262 research outputs found

    Predictors of positive health in disability pensioners: a population-based questionnaire study using Positive Odds Ratio

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    BACKGROUND: Determinants of ill-health have been studied far more than determinants of good and improving health. Health promotion measures are important even among individuals with chronic diseases. The aim of this study was to find predictors of positive subjective health among disability pensioners (DPs) with musculoskeletal disorders. METHODS: Two questionnaire surveys were performed among 352 DPs with musculoskeletal disorders. Two groups were defined: DPs with positive health and negative health, respectively. In consequence with the health perspective in this study the conception Positive Odds Ratio was defined and used in the logistic regression analyses instead of the commonly used odds ratio. RESULTS: Positive health was associated with age ≄ 55 years, not being an immigrant, not having fibromyalgia as the main diagnosis for granting an early retirement, no regular use of analgesics, a high ADL capacity, a positive subjective health preceding the study period, and good quality of life. CONCLUSION: Positive odds ratio is a concept well adapted to theories of health promotion. It can be used in relation to positive outcomes instead of risks. Suggested health promotion and secondary prevention efforts among individuals with musculoskeletal disorders are 1) to avoid a disability pension for individuals <55 years of age; if necessary, to make sure rehabilitation actions continue, 2) to increase efforts to support immigrants to adjust to circumstances connected to ill-health and retirement, 3) to pay special attention to individuals with fibromyalgia and other general pain disorders, and 4) to strengthen ADL activities to support an independent active life among disability pensioners

    Neurochemical biomarkers to study CNS effects of COVID-19: a narrative review and synthesis

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    Neurological symptoms are frequently reported in patients suffering from COVID-19. Common CNS-related symptoms include anosmia, caused by viral interaction with either neurons or supporting cells in nasal olfactory tissues. Diffuse encephalopathy is the most common sign of CNS dysfunction, which likely results from the CNS consequences of the systemic inflammatory syndrome associated with severe COVID-19. Additionally, microvascular injuries and thromboembolic events likely contribute to the neurologic impact of acute COVID-19. These observations are supported by evidence of CNS immune activation in cerebrospinal fluid (CSF) and in autopsy tissue, along with detection of microvascular injuries in both pathological and neuroimaging studies. The frequent occurrence of thromboembolic events in patients with COVID-19 has generated different hypotheses, among which viral interaction with perivascular cells is particularly attractive, yet unproven. A distinguishing feature of CSF findings in SARS-CoV-2 infection is that clinical signs characteristic of neurotropic viral infections (CSF pleocytosis and blood brain barrier injury) are mild or absent. Moreover, virus detection in CSF is rare, and often of uncertain significance. In this review, we provide an overview of the neurological impact that occur in the acute phase of COVID-19, and the role of CSF biomarkers in the clinical management and research to better treat and understand the disease. In addition to aiding as diagnostic and prognostic tools during acute infection, the use of comprehensive and well characterized CSF and blood biomarkers will be vital in understanding the potential impact on the CNS in the rapidly increasing number of individuals recovering from COVID-19

    Explicit Model Realizing Parton-Hadron Duality

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    We present a model that realizes both resonance-Regge (Veneziano) and parton-hadron (Bloom-Gilman) duality. We first review the features of the Veneziano model and we discuss how parton-hadron duality appears in the Bloom-Gilman model. Then we review limitations of the Veneziano model, namely that the zero-width resonances in the Veneziano model violate unitarity and Mandelstam analyticity. We discuss how such problems are alleviated in models that construct dual amplitudes with Mandelstam analyticity (so-called DAMA models). We then introduce a modified DAMA model, and we discuss its properties. We present a pedagogical model for dual amplitudes and we construct the nucleon structure function F2(x,Q2). We explicitly show that the resulting structure function realizes both Veneziano and Bloom-Gilman duality.Comment: 11 pages, 8 figure

    CSF Biomarkers in Patients With COVID-19 and Neurologic Symptoms: A Case Series

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    OBJECTIVE: To explore whether hospitalized patients with SARS-CoV-2 and neurologic symptoms have evidence of CNS infection, inflammation and injury using CSF biomarker measurements. METHODS: We assessed CSF SARS-CoV-2 RNA along with CSF biomarkers of intrathecal inflammation (CSF white blood cell count, neopterin, ÎČ2-microglobulin (ÎČ2M) and immunoglobulin G-index), blood-brain-barrier (BBB) integrity (albumin ratio), and axonal injury (CSF neurofilament light chain protein [NfL]) in 6 patients with moderate to severe COVID-19 and neurologic symptoms who had undergone a diagnostic lumbar puncture. Neurologic symptoms and signs included features of encephalopathies (4/6), suspected meningitis (1/6) and dysgeusia (1/6). SARS-CoV-2 infection was confirmed by rtPCR analysis of nasopharyngeal swabs. RESULTS: SARS-CoV-2 RNA was detected in the plasma of 2 patients (Cycle threshold [Ct] value 35.0-37.0) and in CSF at low levels (Ct 37.2, 38.0, 39.0) in 3 patients in one but not in a second rtPCR assay. CSF neopterin (median, 43.0 nmol/L) and ÎČ2-microglobulin (median, 3.1 mg/L) were increased in all. Median IgG-index (0.39), albumin ratio (5.35) and CSF white blood cell count (<3 cells/”L) were normal in all, while CSF NfL was elevated in 2 patients. CONCLUSION: Our results on patients with COVID-19 and neurologic symptoms suggest an unusual pattern of marked CSF inflammation in which soluble markers were increased but white cell response and other immunologic features typical of CNS viral infections were absent. While our initial hypothesis centered on CNS SARS-CoV-2 invasion, we could not convincingly detect SARS-CoV-2 as the underlying driver of CNS inflammation. These features distinguish COVID-19 CSF from other viral CNS infections, and raise fundamental questions about the CNS pathobiology of SARS-CoV-2 infection

    Neurochemical signs of astrocytic and neuronal injury in acute COVID-19 normalizes during long-term follow-up

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    Background: Neurologic manifestations are well-recognized features of coronavirus disease 2019 (COVID-19). However, the longitudinal association of biomarkers reflecting CNS impact and neurological symptoms is not known. We sought to determine whether plasma biomarkers of CNS injury were associated with neurologic sequelae after COVID-19. / Methods: Patients with confirmed acute COVID-19 were studied prospectively. Neurological symptoms were recorded during the acute phase of the disease and at six months follow-up, and blood samples were collected longitudinally. Healthy age-matched individuals were included as controls. We analysed plasma concentrations of neurofilament light-chain (NfL), glial fibrillary acidic protein (GFAp), and growth differentiation factor 15 (GDF-15). / Findings: One hundred patients with mild (n = 24), moderate (n = 28), and severe (n = 48) COVID-19 were followed for a median (IQR) of 225 (187–262) days. In the acute phase, patients with severe COVID-19 had higher concentrations of NfL than all other groups (all p < 0·001), and higher GFAp than controls (p < 0·001). GFAp was also significantly increased in moderate disease (p < 0·05) compared with controls. NfL (r = 0·53, p < 0·001) and GFAp (r = 0·39, p < 0·001) correlated with GDF-15 during the acute phase. After six months, NfL and GFAp concentrations had normalized, with no persisting group differences. Despite this, 50 patients reported persistent neurological symptoms, most commonly fatigue (n = 40), “brain-fog” (n = 29), and changes in cognition (n = 25). We found no correlation between persistent neurological symptoms and CNS injury biomarkers in the acute phase. / Interpretation: The normalization of CNS injury biomarkers in all individuals, regardless of previous disease severity or persisting neurological symptoms, indicates that post COVID-19 neurological sequelae are not accompanied by ongoing CNS injury. / Funding: The Swedish State Support for Clinical Research, SciLifeLab Sweden, and the Knut and Alice Wallenberg Foundation have provided funding for this project

    Evaluation of Chloride Diffusion and Corrosion Resistance in Reinforced Concrete Using Internal Curing and Shrinkage Reducing Admixtures

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    The properties of high-performance concretes obtained by the internal curing technique were studied in the fresh and hardened states. In some of the concrete mixtures, fine normal weight aggregates were replaced with lightweight aggregates (LWA) at 20 % vol. and ordinary portland cement was replaced by pulverized class F fly ash at 20 % by mass. Additionally, some mixtures were prepared including a shrinkage-reducing admixture, either as part of the mixing water or pre-soaked into the lightweight fine aggregates. The prepared concretes were subjected to degradation tests, such as accelerated carbonation and chloride ion deterioration. In addition, the reinforced concretes were analyzed through electrochemical corrosion tests with the linear polarization resistance technique. It was found that the internally cured concretes presented a mechanical resistance similar to those reported for the reference concretes (conventional concretes), but provided a higher resistance to carbonation, rapid penetration of chloride ions, and a lower chloride ion diffusion coefficient. The reinforcing steel structure in the internally cured concretes showed lower corrosion currents (Icorr) and corrosion potentials (Ecorr) in comparison to the reference concretes. Therefore, the use of the internal curing technique in concretes with pre-soaking in either water or a solution of shrinkage-reducing admixture can be considered as a viable alternative to extend the service life of concrete structures in contact with harmful environments

    Infection of brain pericytes underlying neuropathology of covid‐19 patients

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    A wide range of neurological manifestations have been associated with the development of COVID‐19 following SARS‐CoV‐2 infection. However, the etiology of the neurological sympto-matology is still largely unexplored. Here, we used state‐of‐the‐art multiplexed immunostaining of human brains (n = 6 COVID‐19, median age = 69.5 years; n = 7 control, median age = 68 years) and demonstrated that expression of the SARS‐CoV‐2 receptor ACE2 is restricted to a subset of neuro-vascular pericytes. Strikingly, neurological symptoms were exclusive to, and ubiquitous in, patients that exhibited moderate to high ACE2 expression in perivascular cells. Viral dsRNA was identified in the vascular wall and paralleled by perivascular inflammation, as signified by T cell and macro-phage infiltration. Furthermore, fibrinogen leakage indicated compromised integrity of the blood– brain barrier. Notably, cerebrospinal fluid from additional 16 individuals (n = 8 COVID‐19, median age = 67 years; n = 8 control, median age = 69.5 years) exhibited significantly lower levels of the pericyte marker PDGFRÎČ in SARS‐CoV‐2‐infected cases, indicative of disrupted pericyte homeostasis. We conclude that pericyte infection by SARS‐CoV‐2 underlies virus entry into the privileged central nervous system space, as well as neurological symptomatology due to perivascular inflammation and a locally compromised blood–brain barrier

    Effect of binary raw materials replacement (quartz and feldspar) for porcelain chamotte on the electro-technical siliceous porcelain properties

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    The hurry for ecological practices and waste control has emerged as an obligation in modern times, demanding precise strategies to restrain waste accumulation and to stimulate recycling and reuse actions to lower the climate effect. The replacement of binary raw materials for porcelain chamotte waste in siliceous porcelain was studied to obtain eco-friendly high-voltage porcelain. Quartz and feldspar were progressively replaced by 5, 10, and 15 wt.% of porcelain chamotte in a conventional siliceous electro-technical porcelain composition. The replacement effect on sintered samples at 1250°C under industrial heat treatment was evaluated by measuring the linear shrinkage, bulk density, porosity, flexural strength, and microhardness technological properties. Phase analysis was carried out by X-ray diffraction. Microstructural characteristics were studied using a scanning electron microscope. The results showed that chamotte-containing samples reached bulk densities of about 2.36 g/cm3 and a porosity percentage near zero. The maximum flexural strength value at glazed states was 87.8 MPa, for 15 wt.% scrap-containing samples. X-ray diffraction studies revealed a higher mullite phase content in chamotte-containing samples. Scanning electronic microscopy images of the polished and etched specimens show the presence of quartz grains and secondary mullite needles embedded in a feldspathic vitreous matrix. The properties reached by the chamotte-containing samples are attractive since the values obtained in terms of flexural strength, density, and porosity are compared to those reported for conventional siliceous porcelain were obtained. The most noticeable result was observed in flexural resistance. The glazed porcelain bodies showed a flexural strength improvement of about 15%. Then, these porcelain compositions suggest an alternative to produce a more sustainable, affordable, and environmentally-friendly porcelain insulator product
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