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BACKGROUND Galangin is believed to exert antioxidant effects by inhibition of the NLR family pyrin domain containing 3 (NLRP3) inflammasome, which has been linked to chemotherapy sensitivity in cancers. In this study, we explored the synergistic effect of galangin in combination with the chemotherapy agent 5-fluorouracil (5-FU) in esophageal cancer cells and xenografts. MATERIAL AND METHODS The esophageal squamous epithelium cell line Het-1A and 2 human esophageal cancer cell lines (Eca109, OE19) were used to investigate the effect of galangin with or without 5-FU in vitro through proliferation and invasion analyses, while apoptosis was analyzed in cancer cells. Furthermore, a subcutaneous xenograft tumor model in mice was used to study cancer development in vivo. RESULTS Compared with 5-FU monotherapy, combined galangin and 5-FU treatment reduced human esophageal cancer cell growth activities and invasion abilities. The results suggested that galangin had a chemotherapy-sensitized synergistic antitumor effect induced by 5-FU. The susceptibility of cancer cells to apoptosis, which is linked with chemotherapy sensitivity, was induced by 5-FU and further enhanced by galangin. NLRP3 was identified as being significantly activated by 5-FU, but galangin treatment reversed the effect and inhibited NLRP3 expression, which was accompanied by downregulated interleukin-1b levels. Further investigation showed that the induced apoptotic cascade can be mostly reversed by incubation with an NLRP3 activator, irrespective of AKT signaling. Using xenograft mouse models, we found that galangin exposure further restrained cancer development after 5-FU treatment and increased sensitivity to chemotherapy by suppressing the NLRP3 inflammasome pathway. CONCLUSIONS Our results indicated that galangin played a synergistic anticancer role through NLRP3 inflammasome inhibition when paired with FU-5.

For the first time, a novel strategy is developed to couple photocatalytic oxidation with photocatalytic reduction to achieve one-pot conversion of rhodamine (RhB) to methanol and ethanol by using rGO/SrTi0.95Fe0.05O3−δ photocatalyst. In the approach, RhB was photocatalytically degraded to CO2 and water, and then the as-obtained CO2 was converted into CH3OH and C2H5OH by means of photocatalytic reduction under simulated sunlight irradiation. Photocatalytic experimental results show the 1%rGO/SrTi0.95Fe0.05O3−δ has the best photocatalytic activity among the as-prepared catalysts and the corresponding product rate of CH3OH and C2H5OH is 10.76 and 6.14 μmol g−1 h−1, respectively, with a 1.53% apparent quantum efficiency. Furthermore, a photocatalytic mechanism was proposed to explain the detailed process of one-pot conversion of RhB into hydrocarbons. The present work gives a good example to combine the photodegradation of RhB with photoreduction of CO2 and proposes a new method to simultaneously tackle the problems of environmental pollution and energy crisis.

The molecule 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoic acid (danshensu), a herbal preparation used in traditional Chinese medicine, has been found to possess potential antitumor and anti-angiogenesis effects. The aim of the present study was to investigate the efficacy of the combination of radiation therapy (RT) with danshensu in the treatment of Lewis lung carcinoma (LLC) xenografts, whilst exploring and evaluating the mechanism involved. In total, 8-week old female C57BL/6J mice were randomly assigned into 3 groups to receive: RT, RT + cisplatin and RT + danshensu, respectively, when LLC reached 100-150 mm3. Each group was divided into 7 subgroups according to the different irradiation doses that were administered. Tumor growth curves were created and the sensitization enhancement ratios of the drugs were calculated. The experiment was then repeated, and the 4 groups of tumor-bearing mice were treated with natural saline, danshensu, RT + danshensu and RT, respectively. The mice were sacrificed on day 7, and tumor tissue and blood were collected to determine microvessel density, the expression of proangiogenic factors, and the levels of blood thromboxane B2 and 6-keto-prostaglandin-F1α. Tumor hypoxia was also detected using in vivo fluorescence imaging. With respect to LLC xenografts, treatment with danshensu + RT significantly enhanced the effects of tumor growth inhibition (P

Ischemia-induced brain damage leads to apoptosis like delayed neuronal death in selectively vulnerable regions, which could further result in irreversible damages. Previous studies have demonstrated that neurons in the CA1 area of hippocampus are particularly sensitive to ischemic damage. Atorvastatin (ATV) has been reported to attenuate cognitive deficits after stroke, but precise mechanism for neuroprotection remains unknown. Therefore, the aims of this study were to investigate the neuroprotective mechanisms of ATV against ischemic brain injury induced by cerebral ischemia reperfusion. In this study, four-vessel occlusion model was established in rats with cerebral ischemia. Rats were divided into five groups: sham group, I/R group, I/R+ATV group, I/R+ATV+LY, and I/R+SP600125 group. Cresyl violet staining was carried out to examine the neuronal death of hippocampal CA1 region. Immunoblotting was used to detect the expression of the related proteins. Results showed that ATV significantly protected hippocampal CA1 pyramidal neurons against cerebral I/R. ATV could increase the phosphorylation of protein kinase B (Akt1) and nNOS, diminished the phosphorylation of JNK3 and c-Jun, and further inhibited the activation of caspase-3. Whereas, all of the aforementioned effects of ATV were reversed by LY294002 (an inhibitor of Akt1). Furthermore, pretreatment with SP600125 (an inhibitor of JNK) diminished the phosphorylation of JNK3 and c-Jun, and further inhibited the activation of caspase-3 after cerebral I/R. Taken together, our results implied that Akt-mediated phosphorylation of nNOS is involved in the neuroprotection of ATV against ischemic brain injury via suppressing JNK3 signaling pathway that provide a new experimental foundation for stroke therapy.

In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-β-d-mannopyranosyl and (1→4)-linked-β-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.

In this study, N, N’-carbonic bis(piperonylic acid) dihydrazide (BPACH) was synthesized to broaden the category of piperonylic acid derivative and evaluate its influences on the thermal properties of poly(L-lactic acid) (PLLA). The geometry optimization of BPACH showed that the highest occupied molecular orbital mainly focused on the formed amide group and carbonic dihydrazide, whereas the lowest unoccupied molecular orbital mainly focused on the piperonylic acid, and the orbital energy gap was 0.10418 eV. The differences in melt-crystallization processes of the neat PLLA and PLLA/BPACH samples indicated that the BPACH could provide the effective nucleation site to accelerate the crystallization of PLLA, but the crystallization accelerating effect was still further improved compared to some reported nucleating agents. The melting behaviors of PLLA/BPACH samples after crystallization depended on the crystallization temperatures and heating rates; additionally, the melting processes could also effectively reflect the previous crystallization behaviors.

A series of heterostructured CdS/Sr2(Nb17/18Zn1/18)2O7-δ composites with excellent photocatalytic ability for simultaneous hydrogen evolution and As(III) oxidation under simulated sunlight were synthesized and characterized. Among them, 30% CdS/Sr2(Nb17/18Zn1/18)2O7-δ (30CSNZO) has the highest in activity, exhibiting a H2 production rate of 1669.1 μmol·h(-1)·g(-1) that is higher than that of many photocatalysts recently reported in the literature. At pH 9, As(III) is completely oxidized to As(V) over 30CSNZO in 30 min of irradiation of simulated sunlight. In the photocatalytic system, H2 production rate decreases with the increase of As(III) concentration, and the recycle experiments show that 30CSNZO exhibits excellent stability, durability, and recyclability for photocatalytic hydrogen evolution and As(III) oxidation. We propose a mechanism in which superoxide radical (·O2(-)) is the active species for As(III) oxidation and the oxidation of As(III) has an effect on hydrogen evolution. For the first time, it is demonstrated that simultaneous hydrogen evolution and arsenite oxidation is possible in a photocatalytic system.

We report the new roles of graphene oxide (GO) as structure-directing and morphology-controlling agents in the nucleation and growth of heterostructured Bi2MoO6/Bi3.64Mo0.36O6.55 composites. The heterostructured composites have been fabricated through a facile one-step hydrothermal method, among which the interfacial contact between Bi2MoO6/Bi3.64Mo0.36O6.55 and graphene is achieved. The as-prepared composites were characterized by powder X-ray diffraction, UV–vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The composition, morphology and structure of the composites can be controlled by regulating the amount of GO used in the synthesis. We proposed a plausible mechanism for their formation, and evaluated them for the photocatalytic degradation of Rhodamine B (RhB). Among them, the 1% graphene-Bi2MoO6/Bi3.64Mo0.36O6.55 (1%G-BMO) composite performs the best. The efficacy of 1%G-BMO is attributed to the optimal Bi2MoO6/Bi3.64Mo0.36O6.55 phase ratio, the unique morphology and structure, as well as the effective separation of photogenerated electrons and holes.

Graphene oxide (GO) was found to be a metal-free, water-tolerant and high-efficiency catalyst towards the cycloaddition of carbon dioxide (CO2) to propylene oxide (PO) for the synthesis of propylene carbonate (PC) at room temperature (RT) and atmospheric pressure without the need for a solvent. Using GO as catalyst and tetrabutylammonium bromide (Bu4NBr) as co-catalyst, PO is rapidly converted to PC with 96% yield and 100% selectivity under relatively mild conditions (100 °C, 2.25 MPa, 1 h). The effects of catalyst amount, temperature, time and water (H2O) addition on the reaction were investigated. It is found that the presence of a proper amount of H2O enhances the conversion of epoxide remarkably. A comparison of the catalytic activities of a number of reduced graphene oxide (r-GO) samples under similar reaction conditions revealed that it is the hydroxyl groups (rather than the carboxyl groups) on GO that form hydrogen bonds with PO, and act synergistically with halide anions to promote the cycloaddition reaction. A possible mechanism is proposed.

a b s t r a c t CdS/Ba1−xZnxTiO3 heterostructured photocatalysts were developed as a highly efficient and stable system for photocatalytic evolution of hydrogen from water splitting. In the system, CdS not only functions as photosensitizer to absorb visible light, but also participates with Ba1−xZnxTiO3 for the generation of heterojunctions that block the recombination of photogenerated electrons and holes. The photocatalysts show excellent activity and stability, giving a high H2 production rate of 1473 mol h−1 g−1 under the irradiation of simulated solar light in a test period of 480 h without loading any noble metal as cocatalyst or any reagents for regeneration. This study demonstrates that the development of CdS nanoparticles as photosensitizer is feasible for the photocatalytic H2 production.

A series of cross-linked polydivinylbenzene polymers covalently grafted with various (hydroxyl, carboxyl, and amino) functional ionic liquid were fabricated by a simple method and evaluated as heterogeneous catalysts for the synthesis of cyclic carbonates from CO2 and epoxides. The as-fabricated catalysts show good performance across a wide range of epoxides in the absence of solvent and co-catalyst, especially the one that was grafted with hydroxyl ionic liquid. The effects of functional groups in ionic liquid, reaction temperature, initial CO2 pressure, and reaction time on the cycloaddition reaction were investigated. It is suggested that synergetic effect between functional groups and bromide ions facilitates the catalytic reaction. It is noted that the hydroxyl group with moderate hydrogen bonding is more crucial for the cycloaddition reaction than the other groups. In addition, the recycling test showed that the catalyst could be reused for as many as six times without any loss of catalytic activity.

In this paper,The software design of oleifera camellia seed hyperspectral detection system is completed based on visual Basic6.0, which firstly reads hyperspectral file ( the TXT file after ViewspecPro professional software ), and selects the effective hyperspectral data. Then it needs to make the pretreatment and extraction of sensitive bands for hyperspectral data, and finish the content detection of oleifera camellia seed fatty acid oleic acid, linoleic acid, and palmitic with sensitive bands hyperspectral data and the Hyperspectral model. Finally, it needs to store the results are analyzed. It realizes the method that simple, real-time and fast detection on the content of fat acid composition of oleifera camellia seed.

Novel ternary heterostructured TiO 2 –Bi 2 MoO 6 /Bi 3.64 Mo 0.36 O 6.55 were synthesized by a one-pot template-free solvothermal method. For comparison studies, Bi 2 MoO 6 , Bi 3.64 Mo 0.36 O 6.55 , Bi 2 MoO 6 /Bi 3.64 Mo 0.36 O 6.55 , TiO 2 –Bi 2 MoO 6 , and TiO 2 –Bi 3.64 Mo 0.36 O 6.55 were also synthesized likewise. The photocatalysts were characterized by powder X-ray diffraction, UV–vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The experimental results showed that the composition, morphology and structure of the photocatalysts can be well controlled by adjusting the pH value, alcohol/water ratio, and TiO 2 content. Based on the findings, we put forward a mechanism for the formation of the materials. Furthermore, the results of photocatalytic degradation of Rhodamine B (RhB) and o-nitrophenol over the as-prepared materials indicate that photocatalytic efficiency can be closely related to the composition, morphology and structure of the materials. The ternary heterostructured 5%TiO 2 –Bi 2 MoO 6 /Bi 3.64 Mo 0.36 O 6.55 exhibits good visible-light driven photocatalytic activity in the degradation of RhB and o-nitrophenol, much higher than those of TiO 2 , Bi 2 MoO 6 , Bi 3.64 Mo 0.36 O 6.55 , and any combination of the three. Finally, a new mechanism for the photocatalytic action of the heterostructured materials was put forward. Overall, the investigation provides a new reaction mode to explain the effective interfacial charge transfer and the significant improvement in photocatalytic efficiency of the ternary heterostructured composites.

The removal of Cu2+ ions from aqueous solution was studied using pickled diatomite samples. The linear Langmuir and Freundlich adsorption equations were applied to describe the equilibrium isotherms. The pseudo-first-order and pseudo-second-order models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model.

Magnetic Fe3O4/SiO2/Bi2WO6 microspheres with photocatalytic properties have been synthesized using a silica layer for “bonding” (adhering Bi2WO6 to Fe3O4). The morphology, composition and magnetic properties of the Fe3O4/SiO2/Bi2WO6 composites were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and BET surface area analysis. The activity of the material in photocatalytic decoloration of aqueous rhodamine B (RhB) solution under visible light was evaluated. The results showed that Bi2WO6 combined well with the magnetic Fe3O4/SiO2 nanoparticles. The Fe3O4/SiO2/Bi2WO6 composites were spherical in shape, having a mean size of 2 μm. The spent catalyst could be recycled with only slight decline in catalytic activity. It is envisaged that the stability, reusability, and magnetic nature of the Fe3O4/SiO2/Bi2WO6 catalyst warrants its application in photocatalysis.

Polystyrene grafted with quaternary ammonium salts were obtained by direct quaternarization of chloromethylated polystyrene with N,N-dimethylethylamine, N,N-dimethylglycine (denoted as PS-QNS and PS-CQNS, respectively). These two polymer-supported ionic liquids were found to show high catalytic efficiency towards the cycloaddition of CO2 to epoxides. The effects of catalyst amount, reaction temperature, initial CO2 pressure, and reaction time on the yield of cyclic carbonates were investigated systematically. Under the optimal reaction conditions (150 °C, initial CO2 pressure 2.0 MPa and 5 h), propylene carbonate yield and selectivity in the cycloaddition of CO2 to propylene oxide over PS-CQNS were 96.2 and 99.3 % whereas those over PS-QNS were 97.9 and 99.5 %, respectively. It was observed that the reusability of PS-QNS was excellent. From the viewpoint of industrial application, PS-QNS is attractive in terms of catalytic efficiency, cost and simplicity in preparation. Polystyrene bearing quaternary ammonium salt ionic liquids (denoted as PS-QNS and PS-CQNS) were fabricated and evaluated for solventless synthesis of cyclic carbonates from CO2 and epoxides. The catalysts are low in cost and simple to prepare, and show good activity, selectivity, stability and reusability towards the cycloaddition reaction.

A facile, fast and low-cost method was developed for the synthesis of novel flower-like Bi2O2CO3 in an aqueous medium with the assistance of cetyltrimethylammonium bromide (CTAB). The as-synthesized flower-like Bi2O2CO3 was characterized using the powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, UV–vis diffuse reflectance spectra, and N2 adsorption–desorption techniques. It was found that the nanomaterial exhibited high photocatalytic efficiency towards the degradation of wastewater dyes (rhodamine-B, methylene orange, crystal violet or their mixture) under UV–vis light irradiation. There was only a slight decrease in photocatalytic activity after 5-time recycling (with above 99% removal), suggesting that the catalyst is highly stable and reusable. The relationship between structure and catalytic performance of the flower-like Bi2O2CO3 was investigated. It is deduced that the high photocatalytic activity can be attributed to the flower-like morphology, thin nanopetals, low band gap, and large specific surface area.

Novel nanostructured flower-like bismuth oxychloride (BiOCl) has been fast synthesized by a simple method in the presence of nitric acid and l -Lysine. The BiOCl nano-flowers, with a narrow band gap (2.87 eV), show excellent photocatalytic activity in the degradation of Rh–B dye under visible light (λ ≥ 435 nm), much higher than those of the photocatalysts ever reported in the literatures.

Bi2O2CO3/BiOI composites were fabricated at room temperature for the first time by a facile method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (UV–vis DRS), and nitrogen adsorption–desorption techniques were employed to characterize the physiochemical properties of the composites. The photocatalytic activities of Bi2O2CO3, BiOI, and Bi2O2CO3/BiOI were evaluated through the photocleaning of wastewater which contained rhodamine-B, methylene blue, crystal violet, or a mixture of them under visible-light irradiation (λ ≥ 420 nm). The photocatalytic activity of Bi2O2CO3/BiOI is much higher than that of its components. Moreover, the composite shows good photostability and recyclability. The excellent catalytic efficiency of the Bi2O2CO3/BiOI composite is deduced closely related to Bi2O2CO3/BiOI heterojunctions whose presence is generally regarded to be a favorable factor for the s...

We report for the first time the hydrothermal synthesis of MgO–SnO2 solid superbase using P123 as template. The basicity of the materials was determined by two approaches of Hammett indicators method and temperature-programmed desorption using CO2 as adsorbate (CO2-TPD). It was found that Mg/Sn molar ratio has an effect on MgO–SnO2 basicity, and superbasicity was observed only at Mg/Sn molar ratio of 1. With variation of Mg/Sn molar ratio, superbase strength (H -) was in the 26.5–33.0 range, showing superbasic value up to 0.939 mmol/g. The structure and texture of the as-prepared materials were studied by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 physio-adsorption methods. We detected particles of spherical morphology having diameter of ca. 150 nm. N2 adsorption–desorption results suggested that the materials are of mesoporous structure, having specific surface area of 115.2 m2/g and average pore diameter of 6 nm. The superbase was found to exhibit excellent catalytic activity towards the one-pot synthesis of polyfunctionalized 4H-pyrans through the condensation of aldehydes, malononitrile, and an active methylene compound. Its excellent catalytic efficiency is related to its superbasicity of the MgO–SnO2. The results provide a new route for the design and preparation of composite oxide superbases. Furthermore, the solid superbases will facilitate a strategy for high-efficiency synthesis of polyfunctionalized 4H-pyrans. Novel MgO–SnO2 solid superbase was prepared using P123 as template. Its superbase strength was in the 26.5–33.0 range, showing superbasic sites up to 0.939 mmol/g. The material is of mesoporous structure,(having specific surface area of 115.2 m2/g and average pore diameter of 6 nm. It was found to exhibit excellent catalytic activity towards the one-pot solvent-free synthesis of polyfunctionalized 4H-pyrans through the condensation of aldehydes, malononitrile, and an active methylene compound. The results provide a new route for the design and preparation of composite oxide superbases.

It has been shown that sodium stannate with superbasic sites generated on its surface can be obtained through simple thermal treatment of sodium stannate hydrate in pure N 2 . In this study, we analyzed the as-prepared materials using powder X-ray diffraction, X-ray photoelectron spectroscopy, and N 2 physisorption methods. The superbasic sites were characterized by techniques of Hammett indicators and temperature-programmed desorption using CO 2 as adsorbate. It was shown that after undergoing calcination at 623 K, there are ample superbasic sites on sodium stannate: up to 0.254 mmol/g. The superbasicity of the materials was further confirmed by employing the 1-hexene as well as cyclohexa-1,4-diene double bond isomerization reactions. The superbasicity is attributed to the higher electron-donating ability of surface O 2− . The sodium stannate samples showed excellent catalytic efficiency towards selected reactions, namely the dehydrogenation of propa-2-nol, Michael addition of electron-deficient olefins, and transesterification of cyclic carbonate with methanol. It was observed that with rise of heat-treatment temperature from 573 to 623 K, both superbasicity and catalytic activity increased, reaching a maximum at 623 K, and then declined. It is deduced that catalytic efficiency is closely related to superbasicity of the sodium stannate catalysts.

Two heterometal–organic coordination polymers with chelidamic acid ligands, [AgNd(C7H3NO5)2·3H2O]n (1) and 0.75H3O·[K0.25Nd(C7H3NO5)2·3H2O]·1.75H2O (2), have been synthesized and characterized by X-ray single-crystal diffraction. The crystal structure of 1 features that chelating units composed of one Nd(III) ion and two tridentate chelating chelidamic acid ligands are connected by the Ag(I) ions to form a one-dimensional chain, further linked by hydrogen bonds into a 3D network. As for 2, discrete independent molecules, made up of Nd(III) and K(I) ions and chelidamic acid ligands, are linked through the hydrogen bonds to form a 1D chain, which are further inter-linked through the complex hydrogen bonds to form a 3D network. The optical properties of 1 and 2 were investigated in terms of fluorescent spectra, which both exhibit good luminescence.

In this paper three kind of water borne polyurethane are synthesized. FTIR identify the structure of 2-hydroxypropyl acrylate terminated water borne polyurethane with block PDMS. It is found that Si-WPUA has excellent water-resistance, good toughness, and good tensile strength. So, the work has been found the method which could improve water resistance and not decrease mechanical properties. It is hoped that the modified polyurethane could be used as coatings superior to the solvent-borne systems.

A new framework compound, [Hg4As2](InBr3.5As0.5) (1), has been prepared by the solid-state reaction of Hg2Br2 with elemental In and As at 450 °C. Compound 1 crystallizes in the space group P63/mmc of the Hexagonal system with two formula units in a cell: a = b = 7.7408(6) A, c = 12.5350(19) A, V = 650.47(12) A3. The crystal structure of 1 features a novel 3D framework, [Hg4As2]2+ with tridymite topology. The optical properties were investigated in terms of the diffuse reflectance and infrared spectra. The electronic band structure along with density of states (DOS) calculated by DFT method indicates that the present compound is semiconductor, and the optical absorption is mainly originated from the charge transitions from Br-4p and As-4p states to Hg-6s and In-5p states.

The introduction of hydrophilic groups, such as -COOH, -SO3, -OH, -O-, into the polyurethane resin, so that waterborne polyurethane products in the water resistance, solvent resistance, weather and other aspects of performance are worse than solvent borne systems. In our work, to improve the water resistance of the films for waterborne polyurethane, we incorporated C=C bond into the side chain of polyurethane by using pentaerythritol diacrylate as an extension agent. By measuring the cured polyurethane films absorption and mechanical properties, we determine the conditions for UV curing, 3% TMPME, photoinitiator (2959) and to UV light application time for 30s. With the increase of the amount PEDA, water resistance, hardness and tensile strength increase. Furthermore, with the improved water resistance, it is hoped that the performance of waterborne polyurethane can be comparative or superior to the solvent-borne systems.

White light emitting polymers were synthesized through incorporating of low-band gap red light emitting 4,7-di(4-hexyl-thien-2-yl)-2,1,3-benzothiadiazole (DHTBT) moieties into the backbone of a blue-light-emitting poly(9,9-dioctylfluorene) (PFO). Incomplete energy transfer from the blue electroluminescent PFO backbone to the red light emitting unit occurred by carefully controlling the relative content of the low-band gap unit DHTBT in the resulting polymers. Pure white light electroluminescence from a single polymer has been obtained in a device with a configuration of ITO/PVK/polymer/Ba/Al.The highest external quantum efficiency is 1.04% at the luminance of 249 cd/m2 for the white emitting polymer with color coordinates (0.30, 0.35) very close to the CIE coordinates for National Television System Committee (NTSC) standard white-light emission (0.33,0.33).

It is necessary to improve the adhesion of the cured rubber to a substrate as it is used extensively. It is well known that an improvement in adhesion can be realized by incorporating in the composition a sliane or siloxane. Although the composition provides good adhesion to many kinds of substrates, it has been found that the adhesive bond degrades rapidly under wet conditions. To be solved it, rosin eater was incorprated in the silcone ruber in the paper. Increasing the content of rosin ester could induce a relative high adhesion in hot water. Moreover, when the content of modified rosin pentaerythritol ester was above 4.5 phr, the immersion days in hot water before adhesive failure occured were three times than that of non-additive rosin esters.

3-(2-hydroxyl-ethyl)-1-propylimidazolium bromide (HEPIMBr) was immobilized onto SBA-15, Al-SBA-15 mesoporous molecular sieves and SiO2 by chemical grafting method. The materials were characterized and used as catalysts for solvent-free synthesis of cyclic carbonates from CO2 and epoxides under relatively mild conditions. Among them, the HEPIMBr immobilized on SBA-15 performs the best, showing carbonate selectivity and yield of ca. 100% (120 °C, 2.0 MPa, 2 h). The catalyst is thermally stable and shows good reusability. Based on the experimental results, a plausible reaction mechanism has been proposed for the catalytic reaction. 3-(2-hydroxyl-ethyl)-1-propylimidazolium bromide (HEPIMBr) was immobilized on SBA-15 mesoporous molecular sieve by chemical grafting method. It was found the material shows high catalytic efficiency and good stability towards the cyclic carbonates synthesis via. Cycloaddition of CO2 to epoxides. Moreover, the catalyst can be easily separated from the product. A plausible reaction mechanism has been proposed for the catalytic action.

A series of Zn-Al composite oxides that were modified with alkaline earth metals, Zn-M-Al-O (M = Mg, Ca, Sr, and Ba) were fabricated via calcination of the corresponding hydrotalcite precursors, and evaluated as catalysts for the synthesis of propylene carbonate (PC) from CO2 and propylene oxide. Among the Zn-M-Al-O catalysts, Zn-Mg-Al-O (Zn/Mg = 4.0, pH = 10, without hydrothermal treatment) is the best in performance, showing PC selectivity of 99.2% and yield of 88.8% (140 °C, 12 h). Furthermore, the Zn-Mg-Al-O catalyst can be readily reused and recycled without any loss of activity in a test of five cycles. Through detailed studies of the basic nature of the Zn-M-Al-O catalysts, it was found that a moderate basicity (6.1 ≤ H 0

Calcium phosphate film was prepared by electrochemical deposition technology. Subsequently, the alkaline treatment process of calcium phosphate film in 0.1 mol/L NaOH solution was monitored on real time by the piezoelectric quartz crystal impedance (PQCI) technique. The variations of morphology and composition for the alkaline treatment products were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), respectively. The dynamic variations of calcium phosphate can be characterized by the change of equivalent circuit parameters. The results show that the forming process of hydroxyapatite (HA) is composed of three stages: (1) acidic calcium phosphate dissolution; (2) phase transformation; and (3) HA formation. Furthermore, the correlative kinetic equations and parameters are obtained by fitting the static capacitance (Cs)—time curves.

Six compounds of cyclic hypervalent organobismuth(III) chlorides and triphenylgermylpropionates bearing a nitrogen or sulfur atom as intramolecular coordination atom have been synthesized and characterized. The results of single-crystal X-ray analysis reveal that the eight-membered tetrahydroazabismocine rings are highly flexible. The Bi–S or Bi–N bond lengths in the thiabismocine or azabismocine derivatives are dependent on how the substituted groups are acting on the Bi, S or N atom. The replacement of the chlorine atom in azabismocine and thiabismocine with the triphenylgermylpropionic group (Ph3GeCH2CH2COO ) leads to the lengthening of Bi–N and Bi–S bond. The substituents connected with the nitrogen atom also have an effect on the Bi–N bond length of azabismocine. For example, a cyclohexyl group has electron-donating ability higher than a phenyl group; the replacement of the former by the latter would lead to the decline of Bi–N bond length and increase of CAr–Bi–CAr angle in the eight-membered ring. The in vitro antiproliferative activities of the fabricated materials were compared on gastric carcinoma cells by means of the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) method. It was found that the compounds show antiproliferative activity on gastric carcinoma cells (MGC-803) much higher than that of cisplatin. Moreover, there is enhancement of antiproliferative activity when the chlorine atom of the bismocine compounds is replaced by the triphenylgermylpropionic group, giving a low IC50 value of 0.7 μM for thiabismocine triphenylgermylpropionate.

In this work, PDMS modified PU was synthesized using two-stage method to improve water resistance and weather resistance in the waterborne polyurethane was investigated. It was found that the absorbed water content decreased with increasing PDMS content in polyurethane. It was also found that PDMS modified polyurethane had better solvent resistance than unmodified polyurethane. The structure incorporated the PDMS into the soft segment of polyurethane chains was confirmed by FTIR. The phase separation increased by increasing PDMS content and was confirmed by DSC. The particle size of the dispersions increased and tensile strength and hardness decreased with the increase of PDMS content. Furthermore, with the improved water resistance and elongation, it was hoped that the modified polyurethane could be used as wood coatings superior to the solvent-borne systems.

Sodium overabundance in yellow supergiants has stumped people for more than 20 years. The purpose of this paper is to explore this problem from the perspective of nuclear physics. We investigate carefully the CNO and NeNa cycles that are responsible for sodium production. We investigate some key reactions in the appropriate network. We show whether and how the sodium output can be affected by the rate uncertainties in these reactions. In this way, we evaluate if a reaction is important enough to deserve a better determination of its rate in terrestrial laboratories.

Platinum(Pt)/nanofibrous polyaniline(PANI) electrode was prepared by pulse galvanostatic method and characterized by scanning electron microscopy. The electrochemical behavior of L-cysteine at the Pt/nanofibrous PANI electrode was investigated by cyclic voltammetry. The results indicate that the pH value of the solution and the Pt loading of the electrode have great effect on the electrocatalytic property of the Pt /nanofibrous PANI electrode; the suitable Pt loading of the electrode is 600 μg/cm2 and the suitable pH value of the solution is 4.5 for investigating L-cysteine oxidation. The L-cysteine sensor based on the Pt/nanofibrous PANI electrode has a good selectivity, reproducibility and stability. The Pt/nanofibrous PANI electrode is highly sensitive to L-cysteine, and the linear calibration curve for the oxidation of L-cysteine can be observed in the range of 0.2–5.0 mmol/L.

A retrospective exposure assessment was performed for use in a health outcomes study of a facility manufacturing circuit boards, business machines, and other equipment during the years 1969–2002. A matrix was developed identifying chemical use by department-year based on company-provided information. Use of six chemical agents (fiberglass, lead, methylene chloride, methyl chloroform, perchloroethylene, and trichloroethylene) and six chemical classes (acid-base, aromatic hydrocarbons, chlorinated hydrocarbons, other hydrocarbons, chlorofluorocarbons, and metals), and general (including unspecified) chemicals was identified. The matrix also contained an assignment for each department-year categorizing the potential for use of chemicals as negligible, intermittent/incidental, or routine. These department-based exposure matrix data were combined with work history data to provide duration of potential chemical use for workers. Negligible, intermittent/incidental or routine extent-of-chemical-use categories comprised 42.6%, 39.4%, and 17.9%, respectively, of total person-years of employment. Cumulative exposure scores were also developed, representing a relative measure of the cumulative extent of potential exposure to the six chemical agents, six chemical classes, and general (including unspecified) chemicals. Additionally, the study period was divided into manufacturing eras showing trends in chemical use, and showing that process use of trichloroethylene and methylene chloride ended in the mid-1980s and the mid-1990s, respectively. This approach may be useful in other assessments addressing a variety of chemicals, and with data constraints common to retrospective chemical exposure studies.

A simple method for facile synthesis of three-dimensional (3D) bismuth oxyhalide (BiOX, X═Cl, Br, I) hierarchical structures at room temperature has been developed. Under the influence of L-lysine surfactant, the bismuth and halogen (Cl, Br, I) sources hydrolyze and self-assemble into flower-like hierarchical architectures within 10 min. The resulted materials were characterized by XRD, FESEM, TEM, UV-vis DRS, and N2 adsorption-desorption techniques. We found that l-lysine is indispensable for their formation and the amount of HX has great effect on the final morphology. The BiOX (X═Cl, Br, I) hierarchical architectures are composed of single-crystalline nanoplates. We propose an amino-and-carboxyl structure-directing mechanism for the formation of the hierarchical structures. To evaluate the photocatalytic activity of the as-prepared materials, rhodamine-B was employed as a probe dye for degradation under visible light. All of the BiOX (X═Cl, Br, I) with 3D architectures show higher photocatalytic activities than their sheet-like counterparts. The superior activity is ascribed to the better light-harvesting capacity of the 3D hierarchical structures. The adopted method can be applied for large-scale generation of novel structures of similar kinds in a facile manner.

The planar and nonplanar conformers of metal derivatives of 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP) and 5-nitro-2,3,7,8,12,13,17,18-octaethylporphyrin (NO[sub 2]-OEP) are investigated using resonance Raman spectroscopy. The structural heterogeneity is assessed by analysis of the line shapes of the structure-sensitive Raman lines. First, heterogeneity in the conformation of the macrocycle has been detected in solutions of the nickel and cobalt derivatives of OEP, that is, both planar and nonplanar conformers are found to coexist at room temperature for these metal porphyrins but not for the Cu and Zn derivatives. The latter metals expand the porphyrin core, shifting the equilibrium entirely to the planar conformer. Second, we find that substitution with a single NO[sub 2] group at one of the methine-bridge carbons shifts this planar-nonplanar equilibrium substantially toward the nonplanar conformer. Thus, both crowding of the peripheral substituents and contracting of the porphyrin core (Ni(II) < Co(II) < Cu(II) < Zn(II)) displace the equilibrium toward the nonplanar conformer. Finally, the frequencies of several Raman lines correlate with structural parameters such as core size (obtained either from molecular mechanics calculations or from X-ray crystallographic studies). 30 refs., 6 figs., 3 tabs.

Single crystals of the title compound are prepared by solid state reaction of Hg2Br2, elemental In, and As (400 °C, 120 h).

1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br((-))] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br((-)) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers.

1-Bromopropane (1-BP) is an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, and cleaning solvents. There is concern that 1-BP may be a reproductive and neurological toxicant. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. The main objectives were to evaluate urinary bromide [Br(−)] and N-acetyl-S-(n-propyl)-l-cysteine (AcPrCys) for assessing 1-BP exposure in workers with low exposure. Workers’ 1-BP exposures were measured in their breathing zones with gas chromatography-flame ionization detection via NIOSH 1025. Urine specimens were obtained over a 48-h period at five facilities using vapor degreasers and one adhesive manufacturer. All of the workers’ urine was collected into composite samples and analyzed separately representing daily time intervals: at work, after work but before bedtime, and upon awakening. Urinary metabolites were analyzed using intra-coupled plasma-mass spectroscopy for Br(−), and high-performance liquid chromatography and electro-spray ionization mass spectroscopy for AcPrCys. Time-weighted average (TWA) geometric mean (GM) breathing zone concentrations of 1-BP at vapor degreasing facilities were 2.6 and 0.31 ppm, respectively, for workers near degreasers and those remote from degreasers. Urine metabolites showed the same trend as TWA exposures: higher levels were observed for workers near degreasers (48-h GM Br(−) = 8.9 vs. 3.7; 48-h GM AcPrCys = 1.3 vs. 0.12, respectively). Associations of Br(−) and AcPrCys concentrations with 1-BP TWA were statistically significant near degreasers (p

Large-scale synthesis of semiconductor nanocrystals or quantum dots (QDs) with high concentration and high yield through simultaneously increasing the precursor concentration was introduced. This synthetic route conducted in diesel has produced gram-scale CdSe semiconductor quantum dots (In optimal scale-up synthetic condition, the one-pot yield of QDs is up to 9.6g). The reaction has been conducted in open air and at relatively low temperature at 190-230 degrees C in the absence of expensive organic phosphine ligands, aliphatic amine and octadecene, which is really green chemistry without high energy cost for high temperature reaction and unessential toxic chemicals except for Cd, which is the essential building block for QDs.

The role of the oxyanion hole in the reaction catalyzed by pig medium-chain acyl-CoA dehydrogenase (pMCAD) has been investigated using enzyme reconstituted with 2'-deoxy-FAD. The k(cat) (18.8 +/- 0.5 s(-1)) and K(m) (2.5 +/- 0.4 microM) values for the oxidation of n-octanoyl-CoA (C(8)-CoA) by WT pMCAD recombinantly expressed in Escherichia coli are similar to those of native pMCAD isolated from pig kidney. In agreement with previous studies [Engst et al. (1999) Biochemistry 38, 257-267], reconstitution of the WT enzyme with 2'-deoxy-FAD causes a large (400-fold) decrease in k(cat) but has little effect on K(m). To investigate the molecular basis for the alterations in activity resulting from changes in hydrogen bonding between the substrate and the enzyme's oxyanion hole, the structure of the product analogue hexadienoyl-CoA (HD-CoA) bound to the 2'-deoxy-FAD-reconstituted enzyme has been probed by Raman spectroscopy. Importantly, while WT pMCAD causes a 27 cm(-1) decrease in the vibrational frequency of the HD enone band, from 1595 to 1568 cm(-1), the enone band is only shifted 10 cm(-1) upon binding HD-CoA to 2'-deoxy-FAD pMCAD. Thus, removal of the 2'-ribityl hydroxyl group results in a substantial reduction in the ability of the enzyme to polarize the ground state of the ES complex. On the basis of an analysis of a similar system, it is estimated that ground state destabilization is reduced by up to 17 kJ mol(-1), while the activation energy for the reaction is raised 15 kJ mol(-1). In addition, removal of the 2'-ribityl hydroxyl reduces the redox potential shift that is induced by HD-CoA binding from 18 to 11 kJ mol(-1). Consequently, while ligand polarization caused by hydrogen bonding in the oxyanion hole is intimately linked to substrate turnover, additional factors must be responsible for ligand-induced changes in redox potential. Finally, while replacement of the catalytic base E376 with Gln abolishes the ability of the enzyme to catalyze substrate oxidation and to catalyze the exchange of the C(8)-CoA alpha-protons with solvent deuterium, the 2'-deoxy-FAD-reconstituted enzyme catalyzes alpha-proton exchange at a rate (k(exc)) of 0.085 s(-1), which is only 4-fold slower than k(exc) for WT pMCAD (0.35 s(-1)). Thus, either the oxyanion hole plays only a minor role in stabilizing the transition state for alpha-proton exchange, in contrast to its role in substrate oxidation, or the value of k(exc) for WT pMCAD reflects a process such as exchange of the E376 COOH proton with solvent.

By adjusting the amount of AgNO3, hollow and porous silver bismuth vanadate (Ag/BiVO4) composites were synthesized by a one-step method using ethylene glycol and water as solvents, and L-lysine as a surfactant. The as-synthesized samples were characterized by XRD, XPS, SEM, TEM (HRTEM), UV-vis DRS, PL and nitrogen adsorption–desorption techniques. The effect of the amount of AgNO3 on the morphology of the products was investigated and using the right amount of AgNO3 was essential to obtain the hollow and porous structure. A possible mechanism for the growth of the composites was proposed. The photocatalytic performance of the composites was evaluated for the degradation of methylene blue and rhodamine-B in an aqueous solution under visible-light irradiation. The Ag/BiVO4 composites showed excellent photocatalytic activity at a silver content of 6.5 wt%. The 6.5 wt% Ag/BiVO4 catalyst performed better than BiVO4 as well as better than the Ag-doped BiVO4 prepared by a photoreduction method. There is a strong relationship between photocatalytic performance and the structure of catalysts. It was deduced that the excellent photocatalytic activity of 6.5 wt% Ag/BiVO4 is due to its hollow and porous structure, large specific surface area, and Ag/BiVO4 interfaces.

A novel quaternary mercury and cadmium chalcogenidehalide, (Hg2Cd2S2Br)Br (1), has been prepared by solid-state reaction and structurally characterized by single crystal X-ray diffraction analysis. The structure of 1 is composed of parallel slabs stacking with -ABAB- mode via linearly coordinated Hg atoms to form a 3D cationic network with the channels being occupied by discrete Br anions, in which the slab consists of interlinks of linear (HgS2Br2) tetrahedral chains and (CdS2Br) trigonal chains. The optical properties were investigated in terms of the diffuse reflectance and Fourier transform infrared spectra. The electronic band structure along with density of states (DOS) calculated by DFT method indicates that the present compound is a semiconductor with an indirect band gap, and that the optical absorption is mainly originated from the charge transitions from Br-4p and S-3p to Cd-5s and Hg-6s states.

The principal resin-based adhesives prepared in China are complex aromatic methacrylates. The polyfunctional monomers of methacrylate are always selected and used as diluent. Activator (aromatic tertiary) and initiator (benzoyl peroxide) are used as the redox system in these materials. Benzoin methyl ether is frequently used as the ultraviolet light (u.v.) initiator. The powders of silicate, glass and ceramics treated with a silane agent are used as the inorganic filler in the composite resin. The products of these materials are EB type, 617 type, Ho-I type of the powder-liquid system and two-paste system. All these materials have been used in dental clinics. In addition, pure resin without filler may be applied alone as an adhesive, such as EM self-curing fissure sealant. Enamel bonding agent and u.v. activated fissure sealant may also be combined with composite resin to form a bonding system. The other kinds of adhesives are polymethyl methacrylates with an activator of tributylboron complex. The typical product of this system is 721 composite. Dicyanoacrylate and NPG-type coupling agent are undergoing study.