Spectrum of classical two-dimensional Coulomb clusters.

The frequency spectrum of a system of classical charged particles interacting through a Coulomb repulsive potential and which are confined in a two-dimensional parabolic trap is studied. It is shown that, apart from the well-known center-of-mass and breathing modes, which are independent of the number of particles in the cluster, there are more "universal" modes whose frequencies depend only slightly on the number of particles. To understand these modes the spectrum of excitations as a function of the number of particles is compared with the spectrum obtained in the hydrodynamic approach.

A quasiclassical approach to strongly correlated quantum dots in intense magnetic fields.

We present a general quasiclassical description of parabolic many-electron quantum dots in the limit of high magnetic fields. The key points of our approach are the transition to a rotating frame of reference, in order to decouple rotational and vibrational modes, as well as the recognition and inclusion of the role of potential anisotropy felt by the vibrational modes. We are able to obtain the complete wavefunction of quantum dots containing any number of electrons in the Gaussian form, and present results concerning inter-particle correlation and deformation of large quantum dots.

Structure and spectrum of two-dimensional clusters confined in a hard wall potential.

The structural and dynamical properties of two-dimensional (2D) clusters of equally charged classical particles, which are confined in an external hard wall potential, are investigated through the Monte Carlo simulation technique. The ground-state configuration is investigated as a function of the interparticle interaction (Coulomb, dipole, logarithmic, and screened Coulomb). The excitation spectrum corresponding to the ground-state configuration of the system is discussed.

Structure and correlations in two-dimensional classical artificial atoms confined by a Coulomb potential.

The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of charged particles which, depending on the value of N and Z, may result in ring structures, hexagonal-type configurations, and for N/Z approximately 1 in an inner structure of particles which is separated by an outer ring of particles.

Aberrant vascularity and von Willebrand factor distribution in inflamed synovial membrane.

Objective: Von Willebrand factor (vWF) is an adhesive glycoprotein produced and secreted constitutively by endothelial cells. vWF is released upon endothelial stimulation and/or vascular injury, and mediates adhesion and aggregation of platelets. Our aim was to quantify synovial vasculature and to evaluate vWF distribution in situ in synovial membranes in various arthritides.

[Assessment of the possibility of using the photodynamic effect in rheumatology].

Results of the analysis of a number of parameters which determine the efficiency of using the photodynamic action for treating rheumatoid arthritis are reported. The investigations are based on determining the character of sensitizer stabilization in the joint tissue and evaluating its stability. As the sensitizer chlorin e6 was chosen.

[A new chondroprotector--polyvinylpyrrolidone for treating osteoarthrosis patients].

The authors demonstrate the role of chondroprotector therapy in the management of patients with osteoarthrosis (OA). They suggest the use of the polymeric drug polyvinylpyrrolidone as artificial synovial fluid. The drug is administered intra-articularly and is capable of replacing pathological synovial fluid.

[Levels of the C 4 component of the complement, lactoferrin and leukocytic thermostabile alpha glycoprotein during the treatment of patients with systemic rheumatic diseases].

The authors studied the dynamics of C4-component of complement (C4), lactoferrin (LF), leukocytic thermostable alpha-glycoprotein (LT alpha G) in the blood serum of 54 patients with rheumatoid arthritis, 32 patients with systemic lupus erythematosus, 8 patients with systemic vasculitis under the effect of hemosorption (HS), enterosorption (ES) and also immunosuppressants (IS). In severe forms of systemic rheumatic diseases the blood serum exhibits a decreased content of C4 but an elevated level of LF and LT alpha G. It has been established that HS is more active than ES or IS, and it influences the mechanisms of humoral immunity.

[Efficacy of polyvinylpyrrolidone solutions of various concentrations in patients with rheumatic diseases of the joints].

Twenty-six experimental animals, 93 patients with osteoarthrosis (OA) and 30 patients with rheumatoid arthritis (RA) were examined. Intraarticular injection of both 15% and 20% polyvinylpyrrolidone (PVP) solutions suppressed the development of experimental arthrosis in rabbits, which manifested in a decrease of the degenerative changes in the cartilaginous tissue of the joints. The clinical examination has demonstrated that the use of different concentrations of PVP produces an equally marked effect in OA.

[Clinico-immunologic analysis of sorption methods of treatment of rheumatoid arthritis and systemic lupus erythematosus].

The paper is concerned with the results of the application of the sorption methods for the treatment of patients with rheumatoid arthritis and systemic lupus erythematosus. The authors show the advisability of the use of the above methods for different variants of the disease course, define the time of the treatment and complications common to the sorption methods of the treatment. The results of the treatment by hemoperfusion and enterosorption are compared with the results of the patients' treatment with immunodepressants.

[Quantitative assessment of the status of patients with rheumatic diseases].

A system of operative quantitative assessment of the status of patients with rheumatoid arthritis (RA), osteoarthrosis (OA), systemic lupus erythematosus (SLE) and systemic scleroderma (SSD) was developed using a mathematical model of discriminant analysis. Data contained in case histories of 120 patients with RA, 112 with OA, 106 with SLE and 63 with SSD were used to determine discriminant coefficients of linear discriminant equations of some functional systems: locomotor, cardiovascular, respiratory, renal, digestive, nervous, skin and subcutaneous fat, immunological as well as laboratory findings on disease standing. Knowing discriminant coefficients, one can determine an index in any values of functional indicators that characterize the status of one or another system in any phase of the treatment of a patient.

[Cyclic AMP level in T- and B lymphocytes in patients with rheumatoid arthritis and systemic lupus erythematosus].

The content of cAMP in blood T and B lymphocytes was measured in 30 patients with rheumatoid arthritis (RA), 10 patients with systemic lupus erythematosus (SLE) and 28 donors. A statistically significant increase in the cAMP content in T lymphocytes of RA and SLE patients was established. On the contrary, in B lymphocytes of blood of RA patients and of SLE patients, in particular, the cAMP content was below normal.

[Various quantitative and qualitative characteristics of circulating immune complexes in rheumatic vasculitis].

Patients with rheumatoid arthritis and systemic lupus erythematosus associated with and without the clinical signs of the involvement of blood vessels were examined for the concentration of circulating immune complexes (CIC) and for the content of rheumatoid factor (RF), DNA and RNA as well as for the concentration of DNA, RNA and activity of acid nucleases in blood plasma. It was established that rheumatic vasculitis is coupled with a high concentration of CIC. In rheumatoid vasculitis, CIC contain a lot of rheumatoid factors which become far more activated after acidic dissociation of CIC.

[Artificial synovial fluid for the intra-articular treatment of rheumatoid arthritis and osteoarthritis (chemical synthesis and clinico-experimental and biomechanical data)].

Based on the clinical, experimental and biomechanical studies the authors suggest intraarticular treatment of rheumatoid arthritis (RA) and deforming osteoarthrosis (DOA) by means of artificial synovial fluid (ASF) developed with the use of polymers and biopolymers. Rheological studies performed with the use of a Rheotest-2 apparatus and ultrasonic interferometry of the samples of normal, RA, DOA synovial fluid and ASF demonstrated that medium-molecular-weight polyvinylpyrrolidone (PVP) and PVP hyaluronate appeared the most similar to natural synovial fluid, PVP-hyaluronate, PVP and its complexes with other drugs (cyclophosphamide, hydrocortisone, arteparone) were applied intraarticularly to the treatment of 520 patients with RA and DOA. The group of patients who received kenalog or placebo intraarticularly served as control.

[Effect of prostaglandin E2 on energy metabolism in isolated rat liver mitochondria].

Prostaglandin E2 at concentrations of 5.6 mM and 56 mM, in presence of EDTA 2.2 mM, did not affect the patterns of respiration and coupling, registered by means of polarographic procedure, in isolated rat liver mitochondria.