9 research outputs found

    A Heavy QCD Axion model in Light of Pulsar Timing Arrays

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    Recently, pulsar timing array (PTA) experiments reported the observation of a stochastic gravitational wave (GW) background in the nanohertz range frequency band. We show that such signal can be originated from a cosmological first-order phase transition (PT) within a well-motivated heavy (visible) QCD axion model. Considering the Peccei-Quinn symmetry breaking at the TeV scale in the scenario, we find a supercooled PT, in the parameter space of the model, prolonging the PT with the reheating temperature at the GeV scale.Comment: 7 pages, 4 figure

    Magnesium Sulfate Effect on the Clinical Course and GCS of Patients with a Severe Diffuse Axonal Injury

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    Based on a number of studies, magnesium sulfate (MgSO4) given after a diffuse axonal injury has gained attention as a useful neuroprotective agent .The present study was conducted to examine if magnesium sulfate has a therapeutic efficacy and safety in patients with a severe diffuse axonal injury. Adult patients admitted within 1 hour of a closed Traumatic Brain Injury (TBI) with a severe diffuse axonal injury that met eligibility criteria were randomized into two groups. Our treatment guidelines consisted of an initial loading dose of 50 mg/kg magnesium sulfate and then 50 mg/kg QID up to 24 hours after the trauma. The outcome measures were mortality, GCS, and motor function scores which were assessed up to 2 months after the trauma. Magnesium showed a significant positive effect on GCS 2 months (P=0.03).  Among those in MgSO4 group, motor functioning score improved more than control group but this was not statistically significant (P = 0.51). At the end, we have demonstrated that administration of magnesium sulfate can have neuroprotective role following severe DAI.

    Lepton

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    With regard to the leptonic magnetic dipole moment anomaly as well as the W-boson mass excess, we study the DFSZ axion model. Considering theoretical and experimental constraints, we show that the muon and electron g2g-2 anomalies can be explained within the parameter space of the model for extra Higgs bosons with mass spectra around the electroweak scale and for an almost equivalent contribution of one-and two-loop diagrams. A negative electron g2g-2 could be achieved by introducing heavy neutrinos. Furthermore, the W-boson mass excess can be consistently addressed within the mass range of the matter content testable at collider experiments

    Energy loss at zero temperature from extremal black holes

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    Abstract Using the AdS/CFT correspondence, we probe the extremal black holes by studying the energy loss of a moving heavy point particle in a strongly-coupled boundary field theory at zero temperature and finite charge density. We first consider the extremal AdS-Reissner-Nordström (AdSRN) background black hole in the bulk and find an analytic solution of drag force which depends on the finite charge density of the boundary field theory. By studying the near horizon geometry of trailing string in the bulk, one finds the IR divergency does not show the logarithmic behavior. This result would be a general property of extremal backgrounds. We also extend our study to the extremal backgrounds with vanishing entropy density in appropriate extremal limits. After studying the Langevin coefficients, it is shown that in the extremal black hole backgrounds the longitudinal Langevin diffusion coefficient along the semiclassical string motion is larger compared to that of the transverse direction

    Evaluation of the Effects of Resting in Appearance of Post Lumbar Puncture Headache

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    Lumbar puncture (LP) is a procedure for obtaining spinal fluid from spinal meningeal spaces this can be done as a diagnostic or therapeutic procedure which can result in to a typical positional headache named as post lumbar puncture headache .This can cause a lot of discomforts for patients and makes fear from the procedure. This study designed to evaluate the effect of resting position after LP on post lumbar puncture headache (PLPH). Patients who had a diagnostic lumbar puncture were divided randomly in two groups .Group A patients had one hour rest in the supine position while group B patients had one hour rest in the prone position. Both groups followed for appearance of symptoms of PLPH for 5 days. 119 patients completed the study, 57 (48%) male patients and 62 (52%) female .PLPH totally appeared in 38 (31.9%) patients .In the group A PLPH was present in 20 patients whereas in group B it was present in 18 patients. Statistical analysis showed no significant differences between two groups (P>0.07). Position of rest after LP has no significant effect on reducing post lumbar puncture headache and there is no need to emphasize on position of rest after LP

    SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

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    Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population
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