15 research outputs found
Brazing of Mo to Glidcop Dispersion Strengthened Copper for Accelerating Structures
Alumina dispersion-strengthened copper, Glidcop, is used widely in high-heat-load
ultra-high-vacuum components for synchrotron light sources (absorbers), accelerator components (beam
intercepting devices), and in nuclear power plants. Glidcop has similar thermal and electrical properties
to oxygen free electrical (OFE) copper, but has superior mechanical properties, thus making it a feasible
structural material; its yield and ultimate tensile strength are equivalent to those of mild-carbon steel.
The purpose of this work has been to develop a brazing technique to join Glidcop to Mo, using a
commercial Cu-based alloy. The effects of the excessive diffusion of the braze along the grain boundaries
on the interfacial chemistry and joint microstructure, as well as on the mechanical performance of the
brazed joints, has been investigated. In order to prevent the diffusion of the braze into the Glidcop alloy,
a copper barrier layer has been deposited on Glidcop by means of RF-sputtering
Swiss cost-effectiveness analysis of universal screening for Lynch syndrome of patients with colorectal cancer followed by cascade genetic testing of relatives.
BACKGROUND
We estimated the cost-effectiveness of universal DNA screening for Lynch syndrome (LS) among newly diagnosed patients with colorectal cancer (CRC) followed by cascade screening of relatives from the Swiss healthcare system perspective.
METHODS
We integrated decision trees with Markov models to calculate incremental cost per quality-adjusted life-year saved by screening all patients with CRC (alternative strategy) compared with CRC tumour-based testing followed by DNA sequencing (current strategy).
RESULTS
The alternative strategy has an incremental cost-effectiveness ratio of CHF65 058 compared with the current strategy, which is cost-effective according to Swiss standards. Based on annual incidence of CRC in Switzerland, universal DNA screening correctly identifies all 123 patients with CRC with LS, prevents 17 LS deaths and avoids 19 CRC cases, while the current strategy leads to 32 false negative results and 253 LS cases lost to follow-up. One way and probabilistic sensitivity analyses showed that universal DNA testing is cost-effective in around 80% of scenarios, and that the cost of DNA testing and the number of invited relatives per LS case determine the cost-effectiveness ratio.
CONCLUSION
Results can inform policymakers, healthcare providers and insurance companies about the costs and benefits associated with universal screening for LS and cascade genetic testing of relatives
Brazing of Mo to Glidcop Dispersion Strengthened Copper for Accelerating Structures
Alumina dispersion-strengthened copper, Glidcop, is used widely in high-heat-load ultra-high-vacuum components for synchrotron light sources (absorbers), accelerator components (beam intercepting devices), and in nuclear power plants. Glidcop has similar thermal and electrical properties to oxygen free electrical (OFE) copper, but has superior mechanical properties, thus making it a feasible structural material; its yield and ultimate tensile strength are equivalent to those of mild-carbon steel. The purpose of this work has been to develop a brazing technique to join Glidcop to Mo, using a commercial Cu-based alloy. The effects of the excessive diffusion of the braze along the grain boundaries on the interfacial chemistry and joint microstructure, as well as on the mechanical performance of the brazed joints, has been investigated. In order to prevent the diffusion of the braze into the Glidcop alloy, a copper barrier layer has been deposited on Glidcop by means of RF-sputtering
Brazing of Mo to a CuZr alloy for the production of bimetallic raw materials for the CLIC accelerating structures
Future linear accelerators, as CLIC (Compact Linear Collider), are extremely demanding in terms of material properties. Traditionally accelerating structure is made of brazed OFE copper parts. For the high conducting regions submitted to mechanical fatigue, CuZr would represent an improved selection than pure copper while for regions where the highest electric field is applied a refractory metal, i.e. Mo, could result in a better performance. The feasibility of joining such materials, namely CuZr (UNS C15000) and pure Mo has been investigated. The joining method developed and investigated here consists in a vacuum brazing process exploiting a Cu-based brazing filler applied under appropriate vacuum conditions. Apparent shear strength (adapted from ASTM B898) on the joined samples was about 200 MPa. (C) 2010 Elsevier B.V. All rights reserved
A Dietary Intervention to Lower Serum Levels of IGF-I in BRCA Mutation Carriers
Background: Insulin-like growth factor I (IGF-I) and other markers of insulin resistance (IRm) might influence the penetrance of BRCA gene mutation. In a demonstration project on BRCA mutation carriers we tested the effect of the ‘Mediterranean diet’, with moderate protein restriction, on serum levels of IGF-I and IRm. Methods: BRCA mutation carriers, with or without breast cancer, aged 18–70 years and without metastases were eligible. After the baseline examinations, women were randomized to an active dietary intervention or to a control group. The intervention group attended six full days of life-style intervention activities (cookery classes followed by lunch, sessions of walking for 45 min and nutritional conferences) over the next six months. Results: 213 BRCA mutation carriers completed the six-month study. Women in the intervention group (110) showed major changes in all the parameters under study. They significantly lost weight (p < 0.001), fat mass (p = 0.002), with reduced hip circumference (p = 0.01), triglycerides (p = 0.02) and IGF-I (p = 0.02) compared with controls. They also had a significantly higher levels of insulin-like growth factor-binding protein 3 (IGFI-BP3) (p = 0.03) and a lower IGF-I/IGFI-BP3 ratio (p = 0.04). The reduction of serum levels of IGF-I was significantly associated with the reduction in the consumption of animal products (p = 0.04). Conclusions: Women in the intervention group showed significant improvements in IGF-I and in other IRm that might influence the penetrance of BRCA mutations