Although short-lived vertebrates can serve as model animals for understanding the mechanism of aging, whether the annual fish Nothobranchius rachovii is suitable for studying aging remains an open question. In this study, histochemical, biochemical, and genetic techniques were used to determine the age-related markers at three different developmental stages of the annual fish N. rachovii. Histochemical studies revealed that the expression of senescence-associated beta-galactosidase and accumulation of lipofuscin increased with age. In biochemical assays, lipid peroxidation and protein oxidation increased with age, whereas the activities of catalase, glutathione peroxidase, and superoxide dismutase decreased with age. Genetic analysis established that the activities of telomerase had no apparent relationship with age, but telomere lengths reduced with age from 11.5 +/- 1.98 to 3.58 +/- 0.74 kb. Taken together, these results indicate that the annual fish N. rachovii may be useful as an animal model for the study of aging.

SummaryExtending lifespan by lowering ambient temperature in the habitat has been shown in a variety of organisms. Its mechanism, however, remains elusive. In this study, we examined the survivorship and the aging process of the annual fish (Nothobranchius rachovii) reared under high (30°C), moderate (25°C) and low (20°C) ambient temperatures. The results showed that low ambient temperatures prolong survivorship, whereas high ambient temperatures shorten survivorship. At low ambient temperature, expression of senescence-associated b-galactosidase, lipofuscin, reactive oxygen species, lipid peroxidation, protein oxidation, mitochondrial density and ADP ⁄ ATP ratio were reduced compared with those reared at high and moderate temperatures, whereas catalase activity, Mn-superoxide dismutase activities, mitochondrial membrane potential and the levels of ATP, ADP, Sirt1 and Forkhead box O expression were elevated. The expression levels of Hsp70 and CIRP showed no significant difference under any of the ambient temperatures tested. We concluded that cellular metabolism, energy utilization and gene expression are altered at lower ambient temperature, which is associated with the extension of lifespan of the annual fish.

Hydrogen spillover and storage for single-site metal catalysts, including single-atom catalysts (SACs) and single nanocluster catalysts, have been elucidated for various supports but remain poorly understood for inert carbon supports. Here, we use synchrotron radiation-based methods to investigate the role of single-site Ti catalysts on graphene for hydrogen spillover and storage. Our insitu angle-resolved photoemission spectra results demonstrate a bandgap opening and the X-ray absorption spectra reveal the formation of C−H bonds, both indicating the partial graphene hydrogenation. With increasing Ti deposition and H2 exposure, the Ti atoms tend to aggregate to form nanocluster catalysts and yield 13.5% sp 3 -hybridized carbon atoms corresponding to a hydrogen-storage capacity of 1.11 wt% (excluding the weight of the Ti nanoclusters [1]). Our results demonstrate how a simple spillover process at Ti SACs can lead to covalent hydrogen bonding on graphene, thereby providing a strategy for a rational design of carbon-supported single-site catalysts.

Abstract─ ─ ─ ─With the growing global population, there is an increasing rate of human contact. In particular, we often find that many public restroom users collect water with cupped hands to pour on the faucet switch after washing their hands due to their suspicions about the lack of hygiene. This study redefined the faucet form by using form generation, and improved the design by addressing the problem of faucet hygiene based on the user behavior-centered concept. After the Design for Assembly (DFA) was found by 10 expert designers, the samples were created to be used in a survey on users' hygienic fear and user satisfaction. The statistical analysis of the survey results shows that 75% of subjects were unafraid of the newly designed faucets and 100% of them gave significant and positive satisfactory responses for faucets based on user-centered design in terms of operation and aesthetics.When using the newly designed faucets, the subjects still washed them with water, but the amount of wasted water was significantly reduced through the design improvement.