Browse

You are looking at 1 - 10 of 2,339 items for :

Clear All
Open access

Amina S. Yusuf, Ibrahim Sada, Yusuf Hassan, Temitope O. Olomola, Christiana M. Adeyemi and Sunday O. Ajibade

Abstract

The synthesis of five monocarbonyl analogues of curcumin is described. In vitro anti-malarial assay of the compounds was carried out and the effect of the substituents on the aryl ring has been described. The results show that all the five compounds exhibited some reasonable activity against the chloroquine-resistant plasmodium parasite. Molecular docking studies further confirmed the observed biological activity of the compounds.

Open access

Nivrati Jain, Harshita Jain, Ashish Jain, Veerasamy Ravichandran and Prateek Jain

Abstract

We described here the synthesis and biological evaluation of a series of 2, 4, 6-trisubstituted quinazoline derivatives as potential anti-inflammatory, analgesic and antibacterial agents. The synthesized compounds were characterized by FTIR, 1H NMR and mass spectroscopy analysis. We found that the compounds 6b, 6e, 6g, 6h and 6j showed better anti-inflammatory activity than indomethacin. Compounds 6b, 6e, 6h, 6j and 6l were found to exhibit appreciable analgesic activity, and 6b, 6g and 6k showed good antibacterial activity against Gram (+) bacteria: B. subtilis, S. aureus, S. epidermis, and Gram (-) bacteria: E. coli, P. aeruginosa and K. pneumoniae. Compound 6b showed overall better anti-inflammatory, analgesic and antibacterial activity among the synthesized compounds. The results of the present study could be helpful for the designing of effective anti-inflammatory, analgesic and antibacterial agents.

Open access

Wojciech Starosta, Viera K. Semina, Jerzy Smolik, Lech Waliś, Michał Rydzewski and Bożena Sartowska

Abstract

Zirconium alloys used widely in nuclear industry as fuel claddings are prone to violent oxidation in water steam atmosphere in the case of loss of coolant accident (LOCA). Accompanying generation of large quantities of heat and explosive gaseous hydrogen may lead to destruction of nuclear core. As the safety of nuclear installations is of primary importance, intensive research works are conducted on the development of so-called accident tolerant fuels much less prone to oxidation. In this paper, the application of external zirconium-silicide coatings deposited by magnetron sputtering is proposed. The preliminary results of their synthesis and studies of air oxidation properties at elevated temperatures are presented.

Open access

Viktoria Volodina, Natalia Karygina, Olga Popova, Elmira Popova, Mariia Grushko and Nadezhda Fedorova

Abstract

The toxicological study conducted revealed high concentrations of hydrocarbons and highly toxic heavy metals in the liver and subcutaneous fat of the Caspian seal. The increased toxicant level in the fat, as compared to the liver, pointed to the disorder of organism purification processes, leading to chronic polytoxicosis and disorders of the histological structure of the internals. The studies of the morphofunctional state of the stomach of the Caspian pinnipeds revealed the following disorders: hemorrhages, edemata and necrosis of the mucous membrane, and replacement of glandular tissue with the connective tissue. The study of the small intestine of the seals identified the symptoms of catarrhal desquamatory enteritis. Epithelium dystrophy and desquamation were noted, in particular at the tops of the villi. Different types of colitis (acute, ulcerative, chronic) were found in the large intestine of the seals. Dystrophic and necrotic changes of hepatocytes were identified in the liver tissue, which pointed to the liver cell failure. The nature and extent of pathological changes in the internals and tissues of the studied animals point to the functional depression of the digestive system.

Open access

Linda Abi-Ayad, Sidi-Mohammed Bahae-Ddine Ghezlaoui, Nassereddine Belkhouche and José Morillo Aguado

Abstract

This work brings an evaluation of the quality of littoral zone of Algerian in two neighbouring port coasts, namely, Honaine and Beni Saf, chosen as significant discharge sites. This was followed by a comparison of the state of these coasts with those of the Mediterranean coastal areas. The study was conducted in all seasons in the year 2011−2012 by measuring the hydrological physicochemical parameters (pH, temperature, turbidity and salinity) and using sea lettuce Ulva lactuca as significant ‘biomarker of the quantity of metal contaminants (Cd, Pb, Cu and Zn)’. Harvesting of Ulva and the seawater samples were performed in each season in three stations, characterised by discharges of waste and industrial water and saline discharges from the recent installation of desalination in Honaine. The metal concentrations in seawater showed significant variations between stations and the harvest season, resulting in the appearance of pollution of Cd, Pb, Cu and Zn. Also this result was manifested in Ulva in the station S1 (Beni Saf) and S2 (Honaine-beach) with the exception of copper. These results have exceeded tolerable international standards.

Open access

Joan S. Adriano, Glenn G. Oyong, Esperanza C. Cabrera and Jose Isagani B. Janairo

Abstract

The field of microbial biotechnology has revolutionized the utilization of microorganisms to overcome the problems of environmental pollutions. The present study aimed to identify silver-tolerant isolates and screen their ability to synthesize silver nanoparticles for possible use as bioremediation agents. Seventeen bacterial isolates from soil collected from the Smokey Mountain landfill in Manila, Philippines, were found to tolerate 0.01 M AgNO3 in the culture medium. Molecular and phylogenetic analyses using the 16S rRNA gene sequence identified the isolates as Bacillus cereus, Bacillus subtilis, Bacillus flexus, Bacillus thuringiensis, Alcaligenes faecalis, Achromobacter sp. and Ochrobactrum sp. The formation of silver nanoparticles was evident in the change in color of the reaction mixtures, and was detected through UV-VIS spectroscopy with absorbance peaks at 250-300 nm and 400-450 nm. Scanning electron microscopy revealed the aggregation of diverse shapes of silver nanoparticles with sizes ranging from 70 to 200 nm. The best silver nanoparticle-synthesizing isolates were Alcaligenes faecalis and Bacillus cereus. The results denote the promising microbial technology application of the 17 silver-tolerant isolates in combating the adverse effects of metals and other pollutants in the environment.

Open access

Ilona Wrońska and Krystyna Cybulska

Abstract

One of the methods for recovery and utilization of waste products from the poultry industry is to subject them to the methane fermentation process in the biogas plant. These are waste with a high content of fatty compounds and proteins, including keratin. Their specificity is characterized by rapid possibility of spoilage, rancidity and problems of further management. These wastes are characterized by varying degrees of complexity, thus their use as a raw material for the biogas fermenter should be preceded by a pre-treatment. An example of waste generated in poultry processing is biological sludge. Optimizing this material with highly enzymatic fungi could accelerate the degradation of the organic matter contained and, as a result, increase the energy efficiency of this type of waste. Quantitative and qualitative parameters of biogas produced from biological sludge processed by isolated filamentous fungi with high metabolic potential were determined. Laboratory tests were based on the modified methodology included in the standards DIN 38414-S8 and VDI 4630. Based on the results obtained, it was found that the pre-optimization of biological sludge by fungal strains with different metabolic potential, influences on the yield of biogas production, including methane. There was an increase in the biogas yield from the biological sludge processed by the mixed fungal consortium (by 20 %) and the strain marked as F1 (by 14 %) as compared to the non-inoculated material, which was also reflected in the amount of methane produced in the case of the mixed fungal consortium (by 28 %) and the strain marked as F1 (by 12 %).

Open access

Svetlana Volodarets, Aleksandr Glukhov and Irina Zaitseva

Abstract

The study of phytoncide activity of biogenic volatile organic compounds of woody plants is one of the most important areas of research in plant ecology in urban lands. The aim of this work is to investigate the dependence of the phytoncide activity of some woody plant species from meteorological factors in the urban environment in the steppe zone of Ukraine. The objectives of the investigation were 28 species of trees and shrubs. The air temperature is indicated to be a major factor for drought-resistant and some medium drought-resistant species (Populus simonii Carrière, Armeniaca vulgaris L., Robinia pseudoacacia L., Acer pseudoplatanus L., Malus niedzwetzkyana Dieck). The phytoncide activity of low and medium drought-resistant species (Viburnum opulus L., Acer sacharinnum L.) depends on air humidity and total monthly precipitation. The obtained results make it possible to predict changes in the phytoncide activity of woody plants, when selecting the assortment of species for phyto-optimization of technogenic environment.

Open access

Mikołaj Oettingen and Przemysław Stanisz

Abstract

This paper describes the methodology developed for the numerical reconstruction and modelling of the thorium-lead (Th-Pb) assembly available at the Department of Nuclear Energy, Faculty of Energy and Fuels, AGH University, Krakow, Poland. This numerical study is the first step towards integral irradiation experiments in the Th-Pb environment. The continuous-energy Monte Carlo burnup (MCB) code available on supercomputer Prometheus of ACK Cyfronet AGH was applied for numerical modelling. The assembly consists of a hexagonal array of ThO2 fuel rods and metallic Pb rods. The design allows for different arrangements of the rods for various types of irradiations and experimental measurements. The intensity of the fresh neutron source intended for integral experiments is about 108 n/s, which corresponds to the mass of about 43 μg 252Cf. The source was modelled in the form of Cf2O3-Pd cermet wire embedded in two stainless steel capsules.