27 research outputs found

    On Hardy-Hilbert-type inequalities with α-fractional derivatives

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    In the current manuscript, new alpha delta dynamic Hardy-Hilbert inequalities on time scales are discussed. These inequalities combine and expand a number of continuous inequalities and their corresponding discrete analogues in the literature. We shall illustrate our results using Hölder's inequality on time scales and a few algebraic inequalities

    Qatar Biobank: COVID-19 biorepository project

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    Background: The rapid spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its resulting disease (COVID-19) is one of the greatest global public health crisis of the recent decades 1 . The COVID-19 Biorepository is a national project aimed to support the high demand of biomedical research by multiple groups and the need to have access to high quality, curated clinical data, and specimens contributing to the understanding of, and response to, the COVID-19 pandemic and its impacts in Qatar 2, 3 . Methods/Case presentation: Patients with a laboratory diagnosis of COVID-19, who were Qatar residents that could communicate in Arabic, English, Hindi, and Urdu were eligible to participate in the study. COVID-19 diagnosed patients were recruited at the time of their disease period from the main three public hospitals (Communicable Disease Center, Cuban, and Hazm Mebaireek Hospitals) serving as isolation facilities of symptomatic patients in Qatar, during a 7-month period from March 2020 until September 2020. Consented participants were followed up on a weekly basis until recovery, and then monthly for a year. Sociodemographic and clinical data were collected in electronic questionnaires via a face-to-face interview by trained Qatar Biobank (QBB) staff. Results: A total of 2097 consented participants were recruited up to September 2020, males (N = 1050) and females (N = 1047), with a mean age of 41 years (SD: 15.5). 61.0% of the participants had at least one follow up while 27% adhered to monthly follow up visits. Data was collected for 99.7% of the participants, while the follow up process is still ongoing. In total there are 107,171 high quality specimens in the biorepository including plasma, erythrocytes, buffy coat, serum, PAXgene whole blood, nasopharyngeal secretions, and DNA. Conclusion: The COVID-19 Biorepository is a national asset to illuminate the pathophysiological and identify markers of disease prognosis as well as to describe the clinical features and epidemiology of COVID-19 in Qatar and worldwide.qscienc

    Magnetic resonance imaging versus transcranial ultrasound in early identification of cerebral injuries in neonatal encephalopathy

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    AbstractObjectiveNeonatal encephalopathy (NE) is a condition that causes significant morbidity and mortality to the infant. The diagnosis and severity of NE rely heavily on clinical presentation and imaging findings.The present study was planned to assess the role of MRI and Transcranial ultrasound (TCUS) in the early identification of cerebral injuries in NE.Patients and methodsOur study enrolled 38 newborns presented with NE. Brain MRI and TCUS were carried out for each case and their results were compared.ResultsMRI was positive in 33 cases. Findings at MRI supported hypoxic-ischemic encephalopathy as an etiology in 25 neonates, and other etiologies included metabolic disorders in 2, congenital neonatal infection in 1, 2 cases of neonatal stroke, congenital brain anomalies in 2 neonates and cerebral venous sinus thrombosis in 1. The overall diagnostic accuracy of TCUS compared to MRI was 78.9%, while the overall sensitivity and specificity were 81.8% and 60% respectively.ConclusionTCUS is an effective screening tool in detecting the etiology of NE in suspected cases; it is sometimes crucial in critically sick neonates; however, early MRI is mandatory as it can detect precisely the extent of brain injury compared with TCUS alone

    An Innovative Polymer-Based Electrochemical Sensor Encrusted with Tb Nanoparticles for the Detection of Favipiravir: A Potential Antiviral Drug for the Treatment of COVID-19

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    An innovative polymer-based electro-sensor decorated with Tb nanoparticles has been developed for the first time. The fabricated sensor was utilized for trace determination of favipiravir (FAV), a recently US FDA-approved antiviral drug for the treatment of COVID-19. Different techniques, including ultraviolet-visible spectrophotometry (UV-VIS), cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray Diffraction (XRD) and electrochemical impedance spectroscopy (EIS), were applied for the characterization of the developed electrode TbNPs@ poly m-THB/PGE. Various experimental variables, including pH, potential range, polymer concentration, number of cycles, scan rate and deposition time, were optimized. Moreover, different voltammetric parameters were examined and optimized. The presented SWV method showed linearity over the range of 10-150 × 10-9 M with a good correlation coefficient (R = 0.9994), and the detection limit (LOD) reached 3.1 × 10-9 M. The proposed method was applied for the quantification of FAV in tablet dosage forms and in human plasma without any interference from complex matrices, obtaining good % recovery results (98.58-101.93%)

    General Anesthetic Use in Fragile X Spectrum Disorders.

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    The fragile X premutation is characterized by a repeat expansion mutation (between 55 to 200 CGG repeats) in the fragile X mental retardation 1 (FMR1) gene, which leads to RNA toxicity at the cellular level. This may cause patients with the premutation to be particularly susceptible to environmental toxins, which could manifest clinically as new or worsening ataxia and memory loss. Multiple published case reports have also suggested general anesthetics as a potential toxin leading to negative side effects when used in patients with fragile X-associated disorders. However, at this time, there have been no formal research studies regarding cellular changes or long-term clinical manifestations after general anesthetic use in this population. This review aims to highlight previous case reports regarding sequelae related to general anesthetic use in fragile X-associated disorders. New case reports related to this phenomenon are also included

    <i>In vitro</i> evaluation of cytotoxic activity of the ethanol extract and isolated compounds from the corms of <i>Liatris spicata</i> (L.) willd on HepG2

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    <p>Investigation of the ethanol extract of the corms of <i>Liatris spicata</i> (L.) willd led to the isolation of two sterols: stigmasterol and its 3-<i>O</i>-glucoside, a triterpene: obtusifoliyl acetate, two benzofurans: euparin and 6-hydroxy-3-methoxytremetone, three phenolic acids: protocatechuic, vanillic and ferulic acid and a sesquiterpene lactone igalan. The structures of the isolated compounds were established on the basis of physicochemical properties and spectral analysis (IR, EI/MS, <sup>1</sup>H NMR and <sup>13</sup>C NMR). The ethanol extract and its isolated compounds evidenced cytotoxic activities against human liver cancer cell line (HepG2), where igalan showed the highest potency (3.83 ± 0.043) μg/mL, its effect was comparable to that of the standard drug doxorubicin® (3.73 ± 0.036) μg/mL.</p

    Mechanical Properties Study of Borosilicate Glass Loaded with Vanadium and Cobalt by Nanoindentation Technique

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    The nanoindentation test was used to investigate the mechanical properties of borosilicate glass with a composition (mol%) of 40 Na2B4O7-40 SiO2-(20-x) V2O5-x Co2O3, with x = 0, 1, 3, and 5 mol% for samples A, B, C, and D, respectively. Samples were prepared using the melt quenching technique at 1100 °C. A load–displacement curve was plotted and used to extract select mechanical properties of the glass samples. The creep deformation behavior of the glass composition was studied. The maximum creep rate was observed for the sample that contained the highest vanadium oxide content, and the creep rate decreased with a decrease in the vanadium oxide content in the glass samples. The hardness and reduced modulus of elasticity were obtained. The Maxwell–Voigt model was applied to investigate the relaxation kinetics and deformation of the bulk glass
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