12 research outputs found
Cortical index of the femur in rats exposed to some toxic metals and ash from coal gasification
Sadržaj minerala u kosti podlaktice u zdravih odraslih osoba
Bone mineral content (BMC) in the forearm was measured in 256 healthy adult persons (114 men and 142 women) by the 241Am gramma ray attenuation method. The BMC decreased with in-creasing age after reaching a maximum, and was greater in men than in women.Sadržaj minerala u kosti podlaktice mjeren je metodom atenuacije (gašenja) gama-zraka 241Am u 256 zdravih osoba (114 muškaraca i 142 žene). Sadržaj opada s dobi nakon što postigne maksimum u dobi između 30 i 40 godina a viši je u muškaraca negoli u žena. Rezultati ovih istraživanja primjenjivat će se u ispitivanjima bolesti i faktora koji utječu na sadržaj minerala u kostima populacije u Hrvatsko
Nitrogen Removal from Municipal Landfill Leachate
The aim of this work was to investigate the efficiency of nitrogen removal from municipal landfill leachate with a microbial culture in 3 L batch bioreactor. The microbial culture, originating from landfill leachate, was prepared by an enrichment culture technique.
Organic compounds measured as chemical oxygen demand (COD) of 400–600 mg L–1 and high concentrations of ammonium nitrogen (NH4
+-N) 270–312 mg L–1 characterized the landfill leachate as a mature leachate. The rate of ammonium nitrogen removal was 24.5 mg NH4
+-N L–1 h–1. Nitrification rate was 20.1 mg NOx–-N L–1 h–1. Denitrification was performed with the addition of sodium acetate as external carbon source in ratio C/N 2 and 4. Sodium acetate was insufficient for complete denitrification at C/N 2. Complete denitrification at C/N 4 was performed at denitrification rate 8.3 mg NO3–-N L–1 h–1
Nitrogen Removal from Municipal Landfill Leachate
The aim of this work was to investigate the efficiency of nitrogen removal from municipal landfill leachate with a microbial culture in 3 L batch bioreactor. The microbial culture, originating from landfill leachate, was prepared by an enrichment culture technique.
Organic compounds measured as chemical oxygen demand (COD) of 400–600 mg L–1 and high concentrations of ammonium nitrogen (NH4
+-N) 270–312 mg L–1 characterized the landfill leachate as a mature leachate. The rate of ammonium nitrogen removal was 24.5 mg NH4
+-N L–1 h–1. Nitrification rate was 20.1 mg NOx–-N L–1 h–1. Denitrification was performed with the addition of sodium acetate as external carbon source in ratio C/N 2 and 4. Sodium acetate was insufficient for complete denitrification at C/N 2. Complete denitrification at C/N 4 was performed at denitrification rate 8.3 mg NO3–-N L–1 h–1
Polymer Chemical Identity as a Key Factor in Microplastic–Insecticide Antagonistic Effects during Embryogenesis of Sea Urchin <i>Arbacia lixula</i>
As a proxy for pollutants that may be simultaneously present in urban wastewater streams, the effects of two microplastics—polystyrene (PS; 10, 80 and 230 μm diameter) and polymethylmethacrylate (PMMA; 10 and 50 μm diameter)—on fertilisation and embryogenesis in the sea urchin Arbacia lixula with co-exposure to the pyrethroid insecticide cypermethrin were investigated. Synergistic or additive effects were not seen for plastic microparticles (50 mg L−1) in combination with cypermethrin (10 and 1000 μg L−1) based on evaluation of skeletal abnormalities or arrested development and death of significant numbers of larvae during the embryotoxicity assay. This behaviour was also apparent for male gametes pretreated with PS and PMMA microplastics and cypermethrin, where a reduction in sperm fertilisation ability was not evidenced. However, a modest reduction in the quality of the offspring was noted, suggesting that there may be some transmissible damage to the zygotes. PMMA microparticles were more readily taken up than PS microparticles, which could suggest surface chemical identity as potentially modulating the affinity of larvae for specific plastics. In contrast, significantly reduced toxicity was noted for the combination of PMMA microparticles and cypermethrin (100 μg L−1), and may be related to less ready desorption of the pyrethroid than PS, as well as cypermethrin activating mechanisms that result in reduced feeding and hence decreased ingestion of microparticles
Phenolics, fatty acids, and biological potential of selected Croatian EVOOs
Nutritional value of extra virgin olive oil is associated with its complex chemical composition. The aim of this study was to determine phenolic secoiridoids in Extra virgin olive oils (EVOOs) from autochthonous Croatian cultivars (Drobnica, Krvavica, Lastovka, and Oblica) by qNMR, to determine simple phenolics by UPLC, as well as to analyze the fatty acid profile, the antioxidant activity, and the oxidative stability of selected oils. This is the first study on chemical and biological characterization of selected autochthonous olives varieties. Drobnica EVOO contained the highest amount of total phenols and major secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycon, and ligstroside aglycon) compared to other oils. The antioxidant activity of Drobnica phenolics was very high by FRAP and copper-induced LDL oxidation assays, while the oxidative stability of Drobnica oil by Rancimat method was very long (23 h). Practical applications: This study represents the contribution to the research of chemical and biological potential of monovarietal extra virgin olive oil from Croatia. EVOOs from selected Croatian autochthonous cultivars had very high phenolic content that is related to high inhibitory rate of copper-induced oxidation of human LDL as well as the long oxidative stability. Drobnica EVOO showed very long oxidative stability. EFSA approved health claim on olive oil polyphenols (EU, 432/2012) and selected Croatian cultivars, especially Drobnica, are of interest due to its high phenolic content and strong biological potential. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
Do Biotic and Abiotic Factors Influence the Prevalence of a Common Parasite of the Invasive Alien Ladybird Harmonia axyridis?
Hesperomyces virescens (Ascomycota, Laboulbeniales), a fungal ectoparasite, is thus far reported on Harmonia axyridis from five continents: North and South America, Europe, Africa, and Asia. While it is known that He. virescens can cause mortality of Ha. axyridis under laboratory conditions, the role of biotic and abiotic factors in influencing the distribution of He. virescens in the field is unknown. We collected and screened 3,568 adult Ha. axyridis from 23 locations in seven countries in Central Europe between October and November 2018 to test the effect of selected host characters and climate and landscape variables on the infection probability with He. virescens. Mean parasite prevalence of He. virescens on Ha. axyridis was 17.9%, ranging among samples from 0 to 46.4%. Host sex, climate, and landscape composition did not have any significant effect on the infection probability of He. virescens on Ha. axyridis. Two color forms, f. conspicua and f. spectabilis, had a significantly lower parasite prevalence compared to the common Ha. axyridis f. novemdecimsignata.</jats:p