In vitro produkcija goveđih embriona

Biotechnology is used for the purpose of improving production, and developing animal and pharmaceutical products. In roder to achieve these objectives, it is necessary to manipulate these processes. Reproductive biotechnology can be used independently, or it can be used in connection with other techniques. Thus, for instance, successful culture of embryos in laboratory conditions is a necessary precondition for the production and creation of transgenic and cloned animals. The in vitro process of embryo production is narrowed down to three basic steps: 1. collecting oocytes form a female donor, 2. fertilization of oocytes under laboratory conditions, 3. growth of the embryo in a medium and transfer of the embryo into the recipient. The paper describes the IVP procedure (in vitro production) of bovine embryos; the advantages and shortcomings of this method, as well as possibilities for its application in cattle breeding. This technology is still quite new, so taht both the technique and the mediums are constantly being improved. The technique of fertilizing bovine oocytes, as well as their development in laboratory conditions was discovered in 1980, and the first calf produced using in vitro fertilization (IVF) was born in 1982. IVP implies a series of steps, and if just one of them is not done perfectly, the result is a small number of embryos, or even none at all.Biotehnologija se koristi radi poboljšanja produkcije, razvoja životinjskih i farmaceutskih produkata. Manipulacija reproduktivnim procesima je neophodna, kako bi se postigli ovi ciljevi. Reproduktivna biotehnologija može nezavisno da se koristi ili je povezana sa drugim tehnikama. Tako je, na primer, uspešna kultura embriona u laboratoriji neophodan preduslov za proizvodnju i stvaranje transgenih i kloniranih životinja. „In vitro” proces produkcije embriona se svodi na tri osnovna koraka: 1. sakupljanje oocita od ženke-donatora, 2. fertilizacija oocita u laboratorijskim uslovima, 3. razvoj embriona u medijumu i transfer embriona u recipienta. U radu je opisan postupak IVP (in vitro produkcija) goveđih embriona, prednosti i nedostaci ove metode, kao i mogućnosti njene primene u stočarstvu. Ova tehnologija je još uvek nova, pa se i tehnika i medijumi konstantno usavršavaju. Tehnika fertilizacije oocita krava, kao i njihov razvoj u laboratorijskim uslovima otkriven je 1980. godine, a prvo tele proizvedeno in vitro fertilizacijom (IVF) rođeno je 1982. godine. IVP podrazumeva niz kompleksnih koraka, a ukoliko jedan od njih nije optimalan, to rezultira pojavom malog broja embriona ili ni jednog

Morfološke, imunofenotipske i kliničke karakteristike limfocitno - plazmocitnog duodenitisa pasa

The most important morphological feature of the immune response in lymphocytic-plasmacytic duodenitis (LPD) in dogs is the presence of a mononuclear infiltrate in the duodenal mucosa. The ethiopatogenesis of this disease is still unknown, nor are known all the immunophenotypic characteristics of the infiltrate cells, which would be of help in the elucidation of the pathogenesis of LPD. The study involved 60 adult dogs of different breeds and both sexes: 54 dogs with symptoms of diarrhea and vomiting that lasted longer than three weeks and six clinically healthy dogs that served as controls. Hematological and biochemical analysis of blood, radiology, ultrasound and endoscopic diagnosis were carried out. Samples of duodenal mucosal biopta were examined by histopathological and immunohistochemical methods. During endoscopic examination, duodenal wall thickening, mucosal edema and hyperemia were observed in 46 dogs. Microscopic studies showed on the epithelial cells of the duodenum degenerative changes, and sometimes desquamation. Most of the intestinal crypts were dilated, irregularly shaped and filled with detritus. On immunohistochemical examination of samples of the duodenum in a number of dogs with LPD a predominant expression of CD3 + T lymphocytes was observed.Najvažnija morfološka karakteristika imunskog odgovora kod limfocitnoplazmocitnog duodenitisa (LPD) pasa je nalaz infiltrata mononuklearnih ćelija krvi u sluzokoži duodenuma. Do danas etiopatogeneza ove bolesti pasa nije u svemu poznata, a nisu poznate ni sve imunofenotipske karakteristike ćelija u infiltratu, koje bi bile značajne za razumevanje etiopatogeneze LPD. Ispitivanjem je bilo obuhvaćeno ukupno 60 odraslih pasa, različitih rasa i oba pola: 54 psa sa simptomima dijareje i povraćanja koje je trajalo duže od tri nedelje i šest klinički zdravih pasa koji su služili kao kontrola. Urađene su hematološke i biohemijske analize krvi, a zatim je sprovedena radiološka, ultrazvučna i endoskopska dijagnostika. Uzorci mukoze duodenuma, uzeti biopsijom, ispitani su histopatološkim i imunohistohemijskim metodama. Pri endoskopskom pregledu, kod 46 pasa je zapažen zadebljali zid duodenuma, hiperemičnost i edem sluznice. Mikroskopskim ispitivanjima, na epitelnim ćelijama duodenuma uočene su degenerativne promene, a nekada i deskvamacija. Većina crevnih kripti je bila dilatirana, nepravilnog oblika i ispunjena detritusom. Imunohistohemijskim ispitivanjem uzoraka duodenuma kod većine pasa sa LPD uočena je dominacija CD3+T limfocita

Reciklaža zauljene otpadne ambalaže procesom pirolize

For commercial packing of lubricants, the most commonly used are polyethylene packing which are different designs and volume. After emptying the contents, used packing ending up as waste material in municipal landfills, and in our environment by irresponsible behavior of users (roadside, forests and rivers). It is known the fact that the polyethylene packing materials and mineral oils are decomposed very slowly. The big problem is the fact that the bottles after emptying the contents, i.e. outflow of lubricants in the passenger vehicles and commercial vehicles, construction and agricultural equipment and chainsaws, drop behind a certain amount of lubricants, which further endanger the environment (particularly water and land), and thus the health of the population. In developed countries there is an organized management, almost of all aspects of polymer waste and used fuel. The collected amount of waste are used for the recovery of polymer materials, for energy, and a variety of chemical products (processes of pyrolysis and gasification). In our country has not established management of collection and disposal of waste yet. Number of passenger vehicles, trucks and other vehicles, as well as to agricultural mechanization are growing, and because of their age or condition of the engine, are increased consumption of motor oil and other liquid lubricants. This leads to the formation of large quantities of waste polyethylene packing in which drop behind a certain amount of lubricants. In this paper are described the results of investigation process of pyrolysis oily polyethylene waste in a laboratory reactor for the purpose of obtaining liquid hydrocarbons. The results of investigation can be used for process design for larger proportion, and the resulting products may have commercial applications. Therefore, this method for oily polyethylene waste has not only environmental, but also economic effect.Za komercijalno pakovanje maziva, najčešće se koristi polietilenska ambalaža različitog dizajna i zapremine. Nakon pražnjenja sadržaja, korišćena ambalaža završava kao otpadni materijal na komunalnim deponijama, a često, neodgovornim odnosom korisnika, završava u našoj okolini (pored saobraćajnica, u šumama i rijekama). Poznata je činjenica da se polietilenski ambalažni materijal i mineralna ulja veoma sporo razgrađuju. Veliki problem predstavlja činjenica da u bocama nakon pražnjenja sadržaja, tj. izlivanja maziva u putničke i teretne automobile, građevinsku i poljoprivrednu mehanizaciju, te motorne pile, zaostaje određena količina maziva, čime se dodatno ugrožava životna sredina (naročito vode i zemljište), a time i zdravlje stanovništva. U razvijenim zemljama EU postoji organizovano upravljanje skoro svim vidovima polimernog otpada, kao i korištenim mazivima. Sakupljene količine otpada koriste se za ponovno dobijanje polimernih materijala, za dobijanje energije, te niza hemijskih proizvoda (procesima pirolize i gasifikacije). U našoj zemlji još nije uspostavljen organizovani način sakupljanja i konačnog zbrinjavanja ovog otpada. Broj putničkih automobila, teretnih i drugih vozila, kao i poljoprivrede mehanizacije je u porastu, a zbog njihove starosti, odnosno stanja motora, povećana je potrošnja motornih ulja i drugih teþnih maziva. To dovodi do nastajanja i veće količine otpadne polietilenske ambalaže u kojoj zaostaje određena količina maziva. U radu su opisani rezultati istraživanja procesa pirolize zauljenog polietilenskog otpada u laboratorijskom reaktoru, u svrhu dobijanja tečnih ugljovodonika. Rezultati istraživanja mogu poslužiti za projektovanje procesa veće razmjere, a dobijeni proizvodi mogu imati komercijalnu primjenu. Zbog toga, ovaj postupak zbrinjavanja zauljenog polietilenskog otpada ima ne samo ekološki, nego i ekonomski efekat

Primena plazme bogate trombocitima u rekonstruktivnoj mukogingivnoj hirurgiji

Introduction Root coverage supported with complete regeneration of lost periodontal tissues represents the ultimate goal of gingival recession treatment. Objective This study was designed to evaluate clinical effectiveness of platelet rich plasma gel (PRP) with connective tissue graft (CTG) in the treatment of gingival recession. METHOD 15 gingival recessions Miller class I or II were treated with CTG and PRP (group PRP). Connective tissue graft was harvested from the premolar region using trap door technique. After elevation of the flap, the regional bone and root surface were smeared with activated PRP gel. CTG was also irrigated with PRP gel before placement over the exposed root surface and local bone. Fixed CTG was covered with a coronally advanced flap. The same number of gingival recessions were treated with CTG in combination with the coronally advanced flap with no PRP gel (group TVT). Clinical recordings included recession depth (RD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KT) before and 1 year after mucogingival surgical treatment. Results Mean value of RD was significantly decreased from 4.93±0.86 mm to 0.60±0.37 (p lt 0.01) with CTG and PRP and from 4.76±0.74 mm to 0.63±0.29 mm (p lt 0.01) in CTG group. This difference was not statistically significant. Results of the keratinized tissue width showed significant increase from 0.88± 0.30 mm presurgery to 3.78±0.49 mm (p lt 0.01) six months after treatment in PRP group and from 0.90±0.34 mm to 3.15±0.41 in TVT group (p lt 0.01). This difference was statistically significant (p>0.05). No statistically significant differences were observed between treatment groups in CAL and PD. Conclusion Clinical results validate both procedures as effective and highly predictable surgical techniques in solving gingival recession problem. Histological evaluation may confirm advantage of PRP use related to regeneration of periodontal tissues.Uvod. Recesija gingive je jedan od najsloženijih problema savremene stomatologije. Iznalaženje novih terapijskih metoda za rešavanje ovog problema je značajan segment istraživanja u parodontologiji. Cilj rada. Cilj rada je bio da se procene klinički efekti primene plazme bogate trombocitima (PBT) u kombinaciji sa transplantatom vezivnog tkiva (TVT) u lečenju recesije gingive. Metod rada. Istraživanje je obuhvatilo 15 bolesnika s obostranim recesijama gingive klase II i III po Mileru (Miller). Metodološki koncept se zasnivao na metodu podeljenih usta. U lečenju 15 recesija primenjen je TVT u kombinaciji sa koronarno pozicioniranim režnjem uz primenu aktiviranog koncentrata trombocita (PBT grupa). Isti broj recesija na suprotnoj strani vilice zbrinjavan je autotransplantatom vezivnog tkiva i periosta u kombinaciji sa koronarno pozicioniranim režnjem (TVT grupa). Za procenu stanja parodoncijuma i efikasnosti primenjenih hirurških postupaka korišćeni su sledeći klinički parametri: vertikalna dubina recesije (VDR), nivo pripojnog epitela i širina keratinizovane gingive. Nivo oralne higijene je utvrđivan plak-indeksom po Silnes- Lou (Silness-Löu), a stanje gingive gingivnim indeksom po Lou-Silnesu (Löu-Silness). Rezultati. Na osnovu analize srednje vrednost za dubinu recesije (VDR), ustanovljeno je statistički značajno smanjenje vrednosti ovog parametra šest meseci posle tretmana u PBT grupi (sa 4,93±0,86 mm na 0,60±0,37 mm; p lt 0,01). U TVT grupi, u kojoj je vrednost VDR pre lečenja bila 4,76±0,74 mm, posle šest meseci dobijena je vrednost od 0,63±0,29 mm (p lt 0,01). U PBT grupi je posle opservacionog perioda zabeleženo proširenje zone keratinizovanog tkiva za 2,90 mm, dok je u istom periodu vrednost ovog parametra u TVT grupi bila 2,25 mm. Poređenjem prosečne promene vrednosti kliničkih parametara u okviru obe eksperimentalne grupe, samo je kod promene širine keratinizovanog tkiva zabeležena statistička značajnost (p lt 0,05). Zaključak. Rezultati ove kliničke studije ukazuju na izuzetnu efikasnost oba primenjena postupka u lečenju recesije gingive

Klinička primena fibrinske membrane u lečenju recesija gingive

Introduction. Fibrin, fibronectin, platelet derived growth factor, and transforming growth factors from platelet concetrate are crucial for tissue reparation and regeneration. Objective. This study was designed to evaluate clinical effectiveness of activated platelet-rich fibrin (PRF) membrane in treatment of gingival recession. Methods. 19 gingival recessions Miller class I or II were treated with a coronally advanced flap and the PRF membrane (PRF group). Following the elevation of the flap, bone and root surfaces were covered with the PRF membrane. After suturing, the PRF membrane was covered with a coronally advanced flap. In the same patients, 19 other gingival recessions were treated with CTG in combination with the coronally advanced flap (the CTG group). Clinical recordings were made of vertical recession depth (VRD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KTW) before and 12 months after mucogingival surgical treatment. Clinical evaluation of healing events was estimated with recordings of the healing index (HI). Recordings of HI were performed in the 1st, 2nd and 3rd week post-surgically. Results. Mean root coverage was significant in both groups (the PRF group 79.94% and the CTG group 88.56% %; p lt 0.01). The difference between the two tested groups was not statistically significant. Results of the keratinized tissue width showed significant increase (p lt 0.05) 12 months after the surgery in both, the PRF and CTG groups. Results of KTW showed statistical significance of recorded differences obtained in the two evaluated groups (p lt 0.05). There was no statistical significance in reduction of PD and CAL recorded in the PRF and CTG groups. The values of HI recorded in the 1st and 2nd week postoperatively were significantly enhanced in the PRF group (p lt 0.05). Conclusion. Results of this study confirm both procedures as effective with equivalence of clinical results in solving gingival recession problems. The utilization of the PRF resulted in a decreased postoperative discomfort and advanced tissue healing.Uvod. Fibrin, fibronektin, faktor rasta poreklom iz trombocita i transformišući faktor rasta imaju presudnu ulogu u regeneraciji i reparaciji tkiva. Cilj rada. Ispitati i utvrditi značaj primene membrane od fibrina bogatog trombocitima (engl. plateletrich fibrin - PRF) u lečenju recesija gingive. Metode rada. Devetnaest obostranih gingivalnih recesija klase I ili II po Mileru lečeno je sa dva različita terapijska modaliteta. U eksperimentalnoj grupi recesija je, nakon odizanja mukoperiostnog režnja, preko izložene alveolarne kosti i korena zuba postavljena PRF membrana kao augmentacioni materijal, koja je zatim pokrivena koronarno pomerenim režnjem. U kontrolnoj grupi su izložena alveolarna kost i koren zuba prekriveni transplantatom vezivnog tkiva (TVT) uz koronarno pomereni režanj. Kod obe grupe recesija posmatrani su sledeći parametri: veličina recesije gingive, širina keratinizovane gingive, nivo pripojnog epitela i dubina sondiranja. Parametri su mereni neposredno pre hirurškog zahvata i 12 meseci kasnije. Zabeležen je i indeks zarastanja rane tokom prve tri nedelje posle operacije. Rezultati. Kod obe grupe recesija postignuto je značajno prekrivanje ogoljenog korena zuba (PRF membrana 79,94% i TVT 88,56%; p lt 0,01), dok između dve ispitivane grupe nije uočena statistički značajna razlika. Rezultati ispitivanja širine keratinizovane gingive su pokazali značajno povećanje u obe ispitivane grupe dvanaest meseci nakon hirurškog lečenja (p lt 0,05). Takođe je uočena statistički značajna razlika između posmatranih grupa (p lt 0,05) kod parametra širina keratinizovane gingive. Statističke značajnosti kada je reč o smanjenju nivoa pripojnog epitela i dubine sondiranja, kako u okviru grupa, tako i između obe ispitivane grupe (p>0,05), nije bilo. Merenjem indeksa zarastanja rane uočeni su značajno bolji rezultati u eksperimentalnoj grupi nakon prve i druge nedelje nego u kontrolnoj (p lt 0,05). Zaključak. Oba postupka pokazala su se adekvatnim u lečenju gingivalnih recesija. U kontrolnoj grupi bili su bolji rezultati u dobitku keratinizovanog tkiva, dok se eksperimentalna procedura pokazala jednostavnijom i komfornijom za samog bolesnika, uz značajno bolji postoperacioni tok

Thermo-mechanical properties of rigid polyurethane foams with cement addition

The parameters of foam preparation, such as addition of fillers, have a significant effect on the properties of polyurethane foams. The goal of this work was to study the effect of the cement addition on the thermo-mechanical properties of rigid polyurethane foams. Isocyanate component was based on polymeric diphenylmethane diisocyanate, and polyol component was polyether type, with addition of castor oil as polyol. It was estimated that the addition of cement increased the values of foam compressive strength and permanent deformation. Compressive strength increased even more than 90% with 20 wt% of cement. Further increase of the cement loading deteriorates the mechanical properties of foamed material because it distorts cellular structures of obtained materials. Addition of cement increased the value of the glass transition temperature of polyurethane foam. The highest increase in the value of glass transition temperature, for 7.5ºC, was achieved by the addition of 20 wt% of cement

Effect of Adsorption Processing of Solvent Base Oils by Activated Bentonite

Solvent base oils of group API I contain larger quantities of aromatic compounds and sulfur, as compared to base oils of higher quality groups. Processing of base oils by commercial clays is performed in order to reduce the content of undesirable compounds, improving the color and oxidation stability. Commercial clays are based on aluminosilicates with a large specific surface area and developed porosity. Bentonite has good adsorption characteristics, which can be further improved by various methods of modification. In this paper, adsorption processing of solvent base oils is derived by acid-activated bentonite and commercial clay. The structural composition of starting oil and refined solvent oil (content of aromatics, paraffins, naphtenes and sulfur) is determined by following methods: IEC 590, UV, IP 346 and BAS ISO 20846. The results showed that processing of a solvent oil by activated bentonite leads to change of structural composition, similar to a change achived by processing with commercial clay

Receptor activator of nuclear factor kappa B (RANK) as a determinant of peri-implantitis

Background/Aim. Peri-implantitis presents inflammatory process that affects soft and hard supporting tissues of osseointegrated implant based on inflammatory osteoclastogenesis. The aim of this study was to investigate whether receptor activator of nuclear factor kappa B (RANK) concentrations in peri-implant crevicular fluid could be associated with clinical parameters that reflect inflammatory nature of peri-implantitis. Methods. The study included 67 patients, 22 with diagnosed peri-implantitis, 22 persons with healthy peri-implant tissues and 23 patients with periodontitis. Clinical parameters from each patient were recorded and samples of peri-implant/gingival crevicular fluid were collected for the enzyme-linked immunosorbent assay (ELISA) analysis. Results. RANK concentration was significantly increased in samples from the patients with periimplantitis when compared to healthy implants (p < 0.0001), where the average levels were 9 times higher. At the same time RANK concentration was significantly higher in periimplantitis than in periodontitis sites (p < 0.0001). In implant patients pocket depths and bleeding on probing values were positively associated with high RANK concentrations (p < 0.0001). Conclusion. These results revealed association of increased RANK concentration in samples of periimplant/ gingival crevicular fluid with peri-implant inflammation and suggests that RANK could be a pathologic determinant of peri-implantitis, thereby a potential parameter in assessment of peri-implant tissue inflammation and a potential target in designing treatment strategies

Magnetic materials, Curie-Weiss law and fractal correction

Neodymium zinc titanate (NZT) is a very attractive perovskite due to its magnetic and dielectric properties. Considering the microstructure influence NZT stability and performance, it is of great importance to establish an approach for the analysis and prediction of grain boundary phenomena. The fractal nature analysis has already proved to be valuable for the reconstruction and prediction of ceramics intergranular electrical properties. However, no researches were performed on the fractal analysis applied on magnetic materials. This method could give an insight in magnetic properties change from the bulk to the grain interface level. In this study, fractal analysis was applied for the Curie-Weiss law correction, introducing fractal correction into magnetic materials for the first time. NZT powders used in this research for fractal analysis were obtained after sintering at different temperatures in the range from 1450°C to 1675°C.Connection between the microstructure fractal nature and the resulting magnetic permeability has been established, enabling the application on different magnetic materials in the future. This creates a foundation for new researches that will lead to further miniaturization of satellite and mobile devices

THERMAL STABILITY AND DAMPING PROPERTIES OF POLYURETHANE HYBRID MATERIAL BASED ON CASTOR OIL

This study reports the fabrication of environmentally friendly polyurethane materials using either 2,4-toluene diisocyanate or isophorone diisocyanate, castor oil as a polyol component, and TiO2 nanoparticles. Samples were prepared with stoichiometric balance of reactive groups. Dynamic viscoelastic properties of prepared samples were studied. The ratio of the loss component to the storage component (tanδ) was used as a measure of the material damping properties. The glass transition temperature was determined as a position of the tanδ curve maximum. The temperature range with tanδ > 0.3 was used to evaluate damping capacity of elastomers. Thermal stability of prepared samples was estimated by TGA method. It was assessed that PU based on aliphatic diisocyanate have higher thermal stability. Obtained values of the glass transition temperature and the starting degradation temperature are important for the application window of novel materials. This study reports the fabrication of environmentally friendly polyurethane materials using either 2,4-toluene diisocyanate or isophorone diisocyanate, castor oil as a polyol component, and TiO2 nanoparticles. Samples were prepared with stoichiometric balance of reactive groups. Dynamic viscoelastic properties of prepared samples were studied. The ratio of the loss component to the storage component (tanδ) was used as a measure of the material damping properties. The glass transition temperature was determined as a position of the tanδ curve maximum. The temperature range with tanδ > 0.3 was used to evaluate damping capacity of elastomers. Thermal stability of prepared samples was estimated by TGA method. It was assessed that PU based on aliphatic diisocyanate have higher thermal stability. Obtained values of the glass transition temperature and the starting degradation temperature are important for the application window of novel material