Strain evolution in GaN Nanowires: from free-surface objects to coalesced templates

Top-down fabricated GaN nanowires, 250 nm in diameter and with various heights, have been used to experimentally determine the evolution of strain along the vertical direction of 1-dimensional objects. X-ray diffraction and photoluminescence techniques have been used to obtain the strain profile inside the nanowires from their base to their top facet for both initial compressive and tensile strains. The relaxation behaviors derived from optical and structural characterizations perfectly match the numerical results of calculations based on a continuous media approach. By monitoring the elastic relaxation enabled by the lateral free-surfaces, the height from which the nanowires can be considered strain-free has been estimated. Based on this result, NWs sufficiently high to be strain-free have been coalesced to form a continuous GaN layer. X-ray diffraction, photoluminescence and cathodoluminescence clearly show that despite the initial strain-free nanowires template, the final GaN layer is strained

Theory and simulation of quantum photovoltaic devices based on the non-equilibrium Green's function formalism

This article reviews the application of the non-equilibrium Green's function formalism to the simulation of novel photovoltaic devices utilizing quantum confinement effects in low dimensional absorber structures. It covers well-known aspects of the fundamental NEGF theory for a system of interacting electrons, photons and phonons with relevance for the simulation of optoelectronic devices and introduces at the same time new approaches to the theoretical description of the elementary processes of photovoltaic device operation, such as photogeneration via coherent excitonic absorption, phonon-mediated indirect optical transitions or non-radiative recombination via defect states. While the description of the theoretical framework is kept as general as possible, two specific prototypical quantum photovoltaic devices, a single quantum well photodiode and a silicon-oxide based superlattice absorber, are used to illustrated the kind of unique insight that numerical simulations based on the theory are able to provide.Comment: 20 pages, 10 figures; invited review pape

ceritinib plus nivolumab in patients with advanced alk rearranged non small cell lung cancer results of an open label multicenter phase 1b study

Abstract Introduction Induction of programmed death ligand 1 (PD-L1) expression due to constitutive oncogenic signaling has been reported in NSCLC models harboring echinoderm microtubule associated protein like 4 gene (EML4)–ALK receptor tyrosine kinase gene (ALK) rearrangements. We assessed the safety and activity of ceritinib plus nivolumab in these patients. Methods In this open-label, phase 1B, multicenter, dose escalation and expansion study, previously treated (with ALK receptor tyrosine kinase [ALK] inhibitor [ALKI]/chemotherapy) or treatment-naive patients with stage IIIB or IV ALK-rearranged NSCLC received nivolumab, 3 mg/kg intravenously every 2 weeks, plus ceritinib, 450 mg/300 mg daily, with a low-fat meal. Results In total, 36 patients were treated (a 450-mg cohort [n=14] and a 300-mg cohort [n=22]). In the 450-mg cohort, four patients experienced dose-limiting toxicities. In the 300-mg cohort, two patients experienced dose-limiting toxicities. Among ALKI-naive patients, the overall response rate (ORR) was 83% (95% confidence interval [CI]: 35.9–99.6) in the 450-mg cohort and 60% (95% CI: 26.2–87.8) in the 300-mg cohort. Among ALKI-pretreated patients, the ORR was 50% (95% CI: 15.7–84.3) in the 450-mg cohort and 25% (95% CI: 5.5–57.2) in the 300-mg cohort. The ORR point estimate was observed to be greater in patients who were positive for PD-L1 than in those who were negative for PD-L1, with overlapping CIs (e.g., at a cutoff ≥1% PD-L1, 64% of patients [95% CI: 35.1–87.2] had confirmed responses as compared with those with negative PD-L1 staining (31% [95% CI: 11.0–58.7]). The most frequently reported grade 3 or 4 adverse events were increased alanine aminotransferase level (25%), increased gamma-glutamyl transferase level (22%), increased amylase level (14%), increased lipase level (11%), and maculopapular rash (11%). The incidence of all-grade rash (grouped term) was 64% in both cohorts; grade 3 rash was reported in 29% and 14% of patients in the 450-mg and 300-mg cohorts, respectively; no grade 4 rash was reported. Conclusion Ceritinib plus nivolumab has activity; ORR appears to correlate with PD-L1 at baseline. Toxicity, especially rash, is more common than with either single agent

CP-31398, a putative p53-stabilizing molecule tested in mammalian cells and in yeast for its effects on p53 transcriptional activity

BACKGROUND: CP-31398 is a small molecule that has been reported to stabilize the DNA-binding core domain of the human tumor suppressor protein p53 in vitro. The compound was also reported to function as a potential anti-cancer drug by rescuing the DNA-binding activity and, consequently, the transcription activation function of mutant p53 protein in mammalian tissue culture cells and in mice. RESULTS: We performed a series of gene expression experiments to test the activity of CP-31398 in yeast and in human cell cultures. With these cell-based assays, we were unable to detect any specific stimulation of mutant p53 activity by this compound. Concentrations of CP-31398 that were reported to be active in the published work were highly toxic to the human H1299 lung carcinoma and Saos-2 cell lines in our experiments. CONCLUSION: In our experiments, the small molecule CP-31398 was unable to reactivate mutant p53 protein. The results of our in vivo experiments are in agreement with the recently published biochemical analysis of CP-31398 showing that this molecule does not bind p53 as previously claimed, but intercalates into DNA

A framework for integrating IT governance and business/IT alignment principles.

Highly information-intensive organisations such as retail banks continuously struggle with the key issues of controlling their IT-value and achieving business-IT alignment. One main reason might be that decision makers in retail banks do not use methods to plan or improve their business-IT alignment. This study provides such a method, combining principles of two well known concepts: IT governance and strategic alignment. The developed framework provides an allocation scheme for dividing strategic IT decisions between the business and IT domain by describing practical concepts to tackle the business-IT alignment enigma. The framework is validated by interviewing a number of experts from Dutch retail banks that are strongly challenged to optimise their IT value through business-IT alignment. The validation study largely supports the applicability of the framework. Furthermore, this study provides a window of opportunities to apply it to other industries, countries or specific IS/IT applications. (aut. ref.

Belbin role diversity and team performance: is there a relationship?

Purpose: This paper aims to test the relationship between team role diversity and team performance, as one of the main assumptions behind the highly cited and used Belbin model and test. Design/methodology/approach: Data were collected among 24 teams of 144 students that participated in different rounds of a management game. All students performed a Belbin role self-test prior to the management game. Performance of the teams was measured by the grade they received for the year-end report written, and the financial results they achieved at the end of the management game. Findings: No relationship was found between team role diversity and team performance. Also, it was found that the Belbin role of the team leader was not related to team performance as well. The only significant relationship found was between the individual study results of the team members and the grade they received for the year-end report. Research limitations/implications: Results might change if team performance is measured by other indicators, such as the level of in-team collaboration or collective motivation. Practical implications: It should not be expected that creating diversity of roles within teams automatically leads to better performance. Continuous improvement, recognizing the phase team development is in, should also be in place to balance team members and support their performance. Originality/value: This paper contributes to the empirical testing of assumptions and ideas behind Belbin's model and test. Given its limitations, it provides new triggers to conduct more, similar empirical research. (aut. ref.