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Three dixanthones ( 1- 3) and an unprecedented C3h-symmetric trixanthone ( 4) were synthesized through a three-step approach in overall yields above 63 %. These compounds possessed a planar π-conjugated system and formed tight face-to-face columnar stacks, as confirmed by single-crystal structural analysis. In comparison with xanthone, the fluorescence emissions of compounds 1- 4 showed significant red-shifts, with improved quantum yields. Moreover, the fluorescence emissions of compounds 1- 4 could be modulated in a strongly acidic environment without decomposition, which led to a further red-shift of the emissions, as well as enhancement of the emission intensities. These compounds have potential applications as optoelectronic materials and/or chemosensors. [ABSTRACT FROM AUTHOR]

The structural characteristics and properties of three new carbon phases (LA9, LA10, CA12), which have a diamond-like structure and atoms located in crystallographically equivalent positions, are described. The model mechanism of LA9 and LA10 formation is the linking of L and L graphene layers, respectively, and phase CA12 can be formed by linking C tetrahedral clusters. Phases LA9, LA10, and CA12 can also be formed as a result of the polymorphic transformations of three-dimensional graphite phases, when all atoms transform from a three-coordinated into a four-coordinated state. LDA-DFT calculations of the LA9, LA10, and CA12 phases are used to find their geometrically optimized structures and properties (density, total energy, density of states). In addition, powder X-ray diffraction patterns are calculated for these phases and possible methods of their synthesis are analyzed. [ABSTRACT FROM AUTHOR]

A simple, convenient, and controllable strategy was reported in this contribution for protein-assisted synthesis BHb-conjugated PbS nanocubes. Powder X-ray diffraction, energy disperse X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected-area electron diffraction characterizations were used to determine the structure and morphology of BHb-conjugated PbS nanocubes. The prepared PbS nanocrystals with cubic rock salt structure were uniform and monodispersed with homogeneous size around 12 nm. The results of Fourier transform infrared and circular dichroism assay proved that Pb/PbS had coordination interaction with functional groups of BHb besides physical-binding effect, and the secondary structure of protein significantly changed with this interaction. Thermogravimetric analysis results confirmed the existence of BHb in PbS nanocrystals and indicated that the conjugate bonds existed between PbS and BHb. A clear perspective was shown here that special nanostructure could be created by using proteins as a mediating template at the inorganic-organic interface. [ABSTRACT FROM AUTHOR]

Various sized titanate nanofibers were prepared by hydrothermal reaction of aqueous solutions containing the respective alkali (KOH and NaOH) and anatase in stoichiometric amounts at 170-200 °C for 96 h. Their morphological and structural properties were characterized by many methods, including the powder X-ray diffraction (XRD), the scanning electron microscopy (SEM), the fourier transform infrared spectroscopy (FTIR) and the UV/Vis spectrophotometer. Their morphologies depend on the experimental temperature and the solution conditions, in which the alkali metal plays an important role during the experimental process. When the size of titanate samples decrease, the UV-Vis spectra are blue-shift. This work provided an effective hydrothermal method to synthesize titanate nanofibers, which may be applicable to fabrication of other nanomaterials. [ABSTRACT FROM AUTHOR]

Hydroxyapatite/polyamide-66 (HA/PA66) composite scaffolds were prepared using injection-molding technique and also analyzed by means of scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, and mechanical testing. Compared with common methods to fabricate scaffolds, this process can fabricate composite scaffolds in a rapid and convenient manner by adjusting the experimental conditions of foaming agent and shot size. The interactions between PA66 and HA particles affect the crystallization behavior of PA66 and the pore structure of scaffolds. HA particles can increase the stiffness of composite scaffolds accompanied by the reduction of impact strength, pore size and porosity. The obtained 40 wt% HA/PA66 composite scaffolds with a pore size ranging from 100-500 μm and a porosity more than 65% can simultaneously meet the requirements of porous structure and mechanical performance. POLYM. ENG. SCI., 54:1003-1012, 2014. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A novel sodium Alizarin Yellow R structure Na2(C13H8N3O5)2(H2O)6 has been observed by accident when 2-hydroxy-5-((4-nitrophenyl)azo) benzoic acid mono sodium salt (mono sodium salt of Alizarin Yellow R) was regarded as a ligand. The tetramer was measured by single-crystal Xray diffraction, FT-IR spectroscopy and UV/Vis spectroscopy. The tetramer crystallizes in triclinic space group P 1 with a = 7.2202(9) Å, b = 13.0624(15) Å, c = 17.0605(19) Å, α = 77.137(2)°, β = 80.922(2)°, γ = 83.354(2)°. V = 1543.56(3) Å3, Z = 2. There are two crystallographically independent sodium centers in the crystal structure. The local coordination geometry of the two sodium centers [NaO6] could be best depicted as slightly distorted octahedrons. The aromantic π-π stacking plays a considerable part in the constitution of 3D network. [ABSTRACT FROM AUTHOR]

In this research, the stabilization effect of cellulase on the decomposition of hydrogen peroxide was investigated for the first time. It was concluded that, regardless of the decomposition mechanism, the cellulase protein could contribute significantly to peroxide stability. This effect stems from the formation of molecular hydrogen bonding between peroxide and cellulase protein or direct sequestering of free metal ions by amino acids in cellulase. Furthermore, based on this stability, a combined biopolishing and peroxide bleaching protocol was developed to improve cotton quality more efficiently. Afterwards, physicochemical properties such as the weight and strength loss, water absorbency, and carbonyl and carboxyl group content of treated cotton cellulose were measured to show the feasibility of the new method. Fourier-transform infrared (FT-IR) and X-ray diffraction (XRD) analyses indicated that the crystallinity index of cotton was increased due to the preferential hydrolysis of amorphous cellulose by cellulase. [ABSTRACT FROM AUTHOR]

Two coordination polymers, {[Zn2(L)(bpy)] ·2H2O} n ( 1) and [Zn2(L)(bpe)] n ( 2) [H4L = terphenyl-2,2′,4,4′-tetracarboxylic acid, bpy = 4,4′-bipyridine, and bpe = 1,2-bis(4-pyridyl)ethane], were hydrothermally synthesized under similar conditions and characterized by elemental analysis, IR spectroscopy, TGA, and single-crystal X-ray diffraction analysis. Compound 1 has a 3D framework containing Zn-O-C-O-Zn 1D chains. Compound 2 exhibits a 3D framework, which features tubular channels. The channels are occupied by bpe molecules. The differences in the structures demonstrate that the auxiliary dipyridyl-containing ligand has a significant effect on the construction of the final framework. Additionally, the fluorescent properties of the two compounds were also studied in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

We report on a highly sensitive and selective nonenzymatic glucose sensor based on a glassy carbon electrode modified with a composite prepared from nickel(II) hydroxide nanoplates and carbon nanofibers. The nanocomposite was characterized by scanning electron microscopy and powder X-ray diffraction. Electrodes modified with pure Ni(OH) and with the nanocomposite were characterized by electrochemical impedance spectroscopy. Cyclic voltammetric and amperometric methods were used to investigate the catalytic properties of the modified electrodes for glucose electrooxidation in strongly alkaline solution. The sensor exhibits a wide linear range (from 0.001 to 1.2 mM), a low detection limit (0.76 μM), fast response time (< 5 s), high sensitivity (1038.6 μA · mM · cm), good reproducibility, and long operational stability. Application of the nonenzymatic sensor for monitoring glucose in real samples was also demonstrated. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An image depicting powder diffraction is presented.

Two new Cd(II) coordination polymers, [Cd2(btc)(dpe)1.5(H2O)]n(1) and [Cd2(btc)(bpp)(H2O)]n(2), were prepared by the hydrothermal reaction of cadmium nitrate with H4btc (H4btc = biphenyl-2,2?,4,4?-tetracarboxylic acid) in the presence of 1,2-di(4-pyridyl)ethylene (dpe) and = 1,2-bis(4-pyridyl)propane (bpp), respectively, structurally characterized by single-crystal X-ray diffraction, and further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analysis. In1, btc4?connect six Cd2+ions, forming a 3-D (3,3,6)-connected [Cd2(btc)] net, and further connected by 1-D [Cd(dpe)]nchains to construct the final (4,5,6)-connected (42.52.65.7)(43.62.7)(45.53.64.72.8) net. In2, a 3-D [Cd2(btc)] net is also constructed from btc4?connecting six Cd2+ions, giving a 3-D (3,4,7)-connected network. The overall structure of2can be regarded as a (4,4,6)-connected (45.64) (42.5.62.8) (43.54.67.7) framework with bpp linking adjacent Cd ions. Structural comparisons show that the secondary auxiliary N-donors have important effects on the final structure and properties. Photoluminescent properties of1and2are also discussed. [ABSTRACT FROM PUBLISHER]

BiFeO3(BFO), BiFe0.95Co0.05O3(BFCO), Bi0.9Nd0.1FeO3(BNFO) and Bi0.9Nd0.1Fe0.925Co0.075O3(BNFCO) thin films were prepared on Pt/Ti/SiO2/Si(111) substrates by chemical solution deposition (CSD) method. The structural and electrical properties of the thin films were studied. X-ray diffraction analysis showed that the films were single perovskite structure and a phase transition appeared in BNFO and BNFCO thin films. Electrical measurements indicated that the ferroelectric properties of BFO thin films were significantly improved by Nd and Co codoping. Well saturated hysteresis characteristic with large remanent polarization were observed in BNFCO thin film. The conduction mechanisms were investigated to understand the different conduction behavior in these thin films. [ABSTRACT FROM AUTHOR]

Five metal–organic frameworks (MOFs), namely, [Zn2(L1)(BIMB)(μ2-OH)] (1), [Zn3(L1)2(BIMB)3]·4H2O (2), [Zn(HL2)(BIMB)0.5]·H2O (3), [Zn3(L2)2(BIMB)3]·8H2O (4) and [Zn3(L2)2(BIMB)3]·4H2O (5) (H3L1 = 5-(3-carboxybenzyloxy)isophthalic acid, H3L2 = 5-(4-carboxybenzyloxy)isophthalic acid and BIMB = 1,4-di(1H-imidazol-1-yl)benzene), have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Complex 1 is a (3,4)-connected 3D interlocking polycatenated framework with the (63)(66) topology by 2D parallel interpenetration. Complex 2 adopts a self-penetrating 3D (3,4)-connected network with (6·82)(4·6·8)(6·84·9)(4·62·82·10) topology, which contains rotaxane- and catenane-like motifs together. Complex 3 is a 3D supramolecular structure formed by hydrogen bonds between adjacent 2D (4,4) sheets. For complex 4, it shows a three-folded 3D framework by a (3,4)-connected net with (62·8)(4·6·8)(63·7·8·9)(4·62·72·8)(62·72·92) topology. Complex 5 is a (3,4)-connected 3D framework. We have discussed the influence of synthetic conditions and different carboxylate ligands on the final structures. In addition, powder X-ray diffraction and photoluminescent properties for 1–5 have been studied in detail at room temperature. [ABSTRACT FROM AUTHOR]

The robustly porous metal-organic framework MOF-Cu2I2(BTTP4) (BTTP4 = benzene-1,3,5-triyl triisonicotinate) was shown to work as an efficiently heterogeneous catalyst for the three-component coupling of sulfonyl azides, alkynes, and amines, leading to the formation of N-sulfonyl amidines in good yields. MOF-Cu2I2(BTTP4) can be recycled by simple filtration and reused at least four times without any loss in yield. Studies of the ligand effects on the three-component coupling reactions showed that BTTP4 could enhance the rate, as well as the chemoselectivity, when aromatic alkynes were employed. The catalytic process has been thoroughly studied by means of single-crystal and powder X-ray diffraction, gas and solvent adsorption, in situ ¹H NMR and FT-IR spectroscopy, X-ray photoelectron spectra (XPS), and ICP analysis of Cu leaching. [ABSTRACT FROM AUTHOR]

A systematic investigation of structural, magnetic, and magnetocaloric properties is reported for a series of monovalent sodium-doped manganites PrSrNaMnO ( x = 0, 0.05, 0.1, 0.15, and 0.2). Rietveld refinements of the X-ray diffraction patterns show that all powder samples are single-phased and crystallized in the orthorhombic structure with Pnma space group. Magnetic characterization and Arrott plot confirm the second-order phase transition at Curie temperature T decreasing from 310 K for x = 0 down to 272 K for x = 0.2. Magnetic entropy change is largest for x = 0 reaching 1.95 J kgK at 2 T field. This corresponds to a large relative cooling power of 102 J kg. Magnetic field sensitivity of magnetic entropy change and relative cooling power are analyzed and discussed. [ABSTRACT FROM AUTHOR]

Uniform ultrasmall monodisperse SrYbF5 and SrErF5 nanocrystals (NCs) were synthesized via solvothermal method using oleic acid as stabilizing agent. Transmission electron microscopy and X-ray diffraction assays reveal that the as-synthesized NCs are of face-centered cubic structure and the cell parameters are 5.608 Å (SrYbF5) and 5.632 (SrErF5) Å. Under the excitation of a 980 nm laser, visible upconversion (UC) emission can be observed by naked eyes in Tm3+ or Er3+ doped SrYbF5 NCs. The integrated intensity of infrared emission is nearly two orders of magnitude stronger than that of the blue emission of SrYbF5:Tm3+ NCs. The energy transfer UC emission mechanisms were also investigated. [ABSTRACT FROM AUTHOR]

Molybdenum-doped indium oxide nanopowders were synthesized via mechanical alloying with subsequent annealing at a relatively low temperature of 600 $^{\circ}$C. The morphologies and crystal structures of the synthesized nanopowders were examined by using scanning electron microscopy (SEM) and X-ray diffraction patterns. X-ray diffraction pattern of the milled mixture shows the presence of both InO phase and Mo element. The presence of broad peaks in the pattern confirms that the synthesized powders are nanosized. The X-ray diffraction of annealed samples at 600 $^{\circ}$C shows the absence of Mo peaks revealing that the Mo was incorporated into the crystal lattices of InO. Interestingly, it was observed that the diffraction peaks were still broad in the annealed samples indicating the single phase at the nanoscale. From the XRD pattern, the calculated crystallite sizes were in the range of 12-18 nm. Magnetic properties of the synthesized Mo-doped InO nanopowders were examined and it was found that the obtained nanopowders possess diamagnetic properties. [ABSTRACT FROM AUTHOR]

Assembly of Zn(NO3)2 with the tripodal ligand H3TCPB (1,3,5-tri(4-carboxyphenoxy)benzene) affords two porous isoreticular metal-organic frameworks, [Zn3(TCPB)2⋅2DEF]⋅ 3DEF ( 1) and [Zn3(TCPB)2⋅2H2O]⋅ 2H2O⋅4DMF ( 2). Single-crystal X-ray diffraction analyses reveal that 1 crystallizes in the monoclinic space group P21/ c and possesses a 2D network containing 1D microporous opening channels with an effective size of 3.0×2.9 Å2, whereas 2 crystallizes in the trigonal space group ${P\bar 3}$ c1 and also possesses a 2D network containing 1D channels, with an effective aperture of 4.0×4.0 Å2. TOPOS analysis reveals that both 1 and 2 have a (3,6)-connected network topology with the Schläfli symbol of (43⋅612) (43)2. According to the variable-temperature powder X-ray diffraction patterns, the solid phase of 1 can be converted into that of 2 during a temperature-induced dynamic structural transformation, thus indicating that the framework of 2 represents the most thermally stable polymorph. Desolvated 2 exhibits highly selective adsorption behaviors toward H2/N2, CO2/N2, and CO2/CH4; furthermore, it displays size-selective catalytic activity towards carbonyl cyanosilylation and Henry (nitroaldol) reactions. [ABSTRACT FROM AUTHOR]

Ag-doped ZnS nanocrystals were synthesized by hydrothermal method in propanetriol solutions. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) characterizations were used to determine the structure and morphology of ZnS: Ag nanocrystals. The as-prepared nanoparticles are approximately spherical with average size around 20~30nm and have a cubic zinc blended structure. The quantum-confined effect of the Ag-doped ZnS nanocrystals is confirmed by the ultraviolet-visible (UV-vis) spectra. The optical properties of ZnS: Ag nanocrystals were investigated by using photoluminescence (PL) spectra, which showed that the products exhibited good optical properties with maximum emission peak at about 460nm, and the intensity of luminescence increased with the increase of concentration of Ag ions. [ABSTRACT FROM AUTHOR]

A manganese(II) coordination polymer [Mn(TMB)2 · H2O] n (1) (HTMB = 3,4,5-trimethoxybenzoic acid) has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, powder X-ray diffraction analysis, spectroscopic (IR, solid state UV-Vis), and thermal methods. The crystal belongs to orthorhombic system, space group P212121, with cell parameters a = 7.3001(8), b = 11.4146(13), c = 27.053(3) Å, α = β = γ = 90°, V = 2254.3(4) Å3, Z = 4. In 1, TMB in two different coordination modes bridges six-coordinate manganese(II) centers forming a 1-D infinite chain coordination framework. The spectral and thermal properties of the complexes have also been studied. [ABSTRACT FROM PUBLISHER]

Piezoelectric ceramics 0.3Pb(NiNb)O-0.7Pb(ZrTi)O (x = 0.42−0.46) were successfully fabricated via the conventional solid-state reaction. XRD demonstrated that the morphotrophic phase boundary (MPB) lay at x = 0.44. The effect of poling condition on the piezoelectric properties of ceramics in the vicinity of MPB was studied by the reserval of domains. The piezoelectric properties at MPB under the optimum poling condition of 2 kV/mm for 10 min in a silicon oil bath at 60 °C were d of 538 pC/N and k of 0.636, respectively. [ABSTRACT FROM AUTHOR]

We report on the sensitive determination of glucose using a glassy carbon electrode modified with CuO nanowires and a Nafion film. The structure and morphology of CuO nanowires were established by scanning electron microscopy and X-ray diffraction. The electrochemical performance of the modified electrode was investigated by cyclic voltammetry and chronoamperometry. Compared to a bare glassy carbon electrode, a substantial increase in efficiency of the electrocatalytic oxidation of glucose can be observed. The new glucose sensor displays two useful linear ranges of response towards glucose, is not affected by commonly interfering species, and displays a detection limit as small as 45 nM. The response time is <2 s towards 0.5 mM of glucose. Additional features include high electrocatalytic activity, high sensitivity, excellent selectivity, and good stability. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The stiffness and bioactivity of polyamide 66 (PA66) have been previously improved by the addition of hydroxyapatite (HA); however, the toughness and processing ability of the HA/PA66 composite need further improvement. In this paper, ethylene-vinyl acetate (EVA) copolymer was used as a modifier to toughen the composite and improve the melt processability. The HA/EVA/PA66 ternary composites were prepared by a twin screw extruder and injection molding, and analyzed by XRD, DSC, SEM, and mechanical testing. The results demonstrate that EVA has good miscibility with a PA66 matrix and result in a uniform distribution of fine HA particles in the composite. With increasing EVA incorporation, the brittle fracture of PA66 and HA/PA66 gradually became ductile fracture. EVA can effectively improve the impact strength and melt processability of the composite; the increased brittleness of HA/PA66 composite by HA addition can be counteracted by incorporation of EVA modifier. The increase in impact strength of the HA/EVA/PA66 composite can be explained on the basis of better stress transfer in the presence of EVA and by finer dispersion of HA particles. [ABSTRACT FROM PUBLISHER]

Three-dimensional leaflike metallic cobalt microcrystals with radiating arrangement from each individual centers were successfully synthesized via a hydrothermal reduction approach. Time-dependent experiments were carried out to verify the rational growth mechanism of the obtained leaflike products, in which a morphology transformation from cobalt hydroxide hexagonal nanoplates to dendritic cobalt crystals and end with leaflike cobalt products was observed. Structure characterizations suggest that this transformation is associated with diffraction-limited aggregation, oriented attachment, and Ostwald ripening. XRD measurement indicates that the cobalt products exhibit a combination of hexagonal-close-packed (hcp) and face-centered-cubic (fcc) crystalline character. The products exhibit a remarkable enhanced coercivity of 193.8 Oe compared against bulk cobalt due to the shape anisotropy and hcp crystalline structure. The effect of different solvents on morphological and magnetic properties of the product was also validated. These leaflike cobalt crystals were further used as substrates to decorate their surface with Ag nanoparticles by transmetallation reaction. These Ag-modified cobalt leaves could have the potential application value in fields of magnetically recyclable catalysts and antibacterial materials. [ABSTRACT FROM AUTHOR]

The title complex {[Yb(1,4-BDC)(HO)]·HO} (1) (1,4-BDC = 1,4-benzenedicarboxylate) has been hydrothermally synthesized and structurally characterized by the single crystal X-ray diffraction. Crystals of compound 1 belongs to the triclinic crystal system, space group P-1; a = 7.549(3) Å, b = 10.072(4) Å, c = 10.470(4) Å, α = 87.810(4)°, β = 82.531(4)°, γ = 86.306(4)°, V = 787.3(5) Å, Z = 2. The Yb(III) atoms are linked by the deprotonated 1,4-BDC ligands in two kinds of bridging modes. Four Yb(III) atoms at each corner (nodes) and four 1,4-BDC ligands at each edge (spacers) form a edge-sharing 36-membered rings. The rhombohedral Yb(1,4-BDC) arranged in an alternating fashion to construct a 1D ladder-like chain along the c axis. Two neighboring chains are linked to each other in a parallel fashion to construct 3D supramolecular structure by O-H···O hydrogen bonds and π- π stacking interactions. In addition, the properties of thermogravimetric analysis and magnetic behaviors of the complex have been also discussed. Graphical Abstract: 1,4-Benzenedicarboxylate-bridged Yb(III) coordination polymer {[Yb(1,4-BDC)(HO)]·HO} was hydrothermally synthesized and characterized structurally. Yb(III) center is linked to three Yb(III) ions via the three 1,4-BDC ligands to form a edge-sharing 36-membered rings. The rhombohedral Yb(1,4-BDC) arranged in an alternating fashion construct a 1D ladder-like chain along the c axis. Magnetic behaviors have been also discussed.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Nanostructured lipid carrier (NLC)-loaded bifendate (DDB) was prepared by melt-emulsification method to improve drug payloads and liver targeting. The particle size of the prepared formulation analysed by photon correlation spectroscopy (PCS) was 217.4 nm with a narrow polydispersity index (PI) lower than 0.2, meanwhile the loading capacity increased from 4.3%% to 15.7%% in comparison with DDB-loaded SLN reported in previous study. The zeta potential value was −−21.91 mV, and transmission electron microscopy studies revealed NLC of irregularly spherical shape. With respect to lipid polymorphism, a less ordered structure of NLC was confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In addition, tissue distribution of DDB-loaded NLC and DDB solution were carried out in Kunming strain mice. In tested organs, the distribution of DDB-loaded NLC to liver was higher than that of free drug. These results support the potential applications of NLC for the delivery of DDB. [ABSTRACT FROM AUTHOR]

Two new coordination polymers, [Zn(H2btc)(4,4'-bpy)2]n (1) and {[Cd(H2btc) (terpy)] · H2O}n (2) (H4btc = biphenyl-2,2',4,4'-tetracarboxylic acid, 4,4'-bpy = 4,4'-bipyridine, terpy = terpyridine), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complexes 1 and 2 are 1-D chains linked through partially deprotonated H4btc. The adjacent 1-D chains of 1 are further formed into 2-D supramolecular architecture through inter-chain N-H···O hydrogen bonds. In contrast, due to a different auxiliary ligand, the 1-D chains of 2 are further extended into 3-D supramolecular framework through inter-chain O-H···O hydrogen bonds. Thermal stabilities and luminescence of 1 and 2 were also studied. [ABSTRACT FROM AUTHOR]

The aim of the present study was to prepare and evaluate microspheres of Eudragit containing an antiviral drug stavudine. Microspheres were prepared by O/O solvent evaporation method using acetone/liquid paraffin system. The prepared microspheres were characterized for their micromeretic properties and entrapment efficiency; as well by Fourier transformed infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and scanning electron microscopy (SEM) which revealed the crystalline nature of drug in a final state. The in vitro studies revealed the controlled release of drug from microspheres up to 12 h and the best fit release kinetics was achieved with a Higuchi plot and found to be diffusion controlled. The yields of preparation and entrapment efficiencies were very high with a larger particle size for all the formulations. Mean particle size, entrapment efficiency and production yield were highly influenced by the type of polymer and polymer concentration. [ABSTRACT FROM AUTHOR]

Copper nanocap arrays, consisting of a SiO2 core with a Cu cap, were prepared by chemical synthesis combined with physical evaporation technique. The obtained samples were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction, and ultraviolet-visible-near-infrared spectrophotometer. The copper nanocap arrays were found to exhibit tunable surface plasmon resonance (SPR) absorption peaks that were red-shifted as the ratio of the SiO2 core diameter to the Cu cap thickness increased. While the cap thickness varied between 20 nm and 50 nm, the SPR peak shifted from 1650 nm to 1230 nm. While the core diameter varied between 140 nm and 400 nm, the longitudinal SPR peak shifted from 1243 nm to 1830 nm. [ABSTRACT FROM AUTHOR]

Structural changes of mechanically activated titanaugite were investigated systematically using X-ray diffraction, particle size analysis, and scanning electron microscopy. The hydrochloric acid leaching behavior of mechanically activated titanaugite and ilmenite single minerals and their mixtures also was studied. The results show that with increasing milling time, the crystallite size, lattice strain, and particle size changed continuously. Mechanical activation evidently improved the leaching reactivity of titanaugite and ilmenite with 20 wt pct HCl at 378 K (105 °C). The leaching behavior of ilmenite was promoted at the initial stage and then was inhibited when mixed with a mass ratio of titanaugite to ilmenite of 1:1. When the mass ratio of titanaugite to ilmenite decreased to 1:9, the leaching of titanaugite was promoted, whereas the leaching of ilmenite was inhibited throughout the whole process. The leaching inhibition of ilmenite is related to the formation of hydrous silicon dioxide from the dissolution of titanaugite. [ABSTRACT FROM AUTHOR]

The effect of cyclic thermal loading on the microstructure and thermoelectric properties of CoSb3 was investigated. The microstructures of the samples were characterized by x-ray diffractometry, scanning electron microscopy, energy dispersive x-ray spectrometry and density measurements. The electrical conductivity, the Seebeck coefficient and the thermal conductivity were measured from room temperature to 800 K. Under cyclic thermal loading, antimony partially volatilized from the surface of the sample, and the density obviously decreased. After 2000 cycles, the phase composition of the sample remained stable, and the average grain size did not change significantly. Moreover, the electrical conductivity varied only slightly, except in the low temperature region. The Seebeck coefficient decreased slightly. However, the thermal conductivity changed remarkably with increasing numbers of thermal cycles. [ABSTRACT FROM AUTHOR]

Niobium-doped ZnO transparent conductive films are deposited on glass substrates by radio frequency sputtering at 300°t. The influence of O2/Ar ratio on the structural, electrical and optical properties of the as-deposited films is investigated by X-ray diffraction, Hall measurement and optical transmission spectroscopy. The lowest resistivity of 4.0x10-4Ω·cm is obtained from the film deposited at the O2/Ar ratio of 1/12. The average optical transmittance of the films is over 90%. [ABSTRACT FROM AUTHOR]

Abstract: Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and –OH groups of n-HA and –NH2 or –OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications. [Copyright &y& Elsevier]

The influence of micelle morphology transformation on the structure of mesoporous materials is fundamental in designing optimal, well-ordered, mesoporous materials. Firstly, the steady-state fluorescence technique was adopted to determine the first and second critical micelle concentrations of cetyltrimethylammonium chloride (CTAC) as 125 and 210 mmol L−1 in an equimolar mixture of water and ethanol at 25°C. Using tetraethylorthosilicate (TEOS) as the precursor, mesoporous silicas (with a surface area of 545.7–1210.5 m 545.7 ∼ 1210.5 m2 g−1 and a pore volume of 0.26 ∼ 0.80 cm3 g−1) were synthesized with the CTAC templates in the equimolar mixture of water and ethanol. Characterization by small-angle X-ray diffraction and N 2 adsorption/desorption techniques revealed that the surface area and pore volume of silica increased with the content of CTAC, whereas there existed a transition point at the CTAC/TEOS ratio of 0.15 corresponding to the fade-away of well-ordered mesoporous structure. The negative effect of the much higher content CTAC on the periodic structure of mesoporous silica is attributed to micelle transformation from spheres to cylinders related to the second critical micelle concentration of CTAC. [ABSTRACT FROM AUTHOR]

A novel ent-atisane lactone, spiramilactone E (1), was isolated from Spiraea japonica var. acutaYu. Its structure was elucidated by extensive spectroscopic analyses, and unequivocally confirmed by single-crystal X-ray diffraction (Fig. 4;2). Compound 1 contains a γ-lactone moiety between the 6-OH function and C(20), and β-configuration for the 7-OH group, in contrast to known related diterpenes previously isolated from the S. japonica complex. [ABSTRACT FROM AUTHOR]

The high undercooling and rapid solidification of Ni-10%Cu-10%Fe-10%Co quaternary alloy were achieved by electromagnetic levitation and glass fluxing techniques. The maximum undercooling of 276 K (0.16TL) was obtained in the experiments. All the solidified samples are determined to be α-Ni single-phase solid solutions by DSC thermal analysis and X-ray diffraction analysis. The microstructure of the a-Ni solid solution phase transfers from dendrite to equiaxed grain with an increase in undercooling, accompanied by the grain refinement effect. When the undercooling is very large, the solute trapping effect becomes quite significant and the microsegregation is suppressed. The experimental measurement of α-Ni dendrite growth velocity indicates that it increases with undercooling according to the relation, V=8x10-2xΔT1,2. [ABSTRACT FROM AUTHOR]

X-ray powder diffraction data, unit-cell parameters and space group for peiminine, C27H43NO3, are reported (a = 30.2026 Å, b = 5.8468 Å, c = 14.4344 Å, β = 96.9456°, unit-cell volume V = 2530.23 Å3, Z = 2 and space group P21). All measured lines were indexed and are consistent with the P21 space group. No detectable impurity was observed. [ABSTRACT FROM PUBLISHER]

X-ray powder diffraction data, unit-cell parameters, and space group for norandrostenedione, C18H24O2, are reported [a = 26.3955(15) Å, b = 8.0476(4) Å, c = 7.3002(3) Å, α = β = γ = 90°, unit-cell volume V = 1550.71 Å3, Z = 4, and space group P212121]. All measured lines were indexed and are consistent with the P212121 space group. No detectable impurity was observed. [ABSTRACT FROM PUBLISHER]

Divalent metal ions were found to trigger the shrinkage of a supramolecular hydrogel based on a peptide dendron, and the shrinkable gel could be further used to control the release of vitamin B1. [ABSTRACT FROM AUTHOR]

X-ray powder diffraction data, unit-cell parameters, and space group for deoxyschisandrin, C24H32O6, are reported [a = 13.083(3) Å, b = 19.563(9) Å, c = 8.805(6) Å, β = 90.472(0)°, unit-cell volume V = 2253.82 Å3, Z = 4, and space group P21]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurity was observed. [ABSTRACT FROM PUBLISHER]

X-ray powder diffraction data, unit-cell parameters, and space group for inclusion complex of β-cyclodextrin with fraxinellone, C42H70O35·C14H16O3·3H2O, are reported [a = 19.294(2) Å, b = 26.639(1) Å, c = 16.467(3) Å, β = 110.451(9)°, cell volume V = 7930.34 Å3, Z = 4 and space group C2]. All measured lines were indexed and are consistent with the C2 space group. No detectable impurities were observed. [ABSTRACT FROM PUBLISHER]

Zinc sulphide nanoparticles were prepared by a simple biomolecule-assisted biomimetic method at room temperature. X-ray diffraction pattern confirmed the formation of a cubic zinc blende phase of ZnS nanocrystals. Transmission electron microscopy images revealed that the nanoparticles are nearly spherical in shape, with average diameter about 40 nm. The optical property of ZnS nanoparticles was studied by the ultraviolet-visible spectrum. Different template concentrations of lysozyme are used to investigate the influence of biomolecule on the formation of nanoparticles. Fourier transform infrared spectroscopy study suggested ZnS nanoparticles can react with functional groups of lysozyme including -OH and -NH. [ABSTRACT FROM AUTHOR]

Polymorphic transformation mechanism of η and η′ in single crystalline Cu6Sn5 has been investigated in this study. η phase exists at room temperature in the quenched specimens and transforms to η′ phase under aging at 150 °C for 40 d. The nucleation and growth of η′ phase is observed by field emission scanning electron microscope and surface reconstruction of polymorphic transformation is confirmed by both x-ray diffractometer and differential scanning calorimetry analysis. The results show that the volumetric strain energy is the dominant reason for occurring polymorphic transformation rather than order-disorder transition of η and η′ phases. [ABSTRACT FROM AUTHOR]

(Sp)-1-vinyl-2-diphenylhydroxyl-methylferrocene was synthesized via a new method except the classical synthetic method and identified by 1H NMR and MS. The structure of title compound was determined by X-ray crystallography. Single crystal X-ray diffraction analysis reveals that the molecular structure of the title compound is Triclinic, P-1 space group, a=9.0388(18) Å, b=9.6024(19) Å, c=12.195(2) Å, α=84.98(3)°, β=73.19(3)°, γ=72.38(3)°; V=965.7(3) Å3, Dx=1.356 g cm-3, Z=2, T=293(2)K. Extinction coefficient is 0.0077(18). [ABSTRACT FROM AUTHOR]

Florfenicol (FF) is a novel animal-specific amidohydrin broad-spectrum antibiotic. However, its aqueous solubility is extremely poor, far below the effective dose required for veterinary clinic. Thus, FF is often used in large doses, which significantly limits its preparation and application. To overcome these shortcomings, the FF-hydroxypropyl-β-cyclodextrin (FF-HP-β-CD) inclusion complexes were developed using the solution-stirring method. The physical properties of FF-HP-β-CD were characterized. A comparison was conducted between FF and FF-HP-β-CD freeze-dried powder injection of their muscle irritation and the pharmacokinetics. The drug loading and saturated solubility of FF-HP-β-CD at 37 °C were 11.78% ± 0.04% and 78.93 ± 0.42 mg/mL, respectively (35.4-fold compared with FF). Results of scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared showed that FF was entrapped in the inner cavity of HP-β-CD, and the inclusion complex formed in an amorphous state. In comparison with FF commercial injection, FF-HP-β-CD increased the elimination half-life (t1/2β), transport rate constant (K10, K12, K21), and maximum concentration (Cmax) after intramuscular injection in beagle dogs. Conversely, it decreased the distribution half-life (t1/2α), absorption rate constant (Ka), apparent volume of distribution (V1/F), and peak time (Tmax). These results suggest that FF-HP-β-CD freeze-dried powder injection is a promising formulation for clinical application. [ABSTRACT FROM AUTHOR]

Inorganic metal oxide nanoparticles of zinc, copper and iron have been widely studied for their use in biomedical research due to their novel physical, chemical and biological properties. Present work involves studies on copper oxide nanoparticles for their antibacterial activity. Copper oxide (CuO) nanoparticles were synthesized by template-free hydrothermal synthesis using different precursors of copper (nitrate, acetate, chloride and sulphate). The samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, ultraviolet-visible (UV-Vis) absorption spectroscopy, scanning electron microscopy (SEM) and zeta potential analysis. The XRD patterns of the synthesized samples show presence of (−111) and (111) planes, which can be assigned to the monoclinic phase of CuO with the average crystallite size ranging between 43 and 49 nm. The SEM reveals rod-shaped morphology of the samples with a broad size distribution. The optical band gap calculated by UV-Vis absorption study ranges between 1.35 and 1.38 eV. The highly negative zeta potential values of the CuO synthesized with nitrate (−23.78 ± 0.95 mV), acetate (−11.86 ± 1.06 mV) and sulphate (−22.33 ± 0.85 mV) precursors of copper reveal the good colloidal stability of the synthesized particles. While CuO synthesized with copper (II) chloride shows intermediate stability with the zeta potential as 9.40 ± 1.86 mV. The antibacterial activity of the synthesized CuO was studied against human pathogens like Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacterial strains, which are proved to be efficient and precursor-dependent. The minimum inhibitory concentration of CuO against E. coli and S. aureus were found to be 0.15 and 0.1 mg ml-1, respectively. CuO nanoparticles exhibit good antibacterial activity, hence, it has potential for biomedical applications in preventing and treating infections. [ABSTRACT FROM AUTHOR]

Novel asymmetric bismaleimide (BMI) oligomers with different molecular weights and dianhydrides were designed and synthesized by 3,4'-oxydianiline (3,4'-ODA), 2,3,3,4-oxydiphthalic dianhydride (a-ODPA), and 2,3,3',4 biphenyltetracarboxylic dianhydride (a-BPDA). The chemical structures of BMI oligomers were confirmed by Fourier transform infrared spectrometry (FTIR) and gel permeation chromatography (GPC). X-ray diffraction (XRD) exhibited broad peaks, suggesting amorphous structures. Heat flow curves of oligomers measured by differential scanning calorimeter (DSC) displayed wide processing window due to low glass transition temperatures ([T.sub.g]). BMI oligomers exhibited high solubility in common organic solvents. Particularly, the OD-BMI-1 oligomer exhibited excellent solubility of more than 50 wt% in DMAc solvent. [T.sub.g] value and minimum complex viscosity of OD-BMI-1 oligomer were only 121[degrees]C and 8.1 Pa s, respectively. The cured BMI resins possess high thermal and thermaloxidative stability. The [T.sub.g] and the temperature of 5% weight loss in nitrogen were above 256 and 449[degrees]C, respectively, and the residual weight percentages at 800[degrees]C were all >49%. Moreover, films made of BMI resins exhibited excellent mechanical properties flexibility, as confirmed by photograph and DMA results of films. The elongation at break of the prepared films was found to be high (almost >9.6%)., INTRODUCTION Bismaleimide (BMI) resins are important class of high performance thermosetting polymers. They are employed as base resins in advanced composites and printed circuit boards due to their high performance-to-cost [...]