Spectroscopic,electrochemical, theoretical characterization and biological evaluation of a ferrocenyl-substituted unsymmetric azine ligand and its Cu(II) complex

Ferrocenyl-substituted unsymmetrical azine and its Cu(II) complex were prepared. The redox active ferrocene-based azine was obtained by condensation of 1-[(E)-hydrazono]-5-bromo-2-hydroxybenzene with ferrocene carboxaldehyde. The ferrocenyl ligand and its Cu(II) complex were characterized by IR, UV–vis, NMR, X-ray, magnetic susceptibility, molar electrical conductivity measurements, and TG techniques. The redox behaviors of the ferrocene compounds were investigated by cyclic voltammetry. Structural parameters and spectroscopic properties of the ligand and the Cu(II) complex were calculated by employing density functional theory (DFT) and time-dependent DFT and compared with available experimental data. We found slightly stronger binding ability for Cu(II) complex than the free ligand. DNA binding abilities for ferrocenyl-substituted unsymmetrical azine ligand and its Cu(II) complex are higher than some reported ferrocene compounds. We also studied DNA cleavage, superoxide and DPPH radical scavenging abilities of the compounds. Furthermore, the synthesized organometallic compounds can be bound to DNA through an intercalative mode.     

Effects of European mistletoe (Viscum album L. subsp. album) extracts on activity rhythms of the Syrian hamsters (Mesocricetus auratus)

Antitumor drugs may have some significant nervous system side-effects such as disrupted sleep, eating and drinking patterns. European Mistletoe has been investigated for many decades for its potential use against cancer. To test the hypothesis that the non-antineoplastic effects of mistletoe might be mediated by the actions on the circadian timing system, we have applied mistletoe extracts and vehicle and have measured locomotor activity, feeding and drinking rhythms under constant darkness. Four groups (vehicle, 20 mg kg(-1) ip injection, 40 mg kg(-1) ip injection and 6 g kg(-1) oral administration) were performed for both heat-treated and freeze-dried extracts. None of the administrations changed the locomotor activity, feeding and drinking rhythms in the groups except for 40 mg kg(-1) freeze-dried injected group. The locomotor activity levels decreased in 40 mg kg(-1) freeze-dried extract injected group. These results suggest that, side-effects of mistletoe on circadian timing system of the Syrian hamster depend on the dose and the preparation method of the extract.     

Importance of LPS structure on protein interactions with Pseudomonas aeruginosa

Atomic force microscopy (AFM) was used to quantify the adhesion forces between Pseudomonas aeruginosa PAO1 and AK1401, and a representative model protein, bovine serum albumin (BSA). The two bacteria strains differ in terms of the structure of their lipopolysaccharide (LPS) layers. While PAO1 is the wild-type expressing a complete LPS and two types of saccharide units in the O-antigen (A(+) B(+)), the mutant AK1401 expresses only a single unit of the A-band saccharide (A(+) B(-)). The mean adhesion force (F(adh)) between BSA and AK1401 was 1.12 nN, compared to 0.40 nN for F(adh) between BSA and PAO1. In order to better understand the fundamental forces that would control bacterial-protein interactions at equilibrium conditions, we calculated interfacial free energies using the van Oss-Chaudhury-Good (VCG) thermodynamic modeling approach. The hydrogen bond strength was also calculated using a Poisson statistical analysis. AK1401 has a higher ability to participate in hydrogen bonding with BSA than does PAO1, which may be because the short A-band and absence of B-band polymer allowed the core oligosaccharides and lipid A regions to be more exposed and to participate in hydrogen and chemical bonding. Interactions between PAO1 and BSA were weak due to the dominance of neutral and hydrophilic sugars of the A-band polymer. These results show that bacterial interactions with protein-coated surfaces will depend on the types of bonds that can form between bacterial surface macromolecules and the protein. We suggest that strategies to prevent bacterial colonization of biomaterials can focus on inhibiting these bonds.     

Experimental and theoretical structural studies on 4-(2-phenylethyl)-5-(2-furyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione

The structural and conformational features of 4-(2-phenylethyl)-5-(2-furyl)-2, 4-dihydro-3H-1,2,4-triazole-3-thione (1a), which can be related to the biological activity, have been investigated by X-ray diffraction and molecular modeling techniques. Ab initio method (RHF/6-31G) and density functional theory (B3LYP/6-31G(D)) have been used to calculate structural parameters, conformations, and relative energy of two tautomeric specious (1a and 1b) of the title compound. The geometry and the conformation of the thione form, 1a, is well reproduced by the DFT (B3LYP/6-31G(D)) method as compared with X-ray structure in which this form is found. The thione form is also predicted to be 14.42 kcal/mol more stable than the thiol form in the gas-phase by the DFT method.     

On symmetries,conservation laws and exact solutions of the nonlinear Schrödinger–Hirota equation

In this paper, conservation laws and exact solution are found for nonlinear Schrödinger–Hirota equation. Conservation theorem is used for finding conservation laws. We get modified conservation laws for given equation. Modified simple equation method is used to obtain the exact solutions of the nonlinear Schrödinger–Hirota equation. It is shown that the suggested method provides a powerful mathematical instrument for solving nonlinear equations in mathematical physics and engineering.     

Theoretical study of hydrogen adsorption in Ti-decorated capped carbon nanotube

We present ab initio study using dispersion-corrected density functional theory calculations to investigate the hydrogen interaction with Ti-coated, one end closed, single-walled carbon nanotube (SWCNT). Our results demonstrate that a single Ti atom binds up to five hydrogen molecules on SWCNT cap top, whereas adsorption of four hydrogen molecules is energetically more favourable. The analyses from adsorption energy profile, highest occupied molecular orbital–lowest unoccupied molecular orbital gap and Mulliken charge distribution show contrast in first hydrogen molecule adsorption compared with the rest of four configurations. This is clearly due to the strongly different bonding nature of first hydrogen adsorption among others, between hydrogen molecules and Ti-coated SWCNT. These results not only support our understanding of adsorption nature of hydrogen in Ti-coated SWCNTs but also suggest new directions for smart storage techniques.     

L-proline/cholesterol and diosgenin based thiourea cooperative system for the direct asymmetric aldol reaction in the presence of water

A series of cholesterol and based hydrophobic urea and thiourea compounds were synthesized and successfully used as a cocatalyst for L-proline catalyzed aldol reactions in the presence of water. The anticonfigured products were obtained with good yields (up to 94%), high diastereoselectivities (up to 95:5), and high enantiomeric excesses (up to 93% ee ). The successful results for catalytic efficiency of L-proline in the presence of water reveal the importance of the hydrophobic nature of cholesterol and diosgenin parts of thiourea on the reactivity and selectivity in the presence of water.     

Developing column material for the separation of serum amyloid P and C reactive protein from biological sources

In this study, we have investigated the isolation of serum amyloid P (SAP) and C‐reactive protein (CRP) from rainbow trout. It has recently been found that SAP is deposited in atherosclerotic lesions or neurofibrillary tangles, which are related to aging process and Alzheimer's disease. Given the importance of CRP, the CRP level in blood is becoming recognized as a potential means of monitoring cardiovascular risk. These two proteins, members of the pentraxin family of oligomeric serum proteins, were isolated from rainbow trout using N‐methacryloyl‐phosphoserine (MA‐pSer) immobilized poly (2‐hydroxy ethylmethacrylate) (PHEMA) cryogels as a column material in a fast protein liquid chromatography system. The separation process was verified in two steps. First, SAP and CRP proteins were isolated together from serum sample of rainbow trout using MA‐pSer/PHEMA cryogel columns. Second, SAP protein was separated chromatographically from CRP protein using the Ca²⁺ ion immobilized PHEMA cryogel column. According to the data, a new and effective technique has been developed for the isolation of SAP and CRP proteins from a biological source, rainbow trout. Finally, purified SAP and CRP were loaded using sodium dodecyl sulfate–polyacrylamide gel and western blot analysis to investigate the purity of chromatographically isolated SAP and CRP compared with commertial SAP and CRP. Copyright © 2014 John Wiley & Sons, Ltd.     

Developing teachers' models for assessing students' competence in mathematical modelling through lesson study

Applications and modelling have gained a prominent role in mathematics education reform documents and curricula. Thus, there is a growing need for studies focusing on the effective use of mathematical modelling in classrooms. Assessment is an integral part of using modelling activities in classrooms, since it allows teachers to identify and manage problems that arise in various stages of the modelling process. However, teachers’ difficulties in assessing student modelling work are a challenge to be considered when implementing modelling in the classroom. Thus, the purpose of this study was to investigate how teachers’ knowledge on generating assessment criteria for assessing student competence in mathematical modelling evolved through a professional development programme, which is based on a lesson study approach and modelling perspective. The data was collected with four teachers from two public high schools over a five-month period. The professional development programme included a cyclical process, with each cycle consisting of an introductory meeting, the implementation of a model-eliciting activity with students, and a follow-up meeting. The results showed that the professional development programme contributed to teachers’ knowledge for generating assessment criteria on the products, and the observable actions that affect the modelling cycle.     

Conservation laws and double reduction of (2+1) dimensional Calogero–Bogoyavlenskii–Schiff equation

In this paper, we obtain conservation laws of (2+1) dimensional Calogero–Bogoyavlenskii–Schiff equation by non‐local conservation theorem method. Besides, exact solutions are obtained by the aid of the symmetries associated with conservation laws. Double reduction is used to obtain these exact solution of Calogero–Bogoyavlenskii–Schiff equation. Copyright © 2016 John Wiley & Sons, Ltd.