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Colorectal cancer (CRC) arises through interactions between driver mutations, such as in APC and KRAS , and the tumor microenvironment (TME), including inflammatory factors. While chronic inflammation is a known risk factor, the role of transient mild inflammation in tumorigenesis remains unclear. This study assessed the impact of mild inflammation on CRC development using genetically modified KRAS mutant (mut), APC mut, and APC; KRAS double mut mouse models. Mice received tamoxifen at six weeks and were evaluated with or without a 5-day administration of 1.5% dextran sulfate sodium (DSS). Mice were sacrificed at 20 weeks, and tumor number, size, location, histology, immunofluorescence, and RNA sequencing were analyzed. Tumors were absent in APC and KRAS mut mice not treated with DSS, while APC; KRAS mut mice developed small proximal colon tumors. DSS-treated KRAS mut mice remained tumor-free, but APC and APC; KRAS mut mice developed multiple tumors throughout the colon. In APC; KRAS mut mice, DSS significantly increased tumor number and size in the proximal colon. Although DSS did not alter immune infiltration in proximal tumors, regulatory T cells and M2 macrophages were elevated in APC; KRAS compared to APC mutants, suggesting immunosuppressive TME. These findings indicate that transient inflammation promotes CRC development in APC mutant mice.

The temperature variations of the corona and its individual surface features as a function of the solar cycle are an interesting and important aspect of understanding the physics of the Sun. To study the temperature variations, we have used the full-disk soft X-ray images of the corona obtained from Hinode/X-Ray Telescope (XRT) in different filters. A sophisticated algorithm has been developed in Python to segment the different coronal features such as the active regions (ARs), coronal holes (CHs), background regions (BGs), and X-ray bright points (XBPs), derived the total intensity of all the features, and generated the temperature maps of the corona using the filter ratio method. Due to the XRT straylight issue in some filters and unavailability of a good pair of images, we used for our analysis the filter combinations of Ti-poly and Al-mesh for the period from February 01, 2008 to May 08, 2012 and Al-poly and Al-mesh for the period from May 09, 2012 to June 30, 2021, in total for 14 years which covers Solar Cycle 24. The first analysis in using the XRT intensity values of the coronal features from segmented solar disk and their relation to solar activity is presented. We discuss the temperature variations of a full-disk corona and all features (ARs, CHs, BGs, and XBPs). Our time series plots of the average temperature of the full-disk and all the features show temperature fluctuations synchronized with the solar cycle (sunspot number). Although the temperature of all features varies, but the mean temperature estimated for the whole observed period of the full-disk is around 1.29 ± 0.16 MK and active regions (ARs) are around 1.76 ± 0.32 MK, whereas BGs, CHs, and XBPs are 1.27 ± 0.15 MK, 1.23 ± 0.14 MK, and 1.37 ± 0.18 MK, respectively. In addition, we found that the mean temperature contribution estimated of the background regions (BGs) is around 93.2%, whereas ARs, CHs, and XBPs are 3.1%, 1.6% and 2.1%, respectively, to the average coronal temperature of the full-disk. The temperature values and their variations of all the features suggest that the features show a high variability in their temperature and that the heating rate of the emission features may be highly variable on solar cycle timescales. It is evident from the analysis that the filter-ratio method can be directly used for temperature analysis of coronal features and to study their surface temperature variability as a function of solar magnetic activity.

A 53-year-old man was admitted for respiratory failure due to severe acute respiratory syndrome caused by a severe acute respiratory syndrome coronavirus 2 infection. The patient required prolonged artificial ventilation and extracorporeal membrane oxygenation (ECMO) for respiratory support. Despite successful discontinuation of ECMO, the patient experienced profuse watery diarrhea (5-10 L/day). A colonoscopy revealed an inflamed surface without undulation that uniformly extended throughout the colon. Biopsy specimens revealed complete disappearance of existing crypts and replacement with squamous or transitional epithelium normally observed in the anal transitional zone mucosa, with granulation tissue proliferation in the lamina propria. Watery diarrhea persisted despite corticosteroid and infliximab administration. Although diarrhea due to atrophy of the surface and cryptic epithelium as an intestinal manifestation of coronavirus disease 2019 usually responds to corticosteroids, refractory diarrhea can be attributed to squamous metaplasia with complete disappearance of the surface and cryptic epithelium.

Duodenal obstruction is a rare event that is unlikely to be treated endoscopically. Herein, we describe the case of a 75-year-old woman who presented with vomiting and was diagnosed with food-induced duodenal obstruction. Impacted food was fragmented and removed by double-balloon enteroscopy, and the duodenal tract was reopened without any adverse events. Follow-up capsule endoscopy was performed one month after treatment to determine the obstruction etiology and it revealed a remarkably delayed passage of the capsule through the duodenum and excessive amounts of floating food residue in the third portion of the duodenum. Obstruction recurrence was not observed six months after endoscopic treatment. In conclusion, in our case, endoscopic treatment of duodenal obstruction prevented the unnecessary performance of surgery, suggesting its clinical utility for this condition.

Solar flares are broadly classified as impulsive or gradual. Ions accelerated in a gradual flare are thought to be accelerated through a shock acceleration mechanism, but the particle acceleration process in an impulsive flare is still largely unexplored. To understand the acceleration process, it is necessary to measure the high-energy gamma rays and neutrons produced by the impulsive flare. Under such circumstances, on 7 November 2004, a huge X2.0 flare occurred on the solar surface, where ions were accelerated to energies greater than 10 GeV. The accelerated primary protons collided with the solar atmosphere and produced line gamma rays and neutrons. These particles were received as neutrons and line gamma rays, respectively. Neutrons of a few GeV, on the other hand, decay to produce secondary protons while traveling 0.06 au in the solar–terrestrial space. These secondary protons arrive at the magnetopause. Although the flux of secondary protons is very low, the effect of collecting secondary protons arriving in a wide region of the magnetosphere (the Funnel or Horn effect) has resulted in significant signals being received by the solar neutron telescope at Mt. Sierra Negra (4600 m). This information suggests that ions on the solar surface are accelerated to over 10 GeV with an impulsive flare.

It is not clear how trans-equatorial loop systems (TLSs) are formed, although they have been observed often with Yohkoh /SXT. We focus here on a TLS that appeared on 27 May 1998. Yokoyama and Masuda ( Solar Phys. 254 , 285, 2009 ) proposed a new scenario for the formation mechanism of the TLS. In this scenario, they pointed out the importance of magnetic interaction between an active region and a coronal hole to make “strong-seed magnetic fields” before a transient (bright and short-lived) trans-equatorial loop was created. The main aims of this study are to verify the scenario and to make the TLS formation mechanism clear, based on observational data. Yohkoh /SXT images, SOHO/MDI magnetograph data, and Kitt Peak coronal-hole maps were mainly used for our analyses. We investigated the TLS in detail from the time that there were no signatures of the TLS to its clear appearance. The following results are obtained: i ) an active region emerged in the vicinity of a coronal-hole boundary, ii ) the coronal-hole boundary retreated during the period when the active region was developing, iii ) temporal variations of soft X-ray intensities were roughly synchronized between the coronal-hole boundary and a trans-equatorial region, and iv ) new closed loops were observed in soft X-rays clearly at the coronal-hole boundary. Since i ), ii ), iii ), and iv ) are just what we expect in the scenario of YM2009, the scenario found support. We conclude that the TLS was originating with large-scale magnetic fields of the coronal-hole boundary through magnetic reconnection between the active region and a coronal hole.

The Soft X-ray Telescope (SXT) onboard Yohkoh often observed large-scale coronal loops connecting two active regions situated in opposite hemispheres. These are the trans-equatorial loop systems (TLSs). The formation mechanism of TLSs is not yet known. We analyzed a TLS observed simultaneously with Yohkoh /SXT and a coronagraph (SOHO/LASCO-C1). SOHO/LASCO-C1 observed loop expansion and eruption at the west solar limb. Yohkoh /SXT observed a rising motion (chromospheric evaporation) of hot and dense plasmas from the active regions located at the footpoints of the loop. Important results of our analyses are that (1) the loop eruption and the rising motion of the plasmas were simultaneous, (2) the TLS had a cusp-like appearance, and (3) the highest temperature region of the TLS was located above the bright loop seen in soft X rays. These observational results (loop expansion, eruption, and chromospheric evaporation) suggest that this bright (high-density) TLS was created by the same mechanism by which a solar flare occurs, namely, magnetic reconnection. In this paper, we propose a formation mechanism of the TLS that forms between two independent active regions.

We have established the Zao Solar Radiospectrograph (ZSR), a new solar radio observation system, at the Zao observatory of Tohoku University, Japan. We observed narrowband fine structures with type IV bursts with ZSR on 2 and 3 November 2008. The observed fine structures are similar to fiber bursts in terms of the drift rates and the existence of emission and absorption stripes. Statistical analysis of the drift rates, however, shows that the observed fine structures are different from the ordinary fiber bursts as regards the sense and the magnitude of their drift rates. First, the observed drift rates include both positive and negative rates, whereas ordinary fiber bursts are usually characterized by negative drift rates. Second, the absolute values of the observed drift rates are tens of MHz s −1 , whereas the typical drift rate of fiber bursts at 325 MHz is approximately −9 MHz s −1 . In addition, all fine structures analyzed have narrow emission bands of less than 17 MHz. We also show that the observed narrowband emission features with drift rates of approximately 40 MHz s −1 can be interpreted as the propagation of whistler-mode waves, which is the same process as that underlying fiber bursts.

The magnetic field changes the radiative output of the Sun and is the main source for all the solar surface features. To study the role of the underlying photospheric magnetic field in relation to emission features observed in the solar corona, we have used the full-disk soft X-ray images from Hinode/X-Ray Telescope ( Hinode/XRT ) and the magnetograms obtained from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) for a period of about 13 years (May 2010 – June 2023), which covers Solar Cycle 24 and the ascending phase of Solar Cycle 25. A sophisticated and established algorithm developed in Python is applied to the X-ray observations from Hinode/XRT to segment the different coronal features by creating segmentation maps of the active regions (ARs), coronal holes (CHs), background regions (BGs), and X-ray bright points (XBPs). Further, these maps have been applied to the full-disk (FD) line-of-sight (LOS) magnetograms from HMI to isolate the X-ray coronal features and photospheric magnetic counterparts, respectively. We computed full-disk and featurewise averages of X-ray intensity and LOS magnetic field (MF) over ARs, CHs, BGs, XBPs, and FD regions. Variations in the quantities resulting from the segmentation, namely the mean intensity, temperature from the filter ratio method, and the unsigned magnetic field of ARs, CHs, BGs, XBPs, and FD regions, are intercompared and compared with the sunspot number (SSN). We find that the X-ray intensity and temperature over ARs, CHs, BGs, XBPs, and FD regions are well correlated with the underlying magnetic field. We discuss the intensity, temperature, and magnetic field variations of the full-disk corona and of all the features. The time series plots of the unsigned magnetic field of the full disk and all the features show magnetic field fluctuations synchronized with the solar cycle (sunspot number). Although the magnetic field of all features varies, the mean, spatially smoothed magnitude of the magnetic field values estimated for the whole observed period of the full disk is around 8.9 ± 2.60 G, active regions (ARs) are around 34.4 ± 18.42 G, whereas BGs, CHs, and XBPs are 7.7 ± 1.72 G, 6.6 ± 1.04 G, and 15.62 ± 8.76 G, respectively. In addition, we find that the mean magnetic field contribution of the background regions (BGs) is around 85 % , whereas ARs, CHs, and XBPs are 11 % , 2 % , and 2 % , respectively, to the average magnetic field of the full disk. The magnetic field time series of all the features suggest that the features show a high variability in their magnetic field and the fluctuations in magnetic field are correlated to fluctuations in intensity and temperature, suggesting that the magnetic field is important in producing different emission features, which are associated with different intensity and temperature values. The magnetic field is responsible for the heating rate of the emission features, which are highly variable on solar cycle timescales. We conclude from the full-disk intensity-temperature-magnetogram analysis that the magnetic field plays a crucial role in driving the different brightenings, emissions, and temperature and heating of the corona at the sites of these magnetic features. In this study, we demonstrate that the segmented coronal features observed in the soft X-ray wavelength can be used as proxies to isolate the corresponding underlying magnetic structures.

We describe a catalogue of solar flares observed by the three instruments (SOT, XRT, EIS) onboard the Hinode satellite. From the launch of the Hinode satellite in September 2006 until late 2011, about 5000 solar flares (larger than A-class in the GOES classification) occurred during the five-year period of Hinode observations, and more than half of them were captured by the Hinode telescopes. Observation information for RHESSI and Nobeyama Radioheliograph are also included in the catalogue. This catalogue is distributed to users through the Internet. It will be useful and helpful for scientists in surveying flares to be analyzed, facilitate access to Hinode data, and help advance data analysis activities among the world solar community.