1,261 research outputs found
Genetic mechanisms of the influence of light and phototransduction on Drosophila melanogaster lifespan
The light of the visible spectrum (with wavelengths of 380-780 nm) is one of the fundamental abiotic factors to which organisms have been adapting since the start of biological evolution on the Earth. Numerous literature sources establish a connection between the duration of exposure to daylight, carcinogenesis and longevity, convincingly showing a significant reduction in the incidence of cancer in blind people, as well as in animal models. On the other hand, the stimulating nature of the effect of continuous illumination on reproductive function was noted, in particular, the effects of increasing the fecundity of females of various species are known. Increase in motor activity and, as a result, in metabolic rate and thermogenesis during permanent exposure to light also reduces the body's energy reserves and lifespan. In principle, in the context of aging, not only the exposure time, but also the age at the onset of exposure to constant illumination matter, the reverse effects are valid for the maintenance of experimental animals in the constant darkness. Over the long period of the evolution of light signal transduction systems, many mechanisms have emerged that allow to form an adequate response of the organism to illumination, modulating the highly conservative signaling cascades, including those associated with aging and lifespan (FOXO, SIRT1, NF-kB, mTOR/S6k, PPARa, etc). In this review, we consider the relationship between lifespan, photoregimens, and also the expression of the genes encoding the phototransduction cascade and the circadian oscillator elements of animal cells. In the present paper, basic transducers of light and other signals, such as the family of TRP receptors, G proteins, phospholipase C, and others, are considered in the context of aging and longevity. A relationship between the mechanisms of thermoreception, the temperature synchronization of the circadian oscillator and the life span is established in the review. Analysis of experimental data obtained from the Drosophila melano-gaster model allowed us to formulate the hypothesis of age-dependent photoresistance - a gradual decrease in the expression of genes associated with phototransduction and circadian oscillators, leading to deterioration in the ability to adapt to the photoregimen and to the increase in the rate of aging
Features of the intestinal microbiome in patients with thyroid diseases
Introduction. Today the search and development of new methods for diagnosing organic or functional pathology of the thyroid gland with an asymptomatic or clinically nonspecific course is an urgent task of endocrinology and therapy. The functioning of the thyroid gland and the state of the human intestinal microbiome are dynamically interrelated. One of the considered promising methods is mass spectrometry of microbial markers of the human intestinal microbiota.The purpose of the study. To study the microbial spectrum and characteristics of the biotic environment of the intestine in patients with thyroid diseases.Materials and methods. 21 patients were examined (8 men and 13 women, median age 40.5 [31.75; 54] years, respectively; 15 with thyroid disease, 6 without thyroid disease). In addition to the standard clinical and laboratory-instrumental examination, patients, colon contents were examined by chromatography-mass spectrometry of microbial materials. The work used descriptive non-parametric statistics with subsequent interpretation. Mean values of indicators and their variance are presented as median, upper and lower quartiles. In relation to representatives of the fecal microbiota, in addition to absolute values, the frequency of occurrence of the microorganism within the reference range, moderate or pronounced deviations was taken into account. The determination of the statistical significance of differences in the relative frequency value was carried out using Fisher’s exact test. The presentation of the results is implemented in the form of range diagrams, compactly depicting a one-dimensional probability distribution, tables. Results. Differences in the composition of the microbiota of the control group and the experimental group for Alcaligenes spp., Staphylococcus spp., Megamonas hypermegale, Peptostreptococcus anaerobius were revealed.Conclusions. The development of thyroid gland pathology is accompanied by significant deviations in the composition of the fecal microbiota, determined by mass spectrometry of microbial markers. In persons with thyroid pathology, in the absence of clinically significant external influences on the intestinal microbiome, a pronounced decrease in the level of Alcaligenes spp., Staphylococcus spp., is detected, a tendency to a decrease in the level of Megamonas hypermegale, Peptostreptococcus anaerobius is determined. Further differentiated study of the composition of the intestinal microbiome in patients with thyroid diseases is required, depending on the nosological affiliation and the nature of the endocrine dysfunction
Хронологічні ретроспективні показники становлення та розвитку аптечної справи в Україні
The article presents the results of the study and generalization of organization and legal aspects of the pharmacy formation in Ukraine in the period of 1709-1917. A detailed analysis of formation and development of the pharmacy chain and characteristics of the personnel policy of pharmacies within a specified period are presented in the article.В статье приведены результаты изучения и обобщения организационно-правовых аспектов становления фармации в Украине в период 1709-1917 гг. Осуществлен детальный анализ становления и развития аптечной сети и особенностей кадровой политики аптечных учреждений в течение указанного периода.У статті наведено результати вивчення та узагальнення організаційно-правових аспектів становлення фармації в Україні у період 1709-1917 рр. Здійснено детальний аналіз становлення і розвитку аптечної мережі та особливостей кадрової політики аптечних установ протягом зазначеного періоду
Determination of the Leading Physical Qualities of Athletes Specializing in the Triple Jump
Цель работы — провести теоретический анализ и обобщить информацию о ведущих физических качествах легкоатлетов, специализирующихся в тройном прыжке, а также конкретизировать данные о ведущих физических качествах прыгунов тройным прыжком.The purpose of the work is to conduct a theoretical analysis and summarize information about the leading physical qualities of athletes specializing in the triple jump, as well as to concretize data on the leading physical qualities of triple jumpers
On the roots of the Poincare structure of asymptotically flat spacetimes
The analysis of vacuum general relativity by R. Beig and N. O Murchadha (Ann.
Phys. vol 174, 463 (1987)) is extended in numerous ways. The weakest possible
power-type fall-off conditions for the energy-momentum tensor, the metric, the
extrinsic curvature, the lapse and the shift are determined, which, together
with the parity conditions, are preserved by the energy-momentum conservation
and the evolution equations. The algebra of the asymptotic Killing vectors,
defined with respect to a foliation of the spacetime, is shown to be the
Lorentz Lie algebra for slow fall-off of the metric, but it is the Poincare
algebra for 1/r or faster fall-off. It is shown that the applicability of the
symplectic formalism already requires the 1/r (or faster) fall-off of the
metric. The connection between the Poisson algebra of the Beig-O Murchadha
Hamiltonians and the asymptotic Killing vectors is clarified. The value H[K^a]
of their Hamiltonian is shown to be conserved in time if K^a is an asymptotic
Killing vector defined with respect to the constant time slices. The angular
momentum and centre-of-mass, defined by the value of H[K^a] for asymptotic
rotation-boost Killing vectors K^a, are shown to be finite only for 1/r or
faster fall-off of the metric. Our center-of-mass expression is the difference
of that of Beig and O Murchadha and the spatial momentum times the coordinate
time. The spatial angular momentum and this centre-of-mass form a Lorentz
tensor, which transforms in the correct way under Poincare transformations.Comment: 34 pages, plain TEX, misleading notations changed, discussion
improved and corrected, appearing in Class. Quantum Gra
USp(2k) Matrix Model: Nonperturbative Approach to Orientifolds
We discuss theoretical implications of the large k USp(2k) matrix model in
zero dimension. The model appears as the matrix model of type IIB superstrings
on a large orientifold via the matrix twist operation. In the
small volume limit, the model behaves four dimensional and its T dual is
six-dimensional worldvolume theory of type I superstrings in ten spacetime
dimensions. Several theoretical considerations including the analysis on planar
diagrams, the commutativity of the projectors with supersymmetries and the
cancellation of gauge anomalies are given, providing us with the rationales for
the choice of the Lie algebra and the field content. A few classical solutions
are constructed which correspond to Dirichlet p-branes and some fluctuations
are evaluated. The particular scaling limit with matrix T duality
transformation is discussed which derives the F theory compactification on an
elliptic fibered K3.Comment: LaTeX, 29 pages, 3 figures. PostScript problems are fixe
Bone marrow MRI after autologous transplantation and the effect of residual tumor on progression-free survival of multiple myeloma patients
Background . The study of influence of residual tumor mass, determined by magnetic resonance imaging (MRI), on the progression-free survival (PFS) remains an actual problem. Since the visual assessment of tumor bone marrow lesion can be one of the criteria for the subsequent personalized treatment choice in multiple myeloma patients.The objective of study was to determine the effect of bone marrow lesions detected by MRI after autologous hematopoietic stem cells transplantation (auto-HSCT) on PFS in multiple myeloma patients.Materials and methods . The prospective study included 60 patients who underwent spine and pelvic bones MRI on the 100 th day after autoHSCT.Results . Focal bone marrow changes were found in 47 of them – from 1 to 56 lesions (mean 6 ± 9). Significant (p = 0.01) differences of PFS in multiple myeloma patients depending on the presence or absence of tumor mass on 100 th day after auto-HSCT were revealed: with MRI negative status, 2-year PFS was 89 % versus 50 % in a group of patients with residual tumor mass.Conclusion . MRI-negative status after auto-HSCT is a favorable prognostic factor contributing to prolonged disease-free survival
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