Widrow-cellular neural network and optoelectronic implementation

A new type of optoelectronic cellular neural network has been developed by providing the capability of coefficients adjusment of cellular neural network (CNN) using Widrow based perceptron learning algorithm. The new supervised cellular neural network is called Widrow-CNN. Despite the unsupervised CNN, the proposed learning algorithm allows to use the Widrow-CNN for various image processing applications easily. Also, the capability of CNN for image processing and feature extraction has been improved using basic joint transform correlation architecture. This hardware application presents high speed processing capability compared to digital applications. The optoelectronic Widrow-CNN has been tested for classic CNN feature extraction problems. It yields the best results even in case of hard feature extraction problems such as diagonal line detection and vertical line determination.     

Photon interaction studies using 241Am γ-rays

We have carried out some photon interaction measurements using 59.54 keV γ-rays from a ²⁴¹Am source. These include γ attenuation studies as well as photoelectric absorption studies in various samples. The attenuation studies have been made using leaf and wood samples, samples like sand, sugar etc., which contain particles of varying sizes as well as pellets and aqueous solutions of rare earth compounds. In the case of the leaf and wood samples, we have used the γ-ray attenuation technique for the determination of the water content in fresh and dried samples. The variation of the attenuation coefficient with particle size has been investigated for sand and sugar samples. The attenuation studies as well as the photoelectric studies in the case of rare earth elements have been carried out on samples containing such elements whose K-absorption edge energies lie below and close to the γ-energy used. Suitable compounds of the rare earth elements have been chosen as mixture absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. A well-shielded scattering geometry was used for the photoelectric measurements. The mixture rule was invoked to extract the values of the mass attenuation coefficients for the elements from those of the corresponding compounds. The results are consistent with theoretical values derived from the XCOM package.     

Synthesis of the possible carcinogenic dihydrodiol and diol epoxide of phthalazine

Inverse-Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate with benzene cis-diol gave dihydrodiol containing the 1,4-dihydropyridazine ring. Attempts at oxidation of the dihydropyridazine ring with PIFA and MnO₂ resulted in the formation of 5- and 5,6-dihydroxy-phthalazine derivatives. The oxidation of the dihydropyridazine ring was achieved by way of photooxygenation. The phthalazine type dihydrodiol is unstable and easily undergoes aromatization. The Diels-Alder reaction of tetrazine with cyclohexadiene acetonide and epoxy-ketal cyclohexene as a dienophile was investigated. These reactions led to the possible carcinogenic phthalazine type of dihydrodiol and diol epoxide where the hydroxyl groups are protected.     

Labelling of castor oil for myocardial study

The labelling of castor oil, hydrolyzed castor oil and oleic acid by iodine monochloride and chloramine-T has been investigated. The effect of iodinating agent and concentration of castor oil on labelling yield has been studied. A comparative pharmacological study with analogous aliphatic fatty acids was caried out. Castor oil labelled with iodine monochloride concentrates in heart and liver in good proportion, better than other natural fatty acids and nearly equal to analogous fatty acids. Infrared study revealed that the OH group in ricinoleic acid may protect the¹²⁵I added across the double bond with minor changes in biochemical properties and better extraction by the muscle of the heart.     

Reaction of Pyrimidinonethione Derivatives: Synthesis of N‐Methyl‐2‐Hydrizinopyrimidine‐4‐One,Thiazolo[3,4‐b] N‐Methylpyrimidinone; 2‐(1‐Pyrazolonyl) N‐Methylpyrimidine‐4‐one and 2‐Hydrazino‐N‐Methyl Pyrimidine‐4‐One Derivatives

6‐Aryl‐5‐cyano‐4‐pyrimidinone‐2‐thion derivatives 1a‐c reacted with methyl iodide (1:2) to give the corresponding 2‐S,N‐dimethyl pyrimidine‐4‐one derivatives 2a‐c . Compounds 2a‐c were in turn, reacted with hydrazine hydrate to give the sulfur free reaction products 3a‐c . These reaction products were taken as the starting materials for the synthesis of several new heterocyclic derivatives. Reaction of 3a‐c with acetic anhydride and formic acid gave pyrimido triazines 4a‐c and 7a‐c , respectively. Their reactions with active methylene containing reagents gave the corresponding 2‐(1‐pyrazonyl)‐N‐methyl pyrimidine derivatives 9a‐c and 10a‐c , respectively. Their reactions with aromatic aldehydes afforded the corresponding 2‐hydrazono pyrimidine derivatives 11a‐c . The structure of these reactions products were established based on both elemental analysis and spectral data studies.     

Synthesis and Reactions of Some New Heterocyclic Compounds Containing Cycloalka[e]thieno[2,3‐b]pyridine Moiety

Hydrolysis of ethyl 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxylates ( 3a-d) gave the corresponding o-aminocarboxylic acids 4a-d . Heating the latter compounds ( 4a-d) with acetic anhydride furnished the oxazinone derivatives 5a-d which, in turn, underwent recyclization reaction to give the corresponding pyrimidinones 6a-d upon treatment with ammonium acetate in acetic acid. Reaction of 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides ( 3f,h ) with triethyl orthoformate gave pyrimidinone derivatives 7a,b . Reaction of 3-amino-4-phenyl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides 3e,h with aromatic aldehydes furnished tetrahydropyridothienopyrimidinones 8a-d . Chlorination of 7a,b and 6a-d by using phosphorous oxychloride produced 4-chlorocycloalka[5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine derivatives 9a-f which were used as key intermediates in the synthesis of several new cycloalkapyrido-thienopyrimidines 10a-f ˜ 14a-f . Moreover, some cycloalkapyridothienotriazinones 15a,b-17a,b were synthesized.     

The effect of block copolymer structure on the internalization of polymeric micelles by human breast cancer cells

The objective of this study was to assess the effect of hydrophilic/hydrophobic block chain lengths on the internalization of poly(ethylene oxide)-block-poly(varepsilon-caprolactone) (PEO-b-PCL) micelles by cancer cells. PEO-b-PCL block copolymers with varied PEO and PCL chain lengths were synthesized, assembled to polymeric micelles and loaded with a hydrophobic fluorescent probe (DiI) through a co-solvent evaporation method of physical encapsulation. The slow release of the fluorescent probe from the micellar structure was evidenced following DiI transfer to lipid vesicles. The extent of micellar uptake by cancer cells was investigated through their incubation with MCF-7 cells followed by measurement of the fluorescent emission intensity of DiI (lambda=550 nm) in separated lysed cells. Cellular internalization of polymeric micelles was confirmed by laser scanning microscopy. The mechanism of micellar uptake was investigated by pretreatment of MCF-7 cells with chlorpromazine and cytochalasin B. Encapsulation of DiI in PEO-b-PCL micelles lowered the extent and rate of hydrophobic probe internalization by cancer cells. For polymeric micelles with 5000 gmol(-1) of PCL and varied PEO molecular weights of 2000, 5000 and 13,000 gmol(-1), maximum uptake was observed at a PEO molecular weight of 5000 gmol(-1). For polymeric micelles with 5000 gmol(-1) of PEO and varied PCL molecular weights of 5000, 13,000 and 24,000 gmol(-1), maximum uptake was observed at 13,000 gmol(-1) of PCL. Chlorpromazine reduced the cellular uptake of PEO-b-PCL micelles independent from the block copolymer structure, pointing to the involvement of clathrin mediated endocytosis mechanisms in the uptake of polymeric micelles by cancer cells. Inhibition of cellular uptake of PEO-b-PCL micelles by cytochalasin B, on the other hand, was found to be dependent on the chemical structure of the core/shell forming blocks.