848 research outputs found
Hypofractionated or Conventionally Fractionated Adjuvant Radiotherapy After Regional Lymph Node Dissection for High-Risk Stage III Melanoma
Aims: Adjuvant radiotherapy can be beneficial after regional lymph node dissection for high-risk stage III melanoma, as it has been shown to reduce the risk of recurrence in the node field. However, the optimal fractionation schedule is unknown and both hypofractionated and conventionally fractionated adjuvant radiotherapy are used. The present study examined the oncological outcomes of these two approaches in patients treated in an era before effective systemic immunotherapy became available. Materials and methods: This retrospective cohort study involved 335 patients with stage III melanoma who received adjuvant radiotherapy after therapeutic regional lymph node dissection for metastatic melanoma between 1990 and 2011. Information on tumour characteristics, radiotherapy doses and fractionation schedules and patient outcomes was retrieved from the institution's database and patients' medical records. Results: Hypofractionated radiotherapy (median dose 33 Gy in six fractions over 3 weeks) was given to 95 patients (28%) and conventionally fractionated radiotherapy (median dose 48 Gy in 20 fractions over 4 weeks) to 240 patients (72%). Five-year lymph node field control rates were 86.0% (95% confidence interval 78.4â94.4%) for the hypofractionated group and 85.5% (95% confidence interval 80.5â90.7%) for the conventional fractionation group (P = 0.87). There were no significant differences in recurrence-free survival (RFS) (41.7%, 95% confidence interval 32.5â53.5 versus 31.9%, 95% confidence interval 26.1â38.9; P = 0.18) or overall survival (41.2%, 95% confidence interval 32.1â52.8 versus 45.0%, 95% confidence interval 38.7â52.4; P = 0.77). On multivariate analysis, extranodal spread was associated with decreased RFS (P = 0.04) and the number of resected lymph nodes containing metastatic melanoma was associated with decreased RFS (P = 0.0006) and overall survival (P = 0.01). Conclusion: Lymph node field control rates, RFS and overall survival were similar after hypofractionated and conventionally fractionated adjuvant radiotherapy. The presence of extranodal spread and an increasing number of positive lymph nodes were predictive of an unfavourable outcome
The Case for Quantum Key Distribution
Quantum key distribution (QKD) promises secure key agreement by using quantum
mechanical systems. We argue that QKD will be an important part of future
cryptographic infrastructures. It can provide long-term confidentiality for
encrypted information without reliance on computational assumptions. Although
QKD still requires authentication to prevent man-in-the-middle attacks, it can
make use of either information-theoretically secure symmetric key
authentication or computationally secure public key authentication: even when
using public key authentication, we argue that QKD still offers stronger
security than classical key agreement.Comment: 12 pages, 1 figure; to appear in proceedings of QuantumComm 2009
Workshop on Quantum and Classical Information Security; version 2 minor
content revision
VOC amounts in ambient areas of a high-technology science park in Taiwan: their reciprocal correlations and impact on inhabitants
This study presents bihourly, seasonal, and yearly concentration changes in volatile organic compounds (VOCs) in the inlet and effluent water of the wastewater treatment plant (WWTP) of a high-technology science park (HTIP) in Taiwan, with the VOC amounts at different sites correlated geologically. This research adopted a combination of two systems, solid-phase microextraction with a gas chromatography/flame ionization detector and an assembly of purge and trap coupled with gas chromatography/mass spectrometry, to monitor polar and nonpolar VOCs in wastewater. This paper investigated the total VOCs, acetone, isopropyl alcohol (IPA), and dimethylsulfide (DMS) concentrations in real water samples collected in the ambient area of the HTIP. The major contents of VOCs measured in the effluent of the WWTP in the HTIP and the surrounding river region were DMS (14-176 ppb), acetone (5-95 ppb), and IPA (15-316 ppb). In comparison with the total VOCs in the inlet wastewater of the WWTP, no corresponding relationship for total VOC concentration in the wastewater was observed between the inlet water and effluent water of the WWTP. The peak VOC concentrations appeared in the third season, and the correlation of different VOC amounts reflects the production situation of the factories. In addition, VOC concentrations at different sites indicate that the Ke-Ya River is seemingly an effective channel for transporting wastewater to its final destination. The data are good indications for the management of environmental pollution near the HTIP
Adjuvant radiotherapy after salvage surgery for melanoma recurrence in a node field following a previous lymph node dissection
Background and Objectives: Adjuvant radiotherapy (RT) can be given to melanoma patients following salvage surgery for node field recurrence after a previous regional node dissection, but the value of this treatment strategy is poorly documented. This study evaluated long-term node field control and survival of patients treated in this way in an era before effective adjuvant systemic therapy became available. Methods: Data for 76 patients treated between 1990 and 2011 were extracted from an institutional database. Baseline patient characteristics, treatment details and oncological outcomes were analysed. Results: Adjuvant RT with conventional fractionation (median dose 48 Gy in 20 fractions) was given to 43 patients (57%) and hypofractionated RT (median dose 33 Gy in 6 fractions) to 33 patients (43%). The 5-year node field control rate was 70%, 5-year recurrence-free survival 17%, 5-year melanoma-specific survival 26% and 5-year overall survival 25%. Conclusions: Salvage surgery with adjuvant RT achieved node field control in 70% of melanoma patients with node field recurrence following a prior node dissection. However, disease progression at distant sites was common and survival outcomes were poor. Prospective data will be required to assess outcomes for contemporary combinations of surgery, adjuvant RT and systemic therapy.</p
Finite Element Simulation of Dense Wire Packings
A finite element program is presented to simulate the process of packing and
coiling elastic wires in two- and three-dimensional confining cavities. The
wire is represented by third order beam elements and embedded into a
corotational formulation to capture the geometric nonlinearity resulting from
large rotations and deformations. The hyperbolic equations of motion are
integrated in time using two different integration methods from the Newmark
family: an implicit iterative Newton-Raphson line search solver, and an
explicit predictor-corrector scheme, both with adaptive time stepping. These
two approaches reveal fundamentally different suitability for the problem of
strongly self-interacting bodies found in densely packed cavities. Generalizing
the spherical confinement symmetry investigated in recent studies, the packing
of a wire in hard ellipsoidal cavities is simulated in the frictionless elastic
limit. Evidence is given that packings in oblate spheroids and scalene
ellipsoids are energetically preferred to spheres.Comment: 17 pages, 7 figures, 1 tabl
Trends in sexually transmitted infections in united states ambulatory care clinics from 2005â2016
We examined the prevalence trends of non-human immunodeficiency virus (HIV) sexually transmitted infections (STI) and associated patient characteristics in U.S. ambulatory-care settings from 2005â2016. We conducted a retrospective repeated cross-sectional analysis using data from the National Ambulatory Medical Care Survey (NAMCS) for individuals aged 15â64 with a non-HIV STI-related visit. Data were combined into three periods (2005â2008, 2009â2012, and 2013â2016) to obtain reliable estimates. Logistic regression was used for analysis. A total of 19.5 million weighted, non-HIV STI-related ambulatory visits from 2005â2016 were identified. STI-related visits per 100,000 ambulatory care visits increased significantly over the study period: 206 (95% CI = 153â259), 343 (95% CI = 279â407), and 361 (95% CI = 277â446) in 2005â2008, 2009â2012, and 2013â2016, respectively (Ptrend = 0.003). These increases were mainly driven by increases in HPV-related visits (56 to 163 per 100,000 visits) from 2005â2008 to 2009â2012, followed by syphilis-or gonorrhea-related visits (30 to 67 per 100,000 visits) from 2009â2012 to 2013â2016. Higher odds of having STI-related visit were associated with younger age (aged 15â24: aOR = 4.45; 95% CI = 3.19â6.20 and aged 25â44: aOR = 3.59; 95% CI = 2.71â4.77) vs. 45â64-year-olds, Black race (aOR = 2.41; 95% CI = 1.78â3.25) vs. White, and HIV diagnosis (aOR = 10.60; 95% CI = 5.50â20.27) vs. no HIV diagnosis. STI-related office visits increased by over 75% from 2005â2016, and were largely driven by HPV-related STIs and syphilis-or gonorrhea-related STIs
Patient reported barriers are associated with low physical and mental well-being in patients with co-morbid diabetes and chronic kidney disease
BACKGROUND:Little is known about how patient reported barriers to health care impact the quality of life (HRQoL) of patients with comorbid disease. We investigated patient reported barriers to health care and low physical and mental well-being among people with diabetes and chronic kidney disease (CKD). METHODS:Adults with diabetes and CKD (estimated Glomerular Filtration Rateâ<â60 ml/min/1.73m2) were recruited and completed a questionnaire on barriers to health care, the 12-Item HRQoL Short Form Survey and clinical assessment. Low physical and mental health status were defined as mean scores <â50. Logistic regression models were used. RESULTS:Three hundred eight participants (mean age 66.9â±â11 years) were studied. Patient reported 'impact of the disease on family and friends' (OR 2.07; 95% CI 1.14 to 3.78), 'feeling unwell' (OR 4.23; 95% CI 1.45 to 12.3) and 'having other life stressors that make self-care a low priority' (OR 2.59; 95% CI 1.20 to 5.61), were all associated with higher odds of low physical health status. Patient reported 'feeling unwell' (OR 2.92; 95% CI 1.07 to 8.01), 'low mood' (OR 2.82; 95% CI 1.64 to 4.87) and 'unavailability of home help' (OR 1.91; 95% CI 1.57 to 2.33) were all associated with higher odds of low mental health status. The greater the number of patient reported barriers the higher the odds of low mental health but not physical health status. CONCLUSIONS:Patient reported barriers to health care were associated with lower physical and mental well-being. Interventions addressing these barriers may improve HRQoL among people with comorbid diabetes and CKD.Edward Zimbudzi, Clement Lo, Sanjeeva Ranasinha, Gregory Fulcher, Martin Gallagher, Stephen Jan, Peter G. Kerr, Helena J. Teede, Kevan R. Polkinghorne, Grant Russell, Rowan G. Walker, and Sophia Zounga
The ANTARES Optical Beacon System
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It
consists of a three dimensional array of photomultiplier tubes that can detect
the Cherenkov light induced by charged particles produced in the interactions
of neutrinos with the surrounding medium. High angular resolution can be
achieved, in particular when a muon is produced, provided that the Cherenkov
photons are detected with sufficient timing precision. Considerations of the
intrinsic time uncertainties stemming from the transit time spread in the
photomultiplier tubes and the mechanism of transmission of light in sea water
lead to the conclusion that a relative time accuracy of the order of 0.5 ns is
desirable. Accordingly, different time calibration systems have been developed
for the ANTARES telescope. In this article, a system based on Optical Beacons,
a set of external and well-controlled pulsed light sources located throughout
the detector, is described. This calibration system takes into account the
optical properties of sea water, which is used as the detection volume of the
ANTARES telescope. The design, tests, construction and first results of the two
types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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