1-Butyl-2-methylpipyridinium iodide ([BMPPY]I): novel ionic liquid for the synthesis of 6-hydroxy-6-(1H-indol-3-yl)indolo[2,1-b]quinazolin-12(6H)-ones under green solvent-free conditions

Research on Chemical Intermediates - In this article we reported preparation of 1-butyl-2-methylpipyridinium iodide ([BMPPY]I), as a novel ionic liquid (IL) through simple procedure. This newly...     

Hadronic modes in the quark plasma with an internal symmetry

We show that requiring the quark partition function to be color singlet in the SU(3) color gauge group leads to reordering of the thermodynamic potential in terms of the colorless multiquark modes (, qqq, , ) at any given temperature. These color-singlet structures are not bound states in a real sense, rather they are a combination of constituent quarks only. In accord with the “preconfinement” property of QCD, under a suitable confining mechanism, these could evolve into color-singlet hadrons/baryons at low temperatures. At fairly high temperatures, these multiquark color-singlet structures exist in the plasma as hadronic modes, just as in the more familiar low-temperature phase. This suggests that there exists a strong color correlation in the plasma at all temperatures. Received: 25 May 1999 / Published online: 2 November 1999     

Preparation of alkaline polymer catalyst by radiation induced grafting for transesterification of triacetin under neural network optimized conditions

A simple and flexible method was used to develop new alkaline polymer catalyst through radiation induced grafting of glycidylmethacrylate (GMA) onto polyethylene/polypropylene (PE/PP) nonwoven sheet followed by amination reaction and alkalisation. The chemical structure and morphology of catalyst was evaluated by Fourier transform-infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA). The catalyst was examined for the transesterification of triacetin/methanol mixtures in a batch mode and the obtained methyl ester was detected by GC-MS. In order to optimize the reaction parameters towards getting the higher yield, an artificial neural network (ANN) was used to develop a non-linear model correlating the four independent reaction parameters including catalyst dosage, triacetin/methanol molar ratio, reaction time and temperature. The maximum conversion obtained via the simulated annealing (SA) algorithm was 86.2% at the optimal conditions of 5.01 wt% catalyst dosage, triacetin/methanol 1:12 molar ratio, 8 h reaction time and 62.8°C temperature. Upon using these optimal conditions in the experimental reaction, the conversion of as high as 85% was achieved. These results suggest that the simply modified low cost PE/PP fibrous sheet has a potential to catalyze biodiesel production. Moreover, the combined ANN-SA modelling method is highly effective in predicting the conversion of transesterification reaction and optimizing its parameters.     

Novel organometallic nanomagnetic catalyst for multicomponent synthesis of spiroindoline derivatives

A novel, green, reusable polyaniline (PANI)/Fe₃O₄/carbon nanotube (CNT) nanomagnetic catalyst has been prepared, characterized by Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) analysis, and applied for four-component synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives from isatin, hydrazine hydrate or phenylhydrazine, ethyl acetoacetate, and malononitrile or ethyl cyanoacetate in aqueous medium at room temperature. Use of water as safe and environmentally benign solvent, short reaction time, high product yield, easy workup procedure, and easy separation and reusability of the catalyst are noteworthy advantages of this approach.     

Study of Polypyrrole/Graphene Oxide Nanocomposite Structural and Morphological Changes Including Porosity

Polypyrrole/graphene oxide (PPy/GO) nanocomposite films were electrochemically synthesized to study their structural features. For this purpose, pyrrole monomer was exposed to oxidation in an aqueous dilute solution containing definite amounts of GO and a dopant electrolyte. Potentiostatic electropolymerization was carried out and the current-time curves were obtained for each electrodeposition test. Accordingly, a number of appropriate characterization analyses such as mercury porosimetry, TGA, SEM, XRD, Raman and FTIR spectroscopies were performed in order to investigate the composition and structure of the films. In this regard, factors such as incorporation of GO in the polymer matrix, porous layer structure and the thickness of the films were determined. The results showed that GO concentration could influence on both film thickness and its porous structure. Also, it was observed that the main factor controlling the film thickness and morphology is the potential applied.     

The copolymer coating effect on the catalytic activity of magnetic carbon nanotube (CNT-Fe3O4) in the multi-component reactions

Research on Chemical Intermediates - Two new magnetic nanocomposites containing aniline–pyrrole copolymer-coated magnetic carbon nano-tubes (poly(Ani-co-Py)@CNT-Fe3O4) were synthesized and...     

Process equation as a model for the development of cells

The European Physical Journal Special Topics - This paper proposes a behavioral model for cells that shows their different dynamics from a high pluripotent stem cell to any distinct cell fate. The...     

Discovery of Leptulipin,a New Anticancer Protein from theIranian Scorpion,Hemiscorpius lepturus

Cancer is one of the leading causes of mortality in the world. Unfortunately, the present anticancer chemotherapeutics display high cytotoxicity. Accordingly, the discovery of new anticancer agents with lower side effects is highly necessitated. This study aimed to discover an anticancer compound from Hemiscorpius lepturus scorpion venom. Bioactivity-guided chromatography was performed to isolate an active compound against colon and breast cancer cell lines. 2D electrophoresis and MALDI-TOF were performed to identify the molecule. A partial protein sequence was obtained by mass spectrometry, while the full-length was deciphered using a cDNA library of the venom gland by bioinformatics analyses and was designated as leptulipin. The gene was cloned in pET-26b, expressed, and purified. The anticancer effect and mechanism action of leptulipin were evaluated by MTT, apoptosis, and cell cycle assays, as well as by gene expression analysis of apoptosis-related genes. The treated cells displayed inhibition of cell proliferation, altered morphology, DNA fragmentation, and cell cycle arrest. Furthermore, the treated cells showed a decrease in BCL-2 expression and an increase in Bax and Caspase 9 genes. In this study, we discovered a new anticancer protein from H. lepturus scorpion venom. Leptulipin showed significant anticancer activity against breast and colon cancer cell lines.