Morphological and Biochemical Changes During Aging and Photoaging of the Skin of C57BL/6J Mice

The differences between the dorsal skin of 11- and 16-week-old C57BL/6J mice were examined morphologically and biochemically. The dermis of the 16-week-old mice was thinner than that of the 11-week-old mice due to decreases in the amounts of soluble collagen and elastin. Next, the changes in dorsal skin exposed to UVA irradiation for 8 weeks (576 J/cm2) were examined in 3 (younger)- and 8 (older)-week-old C57BL/6J mice. The thickness of the dermis was not significantly different between the UVA-irradiated and control mice in either the younger or older group. The increase in the amount of collagen was related to the increase in the level of soluble collagen in the younger mice. In contrast, it was related to the increase in the level of insoluble collagen in the older mice. In the UVA-irradiated older mice, the activity of the latent form of MMP-13 was significantly higher than that in the control mice. These results suggest that aging and UVA-induced photoaging in the skin are histologically and biochemically different phenomena

Prevalence and Factors Associated with Hepatitis C Virus Infection among Myanmar Blood Donors

We studied the prevalence of hepatitis C virus infection among blood donors from 3 hospitals of Central Myanmar and 7 hospitals of Lower Myanmar in the Yangon area, and analyzed the factors associated with the infection. The study period was from November, 2005 to June, 2007. A pre-tested questionnaire was used to obtain information on age, ethnic group, marital status, tattooing, body piercing, history of receiving transfusions, and liver diseases in self and in sexual partners. Data on seropositivity to hepatitis C, hepatitis B and human immunodeficiency virus infections were recorded. A total of 65,240 blood donors participated in the study. Their ages ranged from 18 years to 60 years (mean±SD＝29.5±9.3). The male-to-female ratio was 6：1. The prevalence of the antibody to hepatitis C was found to be 0.95% with varying rates (0.34 to 2.03) among hospitals. Females had a slightly higher rate (1.06%) than males (0.93%) (p＝0.237). Multivariate analyses revealed the following factors to be related to HCV infection:HIV infection, odds ratio (OR)＝3.0 (p＝0.003);history of liver disease, OR＝8.9 (p＝0.001);and age 30 years and above, OR＝2.6 (p＝0.001). We discuss the varying prevalences of HCV around the world

Microstructures and luminescent properties of Ce-doped transparent mica glass-ceramics

Transparent mica glass-ceramics were prepared by heating parent glasses that had been doped with 0.5-15 mol% CeO2. During the melting and heat treatment, Ce4+ ions in the specimens were reduced to Ce3+ ions, and one or both of these ion species were then replaced with Li+ ions in the interlayers of the separated mica crystals. However, scanning transmission electron microscope (STEM) and Z-contrast imaging revealed that the mica crystals did not contain the same amount of Ce. On excitation at 254 nm, the parent glasses and glass-ceramics emitted blue light, which originated from the 5d to 4f transition of the Ce3+ ions. The emission of the glass-ceramic containing a smaller amount of Ce was attributed to the Ce3+ ions in both the glass phase and the mica crystals, whereas that of the glass-ceramics containing a larger amount of Ce was caused mainly by Ce3+ ions in the mica crystals. The dependence of the emission band of the parent glasses on the amount of Ce was a unique feature of the Ce-doped transparent mica glass-ceramics and was not observed in previous studies of Eu-doped parent glasses and mica glass-ceramics.ArticleMATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS. 177(7):504-509 (2012)journal articl

HumanMimic: Learning Natural Locomotion and Transitions for Humanoid Robot via Wasserstein Adversarial Imitation

Transferring human motion skills to humanoid robots remains a significant challenge. In this study, we introduce a Wasserstein adversarial imitation learning system, allowing humanoid robots to replicate natural whole-body locomotion patterns and execute seamless transitions by mimicking human motions. First, we present a unified primitive-skeleton motion retargeting to mitigate morphological differences between arbitrary human demonstrators and humanoid robots. An adversarial critic component is integrated with Reinforcement Learning (RL) to guide the control policy to produce behaviors aligned with the data distribution of mixed reference motions. Additionally, we employ a specific Integral Probabilistic Metric (IPM), namely the Wasserstein-1 distance with a novel soft boundary constraint to stabilize the training process and prevent model collapse. Our system is evaluated on a full-sized humanoid JAXON in the simulator. The resulting control policy demonstrates a wide range of locomotion patterns, including standing, push-recovery, squat walking, human-like straight-leg walking, and dynamic running. Notably, even in the absence of transition motions in the demonstration dataset, robots showcase an emerging ability to transit naturally between distinct locomotion patterns as desired speed changes