Na-ion dynamics in Quasi-1D compound NaV2O4

We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV2O4. By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above Tdiff=250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above Tdiff . Such results makes this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV2O4 and related compounds in energy related applications.Comment: Accepted for publication in Journal of Physics: Conference Series (2014

THE FIRST-YEAR EXPERIENCE INCORPORATING THE ORGANIZATIONAL DEVELOPMENT APPROACH AT KOBE TOKIWA UNIVERSITY

In Japan, the first-year experience that rapidly gained attention at the beginning of the twenty-first century was clearly positioned in 2008 as formal undergraduate educational programs (The Central Council for Education, 2008). The term “first-year experience” is defined as a “comprehensive educational program primarily created for freshmen” to promote their smooth transition from high school to university and to create successful academic and social experiences at university (The Central Council for Education, 2008). Thus, the first-year experience is a specific program with activities implemented by diverse universities to fit the unique needs of their first-year university students (Tachi, 2008). One important issue of the first-year experience within the undergraduate program has been identifying ways to guarantee the quality of education. Kobe Tokiwa University’s four departments (medical technology, nursing, child education, and dental hygiene) require students to gain strong abilities to collaborate and cooperate in teams to be responsible for future team medical care or a school as a team. Therefore, in 2018, the university implemented a first-year experience program that incorporated the organizational development approach instead of the conventional human resource development approach. This article shares our experiences using a first-year experience program that incorporates the organizational development approach, and we discuss the potential of this approach for the first-year experience. To estimate the effectiveness of organizational development approach in FYE, we analyzed and compared the interim data that were reported on students in 2017 and 2018 using a text mining method. By introducing this “Organizational Development” approach into the students’ first-year educational curriculum, results suggest that it is possible to “deepen self-understanding” and “cooperate in self-understanding of others” at an early stage of a student’s enrollment. It is thought that this approach could become another effective method for universities to use for training professional persons as interpersonal aid workers

New Insights into SNR Evolution Revealed by the Discovery of Recombining Plasmas

We report the discovery of recombining plasmas in three supernova remnants (SNRs) with the Suzaku X-ray astronomy satellite. During SNR's evolution, the expanding supernova ejecta and the ambient matter are compressed and heated by the reverse and forward shocks to form an X-ray emitting hot plasma. Since ionization proceeds slowly compared to shock heating, most young or middle-aged SNRs have ionizing (underionized) plasmas. Owing to high sensitivity of Suzaku, however, we have detected radiative recombination continua (RRCs) from the SNRs IC 443, W49B, and G359.1-0.5. The presence of the strong RRC is the definitive evidence that the plasma is recombining (overionized). As a possible origin of the overionization, an interaction between the ejecta and dense circumstellar matter is proposed; the highly ionized gas was made at the initial phase of the SNR evolution in dense regions, and subsequent rapid adiabatic expansion caused sudden cooling of the electrons. The analysis on the full X-ray band spectrum of IC 443, which is newly presented in this paper, provides a consistent picture with this scenario. We also comment on the implications from the fact that all the SNRs having recombining plasmas are correlated with the mixed-morphology class.Comment: Published by Advances in Space Researc

The association of ectopic craniopharyngioma in the fourth ventricle with familial adenomatous polyposis: illustrative case

[BACKGROUND] Craniopharyngioma (CP) often arises in the sellar and suprasellar areas; ectopic CP in the posterior fossa is rare. Familial adenomatous polyposis (FAP) is a genetic disorder involving the formation of numerous adenomatous polyps in the gastrointestinal tract, and it is associated with other extraintestinal manifestations. [OBSERVATIONS] The authors reported the case of a 63-year-old woman with FAP who presented with headache and harbored a growing mass in the fourth ventricle. Magnetic resonance imaging (MRI) findings revealed a well-circumscribed mass with high intensity on T1-weighted images and low intensity on T2-weighted images and exhibited no contrast enhancement. Gross total resection was performed and histopathology revealed an adamantinomatous CP (aCP). The authors also reviewed the previous reports of ectopic CP in the posterior fossa and found a high percentage of FAP cases among the ectopic CP group, thus suggesting a possible association between the two diseases. [LESSONS] An ectopic CP may be reasonably included in the differential diagnosis in patients with FAP who present with well-circumscribed tumors in the posterior fossa

The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies

We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of $0.015-0.195~Z_\odot$ and low stellar masses of $10^4-10^8~M_\odot$ in the local universe. We conduct deep optical integral-field spectroscopy (IFS) for the low-mass EMPGs with the medium high resolution ($R=7500$) grism of the 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate H$\alpha$ emission of the EMPGs. Exploiting the resolution high enough for the low-mass galaxies, we derive gas dynamics with the H$\alpha$ lines by the fitting of 3-dimensional disk models. We obtain an average maximum rotation velocity ($v_\mathrm{rot}$) of $15\pm3~\mathrm{km~s^{-1}}$ and an average intrinsic velocity dispersion ($\sigma_0$) of $27\pm10~\mathrm{km~s^{-1}}$ for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have $v_\mathrm{rot}/\sigma_0<1$ suggesting dispersion dominated systems. There is a clear decreasing trend of $v_\mathrm{rot}/\sigma_0$ with the decreasing stellar mass and metallicity. We derive the gas mass fraction ($f_\mathrm{gas}$) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These $v_\mathrm{rot}/\sigma_0$ and $f_\mathrm{gas}$ trends should be compared with young high-$z$ galaxies observed by the forthcoming JWST IFS programs to understand the physical origins of the EMPGs in the local universe.Comment: 18 pages, 9 figures, accepted for publication in Ap

EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?

We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities ($0.016-0.098\ Z_{\odot}$) and low stellar masses ($10^{4.7}-10^{7.6} M_{\odot}$). Taking deep medium-high resolution ($R\sim7500$) integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with H$\alpha$ emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed H$\alpha$ flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities ($v_{\rm rot}$) of 5--23 km s$^{-1}$ smaller than the velocity dispersions ($\sigma_{0}$) of 17--31 km s$^{-1}$, indicating dispersion-dominated ($v_{\rm rot}/\sigma_{0}=0.29-0.80<1$) systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of $f_{\rm gas}\simeq 0.9-1.0$. Comparing our results with other H$\alpha$ kinematics studies, we find that $v_{\rm rot}/\sigma_{0}$ decreases and $f_{\rm gas}$ increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high-$z$ ($z\sim 7$) forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at $z\sim 7$.Comment: Submitted to ApJ; After revisio

Preoperative biliary drainage for biliary tract and ampullary carcinomas

We posed six clinical questions (CQ) on preoperative biliary drainage and organized all pertinent evidence regarding these questions. CQ 1. Is preoperative biliary drainage necessary for patients with jaundice? The indications for preoperative drainage for jaundiced patients are changing greatly. Many reports state that, excluding conditions such as cholangitis and liver dysfunction, biliary drainage is not necessary before pancreatoduodenectomy or less invasive surgery. However, the morbidity and mortality of extended hepatectomy for biliary cancer is still high, and the most common cause of death is hepatic failure; therefore, preoperative biliary drainage is desirable in patients who are to undergo extended hepatectomy. CQ 2. What procedures are appropriate for preoperative biliary drainage? There are three methods of biliary drainage: percutaneous transhepatic biliary drainage (PTBD), endoscopic nasobiliary drainage (ENBD) or endoscopic retrograde biliary drainage (ERBD), and surgical drainage. ERBD is an internal drainage method, and PTBD and ENBD are external methods. However, there are no reports of comparisons of preoperative biliary drainage methods using randomized controlled trials (RCTs). Thus, at this point, a method should be used that can be safely performed with the equipment and techniques available at each facility. CQ 3. Which is better, unilateral or bilateral biliary drainage, in malignant hilar obstruction? Unilateral biliary drainage of the future remnant hepatic lobe is usually enough even when intrahepatic bile ducts are separated into multiple units due to hilar malignancy. Bilateral biliary drainage should be considered in the following cases: those in which the operative procedure is difficult to determine before biliary drainage; those in which cholangitis has developed after unilateral drainage; and those in which the decrease in serum bilirubin after unilateral drainage is very slow. CQ 4. What is the best treatment for postdrainage fever? The most likely cause of high fever in patients with biliary drainage is cholangitis due to problems with the existing drainage catheter or segmental cholangitis if an undrained segment is left. In the latter case, urgent drainage is required. CQ 5. Is bile culture necessary in patients with biliary drainage who are to undergo surgery? Monitoring of bile cultures is necessary for patients with biliary drainage to determine the appropriate use of antibiotics during the perioperative period. CQ 6. Is bile replacement useful for patients with external biliary drainage? Maintenance of the enterohepatic bile circulation is vitally important. Thus, preoperative bile replacement in patients with external biliary drainage is very likely to be effective when highly invasive surgery (e.g., extended hepatectomy for hilar cholangiocarcinoma) is planned

Flowcharts for the management of biliary tract and ampullary carcinomas

No strategies for the diagnosis and treatment of biliary tract carcinoma have been clearly described. We developed flowcharts for the diagnosis and treatment of biliary tract carcinoma on the basis of the best clinical evidence. Risk factors for bile duct carcinoma are a dilated type of pancreaticobiliary maljunction (PBM) and primary sclerosing cholangitis. A nondilated type of PBM is a risk factor for gallbladder carcinoma. Symptoms that may indicate biliary tract carcinoma are jaundice and pain in the upper right area of the abdomen. The first step of diagnosis is to carry out blood biochemistry tests and ultrasonography (US) of the abdomen. The second step of diagnosis is to find the local extension of the carcinoma by means of computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP). Because resection is the only way to completely cure biliary tract carcinoma, the indications for resection are determined first. In patients with resectable disease, the indications for biliary drainage or portal vein embolization (PVE) are checked. In those with nonresectable disease, biliary stenting, chemotherapy, radiotherapy, and/or best supportive care is selected

Guidelines for the management of biliary tract and ampullary carcinomas: surgical treatment

The only curative treatment in biliary tract cancer is surgical treatment. Therefore, the suitability of curative resection should be investigated in the first place. In the presence of metastasis to the liver, lung, peritoneum, or distant lymph nodes, curative resection is not suitable. No definite consensus has been reached on local extension factors and curability. Measures of hepatic functional reserve in the jaundiced liver include future liver remnant volume and the indocyanine green (ICG) clearance test. Preoperative portal vein embolization may be considered in patients in whom right hepatectomy or more, or hepatectomy with a resection rate exceeding 50%–60% is planned. Postoperative complications and surgery-related mortality may be reduced with the use of portal vein embolization. Although hepatectomy and/or pancreaticoduodenectomy are preferable for the curative resection of bile duct cancer, extrahepatic bile duct resection alone is also considered in patients for whom it is judged that curative resection would be achieved after a strict diagnosis of its local extension. Also, combined caudate lobe resection is recommended for hilar cholangiocarcinoma. Because the prognosis of patients treated with combined portal vein resection is significantly better than that of unresected patients, combined portal vein resection may be carried out. Prognostic factors after resection for bile duct cancer include positive surgical margins, especially in the ductal stump; lymph node metastasis; perineural invasion; and combined vascular resection due to portal vein and/or hepatic artery invasion. For patients with suspected gallbladder cancer, laparoscopic cholecystectomy is not recommended, and open cholecystectomy should be performed as a rule. When gallbladder cancer invading the subserosal layer or deeper has been detected after simple cholecystectomy, additional resection should be considered. Prognostic factors after resection for gallbladder cancer include the depth of mural invasion; lymph node metastasis; extramural extension, especially into the hepatoduodenal ligament; perineural invasion; and the degree of curability. Pancreaticoduodenectomy is indicated for ampullary carcinoma, and limited operation is also indicated for carcinoma in adenoma. The prognostic factors after resection for ampullary carcinoma include lymph node metastasis, pancreatic invasion, and perineural invasion