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Objective:To examine the effects of different endodontic irrigation methods on root canal morphology.Methods:We collected 20 extracted single-root premolars from elderly patients(≥60 years)with periodontitis and randomly divided them into 5 groups.Group A: syringe irrigation; Group B: P5 ultrasonic irrigation, Group C: 0.20 W Er: yttrium aluminum garnet(YAG)laser irrigation; Group D: 0.30 W Er: YAG laser irrigation; and Group E; 0.35 W Er: YAG laser irrigation.Changes in the smear layer in the root canal and the hardness of the root canal were assessed.Results:After treatment with different root canal cleaning methods, the scores of smear layer removal for Groups A, B, C, D and E were(4.67±0.27), (3.08±0.57), (2.83±0.43), (1.17±0.19)and(2.87±0.50), respectively.There were statistically significant differences between them( F=35.946, P<0.01). Among them, Group B, C, D and E had better smear layer removal than Group A, and the differences were statistically significant(all P<0.01). Group D had better removal of the smear layer than Groups B, C and E, and the differences were statistically significant( P<0.01); Values for dentin microhardness of Groups A, B, C, D and E were(58.98±5.54), (55.19±5.71), (56.04±3.96), (66.65±3.23)and(45.68±7.58), respectively, with statistically significant differences( F=5.83, P<0.05), and for laser-based irrigation, the value for dentin microhardness of Group D was higher than those of groups C and B(all P<0.05). Conclusions:Laser-based root canal irrigation is better than traditional irrigation methods, with 0.30 W Er: YAG laser achieving maximal removal of the smear layer and at the same time having the least impact on root canal hardness.
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Objective:To investigate the effect of radioactive 125I seed on angiogenesis of subcutaneously transplanted hepatocellular carcinoma in nude mice and underlying mechanism. Methods:The subcutaneous transplanted tumor model of human hepatocellular carcinoma Huh7 cells was established in nude mice. Twelve nude mice were randomly divided into observation group and control group with 6 mice in each group. The 125I seed with activity of 2.96×10 7Bq was implanted into the transplanted tumor of observation group and another with 0 Bq as control group, respectively. The volume of the transplanted tumor was measured every 4 d and the growth curve of the tumor was recorded. The microvessel density (MVD) of the transplanted tumor was evaluated by immunohistochemical detection of CD31. VEGF-A and HIF-1α protein and mRNA were detected by immunohistochemistry and RT-PCR, respectively. Results:The growth rate of tumor in the observation group was slower than that in the control group, and the difference of tumor volume between two groups at 12 d after 125I seed implantation was significantly different( t=3.167, P<0.05). At 28 d after transplantation, the tumor volumes of control and observation group approached to (963.61 ± 89.56) mm 3and (602.10±75.98) mm 3, respectively. The MVD of the observation group was significantly lower than that of the control group ( t=6.361, P<0.05). The relative expression of VEGF-A and HIF-1α mRNA in the observation group was significantly lower than that in the control group ( t=10.480, 6.414, P<0.05). Protein expression levels of VEGF-A and HIF-1α in the observation group were lower than those in the control group ( t=10.890, 12.250, P<0.05). Conclusions:Radioactive 125I seed can inhibit the growth of HCC xenografts by reducing tumor microvessels, which may be related to the decrease of VEGF-A and HIF-1α expression.
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Epigenetic mechanisms influence gene expression and function without modification of the base sequence of DNA and may generate a genetic phenotype.Epigenetic modifications include DNA methylation,histone modifications,and deployment of noncoding RNA.There is growing evidence that epigenetic mechanisms could play a crucial role in the development of diabetic retinopathy (DR).Molecular biological methods which could maintain mitochondrial homeostasis through the regulation of epigenetic mechanisms may prevent the development of DR.Epigenetic-related treatment modalities will become the new direction of targeted therapy for DR.
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As the new health care reform have been gradually deepened, hospital internal audit staffs should change ideas, change work strategies and methods, expand the area of audit business. Combining the working practices and experiences of the internal auditing, discuss the area of hospital internal auditing business under the new situation, then put forward suggestions for the internal audit function.
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Objective To determine the relationship between serum vitamin B_(12)(VB_(12))level and multiple sclerosis(MS).Methods The pertinent articles of the VB12 and the case control studies of MS were retrieved comprehensively by manual retrieval and computer retrieval.The methodology quality of the retrieved artilces were evaluated,and the arcb'cles were screened.Heterogeneity test was performed.The valid data was extracted and analyzed by Stata 10.1.Results In this study,9 studies were included.A total of 807 subjects were enrolled,including 414 patients and 393 controls.The Meta-analysis showed that the serum level of VB_(12) in patients with MS was lower than that in controls(standardized mean difference-0.24,95% CI-0.39 to-0.10).The sensitivity analysis indicated that the result of meta-analysis was reliable.Conclusion The serum level of VB_(12) might be associated with MS,and the deficiency of VB_(12) may contribute to the development of MS.