Investigating the pre-damaged PZT sensors under impact traction

Ships are usually under vibration, impact, and other kinds of static and dynamic loads. These loads arise from water flow across the hull or surfaces, the propeller cavitation, and so on. For optimal design purposes and reliable performance, experimental measurements are necessary. These sensors are often used under or near the water, working conditions that improve the risk of sensor damage. This paper aims at investigating, by the use of finite elements, the behavior of damaged piezoelectric sensors under traction and impact loads. The numerical method was calibrated using results available in the literature regarding piezoelectric and elastic plates with a central crack. After calibration, the simulation was used on two types of Lead-Zirconium-Titanium oxide (PZT) sandwich panel structures reinforced by aluminum skins. The results proved that the damage size and impact energy are important factors affecting the response of piezoelectric sensors; therefore, special attention might be considered when using these sensors for marine applications

Residual stress evaluation in friction stir welding of aluminum plates by means of acoustic emission and ultrasonic waves

© Faculty of Mechanical Engineering, Belgrade. The residual stress assessment in structures is essential for optimization of the structures' design. The attention of this paper is focused on how acoustic emission signals caused by tensile loading of the friction stir welded aluminum plates are expected to vary depending upon the residual stress. To this aim, the distribution of residual stresses in two friction stir welded aluminum specimens was firstly evaluated by ultrasonic stress measurement. AE signals were then produced during tensile tests and captured using AE sensors. The obtained AE signals were analyzed using statistical features including crest factor, cumulative crest factor and sentry function. It was found that the crest factor could be used to identify the presence of the residual stresses and that the trends of sentry function are in good agreement with the results of crest factor and cumulative crest factor

CASPER: A Hypermedia Departmental Information System

ABSTRACT: In this paper we discuss the design and development of CASPER (Computer Assisted Studies Planning and Educational Resources). CASPER is a hypermedia information system which allows students to find up to date information on courses, instructors, announcements, transfer credit, and frequently asked questions. One of the most important features of CASPER is its capability to assist students in planning their course selections for future terms. Because CASPER is an on-line system, additional human counselors are free to deal personally with students on less routine matters

Downregulation of Mcl-1 has anti-inflammatory pro-resolution effects and enhances bacterial clearance from the lung

Phagocytes not only coordinate acute inflammation and host defense at mucosal sites, but also contribute to tissue damage. Respiratory infection causes a globally significant disease burden and frequently progresses to acute respiratory distress syndrome, a devastating inflammatory condition characterized by neutrophil recruitment and accumulation of protein-rich edema fluid causing impaired lung function. We hypothesized that targeting the intracellular protein myeloid cell leukemia 1 (Mcl-1) by a cyclin-dependent kinase inhibitor (AT7519) or a flavone (wogonin) would accelerate neutrophil apoptosis and resolution of established inflammation, but without detriment to bacterial clearance. Mcl-1 loss induced human neutrophil apoptosis, but did not induce macrophage apoptosis nor impair phagocytosis of apoptotic neutrophils. Neutrophil-dominant inflammation was modelled in mice by either endotoxin or bacteria (Escherichia coli). Downregulating inflammatory cell Mcl-1 had anti-inflammatory, pro-resolution effects, shortening the resolution interval (R(i)) from 19 to 7 h and improved organ dysfunction with enhanced alveolar–capillary barrier integrity. Conversely, attenuating drug-induced Mcl-1 downregulation inhibited neutrophil apoptosis and delayed resolution of endotoxin-mediated lung inflammation. Importantly, manipulating lung inflammatory cell Mcl-1 also accelerated resolution of bacterial infection (R(i); 50 to 16 h) concurrent with enhanced bacterial clearance. Therefore, manipulating inflammatory cell Mcl-1 accelerates inflammation resolution without detriment to host defense against bacteria, and represents a target for treating infection-associated inflammation

Proteomics identifies neddylation as a potential therapy target in small intestinal neuroendocrine tumors.

Patients with small intestinal neuroendocrine tumors (SI-NETs) frequently develop spread disease; however, the underlying molecular mechanisms of disease progression are not known and effective preventive treatment strategies are lacking. Here, protein expression profiling was performed by HiRIEF-LC-MS in 14 primary SI-NETs from patients with and without liver metastases detected at the time of surgery and initial treatment. Among differentially expressed proteins, overexpression of the ubiquitin-like protein NEDD8 was identified in samples from patients with liver metastasis. Further, NEDD8 correlation analysis indicated co-expression with RBX1, a key component in cullin-RING ubiquitin ligases (CRLs). In vitro inhibition of neddylation with the therapeutic agent pevonedistat (MLN4924) resulted in a dramatic decrease of proliferation in SI-NET cell lines. Subsequent mass spectrometry-based proteomics analysis of pevonedistat effects and effects of the proteasome inhibitor bortezomib revealed stabilization of multiple targets of CRLs including p27, an established tumor suppressor in SI-NET. Silencing of NEDD8 and RBX1 using siRNA resulted in a stabilization of p27, suggesting that the cellular levels of NEDD8 and RBX1 affect CRL activity. Inhibition of CRL activity, by either NEDD8/RBX1 silencing or pevonedistat treatment of cells resulted in induction of apoptosis that could be partially rescued by siRNA-based silencing of p27. Differential expression of both p27 and NEDD8 was confirmed in a second cohort of SI-NET using immunohistochemistry. Collectively, these findings suggest a role for CRLs and the ubiquitin proteasome system in suppression of p27 in SI-NET, and inhibition of neddylation as a putative therapeutic strategy in SI-NET

A proteome-wide protein interaction map for Campylobacter jejuni

'Systematic identification of protein interactions for the bacterium Campylobacter jejuni using high-throughput yeast two-hybrid screens detected interactions for 80% of the organism's proteins

The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence

PURPOSE: A review of the role of the carotenoids, lutein and zeaxanthin, and their function in altering the pathogenesis of age-related macular degeneration (AMD). METHODS: Medline and Embase search. RESULTS: Recent evidence introduces the possibility that lutein and zeaxanthin, carotenoids found in a variety of fruits and vegetables may protect against the common eye disease of macular degeneration. This potential and the lack to slow the progression of macular degeneration, has fueled high public interest in the health benefits of these carotenoids and prompted their inclusion in various supplements. The body of evidence supporting a role in this disease ranges from basic studies in experimental animals to various other clinical and epidemiological studies. Whilst some epidemiological studies suggest a beneficial role for carotenoids in the prevention of AMD, others are found to be unrelated to it. Results of some clinical studies indicate that the risk for AMD is reduced when levels of the carotenoids are elevated in the serum or diet, but this correlation is not observed in other studies. Published data concerning the toxicity of the carotenoids or the optimum dosage of these supplements is lacking. CONCLUSION: An intake of dietary supplied nutrients rich in the carotenoids, lutein and zeaxanthin, appears to be beneficial in protecting retinal tissues, but this is not proven. Until scientifically sound knowledge is available we recommend for patients judged to be at risk for AMD to: alter their diet to more dark green leafy vegetables, wear UV protective lenses and a hat when outdoors. Future investigations on the role of nutrition, light exposure, genetics, and combinations of photodynamic therapy with intravitreal steroid (triamcinolone-acetonide) injections hold potential for future treatment possibilities

Fixed and random effects models: making an informed choice

This paper assesses the options available to researchers analysing multilevel (including longitudinal) data, with the aim of supporting good methodological decision-making. Given the confusion in the literature about the key properties of fixed and random effects (FE and RE) models, we present these models’ capabilities and limitations. We also discuss the within-between RE model, sometimes misleadingly labelled a ‘hybrid’ model, showing that it is the most general of the three, with all the strengths of the other two. As such, and because it allows for important extensions—notably random slopes—we argue it should be used (as a starting point at least) in all multilevel analyses. We develop the argument through simulations, evaluating how these models cope with some likely mis-specifications. These simulations reveal that (1) failing to include random slopes can generate anti-conservative standard errors, and (2) assuming random intercepts are Normally distributed, when they are not, introduces only modest biases. These results strengthen the case for the use of, and need for, these models