Pretkoncentracija mikroelemenata iz vode koristeći 4-morfolin ditiokarbamat

The optimum conditions were found for the preconcentration of trace metals in natural waters and model samples with standard metals concentrations by using 4-morpholine dithiocarbamate. The formed complexes were extracted with chloroform. Different methods for recovering the metals from the organic solvent were studied and compared before AAS metal analysis. The developed preconcentration method was successfully applied to the determination of trace metals concentrations in water samples from the "Barje" lake (Leskovac. Yugoslavia).Nađeni su optimalni uslovi za pretkoncentraciju mikroelemenata iz vode koristeći 4-morfolin ditiokarbamat kao kompleksirajući agens. Nagrađeni kompleksi su ekstrahovani hloroformom. Upoređeni su različiti načini ekstrakcije metalnih jona iz organskog rastvarača pre analize atomskom apsorpcionom spektrofotometrijom. Razvijena metoda za pretkoncentraciju uspešno je primenjena za analizu uzoraka vode jezera Barje (Leskovac Jugoslavija)

Self-diffusion of Cd++ Ions in Hydrated CdX Zeolite

The fractional attainment of the isotopic equilibrium between a Cd(N03)2 solution and a 115Cd-labelled CdX zeolite has been measured as a function of time, particle size of zeolite and temperature. The experimental kinetic data have been interpreted in terms of the Brown-Sherry-Krambeck model and the self-diffusivities and diffusional activation parameters of Cd++ ions in zeolite CdX have been calculated

Natural and artificial (90Sr) radionuclides in some carbonated mineral waters used in Serbia

A radiological characterization of 7 different carbonated mineral water samples collected in the local supermarkets in the area of Belgrade (produced in Serbia) was carried out. Analysis included determination of gross alpha and gross beta activities. The obtained results showed that the natural activity concentrations of alpha and beta emitting radionuclides in carbonated mineral water samples were within World Health Organization recommended levels, except for the Heba Strong and Kiseljak samples where the beta activity exceeds 1 Bq/L. For these two water samples gamma spectrometry analysis was performed as well as determination of 90Sr by oxalic method. The instrumentation used to count the gross alpha and gross beta activities, as well as for 90Sr, was a/b low level proportional counter Thermo Eberline FHT 770 T. Gamma spectrometric measurements were performed using a HPGe Canberra detector with a counting efficiency of 20%. The annual effective dose equivalent due to ingestion of investigated waters was calculated for age group >17, and obtained values are lower than 0.1 mSv recommended reference level. Finally, a comparison of the investigated waters with worldwide data was made. [Projekat Ministarstva nauke Republike Srbije, br. III43009

The Impact of One Heat Treated Contact Element on the Coefficient of Static Friction

The subject of the paper includes theoretical considerations, the conducting of experimental tests, and the analysis of exposed test results related to determination of the coefficient of static friction of previously heat-treated contact pairs. One contact element is previously, before the procedure of determining the coefficient of static friction, heated at temperatures in the range of ambient temperature to 280°C and then cooled down to ambient temperature. The results of experimental tests of five different materials show that depending on the heat treatment of one contact element, there is a significant decrease in the coefficient of static friction. The authors of the paper consider that the reasons for the decreasing coefficient of static friction are related to oxide formation and changes in the surface layer of the contact element which is previously heat-treated

Accidental gold-drug poisoning — oral manifestations

Opisuje se slučaj trovanja preparatom zlata bolesnika s reumatoidnim artritisom. Ukazuje se na oralna oštećenja i promene pri trovanju preparatom zlata Solganal B, oleosum. Akcentira se tok trovanja, subjektivne tegobe i klinička slika. Karakteristične su: — Intenzivne primarno bulozno-vezikulozne, sekundarno erozivne promene lokalizovane na pokretnoj sluzokoži oralne duplje i usana. — Hipertrofična gingivna sluzoikoža s ulceronekroznim promenama na interdentalnim papilama. — Izražen ptijalizmus. Učinjen je pokušaj da se ukaže na momente koji diferenciraju trovanje zlatom od ostalih akcidentalnih trovanja.The author describe a case of gold >poiisoning of the patient with rheumatoid arthritis. The oral manifestations of poisoning with gold-drug Solganal B, oleosum are shown. The course of poisoning, symptoms and clinical findings are described. The characteristic clinical findings are: primary severe vesicobullous lesions, secondary erosions localised on mobile mucosa of oral cavity and lips; hyperplastic gingivae with ulcerative and necrotizing lesions on interdental papillae; intensive ptyalism. This study was an attempt to show the differences between the gold-poisoning and other accidental poisonings

Antioxidant Enzymes in Blood of Women With Uterine Hyperplasia

The literature emphasizes the involvement of oxidative stress in the etiopathogenesis of many uterine diseases. Antioxidant system (AOS) represents the protective mechanism used by cells to neutralize overproduced reactive oxygen species (ROS) and prevent oxidative stress. We have previously shown that in gynecological patients with various diagnoses, the reproductive and other factors may be associated with antioxidant capacity and the ability to defend against oxidative damage. In this study, we examined the changes in expression of antioxidant enzymes (AOE): superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) in the blood of women with endometrial hyperplasia. Our results indicate that hyperplasia induces perturbance in oxidative balance, particularly in glutathione redox cycle enzymes

Antioxidant Enzymes in Women with Hyperplasia Complex: Relation with Sex Hormones

Endometrial hyperplasia complex is gynecological disorder characterized by morphological irregularities of glands shape and size. Antioxidant enzymes (AOE), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR), have an essential role in preventing oxidative damage in cell caused by reactive oxygen species (ROS). In this study, we examined the AO status in hyperplastic tissue of patients in menstrual cycle (follicular and luteal phase) and in postmenopause, as well as the relationship between sex hormones and AO parameters. The phase-related activity of GPx and GR in examined patients was significantly different than in healthy women. A significant negative correlation between FSH/LH level and GPx activiy was observed. Endometrial hyperplasias are considered as precancerous lesions and are treated either conservatively or surgicaly, and also by radiation therapy. Since the effects of these therapies are associated with AO and hormonal changes, our results may contribute to the prediction of potential therapeutic efficacy and to selection of the most effective treatment for hyperplasia complex.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Uticaj pentobarbitala i pentilenetetrazola na nivo azot oksida u frontalnom korteksu pacova

Levels of nitric oxide (NO) in the rats frontal cortex were continuously monitored before and after intraperitoneal administration of an antiepileptic drug-pentobarbital (20 and 40 mg/kg) or convulsant drug - pentylenetetrazol (50 mg/kg). Pentobarbital decreased the levels of NO in a dose dependent manner However, NO levels had a tendency to increase following the administration of pentylenetetrazol. It is suggested that central NO participates in the modulation of neuronal excitability, supporting the idea that NO is an important excitatory factor involved in the regulation of seizure susceptibility. Also, our results on anaesthetized rats suggests that endogenous NO may be involved in the mechanism of action of antiepileptic and analeptic drugs and this further suggest that NO levels in the human brain may decrease during antiepileptic therapy and increase during epileptic attacks or administration of excitatory drugs. The aim of the present study was to determine the possible role of NO levels in the brain during neuronal excitability and seizures.Nivo azot oksida (NO) u frontalnom korteksu pacova meren je kontinuirano kako pre, tako i nakon intraperitonealne primene antiepileptika pentobarbitala (u dozi od 20 i 40 mg/kg) ili konvulzivnog agensa pentilenetetrazola (u dozi od 50 mg/kg). Rezultati ovih eksperimenta su ukazali da pentobarbital smanjuje nivo NO u frontalnom korteksu pacova, dok koncentracija NO ima tendeciju rasta nakon primene pentilenetetrazola. Osim toga, dokazano je da endogeni NO ima važnu ekscitatornu ulogu u centralnim mehanizmima nastanka epilepsije. Takođe, naši rezultati su ukazali da kod anestetisanih životinja endogeni nivo NO ima uticaja na dejstvo kako antikonvulzivnih, tako i prokonvulzivnih lekova. Nivo NO u mozgu pacova je bio snižen tokom terapije antiepilepticima, a povišen tokom epileptičkih napada ili primene lekova iz grupe centralnih stimulansa

Procena sadržaja i raspodele teških metala u površinskom sedimentu akumulacije 'Barje' - Srbija

In this study, the nature of the association of heavy metals (Fe, Co, Ni, Cu, Cd, Pb, Mn, and Zn) in sediments of the recent reservoir 'Barje' (Leskovac, Serbia) was investigated. The aim was to make the identification of their substrates, as well as to define the external factors (hydrological and anthropogenic affecting their distribution) which will contribute to a better understanding of the interactions that take place in the reservoir and predict the mobility of the investigated heavy metals. Chemical distribution of heavy metals was tested by using the method of sequential extraction and by data processing using statistical methods such as correlation, cluster and factor analysis. Based on the obtained results it can be concluded that major substrates of heavy metals are in the residual immobile fraction (Fe, Zn and Ni). Since the accumulation has a small organic substance content, Fe and Mn oxides are the most important binding substrates of heavy metals. Although it was determined that lead and cadmium are of the carbonate nature, their concentrations in the reservoir are negligible.Cilj ovog rada je da se ispitivanjem prirode asocijacija teških metala (Fe, Co, Ni, Cu, Cd, Pb, Mn, Zn) izvrši identifikacija njihovih supstrata u akumulaciji 'Barje' (Leskovac, Srbija), kao i da se definišu spoljni faktori (hidrološki i antropogeni koji utiču na njihovu raspodelu) što će doprineti boljem razumevanju interakcija koje se odigravaju u akumulaciji i prognozu mobilnosti na osnovu toga. Hemijska raspodela teških metala ispitana je korišćenjem metode sekvencijalne ekstrakcije i obradom dobijenih podataka statističkim metodama kao što su korelaciona, klaster i faktorska analiza. Na osnovu dobijenih rezultata može se zaključiti da se većina teških metala nalazi u rezidualnoj nepokretnoj frakciji (Fe, Zn i Ni). Zato što je u akumulaciji mali sadržaj organske supstance oksidi gvožđa i mangana su najznačajniji supstrati za vezivanje teških metala. Iako je utvrđeno da je olovo i kadmijum karbonatne prirode njihove koncentracije u akumulaciji su zanemarljivo male

Ispitivanje neurotoksičnosti analoga fentanila kod pacova

This study aimed at evaluating the neurotoxicity of fentanyl analogs: (+/-)-cis-3-carbomethoxy fentanyl (C) and (+/-)-trans-3-carbomethoxy fentanyl (T) in rats. C and Tare less potent (2.4-3.1 and 8.4-12.3 times, respectively) than fentanyl (F) in producing both antinociception and morphine-like neurotoxic effects: loss of pinna reflex, Straub tail, impairment of motor coordination, catalepsy, loss of corneal reflex and loss of righting reflex. All of the effects tested were dose-dependent and they were abolished by pretreatment with naloxone, nonselective antagonist of opioid receptors, indicating that they are mediated via opioid receptors. Further, F, C and T exhibited similar relative potencies in producing all tested effects, indicating that similar receptors are involved in producing antinociceptive and neurotoxic effects, most probably of mu type. By using equiantinociceptive doses, C and T produced significantly shorter duration of both antinociception and neurotoxicity than F No significant differences between therapeutic indices for F, C and T were found, indicating that these compounds are equally safe and tolerable in respect to the neurotoxic effects tested. Neurotoxicity testing presented in this paper may be useful in studying the structure-activity relationship of opioid congeners.Cilj studije bio je da se ispita neurotoksičnost analoga fentanila: (±)-cis-3-karbometoksi fentanila (C) i (±)-trans-3-karbometoksi fentanil (T) kod pacova. C je oko 2,4-3,1, a T oko 8,4-12,3 puta manje potentan od fentanila u izazivanju antinocicepcije i morfinu-sličnih neurotoksičnih efekata u koje spadaju: refleks ušne školjke, Straub-ov rep, poremećaj motorne koordinacije, katalepsija, gubitak kornealnog refleksa i gubitak refleksa uspravljanja. Svi ispitivani efekti su dozno-zavisni i bivaju poništeni ako se u pretretmanu primeni nalokson, neselektivni antagonist opioidnih receptora, što ukazuje da se efekti odigravaju posredstvom opioidnih receptora. Dalje, F, C i T ispoljavaju sličnu relativnu jačinu u izazivanju ispitivanih efekata, što ukazuje da su slični receptori uključeni u mehanizam antinocicepcije i neurotoksičnih efekata, i to su najverovatnije μ receptori. Kad se primenjuju ekviantinociceptivne doze, C i T izazivaju značajno kraće i antinociceptivno i neurotoksično dejstvo od F. Nisu dokazane značajne razlike u terapijskim indeksima između F, C i T, što ukazuje da su ovi lekovi jednako bezbedni i podnošljivi kad su u pitanju ispitivani neurotoksični efekti. Ispitivanje neurotoksičnosti prikazano u ovom radu može biti korisno u proučavanju odnosa između strukture i aktivnosti hemijski srodnih opioida