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1.
Nature ; 607(7920): 682-686, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35896644

RESUMO

Cryptographic key exchange protocols traditionally rely on computational conjectures such as the hardness of prime factorization1 to provide security against eavesdropping attacks. Remarkably, quantum key distribution protocols such as the Bennett-Brassard scheme2 provide information-theoretic security against such attacks, a much stronger form of security unreachable by classical means. However, quantum protocols realized so far are subject to a new class of attacks exploiting a mismatch between the quantum states or measurements implemented and their theoretical modelling, as demonstrated in numerous experiments3-6. Here we present the experimental realization of a complete quantum key distribution protocol immune to these vulnerabilities, following Ekert's pioneering proposal7 to use entanglement to bound an adversary's information from Bell's theorem8. By combining theoretical developments with an improved optical fibre link generating entanglement between two trapped-ion qubits, we obtain 95,628 key bits with device-independent security9-12 from 1.5 million Bell pairs created during eight hours of run time. We take steps to ensure that information on the measurement results is inaccessible to an eavesdropper. These measurements are performed without space-like separation. Our result shows that provably secure cryptography under general assumptions is possible with real-world devices, and paves the way for further quantum information applications based on the device-independence principle.

2.
Vestn Otorinolaringol ; 89(2): 52-58, 2024.
Artigo em Russo | MEDLINE | ID: mdl-38805464

RESUMO

The results of a prospective open cohort study of the use of platelet-rich plasma (platelet-rich plasma - PRP) in patients with chronic pharyngitis during the exacerbation of the disease are presented. OBJECTIVE: To evaluate the clinical efficacy of autologous PRP in the treatment of chronic pharyngitis. MATERIAL AND METHODS: Autologous PRP was injected into the posterior pharyngeal wall as a course of endopharyngeal blockages as part of the complex therapy of chronic pharyngitis. Patients in the control group received standard therapy, without the use of autologous PRP. The effectiveness of the studied technique was evaluated by statistical analysis of the intensity of symptoms of the disease, determined by patients throughout the entire period of treatment in the patient's diary, as well as by analyzing data from mass spectrometry of microbial markers and bacteriological examination of the pharyngeal mucosa, collected at the beginning of the study and 14 days after completion of the course of therapy. CONCLUSION: The use of a course of endopharyngeal blockades with autologous platelet-rich plasma as part of the complex therapy of chronic pharyngitis, according to our estimates, provides a significant effect in the form of higher rates of reduction in the severity of symptoms of the disease, a significant reduction in the number of microorganisms deviating from the reference values (by 2 times or more), a decrease in the duration of the disease compared with the control group.


Assuntos
Faringite , Plasma Rico em Plaquetas , Humanos , Faringite/terapia , Faringite/microbiologia , Feminino , Masculino , Adulto , Doença Crônica , Resultado do Tratamento , Pessoa de Meia-Idade , Estudos Prospectivos , Transfusão de Sangue Autóloga/métodos
3.
Khirurgiia (Mosk) ; (12): 52-58, 2023.
Artigo em Russo | MEDLINE | ID: mdl-38088841

RESUMO

OBJECTIVE: To analyze the results of simultaneous surgical treatment of sternomediastinitis compared to stage-by-stage approach. MATERIAL AND METHODS: The study included 27 patients between October 2022 and March 2023. All patients underwent heart surgery through median sternotomy. There were 11 (40.7%) women and 16 (59.3%) men. Mean age of patients was 68.4±9.8 years. All patients were divided into 2 groups: 12 patients underwent partial necrectomy and vacuum wound therapy (or long-term dressings) before surgery (group 1), 15 patients underwent surgery without prior conservative treatment (group 2). RESULTS: The most common causative agent of infection was staphylococcus (48.1%). In all patients, we found histological signs of osteomyelitis. Preoperative clinical status was similar in both groups. There were differences in the following indicators: C-reactive protein upon admission - 74.9±18.6 versus 94.8±23.8 mg/l, procalcitonin - 0.13 [0.02; 1.43] versus 0.21 [0.02; 0.94] ng/ml. Postoperative outcomes were similar in both groups. Mortality was 8.3% (n=1) and 13.3% (n=2), respectively. CONCLUSION: Simultaneous combined surgical treatment (sequestrectomy + muscle flap grafting) demonstrates optimal results in the treatment of sternomediastinitis.


Assuntos
Procedimentos de Cirurgia Plástica , Infecção da Ferida Cirúrgica , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Infecção da Ferida Cirúrgica/etiologia , Esterno/cirurgia , Esterno/patologia , Retalhos Cirúrgicos , Esternotomia/efeitos adversos , Resultado do Tratamento , Estudos Retrospectivos
4.
Adv Gerontol ; 34(6): 870-878, 2021.
Artigo em Russo | MEDLINE | ID: mdl-35152603

RESUMO

The article describes the results of using the method of arterial piezopulsometry for non-invasive assessment of the functional state and physiological mechanisms of autonomous regulation of the cardiovascular system (CVS) in an elderly person with acute pain associated with unexpected physical trauma. On the first day, such an effect caused a negative stress reaction in the muscle effectors (ME) of the CVS, provoking an abnormal increase and acceleration of the contractility of the left ventricular myocardium. Analysis of the arterial blood pressure (PP) pulse wave graphs showed that the maximum rate of PP growth - VmaxPP, which reflects myocardial contractility, increased from 625±74 before injury to 2 117±173 mm Hg/s after injury, distorting the contour of the normal PP waveform. The reason for this growth could be the rapid cumulative effect of transmitters of the neuroendocrine sympathoadrenal system on adrenergic receptors (AR) of cardiomyocytes (CM). The results of the spectral analysis of the variability of the parameters of the PP waves confirmed this possibility. It was shown that under stress, norepinephrine from activated sympathetic efferents is added to the already increased content of humoral catecholamines in the extracellular environment of the myocardium near the AR of the CM, which is characteristic of the elderly. At the same time, the activity of parasympathetic efferents, releasing acetylcholine, which inhibits the contractile reaction of the myocardium and, thereby, performs a restraining cardioprotective function, significantly increases. A personalized approach was used for piezopulsometric study of the mechanisms of autonomous regulation of ME CVS under specific conditions of stress.


Assuntos
Sistema Nervoso Autônomo , Miocárdio , Idoso , Pressão Sanguínea , Catecolaminas , Frequência Cardíaca , Humanos , Norepinefrina
5.
Kardiologiia ; 61(6): 41-51, 2021 Jul 01.
Artigo em Russo, Inglês | MEDLINE | ID: mdl-34311687

RESUMO

Aim      To study features of diagnosis and treatment of acute myocardial infarction (AMI) in Russian hospitals, results of the treatment, and early and late outcomes (6 and 12 months after AMI diagnosis); to evaluate the consistence of the treatment with clinical guidelines; and to evaluate patients' compliance with the treatment.Material and methods  The program was designed for 3 years, including 24 months for recruitment of patients to the study. The study will include 10, 000 patients hospitalized with a confirmed diagnosis (I21 according to ICD-10) of ST segment elevation acute myocardial infarction (MI) (STEMI) or non-ST segment elevation MI (NSTEMI) based on criteria of the European Society of Cardiology Guidelines on Forth Universal Definition of Myocardial Infarction (2018). The follow-up period was divided into three stages: observation during the stay in the hospital and at 6 and 12 months following inclusion into the registry. The primary endpoint included cardiac death, nonfatal MI during the hospitalization and after one-year follow-up. Secondary endpoints were 6-months and one-year incidence of repeated MI, heart failure, ischemic stroke, clinically significant hemorrhage, unscheduled revascularization after discharge from the hospital, and the proportion of patients who continue on statins, antiplatelet drugs, and drugs of other groups for 6 months and 1 year.Results The inclusion of patients into the registry started in 2020 and will continue for 24 months. By the time of the article publication (June, 2021), more than 2,000 patients will be included.Conclusion      REGION-MI (Russian rEGIstry Of acute myocardial iNfarction) is a multicenter, retrospective and prospective observational cohort study that excludes any interference with the clinical practice. Results of the registry will help to analyze a real picture of medical care provided to patients with myocardial infarction and to schedule ways to improve the situation.


Assuntos
Infarto do Miocárdio , Humanos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/terapia , Estudos Prospectivos , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Federação Russa/epidemiologia , Fatores de Tempo , Resultado do Tratamento
6.
Angew Chem Int Ed Engl ; 60(12): 6791-6798, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33340439

RESUMO

Hyperpolarization-enhanced magnetic resonance imaging can be used to study biomolecular processes in the body, but typically requires nuclei such as 13 C, 15 N, or 129 Xe due to their long spin-polarization lifetimes and the absence of a proton-background signal from water and fat in the images. Here we present a novel type of 1 H imaging, in which hyperpolarized spin order is locked in a nonmagnetic long-lived correlated (singlet) state, and is only liberated for imaging by a specific biochemical reaction. In this work we produce hyperpolarized fumarate via chemical reaction of a precursor molecule with para-enriched hydrogen gas, and the proton singlet order in fumarate is released as antiphase NMR signals by enzymatic conversion to malate in D2 O. Using this model system we show two pulse sequences to rephase the NMR signals for imaging and suppress the background signals from water. The hyperpolarization-enhanced 1 H-imaging modality presented here can allow for hyperpolarized imaging without the need for low-abundance, low-sensitivity heteronuclei.

7.
Adv Gerontol ; 33(1): 74-81, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32362087

RESUMO

Using the method of arterial piezopulsometry, statistical and spectral analyzes of variable parameters (VmaxPP and TNN) of pulse waves of blood pressure in patients aged 18 to 85 years were performed. The individual characteristics of the autonomous (vegetative and neuroendocrine) regulation of the muscular effectors (ME) of the cardiovascular system (CVS) in an elderly man (75 years old) and a young woman (20 years old) were estimated with high accuracy. These data, as well as the results of a comparative study of patients of different ages, made it possible to identify a certain pattern of directed change in the sympathoadrenal regulation of ME CVS in human ontogenesis. It is concluded that in the course of their lives, people undergo a restructuring of the physiological mechanism of the autonomous regulation of their ME CVS, aimed at replacing short-term sympathetic regulation in young people with more effective and more stable regulation by humoral catecholamines in elderly.


Assuntos
Envelhecimento , Sistema Nervoso Autônomo , Sistema Cardiovascular , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
Phys Chem Chem Phys ; 19(5): 3777-3781, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28098267

RESUMO

To understand the dynamic nuclear polarization (DNP) enhancements of biradical polarizing agents, the magnetic resonance parameters need to be known. We describe a tailored EPR approach to accurately determine electron spin-spin coupling parameters using a combination of standard (9 GHz), high (95 GHz) and ultra-high (275 GHz) frequency EPR. Comparing liquid- and frozen-solution continuous-wave EPR spectra provides accurate anisotropic dipolar interaction D and isotropic exchange interaction J parameters of the DNP biradical AMUPol. We found that D was larger by as much as 30% compared to earlier estimates, and that J is 43 MHz, whereas before it was considered to be negligible. With the refined data, quantum mechanical calculations confirm that an increase in dipolar electron-electron couplings leads to higher cross-effect DNP efficiencies. Moreover, the DNP calculations qualitatively reproduce the difference of TOTAPOL and AMUPol DNP efficiencies found experimentally and suggest that AMUPol is particularly effective in improving the DNP efficiency at magnetic fields higher than 500 MHz. The multi-frequency EPR approach will aid in predicting the optimal structures for future DNP agents.

10.
Bull Exp Biol Med ; 160(4): 407-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26902347

RESUMO

Gradual cooling of homeothermic organisms is followed by slowing and arrest of breathing and heart contractions. During deep cooling, even relatively slight artificial ventilation decreases the lower temperature limit of life (by 4.5-5°C) and provides minimum oxygen supply to the heart and whole body. This allows us to restore cardiovascular function and prevent animal death after lethal cooling without eternal warming.


Assuntos
Temperatura Corporal/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Hipotermia Induzida/métodos , Contração Miocárdica/fisiologia , Respiração Artificial/métodos , Animais , Regulação da Temperatura Corporal , Temperatura Baixa , Masculino , Ratos
11.
Voen Med Zh ; 337(12): 28-35, 2016 12.
Artigo em Russo | MEDLINE | ID: mdl-30592820

RESUMO

Organisation of medical care to military personnel with viral hepatitis A during the local armed conflicts. The article provides an analysis of medical care organisation system to patients with viral hepatitis A during conducting counterterror operations on the North Caucasus (1994-1996 and 1999-2002). The authors provided information on the main problems of medical support in modern local armed conflicts and shortcomings of organization of medical care to patients with viral hepatitis A in the following conditions: multistage, discrepancy between calculation of forces and facilities and character of military conditions, shortcoming of staff structure of medicalfacilities, inappropriate level ofproficiency ofphysicians of infectious profile and absence of regulations, concerning the use for equipment of infectious hospitals. 'Possible -ways for resolving these problems are showed.


Assuntos
Atenção à Saúde , Hepatite A , Medicina Militar , Militares , Atenção à Saúde/métodos , Atenção à Saúde/organização & administração , Atenção à Saúde/normas , Feminino , Hepatite A/epidemiologia , Hepatite A/terapia , Humanos , Masculino , Medicina Militar/métodos , Medicina Militar/organização & administração , Medicina Militar/normas , Estudos Retrospectivos
12.
Voen Med Zh ; 336(1): 29-35, 2015 Jan.
Artigo em Russo | MEDLINE | ID: mdl-25916034

RESUMO

Late diagnosis of meningococcal disease leads to high mortality. Early diagnosis of its generalized forms plays a crucial role in the pre-hospital phase and mainly based on the clinical picture of the disease. In most cases, pre-hospital typical mistake is late diagnosis of meningococcal disease: We propose an algorithm of early diagnosis of generalized forms of the disease in order to reduce the number of diagnostic errors. Proper and timely diagnosis will enable the physician pre-hospital fully implement measures to provide emergency and urgent care in generalized meningococcal infection, leading to. a more.favourable course and a significant improvement in the outcomes of the disease in the course of further hospital treatment.


Assuntos
Erros de Diagnóstico/prevenção & controle , Serviços Médicos de Emergência/métodos , Infecções Meningocócicas/diagnóstico , Medicina Militar/métodos , Militares , Adolescente , Algoritmos , Tomada de Decisões , Diagnóstico Diferencial , Erros de Diagnóstico/estatística & dados numéricos , Diagnóstico Precoce , Humanos , Masculino , Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/terapia , Militares/estatística & dados numéricos
13.
J Gen Virol ; 95(Pt 7): 1415-1429, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24722679

RESUMO

Potyviruses represent one of the most economically important and widely distributed groups of plant viruses. Despite considerable progress towards understanding the cellular and molecular basis of their pathogenicity, many questions remain about the mechanisms by which potyviruses suppress host defences and create an optimal intracellular environment for viral translation, replication, assembly and spread. The review focuses on the multifunctional roles of potyviral proteins and their interplay with various host factors in different compartments of the infected cell. We place special emphasis on the recently discovered and currently putative mechanisms by which potyviruses subvert the normal functions of different cellular organelles in order to establish an efficient and productive infection.


Assuntos
Interações Hospedeiro-Patógeno , Doenças das Plantas/virologia , Potyvirus/fisiologia , Proteínas Virais/metabolismo
14.
Vestn Ross Akad Med Nauk ; (1-2): 57-63, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25055562

RESUMO

In this paper long known problems of microcirculation are shown, which were solved only during the last 40 years. They are concerned with the velocity and character of the capillary blood flow, the regulation of the capillary blood flow, the role of various vessels in the oxygen transport, the role of leukocytes in physiology and pathology of the capillary blood flow, with the special features of the function of lungs in supplying the whole organism with oxygen and with bioenergetic laws in the development of an organism adaptation to hypoxia. Here we considered a number of the most important medical problems of microcirculation and hypoxic syndrome. A relatively new factor in the capillary circulation is the fact that in the brain and heart capillaries there are sites with pO2 close to zero. They show that the capillary circulation has no central nervous regulation of the blood flow. The blood flow in these organs obeys only occasional oscillations. The new fact is that Krogh's rule about metabolism and oxygen exchange occurring only in the capillaries is abandoned. It is shown that almost 30% of consumed oxygen is delivered to the brain via arterioles, which changes our relation to the capillary circulation as a unique mechanism of the tissue supply with oxygen. The new fact is also the mass adhesion of leukocytes to the walls of microvessels, which results in the occlusion of the vessels followed by the development of the heart and brain ischemia. It was shown for the first time that contrary to previous ideas the alveoli in the lungs are supplied with blood from a powerful network of large microvessels from 20 to 50 microm in diameter rather than from thin arterioles. They make possible the passage of 6-121 of the blood in the norm and during stressed muscle activity--up to 18-231 of blood per minute. The principle is substantiated that during hypoxia only normal supply of an organism with oxygen may result in a complete adaptation of an organism to the deficit of oxygen.


Assuntos
Capilares/fisiologia , Hipóxia/metabolismo , Microcirculação/fisiologia , Adaptação Fisiológica , Velocidade do Fluxo Sanguíneo , Encéfalo/irrigação sanguínea , Adesão Celular , Metabolismo Energético , Humanos , Leucócitos/citologia , Leucócitos/fisiologia , Pulmão/irrigação sanguínea , Músculo Esquelético/irrigação sanguínea , Oxigênio/sangue
15.
Vestn Ross Akad Med Nauk ; (7-8): 5-9, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25562998

RESUMO

BACKGROUND: The arrest of respiration during deep hypothermia means death, though at a low temperature the heart may rhythmically contract for 30-40 minutes more. The attempts of rewarming only shorten the time before the heart arrest. Calcium ions (Ca2+) are believed to accumulate in the nervous cells in cold. An excess of these ions inhibits the metabolism. Moreover it stimulates the cell proteases, which destroy the cell membranes. AIM: The aim of the study was to make the the attempts to develop the methods of stimulating the respiration and heart without rewarming the body. MATERIALS AND METHODS: The work was carried out on wite rats 250-320g in weight. We introduced disodium salt of ethylenediaminetetraacetic acid into the animals. The second method of blocking the mechanisms of the cold death was artificial respiration. RESULTS: Ethylenediaminetetraacetic acid reacts with calcium ions, decreases their quantity in the blood, and, consequently, in a complex manner in the cell protoplasm. Artificial respiration not only increases the flow of oxygen into an organism but also decreases the lowest temperature threshold of the cold death of an organism. CONCLUSION: A decrease in the surviving threshold by 1.5-1.8 degrees C is very important from the point of view of reanimation of an organism since to preserve life in the critical period of reanimation each 0.5 degrees C are important. Prolongation of minimal frequency of heart contractions and maintaining a minimal arterial blood pressure in an overcooled organism given the body temperature of 11-12.5 degrees C is a special problem of great interest associated with many physiological and biological parameters.


Assuntos
Cálcio/metabolismo , Reanimação Cardiopulmonar , Congelamento das Extremidades , Parada Cardíaca/prevenção & controle , Hipotermia/terapia , Consumo de Oxigênio/fisiologia , Animais , Reanimação Cardiopulmonar/efeitos adversos , Reanimação Cardiopulmonar/métodos , Temperatura Baixa , Modelos Animais de Doenças , Congelamento das Extremidades/etiologia , Congelamento das Extremidades/metabolismo , Congelamento das Extremidades/fisiopatologia , Parada Cardíaca/etiologia , Parada Cardíaca/metabolismo , Parada Cardíaca/fisiopatologia , Frequência Cardíaca , Hipotermia/complicações , Hipotermia/fisiopatologia , Masculino , Ratos , Respiração
16.
Zh Evol Biokhim Fiziol ; 50(1): 12-8, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25486800

RESUMO

The main direction of evolution of living organisms is development of the central nervous system and sense organ, an increase of energy exchange development of homoiothermia, development of the more and more complex forms of behavior, an increase in energy expenditure in connection with an increase of the organism activity, and development of adaptation to the habitat. Such fundamental processes were subjected and have been subjected to numerous studies and discussions. However, in different animals there exist different species peculiarities of evolution of physiological functions, from which finally formed are fundamental evolutionary processes. We studied some of these specific processes by dividing them into two categories. The first category is "Increase of efficiency of adaptation" in development of biological evolution. By this term we mean development of amazing by perfection specific physiological mechanisms of adaptive character. The second category is "Weakening of protective organism reactions". By this we understand disturbance of protective mechanisms of the organism immune system, discoordination of movement of leukocytes along microvessels, the absence of efficient collateral circulation in brain and in heart, etc.


Assuntos
Adaptação Fisiológica/genética , Metabolismo Energético , Evolução Molecular , Respiração , Animais
17.
Akush Ginekol (Sofiia) ; 53(8): 20-6, 2014.
Artigo em Búlgaro | MEDLINE | ID: mdl-25672086

RESUMO

AIM: Our aim was to evaluate and summarize our experience in surgical treatment for early ovarian cancer, the way and extend of metastases, as well as the need and effectiveness of applying radical pelvic and paraaortic lymph node dissection. We compared our results with the results of prominent clinics all over the world in this special field. MATERIAL AND METHODS: We researched retrospectively patients, operated for early ovarian cancer for 15 years period. We evaluated the use of lymph node dissection and the level of its radicality. Examining the volume and borders of the lymph node dissection we tried to sintesize the main practical conclusions and refferences, which can be applied practically by the colleagues working in gynaecological and oncogynaecological clinics in our country RESULTS: According to us and the most foreign authors the ovarian cancer, must be removed intact, and frozen section biopsy must be used. The surgical staging includes: total abdominal histerectomy, bilateral salpingooophorectomy and total pelvic and/or paraaortic lymph node dissection. The surgical staging in all patients is obligatory and includes: a) cytological examination of ascites. b) when ascites is absent--cytological smear. c) Examination of intraabdominal organs and surfaces. d) Biopsies are taken from all suspicious regions. e) The diaphragm is examined by biopsy and scraping. f) Infracolic omentectomy is performed. g) Retroperitoneal spaces are dissected and examined. h) The paraaortal area is examined. When enlarged lymph nodes are found--they are resected and examined. If enlarged paraaortal lymph nodes are found--total paraaortic lymph node dissection is performed. DISCUSSION: The extend of the lymph node dissection in early ovarian cancer is connected with better survical rate in these patients. CONCLUSIONS: The lymph node dissection helps for precise surgical staging in early ovarian cancer. The volume of the lymph node dissection is significant prognostic factor for better survical rate, as well as age, stage, histological type and the grade of the disease.


Assuntos
Excisão de Linfonodo/métodos , Linfonodos/patologia , Metástase Linfática/patologia , Estadiamento de Neoplasias/métodos , Neoplasias Ovarianas/patologia , Ovário/patologia , Feminino , Humanos , Linfonodos/cirurgia
18.
Patol Fiziol Eksp Ter ; (3): 32-6, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25536788

RESUMO

In experiments on rats studied influence of intravenous introduction NazdTA on respiratory function of rats after the full termination of breath at deep hypothermia. It is shown that such method without warming application it is possible to lower on 1.5-2.0 degrees C a temperature threshold of approach full a cold paralysis of respiratory function of an organism. It confirms the hypothesis put forward earlier about an important role of infringement of balance of ions of calcium in cytoplasm of cells in development of a pathology of an organism at deep hypothermia. The received results can be used at resuscitation of victims accidental hypothermia.


Assuntos
Ácido Edético/uso terapêutico , Hipotermia/tratamento farmacológico , Respiração/efeitos dos fármacos , Ressuscitação/métodos , Animais , Temperatura Corporal , Cálcio/metabolismo , Temperatura Baixa , Ácido Edético/farmacologia , Hipotermia/metabolismo , Hipotermia/fisiopatologia , Masculino , Ratos , Ratos Wistar
19.
Adv Exp Med Biol ; 756: 197-201, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22836636

RESUMO

In this study we investigated microcirculation in the lungs in their in situ physiological location inside the thorax. The study was performed with the use of a system of contact optics. A 'window', 4 × 4 mm in size, was made in thorax tissues and pleura of an anaesthetized rat. The lung collapsed and then was filled with oxygen or hypoxic gas mixture under the pressure of 10-15 cm H(2)O through a tracheostomic canula. This almost excluded the respiratory movements of the lung. Then, the lung was brought in contact with a lens (1.7 mm aperture). We showed that there is a whole system of wide microvessels (20-30 µm in diameter) which run between the alveoli; the finding contradicting the hitherto notion that each alveolus is supplied with blood via the thinnest (5-10 µm in diameter) lung arterioles. The microvessels we visualized surround each alveolus almost from all sides. In this way, each alveolus receives a maximum amount of blood. Such a structure of lung circulation accounts for a substantial blood flow through the lungs (up to 6 l per min in humans) and for a rapid saturation of the blood with oxygen (about 100 ml per second). The alveoli saturate the blood with oxygen and subsequently the microvessels form the lung veins entering the left auricle. The photographs and video films of the alveoli at a high magnification were presented, demonstrate the special features of the structure and circulation in the alveoli. The plausible mechanisms of rapid saturation of the blood with oxygen are discussed.


Assuntos
Pulmão/irrigação sanguínea , Microcirculação/fisiologia , Alvéolos Pulmonares/irrigação sanguínea , Circulação Pulmonar/fisiologia , Animais , Microvasos/fisiologia , Oxigênio/sangue , Ratos
20.
Bull Exp Biol Med ; 154(4): 411-4, 2013 Feb.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-23486567

RESUMO

Blood flow through the human lungs weighing 600 g is about 5 to 6 liters per minute. Blood capacity of human lung is about 500 ml. Therefore, 500 ml blood is oxygenated for 5 sec. Questions arise how such a large volume of blood passes through such a small mass of the lungs and what causes very rapid blood oxygenation. Since the structure of the lungs in mammals is almost the same, the work was carried out on rats (in rats 20-22 ml of blood per minute passes through the lungs weighing 1.5-2.0 g). Intensive blood circulation was proved to be linked with a large diameter pulmonary arterioles and high blood flow velocity in them. The oxygenation rate is explained by special structure of the alveoli and special blood flow conditions, which creates ideal conditions for oxygen diffusion.


Assuntos
Pulmão/fisiologia , Circulação Pulmonar/fisiologia , Animais , Masculino , Oxigênio/metabolismo , Alvéolos Pulmonares/fisiologia , Ratos , Ratos Wistar
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