Silsesquioxane polymer as a potential scaffold for laryngeal reconstruction

Cancer, disease and trauma to the larynx and their treatment can lead to permanent loss of structures critical to voice, breathing and swallowing. Engineered partial or total laryngeal replacements would need to match the ambitious specifications of replicating functionality, outer biocompatibility, and permissiveness for an inner mucosal lining. Here we present porous polyhedral oligomeric silsesquioxane-poly(carbonate urea) urethane (POSS-PCUU) as a potential scaffold for engineering laryngeal tissue. Specifically, we employ a precipitation and porogen leaching technique for manufacturing the polymer. The polymer is chemically consistent across all sample types and produces a foam-like scaffold with two distinct topographies and an internal structure composed of nano- and micro-pores. Whilst the highly porous internal structure of the scaffold contributes to the complex tensile behaviour of the polymer, the surface of the scaffold remains largely non-porous. The low number of pores minimise access for cells, although primary fibroblasts and epithelial cells do attach and proliferate on the polymer surface. Our data show that with a change in manufacturing protocol to produce porous polymer surfaces, POSS-PCUU may be a potential candidate for overcoming some of the limitations associated with laryngeal reconstruction and regeneration

Precise determination of the Wtb couplings at LHC

Top pair production at LHC is the ideal place to search for nonstandard Wtb couplings in t -> W b -> l nu b decays. The lb forward-backward asymmetry in the W rest frame is very sensitive to sigma_{mu nu} couplings, and can spot one-loop QCD corrections to the decay vertex with more than 5 sigma statistical significance. We discuss the potential of this asymmetry to signal nonstandard gamma_mu and sigma_{mu nu} couplings and compare with top-antitop spin correlation asymmetries, which have a lower sensitivity. We also briefly summarise the results for Tevatron.Comment: LaTeX, 12 pages, 2 PS figures. One reference added. To be published in PR

Comparison of general population, patient, and carer utility values for dementia health states.

Utility values to estimate quality-adjusted life years (QALYs) for use in cost-utility analyses are usually elicited from members of the general population. Public attitudes and understanding of dementia in particular may mean that values elicited from the general population may differ from patients and carers for dementia health states. This study examines how the population impacts utility values elicited for dementia health states using interviewer-administered time tradeoff valuation of health states defined by the dementia-specific preference-based measures DEMQOL-U (patient-report) and DEMQOL-Proxy-U (carer-report). Eight DEMQOL-U states were valued by 78 members of the UK general population and 71 patients with dementia of mild severity. Eight DEMQOL-Proxy-U states were valued by 77 members of the UK general population and 71 carers of patients with dementia of mild severity. Random-effects generalized least squares regression estimated the impact of population, dementia health state, and respondent sociodemographic characteristics on elicited values, finding that values for dementia health states differed by population and that the difference varied across dementia health states. Patients with dementia and carers of patients with dementia gave systematically lower values than members of the general population that were not due to differences in the sociodemographic characteristics of the populations. Our results suggest that the population used to produce dementia health state values could impact the results of cost-utility analyses and potentially affect resource allocation decisions; yet, currently, only general population values are available for usage

Overlapping functions of the cell adhesion molecules Nr-CAM and L1 in cerebellar granule cell development

The structurally related cell adhesion molecules L1 and Nr-CAM have overlapping expression patterns in cerebellar granule cells. Here we analyzed their involvement in granule cell development using mutant mice. Nr-CAM–deficient cerebellar granule cells failed to extend neurites in vitro on contactin, a known ligand for Nr-CAM expressed in the cerebellum, confirming that these mice are functionally null for Nr-CAM. In vivo, Nr-CAM–null cerebella did not exhibit obvious histological defects, although a mild size reduction of several lobes was observed, most notably lobes IV and V in the vermis. Mice deficient for both L1 and Nr-CAM exhibited severe cerebellar folial defects and a reduction in the thickness of the inner granule cell layer. Additionally, anti-L1 antibodies specifically disrupted survival and maintenance of Nr-CAM–deficient granule cells in cerebellar cultures treated with antibodies. The combined results indicate that Nr-CAM and L1 play a role in cerebellar granule cell development, and suggest that closely related molecules in the L1 family have overlapping functions

Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil

Iron intakes calculated from one-day weighed records were compared with those from same day analyzed duplicate diet composites collected from 120 Malawian women living in two rural districts with contrasting soil mineralogy and where threshing may contaminate cereals with soil iron. Soils and diet composites from the two districts were then subjected to a simulated gastrointestinal digestion and iron availability in the digests measured using a Caco-2 cell model. Median analyzed iron intakes (mg/d) were higher (p < 0.001) than calculated intakes in both Zombwe (16.6 vs. 10.1 mg/d) and Mikalango (29.6 vs. 19.1 mg/d), attributed to some soil contaminant iron based on high Al and Ti concentrations in diet composites. A small portion of iron in acidic soil from Zombwe, but not Mikalango calcareous soil, was bioavailable, as it induced ferritin expression in the cells, and may have contributed to higher plasma ferritin and total body iron for the Zombwe women reported earlier, despite lower iron intakes. In conclusion, iron intakes calculated from food composition data were underestimated, highlighting the importance of analyzing duplicate diet composites where extraneous contaminant iron from soil is likely. Acidic contaminant soil may make a small but useful contribution to iron nutrition

The fully differential single-top-quark cross section in next-to-leading order QCD

We present a new next-to-leading order calculation for fully differential single-top-quark final states. The calculation is performed using phase space slicing and dipole subtraction methods. The results of the methods are found to be in agreement. The dipole subtraction method calculation retains the full spin dependence of the final state particles. We show a few numerical results to illustrate the utility and consistency of the resulting computer implementations.Comment: 37 pages, latex, 2 ps figure

The t W- Mode of Single Top Production

The t W- mode of single top production is proposed as an important means to study the weak interactions of the top quark. While the rate of this mode is most likely too small to be observed at Run II of the Fermilab Tevatron, it is expected to be considerably larger at the CERN LHC. In this article the inclusive t W- rate is computed, including O(1 / log (m_t^2 / m_b^2)) corrections, and when combined with detailed Monte Carlo simulations including the top and W decay products, indicate that the t W- single top process may be extracted from the considerable t tbar and W+ W- j backgrounds at low luminosity runs of the LHC.Comment: 16 pages, 4 figure