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Ni/CeO2 catalysts with different Ni loadings (5, 7, 10, 12, and 14 wt% Ni) were prepared by an impregnation method and examined for the CO2 reforming of methane using flow and static reactors. Their catalytic activities and selectivities were measured under CO2 /CH4 /Ar (=5/5/40 cm3/min) flow at 450–800°C using a flow reactor system with an on-line gas chromatography. At fixed temperature, the CO2 and CH4 conversions varied only slightly with the Ni wt%, whereas the H2 /CO ratio increased with increasing Ni wt%. The conversions increased with temperature, reaching 98% at 800°C. The H2 /CO ratio varied with temperature in the range of 450–800°C, from less than 1 below 550°C to close to 1 at 550–600°C and then back to less than 1 above 600°C. The apparent activation energies were determined to be 43.1 kJ/mol for the CO2 consumption and 50.2 kJ/mol for the CH4 consumption based on the rates measured for the reforming reaction over 5 wt% Ni/CeO2 catalyst at 550–750°C. Additionally, the catalytic reforming reaction at low pressure (40 Torr) was investigated by a static reactor system by using a differential photoacoustic cell, in which the rates were measured from the CO2 photoacoustic signal data at early reaction times over the temperature range of 460–610°C. Apparent activation energies of 25.5–30.1 kJ/mol were calculated from the CO2 disappearance rates. The CO2 adsorption on the Ni/CeO2 catalyst was investigated by the CO2 photoacoustic spectroscopy and Fourier transform infrared spectroscopy. Feasible side reactions during the catalytic CO2 /CH4 reaction were suggested on the basis of the kinetic and spectroscopic results.

Study Objective Abdominal wall anatomy can be altered after transverse rectus abdominis myocutaneous flap (TRAM) procedure in patient with breast cancer and the umbilicus may be distorted. For this reasons, laparoscopic gynecologic surgery is difficult procedure including proper port placement, the knowledge of the residual blood supply to the abdominal wall and umbilicus. We present our experience performing single port access total laparoscopic hysterectomy and bilateral salpingo-oophorectomy (SPA-TLH BSO) on a woman after TRAM surgery. Design N/A Setting N/A Patients or Participants N/A Interventions 53 years old woman who were diagnosed with breast cancer got left modified radical mastectomy followed by the breast mound reconstruction with contralateral pedicled TRAM flap three years ago. she took two cycles of chemotherapy after surgery. Since then, she has been taking tamoxifen and referred to Gynecologic oncology department for growing uterine myoma. 8 × 7 cm sized uterine myoma on transvaginal sonography was observed. The patient was recommended with hysterectomy and bilateral salpingo-oophorectomy. Transumbilical SPA TLH and BSO were performed after confirming the pathway of the vessel of pedicle by Abdominal-pelvic CT. Measurements and Main Results After making of altered anatomy of abdominal muscle flap, self designed single port system was made using the wound retractor and a surgical glove on umbilicus. We did not make additional port placement to avoid damage of abdominal wall with previous TRAM procedure. patient underwent successful SPA TLH and BSO transumbilical incision for single port placement. There was no complication during operation. Conclusion Single port access laparoscopic surgery is feasible in women after TRAM reconstruction. Knowledge of anatomic and physiologic variations related to the TRAM procedure is necessary in planning a safe operation.

The four-dimensional cycle simulator, which can recognize whether the road is ascent or descent, its gradient, and status of its surface on Virtual Reality, is introduced in this paper. On the base of these recognitions, various virtual motion path situations are displayed on LCD monitor attached ahead. These various situations may support not only the sense of realty but also an interest in a game in opposition to previous exercise cycles that might be monotonous. In this paper both analysis and estimation of basic bodily abilities for the four-dimensional cycling are addressed. Key Words : 4D Cycling, Simulator, Health Care, Basic Body Ability Received 23 September 2013, Revised 15 October 2013Accepted 20 November 2013Corresponding Author: Ki-Bong Kim(The Society of Digital Policy) Email: kbkim@hit.ac.krⒸ The Society of Digital Policy & Management. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.otg/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is ISSN: 1738-1916 properly cited.

Layered metal hydroxides (LMHs) containing calcium were synthesized by coprecipitation in solution having two different trivalent metal ions, iron and aluminum. Two mixed metal solutions ( and = 2/1) were added to sodium hydroxide solution and the final pH was adjusted to ~11.5 and ~13 for CaAl-and CaFe-LMHs. Powder X-ray diffraction (XRD) for the two LMH samples showed well developed () diffractions indicating 2-dimensional crystal structure of the synthesized LMHs. Rietveld refinement of the X-ray diffraction pattern, the local structure analysis through X-ray absorption spectroscopy, and thermal analysis also confirmed that the synthesized precipitates show typical structure of LMHs. The chemical formulae, and were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Particle morphology and thermal behavior for the synthesized LMHs were examined by field emission scanning electron microscopy and thermogravimetricdifferential scanning calorimetry.

In order to investigate SAR regarding proximal phenyl ring in novel C-aryl glucoside SGLT2 inhibitors containing a thiazole motif, a series of chemical modifications on proximal phenyl ring was conducted. During a series of lead optimization efforts, ortho-allyloxyphenyl 10p or ortho-hydroxyphenyl 11a showed subnanomolar inhibitory activity against hSGLT2.

The diametral creep of pressure tubes (PTs) in CANDU (CANada Deuterium Uranium) reactors is one of the principal aging mechanisms governing the heat transfer and hydraulic degradation of the heat transport system (HTS). PT diametral creep leads to diametral expansion, which affects the thermal hydraulic characteristics of the coolant channels and the critical heat flux (CHF). The CHF is a major parameter determining the critical channel power (CCP), which is used in the trip setpoint calculations of regional overpower protection (ROP) systems. Therefore, it is essential to predict PT diametral creep in CANDU reactors. PT diametral creep is caused mainly by fast neutron irradiation, temperature and applied stress. The objective of this study was to develop a bundle position-wise linear model (BPLM) to predict PT diametral creep employing previously measured PT diameters and HTS operating conditions. The linear model was optimized using a genetic algorithm and was devised based on a bundle position because it is expected that each bundle position in a PT channel has inherent characteristics. The proposed BPLM for predicting PT diametral creep was confirmed using the operating data of the Wolsung nuclear power plant in Korea. The linear model was able to predict PT diametral creep accurately.

As a means of effectively managing severe accidents at nuclear power plants, it is important to identify and diagnose accident initiating events within a short time interval after the accidents by observing the major measured signals. The main objective of this study was to diagnose loss of coolant accidents (LOCAs) using artificial intelligence techniques, such as SVC (support vector classification) and GMDH (group method of data handling). In this study, the methodologies of SVC and GMDH models were utilized to discover the break location and estimate the break size of the LOCA, respectively. The 300 accident simulation data (based on MAAP4) were used to develop the SVC and GMDH models, and the 33 test data sets were used to independently confirm whether or not the SVC and GMDH models work well. The measured signals from the reactor coolant system, steam generators, and containment at a nuclear power plant were used as inputs to the models, and the 60 sec time-integrated values of the input signals were used as inputs into the SVC and GMDH models. The simulation results confirmed that the proposed SVC model can identify the break location and the proposed GMDH models can estimate the break size accurately. In addition, even if the measurement errors exist and safety systems actuate, the proposed SVC and GMDH models can discover the break locations without a misclassification and accurately estimate the break size.

Novel C-aryl glucoside SGLT2 inhibitors containing pyrimidine motif were designed and synthesized for biological evaluation. Among the compounds assayed, pyrimidine containing methylthio moiety 11 g demonstrated the best in vitro inhibitory activity against SGLT2 in this series to date (IC(50)=10.7 nM).

Summary We investigated whether the 2677G>T ⁄A and 3435C>T polymorphisms of adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1) affect the efficacy of ondansetron to prevent postoperative nausea and vomiting. One hundred and ninety-eight patients undergoing general anaesthesia were enrolled. Thirty minutes before the end of surgery, 0.1 mg.kg )1 ondansetron was administered intravenously. The incidence of postoperative nausea and vomiting was compared between genotypes in the 2677G>T ⁄A and 3435C>T polymorphisms of ABCB1. The incidence of postoperative nausea and vomiting was lower in patients with the 2677TT genotype (TT vs Non-TT = 25.9% vs 53.0%, p = 0.01) and 3435TT genotype (CC + CT vs TT = 52.6% vs 21.7%, p = 0.01) during the first 2 h after surgery. There were no significant differences in the incidence of postoperative nausea and vomiting between the different genotype groupings during period between 2 and 24 h after surgery. In conclusion, ABCB1 genotypes may be a clinical predictor of responsiveness for ondansetron.

The reaction catalyzed by Ni/silicon wafers was kinetically studied by using a photoacoustic technique. The catalytic reaction was performed at various partial pressures of and (50 Torr total pressure of ) in the temperature range of 500 - in a static reactor system. The photoacoustic signal that varied with the concentration during the catalytic reaction was recorded as a function of time. Under the reaction conditions, the photoacoustic measurements showed the as-prepared Ni thin film sample to be inactive for the reaction, while the reactions carried out in the presence of the sample pre-treated in at were associated with significant time-dependent changes in the photoacoustic signal. The rate of disappearance was measured from the photoacoustic signal data in the early reaction period of 50 - 150 sec to obtain precise kinetic data. The apparent activation energy for consumption was determined to be 6.9 kcal/mol from the disappearance rates. The partial reaction orders, determined from the disappearance rates measured at various and at , were determined to be 0.33 for and 0.63 for , respectively. Kinetic data obtained in these measurements were compared with previous works and were discussed to construct a catalytic reaction mechanism for the reaction over Ni/silicon wafer at low pressures.

In this study, α-Fe2O3 spherical particles with an average diameter of approximately 200 nm were synthesized by a solvothermal method for use as both a catalyst and medium for a Pd catalyst. The kinetics of CO oxidation over powders of α-Fe2O3 spherical particles and 14 wt % Pd/α-Fe2O3 spherical particles were measured in a static reactor by using a CO2 laser-based photoacoustic technique. The total pressure was fixed at 40 Torr for the CO/O2/N2 mixture for temperatures in the range of 225–350 °C. The variation in the CO2 photoacoustic signal with the CO2 concentration during CO oxidation was recorded as a function of time, and the CO2 photoacoustic data at the early reaction stage was used to estimate the rates of CO2 formation. Based on plots of ln(rate) vs. 1/T, apparent activation energies were calculated as 13.4 kcal/mol for the α-Fe2O3 submicron powder and 13.2 kcal/mol for the 14 wt % Pd/α-Fe2O3 submicron powder. Reaction orders with respect to CO and O2 were determined from the rates measured at various partial pressures of CO and O2 at 350 °C. The zero-order of the reaction with respect to Po2 was observed for CO oxidation over α-Fe2O3 submicron powder, while 0.48 order to Po2 was observed for CO oxidation over Pd/α-Fe2O3 submicron powder. The partial orders with respect to PCO were determined as 0.58 and 0.54 for the α-Fe2O3, and the Pd/α-Fe2O3 submicron powders, respectively. The kinetic results obtained from both catalysts were compared with those for the α-Fe2O3 fine powder catalysts and were used to understand the reaction mechanism.

The thermal reactor power in pressurized water reactors (PWRs) is typically assessed using secondary system calorimetric calculations based on accurate measurements of the feedwater flowrate. Therefore, precise measurements of the feedwater flowrate are essential. In most PWRs, Venturi meters are used to measure the feedwater flowrate. However, the fouling phenomena of the Venturi meter deteriorate the accuracy of the existing hardware sensors. Consequently, it is essential to resolve the inaccurate measurements of the feedwater flowrate. In this study, in order to estimate the feedwater flowrate online with high precision, a smart soft sensing model for monitoring the feedwater flowrate was developed using a group method of data handling (GMDH) algorithm combined with a sequential probability ratio test (SPRT). The uncertainty of the GMDH model was also analyzed. The proposed sensing and monitoring algorithm was verified using the acquired real plant data from Yonggwang Nuclear Power Plant Unit 3.

Numerous research groups have been engaged in searching for novel CB1 receptor antagonists, since SR141716A (rimonabant), a CB1 receptor antagonist, proved to be efficacious in human for the treatment of obesity. In the present study, a series of 1,2,4-triazole-containing diarylpyrazolyl carboxamides based on the 1,5-diarylpyrazole template of rimonabant, was synthesized and tested for CB1 receptor binding affinity. The structure-activity relationship studies demonstrated that incorporation of 1,2,4-triazole ring onto the pyrazole scaffold via a methylene linker led to a significant improvement for CB1 receptor binding affinity. Importantly, these analogues also exhibited excellent selectivity for CB1 receptor over CB2 receptor.

A photoacoustic spectroscopy technique was employed to the kinetic study of the CO 2 /CH 4 reaction catalyzed by Ni particles embedded into the mesochannels of SBA15. The catalytic CO 2 /CH 4 reaction was performed in a closed-circulating reactor system at various partial pressures of CO 2 and CH 4 (40 Torr total pressure) in the temperature range of 500–700 °C. The CO 2 photoacoustic signal that varied with the concentration of CO 2 during the catalytic reaction was recorded as a function of time by using a differential photoacoustic cell. Under the reaction conditions, the CO 2 photoacoustic measurements showed the SBA15 compound used as support to be inactive for the reaction. The CO 2 /CH 4 reaction carried out in the presence of the H 2 -reduced Ni/SBA15 catalyst showed significant time-dependent changes in the CO 2 photoacoustic signal, while the reaction performed in the presence of the as-prepared Ni/SBA15 catalyst did not. The CO 2 photoacoustic signal obtained at early reaction times provided precise data of the CO 2 disappearance rate. The rate of CO 2 disappearance was observed to increase with increasing temperature in the range of 500–700 °C. The apparent activation energy for the CO 2 consumption in the Ni/SBA15 catalyzed reaction was calculated to be 6.2 kcal/mol. Reaction orders, determined from initial rates of CO 2 disappearance at various P C O 2 ’s and P C H 4 ’s at 700 °C, were found to be 0.28 for CH 4 and 0.39 for CO 2 , respectively. The kinetic results were compared with those previously reported and were used to infer a catalytic reaction mechanism for the CO 2 /CH 4 reaction at low pressures.

The Venturi flow meters that are being used to measure the feedwater flow rate in most pressurized water reactors are confronted with fouling phenomena, resulting in an overestimation of the flow rate. In this paper, we will therefore develop two soft-sensing models based on a fuzzy inference system and support vector regression for online prediction of the feedwater flow rate. The data-based models are developed using a training data set and a verification data set, and validated using an independent test data set. These data sets are divided from the startup data of Yonggwang Nuclear Power Plant Unit 3. The data for training the data-based models is selected with the aid of a subtractive clustering scheme because informative data increases the learning effect. The uncertainty of the data-based models is analyzed using 100 sampled training and verification data sets, and a fixed test data set. The prediction intervals are very small, which means that the predicted values are very accurate. The root mean square error and relative maximum error of the models were quite small. Also, the residual signal between the measured value and the estimated value is used to determine the overmeasure due to the fouling phenomena by a sequential probability ratio test which consequently monitors the existing feedwater flow meters.

(B = transition metal) oxides are proved to be highly active catalysts for oxidation reactions in connection with air pollution control. Especially, they are considered as potential catalysts in substitution of noble metal catalysts because of their high thermostability. Many investi-gators have suggested that oxygen vacancies in the perovskite oxides play a major role in catalytic oxidations although there is still debate on the origin of their catalytic activity.

A myriad of research groups have been engaged in searching for novel CB1 receptor antagonists, since SR141716A (rimonabant), a CB1 receptor antagonist, was discovered for an obesity treatment. In this research, extended series, based on the 1,5-diarylpyrazole template of rimonabant, was synthesized and tested for CB1 receptor binding affinity. In the present study, N-piperidinylcarboxamide group of rimonabant was replaced with the corresponding sulfonamide, imide, N-methyl imide and methylenediamide, respectively. The SAR studies to optimize the CB1 binding affinity led to the potent imide derivatives. The in vivo efficacy test of a derivative (16f) gave a promising result for this novel scaffold. In order to explore physicochemical properties (hydrophobic, steric and electronic) of the representative imide derivatives responsible for their CB1 receptor binding affinity, quantitative structure activity relationship (QSAR) studies were performed. Hansch QSAR models, which were moderate in the explanation for SAR, were generated with hydrophobic, steric and electronic properties of substituents. Especially, the Taft Es-based parabolic model was obtained with the best correlation result (r(2)=0.846).

Since the CB1 cannabinoid receptor antagonist 1 (SR141716, rimonabant) was previously reported to modulate food intake, CB1 antagonism has been considered as a new therapeutic target for the treatment of obesity. In the present study, biarylpyrazole analogues based on a pyrazole core coupled with 1,3,4-oxadiazole were synthesized and tested for CB1 receptor binding affinity. Thorough SAR studies to optimize pyrazole substituents as well as 1,3,4-oxadiazole ring led to several novel CB1 antagonists with IC(50) approximately 1 nM for the CB1 receptor binding. Among these analogues, we identified 2-(4-((1H-1,2,4-triazol-1-yl)methyl)-5-(4-bromophenyl)-1-(2,4-dichlorophenyl)-1H-pyrazol-3-yl)-5-(1-(trifluoromethyl)cyclopropyl)-1,3,4-oxadiazole 43c as a promising precandidate for the development as an antiobesity agent.

The oxidative coupling of methane has received a great deal of attention for the last twenty five years because the reaction has been understood as a promising route for the C2-hydrocarbon production from natural gas. To identify suitable catalysts giving high C2-yield, a lot of catalysts have been examined for the oxidative coupling of methane. It has been reported that high surface basicity of a catalyst is necessary to enhance the C2 selectivity in the reaction. Alkali metal oxides and alkaline earth metal oxides are strong bases so that they have catalytic activities for the oxidative coupling of methane. Alkali metal oxides seem to be unsuitable catalysts for the reaction because they form liquid phase of metal hydroxide in the presence of water vapor under reaction conditions, while alkaline earth metal oxides are suitable catalysts because they are easily dehydrated under reaction conditions. When alkali metal ion such as Li or Na is incorporated into MgO or CaO catalyst, its catalytic activity and selectivity for the oxidative coupling of methane can be enhanced. However, the incorporation of alkali ions into CaO or MgO is not quite favorable. CaO itself is so basic that it has good catalytic activity for the oxidative coupling of methane but deactivated due to the formation of carbon solids or carbonate during the reaction. Nevertheless, CaO is still an attractive one in developing the catalyst for the oxidative coupling of methane because it has additional advantages of low cost and widespread availability. Recently, we have examined a series of CaO-based catalysts for the oxidative coupling of methane and have found that CaO fully-coated silica particles showed appreciable selectivity and durability for the oxidative coupling of methane. This paper reports catalytic behaviors and photoluminescence results of the CaO fully-coated silica particles.

The CO2 reforming of CH4 has received increasing attention from both an environmental and an industrial perspective because the reaction can convert greenhouse gases into synthesis gas with a low H2/CO ratio. It has been known that nickel catalyst is highly active for the CO2 reforming of CH4, but it is easily deactivated due to coke formation and metal sintering during the reaction. To develop nickel catalyst resistant to the formation of coke, various materials such as metal oxides, mixed metal oxides, and zeolite have been examined as supports until now. Metal oxide supports are mostly used as fine powder to give large surface area. However, fine powder may be a disadvantage of its application as support because fine particles trend to agglomerate into large particles at high temperatures. In recent, several investigators have shown that mesoporous MCM41 or SBA15 compounds can be applied as catalyst support with high loading and dispersion without destroying the support pore hexagonal structure. SBA15 compounds are more favorable to the application as catalyst support because they have mesopores with sizes of 46-300 A and high surface area of ~800 m/g. Moreover, the recent discovery of ordered large-pore mesoporous SBA15 compound with three dimensional mesoporous networks has extended the applications of mesoporous SBA compound in catalysis and separation because it has the advantage in the diffusion and transport of large molecules compared to one-dimensional mesopore structures. This paper reports the application of mesoporous SBA15 in high temperature catalysis. The SBA15 compound with three-dimensional mesoporous networks was prepared and nickel particles were embedded within the SBA15(3D). The Ni/SBA15(3D) was examined as catalyst for the CO2 reforming of CH4 and its catalytic results were compared with those of Ni/SiO2 and Ni/γ-Al2O3 catalysts.

Amorphous Ni 3 (SbTe 3 ) 2 compound was prepared from a metathesis between Zintl phase K 3 SbTe 3 and NiBr 2 in solution and its oxidation behavior was investigated in the temperature range of 200–700 °C in air. To characterize the sample, thermogravimetry (TG), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis by X-ray (EDAX) analyses were performed and electrical conductivity was measured as a function of temperature in the range of 25–800 °C in air. The specimen showed a metallic conducting-like behavior below 585 °C while a semiconducting-like behavior above 585 °C. At a first oxidation step of Ni 3 (SbTe 3 ) 2 below 500 °C, TeO 2 phase is formed. Above 500 °C, NiO phase is formed, then some NiO reacts with TeO 2 to form NiTeO 3 and NiSb 2 O 6 is simultaneously formed. Above 700 °C, NiTeO 3 is further reacted with TeO 2 to form NiTe 2 O 5 . Both NiTeO 3 and NiTe 2 O 5 are decomposed above 774 °C.

Direct conversion of methane to C2-hydrocarbons via oxidative coupling reaction has received a great deal of attention for the last twenty five years because the reaction has been recognized as a promising route for the production of ethylene from natural gas. However, the process is considered to be economically unfeasible because the yield of ethylene produced in the reaction is less than 25%. In recent, it has been proposed that the disadvantage may be overcome by integrating with processes involving endothermic reactions such as cracking of ethane to ethylene and steam reforming of methane to synthesis gas and the heat of the exothermic coupling reaction can be alternatively used to generate electricity. An interesting potential application of perovskites as catalysts is their use for redox reactions. Lanthanum-transition metal perovskite oxides (LaBO3) are proved to be effective catalysts for the catalytic oxidations of hydrocarbons, CO, and ammonia and considered to be promising materials for application as electrode materials in solid oxide fuel cells. There are few reports on the application of LaBO3 oxides to the catalytic partial oxidation of methane. Tagawa et al. found that the LaAlO3 catalyst prepared by the mist decomposition method is highly active and selective for the oxidative coupling of methane and proposed that an amorphous phase of LaAlO3 is responsible for the catalytic activity. Spinicci et al. found that both catalytic activity and C2-selectivity are largely enhanced when Al ion in the LaAlO3 perovskite is substituted with Li or Mg. In the oxidative methane coupling reaction catalyzed by metal oxide, the transfer of oxygen to the surface from bulk or gas phase is very important on its catalytic activity because the abstraction of a hydrogen from methane is caused by an oxygen ion present on the surface of metal oxide catalyst. LaBO3 perovskite oxides may be suitable catalysts for the methane coupling reaction because they are characterized by high mobility of oxygen ions. Actually, the perovskite oxides have received increasing interest in the mixed-conducting ceramic membrane reactor technology for partial oxidation of methane. In this work, we prepared LaFeO3, LaCoO3, and LaNiO3 perovskite oxides by using a sol-gel method and examined them as catalysts for the oxidative coupling of methane in the temperature range of 650 to 800 C at atmospheric pressure. Experimental Section

Dioxins are a class of polyhalogenated aromatic hydrocarbons that induce a wide spectrum of toxic responses in experimental animals. In this study, 2,3,7,8-tetrachlorobenzo-p-dioxin (TCDD) was exposed to two SD rat groups; one group for short-term exposure at a single dose of 1, 10, 20 and 50 mug/kg body weight (group 1) and the other for long-term exposure at daily and-low dose of 0.01, 0.1, 1 and 2.5 microg/kg body weight (group 2) for a month. Two-dimensional electrophoresis (2-DE) was utilized to resolve the protein profile of rat liver exposed to TCDD at different doses. In the analysis of 2-DE of the group 1, two new-expressed spots and seven volume-increased spots were detected and identified by ESI-Q-TOF MS/MS; especially, proteasome subunit beta type 3 was increased in all doses. In addition, in the group 2, six volume-increased spots were screened; particularly, histidine triad nucleotide binding protein was increased in both 0.1 microg/kg dose and 1 microg/kg dose. The identified proteins were confirmed using Western blot. Among the identified proteins, apolipoprotein A-IV may protect lipid peroxidation and atherosclerosis induced by TCDD exposure and the expression level of phosphoglycerate mutase increases due to hyperthyroidism induced by TCDD exposure.

The catalyzed reaction of carbon dioxide with methane to produce hydrogen and carbon monoxide, CO2 + CH4 → 2CO + 2H2 (∆H=59.1 kcal/mol), has received increasing attention from both an environmental and an industrial perspective. The reaction is attractive because the greenhouse gases (CO2 and CH4) can be converted into a synthesis gas with a low H2/CO ratio, which is suitable for the syntheses of valuable oxygenated chemicals such as aldehydes, methyl alcohol, acetic acid, and dimethyl ether. Ni, Pt, and Ru based catalysts are known to be effective for the CO2-CH4 reaction. One of the major problems is the deactivation of catalysts due to the formation of coke on the catalysts during the reaction. The noble metal based catalysts are less sensitive to coking compared to nickel based catalysts. Nevertheless, it is still worthwhile to develop the nickel-based catalysts resistant to the formation of coke because the noble metals are expensive and of limited availability. The reforming of methane with carbon dioxide over nickel based catalysts has been studied by many investigators. However, there are few reports about fundamental kinetic parameters at present and there are some disagreements on the reaction mechanism including the reaction orders and the activation energy. The catalytic research involves the measurement of reaction rate and the investigation of factors influencing the reaction rate. An accurate description of the reaction rate can be obtained from a rate law which is essential in a reactor design. Although it is difficult to determine the accurate mechanism from an empirical kinetic expression, such empirical kinetic expression may be helpful to understand the catalytic reaction mechanism. The most important consideration in the kinetic experiments is to measure the concentration of reactants or products of interest as a function of time. To measure the concentration, absorption spectroscopy techniques have been generally used. However, their sensitivities may be diminished due to the difficulty in precise measurements of the difference between the incident and the transmitted intensities of radiation. The photoacoustic spectroscopy (PAS) being based on a direct measurement of acoustic waves generated owing to the absorption of optical energy provides highly selective detection and extremely low molecular gas level detection, which enable us to obtain a signal with enough intensity for even time-resolved experiments. Further advantages of this technique can be found in the capability of the elimination of any sophisticated sampling techniques which are inevitable in the conventional techniques. The photoacoustic spectroscopy is thus believed to be a suitable technique for the in situ experiment of a catalytic reaction because it can directly measure the absorption characteristics of the samples of interest. In the previous works, we have shown that the photoacoustic spectroscopy is applicable to the kinetic studies of CO oxidation and water-gas shift reaction over catalysts. In this work, the temporal change in the concentration of CO2 in the catalytic CO2-CH4 reaction was measured in situ as a function of time by using a CO2 laserbased photoacoustic spectroscopy with a suitable difference photoacoustic cell. The measurements were governed at a relatively low reactor pressure so that the technique provided precise kinetic data for the initial reaction stage characterized by high reaction rates. The kinetic data obtained were compared with those of other investigators.

Photoluminescence (PL) and cathodoluminescence (CL) of light emitting diode samples with various InGaN/GaN multi-quantum-well (MQW) active structures and a range of dislocation density (∼7×108/cm2 to ∼9×109/cm2) were investigated. Results indicate that threading dislocations have impact on the luminescence of GaN thin films and act as a nonradiative recombination center. It was also observed that the optical emission is affected by MQW structure such as the number of quantum wells.

Department of Chemistry, Kangnung National University, Kangnung 210-320, KoreaReceived November 4, 2003Key Words : Metal antimony telluride, Partial oxidation of methane The catalytic partial oxidation of methane has received agreat deal of attention for the utilization of natural gas duringthe last 20 years. The degree of CH

Dioxins are a class of polyhalogenated aromatic hydrocarbons that induces a wide spectrum of toxic responses in animals. In this study, two groups of Sprague-Dawley rats were exposed to 2,3,7,8-tetrachlorobenzo-p-dioxin (TCDD); one group received short-term exposure at a single dose of 1, 10, 20 or 50 microg/kg body weight and the other received long-term exposure to a daily low dose of 0.01, 0.1, 1 or 2.5 microg/kg body weight for one month. Two-dimensional electrophoresis was utilized to resolve the protein profile of rat plasma exposed to TCDD at different doses. One novel and three volume-increased spots were identified and characterized by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and electrospray-ionization on quadropole-TOF2 mass spectrometry. The novel protein was identified as plasma glutathione peroxidase precursor and the volume-increased proteins were cytokeratin 8 polypeptide, Ig lambda-1 chain C region and Ig lambda-2 chain C region. These proteins may be used as biomarkers to diagnose dioxin exposure and may help in understanding the toxic effects of dioxins.

temperature range of 100 to 350 o C. The CO2 photoacoustic signal varying with the concentration of CO 2 during the catalytic reaction was recorded as a function of time. The time-resolved photoacoustic spectra obtained for the initial reaction stage provided precise data of CO 2 formation rate. The apparent activation energies determined from the initial rates were 74.7 kJ/mol for the magnetite/chromium oxide catalyst and 50.9 kJ/mol for the copper/zinc oxide catalyst. To determine the reaction orders, partial pressures of CO(g) and H2O(g) in the reaction mixture were varied at a constant total pressure of 40 Torr with N 2 buffer gas. For the magnetite/chromium oxide catalyst, the reaction orders with respect to CO and H 2O were determined to be 0.93 and 0.18, respectively. For the copper/zinc oxide catalyst, the reaction orders with respect to CO and H 2O were determined to be 0.79 and 0, respectively.

Amorphous Ni3(SbTe3)2 was prepared from a metathesis between K3SbTe3 and NiBr2 solution and was examined as a catalyst for the oxidative coupling of methane in a single-pass flow reactor system using on-line gas chromatography at atmospheric pressure. Catalytic reaction was performed by feeding the reaction mixture containing CH4/O2/He in the temperature range of 600–750 °C. Although amorphous Ni3(SbTe3)2 showed no catalytic activity for the oxidative coupling of methane, the O2-pretreated Ni3(SbTe3)2 was found to be active and selective for the reaction. Its C2 selectivities were in the range of 45–79% in the temperature range of 600–750 °C. The best C2-yield was 11% with a selectivity of 79% at 650 °C. X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses were performed for the O2-treated Ni3(SbTe3)2 catalyst before and after the catalytic reaction to characterize the catalyst. Thermogravimetry (TG) analysis was performed for amorphous Ni3(SbTe3)2 in a flow of O2/Ar mixture. Electrical conductivity of amorphous Ni3(SbTe3)2 was measured as a function of temperature in the range of 400–800 °C at both PO2’s of 0.01 and 0.20 atm. The results suggest that NiTeO3 formed on the surface by the O2-pretreatment of catalyst is active and is the selective phase for the oxidative coupling of methane.

A photoacoustic spectroscopic (PAS) technique was applied to the kinetic study of the water–gas shift reaction in the presence of α-Fe2O3 catalyst. The catalytic reaction was performed in the temperature range from 523 to 673 K at various partial pressures of carbon monoxide and water–vapor in a closed-circulation reactor system using a differential photoacoustic cell. The variation of CO2 photoacoustic signal with the concentration of CO2 produced during the reaction was recorded as a function of time. The time-resolved photoacoustic spectra obtained for the early reaction stage provided precise data of CO2 formation rate. The results of CO2 photoacoustic spectra indicated that the catalytic water–gas shift reaction over α-Fe2O3 occurred when α-Fe2O3 was partially reduced to Fe3O4 by heating it in vacuum. The vacuum-pretreated α-Fe2O3 catalyst showed catalytic activity for the water–gas shift reaction and its rate of CO2 formation increased with increasing temperature in this temperature range. The rate of CO2 formation on the vacuum-activated α-Fe2O3 catalyst was highly enhanced when the catalyst was treated in situ with H2O(g) prior to the admittance of CO(g)/H2O(g) reaction mixture. The reaction orders determined from the initial reaction rates of CO2 formation were found to be 0.80 and 0.08 with respect to CO and H2O, respectively. From the experimental results, the active sites and the reaction mechanism for the water–gas shift reaction on the vacuum-activated α-Fe2O3 catalyst could also be discussed.

Nickel nanoparticles in AlMCM41 were prepared by the ion exchange and the reduction with H2 gas. Annealing studies were carried out on Ni–AlMCM41 for the better understanding of the morphology, and magnetic properties of nickel nanoparticles depended on the annealing temperature. Products were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and SQUID measurements. D 2002 Elsevier Science B.V. All rights reserved.

Polypyrroles doped with two dopants were prepared by chemical polymerization in aqueous solutions of pyrrole monomer. The solutions contained dodecylbenzenesulfonic acid (DBSA) as a dopant, tetraethylammonium tetrafluoroborate (TEABF4) as a codopant, and ammonium persulfate (APS) as an oxidant. The PPy composites [polypyrrole-dodecylbenzenesulfonates (PPy-DBS) codoped with tetrafluoroborate (BF)—PPy-DBS-BF] were soluble in m-cresol, NMP, and conditionally soluble in chloroform. Cyclic voltammetry was measured to know the electrochemical property of PPy-DBS-BF. The maximum electrical conductivity of room temperature for PPy-DBS-BF is 1.18 s/cm, which is greatly higher than that of polypyrrole doped with DBS− (0.04 s/cm). The composition and structural characterization of PPy-DBS-BF were inferred from elemental analysis, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. Scanning electron microscopy was performed to know the morphology of PPy-DBS-BF. The results of UV-Vis spectra and electron spin resonance measurements showed that polaron and bipolaron existed as charge carrier of soluble PPy-DBS-BF. From the temperature dependence of the electrical conductivity, it was suggested that possible conduction mechanism for soluble PPy-DBS-BF should be hopping conduction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2583–2590, 2002

The rat primary cultured-airway monolayer has been an excellent model for deciphering the ion channel after nystatin permeabilization of its basolateral or apical membrane. Inwardly rectifying K(+) currents were characterized across the basolateral membrane in symmetrical HCO(-)(3)-free high K(+) Ringer's solution (125 mM) in this study. The potency of K(+) channel inhibitors against K(+) conductance was Ba(2+) (IC(50) = 5 microM) > Cs(+) (IC(50) = 2 mM) >> glybenclamide (IC(50) > 5 mM) >> TEA (IC(50) >> 100 mM). The application of basolateral Cs(+) changed K(+) conductance into an oscillating current, and its frequency (holding voltage = -100 mV) increased with increase in concentration of basolateral Cs(+) (0.05-5 mM) and in degree of hyperpolarization. Addition of basolateral Cs(+) blocked inward current strongly at -100 mV and hardly at all at -60 mV, giving a sharp curvature to the I-V relation of the IRK current. RT-PCR, Western blotting, and immunohistochemical analyses showed that Kir2.1 might be present in basolateral membrane of tracheal epithelia and plasma membrane of pulmonary alveolar cells.

Zintl phase LiSbTe 2 was examined as a catalyst for the oxidative coupling of methane to ethane and ethylene in a single-pass flow reactor system using on-line gas chromatography which operated at atmospheric pressure. Catalytic reactions were performed by feeding the reaction mixture containing CH 4 /O 2 /He or CH 4 /O 2 /H 2 O/He in the temperature range from 873 to 1023 K. LiSbTe 2 catalyst was found to be active and selective for the oxidative coupling of methane only when it was treated under oxygen flow prior to reaction. When the reaction mixture containing CH 4 /O 2 /He was fed over the oxygen-pretreated LiSbTe 2 catalyst, C 2 selectivities were in the range of 40–82%. The best C 2 yield was 12% with a selectivity of 69% at 973 K. When the reaction mixture containing CH 4 /O 2 /H 2 O/He was fed over the oxygen-pretreated LiSbTe 2 catalyst, C 2 selectivities were in the range of 88–91%, in which the best C 2 yield was 13% with a selectivity of 88% at 1023 K. It was found from the effect of contact time on the product distribution that ethane was an initial product and ethylene was a secondary product in the reaction. To characterize the catalyst, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and thermogravimetry analyses were performed for the LiSbTe 2 catalyst. The results suggest that oxygen ions chemisorbed on the surface are responsible for the selective activation of methane.

For newly synthesized ternary Zintl phase LiSbTe 2 , absorption, fluorescence, and excitation spectra indicate that it has an E g of 4.46 eV, and there is an absorption band around 300 nm below the band gap and a Stokes-shifted fluorescence band around 390 nm. At both room temperature and 77 K, power dependent steady-state and time-resolved fluorescence studies result in the appearance of another fluorescence band at about 450 and 520 nm. As the photon power increases, the 390 nm band is blue shifted at the saturation stage with the saturation of the 520 nm band as well. Along with fluorescence lifetime data, the results imply that the 390 and 450 nm bands correspond to shallow trapped exciton state and deep self-trapped exciton state originating from lattice distortion, respectively, and the 520 nm band is from the surface trap state coupled to the frozen solvent environment. The upper limit distance between the trap sites corresponding to 390 nm band is estimated to be about 17.6 nm by the dielectric function calculation of the gas phase model.

The influence of the Ce[sup 3+] concentration on the cathodoluminescence (CL) characteristics of SrAl[sub 12]O[sub 19]:Ce[sub x][sup 3+],EU[sub 0.01][sup 2+] (x = 0.01--0.09) was studied. At 1 mol% cerium in Sral[sub 12]O[sub 19]:Ce[sub x][sup 3+],Eu[sub 0.01][sup 2+] (x = 0.01), two broad emission bands centered at 320 nm and at about 400 nm were observed. The intensity of Ce[sup 3+] emission at 320 nm decreased as the Ce[sup 3+] concentration increased, whereas the intensity of the emission band at 400 nm increased with increasing Ce[sup 3+] concentration at fixed Eu[sup 2+] concentration. At low concentration of Ce[sup 3+] (x = 0.1--0.5), the Ce[sup 3+] emission intensity decreased with the Eu[sup 2+] emission intensity being enhanced due to the energy transfer from Ce[sup 3+] to Eu[sup 2+]. In high concentrations of Ce[sup 3+] (x = 0.07, 0.09), the cross-relaxation processes between nearest Ce[sup 3+] ions led to the diminishing intensity of Ce[sup 3+] emission, because of the limited energy acceptors, i.e., Eu[sup 2+] ions, which resulted in a single emission band at about 400 nm.

ω-Tetrahydropyran-2-ylsulfanylalkylmagnesium chlorides are prepared as Grignard reagents containing protected mercaptoalkyl chains, which are useful for the direct introduction of ω-mercaptoalkyl chains to electrophiles. In order to prove the usefulness of these reagents, they were reacted with buckminsterfullerene (C60) to give 1-(ω-mercaptoalkyl)-1,2-dihydrobuck minsterfullerenes after the deprotection of THP group with TFA.

Altervalent cation-doped neodymium sesquioxide systems such as Ni/Nd 2 O 3 , Mn/Nd 2 O 3 , and Zr/Nd 2 O 3 with various doping mole fractions were prepared and the cation-doping effect on the catalytic activity of neodymium oxide in the oxidative coupling of methane was investigated. The catalytic reaction was carried out in a flow reactor system using on-line gas chromatography. The reaction conditions were 550–800°C, feed mole ratio of CH 4 /O 2 /He=6/1/5, total feed flow rate=30.0 cm 3 min −1 , and 1 atm of pressure. The present catalysts were effective for the oxidative coupling of methane, the selectivity to higher hydrocarbons was increased by doping the cations into Nd 2 O 3 . Among the catalysts tested, 5 mol% Zr-doped Nd 2 O 3 showed the best C n -selectivity ( n ≥2) of 74.1% with a yield of 13.0% at 750°C. Pure Nd 2 O 3 , Ni-doped Nd 2 O 3 , and Mn-doped Nd 2 O 3 catalysts showed no C 3 -hydrocarbon product selectivity, while Zr-doped Nd 2 O 3 catalysts showed C 3 -hydrocarbon product selectivity ranging from 6% to 12%. When the oxygen-pretreated 5 mol% Ni-doped Nd 2 O 3 catalyst was exposed to CH 4 at 400°C, a detectable amount of H 2 was produced, indicating that CH 4 can be selectively activated by oxygen species on the surface. The formation of interstitial oxygen ions through the reaction of oxygen with the oxide is a controlling factor for the catalytic activity of the oxide in the oxidative coupling of methane. The oxygen vacancy formed by doping divalent cation into Nd 2 O 3 exerts influence on the formation of active oxygen ion. Zr 4+ -doping can also increase the concentration of active oxygen ion in the oxide. Defects and active sites in the catalyst are discussed on the basic of solid-state chemistry.

Perovskite-type Nd1-xSrxCoO3-y catalysts with various Sr mole fraction were prepared and investigated for the effect of Sr substitution on their catalytic activities in the oxidation of carbon monoxide. Utilizing the static and flow methods, kinetic studies have been carried out between 373 and 523 K. The initial reaction was investigated by the static reactor system using a differential photoacoustic cell, and for the study of reaction stage showing a constant catalytic activity after an initial stage characterized by high reaction rates, the flow reactor system using on-line gas chromatography was employed. The catalytic activity increased with increasing amounts of Sr substitution for Nd in NdCoO3 compounds, and it also increased with higher reaction temperature within the range of 373-523 K. Kinetic data obtained in an initial reaction stage by CO2 photoacoustic spectroscopy showed that the reaction partial orders to CO and O2 were 0.8-0.9 and 0, respectively. In the reaction stage showing a constant catalytic activity after an initial stage, the oxidation was found to be first order with respect to CO and 0.5 order with respect to O2. The concentration of oxygen vacancy in the solid catalyst was shown to be the controlling factor for the oxidation of carbon monoxide. According to the experimental results, the mechanisms of the CO oxidation processes are discussed, and it is believed that O2 adsorbs on the oxygen vacancies (Vo x ) formed by Sr substitution while CO adsorbs on the lattice oxygens during the reaction process.

The recent discovery of uniform mesoporous SBA15 (Santa Barbara amorphous) consisting of long-range channels offers new possibilities in a previously inaccessible size range by inclusion chemistry. SBA15 is an all silica mesoporous molecular sieve possessing one-dimensional hexagonal channels with 6 nm pore diameter. In this work we report on technology and magnetic properties of γ-Fe 2 O 3 nanoparticles entrapped inside SBA15 channels. They have homogeneous distribution throughout the SBA15 and larger particles at the external surface are absent. Both DC magnetization measurements and transmission electron microscopy show a good controlled insertion of γ-Fe 2 O 3 into the host channel.

The amorphous ternary material, Ni3(SbTe3)2 was prepared using a rapid precipitation reaction between the Zintl phase K3SbTe3 and NiBr2 in solution. This material induced by the incorporation of ternary chalcogenide into long range ordered mesoporous SBA-15 was transformed into ternary nanoparticles. Structural confinement of the amorphous ternary chalcogenide in the mesoporous silica tube causes the suppression of phonon coupling to photoexcited carriers in the confined ternary chalcogenide, resulting in narrower photoluminescence (PL) band than those of the bulk ternary chalcogenide. It also gives rise to ferromagnetic behavior of the nanoparticles made from the material, which is a spin glass with the freezing temperature of 4.0 K in a bulk form. The physical and chemical properties of obtained ternary bulk and nanoparticles have been investigated by x-ray diffraction, superconducting quantum interference device, transmission electron microscopy, Brunauer–Emmett–Teller, and PL (steady-state photolumine...

Background: Since the cannabinoid receptor 1 (CB1) antagonist SR141716 (rimonabant) was previously reported to modulate food intake, CB1 antagonism has been considered as a new therapeutic target for the treatment of obesity. Discussion: In the present study, biarylpyrazole analogues based on a sulfur-containing pyrazole core coupled with 1,3,4-oxadiazole and 1,3,4-thiadiazole were synthesized and assayed for rat CB1 receptor binding affinity. Results: The structure–activity relationship studies to optimize pyrazole substituents as well as 1,3,4-oxadiazole or 1,3,4-thiadiazole rings led to four novel CB1 antagonists with IC50 values of approximately 1 nM for the rat CB1 receptor binding. Among these derivatives, we identified trifluoromethylcyclobutyl analogues 19e and 19l as promising precandidates for the development as anti-obesity agents.

Novel C-aryl glucoside SGLT2 inhibitors containing the thiazole motif were designed and synthesized for biological evaluation. Among the compounds assayed, thiazole containing furanyl moiety 14v and thiophenyl moiety 14y demonstrated the best in vitro inhibitory activity against SGLT2 in this series to date (IC50 = 0.720 nM for 14v and IC50 = 0.772 nM for 14y). Both of these compounds have been further evaluated on a urinary glucose excretion test and the urine volumes excreted.

In order to investigate SAR regarding glucose moiety in novel C-aryl glucoside SGLT2 inhibitors containing a thiazole motif, a series of chemical modifications on glucose was conducted to explore potential utility as a suitable replacement of glucose per se. Among the compounds prepared, deshydroxy 29 (IC50 = 7.01 nM) demonstrated the best in vitro inhibitory activity against SGLT2 in this series to date. But, none of the compounds were better than the parent molecule 5 (IC50 = 1.75 nM).