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The incorporation of sulfate (SO42−) into the scorodite (FeAsO4·2H2O) lattice is an important mechanism during arsenic (As) fixation in natural and engineered settings. However, spectroscopic evidence of SO42− speciation and local structure in scorodite lattice is still lacking. In this study, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), sulfur K-edge X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopic analyses in combination with density functional theory (DFT) calculations were used to determine the local coordination environment of SO42− in the naturally and hydrothermally synthesized scorodite. The SO42− retention in natural scorodite and the effect of pH value and initial Na+ concentration on the incorporation of SO42− in synthetic scorodite were investigated. The results showed that trace amounts of SO42− were incorporated in natural scorodite samples. Scanning electron microscopy (SEM) results revealed that SO42− was homogeneously distributed inside the natural and synthetic scorodite particles, and its content in the synthetic scorodite increased slightly with the initial Na+ concentration at pH of 1.2 and 1.8. The FTIR features and XANES results indicated that the coordination number (CN) of FeO6 octahedra around SO42− in scorodite lattice is four. The DFT calculation optimized interatomic distances of S-O were 1.45, 1.46, 1.48, and 1.48 Å with an average of ~1.47 Å, and the interatomic distances of S-Fe were 3.29, 3.29, 3.33, and 3.41 Å with an average of ~3.33 Å. EXAFS analysis gave an average S-O bond length of 1.47(1) and S-Fe bond length of 3.33(1) Å with a CNS-Fe = 4 for SO42− in the scorodite structure, in good agreement with the DFT optimized structure. The results conclusively showed that SO42− in the scorodite lattice may be in the form of a Fe2(SO4)3-like local structure. The present study is significant for understanding the formation mechanism of scorodite in natural environments and hydrometallurgical unit operations for waste sulfuric acid treatment.

Traumatic brain injury (TBI) and blunt thoracic aortic injury (BTAI) are the top two leading causes of death after blunt force trauma. Patients presenting with concomitant BTAI and TBI pose a specific challenge with respect to management strategy, because the optimal hemodynamic parameters are conflicting between the two pathologies. Early thoracic endovascular aortic repair (TEVAR) is often performed, even for minimal aortic injuries, to allow for the higher blood pressure parameters required for TBI management. However, the optimal timing of TEVAR for the treatment of BTAI in patients with concomitant TBI remains an active matter of controversy.The Aortic Trauma Foundation international prospective multicenter registry was used to identify all patients who had undergone TEVAR for BTAI in the setting of TBI from 2015 to 2020. The primary outcomes included delayed ischemic or hemorrhagic stroke, in-hospital mortality, and aortic-related mortality. The outcomes were examined among patients who had undergone TEVAR at emergent (6 vs ≥6 hours) or urgent (24 vs ≥24 hours) intervals.A total of 100 patients (median age, 43 years; 79% men; median injury severity score, 41) with BTAI (Society for Vascular Surgery BTAI grade 1, 3%; grade 2, 10%; grade 3, 78%; grade 4, 9%) and concomitant TBI who had undergone TEVAR were identified. Emergent repair was performed for 51 patients (51%). Comparing emergent repair (6 hours) to urgent repair (≥6 hours), no difference was found in delayed cerebral ischemic events (2.0% vs 4.1%; P = .614), in-hospital mortality (15.7% vs 22.4%; P = .389), or aortic-related mortality (2.0% vs 2.0%; P = .996) and no patient had experienced delayed hemorrhagic stroke. Likewise, repairs conducted in an urgent (24 hours) setting showed no differences compared with those completed in an emergent (≥24 hours) setting regarding delayed ischemic stroke (2.6% vs 4.3%; P = .548), in-hospital mortality (18.2% vs 21.7%; P = .764), or aortic-related mortality (1.3% vs 4.3%; P = .654), and no patient had experienced delayed hemorrhagic stroke.In contrast to prior retrospective efforts, results from the Aortic Trauma Foundation international prospective multicenter registry have demonstrated that neither emergent nor urgent TEVAR for patients with concomitant BTAI and TBI was associated with delayed stroke, in-hospital mortality, or aortic-related mortality. In these patients, the timing of TEVAR did not have an effect on the outcomes. Therefore, the decision to intervene should be guided by individual patient factors rather than surgical timing.

The removal of toxic elements (AsO4, SeO4, and MoO4) from wastewater by Hydrotalcites (HTLCs) has been noted, demonstrated, and implemented during mill neutralization processes of Uranium and other mining industries. Unfortunately, the exact knowledge of how these complex to commonly occurring MgAlFe(III)CO3SO4 HTLCs has remained uncertain. In this work, the use of K-edge Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS), Density Functional Theory (DFT), Powder X-ray Diffraction (PXRD), and Vibrational Spectroscopy (Infrared and Raman) were combined to answer this question. Based on this data, it was found that all these toxic elements formed surface outer-sphere like complexes with our MgAlFe HTLC. These results clear up the debate with respect to how these toxic elements interact with the MgAlFe HTLCs produced during such mill neutralization processes to correct current geochemical models and build a fundamental basis to create lacking surface complexation models of HTLCs.

Natural organic matter (NOM) has been considered a critical substance in the transport and transformation of arsenic. NOM is a complex mixture of multifunctional organic components with a wide molecular weight (MW) distribution, and it is necessary to understand the complexation of arsenic with MW-dependent NOM fractions. In this study, humic acid (HA) was chosen as the representative fraction of NOM to investigate the complexation mechanism with arsenic. The bulk HA sample was fractionated to five fractions by ultrafiltration technology, and the complexing property of HA fractions with arsenic was analyzed by the dialysis method. We observed that the acidic and neutral conditions favor the complexation of HA fractions with arsenate (As(V)). The HA fractions with molecular weight100 kDa, 1-10 kDa, and1 kDa have the stronger complexing capacity of As(V) than the other HA fractions. The bound As(V) percentage was positively associated with carboxyl content, phenolic content, and especially total acidity. A two-site ligand-binding model can describe the complexing capacity of arsenic onto HA fractions. The results can provide some fundamental information about the complexation of arsenic with MW-dependent HA fractions quantitatively.

The trace element of As and Sb have resulted in serious threats to ecological sustainability and human health in the Xijiang River basin, China. The geoaccumulation index (Igeo) results showed the sediment of Xijiang River was heavily contaminated by Sb as well as moderately contaminated by As. The effect of inorganic anions on the released As and Sb from the sediment increases in the following sequence: Cl- < SO42- < CO32- < PO43-. The presence of PO43- and CO32- had the greater effect over As mobility from the sediment compared to Sb. The effect of Ca(II), Al(III), and Mg(II) on the released amount of Sb from the sediment is negligible. Meanwhile, in the case of As, Ca(II) and Mg(II) had small impacts, but the released amount of As increased slightly with an increase of Al(III) concentration. The stability of As and Sb in the sediment was found to be the best at pH 5. The effect of organic compounds (≤ 0.05 mol/L) on the dissolved As percentages from the sediment increased in the following sequence: ethylenediaminetetraacetate (EDTA) < oxalate < citrate, and the effect on Sb release was oxalate < EDTA < citrate at concentrations (≤ 0.025 mol/L). This study provides the basic theoretical basis to manage the mobilization of co-contamination of sediments with As and Sb under the influence of external perturbations.

Arsenic (As) contamination in groundwater is a major problem in many countries, which causes serious health issues. In this paper, a novel method has been developed for the simultaneous removal of ROX and As(III/V) using the modified sorghum straw biochar (MSSB). The MSSB was characterized by X-ray diffraction, scanning electron microscopy, Fourier Transform Infrared, and Brunauer–Emmet–Teller (BET) surface area. The removal performance of MSSB for ROX, arsenite [As(III)], and arsenate (As(V)) was investigated using batch experiments. At pH of 5, the arsenic concentration of 1.0 mg/L, adsorbent dose of 1.0 g/L, the maximum adsorption capacities of ROX, As(III), and As(V) were 12.4, 5.3, and 23.0 mg/g, respectively. The adsorption behaviors were fit well with the Langmuir and the pseudo-second-order rate model. The results showed that MSSB acted as a highly effective adsorbent to simultaneously remove the composite pollution system consisted of ROX and As(III/V) in aqueous solutions, providing a promising method in environmental restoration applications.

In sediments, cadmium (Cd) contamination is an increasingly severe global problem facing environmental protection and human health. The mobility and biological toxicity of Cd are related to its chemical speciation. In this work, the Xihe River in Shenyang, China, was the representative of investigation to study the effect of grain size, pH, organic acids, inorganic anions, and cations on the chemical fractions of Cd in sediments by using the European Community Bureau of Reference (BCR) sequential extraction procedure. The result indicated that fine grains (< 63 μm, 0.57%) presented a relatively higher proportion of the oxidizable fraction Cd in the sediments, while the coarse grains (>250 μm, 78.02%) exhibited the more exchangeable/acid-soluble fraction (78.14 wt.%). The amount of Cd released from the sediment decreased dramatically with the pH from 2-6 and leveled off in the pH range of 8-10. The pH significantly influenced the more mobile fraction (Exchangeable/Acid soluble fraction (F1) and Reducible fraction (F2)), meaning that Cd can be a big-source of danger for the upper water environment. The influence of organic acid on the mobility of Cd in sediments followed the order: ethylenediaminetetraacetate acid (EDTA) > citric acid (CA) > tartaric acid (TA)> oxalic acid (OA). The impact of SO42-, Cl-, CO32- and NO3- was not evident in the release of Cd from the sediment. Besides, Ca(II) and Mg(II) had a major influence on F1 of Cd, and Al(III) and Fe(III) affected various chemical fractions of Cd. The study outcomes provide fundamental knowledge for understanding the mobility and potential ecotoxicological impacts of Cd in sediment.

La producción de café se está viendo afectada por cambios en los patrones climáticos y por la aparición de fenómenos meteorológicos que coinciden con importantes etapas fenológicas para este cultivo. El café es más sensible a variaciones del clima cuando se encuentra en las etapas de floración y el inicio del crecimiento del fruto, en este periodo cuatro fenómenos están presentes, que de acuerdo con su intensidad podría incidir de manera negativa. La etapa de maduración y cosecha es impactada por cinco fenómenos mientras que durante la etapa de crecimiento y llenado del grano sólo dos fenómenos la afectan. El Niño Oscilación del Sur (ENSO), en su fase negativa, intensificaría los efectos negativos. Sin embargo, no debe pasar inadvertido los efectos positivos del ENSO, en fase fría, en la temporada seca (diciembre-abril). Se deben buscar y estudiar estrategias de mitigación a la variación climática producto de los fenómenos meteorológicos, donde los sistemas agroforestales pueden ser una alternativa para enfrentar esta problemática.Palabras clave: Desarrollo reproductivo; ENSO; etapas fenológicas; eventos climáticos; regiones cafetaleras; variabilidad climática. Abstract: Coffee production is being affected by changes in weather patterns and the appearance of meteorological phenomena that coincide with important phenological stages for coffee cultivation. The coffee is more sensitive to the variations of the climate when it is in the stages of flowering and the beginning of the growth of the product, in this period four phenomena are present, and according to its intensity it could have a negative impact. The stage of maturation and harvest is shocking by five phenomena while during the growth stage and the grain volumes only two phenomena stress. El Niño-Southern Oscillation (ENSO), in its negative phase, would intensify the negative effects. However, the positive effects of the ENSO, in the cold phase, during dry season (December-April) should not go unnoticed. Mitigation strategies for climate variation due to meteorological phenomena must be sought and studied, where agroforestry systems can be an alternative to address this problem.Keywords: Reproductive Development; ENSO; Phenological Stages; Climatic Events; Coffee Regions; Climatic Variability.

To make the vast collections of well-documented human clinical samples archived in biobanks accessible for mass spectrometry imaging (MSI), recent developments have focused on the label-free top-down MS analysis of neuropeptides in sections of formalin-fixed, paraffin-embedded (FFPE) tissues. In analogy to immunohistochemistry (IHC), this variant of MSI has been designated MSHC (mass spectrometry histochemistry). Besides the detection and localization of neuropeptide and other biomolecular MS signals in these FFPE samples, there is great interest in their molecular identification and full characterization. We here used matrix assisted laser desorption ionization (MALDI) MSI employing ultrahigh-resolution FT-ICR MS on 2,5-dihydroxybenzoic acid (DHB) coated five-micron sections of human FFPE pituitary to demonstrate clear isotope patterns and elemental composition assignment of neuropeptides (with ∼1 ppm mass accuracy). Besides tandem MS fragmentation pattern analysis to deduce or confirm amino acid sequence information (Arg-vasopressin for the case presented here), there is a need for orthogonal primary structure characterization of the peptide-like MS signals of biomolecules desorbed directly off FFPE tissue sections. In the present work, we performed liquid extraction surface analysis (LESA) extractions on consecutive (uncoated) tissue slices. This enables the successful characterization by ion mobility MS of vasopressin present in FFPE material. Differences in sequence coverage are discussed on the basis of the mobility selected collision induced dissociation (CID), electron capture dissociation (ECD), and UV photodissociation (UVPD) MS/MS. Using Arg-vasopressin as model case (a peptide with a disulfide bridged ring structure), we illustrate the use of LESA in combination with a reduction agent for effective sequencing using mobility selected CID, ECD, and UVPD MS/MS.

International audience; In the context of new scaffolds obtained by photochemical reactions, Paternò-Büchi reactions between heteroaromatic, trifluoromethylphenyl ketone and electron rich alkenes to give oxetanes are described. A comprehensive study has then been carried out on the reaction of aromatic ketones with fluorinated alkenes. Depending on the substitution pattern at the oxetane ring, a metathesis reaction is described as a minor side process to give mono fluorinated alkenes. Overall, this last reaction corresponds to a photo-Wittig reactions and yield amid isosteres. In order to explain the uncommon regioselectivity of the Paternò-Büchi reaction with these alkenes, electrostatic-potential derived charges (ESP) have been determined. In a second computational study, the relative stabilities of the typical 1,4-diradical intermediates of the Paternò-Büchi reaction have been determined. The results well explain the regioselectivity. Further transformations of the oxetanes or previous functionalization of the fluoroalkenes open perspectives for oxetanes as core structures for biologically active compounds.

Antecedentes: Actualmente el 70% de los pacientes operados de ureteroscopia reciben colocación de catéter doble j debido a que se cree que disminuye la obstrucción secundaria a edema ureteral o a fragmentos de lito, pero la colocación no es inocua, ya que conlleva una gran variedad de efectos secundarios como frecuencia, urgencia, hematuria, disuria y tenesmo, así como un impacto económico. Nuestro objetivo es evaluar el manejo actual del catéter doble j en pacientes posoperados de ureteroscopia y los síntomas posquirúrgicos asociados. Materiales y métodos: Estudio retrospectivo de ureteroscopias realizadas en el Hospital Dr. Manuel Gea González durante el 2017 en pacientes mayores a 18 años. Se analizaron las frecuencias en readmisiones al servicio de urgencias durante la primera semana posoperatoria y los síntomas asociados al uso de catéter doble j, así como complicaciones posoperatorias. Resultados: Se registraron 105 ureteroscopias. El sexo masculino fue el predominante en hasta 55%; las ureteroscopias semirrígidas fueron las más prevalentes con un 71%. Se colocó preoperatoriamente catéter doble j en 69 pacientes y posoperatoriamente se colocaron en 41 pacientes. Durante el seguimiento los pacientes con colocación de catéter jj refirieron síntomas asociados a la colocación del catéter, lo cual ameritó visita a urgencias, encontrando únicamente asociación significativa para polaquiuria (p=0.001). Se obtuvo un total de 95 pacientes libre de litiasis, de los cuales a 61 (64.2%) se les colocó catéter doble j y 2 quedaron con litiasis residual y sin catéter. Conclusiones: De los 61 pacientes que se les colocó catéter doble j, 57 (82%) presentaron al menos un síntoma relacionado con el catéter; el 64.2% fueron ureteroscopias no complicadas a las cuales se les colocaron catéter doble j, por lo que creemos necesario realizar un estudio prospectivo y aleatorizado con un mayor número de pacientes para confirmar los resultados previamente reportados y establecer de manera más clara y objetiva las indicaciones para el uso del catéter doble j en nuestro hospital.

The biotic or abiotic reduction of nano-crystalline 2-line ferrihydrite (2-line FH) into more thermodynamically stable phases such as lepidocrocite-LP, goethite-GT, magnetite-MG, and hematite-HT plays an important role in the geochemical cycling of elements and nutrients in aqueous systems. In our study, we employed the use of in situ liquid cell (LC) and semi in situ analysis in an environmental TEM to gain further insights at the micro/nano-scale into the reaction mechanisms by which Fe(II)(aq) catalyzes 2-line FH. We visually observed for the first time the following intermediate steps: (1) formation of round and wire-shaped precursor nano-particles arising only from Fe(II)(aq), (2) two distinct dissolution mechanisms for 2 line-FH (i.e. reduction of size and density as well as breakage through smaller nano-particles), (3) lack of complete dissolution of 2-line FH (i.e. “induction-period”), (4) an amorphous phase growth (“reactive-FH/labile Fe(III) phase”) on 2 line-FH, (5) deposition of amorphous nano-particles on the surface of 2 line-FH and (6) assemblage of elongated crystalline lamellae to form tabular LP crystals. Furthermore, we observed phenomena consistent with the movement of adsorbate ions from solution onto the surface of a Fe(III)-oxy/hydroxide crystal. Thus our work here reveals that the catalytic transformation of 2-line FH by Fe(II)(aq) at the micro/nano scale doesn't simply occur via dissolution–reprecipitation or surface nucleation–solid state conversion mechanisms. Rather, as we demonstrate here, it is an intricate chemical process that goes through a series of intermediate steps not visible through conventional lab or synchrotron bulk techniques. However, such intermediate steps may affect the environmental fate, bioavailability, and transport of elements of such nano-particles in aqueous environments.

Skin repair is a significant aspect of human health. While the makeup of healthy stratum corneum and epidermis is generally understood, the mobilization of molecular components during skin repair remains largely unknown. In the present work, we utilize multimodal, in situ, mass spectrometry, and immunofluorescence imaging for the characterization of newly formed epidermis, following an initial acute wound for the first 96 h of epithelization. In particular, TOF-SIMS and confirmatory MALDI FT-ICR MS (/MS) analysis permitted the mapping of several lipid classes, including phospholipids, neutral lipids, cholesterol, ceramides, and free fatty acids. Endogenous lipid species were localized in discrete epidermal skin layers, including the stratum corneum (SC), stratum granulosum (SG), stratum basale (SB), and dermis. Experiments revealed that healthy re-epithelializing skin is characterized by diminished cholesterol sulfate signal along the stratum corneum toward the migrating epithelial tongue. The spatial distribution and relative abundances of cholesterol sulfate are reported and correlated with the healing time. The multimodal imaging approach enabled in situ high-confidence chemical mapping based on accurate mass and fragmentation pattern of molecular components. The use of postanalysis immunofluorescence imaging from the same tissue confirmed the localization of endogenous lipid species and Filaggrin and Cav-1 proteins at high spatial resolution (approximately a few microns).

The aim of the study was to describe an optical coherence tomography finding in Vogt-Koyanagi-Harada (VKH) disease and discuss its physiopathology. A 34-year-old Hispanic male was referred to the retina clinic, with 2 weeks of "drowsiness," headache, photopsia, and blurred vision. He was diagnosed with incomplete VKH. Optical coherence tomography, among other studies, was obtained, and a focal separation of the photoreceptor outer segments (OSs) from the inner neuroepithelium was observed. Here, we report a rare finding associated with VKH disease, which we called photoreceptor stretching and hypothesize it results from the presence of a spot of strong adherence between the OS of the photoreceptors and the retinal pigment epithelium.

Purpose To evaluate macular vasculature in diabetic retinopathy (DR) with optical coherence tomography angiography (OCTA) and to correlate vessel density (VD) with retinal sensitivity (RS) as a way to assess structural and functional findings in DR. Design Prospective observational cross-sectional study. Methods Diabetic patients with DR but no clinically significant diabetic macular edema (DME) and healthy subjects were included in this study. All of them underwent comprehensive ophthalmic examination, best corrected visual acuity (BCVA), OCTA with RS-3000 Advance AngioScan (Nidek, Gamagori, Japan) and microperimetry with MP-3 (Nidek, Gamagori, Japan). Retinal vascular density measured by OCT angiography in 9 areas was correlated with RS in the same 9 areas by Spearman correlation. Results In this study, 50 subjects were enrolled: 25 eyes of diabetic patients with DR and 25 eyes of non-diabetic subjects. Diabetic patients mean age was 51.88±13.62 years; non-diabetic subjects were 43.48±13.42 years. The BCVA was 20/25 in the diabetic group and 20/20 in the non-diabetic group. Mean RS was decreased in the DR group (27.68±2.71 dB) compared to the non-diabetic group (31.68±1.46 dB) (p

Hydrometallurgical FeIII-AsV coprecipitates, which are amorphous in nature, could re-crystallize gradually and pose risks of contamination to the environment. However, the mechanisms controlling the As behavior when the FeIII-AsV coprecipitates stored at different pHs is still not fully understood. This work systematically investigated the fate of As and the transformation process of the coprecipitates (Fe/As = ˜4) at different pHs and temperatures. XRD, EXAFS, HRTEM, and chemical extraction methods were employed to characterize the crystallinity degrees and the transformation products of the coprecipitates. The results showed that the coprecipitates are more stable at acidic pH than at neutral pH. For those samples aged at pH 4, the arsenic speciation includes poorly crystalline ferric arsenate (PCFA) and As adsorbed on 2-line ferrihydrite (Fh). Due to the presence of PCFA, the Fe/As molar ratio for the latter phase is much higher than the bulk Fe/As molar ratio (˜4 in this work) of the coprecipitates and controls As release. However, for those samples aged at pH 7, due to the fact that 2-line Fh is the major As-bearing phase, slight changes of the crystallinity degrees of 2-line Fh will trigger As release.

Osteoporosis is common in patients undergoing spine surgery, and carries a considerable risk of adverse outcomes. New methods to positively influence bone regeneration and spine fusion under osteoporotic conditions would be impactful. Neutralizing anti-Dickkopf-1 (DKK1) antibodies has been used as a bone anabolic agent, and recently reported by our group to aid in stem cell-mediated appendicular bone regeneration. Here, a small molecule designed as a DKK1 inhibitor, WAY-262611, was used to induce posterolateral spine fusion in an ovariectomized rat model. In vitro, pharmacological inhibition of DKK1 enhanced osteogenesis and Wnt signaling activity among rat bone marrow-derived stem/stromal cells (BMSCs). In vivo, systemic treatment with WAY-262611 promoted both chondrogenesis and osteogenesis within the spinal fusion site, and ultimately led to significant improvements in lumbar fusion as assessed by XR, μCT, histology and manual palpation assessments. No significant effect on osteoclast numbers or fusion site angiogenesis was detected, suggesting a primary direct effect on mesenchymal cells of the implantation site. Finally, evidence from human stem/stromal cells further demonstrated that pharmacologic inhibition of DKK1 promoted osteogenic differentiation in vitro. Taken together, our results suggest that targeting DKK1 promotes local bone formation and suggests potential clinical value for osteoporotic bone repair.

This paper considers the flexible job-shop scheduling problem with stochastic processing times. Contrary to the classical criteria in the literature used to deal with random parameters, the probability of the makespan to be smaller than a predefined value, called makespan service level, is maximized. A tabu search approach combined with a Monte Carlo sampling method is proposed. Computational experiments are conducted on extended versions of benchmark instances, including the probabilistic description of random parameters. The numerical results illustrate the impact of key characteristics of the proposed approach.

This is the accepted manuscript version of the work published in its final form as Fernandez, M. A. G., Marllon Nascimento de Oliveira., Zanetti, A., Schwertz, G., Cossy, J., & Amara, Z. (2021). Photochemical Hydrothiolation of Amorphadiene and Formal Synthesis of Artemisinin via a Pummerer Rearrangement.Organic Letters,23(15), 5593-5598. https://doi.org/10.1021/acs.orglett.1c00636 Deposited byshareyourpaper.organdopenaccessbutton.org. We've taken reasonable steps to ensure this content doesn't violate copyright. However, if you think it does you can request a takedown by emailinghelp@openaccessbutton.org.

This is the accepted manuscript version of the work published in its final form as Zanetti, A., Schwertz, G., Marllon Nascimento de Oliveira., Fernandez, M. A. G., Amara, Z., & Cossy, J. (2021). Palladium-Catalyzed Regioselective Allylic Oxidation of Amorphadiene, a Precursor of Artemisinin.The Journal of Organic Chemistry,86(11), 7603-7608. https://doi.org/10.1021/acs.joc.1c00653 Deposited byshareyourpaper.organdopenaccessbutton.org. We've taken reasonable steps to ensure this content doesn't violate copyright. However, if you think it does you can request a takedown by emailinghelp@openaccessbutton.org.

This study investigated the mobility and availability of Cd, Pb, and As pollution in the sediments of the Xijiang River Basin, China. The speciation analysis and ecological risk assessment of Cd, Pb, As in 21 sediment samples from the Xijiang River basin were studied by the sequential extraction technique, the enrichment factor (EF), the geo-accumulation index (Igeo), the potential ecological risk index (RI), the potential ecological risk factor (Eri), the risk assessment code (RAC), and the modified potential ecological risk index (MRI) assessment method. Metal speciation analysis indicated that the exchangeable and carbonate fraction were the primary binding phase for Cd in the sediment. However, the residual fraction was the major host for Pb and As. The Cd, Pb, and As speciation were highly correlated with Mn, organic matter (OM), carbonate (Carb), and pH. The RAC and MRI results showed that the mobility and availability of Cd, Pb, and As in the sediment followed the order of Cd > As > Pb. The higher mobility of Cd posed an elevated environmental risk. Moreover, it was found that the Diaojiang River had high ecological risk levels. Principal component analysis (PCA) and redundancy analysis (RDA) revealed that the mining industry mainly contributed to the enrichment of Cd, Pb, and As. This study provides a better understanding to predict and possibly find ways to control pollution of Cd, Pb, and As in sediments of such basins.

The coprecipitation and subsequent aging of Fe(III)-As(III)-As(V)-SO

Blunt thoracic aortic injury (BTAI) is the second leading cause of death from blunt trauma. In the present study, we aimed to determine the outcomes of medical management (MM) for BTAI. We hypothesized from the results of several previously reported studies, that patients with a minimal aortic injury (BTAI grades 1 and 2) could safely be treated with definitive MM alone.The Aortic Trauma Foundation international prospective multicenter registry was used to examine the demographics, injury characteristics, management, and outcomes of patients with BTAI. We analyzed a subset of patients for whom MM was initiated as definitive therapy.From November 2016 to April 2020, 432 patients (median age, 41 years; 76% male; median injury severity score, 34) with BTAI (Society for Vascular Surgery grade 1, 23.6%; grade 2, 14.4%; grade 3, 51.2%; grade 4, 10.9%) were evaluated. Of the 432 patients, 245 (57%) had received MM in the initial period and 114 (26.4%) had received MM as the planned definitive therapy (grade 1, 59.6%; grade 2, 23.7%; grade 3, 15.8%; grade 4, 0.9%). The most common mechanism of BTAI was a motor vehicle collision (60.4%). Hypotension was present on arrival in 74 patients (17.2%). Continuous titratable infusion of antihypertensive medication was used for 49.1%, followed by intermittent bolus administration (29.8%), with beta-blockers (74.6%) the most common agent used. Treatments were targeted to a goal systolic blood pressure for 83.3%, most often to a target goal systolic blood pressure120 mm Hg (66.3%). The MM goals based on blood pressure control were attained in 64.0% (73 of 114). Twelve patients (10.5%; grade 1, 1; grade 2, 0; grade 3, 10; grade 4, 1) had required subsequent intervention after MM. Eleven patients (9.6%) had undergone thoracic endovascular aortic repair and one (0.9%) had required open repair for a grade 4 injury. The overall in-hospital mortality for patients selected for definitive MM was 7.9%. No aortic-related deaths had occurred in the patients receiving definitive MM.Approximately one in four patients with BTAI will receive MM as definitive therapy. The variation in the pharmacologic therapies used is considerable. MM for patients with minimal aortic injury (BTAI grades 1 and 2) is safe and effective, with a low overall intervention rate and no aortic-related deaths. These findings support the use of definitive MM for grade 2 BTAI.

We report in this paper a new crystal-chemical study of synthetic basic ferric sulfate FeOHSO4. The structure solution performed by the Endeavour program, from new X-ray powder diffraction (XRPD) data, indicated that the correct space group of the monoclinic polytype of FeOHSO4 is C2/c. Selected Area Electron Diffraction (SAED) patterns are also consistent with this structure solution. The arrangement of Fe and S atoms, based on linear chains of Fe3+ octahedra cross-linked by SO4 tetrahedra, corresponds to that of the order/disorder (OD) family. The positions of the hydrogen atoms were located based on DFT calculations. IR and Raman spectra are presented and discussed according to this new structure model. The decomposition of FeOHSO4 during heating was further investigated by means of variable temperature XRPD, thermogravimetry, and differential thermal analysis as well as IR and Raman spectroscopies.

International audience; A formal synthesis of artemisinin starting from amorphadiene is described. This new route relies on the development of a catalytic chemo-and diastereoselective hydrosilylation. The practicability of this method is demonstrated by converting amorphadiene to dihydroartemisinic aldehyde using a one-pot hydrosilylation/oxidation sequence, minimizing the number of purifications and maximizing the productivity through a practical one-pot procedure. In addition, this approach can be coupled with a crystallization-induced diastereoselective transformation (CIDT) to enhance the optical purity of the key target intermediate, dihydroartemisinic aldehyde.

The biotic or abiotic reduction of nano-crystalline 2-line ferrihydrite (2-line FH) into more thermodynamically stable phases such as lepidocrocite-LP, goethite-GT, magnetite-MG, and hematite-HT plays an important role in the geochemical cycling of elements and nutrients in aqueous systems. In our study, we employed the use of

The trace element of As and Sb have resulted in serious threats to ecological sustainability and human health in the Xijiang River basin, China. The geoaccumulation index (I

Support of somatic growth is a fundamental requirement of tissue-engineered valves. However, efforts thus far have been unable to maintain this support long term. A key event that will determine the valve's long-term success is the extent to which healthy host tissue remodeling can occur on the valve soon after implantation. The construct's phenotypic-status plays a critical role in accelerating tissue remodeling and engineered valve integration with the host via chemotaxis. In the current study, human bone-marrow-derived mesenchymal stem cells were utilized to seed synthetic, biodegradable scaffolds for a period of 8 days in rotisserie culture. Subsequently, cell-seeded scaffolds were exposed to physiologically relevant oscillatory shear stresses (overall mean, time-averaged shear stress, ~7.9 dynes/cm2; overall mean, oscillatory shear index, ~0.18) for an additional 2 weeks. The constructs were found to exhibit relatively augmented endothelial cell expression (CD31; compared to static controls) but concomitantly served to restrict the level of the activated smooth muscle phenotype (α-SMA) and also produced very low stem cell secretion levels of fibronectin (p < 0.05 compared to static and rotisserie controls). These findings suggest that fluid-induced oscillatory shear stresses alone are important in regulating a healthy valve phenotype of the engineered tissue matrix. Moreover, as solid stresses could lead to increased α-SMA levels, they should be excluded from conditioning during the culture process owing to their associated potential risks with pathological tissue remodeling. In conclusion, engineered valve tissues derived from mesenchymal stem cells revealed both a relatively robust valvular phenotype after exposure to physiologically relevant scales of oscillatory shear stress and may thereby serve to accelerate healthy valve tissue remodeling in the host post-implantation.

A novel method has been proposed to prepare an arsenate (As(V))-containing solution for scorodite formation using an arsenic (As) sulphide residue obtained from a Pb refinery. Preparation of the As(V) solution from the As sulphide residue included As oxidation leaching by alternating addition of a highly concentrated sodium hydroxide (c-NaOH 600 g/L) solution and hydrogen peroxide (H2O2) at 70 °C. This method gave an As leaching efficiency of up to 99% (total % recovery of As up to 90%), while at the same time, other metals could be recovered effectively (e.g., 95% Pb, 97% Cd, 90% Zn, and 96% Cu). Further oxidation and removal of the remaining arsenite (As(III)) in the leached filtrate by H2O2 indicated that the oxidation efficiency of oxidizing As(III) to As(V) was up to 99%. The As(V) solution produced by this process was suitable for As(V) fixation as scorodite. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the starting materials and output solids. The results showed that the major As phase in the As-containing compound of the initial As sulphide residue was As sulphide. Highly pure elemental sulphur (total % recovery of S up to 30%) was generated during the S(-II) elimination process, and the scorodite from the As(V) fixation process was highly crystalline. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray absorption near edge structure spectroscopy (XANES) were employed to characterize the intermediate filtrate of the process. The results showed that the intermediate filtrate was a multiphase mixture containing As(III), arsenate, sulphate, thio-arsenate, thio-sulphate and polysulphides (Sn2−). The produced scorodite showed good As stability in the TCLP and at pH 3 (0.47 mg/L), pH 5 (0.26 mg/L), and pH 7 (3.41 mg/L) in a 10-day short-term stability test.

A novel zerovalen-iron–biochar composite (nZVI/SBC) was synthesized by using FeCl3-laden sorghum straw biomass as the raw material via a facile one-step pyrolysis method without additional chemical reactions (e.g., by NaBH4 reduction or thermochemical reduction). The nZVI/SBC was successfully employed as an activator in phenol degradation by activated persulfate. XRD, SEM, N2 adsorption–desorption and atomic absorption spectrophotometry analysis showed that the nanosized Fe0 was the main component of the 4ZVI/SBC activator, which was a mesopore material with an optimal FeCl3·6H2O/biomass impregnation mass ratio of 2.7 g/g. The 4ZVI/SBC activator showed an efficient degradation of phenol (95.65% for 30 min at 25 °C) with a large specific surface area of 78.669 m2·g−1. The recovery of 4ZVI/SBC activator after the degradation reaction of phenol can be realized with the small amount of dissolved iron in the water. The 4ZVI/SBC activator facilitated the activation of persulfate to degrade phenol into non-toxic CO2 and H2O. The trend of Cl−, SO42− and NO3− affected the removal efficiency of phenol by using the 4ZVI/SBC activator in the following order: NO3− > SO42− > Cl−. The one-step synthesis of the nanosized zerovalent-iron–biochar composite was feasible and may be applied as an effective strategy for controlling organic waste (e.g. phenol) by waste biomass.

Gypsum is a high-volume by-product of hydrometallurgical arsenic removal using the Fe(III)-As(V) coprecipitation technique. However, the role of gypsum in As fixation during the Fe(III)-As(V) coprecipitation process and the potential risk of As-bearing gypsum are still not well known. In this study, the fixation of As by gypsum was quantitatively investigated as a function of the initial As and H2SO4 concentrations, Fe/As molar ratio, pH, and neutralization mode. Column leaching tests were also performed to evaluate the potential risk of Fe(III)-As(V) coprecipitates. The results showed that the gypsum isolated from Fe(III)-As(V) coprecipitates by ascorbic acid (VC) treatment could fix up to 4.5% of the total As in the system at pH 8 in fixed-pH mode. The gypsum produced in fixed-pH mode contained a significantly higher concentration of As than that produced in acid-alkaline neutralization mode. The column leaching tests showed that a faster leaching rate could enhance the release of As from Fe(III)-As(V) coprecipitates. It seems that the presence of gypsum could prevent the release of As from Fe(III)-As(V) coprecipitates. Linear combination fits of the As and Fe K-edge XANES spectra suggested that As was likely to occur as adsorbed As and yukonite in VC-isolated gypsum.

Two-line ferrihydrite (Fh), ubiquitous in soils, groundwater, and aquatic sediments, may serve as an important sink for sequestering trace metals, metalloids, and organic matter via adsorption/coprecipitation due to its high surface area and reactivity. Although considerable attention has been paid to the transformation process of this thermodynamically metastable solid, little is known about the transformation products, the crystallization rates, or the transformation routes of two-line Fh in sulfate- and calcium-rich environments. This work systematically investigates the transformation of 2-line ferrihydrite produced by using different neutralization reagents (CaO vs NaOH) at different pHs (4 and 8), temperatures (25 °C, 40 °C, and 80 °C), and media (sulfate vs nitrate). X-ray diffraction, Raman, Fourier transform infrared spectroscopy, and chemical extraction were employed to characterize the transformed solids as well as the crystallization rate of 2-line Fh. The results show that the crystallization...

The coprecipitation and subsequent aging of Fe(III)-As(III)-As(V)-SO42− play an important role in controlling As behavior in acidic systems, such as acid mine drainage and hydrometallurgical acid waste. In this study, we investigated the redistribution and transformation of As in the Fe(III)-As(III)-As(V)-SO42− system (As(III)/As(V) ≈ 1) at different Fe/As molar ratios (i.e., 0.25, 0.5, and 1) and pH (1.2 and 1.8) at 60 °C. The results showed that As(III) and SO42− can be incorporated into the amorphous ferric arsenate and scorodite host phases by forming a Fe(AsO4)x(AsO3)y(SO4)z solid solution. As(III) contents in the freshly coprecipitated solids increased with pH and initial As(III) concentrations. During aging process, As(III) contents in the solid products with Fe/As molar ratios of 0.5 and 1 increased with aging time at pH 1.8. In contrast, As(III) was gradually expelled from aging products with aging time at pH 1.2, regardless of Fe/As molar ratio. X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and Raman spectroscopy characterization results showed that an As(III)-SO42−-doped scorodite was formed at Fe/As molar ratio ≤0.5 during the aging process. It was also found that As(III) had an inhibitory effect on the transformation of poorly crystalline ferric arsenate to scorodite. The present study may have important implications for understanding the geochemical cycle of As, Fe, and SO42− in acidic solutions and give further understanding on the mechanisms involved in As removal and fixation in hydrometallurgical unit operations.