Evaluation of developmental competence of Sus scrofa domesticus (L.) oocyte-cumulus complexes after intra- and extraovarian vitrification

The aim of the present study was to identify the influence of extra- (EOV) and intraovarian vitrification (IOV) on mitochondrial activity (MA) and chromatin state in porcine oocytes during maturation in vitro. During EOV porcine oocytes were exposed in cryoprotective solutions (CPS): CPS-1 – 0.7 M dimethyl sulfoxide (DMSO)+0.9 M ethylene glycol (EG); CPS-2 – 1.4 M DMSO+1.8 M EG; CPS-3 – 2.8 M DMSO+3.6 M EG+0.65 M trehalose. At IOV the ovarian fragments were exposed in CPS-1 – 7.5 % EG+7.5 % DMSO, then in CPS-2 – 15 % EG, 15 % DMSO and 0.5 M sucrose. Straws with oocytes and ovarian fragments were plunged into LN2 and stored. For devitrification, the EOV oocytes were washed in solutions of 0.25, 0.19 and 0.125 M of trehalose, the IOV – in 0.5 and 0.25 М trehalose. Oocytes were cultured in NCSU-23 medium with 10 % fluid of follicles, follicular walls, hormones. 0.001 % of highly dispersed silica nanoparticles (ICP named after A.A. Chuyko of the NAS of Ukraine) were added to all media. The methods of fertilization and embryo culture are presented in the guidelines developed by us. MA and chromatin state were measured by MitoTracker Orange CMTMRos and the cytogenetic method. Significant differences in the level of oocytes with high-expanded cumulus between control and experimental vitrified groups (81 % versus 59 % and 52 %, respectively, p ≤ 0.001) were observed. The percentage of pyknotic cells in native oocytes was 19 %, EOV or IOV oocytes were 39 % and 49 %, respectively. After culture, the level of matured native oocytes was 86 %, 48 % EOV and 33 % IOV cells finished the maturation (p ≤ 0.001). Differences were also observed in the level of MA between groups treated by EOV and IOV (89.4±7.5 µA and 149.2±11.3 µA, respectively, p ≤ 0.05). For the first time, pre-implantation embryos were obtained from oocytes treated by IOV.

PROSPECTS FOR THE USING OF SILICON-CONTAINING COMPOUNDS IN THE TECHNOLOGY OF IN VITRO MATURATION OF ANIMAL OOCYTES

In vitro production of animal embryos is an important tool for solving male and female infertility problems in animals. Modeling of extracorporeal maturation systems of oocytes using siliconcontaining compounds in the composition of culture media revealed the peculiarities of the realization of their effects on somatic and germ cells of ovarian follicles, depending on the structure. Highly dispersed silica nanoparticles (nHDS) positive effects on the fertility of female gametes in Bos Taurus and Sus Scrofa Domesticus. The gel substrate of silica (silicon dimethylglycerolate - DMGC) does not cause an increase in the level of embryos cleavage, while it does not have cytoand genotoxicity when tested on somatic and germ cells of antral follicles.Key words: siliconcontaining compounds, in vitro maturation, animal oocytes.

Cullet-Filled Concrete

The paper considers how cullet of different particle-size distribution affects the concrete strength. Experiments have proven that large-particle cullet (1.25 cm or larger) could be used as an aggregate; the concrete strength will be on par with those of ordinary natural/crushed sand concrete. The paper proves the feasibility of injecting highly dispersed silica fume in combination with effective polycarboxylate-based superplasticizers in cullet-based concrete mixtures. Highly dispersed silica fume will positively affect the strength characteristics of concrete, as silica fume in cement rock reacts with Са (ОН)2, which is released upon the hydration of the clinker minerals С3S and С2S; the reaction produces very strong compounds. Concretes containing up to 30% silica fume in combination with a superplasticizer will feature very high early strength. Use of strong aggregates with a 30% cullet content can produce strong concretes; after steamed, a concrete containing silica fume and polycarboxylate-based superplasticizer will reach 90% of the graded strength. Cement-rock microstructure studies show that the polymer component of the STACHEMENT 2280 superplasticizer will gradually transcend from the glass grains to the cement rock. The interface between the polymer-coated glass grains and the cement rock is blurred and barely present. This strengthens the glass-rock adhesion and improves the concrete strength. This is why cullet is recommended for use in the production of curb stones.