Twelve compounds containing a sulphur- or oxygen-based heterocyclic core, 1,3- oxazole or 1,3-thiazole ring with hydroxy, methoxy and methyl terminal substituent, were synthesized and characterized. The molecular structures of these compounds were performed by elemental analysis and different spectroscopic tequniques. The liquid crystalline behaviors were studied by using hot-stage optical polarizing microscopy and differential scanning calorimetry. All compounds of 1,4- disubstituted benzene core with oxazole ring display liquid crystalline smectic A (SmA) mesophase. The compounds of 1,3- and 1,4-disubstituted benzene core with thiazole ring exhibit exclusively enantiotropic nematic liquid crystal phases.

Many experiments were achieved to determine the allelopathic potential of the plant Myrtle parts in which it may affects other plants, like: volatile substances which released from the Myrtle leaves , and its effect examined on the germination (GE) and growth (GR) of the selected crops ; Chickpea ( C ) , Wheat(W) , and Lentil (L)., the aqueous extract of the leaf and the root of the plant examined to test its effect on the (GE) and (GR) of the selected crops ; (C) , (W) , and (L)., also plant residue of (M) and its effect tested on the (GE) and (GR) of the selected crops ; ( C ) , (W) , and (L) . Experiments proceeded on Spring 2007 in the greenhouse conditions , and main results which found were that; the effect of the volatile s

The synthesis and structural characterization of new dithiocarbamate (DTC) ligand and some of its dinuclear transition metal complexes are described. The free dithiocarbamate ligand was prepared through several synthetic routes, including Schiff-base formation. The reaction of 2-aminopropane with terephthaldehyde leads to the formation of Schiff^_base which is reduced by methanolic NaBH₄ to the corresponding secondary diamine. Diamine( N,N'^_ (1,4 phenylenebis (methylene)) bis(propan-2 amine))  reacts with (CS₂) in a basic solution of (KOH) to provide the corresponding bis(dithiocarbamate) free^_ligand, which undergoes complexation with the appropriate metal   (II) chlori

Objective: Schiff’s and Mannich bases of isatins are an important group of heterocyclic compounds which are of great importance in medicinal chemistry as antimicrobial agents. In the vision of these facts, new bis-Schiff bases and Mannich bases of isatins were synthesized. Methods: Three different bis-Schiff bases (3a-c) have been synthesized by reacting isatin, 5-fluoroisatin and 5-methoxy isatin with thiophene-2- carboxaldehyde using hydrazine hydrate to link between the carbonyl compounds, and then these bis- Schiff bases were condensed with two different secondary amines (piperidine and morpholine) separately, and formaldehyde to form the Mannich bases (4a-c and 5a-f), respectively. Results: The structures of the newly synthesized com

Let f and g be a self – maps of a rational exterior space . A natural number m is called a minimal coincidence period of maps f and g if f^m and g^m have a coincidence point which is not coincidence by any earlier iterates. This paper presents a complete description of the set of algebraic coincidence periods for self - maps of a rational exterior space which has rank 2 .

Background: The healing period for bone–implant contact takes 3–6 months or even longer. Application of Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) to implant surfaces has been of great interest on osseointegration due to its osteoinductive potential. The objective of this study was to evaluate the effect of ErhBMP-2 on implant stability. Materials and methods: A total of 48 dental implants were inserted in 15 patients. Twenty four implants coated with 0.5 mg/ml ErhBMP-2 (study group). The other 24 implants were uncoated (control group). Each patient was received at least two dental implants at the same session. Both groups were followed with repeated implant stability measurements by me

Nanocrystalline micro-mesoporous ZSM/MCM-41 composite was synthesized using alkaline treatment method and two step of crystallization in poly tetraflouroethylene (PTFE) lined autoclave. The synthesized zeolites was characterized by X-Ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), Fourier transport infrared (FTIR), and N₂ adsorption-desorption (BET). It was approved that the best results for alkaline leaching can be got with 1.5M NaOH solution. High surface (BET) area of 630 m²/g with pore volume of 0.55 cm³/g has been got. AFM reports showed a nano-level size for average particle size of 50nm.

    The main focus of research is on the nature of applications in the fields of science and technology, particularly nanotechnology. In this paper, a simple, non-toxic, inexpensive, and environmentally friendly green method was used to synthesize TiO₂ nanoparticles using the extraction of portulacaria afra plant leaves and TiCl₄ as a precursor. The synthesized titanium dioxide nanoparticles were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction patterns, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. The SEM image of TiO₂ nanoparticles showed a few spherical, non-agglomerated particles. The average diameter of the nanoparticles, ac