The effects of five item selection rules—Fisher information (FI), Fisher interval information (FII), Fisher information with a posterior distribution (FIP), Kullback-Leibler information (KL), and Kullback-Leibler information with a posterior distribution (KLP)—were compared with respect to the efficiency and precision of trait (Θ) estimation at the early stages of computerized adaptive testing (CAT). FII, FIP, KL, and KLP performed marginally better than FI at the early stages of CAT for Θ= -3 and -2. For tests longer than 10 items,there appeared to be no precision advantage for any of the selection rules.

No abstract

High-entropy alloys (HEAs) are a new class of solid-solution alloys that have attracted worldwide attention for their outstanding properties. Owing to the demand from transportation and defense industries, light-weight HEAs have also garnered widespread interest from scientists for use as potential structural materials. Great efforts have been made to study the phase-formation rules of HEAs to accelerate and refine the discovery process. In this paper, many proposed solid-solution phase-formation rules are assessed, based on a series of known and newly-designed light-weight HEAs. The results indicate that these empirical rules work for most compositions but also fail for several alloys. Light-weight HEAs often involve the additions of Al and/or Ti in great amounts, resulting in large negative enthalpies for forming solid-solution phases and/or intermetallic compounds. Accordingly, these empirical rules need to be modified with the new experimental data. In contrast, CALPHAD (acronym of the calculation of phase diagrams) method is demonstrated to be an effective approach to predict the phase formation in HEAs as a function of composition and temperature. Future perspectives on the design of light-weight HEAs are discussed in light of CALPHAD modeling and physical metallurgy principles.

A series of high entropy alloys (HEAs), Al x NbTiMoV, was produced by a vacuum arc-melting method. Their microstructures and compressive mechanical behavior at room temperature were investigated. It has been found that a single solid-solution phase with a body-centered cubic (BCC) crystal structure forms in these alloys. Among these alloys, Al 0.5 NbTiMoV reaches the highest yield strength (1,625 MPa), which should be attributed to the considerable solid-solution strengthening behavior. Furthermore, serration and crackling noises near the yielding point was observed in the NbTiMoV alloy, which represents the first such reported phenomenon at room temperature in HEAs.

ET increases the availability of vascular BH4 to attenuate O2. production and restores total antioxidant capacity, leading to improved NO-mediated vasodilation in Ovx rats.

No abstract

Wogonin is a flavonoid isolated from Scutellaria baicalensis Georgi, a traditional Chinese medicine, and it possesses antioxidant and anti-inflammatory effects. The aim of this study is to investigate the in vivo effect of wogonin on myocardial ischemia/reperfusion injury in an open-chest anesthetized rat model, which was induced by 45-minute left coronary artery occlusion and 2-hour reperfusion. Rats were treated with wogonin (5, 10, and 20 mg/kg, intraperitoneal) 40 minutes before ischemia or treatment with 10 mg/kg of wogonin 15 minutes after occlusion. Pretreatment with 10 mg/kg of wogonin significantly delayed the occurrence of ventricular premature contractions and tachycardia, and it suppressed the incidence of ventricular tachycardia and ventricular fibrillation, and mortality elicited by ischemia when compared with that in the control group, accompanied by reducing the arrhythmia scores. After 2-hour reperfusion, pretreatment and posttreatment with wogonin significantly reduced the infarct size and plasma levels of creatine kinase muscle-brain fraction and lactate dehydrogenase. Wogonin also significantly reduced the elevation of plasma tissue necrosis factor-α and superoxide anion production in the myocardium with ischemia/reperfusion. The expression of monocyte chemoattractant protein-1, phosphorylated p38 mitogen-activated protein kinase, p65 and IκBα, and active caspase-3 in ischemic myocardium pronouncedly increased in the control group; these were significantly attenuated by treatment with wogonin. In conclusion, wogonin demonstrated in vivo cardioprotective effects by the attenuation of the severity of ischemia-induced arrhythmias and irreversible ischemia/reperfusion injury, which is associated with its antioxidant capacity and anti-inflammatory effects. The suppression of nuclear factor-κB and p38 mitogen-activated protein kinase activation and the inhibition of monocyte chemoattractant protein-1 expression contribute to the beneficial effects of wogonin.

The accumulation of oxygen free radicals and activation of neutrophils are strongly implicated as pathophysiological mechanisms mediating myocardial ischemia/reperfusion injury. Heme oxygenase-1 (HO-1) has been reported to play a protective role in oxidative tissue injuries. In this study, the cardioprotective activity of tetramethylpyrazine (TMP), an active ingredient of Chinese medicinal herb Ligusticum wallichii Franchat, was evaluated in an open-chest anesthetized rat model of myocardial ischemia/reperfusion injury. Pretreatment with TMP (5 and 10 mg/kg, i.v.) before left coronary artery occlusion significantly suppressed the occurrence of ventricular fibrillation. After 45 min of ischemia and 1 h of reperfusion, TMP (5 and 10 mg/kg) caused a significant reduction in infarct size and induced HO-1 expression in ischemic myocardium. The HO inhibitor ZnPP (50 lg/rat) markedly reversed the anti-infarct action of TMP.