Analysis of imazalil and its major metabolite in citrus fruits by GC-FTD

A simplified simultaneous analytical method of imazalil (IZ) and its major metabolite, alpha-(2,4-dichlorophenyl)-1H-imidazole-1-ethanol (IZM), in citrus fruits was developed, and commodities samples were investigated. A homogenate of citrus fruits was extracted with ethyl acetate under basic conditions. The crude extract was partitioned between 0.025 mol/L of sulfuric acid and ethyl acetate. The analytes were extracted from the aqueous fraction under basic conditions with ethyl acetate. The extract solution was purified with an ENVI-Carb cartridge, and then analyzed by GC-FTD and GC/MS. Recoveries of IZ and IZM added to grapefruit at the level of 0.05 microgram/g were 90.0 and 108.7%, and those in the case of lemon were 100.4 and 93.0%, respectively. The detection limits were 0.01 microgram/g in samples. By this method, IZ and IZM were analyzed in 46 citrus fruits on the market and were detected simultaneously in some samples.     

Transferred arc plasma processed mullite from coal ash and bauxite

Coal ash disposal is one of the main problems in thermal power plant unit. Currently, a number of waste management systems are being tried for effective disposal of coal ash. In this paper, coal ash from thermal power plant unit was successfully utilized for synthesis of mullite ceramic by using transferred arc plasma processing (TAP) technique. For this purpose, bauxite was added with coal ash by 0, 25, 50 and75 weight ratio. The compositions were thoroughly mixed by ball milling and were melted in the transferred arc plasma torch at 10 kW input power level for 3 min. Argon was used as plasma forming gas. The phase and microstructure formation of the melted samples were investigated by XRD and SEM images. The results show that the additions of bauxite greatly influenced the phase formation of mullite during the processes.     

新型吸附床的研究进展

吸附床是吸附式制冷装置的核心部件,其性能的优劣直接关系到吸附式制冷装置的制冷效果.通过吸附床的热阻分析,得出强化吸附床传热的措施.文中重点介绍了提高吸附剂与换热壁面的换热系数和吸附剂间的导热系数来强化吸附床传热的方法,详细介绍了填充式吸附床、涂抹式吸附床以及固化式吸附床的结构特点,比较分析3种吸附床的传热传质特点,并阐...     

Preparation of TiO2 thin films using octadecylamine Langmuir-Blodgett films and evaluation of their photocatalytic activity

A study was conducted to demonstrate that nanometer-thick titanium dioxide (TiO(2)) thin films could be prepared by the hydrolysis of titanium potassium oxalate using octadecylamine (ODA) Langmuir-Blodgett (LB) films as templates. The amount of TiO(2) generated in the LB film was found to be proportional to the number of deposited ODA layers, which enables precise control of the TiO(2) film thickness. After heat treatment of the LB films at 300-600°C, the photocatalytic activities of the resulting TiO(2) films were determined from the decomposition of stearic acid cast films when irradiated with UV light for different time periods. Higher photocatalytic activity was observed in TiO(2) films heat treated at lower temperatures.     

Antiproliferative effect of aaptamine on human chronic myeloid leukemia k562 cells

We previously isolated aaptamine, a benzonaphthyridine alkaloid, from marine sponge Aaptos suberitoids. In this study, we investigated the anti-proliferative effect of aaptamine on chronic myeloid leukemia (CML) K562 cells. Aaptamine inhibited growth of K562 with a GI50 as 10 μM, and arrested cell cycle at G2/M phase. Western blot analysis indicated that aaptamine induced p21 expression in K562 cells. Moreover, p21 promoter was activated by aaptamine treatment in p21 transfected K562 cells. Since K562 is p53 negative, aaptamine was demonstrated to be a p53-independent p21 inducer in CML cells.     

Glass capillary optics for producing nanometer sized beams and its applications

We have developed a method to produce micro/nano meter sized beams of keV energy highly charged ions (HCIs) and MeV energy protons/He ions with tapered glass capillary optics for application of surface modifications and a biological tool called “cell surgery”, respectively. The transmission through the tapered glass capillaries with inlet diameter of 0.8 mm?, outlet diameter from 900 nm? to several tens of microns and length of about 50 mm was performed using 8/64 keV Ar⁸⁺ beams. The transmitted beams had a density enhancement of about 10 and were guided through a capillary tilted by as large as ±100 mrad. The charge state of the beams was kept during the transmission. The combination of MeV proton/He ion beams and the capillary with a thin end window at its outlet can realize pinpoint energy deposition and three-dimensional selection of the bombarding point in an arbitrary position of a living cell or in any liquid object. We demonstrated that a real biological cell, HeLa cell with the nucleus labeled by green fluorescent protein (GFP), was irradiated with the microbeam, which was prepared by 4 MeV He²⁺ entering a capillary with an end window of 7.3 μm in thickness and outlet diameter of 9.6 μm?. The transmitted MeV ion beams had density enhancement up to 1000 according to the capillary outlet sizes, which are applicable to various material analyses employing microbeams.     

Changes in the melting temperature and crystal structure of poly(vinylidene fluoride) by knotting

A significant increase in the melting temperature of knotted fibers of poly(vinylidene fluoride) (PVDF) was detected by differential scanning calorimetry. The melting peak partially returned to the original peak after the fibers were unknotted. Knotted PVDF fibers were observed with an optical microscope at crossed‐nicol conditions. The knotted portions of the fibers showed birefringence even above the melting temperature of the fibers before knotting. The dependence of the physical properties of PVDF under applied stress was estimated in order to investigate the influence of knotting. The fracture temperature of PVDF fibers increased with applied stress below 1 MPa and decreased above 10 MPa because the applied stress increased the melting temperature of PVDF crystals, but strong stress mechanically broke the fibers. The X‐ray diffraction patterns of the PVDF fibers under different stress were divided into the peaks of α‐ and β‐phase crystals and amorphous. The peak area of the β‐phase crystal increased and that of the amorphous decreased with applied stress. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Increased Lipid Synthesis and Decreased β-Oxidation in the Liver of SHR/NDmcr-cp (cp/cp) Rats, an Animal Model of Metabolic Syndrome

SHR/NDmcr-cp (cp/cp) rats (SHR/NDcp) are an animal model of metabolic syndrome. A previous study of ours revealed drastic increases in the mass of palmitic (16:0), oleic (18:1n-9), palmitoleic (16:1n-7), cis-vaccenic (18:1n-7) and 5,8,11-eicosatrienoic acids in the liver of SHR/NDcp. However, detailed information on the class of lipid accumulated and the mechanism responsible for the overproduction of the accumulated lipid in the liver was not obtained. This study aimed to characterize the class of lipid accumulated and to explore the mechanism underlying the lipid accumulation in the liver of SHR/NDcp, in comparison with SHR/NDmcr-cp (+/+) (lean hypertensive littermates of SHR/NDcp) and Wistar Kyoto rats. In the liver of SHR/NDcp, de novo synthesis of fatty acids (16:0, 18:1n-9 and 16:1n-7) and triacylglycerol (TAG) synthesis were up-regulated and fatty acid β-oxidation was down-regulated. These perturbations of lipid metabolism caused fat accumulation in hepatocytes and accumulation of TAG, which were enriched with 16:0, 18:1n-9 and 16:1n-7, in the liver of SHR/NDcp. On the other hand, no changes were found in hepatic contents of diacylglycerol and unesterified fatty acid (FFA); among FFA, there were no differences in the hepatic concentrations of unesterified 16:0 and stearic acid between SHR/NDcp and two other groups of rats. Moreover, little change was brought about in the expression of genes responsive to endoplasmic reticulum stress in the liver of SHR/NDcp. These results may reinforce the pathophysiological role of stearoyl-CoA desaturase 1 and fatty acid elongase 6 in the liver of SHR/NDcp.