BACKGROUND:In the clinical orthodontics, ceramic brackets have deficiencies in the aspects of antibacterial and mechanical properties, which easily lead to the emergence of a variety of adverse events and influence the orthodontic effect. OBJECTIVE:To observe the antibacterial and mechanical properties of nano silver hydroxyapatite coating ceramic brackets. METHODS:The nano silver hydroxyapatite coating ceramic brackets were prepared. Scanning electron microscopy was used to observe the coating surface. Coating antibacterial experiment was conducted. Totaly 50 in vitro human maxilary premolars were randomly divided into two groups (n=25 per group): experimental and control groups. Premolars in the experimental group were bonded to nano silver coating hydroxyapatite ceramic brackets, and premolars in the control group were bonded to ordinary ceramic brackets. The shear strength was detected in these two groups.RESULTS AND CONCLUSION: The overall structure of nano silver hydroxyapatite coating was order, uniform and compact. Hydroxyapatite had a porous structure with a micro-nanometer aperture and there were a large number of nano-silver particles uniformly distributed. Quantitative antibacterial experiments showed that nano silver hydroxyapatite coating ceramic brackets had a strong inhibition to Escherichia coli and Staphylococcus albus, with an antibacterial rate of more than 95%. The shear strength in the experimental group was lower than that of the control group (P < 0.05). These results demonstrate that the nano silver hydroxyapatite coating ceramic brackets have good antibacterial and mechanical properties, which meet the requirement of mechanical change in the clinical orthodontics.

To investigate the value of echocardiography in the diagnosis of total anomalous pulmonary venous connection (TAPVC), 16 patients in our hospital were diagnosed to have TAPVC by echocardiography from year 1994 to 2001. In 11 cases the results of echocardiography were compared to those of surgery. Each patient was examined by using a combination of precordial, suprasternal and subcostal windows to visualize all the pulmonary veins and their drainage sites, common pulmonary venous trunk, and other associated abnormalities. Of the 16 cases, the drainage sites were as follow: supracardiac in 10, via vertical vein in 9, directly to superior vena cava in 1; cardiac in 5, via coronary sinus in 2, directly to right atrium in 3. Diagnoses were correctly made in all the 11 cases as confirmed by surgery. Echocardiography can also assess pulmonary arterial pressure and detect other associated abnormalities. It is concluded that echocardiography is the preferred examination method in the diagnosis of TAPVC before surgery. With careful examination using multiple windows and sections, TAPVC can be accurately diagnosed by echocardiography.
*Echocardiography, Doppler, Color ; Heart Defects, Congenital/*ultrasonography ; Pulmonary Veins/*abnormalities ; Pulmonary Veins/ultrasonography

The TLD(thermoluminescent dosimetry)must be calibrated before used in individual dosimetry.In this paper,some related issues that affect the accuracy of calibration,including principle and performance of the instruments,conditions of annealing and measuring,method of curve fitting are discussed and an appropriate calibration method is proposed.The results show that the method we proposed is valid and efficient,which ensures the accuracy of individual dosimetry.

Operation of radiological equipment affects not only the quality of clinical diagnosis & treatment,but also the health of the radiographer and subjects.The operation and safety protection of the aged radiological equipment in primary medical units has to be paid particular attention to.Based on the survey,some advices are put forward from the aspects of equipment management,personnel training and protection supervision.

We began our teaching reform by following the step of national adjustment of majors frame at the end of last century.We perfected our teaching contingent,created advanced content, composed high quality text book,used multiple teaching methods and ways, paid attention to practical teaching,carried out effective access system and in the end,we firstly combined Meridian and Collateral and Acupuncture,which are the two major courses,into one basic course called Meridian and Acupoint.It covers different levels of students including doctors,postgraduates,undergraduates and seven-year-class students and has the features of abundant and detailed content,creative methods and excellent effects.

The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV "Full volume" images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r = 0.73; r = 0.69; r = 0.63; r = 0.66, P < O. 25-0. 0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P < 0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P < 0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P > 0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r = 0.986, P < 0.001; r = 0.93, P < 0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r = 0.83; r = 0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.
Cardiac Volume ; Echocardiography, Three-Dimensional ; Electrocardiography ; Systole ; Ventricular Function, Right/*physiology

Objective To explore the role of echocardiography in the therapeutic evaluation after surgical repair of anomalous origin of the left coronary artery from the pulmonary artery(ALCAPA). Methods Six patients with ALCAPA underwent surgery from 2000 to 2007 ,including 3 intrapulmonary tunnel procedures and 3 left coronary artery bypass graft procedures. Post-operative echocardiography was given in every case and the characteristics were compared with the pre-operative results. Results In all cases, the mainly coronary haemodynamics recovered rapidly with decreased severity of mitral regurgitation and excellent cardiac function. Five patients had smooth rebuilded vessels but 1 patient had mild anastomotic block and slight intrapulmonary tunnel leakage. Conclusions Transthoracic echocardiography can evaluate the rebuilded coronary artery, possible complication, cardiac morphous and function and the severity of mitral regurgitation accurately.

Objective To evaluate the early change of left ventricular (LV) systolic function in patients with type 2 diabetes mellitus(T2DM) by ultrasound speckle tracking imaging. Methods Ninety-five subjects were included:40 T2DM with normal LV ejection fraction (LVEF≥50% ,group A),20 T2DM with abnormal LVEF (LVEF<550 %) (group B), and 35 normal controls. Two-dimensional strain images were acquired from LV short-axis view. LV peak systolic global and segmental radial strain and circumferential strain at the levels of mitral annulus, papillary muscle and apex, and LV systolic global and segmental rotation at the levels of mitral annulus and apex and LV peak systolic global twist were assessed. Results In group A, compared with control group, LV peak systolic radial strain parameters were not significant difference (P >0.05), peak systolic circumferential strain of part segments, average peak strain of each plane and global strain were reduced (P <50.05～0.001) ,and LV peak systolic rotation of all apical segments, peak systolic global rotation at the levels of mitral annulus and apex,and peak systolic global twist were significantly increased (P <0.05～0.001). Compared with control group and group A,all LV systolic radial strain and circumferential strain parameters, LV systolic global and segmental rotation and peak systolic global twist in group B were significantly reduced (P <0.05 ～ 0.001). Conclusions Speckle tracking imaging could be used to evaluate the early change of LV torsional deformation and LV systolic function in T2DM.

Objective To explore the value of transthoracic echocardiography in diagnosis of Berry syndrome and analyze the sonographic typing.Methods The echocardiographic results of 6 Berry patients were reviewed retrospectively.Their sonographic typing were also analyzed connected with the reports in the literature.Results The ultrasound diagnosis of 5cases were confirmed by surgery(3)or angiography(3) and the remain one infant was died 14 days after the echocardiographic procedure.The malformations of Berry syndrome consisted of the distal aorto-pulmonary septal defect(APSD),aortic origin of the right pulmonary artery(RPA),interruption of the aortic arch(5 cases,type A with patent ductus arteriosus)or coarctation of the aortic isthmus(1 case)with intact ventricular septum.In 6 cases,there were 2 sonographic types:(1)Type A(3 cases),the aorto-pulmonary septum was almost absent and the left and right pulmonary arteries remained widely separated,the blood of the RPA came almost from the aorta,the aortic arch was interrupted.(2)Type B(3 cases),the left and right pulmonary arteries remained adjacent and the bifurcation straddled the distal APSD,the blood of the RPA came from the aorta and the pulmonary trunk separately,the aortic arch was coarctated or interrupted. Conclusions The transthoracic echocardiography can be used to evaluate all containing malformations of Berry syndrome and it may be the first diagnostic choice.

Objective To explore the value of transthoracic echocardiography in diagnosis of univentricle and analyze the sonogram typing. Methods The results of 66 patients with univentricle were reviewed retrospectively,and analayzed their typing connected with the reports in the literature. Results There were 3 ultrasonic types in 66 cases:①Type A(single left ventricle) 19 cases,single ventricle with left ventricular shape,residual cavity in front of it. ②Type B(single right ventricle) 38 cases, single ventricle with right ventricular form,and residual cavity in the rear.③Type C (solitary single-ventricle) 9 cases,there was only one ventricle. Thirty-one of them were treated surgically, 5 cases without operation had MRI or cardiac catheterization examination and the remaining 26 patients were only observed by echocardiography,the positive rate of diagnosis in type was 100%, the results were compared with cardiac catheterization or MRI examination and the operation: 1 cases of mixed type total anomalous pulmonary venous connection was misdiagnosed as heart-type total anomalous pulmonary venous drainage. But 1 case of descending aorta limitations narrow complicated patent ductus arteriosus(PDA), PDA was missed. The rest were completely correct diagnosis. Conclusions The transthoracic echocardiography can be used to evaluate types and all containing malformations of univentricle,and offers reliable information for operation.