Objactive:To study the color changes of SY-1 silicone elastomer before and after polymerization.Methods:L*a*b*color parameters of 10 samples of SY-1 silicone elastomer were measured with Minolta chroma-ticity instrument(CS-321) before and after polymerization.The color difference(△E) between precure and post-cure was calculated as△E =[(△L)2+(△a)2+(△b)2]1/2.Results:After polymerization L*and a*valueswere increased(P

Objective:To explore the influence of liquid for post-operative irrigation on the effect of ESS.Method:192 cases with chronic sinusitis and/or nasal polyps of groupIIstageII who had undergone the ESS from September,1998 to June,1999 and completed a3-month follow-up were divided randomly into 3 groups to accept 3 different kinds of irrigation liquid.The evaluation of curative effect was according to the index of HaiKou ESS-97.Result:The curative effect of Herba Houttuyniae group was better than the other two.Conclusion:The post-operative care is important and the irrigation liquid can affect the effect of ESS.

Objective To study wether dezocine (DZ) can attenuate neuropathic pain in rats and to investigate its mechanism.Methods Neuropathic pain was induced by tight ligation of the left L5 spinal nerve of the male SD rats. 24 Spinal nerve ligation (SNL) model rats were randomly divided into three groups:the first group (saline group, n=8), rats were given intraperitoneal injection of 1ml of saline 14 days after SNL surgery; the second group (dezocine group, n=8), rats were given intraperitoneal injection of 5mg/kg of dezocine in 1ml saline 14 days after SNL surgery;the third group (morphine group,n=8),rats were given intraperitoneal injection of 5 mg/kg of morphine 14 days after SNL surgery. Results Intraperitoneal injection dezocine and morphine had significant analgesic effect in neuropathic pain rats. This analgesic effect lasted for 4-6 hours.Continuous injection of morphine for 3 days produced significant tolerance, while continuous injection of dezocine for 7 days still had significant analgesic effect on neuropathic pain. Conclusion Intraperitoneal injection of dezocine and morphine can attenuate SNL neuropathic pain, continuous injection of morphine for 3 days can produce significant tolerance, while continuous injection of dezocine for 7 days still has significant analgesic effect on neuropathic pain.

Objective To apply the techniques of CAD/CAM in the repair of defects and correction of deformity on the jaw bones so as to improve the accuracy and controllability of operations.Methods With CAD techniques,3D bone model was reconstructed based on CT images.Then,a repairing model was created with mirror operation on original model.The physical models of original model and repairing model were fabricated through rapid prototyping.Based on physical models,operation plan and model surgery with pre-forming plate could be designed.Results The designed operation plan and pre-forming plate techniques of CAD/CAM were successfully applied in eight patients,with satisfactory results.Conclusions With techniques of CAD/CAM,reconstructing and fabricating the original bone model and mirror repair model are very helpful for designing operation plan for maxillofacial surgery.It also can improve the surgery accuracy and save operation time obviously.

OBJECTIVE To improve the knowledge on the early diagnosis and treatment of the isolated fungus ball sphenoid sinusitis.METHODS A retrospe ctive study was made on10cases of isolated fungus ball sphenoid sinusitis to discuss the clinical manifestation,radiographic features and treatment with endoscopic sinus surgery.RESULTS The common symptoms in10cases were headache and/or bloody nasal discharge.Radiographic features of the disease were a soft tissue image occupying the sphenoid sinus with bones wall thickening.A soft tissue image with calcification in the sphenoid sinus was the feature of CT image.All the patients were treated by nasal endoscopic sinus surgery and cured after followed up for3to18.CONCLUSION Isolated fungus ball sphenoid sinusitis was difficult to diagnose in early stage because of its non-specif ic symptoms.The nasal endoscopy and CT scan make the early diagnosis possible.The diagnosis can be def initely confi rmed by pathological studies.Treatment with endoscopic sinus surgery is an effective method for fungus ball sphenoid sinusitis.

Objective To evaluate the teaching activity on public health courses from clinical medical students in our university in order to provide a scientific basis for improving the curriculum design and teaching reform. Methods The “Questionnaire on Teaching Evaluation in Public Health Courses”, including teaching attitude, teaching content, teaching methods and teaching effectiveness was designed, and a general investigation was conducted among the clinical medical students of five-year program (840 students) and eight-year program (278 students) in these three aspects to under-stand students' evaluation to the course, who had finished the public health courses, including Preven-tive Medicine, Medical Statistics and Epidemiology (hereinafter referred to as: statistics, epidemiology, prevention) in Sun Yat-sen University. Statistical analysis was made using SPSS 13.0 software. Data analysis methods contain descriptive analysis, T-test, ANOVA, LSD, SNK, hierarchical logistic regres-sion analysis, etc. Results The overall score of teaching evaluation is (4.04±0.60). Differences exist between the evaluation in the five-year medical students and the eight-year medical students. The P values were 0.000 (Medical Statistics), 0.269 (Epidemiology), 0.047 (Preventive Medicine). The com-parison of scores among the four dimensions shows: Teaching effectiveness < Teaching methods β' effectiveness. Conclusions Clinical Medical students' overall evaluation on the public health courses offered by this university was good. Teaching effectiveness and teaching methods still need improvement. Teaching contents are the most influential factor of overall teaching satisfaction, followed by teaching effectiveness.

Objective:To evaluate the influence of delayed application of mixed self-etching bonding agent on the tensile bond strength.Methods:Two "two-bottle,one-step" self-etching adhesives,Adper Prompt and Xeno III,were evaluated.The occlusal enamel of human third molar was cut out and the exposed dentin surface was divided in two halves by a 1 mm deep groove in the labial-lingual orientation to allow for evaluation of immediate application and delayed application(0.5,1,2,3,4,5 and 6 h) of mixed self-etching bonding agent in the same specimen,followed by composite resin built-up on the adhesive.The bonded specimens were sectioned into beams of approximately 0.9 mm2 and subsequently subjected to micro-tensile bond strength testing at a crosshead speed of 1.0 mm/min.Results:The specimens bonded with the Adper Prompt within 5 h after mixing showed no different and that with the Xeno III within 3 h after mixing showed no different.Conclusion:The effective period for "two-bottle,one-step" self-etching adhesives after mixing is limited.Different bonding agents have different effective periods.

Objective To study 18F-deoxyglucose-positron emission tomography and CT fusion (FDG PET) in three dimensional conformal radiotherapy for non-small -c ell lung carcinoma (NSCLC). Methods Gross tumor volume (GTV) of 13 NSCLC patient s were determined by FDG PET and CT separately (GTV PET-CT and GTV CT ), which were then compared. Results Except 2 patients, all the other patients' GTV PET-CT dif fered from their GTV CT. Compared with GTV CT, GTV PET-CT was in creased by an avera ge of 29.2?cm3 in 5 patients and decreased by an average of 41.6?cm3 in 6 patien ts. Conclusions 18F-deoxyglucose-positron emission tomography, which can improve target definition between benign and malignant lesions in the lung, is proved t o be more sensitive and specific in detecting mediastinal lymph node involvement . FDG PET may provide accurate target definition and improve the local control.

Objective: To study the effects of the melt casting and the sintering methods on the machinability and other characteristics of K_2O-MgO-MgF_2-SiO_2 glass-ceramics. Methods: X-ray diffraction(XRD) and scanning electron microscopy (SEM)were used to examine the main crystal and the microstructure of the glass ceramics of the same composition which were made by melt casting and sintering methods, respectively. The transmissivity, flexural strength and brittleness index were observed respectively. Results: The glass ceramics made by two different methods have the same crystal, KMg_(2.5)Si_4O_(10)F_2, while the specimen prepared by the sintering method had lower transmissivity,better machinability and mechanical properties due to the higher mica volume percent. Conclusion; For production of fluoro-mica glass ceramics, sintering method has superiority compared to melt-casting method.

Post-polio syndrome involves a variety of clinical manifestations, which need multi-dimensional evaluation measurement. Multi-dimensional Fatigue Inventory (MFI-20), muscle strength testing, laboratory test, imaging study, the sleep quality assessment, electro-physiological test, pain score, functional independence measure, moving obstacles evaluation, physical activity situation, walking ability as-sessment, the Medical Outcomes Study health survey short form, and evaluation of mental health scale are in common use in the studies.