10,136 research outputs found
Modified Glucose-Insulin-Potassium Regimen Provides Cardioprotection With Improved Tissue Perfusion in Patients Undergoing Cardiopulmonary Bypass Surgery
Background Laboratory studies demonstrate glucose-insulin-potassium (GIK) as a potent cardioprotective intervention, but clinical trials have yielded mixed results, likely because of varying formulas and timing of GIK treatment and different clinical settings. This study sought to evaluate the effects of modified GIK regimen given perioperatively with an insulin-glucose ratio of 1:3 in patients undergoing cardiopulmonary bypass surgery. Methods and Results In this prospective, randomized, double-blinded trial with 930 patients referred for cardiac surgery with cardiopulmonary bypass, GIK (200 g/L glucose, 66.7 U/L insulin, and 80 mmol/L KCl) or placebo treatment was administered intravenously at 1 mL/kg per hour 10 minutes before anesthesia and continuously for 12.5 hours. The primary outcome was the incidence of in-hospital major adverse cardiac events including all-cause death, low cardiac output syndrome, acute myocardial infarction, cardiac arrest with successful resuscitation, congestive heart failure, and arrhythmia. GIK therapy reduced the incidence of major adverse cardiac events and enhanced cardiac function recovery without increasing perioperative blood glucose compared with the control group. Mechanistically, this treatment resulted in increased glucose uptake and less lactate excretion calculated by the differences between arterial and coronary sinus, and increased phosphorylation of insulin receptor substrate-1 and protein kinase B in the hearts of GIK-treated patients. Systemic blood lactate was also reduced in GIK-treated patients during cardiopulmonary bypass surgery. Conclusions A modified GIK regimen administered perioperatively reduces the incidence of in-hospital major adverse cardiac events in patients undergoing cardiopulmonary bypass surgery. These benefits are likely a result of enhanced systemic tissue perfusion and improved myocardial metabolism via activation of insulin signaling by GIK. Clinical Trial Registration URL: clinicaltrials.gov. Identifier: NCT01516138
Spin-Orbit Coupled Insulators and Metals on the Verge of Kitaev Spin Liquids in Ilmenite Heterostructures
Competition and cooperation between electron correlation and relativistic
spin-orbit coupling give rise to diverse exotic quantum phenomena in solids. An
illustrative example is spin-orbit entangled quantum liquids, which exhibit
remarkable features such as topological orders and fractional excitations. The
Kitaev honeycomb model realizes such interesting states, called the Kitaev spin
liquids, but its experimental feasibility is still challenging. Here we
theoretically investigate hexagonal heterostructures including a candidate for
the Kitaev magnets, MgIrO, to actively manipulate the electronic and
magnetic properties toward realizing the Kitaev spin liquids. For three
different structure types of ilmenite bilayers MgIrO/TiO with =
Mn, Fe, Co, and Ni, we obtain the optimized lattice structures, the electronic
band structures, the stable magnetic orders, and the effective magnetic
couplings. We find that the spin-orbital coupled bands characterized by the
pseudospin 1/2 are retained in the MgIrO layer for all the
heterostructures, but the magnetic state and the band gap depend on the types
of heterostructures as well as the atoms. In particular, one type becomes
metallic irrespective of , while the other two are mostly insulating. We
show that the insulating cases provide spin-orbit coupled Mott insulating
states with dominant Kitaev-type interactions, accompanied by different
combinations of subdominant interactions depending on the heterostructural type
and , while the metallic cases realize spin-orbit coupled metals with
various doping rates. Our results indicate that these hexagonal
heterostructures are a good platform for engineering electronic and magnetic
properties of the spin-orbital coupled correlated materials, including the
possibility of Majorana Fermi surfaces and topological superconductivity
Global synchronization of chaotic Lur’e systems via replacing variables control
summary:Finding sufficient criteria for synchronization of master-slave chaotic systems by replacing variables control has been an open problem in the field of chaos control. This paper presents some recent works on the subject, with emphasis on chaos synchronization of both identical and parametrically mismatched Lur’e systems by replacing variables control. The synchronization schemes are formally constructed and two classes of sufficient criteria for global synchronization, linear matrix inequality criterion and frequency- domain criterion, are reviewed and discussed
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