Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Dual role of lipoproteins in endothelial cell dysfunction in atherosclerosis.

Abstract: The endothelium is a key constituent of the vascular wall, being actively involved in maintaining the structural integrity and proper functioning of blood vessels. Hyperlipidemia, diabetes, hypertension, smoking and aging are important risk factors for the dysfunction of endothelial cells (EC). Circulating lipoproteins (Lp) synthesized and secreted from the intestine or liver have an important role in supplying peripheral tissues with fatty acids from triglyceride rich lipoproteins (TGRLp) for energy production or storage, and cholesterol from low density lipoproteins (LDL) or high density lipoproteins (HDL) for the synthesis of cellular membranes and steroid hormones. Under pathological conditions, Lp may suffer alterations in concentration and composition and become aggressors for EC. Modified LDL, remnant Lp, TGRLp lipolysis products, dysfunctional HDL are involved in the changes induced in EC morphology (reduced glycocalyx, overdeveloped endoplasmic reticulum, Golgi apparatus and basement membrane), loose intercellular junctions, increased oxidative and inflammatory stress, nitric oxide/redox imbalance, excess Lp transport and storage, as well as loss of anti-thrombotic properties, all of these being characteristics of endothelial dysfunction. Normal HDL are able to counteract the harmful effects of atherogenic Lp in EC but under persistent pathological conditions they lose the protective properties and become pro-atherogenic. This review summarises recent advances in understanding the role of Lp in the induction of endothelial dysfunction and the initiation and progression of atherosclerotic lesions. Its main focus is the antagonistic role of atherogenic Lp (LDL, VLDL, dysfunctional HDL) versus anti-atherogenic Lp (HDL), also pointing out the potential targets for arresting or reversing this process.

Existence and Non-Existence Results for Quasilinear Elliptic Exterior Problems with Nonlinear Boundary Conditions

Abstract: Existence and non-existence results are established for quasilinear elliptic problems with nonlinear boundary conditions and lack of compactness. The proofs combine variational methods with the geometrical feature, due to the competition between the different growths of the nonlinearities.

Angiotensin peptides and their pleiotropic actions.

Abstract: The concept of tissue renin-angiotensin systems (RAS) is now well established and it is now usual to think in terms of renal and tissue systems. At the same time it has emerged that angiotensin II (Ang II) is not the only biologically active peptide generated by the RAS. At least three others have been identified: the heptapeptide Ang III, the hexapeptide Ang IV and Ang 1-7. Specific receptors exits for the last two peptides. In addition, the range of possible physiological and pathophysiological properties for Ang II has been expanding. The current perception of the RAS is therefore that of a much more complex system than previously believed, with autocrine, paracrine and endocrine properties extending beyond the cardiovascular system. This mini-review focuses on the synthetic pathways of the Ang peptides and describes some of their pleiotropic actions.

Lattice Boltzmann simulation of thermal nonideal fluids.

Abstract: A thermal lattice Boltzmann model for a van der Waals fluid is proposed. In the continuum, the model reproduces at second order of a Chapman-Enskog expansion, the theory recently introduced by A. Onuki [Phys. Rev. Lett. 94, 054501 (2005)]. Phase separation has been studied in a system quenched by contact with external walls. Pressure waves favor the thermalization of the system at initial times and the temperature, soon with respect to typical times of phase separation, becomes homogeneous in the bulk. Alternate layers of liquid and vapor form on the walls and disappear at late times.