Laser two-photon Ionization of several aromatic molecules In hexane has been carried out with the fourth harmonics (266 nm) of a Nd-YAG laser as an excitation source. The photolonlzatlon current Is quadratlcally proportional to the laser pulse energy, Indicating two-photon Ionization. There Is a large blank signal due to the solvent (hexane) Ionization, and H has been canceled with a differential technique. The effect of laser pulse energy fluctuation has been corrected by an on-line normalization procedure. The photolonlzatlon current also depends on the molar absorptivity of the molecule, and the first step to Ionization should be excitation at 266 nm above the ground state. The detection limit ranges from 3.8 ppb for benzene to 61 ppt for pyrene. Analytical curves were linear for at least 3 orders of magnitude above the detection limits.
The laser power dependence of the transient current induced by the pulsed laser irradiation on pyrene in n-hexane was measured. The peak time of the current decreased with increasing the produced charge. This result was inconsistent with a theoretical prediction on the space charge effect, and showed the electric field inhomogeneity was important.
Objectives: Endovascular aneurysm repair (EVAR) is currently the most common treatment of abdominal aortic aneurysms (AAA). Potential predictors of long-term survival after EVAR include assessment of physiologic, functional, and cognitive status. Objective radiographic findings, such as skeletal muscle atrophy, or sarcopenia, may be an additional measure. This study investigated sarcopenia as a method of predicting a primary outcome of survival for patients undergoing EVAR.Methods: A retrospective review was conducted of all patients who underwent elective EVAR from October 2002 to June 2014. Patients with an available periprocedural computed tomography (CT) scan, clinical data, and long-term outcomes were included in the analysis. Skeletal muscle mass was measured on CT using the cross-sectional psoas muscle area at the third lumbar vertebral level normalized to the square of the patient's height. Patients were divided into quartiles based on normalized total psoas area (TPA). Kaplan-Meier estimates for our primary outcome and univariate analysis for multiple secondary outcomes were performed. A threshold for optimal estimate of sarcopenia was determined using a receiver operating characteristic curve.Results: A total of 272 EVAR treated patients were evaluated, including 237 men and 35 women, with a median age of 72 years (interquartile range, 67-78 years) and mean body mass index of 28.9 kg/m 2 . Median aneurysm diameter was 58 mm, and median TPA was 6.47 (interquartile range, 5.31-7.92). There was no difference in 30-day mortality (quartile [Q]
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