Immunolocalization of multiple membrane proteins on a carbon replica with STEM and EDX

We present a method for immunolabeling of multiple species of membrane proteins with high spatial resolution. It allows differentiation of equally sized very small markers with different chemical compositions, which leads to high labeling efficiency and reduces steric hindrance of closely spaced immunolabeled biomolecules. Markers such as CdSe/ZnS semiconductor quantum dots and colloidal gold particles are distinguished by differential contrast in high-angle annular detector dark-field STEM mode or by EDX microanalysis of their elemental contents. This method was tested by observation of labeled AMPA- and NMDA-type glutamate receptors on sodium-dodecyl-sulfate-digested replica prepared from rat hippocampus. To improve particle visibility and detectability, the replica films were made exclusively with carbon to avoid the high background of conventional platinum/carbon replica. Extension of the method is suggested by detection of 1.4 nm nanogold particles and its potential application in the biological imaging research.     

Dechlorination of chlorobenzene compounds on flyash; effects of metals, aqueous/organic solvents and temperatures

Dechlorination of chlorobenzene compounds on flyash by using a solution of calcium hydroxide and sulfur in aqueous/organic solvent at 60–170 °C, under oxygen deficient conditions was studied. High percentage of dechlorination was obtained under certain reaction conditions. The results suggested that at 90 °C, metals in general and copper and lead in particular enhanced the catalytic potential of flyash for dechlorination by hydrodechlorination and substitution reactions. But at high temperatures (120–170 °C), dechlorination process was adversely affected by these metals. The effects of water, organic solvents, temperatures and heating time, were studied and reactions conditions were optimized to get maximum dechlorination.     

Investigation of ochratoxin a, B and citrinin contamination in various commercial foods

Ochratoxin A (OTA), ochratoxin B (OTB) and citrinin (CIT) in commercial foods were simultaneously determined and confirmed with high-performance liquid chromatography (HPLC) and liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). The samples examined were made up of cereal, fruit, coffee, and cacao products. The limits of quantification (S/N> or =10) of OTA, OTB and CIT were 0.1 microg/kg or less. Aflatoxins (AF), deoxynivalenol (DON) and fumonisins were also surveyed. Of 157 samples examined, 44 were contaminated with OTA at levels of 0.11 to 4.0 microg/kg. At least 2 positive samples were labeled as domestics. In most positive samples, the OTA level was low, less than 1 microg/kg. The highest incidence of OTA was observed in cacao powder (10/12), followed by instant coffee (5/7), cocoa (5/8) and raisin (6/13). OTB was found in fruit and cacao products containing relatively high levels of OTA. Co-occurrence of OTA, CIT and DON was found in cereal products, and co-occurrence of OTA and AF was found in cacao products. Approximately 30% of naturally contaminated OTA in roasted coffee bean moved into the extract solution when brewed with paper filter.     

Simultaneous determination of ochratoxin A, B and citrinin in foods by HPLC-FL and LC/MS/MS

Methods using high-performance liquid chromatography with fluorescence detection (HPLC-FL) and using liquid chromatography with tandem mass spectrometry (LC/MS/MS) were developed for simultaneous determination of ochratoxin A (OTA), ochratoxin B (OTB) and citrinin (CIT) in cereal, fruit, and coffee products. The samples were extracted with ethyl acetate under an acidic condition, and then cleaned up with liquid-liquid separation. The test solutions were analyzed by reverse-phase HPLC-FL and LC/MS/MS. Mass spectral acquisition was performed in positive ion mode by applying multiple reaction monitoring. The performances of both detectors were almost equivalent. The recoveries of OTA and OTB were 87-111%, and that of CIT were 70-88%. The limits of quantification (S/N> or =10) of OTA, OTB and CIT was 0.1 mug/kg or less. These methods were considered to be useful for the determination of the three mycotoxins at low levels (0.1 microg/kg).     

Genetic Basis Underlying Structural Shift of Monoterpenoid Pheromones in Mealybugs

Journal of Chemical Ecology - Insect sex pheromones are examples of semiochemicals that trigger the most conspicuous biological activities, and they have attracted the interest of chemical...     

Angiosarcoma of the tongue: report of a case with immunohistochemical findings

Angiosarcomas are rare, accounting for only 1-2% of all soft tissue sarcomas. Primary abdominal angiosarcomas usually arise in the liver or spleen. We report the first color Doppler findings of a rare, low-grade splenic angiosarcoma in a 52-year-old woman.     

System preservation of a cooperative manipulator system

This paper proposes a method of maintaining the stability of robotic manipulators with network connection which are doing cooperative tasks. Such robotic manipulator systems have many possibilities, but they sometimes fall into unstable states due to double connection, that is, mechanical and informational connection. To avoid such unstable oscillations, the proposed method utilizes a kind of torque limiter and a notch filter. © 1997 Scripta Technica, Inc Electr Eng Jpn, 121(2): 47–53, 1997