48 research outputs found

    Antibody formation for malignant tumor. II. Antigenicity of Ehrlich ascites tumor lipoprotein

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    A unique low density lipoprotein was obtained from the tumor transplanted with a cultured cell line of Ehrlich ascites tumor, JTC-ll cell. The tumor low density lipoprotein electrophoretically migrated as a single band, and the mobility was different from that of other organs. The chemical composition of lipid, cholesterol and phospholipids in tumor low density lipoprotein were characteristic. The flotation rate was Sf 5.9, and thus the molecular weight was estimated to be about 130 x 104. The inhibitory effect on tumor growth of the immune serum was most elevated at 25th day after the intraperitoneal administration of tumor low density lipoprotein. The main fraction effective for inhibition of tumor growth existed in &#947;-globulin.</p

    Estimated performance of the TRIUMF ultracold neutron source and electric dipole moment apparatus

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    Searches for the permanent electric dipole moment of the neutron (nEDM) provide strong constraints on theories beyond the Standard Model of particle physics. The TUCAN collaboration is constructing a source for ultracold neutrons (UCN) and an apparatus to search for the nEDM at TRIUMF, Vancouver, Canada. In this work, we estimate that the spallation-driven UCN source based on a superfluid helium converter will provide (1.38±0.02)×107(1.38\pm0.02) \times 10^7 polarized UCN at a density of 217±3217\pm3~UCN/cm3^3 to a room-temperature EDM experiment per fill. With (1.51±0.02)×106(1.51\pm0.02) \times 10^6 neutrons detected after the Ramsey cycle, the statistical sensitivity for an nEDM search per storage cycle will be (1.94±0.06)×1025e(1.94\pm0.06) \times 10^{-25}\,ecm (1σ\sigma). The goal sensitivity of 1027e10^{-27}\,ecm (1σ\sigma) can be reached within 280±16280\pm16 measurement days.Comment: Proceedings submitted to EPJ Web of Conferences for the Symposium on Symmetries in Subatomic Physics (SSP2022

    Involvement of the Precuneus/Posterior Cingulate Cortex Is Significant for the Development of Alzheimer’s Disease: A PET (THK5351, PiB) and Resting fMRI Study

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    Background: Imaging studies in Alzheimer’s disease (AD) have yet to answer the underlying questions concerning the relationship among tau retention, neuroinflammation, network disruption and cognitive decline. We compared the spatial retention patterns of 18F-THK5351 and resting state network (RSN) disruption in patients with early AD and healthy controls.Methods: We enrolled 23 11C-Pittsburgh compound B (PiB)-positive patients with early AD and 24 11C-PiB-negative participants as healthy controls. All participants underwent resting state functional MRI and 18F-THK5351 PET scans. We used scaled subprofile modeling/principal component analysis (SSM/PCA) to reduce the complexity of multivariate data and to identify patterns that exhibited the largest statistical effects (variances) in THK5351 concentration in AD and healthy controls.Findings: SSM/PCA identified a significant spatial THK5351 pattern composed by mainly three clusters including precuneus/posterior cingulate cortex (PCC), right and left dorsolateral prefrontal cortex (DLPFC) which accounted for 23.6% of the total subject voxel variance of the data and had 82.6% sensitivity and 79.1% specificity in discriminating AD from healthy controls. There was a significant relationship between the intensity of the 18F-THK5351 covariation pattern and cognitive scores in AD. The spatial patterns of 18F-THK5351 uptake showed significant similarity with intrinsic functional connectivity, especially in the PCC network. Seed-based connectivity analysis from the PCC showed significant decrease in connectivity over widespread brain regions in AD patients. An evaluation of an autopsied AD patient with Braak V showed that 18F-THK5351 retention corresponded to tau deposition, monoamine oxidase-B (MAO-B) and astrogliosis in the precuneus/PCC.Interpretation: We identified an AD-specific spatial pattern of 18F-THK5351 retention in the precuneus/PCC, an important connectivity hub region in the brain. Disruption of the functional connections of this important network hub may play an important role in developing dementia in AD

    The Precision nEDM Measurement with UltraCold Neutrons at TRIUMF

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    The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims at a precision neutron electric dipole moment (nEDM) measurement with an uncertainty of 1027ecm10^{-27}\,e\cdot\mathrm{cm}, which is an order-of-magnitude better than the current nEDM upper limit and enables us to test Supersymmetry. To achieve this precision, we are developing a new high-intensity ultracold neutron (UCN) source using super-thermal UCN production in superfluid helium (He-II) and a nEDM spectrometer. The current development status of them is reported in this article.Comment: Proceedings of the 24th International Spin Symposium (SPIN 2021), 18-22 October 2021, Matsue, Japa

    Discovery of New Hydrothermal Activity and Chemosynthetic Fauna on the Central Indian Ridge at 18°–20°S

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    Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called ‘scaly-foot’ gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean. Here we report two newly discovered hydrothermal vent fields, the Dodo and Solitaire fields, which are located in the Central Indian Ridge (CIR) segments 16 and 15, respectively. Chemosynthetic faunal communities at the Dodo field are emaciated in size and composition. In contrast, at the Solitaire field, we observed faunal communities that potentially contained almost all genera found at CIR hydrothermal environments to date, and even identified previously unreported taxa. Moreover, a new morphotype of ‘scaly-foot’ gastropod has been found at the Solitaire field. The newly discovered ‘scaly-foot’ gastropod has similar morphological and anatomical features to the previously reported type that inhabits the Kairei field, and both types of ‘scaly-foot’ gastropods genetically belong to the same species according to analyses of their COI gene and nuclear SSU rRNA gene sequences. However, the new morphotype completely lacks an iron-sulfide coating on the sclerites, which had been believed to be a novel feature restricted to ‘scaly-foot’ gastropods. Our new findings at the two newly discovered hydrothermal vent sites provide important insights into the biodiversity and biogeography of vent-endemic ecosystems in the Indian Ocean

    Studies on Low Density Lipoprotein in Tumor bearing MicePart Ⅱ. On steroid hormone in serum and liver low density lipoprotein

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    Low density lipoprotein in Ehrlich tumor bearing mice was studied on the cholesterol conversion to steroid hormone in serum and liver, and which were compared with those of normal mice by means of thin-layer chromatography and radioactivity. (3)H-cholesteryl ester was completely formed by 6 hours after the (3)H-cholesterol administration from peritoneal cavity. The most part of the cholesterol was esterified and incorporated into lipoproteins. The metabolic processes were studied in Ehrlich ascites carcinoma bearing mice. The cholesterol conversion to steroid hormone in tumor bearing mice L D L was elevated twice to four times than the normal

    Studies on Low Density Lipoprotein in Tumor bearing Mice Part I. On lipids in serum and organ low density lipoprotein

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    Low density lipoprotein in Ehrlich tumor bearing mice was studied on lipids in serum and Organs, and which were compared with those of normal mice by means of disc electrophoresis, biochemical analysis and thin-layer chromatography. The mobility of tumor bearing mice low density lipoprotein (L D L) in electrophoresis was smaller than that of normal mice L D L. The quantity of phospholipid to protein was decreased in tumor bearing mice L D L than normal. The ratio of phospholipid to cholesterol in serum and liver was decreased in tumor bearing mice than normal. On the structure of phospholipids, the content of lecithine in tumor bearingmice L D L reduced by half than normal

    Cryogenic design for a high intensity ultracold neutron source at TRIUMF

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    The TUCAN (TRIUMF Ultra-Cold Advanced Neutron) collaboration has been developing a source of high-intensity ultra-cold neutrons for use in a neutron electric dipole search. The source is composed of a spallation neutron source and a superfluid helium ultra-cold neutron converter, surrounded by a cold moderator. The temperature of the superfluid helium needs to be maintained at approximately 1.0 K to suppress up-scattering by phonons. The Kapitza conductance and the heat transport by the superfluid helium are key parameters which need to be well characterized. We have therefore investigated them in first experiments. Current efforts are directed at optimizing the design of the helium cryostat
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