Structure of 1-(2,6-dimethylphenyl)-<Emphasis Type="Italic">N</Emphasis>-hydroxy-4,4-dimethyl-2,5-dioxo-<Emphasis Type="Italic">N</Emphasis>-phenyl-3-pyrrolidine carboxamide

The title compound is crystallized in the monoclinic space group P2₁/c with cell parameters a = 7.499, b = 13.336, c = 19.390 Å, β = 99.716°, V = 1911.4 ų, Z = 4, D _cal = 1.273 Mg/m³ at T = 120 K. The structure is refined by full-matrix least-squares procedures to final R ₁ = 0.0548 and wR ₂ = 0.1089 for 3424 reflections. Two phenyl rings are noncoplanar with regard to each other and pyrrolidine core. The structure contains intramolecular hydrogen bond.     

A note on hermite-fejér interpolation for the unit circle

In this note, an extension to the unit circle of the classical Hermite-Fejér Theorem is given.     

Nanoparticulate Hollow TiO2 Fibers as Light Scatterers in Dye‐Sensitized Solar Cells: Layer‐by‐Layer Self‐Assembly Parameters and Mechanism

Hollow structures show both light scattering and light trapping, which makes them promising for dye‐sensitized solar cell (DSSC) applications. In this work, nanoparticulate hollow TiO₂ fibers are prepared by layer‐by‐layer (LbL) self‐assembly deposition of TiO₂ nanoparticles on natural cellulose fibers as template, followed by thermal removal of the template. The effect of LbL parameters such as the type and molecular weight of polyelectrolyte, number of dip cycles, and the TiO₂ dispersion (amorphous or crystalline sol) are investigated. LbL deposition with weak polyelectrolytes (polyethylenimine, PEI) gives greater nanoparticle deposition yield compared to strong polyelectrolytes (poly(diallyldimethylammonium chloride), PDDA). Decreasing the molecular weight of the polyelectrolyte results in more deposition of nanoparticles in each dip cycle with narrower pore size distribution. Fibers prepared by the deposition of crystalline TiO₂ nanoparticles show higher surface area and higher pore volume than amorphous nanoparticles. Scattering coefficients and backscattering properties of fibers are investigated and compared with those of commercial P25 nanoparticles. Composite P25–fiber films are electrophoretically deposited and employed as the photoanode in DSSC. Photoelectrochemical measurements showed an increase of around 50 % in conversion efficiency. By employing the intensity‐modulated photovoltage and photocurrent spectroscopy methods, it is shown that the performance improvement due to addition of fibers is mostly due to the increase in light‐harvesting efficiency. The high surface area due to the nanoparticulate structure and strong light harvesting due to the hollow structure make these fibers promising scatterers in DSSCs.     

Phosphorus-nitrogen compounds part 22. Syntheses, structural investigations, biological activities and DNA interactions of new mono and bis (4-fluorobenzyl) spirocyclophosphazenes

The reactions of hexachlorocyclotriphosphazene, N₃P₃Cl₆, with mono (1 and 2) and bis(4-fluorobenzyl) diamines (3-5), FPhCH₂NH(CH₂)_nNHR (RH or FPhCH₂-), produce mono (1a and 2a) and bis(4-fluorobenzyl) monospirocyclophosphazenes (3a-5a). The tetraaminomonospirocyclophosphazenes (1b-2d) are obtained from the reactions of the partly substituted phosphazenes (1a and 2a) with excess pyrrolidine, morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD), respectively. The tetrachlorobis(4-fluorobenzyl) monospirocyclophosphazenes (4a and 5a) with excess pyrrolidine, morpholine and DASD afford the fully substituted bis(4-fluorobenzyl) monospirocyclophosphazenes (4b, 4d-5d) in boiling THF. In addition, monochlorobis(4-fluorobenzyl) monospirocyclophosphazenes (4e and 4f) have also been isolated from the reactions with excess morpholine and DASD in boiling THF. The structural investigations of the compounds have been verified by elemental analyses, MS, FTIR, ¹H, ¹³C, ¹⁹F (for 1d and 2d), ³¹P NMR, HSQC and HMBC techniques. The crystal structures of 3a, 4a, 5a and 2b have been determined by X-ray crystallography. The compounds 2a-5a, 1b-2d, 4b, 4d-5d, 4e and 4f have been screened for antibacterial effects on bacteria and for antifungal activity against yeast strains. The compounds 1b and 4b showed antimicrobial activity against three species of bacteria, Bacillus subtilis, Bacillus cereus and Staphylococcus aureus, and two fungi, Candida albicans and Candida tropicalis. Minimum inhibitory concentrations (MIC) were determined for 1b and 4b. The MIC values were found to be 5000 μM for each bacteria. The most effective compound, 4b has exhibited activity with a MIC of 312 μM for C. albicans and 625 μM for C. tropicalis. DNA-binding and the nature of the interaction with pBR322 plasmid DNA are studied. All of the compounds induce changes on the DNA mobility and intensity. Prevention of HindIII digestion with the compounds indicates that the compounds bind with AT nucleotides in DNA.     

A double-blind placebo-controlled study of 5-fluorouracil:cyclodextrin complex loaded thermosensitive gel for the treatment of HPV induced condyloma

Objective of this double-blind placebo-controlled study was to determine the efficacy of thermosensitive mucoadhesive gel loaded with 5-fluorouracil (5-FU):hydroxypropyl-ß-cyclodextrin (HP-ß-CD) complex via topical administration or intralesional injection for the treatment of human papilloma virus induced condyloma in 44 women. The diagnosis of human papilloma virus was established with clinical, histopathological and polymerase chain reaction techniques. Subjects were randomized into four parallel groups to evaluate topical or intralesional administration of drug-loaded or blank gel. The formulation used in the study consisted of 20% Pluronic PF 127 and 0.2% hydroxypropylmethylcellulose (HPMC) to render thermosensitive and mucoadhesive properties to the blank and drug-loaded gels. 5-FU was complexed to hydroxypropyl-ß-cyclodextrin to improve its solubility and this complex was loaded into thermosensitive gel to obtain controlled release of the cytotoxic drug in administration site over a two-week period cure regimen aiming therapeutic efficacy with lower 5-FU doses. Complete response was achieved in 61% of patients through intralesional administration while topical administration resulted in only 29% complete cure. Relapse rates of all therapy groups were significantly low in the 6-month follow-up time.     

Bound State Solutions of the Dirac Equation for the Eckart Potential with Coulomb-Like Yukawa-Like Tensor Interactions

In this paper, we present the approximate bound state solutions of the Dirac equation within the framework of spin and pseudospin symmetries for Eckart potential for arbitrary κ—state using Nikiforov–Uvarov method. The tensor interactions of Coulomb-like and Yukawa-like form are considered and the effects of these tensors and the degeneracy removing role are discussed in detail. Numerical results and figures to show the effect of the tensor interactions are also reported.     

Photochromic and fluorescence properties of coumarin fulgimides

Four new fulgimides possessing a fluorescent coumarin unit were synthesized from the corresponding fulgides, and their photochromic as well as fluorescence properties were investigated. The open-ring forms of coumarin fulgimides were found to exhibit fluorescence in the visible region. Upon exposure to UV light, the fulgimides were transformed into the nonfluorescent closed-ring forms, which can be reverted to the initial fluorescent open-ring forms on exposure to visible light. The efficiency of quenching of fluorescence was as high as 95% at the photostationary state of UV irradiation.     

Crystal Structure of N-(tert-Butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)cyclohexane Carboxamide

Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been determined. The title compound crystallized in the orthorhombic space group pbca with cell parameters, a = 10.6556(6) ?, b = 18.0132(11) ?, c = 19.5513(12) ?, v = 3752.7(4) ?³, Z = 8, D _cal = 1.269 Mg/m³ at T = 120 K. The structure refined by full-matrix least-squares procedures to find R ₁ = 0.0463 and wR ₂ = 0.0937 for 3059 reflections. The soxazole ring isn’t coplanar with the phenyl ring. Index Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been studied.      

Quantized electron accumulation states in indium nitride studied by angle-resolved photoemission spectroscopy

Electron accumulation states in InN have been measured using high resolution angle-resolved photoemission spectroscopy (ARPES). The electrons in the accumulation layer have been discovered to reside in quantum well states. ARPES was also used to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level E(F). The energy of the Fermi level and the size of the Fermi surface for these quantum well states could be controlled by varying the method of surface preparation. This is the first unambiguous observation that electrons in the InN accumulation layer are quantized and the first time the Fermi surface associated with such states has been measured.