Aiming at the present condition of the experiment teaching of the medical science electronics,we have reformed traditional teaching mode,built up new experiment teaching system,perfected content of course and promoted the quality and the level of the experiment teaching in medical electronics effectively.

Objective To explore the effect of coronary artery bypass grafting(CABG) on left atrial (LA) function by strain rate imaging(SRI). Methods Twenty-three patients with coronary heart disease who underwent coronary artery bypass grafting were involved. SRI was performed on those patients to evaluate LA function quantitatively at baseline (before CABG),and at 1 week, 1 month and 3 months after CABG. Peak strain rate(SR) was measured at each segment (septal, lateral, posterior, anterior, and inferior walls) and mean peak systolic SR (SRs),peak early diastolic SR (SRe) and peak atrial systolic SR (SRa) were calculated by averaging data in each segment. Results Compared with the baseline,LV pre-systolic volume(LAVp), maximal volume (LAVmax), minimal volume (LAVmin), LV active emptying fraction (LAAEF) and passive empting fraction(LAPEF) had on significant differences at 1 week (P >0.05). LAVp,LAVmin,LAVmax and LAAEF decreased gradually after CABG, LAPEF increased gradually after CABG (P <0.05). Compared with the baseline, the peaks of SR curve showed no significant differences at 1 week (P >0.05). Nevertheless,the peaks of SR were increased at systole and early diastole,decreased at atrial contraction at 1 month (P <0.05). Those changes were turned more significantly at 3 months (P 0.01). Left ventricular ejection fraction (LVEF) both increased at 1 month and 3 months,and its changing rate correlated inversely with the changing rate of SRa respectively (r = -0.751, -0.783,all P<0.01).Conclusions LA function is affected by CABG, presented as reservoir and pump functions decreased and conduit function increased. SRI can evaluate the atrial function quantitatively and monitor the changing of LA function dynamically after CABG.

ObjectiveTo evaluate left atrial function in patients with dilated cardiomyopathy (DCM)by echocardiography.MethodsThere were 31 patients with DCM and 30 controls in this study.Left atrial diameter (LAD),left ventricular diameter (LVD) were measured by M-mode in parasternal long-axis view.Mitral flow parameters including peak velocities during early diastole (E) and late diastole (A) were measured by pulsed-wave Doppler echocardiography,and the E/A ratio was calculated.Left ventricular ejection fraction (LVEF) was measured with Simpson′s method on the 2-chamber (Ap2c) and 4-chamber (Ap4c) views.Strain rate (SR) imaging was performed on all cases.Peak SR was measured at each segment (septal,lateral,posterior,anterior,and inferior walls) and mean peak systolic left atrial SR (mLASRs),mean peak early diastolic left atrial SR (mLASRe) and mean peak atrial systolic left atrial SR (mLASRa) were calculated by averaging the data in all segments.ResultsCompared with controls,LAD and LVD were significantly increased ( P ＜0.01 ),the E/A ratio had no significant changes ( P ＞0.05).LVEF and left atrial fractional shortening (LAFS) turned lower,mLASRs,mLASRe,and mLASRa of DCM decreased significantly ( P ＜ 0.05).mLASRa of DCM correlated positively with LAFS ( r =0.79,P ＜ 0.01 ).ConclusionsThe left atrial function of DCM decreased,including the reservoir,conduit and pump function.Echocardiography could evaluate the left atrial function of DCM quantitatively.

Objective To explore the value of echocardiography in detecting left atrial systolic function in patients with hypertrophic cardiomyopathy(HCM) or hypertensive left ventricular hypertrophy (HLVH). Methods There were 3 groups in this study,the group of HCM, HLVH and control,each group had 30 cases. Left atrial diameter,interventricular septal thickness, posterior left ventricular thickness, peak E and A of mitralis were measured by conventional echocardiography. Left atrial fractional shortening (LAFS) was calculated. Tissue velocity imaging of all patients and controls were accepted in apical two, four and long axis chamber views. Strain rate(SR) imaging was performed on all cases, peak atrial systolic left atrial SR(LASRa) were measured at each segment (septal,lateral, posterior,anterior, and inferior walls of left atrium), mean LASRa was calculated by averaging data in all segments. Results Compared with controls, LAFS and mLASRs of HCM and HLVH were significantly higher ( P ＜0.05). Moreover, LAFS and mLASRs of HCM were significantly higher than HLVH (P ＜ 0.05). mLASRa correlated positively with LAFS of HCM and HLVH respectively ( r =0.81,0.88,all P ＜0.01). Conclusions The change of left atrial function of HCM and HLVH presented as pump function increased.

Objective To explore the changes of left atrial systolic function in patients with coronary heart disease after coronary artery bypass grafting (CABG). Methods Strain rate imaging (SRI) was performed on 23 patients with coronary heart disease before CABG, 1 week, 1 and 3 months after CABG to evaluate left atrial systolic function quantitatively. Results No significant change of left atrial systolic function was detected 1 week after CABG (P＞0.05 ). E/A and LVEF increased, LAFS, AEF and SRa decreased 1 month after CABG compared with those before CABG (P＜0.05). Three months after CABG, changes turned more significantly (P＜0.01). Left ventricular ejection fraction (LVEF) increased 1 and 3 months after CABG, and its changing rate negatively correlated with those of Sra (r=-0.751,-0.783; all P＜0.01). Conclusion Left atrial systolic function is affected by CABG, presenting as decrease of pump function. SRI can be used to evaluate the atrial systolic function quantitatively and monitor the changing of left atrial systolic function dynamically after CABG.

BACKGROUND: Running economy is considered as an important indicator of the performance of endurance athletes, especially long-distance runners. It is usually defined as the energy demand of running at a given speed, and expressed as the oxygen intake at a given speed. OBJECTIVE: To review the existing physiological and biomechanical factors affecting the running economy of runners. METHODS: With “running economy, physiological factors, biomechanical and neuromuscular characteristics, spatiotemporal factors, lower limb kinematic factors, kinetic factors, nutritional interventions” as search terms, PubMed database (1960-2018) was searched to include literatures related to running performance, acute or chronic interventions, and other influencing factors. RESULTS AND CONCLUSION: A total of 113 literatures were obtained. According to the inclusion and exclusion criteria, 58 literatures were analyzed. Current evidence shows that cardiopulmonary function, muscle fiber type, muscle strength, leg stiffness and other physiological factors are related to the improvement of running economy. However, there is no unified conclusion on the relationship between the temperature change of runners and the elastic potential energy and running economy. The biomechanical factors that are beneficial to improve running economy include stride frequency or length, vertical oscillation, lower limb moment of inertia, leg extension when toes are off the ground, and arm swing. However, the contact time between the feet and the ground, trunk inclination and other factors are inconsistent with running economy. Among other influencing factors, high-altitude adaptation can improve running economy; the relationship between extensibility and flexibility and running economy remains to be determined. Some nutritional interventions are also of concern, most notably dietary nitrates. Although most of the factors affecting running economy have been summarized in this paper, future studies can focus on individual runners in order to determine how the athlete’s structure and functional abilities affect running economy, as well as subsequent performance and athletic injuries.

The study of viruses traditionally focused on their roles as infectious agents and as tools for understanding cell biology. Recently, however, with the development of structural biology, viruses have now been receiving particular attention in nanotechnology. By chemical methods or by gene modification, viruses have been functionalized as potential building blocks for several applications, such as drug/gene delivery vehicles, advanced vaccine vehicles, and special inorganic or organic nanomaterials. Here we highlight some of the recent progresses in the medical applications of viruses.
Biomedical Research ; trends ; Gene Transfer Techniques ; Genetic Therapy ; Nanostructures ; Nanotechnology ; trends ; Vaccines ; Viruses

Objective To assess left ventricular(LV) longitudinal strain in patients with coronary heart disease by two-dimensional speckle tracking imaging (2DSTI),and to explore the clinical value of 2D longitudinal strain in detecting myocardial ischemia. Methods Forty-four patients with coronary heart disease (CHD group) and 28 age-matched subjects (control group) were enrolled into this study. The two-dimensional data were obtained in apical 4-chamble, 2-chamber and long axis view. And the longitudinal strains of every segments, the average longitudinal strain of LV 18 segments (SL18), the average longitudinal strain of 12 segments (SL12,excluded the 6 apical segments) were analyzed. Results In the patients with CHD, the longitudinal strain of ischemia segments and the global LV longitudinal strain were significantly decreased than that of the control subjects. Both in patients with CHD and in control subjects,the longitudinal strains in apical segments were higher than that of middle and basal segments. There was significant difference between SL18 and SL12 ( P=0.027 in CHD group and P =0.003 in control group).Receiver operating curve (ROC) analysis demonstrated that the cutoff point of SL18 to detect myocardial ischemia was - 18.8％ (sensitivity 80.2％ and specificity 74.1％ ) ,and the cutoff point of SL12 to detect myocardial ischemia was - 17.8％ ( sensitivity 81.7％ and specificity 85.6％ ). Conclusions 2D longitudinal strain was sensitive to detect myocardial ischemia, SL12 was better than SL18 in detecting myocardial ischemia. 2DSTI might be useful for identifying patients with severe CHD.

BACKGROUND: The researches of Pulling and Rotating Oblique Pulling Manipulation focus on clinical research and biomechanical changes of lumbar functional units, and the mechanical characteristics of manipulation are little reported.OBJECTIVE: To study the characteristics of the Pulling and Rotating Oblique Pulling Manipulation by digital method, so as to provide quantitative basis for inheritance, teaching and learning, promotion, and basic research of the manipulation.METHODS: The force-time curve and the force of the manipulators were tested and recorded with the multi-point membrane pressure measurement system. The kinetic parameters (the average load force, the average minimum force and the maximum impact force) were shown. The values of = the flip time, flip speed and impulse were measured by the test analysis system.RESULTS AND CONCLUSION: (1) The average load force was (145.86±34.80) N, duration was (1.43±0.46) s, the average minimum force was (72.24±13.87) N, the maximum impact force was (446.21±143.98) N, the flip time was (0.55±0.15) s, flip speed was (914.52±259.18) N/s, and the impulse was (256.21±82.30) N?s. (2) The rising slope of the impulse was (93.96±6.94), and the falling slope was (-82.70±26.10). (3) To conclude, the characteristics of manipulation from hand are analyzed in views of digitization, which provides an objective evaluation index for Lin's manipulation.

Objective To measure the thumb manipulative forces of Lin cervical rotation manipulation during cracking sounds,and provide quantitative basis for its inheritance,teaching and learning,promotion and basic research of the manipulation.Methods The thumb manipulative force of Lin cervical rotation manipulation and traditional cervical rotation manipulation during cracking sounds were tested and recorded with a multi-film pressure measurement system.Result There was statistically significant difference between the maximum thumb manipulative force of the hand used frequently and the hand used infrequently (P ＜ 0.05).The maximum thumb manipulative force of Lin cervical rotational manipulation is lower than the traditional cervical rotation manipulation (P ＜ 0.05).Conclusion Whether inIN traditional or Lin cervical rotation manipulation,the maximum thumb manipulative force of the hand used frequently is more than the hand used infrequently.Lin cervical rotation manipulation has better ergonomic characteristics of biological engineering,safer,more low energy consumption practices.