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11.
The occurrence of oocytes in the testis (testis-ova) of several fish species is often associated with exposure of estrogenic chemicals. However, induction mechanisms of the testis-ova remain to be elucidated. To develop marker genes for detecting testis-ova in the testis, adult male medaka were exposed to nominal concentration of 100 ng L−1 of 17α-ethinylestradiol (EE2) for 3-5 weeks, and 800 ng estradiol benzoate (EB) for 3 weeks (experiment I), and a measured concentration of 20 ng L−1 EE2 for 1-6 weeks (experiment II). Histological analysis was performed for the testis, and microarray analyses were performed for the testis, liver and brain. Microarray analysis in the estrogen-exposed medaka liver showed vitellogenin and choriogenin as estrogen responsive genes. Testis-ova were induced in the testis after 4 weeks of exposure to 100 ng L−1 EE2, 3 weeks of exposure to 800 ng EB, and 6 weeks of exposure to 20 ng L−1 EE2. Microarray analysis of estrogen-exposed testes revealed up-regulation of genes related to zona pellucida (ZP) and the oocytes marker gene, 42Sp50. Using quantitative RT-PCR we confirmed that Zpc5 gene can be used as a marker for the detection of testis-ova in male medaka.  相似文献   
12.
Vegetation samples from King George Island, Antarctica (62°05'S, 058°23'W) were collected in the austral summer of 2004-2005. Lichens (Usnea aurantiaco-atra and Usnea antarctica), mosses (Sanionia uncinata, Syntrichia princeps and Brachytecium sp.), and one angiosperm (Colobanthus quitensis) species were analyzed for persistent organic pollutants as well as δ(13)C and δ(15)N stable isotopes. The following contaminants were found above the method detection limit (MDL): HCB (0.141-1.06 ng g(-1) dry weight), HCHs (相似文献   
13.
Solid adsorbent materials, prepared from waste cement powder and concrete sludge were assessed for removal of arsenic in the form of arsenic (As(V)) from water. All the materials exhibited arsenic removal capacity when added to distilled water containing 10–700 mg/L arsenic. The arsenic removal isotherms were expressed by the Langmuir type equations, and the highest removal capacity was observed for the adsorbent prepared from concrete sludge with heat treatment at 105 °C, the maximum removal capacity being 175 mg-As(V)/g. Based on changes in arsenic and calcium ion concentrations, and solution pH, the removal mechanism for arsenic was considered to involve the precipitation of calcium arsenate, Ca3(AsO4)2. The enhanced removal of arsenic for the adsorbent prepared from concrete sludge with heat treatment was thought to reflect ion exchange by ettringite. The prepared adsorbents, derived from waste cement and concrete using simple procedures, may offer a cost effective approach for arsenic removal and clean-up of contaminated waters, especially in developing countries.  相似文献   
14.
This paper reports the preparation of galactomannan/ionic liquid composite materials from the corresponding ion gels. Three kinds of galactomannans, that is, fenugreek gum (FG), guar gum (GG), and locust bean gum (LBG) and an ionic liquid of 1-butyl-3-methylimidazolium chloride (BMIMCl) were used. When the galactomannan/BMIMCl gels were immersed in ethanol, followed by dryness under reduced pressure, the galactomannan/BMIMCl composite materials were obtained. The crystalline structures of galactomannans in the materials were evaluated by the powder X-ray diffraction measurement. The mechanical property of the FG/BMIMCl composite material under compressive mode was superior compared with the GG and LBG/BMIMCl composite materials. Then, FG films compatibilized with polymeric ionic liquids (PILs) were also prepared by in situ radical polymerization of polymerizable ionic liquids, 1-(3-acryloyloxypropyl)-3-vinylimidazolium bromide and 1-methyl-3-vinylbenzylimidazolium chloride by AIBN in mixtures of FG with BMIMCl. The mechanical properties of the resulting films were affected by the FG/PIL ratios as well as the unit ratios in PILs.  相似文献   
15.
Ohura T  Kitazawa A  Amagai T 《Chemosphere》2004,57(8):831-837
The occurrence of a mutagenic compound, 1-chloropyrene (Cl-Py), in extracts of ambient particulate matter at an urban site in Japan has been investigated. Samples were collected with a high-volume air sampler for 24 h periods over the course of 1 week in winter (February), spring (May), summer (August), and autumn (November) 2002. The Cl-Py levels showed seasonal variation, ranging from 2.4 pg/m(3) (summer) to 18.9 pg/m(3) (winter). This variation would indicate that the lower temperatures in winter results in an increased distribution of Cl-Py from vapor phase to the particle phase. In addition, there is also the possibility that ambient Cl-Py is emitted from seasonal sources or is susceptible to photodegradation by sunlight, or both. The photodegradation of Cl-Py in a laboratory experiment was conducted to simulate the compound's fate on airborne particle surfaces. The degradation of Cl-Py proceeded by a first-order reaction with a rate constant of 0.72 h(-1). In the presence of a radical sensitizer, 9,10-anthraquinone (AQ), the photodegradation rate of Cl-Py was elevated in comparison with the rate in the absence of AQ. In addition, the dechlorination of Cl-Py (i.e., the formation of Py) occurred in the presence of AQ.  相似文献   
16.
17.
Manufacture of strand board made from construction scrap wood   总被引:1,自引:0,他引:1  
The objective of this research was to evaluate the physical and mechanical properties of strand board made from construction scrap wood. The strand board was manufactured using Sugi (Cryptomeria japonica D. Don) and Douglas-fir (Pseudotsuga japonica) strands selected from construction scrap wood. The strands were oriented, and three-layer (face/core/face) strand board of three types was produced: one in which the strands of the face layer were oriented at a right angle to those of the core layer (R board), another in which the strands of the face layer were oriented parallel to those of the core layer (P board), and a third in which the strands of both layers were oriented at random (Ra board). The physical and mechanical properties of the boards were evaluated based on Japanese Industrial Standard (JIS). The main results obtained are as follows: the bending strength of the strand board with a density larger than 0.55 g/cm3 exceeded the standard value of type 18 particleboard of JIS A 5908. The bending strength of the strand board was affected by board density, strand orientation and resin content, and became larger with increased density as well as resin content. That of the parallel specimen of P board was the largest among the specimen-orientations and types. The internal bond strength of the strand board with a density larger than 0.55 g/cm3 exceeded the standard value of type 18 particleboard and type 24-10 particleboard of JIS A 5908. The internal bond strength was markedly affected by the resin content of the core layer, and became larger with increased density. The thickness swelling of the strand board decreased with increased resin content, and become larger with increased density.  相似文献   
18.
The safety of Tinospora cordifolia and its potential to protect against ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells were investigated. To evaluate the safety of T. cordifolia, cell viability and agarose gel electrophoresis were carried out using PC12 cells treated with 0 to 100 μg mL?1 of methanol extract of T. cordifolia. T. cordifolia extracts did not show cytotoxicity ranging 0 to 100 μg mL?1. In addition, T. cordifolia extracts significantly increased cell viability at 1 ng, 10 ng and 1 μg mL?1 concentrations in serum‐deprived medium compared to control. To confirm the protective role against UV‐induced damage, PC12 cells alone or in the presence of 10 ng, 100 ng, or 1 μg mL?1 of T. cordifolia extract were exposed to 250, 270 and 290 nm of UV radiation, which corresponded to doses of 120, 150 and 300 mJ cm?2, respectively. Treatment with T. cordifolia extracts significantly increased the cell survival rate irradiated at 290 nm. In addition, T. cordifolia extracts significantly reduced cyclobutane pyrimidine dimer formation induced by UV irradiation at all wavelengths. In conclusion, T. cordifolia is not toxic and safe for cells. Our findings can support its application as phototherapy in the medical sector.  相似文献   
19.
Circling and linear flights of a hairstreak Chrysozephyrus smaragdinus were recorded in natural habitat with a high-speed video camera. Circling flight paths were resolved into rotation and shift components; values on X- and Y-coordinates of the butterfly position were separately extracted against time and fitted with a regression line composed of a sinusoidal curve and a linear line. From the obtained parameters, diameter, rotation number, and flight velocity were calculated. Flapping movements were also analyzed. Two types of circling flights, horizontal and vertical, were discriminated. In both flights, the rotation diameter was about 10 cm, rotation number of 3/s, flight velocity of 0.9 m/s, and wing-beat frequency of 20/s. The coordination of paired butterflies in circling flight showed a higher correlation in the horizontal circling flight. In the vertical circling flight, butterflies accelerated the downstroke speed of the wing in the ascending phase. They flew about four times faster in linear flights than in circling flights due to the higher frequency of wing beats.  相似文献   
20.
A sample of commercial BADGE was fractioned by HPLC and eight impurities including novel propyl derivatives (2), (5) and (6) were identified by NMR spectrometry, FAB-MS and GC-MS. The estrogenicity, both agonist and antagonist, of fractions containing these impurities was measured with a yeast two-hybrid assay incorporating the human (hER alpha) and a competitive binding assay for hER alpha (ELISA). In the yeast two-hybrid assay, estrogenic antagonist activity was found in two fractions, while estrogenic agonist activity was not found in any. In the ELISA method, the binding affinity to hER alpha was found in three fractions. It is probable that a comprehensive assessment of the estrogenic properties of commercial BADGE, and their implications for human health, will require examination of all its components as described here.  相似文献   
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