93 research outputs found
On the calculation of the James constant of Lorentz sequence spaces
In [M. Kato and L. Maligranda, On James and Jordan-von Neumannconstants of Lorentz sequence spaces, J. Math. Anal. Appl., 258(2001), 457–465], theJames constant of the 2-dimensional Lorentz sequence space d(2)(!; q) is computed inthe case where 2 · q < 1. It is an open problem to compute it in the case where1 · q < 2. In this paper, we completely determine the James constant of d(2)(!; q) inthe case where 1 · q < 2
Structural and infrared spectral changes of silicon oxide grains by heat treatments
In order to elucidate the relationship between crystallographic structures of amorphous silicon oxide grains and infrared (IR) spectra, ultrafine grains produced by the gas evaporation method have been studied on the basis of IR spectral measurements and electron microscopic (EM) observations. The shifts and disappearance in the IR absorption peaks of specimen heat-treated in air have been found. The spectral changes have been discussed in the relation with the polymorphism of silica
Characterization of highly efficient heavy-ion mutagenesis in Arabidopsis thaliana
<p>Abstract</p> <p>Background</p> <p>Heavy-ion mutagenesis is recognised as a powerful technology to generate new mutants, especially in higher plants. Heavy-ion beams show high linear energy transfer (LET) and thus more effectively induce DNA double-strand breaks than other mutagenic techniques. Previously, we determined the most effective heavy-ion LET (LET<sub>max</sub>: 30.0 keV μm<sup>-1</sup>) for <it>Arabidopsis </it>mutagenesis by analysing the effect of LET on mutation induction. However, the molecular structure of mutated DNA induced by heavy ions with LET<sub>max </sub>remains unclear. Knowledge of the structure of mutated DNA will contribute to the effective exploitation of heavy-ion beam mutagenesis.</p> <p>Results</p> <p>Dry <it>Arabidopsis thaliana </it>seeds were irradiated with carbon (C) ions with LET<sub>max </sub>at a dose of 400 Gy and with LET of 22.5 keV μm<sup>-1 </sup>at doses of 250 Gy or 450 Gy. The effects on mutation frequency and alteration of DNA structure were compared. To characterise the structure of mutated DNA, we screened the well-characterised mutants <it>elongated hypocotyls </it>(<it>hy</it>) and <it>glabrous </it>(<it>gl</it>) and identified mutated DNA among the resulting mutants by high-resolution melting curve, PCR and sequencing analyses. The mutation frequency induced by C ions with LET<sub>max </sub>was two-fold higher than that with 22.5 keV μm<sup>-1 </sup>and similar to the mutation frequency previously induced by ethyl methane sulfonate. We identified the structure of 22 mutated DNAs. Over 80% of the mutations caused by C ions with both LETs were base substitutions or deletions/insertions of less than 100 bp. The other mutations involved large rearrangements.</p> <p>Conclusions</p> <p>The C ions with LET<sub>max </sub>showed high mutation efficiency and predominantly induced base substitutions or small deletions/insertions, most of which were null mutations. These small alterations can be determined by single-nucleotide polymorphism (SNP) detection systems. Therefore, C ions with LET<sub>max </sub>might be useful as a highly efficient reverse genetic system in conjunction with SNP detection systems, and will be beneficial for forward genetics and plant breeding.</p
Conversion therapy for unresectable hepatocellular carcinoma after lenvatinib : Three case reports
Introduction: Lenvatinib (LEN) is a novel potent multi-tyrosine kinase inhibitor, approved as first-line treatment for unresectable hepatocellular carcinoma (HCC). Considering its high objective response rate, LEN therapy could be expected to achieve downstaging of tumors and lead to conversion therapy with hepatectomy or ablation. However, the feasibility of conversion therapy after LEN treatment in unresectable HCC remains largely unknown.
Patient concerns: Here, we reported 3 cases of unresectable HCC: case 1, a 69-year-old man diagnosed with ruptured HCC; case 2, a 72-year-old woman with nonalcoholic steatohepatitis-based HCC; and case 3, a 73-year-old man with a history of alcoholic cirrhosis-based HCC.
Diagnosis: In all cases, cirrhosis was classified as Child-Pugh 5 and modified albumin-bilirubin grade 1 or 2a. HCC was diagnosed as Barcelona Clinic Liver Cancer (BCLC) stage B.
Interventions: In all cases, LEN was initiated after conventional-transcatheter arterial embolization enforcement, while maintaining liver function.
Outcomes: In all cases, the main tumor size decreased after 6 months of LEN treatment and no satellite nodes were detected, indicating downstaging of HCC to BCLC stage A. Subsequently, conversion hepatectomy or ablation was performed. After successful conversion therapy, the general condition of the patients was good, without tumor recurrence during the observation period (median 10 months).
Lessons: This study demonstrated that LEN enables downstaging of HCC and thus represents a bridge to successful surgery or ablation therapy. In particular, LEN treatment may facilitate the possibility for conversion therapy of initially unresectable HCC, while maintaining the hepatic functional reserve
A high dust emissivity index beta for a CO-faint galaxy in a filamentary Lyman-alpha nebula at z=3.1
We present CO J=4-3 line and 3 mm dust continuum observations of a 100
kpc-scale filamentary Ly{\alpha} nebula (SSA22 LAB18) at z=3.1 using the
Atacama Large Millimeter/submillimeter Array (ALMA). We detected the CO J=4-3
line at a systemic z(CO)=3.093 {\pm} 0.001 at 11 {\sigma} from one of the ALMA
continuum sources associated with the Ly{\alpha} filament. We estimated the CO
J=4-3 luminosity of L'CO(4-3)=(2.3\pm0.2)x10^9 K km s^{-1} pc^2 for this CO
source, which is one order of magnitude smaller than those of typical z>1 dusty
star-forming galaxies (DSFGs) of similar far-infrared luminosity L(IR)~10^{12}
Lsun. We derived a molecular gas mass of Mgas=(4.4^{+0.9}_{-0.6})x10^9 Msun and
a star-formation rate of SFR=270\pm160 Msun yr^{-1}. We also estimated a gas
depletion time of {\tau}(dep)=17\pm10 Myr, being shorter than those of typical
DSFGs. It is suggested that this source is in a transition phase from DSFG to a
gas-poor, early-type galaxy. From ALMA to Herschel multi-band dust continuum
observations, we measured a dust emissivity index {\beta}=2.3\pm0.2, which is
similar to those of local gas-poor, early-type galaxies. Such a high {\beta}
can be reproduced by specific chemical compositions for interstellar dust at
the submillimeter wavelengths from recent laboratory experiments. ALMA CO and
multi-band dust continuum observations can constrain the evolutionary stage of
high-redshift galaxies through {\tau}(dep) and {\beta}, and thus we can
investigate dust chemical compositions even in the early Universe.Comment: 6 pagers, 3 figure
How many times can patients tolerate reoperation?
The frequency of resection for the recurrence of colorectal cancer has not been investigated in previous studies. Likewise, the related postoperative complications and the limit for indicating surgical resection has not been reported. Herein, we reported the complications of a highly frequent surgical approach for rectal cancer recurrence, i.e., exceeding three reoperations, based on our clinical experience. We included 15 cases exceeding two operations for the local recurrence of colorectal cancer from 2014 to 2019. We examined the postoperative complications classified as Clavien–Dindo IIIb. The positive rates of the complications were 0 (0.0%), 0 (0.0%), 2 (13.3%), 3 (37.5%), and 0 (0.0%) for the primary, 1st recurrent, 2nd recurrent, 3rd recurrent, and 4th recurrent operation group (p = 0.027), respectively. It is important to exercise caution in handling cases exceeding two reoperations (exceeding three reoperations including the primary operation)
A gravitationally unstable gas disk of a starburst galaxy 12 billion years ago
Submillimeter bright galaxies in the early Universe are vigorously forming
stars at ~1000 times higher rate than the Milky Way. A large fraction of stars
is formed in the central 1 kiloparsec region, that is comparable in size to
massive, quiescent galaxies found at the peak of the cosmic star formation
history, and eventually the core of giant elliptical galaxies in the
present-day Universe. However, the physical and kinematic properties inside a
compact starburst core are poorly understood because dissecting it requires
angular resolution even higher than the Hubble Space Telescope can offer. Here
we report 550 parsec-resolution observations of gas and dust in the brightest
unlensed submillimeter galaxy at z=4.3. We map out for the first time the
spatial and kinematic structure of molecular gas inside the heavily
dust-obscured core. The gas distribution is clumpy while the underlying disk is
rotation-supported. Exploiting the high-quality map of molecular gas mass
surface density, we find a strong evidence that the starburst disk is
gravitationally unstable, implying that the self-gravity of gas overcomes the
differential rotation and the internal pressure by stellar radiation feedback.
The observed molecular gas would be consumed by star formation in a timescale
of 100 million years, that is comparable to those in merging starburst
galaxies. Our results suggest that the most extreme starburst in the early
Universe originates from efficient star formation due to a gravitational
instability in the central 2 kpc region.Comment: Published in Nature on August 30 2018 (submitted version
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