Objective:To evaluate the influence of the implant-supported porcelain bridges made from non-precious metals using spark erosion techniques, and to discuss the feasibility and details of making the implant restoration by spark erosion technique.Methods: The study included 12 patients ( 9 males and 3 females) with 92 units implant-supported non-precious porcelain bridge from Sep.2011 to Feb. 2013.All the patients received implant treatment in Department of Oral Implantology, Peking University School and Hospital of Stomatology.The total of 52 implants, were from Nobel Biocare implant system, Camlog implant system and Ankylos implant system.The implant analogs were connected in sequence with a copper wire to guarantee conductivity.The implant electrodes represented one electrode and the superstructure the other.During spark-erosion machining, the cast holding the implant electrodes and the prosthetic framework were moved toward one another, causing an electrical erosion of the protruding ele-ments.Results:After the spark-erosion machining, the minimum gap between the framework and abut-ment was 0.21 mm, which was two units bridge.The maximum was 2.59 mm, which was 11 units bridge with 6 implants.The average gap was 0.68 mm.After the spark-erosion machining, the bridge fitted well with the passive position stability.Conclusion: The method of making implant-supported non-precious porcelain bridge reduces costs on patients.Spark erosion has the potential to provide implant framework with an excellent fit.The patients are satisfied with the clinical results.

Objective To measure the angular velocity and perpendicular ground reaction force of the ankle joint under different heights with half-squat jumping in parachute training simulation,providing a reliable experiment basis for the preventing of ankle injury.Methods A total of 18 volunteers participated in this study.The experimental group included 9 male with experience of parachute landing,while the other 9 male without experience of parachute landing were assigned to the control group.Each subject was instructed to jump off a platform with a height of 30 cm and 60 cm and land on a hard surface in a half-squat posture.The dynamic landing process was recorded with a high speed camera and the biomechanical data was collected and analyzed,including perpendicular ground reaction force,angular displacement,velocity and acting time.Results From 30 cm's height,the ankle angular displacement of the control group was significantly larger than the experimental group (25.73°± 8.13° vs 20.05°± 12.27°,P ＜ 0.05).The perpendicular ground reaction force of the control group was significantly smaller than the experimental group (3 372.4±748.6 N vs 5 181.5±1 726.2 N,P ＜ 0.05).The acting time of the control group was significantly longer than the ex perimental group (0.049±0.015 s vs 0.012±0.004 s,P ＜ 0.05).The buffer time of the control group was significantly shorter than the experimental group (1.397±0.746 s vs 1.737±0.451 s,P ＜ 0.05).From 60 cm's height,the ankle angular velocity of the control group was significantly higher than the experimental group (25.45± 15.01 °/s vs 16.51 ±4.18 °/s,P ＜ 0.05).The perpendicular ground reaction force of the control group was significantly smaller than the experimental group (4 616.0±1 124.7 N vs 7 119.5±2 307.4 N,P ＜ 0.05).The acting time of the control group was significantly longer than the experimental group (0.048±0.013 s vs 0.015±0.006 s,P ＜ 0.05).The buffer time of the control group was significantly shorter than the experimental group (0.922±0.347 s vs 1.617±0.547 s,P ＜ 0.05).Conclusion Jumping from different heights,the experinental group was larger in perpendicular ground reaction force but smaller in the angular velocity and displacement than the control group.There was a shorter acting time and a longer buffer time in the experimental group than the control group.

Based on the reported inhibitors TH287, 17 five-membered heterocyclopyrimidine derivatives were designed and synthesized by cyclization, scaffold hopping, bioisosterism and molecular docking technology. The bioassays determined by malachite green method demonstrated that the target compounds displayed good inhibitory activity against MTH1. Among them, the IC50 value of 7 compounds was less than 1 μmol/L, suggesting that these compounds may be candidates for further investigation.

Background Previous studies using meta-analysis to explore the relationship between air pollution exposure and ischemic stroke (IS) mostly focus on particulate matter-related themes, few include gaseous pollutants in the study, and subgroup analyses of factors such as different lag days, seasons, and genders are rarely been reported. Objective To quantitatively evaluate the relationships between short-term exposures to 6 common air pollutants, including fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃), and the incidence of IS. Methods A systematic search was conducted to collect literature studying the 6 common air pollutants and IS published up to May 1, 2022 in 6 databases (China Journal Full-text Database, China Biology Medicine Disc, PubMed, Cochrane Library, Web of Science, and Embase). Literature quality evaluation was performed using the Newcastle-Ottawa Scale. Stata 16.0 software was used to conduct meta-analysis including heterogeneity test, combined effect size, meta-regression, subgroup analysis, sensitivity analysis, and publication bias test. Results A total of 33 articles were qualified for inclusion. The total number of samples included in the literature was 7195631. The meta-analysis results showed that short-term exposures to PM_2.5 (OR=1.0082, 95%CI: 1.0049−1.0116), PM₁₀ (OR=1.0017, 95%CI: 1.0008−1.0026), CO (OR=1.0328, 95%CI: 1.0231−1.0426), NO₂ (OR=1.0150, 95%CI: 1.0079−1.0222), SO₂ (OR=1.0158, 95%CI: 1.0078-1.0238), and O₃ (OR=1.0017, 95%CI: 1.0003−1.0032) were associated with an increased risk of IS. PM₁₀ and O₃ increased the risk of IS in both lag0 and lag1, while PM_2.5, CO, NO₂, and SO₂ all showed an associated increased risk of IS only in lag0. The results of sensitivity analysis showed stable results for all pollutants studied, and there was no publication bias in the literature on the association of the remaining five pollutants with IS incidence except for the PM_2.5-related literature. Conclusion Short-term exposures to PM_2.5, PM₁₀, CO, NO₂, SO₂, and O₃ may increase the incidence of IS, with this risk showing the most significant level on the day of IS onset.