135 research outputs found
Impact of IT on management and humans in modern conditions
The introduction of IT changes the organizational structure and all the elements of management processes, particularly the way we manage organizations. The problem is the fact that information technology is not adequately implemented in all the parts of the business
process. Specifically, it is applied to the operatively executive, administrative, accounting jobs, archiving, retrieval and selection of data for planning and analysis, and its implementation is lagging behind in
leadership and management.
This paper aims to highlight the impact of IT on the management process, i.e. on people as the most valuable potential of each organization
Rolling stock doorways compatibility with platforms at Serbian Railways
Rad prikazuje neke poteškoće koje imaju putnici pri ulasku u voz. Prikazane su i razmotrene visine perona prema međunarodnim železničkim propisima. Dat je pregled visine perona na srpskim prugama i visine poda putničkih kola, dizel i električnih višedelnih jedinica za prigradski i regionalni saobraćaj. Rad se fokusira na razlikama između politike nabavke, u odnosu na kompatibilnost ulazišta sa peronima, dizel i električnih višedelnih jedinica Železnice Srbije i posledicama ovih nabavki.This paper shows some of the passenger difficulties when boarding trains. Overview of platform heights is discussed in accordance with international railway regulation. An overview of platform heights at Serbian railway lines and floor heights of passenger coaches, diesel units and electric multiple units for suburban and regional railway transport are shown. This paper is focused on the differences between procurement policy, regarding doorway compatibility with platforms, of diesel and electric multiple units for Serbian Railways and consequences of these acquisitions
Origin of rat β-globin haplotypes containing three and five genes
We have reported in rat three adult β-gene haplotypes containing either five or three genes. Detailed sequence analysis reveals that the leftmost gene is the major gene and that at the opposite end downstream lies the minor gene. All of the genes lying between them are minor-major hybrids indicating their origin by unequal crossing-over. In two haplotypes β-globin genes were found with an L1 element inserted directly into IVS2. The described results allow the formulation of a pathway of mutational events leading from the ancient two-β-gene rodent ancestor through a three-gene haplotype to five-gene haplotypes, one of which is postulated to have arisen in common laboratory strains since their capture in the wild.[https://academic.oup.com/mbe/article/7/5/407/1061225
Comparison of Box-Behnken, Face Central Composite and Full Factorial Designs in Optimization of Hempseed Oil Extraction by n-Hexane: a Case Study
Statistical multivariate methods like Box-Behnken, face central composite and full factorial designs (BBD, FCCD and FFD, respectively) in combination with the response surface methodology (RSM) were compared when applied in modeling and optimization of the hempseed oil (HSO) extraction by n-hexane. The effects of solvent-to-seed ratio, operation temperature and extraction time on HSO yield were investigated at the solvent-to-seed ratio of 3:1, 6.5:1 or 10:1 mL/g, the extraction temperature of 20, 45 or 70 °C and the extraction time of 5, 10 or 15 min. All three methods were efficient in the statistical modeling and optimization of the influential process variables and led to almost the same optimal process conditions and predicted HSO yield. Having better statistical performances and being economically advantageous over the FFD with repetition, the BBD or FCCD combined with the RSM is recommended for the optimization of liquid-solid extraction processes
Seroprevalence of Actinobacillus pleuropneumoniae in swine originated from commercial farms in Serbia
Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae (A.pleuropneumoniae) is one of the most important respiratory diseases of pigs and causes worldwide severe losses in pig farming. For A.pleuropneumoniae control and monitoring, the detection of ApxIV antibodies in the serum is the most frequently used serological method. The aim of this study was to investigate presence of antibodies against A. pleuropneumoniae in blood sera of gilts and sows using the ELISA test. Samples were taken from gilts and sows originating from four commercial swine farms in Serbia. For detection of ApxIV antibodies, commercial ELISA kit was used. A total of 453 blood sera samples of gilts (207) and sows (246) were examined. Antibodies against A. pleuropneumoniae were detected in 57 (12.58%) sera. Antibodies were present in 22 (10.62 %) sera of gilts and in 35(14.22%) sera of sows. Percentage of positive sera differed among the farms, ranging in gilts from 3.33-17.77 % and in sows from 8.95-22.64%. Serological methods is one of the most important procedures in the diagnosis of porcine pleuropneumonia particularly suitable for the control of animal health status in a large breeding
Cloning and expression of fluorescently labeled )-synuclein in Eschierichia coli
Fluorescentno obeleženi proteini su neprocenjivi alati u laboratorijskoj praksi za in vivo lokalizovanje i ispitivanje interakcija proteina. Dizajnirali smo vektor za ekspresiju mCerulean3 sa N-terminalnim heksahistidinskim obeleživacem fuzionisanim preko poliasparaginskog linkera i proteolitickog mesta za proteazu virusa graviranosti duvana (TEV) sa -sinukleinom. Ovaj konstrukt može se upotrebiti za proizvodnju -sinukleina nativne sekvence nakon proteolize TEV proteazom. Gen za mCerulean3 je nizom lancanih reakcija polimeraze (SOEing PCR) fuzionisan sa genom za -sinuklein i nakon amplifikacije ukloniran u plazmid pDUET-1. Escherichia coli BL21(DE3) je, nakon transformacije ovim konstruktom, upotrebljena za proizvodnju himernog proteina koji je zadržao fluorescentna svojstva sa prinosom od ~2 mg po litru medijuma nakon precišcavanja imobilizovanom metal-afinitetnom hromatografijom (elektroforetska cistoca: ~80%). Ovaj himerni protein je uspešno proteolizovan TEV proteazom.Fluorescently labeled proteins are invaluable tools in laboratory practice to assess the in vivo localization and the interactions of proteins. Here we have designed an expression vector with an N-terminal hexahistidine-tagged mCerulean3 fused through a polyasparagine linker and the proteolytic site of tobacco etch virus protease (TEV) to - synuclein. This construct can be used to produce -synuclein of a native sequence after proteolysis with TEV protease. After fusion of the genes for mCerulean3 and -synuclein through a series of polymerase chain reactions (SOEing PCR), the resulting gene for the chimeric protein was cloned into the pDUET-1 plasmid. Escherichia coli BL21(DE3), upon transformation with this construct, can be used to produce the chimeric protein that retained the fluorescent properties of mCerulean3, with a yield of ~2 mg per liter of medium after purification by immobilized metal-affinity chromatography (electrophoretic purity: ~80%). This chimeric protein was successfully proteolyzed by TEV protease.Poster: [https://cherry.chem.bg.ac.rs/handle/123456789/5374
Cloning and expression of fluorescently labeled )-synuclein in Eschierichia coli
Fluorescentno obeleženi proteini su neprocenjivi alati u laboratorijskoj praksi za in vivo lokalizovanje i ispitivanje interakcija proteina. Dizajnirali smo vektor za ekspresiju mCerulean3 sa N-terminalnim heksahistidinskim obeleživacem fuzionisanim preko poliasparaginskog linkera i proteolitickog mesta za proteazu virusa graviranosti duvana (TEV) sa -sinukleinom. Ovaj konstrukt može se upotrebiti za proizvodnju -sinukleina nativne sekvence nakon proteolize TEV proteazom. Gen za mCerulean3 je nizom lancanih reakcija polimeraze (SOEing PCR) fuzionisan sa genom za -sinuklein i nakon amplifikacije ukloniran u plazmid pDUET-1. Escherichia coli BL21(DE3) je, nakon transformacije ovim konstruktom, upotrebljena za proizvodnju himernog proteina koji je zadržao fluorescentna svojstva sa prinosom od ~2 mg po litru medijuma nakon precišcavanja imobilizovanom metal-afinitetnom hromatografijom (elektroforetska cistoca: ~80%). Ovaj himerni protein je uspešno proteolizovan TEV proteazom.Fluorescently labeled proteins are invaluable tools in laboratory practice to assess the in vivo localization and the interactions of proteins. Here we have designed an expression vector with an N-terminal hexahistidine-tagged mCerulean3 fused through a polyasparagine linker and the proteolytic site of tobacco etch virus protease (TEV) to - synuclein. This construct can be used to produce -synuclein of a native sequence after proteolysis with TEV protease. After fusion of the genes for mCerulean3 and -synuclein through a series of polymerase chain reactions (SOEing PCR), the resulting gene for the chimeric protein was cloned into the pDUET-1 plasmid. Escherichia coli BL21(DE3), upon transformation with this construct, can be used to produce the chimeric protein that retained the fluorescent properties of mCerulean3, with a yield of ~2 mg per liter of medium after purification by immobilized metal-affinity chromatography (electrophoretic purity: ~80%). This chimeric protein was successfully proteolyzed by TEV protease.Abstract: [https://cherry.chem.bg.ac.rs/handle/123456789/5373
Analysis of PET degrading enzymes by bioinfomatic tools
PET hydrolases are enzymes that have been shown to act upon PET as a substrate. Theseenzymes usually adopt an α/β hydrolase fold and are from the classes of esterases, lipases,cutinases, and hydrolases.Here, we have done sequence alignment by ClustalW of the sequences corresponding tothe entries available in the PAZy database (pazy.eu) with the addition of a highly efficientI. sakaiensis PETase mutant W159H/S238F and analyzed the results. The aligned sequencesincluded several different well-aligned segments, which were as follows: 18 single-amino acidsegments, 13 two-amino acid segments, 10 three-amino-acid segments, 1 four-amino acidsegment, 1 six-amino acid segment and 1 eight-amino acid segment. Additionally, at position238, which is adjacent to a highly conserved His237, the most common amino acids wereF,T, S, Y, W, L and G, whereas at position 159, the most common amino acids were W, H, I andL, flanked by a conserved three- and eight-amino acid region. These positions seem to becritical for the improvement of the PET hydrolytic activity based on the comparison ofI. sakaiensis PETase mutant W159H/S238F and wt enzyme.Using AlphaFold 2.0 we have predicted the structures of all enzymes available in the databasewhose structures haven't been previously reported and the presence of the α/β hydrolasemotif has been observed. The sequences were also analyzed by SIAS (imed.med.ucm.es).Abstract: [https://cherry.chem.bg.ac.rs/handle/123456789/5971
Analysis of PET degrading enzymes by bioinfomatic tools
PET hydrolases are enzymes that have been shown to act upon PET as a substrate. These
enzymes usually adopt an α/β hydrolase fold and are from the classes of esterases, lipases,
cutinases, and hydrolases.
Here, we have done sequence alignment by ClustalW of the sequences corresponding to
the entries available in the PAZy database (pazy.eu) with the addition of a highly efficient
I. sakaiensis PETase mutant W159H/S238F and analyzed the results. The aligned sequences
included several different well-aligned segments, which were as follows: 18 single-amino acid
segments, 13 two-amino acid segments, 10 three-amino-acid segments, 1 four-amino acid
segment, 1 six-amino acid segment and 1 eight-amino acid segment. Additionally, at position
238, which is adjacent to a highly conserved His237, the most common amino acids were
F,T, S, Y, W, L and G, whereas at position 159, the most common amino acids were W, H, I and
L, flanked by a conserved three- and eight-amino acid region. These positions seem to be
critical for the improvement of the PET hydrolytic activity based on the comparison of
I. sakaiensis PETase mutant W159H/S238F and wt enzyme.
Using AlphaFold 2.0 we have predicted the structures of all enzymes available in the database
whose structures haven't been previously reported and the presence of the α/β hydrolase
motif has been observed. The sequences were also analyzed by SIAS (imed.med.ucm.es).Poster: [https://cherry.chem.bg.ac.rs/handle/123456789/5972
Nanostructured SnO2 thick films for gas sensor application: analysis of structural and electronic properties
This research is focused on structural and electrical characterisation of tin oxide (SnO2) applied as a thick film and investigation of its properties as gas sensitive material. Micron sized SnO2 powder was milled in an agate mill for six hours to fabricate SnO2 nanopowder, which was afterwards sieved by 325 mesh sieve and characterized by XRD and SEM. This powder was used as functional part in the production of thick film tin oxide paste containing a resin vehicle with 4 wt. % nanosize glass frits acting as permanent binder. The glass frits where additionally milled for twelve hours in the agate mills to nanosized powder and sieved by a 325 mesh sieve as well. The achieved thick film paste was screen printed on alumina and fired at 850oC peak temperature for 10 minutes in air. After the sintering process, thick film samples where characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The reflectivity was measured on the same samples by UV-VIS spectrophotometer: the band gap was determined from the slope of reflectance. After that a matrix of different interdigitated electrode structure of PdAg paste was printed and sintered using the mentioned sintering conditions. The tin oxide thick film was printed over the interdigitated electrodes as a top layer and sintered again under the same conditions. The total electrical resistance was measured as a function of the electrode spacing and temperature. A negative temperature coefficient (NTC) was identified and measured in the range from room temperature (27°C) to 180°C in a climate chamber. Finally the samples were placed into a gas reactor with NOx and CO gas and the resistance was measured in the same temperature range (27°C-200°C)
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