The teaching model in classroom is a popular process of language communication between teachers and students.There is a paradox phenomenon in asking and interlocution due to tergiversalion ofthe original intention ofthe teaching.So,it is an important thing that the teaching model should be transferred from asking to interlocution to establish equal right,enhance understanding and decrease undesirable manners.

Objective To probe CT grading criteria of vascular invasion in pancreatic cancer.Methods Retrieved articles in CNKI and PubMed about value of CT in preoperative assessment of vascular invasion in pancreatic cancer last ten years.Results Multislice helical CT is considered the best imaging method to assess the invaded peripancreatic vessels in pancreatic cancer.There are different CT criteria of vascular invasion in pancreatic cancer based on extension of hypodense tumor and its relation to blood vessels,on the degree of circumferential contiguity of tumor to vessel,on the degree of lumen stenosis,and on the degree of contiguity between tumor and vessels combined vascular caliber.Conclusion CT grading criteria are not uniform,each one has defects.

Objective :To explore the behavior characters of children diagnosed as ODD with ADHD symptoms. Methods: The diagnosis of ODD was made according to the ICD-10 criteria . 40 Children having ODD with ADHD symptoms (combined group ) and 22 Children having ODD but without ADHD symptoms (ODD group) were collected from outclinics. The parents of all subjects completed Achenbach Child Behavior Checklist (CBCL) and a family information list. Results: The onset and help-seeking age of the combined group were younger than that of ODD group. They had more disobey, attacking, and extroversive behaviors. Their fathers were more agitative. Parents of the combined group used more beating and scolding in parenting. Conclusion: ODD children with ADHD symptoms had more behavior problems and incur worse parenting style. Their family need more help in early age.

Objective:To research the risk factors of developing Oppositional Defiant Disorder (ODD).Methods:Among 427 students in an elementary school in Changsha, we screened out thirty-four children with ODD by the criteria of DSM-IV. They and other thirty-four normal children from the same school were included in the case-control study. Education levels, jobs and Cartel 16 Personality Factors (16PF) were filled out by their parents. Combined Raven's Test (CRT) was used to evaluate children's intelligence.Results:The prevalence rate of ODD in children increased with the decrease of their father's and mother's education level (for father's education level form advanced education, secondary education to primary, the rate increased from 6.6%,7.2% to 12.0%) and (for mother, 5.3%,7.5%,10.6%). The rate of ODD was highest in children with father and mother doing small business (16.7% and 16.5%, ?~2=12.67～12.68,P

Objective To observe the effects of therapy of supplementing spleen to strengthen lung on patients with adenomatous colonic polyps (ACP) after endoscopic removal . Methods One hundred ACP patients with spleen deficiency and dampness blended with blood stasis were randomly divided into 2 groups after endoscopic removal, 50 cases in the treatment group and 50 cases in the control group. Both groups were treated with diet and behavioral therapy, and the treatment group was simultaneously given oral use of modified Shen Ling Baizhu Powder plus self-moxibustion of bilateral acupoint Zusanli point. After treatment for 6 months and 1.5 years, all of the patients were asked to do the examination of colonoscopy, body mass, body mass index (BMI), and triglyceride (TG). Results (1) After treatment, the mean overall symptom scores of the two groups were improved (P < 0.01 compared with those before treatment) , and the improvement of the treatment group was superior to that of the control group(P < 0.01).(2) After treatment for 6 months and 1.5 years, the recurrence rate of ACP in the treatment group was lower than that in the control group(P < 0.05).(3) After treatment for 6 months and 1.5 years, the body mass, BMI and TG of the treatment group were significantly different from those before treatment(P<0.05), while the control group showed no significant changes(P > 0.05). The effect of the treatment group on improving body mass, BMI and TG was better than that of the control group (P < 0.05). Conclusion The therapy of supplementing spleen to strengthen lung is effective on relieving symptoms of ACP patients, and also has an effect on decreasing BMI and TG as well as the recurrence of ACP after endoscopic removal.

Objective To discuss the clinical characteristics,treatment and prognostic factors of brain metastasis from gynecological cancers.Methods Clinical records of 25 brain metastasis patients from gynecological cancers admitted from January 1999 to January 2009 were reviewed retrospectively.The curative effects of different treatments were compared.The prognostic factors were determined using the Cox regression model.Results There were 14 cases ovarian malignant tumor,6 cases cervical carcinoma and 5 cases uterine malignant tumor.Seven cases (28％,7/25 ) had solitary metastatic lesion in the brain.Extracranial metastases were detected in 18 cases (72％,18/25 ).Five patients only received one kind of treatment,and the mean survival time was 4.0 months (0.5 to 9.5 months).Sixteen patients received combined treatment,3 of them received combined treatment including surgery,and the mean survival time was 8.4 months (4.1 to 13.4 months) ; 13 of them received chemotherapy and radiotherapy,and the mean survival time was 14.2 months (4.3 to 58.1 months).Four patients received only palliative supportive care,and the survival time was only 0.1 to 1.0 month.The Cox regression model showed that Karnofsky performance status scale,with or without extracranial metastases and the treatment method were the independent prognostic factors of brain metastasis from gynecological cancers ( P ＜ 0.05 ).Conclusion The incidence of brain metastasis from gynecological cancers is low and the prognosis is very poor.Combined treatments may get better effects.

Objective To evaluate the accuracy of image registration based on bony structure (RBS) and grey-scale (RGS) in positioning correction of radiation treatment,and their reliability in clinical application.Methods Setup errors of anthropomorphic phantom (chest& abdomen,head& neck) were simulated with x-,y-,z-directions.CBCT images were acquired for each simulation and registered with planning CT.using bony structure and grey-scale registration separately.Geometry accuracy of all registration were then obtained and analyzed.Results The errors of RBS and RGS in x-,y-,z-directions were (-0.65 ±0.22) mm and (-0.70±0.17) mm (P=0.00),(1.02 ±0.27) mm and (0.90±0.20) mm (P =0.00),(1.46 ± 0.53) mm and (1.47 ± 0.47) mm (P =0.54) for head& neck positioning; with (0.82±0.33) mm and (0.79±0.18) mm (P=0.03),(2.45±1.17) mm and (1.61 ±0.84) mm (P =0.00),(1.44 ± 3.25) mm and (0.19 ± 1.11) mm (P =0.00) for chest& abdomen positioning.Conclusions RGS is more accurate and stable than RBS.The accuracy of image registration is a little better for head& neck than that for chest& abdomen.The algorithms of image registration used in clinical application needs to be tested independently and the systematic error needs to be corrected before applying in different treatment techniques according to their accuracy requirement.

Objective To evaluate the impacts of slice thickness and registration frame range on the accuracy of cone-beam computed tomography ( CBCT) image-guided head and neck ( HN) radiotherapy, and to provide a basis for positioning correction in image-guided radiotherapy.Methods A planned CT scan was performed for an anthropomorphic HN phantom with slice thickness of 1 mm and 3 mm and simulated positioning errors in x, y, and z directions on the accelerator.CBCT scan and reconstruction were performed with slice thickness of 1 mm and 3 mm.Two different registration frame ranges were used ( range 1:from C7 to superior orbit;range 2:from C7 to calvaria ) .Automatic bony registration was performed for CBCT and planned CT images with slice thickness of 1 mm and 3 mm.The registration accuracy was evaluated.Results For range 1, the registration errors in x, y, and z directions with a slice thickness of 1 mm were significantly lower than those with a slice thickness of 3 mm (0.5±0.2 mm vs.-0.7±0.2 mm, P=0.00;0.5±0.3 mm vs. 1.0±0.3 mm, P=0.00;-0.1±0.5 mm vs.1.5±0.5 mm, P=0.00).For range 2, the registration errors in x, y, and z directions with a slice thickness of 3 mm were-0.4±0.2 mm, 0.5±0.2 mm, and 0.7±0.4 mm, respectively.Conclusions Engagement of calvaria in registration range can substantially enhance the registration accuracy in CBCT or CT images for HN.The registration error with slice thickness of 1 mm can be controlled within 1 mm.

OBJECTIVE To explore the protective effect of polysaccharides from Salvia Chinensis Benth. (PSSC) on lipopolysaccharide (LPS) and D- galactosamine (GalN)- provoked mouse acute liver failure (ALF) and the possible molecular mechanism. METHODS Kunming mice were randomly divided into four groups: normal control, model, model+PSSC 30 and 100 mg·kg- 1 groups. PSCC was given once a day and for a week. To establish an ALF model, mice of model and PSSC groups were ip injected with LPS 10 μg·kg-1 and GalN 700 mg·kg-1 at the end of PSSC treatment. The microscopic structure of the liver was detected by HE staining. Serum and hepatic biochemical parameters of glutamic-oxalacetic transaminase (GOT), glutamic- pyruvic transaminase (GPT), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and glutathione (GSH) were detected by colorimetric methods. The relative content of hepatic reactive oxygen species (ROS) was measured by DCFH-DA fluorescent probes. Levels of cytokines tumor necrosis factor-α (TNF-α), interleukin 1β(IL-1β) and IL- 6 in the serum and liver were detected by ELISA. Activity of caspase 3 in liver homogenates was detected by aspase 3 activity assay kit. RESULTS Compared with normal control group, in the liver of model group, hepatocytes were arrayed in disorder, cytoplasm of hepatocytes shrank, and boundaries between cells were fuzzy, the infiltration of a large number of inflammatory cells and tissue hemorrhage could be detected, pathological scores were elevated significantly (P<0.01), levels of MDA and ROS in the liver of ALF model mice were elevated to 2.2 and 4.3 times that of the normal control, respectively (P<0.01), the level of GSH decreased to 51% (P<0.01), and the activities of SOD, CAT and GSH- Px declined to 74%, 36% and 42%, respectively (P<0.01). Levels of TNF- α, IL- 1β and IL- 6 in the serum and liver of model group were increased (P<0.01), and caspase 3 activity was increased to 5.3 times that of the normal control (P<0.01). Compared with the model group, the number of surviving mice in PSSC groups increased, liver pathological scores declined (P<0.01), levels of MDA and ROS increased (P<0.01), levels of GSH, TNF-α, IL-1β and IL-6 in the liver and serum declined (P<0.01), and caspase 3 activity decreased (P<0.01). CONCLUSION PSSC is able to alleviate LPS and GalN-induced ALF in mice. Inhibition of hepatic oxidative stress, inflammatory response, and cell apoptosis is possibly implicated in the protective effect of PSSC.

Objective To study the dosimetric characteristics of flattened and flattening filter free (FFF) beams with 6 MV and 10 MV photon energy using a novel dual-energy medical linear accelerator (Elekta Versa HDTM),to identify the dosimetric characteristics and advantages of FFF beams,and to provide a basis for their clinical application.Methods The percentage depth dose (PDD),profiles/dose rate of off-axis ratio (OAR),field size,penumbral width,dose out of the fields,collimator scatter factor (Sc),and total scatter factor (Sc,p) were compared between flattened and FFF beams.Results (1) After beam energy matching,the FFF beams had the same beam energy with the flattened beams.The matching error of PDD at a depth of 10 cm was less than 1％ between fields.(2) The FFF beams had a smaller variation in dose rate of OAR with the depth than the flattened beams.(3) The FFF beams had smaller variations in field size and penumbral width than the flattened beams.Moreover,the penumbral width of the FFF beams increased with the increasing field size or depth.The FFF beams had a lower dose out of the fields than the flattened beams.(4) The FFF beams had smaller variations in Sc and Sc,p with the field size and depth than the flattened beams.Conclusions Removal of the flattening filter can substantially improve the dose rate,shorten radiotherapy time,and reduce leakage and scattering of the head.The dosimetric advantages make the FFF beams appropriate for clinical treatment.