Strong Focusing Cyclotron and Its Applications Pogue, Nathaniel J.; Chavez, Daniel; Kellams, Joshua ...
IEEE transactions on applied superconductivity,
2015-June, 2015-6-00, 20150601, Volume:
25, Issue:
3
Journal Article
Peer reviewed
A Strong Focusing cyclotron has been developed by the Accelerator Research Lab at Texas A&M to produce up to 10 mA of proton beam at 800 MeV. The cyclotron has several innovations that allow it to ...achieve such high levels of power. The first is the superconducting RF cavities that provide sufficient gain to separate the orbits by a minimum of 6 cm. This space allows for beam transport channels to be place along every orbit and provide continuous quadrupole focusing. Additionally, a trim dipole is added to the channel to allow for corrections to the main dipole. This document will show the new BTC design that allows for the cyclotron to be greatly simplified. The main dipole is kept below saturation and is shaped to levitate the poles. The main dipole, along with the RF cavity, are designed such that several cyclotrons could be stacked on top of one another. This design provides the high power beam required for several applications. These applications include accelerator driven systems, neutron damage facilities, and medical isotope production. Texas A&M has developed two designs for ADS fission: an isoburner and an isobreeder. Both of these designs will be expounded on within the document. A design for a neutron damage facility and it capabilities are presented as well as a medical isotope production design. The SFC has great potential to revolutionize these fields and be of great service to the US.
The wafer test cavity was designed as a short sample test system that could create a reproducible environment for the testing of superconducting materials above the Bardeen-Cooper- Schrieffer limit ...of niobium. The results of the sapphire test cavity showed that the dielectric was too lossy, and thus, the original design had to be altered to make operation feasible with current hardware and achieve ~200 mT. The new design was fabricated at Thomas Jefferson National Accelerator Facility and was cryogenically tested. After four tests, the cavity was able to produce a 6.6-mT field with a Q of 3.96 * 10 8 . Although lower than anticipated, in comparison to other TE01 cavities, this result is quite encouraging. Multipacting and coupling were limitations, but current work is pursuing the elimination of these complications. This document will expound upon the new design, mathematical simulations, testing of the cavity, complications, results, and future work.
CONTEXT The optimal unfractionated heparin regimen for percutaneous coronary intervention (PCI) in patients with non–ST-segment elevation acute coronary syndromes treated with fondaparinux is ...uncertain. OBJECTIVE To compare the safety of 2 unfractionated heparin regimens during PCI in high-risk patients with non–ST-segment elevation acute coronary syndromes initially treated with fondaparinux. DESIGN, SETTING, AND PARTICIPANTS Double-blind randomized parallel-group trial in 179 hospitals in 18 countries involving 2026 patients undergoing PCI within 72 hours, nested within a cohort of 3235 high-risk patients with non–ST-segment elevation acute coronary syndromes initially treated with fondaparinux enrolled from February 2009 to March 2010. INTERVENTIONS Patients received intravenously either low-dose unfractionated heparin, 50 U/kg, regardless of use of glycoprotein IIb/IIIa (GpIIb-IIIa) inhibitors or standard-dose unfractionated heparin, 85 U/kg (60 U/kg with GpIIb-IIIa inhibitors), adjusted by blinded activated clotting time (ACT). MAIN OUTCOME MEASURES Composite of major bleeding, minor bleeding, or major vascular access-site complications up to 48 hours after PCI. Key secondary outcomes include composite of major bleeding at 48 hours with death, myocardial infarction, or target vessel revascularization within day 30. RESULTS The primary outcome occurred in 4.7% of those in the low-dose group vs 5.8% in the standard-dose group (odds ratio OR, 0.80; 95% confidence interval CI, 0.54-1.19; P = .27). The rates of major bleeding were not different but the rates of minor bleeding were lower with 0.7% in the low-dose group vs 1.7% in the standard-dose group (OR, 0.40; 95% CI, 0.16-0.97; P = .04). For the key secondary outcome, the rates for low-dose group were 5.8% vs 3.9% in the standard-dose group (OR, 1.51; 95% CI, 1.00-2.28; P = .05) and for death, myocardial infarction, or target vessel revascularization it was 4.5% for the low-dose group vs 2.9% for the standard-dose group (OR, 1.58; 95% CI, 0.98-2.53; P = .06). Catheter thrombus rates were very low (0.5% in the low-dose group and 0.1% in the standard-dose group, P = .15). CONCLUSION Low-dose compared with standard-dose unfractionated heparin did not reduce major peri-PCI bleeding and vascular access-site complications. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00790907
Oxidative modification of low-density lipoprotein is an important step in the development and progression of atherosclerosis in experimental studies,
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and antioxidants such as vitamin E have ...been shown to slow atherosclerosis.
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An inverse relation has been observed between coronary heart disease and the consumption of fruits, vegetables, and other foods containing vitamins, particularly vitamin E.
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Observational studies have indicated that persons who consume more than 100 IU of vitamin E a day for more than two years have lower rates of coronary events
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and lower rates of progression of coronary artery lesions.
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However, observational studies cannot . . .
Electrocardiographic markers of left ventricular hypertrophy (LVH) predict poor prognosis. We determined whether the ACE inhibitor ramipril prevents the development and causes regression of ECG-LVH ...and whether these changes are associated with improved prognosis independent of blood pressure reduction.
In the Heart Outcomes Prevention Evaluation (HOPE) study, patients at high risk were randomly assigned to ramipril or placebo and followed for 4.5years. ECGs were recorded at baseline and at study end. We compared prevention/regression and development/persistence of ECG-LVH in the two groups and related these changes to outcomes. At baseline, 676 patients had LVH (321 in the ramipril group and 355 in the placebo group) and 7605 patients did not have LVH (3814 in the ramipril group and 3791 in the placebo group). By study end, 336 patients in the ramipril group (8.1%) compared with 406 in the placebo group (9.8%) had development/persistence of LVH; in contrast, 3799 patients in the ramipril group (91.9%) compared with 3740 in the placebo group (90.2%) had regression/prevention of LVH (P=0.007). The effect of ramipril on LVH was independent of blood pressure changes. Patients who had regression/prevention of LVH had a lower risk of the predefined primary outcome (cardiovascular death, myocardial infarction, or stroke) compared with those who had development/persistence of LVH (12.3% versus 15.8%, P=0.006) and of congestive heart failure (9.3% versus 15.4%, P<0.0001).
The ACE inhibitor ramipril decreases the development and causes regression of ECG-LVH independent of blood pressure reduction, and these changes are associated with reduced risk of death, myocardial infarction, stroke, and congestive heart failure.
We propose the adaptation of classical monitoring boundaries for use in cumulative meta-analysis as guidelines for deciding when accumulating evidence is statistically significant and medically ...convincing. The interpretation of information from a randomized controlled trial is compared with that from a meta-analysis. The concept of optimal information size for a meta-analysis is developed and used to adapt monitoring boundaries to cumulative meta-analysis.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Although dyslipidemia, diabetes, smoking, and hypertension are major risk factors for cardiovascular disease, they do not fully account for the risk. Therefore, other risk factors must be identified ...in order to reduce mortality and morbidity even further. Epidemiologic and experimental data suggest that activation of the renin–angiotensin–aldosterone system has an important role in increasing the risk of cardiovascular events.
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Angiotensin-converting–enzyme inhibitors block the activation of the renin–angiotensin system and could retard the progression of both heart failure and atherosclerosis. In a meta-analysis of three studies
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that included more than 9000 patients with low ejection fractions, treatment with angiotensin-converting–enzyme inhibitors . . .
In ACTIVE-W, oral anticoagulation (OAC) was more efficacious than combined clopidogrel plus aspirin (C+A) in preventing vascular events in patients with atrial fibrillation. However, because OAC ...carries important bleeding complications, risk stratification schemes have been devised to identify patients for whom the absolute benefits of OAC exceed its risks.
Participants were risk-stratified with the widely-used CHADS(2) scheme. Treatment-specific rates of stroke and major bleeding were calculated for patients with a CHADS(2)=1 and compared to those with a CHADS(2)>1.
Observed stroke rates for those with a CHADS(2)=1 were 1.25% per year on C+A and 0.43% per year on OAC (RR=2.96, 95% CI: 1.26 to 6.98, P=0.01). Among patients with a CHADS(2)>1, the stroke rates were 3.15% per year on C+A and 2.01% per year on OAC (RR=1.58, 95% CI: 1.11 to 2.24, P=0.01) (P for interaction between stroke risk category and efficacy of OAC=0.19). The risk of major bleeding during OAC was significantly lower among patients with CHADS(2)=1 (1.36% per year) compared with CHADS(2)>1 (2.75% per year) (RR=0.49, 95% CI 0.30 to 0.79, P=0.003).
In this clinical trial, patients with a CHADS(2)=1 had a low risk of stroke, yet still derived a modest (<1% per year) but statistically significant absolute reduction in stroke with OAC and had low rates of major hemorrhage on OAC.
Abstract Objective: To determine the effect of the angiotensin converting enzyme inhibitor ramipril on the secondary prevention of stroke. Design: Randomised controlled trial with 2×2 factorial ...design. Setting: 267 hospitals in 19 countries. Participants: 9297 patients with vascular disease or diabetes plus an additional risk factor, followed for 4.5 years as part of the HOPE study. Outcome measures: Stroke (confirmed by computed tomography or magnetic resonance imaging when available), transient ischaemic attack, and cognitive function. Blood pressure was recorded at entry to the study, after 2 years, and at the end of the study. Results: Reduction in blood pressure was modest (3.8 mm Hg systolic and 2.8 mm Hg diastolic). The relative risk of any stroke was reduced by 32% (156 v 226) in the ramipril group compared with the placebo group, and the relative risk of fatal stroke was reduced by 61% (17 v 44). Benefits were consistent across baseline blood pressures, drugs used, and subgroups defined by the presence or absence of previous stroke, coronary artery disease, peripheral arterial disease, diabetes, or hypertension. Significantly fewer patients on ramipril had cognitive or functional impairment. Conclusion: Ramipril reduces the incidence of stroke in patients at high risk, despite a modest reduction in blood pressure. What is already known on this topic Treatment with aspirin and lowering blood pressure reduce the incidence of stroke What this study adds Ramipril, an angiotensin converting enzyme inhibitor, reduces strokes in patients at high risk whose blood pressure is not elevated, despite only a modest lowering of blood pressure The benefits are observed even when patients receive aspirin and other blood pressure lowering treatments
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BFBNIB, CMK, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Angiotensin-receptor blockers (ARBs) blunt progression of advanced diabetic nephropathy, but their long-term renal effects in other patients are not clear.
To examine the long-term renal effects of ...telmisartan versus placebo in adults at high vascular risk.
Randomized trial. Patients were randomly assigned by a central automated system between November 2001 and May 2004 and were followed until March 2008. Participants and investigators were blinded to intervention status.
Multicenter, multinational study.
5927 adults with known cardiovascular disease or diabetes with end-organ damage but without macroalbuminuria or heart failure who cannot tolerate angiotensin-converting enzyme inhibitors.
Telmisartan, 80 mg/d (n = 2954), or matching placebo (n = 2972) plus standard treatment for a mean of 56 months.
Composite renal outcome of dialysis or doubling of serum creatinine, changes in estimated glomerular filtration rate (GFR), and changes in albuminuria.
No important difference was found in the composite renal outcome with telmisartan (58 patients 1.96%) versus placebo (46 patients 1.55%) (hazard ratio, 1.29 95% CI, 0.87 to 1.89; P = 0.20). Among the telmisartan and placebo groups, 7 and 10 patients had dialysis and 56 and 36 patients had doubling of serum creatinine, respectively (hazard ratio, 1.59 CI, 1.04 to 2.41; P = 0.031). Albuminuria increased less with telmisartan than with placebo (32% CI, 23% to 41% vs. 63% CI, 52% to 76%; P < 0.001). Decreases in estimated GFR were greater with telmisartan than with placebo (mean change in estimated GFR, -3.2 mL/min per 1.73 m(2) SD, 18.3 vs. -0.26 mL/min per 1.73 m(2) SD, 18.0; P < 0.001).
Only 17 participants had dialysis.
In adults with vascular disease but without macroalbuminuria, the effects of telmisartan on major renal outcomes were similar to those of placebo.
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