OBJECTIVETo evaluate the influence of eugenol-containing and resin-containing endodontic sealers on the bond strength of fiber posts using different strategies of root canal irrigation.

METHODSForty-eight mandibular premolars were endodontically treated. The specimens were randomly assigned into two groups according to different endodontic sealers. Group A used Endofil (eugenol-containing endodontic sealer), and group B used AH-plus (resin-containing endodontic sealer). After post space preparation, each group was randomly assigned into three subgroups according to the strategies of root canal irrigation (eight premolars in each subgroup). Group Al and B1: 0.9%NaCl irrigation; Group A2 and B2: 17% ethylene diamine tetraacetic acid (EDTA)+5.25%NaClO+0.9%NaCl irrigation; Group A3 and B3: ultrasonic agitation associated with 1 7%EDTA+5.25%NaClO+0.9%NaCl. One week after the cementation of fiber posts using RelyX™ Unicem, a push-out test was performed to measure the bond strength of the posts. The microstructure of the root canal surface was examined under scanning electron microscope (SEM).

RESULTSThe bond strengths of the six groups were as follows: Al (7.96±2.23) MPa, A2 (9.95±2.89) MPa, A3 (18.88±3.69) MPa, B1 (11.41±3.71) MPa, B2 (14.00±4.04) MPa, and B3 (19.14±3.27) MPa. Statistical analysis revealed a significant interaction between the different endodontic sealers and the strategies of root canal irrigation (P<0.05). Lower bond strength was found in group Al but not in group BI (P<0.05), and the same result was revealed when comparing group A2 and B2. No significant difference was observed between group A3 and B3 (P>0.05). SEM showed that the root canal in group A3 and B3 achieved the cleanest surface with nearly all dentine tubules opened.

CONCLUSIONThe eugenol-containing endodontic sealer can impair the bond strength of fiber posts compared with the resin-containing sealer when the root canal is irrigated by 0.9% NaCl or 17%EDTA+5.25%NaClO+0.9%NaC. No difference was observed between the two sealers when using 17%EDTA+5.25% NaCIO+0.9%NaCl combined with ultrasonic irrigation.

Bicuspid ; Cementation ; Dental Bonding ; Dental Pulp Cavity ; Dental Stress Analysis ; Dentin ; Humans ; Post and Core Technique ; Root Canal Filling Materials ; Root Canal Irrigants ; Root Canal Therapy

OBJECTIVETo evaluate the effect of different auxiliary resistance forms on the resistance and marginal fitness of complete crowns for short molar preparations.

METHODSA total of 70 Nissin resin teeth were prepared with 20° total occlusal convergence, 2.5 mm of occlusocervical height, and a shallow finish line on a milling machine. The milled preparations were then randomly assigned to 7 groups of 10. The first group was used as the control group. A total of 30 dies were modified by preparing interproximal grooves with angles of 0°, 6°, and 20° centered on the mesial and distal surfaces of the dies. The rest of the teeth were prepared with occlusal holes in the center of the occlusal surface milled with the same burs to form 0°, 6°, and 20° holes. Cobalt-chromium copings were fabricated for all specimens. The marginal gap of specific points on the axial surface was measured before and after cementation. The resistance of each specimen was evaluated by applying an external force at an angle of 45° to the long axis of the die by using a universal testing machine in a lingual to buccal direction. The maximum force applied before crown dislodgement was measured. Data were analyzed using the SAS 9.2 software.

RESULTSThe results showed that the 0° groove, 0° hole, and 6° hole were effective in improving the resistance of the complete crowns (P<0.05). The 0° groove, 6° groove, 0° hole, 6° hole, and 20° hole had significant difference with the control group in terms of marginal discrepancies (P<0.05).

CONCLUSIONAuxiliary resistance forms with less degree indicate greater resistance force but worse marginal fitness. In clinical practice, if the resistance of a preparation is enough, the auxiliary resistance forms should be avoided from being used.

Cementation ; Crowns ; Dental Prosthesis Design ; Dental Prosthesis Retention ; Humans ; Molar ; Tooth Crown

Objective To construct the prokaryotic expression vector bearing fusion gene NT4-ADNF-9 and lay foundation for further study on genetic therapy of neuraseusory deafness. Methods By means of asymmetrical prince/ template, double stranded eDNA of activity dependent neurotrophic factor-9 (ADNF-9) was obtained, which included restriction enzymes sites on the two extremities. ADNF-9 eDNA was ligated to the signal and leader peptides of nenrotrophin 4 (NT4), and the fusion gene was named NT4-ADNF-9. Then it was suheluned into prokaryotic expression vector pBV220, and called pBV220/ NT4-ADNF-9. Results Evidences of DNA sequence analysis and restrtction enzymes digestion showed that we recombined ADNF-9 eDNA to the 3'terminal of the signal and leader peptides of NT4, and the fusion gene was subcluned into pBV220 successfully. Bioactivity of the products was proved that it could support the cell survival and neurite growth in the primary cultures of dorsal root ganglia (DRG) of embryonic day-8 cbicken neurons as compared to the control. Conclusion Prokaryotic expression vector pBV220/NT4-ADNF-9 can be constructed successfully and the bioactivtty is satisfactory.

Objective To prepare a kind of new lipid perfluorooctylbromide(PFOB) nanoparticles and to explore its potential application as an ultrasound contrast agent. Methods Lipid PFOB nanoparticles were prepared by microfluidization techniques. The morphology and distribution were observed with optical microscope and transmission electron microscope. Particle size and electric potential were determined with Malvern laser light scattering analyzer. Twelve normal Wistar rats were performed directly contrast imaging after injection of PFOB nanoparticles via caudal vein. Vital signs of the rats were monitored during the whole study. And eehogenie intensity of the liver was dynamically quantified through DFY ultrasound quantified analysis system. The mechanism of enhancement was studied by the frozen sections of rat's liver and spleen. Results The nanoparticles size and distribution were highly uniformed. The grey scale ultrasound imaging of the rat's liver and spleen were enhanced by PFOB nanoparticles. Ten seconds after PFOB nanoparticles injected,enhancement of liver began, the peak time was approximately 3 - 4 min, the duration of contrast enhancement was nearly up to 1 h, The enhancement of spleen was more significant and the duration was much longer. No abnormal changes of the rat's vital signs appeared during the study. Frozen sections suggested that PFOB nanoparticles accumulated in the liver and spleen was the potential mechanism of enhancement. Conclusions This novel and safe lipid PFOB nanoparticles could make prolonged enhancement of rat's liver and spleen,which has a good potency for ultrasound application.

Balloon Occlusion ; Esophageal and Gastric Varices ; Humans ; Polyethylene Glycols ; Sclerotherapy

Superior mesenteric vein (SMV) thrombosis is a relatively rare disease. Most patients may be successfully treated with anti-coagulation alone. However, bowel stricture may develop due to intestinal ischemia which may require surgical treatment. This report describes a rare case of small bowel stricture occurring one month after successful treatment of SMV thrombosis. After segmental resection of strictured bowel, the patient's post-operative course was uneventful.

Objective:To review literature reports of varieties of ADRs induced by mebendazole to provide a sci- entific foundation for clinical revaluation of mebendazole.Method:The related literatures in the internal and external medi- cine medical database in 1994-2004 were explored,and then both analysis and statistics were conducted with the methods of epidemiolngy and literature analysis.Result:ADRs induced by mebendazole could be involved in multiple organs.Most victims were children and the elderly.Their latent periods were determined by the types of ADRs,which had a variety of forms.Conclusion:Mebendazole was potentially unsafe.So we should strengthen our rational drug use and post-marketing revaluation of safety.

Objective:To investigate the short-term effect of thoracoscopic and laparoscopic surgery in the treatment of esophageal cancer and its impact on stress response and inflammatory response.Methods:The clinical data of 124 patients with esophageal cancer admitted to Huai′an Cancer Hospital from March 2018 to March 2020 were analyzed. The patients in observation group (62 cases) were treated with thoracoscopic esophagectomy and the patients in control group (62 cases) were treated with traditional open esophagectomy. The changes of perioperative indexes, postoperative complications, stress response, inflammatory response indexes before and 3 d after operation, and pulmonary function before and 1 month after operation were compared between the two groups.Results:The intraoperative blood loss in the observation group was less than that in the control group: (189.52 ± 37.28) ml vs. (258.94 ± 32.14) ml; the operation time in the observation group was longer than that in the control group: (271.92 ± 25.43) min vs. (231.09 ± 23.16) min, and the differences were statistically significant ( t = 11.105, 9.347, P<0.05). But there was no significant difference in the total number of lymph node dissection between the two groups ( t = 1.295, P>0.05). The postoperative complications in the observation group was less than that in the control group: 9.68%(6/62) vs. 24.19%(15/62), χ2 = 4.644, P<0.05. The serum levels of cortisol and norepinephrine at 3 d after operation in the observation group were lower than those in the control group: (145.32 ± 12.39) μg/L vs. (197.56 ± 18.78) μg/L, (84.54 ± 5.98) μg/L vs. (98.93 ± 7.26) μg/L, and the differences were statistically significant ( t = 18.283, 12.047, P<0.05). The serum levels of interleukin 6, C-reactive protein and tumor necrosis factoralpha at 3 d after operation in the observation group were lower than those in the control group: (101.31 ± 6.56) μg/L vs. (149.09 ± 12.31) μg/L, (18.94 ± 4.53) mg/L vs. (29.95 ± 4.16) mg/L, (84.52 ± 5.89) ng/L vs. (109.32 ± 8.64) ng/L, and the differences were statistically significant ( t = 26.972, 14.096, 18.675, P<0.05). The levels of the first second forced expiratory volume (FEV 1) as a percentage of the estimated value and the ratio of FEV 1 and forced vital capacity at 1 month after operation in the observation group were higher than those in the control group: (8.79 ± 4.50)% vs. (72.16 ± 3.64)%, (67.84 ± 3.24)% vs. (60.39 ± 4.15)%, and the differences were statistically significant ( t = 9.020, 11.142, P<0.05). Conclusions:The short-term effect of thoracoscopic and laparoscopic surgery in the treatment of esophageal cancer is obvious, and the stress response, inflammatory response and lung function are less affected.

Objective To investigate the diagnostic values of serum free fatty acids (FFA) and urine podocalyxin (PCX) in the patients with type 2 diabetic nephropathy(DN).Methods A total of 120 patients with type 2 diabetes mellitus (DM) were enrolled,and they were divided into three groups,normal albumin group(NA),microalbuminuria group(MA) and heavy albuminuria group(HA),based on the urinary albumin-creatinine ratio(UACR).In addition,40 healthy persons participated in medical examination were selected as the control group.Serum FFA levels were detected by a biochemical analyzer and urine PCX levels by ELISA.The correlation between them was analyzed by Pearson correlation,and their diagnostic values in type 2 DN were evaluated by the receiver operating characteristic curve (ROC).Results Serum FFA levels in the NA,MA,HA and control groups were (0.61 ± 0.14),(0.81 ± 0.13),(0.95 ± 0.18) and (0.49 ± 0.11) mmol/L,respectively,and urine PCX levels were (1.86 ± 0.45),(4.47 ± 1.48),(6.72 ± 1.40)and(1.38 ±0.24) ng/mL,respectively.The levels of serum FFA and urine PCX in type 2 DM patients were significantly higher than those in the control group(P ＜ 0.05),and increased with the progression of type 2 DM.Pearson correlation analysis showed that serum FFA levels were positively correlated with urine PCX levels(r =0.73,P ＜ 0.05).The sensitivity of serum FFA,urine PCX and combined detection in the diagnosis of type 2 DN were 74.1％,80.6％ and 89.5％,respectively,and the latter significantly higher than the former two (P ＜ 0.05).Conclusion Serum FFA and urine PCX levels increase significantly in diabetic patients with renal injury,and both of them have important clinical values in the diagnosis of type 2 DN.

Resident doctors participating in clinical teaching is a disputable topic.We analyze the current situation and difficulties in clinical teaching and propose the concept of RATS(residents as teachers) program in china aiming to strengthen the training of clinical teaching skills in residents and improving culture quality of resident doctors.And we also suggest the establishment of "clinical teaching data warehouses for resident doctors"to keep pace with requirements of our resident training program in new times.