A method of measuring transmittance of radiation from the film of ice 0 in the IR wave band deposited on a dielectric plate

A method of measuring transmittance of radiation from the film of ice 0 in the infrared wave band is described. Ice 0 is formed from supercooled water at the temperature below –23°C. This ice is ferroelectric and forms a highly conductive layer of the nanometric order of thickness at the boundary with dielectric. The complexity of the experiment consisted in the necessity of using low intensities of the probing signal and considering radiation of the cooled parts of the installation. In order to obtain a thin film of ice, the method of depositing water vapor on a substrate cooled in nitrogen was used. The method rules out formation of condensate in cooling. Deposition of water vapor is possible only in heating, when delivery of cold nitrogen vapor into the chamber with the sample is excluded. To ensure exposure of the film to IR radiation, two sources of infrared radiation were considered: a halogen lamp with a broad radiation spectrum (on the surface of heated glass) and a CO2 laser with the radiation wavelength of 10.6 µm. In the first case, spectral measurements are possible when filters are used. In the installation based on a CO2 laser, an intense signal is emitted, requiring consideration of sample heating. Components of the installation have been elaborated and investigated, on which transmittance of radiation from the film of ice 0 is planned to be measured.

Banking of AT-MSC and its Influence on Their Application to Clinical Procedures

Processing of MSCs to obtain a therapeutic product consists of two main steps: 1) the in vitro expansion of the cells until an appropriate number of them is obtained, and 2) freezing and storage of the expanded cells. The last step is critical and must be optimized so that after thawing the cells retain all their physiological properties including the secretory function. In this paper, we evaluated physiological parameters of AT-MSC’s after a full cycle of their processing, particularly freezing and storing at the liquid nitrogen vapor temperature. Based on the recovered proliferative and secretory capacities of the thawed cells, we have designed the optimal technique for processing of MSCs for clinical applications. In our work, we tried to select the best DMSO-based cryoprotectant mixture on the base of post thawing fully retain their properties. We have demonstrated the effectiveness of the use of DMSO in various configurations of the constituent cryoprotective fluids. We have also shown that AT-MSCs that show control levels in most standard tests (viability, shape, culture behaviour, and proliferative properties) after thawing, may show transient variations in some important physiological properties, such as the level of secreted growth factors. Obtained results let us to indicate how to optimize the AT-MSC preparation process for clinical applications. We suggest that before their clinical application the cells should be cultured for at least one passage to recover their physiological stability and thus assure their optimal therapeutic potential.

The heat leakage measurement of dewars for infrared detector arrays

Consideration is given to the analysis of a number of implementation of calorimetry method of infrared detector array dewar’s heat leakage measurements. The heat leakage measurements were made both with and without nitrogen vapor heat capacity consideration. The heat exchange process between nitrogen vapor and Dewar’s well walls was analyzed. The most reliable results were achieved by means of approach with calibration.

Cell Viability Assessment Using Fluorescence Vital Dyes and Confocal Microscopy in Evaluating Freezing and Thawing Protocols Used in Cryopreservation of Allogeneic Venous Grafts

The authors present their contribution to the improvement of methods suitable for the detection of the freezing and thawing damage of cells of cryopreserved venous grafts used for lower limb revascularization procedures. They studied the post-thaw viability of cells of the wall of cryopreserved venous grafts (CVG) immediately after thawing and after 24 and 48 h culture at +37 °C in two groups of six CVG selected randomly for slow thawing in the refrigerator and rapid thawing in a water bath at +37 °C. The grafts were collected from multi-organ and tissue brain-dead donors, cryopreserved, and stored in a liquid nitrogen vapor phase for five years. The viability was assessed from tissue slices obtained by perpendicular and longitudinal cuts of the thawed graft samples using in situ staining with fluorescence vital dyes. The mean and median immediate post-thaw viability values above 70% were found in using both thawing protocols and both types of cutting. The statistically significant decline in viability after the 48-h culture was observed only when using the slow thawing protocol and perpendicular cutting. The possible explanation might be the “solution effect damage” during slow thawing, which caused a gentle reduction in the graft cellularity. The possible influence of this phenomenon on the immunogenicity of CVG should be the subject of further investigations.

Supplementation of Pandanus conoideus Oil in Cryopreservation Diluents for Maintaining the Semen Quality of Ongole Grade Bull

Antioxidants such as tocopherol, ß-carotene, and polyunsaturated fatty acids (PUFA) from red fruit oil of Papua may be used to protect frozen semen. The study is aimed to test the effect of red fruit oil supplementation on motility, viability, and recovery rate of frozen sperm of Ongole-grade bulls. Semen was collected twice a month from eight 4-5-year-old male Ongole grade using an artificial vagina, followed by macro- and microscopical evaluations. Collected semen was divided into four tubes and diluted with tris egg yolk diluents (TEY) as a control, TEY supplemented with 0.5% red fruit oil (RFO) (TEY RFO0.5), TEY supplemented with 1% RFO (TEY RFO1.0), and TEY supplemented with 1.5% RFO (TEY RFO1.5). The diluted semen was then packed into the straw and equilibrated for 2, 4, and 6 h prior to frozen on liquid nitrogen vapor for 10 minutes. The observed variables in this study were sperm motility, sperm viability, and morphology after equilibration, after thawing, and recovery rate. The experimental design is a completely randomized factorial design. The data were analyzed using ANOVA and were further tested using Duncan multiple range test. The results showed that the sperm motility of fresh semen was 81.10±1.42%. The percentage of sperm motility in TEY RFO1.5 treatment at 6 h equilibration was 60.00±1.06%, significantly higher compared to TEY RFO1.0 and TEY RFO0.5. The percentage of post-thawing sperm motility in TEY RFO1.5 treatment was 62.40±1.09%. The best post-thawing sperm viability in TEY RFO1.5 was 80.70±1.20%, significantly increase from the treatment of TEY RFO1.0 and TEY RFO0.5. The recovery rate (RR) for TEY RFO1.5 treatment had the best percentage at 76.94%. In conclusion, RFO supplementation in semen diluents for 2 h of equilibration resulted in the best motility and viability at 0 h of post thawing observation.

Peculiarities of Thermodynamic Behaviors of Xenon Adsorption on the Activated Carbon Prepared from Silicon Carbide

An activated carbon prepared from silicon carbide by thermochemical synthesis and designated as SiC-AC was studied as an adsorbent for xenon. The examination of textural properties of the SiC-AC adsorbent by nitrogen vapor adsorption measurements at 77 K, powder X-ray diffraction, and scanning electron microscopy revealed a relatively homogeneous microporous structure, a low content of heteroatoms, and an absence of evident transport macropores. The study of xenon adsorption and adsorption-induced deformation of the Si-AC adsorbent over the temperature range of 178 to 393 K and pressures up to 6 MPa disclosed the contraction of the material up to −0.01%, followed by its expansion up to 0.49%. The data on temperature-induced deformation of Si-AC measured within the 260 to 575 K range was approximated by a linear function with a thermal expansion factor of (3 ± 0.15) × 10−6 K−1. These findings of the SiC-AC non-inertness taken together with the non-ideality of an equilibrium xenon gaseous phase allowed us to make accurate calculations of the differential isosteric heats of adsorption, entropy, enthalpy, and heat capacity of the Xe/SiC-AC adsorption system from the experimental adsorption data over the temperature range from 178 to 393 K and pressures up to 6 MPa. The variations in the thermodynamic state functions of the Xe/SiC-AC adsorption system with temperature and amount of adsorbed Xe were attributed to the transitions in the state of the adsorbate in the micropores of SiC-AC from the bound state near the high-energy adsorption sites to the molecular associates.

Seminal plasma interference in the kinetics and viability of cryopreserved canine sperm

Most researchers have frozen dog semen using methodologies described for other species. Consequently, these studies have shown that the thawed semen of dogs is of low quality, with conception rates lower than that of other species. Therefore, in this study, we evaluated different freezing protocols for canine semen, using three adult Bulldog Campeiro males, aged 2 to 5 years, with proven fertility. Five semen samples were collected from each animal using the penile bulb digital manipulation method. The collected samples were divided into: group 1, the samples were diluted directly in Botudog® commercial freezing medium (Botupharma Biotecnologia Animal) and group 2, the samples were centrifuged at 600 g for 10 min and the pellet was resuspended in Botudog®, totaling a concentration end of 200 x 106 sperm per ml. The samples were packaged in 0.5 mL straws at a concentration of 100 x 106 viable sperm. The samples remained for 1 h in stabilization at 4 °C and transferred to nitrogen vapor for 20 min, immersed in nitrogen, stored in a cryogenic cylinder, and thawed at 46 °C for 20 s. It was found that the total motility (MT, %), path speed (VAP, μm/s), progressive motility (PM, %), progressive linear speed (VSL; µm/s), curvilinear speed (VCL; µm/s), linearity (LIN, %), percentage of fast sperm (RAP, %), and plasma and acrosomal membrane integrity were higher in group 1, with samples not being centrifuged. These data demonstrate that the canine semen freezing protocol, using the Botudog® diluent, does not recommend the centrifugation of the ejaculate, prior to freezing.

QUALITY OF DECONSERVED BULL SPERM AFTER ADDITION OF MICROELEMENTS CONNECTED TO N-DERIVATIVE PEG400 TO DILUENT

The aim of the work was to establish optimal regimes for sperm cryopreservation when using nano-complexes in environments. The effect of micronutrients (Сu2+, Zn2+, Mn2+) in the polymer- transporters on the survival and fertilization capacity of sperm bulls was investigated. To assess the validity of the complexes N-derivative PEG400, ejaculates were chosen with volume – from 2 to 5 ml, concentration - 0,7 - 1,2×109 cells/ml and sperm activity 7.0 - 8.0 points. Sperm diluted with lactose-yolk-glycerin diluent was divided into parts: control - without addition and experimental with the addition of N-derivative PEG400 (N-PEG400) with a content of 1 ml of solution: Zn2+ - 0,0319 mmol; Cu2+ - 0.0222 mmol; Mn2+ – 0.0359 mmol. In the test sperm samples were added 0.01 ml of solutions of microelements in the polymer composition in ml of diluted ejaculate. Sperm survival was determined in sperm survival samples, motility, respiratory activity, activity of enzymes-markers of sperm fertility - succinate dehydrogenase (SDG) and cytochrome oxidase (CHO). It was found that the optimal equilibration time of sperm in the presence of microelements in the diluent of N-derivatives of PEG400 is 2.5 hours. In this case, the activity of sperm in the presence of N-derivatives of PEG400 depends on the exposure of spermatozoa over nitrogen vapor and the ability of trace elements to affect metabolic processes in sperm. The highest values of the values of the dynamic parameters of sperm characterized deconserved sperm with the addition to the dilution medium of Zn2+ and Mn2+ N-derivatives of PEG400 and exposure to nitrogen vapors for 8-10 minutes. It was found that Zn2+ and Mn2+ N-derivatives of PEG400 that were added in the diluent after cooled for 8-10 min over nitrogen vapor are characterized by high spermatozoa survival. The results of enzymes-markers activity show that the use of spermatozoa containing PEG400 Zn2+ or Mn2+ N-derivatives after 8-10 min exposure to nitrogen vapor, will ensure fertilization of 65% or more heifers and cows after the first insemination. Studied dose (0.01 ml of 0.0222 mmol solution / ml of diluted semen) of Cu2+ N-PEG400 should not be used in the diluent, when freezing the ejaculate of bulls, as the intensity of oxidative processes was elevated, which was manifested by a decrease in physiological characteristics of germ cells.