Correlation effects in the density of states of annealed GaMnAs

We report on an experimental study of low temperature tunnelling in hybrid NbTiN/GaMnAs structures. The conductance measurements display a root mean square V dependence, consistent with the opening of a correlation gap in the density of states of GaMnAs. Our experiment shows that low temperature annealing is a direct empirical tool that modifies the correlation gap and thus the electron-electron interaction. Consistent with previous results on boron-doped silicon we find, as a function of voltage, a transition across the phase boundary delimiting the direct and exchange correlation regime.Comment: Replaced with revised version. To appear in Phys. Rev.

Variations in vascular access flows in haemodialysis can depend on needle orientation

Introduction: While using the Transonic Qc[TM] machine to assess access flow in arteriovenous fistulae (AVF), we observed that when compared to antegrade arterial needle insertion, retrograde arterial needle insertion could regularly produce lower access flow measurements. This study sought to explore this phenomenon. Method: 23 patients entered and 20 finished the study. Patient selection criteria included: functioning AVF and an adequate AVF length for either retrograde or antegrade arterial needle insertion. After ensuring stable and similar blood pressures, 3 flow measurements were taken during the first 2 hours on the same dialysis day of 3 consecutive weeks using antegrade needle insertion then were repeated on 3 further consecutive weeks using retrograde insertion. Results: Overall, access flows measured with retrograde insertion were significantly lower by a mean difference of 107.15 ml/min (57-484 ml/min) than the flows measured with antegrade needle placement. In 5/20, 3 recorded minimal difference and 2 had a higher access flows during retrograde insertion. No recirculation was observed during either antegrade or retrograde needle insertion. The paired t-test showed that there was significant difference between the antegrade versus retrograde mean measurements (p = 0.005). Conclusion: Although the sample size is small and the number of measurements limited, we conclude that access flows may be greater with an antegrade arterial orientation compared to flows recorded with a retrograde orientation. The phenomenon behind this conclusion is yet to be investigated. We suggest that when using the Transonic Qc[TM] access measurement device the arterial needle should always be in the same direction for each measurement for each individual patient.<br /

In Vitro Nephrotoxicity Studies of Established and Experimental Platinum-Based Compounds

Cisplatin is one of the most commonly used drugs for the treatment of various solid cancers. However, its efficacy is restricted by severe side effects, especially dose-limiting nephrotoxicity. New platinum-based compounds are designed to overcome this limitation. Previous investigations showed that the platinum(IV)–nitroxyl complex PN149 is highly cytotoxic in various tumor cell lines. In the present study, investigations with PN149 were extended to normal human kidney tubule epithelia. Coincident with higher intracellular platinum accumulation, the cytotoxicity of PN149 in the proximal tubule epithelial cell line ciPTEC was more pronounced compared to the established platinum chemotherapeutics cisplatin, carboplatin and oxaliplatin. Quantitative gene expression profiling revealed the induction of ROS-inducible and anti-oxidative genes, suggesting an oxidative stress response by PN149. However, in contrast to cisplatin, no pro-inflammatory response was observed. Genes coding for distinct DNA damage response factors and genes related to apoptosis were up-regulated, indicating the activation of the DNA damage response system and induction of the apoptotic cascade by PN149. Altogether, a comparable transcriptional response was observed for PN149 and the platinum chemotherapeutics. However, the lack of inflammatory activity, which is a possible cause contributing to toxicity in human renal proximal tubule epithelia, might indicate the reduced nephrotoxic potential of PN149

Investigating well-being, work limitations and preferences for self-management education and peer support among younger people with hip and knee osteoarthritis: protocol for a cross-sectional study

Introduction:&nbsp;Osteoarthritis (OA) has traditionally&nbsp;been considered a condition of older age. However,&nbsp;younger people are also affected by hip and knee OA,&nbsp;often as a result of sporting and work-related injuries.&nbsp;As OA studies have generally focused on older&nbsp;individuals, little is known about the experience of&nbsp;younger adults with hip or knee OA who can face a&nbsp;distinct set of pressures including work responsibilities&nbsp;and parenting roles. This study aims to investigate&nbsp;well-being and work participation among younger&nbsp;people with hip or knee OA, as well as preferences for&nbsp;OA education and support.Methods and analysis: 200 people aged 20&ndash;55 years with a diagnosis of hip and/or knee OA will be&nbsp;recruited for this cross-sectional study. Participants will&nbsp;be recruited from three major public hospitals in the&nbsp;state of Victoria, Australia following screening of&nbsp;orthopaedic outpatient clinic lists and referrals, and&nbsp;through community-based advertisements. A study&nbsp;questionnaire will be mailed to all participants and&nbsp;written informed consent obtained. Validated measures&nbsp;of Health-Related Quality of Life (HRQoL), health status,&nbsp;psychological distress and work limitations will be used. Information on health services use will be collected,&nbsp;in addition to information on the perceived utility and&nbsp;accessibility of a range of existing and proposed&nbsp;education and peer support models. HRQoL data will be&nbsp;compared with Australian population norms using&nbsp;independent t tests, and associations between HRQoL,&nbsp;health status, psychological distress, work limitations&nbsp;and demographic factors will be evaluated using&nbsp;univariate and multivariate analyses. Data on the&nbsp;perceived utility and accessibility of education and peer&nbsp;support models will be analysed descriptively.&nbsp;Ethics and dissemination: Ethics approval for the&nbsp;study has been obtained. The study findings will be&nbsp;submitted to peer-reviewed journals and arthritis&nbsp;consumer organisations for broader dissemination, and&nbsp;presented at national and international scientific meetings.</div