Parallel updating cellular automaton models of driven diffusive Frenkel-Kontorova-type systems

Three cellular automaton (CA) models of increasing complexity are introduced to model driven diffusive systems related to the generalized Frenkel-Kontorova (FK) models recently proposed by Braun [Phys.Rev.E58, 1311 (1998)]. The models are defined in terms of parallel updating rules. Simulation results are presented for these models. The features are qualitatively similar to those models defined previously in terms of sequentially updating rules. Essential features of the FK model such as phase transitions, jamming due to atoms in the immobile state, and hysteresis in the relationship between the fraction of atoms in the running state and the bias field are captured. Formulating in terms of parallel updating rules has the advantage that the models can be treated analytically by following the time evolution of the occupation on every site of the lattice. Results of this analytical approach are given for the two simpler models. The steady state properties are found by studying the stable fixed points of a closed set of dynamical equations obtained within the approximation of retaining spatial correlations only upto two nearest neighboring sites. Results are found to be in good agreement with numerical data.Comment: 26 pages, 4 eps figure

Дослідження фізико-хімічних, протимікробних властивостей лікарського препарату “декаметоксин”

In the article there were presented the results of the research of medical physical and chemical qualities of domestic remedy “Decamethoxin®” (Decamethoxinum®), produced by Pilot Manufacturing of Institute of Organic Chemistry of National Academy of Sciences of Ukraine. It was found, that “Decamethoxin®” (DC M) remedy complies physical and chemical requirements (color, transmittance, specific optical rotation, entertainable amount of impurities, sulfate ash, heavy metals, residual amounts of organic substances, the loss of the weight no more than 4.5 %, while desiccation), established for patented exemplar of decamethoxin®. Kinetics of DCM® elution into water medium from medical materials was proved. There was found, that elution of DCM® proceeded long (for 15 days), it was like programmed controlled process, occurring due to diffusion and kinetic mechanisms.статье приведены результаты исследования медицинских, физико-химических свойств отечественного лекарственного препарата “Декаметоксин®” (Decamethoxinum®) опытного производства Института органической химии Национальной академии наук Украины. Установлено, что лекарственныйпрепарат“Декаметоксин®” (ДКМ ®) соответствует  установленным для патентированного образца ме-дицинским, физико-химическим требованиям (окраска, прозрачность, растворимость, удельное оптиче-ское вращение, допустимое количество сопутствующих примесей, сульфатная зола, тяжелые металлы, остаточное количество органических веществ, потеря при высушивании не более 4,5 % массы). Дока-зано кинетику высвобождения ДКМ ® в водную среду из медицинских материалов. Установлено длитель-ное (15 суток) программированное контролируемое высвобождение ДКМ ®, которое протекает по диффузионно-кинетическому механизмуУ статті наведено результати дослідження медичних, фізико-хімічних властивостей вітчизняного лікарського препарату “Декаметоксин®” (Decamethoxinum®) дослідного виробництва Інституту органічної хімії Національної академії наук України. Встановлено, що лікарський препарат “Декаметоксин®” (ДКМ ®) відповідає встановленим для патентованого взірця медичним, фізико-хімічним вимогам (забарвлення, прозорість, розчинність, питоме оптичне обертання, допустима кількість супровідних домішок, сульфатна зола, важкі метали, залишкова кількість органічних речовин, втрата при висушуванні не більше 4,5 % маси). Доведено кінетику вивільнення ДКМ ® у водне середовище з медичних матеріалів. Встановлено тривале (15 діб) програмоване контрольоване вивільнення ДКМ ®, яке перебігає за дифузійно-кінетичним механізмом

On the driven Frenkel-Kontorova model: I. Uniform sliding states and dynamical domains of different particle densities

The dynamical behavior of a harmonic chain in a spatially periodic potential (Frenkel-Kontorova model, discrete sine-Gordon equation) under the influence of an external force and a velocity proportional damping is investigated. We do this at zero temperature for long chains in a regime where inertia and damping as well as the nearest-neighbor interaction and the potential are of the same order. There are two types of regular sliding states: Uniform sliding states, which are periodic solutions where all particles perform the same motion shifted in time, and nonuniform sliding states, which are quasi-periodic solutions where the system forms patterns of domains of different uniform sliding states. We discuss the properties of this kind of pattern formation and derive equations of motion for the slowly varying average particle density and velocity. To observe these dynamical domains we suggest experiments with a discrete ring of at least fifty Josephson junctions.Comment: Written in RevTeX, 9 figures in PostScrip

Effect of Systemic Hypertension With Versus Without Left Ventricular Hypertrophy on the Progression of Atrial Fibrillation (from the Euro Heart Survey).

Hypertension is a risk factor for both progression of atrial fibrillation (AF) and development of AF-related complications, that is major adverse cardiac and cerebrovascular events (MACCE). It is unknown whether left ventricular hypertrophy (LVH) as a consequence of hypertension is also a risk factor for both these end points. We aimed to assess this in low-risk AF patients, also assessing gender-related differences. We included 799 patients from the Euro Heart Survey with nonvalvular AF and a baseline echocardiogram. Patients with and without hypertension were included. End points after 1 year were occurrence of AF progression, that is paroxysmal AF becoming persistent and/or permanent AF, and MACCE. Echocardiographic LVH was present in 33% of 379 hypertensive patients. AF progression after 1 year occurred in 10.2% of 373 patients with rhythm follow-up. In hypertensive patients with LVH, AF progression occurred more frequently as compared with hypertensive patients without LVH (23.3% vs 8.8%, p = 0.011). In hypertensive AF patients, LVH was the most important multivariably adjusted determinant of AF progression on multivariable logistic regression (odds ratio 4.84, 95% confidence interval 1.70 to 13.78, p = 0.003). This effect was only seen in male patients (27.5% vs 5.8%, p = 0.002), while in female hypertensive patients, no differences were found in AF progression rates regarding the presence or absence of LVH (15.2% vs 15.0%, p = 0.999). No differences were seen in MACCE for hypertensive patients with and without LVH. In conclusion, in men with hypertension, LVH is associated with AF progression. This association seems to be absent in hypertensive women

Progression From Paroxysmal to Persistent Atrial Fibrillation. Clinical Correlates and Prognosis

Objectives: We investigated clinical correlates of atrial fibrillation (AF) progression and evaluated the prognosis of patients demonstrating AF progression in a large population. Background: Progression of paroxysmal AF to more sustained forms is frequently seen. However, not all patients will progress to persistent AF. Methods: We included 1,219 patients with paroxysmal AF who participated in the Euro Heart Survey on AF and had a known rhythm status at follow-up. Patients who experienced AF progression after 1 year of follow-up were identified. Results: Progression of AF occurred in 178 (15%) patients. Multivariate analysis showed that heart failure, age, previous transient ischemic attack or stroke, chronic obstructive pulmonary disease, and hypertension were the only independent predictors of AF progression. Using the regression coefficient as a benchmark, we calculated the HATCH score. Nearly 50% of the patients with a HATCH score >5 progressed to persistent AF compared with only 6% of the patients with a HATCH score of 0. During follow-up, patients with AF progression were more often admitted to the hospital and had more major adverse cardiovascular events. Conclusions: A substantial number of patients progress to sustained AF within 1 year. The clinical outcome of these patients regarding hospital admissions and major adverse cardiovascular events was worse compared with patients demonstrating no AF progression. Factors known to cause atrial structural remodeling (age and underlying heart disease) were independent predictors of AF progression. The HATCH score may help to identify patients who are likely to progress to sustained forms of AF in the near future. \ua9 2010 American College of Cardiology Foundation