ABSTRACT
Objective To study stress distributions of lower dentition distally moved with miniscrews in external oblique line area when the traction hooks with different lengths were placed at different positions by the three-dimensional (3D) finite element method. Methods Based on cone beam computed tomography (CBCT) data from a patient, traction hooks with the heights of 2 mm and 7 mm were constructed and fixed between the lateral incisors and the canine brackets, as well as between the canines and the first premolar brackets. Four kinds of 3D finite element models of full dentition distally moved with miniscrews were constructed. The 3 N traction force was loaded between the traction hook and the miniscrews. The maximum von Mises stress and initial displacement of the mandibular teeth and dentition under four working conditions were analyzed. ResultsWhen the traction hook with 7 mm-height was placed between the lateral incisor and the canine, the lower central incisor rotated clockwisely, with the crown moving labially and the root moving lingually. But under the other three working conditions, the central incisor rotated counterclockwisely, and the crown and root moved lingually. When the traction hook with 7 mm-height was placed between the canine and the first premolar, the lower canine crown moved proximally. But under the other three working conditions, both the crown and root moved distally. Under four working conditions, the mandibular molars all rotated counterclockwisely,with the crown and root moving distally. Conclusions Through 3D finite element analysis, biomechanical mechanism of the effect of different traction hooks on mandibular tooth movement during distalization of the lower dentition was elucidated.With full understanding of the biomechanical mechanism, proper selection for length and placement of the traction hook can achieve distal movement of the entire mandibular dentition more efficiently.
ABSTRACT
Objective @#To evaluate the immune effects of inactivated H7N9 influenza vaccine.@*Methods @#We searched several common databases（The Cochrane Library,PubMed,China Biology Medicine disc,China National Knowledge Infrastructure,etc.）for research articles about immune effects of H7N9 influenza vaccine published from the time the database built to July 10th of 2018,using H7N9 and vaccine as keywords. After screening the articles according to the inclusion and exclusion criteria,we assessed the quality of the studies and then employed seroconversion rate（SCR）as an outcome indicator to analyze the immune effects of different doses and adjuvants.@*Results @#We recruited 5 articles on inactivated H7N9 influenza vaccine from 1 679 articles. The sample size was 2 579. The results of the meta-analysis showed that the rate difference（RD）values of SCR in each dose group after the first dose ranged from 1% to 10%,which indicated a poor protective effect;after the second dose of immunization,the RD values of SCR in the vaccines without adjuvants ranged from 13% to 19%,which was not effective enough;the RD values of SCR in the vaccines with adjuvants ranged from 62% to 69%,which met the licensing criteria for influenza vaccine;better results could be achieved when immunized with two doses of vaccines with adjuvants（ RR=1.19,95%CI：1.02-1.39）;vaccines with AS03 or MF59 at the lowest dose of 3.75 μg had the same immune effects as ones at a dose of 15 μg;vaccines with AS03（RD=89%,95%CI：85%-93%）were superior to those with MF59（RD=42%,95%CI：9%- 75%）.@*Conclusion @#Inactivated H7N9 influenza vaccines could achieve good immune effects when inoculated two doses with adjuvants,and the minimum effective dose was 3.75 μg.
ABSTRACT
This article was aimed to study the distribution and effects of apolipoprotein E (ApoE) gene polymorphism of different constitutional types among coronary heart disease (CHD) patients with blood stasis syndrome on vascular endothelial cell (VEC) function. The whole gene sequencing method was used to identify genotypes of ApoE gene among 556 CHD patients with blood stasis syndrome, in order to analyze the relationship between polymorphism of ApoE gene and the level of VEC function. The results showed that the frequency of E3/3 genotype of each physical group was significantly lower than that of the healthy group; and the frequency of E3/4 genotype was significantly higher than that of the healthy group. In addition, the frequency of E3/3 genotype in qi deficiency constitution group was higher than that of blood stasis constitution group and yang deficiency constitution group; but the frequency of E3/4 genotype in blood stasis constitution group and yang deficiency constitution group was higher than that of the qi deficiency constitution group. The levels of ET and ET/NO in each of genotype groups of blood stasis constitution, yang deficiency constitution, qi deficiency constitution of CHD patients with blood stasis syndrome were higher than that of the healthy group (P < 0.05). In the genotype group of blood stasis constitution of CHD patients with blood stasis syndrome, the frequency of E3/4+E4/4 genotype ET was higher than that of other genotypes (P < 0.01). The levels of ET, NO, ET/NO in genotype groups of yang deficiency constitution and qi deficiency constitution of CHD patients with blood stasis syndrome were not significantly different. It was concluded that ApoE genotype E3/4, E3/3 may be the susceptible genotypes of blood stasis syndrome in CHD. There is a certain difference among different constitutional types. CHD with blood stasis syndrome patients, who are the constitution of blood stasis, carrying the ApoE gene polymorphism of E4 allele may have the function of increasing the ET level.
ABSTRACT
Objective To study the distribution of body constitutions of CHD patients with blood stasis syndrome;To explore the relationship between different body constitutions and their blood lipid levels.Methods WANG’s Constitutional Classification was used to diagnose body constitutions of 600 CHD patients with blood stasis syndrome, and analyze the relationship between the different body constitutions and triglyceride (TG) level, low density cholesterol (LDL-C) level, high density cholesterol (HDL-C) level.Results The four most common body constitutions of CHD patients with blood stasis syndrome in Taiyuan area were the constitutions of blood stasis, yang deficiency, qi deficiency and yin deficiency. The TG levels of the four body constitutions were higher than those of healthy people (P0.05).Conclusion There is a certain difference among the blood lipid levels in different body constitutions of CHD patients with blood stasis syndrome, and the patients of blood stasis syndrome with high LDL-C level are more dangerous than patients with other body costitutions.