Effects of thermal cycling on bonding properties of novel low-shrinkage resin adhesive / 华西口腔医学杂志

OBJECTIVES@#The current study aimed to investigate the bonding properties of a novel low-shrinkage resin adhesive containing expanding monomer and epoxy resin monomer after thermal cycling aging treatment.@*METHODS@#Expanding monomer of 3,9-diethyl-3,9-dimethylol-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU) as an anti-shrinkage additive and unsaturated epoxy monomer of diallyl bisphenol A diglycidyl ether (DBDE) as a coupling agent were synthesized. A blend of DDTU and DBDE at a mass ratio of 1∶1, referred to as "UE", was added into the resin matrix at the mass fraction of 20% to prepare a novel low-shrinkage resin adhesive.Then, the methacrylate resin adhesive without UE was used as the blank control group, and a commercial resin adhesive system was selected as the commercial control group. Moreover, the resin-dentin bonding and micro-leakage testing specimens were prepared for the thermal cycling aging treatment. The bonding strength was tested, the fracture modes were calculated, the bonding fracture surface was observed by scanning electron microscope (SEM), and the dye penetration was used to evaluate the tooth-restoration marginal interface micro-leakage. All the data were analyzed statistically.@*RESULTS@#After aging, the dentin bonding strength of the experimental group was (19.20±1.03) MPa without a significant decrease (P>0.05), that of the blank control group was (11.22±1.48) MPa with a significant decrease (P<0.05) and that of the commercial control group was (19.16±1.68) MPa without a significant decrease (P>0.05). The interface fracture was observed as the main fracture mode in each group after thermal cycling by SEM. The fractured bonding surfaces of the experimental group often occurred on the top of the hybrid layer, whereas those of the blank and commercial control groups mostly occurred on the bottom of the hybrid layer. Micro-leakage rating counts of specimens before and after thermal cycling were as follows: the experimental group was primarily 0 grade, thereby indicating that a relatively ideal marginal sealing effect could be achieved (P>0.05); meanwhile, the blank control group was primarily 1 grade, and the penetration depth of dye significantly increased after thermal cycling (P<0.05); the commercial control group was primarily 0 grade without statistical difference before and after thermal cycling (P>0.05), while a significant difference was observed between the commercial control group and experimental group after thermal cycling (P<0.05).@*CONCLUSIONS@#The novel low-shrinkage resin adhesive containing 20%UE exhibited excellent bonding properties even after thermal cycling aging treatment, thereby showing a promising prospect for dental application.

Mid-term clinical outcome of arthroscopic surgery on early knee osteoarthritis in middle-old aged patients / 中国骨伤

OBJECTIVE@#To compare the mid-term clinical effect of arthroscopic surgery versus conservative treatment on the middle aged early knee osteoarthritis (EKOA) patients, with the hope to provide clinical evidence for their individual therapy.@*METHODS@#A total of 145 middle aged EKOA patients(182 knees) who received arthroscopic surgery or conservative treatment from January 2015 to December 2016 were retrospectively enrolled, including 35 males and 110 females, aged from 47 to 79 years old with an average of (57.6±6.9) years old, and the duration of disease ranged from 6 to 48 months with an average of(14.6±8.9) months. According to treatment method, patients were divided into arthroscopic surgery group (47 patients, 58 knees) and conservative treatment group(98 patients, 124 knees). Before treatment, patients presented with symptoms of knee joint, such as pain, swelling, locking, limited flexion and extension, and weakness, as well as abnormal findings in knee X-ray (without or suspicious joint space narrow, and a few of osteophyte formation) or in knee MRI (injury or degeneration of articular cartilage or meniscus, loose body in the joint cavity and synovial hyperemia edema, etc). Related data were collected, including duration of knee symptoms, presence of meniscus injury, loose body in the joint cavity or mechanical symptoms such as locking, and visual analogue scale (VAS) and Lysholm knee function score before treatment and at the latest follow-up. Statistical analysis was performed to compare the differences in VAS or Lyshilm score before or after treatment between the low groups and within each group.@*RESULTS@#Patients in the two groups were followed up from 60 to 76 months. In the arthroscopic surgery group, the incision healing was good and no surgical complications occurred. There were no significant differences in age, gender, BMI and follow-up time between the two groups(P>0.05). Before treatment, compared with conservative group, duration of symptoms in the arthroscopic group was longer (P<0.001), comorbidity rates of meniscus injury (P<0.001), free body (P=0.001) and mechanical symptoms (P<0.001) were higher, VAS (P<0.001) and Lysholm score (P<0.001) were worse. At the final follow-up, VAS and Lysholm score in either the conservative group or the arthroscopic group were significantly better than before treatment (P<0.05), while no significant differences between the two groups were found. The VAS was (1.5±1.2) scores in the arthroscopic group and (1.6±1.0)scores in the conservative group(P=0.549), and the Lysholm score was (84.9±12.5) scores in the arthroscopic group and (84.2±9.9) scores in the conservative group (P=0.676).@*CONCLUSION@#Both arthroscopic surgery and conservative treatment have satisfactory intermediate clinical effect middle- aged patients with EKOA, without statistically differences. However, most of the patients before surgery in the arthroscopic treatment group had mechanical locking symptoms caused by meniscus injury or loose body. Therefore, for the middle-aged EKOA patients with mechanical locking symptoms or without obtaining satisfactory outcome after conservative treatment, arthroscopic surgery may be considered.

Research progress of mitochondrial Lon protease and its related diseases / 上海交通大学学报（医学版）

Lon protease (LON) is a highly conserved ATP-dependent serine protease, which is responsible for the decomposition and elimination of abnormal proteins. As an important executor of intracellular environment stability, LON can degrade misfolded and damaged proteins together with proteasome to ensure the high quality of proteins in vivo, especially in the maintenance of mitochondrial function. At the same time, the physiological function of LON also has an important effect on cell survival under various stresses. Recent studies have shown that the abnormal expression or activity of LON is involved in the occurrence and development of many diseases such as neurodegenerative diseases, diabetes mellitus, myocardial ischemia, cerebral ischemia and tumors. This review focuses on the structure and the function of LON, the relationship between abnormal expression and diseases, and the research progress of LON activity intervention, in order to provide ideas for clinical diagnosis and treatment of related diseases.

Application and potential future directions of self-healing polymers in dentistry / 华西口腔医学杂志

Self-healing materials have rapidly developed in recent years to overcome the micro-cracks occurring in the polymer matrix. Self-healing ability offers autonomous crack repairs to prolong the service lives of polymers or polymer composites. As a main approach, extrinsic self-healing materials based on microcapsules have been applied in dentistry recently. This paper comprehensively presented and reviewed the definition and classification of self-healing materials, the synthesis of microcapsules, the calculation of self-healing efficiency, and the application of self-healing materials in dentistry. The future directions of self-healing polymers are also discussed.

Early intervention with aspirin for preventing preeclampsia in high-risk women: a meta-analysis / 南方医科大学学报

<p><b>OBJECTIVE</b>To estimate the effect of early intervention with aspirin for prevention of preeclampsia in high-risk women.</p><p><b>METHODS</b>A systematic review and meta-analysis were performed based on the principles and methods of Cochrane systematic reviews. Electronic databases were searched for randomized trials comparing aspirin with either placebo or no aspirin. Studies were included when meeting the inclusion criteria that the participants were pregnant women at a high risk of preeclampsia and started aspirin therapy at 16 gestational weeks or earlier, which were assessed by two independent reviewers. Meta-analysis was conducted using Review Manger 5.3 software.</p><p><b>RESULTS</b>A total of 5 studies involving 860 participants were included in the final analysis. In the high-risk women, early use of aspirin showed an OR of 0.35 (95% CI 0.17-0.75) for preventing pregnancy-induced hypertension (PIH), 0.75 (95% CI 0.47-0.98) for preeclampsia, 0.53 (95% CI 0.29-0.98) for intrauterine growth retardation, and 0.20 (95% CI 0.08-0.48) for preterm birth; the average birth weight in aspirin intervention group was 107.15 g (95% CI 76.13-138.18, P<0.001) more than that in the control group.</p><p><b>CONCLUSION</b>In high-risk pregnancies, early aspirin intervention starting before 16 weeks of gestation can prevent PIH, preeclampsia, IUGR, and preterm birth and help to increase the birth weight.</p>