Primena 'šetajuće' tehnike beljenja u izbeljivanju endodontski lečenih zuba - prikaz slučaja

Introduction. Discolored teeth in the anterior region can cause considerable cosmetic impairment. One of the techniques commonly used for bleaching endodontically treated teeth is 'walking' bleach technique, which in many cases provides satisfying results. The aim of this study was to evaluate bleaching efficacy of 'walking' bleach technique in an endodontically treated tooth. Case Report. A 22-year-old patient showed up to the clinic because of discoloration of the maxillary right central incisor. The mixture of sodium perborate and 30% hydrogen peroxide was applied and changed weekly. The total duration of therapy was 28 days. At the end of therapy, the tooth achieved 3 shades lighter color. Conclusion. The mixture of sodium perborate and 30% hydrogen peroxide can successfully bleach discolored endodontically treated teeth.Uvod. Izbeljivanje depulpisanih zuba jeste tretman pojedinačnih diskoloracija čiji je cilj vraćanje estetske harmonije zubika. Jedna od često korišćenih tehnika izbeljivanja prebojenih endodontski lečenih zuba je i 'šetajuća' tehnika beljenja, koja je u mnogim slučajevima bila veoma uspešna. Cilj rada bio je da se prikažu mogućnosti i postupak izbeljivanja endodontski lečenog zuba primenom ove tehnike beljenja. Prikaz slučaja. Dvadesetdvogodišnja pacijentkinja se javila na kliniku zbog diskoloracije maksilarnog desnog centralnog sekutića. Izbeljivanje je urađeno primenom intrakoronalne postavke smese natrijum-perborata i tridesetoprocentnog vodonik- peroksida. Sveže zamešena smesa materijala za beljenje nanošena je svakih sedam dana. Terapija je ukupno trajala 28 dana. Rezultat terapije izbeljivanja depulpisanog zuba bio je za tri nijanse svetliji zub u odnosu na boju zuba pre početka tretmana. Zaključak. Smesa natrijum- perborata i tridesetoprocentnog vodonik- peroksida veoma uspešno izbeljuje depulpisane zube, prebojene kao posledica endodontskog silera

C18-UHPLC analysis of retention behavior of newly designed o-alkylated and rostane derivatives in ternary mixture methanol/acetonitrile/water

Different new groups of steroid compounds are the center of attention in a grate number of scientific publications since the majority of compounds are being researched as anticancer drugs. One of the most important feature of potential drug is its lipophilicity. Nowadays, ultra high-performance liquid chromatography (UHPLC) is used as one of the most sophisticated techniques for determination of the retention behavior determination of different biologically active compounds. The series of 18 newly designed O-alkylated androstane derivatives was investigated in reversed phase (RP)-UHPLC system using ternary mixture methanol/acetonitrile/water. A good agreement between experimentally observed and in silico lipophilicity was noticed given that coefficient of determination of 0.8406 was achieved

Contribution to the knowledge of the allochthonous flora in the lower course of the Sava river

Floristička istraživanja alohtone flore u donjem toku reke Save sprovedena su na lokalitetima Sremska Mitrovica, Jarak (opština Sremska Mitrovica), Šabac, „Crni lug“ (Boljevci, Surčin) i na području od Ostružnice do Makiša (uključujući i Makiš). Ovim istraživanjima je obuhvaćeno samo vodno telo, poplavna zona, nasip, kanali, napuštene i obradive površine koje su u neposrednoj blizini rečnog toka ili poplavne zone. Detektovano je 48 alohtonih biljaka, svrstanih u 24 familije, među kojima se po broju vrsta ističu Asteraceae (29,2%), Poaceae (10,4%) i Fabaceae (8,3%). Biološki spektar alohtone flore je terofitskog tipa, dok u hronološkom spektru dominiraju neofite, a u horološkom spektru vrste severnoameričkog porekla. Najčešći načini disperzije alohtonih vrsta su antropohorija, zoohorija i anemohorija. U reci Savi su zabeležene tri alohtone makrofite (Elodea canadensis, Vallisneria spiralis i Paspalum paspaloides), dok su na drugim površinama najfrekventnije i najbrojnije Acer negundo, Morus alba, Fraxinus lanceolata, Amorpha fruticosa, Ambrosia artemisiifolia, Stenactis anuua, Amaranthus retroflexus i vrste rodova Solidago i Xantium. Da bi se sprečila degradacija prirodnih i antropogeno uslovljenih ekosistema u donjem toku reke Save, koji pogoduju naseljavanju, odomaćivanju i daljem rasejavanju alohtonih biljaka, treba preduzeti odgovarajuće preventivne mere. Najefikasnija strategija u borbi protiv invazivnih vrsta je upravo sprečavanje njihove invazije.Floristic research of alien flora in lower course of the Sava River basin was conducted on the localities Sremska Mitrovica, Jarak (municipality of Sremska Mitrovica), Šabac, "Crni Lug" (Boljevci, Surčin) and area between Ostružnica and Makiš (including Makiš). Research included water body, flood zones, mounds, canals, abandoned and arable land close to the riverbed or flood zone. It was detected 48 alien plants, grouped into 24 families, among which Asteraceae (29.2%), Poaceae (10.4%) and Fabaceae (8.3%) stands out by number of alien species. The biological spectrum is therophyte type, chronological spectrum is dominated by neophytes and chorological spectrum is dominated by species of North American origin. The most common dispersal methods are dispersal by humans, animals and wind. In the Sava River riverbed three alien macrophytes were recorded (Elodea canadensis, Vallisneria spiralis and Paspalum paspaloides), while in other areas the most frequent species were Acer negundo, Morus alba, Fraxinus lanceolata, Amorpha fruticosa, Ambrosia artemisiifolia, Stenactis anua, Amaranthus retroflexus, and species of genera Xanthium and Solidago. In order to prevent degradation of the natural and anthropogenically altered ecosystems in the lower course of the Sava river, caused by the introduction of alien species, their naturalisation and dissemination, it should take appropriate preventive measures. The most effective strategy in fighting against invasive species is to prevent their invasion

Chemometric approach to quality characterization of milk-based kombucha beverages

Mliječni kombuča napici su dobiveni fermentacijom mlijeka kombučom. Hijerarhijska klaster analiza (HCA) i analiza glavnih komponenti (PCA) primijenjene su u cilju utvrđivanja razlika između analiziranih uzoraka, kao i identifikacije sličnosti ili različitosti između njih, u prostoru eksperimentalno određenih vrijednosti varijabli. Linearna diskriminantna analiza (LDA) provedena je na neobrađenim podacima u cilju pronalaženja pravila za dodjeljivanje novog uzorka nepoznatog porijekla odgovarajućoj grupi uzoraka. Hijerarhijska klaster analiza pokazala je da je dominantan faktor razlikovanja analiziranih uzoraka kombuča napitaka sadržaj mliječne masti, a zatim slijede sadržaji ukupnih nezasićenih, jednostruko nezasićenih (MUFA) i višestruko nezasićenih (PUFA) masnih kiselina. Uzorci s 0,8 i 1,6 % mliječne masti pripadaju istom klasteru u prostoru analiziranih varijabli zbog sličnosti u njihovoj antioksidativnoj aktivnosti prema DPPH radikalu. Linearnom diskriminantnom analizom utvrđeno je da je najveća razlika u kvaliteti kada se u obzir uzmu vrijednosti pH i antioksidativna aktivnost prema DPPH radikalu između grupa proizvoda sa čajem primorskog vriska i koprivom, dok je najveća sličnost između grupa proizvoda s majčinom dušicom i paprenom metvicom.Milk-based kombucha beverages were obtained conducting kombucha lead fermentation of milk. In order to discriminate the analysed samples and to detect similarities or dissimilarities among them in the space of experimentally determined variables, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied. Linear discriminant analysis (LDA) was conducted on the raw data set in order to find a rule for allocating a new sample of unknown origin to the correct group of samples. In the space of the variables analysed by HCA, the dominant discriminating factor for the studied samples of kombucha beverages is the milk fat (MF) content, followed by total unsaturated fatty acids content (TUFA), monounsaturated fatty acids content (MUFA) and polyunsaturated fatty acids content (PUFA). The samples with 0.8 and 1.6% milk fat belong to the same cluster in the space of the analysed variables due to similarities in their AADPPH. It was determined by LDA that there was the biggest difference in quality between the groups of products with winter savoury and stinging nettle, while the highest similarity is between groups of products with wild thyme and peppermint regarding their pH values and antioxidant activity expressed as AADPPH

Possibilities of assessing trace metal pollution using Betula pendula Roth. leaf and bark - experience in Serbia

In this study, both seasonal and spatial variations in trace metal uptake, as well as concentration of photosynthetic pigments in Silver birch (Betula pendula Roth.) trees in five urban parks in Pančevo, Smederevo, Obrenovac and Belgrade (Serbia) affected by different anthropogenic activities were studied. The characteristics of soil were assessed in terms of texture, pH and trace element content. Concentrations of boron, strontium and zinc in both leaves and bark showed an increasing temporal trend, however, copper showed an opposite seasonal trend. A higher accumulation of trace elements was noticed in leaves compared to bark. The obtained results for photosynthetic pigments showed low sensitivity of birch to B, Cu, Sr and Zn contamination, indicating that birch tolerates pollution and climate stress by increasing the amount of pigments. Analysis of the effects on soil chemistry of trace element accumulation in plant tissues proved that soil chemistry poorly explains the variability of elements in bark (27.6 %) compared to leaves (82.99 %). Discriminant analysis showed that Belgrade and Smederevo are clearly separated from the other three sites.Journal of the Serbian Chemical Society (2017), 82(6): 723-73