290 research outputs found
The Intelligibility of Japanese Speakers of English to Native Speakers of English
This research was conducted to identify the most important English speech sounds which determine non-native English speakers\u27 intelligibility to native speakers of English. The researcher focused on variation of pronunciation by Japanese English speakers of differing levels of proficiency and examined the correlation between their pronunciation and intelligibility to native speakers. The results provided some keys to intelligible English speech and some implications for developing comprehensible speech in teaching English as a second language or English as a foreign language
Demographic Change, Intergenerational Altruism, and Fiscal Policy : A Political Economy Approach
Our study employs an OLG model under which political strengths of different generations (the working and retirees with and without children) determine the distribution of the fiscal burden between the generations, including the future generation. We investigate the relationship between the extent of intergenerational altruism, the political regime, and the intergenerational distribution of the fiscal burden. We show that if the working generation were to care more about the utility of the retirees (their parents), cooperation between the working and retirees with children would be possible, changing the political outcome. As a result, the tax burden of the working generation would decrease and its members would be better off. Lowering the voting age and having parents vote on behalf of their children would also result in the same shift, but for higher levels of intergenerational altruism and the working generation’s politicalPublic debt, public deficit, OLG models, intergenerational altruism, Demeny voting method
Polar surface engineering in ultra-thin MgO(111)/Ag(111) -- possibility of metal-insulator transition and magnetism
A recent report [Kiguchi {\it et al.}, Phys. Rev. B {\bf 68}, 115402 (2003)]
that the (111) surface of 5 MgO layers grown epitaxially on Ag(111) becomes
metallic to reduce the electric dipole moment raises a question of what will
happen when we have fewer MgO layers. Here we have revealed, first
experimentally with electron energy-loss spectroscopy, that MgO(111) remains
metallic even when one-layer thick, and theoretically with the density
functional theory that the metallization should depend on the nature of the
substrate. We further show, with a spin-density functional calculation, that a
ferromagnetic instability may be expected for thicker films.Comment: 5 pages, 7 figure
Metal-Induced Gap States at Well Defined Alkali-Halide/Metal Interfaces
In order to search for states specific to insulator/metal interfaces, we have
studied epitaxially grown interfaces with element-selective near edge X-ray
absorption fine structure (NEXAFS). An extra peak is observed below the bulk
edge onset for LiCl films on Cu and Ag substrates. The nature of chemical bonds
as probed by X-ray photoemission spectroscopy and Auger electron spectroscopy
remains unchanged, so we regard this as evidence for metal-induced gap
states(MIGS) formed by the proximity to a metal, rather than local bonds at the
interface. The dependence on the film thickness shows that the MIGS are as thin
as one monolayer. An ab initio electronic structure calculation supports the
existence of the MIGS that are strongly localized at the interface.Comment: 4 pages, 5 figures, to be published in Phys. Rev. Let
Leiomyosarcoma of the sigmoid colon with multiple liver metastases and gastric cancer: a case report
BACKGROUND: Leiomyosarcoma (LMS) of the gastrointestinal tract is an extremely rare high-grade neoplasm with poor prognosis. For advanced LMS with distant metastasis, the decision as to the choice of the most appropriate therapeutic strategy, including chemotherapy and surgery, is difficult. Here, we present an unusual case of LMS of the sigmoid colon with liver metastases and gastric cancer. The survival of this patient was prolonged by a combined modality therapy involving chemotherapy and surgery. CASE PRESENTATION: A 66-year-old woman who had been diagnosed with advanced gastric cancer and multiple liver metastases was referred to our hospital. The initial treatment with docetaxel and S-1 considerably reduced both the gastric cancer and liver tumors; consequently we performed surgical resection. Pathological examination revealed that no viable tumor cells remained in the stomach and chemotherapy resulted in complete remission of the gastric cancer. The liver tumors were immunohistochemically diagnosed as LMS. A tumor of the sigmoid colon was subsequently discovered and the liver tumors were found to have recurred. The surgically resected sigmoid colon and liver tumors were all immunohistochemically diagnosed as LMS. These findings indicated that the multiple liver metastases arose from the LMS in the sigmoid colon, and that they were accompanied by advanced gastric cancer. We performed another surgical resection and administered chemotherapy to treat the recurring liver metastases. The patient survived for 4 years and 10 months after initial presentation at our hospital. CONCLUSION: Colonic LMS is rare and its joint occurrence with gastric cancer is extremely unusual. Although LMS is a high-grade neoplasm, a multimodal therapeutic approach can increase patient survival time even when multiple liver metastases are present
Ultrafiltration attenuates cardiopulmonary bypass–induced acute lung injury in a canine model of single-lung transplantation
ObjectiveThe purpose of this study was to investigate the effects of cardiopulmonary bypass and ultrafiltration on graft function in a canine single-lung transplantation model.MethodsFifteen left single-lung transplantations were done in weight-mismatched canine pairs. The animals were divided into 3 groups: group 1, in which transplantation was done without cardiopulmonary bypass; group 2, in which transplantation was done with cardiopulmonary bypass and in which the cardiopulmonary bypass flow was decreased slowly with controlled pulmonary artery pressure; and group 3, in which transplantation was done with cardiopulmonary bypass and ultrafiltration. Hemodynamic parameters and lung function were monitored for 6 hours after reperfusion. The grafts were harvested for histologic studies, myeloperoxidase assay, and real-time quantitive reverse transcription–polymerase chain reaction of mRNA encoding interleukin 6.ResultsThe hemodynamic parameters were similar among the 3 groups. In group 1 Pao2 and alveolar to arterial gradient for O2 levels were excellent throughout the 6-hour observation period, but in group 2 they progressively deteriorated. However, ultrafiltration significantly (P = .02) improved the Pao2 level in group 3. On histology, interstitial edema and polynuclear cell infiltration were most marked in group 2 and significantly worse than in groups 1 and 3. Myeloperoxidase assay and real-time quantitative reverse transcription–polymerase chain reaction showed increased myeloperoxidase activity and interleukin 6 gene expression in group 2 grafts compared with group 1 grafts. Myeloperoxidase activity and interleukin 6 gene expression were suppressed with ultrafiltration.ConclusionsCardiopulmonary bypass had negative effects on the graft, but ultrafiltration attenuated acute lung dysfunction by reducing the inflammatory response
Applications of Carbon Nanotubes in Bone Regenerative Medicine
Scaffolds are essential for bone regeneration due to their ability to maintain a sustained release of growth factors and to provide a place where cells that form new bone can enter and proliferate. In recent years, scaffolds made of various materials have been developed and evaluated. Functionally effective scaffolds require excellent cell affinity, chemical properties, mechanical properties, and safety. Carbon nanotubes (CNTs) are fibrous nanoparticles with a nano-size diameter and have excellent strength and chemical stability. In the industrial field, they are used as fillers to improve the performance of materials. Because of their excellent physicochemical properties, CNTs are studied for their promising clinical applications as biomaterials. In this review article, we focused on the results of our research on CNT scaffolds for bone regeneration, introduced the promising properties of scaffolds for bone regeneration, and described the potential of CNT scaffolds.ArticleNANOMATERIALS. 10(4):659 (2020)journal articl
Physico-Chemical, In Vitro, and In Vivo Evaluation of a 3D Unidirectional Porous Hydroxyapatite Scaffold for Bone Regeneration
The unidirectional porous hydroxyapatite HAp (UDPHAp) is a scaffold with continuous communicated pore structure in the axial direction. We evaluated and compared the ability of the UDPHAp as a three-dimensional (3D) bone tissue engineering scaffold to the interconnected calcium porous HAp ceramic (IP-CHA). To achieve this, we evaluated in vitro the compressive strength, controlled rhBMP-2 release behavior, adherent cell morphology, cell adhesion manner, and cell attachment of UDPHAp. As a further in vivo experiment, UDPHAp and IP-CHA with rhBMP-2 were transplanted into mouse calvarial defects to evaluate their bone-forming ability. The Results demonstrated that the maximum compressive strengths of the UDPHAp was 7.89 +/- 1.23 MPa and higher than that of IP-CHA (1.92 +/- 0.53 MPa) (p = 0.0039). However, the breaking energies were similar (8.99 +/- 2.72 vs. 13.95 +/- 5.69 mJ, p = 0.055). The UDPHAp released rhBMP-2 more gradually in vivo. Cells on the UDPHAp adhered tightly to the surface, which had grown deeply into the scaffolds. A significant increase in cell number on the UDPHAp was observed compared to the IP-CHA on day 8 (102,479 +/- 34,391 vs. 32,372 +/- 29,061 estimated cells per scaffold, p = 0.0495). In a mouse calvarial defect model, the percentages of new bone area (mature bone + trabecular bone) in the 2x field were 2.514% +/- 1.224% for the IP-CHA group and 7.045% +/- 2.055% for the UDPHAp group, and the percentage was significantly higher in the UDPHAp group (p = 0.0209). While maintaining the same strength as the IP-CHA, the UDPHAp with 84% porosity showed a high cell number, high cell invasiveness, and excellent bone formation. We believe the UDPHAp is an excellent material that can be applied to bone regenerative medicine.ArticleMATERIALS. 10(1):33 (2017)journal articl
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