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.

Objective:To investigate the effect of Shentai Tea Polyphenols on memory and its underlying mechanism in healthy elderly adults.Methods:According to the randomized, double blind and placebo-controlled prospective experimental design, 240 healthy middle-aged or elderly subjects with normal objective cognition were recruited in our hospital from April to December 2019 through advertising, and they were randomly divided into an experimental group ( n=120) and a control group ( n=120). Oral administration of Shentai Tea Polyphenols or placebo capsules (lasting for 90 d, 2 times/d, 2 capsules/time) was given to subjects in the two groups. The neuropsychological scale scores and near-infrared brain imaging data of all subjects were collected before and after intervention, and the mean time from baseline data collection before intervention to follow-up data collection after medication was controlled within 6 months. Results:In patients from the experimental group, as compared with those before intervention, scores of delayed recall and recognition memory in the auditory verbal learning test (Huashan version) and Boston naming test, scores of Montreal cognitive assessment scale (basis version) were significantly higher, and scores of Hamilton anxiety scale, shape trails test A and rapid-eye-movement sleep behavior disorder screening questionnaire were significantly lower after intervention ( P<0.05); however, only scores of delayed recall in the auditory verbal learning test (Huashan version) were significantly increased in the control group ( P<0.05). A total of 23 pairs of differences of brain function connection before and after intervention in the experimental group were significantly higher than those in the control group ( P<0.05), mainly involving the function connection of forehead peak network (FPN), and function connection of FPN-default network, function connection of FPN-somatosensory movement network, function connection of FPN-dorsal attention network and function connection of FPN-visual network, as well as the function connection of default network and somatosensory movement network. Conclusion:Shentai Tea Polyphenols can improve cognitive performances including memory, language and executive function, anxiety mood and sleep quality in healthy middle aged or elderly subjects by affecting the functional connections of the networks in the brain.

Adipose tissue is a promising target for treating obesity and metabolic diseases. However, pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient vascularization, especially in obese subjects. We have previously shown that during cold exposure, connexin43 (Cx43) gap junctions are induced and activated to connect neighboring adipocytes to share limited sympathetic neuronal input amongst multiple cells. We reason the same mechanism may be leveraged to improve the efficacy of various pharmacological agents that target adipose tissue. Using an adipose tissue-specific Cx43 overexpression mouse model, we demonstrate effectiveness in connecting adipocytes to augment metabolic efficacy of the β ₃-adrenergic receptor agonist Mirabegron and FGF21. Additionally, combing those molecules with the Cx43 gap junction channel activator danegaptide shows a similar enhanced efficacy. In light of these findings, we propose a model in which connecting adipocytes via Cx43 gap junction channels primes adipose tissue to pharmacological agents designed to engage it. Thus, Cx43 gap junction activators hold great potential for combination with additional agents targeting adipose tissue.