小鼠皮肤切创愈合过程中纤维细胞募集和分化的时间依赖性

目的 观察小鼠皮肤切创愈合过程中,纤维细胞募集和分化随时间变化的规律性.方法 应用免疫荧光技术共定位纤维细胞[共表达CD45、Ⅰ型前胶原(procollagen Ⅰ)]和肌成纤维细胞[共表达CD45、平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)],计数纤维细胞及其分化成的肌成纤维细胞.结果 ...     

小鼠皮肤损伤后时序芯片数据分析及关键基因的筛选

目的 应用生物信息学方法对皮肤损伤后不同时间点的差异表达基因(differentially expressed genes,DEGs)进行分析,为法医学皮肤损伤时间推断(wound age estimation)提供理论依据.方法 从基因表达综合数据库(gene expression omnibus,GEO)下载基因芯...     

Can canines alone be used for age estimation in Chinese individuals when applying the Kvaal method?

Due to the secondary dentin formation, the dental pulp undergoes changes in shape throughout life. Based on this phenomenon, the Kvaal method has been applied to various populations for age estimation, and its usefulness has been verified. When applying the Kvaal method to Chinese subjects, we observed a relatively strong correlation between mandibular canines and age. This study notes the correlation between canines and chronological age and is the first to identify which canine is most closely related to chronological age. In addition, a new, simpler formula is determined based on canines according to Kvaal’s methodology. The radiographs of 360 individuals from northern China were selected, from which the widths and lengths of the pulp from four canines were measured according to the Kvaal method. Next, inter- and intra-observer reliabilities were analyzed in order to assess the repeatability of these measurements. The correlation between measurements and age was examined, and Chinese-specific age estimation formulae were derived. The results revealed that the ratios from the left maxillary canine exhibited the strongest correlation with age compared to the other canines, whereas the left mandibular canine showed the weakest correlation, which may contribute to the overall poor correlation of mandibular canines with age. What’s more, the formula derived from the left maxillary canine in this study displayed the highest coefficients of determination, and the formula derived from all canines showed the lowest residuals. Both of these formulae performed better than the Chinese-specific formula derived from six different types of teeth in our previous study, which had formerly possessed the highest coefficients of determination and the lowest residuals. Thus, we concluded that canines do play an important role in age estimation in the Chinese population, and the correlation between maxillary canines and chronological age is stronger than that of mandibular canines, although no distinct trend as to which side is better correlated with age was established. Going forward, we recommend the analysis of additional samples from different geographical regions and populations to further verify the importance of canines in age estimation.     

Regulating the retirement age—Lessons from Nordic pension policy approaches

The likelihood that longevity will continue to increase has generated a search for regulation that make people work longer as they live longer, and thus not just containing pension expenditure but also enlarging labor supply, economic growth, and tax revenue. In public pension policy, Nordic countries have led the world with three types of approaches aimed at making people retire later. The first came when Sweden, followed by Finland and Norway, installed life expectancy coefficients in benefit calculation formulas. The second followed as Finland introduced age-related accrual rates and the third when Denmark indexed the pensionable age to developments in life expectancy. Since economic incentive-based regulations failed to raise exit ages sufficiently, Finland and Sweden subsequently linked pensionable ages to life expectancy like Denmark. While this policy brings out inequalities in health and workability, the fact that countries found it necessary to index the pensionable age to longevity instead of just relying on economic incentives in regulating retirement behavior may hold lessons for other countries.