Magnetic anisotropies of obliquely evaporated Co films

The magnetic anisotropies of obliquely evaporated Co films were studied using ferromagnetic resonance. The coercive force (H/sub c/) increases rapidly beyond the incidence angle of /spl eta/=60/spl deg/. The remanence ratio (M/sub r//M/sub s/) along the parallel axis at 0/spl deg/ is 0.55-0.7 and comes to a minimum at /spl eta/=30--60/spl deg/. For 1000-/spl Aring/ films deposited at /spl eta/=75/spl deg/, oblique anisotropy field of H/sub k1/=4.9 kOe, in-plane anisotropy field of H/sub k2/=3 kOe and tilt angle of /spl alpha/=28/spl deg/ were observed; this film has H/sub c/=800 Oe and M/sub r//M/sub s/=0.95.</p

Postischemic infusion of sivelestat sodium hydrate, a selective neutrophil elastase inhibitor, protects against myocardial stunning in swine.

PURPOSE: It seems controversial whether or not neutrophil elastase inhibitors are effective in attenuating myocardial ischemia/reperfusion injury. We thus investigated possible protective effects of sivelestat, a neutrophil elastase inhibitor, against myocardial stunning i.e., prolonged myocardial dysfunction following a brief episode of ischemia. METHODS: Swine were divided into control group (group C), low-dose sivelestat group (group L), and high-dose sivelestat group (group H) (n = 7 for each group). All the swine were subjected to myocardial ischemia through ligation of the left anterior descending (LAD) coronary artery for 12-min, followed by 90-min reperfusion. Sivelestat was infused intracoronally at concentrations of 6 and 60 mg/ml throughout the reperfusion period in groups L and H, respectively, while saline was infused in the group C. Heart rate (HR), left ventricular developed pressure (LVdP), maximum rate of LVdP (LVdP/dt (max)), LV end-diastolic pressure (LVEDP), percentage of segment shortening (%SS, an index of regional myocardial contractility), and coronary venous interleukin-6 concentration in the LAD perfusion area were measured before ischemic induction and during reperfusion. RESULTS: The ischemia/reperfusion insult did not cause any significant changes in HR, LVdP, LVdP/dt (max), and LVEDP in all groups. However, it significantly reduced %SS in the LAD perfusion area and increased the interleukin-6 concentration in group C. Those changes in %SS and the interleukin-6 concentration were both greatly attenuated, but not prevented, in groups L and H. CONCLUSION: Sivelestat presumably attenuates myocardial contractile dysfunction due to myocardial stunning by inhibiting neutrophil-derived elastase, thereby suppressing the production of interleukin-6 in activated neutrophils

Direct protective effects of dexmedetomidine against myocardial ischemia-reperfusion injury in anesthetized pigs

Systemic administration of α2-adrenergic agonists has been shown to protect ischemic myocardium, but the direct effects on ischemia-reperfused myocardium have not yet been clarified. This study was carried out to determine the effects of intracoronary dexmedetomidine (DEX) on the myocardial ischemia-reperfusion injury in anesthetized pigs. In open-chest pigs, the left anterior descending coronary artery was perfused through an extracorporeal circuit from the carotid artery. They received intracoronary infusion of DEX at a rate of 1 ng • mL -1 (group LD, n = 9), 10 ng • mL -1 (group MD, n = 9), or 100 ng • mL -1 (group HD, n = 9) of coronary blood flow or vehicle (group C, n = 12) for 30 min before ischemia. Myocardial stunning was produced by 12-min ischemia of the perfused area of left anterior descending coronary artery and 90-min reperfusion. The effect on reperfusion-induced arrhythmias was evaluated using the incidence of ventricular tachycardia or fibrillation after reperfusion. Regional myocardial contractility was evaluated with segment shortening (%SS). Dexmedetomidine significantly reduced the incidence of reperfusion-induced ventricular arrhythmias. Dexmedetomidine significantly improved the recovery of percentage segment shortening at 90 min after reperfusion (32.6% ± 3.1% in group C, 58.2% ± 2.1% in group LD, 61.1% ± 1.8% in group MD, and 72.0% ± 2.0% in group HD). Dexmedetomidine suppressed the increase in plasma norepinephrine concentration after reperfusion. The results indicate that DEX would exert the protective effect against ischemia-reperfusion injury by the direct action on the myocardium, which is not mediated through the central nervous system

Inhalation of hydrogen gas protects against myocardial stunning and infarction in swine

Objectives. The present study was carried out to determine whether inhalation of hydrogen (H 2) gas protects myocardium against ischemia-reperfusion (I/R) injury in swine. Design. In anesthetized open-chest swine, myocardial stunning was produced by 12-minute occlusion of left anterior descending coronary artery (LAD) followed by 90-minute reperfusion in the first study. Group A inhaled 100% oxygen, and group B inhaled 2% H 2 plus 98% oxygen during ischemia and reperfusion. In the second study, myocardial infarction was produced by 40-minute occlusion of LAD followed by 120-minute reperfusion. Group C inhaled 100% oxygen during ischemia and reperfusion. Group D inhaled 2% H 2 plus 98% oxygen. Group E inhaled 4% H 2 plus 96% oxygen. Results. The change of segment shortening (%SS) from baseline at 90 minutes after reperfusion in group B was 74±13 (mean ± SD) %, which was significantly higher than that in group A (48±15%). Myocardial infarct size in group E (32±10%), but not in group D (40±9%) was smaller than that in group C (46±6%). Conclusions. Inhalation of 2% H 2 gas improves myocardial stunning, and inhalation of 4% but not 2% H 2 gas reduces myocardial infarct size in swine

Postoperative coagulation profiles of patients undergoing adult-to-adult living donor liver transplantation?A single-center experience

Objective: To characterize the pre- and postoperative coagulation profiles of patients undergoing adult-to-adult living donor liver transplantation (LDLT), using various coagulation tests and rotational thromboelastometry (ROTEM). Methods: This single-center observational study evaluated the various coagulation profiles of 22 patients (13 men and 9 women). Blood samples were obtained immediately after the induction of anesthesia (PRE) and on postoperative days (PODs) 1, 3, 5, and 7 after LDLT surgery. Results: Most procoagulant factors (fibrinogen, platelet, and coagulation factors II, VII, VIII, and IX) improved to levels equal to or greater than the PRE levels on POD 7. The levels of von Willebrand factor significantly increased after surgery, whereas those of disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13 decreased. Although the thrombin-antithrombin III complex increased immediately after surgery, the plasmin-α 2 plasmin inhibitor complex increased only on POD 7. The level of plasminogen activator inhibitor-1 increased on POD 1, returning to PRE levels on POD 3. Almost all ROTEM parameters were decreased or prolonged, compared to the PRE levels, on POD 7. Conclusions: The values of most coagulation tests showed the improvement or acceleration of coagulability on POD 7 than at PRE, with almost all the ROTEM parameters decreased or prolonged. Therefore, it cannot be concluded whether ROTEM reflects the net effect of hemostatic balance after liver transplantation

Magnetic anisotropies of obliquely evaporated Co films Magnetic Anisotropies of Obliquely Evaporated Co Films

The magnetic anisotropies of obliquely evaporated Co films were studied using ferromagnetic resonance. The coerceive force ( ) increases rapidly beyond the incidence angle of = 60 . The remanence ratio ( ) along the parallel axis at 0 is 0.55-0.7 and comes to a minimum at = 30-60 . For 1000-A films deposited at = 75 , oblique anisotropy field of 1 = 4 9 kOe, in-plane anisotropy field of 2 = 3 kOe and tilt angle of = 28 were observed; this film has = 800 Oe and = 0 95

Magnetic anisotropies of obliquely evaporated Co films

The magnetic anisotropies of obliquely evaporated Co films were studied using ferromagnetic resonance. The coercive force (H/sub c/) increases rapidly beyond the incidence angle of /spl eta/=60/spl deg/. The remanence ratio (M/sub r//M/sub s/) along the parallel axis at 0/spl deg/ is 0.55-0.7 and comes to a minimum at /spl eta/=30--60/spl deg/. For 1000-/spl Aring/ films deposited at /spl eta/=75/spl deg/, oblique anisotropy field of H/sub k1/=4.9 kOe, in-plane anisotropy field of H/sub k2/=3 kOe and tilt angle of /spl alpha/=28/spl deg/ were observed; this film has H/sub c/=800 Oe and M/sub r//M/sub s/=0.95.</p

Magnetic anisotropies of obliquely evaporated Co films

The magnetic anisotropies of pure Co films were studied. The in-plane magnetic properties were measured using vibrating sample magnetometer. The coercive force (H/sub c/), saturation magnetization (M/sub s/) and the remanence ratio (M/sub r//M/sub s/) were measured with varying incident angle (/spl eta/). The magnetic anisotropy was determined by ferromagnetic resonance.</p