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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.
Subject(s)
Composite Resins , Dental Bonding , Dental Cements , Surface Properties , Resin Cements , Dentin-Bonding Agents , Dentin , Materials Testing , Microscopy, Electron, ScanningABSTRACT
Objective To identify the eye movement characteristics that can distinguish reading interest and comprehensibilityin order to provide reference for prediction of reading interest and comprehensibility based on eye movement.Methods Tobii Glasses 3 was used to collect eye tracking data from 11 participants who read 12 texts on different topics.After reading all the texts,the participants marked each sentence with theirlevels of interest and comprehensibility.Then,Python R and excel software were used to preprocess and analyze the data,and the differences in eye movementamid the four combinations of reading interest(interested or not)and comprehensibility(levels of difficulty)were studiedat overall and individual levels.Results At the overall level,there were statistically significant differences in eye movement between the easy comprehension group and the difficult comprehensiongroup where interest was concerned,but there was little difference between the interested group and the disinterested groupwhen it came to comprehensibility.There were differences in eye movement behavior between individuals,and some of the statistically significant differences in eye movement were consistent across most of the participants.In addition,some of the eye movement characteristicswere oppositeacross different individuals or could not distinguish between the interested and disinterested at the overall level,but could be distinguished within individuals.Conclusion At the overall level,it is relatively easy to determine comprehensibility through eye movement,but it is more difficult to distinguish whether the participant is interested in the sentence or not,especially when the text is easily comprehensible.At the individual level,eye movement behavior varies widely between individuals,and individuals manifest different characteristics in distinguishing reading interest and comprehensibility.
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Objective:To explore the incidence and severity of esophageal clearance impairment in stroke survivors with dysphagia, the clinical characteristics of patients with abnormal esophageal clearance, and their relationship with swallowing physiology, penetration and aspiration.Methods:Clinical data were collected describing 174 stroke survivors whose swallowing had been studied videofluoroscopically. In each selected case there was a good anterior-posterior view of esophageal clearance. Their anterior-posterior and lateral imaging results while swallowing 5ml of high-consistency food were analyzed. The esophageal clearance item of the modified barium swallow impairment profile was then used to rate each subject′s esophageal clearance and each physiological component of swallowing in the oral and pharyngeal phases. The Rosenbek penetration aspiration scale was employed evaluate the safety of their swallowing.Results:Seventy of the patients (40.2%) displayed abnormal esophageal clearance, and more than half of the 70 (43 patients, 24.7%) showed mid- to distal esophageal retention. Those with abnormal esophageal clearance had a higher average age and more severe overall impairment in the pharyngeal phase of swallowing. Esophageal clearance was not, however, significantly correlated with swallowing physiology in the oral phase or with penetration or aspiration grade. There were, however, significant positive correlations with laryngeal elevation, anterior hyoid excursion, pharyngeal stripping waves, pharynx contraction, upper esophageal sphincter opening, tongue base retraction and pharyx residue.Conclusion:Stroke survivors with dysphagia may display abnormal esophageal clearance. The risk is closely related to age and the severity of the dysphagia. Abnormal physiology during the pharyngeal phase of swallowing and reduced pharyngeal stripping may predict abnormal esophageal clearance. Swallowing assessment can be made more comprehensiveness and systematic by incorporating anterior-posterior videography in routine barium swallowing studies.
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Epilepsy is a complex neurological disease and its pathogenesis has not yet been clear. More and more evidence shows that epilepsy is closely related to epigenetic mechanisms such as histone deacetylation. Histone deacetylase inhibitors, a kind of epilepsy targeting drug potentially, are involved in the protection of neurogenesis and the regulation of a variety of neural signal cascade reactions. This article reviews the research progress of histone deacetylation in the pathogenesis of epilepsy and application prospect of histone deacetylase inhibitors in treating epilepsy.
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Objective:To investigate the correlation between intraplaque hemorrhage (IPH) and new-onset embolic cerebral infarction after basilar artery angioplasty or stenting.Methods:Consecutive patients with severe basilar atherosclerotic stenosis underwent basilar artery angioplasty or stenting in the Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine from January 2015 to February 2022 were retrospectively enrolled. High resolution magnetic resonance vessel wall imaging (HRMR-VWI) and diffusion-weighted imaging (DWI) were performed within one week before procedure, and brain DWI or CT examination was performed within 72 h after procedure to determine the patients with new-onset embolic cerebral infarction.Results:A total of 32 patients were enrolled in the analyze. IPH existed in 10 patients with basilar artery culprit plaque, and 5 had new-onset embolic cerebral infarction after procedure. The incidence of embolic cerebral infarction in the IPH group was significantly higher than that in the non-IPH group (50% vs. 0%; P=0.001). The proportion of patients with IPH in the embolic cerebral infarction group was significantly higher than that in the non-embolic cerebral infarction group (100% vs. 18.5%; P=0.001). Conclusion:IPH may be associated with new-onset embolic cerebral infarction after basilar artery angioplasty or stenting.
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Objective:To explore the effect of swallowing different viscosities and volumes on the swallowing of dysphagic stroke survivors, and also penetration and aspiration.Methods:A total of 59 stroke survivors with dysphagia were evaluated using videofluoroscopy while completing the Chinese version of the volume viscosity swallow test. They were required to swallow 3, 5 and 10ml of food of medium, low, zero and high viscosity. Modified barium swallowing impairment profiles (MBSImPs) and the Rosenbek penetration aspiration scale were used for quantitative analysis.Results:Tongue control, initiation of the pharyngeal swallow and larynx closure showed the worst performance when swallowing zero-viscosity food. Oral residue performance was poor when swallowing large volumes and pharyngeal peristalsis was poor with small volumes. The risk of penetration and aspiration was greater with low-viscosity, large-volume swallowing tasks. There was a significant positive correlation between the penetration aspiration grade and total pharyngeal score. Larynx closure was especially strongly correlated with the penetration aspiration grade.Conclusions:The characteristics of physiological swallowing are closely related to the viscosity and volume of the material being swallowed. The risk of penetration and aspiration is greater with large volumes of low-viscosity food.