Objective: To investigate the inhibitory effect of Flu or Protector on the demineralization of bovine enamel caused by some beverages. Methods: Forty bovine teeth were equally divided into experimental and control groups, each of them were subdivided into two groups. The enamel sp ecimens of the experimental group were pretreated with Fluor Protector and then exposed to carbonated drinks and fruit juice respectively,the enamel specimens o f control group were exposed to beverages directly. All the enamel specimens wer e exposed to beverages 5 times a day and for 5 minutes each time. After 7- day exposure,the concentration of calcium and phosphate in the beverages were measu red by EL 312e Micro-Plate. Results: The concentration of calci um and phosphate in the corresponding beverage of experimental group was lower t han that in control group in the same expossure time(P0.05).Conclusions: Fluor Protector can inhibit the demineralization of bovin e enamel caused by beverages.The inhibitory effect of Fluor Protector decreases as the exposure time prolonges.

Objective To explore the value of diffused optical tomography(DOT)with ultrasonography (US)in differential diagnosis of breast benign from malignant neoplasms.Methods One hundred ard twenty-three breast neoplasms from 113 patients were checked use the optical tomography image ultrasonography(OPTIMUS).The diagnosis results of the system were compared with pathological study.Two-dimensional ultrasound features in breast neoplasms were digitalizated,and HBT and SO_2 were detected by DOT.At last,synthesis diagnostic index(SDI)was obtained by both US and DOT.Statistic process was carried out in sensitivity,specificity,and the rate of accuracy respectively by US,DOT and OPTIMUS system.Results Among breast neoplasms of 123 mass studied pathologically,78 of them were benign and the rest were malignant.HBT in benign lesions(153.02±105.78)was significantly less than malignant lesions(232.95±78.22),SO_2 in benign lesions(1.0332±0.1641)was significantly elevated compared with malignant lesions(0.8794±0.1814),SDI in benign lesions(147.26±53.76)was significantly less than malignant lesions(243.98±57.27),significant differences were found between the two groups(P＜0.05).The sensitivity of differential diagnosis of breast neoplasms by the OPTIMUS system was 93.33%,the specificity was 83.33%,and the rate of accuracy was 86.99%.Conclusions OPTIMUS can improve the specificity and the rate of early diagnosis.

Objective To investigate the differences of pre-hospital delay time in acute ST-elevation myocardial infarction (STEMI)between the advanced age group(>75 years old)and control group(≤75 years old).Methods Four hundreds patients with STEMI in the cardiology and emergency departments of the First Affiliated Hospital and Affiliated Luoyang Central Hospital of Zhengzhou University from January 2013 to March 2015 were selected and divided into two groups according to the age,the ad-vanced age group (>75 years old)and control group(≤75 years old).The patients′data were inquired and recorded for conducting the statistical analysis.Results The proportion of pre-hospital delay time < 6 h in the advanced age group was significantly lower than that in the control group and the time for conducting coronary angiography was longer than that in the control group,the differences were statistically significant(P <0.05).The mortality rates of intra-hospital,on 30 d and half a year after discharge in the advanced age group were higher than those in the control group,the differences between the two groups were statistically signif-icant (P <0.05).Conclusion The advanced age patients receiving active therapy are relatively less,which is mainly due to the wor-ry on the age related adverse reactions.

Objective To analyze the effects of Cavity Preparation Skill Evaluation System (CPSES) in pre-clinical dental cavity preparation assessment.Methods Twenty one dental undergraduates in Medical School of Nankai University were chosen in this study.After cavity preparation training,students' cavity preparation skills were evaluated systematically.The outline form and depth of 21 left mandibular first molar class Ⅰ cavity preparation made by students were evaluated by CPSES system and evaluators' visual assessment.The evaluation results were analyzed using GraphPad InStat statistical software(V3.1) with paired t test (test level α=0.05) and correlation analysis to study the application effects of the CPSES system.Results The evaluation results generated from CPSES system and evaluators' visual assessment for class Ⅰ dental cavity preparation skill evaluation showed significant difference(two tailed P value 0.0050,t=3.156) and certain correlation on cavity preparation assessment(two tailed P value 0.0837,r=0.386 2).Conclusion Application of cavity preparation skill evaluation system in undergraduate endodontic teaching can deepen and strengthen the students' understanding of cavity preparation requirements and help students master cavity preparation knowledge and skills better.

Objective To investigate MR findings and dynamic changes of the brain after gas explosion,and to evaluate the relationship between MR findings and post-traumatic stress disorder (PTSD).Methods Forty-nine survivors of a gas explosion (group A) were examined with brain MRI within 1 to 3 days,and serial MR follow-up examinations were also performed.Forty miners not under the ground that day were assigned as group B,and 40 staff working on the ground as group C.The signal intensity values of hippocampus and globus pallidus on T2WI were measured in the three groups and F test was performed by using SPSS 13.0.The relationship between signal intensity values of hippocampus/globns pallidus and PTSD was explored,and the relationship between ADC values of hippocampus and PTSD was also investigated.Results In group A,slight low signal on T1WI and high signal on T2WI were detected on initial MRI in hippocampus (33 cases),globus pallidus (12 cases),cortex (10 cases),and midbrain (2 cases),respectively.On follow-up MRI at 2 months,lesions in hippocampus disappeared (25 cases) or remained slight high signal on T2WI (8 cases),lesions in globus pallidus disappeared (3 cases,5 sides) or showed shrinkage and encephalomalacia (9 cases),cortical lesions resulted in encephalomalacia in 2 cases and returned normal in the others,and lesions in the midbrain showed encephalomatacia.For comparison of T2 signal intensity values in hippocampus and globus pallidus,there was significant difference between group A and group B(P <0.01),and also between group A and group C(P <0.01),but no difference was detected between group B and group C (P>0.05).In group A,the T2 signal intensities of PTSD and non-PTSD were 455±37 and 462±53 in the left hippocarnpus,and 458±36 and 460±43 in the right hippoeampus on 1 to 3 days,and the T2 signal intensities of PTSD and non-PTSD were 438±29 and 424±37 in the left hippocampns,and 442±31 and 430±32 in the right hippocampus at 2 months.The T2 signal intensities of PTSD and non-PTSD were 361 ±35 and 366±63 in the left globus pallidus,and 363 ±41 and 375±62 in the right globus pallidus on 1 to 3 days,and the T2 signal intensities of PTSD and non-PTSD were 341±24 and 337±39 in the left globns pallidus,340±26 and 332±35 in the tight glohus pallidns at 2 months.There was no difference of T2 signal intensity values in hippocampus and globus pallidus between PTSD and non-PTSD( t=0.350,0.826,0.503,0.907,P>0.05).In group A,ADC values of PTSD and nun-PTSD were (8.1±1.1)×10-4 and(8.1 ±0.9)×10-4mm2/s in the left hippocampus,and (8.2±1.0)×10-4 and(8.2±0.8)×10-4mm2/s in the tight hippocampus on 1 to 3 days,ADC values were (8.8±0.7)×10-4 and (9.0±1.0)×10-4mm2/s in the left hippocampus,and (8.5±0.9)×10-4 and (9.3±1.1)×10-4mm2/s in the tight hippocampus at 2 months.ADC values in hippocampns showed no difference between PTSD and non-PTSD(t=0.016,0.081,P>0.05)on initial MRI,but showed significant difference between PTSD and non-PTSD in tight hippocampus (t=7.407,P < 0.05) on follow-up MRI at 2 months,while no difference in left hippocampus (t =0.333,P>0.05) was observed at 2 months.Conclusion Hippocampns and globus pallidus are the most vulnerable structures in gas explosion.The occurrence of PTSD may be related to the injury of fight hippocampus,but not related to the injury of globns pallidus.

OBJECTIVETo evaluate the outcome of endodontic microsurgery in 54 cases with persistent apical periodontitis.

METHODSAll surgical procedures were performed under a dental operating microscope after root canal treatment. Surgical procedures included periapical curettage, root-end resection, retropreparation with ultrasonic microtips, and root-end filling with mineral trioxide aggregate (MTA). Healing was monitored clinically and radiographically.

RESULTSOne year later, 31 (57.41%) cases were cured, 19 (35.19%) cases were improved, 4 (7.41%) cases were failure. There were no statistical difference between sex, age, tooth location, size of the lesion and pathological features (P>0.05).

CONCLUSIONThe outcome of the present study indicates that endodontic microsurgery may result in a predictable treatment outcome in teeth with persistent periradicular lesions.

Aluminum Compounds ; Apicoectomy ; Calcium Compounds ; Drug Combinations ; Humans ; Microsurgery ; Oxides ; Periapical Periodontitis ; Root Canal Filling Materials ; Root Canal Obturation ; Root Canal Therapy ; Silicates ; Treatment Outcome