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We proposed a new separation and recovery process for RE metals from Nd magnet scraps using molten salt electrolysis. The present study focused on the electrochemical formation of RE–Ni (RE = Dy, Nd, Pr) alloys in a molten LiCl–KCl system at 723 K. Cyclic voltammetry was conducted using a Ni electrode in molten LiCl–KCl–RECl3systems at 723 K. In the negative scan for the DyCl3added system, a large cathodic current was observed from 0.70 V (vs. Li+/Li) as a result of the formation of Dy–Ni alloys. In contrast, large cathodic currents as results of the formation of Nd–Ni and Pr–Ni alloys were observed from 0.60 V. On the basis of these results, an alloy sample was prepared by potentiostatic electrolysis at 0.65 V for 1 h using a Ni plate cathode in a molten LiCl–KCl–DyCl3–NdCl3–PrCl3system. The mass ratio of Dy/Nd+Pr in the alloy sample was found to be 50 by ICP-AES. Finally, a Dy permeation experiment was conducted with a new electrolytic cell. [ABSTRACT FROM PUBLISHER]

This article investigates the role that parental socioeconomic status plays in forming the racial gap in home computer use among young school-age children. Descriptive statistics from time diary data of 6- to 11-year-olds in the Panel Study of Income Dynamics, Child Development Supplement, reveal that Black American children spend substantially fewer minutes on the computer than do non-Hispanic White children; however, the racial gap in percentage terms has narrowed between 1997 and 2003. Multivariate analyses indicate that the extent to which parental socioeconomic status explains the racial gap declined between 1997 and 2003 -- in 2003, less than 10% of the gap is explained by family income and household head's education. The pattern of decline is not observed when analyzing the racial gap in reading time. As home computer ownership approaches saturation, the racial gap in computer use time may increasingly reflect the underlying racial boundaries rather than parental status differentials. [ABSTRACT FROM AUTHOR]

Integrating three theoretical explanations for declining rates of marriage in Japan, the authors develop hypotheses in which linkages between benefits of coresidence with parents and marriage timing are moderated by women's own socioeconomic characteristics. To evaluate these hypothesized interactive relationships, data from a panel survey of Japanese women is used to estimate hazard models for the transition from the parental home to first marriage. Results are consistent with the hypothesis that limited domestic responsibilities contribute to later marriage among coresident women with higher levels of human capital. Less evidence is found for the hypothesis that limited living expenses are associated with later marriage among women whose potential husbands are likely to have more tenuous economic prospects. The authors conclude that coresidence with parents plays a potentially important role in the marriage behavior of economically independent women in societies where family formation is relatively incompatible with full-time work for women. [ABSTRACT FROM AUTHOR]

A number of alkylphenolic compounds are used in a variety of commercial products and have been shown in in vitro studies to be weakly estrogenic, but few in vivo data are available addressing this issue in mammals. Human exposure to alkylphenols may occur not only from these environmental contaminants but also through contact with manufactured and metabolic breakdown products. The reproductive function of rats treated subcutaneously with nonylphenol (NP, 500 mg/kg/day) or 17β-estradiol (E[sub 2], 2 mg/kg/day) as a positive control, from postnatal days 1 to 5 was examined after puberty. In addition, masculine sexual behavior, sperm motion, plasma testosterone concentration and histopathological changes in the reproductive organs of the rats were examined. Furthermore, male rats were subjected to an open field test and wheel cage test to evaluate locomotor activity, and the estrous cycle was examined in female rats. All male and female rats exposed neonatally to NP or E[sub 2] showed macroscopic and/or microscopic alterations of the gonads. Females treated with NP or E[sub 2] showed an altered estrous cycle and abnormal reproductive function, while males treated with NP or E[sub 2] showed normal reproduction. In males exposed neonatally to NP or E[sub 2], no abnormalities were observed in locomotor activity, sperm motion or plasma testosterone concentration. The results of this study indicate that early neonatal exposure to NP causes dysfunction of postpubertal reproductive function in female rats, as well as disrupted development of gonads in male and female rats. More detailed studies are warranted to assess the possible risks to human and wildlife reproduction from exposure to NP and other environmental chemicals with estrogenic activity. Human & Experimental Toxicology (2000) 19, 284–296. [ABSTRACT FROM AUTHOR]

Five cases are presented with clinical findings of capito-lunate instability pattern of the wrist. All painful areas and tender points were dorsal, but variable in location and intensity. All plain radiographs and fluoroscopic instability series were normal. None of the cases had an explanation for the dorsal wrist pain other than a positive dorsal capitate-displacement test. Four out of five cases were treated in a cast for 4 weeks and two had subsequent splint immobilization. Although at short-term follow-up two of these five patients became pain-free, none was completely pain-free at long-term follow-up. Three patients treated with a cast had long-term follow-up. Only one could perform his original work. These findings support a clinical condition of midcarpal instability producing dorsal wrist pain reproduced with a simple stress test. Conservative, non-operative treatment will not usually produce long-term pain relief. [ABSTRACT FROM PUBLISHER]

Fluoride incorporation into human enamel from an experimental sealant resin in vivo was investigated. The sealant consisted of a newly synthesized methacryloyl fluoride-methyl methacrylate (MF-MMA) co-polymer resin, which contains acidic fluoride covalently bonded to carbonyl groups and releases fluoride ions slowly by hydrolysis in an aqueous environment. This experimental sealant was applied to the enamel of permanent pre-molars and the control sealant without MF-MMA copolymer to that of the contralateral teeth. Fluoride concentration was determined by an enamel biopsy procedure with acid- etching four weeks after the sealant application. As much as 3500 ppm fluoride was found to be deposited at 10 μm depth in the enamel under the MF-MMA copolymer sealant. The increase in fluoride concentration was significant even at 60 μm. Of the fluoride incorporated into the enamel, from 70 to 80% was present as a tightly bound form. This resin sealant is expected to protect the enamel from caries attack even after detachment of the sealant. [ABSTRACT FROM AUTHOR]