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91.
Alkyl esters of p-hydroxybenzoic acids (parabens), an endocrine disrupter, are used as preservatives in cosmetics and foods. In this study, to understand the relationship between parabens and differentiation in infants, the effects of parabens on apoptosis induced by serum deprivation in PC12 cells were investigated. In addition, apoptosis-related factors were assayed. As results, a tendency toward enhancement of apoptosis was observed in the cells cultured in the serum-free medium with methylparaben, and this tendency was suggested to be related to the contents of BAD, a pro-apoptotic protein. Butylparaben did not show any tendency to enhance apoptosis.  相似文献   
92.
Since the late 1980s, spider mite pests have caused serious damage to many moso bamboo (Phyllostachys pubescens) forests in China’s Fujian province. The culms of this plant are an essential component of the building and handicraft industries, and the shoots are a prized food item in many Asian countries. Furthermore, bamboo forests play an important soil conservation role in mountainous areas. We examined pest mite outbreaks in several moso bamboo plantations in Fujian, and could show that a change in cultivation style from polyculture (a kind of mixed forest) to monoculture (all plants other than bamboo were removed) was primarily responsible for the local extinction of an important predaceous mite species. This phenomenon is due to the periodic shedding of leaves by the bamboo, which forces the predator mites occurring on bamboo to switch to prey mite species that occur on other plants. We then tried to elucidate the factors that resulted from such a cultivation change. Adopting a computer simulation approach, we could successfully show that at least two plants, moso bamboo and Chinese silvergrass, are necessary to maintain stable predator–prey interactions in moso forests. That is, systems consisting of one common predator and two host-specific pest mites on different host plant species frequently became stable when the pest mites were at low density. This finding indicates clearly that bio-diversity, even when it consists of only two plants and three mite species as in this study, is necessary for the sustainable regulation of large-scale forests, such as moso bamboo plantations.  相似文献   
93.
We studied the correlation between male-male aggressive behavior of the spider mite, Schizotetranychus miscanthi and winter coldness, a factor hypothesized to correlate with the degree of relatedness of the interacting males through the frequent occurrence of mother-son mating in the spring. Thirty-one samples from various populations throughout Japan were added to previous data. A cluster analysis revealed two clinal trends for male-male aggression in S. miscanthi in regions of light or no snowfall. The two clines may represent a dimorphism within the species, each having a similar clinal trend within Japan. Further support for the hypothesis that male overwintering survival affects male-male aggressiveness came from a comparison between regions of heavy snowfall and those of light or no snowfall. In regions with heavy snow insulation, overwintering survival may not be as high as in other areas, and there was no correlation between male aggressiveness and the minimum winter temperature. However, there was a significant correlation in regions of light snow. Received: 26 May 1998 / Received in revised form: 16 December 1998 / Accepted: 30 December 1998  相似文献   
94.
To understand the characteristics of non-methane hydrocarbon (NMHC) abundance in an urban air of Nagoya, one of the metropolitan areas of Japan, 48 species of C2–C11 NMHCs were measured with a measurement system, developed in this study, by using gas chromatography with flame ionization detection (GC/FID) continuously for one year from December 2003 to November 2004.Annual mean concentration of NMHCs in normal and propylene equivalent (PE) in Nagoya was compared with those in four urban areas of Seoul, London, Lille, and Dallas to extract characteristics of urban air. While the absolute values of the normal and PE concentrations of alkanes, alkenes, alkyne, and aromatics were significantly different among these urban areas, the proportions of each chemical group to the total NMHC were not so different.In Nagoya, the total normal concentration was high from November to February and low from June to August. The pattern of the seasonal variation was influenced mainly by that of alkanes. On the other hand, the total PE concentration was high from July to December and low from January to June. The pattern of the seasonal variation was influenced mainly by those of alkenes and aromatics. Particularly the normal concentration of isoprene was high from May to September because of large emission associated with activity of plants. As the results, in summer, the PE concentration of isoprene was especially high, and its contribution to the total NMHCs measured in this study was approximately 40%. The total PE concentrations were high in summer when the concentration of OH radicals is also high, suggesting that the productions of ozone and secondary organic aerosol (SOA) are likely to be promoted in summer of Nagoya.  相似文献   
95.
Three experiments were designed to determine the effects of SO2 concentration on two Southeastern oat varieties—Caroiee and Coker 227. The plants were grown under uniform conditions prior to and after the experimental growth period. During the 7 to 14 day experimental growth period the plants were subjected to four growth temperatures (18/14, 22/18, 26/22 and 30/26° C day/night temperatures) and exposed 2 or 4 times to specific concentrations of SO2 (from 0 to 4 ppm) for 1.5 or 3.0 hr periods. In the first two experiments, the exposure temperatures were varied (18° to 30° C). In the third design, the exposure temperatures remained constant and two exposure relative humidities (55 and 80%) were used. Injury and growth reductions were more severe in Coker 227 than in Caroiee. Root dry weight (RDW) was affected more than top dry weight (TDW). Plants were more sensitive at the higher growth temperatures. Exposure temperatures had little to variable effects. Plants were more sensitive at 80% than at 55% relative humidity. Biomass was reduced at 0.4 ppm SO2 after four 3 hr exposures and at 0.75 ppm after two 1.5 hr exposures, but growth was also increased as often. These concentrations approached the accepted threshold for adverse effects to sensitive vegetation. Foliar injury was highly correlated with growth reductions.  相似文献   
96.
Abstract

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 °C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.  相似文献   
97.
Hemp bast holocellulose fiber (Cannabis sativa L. Subsp. Sativa) was oxidized by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation at various NaClO addition levels in water at pH 10. When carboxylate contents of the oxidized products were 1.5–1.7 mmol/g, TEMPO-oxidized cellulose nanofibrils almost completely dispersed at the individual nanofibril were obtained by mechanical disintegration of the TEMPO-oxidized hemp bast holocelluloses in water, where the nanofibrillation yields were 98–100 %. The sugar composition analysis revealed that most of hemicelluloses originally present in the hemp bast holocellulose were degraded and removed from the solid oxidized products, providing almost pure TEMPO-oxidized celluloses. X-ray diffraction patterns of all TEMPO-oxidized hemp bast holocelluloses had the same cellulose I crystal structure and similar crystallinity indices and crystal widths, indicating that carboxylate groups formed by the oxidation were selectively present on the crystalline cellulose microfibril surfaces in the holocellulose. However, the weight recovery ratios and viscosity-average degrees of polymerization of the TEMPO-oxidized hemp bast holocelluloses decreased to 69–59 % and 470–380, respectively, when their carboxylate contents increased to 1.5–1.7 mmol/g by the TEMPO-mediated oxidation. Atomic force microscopy height images showed that the nanofibril widths were 2.7–2.9 nm, and the average nanofibril lengths decreased from 590 to 400 nm as the NaClO addition level was increased from 7.5 to 12.5 mmol/g in the TEMPO-mediated oxidation.  相似文献   
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100.
Immunoassay methods are generally used for measuring of allergenic substances. However, they need special facilities, skilled handling, and time-consuming procedure. In this work, a fiber-optic immunoassay system which could measure allergen by fluorescent intensities of immune complexes formed by allergens and fluorescently labeled antibodies was established. Immune complexes absorbed on the optical fiber probe surface, and excitation light was injected into the probe, then evanescent field is created in the proximity of the probe. The fluorophores were excited by the evanescent light, and fluorescence was detected by a photo diode. The target allergen detected by our system was Der f1 derived from Dermatophagoides farinae that is one of the house dust mite and major source of inhaled allergens. The fluorophore used labeling on detecting antibody was cyanine 5. The system enabled to detect and quantitatively determine of Der f1. The measurement range was from 0.24 to 250?ng/ml, and the result competes with ELISA. The measurement time was 16?min/sample. The immunoassay system was applied to measurement of Der f1 from actual dust samples. Calculated values of Der f1 showed good correlations between the fiber-optic fluoroimmunoassay and ELISA.  相似文献   
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