Low dose gamma-irradiation alters the expression of p53 protein in the rat hippocampus

The tumor-suppressor p53 protein and glucocorticoid receptor (GR) respond to different types of stress. In an attempt to reveal the possibility that p53 protein is involved in the regulation of GR gene expression after low dose cranial irradiation (CI) with 2 Gy, we examined the expression of p53 mRNA and protein as well as expression of GR mRNA and protein in the hippocampus of 18-days-old rats. We found that p53 mRNA expression was unchanged after CI, while induction of p53 protein was rapid, leading to the accumulation of p53 protein in the cytoplasm. Irradiation leads to stimulated GR gene expression in a time-dependent manner, whereas the level of GR protein was unchanged after CI. Co-immunoprecipitation has not showed that wild type p53 protein physically interacts with the GR in the cytoplasm. Our data suggest that the low dose cranial irradiation leads to stabilization of the 53 protein, without interaction with GR protein the cytoplasm.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

New forecasting approach of novel communication services with variable market potential

Predmet istraživanja ove doktorske disertacije je аnаlizа difuzionih modelа nа osnovu koje je predložen i razvijen novi model prognozirаnjа novih servisа sа promenljivim potencijаlom tržištа. Novi model se bazira nа modifikаciji osnovnog Bass-ovog difuzionog modelа u cilju prilаgođenja modelа eksploаtаcionim kаrаkteristikаmа servisа i razvoju neophodne infrastrukture mreže, kao i socio-ekonomskim kаrаkteristikаmа potencijalnog tržišta. Pored rаzvojа novog modelа, dаt je i prikаz postojećih modelа prognozirаnjа dostupnih u stručnoj literaturi. Osnovni cilj disertacije je rešavanje problema prognoziranja brzine difuzije prihvatanja novog komunikacionog servisa, koja zavisi od dinamike razvoja infrastrukture mreže. Ukoliko tehnička podrška novog servisa nije realizovana istovremeno, servis se ne može ponuditi kompletnom tržištu. S obzirom da se proces prihvatanja novog servisa odvija etapno, shodno izgradnji infrastrukture mreže, potencijal tržišta se ne može tretirati kao vremenski nezavisan parametar modela (osnovni nedostatak Bass-ovog modela). Upravo to je i osnovni motiv disertacije – razviti difuzioni model koji potencijal tržišta posmatra kao vremenski zavisnu veličinu, čiju promenu diktira dinamika razvoja infrastrukture komunikacione mreže. Nakon izučavanja različitih difuzionih modela, tehničko-eksploatacionih zahteva novih servisa i socio-ekonomskih indikatora razvoja tržišta, predložen je novi model sa promenljivim potencijalom tržišta. U tezi je primenjena segmentacija tržišta prema socio-ekonomskim karakteristikama korisnika i topologiji terena, kao i simulacija različitih scenarija razvoja u cilju odabira optimalnog pristupa razvoju infrastrukture mreže. Dobijeni rezultati pokazuju da razvoj i implementacija novog modela mogu imati značajnu praktičnu primenu kod telekomunikacionih operatora i servis provajdera, u cilju uspešnog planiranja i projektovanja komunikacione mreže. Adekvatnim planiranjem mreže omogućeno je, kako poboljšanje funkcionisanja same mreže, tako i poboljšanje kvaliteta servisa koji se nudi korisnicima. Takođe, efekti koji se mogu prepoznati ogledaju se i u pravovremenom uvođenju novih servisa, koordinisanoj proizvodnji terminalne opreme, kao i u određivanju i rasporedu potrebne kadrovske strukture...The main research topic of this doctoral thesis is the analysis of new service diffusion forecasting models. Based on this analysis a new diffusion model with variable market potential is proposed. Development of new mathematical model is based on the Basic Bass diffusion model. The aim is to adjust the model to the operational features of services/products and to the socio-economic parameters of the market that drive potential customers. In addition, this thesis considers existing forecasting models available at the literature and the obtained results of the proposed model are compared to the similar forecasting models. This thesis tries to solve the problem of forecasting the adoption of new service that depends on the dynamics of network infrastructure development. If technical support of some new service is not provided in the whole territory, then the service cannot be simultaneously offered to the market. Therefore, the adoption process is performing in steps, following the systematic process of the infrastructure development. The model considers variable market potential that depends on the technical capabilities related to some new telecommunications services. The availability of traffic area infrastructure is increasing during the time according to the infrastructure investment necessity. That is the basic motive of the thesis - developing the diffusion model with variable market potential, caused by dynamics of the network infrastructure development. After researching various diffusion models, as well as technical parameters of the services and socio-economic indicators of the market, an optimal forecasting model is proposed that includes the time varying market potential. This model uses market segmentation and the simulation of various market scenarios in order to indicate effective service rollout. Demand forecasting is required in order to dimensioning of required network resources. Moreover, this model offers the insight into the operator's compromises regarding decisions in the network investment. The resulting plan is a network deployment strategy that defines temporal sequence of network layouts. Thus, the upgrade plan indicates which investments are indispensible at each point of time. The model is of great importance for operators and service providers in decision making and planning, especially in developing countries, as well as in times of economic crisis. It should be noted that the strength of the model lies in its robustness and applicability to real situations that are especially characteristic for the telecommunications market..

Pregled najčešće korišćenih metoda u karakterizaciji alergena

The characterization of an allergen is a troublesome and difficult process, as it requires both the precise biochemical characterization of a (glyco)protein molecule and the establishment of its susceptibility to IgE antibodies, as they are the main link to histamine release in some hypersensitivity states (type I allergies). As the characterization of an allergen includes molecular weight determination of the allergenic molecule, its structure determination, physicochemical properties, IgE binding properties of the allergen molecule, and its allergenicity, an overal review of which biochemical and immunochemical methods are used in achieving this goal are presented in this paper. The information on the molecular level on the stuctures of allergens indicates that allergens are considerably heterogeneous protein structures, and that there is no particular aminoacid sequence which is responsible for the allergenicity. Therefore, information gained from detailed structural, functional and immunochemical studies of these intriguing molecules, which nowadays modulate a variety of pathophysiological conditions, would greatly improve our understanding of the underlying disease mechanisms, and the way to handle them.Okarakterisati alergen je težak i mukotrpan zadatak, jer zahteva preciznu biohemijsku karakterizaciju (gliko)proteinskog molekula, kao i ustanovljavanje njegove sposobnosti da vezuje IgE, jer je to glavna spona ka oslobađanju histamina u nekim stanjima preosetljivosti (alergije tipa I). Karakterizacija alergena podrazumeva određivanje molekulske mase, određivanje strukture, fizikohemijskih svojstava, IgE vezujućih osobina i njegovu alergenost. Ovaj rad daje pregled koje se biohemijske i imunohemijske metode najčešće koriste radi postizanja tog cilja. Informacije koje su do sada dobijene o strukturi alergena pokazuju da su ovi molekuli izuzetno heterogene strukture i da ne postoji određena aminokiselinska sekvencija koja bi mogla da predvidi alergenost datog molekula. Međutim, informacije dobijene iz detaljnih strukturnih studija ovih molekula će doprineti našem razumevanju patofizioloških procesa koji su u osnovi alergijskih oboljenja i unaprediće način na koji ih tretiramo

An assessment of the genetic diversity in the wild boar population from the Podunavlje-Podravlje hunting area

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Different induction of dual corticosteroid receptor system in the rat hippocampus following gamma radiation

Cranial radiotherapy (CRT) is an effective way to prevent CNS relapse in children with acute lymphoblastic leukemia (ALL). However, CRT also has serious side effects on normal tissues, including long-term neuroendocrine disturbances. In order to test this clinical protocol on animals, we examined the effects of CRT (10 Gy) on the level of mRNA for glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) in the hippocampus of 8-days-old rats. Irradiation rapidly stimulated GR gene expression in a time-dependent manner, whereas the time-course of MR mRNA expression showed no statistically significant changes. At postnatal day 42, the level of GR mRNA was diminished while the level of MR mRNA remained unchanged compared to matched controls. Dexamethasone suppression test (DST) revealed the altered nucleocytoplasmic shuttling of activated GR after CRT in 42-days-old rats, as a long-term consequence of gamma irradiation.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Surface ionization study of the non- stoichiometric LnFn-1 (n = 4 – 6) clusters

In this study we are presenting the results of the surface ionization of LinFn-1 (n=4- 6) clusters on rhenium surface impregnated with fullerenes using the magnetic mass spectrometer. The Li5F4 nanocubic cluster was detected for the first time. We determined values of ionization energies for Li4F3 and Li6F5, they are 4,3±0,2 eV, 4,0±0,2eV, respectively. The ionization energies agreed with theoretical ionization energies obtained by ab initio method, which indicates the excess electron localized in a specific site for non-stoichiometric clusters. The first ionization energy value for the Li4F3 was in accordance with earlier results obtained experimentally using photoionization time-of-flight mass spectrometer. There are currently no reliable experimental data for the ionization energy of Li6F5 cluster.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Tribological behaviour of a356/sic nanocomposite

The paper presents tribological behaviour of aluminium nanocomposite A356/SiC produced by the compocasting process with mechanical alloying preprocessing (ball milling). Tribological tests were performed on tribometer with block-on-disc contact geometry under lubricated sliding conditions. Influence of amount of silicon carbide reinforcement (0, 0.2, 0.3 and 0.5 wt.%) on wear rate was investigated in the following testing conditions: sliding speed of 0.25 and 1.0 m/s, normal load of 40 N and 100 N and at sliding distance of 1000 m. Analysis of worn surface of nanocomposites was performed by using SEM equipped with EDS

Tribological behaviour of a356/sic nanocomposite

The paper presents tribological behaviour of aluminium nanocomposite A356/SiC produced by the compocasting process with mechanical alloying preprocessing (ball milling). Tribological tests were performed on tribometer with block-on-disc contact geometry under lubricated sliding conditions. Influence of amount of silicon carbide reinforcement (0, 0.2, 0.3 and 0.5 wt.%) on wear rate was investigated in the following testing conditions: sliding speed of 0.25 and 1.0 m/s, normal load of 40 N and 100 N and at sliding distance of 1000 m. Analysis of worn surface of nanocomposites was performed by using SEM equipped with EDS

Tims and maldi tof of endohedral metallofullerenes

Mass spectral studies (both TIMS – thermal ionization and MALDI TOF – matrix-assisted laser desorption time-of-flight mass spectrometry) of the endohedral metallofullerenes, Li@C60,Li2C70 and 99mTc@C70,provided detailed structural and reactivity information about these unusual species. MS experiment revealed that both fullerenes and endohedral metallofullerenes fragment by multiple C2 loss. However, a difference in the terminal fragmentation products was observed for metallofullerene relative to C60, suggesting that the encapsulation metal strongly impactsthe fragmentation product. Singly charged cations of the metallofullerenes (M@Cn + ) were completely unreactive in the gas phase with oxygenated compounds such as ethylene oxide: however, the corresponding neutral species appear to react readily with oxygenated species. Collisional dissociation of the ionized endohedral fullerenes listed above revealed multiple C2 loss (either as sequential C2 loss or larger C2n eliminations) to generate similar terminal fragmentation products, which might be predicted due to the similar ionic radii of the encapsulated metals. The observed ionization energies of endohedral molecules were 5.9 ± 0.1 eV, 5.3 ± 0.1 eV and 5.7 ± 0.1 eV, respectively.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

ECO-FRIENDLY ELDERBERRY BASED SORBENT FOR REMOVING Pb2+IONS FROM AQUEOUS SOLUTIONS

Abstract Elderberry (Sambucus nigra) pith was modified with polyethyleneimine (PEI) in order to improve the adsorption properties. Characterization of both dried Sambucus nigra pith (DSNP) and amino modification of elderberry pith with branched PEI (PEI/DSNP) was performed by: Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and porosity determination. The amine and ester number, as well as acid value, were determined on DSNP and PEI/DSNP samples using standard volumetric methods. The samples were used as adsorbents for Pb2+ions from an aqueous solution in a batch system. The obtained results were fitted using suitable equilibrium isotherm and kinetic models. The maximum adsorption capacity for Pb2+ions on DSNP andaminаted sample, obtained using Langmuir adsorption isotherm at 298 K, are 18.9 and 47.8 mg g-1, respectively. Based on the kinetic studies, the adsorption process follows the pseudo second-order model. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous. In general, the overall adsorption process was improved by modifying starting material withbranched PEI modifier by introducing large numbers of amino functionalities having high affinity to cations