145 research outputs found

    Atmosphere dynamic processes structure at 80-105 km altitude

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    Determination of wind velocity by means of Doppler meteor radars is based on the assumption that an ionized meteor trail drifts together with the neutral atmosphere. From the Doppler frequency shift it is possible to estimate the radial velocity of the trail drift. Conversion of the recorded radial velocity to the true wind velocity vector in the given space region depends both on the radar technical parameters and the chosen atmospheric motion model. The atmospheric dynamic processes structure is considered

    Correlative Microscopy: A Potent Tool for Biomedicine

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    The correlative microscopy method based on a combination of optical and electronic techniques that is increasingly widely used now, has a number of limitations. Here, an alternative approach is considered that uses scanning probe microscopy (SPM) technique to get high-resolution and ultra-high-resolution data. SPM greatly increases the possibilities of collecting new information (on topological, morphological, electrical, magnetic etc. properties). To obtain three-dimensional distributions of different parameters of the sample, ultramicrotomography is used, which allows to scan the sample in steps of up to 20 nm. The principal advantage of the approach is that spectral data are used which due to the combination in near field microscopy can be gained with high and ultrahigh resolution. All above mentioned features are implemented in a single instrument, which allows to have 3-D data and their distributions at the same instrumental platform. A special feature of the approach is the possibility to use all the power of micro(nano)spectral methods. Therefore, it would be more correct to name the proposed approach ”Correlative microspectroscopy”. Keywords: correlative microscopy, correlative microspectroscopy, scanning near-ielf optical microscopy, ultramicrotomography, Raman, TER

    Design of the Model of Ratiometric Polymer Nanobiothermometer Based on Quantum Dots

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    To solve many modern biological and biotechnological tasks it is necessary to realize strictly control and regulation of temperature of the cells and their organelles. Thi stasks include control of various exo- and endothermic reactions, monitoring of tissues‘ and individual cell‘s temperature in in vitro researches and in vivo procedures such as the hyperthermia procedure that used for cancer treatment. The today known methods of measuring and controlling of temperature at the cellular level can not provide the necessary level of locality and accuracy due to too big size and heightened sensitivity to external factors. The real alternative of existing today methods is nanoscale temperature biosensor operating on a ratiometric principle and based on the composite structure from polymers and colloidal quantum dots. In this paper we present a working model and plan of investigation of ratiometric nanoscale polymer nanobiothermometer based on quantum dots. Keywords: thermosensors, quantum dots, local temperature, polymers, temperature measuremen

    Technology for Creation and Detailed Analysis of Polymer Composites with Uniform Distribution of Quantum Dots and Liquid Crystals

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    One of the most actual tasks in biotechnology is the creation of a new generation of nanobiosensors with improved brightness, photo stability, and sensitivity. Compositions of polymers and colloidal quantum dots (QDs) are the most promising base to develop such sensors. This work presents the technology for creation and detailed analysis of nanostructured composite films based on polypropylene matrices with uniformly distributed CdSe/ZnS quantum dots and liquid crystals. Methods of optical microscopy, scanning probe microscopy and confocal fluorescen tmicrospectroscopy were used. The presence of liquid crystals in the composite allows additional control of QDs fluorescence. The methodology proposed is applicable not only to polypropylene, but also to other porous polymers. The results of this work indicate the possibility of creating high-quality polymer/QDs composite materials and open the way to the development of nanomaterials (nanosensors) with optical properties sensitive to various environmental parameters (electric field, photo irradiation, mechanical action, etc.). Keywords: quantum dot-polymer composites, nanoporous polypropylene, fluorescenc

    Porous matrixes based on ion-irradiated polymer as templates for synthesis of nanowires

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    Irradiation with swift heavy ions is usually used for production of track membranes (nuclear filters). These membranes traditionally used as filters for fine filtration in medicine and biology. Another application is matrixes for so called matrix synthesis. The idea of this technique is to fill pores by any desired material- metal,polymer, semiconductor and so on. This work is devoted to formation of membrane for template synthesis, to investigation of filling process and to study some properties of obtained structures. It was found that filtration track membranes are not the best material for template synthesis –another type of matrixes are needed- with different pores profiles and parallel pores orientation These parameters could be obtained during irradiation. Different types of etching gave possibility to vary by will the shape of the pores and to obtain pores with conical shape. The process of etching in the alkali solution in mixture of water and alcohol was investigated. The main part of the work devoted to fabrication of micro- and nanowires via electrodeposition. Different types of metals-copper, silver, cobalt and nickel were used for galvanic deposition of the pores. Two types of the processes- galvanostatic and potentiostatic were investigated. It was also demonstrated that obtained metallic nanowires could be used as the substrates for deposition of the probe (biological molecules) in mass-spectrometer. The application of such structures in non-linear optic was also described. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2083

    Evaluation of interspecific populations of grapevine in breeding for complex resistance to fungal diseases and phylloxera

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    Roentgenoscopy was used as a method to determine the quality of hybrid seeds and to predict the development of viable plants from interspecific hybridization. The seeds were grouped into five classes of quality (embryo classes) depending on embryo size and degree of endosperm development As the index number of a class increased, the proportion of plantlets and vigorous plants produced also increased. In order to evaluate genotypic peculiarities of the original forms and seedlings, the seedlings were studied at the juvenile stage of ontogeny. Analysis of development of the hybrids studied during 5-6 years under conditions of complex infection pressure at a special planting site made it possible to evaluate the degree of their resistance to phylloxera, pathogenic soil microflora and fungal diseases and to eliminate susceptible genotypes. The heritability of resistance to fungal diseases (mildew, oidium, grey rot) and phylloxera was studied, conclusions were made concerning the combining ability of the original forms, and these forms were evaluated as donors of the desirable characters. Using transgressive resistant hybrids as donors in backcrossing provided improved quality with a broad range of resistance variability, which made it possible to select promising genotypes

    Diagnosis of Cervical Cancer Using Raman Spectroscopy

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    The aim of the study was to develop a method of detecting cervical cancer using Raman spectroscopy in the examination of biopsy and surgical material. Significant differences in the spectral characteristics between the tissues of the intact cervix and tissues with squamous cell carcinoma of the cervix have been revealed. Intensity of fluorescence in cervical cancer was higher than in intact cervical tissue.     Keywords: cervical cancer, squamous cell carcinoma, diagnosis of cervical cancer, fluorescence in cervical cancer, Raman spectroscopy for the diagnosis of cervical cance

    Early markers of pathological left ventricular remodeling in patients after ST-elevation myocardial infarction according to speckle-tracking echocardiography

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    Aim. To assess early predictors of pathological remodeling in patients after ST-elevation myocardial infarction (STEMI) using speckle-tracking echocardiography (STE).Material and methods. The study included 114 STEMI patients aged 52 (44; 58) years. A two-dimensional echocardiography was performed with the analysis of standard parameters and STE with an analysis of strain and rotational characteristics of the myocardium. In addition, brain natriuretic peptide and troponin-I concentration was determined. The development of pathological post-infarction remodeling within 12-month follow-up was assessed as an end point. Depending on the outcome, 2 groups were formed: group 1 — patients with pathological remodeling (PR), n=45 (39,5%), group 2 — patients without PR, n=69 (60,5%).Results. Early remodeling was detected in 24 (53,3%) people, mid-term — in 15 (33,4%), and late remodeling — in 6 (13,3%). In the PR group, heart failure (HF) was detected in 100% of patients, while in non-PR group, 23 (33,3%) patients had no signs of HF.In the early period of myocardial infarction, each of following indicators with high sensitivity and specificity predicts postinfarction pathological dilatation: global longitudinal strain (GLS) <11,7%, global circular strain (GCS) <12,4%, and a Twist decrease to 7,8o. A multivariate logistic regression model was created for the formation of pathological remodeling in patients with STEMI, which included GLS, global radial deformation (GRS), end-systolic volume index (ESVI), determined on days 7-9 of STEMI.Conclusion. GLS, GCS, and left ventricular Twist are independent highly sensitive and specific predictors of pathological remodeling. The following early predictors of postinfarction pathological dilatation have been established: reduced GLS  in combination with higher GRS and left ventricular ESVI

    Myocardial strain parameters and autonomic balance in various variants of the postinfarction course in patients receiving high-dose atorvastatin therapy

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    Aim. To study parameters of left ventricular (LV) strain and heart rate variability (HRV) in patients with ST-segment elevation myocardial infarction (STEMI) in various variants of postinfarction receiving high-dose atorvastatin therapy.Material and methods. The study included 96 patients with STEMI. All patients underwent two-dimensional speckle tracking echocardiography and 24-hour electrocardiographic monitoring with HRV analysis. The included individuals were divided into groups without pathological LV remodeling (R (-), n=57) and with pathological post-infarction LV remodeling (R (+), n=39), the criterion for which was an increase in end-diastolic and/or end-systolic volume >20% and >15%, respectively. Further, depending on the achievement of target low-density lipoprotein cholesterol (LDL-C) (1,5 mmol/l and/or a decrease of more than 50%), the following subgroups were identified: 17 (43,6%) people, who reached target LDL-C levels (group 1), 22 (56,4%) patients, who did not reach target LDL-C levels (group 2). Similar subgroups were identified in the R (-) group as follows: 28 (49,1%) people, who reached target LDL-C levels (group 3) and 29 (50,9%) people, who did not reach target LDL-C levels (group 4).Results. Starting from the 12th week of follow-up, worsening of global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain (p<0,01) was registered in group 2. In group 1, worsening of these parameters was registered only by the 48th week (p<0,01). In group 3, an increase in GLS was revealed by the 48th week (p=0,001), GCS and GRS — by the 12th week (p<0,05). In group 4, favorable changes were observed only in GLS and GCS by the 48th week (p<0,01). A significant change in HRV parameters was observed in group 3. By the 48th week, there was an increase in temporal indicators (SDNN, SDNNi, SDANN, RMSSD, pNN50) (p<0,0001) and total spectrum power (p=0,0001) due to an increase in all frequency indicators (p<0,001), while the index of autonomic balance L/H decreased by 33% (p=0,002). In group 4, only SDNN, SDANN and pNN50 (p<0,05), as well as the total spectrum power (p=0,001) increased, but no change in frequencies. According to intergroup analysis in the acute period of STEMI, group 4 patients had higher HRV than in group 3 (p<0,05).Conclusion. High-dose atorvastatin therapy improves LV strain characteristics and autonomic balance during the rehabilitation period after STEMI
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