Numerical simulation is one of the most significant methods to predict the temperature distribution in high-intensity focused ultrasound (HIFU) therapy. In this study, the adopted numerical simulation was used based on a transcranial ultrasound therapy model taking a human skull as a reference. The approximation of the Westervelt formula and the Pennes bio-heat conduction equation were applied to the simulation of the transcranial temperature distribution. According to the temperature distribution and the Time Reversal theory, the position of the treatable focal region was corrected and the hot spot existing in the skull was eliminated. Furthermore, the influence of the exposure time, input power and the distance between transducer and skull on the temperature distribution was analyzed. The results showed that the position of the focal region could be corrected and the hot spot was eliminated using the Time Reversal theory without affecting the focus. The focal region above 60 degrees C could be formed at the superficial tis sue located from the skull of 20 mm using the hot spot elimination method and the volume of the focal region increases with the exposure time and the input power in a nonlinear form. When the same volume of the focal region was obtained, the more power was inputted, the less the exposure time was needed. Moreover, the volume of the focal region was influenced by the distance between the transducer and the skull.
Computer Simulation ; High-Intensity Focused Ultrasound Ablation ; Hot Temperature ; Humans ; Neoplasms ; therapy ; Skull

Objective To investigate the teaching effect of‘index’teaching method used in practical teaching of the medical imaging.Methods A total of 178 medical undergraduates were selected this study,113 clinical medical students using‘index’teaching method were taken as experimental group while others 65 anesthesia medical students using traditional teaching method as control group.The teaching effect of‘index’teaching method was evaluated quantitatively and qualitatively by practical test and questionnaire survey.Results The test scors of experimental group were(80.3±16.5),obviously higher than those of(71.3±25.8)in control group(P＜0.05),especially instudents with low scores.Conclusion The new teaching method had obvious advantages in culturing the thinking of imaging diagnosis and in improving the ability to solve clinical practical problems,the‘index’teaching method was more effective than traditional teaching method.

Experience-oriented teaching approach was introduced into the bilingual course of medical imaging in order to improve the teaching effect.This approach was performed through English literature translation activities and scene-teaching.Meanwhile it points out that this approach has particular advantages in stimulating students' interest and initiative in study.

ObjectiveTo evaluate the clinical efficacy and safety of nylon ligation combined with endoscopic high-frequency electric snare for the treatment of colorectal polyps.MethodsThe clinical data of 345 patients with colorectal polyps who received the treatment of nylon ligation combined with endoscopic high-frequency electric snare at the Zhongshan Hospital of Fudan University from January 2006 to January 2011 were retrospectively analyzed.Complications including bleeding and perforation were observed.Postoperative wound healing and local residual recurrence were assessed during follow-up.ResultsA total of 362 colorectal polyps were successfully removed.The mean diameter of the colorectal polyps was 2.7 cm (range,1.5-4.0 cm). Operative bleeding occurred in 1 patient,and perforation in 1 patient.The results of histological examination showed that 93.6％(339/362) colorectal polyps were adenoma,17 were hyperplastic polyps,5 were inflammatory polyps,and caneeration of colorectal polyps in 1 patient was detected.Endoscopic follow-up was completed in 334 patients at the first month after operation,and 9 patients with residual benign colorectal polyps received endoscopic resection.No residue or recurrence was found in the other patients.Endoscopic follow-up was completed in 308 patients at the second months after operation,and no residue or recurrence was found.The overall effective rate was 97.1％ (299/308).ConclusionEndoscopic nylon ligation combined with endoscopic high-frequency electric snare is effective and safe for the treatment of colorectal polyps.

Objective To evaluate the clinical efficacy and safety of metallic hemoclips in the treatment of gastric defects during endoscopic full-thickness resection. Methods Patients with submucosal tumors derived from the muscularis propria and adhesion of the gastric serosa diagnosed by EUS and CT were enrolled in the study.A total of 62 patients,22 males and 40 females,mean age 58.5 years,were recruited into the present study from June 2009 to December 2010,in which 37 patients were with tumors in gastric fundus,20 in gastric body and 5 in antrum.All patients were treated with endoscopic full-thickness resection.After the operation,metallic hemoclips were used to close the defects through endoscopic biopsy channel.The closure success rate with metallic hemoclips were assessed.The patients were followed up endoscopically for evaluation of efficacy and safety of the procedures.Results All patients underwent endoscopic full-thickness resection.Uncontrollable bleeding occurred in 1 patient,who subsequently underwent emergent laparoscopic surgery and was excluded from the study.Metallic hemoclips were applied to close defects in 57 patients,and metallic hemoclips combined with omentum obstruction in 4 patients.The overall success rate was 100％ in 61 patients.Endoscopic follow-up was completed in all patients in average of 4.4 months.The clinical wound healing rate was 100％.No complications such as fever,abdominal pain were found in 2months after the procedures.Conclusion Application of metallic hemoclips during endoscopic full-thickness resection for gastric defects is a safe and effective technique.

Objective To investigate the modulation of EPCs by interleukin 1β (IL-1β) and p38 mitogen activated protein kinase (p38MAPK) and the pathogenesis resulting from their dysdifferenfiation after trauma.Method Thirty pigs were divided into a control group (n = 15) and a multiple organ dysfimction syndrome (MODS) group (n = 15), the latter of which were subjected to a "two-hit" injury including hemon'hagic shock and endotoxemia. Phosphorylation of p38MAPK in peripheral blood mononuclear cells was monitored by western blotting. The concentration of IL-1β in peripheral blood plasma was determined by ELISA and the numbers of EPCs with FCM in peripheral blood plasma were monitored. The morbidity rates in the two groups were compared by chi square test. The levels of phosphorylation of p38MAPK in peripheral blood mononuclear cells, the concentmtions of IL-1β in peripheral blood plasma and the numbers of EPCs in the peripheral blood were compared between groups using with Student's t lest. Results The level of p38MAPK phosphorylation was more augmented and the concen-tration of IL-1β higher in peripheral blood mononuelear cells and plasma from MODS pigs compared with those from control pigs; nevertheless the mauler of EPC conspicuously decreased in the peripheral blood (P <0.01). The morbidity rate in the MODS group was much higher than that in the control group (P < 0.01). There were fewer EPCs in the peripheral blood of animals in group M than in the peripheral blood of animals in group C (P <0.01). Conclusions p38MAPK phosphorylation is important for the pathogenesis of MODS. p38MAPK phospho-rylation might cause the concentration of IL-1β in the peripheral blood plasma to rise and could cause a drop in the numbers of EPCs, thereby aggravating the inflanmmatory reaction in MODS.

Objective To evaluate clinical efficacy and safety of endoscopic radial incision( ERI) for benign stricture of esophageal anastomosis. Methods Clinical data of 17 patients with benign stricture of e?sophageal anastomosis undergoing ERI from October 2013 to September 2014 were retrospectively studied. Im?provement of clinical symptom and treatment?related complication or discomfort were intensively analysed. Re?sults All 17 patients successfully received ERI procedures, and the mean operating time was 10 minutes with a mean of 4 incisions. Obvious bleeding and mis?cut of normal mucosa occurred in 1 case, and this patient was cured by endoscopic hemostasis, gastrointestinal decompression and administration of antibiotics. Heartburn oc?curred in 5 patients and disappeared spontaneously without other complications or discomfort. Dysphagia score decreased from 3?11 to 0?90 in the second day after ERI(P<0?01).The mean follow?up time was 15?5 months ( range 9?20 months) . The dysphagia score showed no significant difference between the follow?up period and the second day after ERI ( P>0?05 ) . Conclusion ERI is simple, safe and effective for treating benign stricture of esophageal anastomosis.

Objective To explore the clinical effect of endoscopic retrograde cholangiopancreatography (ERCP) for elderly patients with periampullary diverticula accompanied with choledocholithiasis.Methods The retrospective cross-sectional study was conducted.The clinical data of 297 elderly patients with age ＞70 years and periampullary diverticula accompanied with choledocholithiasis who were admitted to the Zhongshan Hospital affiliated to Fudan University between January 2013 and January 2016 were collected.All the patients received lithotomy by ERCP after completion of preoperative preparation,and then underwent symptomatic treatment.Observation indicators included:(1) treatment results:cannulation time,success rate of cannulation and success rate of stones removed;(2) surgical complications:hemorrhage,perforation and pancreatitis;(3) follow-up results.All patients were followed up by outpatient examination and telephone interview up to December 2016.Follow-up included postoperative delayed perforation,patients' survival,further attack of acute cholangitis and reoperation for removing stones.Measurement data with normal distribution were represented as x ± s,and measurement data with skewed distribution were described as M (range).Results (1) Treatment results:all the 297 patients underwent successful lithotomy by ERCP,with a cannulation time of (5±4)minutes and a success rate of cannulation of 100.00％ (297/297).Of 297 patients,292 had one-off success of stones removed,with a one-off success rate of 98.32％ (292/297),and 5 received partial stones removed due to choledocholithiasis combined with acute cholangitis.(2) Surgical complications:4 patients were complicated with immediate hemorrhage during intraoperative endoscopic sphincterotomy (EST).Bleeding of 1 patient was cauterized by biopsy forceps,and 3 patients had simplex JHY-BAL compression hemostasis.Two patients with postoperative delayed hemorrhage had successful hemostasis by biopsy forceps with metal hemostatic clip under endoscope after emergency duodenoscopy.One patient with intraoperative perforation was cured by conservative treatment.Two patients with severe acute pancreatitis underwent continuous gastrointestinal decompression combined with maintenance therapy of somatostatin,and then received endoscopic ultrasound-guided puncture and drainage for pseudocyst around the pancreas,with a stable symptoms of pancreatitis after 4 weeks.(3) Follow-up results:all the 297 patients were followed up for 6-12 months,with a median time of 8 months.During follow-up,292 patients had healthy survival,without recurrences of cholangitis and bile duct stone,and no delayed perforation and death were detected.Five patients underwent the second time lithotomy by ERCP after 2-3 months postoperatively.Conclusion Lithotomy by ERCP is safe and effective in the treatment of elderly patients with periampullary diverticula accompanied with choledocholithiasis.

BACKGROUND:The number of elderly patients with hip fracture is huge, and this population mainly combines with a variety of internal diseases. The general condition was bad. Compared to total hip arthroplasty, bipolar hemiarthroplasty can shorten operation time, reduce the time of anesthesia and improve surgical safety, but the operation using which fixation mode is always controversial.
OBJECTIVE:To compare the safety and curative effects of bipolar hemiarthroplasty with cementless or cement femoral stem prosthesis in elderly patients with osteoporotic complex hip fracture.
METHODS:From June 2007 to June 2010, 198 elderly patients with osteoporotic hip fracture aged more than 75 years old, who were treated with bipolar hemiarthroplasty in the People’s Hospital of Xinjiang Uygur Autonomous Region, China, were enroled in this study. Al patients were divided into cementless group (n=69) and cement group (n=129) according to the type of prognosis. Osteoporosis was treated conventionaly in both groups after replacement. Operation time, intraoperative blood loss, incidence of postoperative hip pain, out of bed activity time post surgery, Harris scores of last folow-up and loosening rate of the prognosis were compared between the two groups.
RESULTS AND CONCLUSION:176 of above 198 cases were folowed up for 48 to 84 months, including 122 in the cement group and 54 in the cementless group. Operation time was longer in the cement group than in the cementless group, but out of bed time was earlier in the cement group than in the cementless group post surgery, and there were significant differences (P < 0.05). The incidences of loosening and hip pain were more in the cement group than in the cementless group post surgery (P < 0.05). No significant difference in intraoperative blood loss and Harris scores of last folow-up was detected between the two groups (P > 0.05). The incidences of loosening rate were 5% and 4% in the cement and cementless groups, respectively, which showed significant differences (P< 0.05). These results indicate that bipolar hemiarthroplasty with or without cement for osteoporotic hip fracture in the elderly can obtain good middle- and long-term effects. Bipolar hemiarthroplasty with cement can reduce the out of bed time, but operation time was longer, and incidences of hip pain and loosening were higher in cement prosthesis than in cementless prosthesis.

OBJECTIVE To evaluate the value of central compartment neck dissection for cN0 papillary thyroid carcinoma.METHODS The clinical data of 46 cases with cN0 papillary thyroid carcinoma in our hospital from Jan.1999 to June 2004 were retrospectively studied.The level Ⅵ lymph nodes were removed during the operation.RESULTS In 46 cN0 cases,there were 11 cases(23.9 %) pathologically proved lymph nodes metastasis after operation.Four patients developed neck recurrence and underwent neck dissection.CONCLUSION It is necessary to probe the level Ⅵ lymph nodes during the operation for cN0 papillary thyroid carcinoma patients.