Objective To explore the influence of different lengths and contents of glass-fiber post on the fracture resistance of teeth, and to investigate the optimal length and content of glass-fiber post used for restorative treatment. Meth-ods Forty-two intact single canal mandibular premolars were collected from orthodontic patients and were divided into three experimental groups (A, B and C). All the teeth were endodontically treated after cut off the crowns from the 2 mm above cemento-enamel junction. The post lengths were10 mm in A group, 8 mm in B group, and 6 mm in C group.There were two subgroups for each experimental group (A1, A2, B1, B2, C1, C2 ), 7 teeth for each subgroup.The 42%glass fiber post was used in A1, B1 and C1 groups. The 75%glass fiber post was used in A2, B2 and C2 groups. All of groups were restored with resin cores and metal crowns. The fracture resistance was measured with universal testing machine and recorded the root frac-ture pressure data and the mode of all the teeth. Results The fracture resistance was significantly higher in group A than that of group B and group C (P<0.05), and the fracture resistance was significantly higher in group B than that of group C (P<0.05). The fracture resistance was significantly higher for 75%glass fiber post than that of 42%glass fiber post (P<0.05). Conclusion Within a certain range, the longer the length of glass fiber post, the greater the tooth fracture resistance. The fracture resistance of fiber content is better for 75%glass fiber post than that of 42%glass fiber post.

Objective To evaluate the clinical effects and clinical classification of occlusal rehabilitation in elderly patients with abnormal occlusion, and to discuss the diagnosis principles and the practical techniques of the dental prosthesis for occlusal rehabilitation. Methods Forty two elderly patients with abnormal occlusion were treated with occlusal rehabilitation with fixed dentures, fixed-removable dentures and removable partial dentures. Eight patients among them simultaneously had temporomandibular joint(TMJ) disorder. After the clinical procedures including examination, diagnosis, prosthesis design, manufacture, application of occlusal rehabilitation and post-treatment evaluation, the using condition of dentures, patients' satisfaction ratings, TMJ functions and abutment teeth healthy status were examined before and after treatment. Results All the patients were satisfied with their dentures' general functions 1 year after treatment. Compared with the removable partial dentures, the other two types of prosthesis showed better clinical outcomes (χ2=4.15,P<0.05) and compacts on phonation of the dentures (χ2=4.71,P<0.05). In the 8 patients with TMJ disorder, 7 cases were cured completely. The treatment effects of TMJ pain (χ2=0.031, P<0.05)and TMJ click (χ2=0.038, P<0.05)had statistical differences. 30 teeth of the 203 abutment teeth (14.8%) had the problems of periodontal diseases and secondary caries and the incidences of these problems were higher in using removable partial dentures treatment than in the other two methods. Conclusions After the systematic diagnosis and the prosthesis design procedures of occlusal rehabilitation, it is important to choose a proper prostheses for the elderly patients according to their physical and psychological features, which may give the patients satisfactory results.

Objective To evaluate the curative effect of LASIK for correcting compound myopic astigmatism.Methods One hundred and sixteen eyes in 68 patients with compound myopic astigmatism had been corrected with LASIK.All patients were followed up for more than 12 months.Meanwhile,all eyes were divided into two groups according to the preoperative astigmatism:group I (-2.25～ -3.00D),group Ⅱ (-3.2.5～ -6.00D).Results In group I :the average refractive cylinder was (- 2.51±0.68) D preoperafion, and had the average of (- 0.51±0.25) D residual astegmatism postoperation.In group Ⅱ :the average refractive cylinder was (- 3.85±0.46) D preoperation, and had the average of (- 0.52±0.22)D residual astigmatism postoperation.There was no statistical difference in astigmatism between the two groups after 12 months.In group Ⅰ and Ⅱ the visual acuity after operation was better than the corrected visual acuity before operation.Conclusion For compound myopic astigmatism LASIK was safe and effective.

Objective To investigate the influence of perioperative continuing aspirin therapy on tooth extraction surgery in elderly patients with coronary heart disease.Methods A total of 926 patients with coronary heart disease who required tooth extraction were enrolled in this study.Among them,241 patients discontinued aspirin therapy before tooth extraction,685 patients continued aspirin therapy before tooth extraction.The entering rate of operation was evaluated.100 patients continuing aspirin and 100 patients discontinuing aspirin were randomly selected.Systemic pressure,diastolic pressure and heart rate before and after tooth extraction were detected.100 matched healthy elderly patients were selected as normal control group.Multivariate logistic regression analysis was used to estimate the risk for tooth extraction.Results The entering rate of operation was 67.9％ (131 cases) in 193 patients with angina pectoris discontinuing aspirin therapy and 82.1 ％ (312 cases) in 380 patients with angina pectoris continuing aspirin therapy (x2 =14.77,P＜0.01).The entering rate of operation was 41.7％ (20 cases) in 48 patients undergoing coronary revascularization and discontinuing aspirin therapy,and 80.7％ (312 cases) in 305 patients undergoing coronary revascularization and continuing aspirin therapy (x2=33.95,P＜0.01).The changes in systolic blood pressure before versus after dental extraction had a significant difference between the discontinuing aspirin group and control group [(15.9±5.5) mmHg vs.(12.2±4.7)mmHg,P＜0.05,1 mmHg=0.133 kPa],while had no significant difference between the continuing aspirin group and control group [(13.6±4.5) mmHg vs.(12.2±4.7) mmHg,P＞0.05].There were no significant differences in changes in diastolic blood pressure and heart rate in the intraoperative period between the patients and controls (P＞0.05).The bleeding rate in patients continuing aspirin therapy was not significantly different as compared with control group (P＞ 0.05).Multivariate logistic regression analysis revealed that perioperative discontinuing aspirin therapy remained the second significant risk factor for tooth extraction.Conclusions Preoperative administration of aspirin should be continued in dental extraction surgery in elderly patients with coronary heart disease.

Objective To analyze the clinical effects aftet one year of LASIK for myopia. Methods According to the preoperative diopters of the myopia, the patients were divided into three groups, group Ⅰ: 57 eyes( < - 6.00D), group Ⅱ: 109 eyes( - 6.25～ - 10.00D) ,group Ⅲ :31 eyes( > - 10.25D～ - 15.00D). The patients were followed up 1 year. Re- sults In groups,the percentage of the uncorrected visual acuity equal or more than 1.0 was 94.3%,80.3%,42.0% re- spectivdy. The percentage of there sidual refractive error within ±0.50D was 99.3% ,85.7% ,59.7%. The spherical e- quivalent was stable in 3 months after LASIK. The complications are few. Conclusion LASIK is a safe,effective and good predictable method for treatment of myopia.

Objective:To explore the changes of cerebral blood flow (CBF) perfusion caused by N 2O (laughing gas) abuse. Methods:From December 2017 to October 2018, the CBF perfusion images of 24 patients with laughing gas abuse (9 males, 15 females; age: 18-32(24.0±8.9) years) from China-Japan Friendship Hospital were analyzed retrospectively. The region uptake statistics of different brain regions of interest (ROI) (basal ganglia, central region, cerebellum, cingulate gyrus, frontal lobe, medial temporal lobe, occipital lobe, parietal lobe, temporal lobe) between patients with laughing gas abuse and normal people of the same age group from background software database were calculated automatically. Statistic>1.68 indicated the increase of local CBF perfusion, while statistic < -1.68 indicated the decrease of local CBF perfusion. The correlation between the statistics of bilateral brain regions and the correlation between statistical values and clinical indicators were analyzed by Pearson and Spearman correlation analyses.Results:The correlation of the statistics between bilateral regions of each brain area was significant( r values: 0.503-0.892, all P<0.05). The decreased CBF proportions of frontal and temporal lobes were 62.5%(15/24) and 70.8%(17/24), respectively. The highest proportion of increased CBF was cingulate gyrus (33.3%, 8/24). There were significant correlations between frontal lobe, central brain area and duration of laughing gas abuse ( rs values: 0.375, 0.305, both P<0.05). Conclusion:CBF perfusion imaging is helpful for understanding the changes of CBF in patients with laughing gas abuse.

Objective To observe the clinical efficacy ofTiaozhong YifeiPrescription combined with Western therapy for treatment of cough variant asthma (CVA) remission. Methods Totally 90 patients with CVA remission were randomly divided into TCM group, Western therapy group and TCM and Western therapy group, 30 cases in each group. TCM group was givenTiaozhong YifeiPrescription, 1 dose per day, morning and evening; Western therapy group was given salmeterol xinafoate and fluticasone propionate powder for inhalation, each 1 suction, 2 times a day, inhalation; a mixture ofTiaozhong YifeiPrescription and xinafoate and fluticasone propionate powder for inhalation was given to TCM and Western therapy group, the same as above, continuous treatment for 12 weeks. TCM syndrome score, EOS, IgE, pulmonary function and safety index were observed in the three groups before and after treatment. The recurrence rate and the number of colds after three-month treatment were observed.Results TCM syndrome scores in the three groups decreased after treatment (P<0.05). There was statistical significance between TCM group and TCM and Western therapy group after treatment (P<0.05). The total effective rate of TCM group was 96.67% (29/30), 100.00% (30/30) of Western therapy group, 76.67% (23/30) of TCM and Western therapy group, with statistical significance (P<0.05). After three-month treatment, 1, 0 and 11 cases relapsed in TCM group, TCM and Western therapy group and Western therapy group, respectively, with statistical significance (P<0.001). Compared with the Western therapy group, the number of colds in the TCM group and TCM and Western therapy group significantly decreased (P<0.05). Compared with before treatment, IgE decreased significantly (P<0.05). There was no significant difference in EOS among the three groups before and after treatment (P>0.05). After treatment, the maximum expiratory flow in TCM and Western therapy groupwas higher than that before treatment and lower than that in the Western therapy group (P<0.01), and the other lung function indexes were not statistically significant (P>0.05). 1 mild adverse reaction was found in the TCM and Western therapy, and no obvious adverse reactions were found in other groups (P<0.05).ConclusionTiaozhong Yifei Prescription has good clinical efficacy for CVA.

Objective: To investigate the value of pulmonary ventilation/perfusion (V/Q) SPECT imaging in fibrosing mediastinitis (FM). Methods: From January 2015 to July 2018, 14 FM patients (6 males, 8 females, average age 74 years) who underwent V/Q SPECT imaging in China-Japan Friendship Hospital were retrospectively studied. The data of V/Q SPECT imaging were analyzed and the defect extent was classified as mild (<20%), moderate (20%-50%) and severe (>50%) according to the percentage of pulmonary perfusion and ventilation defect in total lung volume (%). χ² test was used to analyze the incidence rates of the impaired blood perfusion of each lung lobe. Results: According to the results of Q SPECT imaging, all 14 patients had impaired blood perfusion in the superior lobe of left lung, and the number of patients with/without impaired blood perfusion in the inferior lobe of left lung, superior lobe of right lung, middle lobe of right lung, inferior lobe of right lung were 11/3, 14/0, 13/1, 12/2, respectively. The incidence rates of impaired blood perfusion in different lobes were not significantly different (χ²=6.198, P=0.185). The range of lung perfusion defect was mild in 1, moderate in 7 and severe in 6 patients. The incidence rates of impaired blood ventilation in different lobes were not significantly different (χ²=1.587, P=0.811). The range of lung ventilation defeat was mild in 11, moderate in 2 and severe in 1 patients. The defect extent of lung segments and subsegments in Q SPECT imaging and V SPECT imaging were 119 and 41, respectively (χ²=28.42, P<0.05). There was more defect in Q SPECT imaging, but both methods showed segmental or subsegmental distribution. Conclusions The defect of V/Q SPECT imaging in FM patients is segmental in distribution, and more is observed in Q SPECT imaging. Pulmonary V/Q SPECT imaging can evaluate the defect range and extent of pulmonary perfusion and ventilation in FM patients.

Objective:To analyze the clinical manifestations and duration of feeding intolerance (FI) in very low birth weight infants (VLBWI), explore the influencing factors of FI, so as to provide scientific basis for shortening the FI duration of VLBWI.Methods:From January 2018 to December 2020, 441 VLBWIs admitted to the Neonatal Intensive Care Unit of the Shandong Provincial Hospital Affiliated to Shandong First Medical University were selected as the research object by the convenient samplingto describe the clinical characteristics and duration of FI in children. Multivariate Logistic regression was used to analyze the influencing factors of FI duration of VLBWI. Totally 354 VLBWIs were included, excluding 41 children transferred from other hospitals 24 hours after birth, 10 children died before full gastrointestinal feeding, 4 children with stageⅡ or above neonatal necrotizing enterocolitis, 1 child with congenital gastrointestinal malformation, and 31 cases with incomplete data.Results:The incidence of FI in 354 VLBWI was 71.5% (253/354), and the average duration was 9 days. Multivariate Logistic regression analysis showed that the long time of invasive positive pressure ventilation [ OR=1.081, 95% CI (1.034, 1.130) ], formula feeding [ OR=1.751, 95% CI (1.009, 3.040) ] and hypertension during pregnancy [ OR=1.876, 95% CI (1.073, 3.279) ] were the risk factors for FI duration ( P<0.05), andbirth weight [ OR=0.355, 95% CI (0.185, 0.683) ]was the influencing factor of FI duration ( P=0.002) . Conclusions:The incidence of FI in VLBWI is high and the duration is long. Small gestational age and low weight premature infants are the high-risk groups of FI. In order to shorten the FI duration of VLBWI, medical and nursing staff should manage the blood pressure of pregnant women during pregnancy, strengthen the nursing of children during mechanical ventilation, withdraw the machine as soon as possible, and promote breastfeeding.

OBJECTIVE: To determine the carrier rate of deafness-related genetic variants among 53 873 newborns from Zhengzhou. METHODS: Heel blood samples of the newborns were collected with informed consent from the parents, and 15 loci of 4 genes related to congenital deafness were detected by microarray. RESULTS: In total 2770 newborns were found to carry deafness-related variants, with a carrier rate of 5.142%. 1325 newborns (2.459%) were found to carry heterozygous variants of the GJB2 gene, 1071 (1.988%) were found with SLC26A4 gene variants, 205 were found with GJB3 gene variants (0.381%), and 120 were found with 12S rRNA variants (0.223%). Five newborns have carried homozygous GJB2 variants, two have carried homozygous SLC26A4 variants, five have carried compound heterozygous GJB2 variants, and four have carried compound heterozygous SLC26A4 variants. 33 neonates have carried heterozygous variants of two genes at the same time. CONCLUSION The carrier rate of deafness-related variants in Zhengzhou, in a declining order, is for GJB2, SLC26A4, GJB3 and 12S rRNA. The common variants included GJB2 235delC and SLC26A4 IVS7-2A>G, which are similar to other regions in China. To carry out genetic screening of neonatal deafness can help to identify congenital, delayed and drug-induced deafness, and initiate treatment and follow-up as early as possible.