310 research outputs found
Simulation of Thermal Surface Waves in a Protoplanetary Disk in a Two-Dimensional Approximation
Theoretical models predict that the obscuration of stellar radiation by
irregularities on the surface of a protoplanetary disk can cause
self-generating waves traveling towards the star. However, this process is
traditionally simulated using the 1+1D approach, the key approximations of
which - vertical hydrostatic equilibrium of the disk and vertical diffusion of
IR radiation - can distort the picture. This article presents a two-dimensional
radiative hydrodynamic model of the evolution of an axially symmetric gas and
dust disk. Within this model, but using simplified assumptions from 1+1D
models, we have reproduced the spontaneous generation and propagation of
thermal surface waves. The key conclusion of our work is that taking into
account two-dimensional hydrodynamics and diffusion of IR radiation suppresses
the spontaneous generation and development of thermal waves observed in the
1+1D approximation. The search for the possibility of the existence of surface
thermal waves should be continued by studying the problem for various
parameters of protoplanetary disks.Comment: Accepted for publication in Astronomy Reports (2022
Critical fields for vortex expulsion from narrow superconducting strips
We calculate the critical magnetic fields for vortex expulsion for an
infinitely long superconducting strip, using the Ginzburg-Landau formalism. Two
critical fields can be defined associated with the disappearance of either the
energetic stability or metastability of vortices in the center of the strip for
decreasing magnetic fields. We compare the theoretical predictions for the
critical fields in the London formalism with ours and with recently published
experimental results. As expected, for narrow strips our results reproduce
better the experimental findings.Comment: 5 pages, 5 figure
Fibrogenic and fibrolytic potential of differently activated human macrophages
Macrophages are involved in the regulation of fibrogenesis and turnover of the extracellular matrix. One way to perform this function is through the production of profibrotic and fibrolytic factors including fibronectin, laminin, collagen, and extracellular matrix proteases. The production of most of them has been well studied in experimental models; however, much remains unclear regarding human macrophages. Therefore, the aim of this study was to study the content of extracellular matrix proteases (MMP-2 and MMP-9, cathepsin L), their inhibitors (TIMP-1), and collagen (type I) in supernatants of differently activated human macrophages. We compared macrophages differentiated by M-CSF or GM-CSF and further polarized in M1 with lipopolysaccharide, in M2a with IL-4, and in M2c with dexamethasone. Macrophages was obtained from peripheral blood monocytes. The content of MMPs, TIMP, cathepsin, and collagen was determined using appropriate ELISA kits. The results obtained demonstrate that differentiation factors are more important for the production of the above factors compared to polarizing stimuli (lipopolysaccharide, IL-4, dexamethasone). Moreover, macrophages differentiated by M-CSF showed predominantly antifibrotic activity because of pronounced MMPs production, while GM-CSF-induced cultures, on the contrary, were characterized by profibrotic properties due to the high level of TIMP-1 and type I collagen. M1, M2a, and M2c, induced by M-CSF, differed only in MMP-2 production, and M2a produced this metalloproteinase more than other subtypes. In the case of GM-CSF-differentiated cells, a higher level of production of TIMP-1 and, to a lesser extent, type I collagen was characteristic of M1, whereas M2c have minimal concentration of them among GM-CSF-induced macrophage subtypes. Concerning the level of cathepsin L production was relatively constant and did not depend on the generation conditions (differentiation and polarizing signals). Thus, the data obtained help to identify macrophage subtypes with anti- or profibrotic potential and may be useful for the development of cell therapy for diseases associated with fibrogenesis dysregulation
Anomalies of Density, Stresses, and the Gravitational Field in the Interior of Mars
We determined the possible compensation depths for relief harmonics of
different degrees and orders. The relief is shown to be completely compensated
within the depth range of 0 to 1400 km. The lateral distributions of
compensation masses are determined at these depths and the maps are
constructed. The possible nonisostatic vertical stresses in the crust and
mantle of Mars are estimated to be 64 MPa in compression and 20 MPa in tension.
The relief anomalies of the Tharsis volcanic plateau and symmetric feature in
the eastern hemisphere could have arisen and been maintained dynamically due to
two plumes in the mantle substance that are enriched with fluids. The plumes
that originate at the core of Mars can arise and be maintained by the anomalies
of the inner gravitational field achieving +800 mGal in the region of plume
formation, - 1200 mGal above the lower mantle-core transition layer, and -1400
mGal at the crust.Comment: 9 pages, 5 figure
EFFECT OF FLUOXETINE ON SLEEP ARCHITECTURE IN PATIENTS WITH METABOLIC SYNDROME AND OBSTRUCTIVE SLEEP APNEA SYNDROME
Aim. To study effect of fluoxetine on sleep architecture in patients with metabolic syndrome and obstructive sleep apnea syndrome.Material and methods. 98 patients with obstructive sleep apnea syndrome and metabolic syndrome (aged 54.3±8.7 y.o.) were included into the study. All patients received fluoxetine 20 mg once daily during 6 months. Influence of fluoxetine on sleep architecture was evaluated with special questionnaire and by polysomnography, including electroencephalogram, electrooculogram, mentalis electromyogram and pulseoxymetry.Results. Decrease in wake time after sleep onset (Δ33%; р<0.05) was found at the end of treatment. It resulted in improvement of sleep efficacy index. Decrease in respiratory sleep disorders index (Δ20%) and rising of blood oxygen saturation (Δ12%; р<0.05) was also found. Improvement of the sleep architecture (reduction in the 2nd phase of slow wave sleep by 15%, increase in delta-sleep (Δ71%) and rapid eye movement sleep (Δ25%; р<0.05) was also observed. Besides reduction in body mass index after fluoxetine therapy (Δ12%; р<0.05) was found. Serious adverse effects were not registered.Conclusion. Fluoxetine use in patients with metabolic syndrome and obstructive sleep apnea syndrome shown positive effect on objective indices of sleep architecture and respiratory sleep disorders. It improved adaptive function of the sleep and contributed to reduction in sleep disorders
Clinical value of oral fluid chemokines in chronic periodontitis
Activation of cytokine network is one of the key mechanisms in immunopathogenesis of chronic periodontitis (CP), a common dental disease. Therefore, the study of the proteomic (including cytokine) profile of saliva is not coincidentally considered among global research areas in periodontology. However, the existing data on the contents of cytokines / chemokines in oral fluid (OF) in CP are contradictory. This ambiguity of the results can be associated both with a variety of methodological approaches to the cytokine determination, and with different severity of CP in the studied cohorts of patients. Moreover, recent systematic reviews and meta-analyses show that clinical value of chemokines in CP is also not yet determined thus indicating a need for future research in this area.The aim of this study was to assess clinical and diagnostic value of some chemokines from oral fluid in chronic mild periodontitis. The work was based on a study of 18 patients diagnosed with mild chronic periodontitis (MCD-10 K05.3) and 12 practically healthy volunteers with relatively intact periodontal tissue. The diagnosis was based on standard clinical and radiological criteria. In all cases the levels of 8 chemokines were determined using multiparametric fluorescence analysis with magnetic microspheres (xMAP technology, Luminex 200, USA). Statistical analysis was carried out by methods of non-parametric statistics. To determine the predictive value of the test, ROC analysis was performed.It has been shown that CP is accompanied by increased levels of CXCL1 (5.5-fold), CXCL8 (8.1-fold), CXCL12 (3.5-fold), CCL2 (2.7-fold). At the same time, the level of other chemokines did not change significantly. There was a lack of correlations between individual parameters in the group of patients with CP, in contrast to the control group, thus, probably reflecting disturbed mechanisms of “balance” regulation of chemokines. By means of ROC analysis, highly sensitive biomarkers of chronic mild periodontitis were identified. The diagnostic sensitivity and diagnostic specificity were for CXCL1 (91 and 75%, respectively), CXCL8 and CXCL12 (95 and 75%), CCL2 (82 and 75%). The data obtained indicate that the salivary chemokines CXCL1, CXCL8, CXCL10, CXCL12, CCL2 can be considered potential biomarkers of mild chronic periodontitis
Unity of Diagnostics and Rehabilitation as a Principle of Organization of Complex Support for Children with Disabilities
В статье рассматриваются вопросы организации комплексного сопровождения детей с ограниченными возможностями здоровья в школе-интернате.At present, the problem of psycho-pedagogical support for students with disabilities is becoming more and more urgent due to the increase in the number of students in this category. The ar¬ticle deals with the organization of comprehensive support for children with disabilities. The data of the analysis of numerous studies indicate that the activity of specialists within the framework of the psycho-pedagogical council (PPC) is an important and integral part of the system of psycho-pedagogical support for children with disabilities and should be based on the principle of diagnosis and rehabilitation
Екстракорпоральна детоксикація у хворих на сепсис при ускладненому синдромі діабетичної стопи
Under our supervision there were 713 patients with sepsis who were treated in septic city center with beds diabetic foot for the period 1991–2015rr. In 90.9 % of cases (648 patients) were the cause of sepsis cellulitis soft tissues of different localizations (1 group). In 65 patients (9.1 %) – wet gangrene of the lower limbs and purulent necrotic processes diabetic foot (group 2). During a comprehensive study of patients with sepsis found that last appeared in 81.2 % of cases (579 patients) against opportunistic diseases, which are 15.1 % (108 patients) had signs of decompensation. In this case the adjacent pathology significantly more often (p <0.05) was reported in patients with severe sepsis and its complicated forms.Intoxication syndrome of a severity was found in all patients with sepsis. Because of detoxification measures were required component of complex intensive care. Despite some effectiveness sessions discretic plasmafaresis (judging by the positive dynamics of objective markers of endotoxemia and other indicators of homeostasis) treatment outcomes of patients with sepsis remain poor. We analyzed survival in a representative group of patients (n=216), which are already complex treatment discretic plasmafaresis was not carried out. From the standpoint of evidence-based medicine 'reference point' was the 28th postoperative day. At 25–30-th day of stay in the hospital died 12 patients with PF used 2–3 times, 11 more patients with PF treatments 3–5 times longer than died in 30 days. Mortality in septic shock – 68.9 % (40 of 58 dead patients) patients of group 1 and 76.2 % (10 of 13 patients) in group 2. The syndrome of multiple organ failure respectively 77.3 % (34 patients) and 87 5 % (6 patients).ід спостереженням перебували 713 хворих на сепсис, які лікувалися в міському гнійно-септичному центрі з ліжками діабетичної стопи у період 1991–2015 рр. У 90,9 % випадків (648 хворих) причиною розвитку сепсису були флегмони м’яких тканин різної локалізації (1-ша група), в (9,1 %) випадків 65 хворих – волога гангрена нижньої кінцівки та гнійно-некротичні процеси стопи діабетика (2-га група). У процесі комплексного дослідження хворих на сепсис встановлено, що останній виник у 81,2 % випадків (579 хворих) на тлі супутніх захворювань, які в 15,1 % (108 пацієнтів) мали ознаки декомпенсації. При цьому випадки суміжної патології вірогідно частіше (р<0,05) було зареєстровано в пацієнтів із тяжким сепсисом і його ускладненими формами. Інтоксикаційний синдром того або іншого ступеня тяжкості відмічали у всіх хворих на сепсис. Тому проведення детоксикаційних заходів було обов’язковим компонентом комплексної інтенсивної терапії. Незважаючи на певну ефективність сеансів дискретного плазмаферезу (ПФ), якщо судити про позитивну динаміку об’єктивних маркерів ендотоксикозу та інших показників гомеостазу, кінцеві результати лікування хворих на сепсис бажають бути кращими. Проаналізовано виживаність у репрезентативній групі хворих (n=216), яким у системі комплексного лікування ПФ не проводили. З позиції доказової медицини ‘крапкою відліку’ була 28-ма доба післяопераційного періоду. На 25–30 доби перебування в стаціонарі померли 12 хворих, в яких використовували ПФ 2–3 рази, ще 11 пацієнтів із процедурами ПФ 3–5 разів померли в строки більше 30 діб. Летальність при септичному шоці становила 68,9 % (померли 40 з 58 хворих) пацієнтів 1-ї групи та 76,2 % (10 з 13 хворих) пацієнтів 2-ї групи, при синдромі полі органної недостатності 77,3 % (34 хворих) та 87,5 % (6 пацієнтів) відповідно
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