37 research outputs found

    Musculoskeletal Disorders and Association with Social Media Use Among University Students at the Quarantine Time Of COVID-19 Outbreak

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    Introduction: COVID-19 period was characterized by lockdown and quarantine, the aim of this cross-sectional analytical study is to investigate the effect of COVID-19 quarantine on social media use, and its association with musculoskeletal disorders (MSD) among university students. Methods: A cross sectional study was conducted among Al-Quds University students. 317 students (average age of 20.34 years) participated in this study. A self-designed questionnaire was used to collect data which was sent to students on social media using a simple random method in almost all academic year phases. Results: There was a statically significant increase in the following variables during quarantine compared to before (P0.05). There was no statistically significant difference in time spent on exercise before and during quarantine with average time before the quarantine of 0.80 hours to 0.7 hours during the quarantine (P>0.05). There was a statistically significant increase of severity of Musculoskeletal disorders (MSD) as measured by a scale of 0-10 during the quarantine (P<0.05) in terms of severity of headache (2 to 2, 78), neck pain (2.06 to 2.80), and back pain (2.17 to 3). This increase in the three dominant MSD was positively correlated with the hours of use of laptops, computers, and mobile phones, for communication and education (P<0.05). Statistically significant negative correlation was found in between night sleeping hours and severity of MSD reported by students (P<0.05). Age was correlated with less use of social media for leisure and with more exercise (P<0.05). StudentsConclusion: Quarantine increased the time of use of social media, and in turn increases the prevalence and severity of MSD among university

    Search for low-mass dark matter via bremsstrahlung radiation and the Migdal effect in SuperCDMS

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    We present a new analysis of previously published SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220 MeV/c2 at 2.7×10-30 cm2 via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30 MeV/c2 at 5.0×10-30 cm2

    Ionization yield measurement in a germanium CDMSlite detector using photo-neutron sources

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    Two photo-neutron sources, 88^{88}Y9^{9}Be and 124^{124}Sb9^{9}Be, have been used to investigate the ionization yield of nuclear recoils in the CDMSlite germanium detectors by the SuperCDMS collaboration. This work evaluates the yield for nuclear recoil energies between 1 keV and 7 keV at a temperature of \sim 50 mK. We use a Geant4 simulation to model the neutron spectrum assuming a charge yield model that is a generalization of the standard Lindhard model and consists of two energy dependent parameters. We perform a likelihood analysis using the simulated neutron spectrum, modeled background, and experimental data to obtain the best fit values of the yield model. The ionization yield between recoil energies of 1 keV and 7 keV is shown to be significantly lower than predicted by the standard Lindhard model for germanium. There is a general lack of agreement among different experiments using a variety of techniques studying the low-energy range of the nuclear recoil yield, which is most critical for interpretation of direct dark matter searches. This suggests complexity in the physical process that many direct detection experiments use to model their primary signal detection mechanism and highlights the need for further studies to clarify underlying systematic effects that have not been well understood up to this point

    Investigating the sources of low-energy events in a SuperCDMS-HVeV detector

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    Search for low-mass dark matter via bremsstrahlung radiation and the Migdal effect in SuperCDMS

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    We present a new analysis of previously published SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220  MeV/c2 at 2.7×10−30  cm2 via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30  MeV/c2 at 5.0×10−30  cm2

    A Search for Low-mass Dark Matter via Bremsstrahlung Radiation and the Migdal Effect in SuperCDMS

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    We present a new analysis of previously published of SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220 MeV/c2220~\textrm{MeV}/c^2 at 2.7×1030 cm22.7 \times 10^{-30}~\textrm{cm}^2 via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30 MeV/c230~\textrm{MeV}/c^2 at 5.0×1030 cm25.0 \times 10^{-30}~\textrm{cm}^2.Comment: Submitted to PR

    First measurement of the nuclear-recoil ionization yield in silicon at 100 eV

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    We measured the nuclear--recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a mono-energetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4\,keV down to 100\,eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100\,eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale

    Effect of hydrophobic extension of aryl enaminones and pyrazole-linked compounds combined with sulphonamide, sulfaguanidine, or carboxylic acid functionalities on carbonic anhydrase inhibitory potency and selectivity

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    AbstractDesign and synthesis of three novel series of aryl enaminones (3a–f and 5a–c) and pyrazole (4a-c) linked compounds with sulphonamides, sulfaguanidine, or carboxylic acid functionalities were reported as carbonic anhydrase inhibitors (CAIs) using the “tail approach” strategy in their design to achieve the most variable amino acids in the middle/outer rims of the hCAs active site. The synthesised compounds were assessed in vitro for their inhibitory activity against the following human (h) isoforms, hCA I, II, IX, and XII using stopped-flow CO2 hydrase assay. Enaminone sulphonamide derivatives (3a–c) potently inhibited the target tumour-associated isoforms hCA IX and hCA XII (KIs 26.2–63.7 nM) and hence compounds 3a and 3c were further screened for their in vitro cytotoxic activity against MCF-7 and MDA-MB-231 cancer cell lines under normoxic and hypoxic conditions. Derivative 3c showed comparable potency against both MCF-7 and MDA-MB-231 cancer cell lines under both normoxic ((IC50 = 4.918 and 12.27 µM, respectively) and hypoxic (IC50 = 1.689 and 5.898 µM, respectively) conditions compared to the reference drug doxorubicin under normoxic (IC50 = 3.386 and 4.269 µM, respectively) and hypoxic conditions (IC50 = 1.368 and 2.62 µM, respectively). Cell cycle analysis and Annexin V-FITC and propidium iodide double staining methods were performed to reinforce the assumption that 3c may act as a cytotoxic agent through the induction of apoptosis in MCF-7 cancer cells

    Effect of hydrophobic extension of aryl enaminones and pyrazole-linked compounds combined with sulphonamide, sulfaguanidine, or carboxylic acid functionalities on carbonic anhydrase inhibitory potency and selectivity

    No full text
    Design and synthesis of three novel series of aryl enaminones (3a–f and 5a–c) and pyrazole (4a-c) linked compounds with sulphonamides, sulfaguanidine, or carboxylic acid functionalities were reported as carbonic anhydrase inhibitors (CAIs) using the “tail approach” strategy in their design to achieve the most variable amino acids in the middle/outer rims of the hCAs active site. The synthesised compounds were assessed in vitro for their inhibitory activity against the following human (h) isoforms, hCA I, II, IX, and XII using stopped-flow CO2 hydrase assay. Enaminone sulphonamide derivatives (3a–c) potently inhibited the target tumour-associated isoforms hCA IX and hCA XII (KIs 26.2–63.7 nM) and hence compounds 3a and 3c were further screened for their in vitro cytotoxic activity against MCF-7 and MDA-MB-231 cancer cell lines under normoxic and hypoxic conditions. Derivative 3c showed comparable potency against both MCF-7 and MDA-MB-231 cancer cell lines under both normoxic ((IC50 = 4.918 and 12.27 µM, respectively) and hypoxic (IC50 = 1.689 and 5.898 µM, respectively) conditions compared to the reference drug doxorubicin under normoxic (IC50 = 3.386 and 4.269 µM, respectively) and hypoxic conditions (IC50 = 1.368 and 2.62 µM, respectively). Cell cycle analysis and Annexin V-FITC and propidium iodide double staining methods were performed to reinforce the assumption that 3c may act as a cytotoxic agent through the induction of apoptosis in MCF-7 cancer cells. </p
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