Thermally stable epoxy polymers from new tetraglycidyl amine-based resin

Journal of Thermal Analysis and Calorimetry - A tetraglycidyl amines-based epoxy resin, namely 4-(2-(4-(bis(oxiran-2-ylmethyl)amino)phenoxy)ethoxy)-N,N-bis(oxiran-2-ylmethyl)benzenamine (TGAE), was...     

A Rose Oxide Synthesis

A four-step synthesis of rose oxide from crotonaldehyde by Grignard reaction, Claisen rearrangement, reduction, and cyclization, is reported.     

New furocarbazole alkaloids from Lonicera quinquelocularis

Two new furocarbazole alkaloids, 3-formyl-6,7-dimethoxy-furo[1,2]carbazole (1) and methyl-6,7-dimethoxy-furo[1,2]carbazole-3-carboxylate (2), along with two known carbazole alkaloids, 3-formyl-2-hydroxy-7-methoxycarbazole (3) and methyl 2,7-dimethoxycarbazole-3-carboxylate (4) were isolated from the ethyl acetate soluble fraction of Lonicera quinquelocularis. Their structures were established on the basis of spectroscopic analysis.     

Ultra-long multicolor belts and unique morphologies of tin-doped zinc oxide nanostructures

We demonstrate the synthesis, characterization and application of pure and tin (Sn) doped zinc oxide (ZnO) nanostructures with unique optical properties. Pencil-shaped nanorods were synthesized using a mixture of pure ZnO and carbon as starting material. The growth mechanism of these nanorods is discussed in detail. Sn-doped ultra-long belt-shape ZnO structures show many different colors in a single belt under fluorescent light in an optical microscope. These different colors are attributed to the presence of different defects in the ZnO lattice. X-ray diffraction and UV–VIS spectroscopy results are in good agreement with each other. A major application for these belts is likely to be in a single-particle sensor. A single belt based UV sensor is also fabricated and the results suggest that these photoconducting belts can serve as highly sensitive UV-light detectors.     

Modeling Translation in Protein Synthesis with TASEP: A Tutorial and Recent Developments

The phenomenon of protein synthesis has been modeled in terms of totally asymmetric simple exclusion processes (TASEP) since 1968. In this article, we provide a tutorial of the biological and mathematical aspects of this approach. We also summarize several new results, concerned with limited resources in the cell and simple estimates for the current (protein production rate) of a TASEP with inhomogeneous hopping rates, reflecting the characteristics of real genes.     

Spectral tuning by selective enhancement of electric and magnetic dipole emission

We demonstrate that magnetic dipole transitions provide an additional degree of freedom for engineering emission spectra. Without the need for a high-quality optical cavity, we show how a simple gold mirror can strongly tune the emission of trivalent europium. We exploit the differing field symmetries of electric and magnetic dipoles to selectively direct the majority of emission through each of three major transitions (centered at 590, 620, and 700 nm), and present a model that accurately predicts this tuning from the local electric and magnetic density of optical states.     

Simultaneous extraction of trace amounts of cobalt, nickel and copper ions using magnetic iron oxide nanoparticles without chelating agent

The present study investigates the application of Fe₃O₄ nanoparticles as an adsorbent for solid phase extraction and their subsequent determination of trace amounts of cobalt, nickel and copper from environmental water samples using flame atomic absorption spectrometry. The analyte ions were adsorbed on magnetic nanoparticles in the pH range of 10–12 and then, Fe₃O₄ nanoparticles were easily separated from the aqueous solution by applying an external magnetic field and decantation. Hence, no filtration or centrifugation was needed. After extraction and collection of magnetic nanoparticles, the analyte ions were desorbed using 1.0 M HNO₃. Several factors that may affect the preconcentration and extraction process, including pH, type and volume of eluent, sample volume, salt effect and matrix effect were optimized. Under the optimized conditions, linearity was maintained from 0.005–3.0 μg/mL for cobalt and nickel and 0.001 to 1.25 μg/mL for copper in the initial solution. The detection limits of this method for cobalt, nickel and copper ions were 0.9, 0.7 and 0.3 ng/mL, respectively. Finally, the method was successfully applied to the extraction and determination of the analyte ions in natural waters and reference plant samples.     

The Study of Ascorbate Peroxidase,Catalase and Peroxidase During In Vitro Regeneration of Argyrolobium roseum

Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L^?1 1-nephthalene acetic acid (NAA) and 0.5 mg L^?1 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO₃ and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis.     

Magneto-thermo analysis of oscillatory flow around a non-conducting horizontal circular cylinder

Journal of Thermal Analysis and Calorimetry - The present study is based on oscillatory mixed-convection flow of electrically conducting fluid around a non-conducting horizontal circular cylinder....