A manganese oxide with phenol groups as a promising structural model for water oxidizing complex in Photosystem II: a 'golden fish'

We describe here the ability of manganese oxide monosheets to aggregate to form layered structures with 4-aminophenol molecules. These aggregated monosheets could be considered as the first step to synthesize a self-assembled layered hybrid of phenol-manganese ions with phenol and manganese(III) and (IV) as exists in the water oxidizing complex of Photosystem II.     

Optical-controlled domain wall resistance in magnetic nanojunctions

Domain walls in ferromagnetic metals are known to be a source of resistance. In the present work resistance of a domain wall in a ferromagnetic nanojunction is investigated using the semiclassical approach. The analysis is based on the Boltzmann transport equation, within the relaxation time approximation. The one-dimensional Néel-type magnetic domain wall is considered and the effect of the electron-photon interaction on the resistance is studied. The results indicate that polarization and wavelength of the photon play a significant role in the magnetoresistance. The resistance of the nanojunction decreases as the wavelength of the photon increases. It is also shown that the domain wall resistance decreases by increasing the Fermi energy.     

Two-photon reduction: a cost-effective method for fabrication of functional metallic nanostructures

Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience. The key to realizing functional plasmonic resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography (EBL) or by focused ion beam (FIB) milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing (DLW) technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostructures. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.     

Synthesis of new di‐ and tetraazadibenzosulfoxide macrocycolic compounds

Novel macrocyclic di and tetraamide compounds have been synthesized by the reaction of 2‐2′‐sulfoxide‐bis‐(4‐methyl phenoxy) aceticester or aceticacid chloride) (obtained from corresponding bisphenol) with appropriate diamines. Also the results of the presence of base as template are discussed and compared.     

Green synthesis of cerium oxide nanoparticle using Origanum majorana L. leaf extract,its characterization and biological activities

Cerium oxide nanoparticle (CeO-NP) was synthesized using Origanum majorana L. leaf extract and characterized using particle size analyzer, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The antioxidant properties and cytotoxic effects of CeO-NP in human breast carcinoma cells (MDA-MB-231 cell line) and human umbilical vein endothelial cells (HUVEC) as normal cells were evaluated. To determine the probable molecular mechanism of action of CeO-NP on cellular redox and anti-inflammatory potential, the expressions of antioxidant-related genes catalase (CAT), superoxide dismutase (SOD) in HUVEC cell line were also analyzed. The results indicated that spherically shaped nanoparticles with a size of 10–70 nm bound to functional phenolic and flavonoids from O. majorana L. leaf extract. The green synthesized CeO-NP showed antioxidant activity by free radical scavenging activity against DPPH and ABTS free radicals. The antioxidant activity was significantly (p < 0.001) lower than that of Butylated hydroxyanisole (BHA) as a reference antioxidant. The obtained results elucidated that CeO-NP possessed cytotoxicity. The cytotoxic effects of CeO-NP were higher against MDA-MB-231 cancer cells compared to HUVEC normal cells. In addition, this NP was capable to enhance the expression of CAT and SOD as main antioxidant-related genes. Consequently, the higher cytotoxic effects of CeO-NP against breast cancer compared to normal cells indicated the potential use of this NP as anti-cancer agent. However, more research on its cytotoxicity against other cancer cells and mechanisms in which this NP exert its anti-cancer properties should be performed.     

Phase equilibria of binary and ternary polymer solutions using modified UNIQUAC-based local composition model

Journal of Thermal Analysis and Calorimetry - In the present research, a modification on UNIQUAC activity coefficient model was done based on the local composition concept. The model was applied...     

Novel Cyclometalated Fe(II) Complex with NCN Pincer and BODIPY‐Appended 4'‐Ethynyl‐2,2':6',2”‐terpyridine as Mitochondria‐Targeted Photodynamic Anticancer Agents

BODIPY (boron dipyrromethene) derivatives and iron complexes are two types of functional compounds that have found wide applications in the fields of biology and medicine. The new class of cyclometalated Fe(II) complex with NCN pincer and meso‐phenyl‐4'‐ethynyl‐2,2':6',2”‐terpyridine BODIPY ligands of formula [Fe(L)(tpy‐BODIPY)] , 1, in which HL:5‐methoxy‐1,3‐bis (1‐methyl‐1H‐benzo[d]imidazol‐2‐yl)benzene, tpy‐BODIPY: 8‐(4‐phenyl‐4'‐ethynyl‐2,2':6',2”‐terpyridine) BODIPY, has been synthesized and studied as mitochondria‐targeted photodynamic therapy (PDT). Complex 1 showed photocytotoxicity in HeLa cells at 500 nm with low dark toxicity. The phototoxicity of complex 1 on the nontumorigenic MRC‐5 cell line showed the same trend observed for HeLa cells, that is moderately photocytotoxic against the nontumorigenic MRC‐5 cell line (IC₅₀ = 36.21 μM). Moreover, complex 1 selectively localizes into mitochondria of the HeLa cells. The photophysical properties, cellular uptake, reactive oxygen species (ROS) generation, and cellular apoptosis of complex 1 have also been studied.Overall, the new Fe(II) complex with BODIPY moiety is significantly photocytotoxic in HeLa cells when irradiated with visible light of 500 nm giving as mitochondria targeting. Therefore, we present cyclometalated Fe(II) pincer complex induced mitochondria‐targeted PDT involving the BODIPY moiety that develops persuasively designed photoactivatable Fe(II) complexes.     

A High Sensitive TNT Sensor Based on Electrochemically Reduced Graphene Oxide‐Poly(amidoamine) Modified Electrode

In this paper, the electrochemically reduced graphene oxide‐poly(amidoamine) hybrid (ErGO‐PAMAM) have been used for fabrication of TNT electrochemical sensor. The prepared modified electrode is characterized with X‐ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FT‐IR), electrochemical impedance spectroscopy (EIS), energy‐dispersive X‐ray (EDX) spectroscopy, scanning electron microscopy (SEM) and atomic force microscope (AFM). Based on obtained results, it is can be seen that the ErGO‐PAMAM/GCE has high response to TNT than the other graphene based modified electrodes. The resulting electrochemical sensor exhibited good response to TNT with linear range from 0.05 to 1.2 ppm with a low detection limit of 0.0015 ppm.     

Electrocatalytic Determination of Traces of Hydrazine by a Glassy Carbon Electrode Modified with Palladium‐Gold Nanoparticles

A glassy carbon electrode modified with palladium/gold nanoparticles was successfully prepared by an electrodeposition process. It efficiently oxidizes hydrazine at a low overpotential of ?0.26 V versus SCE. The Pd‐AuNPs with an average size of 50–80 nm are uniformly dispersed at the GCE. The Pd‐AuNPs/GCE was used for determination of hydrazine in phosphate buffer solution of pH 7.0. The amperometric current response of the electrode was increased linearly over a hydrazine concentration of 0.1–500 µM with a limit of detection of 0.07 µM .The prepared hydrazine sensor exhibited high sensitivity, good selectivity reproducibility and long term stability.