We present X-ray timing results of the new black hole candidate MAXI J1535−571 during its 2017 outburst from Hard X-ray Modulation Telescope (Insight-HXMT) observations taken from 2017 September 6 to ...23. Following the definitions given by Belloni, we find that the source exhibits transitions from the low/hard state to the hard intermediate state, and eventually to the soft intermediate state. Quasi-periodic oscillations (QPOs) are found in the intermediate states, which suggest different types of QPOs. With the large effective area of Insight-HXMT at high energies, we are able to present the energy dependence of the QPO amplitude and centroid frequency up to 100 keV, which has rarely been explored by previous satellites. We also find that the phase lag at the type-C QPOs centroid frequency is negative (soft lag) and strongly correlated with the centroid frequency. Assuming a geometrical origin of type-C QPOs, the source is consistent with being a high-inclination system.
The global ionospheric maps (GIMs) produced by JPL are used to investigate the longitudinal structure of the low latitude ionosphere. As a proxy of the ionization parameter at low latitudes, the ...latitudinally integrated total electron content (ITEC) is first extracted from low latitude GIMs and then Fourier filtered to obtain the wavenumber‐4 components. We then study in detail the diurnal, seasonal and solar cycle variations of the wave patterns. It is found that the wavenumber‐4 patterns are intense and well developed in boreal summer and early boreal autumn, but quite weak in boreal winter. This seasonal variation is consistent with that of the zonal wind of the non‐migrating tide mode DE3. We also found that the wavenumber‐4 patterns shift eastward with a shifting speed that is smaller in daytime than at night. This is attributed to the contribution of both the eastward propagation of DE3 in E‐region and the zonal E ×B ion drifts in F‐region. Our results support the suggestion that the longitudinal wavenumber‐4 structure of the low latitude ionosphere should be originated from the non‐migrating tide mode DE3.
Atherosclerosis (AS) is the leading cause of death for humans worldwide, and some circular RNAs (circRNAs) have been demonstrated to play important roles in its progression. In this study, we mainly ...investigated the functions and molecular mechanisms of circRNA-PTPRA (circPTPRA) in AS.
The expressions of circPTPRA and miR-636 were detected in serum samples of AS patients (n=30) and healthy controls (n=30) by RT-PCR. Then levels of circPTPRA were detected after ox-LDL treatment into vascular smooth muscle cell (VSMCs), macrophage and endothelial cells. LV-sh circPTPRAs were constructed and infected into VSMCs. CCK-8 assay was performed to measure cell proliferation abilities, flow cytometry (FACS) was performed to measure cell-cycle distribution and TUNEL staining was performed to detect cell apoptosis. Western blot (WB) was performed to detect protein levels of SP1, Cyclin D1, Cyclin E, Bax, Bad, Cleaved Caspase3. Luciferase reporter assay was performed to verify the potential binding sites of circPTPRA and miR-636, miR-636 and SP1.
RT-PCR showed that circPTPRA was upregulated in serum samples of AS patients, which was increased by ox-LDL in VSMCs. CircPTPRA inhibition repressed cell proliferation, improved cell-cycle distribution in G0/G1 phase and promoted cell apoptosis. MiR-636, a potential target for circPTPRA, was reduced in serum samples of AS patients and Luciferase reporter assay confirmed that circPTPRA could directly sponge with miR-636 in VSMCs. Furthermore, miR-636 inhibition promoted proliferation and repressed apoptosis of VSMCs, while miR-636 overexpression reversed these results. SP1, a transcription factor that played some roles in the progression of AS, was predicted to be a target of miR-636. MiR-636 inhibition increased SP1 while miR-636 overexpression repressed SP1 expression, Luciferase reporter assay proved that miR-636 could target at SP1 in VSMCs. Moreover, the repressed cell proliferation and promoted cell apoptosis abilities in LV-sh SP1 were reversed following with miR-636 inhibitor transfection. In addition, the repressed cell proliferation and promoted cell apoptosis abilities in VSMCs with LV-sh circPTPRAs were reversed following with miR-636 inhibitor transfection, which suggested that circPTPRA regulated cell proliferation and apoptosis through miR-636/SP1 axis in AS.
According to the results, we found that circPTPRA was upregulated in serum samples of AS patients, which promoted cell proliferation and inhibited cell apoptosis through repressing miR-636 and upregulating SP1 signaling axis. Our results uncovered a potential role of circPTPRA, which might be a marker and therapeutic target for AS patients.
This study aims to quantitatively summarize the association between night shift work and the risk of metabolic syndrome (MetS), with special reference to the dose–response relationship with years of ...night shift work. We systematically searched all observational studies published in English on PubMed and Embase from 1971 to 2013. We extracted effect measures (relative risk, RR; or odd ratio, OR) with 95% confidence interval (CI) from individual studies to generate pooled results using meta‐analysis approach. Pooled RR was calculated using random‐ or fixed‐effect model. Downs and Black scale was applied to assess the methodological quality of included studies. A total of 13 studies were included. The pooled RR for the association between ‘ever exposed to night shift work’ and MetS risk was 1.57 (95% CI = 1.24–1.98, pₕₑₜₑᵣₒgₑₙₑᵢₜy = 0.001), while a higher risk was indicated in workers with longer exposure to night shifts (RR = 1.77, 95% CI = 1.32–2.36, pₕₑₜₑᵣₒgₑₙₑᵢₜy = 0.936). Further stratification analysis demonstrated a higher pooled effect of 1.84 (95% CI = 1.45–2.34) for studies using the NCEP‐ATPIII criteria, among female workers (RR = 1.61, 95% CI = 1.10–2.34) and the countries other than Asia (RR = 1.65, 95% CI = 1.39–1.95). Sensitivity analysis confirmed the robustness of the results. No evidence of publication bias was detected. The present meta‐analysis suggested that night shift work is significantly associated with the risk of MetS, and a positive dose–response relationship with duration of exposure was indicated.
A second-order phase transition in a physical system is associated with the emergence of an "order parameter" and a spontaneous symmetry breaking. The heavy fermion superconductor URu2Si2 has a ..."hidden order" (HO) phase below the temperature of 17.5 kelvin; the symmetry of the associated order parameter has remained ambiguous. Here we use polarization-resolved Raman spectroscopy to specify the symmetry of the low-energy excitations above and below the HO transition. We determine that the HO parameter breaks local vertical and diagonal reflection symmetries at the uranium sites, resulting in crystal field states with distinct chiral properties, which order to a commensurate chirality density wave ground state.
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