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The decomposition of natural gas over Pd-NiO/Al[sub 2]O[sub 3] and Pt-Sn/Al[sub 2]O[sub 3] is carried out in a microwave catalytic reaction at room temperature. The decomposition of methane is caused by collision by excitation of unstable electronic state. Measuring the flow rate and plasma power can provide kinetic data and indicate the mechanism. The conversion of C[sub 2] products increases from 47 to 63.7% in the microwave plasma catalytic reaction with electric field. Comparing the activities of catalysts, Pd-NiO/Al[sub 2]O[sub 3] bimetallic catalyst is more active than Pt-Sn/Al[sub 2]O[sub 3] catalyst because of modification of the surface of catalysts by carbon formation. The kinetic modeling of plasma of methane conversion seems related to the power of the electric discharge. It was also revealed that proper coking or polymeric carbon formation improves the catalytic activity; therefore, the conversion of methane may increase over Pd-Ni/Al[sub 2]O[sub 3] catalyst in the plasma system. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mn3O4 nanoparticles were immobilized at the surface of polystyrene particles using surfactant. [•] Surface coverage of PS particles with Mn3O4 was controlled by varying the concentration of manganese salt in reaction medium. [•] Extent of surface coverage of PS by Mn3O4 increased with more amount of manganese salt. [•] The composites having the largest surface area showed the highest catalytic efficiency for degradation of methylene blue. [ABSTRACT FROM AUTHOR]

Background/aims: Anisakiasis is a well known parasitosis resulted from eating raw seafoods and there were many reports of cases. However, its endoscopic and clinical characteristics have not been reviewed well. The aim of this study was to clarify the gastric mucosal changes and influencing factors of upper gastrointestinal (UGI) anisakiasis., Methods: We analyzed retrospectively the endoscopic and clinical characteristics of 141 cases with UGI anisakiasis diagnosed during UGI endoscopy, based on the review of medical records. The patients' data were collected consecutively from October 1999 through September 2006., Results: In the 141 patients with UGI anisakiasis, the peak age was the 40s (44.7%). The female to male ratio was 1.82:1. The most prevailed season was winter (41.1%). The most frequent symptom was acute epigastric pain and 76.6% of the patients developed symptoms within 12 hours after the ingestion of raw seafoods. The greater curvature of body was the most preferred site of anisakid larvae. The median time from meal to symptom onset was shortest in esophageal location and longest in fundus location (3 vs. 18.7 hours). The various mucosal changes were observed and the most frequent mucosal change was edema (90.8%). Submucosal tumor was also found in 31.9% of the patients. The severity of mucosal change was related inversely with the time interval from meal to endoscopy (p=0.048)., Conclusions: Anisakiasis presented various mucosal changes depending on the time interval from ingestion of raw seafood to endoscopy. Delayed endoscopy may lead chronic mucosal change and cause difficulty in the detection of anisakiasis. Therefore, the prompt endoscopic examination is required for the patients presenting acute gastrointestinal symptoms after taking raw fish.

The successful one-step preparation method of monodisperse hybrid silica particles was studied using organosilane chemicals in aqueous solution. In general, almost all of the hybrid silica materials were made by a complex method where organic materials were coated on the surface of silica substrate via chemical reaction. However, our novel method can be applied to prepare colloidal hybrid particles without using substrate material. This method has three advantages: (i) this simple method gives the opportunity to prepare hybrid particles with high monodispersity through the self-hydrolysis of various organosilane monomers in aqueous solution, (ii) this efficient method can be applied to load lots of organic functional groups on the surface of silica particles through a one-step preparation method using only organosilane, and (iii) this effective method can be used to control the particle size of the product by changing the experimental conditions such as the concentration of the precursor or the reaction temperature. Detailed characterization of the hybrid particles by scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis (TGA) was performed to elucidate the morphologies and properties of the hybrid silica particles.

The growth of pine trees has diminished in recent years in industrial areas of Korea. Soil acidification is believed to be responsible. To study its effects, we grew seedlings of three-year-old Korean pine in brown forest soil derived from granite, which had been treated with an acid solution, for 182 days. The anion mol ratio in the solution was SO4(2-):NO3-:Cl-=5:3:2, which is the average in the total precipitation in Korea; six H+ ion concentrations in the soil were studied (0 (control), 10, 30, 60 and 90 mmol H+.kg-1). With increasing amounts of H+ added to the soil, the concentrations of Ca, Mg, K, Al and Mn increased, especially below a soil pH of 3.8. The concentrations of Ca, Mg and K in pine needles and stems increased with increasing H+ added to the soil, whereas their concentrations in the root decreased. Conversely, the concentration of N and P in each organ of the pine plant was higher in all treatments than in controls. Also, the concentrations of Al and Mn increased significantly in all organs of the plant with increasing H+. We also estimated the effect of deliberate soil acidification on tree growth, using the molar ratio (Ca+Mg+K)/Al as an indicator of soil acidification. A strong positive correlation was found between the total dry mass (TDM) of seedlings and the (Ca+Mg+K)/Al molar ratio calculated from the concentrations of water-soluble elements in soil (r=0.99, p<0.001). When the (Ca+Mg+K)/Al molar ratio reached 1.0, the relative TDM had fallen to 40%. These results show that deliberate soil acidification reduces the growth of the Korean pine less than it does the Red pine, which has been the dominant species in Korea.