Search results for " Phase"
showing 10 items of 1862 documents
Consideration of the formation of solids and gases in steady state modelling of crevice corrosion propagation
2007
Abstract One of the challenges in the simulation of crevice corrosion propagation is the rigorous treatment of non-aqueous species (gas or solids), since the appearance of a new phase in a crevice will automatically have an impact on its geometry. This paper presents a simple approach, where heterogeneous reactions are considered in a post-processing step, by determining the conditions of potential, external chemistry (pH, chloride, …) or geometry under which gas or solid phases could appear in the crevice. Thus, as function of these conditions, stability diagrams for the different phases that are liable to appear in an actively propagating crevice can be constructed. Such diagrams (e.g. di…
Antiproliferative agents that interfere with the cell cycle at the G(1)-->S transition: further development and characterization of a small library o…
2008
In this continuation of our research on derivatives containing the stilbene privileged structure or that are derived from it, we report the results of further studies carried out on the previously initiated collection of compounds. We used a parallel synthetic approach to rapidly obtain small sets of compounds and started the annotation of the library in progress by calculating some physicochemical properties to be eventually correlated with biological activities. A pharmacophore for the antiproliferative activity was also built to summarize the features of the library. We evaluated the antiproliferative and pro-apoptotic activities of all compounds as well as the cell-cycle effects of some…
Identification of a Terphenyl Derivative that Blocks the Cell Cycle in the G0−G1 Phase and Induces Differentiation in Leukemia Cells
2006
To further explore the SAR of resveratrol-related trans-stilbene derivatives, here we describe the synthesis of (a) a series of 3,5-dimethoxy analogues in which a variety of substituents were introduced at positions 2', 3', 4', and 5' of the stilbene scaffold and (b) a second group of derivatives (2-phenylnaphthalenes and terphenyls) that incorporate a phenyl ring as a bioisosteric replacement of the stilbene alkenyl bridge. We thoroughly characterized all of the new compounds with respect to their apoptosis-inducing activity and their effects on the cell cycle. One of the new derivatives, 13g, behaved differently from the others, as it was able to block the cell cycle in the G(0)-G(1) phas…
Gold(I) Biscarbene Complexes Derived from Vascular-Disrupting Combretastatin A-4 Address Different Targets and Show Antimetastatic Potential
2014
Gold N-heterocyclic carbene (NHC) complexes are an emerging class of anticancer drugs. We present a series of gold(I) biscarbene complexes with NHC ligands derived from the plant metabolite combretastatin A-4 (CA-4) that retain its vascular-disrupting effect, yet address different cellular and protein targets. Unlike CA-4, these complexes did not interfere with tubulin, but with the actin cytoskeleton of endothelial and cancer cells. For the highly metastatic 518A2 melanoma cell line this effect was accompanied by a marked accumulation of cells in the G1 phase of the cell cycle and a suppression of active prometastatic matrix metalloproteinase-2. Despite these mechanistic differences the co…
Synthesis of a technetium-99m labelledL-tyrosine derivative with thefac-99mTc(I)(CO)3-core using a simple kit-procedure
2004
Summary The synthesis of a novel technetium-99m labelled derivative of l-tyrosine as a potential tumour imaging agent for nuclear medicine diagnosis is reported. The synthesis involved the labelling precursor fac-[ 99m Tc(OH2)(CO)3] + which was synthesized using the commercially available Isolink 1 -labelling kit and the tyrosine derivative O-(N,Nbis(carboxymethyl)aminoethyl)-l-tyrosine trifluoroacetate. The labelled compound O( 99m Tc(I)-tricarbonyl-N,N-bis(carboxymethyl)aminoethyl)-l-tyrosine was obtained in a radiochemical yield of 70–80% within 60 min with a radiochemical purity greater than 98% without any HPLC purification step. Purification was achieved merely by solid phase extracti…
STRUCTURE AND PHASE TRANSITIONS IN [C(NH2)3]SbCl6 CRYSTALS
1998
Abstract The crystal structure of [C(NH2)3]SbCl6 at 298 K (monoclinic, C2/m) and 240 K (monoclinic, P21/a) has been determined. The structure consists of isolated SbCl6− anions and guanidinium cations. Differential scanning calorimetry, dilatometric and dielectric studies revealed two structural phase transitions; a first-order one at 351 K and a second-order one at 265 K. One of the two crystallographically non-equivalent anions, SbCl6−(1), disordered in the room temperature phase is postulated to contribute to the phase transition mechanism at 265 K. A ferroelastic domain structure is found below 351 K.
High-pressure studies of topological insulators Bi2Se3, Bi2Te3, and Sb2Te3
2013
Bi2Se3, Bi2Te3, and Sb2Te3 are narrow bandgap semiconductors with tetradymite crystal structure (R-3m) which have been extensively studied along with their alloys due to their promising operation as thermoelectric materials in the temperature range between 300 and 500¿K. Studies on these layered semiconductors have increased tremendously in the last years since they have been recently predicted and demonstrated to behave as 3D topological insulators. In particular, a number of high-pressure studies have been done in the recent years in these materials. In this work we summarize the main results of the high-pressure studies performed in this family of semiconductors to date. In particular, w…
Dielectric and Elastic Parameters of LixNa1-xTa0.1Nb0.9O3 Ferroelectric Solid Solution Ceramics
2011
Results of the studies of electric and elastic parameters as functions of concentration in ferroelectric LiхNa1-хTa0.1Nb0.9O3 (x = 0–0.16) solid solutions and comparative studies of the elastic properties by acoustic and contact probe techniques are reported. The electric and elastic properties of LiхNa1-хTa0.1Nb0.9O3 solid solutions are shown to be rather sensitive to structural distortion at concentration-induced structural phase transitions. The values of elastic modules obtained from acoustic measurements are found to be in good agreement with those obtained by contact probe techniques.
CyProF – Insights from a Framework for Designing Cyber-Physical Systems in Production Environments
2016
Abstract There is little experience in integrating cyber-physical systems (CPS) in production environments nowadays. A coordinated framework with reference architecture, methodology and procedural model can support the adaption of CPS by providing a pre-defined structure and guidelines. This paper describes such a framework, named CyProF, for designing CPS-based solutions in production environments. Engineers are supported by this framework in handling the complexity during the design phase. Additionally, this paper explains how the framework was used in a use case to reduce engineering efforts for a CPS-based demonstrator.
Prediction of perception using structure–activity models
2016
IntroductionThe possible link between the molecular structure and a biological activity was pointed out by Linus Pauling (1946) just before the middle of the 20th century. Nevertheless, this concept has been already suggested a century before by Emil Fisher and “lock-and-key” theory: “To use a metaphor, I would say that enzyme and glucoside are such lock and key that fit together in order to exert a reciprocal chemical effect on each other”a (Fischer, 1894). The notion that the biological properties of a compound would be a function of its chemical characteristics is now well admitted, and is closely linked to that of pharmacophore. The pharmacophore concept is related to the interaction of…