The impact of electron correlations on the energetics and stability of silicon nanoclusters.

The first-principles prediction of stable nanocluster structure is often hampered by the existence of many isomer configurations with energies close to the ground state. This fact attaches additional importance to many-electron effects beyond density functional theory (DFT), because their contributions can change a subtle energy order of competitive structures. To analyze this problem, we consider, as an example, the energetics of silicon nanoclusters passivated by hydrogen Si10H2n (0 ≤ n ≤ 11), where passivation changes the structure from compact to loosely packed and branched. Our calculations performed with DFT, hybrid functionals, and Hartree-Fock methods, as well as by the GW approximation, confirm a considerable sensitivity of isomer energy ordering to many-electron effects.

[Problems of Diagnosis and Treatment of Pulmonary Hypertension in Old Patients With Chronic Obstructive Pulmonary Disease].

The article contains consideration of risk factors of pulmonary hypertension (PH), clinical states associated with PH, and effect of age on susceptibility to PH in patients with chronic obstructive pulmonary disease (COPD). We have analyzed the prevalence of PH associated with COPD, its importance in the structure of diseases in patients of older age groups. Frequency of PH in old patients is associated with prevalence of concomitant diseases. Addition of LH to polymorbid complex of old age worsens quality of life and increases mortality. We also present in this article data on the use of modern drugs for the treatment of LH in COPD patients aged 60 years and older.

[Possible side effects of drugs in elderly patients with chronic obstructive pulmonary disease and comorbidity].

the papers gives data on the positive effects and adverse reactions of drugs used to treat chronic obstructive pulmonary disease (COPD) and its comorbidity, first of all cardiovascular disease. The authors present alternative points of views based on both the data available in the literature and their findings. they propose to modify pharmacotherapy for COPD in the presence of comorbidity in patients of old age groups.

[Adrenalectomy changes diazepam performance in male and female rats under multiparametric test conditions].

It is established that adrenalectomy decreases the "sedative" and "anti-anxiety" effects and reduces the "anxiogenic" effect of diazepam in male rats under multiparametric test conditions. At the same time, the "sedative" and "activating" effects of this tranquilizer do not appear in adrenalectomized female rats and the "anti-anxiety" effect is only observed in the evening. The "anxiogenic" effect of diazepam in females is not observed for a drug dose of 0.5 mg/kg and is only manifested at a dose of 0.1 mg/kg.

[Microflora of palatine tonsils in chronic tonsillitis].

The objective of the present work was to develop the standardized approaches to pharmacotherapy of chronic tonsillitis based on the data of regional specificity of the tonsillar microflora. The methods of investigations included the study of throat swabs obtained from 668 patients presenting with various forms of chronic tonsillitis (CT). Half of these patients were shown to be infected with Streptococcus pyogenes and 24.5% with Mycoplasma pneumoniae. The presence of concomitant pathology of the respiratory and digestive tracts in the patients with CT increases the probability of identification of enterobacteria, enteroccocci, and staphylococci in combination with streptococci and mycoplasmas. It is concluded that the choice of antibacterial therapy should be based on the results of analysis of the aggravated medical history and bacteriological diagnostics including the isolation of all putative pathogens and examination of their susceptinility to antibacterial agents.

[Stress effect on haloperidol-induced catalepsy and its circadian rhythm in intact and ovariectomized female rats].

Stressing reduces the intensity of haloperidol-induced catalepsy in intact female rats and increases it in ovariectomized animals. Ovarioectomy reduces the severity of haloperidol catalepsy. Circadian rhythm acrophase of the cataleptogenic haloperidol activity in female rats after ovariectomy and stress exhibits significant displacement.

Precision measurement of the neutral pion lifetime.

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π0 into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π0 photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

Method for Simultaneous Prediction of Atomic Structure and Stability of Nanoclusters in a Wide Area of Compositions.

We present a universal method for the large-scale prediction of the atomic structure of clusters. Our algorithm performs the joint evolutionary search for all clusters in a given area of the compositional space and takes advantage of structural similarities frequently observed in clusters of close compositions. The resulting speedup is up to 50 times compared to current methods. This enables first-principles studies of multicomponent clusters with full coverage of a wide range of compositions. As an example, we report an unprecedented first-principles global optimization of 315 Si nO m clusters with n ≤ 15 and m ≤ 20. The obtained map of Si-O cluster stability shows the existence of both expected (SiO2) n and unexpected (e.g., Si4O18) stable (magic) clusters, which can be important for a variety of applications.

[Sexual distinctions of the diazepam activity in rats in the conflict situation].

Diazepam caused less pronounced shifts in the conflict situation test in female rats as compared to males. The drug produced more pronounced anticonflict action on male rats in the evening. In female rats, a doze of 0.5 mg/kg of the anxiolytic drug produced a clear anticonflict action, mostly in the evening; however, even this effect was approximately only about half of that observed in males in the same period of time.

Regional specifics of microbial landscape in outpatients with lower respiratory tract infections.

BACKGROUND: The last years have witnessed progressive growth of antimicrobial resistance (AMR) both in hospital-acquired and community-acquired respiratory infections. Regional guidelines (2006) presented standard approaches to pharmacotherapy and provided an important contribution to improvement of antimicrobial therapy at healthcare facilities of both the City of Stavropol and the Stavropol Region. At the same time, recent years have witnessed substantial changes in sensitivity to antimicrobials; besides, newer antibiotics have become available now. This substantiates the need for update of the regional guidelines [1]. OBJECTIVE: To determine the issues related to standardization of antibiotic therapy of lower respiratory tract (LRT) infections at an outpatient setting; to assess regional changes (2007-2012) in the spectrum of pathogens causing LRT diseases in patients of the regional healthcare facilities in view of their age and the diagnosis as compared with the years of 2003-2006. METHODS: In 2007-2012, we examined sputum microbiology of patients with LRT infections at the bacteriological laboratory of the Centre for Clinical Pharmacology and Pharmacotherapy (Stavropol, Russia), following the methodology guidelines [2]. The comparison was carried out with the results of the microbiological examination of 7051 sputum samples (held in 2003-2006). Statistical analysis was carried out using arithmetic means, standard errors, and Student's t test involving a software package STATISTICA 6.0. RESULTS: In the outpatient practice, half of the patients with LRT infections were identified to have Str. Pneumoniae. The sputum of every fifth examined patient allowed isolating Enterobacteriaceae family members such as Klebsiella spp. (Klebsiella pneumoniae in most cases), Serratiaspp., E. coli, and Enterobacter spp. It is essential to note that almost a quarter of the patients were found to have M. pneumoniae. C. Pneumonia was detected quite often as well (19%). Str. pneumoniae, M. pneumoniae, and C. pneumoniae were found in virtually 80% of all the cases of community-acquired pneumonia in adults. H. influenzae and M. pneumoniae were 2-3 times more often isolated from the sputum of patients with chronic obstructive pulmonary disease (COPD) and chronic non-obstructive bronchitis.Along with an increase in the patients' age, regardless of the diagnosis, the proportion of pneumococci, Haemophilus influenzae and various members of the Enterobacteriaceae family went up, while the share of mycoplasmas went down. However, even in patients over 60 years of age M. pneumoniae accounted for a significant share in the overall spectrum of pathogens, which indicates the need for microbiological monitoring, especially as far as COPD is concerned.In contrast to the previous years, only 35% of the patients (previously 60%) underwent bacteriological examination (p<0.05) while receiving antibiotic therapy. Significant prevalence of mycoplasmas in the structure of the isolated microorganisms was found in patients who had been previously treated with ß-lactam antibiotics.Associations of pathogens were detected in 14% of cases, which is half the rate found 2-3 years ago. The associations were found to reveal more frequent presence of H. influenzae in patients with acute exacerbation of chronic non-obstructive bronchitis, and Enterobacteriaceae - in patients with COPD and pneumonia. The recent years have shown that, combined with other microorganisms, there can be detected pneumococci (p<0.05), H. influenzae, as well M. pneumoniae, while there have been fewer cases of enterococci and enterobacteria; as for non-filterable bacteria, they have been never detected again (p<0.05).Strains of H. influenzae maintained high sensitivity to aminopenicillins, including the protected ones. The antibiotic resistance possessed by Str. pneumoniae to aminopenicillins doubled (12.4% strains vs. 6.4% 3 years ago, p<0.05). The resistance to Co-trimoxazole and Ofloxacin was 27.9% and to macrolides it was 17.9%. Various representatives of the Enterobacteriaceae family maintained high sensitivity to aminopenicillins, second and third generation cephalosporins, fluoroquinolones.Of the 20 M. pneumoniae strains that were tested, 8 (40%) displayed resistance to one or more antimicrobials. The highest numbers of cases with resistance were detected to Ciprofloxacin (25%) and Erythromycin (20%). 10% strains of mycoplasma showed resistance to Doxycycline and Ofloxacin, while only 5% of mycoplasmas were identified as having non-sensitivity to Clarithromycin and Azithromycin. CONCLUSIONS: The results of the research carried out in the recent years in comparison with the data of the previous years, call for reviewing of the standard approaches to the choice of antimicrobial agents in respiratory tract infections. In order to improve the standard of care, the choice of medicines should be based on a number of factors, namely the age, the severity of the respective pathological condition, previous antimicrobial use, and the level of care.

Effect of haloperidol and chlorpromazine on reversal learning of normal and striatectomized rats in a Y-maze.

Haloperidol (0.05-0.1 mg/kg) and chlorpromazine (0.5-1.0 mg/kg) improved reversal learning avoidance responses in a Y-maze, decreased intersessional fluctuations of errors and decreased the number of spontaneous exits from a correctly selected chamber. After bilateral lesions of the striatum this effect disappeared. Brain lesions also attenuated the ability of neuroleptics to suppress amphetamine-induced stereotypy and and accompanying defects in avoidance responses. The improvement of avoidance behavior by neuroleptics may be related to the reduction of spatial preference caused by functional asymmetry between the bilateral nigro-striatal systems.

Radioecological impacts of the Techa River contamination.

During the years 1949-1952, the Mayak Production Association (MAYAK), which was processing weapons-grade plutonium, was discharging radioactive wastes into the Techa River. As a result, all components of the river system (water, bottom soils, and flood plains) were exposed to massive radioactive contamination. The protective measures taken in the 1950's resulted in the improvement of the radioecological conditions in the Techa River. After 1952, the radioecological conditions in the area were mostly determined by the long-lived radionuclides 9OSr and 137Cs. This article focuses on the dependencies governing the migration of radionuclides along the vertical and horizontal planes in different components of the river system over a 40-y period. Until the 1990's, a decrease in 90Sr and 137Cs contents was noted in environmental samples and foodstuffs produced in riverside villages. In the subsequent years, the radioecological situation on the Techa stabilized. The sources of the current contamination of the river are represented by the runoffs from by-pass canals and swampy upper reaches.

The effects of lesions to the striatum on the function of the hypothalamo-hypophyseal-adrenal system in adrenalectomized rats.

Experiments on white rats were performed to study the effects of bilateral lesioning of the striatum on activation of the hypothalamo-hypophyseal-adrenal system (HHAS) after unilateral adrenalectomy. These studies showed that increases in the weight of the surviving adrenal gland were smaller in striatectomized rats than in controls. There was a significant decrease in corticosteroid production by the intact gland. These changes were most marked after destruction of the dorsal parts of the nucleus. These data provide evidence for involvement of the striatum in controlling HHAS activity via a feedback mechanism.

Influence of pineal peptides on the dynamics of the circadian and minute motor biorhythms in rats.

A peptide preparation of the pineal, epithalamin, when administered chronically, exerts a modulating influence on the diurnal fluctuations of the motoric activity of rats. It also decreases the amplitude of apomorphine stereotypy and induces a restructuring of a modulatory character in its rhythmic structure. It is hypothesized that the pineal peptides participate in the maintenance of homeostasis by means of the stabilization of rhythmic processes of various periods.

Investigations of thermoluminescence dosimetry in the Techa river flood plain: analysis of the new results.

The Techa river region was highly contaminated due to radioactive releases from a nuclear production facility in the period from 1949 to 1956. The inhabitants of the upper Techa river settlements received significant doses of external radiation. The majority of the houses in the upper Techa river villages were demolished after the evacuation of the population in 1956. Only three buildings (red-brick construction) in the former village of Metlino can still be used for thermoluminescence (TL) investigations in an external dose reconstruction study. The radiation source configuration changed in 1956 after an artificial reservoir was created next to Metlinsky pond. Preliminary TL studies showed good properties of the bricks that were sampled from the buildings. This paper presents an analysis of new results of TL investigations obtained on the samples collected from different walls of the buildings. The highest dose values in the range 1-4 Gy were found in bricks collected from the walls of building exposed to the artificial reservoir (Reservoir-10) and values of 1-1.5 Gy were found next to the Metlinsky pond shoreline. The measurements of the radiation source geometry were carried out simultaneously with the dose rates, radionuclide concentration in water and bottom sediments near the wall facing the old river bed. The measurements allow a validation of models used in the current Techa River Dosimetry System (TRDS-2000) to estimate external doses of the former inhabitants of the upper Techa riverside. In particular, the results can be applied for a more correct description of the source geometry in the settlement.

[The characteristics of the restructuring of the circadian dynamics in rat motor activity in response to a phase shift in the photoperiod in the experimental modelling of depression]. / Osobennosti perestroiki tsirkadiannoi dinamiki dvigatel'noi aktivnosti krys v otvet na fazovoe smeshchenie svetovogo rezhima pri éksperimental'nom modelirovanii depressii.

Gradual reorganization of the locomotor activity of rats after a shift in the photoperiod was disrupted under the influence of depressogenic agents (reserpine or chronic pain stress). After the chronic use of the antidepressant amitriptyline the disruption of the reorganization of the daily motor activity typical for reserpine was not observed confirming a specificity of these changes. The results suggest that in the experimental model of depression there arise conditions for functional disturbance of the circadian pacemaker and an increase of sensitivity to the photic Zeitgeber.

[The effect of the deprivation of the paradoxical sleep stage on the temporal dynamics of swimming in rats with antidepressive and depressant exposures]. / Vliianie deprivatsii paradoksal'noi fazy sna na vremennúiu dinamiku plavaniia u krys pri antidepressivnom i depressogennom vozdeistvii.

After REM sleep deprivation the time-course of the forced swimming was reorganized. As shown, reduction of rhythmical index of depression, such effect has an antidepressive nature. In this model potentiation of specific activity of antidepressant imipramine and attenuation of depressive properties of clonidine were observed. These results suggest that shifts in sleep phase structure may be a source of restriction of circadian desynchronosis, upon which depression is based.

[Effect of reserpine on the circadian dynamics of motor activity in rats]. / Vliianie rezerpina na sutochnuiu dinamiku dvigatel'noi aktivnosti u krys.

Administration of reserpine to rats lowers the amplitude of circadian rhythm of motor activity and shifts its acrophase to earlier hours. Efficiency of drug is higher in animals with a well expressed circadian rhythms. Some rats by the character of initial circadian mobility resemble reserpinized animals. Such initially "depressive" rats are characterized by a lesser emotionality and they reorganize with more difficulty the trajectory of avoidance response in Y-maze.

[The effect of phenamine on the avoidance reaction in intact and striatectomized rats]. / Vliianie fenamina na reaktsiiu izbeganiia u intaktnykh i striatéktomirovannykh krys

Various characteristics of a conditioned avoidance reaction were recorded in rats in a Y-maze. Small doses of d,l-amphetamine (0.5 mg/kg) facilitated avoidance response while large ones (5 mg/kg) worsened it. After ablation of the rostral part of the striatum, small doses of the drug had the same effect as before, but no deteriorating action of large doses was observed. The behaviour disturbance is related to the capacity of d,l-amphetamine for activating the nigro-striatal dopaminergic transmission.

[The characteristics of the synchronizing action of melatonin on the dynamics of circadian mobility in rats]. / Osobennosti sinkhroniziruiushchego deistviia melatonina na dinamiku tsirkadiannoi podvizhnosti krys.

Morning (9.00-10.00 h), but not noon, repeated injections of the pineal hormone melatonin (1 or 10 mg/kg daily, during 2 weeks) synchronize the circadian locomotor rhythm of rats. As shown with inverted photoperiod, melatonin facilitates off and on light reactions. Some animals have low and some high hormonal susceptibility. This indicates the role of injections regime and rat's individual reactivity for expressiveness of melatonin synchronizing effect.