249 research outputs found
FIRST BEAM FROM THE TRASCO INTENSE PROTON SOURCE (TRIPS) AT INFN-LNS
Abstract The TRASCO intense proton source (TRIPS) has been installed at INFN-LNS THE SOURCE DESIGN The TRASCO Project is a R&D program which goal is the design of an Accelerator Driving System (ADS) for nuclear waste transmutation. The high current cw proton linear accelerator will drive a subcritical system to transmutate nuclear wastes. [1] The accelerator design is shared between different INFN laboratories and the LNS is in charge of the source design and construction. The proton source TRIPS is a high intensity microwave source, which goal is the injection of a minimum proton current of 35 mA in the following RFQ [2], with a rms normalized emittance lower than 0.2π⋅mm⋅mrad for an operating voltage of 80 kV. With respect to other sources for high intensity applications, some new features have been added, according to our experience with the high-intensity source SILHI • the microwave matching system has been improved; • a system to move the coils on-line has been realized; • the extraction system has been optimised with the aim to increase the source availability and reliability, in order to meet the requirement of a driver for an ADS system. The final design of TRIPS is shown in 2 The gaps, the voltage and the extraction holes have been designed in order to reduce the length of the extraction zone (where the beam is uncompensated) and to reduce the aperture-lens effect. Rms normalized emittance below 0.2π mm mrad (including the beam halo) have been calculated EXPERIMENTAL RESULTS CONCLUSION AND FUTURE DEVELOPMENTS In table 1 the status of the source is compared with the requirements of the TRASCO project. The requested reliability at 80 kV is not yet achieved, but the source performance are already good in terms of beam intensity, reproducibility and stability. The innovative solutions presented above have confirmed their validity. We are confident that in a few months a more significant reliability test at 80 3 kV (over two weeks) can be done. As this goal will be accomplished, the emittance measurements can be done with a similar emittance measuring device as the one described in ACKNOWLEDGEMENT
Installation of ECR2 at LNS and Preliminary tests
The source ECR2 has been built in 1998 by Pantechnik, according to the design suggested by LNS Ion Source Group. This design entails some improvements with respect to a standard CAPRICE-type source: a) the magnetic field (up to 1.6 T axial, 1.1 T radial) allows to operate the source at 14 GHz in High B mode and at 18 GHz; b) two frequency heating can be used; c) an aluminum made plasma chamber is used in place of the stainless steel one. The main features of ECR2 along with a review of the preliminary tests will be outlined. Typical currents for fully stripped nitrogen are about 25 emA; for the heaviest ions, 1 emA of Kr28+ and 10 emA of Ta27+ have been measured. The installation at LNS has been completed recently and the details will be given
Summary of the performances of the superconducting electron cyclotron resonance ion source at 14 GHz
This article deals with the most recent performance of the superconducting electron cyclotron resonance ion source (SERSE) working at 14 GHz with high magnetic fields after the required conditioning and optimization of several operating parameters. SERSE has now achieved an outstanding level of performance in delivering highly charged ion beams in argon and oxygen gases: the results obtained while operating in a stainless steel chamber and with an aluminum liner are shown and discussed
Production of intense highly charged ion beams with SERSE
The source SERSE is operational at LNS since June 1998 and many improvements have been carried out in this period. The frequency has been increased from 14.5 GHz to 18 GHz and the use of two frequency heating has given positive results. Metallic ion production has been tested by means of a high temperature oven and the preliminary results are described. Tests of magnetic field scaling and frequency scaling have confirmed the results of previous tests with SC-ECRIS at lower frequency and seems to suggest that the upgrading of the source to higher frequency may be considered
Treatment‐related changes in bone turnover and fracture risk reduction in clinical trials of antiresorptive drugs: proportion of treatment effect explained
Few analyses of antiresorptive (AR) treatment trials relate short‐term changes in bone turnover markers (BTMs) to subsequent fracture reduction seeking to estimate the proportion of treatment effect explained (PTE) by BTMs. Pooling such information would be useful to assess new ARs or novel dosing regimens. In the Foundation for the National Institutes of Health (FNIH) Bone Quality project, we analyzed individual‐level data from up to 62,000 participants enrolled in 12 bisphosphonate (BP) and four selective estrogen receptor modulator (SERM) placebo‐controlled fracture endpoint trials. Using BTM results for two bone formation markers (bone‐specific alkaline phosphatase [bone ALP] and pro‐collagen I N‐propeptide [PINP]) and one bone resorption marker (C‐terminal telopeptide of type I collagen [CTX]) and incident fracture outcome data, we estimated the PTE using two different models. Separate analyses were performed for incident morphometric vertebral, nonvertebral, and hip fractures over 1 to 5 years of follow‐up. For vertebral fracture, the results showed that changes in all three BTMs at 6 months explained a large proportion of the treatment effect of ARs (57 to >100%), but not for and non‐vertebral or hip fracture. We conclude that short‐term AR treatment‐related changes in bone ALP, PINP, and CTX account for a large proportion of the treatment effect for vertebral fracture. Change in BTMs is a useful surrogate marker to study the anti‐fracture efficacy of new AR compounds or novel dosing regiments with approved AR drugs. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research
The Metabochip, a Custom Genotyping Array for Genetic Studies of Metabolic, Cardiovascular, and Anthropometric Traits
PMCID: PMC3410907This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The Flexible Plasma Trap (FPT) for the production of overdense plasmas
Electron Cyclotron Resonance Ion Sources are currently the most efficient ionsources among those used in facilities dedicated to nuclear physics. The needfor a more flexible magnetic field and RF injection system suggested to designand develop a different type of plasma trap, named Flexible Plasma Trap (FPT).The magnetic field of FPT is generated by means of three coils while microwavesin the range 4-7 GHz can be injected by three different inputs, one placedalong the axis and two placed radially. FPT can work in different plasmaheating schemes so it will be an ideal tool for studies of plasma andmultidisciplinary physics. Moreover, a microwave launcher has been designed andinstalled to the FPT for launching microwaves with a variable tilt angle withrespect to the magnetic field. This paper describes the characteristics of theFPT along with the preliminary results of plasma diagnostics
Genome-wide association scan meta-analysis identifies three Loci influencing adiposity and fat distribution.
To identify genetic loci influencing central obesity and fat distribution, we performed a meta-analysis of 16 genome-wide association studies (GWAS, N = 38,580) informative for adult waist circumference (WC) and waist-hip ratio (WHR). We selected 26 SNPs for follow-up, for which the evidence of association with measures of central adiposity (WC and/or WHR) was strong and disproportionate to that for overall adiposity or height. Follow-up studies in a maximum of 70,689 individuals identified two loci strongly associated with measures of central adiposity; these map near TFAP2B (WC, P = 1.9x10(-11)) and MSRA (WC, P = 8.9x10(-9)). A third locus, near LYPLAL1, was associated with WHR in women only (P = 2.6x10(-8)). The variants near TFAP2B appear to influence central adiposity through an effect on overall obesity/fat-mass, whereas LYPLAL1 displays a strong female-only association with fat distribution. By focusing on anthropometric measures of central obesity and fat distribution, we have identified three loci implicated in the regulation of human adiposity
A novel somatic mutation achieves partial rescue in a child with Hutchinson-Gilford progeria syndrome.
BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) is a fatal sporadic autosomal dominant premature ageing disease caused by single base mutations that optimise a cryptic splice site within exon 11 of the LMNA gene. The resultant disease-causing protein, progerin, acts as a dominant negative. Disease severity relies partly on progerin levels. METHODS AND RESULTS: We report a novel form of somatic mosaicism, where a child possessed two cell populations with different HGPS disease-producing mutations of the same nucleotide-one producing severe HGPS and one mild HGPS. The proband possessed an intermediate phenotype. The mosaicism was initially discovered when Sanger sequencing showed a c.1968+2T>A mutation in blood DNA and a c.1968+2T>C in DNA from cultured fibroblasts. Deep sequencing of DNA from the proband's blood revealed 4.7% c.1968+2T>C mutation, and 41.3% c.1968+2T>A mutation. CONCLUSIONS: We hypothesise that the germline mutation was c.1968+2T>A, but a rescue event occurred during early development, where the somatic mutation from A to C at 1968+2 provided a selective advantage. This type of mosaicism where a partial phenotypic rescue event results from a second but milder disease-causing mutation in the same nucleotide has not been previously characterised for any disease.Progeria experiments were funded by The Progeria Research Foundation grants PRF-2002-CB and PRF-2002-MRD (JFB, WEN, SEC, LBG), and by the Medical Research Council UK grant MR/L019116/1 (DL). Core and general laboratory grants are as follows: Kilguss Research Core of Women & Infants Hospital of Rhode Island through an Institutional Development Award from the NIGMS of the NIH (P30GM114750), intramural funds to the NHGRI (ZIA-HG200305), Cancer Research UK programme grant C6/A18796 and Wellcome Trust (WT092096)
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