Alloy splitting of the Fe_Ga acceptor level in dilute Al_xGa_1−xN

The results of conventional deep-level transient spectroscopy (DLTS) and high-resolution Laplace DLTS measurements of the FeGa(0/−) acceptor level in dilute AlxGa1−xN layers (x ≤ 0.05) grown by MOVPE technique (metal-organic vapor phase epitaxy) on native ammono-GaN substrates are analyzed and discussed. It is shown that the electron emission signal related to the FeGa acceptor level in AlxGa1−xN splits into individual components due to aluminum fluctuations in the second-nearest neighbor (2NN) shell around the FeGa impurity atoms. The calculations of the probability of finding a given number of aluminum atoms in the 2NN shell of the FeGa defect agree well with the experimental concentrations determined from Laplace DLTS peak intensities. This finding shows that in dilute AlxGa1−xN layers grown by MOVPE, aluminum and iron atoms are randomly distributed in the material. Finally, we demonstrate that the energy level of the FeGa acceptor with no Al atoms in the 2NN shell in the AlxGa1−xN samples shifts linearly with the aluminum content and the shifts are 28 and 55 meV relative to that in GaN for the samples with x = 0.025 and 0.05, respectively.</p

Conductance Fluctuations in Microstructures of HgCdMnTe Bicrystals

Microscopic four-contact probes to semimagnetic HgCdMnTe grain-boundary inversion layers have been photolithographically patterned. Magnetoresistance measurements performed on these samples revealed aperiodic conductance fluctuations of the magnitude of the order of e$\text{}^{2}$/h. Quantitative analysis of both fluctuation amplitude and their mean period indicate that we have approached the mesoscopic regime in our system. This opens new possibilities in studies of spin-subsystem dynamics in semimagnetic semiconductors

Persisting thrombin activity in elderly patients with atrial fibrillation on oral anticoagulation is decreased by anti-inflammatory therapy with intensive cholesterol-lowering treatment

Item does not contain fulltextBACKGROUND: It has been demonstrated that the occurrence of ischemic stroke is more prevalent in AF patients, when increased levels of inflammatory markers are present. OBJECTIVE: The aim of this study was to evaluate the effect of intensive cholesterol lowering therapy on inflammatory markers and evidence of thrombotic in elderly AF patients treated with OAC. METHODS: 34 elderly patients (69-85 yrs) were randomized to double blind treatment with atorvastatin 40 mg plus ezetimibe 10 mg (n = 17) or double placebo (n = 17) for one year. All were anticoagulated with warfarin (target INR 2.5-3.5). Every 3 months inflammatory markers and parameters for evaluation of haemostatic and fibrinolytic activity were measured. RESULTS: Anti-inflammatory effects in the treatment arm were reflected by a significant decrease from baseline in hs-CRP, FGF, G-CSF, GM-CSF, IL-1ra, IL-9, IL-13, IL-17 and interferon-gamma (P < .05). There was no significant decrease in the control group. Endogenous thrombin potential was still present and active but decreased during treatment (P = .0005) compared to the placebo group. After 12 months treatment, a significant correlation was found between changes in endogenous thrombin potential and hs-CRP, interferon-gamma and G-CSF, respectively. No hemorrhagic complications occurred. CONCLUSION: Intensive cholesterol lowering significantly reduced inflammation and was accompanied by reduced thrombin generation. Larger clinical studies should determine which inflammatory markers are most specific and sensitive for estimating the inflammatory burden in these patients and at which corresponding thrombin activity level it is beneficial and safe to add intensive cholesterol lowering therapy even if normal cholesterol levels are present