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Identification of specific protein phosphatase-1 (PP1) inhibitors is of special importance regarding the study of its cellular functions and may have therapeutic values in diseases coupled to signaling processes. In this study, we prove that a phosphorylated peptide of the inhibitory region of myosin phosphatase (MP) target subunit (MYPT1), R690QSRRS(pT696)QGVTL701 (P-Thr696-MYPT1690−701), interacts with and inhibits the PP1 catalytic subunit (PP1c, IC50 = 3.84 µM) and the MP holoenzyme (Flag-MYPT1-PP1c, IC50 = 3.84 µM). Saturation transfer difference NMR measurements established binding of hydrophobic and basic regions of P-Thr696-MYPT1690−701 to PP1c, suggesting interactions with the hydrophobic and acidic substrate binding grooves. P-Thr696-MYPT1690−701 was dephosphorylated by PP1c slowly (t1/2 = 81.6–87.9 min), which was further impeded (t1/2 = 103 min) in the presence of the phosphorylated 20 kDa myosin light chain (P-MLC20). In contrast, P-Thr696-MYPT1690−701 (10–500 µM) slowed down the dephosphorylation of P-MLC20 (t1/2 = 1.69 min) significantly (t1/2 = 2.49–10.06 min). These data are compatible with an unfair competition mechanism between the inhibitory phosphopeptide and the phosphosubstrate. Docking simulations of the PP1c-P-MYPT1690−701 complexes with phosphothreonine (PP1c-P-Thr696-MYPT1690−701) or phosphoserine (PP1c-P-Ser696-MYPT1690−701) suggested their distinct poses on the surface of PP1c. In addition, the arrangements and distances of the surrounding coordinating residues of PP1c around the phosphothreonine or phosphoserine at the active site were distinct, which may account for their different hydrolysis rate. It is presumed that P-Thr696-MYPT1690−701 binds tightly at the active center but the phosphoester hydrolysis is less preferable compared to P-Ser696-MYPT1690−701 or phosphoserine substrates. Moreover, the inhibitory phosphopeptide may serve as a template to synthesize cell permeable PP1-specific peptide inhibitors. [ABSTRACT FROM AUTHOR]

Epigallocatechin-3-gallate (EGCG) has widespread effects on adipocyte development. However, the molecular mechanisms of EGCG are not fully understood. We investigate the adipogenic differentiation of human-derived mesenchymal stem cells, including lipid deposition and changes in the expression and phosphorylation of key transcription factors, myosin, protein phosphatase-2A (PP2A), and myosin phosphatase (MP). On day 6 of adipogenic differentiation, EGCG (1–20 µM) suppressed lipid droplet formation, which was counteracted by an EGCG-binding peptide for the 67 kDa laminin receptor (67LR), suggesting that EGCG acts via 67LR. EGCG decreased the phosphorylation of CCAAT-enhancer-binding protein beta via the activation of PP2A in a protein kinase A (PKA)-dependent manner, leading to the partial suppression of peroxisome proliferator-activated receptor gamma (PPARγ) and adiponectin expression. Differentiated cells exhibited a rounded shape, cortical actin filaments, and lipid accumulation. The EGCG treatment induced cell elongation, stress fiber formation, and less lipid accumulation. These effects were accompanied by the degradation of the MP target subunit-1 and increased the phosphorylation of the 20 kDa myosin light chain. Our results suggest that EGCG acts as an agonist of 67LR to inhibit adipogenesis via the activation of PP2A and suppression of MP. These events are coupled with the decreased phosphorylation and expression levels of adipogenic transcription factors and changes in cell shape, culminating in curtailed adipogenesis. [ABSTRACT FROM AUTHOR]

Several ellagitannins inhibited the activity of protein phosphatase-1 (PP1) and -2 A (PP2A) catalytic subunits (PP1c and PP2Ac) with preferential suppression of PP1c over PP2Ac. The inhibitory potency for PP1c followed the order of tellimagrandin I > mahtabin A > praecoxin B > 1.2-Di-O-galloyl-4.6-(S)-HHDP-β-D-glucopyranose > pedunculagin with IC50 values ranging from 0.20 µM to 2.47 µM. The interaction of PP1c and tellimagrandin I was assessed by NMR saturation transfer difference, surface plasmon resonance, isothermal titration calorimetry, and microscale thermophoresis based binding techniques. Tellimagrandin I suppressed viability and phosphatase activity of HeLa cells, while mahtabin A was without effect. Conversely, mahtabin A increased the phosphorylation level of SNAP-25Thr138 and suppressed exocytosis of cortical synaptosomes, whereas tellimagrandin I was without influence. Our results establish ellagitannins as partially selective inhibitors of PP1 and indicate that these polyphenols may act distinctly in cellular systems depending on their membrane permeability and/or their actions on cell membranes. [ABSTRACT FROM AUTHOR]

Abstract CaFe-layered double hydroxide (CaFe-LDH) was prepared by the co-precipitation technique and was treated mechanochemically in a mixer mill. The impacts of grinding frequency (3–21 Hz) and duration of milling (5–240 min) were mapped to learn about the deterioration steps of the layered structure. The possibility of structural reconstruction of the mechanochemically disordered chloride-containing LDH was tested in distilled water as well as in nitrate-containing aqueous solution. The main methods to follow the deformation and the rearrangement process were X-ray diffractometry and infrared spectroscopy, but electron microscopy techniques and thermal analysis were also applied to better understand and visualize the disruption and reconstitution of the LDH framework. Graphical abstract Unlabelled Image Highlights • Studying mechanochemical treatment on CaFe-LDH • Successful structural rehabilitation of the milled samples • Intercalation of nitrate guest anion during the reconstruction • Increased specific surface area in the regained LDH system [ABSTRACT FROM AUTHOR]

Abstract An ultrasonically-assisted mechanochemical method was further improved to increase the yield of high-quality ZnAl 2 -LDH with carbonate interlayer anions. In the LDH formation, the rarely studied temperature, power and pulse character of ultrasound irradiation were investigated to determine the optimal parameters for the synthesis. The as-prepared samples were milled with varying the grinding frequency in order to convert the layered hydroxide structure into ZnAl 2 O 4 spinel. This was the first time that ZnAl 2 O 4 spinel formation was induced mechanochemically. The main method to identify the effects of ultrasonic and mechanochemical treatments was X-ray diffractometry; however, infrared spectroscopy, scanning electron microscopy, and thermal analysis were also applied to follow and compare the mechanochemically induced spinel formation to the more frequently used heat treatment. Graphical abstract The thermal and the mechanochemical transformations of ZnAl-LDH to ZnAl spinel were followed and the resulting materials were compared. Image 1 Highlights • Developing further the ultrasonic mechano-preparation of aluminium-rich ZnAl 2 -LDH. • Mapping the ultrasonic irradiation characteristics on LDH formation. • ZnAl 2 O 4 spinel generation by mechanical and heat treatment of the as-prepared LDH. • Following the LDH degradation and evolution of spinel on two routes by XRD, IR, SEM. [ABSTRACT FROM AUTHOR]

Abstract The construction of Co(II)-amino acid complexes (l -histidine, l -cysteine, l -tyrosine) among the layers of CaAl-layered double hydroxide was attempted. The stepwise intercalation (introducing the anionic form of the amino acid first, then constructing the Co(II) complex) proved to be unsuccessful, while the direct ion exchange of the anionic form of the separately prepared complex provided with the Co(II) complex intercalated substances. The success of the intercalation was verified by X-ray diffractometry. The resulting composite materials were structurally characterized by a range of instrumental methods like UV–vis, inductively coupled plasma–optical emission, mid-range as well as far infrared spectroscopies and scanning electron microscopy. Highlights • Attempted intercalation of Co(II)-amino acid complexes among the layers of CaAl-LDH. • Successful intercalation was achieved using the anionic forms of the separately prepared complexes. • Verification by powder X-ray diffractometry. • Mapping the possible coordination sites with classical and instrumental methods. [ABSTRACT FROM AUTHOR]

The novel type, fungus specific protein phosphatase Z1 of the opportunistic pathogen, Candida albicans (CaPpz1) has several important physiological roles. It consists of a conserved C-terminal catalytic domain and a variable, intrinsically disordered, N-terminal regulatory domain. To test the function of these domains we modified the structure of CaPpz1 by in vitro mutagenesis. The two main domains were separated, four potential protein binding regions were deleted, and the myristoylation site as well as the active site of the enzyme was crippled by point mutations G2A and R262L, respectively. The in vitro phosphatase activity assay of the bacterially expressed recombinant proteins indicated that the N-terminal domain was inactive, while the C-terminal domain became highly active against myosin light chain substrate. The deletion of the N-terminal 1–16 amino acids and the G2A mutation significantly decreased the specific activity of the enzyme. Complementation of the ppz1 Saccharomyces cerevisiae deletion mutant strain with the different CaPpz1 forms demonstrated that the scission of the main domains, the two point mutations and the N-terminal 1–16 deletion rendered the phosphatase incompetent in the in vivo assays of LiCl tolerance and caffeine sensitivity. Thus our results confirmed the functional role of the N-terminal domain and highlighted the significance of the very N-terminal part of the protein in the regulation of CaPpz1. [ABSTRACT FROM AUTHOR]

Aralkyl and aryl selenoglycosides as well as glycosyl selenocarboxylate derivatives were assayed on the activity of protein phosphatase-1 (PP1) and -2A (PP2A) catalytic subunits (PP1c and PP2Ac) in search of compounds for PP1c and PP2Ac effectors. The majority of tested selenoglycosides activated both PP1c and PP2Ac by ∼2–4-fold in a phosphatase assay with phosphorylated myosin light chain substrate when the hydroxyl groups of the glycosyl moiety were acetylated, but they were without any effects in the non-acetylated forms. A peptide from the myosin phosphatase target subunit-1 (MYPT1 23–38 ) that included an RVxF PP1c-binding motif attenuated activation of PP1c by 2-Trifluoromethylbenzyl 2,3,4,6-tetra- O -acetyl-1-seleno-β- d -glucopyranoside (TFM-BASG) and 4-Bromobenzyl 2,3,4,6-tetra- O -acetyl-1-seleno-β- d -glucopyranoside (Br-BASG). MYPT1 23–38 stimulated PP2Ac and contributed to PP2Ac activation exerted by either Br-BASG or TFM-BASG. Br-BASG and TFM-BASG suppressed partially binding of PP1c to MYPT1 in surface plasmon resonance based binding experiments. Molecular docking predicted that the hydrophobic binding surfaces in PP1c for interaction with either the RVxF residues of PP1c-interactors or selenoglycosides are partially overlapped. Br-BASG and TFM-BASG caused a moderate increase in the phosphatase activity of HeLa cells in 1 h, and suppressed cell viability in 24 h incubations. In conclusion, our present study identified selenoglycosides as novel activators of PP1 and PP2A as well as provided insights into the structural background of their interactions establishing a molecular model for future design of more efficient phosphatase activator molecules. [ABSTRACT FROM AUTHOR]

In present work, the enzyme cholesterol oxidase (ChOx) was immobilized by Nafion® (Naf) on Pt,Ru–C nanocomposite and an ionic liquid (IL)–modified carbon paste electrode (CPE) in order to create cholesterol biosensor (Naf/ChOx/Pt,Ru–C/IL-CPE). The prepared working electrodes were characterized using scanning electron microscopy–energy-dispersive spectrometry, while their electrochemical performance was evaluated using electrochemical impedance spectroscopic, cyclic voltammetric, and amperometric techniques. Excellent synergism between IL 1-allyl-3-methylimidazolium dicyanamide ([AMIM][DCA]), Pt,Ru–C, and ChOx, as modifiers of CPE, offers the most pronounced analytical performance for improved cholesterol amperometric determination in phosphate buffer solution pH 7.50 at a working potential of 0.60 V. Under optimized experimental conditions, a linear relationship between oxidation current and cholesterol concentration was found for the range from 0.31 to 2.46 µM, with an estimated detection limit of 0.13 µM and relative standard deviation (RSD) below 5.5%. The optimized amperometric method in combination with the developed Naf/ChOx/Pt,Ru–C/IL-CPE biosensor showed good repeatability and high selectivity towards cholesterol biosensing. The proposed biosensor was successfully applied to determine free cholesterol in a human blood serum sample via its enzymatic reaction product hydrogen peroxide despite the presence of possible interferences. The percentage recovery ranged from 99.08 to 102.81%, while RSD was below 2.0% for the unspiked as well as the spiked human blood serum sample. The obtained results indicated excellent accuracy and precision of the method, concluding that the developed biosensor can be a promising alternative to existing commercial cholesterol tests used in medical practice. [ABSTRACT FROM AUTHOR]

We aimed to reveal the mechanisms of mitotic spindle anomalies induced by microcystin-LR (MCY-LR), a cyanobacterial toxin in Vicia faba , a well-known model in plant cell and molecular biology. MCY-LR inhibits type 1 and 2A phosphoserine/threonine specific protein phosphatases (PP1 and PP2A) and induces reactive oxygen species (ROS) formation. The cytoskeleton is one of the main targets of the cyanotoxin during cytopathogenesis. Histochemical-immunohistochemical and biochemical methods were used. A significant number of MCY-LR induced spindle alterations are described for the first time. Disrupted, multipolar spindles and missing kinetochore fibers were detected both in metaphase and anaphase cells. Additional polar microtubule (MT) bundles, hyperbundling of spindle MTs, monopolar spindles, C-S- shaped, additional and asymmetric spindles were detected in metaphase, while midplane kinetochore fibers were detected in anaphase cells only. Several spindle anomalies induced mitotic disorders, i.e. they occurred concomitantly with altered sister chromatid separation. Alterations were dependent on the MCY-LR dose and exposure time. Under long-term (2 and mainly 6 days’) exposure they were detected in the concentration range of 0.1–20 μg mL −1 MCY-LR that inhibited PP1 and PP2A significantly without significant ROS induction. Elevated peroxidase/catalase activities indicated that MCY-LR treated V. faba plants showed efficient defense against oxidative stress. Thus, although the elevation of ROS is known to induce cytoskeletal aberrations in general, this study shows that long-term protein phosphatase inhibition is the primary cause of MCY-LR induced spindle disorders. [ABSTRACT FROM AUTHOR]

In this paper we describe the use of differently sized PbSe quantum dots as photosensitizers for anatase TiO 2 nanowires under visible light illumination. After the organometallic synthesis of PbSe quantum dots with three different average diameters (1.8, 2.5 and 4.7 nm), the nanocrystals were attached to the surface of nanowires with thioglycolic acid as a linker molecule. These quantum dot decorated nanowires were used as photocatalyst in the methyl orange degradation model reaction with promising results. The best performance achieved was 90% degradation of the initial concentration of methyl orange in six hours over 2.5 nm PbSe quantum dot sensitized nanowires using a 40 W quartz UV lamp equipped with a 400 nm cut-off filter. [ABSTRACT FROM AUTHOR]

The serine-threonine protein phosphatases PP2A regulate many cellular processes, however their role in oxidative stress responses and defence is less known. We show the involvement of its C (catalytic) and B" (a regulatory) subunits. The c3c4 (C subunit) and fass (B") subunit mutants and Col wt of Arabidopsis were used. Controls and treatments with the PP2A inhibitor microcystin-LR (MCY-LR) and reactive oxygen species (ROS) inducer diquat (DQ) were employed. ROS levels of primary roots were largely genotype dependent and both C and B" subunit mutants had increased sensitivity to MCY-LR and DQ indicating the involvement of these subunits in oxidative stress induction. Superoxide dismutases (SOD), mainly the Cu/Zn-SOD isoform, as key enzymes involved in ROS scavenging are also showing altered (mostly increased) activities in both c3c4 and fass mutants and have opposite relations to ROS induction. This indicates that the two types of subunits involved have partially different regulatory roles. In relation to this, control and MCY-LR/DQ treated B" subunit mutants were proven to have altered levels of phosphorylation of histone H2AX. γH2AX, the phosphorylated form indicates double stranded DNA damage during oxidative stress. Overall we point out the probable pivotal role of several PP2A subunits in the regulation of oxidative stress responses in plants and pave the way for future research to reveal the signaling pathways involved. • C (catalytic) and B" subunits of PP2A modulate ROS induction and scavenging. • B" subunit regulates histone H2AX phosphorylation, an indicator of DNA damage repair. • PP2A regulates ROS levels and their physiological effects in Arabidopsis. [ABSTRACT FROM AUTHOR]

The article outlines the development of family therapy in Romania. Family therapy has a relatively brief history in this country, only beginning with the first training programs in the early to mid 1990s. However, as far as the number of professional associations is concerned, it is well represented on the map of psychotherapy approaches. There are several opportunities for training in family therapy. The accreditation of the training programs and the certification of the graduates of these programs is clearly regulated by law. From the legal point of view psychotherapy is considered a specialization of psychologists rather than an independent profession. The authors offer a brief overview of the history of family therapy in Romania, its present position in the health and social care system, the context of training, accreditation standards, the network of professional organizations and some of the possible future directions for family therapy. Finally, recently produced Romanian films are suggested as a medium for getting acquainted with the complex dilemmas faced by contemporary Romanian families. [ABSTRACT FROM AUTHOR]

Abstract: Multiwall carbon nanotubes were synthesized using the catalytic chemical vapor deposition (CVD) technique followed by an oxidative purification process. The nanotube modified by functional groups were connected by pre-synthesized oligonucleotides in solution. The material thus obtained was characterized by various microscopic methods. The preparation of nanotube chips is discussed. [Copyright &y& Elsevier]

Abstract: Synthesis of carbon nanotubes (CNTs) from the template molecules of the Si-MCM-41 and Al,Si-MCM-41 mesoporous silicates were investigated. The generation of nanotubes was carried out by graphitization, i.e. applying high temperature treatment of the MCM-41 samples in inert gas atmosphere. The as-synthesized and graphitized samples were characterized by several spectroscopic and physico-chemical methods such as IR and MAS NMR spectroscopy, XRD, TEM, and BET. [Copyright &y& Elsevier]

Transition metal containing spherical MCM-41 silicates were prepared and characterized by transmission electron microscopy (TEM), XRD, BET, TPR and IR spectroscopy. Incorporation of aluminum, iron, cobalt, copper ions into the wall of the pores has been established. These ions were almost completely built in into the silicate framework from the synthesis gel. With increasing iron content the ordering of pores decreased, the hydrogen uptake increased, the acidity gained. Only one electron transfer took place (Fe3+ → Fe2+) during the reduction of Fe-MCM-41 samples up to 923 K, which means that iron is stabilized in the mesoporous structure and probably linked with framework via oxygen ions. For cobalt ion containing samples practically no reduction was observed, however, significant Lewis acidity was detected. The copper containing samples behaved different. Two electron transfers took place upon hydrogen treatment proving the reduction of Cu2+ ions to metallic copper, however, a part of the metallic species can be reversible reoxidized to cationic form. The Cu-MCM-41 samples showed also Lewis acidic character. Both Bronsted and Lewis acidic sites could only be observed by IR spectroscopy when aluminum or iron was incorporated into MCM-41. The Fe-MCM-41 samples showed significant catalytic activity in the acid catalyzed alkylation of toluene with benzyl chloride at 333 K. [Copyright &y& Elsevier]

The present text describes an investigation of XPS study of multiwall carbon nanotube (MWNT) synthesis. The aim of the investigation was not only to improve the reaction activity by mixing nickel with vanadium, but also to understand the formation mechanism of the nanotubes. Carbon nanotubes were produced by catalytic chemical vapor deposition (CCVD) of acetylene on transition metal containing catalysts supported on zeolite ZSM-5. The samples were characterized at two different levels. At the nanoscale, they were studied by transmission electron microscopy (TEM), while at macroscopic scale mainly XPS was used to investigate the changes during the reaction. [Copyright &y& Elsevier]

Microcystin-LR (MC-LR) is a harmful cyanotoxin that inhibits 1 and 2A serine-threonine protein phosphatases. This study examines the influence of MC-LR on chloroplast division and the underlying mechanisms and consequences in Arabidopsis. MC-LR increased the frequency of dividing chloroplasts in hypocotyls in a time range of 1–96 h. At short-term exposures to MC-LR, small-sized chloroplasts (longitudinal diameters ≤6 μm) were more sensitive to these stimulatory effects, while both small and large chloroplasts showed stimulations at long-term exposure. After 48 h, the cyanotoxin increased the frequency of small-sized chloroplasts, indicating the stimulation of division. MC-LR inhibited protein phosphatases in whole hypocotyls and isolated chloroplasts, while it did not induce oxidative stress. We show for the first time that total cellular phosphatases play important roles in chloroplast division and that particular chloroplast phosphatases may be involved in these processes. Interestingly, MC-LR has a protective effect on cyanobacterial division during methyl-viologen (MV) treatments in Synechococcus PCC6301. MC-LR production has harmful effects on ecosystems and it may have an ancient cell division regulatory role in stressed cyanobacterial cells, the evolutionary ancestors of chloroplasts. We propose that cytoplasmic (eukaryotic) factors also contribute to the relevant effects of MC-LR in plants. [Display omitted] • Microcystin-LR (MC-LR) is a harmful cyanotoxin, an inhibitor of protein phosphatases. • MC-LR alters Arabidopsis plastid division at environmentally relevant concentration. • Environmental implications of such subcellular alterations in plants are discussed. • MC-LR also affects cyanobacterial division even during oxidative stress. • MC-LR's evolutionary function may be the regulation of cyanobacterial division. [ABSTRACT FROM AUTHOR]

The voltammetric characterisation and determination of insecticide flonicamid (N-cyanomethyl-4-(trifluoromethyl)nicotinamide) were performed for the first time using a simple electrochemical sensor, renewable silver-amalgam film electrode (Hg(Ag)FE). During the development of the direct cathodic square wave voltammetric method (SWV) for the determination of flonicamid, a voltammetric behaviour of a target analyte in aqueous Britton-Robinson buffer solution from pH 2.0 to pH 11.98 was examined. In the investigated pH range, the peak which appeared in the potential span between −0.86 V and −1.56 V vs. saturated calomel electrode depending on the applied pH value was chosen for analytical purposes. As optimal pH for the determination of flonicamid, pH 2.5 was selected. Cyclic voltammetric measurements at pH 2.5 confirmed that the electrode reaction mechanism is an irreversible reduction controlled by the diffusion of flonicamid at Hg(Ag)FE. The optimised Hg(Ag)FE-SWV method resulted in good linearity in the concentration range of 1.96–41.2 µg mL−1 while the relative standard deviation of the method was 0.30%. Flonicamid was successfully determined in commercial formulation Teppeki 500 WG® and spiked river water sample by the developed method using the standard addition procedure. The average value of flonicamid amount found in a commercial formulation based on three repetitions was 497.8 ± 0.9 g kg−1, which is in good agreement with the manufacturer's declaration (500 ± 25 g kg−1) and with comparative high-performance liquid chromatographic measurements with diode array detection where a found average value of flonicamid content was 497.5 ± 11.5 g kg−1. The obtained results also indicate that the developed SWV procedure using Hg(Ag)FE was appropriate for the determination of flonicamid in a spiked river water sample with the recovery of 92.86% and RSD of 6.19%. [ABSTRACT FROM AUTHOR]

The presence of alkaline earth cations, in particular, Ca2+ and Mg2+ ions in brine, causes undesired effects in solutions containing anionic surfactants because of precipitate formation. In the present study, an anionic surfactant, sodium dodecyl sulfate (SDS), was investigated, focusing on the determination of various properties (surface tension, critical micelle concentration, micelle size, turbidity) in the presence of alcohols and, in particular, the inhibition of the precipitation of SDS with calcium ions. The calcium ions were added to the surfactant in increasing concentrations (3.0–10.0 g/L), and short-carbon-chain alcohols (methanol, ethanol, n-propanol and n-butanol) were used to shift the onset of precipitate formation. The critical micelle concentration (CMC) of SDS in the presence of alcohols was also determined. It was established that among these alcohols, methanol and ethanol did not exert significant effects on the solubility of the Ca(DS)2 precipitate, while n-propanol and n-butanol were found to be much more efficient inhibitors. In addition, all the alcohols in the applied concentration range (up to 20 V/V%) were found to decrease the critical micelle concentration of SDS. [ABSTRACT FROM AUTHOR]

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•− and holes h+ are the principal species responsible for the pollutant photodegradation. [ABSTRACT FROM AUTHOR]

The implementation of supported metal catalysts heavily relies on the synergistic interactions between metal nanoparticles and the material they are dispersed on. It is clear that interfacial perimeter sites have outstanding skills for turning catalytic reactions over, however, high activity and selectivity of the designed interface‐induced metal distortion can also obtain catalysts for the most crucial industrial processes as evidenced in this paper. Herein, the beneficial synergy established between designed Pt nanoparticles and MnO in the course of the reverse water gas shift (RWGS) reaction resulted in a Pt/MnO catalyst having ≈10 times higher activity compared to the reference Pt/SBA‐15 catalyst with >99 % CO selectivity. Under activation, a crystal assembly through the metallic Pt (110) and MnO evolved, where the plane distance differences caused a mismatched‐row structure in softer Pt nanoparticles, which was identified by microscopic and surface‐sensitive spectroscopic characterizations combined with density functional theory simulations. The generated edge dislocations caused the Pt lattice expansion which led to the weakening of the Pt−CO bond. Even though MnO also exhibited an adverse effect on Pt by lowering the number of exposed metal sites, rapid desorption of the linearly adsorbed CO species governed the performance of the Pt/MnO in the RWGS. [ABSTRACT FROM AUTHOR]

The implementation of supported metal catalysts heavily relies on the synergistic interactions between metal nanoparticles and the material they are dispersed on. It is clear that interfacial perimeter sites have outstanding skills for turning catalytic reactions over, however, high activity and selectivity of the designed interface‐induced metal distortion can also obtain catalysts for the most crucial industrial processes as evidenced in this paper. Herein, the beneficial synergy established between designed Pt nanoparticles and MnO in the course of the reverse water gas shift (RWGS) reaction resulted in a Pt/MnO catalyst having ≈10 times higher activity compared to the reference Pt/SBA‐15 catalyst with >99 % CO selectivity. Under activation, a crystal assembly through the metallic Pt (110) and MnO evolved, where the plane distance differences caused a mismatched‐row structure in softer Pt nanoparticles, which was identified by microscopic and surface‐sensitive spectroscopic characterizations combined with density functional theory simulations. The generated edge dislocations caused the Pt lattice expansion which led to the weakening of the Pt−CO bond. Even though MnO also exhibited an adverse effect on Pt by lowering the number of exposed metal sites, rapid desorption of the linearly adsorbed CO species governed the performance of the Pt/MnO in the RWGS. [ABSTRACT FROM AUTHOR]

An efficient synthetic route was developed to prepare hierarchically ordered mesoporous layered double hydroxide (LDH) materials. Sodium dodecyl sulfate (SDS) was used as a sacrificial template to tune the interfacial properties of the LDH materials during the synthetic process. The SDS dose was optimized to obtain stable dispersions of the SDS-LDH composites, which were calcined, then rehydrated to prepare the desired LDH structures. Results of various characterization studies revealed a clear relationship between the colloidal stability of the SDS-LDH precursors and the structural features of the final materials, which was entirely SDS-free. A comparison to the reference LDH prepared by the traditional co-precipitation-calcination-rehydration method in the absence of SDS shed light on a remarkable increase in the specific surface area (one of the highest within the previously reported LDH materials) and pore volume as well as on the formation of a beneficial pore size distribution. As a proof of concept, the mesoporous LDH was applied as adsorbent for removal of nitrate and dichromate anions from aqueous samples, and excellent efficiency was observed in both sorption capacity and recyclability. These results make the obtained LDH a promising candidate as adsorbent in various industrial and environmental processes, wherever the use of mesoporous and organic content-free materials is required. [ABSTRACT FROM AUTHOR]

• Synthesis and comprehensive characterization of Ce- and Bi-based CeBi mixed oxides. • The Ce-rich mixed oxide was active in the oxidation of toluene. • The Bi-rich mixed oxide was active in the Knoevenagel condensation. • Their mixture catalysed the oxidation-condensation reaction with full selectivity. • The domino reaction proceeded in aqueous environment. Both Bi- and Ce-based CeBi mixed oxides were prepared by a modified sol-gel process from their precursor salts. The mixed as well as the parent oxides were characterized by X-ray diffractometry, Raman, XPS, UV–DRS and X-ray photoelectron spectroscopies, ICP–OES method, scanning and transmission electron microscopies as well as BET surface area, CO 2 - and NH 3 -temperature-programmed desorption measurements. After characterizing the morphology, the acid-base properties, the oxidation states of the cationic components and the porosity of these structures, their catalytic activities were probed in the Koevenagel condensation of benzaldehyde and diethyl malonate and the toluene oxidation to benzaldehyde reactions. Based on the catalytic activities of the oxides in the individual reactions, a catalyst mixture from the Bi- and Ce-based mixed oxides was used successfully in the toluene to benzaldehyde oxidation and benzaldehyde to benzylidene malonate Knoevenagel condensation domino reaction under environmentally benign conditions. [ABSTRACT FROM AUTHOR]

In this study, lightweight cordierite-mullite ceramics with high strength and high thermal-shock resistance were successfully synthesized by solid-state method with the usage of hollow ceramic microspheres. After careful physico-chemical and mechanical characterization, we gained an economical cordierite material with a low bulk density of 1.40 g/cm3 with an apparent porosity of 44.78%, a flexural strength of 20.17 MPa and a coefficient of thermal expansion of 2.26 × 10−6 oC−1 compared to the bulk counterpart with a bulk density of 2.00 g/cm3 with an apparent porosity of 25.75%, a flexural strength of 23.69 MPa and a coefficient of thermal expansion of 2.47 × 10−6 oC−1. As a catalyst support of Na-FeO x , the economical cordierite has proved the same stability and activity in CO 2 hydrogenation towards C 5+ fuels as bulk cordierite-based catalyst counterparts. [ABSTRACT FROM AUTHOR]

This work investigates the effect of the Potassium promoter and the calcination temperature on the catalytic activity in the dry reforming of methane reaction and compares the performance of the Ni, Co, Fe–Al2O3 trimetallic catalysts with the reference Ni–Al2O3. Although higher activity was achieved with the Ni–Al2O3, trimetallic catalysts resulted in a more favorable CO/H2 ratio and considerably better coke resistance. Higher calcination temperature led to the increase in coke formation which caused the sintering of the catalysts. Promoting samples with 0.5%K in order to improve the coke formation resistance, reduced the catalytic activity. [ABSTRACT FROM AUTHOR]

• Mapping the influence of ultrasound irradiation on co-precipitated CaFe-Cl−-LDHs. • Continuous irradiation resulted in elevated crystal thickness and anion incorporation capacity. • On pulsed irradiation, porosity was developed and the aggregate size was reduced. • Detailed thermal, dissolution and optical description of sonocrystallized LDHs was given. • The integrity of the interlayer structure was preserved up to 200 °C. The output power (30–150 W) and the periodicity (20–100%) of ultrasound emission were varied in a wide range to regulate and improve the crystallization process in the commonly used co-precipitation technique of chloride-intercalated CaFe-layered double hydroxides. The influence of ultrasound irradiation on the as-prepared materials was studied by X-ray diffractometry, dynamic light scattering, UV–Vis–NIR diffuse reflectance spectroscopy, specific surface area measurement, pore size analysis, ion-selective electrode potentiometric investigations and thermogravimetry. Additionally, structural alterations due to heat treatment at various temperatures were followed in detail by Fourier-transform infrared and X-ray absorption spectroscopies as well as scanning electron microscopy. The ultrasonic treatment was capable of controlling the sizes of primarily formed (from 19 nm to 30 nm) as well as the aggregated (secondary) particles (between 450 nm and 700 nm), and thus modifying their textural parameters and enhancing the incorporation of chloride anions into the interlamellar space. For the first time, the optical energy gap of CaFe-LDH was reported here depending on the nature of applied stirring (4.18–4.34 eV). The heat-treatment investigations revealed that the layered structure was stabile until 200 °C, even at the atomic level. [ABSTRACT FROM AUTHOR]

Titanate nanostructures are of great interest for catalytic applications because their high surface area and cation exchange capacity create the possibility to achieve high metal dispersion. Ion exchange allows titanate nanostructures to incorporate metal adatoms in their framework. Consequently, the curved layers contain a large amount of defect sites, typically oxygen vacancies and Ti3+ centers, which can make them promising photocatalysts, because the defect sites can trap photoelectrons or holes extending the lifetime of the excited state. Due to the large amount of defects, titanate nanotubes (TNT) can stabilize sub-nanosized gold clusters, presumably in Au25 form. This perspective summarizes the previous results obtained in the photocatalytic transformation of methane in which the size of gold nanoclusters plays an important role. Photocatalytic measurements revealed that methane is active towards photo-oxidation. Methane transforms mainly into hydrogen and, to a lesser extent, to ethane and ethanol. Based on recent additional results, we stress here that gold clusters (Au25) may be directly involved in the photo-induced reactions, namely in the direct activation of the methane/Au25δ+ complex during irradiation. Another new finding is that gold nanoparticles supported on TNT exhibit high catalytic activity in CO2 hydrogenation. Our results revealed fundamental differences in the reaction schemes as the products of the two routes are CO (thermal process) and CH4 (photocatalytic route), indicating the importance of photogenerated electron–hole pairs in the reaction. The presence of gold nanoparticles on the surface has been found to have multiple roles. On the one hand, gold in nano and sub-nano sizes promotes the adsorption and scission of reactants, important for both types of reactions. On the other hand, the gold-support interface forms a rectifying Schottky contact that helps in the separation of photogenerated carriers, thus improving the utilization of electrons and holes in the reduction and oxidation steps, respectively. Furthermore, gold ions (Au+), in the cationic sites of the titanate lattice promote the photocatalytic transformation of formate (which is one of the intermediates), thus advancing the reaction further towards the fully reduced product. The explored reaction schemes may pave the road towards novel catalytic materials that can solve challenges associated with the activation of CH4 and CO2 and thus contribute to green chemistry. [ABSTRACT FROM AUTHOR]

Abstract The structure-forming properties of three 2 H -imidazole 2-thione derivatives were investigated in solution, the solid state as well as over polycrystalline gold surface. The molecules were synthesized in one of our labs, and their interactions were investigated by a range of instrumental methods (FT-IR spectroscopy, FT-IR and FT-Raman microscopies, scanning electron and atomic force microscopies) as well as molecular modelling. Short-range (in solution; N H⋯S hydrogen bonding) as well as long-range ordering (in the crystalline form; S H⋯N hydrogen bonding) of the molecules were observed, and pillared-like structures were seen over the polycrystalline surface. Highlights • Intermolecular interactions of 2H-imidazole thiones were studied. • H-bearing imidazole N and S are involved in H-bonding in solution and the solid state. • Over Au surface S Au coordination bonds fix the first layer, while long-range ordering is via S H⋯N H-bonding. • Verification is with IR and Raman spectroscopies and atomic force microscopy. [ABSTRACT FROM AUTHOR]

The reactions of H2O, H2 D2 and CO with clean and rhodium covered black titania have been investigated by TDS, AES and sensitive temperature programmed work function (TP-WF) measurements to elucidate the complex interactions with this narrow bandgap material promising for visible light energy harvesting. Water formed molecular and dissociative adsorption states with positive outward dipole moments on the reduced, r-TiO2 (110). Surface hydroxyl groups decomposed to H2 and recombined to H2O in a broad temperature range, characterized by TDS peaks at 300, 355-377 and 470 K, which has been associated with surface inhomogeneity. On a strongly reduced, sr-TiO2 (110), a part of H atoms arising from OHa species dissolved in the titania at 200-500 K, and desorbed as H2O with Tp = 570, 670 and 750 K. Sub-monolayer TiOx films produced by stepwise heating on r-TiO2 (110) supported Rh particles suppressed the adsorption of hydrogen, but allowed its spillover to the support. Co-adsorption experiments with D2, H2, H2O and CO on the Rh covered r-TiO2 (110) were also performed. Saturating the Rh by CO at 330 K blocked the uptake of hydrogen on the metal, eliminating its spillover to the support. At 270 K saturation CO exposure removed the pre-adsorbed hydrogen, while at 200 K replaced a part of it decreasing the adsorption bond energy of the rest remained adsorbed. Co-adsorption data proved that the hydrogen desorption states with Tp = 470 and 570 K belong to the decomposition of hydroxyl groups on the r-TiO2 (110) support and at the Rh-TiOx interface, respectively. It is remarkable that the latter state can evolve in the presence of adsorbed CO, which exhibits reactivity towards the same interface. [ABSTRACT FROM AUTHOR]

Glucose-to-fructose isomerization is the key process in the reaction sequence that can lead to the total conversion of biomass into valuable fine chemicals. However, it is challenging to find an efficient, cost-effective- and waste-minimized process to produce High Fructose Corn Syrup (HFCS) without using non-green approaches. To this end, hydrotalcite (MgAl-layered double hydroxides (MgAl-LDH)) catalyzed glucose isomerization in ethanol seemed to be one of the most promising processes in the last decade. In contrast to the well-studied reaction carried out in aqueous solutions, when ethanolic solutions are used, many potentially important properties of the LDHs cannot be studied in terms of how they affect their own catalytic abilities. Neither the effect of the basic site distribution, nor the morphological aspects and the role of surface hydration have been elucidated so far. In this study, the systematic alteration of the textural and structural parameters of hydrotalcites and hydrocalumites (Ca2Al-LDH) revealed clear structure–activity-selectivity relationships. These indicate that the rate-determining factor is the hydrophilicity and the LDH surface factors affecting it, which determine the catalytic performance of the LDH catalyst more than any other factor. This is evidenced by the fact that the catalytic efficiency of hydrotalcites can be improved by reducing their basicity. When isomerizations catalyzed by the easily recyclable LDH with suitable surface features are carried out, a truly similar catalytic performance (71% glucose conversion, 83% fructose selectivity, 59% fructose yield) can be achieved as was previously described, but at a significantly lower reaction temperature (120 °C → 80 °C). [ABSTRACT FROM AUTHOR]

An ultrasonically-enhanced mechanochemical method was developed to synthesize CaFe-layered double hydroxides (LDHs) with various interlayer anions (CO 3 2− , NO 3 − , ClO 4 − , N 3 − , F − , Cl − , Br − and I − ). The duration of pre-milling and ultrasonic irradiation and the variation of synthesis temperature in the wet chemical step were investigated to obtain the optimal parameters of preparation. The main method to characterize the products was X-ray diffractometry, but infrared and synchrotron-based X-ray absorption spectroscopies as well as thermogravimetric measurements were also used to learn about fine structural details. The synthesis method afforded successful intercalation of the anions, among others the azide anion, a rarely used counter ion providing a system, which enables safe handling the otherwise highly reactive anion. The X-ray absorption spectroscopic measurements revealed that the quality of the interlayered anions could modulate the spatial arrangement of the calcium ions around the iron(III) ions, but only in the second coordination sphere. [ABSTRACT FROM AUTHOR]

NiMgAl-, CuNiAl- and CuMgAl-layered double hydroxides were prepared and after calcination, they were used to promote the hydrodechlorination of trichloroethylene. The calcined materials were active in the reaction and remained so in the repeated reaction after applying the rehydration-recalcination regeneration protocol. The freshly prepared, the calcined, the used, as well as the regenerated materials were studied by a range of methods (X-ray diffractometry, scanning electron microscopy, energy-dispersive X-ray analysis, BET surface area measurements). These results together with reaction data proved that the calcined layered double hydroxides, even without noble metal additives, acted as occasionally highly active and always highly hydrocarbon-selective catalysts in the hydrodechlorination reaction. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the processability of API-titanate nanotube composites into direct compressed tablets and therefore to reveal the benefits of the composite formation provided in tablet manufacturing. Diltiazem hydrochloride, diclofenac sodium, atenolol, hydrochlorothiazide and their 1:1 ratio composites formed with titanate nanotubes (TNTs) were used for the comparative investigations focusing on flowability, compaction behaviour and post-compressional property measurements. The flowability was studied by measuring the flow time, the angle of repose, the Hausner Ratio and the Compressibility Index, while the compaction properties were estimated by the use of out-of-the-die method applying Kawakita and Walker models. The tablet properties were described by determining the apparent tablet density, the breaking strength and the disintegration time. Based on the experimental results, the composites have superior flowability and display better compactibility and compressibility than the pure APIs. These findings were supported by the more favourable post-compressional properties shown by the composite containing tablets. However, the measurements also revealed that the advantageous effect of TNTs on drug tablettability depends on the efficiency of the incorporation process. [ABSTRACT FROM AUTHOR]

We report base-catalyzed upgrading of bio-based levulinic acid to methyl levulinate fuel additive with the assistance of microwave (MW) irradiation. During the reactions, formation of crystalline sodium, potassium, rubidium levulinate intermediates occurred. The methylation potential of dimethyl carbonate was found to be excellent at 120 °C under MW conditions; moreover, alkylation could also occur at the boiling point (∼90 °C) of solvent. Precipitation of levulinate salts could be reduced by addition of co-solvents, and thus yields of methyl levulinate increased to over 90 %. The detailed investigation of effects of MW-assisted reaction revealed the accelerated formation of metal levulinates and the behavior of levulinate salts, base catalysts as "molecular radiators". This allows us to focus on replacement of generally used K 2 CO 3 catalyst (showing MW-enhanced decomposition though CO 2 liberation). Several inorganic bases were tested and K 3 PO 4 proved to be the best green and economically friendly alternative with higher reusability potential. [Display omitted] • Conversion of renewable levulinic acid to methyl levulinate under basic condition. • Microwave-enhanced methylation activity of dimethyl carbonate solvent/reagent. • Significant reduction in methylation temperature under microwave conditions. • Study of the thermal and non-thermal (specific) factors of the microwave radiation. • Replacing the commonly used solid catalyst K 2 CO 3 with the more reusable K 3 PO 4. [ABSTRACT FROM AUTHOR]

Multidrug resistance (MDR) is a serious hurdle to successful cancer therapy. Here, we examined the efficiency of novel semi-synthetic dihydrotestosterone derivatives, more specifically androstano-arylpyrimidines in inhibiting the efflux activity of ATP-binding cassette (ABC) transporters and sensitizing inherently MDR colon cancer cells to various chemotherapy drugs. Using the Rhodamine123 accumulation assay, we evaluated the efflux activity of cancer cells following treatments with androstano-arylpyrimidines. We found that acetylated compounds were capable of attenuating the membrane efflux of inherently MDR cells; however, deacetylated counterparts were ineffective. To delineate the possible molecular mechanisms underlying these unique activities of androstano-arylpyrimidines, the degree of apoptosis induction was assessed by AnnexinV-based assays, both upon the individual as well as by steroid and chemotherapy agent combination treatments. Five dihydrotestosterone derivatives applied in combination with Doxorubicin or Epirubicin triggered massive apoptosis in MDR cells, and these combinations were more efficient than chemotherapy drugs together with Verapamil. Furthermore, our results revealed that androstano-arylpyrimidines induced significant endoplasmic reticulum stress (ER stress) but did not notably modulate ABC transporter expression. Therefore, ER stress triggered by acetylated androstano-arylpyrimidines is probably involved in the mechanism of efflux pump inhibition and drug sensitization which can be targeted in future drug developments to defeat inherently multidrug-resistant cancer. [ABSTRACT FROM AUTHOR]

Strontium titanate (STO) photocatalysts were prepared via a slightly modified Pechini sol–gel method. A unique rapid calcination technique with a short exposure time was used to obtain crystalline products. The samples were characterized by X-ray diffractometry, scanning electron microscopy, diffuse reflectance spectroscopy, infrared spectroscopy, nitrogen adsorption–desorption measurements, and X-ray photoelectron spectroscopy. Their photocatalytic activity was evaluated by the photocatalytic oxidation of phenol, oxalic acid, and chlorophenol under UV light irradiation using commercial STO as a reference. These pollutants, together with glucose and propanol, were used to investigate the stability of the samples against various functional groups. All our samples exhibited higher photocatalytic activity than the commercial STO reference. With increasing calcination temperature, the crystallinity and primary crystallite sizes increased while the band gaps and specific surface areas decreased. The photocatalytic activity of the most efficient sample was explained by the presence of SrCO3 on its surface. The STO catalysts were highly stable as they largely retained their crystalline composition after exposure to chemicals with different functional groups. Finally, we compared the costs associated with the unique calcination technique with a more conventional one and found that our method is ~35% more cost-effective. [ABSTRACT FROM AUTHOR]

A considerable promotional effect of MoO x species observed at high pressures on the catalytic activity of rhodium initiated the present UHV model study. The MoO x overlayers formed on Rh films (0.15–20.0 ML) supported by TiO 2 (110) substrate were characterized by AES, TPD, work function (WF) measurements and CO adsorption. On the mixed oxide support produced by depositing 1.2 ML Mo onto TiO 2 (110), a new recombinative CO desorption state was observed with T p =700 K, assigned as β-CO and related to the promotional effect of MoO x species diffused onto Rh particles of 1.0 ML coverage. The development of β-CO needs 0.5–0.7 ML threshold Rh coverage, attributable to particle size effect and geometric factors governing the CO adsorption. The β-CO state with T p =725–742 K could also be detected on Rh films covered by MoO x moiety formed by the oxidation of Mo overlayers in O 2 . Remarkably, recombinative CO desorption with T p =700 K could be observed on the Rh nanoparticles covered by MoO z C y produced from pure Mo deposits by CO adsorption, too. In harmony with the promotional effect of MoO x overlayer found at high pressures, it is established that the dissociation of CO is maximal at 0.2–0.3 ML Mo coverage, attributed to the presence of active sites at the oxide-metal interface. The low desorption peak temperature (700 K) of associative CO desorption observed in the presence of MoO x and MoO z C y overlayers indicates a low activation energy for the reactions of O a and C a atoms, allowing high reaction rates for these intermediates. The MoO x species exerted both promotion and inhibition effects on CO adsorption at sub-monolayer coverages, but above 1 ML it completely suppressed the reactivity of rhodium layers towards CO, suggesting that its surface concentration is a critical factor. [ABSTRACT FROM AUTHOR]

Titanate nanotube (TNT) has recently been explored as a new carrier material for active pharmaceutical ingredients (API). The aim of the present work was to reveal the physicochemical properties of API-TNT composites, focusing on the interactions between the TNTs and the incorporated APIs. Drugs belonging to different Biopharmaceutical Classification System (BCS) classes were loaded into TNTs: diltiazem hydrochloride (BCS I.), diclofenac sodium (BCS II.), atenolol (BCS III.) and hydrochlorothiazide (BCS IV.). Experimental results demonstrated that it is feasible for spiral cross-sectioned titanate nanotubes to carry drugs and maintain their bioactivity. The structural properties of the composites were characterized by a range of analytical techniques, including FT-IR, DSC, TG–MS, etc. The interactions between APIs and TNTs were identified as electrostatic attractions, mainly dominated by hydrogen bonds. Based on the results, it can be stated that the strength of the association depends on the hydrogen donor strength of the API. The drug release of incorporated APIs was evaluated from compressed tablets and compared to that of pure APIs. Differences noticed in the dissolution profiles due to incorporation showed a correlation with the strength of interactions between the APIs and the TNTs observed in the above analytical studies. [ABSTRACT FROM AUTHOR]

From aqueous NaOH/Ca(OH) 2 /NaAl(OH) 4 mixtures, after allowing short reaction times we observed the precipitation of Ca(OH) 2 (s) at lower, and a mixture of Ca(OH) 2 (s) and a layered double hydroxide, hydrocalumite (HC) at higher aluminate concentrations. From the maximum aluminate concentration, at which the equilibrium solid phase is still portlandite ( i.e. , further increase in the aluminate concentration results in HC appearing in the precipitate beside the portlandite), the concentration based solubility products of two polymorphs of HC with the formula of [Ca 2 Al(OH) 6 ]OH· n H 2 O (differing in n ) has been estimated and was found to be log L HC =−11.4 at 25 °C and −12.1 at 75 °C, respectively (where L HC =[Ca 2+ ] 2 [Al(OH) 4 − ][OH − ] 3 ) and at constant ionic strength (I=1 M NaCl). To the best of our knowledge, this is the first published estimate for the solubility product of hydrocalumite. Additionally, from the composition obtained for NaOH/Ca(OH) 2 /NaAl(OH) 4 mother liquors in equilibrium with Ca(OH) 2 (s), attempts were made to extract the formation constant of the ion pair CaAl(OH) 4 + . It was found, that the effects caused by the supposed formation of this solution species are too small to be reliably determined, which allowed an upper estimate for its formation constant, K , to be suggested in the temperature range of 25–75 °C ( K <200 and 40 M −1 at 25 and 75 °C, respectively). [ABSTRACT FROM AUTHOR]

Protein phosphatase Z (Ppz) is a fungus specific enzyme that regulates cell wall integrity, cation homeostasis and oxidative stress response. Work on Saccharomyces cerevisiae has shown that the enzyme is inhibited by Hal3/Vhs3 moonlighting proteins that together with Cab3 constitute the essential phosphopantothenoylcysteine decarboxylase (PPCDC) enzyme. In Candida albicans CaPpz1 is also involved in the morphological changes and infectiveness of this opportunistic human pathogen. To reveal the CaPpz1 regulatory context we searched the C. albicans database and identified two genes that, based on the structure of their S. cerevisiae counterparts, were termed CaHal3 and CaCab3. By pull down analysis and phosphatase assays we demonstrated that both of the bacterially expressed recombinant proteins were able to bind and inhibit CaPpz1 as well as its C-terminal catalytic domain (CaPpz1-Cter) with comparable efficiency. The binding and inhibition were always more pronounced with CaPpz1-Cter, indicating a protective effect against inhibition by the N-terminal domain in the full length protein. The functions of the C. albicans proteins were tested by their overexpression in S. cerevisiae. Contrary to expectations we found that only CaCab3 and not CaHal3 rescued the phenotypic traits that are related to phosphatase inhibition by ScHal3, such as tolerance to LiCl or hygromycin B, requirement for external K+ concentrations, or growth in a MAP kinase deficient slt2 background. On the other hand, both of the Candida proteins turned out to be essential PPCDC components and behaved as their S. cerevisiae counterparts: expression of CaCab3 and CaHal3 rescued the cab3 and hal3 vhs3 S. cerevisiae mutations, respectively. Thus, both CaHal3 and CaCab3 retained the PPCDC related functions and have the potential for CaPpz1 inhibition in vitro. The fact that only CaCab3 exhibits its phosphatase regulatory potential in vivo suggests that in C. albicans CaCab3, but not CaHal3, acts as a moonlighting protein. [ABSTRACT FROM AUTHOR]

Anionic surfactants, such as sodium linear alkylbenzene sulfonates (NaLAS), are utilized in various fields, including industry, household, and agriculture. The efficiency of their use in aqueous environments is significantly affected by the presence of cations, Ca2+ and Mg2+ in particular, as they can decrease the concentration of the surfactant due to precipitation. To understand cation–sulfonate interactions better, we study both NaLAS colloidal solutions in the presence of CaCl2 and precipitates forming at higher salt concentrations. Upon addition of CaCl2, we find the surface tension and critical micelle concentration of NaLAS to decrease significantly, in line with earlier findings for alkylbenzylsulfonates in the presence of divalent cations. Strikingly, an increase in the surface tension is discernible above 0.6 g L–1 NaLAS, accompanied by the decrease of apparent micelle sizes, which in turn gives rise to transparent systems. Thus, there appears to be a second critical concentration indicating another micellar equilibrium. Furthermore, the maximum salt tolerance of the surfactant is 0.1 g L–1 Ca2+, above which rapid precipitation occurs yielding sparingly soluble CaLAS2∙2H2O. [ABSTRACT FROM AUTHOR]

The steam reforming of ethanol (SRE) is a key process for the production of H2 and other vital hydrocarbons. The present work describes the synthesis of Platinum‐Gallium (Pt−Ga) nanoalloys supported on mesostructured cellular foam (MCF‐17) via ultrasound‐assisted impregnation method. Ga was substituted with Pt in different wt.% i. e. Pt/MCF‐17, Pt99.9Ga0.1/MCF‐17, Pt99Ga1/MCF‐17, and Pt90Ga10/MCF‐17 and was evaluated towards the SRE at a temperature range of 473K‐773 K towards hydrogen (H2), acetaldehyde (CH3CHO), diethylether (DEE), ethylene (C2H4), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and ethane (C2H6). The SRE activity and H2 formation rate with Pt90Ga10/MCF‐17 catalyst were observed to be 68.1 % and 3047.2 nmole g−1 sec−1, which is 9.8 and 4.5 times more than the Pt/MCF‐17 counterparts. Moreover, as observed from DRIFTS, NH3‐TPD and XPS studies Ga showed high interaction with Pt in the electron deficit state which resulted in the increased dehydrogenating and acidic properties that resulted in a higher yield of H2. [ABSTRACT FROM AUTHOR]

The Gram-negative bacterium Pseudomonas aeruginosa is an important opportunistic human pathogen associated with cystic fibrosis. P. aeruginosa produces two soluble lectins, the d-galactose-specific lectin PA-IL (LecA) and the l-fucose-specific lectin PA-IIL (LecB), among other virulence factors. These lectins play an important role in the adhesion to host cells and biofilm formation. Moreover, PA-IL is cytotoxic to respiratory cells in the primary culture. Therefore, these lectins are promising therapeutic targets. Specifically, carbohydrate-based compounds could inhibit their activity. In the present work, a 3-O-fucosyl lactose-containing tetravalent glycocluster was synthesized and utilized as a mutual ligand of galactophilic and fucophilic lectins. Pentaerythritol equipped with azido ethylene glycol-linkers was chosen as a multivalent scaffold and the glycocluster was constructed by coupling the scaffold with propargyl 3-O-fucosyl lactoside using an azide-alkyne 1,3-dipolar cycloaddition reaction. The interactions between the glycocluster and PA-IL or PA-IIL were investigated by isothermal titration microcalorimetry and saturation transfer difference NMR spectroscopy. These results may assist in the development of efficient anti-adhesion therapy for the treatment of a P. aeruginosa infection. [ABSTRACT FROM AUTHOR]

Effective oxidative transformation of toluene into valuable products was achieved under solvent‐free reaction conditions with as‐prepared nickel nanoparticles as heterogeneous catalysts in liquid phase. The crystalline structure and size of the as‐prepared nanoparticles were confirmed by X‐ray diffractometry (XRD) and dynamic light scattering (DLS). The catalytic implications of the different crystalline forms (face‐centred cubic: fcc; hexagonal close‐packed: hcp) of these nanocatalysts were investigated. The product selectivity of toluene oxidation was found to vary depending on the crystalline forms of the catalyst. Fcc nanocatalysts showed remarkable chemoselectivity (83 mol %) for the product benzyl alcohol and were readily reusable. In contrast, the hcp Ni phase showed reasonable reusability but lower chemoselectivity (29 mol %) compared to its fcc counterpart. Moreover, the simple organic solvents used had a remarkable effect on the crystal structure and phase purity of the Ni nanocrystals, which also affected the catalytic process. [ABSTRACT FROM AUTHOR]

An electrochemical approach is presented based on multiwall carbon nanotubes (MWCNTs) and neodymium(III) hydroxide (Nd(OH)3) nanoflakes for detection of bovine serum albumin (BSA). The materials were characterized morphologically (XRPD, SEM, and HR-TEM) and electrochemically (DPV, EIS). The MWCNTs@Nd(OH)3 composite was used as support for bovine serum albumin polyclonal antibody (anti-BSA). After the antibody immobilization on the electrochemical platform and antigen/antibody binding time (optimum 60 min), the proposed approach shows a linear voltammetric response toward BSA concentration in the range 0.066 to 6.010 ng mL−1 at maximum peak potential of 0.13 V (vs. Ag/AgCl). Limit of detection (LOD) and limit of quantification (LOQ) were 18 pg mL−1 and 61 pg mL−1, respectively. The precision of the method calculated as relative standard deviation (RSD) of five independent measurements was better 3%. The selectivity of the optimized method regarding structurally similar proteins (human serum albumin and human hemoglobin), ions (Na+, K+, Ca2+, and NO2−), or compounds (glucose, ascorbic acid, dopamine, uric acid, paracetamol, and glycine) was found to be satisfactory, with the current changes of less than 5% in the presence of up to 1 × 105 times higher concentrations (depending on the compound) of the listed potential interfering compounds. Practical applicability of immunosensor for BSA determination in cow whey sample, with recovery values in the range 97 to 103%, shows that the developed method has high potential for precise and accurate detection of BSA, as well as exceptional miniaturization possibilities for on-site and equipment-free sensing. [ABSTRACT FROM AUTHOR]

Coupling TiO 2 nanofibers with other semiconductor metal oxides can effectively extend the light absorbability of TiO 2 to the visible range of the electromagnetic spectrum. This study demonstrates the synthesis of TiO 2 –MoO 3 composite nanofibers via electrospinning using Ti and Mo water-soluble precursors. Aqueous solutions of these precursors were added to a PVP solution in N–N dimethylformamide. The mixture was electrospun, followed by annealing in air at 600 °C obtaining oxide nanofibers. The fibers were characterized via thermogravimetry and differential thermal analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy. The diameter of the TiO 2 –MoO 3 fibers was between 90 and 110 nm after annealing, Furthermore, methylene blue dye was used to investigate the photocatalytic activity of the fibers in visible light. TiO 2 –MoO 3 fibers showed the best photocalaytic activity with a rate constant of 0.0018 min−1 while pure TiO 2 and MoO 3 nanofibers had 0.0009 min−1 and 0.0008 min−1 respectively. [Display omitted] • Anatase TiO 2 , orthorhombic MoO 3 and TiO 2 –MoO 3 composite nanofibers were synthesized by electrospinning. • Fibers degraded methylene blue in visible light. • TiO 2 –MoO 3 composite nanofibers showed highest photocatalytic activity. • Coupling TiO 2 –MoO 3 extends light absorption range and decreases charge recombination. [ABSTRACT FROM AUTHOR]

• The preparation of MnIn-LDHs applying air/N 2 /H 2 atmosphere was optimized. • The physico-chemical properties of the LDH with various Mn:In molar ratio was characterized in detail. • MnM(III)-LDHs (M: Al, Sc, Cr, Fe, Ga) were successfully synthesised by using the optimized parameters. • Outstanding catalytic activity of the LDHs was found in hydroquinone oxidation. • MnIn- and MnCr-LDHs showed the highest photocatalytic contributions under UV–Vis light. The preparation of a new member of the hydrotalcite supergroup, i.e. , MnIn-LDHs with Mn:In molar ratios from 5:2 to 8:2 was developed for the first time, by using the co-precipitation technique. The effect of the presence of air, N 2 or H 2 was systematically tested. The physico-chemical properties of the solids were characterized in detail. The application of reductive atmosphere proved to be vital for achieving phase-pure products. While the thermal behavior of the LDHs with different Mn:In molar ratios were largely similar, the increasing Mn:In ratio resulted in decreasing direct optical band gaps from 4.06 to 3.14 eV. By using the optimized conditions found for MnIn-LDHs, Mn 4 M(III)-LDHs were also prepared with M = Al, Sc, Cr, Fe, Ga. The catalytic performance of the various Mn(II)-based LDHs were tested under dark and UV–Vis-illuminated conditions for the transformation of hydroquinone in acetonitrile medium. The photocatalytic mechanism over MnIn-LDHs was studied by radical trapping tests, indicating the photogenerated holes play an important role in the decomposition of hydroquinone and even benzoquinone. The incorporation of Sc(III), Cr(III) and Fe(III) resulted in catalysts with outstanding performance both with and without illumination; under these conditions several metal oxides/semiconductors (like BiVO 4, Bi 2 WO 6 , SrTiO 3 , Bi 2 O 3 , SnO 2 , WO 3 , In 2 O 3 , ZnO and Degussa P25 TiO 2) and even the nonmetallic g-C 3 N 4 proved to be inactive. The largest photocatalytic contributions were measured for the Mn 4 Cr- and Mn 4 In-LDHs. The selectivity and yield of the benzoquinone formation was found to be the largest in the case of the Mn 4 Al-, Mn 4 Fe- and Mn 4 In-LDHs using UV–Vis light source. [Display omitted] [ABSTRACT FROM AUTHOR]