130 research outputs found
Non-Abelian dynamics and heavy multiquarks, Steiner-tree confinement in hadron spectroscopy
A brief review is first presented of attempts to predict stable multiquark
states within current models of hadron spectroscopy. Then a model combining
flip-flop and connected Steiner trees is introduced and shown to lead to stable
multiquarks, in particular for some configurations involving several heavy
quarks and bearing exotic quantum numbers.Comment: 8 pages, 5 figures, Invited talk at the 21st European Conference on
Few-Body Problems in Physics, Salamanca, Spain, August 29th--September 3rd,
2010, to appear in the Proceedings, ed.~A.~Valcarce et al., to appear in
Few-Body Syste
A Polarization Pursuers' Guide
We calculate the detectability of the polarization of the cosmic microwave
background (CMB) as a function of the sky coverage, angular resolution, and
instrumental sensitivity for a hypothetical experiment. We consider the
gradient component of the polarization from density perturbations (scalar
modes) and the curl component from gravitational waves (tensor modes). We show
that the amplitude (and thus the detectability) of the polarization from
density perturbations is roughly the same in any model as long as the model
fits the big-bang-nucleosynthesis (BBN) baryon density and degree-scale
anisotropy measurements. The degree-scale polarization is smaller (and
accordingly more difficult to detect) if the baryon density is higher. In some
cases, the signal-to-noise for polarization (both from scalar and tensor modes)
may be improved in a fixed-time experiment with a smaller survey area.Comment: 18 pages, 6 figure
Calculation of the Ostriker-Vishniac Effect in Cold Dark Matter Models
We present a new derivation of the cosmic microwave background anisotropy
spectrum from the Ostriker-Vishniac effect for an open, flat, or closed
Universe, and calculate the anisotropy expected in cold dark-matter (CDM)
models. We provide simple semi-analytic fitting formulas for the Vishniac power
spectrum that can be used to evaluate the expected anisotropy in CDM models for
any arbitrary ionization history. In a flat Universe, CDM models normalized to
cluster abundances produce rms temperature anisotropies of 0.8--2.4 K on
arcminute angular scales for a constant ionization fraction of unity, whereas
an ionization fraction of 0.2 yields rms anisotropies of 0.3--0.8 K. In an
open and/or high-baryon-density Universe, the level of anisotropy is somewhat
higher. The signal in some of these models may be detectable with planned
interferometry experiments. The damping of the acoustic peaks in the
primary-anisotropy spectrum at degree angular scales depends primarily on the
optical depth and only secondarily on the epoch of reionization. On the other
hand, the amplitude of Ostriker-Vishniac anisotropies depends sensitively on
the epoch of reionization. Therefore, when combined with the estimate of the
reionization optical depth provided by maps of degree-scale anisotropies, the
Ostriker-Vishniac effect can provide a unique probe of the epoch of
reionization.Comment: 19 pages, 2 figures, Revtex. Phys. Rev. D, accepted. Final version to
be published, with minor changes to open universe scalin
Distinct Effects of Unfractionated Heparin versus Bivalirudin on Circulating Angiogenic Peptides
Background: Human studies of therapeutic angiogenesis, stem-cell, and progenitor-cell therapy have failed to demonstrate consistent clinical benefit. Recent studies have shown that heparin increases circulating levels of anti-angiogenic peptides. Given the widely prevalent use of heparin in percutaneous and surgical procedures including those performed as part of studies examining the benefit of therapeutic angiogenesis and cell-based therapy, we compared the effects of unfractionated heparin (UFH) on angiogenic peptides with those of bivalirudin, a relatively newer anticoagulant whose effects on angiogenic peptides have not been studied. Methodology/Principal Findings: We measured soluble fms-like tyrosine kinase-1 (sFLT1), placental growth factor (PlGF), vascular endothelial growth factor (VEGF), and soluble Endoglin (sEng) serum levels by enzyme linked immunosorbent assays (ELISA) in 16 patients undergoing elective percutaneous coronary intervention. Compared to baseline values, sFLT1 and PlGF levels increased by 26296313 % and 253654%, respectively, within 30 minutes of UFH therapy (p,0.01 for both; n = 8). VEGF levels decreased by 93.265 % in patients treated with UFH (p,0.01 versus baseline). No change in sEng levels were observed after UFH therapy. No changes in sFLT1, PlGF, VEGF, or sEng levels were observed in any patients receiving bivalirudin (n = 8). To further explore the direct effect of anticoagulation on circulating angiogenic peptides, adult, male wild-type mice received venous injections of clinically dosed UFH or bivalirudin. Compared to saline controls, sFLT1 an
The 2020 “WHO technical specifications for automated non-invasive blood pressure measuring devices with cuff”
High systolic blood pressure (BP) is the single leading modifiable risk factor for death worldwide. Accurate BP
measurement is the cornerstone for screening, diagnosis, and management of hypertension. Inaccurate BP measurement
is a leading patient safety challenge. A recent World Health Organization report has outlined the technical specifications
for automated noninvasive clinical BP measurement with cuff. The report is applicable to ambulatory, home, and office
devices used for clinical purposes. The report recommends that for routine clinical purposes, (1) automated devices be
used, (2) an upper arm cuff be used, and (3) that only automated devices that have passed accepted international accuracy
standards (eg, the International Organization for Standardization 81060-2; 2018 protocol) be used. Accurate measurement
also depends on standardized patient preparation and measurement technique and a quiet, comfortable setting. The World
Health Organization report provides steps for governments, manufacturers, health care providers, and their organizations
that need to be taken to implement the report recommendations and to ensure accurate BP measurement for clinical
purposes. Although, health and scientific organizations have had similar recommendations for many years, the World Health
Organization as the leading governmental health organization globally provides a potentially synergistic nongovernment
government opportunity to enhance the accuracy of clinical BP assessment.The 2020 “WHO Technical Specifications for Automated Non-Invasive Blood
Pressure Measuring Devices With Cuff” was supported financially by the World
Health Organization and Resolve to Save Lives. O. John is a recipient of Australia
University International Postgraduate Awards scholarship from University of New
South Wales, Sydney. T.M. Brady received support from Resolve to Save Lives,
which is funded by Bloomberg Philanthropies, the Bill and Melinda Gates Foundation,
and Gates Philanthropy.http://hyper.ahajournals.orgam2022School of Health Systems and Public Health (SHSPH
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
The effect of a preoperative subconjuntival injection of dexamethasone on blood–retinal barrier breakdown following scleral buckling retinal detachment surgery: a prospective randomized placebo-controlled double blind clinical trial
textabstractBackground: Blood-retinal barrier breakdown secondary to retinal detachment and retinal detachment repair is a factor in the pathogenesis of proliferative vitreoretinopathy (PVR). We wished to investigate whether an estimated 700 to 1000 ng/ml subretinal dexamethasone concentration at the time of surgery would decrease the blood-retinal barrier breakdown postoperatively. Methods: Prospective, placebo-controlled, double blind clinical trial. In 34 patients with rhegmatogenous retinal detachment scheduled for conventional scleral buckling retinal detachment surgery, a subconjunctival injection of 0.5 ml dexamethasone diphosphate (10 mg) or 0.5 ml placebo was given 5-6 hours before surgery. Differences in laser flare photometry (KOWA) measurements taken 1, 3 and 6 weeks after randomisation between dexamethasone and placebo were analysed using mixed model ANOVA, while correcting for the preoperative flare measurement. Results: Six patients did not complete the study, one because of recurrent detachment within 1 week, and five because they missed their postoperative laser flare visits. The use of dexamethasone resulted in a statistically significant decrease in laser flare measurements at the 1-week postoperative visit. Conclusion: The use of a preoperative subconjunctival injection of dexamethasone decreased 1-week postoperative blood-retina barrier breakdown in patients undergoing conventional scleral buckling retinal detachment surgery. This steroid priming could be useful as a part of a peri-operative regime that would aim at decreasing the incidence of PVR
Resolving the Cosmological Missing Energy Problem
Some form of missing energy may account for the difference between the
observed cosmic matter density and the critical density. Two leading candidates
are a cosmological constant and quintessence (a time-varying, inhomogenous
component with negative pressure). We show that an ideal, full-sky cosmic
background anisotropy experiment may not be able to distinguish the two, even
when non-linear effects due to gravitational lensing are included. Due to this
ambiguity, microwave background experiments alone may not determine the matter
density or Hubble constant very precisely. We further show that degeneracy may
remain even after considering classical cosmological tests and measurements of
large scale structure.Comment: 6 pages, Latex, 4 postscript figures; revised analysis to include
gravitational lensin
A phase II study evaluating neo-/adjuvant EIA chemotherapy, surgical resection and radiotherapy in high-risk soft tissue sarcoma
<p>Abstract</p> <p>Background</p> <p>The role of chemotherapy in high-risk soft tissue sarcoma is controversial. Though many patients undergo initial curative resection, distant metastasis is a frequent event, resulting in 5-year overall survival rates of only 50-60%. Neo-adjuvant and adjuvant chemotherapy (CTX) has been applied to achieve pre-operative cytoreduction, assess chemosensitivity, and to eliminate occult metastasis. Here we report on the results of our non-randomized phase II study on neo-adjuvant treatment for high-risk STS.</p> <p>Method</p> <p>Patients with potentially curative high-risk STS (size ≥ 5 cm, deep/extracompartimental localization, tumor grades II-III [FNCLCC]) were included. The protocol comprised 4 cycles of neo-adjuvant chemotherapy (EIA, etoposide 125 mg/m<sup>2 </sup>iv days 1 and 4, ifosfamide 1500 mg/m<sup>2 </sup>iv days 1 - 4, doxorubicin 50 mg/m<sup>2 </sup>day 1, pegfilgrastim 6 mg sc day 5), definitive surgery with intra-operative radiotherapy, adjuvant radiotherapy and 4 adjuvant cycles of EIA.</p> <p>Result</p> <p>Between 06/2005 and 03/2010 a total of 50 subjects (male = 33, female = 17, median age 50.1 years) were enrolled. Median follow-up was 30.5 months. The majority of primary tumors were located in the extremities or trunk (92%), 6% originated in the abdomen/retroperitoneum. Response by RECIST criteria to neo-adjuvant CTX was 6% CR (n = 3), 24% PR (n = 12), 62% SD (n = 31) and 8% PD (n = 4). Local recurrence occurred in 3 subjects (6%). Distant metastasis was observed in 12 patients (24%). Overall survival (OS) and disease-free survival (DFS) at 2 years was 83% and 68%, respectively. Multivariate analysis failed to prove influence of resection status or grade of histological necrosis on OS or DFS. Severe toxicities included neutropenic fever (4/50), cardiac toxicity (2/50), and CNS toxicity (4/50) leading to CTX dose reductions in 4 subjects. No cases of secondary leukemias were observed so far.</p> <p>Conclusion</p> <p>The current protocol is feasible for achieving local control rates, as well as OS and DFS comparable to previously published data on neo-/adjuvant chemotherapy in this setting. However, the definitive role of chemotherapy remains unclear in the absence of large, randomized trials. Therefore, the current regimen can only be recommended within a clinical study, and a possibly increased risk of secondary leukemias has to be taken into account.</p> <p>Trial registration</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01382030">NCT01382030</a>, EudraCT 2004-002501-72</p
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