Superconducting mechanism for the cuprate Ba2_2CuO3+δ_{3+\delta} based on a multiorbital Lieb lattice model

For the recently discovered cuprate superconductor $\mathrm{Ba_{2}CuO_{3+\delta}}$, we propose a lattice structure which resembles the model considered by Lieb to represent the vastly oxygen-deficient material. We first investigate the stability of the Lieb-lattice structure, and then construct a multiorbital Hubbard model based on first-principles calculation. By applying the fluctuation-exchange approximation to the model and solving the linearized Eliashberg equation, we show that $s$-wave and $d$-wave pairings closely compete with each other, and, more interestingly, that the intra-orbital and inter-orbital pairings coexist. We further show that, if the energy of the $d_{3z^2-r^2}$ band is raised to make it "incipient" with the lower edge of the band close to the Fermi level within a realistic band filling regime, $s\pm$-wave superconductivity is strongly enhanced. We reveal an intriguing relation between the Lieb model and the two-orbital model for the usual K$_2$NiF$_4$ structure where a close competition between $s-$ and $d-$wave pairings is known to occur. The enhanced superconductivity in the present model is further shown to be related to an enhancement found previously in the bilayer Hubbard model with an incipient band.Comment: 19 pages, 20 figures; references and figures update

HIGH-DOSE-RATE AFTERLOADING INTRACAVITARY IRRADIATION AND EXPANDABLE METALLIC BILIARY ENDOPROSTHESIS FOR MALIGNANT BILIARY OBSTRUCTION

A double lumen catheter was developed as an applicator for the remote afterloading system (RALS) of ⁶⁰Co for the intracavitary irradiation of an obstructed common bile duct due to gallbladder cancer in 1 case and by cholangiocarcinoma in 7 cases. This was followed by the biliary endoprosthesis with expandable metallic stents to maintain patency. The mean survival period after treatment was not long (14 weeks). However, removal of the external drainage tube was possible in 7 of the 8 cases, and none of the 8 cases showed dislodgement or deformity of the stent, or obstruction of the bile duct in the stent-inserted area. This combination effectively provided palliation, and has considerable potential for malignant biliary obstruction

(MRS)31P Magnetic Resonance Spectroscopy of Perfused Rat Skeletal Muscle

雄ラットの大腿二頭筋のホスホクレアチン(PCr),ATP,無機リン(Pi)および細胞内pH(pHi)を31P-MRSで測定した.遊離筋の灌流中止時にはPCrとpHiは低下し,Piは増加したがATPはほぼ不変であった.灌流再開後,PCrとPiは前値に復帰した.虚血中のpHiの低下はPCrの減少より緩やかであった.PCrが前値の約1/2に減少した時,pHiは下降し始めた.以上は,PCrはラット大腿二頭筋のような典型的な急速収縮筋における虚血早期のpHi緩衝の役割を持っていることを示唆している雄ラットの大腿二頭筋のホスホクレアチン(PCr),ATP,無機リン(Pi)および細胞内pH(pHi)を31P-MRSで測定した.遊離筋の灌流中止時にはPCrとpHiは低下し,Piは増加したがATPはほぼ不変であった.灌流再開後,PCrとPiは前値に復帰した.虚血中のpHiの低下はPCrの減少より緩やかであった.PCrが前値の約1/2に減少した時,pHiは下降し始めた.以上は,PCrはラット大腿二頭筋のような典型的な急速収縮筋における虚血早期のpHi緩衝の役割を持っていることを示唆している雄ラットの大腿二頭筋のホスホクレアチン(PCr),ATP,無機リン(Pi)および細胞内pH(pHi)を31P-MRSで測定した.遊離筋の灌流中止時にはPCrとpHiは低下し,Piは増加したがATPはほぼ不変であった.灌流再開後,PCrとPiは前値に復帰した.虚血中のpHiの低下はPCrの減少より緩やかであった.PCrが前値の約1/2に減少した時,pHiは下降し始めた.以上は,PCrはラット大腿二頭筋のような典型的な急速収縮筋における虚血早期のpHi緩衝の役割を持っていることを示唆している雄ラットの大腿二頭筋のホスホクレアチン(PCr),ATP,無機リン(Pi)および細胞内pH(pHi)を31P-MRSで測定した.遊離筋の灌流中止時にはPCrとpHiは低下し,Piは増加したがATPはほぼ不変であった.灌流再開後,PCrとPiは前値に復帰した.虚血中のpHiの低下はPCrの減少より緩やかであった.PCrが前値の約1/2に減少した時,pHiは下降し始めた.以上は,PCrはラット大腿二頭筋のような典型的な急速収縮筋における虚血早期のpHi緩衝の役割を持っていることを示唆してい

Increase in stenotic resistance following a brief coronary occlusion in the anesthetized open-chest dog.

Changes in the stenotic resistance of a coronary artery following brief coronary occlusion were studied in the anesthetized open-chest dog. A critical coronary stenosis was constructed by tying a thick string around the circumflex coronary artery (LCx) near its origin. The LCx was occluded for 5, 10, 15, 20 and 30 seconds with and without coronary stenosis then the reactive hyperemia was observed. In the absence of the stenosis, resistance of the segment of the large coronary artery remained unchanged during the reactive hyperemia independent of the duration of occlusion. In the presence of the stenosis, however, stenotic resistance increased for a certain time after the release of occlusion. This increased resistance lasted longer with more severe stenosis and with longer duration of coronary occlusion. These results suggest that stenotic resistance can increase dynamically, and that the duration of increased resistance may reflect the severity of the stenosis.</p

Hyper-luminous Dust Obscured Galaxies discovered by the Hyper Suprime-Cam on Subaru and WISE

We present the photometric properties of a sample of infrared (IR) bright dust obscured galaxies (DOGs). Combining wide and deep optical images obtained with the Hyper Suprime-Cam (HSC) on the Subaru Telescope and all-sky mid-IR (MIR) images taken with Wide-Field Infrared Survey Explorer (WISE), we discovered 48 DOGs with $i - K_\mathrm{s} > 1.2$ and $i - [22] > 7.0$, where $i$, $K_\mathrm{s}$, and [22] represent AB magnitude in the $i$-band, $K_\mathrm{s}$-band, and 22 $\mu$m, respectively, in the GAMA 14hr field ($\sim$ 9 deg$^2$). Among these objects, 31 ($\sim$ 65 %) show power-law spectral energy distributions (SEDs) in the near-IR (NIR) and MIR regime, while the remainder show a NIR bump in their SEDs. Assuming that the redshift distribution for our DOGs sample is Gaussian, with mean and sigma $z$ = 1.99 $\pm$ 0.45, we calculated their total IR luminosity using an empirical relation between 22 $\mu$m luminosity and total IR luminosity. The average value of the total IR luminosity is (3.5 $\pm$ 1.1) $\times$ $10^{13}$ L$_{\odot}$, which classifies them as hyper-luminous infrared galaxies (HyLIRGs). We also derived the total IR luminosity function (LF) and IR luminosity density (LD) for a flux-limited subsample of 18 DOGs with 22 $\mu$m flux greater than 3.0 mJy and with $i$-band magnitude brighter than 24 AB magnitude. The derived space density for this subsample is log $\phi$ = -6.59 $\pm$ 0.11 [Mpc$^{-3}$]. The IR LF for DOGs including data obtained from the literature is well fitted by a double-power law. The derived lower limit for the IR LD for our sample is $\rho_{\mathrm{IR}}$ $\sim$ 3.8 $\times$ 10$^7$ [L$_{\odot}$ Mpc$^{-3}$] and its contributions to the total IR LD, IR LD of all ultra-luminous infrared galaxies (ULIRGs), and that of all DOGs are $>$ 3 %, $>$ 9 %, and $>$ 15 %, respectively.Comment: 15 pages, 15 figures, and 3 tables, accepted for publication in PASJ (Subaru special issue

Increase in the resistance of stenotic coronary segment by intravenous infusion of isoproterenol.

The effects of intravenous infusion of isoproterenol on stenosis resistance were studied in the anesthetized open-chest dog. The circumflex coronary artery (LCx) was isolated near its origin and an electromagnetic flow transducer was placed around the vessel for measuring coronary flow. A polyethylene catheter was inserted into the small branch of LCx for monitoring distal coronary pressure. LCx was constricted with a thick cotton string to a degree of obstruction that eliminated reactive hyperemia following a 20-second coronary occlusion. The coronary resistance across the stenotic segment (RL) was calculated as the pressure gradient across the stenosis divided by coronary flow. Isoproterenol was infused intravenously in a dose to keep the heart rate at a level 25-30% above the control with and without coronary constriction. For maintaining the ascending aortic pressure at the pre-isoproterenol level, the descending thoracic aorta was constricted with a tape. In the absence of coronary constriction, the vascular resistance of large coronary arteries was not affected by isoproterenol with a significant increase in coronary flow. In the presence of coronary stenosis, isoproterenol markedly increased RI regardless of additional aortic constriction. The magnitude of the increase in RL during aortic constriction varied directly with the percent increase in the pressure gradient across the coronary stenosis. Pacing-tachycardia essentially did not affect RL. These results suggest that isoproterenol increased the vascular resistance of the stenotic segment with fixed caliber.</p

Synergistic Formation of Radicals by Irradiation with Both Vacuum Ultraviolet and Atomic Hydrogen: A Real-Time In Situ Electron Spin Resonance Study

We report on the surface modification of polytetrafluoroethylene (PTFE) as an example of soft- and bio-materials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification.Comment: 14 pages, 4 figure