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Methods in Enzymology 2024Vanadium-dependent haloperoxidases (VHPOs) are a unique family of enzymes that utilize vanadate, an aqueous halide ion, and hydrogen peroxide to produce an electrophilic...
Vanadium-dependent haloperoxidases (VHPOs) are a unique family of enzymes that utilize vanadate, an aqueous halide ion, and hydrogen peroxide to produce an electrophilic halogen species that can be incorporated into electron rich organic substrates. This halogen species can react with terpene substrates and trigger halonium-induced cyclization in a manner reminiscent of class II terpene synthases. While not all VHPOs act in this capacity, several notable examples from algal and actinobacterial species have been characterized to catalyze regio- and enantioselective reactions on terpene and meroterpenoid substrates, resulting in complex halogenated cyclic terpenes through the action of single enzyme. In this article, we describe the expression, purification, and chemical assays of NapH4, a difficult to express characterized VHPO that catalyzes the chloronium-induced cyclization of its meroterpenoid substrate.
Topics: Alkyl and Aryl Transferases; Terpenes; Cyclization; Vanadium; Substrate Specificity; Peroxidases; Enzyme Assays
PubMed: 38942514
DOI: 10.1016/bs.mie.2024.03.024 -
Journal of Environmental Management Jun 2024Volcanic eruption is associated with the release of large volumes of pollutants in the environment, which can pose a risk to humans and other living organisms. The...
Volcanic eruption is associated with the release of large volumes of pollutants in the environment, which can pose a risk to humans and other living organisms. The elemental and radioisotope composition of ash released during the Shiveluch Volcano eruption in 2023 was analyzed using ICP-MS and low-background gamma spectrometry. The ash consisted of 59% SiO, 16.7% AlO, 5.3% CaO, 4.6 % NaO, 4.5% FeO, 1.4% KO, 0.48% TiO, 0.17% PO, 0.15% S, 0.078% MnO and 44 trace elements. Hazard Quotient and Hazard Index were calculated in order to evaluate the potential health risks to children and adults due to exposure to contaminants via inhalation, ingestion, and dermal contact. All values were below the unit, indicating a low probability of non-carcinogenic and cancerogenic risk occurrence in target groups. The average activity concentrations of the natural radionuclides were 350, 12.4 and 4.84 Bq/kg for K, Ra and Th. Radiological indices, including external and internal risk assessment, radium equivalent activity, annual effective dose, gamma index, and excess lifetime cancer risk were calculated to estimate the radiological hazard for the population. The values of all indices were below the recommended safety limits, indicating a low level of hazard for the exposed population.
PubMed: 38941854
DOI: 10.1016/j.jenvman.2024.121616 -
Journal of Hazardous Materials Jun 2024Cadmium (Cd) accumulation in rice, a global environmental issue, poses a significant threat to human health due to its widespread presence and potential transfer through... (Review)
Review
Cadmium (Cd) accumulation in rice, a global environmental issue, poses a significant threat to human health due to its widespread presence and potential transfer through the food chain. Selenium (Se), an essential micronutrient for humans and plants, can reduce Cd uptake in rice and alleviate Cd-induced toxicity. However, the effects and mechanisms of Se supplementation on rice performance in Cd-contaminated soil remain largely unknown. Here, a global meta-analysis was conducted to evaluate the existing knowledge on the effects and mechanisms by which Se supplementation impacts rice growth and Cd accumulation. The result showed that Se supplementation has a significant positive impact on rice growth in Cd-contaminated soil. Specifically, Se supplementation decreased Cd accumulation in rice roots by 16.3 % (11.8-20.6 %), shoots by 24.6 % (19.9-29.1 %), and grain by 37.3 % (33.4-40.9 %), respectively. The grain Cd reduction was associated with Se dose and soil Cd contamination level but not Se type or application method. Se influences Cd accumulation in rice by regulating the expression of Cd transporter genes (OSLCT1, OSHMA2, and OSHMA3), enhancing Cd sequestration in the cell walls, and reducing Cd bioavailability in the soil. Importantly, Se treatment promoted Se enrichment in rice and alleviated oxidative damage associated with Cd exposure by stimulating photosynthesis and activating antioxidant enzymes. Overall, Se treatment mitigated the health hazard associated with Cd in rice grains, particularly in lightly contaminated soil. These findings reveal that Se supplementation is a promising strategy for simultaneous Cd reduction and Se enrichment in rice.
PubMed: 38941835
DOI: 10.1016/j.jhazmat.2024.135043 -
Environmental Monitoring and Assessment Jun 2024Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the...
Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the performance of simultaneous degradation of the mixed pollutants (amoxicillin, acetaminophen, and ciprofloxacin) for an aqueous solution using the solar Fenton process. Operating parameters such as pH, iron doses, HO doses, pollutant concentrations, and time were studied. From the experimental results, the ideal conditions were obtained for the removal of mixed pollutants such as pH 3, Fe 0.04 mM, HO 4 mM, the concentration of the mixed pollutants 5 mg/L, solar radiation 400 W/m, and time 10 min, respectively. The pseudo-first-order kinetics were utilized to investigate the degradation efficacy of the mixed pollutants. The result of the study indicates that the degradation efficiency was > 99% for the mixed pollutants. A maximum of 63% mineralization was observed, and hydroxyl radical scavenger effects were studied. The best optimal conditions were applied to assess the spiked wastewater (municipal wastewater (MWW) and hospital wastewater (HWW)). The highest elimination rates for AMX, ACET, and CIP were observed as 65%, 89%, and 85% for MWW and 76%, 92%, and 80% for HWW, respectively. The degraded by-products were detected by LC-ESI-MS in the water matrix (aqueous solution and spiked wastewater), and ECOSAR analysis was performed for the transformed products. The study concluded that the solar Fenton technique is promising and effective for the removal of mixed pollutants from the water matrix.
Topics: Water Pollutants, Chemical; Hydrogen Peroxide; Kinetics; Iron; Waste Disposal, Fluid; Sunlight; Wastewater; Oxidation-Reduction; Ciprofloxacin; Acetaminophen; Amoxicillin
PubMed: 38942963
DOI: 10.1007/s10661-024-12837-2 -
Scientific Reports Jun 2024The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the...
The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the pyrolysis of termite-processed biomass, specifically Pinus elliottii particleboard and its termite droppings (TDs), to produce biochar and its application for chromium (VI) adsorption. Termite droppings, rich in lignin, and particleboard, rich in cellulose, were pyrolyzed at various temperatures to assess the effect of biomass composition on biochar properties. The study found that lignin-rich termite droppings produced biochar with higher fixed carbon content and specific surface area than cellulose-rich particleboard biochar. FTIR and Raman spectroscopy revealed significant molecular structure changes during pyrolysis, which influenced the adsorption capabilities of the biochar. Adsorption experiments demonstrated that TD biochar exhibited significantly higher chromium (VI) adsorption capacity, attributed to its distinct chemical composition and enhanced surface properties due to higher lignin content. These findings underscore the crucial role of lignin in producing efficient biochar for heavy metal adsorption, highlighting the practical applicability of termite-processed biomass in water purification technologies.
Topics: Charcoal; Lignin; Chromium; Animals; Cellulose; Biomass; Adsorption; Isoptera; Water Pollutants, Chemical; Pyrolysis; Pinus; Water Purification; Spectroscopy, Fourier Transform Infrared
PubMed: 38942919
DOI: 10.1038/s41598-024-65959-5 -
Current Sports Medicine Reports Jul 2024
Review
Topics: Humans; Ferritins; Athletes; Anemia, Iron-Deficiency; Iron
PubMed: 38941544
DOI: 10.1249/JSR.0000000000001178 -
Biological Trace Element Research Jun 2024Trace element bioaccumulation in marine organisms is a rising international issue due to possible health concerns for humans. Thirteen trace elements were analyzed in...
Trace element bioaccumulation in marine organisms is a rising international issue due to possible health concerns for humans. Thirteen trace elements were analyzed in the sediment, water, and muscular tissue of Red Sea fish. Additionally, the average daily intake (EDI), the cancer risk (CR), the hazard index (HI), and the target hazard quotient (THQ) of those elements have been taken into consideration when evaluating any possible health concerns related to their consumption. All species presented quantifiable values in muscle for all the analyzed elements (arsenic (As), lead (Pb), copper (Cu), aluminum (Al), boron (B), iron (Fe), barium (Ba), manganese (Mn), nickel (Ni), cadmium (Cd), chromium (Cr), zinc (Zn), and mercury (Hg), except for Cd and Hg, being Fe and Zn the most accumulated elements in all species. Conversely, in water samples, most elements were undeleted except for aluminum, boron, iron, and zinc. All Red Sea fish, however, had concentrations of Zn, Ni, Fe, Cu, and Mn below the upper limit allowed, although most species had higher levels of As, Cr, and Pb (0.48 ± 0.83-5.10 ± 0.79, 1.97 ± 0.46-5.25 ± 0.67 and 2.12 ± 1.01-6.83 ± 0.93 µg/g, respectively).The studied Red Sea fish showed contamination degrees (CD) of Mn, Cu, Fe, Ni, Zn, and Pb were ≤ 1, indicating minimal contamination, with As and Cr showing higher contamination degrees. However, the pollution index values (MPI-elements) can be represented according to ascending order: Lethrinus ramak < Cephalopholis hemistiktos < Pagellus affinis < Trachurus japonicus < Cheilinus lunulatus < Siganus luridus < Parupeneus forsskali < Caesio suevica. The study found that edible tissues are safe for human consumption, with HI values for children and adults less than ten, indicating negligible non-cancer hazards. However, fish consumption presents health risks due to chromium, lead, and arsenic, with THQ values several times greater than 1, and CR-Ni, CR-Cr, and CR-As values exceeding the acceptable 10 value in all studied species. This study provides critical insights into trace element contamination in marine fish species, highlighting the need for ongoing monitoring and proactive measures to ensure safe marine fish consumption in the Aqaba Gulf.
PubMed: 38941061
DOI: 10.1007/s12011-024-04246-w -
Environmental Geochemistry and Health Jun 2024Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting...
Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting effectiveness of coating agents on the oxidation of iron sulfide minerals was investigated using pyrite and rock samples resulting from acid drainage. The film formed with both surface-coating agents was identified by pyrite surface analysis. It was also confirmed that the formation of coatings varies depending on the crystallographic orientation. The inhibitory effects under rainy and submerged conditions were investigated using column experiments. Submerged conditions accelerated deterioration compared to that under rainy conditions. Iron phosphate coating had a significantly better oxidation-inhibitory effect (84.86-98.70%) than iron silicate coating (56.80-92.36%), and at a concentration of 300 mM, H elution was inhibited by more than 90% throughout the experiment. Furthermore, methods for effective film formation were investigated in terms of producing Fe; (1) application of coating agents mixed with oxidant (HO), (2) application of coating agent after the use of the oxidant. In a rainy environment, applying iron phosphate-based coating using the sequential method showed oxidation inhibition effects for cycles 1-9, whereas applying the mixed material showed effects for cycles 9-13. The use of a surface-coating agent after applying an oxidant did not inhibit oxidation. The surface coating agent and the oxidizing agent should be applied as a mixture to form a film.
Topics: Silicates; Iron; Phosphates; Oxidation-Reduction; Acid Rain; Sulfides; Hydrogen Peroxide; Ferric Compounds
PubMed: 38941030
DOI: 10.1007/s10653-024-01996-3 -
Clinical and Experimental Medicine Jun 2024Both atezolizumab (a PD-L1 inhibitor) plus bevacizumab (A+B) and sintilimab (a PD-1 inhibitor) plus bevacizumab (S+B) are recommended as the first-line regimen for... (Comparative Study)
Comparative Study
Both atezolizumab (a PD-L1 inhibitor) plus bevacizumab (A+B) and sintilimab (a PD-1 inhibitor) plus bevacizumab (S+B) are recommended as the first-line regimen for advanced hepatocellular carcinoma (HCC) in China. Different efficacy between the two regimens combined with transvascular intervention for unresectable HCC (uHCC) remain unknown. We retrospectively analyzed uHCC patients treated in three centers by simultaneous combination of A+B or S+B with transarterial chemoembolization (TACE) and FOLFOX-based hepatic arterial infusion chemotherapy (HAIC). Objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and treatment-related adverse events (TRAEs) were compared. Totally 188 patients were included, with 92 and 96 administered A+B+TACE-HAIC (ABTH) and S+B+TACE-HAIC (SBTH), respectively. ORRs (62.0 vs. 70.8%, respectively; P = 0.257) and disease control rates (88.0 vs. 93.8%, P = 0.267) were similar between groups by the mRECIST criteria. ABTH showed no survival advantage over SBTH, with median PFS times of 11.7 months and 13.0 months, respectively (HR = 0.81, 95% CI, 0.52-1.26, P = 0.35) and similar OS times (HR = 1.19, 95% CI, 0.32-4.39, P = 0.8). No significant differences were observed in grade 3-4 TRAEs between groups. Either PD-L1 or PD-1 inhibitor plus bevacizumab combined with TACE-HAIC have similarly excellent therapeutic efficacy with manageable adverse events, representing promising treatment options for uHCC.
Topics: Humans; Carcinoma, Hepatocellular; Male; Bevacizumab; Middle Aged; Female; Liver Neoplasms; Retrospective Studies; Aged; Antineoplastic Combined Chemotherapy Protocols; Adult; Antibodies, Monoclonal, Humanized; Treatment Outcome; Immune Checkpoint Inhibitors; China; Chemoembolization, Therapeutic; Programmed Cell Death 1 Receptor; B7-H1 Antigen; Fluorouracil; Leucovorin
PubMed: 38940944
DOI: 10.1007/s10238-024-01415-y -
Clinical Cardiology Jul 2024Chronic heart failure (CHF) has always posed a significant threat to human survival and health. The efficacy of thiamine supplementation in CHF patients remains... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chronic heart failure (CHF) has always posed a significant threat to human survival and health. The efficacy of thiamine supplementation in CHF patients remains uncertain.
HYPOTHESIS
Receiving supplementary thiamine may not confer benefits to patients with CHF.
METHODS
A comprehensive search was conducted across the Cochrane Library, PubMed, EMBASE, ClinicalTrials.gov, and Web of Science databases up until May 2023 to identify articles investigating the effects of thiamine supplementation in CHF patients. Predefined criteria were utilized for selecting data on study characteristics and results.
RESULTS
Seven randomized, double-blind, controlled trials (five parallel trials and two crossover trials) involving a total of 274 patients were enrolled. The results of the meta-analysis pooling these studies did not reveal any significant effect of thiamine treatment compared with placebo on left ventricular ejection fraction (WMD = 1.653%, 95% CI: -1.098 to 4.405, p = 0.239, I = 61.8%), left ventricular end-diastolic volume (WMD = -6.831 mL, 95% CI: -26.367 to 12.704, p = 0.493, I = 0.0%), 6-min walking test (WMD = 16.526 m, 95% CI: -36.582 to 69.634, p = 0.542, I = 66.3%), N-terminal pro-B type natriuretic peptide (WMD = 258.150 pg/mL, 95% CI: -236.406 to 752.707, p = 0.306, I = 21.6%), or New York Heart Association class (WMD = -0.223, 95% CI: -0.781 to 0.335, p = 0.434, I = 87.1%). However, it effectively improved the status of thiamine deficiency (TD).
CONCLUSIONS
Our meta-analysis indicates that thiamine supplementation does not have a direct therapeutic effect on CHF, except for correcting TD.
Topics: Humans; Heart Failure; Thiamine; Randomized Controlled Trials as Topic; Dietary Supplements; Chronic Disease; Ventricular Function, Left; Stroke Volume; Vitamin B Complex; Treatment Outcome
PubMed: 38940395
DOI: 10.1002/clc.24309