193 research outputs found
AKARI IRC 2.5-5 um Spectroscopy of Infrared Galaxies over a Wide Luminosity Range
We present the result of a systematic infrared 2.5-5 um spectroscopic study
of 22 nearby infrared galaxies over a wide infrared luminosity range (10 <
log(L_IR / Lsun) < 13) obtained from AKARI Infrared Camera (IRC). The unique
band of the AKARI IRC spectroscopy enables us to access both the 3.3 um
polycyclic aromatic hydrocarbon (PAH) emission feature from star forming
activity and the continuum of torus-dust emission heated by an active galactic
nucleus (AGN). Applying our AGN diagnostics to the AKARI spectra, we discover
14 buried AGNs. The large fraction of buried AGNs suggests that AGN activity
behind the dust is almost ubiquitous in ultra-/luminous infrared galaxies
(U/LIRGs). We also find that both the fraction and energy contribution of
buried AGNs increase with infrared luminosity from 10 < log(L_IR / Lsun) < 13,
including normal infrared galaxies with log (L_IR / Lsun) < 11. The energy
contribution from AGNs in the total infrared luminosity is only ~7% in LIRGs
and ~20% in ULIRGs, suggesting that the majority of the infrared luminosity
originates from starburst activity. Using the PAH emission, we investigate the
luminosity relation between star formation and AGN. We find that these infrared
galaxies exhibit higher star formation rates than optically selected Seyfert
galaxies with the same AGN luminosities, implying that infrared galaxies could
be an early evolutionary phase of AGN.Comment: 13 pages, 8 figures, accepted for publication in Ap
Emergency EC-IC bypass for symptomatic atherosclerotic ischemic stroke
Previous studies have shown that extracranial-intracranial (EC-IC) bypass surgery has no preventive effect on subsequent ipsilateral ischemic stroke in patients with symptomatic atherosclerotic internal carotid occlusion and hemodynamic cerebral ischemia. A few studies have assessed whether an urgent EC-IC bypass surgery is an effective treatment for main trunk stenosis or occlusion in acute stage. The authors retrospectively reviewed 58 consecutive patients who underwent urgent EC-IC bypass for symptomatic internal carotid artery or the middle cerebral artery stenosis or occlusion between January 2003 and December 2011. Clinical characteristics and neuroimagings were evaluated and analyzed. Based on preoperative angiogram, responsible lesions were the internal carotid artery in 19 (32.8 %) patients and the middle cerebral artery in 39 (67.2 %). No hemorrhagic complication occurred. Sixty-nine percent of patients showed improvement of neurological function after surgery, and 74.1 % of patients had favorable outcome. Unfavorable outcome was associated with insufficient collateral flow and new infarction after bypass surgery.ArticleNEUROSURGICAL REVIEW. 36(4):559-564 (2013)journal articl
Infrared and hard X-ray diagnostics of AGN identification from the Swift/BAT and AKARI all-sky surveys
We combine data from two all-sky surveys in order to study the connection
between the infrared and hard X-ray (>10keV) properties for local active
galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides
an unbiased, flux-limited selection of hard X-ray detected AGN.
Cross-correlating the 22-month hard X-ray survey with the AKARI all-sky survey,
we studied 158 AGN detected by the AKARI instruments. We find a strong
correlation for most AGN between the infrared (9, 18, and 90 micron) and hard
X-ray (14-195 keV) luminosities, and quantify the correlation for various
subsamples of AGN. Partial correlation analysis confirms the intrinsic
correlation after removing the redshift contribution. The correlation for radio
galaxies has a slope and normalization identical to that for Seyfert 1s,
implying similar hard X-ray/infrared emission processes in both. In contrast,
Compton-thick sources show a large deficit in the hard X-ray band, because high
gas column densities diminish even their hard X-ray luminosities. We propose
two photometric diagnostics for source classification: one is an X-ray
luminosity vs. infrared color diagram, in which type 1 radio-loud AGN are well
isolated from the others in the sample. The other uses the X-ray vs. infrared
color as a useful redshift-independent indicator for identifying Compton-thick
AGN. Importantly, Compton-thick AGN and starburst galaxies in composite systems
can also be differentiated in this plane based upon their hard X-ray fluxes and
dust temperatures. This diagram may be useful as a new indicator to classify
objects in new and upcoming surveys such as WISE and NuSTAR.Comment: 17 pages, 5 figures, 5 tables. Accepted for publication in the
Astrophysical Journa
Associations among Preoperative Malnutrition, Muscle Loss, and Postoperative Walking Ability in Intertrochanteric Fractures: A Retrospective Study
Sarcopenia and malnutrition are increasing in older adults and are reported risk factors for functional impairment after hip fracture surgery. This study aimed to investigate the associations between skeletal muscle mass loss, malnutrition, and postoperative walking ability in patients with hip fracture. We retrospectively reviewed patients who underwent intertrochanteric fracture surgery at our institute. The psoas muscle index, controlling nutritional status score, and functional ambulation category (FAC) were used to evaluate skeletal muscle mass, nutritional status, and walking ability, respectively. Six months after surgery, walking ability was assessed as either “gait disturbance” or “independent gait”. Multivariate binomial logistic regression analysis, with skeletal muscle mass, nutritional status, and other factors, was used to predict the risk of being assigned to the gait disturbance group. This study included 95 patients (mean age, 85.2 years; 70 women). Sixty-six patients had low skeletal muscle mass, 35 suffered from malnutrition, and 28 had both. Malnutrition and low skeletal muscle mass were significantly associated with postoperative gait disturbance (FAC < 3). Preoperative low skeletal muscle mass and malnutrition were risk factors for postoperative poor walking ability. Further preventive interventions focusing on skeletal muscle mass and nutritional status are required
PRRX1 promotes malignant properties in human osteosarcoma
Paired related homeobox 1 (PRRX1) is a marker of limb bud mesenchymal cells, and deficiency of p53 or Rb in Prrx1-positive cells induces osteosarcoma in several mouse models. However, the regulatory roles of PRRX1 in human osteosarcoma have not been defined. In this study, we performed PRRX1 immunostaining on 35 human osteosarcoma specimens to assess the correlation between PRRX1 level and overall survival. In patients with osteosarcoma, the expression level of PRRX1 positively correlated with poor prognosis or the ratio of lung metastasis. Additionally, we found PRRX1 expression on in 143B cells, a human osteosarcoma line with a high metastatic capacity. Downregulation of PRRX1 not only suppressed proliferation and invasion but also increased the sensitivity to cisplatin and doxorubicin. When 143B cells were subcutaneously transplanted into nude mice, PRRX1 knockdown decreased tumor sizes and rates of lung metastasis. Interestingly, forskolin, a chemical compound identified by Connectivity Map analysis using RNA expression signatures during PRRX1 knockdown, decreased tumor proliferation and cell migration to the same degree as PRRX1 knockdown. These results demonstrate that PRRX1 promotes tumor malignancy in human osteosarcoma
Broken Screw Rotational Symmetry in the Near-Surface Electronic Structure of -Stacked Crystals
We investigate the electronic structure of - and
by angle-resolved photoemission spectroscopy (ARPES) and
photoemission intensity calculations. Although in bulk form, these materials
are expected to exhibit band degeneracy in the plane due to screw
rotation and time-reversal symmetries, we observe gapped band dispersion near
the surface. We extract from first-principles calculations the near-surface
electronic structure probed by ARPES and find that the calculated photoemission
spectra from the near-surface region reproduce the gapped ARPES spectra. Our
results show that the near-surface electronic structure can be qualitatively
different from the bulk one due to partially broken nonsymmorphic symmetries.Comment: 6+11 pages, 4+13 figure
Synthesis of (difluoromethyl)naphthalenes using the ring construction strategy: C–C bond formation on the central carbon of 1,1-difluoroallenes via Pd-catalyzed insertion
The insertion of 1,1-difluoroallenes was carried out to form a C–C bond exclusively on their central carbon. o-Bromophenyl-bearing 1,1-difluoroallenes underwent intramolecular insertion in the presence of a palladium catalyst. Regioselective C–C bond formation occurred to form a six-membered carbocycle, leading to pharmaceutically and agrochemically promising difluoromethylated naphthalenes
Combined Laparoscopic and CT Monitoring of the Ice-Ball Margin during Cryoablation for Renal Cell Carcinoma Associated with von Hippel-Lindau Disease: First Case
We report a 47-year-old Japanese female with 10 previous treatments for multiple bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau disease. The 14-mm right lower pole renal tumor was in contact with the right ureter. Laparoscopic cryoablation was performed to protect the ureter wrapped with gauze. Computed tomography (CT) monitoring was used to confirm the precise ≥ 6 mm ice-ball margin. There was no local progression at 6-months post-surgery. The serum creatinine has been stable. This is apparently the first report of combined laparoscopic and CT monitoring of an ice-ball formation and its margin during cryoablation for RCC
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