Designing CIGS solar cells with front-side point contacts

In this work we show how 2D numerical simulations can be used to design and optimize front-side point contacts in surface-passivated CIGS cells. Detailed analysis of the combinations of passivation thickness, point contact size and pitch can help identifying solutions able to boost the performance of otherwise surface-limited cells: efficiencies close to those of cells with ideal (i.e., trap-free) CdS/CIGS interface can be achieved by the optimization of point contact features in the low nm range. The effect of varying the CIGS and CdS doping densities on the cell performance has also been analyzed

Thermal design and characterization of a modular integrated liquid cooled 1200 V-35 A SiC MOSFET bi-directional switch

The aim of this work is the thermal design of a modular direct liquid cooled package for 1200 V–35 A SiC power MOSFETs, in order to take full advantage of the high power density and high frequency performance of these devices, in the development of a modular integrated solution for power converters. An accurate electro-thermal fluid dynamic model is set up and validated by thermal characterization on a prototype; numerical models have been used to study the internal temperature distribution and to propose further optimization

Samhd1 phosphorylation and cytoplasmic relocalization after human cytomegalovirus infection limits its antiviral activity

SAMHD1 is a host restriction factor that functions to restrict both retroviruses and DNA viruses, based on its nuclear deoxynucleotide triphosphate (dNTP) hydrolase activity that limits availability of intracellular dNTP pools. In the present study, we demonstrate that SAMHD1 expression was increased following human cytomegalovirus (HCMV) infection, with only a modest effect on infectious virus production. SAMHD1 was rapidly phosphorylated at residue T592 after infection by cellular cyclin-dependent kinases, especially Cdk2, and by the viral kinase pUL97, resulting in a significant fraction of phosho-SAMHD1 being relocalized to the cytoplasm of infected fibroblasts, in association with viral particles and dense bodies. Thus, our findings indicate that HCMV-dependent SAMHD1 cytoplasmic delocalization and inactivation may represent a potential novel mechanism of HCMV evasion from host antiviral restriction activities

p53 over-expression identifies a subset of nodal peripheral T-cell lymphomas with a distinctive biological profile and poor clinical outcome

Peripheral T-cell lymphomas (PTCL) are usually characterized by aggressive clinical behaviour and poor clinical outcome, but their biological background has not been extensively investigated to date, due to their low incidence, about 10%, of all non-Hodgkin's lymphoma cases in Western countries, and also to the paucity of specific molecular-genetic abnormalities. Neverthless, there is increasing biological and clinical evidence that primary nodal PTCL should be considered separately from extra-nodal cases, but little is known about biological factors of possible clinical and prognostic impact. This immunohistochemical study has analysed the expression of p53, Mdm2, p21(WAF1), BCL-2 and p-glycoprotein (MDR-1 gene product) in a series of 45 cases of nodal peripheral T-cell lymphomas (PTCL) with 'high-grade' histology. The immunohistochemical findings were then correlated with proliferative activity and clinical outcome. p53 was overexpressed in 13 cases (28.9%). p53 positive cases showed significantly higher proliferative activity (p <0.01), more frequent expression of Bcl-2 (p <0.01) and less frequent expression of p21(WAF1) than p53 negative cases. Mdm2 and p-glycoprotein were expressed in 4/13 (30.8%,) and 8/13 (61.5%.) p53 positive cases respectively, and in none (0%.) of the p53 negative cases (p <0.01). Analysis of the survival curves showed that p53 positive cases were associated with a significantly poorer clinical outcome than p53 negative cases, in terms of both overall survival (p = 0.0032) and event-free survival (p = 0.0004). Furthermore, multivariate analysis showed that p53 expression was the most important independent prognostic variable. These findings indicate that p53 overexpression identifies a subset of nodal PTCL cases with a distinctive biological profile (higher proliferative activity, less frequent expression of p21(WAF1) and more frequent expression of Bcl-2, Mdm2 and p-glycoprotein than p53 negative cases) and poor clinical outcome. The immunohistochemical analysis of p53 expression is a simple, rapid and low-cost method which may provide information of potential clinical and prognostic value in nodal peripheral T-cell lymphomas. Copyright (C) 2001 John Wiley & Sons, Ltd

Indagine conoscitiva sulla diffusione dell'ICT nella Pubblica Amministrazione delle Marche svolta dal Laboratorio per l'Analisi dello Sviluppo territoriale

Project CRC - Centri Regionali di Competenza per l'e-government e la societa' dell'Informazione -Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 , Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal