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1.
Phys Chem Chem Phys ; 25(13): 9648-9655, 2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-36943208

RESUMEN

Reversible phase transformation in the Brodie graphite oxide-acetonitrile system, which is intercalation or release of part of the sorbed liquid from the interplanar space accompanied by an increase or a decrease in interplanar distances, is commonly observed in twice-oxidized materials. We observed this phenomenon for once-, twice- and thrice-oxidized materials using the EPR spin probe technique, DSC, and temperature programmed XRD. It was shown that all materials under study formed similar low temperature (LT) and high temperature (HT) swollen structures with acetonitrile. The phase transformation of these structures is observed for materials with different oxidation levels in the same temperature range (∼20 K). The twice- and thrice-oxidized Brodie graphite oxides form swollen structures with the same parameters, while the once-oxidized material sorbs less acetonitrile at lower temperatures, but shows the same interplanar distances as those in twice- and thrice-oxidized materials. The spin probe technique has proven its sensitivity to the appearance of small amounts of the new forming swollen structures, which makes this method useful in studies of phase transformations.

2.
Membranes (Basel) ; 13(1)2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36676860

RESUMEN

The comparative study of sorption of polar substances acetonitrile and water into powders and membranes (>10 µm thick) of modified Hummers (HGO) and Brodie (BGO) graphite oxides was performed using isopiestic method (IM) and differential scanning calorimetry (DSC). Additional sorption data were obtained for pyridine and 1-octanol. Sorption measurements were accompanied by conventional XRD and XPS control. Electron paramagnetic resonance (EPR) was additionally used to characterize ordering of the membranes. The impact on sorption of synthetic procedure (Brodie or Hummers), method of making membranes, chemical nature of the sorbent, and method of sorption was systematically examined. It was demonstrated that variations in synthetic procedures within both Hummers and Brodie methods did not lead to changes in the sorption properties of the corresponding powders. Sorption of acetonitrile and pyridine was reduced by approximately half when switching from powders to membranes at ambient temperature. DSC measurements at a lower temperature gave equal sorption of acetonitrile into HGO powder and membranes. Water has demonstrated unique sorption properties. Equal sorption of water was measured for HGO membranes and powders at T = 298 K and at T = 273 K. It was demonstrated that lowering the orientational alignment of the membranes led to the increase of sorption. In practice this could allow one to tune sorption/swelling and transport properties of the GO membranes directly by adjusting their internal ordering without the use of any composite materials.

3.
Photoacoustics ; 12: 55-66, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30450280

RESUMEN

The multispectral modality and technique for optically dense samples of optoacoustic spectroscopy were applied to measure spectra and high absorbances of concentrated aqueous dispersions of undoped nanodiamonds. The data from optoacoustic and optical transmission measurements and DSC data of the mean particle size by the Gibbs-Kelvin equation are compared to estimate the difference in composition of various nanodiamond trademarks. Optoacoustic spectra confirm the contribution of surface dimer chains into the absorption of nanodiamonds in the long wavelength range. Optoacoustic and conventional absorption spectra of aqueous solutions of nanodiamond fractions after centrifugation (15300g) and ultracentrifugation (130000g) revealed a separation of a highly absorbing non-diamond sp2 phase. The two-step separation by ultracentrifugation followed by extra centrifugation made it possible to isolate a highly absorbing and soluble nanodiamond phase with the particle size of 3.6 nm, showing a change in spectra compared to the starting nanodiamond material.

4.
Adv Gerontol ; 30(4): 498-504, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-28968023

RESUMEN

According to the State Statistics a the indicators of primary disability in 2003-2015 years in Russia were studied, taking into account the population in working and over working age first time recognized as disabled persons. The necessity of medical organizations improvement during the medical and social expertise of patients in different ages was shown. The characteristics of social and medical features of the primary disability were presented that should be taken into consideration in the development of social protection programs, rehabilitation of disabled people and disability prevention, especially among elderly citizens.


Asunto(s)
Personas con Discapacidad/estadística & datos numéricos , Adulto , Factores de Edad , Anciano , Personas con Discapacidad/rehabilitación , Humanos , Persona de Mediana Edad , Prevención Primaria/organización & administración , Desarrollo de Programa , Política Pública , Federación de Rusia
5.
Adv Gerontol ; 30(3): 398-402, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-28849885

RESUMEN

According to the State Statistics a comparative analysis of total disability in the Russian Federation in 2010-2016 years was conducted, taking into account the performance of the working-age and over working-age population. The necessity of integration policy towards the older generation and social policy in respect of disabled persons is shown: it is advisable to make adjustments to the national strategies and programs involving the duties of authorities to protect and promote the rights of disabled people, the development of preventive, rehabilitation, medical and social trends in the interests of senior citizens are involved.


Asunto(s)
Envejecimiento , Personas con Discapacidad , Estado de Salud , Anciano , Humanos , Política Pública , Federación de Rusia
6.
Bull Exp Biol Med ; 163(1): 25-27, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28580486

RESUMEN

In Wistar rats, stress was modeled by 24-h immobilization in a supine posture and stress-induced damage to the heart was assessed by accumulation of 99mTc-pyrophosphate in the myocardium. The intensity of stress reaction was measured by serum levels of cortisol and insulin. Both stressinduced damage to the heart and intensity of stress reaction were examined under control conditions and in rats treated with opioid receptor antagonists naltrexone, methylnaltrexone bromide, MR2266, and ICI174.864. Activation of central µ-opioid receptors with endogenous opioids aggravated stress-induced cardiomyopathy, while stimulation of peripheral µ-opioid receptors produced a cardioprotective effect. The stress-induced damage to the heart was not directly related to up-regulation of cortisol secretion in response to 24-h immobilization. Blockade of the central opioid receptors promoted a decrease in cortisol level in stressed rats.


Asunto(s)
Corazón/efectos de los fármacos , Antagonistas de Narcóticos/farmacología , Péptidos Opioides/metabolismo , Estrés Fisiológico/efectos de los fármacos , Animales , Masculino , Naltrexona/análogos & derivados , Naltrexona/farmacología , Compuestos de Amonio Cuaternario/farmacología , Ratas , Ratas Wistar , Receptores Opioides/metabolismo
7.
Ross Fiziol Zh Im I M Sechenova ; 102(10): 1195-1205, 2016 Oct.
Artículo en Ruso | MEDLINE | ID: mdl-30193437

RESUMEN

It was investigated the involvement of cardiac Ϭ-opioid receptors (OR) in increasing the resistance of the heart and myocardial mitochondria to ischemia-reperfusion after adaptation rats to chronic continuous normobaric hypoxia (CCNH). Rats were subjected to CCNH for 21 days at 12 % O2. It was evoked global ischemia (45 minutes) and reperfusion (30 minutes) of the isolated perfused heart. Adaptation to CCNH promoted a reduction of creatine kinase release from necrotic cardiomyocytes during reperfusion and improved reperfusion recovery of heart contractility. Mitochondrial respiratory and state of MPT pore were more resistant to ischemia-reperfusion in adapting rats. Perfusion of isolated hearts with TIPP(0) (30 nM/l, a selective Ϭ-OR-antagonist) or naltriben (1 nM/l, a selective 52-OR-antagonist) completely eliminated the cardioprotective effect of CCNH. BNTX (1 nM/l, a selective Ϭ-OR-antagonist) had no effect on the cardioprotective effect of CCNH. This data suggest that cardiac 52-OR involved in the increased resistance of the heart and mitochondria to ischemia-reperfusion after adaptation rats to CCNH.


Asunto(s)
Adaptación Fisiológica , Hipoxia/metabolismo , Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocardio/metabolismo , Receptores Opioides delta/metabolismo , Animales , Hipoxia/patología , Hipoxia/fisiopatología , Masculino , Mitocondrias Cardíacas/patología , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/patología , Ratas , Ratas Wistar
8.
Ter Arkh ; 85(4): 43-6, 2013.
Artículo en Ruso | MEDLINE | ID: mdl-23808291

RESUMEN

The paper gives the International Classification of Functioning, Disability, and Health (ICF), interactions between health changes, the personality and social factors of an individual with therapeutic diseases to define disability criteria and a scientific rationale for the necessity and scope of rehabilitative measures through public health and social protection organizations.


Asunto(s)
Evaluación de la Discapacidad , Personas con Discapacidad/clasificación , Medicina Interna/métodos , Índice de Severidad de la Enfermedad , Personas con Discapacidad/rehabilitación , Humanos , Medicina Interna/clasificación , Medicina Interna/normas , Organización Mundial de la Salud
10.
Langmuir ; 20(11): 4363-8, 2004 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-15969139

RESUMEN

Highly stable and reproducible molecular-colloidal water solutions of C60 fullerenes (FWS) obtained by transferring fullerenes from an organic solution into an aqueous phase with the help of ultrasonic treatment are investigated by means of small-angle neutron scattering (SANS). A polydispersity in the size of detected particles up to 84 nm is revealed. These particles are slightly anisotropic and have a characteristic size of approximately 70 nm. Along with it, there are some indications that a significant part of fullerenes composes particles with the size of the order of 1 nm. The contrast variation based on mixtures of light and heavy water shows that the mean scattering length density of the particles is close to that of the packed fullerene associates as well as that the characteristic size of possible fluctuations of the scattering length density within the particles does not exceed 2 nm. A smooth surface resulting in the Porod law for the scattering is detected. A number of models discussed in the literature are considered with respect to the SANS data.

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