37 research outputs found
Musculoskeletal Disorders and Association with Social Media Use Among University Students at the Quarantine Time Of COVID-19 Outbreak
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
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
Two photo-neutron sources, YBe and SbBe, 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
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
Search for low-mass dark matter via bremsstrahlung radiation and the Migdal effect in SuperCDMS
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
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 at
via the bremsstrahlung channel. The Migdal
channel search provides overall considerably more stringent limits and excludes
DM masses down to at .Comment: Submitted to PR
First measurement of the nuclear-recoil ionization yield in silicon at 100 eV
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
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
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