Preparation of submicron CdSxSe1-x@ZrSiO4 inclusion pigment and its application in ink-jet printing

A zircon-based inclusion pigment (CdS_xSe_1-x@ZrSiO₄) for ink-jet printing was successfully synthesized by calcining the precursor formed by coprecipitation of Si⁴⁺ and Zr⁴⁺ on the SiO₂ shell of CdS_xSe_1-x@SiO₂ with PAAS as a surfactant. The pigment with cubic or spheroidal morphologies was fully encapsulated within an intact and dense ZrSiO₄ shell, and the particle size was concentrated between 500 nm and 800 nm. The intact inclusion structure of the pigment particles was not easily damaged in the grinding stage of ink. The inclusion pigment, which was prepared in the optimum condition of pH value of 7.2 ± 0.2 for coprecipitation, calcination temperature of 900–950 ℃ and soaking time of 30 min, has a high quality of red hue, achieving the chromaticity values of L* = 62.03, a* = 27.35 and b* = 19.64, respectively. The red ink made from this pigment has a good thermal stability and color effect in glazes after calcination at 1210 ℃ for 30 min.     

Evaluation of the biocompatibility and growth inhibition of bacterial biofilms by ZnO,Fe3O4 and ZnO@Fe3O4 photocatalytic magnetic materials

Magnetic nanostructured materials have found numerous biomedical applications. However, the influence of a magnetic field on the inhibition of pathogenic microorganisms has been poorly explored. Zinc and Iron nano-structured oxides have been widely used due to their biocompatibility and their excellent optoelectronic and magnetic properties. Nevertheless, little effort has been devoted to demonstrate their antibacterial activity at doses that are not harmful to mammalians. In this work, ZnO, Fe₃O₄ (MNPs) and ZnO@Fe₃O₄ (NCs) were synthesized and fully characterized. The materials exhibit good antibacterial activity to inhibit the growth of Staphylococcus aureus (S. aureus) and Helicobacter pylori (H. pylori) both, as planktonic cells and as biofilms structures at low doses. The photocatalytic activity of the materials (NCs) was demonstrated when radiated suspensions of NCs and microorganisms (MOs) exhibited higher inhibition growth of MOs in comparison to non-radiated assays. The materials show better antibacterial activity for biofilm growth inhibition in comparison to commercially available antibiotics. Magnetic antimicrobial films were fabricated by in situ deposition of MNPs in Arabic gum (AG) solution. The films exert enhanced antibacterial activity against S. aureus growth due to Fe³⁺lixiviation and magnetic disruption. Regarding the biocompatibility of the materials, ZnO modifies significantly biochemical parameters in Wistar rats after acute administration. Our results show that the composite ZnO@Fe₃O₄ at low doses: (a) exerts an optimum inhibition on the biofilm formation of microorganisms due to its synergetic activity of lixiviation of ions and oxidative activity; (b) good biocompatibility of the composite with living cells. These properties suit ZnO@Fe₃O₄ as potential candidates for the development of new anti-biofilm formulation.     

The First Step of Biodegradation of 7-Hydroxycoumarin in Pseudomonas mandelii 7HK4 Depends on an Alcohol Dehydrogenase-Type Enzyme

Coumarins are well known secondary metabolites widely found in various plants. However, the degradation of these compounds in the environment has not been studied in detail, and, especially, the initial stages of the catabolic pathways of coumarins are not fully understood. A soil isolate Pseudomonas mandelii 7HK4 is able to degrade 7-hydroxycoumarin (umbelliferone) via the formation of 3-(2,4-dihydroxyphenyl)propionic acid, but the enzymes catalyzing the α-pyrone ring transformations have not been characterized. To elucidate an upper pathway of the catabolism of 7-hydroxycoumarin, 7-hydroxycoumarin-inducible genes hcdD, hcdE, hcdF, and hcdG were identified by RT-qPCR analysis. The DNA fragment encoding a putative alcohol dehydrogenase HcdE was cloned, and the recombinant protein catalyzed the NADPH-dependent reduction of 7-hydroxycoumarin both in vivo and in vitro. The reaction product was isolated and characterized as a 7-hydroxy-3,4-dihydrocoumarin based on HPLC-MS and NMR analyses. In addition, the HcdE was active towards 6,7-dihydroxycoumarin, 6-hydroxycoumarin, 6-methylcoumarin and coumarin. Thus, in contrast to the well-known fact that the ene-reductases usually participate in the reduction of the double bond, an alcohol dehydrogenase catalyzing such reaction has been identified, and, for P. mandelii 7HK4, 7-hydroxycoumarin degradation via a 7-hydroxy-3,4-dihydrocoumarin pathway has been proposed.     

Solid-state polymerization of 4-amino-4″-carboxy-p-terphenyl

The synthesis of 4-amino-4″-carboxy-p-terphenyl is reported and a solid-state polycondensation reaction of the synthesized product is studied by thermogravimetry. From the isothermal weightloss-time curves the rates of volatilization of water evolved during the polyamidation reaction were calculated and, by applying the Arrhenius relationship, the activation energy (46 kcal mol^?1) of the process was obtained. Infrared spectra of the poly[4,4″(p-terphenylene)amide] formed at various temperatures, electrical conductivity data and activation energy values, for both the monomer and polymer, are given.     

Isothermal calorimetry investigation of Li1+xMn2−yAlzO4 spinel

The heat generation of LiMn₂O₄, Li_1.156Mn_1.844O₄, and Li_1.06Mn_1.89Al_0.05O₄ spinel cathode materials in a half-cell system was investigated by isothermal micro-calorimetry (IMC). The heat variations of the Li/LiMn₂O₄ cell during charging were attributed to the LiMn₂O₄ phase transition and order/disorder changes. This heat variation was largely suppressed when the stoichiometric spinel was doped with excess lithium or lithium and aluminum. The calculated entropy change (dE/dT) from the IMC confirmed that the order/disorder change of LiMn₂O₄, which occurs in the middle of the charge, was largely suppressed with lithium or lithium and aluminum doping. The dE/dT values obtained did not agree between the charge and the discharge at room temperature (25 °C), which was attributed to cell self-discharge. This discrepancy was not observed at low temperature (10 °C). Differential scanning calorimeter (DSC) results showed that the fully charged spinel with lithium doping has better thermal stability.     

Densification and grain growth during solid state sintering of LaPO4

This work is devoted to the kinetic study of densification and grain growth of LaPO₄ ceramics. By sintering at a temperature close to 1500 °C, densification rate can reach up to 98% of the theoretical density and grain growth can be controlled in the range 0.6–4 μm. Isothermal shrinkage measurements carried out by dilatometry revealed that densification occurs by lattice diffusion from the grain boundary to the neck. The activation energy for densification (E_D) is evaluated as 480 ± 4 kJ mol⁻¹. Grain growth is governed by lattice diffusion controlled pore drag and the activation energy (E_G) is found to be 603 ± 2 kJ mol⁻¹. The pore mobility is so low that grain growth only occurs for almost fully dense materials.     

Neodymium substituted CaBi4Ti4O15 bismuth layered compound

In the present work, CaBi_4−xNd_xTi₄O₁₅ (0 ≤ x ≤ 1) ceramics were prepared and characterized. Although the substitution of Nd³⁺ for Bi³⁺ led to a decrease of tolerance factor t, the ferroelectricity in CaBi_4−xNd_xTi₄O₁₅ was not enhanced but weakened. With increasing x, the Curie temperature of CaBi_4−xNd_xTi₄O₁₅ was lowered and the peak of dielectric constant was significantly suppressed. Besides, the variation of lattice parameters of CaBi_4−xNd_xTi₄O₁₅ showed an approach of a and b, which revealed a development trend from ferroelectric orthorhombic structure to the prototype tetragonal structure with the substitution. This strongly suggested that Bi³⁺ is crucial for the ferroelectricity in four-layered CaBi₄Ti₄O₁₅, just like found in two-layered Bi₃TiNbO₉ and three-layered Bi₄Ti₃O₁₂ compounds. The importance of Bi³⁺ to the ferroelectricity should be due to the special electron configuration of Bi³⁺ but not its relatively small size, since Nd³⁺ is even smaller than Bi³⁺. The size mismatch between A-site cations and the provskite cuboctahedral cavity, indicated by t, seemed to play a secondary role in the contribution to the ferroelectricity of CaBi₄Ti₄O₁₅ and its analogues. The dielectric properties of CaBi_4−xNd_xTi₄O₁₅ ceramics were also investigated at microwave resonant frequency.     

Systematic Analysis and Expression Profiles of the 4-Coumarate: CoA Ligase (4CL) Gene Family in Pomegranate (Punica granatum L.)

4-Coumarate:CoA ligase (4CL, EC6.2.1.12), located at the end of the phenylpropanoid metabolic pathway, regulates the metabolic direction of phenylpropanoid derivatives and plays a pivotal role in the biosynthesis of flavonoids, lignin, and other secondary metabolites. In order to understand the molecular characteristics and potential biological functions of the 4CL gene family in the pomegranate, a bioinformatics analysis was carried out on the identified 4CLs. In this study, 12 Pg4CLs were identified in the pomegranate genome, which contained two conserved amino acid domains: AMP-binding domain Box I (SSGTTGLPKGV) and Box II (GEICIRG). During the identification, it was found that Pg4CL2 was missing Box II. The gene cloning and sequencing verified that this partial amino acid deletion was caused by genome sequencing and splicing errors, and the gene cloning results corrected the Pg4CL2 sequence information in the ‘Taishanhong’ genome. According to the phylogenetic tree, Pg4CLs were divided into three subfamilies, and each subfamily had 1, 1, and 10 members, respectively. Analysis of cis-acting elements found that all the upstream sequences of Pg4CLs contained at least one phytohormone response element. An RNA-seq and protein interaction network analysis suggested that Pg4CL5 was highly expressed in different tissues and may participate in lignin synthesis of pomegranate. The expression of Pg4CL in developing pomegranate fruits was analyzed by quantitative real-time PCR (qRT-PCR), and the expression level of Pg4CL2 demonstrated a decreasing trend, similar to the trend of flavonoid content, indicating Pg4CL2 may involve in flavonoid synthesis and pigment accumulation. Pg4CL3, Pg4CL7, Pg4CL8, and Pg4CL10 were almost not expressed or lowly expressed, the expression level of Pg4CL4 was higher in the later stage of fruit development, suggesting that Pg4CL4 played a crucial role in fruit ripening. The expression levels of 4CL genes were significantly different in various fruit development stages. The results laid the foundation for an in-depth analysis of pomegranate 4CL gene functions.     

Synthesis of butterfly-like BiVO4/RGO nanocomposites and their photocatalytic activities

A simple and high efficient method was proposed for the synthesis of uniform three dimensional(3D) BiVO_4/reduced graphene oxide(RGO) nanocomposite photocatalyst by adopting the microwave assistant and using Bi(NO_3)_3·5H_2O, graphene oxide(GO) and NH_4VO_3 as precursor. The as-obtained composites were well characterized with the aid of various techniques to study the morphology, structure, composition, optimal and electrical property. In the as-obtained composites, the GO sheets were fully reduced into RGO, and monoclinic structure BiVO_4 crystallized completely into butterfly-like BiVO_4 lamellas and well bonded with the RGO lamellas. The length and the width of the butterfly-like BiVO_4 particle were about 1.5 μm, and the thickness of the flake was about 20 nm. Photocatalytic performances of BiVO_4/RGO composite and pure BiVO_4 particle have been evaluated by investigating the reduction of Cr(Ⅵ) ion-contained wastewater under simulated solar light irradiation, where the BiVO_4/RGO composite displayed enhanced photocatalytic activity. It is found that the pseudo-first-order rate constants(k) for the photocatalytic reduction of Cr(VI) by BiVO_4/RGO composite was about 4 times as high as that of the pure BiVO_4. The present work suggested that the combination of BiVO_4 and RGO displayed a remarkable synergistic effect, which led to enhanced photo-catalytic activity on Cr(Ⅵ) reduction.     

Microwave dielectric properties and sintering behaviors of scheelite compound CaMoO4

The microwave dielectric properties, sintering behaviors of scheelite compound CaMoO₄ were investigated using dilatometry, X-ray diffraction, scanning electron microscopy and network analyzer. To improve the sintering property of CaMoO₄, samples with different Ca/Mo ratio were prepared. The bulk densities of CaMo_(x)O₄ (for x = 1.02, 1.05, 1.08) samples were higher than those of pure CaMoO₄ over all temperature range. The well-sintered CaMo_(x)O₄ (for x = 1.02) sample with ∼95.7% of the theoretical density shows Q × f value of 71,000 GHz and dielectric constant (ɛ_r) = 10.3. The effects of liquid phase formation on sintering process and dielectric properties were discussed. Sample with hot-press sintering was also prepared in order to investigate dielectric properties of fully dense CaMoO₄, which exhibited quality factor (Q × f), ∼55,000 GHz and dielectric constant (ɛ_r) = 11.7.     

N-(2-biphenylenyl)-4-[2′-phenylethynyl]phthalimide—new monomer synthesis, cure and thermal properties of resulting high temperature polymer

A synthetic route is described to a new monomer, N-(2-biphenylenyl)-4-[2′-phenylethynyl]phthalimide (BPP), which contains both phenylethynyl and biphenylene reactive functional groups. The monomer can be made either from N-(2-biphenylene)acetamide or 2-aminobiphenylene, by reaction with the phenylethynyl-containing anhydride. The monomer was characterised fully and the thermal cure of the material was studied by infrared (IR) spectroscopy and differential scanning calorimetry (DSC). The IR spectra showed that the phenylethynyl group reacted completely within 1 h at 370 °C. DSC showed the polymerisation exotherm of BPP centred at 379 °C, lower than two NASA-developed phenylethynyl-terminated imide (PETI) resins. In comparison with the PETI systems, the T_g of cured BPP was ca. 100 °C higher, making it a candidate for possible high temperature applications.     

Quadruped Gait and Regulation of Apoptotic Factors in Tibiofemoral Joints following Intra-Articular rhPRG4 Injection in Prg4 Null Mice

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome leads to diarthrodial joint arthropathy and is caused by the absence of lubricin (proteoglycan 4—PRG4), a surface-active mucinous glycoprotein responsible for lubricating articular cartilage. In this study, mice lacking the orthologous gene Prg4 served as a model that recapitulates the destructive arthrosis that involves biofouling of cartilage by serum proteins in lieu of Prg4. This study hypothesized that Prg4-deficient mice would demonstrate a quadruped gait change and decreased markers of mitochondrial dyscrasia, following intra-articular injection of both hindlimbs with recombinant human PRG4 (rhPRG4). Prg4^−/− (N = 44) mice of both sexes were injected with rhPRG4 and gait alterations were studied at post-injection day 3 and 6, before joints were harvested for immunohistochemistry for caspase-3 activation. Increased stance and propulsion was shown at 3 days post-injection in male mice. There were significantly fewer caspase-3-positive chondrocytes in tibiofemoral cartilage from rhPRG4-injected mice. The mitochondrial gene Mt-tn, and myosin heavy (Myh7) and light chains (Myl2 and Myl3), known to play a cytoskeletal stabilizing role, were significantly upregulated in both sexes (RNA-Seq) following IA rhPRG4. Chondrocyte mitochondrial dyscrasias attributable to the arthrosis in CACP may be mitigated by IA rhPRG4. In a supporting in vitro crystal microbalance experiment, molecular fouling by albumin did not block the surface activity of rhPRG4.     

Sintering behavior,structural evolution,and dielectric properties of Li2+xMgTiO4Fx microwave dielectric ceramics

Herein, the sintering behavior, structural evolution, microstructure, and dielectric properties of Li_2+xMgTiO₄F_x (0 ≤ x ≤ 5) ceramics were investigated. At x ≤ 0.75, Li_2+xMgTiO₄F_x ceramics formed a continuous solid solution with a cubic rock salt structure. Subsequently, a composite ceramic of Li_2+xMgTiO₄F_x and LiF was formed. It was found that the maximum mass percentage of LiF required to fully form a solid solution was between 11% and 13%. The Li_2.75MgTiO₄F_0.75 exhibited the best dielectric properties: ε_r = 16.52, Q × f = 123,574 GHz, and τ_f = −18.11 ppm/°C. The substitution of F^- for O^2- resulted in a lower sintering temperature of 875 °C, which slightly suppressed the volatilization of Li, and thus optimized the dielectric properties. The decrease in lattice vibration damping behavior and the increase in electron cloud density resulted in lower dielectric losses. The reduction in molecular polarization rate led to a reduction in ε_r, and the increase in bond energy optimized τ_f. Good chemical compatibility with Ag electrode was demonstrated, indicating that Li_2+xMgTiO₄F_x ceramics have unlimited potential for LTCC applications.     

THz dielectric properties of AlPO4-BPO4-SiO2 ternaries

0.05AlPO₄-0.05BPO₄-0.90SiO₂ glass-ceramic and glass-free 0.45AlPO₄-0.45BPO₄-0.10SiO₂ ceramic have been prepared by a solid-state reaction process and their terahertz (THz) dielectric responses were characterized by time-domain spectroscopy (TDS) techniques in the frequency range from 0.2 to 1.6 THz. Both samples demonstrate little dielectric dispersions in the (sub) THz frequency range, having dielectric permittivities (ε_r) of ∼3.35(7) and ∼4.06(8), respectively. The dielectric responses are dominated by the phonons and electronic polarizations in the (sub) THz frequency range. The contributions to the relative permittivities from electronic polarization ε_{r ∞} are 1.85(4) and 1.99(4), which are ∼55% and ∼49% of the total ε_r at THz frequencies, respectively_. The dielectric losses of both samples continuously increase with increasing frequency in the THz band, while the loss factor of glass-ceramic is one order of magnitude higher than that of glass-free ceramic. The glass-free sample exhibits extremely high Q×f values of 100,000–190,000 GHz in the THz band, being much higher than that of the glass-ceramic (∼7000–25,000 GHz).     

Influence of Ti4+ substitution for Ta5+ on the crystal structure,Raman spectra,and microwave dielectric properties of Ba3Ta4-4xTi4+5xO21 ceramics

This paper systematically investigated the influence of Ti⁴⁺ substitution for Ta⁵⁺ on the phase composition and microwave dielectric properties of Ba₃Ta_4-4xTi_4+5xO₂₁ (x = 0.1, 0.2, and 0.3) ceramics with hexagonal tungsten bronze-like structures. X-ray diffraction and Rietveld refinement results indicated that single-phase Ba₃Ta₄Ti₄O₂₁ could be obtained only with the x values of 0.1 and 0.2, and a secondary phase was detected at an x value of 0.3. The valence state of Ba₃Ta_4-4xTi_4+5xO₂₁ (x = 0.2) ceramics was analyzed through X-ray photoelectron spectroscopy. Increasing Ti⁴⁺/Ta⁵⁺ ratios could reduce sintering temperature and improve the microwave dielectric properties of Ba₃Ta_4-4xTi_4+5xO₂₁ solid solutions. However, the dielectric properties, particularly the quality factor, of Ba₃Ta_4-4xTi_4+5xO₂₁ ceramics deteriorated severely as a result of oxygen vacancy defects caused by the transition of the valence state from Ti⁴⁺ to Ti³⁺ when x = 0.2 and the coexistence of the secondary phase when x = 0.3. Infrared reflectivity spectroscopy was performed to explore the intrinsic dielectric properties of Ba₃Ta_4-4xTi_4+5xO₂₁ (x = 0.1) ceramics. The measured and extrapolated microwave dielectric properties of Ba₃Ta_4-4xTi_4+5xO₂₁ (x = 0.1) ceramics sintered at 1240 °C for 6 h were ε_r ~ 46.5, Q × f = 13,900 GHz, τ_f ~ +49.4 ppm/°C, and ε_r ~ 44, Q × f = 34,850 GHz.     

Drosophila melanogaster Uncoupling Protein-4A (UCP4A) Catalyzes a Unidirectional Transport of Aspartate

Uncoupling proteins (UCPs) form a distinct subfamily of the mitochondrial carrier family (MCF) SLC25. Four UCPs, DmUCP4A-C and DmUCP5, have been identified in Drosophila melanogaster on the basis of their sequence homology with mammalian UCP4 and UCP5. In a Parkinson’s disease model, DmUCP4A showed a protective role against mitochondrial dysfunction, by increasing mitochondrial membrane potential and ATP synthesis. To date, DmUCP4A is still an orphan of a biochemical function, although its possible involvement in mitochondrial uncoupling has been ruled out. Here, we show that DmUCP4A expressed in bacteria and reconstituted in phospholipid vesicles catalyzes a unidirectional transport of aspartate, which is saturable and inhibited by mercurials and other mitochondrial carrier inhibitors to various degrees. Swelling experiments carried out in yeast mitochondria have demonstrated that the unidirectional transport of aspartate catalyzed by DmUCP4 is not proton-coupled. The biochemical function of DmUCP4A has been further confirmed in a yeast cell model, in which growth has required an efflux of aspartate from mitochondria. Notably, DmUCP4A is the first UCP4 homolog from any species to be biochemically characterized. In Drosophila melanogaster, DmUCP4A could be involved in the transport of aspartate from mitochondria to the cytosol, in which it could be used for protein and nucleotide synthesis, as well as in the biosynthesis of ß-alanine and N-acetylaspartate, which play key roles in signal transmission in the central nervous system.     

Electropolymerization of 4-nitro-1,2-phenylenediamine and electrochemical studies of poly(4-nitro-1,2-phenylenediamine) films

In this work, we report the anodic electropolymerization of 4-nitro-1,2-phenylenediamine (4NoPD) in different supporting electrolytes at different pH. The feasibilities of forming the polymer poly(4-nitro-1,2-phenylenediamine) (P4NoPD) on gold and glassy carbon electrodes (GCE) were shown. The P4NoPD films were generated by continuous potential cycling between −0.15 V and +1.10 V (versus Ag|AgCl, saturated KCl). The pH of the electropolymerization medium, the nature of the background electrolyte and the number of cycles used were found to influence strongly the amount of polymer deposited. The reduction of nitro-groups of the P4NoPD films was also found to be dependent on solution conditions, especially pH.     

Synthesis and characterization of a novel cyclic tetranuclear CoII4 cluster consisting of a quadrilateral core

A novel cyclic tetranuclear cluster, [Co(H₂O)₆][Co₄(ccdp)₂(H₂O)₄]·8H₂O·2CH₃CN (1) with cobalt(II) ions sitting in a quadrilateral has been synthesized and fully characterized by exploiting the flexibility, chelating ability and bridging potential of a carboxylate rich dinucleating ligand, H₅ccdp [H₅ccdp = N,N^′-Bis[2-carboxybenzomethyl]-N,N^′-Bis[carboxymethyl]-1,3-diaminopropan-2-ol]. The crystal structure of 1 contains a [Co₄^II(H₂O)₄)]^2– core unit which is held together by two bridging benzoate potions of the ligands, ccdp^5–. Furthermore, the [Co₄^II(H₂O)₄)]^2– core unit is stabilized and charge neutralized by intermolecular hydrogen bonding and [Co(H₂O)₆]²⁺, respectively.