The Pomraning-Eddington approximation to diffusion of light in turbid materials

The source-free diffusion problem of light in turbid media with generalized boundary conditions is considered. The intensity of light is considered as a sum of collimated and diffused radiance. In this way the problem is transformed to a source problem with a collimated source (problem 1). This problem is solved in terms of the corresponding source-free problem of simple boundary conditions (problem 2). The Pomraning-Eddington method is used to solve problem 2. Two coupled first-order differential equations are obtained involving the energy density and the radiation net flux. Weight functions are introduced in order to force the boundary conditions to be fulfilled. Numerical results are given and compared with previous calculations. The calculations show that the accuracy depends on the choice of the weight function.     

Synthesis of Some New Pyrimidothienopyridazines and Related Heterocycles

5‐Amino‐3,4‐diphenylthieno[2,3‐c]pyridazine‐6‐carbonitrile 2a was reacted with propylene diamine to give tetrahydropyrimidinyl derivative 3 . The latter compound ( 3 ) underwent certain cyclocondensation reactions to produce pyrimidothienopyridazines 4–6 . Also, the reactions of 5‐amino‐3,4‐diphenylthieno[2,3‐c]pyridazine‐6‐carboxamide with heterocyclic aldehydes and/or cycloalkanones were carried out and their products were identified. Moreover, some novel pyridazinothienopyrimidobenzimidazoles 14–17 were synthesized.     

Parameter identification of fractional-order chaotic systems using different Meta-heuristic Optimization Algorithms

Nonlinear Dynamics - Fractional-order chaotic systems (FOCS) parameter identification is an essential issue in chaos control and synchronization process. In this paper, different recent...     

Conversion of toluene on NiNaY and CeNaY zeolites

Ce–Y and Ni–Y zeolites were studied in the toluen conversion reaction before and after poisoning the acid centers by Na⁺ ions. It has been found that both Ce–Y and Ni–Y zeolites were active in the disproportionation of toluene at elevated pressures, which occur on strong Brönsted acid centers. The poisoning of the acid centers in Ni–Y zeolite led to the appearance of the activity of metallic Ni and complete change in the selectivity.

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Ce- Ni- Na⁺. , , . Ni- .

     

An Efficient Synthesis of Thiazolidine‐4‐ones with Antitumor and Antioxidant Activities

Reaction of 3‐aroyl‐1‐arylthioureas with dimethyl but‐2‐ynedioate in dichloromethane and catalyzed by triphenylphosphine at ?5°C led to (Z)‐methyl 2‐[(Z)‐2‐(4‐aroylimino)‐4‐oxo‐3‐aryl‐1,3‐thiazolidin‐5‐ylidene]acetates in good yields. The mechanism is discussed. X‐ray structure analysis of one thiazolidine derivative is described. Antitumor and antioxidant activities have been investigated. One derivative of 1,3‐thiazolidine showed moderate antiproliferative in vitro activity against hepatocellular carcinoma Hep‐G2, whereas another 1,3‐thiazolidine introduced effective antioxidant activity compared to ascorbic acid.     

Cytotoxic cembranoids from the Red Sea soft coral, Sarcophyton auritum

Chemical investigation of the Red Sea soft coral Sarcophyton auritum led to the isolation and structure elucidation of two new diterpene cembranoids; 2-epi-sarcophine (2) and (1R,2E,4S,6E,8R,11R,12R)-2,6-cembradiene-4,8,11,12-tetrol (4), as well as two known diterpene cembranoids, reported for the first time from this species, namely sarcophine (1) and (+)-7α,8β-dihydroxydeepoxysarcophine (3). Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The isolated cembranoids were found to display high cytotoxicity against HepG2 (liver cancer cell line) and MCF-7 (breast cancer cell line).     

Synthesis,reactions, and spectral characterization of some new biologically active compounds derived from thieno[2,3-c]pyrazole-5-carboxamide

The starting compound 4-amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide (1) , that has been previously synthesized according to the literature procedure, underwent a reaction with the anhydride of phthalic acid either in AcOH or DMF to give isoindolinylpyrazole-5-carboxamide 3 and pyrazolothienopyrimidoisoindoledione 4 , respectively. Also, it was subjected to react with diethylmalonate followed by hydrazinolysis by hydrazine hydrate to yield the pyrazolothienopyrimidinyl acetohydrazide 5 . The carbohydrazide derivative 5 was used as a key intermediate for the preparation of other new heterocyclic systems containing pyrazolylacetyl pyrazolothienopyrimidines and pyrazolothieno-pyrimidotriazepine compounds 6–11 . The structures of these new heterocycles have been characterized by using analytical and spectroscopic analyses (IR, ¹H-NMR, ¹³C-NMR and MS). Some derivatives of the synthesized compounds exhibited remarkable antibacterial and antifungal activities against many bacterial and fungal strains.     

Synthesis and Reactions of 1‐Amino‐5‐morpholin‐4‐yl‐6,7,8,9‐tetrahydrothieno[2,3‐c]isoquinoline

The pyrazolone derivative 4 was synthesized by reaction of carbohydrazide 2 with ethyl benzoylacetate in ethanol and p‐toluene sulphonic acid followed by cyclization upon heating in acetic acid. Chloroacylation of amino ester and amino benzoyl compounds 1 , 19 gave the chloro acetylamino derivatives 5 and 20 respectively which both of them react with different amines to afford compounds 6 , 23a‐d . Hydrolysis and decarboxlation of compound 1 yielded the aminothienotetrahydroisoquinoline 8 which was used as versatile material for synthesizing other heterocyclic compounds 9‐18 . Compound 20 react with hexamethylenetetramine and malononitrile yielded thediazepino and pyrrolo derivatives 21 , 22 respectively.     

Synthesis of some pyridine, thiopyrimidine, and isoxazoline derivatives based on the pyrrole moiety

Abstract  

Condensation of 2-acetylpyrrole with 5-methylfuran-2-carboxyaldehyde and 4-chlorobenzaldehyde in 20% NaOH give the corresponding 2-chalconylpyrroles. Some new 2-alkoxy-3-cyano-4,6-diarylpyridines were synthesized by condensation of chalcones with malononitrile, followed by cyclization in sodium alkoxide. The reactivity of chalcones towards nitrogen nucleophiles such as thiourea and hydroxylamine hydrochloride to provide thiopyrimidines and isoxazolines was investigated.     

Contribution of cell culture additives to the two-dimensional protein patterns of mouse macrophages

Low levels of fetal calf serum (FCS), used as protein supplement in cell culture medium, were traced in preparations of primary murine macrophages (bone-marrow-derived macrophages (BMM) and peritoneal macrophages (PM)). Main components of this common additive were mapped in 2-DE by means of differential image gel electrophoresis and immunoblotting. Additional washing steps in cell preparation helped to decrease the levels of the four highest abundance foetal serum proteins (serum albumin (SA), alpha1-fetoprotein (AFP), alpha1-antitrypsin (alpha1AT) and transferrin (Tf)) to less than 1% of total protein. Macrophage spot pattern was recorded in parallel and showed little variation. Results presented are supposed to be of general interest for cell preparations with similar background.