Nucleon-Nucleon Scattering in a Strong External Magnetic Field and the Neutrino Emissivity

The nucleon-nucleon scattering in a large magnetic background is considered to find its potential to change the neutrino emissivity of the neutron stars. For this purpose we consider the one-pion-exchange approximation to find the NN cross-section in a background field as large as $10^{15}\texttt{G}-10^{18}\texttt{G}$. We show that the NN cross-section in neutron stars with temperatures in the range 0.1-5 \texttt{MeV} can be changed up to the one order of magnitude with respect to the one in the absence of the magnetic field. In the limit of the soft neutrino emission the neutrino emissivity can be written in terms of the NN scattering amplitude therefore the large magnetic fields can dramatically change the neutrino emissivity of the neutron stars as well.Comment: 21 pages, 5 figures, to appear in PR

Neutrino-electron scattering in noncommutative space

Neutral particles can couple with the $U(1)$ gauge field in the adjoint representation at the tree level if the space-time coordinates are noncommutative (NC). Considering neutrino-photon coupling in the NC QED framework, we obtain the differential cross section of neutrino-electron scattering. Similar to the magnetic moment effect, one of the NC terms is proportional to $\frac 1 T$, where $T$ is the electron recoil energy. Therefore, this scattering provides a chance to achieve a stringent bound on the NC scale in low energy by improving the sensitivity to the smaller electron recoil energy.Comment: 12 pages, 2 figure

Risk of stroke in hospitalized SARS-CoV-2 infected patients: A multinational study

Background: There is an increased attention to stroke following SARS-CoV-2. The goal of this study was to better depict the short-term risk of stroke and its associated factors among SARS-CoV-2 hospitalized patients. Methods: This multicentre, multinational observational study includes hospitalized SARS-CoV-2 patients from North and South America (United States, Canada, and Brazil), Europe (Greece, Italy, Finland, and Turkey), Asia (Lebanon, Iran, and India), and Oceania (New Zealand). The outcome was the risk of subsequent stroke. Centres were included by non-probability sampling. The counts and clinical characteristics including laboratory findings and imaging of the patients with and without a subsequent stroke were recorded according to a predefined protocol. Quality, risk of bias, and heterogeneity assessments were conducted according to ROBINS-E and Cochrane Q-test. The risk of subsequent stroke was estimated through meta-analyses with random effect models. Bivariate logistic regression was used to determine the parameters with predictive outcome value. The study was reported according to the STROBE, MOOSE, and EQUATOR guidelines. Findings: We received data from 26,175 hospitalized SARS-CoV-2 patients from 99 tertiary centres in 65 regions of 11 countries until May 1st, 2020. A total of 17,799 patients were included in meta-analyses. Among them, 156(0.9) patients had a stroke�123(79) ischaemic stroke, 27(17) intracerebral/subarachnoid hemorrhage, and 6(4) cerebral sinus thrombosis. Subsequent stroke risks calculated with meta-analyses, under low to moderate heterogeneity, were 0.5 among all centres in all countries, and 0.7 among countries with higher health expenditures. The need for mechanical ventilation (OR: 1.9, 95 CI:1.1�3.5, p = 0.03) and the presence of ischaemic heart disease (OR: 2.5, 95 CI:1.4�4.7, p = 0.006) were predictive of stroke. Interpretation: The results of this multi-national study on hospitalized patients with SARS-CoV-2 infection indicated an overall stroke risk of 0.5(pooled risk: 0.9). The need for mechanical ventilation and the history of ischaemic heart disease are the independent predictors of stroke among SARS-CoV-2 patients. Funding: None. © 2020 The Author

Preparation of ion-imprinted polyvinyl sulfonate-grafted silica particles for trace enrichment of Th(IV) prior to determination by inductively coupled plasma-mass spectrometry

Grafting from polymerisation technique has been used to prepare Th(IV) ion-imprinted polyvinyl sulfonate (IIPVS)-bonded silica particles. The graft polymerisation of vinyl sulfonate (VS) on the surface of silica particles was achieved in aqueous medium through thermal decomposition of surface-bound azo initiators (60°C) in the presence of thorium ion. The prepared material was characterised by Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The entrapped template ion was then removed using 2 M HCl. The experimental batch rebinding data were successfully described by the Langmuir�Freundlich model. The prepared material was then packed to a PTFE micro-column (20mm�3.0mm, id) to evaluate its efficiency in column operations prior to determination by inductively coupled plasma-mass spectrometry (ICP-MS). The limit of detection of the method and breakthrough capacity of the column was evaluated as 0.074µgL�1 and 0.83mgg�1, respectively. The selectivity of the prepared polymer towards Th(IV) ion was investigated in the presence of some foreign competitor ions, including U(VI). Finally, the proposed method has been used to determine Th(IV) ion in real samples. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Prooxidant-antioxidant balance and hs-CRP in patients with Beta-thalassemia major

Background: Beta-thalassemia major is one of the most frequent hemoglobinopathies in the world. This is a study on the levels of prooxidant-antioxidant balance (PAB) that can measure the pro-oxidant burden and the anti-oxidant capacity simultaneously in one assay, giving a redox index, as well as an assessment of high-sensitivity C-reactive protein (hs-CRP) in patients with β-thalassemia major. It also determines the impact both on kidney function tests. Methods: Ninety subjects with β-thalassemia major (βTM) and 90 more healthy subjects as the control group were enrolled in the study. Laboratory parameters, serum hs-CRP, and the novel assay of prooxidant-antioxidant balance were measured. Results: Biochemical and hematological variables, except MCHC, were significantly decreased in patients. Ferritin (p 0.05) did not significantly increase in patients. Spearman's correlation univariate analysis showed no significant correlation between PAB with hs-CRP or ferritin. However, there was a significant statistical correlation between hs-CRP with creatinine and triglycerides. Also we found a slight and negative correlation between high-density lipoprotein cholesterol, hemoglobin, and hemotocrit with inflammatory factor. Conclusions: Briefly, we found higher levels of PAB values and a slight increase in hs-CRP concentration in patients, which may be involved in the pathological consequences of β-thalassemia major and contribute to the gradual development of injury to the organs

Effect of a magnetic field on Schwinger mechanism in de Sitter spacetime

We investigate the effect of a constant magnetic field background on the scalar QED pair production in a four-dimensional de Sitter spacetime (\dsf). We have obtained the pair production rate which agrees with the known Schwinger result in the limit of Minkowski spacetime and with the Hawking radiation in de Sitter spacetime (dS) in the zero electric field limit. Our results describe how the cosmic magnetic field affects the pair production rate in cosmological setups. In addition, using the zeta function regularization scheme we have calculated the induced current and examined the effect of a magnetic field on the vacuum expectation value of the current operator. We find that, in the case of a strong electromagnetic background the current responds as $E\cdot B$, while in the infrared regime, it responds as $B/E$, which leads to a phenomenon of infrared hyperconductivity. These results of the induced current have important applications for the cosmic magnetic field evolution.Comment: v2: 24 pages, 3 figures, typos corrected, appendixes and references adde