366 research outputs found

    Radiological Significance of Ligamentum Flavum Hypertrophy in the Occurrence of Redundant Nerve Roots of Central Lumbar Spinal Stenosis

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    Objective: There were previous reports of redundant nerve roots (RNRs) focused on their clinical significance and pathogenesis. In this study, we investigated the significant radiologic findings that correlate with RNRs occurrence. These relations would provide an advanced clue for clinical significance and pathogenesis of RNRs. Methods: Retrospective research was performed with data from 126 patients who underwent surgery for central lumbar spinal stenosis (LSS). Finally, 106 patients with common denominators (inter-observer accuracy : 84%) were included on this study. We divided the patients into two groups by MRI, patients with RNRs and those with no RNRs (NRNRs). Comparative analyses were performed with clinical and radiologic parameters. Results: RNRs were found in 45 patients (42%) with central LSS. There were no statistically significant differences between the two groups in severity of symptoms. On the other hand, we found statistically significant differences in duration of symptom and number of level included (p<0.05). In the maximal stenotic level, ligamentum flavum (LF) thickness, LF cross-sectional area (CSA), dural sac CSA, and segmental angulation are significantly different in RNRs group compared to NRNRs group (p<0.05). Conclusion: RNRs patients showed clinically longer duration of symptoms and multiple levels included. We also confirmed that wide segmental angulation and LF hypertrophy play a major role of the development of RNRs in central LSS. Together, our results suggest that wide motion in long period contribute to LF hypertrophy, and it might be the key factor of RNRs formation in central LSS

    Allosteric Modulators of Steroid Hormone Receptors : Structural Dynamics and Gene Regulation

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    Peer reviewedPublisher PD

    Antiferroelectric negative capacitance from a structural phase transition in zirconia

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    Crystalline materials with broken inversion symmetry can exhibit a spontaneous electric polarization, which originates from a microscopic electric dipole moment. Long-range polar or anti-polar order of such permanent dipoles gives rise to ferroelectricity or antiferroelectricity, respectively. However, the recently discovered antiferroelectrics of fluorite structure (HfO2_2 and ZrO2_2) are different: A non-polar phase transforms into a polar phase by spontaneous inversion symmetry breaking upon the application of an electric field. Here, we show that this structural transition in antiferroelectric ZrO2_2 gives rise to a negative capacitance, which is promising for overcoming the fundamental limits of energy efficiency in electronics. Our findings provide insight into the thermodynamically 'forbidden' region of the antiferroelectric transition in ZrO2_2 and extend the concept of negative capacitance beyond ferroelectricity. This shows that negative capacitance is a more general phenomenon than previously thought and can be expected in a much broader range of materials exhibiting structural phase transitions

    Radio Location of Partial Discharge Sources: A Support Vector Regression Approach

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    Partial discharge (PD) can provide a useful forewarning of asset failure in electricity substations. A significant proportion of assets are susceptible to PD due to incipient weakness in their dielectrics. This paper examines a low cost approach for uninterrupted monitoring of PD using a network of inexpensive radio sensors to sample the spatial patterns of PD received signal strength. Machine learning techniques are proposed for localisation of PD sources. Specifically, two models based on Support Vector Machines (SVMs) are developed: Support Vector Regression (SVR) and Least-Squares Support Vector Regression (LSSVR). These models construct an explicit regression surface in a high dimensional feature space for function estimation. Their performance is compared to that of artificial neural network (ANN) models. The results show that both SVR and LSSVR methods are superior to ANNs in accuracy. LSSVR approach is particularly recommended as practical alternative for PD source localisation due to it low complexity

    Neural Stem Cells Engineered to Express Three Therapeutic Factors Mediate Recovery from Chronic Stage CNS Autoimmunity

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    © The American Society of Gene and Cell Therapy. Treatment of chronic neurodegenerative diseases such as multiple sclerosis (MS) remains a major challenge. Here we genetically engineer neural stem cells (NSCs) to produce a triply therapeutic cocktail comprising IL-10, NT-3, and LINGO-1-Fc, thus simultaneously targeting all mechanisms underlie chronicity of MS in the central nervous system (CNS): persistent inflammation, loss of trophic support for oligodendrocytes and neurons, and accumulation of neuroregeneration inhibitors. After transplantation, NSCs migrated into the CNS inflamed foci and delivered these therapeutic molecules in situ. NSCs transduced with one, two, or none of these molecules had no or limited effect when injected at the chronic stage of experimental autoimmune encephalomyelitis; cocktail-producing NSCs, in contrast, mediated the most effective recovery through inducing M2 macrophages/microglia, reducing astrogliosis, and promoting axonal integrity and endogenous oligodendrocyte/neuron differentiation. These engineered NSCs simultaneously target major mechanisms underlying chronicity of multiple sclerosis (MS) and encephalomyelitis (EAE), thus representing a novel and potentially effective therapy for the chronic stage of MS, for which there is currently no treatment available

    Exploring the linkages between managerial leadership, communication and teamwork in successful event delivery

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    Recent growth of events has triggered research into the determinants of successful event delivery. Communication is one of the determinants, and the importance of managerial leadership in enabling communication across an event's team is recognised. Empirical research on the attributes of event managers that make them good leaders from the perspective of an event's team is however limited. Through in-depth, semi-structured interviews with employees of an established events company in the UK, this study explores the role of managerial leadership in the success of an event, referring in particular to the enablers and inhibitors of effective communication. The study finds that leadership capacity of managers correlates with their personal and inter-personal competencies. On a personal level, poor motivational and interaction skills reduce the event's team performance. On an inter-personal level, insufficient recognition of the efforts applied by individual team members as well as the entire team serves as an inhibitor
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