Objective To study the hemodynamics of central shunt (CS) by numerical simulation and investigate the effects of the elastic and rigid vessel wall on distributions of hemodynamic parameters in the vessel. Methods Two idealized CS models were constructed, one with a rigid wall (the rigid model) and the other with an elastic wall (the elastic model). Numerical calculation was conducted by the finite element method, and the elastic model adopted the fluid structure interaction. Results The distribution of flow velocity and pressure in both models were generally the same. About 68.9% of the aortic blood was directed into the pulmonary artery for the rigid model, as compared to 70% for the elastic model. The pressure drops within the shunt for the elastic model and rigid model were about 7.668 8 kPa and 7.222 3 kPa, respectively. The maximum variation in the average cross sections along the shunt was about 2.2% for the elastic model, appearing at the proximal end to side (ETS) anastomosis. The maximum difference of wall shear stress (WSS) between the two models at five key regions of each was about 16.1%. Conclusions Generally, the global flow structure in both the CS models remains unchanged; the elasticity of the vessel wall slightly influenced the flow distributions and pressure drop of the shunt; the effect from elasticity of the vessel wall on average cross sections along the shunt was higher at the proximal ETS anastomosis than that at the distal ETS anastomosis; the hypothesis that the vessel wall is rigid is acceptable in CS numerical simulations for the treatment of tetralogy of Fallot (TOF). However, the coupling of flow dynamics and wall mechanics may lead to a more reliable simulation result in the CS.

Echocardiogram is vital for the diagnosis of cardiac disease. The heart has complex hemodynamics requiring an advanced ultrasound imaging mode. Cardiac ultrasound vector flow imaging is capable of measuring the actual magnitude and direction of the blood flow velocity, obtaining the quantitative parameters of hemodynamics, and then providing more information for clinical research and diagnosis. This study mainly reviewed several different vector flow imaging techniques for cardiac flow and presented the implementation difficulties, and proposed a diverging wave based high frame rate cardiac ultrasound vector flow imaging. The study discussed the limitation of current ultrasound technology used in the cardiac flow measurement, analyzed and demonstrated the specific reasons for these implementation difficulties and the potential future development.
Blood Flow Velocity ; Heart/physiology* ; Hemodynamics ; Ultrasonography

Objective Modified B-T shunt (MBTS) and central shunt (CS) are two common surgical procedures for the treatment of tetralogy of fallot (TOF). The purpose is to analyze and compare the hemodynamic features of MBTS and CS. Methods 3D anatomy was reconstructed by medical images obtained from a patient with TOF, and two computational models were generated through virtual operations. A lumped parameter model was constructed to predict the post-operational boundary conditions. Computational fluid dynamics (CFD) was performed for the two models. Results A persistent pulmonary blood perfusion was observed in each model both during the systolic phase and diastolic phase, but the maximum velocities in the shunt were different for the two models. The pressure drop of the shunt in CS model was higher than that in MBTS model. The wall shear stress of the shunt in the MBTS model ranged unevenly from 0.025 to 340 Pa, while the wall shear stress in CS model ranged relatively evenly from 32.2 to 72.6 Pa. Conclusions Pulmonary artery blood was increased effectively for both options. The blood perfusion of right upper extremity was decreased in the MBTS model. More blood was directed into the pulmonary artery in CS model. Attention should be paid to the fact that the pressure gradient was large at the proximal anastomosis in both models in clinic. This study provides important theoretical references for surgeons to make choice from the surgery options in the treatment with TOF.

OBJECTIVE: Reduce the number of false alarms and measurement time caused by movement interference by the sync waveform of the movement. METHODS: Vital signal monitoring system based on motion sensor was developed, which collected and processed the vital signals continuously, optimized the features and results of vital signals and transmitted the vital signal results and alarms to the interface. RESULTS: The system was tested in many departments, such as digestive department, cardiology department, internal medicine department, hepatobiliary surgery department and emergency department, and the total collection time was 1 940 h. The number of false electrocardiograph (ECG) alarms decreased by 82.8%, and the proportion of correct alarms increased by 28%. The average measurement time of non-invasive blood pressure (NIBP) decreased by 16.1 s. The total number of false respiratory rate measurement decreased by 71.9%. CONCLUSIONS False alarms and measurement failures can be avoided by the vital signal monitoring system based on accelerometer to reduce the alarm fatigue in clinic.
Humans ; Monitoring, Physiologic ; Electrocardiography ; Arrhythmias, Cardiac ; Blood Pressure ; Accelerometry ; Clinical Alarms

Objective In order to improve the local hemodynamics of coronary artery bypass graft and reduce the incidence of restenosis, a double-bypass-graft design was proposed to alleviate artery stenosis. Methods Based on finite element method, the hemodynamics of the conventional bypass graft model and the double-bypass-graft model was adopted for numerical simulation. The distributions of hemodynamics such as flow field and wall shear stress in the vicinity of anastomosis were calculated. Results This new design provided better hemodynamics near the main anastomosis region, eliminated the vortex and flow stagnation, and increased the wall shear stress at the artery floor. The axial length of vortex near the assistant bypass graft by this new design was only 3 mm, which was shorter than that of 4.5 mm in the conventional design. Nearly 36% of the total blood was directed into the assistant bypass graft. Conclusions The new design could help to reduce the incidence of intimal hyperplasia.

OBJECTIVETo investigate patterns of action potential firing in cortical heurons of neonatal mice and their electrophysiological properties.

METHODSThe passive and active membrane properties of cortical neurons from 3-d neonatal mice were observed by whole-cell patch clamp with different voltage and current mode.

RESULTSThree patterns of action potential firing were identified in response to depolarized current injection. The effects of action potential firing patterns on voltage-dependent inward and outward current were found. Neurons with three different firing patterns had different thresholds of depolarized current. In the morphology analysis of action potential, the three type neurons were different in rise time, duration, amplitude and threshold of the first action potential evoked by 80 pA current injection. The passive properties were similar in three patterns of action potential firing.

CONCLUSIONThese results indicate that newborn cortical neurons exhibit different patterns of action potential firing with different action potential parameters such as shape and threshold.

OBJECTIVE: To investigate the lexical tone perception and quality of life of Nurotron cochlear implant users. METHOD: Forty-nine adult cochlear implant users participated in this study. Mandarin tone identification test developed by Beijing Institute of Otolaryngology was used to evaluate the tone perception. Nijmegen cochlear im plantation questionnaire (NCIQ) was administered to quantify the quality of life. RESULT: (1) The average scores of tone perception in quiet was 67.26%. The tone perception rates under quiet condition for all cochlear implant recipients were higher than the opportunity level. (2) The average scores of tone perception under noisy condition was 51.92%. Exc ept for two recipients, the tone perception rates under noise condition for the rest recipients were better than chance. (3) The confusion patterns of tone recognition showed that Tone 3 was the easiest tone to perceive. (4) The postimplant scores for the total , basic sound perception, advanced sound perception, speech pro duction, self-esteem, activity and social interactions of NCIQ were 55.4, 72.4, 54.0, 63.4, 50.7, 47.3 and 44.7, respectively. CONCLUSION The Nurotron cochlear implant users had the ability for lexical tone perception and had an improvement in quality of life after cochlear implantation.
Adolescent ; Adult ; Cochlear Implantation ; Cochlear Implants ; Female ; Humans ; Male ; Middle Aged ; Quality of Life ; Speech Perception ; Surveys and Questionnaires ; Young Adult

Pueraria lobata is one of the most important medicinal herbs used traditionally in China. According to Shanghan Lun (Treatise on Exogenous Febrile Disease), it has been used traditionally to relieve body heat, eye soring, dry mouth, headache associated with high blood pressure, and stiff neck problems. Modern studies in the 1970s revealed that isoflavonoids extracted from P. lobata were the bioactive components of an herbal remedy namely Yufeng Ningxin Tablets for the treatment of patients after stroke. This article reviews recent application of P. lobota in the treatment of diabetics and in reducing alcohol drinking. In view of its low toxicity profile, P. lobota stands an excellent chance to be developed as a phytomedicine for treating human diseases.

Objective To investigate the feasibility of multiple real-time PCR for the detection of Fritillariae Cirrhosae Bulbus and adulterants. Methods Based on the analysis of interspecies variation, genetic distance and phylogenetic relationship of ITS, psbA-trnH, rbcL and matK gene sequences, the genes with fast evolution rate, big interspecies variation and small intraspecies variation were selected as target genes. Fritillariae Cirrhosae Bulbus and adulterants specific primers and Taqman probes were designed to establish a multiplex real-time PCR assay. Methods were evaluated by comparison of specificity, sensitivity and mixed sample detection and sequencing. Results The ITS and psbA-trnH mutations were higher than rbcL and matK, and rbcL and matK were significantly lower than ITS and psbA-trnH genes by genetic distance analysis. And the sensitivity of the establish multiple real-time PCR using ITS as the target gene was 0.01 ng. Four samples of adulterants were detected in 18 samples, and the results were consistent with the results of NJ tree clustering analysis. Conclusion Based on the IIS region sequence as the target gene to establish multiple real-time fluorescence PCR detection method can successfully identify Fritillariae Cirrhosae Bulbus and its counterfeit goods, which provides a new basis for the authenticity of identification.

The accelerometry(AMG) muscle relaxant monitor is the most widely used quantitative muscle relaxant monitor to assess the degree of neuromuscular at present. In this study, the ulnar nerve was stimulated by using train of four stimulation(TOF) mode of the AMG muscle relaxant monitor, and the movement of the adductor pollicis muscle was monitored. In this way, the distribution range of key parameters (acceleration peak value, response time, and TOF ratio) of the adductor pollicis muscle during the use of muscle relaxant in clinical practice is analyzed and will provide a practical basis for the development and improvement of the muscle relaxant monitor.
Electric Stimulation ; Muscle, Skeletal ; Neuromuscular Blockade ; Neuromuscular Nondepolarizing Agents ; Ulnar Nerve/physiology*