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Morrison Watts posted an update 17 days ago
Although many other factors determine the choice of filter type for PM analyses, the present study is an important contribution to knowledge of assessing the suitability of different types of filter material for specific measurements.There is increasing interest in the development of noble metal separation/recovery processes, especially for applications to “urban mining”. Common separation/recovery processes for noble metals use a solvent (liquid-liquid) extraction technique in hydrometallurgy. However, these processes are time-consuming and not environmentally friendly, because they use organic solvents for sequential metal ion extractions. Electrowinning is an alternative approach for selective metal precipitation that involves controlling the redox potentials of electrodes but requires specialized equipment and generates hydrogen as a byproduct at the cathode surface under dilute conditions. In the present study, we investigated selective gold recovery from a homogenous aqueous solution containing a mixture of dilute HAuCl4 and H2PtCl6 (5.0 × 10-5 M each) and aromatic amino acid-containing peptides (2.0 × 10-4 M each). Gold selectivity was determined by analyzing the compositions of the solids and supernatants obtained from the reaction mixtures. find more A much higher gold selectivity (gold/platinum (Au/Pt) atomic ratio = 7.5) was obtained using an anthracene-containing peptide compared to peptides containing one or two naphthalene ring(s). Our proposed approach is applicable to the sequential separation of several noble metal ions, such as Au, palladium (Pd), Pt, iridium (Ir) and rhodium (Rh), and simply requires developing aromatics suitable for each noble metal of interest.Nanofibrous materials produced by electrospinning processes have potential advantages in tissue engineering because of their biocompatibility, biodegradability, biomimetic architecture, and excellent mechanical properties. The aim of the current work is to study the influence of the electron beam on the poly L-lactide acid/ carboxy-methyl starch/β-tricalcium phosphate (PLLA/CMS/β-TCP) composite nanofibers for potential applications as bone-tissue scaffolds. The composite nanofibers were prepared by electrospinning in the combination of 5% v/v carboxy-methyl starch (CMS) and 0.25 wt% of β-TCP with the PLLA as a matrix component. The composites nanofibers were exposed under 5, 30, and 100 kGy of irradiation dose. The electron-beam irradiation showed no morphological damage to the fibers, and slight reduction in the water-contact angle and mechanical strength at the higher-irradiation doses. The chain scission was found to be a dominant effect; the higher doses of electron-beam irradiation thus increased the in vitro degradation rate of the composite nanofibers. The chemical interaction due to irradiation was indicated by the Fourier transform infrared (FTIR) spectrum and thermal behavior was investigated by a differential scanning calorimeter (DSC). The results showed that the electron-beam-induced poly L-lactide acid/carboxy-methyl starch/β-tricalcium phosphate (PLLA/CMS/β-TCP) composite nanofibers may have great potential for bone-tissue engineering.Hypoxia is a common hallmark of solid tumors and is associated with aggressiveness, metastasis and poor outcome. Cancer cells under hypoxia undergo changes in metabolism and there is an intense crosstalk between cancer cells and cells from the tumor microenvironment. This crosstalk is facilitated by small extracellular vesicles (sEVs; diameter between 30 and 200 nm), including exosomes and microvesicles, which carry a cargo of proteins, mRNA, ncRNA and other biological molecules. Hypoxia is known to increase secretion of sEVs and has an impact on the composition of the cargo. This sEV-mediated crosstalk ultimately leads to various biological effects in the proximal tumor microenvironment but also at distant, future metastatic sites. In this review, we discuss the changes induced by hypoxia on sEV secretion and their cargo as well as their effects on the behavior and metabolism of cancer cells, the tumor microenvironment and metastatic events.Cascading disasters progress from one hazard event to a range of interconnected events and impacts, with often devastating consequences. Rain-related cascading disasters are a particularly frequent form of cascading disasters in many parts of the world, and they are likely to become even more frequent due to climate change and accelerating coastal development, among other issues. (1) Background The current literature review extended previous reviews of documented progressions from one natural hazard event to another, by focusing on linkages between rain-related natural hazard triggers and infrastructural impacts. (2) Methods A wide range of case studies were reviewed using a systematic literature review protocol. The review quality was enhanced by only including case studies that detailed mechanisms that have led to infrastructural impacts, and which had been published in high-quality academic journals. (3) Results A sum of 71 articles, concerning 99 case studies of rain-related disasters, were fully reviewed. Twenty-five distinct mechanisms were identified, as the foundation for a matrix running between five different natural hazards and eight types of infrastructural impacts. (4) Conclusion Relatively complex quantitative methods are needed to generate locality-specific, cascading disaster likelihoods and scenarios. Appropriate methods can leverage the current matrix to structure both Delphi-based approaches and network analysis using longitudinal data.Metal-organic frameworks (MOFs) as additives in mixed matrix membranes (MMMs) for gas separation have gained significant attention over the past decades. Many design parameters have been investigated for MOF based MMMs, but the spatial distribution of the MOF throughout MMMs lacks investigation. Therefore, magnetically aligned and enriched pathways of zeolitic imidazolate framework 8 (ZIF-8) in Matrimid MMMs were synthesized and investigated by means of their N2 and CO2 permeability. Magnetic ZIF-8 (m-ZIF-8) was synthesized by incorporating Fe3O4 in the ZIF-8 structure. The presence of Fe3O4 in m-ZIF-8 showed a decrease in surface area and N2 and CO2 uptake, with respect to pure ZIF-8. Alignment of m-ZIF-8 in Matrimid showed the presence of enriched pathways of m-ZIF-8 through the MMMs. At 10 wt.% m-ZIF-8 incorporation, no effect of alignment was observed for the N2 and CO2 permeability, which was ascribed anon-ideal tortuous alignment. However, alignment of 20 wt.% m-ZIF-8 in Matrimid showed to increase the CO2 diffusivity and permeability (19%) at 7 bar, while no loss in ideal selectivity was observed, with respect to homogeneously dispersed m-ZIF-8 membranes.