Objective To observe the morphology of ethanol-wet dentin surfaces and detect their nano-scale adhesion force (Fad) by atomic force microscopy (AFM) in order to explore the potential mechanism of ethanol-wet bonding in improving clinical dentin bonding effectiveness.Methods Dentin slices from human premolar roots were prepared into flat ones, polished, and then randomly divided into five groups.All the specimens were acid-etched, rinsed, and left moist.They were then treated with 100％ ethanol for 0s (control group), 20s, 60s, 3×60s, or stepwise ethanol application.Afterwards, each group was scanned for the morphology in air and the Fad was probed by AFM.One-way ANOVA followed by Tukey`s test was employed for multiple comparisons using SPSS16.0.Results Compared with control group, ethanol-wet dentine produced a less undulating and relatively smooth surface topography.Ethanol-wet protocol significantly decreased the value of Fad in the experimental groups (P<0.001), in which 3×60s and stepwise ethanol application groups showed the lowest Fad.No difference was found between these two groups (P>0.05).Conclusion When using AFM in air, ethanol-wet protocol with longer time can produce a less undulating and relatively smooth surface topography and decrease the Fad, whichindicates that the water saturated in dentin matrix was replaced more thoroughly by longer ethanol application time.This will benefit hydrophobicity of the dentin bonding interface.

Objective To explore the effect of entire process nursing intervention during nebulization treatment of acute wheezing episodes in school-age children.Methods One hundred and forty-one children with acute wheezing episodes were divided into the experimental group (75 patients) and the control group (66 patients) by whether willing to accept nursing intervention or not,respectively.Routine nursing such as cognition of wheezing knowledge and respiration instruction was given to both groups,while specialists accompanied the whole procedure of inhalation treatment and they gave nursing intervention such as respiration,saliva swallow,expiration through nose,grasp of inhalation tank and body position maintenance to the experimental group.The improvement of wheezing and subjective sense by the patients,transcutaneous oxygen saturation (SaO_2),and the compliance of patients were measured and evaluated.Results Improvement of wheezing and comfort feeling were found in 97.3% of the experimental group,while 80.3% of the control group.And SaO_2 value (higher than 95%) was 92.0% in the experimental group,75.8% in the control group.The compliance of the experimental group was also better than the control group.Conclusions Entire process nursing intervention during nebulization treatment can improve clinical effect and the compliance of wheezing children.

Objective To study the effects of Apelin on glucose toxicity and islet cells PDX-1 protein expression.Methods The islet β cell line NIT-1 cells were incubated in the medium containing different glucose concentrations(normal glucose concentration group 5.6 mmol/L,high glucose concentration group 16.7 mmol/L,extremely high glucose concentration group 33.3 mmol/L) and +/-Apelin-36 respectively for 3 d.Then the basic insulin secretion amount of islet cells and their secretion amount after glucose stimulation were detected.The intracellular insulin content and the PDX-1 protein and mRNA expression were detected.Results Compared with the normal glucose group,the basic insulin secretion,secretion after stimulation and intracellular insulin in the high glucose group and extremely high glucose group were significantly decreased and PDX-1 protein expression was declined(P＜ 0.05);compared with non-adding Apelin group,the basic insulin secretion,secretion after stimulation and intracellular insulin in the adding Apelin high glucose group and extremely high glucose group were significantly decreased and PDX-1 protein expression was decreased(P＜0.05);the insulin level in islet cells of 6 groups was positively correlated with PDX-1 protein expression and had no correlation with PDX-1 mRNA expression.Conclusion Apelin may participate in the glucose toxic effect by decreasing PDX-1 protein expression,causes the decrease of insulin secretion,thus plays a role in the pathogenesis of diabetes.

Objective:To explore the status of depression symptoms and related factors of depressive symptoms in middle-aged and elderly disabled people in China and provide references on the preventive cares of depression.Methods:Research data were obtained from the 2018 follow-up data of China Health and Retirement Longitudinal Study(CHARLS).Disabled people were selected as the research object. The scores of center for epidemiological studies depression scale(CES-D) were used to evaluate depressive symptoms. Fourteen variables derived from the 3 dimensions of demographic characteristics, health status, and health related behaviors were utilized in this study.SAS 9.4 were used for descriptive analysis, univariate analysis and Logistic regression analysis.Results:A total of 1 708 middle-aged and elderly disabled people were included, among whom 932(54.5%)were diagnosed with depressive symptoms, and the score of CES-D was (11.45±7.19).Self-rated poor health, self-rated poor memory, life dissatisfaction, physical pain were the risk factors of depressive symptoms ( OR=1.87, 4.22, 1.83, 5.30, 1.75). Male, educational level (middle-high school, high school or above), sleeping duration (6-9 h) were the protective factors of depressive symptoms( OR=0.74, 0.72, 0.10, 0.56). Conclusion:Middle-aged and elderly disabled people in China have a high detection rate of depressive symptoms. Female, lower education background, inadequate amount of sleep, self-rated unsatisfactory healthy, self-rated poor memory, dissatisfaction towards life and suffering from physical pain may be more likely to have depressive symptoms in middle-aged and elderly people with disabilities.

Objective To research the efficacy of using low dose dexmedetomidine in short time to prevent restless after laparoscopic surgery. Methods Forty patients ASA grade ⅠorII,age 20~70 yeas old,scheduled for selective laparo-scopic cholecystectomy or ectopic pregnancy or oophorocystectomy etc,operation time about 30min,were randomly as-signed to low groupsgroup D and N. Group DIntravenous dexmedetomidine(0.5~0.8)μg/(kg·h) when we inducing,for 10~15 min,no more than 50 μg; Group Nno dexmedetomidine. Observed extubation tiwe after surgery,riker sedation and restless score(SAS),restless incidence rate. Results There was no obvious difference in the time of extract the tra-cheal tube (P>0.05). The SAS in group D was significantly lower than group N (P<0.05),incidence of restlessness of group D was significantly lower than N. Conclusion Intravenous low dose dexmedetomidine while inducing for short time can effectively prevent restlessness after Laparoscopic Surgery.

Objective: To investigate the analgesic mechanism of Tuina (Chinese therapeutic massage) by observing the effect of the N-methyl-D-aspartate receptor subunit 2B (NR2B)/postsynaptic density-95 (PSD-95) pathway on the dendritic structure of spinal cord dorsal horn in rats with lumbar disc herniation. Methods: Fifty Sprague-Dawley rats were randomly divided into a blank group, a model group, a Tuina group, a blocker agent group, and a blocker agent + Tuina group. The sciatic nerve chronic constriction injury (CCI) model was prepared by the sciatic nerve ligation method. From the 4th day after modeling, rats in the Tuina group and the blocker agent + Tuina group were subject to daily Tuina intervention, and those in the blocker agent group and the blocker agent + Tuina group were daily intrathecally injected with NR2B blocker agent (MK-801). The spontaneous pain score was used to observe the pain behavior of all rats. The expression levels of NR2B and downstream PSD-95 were measured by immunohistochemistry, and the dendritic structure changes were observed by Golgi staining for rat spinal cord dorsal horn after 14 d of continuous intervention. Results: Compared with the blank group, the degree of rat spontaneous pain after CCI was elevated in both the model and the Tuina groups (P<0.01) and was reduced in the Tuina group after the Tuina intervention compared with the model group (P<0.05). Compared with the model group, the rat spontaneous pain level after blocking NR2B was reduced in both the blocker agent group and the blocker agent + Tuina group (P<0.05). The NR2B and PSD-95 protein levels were significantly higher in the model group compared with the blank group (P<0.01); the total number of dendritic branches was increased (P<0.01), and the total dendritic length became longer (P<0.01) in the spinal cord dorsal horn. The rat NR2B and PSD-95 protein levels were significantly decreased in the Tuina group compared with the model group (P<0.01); the total dendritic branch number was reduced (P<0.01) and the total length was shortened (P<0.01) in the spinal cord dorsal horn. After blocking NR2B, the expression levels of NR2B and downstream PSD-95 protein were significantly lower in both the blocker agent group and the blocker agent + Tuina group compared to the model group (P<0.01). The total branch number was significantly reduced (P<0.01), and the total length was significantly shortened (P<0.01) of the dendrites in the spinal cord dorsal horn. Conclusion: Tuina may exert an analgesic effect by remodeling the dendritic structure in the spinal cord dorsal horn in rats with lumbar disc herniation, and its mechanism may be related to the inhibition of NR2B/PSD-95 signaling pathway.

Objective To study the prevalence and related risk factors of type 2 diabetes with coronary heart disease(CHD) and cerebral infarction after long-term treatment.Methods Two hundred and eighty-five patients with type 2 diabetes who had a hospitalization interval for four to twelve years between the first and second hospital stays were included in group A.Among them,85 patients (about 4 to 7 years) with a hospitalization interval about 5 years (4 to 7 years) between the first and second hospital stays(group B).100 patients with a hospitalization interval about 10 years (8 to 12 years) between the first and second hospital stays(group C).Blood pressure,blood glucose,HbA1c,blood lipids,myocardial enzymology,electrocardiogram,coronary angiography,cranial CT or MRI were tecorded.The prevalence of CHD and cerebral infarction were compare,regression analysis was conducted between coronary heart disease,cerebral infarction and the risk factors.Results DBP,FBG,PBG2h,TC,LDL-C of the second hospitalization were significantly lower than those of the first hospitalization.The morbidity of CHD and cerebral infarction increased along with the extension of the course.The morbidity of cerebral infarction in CHD patients were significantly higher than those in non-CHD patients with the interval about 10 years.Logistic regression analysis proved that age was risk factor and HDL-C was protective factor of CHD,SBP,FBG were risk factors of cerebral infarction.Conclusion The morbidity of CHD and cerebral infarction increased along with the extension of the course and there were significantly relationship between CHD and cerebral infarction in T2DM patients after about 10 years treatment.

OBJECTIVETo evaluate the effect of pretreatment with ethanol on dentin to compensate premature volatilization of self-etch adhesive system.

METHODSThirty-two intact human molars were randomly divided into two groups using a table of random numbers (n = 16): A, an acetone-base adhesive (G-bond) and B, an ethanol-based adhesive (Clearfile S(3) bond). Then each group was randomly assigned into foursub groups (n = 4) : group 1, no premature volatilization; group 2, premature volatilization; group 3, premature volatilization + stepwise ethanol pretreatments; and group 4, premature volatilization + absolute ethanol treatment. After composite resin building, microtensile bond strengths (MTBS) of each subgroup were then tested. Fracture modes were classified by stereomicroscopy and representative interface was observed by field-emission scanning electron microscopy (FE-SEM).

RESULTSFor adhesive A, there was significant difference on MTBS among different subgroups (P < 0.05); the MTBS of group A2 [(26 ± 12) MPa] and A4 [(27 ± 7) MPa] was lower than that of group A1 [(41 ± 11) MPa] and A3 [(40 ± 11) MPa] (P < 0.05). No significant different was found between group A2 and A4 (P > 0.05); neither between group A1 and A3 (P > 0.05). For adhesive B, there was no difference on MTBS among different subgroups (P > 0.05).FE-SEM showed that the main fracture mode was located at the bottom of the hybrid layer for adhesive A groups, the collagen fibrils were capsulated by resin monomers more densely in group A1 and group A3 in comparison with other two subgroups.For adhesive B groups, the main failure modes were at the top of the hybrid layer.

CONCLUSIONSPremature volatilization can obviously decrease the bonding strength of acetone-base self-etch adhesives, but has no significant effect on ethanol-based self-etch adhesives. Dentin pretreatment with a series of increasing ethanol concentrations can effectively compensate the adverse effect of premature volatilization of acetone-base self-etch adhesives on bonding strength.

Adhesives ; Composite Resins ; Dental Bonding ; Dental Materials ; Dental Stress Analysis ; Dentin ; Dentin-Bonding Agents ; Ethanol ; chemistry ; Humans ; Methacrylates ; Microscopy, Electron, Scanning ; Molar ; Resin Cements ; Tensile Strength ; Volatilization

Degradation of composite resin during ageing always produces micro-cracks, the latter could gradually expand, leading to the fracture of tooth restoration. In order to extend the service life of composite resin by repairing cracks intelligently, self-healing microcapsule models have been introduced in resin-based dental materials. This paper will present the concept and classification of self-healing materials, and review the research progresses on self-healing dental resin.

As one of the rapid prototyping technology, three-dimensional (3D) printing is booming since its birth. 3D printing has already been applied in biomedical engineering, medical mold processing and many healthcare fields, but its application in dental education is still in the exploratory stage. Nowadays, educators are seeking to integrate 3D printing and dental education. On the basis of the advantages of 3D printing, the quality of dental education will be further improved and students′ enthusiasm for learning will be stimulated. This article will focus on elaborating the recent advances of 3D printing in dental education and exploring its direction in the field of teaching.