Beam charge integration in external beam PIXE–PIGE analysis utilizing proton backscattering with an extraction window

In this study,we present a new method for the indirect integration of beam charges in external beam proton-induced X-ray emission and proton-induced c-ray emission(PIXE–PIGE) analysis.We recorded proton spectra backscattered by a Kapton film extraction window in different sample situations and under different beam currents.We also simulated backscattering spectra using the simulation of backscattering spectra program(SIMNRA).We determined that in a specific geometrical arrangement,different sample situations did not significantly affect factor C_Q(the ratio between integral backscattering proton counts and integral beam charges).We also studied the reproducibility and beam current dependence of factor C_Q.The statistic factor of C_Q was28.95 ± 0.6 kilo counts/l C,with a relative standard deviation of 2.0 %.Significantly,in external beam PIXE–PIGE analysis,we were able to calculate beam charge integration from the integral backscattering proton counts in an energy region.

Ventricular tachycardia originating from the His bundle: A case report

BACKGROUND Ventricular tachycardia(VT)commonly occurs among patients with heart failure and can even cause sudden cardiac death.VT originating from the His bundle branch has been rarely reported.We present the case of a patient with VT from the His bundle branch.CASE SUMMARY A 58-year-old female complained of paroxysmal palpitations and dizziness for approximately 6 mo.She had a history of fatty liver and cholecystitis,and carotid atherosclerosis could not be excluded from the ultrasound results.An evaluation of the electrocardiogram obtained after admission showed spontaneous conversion between two different morphologies.The possible electrophysiologic mechanism suggested that the dual-source VT originated from the same source,the His bundle branch.Finally,the His bundle branch was ablated,and a dualchamber pacemaker was inserted into the patient’s heart.No further VT occurred during the 3-year follow-up after hospital discharge.CONCLUSION The diagnosis of VT originating from the His bundle is rare and difficult to establish.The results of this study showed VT originating from the His bundle based on a careful evaluation of the electrocardiogram,and the diagnosis was confirmed by an intracardiac electrophysiologic examination.