Human platelet concentrates treated with microbicidal 405 nm light retain hemostasis activity

Chemical and UV light-based pathogen reduction technologies are currently in use for human platelet concentrates (PCs) to enhance safety from transfusion-transmitted infections. Relative to UV light, 405 nm violet-blue light in the visible spectrum is known to be less harmful. Hence, in this report for the first time, we have assessed the global hemostasis activity of PCs stored in plasma and the activities of six plasma coagulation factors (CFs) as a measure of in vitro hemostatic activity following exposure to the microbicidal 405 nm light. Apheresis PC samples collected from each screened human donor (n = 22) were used for testing of PCs and platelet poor plasma (PPP). Both PCs and PPPs were treated for 5 h with 405 nm light to achieve a previously established microbicidal light dose of 270 J/cm2. Activated partial thromboplastin time and prothrombin time-based potency assays using a coagulation analyzer and hemostatic capacity via Thromboelastography were analyzed. Thromboelastography analysis of the light-treated PCs and plasma present in the PCs showed little difference between the treated and untreated samples. Further, plasma present in the PCs during the light treatment demonstrated a better stability in potency assays for several coagulation factors compared to the plasma alone prepared from PCs first and subjected to the light treatment separately. Overall, PCs stored in plasma treated with 405 nm violet-blue light retain activity for hemostasis

Natural vibration analysis of tensioned risers by segmentation method

The natural vibration of deepwater tensioned uniform risers is analysed. The riser is considered as both a cable and a beam due to the fairly weak flexural stiffness. The exact and asymptotic solutions of the cable differential equation are presented. The beam vibration is determined by modifying the cable solution for each halfwave of the natural mode which are called segments . The simplified analytical procedure is verified by the finite element method. Very valuable conclusions are drawn on riser dynamic behaviour in the lower and higher frequency domain. The main application of the study is the assessment of forced vortexinduced riser vibration

Review of the uncertainties associated to hull girder hydroelastic response and wave load predictions

This paper reviews the importance of uncertainties in hull girder loads influenced by flexible fluid structure interactions. The focus is on developments in the field of hydroelastic modelling, simulation and model tests of practical relevance to the prediction hull girder wave load predictions and their validation. It is concluded that whereas hydroelastic methods for use in design development and assessment become increasingly useful, challenges in realizing and modelling uncertainties can be attributed to: (1) the limitations of numerical methods to suitably model nonlinearities; (2) the ambiguity of model tests; and (3) the systematic use of data emerging from computational, model- or full-scale methods. An approach is recommended to assess the uncertainty in the hydroelastic responses to wave loading and an example is provided to demonstrate the application of the procedure.Peer reviewe

Report of Technical Committee V.6 of ISSC2009: Condition Assessment of Aging Ships and Offshore Structures

ISSC Committee mandate: Concern for the assessment of the serviceability and safety of aging ships and offshore installations. This shall include reliability-based assessment of age-related structural degradation, inspection, maintenance and repair. Consideration shall be given to costbenefit and risk-based decision procedures