Objective To develop a new scalpel which can be used in flap dissection at breast surgery and to investigate the method by which clinicians could improve the research and development of the new surgical instruments. Methods SolidWorks software was used to turn the design ideas into 3D format on personal computer, and the engineering drawing was applied for patent before being submitted to manufacturers. Results Engineering drawing met the requirements of patent application and production, and then the model smoothly entered into animal experiments. Conclusion Clinicians should study and utilize some kinds of computer aided design (CAD) software so as to not only avoid lots of modifications during trial production, but also shorten the design cycle and improve production efficiency. This method may serve as a reference for other designs.

Objective To develop a biodegradable intestinal anastomose stent which have independence intellectual proper-ty rights and investigate the method by which clinicians could improve the research and development of the new surgical instruments.Methods SolidWorks software was used to turn the design ideas into 3D format on computer,and the engi-neering drawing was applied for patent before being submitted to manufacturers.Results Engineering drawing met the re-quirements of patent application and production,and then the model smoothly entered into animal experiments.Conclusion The clinicians can be studied and utilized some kinds of computer aided design(CAD) software so as to not only avoid lost of modifications during trial production,but also shorten the design cycle and improve production efficiency.

Objective To evaluate the interstital MR lymphography using positive lymphotropic contrast agent for differentiation of metastatic lymph nodes from inflammatory lymph nodes hyperplasm.Methods Eighteen New Zealand white rabbits weighted at 2.0-2.5 kg were used.Inflammatory hyperplastic popliteal lymph node model was established in 9 rabbits by injection of complete freund adjuvant into the interdigitial skin of the dorsal aspect of one hind leg,and tumor-bearing popliteal lymph node model was established in another 9 rabbits by injection of VX~2 tumor cell suspension.The popliteal lymph nodes of another hind leg of all 18 rabbits were assigned to the normal contral group.In each group,every rabbit underwent MR lymphography examination before and after the inoculation.Volumes of 0.2 ml of Gd[DTPA-bis(2-aminoethoxy)ethane]polymeric contrast agent(Gd-poly-DTPA-EOEA)injection were injected subcutaneously into the dorsal feet of both hind legs of two groups of rabbits.T_1-weighted 3D gradient-echo images were obtained,and source images were used to reconstruct images of MIP before and after the administration of agent.The maximum short-axis diameter(MSAD)of each popliteal lymph node was measured on the enhanced 3D MIP images,and the signal-to-noise ratio(SNR)measurement was performed in the largest popliteal node of each rabbit at each time point in delayed scan.Independentsamples t test was used to compare the sizes of popliteal nodes in MSADs between inflammatorily hyperplastic and tumor-bearing nodes after the inoculation,and the values of SNRs of popliteal nodes at each time point between inflammatorily hyperplastic,tumor-bearing and normal popliteal lymph nodes.Imaging results of the popliteal nodes were analyzed and correlated with pathological findings.Results All of the rabbits were successfully inoculated except of the 2 rabbits in tumor-bearing nodal group.The size in MSAD of 13 inflammatorily hyperplastic and 11 tumor-bearing nodes was(1.32±0.14)and(1.33±0.12)cm,respectively.There was no significant statistical difference between the sizes of the two groups(t=0.186,P＞0.05).At the time of 5,15,30,60,90,120 minutes after the injection of the agent,the value of SNR of 9 inflammatorily hyperplastic and 9 contralateral normal nodes was 17.31±0.37 and 17.19±0.29,27.42±0.50 and 27.39±0.48,38.44±0.47 and 38.19±0.27,37.10±0.09 and 36.97±0.10,36.32±0.61 and 36.20±0.80,34.60±0.44 and 34.71±0.32,respectively.There was no significant statistical difference between the values of the two groups(t=0.78,0.14,1.43,1.00,0.36,-0.62,respectively,P＞0.05).The value of SNR of seven tumor-bearing and seven contralateral normal nodes was 6.00±0.22 and 17.21±0.28,7.87±0.16 and 27.17±0.23,8.14±0.24 and 38.16±0.19,8.09±0.28 and 36.94±0.30,7.59±0.20 and 35.96±0.72,7.50±0.14 and 34.81±0.27,respectively.There was significant statistical difference between the values of the two groups(t=-84.00,-182.72,-261.27,-186.48,-100.22,-239.00,respectively,P＜0.01).At each time point,inflammatorily hyperplastic nodes had significantly higher values of SNRs compared to tumor-bearing nodes(t=83.97,174.07,158.49,152.71,96.06,154.57,respectively,P＜0.01).A complete or part signal filling defect occurred in the tumor-bearing lymph node on the MR lymphographic images.Conclusions The internal anatomy and function of the lymph nodes were effectively visualized by interstitial MR lymphography with positive lymphotropic contrast agent,which provide a sensitively diagnostic way for the differentiation of benign lymph nodes from malignant ones.

Objective To evaluate in vivo tracking of swine mesenchymal stem cells (MSCs) la-beled with super paramagnetic iron oxide (SPIO) in intraportal transplantation by a clinical 1.5T MR.Methods MSCs were isolated from swine and cultured as well as expanded, which were then incuba-ted with SPIO (Feridex I. V.). Prussian blue staining was performed for showing intracelluar irons.To establish a swine model of acute liver necrosis, 0.5 g/kg of D-galactosamine was administrated to 10 pigs. MSCs(labeled cells in six, unlabeled cells in four)were injected into liver via portal veins. MR imaging was performed with a clinical 1.5T MR immediately before and at 6 h, 3 d, 7 d, 14 d after transplantation, respectively. Results Prussian blue staining of SPIO labeled MSCs could be effec-tively labeled and the labeling efficiency was almost 100%. Signal intensity loss in liver by SPIO labe-ling on FFE sequence persisted until 14 days after transplantation. Histological analysis by Prussian blue staining showed homing of labeled MSCs in liver after 14 days, primarily distributing in hepatic sinusoids and liver parenchyma. Conclusion MSCs can be labeled with SPIO in vitro successfully.MRI can monitor magnetically labeled MSCs transplanted into liver.

OBJECTIVE To study the HBV-DNA level and its replication with only HBsAb positive for transplantation. METHODS Serial serum samples were studied with the quantitative determination of HBV-DNA by a quantitative PCR assay and determination of HBsAb by ELISA. RESULTS The positive rate of HBV-DNA was 8.4% in the patients with only HBsAb positive and that was 11.11% in the patients who had not been injected with vaccine;the level of HBV-DNA in 11 samples was less than 10~4 copies/ml and five samples showed the amount between 10~4-10~6 copies/ml.The positive rate of HBV-DNA was 8.4% in the patients with only HBsAb positive and that was 11.11% in the patients who had not been injected with vaccine;the level of HBV-DNA in 11 samples was less than 10~4 copies/ml and five samples showed the level between 10~4-10~6 copies/ml. CONCLUSIONS Patients with only HBsAb positive are still infective,which should be paid attention in transplantation.

Objective: To discuss the application of BALANCE-FFE sequence in abdominal MRCP.Methods:100 patients of abdominal diseases were examined by BALANCE technique. Results: The signal of BALANCE-FFE sequence was high in abdominal MRCP examination, and BALANCE image of the coronal scan was excellent. Conclusion:The biliary tract had obviously high signal intensity acquired by BALANCE sequence. The gallstone and the stenosis could be seen. The tissue out of the bile duct, the head of pancrease and the lymph could also be seen. The BALANCE sequence could be used as a supplement of conventional MRCP.

Objective To evaluate the feasibility, methods and effectiveness of using a mechani-cal stapler for choledochojejunostomy.Methods The authors have operated on 118 patients in the management of carcinoma of head of pancreas, or periampullary tumor, or cholelithiasis.In the opera-tion, the bilio-enteric end-to-side, or end-to-end and side-to-side anastomosis was made by a circular stapler device, and then a Roux-en-Y or Brown's loop was formed for the preeedure.Results All the surgery of using stapler was done successfully.No postoperative complications such as stomal leak, bleeding and narrow were found.Meanwhile, no harmful consequences were observed through long-time follow-up.Conclusion Using mechanical stapler for bilio-intestinal anastomosis is time-saving, simple and reliable.It can be a choice for some diseases.

Objective To explore the feasibility of echo planar imaging with short time inversion recovery(STIR-EPI)diffusion weighted imaging with background signal(DWIBS)suppression in breast cancer.Methods The diffusion weighted imaging(DWI)with background suppression(b=800 mm2/s)was performed in 26 patients with breast cancer.Apparent diffusion coefficient(ADC)of all lesions,vere measured and compared.3D maximum intensity projection(3D-MIP)and reverse black and white technique were used to show the lesions.DWI and DWIBS were performed and compared for the detection of breast cancer. Randomized blocks analysis of variance was used for the ADC values in different breast tissues.the ADC values in breast cancer and benign lesion were compared using t test.The paired chi square tes:was used for the detection rate of breast cancer in two different imaging methods.Results Most of the breast cancers were hyperintense on DWI(b:800 mm2/s).,rhe ADC value of caneer tissue was(0.93±0.25)×10-3mm2/s,tumor necrosis was(2.06±0.17)×10-3 mm2/s,normal breast tissue was (1.92±0.23)×10-3 mm2/s and metastatic lymph node was(1.10±0.14)× 10-3mm2/s and the differenees were statistically significant between two structures(P＜0.01).The signal of the tissue8 around the breast cancer was decreased on DWIBS with 3 D-MIP and reverse black and white technique and similar to positron emission tomography(PET).DWIBS sequence detected more breast cancers(92.3/)and metastatic lymph nodes(88.4/)than DWI sequence did(57.6/and 42.3/,respectively,X2:8.307,P＜0.05;X2=12.235,P＜0.05).The ADC values in breast cancer(1.09±0.17)×10-3mm2/s and benign lesion (2.15±0.53)×10-3 mm2/s had significant statistical differences(t=8.626,P＜0.05).conclusion Diffusion weighted MRI with background suppression can detect more lesions than DWI and can be potentially applied for the detection of the breast cancer eombining the ADC value.

Objective To design a temperature control strategy for wave bioreactors.Methods According to the requirements of temperature control precision and response speed of wave bioreactors,the traditional PID control method was combined with fuzzy control method which was used to adjust the parameters of the PID control in real time online in order to strengthen the ability of the temperature control strategy to regulate temperature.Results A fuzzy PID controller was completed and simulation results were compared with the traditional PID controller.Conclusion The fuzzy PID control method has a smaller overshoot and shorter stability than the traditional one, so it has a higher temperature control performance.

Objective To design a temperature control strategy for riptide bioreactor to eliminate integral saturation by conventional proportion integration differentiation (PID) control.Methods According to the requirement of the riptide bioreactor for the temperature control,the temperature control system model determined by experiment was got,then the effectiveness of the integral limiter PID control method was verified,and finally the integral limiter PID control method wasimproved further using the integral separation combined with the actual experimental results and its effectiveness was tested.Results The simulation results showed that the control effects of the integral limiter PID was good.However,the actual tests proved that there was still deficiencies in large overshoot and long stable time,and good experimental results were obtainedafter improving the integral limiter PID by the integral separation method.Conclusion The improved integral limiter PID control method effectively avoids the overshoot of the system caused by the integral saturation,achieves high control precision,has a very good control performance for the temperature control of riptide bioreactor,and well meets the requirements of mammalian cell culture.