This study evaluates the ability of a choline chloride:ethylene glycol-based deep eutectic solvent (DES) to dissolve lithium cobalt oxide (LCO) which is used as a cathode active material in Li-ion batteries. Both a commercial powder and spent cathodes have been used. It was demonstrated that if HCl is added in a small proportion, a rapid and efficient LCO dissolution can be achieved.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
July 2023
The resistance of the emerging human pathogen Stenotrophomonas maltophilia to tetracycline antibiotics mainly depends on multidrug efflux pumps and ribosomal protection enzymes. However, the genomes of several strains of this Gram-negative bacterium code for a FAD-dependent monooxygenase (SmTetX) homologous to tetracycline destructases. This protein was recombinantly produced and its structure and function were investigated.
View Article and Find Full Text PDFHealth conditions contribute significantly to patients' quality of life. Healthcare infrastructure and healthcare services, including their accessibility, belong to objective factors influencing their perception of their health. The growing disparity between supply and demand for specialized inpatient facilities due to the aging population calls for new solutions, including eHealth technologies.
View Article and Find Full Text PDFS1 nuclease from Aspergillus oryzae is a single-strand-specific nuclease from the S1/P1 family that is utilized in biochemistry and biotechnology. S1 nuclease is active on both RNA and DNA but with differing catalytic efficiencies. This study clarifies its catalytic properties using a thorough comparison of differences in the binding of RNA and DNA in the active site of S1 nuclease based on X-ray structures, including two newly solved complexes of S1 nuclease with the products of RNA cleavage at atomic resolution.
View Article and Find Full Text PDFFucosylated compounds are abundantly present in nature and are associated with many biological processes, therefore carrying great potential for use in medicine and biotechnology. Efficient ways to modify fucosylated compounds are still being developed. Promising results are provided by glycosyl hydrolases with transglycosylating activities, such as α-l-fucosidase isoenzyme 2 from Paenibacillus thiaminolyticus (family GH151 of Carbohydrate-Active enZYmes).
View Article and Find Full Text PDFCDKL5 deficiency disorder (CDD) is an independent clinical entity associated with early-onset encephalopathy, which is often considered the type of epileptic encephalopathy with CDKL5 mutation also found in children diagnosed with early-onset seizure (Hanefeld) type of Rett syndrome, epileptic spasms, West syndrome, Lennox-Gastaut syndrome, or autism. Since early seizure onset is a prominent feature, in this study, a cohort of 54 unrelated patients consisting of 26 males and 28 females was selected for CDKL5 screening, with seizures presented before 12 months of age being the only clinical criterion. Five patients were found to have pathogenic or likely pathogenic variants in CDKL5 while 1 was found to have a variant of uncertain significance (p.
View Article and Find Full Text PDFThe synchrotron facilities used in collecting the data for the article by Švecová et al. [(2021), Acta Cryst. D77, 755-775] are acknowledged.
View Article and Find Full Text PDFAn acidic aqueous biphasic system (AcABS) presenting a desired and reversible phase transition with HNO concentration and temperature was developed herein as an integrated platform for metal separation. The simple, economical, and fully incinerable (C,H,O,N) AcABS composed of tetrabutylammonium nitrate ([N ][NO ])+HNO +H O was characterized and presented an excellent selectivity towards Ce against other rare earth elements and transition metals from both synthetic solutions and nickel metal hydride (NiMH) battery leachates. The acid-driven self-assembly of AcABS bridges the gap between traditional ABS and liquid-liquid extraction whilst retaining their advantageous qualities, including compatibility with highly acidic solutions, water as the primary system component, the avoidance of organic diluents, rapid mass transfer, and the potential integration of the leaching and separation steps.
View Article and Find Full Text PDFIn this work, the important role played by metal ions such as Fe(ii/iii), Cr(iii) and Ni(ii) in the formation and binodal behaviour of aqueous biphasic systems (ABS) composed of HCl and the ionic liquid, [P44414]Cl, or the polymer, PEG-600, is investigated. The concentration of metal ions used in this work exceeds several g L-1 for an industrial foreseen application. Experiments have also been carried out by varying the concentration of metal ions at different temperatures.
View Article and Find Full Text PDFCellulose from cotton fibers was functionalized through a dissolution-regeneration process with phosphonate-based ionic liquids (ILs): 1,3-dimethylimidazolium methylphosphonate [DIMIM][(MeO)(H)PO] and 1-ethyl-3-methylimidazolium methylphoshonate [EMIM][(MeO)(H)PO]. The chemical modification of cellulose occurred through a transesterification reaction between the methyl phosphonate function of ILs and the primary alcohol functions of cellulose. The resulting cellulose structure and the amount of grafted phosphorus were then investigated by X-ray diffraction, ICP-AES, and ¹³C and ³¹P NMR spectroscopy.
View Article and Find Full Text PDFAlmost 500 municipal solid waste incineration plants in the EU, Norway and Switzerland generate about 17.6 Mt/a of incinerator bottom ash (IBA). IBA contains minerals and metals.
View Article and Find Full Text PDFUnlike any protein studied so far, the active site of bilirubin oxidase from Myrothecium verrucaria contains a unique type of covalent link between tryptophan and histidine side chains. The role of this post-translational modification in substrate binding and oxidation is not sufficiently understood. Our structural and mutational studies provide evidence that this Trp396-His398 adduct modifies T1 copper coordination and is an important part of the substrate binding and oxidation site.
View Article and Find Full Text PDFIn this work, the aqueous speciation of Rh(III) in chloride medium was investigated by UV-vis spectroscopy for ligand to metal ratios R = (Cl)/(Rh) ranging from 300 to 5000, at fixed Rh concentration (2.4 × 10 M). Under the chemical conditions of this work, no time evolution was observed, which allows for the fitting of the UV-vis data by Principal Component Analysis (PCA) and Multi-Curve Resolution (MCR).
View Article and Find Full Text PDFIonic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated exceptional performance in bioseparation processes. However, IL-based ABS are of limited interest for metal extraction as most metals are not stable in their neutral or alkaline pH conditions. In the quest for better extraction systems for metals, the development of IL-based ABS with highly acidic solutions (AcABS), induced by the mixture of a hydrophilic IL ([P44414]Cl), a mineral acid (HCl, HNO3 or H2SO4) and water, opens new possibilities.
View Article and Find Full Text PDFThe extraction of Pd(ii) and Rh(iii) from acidic solutions containing between 1 and 8 M HCl towards three ionic liquids, namely [P][Cl], [P][Br] and [P][DCA], based on the trihexyltetradecylphosphonium cation ([P]) and chloride, bromide or dicyanamide (DCA) anions, respectively, is reported. Extraction of Pd(ii) is quantitative up to 6 M HCl (D > 3000). A value of 258 for the distribution coefficient of Rh(iii) extracted from 1 M HCl towards [P][Br] is also reported.
View Article and Find Full Text PDFAn investigation on a process designed for separating Pt(IV) and Pd(II) dissolved in acidic aqueous solution containing HCl using two ionic liquids, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([OMIM][NTf2]) and trihexyltetradecylphosphonium bromide (Cyphos 102), is presented. To this end, the single extraction of platinum in [OMIM][NTf2] has been investigated as a function of the initial concentration of Pt(IV) ions dissolved in 1 M HCl. The distribution coefficient for Pt(IV), present in water as a PtCl6(2-) anion, decreases with the concentration of Pt(IV).
View Article and Find Full Text PDFThe present work deals with the modeling of selenium oxyanion (selenite/selenate) retention in TiO2 rutile porous media. A set of chemical interactions was elaborated from spectroscopic measurements and adsorption experiments in batch and column reactors, and a model of transient transport of the selenium species through laboratory column was developed. The adsorption model considered that both forms of selenium (Se) compete for the same sorption sites, hydroxyl groups, allowing taking into account a competitive adsorption.
View Article and Find Full Text PDFSelenium is a known toxic element released in the environment by anthropogenic activities. The present study is devoted to the aqueous sorption behaviour of selenium oxyanions (selenate and selenite) on a reference oxide surface, namely rutile TiO(2). Batch sorption kinetics and isotherms have been studied using different physico-chemical conditions of the solution (changes of pH and ionic strength).
View Article and Find Full Text PDFCYP3A4 is the most important drug-metabolizing enzyme that is involved in biotransformation of more than 50% of drugs. Pregnane X receptor (PXR) dominantly controls CYP3A4 inducibility in the liver, whereas vitamin D receptor (VDR) transactivates CYP3A4 in the intestine by secondary bile acids. Four major functional PXR-binding response elements of CYP3A4 have been discovered and their cooperation was found to be crucial for maximal up-regulation of the gene in hepatocytes.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
October 2009
Warfarin is a well-known anticoagulant agent that occurs in two enantiomers, (R)-(+)-warfarin and (S)-(-)-warfarin. A new liquid chromatography method for the determination of both enantiomers was developed, validated and applied in in vitro studies with the aim of evaluating the accumulation of (R)-warfarin and (S)-warfarin in the hepatoma HepG2 cell line. OptiMEM cell cultivation medium samples and cellular lysates were purified using Waters Oasis MAX extraction cartridges.
View Article and Find Full Text PDFThis paper reports a comparative study of three methods for determining the surface charge and acid-base behavior of a TiO(2) rutile material. Electrophoretic mobility measurements were performed using two different batch protocols: (i) a "static" mode that consisted of immersing the rutile powder in aqueous solutions of given pH's and ionic strengths for 10 h, and (ii) a "dynamic" mode that consisted of using an automatic titrator to continuously adjust the solution pH with a contact time of 15 min. The same apparatus (a Nanosizer from Malvern) was used to measure the zeta potential of the particles in both methods.
View Article and Find Full Text PDFAzole antifungal drug ketoconazole has recently been demonstrated as an inhibitor of a ligand-induced pregnane X receptor (PXR)-mediated transcriptional regulation of the CYP3A4 gene through disruption of PXR interaction with steroid receptor coactivator (SRC)-1. In contrast, other clotrimazole-derived antifungal agents are known as potent inducers of CYP3A4 through PXR. In the present study, we examined effects of azole antimycotics clotrimazole, ketoconazole, econazole, oxiconazole, miconazole, fluconazole, and itraconazole on PXR-mediated expression of CYP3A4.
View Article and Find Full Text PDFSP600125, a specific inhibitor of c-Jun-N-Terminal kinase (JNK), was reported as a ligand and antagonist of aryl hydrocarbon receptor (AhR) [Joiakim A, Mathieu PA, Palermo C, Gasiewicz TA, Reiners Jr JJ. The Jun N terminal kinase inhibitor SP600125 is a ligand and antagonist of the aryl hydrocarbon receptor. Drug Metab Dispos 2003;31(11):1279-82].
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