Evaluation of a rapid protein analyzer as a research tool for lean beef composition: Effects of storage time and freezing

The Sprint Rapid Protein Analyzer (CEM Corporation) has introduced a novel method for protein content determination. Dairy and meat industries are adopting this technology, as it is easily integrated in commercial plants; however, its application as a valid tool for meat research requires further evaluation. Using the Dumas method as a reference, the Sprint Rapid Protein Analyzer was tested to evaluate the accuracy, precision and repeatability of the machine, under a variety of different beef muscle sample storage and handling conditions. The samples analysed using the Sprint Rapid Protein Analyzer showed an average within-day relative standard deviation (RSD) of 0.812% and an average inter-day RSD of 1.39%. For samples stored at 4 °C for 24, 48 or 72 h, the RSD ranged between 0.02 and 4.50%. In samples frozen at −35 and −80 °C for 2, 4, 6, 8, 10 and 12 months, the average RSD compared to fresh samples was 2.89%. Thus, the Sprint method, once properly calibrated over the compositional range encountered, may be suitable for use to determine protein content in lean beef research.     

Effect of ageing on healing of bilateral mandibular condyle fractures in a rat model

To examine the hypothesis that conservative treatment is applicable to younger patients with bilateral mandibular condylar fractures, we studied the effect of ageing on the healing of bilateral mandibular condylar fractures in a rat model. Male Sprague–Dawley rats aged 3, 6, and 36 weeks (n = 25/cohort, total n = 75) were divided into a fracture group (n = 12) and a sham control group (n = 12); one rat from each cohort was used as a normal unoperated control. Cell proliferation was evaluated using the bromodeoxyuridine (BrdU) labelling index (LI). Osteochondrogenesis was assessed by the expression of Indian hedgehog (Ihh), type X collagen, and osteocalcin in the condylar head. Condylar fracture healing was found to be delayed by ageing. BrdU LI values in the fracture groups were higher in younger rats than in older rats at 8 weeks after fracture. The number of Ihh-positive cells in the fracture groups increased significantly up to 2 weeks after fracture, and then gradually decreased until 8 weeks after fracture. The findings of this study support the clinical concept of conservative treatment of bilateral condylar fractures in younger patients, but functional issues regarding ramus height and its consequences on occlusion have not been tested in this study.     

THE PREVALENCE OF DEMENTIA AND COGNITIVE IMPAIRMENT INCHINA

Early studies of the prevalence of dementia and cognitive impairment in China indicated low rates, but more recently rates have been rising to the levels shown in other countries. Reasons for these changes are discussed.     

加强老年流行病研究 科学指导老年健康防控

我国目前面临着严峻的人口老龄化和高龄化形势,老年人特别是高龄老人作为我国人口中寿命最长和最脆弱的特殊群体,亟需针对此人群开展深入的科学研究。老年流行病学是研究流行病学理论与方法在老年人研究中的应用科学,整合多种方法开展老年人特殊健康特征分析,获取老年人健康流行病学规律。本期“老年流行病学”重点号文章围绕老年人群慢性病、...     

Effects of a training programme for elderly people on mineral content of the heel bone

Physical inactivity can cause rapid bone loss. Different forms of physical activity are recommended for osteoporosis. The scientific background for such recommendations, however, is usually weak.This study was performed to evaluate whether it is possible to influence bone mineral content in elderly people by regular exercise. A total of 15 women with a mean age of 72 yr took part in a study in which they were given 1 h of training twice a week for 9 mth. Physically inactive patients from an outpatient geriatric unit served as a control group. They were matched in age and did not suffer from diseases that affect the locomotor system.After 10 mth of training no significant increase in bone mineral content, measured in the heel bone, could be found among the participants in the training group. Bone mineral content in the trained subjects was however, significantly higher after this training period than in the control group. The decrease in bone mineral content in the control group was almost the same as in a representative group of the population aged 70 to 79 yr.The cause of the decreased loss of bone mineral content in the physically-active subjects in the study could not be determined, but some contributing factors are discussed. Thus, it appears that physical activity diminishes bone loss due to age and that physical training has a positive effect on bone mineral content compared to that of nonactive controls of the same age. As there are no negative side effects, it has advantages over other forms of therapy, such as pharmacological treatment.     

全瓷贴面树脂粘接老化后颜色及不透光度变化

目的：评价全瓷贴面用不同类型树脂粘接并加速老化后的颜色稳定性和不透光度变化。方法：用IPS e．max PressA1色瓷块制作厚0．4 mm、直径10 mm的瓷片28片,随机分为4组（n＝7）,分别用BEAUTIFIL Flow、DEO-Link SE、Panavia F、Vi-riolink N粘接,LED光固化灯照40 s。将0．5 mm厚瓷贴面树脂复合体放入环境模拟器中加速老化,数字比色仪测量老化前后的颜色值,用CIE L*a*b*颜色系统计算颜色值变化量ΔE和不透光度变化值ΔO,用ANOVA,LSD（L）进行统计学分析。结果：所有材料均有明显的颜色值和不透光度变化。ΔE范围0．6～2．29,其中BEAUTIFIL Flow颜色变化最小,DEO-Link变化较大。ΔO为0．46～2．55。Panavia F不透光度增加最多（P＜0．05）。结论：加速老化可导致所有测试材料颜色变化,但变化量在临床可接受范围之内（ΔE＜3）。