Prevalence and influencing factors of myopia for the Chinese junior high school students / 中华疾病控制杂志

Objective To analyze the mechanism of the influencing factors of myopia for junior high school students in China. Methods Based on the follow-up to 7 119 students in the 3 waves of questionnaire survey of the Chinese Education Panel Survey in junior high school stage, and the variables on students’ myopia status, myopia influencing factors, and two kinds of risk behaviors of myopia including near visual activities and outdoor activities, the mediation effects of the myopia risk behaviors were tested by Logistic regression model. Results The myopia prevalence of 9th graders before junior high school graduation was 66.36%. Time on writing homework significantly increased the risk of myopia，the odds ratio (OR) was 1.17，the 95% confidence interval (CI) was 1.13-1.21, and the time on outdoor sports significantly decreased the risk of myopia (OR=0.80，95% CI:0.75-0.86). Before and after including the risk behaviors into the model, the myopia risk OR(95% CI) of female centralized from 1.84(1.66-2.04) to 1.69(1.51-1.88), the myopia risk OR(95% CI) of urban students’centralized from 1.19(1.03-1.37) to 1.16(1.00-1.34), the myopia risk OR(95% CI) of only children’centralized from 1.20(1.06-1.36) to 1.18(1.04-1.33). With reference to not myopic for both parents, the myopia risk OR(95% CI) of students having one myopic parent centralized from 2.47(2.12-2.88) to 2.44(2.09-2.85), the myopia risk OR(95% CI) of students having parent without myopic centralized from 4.25(3.09-5.86) to 4.13(3.00-5.69). Conclusions Gender, urban and rural, only child, and myopic parents are influencing factors of myopia. These factors have effects on myopia via two kinds of risk behaviors including outdoor activities and near visual activities.

Analysis of the prevalence and influential factors for overweight and obesity of ninth grade students in China / 中华疾病控制杂志

Objective To investigate the prevalence of overweight and obesity in Chinese ninth grade students and to analyze the influential factors that contribute to this situation. Methods A total of 5 967 students were selected from the 2016 China Education Panel Survey. Chi-square test was used to examine the differences in the prevalence of overweight and obesity among different groups and Logistic regression models were used to analyze the factors affecting obesity in boys and girls. Results The prevalence of overweight and obesity was 15.23%, 18.55% and 11.84% in total, male and female ninth grade students respectively. The multiple Logistic regression analysis indicated that the risk factors between boys and girls were significantly different. The main factors affecting boys obesity rate were one-child, boarding, both parents obesity, taking health education courses, having indoor stadium and screen time. Meanwhile, for girls the factors were boarding, both parents obesity and sports time. Conclusions Schools should arrange the schedule of boarding students and offer health education courses based on the characteristics of boys and girls. Meanwhile schools should unite parents to control adolescents’ screen time and nutrition balance, which is benefit for preventing adolescents overweight and obesity.

Effect of Metapex paste on root cancal therapy of deciduous teeth:a Meta-analysis / 预防医学

Objective To evaluate the effect of Metapex for root canal therapy of deciduous teeth. Methods Based on the key words"Metapex paste" and"Root canal therapy of deciduous teeth" , the Chinese database, such as China national knowledge infrastructure, Wanfang database and Weipu database were retrieved. Based on the key words"Metapex" and"deciduous teeth" , the English databases such as PubMed and Medline were retrieved. Collecting random controlled trials about Metapex paste with root canal therapy of deciduous teeth from the beginning of their establishment to August 2017. Do Meta analysis using Rev Man 5.3 software for homogeneous studies, calculating risk ratio (RR) and 95％ confidence interval (CI) . Results Twelve studies were included. Meta analysis showed that Metapex was more effective in root canal therapy of deciduous teeth compared with zinc oxide eugenol iodoform paste after 1 year (RR=1.11, 95％ CI: 1.01-1.22); The clinical effectiveness of Metapex paste was better than calcium hydroxide after 6 months and 1 year (RR6 mouths=1.06, 95％ CI: 1.03-1.09; RR1 year=0.17, 95％ CI: 1.03-1.10); There was no obvious difference between Metapex and ZOE after 6 months (RR=1.13, 95％ CI:1.00-1.27) . Conclusion Metapex paste can improve the success rate on root canal therapy of deciduous teeth , is a more ideal root canal filling material of deciduous teeth .

Detection of matrix metalloproteinase-11 in menstrual blood by enhanced chemiluminescence method / 法医学杂志

OBJECTIVE@#To explore the forensic application value of detection of matrix metalloproteinase-11 (MMP-11) in menstrual blood by enhanced chemiluminescence method.@*METHODS@#Menstrual blood, vaginal swab, peripheral blood, saliva stain, urine stain and semen stain were collected to detect whether or not there were MMP-11 using enhanced chemiluminescence method. The specificity and reliability of the MMP-11 assay along with its sensitivity were evaluated.@*RESULTS@#The positive detection rate of MMP-11 in menstrual blood was 89.47%, whereas no MMP-11 was found in vaginal swab, peripheral blood, saliva stain, urine stain and semen stain. When 25 microL sample was added, the mass concentration of protein was 1.329 microg/microL, then MMP-11 could be detected. A positive detection rate of 89.58% was observed in MMP-11 positive menstrual blood samples after stored at 4 degrees C for 20 months.@*CONCLUSION@#Enhanced chemiluminescence method is sensitive and specific for detecting MMP-11, and can be applied to distinguish menstrual blood from common stain such as peripheral blood, vaginal fluid.

Application of ITO method and discriminant functions in full sibling and half sibling identification / 法医学杂志

OBJECTIVE@#To investigate the application of ITO method and discriminant functions method in full sibling and half sibling identification.@*METHODS@#Five hundred pairs of full siblings (FS), 50 pairs of half siblings (HS) and 500 pairs of unrelated individuals (UR) were genotyped by PowerPlex 16 system. Full sibling index (FSI), half sibling index (HSI) and the FSI:HSI ratio were calculated with ITO method. Allelic matching of each pair of the three groups was compared. The locus numbers of no-allele sharing (x0), half-allele sharing (x1) and two-alleles sharing (x2) were calculated, respectively. The discriminant functions about full-siblings, half-siblings and unrelated individuals (UR) were established by SPSS 13.0 statistical software.@*RESULTS@#(1) Regard FSI > or = 19 or FSI < 1 as the standard of distinguishing full sibling from unrelated individual, the alternate correct percentage was 96.4%. Regard HSI > or = 19 or HSI < 1 as the standard of distinguishing half sibling from unrelated individual, the alternate correct percentage was 85.3%. Regard FSI:HSI > or = 1 or FSI:HSI < 1 as the standard of distinguishing full sibling from half sibling, the alternate correct percentage was 87.5%. (2) Four groups of discriminant functions were established. The alternate correct percentage of these discriminant functions were 84.4%-97.7%, with the highest one in full sibship-unrelated individual group.@*CONCLUSION@#Both ITO method and discriminant functions method are efficient in identification of full sibling or half sibling.

Species identification of biomaterials by amplifying 12S rRNA gene / 法医学杂志

OBJECTIVE@#To establish an accurate, simple, quick, specific and sensitive method for species identification by amplifying 12S rRNA gene with the same reaction system.@*METHODS@#Based on the downloaded 12S rRNA gene sequences of eleven species (human, chicken, duck, goose, pig, rabbit, rat, sheep, bull, dog and goat) from GenBank, a pair of universal primers to eleven species and three pairs of specific primers to human, chicken and duck were designed. The amplicons amplified with universal primers were used for internal controls, and the amplicons amplified with specific primers were used as identification of human, chicken and duck. DNA was extracted from various samples including blood stains, fresh or freezing muscles, heat-treated muscles and hairs. Both single DNA of human, chicken or duck and mixed DNA of any two kinds of them were amplified.@*RESULTS@#The lengths of universal amplicons were about 400 bp. The lengths of specific amplicons were 163 bp for human, 286 bp for chicken, and 374 bp for duck, respectively. No cross amplification was observed, indicating a high specificity of the specific primers. The identification rate was 100% for human, 99% for chicken, and 100% for duck, respectively. The detection sensitivity ranged from 2.5 pg to 200 pg of DNA concentration depending on species, even in mixtures of different species DNA without interference.@*CONCLUSION@#The method established could identify different species under the same reaction system.

Detection of MMP-11 from menstrual blood using immunohistochemistry / 法医学杂志

OBJECTIVE@#To prove the feasibility of detecting menstrual blood as well as its cellular localization with rabbit-anti-human matrix metalloproteinase-11 (MMP-11) polyclonal antibody.@*METHODS@#MMP-11 in menstrual blood, peripheral blood, vaginal liquid, aged menstrual bloodstain, and endometrium sections were assayed with SAP immunohistochemistry.@*RESULTS@#MMP-11 was found only in menstrual samples within stroma and epithelium cells.@*CONCLUSION@#MMP-11 polyclonal antibody may be applied in the distinction between menstrual blood and venous blood.

Comparation on Haversian system between human and animal bones by imaging analysis / 法医学杂志

OBJECTIVE@#To explore the differences in Haversian system between human and animal bones through imaging analysis and morphology description.@*METHODS@#Thirty-five slices grinding from human being as well as dog, pig, cow and sheep bones were observed to compare their structure, then were analysed with the researchful microscope.@*RESULTS@#Plexiform bone or oeston band was not found in human bones; There were significant differences in the shape, size, location, density of Haversian system, between human and animal bones. The amount of Haversian lamella and diameter of central canal in human were the biggest; Significant differences in the central canal diameter and total area percentage between human and animal bones were shown by imaging analysis.@*CONCLUSION@#(1) Plexiform bone and osteon band could be the exclusive index in human bone; (2) There were significant differences in the structure of Haversian system between human and animal bones; (3) The percentage of central canals total area was valuable in species identification through imaging analysis.