Aging is a complicated multifactorial process in which a progressive decline in the physiologic function of organisms occurs. Oxidative stress and reactive oxygen species (ROS) have been proposed to be major cause of aging and other aging-related neurodegenerative conditions such as Alzheimer's disease.1,2) Aging-related oxidative damage in the brain and memory impairment mainly result from an imbalance between ROS generation and antioxidant enzyme activities. The overproduction of ROS or decrease in antioxidants in the brain can cause lipid peroxidation, nuclear and mitochondrial DNA damage, and protein oxidation and finally affect the normal functions of organisms. [3][4][5][6] D-Galactose (D-gal) is a reducing sugar normally present in the body. When present at levels greater than its normal content, it can be oxidized into aldehydes and hydrogen peroxide (H 2 O 2 ) by galactose oxidase. 7,8) It has been shown that D-galtreated animal models show aging-related changes including the impairment of spatial learning and memory, object novelty preference, and locomotor activity, 9,10) and increased production of ROS and lowered activities of antioxidant enzymes. 11,12) Other studies demonstrated that long-term subcutaneous injection of D-gal in mice induced decreased immune responses and increased cell karyopyknosis, apoptosis, and caspase-3 protein levels in hippocampal neurons.11,13) Therefore mice continuously injected with D-gal have been extensively used for pharmacologic research on brain aging.(Ϫ)-Epigallocatechin-3-gallate (EGCG) is a member of the catechin family and a major polyphenolic constituent of green tea.14) It was reported that EGCG has potent ironchelating, antioxidant, antiinflammatory, anticancer, and neuroprotective activities. [15][16][17][18][19] In particular, EGCG has been shown to have neuroprotective effects by elevating the a-secretase activity of amyloid precursor protein (APP) and conversion to soluble APP-alpha (sAPP-a) and reducing amyloid beta (Ab)-induced neurotoxicity in a 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine (MPTP) mouse model, the "Swedish" APP transgenic (Tg2576) mouse model of Alzheimer's disease, and N2a cells stably transfected with "Swedish" mutant human APP. 20,21) Furthermore, some studies have recently demonstrated that the neuroprotective mechanisms of EGCG are partly due to increasing activities of antioxidant enzymes and decreasing advanced glycation endproduct (AGE)-induced damage in aged rat brain or neuronal cells. 22,23) However, no study has been performed to evaluate whether EGCG has protective effects on aging mice induced by D-gal and its mechanisms of action. In the present study, we induced the aging mice model with D-gal (150 mg/kg/d, 6 weeks subcutaneously (s.c.)) and observed whether EGCG (2 mg/kg/d or 6 mg/kg/d, 4 weeks intragastrically (i.g.)) had potent antioxidant and antiapoptotic neuroprotective effects using behavioral testing and measurements of the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px), con...

BackgroundInternational literature has illustrated that the health impacts of heat waves vary according to differences in the spatial variability of high temperatures and the social and economic characteristics of populations and communities. However, to date there have been few studies that quantitatively assess the health vulnerability to heat waves in China.ObjectivesTo assess the spatial distribution of health vulnerability to heat waves in Guangdong Province, China.MethodsA vulnerability framework including dimensions of exposure, sensitivity, and adaptive capacity was employed. The last two dimensions were called social vulnerability. An indicator pool was proposed with reference to relevant literatures, local context provided by relevant local stakeholder experts, and data availability. An analytic hierarchy process (AHP) and a principal component analysis were used to determine the weight of indicators. A multiplicative vulnerability index (VI) was constructed for each district/county of Guangdong province, China.ResultsA total of 13 items (two for exposure, six for sensitivity, and five for adaptive capacity) were proposed to assess vulnerability. The results of an AHP revealed that the average VI in Guangdong Province was 0.26 with the highest in the Lianzhou and Liannan counties of Qingyuan (VI=0.50) and the lowest in the Yantian district of Shenzhen (VI=0.08). Vulnerability was gradiently distributed with higher levels in northern inland regions and lower levels in southern coastal regions. In the principal component analysis, three components were isolated from the 11 social vulnerability indicators. The estimated vulnerability had a similar distribution pattern with that estimated by AHP (Intraclass correlation coefficient (ICC)=0.98, p<0.01).ConclusionsHealth vulnerability to heat waves in Guangdong Province had a distinct spatial distribution, with higher levels in northern inland regions than that in the southern coastal regions.

There is an unmet need for new techniques and methods of healing critical size tissue defects, by further reduction of invasiveness in implant, cell and tissue-based surgery. This paper presents the development of a new regenerative medicine that combines 3D bio-printing and robotic-assisted minimally invasive surgery techniques to meet this need. We investigated the feasibility of Remote Centre of Motion (RCM) and viscous material extrusion 3D printing. A hypothetical, intra-articular, regenerative medicine-based treatment technique for focal cartilage defects of the knee was used as a potential example of the application of 3D printing in vivo . The results of this study suggest, that RCM mechanism is feasible with viscous material extrusion 3D printing processes, without a major trade-off in imprint quality. The achieved printing accuracy at an average dimensional error of 0.06 ± 0.14 mm in this new modality of 3D printing is comparable to those described in literature for other types of bio-printing. Robotic assisted 3D bio-printing demonstrated here is a viable option for focal cartilage defect restoration.

The nonlinear mechanical behavior of the cornea is closely correlated with the crimping morphology of collagen fibrils. The findings are expected to guide further research of corneal pathologies related to the abnormal microstructure of collagen fibrils.