99 research outputs found

    Separation and recovery of carbon dioxide by a membrane flash process utilizing waste thermal energy

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    AbstractThe membrane flash process utilizing waste thermal energy was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The operating conditions of a membrane flash at high temperature were studied. The DEA concentration and the flashing pressure had optimum values to improve the performance and reduce the energy consumption for CO2 recovery. The petroleum refinery process and iron manufacturing process were proposed for candidate processes that actually had waste energy sources. Energy consumption and costs for CO2 recovery in the membrane flash and chemical absorption were estimated by custom-made program and discussed under the same conditions. The membrane flash was suitable for the CO2 emission sources that had high CO2 concentration independently of the plant scale. The chemical absorption was suitable for large-scale sources, even if the CO2 concentration was low

    Effects of Microgravity on Human Physiology

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    The effects of microgravity conditions on neurovestibular, cardiovascular, musculoskeletal, bone metabolic, and hemato-immunological systems are described. We discuss “space motion sickness,” sensorimotor coordination disorders, cardiovascular deconditioning, muscular atrophy, bone loss, and anemia/immunodeficiency, including their causes and mechanisms. In addition to the previously described deconditioning, new problems related to microgravity, spaceflight-associated neuro-ocular syndrome (SANS), and structural changes of the brain by magnetic resonance imaging (MRI) are also explained. Our proposed countermeasure, artificial gravity produced by a short-arm centrifuge with ergometric exercise, is also described in detail, and we confirmed this system to be effective in preventing the abovementioned deconditioning caused by microgravity exposure

    鏡視下足関節固定術で使用される中空海綿骨螺子による圧着圧の比較

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    Background: When performing arthroscopic ankle arthrodesis for end-stage ankle arthritis, internal fixation is performed using bone screws after appropriate preparation. However, optimal characteristics of bone screws have not been examined in terms of pressure force. Objective comparisons of bone-screw performance may provide information on procedures for arthroscopic ankle arthrodesis. The study objectives were to determine whether it was possible to measure compressive force changes using the newly developed device and to infer all screw characteristics from measurement results when used in actual surgeries. In addition, we performed experiments on cadavers to verify whether the experimental results could be applied to the joints of living subjects. Methods: Three types of screws (S1, S2, and S3) were inserted into the unique measurement device, and the changes in pressure were measured for each 45° turn. Changes in pressure and maximum pressure force were recorded after the application of the screws. After reaching the maximum pressure in the simulated bone, further screw rotations were accompanied by a gradual pressure decrease to 0 MPa. We also measured pressure changes in a similar manner by inserting a miniature pressure sensor into the talocrural joints of cadavers. Results: The mean maximum pressure ± standard deviation for S1, S2, and S3 were 0.832 ± 0.164 MPa, 0.434 ± 0.116 MPa, and 0.414 ± 0.127 MPa, respectively. Pressure slopes to the maximum did not significantly differ between the screws in the simulated bone, and a subsequent pressure decrease to 0 MPa was significantly more rapid for S1 than for S2 and S3. Although pressure failure after the overtightening of screws was only observed in the simulated bone, patterns of pressure vs. rotation angle were similar in simulated and cadaveric bones. The pressure profile characteristics of three different screw types were determined. Conclusions: We were able to measure the compressive force changes using the newly developed device when the screws were inserted. On the basis of the measurement results, we were able to infer the characteristics of all screws when used in actual surgery.博士(医学)・乙第1403号・平成29年6月28日Copyright © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    Baroreflex control of muscle sympathetic nerve activity after 120 days of 6°head-down bed rest

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    of muscle sympathetic nerve activity after 120 days of 6°head-down bed rest. Am. J. Physiol. Regulatory Integrative Comp. Physiol. 278: R445-R452, 2000.-To examine how long-lasting microgravity simulated by 6°head-down bed rest (HDBR) induces changes in the baroreflex control of muscle sympathetic nerve activity (MSNA) at rest and changes in responses of MSNA to orthostasis, six healthy male volunteers (range 26-42 yr) participated in Valsalva maneuver and head-up tilt (HUT) tests before and after 120 days of HDBR. MSNA was measured directly using a microneurographic technique. After long-term HDBR, resting supine MSNA and heart rate were augmented. The baroreflex slopes for MSNA during Valsalva maneuver (in supine position) and during 60°HUT test, determined by least-squares linear regression analysis, were significantly steeper after than before HDBR, whereas the baroreflex slopes for R-R interval were significantly flatter after HDBR. The increase in MSNA from supine to 60°HUT was not different between before and after HDBR, but mean blood pressure decreased in 60°HUT after HDBR. In conclusion, the baroreflex control of MSNA was augmented, whereas the same reflex control of R-R interval was attenuated after 120 days of HDBR. microneurography; orthostatic hypotensio

    miR-378a-3p modulates tamoxifen sensitivity in breast cancer MCF-7 cells through targeting GOLT1A

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    Breast cancer is a hormone-dependent cancer and usually treated with endocrine therapy using aromatase inhibitors or anti-estrogens such as tamoxifen. A majority of breast cancer, however, will often fail to respond to endocrine therapy. In the present study, we explored miRNAs associated with endocrine therapy resistance in breast cancer. High-throughput miRNA sequencing was performed using RNAs prepared from breast cancer MCF-7 cells and their derivative clones as endocrine therapy resistant cell models, including tamoxifen-resistant (TamR) and long-term estrogen-deprived (LTED) MCF-7 cells. Notably, miR-21 was the most abundantly expressed miRNA in MCF-7 cells and overexpressed in TamR and LTED cells. We found that miR-378a-3p expression was downregulated in TamR and LTED cells as well as in clinical breast cancer tissues. Additionally, lower expression levels of miR-378a-3p were associated with poor prognosis for tamoxifen-treated patients with breast cancer. GOLT1A was selected as one of the miR-378a-3p candidate target genes by in silico analysis. GOLT1A was overexpressed in breast cancer specimens and GOLT1A-specific siRNAs inhibited the growth of TamR cells. Low GOLT1A levels were correlated with better survival in patients with breast cancer. These results suggest that miR-378a-3p-dependent GOLT1A expression contributes to the mechanisms underlying breast cancer endocrine resistance

    TIGIT/CD155 axis mediates resistance to immunotherapy in patients with melanoma with the inflamed tumor microenvironment

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    Background Patients with cancer benefit from treatment with immune checkpoint inhibitors (ICIs), and those with an inflamed tumor microenvironment (TME) and/or high tumor mutation burden (TMB), particularly, tend to respond to ICIs; however, some patients fail, whereas others acquire resistance after initial response despite the inflamed TME and/or high TMB. We assessed the detailed biological mechanisms of resistance to ICIs such as programmed death 1 and/or cytotoxic T-lymphocyte-associated protein 4 blockade therapies using clinical samples. Methods We established four pairs of autologous tumor cell lines and tumor-infiltrating lymphocytes (TILs) from patients with melanoma treated with ICIs. These tumor cell lines and TILs were subjected to comprehensive analyses and in vitro functional assays. We assessed tumor volume and TILs in vivo mouse models to validate identified mechanism. Furthermore, we analyzed additional clinical samples from another large melanoma cohort. Results Two patients were super-responders, and the others acquired resistance: the first patient had a non-inflamed TME and acquired resistance due to the loss of the beta-2 microglobulin gene, and the other acquired resistance despite having inflamed TME and extremely high TMB which are reportedly predictive biomarkers. Tumor cell line and paired TIL analyses showed high CD155, TIGIT ligand, and TIGIT expression in the tumor cell line and tumor-infiltrating T cells, respectively. TIGIT blockade or CD155-deletion activated T cells in a functional assay using an autologous cell line and paired TILs from this patient. CD155 expression increased in surviving tumor cells after coculturing with TILs from a responder, which suppressed TIGIT+ T-cell activation. Consistently, TIGIT blockade or CD155-deletion could aid in overcoming resistance to ICIs in vivo mouse models. In clinical samples, CD155 was related to resistance to ICIs in patients with melanoma with an inflamed TME, including both primary and acquired resistance. Conclusions The TIGIT/CD155 axis mediates resistance to ICIs in patients with melanoma with an inflamed TME, promoting the development of TIGIT blockade therapies in such patients with cancer

    Control of Cortical Axon Elongation by a GABA-Driven Ca<sup style="margin: 0px; padding: 0px; border: 0px; outline-style: none; font-weight: inherit; font-style: inherit; font-size: 0.85em; font-family: inherit; line-height: 0; text-align: inherit; vertical-align: super;">2+/Calmodulin-Dependent Protein Kinase Cascade</sup>

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    Ca(2+) signaling plays important roles during both axonal and dendritic growth. Yet, whether and how Ca(2+) rises may trigger and contribute to the development of long range cortical connections remains largely unknown. Here we demonstrate that two separate limbs of CaMK kinase (CaMKK) - CaMKI cascades, CaMKK-CaMKIα and CaMKK-CaMKIγ, critically coordinate axonal and dendritic morphogenesis of cortical neurons, respectively. The axon-specific morphological phenotype required a diffuse cytoplasmic localization and a strikingly α-isoform-specific kinase activity of CaMKI. Unexpectedly, treatment with muscimol, a GABA(A) receptor agonist, selectively stimulated elongation of axons but not of dendrites, and the CaMKK-CaMKIα cascade critically mediated this axonogenic effect. Consistent with these findings, during early brain development, in vivo knockdown of CaMKIα significantly impaired the terminal axonal extension, and thereby perturbed the refinement of the interhemispheric callosal projections into the contralateral cortices. Our findings thus indicate a novel role for the GABA-driven CaMKK-CaMKIα cascade as a mechanism critical for accurate cortical axon pathfinding, an essential process which may contribute to fine-tuning the formation of interhemispheric connectivity during the perinatal development of the central nervous system

    Growth, Sexual Dimorphism, and Geographical Variation of Skull Dimensions of the Brown Bear Ursus arctos in Hokkaido

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    The growth, sexual dimorphism, and geographical variation in skulls of 596 brown bears (Ursus arctos) hunted in Hokkaido, Japan from 1971 to 1986 were investigated. Most cranial traits continued to increase after the age of sexual maturity, and in particular skulls became progressively wider with age. Skulls of males, even those of cubs and yearlings, were larger than those of females, and the difference became significant after two years of age. Skull dimensions tended to increase from south to north, in Hokkaido, and bears from the north-eastern region possessed higher brain cases and longer mandibles relative to skull length and width, than those in the southern region
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