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Olayinka O. Ajani, Martins T. Nlebemuo, Joseph A. Adekoya, Kehinde O. Ogunniran, Tolutope O. Siyanbola and Christiana O. Ajanaku

Abstract

Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast rate of spreading in all parts of the world. Tireless commitment to searching for novel therapeutic medicines is a worthwhile adventure in synthetic chemistry because of the drug resistance predicament and regular outbreak of new diseases due to abnormal cell growth and proliferation. Medicinal chemistry researchers and pharmacists have unveiled quinoxaline templates as precursors of importance and valuable intermediates in drug discovery because they have been established to possess diverse pharmacological potentials. Hence, this review highlights the current versatile routes to accessing functionalized quinoxaline motifs and harnessing their documented therapeutic potentials for anticancer drug development.

Open access

Zuzana Allmanová, Mária Vlčková, Martin Jankovský, Matúš Jakubis and Michal Allman

Abstract

This paper focused on predicting the bank erosion through the Bank Assessment for Non-point source Consequences of Sediment (BANCS) model on the Tŕstie water stream, located in the western Slovakia. In 2014, 18 experimental sections were established on the stream. These were assessed through the Bank Erosion Hazard Index (BEHI) and the Near Bank Stress (NBS) index. Based on the data we gathered, we constructed two erosion prediction curves. One was for BEHI categories low and moderate, and one for high, very high, and extreme BEHI. Erosion predicted through the model correlated strongly with the real annual bank erosion – for low and moderate BEHI, the R2 was 0.51, and for high, very high and extreme BEHI, the R2 was 0.66. Our results confirmed that the bank erosion can be predicted with sufficient precision on said stream through the BANCS model.

Open access

Narjes Azizi, Masoud Sheidai, Valiollah Mozaffarian, Mitra Arman and Zahra Noormohammadi

Abstract

This study conducted to determine relationship among and within Iranian Helichrysum species (Asteraceae). In this study based on ISSR markers, the highest percentage of ISSR loci polymorphism (54.7%) occurred in H. armenium. The highest gene diversity over loci (1.224), Shannon’s Information Index (0.224%) and Expected Heterozygosity (0.142%) occurred in H. armenium (0.18) and the lowest of these parameters (0%) were observed in H. araxinum, H. graveolens, H. persicum and H. psychrophilum. The highest genetic similarity occurred between H. armenium and H. rubicundum (0.989), while the lowest was between H. polyphyllum and H. graveolens (0.213). The analysis of molecular variance (AMOVA), showed significant genetic variation among (24%) and within (76%) species. In morphological analysis traits such as indumentum, resting bud, achene length, achenial papillae, dimension of receptacle and form and apex of phyllaries were main diagnostic features. Results obtained from the morphological cluster were greatly consistent with the molecular data, to elucidating taxonomic relationships, as well as both attributed the higher diversity in H. armenium and H. rubicundum in comparison with other species and also indicated that H. persicum is a member of H. oocephalum species. Totally we confirmed the presence of 18 species in Iran.

Open access

Jaime G. Cuevas, José L. Arumí and José Dörner

Abstract

Lagtimes and times of concentration are frequently determined parameters in hydrological design and greatly aid in understanding natural watershed dynamics. In unmonitored catchments, they are usually calculated using empirical or semiempirical equations developed in other studies, without critically considering where those equations were obtained and what basic assumptions they entailed. In this study, we determined the lagtimes (LT) between the middle point of rainfall events and the discharge peaks in a watershed characterized by volcanic soils and swamp forests in southern Chile. Our results were compared with calculations from 24 equations found in the literature. The mean LT for 100 episodes was 20 hours (ranging between 0.6–58.5 hours). Most formulae that only included physiographic predictors severely underestimated the mean LT, while those including the rainfall intensity or stream velocity showed better agreement with the average value. The duration of the rainfall events related significantly and positively with LTs. Thus, we accounted for varying LTs within the same watershed by including the rainfall duration in the equations that showed the best results, consequently improving our predictions. Izzard and velocity methods are recommended, and we suggest that lagtimes and times of concentration must be locally determined with hyetograph-hydrograph analyses, in addition to explicitly considering precipitation patterns.

Open access

Livio Poldini and Stefano Tasinazzo

Abstract

Recent original data concerning vineyard spring vegetation from Veneto hilly belt (North-eastern Italy) highlighted once again the phytogeographic originality of south-eastern territories with respect to Central European ones, also in anthropogenic coenosis. New relevés suggested to restate the association Cerastio tenoreani-Geranietum dissecti as vicarious vegetation of Geranio rotundifolii-Allietum vinealis occurring on the north side of the Alps. The comparison of autumn material from terracing vineyards of the sandy-marly Eocene flysch around Trieste coast with similar European relevés enabled to reject the not validly described Anagallido-Mercurialetum and to replace it with Mercurialetum annuae. In modern winegrowing Cerastio-Geranietum and Mercurialetum annuae are vanishing due to changing of agronomic schemes, as some relevés reported in the text document.

Open access

Saša Polović, Vanja Ljoljić Bilić, Ana Budimir, Darko Kontrec, Nives Galić and Ivan Kosalec

Abstract

Aroylhydrazones 1–13 were screened for antimicrobial and antibiofilm activities in vitro. N′-(2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (2), N′-(5-chloro-2-hydroxyphenyl-methylidene)-3-pyridinecarbohydrazide (10), N′-(3,5-chloro-2-hydroxyphenylmethylidene)-3-pyridinecarbohydrazide (11), and N′-(2-hydroxy-5-nitrophenylmethylidene)-3-pyridinecarbohydrazide (12) showed antibacterial activity against Escherichia coli, with MIC values (in µmol mL−1) of 0.18–0.23, 0.11–0.20, 0.16–0.17 and 0.35–0.37, resp. Compounds 11 and 12, as well as N′-(2-hydroxy-3-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (6) and N′-(2-hydroxy-5- methoxyphenylmethylidene)-3-pyridinecarbohydrazide (8) showed antibacterial activity against Staphylococcus aureus, with the lowest MIC values of 0.005–0.2, 0.05–0.12, 0.06–0.48 and 0.17–0.99 µmol mL−1. N′-(2-hydroxy-5-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (7) showed antifungal activity against both fluconazole resistant and susceptible C. albicans strains with IC 90 range of 0.18–0.1 µmol mL−1. Only compound 11 showed activity against C. albicans ATCC 10231 comparable to the activity of nystatin (the lowest MIC 4.0 ×10−2 vs. 1.7 × 10−2 µmol mL−1). Good activity regarding multi-resistant clinical strains was observed for compound 12 against MRSA strain (MIC 0.02 µmol mL−1) and compounds 2, 6 and 12 against ESBL+ E. coli MFBF 12794, with the lowest MIC for compound 12 (IC 50 0.16 µmol mL−1). Anti-biofilm activity was found for compounds 2 (MBFIC 0.015–0.02 µmol mL−1 against MRSA) and 12 (MBFIC 0.013 µmol mL−1 against EBSL+ E. coli). In the case of compound 2 against MRSA biofilm formation, MBFIC values were comparable to those of gentamicin sulphate, whereas in the case of compound 12 and EBSL+ E. coli even more favourable activity compared to gentamicin was observed.

Open access

Igor Dakskobler and Livio Poldini

Abstract

We conducted a phytosociological study of alpine grasslands with dominant Luzula alpinopilosa in the Julian and Carnic Alps. Based on a comparison with similar communities elsewhere in the Alps we described a new association Junco jacquinii-Luzuletum alpinopilosae, which we classify into the provisional alliance Doronico glacialis-Juncion jacquinii, order Festucetalia spadiceae and class Juncetea trifidi. The new association characterises moist shady grasslands in gullies and on ledges on limestone admixed with marlstone and chert, in the elevation range between 2000 and 2500 m, where the snow cover persists for extended periods. We distinguish three subassociations: -galietosum anisophyllae (the most calcareous form), -potentilletosum aureae (typical form) and -leucanthemopsietosum alpinae (acidophilic form on Werfen sandstones in the Carnic Alps, which is the most similar to the stands of the association Luzuletum alpinopilosae from the Central Alps).

Open access

Shan Xiong, Jinglai Li, Yanling Mu and Zhenqing Zhang

Abstract

Morroniside is one of the most important iridoid glycosides from Cornus officinalis Sieb. et Zucc. In the present study, the pharmacokinetics and bioavailability studies of morroniside were conducted on Sprague-Dawley (SD) rats. A rat in situ intestinal perfusion model was used to characterize the absorption of morroniside. Caco-2 cells were used to examine the transport mechanisms of morroniside. The pharmacokinetic study of morroniside exhibited linear dose-proportional pharmacokinetic characteristics and low bioavailability (4.3 %) in SD rats. Its average P eff value for transport across the small intestinal segments changed from (3.09 ± 2.03) × 10−6 to (4.53 ± 0.94) × 10−6 cm s−1. In Caco-2 cells, the P app values ranged from (1.61 ± 0.53) × 10−9 to (1.19 ± 0.22) × 10−7 cm s−1 for the apical to basolateral side and the P ratio values at three concentrations were all lower than 1.2. Morroniside showed poor absorption and it might not be a specific substrate of P-glycoprotein (P-gp).