259 research outputs found
Properties of dwarf stars in Cygnus OB2
We present the results of investigation of five stars, originally classified
as dwarfs, belonging to Cyg OB2 association, their stellar and wind properties.
Using both TLUSTY and CMFGEN codes we derived effective temperatures, surface
gravities, chemical abundances, mass-loss rates and projected rotation
velocities. Due to the fact that distance to the stars is well known, we were
able to estimate their luminosities. Using evolutionary models we estimated the
ages of these sample stars and find that lower mass ones - MT282 and MT343 -
belong to older population of the association. Their ages are greater than 10
Myr. The ages of three other stars - MT317, MT299, MT259 - are between 4-6 Myr.Comment: 16 pages, 10 figures, accepted for publication in PAS
Disorder-driven transition to tubular phase in anisotropic two-dimensional materials
We develop a theory of anomalous elasticity in disordered two-dimensional
flexible materials with orthorhombic crystal symmetry. Similar to the clean
case, we predict existence of infinitely many flat phases with anisotropic
bending rigidity and Young's modulus showing power-law scaling with momentum
controlled by a single universal exponent the very same as in the clean
isotropic case. With increase of temperature or disorder these flat phases
undergo crumpling transition. Remarkably, in contrast to the isotropic
materials where crumpling occurs in all spatial directions simultaneously, the
anisotropic materials crumple into tubular phase. In distinction to clean case
in which crumpling transition happens at unphysically high temperatures, a
disorder-induced tubular crumpled phase can exist even at room-temperature
conditions. Our results are applied to anisotropic atomic single layers doped
by adatoms or disordered by heavy ions bombarding.Comment: 18 LaTex pages, 6 figure
Treatment for low back pain, use of meloxicam
To manage patients with low back pain is an urgent problem of modern medicine. The paper considers the main causes of chronic nonspecific lumbago and the principles of its diagnosis and treatment in the context of evidence-based medicine. Medical treatment using analgesics (nonsteroidal anti-inflammatory drugs (NSAIDs), weak opioids), antidepressants, therapeutic exercises, and cognitive-behavioral therapy as components of a multidisciplinary treatment is noted to be highly effective. The efficacy and side effects of NSAIDs, the high efficiency and safety of using meloxicam in different dosage forms are outlined.The authors set forth their experience in treating 85 patients with chronic low back pain and an observation of a female patient who has concurrent chronic migraine and abuses analgesics
The Tunka Experiment: Towards a 1-km^2 Cherenkov EAS Array in the Tunka Valley
The project of an EAS Cherenkov array in the Tunka valley/Siberia with an
area of about 1 km^2 is presented. The new array will have a ten times bigger
area than the existing Tunka-25 array and will permit a detailed study of the
cosmic ray energy spectrum and the mass composition in the energy range from
10^15 to 10^18 eV.Comment: 3 pages, 2 figures, to be published in IJMP
Bayesian approach to estimations of star-formation regions physical parameters by few methanol lines
Показано, что использование Байесовского подхода позволяет оценить температуру газа и удельную лучевую концентрацию метанола в областях звездообразования по двум радиолиниям метанола, плотность газа по четырем. Полученные значения физических параметров хорошо согласуются с независимыми оценками.We show that Bayesian approach is useful for estimating kinetic temperatures and methanol specific column densities of starformation regions by only two methanol lines and hydrogen number densities by four lines. Calculated physical parameters’ values are in good agreement with values that were estimated in other ways.Работа выполнена при поддержке Правительства Российской Федерации (постановление № 211, контракт №02.A03.21.0006) и Министерства образования и науки Российской Федерации (базовая часть государственного задания, РК №AAAA-A17-117030310283-7)
Tensiometric estimation of material properties of tissue spheroids
Tissue spheroids have been proposed to use as building blocks in biofabrication and as bioinks in 3D bioprinting technologies. Tissue fusion is an ubiqious phenomenon during embryonic development. Biomimetic tissue spheroid fusion is a fundamental constructional principle of emerging organ printing technology because closely placed tissue spheroids could fuse into tissue and organ-like constructs in fusion permissive bioprintable hydrogel. From physical point of view tissue spheroids could be considered as a visco-elastic-plastic soft matter or complex fluid. We hypothesize that quantitative estimation of material properties of tissue spheroids using tensiometry could predict their tissue spreading and tissue fusion behavior as well as provide a powerful insight about possible speed of post-printed tissue and organ-like constructs compaction and maturation. Tissue spheroids from human fibroblasts, ovine and human chondrocytes and immortalised human keratinocytes have been biofabricated using non-adhesive cell culture plates (Corning, USA). For estimation of material properties of tissue spheroids commercial tensiometer Microsquisher have been emploied (CellScale, Toronto, Canada). Modulus of elasticity of tissue spheroids have been calculated based on peformed tissue compression tests. In order to identify structural determinants of material properties of tissue spheroids standard perturbants of cytoskeleton such as Cytochalasin D (Sigma, USA) for disruption of microfilaments and Nocodazole (Sigma, USA) for disruption of microtubules have been used. Viability of tissue spheroids have been also estimated and their morphology have been analysed using light microscopy, histochemistry, immunohistochemistry, semithin sections stained wih toluidine blue and transmission and scanning electron microscopy. Kinetics of tissue spheroids spreading on electrospun polyurethane matrices have been analysed. Kinetics of two closely placed tissue spheroids fusion have been analysed in hanging drop. Additionally toxic effect of water solution of paramagnetic gadolinium salt (Omniscan®, GE Health Care, USA) on material properties of tissue spheroids have been investigated. It have been demonstrated that material properties of tissue spheroids biofabricated from different cell types have different modulus of elasticity. Even tissue spheroids biofabricated the same cell types but from different species have different material properties. Incubation with Cytochlasin D dramatically reduces estimated material properties of tissue spheroids. Incubation with Nocodazole does not significantly change material properties of tissue spheroids. Material properties of tissue spheroids from chondrocytes (chondrospheres) correlates very well with increasing deposition and accumulation of extracellular matrix (confirmed by expression of collagen type II and glycosoaminoglycans). The incubation with toxic concentration of gadolinium solution dramatically reduces material properties of chondrospheres. There is no any significant correlation between material properties of tissue spheriods and their spreading kinetics. However, there is a certain correction between material properties of tissue spheroids and their tissue fusion kinetics. Our data demonstrate that beside already well established role of cell adhesion receptors such as cadherin and integrins in the realisation of cell cohesion inside tissue spheroids the structural determinants of material properties of tissue spheroids also include components of cytoskeleton such as actin micofilaments and accumulated extracellular matrix. It is possible to predict post-printing tissue fusion behaviour of tissue spheroids based on preliminary estimation of their material properties. Finally, it have been also shown that material properties of tissue spheroids correlate with their viability. Thus, tensiometry is a valuable method for systematic characterization of material properties of tissue spheroids and for prediction of tissue spheroids post-printed tissue fusion behaviour
Treatment for mixed cognitive impairments and emotional disorders in young and middle-aged patients
Objective: to evaluate the efficacy of Tanakan® (EGB761®) used in young and middle-aged patients with mixed cognitive impairments (CI) and emotional diseases.Patients and methods. An open-label observational study of the efficacy of Tanakan® was conducted in 54 patients aged 18–4 years with CI and psychoemotional disorders. Tanakan® was administered at a daily dose of 120 mg (40 mg t.i.d) for 3 months.Results. Tanakan® therapy resulted in health improvement, as shown by the HAM (Health, Activity, Mood) questionnaire; the mean score of the latter increased from 3.86 at baseline to 4.84 after 3 months of treatment. There were improvements in three HAM questionnaire items: the mean score of the item «Health» increased from 3.69 to 4.79; that of the item «Activity» from 3.65 to 4.58, and that the item «Mood» from 4.25 to 5.14 after the completion of the investigation.Tanakan® therapy also demonstrated improvements in memory (the mean number of correctly repeated words increased from 5.7 to 6.7 at the beginning of a visit and from 4.2 to 5.8 at its end) and in attention (the mean symbol-digit coding test score increased from 48.1 to 55.7%. There were no clinically relevant differences between patients with higher and secondary education in the efficacy of Tanakan®.Conclusion. Tanakan® had a very good safety profile; no adverse drug events were recorded during the investigation. Almost all the 53 (98.1%) of the 54 patients were satisfied with Tanakan® therapy results after 3 months of treatment
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