Nivo policikličnih aromatičnih ugljovodonika u gasnoj i čestičnoj fazi u školama na različitim lokacijama u Srbiji

This study investigated seasonal variation of PAHs and their partition between gas and particulate-bounded phases in indoor and outdoor air in 4 schools In Serbia located at different locations. The sampling campaigns were conducted during one workweek at each school successively. Campaigns were conducted in schools during heating and non-heating seasons in December 2011 and June 2012. Seasonal variations of gas and particle-bounded PAHs concentrations were observed with higher levels during heating season. The highest total PAH values were associated with the gas phase in both sampling periods. The total PAHs concentration at indoor and at the outdoor sites, during heating season, ranged from 88.45 to 447.72 ng/m(3) and 201.69 to 1017.15 ng/m(3), respectively. During non-heating season, the total PAHs concentration ranged from 36.91 to 271.57 ng/m(3) in Indoor environment and 27.00 to 132.32 ng/m(3) in outdoor environment. Most of the I/O ratios were less than 1, which indicated that the indoor PAHs were mostly from outdoor sources. The use of diagnostic ratio showed that traffic emission and coal combustion are the major sources of PAHs. Only the diagnostic ratios for the school located near the industrial area showed significant deviation compared to other schools.U ovom radu su istraživane sezonske promene PAH i njihova raspodela, u gasnoj fazi i respirabilnim česticama u vazduhu unutrašnjeg prostora i spoljašnje sredine u 4 škole u Srbiji koje se nalaze na različitim lokacijama. Kampanja uzorkovanja je sprovedena tokom jedne radne nedelje u toku grejnog i negrejnog perioda (od decembra 2011. do juna 2012.) u svakoj školi. Uočene su sezonske promene nivoa PAH u gasnoj fazi i česticama, sa višim koncentracijama tokom grejnog perioda. Izmerena je veća vrednost zbira ukupnih PAH tokom oba perioda u gasnoj fazi nego PAH u česticama. Ukupna koncentracija PAH tokom grejnog perioda u unutrašnjem prostoru se kretala u opsegu od 88,45 do 447,72 ng/m3, a u spoljašnjoj sredini od 201,69 do 1017,15 ng/m3. Tokom negrejnog perioda, ukupna koncentracija PAH-ova je bila 36,91-271,57 ng/m3 u unutrašnjem prostoru, dok je u spoljašnjoj sredini bila 27,00-132,32 ng/m3. Većina I/O odnosa je bila manja od 1, što ukazuje da PAH u unutrašnjem prostoru uglavnom potiču iz spoljašnjeg vazduha. Na osnovu dijagnostičkih odnosa zaključeno je da su saobraćaj i sagorevanje uglja glavni izvori PAH. Jedino dijagnostički odnosi za školu koja se nalazi u blizini industrijske zone pokazuju značajno odstupanje u poređenju sa drugim školama

Synthesis, structure and thermogravimetric analysis of alpha,omega-telechelic polydimethylsiloxanes of low molecular weight

A series of alpha,omega-telechelic polydimethylsiloxanes (PDMS), with predetermined molecular weights of about 2500 g mol(-1), was synthesized by siloxane equilibration reaction. Syntheses were performed using octamethylcyclotetrasiloxane (D-4) and various disiloxanes: hexamethyldisiloxane (HMDS), 1,1,3,3-tetramethyldisiloxane (TMDS), 1,3-divinyltetramethyldisiloxane (DVTMDS), 1,3-bis(3-carboxypropyl) tetramethyldisiloxane (DCPTMDS) and 1,3-bis(3-aminopropyl) tetramethyldisiloxane (DAPTMDS). The role of the disiloxane was to introduce terminal functional groups at the end of the polymer chains and to control the molecular weight of the polymers. Polymers with trimethyl, hydrido, vinyl, carboxypropyl and aminopropyl end-groups were obtained in this way. The structure of the alpha,omega-telechelic PDMSs was confirmed by NMR and IR spectroscopy. The molecular weights of the polymers were determined by H-1-NMR, gel permeation chromatography (GPC) and dilute solution viscometry. Thermogravimetric analysis (TGA) under nitrogen and air showed that the type of the terminal groups significantly influenced the thermal and thermo-oxidative stability, as well as the degradation mechanism of the alpha,omega-telechelic PDMSs

Koncentracija suspendovanih čestica (PM10 I PM2.5) i njihov odnos unutra/spolja u odabranim obrazovnim ustanovama u Nišu

Mass concentrations of particulate matter (PM) fractions were measured in educational buildings in the city of Nis, Serbia. Two sampling campaigns were conducted in winter periods. The first campaign was in the period from 21 February to 15 April 2010 at the Faculty of Occupational Safety (FOS) and the second campaign was from 20 March to 4 April 2013 at the primary school Void Karadorde (VK). PM measurements were carried out with low volume samplers Sven/Leckel LVS3. The average daily PM10 concentration inside the FOS (47.0 +/- 21.8 mu g/m(3)) was lower than PM10 concentration in outdoor air (50.7 +/- 28.1 mu g/m(3)). The average daily PM10 concentration inside the VK (54.6 +/- 17.6 mu g/m(3)) was higher than in outdoor air (47.9 +/- 22.8 mu g/m(3)). The 24-hours, average PM10 concentrations at FOS exceeded the EU limit value (50 mu g/m(3)) during 34% of days outdoors and 39% of days indoors. The 24-hours average PM10 concentrations at VK exceeded the limit value during 35% of days outdoors and 53% of days indoors. The 24-hours average PM2.5 concentrations at VK exceeded the WHO daily mean guideline value (25 mu g/m(3)) during 71% of days outdoors and 88% of days indoors. The average PM10 I/O ratio at VK was 1.57 during teaching hours, and 1.00 during no teaching hours. Similarly, average PM2.5 I/O ratio at VK was 1.11 during teaching hours and 0.90 during no teaching hours. Average daily PM2.5/PM10 ratio in the ambient air at VK was 0.87 and 0.82 at FOS. Very strong correlations between the indoor and outdoor PM concentrations were observed at VK during no teaching hours (r gt 0.8). Moderate to strong negative correlations were found between the wind speed and PM at both schools. High outdoor PM concentrations and resuspension of particles are possible reasons for the elevated indoor PM concentrations found in the study.U radu su prikazani rezultati merenja suspendovanih čestica frakcija PM10 i PM2.5 u dve izabrane obrazovne ustanove u Nišu. Kampanje merenja sprovedene su u zimskom periodu. Prva u periodu od 21.02. do 15.04.2010. na Fakultetu zaštite na radu (FOS), a druga u periodu od 20.03. do 04.04.2013. u osnovnoj školi Vožd Karađorđe (VK). Uzorkovanje suspendovanih čestica vršeno je uzorkivačima Sven/Leckel LVS3, simultano, unutar i izvan odabranih ustanova. Prosečna dnevna koncentracija čestica PM10 unutar objekta FOS (47,0±21,8 μg/m3) bila je niža u odnosu na prosečnu dnevnu koncentraciju PM10 u ambijentalnom vazduhu (50,7±28,1 μg/m3). Prosečna dnevna koncentracija čestica PM10 unutar objekta VK (54.6±17.6 μg/m3) bila je viša u odnosu na prosečnu dnevnu koncentraciju PM10 u ambijentalnom vazduhu (47.9±22.8 μg/m3). Srednje dnevne koncentracije čestica PM10 izmerene na lokaciji FOS u ambijentalnom vazduhu prelazile su dnevnu graničnu vrednost (50 ìg/m3) tokom 34% dana trajanja kampanje merenja. Srednje dnevne koncentracije čestica PM10 izmerene unutar objekta FOS prelazile su dnevnu graničnu vrednost tokom 39% dana trajanja kampanje merenja. Srednje dnevne koncentracije čestica PM10 izmerene na lokaciji VK u ambijentalnom vazduhu prelazile su dnevnu graničnu vrednost tokom 35% dana trajanja kampanje merenja, odnosno tokom 53% dana trajanja kampanje u unutrašnjosti objekta VK. Srednje dnevne koncentracije čestica PM2,5 izmerene na lokaciji VK u ambijentalnom vazduhu prelazile su dnevnu graničnu vrednost (25 ìg/m3) tokom 71% dana trajanja kampanje, odnosno tokom 88% dana u unutrašnjosti objekta VK. Prosečan dnevni odnos unutra/spolja čestica frakcije PM10 na lokaciji VK iznosio je 1,57 u vreme nastave, odnosno 1,00 kada nije bilo nastave. Prosečan dnevni odnos unutra/spolja čestica frakcije PM2,5 na lokaciji VK iznosio je 1.11 u vreme nastave, odnosno 0.90 kada nije bilo nastave. Prosečan dnevni odnos PM2,5/PM10 u ambijentalnom vazduhu na lokaciji VK bio je 0,87, odnosno 0,82 na lokaciji FOS. Detektovana je veoma jaka korelacija između koncentracija suspendovanih čestica unutar i izvan objekta VK u periodu kada nije bilo nastave (r gt 0.8). Umerena do jaka korelacija detektovana je između brzine vetra i koncentracija suspendovanih čestica na obe lokacije (FOS i VK). Visoke koncentracije suspendovanih čestica u ambijentalnom vazduhu i resuspenzija čestica najverovatniji su razlog koji utiče na povećane koncentracije suspendovanih čestica u unutrašnjem prostoru posmatranih obrazovnih ustanova

Accumulation of 17 organochlorine pesticides in muscle of pikeperch (Sander lucioperca) from Garaši reservoir (Serbia)

Samples of pikeperch (20 in total) were caught at Garaši reservoir during the summer of 2017. The objectives of this research was to analyse the concentrations of 17 organochlorine pesticides (aldrin, α-HCH, β-HCH, γ-HCH, δ-HCH, 4,4’-DDD, 4,4’-DDE, 4,4’-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide, and metoxychlor) in fish muscle by gas chromatography with mass spectrometric (GC-MS) detection. QuEChERS method was used for extraction and clean-up of pesticide residues from muscle tissue. Three phenyl phosphate (TPP) was used as an internal standard. Concentrations of 4,4’-DDD, 4,4’-DDE, 4,4’-DDT, heptachlor and heptachlor epoxide in fish muscle were compared with the maximum allowed concentrations (MAC) in fish meat set by the national legislation of Serbia. This reservoir is used as a drinking water source. Therefore, the hypothesis was that it was exposed to low organic pollution. The concentrations of all analyzed pesticides were below the detection limits. In conclusion, there is no health risk for consumption of pikeperch from Garaši reservoir

Hemijski sastav M. Semimembranosus i M. Longissimus Thoracis et Lumborum svinja pet čistih rasa odgajanih u Vojvodini

U ovom radu utvrđen je sadržaj vlage, proteina, ukupne masti i ukupnog pepela u M. semimembranosus (SM) i M. longissimus thoracis et lumborum (LTL) pet čistih rasa svinja: Velika Bela (n=118), Landras (n=116), Durok (n=112), Hempšir (n=112) i Pietren (n=121), odgajanih u Vojvodini. Osnovni hemijski sastav određen je ISO metodama. Ukupno, prosečan sadržaj (g/100g) vlage, proteina, ukupne masti i ukupnog pepela u svim ispitanim mišićima SM i LTL (n=1158) je bio: 75.68, 21.73, 1.36 i 1.14, respektivno. Svinjsko meso proizvedeno u Vojvodini pokazuje sličan sadržaj vlage, proteina, masti i pepela u poređenju sa sadržajima utvrđenim u drugim zemljama

Hemijski sastav jetri i bubrega svinja pet čistih rasa odgajanih u Vojvodini

In this paper the content of moisture, protein, total fat and total ash in the M. semimembranosus (SM) and M. longissimus thoracis et lumborum (LTL) from five purebred pigs: Large White (n=118), Landrace (n=116), Duroc (n=112), Hampshire (n=112) and Pietrain (n=121), reared in Vojvodina was determined. Components of proximate composition were determined by ISO methods. Overall, the average content (g/100g) of moisture, protein, total fat and total ash in all the SM and LTL (n=1158) was: 75.68, 21.73, 1.36 and 1.14, respectively. The Vojvodian pork showed same moisture, protein, total fat and total ash content compared with the values found in other countries.U ovom radu utvrđen je sadržaj vlage, proteina, ukupne masti i ukupnog pepela u jetrama i bubrezima svinja pet čistih rasa: Velika Bela (n=118), Landras (n=116), Durok (n=112), Hempšir (n=112) i Pietren (n=121), odgajanih u Vojvodini. Osnovni hemijski sastav određen je ISO metodama. Rasa svinja ne utiče značajno (P>0.05), dok vrsta iznutrice utiče značajno (P<0.05; P<0.001) na sadržaj vlage, proteina, ukupne masti i ukupnog pepela. Prosečan sadržaj (g/100g) vlage, proteina, ukupne masti i ukupnog pepela u svim ispitanim jetrama (n=579) je bio: 71.05, 21.34, 3.24 i 1.48, dok je u svim ispitanim bubrezima (n=579) bio: 79.43, 16.16, 3.13 i 1.20, respektivno

Efficacy And Safety Of IVUS-Guided Percutaneous Coronary Interventions

The inclusion of IVUS-guided PCI has yet to become a routine approach in invasive cardiology due to the relatively high cost of the procedure, equivocal positive results in important studies and the steep learning curve. As an additional diagnostic tool, IVUS seems to be irreplaceable in stent apposition research, edge dissections and the determination of plaque composition

INFLUENCE OF THE MENOPAUSAL STATUS TO THE FREQUENCY AND PATHOHISTOLOGICAL FEATURES OF ENDOMETRIAL HYPERPLASIA AND CARCINOMA IN PATIENTS WITH ABNORMAL UTERINE BLEEDING

The aim of the study was to determine the frequency and pathohistological features of endometrial hyperplasia and carcinoma in premenopausal and postmenopausal patients with abnormal uterine bleeding (AUB).The frequency and pathohistological features of endometrial hyperplasia and carcinoma were investigated in 961 patients with AUB who underwent dilatation and curettage (D&C) between January and December 2006. Regarding the menopausal status, patients were divided into two groups: group of premenopausal patients (n=808) and group of postmenopausal patients (n=153).Endometrial hyperplasia was significantly (p<0,05) more frequent cause of AUB in premenopausal patients (23,4%) than in postmenopausal patients (13,7%). AUB caused by endometrial carcinoma was significantly (p<0,001) more common in postmenopausal patients (18,9%) than in premenopausal patients (1,4%). Compared to the postmenopausal patients, endometrial hyperplasia without atypia was significantly (p<0,01) more frequent, while atypical hyperplasia was significantly (p<0,05) less frequent in premenopausal patients. In contrast to the premenopausal patients, endometrioid type and non-endometrioid type of endometrial carcinoma and carcinoma localized in endometrial polyp were significantly more common in postmenopausal patients (p<0,001, p<0,001, p<0,05, respectively).Endometrial hyperplasia (diffuse or localized to the polyp) is more frequent cause of AUB in premenopausal patients than in postmenopausal patents. Compared to the premenopausal patients, atypical hyperplasia and endometrial carcinoma are more frequent causes of AUB in postmenopausal patients. In contrast to the premenopause, there were higher risks for developing endometrioid type and non-endometrioid type of endometrial carcinoma and carcinoma localized in endometrial polyp in postmenopause

A kinetic study of quicklime-catalyzed sunflower oil methanolysis

The quicklime-catalyzed sunflower oil methanolysis was studied at mild reaction conditions. Quicklime (calcined at 550 degrees C for 4h) in amounts of 1.0, 2.5, 5.0 and 10.0% (based on the oil weight) and different molar ratios of methanol-to-oil (6:1, 12:1 and 18:1) were employed to investigate their influence on the methyl esters content and the kinetics of the methanolysis reaction. The optimal methanol-to-oil molar ratio and quicklime amount for achieving the highest fatty acid methyl esters content were established to be 12:1 and 5% (based on the oil weight), respectively. The sigmoidal kinetics of quicklime-catalyzed methanolysis reaction was described by a model which included the changing mechanism of the reaction and the triacylglycerols mass transfer limitation. The kinetic parameters were determined and correlated with the process variables. A good agreement between the kinetic model and the experimental data for all applied reaction conditions was observed