Fish (Oncorhynchus mykiss) spermatozoa cryoprotectant-free vitrification: Stability of mitochondrion as criterion of effectiveness

The aim of the present investigations was to test a novel technology comprising cryoprotectant-free vitrification of the spermatozoa of rainbow trout and to study the ability of sucrose and components of seminal plasma to protect these cells from cryoinjuries. Spermatozoa were isolated and vitrified using five different mediums: Group 1: standard buffer for fish spermatozoa, Cortland®-medium (CM, control); Group 2: CM+1% bovine serum albumin (BSA); Group 3: CM+1% BSA+0.125M sucrose; Group 4: CM+1% BSA+40% seminal plasma; and Group 5: CM+1% BSA+40% seminal plasma+0.125M sucrose. For cooling, 20μL suspensions of cells from each group were dropped directly into liquid nitrogen. For warming, the spheres containing the cells were quickly submerged in CM+1% BSA at 37°C with gentle agitation. The quality of spermatozoa before and after vitrification was analysed by the evaluation of motility, cytoplasmic membrane integrity (SYBR-14/propidium iodide staining technique), and mitochondrial membrane integrity (JC-1 staining). Motility (86%, 71%, 80%, 81%, and 82%, for Groups 1, 2, 3, 4, and 5, respectively) and cytoplasmic membrane integrity (90%, 82%, 83%, 84%, and 87%, respectively) of spermatozoa in all the 5 groups were not decreased significantly. All tested solutions can be used for vitrification of fish spermatozoa with good post-warming motility and cytoplasmic membrane integrity. However, mitochondrial membrane potentials of the spermatozoa in Groups 1, 2, 3, 4, and 5 were changed significantly (6%, 50%, 37%, 55%, and 34%, respectively) (P1,2,3,4,5<0.001; P2,3,4,5 <0.01)(P3-5>0.1). This rate was maximal in Group 4 (CM+1% BSA+40% seminal plasma). In conclusion, this is the first report about successful cryoprotectant-free cryopreservation of fish spermatozoa by direct plunging into liquid nitrogen (vitrification). Vitrification of fish spermatozoa without permeable cryoprotectants is a prospective direction for investigations: these cells can be successfully vitrified with 1% BSA+40% seminal plasma without significant loss of important physiological parameters. © 2011 Elsevier B.V

Characteristics of the nitric oxide system indicators in the left ventricle myocardium in SHR

The aim was to determine the morpho-functional parameters of the left ventricular myocardium NO system in the rats with essential hypertension (SHR line). Material and methods. We used a combination of modern highly informative methods, namely: research of NOS isoform profie (nNOS, iNOS eNOS) in the myocardial slices along with an assessment of their synthesis and expression of the corresponding mRNA; NO derived nitrites level determination directly in the myocardium homogenates and concentration of nitrotyrosine in blood plasma of rats. The results of the performed studies have shown that high blood pressure in the SHR was accompanied by a signifiant increase in the concentrations of all three NOS isoforms in the myocardium and increased expression of their mRNA. Higher concentration of nitrites by 18.8 % was detected in the SHR group compared with the control animals. The concentration of nitrotyrosine in blood plasma of rats with essential hypertension was also increased by 25 %. Conclusions. The predominance of IRM to constitutive isoforms of NOS with low IRM content to iNOS was noted in the myocardium of the control group rats while in SHR rats higher IRM values were marked for all NOS isoforms. The formation of hypertension is accompanied by high content of NO end metabolites and the development of systemic nitroso-oxidative stress with the increase of nitrotyrosine concentration

Landscape science: a Russian geographical tradition

The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability

Radical surgery on the middle ear in the treatment of cholesteatoma: history or reality? A review

Radical surgery on the middle ear is primarily associated with such pathology as cholesteatoma and ear neoplasms. And if in the case of tumors radicalism in ear surgery is justified, then in the surgery of the cholesteatomic process there is a need to discuss this issue. The existence of acquired cholesteatoma was recognized more than three centuries ago. Without timely detection and intervention, cholesteatomas can increase to gigantic sizes and lead to numerous intracranial and extracranial complications. Due to its aggressive growth, invasive nature and potentially fatal consequences of intracranial complications, acquired cholesteatoma remains the cause of morbidity and death in those who do not have access to advanced medical care. Currently, there are no effective non-surgical methods of treatment. The article provides a brief overview of the main issues related to acquired middle ear cholesteatoma, and discusses the practica

Новые данные о поступлении радона в среду обитания человека

Radon transported from the atmosphere to the earth’s surface is shown to have a significant role in the formation of its concentration levels in the lowest atmospheric layers. The amount of radon escaping from the atmosphere with sporadically occurred rainfalls is quantitatively comparable with the amounts emitted from the soil into the atmosphere. A stable dependence has been established between the radon concentration levels in the surface atmosphere and the air humidityПоказана значимая роль радона, поступающего к земной поверхности из атмосферы, в формировании уровня его концентрации в приземных слоях атмосферного воздуха. Вынос радона из атмосферы спорадически выпадающими дождями количественно соизмерим с его выделением из грунта в атмосферу. Установлена устойчивая зависимость уровня концентрации радона в приземной атмосфере от влажности воздуха

О влиянии атмосферных осадков и лунно-солнечного гравитационного воздействия на концентрацию радона в поровом воздухе дисперсных грунтов

In the present study, the obtained data on the previously unknown behaviors of radon migration in the near-surface atmospheric and soil layers were validated experimentally. The experiment finds two earth origins of radon concentrations occurred in the air in the pores of the near-surface dispersive soil, intragenic and hypogenic, with a considerable atmospheric impact of the liquid forms of precipitation transporting radon from the atmosphere to the ground. The equations were used to establish the mathematical relation between the amounts of precipitation and atmospheric radon. We also assessed a relative contribution of the atmospheric and earth sources to the total radon concentration in the air in the soil pores. The atmospheric source was found to have a sporadically higher impact on the radon levels in the air in the soil pores as against the earth source, depending on the amounts of precipitation and radon concentrations in them. A close correlation was established between the radon concentrations in the soil and the effect of lunisolar gravitational forces on the earth’s crust. The findings of the radon levels in near-surface soils are expected to be applied as one of the criteria for environmental assessment of radon concentrations and associated threats.Получены экспериментально обоснованные данные, характеризующие ранее неизвестные особенности миграционного поведения радона в приземной атмосфере и приповерхностных слоях грунтов. Показано, что уровень концентрации радона в поровом воздухе дисперсного (песчаного) приповерхностного грунта формируется за счет двух земных источников – интрагенного и глубинного, при существенном вкладе атмосферного источника, обусловленного поступлением радона с жидкими атмосферными осадками, вымывающими его из атмосферы и доставляющими к земной поверхности. Определена форма математической зависимости между количеством выпадающих осадков и количеством атмосферного радона, и дана оценка относительного вклада атмосферного источника и земных источников радона в его суммарное содержание в поровом воздухе грунтов. Показано, что вклад атмосферного источника радона спорадически, в зависимости от количества выпадающих осадков и концентрации радона в них, может превышать вклад земных источников. Установлена тесная корреляционная связь между количеством грунтового радона и силой гравитационного лунно-солнечного воздействия на земную кору. Использование этой информации в практических целях представляется необходимым для обеспечения достоверности оценок радоноопасности окружающей среды, одним из критериев которых является уровень концентрации радона в грунтах.

THERMOELECTRIC PROPERTIES OF HOT-PRESSED p-TYPE Mg2Si0.3Sn0.7 SOLID SOLUTION

It is shown that thermoelectric energy conversion which gives the possibility for utilizing a low potential heat is one of the ways for adoption of energy-saving technologies; and semiconductor materials with p-type and n-type conductivities having high thermoelectric figure of merit are necessary for operation of thermoelectric generators. The paper deals with possibility of usage of the p-Mg2Si0.3Sn0.7 solid solution (with a nanostructured modification) as a couple for the well studied thermoelectric material based on n-Mg2Si-Mg2Sn. A technological scheme for fabrication of heavily doped Mg2Si0.3Sn0.7 solid solution of p-type by hot pressing from nanopowder is developed. The given technology has made it possible to reduce duration of a homogeneous material fabrication and has improved its physical and chemical properties. The samples were made by three ways: direct fusion for polycrystals fabrication; hot pressing from microparticles; nanostructuring, i.e. hot pressing from nanoparticles. By X-ray diffraction it is shown that sizes of structural elements in the fabricated samples are about 40 nm. The probe technique is used for measurement of electric conductivity and Seebeck coefficient. The stationary absolute method is used for measurement of thermal conductivity. Thermoelectric figure of merit is defined by measured values of kinetic coefficients in the temperatures range of 77 – 800 K. It was demonstrated, that electric conductivity, Seebeck coefficient and the power factor do not depend practically on a way of solid solution preparation. Thermal conductivity of samples pressed from nanoparticles has appeared to be higher, than of samples, obtained by direct fusion; i.e. in this case nanostructuring has not led to increase of thermoelectric figure of merit. The conclusion is drawn, that polycrystalline semiconductor Mg2Si0.3Sn0.7 can be used as a p-branch for a thermoelectric generator though nanostructuring has not led to the figure of merit growth. The assumption is made, that thermoelectric figure of merit improvement can be expected at the further reduction of the nanograins size