Odstraňování rtuti z kyselých roztoků chloridu rtuťnatého sorbenty připravenými katalyzovanou vulkanizací rostlinných olejů

Mercury is a metallic element, dangerous and toxic for the environment. Presently, the incineration of municipal solid waste (MSW) belongs to important sources of Hg emissions. Methods of conversion of metallic mercury and mercury compounds from soluble and toxic forms into water insoluble/non-toxic form (HgS) are sought after. Gaseous HCl and a significant part of HgCl2 vapors present in flue gas from incineration of MSW can be removed there by absorption in hot water. Efficiencies of Hg2+ removal from acidic water solutions by means of sorbents prepared by catalyzed reaction of sulfur with vegetable oils (inverse vulcanization) were studied. These kinds of sorbents were tested and found to be exploitable for selective removal of mercury ions from aqueous solutions, particularly from acidic solutions containing HCl at higher temperatures (50–75 °C). Presence of relatively high concentrations of salts of some other metallic elements (Fe, Zn, Ca) had only very small effects on Hg-sorption. Mercury adsorbed on such sorbents converts relatively quickly into a non-toxic form (HgS). Reactive sulfides and SH‑groups present on the surface of the sorbent particles contribute to a faster sorption of mercury and its conversion to HgS. Leaching of zinc from the catalyst (Zn‑diethyldithiocarbamate) present in the vulcanized sorbents is negligible at neutral conditions and small (about 10 %) at acidic conditions (pH = 1.5).

Exploring the nexus between GSCM and organisational culture: insights on the role of supply chain integration

Purpose This paper aims to investigate the interlinks between different forms of organisational culture (OC), supply chain (SC) integration, green supply chain management (GSCM) practices. It adopts a green human resource management (GHRM) perspective on knowledge, skills and abilities (KSAs) dynamics to shed light on the drivers that facilitate the implementation of green practices along with the SC. Design/methodology/approach The study adopts a quantitative approach through a survey administered to 381 formally appointed Italian SC managers, combining two methodological approaches, namely, the collection of self-reported information regarding the perceived OC, SC integration and GSCM practices in respondent’s organisations and an experimental design aimed at collecting the expected links between GHRM and the firm’s performance in different neutral conditions. Findings The results highlight that it is necessary to observe the disaggregated paths that link the different types of OC and dimensions of SC integration to benefit from a path-specific rationale for each GSCM practice. Insights on how different dimensions of SC integration mediate the relations between different OCs and GSCM practices, in the light of the role played by KSAs in the pursuit of the firm’s sustainable performance, reveal the relative importance of establishing strong relationships with customers and among the actors involved in the production process. Practical implications This paper provides directions for collaboration among SC and HR managers in the pursuit of GSCM. Originality/value This paper adopts an original classification of both OC and SC integration, identifying the existence of previously unrevealed nexuses. Additionally, it provides an original contribution to the extant literature by separately analysing each GSCM practice and, thus, offering detailed insights on their drivers.

Boosting Heterogeneous Fenton Reactions for Degrading Organic Dyes via Photothermal Effect under Neutral Conditions

Although heterogeneous Fenton reaction has demonstrated great promise in the remediation of refractory organic pollutants, its widespread application is still limited by the insufficient degradation performance under neutral conditions. Here,...

Bap-Independent Biofilm Formation in Staphylococcus xylosus

The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in Staphylococcus aureus V329 and has been predicted as important for other species as well. Although Bap orthologs are also present in most S. xylosus strains, their contribution to biofilm formation has not yet been demonstrated. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in S. xylosus and the motif structure of two biofilm-forming S. xylosus strains TMW 2.1023 and TMW 2.1523 was compared to Bap of S. aureus V329. We found that despite an identical structural arrangement into four regions, Bap from S. xylosus differs in key factors to Bap of S. aureus, i.e., isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of bap had no effect on aggregation behavior of selected S. xylosus strains and biofilm formation was unaffected (TMW 2.1023) or at best slightly reduced under neutral conditions (TMW 2.1523). Further, we could not observe any typical characteristics of a S. aureus Bap-positive phenotype such as functional impairment by calcium addition and rough colony morphology on congo red agar (CRA). A dominating role of Bap in cell aggregation and biofilm formation as reported mainly for S. aureus V329 was not observed. In contrast, this work demonstrates that functions of S. aureus Bap cannot easily be extrapolated to S. xylosus Bap, which appears as non-essential for biofilm formation in this species. We therefore suggest that biofilm formation in S. xylosus follows different and multifactorial mechanisms.

Lactate regulation of activation in CD8+ T cells

CD8+ T cells infiltrate virtually every tissue to find and destroy infected or mutated cells. They often traverse varying oxygen levels and nutrient-deprived microenvironments. High glycolytic activity in tissues can result in extended exposure of cytotoxic T cells to the metabolite lactate. Lactate can be immunosuppressive, at least in part due to its association with tissue acidosis. We show here that the lactate anion is well tolerated by CD8+ T cells in pH neutral conditions. We describe how lactate is taken up by activated CD8+ T cells and is capable of displacing glucose as a carbon source. Activation in the presence of a pH neutral form of lactate significantly alters the CD8+ T cell transcriptome, including the expression of key effector differentiation markers such as granzyme B and interferon-gamma. Our studies reveal the novel metabolic features of lactate utilization by activated CD8+ T cells, and highlight the importance of lactate in shaping the differentiation and activity of cytotoxic T cells.

Influence of Sex and Knee Joint Rotation on Patellofemoral Joint Stress through a Mathematical Modelling Study

Background: Females are two times as likely to experience patellofemoral pain syndrome (PFPS) than males; however, the reason for this sex difference remains unclear. Patellofemoral joint (PFJ) stress is believed to contribute to PFPS alterations through knee joint rotation alignment, but the influence of knee joint rotation conditions on PFJ stress is unclear. We aimed to investigate the influence of sex and knee joint rotation alignment on PFJ stress. Methods: Simulation ranges were set to knee joint flexion angles of 10°-45° (common to both sexes) and extension moments of 0-240 Nm (males) and 0-220 Nm (females). The quadriceps force and effective lever arm length at the quadriceps muscle were determined as a function of the knee joint flexion angle and extension moment. The PFJ contact area, which is specific to sex, and knee joint rotation was calculated from cadaver data, and PFJ stress was estimated. Results: In all knee joint rotation conditions, PFJ stress was higher in females than in males. Additionally, PFJ stress in males and females was the largest under neutral conditions compared with other rotation conditions. Conclusion: The results may be useful for understanding the underlying mechanisms contributing to the differences in PFPS in males and females.

Acidic Microenvironment Determines Antibiotic Susceptibility and Biofilm Formation of Pseudomonas aeruginosa

Pseudomonas aeruginosa is the most prevalent bacterial species that contribute to cystic fibrosis (CF) respiratory failure. The impaired function of CF transmembrane conductance regulator leads to abnormal epithelial Cl–/HCO3– transport and acidification of airway surface liquid. However, it remains unclear why the CF lung is most commonly infected by Pseudomonas aeruginosa versus other pathogens. We carried out studies to investigate if lower pH helps Pseudomonas aeruginosa adapt and thrive in the CF-like acidic lung environment. Our results revealed that Pseudomonas aeruginosa generally forms more biofilm, induces antibiotic resistance faster in acidic conditions, and can be reversed by returning the acidic environment to physiologically neutral conditions. Pseudomonas aeruginosa appears to be highly adaptive to the CF-like acidic pH environment. By studying the effects of an acidic environment on bacterial response, we may provide a new therapeutic option in preventing chronic Pseudomonas aeruginosa infection and colonization.

Is Acquired Disgust More Difficult to Extinguish Than Acquired Fear? an Event-Related Potential Study

This study used the classical conditioned acquisition and extinction paradigm to compare which of the two emotions, acquired disgust and acquired fear, was more difficult to extinguish, based on behavioral assessments and the event-related potential (ERP) technique. Behavioral assessments revealed that, following successful conditioned extinction, acquired disgust was more difficult to extinguish. The ERP results showed that, at the early stage of P1, the amplitude of conditioned fear was significantly smaller than that of conditioned disgust, and both were significantly different from the amplitude under neutral conditions; at the middle stage of N2, the difference between the amplitudes of conditioned disgust and conditioned fear disappeared, but they were still significantly different from the amplitudes of conditioned neutral stimuli; at the late stage of P3, the difference between conditioned disgust and conditioned neutral stimuli disappeared, but the difference between conditioned fear and neutral stimuli remained, suggesting that acquired fear was more difficult to extinguish than acquired disgust in terms of how the brain works.

Photo-induced catalytic halopyridylation of alkenes

The Mizoroki-Heck reaction and its reductive analogue are staples of organic synthesis, but the ensuing products often lack a chemical handle for further transformation. Here we report an atom-economical cross-coupling of halopyridines and unactivated alkenes under photoredox catalysis to afford a series of alkene halopyridylation products. This protocol with mild and redox neutral conditions contributes broad substrate scope. As a complement to conventional Heck-type reaction, this radical process avoids the involvement of β-H elimination and thus useful pyridyl and halide groups could be simultaneously and regioselectively incorporated onto alkenes. The success depends on TFA-promoted domino photocatalytic oxidative quenching activation and radical-polar crossover pathway. Plausible mechanism is proposed based on mechanistic investigations. Moreover, the reserved C − X bonds of these products are beneficial for performing further synthetic elaborations.

Bioremediation of Uranium- and Nitrate-Contaminated Groundwater after the In Situ Leach Mining of Uranium

Uranium and nitrate are common groundwater pollutants near in situ leach uranium mines. However, we still lack techniques that can simultaneously immobilize uranium and reduce nitrate using a single bacterial species. In this study, the potential of simultaneous uranium immobilization and nitrate reduction by a single AFODN (anaerobic Fe(II) oxidizing denitrifier), Clostridium sp. PXL2, was investigated. Clostridium sp. PXL2 showed tolerance to U(VI) concentrations varying from 4.2 µM to 42 µM. The U(VI) immobilization and nitrate reduction rates in groundwater samples inoculated with this bacterium reached up to 75.1% and 55.7%, respectively, under neutral conditions. Exposure to oxidation conditions led to further U(VI) removal but did not show any noticeable effect on nitrate reduction. The U(VI) immobilization rate reached up to 85% with an increased Fe(II) initial concentration, but this inhibited nitrate reduction. SEM (scanning electron microscopy) coupled with EDS (energy dispersive spectroscopy) showed that the U(VI) immobilization was mainly due to sorption to amorphous ferric oxides. U(VI) and nitrate bioremediation by AFODNs, including Clostridium sp. PXL2, may provide a promising method for the treatment of uranium- and nitrate-contaminated groundwater after the in situ leach mining of uranium.