Low-temperature kinetics of exciton-exciton annihilation of weakly localized one-dimensional Frenkel excitons

We present results of numerical simulations of the kinetics of exciton-exciton annihilation of weakly localized one-dimensional Frenkel excitons at low temperatures. We find that the kinetics is represented by two well-distinguished components: a fast short-time decay and a very slow long-time tail. The former arises from excitons that initially reside in states belonging to the same localization segment of the chain, while the slow component is caused by excitons created on different localization segments. We show that the usual bi-molecular theory fails in the description of the behavior found. We also present a qualitative analytical explanation of the non-exponential behavior observed in both the short- and the long-time decay components.Comment: Published in J. Chem. Phys. 114, 1 April (2001

Nonlinear resonance reflection from and transmission through a dense glassy system built up of oriented linear Frenkel chains: two-level models

A theoretical study of the resonance optical response of assemblies of oriented short (as compared to an optical wavelength) linear Frenkel chains is carried out using a two-level model. We show that both transmittivity and reflectivity of the film may behave in a bistable fashion and analyze how the effects found depend on the film thickness and on the inhomogeneous width of the exciton optical transition.Comment: 26 pages, 9 figure

Quality and safety problems of sports nutrition products

The purpose of this work was to study the quality and safety of some sports nutrition products. The objects of study were sports nutrition products: protein bars of ‘ProteinBar’ (Russia) and ‘Bombbar’ (Russia); capsule forms of dietary supplements ω–3, ω–6, ω–9 firms ‘Sportline’ (Russia), ‘Multipower’ (Germany) and ‘Maxler’ (USA). According to the research results, the normalized safety indicators of the fat component of the studied products for sports nutrition (acid number and peroxide) are within acceptable values. The standardized safety indicators of the fat component do not fully reflect the safety requirements for the fat component of sports nutrition products, since there are no standards for the most important indicators of fat safety – the content of secondary oxidation products – copolymers insoluble in petroleum ether and epoxides. The results obtained in the course of the work showed that in almost all of the studied samples are content of epoxides (7.5–47.6 g -1 ) and secondary oxidation products – 1% or more

Intensive Care Outcomes and Differences Between Survivors and Deceased Patients in a Terminal Coma: A Retrospective Observational Study

Background. Early prognosis for the outcome of a coma-induced critical condition is central to selecting an optimal tactic for patient management. This question remains insufficiently studied, thus justifying the task of identifying significant criteria for differences in terminal coma patients (stage III, irreversible) who died and those recovered to different levels of consciousness.Objectives. To analyze the intensive care outcomes for patients in a terminal coma and to establish differences between the initial state of patients who have died and those who have recovered to different levels of consciousness.Methods. A retrospective observational study was conducted on 210 patients aged 21 to 65 hospitalized in the Anesthesiology and Resuscitation Unit of Ochapovsky Regional Clinical Hospital No. 1 (Krasnodarsky Krai) with a diagnosis of terminal coma in the period from 2010 to 2015. The study did not include patients with pregnancy, histologically-confirmed malignancies, cardiovascular diseases (NYHA classes III-IV, according to the New York Heart Association Functional Classification), terminal liver cirrhosis and chronic kidney disease at the stage of hemodialysis. Depending on the critical condition outcome, the admitted patients were divided into groups: group 1 (n = 101) — patients with adverse outcomes; group 2 (n = 109) — patients with relatively favorable outcomes (recovery to a level of consciousness at score 4 and higher, according to The Glasgow Coma Scale). The condition was assessed with referring to available clinical data. Statistical processing of the obtained study results was carried out via nonparametric techniques using Microsoft Excel 10 (Microsoft, USA) and Statistica 6.0 (StatSoft, USA).Results. The mortality structure against the background of a terminal coma in the following diagnosis: polytrauma — 54%, hemorrhagic stroke — 56%, isolated traumatic brain injury — 37%, acute cerebrovascular accidents (ischemic type) — 33% and acute posthypoxic dyscirculatory encephalopathy — 11%. Intergroup differences between the deceased and survivors were obtained in the following parameters: age (older with unfavorable outcome); base deficit — by 52%; glucose — by 47.6%; troponin — by 47.1%; potassium — by 13.7% and daily diuresis — by 27.5%.Conclusion. The obtained results are likely to be used in a combination of clinical, instrumental and laboratory examinations in order to provide early detection of the risk group with an adverse outcome

Superradiance from an ultrathin film of three-level V-type atoms: Interplay between splitting, quantum coherence and local-field effects

We carry out a theoretical study of the collective spontaneous emission (superradiance) from an ultrathin film comprised of three-level atoms with $V$-configuration of the operating transitions. As the thickness of the system is small compared to the emission wavelength inside the film, the local-field correction to the averaged Maxwell field is relevant. We show that the interplay between the low-frequency quantum coherence within the subspace of the upper doublet states and the local-field correction may drastically affect the branching ratio of the operating transitions. This effect may be used for controlling the emission process by varying the doublet splitting and the amount of low-frequency coherence.Comment: 15 pages, 5 figure

Non-Linear Algebra and Bogolubov's Recursion

Numerous examples are given of application of Bogolubov's forest formula to iterative solutions of various non-linear equations: one and the same formula describes everything, from ordinary quadratic equation to renormalization in quantum field theory.Comment: LaTex, 21 page

THE RESULTS OF THE STUDY OF VARIETIES OF ALFALFA IN THE CENTRAL-CHERNOZEM ZONE

Three-year study of one hundred world collection of alfalfa was conducted in Central Black-Earth zone of Russia. The varieties of Medicago × varia ‘Zheltogibridnaya 99’, ‘Flora 2’, ‘Karlygash’ and ‘№ 152’ (hybrid ‘Severnaya hybridnaya’ בAugune II’) were recommended for breeding programs. The most variable were character of seed production, productivity of green mass and hay yield productivity; character of foliage and the intensity of regrowth of plants on the 20-th day after spring regrowth had medium variability. The height before the first mowing and height in the phase of full flowering had low variability. There was a significant correlation between the yield of green mass and hay, the yield of green mass and intensity of regrowth and a weak negative correlation between the yield of green mass and seed yield

Postoperative delirium in elderly patients after thoracic surgery

Background. Postoperative delirium is one of the most severe and common complications of thoracic surgery in elderly patients.Objective. To establish a simple and accurate method for predicting the development of postoperative delirium in patients after thoracic surgery.Material and Methods. We performed an observational cohort study of 303 patients who underwent lobectomy for oncological diseases. The nature of anesthesia and surgical intervention, features of the volume status and hemodynamic changes during the perioperative period were analyzed, laboratory indicators of this period were evaluated.Results. Of 303 patients, 43 (14.2%) developed postoperative delirium. Non-modifiable factors for the development of postoperative delirium included age, history of cerebrovascular accident, alcohol misuse disorder, chronic heart failure, more severe physical status according to the ASA (American Society of Anesthesiologists) Physical Status Classification System. Modifiable factors are the following: the duration of one-lung ventilation, episodes of perioperative hypotension and hypoxemia, the use of opioids, the intensity of the pain syndrome in the postoperative period, and reduced oxygen transport function of the blood. A number of laboratory parameters (blood albumin, blood glucose, leukocytosis), reflecting the degree of surgical stress, may also be useful in postoperative delirium predicting.Conclusion. A prognostic coefficient was compiled with a concordance of 99.9 and Somers' D 0.998. It is equal to the sum of the products: (–3.5367) multiplied by pain intensity on a 10 cm Visual Analogue Scale an hour after surgery; 2.2037 multiplied by the blood albumin level the morning after surgery;    (–4.8151) multiplied by the blood glucose level the morning after surgery