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21.
The 87Sr/86Sr ratios in monthly precipitation in the forested basin at Kawakami, central Japan, varied seasonally from 0.709 to 0.711 in spring to as low as 0.7062 ± 0.0004 in autumn over nine years from 1987 to 1995. The seasonal variation can be explained in terms of the mixing of three sources of Sr: sea salt (87Sr/86Sr 0.70917), soluble eolian minerals originating from deserts in continental Asia ( 0.711), and biogenic materials growing on soils derived from the volcanic rock substrates in the vicinity ( 0.706). It is estimated that the contribution of sea-salt Sr into the Kawakami rain Sr is relatively constant (10 ± 5%) and that more than half of the Sr is of biogenic origin throughout the year except during spring rains when 50% of the Sr is due to the dissolution of Ca-minerals from Asian dusts. The dominant contribution of eolian components to spring rains is consistent with the high concentration of 3H, which is typical of air masses from Asia.  相似文献   
22.
Wastewater from clinical institutions contains a considerable amount of toxic substances. Among the toxic substances, antineoplastics may induce carcinogenesis, teratogenesis, and the emergence of mutant microorganisms in the environment. Although the incineration or chemical treatments of disposed antineoplastics are recommended, a high energy during incineration and a careful quality control during chemical treatment are required. In this study, we determined the conditions for the electrolytic treatment of an antineoplastic, epirubicin hydrochloride (EH), using two platinum electrodes with a constant current of 100 mA. We analyzed the cytotoxicity, mutagenicity and antibacterial activity of electrolyzed EH and compared them with those of unelectrolyzed EH. Nearly 100% cytotoxicity, mutagenicity and antibacterial activity were eliminated and HPLC did not detect an EH molecule, in the case of electrolysis for 6 h. We also examined the biological cytotoxicities of electrolyzed irinotecan hydrochloride, vincristine sulfate, mitomycin C, paclitaxel, methotrexate and cisplatin, and found that 72.1-99.999% toxicity was eliminated by electrolysis under the same conditions. The biological toxicity of a mixture of these drugs was determined to be decreased by approximately 99% by electrolysis under the same conditions.  相似文献   
23.
Extraction and identification of beta-nitrostyrene from smoked chicken is described. Commercially obtained smoked chicken was homogenised and extracted with chloroform-methanol (2:1). The extracts were fractioned by silicic acid column chromatography. The purified extract using thin-layer chromatography was identified by a colour reaction (this qualitative method for some nitrated compounds is developed this time), high pressure liquid chromatography and gas chromatography/mass spectrometry. The concentration of beta-nitrostyrene in the smoked chicken was 94 ppb. The average recovery of added beta-nitrostyrene was 107%. However, the toxicity of this material was not tested in the present paper.  相似文献   
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25.
People to be born in the future have no direct influence on current affairs. Given the disconnect between people who are currently living and those who will inherit the planet left for them, individuals who are currently alive tend to be more oriented toward the present, posing a fundamental problem related to sustainability. In this study, we propose a new framework for reconciling the disconnect between the present and the future whereby some individuals in the current generation serve as an imaginary future generation that negotiates with individuals in the real-world present. Through a laboratory-controlled intergenerational sustainability dilemma game (ISDG), we show how the presence of negotiators for a future generation increases the benefits of future generations. More specifically, we found that when faced with members of an imaginary future generation, 60% of participants selected an option that promoted sustainability. In contrast, when the imaginary future generation was not salient, only 28% of participants chose the sustainable option.  相似文献   
26.
Furukawa K  Takahashi Y 《Chemosphere》2008,73(8):1272-1278
Most studies on diffusion of metal ions in various water-rock systems have dealt with free ions (hydrated ions). However, it is often the case that metal ions are dissolved as complexed species such as with humic substances (HS) in natural waters. Hence, we need to study the diffusion behavior of these complexes in order to understand fully the diffusion phenomenon in natural. In this study, the diffusion coefficients of free metal ions (M(z+)) and their complexes with HS (M-HS) were compared to understand the effect of complexation with HS on the diffusion of metal ions such as Co(2+), Cd(2+), and rare earth elements (REE(3+)). Although the diffusion coefficients of free metal ions depend on ionic potential, such dependence was not observed in the presence of HS. Comparing the diffusion coefficients of metal complexes with ethylenediaminetetraacetate (EDTA), fulvic acid, and humic acid showed that the molecular weight (MW), or the size of the ligand, is of primary importance for the diffusion of M-HS. As a consequence, the diffusion coefficients of all REE(3+) were similar in the presence of HS, while they were different in the absence of HS due to the different size of each REE(3+). The similarity among the diffusion coefficients of REE-HS was caused by the much larger size of HS compared with each ion. However, the distribution coefficients of M-HS were not similar among REE(3+), Cd(2+), and Co(2+). REE(3+) and Cd(2+) which have higher affinities for larger MW fraction in HS diffused slower than Co(2+) which favors smaller MW fraction. The results show that the affinity for different MW fractions among HS controls the diffusion of M-HS, which must be important to predict precisely the diffusion behavior of metal ions bound to HS in natural systems.  相似文献   
27.
The relationship between RNA/DNA ratio and egg productivity of adult Paracalanus sp. females was investigated in the frontal area of the Kuroshio current off Kinkazan Island and Boso Peninsula, Pacific coast of Japan in 1989 and 1990, respectively. In the Kuroshio front off Kinkazan Island, the RNA/DNA ratio of females in the surface layer ranged from 3.87 to 6.92 along a transect 8 miles across the front. In the Kuroshio front off Boso Peninsula, the RNA/DNA ratio varied between 5.15 and 7.27 for 32 h in the course of tracking a drifter launched in the front. The RNA/DNA ratio of the females in both frontal areas tended to increase together with ambient chlorophyll-a concentration, and the relationship fitted to Ivlev's formula (P<0.05). The number of eggs laid in filtered sea-water during 24 h (egg productivity) was also positively correlated with the ambient chlorophyll a concentration (P<0.05). There was a positive correlation (P<0.001) between RNA/DNA ratio and egg productivity, and RNA/DNA ratios accounted for about 70% of variation of the egg productivity. Judging from RNA/DNA ratios and female egg productivity in both frontal areas, relatively large physiological or reproductive changes could possibly occur in small temporal and spatial scales in association with change in phytoplankton abundance.  相似文献   
28.
Collaborative activities with business partners have potential to improve environmental performance of product and life cycle assessment (LCA) is an essential technique to implement eco-design of product and production process. However, collection of LCA data from supply chain is a major issue for LCA practitioners. We propose a Supply Chain Collaboration Model (SCCM), which is a framework for collecting producer-specific LCA data from business partners and for promoting improvement activity of product environmental performance. We demonstrate the practicability of the SCCM using three case studies. In each case study, two or three partner companies organized a product improvement project and carried out process analysis techniques such as LCA and material flow cost accounting (MFCA). As a result, improvement activities from the economical standpoint could provide an incentive for business partners to collect LCA data, and thus the SCCM is an effective framework for eco-design.  相似文献   
29.

Purpose  

The purpose of this study was to evaluate the influences of volatile organic compounds (VOCs) emissions on hazardousness and photochemical reactivity and to propose efficient VOCs abatement strategies.  相似文献   
30.
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