OBJECTIVEThis study aims to evaluate the shaping capability of Reciproc, WaveOne, Mtwo, and ProTaper instruments in simulated root canals.

METHODSA total of 40 simulated resin blocks were divided randomly into four groups. Each group was prepared with Reciproc (Group 1), WaveOne (Group 2), Mtwo (Group 3), and ProTaper (Group 4). The preparation time and reduction in working length after preparation were measured. Pre- and post-operative images were obtained with a scanner and superimposed through Photoshop. The changes in canal curvature and material removal from the inner and outer canal walls at 10 points beginning at 1 mm from the end point of the canal were measured with Image J. Centering capability was determined accordingly. Data were analyzed through one-way ANOVA, SNK, and Kruskal-Wallis at a significance level of P < 0.05.

RESULTSThe preparation time of Group 2 was (53.7 ± 6.7) s, whereas those of Groups 1, 3, and 4 were (86.9 ± 8.1) s, (112.2 ± 8.2) s, and (177.9 ± 11.2) s, respectively; the difference was found to be significant (P < 0.05). The reductions in working length among the four groups after preparation were not significantly different (P > 0.05). The canal curvature for Groups 1 to 4 were 2.671° ± 0.637°, 2.667° ± 0.450°, 3.664° ± 0.870°, and 3.797° ± 0.601°, respectively. The changes for Groups 1 and 2 were significantly smaller than those for Groups 3 and 4. At the 3 mm point, the transportation of Group 1 was (-0.016 ± 0.094) mm, which was significantly less than that of the other instruments (P<0.05). At the 4 mm and 5 mm points, the trans- portation values of Group 2 were (-0.080 ± 0.104) mm and (-0.312 ± 0.088) mm, which were significantly less than that of Group 1 [(-0.243 ± 0.099) mm, (-0.404 ± 0.064) mm, P < 0.05].

CONCLUSIONReciproc and WaveOne can complete preparation faster and can maintain the original canal curvature better than Mtwo and ProTaper. Reciproc exhibits superior centering capability in the apical part of the canal, whereas WaveOne exhibits superior centering capability in the middle part of the canal.

Objective To assess the prevalence of the A to G mutation at position 3243 of the mitochondrial tRNALeu(UUR) gene in type 2 diabetes in a Chinese population. Methods We screened 716 randomly selected, unrelated patients with type 2 diabetes for the mutation with a PCR-RFLP technique. Results Three individuals with this mutation were identified, representing approximately 0. 4％ of the type 2 patients screened. Further screening of first degree relatives of these 3 patients identified another 4 affected carriers. In comparison with type 2 diabetic patients without the mutation, these 7 carriers of the mt3243 mutation had:①an earlier onset of diabetes (38. 0±10.1 yr vs 53. 4±10.0 yr, P ＜0. 001) ;②lower BMI (19.5±2.0 vs 24. 9±10. 9, P ＜0. 0001) ;and ③ lower post-challenge insulin levels (Area under the curve of insulin levels during the OGTT, 2946± 1647.2 vs 7469±6647.7, P ＜ 0. 01). In addition, we screened the same 716 patients with type 2 diabetes, as well as 181 controls with normal glucose tolerance,for a newly described mt 3316 G→A mutation. This mutation was found in 16 patients with type 2 diabetes (2.20％) and 5 controls (2.7％). Therefore, the frequency of the mutation was not different between patients and controls.Moreover, clinical characteristics such as age of onset of diabetes, BMI, and insulin levels were not different between diabetic patients with the mt3316 mutation and those without it. Concision The mt3316 G→ A mutation is a polymorphism unrelated to diabetes.

Objective:To compare the effect of four different techniques on removal of vapor lock in the apical region of curved root canals.Methods:Forty simulated resin root canals with 45° curvature were prepared using WaveOne Primary,then the apical foramen were sealed with soft wax.The teeth were divided randomly into 4 groups thereafter (n =10).Contract solution was injected into the canals using a 30 G side-vented needle and scanned with cone-beam CT (CBCT) to identify the volume of the vapor lock.Four different techniques including photon-induced photoacoustic streaming (PIPS) laser-activated irrigation,gutta-percha cone technique,ultrasonic irrigation,and sonic irrigation were used to remove the vapor locks in the root canals.The residual volume of the vapor lock was identified again using CBCT scanning data.Accordingly,the reduction rates of the vapor lock were calculated.Furthermore,the initial and residual vapor lock length was calculated.The data were analyzed by using the One-Way ANOVA analysis and Kruskal-Wallis H test at a significance level of P ＜ 0.05.Results:There was no significant difference in the initial vapor lock volume (P ＞ 0.05).Residual volume of the vapor lock for PIPS laser-activated irrigation was 0 mm3,and that for gutta-percha cone technique was (0.02 ± 0.07) mm3,significantly lower than those of ultrasonic and sonic irrigation,the values being (0.20 ± 0.09)mm3 and (0.23 ±0.06) mm3 (P ＜0.001),respectively.The reduction rates of the vapor lock of PIPS laser-activated irrigation and gutta-percha cone technique were 100.00％ (100.00％,100.00％) and 100.00％ (77.66％,100.00％),respectively,significantly higher than those of ultrasonic irrigation [70.37％ (56.41％,91.43％)] and sonic irrigation [63.54％ (51.47％,74.00％),P ＜0.001].The length of the residual vapor lock for PIPS laser-activated irrigation was 0 mm,and that for gutta-percha cone technique was (0.15 ±0.47) mm,significantly lower than those of ultrasonic and sonic irrigation,values being (2.21 ±0.09) mm and (2.34 ±0.08) mm (P ＜0.001),respectively.The length of the residual vapor locks in the ultrasonic and sonic group remained approximately the same as the distance between the working tip and the apical foramen.Conclusion:PIPS laser activated irrigation and gutta-percha cone technique could remove the vapor lock from the apical region of curved canals effectivelv.

Objective: To evaluate effect of the morphology of simulated S-shaped root canals with Reciproc or Mtwo instruments on root canal irrigation. Methods: A total of 40 simulated S-shaped resin blocks were randomly divided into 2 groups (n=20), which was prepared by Reciproc or Mtwo. Blue ink was injected with constant speed and volume into the canals using 30G lateral opening syringe. hTe distance from needle tip to apex and vapor lock length were measured. A type of 25# 0.04 gutta-percha point was used to stir and remove the vapor lock. hTe time for removal of the vapor lock was recorded. Another syringe was used to inject saline into the canals and to measure the length of stagnant water. Results: hTe distance from needle tip to apex in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.276 ± 0.221) mm vs (3.459 ± 0.205) mm,P<0.05]. The vapor lock length in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.472 ± 0.230) mm vs (3.668±0.217) mm,P<0.05]. hTe time to remove vapor lock was signiifcantly shorter in the Reciproc group than that in the Mtwo group [(10.13 ± 1.79) s vs (15.29 ± 2.15) s,P<0.05]. The length of stagnant water was also shorter in the Reciproc group than that in the Mtwo group[(1.351 ± 0.142) mm vs (2.245 ± 0.206) mm,P<0.05]. Conclusion: hTe morphology of S-shaped root canal affects the root canal irrigation. hTe effect of root canal irrigated by Reciproc is better than that by Mtwo.

With the increasing international exchange of medical education , frequent exchanges increasingly of medical personnel through the cross-border and trans-regional .It caused widespread concern about the quality of medical education in different countries .This review focus on quality performance on the certification requirements of the standard of medical education .We take it as an opportunity to assess international medical education accredi-tation, and promote the reformation of teaching and examination .We tried to explore and establish the full quality assessment system for biochemistry .

Objective To explore the effect of nurse-in-charge-led ward rounds on the multi-level training of nurses. Methods The traditional nursing ward round was adopted from Juanuary to December 2013 and the nurse-in-charge-led ward round was adapted from January to December 2014. The nurse-in-charge-led round mode and flowchart was developed by designating one nurse-in-charge to carry out the process of nursing round and other nurses in the group to carry out nursing interrogation, check-up, physical examination, nursing diagnosis, making nursing strategy and conclusion. Additionally, the two links of nurse-in-charge-led seminar and nursing feedback were added in the nursing round. The effect of nursing ward round and the results of nursing examination were compared between before and after the improvement. Results A year after implementing new nursing round mode, the effect of nursing round was significantly better than that before the implementation of new mode and the nursing examination score was significantly higher than that before its implementation (all P < 0.05). Conclusion The nurse-in-charge-led round mode can improve the effect of nursing round, improve clinical and professional ability to discover, analyze and solve problems.

asic life care should be carried out immediately.

Background Sphingosine-l-phospate (S1P) is a bioactive lipid and important messenger molecule in cells.It participates in the regulation of many biological processes,such as cell proliferation,migration,survival,differentiation,apoptosis,etc.Hypoxia is a trigger factor of choriod neovascularization (CNV) and pathological basis of many diseases,and retinal pigment epithelial (RPE) cells are involved in formation of CNV.However,the effects of S1P on proliferation and apoptosis of RPE cells are below understood.Objective This study was to investigate the influence of S1P on proliferation and apoptosis of human RPE cells under hypoxic conditions.Methods Human RPE cells line-D407 cells were cultured and passaged and generation 3-5 cells were used and divided into 6 groups.The cells were regularly cultured in the blank control group using DMEM containing 10％ fetal bovine serum.CoCl2(200.00 μmol/L) was added into the colture medium for 2 hours in the hypooxic group.S1P of different concentrations (0.01,0.10,1.00,10.00 μmol/L) were added in culture medium 2 hours after the affection of 200.00 μmol/L CoCl2.The proliferative values of the cells were detected using WST-1 method as the absorbance (A value) and the proliferative rate of different groups were calculated.The apoptosis of the cells was assayed by Hoechst staining.The results were compared among different groups.Results Cultured cells showed the round-like in shape with clear nuclei and pigment.The proliferative values (A value) was 0.91 ±0.08,0.37±0.09,0.46±0.08,0.52±0.09,0.61 ±0.06,0.70±0.10 in the blank control group,hypoxic group and 0.01,0.10,1.00,10.00 μmol/L S1P groups,respectively,with a significant difference among the groups (F=21.104,P=0.000),and A values in various S1P groups were higher than those in the hypoxiac group (all at P＜0.05).The proliferative rate was gradually raised with the increase of dose of S1P.Hoechst staining exhibited a few apoptosis cells in the blank control group,but in the hypoxic group,a lots of apoptosis cells were seen with the light-blue nuclei and condensable chromatin.However,the number of apoptosis cells was significantly decreased in various concentrations of S 1 P groups.The apoptosis rates were (1.21 ±0.08) ％,(8.99 ±0.09) ％,(6.60 ±0.08) ％,(5.95 ±0.09) ％,(4.81 ± 0.06)％ and (3.96±0.10)％ in the blank control group,hypoxic group and the 0.01,0.10,1.00,10.00 μmol/L S1P groups,respectively,with a significant difference among the groups (F =25.070,P =0.000).Compared with the hypoxia group,the cellular apoptosis rates of various S1P groups were lower (all at P＜0.05).Conclusions Under the hypoxia condition,S1P can promote the proliferation of human RPE cells and inhibit apoptosis.

Background Several types of cells participate in the formation of proliferative membrane in proliferative retinopathy (PVR),and the proliferation,migration and epithelial-mesenchymal transition (EMT) of retinal pigment epithelium (RPE) cells play an important role.Many studies have confirmed high blood glucose is the basic pathogenesis of diabetic retinopathy (DR).However,whether EMT could be induced in RPE cells under the high glucose condition has not been reported.Objective This study was to investigate the effects of high glucose on the migration and EMT of RPE cells in high glucose culture model in vitro.Methods Human RPE cell line D407 were cultured and passaged in DMEM/F12 medium with 10％ fetal bovine serum,and 6-8 generations of cells were used in experiment.The cells were divided into 3 groups based on different glucose concentrations in medium.The glucose at the final concentration 5.5 mmol/L or 60.0 mmol/L was respectively used in the normal control group or high glucose group,and the DMEM with 5.5 mmol/L glucose and mannitol was used in the hypertonic control group.The migration rate of the cells were detected 0,24,48 and 72 hours after scratching by wound-scratch test.Real-time PCR was used to detect the relative expressions of zonula occludens-1 (ZO-1) and α-smooth muscle actin (α-SMA) in the cells.Results Cultured cells showed a polygon shape with the clear nucleolus and dense arrangement in the normal control group and the hypertonic control group,but the cells were larger and elongated with the lapse of culture time with the indistinct structure and loose arrangement.At 48 hours after scratching,migrating cells were seen in the scratching area,and the scratching area disappeared at 72 hours after scratching in the high glucose group,but the scratching area still was existed in the normal control group or hypertonic control group.The migrating rate of the cells was higher in the high glucose group than that in the normal control group or hypertonic control group,showing total differences among 3 groups and various time points (Fgroup =328.600,P =0.000 ; Ftime =773.270,P=0.000).Compared with the normal control group,the expression level of ZO-1 mRNA was significantly lower,and α-SMA mRNA level was higher 48 hours and 72 hours in the high glucose group than those in the normal control group (all at P＜0.05).Conclusions High glucose induce the migration and EMT of RPE cells in vitro,which may be associated with the pathogenesis of proliferative diabetic retinopathy.

Background Diabetic retinopathy (DR) is one of the common complications of diabetes.Retinal pigment epithelium (RPE) cells,as important constituent cells of the retina,play important roles in the development and progression of DR.Objective This study was to investigate the suppressive effects of autophagy inhibitor 3-MA on the proliferation of human retinal pigment epithelium cells (hRPECs) following high glucose culture.Methods HRPECs were divided into control group,high-glucose group and 3-MA+high glucose group.The cells were cultured by the DMEM/F12 with 5 mmol/L glucose in the control group,and by the DMEM/F12 with 5 mmol/L glucose in the high glucose group and by the DMEM/F12 with 10 mmol/L 3-MA (for 1 hour firstly) and 30 mmol/L glucose in the 3-MA+high glucose group.The cells were inoculated into 24-well plate with the content of 1 ×105/well,and then the cells were consecutively cultured for 24 hours with DMEM/F12 containing 0.5％ fetal bovine serum after achieved attached 80％ confluence.The morphology and uhrastructure of the cells were examined by optics microscope and transmission electronic microscope.The proliferative rate of the cells was assayed by CCK-8 kit.The expression of autophagy-related gene microtubule associated protein light chain 3B (LC3B) in the cells was detected by Western blot and LC3B-Ⅱ/LC3B-Ⅰ value was quantitatively evaluated among the groups.Results The cells grew well with uniform size and regulatory arrangement in the control group.The cells in the high glucose group enlarged and the number of cells evidently increased.In the 3-MA+high glucose group,the cells decreased with a disorder arrangement.Under the transmission electron microscope,the cells were normal with the round-or oval-like nucleus and normal organelles in the control group,and autolysosome could be seen in the cells in the high glucose group.In the 3-MA+high glucose group,some autophagic bodies were found.The proliferative rate of the cells was (100.0±2.0) ％,(116.9-±5.2)％ and (103.7 ±4.7)％ in the control group,high glucose group and 3-MA+high glucose group respectively,showing a significant difference among the groups (F =13.526,P =0.006).The proliferative rate was considerably raised in the high glucose group compared with the control group and 3-MA+high glucose group (both at P＜0.05),but there was no significant difference in the proliferative rate of the cells between the control group and 3-MA+high glucose group (P＞0.05).Compared with the control group,the expressing intensity of LC3B-Ⅰ protein was weakened and that of LC3-Ⅱ protein was enhanced,and the expression intensity of LC3B-Ⅰ and LC3B-Ⅱ proteins in the 3-MA+high glucose group was similar to that in the control group.The LC3-Ⅱ/LC3-Ⅰ ratio was 0.131 ±0.065,2.504±0.097 and 0.274±0.007 in the control group,high glucose group and 3-MA+high glucose group,respectively,with significant differences among the groups (F =1 694.676,P =0.000),and the LC3-Ⅱ/LC3-Ⅰ ratio was increased in the high glucose group in comparison with the control group and the 3-MA+high glucose group (all at P＜0.05).No significant difference was found in the LC3B-Ⅱ/LC3B-Ⅰ ratio between the control group and 3-MA + high glucose group (P ＞ 0.05).Conclusions High glucose culture of hRPECs can activate autophagy process and promote cell proliferation.3-MA,an autophagy inhibitor,suppresses the high glucoseinduced growth of HRPECs by inhibiting autophagy process.