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Shuttle-shaped, porous copper oxide (CuO) microparticles were prepared from Cu(OH)2 in a water/cyclohexane interfacial reaction followed by heat treatments at different temperatures. The CuO catalysts produced high catalytic activity and good durability for hydrazine oxidation reaction (HOR). Among all catalysts, CuO catalyst heat treated at 200°C provided the highest HOR activity with an onset potential of -0.204 V and a high oxidation peak current density of 0.87 mA cm-2 of HOR. HOR performances of the CuO catalysts correlated to their porous structure and transition of different Cu species. These findings shed light on factors influencing HOR activity of CuO catalysts. [ABSTRACT FROM AUTHOR]

We herein demonstrate the use of 1,3-di(2-dipyridyl)propan-1,3-dione (DPPD) as a fluorogenic label for oligosaccharides. A number of milk-derived oligosaccharide standards were successfully labeled with this reagent, with the advantage of greatly simplified sample preparation compared to other commonly used fluorescent tags. DPPD shows a selectivity for oligosaccharides which do not possess a 2-acetamido-2-deoxy-hexose moiety at the reducing terminus, potentially aiding in the identification of complex mixtures of carbohydrates. The use of DPPD for the structural determination of oligosaccharides through exoglycosidase treatment, quantitative analysis of reactions, and in the synthesis of labeled oligosaccharides was also explored. This reagent has, in addition to the analysis of individual and mixed oligosaccharides, potential applications in the study of glycosidases and glycosyltransferases and as such represents a valuable addition to the tools available to the glycoscientist. [ABSTRACT FROM AUTHOR]

Herein, a single luminophor dual-potential chemiluminescence (ECL) system based on nitrogen doped graphene quantum dots (NGQDs) was developed for ratiometric detection of Co 2+ ion. Dissolved oxygen is changed to O 2 − and HO 2 − which participate in the anodic and cathodic ECL generating processes of NGQDs. Co 2+ ion was demonstrated able to evidently amplify the anodic intensity by displaying catalytic action of the intermediate steps of anodic ECL reactions, and quench the cathodic ECL intensity because of the effective elimination on excited states (NGQDs*) generating. Hence, the target Co 2+ ion could be quantified by the ratio of ECL intensities at two excitation potentials. On this basis, without any labeling and additional coreactants, an accurate and reliable sensing system based on the dual-potential ECL of NGQDs toward Co 2+ ion was fabricated with excellent sensitivity and selectivity against other interferential metal ions. The developed ratiometric sensor exhibited a linear response ranging from 1.0 μM to 70 μM with a limit of detection of 0.2 μM ( S/N = 3 ). The proposed dual-potential ratiometric NGQDs based ECL sensor was also used to detect Co 2+ ion in real water samples. As single luminophor, NGQDs possessing multiple-ECL signals is simple without labeling, providing more reliable signals in sensing than other essential state dependent techniques. [ABSTRACT FROM AUTHOR]

A highly efficient and effective method for the synthesis of N-unsubstituted 4-aryl-1,2,3-triazoles promoted by Amberlyst-15 is described. The promoter can be recycled and reused up to eight times without any reduction in its catalytic activity. [ABSTRACT FROM AUTHOR]

The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP–AES, XRD, TG-DSC, SEM–EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na 6 CaAl 6 Si 6 (CO 3 )O 24 ·2H 2 O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH·H 2 O and Na 2 Ca(CO 3 ) 2 were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol. [ABSTRACT FROM AUTHOR]

In this study, a novel electro-Fenton (EF) system was developed with iron wire, activated carbon fiber, and sodium tetrapolyphosphate (Na6,TPP) as the anode, cathode, and electrolyte, respectively. This Na6TPP-EF system could efficiently degrade atrazine in a wide pH range of 4.0-10.2. The utilization of NaftTPP instead of Na2S04 as the electrolyte enhanced the atrazine degradation rate by 130 times at an initial pH of 8.0. This dramatic enhancement was attributed to the formation of ferrous-tetrapolyphosphate (Fe(Π)-TPP) complex from the electro- chemical corrosion (ECC) and chemical corrosion (CC) of iron electrode in the presence of NaftTPP. The Fe(II)-TPP complex could provide an additional molecular oxygen activation pathway to produce more H202 and ∙OH via a series single-electron transfer processes, producing the Fe(ш)-TPP complex. The cycle of Fe(Π)/Fe(ш) was easily realized through the electrochemical reduction (ECR) process on the cathode. More interestingly, we found that the presence of Na6TPP could prevent the iron electrode from excessive corrosion via phosphorization in the later stage of the Na6TPP-EF process, avoiding the generation of iron sludge. Gas chromatograph-mass spectrometry, liquid chromatography-mass spectrometry, and ion chromatography were used to investigate the degradation intermediates to propose a possible atrazine oxidation pathway in the Na6PP-EF system. These interesting findings provide some new insight on the development of a low-cost and highly efficient EF system for wastewater treatment in a wide pH range. [ABSTRACT FROM AUTHOR]

Four new hexavanadate cluster-based hybrid materials [Ni(3-atrz)2V2O6]·2H2O (1) and [M3(4-atrz)6V6O18]·4H2O [atrz = amino-1,2,4-triazole; M = Ni (2), Co (3) and Zn (4)] have been synthesized under hydrothermal conditions by the reaction of transition metal salts, amino-triazole ligands and sodium metavanadate. Single crystal X-ray diffraction analyses reveal that compound 1 shows a one-dimensional (1D) chain formed by the alternative arrangement of linear trinuclear complexes [Ni3(3-atrz)6]6+ and hexanuclear [V6O18]6- clusters. Compounds 2-4 are isostructural three-dimensional (3D) frameworks, which are constructed from the linear trinuclear transition metal complexes and 2D inorganic layers derived from transition metal ions and hexanuclear [V6O18]6- clusters. The distinct amino positions in the two types of triazole ligands play the key role in determining the final dimensionality and structures of the title compounds. The thermal stability, photocatalytic activity and magnetic properties of 1-4 have been investigated. [ABSTRACT FROM AUTHOR]

A model based on the statistics of individual atoms [Europhys. Lett. 94 (2011) 40002], which has been successfully applied to predict the rate constant of unimolecular reactions, was further extended to bimolecular reactions induced by collisions. Compared with the measured rate constants of the reactions S+SO2 →SO+SO and NH3+Cl→NH2+HCl, the model is proved to be significantly better than conventional transition state theory. In order to strictly test the model, we perform molecular dynamics simulation of C60+C60→C120, and show that the rate constants are in excellent agreement with our model but far away from the transition state theory [ABSTRACT FROM AUTHOR]

Janus kinase 1/signal transducers and activators of transcription 3 (JAK1/STAT3) pathway is one of the recognized oncogenic signaling pathways that frequently overactivated in a variety of human tumors. Despite rapid progress in elucidating the molecular mechanisms of activation of JAK/STAT pathway, the processes that regulate JAK/STAT deactivation need to be further clarified. Here we demonstrate that CUE domain-containing 2 (CUEDC2) inhibits cytokine-induced phosphorylation of JAK1 and STAT3 and the subsequent STAT3 transcriptional activity. Further analysis by a yeast two-hybrid assay showed that CUEDC2 could engage in a specific interaction with a key JAK/STAT inhibitor, SOCS3 (suppressors of cytokine signaling 3). The interaction between CUEDC2 and SOCS3 is required for the inhibitory effect of CUEDC2 on JAK1 and STAT3 activity. Additionally, we found CUEDC2 functions collaboratively with SOCS3 to inhibit JAK1/STAT3 signaling by increasing SOCS3 stability via enhancing its association with Elongin C. Therefore, our findings revealed a new biological activity for CUEDC2 as the regulator of JAK1/STAT3 signaling and paved the way to a better understanding of the mechanisms by which SOCS3 has been linked to suppression of the JAK/STAT pathway. [ABSTRACT FROM AUTHOR]

The biosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, cost-effective and environmentally friendly technologies for nano-materials synthesis. In this report, silver nanoparticles (AgNPs) were synthesized using a reduction of aqueous Ag+ ion with the culture supernatants of Aspergillus terreus. The reaction occurred at ambient temperature and in a few hours. The bioreduction of AgNPs was monitored by ultraviolet-visible spectroscopy, and the AgNPs obtained were characterized by transmission electron microscopy and X-ray diffraction. The synthesized AgNPs were polydispersed spherical particles ranging in size from 1 to 20 nm and stabilized in the solution. Reduced nicotinamide adenine dinucleotide (NADH) was found to be an important reducing agent for the biosynthesis, and the formation of AgNPs might be an enzyme-mediated extracellular reaction process. Furthermore, the antimicrobial potential of AgNPs was systematically evaluated. The synthesized AgNPs could efficiently inhibit various pathogenic organisms, including bacteria and fungi. The current research opens a new avenue for the green synthesis of nano-materials. [ABSTRACT FROM AUTHOR]

Abstract: At B3LYP method of density functional theory with 6-31+G(d) basis set, the reaction mechanism of dimethyldiazene was studied, which is an important intermediate product of UDMH and •OH. All transition states are characterized by one imaginary frequency on the PES. Intrinsic reaction coordinate (IRC) is proceeded to confirm transition states connecting the designated local minima. On the basis of the vibrational calculation, we get the energy curve of the reaction. [Copyright &y& Elsevier]

Abstract: In this work, the upgrading reactions of high-boiling fraction (HBF) of bio-oil were carried out over a series of supported mono- and bi-metallic catalysts under the supercritical methanol condition. During these reactions, esterification and cracking (alcoholysis and hydrocracking) were the two dominant processes. PtNi/MgO exhibited good performance, and gave a high yield (72.4wt.%) of refined oil. The acid–base properties of the supports have an important effect on the coke deposition on the catalyst surface. The acidic catalysts gave the somewhat lower product yields, but tended to inhibit coking reaction. This would improve the life of the catalysts in the practical applications. The refined oil is believed to be a potential substitute or partial substitute for the fossil transportation fuel. [Copyright &y& Elsevier]

A novel multiblock poly(ester urethane) (PBESTU) was synthesized through chain-extension reaction of hydroxyl-terminated poly(butylene succinate) (PBS−OH) and poly(ethylene succinate-co-ethylene terephthalate) (PETS−OH), using toluene-2,4-diisocyanate (TDI) as chain extender. The chemical structure and molecular weight of PBESTUs were characterized by 1H NMR, intrinsic viscosity, and GPC. The thermal behaviors were investigated by DSC and TGA. The resulting copolymers, PBESTUs, have a sole glass transition temperature (Tg), which indicated that the two segments, PETS and PBS, were well compatible in the amorphous phase. PETS segment enhanced the thermal degradation temperature of PBESTUs. The DSC and WAXD results showed that PBS segment made great contribution to the crystallization of PBESTUs. PBESTUs possessed excellent mechanical properties according to tensile testing. [ABSTRACT FROM AUTHOR]

A very efficient NHC-catalyzed lactamization reaction is reported. For most cases, the ring expansion reaction proceeds to cleanly furnish five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. Evidence is presented suggesting a dual role for the stoichiometric base: (1) deprotonation of the triazolium precatalyst and (2) activation of the nitrogen leaving group through hydrogen bonding. [ABSTRACT FROM AUTHOR]

A composite based on polyvinyl alcohol PVA and gelatin Gel was prepared in the form of a miscible interphase by freezingthawing method using vanillin as a new compatilizer. The chemical and physical properties of PVAGelvanillin composite hydrogels with different reagent concentration, and reaction time were investigated using Fourier transform infrared spectroscopy FTIR, differential scanning calorimetry DSC, tensile testing, and scanning electron microscopy SEM. The results elicit that the formation of CN Schiff base between Gel and vanillin may break the intrahydrogen bonding of Gel. Proper reaction time and more interactive groups result in optimal interhydrogen bonding between modified Gel and PVA so that the miscibility between two polymers has been improved. In addition, the PVAGelV composite with the vanillin concentration of 0.20 gmL and 2 h stirring exhibits a better compatibility and a higher tensile strength, which can be tailored for potential use in cartilage tissue engineering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

We have developed a Pt(COD)Cl2-catalyzed hydrative cyclization of 1,6-diynes leading to the formation of functionalized cyclohexenones in good yields. [ABSTRACT FROM AUTHOR]

The spherical cleavage behavior of polydivinylbenzene (PVDB) during suspension polymerization was investigated by changing experimental conditions, such as porogen amount, porogen type and stirring speed. The results indicated that the possibility of spherical cleavage is high when the volume ratio of porogen and divinylbenzene exceeds 1.0. Based on the experimental results, we speculated that high cross-linking density and inhomogeneous shear force induced by unstable stirring may be responsible for cleavage behavior of PDVB microspheres. [ABSTRACT FROM AUTHOR]

Large-scale uniform ZnO dumbbells and ZnO/ZnS hollow nanocages were successfully synthesized via a facile hydrothermal route combined with subsequent etching treatment. The nanocages were formed through preferential dissolution of the twinned (0001) plane of ZnO dumbbells. Due to their special morphology, the hollow nanocages show better sensing properties to ethanol than ZnO dumbbells. The gain in sensitivity is attributed to both the interface between ZnO and ZnS heterostructure and their hollow architecture that promotes analyte diffusion and increases the available active surface area. [ABSTRACT FROM AUTHOR]

The molecular combing technique was used to dissociate the nanostructural units of starch granules from the starch fragments after a gelatinization process. With the help of atomic force microscopy (AFM), we observed that some nanostructural chains were just flowing out of the granules. It proves that there are substantive nanostructural units in the starch granules, a phenomenon not previously observed, so these nanostructural units were defined as suspected intermediates. Furthermore, we conclude that blocklets of starch granules are formed through twisting or distortion of nanochains. [ABSTRACT FROM AUTHOR]

A novel 3,8-diimidazol-l,10-phen (phen = phenanthroline) compound has been prepared from the carbon-nitrogen bond cross-coupling reaction. X-ray structural studies for this compound and its dihydrate reveal they have different molecular conformations (Lb in 1 and Lc · 2H2O in 2). TWO cadmium(II) and one zinc(II) complexes of 3,8-diimidazol-1,10-phen, formulated as [Cd2(D-cam)2(La)2] ·(H2O)6 (3), [Cd2(D-cam)2(La)(H2O)] (4), and [Zn2(D-cam)2(Lb)2] · (H2O)5 (5), have been obtained involving an auxiliary chiral ligand D-cam (a dianion of D-camphoric acid) where the 3,8-diimidazol-l,10-phen ligand shows different molecular conformations, coordination modes, and architectures, Furthermore, D-cam and 3,8-diimidazel-l,10-phen ligands exhibit different bridging fashions to construct a homochiral 2D coordination polymer 3 and two homochiral 3D coordination polymers 4 and 5. Density function theory computational studies on comparing the different molecular conformations of the 3,8-diimidazol-l,10-phen ligand as well as spectral, nonlinear optical, and thermal properties for related compounds before and after the metal-ion complexation have also been carried out. [ABSTRACT FROM AUTHOR]

Much effort has been directed at understanding the roles of metal ions in catalyzing the hydrolysis of phosphodiester bonds of nucleic acids. Nucleases are metalloenzymes that have a wide variety of active site motifs and that contain a variety of different metal ions. This property has made it difficult to propose a simple mechanism for these enzymes. Therefore, design and synthesis of metal complexes, which can mediate phosphodiester bond cleavage viahydrolytic pathways, are of important significance in elucidation of the catalytic mechanisms for the natural nucleases and in development of the biomacromolecule-targeted drugs. Recent progress has extended to the design of synthetic multinuclear metallonucleases containing two or more Fe(iii), Zn(ii), Cu(ii), Co(ii/iii), or Ln(iii/iv) ions. The ligands in these complexes include natural and nonnatural organic molecules, i.e., mainly benzimidazolyl- and pyridyl-based organic molecules, azamacrocyclic and aminocarboxylic derivatives, and their conjugates to polypeptides or oligonucleotides. The purpose of this perspective is to highlight: (1) the differences in structure and composition between natural and synthetic multinuclear metallonucleases; (2) the design strategies of synthetic multinuclear metallonucleases; (3) the relationship between the structures and nucleolytic activities of synthetic multinuclear metallonucleases; and (4) the cooperativities between metal sites, and between metal sites and ligands in the courses of phospodiester linkage hydrolysis. A comparison illustrates unifying themes in the catalysis of phosphodiester linkage hydrolysis by natural and synthetic multinuclear metallonucleases. Indeed, there are features that converge about the chemistry that provides insight into how changes in metal ions and ligands of both natural and synthetic metallonucleases may lead to the same overall outcome of phosphodiester backbone cleavage. In addition, we will also discuss the solvation effect of synthetic multinuclear metallonucleases and the challenges that should be faced toward the development of synthetic multinuclear metallonucleases with DNA sequence or structure selectivity by applying the principles of coordination and enzymatic chemistry. [ABSTRACT FROM AUTHOR]

We present here a synchrotron-based photoemission spectroscopy (PES) study of the organic functionalization of bare single crystalline diamond C(100) 2 × 1 surface with an organic semiconductorcopper phthalocyanine (CuPc). Our results reveal that CuPc undergoes chemical reactions with the bare diamond surface by covalently bonding to diamond dimers. The functionalizing molecules induce an interface dipole layer that increasingly reduces the work function and electron affinity of diamond with increasing CuPc coverage, transforming bare diamond from a positive electron affinity to a negative electron affinity (NEA) surface. Meanwhile, a significantly enhanced secondary electron emission yield accompanied the reduced electron affinity, as a result of the lowered electron emission barrier and enhanced electron conduction from diamond to vacuum through the grafted molecules. The work function and electron affinity modulation contributed by the induced interface dipole is estimated to be 0.7 eV, on top of the band bending contributions. Our results highlight the utilization of organic semiconductor molecular functionalization as a means to tailor the surface electronic properties of diamond and other conventional inorganic semiconductors. The unique combination of NEA, high electron emission, and organic semiconductor functionality on diamond could lead to the integration of molecular electronic function with diamond devices. [ABSTRACT FROM AUTHOR]

The discrepancies in inclusion characteristics and localized corrosion behaviour and mechanism induced by inclusions in DSS2101 are contrastively investigated. We found that the two types of inclusions consisted of (Al, Mn, Cr)–O–S and (Ce, Al, Mn)–O–S. Numerous twins and denser entangled dislocations were distributed near the (Al, Mn, Cr)–O–S/matrix. The distorted and normal BCC phase exhibited the { 1 ‾ 10 } N ∥ { 1 ‾ 12 } D orientation relationship, whereas severe lattice expansion existed along the { 0 1 ‾ 2 } and { 1 ‾ 20 } crystallographic directions, presumably resulting in the priority initiation of pitting. Besides, the (Al, Mn, Cr)–O, (Al, Mn)–O core and CeAlO 3 shell had especially poor electrical conductivity, making formation of the galvanic couple difficult. However, the deformed matrix served as an anode relative to the normal matrix (as a cathode), facilitating pitting rate of Ce-free steel. In contrast, the electrochemical reaction of MnS (as an anode) and the chemical reaction of the CeAlO 3 shell protected the adjacent matrix (as a cathode) from erosion by self-dissolution in Ce-modified steel. The synergistic effect of the differential aeration cell (DAC) and occluded corrosion cavity (OCC) was supposed to deteriorate the microcrevice corrosion and galvanic corrosion. • Correlation of the hyperfine structure of inclusions and pitting was studied. • Both types of inclusions were characterized by FIB-SEM, HRTEM and AFM in DSS2101. • Pitting initiated by deformed matrix /microcrevices around (Al, Mn, Cr)-O-S. • Chemical reaction of CeAlO 3 shell protected the adjacent matrix by self-erosion. • Pitting mechanisms associated with selective dissolution and galvanic corrosion. [ABSTRACT FROM AUTHOR]

Selective leaching of vanadium and separation of iron from red mud by using oxalic acid and sodium sulfite were put forward. The main influencing factors of selective leaching were studied and the leaching mechanism was analyzed with XRD, SEM-EDS, thermodynamic theory and leaching kinetics. The results show that more than 90% of vanadium could be selectively leached into the acid solution with less than 10% of iron under the suitable leaching conditions. The acid leaching of vanadium is controlled by boundary layer diffusion with R2 more than 0.98. The acid leaching of iron is controlled by surface chemical reaction with R2 more than 0.99 under different oxalic acid concentrations. The apparent activation energy of vanadium and iron was 8.21 kJ/mol and 13.57 kJ/mol, respectively. H 2 C 2 O 4 could selectively destroy the minerals of red mud resulted in the high recovery of vanadium. H 2 C 2 O 4 reacted with Fe2+ to generate the precipitation of FeC 2 O 4 in the leaching residue caused by the p-π conjugation of O--C--O of C 2 O 4 2-. The stable VO(C 2 O 4) 2 2- complex was present in the leaching solution due to the conjugated system of π-π with O--C--O of C 2 O 4 2- and V˭O of VO2+. Possible selective leaching mechanism of vanadium and iron from red mud with H 2 C 2 O 4. [Display omitted] • Selective leaching of vanadium with H 2 C 2 O 4 and Na 2 SO 3 from red mud was achieved. • Selective leaching process of vanadium and iron was detected by XRD and SEM-EDS. • Leaching behaviors of V and Fe were comparatively investigated by leaching kinetics. • Separation mechanism of V and Fe was analyzed by the solution thermodynamics. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the solid-state reactions between CaCu3Ti4O12 and ZnNb2O6 oxides with a molar ratio of 1:1 in air at temperatures from 600 to 1000°C. Solid-state reactions between CaCu3Ti4O12 and ZnNb2O6 occurred readily around 900°C and above. The reaction products were Cu0.5Ti0.5NbO4, CaNb2O6, and Zn2TiO4 (and/or ZnCuTiO4). A substance having a set of X-ray diffraction peaks similar to that of CaCu3Ti4O12 was observed, and it is believed to be a solid solution of CaCu3Ti4O12 formed by the partial substitution of Nb5+ for Ti4+ ions. The lattice constant of this solid solution is greater than that of CaCu3Ti4O12. The reaction behaviors of CaCu3Ti4O12–Nb2O5 system were also studied in order to better understand the reactions of the CaCu3Ti4O12–ZnNb2O6 system. In addition to the formation of solid solution between CaCu3Ti4O12 and Nb2O5, solid-state reactions between CaCu3Ti4O12 and Nb2O5 also occurred simultaneously. [Copyright &y& Elsevier]

MgCl2/AlCl3-supported Ziegler–Natta catalysts were prepared using the one-pot milling method and low isotactic polypropylene was synthesized using this catalyst. The results indicated that higher Ti content in catalyst and higher polymerization temperature lead to higher isotactic index of resultant polypropylene. It was found that when Ti content was 1.2 wt% and the ratio of AlCl3/MgCl2 (mol/mol) was 0.1 in MgCl2/AlCl3-supported Ziegler–Natta catalyst, the activity of catalyst was highest at 30°C. [ABSTRACT FROM AUTHOR]

A series of salicylanilides (la-h) bearing varied substituents at the 3′- or 4′-position of the anilino moiety (substituent p-OCH3, p-CH3, m-CH3, H, p-Cl, m-Cl, p-CO2CH3, and p-CN) were synthesized. In acetonitrile all of the substituted salicylanilides 1aߞh predominantly adopt the "closed-ring" conformation facilitated by a strong intramolecular OWߪOC hydrogen bond. In the presence of H2PO4, the conformation of 1aߞh was found to be modulated by the substituent. With our proposed proton- transfer fluorescence probing method, we were able to show that the conformation of la-f bearing a not highly electron-withdrawing substituent was switched to the "open-ring" form by H2PO4, whereas 1h bearing a highly electron-withdrawing substituent, p-CN, remained in the "closed-ring" conformation. The significance of these findings for understanding, from a molecular structural point of view, the mechanism of salicylanilide-based inhibitors for inhibiting the protein tyrosine kinase epidermal growth factor receptor was discussed. [ABSTRACT FROM AUTHOR]

Silver-poly(methyl methacrylate) (Ag/PMMA) nanocomposites were successfully synthesized by bi-in situ ultrasonic radiating the emulsion containing methyl methacrylate (MMA) monomer and silver nitrate; no initiator or reductant in this method. The resultant Ag/PMMA nanocomposites were charazcterized by infrared spectroscopy, high resolution transmission electron microscopy, and X-ray diffraction. The results revealed that nanosilver as core within the composites particles were uniform polycrystallines. The thermoanalysis of the nanocomposites showed that the nanosilver within the nanocomposites possessed the effect of the small dimension. The experimental factors such as systemic temperature, the concentration of the silver nitrate, and contents of MMA on the final conversion of monomer were also discussed. It is interesting that the polymerization can be promoted by silver clusters. [ABSTRACT FROM AUTHOR]

Pristine carbon black was oxidized with nitric acid to produce carboxyl group, and then the carboxyl group was consecutively treated with thionyl chloride and glycol to introduce hydroxyl group. The hydroxyl group on the carbon black surface was reacted with 2‐bromo‐2‐methylpropionyl bromide to anchor atom transfer radical polymerization (ATRP) initiator. The ATRP initiator on carbon black surface was verified by TGA, FTIR, EDS, and elemental analysis. Then, poly (methyl methacrylate) and polystyrene chains were respectively, grown from carbon black surface by surface‐initiated atom transfer radical polymerization (SI‐ATRP) using CuCl/2,2‐dipyridyl (bpy) as the catalyst/ligand combination at 110 °C in anisole. 1H NMR, TGA, TEM, AFM, DSC, and DLS were used to systemically characterize the polymer‐grafted carbon black nanoparticles. Dispersion experiments showed that the grafted carbon black nanoparticles had good solubilities in organic solvents such as THF, chloroform, dichloromethane, DMF, etc. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3451–3459, 2007 [ABSTRACT FROM AUTHOR]

Pure exo‐functional norbornene monomers containing various chromophores such as fluorene, pyrene, and carbazole were successfully prepared via the Diels–Alder reaction and condensation reaction. The living ring‐opening metathesis polymerization (ROMP) of a fluorene‐containing monomer, exo‐2‐(fluorene‐9‐ylcarboxymethyl)norborn‐5‐ene (exo‐1), was observed and confirmed by the formation of a diblock copolymer and a linear relationship between the number‐average molecular weight and [M]/[I] ratios ([M] = monomer concentration; [I] = initiator concentration). The synthesis and characteristics of novel fluorene‐containing polymers based on pure exo‐1 are reported with Grubbs catalyst I {RuCl2(CHPh)[P(C6H11)3]2} with a high molecular weight of 3.18 × 104 in 90 s ([M]/[I] = 100). However, the ROMP of pyrene‐ and carbazole‐containing monomers [exo‐5‐(pyrene methoxy carbonyl)bicyclo[2.2.1]hept‐2‐ene and exo‐5‐(carbazole ethoxy carbonyl)bicyclo[2.2.1]hept‐2‐ene, respectively] were carried out in a nonliving fashion. All the chromophore‐containing polymers showed excellent solubility in various organic solvents, particularly in chloroform, N‐methyl‐2‐pyrrolidinone, and 1,2‐dichlorobenzene. The glass transition temperatures of polynorbornenes containing various chromophores were determined to be 80–109 °C (by differential scanning calorimetry) higher than that of ring‐opened polynorbornene (glass transition temperature = 35 °C), indicating that the incorporation of the pendant aromatic moieties (e.g., fluorene, pyrene, and carbazole) could enhance the transition temperature for segmental motions of polymer chains. The photoluminescence spectra of all polymer solutions showed a strong emission in the blue region of the visible spectra. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3022–3031, 2007 [ABSTRACT FROM AUTHOR]

The aim of this study is to improve the anticorrosive property of 7Cu3Zn brass. The methyl‐methacrylate (MMA) monomer solution, modified with fluorine radical and silicone, was used as the polymer matrix to mix with the different percentages of modified montmorillonite (MMT) loading and to exfoliate the lamellar structure of MMT on a nanometer scale during the solution polymerization process, and then form a thin nanocomposites coating on brass as a protective layer. The structural characterization was examined using Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), and transmission electron microscope (TEM). The anticorrosive property of nanocomposites was evaluated using potentiodynamics polarization and electrochemical impedance spectra. The results show that the d‐spacing of MMT was increased, and both exfoliation and intercalation microstructure were observed. Moreover, with the MMT loading increase, the appearance of the intercalation microstructure was more remarkable as a result of silicate layers aggregation. The 1.0 wt %‐coated brass coupons presented the optimistic property of anticorrosion, whose oxygen permeability, corrosion current (icorr), polarization resistance (Rp), and corrosion rate (Rcorr) were 3.5 g/(m2°h), 6.86 nA/cm2, 5.81 × 105 Ω°cm2, and 0.103 × 10−3 mm/year, respectively. These results indicate that nanocomposites have potential for anticorrosion application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4135–4143, 2007 [ABSTRACT FROM AUTHOR]

The hydroxy methyl groups were introduced onto the pristine carbon black surface through the reaction between unsaturated hydrogen atoms of the polycondensed aromatic rings of carbon black and formaldehyde in alkali condition. Using the resultant hydroxy methyl groups on the carbon black surface as the growth point, multihydroxyl hyperbranched polyether was grafted onto the carbon black surface by cationic ring‐opening polymerization of 3‐ethyl‐3‐(hydroxymethyl)‐oxetane in the presence of BF3·OEt2 to improve its dispersion ability in solvents. It was found that the modified carbon black could be dispersed in polar solvents, such as ethanol, chloroform, and DMF. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2086–2092, 2007 [ABSTRACT FROM AUTHOR]

In this paper, we synthesized epoxy resin/CaCO 3 nanocomposites through in-situ and inclusion polymerization, and the nanoparticles were well dispersed in the resin matrix observed by SEM. The effects of the nanoparticles on the properties of epoxy resin are discussed. [ABSTRACT FROM AUTHOR]

A novel route to prepare the MgCl 2 –EtOH adduct support was developed. Many factors which effect the morphology of the support were studied in detail. It was found that the stirring speed of dispersion and the molar ratio of EtOH/MgCl 2 had an important influence on the support particle size and particle size distribution. Through varying the stirring speed or changing the EtOH/MgCl 2 ratio, MgCl 2 adduct supports with different particle size and particle size distribution could be obtained. [ABSTRACT FROM AUTHOR]

Utilizing the Diels-Alder reaction between cyclopentadiene groups attached on the linear polystyrene in the presence of nitroxide free radicals, a novel cross-linked network containing nitroxide free radicals is prepared. The signals of the electron spin resonance (ESR) from the resultant paramagnetic polymeric material contacting with organic molecules are different from uncontacting with organic molecules obviously. And the response from the organic molecules to organic molecules free or vice versa was reversible. Therefore, the resultant material is a novel paramagnetic polymeric sensor material sensitive to organic molecules and can be used for detecting the presence of organic molecules or the absence of organic molecules. [ABSTRACT FROM AUTHOR]

Five iodine boracites, M3B7O13I (M = Mn, Fe, Co, Ni, Cd), have been synthesized by reactions of metal oxide, B2O3, element B, and I2 at intermediate temperature above 350 °C. Powder X-ray diffraction analyses verify the identities and purity of the products, which are also confirmed by magnetic property measurement Except safe, cheap, and convenient, this novel method is significandy flexible in the selection of the starting metal oxide. The influence of the reaction temperature and time has also been studied. [ABSTRACT FROM AUTHOR]

Interaction of NH3BH3and Li2NH (or Li3N) in THF leads to the formation of NH3and LiNH2BH3, which further react with each other and produce ca.10 wt.% hydrogen at 45 °C. [ABSTRACT FROM AUTHOR]

Ferric molybdate nanotubes prepared based on the Kirkendall effect and solid-state reaction exhibit a unique catalytic property for epoxidation of propene by molecular oxygen. [ABSTRACT FROM AUTHOR]

Imidazolinium-derived carbenes catalyze the ring-expansion lactonization of oxacycloalkane-2-carboxaldehydes. A variety of functionalized five-, six-, and seven-membered lactones can be formed efficiently under mild reaction conditions. The success of this new method for the construction of lactones is highly influenced by the electronic nature of the carbene catalyst. [ABSTRACT FROM AUTHOR]

Novel nickel complexes bearing P,N,P-, P,N,N- and N,N,N- amido pincer ligands exhibited highly catalytic activity in Kumada coupling reactions. [ABSTRACT FROM AUTHOR]

The title dinuclear complex, [Cu2Cl2(C16H13N2P)2], possesses a crystallographically imposed inversion center. Two Cu atoms are connected by two bridging phenyl­bis(2-pyrid­yl)phosphine ligands. Each Cu atom adopts a distorted tetra­hedral geometry, coordinated by one Cl atom [Cu—Cl = 2.3107 (6) Å], two N atoms [Cu—N = 2.065 (2) and 2.066 (2) Å] from one phenyl­bis(2-pyrid­yl)phosphine ligand and one P atom [Cu—P = 2.1757 (7) Å] from another ligand. [ABSTRACT FROM AUTHOR]

The acid-base properties of several new calix[4]arene derivatives were studied with chemometric methods by measurement of their UV absorbances under different pH. Resolving the acidbase fraction curves with chemometric methods, the pK[suba] of these derivatives were determined and the fraction curves and pure absorbing spectra of each absorbing component in the calixarene system were obtained. The proton dissociation behavior of these derivatives was also discussed in this paper. [ABSTRACT FROM AUTHOR]

A Cu(II)-mediated ortho-C-H hydroxylation using a removable directing group has been developed. The reaction exhibits considerable functional group tolerance. The use of O2 as an oxidant is crucial for the reactivity. Water is also found to significantly improve this reaction. [ABSTRACT FROM AUTHOR]

Poly (l-lactic acid) (PLLA) is a biobased polymer, and poly(trimethylene terephthalate) (PTT) is a semibiobased polymer. However, PLLA is biodegradable, and PTT is not. In this paper, their copolymers (PTHT−PLLA) are synthesized via chain-extension reaction of hydroxyl terminated poly(trimethylene-co-hexamethylene terephthalate) (PTHT−OH) and hydroxyl terminated poly(l-lactic acid) (PLLA−OH) using toluene-2,4-diisocyanate (TDI) as a chain extender. The structures and molecular weights of PTHT−OH, PLLA−OH, and PTHT−PLLA were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The thermal, crystalline, and mechanical properties of PTHT−PLLA were further studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and tensile testing. The resulting PTHT−PLLA copolyesters went through a two-stage thermal decomposition behavior and showed two glass transition temperatures. The tensile testing results showed that PTHT−PLLA copolyesters have excellent flexibility with a strain of more than 300%, which is much higher than that of PLLA. The copolyesters are expected to have a better biodegradability than PTT. [ABSTRACT FROM AUTHOR]

Up to now, little effort has been made to exploit large-area high-throughput patterning by block copolymer (BCP) lithography to generate nanostructured substrates with periods well below 100 nm for surface-enhanced Raman scattering (SERS). We show that simple BCP-templated galvanic displacement reactions yield dense arrays of mushroom-shaped gold nanopillars with a period of 50 nm. The nanoporous BCP films used as templates were obtained by swelling-induced reconstruction of reverse micelle monolayers deposited on silicon wafers. Coupling of adjacent mushroom caps almost impinging on each other combined with their strong local curvature results in a high spatial density of hot spots in the narrow gaps between them. Thus, substrates characterized by high SERS efficiencies are obtained. [ABSTRACT FROM AUTHOR]

The pyrolysis of benzyl alcohol (A1CH 2 OH) at 30 and 760 torr was studied in a flow tube reactor. The synchrotron radiation photoionization and molecular-beam mass spectrometry (MBMS) techniques were used to identify and quantify 35 intermediates and products including some small species, several monophenyl ring species, and a large number of polyaromatic hydrocarbons (PAHs). A comprehensive chemical kinetic reaction model involving 376 species and 2171 reactions was developed with reasonable prediction. According to the rate-of-production analysis, the consumption of A1CH 2 OH is mainly proceeded with the H-abstraction reactions with H atoms and OH radicals under both pressures. H-abstractions and unimolecular dissociation dehydrogenation reactions also play important roles in the subsequent formation of PAHs. Phenyl radicals, benzene (A1), and benzyl (A1CH 2) radicals are important intermediates in the pyrolysis of A1CH 2 OH, which provide various ways for the formation of PAHs. Sensitivity analysis presents that the most significant sensitive reaction of A1CH 2 OH consumption is the unimolecular initiation reaction by the C O bond breaking from A1CH 2 OH under both pressures. The combination of A1CH 2 radicals with H atoms to form toluene (A1CH 3) has the most inhibiting influence on the A1CH 2 OH consumption under both pressures, while it has little sensitive effects for the oxidation process of A1CH 2 OH consumption. The comparison of the A1CH 2 OH pyrolysis and oxidation results show that the peak mole fractions of A1 increase, while the peak mole fractions of phenol (A1OH) decrease with the increase of equivalence ratio (φ) under the same pressure. It should be noted that the peak mole fractions of benzaldehyde (A1CHO) are relatively stable with various conditions. These results provide a theoretical basis for further study of the combustion chemical kinetics of A1CH 2 OH and its application in bio alternative fuel. [ABSTRACT FROM AUTHOR]

Inorganic nanocrystals, such as quantum dots (QDs), hold great promise as molecular imaging contrast agents because of their superior optical properties. However, the molecular imaging sensitivity of these probes is far from optimized due to the lack of efficient and general method for molecular engineering of nanocrystal into effective bioprobes for signal-amplified imaging. Herein, we develop a strategy to boost the molecular imaging sensitivity of QDs over the limit by copolymerizing QDs and cell-binding aptamers into linear QD-aptamer polymers (QAPs) through DNA-programmed hybridization chain reaction. We show that the cancer cells treated with QAPs exhibit much stronger photoluminescence (PL) signal than those treated with QD-aptamer monomers (QAMs) because of multivalent binding and multi-QD-based signal amplification. The enhanced cell binding and imaging capacity of QAPs significantly improves imaging-based discrimination between different cancer cell types. This approach adds a new dimension for engineering inorganic nanoparticles into effective bioprobes for biomedical applications. [ABSTRACT FROM AUTHOR]