Degradation of Leather Dye Using CeO2–SnO2 Nanocomposite as Photocatalyst Under Sunlight

Nanocomposite of CeO₂?CSnO₂ containing different CeO₂ contents was prepared by coprecipitation process. The material obtained was characterized by X-ray diffraction and N₂ adsorption?Cdesorption isotherms. Its photocatalytic activity was tested in the degradation of azo dye of leather, Direct Black 38, in aqueous solution under sunlight. The photocatalytic activity of the coupled CeO₂?CSnO₂ oxide ranged depending on the CeO₂ contents. The optimum amount of CeO₂ for the synthesis of CeO₂?CSnO₂ was 7?wt.% since the nanoparticles showed high photocatalytic activity in the degradation of the dye, similar to that of the TiO₂?CP25 photocatalyst. The kinetics of photocatalytic degradation and total organic carbon removal under sunlight were found to follow a first-order rate law. The results indicated that CeO₂?CSnO₂ can be used for the removal of dyes from wastewater.     

Preparation of Highly Efficient CoFe<Subscript>2</Subscript>O<Subscript>4</Subscript>/Zn<Subscript>2</Subscript>SnO<Subscript>4</Subscript> Composite Photocatalyst for the Degradation of Rhodamine B Dye from Aqueous Solution

CoFe₂O₄/Zn₂SnO₄ composite was synthesized using a simple two-step process and applied as a novel-efficient photocatalyst for the rhodamine B degradation from aqueous solution. Characterization techniques such as X-ray diffraction (XRD), N₂ adsorption-desorption isotherms, scanning electron microscopy (SEM), EDS analysis, and diffuse reflectance spectroscopy were employed in order to investigate the physical and chemical properties of composite. Higher values of the specific surface area, pore volume and diameter, and a smaller band-gap energy promoted a greater catalytic activity of CoFe₂O₄/Zn₂SnO₄ composite when compared to Zn₂SnO₄. A rapid decolorization of dye solution was observed at 40 min of reaction using the CoFe₂O₄/Zn₂SnO₄ catalyst, being 2.5 times faster than the Zn₂SnO₄ alone. Therefore, the CoFe₂O₄/Zn₂SnO₄ composite shows extraordinarily high photocatalytic activity toward the degradation of rhodamine B dye from aqueous solution.     

Analysis of alternariol and alternariol monomethyl ether on flavedo and albedo tissues of tangerines (Citrus reticulata) with symptoms of alternaria brown spot

A method was developed for the quantification of alternariol and alternariol monomethyl ether on tangerines with and without symptoms of Alternaria brown spot disease. The method employs solid-phase extraction for cleanup, followed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) for detection. This method was validated on flavedo (exocarp or epicarp, exterior yellow peel) and on albedo tissue (mesocarp, interior white peel). An excellent linearity over a range of 0.50-20.0 mg/kg was achieved, with r2 >or= 0.997. The limits of detection (LOD) and quantification (LOQ) were fewer than 0.13 and 0.50 microg/kg, respectively. The relative standard deviations (RSDs) were 相似文献   

Antiallergic tea catechin, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate,suppresses FcepsilonRI expression in human basophilic KU812 cells

We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG' '3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcepsilonRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG' '3Me, the effect of EGCG' '3Me on the cell surface expression of FcepsilonRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG' '3Me was able to decrease the cell surface expression of FcepsilonRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcepsilonRI alpha chain decreased upon treatment with EGCG' '3Me. FcepsilonRI is a tetrameric structure comprising one alpha chain, one beta chain, and two gamma chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG' '3Me reduced FcepsilonRI alpha and gamma mRNA levels. The cross-linkage of FcepsilonRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG' '3Me treatment inhibited the FcepsilonRI cross-linking-induced histamine release. These results suggested that EGCG' '3Me can negatively regulate basophil activation through the suppression of FcepsilonRI expression.     

Photocatalytic Efficiency of TiO<Subscript>2</Subscript> Supported on Raw Red Clay Disks to Discolour Reactive Red 141

In this work, disks containing different amount of the TiO₂ precursor impregnated on the raw red clay were produced. The disks were obtained by pressing in metal template and subsequently calcined at 500 °C. The raw clay was used as rigid support to fix the TiO₂. The materials were characterized by X-ray diffraction, diffuse reflectance spectroscopy, N₂ adsorption-desorption (BET and BJH), scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The ability of disks to produce superoxide and hydroxyl radicals after photoexcitation with UV irradiation was monitored by EPR. The catalytic efficiency was evaluated by the Reactive Red 141 dye discoloration under artificial UV light and sunlight. The reaction parameters such as concentration of RR-141 and irradiation source were evaluated. The results showed that the disks were able to decolorize 97.5% under sunlight at 60 min. The disks were also efficient in the discoloration until the tenth cycle, resulting in discoloration values near the initial cycles. Additionally, the dye fragments produced in cleavage of molecule during the reaction were evaluated by LC/MS-MS.

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Radiocesium transfer from Andosols to brown rice in the northern and northwest areas of Tochigi Prefecture,in the first 3 years following the 2011 Fukushima Daiichi nuclear power plant accident

ABSTRACT

Following the Fukushima Daiichi Nuclear Power Plant accident of 2011, the potential for radiocesium transfer from contaminated soils, such as Andosols, to agricultural crops became a significant concern. Andosols account for up to 70％ of paddy soils in the northern and northwest areas of Tochigi Prefecture, where the radiocesium concentration is 1000 Bq kg^?1 or greater in the soil of some fields. The present study was carried out in order to determine the phytoavailability of radiocesium in Andosols by comparing it with that of gray lowland soils in the first 3 years following the accident. The transfer factor (TF) tended to be higher in Andosols than in gray lowland soils, leading to higher radiocesium concentrations in brown rice grown in Andosols. The exchangeable potassium (Ex-K₂O) in Andosols was highly and negatively correlated with TF, followed by clay. The Ex-K₂O value was positively correlated with the clay/total carbon (T-C) value, suggesting that a high T–C ratio could weaken K₂O adsorption on clay mineral sites; hence, the low clay/T-C values can partially explain the relatively large TF values of Andosols. Samples with Ex-K₂O contents less than 200 mg kg^?1 and with low clay/T-C values showed striking decreases in TF values from 2011 to 2012. However, the decrease from 2012 to 2013 was quite small; radiocesium in these samples was potentially available for rice uptake for a long time, likely due to the reversible adsorption and fixation characteristics of allophane. Most gray lowland soil samples showed very low TF values over the 3 years of the study, except for those with TF values greater than 0.1 due to low Ex-K₂O and clay contents; the geometric mean (GM) value of TF was below 0.01 in 2012. The extraction of exchangeable radiocesium (Ex-Cs) with a 1 mol L^?1 ammonium acetate solution may not be an appropriate method for explaining the variability in radiocesium TF in Andosols. This is because the Ex-Cs value was significantly correlated with Ex-K₂O in Andosols, but not in gray lowland soils, indicating that Ex-K₂O explained this variability in relation to Ex-Cs.     

Tracking Anthropogenic Inputs in Barigui River, Brazil Using Biomarkers

The Barigüi River watershed is located in the metropolitan region of Curitiba, Southern Brazil, passing through several neighboring counties. In recent years, due to growth and disorderly occupation along the river, in addition to lack of sanitation, the Barigüi River suffered a very large inflow of untreated domestic wastewater. Current programs to monitor the watershed use traditional physical–chemical parameters. Here, the presence of some molecular tracers found in domestic effluents was investigated, such as caffeine and coprostanol at some selected sites in Barigüi River. Caffeine is highly soluble in water and its presence in water bodies is due to the disposal of untreated sewage. Caffeine is eliminated in the urine (approximately 0.5% to 10% of the consumption). The samples were collected in three campaigns, two in dry weather and another during a week in the rainy season. The results showed that caffeine concentration ranged between zero and 753.5 μg g^?1. Higher values were found on rainy days. Caffeine showed a positive correlation between BOD and nitrate; it also showed a positive correlation with coprostanol, a fecal biomarker. Finally, caffeine has been shown to be a good parameter to determine the contamination by domestic wastewater.     

Interdigital involvement in a case of primary cutaneous canine histoplasmosis in Japan

A 5-year-old male Siberian husky bred outdoor in Tokyo had a swollen paw with interdigital granulomatous lesions in the left hindlimb. The dog had no apparent pulmonary or gastrointestinal involvement. Histopathological analysis of the skin lesions demonstrated yeast-like organisms predominantly within macrophages. Sequence analysis of fungal ribosome RNA gene isolated from a paraffin sample revealed a 100% homology with the teleomorph of Histoplasma capsulatum. The present case may support the concept of primary cutaneous canine histoplasmosis as an endemic phenotype recognized in Japan.     

Vulnerability of feline T-lymphocytes to charged particles

An analysis of ionizing radiation-induced damage in peripheral lymphocytes has been employed to predict the prognosis of radiotherapy in terms of toxicity in normal tissues. Therefore, understanding the sensitivity of lymphocytes to high linear energy transfer (LET)-charged particles would be indispensable for utilizing charged particle therapy in veterinary medicine. However, the availability of such information is very limited. This study aimed to compare the radiosensitivity of feline T lymphocytes to gamma-rays (0.2 keV/microm) and 4 different types of charged particles with LET values ranging from 2.8 to 114 keV/microm. It was observed that the relative biological effectiveness, inactivation cross-section, and isodose-induced apoptosis increased in an LET-dependent manner. On the other hand, no difference in apoptosis frequency was observed in the cells exposed to an isosurvival dose of all the radiation types tested. This is the first study that demonstrates the LET dependence of cell killing and apoptosis induction in feline T lymphocytes. Our results suggest that lymphocytes can be effectively used to predict the prognosis of charged-particle therapy in cat patients.     

Identification of the strong vasorelaxing substance scirpusin B, a dimer of piceatannol, from passion fruit (Passiflora edulis) seeds

Piceatannol is present in passion fruit (Passiflora edulis) seeds in high amounts. In this study, we isolated the second major polyphenolic compound of passion fruit seeds and identified it as scirpusin B, which is a dimer of piceatannol. We investigated the antioxidant activities and vasorelaxing effects of these polyphenols. Their antioxidant effects were measured using an in vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and their vasorelaxant effects were determined ex vivo in rat thoracic aorta. Both polyphenolic compounds exhibited potent antioxidant activities and significant vasorelaxant effects in endothelium-intact aortas. More specifically, scirpusin B exerted a greater antioxidant activity and vasorelaxant effect compared with that of piceatannol. Additionally, the vasorelaxation effects of the compounds were induced via the NO derived from the endothelium. This study provides the possibility that polyphenols in passion fruit seeds are effective against cardiovascular diseases (CVDs).