Objective: To study the mechanism of effect of total flavone of rhizoma drynariae in groups with different dosage on osteoblasts cultured in vitro. Methods: To culture osteoblasts with UMA-106-01 osteoblast strain and to observe the activity of ALP and the endosmosis of 3H-TdR. Results: The total flavone of rhizoma drynariae increased the activity of ALP in cells cultured with UMR-106-01 strain. The ALP activities correspondingly changed in the 24h, 48h and 72h, which related to dosage effect and time effect. Among them, the activity in the 48h is the most ideal one. And the amount of endosmosis of the total flavone of rhizoma drynariae to 3H-TdR increased more remarkably in the 48h than that in the 24h and it also related to the time effect. Conclusion: The total flavone of rhizoma drynariae can promote the differentiation and multiplication of osteoblasts.

Objective To evaluate and analyze the effect of treatment on fractures of the clavicle with reconstruction plate or with Kirschner wire.Methods Of 56 clavicular fracture cases for treatment with surgical procedures,22 cases were fixated with reconstruction plate.34 cases were fixated with Kirschner wire.Results All 56 cases were followed up for 10~48 months,on average 21 months.Reconstruction plate fixation group:2 cases concomitant with delayed fracture healing were multiple trauma patients.The mean union time in this group was 3.6 months(range from 3 to 5 months).Kirschner wire fixation group:3 cases with wires migration.The mean union time in this group was 2.3 months(range from 2 to 3 months).According to Kalarsson's shoulder function evaluating criteria,all cases were excellent.Conclusion Surgical technique with Kirschner wire is simple and credible treatment for clavicular uncomminuted fractures.,it complys with the conception of minimally invasive technique and is a recommendable way.

AIM: To explore the role of phosphatidylinositiol 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling pathways in the inhibitory effects of puerarin on oxidized low-density lipoprotein (ox-LDL)-induced tissue factor (TF) expression in vascular endothelial cells.METHODS: The mRNA expression of TF was detected by real-time fluorescent quantitative PCR.The protein levels of TF and Akt was determined by Western blot.The content of the nitric oxide (NO) was measured by nitrate reduction method.RESULTS: Compared with control group, incubating endothelial cells with ox-LDL significantly induced TF expression at mRNA and protein levels and the dephosphorylation of Akt protein, and decreased NO production.Incubation of the endothelial cells with puerarin for 1 h and then treatment of the cells with ox-LDL decreased the TF expression at mRNA and protein levels, increased Akt protein phosphorylation and intracellular NO content.Co-incubation of the endothelial cells with PI3K inhibitor LY294002 and puerarin for 1 h and then treatment of the cells with ox-LDL augmented the TF expression at mRNA and protein levels and the Akt protein dephosphorylation, and decreased NO production.Co-incubation of the endothelial cells with eNOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME) and puerarin significantly decreased the inhibitory effect of puerarin on ox-LDL-induced TF expression at mRNA and protein levels in the endothelial cells, and reduced Akt protein phosphorylation and NO production.CONCLUSION: Puerarin inhibits ox-LDL-induced TF expression at mRNA and protein levels in the human umbilical vein endothelial cells via activation of PI3K/Akt/eNOS signaling pathway.

Objective To evaluate the condition of oxidative stress and immunosuppression in early stage of severe sepsis,and investigate the correlation between them. Methods A prospective random control study in-cluded patients group(n=51)and control group(n=31). The concentration of serum superoxide dismutase was measured by enzyme linked immunosorbent assay(ELISA),CD4+CD25+Treg% was measured by flow cytometry , respectively. The difference between two groups was compared and the correlation between parameters in patients group was evaluated. Results The concentration of serum SOD was lower than control group (P < 0.01). CD4+CD25+Treg% significantly high,compared to the control group(P < 0.01). There was no strong correlation be-tween parameters in patients group. Conclusion Oxidative stress and immunosuppression are exist in the early stage of severe sepsis.

Objective　To understand the impact of early and timely treatment and initial antiviral treatment regimen on mortality and attrition of antiretroviral therapy. Methods A retrospective cohort study was conducted using download data on antiretroviral therapy for HIV-infected patients in Liuzhou City, Guangxi Province, from the database of the Basic Information System for AIDS Control and Prevention (BISAC) from 2010 to 2020. The Cox proportional risk regression model was used to analyze the influencing factors of mortality and attrition. Results A total of 15 713 infected patients were included, including 53.4% aged 18-<50 years, 69.4% male, 61.0% farmer, 75.1% CD4 count <350 cells /μL before initial antiviral treatment, the overall mortality rate was 4.30/100 person-years, and the overall attrition was 2.42/100 person-years. The results of Cox regression analysis showed that the influencing factors of mortality were pretreatment CD4 counts of 350-<500 cells/μL(AHR=0.72, 95%CI: 0.63-0.81) and ≥500 cells/μL (AHR= 0.64, 95%CI: 0.55-0.76); duration from diagnosis to initial antiviral treatment 91-180 days (AHR=1.25, 95%CI: 1.08-1.45), 181-365 days (AHR=1.26, 95%CI: 1.08-1.47), and ≥365 days (AHR=1.26, 95%CI: 1.11-1.44); initial antiviral treatment regimens of D4T+3TC+EFV/NVP (AHR=1.47, 95%CI: 1.32-1.63) and AZT/D4T/TDF+3TC+LPV/r (AHR=1.73, 95%CI: 1.50-1.99). Factors affecting attrition were pretreatment CD4 counts of 350-499 cells/μL (AHR=1.32, 95%CI: 1.16-1.50) and ≥500 cells/μL (AHR=1.28, 95%CI: 1.10-1.50); interval from HIV positivity confirmation to initial dosing ≥365 days (AHR=1.21, 95%CI: 1.04-1.40), initial antiviral treatment regimens of TDF+3TC+NVP (AHR=1.32, 95%CI: 1.13-1.55), AZT+3TC+EFV/NVP (AHR=1.43, 95%CI: 1.26-1.62) and AZT/D4T/TDF+3TC+LPV/r (AHR=1.33, 95CI%: 1.06-1.67). Conclusions　Early and timely treatment and the initial antiviral treatment regimen of TDF+3TC+EFV have good efficacy, but attention should be paid to the high risk of attrition of HIV-infected people with high CD4 count before treatment.

As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.
Biomechanical Phenomena ; Bite Force ; Humans ; Mastication ; Molar

Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.

Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
Bite Force ; Ceramics ; Crowns ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Molar ; Prostheses and Implants ; Stress, Mechanical