BACKGROUND:With the development of medical instruments, more and more traditional surgical operations are replaced by minimal y invasive surgeries. In minimal y invasive surgery, cutting and sealing tissue is a conventional procedure;however, due to the limitation of space and vision, the ordinary methods are not suitable for minimal y invasive surgery. OBJECTIVE:To develop high frequency electrosurgical generator that has a constant power output and ability for tissue cutting and closing. METHODS:In order to improve the efficiency of tissue cutting and sealing in surgical, a kind of high-frequency energy generator was developed for tissue cutting and sealing. The instrument consisted of switching power supply with adjustable amplitude, high-frequency power amplifier, impedance monitor and microcontrol er. The energy converter composed of switching power supply and high-frequency power amplifier converted the 220 V, 50 Hz utility powers to a kind of high-frequency energy with 450 kHz and applied on tissues. Impedance monitor would real-timely detect the electrical parameter impacting on tissue that was provide the amount of feedback to microcontrol er in order to complete constant power control and bioimpedance determination by the control er. RESULTS AND CONCLUSION:The experimental results indicated that the instrument could rapidly and stably provide high-frequency energy, and could detect the biological impedance in real-time, achieve constant power output through feedback control, and could cut and close the biological tissue efficiently.

A baseline survey on health knowledge was conducted in Yayuncun (Asian Games Village) Community in 2004 and 2005 respectively. A sample consisting of 1765 residents aged 15 and above from 600 households, who had lived in the community at least 5 years, was randomly taken; the "Beijing Typical Community Resident Questionnaire" was used for survey and the participants were followedup annually from 2006 to 2008. The results showed that the awareness rate of food nutrition and disease prevention increased year by year; however, the participants with educational level lower than junior middle school had the lowest rate of overall health knowledge. The main channels for local residents to acquire health knowledge were activities, lectures and other programs with the title of the Olympic Games; the educational level and the year of survey were independent affecting factors on overall health knowledge among residents.

Objective To evaluate the changes of physical activity status of residents in Beijing Yayuncun(Asian Games Village)Community.Methods A total of 1765 permanent residents over 15 from 600 families living in Yayuncun Communities since 2000 were selected in this prospective study.Thebaseline survey was carried out with the Questionnaire for Residents of Beijing Typical Community in 2004 and 2005.From 2006 to 2008,same questionnaire was used for the follow-up survey,and 1412 residents were responded to the questionnaire.Results The knowledge levels related to physical exercise of Yayuncun residents elevated(P＜0.01).The source of knowledge gain from Olympics Games promotion,specialized community lectures and intemet increase significantly(P＜0.01),that from other media decreased(P＜0.01).The exercise rate in community was higher than in other sites(P＜0.01)and increased significantly (P＜0.05);while doing exercise in charged sites decreased(P＜0.05).Logistic regression analysis showed that regular physical exercise was related to age,BMI,exercise-related knowledge,exercise sites,attitude for sport facilities and chronological order.Conclusion During the preparation for the Beijing Olympic Games.the status of physical exercise of residents in Yayuncun Community presented the positive trends.

Objective To quantitatively study the distance between the left atrial posterior wall and the descending aorta(DLD)in the normal fetal four-chamber view using fetal echocardiography.Methods The distances between the left atrial posterior wall and the descending aorta in end-systole (DLDs) and in end-diastole(DLDd) were measured in a standard apical four-chamber view using fetal echocardiography in 300 normal fetuses.The gestation ages ranged from 20 to 40 weeks.Fetal non-cardiac biometric parameters included femoral length(FL),biparietal diameter(BPD) and gestation age (GA) based on menstrual age. The correlation between DLDs,DLDd and non-cardiac biometric parameters were analyzed.Results In normal fetuses,the DLDs was (0.32±0.08)cm with a range of 0.19 -0.48 cm,the DLDd was (0.43 ± 0.10)cm with a range of 0.25-0.62 cm.The DLDs and DLDd increased with the growth of GA,and were correlated with GA and BPD and FL significantly (r = 0.545,0.556,0.574,0.530,0.563 and 0.576, respectively,all P <0.001).The linear regression equations between DLDs,DLDd and GA,BPD,FL were:Y =0.009GA+0.041 ,Y =0.038BPD+0.028,Y =0.044 FL+0.073,Y =0.01 1 GA+0.083,Y =0.048 BPD+0.063,Y = 0.054 FL + 0.124,respectively.Conclusions In normal fetuses,the DLDs and DLDd increase with the growth of GA,and have good correlation with GA,BPD,and FL respectively.Normal reference ranges of DLDs and DLDd have been provided.These normative data may be a new tool for assessment of fetal heart,especially has potential applications in screening of total anomalous pulmonary venous connection(TPVAC),absent pulmonary valve syndrome(APVS)or other complex congenital heart defects.

Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) in diagnosing ischemic-type biliary lesion (ITBL) and analyze the relation between the enhancement patterns of bile duct wall of ITBL and its outcome.Methods 36 patients confirmed with ITBL (24 cases),anastomotic biliary stricture (3 cases),cholangitis (4 cases),biliarysludge (1 cases),and acute rejection (4 cases),who underwent CEUS examination,were enrolled in this study.The images were retrospectively analyzed in consensus by 2 readers.After reviewing the images,the readers were asked to make a diagnosis of ITBL.The diagnostic standard was hypo-or non-enhancement of hilar bile duct wall in arterial phase on CEUS.Results The diagnostic sensitivity,specificity,accuracy,positive predictive value and negative predictive value were 66.7％,83.3％,72.2％,88.9％,and 55.6％ for reader 1;62.5％,83.3％,69.4％,88.2％,and 52.6 ％ for reader 2,respectively.The interobserver agreement was good (κ =0.83).In 24 ITBL patients,the ratio of mortality or retransplantation with non enhancing hilar bile duct wall in arterial phase was much higher than that with enhancing hilar bile duct wall (non-enhancement 54.5％,hypo-enhancement 20％,hyper-or iso-enhancement 12.5％).Conclusions CEUS had diagnostic value of ITBL.Non-enhancing hilar bile duct wall in arterial phase on CEUS predicated the poor outcome.

With the development of business of manned spaceflight, the body damage of astronauts on the space en-vironment has received growing concern. Weight loss is the most important cause of various diseases, and the weightlessness muscle atrophy is one of urgent problems to be solved in aerospace medicine. Although there is no concept of weightlessness or weightlessness muscle atrophy in the theory of traditional Chinese medicine (TCM), TCM can grasp the pathogenesis of complex diseases, and provide important theoretical references for the prevention and management of weightlessness diseases, especially weightlessness muscle atrophy. In this paper, TCM Cognition of weightlessness and the pathogenesis of weightlessness muscle atrophy was studied by the sight of TCM theory of qi hoisting. The discussion was made from aspects of circulation of qi and blood, zang-fu function. This work is wished to be beneficial to apply the TCM theory in aerospace medicine.

Objective To establish normal reference ranges of Z-score of coronary sinus CS diameter in normal fetuses and to explore the diagnostic value of CS Z-score in fetuses with persistent left superior vena cava PLSVC Methods A retrospective cross-sectional study of 227 singleton normal fetuses and 30 fetuses with PLSVC were involved Non-cardiac biometrical parameters included biparietal diameter BPD femoral length FL heart area HA and an assessment of gestation age GA based on menstrual age GA Systolic diameter of CS CSDs and diastolic diameter of CS CSDd were measured at the end of systole and diastole CSDs and CSDd Z-score models were constructed by linear regression analysis with GA FL HA and BPD as independent variables Subsequently Z-scores between normal fetuses and fetuses with PLSVC were compared Results Correlations between fetal CSDs and CSDd and four independent variables BPD FL HA and GA were excellent GA had close correlation with CSDs and CSDd CSDd Z-score= the actual measurement of CSDd- prediction of CSDd based on GA BPD FL or HA SD forecast CSDd CSDs Z-score= actual measurement CSDs-prediction CSDs based on GA BPD FL or HA SD forecast CSDs Normal reference value of CSDd and CSDs in 227 normal fetuses could be predicted as followings with GA as independent variable CSDd and CSDs were 0 139 ~ 0 3 19 cm and 0 046~0 166 cm respectively For BPD CSDd and CSDs were 0 128 ~0 303 cm and 0 040~0 1 59 cm respectively For FL CSDd and CSDs were 0 135~0 307 cm and 0 046~0 164 cm respectively For HA CSDd 0 1 57~ 0 323 cm and CSDs 0 059 ~ 0 1 75 cm respectively With GA as independent variable CSDd Z-score and CSDs Z-score were -0 906~1 256 and -0 920~0 895 respectively For BPD CSDd Z-score and CSDs Z-score were -1 168~1 196 and -0 864~0 899 respectively For FL CSDd Z-score and CSDs Z-score were -1 478~ 1 546 and -1 297~ 1 3 10 respectively For HA CSDd Z-score and CSDs Z-score were -0 832 ~ 0 610 and -0 619 ~ 0 688 respectively CSD Z-scores of 30 PLSVC fetuses as followings with GA as independent variable CSDd Z-score and CSDs Z-score were 5 263 ~ 1 1 659 and 2 846~9 923 respectively For BPD CSDd Z-score and CSDs Z-score were 4 469 ~ 1 1 000 and 2 3 10 ~9 1 14 respectively For FL CSDd Z-score and CSDs Z-score were 5 473 ~ 13 056 and 3 234 ~ 13 135 respectively For HA CSDd Z-score and CSDs Z-score were 1 922~5 701 and 1 359~5 723 respectively Z-scores of PLSVC fetuses were far away from the normals Conclusions Development of normal fetal CSDs and CSDd Z-score reference ranges is realized The CSDs and CSDd Z-scores can provide quantitative evidence in prenatal diagnosis of PLSV.

Objective To observe the effects of different interventions on the body mass index (BMI) and body fat content in overweight and obese adolescents, with an attempt to design reasonable weight relief program.Methods Totally 67 overweight or obese adolescents from a middle school of Beijing were randomly divided into three groups: control group ( n = 16 ), diet intervention group ( n= 22), and combined interventions group ( n =29). The changes of BMI and body fat rate (BFR) were observed. Results BMI significantly decreased after interventions ( diet intervention group: P = 0. 000; combined interventions group: P = 0. 018 ); the change of BMI in diet intervention group was significantly larger than that in control group ( P = 0. 035 ). The trunk and body BFRs also significantly decreased after interventions (diet intervention group: P=0. 000, P = 0. 013; combined interventions group: P = 0. 000, P = 0. 000 ); the changes of trunk and body BFRs were significantly larger in combined interventions group than those in control group ( P = 0.005, P = 0. 003 ). Conclusion Diet intervention and combined interventions are both effective in achieving weight loss in adolescents, and combined interventions have superior effectiveness.

Objective To explore the effects of diet and/or exercise intervention on oxidative stress of overweight or obese adolescents.Methods Thirty-one adolescents with normal body weight(normal control group)and 93 overweight or obese adolescents(average age(13.6 ±0.7)years; body mass index (BMI)22.4 to 34.1 kg/m2)were enrolled in this study.The overweight or obese participants were then randomly assigned to the diet group(group A),exercise group(group B),diet plus exercise group(group C),and non-intervention group(group D).Individualized caloric intake was carried out.One-hour afterschool exercise was performed once per day,4 days per week for 10 weeks.Changes of anthropometry,body composition,and metabolic biomarkers were determined.Results Compared to the normal control group,serum levels of fasting glucose,total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and malondialdehyde(M DA)of the in overweight group were significant increased(all P ＜ 0.05),although the level of SOD was significant decreased(P ＜ 0.05).Serum MDA level was positively correlated with bodyweight,BMI,TC,and LDL-C(R values were 0.209,0.228,0.274,and 0.263,respectively ; all P ＜0.05),and serum SOD level was negatively correlated with bodyweight and BMI(R values were-0.334 and-0.362,respectively ; both P ＜ 0.05).Group A,B and C showed a significant decrease in BMI,waist circumference and body fat after the intervention(all P ＜ 0.05).The level of MDA was significantly decreased after the intervention in group A and B(both P ＜ 0.05); the levels of TC and LDL-C were significantly decreased in group B and C(both P ＜ 0.05).Conclusion:Oxidative stress could have existed in overweight adolescents even when their serum glucose and lipid profiles are at a normal level.Ten-week diet and/or exercise intervention may contribute to improved body weight control,lipid metabolism,and oxidative stress response in this population.

BACKGROUND:The experimental animal models can be used to in-depth investigate the effect of ultrasound and contrast-enhanced ultrasound in the diagnosis and treatment of ischemic biliary lesions. But there is no report on the phase timing standard of rabbit model contrast-enhanced ultrasound that used in various hepatobiliary diseases. OBJECTIVE:To investigate the ultrasonic appearance of normal rabbit biliary ducts with conventional ultrasonography and contrast-enhanced ultrasonography, and the criterion of contrast-enhanced ultrasonography phase timing of rabbit liver. METHODS:The conventional ultrasonography of hepatobiliary system was performed on 10 healthy New Zealand rabbits, and contrast-enhanced ultrasonography was performed on duct wal s that displayed in conventional ultrasonography, then the features were analyzed. RESULTS AND CONCLUSION:(1) The bile duct of normal New Zealand rabbits showed a portal to biliary caliber ratio of 3.59±0.54. (2) The detection rates of common and middle lobe bile ducts were significantly higher than that of lateral lobe bile ducts on both conventional ultrasonography and contrast-enhanced ultrasonography. (3) The phases of contrast-enhanced ultrasonography of normal rabbit liver were divided into arterial phase (10-20 seconds), portal phase (21-30 seconds) and late phase (31-180 seconds). The normal duct wal presented hyper-enhancing at arterial phase and persistent iso-enhancing at portal and late phases. The establishment of these parameters of normal New Zealand rabbits not only lays a foundation for the application of contrast-enhanced ultrasonography on biliary ischemia but also expands to other hepatobiliary models.