2,418 research outputs found
Fatigue and TSH Levels in Hypothyroid Patients
Background. Fatigue is often the complaint that initiates thyroid function investigation. Most available data related to fatigue and hypothyroidism involved patients with subclinical hypothyroidism where fatigue was not the primary outcome. This study investigated the association between TSH levels and fatigue and if there was a target TSH interval that was associated with lower incidence of fatigue in patients with hypothyroidism. Methods. An analytic, retrospective cohort study design assessed the relationship between TSH levels and fatigue. All adult patients at one endocrinology clinic who were diagnosed with hypothyroidism between January 1, 2006 and December 31, 2007 were included. Diagnoses were confirmed by biochemical testing. Data were abstracted from the clinic’s electronic medical record. Fatigue status was self-reported by the subject during examination by the endocrinologist. Fatigue status and TSH levels were obtained twice: at diagnosis and during the first follow-up visit. Results. A total of 135 patients met the inclusion criteria. After treatment, all patients had reductions in TSH levels. Those subjects reporting relief from fatigue tended to be males (p = 0.003), had lower TSH levels at follow-up (p < 0.001), had larger TSH differences from baseline (p =0.007), and had a primary diagnosis of acquired hypothyroidism (p < 0.001). Females were 2.9 times more likely to report persistent fatigue than males. Patients with primary diagnosis of thyroiditis were 3 times more likely to report persistent fatigue than those with acquired hypothyroidism. Conclusions. The observed relief from fatigue after treatment correlated with a higher TSH reduction compared to patients with persistent fatigue. It was unclear if fatigue relief was related to the level of TSH reduction (TSH difference) or to a lower absolute TSH level reached after treatment
Nature of exciton transitions in hexagonal boron nitride
Citation: Li, J., Cao, X. K., Hoffman, T. B., Edgar, J. H., Lin, J. Y., & Jiang, H. X. (2016). Nature of exciton transitions in hexagonal boron nitride. Applied Physics Letters, 108(12), 4. doi:10.1063/1.4944696In contrast to other III-nitride semiconductors GaN and AlN, the intrinsic (or free) exciton transition in hexagonal boron nitride (h-BN) consists of rather complex fine spectral features (resolved into six sharp emission peaks) and the origin of which is still unclear. Here, the free exciton transition (FX) in h-BN bulk crystals synthesized by a solution method at atmospheric pressure has been probed by deep UV time-resolved photoluminescence (PL) spectroscopy. Based on the separations between the energy peak positions of the FX emission lines, the identical PL decay kinetics among different FX emission lines, and the known phonon modes in h-BN, we suggest that there is only one principal emission line corresponding to the direct intrinsic FX transition in h-BN, whereas all other fine features are a result of phonon-assisted transitions. The identified phonon modes are all associated with the center of the Brillouin zone. Our results offer a simple picture for the understanding of the fundamental exciton transitions in h-BN. (C) 2016 AIP Publishing LLC
Implantation of a Novel Cryopreserved Viable Osteochondral Allograft for Articular Cartilage Repair in the Knee
Restoration and repair of articular cartilage injuries remain a challenge for orthopaedic surgeons. The standard first-line treatment of articular cartilage lesions is marrow stimulation; however, this procedure can often result in the generation of fibrous repair cartilage rather than the biomechanically superior hyaline cartilage. Marrow stimulation is also often limited to smaller lesions, less than 2 cm2. Larger lesions may require implantation of a fresh osteochondal allograft, though a short shelf life, size-matched donor requirements, potential challenges of bone healing, limited availability, and the relatively high price limit the wide use of this therapeutic approach. We present a straightforward, single-stage surgical technique of a novel reparative and restorative approach for articular cartilage repair with the implantation of a cryopreserved viable osteochondral allograft (CVOCA). The CVOCA contains full-thickness articular cartilage and a thin layer of subchondral bone, and maintains the intact native cartilage architecture with viable chondrocytes, growth factors, and extracellular matrix proteins to promote articular cartilage repair. We report the results of a retrospective case series of three patients who presented with articular cartilage lesions more than 2 cm2 and were treated with the CVOCA using the presented surgical technique. Patients were followed up to 2 years after implantation of the CVOCA and all three patients had satisfactory outcomes without adverse events. Controlled randomized studies are suggested for evaluation of CVOCA efficacy, safety, and long-term outcomes
Advancing the Practice: A Report of the US National Curator’s Committee Ethics Subcommittee on the 2014 Curatorial Survey and Core Competencies Projects
Alternately reviled and revered, curators retain an iconic role at the heart of museum activities. But what have they to do with museology? Curators are the intellectual, authoritative center of a traditional model whose very foundations have been destabilized by economic, technological and social change. The role of the curator is challenged by the reductive, linear thinking that has accompanied the rise in computer technology (Doueihi, 2011; Marty, 2008), the dependence on attendance and popularity that now determines user-centric operations (Janes, 2009; Mairesse, 2005; Tobelem, 2010), and a general post-structuralist, anti-intellectual attitude (Bauman, 1987; Cameron, 2010; Mason, 2006). Are curators then the last bastion of old-guard Enlightenment intellectuals, or a stop-gap for the dissolution of culture in the face of radical egalitarianism in the Digital Age? To elucidate realities of the evolving role of curators and their relationship with museology, this paper will summarize and juxtapose two major projects of CurCom, the US National Curator’s Committee. In tandem, these projects – a survey of the education, experience and training needs of CurCom members, and the elaboration of Curators’ Core Competencies – illustrate the expanding and significant challenges, functions, and duties faced by US curators and the applied skills that they must all possess to be successful. Though museologists are not curators, many of the crucial questions that arise within the field are strongly related to curatorial activity. If museology is to be more than just irrelevant theory and more adequately address the theoretical and practical elements that have destabilized the traditional models (Gob & Drouguet, 2010), we must evolve how it contributes to its adherents and practitioners. When crucial museum issues rest at the heart of curatorial activity, and there is little intersection of curators with museology, what is the hope for evolving the museum? The summary of these national projects in this international forum is intended to invite comparison and provoke conversation.TantĂ´t rĂ©cusĂ©s, tantĂ´t vĂ©nĂ©rĂ©s, les conservateurs jouent encore et toujours un rĂ´le emblĂ©matique au cĹ“ur des activitĂ©s musĂ©ales. Mais quel est leur rapport avec la musĂ©ologie ? Les conservateurs reprĂ©sentent le centre intellectuel, autoritaire, d’un modèle traditionnel dont les fondements mĂŞmes ont subi les bouleversements Ă©conomiques, technologiques et sociaux. Le rĂ´le du conservateur se trouve menacĂ© face au mode de pensĂ©e restrictif, linĂ©aire, qui s’est dĂ©veloppĂ© parallèlement Ă l’essor de la technologie informatique (Doueihi, 2011; Marty, 2008; Peacock, 2007), avec les opĂ©rations dĂ©sormais centrĂ©es sur l’utilisateur et axĂ©es essentiellement sur la frĂ©quentation et la popularitĂ© (Janes, 2009; Mairesse, 2005; Tobelem, 2010) et une attitude globalement post-structuraliste et anti-intellectuelle (Bauman, 1987; Cameron, 2010; Mason, 2006). Cela signifie-t-il que les conservateurs seraient les derniers remparts d’intellectuels des Lumières de la vieille garde ou une solution provisoire pour freiner la dissolution de la culture face Ă l’égalitarisme radical de l’ère du numĂ©rique ? Afin de mieux cerner quel est, rĂ©ellement, le rĂ´le des conservateurs, et essayer de dĂ©finir la relation importante en pleine transformation qu’ils entretiennent avec la musĂ©ologie, ce rapport prĂ©sentera deux projets majeurs menĂ©s par CurCom, le ComitĂ© national amĂ©ricain des conservateurs. L’un consiste en une enquĂŞte approfondie sur les besoins des membres de CurCom en expĂ©rience et formation, et l’autre en la dĂ©finition des compĂ©tences essentielles que doivent possĂ©der les conservateurs. Ces projets illustrent les rĂ´les et les tâches de plus en plus vastes qui incombent aux conservateurs ainsi que les dĂ©fis croissants auxquels ils sont confrontĂ©s, et les compĂ©tences pratiques qu’ils doivent possĂ©der pour rĂ©ussir dans leur carrière. Bien que les musĂ©ologues ne soient pas des conservateurs, un grand nombre des questions cruciales qui se posent dans ce domaine sont Ă©troitement liĂ©es Ă l’activitĂ© du conservateur. Si la musĂ©ologie doit ĂŞtre plus que de la thĂ©orie non pertinente, et rĂ©agir de manière plus adĂ©quate face aux Ă©lĂ©ments qui ont bouleversĂ© les modèles traditionnels (Gob & Drouguet, 2010), il nous faut chercher Ă comprendre ce qu’elle apporte Ă ses professionnels et ses praticiens. Si les questions musĂ©ales cruciales siègent au cĹ“ur de l’activitĂ© curatoriale, et qu’il existe peu de points de convergence entre les conservateurs et la musĂ©ologie, quel espoir peut-on alors avoir que le domaine des musĂ©es Ă©volueÂ
The Case of the Counterfeit Correlation: A Computer Simulation Illustrating a Common Error with the Use of Index Variables Including Per Capita Census Measures
The presented material is particularly directed to scholars who examine aggregate data i.e. index variables through the use of correlation techniques. As K. Pearson already demonstrated a substantial portion of the correlation between the underlying concepts but rather to the operation — division — by which the indices were created. He termed this correlation as »spurious« and demonstrated that it is due in part to the prior correlation of the variables forming the indices. Here we present a brief overview of the mathematics supporting the assertion of spuriousness and also the results of a computer simulation which we developed to demonstrate the dangers of the approach. Our simulations, hopefully, demonstrate that counterfeit correlations should be of practical concern to the researcher interested in actual applications and that correlating index variables is likely to lead to misleading conclusions because such correlations are counterfeit
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