Cored Rutherford cables for the GSI fast ramping synchrotron

The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 200 T/spl middot/m and 100 T/spl middot/m. Fast ramp times are needed, which can cause significant problems for the magnets, particularly in the areas of ac loss and field distortion. This paper discusses the 200 T/spl middot/m ring, which will use Cos/spl theta/ magnets based on the RHIC dipole design. We discuss the reasons for choosing Rutherford cable with a resistive core and report loss measurements carried out on cable samples. These measurements are compared with theoretical calculations using measured values of inter-strand resistance. Reasonably good agreement is found, but there are indications of nonuniformity in the adjacent resistance R/sub a/. Using these measured parameters, losses and temperature rise are calculated for a RHIC dipole in the operating cycle of the accelerator. A novel insulation scheme designed to promote efficient cooling is described

Population-based screen-detected type 2 diabetes mellitus is associated with less need for insulin therapy after 10 years

INTRODUCTION: With increased duration of type 2 diabetes, most people have a growing need of glucose-lowering medication and eventually might require insulin. Presumptive evidence is reported that early detection (eg, by population-based screening) and treatment of hyperglycemia will postpone the indication for insulin treatment. A treatment legacy effect of population-based screening for type 2 diabetes of about 3 years is estimated. Therefore, we aim to compare insulin prescription and glycemic control in people with screen-detected type 2 diabetes after 10 years with data from people diagnosed with type 2 diabetes seven (treatment legacy effect) and 10 years before during care-as-usual. RESEARCH DESIGN AND METHODS: Three cohorts were compared: one screen-detected cohort with 10 years diabetes duration (Anglo-Danish-Dutch study of Intensive Treatment in People with Screen-Detected Diabetes in Primary care (ADDITION-NL): n=391) and two care-as-usual cohorts, one with 7-year diabetes duration (Groningen Initiative to Analyze Type 2 Diabetes Treatment (GIANTT) and Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC): n=4473) and one with 10-year diabetes duration (GIANTT and ZODIAC: n=2660). Insulin prescription (primary outcome) and hemoglobin A1c (HbA1c) of people with a known diabetes duration of 7 years or 10 years at the index year 2014 were compared using regression analyses. RESULTS: Insulin was prescribed in 10.5% (10-year screen detection), 14.7% (7-year care-as-usual) and 19.0% (10-year care-as-usual). People in the 7-year and 10-year care-as-usual groups had a 1.5 (95% CI 1.0 to 2.1) and 1.8 (95% CI 1.3 to 2.7) higher adjusted odds for getting insulin prescribed than those after screen detection. Lower HbA1c values were found 10 years after screen detection (mean 50.1 mmol/mol (6.7%) vs 51.8 mmol/mol (6.9%) and 52.8 mmol/mol (7.0%)), compared with 7 years and 10 years after care-as-usual (MDadjusted: 1.6 mmol/mol (95% CI 0.6 to 2.6); 0.1% (95% CI 0.1 to 0.2) and 1.8 mmol/mol (95% CI 0.7 to 2.9); and 0.2% (95% CI 0.1 to 0.3)). CONCLUSION: Population-based screen-detected type 2 diabetes is associated with less need for insulin after 10 years compared with people diagnosed during care-as-usual. Glycemic control was better after screen detection but on average good in all groups

The effect of chronic kidney disease on tissue formation of in situ tissue-engineered vascular grafts

Vascular in situ tissue engineering encompasses a single-step approach with a wide adaptive potential and true off-the-shelf availability for vascular grafts. However, a synchronized balance between breakdown of the scaffold material and neo-tissue formation is essential. Chronic kidney disease (CKD) may influence this balance, lowering the usability of these grafts for vascular access in end-stage CKD patients on dialysis. We aimed to investigate the effects of CKD on in vivo scaffold breakdown and tissue formation in grafts made of electrospun, modular, supramolecular polycarbonate with ureido-pyrimidinone moieties (PC-UPy). We implanted PC-UPy aortic interposition grafts (n = 40) in a rat 5/6th nephrectomy model that mimics systemic conditions in human CKD patients. We studied patency, mechanical stability, extracellular matrix (ECM) components, total cellularity, vascular tissue formation, and vascular calcification in CKD and healthy rats at 2, 4, 8, and 12 weeks post-implantation. Our study shows successful in vivo application of a slow-degrading small-diameter vascular graft that supports adequate in situ vascular tissue formation. Despite systemic inflammation associated with CKD, no influence of CKD on patency (Sham: 95% vs CKD: 100%), mechanical stability, ECM formation (Sirius red +, Sham 16.5% vs CKD 25.0%-p:0.83), tissue composition, and immune cell infiltration was found. We did find a limited increase in vascular calcification at 12 weeks (Sham 0.08% vs CKD 0.80%-p:0.02) in grafts implanted in CKD animals. However, this was not associated with increased stiffness in the explants. Our findings suggest that disease-specific graft design may not be necessary for use in CKD patients on dialysis. </p

Hypthesis and theory

Seabirds are amongst the most mobile of all animal species and spend large amounts of their lives at sea. They cross vast areas of ocean that appear superficially featureless, and our understanding of the mechanisms that they use for navigation remains incomplete, especially in terms of available cues. In particular, several large-scale navigational tasks, such as homing across thousands of kilometers to breeding sites, are not fully explained by visual, olfactory or magnetic stimuli. Low-frequency inaudible sound, i.e., infrasound, is ubiquitous in the marine environment. The spatio-temporal consistency of some components of the infrasonic wavefield, and the sensitivity of certain bird species to infrasonic stimuli, suggests that infrasound may provide additional cues for seabirds to navigate, but this remains untested. Here, we propose a framework to explore the importance of infrasound for navigation. We present key concepts regarding the physics of infrasound and review the physiological mechanisms through which infrasound may be detected and used. Next, we propose three hypotheses detailing how seabirds could use information provided by different infrasound sources for navigation as an acoustic beacon, landmark, or gradient. Finally, we reflect on strengths and limitations of our proposed hypotheses, and discuss several directions for future work. In particular, we suggest that hypotheses may be best tested by combining conceptual models of navigation with empirical data on seabird movements and in-situ infrasound measurements

Off-the-Shelf Synthetic Biodegradable Grafts Transform In Situ into a Living Arteriovenous Fistula in a Large Animal Model

Current vascular access options require frequent interventions. In situ tissue engineering (TE) may overcome these limitations by combining the initial success of synthetic grafts with long-term advantages of autologous vessels by using biodegradable grafts that transform into autologous vascular tissue at the site of implantation. Scaffolds (6 mm-Ø) made of supramolecular polycarbonate-bisurea (PC-BU), with a polycaprolactone (PCL) anti-kinking-coil, are implanted between the carotid artery and jugular vein in goats. A subset is bio-functionalized using bisurea-modified-Stromal cell-derived factor-1α (SDF1α) derived peptides and ePTFE grafts as controls. Grafts are explanted after 1 and 3 months, and evaluated for material degradation, tissue formation, compliance, and patency. At 3 months, the scaffold is resorbed and replaced by vascular neo-tissue, including elastin, contractile markers, and endothelial lining. No dilations, ruptures, or aneurysms are observed and grafts are successfully cannulated at termination. SDF-1α-peptide-biofunctionalization does not influence outcomes. Patency is lower in TE grafts (50%) compared to controls (100% patency), predominantly caused by intimal hyperplasia. Rapid remodeling of a synthetic, biodegradable vascular scaffold into a living, compliant arteriovenous fistula is demonstrated in a large animal model. Despite lower patency compared to ePTFE, transformation into autologous and compliant living tissue with self-healing capacity may have long-term advantages.</p