Strateški pristup suzbijanju krađa vozila (studija slučaja)

Strateški pristup suzbijanju krađa vozila (studija slučaja

"Thermal diffusivity and electron transport properties of NTC samples obtained by photoacoustic method

Poster presented at the Seventh Yugoslav Materials Research Society Conference - YUCOMAT 2005, Herceg Novi, Crna Gora, September 12-16, 2005

Enzymes as a platform for drug development

Polyoxometalates are negatively charged polyanions containing early transition metal ions in their high oxidation state surrounded by bridged oxygen. Firstly, these metal-based clusters were used as promising agents in electron-dense imaging, separations, catalysis, and analysis. In recent years, numerous studies in vitro and in vivo found that these nanocomplexes possess a variety of biological effects including antidiabetic, anticancer, and antibiotic actions. Despite these observed properties, the mechanism of their biological activities has not been completely elucidated so far. On the other hand, the results of enzymatic studies revealed their inhibiting influence on physiologically important extracellular enzymes such as phosphatases, esterases, and ecto-nucleotidases, which are considered target enzymes for the approved biological actions. Accordingly, the overview of the in vitro influence of selected polyoxo-vanadates, -tungstates, and – palladates on cholinesterase, ATPase, and phosphatase activities will be given in this presentation. Cholinesterases, enzymes located on the postsynaptic plasma membrane, have a key role in nerve impulse transmission and were confirmed as the targets of drugs for neurological diseases, which are regularly used in clinical practice. Moreover, ATPases and phosphatases were found to be included in the proliferation and migration of tumor cells, thus the inhibition of these enzymes was found as the mechanism of some anticancer drug actionSimpozijum „Stremljenja i novine u medicini“ Medicinskog fakulteta u Beogradu, Beograd, 04-08. decembra, 2023

Thermal diffusivity of sintered 12CaO-7Al2O3

The thermal diffusivity and some electrical transport properties of sintered 12CaO-7Al2O3 were determined using a photoacoustic method with a transmission detection configuration. The thermal diffusivity, coefficient of carrier diffusion and the surface recombination velocities were determined by fitting experimental spectra and theoretical photoacoustic amplitude and phase signals

SEISMIC DAMAGE MITIGATION OF THE GLAZED BUILDING FACADE

Glass as a material in architecture and civil engineering represents a challenge, and it is often a material of choice for designers, used both for the  the building interior elements as well as for cladding of building. The paper has addressed specifically the glazed curtain wall façades and the earthquake-induced issues related to them. A review of the standing standards and practice in this field are provided. The paper presents some of contemporary solutions for damage mitigation of glazed building envelopes caused by earthquakes, such as: solutions with clearances between glass and its frame, earthquake-isolated curtain wall system, modified geometry of glass corners and friction damping connectors

Investigation of sintering kinetics of NiO using photo acoustic spectroscopy

Sintering kinetics of NiO was investigated using photo acoustic spectroscopy This method was used to follow the change of phase and amplitude of the photo acoustic signal of nickel-oxide samples sintered at 1373 K for 15-240 min. as a function of modulation frequency of the laser beam. Fitting of experimental data enabled determination of photo acoustic properties including thermal diffusivity of sintered nickel-oxide. Analysis of the change of sample density during sintering showed that the sintering process of this material can be observed from the view

"Thermal diffusivity and electron transport properties of NTC samples obtained by photoacoustic method

Poster presented at the Seventh Yugoslav Materials Research Society Conference - YUCOMAT 2005, Herceg Novi, Crna Gora, September 12-16, 2005

U susret pravilnom određivanju veličine nanostruktura: analiza uticaja uslova merenja i pripreme uzorka na razultate procene veličine nanokapi i nanočestica

Physicochemical properties of many active ingredients jeopardize their pharmacological activity. To overcome identified obstacles, nanosystems as carriers for delivery of actives have been recognized as promising tools, with highly posted expectations. The nanotechnology-based approach in drug formulation is much more than just another step in size miniaturization. Given the complexity of nanosystems, challenges encountered in their characterization, and evident lack of testing protocols, relevant European research/regulatory bodies have issued guidelines, summarizing important parameters for nanosystem characterization. Size/size distribution (per se and in biorelevant environment) are essentially important, representing critical quality attributes (1). The aim was to show how significantly different results could be obtained under different measurement conditions/sample preparation methods, offering optimal protocol for size estimation applying dynamic light scattering (DLS), with complementary analysis through atomic force microscopy. Hydrophilic nanoemulsion and aqueous dispersion of polymeric nanoparticles were used as test samples. Ultrapurified water, phosphate buffer saline (PBS, pH 7.4) and biorelevant medium with serum proteins were used for dilution. Measurements were performed applying batch-mode DLS (ZetasizerNano), and AutoProbe CP-Research microscope. Significant differences in obtained nanodroplet/nanoparticle size were observed depending on the type of medium and dilution level. Protein corona formation could not be confirmed with certainty. Preference was given to PBS as dispersant. The optimal level of dilution for nanoparticles was 1:10 (Z‐ave=59.16±0.46nm), and for nanoemulsion 1:100 (Z‐ave=73.5±0.75nm). For proper interpretation, it is necessary that the DLS measurement report, in addition to the Z‐ave and the polydispersity index, contains at least the data on the attenuation and correlation function intercept.Fizičkohemijske osobine mnogih aktivnih supstanci otežavaju ostvarivanje farmakoloških efekata. Kako bi se identifikovane prepreke prevazišle, visoka očekivanja postavljena su pred nanosisteme - nosače za isporuku aktivnih supstanci, uz značajna ulaganja u njihov razvoj. Nanotehnološki pristup formulaciji leka mnogo je više od pukog smanjenja veličine. Imajući u vidu kompleksnost nanosistema, izazove koji se sreću u njihovoj karakterizaciji, te evidentan nedostatak protokola ispitivanja, relevanta evropska istraživačka/regulatorna tela izdala su vodiče, sumirajući značajne parametre karakterizacije nanosistema. Veličina/distribucija veličina (per se i u biorelevantnim uslovima) od suštinske su važnosti za postizanje očekivanih performansi, predstavljajući kritične atribute kvaliteta (1). Cilj rada bio je pokazati kako se pri različitim uslovima merenja/načinima pripreme istog uzorka dobijaju značajno različiti rezultati procene veličine, te ponuditi optimalan protokol merenja dinamičkim rasipanjem svetlosti (DLS), uz komplementarno ispitivanje mikroskopijom atomskih sila. Kao test uzorci korišćeni su hidrofilna nanoemulzija i vodena disperzija polimernih nanočestica, a kao medijumi za razblaživanje visokoprečišćena voda, izotonični fosfatni pufer (PBS, pH 7,4) i biorelevantni medijum obogaćen proteinima seruma. Merenja su sprovedena primenom batch‐mode DLS, (ZetasizerNano), i na mikroskopu AutoProbe CP-Research. Primećene su značajne razlike u vrednostima veličine nanokapi/nanočestica zavisno od tipa medijuma i nivoa razblaženja. Nije se moglo sa sigurnošću potvrditi formiranje protein korone nakon inkubacije u biorelevantnom medijumu. Za procenu veličine per se, prednost je data PBS-u kao disperzantu. Optimalan nivo razblaženja za nanočestice bio je 1:10 (Z‐ave=59,16±0,46nm), a za nanoemulziju 1:100 (Z‐ave=73,5±0,75nm). Radi adekvatnog tumačenja, potrebno je da izveštaj DLS merenja, pored Z-ave i indeksa polidisperznosti, sadrži barem još podatke o atenuaciji i odsečku korelacione funkcije.VIII Kongres farmaceuta Srbije sa međunarodnim učešćem, 12-15.10.2022. Beogra

The biological significance of differences in cows and sows colostrum and milk composition

The objective of this work was to compare the composition of colostrum and milk of cows and sows (content of dry matter, protein, milk fat and lactose, concentration of IGF-I and insulin) in samples taken on the first, second, third and seventh day after parturition, and then based on the differences in composition to determine a biological significance of nutrition of newborn during the earliest stages of their life. The investigation inluded 14 cows of Holstein breed and 14 sows of Landrace breed. The content of dry matter and the concentration of proteins in both colostrum and milk samples were statistically significantly higher in regard to sows mammary glands secretion, taken on the first day after the parturition (p<0,01 and p<0,001, individually), but their decrease in mammary glands secretion was more pronounced in the cows than the sows, during the first seven days. The concentration IGF-I was statistically significantly higher in the cows colostrum and milk in regard to the sows during the whole investigation period, while the concentration of insulin was significantly higher in the sows in regard to the cows during the same period. The concentrations of milk fat and lactose in cows milk samples were significantly lower in regard to the sows in all period of the study. On the basis of the obtained results, it can be concluded that there are significant differences in the composition of milk and colostrum of both the investigated animal species. The differences are probably the result of evolutionary adaptation of mammal gland function to nutrition, energy and protection requirements of these young animals in their early postnatal life. [Projekat Ministarstva nauke Republike Srbije, br. III 46002

Photoacoustic properties of single crystal PbTe(Ni)

Single crystals of PbTe(Ni) were investigated by the photoacoustic method. They were produced using the Bridgeman method. These crystals have a sodium chloride cubic lattice and could be cleaved paralel to the plane orientation (200). They were of the n-type. Phase and amplitude photoacoustic spectra were measured using a transmision detection configuration set-up. Photoacoustic (PA) spectra (single and normalized) were numerically analyzed using the Rosencwaig-Gersho model. Thermal diffusivity and some electron-transport parameters were determined. These results were compared with existing results for pure single crystal PbTe. Thermal difusivity of PbTe(Ni) is a bit higher than the thermal difusivity of pure PbTe. This is the consequence of a decreasing concentration of the majority free carriers in the doped alloy