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Biomedical subjects

V G Golubev

Publications and source records attributed to V G Golubev.

At least 19 recordsLinked to original sources
PubMed2003

Ultrafast optical switching in three-dimensional photonic crystals.

We present the first experimental investigation of ultrafast optical switching in a three-dimensional photonic crystal made of a Si-opal composite. Ultrafast (30 fs) changes in reflectivity around the photonic stop band up to 1% were measured for moderate pump power (70 microJ/cm(2)). Short-lived photoexcited carriers in silicon induce changes in the dielectric constant of Si and diminish the constructive interference inside the photonic crystal. The results are analyzed within a model based on a two-band mixing formalism.

Journal Article↗
PubMed2003

Polarization splitting of optical resonant modes in a-Si:H/a-SiO(x):H microcavities.

We present experimental and theoretical results on polarization splitting of optical resonant modes in a-Si:H/a-SiO(x):H microcavities. It is shown experimentally that the splitting sign and value can be controlled by varying the active layer thickness. The polarization splitting achieved in the microcavities is about 8 meV owing to a large optical contrast, which is the ratio of film refractive indices in the distributed Bragg reflectors. The experimental data and theoretical analysis show that the polarization splitting may be zero at a certain angle of incidence of light determined by the microcavity parameters. The measured and calculated resonant frequency values for TM and TE polarizations were used to find the optical thickness of the active layer and the stop-band center frequency of the Bragg reflector. The account of the active layer thickness fluctuations along the lateral direction provides a better fit between the experimental and theoretical spectra.

Journal Article↗
PubMed1990

Transfer of free vascularized bone and skin-bone autografts: experiences in the application of external fixation apparatus.

The results of transfer of free vascularized bone and skin-bone autografts in 95 patients with defects (54) and nonunions (41) of tubular bones of different genesis are presented. In 71 cases, an external fixation apparatus was used for purposes of osteosynthesis. In 50 cases, the Ilizarov apparatus was applied prior to osteoplasty to correct deformity and fully or partially to correct a shortening of the extremity bone segment. In seven cases, lengthening of the bone segment was performed using an external fixation apparatus after osteoplastic reconstruction of the defect. Treatment was completed in 76 cases (80.0 percent); of these, the outcome was positive in 89.5 percent of cases. Failure was recorded in 10.5 percent of cases. The advantages of using an external fixation apparatus in combination with vascularized bone and osteocutaneous autografts are discussed.

Adolescent↗
PubMed1990

[Possibilities of improving medical and socioeconomic effectiveness of the treatment of patients with myocardial infarct by physical training during posthospital stage of rehabilitation].

Two groups of patients with myocardial infarction were compared for outcomes of rehabilitation. In group 1, rehabilitative therapy was performed by using conventional methods. In group 2, that was done on the basis of early activation and application of physical trainings 2 weeks following myocardial infarction. Physical trainings caused an increase in exercise tolerance and myocardial contractility and a decrease in left ventricular failure, which enhanced the proportion of individuals who returned to work and diminished deaths at a 2-year follow-up.

Follow-Up Studies↗
PubMed1989

[Errors and complications of plastic surgery of defects and false joints of the humerus using free vascularized bone autografts].

The authors analyse the errors and the complications in the plasty of defects and false joints of the humerus with free vascularized bone autografts in 20 patients aged 8-50 with the period of duration of the disease from 6 months to 9 years. The size of the defect was 3-20 cm (15 patients). In 17 cases a fibular bone graft on a vascular pedicle was used. In 8 patients 14 various kinds of complications occurred in different combinations. Non-union of one of the ends of the graft was observed most frequently (4) due to faults of osteosynthesis. In all patients consolidation was achieved. In this type of complications the authors advise to make an early repeated intervention with the aim of shortening the duration of treatment and subsequent rehabilitation. They stress the perspective character and the validity of this method of plasty, especially in extensive defects in association with poor vascularization of the injured segment of the extremity. Accurate performance of all stages of the intervention and the surgeon's personal experience play an important role in prevention of errors and complications in employing microsurgical technique in the treatment of this category of patients.

Adolescent↗
PubMed1988

[Effect of complications in the acute period of myocardial infarction on physical exertion tolerance at the hospital stage of rehabilitation].

Physical stress tolerance and its hemodynamic support were examined in 95 patients with early myocardial infarction, 50 normal subjects and 25 coronary patients. It is suggested that the stress tolerance test is advisable at an early stage of complicated macrofocal myocardial infarction. The safety of the test improves considerably where it is performed under continuous electrocardiographic and chest-rheographic control. An abnormal diastolic impedance wave, emerging during exercise, may serve an additional diagnostic indicator of stress intolerance.

Adult↗
PubMed1987

[Comparison of the efficacy of different programs of physical rehabilitation for myocardial infarct patients and possibilities of increasing it by incorporating physical training at the hospital stage of rehabilitation therapy].

The efficiency of rehabilitation can be improved through early activation of the patients and the beginning of exercise as early as the hospital stage of rehabilitation. The intensity of exercise should be rationed on a strictly individual basis, with regard to the patient's functional status. Hospital exercise in combination with purposeful psychotherapy are major prerequisites for the recovery of working capacity.

Adult↗
PubMed1986

[Free bone and skin-bone autoplasty on a vascular pedicle in patients with defects and pseudarthroses].

Radical sequestr- and necrectomy followed by skin, bone or skin-bone autoplasty on the vascular pedicle with microvascular anastomoses between the autotransplant vessels and those of the extremity was successfully fulfilled in 16 patients with defects of tubular bones and false joints complicated by chronic osteomyelitis. The pedicled autografts were taken from the upper flaring portion of the ilium (13), from the fibula (2) and from the external surface of the femur (1). The two-step method of autoplasty is described.

Adult↗
PubMed1986

[Effect of the depth of the myocardial lesion (according to the EEG) on tolerance and hemodynamic support for various levels of physical loading in the early period of myocardial infarction].

A bicycle-ergometric study under continuous electrocardiographic and hemodynamic monitoring demonstrated that physical stress tolerance is conditioned by pre-existing myocardial contractility disturbance rather than the depth of heart muscle involvement (as evidenced by ECG) at early dates of myocardial infarction. The patients' capacity for doing exercise, on a stepwise basis, was limited by transitory myocardial ischemia as well as inadequate and incompetent hemodynamic support.

Adult↗
PubMed1985

[Tolerance and hemodynamic support for physical loading in patients in the early period of an acute large-focus myocardial infarct].

Tolerance to physical stress and hemodynamic support of the latter were compared in normal subjects, patients with chronic coronary disease and those at early stages after large-focal myocardial infarction. Tolerance to stress and its hemodynamic support were shown to be virtually identical in patients at early postinfarction stages and chronic coronary patients. It was therefore suggested that controlled bicycle ergometry was a safe test for patients at early stages after large-focal myocardial infarction (6 days, on average), and a useful one for the objective assessment of individual tolerance of varying load regimens.

Adult↗
PubMed1985

[Effect of intensive physical training on the hospital stage of the rehabilitation of patients with macrofocal myocardial infarct].

Thirty-five patients with large-focal myocardial infarction were divided into the main (21) and the control (14) groups. The main-group patients were subjected to intensive exercise beginning with day 10-22 of the disease; its program was designed so as to match the data of bicycle ergometry checkups and included bicycle-ergometric riding and rationed walking. It was demonstrated that the main group patients showed better physical stress tolerance, improved myocardial functional potentials, better psychological outlook and smaller pulmonary venous congestion at the time of transfer to the sanatorium stage of rehabilitation. It is suggested that exercise be incorporated in the hospital rehabilitation complex for patients with large-focal myocardial infarction.

Combined Modality Therapy↗