3,940 research outputs found

    Phenomenological theory of cuprate superconductivity

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    Reasonably good agreement with the superconducting transitiontemperatures of the cuprate high‐T c superconductors can be obtained on the basis of an approximate phenomenological theory. In this theory, two criteria are used to calculate the superconducting transitiontemperature. One is that the quantum wavelength is of the order of the electron‐pair spacing. The other is that a fraction of the normal carriers exist as Cooper pairs at T c . The resulting simple equation for T c contains only two parameters: the normal carrier density and effective mass. We calculate specific transition temperatures for 12 cuprate superconductors

    Head and Neck Manifestations of Eosinophilic Granulomatosis with Polyangiitis: A Systematic Review.

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    OBJECTIVE: To conduct the first and only systematic review of the existing literature on head and neck manifestations of eosinophilic granulomatosis with polyangiitis to guide clinical decision making for the otolaryngologist. DATA SOURCES: PubMed, Cochrane Library, Scopus, and LILACS. REVIEW METHODS: A systematic review of the aforementioned sources was conducted per the PRISMA guidelines. RESULTS: From an initial 574 studies, 28 trials and reports were included, accounting for a total of 1175 patients with eosinophilic granulomatosis with polyangiitis. Among clinical and cohort studies, 48.0% to 96.0% of all included patients presented with head and neck manifestations. In a distinct group of patients detailed in case reports describing patients presenting with head and neck manifestations, patients on average fulfilled 4.6 diagnostic criteria per the American College of Rheumatology. Furthermore, 95.8% of reported cases were responsive to steroids, and 60% required additional therapy. CONCLUSION: Otolaryngologists are in a unique position for the early diagnosis and prevention of late complications of eosinophilic granulomatosis with polyangiitis. The American College of Rheumatology criteria should be relied on in the diagnostic workup. Close surveillance of these patients in a multidisciplinary fashion and with baseline complete blood counts, chest radiographs, and autoimmune laboratory tests is often necessary. Such patients with head and neck manifestations of the disease are nearly always responsive to steroids and often require additional immunosuppressive therapy or surgical intervention in cases of cranial neuropathies, temporal bone involvement, and refractory symptoms

    Near Infrared Surface Properties of the Two Intrinsically Brightest Minor Planets (90377) Sedna and (90482) Orcus

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    We present low resolution K band spectra taken at the Gemini 8 meter telescope of (90377) Sedna and (90482) Orcus (provisional designations 2003 VB12 and 2004 DW, respectively), currently the two minor planets with the greatest absolute magnitudes (i.e. the two most reflective minor planets). We place crude limits on the surface composition of these two bodies using a Hapke model for a wide variety of assumed albedos. The unusual minor planet (90377) Sedna was discovered on November 14, 2003 UT at roughly 90 AU with 1.6 times the heliocentric distance and perihelion distance of any other bound minor planet. It is the first solar system object discovered between the Kuiper Belt and the Oort Cloud, and may represent a transition population between the two. The reflectance spectrum of (90377) Sedna appears largely featureless at the current signal-to-noise ratio, suggesting a surface likely to be highly processed by cosmic rays. For large grain models (100 micron to 1 cm) we find that (90377) Sedna must have less than 70% surface fraction of water ice and less than 60% surface fraction of methane ice to 3 sigma confidence. Minor planet (90482) Orcus shows strong water ice absorption corresponding to less than 50% surface fraction for grain models 25 micron and larger. Orcus cannot have more than 30% of its surface covered by large (100 mm to 1 cm) methane grains to 3 sigma confidence.Comment: Accepted for publication in the Astrophysical Journa

    Building a Better Vector: The Manipulation of AAV Virions

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    This review will focus on research directed at manipulating the virion of adeno-associated virus (AAV) with the goals of circumventing the immune response of the virion, as well as retargeting the virus to specific cell types of interest. The use of five AAV serotypes for addressing questions of Ab neutralization, novel tropism, as well as providing natural templates for targeting by virion modification will be discussed

    Biphenotypic Sinonasal Sarcoma-Case Report and Review of Clinicopathological Features and Diagnostic Modalities.

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    Background Biphenotypic sinonasal sarcoma is a recently described malignancy showing dual differentiation with both myogenic and neural elements. Due to its histologic similarities to other sinonasal malignancies, it is a diagnostic challenge. Objective The main purpose of this article is to report a case of biphenotypic sinonasal sarcoma and to consolidate data and provide a comprehensive review regarding pathological differences between biphenotypic sarcoma and other sinonasal malignancies and diagnostic modalities used for biphenotypic sarcoma. Material and Methods A systematic review of all cases of biphenotypic sinonasal sarcoma was performed using electronic databases (PubMed and Medline). Data collected included age, gender, symptoms, sub-site of origin, immunophenotyping, metastasis, recurrence, treatment, duration of follow-up, and survival outcomes. Results Ninety-five cases of biphenotypic sarcoma were found with mean age at diagnosis of 52.36 years (range, 24-87 years). Female to male ratio was 2.27:1. Extra-sinonasal extension was present in 28%. Immunophenotyping revealed that S-100 and SMA (smooth muscle actin) were consistently positive, while SOX-10 was consistently negative. PAX3-MAML3 fusion [t (2; 4) (q35; q31.1)] was the most common genetic rearrangement. Surgical excision with or without adjuvant radiotherapy was the most frequent treatment modality used. Recurrence was observed in 32% of cases with follow-up. None of the cases reported metastasis. Three patients had died at the time of publication that included one case with intracranial extension. Conclusion Biphenotypic sarcoma is distinct sinonasal malignancy with unique clinicopathological features. Testing involving a battery of myogenic and neural immunomarkers is essential for diagnostic confirmation and is a clinically useful endeavor when clinical suspicion is high. © 2019 Georg Thieme Verlag KG Stuttgart. New York

    The Orbital and Absolute Magnitude Distributions of Main Belt Asteroids

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    We have developed a model-independent analytical method for debiasing the four-dimensional (a,e,i,H) distribution obtained in any asteroid observation program and have applied the technique to results obtained with the 0.9m Spacewatch Telescope. From 1992 to 1995 Spacewatch observed ~3740 deg^2 near the ecliptic and made observations of more than 60,000 asteroids to a limiting magnitude of V~21. The debiased semi-major axis and inclination distributions of Main Belt asteroids in this sample with 11.5<= H <16 match the distributions of the known asteroids with H <11.5. The absolute magnitude distribution was studied in the range 8< H <17.5. We have found that the set of known asteroids is complete to about absolute magnitudes 12.75, 12.25 and 11.25 in the inner, middle and outer regions of the belt respectively. The number distribution as a function of absolute magnitude cannot be represented by a single power-law (10^{alpha H}) in any region. We were able to define broad ranges in H in each part of the belt where alpha was nearly constant. Within these ranges of H the slope does not correspond to the value of 0.5 expected for an equilibrium cascade in self-similar collisions (Dohnanyi, 1971). The value of alpha varies with absolute magnitude and shows a `kink' in all regions of the belt for H~13. This absolute magnitude corresponds to a diameter ranging from about 8.5 to 12.5 km depending on the albedo or region of the belt.Comment: 33 pages, 6 figures, 6 tables. published in Icaru
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