Immobilization of β-glucosidase onto mesoporous silica support: Physical adsorption and covalent binding of enzyme

This paper investigates β-glucosidase immobilization onto mesoporous silica support by physical adsorption and covalent binding. The immobilization was carried out onto micro-size silica aggregates with the average pore size of 29 nm. During physical adsorption the highest yield of immobilized β-glucosidase was obtained at initial protein concentration of 0.9 mg ml-1. Addition of NaCl increased 1.7-fold, while Triton X-100 addition decreased 6-fold yield of adsorption in comparison to the one obtained without any addition. Covalently bonded β-glucosidase, via glutaraldehyde previously bonded to silanized silica, had higher yield of immobilized enzyme as well as higher activity and substrate affinity in comparison to the one physically adsorbed. Covalent binding did not considerably changed pH and temperature stability of obtained biocatalyst in range of values that are commonly used in reactions in comparison to unbounded enzyme. Furthermore, covalent binding provided biocatalyst which retained over 70% of its activity after 10 cycles of reuse. [Projekat Ministarstva nauke Republike Srbije, br. III 45021

Investigation of zinc stannate synthesis using photoacoustic spectroscopy

Mixtures of ZnO and SnO2 powders, with molar ratio of 2:1, were mechanically activated for 40, 80 and 160 minutes in a planetary ball mill. The resulting powders were compacted into pellets and non-isothermally sintered up to 1200°C with a heating rate of 5°C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the phase composition. The microstructure of sintered samples was examined by scanning electron microscopy. The photoacoustic phase and amplitude spectra of sintered samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled determination of photoacoustic properties including thermal diffusivity. Based on the results obtained a correlation between thermal diffusivity and experimental conditions as well the samples microstructure characteristics was discussed.

Dermatitis tabanskih jastučića kod komercijalnih brojlera

In the present experiment, the presence of mycological agents in chickens with skin lesions on foot pads was investigated, in order to improve the health of broiler chickens. Foot-pad dermatitis (FPD) is described in the literature as dermatitis caused by multifactor causes. The presence of irritating chemical substances in the litter, genetic predispositions of hybrids, immune suppressive diseases of chickens, as well as the composition of commercial broiler diets that influence the occurrence of wet litter, are proven factors that contribute to a more intensive incidence of foot-pad dermatitis. Foot-pad dermatitis is a condition characterized by lesions on metatarsal and digital ventral skin of poultry feet. It is type of contact dermatitis which in severe cases shows slower weight gain, poor health condition and welfare. Taking into consideration the literature data, chickens reared in closed facilities where the bacterial and mycological agents are present partly in the litter if not properly disinfected, but also in the food or the chicken plumage, we wanted to investigate their presence in the skin of foot pads. The study was focused on incidence of foot-pad dermatitis in 500 one day old broiler chickens of Hubbard genotype, in two feeding (standard/economical) programs for broilers available on our market. Chopped straw was used as litter. At the end of fattening, all chickens were examined for the presence of lesions on the skin of the feet. Total of 39 chickens were allocated to the intensity of the lesion on foot pads rated as 2 (mild) and 3 (severe). In the mycological examination of the 9 samples of autoclaved chicken legs with lesions on the feet, we have isolated and identified the presence of fungi /mould Aspergillus fumigatus. The histopathology investigation, during which the tissue section from mild and severe skin foot pads was collected and stained using Hematoxylin and eosin, revealed the hyperkeratosis, panniculitis, ballooning degeneration and dermis inflammation. No fungal elements were observed in the sections of pads stained with Gomori methenamine silver. Birds are especially susceptible to infection with Aspergillus fumigatus. That species of fungus is also classified as allergenic factor.U ogledu je ispitivano prisustvo mikoloških agenasa kod pilića sa lezijama na koži tabanskih jastučića, u cilju poboljšanja zdravlja brojlerskih pilica. Dermatitis na tabanskim jastučićima (DTJ) je u literaturi multifaktornog porekla. Postojanje iritantnih hemijskih supstanci u prostirci, genetske predispozicije hibrida, imunosupresivne bolesti pilića, kao i sastav komercijalnih smeša za ishranu brojlera koje utiču na pojavu vlažne prostirke, su dokazani faktori koji doprinose intenzivnijoj pojavi DTJ. Imajući u vidu ove podatke iz literature, pilići koji se gaje u zatvorenom prostoru u kome su prisutni bakterijski i mikološki agensi delom u prostirci ako nije na adekvatan način dezinfikovana, u hrani ili na perju pilića, želeli smo da ispitamo njihovo prisustvo u koži tabanskih jastučića. Ispitivanje je bazirano na pojavi DTJ u ogledu 500 jednodnevnih pilića Hubbard genotipa, koji su hranjeni na 2 načina (standardnim/ekonomičnim) krmnim smešama koje su prisutne na našem tržištu. Seckana slama je korišćena kao prostirka. DTJ se karakteriše lezijama na metatarzalnim i digitalnim ventralnim delovima kože tabana živine. To je kontaktni dermatitis koji kod težih slučajeva utiče na prirast, zdravlje i dobrobit. Na kraju tova pilića, svi pilići su pregledani na prisustvo lezija na koži tabana. U ovom radu, ispitano je 39 pilića sa intenzitetom lezija na tabanskim jastučićima. Intenzitet lezija je ocenjen sa 2 (blage) i sa 3 (izražene) lezije. Mikološkim ispitivanjem utvrđeno je prisustvo gljivice/plesni Aspergillus fumigatus, kod 9 autoklaviranih promenjenih pilećih nogica. Histološkim ispitivanjem utvrdili smo postojanje hiperkeratoze, panikulitisa, zapaljenje dermisa i balonirajuću degeneraciju. Nismo utvrdili prisustvo fungalnih elemenata u koži tabana, nakon bojenja Gomory methenamin silver bojenjem. Ptice su posebno osetljive na infekciju A. fumigatus koji je klasifikovan kao alergijski uzročnik

Dermatitis tabanskih jastučića kod komercijalnih brojlera

In the present experiment, the presence of mycological agents in chickens with skin lesions on foot pads was investigated, in order to improve the health of broiler chickens. Foot-pad dermatitis (FPD) is described in the literature as dermatitis caused by multifactor causes. The presence of irritating chemical substances in the litter, genetic predispositions of hybrids, immune suppressive diseases of chickens, as well as the composition of commercial broiler diets that influence the occurrence of wet litter, are proven factors that contribute to a more intensive incidence of foot-pad dermatitis. Foot-pad dermatitis is a condition characterized by lesions on metatarsal and digital ventral skin of poultry feet. It is type of contact dermatitis which in severe cases shows slower weight gain, poor health condition and welfare. Taking into consideration the literature data, chickens reared in closed facilities where the bacterial and mycological agents are present partly in the litter if not properly disinfected, but also in the food or the chicken plumage, we wanted to investigate their presence in the skin of foot pads. The study was focused on incidence of foot-pad dermatitis in 500 one day old broiler chickens of Hubbard genotype, in two feeding (standard/economical) programs for broilers available on our market. Chopped straw was used as litter. At the end of fattening, all chickens were examined for the presence of lesions on the skin of the feet. Total of 39 chickens were allocated to the intensity of the lesion on foot pads rated as 2 (mild) and 3 (severe). In the mycological examination of the 9 samples of autoclaved chicken legs with lesions on the feet, we have isolated and identified the presence of fungi /mould Aspergillus fumigatus. The histopathology investigation, during which the tissue section from mild and severe skin foot pads was collected and stained using Hematoxylin and eosin, revealed the hyperkeratosis, panniculitis, ballooning degeneration and dermis inflammation. No fungal elements were observed in the sections of pads stained with Gomori methenamine silver. Birds are especially susceptible to infection with Aspergillus fumigatus. That species of fungus is also classified as allergenic factor.U ogledu je ispitivano prisustvo mikoloških agenasa kod pilića sa lezijama na koži tabanskih jastučića, u cilju poboljšanja zdravlja brojlerskih pilica. Dermatitis na tabanskim jastučićima (DTJ) je u literaturi multifaktornog porekla. Postojanje iritantnih hemijskih supstanci u prostirci, genetske predispozicije hibrida, imunosupresivne bolesti pilića, kao i sastav komercijalnih smeša za ishranu brojlera koje utiču na pojavu vlažne prostirke, su dokazani faktori koji doprinose intenzivnijoj pojavi DTJ. Imajući u vidu ove podatke iz literature, pilići koji se gaje u zatvorenom prostoru u kome su prisutni bakterijski i mikološki agensi delom u prostirci ako nije na adekvatan način dezinfikovana, u hrani ili na perju pilića, želeli smo da ispitamo njihovo prisustvo u koži tabanskih jastučića. Ispitivanje je bazirano na pojavi DTJ u ogledu 500 jednodnevnih pilića Hubbard genotipa, koji su hranjeni na 2 načina (standardnim/ekonomičnim) krmnim smešama koje su prisutne na našem tržištu. Seckana slama je korišćena kao prostirka. DTJ se karakteriše lezijama na metatarzalnim i digitalnim ventralnim delovima kože tabana živine. To je kontaktni dermatitis koji kod težih slučajeva utiče na prirast, zdravlje i dobrobit. Na kraju tova pilića, svi pilići su pregledani na prisustvo lezija na koži tabana. U ovom radu, ispitano je 39 pilića sa intenzitetom lezija na tabanskim jastučićima. Intenzitet lezija je ocenjen sa 2 (blage) i sa 3 (izražene) lezije. Mikološkim ispitivanjem utvrđeno je prisustvo gljivice/plesni Aspergillus fumigatus, kod 9 autoklaviranih promenjenih pilećih nogica. Histološkim ispitivanjem utvrdili smo postojanje hiperkeratoze, panikulitisa, zapaljenje dermisa i balonirajuću degeneraciju. Nismo utvrdili prisustvo fungalnih elemenata u koži tabana, nakon bojenja Gomory methenamin silver bojenjem. Ptice su posebno osetljive na infekciju A. fumigatus koji je klasifikovan kao alergijski uzročnik

Reintroduction of the European beaver (Castor fiber L.) into Serbia and return of its parasite: The case of Stichorchis subtriquetrus

After becoming extinct in the second half of the 20th century, the European beaver (Castor fiber L., 1758) was successfully reintroduced from Bavaria into Serbia during 2004-2005. In the necropsy of an adult female beaver (found dead in December of 2007), we discovered some parasites identified as Stichorchis subtriquetrus in the colon and peritoneal area. This is the first occurrence of the given specific parasite of beavers in Serbia. Decoding of a subcutaneous implanted microchip has confirmed that our specimen was one of the released beavers. We therefore conclude that the parasite in question was reintroduced into Serbia with the beavers originating from Bavaria.Nakon nestanka u drugoj polovini XX veka, evropski dabar (Castor fiber L. 1758) je tokom 2004-2005. godine, uspešno reintrodukovan sa područja Bavarske u Srbiju. Tokom obdukcije jedne adultne ženke(pronađena mrtva u decembru 2006) pronašli smo parazite u želucu koji su identifikovani kao Stichorchis subtriquetrus. To je prvi nalaz ovog specifičnog parazita dabra u Srbiji. Dekodiranjem subkutano implantiranog mikročipa, potvrđeno je da pronađena ženka jedna od 20 jedinki koje su decembra 2004. godine naseljene na području Specijalnog rezervata prirode Obedska bara. Ova činjenica nam sugeriše da je parazit neželjeno reintrodukovan u Srbiju zajedno sa dabrovima koji su poreklom iz Bavarske naseljavani u Srbiju.Projekat ministarstva br. TR 2001

A Detailed XRD and FTIR Analysis of Bi2O3 Doped ZnO-SnO2 Ceramics

Poster presented at the 2nd International Congress on Ceramics, Verona, Italy, June 29 - July 4, 200

Procena energetskog statusa krava na osnovu telesne kondicije i parametara metaboličkog profila

The aim of this study was to assess the significance of body condition scoring and metabolic profile test for estimation of energy status of healthy high-yielding dairy cows. Twenty one healthy cows (primiparous and secundiparous) were divided into three groups: dry cows, early puerperal cows and early lactating cows. Cow's energy status was estimated by the analysis of blood samples for beta-hydroxybutirate (BHBA) and glucose. Additionally, urea, total bilirubine and total protein were measured in blood serum samples. According to body condition scores (BCS) results dry cows were overweight (4.03±0.29 points). Immediately after calving, cows lost their weight significantly, since BCS was 2.85±0.46 points at puerperal period and 3.12±0.33 points at day 60 of lactation (p lt 0.001 compared to dry period, respectively). Glucose concentration did not change significantly between dry and puerperal period, while BHBA increased significantly (0.46±0.14 mmol/l at dry period to 1.08±0.21 mmol/l at puerperal period; p lt 0.001). Urea concentration did not change significantly during examined period. Total bilirubin concentration significantly increased from dry (6.31±0.37 mmol/l) to puerperal period (7.63±2.52 mmol/l; p lt 0.001 compared to dry period) and remained high until day 60 of lactation (7.62±0.13 mmol/l; p lt 0.001 compared to dry period). Total protein concentration decreased from dry to puerperal period (69.59±6.14 g/l to 58.87±3.29 g/l; p lt 0.001). According to obtained results it can be concluded that cows were not in adequate energy status during transition period. Our results also indicate that, body condition scoring, BHBA and total bilirubin concentrations can be used as reliable indicators of cow's energy status even when there are not clinically visible health disorders.Cilj istraživanja bio je da se ukaže na značaj metaboličkog profila i telesne kondicije u oceni energetskog statusa visoko-mlečnih krava holštajn rase. Za ispitivanje su odabrane tri grupe po sedam krava. Uzorci krvi uzimani su u zasušenju (15 dana pre očekivanog teljenja), ranom puerperijumu (7 dana nakon teljenja) i 60. dana laktacije. U uzorcima sveže krvi određivana je koncentracija glukoze i beta hidroksi-buterne kiseline (BHBA), a u uzorcima krvnog seruma koncentracija ukupnih proteina, ureje i ukupnog bilirubina. Rezultati ocene telesne kondicije pokazuju da su krave u periodu zasušenja preuhranjene (X=4,03±0,29 poena), dok su u puerperijumu (X=2,85±0,46 poena) i 60. dana laktacije (X=3,12±0,33 poena) u značajno slabijoj telesnoj kondiciji (p lt 0,001 u odnosu na zasušenje). Rezultati ispitivanja parametara metaboličkog profila ukazuju da je koncentracija proteina jedino u periodu ranog puerperijuma bila niža od fiziološke vrednosti (X=56,87±3,29 g/l). Koncentracija glukoze nije se statistički značajno menjala tokom ispitivanih perioda, dok je neposredno posle teljenja došlo do značajnog povećanja koncentracije BHBA (p lt 0,001 u odnosu na zasušenje). Uremija u periodu zasušenja (X=7,73±2,34 mmol/l), ranom puerperijumu (X=8,07±3,09 mmol/l) i 60. dana laktacije (X=7,41±2,03 mmol/l) bila je veća od gornje fiziološke granice. Koncentracija ukupnog bilirubina u periodu zasušenja je bila značajno niža (p lt 0,001) u odnosu na oba ispitivana perioda nakon teljenja. Na osnovu dobijenih rezultata može se zaključiti da krave nisu adekvatno pripremljene za nastupajuću laktaciju, zbog čega je kod njih došlo do značajnog odstupanja u telesnoj kondiciji i vrednostima parametara metaboličkog profila. Ova odstupanja ukazuju na nedovoljnu sposobnost životinja da se prilagode u uslovima negativnog bilansa energije na početku laktacije

Thermal diffusivity of single crystal Bi0.9Sb0.1

A single crystal Bi0.9Sb0.1 ingot was synthesized using the Bridgman technique. Thermal diffusivity and electronic transport properties of single crystal cleaved plates (00l) were determined from PA photoacoustic phase and amplitude spectra obtained using the photoacoustic method with a transmission detection configuration. Both the PA phase and amplitude were measured versus the modulation frequency and numerically analyzed. EDS analyses done to determine chemical composition of the studied samples as well as to check sample homogeneity. Hall effect measurements data were used for the photoacustic measurements

Far infrared properties of sintered PbTe doped with boron

Far infrared spectra of sintered PbTe doped with boron were analyzed. The measured infrared spectra were fated using a modified plasmon-phonnon interaction model with two additional oscillators (at about 195 cm(-1) and 285 cm(-1)) representing local B-impurity modes. The obtained results were compared with previously published data for a single crystal PbTe sample doped with boron

Reintroduction of the European beaver (Castor fiber L.) into Serbia and return of its parasite: The case of Stichorchis subtriquetrus

After becoming extinct in the second half of the 20th century, the European beaver (Castor fiber L., 1758) was successfully reintroduced from Bavaria into Serbia during 2004-2005. In the necropsy of an adult female beaver (found dead in December of 2007), we discovered some parasites identified as Stichorchis subtriquetrus in the colon and peritoneal area. This is the first occurrence of the given specific parasite of beavers in Serbia. Decoding of a subcutaneous implanted microchip has confirmed that our specimen was one of the released beavers. We therefore conclude that the parasite in question was reintroduced into Serbia with the beavers originating from Bavaria.Nakon nestanka u drugoj polovini XX veka, evropski dabar (Castor fiber L. 1758) je tokom 2004-2005. godine, uspešno reintrodukovan sa područja Bavarske u Srbiju. Tokom obdukcije jedne adultne ženke(pronađena mrtva u decembru 2006) pronašli smo parazite u želucu koji su identifikovani kao Stichorchis subtriquetrus. To je prvi nalaz ovog specifičnog parazita dabra u Srbiji. Dekodiranjem subkutano implantiranog mikročipa, potvrđeno je da pronađena ženka jedna od 20 jedinki koje su decembra 2004. godine naseljene na području Specijalnog rezervata prirode Obedska bara. Ova činjenica nam sugeriše da je parazit neželjeno reintrodukovan u Srbiju zajedno sa dabrovima koji su poreklom iz Bavarske naseljavani u Srbiju.Projekat ministarstva br. TR 2001