Current status and development of percutaneous coronary intervention in China

##正##Dr.Gruntzig et al.(1979) successfully completed the world's first percutaneous coronary intervention (PCI),a percutaneous transluminal coronary     

Mathematical models of canine right and left atria cardiomyocytes

The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche(RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data.A model of right atria was then built by considering the differences between right atria and left atria.The two developed models well reproduced the exper...     

Neurochip based on light-addressable potentiometric sensor with wavelet transform de-noising

Neurochip based on light-addressable potentiometric sensor(LAPS),whose sensing elements are excitable cells,can monitor electrophysiological properties of cultured neuron networks with cellular signals well analyzed.Here we report a kind of neurochip with rat pheochromocytoma(PC12) cells hybrid with LAPS and a method of de-noising signals based on wavelet transform.Cells were cultured on LAPS for several days to form networks,and we then used LAPS system to detect the extracellular potentials with signals d...     

Congenital atresia of the left main coronary artery in an infant

Congenital atresia of the left main coronary artery is a rare occurrence, and surgical revascularizationbypass graft is required. We here report a rare case of congenital coronary anomaly in an infant. A 10-month-old male infant was admitted to the hospital with heart failure symptoms. Echocardiographic examinations revealed mitral valve regurgitation and ischemic changes of the anterolateral papillary muscle and chordae. Coronary angiography showed atresia of the left main coronary artery with a severe hypoplastic left anterior descending artery and a circumflex coronary artery. Unfortunately, sudden cardiac arrest occurred after catheterization and the infant did not recover despite of immediate cardiopulmonary resuscitation. Further studies are needed to find a newer diagnostic method to detect coronary anomaly in an infant, and coronary angiography, if necessary, has to be performed very carefully.     

Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system

This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–10⁷ Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system.     

Assessing the quality and equality of Hong Kong basic education results from PISA 2000+ to PISA 2006

This paper seeks to examine the quality and equality of basic education of Hong Kong based on the first three cycles of the Program for International Student Assessment (PISA). Results from these three assessments suggested that the Hong Kong students have an outstanding performance in mathematics, science and reading. In particular, the performance of reading improves substantially in PISA 2006. As far as equality in education is concerned, the achievement gap of students from different socio-economic backgrounds in Hong Kong is relatively small compared with other countries. However, the academic performance variation between-schools suggest that, there is still academic segregation among secondary schools in Hong Kong although it has been reduced slightly in the PISA 2006.     

Carbon steel slag as cementitious material for self-consolidating concrete

This study deals with the recycling of carbon steel slag （CSS） to produce self-consolidating concrete （SCC）. Since the chemical composition of CSS is similar to that of Portland cement or blast furnace slag （BFS）, it is expected to behave similarly. In the current study, the pozzolanic activity index of CSS is examined. Furthermore, the use of CSS as a pozzolanic material to partially replace Portland cement in the production of SCC is tested. We designed concrete mixtures with different water-to- cementitious material ratios （w/cm） keeping water and superplasticizer （SP） contents constant. Results showed that the design and performance of all the concrete mixtures used in this investigation were comparable to those of SCC and high performance con- crete （HPC）. However, compared to ordinary plain concrete （OPC）, the additional CSS content increases the setting time. In the CSS mixtures set for 90 d, compressive strengths of 86%, 134% and 121% were attained as compared to the control concrete; the corresponding w/cm ratios were 0.28, 0.32 and 0.40, respectively. Verifying the soundness of the SCC for meeting the criteria for HPC, the ultrasonic pulse velocity （UPV） of CSS was found to be comparable to that of ordinary concrete. In conclusion, the recycling of CSS can be advantageously employed in the production of SCC.     

Green’s functions for infinite planes and half-planes consisting of quasicrystal bi-materials

This paper deals with the combination of point phonon and phason forces applied in the interior of infinite planes and half-planes of 1D quasicrystal bi-materials. Based on the general solution of quasicrystals, a series of displacement functions are adopted to obtain Green＇s functions for infinite planes and bi-material planes composed of two half-planes in the closed form, when the two half-planes are supposed to be ideally bonded or to be in smooth contact. Since the physical quantities can be readily calculated without the need of performing any transform operations, Green＇s functions are very convenient to be used in the study of point defects and inhomogeneities in the quasicrystal materials.     

Dynamics of a prestressed Timoshenko beam subject to arbitrary external load

The free vibration and transient wave in a prestressed Rayleigh-Timoshenko beam subject to arbitrary transverse forces are analyzed by the newly developed method of reverberation-ray matrix （MRRM）. The effects of shear deformation and rotational inertia are taken into consideration. With a Fourier transform technique, the general wave solutions with two sets of unknown amplitude coefficients are obtained in the transformed domain for an unbonded prestressed beam under the action of arbitrary external excitations. From the coupling at joints and the compatibility of displacements in each member, the free and forced vibration responses of a beam with various boundary conditions are finally evaluated through certain numerical algorithms, Results are presented for a simply-supported beam subject to either a point fixed load or moving load. Good agreement with the finite element method （FEM） is obtained. The present work is instructive for high-speed railway bridge design and structural health monitoring.