Measurement of L&agr; and Lß X-ray fluorescence cross sections in Er, Ta, W and Au by 16.896–59.543 keV photons

La and Lb X-ray fluorescence cross sections in Er, Ta, W and Au at excitation energies of 16.896, 22.581, 25.770, 32.890, 38.184, 43.949, 50.214 and 59.5 keV were investigated. Measurements were made using a low energy Si(Li) detector coupled to a model 4096 computerized multi-channel analyser. The experimental results were compared with the theoretically calculated values of L X-rays fluorescence cross sections and other experimental results. Good agreement was observed between experimental and theoretical values.     

Quantum calculations of vibrational harmonic energy transfer in collinear collisions of X2Y2 + A and X2Y2 + A2

Quantum calculations of translational-vibrational energy transfer in atom-four-atom and diatom-four-atom collinear collisions are reported. Energy transfer shows a strong dependence on the reduced mass of the collision system and on whether the incoming particle is an atom or a molecule. Atom-molecule collisions are more efficient for energy transfer purposes.     

Thermosensitive mucoadhesive gel formulation loaded with 5-Fu: cyclodextrin complex for HPV-induced cervical cancer

Human Papilloma Virus (HPV) infections are the major cause of cervical cancers. To achieve a better therapeutic efficacy and patient compliance in the treatment for HPV-induced cervical cancers, anticancer agent 5-fluorouracil has been formulated in a vaginal gel using the thermosensitive polymer Pluronic^® F127 together with alternative mucoadhesive polymers e.g., hyaluronic acid, Carbopol 934 and hydroxypropylmethylcellulose. To increase its aqueous solubility and to achieve the complete release of 5-FU from the gel, the drug was incorporated as its inclusion complex with 1:1 molar ratio with either β-cyclodextrin or hydroxypropyl-β-cyclodextrin. Following the characterization of drug:CD complexes, thermosensitive gel formulations containing different mucoadhesive polymers and the drug in free or complexed form were characterized in vitro by determining the gelation temperature and the rheological behavior of different formulations along with the in vitro release profiles of these formulations in pH 5.5 citrate buffer. It was observed that complexation with cyclodextrin accelerated the release of 5-FU with the exception of formulation containing Carbopol 934 as mucoadhesive polymer. As far as rheological properties are concerned, favorable thermosensitive in situ gelling properties were obtained with formulations containing HPMC as mucoadhesive polymer. Complete release of 5-FU from gels were obtained with both complexes of β-CD and HP-β-CD and cytotoxicity studies against HeLa human cervical carcinoma cells demonstrated that 1% 5-FU:CD complexes were equally effective as 1% free 5-FU indicating better therapeutic efficacy with lower dose.     

Spectroscopic Characterization and Biological Activity of Salicylaldehyde Thiazolyl Hydrazone Ligands and their Metal Complexes

Two novel bidentate Schiff base ligands, 2-(2-hydroxy-3,5-dichloro/diboromo) benzaldehyde-[4-(3-methyl-3-mesitylcyclobutyl)-1,3-thiazol-2-yl]hydrazone, L¹H, L²H and their transition metal complexes are reported. The new ligands and their complexes have been characterized by elemental analyses, Λ_M, infrared, u.v.–vis, ¹H- and ¹³C-n.m.r. spectroscopy, and magnetic susceptibility measurements. The thermal properties of all complexes have been investigated by TG technique. The complexes contain two monoanionic, bidentate NO ligands. It was found that all the complexes are mononuclear. Antimicrobial activities of the ligands and their complexes have been tested against five different microorganisms, and some of the complexes were found to be active against some of the microorganisms studied.     

Natural Abundance 17O-NMR. Study of Some Macrocyclic Complexes with Alkali Metal Cations

Complexation between crown ethers 12C4, 15C5, 18C6 and cryptand 222, and alkali cations Li⁺, Na⁺, K⁺ in various solvents were studied by ¹⁷O-NMR. spectroscopy. Small diamagnetic shifts arising from the cation electric field are observed. They increase according to the sequence K⁺ < Na⁺ < Li⁺. ¹⁷O-linewidth are discussed and compared to the ¹³C relaxation times. Linewidth modification results mainly from modifications of the effective correlation time. In general, for crown ethers, considerable line broadening occurs when the cation fits well into the cavity but line narrowing occurs when the cation is much smaller than the cavity.     

Binuclear and mononuclear cobalt(II), nickel(II) and copper(II) complexes of 4,4′-bis(alkylaminoisonitrosoacetyl)diphenyl-methane derivatives

4,4-Bis(chloroacetyl)diphenylmethane has been prepared from ClCH₂COCl and Ph₂CH₂. 4,4-Methylenebis(phenylglyoxylohydroximoyl chloride has also been obtained. Four new substituted 4,4-bis(alkylaminoisonitrosoacetyl)diphenylmethanes (ligands) have been prepared from 4,4-methylenebis(phenylglyoxylohydroximoyl chloride) and the corresponding amines. The Ni^II, Cu^II and Co^II complexes of these ligands were prepared and their structures were identified using AAS, i.r., ¹H-n.m.r. spectral data, elemental analyses and magnetic susceptibility measurements.     

Selective LC Determination of Cabergoline in the Bulk Drug and in Tablets: In Vitro Dissolution Studies

Cabergoline (CAB) is an ergot alkaloid derivative with dopamine agonist activity. A novel, simple, and rapid stability-indicating high-performance liquid chromatographic (HPLC) method for assay of CAB in tablets has been developed and validated. Chromatography was performed on a 4.6 mm i.d. × 250 mm, 5 μm particle, cyano column with acetonitrile–10 mM phosphoric acid, 35:65 (v/v), containing 0.04% triethylamine, as mobile phase, at a flow rate of 1.0 mL min^?1, and UV detection at 280 nm. Response was a linear function of concentration in the range 0.1–4 μg mL^?1 (r ² = 0.9999). The recovery of the method was good (99.45%) and RSD values for intra-day and inter-day precision were 0.24–0.88% and 0.66–1.19%, respectively. The method can be used for quality-control assay of CAB in tablets, for stability studies, and for in vitro dissolution studies.     

Metal-Containing Phthalocyanines Substituted with One Branched Bulky Moiety and Six Alkylthio Groups

Summary.  Unsymmetrically substituted metal-phthalocyanines composed of three hexylthio groups and one 1-chloro-3,4-dicyano-6-[2-(2-pyridylmethylamino)phenylthio]benzene moiety was prepared by cyclization of the reactants in the presence of the anhydrous metal salts Zn(CH₃COO)₂, NiCl₂, and CoCl₂. The new unsymmetric phthalocyanines are very soluble in common organic solvents. The compounds were characterised by their elemental analyses, IR, ¹H NMR, MS and UV/Vis spectra. Corresponding author. E-mail: bayir@itu.edu.tr Received November 27, 2002; accepted (revised) December 2, 2002 Published online May 2, 2003     

A novel (E,E)-dioxime and its mono-, di- and trinuclear complexes bearing tetradentate octyl sulfanyl phenylamino substituents. Synthesis,characterization and electrochemical properties of its transition metal complexes

A new vic-dioxime, 13,14-bis-(hydroxyimino)-9,12,15,18-diazadithiaoctacosane, has been synthesized from 2-octylsulfanylaminobenzene and (E,E)-dichloroglyoxime. Mononuclear transition metal complexes of Ni^II, Cu^II, Co^II and Fe^II have been prepared and were found to have a metal–ligand ratio of 1:2. The synthesis of di- and trinuclear complexes was achieved with U^IVO₂ and Cu^II depending on the stoichiometry of the reactants. The complexes were characterized by elemental analysis, ¹H-n.m.r., u.v.–vis, i.r., f.a.b.-m.s. and by cyclic voltammetry.     

An empirical many-body potential energy function constructed from pair-interactions

A new empirical potential energy function (PEF) is proposed, which is formed from pair-interactions only, and containes the many-body contributions. The PEF satisfies bulk cohesive energy and bulk stability condition. The PEF is parameterized for copper, silver, and gold elements in fcc crystal structure. The elastic constantsC ₁₁ andC ₁₂ and the bulk modulus of the elements are calculated, and the structural stability and energetics of microclusters containing 3 to 7 atoms of the same elements are investigated.