Monitoring the eutrophication using Landsat 8 in the Boka Kotorska Bay

Ova studija predlaže metodologiju za nadgledanje koncentracija klorofila-a i eutrofičnog stanja u malim zalivima ili u blizini obale. Ova vrsta nadgledanja je zanimljiva jer uobičajena satelitska metodologija, bazirana na MODIS satelitu, nije funkcionalna u ovim oblastima zbog nedovoljne prostorne rezolucije senzora. U ovom radu je predstavljen pristup procjeni koncentracija klorofila-a baziran na Landsat 8 satelitskim snimcima i mjerenjima koncentracije obavljenim na određenim lokacijama na dan prelijetanja satelita. Dodatno, dva klasifikatora stanja (dnevni i godišnji) eutrofikacije, koji koriste određene koncentracije, su također prikazani. Preciznost predloženih metoda je procijenjena koristeći „leave-one-out“ unakrsnu validaciju, te rezultati pokazuju da je preciznost unutar teoretskih limita metoda baziranih na Ladsat 8 satelitu. Rezultati klasifikatora upoređeni su sa mjerenjima na terenu i pokazuju da je dnevni klasifikator u mogućnosti da klasificira oblast od interesa sa manje of 2% pogreški.This study proposes a methodology for monitoring concentrations of chlorophyll a (Chl-a) and the state of eutrophics in small bays or in the immediate vicinity of the coast. This kind of monitoring is of interest since such areas have not been addressed well using the usual satellite methods (such as MODIS) due to inadequate spatial resolution. We present an estimation approach for Chl-a concentration based on Landsat 8 (L8) satellite images using the ground truth (GT) data for the day of overflight. Additionally, two classifiers (daily and yearly) of the state of eutrophication, that use the Chl-a estimated values, are presented. The accuracy of the proposed method is evaluated using the leave-one-out cross validation, and it is within limits theoretically expected of an L8-based approach. The results from the classifiers are compared with the GT data and it is shown that daily classifier is able to classify the area of interest with an incidence of false positives less than 2%

Proteinsko-energetski gubitak kod bolesnika na hroničnoj hemodijalizi - etiologija i dijagnostički kriterijumi

The available evidence suggests that nutritional status in the HD patients is an extremely important predictive and causative factor for the good clinical outcome. Nutritional deficits and PEW are frequent problems in the dialysis population and implies an increased risk of negative health outcomes such as mortality risk and quality of life deterioration. There is no single specific measurement that provides complete assessment of the nutritional status in the HD patients, and the results should be analysed in the clinical context of each individual patients. As malnutrition is potentially reversible with appropriate nutritional support, early identification of patients at high nutritional risk may facilitate effective treatment and improve prognosis in the HD patients.

In vitro procena citotoksičnosti 3D štampanog polimera na bazi epoksi smole namenjenog za upotrebu u stomatologiji

Background/Aim. There is limited published evidence on the cytotoxicity of 3D printed polymer materials for dentistry applications, despite that they are now widely used in medicine. Stereolithography (SLA) is one of the foremost 3D processes used in 3D printing, yet there are only a small number of resin materials reported to be suitable for medical applications. The aim of this study was to investigate, in vitro, the cytotoxic effect of the 3D printed resin in order to establish the suitability for its usage in dentistry and related medical applications such as surgical dental guides, occlusal splits and orthodontic devices. Methods. To examine the cytotoxicity of the 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA), two cell cultures were used: mouse fibroblasts L929, and human lung fibroblasts MRC-5. The cell viability was determined by the Mosmann's colorimetric (MTT) test and the agar diffusion test (ADT). Results. Direct contact of the tested material with the ADT test showed nontoxic effects of tested material in any cell culture. The tested material showed no cytotoxic effect after 3 days of extraction of the eluate by the MTT, but mild cytotoxic effect after 5, 7 and 21 days on both cell lines. The cytotoxicity increased with increasing the time of the eluate extraction. Conclusion. The 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA) is considered appropriate for making surgical dental implant guides according to the cytotoxic behavior. According to the mild level of cytotoxicity after the longer extraction periods, there is a need for further evaluation of biocompatibility for its application for the occlusal splints and orthodontic devices.Uvod/Cilj. Malo je objavljenih dokaza o citotoksičnosti 3D štampanih polimernih materijala za upotrebu u stomatologiji, bez obzira na njihovu sve širu primenu u medicini. Stereolitografija (SLA) jedan je od najvažnijih 3D procesa koji se primenjuje za 3D štampu, ali postoji samo Mali broj materijala na bazi smola za koje je dokazano da su pogodni za medicinsku primenu. Cilj ove studije je bio da se ispita, in vitro, citotoksični efekat 3D štampanog polimera kako bi se utvrdila mogućnost za njegovu upotrebu u stomatologiji i srodnim medicinskim oblastima, kao što su hirurške dentalne vođice, okluzalni splintovi i ortodontski aparati. Metode. Da bi se ispitala citotoksičnost 3D štampanog polimera na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA), korišc'ene su dve c'elijske kulture: fibroblasti miša L929 i humani fibroplasti pluc'a MRC-5. Vijabilnost c'elija utvrđena je Mosmannovim kolorimetrijskim testom (MTT) i testom difuzije agara (ADT). Rezultati. Direktan kontakt testiranog materijala ispitan pomoću ADT pokazao je da materijal nije imao citotoksičan efekat ni na jednu ćelijsku kulturu. Testitrani materijal je imao blag citotoksični efekat posle 5, 7 i 21 dana ekstrakcije eluata primenom MTT na obe ćelijske linije. Citotoksičnost je rasla sa produženjem vremena ekstrakcije eluata. Zaključak. 3D štampani polimer na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA) se može smatrati pogodnim za izradu hirurških dentalnih implantnih vođica sa tačke gledišta njegovog citotoksičnog uticaja. Zbog pokazanih blagih citotoksičnih efekata nakon dužih ekstrakcionih perioda eluata potrebna su dalja istraživanja u oblasti biokompatibilnosti materijala da bi se taj polimer mogao koristiti za izradu okluzalnih splintova i ortodontskih aparata

Forage yield of a grass-clover mixture on an acid soil in the third year after soil liming

Soil acidity is one of the most common reasons for low yields of forage crops. This paper analyzes the long-term effect of liming (control - without CaO; 3 t*ha-1 CaO; 6 t*ha-1 CaO) applied to an acid soil (pHH2O 4.8) before stand establishment on the productivity of a mixture of red clover (Trifolium pratense L.) and tall oat grass (Arrhenatherum elatius L.) during the third year of production. Soil liming significantly increased hay yields in the first and second cuts by 17-25% and 46%, respectively, which resulted from an increase in the total yield and dry matter content of forage. In the third cut, soil liming had no effect on forage and hay yields due to the lower amount of precipitation in the second part of the growing season. Both lime application rates led to a significant reduction in the percentage of red clover in the first and second cuts, thus favoring the percentage of tall oat grass. In the third cut, only the percentage of weeds was lower in both lime treatments, as it decreased by more than 55% compared to the control

Determination of Microelements in Human Milk and Infant Formula Without Digestion by ICP-OES

The concentrations of zinc (Zn), iron (Fe) and copper (Cu) in both human milk and infant formula were determined using a new sample preparation method, by inductively coupled plasma -optical emission spectometry (ICP-OES) and flame atomic absorption spectrometry (FAAS). Human milk samples were diluted in ultrapure water. The infant formula of powder samples (suitable for an infant 1-6 months of age) and standard reference material (SRM-1849) were analyzed in parallel. The results have shown that FAAS method was more sensitive for Fe determination in human milk while ICP-OES was more sensitive for both Zn and Cu detection. The limit of quantification for both Zn and Cu was 5 mu g L-1 and 10 mu g L-1 for Fe and the recovery for Zn, Fe and Cu was ranged from 90% to 94%, 97% to 103% and 90% to 102%, respectively. Mean concentrations of Zn, Fe, and Cu in human milk samples were 5.35, 0.47 and 0.83 mg L-1, respectively while these values in infant formula were ranged from 3.52-4.75 mg L-1, 3.37-4.56 mg L-1 and 0.28-0.41 mg L-1, respectively. Despite the sample complexity, the proposed method using dilution of milk samples with water was simple, rapid, effective and accurate. ICP-OES was a better method for Zn determination while FAAS was a better method for Fe determination. In the case of Cu both methods were comparable

Professional exposure to ionizing radiation and the occurrence of cataract

Radiation cataract is one of ensuing effects of ionizing radiation, since its threshold dose under which it does not occur, and above which it shows dose dependency, has been observed. Clinical course of radiation cataract is identical for all the types of ionizing radiation and is very typical. Minimal dose for progressive cataract formation is determined by the type of radiation, i.e., its relative biological efficacy, dose, and the duration of the exposure period. Theoretically, threshold dose existence does not exclude the incidence of cataract formation under significantly smaller doses, as well. The aim of this study was to analyze the incidence of cataract formation among the medical staff professionally exposed to ionizing radiation. Neither of the diagnosed cataracts had typical morphology, nor was the correlation established between the dose, exposure time, and the cataract formation. All the diagnosed cataracts were described as premature, and therefore ionizing radiation was considered as a co-factor in premature cataract formation in the examined groups

Extraskeletal activity of vitamin D and a potential association with diabetes mellitus

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Termička degradacija nanokompozita poli(metil metakrilat)/silicijum-karbid

The thermal stability of poly(methyl methacrylate) (PMMA) and silicon carbide (SiC) composites was studied by thermogravimetry. The influence of particle size, SiC structural modification and particle specific surface was analyzed. It was established that particle size had the greatest influence on PMMA/SiC thermal stability and that the most stable composites were those with the smallest particle diameter, i.e the largest particle specific surface. The values of the thermal degradation activation energy indicated that in some cases particle deagglomeration probably did occur which enabled polymer-filler nanoscale interaction and indicated that the system PMMA/SiC could form nanocomposites.U ovom radu je ispitana termička stabilnost kompozita poli(metil metakrilata) (PMMA) i silicijum-karbida (SiC) termogravimetrijom. Analiziran je uticaj veličine čestica, strukturne modiflkacije i specifične površine čestica SiC na termičku stabilnost kompozitnog materijala. Utvrđeno je da najveći uticaj na termičku stabilnost kompozita PMMA/SiC ima veličina čestica i da su najstabiiniji kompoziti sa najmanjim prečnikom čestica odnosno najvećom specifičnom površinom. Vrednosti energije aktivacije termičke degradacije materijala su ukazale da u nekim slučajevima u kompozitu verovatno dolazi do deaglomeracije čestica SiC što omogućava interakciju polimera i punila na nanometarskom nivou i ukazuje da sistem PMMA/SiC može da obrazuje nanokompozite