Denaturing capillary electrophoresis for automated detection of L858R mutation in exon 21 of the epidermal growth factor receptor gene in prediction of the outcome of lung cancer therapy

The presence of activating mutations within the tyrosine kinase domain of the epidermal growth factor receptor gene has been attributed to a positive response to biological therapy of lung cancer by small‐molecular tyrosine kinase inhibitors, gefitinib and erlotinib. Among the two most significant mutation types are deletions in exon 19 and a single point substitution in exon 21 (termed L858R). The exon 19 deletions can readily be examined by fragment analysis, due to the characteristic length difference between the normal and mutated PCR product. Analysis of the L858R point mutation, however, presents a greater challenge. The current paper is aimed at developing a sensitive, yet simple, low‐cost mutation detection assay directed at the L858R mutation using a method based on CE of heteroduplexes under partial denaturing conditions. We perform optimization of separation conditions on different commercial instruments including ones equipped with 8, 16 and 96 capillaries. We present normalized migration reproducibility in the range from 1 (8 and 16) to 5% (96) RSD. A reliable distinction of the R836R silent polymorphism from a potential presence of the L858R mutation is also demonstrated. In its implementation, the presented assay is just another application running on a conventional CE platform without the need of dedicated instrumentation.     

Utility of Radiotracer Methodology in Scientific Research of Industrial Relevancy

Utilization of radiotracer methodology in industrial research provides substantial scientific rather than directly demonstrable economic benefits. These benefits include better understanding of industrial processes and subsequently the development of new ones. Examples are given of the use of radiotracers in technological studies and the significance of the obtained results is put down. Creative application of radiotracer methodology may contribute to the economic development and technological advancement of all countries including the developing ones.     

Difluorophosphoryl Nitrene F2P(O)N: Matrix Isolation and Unexpected Rearrangement to F2PNO

Triplet difluorophosphoryl nitrene F₂P(O)N (X³A′′) was generated on ArF excimer laser irradiation (λ=193 nm) of F₂P(O)N₃ in solid argon matrix at 16 K, and characterized by its matrix IR, UV/Vis, and EPR spectra, in combination with DFT and CBS‐QB3 calculations. On visible light irradiation (λ>420 nm) at 16 K F₂P(O)N reacts with molecular nitrogen and some of the azide is regenerated. UV irradiation (λ=255 nm) of F₂P(O)N (X³A′′) induced a Curtius‐type rearrangement, but instead of a 1,3‐fluorine shift, nitrogen migration to give F₂PON is proposed to be the first step of the photoisomerization of F₂P(O)N into F₂PNO (difluoronitrosophosphine). Formation of novel F₂PNO was confirmed with ¹⁵N‐ and ¹⁸O‐enriched isotopomers by IR spectroscopy and DFT calculations. Theoretical calculations predict a rather long P? N bond of 1.922 Å [B3LYP/6‐311+G(3df)] and low bond‐dissociation energy of 76.3 kJ mol^?1 (CBS‐QB3) for F₂PNO.     

A quest for the optimal additive in chiral preparative chromatography

Traditionally, the choice of acid/base additives used in chiral preparative chromatography has not been considered very important. However, it was recently demonstrated that strongly adsorbing additives can result in the most unexpected enantiomer band shapes in modern chiral preparative chromatographic systems. In the present study we demonstrate that, depending on the choice of additive, it is actually possible to obtain the following four binary band-shape compositions when a racemic mixture is injected: (i) anti-Langmuir/anti-Langmuir, (ii) anti-Langmuir/Langmuir, (iii) Langmuir/Langmuir and (iv) Langmuir/anti-Langmuir. Further, we made an advanced numerical investigation, in order to ascertain which one of the four band-shape compositions, is the most favourable one in preparative batch chromatography of a racemic mixture. We found that if the target for purification is either the first eluting enantiomer or both ones, the traditional Langmuir/Langmuir band-shape composition should be chosen. But, if only the second eluting enantiomer is to be purified the optimal situation is the anti-Langmuir/Langmuir band-shape composition. Thus, it was concluded that the best choice of additive depends on which enantiomer is of interest and it is useful to perform a thorough additive screening to find the optimal additive, giving the most advantageous peak shape composition and accordingly the best process performance for a particular separation problem.     

Thick porous tungsten trioxide films by anodization of tungsten in fluoride containing phosphoric acid electrolyte

In the present work, we report on the formation of mesoporous thick tungsten trioxide films grown on tungsten foil by anodization in fluoride containing concentrated phosphoric acid (85%) electrolyte. Under optimized experimental conditions, mesoporous WO₃ films with a thickness up to approximately 2 μm are formed. SEM shows the films to consist of a connected network with a typical pore and feature diameter of ca 50 nm. These films as formed are amorphous and can be annealed to orthorhombic WO₃ structure. These thick porous films can show significant enhanced electrochromic and improved photocatalytic properties.     

Improved efficiency of TiO2 nanotubes in dye sensitized solar cells by decoration with TiO2 nanoparticles

In the present work we investigate the effect of TiCl₄ treatments on the photoconversion efficiency of TiO₂ arrays used in dye sensitized solar cell. The results clearly show that by an appropriate treatment the decoration of the TiO₂ nanotube arrays with TiO₂ nanocrystallites of a typical size of 3 nm can be achieved. These particles can be converted to mixture of anatase and rutile phase by annealing in air. This decoration of the TiO₂ nanotubes leads to a significantly higher specific dye loading and, for certain annealing treatments, to a doubling of the solar cell efficiency (in our case from 1.9% to 3.8% of AM 1.5 conditions) can be achieved.     

Oxide nanotubes on Ti-Ru alloys: strongly enhanced and stable photoelectrochemical activity for water splitting

The present work shows a significant enhancement of the photoelectrochemical water-splitting performance of anodic TiO(2) nanotube layers grown on low concentration (0.01-0.2 at% Ru) Ti-Ru alloys. Under optimized preparation conditions (0.05 at% Ru, 450 °C annealing) the water splitting rate of the oxide tubes could be 6-fold increased. Moreover, the beneficial effect is very stable with illumination time; this is in contrast to other typical doping approaches of TiO(2).     

Injection profiles in liquid chromatography II: predicting accurate injection-profiles for computer-assisted preparative optimizations

In computer assisted optimization of liquid chromatography it has been known for some years that it is important to use experimental injection profiles, instead of rectangular ones, in order to calculate accurate elution bands. However, the incorrectly assumed rectangular profiles are still mostly used especially in numerical optimizations. The reason is that the acquisition of injection profiles, for each injection volume and each flow rate considered in a computer-assisted optimization requires a too large number of experiments. In this article a new function is proposed, which enables highly accurate predictions of the injection profiles and thus more accurate computer optimizations, with a minimum experimental effort. To model the injection profiles for any injection volume at a constant flow rate, as few as two experimental injection profiles are required. If it is desirable to also take the effect of flow rate on the injection profiles into account, then just two additional experiments are required. The overlap between fitted and experimental injection profiles at different flow rates and different injection volumes were excellent, more than 90%, using experimental injection profiles from just four different injection volumes at two different flow rates. Moreover, it was demonstrated that the flow rate has a minor influence on the injection profiles and that the injection volume is the main parameter that needs to be accounted for.     

Enhanced water splitting activity of M-doped Ta(3)N(5) (M = Na, K, Rb, Cs)

We use a highly aligned Ta(2)O(5) nanochannel structure to fabricate alkali metal ion (Na, K, Rb or Cs) doped Ta(3)N(5)via solution seeding and thermal conversion in NH(3). Under optimized conditions the resulting doped structures show a strongly enhanced visible light water splitting performance in comparison to undoped Ta(3)N(5).