Nonrelativistic Shifted-1 Expansion Technique for Three- and Two-Dimensional Schrodinger Equation

The shifted-1 expansion techniques (SLET) has been developed to get eigenvalues of Schrödinger equation in three (30) and two dimensions (2D). SLET simply consists of 1/l as a perturbation parameter, where l= 1 -β.β is a suitable shift, l is the angular-momentum quantum number for the 3D-case, l = |m| for the 2D-case, and m is the magnetic quantum number. Unlike the shifted large-N expansion theory (SLNT), SLET seems to be applicable to a wider number of problems of significant interest in physics.     

2,4,5‐Substituted furan‐3(2H)‐ones: Synthesis,reactions with amino acid and hydrazine derivatives

Furan‐3(2H)‐ones ( 3 ) were obtained from some 2,3‐dihydro‐furan‐2,3‐diones with a few Wittig reagents ( 2 ). The compounds of 3 with glycin and hydrazines ( 4a,b ) produced 2,3‐dihydro‐1H‐pyrrol‐3‐ones ( 5a–d ). All the reaction mechanisms were discussed by utilizing the similar reaction pathways. Structures of these compounds were determined by the IR, NMR, elemental analysis, and X‐ray diffraction method. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:235–241, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20115     

Modeling and Sensitivity Analysis of Particle Size Distribution and Chain Length Distribution in a Semibatch Emulsion Copolymerization Reactor

Summary: A comprehensive model is developed to predict the relationship between the particle size distribution and molecular weights of particles in an emulsion copolymerization reactor. A full population balance equation is used for the particle size distribution and extended to the model for the molecular properties using a continuous reactor approach. The numerical prediction clearly distinguishes the characteristics of molecular properties of particles by homogeneous nucleation from those by micellar nucleation with the dependence on the particle size. Sensitivity analysis of the proposed model under a variety of conditions shows that the compartmentalized feature of the emulsion system should be considered for better prediction of molecular properties, and provides information on the manipulated variables and lumped parameters which effectively decompose the correlation of both properties. Finally, a control strategy utilizing a lumped parameters tracking method is suggested for the regulation of both the particle size distribution and molecular properties.

Time evolution of number‐averaged molecular weights in the element under base conditions.     

2,4‐[2,2′‐Methylenebis(4‐nitrophen­oxy)]‐2,4,6,6‐tetrachlorocyclo‐2λ5,4λ5,6λ5‐triphosphazatriene (ansa)

The title compound, C₁₃H₈Cl₄N₅O₆P₃, consists of a non‐planar trimeric phosphazene ring and a bulky 2,2′‐methylenebis(4‐nitrophenoxy) side group which predominantly determines the molecular shape. With respect to the corresponding values in the reference compound N₃P₃Cl₆, the endocyclic angle around one P atom is the same, but the exocyclic angle is increased, while the endocyclic and exocyclic angles about another P atom are both decreased. This situation is different from that in other reported phosphazene derivatives.     

Functional artificial free-standing yeast biofilms

Here we report fabrication of artificial free-standing yeast biofilms built using sacrificial calcium carbonate-coated templates and layer-by-layer assembly of extracellular matrix-mimicking polyelectrolyte multilayers. The free-standing biofilms are freely floating multilayered films of oppositely charged polyelectrolytes and live cells incorporated in the polyelectrolyte layers. Such biofilms were initially formed on glass substrates of circular and ribbon-like shapes coated with thin layers of calcium carbonate microparticles. The templates were then coated with cationic and anionic polyelectrolytes to produce a supporting multilayered thin film. Then the yeast alone or mixed with various micro- and nanoparticle inclusions was deposited onto the multilayer composite films and further coated with outer polyelectrolyte multilayers. To detach the biofilms from the glass substrates the calcium carbonate layer was chemically dissolved yielding free-standing composite biofilms. These artificial biofilms to a certain degree mimic the primitive multicellular and colonial species. We have demonstrated the added functionality of the free-standing artificial biofilms containing magnetic, latex and silver micro- and nanoparticles. We have also developed "symbiotic" multicellular biofilms containing yeast and bacteria. This approach for fabrication of free-standing artificial biofilms can be potentially helpful in development of artificial colonial microorganisms composed of several different unicellular species and an important tool for growing cell cultures free of supporting substrates.     

Photophysical, photochemical and BSA binding/BQ quenching properties of quaternizable coumarin containing water soluble zinc phthalocyanine complexes

The non-peripherally (np-QZnPc) and peripherally (p-QZnPc) tetrakis-[7-oxo-(3-[(2-diethylaminomethyliodide)ethyl)]-4-methylcoumarin]-phthalocyaninatozinc complexes have been prepared by quaternization of non-peripherally and peripherally tetrakis[7-oxo-(3-[(2-diethylamino)ethyl)]-methylcoumarin] phthalocyaninato zinc complexes with methyliodide in dimethylsulfoxide (DMSO). The new quaternized zinc phthalocyanine complex (np-QZnPc) has been characterized by elemental analysis, MALDI-TOF, IR and UV-vis spectral data. The photophysical and photochemical properties of the peripherally and non-peripherally quaternized tetrakis-3-[(2-diethylamino)ethyl]-7-oxo-4-methylcoumarin substituted zinc phthalocyanines are reported. The effects of the position of the substituents and the aggregation of the phthalocyanine molecules on the photophysical and photochemical properties are also investigated. General trends are described for photodegradation, singlet oxygen and fluorescence quantum yields, and fluorescence lifetimes for complexes np-ZnPc/p-ZnPc in DMSO and for complexes np-QZnPc/p-QZnPc in DMSO, phosphate buffered solution (PBS) and PBS+Triton-X 100 solutions. The fluorescence of the tetra-substituted quaternized zinc phthalocyanine complexes (np-QZnPc/p-QZnPc) are effectively quenched addition of 1,4-benzoquinone (BQ) and this study also presented the ionic zinc phthalocyanine complexes strongly bind to bovine serum albumin (BSA).     

New Benzo-15-Crown-5 Ethers Featuring Salicylic Schiff Base Substitutions – Synthesis, Complexes and Structural Study

Condensation reactions between 4'-formyl-5'-hydroxybenzo-15-crown-5and 2-aminopyridine, 2-amino-6-methylpyridine, 2-amino-4-methylpyridine or2-(aminomethyl)furan yielded the new laterally functionalized crown ethers1–4. The crown compounds 1–3 form crystalline 1:1 (Na⁺:ligand) complexes 1a–3a with sodium perchlorate. Ligands and complexes have been characterized by elemental analyses, IR, UV-Vis, ¹H-, ¹³C-NMR and mass spectra. The tautomeric equilibria (phenol-imine, O...H–N and keto-amine, O...H–N forms) have been systematically studied by using UV-Vis absorption spectra. The spectra of the ligands 1–4 and complexes 1a–3a were recorded in polar, non-polar, acidic, and basic media. In solutions of polar solvents, tautomeric interconversion of the Schiff base into the keto-amine form has been observed. A crystal structure [monoclinic, space group P2₁/c,a = 14.292(2), b = 9.449(6), c = 16.059(2) Å, = 114.20(1)°,V = 1978.4(13) ų, Z = 4 and D_x = 1.314 g cm^-3] shows that compound 4 is in the form of phenol-imine in solid state. There is a strong intramolecular [O–H...N 1.78(6), O...N 2.581(7), O–H 0.89(6) Å and N...H–O 148.4(5)°] hydrogen bond between the phenolic oxygen and imine nitrogen atoms. The C=N imine bond reveals a trans planar (1E) configuration. The molecules stack in columns parallel to the a/c plane of the unit cell.     

Carbon-nanotube-modified glassy carbon electrodes for amplified label-free electrochemical detection of DNA hybridization

The preparation and attractive performance of carbon-nanotube modified glassy-carbon (CNT/GC) electrodes for improved detection of purines, nucleic acids, and DNA hybridization are described. The surface-confined multiwall carbon-nanotube (MWCNT) facilitates the adsorptive accumulation of the guanine nucleobase and greatly enhances its oxidation signal. The advantages of CNT/GC electrodes are illustrated from comparison to the common unmodified glassy carbon, carbon paste and graphite pencil electrodes. The dramatic amplification of the guanine signal has been combined with a label-free electrical detection of DNA hybridization. Factors influencing the enhancement of the guanine signal are assessed and optimized. The performance characteristics of the amplified label-free electrochemical detection of DNA hybridization are reported in connection to measurements of nucleic-acid segments related to the breast-cancer BRCA1 gene.     

Tentative identification of volatile flavor compounds in commercial Budu, a Malaysian fish sauce, using GC-MS

Budu is a famous Malaysian fish sauce, usually used as seasoning and condiment in cooking. Budu is produced by mixing fish and salt at certain ratio followed by fermentation for six months in closed tanks. In this study, four commercial brands of Budu were analyzed for their chemical properties (pH, salt content and volatile compounds). The pH of Budu samples ranged from 4.50-4.92, while the salt (NaCl) content ranged between 11.80% and 22.50% (w/v). For tentative identification of volatile flavor compounds in Budu, two GC columns have been used, DB-WAX and HP-5MS. A total of 44 volatile compounds have been detected and 16 were common for both columns. 3-Methyl-1-butanol, 2-methylbutanal, 3-methylbutanal, dimethyl disulfide, 3-(methylthio)-propanal, 3-methylbutanoic acid and benzaldehye have been identified as the aroma-active compounds in Budu due to their lower threshold values.     

Synthesis, characterization and catalytic behavior of functionalized mesoporous SBA-15 with various organo-silanes

Mesoporous silica SBA-15 has been synthesized and functionalized by one-step synthesis method to widen their various application possibilities. In this study, phenyltrimethoxysilane (PTMS), 3-mercaptopropyltrimethoxysilane (MPTMS) and trimethoxypropylsilane (TMPS) were used as silane precursors for the functionalization, and after treated with HCl solution, their catalytic activities were evaluated in the lactic acid-methanol esterification. The presence of anchoring of functional groups on SBA-15 was proved by XRD, FT-IR, BET surface area and pore size distributions. Good catalytic activity was observed especially for SBA-15-SO(3)H-MPTMS, and the catalytic activity order was determined as follows: SBA-15-SO(3)H-MPTMS>SBA-15-TMPS>SBA-15-PTMS, which is directly associated with the surface area, pore size and pore volume. As compared with homogeneous catalyst, SBA-15-SO(3)H-MPTMS heterogeneous catalyst shows remarkable performance, such as separation, recovery and reusability.