The relationship between cardiorespiratory fitness and inhibitory control following acute stress: An ERP study.

Although the relationships among acute stress, cardiorespiratory fitness (CRF), and cognitive function have been examined, whether CRF is related to behavioral and neuroelectric indices of inhibitory control following acute stress remains unknown. The purpose of the current study was to investigate the combined influence of acute stress and CRF on inhibitory control. Participants, aged 20-30 years, were stratified into the Higher-Fit (n = 31) and the Lower-Fit (n = 32) groups, and completed a Stroop task following the modified Maastricht Acute Stress Test (MAST) in the stress condition and the sham-MAST in the non-stress condition, during which electroencephalography was recorded. Behavioral (i.e., response time and accuracy) and neuroelectric (N2 and P3b components of the event-related potential) outcomes of inhibitory control were obtained. While the Higher-Fit group demonstrated shorter response times and higher accuracy than the Lower-Fit group following both the MAST and the sham-MAST, they also exhibited selective benefits of acute stress on inhibitory control performance (i.e., decreased response times and diminished interference scores). CRF-dependent alterations in neuroelectric indices were also observed, with the Higher-Fit group displaying smaller N2 and greater P3b amplitudes than the Lower-Fit group following the sham-MAST, and increased N2 and attenuated P3b amplitudes following the MAST. Collectively, these findings not only confirm the positive relationship between CRF and inhibitory control but also provide novel insights into the potential influence of CRF on inhibitory control and associated neuroelectric activity following acute stress.

Quantitative low-dose rest and stress CT myocardial perfusion imaging with a whole-heart coverage scanner improves functional assessment of coronary artery disease.

OBJECTIVE: We evaluated the diagnostic accuracy of myocardial blood flow (MBF) and perfusion reserve (MPR) measured from low-dose dynamic contrast-enhanced (DCE) imaging with a whole-heart coverage CT scanner for detecting functionally significant coronary artery disease (CAD). METHODS: Twenty one patients with suspected or known CAD had rest and dipyridamole stress MBF measurements with CT and SPECT myocardial perfusion imaging (MPI), and lumen narrowing assessment with coronary angiography (catheter and/or CT based) within 6 weeks. SPECT MBF measurements and coronary angiography were used together as reference to determine the functional significance of coronary artery stenosis. In each CT MPI study, DCE images of the whole heart were acquired with breath-hold using a low-dose acquisition protocol to generate MBF maps. Binomial logistic regression analysis was used to determine the diagnostic accuracy of CT-measured MBF and MPR (ratio of stress to rest MBF) for assessing functionally significant coronary stenosis. RESULTS: Mean stress MBF and MPR in ischemic segments were lower than those in non-ischemic segments (1.37 ±â€¯0.34 vs. 2.14 ±â€¯0.64 ml/min/g; 1.56 ±â€¯0.41 vs. 2.53 ±â€¯0.70; p < 0.05 for all). The receiver operating characteristic curve analysis revealed that MPR (AUC 0.916, 95%CI: 0.885-0.947) had a superior power than stress MBF (AUC 0.869, 95%CI: 0.830-0.909) for differentiating non-ischemic and ischemic myocardial segments (p = 0.045). On a per-vessel and per-segment analysis, concomitant use of MPR and stress MBF thresholds further improved the diagnostic accuracy compared to MPR or stress MBF alone for detecting obstructive coronary lesions (per-vessel: 93.4% vs. 83.6% and 88.5%, respectively; per-segment: 90.0% vs. 83.7% and 83.1%, respectively). The estimated effective dose of a rest and stress CT MPI study was 3.04 and 3.19 mSv respectively. CONCLUSION: Quantitative rest and stress myocardial perfusion measurement with a large-coverage CT scanner improves the diagnostic accuracy for detecting functionally significant coronary stenosis.

Role of multi-slice and three-dimensional computed tomography in delineating extracardiac vascular abnormalities in neonates.

BACKGROUND: Recent advances in multi-slice computed tomography (MSCT) and three-dimensional computed tomography (3D CT) provide good-resolution images and short scan time for complete diagnosis of congenital heart disease (CHD). In the present study, we found that MSCT rapidly provides clinically relevant information for diagnosing extracardiac vascular anatomy in neonates with CHD. It is less invasive, necessitating only minimum or no sedation and a relatively small amount of contrast material. These advantages are crucial, especially for critically ill neonates. METHODS: Between January 2007 and December 2008, MSCT scans were conducted on 41 neonates who were admitted to our neonatal intensive care unit. All the neonates were suspected to have complex CHD after an initial echocardiography examination. The scans were focused on detecting extracardiac vascular anatomy and abnormalities. All the image data sets were sent to image processing workstations for multiplanar interactive viewing and 3D reconstruction. RESULTS: High-resolution MSCT scan images were obtained from 41 patients. Reported indications and findings of extracardiac abnormalities and related structural anatomy pertaining to congenital heart disease from MSCT and 3D CT findings were confirmed by clinical and surgical findings by a team of multidisciplinary congenital heart disease specialists. CONCLUSION: Based on clinical and surgical confirmation of the MSCT scan results from a multidisciplinary congenital heart disease specialist team, we concluded that adequate information on CHD, specifically that regarding extracardiac abnormalities of the anatomy, can be obtained and MSCT can be used to replace cardiac catheterization.

Dissection of arteria lusoria by transradial coronary catheterization: a rare complication evaluated by multidetector CT.

An aberrant right subclavian artery (arteria lusoria) arising from the descending thoracic aorta is an uncommon congenital variant that occurs in about 0.2-1.7% of the population. In such cases, the angular course of the arteria lusoria to the ascending aorta imposes difficulty in passing a guide wire to the ascending aorta during right transradial catheterization. Here, we present the first report of an iatrogenic dissection of arteria lusoria during transradial coronary angiography evaluated by multidetector computed tomography. Computed tomography is useful for assessing the severity and extension of the dissection to guide the clinical management of this complication.

Synthesis and characterizations of nanometric-sized TiO2 powders as a photocatalyst for water splitting.

Nanometric-sized titanium oxide (TiO2) powders were synthesized through two emulsions method. In which two solutions of reverse emulsion, one containing Ti4+ chelated with citric acid/cellulose aqueous droplets and the other aqueous ammonia droplets, with the same water/oil (w/o) ratio are mixed together to form a slurry of titanium citrate precursor. Then the precursors were recovered and calcined to form TiO2 at various temperatures. The powders prepared from volume ratio of w/o at 1/100 had a relatively uniform and spherical with less aggregation. When the volume ratio of w/o was increased, the particle size had more aggregation and bigger. The particle sizes of powders obtained from volume ratio of 1/100 were estimated to be 6-8 nm. Finally, photocatalytic experiments for water splitting and producing hydrogen was examined in methanol solution by utilizing 65 mg nanometric-sized Pt (0.6 wt%)/TiO2 powder, and about 70 micromol hydrogen was produced in 6 h.