123 research outputs found
Isotopic Scaling of Heavy Projectile Residues from the collisions of 25 MeV/nucleon 86Kr with 124Sn, 112Sn and 64Ni, 58Ni
The scaling of the yields of heavy projectile residues from the reactions of
25 MeV/nucleon 86Kr projectiles with 124Sn,112Sn and 64Ni, 58Nitargets is
studied. Isotopically resolved yield distributions of projectile fragments in
the range Z=10-36 from these reaction pairs were measured with the MARS recoil
separator in the angular range 2.7-5.3 degrees. The velocities of the residues,
monotonically decreasing with Z down to Z~26-28, are employed to characterize
the excitation energy. The yield ratios R21(N,Z) for each pair of systems are
found to exhibit isotopic scaling (isoscaling), namely, an exponential
dependence on the fragment atomic number Z and neutron number N. The isoscaling
is found to occur in the residue Z range corresponding to the maximum observed
excitation energies. The corresponding isoscaling parameters are alpha=0.43 and
beta=-0.50 for the Kr+Sn system and alpha=0.27 and beta=-0.34 for the Kr+Ni
system. For the Kr+Sn system, for which the experimental angular acceptance
range lies inside the grazing angle, isoscaling was found to occur for Z<26 and
N<34. For heavier fragments from Kr+Sn, the parameters vary monotonically,
alpha decreasing with Z and beta increasing with N. This variation is found to
be related to the evolution towards isospin equilibration and, as such, it can
serve as a tracer of the N/Z equilibration process. The present heavy-residue
data extend the observation of isotopic scaling from the intermediate mass
fragment region to the heavy-residue region. Such high-resolution mass
spectrometric data can provide important information on the role of isospin in
peripheral and mid-peripheral collisions, complementary to that accessible from
modern large-acceptance multidetector devices.Comment: 8 pages, 6 figures, submitted to Phys. Rev.
The rationale for heart team decision-making for patients with stable, complex coronary artery disease
Stable complex coronary artery disease can be treated with coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or medical therapy. Multidisciplinary decision-making has gained more emphasis over the recent years to select the most optimal treatment strategy for individual patients with stable complex coronary artery disease. However, the so-called 'Heart Team' concept has not been widely implemented. Yet, decision-making has shown to remain suboptimal; there is large variability in PCI-to-CABG ratios, which may predominantly be the consequence of physician-related factors that have raised concerns regarding overuse, underuse, and inappropriate selection of revascularization. In this review, we summarize these and additional data to support the statement that a multidisciplinary Heart Team consisting of at least a clinical/non-invasive cardiologist, interventional cardiologist, and cardiac surgeon, can together better analyse and interpret the available diagnostic evidence, put into context the clinical condition of the patient as well as consider individual preference and local expertise, and through shared decision-making with the patient can arrive at a most optimal joint treatment strategy recommendation for patients with stable co
First international new intravascular rigid-flex endovascular stent study (FINESS): Clinical and angiographic results after elective and urgent stent implantation
Objectives. The purpose of this study was to determine the feasibility, safety and efficacy of elective and urgent deployment of the new intravascular rigid-flex (NIR) stent in patients with coronary artery disease. Background. Stent implantation has been shown to be effective in the treatment of focal, new coronary stenoses and in restoring coronary flow after coronary dissection and abrupt vessel closure. However, currently available stents either lack flexibility, hindering navigation through tortuous arteries, or lack axial strength, resulting in suboptimal scaffolding of the vessel. The unique transforming multicellular design of the NIR stent appears to provide both longitudinal flexibility and radial strength. Methods. NIR stent implantation was attempted in 255 patients (341 lesions) enrolled prospectively in a multicenter international registry from December 1995 through March 1996. Nine-, 16- and 32-mm long NIR stents were manually crimped onto coronary balloons and deployed in native coronary (94%) and saphenous vein graft (6%) lesions. Seventy-four percent of patients underwent elective stenting for primary or restenotic lesions, 21% for a suboptimal angioplasty result and 5% for threatened or abrupt vessel closure. Fifty-two percent of patients presented with unstable angina, 48% had a previous myocardial infarction, and 45% had multivessel disease. Coronary lesions were frequently complex, occurring in relatively small arteries (mean [±SD] reference diameter 2.8 ± 0.6 mm). Patients were followed up for 6 months for the occurrence of major adverse cardiovascular events. Results. Stent deployment was accomplished in 98% of lesions. Mean minimal lumen diameter increased by 1.51 ± 0.51 mm (from 1.09 ± 0.43 mm before to 2.60 ± 0.50 mm after the procedure). Mean percent diameter stenosis decreased from 61 ± 13% before to 17 ± 7% after intervention. A successful interventional procedure with <50% diameter stenosis of all treatment site lesions and no major adverse cardiac events within 30 days occurred in 95% of patients. Event-free survival at 6 months was 82%. Ninety-four percent of surviving patients were either asymptomatic or had mild stable angina at 6 month follow-up. Conclusions. Despite unfavorable clinical and angiographic characteristics of the majority of patients enrolled, the acute angiographic results and early clinical outcome after NIR stent deployment were very promising. A prospective, randomized trial comparing the NIR stent with other currently available stents appears warranted
Atherosclerotic coronary lesions with inadequate compensatory enlargement have smaller plaque and vessel volumes: observations with three dimensional intravascular ultrasound in vivo.
OBJECTIVE: To compare vessel, lumen, and plaque volumes in atherosclerotic coronary lesions with inadequate compensatory enlargement versus lesions with adequate compensatory enlargement. DESIGN: 35 angiographically significant coronary lesions were examined by intravascular ultrasound (IVUS) during motorised transducer pullback. Segments 20 mm in length were analysed using a validated automated three dimensional analysis system. IVUS was used to classify les
Intracoronary gamma-radiation therapy after angioplasty inhibits recurrence in patients with in-stent restenosis
BACKGROUND: Treatment of in-stent restenosis presents a critical
limitation of intracoronary stent implantation. Ionizing radiation has
been shown to decrease neointimal formation within stents in animal models
and in initial clinical trials. We studied the effects of intracoronary
gamma-radiation therapy versus placebo on the clinical and angiographic
outcomes of patients with in-stent restenosis. METHODS AND RESULTS: One
hundred thirty patients with in-stent restenosis underwent successful
coronary intervention and were then blindly randomized to receive either
intracoronary gamma-radiation with (192)Ir (15 Gy) or placebo. Four
independent core laboratories blinded to the treatment protocol analyzed
the angiographic and intravascular ultrasound end points of restenosis.
Procedural success and in-hospital and 30-day complications were similar
among the groups. At 6 months, patients assigned to radiation therapy
required less target lesion revascularization and target vessel
revascularization (9 [13.8%] and 17 [26.2%], respectively) compared with
patients assigned to placebo (41 [63.1%, P=0.0001] and 44 [67.7%,
P=0.0001], respectively). Binary angiographic restenosis was lower in the
irradiated group (19% versus 58% for placebo, P=0.001). Freedom from major
cardiac events was lower in the radiation group (29.2% versus 67.7% for
placebo, P<0.001). CONCLUSIONS: Intracoronary gamma-radiation used as
adjunct therapy for patients with in-stent restenosis significantly
reduces both angiographic and clinical restenosis
Variable Modified Chaplygin Gas in Anisotropic Universe with Kaluza-Klein Metric
In this work, we have consider Kaluza-Klein Cosmology for anisotropic
universe where the universe is filled with variable modified chaplygin gas
(VMCG). Here we find normal scalar field and the self interacting
potential to describe the VMCG Cosmology. Also we graphically
analyzed the geometrical parameters named {\it statefinder parameters} in
anisotropic Kaluza-Klein model. Next, we consider a Kaluza-Klein model of
interacting VMCG with dark matter in the Einstein gravity framework. Here we
construct the three dimensional autonomous dynamical system of equations for
this interacting model with the assumption that the dark energy and the dark
matter are interact between them and for that we also choose the interaction
term. We convert that interaction terms to its dimensionless form and perform
stability analysis and solve them numerically. We obtain a stable scaling
solution of the equations in Kaluza-Klein model and graphically represent
solutions.Comment: 11 pages, 13 figure
Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies
Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data
Defining high bleeding risk in patients undergoing percutaneous coronary intervention: a consensus document from the Academic Research Consortium for High Bleeding Risk
Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance,
but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic
Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities,
and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention–related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of
the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the
pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on
review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic
approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention
Defining High Bleeding Risk in Patients Undergoing Percutaneous Coronary Intervention A Consensus Document From the Academic Research Consortium for High Bleeding Risk
Identification and management of patients at high bleeding
risk undergoing percutaneous coronary intervention are of major
importance, but a lack of standardization in defining this population
limits trial design, data interpretation, and clinical decision-making.
The Academic Research Consortium for High Bleeding Risk (ARC-HBR)
is a collaboration among leading research organizations, regulatory
authorities, and physician-scientists from the United States, Asia, and
Europe focusing on percutaneous coronary intervention–related bleeding.
Two meetings of the 31-member consortium were held in Washington,
DC, in April 2018 and in Paris, France, in October 2018. These meetings
were organized by the Cardiovascular European Research Center on
behalf of the ARC-HBR group and included representatives of the US
Food and Drug Administration and the Japanese Pharmaceuticals and
Medical Devices Agency, as well as observers from the pharmaceutical
and medical device industries. A consensus definition of patients at high
bleeding risk was developed that was based on review of the available
evidence. The definition is intended to provide consistency in defining this
population for clinical trials and to complement clinical decision-making
and regulatory review. The proposed ARC-HBR consensus document
represents the first pragmatic approach to a consistent definition of
high bleeding risk in clinical trials evaluating the safety and effectiveness
of devices and drug regimens for patients undergoing percutaneous
coronary intervention
(Anti-)deuteron production in pp collisions at 1as=13TeV
The study of (anti-)deuteron production in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper the production of (anti-)deuterons is studied as a function of the charged particle multiplicity in inelastic pp collisions at s=13 TeV using the ALICE experiment. Thanks to the large number of accumulated minimum bias events, it has been possible to measure (anti-)deuteron production in pp collisions up to the same charged particle multiplicity (d Nch/ d \u3b7 3c 26) as measured in p\u2013Pb collisions at similar centre-of-mass energies. Within the uncertainties, the deuteron yield in pp collisions resembles the one in p\u2013Pb interactions, suggesting a common formation mechanism behind the production of light nuclei in hadronic interactions. In this context the measurements are compared with the expectations of coalescence and statistical hadronisation models (SHM)
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