1,347 research outputs found

    Quasi-Exact Solvability and the direct approach to invariant subspaces

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    We propose a more direct approach to constructing differential operators that preserve polynomial subspaces than the one based on considering elements of the enveloping algebra of sl(2). This approach is used here to construct new exactly solvable and quasi-exactly solvable quantum Hamiltonians on the line which are not Lie-algebraic. It is also applied to generate potentials with multiple algebraic sectors. We discuss two illustrative examples of these two applications: an interesting generalization of the Lam\'e potential which posses four algebraic sectors, and a quasi-exactly solvable deformation of the Morse potential which is not Lie-algebraic.Comment: 17 pages, 3 figure

    Disease Activity and Progression in Multiple Sclerosis: New Evidences and Future Perspectives

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    Multiple sclerosis (MS) is a chronic, debilitating, autoimmune-mediated, inflammatory disease of the central nervous system (CNS), in which a combination of inflammation, demyelination and axonal degeneration takes place with extreme highly interpersonal variability [...]

    Stress Hyperglycemia Does Not Affect Clinical Outcome of Diabetic Patients Receiving Intravenous Thrombolysis for Acute Ischemic Stroke

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    Although stress hyperglycemia represents a main risk factor for poor outcome among patients with acute ischemic stroke (AIS) undergoing recanalization therapy, we have limited information regarding a possible influence of the premorbid diabetic status on this association. We recruited consecutive patients admitted to the Udine University Hospital with AIS who were treated with intravenous thrombolysis (IVT) from January 2015 to September 2020. On the basis of the premorbid diabetic status, our sample was composed of 130 patients with and 371 patients without diabetes. The glucose-to-glycated hemoglobin ratio (GAR) was used to measure stress hyperglycemia. Patients were stratified into 3 groups by tertiles of GAR (Q1–Q3). The higher GAR index was, the more severe stress hyperglycemia was considered. Among diabetic patients we did not observe any significant association between severe stress hyperglycemia and outcome measures (three-month poor outcome: Q1, 53.7%; Q2, 53.5%; Q3, 58.7%; p = 0.854; three-month mortality: Q1, 14.6%; Q2, 9.3%; Q3, 23.9%; p = 0.165; symptomatic intracranial hemorrhage: Q1, 7.3%; Q2, 14%; Q3, 19.6%; p = 0.256). Differently, non-diabetic subjects with more severe stress hyperglycemia showed a higher prevalence of three-month poor outcome (Q1, 32.2%; Q2, 27.7%; Q3, 60.3%; p = 0.001), three-month mortality (Q1, 9.1%; Q2, 8.4%; Q3, 18.3%; p = 0.026), and symptomatic intracranial hemorrhage (Q1, 0.8%; Q2, 0.8%; Q3, 9.9; p = 0.001). After controlling for several confounders, severe stress hyperglycemia remained a significant predictor of three-month poor outcome (OR 2.1, 95% CI 1.03–4.28, p = 0.041), three-month mortality (OR 2.39, 95% CI 1.09–5.26, p = 0.029) and symptomatic intracranial hemorrhage (OR 12.62, 95% CI 1.5–106, p = 0.02) among non-diabetics. In conclusion, premorbid diabetic status seems to influence outcome in AIS patients receiving IVT. Indeed, odds of functional dependency, mortality and hemorrhagic complications were significantly increased in patients with more severe stress hyperglycemia only when they were not affected by diabetes

    Impact of Disease-Modifying Therapies on Gut–Brain Axis in Multiple Sclerosis

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    Multiple sclerosis is a chronic, autoimmune-mediated, demyelinating disease whose pathogenesis remains to be defined. In past years, in consideration of a constantly growing number of patients diagnosed with multiple sclerosis, the impacts of different environmental factors in the pathogenesis of the disease have been largely studied. Alterations in gut microbiome composition and intestinal barrier permeability have been suggested to play an essential role in the regulation of autoimmunity. Thus, increased efforts are being conducted to demonstrate the complex interplay between gut homeostasis and disease pathogenesis. Numerous results confirm that disease-modifying therapies (DMTs) used for the treatment of MS, in addition to their immunomodulatory effect, could exert an impact on the intestinal microbiota, contributing to the modulation of the immune response itself. However, to date, the direct influence of these treatments on the microbiota is still unclear. This review intends to underline the impact of DMTs on the complex system of the microbiota–gut–brain axis in patients with multiple sclerosis

    Recanalisation theraphy for acute ischemic stroke in cancer patients

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    To date, very few studies focused their attention on efficacy and safety of recanalisation therapy in acute ischemic stroke (AIS) patients with cancer, reporting conflicting results. We retrospectively analysed data from our database of consecutive patients admitted to the Udine University Hospital with AIS that were treated with recanalisation therapy, i.e. intravenous thrombolysis (IVT), mechanical thrombectomy (MT), and bridging therapy, from January 2015 to December 2019. We compared 3-month dependency, 3-month mortality, and symptomatic intracranial haemorrhage (SICH) occurrence of patients with active cancer (AC) and remote cancer (RC) with that of patients without cancer (WC) undergoing recanalisation therapy for AIS. Patients were followed up for 3\ua0months. Among the 613 AIS patients included in the study, 79 patients (12.9%) had either AC (n = 46; 7.5%) or RC (n = 33; 5.4%). Although AC patients, when treated with IVT, had a significantly increased risk of 3-month mortality [odds ratio (OR) 6.97, 95% confidence interval (CI) 2.42\u201320.07, p = 0.001] than WC patients, stroke-related deaths did not differ between AC and WC patients (30% vs. 28.8%, p = 0.939). There were no significant differences between AC and WC patients, when treated with MT \ub1 IVT, regarding 3-month dependency, 3-month mortality and SICH. Functional independence, mortality, and SICH were similar between RC and WC patients. In conclusion, recanalisation therapy might be used in AIS patients with nonmetastatic AC and with RC. Further studies are needed to explore the outcome of AIS patients with metastatic cancer undergoing recanalisation therapy

    The use of alteplase, although safe, does not offer clear clinical advantages when mild stroke is non-disabling

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    Introduction: It is unknown whether alteplase is effective and safe in patients with mild acute ischemic stroke (AIS). Determining whether symptoms are “disabling” or not is a crucial factor in the management of these patients. This study aimed to investigate the efficacy and safety of alteplase in patients with mild, non-disabling AIS. Methods: We included all consecutive patients admitted for AIS at our institution from January 2015 to May 2022 who presented a baseline NIHSS score of 0–5 and fit the criteria to receive intravenous thrombolysis. In order to select only subjects with non-disabling AIS, we excluded patients who scored more than 1 point in the following NIHSS single items: vision, language, neglect, and single limb. Patients who scored at least 1 point in the NIHSS consciousness item were excluded as well. This study is a retrospective analysis of a prospectively collected database. Results: After the application of the exclusion criteria, we included 319 patients, stratified into patients receiving and not receiving alteplase based on non-disabling symptoms. The two groups were comparable regarding demographic and clinical data. Rates of a 3-month favorable outcome, defined as a 3-month mRS score of 0–1, were similar, being 82.3% and 86.1% in the treated and untreated patients, respectively. Hemorrhagic complications and mortality occurred infrequently and were not affected by alteplase treatment. Discussion: This observational study suggests that the use of alteplase, although safe, is not associated with a better outcome in highly selected patients with non-disabling AIS

    Experiencia religiosa en ambientes virtuales de aprendizaje.

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    El art?culo es resultado del proyecto de investigaci?n ?Cartograf?a social de la experiencia religiosa en los ambientes virtuales de aprendizaje? , que desde una perspectiva anal?tica, aborda el mapeo de los espacios virtuales de aprendizaje, que a su vez, son referentes ciberespaciales en los cuales se construye la red-comunidad de aprendizaje, y se expresan las m?ltiples vivencias humanas y religiosas, desde el estilo cristiano de presencia en el mundo digital. El an?lisis fue orientado desde el procedimiento metodol?gico teol?gico (texto, contexto, pretexto), se utiliz? la t?cnica de la cartograf?a social, as? como las herramientas e instrumentos tecnol?gicos propios de los ambientes virtuales de aprendizaje, y los mapas colectivos de las experiencias humanas y religiosas, en el espacio y la red- comunidad virtual de aprendizaje de la Licenciatura en Ciencias Religiosas, Facultad de Teolog?a. Pontificia Universidad Javeriana

    ZrO2 Based materials as photocatalysts for 2-propanol oxidation by using UV and solar light irradiation and tests for CO2 reduction

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    Bare ZrO2, Ce doped ZrO2 and Er doped ZrO2 samples have been prepared by a hydrothermal process and have been used as photocatalysts for 2-propanol oxidation reaction in gas solid regime. Moreover, some preliminary tests have been carried out for CO2 reduction. The samples were physico-chemically characterized and both bare and doped ZrO2 based materials resulted active for oxidation and reduction reactions by using UV and solar irradiation. The reactivity results have been correlated with the compositional, structural and morphological features of the photocatalysts

    Oscillatons revisited

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    In this paper, we study some interesting properties of a spherically symmetric oscillating soliton star made of a real time-dependent scalar field which is called an oscillaton. The known final configuration of an oscillaton consists of a stationary stage in which the scalar field and the metric coefficients oscillate in time if the scalar potential is quadratic. The differential equations that arise in the simplest approximation, that of coherent scalar oscillations, are presented for a quadratic scalar potential. This allows us to take a closer look at the interesting properties of these oscillating objects. The leading terms of the solutions considering a quartic and a cosh scalar potentials are worked in the so called stationary limit procedure. This procedure reveals the form in which oscillatons and boson stars may be related and useful information about oscillatons is obtained from the known results of boson stars. Oscillatons could compete with boson stars as interesting astrophysical objects, since they would be predicted by scalar field dark matter models.Comment: 10 pages REVTeX, 10 eps figures. Updated files to match version published in Classical and Quantum Gravit

    Meningioma-Related Epilepsy: A Happy Ending?

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    (1) Background: More than one-third of patients with meningiomas experience at least one seizure during the course of their disease, and in the 20–50% of cases, seizure represents the onset symptom. After surgery, up to 30% of patients continue to have seizures, while others may experience them later; (2) Methods: The study analyzed retrospectively the risk factors for pre-operative seizures in a large cohort of 358 patients who underwent surgery for newly diagnosed brain meningioma; (3) Results: We identified age, peritumor edema, and location as risk factors for seizure at the onset. Patients with seizures differed from patients without seizures for the following characteristics: younger average age, lower pre-operative Karnofsky Performance Status (KPS), location on the convexity, lower Simpson Grade, lower incidence of pre-operative neurological deficits, and higher incidence of pre-operative peritumor edema. After 24 months, 88.2% of patients were classified as Engel class Ia, and no correlation with disease progression was observed; (4) Conclusions: Meningioma-related epilepsy has generally a positive outcome following surgery and it seems not to be linked to disease progression, even if further studies are needed
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