Ferroelastic domains in lead phosphate-arsenate: An afm,X-ray diffraction,tem and Raman study

Ferroelastic domain patterns in lead phosphate-type crystals depend on their chemical composition. The intersection of ferroelastic W domain walls with the (100) surface of lead phosphate-arsenate mixed crystals has been imaged using tapping mode atomic force microscopy. Dilution of the strain leads to characteristic surface deformations which deviate from those in pure lead phosphate. In highly twinned lead phosphate-arsenate X-ray diffraction was used to show renormalization effects and scattering phenomena stemming from the twin walls. Raman-active hard modes show wall-related profile changes and low-frequency tails. Symmetry mode analysis is used to describe the displacive modes characterizing the structural distortion in lead phosphate-arsenate for the sequence K m → P2₁/c.     

Isotope Effects in the Solvolysis of Sterically Hindered Arenesulfonyl Chlorides

Solvent isotope effects in the ethanolysis of sterically hindered arenesulfonyl chlorides ruled out a proton transfer in the rate‐determining step and agreed with a S_N2 mechanism involving at least a second solvent molecule in the transition state (TS). The lack of a secondary kinetic isotope effect in the o‐alkyl groups allows us to disregard the possible contribution of σ–π hyperconjugation. The measured activation parameters are consistent with a S_N2 mechanism involving the participation of solvent molecules in the TS, possibly forming a cyclic TS through a chain of solvent molecules.     

A Kinetic Investigation of Regioselective Solvation of a Solvatochromic Dye in Aqueous Alcohols

The kinetics of methylation of the solvatochromic dye 4‐[(2,4‐dinitrobenzyli‐dene)imino]‐2,6‐diphenylphenolate by dimethyl sulfate was investigated in three aqueous alcohols (1‐propanol, ethanol, and methanol), in the search of a sharp change in its reactivity in water‐rich media. The observed kinetic results paralleled previous observations of a sharp change in the solvatochromic behavior of the dye in the same media and was supported by a QM/MM simulation of the dye in two methanol–water mixtures, which rationalized the observed sharp change in the phenolate reactivity.     

Imidazolium ionic liquids as bifunctional materials (morphology controller and pre-catalyst) for the preparation of xerogel silica’s

This article describes the preparation of xerogel silica’s by the sol–gel technique in the presence of the ionic liquids (ILs) 1-triethylene glycol monomethyl ether-3-methylimidazolium methanesulfonate 1 and 1-monoethylene glycol monomethyl ether-3-methylimidazolium methanesulfonate 2, using tetraethoxysilane as precursor. The addition of water to these ILs resulted in the formation of protonic acid. As a consequence, the ILs functioned as morphology controller and acid pre-catalyst at the same time. Characterization of these materials was performed by photography, scanning electron microscopy, thermogravimetric analysis and powder X-ray diffraction. Compact lamellar monoliths with interlamellar distances of approximately 1.5 nm and flat surfaces were obtained with both ILs. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effect of Induced Transition on the Quantum Entanglement and Coherence in Two-Coupled Double Quantum Dot System

Studying quantum properties in solid-state systems is a significant avenue for research. In this scenario, double quantum dots appear as a versatile platform for technological breakthroughs in quantum computation and nanotechnology. This work inspects the thermal entanglement and quantum coherence in two-coupled DODs, where the system is exposed to an external stimulus that induces an electronic transition within each subsystem. The results show that the introduction of external stimulus induces a quantum level crossing that relies upon the Coulomb potential changing the degree of quantum entanglement and coherence of the system. Thus, the quantum properties of the system can be tuned by changing the transition frequency, leading to the enhancement of its quantum properties.     

The rheology of recycled EVA/LDPE modified bitumen

This paper describes linear viscoelasticity, at low and intermediate temperatures, and the flow behaviour, at high temperatures, of polymer modified bitumen (PMB) containing 5 and 9 wt% recycled EVA/LDPE. The relationship between flow behaviour and microstructure of the modified bitumen was also considered, by comparison of experiments carried out in capillary and rotational rheometers and photomicrographs taken using a microscopy system whilst the sample was being sheared. Blends of 60/70 penetration grade bitumen and waste plastic (EVA/LDPE) were processed in an open mixer using a four blade propeller. Rheological tests, differential scanning calorimetry (DSC) and microscopy showed that the bitumen performance was improved by adding the recycled polymer. As a consequence, the use of recycled EVA/LDPE in PMBs can be considered a suitable and interesting alternative from both an environmental and economical point of view. The experimental results also show that pure bitumen has shear-thinning characteristics. The blending of polymer into the bitumen modifies the melt processing characteristics of the blend, whilst the viscoelastic properties of the semi-solid composite are enhanced.This paper was presented at the first Annual European Rheology Conference (AERC) held in Guimarães, Portugal, September 11-13, 2003.     

Alpha 1-antitrypsin: a novel tumor-associated antigen identified in patients with early-stage breast cancer

Several studies have demonstrated that sera from patients with cancer contain antibodies that recognize a unique group of autologous antigens called tumor-associated antigens (TAA). In the current study, we employed an immunoproteomic approach, combining 2DE, Western blot, and MALDI-MS to identify TAA in the sera of patients diagnosed with infiltrating ductal or in situ carcinoma breast cancer. Sera obtained from 25 newly diagnosed patients with stage II breast cancer and 20 healthy volunteers was evaluated for the presence of novel TAA. Alpha 1-antitrypsin (A1AT) antibodies were detected in 24 of 25 patients with breast cancer (96%) and in 2 of 20 controls (10%). Sensitivity of detection of autoantibodies against A1AT in patients with breast cancer was 96%. Our preliminary results suggest that A1AT and autoantibodies against alpha 1 antitrypsin may be useful serum biomarkers for early-stage breast cancer screening and diagnosis.