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Starting from a classical Kröener-Rieder kinematic picture for plasticity, we derive a set of dynamical equations describing plastic flow in a Lagrangian formulation. Our derivation is a natural and straightforward extension of simple fluids, elastic, and viscous solids theories. These equations contain the Maxwell model as a special limit. This paper is inspired by the particularly important work of Langer and coworkers. We shall show that our equations bear some resemblance with the shear-transformation zones model developed by Langer and coworkers. We shall point out some important differences. We discuss some results of plasticity, which can be described by the present model. We exploit the model equations for the simple examples: straining of a slab and a rod. We find that necking manifests always itself (not as a result of instability), except if the very special constant-velocity stretching process is imposed.
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We consider a sharp interface kinetic model of phase transitions accompanied by elastic strain, together with its phase-field realization. Quantitative results for the steady-state growth of a new phase in a strip geometry are obtained, and different pattern formation processes in this system are investigated.
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We consider periodic domain structures which appear due to the magnetoelastic interaction if the antiferromagnetic crystal is attached to an elastic substrate. The peculiar behavior of such structures in an external magnetic field is discussed. In particular, we find the magnetic field dependence of the equilibrium period and the concentrations of different domains.
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We discuss the stick-slip motion of an elastic block sliding along a rigid substrate. We argue that for a given external shear stress this system shows a discontinuous nonequilibrium transition from a uniform stick state to uniform sliding at some critical stress which is nothing but the Griffith threshold for crack propagation. An inhomogeneous mode of sliding occurs when the driving velocity is prescribed instead of the external stress. A transition to homogeneous sliding occurs at a critical velocity, which is related to the critical stress. We solve the elastic problem for a steady-state motion of a periodic stick-slip pattern and derive equations of motion for the tip and resticking end of the slip pulses. In the slip regions we use the linear friction law and do not assume any intrinsic instabilities even at small sliding velocities. We find that, as in many other pattern forming system, the steady-state analysis itself does not select uniquely all the internal parameters of the pattern, especially the primary wavelength. Using some plausible analogy to first-order phase transitions we discuss a "soft" selection mechanism. This allows to estimate internal parameters such as crack velocities, primary wavelength and relative fraction of the slip phase as functions of the driving velocity. The relevance of our results to recent experiments is discussed.
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We studied effects of neonatal hepatocytes transplantation (NHT) on lipid metabolism and hemostasis in experimental hypercholesterolemia. A positive NHT influence on lipid metabolism, lipid peroxidation and hemostasis was established. The experimental data evidence for preferential influence of intrahepatic NHT on lipid metabolism and hemostasis compared to intravenous NHT.
Assuntos
Coagulação Sanguínea/fisiologia , Transplante de Células/métodos , Hepatócitos/transplante , Hipercolesterolemia/terapia , Metabolismo dos Lipídeos , Fígado/citologia , Animais , Modelos Animais de Doenças , Hipercolesterolemia/sangue , Hipercolesterolemia/metabolismo , Injeções Intravenosas , Coelhos , Transplante HomólogoRESUMO
The interaction between inclusions mediated by biological membranes undulations is analyzed. The interaction law is interpreted in terms of symmetries associated with inclusions. We show, in particular, that for a C3 and C3v symmetries the interaction law falls as 1/r3. We show that for completely isotropic inclusions, the dominant interaction vanishes to all orders, and the first contribution stems from the induced interaction which behaves as 1/r4. The same law holds for any other symmetry which is higher than C4. We introduce a straightforward method to compute these interactions. We point out important differences with results in the literature and explain the discrepancies.
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It is shown that the strain field of an edge dislocation in a smectic crystal must be described in the framework of nonlinear theory, even far away from the core region. We present an exact solution of this nonlinear problem. The result of the linear theory is recovered in the limit of large bending rigidity.
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Tumor necrosis factor-alpha (TNF) was shown to have an antiinfectious effect on murine and rat models of viral, bacterial and parasitic infections. The effective antiinfectious dose of TNF was determined to be 10(2)-10(3) U/kg body weight. TNF, interferon, and antibiotics were demonstrated to potentiate the antibacterial effect of each. Clinical trials of TNF in the treatment of slowly progressive, latent, and chronic infections and in the emergency prevention of acute infections are advisable.
Assuntos
Infecções Bacterianas/tratamento farmacológico , Doenças Parasitárias/tratamento farmacológico , Fator de Necrose Tumoral alfa/uso terapêutico , Viroses/tratamento farmacológico , Adjuvantes Imunológicos/uso terapêutico , Animais , Modelos Animais de Doenças , Seguimentos , Interferon Tipo I/uso terapêutico , Interferon alfa-2 , Interferon-alfa , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos CBA , Ratos , Proteínas Recombinantes , Resultado do TratamentoRESUMO
68 children aged 3-7 years, undergoing general sanative treatment in a bronchopulmonary sanatorium in the vicinity of Moscow between November 10 and December 29, 1990, were examined. During the stay of these children in the sanatorium cases of respiratory diseases, mainly of parainfluenza etiology, were registered, which was confirmed by serological laboratory studies. At this season no cases of Legionella and Mycoplasma infections were detected. The necessity of taking prophylactic measures with the use of reaferon and lysozyme in sanative groups of children in due time, starting from the first day of the formation of such group, was substantiated.
Assuntos
Estâncias para Tratamento de Saúde , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/prevenção & controle , Doença Aguda , Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Humanos , Infecções Respiratórias/imunologia , Estações do Ano , Estudos Soroepidemiológicos , U.R.S.S./epidemiologiaRESUMO
The results of the clinical trials of human recombinant interferon alpha-2 (reaferon) make it possible to come to the conclusion that the preparation is well-tolerated and produces a pronounced therapeutic effect in a number of viral and oncological diseases. The Pharmacological Committee of the USSR has recommended reaferon for use in acute hepatitis B, hairy cell leukemia, renal cancer at stage IV, disseminated sclerosis, ocular herpes. The use of reaferon has been found to be promising in the treatment of papillomatosis of the larynx, Kaposi's sarcoma, mycosis fungoides, chronic myeloleukemia.
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Interferon Tipo I/uso terapêutico , Ensaios Clínicos como Assunto/estatística & dados numéricos , Relação Dose-Resposta a Droga , Tolerância a Medicamentos , Humanos , Interferon Tipo I/administração & dosagem , Interferon Tipo I/efeitos adversos , Interferon alfa-2 , Interferon-alfa , Proteínas Recombinantes , U.R.S.S.Assuntos
Interferon Tipo I/farmacologia , Animais , Células Cultivadas/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Interferon Tipo I/análise , Interferon Tipo I/imunologia , Interferon Tipo I/toxicidade , Interferon alfa-2 , Interferon-alfa , Proteínas Recombinantes , Fatores de Tempo , U.R.S.S.RESUMO
The authors relate the results of a clinical study of the Soviet recombination alpha-interferon (reaferon) in 46 patients with chronic myeloleukemia at different stages of the disease. Reaferon is shown to be tolerated well, to have a low percentage of side effects in particular high temperature and allergic reactions, to possess no hepato-, nephro- and cardiotoxicity. It has been proved that in patients with chronic myeloleukemia reaferon produces an independent antiproliferative effect and is capable of controlling the leukemic process without chemotherapeutic drug (in the stable chronic phase of the disease). Doses and administration of reaferon for a long time are suggested in order to prolong the disease course.
Assuntos
Interferon Tipo I/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Crise Blástica/terapia , Terapia Combinada , Avaliação de Medicamentos , Feminino , Humanos , Interferon Tipo I/efeitos adversos , Interferon alfa-2 , Interferon-alfa , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Pessoa de Meia-Idade , Cromossomo Filadélfia , Proteínas Recombinantes , Fatores de TempoRESUMO
An analysis of 534 patients has shown that laparoscopy is a method of high diagnostic informative value. The correct diagnosis was made in 515 patients (96.4%). Diagnostic errors were noted in 19 patients (3.6%). The greatest problems appeared in diagnosing thrombosis of mesenterial vessels and acute appendicitis in cases with the retrocecal disposition of the vermiform process. Surgical operations under control of a laparoscope were fulfilled by strict indications. Good immediate results were obtained in 81.9% of the patients.
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Abdome Agudo/diagnóstico , Abdome Agudo/cirurgia , Adolescente , Adulto , Apendicite/diagnóstico , Colecistite/diagnóstico , Diagnóstico Diferencial , Erros de Diagnóstico , Feminino , Humanos , Obstrução Intestinal/diagnóstico , Cuidados Intraoperatórios , Laparoscopia , Masculino , Artérias Mesentéricas , Oclusão Vascular Mesentérica/diagnóstico , Pessoa de Meia-Idade , Pancreatite/diagnóstico , Úlcera Péptica Perfurada/diagnóstico , Trombose/diagnósticoAssuntos
Celulite (Flegmão)/diagnóstico , Enterite/diagnóstico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The ointment containing pig leukocytic interferon had a pronounced therapeutic effect in herpetic affections of the face skin and genitalia. It prevented eruption, shortened the period of its healing and eliminated subjective sensations. The therapeutic effect was observed in 265 (87.7 per cent) out of 302 patients with recurring Herpes simplex treated with ointment.
Assuntos
Herpes Simples/terapia , Interferon Tipo I/administração & dosagem , Adulto , Idoso , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pomadas , SuínosRESUMO
Production of different kinds of interferon in imported media (medium 199, Eagle's medium) greatly impedes the organization of large-scale interferon production in this country. The search for national substitutes of these media is important therefore. This paper deals with a comparative study of the use of national aminopeptide and hemohydrolysate preparations for interferon production. It was shown that substitution of serum with BAF in preparations of human and swine interferon increased their activity 2- and 4-fold, respectively, and the amount of protein was reduced 10-fold. Specimens of interferons produced with the addition of AP were less effective because the amount of protein increased 4-20-fold while the antiviral activity increased insignificantly. The most effective were interferon preparations obtained with hemohydrolysate medium. Their activity being similar, the amount of protein in interferon samples increased 11/2-2-fold only. Thus, aminopeptide and hemohydrolysate can effectively substitute medium 199 for production of leukocyte human and swine interferon.