BACKGROUND:Biomechanical compatibility is the necessary condition to ensure the stable osseointegration with implants that then can function over a long period; therefore, it is especialy important to get knowledge about distribution of stress and strain between the maxilary central incisor and its surrounding bone tissue. OBJECTIVE: Based on five different anatomical types of natural teeth, to study the regularity of stress distribution between the maxilary central incisor root and implant.METHODS: According to the five different anatomical types of natural maxilary central incisors, UGNX and ANSYS were used to set up three-dimensional finite element models (B1, B2, M1, M2, P1) for the implant and surrounding structures, which were under 100 N static load at angles of 0o, 30o, 45o, 60o, 90o with the long axis of teeth. Then, the stress distribution between the five kinds of maxilary central incisor roots and implants was analyzed. RESULTS AND CONCLUSION:Among the five different anatomical types, the equivalent stress for both the natural central incisor and implant were increased with the increasing of angles, and the implant had a higher raising trend. The equivalent stress for the natural tooth concentrated upon B1 for the maximum value and M1 for the minimum value; while the equivalent stress for the implant focused on the maximum value at M1 and the minimum value at M2. There was a gap of 2%-31% between the equivalent stresses for the natural tooth roots and a gap of 4%-21% for the implants. The stress distribution range for the implant was just smaler than that for the natural tooth roots. It implies that the bit force of implant and natural tooth is in positive proportion to the bite angles, and the bite force that implant can burden is smaler than that the central incisor can.

Besides the catalytic domain, some xylanases contained a non-catalytic domain which is named as carbohydrate binding module (CBM). CBM can be used to improve their binding-ability to insoluble substrates. We illustrated the importance of CBM by reviewing the source of CBMs, type of families, features of binding to insoluble substrates, specific amino acids involved in substrate-binding, linker peptides connecting the catalytic domain, and the effect of CBMs on xylanase thermostability. CBM is important for xylanase to break down complicate carbohydrates. Perspectives on engineering xylanase activity according to the characteristics of CBMs were given.
Binding Sites ; Carbohydrate Metabolism ; Catalysis ; Endo-1,4-beta Xylanases ; metabolism ; Multienzyme Complexes ; chemistry ; Substrate Specificity

ObjectiveTo explore the effect of exercise on the postural control and muscular function around the ankle in patients with functional ankle instability (FAI) with meta-analysis. MethodsRandomized controlled trials about therapeutic exercise for FAI published before December, 2021 were searched from PubMed, EBSCO, SPORTdiscus, Medline, Science Direct, Springlink, Web of Science, Embase CNKI, VIP and Wanfang Data. The quality and evidence grades of the researches were evaluated by two researchers, and the outcomes were analyzed with RevMan 5.4. ResultsFourteen randomized controlled trials were finally included, involving 434 subjects. Compared with no exercise intervention, therapeutic exercise might significantly improve the movement of center of pressure whether with eye-open or eye-closed (eye-open, SMD = -0.28, 95%CI -0.46 to -0.09, P = 0.003; eye-closed, SMD = -0.24, 95%CI -0.40 to -0.09, P = 0.001); while therapeutic exercise might also enhance the activation of the peroneus longus before dynamic task (SMD = 0.38, 95%CI 0.05 to 0.71, P = 0.03), and activation of the peroneus longus (SMD = 0.53, 95%CI 0.16 to 0.90, P = 0.005) and tibialis anterior (SMD = 0.47, 95%CI 0.10 to 0.84, P = 0.01) after dynamic task. There was neither significant difference in the activation of the tibialis anterior (SMD = 0.48, 95%CI -0.14 to 1.11, P = 0.13), nor the peak torque ratio of eversion to inversion isokinetic strength (SMD = -0.15, 95%CI -0.46 to 0.16, P = 0.340) before dynamic task between the two groups. ConclusionTherapeutic exercise can decrease movement of center of pressure, enable anticipatory contraction of peroneus longus before dynamic tasks and compensatory contraction of peroneus longus and tibialis anterior after tasks, to make it easier to deal with external interference, maintain articular stability and prevent re-injury.

ObjectiveTo systematically analyze the effect of therapeutic exercise on neck function and quality of life in patients with neck pain and forward head posture. MethodsRandomized controlled trials about the effects of exercise training on forward head posture and neck pain were searched from PubMed, Web of science, Embase, Medline, Science Direct, EBSCO, Springlink, CNKI, VIP, and Wanfang Data from database establishment to April, 2022. The literature was screened by two researchers independently. Cochrane bias risk assessment tool and Physiotherapy Evidence Database Scale were used to evaluate the quality of the included articles. Revman 5.4 software was used for meta-analysis. ResultsA total of 416 patients from eleven literatures were included. Level 1a evidence indicated scapula stability training could effectively improve cranial vertebral angle (MD = 3.62, 95%CI 2.41 to 4.83, P < 0.001), and relieve pain (MD = 1.32, 95%CI 0.18 to 2.46, P = 0.02). Level 1b evidence indicated scapula stability training could reduce functional disability (MD = -0.92, 95%CI -1.11 to -0.74, P < 0.001). Level 1b evidence indicated deep cervical flexor training could improve cranial vertebral angle (MD = -0.83, 95%CI -1.56 to -0.10, P = 0.03), relieve pain (MD = 0.93, 95%CI 0.54 to 1.32, P < 0.001), and improve neck functional disability (MD = 2.17, 95%CI 1.39 to 2.95, P < 0.001). ConclusionScapula stability training and deep cervical flexor training can effectively improve cranial vertebral angle, relieve neck pain, and improve neck function.

Objective: To investigate the effects of human adult T lymphoblastic leukemia virus typeⅠ (HTLV-1) infection on the production of reactive oxygen species (ROS) and mitochondrial damage in host cells. Methods: A cell model of HTLV-1 infection was established by co-culturing HTLV-1-positive cell line MT2 with HeLa cells. ROS, mitochondrial membrane potential (MMP) and total mitochondria were detected using specific fluorescence probe labeling method. Cell apoptosis was detected by Annexin V-FITC/PI method. Western blot was performed to detect viral proteins Tax and p19, as well as mitochondrial proteins TIM23 and TOM20. After the treatment of MT2 cells with different concentrations of reverse transcription inhibitors (ZDV), relative viral loads were detected by quantitative real-time PCR and Western blot, and the mass of mitochondria was analyzed by flow cytometry. Results: After co-culturing HeLa cells with MT2 cells for 24 h, the ROS level in host cells increased without obvious cell apoptosis, while the mitochondrial membrane potential, mitochondrial protein expression and total mitochondria decreased significantly. When the replication of HTLV-1 in MT2 cells was inhibited by ZDV, the ROS level and total mitochondria increased. Conclusions HTLV-1 infection can cause oxidative stress in host cells, resulting in mitochondrial damage. Autophagy might be activated to degrade mitochondrial damage and maintain cell homeostasis during the infection.