22 research outputs found
Near-Infrared and X-Ray Observations of XSS J12270-4859
XSS J12270-4859 (J12270) is an enigmatic source of unknown nature. Previous
studies revealed that the source has unusual X-ray temporal characteristics,
including repetitive short-term flares followed by spectral hardening,
non-periodic dips, and dichotomy in activity; i.e. intervals filled with flares
and those without. Together with a power-law X-ray spectrum, it is suggested to
be a low-mass X-ray binary (LMXB). In order to better understand the object, we
present the results of our near-infrared (NIR) photometry and linear
polarimetry observations as well as X-ray spectroscopy observations, which
overlap with each other partially in time, taken respectively with the InfraRed
Survey Facility (IRSF) and the Rossi X-ray Timing Explorer (RXTE). We detected
several simultaneous NIR and X-ray flares for the first time. No significant
NIR polarization was obtained. We assembled data taken with IRSF, RXTE, Suzaku,
Swift, and other missions in the literature and compared the flare profile and
the spectral energy distribution (SED) with some representative high-energy
sources. Based on some similarities of the repetitive NIR and X-ray flaring
characteristics and the broad SED, we argue that J12270 is reminiscent of
microquasars with a synchrotron jet, which is at a very low luminosity state of
~1e-4 Eddington luminosity for a stellar mass black hole or neutron star at a
reference distance of 1 kpc.Comment: 12 pages, 9 figures, accepted for publication in PAS
Endocytosis of commensal antigens by intestinal epithelial cells regulates mucosal T cell homeostasis
Commensal bacteria influence host physiology, without invading host tissues. We show that proteins from segmented filamentous bacteria (SFB) are transferred into intestinal epithelial cells (IECs) through adhesion-directed endocytosis that is distinct from the clathrin-dependent endocytosis of invasive pathogens. This process transfers microbial cell wall–associated proteins, including an antigen that stimulates mucosal T helper 17 (T_H17) cell differentiation, into the cytosol of IECs in a cell division control protein 42 homolog (CDC42)–dependent manner. Removal of CDC42 activity in vivo led to disruption of endocytosis induced by SFB and decreased epithelial antigen acquisition, with consequent loss of mucosal T_H17 cells. Our findings demonstrate direct communication between a resident gut microbe and the host and show that under physiological conditions, IECs acquire antigens from commensal bacteria for generation of T cell responses to the resident microbiota
Impurity emission characteristics of long pulse discharges in Large Helical Device
Line spectra from intrinsic impurity ions have been monitored during the three kinds of long-pulse discharges (ICH, ECH, NBI). Constant emission from the iron impurity shows no preferential accumulation of iron ion during the long-pulse operations. Stable Doppler ion temperature has been also measured from Fe XX, C V and C III spectra
Common coypu predation on unionid mussels and terrestrial plants in an invaded Japanese river
The coypu (Myocastor coypus) is a semi-aquatic herbivorous rodent that has been suspected to prey on freshwater unionid mussels in Japan. Fecal DNA metabarcoding that targeted bivalves and terrestrial plants was performed to examine the diet of exotic coypu in the Kiso River, central Japan. Thirty-two fecal samples from four floodplain waterbodies were collected seasonally. In one of the waterbodies, live and dead mussels were investigated to examine the possible effects of coypu predation on mussel population structures. Common coypu predation on unionid mussels was confirmed in two waterbodies. Midden surveys showed that medium- to large-sized mussels tended to be consumed by coypu; possibly resulting in population structures with few large-sized individuals. Seasonal diet selection of terrestrial plants was also detected: two perennial plants were consumed throughout the year, whereas some perennial plants were consumed seasonally. The number of terrestrial plant species/taxa as primary food was higher in summer than in winter, which was attributed to the high consumption of annual plants in the summer. Future studies need to examine the exhaustive diet of coypu including other animals and plants, as well as its effects on freshwater ecosystems in invaded regions
Comparison of dental practice income and expenses according to treatment types in the Japanese insurance system
Dental practice income and expenses according to treatment types were compared in order to obtain information for cost accounting of dental treatments and to establish successful management methods for dental treatments in order to improve the balance of dental clinics.
The results of our study are as follows:
(1) For class I restoration for molars, the balance of inlay restoration was higher than that of CR filling, while the balance per minute for CR filling was higher than that for inlay restoration. Inlay restoration would be more profitable for dental clinics with a relatively small number of patients, whereas for clinics with many patients, composite resin filling would be more profitable to increase income.
(2) There is a need for a system to increase the number of patients receiving regular dental check-ups.
(3) It is important to train dental hygienists to perform regular dental check-ups.
(4) There is a need to reconsider the present medical fee points for oral hygiene instruction and root canal treatment because their balance per minute is quite low.
(5) It is important to establish a system to increase the number of patients who choose non-insured treatment for crown restorations in order to increase the management balance of dental clinics in Japan
Endoscopic treatment of intussusception due to small intestine polyps in patients with Peutz-Jeghers Syndrome
Background and study aims Intussusception caused by intestinal polyps in patients with Peutz-Jeghers syndrome usually requires laparotomy. Patients following successful endoscopic reduction using double-balloon endoscopy (DBE) have been reported. The aim of this study was to evaluate the feasibility of endoscopic treatment of intussusception.
Patients and methods We retrospectively reviewed patients who underwent DBE for intussusception due to small intestine polyps in patients with Peutz-Jeghers syndrome from January 2004 to June 2020.
Results Twenty-seven (antegrade 22, retrograde 5) DBEs were performed in 19 patients with 25 sites of intussusception identified during the study period. If the intussusception remained once the endoscope reached the site, endoscopic reduction of the intussusception was performed as needed (15 sites). Ultimately, endoscopic resections (8 sites) or ischemic polypectomies (16 sites) of the polyp causing the intussusception were completed at 24 sites. Only one site could not be treated endoscopically and was treated surgically. The final per-site and per-patient success rates of endoscopic treatment were 96 % (24/25) and 95 % (18/19) respectively. Two patients developed mild acute pancreatitis and one patient developed intussusception after the procedures, both of which were treated non-operatively.
Conclusions Endoscopic treatment of intussusception is feasible to avoid laparotomy in patients with Peutz-Jeghers syndrome
Characterization of double-negative T cells in colorectal cancers and their corresponding lymph nodes
TCRαβ+ CD4− CD8− double-negative T (DNT) cells are minor populations in peripheral blood, and their roles have mostly been discussed in inflammation and autoimmunity. However, the functions of DNT cells in tumor microenvironment remain to be elucidated. We investigated their characteristics, possible origins and functions in colorectal cancer tissues as well as their corresponding tumor-draining lymph nodes. We found a significant enrichment of DNT cells in tumor tissues compared with their corresponding lymph nodes, especially in tumors with lower T cell infiltration. T cell receptor (TCR) sequence analysis of CD4+ T, CD8+ T and DNT cells indicated that TCR sequences detected in DNT cells were found in CD8+ T cells, but rarely in CD4+ T cells, suggesting that a part of DNT cells was likely to be originated from CD8+ T cells. Through a single-cell transcriptomic analysis of DNT cells, we found that a DNT cell cluster, which showed similar phenotypes to central memory CD8+ T cells with low expression of effector and exhaustion markers, revealed some specific gene expression patterns, including higher GZMK expression. Moreover, in flow cytometry analysis, we found that DNT cells lost production of cytotoxic mediators. These findings imply that DNT cells might function as negative regulators of anti-tumor immune responses in tumor microenvironment