Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution.

The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies

Determination of Activation Energies from Complex Impedance Parameters of Microwave Sintered NiMgZn Ferrites

International audienceThe Ni0.2Mg0.8-xZnxFe2O4 (x = 0.2, 0.4, 0.6 & 0.8) ferrites are prepared via microwave double sintering solid state reaction method. The phase purity and structure are confirmed by diffraction studies. These investigations reveal that the lattice parameter as well as crystallite sizes are increasing with zinc content. In addition, the variation of complex impedance (Z*) parameters as a function of temperature and frequency is studied. The activation energies of ferrites are evaluated from Arrhenius plots and observed to be decreasing with increase of x value. Introduction. Spinel ferrites are used as well known electromagnetic materials such as due to their various electrical and magnetic properties [1-4]. Hiti [5] reported the variation of distinct ac-electrical properties with increase of zinc composition using conventional solid state reaction method. The microstructure and electrical properties of ferrites are analyzed by impedance (Z*) properties [6]. This approach offers discussion on real (Z') and imaginary parts (Z") of impedance providing the material properties. It also attributes the bulk and grain boundary effect from the relaxation behaviour of Z' and Z" parameters [6]. The complex impedance (Z*) is generally written as Z* = Z' – j Z". The real and imaginary parts are calculated using the equations: Z' = Z Cosφ and Z" = Z Sinφ, where φ denotes the phase [7]. In this study the authors discuss the behaviour of Z', Z" and relaxation time as a function of temperature and frequency. Also, the authors attempt to evaluate the activation energies from relaxation time

Barium titanate microspheres by low temperature hydrothermal method: studies on structural, morphological, and optical properties

The barium titanate (BT) microspheres were synthesized via the low temperature hydrothermal technique. The X-ray diffraction pattern confirmed the formation of cubic perovskite structure of the material. The average crystallite size (Dp) was found to be of 21 nm using the Scherrer method. The Williamson–Hall plot was drawn for evaluating the micro-strain and crystallite diameter. The relation between micro-strain (ε) and Dp was illustrated as a function of diffraction angle (2θ). The morphology was analyzed by field emission and transmission electron microscope. The results expressed the formation of microspheres. In addition to these, the optical bandgap (Eop) and maximum absorption wavelength (λm) were achieved to be of 3.23 eV and 340 nm, respectively. The presence of metal oxide bonds (M-O) was observed which in turn attributes the formation of cubic structure