Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Urologiia ; (6): 40-46, 2021 12.
Artigo em Russo | MEDLINE | ID: mdl-34967163

RESUMO

INTRODUCTION: Despite the low invasiveness of percutaneous nephrolithotripsy, this surgery is not without complications. One of the most important stages of the operation, on which depends not only the success of the patient completely getting rid of calculus, but the likelihood of complications, is the puncture of the pelvic-pelvic system. PURPOSE: Determination of the effectiveness and security of the new less-traumatic puncture needle MG under experimental conditions. MATERIALS AND METHODS: A series of pork kidney punctures with a new less-traumatic needle MG and standard Chiba and Troakar needles (Coloplast A/S, Denmark) were performed under experimental conditions, followed by a comparative morphological assessment. The staining of the slides was performed with hematoxylin and eosin. For the purpose of additional assessment of the structures of the kidney punctured with a low-traumatic MG needle, a morphological assessment of the parenchyma stained with picrofuchsin according to Van Gieson was performed. RESULTS: On parenchymal slides with punctures with Chiba and Trocar needles, the passage places with multiple large fragments of desquamated (damaged) epithelium are visualized. On preparations of the parenchyma punctured with a less-traumatic needle MG, the place of passage of the needle is presented with clear contours. The damaged epithelium in the lumen of the formed defect is practically absent. With additional staining according to Van Gieson (magnification x200), the integrity of the full-blooded vessel adjacent to the limited focus of the needle MG was visualized. Output. The new less-traumatic puncture needle MG is an innovative development in urology. The design of the needle with an atraumatic mandrel-bulb atraumatic mandrel-bulb on a spring basis made it possible to significantly reduce the trauma to the structures of the kidney and perirenal tissues due to the bougienage effect.


Assuntos
Cálculos Renais , Litotripsia , Humanos , Rim , Agulhas , Punções
2.
J Phys Condens Matter ; 32(43): 435403, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32644050

RESUMO

The paper presents a semi-empirical wide-range equation of state (EOS) for platinum with account for melting, evaporation, and ionization. The equation is based on a wide spectrum of experimental and calculation data. Parameters for the EOS were adjusted using a genetic algorithm which proved to perform well for optimizations in big data processing. In the regions where no experimental data were available, we used results of first-principles and average-atom model calculations. The EOS was used to calculate the melting curve of platinum to pressures above 1 TPa, sound velocities along the Hugoniot curve, parameters of melting under shock compression, and parameters of the critical point. An improved model is proposed for the shear modulus in (V, T) coordinates and its variation along the shock adiabat is calculated.

3.
Carbohydr Polym ; 210: 135-143, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30732746

RESUMO

The article presents the results of the synthesis and research of a new biodegradable hybrid nanosized polymer-inorganic system possessing the double nature of heavy metal ions extraction from solutions. Firstly, the sorption of metal ions takes place by the ion-exchange properties of porous manganese oxide and, secondly, due to specific interaction and chelating with functional groups of polysaccharides in terms of nanochitin (ChNC). The synthesis is based on the colloid-chemical processes of interaction between polysaccharide and manganese oxide nanosized particles. Using the mathematical model of the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory, it has been shown that this interaction occurs due to the formation of hydrogen bonds and electrostatic interactions of oppositely charged particles. Hybrid sorbents were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, Transmission electron and Atomic force microscopy. The highest value of sorption capacity for hybrid materials was obtained for Ni2+ extraction and reached 114.0 ± 1.1 mg/g. It was shown that biodegradation of hybrid sorbents increases with the concentration of manganese oxide nanoparticles and almost complete degradation of the organic part can be performed within 6 days. The obtained biodegradable sorbents were designed to address ecological problems connected with the pollution of natural waters by toxic metallic ions.

4.
Carbohydr Polym ; 174: 1164-1171, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28821041

RESUMO

The hydrosols of chitin nanocrystals (ChN) are promising as modifiers of properties, drug delivery systems, and media. The purpose of this work is to clarify the mechanisms for regulating processes of stability and structure formation occurring in the ChN hydrosols under the influence of varying ionic strength. ChN were isolated from the crab shell; ChN hydrosols are obtained with different concentrations of the dispersed phase. The structure and morphology of the particles was studied by atomic force microscopy and X-ray diffraction. Hydrosols were studied by rotational viscometry, dynamic light scattering, and photometry in the presence of KCl with concentration up to 200mM. The experimental results of finding the rapid coagulation threshold are compared with calculated ones performed with the use of the modified DLVO theory. It is established that in the range of electrolyte concentrations 30∼75mM, the optical and rheological properties of the ChN hydrosols undergo crucial changes. At an electrolyte concentration of 20∼150mM, particles coagulate at a secondary potential minimum; the parallel orientation of the particles is energetically more advantageous. In systems with a higher concentration of electrolyte, there is no potential barrier; rapid barrier-free coagulation is observed, with the formation of stronger coagulation contacts and the formation of stable gels.

5.
Artigo em Russo | MEDLINE | ID: mdl-26322366

RESUMO

"Typical" antipsychotics remain the wide-prescribed drugs in modern psychiatry. But these drugs are associated with development of extrapyramidal symptoms (EPS). Preventive methods of EPS are actively developed and they concentrate on personalized approach. The method of taking into account genetic characteristics of patient for prescribing of treatment was proven as effective in cardiology, oncology, HIV-medicine. In this review the modern state of pharmacogenetic research of antipsychotic-induced EPS are considered. There are pharmacokinetic and pharmacodynamic factors which impact on adverse effects. Pharmacokinetic factors are the most well-studied to date, these include genetic polymorphisms of genes of cytochrome P450. However, evidence base while does not allow to do the significant prognosis of development of EPS based on genetic testing of CYP2D6 and CYP7A2 polymorphisms. Genes of pharmacodynamics factors, which realize the EPS during antipsychotic treatment, are the wide field for research. In separate part of review research of such systems as dopaminergic, serotonergic, adrenergic, glutamatergic, GABAergic, BDNF were analyzed. The role of oxidative stress factors in the pathogenesis of antipsychotic-induced EPS was enough detailed considered. The system of those factors may be used for personalized risk assessment of antipsychotics' safety in the future. Although there were numerous studies, the pharmacogenetic-based prevention of EPS before prescribing of antipsychotics was not introduced. However, it is possible to distinguish the most perspectives markers for further research. Furthermore, brief review of new candidate genes provides here, but only preliminary results were published. The main problem of the field is the lack of high- quality studies. Moreover, the several results were not replicated in repeat studies. The pharmacogenetic-based research must be standardized by ethnicity of patients. But there is the ethnical misbalance in world literature. These facts explain why the introduction of pharmacogenetic testing for risk assessment of antipsychotic-induced EPS is so difficult to achieve.


Assuntos
Antipsicóticos/efeitos adversos , Doenças dos Gânglios da Base/induzido quimicamente , Doenças dos Gânglios da Base/genética , Testes Genéticos , Farmacogenética/tendências , Antipsicóticos/farmacocinética , Doenças dos Gânglios da Base/etnologia , Marcadores Genéticos/genética , Predisposição Genética para Doença , Humanos , Medição de Risco
6.
Laser Ther ; 24(1): 15-26, 2015 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-25941421

RESUMO

BACKGROUND AND AIMS: The mortality rate from vascular diseases is one of the highest. The use of Intravenous Laser Blood Irradiation (ILBI) within the last 30 years has demonstrated high efficacy in the treatment of vascular, cardiac and other systemic diseases. RATIONALE: Laser energy at 630-640 nanometers is arguably the most effective for irradiation of blood and the vascular wall. Photons at this wavelength are absorbed by oxygen, improve microcirculation, can change the viscosity of the blood and affect vascular endothelium. CONCLUSIONS: In summary, more than 25 years of experience of using laser energy at 630-640 nm has shown that this waveband directly influences the parameters of all cells in the blood, blood plasma, the coagulation process and all the structural components of the vascular wall. Additionally, ILBI directly or indirectly affects the cells of the immune system, hormones, and exchange processes in an organism, thereby not only improving the function of the vascular system, but also the other systems of an organism. It can finally lead to lower the incidence and number of vascular diseases, and indirectly to the reduction of the number of diseases in other organs and even systemically, thus helping to prolong the lifespan.

7.
Aviat Space Environ Med ; 69(2): 137-41, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9491252

RESUMO

BACKGROUND: Altered thermoregulation has been reported following spaceflight simulations (bed rest and water immersion) but has never been examined after actual spaceflight. HYPOTHESIS: We tested the null hypothesis that body temperatures and heat loss responses during exercise would be similar before and after spaceflight. METHODS: Two male crewmembers of the 115-d Mir 18 mission performed supine submaximal cycle exercise (20 min at 40% and 20 min at 65% of preflight VO2peak) once at 145-146 d preflight and once at 5 d postflight (R + 5). RESULTS: After flight neither crewmember could complete the exercise protocol, stopping after 28-29 min. The core temperature (Tin, ingestible telemetry pill) at test termination was similar (37.8 degrees C for both subjects) pre- and postflight despite shorter postflight test duration. The slopes of the skin blood flow (laser Doppler)/Tin relationship (subject 1: 396 vs. 214; subject 2: 704 vs. 143% change Perfusion Unit/degree C), and the sweating rate (dew point hygrometry)/Tin relationship (subject 1: 6.3 vs. 2.0; subject 2: 4.6 vs. 0.7 mg.min-1.cm-2.degree C-1), were both reduced postflight without appreciable change in the Tin thresholds for sweating or skin blood flow. CONCLUSION: In this preliminary report for two crewmembers, the sensitivity of the heat loss responses were reduced after long-duration spaceflight, resulting in a faster rate of rise in core temperature.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Temperatura Corporal , Exercício Físico/fisiologia , Voo Espacial , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
8.
Biochim Biophys Acta ; 1317(1): 71-9, 1996 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-8876629

RESUMO

Fluorogenic 6-acylamino-4-methylumbelliferyl-beta-D-glucosides were found to be poor substrates for the three known human beta-glucosidases, i.e., lysosomal and non-lysosomal glucocerebrosidases and cytosolic broad-specificity beta-glucosidase. However, homogenates of human tissues and human cell types showed significant enzymatic hydrolysis of 6-ethanoylamino-4-methylumbelliferyl-beta-D-glucoside (EMGlc) due to the activity of a hitherto undescribed beta-glucosidase, called here EMGlc-ase. It was shown that the isozyme is hardly active towards 4-methylumbelliferyl-beta-D-glucoside or glucosylceramide. EMGlc-ase exhibits maximal activity at pH 4.5 and 5.0 in the absence and presence of sodium taurocholate respectively. It is a soluble lysosomal enzyme with a discrete isoelectric point of about 5.0. EMGlc-ase is not inhibited by conduritol B-epoxide, is activated by sodium taurocholate and binds strongly to Concanavalin A. This enzyme is not deficient in relation to Gaucher disease.


Assuntos
Glucosídeos/metabolismo , beta-Glucosidase/isolamento & purificação , beta-Glucosidase/metabolismo , Animais , Cromatografia em Agarose , Cromatografia em Gel , Fibroblastos , Fluorescência , Doença de Gaucher/enzimologia , Glucosilceramidase/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Himecromona/análogos & derivados , Himecromona/metabolismo , Ponto Isoelétrico , Rim/enzimologia , Fígado/enzimologia , Lisossomos/enzimologia , Ratos , Baço/enzimologia , Frações Subcelulares/enzimologia , Especificidade por Substrato , beta-Glucosidase/química , beta-Glucosidase/classificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...