40 research outputs found
Interaction of Nitrogen-Vacancy Centers in Diamond with a Dense Ensemble of Carbon-13
The nitrogen-vacancy center in diamond attracts a lot of attention in sensing
applications, mainly for temperature, magnetic field, and rotation
measurements. Nuclear spins of carbon-13 surrounding the nitrogen-vacancy
center can be used as a memory or sensing element. In the current work, a
diamond plate with a relatively large concentration of carbon-13 was
synthesized and examined. The spectrum of optically detected magnetic resonance
was recorded and analyzed in a magnetic field range of 5-200 G. A
strain-independent measurement technique of carbon-13 isotope concentration
based on the analysis of magnetic resonance spectra was developed.
Additionally, narrow features in the spectrum were detected and understood
Interleukins 4 and 6 as factors of modulation of subpopulation composition of blood monocytes in patients with ischemic cardiomyopathy
Aim. To evaluate the ratio of the fractions of classical, intermediate, non-classical and transitional monocytes in correlation with the concentration of interleukins 4 and 6 in the blood of patients with ischemic cardiomyopathy.
Methods. 18 patients with ischemic cardiomyopathy (17 men and 1 woman) aged 47-66 years with circulatory insufficiency of functional class II-III according to the classification of heart failure of the New York Heart Association, were examined. The control group included 14 healthy donors matched by gender and age to patients with ischemic cardiomyopathy without any diseases of cardiovascular system and other systems in an exacerbation stage. In blood of the patients with ischemic cardiomyopathy, the relative content of classical (CD14++CD16-), intermediate (CD14++CD16+), non-classical (CD14+CD16+) and transitional (CD14+CD16-) monocytes was assessed by flow cytometry and the concentration of interleukins 4 and 6 by enzyme-linked immunosorbent assay (ELISA).
Results. It was shown that the number of non-classical monocytes in the blood of patients with ischemic cardiomyopathy was 2 times lower than normal (5.05 % [4.08; 6.58] and 10.07 % [9.34; 13.84], respectively, p < 0.01), as well as the concentration of interleukin-4 (0.02 pg/ml [0; 0.04] and 0.15 pg/ml [0.05; 0.65], respectively, p < 0.05). The number of classical monocytes in the blood of patients had a tendency to decrease, and the proportion of intermediate monocytes and the concentration of interleukin-6, on the contrary, were slightly higher than in healthy individuals, and were interdependent (r = 0.61; p < 0.05). The relative content of transitional monocytes in the blood was comparable with that of healthy donors.
Conclusions. The subpopulation composition of blood monocytes in patients with ischemic cardiomyopathy is characterized by a deficiency of the fraction of non-classical monocytes with protective properties against endothelium, and interleukin-4 in the blood with a certain increase in the content of interleukin-6 and the number of intermediate cells with ability to cooperate with T-lymphocytes, which predisposes to diffuse atheromatosis of small coronary arteries and diffuse hypoxic myocardial damage in ischemic cardiomyopathy
Study of suitability of Fricke-gel-layer dosimeters for in-air measurements to characterize epithermal/thermal neutron beams for NCT
The reliability of Fricke gel dosimeters in form of layers for measurements aimed at the characterization
of epithermal neutron beams has been studied. By means of dosimeters of different isotopic composition
(standard, containing 10B or prepared with heavy water) placed against the collimator exit, the spatial
distribution of gamma and fast neutron doses and of thermal neutron fluence are attained. In order to
investigate the accuracy of the results obtained with in-air measurements, suitable MC simulations have
been developed and experimental measurements have been performed utilizing Fricke gel dosimeters,
thermoluminescence detectors and activation foils. The studies were related to the epithermal beam
designed for BNCT irradiations at the research reactor LVR-15 (Řež). The results of calculation and
measurements have revealed good consistency of gamma dose and fast neutron 2D distributions obtained
with gel dosimeters in form of layers. In contrast, noticeable modification of thermal neutron
fluence is caused by the neutron moderation produced by the dosimeter material. Fricke gel dosimeters
in thin cylinders, with diameter not greater than 3 mm, have proved to give good results for thermal
neutron profiling. For greater accuracy of all results, a better knowledge of the dependence of gel dosimeter
sensitivity on radiation LET is needed
BNCT dosimetry: peculiarities and methods
Dosimetry in tissue exposed to the epithermal neutron beams utilized for BNCT is
complex, due to the multiplicity of the possible neutron reactions and consequently of the
secondary radiation that contains photons, charged particles and recoil nuclei. Owing to the
different radiobiological effectiveness of the various components of the absorbed dose, it is
necessary to attain the evaluation of each of them. In addition, the spatial distributions of these
dose components changes considerably with size and shape of the irradiated volume.
Therefore, BNCT dosimetry requires suitably developed calculations and experimental
methods. In this work, Monte Carlo simulations in phantoms of different sizes and shapes have
been developed. Experimental methods for separating the dose components, mainly based on
gel dosimeters and thermoluminescence detectors, have been applied. Moreover, the change in
the absorbed dose resulting from the addition of 157Gd was investigated. Both measurements
and calculations have been done with the BNCT epithermal beam of the LVR-15 reactor
Макрофаги при бактериальных болезнях легких: фенотип и функции (обзор)
This literature review is devoted to the analysis of the role of macrophages in the immunopathogenesis of infectious lung diseases of bacterial etiology. The article summarizes information about the origin of macrophages, their phenotypic and functional heterogeneity. The mechanisms of impaired protective function of innate immunity are associated with the polarization of the program of maturation and activation of macrophages in the direction to tolerogenic or immunoregulatory cells with phenotype of M2. Alveolar macrophages perform a variety of functions (from pro-inflammatory to regenerative) in the development of inflammation in the respiratory organs. Their inherent plasticity suggests that the same macrophages can change their phenotype and function depending on the microenvironment in the inflammatory focus at different stages of the disease. Understanding the mechanisms that regulate macrophage plasticity will be an important step towards realizing the potential of personalized immunomodulatory therapy.Обзор литературы посвящен анализу роли макрофагов в иммунопатогенезе инфекционных заболеваний легких бактериальной этиологии. В статье обобщены сведения о происхождении макрофагов, их фенотипической и функциональной гетерогенности. Механизмы нарушений защитной функции врожденного иммунитета связаны с поляризацией программы созревания и активации макрофагов в направлении толерогенных или иммунорегуляторных клеток с фенотипом М2. Альвеолярные макрофаги выполняют разнообразные функции (от провоспалительной до регенераторной) при развитии воспаления в органах дыхания. Присущая им пластичность свидетельствует, что одни и те же макрофаги могут изменять свой фенотип и функции в зависимости от микроокружения в очаге воспаления на разных стадиях заболевания. Понимание механизмов, которые регулируют пластичность макрофагов, станет важным шагом на пути реализации потенциала персонифицированной иммуномодулирующей терапии
Субпопуляционный состав моноцитов крови и костного мозга у больных с хронической сердечной недостаточностью
The aim of the investigation was to evaluate the ratio of classical (CD14++CD16-), intermediate (CD14++CD16+), nonclassical (CD14+CD16+) and transient (CD14+CD16–) monocytes in the blood and bone marrow in patients with chronic heart failure (CHF) against ischemic cardiomyopathy (ICMP).Materials and methods. 17 patients with ICMP and 14 practically healthy donors were observed. The material of the study was venous blood (in patients and healthy donors) and red bone marrow (in patients). In the materials the relative content of different monocytes subpopulations was determined by flow cytometry. The obtained results were analyzed by statistical methods.Results. It is shown that in the blood of patients the proportion of monocytes with the phenotype CD14++CD16- is 57.77 [of 46.35; 79.76]%, CD14++CD16+ – 25.06 [4.96; 42.31]%, CD14+CD16+ 5.05 [4.08; 6.58]% and CD14+CD16- – 6.03 [3.58; 10.89]%; in the bone marrow – 43.44 [40.54; 44.68]%, 0.16 [0; 1.07]%, 0,54 [0.35; 1.07]% and 54,32 [52.83; 56.08]%, respectively, which is different from the content of the data cells subpopulations in the blood (p < 0.05). At the same time, the content of non-classical monocytes in the patients’ blood is 2 times lower than in healthy donors, and the number of other cells varies within the norm.Conclusion. The differentiation of monocytes into 4 subpopulations in patients with CHF occurs directly in the bloodstream, since mainly the classical and transitional monocyte fractions with the prevalence of the latter are present in the bone marrow. Deficiency of non-classical monocytes of blood in CHF is probably associated with a disruption of their extramedullary differentiation.Цель работы – оценить соотношение классических (CD14++CD16-), промежуточных (CD14++CD16+), неклассических (CD14+CD16+) и переходных (CD14+CD16-) моноцитов в крови и костном мозге у больных с хронической сердечной недостаточностью (ХСН) на фоне ишемической кардиомиопатии (ИКМП).Материалы и методы. Обследованы 17 больных ИКМП и 14 практически здоровых доноров. Материалом для исследования служили венозная кровь (у больных и здоровых доноров) и красный костный мозг (у больных). В материале определяли относительное содержание различных субпопуляций моноцитов методом проточной цитометрии. Полученные результаты анализировали статистическими методами.Результаты. Показано, что в крови у больных доля моноцитов с фенотипом CD14++CD16- составляет 57,77 [46,35; 79,76]%; CD14++CD16+ – 25,06 [4,96; 42,31]%; CD14+CD16+ – 5,05 [4,08; 6,58]% и CD14+CD16- – 6,03 [3,58; 10,89]%; в костном мозге – 43,44 [40,54; 44,68]%; 0,16 [0; 1,07]%; 0,54 [0,35; 1,07]% и 54,32 [52,83; 56,08]% соответственно, что отличается от содержания клеток данных субпопуляций в крови (р < 0,05). При этом содержание неклассических моноцитов в их крови в два раза ниже, чем у здоровых доноров, а численность остальных клеток варьирует в пределах нормы.Заключение. У больных ХСН распределение моноцитов на четыре субпопуляции происходит непосредственно в кровотоке, так как в костном мозге обнаруживаются в основном классическая и переходная фракции моноцитов с преобладанием клеток CD14+CD16+. Дефицит неклассических моноцитов в крови при ХСН, вероятно, связан с нарушением их экстрамедуллярной дифференцировки
The TOTEM Experiment at the CERN Large Hadron Collider
The TOTEM Experiment will measure the total pp cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, will be installed on each side in the pseudorapidity region 3,1 <h< 6,5, and Roman Pot stations will be placed at distances of 147m and 220m from IP5. Being an independent experiment but technically integrated into CMS, TOTEM will first operate in standalone mode to pursue its own physics programme and at a later stage together with CMS for a common physics programme. This article gives a description of the TOTEM apparatus and its performance