Obliquity of an Earth-like planet from frequency modulation of its direct imaged lightcurve: mock analysis from general circulation model simulation

Direct-imaging techniques of exoplanets have made significant progress recently, and will eventually enable to monitor photometric and spectroscopic signals of earth-like habitable planets in the future. The presence of clouds, however, would remain as one of the most uncertain components in deciphering such direct-imaged signals of planets. We attempt to examine how the planetary obliquity produce different cloud patterns by performing a series of GCM (General Circulation Model) simulation runs using a set of parameters relevant for our Earth. Then we use the simulated photometric lightcurves to compute their frequency modulation due to the planetary spin-orbit coupling over an entire orbital period, and attempt to see to what extent one can estimate the obliquity of an Earth-twin. We find that it is possible to estimate the obliquity of an Earth-twin within the uncertainty of several degrees with a dedicated 4 m space telescope at 10 pc away from the system if the stellar flux is completely blocked. While our conclusion is based on several idealized assumptions, a frequency modulation of a directly-imaged earth-like planet offers a unique methodology to determine its obliquity.Comment: 29 pages, 18 figures, accepted for publication in Ap

Preventive effect of ecabet sodium on low-dose aspirin-induced small intestinal mucosal injury: a randomized, double-blind, pilot study

Abstract Background We aimed to investigate how high-dose ecabet sodium affects low-dose aspirin-induced small intestinal mucosal injury in healthy volunteers. Methods Healthy volunteers were enrolled randomly into one of two groups with the following drug regimens for 2 weeks: group A, low-dose aspirin once per day and group B, low-dose aspirin and 4.0 g of ecabet sodium. Small bowel capsule endoscopy was performed before and 2 weeks after low-dose aspirin administration. Results A significant difference was found in the median number [range] of small intestinal lesions between baseline and two weeks after low-dose aspirin administration in group A (baseline: 1 [0–5], after: 5 [1–11]; p = 0.0059) but not in group B (baseline: 0.5 [0–9], after: 3 [0–23]; p = 0.0586). In group B, although the median number [range] of lesions in the first tertile of the small intestine did not increase two weeks after low-dose aspirin administration (baseline: 0 [0–4], after: 1.5 [0–8]; p = 0.2969), the number of lesions in the second and third tertiles of the small intestine increased significantly (baseline: 0 [0–5], after: 2 [0–15]; p = 0.0469). Conclusions Ecabet sodium had a preventive effect on low-dose aspirin-induced small intestinal mucosal injury in the upper part of the small intestine. Trial registration ISRCTN 99322160, 01/10/2018

Enhancement of diffraction efficiency of laminar-type diffraction gratings overcoated with diamond-like carbon (DLC) in soft x-ray region

Born is the critical trace element due to take the advantage of improving quenching characteristics in steel. Recently there is a great demand to detect the B-K emission band at around 6.76 nm more efficiently. To meet this demand we performed a feasibility study to enhance the diffraction efficiency of laminar-type diffraction grating based on a newly discovered physical phenomenon in the region of total reflection. The phenomenon is embodied as a transparent high-density material layer overcoated on a metal layer on grating grooves. The material should have intermediate diffractive index of vacuum and the metal layer. We found that high density diamond-like carbon (DLC) having a density of 3.1 g/cm3 is one of the best material and simulated the diffraction efficiency in a spectral region of 3.5-8.5 nm. The optimum thickness is 24 nm for an incidence angle of 87.0. Then the first order diffraction efficiency is expected to achieve up to 29.7 %, which is improved from 15.6 % for Ni or 14.1 % for Au, at 6.76 n

Blue mode imaging may improve the detection and visualization of small-bowel lesions: A capsule endoscopy study

Background/Aims: Diagnostic miss rate and time consumption are the two challenging limitations of small-bowel capsule endoscopy (SBCE). In this study, we aimed to know whether using of the blue mode (BM) combined with QuickView (QV) at a high reviewing speed could influence SBCE interpretation and accuracy. Materials and Methods: Seventy CE procedures were totally reviewed in four different ways; (1) using the conventional white light, (2) using the BM, [on a viewing speed at 10 frames per second (fps)], (3) using white light, and (4) using the BM (on a viewing speed at 20 fps). In study A, the results of (1) were compared with those of (2), and in study B, the results of (3) and (4) were separately compared with those of (1). Results: In study A, the total number of the vascular (P < 0.001) and the inflammatory lesions (P = 0.005) detected by BM was significantly higher than that detected by the white light. No lesion was found using the white light that was not detected by the BM. Moreover, the BM highly improved the image quality of all the vascular lesions and the erythematous ones from the nonvascular lesions. In study B, the total number of only the vascular lesions, detected by the BM on a rapid speed of viewing at 20 fps was significantly higher than that detected by the white light (P = 0.035). However, the true miss rate for the BM was 4%. Conclusion: BM imaging is a new method that improved the detection and visualization of the vascular and erythematous nonvascular lesions of SB as compared with the conventional white light imaging. Using of the BM at a slow viewing speed, markedly reduced the diagnostic miss rate of CE