Systematic review and meta-analysis of peak wall stress and peak wall rupture index in ruptured and asymptomatic intact abdominal aortic aneurysms

BACKGROUND: Prior studies have suggested aortic peak wall stress (PWS) and peak wall rupture index (PWRI) can estimate the rupture risk of an abdominal aortic aneurysm (AAA), but whether these measurements have independent predictive ability over assessing AAA diameter alone is unclear. The aim of this systematic review was to compare PWS and PWRI in participants with ruptured and asymptomatic intact AAAs of similar diameter. METHODS AND RESULTS: Web of Science, Scopus, Medline, and The Cochrane Library were systematically searched to identify studies assessing PWS and PWRI in ruptured and asymptomatic intact AAAs of similar diameter. Random-effects meta-analyses were performed using inverse variance-weighted methods. Leave-one-out sensitivity analyses were conducted to assess the robustness of findings. Risk of bias was assessed using a modification of the Newcastle-Ottawa scale and standard quality assessment criteria for evaluating primary research papers. Seven case-control studies involving 309 participants were included. Meta-analyses suggested that PWRI (standardized mean difference, 0.42; 95% CI, 0.14–0.70; P=0.004) but not PWS (standardized mean difference, 0.13; 95% CI, −0.18 to 0.44; P=0.418) was greater in ruptured than intact AAAs. Sensitivity analyses suggested that the findings were not dependent on the inclusion of any single study. The included studies were assessed to have a medium to high risk of bias. CONCLUSIONS: Based on limited evidence, this study suggested that PWRI, but not PWS, is greater in ruptured than asymptomatic intact AAAs of similar maximum aortic diameter

Microstructural quantification of collagen fiber orientations and its integration in constitutive modeling of the porcine carotid artery

Background Mechanical characteristics of vascular tissue may play a role in different arterial pathologies, which, amongst others, requires robust constitutive descriptions to capture the vessel wall’s anisotropic and non-linear properties.Specifically, the complex 3D network of collagen and its interaction with other structural elements has a dominating effect of arterial properties at higher stress levels.The aim of this study is to collect quantitative collagen organization as well as mechanical properties to facilitate structural constitutive models for the porcine carotid artery.This helps the understanding of the mechanics of swine carotid arteries, being a standard in clinical hypothesis testing, in endovascular preclinical trials for example. Method Porcine common carotid arteries (n = 10) were harvested and used to (i) characterize the collagen fiber organization with polarized light microscopy, and (ii) the biaxial mechanical properties by inflation testing.The collagen organization was quantified by the Bingham orientation density function (ODF), which in turn was integrated in a structural constitutive model of the vessel wall.A one-layered and thick-walled model was used to estimate mechanical constitutive parameters by least-square fitting the recorded in vitro inflation test results.Finally, uniaxial data published elsewhere were used to validate the mean collagen organization described by the Bingham ODF. Results Thick collagen fibers, i.e.the most mechanically relevant structure, in the common carotid artery are dispersed around the circumferential direction.In addition, almost all samples showed two distinct families of collagen fibers at different elevation, but not azimuthal, angles.Collagen fiber organization could be accurately represented by the Bingham ODF (¿1,2,3=[13.5,0.0,25.2] and ¿1,2,3=[14.7,0.0,26.6]; average error of about 5%), and their integration into a structural constitutive model captured the inflation characteristics of individual carotid artery samples.Specifically, only four mechanical parameters were required to reasonably (average error from 14% to 38%) cover the experimental data over a wide range of axial and circumferential stretches.However, it was critical to account for fibrilar links between thick collagen fibers.Finally, the mean Bingham ODF provide also good approximation to uniaxial experimental data. Conclusions The applied structural constitutive model, based on individually measured collagen orientation densities, was able to capture the biaxial properties of the common carotid artery. Since the model required coupling amongst thick collagen fibers, the collagen fiber orientations measured from polarized light microscopy, alone, seem to be insufficient structural information. Alternatively, a larger dispersion of collagen fiber orientations, that is likely to arise from analyzing larger wall sections, could have had a similar effect, i.e. could have avoided coupling amongst thick collagen fibers.Peer ReviewedPostprint (author's final draft

Holzreste von spätglazialen Kiefern aus der tiefgründigen und tonreichen Permanentrutschung ‚Spiegelberg’, Kanton Schwyz (Schweiz)

Die Hauptstrasse Nr. 8 zwischen Schwyz und Sattel verläuft durch aktive und tiefgründige Permanentrutschungen. Im lehmigen, matrix-gestützten Gehängeschutt der Rutschung ‚Spiegelberg’ wurde zwischen 1979–81 die Gütschbrücke erstellt (LK: 690.314/211.943; 670 m ü.M.) und unter Anwendung von Gründungsschutzschächten im unterlagernden Fels fundiert. Beim Aushub des Schutzschachtes für den Pfeiler WL-Nord wurden in der Tiefe von 25 m bzw. 38 m unter Oberkante Terrain zwei Nadelbaumfragmente gefunden. Letzterer Holzfund lag wenige Meter über der Felsoberfläche. Die 14C-Altersdatierung der Holzfunde (beide Pinus sylvestris) ergaben kalibrierte Altersspannen zwischen 11.690–11.270 cal. a BP (2s) am Übergang vom Grönland Stadial 1 (GS-1; ‚Jüngere Dryas’) zum Holozän bzw. 13.830–13.640 cal. a BP (2s) zu Beginn der spätglazialen Wärmeschwankung GI-1c (Grönland Interstadial 1c; ‚Allerød’). Die vorliegenden Daten zeigen, dass die Hanginstabilitäten bei ‚Spiegelberg’ nach dem Zerfall des letzteiszeitlichen Muota/Reussgletschers zu Beginn des Spätglazials eingesetzt haben mussten, und die Waldkiefer schon kurz nach den Kälterückschlägen des GI-1d (‚Aegelsee-Schwankung’) bzw. des GS-1 am nördlichen Alpenrand präsent war.researc

Association between aortic peak wall stress and rupture index with abdominal aortic aneurysm–related events

Objective: The aim of this study was to assess whether aortic peak wall stress (PWS) and peak wall rupture index (PWRI) were associated with the risk of abdominal aortic aneurysm (AAA) rupture or repair (defined as AAA events) among participants with small AAAs. Methods: PWS and PWRI were estimated from computed tomography angiography (CTA) scans of 210 participants with small AAAs (≥ 30 and ≤ 50 mm) prospectively recruited between 2002 and 2016 from two existing databases. Participants were followed for a median of 2.0 (inter-quartile range 1.9, 2.8) years to record the incidence of AAA events. The associations between PWS and PWRI with AAA events were assessed using Cox proportional hazard analyses. The ability of PWS and PWRI to reclassify the risk of AAA events compared to the initial AAA diameter was examined using net reclassification index (NRI) and classification and regression tree (CART) analysis. Results: After adjusting for other risk factors, one standard deviation increase in PWS (hazard ratio, HR, 1.56, 95% confidence intervals, CI 1.19, 2.06; p = 0.001) and PWRI (HR 1.74, 95% CI 1.29, 2.34; p 0.562. PWRI, but not PWS, significantly improved the classification of risk of AAA events compared to the initial AAA diameter alone. Conclusion: PWS and PWRI predicted the risk of AAA events but only PWRI significantly improved the risk stratification compared to aortic diameter alone. Key Points: • Aortic diameter is an imperfect measure of abdominal aortic aneurysm (AAA) rupture risk. • This observational study of 210 participants found that peak wall stress (PWS) and peak wall rupture index (PWRI) predicted the risk of aortic rupture or AAA repair. • PWRI, but not PWS, significantly improved the risk stratification for AAA events compared to aortic diameter alone

Evaluation of pedagogical-therapeutic measures in practice. Insight into the SCAP project

Das SCAP stellt im luxemburgischen Bildungssystem ein pädagogisch-therapeutisches Angebot im obligatorischen Bildungssystem zur Verfügung. SCAP steht für «Service de Consultation et d’Aide pour troubles de l’Attention, de la Perception et du développement Psychomoteur» - zu Deutsch: Beratungs- und Unterstützungsstelle bei Störungen der Aufmerksamkeit, der Wahrnehmung und der psychomotorischen Entwicklung. Zielgruppe sind Kinder und Jugendliche zwischen 4 und 18 Jahren mit Aufmerksamkeitsschwierigkeiten, Wahrnehmungsschwierigkeiten oder psychomotorischen Schwierigkeiten. Das SCAP intendiert für eine allgemeine Qualitätsverbesserung das Konzept der Einrichtung hinsichtlich des pädagogisch-therapeutischen Angebots zu überarbeiten. Um diese Anpassung datenbasiert vorzunehmen, soll zunächst die aktuelle Arbeit evaluiert werden, was die Möglichkeit eröffnet, die Wirksamkeit und Nachhaltigkeit von psychomotorischen und weiteren pädagogisch-therapeutischen Maßnahmen im Feld nachzuzeichnen. Der Beitrag stellt das Projektdesign vor. Zudem wird skizziert, welche Maßnahmen auf Basis welcher Indikation vom SCAP geplant und eingesetzt werden, sowie welche Entwicklungen die Kinder während der Wartezeit vor Therapiebeginn im SCAP durchlaufen. (DIPF/Orig.)The SCAP (Service de Consultation et d’Aide pour troubles de l’Attention, de la Perception et du développement Psychomoteur) provides a pedagogical-therapeutic offering within the Luxembourgish education system. SCAP translates to “Consultation and Support Service for Attention, Perception, and Psychomotor Development Disorders.” The target audience consists of children and adolescents aged 4 to 18 with difficulties in attention, perception, or psychomotor development. SCAP aims to adapt and revise the concept of the facility in terms of its pedagogical-therapeutic offerings for a general improvement in quality. To make data-driven adjustments, the current work will be evaluated initially, providing the opportunity to trace the effectiveness and sustainability of psychomotor and other pedagogical-therapeutic measures in the field. This contribution introduces the project design and outlines the measures planned and implemented by SCAP based on specific indications. Additionally, it highlights the developments that children undergo during the waiting period before therapy begins at SCAP. (DIPF/Orig.

Osteoporosis case finding in the general practice: phalangeal radiographic absorptiometry with and without risk factors for osteoporosis to select postmenopausal women eligible for lumbar spine and hip densitometry

Mass screening for osteoporosis using DXA measurements at the spine and hip is presently not recommended by health authorities. Instead, risk factor questionnaires and peripheral bone measurements may facilitate the selection of women eligible for axial bone densitometry. The aim of this study was to validate a case finding strategy for postmenopausal women who would benefit most from subsequent DXA measurement by using phalangeal radiographic absorptiometry (RA) alone or in combination with risk factors in a general practice setting. The sensitivity and specificity of this strategy in detecting osteoporosis (T-score ≤2.5SD at the spine and/or the hip) were compared with those of the current reimbursement criteria for DXA measurements in Switzerland. Four hundred and twenty-three postmenopausal women with one or more risk factors for osteoporosis were recruited by 90 primary care physicians who also performed the phalangeal RA measurements. All women underwent subsequent DXA measurement of the spine and the hip at the Osteoporosis Policlinic of the University Hospital of Berne. They were allocated to one of two groups depending on whether they matched with the Swiss reimbursement conditions for DXA measurement or not. Logistic regression models were used to predict the likelihood of osteoporosis versus "no osteoporosis” and to derive ROC curves for the various strategies. Differences in the areas under the ROC curves (AUC) were tested for significance. In women lacking reimbursement criteria, RA achieved a significantly larger AUC (0.81; 95% CI 0.72-0.89) than the risk factors associated with patients' age, height and weight (0.71; 95% C.I. 0.62-0.80). Furthermore, in this study, RA provided a better sensitivity and specificity in identifying women with underlying osteoporosis than the currently accepted criteria for reimbursement of DXA measurement. In the Swiss environment, RA is a valid case finding tool for patients with risk factors for osteoporosis, especially for those who do not qualify for DXA reimbursemen

The LEAF Platform: Incremental Enhancements for the J2EE

LEAF, the Lean and Extensible Architectural Framework, is an enhancement wrapper for J2EE implementations. Basically, LEAF fixes some identified J2EE issues and extends, as well as simplifies, the use of the J2EE by providing several incremental improvements. These improvements are seamlessly integrated, include an additional component type, allow the same interfaces for local and remote service implementations, offer better J2EE implementation compatibility and ORB interceptors, and encompass several new technical services. This paper explains the need for LEAF through a diagnosis of the J2EE, presents the fundamental concepts underlying LEAF, overviews its implementation, reports on field experiences from using it in a number of commercial projects, and points out some interesting tradeoffs in using the J2EE with and without LEAF

Betonieren unter Verkehr: Untersuchung der Auswirkungen von Erschütterungen auf jungen Beton

Im vorgestellten Beitrag wird der Einfluss von Erschütterungen auf den jungen Beton systematisch und anhand von realistischen Versuchen an Kleinkörpern aus unbewehrtem und bewehrtem Beton behandelt. Die kontrollierte dynamische Anregung erfolgt künstlich mit dem AIT-Schwingungsgenerator. Die Proben (zwei verschiedene Betonsorten: „Standard-Brückenbeton“ B3-C30/37 und „Randbalkenbeton“ B7-C25/30) werden während der Erhärtungsphase systematisch mit harmonischen als auch mit realen verkehrsinduzierten Brückenschwingungsverläufen beaufschlagt. Variiert werden Intensitäten und Frequenzgehalt sowie Signalform. Im Anschluss werden die Materialparameter bestimmt und mit ruhend gelagerten Referenzköpern verglichen. Erste Ergebnisse zeigen, dass die mechanischen Eigenschaften Druckfestigkeit und E-Modul wenig oder nur gering beeinflusst werden. Dauerhaftigkeitstests und Untersuchungen am Mikrogefüge dienen dazu, Fehler, Risse und Veränderungen im Gefüge zu identifizieren und werden im laufenden Forschungsprojekt noch weiter durchgeführt. Auswirkungen auf den Verbund zwischen Beton und Bewehrung werden durch Auszugversuche analysiert. Bei diesen Versuchen wurden bei größeren Relativbewegungen zwischen Beton und Bewehrungsstab Abnahmen der mittleren Verbundfestigkeit beobachtet. Bei geringeren Relativverschiebungen (Amplituden von ca. 0,14 mm bei Dauerverkehr) konnte die Verbundfestigkeit hingegen sogar gesteigert werden

GEREJA KRISTEN JAWA UNGARAN

Tugas Akhir ini dilatarbelakangi oleh kebutuhan jemaat Gereja Kristen Jawa Ungaran di dalam melaksanakan ibadah rutin dan pelayananan gereja. Permasalahan yang diangkat untuk dicari solusi desainnya adalah sebagai berikut : 1) Berapa besaran ruang yang diperlukan agar kegiatan ibadah dan pelayanan jemaat Gereja Kristen Jawa Ungaran dapat terfasilitasi, 2) Apa standar-standar yang harus dipenuhi di dalam menentukan ruang ibadah dan fasilitas pelayanan di Gereja Kristen Jawa Ungaran, 3) Bagaimana Gereja Kristen Jawa Ungaran dapat menerapkan arsitektur Jawa sebagai perwujudan komunitas jemaat Kristen Jawa di dalam gereja. Penekanan desain pada Gereja Kristen Jawa Ungaran ini adalah arsitektur yang bernafaskan kebudayaan Jawa. Gereja dengan arsitektur kebudayaan Jawa memberikan identitas khusus pada Gereja Kristen Jawa, membedakan gereja ini dengan gereja-gereja lain di kota Ungaran, serta memberikan suasana yang cocok dengan ibadah jemaat Gereja Kristen Jawa Ungaran. Kajian diawali dengan mempelajari pengertian dari agama Kristen, pengertian gereja Kristen, sejarah Gereja Kristen Jawa, pelaku dan pelayanan liturgi gereja, dan istilah-istilah yang sering digunakan di dalam gereja. Setelah itu dilakukan pendataan standar-standar di dalam membangun sebuah gereja. Dilakukan juga tinjauan mengenai lokasi di Ungaran menurut karakter geografis dan budayanya. Menggabungkan antara budaya Jawa dengan nilai kekristenan tetapi tetap mampu memberikan solusi dalam permasalahan kebutuhan jemaat yang ada merupakan tantangan tersendiri. Akhirnya, seluruh kajian dituangkan dalam bentuk program ruang dan konsep-konsep perancangan yang diaplikasikan ke dalam desain yang dipresentasikan ke dalam bentuk gambar-gambar arsitektur