32 research outputs found
General features of Bianchi-I cosmological models in Lovelock gravity
We derived equations of motion corresponding to Bianchi-I cosmological models
in the Lovelock gravity. Equations derived in the general case, without any
specific ansatz for any number of spatial dimensions and any order of the
Lovelock correction. We also analyzed the equations of motion solely taking
into account the highest-order correction and described the drastic difference
between the cases with odd and even numbers of spatial dimensions. For
power-law ansatz we derived conditions for Kasner and generalized Milne regimes
for the model considered. Finally, we discuss the possible influence of matter
in the form of perfect fluid on the solutions obtained.Comment: extended version of published Brief Repor
The nature of singularity in multidimensional anisotropic Gauss-Bonnet cosmology with a perfect fluid
We investigate dynamics of (4+1) and (5+1) dimensional flat anisotropic
Universe filled by a perfect fluid in the Gauss-Bonnet gravity. An analytical
solutions valid for particular values of the equation of state parameter
have been found. For other values of structure of cosmological
singularity have been studied numerically. We found that for the
singularity is isotropic. Several important differences between (4+1) and (5+1)
dimensional cases are discussed.Comment: 8 pages, 2 fig
New properties of scalar field dynamics in brane isotropic cosmological models
Several aspects of scalar field dynamics on a brane which differs from
corresponding regimes in the standard cosmology are investigated. We consider
asymptotic solution near a singularity, condition for inflation and bounces and
some detail of chaotic behavior in the brane model. Each results are compared
with those known in the standard cosmology.Comment: 13 pages with 2 eps figures, submitted to Astronomy Letter
The generality of inflation in closed cosmological models with some quintessence potentials
We have investigated the generality of inflation (the probability of
inflation in other words) in closed FRW models for a wide class of quintessence
potentials. It is shown that inflation is not suppressed for most of them and
for a wide enough range of their parameters. It allows us to decide inflation
is common enough even in the case of closed Universe.Comment: 7 pages, 6 eps figures, to appear in PR
corrections to the cosmological dynamics of inflation in the Palatini formulation
We investigate the corrections to the inflationary cosmological dynamics due
to a term in the Palatini formulation which may arise as quantum
corrections to the effective Lagrangian in early universe. We found that the
standard Friedmann equation will not be changed when the scalar field is in the
potential energy dominated era. However, in the kinetic energy dominated era,
the standard Friedmann equation will be modified and in the case of closed and
flat universe, the Modified Friedmann equation will automatically require that
the initial kinetic energy density of the scalar field must be in sub-Planckian
scale.Comment: 11 pages, no figures. Accepted by Class.Quant.Grav.v2:References
adde
Stable exponential cosmological solutions with zero variation of G in the Einstein–Gauss–Bonnet model with a Λ -term
Nonminimal Inflation and the Running Spectral Index
We study a class of models in which the inflaton is minimally coupled to
gravity with a term f(R)\vp^2. We focus in particular on the case when , the expansion of the scale factor is driven by the usual potential
energy, while the rolling of the inflaton is driven by the nonminial coupling.
We show that the power spectrum is in general blue, and the problem of getting
a running spectral index is eased. However, the inflaton potential must have a
large second derivative in order to get a large running.Comment: 9 pages, harvma
Комплаентность и персистентность у пациентов с первичной открытоугольной глаукомой с позиции офтальмолога
PURPOSE: Determination of key factors of non-compliance for treatment and duration of recommendations accomplishment in accordance with doctor’s instructions and associated with time from therapy start to its discontinuation (persistence) in patients with glaucoma by assessment of personal opinion of ophthalmologists with different amount of experience.METHODS: 509 queries of medical professionals (631 doctors) from Russia and other 6 countries were included into the study. All doctors’ queries were grouped according to the duration of their work experience, place of work — depending on medical care type (ambulatory or inpatient) and by hospital propriety type (state or private). Data collection method: online survey. The significance of the 32 selected compliance factors was assessed by the ball system from 10 (maximum significant factor) to 1 (minimally significant factor). Analysis program Statistica 8.0 (StatSoft Inc., USA).RESULTS: Data analysis allowed determining medium terms for continued application of recommended therapy depending on patients group. Persistency of low-compliant patients was considered a period of continued following of recommendations from 15 up to 27.5 days per year, high-compliant — 180-300 days per year. Doctors’ opinion depended on time in professional and place of work. Study results allowed recognizing percent’s of “low-compliant”, “mediumcompliant” and “high-compliant” patients. Following patients compliance factors were assessed as well: factors directly associated with treatment, factors, associated with patient’s condition, factors of behavioral compliance and social compliance. Moreover, trial results displayed difference in opinion of medical specialists depending on the duration of their work experience, place of work and clinic type.CONCLUSION: Study groups divided by the amount of healthcare experience showed no difference in patients compliance apprehension. Percentage of low-compliant patients was 20 [10; 30] %; medium-compliant — 30 [20; 45] and high-compliant — 50 [30; 60]% in all groups. A longer duration of healthcare experience corresponded with higher persistence requirements. Low-compliant patients followed recommendations for up to 20 days per year [7; 60]; medium-compliant — for 90 [20; 200] and lowcompliant — 200 [40; 350]. Primary factors for non-compliancy in all groups were defined as follows: absence of motivation; complicated instillation regimen influencing daily activities; absence of contact with attending physician; low information level concerning condition; age; side effects; medication price; laziness; family history of glaucoma. Factors of behavioral compliance were considered the most important in all groups — 75%.ЦЕЛЬ. Определение ключевых факторов нарушения приверженности к лечению (комплаентности) и продолжительности в выполнении назначений по времени от начала терапии до ее прекращения (персистентности) у пациентов с глаукомой при изучении субъективного мнения врачей-офтальмологов с разным стажем и местом работы.МЕТОДЫ. В исследование были включены 509 анкет от 631 врача из России и 6 стран СНГ. Все анкеты врачей были разделены на группы в зависимости от их стажа и места работы, вида собственности лечебно-профилактического учреждения (государственной или частной) и формы оказания медицинской помощи (амбулаторной или стационарной). Метод сбора данных: онлайн-анкетирование. Значимость 32 отобранных факторов комплаентности оценивалась по балльной системе от 10 (максимально значимого фактора) до 1 (минимально значимого фактора). Программа анализа: Statistica 8.0 (StatSoft Inc., США).РЕЗУЛЬТАТЫ. Анализ данных позволил получить средние сроки непрерывного соблюдения назначенной терапии в зависимости от принадлежности участников анкетирования к той или иной группе. Персистентность (период непрерывного соблюдения рекомендаций) низкокомплаентных пациентов составила от 15 до 27,5 дней в году, высококомплаентных — от 180 до 300 дней в году. Мнение врачей зависело от стажа и места их работы. Выявлены доли «низкокомплаентных», «среднекомплаентных» и «высококомплаентных» пациентов. Проанализированы конкретные факторы приверженности пациентов к соблюдению рекомендаций, связанные непосредственно с лечением, состоянием пациента, особенности поведенческой и социальной комплаентности. Результаты исследования показали различия мнений практикующих врачей в зависимости от стажа, места работы и вида лечебного учреждения.ЗАКЛЮЧЕНИЕ. В анализируемых группах врачей, разделенных по стажу работы, разница в представлениях о комплаентности пациентов не выявлена. Доля «низкокомплаентных» пациентов составляет в среднем 20% [10; 30], «среднекомплаентных» — 30% [20; 45] и «высококомплаентных» — 50% [30; 60]. Чем больше стаж, тем более высокие требования предъявляются врачами к соблюдению рекомендаций. Предполагается, что «низкокомплаентные» пациенты соблюдают рекомендации в течение 20 [7; 60] дней в году, «среднекомплаентные» — 90 [20; 200], «высококомплаентные» — 200 [40; 350]. Ведущими факторами нарушения комплаентности во всех группах являются: отсутствие мотивации, сложный режим инстилляций, отсутствие контакта с врачом, низкая степень информированности о заболевании, возраст, забывчивость, наличие побочных эффектов, стоимость, лень, семейный анамнез глаукомы. На первом месте во всех группах отмечают факторы поведенческой комплаентности — до 75%
COMPARATIVE ANALYSIS OF THE DYNAMICS OF IMMUNE-ANTIOXIDANT STATUS OF THE ANTIOXIDANT SYSTEM IN PATIENTS SUFFERING FROM HYPOTHYROIDISM AND COPD
Aim. To carry out a comparative study of the features and shift tendency of individual indicators of the antioxidant system in patients with hypothyroidism and COPD of various phenotypes. 79 patients suffering from COPD III and IV were examined at the age of 60 to 80 years (men and women) who were hospitalized in the pulmonology department of the Regional Clinical Hospital No. 2 in Krasnodar, along with 47 patients suffering from hypothyroidism.Materials and methods. The state of the blood antioxidant system was assessed by the activity of erythrocyte catalase and superoxide dismutase, the level of reduced thiol groups of erythrocytes, and the amperometric index of the total antioxidant activity of blood plasma. The activity of catalase was studied in the hemolysate of erythrocytes according to the method of Beers R.Results. It was established that there were significant changes in the functioning of individual links of the antioxidant protection system in patients with COPD and hypothyroidism, as well as the stress in the system in general. At the same time, enzyme activity of the antioxidant system of erythrocytes varies in multidirectional ways, whereas the indices of the cellular and extracellular non-enzyme links of the endogenous antioxidant system change in a unidirectional way towards the decrease, which may indicate a significant activation of free radical oxidation processes and partial depletion of the low-molecular antioxidant blood link.Conclusion. The revealed imbalance in the pro-/antioxidant system requires the introduction of drugs with antioxidant activity into therapeutic regimens. In patients with COPD, hypoxia and chronic inflammation may provoke oxidative stress, while in patients with hypothyroidism –decrease in the level of basal metabolism and anabolic processes in general