Search results for "transition"

Electrochemical deposition of CZTS thin films on flexible substrate

2014

Abstract In this work, we report some preliminary results concerning the fabrication of quaternary semiconductor Cu2ZnSnS4 (CZTS) thin films on a flexible substrate through the simultaneous electrodeposition of elements having different standard electrochemical potentials. CZTS thin films were obtained by potentiostatic deposition from aqueous baths at room temperature and under N2 atmosphere, varying bath composition. Chemical composition and structure of the electrodeposited films were evaluated by EDS, SEM, RAMAN and XRD. Preliminary results on the photoelectrochemical behaviour of the films will be also presented.

Effect of plastic deformation on the anodic electroluminescence accompanying the early stage of electrolytic oxidation of cadmium

1995

Student use of resources in Calculus and Linear Algebra

2018

International audience; In this study we have investigated the resources used by first year engineering students in a technical university in the Netherlands, for their learning of Calculus and Linear Algebra. Using a case study approach we have focused on how the resources and their use (a) differed from upper secondary school as compared to university, and (b) differed between the two university courses. The results indicate that, in terms of (a) students built on secondary school experiences and emulated these into their university courses, where some subsequently experienced difficulties. In terms of (b), we argue that the course organization and the alignment of curriculum materials wi…

Desmantling patriarchy: political practices and Spanish feminist movement slogans in the democratic transition

2010

espanolEl movimiento feminista en Espana adquirio su mayor desarrollo en los anos setenta con el inicio de la transicion democratica. El proceso transicional representaba una oportunidad para la reivindicacion de los derechos de las mujeres y poner las nuevas bases sobre el lugar que debian ocupar en la futura sociedad democratica, asi como para denunciar la represion que la dictadura impuso al colectivo femenino. Las campanas y practicas politicas desarrolladas por el movimiento feminista en Espana fueron acompanadas de simbolos y lemas que formaban parte de la produccion simbolica del movimiento feminista como movimiento social. Estas representaciones simbolicas ayudaron configurar una id…

MYCN gain and MYCN amplification in a stage 4S neuroblastoma.

2003

Abstract Stage 4S neuroblastoma is a disease associated with spontaneous regression and good survival. We present a patient whose evolution has shown the variety and complexity of this disease in infants. Biologic factors, such as ploidy, MYCN copy number, loss of 1p36, and other chromosomal gains and losses were determined. A complex pattern of genetic abnormalities, such as near-diploidy, MYCN gain (2–4 copies per haploid genome) and imbalance/deletion of 1p36 was seen in the diagnostic sample. An extensive disseminated disease after a latent period of 26 months was associated with a special genetic evolution, such as tetraploidy, MYCN amplification (2:100–500 copies), 1p36 deletion, and …

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

2015

Goodson, William H. et al.

Abstract LB-399: Chronic inhibition of mutant EGFR in NSCLC leads to EGFR TKI resistance by TGF-β1 mediated epithelial to mesenchymal transition

2011

Abstract In NSCLC, activating EGFR mutations underlie responsiveness of NSCLCs to reversible EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib. Despite initial responses, acquired resistance invariably develops, mediated by the emergence of the secondary T790M mutation and by focal amplification of MET, in approximately 50% and 30% of patients, respectively. The resistance mechanisms for the remaining 20% of cases remain elusive. EGFR TKI-sensitive HCC827 cells were exposed to graded concentrations of erlotinib for 6 months. Approximately 70% of the isolated clones were resistant to erlotinib and harbored MET amplification, and were sensitive to dual EGFR/MET inhibit…

A quest for initiating cells of head and neck cancer and their treatment.

2010

The biology of head and neck squamous cell carcinomas (HNSCC) and other cancers have been related to cancer stem-like cells (CSC). Specific markers, which vary considerably depending on tumor type or tissue of origin, characterize CSC. CSC are cancer initiating, sustaining and mostly quiescent. Compared to bulk tumors, CSC are less sensitive to chemo- and radiotherapy and may have low immunogenicity. Therapeutic targeting of CSC may improve clinical outcome. HNSCC has two main etiologies: human papillomavirus, a virus infecting epithelial stem cells, and tobacco and alcohol abuse. Here, current knowledge of HNSCC-CSC biology is reviewed and parallels to CSC of other origin are drawn where n…

Tumor and its microenvironment: a synergistic interplay.

2013

The mutual and interdependent interaction between tumor and its microenvironment is a crucial topic in cancer research. Recently, it was reported that targeting stromal events could improve efficacies of current therapeutics and prevent metastatic spreading. Tumor microenvironment is a "complex network" of different cell types, soluble factors, signaling molecules and extracellular matrix components, which orchestrate the fate of tumor progression. As by definition, cancer stem cells (CSCs) are proposed to be the unique cell type able to maintain tumor mass and survive outside the primary tumor at metastatic sites. Being exposed to environmental stressors, including reactive oxygen species …

Intratumoral Heterogeneity in EGFR-Mutant NSCLC Results in Divergent Resistance Mechanisms in Response to EGFR Tyrosine Kinase Inhibition

2015

Abstract Non–small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to ind…