Objective The electrophysiological parameters of atrioventricular conduction function in patients with atrioventricular nodal reentry tachycardia (AVNRT)were analyzed,and to explore the effect of different ablation endpoints on atrioventricular conduction function in patients with AVNRT.Methods 96 cases with AVNRT under-went radiofrequency catheter ablation (RFCA)of slow conduction pathway.According to whether the slow pathway eliminated,the patients were divided into the slow pathway disappeared group and slow tracks remaining group.Preop-erative and postoperative intracavitary electrophysiological examination and atrioventricular function data were recor-ded,including before and after radiofrequency ablation of bundle of HIS,PA,AH,HV interval,atrioventricular prequel venturi point(AVN -WKB),ventriculoatrial retrograde venturi point(VAN -WKB),atrioventricular node prequel effective refractory period(AVB -WKB).Patients were followed up by telephone for a year.Then,a comparative anal-ysis of preoperative and postoperative was done.Results RFCA of AVNRT patients with atrioventricular node pre-quel time effect:RFCA and preoperative ratio,after his bundle electrogram PA,ah,HV interval had no significant changes(P >0.05).Effect of RFCA surgery on patients with AVNRT refractory atrioventricular node prequel:com-pared with RFCA before surgery,postoperative slow pathway disappear fast pathway shortening of effective refractory period[preoperative(287.5 ±46.2)ms,postoperative(260.2 ±55.6)ms,t =2.901,P =0.005],slow pathway effec-tive refractory period[disappear preoperative(243.3 ±43.2),postoperative(0.0 ±0.0)ms,t =43.290,P =0.000], AV node Wenckebach point in advance before operation[(261.3 ±44.3)ms,postoperative(293.2 ±46.2)ms,t =3.828,P =0.000];group after slow pathway to improve fast pathway effective refractory period without obvious change (P >0.05 ),the slow pathway effective refractory period in high concentration [preoperative (242.2 ± 42.8)ms,postoperative(281.2 ±41.3 )ms,t =3.879,P =0.000〗,atrioventricular node Wenckebach point in advance before operation[(261.5 ±43.5)ms,postoperative(291.3 ±46.5)ms,t =2.769,P =0.007〗.Comparison between groups,after slow pathway disappeared group fast pathway effective refractory period was significantly shorter in the slow diameter improvement group,but between the two groups in the atrioventricular node Wenckebach point differences was not statistically significant(P >0.05).There was no recurrence in the follow -up after a year of slow path loss and slow pathway.Conclusion RFCA caused by slow pathway to disappear or modified two slow pathway ablation right AVNRT patients atrioventricular time had no effect,but all the atrioventricular junction the prequel's point advance.The atrioventricular node slow pathway disappear fast and effective pathway refractory period short-ened,slow pathway improved the slow pathway effective refractory period.RFCA surgery done by the slow pathway dis-appeared or slow pathway ablation is effective in patients with AVNRT,and there was no significant recurrence rate in both groups within 1 year.

Objective:To establish an animal model in goats for curved mandibular regeneration by distraction osteogenesis(DO).Methods:Four goats were used.Internally installed curved mandibular distractors were activated 6 days after mandibular osteotomy on the mandibular angles or mandibular symphyses at a rate of l mm/d for 25~34 days.The mandibles were examined by roentgenography.Results:The arched defects of the mandibles in the 4 goats were reconstructed by regenerated bone by the end of DO.Conclusion:Internally installed curved distractor may be used for osteogenesis in the repaire of the arched mandibular defects.

Objective To study the clinical feature, diagnosis and surgical treatment of mixed hepatocellular and cholangiocellular carcinoma(MHC).Methods The clinical materials of 14 surgically treated patients with MHC were retrospectively analyzed.Results There were nine males and five females, with age ranging from 33 to 62 years (mean 50 years). Some patients had a history of hepatitis B(71%), and cirrhosis(64%). Elevation of serum alpha-fetaprotein(AFP) was observed in nine patients(64%). The resection rate was 86%(12/14), and postoperative overall 1-, 3-, 5-year survival rates were 71%(10/14)?43%(6/14)?and 29%(4/14), respectively. In the tumor-resected patients, the 1-, 3-, 5-year survival rates were 83%(10/12)?50%(6/12)?and 33%(4/12),respectively. Conclusions MHC patients lack typical clinical manifestations. Radical surgery is an effective treatment for this disease. The cholangiocellular carcinoma component appears to determine the prognosis.

It has been 4 years since Natural Health Products Regulations(NHPRs)was enforced by Health Canada in January of 2004.In the past time,how will it affect the marketed Traditional Chinese Medicines(TCM) in Canadian market? Recently,The two TCM products Carditionic Pill (Fufang Danshen Diwan)and Chaihu Pill from Tasly have been newly certificated by Health Canada recently.Taking them as examples,this article introduces the current status.opportunities and challenges for the regulation of TCM in Canada.and suggests that the domestic TCM corporations push the product registration as soon as possible.

Objective:This paper studied the electromagnetic-driven pressure control system in the automatic measurement of intraocular pressure (IOP).The accuracy of pressure control directly impacts on the accuracy of IOP measurements,so it calls for precise pressure to achieve closed-loop control.Methods:According to the actual needs of IOP measuring,we got the structural and electromagnetic parameters of the electromagnetic drive system by combining the methods of numerical calculation and ANSYS simulation.Using the FC bus and digital-analog conversion,the microcontroller module controlled the drive current digitally and precisely in order to achieve closed-loop control of pressure.Results:The experimental results showed that in the electromagnetic pressure control system,the pressure range was 0 N～0.48982 N,the accuracy 0.00058 N,the drive current control error about 1% on average.Besides,the electromagnetic force and the excitation current showed a good linear relationship in the same stroke.Conclusions:The electromagnetic pressure control system achieved a good result in closed-loop control of pressure.The control pressure range and control accuracy were in line with the standard of Goldmann applanation tonometer.According to the results,this study laid the foundation for the further development of IOP automatically measuring instruments.

Objective To evaluate the safety of percutaneous radiofrequency ablation (RFA ) in hepatic malignant tumors under the guidance of ultrasonography .Methods The clinical data and the follow‐up radiographic images of the patients with hepatic malignant tumors treated by percutaneous RFA between January 2012 and February 2014 were retrospectively reviewed ,and the major or minor complications of RFA were both calculated .Results 1 568 lesions were ablated by 1 080 percutaneous RFA procedures in 900 patients with hepatic malignant tumors under the guidance of the sonography .The average size of the tumors was (2 6.± 1 2.)cm .The total complications rate of 1 080 RFA procedures was 5 9.3% (64/1 080) , which including intra‐abdominal bleeding 2 7.8% (30/1 080) ,hepatic abscess 0 7.4% (8/1 080) ,biliary tract damage 0 6.4% (7/1 080 ) ,vascular damage 0 5.6% (6/1 080 ) ,tract seeding 0 4.6% (5/1 080 ) ,pleural hemorrhage 0 3.7% (4/1 080) ,gastrointestinal damage 0 1.8% (2/1 080) ,hepatic encephalopathy 0 0.9% (1/1 080) ,and death 0 0.9% (1/1 080) .While major complications was 1 9.4% (21/1 080) vs minor 3 9.8% (43/1 080) .Sixty three patients with complications recovered after treatments including blood transfusion , ablation ,surgery ,interventional drainage procedure and liver transplantation ,only one patient died for irreversible liver failure .Conclusions RFA for hepatic malignant tumors under the guidance of sonography is a safe method with lower complications rate ,however ,the potential major complications and the indications of RFA liver malignant tumors should be carefully focused on .

A century ago the Flexner Report facilitated the process of modern medical education reform.Half a century ago,Problem-based learning initiated the student-centered medical education model.At present training medical students' competency will usher in the third reform in medical education.Over 100 years' development and in the global context of current medical education reform,China's medical education has become an important part of the world medical education.Harbin Medical University conducted an all-around reform through international cooperation and received the accreditation referenced according to global standards in medical education,which is an epitome of the medical education reform in China.

Objective To evaluate the diagnostic value of contrast enhanced ultrasonogrphy(CEUS) and quantitative analysis in differentiating between thyroid solid malignant masses and solid benign masses.Methods 40 patients with thyroid solid mass were enrolled into this prospective study between March 2012 and June 2012.A total of 45 thyroid solid masses were evaluated by CEUS,and the final pathology diagnosis was confirmed by core biopsy or thyroidectomy.The diagnostic yield of enhancement patterns and quantitative parameters were assessed for differentiating between the solid malignant and benign masses.Results Enhancement patterns were classified into five types (nonenhancement,early hypo enhancement,hypo enhancement,isoenhancement,hyperenhancement).Two malignant masses had nonenhancement pattern,and 6 malignant masses had early hypoenhancement pattern,and 14 malignant and 4 benign masses had the hypo enhancement pattern,and 5 malignant and 7 benign masses had the isoenhancement pattern,and 1 malignant and 6 benign masses had the hyperenhancement pattern.There was a significant difference between malignant and benign enhancement patterns of thyroid solid masses (x2 =12.184,P =0.016).Nonenhancement,early hypoenhancement and whole phase hypoenhancement pattern predict thyroid solid malignant masses with sensitivity of 78.5 ％ and specificity of 76.5 ％.Among seven quantitative parameters used to predict thyroid malignant mass,the relative maximum intensity (IMAX％) of lesions had highest value in differentiating between the malignant and benign masses with sensitivity of 80.8 ％ and specificity of 82.6％,and area under receiver operating curve (AUC) of the IMAX％ was 0.878.RT (rising time),TTP (time to peak intensity),mTT (mean transit time) had almost non differentiation value with AUC of 0.619,0.601,0.656 separately.And mTT-Ratio (mTT of lesion/mTT of parametric area),RT-Ratio (RT of lesion/RT of parametric area),TTP-Ratio (TTP of lesion/TTP of parametric area) had less differential diagnostic value with AUC of 0.749,0.744,0.704 comparing with IMAX％.Conclusions Nonenhancement and early or whole phase hypoenhancement could be characteristic enhancement pattern of malignant thyroid solid masses,and IMAX％ had good diagnostic value in differentiating between malignant and benign masses among the quantitative parameters.

Objective To evaluate the short-term efficiency and risk factors for effects after percutaneous radiofrequency ablation (RFA) for hepatic malignant tumors under the guidance of sonography.Methods The clinical data and the follow-up radiographic images of the patients with hepatic malignant tumors treated by percutaneous RFA were reviewed between June 2011 and May 2012,and the short-term incomplete ablation rate,recurrance rate and tumor progression rate were calculated,and the factors affecting the incomplete ablation rate,recurrence rate and progression rate were analyzed.Results 610 lesions were ablated in the total of 462 RFA procedures for 405 patients under the guidance of sonography with percutaneous method.The average size of the tumor was (2.5 ± 1.1)cm.During at least 3-month follow-up,complete and incomplete ablation rate was 89.2％ (544/610) and 10.8％ (66/610)separately,and recurrance rate and progression rate of tumor was 17.5％ (81/462) and 23.8％ (110/462).The numbers (≥3) and the size (≥3 cm) and the location (close to vessels) of the lesions reduced the complete ablation rate.The numbers (≥3) of lesions affected the recurrence rate and progression rate of lesions as only risk factor.Recurrent hepatocellular carcinoma (HCC) and metstasis from gastrointestine or non-gastrointestine had higher recurrence rate and progression rate comparing with primary HCC.Conclusions RFA can effectively control local progression of hepatic maglinant tumors,and the tumor's size,number and location close to velssels could effect complete ablation rate,the number of tumors could effect the recurrence and porgression rate.Recurrent HCC and metstasis from gastrointestine or nongastrointestine had higher recurrence and progression rate comparing with primary HCC.

OBJECTIVE:To optimize the parameters of the extraction and purification technologies of total flavonoids from Di-ospyros kaki Thunb. leaves,and then to compare the contents of flavonoids in fresh and dried D. kaki Thunb. leaves. METHODS:Taking the yield of total flavonoids as the investigated index,the influences of liquid-solid ratio,the volume fraction of ethanol and ultrasonic extraction time on the extraction effect were discussed by single-factor and orthogonal test. With the purity of total flavo-noids as the investigated index,the purification effects of such three kinds of methods as ethyl acetate extraction method,alcohol deposition method and macroreticular resin purification method combined with petroleum ether degreasing on the extracted solution were compared. The optimal extraction technology was adopted to extract the total flavonoids from fresh and dried D. kaki Thunb. leaves and their contents were compared. RESULTS:The optimal extraction technology was as follows as liquid-solid ratio of 25∶1 (ml/g),volume fraction of ethanol of 70%,ultrasonic extraction time of 30 min,extraction temperature of 30 ℃. The results of the verification tests showed the average content of total flavonoids was 1.75%(RSD=2.00%,n=3). The total flavonoids in the extracted solution purified by the above-mentioned three purification methods had a purity of 24.92%,15.94% and 35.52% respec-tively,in which the macroreticular resin purification method with petroleum ether degreasing combined with AB-8 resin purification was optimal. The content of flavonoids in fresh D. kaki Thunb. leaves(1.75%) was about twice as much as that in dried leaves (0.87%). CONCLUSIONS:The optimal extraction and purification technologies are simple with good effect,and suitable for large-scale production. Fresh D. kaki Thunb. leaves should be used as raw materials for extracting flavonoids.