Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems

Marmatite and bornite are commonly associated together in nature, and their interactions in an acidic environment are vital for both (bio)hydrometallurgy and acid mine drainage (AMD) production. In this work, dissolution experiments (marmatite : bornite = 2 : 0, 3 : 1, 1 : 1, 1 : 3 and 0 : 2) accompanied by analytic techniques such as electrochemical methods, Raman spectroscopy and synchrotron radiation-XRD (SR-XRD) were utilized to interpret the interactions between marmatite and bornite in acidic abiotic and biotic systems. The dissolution experiments showed that marmatite can significantly accelerate the oxidative dissolution of bornite, especially in the abiotic system. On the contrary, bornite inhibited the oxidative dissolution of marmatite when the percentage of bornite was high. Electrochemical measurements proved that the galvanic interactions between marmatite and bornite were slight and should not be the main cause for the interactions. Combined with the dissolution experiments, analytic techniques and previous references, it could be speculated that marmatite accelerated bornite dissolution mainly by providing an iron source, which acted as the energy source for microorganisms and oxidants. Bornite affected the dissolution of marmatite mainly by Cu²⁺ ions dissolving from bornite. Bornite inhibited the oxidative dissolution of marmatite mainly because a high Cu²⁺ concentration could significantly hinder marmatite dissolution. In addition, the formation of elemental sulfur or jarosite was also one important cause. Bornite intensified marmatite dissolution when the percentage of bornite or the Cu²⁺ concentration was extremely low and then, a synergic dissolution process occurred.

Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems.     

Patient-important activity and participation outcomes in clinical trials involving children with chronic conditions

Purpose

Children with chronic conditions experience medical issues over long-term periods of time which can have lasting emotional and social consequences impacting daily life and functioning. Activities and participation outcomes are needed in order to comprehensively assess child-important health in clinical trials. Our objective was to review the extent to which activity and participation outcomes are included in clinical trials of childhood chronic disease and to determine what trial characteristics are associated with their use.

Methods

A review of a large clinical trial registration database (clinicaltrials.gov) was conducted over the 2010 calendar year. The measures used to assess primary and secondary endpoints were coded according to the ICF classification system. Trial characteristics that might be associated with activity and participation outcome use such as sponsorship type, intervention type, health condition, whether the trial was focused on pediatric patients, phase of trial and sample size were also extracted and explored with univariable and multivariable regressions.

Results

Four hundred and ninety-nine trials met inclusion criteria, 495 of which had complete information about hypothesized predictors. Only 36 out of 495 trials included an activity and participation outcome as part of the trial evaluation process. Both univariable and multivariable regression models showed that non-drug trials and late phase of trial (phase IV) showed the strongest likelihood with whether a trial would include an activity and participation outcome.

Discussion

Most registered clinical trials for children with chronic or ongoing medical conditions do not include a comprehensive approach to health outcomes assessment, especially drug trials and early phase trials. Outcome measures in pediatric clinical trials are lagging relative to World Health Organization standards for comprehensive health evaluation.     

Induction of innate immunity by Aspergillus fumigatus cell wall polysaccharides is enhanced by the composite presentation of chitin and beta-glucan

Chitin and β-glucan are conserved throughout evolution in the fungal cell wall and are the most common polysaccharides in fungal species. Together, these two polysaccharides form a structural scaffold that is essential for the survival of the fungus. In the present study, we demonstrated that Aspergillus fumigatus alkali-insoluble cell wall fragments (AIF), composed of chitin linked covalently to β-glucan, induced enhanced immune responses when compared with individual cell wall polysaccharides. Intranasal administration of AIF induced eosinophil and neutrophil recruitment, chitinase activity, TNF-α and TSLP production in mice lungs. Selective destruction of chitin or β-glucan from AIF significantly reduced eosinophil and neutrophil recruitment as well as chitinase activity and cytokine expression by macrophages, indicating the synergistic effect of the cell wall polysaccharides when presented together as a composite PAMP. We also showed that these cell wall polysaccharides induced chitin-specific IgM in mouse serum. Our in vivo and in vitro data indicate that chitin and β-glucan play important roles in activating innate immunity when presented as composite cell wall PAMPs.     

Correction: Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems

Correction for ‘Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems’ by Yanjun Zhang et al., RSC Adv., 2019, 9, 26609–26618.

Hussnain Ahmed Janjua''s name was incorrectly spelled in the published article; the corrected author list is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Exploring the Relationship Between Changes in Weight and Utterances in an Online Weight Loss Forum: A Content and Correlational Analysis Study

BackgroundThere is increasing interest in the use of online forums as a component of eHealth weight loss interventions. Although the research is mixed on the utility of online forums in general, results suggest that there is promise to this, particularly if the systems can be designed well to support healthful interactions that foster weight loss and continued engagement.ObjectiveThe purpose of this study was to examine the relationship between the styles of utterances individuals make on an online weight loss forum and week-to-week fluctuations in weight. This analysis was conducted to generate hypotheses on possible strategies that could be used to improve the overall design of online support groups to facilitate more healthful interactions.MethodsA convenience sample of individuals using an online weight loss forum (N=4132) included data both on online forum use and weight check-in data. All interactions were coded utilizing the Linguistic Inquiry and Word Count (LIWC) system. Mixed model analyses were conducted to examine the relationship between these LIWC variables and weight over time.ResultsResults suggested that increased use of past-tense verbs (P=.05) and motion (P=.02) were associated with lower weekly weights whereas increased use of conjunctions (eg, and, but, whereas; P=.001) and exclusion words (eg, but, without, exclude; P=.07) were both associated with higher weight during the weeks when these utterances were used more.ConclusionsThese results provide some insights on the styles of interactions that appear to be associated with weight fluctuations. Future work should explore the stability of these findings and also explore possibilities for fostering these types of interactions more explicitly within online weight loss forums.     

Bioremediation of Textile Dye Procion Red Yellow by Using Pseudomonas fluorescens

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Dyes primarily present in effluents from textile industries are recalcitrant organic molecules with a complex...     

Pre-clinical pharmacokinetic and pharmacodynamic modelling study of 4-hydroxyisoleucine using validated ultra-performance liquid chromatography-tandem mass spectrometry

A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry-based method has been developed for the estimation of 4-hydroxyisoleucine (4-HI), a potent insulinotropic and hypolipidemic agent. The extraction of 4-HI from plasma was accomplished by the protein precipitation technique using l-isoleucine as an internal standard. The separation of analytes was achieved with a mobile phase consisting of acetonitrile and 0.1% formic acid in an isocratic flow system on a BEH Shield RP-18 column (150 mm × 2.1 mm, 1.7 μm). 4-HI and l-isoleucine were detected using an electrospray ionization (ESI) ion source, using multiple reaction monitoring (MRM) in positive ion mode. The precursor to product ion transitions of 4-HI and l-isoleucine were found at m/z values of 148.19 > 74.02 and 132.17 > 69.04, respectively. As per the guidelines for bioanalytical methods, all validation parameter results were within the acceptable range. The method exhibited a robust and reproducible linearity range of 1–5000 ng mL⁻¹ with a coefficient of regression of 0.9999. The method was successfully applied for the estimation of pharmacokinetic parameters after oral administration of 4-HI (10 mg kg⁻¹) in Wistar rats, by using Thoth Pro (version: 4.3) software. Herein, the two-compartment model was statistically fitted based on AIC and SBC values for evaluation of the pharmacokinetic parameters of 4-HI. Pharmacodynamic studies were also performed by measuring the levels of triglyceride and total cholesterol, and showed that the pharmacokinetic and pharmacodynamic data of 4-HI correlated with each other.

A reliable and sensitive UPLC-MS/MS based method has been developed for the estimation of 4-hydroxyisoleucine, a potent insulinotropic and hypolipidemic agent.     

Heat Source Modeling and Residual Stress Analysis for Metal Directed Energy Deposition Additive Manufacturing

The advancement in additive manufacturing encourages the development of simplified tools for deep and swift research of the technology. Several approaches were developed to reduce the complexity of multi-track modeling for additive manufacturing. In the present work, a simple heat source model called concentrated heat source was evaluated for single- and multi-track deposition for directed energy deposition. The concentrated heat source model was compared with the widely accepted Goldak heat source model. The concentrated heat source does not require melt pool dimension measurement for thermal model simulation. Thus, it reduces the considerable time for preprocessing. The shape of the melt pool and temperature contour around the heat source was analyzed for single-track deposition. A good agreement was noticed for the concentrated heat source model melt pool, with an experimentally determined melt pool, using an optical microscope. Two heat source models were applied to multi-track 3D solid structure thermo-mechanical simulation. The results of the two models, for thermal history and residual stress, were compared with experimentally determined data. A good agreement was found for both models. The concentrated heat source model reported less than the half the computational time required for the Goldak model. The validated model, for 3D solid structure thermo-mechanical simulation, was used to analyze thermal stress evolution during the deposition process. The material deposition on the base plate at room temperature results in lower peak temperatures in the layers near the base plate. Consequently, the higher thermal stress in the layers near the base plate was found, compared to the upper layers during the deposition process.