ABSTRACT
Nickelates are a rich class of materials, ranging from insulating magnets to superconductors. But for stoichiometric materials, insulating behavior is the norm, as for most late transition metal oxides. Notable exceptions are the 3D perovskite LaNiO3, an unconventional paramagnetic metal, and the layered Ruddlesden-Popper phases R4Ni3O10, (R = La, Pr, Nd). The latter are particularly intriguing because they exhibit an unusual metal-to-metal transition. Here, we demonstrate that this transition results from an incommensurate density wave with both charge and magnetic character that lies closer in its behavior to the metallic density wave seen in chromium metal than the insulating stripes typically found in single-layer nickelates like La2-xSrxNiO4. We identify these intertwined density waves as being Fermi surface-driven, revealing a novel ordering mechanism in this nickelate that reflects a coupling among charge, spin, and lattice degrees of freedom that differs not only from the single-layer materials, but from the 3D perovskites as well.
ABSTRACT
Total cholesterol and low-density lipoprotein (LDL) cholesterol exhibit an independent, strong, continuous correlation with cardiovascular events. The effectiveness of hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) in the treatment and prevention of atherosclerosis is well-established. However, despite the lowering of LDL targets and the increased use of statins, patients with type 2 diabetes mellitus (DM) continue to experience a higher proportion of adverse coronary artery disease events. This is as a result of an atherogenic dyslipidaemia, characterized by low levels of high-density lipoprotein and elevated plasma triglyceride concentrations, often with high levels of cholesterol-rich remnant particles. This article will review dyslipidaemia and its role in DM, and will discuss available treatment modalities that address residual cardiovascular risk in this disease.
Subject(s)
Atherosclerosis/prevention & control , Clofibric Acid/therapeutic use , Diabetes Complications/drug therapy , Dyslipidemias/drug therapy , Fatty Acids, Omega-3/therapeutic use , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Niacin/therapeutic use , Diabetes Mellitus/drug therapy , Drug Therapy, Combination , Dyslipidemias/complications , HumansABSTRACT
When indicated, artificial feeding in critically ill patients should be instituted as early and as simply as possible. If feasible, enteral feeding is preferable but a period of intravenous nutrition is usually necessary in the critically ill. A compounded feed, administered via a sterile single lumen subclavian catheter is recommended. The volume and electrolyte composition are centrally important. High nitrogen and relatively low caloric intake are more likely requirements in stressed patients. The most important supplements are water soluble vitamins (including folate) and the trace element zinc. Safe practice requires a system of monitoring and awareness of potential complications.