screening of catalysts, highlighting the potential influence of frontier molecular orbital energy levels on the catalytic process and revealing an acridine photocatalyst capable of realizing value-added conversion of carboxylic acid at room temperature under visible light with excellent performance. The possible mechanism for this conversion was elucidated in depth by combining study of the excited state behavior of the photosensitizer and the results of detection experiments for radicals. Theoretical calculations and mechanistic studies further disclose the kinetically rate-limiting role of oxygen, including its participation in the formation of superoxide radicals for carbonylation and as an electron trapping agent for catalyst cycling. Based on these findings, a flow microreactor platform was ingeniously built to achieve previously inaccessible photocatalytic decarboxylative carbonylation promoted by acridine in concert with oxygen. Interestingly, the gas–liquid segmented microflow is found to enable a significant acceleration (from 14 to 2 h) and higher yield compared to the batch counterpart, resulting in a high space–time yield of 137.4 g/L d-1 for this transformation, which far exceeds the reported values. This study underscores the feasibility of broadening the competence of acridine photocatalysis through the involvement of kinetically adapted oxygen, thus enabling substitution of metal-dependent photocatalysis and even more efficient and high-yield decarboxylative carbonylation of carboxylic acids.

Visible-light-driven benzyl alcohol oxidation over Pt/Mn-Bi4Ti3O12 nanosheets: Structure-function relationship of multicomponent photocatalysts

Herein, a series of Pt nanoparticles modificatory Mn doped Bi4Ti3O12 ultrathin nanosheets (Pt/MnNS) are constructed as a surface functionalized photocatalyst for the visible-light-driven selective benzyl alcohol (BA) oxidation. Especially, Pt/5MnNS shows the best performance with a benzaldehyde (BD) yield rate of 1180 μmol·g−1·h−1 and a selectivity of 99.9 %. More importantly, experimental results reveal that Mn doping not only extends the optical absorption range of the photocatalyst to the visible region, but also induces the formation of more surface Ti4+δ atoms. Those Ti4+δ atoms as stronger Lewis acid centers achieve more conspicuous adsorption and activation of BA via the CO⋯Ti coordination. It makes the deprotonation of BA by photogenerated holes be easier. Meanwhile, Pt nanoparticles significantly promote the separation and transfer of the photogenerated carriers for supporting the formation of superoxide and carbon-centered radicals. Thus, the photocatalytic BA oxidation efficiency is markedly improved by surface multicomponent synergistic effect.

Boosting photocatalytic oxidation of organic pollutants on Z-scheme carbon nitride / Ag3PO4 / Ag composites by coupling with carbon nanotubes

ABSTRACT The present study reports the development of ternary and quaternary carbon nitride (CN) based nanocomposites through the coupling of CN with single-walled carbon nanotubes (SWCNTs), Ag3PO4 (AP) and Ag nanoparticles (NP). A facile wet-chemistry process was developed for the synthesis of the composites. The prepared materials were characterised using XRD, ATR, DR-UV-Vis, photoluminescence (PL) spectroscopy and EPR. Photocatalytic dye degradation (rhodamine b, RhB) is greatly improved in composite materials. The most active photocatalyst was the quaternary composite bearing SWCNTs, Ag3PO4 and Ag NP, that presented a 2- and a 3-fold increase in photoactivity compared with the CN functionalised only with SWCNTs and the pure CN, respectively. The enhanced activity is associated with improvements in several important materials properties. Adsorption in the visible light is improved by the presence of Ag3PO4 and Ag NP. The latter provided plasmon resonance effects, absorbing light up to 700 nm. The presence of SWCNTs reduced charge recombination phenomena reducing by half the PL intensity. In addition, charge availability was further increased due to the formation of heterojunctions through the coupling of CN with Ag3PO4 and Ag NP. The PL intensity of the ternary composite was reduced to 1% of the pure CN PL intensity. In-situ EPR spectroscopy using spin-traps revealed the formation of superoxide anion radicals ( O 2 ∙ − ) that provide evidence for charge transfer via a Z-scheme mechanism. O 2 ∙ − production was enhanced 8.5 times in the ternary composite compared with the pure CN. The importance of the stepwise functionalization of CN through the formation of ternary and quaternary composites towards the development of advanced photoactive materials is highlighted herein.

Decoration of ZnO surface with tiny sulfide-based nanoparticles for improve photocatalytic degradation efficiency

Modifying wide band gap ZnO nanoparticles surface by combine narrow bandgap semiconductors is a novel route to promote the ZnO to diverse applications. Herein, different metal sulfides (CdS, Ag2S and Bi2S3) were decorated on ZnO surface using facile a chemical route for photocatalytic application. Crystal structure, surface morphology and optical changes for the surface modified ZnO were studied by using various characterization techniques. The XRD spectra exhibited mixed phase of decorated metal sulfide nanoparticles along with strong pattens of hexagonal structure ZnO. The SEM images were confirmed that tiny CdS, Ag2S and Bi2S3 sulfide nanoparticles are well decorated on ZnO hexagonal rods surface. Band gap of the ZnO was tuned into visible region by modifying the surface by the sulfide nanoparticles. Textile industry-based crystal violet (CV) dye was used as a model pollutant to evaluate the photocatalytic activity of sulfides decorated well-crystalline ZnO photocatalysts under natural sunlight. Among the three catalysts, the Ag2S decorated ZnO achieved greatest photodegradation efficiency of 94.1% for degradation of the CV dye with rate constant value of 0.050. The highest catalytic activity may be related to Ag2S acting a significant part in reducing bandgap and boosting hole, superoxide radical, and hydroxyl radical formation, which inhibits recombination, hence enhancing the photocatalyst's efficacy, activity, and also stability.

Highly porous BiOBr@NU-1000 Z-scheme heterojunctions for synergistic efficient adsorption and photocatalytic degradation of tetracycline.

Designing an effective photoactive heterojunction having dual benefits towards photoenergy conversion and pollutant adsorption is regarded as an affordable, green method for eliminating tetracycline (TC) from wastewater. In this regard, a series of BiOBr@NU-1000 (BNU-X, X = 1, 2 and 3) heterojunction photocatalysts are constructed. BNU-X preserves the original skeleton structure of the parent NU-1000, and its high porosity and specific surface area enable superior TC adsorption. At the same time, BNU-X is an effective Z-scheme photocatalyst that improves light trapping, promotes photoelectron-hole separation, and shows excellent photocatalytic degradation efficiency towards TC with the value of the photodegradation kinetic rate constant k being 2.2 and 24.8 times those of NU-1000 and BiOBr, respectively. The significant increase in the photocatalytic activity is ascribed to the construction of an efficient Z-scheme photocatalyst, which promotes the formation of superoxide radicals (˙O2-) and singlet oxygen (1O2) as the main oxidative species in the oxidation system. This research has the advantage of possibilities for the development of porous Z-scheme photocatalysts based on photoactive MOF materials and inorganic semiconductors for the self-purification and photodegradation of organic contaminants.

Magnetic chitosan/TiO2 composite for vanadium(v) adsorption simultaneously being transformed to an enhanced natural photocatalyst for the degradation of rhodamine B.

A magnetic chitosan/TiO2 composite material (MCT) was developed. MCT was successfully synthesized by a one-pot method using chitosan, TiO2, and Fe3O4. The absorption equilibrium time of MCT was 40 min in absorbing vanadium(v), the optimal adsorption pH was 4, and the maximum adsorption capacity of vanadium(v) was 117.1 mg g-1. The spent MCT was applied to photocatalytic reactions for reutilization. The decolorization rates for the degradation of rhodamine B (RhB) by new and spent MCT were 86.4% and 94.3%, respectively. The new and spent MCT exhibited absorption bands at 397 and 455 nm, respectively, which showed that the spent MCT was red-shifted to the cyan light region. These results indicated that the forbidden band widths of the new and spent MCT were about 3.12 and 2.72 eV, respectively. The mechanism of the degradation reaction showed that the hydroxyl radicals as oxidants in the spent MCT mediated the photocatalytic degradation of RhB. In addition, the superoxide anion radical formation of hydroxyl radicals was the main reaction, and the hole generation of hydroxyl radicals was the subordinate reaction. The N-de-ethylated intermediates and organic acids were monitored by MS and HPLC.

HPB O05 Identifying pathways involved in post-hepatectomy liver failure

Abstract Background The liver is the only visceral organ with regenerative capabilities. This ensures maintenance of the liver-to-bodyweight ratio required for homeostasis. Failure of this mechanism can be fatal. Precipitants to liver failure include infection, drug toxicity and surgical resection. Post-hepatectomy liver failure (PHLF) is associated with small for size syndrome i.e., insufficient post hepatectomy liver volume. The mechanisms by which liver failure occurs on a molecular basis are not yet fully understood, but theories include uncontrolled apoptosis from unrivalled superoxide radical formation causing irreparable oxidative stress. A major research focus of liver regeneration has been modulating the anti-oxidative response to any form of liver injury, but identifying pathways involved in dysfunctional liver regeneration after surgery have yet to be elucidated. Nuclear factor erythoid 2-related factor 2 (Nrf2) is an anti-oxidant transcription factor which promotes liver regeneration. Using a murine partial hepatectomy model, we have shown that pharmacological stimulation of Nrf2 increases the rate of post hepatectomy liver regeneration. Furthermore glutathione (GSH – a downstream target of Nrf2), has been linked with impaired liver regeneration when deficient. In this study, we present data on GSH analysis in liver tissue taken from patients undergoing hepatectomy. Methods Liver parenchyma was collected ex-vivo from patients undergoing liver resection (National Research Ethics Service approval 11/NW/0327). Additionally, isolated RNA from hepatic parenchyma from patients undergoing liver resections was received from collaborators at the Medical University of Vienna, Austria. From liver tissue, protein was isolated using a standard protocol and immunoblotting performed; RNA was isolated using a Monarch RNA preparation kit (NEB, UK), and quantitative PCR was performed. GSH levels in liver tissue were analysed using a standard enzyme recycling method. Relevant targets were identified based on their response to anti-oxidative stress as defined in literature. Primers were designed based on internally validated sequences and antibodies were purchased externally. qPCR was performed using the fluorescent dye, SYBR Green with a ViiA 7 Real-Time PCR system (ThermoFisher). Immunoblotting consisted of transferring separated by weight proteins onto a membrane which was then blocked in 5% milk, with primary and then secondary antibody incubation. Chemiluminescence was applied and bands were visualised using a ChemiDoc (BioRad). Bands were quantified using ImageJ software, and expressed in relation to actin. PHLF was classified according to the ISGLS criteria. Control patients (with no PHLF) were matched for demographic and clinico-pathologic variables (major resection as per the Brisbane criteria). Results Protein expression and GSH expression was measured in liver tissue from 23 patients. Of these, 10 had no PHLF, 4, 3 and 6 were classified as having Grades A, B, and C PHLF respectively. Additional isolated RNA samples yielded 11 with no PHLF, and 14 PHLF (4, 7 and 3, grade A, grade B and grade C, respectively) patients. A GSH assay showed no change in expression between those without PHLF and those with grade A and grade B, but patients who had grade C PHLF had significantly lower levels of GSH (p=0.0040). With respect to gene expression, GCLC, encoding the enzyme glutamate cysteine ligase catalytic subunit, the first rate limiting enzyme of glutathione synthesis, was also significantly lower in patients with grade C compared to those without PHLF of grade A/B (p=0.0206). Protein expression showed significantly reduced levels of GCLC when comparing grade C with patients without PHLF. Furthermore, samples taken at 2 timepoints (pre-parenchymal transection, and then 2 hours later from the resection margin) have shown a decrease in GCLC gene expression in patients who have grade C PHLF. Conclusions Our results have shown that patients who have grade C PHLF (who all died from acute liver failure post-operatively), have significantly lower levels of GSH in liver tissue taken at the time of resection. There is already a weight of evidence showing activation of the transcription factor Nrf2 (encoding GSH) enhances liver regeneration, however this is not without off target effects. Although not known to promote oncogenesis, in vitro studies have shown that persistent overstimulation of Nrf2 promotes cancer cell growth and proliferation, in part by improving the chemoresistance of cancer cells. This effect is theorised to be due to metabolic reprogramming of cancer cells, resulting in elevated levels of metabolic enzymes involved in cell proliferation.Whilst it is appreciated that liver failure is multi-factorial, targeting genes that promote liver regeneration may reduce the risk of failure. Identifying and targeting individual genes which are involved in liver regeneration may help to overcome potentially deleterious off target effects. This data suggests that GSH is a potential therapeutic target reducing the risk of PHLF.

Multi-dimensional (2D–3D) assembly of BiOI/BiOBr/UiO-66-NH2 composites to form multi-heterojunction structures for synergistic removal of Rhodamine B

In order to enhance the role of UiO-66-NH2 in the photocatalytic system, the method of loading Bi-based materials to construct heterojunctions was chosen to enhance its photocatalytic ability. In this study, the ternary composite BiOI/BiOBr/UiO-66-NH2 was successfully synthesized, and a double type Ⅱ heterojunction was formed among the three. The successful synthesis and the closely interaction of the composites were proved by a series of characterization. Under simulated visible light, the composite material (UBB3) with a molar ratio of KBr to KI of 1:3 had the best RhB removal performance. The removal rate of Rhodamine B (RhB) can be as high as 99.16 % after 80 min of visible light irradiation. This study also preliminarily explored the direct, efficient and rapid degradation of RhB under visible light without dark adsorption stage. The composite material also had good reusability. The enhancement of visible light utilization and the inhibition of electron(e-)-hole(h+) recombination were the main reasons for the enhancement of photocatalytic activity. In the presence of double heterojunctions, it was found that while the formation of superoxide radicals was involved in the degradation of pollutants, h+ were directly involved in the degradation of RhB as reactants, reducing the reaction procedure. Finally, the photocatalytic mechanism was proposed.

ZIF-8 derived porous C, N co-doped ZnO modified B-g-C3N4: A Z-Scheme charge dynamics approach operative towards photocatalytic hydrogen evolution and ciprofloxacin degradation

Herein, the fabrication of a robust CNZ/BCN nanocomposite is achieved by a facile in-situ calcination of ZIF-8 along with BCN precursors. Morphologically the dodecahedral ZIF-8 farmeworks are transformed into granular CNZ nanoparticles that were densely adhered to the BCN nanosheet surface with interfacial interactions. MOF derived strategy plays significant role in reducing the optical band gap via introducing C, N into the ZnO lattice as known from UV–vis-DRS as well as XPS studies. Additionally the composite formation lead to significantly enhanced exciton anti-recombination as suggested from EIS and PL analysis. The optimal CNZ/BCN (1:1) nanohybrid exhibits enhanced photocatalytic H2 evolution rate of 7020 µmol h−1 g−1 which is nearly-two and eight folds greater than that of pristine CNZ and BCN respectively along with maximal ciprofloxacin photo-degradation rate (86.7 %). The radical trapping experiments deduced the formation of both superoxide and hydroxyl radicals that promotes the nanocomposite to follow Z-scheme charge transfer pathway during photocatalysis. Intermediates formed during CIP photo-degradation were identified by using LC-MS technique that showed ten intermediates formed through two different routes. Hence, MOF derived CNZ and BCN nanocomposite acts as a robust Z-scheme mediated photocatlyst that can be employed for varied energy and environmental purposes.

Зміна окремих показників еритроцитів крові щурів за впливу гістаміну і кверцетину

Зміна окремих показників еритроцитів крові щурів за впливу гістаміну і кверцетину

The efficacy of organo-selenium conjugated cellulose polymer dressing to inhibit Candida albicans biofilm formation

Selenium covalently bonded to cellulose can catalyze the formation of superoxide radicals. Candida albicans, colonizes epithelial surfaces and can be a fatal infection in immunocompromised people. In this study, we demonstrated the ability of organo-selenium, covalently attached to cotton textile dressings to kill C. albicans biofilms.