ABSTRACT
Sound generation by a femtosecond laser pulse in a metal layer on a dielectric substrate is studied. The excitation of sound caused by the effect of the ponderomotive force, temperature gradients of electrons, and lattice is considered. A comparison is made of these generation mechanisms for various excitation conditions and frequencies of generated sound. It is shown that in the case when effective collision frequencies in the metal are low, sound generation dominates in the terahertz frequency range due to the ponderomotive effect of the laser pulse.
ABSTRACT
Nonlinear generation of the quasi-cylindrical and surface waves in terahertz frequency domain under exposure of a femtosecond laser pulse focused into a strip on a metal was studied. Competition between generated waves is determined by the value of the product of electron collision frequency and laser pulse duration. Comparison of magnetic field pulses of the quasi-cylindrical and surface waves generated on the surface is given for gold, silver, and aluminum. It is shown that far from the focusing strip the surface wave pulse contains oscillations arising due to frequency dispersion.
ABSTRACT
Electron microscopy revealed morphofunctional changes in mitochondria of rats under stress conditions. Reparative processes and pathomorphological changes were monitored. Heterogeneous ultrastructural changes in mitochondria were revealed.
Subject(s)
Mitochondria/ultrastructure , Stress, Psychological/physiopathology , Animals , Cerebellum/ultrastructure , Mitochondria/physiology , Motor Activity/physiology , Neurons/ultrastructure , Purkinje Cells/ultrastructure , RatsABSTRACT
In 1990, diphtheria re-emerged in Russia and during the following four-year period the resulting epidemic reached all the Newly Independent States (NIS) of the former Soviet Union. Several neighbouring countries of NIS, Norway included, have experienced sporadic imported cases. A sero-epidemiological study among children in Northern Norway and North-Western Russia was performed in order to evaluate protection against diphtheria and how differences in vaccination programmes affect immunity. A total of 664 sera, 400 from Norwegian and 264 from Russian children, were examined for antibodies against diphtheria, using an in vitro toxin neutralisation method. The Russian children studied had satisfactory protection in all age groups examined. The Norwegian children had poor protection against diphtheria from the age of 7 years until they received the booster dose at the age of 11. Therefore, a revision of the Norwegian vaccination programme, including a booster dose at school-entry age, seems warranted.
Subject(s)
Antibodies, Bacterial/blood , Diphtheria-Tetanus-Pertussis Vaccine/immunology , Diphtheria/immunology , Child , Child, Preschool , Diphtheria/epidemiology , Female , Humans , Immunization, Secondary , Infant , Male , Russia/epidemiology , Seroepidemiologic Studies , Sex Factors , VaccinationABSTRACT
A model of spinal pain syndrome induced by a generator of abnormally increased excitation in the system of dorsal horns of the spinal cord with penicillin was used to test the calcium channel blockers OF5015 and nimotop, as well as calcium gluconate for their effects. The drugs were administered orally, intraperitoneally, intracisternally and applied to the spinal cord in combination with penicillin which was used to induce the pain syndrome. The action of the agents were compared with that of analgin. OF5015 given in a dose orally was shown to attenuate the pain syndrome to a greater extent than analgin. Nimotop and calcium gluconate given orally or intrasystematically failed to affect the pain syndrome. When applied to the spinal cord, all the drugs substantially attenuated the pain syndrome or prevented its development.
Subject(s)
Calcium Channel Blockers/therapeutic use , Calcium Gluconate/therapeutic use , Pain/drug therapy , Spinal Cord/drug effects , Acute Disease , Animals , Dipyrone/therapeutic use , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Nimodipine/therapeutic use , Organic Chemicals , Pain/chemically induced , Penicillins , RatsABSTRACT
The utilization of glucose, NFA, triglycerides, cholesterol and alpha-lipoprotein cholesterol as well as the production of lactic acid were studied at different pH levels on the model of isolated lungs of the dog perfused in a special chamber maintaining the conditions close to physiological. The data obtained may be used for the assessment of lung metabolism under these conditions.
Subject(s)
Carbohydrate Metabolism , Lipid Metabolism , Lung/metabolism , Animals , Dogs , Energy Metabolism , Glucose/metabolism , Hydrogen-Ion Concentration , In Vitro Techniques , Lactates/metabolism , Partial Pressure , Perfusion/methodsABSTRACT
The oxygen-transport function of blood in hyperoxia and acute disturbances of the acid-alkali condition was studied in "oxygenator--desoxygenator" as a model. It has been established that in acidosis there occurs decreased intensity of glycolysis in erythrocytes, accumulation of 2,3 diphosphoglyceric acid which decreases affinity of hemoglobin for oxygen. It does not occur in alcalosis.
Subject(s)
Acid-Base Imbalance/blood , Acidosis, Respiratory/blood , Alkalosis, Respiratory/blood , Oxygen/blood , Acute Disease , Biological Transport , Carbon Dioxide/blood , Energy Metabolism , Erythrocytes/metabolism , Humans , Models, Structural , Oxyhemoglobins/metabolismSubject(s)
Plethysmography, Impedance , Thorax/blood supply , Animals , Dogs , Female , Humans , MaleABSTRACT
A model of acute respiratory insufficiency ARI was created in the experiments on 16 dogs by means of a valvular device furnishing a free inhalation and a limited expiration. The diaphragmatic oxigenator devised in VNIIP with an armoured diaphragm of "Sigma"--type was switched on at the height of ARI. 3 hours' perfusion corrected successfully the manifestation of hypercapnic hypoxia. The pulmonary function restored after the experiment.
Subject(s)
Oxygenators, Membrane , Respiratory Insufficiency/therapy , Acute Disease , Animals , Disease Models, Animal , Dogs , Hypercapnia/therapy , Hypoxia/therapy , Partial Pressure , Time FactorsSubject(s)
Lung Transplantation , Organ Preservation , Tissue Preservation , Humans , Hypothermia, Induced/methods , Ischemia/physiopathology , Lung/blood supply , Organ Preservation/methods , Perfusion/methods , Time Factors , Tissue Donors , Tissue Preservation/methods , Transplantation, HomologousSubject(s)
Plethysmography, Impedance/methods , Adolescent , Adult , Animals , Blood Flow Velocity , Dogs , Electric Conductivity , Electrodes , Hemorrhage/physiopathology , Humans , Lung/physiology , Middle Aged , Pulse , Regional Blood Flow , RespirationABSTRACT
The dynamics of acute lung edema development caused by injection of oleic acid into the right heart chambers was traced experimentally on dogs by means of impedance plethysmography. The most of information was collected with the help of electrodes applied to the chest. The development of acute lung edema was followed by decrease of the impedance respiratory undulations and by changes in their characteristics.
Subject(s)
Plethysmography, Impedance/methods , Pulmonary Edema/etiology , Acute Disease , Animals , Dogs , Electrodes , Female , Hemodynamics , Male , Pulmonary Edema/physiopathology , Respiration, ArtificialSubject(s)
Lung Diseases/diagnosis , Plethysmography, Impedance , Pulmonary Circulation , Animals , HumansABSTRACT
Experimental grounds for using clinically the chest impedence recording are presented. The method allows recording of ventilatory and hemodynamic parameters mainly in the minor circulatory circuit under conditions of surgery on thoracic organs and postoperatively, as well.
