GSH Attenuates Organ Injury and Improves Function after Transplantation of Fatty Livers

Ischemia-reperfusion injury (IRI) is increased after transplantation of steatotic livers. Since those livers are increasingly used for transplantation, protective strategies must be developed. Reactive oxygen species (ROS) play a key role in hepatic IRI. In lean organs, glutathione (GSH) is an efficient scavenger of ROS, diminishing IRI. The aim of this study was to evaluate whether GSH also protects steatotic allografts from IRI following transplantation. Fatty or lean livers were explanted from 10-week-old obese or lean Zucker rats and preserved (obese 4 h, lean 24 h) in hypothermic University of Wisconsin solution. Arterialized liver transplantation was then performed in lean syngeneic Zucker rats. Recipients of fatty livers were treated with GSH (200 mu mol/h/kg) or saline during reperfusion (2 h, n = 5). Parameters of hepatocellular damage and bile flow were measured. Transplantation of steatotic livers enhanced early reperfusion injury compared to lean organs as measured by increased aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase plasma levels. Bile flow was also reduced in steatotic grafts. Intravenous administration of GSH effectively decreased liver damage in fatty allografts and resulted in improved bile flow. Intravenous application of GSH effectively reduces early IRI in steatotic allografts and improves recovery of these marginal donor organs following transplantation. Copyright (C) 2010 S. Karger AG, Base

Influence of Mandrel s Surface on the Mechanical Properties of Joints Produced by Electromagnetic Compression

Electromagnetic compression of tubular profiles with high electrical conductivity is an innovative joining process for the manufacturing of lightweight structures. Taking conventional interference fits into account, the contact area s influence on the joint s quality seems to be of significance, as e.g. the contact area and the friction coefficient between the joining partners determine an allowed axial load or torsional momentum proportionally. Therefore, different contact area surfaces were prepared by shot peening and different machining operations and strategies. The mandrel s surfaces were prepared by shot peening with glass beads and Al2O3 particles. Alternatively, preparation was done using simultaneous five axis milling, because potential joining partners in lightweight frame structures within the Transregional Collaborative Research Centre SFB/TR10 would be manufactured similarly. After that, the manufactured surfaces were characterized by measuring the surface roughness and using confocal whitelight microscopy. After joining by electromagnetic compression, the influence of different mandrel s surface conditions on the joint s mechanical properties were analyzed by tensile tests. Finally, conclusions and design rules for the manufacturing of joints by electromagnetic compression are given

Liver resection or combined chemoembolization and radiofrequency ablation improve survival in patients with hepatocellular carcinoma

Background/ Aims: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). Methods: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM- HCC). Results: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection ( n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation ( RFA) ( n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p <= 0.004) improved survival time in VISUM stage 1 - 2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. Conclusion: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC

From Enterprise Modelling to Architecture-Driven IT Management - A Design Theory

Enterprise architectures (EA) are considered promising approaches to reduce the complexities of growing information technology (IT) environments while keeping pace with an ever-changing business environment. However, the implementation of enterprise architecture management (EAM) has proven difficult in practice. Many EAM initiatives face severe challenges, as demonstrated by the low usage level of enterprise architecture documentation and enterprise architects' lack of authority regarding enforcing EAM standards and principles. These challenges motivate our research. Based on three field studies, we first analyze EAM implementation issues that arise when EAM is started as a dedicated and isolated initiative. Following a design-oriented paradigm, we then suggest a design theory for architecture-driven IT management (ADRIMA) that may guide organizations to successfully implement EAM. This theory summarizes prescriptive knowledge related to embedding EAM practices, artefacts and roles in the existing IT management processes and organization

Improving the Realization of IT Demands: A Design Theory for End-to-End Demand Management

With the growing penetration of IT and its critical role within organizations, the number of requests for IT services and solutions is steadily increasing. However, many companies lack a consolidated view of all these requests or demands. They also struggle to track and report on the conversion of demands into IT solutions. Given the importance of managing demands for effective IT landscape development and for satisfying business users, our research aims at developing a design theory for an end-to-end demand management process. It is based on an extensive action design research study involving experts from 13 companies. The main contribution is a set of seven principles that guide the effective design of IT demand management. By focusing on the process from the emergent demand to the ready-to-use solution, our work closes a gap in existing research which is fragmented into requirements engineering, project portfolio management, and IT governance streams

Damage Mechanisms of Cast Al-Si-Mg-Alloys Under Superimposed Thermal-mechanical Fatigue Loading

Out-of-phase thermal-mechanical fatigue (TMF) tests with superimposed higher frequency mechanical fatigue (HCF) loading were performed at three cast Al-Si cylinder head alloys. All materials show for maximum temperatures of the TMF cycle between 200 and 250 degrees C a threshold of the amplitude of the superimposed HCF loading below of which the number of TMF cycles to failure is not significantly affected by the superimposed HCF loading. Above this threshold the TMF life shows a strong decrease with increasing HCF loading. Extensive microscopic analyses revealed that independent from the HCF loading first cracks are initiated at eutectic Si-particles detached from the surrounding alpha-Al matrix. Crack propagation occurs at small HCF amplitudes along the eutectic regions. At higher superimposed HCF loadings an accelerated crack propagation along slip bands within the alpha-Al matrix is observed.(c) 2007 Elsevier B.V. All rights reserved

Description of short time phase transformations during the heating of steels based on high-rate experimental data

During surface hardening of steels like laser hardening, rapid thermal changes are imposed to the material. The modelling of these hardening processes allows the determination of time-dependent temperature fields and phase transformations within the affected zones. While there are many investigations on the transformation behaviour during cooling, there is a lack of data concerning the transformation during heating at very high heating rates. Therefore, experiments simulating the fast temperature changes are necessary to implement the effects of short time phase transformation during hardening into simulation. In this paper the effect of heating rates up to 10000 K/s on the austenitizing behaviour of the steel AISI 4140 (German grade 42CrMo4) are presented and described using an Avrami-function. The results obtained are summarized in time-temperature-transformation diagrams for continuous heating and isothermal time-temperature-transformation diagrams which may be used as input data for the simulation