Development of calcium phosphate cement for the augmentation of traumatically fractured porcine specimens using vertebroplasty

AbstractThe study aim was to develop and apply an experimental technique to determine the biomechanical effect of polymethylmethacrylate (PMMA) and calcium phosphate (CaP) cement on the stiffness and strength of augmented vertebrae following traumatic fracture. Twelve burst type fractures were generated in porcine three-vertebra segments. The specimens were randomly split into two groups (n=6), imaged using microCT and tested under axial loading. The two groups of fractured specimens underwent a vertebroplasty procedure, one group was augmented with CaP cement designed and developed at Queen's University Belfast. The other group was augmented with PMMA cement (WHW Plastics, Hull, UK). The specimens were imaged and re-tested . An intact single vertebra specimen group (n=12) was also imaged and tested under axial loading. A significant decrease (p<0.01) was found between the stiffness of the fractured and intact groups, demonstrating that the fractures generated were sufficiently severe, to adversely affect mechanical behaviour. Significant increase (p<0.01) in failure load was found for the specimen group augmented with the PMMA cement compared to the pre-augmentation group, conversely, no significant increase (p<0.01) was found in the failure load of the specimens augmented with CaP cement, this is attributed to the significantly (p<0.05) lower volume of CaP cement that was successfully injected into the fracture, compared to the PMMA cement. The effect of the percentage of cement fracture fill, cement modulus on the specimen stiffness and ultimate failure load could be investigated further by using the methods developed within this study to test a more injectable CaP cement

The impact of non-alcoholic fatty liver disease and liver fibrosis on adverse clinical outcomes and mortality in patients with chronic kidney disease: a prospective cohort study using the UK Biobank

Abstract Background Chronic kidney disease (CKD) and non-alcoholic fatty liver disease (NAFLD) frequently co-exist. We assess the impact of having NAFLD on adverse clinical outcomes and all-cause mortality for people with CKD. Methods A total of 18,073 UK Biobank participants identified to have CKD (eGFR &lt; 60 ml/min/1.73 m2 or albuminuria &gt; 3 mg/mmol) were prospectively followed up by electronic linkage to hospital and death records. Cox-regression estimated the hazard ratios (HR) associated with having NAFLD (elevated hepatic steatosis index or ICD-code) and NAFLD fibrosis (elevated fibrosis-4 (FIB-4) score or NAFLD fibrosis score (NFS)) on cardiovascular events (CVE), progression to end-stage renal disease (ESRD) and all-cause mortality. Results 56.2% of individuals with CKD had NAFLD at baseline, and 3.0% and 7.7% had NAFLD fibrosis according to a FIB-4 &gt; 2.67 and NFS ≥ 0.676, respectively. The median follow-up was 13 years. In univariate analysis, NAFLD was associated with an increased risk of CVE (HR 1.49 [1.38–1.60]), all-cause mortality (HR 1.22 [1.14–1.31]) and ESRD (HR 1.26 [1.02–1.54]). Following multivariable adjustment, NAFLD remained an independent risk factor for CVE overall (HR 1.20 [1.11–1.30], p &lt; 0.0001), but not ACM or ESRD. In univariate analysis, elevated NFS and FIB-4 scores were associated with increased risk of CVE (HR 2.42 [2.09–2.80] and 1.64 [1.30–2.08]) and all-cause mortality (HR 2.82 [2.48–3.21] and 1.82 [1.47–2.24]); the NFS score was also associated with ESRD (HR 5.15 [3.52–7.52]). Following full adjustment, the NFS remained associated with an increased incidence of CVE (HR 1.19 [1.01–1.40]) and all-cause mortality (HR 1.31 [1.13–1.52]). Conclusions In people with CKD, NAFLD is associated with an increased risk of CVE, and the NAFLD fibrosis score is associated with an elevated risk of CVE and worse survival. </jats:sec

Col-OSSOS: The Distribution of Surface Classes in Neptune's Resonances

The distribution of surface classes of resonant trans-Neptunian objects (TNOs) provides constraints on the protoplanetesimal disk and giant planet migration. To better understand the surfaces of TNOs, the Colours of the Outer Solar System Origins Survey (Col-OSSOS) acquired multi-band photometry of 102 TNOs, and found that the surfaces of TNOs can be well described by two surface classifications, BrightIR and FaintIR. These classifications both include optically red members and are differentiated predominantly based on whether their near-infrared spectral slope is similar to their optical spectral slope. The vast majority of cold classical TNOs, with dynamically quiescent orbits, have the FaintIR surface classification, and we infer that TNOs in other dynamical classifications with FaintIR surfaces share a common origin with the cold classical TNOs. Comparison between the resonant populations and the possible parent populations of cold classical and dynamically excited TNOs reveal that the 3:2 has minimal contributions from the FaintIR class, which could be explained by the $\nu_8$ secular resonance clearing the region near the 3:2 before any sweeping capture occurred. Conversely, the fraction of FaintIR objects in the 4:3 resonance, 2:1 resonance, and the resonances within the cold classical belt, suggest that the FaintIR surface formed in the protoplanetary disk between 34.6 and 47 au, though the outer bound depends on the degree of resonance sweeping during migration. The presence and absence of the FaintIR surfaces in Neptune's resonances provides critical constraints for the history of Neptune's migration, the evolution of the $\nu_8$, and the surface class distribution in the initial planetesimal diskComment: 19 pages, 8 figures. in Press at PS

You are what you eat? Vegetarianism, health and identity

This paper examines the views of ‘health vegetarians’ through a qualitative study of an online vegetarian message board. The researcher participated in discussions on the board, gathered responses to questions from 33 participants, and conducted follow-up e-mail interviews with 18 of these participants. Respondents were predominantly from the United States, Canada and the UK. Seventy per cent were female, and ages ranged from 14 to 53 years, with a median of 26 years. These data are interrogated within a theoretical framework that asks, ‘what can a vegetarian body do?’ and explores the physical, psychic, social and conceptual relations of participants. This provides insights into the identities of participants, and how diet and identity interact. It is concluded that vegetarianism is both a diet and a bodily practice with consequences for identity formation and stabilisation

Who am I? : Representing the self offline and in different online contexts

The present paper examines the extent to which self-presentation may be affected by the context in which is it undertaken. Individuals were asked to complete the Twenty Statements Test both privately and publicly, but were given an opportunity to withhold any of their personal information before it was made public. Four contexts were examined: an offline context (face-to-face), an un-contextualized general online context, or two specific online contexts (dating or job-seeking). The results suggested that participants were willing to disclose substantially less personal information online than offline. Moreover, disclosure decreased as the online context became more specific, and those in the job-seeking context disclosed the least amount of information. Surprisingly, individual differences in personality did not predict disclosure behavior. Instead, the results are set in the context of audience visibility and social norms, and implications for self-presentation in digital contexts are discussed

The Conservation Status of Marine Bony Shorefishes of the Greater Caribbean

The greater Caribbean biogeographic region covered in this report (representing 38 countries and territories) encompasses an outstanding marine bony shorefish richness of approximately 1,360 species, with many (53%) being endemic. This report provides an overview of the conservation status of greater Caribbean shorefishes, with detailed information available through the IUCN Red List, and gives recommendations

De Jure Determinants of New Firm Formation: How the Pillars of Constitutions Influence Entrepreneurship

This paper provides empirical evidence supporting the view that constitutions may influence the organization of economic activities. Dealing with the issue of the institutional determinants of entrepreneurship, it shows that some of the provisions contained in national constitutions are positively and significantly associated to a standard measure of entrepreneurial dynamics, namely the rate of new business density. Using a novel dataset containing the characteristics of the constitutions enacted in the world and a sample of 115 countries, the paper finds that provisions about the right to conduct/establish a business, the right to strike, consumer protection, protection of trademarks, and education promote higher rates of new firm formation