A Systems Engineering Approach to Integrated Structural Health Monitoring For Aging Aircraft

The United States Air Force and many of its Coalition partners have extended the original service life of some of their aging aircraft due to fiscal constraints. This life extension often requires increased periodic and in-depth inspections; increasing maintenance costs and resulting in longer periods of aircraft downtime. A structural health monitoring system for aging aircraft could reduce the current inspection burden, and thus decrease costs and system downtime. This presentation describes a baseline systems engineering methodology for system definition of an aging aircraft structural health monitoring system. Analysis was performed to quantify the potential benefit a structural health monitoring affords

Response determination of linear dynamical systems with singular matrices: A polynomial matrix theory approach

An approach is developed based on polynomial matrix theory for formulating the equations of motion and for determining the response of multi-degree-of-freedom (MDOF) linear dynamical systems with singular matrices and subject to linear constraints. This system modeling may appear for reasons such as utilizing redundant DOFs, and can be advantageous from a computational cost perspective, especially for complex (multi-body) systems. The herein developed approach can be construed as an alternative to the recently proposed methodology by Udwadia and coworkers, and has the significant advantage that it circumvents the use of pseudoinverses in determining the system response. In fact, based on the theoretical machinery of polynomial matrices, a closed form analytical solution is derived for the system response that involves non-singular matrices and relies on the use of a basis of the null space of the constraints matrix. Several structural/mechanical systems with singular matrices are included as examples for demonstrating the validity of the developed framework and for elucidating certain numerical aspects

First treatment of mycosis fungoides by total skin electron beam (TSEB) therapy in Greece

BackgroundMycosis fungoides (MF), the most common subtype of cutaneous T-Cell Lymphoma (CTCL), is a rare chronic skin neoplasia. Total skin electron irradiation has been employed along with a variety of other topical or systemic treatments for MF management.AimTo report the first case treated by TSEB irradiation protocol in Greece.Materials and methodsA fractionated 36[[ce:hsp sp="0.25"/]]Gy total skin electron beam (TSEB) therapy was prescribed to a 65-years-old male patient with mycosis fungoides (MF), stage IIB, refractory to several treatments during a 20-year period. Dose uniform delivery was monitored by thermo-luminescence dosimetry.Results and discussionThe homogeneous skin dose distribution resulted in a complete clinical response. Limited, irradiation-oriented, side effects appeared.ConclusionsThe first TSEB irradiation prescription in Greek medical chronicles was proved effective in this case of tumor stage MF (T3-IIB), which had been refractory to several single or combination treatments

Evaluation of DNA ploidy in relation with established prognostic factors in patients with locally advanced (unresectable) or metastatic pancreatic adenocarcinoma: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Most patients with ductal pancreatic adenocarcinoma are diagnosed with locally advanced (unresectable) or metastatic disease. The aim of this study was to evaluate the prognostic significance of DNA ploidy in relation with established clinical and laboratory variables in such patients.</p> <p>Methods</p> <p>Two hundred and twenty six patients were studied retrospectively. Twenty two potential prognostic variables (demographics, clinical parameters, biochemical markers, treatment modality) were examined.</p> <p>Results</p> <p>Mean survival time was 38.41 weeks (95% c.i.: 33.17–43.65), median survival 27.00 weeks (95% c.i.: 23.18–30.82). On multivariate analysis, 10 factors had an independent effect on survival: performance status, local extension of tumor, distant metastases, ploidy score, anemia under epoetin therapy, weight loss, pain, steatorrhoea, CEA, and palliative surgery and chemotherapy. Patients managed with palliative surgery and chemotherapy had 6.7 times lower probability of death in comparison with patients without any treatment. Patients with ploidy score > 3.6 had 5.0 times higher probability of death in comparison with patients with ploidy score < 2.2 and these with ploidy score 2.2–3.6 had 6.3 times higher probability of death in comparison with patients with ploidy score < 2.2.</p> <p>Conclusion</p> <p>According to the significance of the examined factor, survival was improved mainly by the combination of surgery and chemotherapy, and the presence of low DNA ploidy score.</p

The interplay of KRAS mutational status with tumor laterality in non-metastatic colorectal cancer: An international, multi-institutional study in patients with known KRAS, BRAF, and MSI status

Background: Although the prognostic relevance of KRAS status in metastatic colorectal cancer (CRC) depends on tumor laterality, this relationship is largely unknown in non-metastatic CRC. Methods: Patients who underwent resection for non-metastatic CRC between 2000 and 2018 were identified from institutional databases at six academic tertiary centers in Europe and Japan. The prognostic relevance of KRAS status in patients with right-sided (RS), left-sided (LS), and rectal cancers was assessed. Results: Of the 1093 eligible patients, 378 had right-sided tumors and 715 had left-sided tumors. Among patients with RS tumors, the 5-year overall (OS) and recurrence-free survival (RFS) for patients with KRASmut versus wild-type tumors was not shown to differ significantly (82.2% vs. 83.2% and 72.1% vs. 76.7%, respectively, all p >.05). Among those with LS tumors, KRAS mutation was associated with shorter 5-year OS and RFS on both the univariable (OS: 79.4% vs. 86.1%, p =.004; RFS: 68.8% vs. 77.3%, p =.005) and multivariable analysis (OS: HR: 1.52, p =.019; RFS: HR: 1.32, p =.05). Conclusions: KRAS mutation status was independently prognostic among patients with LS tumors, but this association failed to reach statistical significance in RS and rectal tumors. These findings confirm reports in metastatic CRC and underline the possible biologic importance of tumor location

Liver craft preservation with continuous cold perfusion through the portal vein.

ΣΚΟΠΟΣ ΤΗΣ ΜΕΛΕΤΗΣ ΗΤΑΝ ΝΑ ΚΑΘΟΡΙΣΕΙ ΤΙΣ ΙΣΤΟΛΟΓΙΚΕΣ ΑΛΛΟΙΩΣΕΙΣ ΠΟΥ ΣΥΜΒΑΙΝΟΥΝ ΚΑΤΑ ΤΗ ΔΙΑΡΚΕΙΑ ΤΗΣ ΥΠΟΘΕΡΜΙΚΗΣ ΔΙΑΤΗΡΗΣΗΣ ΤΩΝ ΗΠΑΤΙΚΩΝ ΜΟΣΧΕΥΜΑΤΩΝ,ΝΑ ΕΛΕΓΞΕΙ ΤΗΣ ΑΣΦΑΛΕΙΑ ΚΑΙ ΑΞΙΟΠΙΣΤΙΑ ΜΙΑΣ ΑΠΛΗΣ ΜΕΘΟΔΟΥ ΓΙΑ ΠΑΡΑΤΕΤΑΜΕΝΗ ΔΙΑΤΗΡΗΣΗ ΤΩΝ ΗΠΑΤΙΚΩΝ ΜΟΣΧΕΥΜΑΤΩΝ,ΜΕ ΒΑΣΗ ΤΗ ΣΥΝΕΧΗ ΕΓΧΥΣΗ ΨΥΧΡΟΥ ΔΙΑΛΥΜΑΤΟΣ ΔΙΑ ΤΗΣ ΠΥΛΑΙΑΣ ΦΛΕΒΑΣ.ΟΙ ΕΞΗΣ ΜΕΘΟΔΟΙ ΔΙΑΤΗΡΗΣΗΣ ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΑΝ:Α) ΑΠΛΗ ΥΠΟΘΕΡΜΙΚΗ ΔΙΑΤΗΡΗΣΗ(Α.Υ.Δ.),Β) ΣΥΝΕΧΗΣ ΜΙΚΡΟ-ΕΓΧΥΣΗ(MICRO-PERFUSION) ΜΕ ΨΥΧΡΟ ΔΙΑΛΥΜΑ ΔΙΑ ΤΗΣ ΠΥΛΑΙΑΣ ΜΕ ΧΑΜΗΛΟ ΡΥΘΜΟ ΡΟΗΣ(Σ.Ε.Ψ.Δ.),ΧΩΡΙΣ ΕΠΑΝΑΧΡΗΣΙΜΟΠΟΙΗΣΗ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ ΚΑΙ Γ)ΣΥΝΔΥΑΣΜΕΝΗ ΜΕΘΟΔΟΣ (Σ.Μ) ΑΠΟΤΕΛΟΥΜΕΝΗ ΑΠΟ Α.Υ.Δ. ΓΙΑ 6 ΩΡΕΣ ΚΑΙ ΣΤΗ ΣΥΝΕΧΕΙΑ,Σ,Ε,Ψ,Δ,ΔΙΑ ΤΗΣ ΠΥΛΑΙΑΣ ΦΛΕΒΑΣ,ΓΙΑ ΑΛΛΕΣ 8 ΩΡΕΣ.ΔΕΚΑ ΕΞΙ ΧΟΙΡΟΙ ΒΑΡΟΥΣ 20-25 KG ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΑΝ ΣΑΝ ΔΟΤΕΣ ΚΑΙ ΑΛΛΟΙ 16 ΙΔΙΟΥ ΜΕΓΕΘΟΥΣ, ΣΑΝ ΛΗΠΤΕΣ.ΤΕΣΣΕΡΑ ΑΠΟ ΤΑ 16 ΗΠΑΤΙΚΑ ΜΟΣΧΕΥΜΑΤΑ ΔΙΑΤΗΡΗΘΗΚΑΝ ΜΕ ΤΗ ΜΕΘΟΔΟ ΤΗΣ Α.Υ.Δ ,ΑΛΛΑ ΤΕΣΣΕΡΑ ΜΕ ΑΥΤΗ ΤΗΣ Σ.Ε.Ψ.Δ. ΚΑΙ ΤΑ ΤΕΛΕΥΤΑΙΑ ΟΚΤΩ ΜΕ ΤΗ Σ.Μ.ΟΛΑ ΤΑ ΜΟΣΧΕΥΜΑΤΑ ΔΙΑΤΗΡΗΘΗΚΑΝ ΓΙΑ 14 ΩΡΕΣ.ΜΕΤΑ ΤΟ ΤΕΛΟΣ ΤΟΥ ΧΡΟΝΟΥ ΔΙΑΤΗΡΗΣΗΣ ΤΑ ΜΟΣΧΕΥΜΑΤΑ ΑΥΤΑ ΜΕΤΑΜΟΣΧΕΥΟΝΤΑΝ ΟΡΘΟΤΟΠΙΚΑ.L-R'S ΔΙΑΛΥΜΑ,4oC ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΕ ΣΑΝ ΔΙΑΛΥΜΑ ΔΙΑΤΗΡΗΣΗΣ ΚΑΙ ΕΓΧΥΣΗΣ.ΤΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΑΥΤΗΣ ΤΗΣ ΜΕΛΕΤΗΣ ΔΕΙΧΝΟΥΝ ΟΤΙ:Α)ΜΕ ΤΗ ΧΡΗΣΗ L-R'S,4C ΣΑΝ ΔΙΑΛΥΜΑ ΔΙΑΤΗΡΗΣΗΣ ΜΠΟΡΕΙ ΝΑ ΕΠΙΤΕΥΧΘΕΙ ΑΣΦΑΛΗΣ ΣΤΑΘΕΡΗ ΥΠΟΘΕΡΜΙΚΗ ΔΙΑΤΗΡΗΣΗ ΤΟΥ ΗΠΑΤΟΣ ΜΕ Α.Υ.Δ. ΓΙΑ 6 ΩΡΕΣ, Β)Η ΣΥΝΕΧΗΣ ΕΓΧΥΣΗ ΔΙΝΕΙ ΣΗΜΑΝΤΙΚΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ,ΟΤΑΝ ΑΥΤΗ ΓΙΝΕΤΑΙ ΜΕ ΧΑΜΗΛΟ ΡΥΘΜΟ ΡΟΗΣ ΚΑΙ ΧΩΡΙΣ ΕΠΑΝΑΧΡΗΣΙΜΟΠΟΙΗΣΗ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ, ΕΠΕΚΤΕΙΝΟΝΤΑΣ ΤΟ ΧΡΟΝΟ ΑΣΦΑΛΟΥΣ ΔΙΑΤΗΡΗΣΗΣ ΣΤΙΣ 14 ΩΡΕΣ, ΚΑΙ Γ)Ο ΣΥΝΔΥΑΣΜΟΣ ΤΩΝ ΔΥΟ ΜΕΘΟΔΩΝ(Α.Υ.Δ ΚΑΙ Σ.Ε.Ψ.Δ) ΑΠΟΤΕΛΕΙ ΜΙΑ ΑΞΙΟΠΙΣΤΗ, ΑΠΛΗ ΚΑΙ ΚΑΤΑΛΛΗΛΗ ΓΙΑ ΜΕΤΑΦΟΡΑ ΜΕΘΟΔΟ ΔΙΑΤΗΡΗΣΗΣ Τ