Osteogenic cell response to 3-D hydroxyapatite scaffolds developed via replication of natural marine sponges

Bone tissue engineering may provide an alternative to autograft, however scaffold optimisation is required to maximize bone ingrowth. In designing scaffolds, pore architecture is important and there is evidence that cells prefer a degree of non-uniformity. The aim of this study was to compare scaffolds derived from a natural porous marine sponge (Spongia agaricina) with unique architecture to those derived from a synthetic polyurethane foam. Hydroxyapatite scaffolds of 1 cm(3) were prepared via ceramic infiltration of a marine sponge and a polyurethane (PU) foam. Human foetal osteoblasts (hFOB) were seeded at 1 × 10(5) cells/scaffold for up to 14 days. Cytotoxicity, cell number, morphology and differentiation were investigated. PU-derived scaffolds had 84–91 % porosity and 99.99 % pore interconnectivity. In comparison marine sponge-derived scaffolds had 56–61 % porosity and 99.9 % pore interconnectivity. hFOB studies showed that a greater number of cells were found on marine sponge-derived scaffolds at than on the PU scaffold but there was no significant difference in cell differentiation. X-ray diffraction and inductively coupled plasma mass spectrometry showed that Si ions were released from the marine-derived scaffold. In summary, three dimensional porous constructs have been manufactured that support cell attachment, proliferation and differentiation but significantly more cells were seen on marine-derived scaffolds. This could be due both to the chemistry and pore architecture of the scaffolds with an additional biological stimulus from presence of Si ions. Further in vivo tests in orthotopic models are required but this marine-derived scaffold shows promise for applications in bone tissue engineering

Selection criteria of Zebrafish male donors for sperm cryopreservation

Selection criteria for sperm cryopreservation are highly relevant in zebrafish since sperm quality is particularly variable in this species. Successful cryopreservation depends on high-quality sperm, which can only be ensured by the selection of breeders. Consequently, male selection and management are a priority to improve cryopreservation, and therefore, this study aimed to characterize optimal age and sperm collection frequency in zebrafish. For this purpose, males from wild type (AB) and from a transgenic line [Tg(runx2:eGFP)] were sampled at 6, 8, 12, and 14 months. For each age, sperm were collected at time 0 followed by samplings at 2, 7, and 14 days of rest. Sperm quality was assessed according to motility and membrane viability parameters. Quality assessment showed that Tg(runx2:eGFP) displayed significantly higher motility than AB and younger males showed higher motility in both lines. Sperm collection frequency affected membrane viability. While AB fish recovered sperm viability after 14 days of rest, Tg(runx2:eGFP) could not recover. Consequently, it may be important to study the sperm quality of each zebrafish line before sperm cryopreservation. Taking into consideration the results achieved in both lines, sperm collection should be performed between 6 and 8 months of age with a minimum collection interval of 14 days.N730984, EBB-EAPA_501/2016, PEst-C/MAR/LA0015/2011info:eu-repo/semantics/publishedVersio

Damage function for historic paper. Part II: Wear and tear

Background: As a result of use of library and archival documents, defined as reading with handling in the context of general access, mechanical degradation (wear and tear) accumulates. In contrast to chemical degradation of paper, the accumulation of wear and tear is less well studied. Previous work explored the threshold of mechanical degradation at which a paper document is no longer considered to be fit for the purpose of use by a reader, while in this paper we explore the rate of accumulation of such damage in the context of object handling. Results: The degree of polymerisation (DP) of historic paper of European origin from mid-19th–mid-20th Century was shown to affect the rate of accumulation of wear and tear. While at DP > 800, this accumulation no longer depends on the number of handlings (the process is random), a wear-out function could be developed for documents with DP between 300 and 800. For objects with DP < 300, one large missing piece (i.e. such that contains text) developed on average with each instance of handling, which is why we propose this DP value as a threshold value for safe handling. Conclusions: The developed model of accumulation of large missing pieces per number of handlings of a document depending on DP, enables us to calculate the time required for an object to become unfit for use by readers in the context of general access. In the context of the average frequency of document use at The UK National Archives (Kew), this period is 60 years for the category of papers with DP 300, and 450 years for papers with DP 500. At higher DP values, this period of time increases beyond the long-term planning horizon of 500 years, leading to the conclusion that for such papers, accumulation of wear and tear is not a significant collection management concern

A comparison of policy and direct practice stakeholder perceptions of factors affecting evidence-based practice implementation using concept mapping

<p>Abstract</p> <p>Background</p> <p>The goal of this study was to assess potential differences between administrators/policymakers and those involved in direct practice regarding factors believed to be barriers or facilitating factors to evidence-based practice (EBP) implementation in a large public mental health service system in the United States.</p> <p>Methods</p> <p>Participants included mental health system county officials, agency directors, program managers, clinical staff, administrative staff, and consumers. As part of concept mapping procedures, brainstorming groups were conducted with each target group to identify specific factors believed to be barriers or facilitating factors to EBP implementation in a large public mental health system. Statements were sorted by similarity and rated by each participant in regard to their perceived importance and changeability. Multidimensional scaling, cluster analysis, descriptive statistics and <it>t</it>-tests were used to analyze the data.</p> <p>Results</p> <p>A total of 105 statements were distilled into 14 clusters using concept-mapping procedures. Perceptions of importance of factors affecting EBP implementation varied between the two groups, with those involved in direct practice assigning significantly higher ratings to the importance of Clinical Perceptions and the impact of EBP implementation on clinical practice. Consistent with previous studies, financial concerns (costs, funding) were rated among the most important and least likely to change by both groups.</p> <p>Conclusions</p> <p>EBP implementation is a complex process, and different stakeholders may hold different opinions regarding the relative importance of the impact of EBP implementation. Implementation efforts must include input from stakeholders at multiple levels to bring divergent and convergent perspectives to light.</p

Should Research Ethics Encourage the Production of Cost-Effective Interventions?

This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs

Arming the Outlaws: On the Moral Limits of the Arms Trade

There is a general presumption against arming outlaw states. But can that presumption sometimes be overturned? The argument considered here maintains that outlaw states can have legitimate security interests, and that transferring weapons to these states can be an appropriate way of promoting those interests. Weapons enable governments to engage in wrongful oppression and aggression, but they also enable them to fend off predators in a manner that can be beneficial to their citizens. It clearly does not follow from the fact that a state is oppressive or aggressive that it will never be a victim of wrongful aggression itself, and while an outlaw state’s primary aim in repelling such aggression will often be the preservation of its own power, its defensive manoeuvres will sometimes also serve its citizens’ interests. In short, supplying weapons to outlaw states may sometimes contribute to the protection of innocents

Evidence-based effect size estimation:An illustration using the case of acupuncture for cancer-related fatigue

<p>Abstract</p> <p>Background</p> <p>Estimating a realistic effect size is an important issue in the planning of clinical studies of complementary and alternative medicine therapies. When a minimally important difference is not available, researchers may estimate effect size using the published literature. This evidence-based effect size estimation may be used to produce a range of empirically-informed effect size and consequent sample size estimates. We provide an illustration of deriving plausible effect size ranges for a study of acupuncture in the relief of post-chemotherapy fatigue in breast cancer patients.</p> <p>Methods</p> <p>A PubMed search identified three uncontrolled studies reporting the effect of acupuncture in relieving fatigue. A separate search identified five randomized controlled trials (RCTs) with a wait-list control of breast cancer patients receiving standard care that reported data on fatigue. We use these published data to produce best, average, and worst-case effect size estimates and related sample size estimates for a trial of acupuncture in the relief of cancer-related fatigue relative to a wait-list control receiving standard care.</p> <p>Results</p> <p>Use of evidence-based effect size estimation to calculate sample size requirements for a study of acupuncture in relieving fatigue in breast cancer survivors relative to a wait-list control receiving standard care suggests that an adequately-powered phase III randomized controlled trial comprised of two arms would require at least 101 subjects (52 per arm) if a strong effect is assumed for acupuncture and 235 (118 per arm) if a moderate effect is assumed.</p> <p>Conclusion</p> <p>Evidence-based effect size estimation helps justify assumptions in light of empirical evidence and can lead to more realistic sample size calculations, an outcome that would be of great benefit for the field of complementary and alternative medicine.</p

Study of Zγ events and limits on anomalous ZZγ and Zγγ couplings in pp̄ collisions at s=1.96TeV

We present a measurement of the Zγ production cross section and limits on anomalous ZZγ and Zγγ couplings for form-factor scales of Λ=750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eeγ (μμγ) final state using 320(290)pb-1 of pp̄ collisions at s=1.96TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h10,30Z|<0.23, |h20,40Z|<0.020, |h10,30γ|<0.23, and |h20,40γ|<0.019 for Λ=1000GeV. © 2005 The American Physical Society

What counts as reliable evidence for public health policy: the case of circumcision for preventing HIV infection

<p>Abstract</p> <p>Background</p> <p>There is an ongoing controversy over the relative merits of randomized controlled trials (RCTs) and non-randomized observational studies in assessing efficacy and guiding policy. In this paper we examine male circumcision to prevent HIV infection as a case study that can illuminate the appropriate role of different types of evidence for public health interventions.</p> <p>Discussion</p> <p>Based on an analysis of two Cochrane reviews, one published in 2003 before the results of three RCTs, and one in 2009, we argue that if we rely solely on evidence from RCTs and exclude evidence from well-designed non-randomized studies, we limit our ability to provide sound public health recommendations. Furthermore, the bias in favor of RCT evidence has delayed research on policy relevant issues.</p> <p>Summary</p> <p>This case study of circumcision and HIV prevention demonstrates that if we rely solely on evidence from RCTs and exclude evidence from well-designed non-randomized studies, we limit our ability to provide sound public health recommendations.</p