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In hospitals, veterinary clinics and food processing plants, infectious agents have emerged that are increasingly resistant to applied drugs and disinfection procedures. Therefore, at present it is even more vital to develop and implement new, more effective methods of their inactivation. An example of the most recent solutions in this field is the application of photocatalysis. Among those processes of photocatalysis that have been most studied in the context of their ability to eradicate viruses, prions, bacteria and moulds are TiO₂/UV, ZnO/UV and MgO/UV, where, respectively, titanium dioxide (TiO₂), zinc oxide (ZnO) and magnesium oxide (MgO) are used as photocatalysts after they have been powdered into nanoparticles (NPs), whereby the ultraviolet radiation (UV) is used as an agent generating free radicals. Nano-sized oxides of titanium, zinc and magnesium are applied to create thin photocatalytic films covering various surfaces that thereby display self-disinfecting properties. The susceptibility of infectious agents to photocatalytic processes presents the following order: (viruses = prions) > gram-negative bacteria > gram-positive bacteria > yeasts > moulds. In the light of the most recent studies, photocatalysis seems to be a very promising tool to help overcome problems related to hygiene and public health protection.
The aim of the investigations was to experimentally determine the effect if high ZnO doses, applied in feed, on the clinical condition of experimental piglets and effectiveness of a such procedure for prophylaxis of piglet diarrhoea in the weaning period. 108 Landrace piglets, weaned at the age of 6 weeks, were used for experiments. Out of this group 88 piglets were used for clinical observations and estimation of body weight gains. The remaining 20 piglets were used for laboratory experiments to determine ZnO doses on serum and tissue Zn levels. During the first 63 days daily body weight gains in piglets which were given the feed supplemented with 2500 ppm ZnO were 291 grams. In the controls this value was 285 g. Mean body weight of experimental piglets was 280 g higher on the 63rd day of life than that found in control piglets. In litters of experimental animals which received feed supplemented with 3000 ppm ZnO the mean daily body weight gain was 26 g higher than that in control animals. A favourable effect of Zn addition was found in piglets receiving feed with the addition of 3500 ppm ZnO. Daily weight gains in experimental piglets were 47 g higher than those in control animals. No negative clinical effects were found in experimental piglets receiving increased ZnO doses. Prophylactic application in feed of high ZnO doses (ranging from 2500 to 3500 ppm (2000-2800 ppm Zn)) for 21 days proved to be safe for piglets. The administration of a high level of ZnO for 7 days before weaning and 14 days after weaning decreases the occurence of diarrhoea in the weaning period and limits the reduction of body weight gains caused by diarrhoea. The level of Zn in serum and tissues of 180-day-old slaughtered pigs was similar to those detected in control pigs.
The aim of the study was to determine the effect of adding an antibiotic or zinc oxide together with the feed on the histological picture as well as on the apoptotic and proliferation activity of enterocytes in the mucus of the small intestine of fatteners. The investigations were carried out on 32 crossbred fatteners. The animals were fed in a two-stage system, with the addition of feed antibiotic (control group - C) or with the 0.1-percent addition of zinc oxide (the first stage of fattening; experimental group - E). Samples of small intestine segments (duodenum, jejunum and ileum) were collected post mortem and secured from 16 randomly chosen animals (8 animals from group E and 8 from C) fr histological, histochemical and immuno-histochemical analysis. Staining was conducted using the review method (H-E) and paS-Alcjan. For evaluation of apoptosis and proliferation, the antibodies bax, bcl-x bcl-2 and Ki-67 and PCNA were used. The histological, histochemical and immuno-histochemical evaluation of the mucus of the small intestine of the animals, receiving feed antibiotic or ZnO, showed a comparable influence of the used additives on the morphological traits as well as differentiated the apoptosis and proliferation abilities of the crypt epithelium (cells Ki-67 positive - duodenum and jejunum: P ≤ 0.05 K vs D; PCNA positive duodenum: P ≤ 0.01 K vs D). No negative influence of the zinc oxide additive on the mucus of the small intestine in fatteners was found, which indicates the potential possibility of employing it in the first stage of the fattening period.
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