SummaryBackgroundOxidized cellulose is a well known and widely used surgical hemostat. It is available in many forms, but manufactured using either a nonregenerated or regenerated process.ObjectiveThis study compares the fiber structure, pH in solution, bactericidal effectiveness, and hemostatic effectiveness of an oxidized nonregenerated cellulose (ONRC; Traumastem®) and an oxidized regenerated cellulose (ORC; Surgicel® Original).MethodsIn vitro, fiber structures were compared using scanning electron microscopy, pH of phosphate buffer solution (PBS) and human plasma were measured after each cellulose was submerged, and bactericidal effect was measured by plating each cellulose with four bacteria. In vivo, time to hemostasis and hemostatic success were compared using a general surgery nonheparinized porcine liver abrasion model and a peripheral vascular surgery heparinized leporine femoral vessel bleeding model.ResultsUltrastructure of ONRC fiber is frayed, while ORC is smooth. ORC pH is statistically more acidic than ONRC in PBS, but equal in plasma. No difference in bactericidal effectiveness was observed. In vivo, ONRC provided superior time to hemostasis relative to ORC (211.2 vs 384.6 s, N = 60/group) in the general surgery model; and superior hemostatic success relative to ORC at 30 (60 vs. 15 %; OR: 13.5; 95 % CI: 3.72–49.1, N = 40/group), 60 (85 vs. 37.5 %; OR: 12.3; 95 % CI: 3.66–41.6), and 90 s (97.5 vs 70.0 %; OR: 21.1, 95 % CI: 2.28–195.9) in the peripheral vascular model.ConclusionONRC provides superior hemostasis and equivalent bactericidal effectiveness relative to ORC, which is likely due to its fiber structure than acidity.

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There are currently no physical phantoms available for calibrating in vivo counting devices that represent women with different breast sizes because such phantoms are difficult, time consuming and expensive to fabricate. In this work, a feasible alternative involving computational phantoms was explored. A series of new female voxel phantoms with different breast sizes were developed and ported into a Monte Carlo radiation transport code for performing virtual lung counting efficiency calibrations. The phantoms are based on the RPI adult female phantom, a boundary representation (BREP) model. They were created with novel deformation techniques and then voxelized for the Monte Carlo simulations. Eight models have been selected with cup sizes ranging from AA to G according to brassiere industry standards. Monte Carlo simulations of a lung counting system were performed with these phantoms to study the effect of breast size on lung counting efficiencies, which are needed to determine the activity of a radionuclide deposited in the lung and hence to estimate the resulting dose to the worker. Contamination scenarios involving three different radionuclides, namely Am-241, Cs-137 and Co-60, were considered. The results show that detector efficiencies considerably decrease with increasing breast size, especially for low energy photon emitting radionuclides. When the counting efficiencies of models with cup size AA were compared to those with cup size G, a difference of up to 50% was observed. The detector efficiencies for each radionuclide can be approximated by curve fitting in the total breast mass (polynomial of second order) or the cup size (power).

ReuseItems deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.PHYSICAL REVIEW C 94, 025205 (2016) Determination of the real part of the η ′ -Nb optical potential The excitation function and momentum distribution of η ′ mesons have been measured in photoproduction off 93 Nb in the energy range of 1.2-2.9 GeV. The experiment has been performed with the combined Crystal Barrel and MiniTAPS detector system, using tagged photon beams from the ELSA electron accelerator. Information on the sign and magnitude of the real part of the η ′ -Nb potential has been extracted from a comparison of the data with model calculations. An attractive potential of −(41 ± 10(stat) ± 15(syst)) MeV depth at normal nuclear matter density is deduced within model uncertainties. This value is consistent with the potential depth of −(37 ± 10(stat) ± 10(syst)) MeV obtained in an earlier measurement for a light nucleus (carbon). This relatively shallow η ′ -nucleus potential will make the search for η ′ -nucleus bound states more difficult.