500 research outputs found
Influence of Pores on Wettability of Zirconia Ceramic by Molten Manganese
A basic research study for improvement of plasma-sprayed zirconia coatings has been conducted. Wettability of porous Zr02-Y203 -Mn0 substrates by manganese has been investigated at 1573K by the sessile drop method. The contact angles tend to decrease gradually and stabilized at 85-90 degrees. Those values are larger than that for dense substrate. Thus the pores have a great influence on kinetics of wetting. / プラズマ溶射したセラミック皮膜の改善を目的として、多孔質セラミックと溶融マンガンの塗れ性を調べた。平滑なセラミックに比べて見かけ上ぬれにくく、平衡到達まで長時間を要することを明らかにした
Chordotonal organs in hemipteran insects: unique peripheral structures but conserved central organization revealed by comparative neuroanatomy
Hemipteran insects use sophisticated vibrational communications by striking body appendages on the substrate or by oscillating the abdominal tymbal. There has been, however, little investigation of sensory channels for processing vibrational signals. Using sensory nerve stainings and low invasive confocal analyses, we demonstrate the comprehensive neuronal mapping of putative vibration-responsive chordotonal organs (COs) in stink bugs (Pentatomidae and Cydinidae) and cicadas (Cicadidae). The femoral CO (FCO) in stink bugs consists of ventral and dorsal scoloparia, homologous to distal and proximal scoloparia in locusts, which are implicated in joint movement detection and vibration detection, respectively. The ligament of the dorsal scoloparium is distally attached to the accessory extensor muscle, whereas that of the ventral scoloparium is attached to a specialized tendon. Their afferents project to the dorso-lateral neuropil and the central region of the medial ventral association center (mVAC) in the ipsilateral neuromere, where presumed dorsal scoloparium afferents and subgenual organ afferents are largely intermingled. In contrast, FCOs in cicadas have decreased dorsal scoloparium neurons and lack projections to the mVAC. The tymbal CO of stink bugs contains four sensory neurons that are distally attached to fat body cells via a ligament. Their axons project intersegmentally to the dorsal region of mVACs in all neuromeres. Together with comparisons of COs in different insect groups, the results suggest that hemipteran COs have undergone structural modification for achieving faster signaling of resonating peripheral tissues. The conserved projection patterns of COs suggest functional importance of the FCO and subgenual organ for vibrational communications
Comet 9P/Tempel 1: Interpretation with the Deep Impact Results
According to our common understandings, the original surface of a
short-period comet nucleus has been lost by sublimation processes during its
close approaches to the Sun. Sublimation results in the formation of a dust
mantle on the retreated surface and in chemical differentiation of ices over
tens or hundreds of meters below the mantle. In the course of NASA's Deep
Impact mission, optical and infrared imaging observations of the ejecta plume
were conducted by several researchers, but their interpretations of the data
came as a big surprise: (1) The nucleus of comet 9P/Tempel 1 is free of a dust
mantle, but maintains its pristine crust of submicron-sized carbonaceous
grains; (2) Primordial materials are accessible already at a depth of several
tens of cm with abundant silicate grains of submicrometer sizes. In this study,
we demonstrate that a standard model of cometary nuclei explains well available
observational data: (1) A dust mantle with a thickness of ~1-2 m builds up on
the surface, where compact aggregates larger than tens of micrometers dominate;
(2) Large fluffy aggregates are embedded in chemically differentiated layers as
well as in the deepest part of the nucleus with primordial materials. We
conclude that the Deep Impact results do not need any peculiar view of a comet
nucleus.Comment: 11 pages, 1 figure, 1 table. ApJ letters, 673, L199-20
Trends and issues in clinical research on satisfaction and quality of life after mastectomy and breast reconstruction: a 5-year scoping review
Breast reconstruction (BR) aims to improve the satisfaction and quality of life (QOL) of breast cancer survivors. Clinical studies using patient-reported outcomes (PROs) can therefore provide relevant information to the patients and support decision-making. This scoping review was conducted to analyze recent trends in world regions, methods used, and factors investigated. The literature search was conducted in August 2022. Databases of PubMed, MEDLINE, and CINAHL were searched for relevant English-language studies published from 2017 to 2022. Studies involving women with breast cancer who underwent BR after mastectomy and investigated PROs after BR using BR-specific scales were included. Data on the country, publication year, study design, PRO measures (PROMs) used, time points of surveys, and research themes were collected. In total, 147 articles met the inclusion criteria. BREAST-Q was the most widely used, contributing to the increase in the number and diversification of studies in this area. Such research has been conducted mainly in North America and Europe and is still developing in Asia and other regions. The research themes involved a wide range of clinical and patient factors in addition to surgery, which could be influenced by research methods, time since surgery, and even cultural differences. Recent BR-specific PROMs have led to a worldwide development of research on factors that affect satisfaction and QOL after BR. PRO after BR may be influenced by local cultural and social features, and it would be necessary to accumulate data in each region to draw clinically useful conclusion
LATS1/2 kinases trigger self-renewal of cancer stem cells in aggressive oral cancer
Cancer stem cells (CSCs), which play important roles in tumor initiation and progression, are resistant to many types of therapies. However, the regulatory mechanisms underlying CSC-specific properties, including self-renewal, are poorly understood. Here, we found that LATS1/2, the core Hippo pathway-kinases, were highly expressed in the oral squamous cell carcinoma line SAS, which exhibits high capacity of CSCs, and that depletion of these kinases prevented SAS cells from forming spheres under serum-free conditions. Detailed examination of the expression and activation of LATS kinases and related proteins over a time course of sphere formation revealed that LATS1/2 were more highly expressed and markedly activated before initiation of self-renewal. Moreover, TAZ, SNAIL, CHK1/2, and Aurora-A were expressed in hierarchical, oscillating patterns during sphere formation, suggesting that the process consists of four sequential steps. Our results indicate that LATS1/2 trigger self-renewal of CSCs by regulating the Hippo pathway, the EMT, and cell division
Gastric Endocrine Cell Carcinoma with Long-Term Survival Developing Metachronous Remnant Cancer
A rare case of primary gastric endocrine cell carcinoma in a 79-year-old man is reported. Upper gastrointestinal endoscopy showed a large Bormann's type 2 tumour located in the middle of the stomach. On computed tomography, the gastric wall was thickened by the large tumour, and there were no distant metastases. Distal gastrectomy, lymph node dissection, and partial resection of the transverse colon were performed because the tumour involved the transverse mesocolon. The final pathological diagnosis was endocrine cell carcinoma, with tumour infiltration up to the subserous layer. Adjuvant chemotherapy was given, but metachronous remnant gastric cancer developed 2 years after surgery. Endoscopic submucosal dissection was performed for the early 0-IIc type gastric cancer, and the surgical margin was preserved. The patient has survived for 5 years after the primary surgery, remaining disease-free so far
Li diffusion in LiCoO probed by muon-spin spectroscopy
The diffusion coefficient of Li ions () in the battery
material LiCoO has been investigated by muon-spin relaxation
(SR). Based on the experiments in zero-field and weak
longitudinal-fields at temperatures up to 400 K, we determined the fluctuation
rate () of the fields on the muons due to their interaction with the
nuclear moments. Combined with susceptibility data and electrostatic potential
calculations, clear Li ion diffusion was detected above K. The
estimated from was in very good agreement with predictions
from first-principles calculations, and we present the SR technique as
an % novel and optimal probe to detect for materials containing
magnetic ions.Comment: 4 pages, 4 figures. accepted for publication in PR
Generation of third-harmonic spin oscillation from strong spin precession induced by terahertz magnetic near fields
The ability to drive a spin system to state far from the equilibrium is
indispensable for investigating spin structures of antiferromagnets and their
functional nonlinearities for spintronics. While optical methods have been
considered for spin excitation, terahertz (THz) pulses appear to be a more
convenient means of direct spin excitation without requiring coupling between
spins and orbitals or phonons. However, room-temperature responses are usually
limited to small deviations from the equilibrium state because of the
relatively weak THz magnetic fields in common approaches. Here, we studied the
magnetization dynamics in a HoFeO3 crystal at room temperature. A custom-made
spiral-shaped microstructure was used to locally generate a strong multicycle
THz magnetic near field perpendicular to the crystal surface; the maximum
magnetic field amplitude of about 2 T was achieved. The observed time-resolved
change in the Faraday ellipticity clearly showed second- and third-order
harmonics of the magnetization oscillation and an asymmetric oscillation
behaviour. Not only the ferromagnetic vector M but also the antiferromagnetic
vector L plays an important role in the nonlinear dynamics of spin systems far
from equilibrium
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