Ten-gram scale SiC@SiO2 nanowires: high-yield synthesis towards industrialization, in situ growth mechanism and their peculiar photoluminescence and electromagnetic wave absorption properties.

SiC@SiO2 nanowires, as a functional nanocomposite, have attracted widespread attention due to their fascinating performance and broad application prospect. However, the low-cost, high yield preparation of large-scale SiC@SiO2 nanowires is still a bottleneck, which hinders their industrial application. Herein, a carbothermal reduction strategy has been developed to synthesize SiC@SiO2 nanowires, which breaks through the handicap of the traditional growth pattern that uses the aid of a substrate. Systematic characterization results illustrate that the yield of the as-obtained products greatly depends on the heating rate, and ten-gram scale SiC@SiO2 nanowires (∼27.2 g) composed of a cubic ß-SiC core and homogeneous amorphous SiO2 coating are achieved under the optimum process parameters. The in situ mechanisms of expansion-insertion-growth and inhibition of expansion-package-obstruction are proposed to rationally interpret the growth process of SiC@SiO2 nanowires and the effect of various heating rates, respectively. Furthermore, the SiC@SiO2 nanowires display violet-blue photoluminescence and electromagnetic wave absorption properties. This study not only provides some beneficial suggestions for the commercial production of SiC@SiO2 nanowires, but also reveals promising applications of SiC@SiO2 nanowires in the optical and electromagnetic shielding fields. Moreover, the developed novel in situ growth mechanism enriches the growth theory of one-dimension nanomaterials and offers inspiration for their industrial-scale production.

Coping skills training for children: effects on distress before, during, and after hospitalization for surgery.

Thirty-three parent-child dyads (children's mean age = 7.2 years, SD = 1.2) were randomly assigned to information, anxiety reduction, or coping skills presurgical preparatory interventions. All groups received the "information" procedure that described typical hospitalization and surgery experiences via a puppetry film viewed 1 week prior to hospital admission. In the anxiety reduction group, parents also learned procedures (e.g., relaxation) to help them reduce their own distress. Parents in the coping skills group learned how to help their children use coping self-talk and related techniques. The coping skills intervention was expected to assist children most effectively, although the anxiety reduction procedure was also expected to improve adaptation relative to the information condition. These hypotheses were generally supported. Anxiety reduction and coping skills groups, compared to the information group, reduced children's self-reported fearfulness and parents' reported distress. Furthermore, only the coping skills group, compared to the information group, exhibited fewer maladaptive behaviors during hospitalization (ratings by observers) and less problematic behavior in the preadmission week and second postdischarge week (daily parental diaries). Theoretical explanations for these results are discussed in light of the similar findings obtained by Peterson and Shigetomi (1981).

Cell-mediated and humoral immune responses to aspermatogenic antigen in experimental allergic orchitis in the guinea-pig.

Guinea-pigs were immunized with a defined and highly potent aspermatogenic antigen, G75m, and the occurrence of orchitis was correlated with (1) cell-mediated immune response to G75m, determined by lymph node cell proliferation and by secretion of macrophage migration inhibitory factor (MIF) by peritoneal exudate cells, and (2) humoral antibodies to G75m and to cell surface antigens of guinea-pig testicular cells, by radioimmunometric assays. A consistent temporal relationship between cell-mediated immune responses and disease was found: lymph node cell proliferation was positive by Day 4, followed 3 days later by maximum secretion of MIF, and orchitis lesions were manifest on Day 10. In contrast, maximal IgG antibodies to G75m or to the surface antigens of spermatozoa/testicular cells were detected at a time when cell-mediated immune responses and active testicular lesions had subsided. In individual animals, lymph node cell proliferation increased with severity of orchitis, while MIF secretion by peritoneal cells increased with orchitis only late in the disease. Early in disease, MIF response showed a negative correlation with orchitis. Moreover, peritoneal injection of oil reduced the incidence of early lymph node cell proliferative responses, and delayed the onset of testicular disease. These findings are consistent with competition between different inflammatory sites for recently antigen-activated T lymphocytes. We conclude that (1) the development of orchitis correlates with cell-mediated immune responses to purified aspermatogenic antigens but not with IgG antibody responses, and (2) when the same animal is used to assess different aspects of cellular immunity and autoimmune disease, one study may significantly influence the other.