Via-PIXE Analysis of Elemental Composition of Plant Root Exposed to Environmental Stress

開始ページ、終了ページ: 冊子体のページ付

An Open Experiment of a Submilli-PIXE Camera

開始ページ、終了ページ: 冊子体のページ付

Direct visualization of a significant stenosis of the right coronary artery by transthoracic echocardiography. A case report

Non-invasive imaging of coronary arteries by transthoracic echocardiography is an emerging diagnostic tool to study the left main (LM), left descending artery (LAD), circumflex (Cx) and right coronary artery (RCA). Impaired coronary circulation can be assessed by measuring coronary velocity flow reserve (CVFR) by transthoracic Doppler echocardiography. Coronary artery stenoses can be identified as localized colour aliasing and accelerated flow velocities. We report a case with an acute coronary syndrome (ACS) of a 46-year-old man. With non-invasive imaging of coronary arteries by transthoracic echocardiography (TTE), we identified a segment of the mid right coronary artery (RCA) suggestive of stenosis with localized colour aliasing and accelerated flow velocity. We found a high ratio between the stenotic peak velocity and the prestenotic peak velocity, and a pathologic coronary flow velocity reserve (CFVR) distal to the stenosis in the posterior interventricular descending branch (RDP). Subsequent coronary angiography demonstrated one vessel disease with a stenosis in segment 3 of RCA, which was successfully treated with percutaneos coronary intervention PCI. Two weeks following the PCI procedure he was readmitted to hospital with chest pain. A subacute stent thrombosis was questioned, and repeated echocardiography was preformed. The mid portion of RCA showed normal and laminar flow. The CVFR of RCA measured in the RDP showed normal vasodilatory response, confirming an open RCA without any flow limitation. A repeated coronary angiogram demonstrated only a mild in stent intimal hyperplasia. This case illustrates the value of transthoracic echocardiography as a tool both in the diagnosis and the follow-up of chest pain disorders and coronary flow problems. Transthoracic echocardiography allows both direct visualization of the various coronary segments and assessment of the CVFR

RAPID-CYCLING POWER SUPPLIES FOR THE J-PARC RCS SEXTUPOLE MAGNETS

Abstract In the J-PARC 3-GeV synchrotron, the sextupole magnets were excited with DC-biased 25Hz sinusoidal waveform. Direct excitation for the rapid-cycling magnets causes large reactive power and voltage fluctuation in DC-link. This paper proposes design of the smoothing circuit for direct excitation of the rapid-cycling magnets. Especially, theoretical power-flow analysis shows a relationship between required DC-capacitance and voltage fluctuation in DC-link. Experimental results obtained from practical power-supply agree with analytical results