Biological aspects of new organotin(IV) compounds of 3-maleimidopropionic acid

Four new compounds of organic mono carboxylic acid, 3-maleimidopropionic acid; with Bu₂Sn(IV)²⁺, Ph₃Sn(IV)⁺ and Cychex₃Sn(IV)⁺ having ligand to metal ratio 1:2 and 1:1 were prepared. The spectrophotometric techniques used for structure determination like ¹H-, ¹³C- and ¹¹⁹Sn-NMR, FT IR and ^119mSn Mössbauer have demonstrated that the organotin(IV) moieties establish chemical bonding with the ligand through carboxylic oxygen atom. The percent CHN analyses and MS data also corroborates the spectroscopic results. During in vitro LD₅₀, anti-fungal, anti-bacterial and anti-yeast bioassays promising results were exhibited. In vitro anti-tumour activity assays against five human tumor cell lines, MCF-7 Breast cancer-EVSA-T Breast cancer-WiDr Colon cancer-IGROV Ovarian cancer-M226 Non small cell lung cancer and anti-inflammatory screenings furnished the significant toxicities of the title complexes. In addition the triorganotin(IV) complexes were comparatively less toxic than the diorganotin(IV) complexes.     

Influence of coupling agent chain lengths on interfacial performances of polyarylacetylene resin and silica glass composites

The influence of chain lengths on interfacial performances of polyarylacetylene (PAA)/silica glass composites was studied. In order to obtain different chain lengths on substrates, methyltrimethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane and dodecyltrimethoxysilane were grafted onto silica glass surface. Topographies of silica glass surface and the wetting ability of PAA resin on silica glass surface were characterized by atomic force microscopy (AFM) and surface free energy along with contact angles, respectively. At the same time, the interfacial adhesion was evaluated by shear strength testing. The failure mechanisms of composites were also analyzed by fracture morphologies. The results of the study indicate that with chain lengths of coupling agents on silica glass surface increasing, interfacial shear strengths of PAA/silica glass composites increase, while the wetting ability of PAA resin on silica glass surface decreases. The main mechanism for the improvement of the interfacial adhesion is physical entanglement interaction between the chain of coupling agent and the chain of PAA resin.     

Scaling of betatron X-ray radiation

Energetic electron beams accelerated in a laser-produced plasma wakefield cavity can generate collimated beams of X-ray radiation. The oscillation of the electrons in the plasma cavity produces synchrotron-like emission, called betatron radiation. On the basis of state of the art experiments, we discuss the potentiality of this source in terms of spectral brigthness and flux. These characteristics are compared to existing and planned X-ray sources in both laser and accelerator communities.     

A New Method for Calculation of Single Seismic Phase of Cylindrically Multilayered Media Including Liquid Interlayer

A new method based on generalized reflection and transmission （R/T） coefficients method is proposed to calculate the single seismic phase （SSP） of cylindrically multilayered media including liquid interlayer. The use of normalization factors and normalized Lamé coefficients makes the algorithm stable numerically. Using the modified R/T matrices, we derive the iterative expressions of generalized R/T matrices, and by using the iterative relation we determine the SSP of each interface and the full waveforms. To show the superiority of this new approach for investigating of reflection and transmission properties of cylindrically multilayered media, we simulate the full waveforms and SSPs of cased hole model with annulus I （casing-cement interface） channelling （or, cross-flow）. The generalized reflection coefficient spectra and SSPs of interfaces obtained show the propagation mechanism of each component of full waveform clearly.     

Observation of ferromagnetic ordering in Mn‐doped 8‐hydroxy‐quinoline aluminum

The ferromagnetic property of Mn‐doped 8‐hydroxy‐quinoline aluminum (Alq₃), synthesized by thermal co‐evaporation of pure Mn metals and Alq₃ powders, was investigated. The weak ferromagnetic property was observed in 5%‐doped Alq₃, with saturation magnetization of around 0.05μ_B/Mn. The doped Mn chemically interacted with O atoms, producing a new gap state at 0.34 eV above the highest occupied molecular orbital and reducing the effective electron concentration. This led to the decrease of the electron affinity and increase of the optical bandgap, resulting in the reduction of the hole‐injection barrier in comparison with the electron‐injection barrier to the Alq₃ layer. From these, the origin of the observed ferromagnetism is suggested. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Nanocylinder-array structure greatly increases the soft X-ray intensity generated from femtosecond-laser-produced plasma

In order to increase the soft X-ray conversion efficiency for the femtosecond-laser-produced plasma, we adopted a nanocylinder-array structure target. Gold nanocylinder-array targets with 70–90 nm cylinder diameter and 100 nm cylinder pitch were made. A continuous smooth soft X-ray spectrum adequate for X-ray absorption spectroscopy was obtained. An around 20-fold soft X-ray (7–20 nm) fluence enhancement compared with a flat-surface gold foil target was obtained when the cylinder height was 18 μm. X-ray (>0.06 keV) pulse duration was 17 ps, which is much shorter than that obtained by using the pre-pulse technique. The X-ray pulse peak intensity was 7-fold higher than that of a gold foil target. Received: 2 May 2001 / Revised version: 1 June 2001 / Published online: 18 July 2001     

Polymer-based multi-layer conductive electrode film for plastic LCD applications

Thin films of polymer-based multi-layer conductive electrode to be used as a substrate for a plastic liquid crystal display (LCD) have been prepared by a DC magnetron roll-to-roll sputtering method. The conductive layer is composed of three layers, ITO/Ag/ITO or ITO/APC/ITO, where APC is Ag-Pd-Cu alloy, on the polymer substrate (Arton?), which has been treated with hard-coat and gas-barrier layers. The properties of the conductive electrode for the plastic LCD were the following: (1) sheet resistance is 6 Ω/square; (2) transparency is 88% at 550 nm; (3) H₂O gas permeation through the plastics is 0.35 g/m² in 24 h; (4) durability against solvents is good for 5% NaOH solution, IPA, methanol, NMP, acetone, etc.; (5) the irreversible shrinkage and the compaction rate are both less than 3 ppm/h after annealing for 100 h at 150 °C. Received: 22 January 2001 / Accepted: 30 January 2001 / Published online: 26 April 2001     

Influence of laser pulse width on absolute EUV-yield from Xe-clusters

Using 50 fs ( ∼ 2×10¹⁸ W/cm²) and 2 ps ( ∼ 5×10¹⁶ W/cm²) pulses from a Ti:Sa multi-TW laser at 800 nm wavelength large Xe-clusters ( 10⁵...10⁶ atoms per cluster) have been excited. Absolute yield measurements of EUV-emission in a wavelength range between 10 nm and 15 nm in combination with cluster target variation were carried out. The ps-laser pulse has resulted in about 30% enhanced and spatially more uniform EUV-emission compared to fs-laser excitation. Circularly polarized laser light instead of linear polarization results in enhanced emission which is probably caused by electrons gaining higher energies by the polarization dependent optical field ionization process. An absolute emission efficiency at 13.4 nm of up to 0.8% in 2π sr and 2.2% bandwidth has been obtained. Received 11 January 2001 and Received in final form 27 March 2001     

β-( N -Acylamino)vinylphosphonium Salts--Synthesis and Properties

A reaction of g -carbonyl phosphorus ylides with imidoyl halides gives hitherto unknown g -( N -acylamino)vinylphosphonium salts. The same product can be obtained using the N-monosubtituted amide/Ph 3 PBr 2 /Et 3 N system instead of imidoyl halide. The key step of the reaction probably involves an intramolecular [1,3] O-to-N migration of the vinyl group, converting the primary O -imidoylation product into g -( N -acylamino)vinylphosphonium salt.     

Comparison of tunneling through molecules with Mott-Hubbard and with dimerization gaps

In order to study the tunneling of electrons through an interacting, 1D, dimerized molecule connected to leads, we consider the persistent current in a ring embedding this molecule. We find numerically that, for spinless fermions, a molecule with a gap mostly due to interactions, i.e. a Mott-Hubbard gap, gives rise to a larger persistent current than a molecule with the same gap, but due only to the dimerization. In both cases, the tunneling current decreases exponentially with the size of the molecule, but more slowly in the interacting case. Implications for molecular electronic are briefly discussed. Received: 17 November 1997 / Revised: 16 January 1998 / Accepted: 16 January 1998