BACKGROUND:The strength of al-ceramic crowns is affected by many factors. At present there are many studies concerning the neck edge shape, cutting thickness, binder and convergence angle, but little has been reported on the effects of different occlusions on al-ceramic crowns. OBJECTIVE:To explore the maxilary central incisor al-ceramic crowns in different occlusal states by finite element analysis. METHODS: Three-dimensional finite element models of the maxilary central incisor al-ceramic crowns were established. Empress II and In-Ceram Zirconia were selected. The normal overbite position and deep overbite position were applied to force a load of 230 N, with the long axis of the tooth at a 45° angle. Distribution of inner stress and edge stress was analyzed at different occlusal states. RESULTS AND CONCLUSION:(1) The stress distribution of al-ceramic crowns under different occlusion relationship was different. The stress peaks of cementum, alveolar bone and periodontium in the deep overbite were lower than those in the normal overbite. The stress peaks of al-ceramic crowns and binder were higher than in the deep overbite than the normal overbite. The stress peak of the dentin in the Empress II group was higher in the deep overbite than in the normal overbite. The stress peak of the dentin in the In-Ceram Zirconia group was lower in the deep overbite than in the normal overbite. Different al-ceramic crowns had no influence on the stress distribution, but in the deep overbite, the stress was mainly concentrated in the occlusal contact area, and in the normal overbite, the stress was mainly concentrated in the occlusal contact area and at the labial cervical margin. (2) The stress distribution of different al-ceramic crowns under the same occlusal state was different. In the normal overbite, different al-ceramic crowns had no evident influence on the stress peak, and in the deep overbite, there was a certain effect of different al-ceramic crowns on the stress peak, but there was no significant difference. The stress peaks of blinder and dentin were obviously affected by al-ceramic crowns. The stress peaks of blinder and dentin in Empress II group were higher than those in the In-Ceram Zirconia group.

ObjectiveTo evaluate the reliability and validity of Chinese version of Asia-Pacific functional gastrointestinal disorders (FGIDs) questionnaire. Methods The standardized scale translation program was used to translate the Asia-Pacific functional gastrointestinal disorders questionnaire into Chinese version.From April to May 2011,the functional gastrointestinal disorders (FGID) out-patients of the Department of Gastroenterology at the First Affiliated Hospital of Sun Yat-Sen University were asked to complete the Chinese version of the questionnaire,then the feasibility,reliability and validity of the questionnaire were evaluated.ResultsA total of 58 FGIDs patients finished the questionnaire,of which 37 patients with good compliance finished the 2-week interval questionnaire.The retest reliability of the first part of the questionnaire was good (including basic information,disease duration and alarm symptoms),all the test-retest coefficients were more than 0.70.The percentage of poor,medium and good retest reliability items of the second part of the questionnaire (including the symptoms of gastrointestinal system) was 27.8％,61.1％ and 11.1％respectively.After the data was transformed into binary data according to Rome Ⅲ diagnostic criteria,the percentage of poor,medium and good retest reliability items was 5.5％,41.7％ and 52.8％respectively.The percentage of poor,medium and good retest reliability items of the third part of the questionnaire (including previous medical treatment,medication and the impact of the disease on life,etc) was 36.0％,40.0％ and 24.0％ respectively.The validity of the questionnaire was moderate according to the Rome Ⅲ diagnostic criteria.Conclusion The Chinese version of Asia-Pacific functional gastrointestinal disorders is feasible and can be used to screen the adult FGIDs under the Chinese cultural background.

? AlM: To analyze the reason of corneal epithelial implantation and ingrowth after laser in situ keratomileusis ( LASlK ) , and summarize the treatment experiences.
?METHODS: The clinical data of postoperative corneal epithelial ingrowth on 18 cases (30 eyes) from 1 256 cases (2 256 eyes) after LASlK were retrospectively analyzed in our hospital from January 2008 to December 2012. After the treatment of all eyes, patients’ general visual quality scores before and after treatment were analyzed.
?RESULTS:There were 18 cases ( 30 eyes ) with corneal epithelial implantation and ingrowth after LASlK, and the incidence rate was 1. 3%. ln the 18 cases (30 eyes), there were 12 eyes corneal flap epithelial ingrowth caused by postoperative trauma, 12 eyes caused by multiple corneal flap flush, 2 eyes caused by intraoperative irregular corneal flap, and nothing special for 4 eyes. The classification of corneal epithelial ingrowth of 30 eyes:grade I, 11 cases (18 eyes);gradeII, 4 cases (8 eyes);grade Ⅲ, 3 cases ( 4 eyes ) . Grade I-II were treated with TobraDex eye drops and intraocular pressure lowering drug. Grade Ⅲ firstly were treated by drugs, otherwise by surgery if it didn’t improve. After treatment, 8 cases (13 eyes) epithelial ingrowth disappeared from 11 cases ( 18 eyes ) , 3 cases ( 5 eyes ) implanted epithelial tumor shrank in grade l;epithelial implantation of 2 cases (4 eyes) in grade II disappeared, implantation degree of 2 cases (4 eyes) reduced to grade I;2 cases (2 eyes) in grade Ⅲ had 0. 5 ~ 1mm wide flap edge shallow gray ribbon 1 mm inside the limbus, visual acuity was 0. 8 ~1. 2, 1 case ( 2 eyes ) treated with curettage corneal epithelial implantation and endophytic epithelium hadn’t relapsed in the follow-up. After the treatment, 18 cases of corneal epithelial ingrowth got lower visual quality scores than those before therapy (Hc=10. 511, P<0. 01).
?CONCLUSlON: Operation standardized, postoperative early detection and aggressive treatment are important for prevention and treatment of complications after LASlK.

Objective To evaluate the application value of focused assessment with sonography for trauma (FAST) in treatment of emergency thoracic and abdominal closed injury.Methods FAST examination was performed in 85 patients with thoracic and abdominal closed injury,to determine whether the thoracic and abdominal cavity,pericardial free effusion and abdominal parenchyma organ injury,and the results were compared with conventional ultrasonography,CT scan and operation results.Results FAST was (2.85 ± 1.15) min,conventional ultrasonography was (15.48 ±5.17) min,there was statistically significant difference (t =21.99,P ＜ 0.05).In 85 patients,10 cases were FAST positive,5 cases of abdominal cavity in that amount or a large number of free effusion,underwent emergency operation,postoperative intra abdominal parenchymal organs were confirmed as rupture and hemoperitoneum; 2 cases of renal rupture with perirenal hematoma,confirmed by the whole abdominal CT examination; 2 cases of thoracic free pneumatosis,effusion,confirmed by thoracic CT examination or closed thoracic drainage; 1 case of prompt hemopericardium,confirmed by the pericardium puncture.Conventional ultrasonography was positive in 11 patients,no statistically significant difference between them (P ＞ 0.05).The sensitivity,specificity,accuracy rate of FAST screening thoracic and abdominal closed injury was 10/12,100.0％ (73/73),97.6％ (83/85).Conclusions FAST has high sensitivity and specificity for thoracic and abdominal cavity,pericardial free effusion,check with short time,low environmental requirements,without moving the trauma patients,and may be out of sync with the fluid resuscitation and other emergency measures.For large quantities of trauma patients and patients with severe multiple trauma,FAST can quickly,accurately determine the existence of thoracic and abdominal closed injury,and provide guidance for clinical treatment,which has good application value.

Under the shaking-flask culture, fermentation medium of honggumycin produced by Streptomyces 702 were studied.The experiment was used response surface methodology to optimize the shaking-flask fermentation medium.Firstly, we applied full factorial design to screen important factors soybean meal and industrial peptone which affected hongmycin produced by Streptomyces 702.Furthermore, we designed experiment to obtain the steepest ascent path and optimal level by the central composite design.The optimum medium consisted of (g/L): maize starch 20, maize meal 20, glucose 20, soybean meal 23, industrial peptone 9, KNO_ 3 2.5, (NH_ 4 )_ 2 SO_ 4 2.5 KH_ 2 PO_ 4 0.3, NaCl 3, CaCO_ 3 6, bean oil 5mL/L.Under the optimal medium, the yield of honggumycin was up to 1500 g/mL, which was increased by 308% than the original medium.

AIM:Receptor tyrosine kinase (RTK) activation is critical for growth factor-mediated cell proliferation. The present study was designed to determine the effect of the tyrphostin AG1295 and AG1296, a selective blocker of PDGF βand αRTK,on proliferative vitreoretinopathy (PVR) development.METHODS:Rabbit conjunctival fibroblasts (RCF) cells were cultured.The effects of AG1295, AG1296,PDGF-AA and PDGF-BB on RCF proliferation are evaluated by MTT assay.Homologous rabbit conjunctival fibroblasts were injected intravitreally to make animal PVR model, followed by injection of 100μmol/L of AG1295 or AG1296 respectively. The presence of tractional retinal detachment (TRD) was assessed to evaluate the effect of AG1295 and AG1296 in vivo .Electroretinography and histologic studies were performed after intravitreal injection of AG1295 into untreated eyes to evaluate toxicity. RESULTS: Both AG1295 and AG1296 (10μmol/L) significantly inhibited rabbit conjunctival fibroblast cell growth stimulated by PDGF-AA or -BB in vitro.Development of TRD was significantly reduced (P<0.05) with 100 μmol/L of AG1295 or AG1296 in vivo, but the effect of AG1295 only present till day 14. Inhibitive effect of AG1296 is longer than that of AG1295.No significant histologic or retinal functional damage was found in both drug-treated groups. CONCLUSION: PDGF αand βreceptor specific inhibitor AG1296 and AG1295 attenuated PVR without significant side effects in rabbits, and AG1296 was better than AG1295. The much longer and stronger therapeutic effect from PDGFαreceptor inhibitor indicated that PDGF α receptor is more important in the development of PVR, and inhibition of this pathway could be a useful treatment alternative to prevent PVR.

The discovery of microRNAs (miRNAs) has introduced a new paradigm into gene regulatory systems. Since inception, computational methods have been an invaluable tool complementing experimental approaches, and many discoveries have been obtained through combination of experimental and computational approaches. The knowledge that has been accumulated about the principles of miRNAs and target recognition were reviewed. The currently available computational methodologies and software for prediction of miRNA and their target genes also have been discussed.

OBJECTIVE: To study the relationship between the postmortem interval (PMI) and the changes of DNA content in rabbit's cornea epithelial and endothelium. METHODS: Using the computerized image analysis to measure the DNA content in the cornea epithelial and endothelium of 105 rabbit's at every six hours during 72 hours after death. RESULTS: The degradation rate of DNA in nuclear has an apparent relationship in 72 hours after death of the rabbits. CONCLUSION The determination of the quantity of DNA in cornea nuclear is a new method to estimate the PMI accurately.
Animals ; DNA/analysis* ; Endothelium, Corneal/chemistry* ; Epithelium, Corneal/chemistry* ; Female ; Forensic Medicine ; Male ; Postmortem Changes ; Rabbits ; Signal Processing, Computer-Assisted ; Time Factors

Objective To evaluate the clinical training outcomes from two clinical practice modes for undergraduate students. Methods Total two grades 2009 and 2010,150 undergraduate students were randomly divided into two groups: 69 students in group A and 81 students in group B. The synthetic teaching mode was applied in group A,and group B received the traditional teaching mode. The Objective Structure Clinical Examination (OSCE)and a written comprehensive examination were used to evaluate the training outcomes by T test analyzed by SPSS 17.0(α= 0.05). Results The theoretical level of 2009 grade students was better than that of 2010 grade (P < 0.05). The clinical practice skills of the two groups had no significant difference(P > 0.05). There were no significant differences between two groups in theoretical and clinical training(P > 0.05). Comparing with the 2010 grade,the theoretical level of the 2009 was better,but the clinical skill level was weaker. Conclusion Synthetic teaching mode and traditional teaching mode both achieved good outcomes. In order to obtain better comprehensive progresses,the two teaching modes need to be combined. The orientation by following the requirements of oral practicing qualification examination may enhance the clinical skills of the students.

Objective To provide information support for military medical service drilling with actual arms in field medical clinic. Methods The local netwok was built based on Intranet mode for military medical service. A distributed wartime military medical service information system was developed. The long-range consultation was carried through a consultation vehicle. The field medical clinic information system was integrated with No.1 Military Medical Project. Results The system has been used in drilling with actual arms of field medical clinic for three years. Conclusion The result shows that the system can satisfy the need of information management of field medical clinic and enhanced the efficiency of management greatly.