High quantum yield photoluminescence of new polyamides containing oligo‐PPV amino derivatives and related oligomers

The synthesis and the chemical physical characterization of new photoluminescent (PL) chromophores and polymers are reported. Chromophores (oligo‐PPV symmetric derivatives ending with amino groups) are strong blue emitters with a PL quantum yield of ～70% in dioxane solution. They have been used to prepare polyamides by reaction with aliphatic acyl dichlorides in which emitting and non emitting units are alternated. PL properties of the synthesized polyamides have been evaluated in solution and reveal a strong blue emission (PL quantum yield ～60%), To increase the solubility of these systems, oligomers have been purposely prepared and then characterized. They show a peculiar white emission when excited in DMF solution; to get insight into this interesting behavior, asymmetric monoacetylated chromophores have been prepared as model compounds for the chromophoric end groups of the polyamide chains. The emission spectra of these compounds reveal a broad excimeric yellow emission which is responsible, along with the blue emission of the inner chromophoric units, of the overall white emission of the oligomers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2677–2689, 2009     

Lyapunov's Theorem for Measures on D-posets

We generalize Lyapunov's convexity theorem for measures on effect algebras.     

FTIR spectra and structure of new polystyrenes: Syndiotactic polystyrene and poly-para-methyl-styrene

Highly syndiotactic poly(styrene) shows higher crystallinity and a higher melting point than the corresponding isotactic material. Temperature dependent FTIR spectra have been recorded and the structural evolution of the system from the ordered to the amorphous phase has been followed.     

Nonlinear Hanle effect in the active discharge of an argon laser

 We present experimental evidence of the NonLinear Hanle Effect (NLHE) on the 488 nm transition in an active discharge of an argon laser. Experimental data are used to estimate the homogeneous linewidth of the upper level of the transition. The role of the NLHE in the laser power enhancement is also discussed. Received: 22 February 1996 / Revised version: 17 June 1996     

Hydrophobic effect in aqueous solutions of nonelectrolytes. II. Cross-interactions of alkylureas

The heats of mixing of the aqueous solutions of monomethylurea, monoethylurea, 1,3-dimethylurea, 1,3-diethylurea were determined at 25°C. The excess enthalpies obtained are expressed in virial form, in terms of pair and triplet interaction coefficients. A method previously discussed for predicting the excess enthalpies and the interaction coefficients of ternary solutions has been applied to the alkylureas. The large deviations between the experimental and calculated values, led to the modification of that method, which better accounts for the marked mixed character of these substances.     

Fractional wavelet analysis for the simultaneous quantitative analysis of lacidipine and its photodegradation product by continuous wavelet transform and multilinear regression calibration

Fractional wavelet transform (FWT) was applied to the original absorption spectra of lacidipine (LAC) and its photodegradation product (LACD), and the resulting FWT spectra were processed by continuous wavelet transform (CWT) and multilinear regression calibration (MLRC) for the simultaneous quantitative analysis of both products in their binary mixtures. These methods do not require any chemical separation step and chemical complex reaction to obtain a detectable signal for the degradation product. By using the Mexican hat function, 2 calibration functions for LAC and LACD were obtained by measuring the CWT transformed signals at 416.1 nm for LAC and 414.6 nm for LACD, after FWT processing of the original absorption spectra. The calibration graphs were linear in the concentration range of 5.08-40.64 microg/mL for LAC and 0.51-8.16 microg/mL for LACD. The limit of detection and the limit of quantitation were found to be 0.289 and 0.956 microg/mL for LAC and 0.036 and 0.118 microg/mL for LACD, respectively. For comparison, the MLRC algorithm was applied to the linear regression functions for the individual drug and its photoproduct. In this approach, a set of linear regression functions was obtained from the relationship between concentrations and FWT signals in the wavelength range 411.0-412.4 nm. Both methods were applied to the quantitative evaluation of LAC and LACD in laboratory and pharmaceutical samples, and produced very satisfactory results.     

Trastuzumab quantification in serum: a new,rapid, robust ELISA assay based on a mimetic peptide that specifically recognizes trastuzumab

Trastuzumab, a humanized monoclonal antibody directed against the epidermal growth factor receptor 2 (HER2), is a milestone in the treatment of HER2-overexpressing breast cancer patients. An enzyme-linked immunosorbent assay (ELISA) for trastuzumab has been developed for routine use in the laboratory to support clinical and pharmacokinetic studies to optimize therapy. The method relies on an antigen peptide linked to a 96-well plate via the streptavidin/biotin system. The peptide sequence mimics the extracellular portion of the HER2 receptor that is recognized by trastuzumab. The calibration range of the assay is 10 to 360 ng/mL per well, corresponding to a trastuzumab serum concentration from 5 to 180 μg/mL with a lower limit of quantification of 10 μg/mL. Validation results demonstrate that trastuzumab can be accurately and precisely quantified in human serum using this assay. The procedure was also tested in sera obtained from breast cancer patients to evaluate trastuzumab serum levels, confirming the applicability of method that could be a valid assay to use in daily laboratory practice.     

Rigid chain ribbon‐like metallopolymers

A set of new copolymers is here reported in which the repeating units are connected each other through Cu(II) metal centers. The coordination link is based on the bis‐chelating properties of salicylaldiminate groups of two different monomers. Due to their chemical structure, the two monomers afford, respectively, flexible and rigid repeating units in the metallocopolymers constitution upon coordination to copper centers. All the copolymers were soluble and easily processable. As shown by XRD analysis, rigid units' rich copolymers adopt a ribbon‐like structure in solid state in which highly planar strands of polymer stack thanks to π?π interactions, similarly to the polymer composed exclusively by rigid units. This behavior can be justified assuming the existence of a partial block character in copolymer constitution where long sequences of rigid units are alternated to sequences of flexible units. This assumption is supported also by DSC and UV–Vis analysis. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2412–2421