ABSTRACT
The radiation spectrum from the plasmas contains a large amount of information of plasmas. Thus, one of the most effective methods to detecting the plasma parameters is measure the plasma radiation spectrum. Until now, since the restriction of the Toshiba mechanically ruled aberration-corrected concave gratings, the measurable wavelength range of the incidence flat-field grazing spectrometer in the soft X-ray range are only from 5 to 40 nm. In order to extend the wavelength rang of grazing incidence flat-field spectrometer, first, a grazing incidence concave reflection grating ray-trace code is written using optical path equation. Second, under the same conditions with reference 6, we compare our numerical results with Harada's results. The results show that our results agree very well with the results of Harada. The results of comparison show that our ray-trace code is believable. Finally, the variety of the flat-field curves are detailedly investigated using the ray-trace code with the different grazing incidence conditions. The results show that the measurable wavelength range of the incidence flat-field grazing spectrometer are extended to 5~80 nm from the soft X-ray wavelength range of 5~40 nm. This result theoretically demonstrates the possibility of expanded the traditional band flat-field grazing incidence spectrometer from soft X-ray band to the extreme ultraviolet (XUV), and also bring a new design ideas for improving the use of grazing incidence flat field concave grating.
ABSTRACT
OBJECTIVE: To investigate the value of stress electrocardiography (S-ECG) and stress myocardial perfusion scintigraphy (S-MPS) in the differential diagnosis of patients with atypical chest pain. METHODS: Patients with atypical chest pain were undergone S-ECG, S-MPS, coronary angiography and coronary artery spastic provocation with intracoronary acetylcholine test. The final diagnoses of those patients were coronary heart disease, coronary spasm, coronary artery muscular bridge, microvascular angina pectoris and chest pain with non-coronary heart disease. Those patients were grouped by final diagnoses to retrospectively compare the results of S-ECG and S-MPS between groups. RESULTS: Totally 186 patients with integrated data were included. The final diagnoses were coronary artery stenosis (above 50% stenosis in diameter) in 20%, coronary artery spasm in 27%, coronary artery muscular bridge in 14%, microvascular angina pectoris in 5%, and chest pain with non-coronary artery disease in 34%. The sensitivity and specificity to diagnose ischemic coronary artery disease (including coronary stenosis, coronary artery muscular bridge and syndrome X but not coronary artery spasm) were 92% and 65% in S-ECG, 62% and 79% in S-MPS, respectively. Combination of atypical chest pain, negative S-ECG and reversal redistribution of S-MPS was an accurate non-invasive method to diagnose coronary artery spasm with sensitivity of 94% and specificity of 96%. CONCLUSIONS: Most of patients with atypical chest pain have organic or functional ischemic coronary artery disease. Combination of heart stress tests are helpful to differentiate the etiology of atypical chest pain.
