Search

Non-Markovian dynamics of a charged particle in a two-dimensional harmonic oscillator linearly coupled to a neutral bosonic heat bath is investigated in an external uniform magnetic field and two perpendicular time-dependent electric fields. The analytical expressions for the time-dependent and asymptotic angular momentum are derived for the Markovian and non-Markovian dynamics. The dependence of the angular momentum on the frequency of the electric field, cyclotron frequency, collective frequency, and anisotropy of the heat bath is studied. The angular momentum (or magnetization) of a charged particle can be ruled by varying the frequency of the electric field.

The non-Markovian dynamics of a charged particle confined in the harmonic oscillator and linearly coupled to a neutral bosonic heat bath is investigated in the external uniform magnetic field. The analytical expressions are derived for the time-dependent and asymptotic orbital angular momenta. The transition from non-Markovian dynamics to Markovian dynamics and the transition from a confined charge particle to a free charge particle are considered. The orbital diamagnetism of graphene in a dissipative environment and an external uniform magnetic field is studied and compared with existing experimental data. The results are presented for the electric conductivity and resonance behavior of the mass magnetization in graphene.

The time evolution of an occupation number is studied for a fermionic or bosonic oscillator linearly fully coupled to several fermionic and bosonic heat baths. The influence of the characteristics of thermal reservoirs of different statistics on the nonstationary population probability is analyzed at large times. Applications of the absence of equilibrium in such systems for creating a dynamic (nonstationary) memory storage are discussed.

For the fermionic or bosonic oscillator fully coupled to several heat baths with mixed statistics, the analytical expressions for the occupation numbers are derived within the non-Markovian quantum Langevin approach. Employing two or three heat baths and the Ohmic dissipation with Lorenzian cutoffs, the role of statistics of the system and heat baths in the dynamics of the system is studied.

Employing the fermionic and bosonic Hamiltonians for the collective oscillator linearly FC-coupled with several heat baths, the analytical expressions for the collective occupation number are derived within the non-Markovian quantum Langevin approach. The master equations for the occupation number of collective subsystem are derived and discussed. In the case of Ohmic dissipation with Lorenzian cutoffs, the possibility of reduction of the system with several heat baths to the system with one heat bath is analytically demonstrated. For the fermionic and bosonic systems, a comparative analysis is performed between the collective subsystem coupled to two heat baths and the reference case of the subsystem coupled to one bath.

The spectral, dissipative, and statistical properties of the damped quantum oscillator are studied in the case of non-Markovian and nonstationary system-heat bath coupling. The dissipation of collective energy is shown to be slowed down, and the decoherence rate and entropy grow with modulation frequency., (©2011 American Physical Society)

The influence of an external magnetic field on the non-Markovian dynamics of an open two-dimensional quantum system is investigated. The fluctuations of collective coordinate and momentum and transport coefficients are studied for a charged harmonic oscillator linearly coupled to a neutral bosonic heat bath. It is shown that the dissipation of collective energy slows down with increasing strength of the external magnetic field. The role of magnetic field in the diffusion processes is illustrated by several examples.

The analytical expressions for the time-dependent friction and diffusion coefficients are presented for the case of coupling in coordinates between the collective subsystem and a squeezed heat bath. The effects of initial phase-sensitive and -insensitive correlations of the heat bath on the diffusion coefficients, fluctuations, and decoherence are studied. The interplay between friction and decoherence is discussed.

Changes in the antral gastric mucosa of patients with doudenal ulcer after a long-term administration of antisecretory agents were studied. The subjects were five patients with a different duration of the disease. The methods applied included light and electron microscopy of tissue samplings taken from the antral part of the stomach during the periods of exacerbation and remission. In addition to well-known morphological changes, cellular principalis not typical of antral gastric mucosa were found in one patient during exacerbation and remission periods.

Generalized Langevin equations and fluctuation-dissipation relations are derived for the case of a nonlinear non-Markovian noise. The explicit expressions for the time-dependent friction and diffusion coefficients are presented for the case of general and linear couplings in the coordinate and momentum between the collective harmonic oscillator and heat bath. The long-time tails of correlation functions are investigated in the low- and high-temperature regimes of dissipation for different couplings. The Onsager's regression hypothesis is discussed for the non-Markovian dynamics. The Lindblad theory is justified on the basis of the microscopical model.

On the basis of a master equation for the reduced density matrix of open quantum systems, we study the influence of time-dependent friction and diffusion coefficients on the decay rate from a potential well and the capture probability into a potential well. Taking into account the mixed diffusion coefficient Dqp, the quasistationary decay rates are compared with the analytically derived Kramers-type formulas for different temperatures and frictions. The diffusion coefficients supplying the purity of states are derived for a non-Markovian dynamics.

Surface relief and configuration of peripheral blood erythrocytes were studied under a scanning electron microscope in 42 patients with paranoid schizophrenia during the active phase and remission. Control group consisted of 30 mentally and somatically healthy donors. The count of functionally intact biconcave discocytes was appreciably (p < 0.001) decreased and the incidence of transitory, prehemolytical, and degenerative forms of erythrocytes increased in the patients. Morphological restructuring of the erythrocyte population was universal in the patients with different duration of the schizophrenic process.

A thorough clinical analysis of pains in the right hypochondrium was carried out in 880 patients. There were 80 men (the mean age 45 years) and 800 women (the mean age 40 years). Three groups of the symptom complexes were distinguished, pointing to: (a) dyskinesia of the gallbladder by the hypotonic type; (b) dyskinesia of the gallbladder by the hypertonic type; (c) chronic cholecystitis. Ultrasonography of the abdominal organs in 55 persons, primarily in the third group patients revealed calculous cholecystitis which accounted for 6. 25% of the total number of the examinees. All the patients suffering from chronic calculous cholecystitis received cholecystectomy on an elective basis. It should be mentioned that preoperative examination and treatment of concomitant diseases were done on an outpatient basis, which permitted the patients' stay at the hospital to be reduced more than two-fold (to 15 days). The data obtained allowed a conclusion about the necessity of a wider use of ultrasonography of the gallbladder as a screening method to examine outpatients with pains in the right hypochondrium and of carrying out an all-round examination and treatment of concomitant diseases in patients suffering from chronic calculous cholecystitis at the prehospital stage.

Analysis was made of records available in the disease histories of 270 patients who had referred to the district internist for pains in the epigastrium and right hypochondrium. In these patients, endoscopy of the upper alimentary tract revealed the indirect signs of the impairment of the choledochopancreatic organs without gross pathology of the gastric or duodenal mucosa. Endoscopy was performed during the first week after the patient had referred to the district internist. It is shown that despite the fact that the endoscopy-performing physician had discovered the indirect signs of biliary diseases, the district internist did not make any attempts at expanding the scope of examinations in order to find out the main cause of pains sensed by the patient in the epigastrium or in the right hypochondrium. This can be accounted for by the fact that the district internists fall short of the skills of a proper interpretation of the data available in the protocol of an endoscopic examination as well as of the desire to adhere to the times of temporary disability in different disease entities, indicated in the methodological instructions. It is concluded that in the course of the training of the district internists, special attention should be paid to a proper interpretation of the paraclinical data and to the design of the program of the diagnostic search.

The role of antidiuretic hormone in the organism ability to resist against considerable salt shifts, was studied in Wistar (1st group) and Brattleboro rats--heterozygotes (2nd group). 5% NaCl solution was infused into animals' stomach (30-50-70-100 ml/kg). An increase in diuresis especially at 7-10% load, and a decrease in Na and K excretion occurred in Brattleboro rats. A decrease in tissue cation accumulation was found in Brattleboro rats as compared to Wistar ones. The Brattleboro rats with a partial defect of ADH synthesis revealed a decrease in the reserve possibilities of the system regulating the water-salt metabolism. As a result, 100% of Brattleboro rats died after 100 ml/kg salt load whereas the mortality in Wistar rats was only 22.2%.

The mechanism of integration of osmo- and volume-regulating systems after intake of 3, 5, 7, and 10% of body weight water, salt, and volume loads, was studied in adult rats. The changes of diuretic and ionuretic renal functions depended on the character and quantity of shifts caused in organism. The volume shift is the starting mechanism for stabilization of disturbed balance while the osmotic factor secures the final regulation of watersalt homeostasis.

The state of pulmonary hemodynamics and the contractile function of the right parts of the heart were studied clinically and instrumentally in 35 patients with diffuse chronic pathological conditions of the liver. The lungs and heart were examined morphologically in 24 persons who had died from cirrhosis of the liver in the edematous-ascitic stage. Pulmonary hypertension was found to be directly dependent on the degree of the diffuse affection of the liver. Secondary-compensatory changes in the contractile function of the myocardium of the right parts of the heart in response to increase of pressure in the pulmonary artery in patients with cirrhosis of the liver were proved to occur.