2,372 research outputs found
Absolute Absorption and Dispersion in a Thermal Rb Vapour at High Densities and High Magnetic Fields.
No full textThis thesis presents a comparative study of the measured and calculated absolute absorption and dispersion properties of the Rb D lines through a dense thermal vapour in the absence and presence of an applied magnetic field. A detailed theoretical model valid in the weak-probe regime is calculated. The model uses a matrix representation of the atomic Hamiltonian including the magnetic field interaction for Rb in the completely uncoupled basis. Numerical diagonalisation allows the frequency detunings and transition strengths to be calculated. The lineshape of each transition is modelled as a Voigt profile, a convolution of the inhomogeneous and homogeneous profiles. The medium’s susceptibility is found by summing over all the electric-dipole-allowed transitions. For dense thermal vapours a modification to the homogeneous linewidth of each transition, which grows linearly with the number density of atoms, arises due to resonant dipole-dipole interactions between identical atoms in superpositions of the ground and excited terms. In the presence of an applied magnetic field we investigate the Stokes parameters of light propagating through a dense thermal vapour. For fields larger than 0.33 T we enter the hyperfine Paschen-Back regime on the Rb D lines. We present a compact optical isolator based on an atomic vapour, exploiting the spectral region of high transmission and large dispersion where we would normally expect absorption on the Rb D lines. Frequency up-conversion is shown in the fluorescence measurements over the visible and near infra-red regions for strong excitation. Low density transfer arises due to the energy-pooling effect between two identical atoms in their first excited terms. At
high densities resonant dipole-dipole interactions give rise to a threshold for the energy transfer. We characterise the threshold behaviour with increasing number density
Abstract ES4-1: Her2 testing - 2017 guidelines for HER2 testing
No full textAbstract
Currently the use of anti-HER2 directed therapy (HDT) is predicated on the identification of HER2-postive breast cancers. Immunohistochemistry (IHC) and in situ hybridization (ISH) are the most common (and FDA-approved methods) for detecting HER2-positive breast cancers. While IHC and ISH are generally robust testing modalities, both can be subject to various pre-analytic, analytic and post-analytic issues/problems. In response to these issues/problems, ASCO and CAP formed a joint HER2 Guideline Committee. The initial guidelines of this committee were released in 2007 and a first revision of the guidelines was released in 2013. Since 2013, additional issues with HER2 testing have arisen and the ASCO/CAP Committee will be releasing a second revision to the guidelines in late 2017 or early 2018. This educational presentation will discuss HER2 testing – with a focus on fluorescent in situ hybridization (FISH). It will outline the 2013 ASCO/CAP guidelines and describe some of the issues that have arisen with these guidelines. The presentation will conclude with a discussion of the pending 2017/2018 ASCO/CAP guidelines for HER2 testing.
Citation Format: Jenkins RB. Her2 testing - 2017 guidelines for HER2 testing [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr ES4-1.</jats:p
A treatment for allergic rhinitis: a view on the role of levocetirizine
No full textBackground: Allergic rhinitis is a significant public health concern in many developed countries. However, despite evidence for a significant impact on patients' quality of life (QoL) including sleep disruption and reduced daytime performance, allergic rhinitis remains under-managed and hence poorly controlled. This is largely owing to lack of knowledge about, and poor adherence to, established treatment guidelines.Scope: The panel considered available evidence and focused on four published studies on the second-generation antihistamine, levocetirizine. Three of these studies explored the clinical impact of levocetirizine in a broad range of different clinical settings.Findings: Levocetirizine demonstrated an increased benefit over other antihistamines in terms of a more durable antihistamine response: levocetirizine provided improved symptom relief at 24 hours compared to desloratadine or fexofenadine, two frequently prescribed second-generation antihistamines. Levocetirizine also maintained relief of the key symptoms of allergic rhinitis and improved patients' QoL over a treatment period of 6 months, in a real-life setting. The variable efficacy and durability of response of different antihistamines arise from differing modulatory effects on the H1-receptor. The speed of relief of symptoms with levocetirizine is supported by the pharmacokinetic data, which shows that steady state plasma concentrations are achieved in a shorter period of time than other second-generation histamines (additionally levocetirizine Tmax is reached in 0.9 h).Conclusion: These findings support both the short-term and long-term use of levocetirizine in the clinical management of allergic rhinitis. The World Health Organization (WHO) ARIA Guidelines (Allergic Rhinitis and its Impact on Asthma), recommend using a combination of a non-sedating antihistamine with a decongestant, or glucocorticosteroids for treating allergic rhinitis – with the order and combination of treatment depending on severity and duration of symptoms
Liquid structure of Rb-Hg alloys studied by neutron diffraction
No full textThe structures of liquid Rb–Hg alloys were studied as a function of composition by neutron diffraction. In the intermediate Rb concentration range, the obtained structure factors show a small prepeak, which may be an evidence of the formation of Hg polyanion units in liquids. The Reverse Monte Carlo (RMC) analysis was applied to separate the total radial distribution function into the corresponding partial radial distribution functions. Up to 10 at.% Rb, no obvious changes are found for the first peak position of the partial radial distribution functions of the Hg–Hg pair and that of the Hg–Rb pair. The first peak position between the Hg–Rb pairs increases above 20 at.% Rb. In addition to the first peak, a subpeak between Hg–Hg pairs can be seen in the large distance. At 60 at.% Rb, the nearest neighbor distance between Hg atoms shows the closest value in the concentration range studied. These results indicate that with the progress of charge transfer the solvation structure in the dilute Rb concentration range changes into the structure containing polyanions composed of Hg species
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Carbon stable isotope analysis of cereal remains as a way to reconstruct water availability: preliminary results
No full textReconstructing past water availability, both as rainfall and irrigation, is important to answer questions about the way society reacts to climate and its changes and the role of irrigation in the development of social complexity. Carbon stable isotope analysis of archaeobotanical remains is a potentially valuable method for reconstructing water availability. To further define the relationship between water availability and plant carbon isotope composition and to set up baseline values for the Southern Levant, grains of experimentally grown barley and sorghum were studied. The cereal crops were grown at three stations under five different irrigation regimes in Jordan. Results indicate that a positive but weak relationship exists between irrigation regime and total water input of barley grains, but no relationship was found for sorghum. The relationship for barley is site-specific and inter-annual variation was present at Deir ‘Alla, but not at Ramtha and Khirbet as-Samra
Fractional Edge Cover Number of Model RB
No full textModel RB is a random constraint satisfaction problem with a growing domain size, which exhibits exact phase transition phenomena. Many hard instances with planted solutions can be generated via Model RB, to be used as benchmarks for algorithmic competitions and researches. In the past, some structural parameters of constraint hypergraphs are analyzed to show hardness of Model RB, such as hinge width, decycling number, treewidth, and hypertree width. In this paper, one more structural parameter of constraint hypergraphs of Model RB, namely the fractional edge cover number, is analyzed. We show upper and lower bounds on the fractional edge cover number of Model RB. In particular, the fractional edge cover number of Model RB is shown to be asymptotically linear in the number of variables, like hinge width, decycling number, treewidth and hypertree width. These results together provide further evidences on the hardness of Model RB.EICPCI-S(ISTP)[email protected]
Immunohistochemical detection of EGFRvIII in high malignancy grade astrocytomas and evaluation of prognostic significance
No full textThe purpose of this study was to establish an accurate and accessible immunohistochemical (IHC) method for detecting vIII Egf receptor and to assess the prognostic significance of the method as applied to the detection of vIII in malignant astrocytomas. The accuracy of the method was determined by comparing vIII immunoreactivity in formalin-fixed and paraffin-embedded tumor sections versus RT-PCR results from the analysis of RNA extracted from corresponding frozen specimens. RT-PCR revealed vIII transcript in 18 of 44 cases in this series, and IHC analysis of matched formalin-fixed and paraffin-embedded sections showed EGFRvIII reactivity in each of these 18 tumors, as well as 1 additional tumor that was negative for vIII transcript. EGFR amplification was evident in all tumors expressing vIII; none of the 15 tumors lacking amplified EGFR were positive for vIII transcript or vIII protein. IHC analysis for vIII expression was next applied to a large series of anaplastic astrocytomas (AAs) and glioblastoma multiforme (GBMs) from clinical trial patients with complete follow-up and that had been previously examined by FISH for amplified EGFR. Among the GBMs, vIII detection by IHC was determined in 19 of 46 cases (41.3%) with EGFR amplification, and in only 3 of 59 tumors lacking amplified EGFR (5.1%). Among the AAs, vIII expression was observed in 3 of 14 cases with amplified EGFR (21.4%) and in 6 of 49 cases without EGFR amplification (12.2%). GBM and AA patient survival analysis as a function of vIII expression showed contrasting results, with vIII positivity having no association with survival among GBM patients (p = 0.84), but being highly associated with reduced survival among AA patients (p = 0.0016). This latter finding, though quite possibly a result of vIII's association with increasing AA patient age, suggests that vIII IHC will be useful for identifying and/or confirming the identity of malignant astrocytomas whose clinical behavior is consistent with that of GBM
Guidelines for the Management of inflammatory bowel disease in children in the United Kingdom
No full textMILLIMETER-WAVE SPECTROSCOPY OF COLD RB ATOMS
No full textAuthor Institution: Department of Physics, University of Virginia, McCormick Road, Charlottesville, Virginia 22903Cold Rb atoms were prepared by magneto-optical trap. Millimeter-wave has been used to drive nd to (n-2)f one-photon and nd to (n-1)g () two-photon transitions. Quantum defects of f and g states of Rb were calculated. Full analyses will be presented. }
Interpretation and the Problem of the Intention of the Author, by Burhanetir Tatar
No full textBurhanetir Tatar, Interpretation and the Problem of the Intention of the Author: H.G. Gadamer vs E.D. Hirsh, The Council for Research in Values and Philosophy, 199
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