Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Dokl Biol Sci ; 486(1): 69-71, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31317447

RESUMEN

We studied aggression in male Sprague-Dawley rats in a model of a depressive-like state induced by unpredictable treatment with ultrasonic waves with the frequencies of 20-45 kHz for 1, 2 or 3 weeks. We did not find any increase in the number of animals exhibiting aggression in the "resident-intruder" test after the treatment of any selected duration. However, the aggressive animals exposed to ultrasound exhibited the substantially increased number of attacks and their total duration as well as decreased latency of the first attack compared to the respective indices in the animals of the control group. Taking this into account, it is possible to suggest that the initial level of aggression increases in a model of ultrasonic chronic stress.


Asunto(s)
Agresión/efectos de la radiación , Ondas Ultrasónicas/efectos adversos , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción
2.
Bull Exp Biol Med ; 165(2): 181-183, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29923007

RESUMEN

We studied the effects of social isolation for 1, 2 or 3 weeks on behavioral reactions of male rats. As social isolation is a common model for inducing depressive-like state in rodents, classical tests for depressive-like behavioral features were conducted: Porsolt forced swimming test and tests for anhedonia and social interest. None of the experimental groups showed statistically significant disorders in comparison with the control group kept under standard conditions. Thus, social isolation for up to 3 weeks did not cause behavioral abnormalities in male rats. Single housing can be used in other models of induction of depressive-like states, but the use of this paradigm as an independent model for the development of depressive-like behavior requires longer period of social isolation.


Asunto(s)
Conducta Animal/fisiología , Aislamiento Social/psicología , Animales , Depresión/etiología , Conducta Exploratoria , Vivienda para Animales , Masculino , Actividad Motora/fisiología , Ratas , Ratas Sprague-Dawley , Estrés Psicológico/fisiopatología , Natación , Factores de Tiempo
3.
Bull Exp Biol Med ; 163(5): 599-601, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28948550

RESUMEN

We studied the effect of electroconvulsive therapy on cognitive functions in rats with depression-like disorder caused by exposure to ultrasound of varying frequency (20-45 kHz). Object recognition and Morris water-maze tests revealed no negative effects of the therapy on memory. Moreover, positive effect of therapy was demonstrated that manifested in amelioration of memory disturbances in depression-like disorders in these behavioral tests. The results of this study do not support the idea about side effects of electroconvulsive therapy, in particular, development of transient amnesia, and are a prerequisite for a more thorough study of internal mechanisms of the effect of the therapy on cognitive sphere.


Asunto(s)
Depresión/etiología , Depresión/terapia , Terapia Electroconvulsiva/métodos , Ondas Ultrasónicas/efectos adversos , Animales , Cognición/efectos de la radiación , Masculino , Memoria/efectos de la radiación , Ratas
4.
Bull Exp Biol Med ; 163(4): 409-411, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28853099

RESUMEN

Stress-induced changes in the behavior of CBA and BALB/c mice were studied after 3-week ultrasound exposure (22-45 kHz). The mice of both lines demonstrated increased aggression in the resident-intruder and social interest paradigms and reduced number of social interactions in the social interest test. Elevated plus maze test showed a decrease in anxiety level in CBA mice and an increase in this parameter in BALB/c mice. Chronic exposure to ultrasound induced an increase in aggression level in mice of both lines that was not directly related to changes in anxiety level.


Asunto(s)
Agresión/efectos de la radiación , Ansiedad/terapia , Aprendizaje por Laberinto/efectos de la radiación , Ondas Ultrasónicas , Animales , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Ensayos Clínicos Controlados Aleatorios como Asunto
5.
Opt Express ; 25(14): 16754-16760, 2017 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-28789176

RESUMEN

In this work we report, to the best of our knowledge, the first quantum well electrically-pumped microdisk lasers monolithically deposited on (001)-oriented Si substrate. The III-V laser structure was epitaxially grown by MOCVD on silicon with an intermediate MBE-grown Ge buffer. Microlasers with an InGaAs/GaAs quantum well active region were tested at room temperature. Under pulsed injection, lasing is achieved in microlasers with diameters of 23, 27, and 31 µm with a minimal threshold current density of 28 kA/cm2. Lasing spectrum is predominantly single-mode with a dominant mode linewidth as narrow as 35 pm.

6.
Bull Exp Biol Med ; 163(3): 296-298, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28744648

RESUMEN

We studied the effect of ultrasonic waves with a frequency of 20-45 kHz on behavioral reactions of rats after 7, 14 and 21 days of continuous exposure. A decrease in the number of social contacts in the social interest test was recorded in all groups, while lengthening of immobility time in Porsolt test was found only in the groups exposed to ultrasound for 2 and 3 weeks. Memory impairment in the new object recognition test was recorded only after 21 days of stressing. Chronic exposure to ultrasound of variable frequencies leads to the development of a depressive-like state in rats and the duration of exposure affects the specificity of the observed disorders. Different protocols of using of this model help to determine the stages of depressive-like condition in rats that can serve as a basis for the development of new methods of depressive disorders treatment.


Asunto(s)
Conducta Animal/efectos de la radiación , Trastorno Depresivo/etiología , Pérdida de Tono Postural/efectos de la radiación , Trastornos de la Memoria/etiología , Ondas Ultrasónicas/efectos adversos , Animales , Trastorno Depresivo/fisiopatología , Masculino , Trastornos de la Memoria/fisiopatología , Ratas , Ratas Sprague-Dawley , Habilidades Sociales , Factores de Tiempo
7.
Sci Rep ; 4: 4280, 2014 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-24594587

RESUMEN

Current interest in nanomaterials is focused mostly on artificial materials fabricated for various applications. However, naturally occurring nanocrystal arrays, like those recently found in the meteorite that fell near Chelyabinsk in Russia on 15 February, 2013, can provide some new insights into the nature of nanomaterials, including the conditions for their natural occurrence. Here we report the results of our spectroscopic investigation of a fragment of the Chelyabinsk meteorite. The atomic structure of a fragment of the Chelyabinsk meteorite was studied using high-resolution transmission electron microscopy. Elemental and phase analysis of the object that was carried out by energy dispersive X-ray spectroscopy and electron diffraction revealed the presence of crystalline phases of different chemical compounds specific to meteorites of the LL group. In addition to single-crystal inclusions, extensive areas with ferropericlase nanocrystals having characteristic sizes from 3 to 15 nm were found in the structure of the meteorite. The study of the meteorite employing combination scattering of light (Raman) and photoluminescence spectroscopy methods has revealed quantum effects of ferropericlase nanoparticles and related photoluminescence with a maximum in the range of 675-800 nm.

8.
Urologiia ; (1): 54-7, 2004.
Artículo en Ruso | MEDLINE | ID: mdl-15022446

RESUMEN

Present-day urology in the Russian Federation combines achievements of classic surgery with innovations of the last two decades which radically changed approaches to treatment of many urological diseases. Wide introduction in clinical practice of low invasive endoscopic and roentgenoendoscopic (endourologic) techniques is a standard for urology progress worldwide. N. A. Lopatkin, academician of Russian Academy of Medical Sciences, contributed much to advances of domestic urology. He has organized endourological service as a basis of further technological progress, introduction of low-invasive methods alternative to traumatic open surgical interventions.


Asunto(s)
Endoscopía/métodos , Enfermedades Urológicas/diagnóstico por imagen , Enfermedades Urológicas/cirugía , Femenino , Humanos , Masculino , Radiografía/métodos , Resultado del Tratamiento
9.
Urologiia ; (6): 21-6, 2004.
Artículo en Ruso | MEDLINE | ID: mdl-15719725

RESUMEN

Transurethral intraprostatic injection of ethanol (IIE) is a new low-invasive method in the treatment of benign prostatic hyperplasia (BPH). We made dog and rat experiments to prove safety and efficacy of IIE. The experiment was made on 10 rats and 10 dogs injected transurethrally (Prostaject device) with 96% ethyl alcohol in 10% volume of estimated volume of the prostate. The injection was followed by measurement of blood alcohol, the test for hemolysis. Transurethral ultrasound control of prostate size 1, 3 and 6 months after the injection and histological examinations 1, 3, 7, 14 days and 1, 3 and 6 months after the injection were made. It was found that blood alcohol after the above injection was not elevated. Necrosis was documented in all the cases but subsequently the necrotic site was replaced with sclerotic tissue. The necrosis involved only the prostatic capsule. The size of the prostate diminished by 29%. Thus, transurethral injection of ethyl alcohol (10% of prostate size) is safe and effective in achievement of prostatic gland ablation. Therefore, clinical trials of the method in patients with benign prostatic hyperplasia are justified.


Asunto(s)
Etanol/administración & dosificación , Próstata/patología , Hiperplasia Prostática/terapia , Animales , Perros , Inyecciones Intralesiones/instrumentación , Inyecciones Intralesiones/métodos , Masculino , Modelos Animales , Necrosis , Próstata/diagnóstico por imagen , Próstata/efectos de los fármacos , Ratas , Factores de Tiempo , Ultrasonografía
11.
Biochemistry (Mosc) ; 63(8): 952-62, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9767187

RESUMEN

The thermal unfolding of turkey gizzard smooth muscle myosin subfragment 1 (S1) and heavy meromyosin (HMM) in the absence of added nucleotides, in the presence of ADP, and in S1 or HMM ternary complexes with ADP and Pi analogs, orthovanadate (Vi), beryllium fluoride (BeFx), or aluminum fluoride (AlF4-), have been studied by differential scanning calorimetry (DSC). It has been shown that the formation of these ternary complexes causes significant structural changes in S1 or in the heads of HMM which are reflected in a pronounced increase of the protein thermal stability. The effect of BeFx was less distinct than that of AlF4- or Vi. Phosphorylation of regulatory light chains (RLC) in S1 or in HMM had practically no influence on these effects. In general, the changes caused by various Pi analogs in smooth muscle S1 or HMM were similar to those observed earlier with skeletal muscle S1 devoid of RLC. It is concluded that RLC and their phosphorylation do not significantly affect the character of structural changes induced in motor domains of the HMM heads by the formation of ternary complexes HMM--ADP--Vi, HMM--ADP--AlF4-, and HMM--ADP--BeFx--stable analogs of the intermediate states of the HMM ATPase reaction, HMM.ADP.Pi and HMM. ATP.


Asunto(s)
Adenosina Difosfato/metabolismo , Subfragmentos de Miosina/química , Subfragmentos de Miosina/metabolismo , Desnaturalización Proteica , Compuestos de Aluminio/metabolismo , Compuestos de Aluminio/farmacología , Animales , Berilio/metabolismo , Berilio/farmacología , Rastreo Diferencial de Calorimetría , Fluoruros/metabolismo , Fluoruros/farmacología , Molleja de las Aves , Calor , Cinética , Músculo Liso , Miosinas/metabolismo , Fosfatos/metabolismo , Pliegue de Proteína , Termodinámica , Pavos , Vanadatos/metabolismo , Vanadatos/farmacología
12.
Radiats Biol Radioecol ; 38(1): 126-33, 1998.
Artículo en Ruso | MEDLINE | ID: mdl-9606415

RESUMEN

Theoretical and practical problems related to the dosimetric data verification for recovery workers at the Chernobyl NPP are considered. The distinctions in definitions epsilon-entropy in paper [1] and delta-entropy in [2] are considered. In a certain measure this distinctions explain distinction in conclusions, made in these papers. Method of dosimetric data collection, used by Institute of Biophysics and its difference from the method of data acquisition, used in national Medical-dosimetric registers is described. Results on determination of a share of participants given for various clean-up worker divisions, contained in pointed delta-shape peaks, received by two various methods, stated in [2] and [6], are compared and their satisfactory conformity with one another is established.


Asunto(s)
Exposición Profesional , Ocupaciones , Centrales Eléctricas , Dosis de Radiación , Liberación de Radiactividad Peligrosa , Humanos , Modelos Teóricos , Ucrania
13.
Biochemistry (Mosc) ; 63(3): 322-33, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9526129

RESUMEN

This review is concerned with the application of the method of differential scanning calorimetry (DSC) to structural and functional studies of myosin and actin--the main two proteins of muscles and many other systems of biological motility. The domain organization of these proteins as revealed by DSC is considered. Data are presented on the conformational changes which occur in the myosin head and in F-actin due to the formation of the ternary complexes with ADP and Pi analogs (such as orthovanadate, beryllium fluoride, or aluminum fluoride). Recent data on the application of DSC to studies on the interaction of F-actin with myosin heads and with tropomyosin are also considered. It is concluded that DSC offers a new and promising approach to probe the structural changes which occur in the myosin head and in F-actin during ATP hydrolysis and due to interaction of these proteins with each other.


Asunto(s)
Actinas/química , Miosinas/química , Animales , Rastreo Diferencial de Calorimetría , Humanos , Modelos Moleculares
14.
J Muscle Res Cell Motil ; 17(4): 475-85, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8884602

RESUMEN

The effects of various modifications of rabbit skeletal myosin subfragment 1 on the thermal denaturation of subfragment 1 in ternary complexes with Mg-ADP and orthovanadate (V1) or beryllium fluoride (BeFx) have been studied by differential scanning calorimetry. It has been shown that specific modifications of SH1 group of Cys-707 by different sulfhydryl reagents, trinitrophenylation of Lys-83, and reductive methylation of lysine residues promote the decomposition of the S1.ADP.Vi complex and change the character of structural transitions of the subfragment 1 molecule induced by the formation of this complex, but they have much less or no influence on subfragment 1 thermal stability in the S1.ADP.BeFx complex. Thus, the differential scanning calorimetric studies on modified subfragment 1 preparations reveal a significant difference between S1.ADP.Vi and S1.ADP.BeFx complexes. It is suggested that S1.ADP.Vi and S1.ADP.BeFx complexes represent structural analogues of different transition states of the ATPase cycle, namely the intermediate states S1**.ADP.Pi and S1*.ATP, respectively. It is also proposed that during formation of the S1.ADP.Vi complex the region containing both Cys-707 and Lys-83 plays an important role in the spread of conformational changes from the active site of subfragment 1 ATPase throughout the structure of the entire subfragment 1 molecule. In such a case, the effects of reductive methylation of lysine residues on the subfragment 1 structure in the S1.ADP.Vi complex are related to the modification of Lys-83.


Asunto(s)
Adenosina Difosfato/metabolismo , Berilio/metabolismo , Fluoruros/metabolismo , Subfragmentos de Miosina/metabolismo , Vanadatos/metabolismo , Animales , Rastreo Diferencial de Calorimetría , Indicadores y Reactivos/metabolismo , Lisina/metabolismo , Metilación , Picratos/metabolismo , Conejos , Relación Estructura-Actividad , Compuestos de Sulfhidrilo/metabolismo
15.
Biofizika ; 41(1): 64-72, 1996.
Artículo en Ruso | MEDLINE | ID: mdl-8714460

RESUMEN

This short review is concerned with the application of the method of differential scanning calorimetry to study the conformational changes of isolated myosin head (myosin subfragment 1, S1) caused by the formation of the S1 complexes with Mg(2+)-ADP and P(i) analogues such as orthovanadate (V), aluminium fluoride (AIF4-) or beryllium fluoride (BeFx). These changes of the whole S1 molecule are reflected in a significant increase of S1 thermal stability and in a pronounced increase of the cooperativity of the thermal denaturation. Since the complexes S1-ADP-V, S1-ADP-AIF4- and S1-ADP-BeFx are stable analogues of the S1**-ADP-P(i) transition state of the S1-catalyzed ATP hydrolysis, it is concluded that DSC studies with these complexes offer a new and promising approach to investigate the structural changes which occur in the myosin head during Mg(2+)-ATPase reaction.


Asunto(s)
Adenosina Difosfato/análogos & derivados , Subfragmentos de Miosina/química , Fosfatos/química , Animales , ATPasa de Ca(2+) y Mg(2+)/metabolismo , Rastreo Diferencial de Calorimetría , Subfragmentos de Miosina/metabolismo , Conformación Proteica , Conejos
16.
Radiats Biol Radioecol ; 35(6): 803-28, 1995.
Artículo en Ruso | MEDLINE | ID: mdl-8563905

RESUMEN

It is considered the organization of individual dosimetric monitoring (IDM) within 30-km zone around Chernobyl nuclear power plant (CNPP) in 1986 for different contingents of recovery workers: the CNPP personnel, Management for Construction 605 (MC-605), military recovery workers, persons assigned to 30-km zone. It is concluded that the quality of IDM had decreased in the following series: the MC-605 personnel, the CNPP personnel, the assigned persons, and military units. The method of dosimetric data verification for recovery workers in 1986 is presented which is based on the analyses of the dependency H(delta)/In delta from delta, where delta is a step of the histogram of distribution, and H(delta) is delta-entropy of distribution. The results obtained by this method correspond to the results of the experts' estimation. It was shown that 60% of registered individual doses for the whole contingent of the recovery workers differ from the real exposure doses. Using the theory of hybrid lognormal distribution it was obtained, in our opinion, real external dose distribution for all the recovery workers. It was estimated that 7% of recovery workers received doses more than 0.25 Gy. Also, the data on values of mean and collective doses for different contingents, as well as for all persons involved in recovery operations is presented.


Asunto(s)
Exposición Profesional/estadística & datos numéricos , Centrales Eléctricas/estadística & datos numéricos , Liberación de Radiactividad Peligrosa/estadística & datos numéricos , Dosimetría Termoluminiscente/estadística & datos numéricos , Absorción , Partículas beta , Rayos gamma , Humanos , Personal Militar/estadística & datos numéricos , Dosis de Radiación , Estudios Retrospectivos , Factores de Tiempo , Ucrania , Recursos Humanos
17.
Biokhimiia ; 60(7): 1100-10, 1995 Jul.
Artículo en Ruso | MEDLINE | ID: mdl-7578566

RESUMEN

The effects of trinitrophenylation of lysyl residues of rabbit skeletal myosin subfragment 1 (S1) on thermal denaturation of S1 in the absence of nucleotides, in the presence of ADP and within S1 complexes with ADP and Pi analogues, orthovanadate (Vi) or beryllium fluoride (BeFx), have been studied by differential scanning calorimetry. It has been shown that lysyl trinitrophenylation significantly affects the thermal stability of S1, changes its domain structure, promotes the decomposition of S1.ADP.Vi and S1.ADP.BeFx complexes, and strongly prevents the structural changes in the S1 molecule induced by the formation of the S1.ADP.Vi complex without any effect on the thermal stability of S1 within S1.ADP and S1.ADP.BeFx complexes. It has been demonstrated that the effects of trinitrophenylation on the S1 structure are mainly due to specific modification of the epsilon-amino group of the Lys-83 residue.


Asunto(s)
Lisina/química , Subfragmentos de Miosina/química , Nucleótidos/metabolismo , Animales , Rastreo Diferencial de Calorimetría , Calor , Lisina/metabolismo , Músculo Esquelético/química , Subfragmentos de Miosina/metabolismo , Unión Proteica , Desnaturalización Proteica , Conejos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...