28 research outputs found
Antimikrobno dejstvo eteričnih ulja na oralne patogene
Periodontal disease and Dental caries associated with dental plaque are the most common bacterial diseases, but also, significant oral health problem is Candidiasis. Candida albicans, is an opportunistic pathogen that can, under certain conditions proliferate and cause infections. The need for prevention and alternative forms of treatment and products for oral diseases comes from the rise in disease incidence, increased resistance by pathogenic bacteria to currently used chemotherapeutics. The products derived from medicinal plants have proven to be a source of biologically active substances, and thanks to their active principles, products based on medical herbs are more prevalent in modern phytotherapy. Essential oils are complex natural mixtures of volatile secondary metabolites - aliphatic and aromatic, terpinen and phenyl- propane compounds isolated from plants. The main constituents of essential oils are terpenes and sesquiterpenes including carbohydrates, alcohols, ethers, aldehydes and ketones, which are responsible for the fragrant and biological properties of plants. Different oils produce various pharmacological effects such as anti-inflammatory, antioxidant and anticancerogenic properties, but also oils are biocides. There are numerous in vitro studies that dealt with the research activities of natural herbal substances against oral bacteria that are known to be etiological factors in the development of oral and dental diseases. The phenolic major compounds of essential oils have been suggested to have a potential antifungal activity. There is ample of evidence that plant extracts and essential oils have the potential to be developed into agents that can be used as preventative or treatment therapies of oral diseases.Parodontopatija i dentalni karijes, čiji je nastanak povezan sa dentalnim plakom, predstavljaju najčešća bakterijska oboljenja. Takođe, značajni oralni zdravstveni problem predstavlja i kandidijaza. Candida albicans je oportunistički patogen koji pod pojedinim okolnostima može da proliferiše i uzrokuje infekciju. Potreba za prevencijom i alternativnim oblicima lečenja i produktima za oralna oboljenja proizilazi zbog povećanja učestalosti oboljenja i povećane rezistencije patogenih bakterija na primenu hemoterapeutika koji se trenutno upotrebljavaju. Dokazano je da su produkti dobijeni od lekovitog bilja izvor biološko aktivnih supstanci, a zahvaljujući svojim aktivnim principima, produkti na bazi lekovitog bilja zastupljeniji su u modernoj fitoterapiji. Eterična ulja su kompleksne prirodne mešavine isparljivih sekundarnih metabolita - alifatičnih i aromatičnih, terpenskih i fenil-propanskih jedinjenja izolovanih iz biljaka. Glavni sastojci etarskih ulja su terpeni i seskviterpeni, uključujući i ugljene hidrate, alkohol, etar, aldehide i ketone, koji su odgovorni za mirisna i biološka svojstva biljaka. Različita ulja imaju brojne farmakološke efekte, kao što su antiinflamatorno, antioksidativno i antikancerogeno dejstvo, ali su takođe i biocidi. Postoje brojne in vitro studije koje su se bavile istraživanjem aktivnosti prirodnih biljnih supstanci usmerenih na oralne bakterije za koje je poznato da su etiološki faktori u nastanku oralnih i dentalnih oboljenja. Navedeno je da glavne fenolne komponente eteričnih ulja imaju potencijalnu antigljivičnu aktivnost. Postoje brojni dokazi da biljni ekstrakti i eterična ulja imaju potencijal da se razviju u agense koji se mogu koristiti u preventivi ili u lečenju oralnih oboljenja
Assessment and differentiation of light absorbing carbon in atmospheric aerosols
Light Absorbing Carbon (LAC) or Black carbon (BC) is one of the most important components of fine particulate matter (PM2.5), which is formed through the incomplete combustion of fossil fuels, biofuels and biomass. Based on a number of studies, it has been shown that carbonaceous particles significantly affect air quality/environment and they are an important factor in the carbon cycle and climate change. BC, as one of the constituents of carbonaceous respirable particles, has the property of absorbing light and leads to an increase in the annual average air temperature. Therefore, its quantitative analysis and differentiation for determination of potential radiative effects is extremely important. The BC concentration is usually determined by using thermal or optical methods. In this paper, the results of the application of multiwavelength optical technique for BC estimation which is based on measuring the intensity of absorption/transmission of light through samples of deposited aerosols on PTFE filters, are presented. Sample collection was conducted at Belgrade suburban background site, in heating and nonheating seasons, using low-volume air samplers. In order to estimate the BC concentration of different particle diameters, measurements were performed by using the MABI ANSTO instrument, with LEDs that emit light at seven different wavelengths: 405 nm, 465 nm, 525 nm, 639 nm, 870 nm, 940 nm and 1050nm. The measurement procedure is started by determination of the value of light transmission I0 through an unexposed or blank filter at different wavelengths. After sampling, the estimation of light transmission I through the exposed filters was performed. Before estimation of BC concentration, the light-absorbing coefficient (babs) at each wavelength was determined separately. More intense variations in the values of babs were observed, which most likely occur due to the change in the nature of the pollution sources at the sampling site. The accuracy of the BC concentration depends on the value of the mass absorption coefficient (ε) estimated experimentally and whose values are compared with the predefined manufacturer values. BC generated by combustion at lower temperatures is better absorbed at shorter wavelengths. On the other hand, BC generated through high-temperature processes is better absorbed in the infrared region of the electromagnetic spectrum. Therefore, the differences of BC concentrations at two boundary wavelengths: 405 nm and 1050 nm were analyzed. Finally, seasonal BC variations were observed, with increased values in the winter and autumn periods compared to the summer period.X JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr
Radiology staff dose assessment in primary health centers
Cilj ovog rada je procena efektivnih doza radiološkog osoblja profesionalno izloženih
jonizujućem zračenju u domovima zdravlja u Srbiji. Za procenu doza su primenjene dve
metode: (1) merenje ambijentalnog ekvivalenta doze, H*
(10), korišćenjem jonizacione
komore; i (2) merenje ličnog ekvivalenta doze, Hp(10), korišćenjem termoluminescentnih dozimetara (TLD). Doze su procenjene za radiologe iz devet domova zdravlja koji
rade iz kontrolisane zone zračenja i radiologe iz sedam domova zdravlja koji rade iz
nadgledane zone zračenja. Godišnje doze su date za radiologe i radiološke tehničare za
period od pet uzastopnih godina (2011-2015). Prosečna procenjena godišnja doza ne
prelazi 12 mSv, na osnovu merenja H*
(10), dok je 1,65 mSv maksimalna godišnja doza
izmerena TLD metodom. Dobijeni rezultati pokazuju da doze osoblja ne prelaze
zakonski predviđenu granicu godišnje doze od 20 mSv.The aim of this study is to estimate the effective doses to workers occupationally
exposed to ionizing radiation in small health centers in Serbia. To assess doses two
methods were applied: (1) the measurement of the ambient equivalent dose, H*(10)
using ionization chambers routinely utilized during workplace monitoring; and (2) the
measurement of the personal equivalent dose, Hp(10), using thermoluminescent
dosemeters routinely utilized during individual monitoring. Doses were estimated for
radiologist working from controlled and supervised area. Annual doses are given for
for a period of five consecutive years (2011-2015). The average annual dose does not
exceed 12 mSv assessed by the workplace monitoring method, or 1.65 mSv measured by
the individual monitoring method. The results show that estimated doses are well below
annual dose limits of 20 mSv for the occupational exposure
Radiology staff dose assessment in primary health centers
Cilj ovog rada je procena efektivnih doza radiološkog osoblja profesionalno izloženih
jonizujućem zračenju u domovima zdravlja u Srbiji. Za procenu doza su primenjene dve
metode: (1) merenje ambijentalnog ekvivalenta doze, H*
(10), korišćenjem jonizacione
komore; i (2) merenje ličnog ekvivalenta doze, Hp(10), korišćenjem termoluminescentnih dozimetara (TLD). Doze su procenjene za radiologe iz devet domova zdravlja koji
rade iz kontrolisane zone zračenja i radiologe iz sedam domova zdravlja koji rade iz
nadgledane zone zračenja. Godišnje doze su date za radiologe i radiološke tehničare za
period od pet uzastopnih godina (2011-2015). Prosečna procenjena godišnja doza ne
prelazi 12 mSv, na osnovu merenja H*
(10), dok je 1,65 mSv maksimalna godišnja doza
izmerena TLD metodom. Dobijeni rezultati pokazuju da doze osoblja ne prelaze
zakonski predviđenu granicu godišnje doze od 20 mSv.The aim of this study is to estimate the effective doses to workers occupationally
exposed to ionizing radiation in small health centers in Serbia. To assess doses two
methods were applied: (1) the measurement of the ambient equivalent dose, H*(10)
using ionization chambers routinely utilized during workplace monitoring; and (2) the
measurement of the personal equivalent dose, Hp(10), using thermoluminescent
dosemeters routinely utilized during individual monitoring. Doses were estimated for
radiologist working from controlled and supervised area. Annual doses are given for
for a period of five consecutive years (2011-2015). The average annual dose does not
exceed 12 mSv assessed by the workplace monitoring method, or 1.65 mSv measured by
the individual monitoring method. The results show that estimated doses are well below
annual dose limits of 20 mSv for the occupational exposure
Prisustvo deoksinivalenola u ozimoj pšenici tretiranoj s fungicidima
Natural occurrence of Fusarium spp. and concentrations of mycotoxin deoxynivalenol (DON) in the grain of the winter wheat moderately susceptible to Fusarium head blight (FHB) has been studied. Grain samples were collected from wheat crops intended mainly for human consumption. All wheat crops were treated with fungicides before (a.i. flutriafol - formulated as Fluoco, applied in dose of 0.5 l ha-1) and during the flowering phase of growing (a.i. thiophanate-methyl + epoxiconazole formulated as Eskorta plus and a.i. thiophanate-methyl formulated as Funomil, applied in doses of 0.75 and 0.5 l ha-1, respectivily). Among of Fusarium species only F. graminearum, as a well known producer of DON, was identified. This fungus was identified in 15 of 19 samples (78.9%) with incidence in positive samples of 2 to 28% (average, 14.0%). Presence of DON was established in 13 of a total 19 investigated wheat grain samples (68.4%). In positive samples DON was detected in concentrations from 69 to 918 μg kg-1 (average, 478 μg kg-1). DON showed a significant and positive correlation at P≥0.05 with grain moisture content (r = 0.52*). Between the frequency of F. graminearum and concentration of DON and between the frequency of F. graminearum and grain moisture content, positive correlation was determined, but without statistical significance (r = 0.44 and r = 0.29, respectively).U radu je proučavana prirodna pojava Fusarium spp. i koncentracija mikotoksina deoksinivalenola (DON) u zrnu ozime pšenice srednje osetljive prema fuzariozi klasa (FHB). Uzorci zrna su prikupljeni sa proizvodnih useva pšenice namenjene uglavnom za ljudsku upotrebu. Svi usevi pšenice bili su tretirani sa fungicidima pre (a.m. flutriafol - formulisana kao preparat Fluoco, primenjen u dozi 0,5 l ha-1) i tokom cvetanja biljaka (a.m. tiofanat-metil + epoksikonazol formulisana kao preparat Eskorta plus i a.m. tiofanat-metil formulisana kao Funomil, primenjeni u dozi 0.75 i 0.5 l ha-1, respektivno). Među Fusarium vrstama jedino je identifikovana F. graminearum, koja je poznati producent DON. Ova gljiva je bila identifikovana u 15 od 19 uzoraka (78.9%) sa incidencom od 2 do 28% (prosek 14.0%) u pozitivnim uzorcima. Prisustvo DON je utvrđeno u 13 od ukupno 19 proučavanih uzoraka pšenice (68.4%). U pozitivnim uzorcima DON je detektovan u koncentracijama od 69 do 918 μg kg-1 (prosek 478 μg kg-1). DON je pokazao značajnu i pozitivnu korelaciju pri P≥0.05 sa sadržajem vlage zrna (r = 0.52*). Između učestalosti F. graminearum i koncentracije DON i učestalosti F. graminearum i sadržaja vlage zrna utvrđena je, takođe, pozitivna korelacija ali statistički nije značajna (r = 0.44 i r = 0.29, respektivno)
The measurement of ambient dose equivalent by passive dosimeters method during CBRN exercise
Za potrebe obuke lica za delovanje u slučaju hemijskih, bioloških, radioloških i
nuklearnih akcidenata (HBRN) uspostavljena je platforma u okviru Instituta za
nuklearne nauke Vinča (INNV). Na samoj platformi se između ostalih izvode praktična
uvežbavanja: lociranja radioaktivnog izvora, obezbeđivanja izvora i različitih scenarija
dekontaminacije. Jedna od nadležnosti Laboratorije za zaštitu od zračenja i zaštitu
životne sredine (Zaštita) je da primeni odgvarajuće mere radi kontrolisanog izlaganja
jonizujućem zračenju pojedinaca na platformi kao i radnika INNV. U ovom radu su
prikazani rezultati merenja ambijentalnog ekvivalenta doze, H*(10) pomoću termoluminiscentnih dozimetara (TLD) koji su postavljeni u cilju monitoringa okoline tokom
HBRN vežbe koja je izvedena u aprilu 2017. Merenja su vršena postavljanjem TLD na
22 lokacije na samoj platformi i van nje u trajanju od 14 dana. Izmerena srednja
vrednost H*(10) iznosi 34 µSv za posmatrani period što pokazuje da nije došlo do
značajnog povećanja ambijentalne ekvivalentne doze u odnosu na osnovni nivo
prirodnog zračenja.For the purpose of professional responder training in the case of chemical, biological,
radiological and nuclear accidents (CBRN), a training platform was established within
the Vinca Institute of Nuclear Sciences (INNV). On the platform, among other things,
practical exercises are carried out such as: locating radioactive sources, securing
sources and various decontamination scenarios. One of the responsibilities of the
Department of Radiation and Environmental Protection (Zastita) is to apply specific
measures for the controlled exposure to ionizing radiation of individuals on the
platform as well as of INNV workers. This paper presents the ambient dose equivalent
H*(10), measured using thermoluminescent dosimeters (TLDs) that were set up to
monitor the environment during the CBRN exercise in April 2017. The measurements
were made by placing the TLD at 22 locations on the platform itself, and out of it for 14
days. The mean H*(10) is 33 µSv for the observed period, which shows that there was
no significant increase in the ambient dose relative to the background level.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин
Review of the thermoluminescent dosimetry method for the environmental dose monitoring
Passive solid state dosimeters, such as thermoluminescence dosimeters, provide integrated measurement of the total dose and are widely used in environmental monitoring programs. The objective of this paper is to provide a comprehensive review on the use of thermoluminescent dosimetry methods for monitoring radiation dose in the environment. The article presents the part of the research results of the project PREPAREDNESS (EMPIR 2016 call for Metrology for Environment joint research project) with a particular objective to harmonize procedures used by dosimetry services, relevant authorities and Institutes across the Europe. To achieve this, different monitoring routines that are based on passive environ mental dosimetry methods are investigated. Differences in performing specific steps such as preheating, reading, annealing, minimizing fading, and others, are analyzed. The investigation was performed by means of qualitative literature review that showed the lack of information about specific steps. The conclusion of this work is that thermoluminescent dosimetry measurement system has to be type-tested even though the testing procedure is complicated. In addition to this, control dosimeters should be introduced, International Organization for Standardization protocols should be followed during calibration, and finally, parameters influencing the measurement uncertainty have to be identified and well understood in order to pro duce ac cu rate dose measurement results
Utilizing Monte Carlo simulations in estimation of occupational eye lens dose based on whole body dosemeter in interventional cardiology and radiology
Medical staff performing interventional procedures in cardiology and radiology is considered to be a professional group exposed to high doses of ionizing radiation. With new epidemiological evidences and recently reduced eye lens dose limit, dose assessment to the lens of the eye, in the interventional cardiology, has become one of the most challenging research topics. This paper presents results of the eye lens dose assessment in interventional cardiology obtained by means of the computational dosimetry. Since placing and wearing the dedicated eye lens dosimeter is encumbering for the staff, Monte Carlo simulation provides an accurate and efficient method for obtaining an indication of doses to the eye lenses. Eye lens doses were estimated for three typical beam projections (PA, LAO, and RAO) and tube voltages ranging from 80 kV to 110 kV, with different protective equipment setups, for the first operator position. Simulations were carried out using MCNPX code. Results revealed that a whole body dosimeter worn at the thyroid center position gives the best estimate of the eye lens dose with a spread from 11 % to 18 % for the left eye. Corresponding average conversion coefficient from whole body lo the eye lens dose is estimated to be 0.18. © 2018; Vinca Inst Nuclear Sci. All rights reserved
Results of IMS participation in international intercomparisons for whole body dosemeters – 10 years of study
The regular participation of an accredited individual monitoring service (IMS) in the international and/or interlaboratory intercomparisons (IC) is required according to ISO/IEC 17025:2017 standard, General requirements for the competence of testing and calibration laboratories. By taking the part in an IC, IMS shows competence, reliability, and has an opportunity to learn further and improve its measurement method. The European Dosimetry Group (EURADOS) Working Group 2 (WG2) has acknowledged the value of the regular IC and also found that data and results from it are fundamental for the harmonization of the measurement process [1]. Thus, EURADOS started a self-sustained program of IC for IMS for external radiation on a biannual basis. The results of an accredited IMS at the Department of Radiation and Environmental Protection, “VINČA” Institute of Nuclear Sciences, Belgrade, Serbia (IMS VINS) in the EURADOS IC for the period 2010-2020 (excluding 2014) are presented. IMS VINS use thermoluminescent whole body dosemeters based on two TLD-100TM (Thermo Scientific™ Harshaw™, USA) detectors. The readouts are done on the Harshaw TLD™ Model 6600 Plus Automated Reader (Thermo Fisher Scientific, USA). The whole glow curve is used for dose estimation (all of 200 channels). The calibration of the dosimetric system is done twice a year in S-Cs (previously in S-Co) field at the secondary standard dosimetry laboratory (SSDL VINS), according to ISO 4037-3:2019. The IC had 40 different reference values of personal dose equivalent, Hp(10) in noted period ranging from 0.431 mSv to 501 mSv. There were 20, 16, 22, 22, 20 dosemeters irradiated in year 2010, 2012, 2016, 2018, 2020, respectively. The radiations were done in 12 different fields: N-60, S-Co, S-Cs, N-40, N-150, S-Cs+Sr90, S-Cs+N-40, W-110, S-Cs+W-250, W-60, S-Cs+W-80, and S-Cs+N-150. The relative response (R) range is from 0.23 to 2.26. Quantile values for R are: 0.23, 0.79, 0.90, 1.1, and 2.26, respectively for (0%, 25 %, 50 %, 75 % and 100 % of points). Mean and standard deviation of R are 0.97 and 0.30, respectively. The performance limits are established according to ISO 14146 trumpet-curve [1]. Due to trumpet-curve there were 6 outliers (2 in 2010, 4 in 2016). All of the outliers were for reference dose around 1 mSv and lower. One outlier from 2010 was irradiated in N-40 field and 30° of incident angle. The other outlier was irradiated in the S-Cs field, without any rotation, and thus should have had a satisfying response. The possible explanation is an insensitive TL detector. The outliers in 2016 were all for N-40 quality and ±60° angle. Thus, considering the low number of outliers (only one true outlier) and expected dosemeters faulty response for given irradiation parameters, we conclude that the IMS VINS dosimetry system had satisfactory behavior during IC from 2010-2020.X JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr
TLD-100 post-irradiation fading characteristics according to IEC 62387:2020 standard
The results of the post-irradiation fading of whole body dosemeters based on two TLD-100TM (Thermo Scientific™ Harshaw™, USA) detectors are presented. The dosemeters are regularly used by accredited individual monitoring service (IMS) at Vinca Institute of Nuclear Science (VINS), Belgrade, Serbia. The testing of post-irradiation fading was carried out according to International Electrotechnical Commission (IEC) 62387:2020 standard. The irradiations are done in S-Cs137 field at secondary standard dosimetry laboratory (SSDL) at VINS, according to International Organization for Standardization document ISO 4037-3:2019. The chosen reference personal dose equivalent value was 3 mSv. The research was carried out in the period from October 2020 to February 2021, and it lasted 128 days. The frequency of irradiations was approximately 7 days, while 3 periods between irradiations were longer than 10 days, due to COVID-19 pandemic. The irradiations were performed at different dates; thus, all dose readouts were done on the same day to prevent influence of reader’s instabilities. The irradiated dosemeters were stored at the same room where the average temperature was nearly 20°C. There were 14 groups with 6 dosemeters for irradiation and 2 dosemeters for natural background radiation level correction. The reader was Harshaw TLD™ Model 6600 Plus Automated Reader (Thermo Fisher Scientific, USA). The whole glow curve was used for dose estimation (all of 200 channels). The time as influence quantity was considered to be of type F, thus the range of relative response was limiting factor in the analysis. The results showed that the maximum measurement time tmax is 72 days for deep dose (Hp(10)) detector, and 85 days for shallow dose (Hp(0.07)) detector. Thus, the standard’s requirement is satisfied, as it is required minimum of 30 days. The relative response range for all of the 14 groups was from 0.82 to 1.14 and from 0.83 to 1.17, for deep and shallow dose, respectively. The research has limitation as the irradiations were organized aligned to COVID-19 working schedule. One of the consequences of this timetable is lack of 7 days’ time point, thus the values from 16 days’ time point was used as referential.IX International Conference on Radiation in Various Fields of Research : RAD 2021 : book of abstracts; June 14-18, 2021; Herceg Novi, Montenegr