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Gas chromatography-mass spectrometry (GC-MS) has been applied to the analysis of arsenic forms in water, plants, and other samples; however, it has not been used to determine the form of arsenic in soil due to the complex soil matrix. The purpose of this study was to develop an analytical method for the simultaneous determination of inorganic arsenic species (As (III) and As (V)) and monomethylarsonic acid (MMA) in soil using GC-MS. The arsenic compounds were subjected to derivatization with 2,3-dimercapto-1-propanol (BAL) and subsequently analyzed using GC-MS. The BAL volume, derivatization reaction time, and temperature were optimized using standard added soil extracts. A reaction with 150 μL of BAL at 40°C for 30 min was selected as the optimal condition for quantitative derivatization of both inorganic arsenic (iAs) and MMA. The calibration curves exhibited linearity within the range of 5–100 ng/mL for each arsenic species, with correlation coefficients exceeding 0.997. The limits of detection for each arsenic species were determined to be 0.24 ng/mL and 1.31 ng/mL, respectively. The accuracy of the method was verified by the recovery of reference samples. The recovery experiments for reference samples showed that the recovery rates for As (III), As (V), and MMA were 89.5–93.7%, 88.5–105.6%, and 90.2–95.8% respectively, with precision ranging from 4.6 to 6.5%, 2.3 to 3.8%, and 2.4 to 6.3%. These results indicate good accuracy and precision. The accuracy of this method is not significantly different from that of liquid chromatography-inductively coupled plasma mass spectrometry (p = 0.05). The optimized method was sensitive, convenient and reliable for the extraction and analysis of different arsenic species in soil samples. [ABSTRACT FROM AUTHOR]

People are paying more and more attention to the effects of environmental factors such as heavy metals on depression, and heavy metals may destroy the homeostasis of vitamin D in the body by affecting human metabolism, and the lack of vitamin D will increase the risk of depression. There are few studies on vitamin D deficiency in depression caused by heavy metals, and it is not deep enough. Therefore, this study used logistic regression, restricted cubic spline curve, weighted quantile and Quantile g-computation model to analyze the effects of heavy metal exposure alone and in combination on vitamin D and depression, as well as the potential role of vitamin D deficiency in the process of heavy metal-induced depression. The results showed that cadmium exposure alone or in combination increased the risk of depression (P < 0.05). When Cd increased by 1 unit, the risk of depressive symptoms increased by 1.178 units. Arsenic and its compounds and lead affected vitamin D levels in the body and contributed the second highest or highest weight in the mixture (P < 0.05). It is worth noting that after grouping according to vitamin D deficiency, compared with the normal group, the mixed exposure of heavy metals in the vitamin D deficiency group had more types of metals related to depression and contributed more weight (P < 0.05). This study found that single metal or multi-metal mixed exposure is associated with depression. Vitamin D deficiency may increase the risk of depression. Vitamin D may be a potential factor in the treatment of depression caused by metal, and the specific mechanism of action needs further study. • The study evaluated the correlation between single metal and its mixture exposure and depression and vitamin D deficiency. • Multiple models were used to analyze the correlation between metal exposure and depression and vitamin D deficiency. • Vitamin D deficiency may aggravate depression caused by metal exposure. [ABSTRACT FROM AUTHOR]

Arsenic trioxide (ATO) has been shown to inhibit pancreatic cancer (PC) cell growth in vitro and to promote the inhibitory effects of gemcitabine (Gem) on PC in vivo. However, the high toxicity of ATO associated with the required high doses and indiscriminate targeting has limited its clinical application. This study aimed to determine whether coupling arsenic to a tumor homing peptide would increase the inhibitory potency against PC cells. The effects of this peptide-linked arsenic compound (PhAs-LHP), the analogous non-targeting arsenic compound (phenylarsine oxide, PAO), and marketed ATO on PC growth were tested in vitro and in a mouse model. The data demonstrated that PhAs-LHP inhibited PC cell growth in vitro more potently, with IC50 values 10 times lower than ATO. Like ATO, PhAs-LHP induced cell death and cell cycle arrest. This cytotoxic effect of PhAs-LHP was mediated via a macropinocytosis-linked uptake pathway as amiloride (a macropinocytosis inhibitor) reduced the inhibitory effect of PhAs-LHP. More importantly, PhAs-LHP inhibited PC growth in mice and enhanced the inhibitory effect of Gem on PC growth at 2 times lower molar concentration than PAO. These results indicate that PhAs-LHP inhibited PC more potently than ATO/PAO and suggest a potential clinical use for the combination of Gem with the peptide-linked arsenic compound for the treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]

The mobility of arsenic compounds in the soil-plant system and its interaction with biogenic macroelements K, P, Ca, Mg, Si, S, Na in plants under conditions of toxic stress have been studied. This is illustrated by the wheatgrass Elytrigia repens. It has been established that the root system is responsible for protecting the aerial part of wheatgrass from excess arsenic, and it is of great importance for phytostabilisation of arsenic pollution therefore indicating the increased tolerance of this plant. The intensity of As accumulation in plants depends on its speciation in the soil. Antagonism of the main essential elements (K, P) to the accumulation of As in wheatgrass shoots is observed. It can lead to disruption of metabolic processes in plant cells. It has been shown that changes in the K+/Na + values may lead to violation of osmotic processes in the aerial plant organs and contribute to their degradation not only under salt stress but also under the influence of higher concentrations of As in the plants. In areas intensively contaminated with arsenic, a decrease in the K/Na value in the above-ground organs of wheatgrass can be used as a criterion for the degree of phytotoxicity. [ABSTRACT FROM AUTHOR]

Simple Summary: Relapses of acute promyelocytic leukemia (APL) remain a challenge despite the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Given the variability in salvage therapies and emerging evidence supporting the deferral of hematopoietic cell transplantation (HCT) in patients receiving ATO, we analyzed the outcomes of a multicentric cohort of 67 relapsed APL patients. Better outcomes were reported with ATO ± ATRA compared to chemo-based regimens and ATRA ± Gemtuzumab ozogamicin (GO). A significant survival advantage was observed for patients undergoing HCT in the chemo-based cohort (p = 0.017), but not in the ATO-based group (p = 0.12). Achieving molecular complete remission (CR) post salvage therapy emerged as the main prognostic factor for second relapses in both univariate and multivariate analyses. Our findings support the efficacy of ATO-based therapies in first relapse and enhance the role of molecular remission as an independent outcome predictor in both first and second APL relapses. Background: The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has radically improved the prognosis of acute promyelocytic leukemia (APL), with cure rates above 80%. While relapse occurs in less than 20% of cases, addressing this issue remains challenging. Identifying effective salvage therapies for relapsed APL is crucial to improve patient outcomes. Methods: A retrospective analysis was performed on a multicentric cohort of 67 APL patients in first relapse, treated in three Italian hematology centers from June 1981 to November 2021. The overall survival (OS) and cumulative incidence of relapse (CIR) were calculated, and predictive factors were assessed using Cox regression models. Results: Overall, 61 patients (91%) received ATO ± ATRA (40.3%), chemo-based regimens (40.3%), or ATRA ± Gemtuzumab ozogamicin (GO) (10.4%). Complete remission (CR) was achieved in 98.2% of patients (molecular CR, n = 71.4%). With a median follow-up time of 54.5 months, the 5-year OS was 73% in the ATO ± ATRA group, 44% in the chemo-based group, and 29% in the ATRA ± GO group (p = 0.035). The 5-year OS rate was also higher for transplant recipients vs. non-recipients within the chemo-based cohort (50% vs. 33%, p = 0.017), but not in the ATO-based cohort (p = 0.12). ATO-based salvage therapy resulted in better OS in both univariate (p = 0.025) and multivariate analyses (p = 0.026). The 2-year CIR was higher in patients without molecular CR vs. patients in molecular CR (66% vs. 24%, p = 0.034). Molecular CR was a significant predictor of second relapse in both univariate (p = 0.035) and multivariate analyses (p = 0.036). Conclusions: Our findings support the efficacy of ATO-based therapies in first relapse of APL and confirm the achievement of molecular remission as an independent outcome predictor in both first and second APL relapse. [ABSTRACT FROM AUTHOR]

The recovery of As from copper anode slime by chlorination leaching--NaH2PO2 selective reduction process was studied. The effects of liquid volume to solid mass ratio, initial acidity, leaching temperature, initial Cl- mass concentration and leaching time on the leaching rate of As. The effects of reduction temperature, molar ratio of NaH2PO2 to As and reduction time on the precipitation rate of As were investigated. The results show that the optimum chlorination leaching conditions are initial acidity of 220 g/L, liquid volume to solid mass ratio of 6/1, leaching temperature of 70 °C, initial Cl mass concentration of 150 g/L and leaching time of 2.5 h. The optimum reduction conditions are reduction temperature of 80 °C, molar ratio of NaH2PO2 to As of 2/1, reduction time of 2 h. Under the optimal conditions the average mass fraction of As is 90.44%, and the product quality can meet the refining requirements of elemental arsenic. [ABSTRACT FROM AUTHOR]

Wolverines are facultative scavengers that feed near the top of terrestrial food chains. We characterized concentrations of mercury and other trace elements in tissues of wolverine from a broad geographic area, representing much of their contemporary distribution in northwestern North America. We obtained tissues from 504 wolverines, from which mercury was measured on muscle (n = 448), kidney (n = 222), liver (n = 148), hair (n = 130), and brain (n = 52). In addition, methylmercury, seven trace elements (arsenic, cadmium, chromium, cobalt, lead, nickel, selenium), and arsenic compounds were measured on a subset of samples. Concentrations of mercury and other trace elements varied between tissues and were generally highest in kidney compared to brain, liver and muscle. Mercury was predominately as methylmercury in brain and muscle, but largely as inorganic mercury in liver and kidney. Mercury concentrations of hair were moderately correlated with those of internal tissues (Pearson r = 0.51–0.75, p ≤ 0.004), making hair a good non-lethal indicator of broad spatial or temporal differences in mercury exposure to wolverine. Arsenobetaine was the dominant arsenic compound identified in tissues, and arsenite, arsenocholine and dimethylarsinic acid were also detected. A preliminary risk assessment suggested the cadmium, lead, mercury, and selenium concentrations in our sample of wolverines were not likely to pose a risk of overt toxicological effects. This study generated a comprehensive dataset on mercury and other trace elements in wolverine, which will support future contaminants study of this northern terrestrial carnivore. [ABSTRACT FROM AUTHOR]

Arsenic-containing SbCl3 solution is a typical leachate in the extraction of antimony from antimony ores and smelting residues. Efficiently controlling the hydrolysis behavior of antimony and arsenic is crucial for obtaining target antimony products and remove impurity arsenic. This study mainly investigates the hydrolysis behavior of arsenic and antimony in arsenic-containing SbCl3 solution by manipulating As(III)/As(V) concentration, temperature, the hydrolysis ratio and Cl− concentration. Meanwhile, the composition and phase transformation mechanism of hydrolysates are analyzed. The results reveal that during the hydrolysis of Sb(III), As(III) almost does not hydrolyze, while As(V) hydrolyzes concurrently with Sb(III). With increasing As(V) concentration, the hydrolysates of Sb(III) shift from crystalline Sb4O5Cl2 to Sb8O8(OH)6·xCl2 and finally to amorphous arsenate antimonates. Furthermore, the increase of the hydrolysis ratio promotes the phase transformation of the hydrolysates from Sb4O5Cl2 to Sb8O8(OH)6·xCl2, while elevated temperature inhibits the occurrence of this transformation. Variation of Cl− concentration will not have a significant impact on the hydrolysis process and the phase of the hydrolysates. According to the composition of hydrolysates, for obtaining antimony hydrolysates with lower As(V) content, it is recommended to minimize the As(V) concentration, control a moderate hydrolysis ratio (1:8–1:12) and increase the hydrolysis temperature during the hydrolysis process. [ABSTRACT FROM AUTHOR]

We report the synthesis of arsenic heterocycles derived from saccharides 2–4 and AsCl3. Compounds 5 and 6 are stable in aqueous solutions, DMSO, or methanolic solutions. However, NMR and HPLC studies revealed that intramolecular trans‐esterification processes leads to dynamic equilibria. Theoretical studies revealed that three arsenates and two arsoranes participate in these intramolecular equilibria and account for the experimental spectroscopy and HPLC results. Through the correlation between the experimental and theoretical 13C NMR spectra, we proposed the speciation of arsenic Compounds 5 and 6. Moreover, experimental and theoretical IR spectra demonstrated that arsenates 5 A and 6 A predominate in the solid state. QTAIM studies were performed to explain the chemical shifts in the 13C NMR spectra. Biological studies suggest that the structural flexibility of Compounds 5 and 6 increase the cytotoxic and antiproliferative activities of these compounds. [ABSTRACT FROM AUTHOR]

In many places in the world, groundwater contains arsenic compounds. To purify water containing arsenic effectively, arsenic (III) compounds must be oxidised. The subject of this study is oxidation of arsenic (III) compounds in an aqueous solution in a flow column mode. The industrial arsenic oxidation technology involving aggressive oxidising agents such as chlorine or ozone, which is used most commonly today, has a number of serious disadvantages. The most problematic include extremely high risks for human health and the environment, the process cost and overall complexity. Catalytic oxidation of arsenic (III) compounds with atmospheric oxygen is an alternative that is free from the above disadvantages. Previously, the author studied the process of effective catalytic oxidation of arsenic (III) on the new active manganese dioxide (NADM) he had synthesised. Later, however, it turned out that NADM has a significant drawback: during prolonged flow column stops, its catalytic activity drops sharply. This work proposes both a theoretical justification for and a solution to this problem. A new calcium-doped active manganese dioxide NADM-Ca0.5 was synthesised. It was shown that NADM-Ca0.5 demonstrates high catalytic activity towards arsenic (III). The fact that flow column long stops do not affect its catalytic activity was also experimentally confirmed. On the basis of the study results, some theoretical aspects are also discussed of the mechanism for catalytic oxidation of arsenic (III) with oxygen on active manganese dioxide in an aqueous solution. For successful industrial implementation of the technology for catalytic oxidation of arsenic (III) compounds on NADM-Ca0.5, experimental work on pilot plants in the field is required and further laboratory research is needed in order to develop a detailed theoretical basis for the mechanism of catalytic oxidation of arsenic in aqueous solutions. The results of this work are of interest for both industrial companies specialising in water purification from arsenic compounds, and scientists and researchers studying catalytic oxidation of arsenic (III), as well as heterogeneous catalytic oxidation with oxygen in general. [ABSTRACT FROM AUTHOR]

We synthesized arsenic analogs of a tridentate PPP ligand, bis[2‐(diphenylphosphino) phenyl] phenylphosphine, achieving yields of 40 % to 71 %. Additionally, we prepared copper (I) halide (CuX, X=Br, I) complexes with these ligands, with yields between 43 % and 84 %. Using both experimental and computational methods, we examined their structures and photophysical characteristics. Single crystal X‐ray diffraction showed that all eight complexes had distorted tetrahedral geometries. These complexes exhibited photoluminescence with emission bands peaking from 506 nm to 551 nm and quantum yields up to 0.92 at room temperature. Emission lifetimes varied and showed no direct correlation with quantum yields or wavelengths. Physical manipulation and solvent variations significantly altered their photoluminescent properties. DFT and TD‐DFT calculations revealed that higher arsenic content increased spin‐orbit coupling constants, with iodide complexes performing better than bromide ones due to heavier elements enhancing spin‐orbit coupling. Substituting phosphorus with arsenic significantly affected the luminescence quantum yield and lifetime, demonstrating the heavy‐atom effect of arsenic. The position of arsenic in the ligands critically influenced the photophysical outcomes of the CuX complexes. [ABSTRACT FROM AUTHOR]

Arsenic is highly toxic to the human bladder. In the present study, we established a human bladder epithelial cell line that closely mimics normal human bladder epithelial cells by immortalizing primary uroplakin 1B-positive human bladder epithelial cells with human telomerase reverse transcriptase (HBladEC-T). The uroplakin 1B-positive human bladder epithelial cell line was then used to evaluate the toxicity of seven arsenicals (iAsV, iAsIII, MMAV, MMAIII, DMAV, DMAIII, and DMMTAV). The cellular uptake and metabolism of each arsenical was different. Trivalent arsenicals and DMMTAV exhibited higher cellular uptake than pentavalent arsenicals. Except for MMAV, arsenicals were transported into cells by aquaglyceroporin 9 (AQP9). In addition to AQP9, DMAIII and DMMTAV were also taken up by glucose transporter 5. Microarray analysis demonstrated that arsenical treatment commonly activated the NRF2-mediated oxidative stress response pathway. ROS production increased with all arsenicals, except for MMAV. The activating transcription factor 3 (ATF3) was commonly upregulated in response to oxidative stress in HBladEC-T cells: ATF3 is an important regulator of necroptosis, which is crucial in arsenical-induced bladder carcinogenesis. Inorganic arsenics induced apoptosis while MMAV and DMAIII induced necroptosis. MMAIII, DMAV, and DMMTAV induced both cell death pathways. In summary, MMAIII exhibited the strongest cytotoxicity, followed by DMMTAV, iAsIII, DMAIII, iAsV, DMAV, and MMAV. The cytotoxicity of the tested arsenicals on HBladEC-T cells correlated with their cellular uptake and ROS generation. The ROS/NRF2/ATF3/CHOP signaling pathway emerged as a common mechanism mediating the cytotoxicity and carcinogenicity of arsenicals in HBladEC-T cells. [ABSTRACT FROM AUTHOR]

From at least the fifteenth to late nineteenth centuries, peasants in the Austrian province of Styria ate up to several hundred milligrams of arsenic trioxide or sulfide daily or weekly for periods up to a number of years. Taking these doses of arsenic was believed to increase muscular power and enhance the beauty and sexual attractiveness of peasant girls. There do not appear to be contemporaneous records of the known consequences of chronic arsenic exposure. The historical records of arsenic eating there are reviewed and appear to be valid. The benefits are subjective judgements by arsenic eaters. The lack of objective reports of the anticipated external and internal clinical and pathological effects of arsenic poisoning depends on a smaller number of clinical accounts and autopsy reports and the general medical literature of those times, so it is weaker, but it is consistent. Why the arsenic eaters did not show the well-known consequences of prolonged exposure to high doses of arsenic is not known. Possible explanations include increases in detoxifying metabolism in the consumers due to induced genomic changes and selection in people and in the gut microbiome, as shown in other populations. Whether these effects would suffice to protect people against their high doses of arsenic has not been explored. Although the nature and mechanisms of arsenic toxicity have been extensively described, much still remains to be discovered. [ABSTRACT FROM AUTHOR]

Inorganic arsenic species exist in the environment as a result of both natural sources, such as volcanic and geothermal activities, and geological formations, as well as anthropogenic activities, including smelting, exploration of fossil fuels, coal burning, mining, and the use of pesticides. These species deposit in water, rocks, soil, sediments, and the atmosphere. Arsenic-contaminated drinking water is a global public health issue because of its natural prevalence and toxicity. Therefore, chronic exposure to arsenic can have deleterious effect on humans, including cancer and other diseases. This work describes the mechanisms of environmental exposure to arsenic, molecular regulatory factors involved in its metabolism, genetic polymorphisms affecting individual susceptibility and the toxic effects of arsenic on human health (oxidative stress, DNA damage and cancer). We conclude that the role of single nucleotide variants affecting urinary excretion of arsenic metabolites are highly relevant and can be used as biomarkers of the intracellular retention rates of arsenic, showing new avenues of research in this field. • Inorganic arsenic exposure and its impact on the human health. • Genetic polymorphisms and it role on urinary excretion of arsenic metabolites. • Susceptibility and potential risk of toxic effects by ingestion of inorganic arsenic. [ABSTRACT FROM AUTHOR]

Introduction: Arsenate, a metalloid, acting as an analog to phosphate, has a tendency to accumulate more readily in plant species, leading to adverse effects. Methods: In the current study, sunflower seedlings were exposed to 25, 50 and 100 ppm of the arsenic. Results: Likewise, a notable reduction (p<0.05) was observed in the relative growth rate (RGR) by 4-folds and net assimilation rate (NAR) by 75% of Helianthus annuus when subjected to arsenic (As) stress. Nevertheless, the presence of Staphylococcus arlettae, a plant growth-promoting rhizobacterium with As tolerance, yielded an escalation in the growth of H. annuus within Ascontaminated media. S. arlettae facilitated the conversion of As into a form accessible to plants, thereby, increasing its uptake and subsequent accumulation in plant tissues. S. arlettae encouraged the enzymatic antioxidant systems (Superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT)) and non-enzymatic antioxidants (flavonoids, phenolics, and glutathione) in H. annuus seedlings following substantial As accumulation. The strain also induced the host plant to produce osmolytes like proline and sugars, mitigating water loss and maintaining cellular osmotic balance under As-induced stress. S. arlettae rectified imbalances in lignin content, reduced high malonaldehyde (MDA) levels, and minimized electrolyte leakage, thus counteracting the toxic impacts of the metal. Conclusion: The strain exhibited the capability to concurrently encourage plant growth and remediate Ascontaminated growth media through 2-folds rate of biotransformation and bio-mobilization. [ABSTRACT FROM AUTHOR]

Arsenic is one of the most toxic elements present in the environment, especially in water. The World Health Organization (WHO) recommends a maximum concentration of arsenic in drinkable water of 10 μg/l (10 ppb). Sensors implementing Surface Enhanced Raman Scattering (SERS) can detect chemical species at low concentrations. The aim of this study is to compare two kinds of silver-coated SERS substrates for detection and speciation of trace, trivalent and pentavalent, inorganic arsenic compounds. One type of substrate was prepared by a classical thermal evaporation technique, and the second type by an electroless process. The thermally evaporated substrates allowed the detection of As(III) only, at a limit of detection (LOD) of approximately 50 mg/l, whereas As(V) could not be detected at any analyte concentration. The electroless substrates allow one to differentiate As(III) and As(V) with a LOD 1 μg/l (1 ppb) equal for each valency, below the WHO recommendation. The electroless substrates show a very large sensitivity across up to five orders of magnitude in terms of analyte concentration. Although the SERS intensity shows a nonlinear behavior over this range of concentrations, these preliminary results are encouraging in the framework of the demonstration of trace As SERS sensors in drinkable water. [ABSTRACT FROM AUTHOR]

A liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source operating at a nominal power of 30 W and solution flow rate of 30 µL min−1 and supported in a He sheath gas flow rate of 500 mL min−1 was interfaced to an Orbitrap mass spectrometer and assessed for use in rapid identification of inorganic and organic arsenic species, including As(III), As(V), monomethylarsonic acid, dimethylarsinic acid, and arsenobetaine in a 2% (v/v) nitric acid medium. Mass spectral acquisition in low-resolution mode, using only the ion trap analyzer, provided detection of protonated molecular ions for AsBet (m/z 179), DMA (m/z 139), MMA (m/z 141), and As(V) (m/z 143). As(III) is oxidized to As(V), likely due to in-source processes. Typical fragmentation of these compounds resulted in the loss of either water or methyl groups, as appropriate, i.e., introducing DMA also generated ions corresponding to MMA and As(V) as dissociation products. Structure assignments were also confirmed by high-resolution Orbitrap measurements. Spectral fingerprint assignments were based on the introduction of solutions containing 5 µg mL−1 of each arsenic compound. [ABSTRACT FROM AUTHOR]

Organic arsenic compounds such as p-aminophenylarsine oxide (p-APAO) are easier for structural optimization to improve drug-like properties such as pharmacokinetic properties, therapeutic efficacy, and target selectivity. In order to strengthen the selectivity of 4-(1,3,2-dithiarsinan-2-yl) aniline 7 to tumor cell, a thiourea moiety was used to strengthen the anticancer activity. To avoid forming a mixture of α/β anomers, the strategy of 2-acetyl's neighboring group participation was used to lock the configuration of 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate from 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide. 1-(4-(1,3,2-dithiarsinan-2-yl) aniline)-2-N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranos-1-yl)-thiourea 2 can increase the selectivity of human colon cancer cells HCT-116 (0.82 ± 0.06 μM vs. 1.82 ± 0.07 μM) to human embryonic kidney 293T cells (1.38 ± 0.01 μM vs. 1.22 ± 0.06 μM) from 0.67 to 1.68, suggesting a feasible approach to improve the therapeutic index of arsenic-containing compounds as chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Exposure to inorganic arsenic (As) is recognized as a risk factor for non-melanoma skin cancer (NMSC). We followed up with 7000 adults for 6 years who were exposed to As. During follow-up, 2.2% of the males and 1.3% of the females developed basal cell carcinoma (BCC), while 0.4% of the male and 0.2% of the female participants developed squamous cell carcinoma (SCC). Using a panel of more than 400 cancer-related genes, we detected somatic mutations (SMs) in the first 32 NMSC samples (BCC = 26 and SCC = 6) by comparing paired (tissue–blood) samples from the same individual and then comparing them to the SM in healthy skin tissue from 16 participants. We identified (a) a list of NMSC-associated SMs, (b) SMs present in both NMSC and healthy skin, and (c) SMs found only in healthy skin. We also demonstrate that the presence of non-synonymous SMs in the top mutated genes (like PTCH1, NOTCH1, SYNE1, PKHD1 in BCC and TP53 in SCC) significantly affects the magnitude of differential expressions of major genes and gene pathways (basal cell carcinoma pathways, NOTCH signaling, IL-17 signaling, p53 signaling, Wnt signaling pathway). These findings may help select groups of patients for targeted therapy, like hedgehog signaling inhibitors, IL17 inhibitors, etc., in the future. [ABSTRACT FROM AUTHOR]

Observation of arsenic water treatment adsorption media in the treated water of several homes with high arsenic private wells led to the hypothesis that treatment media was escaping the treatment systems and entering the plumbing and drinking water. Our research at 62 homes identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system in 71% of the homes. This is a potential health hazard as ingesting arsenic treatment media or water softener resin may lead to an elevated ingestion exposure to arsenic and other contaminants. Potential causes of media escape from the treatment systems include media observed to be smaller in size than specifications and media breaking into smaller pieces. One interim solution to media escape is installation of a post‐treatment sediment filter. New developments in media durability or treatment system design and maintenance may be needed to prevent media escaping into drinking water. Practitioner Points: Arsenic in private wells is often treated with point‐of‐entry whole house adsorption systems.Arsenic adsorption treatment media and/or water softener resin was observed in treated water at 44 of 62 homes inspected.Water treatment media escaping into treated water is a potential hazardous exposure pathway.Potential causes and solutions are discussed. [ABSTRACT FROM AUTHOR]

The global concern over arsenic contamination in water due to its natural occurrence and human activities has led to the development of innovative solutions for its detection and remediation. Microbial metabolism and mobilization play crucial roles in the global cycle of arsenic. Many microbial arsenic-resistance systems, especially the ars operons, prevalent in bacterial plasmids and genomes, play vital roles in arsenic resistance and are utilized as templates for designing synthetic bacteria. This review novelty focuses on the use of these tailored bacteria, engineered with ars operons, for arsenic biosensing and bioremediation. We discuss the advantages and disadvantages of using synthetic bacteria in arsenic pollution treatment. We highlight the importance of genetic circuit design, reporter development, and chassis cell optimization to improve biosensors' performance. Bacterial arsenic resistances involving several processes, such as uptake, transformation, and methylation, engineered in customized bacteria have been summarized for arsenic bioaccumulation, detoxification, and biosorption. In this review, we present recent insights on the use of synthetic bacteria designed with ars operons for developing tailored bacteria for controlling arsenic pollution, offering a promising avenue for future research and application in environmental protection. [ABSTRACT FROM AUTHOR]

The controlling hydrogeochemical processes of an intermontane aquifer in central Mexico were identified through multivariate statistical analysis. Hierarchical cluster (HCA) and k-means clustering analyses were applied to Na+, K+, Ca2+, Mg2+, F−, Cl−, SO42−, NO3−, HCO3−, As, pH and electrical conductivity in 40 groundwater samples collected from shallow and deep wells, where As and F− are contaminants of concern. The effectiveness of each hierarchical and k-means clustering method in explaining solute concentrations within the aquifer and the co-occurrence of arsenic and fluoride was tested by comparing two datasets containing samples from 40 and 36 wells, the former including ionic balance outliers (>10%). When tested without outliers, cluster quality improved by about 5.4% for k-means and 7.3% for HCA, suggesting that HCA is more sensitive to ionic balance outliers. Both algorithms yielded similar clustering solutions in the outlier-free dataset, aligning with the k-means solution for all 40 samples, indicating that k-means was the more robust of the two methods. k-means clustering resolved fluoride and arsenic concentrations into four clusters (K1 to K4) based on variations in Na+, Ca2+, As, and F−. Cluster K2 was a Na-HCO3 water type with high concentrations of As and F. Clusters K1, K3, and K4 exhibited a Ca-HCO3, Na-Ca-HCO3, and Ca-Na-HCO3 water types, respectively, with decreasing As and F concentrations following the order K2 > K3 > K1 > K4. The weathering of evaporites and silicates and Na-Ca ion exchange with clays were the main processes controlling groundwater geochemistry. The dissolution of felsic rocks present in the aquifer fill is a likely source of As and F−, with evaporation acting as an important concentration factor. [ABSTRACT FROM AUTHOR]

Arsenic pollution is caused by industrial activities of human beings such as the mineral product manufacturing industry and metal industries. Arsenic pollution can cause nervous system and cardiovascular diseases in humans and destroy various water-based ecosystems. So far, different chemical analysis equipment is being utilized to carry out measurements of arsenic. However, conventional chemical analysis techniques are restricted by their needs for large or expensive equipment, which prevents convenient and rapid measurement. Here, we show that convenient measurements of arsenic can be conducted through the utilization of silica that has been modified with methylene blue molecules (MB-Silica). Several studies have reported that the interaction of methylene blue (MB) with arsenic in aqueous solution leads to color variations caused by oxidation-reduction reactions. Taking these alterations in colors into consideration, we have developed a convenient approach for arsenic detection by synthesizing MB-Silica. Furthermore, by varying the MB concentration during synthesis, arsenic ions can be detected with various concentration gradients, validating the feasibility of aqueous arsenic detection. Since the possibility of detecting arsenic using MB-silica, developed in this study, was successfully confirmed, it is anticipated that the MB-silica will be extensively used to detect arsenic in the field. [ABSTRACT FROM AUTHOR]

Environmental context: Seaweeds are known to accumulate high levels of arsenic, and cellular concentrations may reach several orders of magnitude higher than that of the surrounding environment. Arsenic may be methylated by seaweed cells and further metabolised to water-soluble arsenic-containing sugars through unknown pathways. Whether these compounds are the result of a detoxification process or are produced with a biological purpose remains to be seen. Rationale: Seaweeds are known to accumulate high levels of arsenic, which may be subsequently metabolised to small, methylated compounds or become incorporated into large biological molecules such as arsenosugars. The mechanism of arsenosugars production in macroalgae is still largely unknown. Method: This study reports the arsenic speciation of 13 brown, red and green macroalgae collected in May 2021 and February 2022. Water-soluble arsenic speciation was measured using high-performance liquid chromatography–inductively coupled plasma–mass spectrometry (HPLC-ICP-MS) after extraction with a 3% (v/v) hydrogen peroxide solution. Results: Arsenosugars were found to account for the majority of the extracted arsenic in all seaweed samples (>50%), with only small amounts of dimethylarsinate and monomethylarsonate present. Levels of toxic iAs were also low (−1). Sulfur-containing arsenosugars were the dominant arsenicals in brown macroalgae, whereas the phosphate ribose was most abundant in red and green. Discussion: The majority of seaweed species appear to have the ability to synthesise all four arsenosugar derivatives; however, it is unclear why some are produced in higher abundances. The production of arsenosugars may be an efficient way of excluding arsenic from the cytosol, or may serve as useful components in the cell wall matrix, as extremely high levels can be tolerated by the seaweed with no ill effects. AsSug-gly and AsSug-PO4 were detected in every sample analysed, which might suggest that AsSug-gly is the starting point for AsSug-PO4, which could be formed by AsSug-gly binding to phosphate-containing lipids in the cell membrane. Further studies should use both imaging and speciation techniques to investigate the formation of arsenosugars. Environmental context. Seaweeds are known to accumulate high levels of arsenic, and cellular concentrations may reach several orders of magnitude higher than that of the surrounding environment. Arsenic may be methylated by seaweed cells and further metabolised to water-soluble arsenic-containing sugars through unknown pathways. Whether these compounds are the result of a detoxification process or are produced with a biological purpose remains to be seen. (Image credit: Rebecca Sim.) [ABSTRACT FROM AUTHOR]

Three novel binary barium arsenides, Ba3As4, Ba5As4, and Ba16As11, were synthesized and their crystal and electronic structures were investigated. Structural data collected via the single-crystal X-ray diffraction method indicate that the anionic substructures of all three novel compounds are composed of structural motifs based on the homoatomic As–As contacts, with [As2]4− dimers found in Ba5As4 and Ba16As11, and an [As4]6− tetramer found in Ba3As4. Ba3As4 and Ba5As4 crystallize in the orthorhombic crystal system—with the non-centrosymmetric space group Fdd2 (a = 15.3680(20) Å, b = 18.7550(30) Å, c = 6.2816(10) Å) for the former, and the centrosymmetric space group Cmce (a = 16.8820(30) Å, b = 8.5391(16) Å, and c = 8.6127(16) Å) for the latter—adopting Eu3As4 and Eu5As4 structure types, respectively. The heavily disordered Ba16As11 structure was solved in the tetragonal crystal system with the space group P 4 ¯ 2 1 m (a = 12.8944(12) Å and c = 11.8141(17) Å). The Zintl concept can be applied to each of these materials as follows: Ba3As4 = (Ba2+)3[As4]6−, Ba5As4 = (Ba2+)5(As3−)2[As2]4−, and 2 × Ba16As11 = (Ba2+)32(As3−) ≈ 20[As2]4− ≈ 1, pointing to the charge-balanced nature of these compounds. Electronic structure calculations indicate narrow bandgap semiconducting behavior, with calculated bandgaps of 0.47 eV for Ba3As4, 0.34 eV for Ba5As4, and 0.33 eV for Ba16As11. [ABSTRACT FROM AUTHOR]

Minimizing human exposure to arsenic (As) and ensuring an adequate dietary intake of selenium (Se) are significant issues in research on food sources. This study measured the content of As and Se in the muscles, gills, liver, and gonads of the fish round goby (Neogobius melanostomus) to assess the benefits and risks associated with their consumption. This was achieved by using dietary reference intake (DRI), estimated daily intake (EDI), target hazard quotient (THQ), and carcinogenic risk (CR). The elements were analyzed by atomic absorption spectrometry. The mean concentrations of As and Se (in μg kg−1 wet weight) were 25.1 and 161.4 in muscle, 58.8 and 367.4 in liver, 47.4 and 635.3 in gonads, and 16.4 and 228.5 in gills, respectively. Arsenic in the muscle portion of fish accounted for up to 0.5% of the DRI, while Se constituted approximately 30% of the DRI. The EDI values were below the reference oral dose (RfD). The THQ were much below the permissible levels (THQ < 1), and the CR were at least within the permissible limit (CR < 10−4). With regard to the As content, round goby muscles can be deemed safe for consumers. They may also be a valuable source of Se in the human diet. However, round goby consumption should be monitored for the proper and safe intake of these elements. [ABSTRACT FROM AUTHOR]

In nature, arsenopyrite commonly acts as a companion mineral of chalcopyrite. As the arsenic in arsenopyrite easily exudes during the smelting process, arsenic will not only pollute the environment but also seriously affect human health once it flows into the nature, so it is important to realize the separation of arsenopyrite and chalcopyrite. Flotation is the most efficient and commonly used means to separate these two minerals. As the floatability of arsenopyrite is similar to that of chalcopyrite, the two are usually separated using depressants to suppress arsenic and float copper. The commonly used inorganic depressants in the separation process of copper and arsenic have drawbacks such as poor selectivity, strong toxicity, and environmental pollution. Therefore, the development of a clean, efficient and non-toxic inhibitor is the key to the separation of copper and arsenic. Ethylenediamine tetramethylene phosphoric acid (EDTMP) was developed as a novel depressant of arsenopyrite to achieve the separation of arsenopyrite and chalcopyrite. Micro-flotation experiments and artificial mixture flotation tests verified the flotation performance of EDTMP, and the mechanisms of EDTMP adsorbed on arsenopyrite and chalcopyrite surface were revealed by Zeta potential, FTIR spectrum, and XPS measurements. The flotation experiments revealed that EDTMP could effectively depress the flotation of arsenopyrite without affecting chalcopyrite at pH = 10 and SIBX concentration of 200 mg/L, and the results of zeta potential and FTIR spectrum indicated that EDTMP is preferred to adsorb on arsenopyrite, which hindered the adsorption between SIBX and arsenopyrite. XPS results showed that EDTMP chemisorbed on arsenopyrite surface in the form of P-O-Fe bonds, while EDTMP weakly physisorbed on chalcopyrite surface. EDTMP was a novel arsenopyrite depressant, which was highly efficient, clean, and environmentally friendly compared to traditional depressants. [ABSTRACT FROM AUTHOR]

Arsenic contamination not only complicates mineral processing but also poses environmental and health risks. To address these challenges, this research investigates the feasibility of utilizing Hyperspectral imaging combined with machine learning techniques for the identification of arsenic-containing minerals in copper ore samples, with a focus on practical application in sorting and processing operations. Through experimentation with various copper sulfide ores, Neighborhood Component Analysis (NCA) was employed to select essential wavelength bands from Hyperspectral data, subsequently used as inputs for machine learning algorithms to identify arsenic concentrations. Results demonstrate that by selecting a subset of informative bands using NCA, accurate mineral identification can be achieved with a significantly reduced the size of dataset, enabling efficient processing and analysis. Comparison with other wavelength selection methods highlights the superiority of NCA in optimizing classification accuracy. Specifically, the identification accuracy showed 91.9% or more when utilizing 8 or more bands selected by NCA and was comparable to hyperspectral data analysis with 204 bands. The findings suggest potential for cost-effective implementation of multispectral cameras in mineral processing operations. Future research directions include refining machine learning algorithms, exploring broader applications across diverse ore types, and integrating hyperspectral imaging with emerging sensor technologies for enhanced mineral processing capabilities. [ABSTRACT FROM AUTHOR]

In this study, arsenic (As) speciation was investigated in the freshwater alga Chlamydomonas reinhardtii treated with 20 μg/L arsenate using fractionation as well as ICP-MS/ESI-MS analyses and was compared with the known As metabolite profile of wild-grown Saccharina latissima. While the total As accumulation in C. reinhardtii was about 85% lower than in S. latissima, the relative percentage of arsenolipids was significantly higher in C. reinhardtii (57.0% vs. 5.01%). As-containing hydrocarbons and phospholipids dominated the hydrophobic As profile in S. latissima, but no As-containing hydrocarbons were detectable in C. reinhardtii. Instead for the first time, an arsenoriboside-containing phytol (AsSugPhytol) was found to dominate the hydrophobic arsenicals of C. reinhardtii. Interestingly, this compound and its relatives had so far been only found in green marine microalgae, open sea plankton (mixed assemblage), and sediments but not in brown or red macroalgae. This compound family might therefore relate to differences in the arsenic metabolism between the algae phyla. [ABSTRACT FROM AUTHOR]

Arsenic (As) pollution in cultivated soils poses a significant risk to the sustainable growth of agriculture and jeopardizes food security. However, the mechanisms underlying how zinc (Zn) regulates the toxic effects induced by As in plants remain poorly understood. Hence, this study aimed to explore the potential of ZnO as an effective and environmentally friendly amendment to alleviate As toxicity in rice, thereby addressing the significant risk posed by As pollution in cultivated soils. Through a hydroponic experiment, the study assessed the mitigating effects of different ZnO dosages (Zn5, 5 mg L-1; Zn15, 15 mg L-1; Zn30, 30 mg L-1) on rice seedlings exposed to varying levels of As stress (As0, 0 µM L-1; As25, 25 µM L-1). The findings of the study demonstrate significant improvements in plant height and biomass (shoot and root), with a notable increase of 16–40% observed in the Zn15 treatment, and an even more substantial enhancement of 29–53% observed in the Zn30 treatment under As stress, compared to respective control treatment. Furthermore, in the Zn30 treatment, the shoot and root As contents substantially reduced by 47% and 63%, respectively, relative to the control treatment. The elevated Zn contents in shoots and roots enhanced antioxidant enzyme activities (POD, SOD, and CAT), and decreased MDA contents (13-25%) and H2O2 contents (11-27%), indicating the mitigation of oxidative stress. Moreover, the expression of antioxidant-related genes, OsSOD-Cu/Zn, OsCATA, OsCATB, and OsAPX1 was reduced when rice seedlings were exposed to As stress and significantly enhanced after Zn addition. Overall, the research suggests that ZnO application could effectively mitigate As uptake and toxicity in rice plants cultivated in As-contaminated soils, offering potential solutions for sustainable agriculture and food security. [ABSTRACT FROM AUTHOR]

The use of probiotic lactobacilli has been proposed as a strategy to mitigate damage associated with exposure to toxic metals. Their protective effect against cationic metal ions, such as those of mercury or lead, is believed to stem from their chelating and accumulating potential. However, their retention of anionic toxic metalloids, such as inorganic arsenic, is generally low. Through the construction of mutants in phosphate transporter genes (pst) in Lactiplantibacillus plantarum and Lacticaseibacillus paracasei strains, coupled with arsenate [As(V)] uptake and toxicity assays, we determined that the incorporation of As(V), which structurally resembles phosphate, is likely facilitated by phosphate transporters. Surprisingly, inactivation in Lc. paracasei of PhoP, the transcriptional regulator of the two-component system PhoPR, a signal transducer involved in phosphate sensing, led to an increased resistance to arsenite [As(III)]. In comparison to the wild type, the phoP strain exhibited no differences in the ability to retain As(III), and there were no observed changes in the oxidation of As(III) to the less toxic As(V). These results reinforce the idea that specific transport, and not unspecific cell retention, plays a role in As(V) biosorption by lactobacilli, while they reveal an unexpected phenotype for the lack of the pleiotropic regulator PhoP. [ABSTRACT FROM AUTHOR]

An analytical method for determination of inorganic arsenic species in retorted oil shale slurry by atomic absorption spectrometry coupled to hydride technique with ultrasound assisted acidic extraction is reported. Trivalent arsenic measurement employed sample stabilization with a pH 4.5 prior to reaction with the reducing agent and analysis. In contrast, total inorganic As depended upon the pre-reduction of As(V) to As(III) with KI and ascorbic acid in 6.0 M HCl and of As(V) was estimated by the difference of the total inorganic As and As(III) concentrations. The limit of quantification was 3.7 mg kg−1 for As(III) and 1.3 mg kg−1 for itAs. [ABSTRACT FROM AUTHOR]

In the face of flourishing industrialization and global trade, heavy metal and metalloid contamination of the environment is a growing concern throughout the world. The widespread presence of highly toxic compounds of arsenic, antimony, and cadmium in nature poses a particular threat to human health. Prolonged exposure to these toxins has been associated with severe human diseases, including cancer, diabetes, and neurodegenerative disorders. These toxins are known to induce analogous cellular stresses, such as DNA damage, disturbance of redox homeostasis, and proteotoxicity. To overcome these threats and improve or devise treatment methods, it is crucial to understand the mechanisms of cellular detoxification in metal and metalloid stress. Membrane proteins are key cellular components involved in the uptake, vacuolar/lysosomal sequestration, and efflux of these compounds; thus, deciphering the multilevel regulation of these proteins is of the utmost importance. In this review, we summarize data on the mechanisms of arsenic, antimony, and cadmium detoxification in the context of membrane proteome. We used yeast Saccharomyces cerevisiae as a eukaryotic model to elucidate the complex mechanisms of the production, regulation, and degradation of selected membrane transporters under metal(loid)-induced stress conditions. Additionally, we present data on orthologues membrane proteins involved in metal(loid)-associated diseases in humans. [ABSTRACT FROM AUTHOR]

Acute promyelocytic leukemia (APL), which was once considered one of the deadliest types of leukemia, has become a curable malignancy since the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) as clinical treatments. ATO, which has become the first-line therapeutic agent for APL, is derived from the natural mineral product arsenic, exemplifying an important role of natural products in the treatment of APL. Many other natural products, ranging from small-molecule compounds to herbal extracts, have also demonstrated great potential for the treatment and adjuvant therapy of APL. In this review, we summarize the natural products and representative components that have demonstrated biological activity for the treatment of APL. We also discuss future directions in better exploring their medicinal value, which may provide a reference for subsequent new drug development and combination therapy programs. [ABSTRACT FROM AUTHOR]

The treatment of laboratory waste containing arsenic compounds should be part of the chemical analysis protocol in educational and research institutions. An alternative procedure for the treatment of these residues is proposed for the development of a didactic analytical route in the detection of As3+, As5+, MMA (monomethylarsonic acid) and DMA (dimethylarsinic acid). The treatment is based on the coprecipitation of inorganic arsenic species with a quaternary ammonium salt (tetra-n-butylammonium perchlorate) in suspension. Detection occurred by controlling the hydride generation reactions and Atomic Absorption Spectrometry. The methylated species MMA and DMA remain in the supernatant and can be monitored by adjusting the pH, concentration of the borohydride reducer, and the use of auxiliary reducers (hydroxylamine hydrochloride and KI). Satisfactory selective detectability was obtained for each arsenic species present in the waste sample. This work contributes to the development of experiments to be implemented in Qualitative Analytical Chemistry and Instrumental Analysis classes. The results allow to approach the chemical vapor generation, which is generally not well explored in undergraduate classes. Discussion of this procedure is supported by a teaching proposal based on the theory of nascent hydrogen for inorganic arsenic species and the nucleophilic performance of the hydride ion for methylated species. This approach allows the student to contextualize important concepts such as Lewis structure, oxidation state and kinetics of arsenic hydride generation reactions. This interdisciplinary contextualization forms a common theoretical basis, preparing and enabling the student to research speciation analysis by hydride generation and to understand the most accepted theories. [ABSTRACT FROM AUTHOR]

Arsenic can accumulate in freshwater biota, sometimes reaching potentially harmful levels. However, the toxicity of arsenic strongly depends on which arsenic species are present. Although organic species are considered less harmful than inorganic ones, they have not been extensively studied in freshwater environments, and drivers of variation in arsenic speciation among sites and taxa remain unclear. We assessed concentrations of two organic arsenic species, arsenobetaine (AsB) and dimethylarsinic acid (DMA), in fish and invertebrates from three lakes near Sudbury, Ontario, Canada—a region with widespread mining impacts. Both AsB and DMA were detected in most samples (n = 212), varying across a wide range of concentrations (<0.001–30.144 and <0.006–5.262 mg/kg dry wt, respectively). The lake with the most severe mining impacts typically had the highest concentrations (designated by square brackets []) of AsB and DMA. In contrast, the percentage of total arsenic made up by AsB (%AsB) and DMA (%DMA) did not vary significantly between lakes. Arsenic speciation in fish muscle varied with fish size, selenium concentrations, and trophic elevation (inferred from nitrogen stable isotope ratios δ15N), but relationships with dietary carbon source (inferred from carbon stable isotope ratios δ13C) were more varied. Within all three lake food webs, [AsB] and [DMA] typically underwent biodilution, decreasing with trophic elevation (i.e., δ15N). Although the aforementioned factors explained some variation in arsenic speciation, there remains considerable unexplained variation. Further studies on arsenic speciation in freshwater biota should target a wider diversity of taxa to better understand drivers of variation in arsenic speciation. In addition, research emphasizing the percentage of inorganic arsenic and other organic arsenic species is needed to improve environmental and human health risk assessments. Environ Toxicol Chem 2024;43:833–846. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Arsenic (As) is a toxic element for plants, animals and humans. The mitigation of As stress has been achieved via selenium (Se) and silica (Si) supplementations. However, the effects of combined application of Se and Si against As stress are not known. The present study was conducted to evaluate the effect of Se (0.5 and 1 mg L−1) and Si (10 and 30 mg L−1) on Oryza sativa L. (rice) subjected to during As (4 mg L−1) stress. The rice plants showed reduction in As accumulation in co-treatment of As + Se, As + Si and As + Se + Si in comparison to As alone treated plants (7 d). The maximum reduction of As accumulation in root and shoot was 57% and 64%, respectively in As + Se + Si treatment. The increase in enzymatic antioxidant system (superoxide dismutase, ascorbate peroxidase, glutathione peroxidase, glutathione reductase and glutathione-s-transferase) along with decrease in oxidative stress markers (lipid peroxidation, dehydroascorbate reductase, ascorbate oxidase and hydrogen peroxide) in As + Se + Si treatment as compared to As treatment signified elevated tolerance of rice plants to As stress. Gene expressions of enzymes involved in antioxidant defence and thiol metabolism were found to be significantly positively correlated with their respective biochemical activities. In conclusion an optimum combination of Se and Si can be used to effectively mitigate As toxicity in plants. [ABSTRACT FROM AUTHOR]

About 2.5 billion people rely on groundwater as their main drinking water source, and arsenic pollution within the groundwater system can cause serious short- and long-term health issues. Within the natural environment, arsenic generally exists as oxyanions which have two oxidation states, As(III) and As(V). Under ambient pH conditions, As(V) is primarily present as an anion (i.e., H2AsO4−) while As(III) tends to be uncharged (i.e., H3AsO3), making it much more difficult to remove As(III) through existing treatment techniques such as adsorption and reverse osmosis (RO). In Eastern Wisconsin, the dolomite and dolomite/sandstone aquifers represent a major drinking water source and high arsenic concentrations have been observed. Previous studies showed that arsenic can be released into private drinking water wells due to the oxidation of sulfide-bearing minerals with arsenic impurities that are usually dispersed within the dolomite and sandstone bedrock. However, there is a lack of information on the concentrations of each arsenic species as well as arsenic dynamics during water pumping/usage. The primary goals of this research were (1) to quantify the baseline concentrations of each arsenic species within selected Eastern Wisconsin private drinking water wells, and (2) to determine how the arsenic concentrations and species could be affected by continuous water usage. Our results showed that As(III) was the dominant species of arsenic, and during continuous water usage, there could be an upward trend in arsenic concentration (there was minimal change in arsenic speciation). Upon the completion of water pumping, arsenic concentrations decreased over time and returned to pre-pumping levels. Our findings highlighted the importance of quantifying the speciation and dynamics of arsenic during water use to the assessment of public health risks and the design of appropriate water treatment techniques. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis of a novel arsenic adsorption material, iron-modified hydrochar, by using different iron species, i.e., FeCl3·6H2O, FeSO4·7H2O, and Fe(NO3)3·9H2O. These hydrochars were prepared through a one-step hydrothermal carbonization process at 220 °C. This paper aims to explore the impact of different iron species on the characteristics of iron-modified hydrochars. XPS, XRD, SEM-mapping, and ICP-OES were employed to compare the physicochemical properties, iron binding stability, and arsenic adsorption capabilities of these iron-modified hydrochars. The results indicated that compared with FeCl3·6H2O and FeSO4·7H2O, hydrochar modified with Fe(NO3)3·9H2O exhibited a maximum iron retention rate of 84.2% and a maximum arsenic adsorption capacity of 11.19 mg/g. The study also examined the role of Fe(NO3)3·9H2O in the hydrothermal carbonization process, identifying key factors that enhance the iron content of hydrochars and improve their arsenic adsorption capacity. This research provided valuable insights into the improvement of the preparation efficiency of iron-modified hydrochars and their arsenic adsorption capabilities, revealing how different iron species influence the characteristics of hydrochars and offering beneficial information for the preparation of arsenic adsorption materials. [ABSTRACT FROM AUTHOR]

Arsenic compounds are widely used for the therapeutic intervention of multiple diseases. Ancient pharmacologists discovered the medicinal utility of these highly toxic substances, and modern pharmacologists have further recognized the specific active ingredients in human diseases. In particular, Arsenic trioxide (ATO), as a main component, has therapeutic effects on various tumors (including leukemia, hepatocellular carcinoma, lung cancer, etc.). However, its toxicity limits its efficacy, and controlling the toxicity has been an important issue. Interestingly, recent evidence has pointed out the pivotal roles of arsenic compounds in phase separation and membraneless organelles formation, which may determine their toxicity and therapeutic efficacy. Here, we summarize the arsenic compounds-regulating phase separation and membraneless organelles formation. We further hypothesize their potential involvement in the therapy and toxicity of arsenic compounds, highlighting potential mechanisms underlying the clinical application of arsenic compounds.

The total arsenic mass fraction as well as the arsenic speciation were studied in four different mushroom species with inductively coupled plasma mass spectrometry and high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry, respectively. Arsenic mass fractions detected in the mushrooms were covering a range from 0.3 to 22 mg As kg−1 dry mass. For the arsenic speciation, species like arsenobetaine, inorganic arsenic, or dimethylarsinic acid were found, which are commonly detected in mushrooms, but it was also proven that the recently discovered novel compound homoarsenocholine is present in Amanita muscaria and Ramaria sanguinea. Moreover, a previously unidentified arsenic species was isolated from Ramaria sanguinea and identified as trimethylarsonioacetamide, or in short: arsenobetaine amide. This new arsenical was synthesized and verified by spiking experiments to be present in all investigated mushroom samples. Arsenobetaine amide could be an important intermediate to further elucidate the biotransformation pathways of arsenic in the environment. [ABSTRACT FROM AUTHOR]

Simple Summary: This study explores the potential use of retinoic acid in treating a severe form of bladder cancer, known as basal muscle-invasive bladder cancer (MIBC), which is among the deadliest cancers in the United States of America. All-trans retinoic acid (tretinoin), commonly used in the differentiation therapy of blood cancer, is investigated in this study for its efficacy against MIBC. By treating bladder cancer cells with tretinoin, the study aimed to determine whether it could diminish the aggressive behavior of these cells. The findings show promising results, suggesting that tretinoin can indeed make the basal muscle cancer cells less aggressive by reducing cell proliferation and increasing differentiation markers. This research could lead to new treatment approaches that improve survival chances for patients with basal muscle-invasive bladder cancer. Bladder cancer (BC) is the eighth most common cause of cancer death in the United States of America. BC is classified into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Genetically, MIBCs are categorized into the more aggressive basal subtype or less aggressive luminal subtype. All-trans retinoic acid (tretinoin), the ligand for the RAR-RXR retinoic acid receptor, is clinically used as a differentiation therapy in hematological malignancies. This study aims to determine the effects of retinoic acid on arsenite-transformed malignant urothelial cells (UROtsa As), serving as a model for basal muscle-invasive bladder cancer. We treated three independent isolates of arsenite-transformed malignant human urothelial UROtsa cells (UROtsa As) with tretinoin for 48 h. Cell viability, proliferation, and apoptosis were analyzed using crystal violet staining and flow cytometry. mRNA and protein level analyses were performed using RT-qPCR and the Simple Western™ platform, respectively. Tretinoin was found to reduce cell proliferation and urosphere formation, as well as decrease the expression of basal markers (KRT1, KRT5, KRT6, EGFR) and increase the expression of luminal differentiation markers (GATA3, FOXA1). Mechanistically, the antiproliferative effect of tretinoin was attributed to the downregulation of c-myc. Our results suggest that targeting the retinoic acid pathway can diminish the aggressive behavior of basal muscle-invasive urothelial cancer and may enhance patient survival. [ABSTRACT FROM AUTHOR]

Simple Summary: Acute promyelocytic leukemia (APL) stands as a remarkable success in achieving high cure rates with chemotherapy-free treatment regimens. Despite these remarkable outcomes, hematologists managing patients with APL take into consideration the distinct side effects associated with the two dual differentiation agents, i.e., all-transretinoic acid (ATRA) and arsenic trioxide (ATO). The objective of this paper is to review relevant literature data and discuss the recommended management strategies of non-hematologic early and late complications that arosein patients diagnosed with APL who were treated with ATO and ATRA-based regimens. The hallmark of acute promyelocytic leukemia (APL) is the presence of the characteristic fusion transcript of the promyelocytic leukemia gene with the retinoic acid receptor α gene (PML::RARA). The PML::RARA fusion is a molecular target for all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Therapies based on ATRA plus ATO have excellent outcomes in terms of complete remission rates, overall survival, and achievement of deep and durable molecular responses with a very low incidence of relapse. However, although the combination of ATRA and ATO has lower hematologic toxicity than standard chemotherapy, its use is associated with a spectrum of distinctive toxicities, such as differentiation syndrome, liver toxicity, QT interval prolongation, and neurotoxicity. Rigorous monitoring of patients' clinical evolution is indispensable for identifying and addressing each complication. The objective is to maintain an equilibrium between treatment-induced adverse events and therapeutic efficacy. This paper focused on non-hematologic complications associated with the combination of ATRA and ATO. Additionally, we discuss late-onset complications of this therapy. In summary, the majority of treatment-related adverse events are manageable, self-limiting, and reversible. More so, there seems to be a lower incidence rate of secondary neoplasms compared to standard chemotherapy. However, further research is required to assess how the ATRA plus ATO regimen affects the emergence of additional comorbidities. [ABSTRACT FROM AUTHOR]

This article explores the synthesis and coordination behavior of 9,10-Diarsatriptycene, a unique molecule with potential applications in various fields. The authors focus on the synthesis of heavy pnictogen-containing DHT analogues using nonvolatile arsenic precursors, which eliminates the need for dangerous reagents. The structures of the synthesized compounds were analyzed, revealing the effects of the bridgehead element. The compounds were found to have different stability and coordination abilities, and one compound formed a supramolecular polymer structure. Further research is being conducted to explore the potential applications of these compounds. [Extracted from the article]

Arsenic is a common pollutant and impurity present in complex gold ores. In the pressure oxidation (POX) of refractory gold-bearing sulfides, a major environmental challenge is the treatment of the hazardous waste released from arsenic-bearing minerals during processing. While the bulk removal of arsenic from solution can occur during POX, the formation of stable arsenates relies on the operating conditions during POX and the subsequent curing stage. Herein, response surface methodology (RSM) and central composite design have been investigated as viable approaches for optimizing arsenic fixation during the curing of the POX product of arsenopyrite. Curing time (0–24 h) and temperature (60–120°C) were examined as the model variables for RSM optimization, and the performance was assessed via arsenic and iron precipitation, along with the change in free acid and sulfate concentrations. Experimental validation of the optimized model conditions demonstrated good agreement with the simulated outputs and provided a 10% increase in arsenic removal over the best model input. The formation of basic ferric arsenate sulfate and scorodite under these conditions was supported by RSM and confirmed via characterization. In the investigated system, the maximum arsenic removal occurs at a critical threshold temperature of 107°C, over which the scorodite formation decreases with temperature. Thermodynamic modeling revealed the preferable formation of soluble FeHAsO4+ complexes over scorodite above this threshold temperature, decreasing arsenic fixation at higher temperatures. [ABSTRACT FROM AUTHOR]