Статьи журнала - Cardiometry
Все статьи: 527
Статья научная
Aims This paper deals with solving of a century-old paradox of linear stability for the Hagen-Poiseuille flow. A new mechanism of dissipative hydrodynamic instability has been established herein, and a basis for the forming of helical structural organization of bloodstream and respective energy effectiveness of the cardiovascular system functioning has been defined by the authors. Materials and Theory of hydrodynamic instability, Galerkin’s approximation. methods Results A new condition Re > Rethmin » 124 of linear (exponential) instability of the Hagen-Poisseuille (HP) flow with respect to extremely small by magnitude axially-symmetric disturbances of the tangential component of the velocity field is obtained. The disturbances necessarily shall have quasi-periodic longitudinal variability along the pipe axis that corresponds to the observed data. Conclusion We show that the obtained estimate of value of Rethmin corresponds to the condition of independence of the main result (on the linear instability of the HP flow when Re > Rethmin) from the procedure of averaging used in the Galerkin approximation. Thus, we obtain the possible natural mechanism for the blood swirling flows formations observed in the aorta and the large blood vessels.
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Статья научная
Aims Problems of validation and verification are very critical in medicine. The absence of adequate models describing biophysical processes in the organism leads to using only practical evidence for these purposes that hinders innovations. But advances in medicine require new effective ways to solve these problems. Cardiometry as a new field in cardiology offers a new philosophy of validation and verification based on the classical proof theory borrowed from natural sciences. The aim hereof is to provide a new methodology for validation and verification for cardiovascular diagnostics. Materials and methods Axiomatic concepts based on new laws and rules allow applying direct and indirect methods of proof for validation and verification in medicine. Results The formulated laws of cardiometry provide reliable tools for verification of the correspondence between the cardiac signals and the real biophysical processes in the cardiovascular system. Conclusion The proposed methodology for verification of the correspondence between the ECG shapes and the relevant biophysical processes has been successfully developed exclusively as a result of creation of the comprehensive theory of cardiac cycle phase analysis being the basis of cardiometry...
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Статья научная
The article presents experimental results indicating the high efficiency of using in instrumental cognitive science some sand patterns on light tablets, created by respondents as illustrations of their problems, and possible ways to solve them. It is shown that the creation of such stimuli is less laborintensive compared to the use of other types of multimodal game modeling for the same purposes, and it is noted that this procedure causes less resistance by respondents to the upcoming instrumental diagnostics and may well serve as an operational means for conducting largescale studies of cognitive processes, during which the subjects will have to set semantic priorities and make vital decisions.
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Noninvasive investigation of the body functional state during night sleep in microgravity
Отчет
The Sonocard experiment purpose was a noninvasive physiological signal recording from sleeping humans. In 2007-2012 the experiment was made by 22 Russian members of 17 missions to the International space station. Of the overall 302 experimental sessions 47 were performed pre, 215 in and 40 after flight. The seismographic technique was used to pick up cosmonaut’s body microoscillations induced by cardiac beats, respiration and motor activity. The flight Sonocard model is a midget device fitting into the T-shirt pocket. Heart rate variability analysis (HRV) was the major method of securing conclusive evidence on stress level and blood circulation autonomic regulation. We were first to trace reorganization of the autonomic regulation at the night time on different phases of long-duration space mission and pioneered a systematic investigation of the human body functional state during sleep. It was shown that in the absence of work loads and emotional stresses the central mechanisms of circulation regulation tend to increase their activities...
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Novel formula to measure mean pulmonary artery pressure
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Mean Pulmonary Arterial Pressure (MPAP) is an important parameter in evaluation of patients with pulmonary hypertension. The aim of this study is to correlate a new formula using non-invasive blood pressure and Bernoulli’s right ventricle systolic pressure (RVSP) with invasive method. To archive the objectives, we enrolled 143 patients with suspected pulmonary hypertension from January 2015 till January 2016; all patients underwent right heart catheter evaluation and simultaneously RVSP by transthoracic echocardiography and non-invasive blood pressure to calculate MPAP by the formula MPAP = Pulse Pressure / (Mean Arterial Pressure/RVSP); and the results were compared using the Pearson’s simple-linear correlation method. We found a significant association between invasive and equation results with a Pearson’s correlation of 0,872 with a confidence interval from 0,795 to 0,921; sensitivity was 1,538% with a 95% confidence of interval (CI) from 0,038% to 8,276%, and Specificity was 100% with 95% CI from 94,48% to 100%. Our results suggest that the new formula have a good correlation estimating MPAP compared with invasive right heart catheterization method.
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Статья научная
Based on the results of our own research, examination of scientific dossier materials and reference literature data, it was established that dry powder Mungoltin made from the shoots of mung beans produced by Oriona-Scorpion LLC (Uzbekistan) contains a sufficient amount of protein, minerals, vitamins and dietary fiber, does not have a negative impact on the health status of experimental animals and does not result in functional and material cumulation. Acute systemic toxicity testing with intragastric administration of Mungoltin was carried out in 18 adult white male rats. Animals were divided into 4 groups. The animals of the first group received a nutrition dose of 5000 mg/ kg; the white rats of the second group were administered with a dose of 7500 mg/kg, and the rodents in the third group were given a dose of 10000 mg/kg, respectively. The animals in group 4 (the reference group) received distilled water. Upon a prolonged intragastric exposure to Mungoltin, no changes in biochemical parameters were detected. The activity indicators of alkaline phosphatase, trans-aminase enzymes and total protein in the blood serum did not differ significantly from those found in the reference group. Therefore, using Mungoltin will not cause a cytotoxic effect in relation to normal highly proliferating cells in an organism. The results of histomorphological studies of tissues of internal organs upon intragastric administration of Mungoltin within 30 days confirm the absence of toxic effects. According to toxicity parameters under the conditions of the above acute experiments, Mungoltin can be attributed to class 5 practically as a non-toxic substance.
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Статья научная
Aims Cardiac allograft vasculopathy (CAV) accounts for major morbidity and mortality late in the heart transplant (HTx) history. The role of antibodies (Abs) directed against human leukocyte antigens (HLA) and non-HLA antigens in the pathogenesis of CAV are still under investigation. Materials and methods Sera of 116 long-term HTx recipients with CAV (n=46) and without CAV (n=70) were analysed by (1) Luminex for Abs against both HLA classes and major histocompatibility complex class I-related chain A (MICA), and by (2) ELISA for Abs against angiotensin-type-1-receptor (AT1R) or endothelin-receptor-A (ETAR). Cellular rejection by endomyocardial biopsies and immunosuppressive drug therapy were analysed, too. Results HTx recipients developed higher levels of non-HLA-Abs than of Abs against HLA. CAV appeared more frequently in recipients with non-HLA-Abs (38.3% AT1R; 44.1% ETAR; 13.0% MICA) than in recipients with HLA-Abs (8.7% HLA class I; 8.7% HLA class II). Recipients with non-HLA-Abs developed CAV earlier (73.7±47.4months) than recipients without Abs (85.5±50.6months). Conclusion Occurrence of HLA-Abs and non-HLA-Abs contribute to CAV after HTx. Non-HLA-Abs were connected to an earlier and higher incidence of CAV. Recipients with subclinical cellular rejections and AT1R-Abs and ETAR-Abs as well as recipients with certain donor specific-Abs again HLA and MICA specifities are at risk to develop CAV.
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Статья
Giving an additional specific antitumor activity to biomaterials used to provide the local release of medical drugs into the bone defect in oncology, i.e. their functionalization is a promising, sought-after area in the modern biomaterials’ science
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Отчет
It is shown that initiated by action of molecular viscosity impulse flow, directed usually from the moving fluid to limiting it solid surface, can, under certain conditions, turn to zero and get negative values in the case of non-stationary flow caused by alternating in time longitudinal (along the pipe axis) pressure gradient. It is noted that this non-equilibrium mechanism of negative friction resistance in the similar case of pulsating blood flow in the blood vessels, in addition to the stable to turbulent disturbances swirled blood flow structure providing, can also constitute hydro-mechanical basis of the observed but not explained yet paradoxically high energy effectiveness of the normal functioning of the cardiovascular system (CVS). We consider respective mechanism of affecting on the stability of the normal work of CVS by environmental variable factors using shifting of hydro-dynamic mode with negative resistance realization range boundaries and variation of linear hydrodynamic instability leading to the structurally stable swirled blood flow organization.
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Статья научная
Aims A shortcoming common to all existing designs of mechanical cardiac valve prostheses is an increased trombogenicity caused, among other factors, by the lack of hydrodynamic compatibility between the luminal part of the prosthesis and the patterned blood flow. The aim of the study is to design and test our new mechanical aortic valve prosthesis to exclude life-long anticoagulation treatment. Materials and methods Standard hydrodynamic tests of the new prosthetic valve have been carried out for comparing with the other existing valve designs. A new method for the heart valve prosthesis testing in a tornado-like flow has been developed. The valve function has been verified in a swine excluding the anticoagulation treatment during the period of time exceeding six months. Results The significant advantage of the new prosthesis in the standard hydrodynamic tests has been demonstrated. The tests in the tornado-like flow have shown that only this prosthesis allows maintaining the pattern, the head and flow rate characteristics of the tornado-like jet...
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PCI VS CABG for patients with CTO: contemporary techniques and outcome-single center experience
Статья научная
CTOs are common findings on coronary arteriograms [1]. CTOs were defined as 100% coronary occlusion present for at least three months and found in almost 20% of all angiograms of patients with angina. The choice of therapy for patients undergoing coronary angiography and found to have CTOs was studied in The Canadian Multicenter Chronic Total Occlusions Registry [2]. Almost half the patients with CTOs were treated medically, and 25% underwent CABG (CTOs bypassed in 88%). PCI was performed in 30%, with a 70% success rate. While more patients with CTOs have historically been treated with CABG than PCI, technical advancements in PCI of CTOs may be expected to drive more patients with CTOs towards being treated with PCI [3].
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PDX model of BC in the study of plasticity of tumor cells in the process of metastasizing
Статья
Introduction. Mouse models using primary patient’s tumors (patient-derived xenograft, PDX) are an effective tool for studying the mechanisms of metastasizing. Tumor plasticity, i.e. the phenomenon of cell phenotype change in response to dynamic microenvironmental conditions is one of the key processes basic to metastasizing. The aim is to study the plasticity of tumor cells in metastasizing using the PDX model of breast cancer as an exemplary case. Materials and methods. Balb/c nude mice (♀, 8 weeks) were used to develop a xenograft model. In the 1st experiment, a suspension of primary tumor cells obtained from the surgical material of breast cancer was injected subcutaneously into the back area with the DMEM medium and Matrigel in a volume of 100 μl. In the 2nd experiment, a fragment of the primary tumor was implanted into the mammary gland area with suturing; after the formation of the vascular network, it was removed. Phenotyping was performed by flow cytometry (NovoCyte 3000 ACEA Biosciences, Agilent, USA) using antibodies to CD45, EpCam, CK7/8, CD44, CD24, N-cadherin.
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Paroxysmal atrial fibrillation in 5 months old Afro-Caribbean
Отчет
Congenital paroxysmal Atrial Fibrillation in infants is a rare occurrence requiring a high index of suspicion. The majority have a Pre-excitation syndrome which may be concealed. It may be associated with specific structural congenital cardiac lesions. This Index case had only paroxysmal atrial tachyarrhythmia with no predisposing condition that subsided spontaneously and is the first case documented in an Afro-Caribbean infant.
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Part ii: old mathematics for the novel applied problems of cardiometry
Статья научная
Aims This paper describes a novel approach to the analysis of electrocardiographic data based on the consideration of the repetitive P, Q, R, S, T sequences as cyclic codes. In Part I we introduce a principle similar to the syndrome decoding using the control numbers, which allows correcting the noise combinations. Materials and methods We propose to apply the burst-error-correcting algorithms for automatic detection of the ECG artifacts and the functional abnormalities, including those compared to the reference model. Our approach is compared to the symbolic dynamics methods in cardiology practice. During the automated search of the code components (i.e. point values and spectral ranges one-to-one corresponding to P, Q, R, S, T) considered in Part II, the authors apply the Lomb-Scargle periodogram method with the phase control which allows to determine the code components not only from the main harmonics, but also using the sidebands, avoiding the phase errors. Results The results of the method testing on rats with the heart failure using a simplified telemetric recording from the implantable chips are given in Part III...
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Статья научная
Aim Our aim was to study pathogenetically significant markers of sclerosing of hemangiomas in infants upon their exposure to optical radiation in the infrared region of the spectrum by analyzing thermog-raphy and morphology examination results. Materials and methods The basis for the thermographic study was our observation for 200 patients (birth to age 1), who re-ceived the hemangioma treatment in 2014-2016. We investigated thermograms of each vascular tumor in infants both before and after the treatment conducted with the use of the infrared themog-raphy (IRT) method. An IRT session was carried out upon a calm, quiet staying of an undressed in-fant in a room at an ambient temperature of 22°С and humidity of 0,009-0,012 kg/m3. To record heat fields in correspondence with the actual heat state of the tumor areas under studies, we used our thermo-vision device RADUGA-6 manufactured by AOMZ. The IRT data were compared with those obtained in ultrasound examinations. Diagnostic indicators of sclerosing, upon testing blood serum specimens, taken from 5 practically healthy and 25 hemangioma-affected children, were ana-lyzed with the use of the cuneiform dehydration technique...
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Pathogenetic substantiation for anti-tumor effectiveness of experimental electromagnetic therapy
Статья научная
Aim The objectives to be pursued by our studies are to assess some effects made by experimental actions of ultra-low frequencies electromagnetic field (ULF EMF) in combination with the SCENAR therapy on morphological changes in lung tissues and the regulation structures considering tumor growth dynamics. Materials and methods We investigated sex hormone and prolactin concentrations in 156 male rates of outbred strains in the tumor growth dynamics in tissues of the lungs and the hypophysis, and we also studied morphological changes in the lung tissue. All animals were divided into two groups: the reference group, covering the rodents not affected by any exposures, and the experimental group of the rats, who were subjected to ULF EMF exposure in combination with the SCENAR therapy. Both therapeutic exposures were applied upon expiration of 1 week after tumor cell inoculation in a lung. Results The applied combination of the experimental therapy, involving the central and local electromagnetic actions, has resulted in the reliably established prolongation of life spans in tumor-bearing animals as well as in the negative dynamics in tumor growing; it has produced effects both on the hormonal homeostasis subsystems: the hypophisis and the lung tissue affected by the cancer tumor...
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Статья
At present, the incidence of cancer tends to dramatically increase, and the existing advanced methods of cancer treatment are not always effective [1]. In addition, the disadvantages of the antitumor drugs used are their toxic effect made on the intact organs and tissues of the body, as well as the development of tumor resistance to them [2]. All this makes it necessary to search for new, safer and more effective drugs. In this case, plant-derived medicines have minimal side effects, so they are given special attention today. Plant-based drugs can be used both for the treatment of tumors as monotherapy and also in combination treatment to protect normal cells (including bone marrow stem cells) in a standard course of chemotherapy and radiation therapy [1,2, 3]. According to some researchers, the most promising group of this sort of medical drugs are flavonoids, since they produce the greatest number of biological effects, which favorably influence outcomes of treatment of neoplasms
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Статья
Improving the survival of cancer patients contributes to a growing number of patients with chronic comorbidities, including diabetes mellitus (DM). Moreover, higher risk of cancer development in patients with DM and poor prognosis determine the importance of studying the mechanisms mediating the effect of altered glucose metabolism made on the growth and metastasis of malignant tumors [3,4]. The polyetiology of both pathologies and the presence of research studies that do not confirm a direct relationship between DM and the development of malignant neoplasms indicate the complex nature of their relationship with the possible context-dependent regulation of many cellular processes associated with carcinogenesis and the development of DM [1,2]. An important role in the processes of the regulation is played by an imbalance in the system of sex hormones.
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Статья научная
In order to reveal the functional interrelationships of the main physiological characteristics of the organism with the external environment exogenous abiotic factors, as well as the evaluation of the magnetic field factor effect on the morphofunctional status main characteristics, 18 healthy men aged 25-49 years old, residents of the North-East of Russia (Magadan) were examined. Parameters of the cardiovascular system, external respiration and gas exchange, as well as heart rate variability were studied. Environmental factors, such as air temperature, wind speed, air humidity, atmospheric pressure and K-index were separately analyzed. Identified were different types of responses by human organisms to the influence of environmental abiotic factors, depending on the initial vegetative tone of the examinees. Thus, the individual profile of the subject with a sympathotonic type of autonomic regulation was characterized by a pronounced dynamics of the studied indicators in response to the influence of environmental factors...
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