642 research outputs found

    Growth of Adsorbed Additive Layer for Further Friction Reduction

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    Special Issue:6th European Conference on Tribology (ECOTRIB 2017)Boundary lubrication is one of the most interesting topics in the field of tribology, and a lot of studies have been conducted from the past for understanding the behaviour of boundary lubrication films. General boundary lubrication films are formed by the adsorption of additives mixed into lubricant, and then the tribological performances are drastically improved in many cases. However, there is still room for discussion on the “actual” behaviour of adsorbed additive layer in the tribological condition, that is, under high pressure and/or with external forces. This paper showed the “growing” behaviour of an adsorbed additive layer onto metal surface due to high pressure by means of neutron reflectometry in conjunction with the result obtained through cross‐sectional imaging by frequency‐modulation atomic force microscopy. In addition, the nanotribological study using atomic force microscopy with a colloidal probe showed that the coefficient of friction in the pre‐scratched area was lower than that in the non‐scratched area and that the reduction ratio for lubricant with additive was higher than that for lubricant without additive. This result indicates that growth of the adsorbed additive layer contributed more greatly to a reduction in the coefficient of friction

    Supernova Nucleosynthesis and Extremely Metal-Poor Stars

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    We investigate hydrodynamical and nucleosynthetic properties of the jet-induced explosion of a population III 40M40M_\odot star and compare the abundance patterns of the yields with those of the metal-poor stars. We conclude that (1) the ejection of Fe-peak products and the fallback of unprocessed materials can account for the abundance patterns of the extremely metal-poor (EMP) stars and that (2) the jet-induced explosion with different energy deposition rates can explain the diversity of the abundance patterns of the metal-poor stars. Furthermore, the abundance distribution after the explosion and the angular dependence of the yield are shown for the models with high and low energy deposition rates E˙dep=120×1051ergss1\dot{E}_{\rm dep}=120\times10^{51} {\rm ergs s^{-1}} and 1.5×1051ergss11.5\times10^{51} {\rm ergs s^{-1}}. We also find that the peculiar abundance pattern of a Si-deficient metal-poor star HE 1424--0241 can be reproduced by the angle-delimited yield for θ=3035\theta=30^\circ-35^\circ of the model with E˙dep=120×1051ergss1\dot{E}_{\rm dep}=120\times10^{51} {\rm ergs s^{-1}}.Comment: 6 pages, 3 figures. To appear in "ORIGIN OF MATTER AND EVOLUTION OF GALAXIES: From the Dawn of Universe to the Formation of Solar System", AIP Conf. Proc. 1016 (December 2007, Sapporo), eds. T. Suda, T. Nozawa, et al. (Melville: AIP

    Detection of the Gravitational Lens Magnifying a Type Ia Supernova

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    Objects of known brightness, like Type Ia supernovae (SNIa), can be used to measure distances. If a massive object warps spacetime to form multiple images of a background SNIa, a direct test of cosmic expansion is also possible. However, these lensing events must first be distinguished from other rare phenomena. Recently, a supernova was found to shine much brighter than normal for its distance, which resulted in a debate: was it a new type of superluminous supernova or a normal SNIa magnified by a hidden gravitational lens? Here we report that a spectrum obtained after the supernova faded away shows the presence of a foreground galaxy--the first found to strongly magnify a SNIa. We discuss how more lensed SNIa may be found than previously predicted.Comment: 32 pages, 10 figures. Accepted for publication in Scienc

    Roles of FoxP3-positive Regulatory T Cells in Lymphoid Follicle Formation Associated with Lung Squamous Cell Carcinoma

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    Background:We previously reported that lymphoid follicle formation by tumor infiltrating lymphocytes(TILs)is a negative predictor of prognosis in patients with lung squamous cell carcinoma(SCC)following surgery. However, the roles of FoxP3⁺/CD4⁺/CD25⁺-regulatory T cells(Tregs)in formation of lymphoid follicles as well as survival remain unclear.Methods:Specimens obtained from patients during resection of lung SCC were examined for lymphoid follicle formation and subjected to immunohistochemistry analysis for the presence of TILs.Results:The appearance of Tregs was correlated with lymphoid follicle formation(p=0.001). Univariate analysis also showed that Tregs tended to be correlated with overall survival(p=0.097), whereas multivariate analysis revealed that lymphoid follicle formation(p=0.042)and pleural invasion(p=0.031)were independent prognostic factors related to overall survival, while the appearance of Tregs was not.Conclusion:Treg appearance was correlated with lymphoid follicle formation. That lymphoid follicle formation, rather than appearance of Tregs, is a predictor of patients survival following surgery for lung SCC

    A Case of an Invasive Lobular Carcinoma with Extracellular Mucin: Radio-Pathological Correlation

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    A case of 77-year-old female with an invasive lobular carcinoma with extracellular mucin is presented. She felt palpable mass in her left breast. Then, she came to our hospital for further examination. Mammography of right in full view revealed architectural distortion in left upper portion. And ultrasonography demonstrated low-echoic mass about 2 cm in diameter and invasion of the fat tissue was observed. Hence, malignancy was suspected and magnetic resonance imaging (MRI) was performed. MRI findings showed irregular shaped and margined mass with small T2-high-signal intensity. These findings suggested invasive carcinoma with mucin. Because the cancer lesion was not large, partial mastectomy was performed. Interestingly, pathological diagnosis was invasive lobular carcinoma with extracellular mucin. Extracellular mucinous lesion was concordant with small T2-high-signal intensity. This type of carcinoma was previously reported only in three cases, and rare but important, because the treatment and prognosis might change by histological subtypes. We suggest one of the MRI special features of our case is not only irregular shaped and margined mass but also small T2-high-signal intensity. These MR findings might be one of the valuable findings for the diagnosis and differentiation between this type of carcinoma from other tumors

    神経芽腫におけるPD-L1発現と腫瘍組織浸潤リンパ球の潜在的役割について

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    Purpose: The programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway has garnered much attention for its roles in clinical oncology. The aim of this study was to examine the clinical impact of the PD-L1 expression and tumor-infiltrating lymphocytes (TILs) on neuroblastoma. Methods: We evaluated the PD-L1 expression and TIL status in 31 patients with neuroblastoma who underwent a biopsy or resection by an immunohistochemical analysis. Furthermore, we performed the serial analysis of the PD-L1 status before and after chemotherapy in 15 patients. Results: Among the 31 cases, 11 (35%) showed a positive PD-L1 expression. The survival analysis showed a trend toward an association between PD-L1 positivity and a decreased overall survival. PD-L1 positivity tended to be associated with higher levels of tumor markers. In the serial analysis of the PD-L1 status, positivity was noted in 8 of 15 patients before chemotherapy and 6 after chemotherapy. Notably, all four patients with a positive PD-L1 status both before and after chemotherapy had recurrence, and 3 of them died during the follow-up period. Conclusion: Our findings suggest that the PD-L1 tumor expression might be a good biomarker for the treatment of neuroblastoma patients, especially for advanced neuroblastoma.博士(医学)・乙第1458号・令和2年6月30日© Springer-Verlag GmbH Germany, part of Springer Nature 2020This is a post-peer-review, pre-copyedit version of an article published in Pediatric surgery international. The final authenticated version is available online at: http://doi.org/10.1007/s00383-019-04616-9

    The Therapeutic Potential of Human Umbilical Cord Blood Transplantation for Neonatal Hypoxic-Ischemic Brain Injury and Ischemic Stroke

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    Human umbilical cord blood (HUCB) cells are rich source of immature stem cells, which have the potential to repair lost tissue. Intractable central nervous system (CNS) disorders are important targets for regenerative medicine, and the application of HUCB cells is being investigated in animal models of CNS disorders. Transplantation of HUCB has induced functional improvements in these animal models due to multiple therapeutic effects including neuroprotection, anti-inflammation, angiogenesis, and neurogenesis. HUCB cells are easily available and safer than other stem cells used in transplantation therapy. In this review, we focus on HUCB transplantation as an encouraging therapeutic approach for animal models of neonatal hypoxic-ischemic brain injury and ischemic stroke

    Antitumor activity of α-pinene in T-cell tumors

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    T-cell acute leukemia and lymphoma have a poor prognosis. Although new therapeu-tic agents have been developed, their therapeutic effects are suboptimal. α- Pinene, a monoterpene compound, has an antitumor effect on solid tumors; however, few comprehensive investigations have been conducted on its impact on hematologic ma-lignancies. This report provides a comprehensive analysis of the potential benefits of using α- pinene as an antitumor agent for the treatment of T-cell tumors. We found that α- pinene inhibited the proliferation of hematologic malignancies, especially in T- cell tumor cell lines EL-4 and Molt-4, induced mitochondrial dysfunction and re-active oxygen species accumulation, and inhibited NF-κB p65 translocation into the nucleus, leading to robust apoptosis in EL-4 cells. Collectively, these findings suggest that α- pinene has potential as a therapeutic agent for T-cell malignancies, and further investigation is warranted
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