Solid complexes of iron(II) and iron(III) with rutin

Solid complex compounds of Fe(II) and Fe(III) ions with rutin were obtained. On the basis of the elementary analysis and thermogravimetric investigation, the following composition of the compounds was determined: (1) FeOH(C₂₇H₂₉O₁₆)·5H₂O, (2) Fe₂OH(C₂₇H₂₇O₁₆)·9H₂O, (3) Fe(OH)₂(C₂₇H₂₉O₁₆)·8H₂O, (4) [Fe₆(OH)₂(4H₂O)(C₁₅H₇O₁₂)SO₄]·10H₂O. The coordination site in a rutin molecule was established on the basis of spectroscopic data (UV–Vis and IR). It was supposed that rutin was bound to the iron ions via 4C=O and 5C—oxygen in the case of (1) and (3). Groups 5C–OH and 4C=O as well as 3′C–OH and 4′C–OH of the ligand participate in binding metals ions in the case of (2). At an excess of iron(III) ions with regard to rutin under the synthesis conditions of (4), a side reaction of ligand oxidation occurs. In this compound, the ligands’ role plays a quinone which arose after rutin oxidation and the substitution of Fe(II) and Fe(III) ions takes place in 4C=O, 5C–OH as well as 4′C–OH, 3′C–OH ligands groups. The magnetic measurements indicated that (1) and (3) are high-spin complexes.     

Mechanical properties and thermal analysis of low‐density polyethylene + polypropylene blends with dialkyl peroxide

Polypropylene + low density polyethylene (PP + LDPE) blends involving 0, 25, 50, 75 and 100 wt% of PP with dialkyl peroxide (DAP) were prepared by melt blending in a single‐screw extruder. The effects of adding dialkyl peroxide on mechanical and thermal properties of PP + LDPE blends have been studied. It was found that at lower concentrations of peroxide (e.g., 0–0.08 wt% of dialkyl peroxide) LDPE component is cross‐linked and Polypropylene (PP) is degraded in all compositions of PP + LDPE blends. Mechanical properties (Tensile strength at break, at yield and elongation at break), Melt flow index (MFI), hardness, Scanning Electron Microscope (SEM) and thermal analyses (DSC) of these blends were examined. Because of serious degradation or cross‐linking the mechanical properties and the crystallinty (%) of those products were decreased as a result of increasing peroxide content. Copyright © 2009 John Wiley & Sons, Ltd.     

The influence of CaCO3 filler component on thermal decomposition process of PP/LDPE/DAP ternary blend

Polypropylene‐low density polyethylene (PP‐LDPE) blends involving PP‐LDPE (90/10 wt%.) with (0.06 wt%) dialkyl peroxide (DAP) and different amounts (5, 10, 20 wt%) of calcium carbonate (CaCO₃) were prepared by melt‐blending with a single‐screw extruder. The effect of addition of CaCO₃ on thermal decomposition process and kinetic parameters, such as activation energy and pre‐exponential factor of PP‐LDPE blend with DAP matrix, was studied. The kinetics of the thermal degradation of composites was investigated by thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. TG curves showed that the thermal decomposition of composites occurred in one weight‐loss stage. The apparent activation energies of thermal decomposition for composites, as determined by the Tang method (TM), the Kissinger–Akahira–Sunose method (KAS), the Flynn–Wall–Ozawa method (FWO), and the Coats–Redfern (CR) method were 156.6, 156.0, 159.8, and 167.7 kJ.mol^?1 for the thermal decomposition of composite with 5 wt% CaCO₃, 191.5, 190.8, 193.1, and 196.8 kJ.mol^?1 for the thermal decomposition of composite with 10 wt% CaCO₃, and 206.3, 206.1, 207.5, and 203.8 kJ mol^?1 for the thermal decomposition of composite with 20 wt% CaCO₃, respectively. The most likely decomposition process for weight‐loss stages of composites with CaCO₃ content 5 and 10 wt% was an A_n sigmoidal type. However, the most likely decomposition process for composite with CaCO₃ content 20 wt% was an R_n contracted geometry shape type in terms of the CR and master plots results. It was also found that the thermal stability, activation energy, and thermal decomposition process were changed with the increase in the CaCO₃ filler weight in composite structure. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and in vitro evaluation of N-(Bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine as a cholinesterase inhibitor with regard to Alzheimer's disease treatment

A new tacrine based cholinesterase inhibitor, N-(bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine (1), was designed and synthesized to interact with specific regions of human acetylcholinesterase and human butyrylcholinesterase. Its inhibitory ability towards cholinesterases was determined and compared to tacrine (THA) and 9-amino-7-methoxy-1,2,3,4-tetrahydroacridine (7-MEOTA). The assessment of IC50 values revealed 1 as a weak inhibitor of both tested enzymes.     

Reactive oxygen species enhance differentiation of human embryonic stem cells into mesendodermal lineage

Recently, reactive oxygen species (ROS) have been studied as a regulator of differentiation into specific cell types in embryonic stem cells (ESCs). However, ROS role in human ESCs (hESCs) is unknown because mouse ESCs have been used mainly for most studies. Herein we suggest that ROS generation may play a critical role in differentiation of hESCs; ROS enhances differentiation of hESCs into bi-potent mesendodermal cell lineage via ROS-involved signaling pathways. In ROS-inducing conditions, expression of pluripotency markers (Oct4, Tra 1-60, Nanog, and Sox2) of hESCs was decreased, while expression of mesodermal and endodermal markers was increased. Moreover, these differentiation events of hESCs in ROS-inducing conditions were decreased by free radical scavenger treatment. hESC-derived embryoid bodies (EBs) also showed similar differentiation patterns by ROS induction. In ROS-related signaling pathway, some of the MAPKs family members in hESCs were also affected by ROS induction. p38 MAPK and AKT (protein kinases B, PKB) were inactivated significantly by buthionine sulfoximine (BSO) treatment. JNK and ERK phosphorylation levels were increased at early time of BSO treatment but not at late time point. Moreover, MAPKs family-specific inhibitors could prevent the mesendodermal differentiation of hESCs by ROS induction. Our results demonstrate that stemness and differentiation of hESCs can be regulated by environmental factors such as ROS.     

Defects in Ce-doped LuAG and YAG scintillation layers grown by liquid phase epitaxy

The single crystalline Lu₃Al₅O₁₂ (LuAG) and Y₃Al₅O₁₂ (YAG) garnet layers doped by Ce³⁺ ions were grown by the liquid phase epitaxy from the flux. The effect of the flux composition, growth conditions, and substrate polishing on the layer morphology, creation of defects, and on optical and emission properties of layers was studied. The defects typical of the epitaxial growth are discussed.     

Diffuse reflection of ultracold neutrons from low-roughness surfaces

We report a measurement of the reflection of ultracold neutrons from flat, large-area plates of different Fermi potential materials with low surface roughness. The results were used to test two diffuse reflection models, the well-known Lambert model and the micro-roughness model which is based on wave scattering. The Lambert model fails to reproduce the diffuse reflection data. The surface roughness b and correlation length w , obtained by fitting the micro-roughness model to the data are in the range 1 $ \le$ b $ \le$ 3 nm and 10 $ \le$ w $ \le$ 120 nm, in qualitative agreement with independent measurements using atomic force microscopy.     

Photofunctional Polyurethane Nanofabrics Doped by Zinc Tetraphenylporphyrin and Zinc Phthalocyanine Photosensitizers

Polymeric polyurethane nanofabrics doped by zinc tetraphenylporphyrin (ZnTPP) and/or zinc phthalocyanine (ZnPc) photosensitizers were prepared by the electrospinning method and characterized by microscopic methods, steady-state and time-resolved fluorescence, and absorption spectroscopy. Nanofabrics doped by both ZnTPP and ZnPc efficiently harvest visible light to generate triplet states and singlet oxygen O₂(¹Δ_g) with a lifetime of about 15 μs in air atmosphere. The energy transfer between the excited singlet states of ZnTPP and ground states of ZnPc is described in details. All nanofabrics have bactericidal surfaces and photooxidize inorganic and organic substrates. ZnTPP and ZnPc in the polyurethane nanofabrics are less photostable than incorporated free-base tetraphenylporphyrin (TPP).     

Refractive index variation of amorphous Ta2O5 film fabricated by ion beam sputtering with RF bias power

Ta₂O₅ film was fabricated by ion beam sputtering with RF bias applied to the substrate. The refractive index in the visible range of the film can be controlled to vary linearly with the RF bias power while low absorption is maintained.     

Additive cyclic codes over finite commutative chain rings

Additive cyclic codes over Galois rings were investigated in Cao et al. (2015). In this paper, we investigate the same problem but over a more general ring family, finite commutative chain rings. When we focus on non-Galois finite commutative chain rings, we observe two different kinds of additivity. One of them is a natural generalization of the study in Cao et al. (2015), whereas the other one has some unusual properties especially while constructing dual codes. We interpret the reasons of such properties and illustrate our results giving concrete examples.