Essential oil composition of five collections of Achillea biebersteinii from central Turkey and their antifungal and insecticidal activity

The composition of the essential oils hydrodistilled from the aerial parts of five Achillea biebersteinii Afan samples, collected in central Turkey from Konya, Isparta and Ankara, were analyzed both by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Eighty-four components were identified, representing 87 to 99% of the total oil composition. The identified major components were 1,8-cineole (9-37%), camphor (16-30%) and p-cymene (1-27%). Two samples differed in piperitone (11%) and ascaridol (4%) content. The five A. biebersteinii essential oils were subsequently evaluated for their antifungal activity against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides using the direct overlay bioautography assay. The essential oils showed no antifungal activity at 80 and 160 microg/spot. In addition, A. biebersteinii oils and their major compounds were subsequently investigated against Aedes aegypti first instar larvae in a high throughput bioassay. Among the oils, only one sample from Ankara showed a notable larvacidal effect on Ae. aegypti larvae. The major compounds, 1,8-cineole, camphor and p-cymene, exhibited low mosquito larval activity, and thus the minor compounds are probably responsible for the observed activity against Ae. aegypti larvae. The oils showed weak activity against adult Ae. aegypti.     

Synthesis and characterization of anhydrous conducting polyimide/ionic liquid complex membranes via a new route for high‐temperature fuel cells

The paper deals with the synthesis and characterization of a new series of anhydrous conducting acid‐doped complex membranes based on polyimide (PI) and ionic liquid (IL) for high‐temperature fuel cells via a new route. For this purpose, three imidazolium‐based ILs (RIm⁺BF₄^?) with different alkyl chain lengths (R=methyl, ethyl, and butyl) are added into polyamic acid (PAA) intermediate prepared from the reaction of benzophenonetetracarboxylic dianhydride and diaminodiphenylsulfone in different –COOH/imidazolium molar ratios (n = 0.5, 1, and 2). Then, the thermally imidized complex membrane was doped with H₂SO₄. The conductivities of acid‐doped PI/IL complex membranes prepared by taking n of 1 are found to be in the range of 10^?4?10^?5 S cm^?1 at 180°C, whereas the acid‐free PI/IL complex membranes show the conductivity at around 10^?9?10^?10 S cm^?1. Thermogravimetric analysis results reveal that the acid‐doped PI/IL complex membranes are thermally stable up to 250°C. Dynamic mechanical analysis results of the acid‐doped ionically interacted complex membrane show that the mechanical strengths of the PI/IL complex membranes including 1‐methyl imidazolium tetrafluoroborate (MeIm‐BF₄) and 1‐ethyl 3‐methyl imidazolium tetrafluoroborate (EtIm‐BF₄) are comparable with those of pristine PI until 200°C. Furthermore, it can be clearly emphasized that the ionic interaction between carboxylic acid groups of PAA's and IL's cations offers a positive role in long‐term conductivity stability by preventing the IL migration at high temperatures. On the other hand, preliminary methanol permeability tests of the acid‐doped membranes show that they can also be considered as an alternative for direct methanol fuel cells. Copyright © 2011 John Wiley & Sons, Ltd.     

Palladium(II) complexes with aminomethylphosphine ligands as catalysts for the heck reaction

New, aminomethyldiphosphine (P C N) ligands, ((C₆H₅)₂PCH₂)₂NR (R =  C₆H₃ (CH₃)(OH) ( 1a ),  C₆H₄OC₆H₅( 1b ),  C₆H₄SC₆H₅) ( 1c )) and their Pd(II) complexes have been synthesized and characterized. These complexes were found to be efficient catalysts in the Heck reaction of activated and deactivated aryl halide with a variety of olefins. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:466–471, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21038     

Cyclic codes over <Emphasis Type="Italic">R</Emphasis><Subscript><Emphasis Type="Italic">k</Emphasis></Subscript>

Cyclic codes over an infinite family of rings are defined. The general properties of cyclic codes over these rings are studied, in particular nontrivial one-generator cyclic codes are characterized. It is also proved that the binary images of cyclic codes over these rings under the natural Gray map are binary quasi-cyclic codes of index 2 ^k . Further, several optimal or near optimal binary codes are obtained from cyclic codes over R _k via this map.     

Analysis of current–voltage and capacitance–voltage characteristics of perylene-monoimide/n-Si Schottky contacts

The electrical and interface state properties of Au/perylene-monoimide (PMI)/n-Si Schottky barrier diode have been investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements at room temperature. A good rectifying behavior was seen from the I–V characteristics. The series resistance (R_s) values were determined from I–V and C–V characteristics and were found to be 160 Ω and 53 Ω, respectively. The barrier height (Φ_b) of Au/PMI/n-Si Schottky diode was found to be 0.694 eV (I–V) and 0.826 eV (C–V). The ideality factor (n) was obtained to be 4.27 from the forward bias I–V characteristics. The energy distribution of interface state density (N_ss) of the PMI-based structure was determined, and the energy values of N_ss were found in the range from E_c ? 0.508 eV to E_c ? 0.569 eV with the exponential growth from midgap toward the bottom of the conduction band. The values of the N_ss without R_s are 2.11 × 10¹² eV^?1 cm^?2 at E_c ? 0.508 eV and 2.00 × 10¹² eV^?1 cm^?2 at E_c ? 0.569 eV. Based on the above results, it is clear that modification of the interfacial potential barrier for metal/n-Si structures has been achieved using a thin interlayer of the perylene-monomide.     

Solution of counter diffusion problem with position dependent diffusion coefficent by using variational methods

Unsteady state counter diffusion problem with position dependent diffusion coefficient can be modeled using Fick’s second law. A mathematical model was constructed and solved to quantitatively describe the dynamic behavior of solute diffusion through non-homogeneous materials where diffusion coefficient is a function of position. The eigenfunction expansion approach was utilized to solve the model. The eigenvalues and eigenfunction of the system were obtained using a variational method. It has been shown that position dependency of the material can be neglected if the thickness of the material is relatively small. Mathematical models were solved for different thicknesses and different diffusion coefficient functions.     

A Combination of Visudyne and a Lipid‐anchored Liposomal Formulation of Benzoporphyrin Derivative Enhances Photodynamic Therapy Efficacy in a 3D Model for Ovarian Cancer

A major objective in developing new treatment approaches for lethal tumors is to reduce toxicity to normal tissues while maintaining therapeutic efficacy. Photodynamic therapy (PDT) provides a mechanistically distinct approach to treat tumors without the systemic toxicity of chemotherapy drugs. PDT involves the light‐based activation of a small molecule, a photosensitizer (PS), to generate reactive molecular species (RMS) that are toxic to target tissue. Depending on the PS localization, various cellular and subcellular components can be targeted, causing selective photodamage. It has been shown that targeted lysosomal photodamage followed by, or simultaneous with, mitochondrial photodamage using two different PS results in a considerable enhancement in PDT efficacy. Here, two liposomal formulations of benzoporphyrin derivative (BPD): (1) Visudyne (clinically approved) and (2) an in‐house formulation entrapping a lipid conjugate of BPD are used in combination with direct PS localization to mitochondria, endoplasmic reticulum and lysosomes, enabling simultaneous photodamage to all three organelles using a single wavelength of light. Building on findings by our group, and others, this study demonstrates, for the first time in a 3D model for ovarian cancer, that BPD‐mediated photodestruction of lysosomes and mitochondria/ER significantly enhances PDT efficacy at lower light doses than treatment with either PS formulation alone.     

Structural,Morphological and Optical Properties of Well-Ordered CdO Nanostructures Synthesized by Easy-Economical Chemical Bath Deposition Technique

In this Study, Cadmium Oxide (CdO) nanostructures were synthesized by using Chemical Bath Deposition Technique. The synthesized process was carried out at room temperature. The structural and optical properties of nanostructures was characterized by XRD, SEM and UV-Vis techniques. As a result, the CdO nanostructures are oriented along (111) plane of cubic crystal structure. The morphology of CdO nanostructures showed interconnected prism-like and cauliflower-type cluster nanostructure. The UV results of this structures with high absorbtion coefficient are observed to be in accordance with the CdO nanoparticles.     

Radiation-stimulated processes of Destruction and polycondensation of coals

The regularities of destructive and polycondensation processes in lignites of the Soma coal field, Turkey, were investigated by the methods of EPR, IR spectroscopy, derivatography and chromatography. It was shown that on lignite irradiation by -rays the character of the processes changes, depending on the absorbed dose and temperature. At room temperature and doses up to 200 kGy irradiation leads to the accumulation of radiation defects, which stimulate destructive reactions. At higher doses, due to the recombination of radiation defects, there is radiation lacing of the organic mass of coals. On the conjugate action of heat and irradiation on coals, destrution processes predominate. The mechanism of radiation effect upon coals is explained within the scope of the conception of self-associated multimer structure of coals.