Cathepsin E expression by normal and premalignant cervical epithelium

We have investigated the expression of the aspartic proteinase cathepsin E and HLA-DR and the presence of HPV16 in normal squamous epithelium (n = 8) and low-grade (n = 21) and high-grade (n = 14) intraepithelial squamous lesions of the uterine cervix. Immunohistochemistry of cervical biopsies revealed that up-regulation of cathepsin E expression was related to increasing severity of the cervical intraepithelial neoplasia (CIN). Up-regulation of protein was associated with increased message as assessed by in situ hybridization. Langerhans cells and the majority of koilocytes did not express detectable cathepsin E levels. Although there was also an up-regulation of HLA-DR expression by cervical keratinocytes in cervical intraepithelial neoplasia lesions, as determined by immunohistochemistry, no significant correlation was found between HLA-DR and cathepsin E expression in these lesions; neither was expression of cathepsin E correlated to the presence of HPV16, detected by polymerase chain reaction. The expression of cathepsin E, an aspartic proteinase that is reported to play a role in antigen processing for presentation by class II major histocompatibility complex molecules, is associated with cellular dedifferentiation in cervical intraepithelial neoplasia.     

Cholesterol oxides accumulate in human cataracts

Glucocorticoids induce hyperinsulinemia, hyperglycemia, and depress glucose transport by aortic endothelium. High glucocorticoid doses are used for many diseases, but with unknown effects on brain glucose transport or metabolism. This study tested the hypothesis that glucocorticoids affect glucose transport or metabolism by brain microvascular endothelium. Male rats received dexamethasone (DEX) s.c. with sucrose feeding for up to seven days. Cerebral microvessels from rats treated with DEX/sucrose demonstrated increased GLUT1 and brain glucose extraction compared to controls. Glucose transport in vivo correlated with hyperinsulinemia. Pre-treatment with low doses of streptozotocin blunted hyperinsulinemia and prevented increased glucose extraction induced by DEX. In contrast, isolated brain microvessels exposed to DEX in vitro demonstrated suppression of 2-deoxyglucose uptake and glucose oxidation. We conclude that DEX/sucrose treatment in vivo increases blood-brain glucose transport in a manner that requires the effects of chronic hyperinsulinemia. These effects override any direct inhibitory effects of either hyperglycemia or DEX.     

Constructive model-based analysis for safety assessment

The aerospace industry still uses fault trees to perform reliability analysis. This is because fault-tree modeling and analysis (FTA) seems easier to practical engineers when compared with Markov models, even though FTA provides a weaker form of analysis. In this paper, we propose an automatic strategy for generating Markov-based models and corresponding analysis formulations, according to ARP 4761, directly from Simulink diagrams annotated with failure information. The generated Markov-based models are expressed in the formal language PRISM, and the analysis is carried out by the PRISM model checker. The strategy is compositional and based on a comprehensive set of translation rules from Simulink to PRISM. We briefly address soundness and completeness of the rules and, to illustrate the application of the strategy, we apply it to a classical avionics case study: an actuator control system.     

Magnetic properties of proximity-induced superconducting copper and silver

The magnetic properties of micrometer thick, proximity-induced superconductors have been investigated in the temperature range 5×10^–4 T _CNS T _CNS . HereT _CNS is the transition temperature of the NS proximity system. By means of ac susceptibility measurements and dc magnetization curves in copper and silver, we have determined the breakdown fieldH _b , the supercooled fieldH _sc and the superheated fieldH _sh , as functions of temperature and normal metal thicknessd _N . Precise magnetization curves of specimens withd _N <15 µm at the lowest temperatures gave the screening length as function of the field H. From these data, the spatial dependence of the local critical fieldH _c (x) and of the induced order parameter _N (x) in theN side were derived in the case _N (x)>k _B T and xK _N ^–1 . HereK _N ^–1 is the Cooper pair penetration length, andx the distance form the SN interface.     

Thermal stability of polymers based on acrylamide and 2-acrylamido-2-methylpropane sulfonic acid in different temperature and salinity conditions

Partially hydrolyzed polyacrylamide (PHPA) is the most widely used polymer in enhanced oil recovery (EOR) applications. However, under conditions of high temperature and salinity, the PHPA molecules become hydrolyzed, causing a drastic reduction of the viscosity of the polymer solution due to the presence of negative charges, making the molecules more susceptible to interactions with cations. In this sense, in order to increase the stability of these polymers, an anionic monomer more resistant to cations such as 2-acrylamido-2-methylpropane sulfonic acid (AMPS) has been incorporated into the HPAM molecules. This work evaluated the thermal stability of a copolymer (acrylamide and AMPS - AN125) and a terpolymer (acrylamide, acrylate, and AMPS-FP5115) in the time course of 360 days. The tests were carried out in typical conditions of Brazilian offshore reservoirs, such as absence of oxygen, high temperature, and high salt concentration. The test method involved measurements of intrinsic viscosity in function of time and determination of the hydrolysis degree of the polymers by elemental analysis. The copolymer AN125 was more stable under the test conditions than the terpolymer FP 5115 due to the presence of a higher concentration of AMPS in the copolymer. The AMPS group was hydrolyzed to AA at a temperature of 100 °C, however, the increase in salt concentration delayed the onset of this degradation. The tests indicated that the presence of a higher AMPS content in the copolymer does not prevent the polymer from undergoing hydrolysis, but delays the polymer precipitation step in the solution.     

A systematic mapping study of software product lines testing

Context

In software development, Testing is an important mechanism both to identify defects and assure that completed products work as specified. This is a common practice in single-system development, and continues to hold in Software Product Lines (SPL). Even though extensive research has been done in the SPL Testing field, it is necessary to assess the current state of research and practice, in order to provide practitioners with evidence that enable fostering its further development.

Objective

This paper focuses on Testing in SPL and has the following goals: investigate state-of-the-art testing practices, synthesize available evidence, and identify gaps between required techniques and existing approaches, available in the literature.

Method

A systematic mapping study was conducted with a set of nine research questions, in which 120 studies, dated from 1993 to 2009, were evaluated.

Results

Although several aspects regarding testing have been covered by single-system development approaches, many cannot be directly applied in the SPL context due to specific issues. In addition, particular aspects regarding SPL are not covered by the existing SPL approaches, and when the aspects are covered, the literature just gives brief overviews. This scenario indicates that additional investigation, empirical and practical, should be performed.

Conclusion

The results can help to understand the needs in SPL Testing, by identifying points that still require additional investigation, since important aspects regarding particular points of software product lines have not been addressed yet.     

Modelling and optimization of laminated adaptive shells of revolution

In this paper two shell finite element models are presented for the structural analysis of composite laminated piezoelectric shells. One is an axisymmetric conical frustum with two nodal rings and the other is a conic shell panel with eight nodes. Both models are based in a mixed laminated theory that combines a higher order shear deformation theory for the mechanical displacement field with a layerwise representation with linear functions for the electric potential through each piezoelectric layer. In order to obtain the optimal design sensitivities analysis and optimization techniques based in the nonlinear mathematical programming are used. The design objectives can be the minimization of the deformed structure or the maximization of the natural fundamental frequency and the design variables are the electric potential difference applied to the actuators or the ply thicknesses among others.     

Stress recovery in geometrically nonlinear membranes by a Hu-Washizu finite element formulation

A class of mixed finite elements based on the Hu-Washizu functional is introduced as a strategy to reduce the spurious stress phenomena encountered with standard or displacement-based formulations for geometrically exact membranes. Selected examples compare the performance of this class of elements with that of the standard formulation and demonstrate that reduction of spurious stresses is obtained and that the stresses are more accurate than those optimally sampled in the standard formulation.     

Active control of forced vibrations in adaptive structures using a higher order model

This paper deals with a finite element formulation for active control of forced vibrations, including resonance, of thin plate/shell laminated structures with integrated piezoelectric layers, acting as sensors and actuators, based on third-order shear deformation theory. The finite element model is a single layer triangular nonconforming plate/shell element with 24 degrees of freedom for the generalized displacements, and one electrical potential degree of freedom for each piezoelectric element layer, which are surface bonded or embedded in the laminate.

The Newmark method is considered to calculate the dynamic response of the laminated structures, forced to vibrate in the first natural frequency. To achieve a mechanism of active control of the structure dynamic response, a feedback control algorithm is used, coupling the sensor and active piezoelectric layers. The model is applied in the solution of illustrative cases, and the results are presented and discussed.