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The ultraviolet radiation resistance-associated gene (UVRAG) protein binds to the Beclin 1/PI3-kinase III complex and promotes autophagy. Autophagy may be upregulated by endoplasmic reticulum (ER) stress. Persistent and excessive ER stress may alter synovial fibroblast apoptosis and this alteration may affect the pathogenesis of rheumatoid arthritis (RA). In this study, we investigated whether UVRAG genetic polymorphisms are associated with RA. To determine the association between UVRAG polymorphisms and RA, we genotyped five UVRAG single-nucleotide polymorphisms (SNPs; rs7111334, intron C/T; rs7933235, intron A/G; rs1380075, intron T/A; rs1458836, near the 5′ gene terminal G/A; and rs636420, exon 15 C/T) using a direct sequencing method in 243 RA patients and 417 control subjects. Among these, one SNP (rs7111334) exhibited significant genotypic/allelic differences between RA patients and the control group. Therefore, this study suggested a possible association between UVRAG polymorphisms and RA susceptibility.

A brief history of catalysis community in Korea was reviewed together with examples of catalysts and catalytic processes developed by Korean industries. The Korea–Japan symposium on catalysis was introduced as one of successful examples of bilateral symposia co-organized by Korea.

Supported zirconocene catalysts on a new support, MgO, were prepared and tested in ethylene polymerization. Three types of impregnation methods were employed to find an optimum supporting method for MgO. The direct impregnation of Cp 2 ZrCl 2 on MgO showed low metal loading and polymerization activity, while the catalyst had a higher metal loading and polymerization activity when MgO was treated with methylaluminoxane (MAO) before supporting. Treatment of MgO with MAO during the supporting step invoked two types of catalytic sites, which was evidenced by the bimodal molecular weight distribution of the polymer products. MgO is considered to have potential as a support for metallocenes.

MgCl2–alcohol adduct for use as a catalyst support was prepared by the recrystallization method using alcohol as the dissolution material. The alcohol contents in the support are an important factor in catalysts impregnation. The prepared support was modified by treatment with alkylaluminum compounds. In terms of the treatment of the prepared support, triisobutylaluminum was an excellent pretreatment material. The polymerization of ethylene with 1-hexene was performed over homogeneous and heterogeneous metallocene catalysts. The molecular weight (Mw) and molecular weight distribution (MWD) of copolymers produced by the heterogeneous catalyst were higher and broader than those by homogeneous catalyst.

Inorganic support, MgCl2-alcohol adduct, for use in the impregnation of organometallic catalysts, was prepared by the recrystallization method using alcohol. Since MgCl2-alcohol adduct has two functional groups in the molecule, i.e., hydroxyl (-OH) and chlorine (-Cl) groups, it is suitable for the impregnation of both metallocene and Ziegler-Natta hybrid catalysts. The hybrid catalysts were prepared in order to control the molecular weight (Mw) and the molecular weight distribution (MWD) in ethylene polymerization. The polyethylene produced by the Ziegler-Natta/Metallocene hybrid catalysts showed two melting temperatures and a bimodal MWD, corresponding to products arising from each of the individual catalysts. This suggests that these hybrid catalysts acted as individual active species and produced a blend of polymers.

In order for successful application of heteropolyacids (HPAs) as heterogeneous catalysts to liquid-phase lactonization of 1,4-butanediol, H 3+ x PMo 12− x V x O 40 ( x =0–3) HPAs were immobilized on polyaniline (PANI) by one-step and two-step methods. Aniline was polymerized in the presence of HPA in the one-step preparation method, while HPA was immobilized on the ready-made PANI support in the two-step method. It was found that HPAs were molecularly dispersed and strongly immobilized in/on the PANI support as charge-compensating components. Most HPAs in the two-step HPAPANI catalysts were immobilized only on the surface of PANI support. The surface areas of the two-step HPAPANI catalysts were much higher than those of the one-step catalysts, which is important from the practical point of applications. Thermal stability of PANI support was much enhanced by the binding with HPA, and thermal stability of the two-step HPAPANI catalysts was superior to the one-step catalysts. In the lactonization of 1,4-butanediol, catalytic activities were in the following order: two-step HPAPANI>one-step HPAPANI>unsupported HPA; H 6 PMo 9 V 3 O 40 PANI>H 5 PMo 10 V 2 O 40 PANI>H 4 PMo 11 V 1 O 40 PANI>H 3 PMo 12 O 40 PANI. High activity of V-containing two-step catalysts and easiness of catalyst recovery in the liquid-phase reaction make them good candidates for an energy-saving lactonization process of 1,4-butanediol.

Propylene aromatization reaction was performed on various MFI type zeolites containing Ga species. The Ga was introduced into the zeolites by substitution (Ga-MFI), ion exchange (GIZ) and physical mixing (GPZ). A com-mercialized zeolite (PQZSM-5) was also used for comparison. The catalysts prepared were characterized by using XRF, XPS, surface area measurement, NH3-TPD, and H2-TPR. Through the Ga substitution, the acidity of the modified catalysts was decreased, and dehydrogenation and aromatization reactions occurred more easily. The lattice Ga did not react well with hydrogen contrary to the Ga located at the outside of the lattice. It was also found that Ga-MFI catalysts facilitate alkylation reactions.

In this work, H 3 PMo 12 O 40 -polymer composite film catalysts were prepared by a membrane preparation technique by blending H 3 PMo 12 O 40 with polymers using a mixed solvent of methanol(M)–chloroform(C) or ethanol(E)–chloroform(C). Polyphenylene oxide (PPO) and polysulfone (PSF) were used as blending polymers because of their excellent thermal and mechanical stability. The composite film catalysts were cut into small pieces, and applied as heterogeneous catalysts to the liquid-phase TBA( tert -butyl alcohol) synthesis and to the vapor-phase ETBE (ethyl tert -butyl ether) synthesis. It was observed that H 3 PMo 12 O 40 was finely dispersed throughout the polymer supports, and the blending patterns of the composite film catalysts were different depending on the identity of polymer material used. In the liquid-phase TBA synthesis, catalytic activities were in the following order; H 3 PMo 12 O 40 -PPO-MC>H 3 PMo 12 O 40 -PSF-MC>homogeneous H 3 PMo 12 O 40 . Not only high absorption capability of H 3 PMo 12 O 40 -PPO-MC for isobutene but also high stability of H 3 PMo 12 O 40 -PPO-MC during the reaction was responsible for its enhanced catalytic performance. In the vapor-phase ETBE synthesis, catalytic activities were in the following order; H 3 PMo 12 O 40 -PPO-EC>H 3 PMo 12 O 40 -PSF-EC>bulk H 3 PMo 12 O 40 . It was revealed that the residual ethanol in the composite film catalysts played an important role to improve and maintain the catalytic activities of the composite film catalysts.

Experimental studies on the design of shell- and tube-type heteropolyacid (HPA)-polymer composite catalytic membrane reactors (CMR) and their applications to the vapor-phase decomposition of methyl tert-butyl ether (MTBE) were reported. H3PW12O40 (PW) was used as a catalyst for the reaction, and polyphenylene oxide (PPO) was used as a membrane material. It was found that the single-phase (PW-PPO/Al2O3, type-1) and the composite (PW-PPO/PPO/Al2O3, type-2) catalytic membranes not only showed catalytic reactivity for the reaction, but also were perm-selective for methanol with respect to isobutene and MTBE. The selective removal of methanol through the catalytic membrane inhibited the unfavorable reverse reaction (MTBE synthesis), and at the same time accelerated the MTBE decomposition reaction. The PW-PPO/PPO/Al2O3 CMR showed a superior performance compared to the PW-PPO/Al2O3 CMR. The enhanced performance of PW-PPO/PPO/Al2O3 CMR was attributed to the intrinsic perm-selective capabilities of the PW-PPO catalytic membrane and the sub-layered PPO membrane. The PW-PPO/PPO/Al2O3 catalytic membrane with high PW loading was less perm-selective than that with low level of PW loading. Although the PW-PPO catalytic layer itself had a lower intrinsic activity than the bulk PW catalyst in a normal reactor, PW-PPO/PPO/Al2O3 catalytic membrane could be utilized in a membrane reactor to achieve higher MTBE conversions than equilibrium values by means of chemical equilibrium shift at high cut-off.

The catalytic partial oxidation of CH4 to syngas was carried out over an Ni–Mg/Al mixed-oxide catalyst prepared from layered double hydroxide-type precursors. The catalysts were characterized by XRD, TPR, UV-DRS, XRF, BET and CHNS analysis. The effects of the catalyst composition and the calcination temperature on the catalytic performance and the extent of catalyst deactivation were investigated. Ni–Mg/Al oxide catalysts converted CH4 into syngas efficiently with high selectivity. The catalyst performance was strongly related to the Ni particle size and the calcination temperature. The catalysts that were calcined at higher temperature exhibited a better catalytic performance. In conclusion, the NiAl2O4 spinel phase had a positive effect on the stability of the catalyst.

Sr4Ti3O10, which is known to have a Ruddlesden-Popper phase as a layered perovskite-type oxide, showed activity leading to the decomposition of pure water into H2 and O2 without any co-catalyst, when irradiated with light under 395 nm. When NiO x was loaded onto Sr4Ti3O10 both by the impregnation (I) method and the vapor deposition (VD) method, this photocatalytic activity drastically increased. Nickel acetylacetonate, when used with the VD method, was found to give rise to more efficient photocatalytic activity than that obtained using nickel nitrate with the impregnation method.

H3PMo12O40-polysulfone and H3PMo12O40-polyphenylene oxide composite film catalysts were prepared by a membrane preparation technique. They showed the higher catalytic activities than H3PMo12O40 in the vapor-phase synthesis of ethyl tert-butyl ether.

The hydrodechlorination of 1,1,2-trichloroethane (TCEA), which is one of the chlorinated organic wastes produced in the ethylene dichloride process, to vinyl chloride monomer (VCM) was carried out over Ni–Cu/SiO2 catalysts. The effects of added metals from IB group and the Cu content on the performance of the bimetallic catalysts were systematically investigated. Of the screened bimetallic catalysts tested, Ni–Cu/SiO2 catalysts efficiently converted TCEA into VCM in 95% or higher selectivity. Cu in Ni–Cu/SiO2 reduced the metal particle size and weakened the adsorption strength of Ni, and led to low conversion of TCEA and a high VCM selectivity. A series of CO–IR and extended X-ray absorption fine structure (EXAFS) measurements revealed that added Cu had no effect on the electronic structure of Ni and that Cu altered the geometric nature of Ni–Cu/SiO2 catalyst. HCl converted metallic Ni to NiCl2 and Cu to CuCl to modify the crystal structure. Cu played a role in the cooperation with Ni in the hydrodechlorination of TCEA, serving as other than an inert spacer.

The taxonomic position of an isolate that was recovered from a gold mine cave near Kongju, Republic of Korea, was determined by 16S rDNA sequence studies and chemotaxonomic characterization. Comparative studies of 16S rDNA sequences indicated that this organism was phylogenetically related to members of the genus Pseudonocardia, branching outside a cluster encompassing Pseudonocardia autotrophica and Pseudonocardia compacta. The affiliation to the genus was also supported by the cell chemistry, which was represented by a type IV cell wall, MK-8(H4) as the major menaquinone, a phospholipid type PIII pattern (phosphatidylcholine as a diagnostic phospholipid) and a DNA G+C content of 71 mol%. The fatty acid profile contained saturated, unsaturated and 10-methyl branched fatty acids, but tuberculostearic acid and hydroxy fatty acids were not present. The isolate differed from its phylogenetic neighbours in the presence of phosphatidylethanolamine, dodecanoate, 16-methylheptadecenoate and 16-methylheptadecanoate and the absence of phosphatidylinositol mannoside and phosphatidylmethylethanolamine. The unique combination of physiological properties, the cellular fatty acid profile and DNA-DNA hybridization data indicates that this organism is readily differentiated from the type strains of all of the validly published species of the genus Pseudonocardia. The name Pseudonocardia kongjuensis sp. nov. is proposed for the type strain, LM 157T (= IMSNU 50583T = KCTC 9990T = DSM 44525T).

Experimental studies on the performance of shell and tube-type membrane reactors equipped with heteropolyacid-polymer composite catalytic membranes were carried out for the vapor-phase decomposition of MTBE (methyl tert -butyl ether). Three types of catalytic membranes comprised of 12-tungstophosphoricacid (H 3 PW 12 O 40 , PW) and polyphenylene oxide (PPO) were designed in this work. The PW-PPO/Al 2 O 3 (type-1), PW-PPO/PPO/Al 2 O 3 (type-2) and PW/PPO/Al 2 O 3 (type-3) catalytic membranes not only showed catalytic reactivity for the reaction, but also were perm-selective for the reaction species. The selective removal of methanol through the catalytic membrane led to an equilibrium shift in a direction favorable to MTBE decomposition. Among three types of catalytic membrane reactor, the PW-PPO/PPO/Al 2 O 3 (type-2) catalytic membrane reactor showed the best performance. The enhanced performance of the PW-PPO/PPO/Al 2 O 3 (type-2) catalytic membrane reactor can be attributed to the intrinsic perm-selective capabilities of the PW-PPO catalytic membrane and the sub-layered PPO membrane.

In this work, H3PMo12O40 (PMo) and Cs2.75H0.25PMo12O40 (CsPMo) were modified via the polymerization of tetrahydrofuran (THF), followed by thermal treatment to be used as model catalysts for the oxidative dehydrogenation of isobutyric acid (IBA) into methacrylic acid (MAA). The THF-treated catalysts retained partially reduced stable structures with high surface areas. The THF-treated catalysts showed higher IBA conversions and MAA yields than the corresponding mother catalysts. The THF-treated CsPMo catalyst showed the best catalytic performance among the catalysts tested. It is concluded that the high surface area, the suitable acidity, and the partially reduced stable structure of the THF-treated CsPMo catalyst were responsible for this catalytic performance.

A kinetic study on the vapor-phase MTBE decomposition over H3PW12O40/SiO2 was carried out. Possible kinetic mechanisms are proposed and discussed. Rate expressions were ultimately developed after several verification processes.

Two types of inorganic supports, MgCl2 and SiO2, for the impregnation of catalysts were prepared by the recrystallization and the sol–gel method, respectively. The polyethylene produced by the Ziegler–Natta/metallocene hybrid and mixed catalysts showed two melting temperatures and a bimodal MWD corresponding to products arising from each of the individual catalysts. This suggests that these Ziegler–Natta/metallocene catalysts acted as individual active species, and as a result, produced a blend of polymers.

Two types of inorganic supports, MgCl2 and SiO2, for use in the impregnation of catalysts, were prepared by the recrystallization and the sol–gel methods, respectively. The Ziegler–Natta/Metallocene hybrid and mixed catalysts were prepared in order to control the molecular weight (Mw) and the molecular weight distribution (MWD) during ethylene polymerization. The polyethylene produced by the Ziegler–Natta/Metallocene hybrid and mixed catalysts showed two melting temperatures and a bimodal MWD, corresponding to products arising from each of the individual catalysts. This suggests that these Ziegler–Natta/Metallocene catalysts acted as individual active species and produced a blend of polymers.

Expression of the Na+-coupled glucose cotransporter SGLT1 is regulated post-transcriptionally at the level of mRNA stability. We have previously demonstrated that cAMP-dependent stabilization of the SGLT1 message was correlated with the protein phosphorylation-dependent binding of cytoplasmic proteins to a uridine-rich sequence (URE) in the 3′-untranslated region (UTR). In the present study, the regulatory role of the URE was demonstrated by inserting it into the 3′-UTR of a β-globin reporter minigene under the control of the tetracycline-regulated promoter. The resultant chimeric globin/SGLT1 mRNA expressed after transfection into LLC-PK1 cells exhibited a decreased half-life compared with the β-globin control, indicating that the URE serves a destabilizing function. Activation of protein kinase A stabilized the chimeric message but not the β-globin control, indicating the presence of a regulatory stabilizing sequence within the URE. A 38-kDa nucleocytoplasmic protein was identified that recognized a 12-nucleotide binding site within the URE. A mutation in this binding site that prevented protein binding assayedin vitro by UV cross-linking also prevented protein kinase A-dependent stabilization of the chimeric message assayedin vivo. These findings identify the interaction between a 38-kDa nucleocytoplasmic protein and a regulatory uridine-rich sequence in the 3′-UTR as critical for cAMP-mediated SGLT1 message stabilization.

The vapor-phase MTBE decomposition was examined in a shell and tube-type catalytic membrane reactor (CMR). 12-Tungstophosphoric acid (PW) was used as a catalyst and poly-2,6-dimethyl-1,4-phenylene oxide (PPO) was used as a polymer material. A single-phase CMR (PW-PPO/Al2O3, type-1) and a composite CMR (PW-PPO/ PPO/ Al2O3, type-2) were successfully designed and characterized. It was revealed that the single-phase PW-PPO/ Al2O3 showed perm-selectivities for reaction products. The selective removal of methanol through the catalytic membrane shifted the chemical equilibrium toward the favorable direction in the MTBE decomposition. The PWPPO/ PPO/ Al2O3 showed the better performance than PW-PPO/ Al2O3. The enhanced performance of PW-PPO/ PPO/ Al2O3 CMR was due to the intrinsic perm-selectivity of PW-PPO and the additional separation capability of sub-layered PPO membrane.

Nanoscale characterization of the acid properties of H 3 PMo 12− x W x O 40 ( x = 0, 3, 6, 9, 12) was carried out by scanning tunneling microscopy (STM) and tunneling spectroscopy. Pyridine binding with the acid sites of heteropolyacids (HPAs) was reflected in both the STM images and FT-IR spectra of these materials. All the HPAs investigated formed well-ordered monolayer arrays on highly oriented pyrolytic graphite (HOPG) before and after pyridine adsorption. Exposure to pyridine increased the lattice constants of the two-dimensional HPA arrays by ca. 6 A. Exposure to pyridine also shifted the negative differential resistance (NDR) peak voltages of HPAs to less negative values in the tunneling spectroscopy measurements. The NDR shifts of HPAs obtained before and after pyridine adsorption were correlated with acid properties of HPAs for the first time, suggesting that tunneling spectra measured by STM could serve to fingerprint acid properties of HPAs.

Simulation and experimental studies on the double pipe (shell and tube) polymer membrane reactors were examined for the vapor-phase methyl tert-butyl ether (MTBE) decomposition. H3PW12O40 catalyst supported on silica was used as an active catalyst for the reaction. Polyphenylene oxide (PPO), polysulfone (PSF) or cellulose acetate (CA) membrane coated on the double-layered alumina tube was used as a constituent membrane. It was observed that permeabilities of methanol through each polymer membrane were higher than those of isobutene and MTBE regardless of the kind of polymer material used. The selective removal of methanol through polymer membrane shifted the chemical equilibrium toward a favorable direction in the model reaction. The MTBE conversions in the membrane reactors were much enhanced compared to the equilibrium conversions. The PPO membrane reactor showed the best performance under the experimental conditions. The simulation results on the performance of the membrane reactors were in good agreement with the experimental results within the error of ±5%. It was revealed from the simulation that the CA membrane reactor showed the best performance at high contact time whereas the PPO membrane reactor showed the best performance at low contact time in terms of MTBE conversion, isobutene yield and isobutene selectivity. It was also observed that the performance of membrane reactor was much improved with the decrease of coating amount of polymer membrane and reaction temperature, but with the increase of partial pressure of MTBE. It was concluded that the simulation program developed in this work described the performance of the membrane reactor very well for the vapor-phase MTBE decomposition.

Two types of inorganic supports, MgCl2 and SiO2, for the impregnation of catalysts were prepared by the recrystallization and sol-gel methods, respectively. The Ziegler-Natta/Metallocene hybrid catalysts were prepared in order to control the molecular weight (Mw) and the molecular weight distribution (MWD) during ethylene polymerization. The polyethylene produced by the hybrid catalysts can control the Mw and the MWD of polymer, showing two melting temperatures and a bimodal MWD, corresponding to products arising from each of the individual catalysts. This suggests that these hybrid catalysts acted as individual active species and produced a blend of polymers.

Simulation and experimental studies on the polymer membrane reactor were examined for the vapor-phase MTBE (methyl tert-butyl ether) decomposition. A double pipe (shell and tube type) membrane reactor comprising 12-tungstophosphoricacid catalyst and polymer membrane was designed. The polymer membrane was coated on the porous alumina tube. Polyphenylene oxide (PPO), polysulfone (PSF) or cellulose acetate (CA) was used as a constituent membrane material. It was observed that permeabilities of methanol through each polymer membrane were higher than those of isobutene and MTBE regardless of the kind of polymer membrane used. The selective permeation of methanol through each polymer membrane shifted the chemical equilibrium toward the favorable direction in the MTBE decomposition reaction. MTBE conversions in the membrane reactors were much enhanced compared to the equilibrium conversions. The MTBE conversions were increased with the increase of reaction temperature and with the decrease of reaction pressure. Simulated results were in good agreement with the experimental results. The PPO membrane reactor showed the best performance in the experimental condition.

A silica support for use in olefin polymerization was prepared by the gelation of a stable, colloidal phase of silica sol using a MgCl2 solution as the initiator. The Ziegler-Natta/Metallocene hybrid catalysts prepared using this support exhibited characteristics of both Ziegler-Natta and metallocene catalysts. The polymers produced by the hybrid catalysts showed a bimodal molecular weight distribution pattern and two different melting points, corresponding to products arising from each catalyst. This suggests that the hybrid catalysts acted as individual active species and produced a blend of polymers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2318–2326, 2000

The hydrodechlorination of 1,2‐dichloropropane (DCPA), a chlorinated organic waste which is produced in the epichlorohydrin process, to propylene was carried out over Ni/SiO2 catalysts. The effects of Ni loading and calcination temperature on catalyst performance and catalyst deactivation of Ni/SiO2 were systematically investigated. The Ni/SiO2 catalysts efficiently converted DCPA into propylene in 95% selectivity or higher. The particle size of Ni on SiO2 was strongly related to the catalyst stability. In terms of the effect of Ni loading, the largest Ni particles on SiO2 showed the best durability against deactivation. A series of TPR and UV‐DRS measurements revealed that nickel hydrosilicate was formed as the result of the interaction between Ni and SiO2. Nickel hydrosilicate was found to be responsible for the catalyst stability leading to low catalyst deactivation. HCl adsorption on Ni/SiO2 was the main reason for catalyst deactivation. HCl modified the crystal structure of metallic Ni to NiCl2 and led to irreversible deactivation and metal sintering.

A metallocene catalyst or a metallocene/Ziegler-Natta hybrid catalyst supported on MgCl2 was studied for application to the commercial slurry phase process and to the control of MWD of the polymer produced. The MgCl2 support was prepared by the recrystallization method with different solvents: alcohols and H2O. The recrystallized MgCl2 support was pretreated with triisobutylaluminum (TiBAL) or trimethylaluminum (TMA), methylaluminoxane (MAO), to give different supporting environments. Metallocene/Ziegler-Natta hybrid catalysts on MgCl2 were prepared by first supporting the metallocene catalyst, followed by the Ziegler-Natta catalyst after pretreatment with an alkylaluminum compound. The type of solvent plays a role in providing a suitable environment in the support for impregnating catalysts. The hybrid catalyst, whose support was recrystallized in n-propanol (n-PrOH) and pretreated with TiBAL, showed the highest molar ratio of Zr/Ti= 1/2.71. But the hybrid catalyst, whose support was recrystallized in H2O and pretreated with MAO, showed the best hybrid effect showing a variety of bimodal peaks in proportion to the ratio of MAO/TEA in GPC analysis. This effect might be due to steric factor and polarity of solvent, as well as the pretreatment material. It is concluded that the MWD of polyethylene produced by metallocene/Ziegler-Natta hybrid catalyst that is supported on MgCl2 can be controlled by regulating the amounts of MAO and TEA added as cocatalysts and by the use of different solvents and pretreatment materials.

Ziegler–Natta and metallocene hybrid catalysts were impregnated on a bisupport prepared by the polymerization of colloidal phase of SiO2 using MgCl2 solution as an initiator. The prepared bisupport was modified by treatment with alkyl aluminum compounds. In terms of the treatment of the prepared bisupport, trimethylaluminum (TMA) was superior to methylaluminoxane (MAO) with respect to the stability of the metallocene catalyst. The prepared hybrid catalysts exhibited characteristics of both Ziegler–Natta and metallocene catalysts. The polyethylene produced on the hybrid catalysts showed a bimodal molecular weight distribution in GPC profile and two different melting points in differential scanning calorimetry (DSC) thermogram.

H3PMo12O40-polymer composite film catalysts were prepared by blending these two materials using a methanol–chloroform mixture by a membrane preparation technique. Polyphenylene oxide (PPO), polyethersulfone (PES) and polysulfone (PSF) were used as blending polymers. A H3PMo12O40-PPO composite catalyst coated on Al2O3 was also prepared. These catalysts were used as heterogeneous catalysts for the liquid-phase tert-butanol (TBA) synthesis from isobutene and water. It was found that all the composite film catalysts showed higher catalytic activities than homogeneous H3PMo12O40 in the TBA synthesis. Among the composite film catalysts, H3PMo12O40-PPO showed the best catalytic performance. Not only high absorption capability of H3PMo12O40-PPO for isobutene but also stability of H3PMo12O40-PPO in the reaction medium was responsible for such a catalytic performance. The H3PMo12O40-PPO/Al2O3 also showed a higher activity than a homogeneous solution of H3PMo12O40.

MgCl2 for use as a catalyst support was prepared by dissolution in methanol and recrystallization in n-decane, followed by vacuum-drying at 2,000 rpm. The prepared support was modified by treatment with alkylaluminum compounds. The activity profile of ethylene over the supported catalysts persisted for periods up to 1 h during the polymerization. The prepared Ziegler–Natta/metallocene hybrid catalysts exhibited the characteristics of both metallocene and Ziegler–Natta catalysts. The polymer produced by the hybrid catalysts gave bimodal peaks in differential scanning calorimetry analysis for ethylene and ethylene/1-hexene polymerization, suggesting that the polymer was composed of two different lamellar structures that were polymerized by each catalyst. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1707–1715, 1998

Nanoscale images and tunneling spectra of cation-exchanged or polyatom-substituted heteropolyacids (HPAs) were probed by scanning tunneling microscopy (STM) at room temperature. All the HPAs formed two-dimensional ordered arrays on graphite surfaces, and their molecular dimensions were in good agreement with values determined by X-ray crystallography. It was observed that the negative differential resistance (NDR) peak voltage measured by STM was closely related to the reduction potential of the corresponding bulk HPA. The higher the reduction potential of the HPA, the lower the applied voltage at which NDR was observed.

H3PMo12O40-polysulfone composite film catalysts were prepared with a membrane preparation technique by blending these two materials using dimethylformamide or methanol–chloroform mixture. They were used as fixed-bed catalysts for the vapor-phase ethanol conversion in a continuous flow reactor. It was observed that H3PMo12O40was finely dispersed throughout a polysulfone matrix. The composite catalysts showed the modified catalysis compared to the bulk acid. The effects of solvent on the pore characteristics and catalytic activities of these composite film catalysts were investigated.

Mg-ZSM-22, dealuminated by steaming or washing with nitric acid, was prepared and investigated as a catalyst for the skeletal isomerization of 1-butene to isobutene in a fixed bed flow reactor. The prepared catalysts were characterized by XRD, NH3-TPD, FT-IR, XPS, ICP, and FT-NMR. Steaming led to a significant decrease in acidity. Higher steaming temperatures removed more aluminum ions in tetrahedral sites and reduced the acidity. Both Bronsted acid sites and Lewis acid sites are reduced by steaming. The catalytic activities of steamed Mg-ZSM-22 were poorer than for untreated Mg-ZSM-22. Acid-washing with dilute nitric acid was effective for this reaction and showed enhanced activities. Strong acid sites, on which induced side reactions and coke deposition mainly occurred, were selectively removed and Lewis acidity, which is responsible for improvement in catalytic activity, was also generated by the treatment of Mg-ZSM-22 with dilute nitric acid.

Mg-ZSM-22, modified by the deposition of silicon ethoxide, was prepared and investigated as a catalyst for the skeletal isomerization of 1-butene to isobutene in a fixed-bed flow reactor. The prepared catalysts were characterized by XRD, TPD, SEM-EDX, ICP and FT-IR. The deposition of silicon alkoxide on Mg-ZSM-22 led to a decrease in the amount of strong acid sites, confirmed by TPD experiments with ammonia and γ-collidine. The treatment also affected the size of pore opening, as evidenced by constraint index measurement and chemisorption experiment using \(n\)-hexane. As the deposition time increased, the conversion of 1-butene decreased as the result of reduced acidity, while selectivity to isobutene increased. The deposition of silicon alkoxide resulted in the suppression of side reactions and coke deposition, thus enhancing the skeletal isomerization. The modification of Mg-ZSM-22 by deposition of silicon alkoxide was very effective in terms of catalytic stability and coke removal.

The MgCl2 supports for an ethylene polymerization catalyst were prepared by the recrystallization method using methanol as a solvent. The effects of different desolvation methods of the recrystallized MgCl2-alcohol adduct on the morphological characteristics of the catalysts were examined. The desolvation method greatly affects the characteristics of the catalyst. The prepared catalysts had different Ti/Mg ratios with respect to both surface content and entire catalyst particles. Considering Ti distribution and activity profiles, not only the polymerization conditions but also the Ti distribution on the catalyst appear to be an important factor which affects the bulk density of the polymers. MgCl2-Trager fur einen Ethylenpolymerisationskatalysator wurden mit Hilfe der Rekristallationsmethode hergestellt, wobei Methanol als Losungsmittel diente. Der Einflus verschiedener Losungsmethoden des rekristallisierten MgCl2-Alkohol-Adduktes auf die morphologischen Charakteristika der Katalysatoren wurde untersucht. Die Losungsmethode beeinflust die Eigenschaften der Katalysatoren betrachtlich. Die dargestellten Katalysatoren wiesen unterschiedliche Ti/Mg-Verhaltnisse auf, sowohl was die Oberflache als auch die gesamten Katalysator-Partikel betrifft. Betrachtet man die Ti-Verteilung und Aktivitatsprofile, dann erweisen sich nicht nur die Polymerisationsbedingungen, sondern auch die Ti-Verteilung auf dem Katalysator als wichtige Faktoren, welche die Dichte der Polymeren beeinflussen.

ZSM-22s, ion-exchanged with various cations, were prepared and examined as catalysts with respect to the skeletal isomerization of 1-butene to isobutene in a continuous flow reactor. Mg-ZSM-22 gave the best yield for isobutene. The order of the catalysts with respect to the yield for isobutene was proportional to the ratio of Lewis acidity to Bronsted acidity. The Lewis acid site was found to be responsible for improvement in catalytic activity, as well as suppression of coke formation. The role of Lewis acidity in the skeletal isomerization of 1-butene was confirmed by experiments involving the addition of water to the feed. The effect of impregnated boron or phosphorus was clearly observed. Phosphorus poisoned not only the strong acid sites, but also the active sites responsible for the skeletal isomerization of 1-butene, while boron mainly poisoned the strong acid sites, which resulted in a decrease in side reactions and an increase in isobutylene selectivity.

Heteropolyacid-imbedded polymer film catalysts were applied for the vapor-phase catalytic reaction. Thin film catalysts were prepared by membrane technology using homogeneous heteropolyacid-polymer solutions. It was found that heteropolyacid was finely and uniformly dispersed throughout the polymer matrix. Heteropoly-acid catalyst could be designed by this method to enhance acid or oxidation catalysis. Future aspects of the film catalyst were also described in this work.

Membrane-like H 3 PMo 12 O 40 or H 5 PMo 10 V 2 O 40 -imbedded polymer films were prepared by blending these materials using a chloroform-methanol mixture as solvent, and they were tested as catalysts for the ethanol conversion reaction in a continuous flow fixed-bed reactor. It was found that the chloroform-methanol mixture itself gave no influence on the catalytic activity of bulk H 3 PMo 12 O 40 and H 5 PMo 10 V 2 O 40 . Polysulfone, polyethersulfone and polyphenylene oxide were used as blending polymers in this study. H 3 PMo 12 O 40 -imbedded polymer films showed a higher catalytic activity than H 3 PMo 12 O 40 itself due to uniform and fine dispersion of H 3 PMo 12 O 40 through polymer films, but the extent of activity and selectivity was varied according to a kind of polymer materials. It was revealed that H 3 PMo 12 O 40 or H 5 PMo 10 V 2 O 40 -imbedded polyphenylene oxide film showed much higher oxidation catalytic activity than the corresponding bulk heteropoly acids. This may be due to the interaction (or bonding) of proton of heteropoly acid with polyphenylene oxide, judging from the fact that glass transition temperature of polyphenylene oxide was increased after blending with heteropoly acid. The catalytic activity of the heteropoly acid imbedded in the same polymer was greatly affected by the composite of heteropoly acid. The permeabilities of reactants through polymer films also affected the product selectivity.

(BiPb)2Sr2Ca2Cu3Ox superconductor powders were synthesized by the sol-gel method using an aqueous solution of metal nitrates containing polyacrylic acid and tartaric acid as chelating agents. The conditions of the sol formation were determined and the thermal decomposition process of the gel precursor was examined. The effect of sintering temperature on the particle morphology was also investigated. High purity Bi(Pb)-Sr-Ca-Cu-O superconducting oxide powders with high-Tc phase could be obtained and they exhibited sharp superconducting transition with zero temperature of 105 K.

The ultraviolet radiation resistance-associated gene (UVRAG) protein binds to the Beclin 1/PI3-kinase III complex and promotes autophagy. Autophagy may be upregulated by endoplasmic reticulum (ER) stress. Persistent and excessive ER stress may alter synovial fibroblast apoptosis and this alteration may affect the pathogenesis of rheumatoid arthritis (RA). In this study, we investigated whether UVRAG genetic polymorphisms are associated with RA. To determine the association between UVRAG polymorphisms and RA, we genotyped five UVRAG single-nucleotide polymorphisms (SNPs; rs7111334, intron C/T; rs7933235, intron A/G; rs1380075, intron T/A; rs1458836, near the 5′ gene terminal G/A; and rs636420, exon 15 C/T) using a direct sequencing method in 243 RA patients and 417 control subjects. Among these, one SNP (rs7111334) exhibited significant genotypic/allelic differences between RA patients and the control group. Therefore, this study suggested a possible association between UVRAG polymorphisms and RA susceptibility.

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

A solid electrolyte catalytic reactor was used to investigate the change in catalytic activity of the electrode upon conduction of O2−ions through the electrolyte. The reactor consisted of an yttria-stabilized zirconia electrolyte disk on which a thin film of the Ag electrode was deposited. As the catalyst potential was applied below the open circuit potential or, equivalently, as O2−ions were electrochemically removed from the Ag catalyst electrode to the counter electrode through the solid electrolyte, its influence on the O2exchange reaction in He–O2flow and CH3OH oxidation to HCHO and CO2in He–O2–CH3OH flow was investigated. It was found from the O2exchange reaction study that slow diffusion of adsorbed oxygen to the catalyst–electrolyte–gas three-phase boundary, where charge transfer took place, caused a limiting current. In CH3OH oxidation, a lowered open circuit potential was observed when CH3OH was added to the He–O2flow. Lowering the catalyst potential below this new open circuit potential was found to cause a reversible, somewhat nonfaradaic increase in the rate of CO2formation, but had little effect on the rate of HCHO formation. Based on the rate equations, this behavior was interpreted in terms of an activated surface reaction between adsorbed species due to the change in the catalyst work function with changing catalyst potential.

An MgCl 2 catalyst support for propylene polymerization was prepared by dissolving MgCl 2 in ethanol and/or l-propanol and recrystallizing it in an n -decane medium with vacuum drying. This support was modified by adding di- n -butyl phthalate as an internal electron donor, and subsequently TiCl 4 was impregnated on the modified support. The prepared support and the catalyst were characterized by GC, HPLC, SEM, and N 2 -BET surface analyser. Propylene was polymerized with the catalyst and triethyl-aluminium in the presence or absence of ethyl benzoate, and the effect of alcohol treatment on the catalytic activity and isotactic index (I.I.) was examined. It was found that the propanol-treated catalyst showed a better performance than the ethanol-treated catalyst, owing to different amounts of remaining organic compounds. When the amounts of remaining alcohols were the same, it was also revealed that propanol was effective in enhancing the I.I. and ethanol was effective in enhancing the catalytic activity.

H3PMo12O40 embedded in a polysulfone film was prepared by blending H3PMo12O40 with polysulfone using dimethylformamide as a common solvent and its catalytic activity for 2-propanol conversion reaction was examined. The prepared film catalyst showed a higher yield for acetone but a lower yield for propylene than H3PMo12O40 itself. The decrease of acidic function of the film catalyst was mainly due to dimethylformamide strongly adsorbed on the acid sites of H3PMo12O40, while the increase of oxidation function was due to uniformly and finely distributed H3PMo12O40 in the film. When the film catalyst was used as a membrane, it showed higher ratio of acetone to propylene than H3PMo12O40 itself.

The MgCl 2 support for a propene polymerization catalyst was prepared by the recrystallization method using ethanol as a solvent and ethyl benzoate as an internal electron donor. The recrystallized MgCl 2 was impregnated with TiCl 4 at various temperatures, and the effect of impregnation temperature on the catalytic activity and isotactic index (I. I.) of polypropene (PP) was investigated. It was found that ethanol and titanium chloride ethoxide (TCE) in the catalyst play an important role in the catalytic activity and I. I. The support treated with TiCl 4 at high temperatures showed good performance but large activity reduction during polymerization. The enhanced performance is mainly due to active Ti species containing small amounts of TCE. The large activity reduction is also mainly due to small amounts of ethanol and TCE, yielding small amounts of atactic sites with low Lewis acidity.

In this experimental study, the methyl tert.-butyl ether (MTBE) decomposition was carried out in various inert membrane reactors composed of H3PW2O40 and a polymer membrane. Polycarbonate (PC), polyarylate (PA) and cellulose acetate (CA) membranes were used in the membrane reactor. It was revealed that all the tested polymer membranes showed larger permeability of methanol than that of either MTBE or isobutene, and the membrane reactor showed better performance than the corresponding fixed bed reactor. The perm-selectivity of methanol/MTBE was in the order of CA > PC > PA, and the permeation ratio of product/MTBE was in the order of CA > PA > PC. Among the membrane reactors tested CA membrane reactor showed the best performance. The enhanced performance of the membrane reactor was mainly due to the selective permeation of methanol that made a methanol-deficient phase suppressing MTBE synthesis reaction in the reversible reaction.

The polarization behavior in HeO 2 atmosphere was studied on a Ag electrode deposited on yttria-stabilized zirconia (YSZ) solid electrolyte. It was seen that the open circuit potential followed the Nernst equation under experimental conditions. If the cathodic overpotential applied was lower than −100 mV, a limiting current was observed for a wide range of P O 2 and this was found to result from the interfacial diffusion of adsorbed oxygen. For P O 2 above 0.05 atm, however, a remarkably steep increase in currents was observed above a certain anodic overpotential. After this unexpected phenomenon had happened, the time required to attain a stable open circuit potential became longer and the cathodic limiting current increased by about ten times. To investigate the effect of anodic polarization on the Ag electrode, changes in the surface of the electrode before and after anodic polarization were examined by SEM and XPS, and the results showed that anodic polarization severely and irreversibly deformed the surface structure of the electrode. However, little change in the surface state was observed with polarization from the XPS analysis. The decomposition of the oxides which were formed during anodic polarization was presumed to result in a change in the surface structure, leading to an increase in cathodic limiting current.