190 research outputs found

    Diffusion of Water in Bentonite

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    Because of the low permeability and the high sorption coefficient, compacted sodium bentonite has been proposed as an effective backfill material in the repository of high-level radioactive waste. The only possible mechanism of nuclide transport in bentonite must be the diffusion. The diffusivity has been considered to have a close relationship with the retardation factor and the self-diffusivity of water. Then, we performed the experiments to determine the self-diffusivity of water in bentonite by using tritiated water as a tracer. The obtained self-diffusivity can be written as Da= (3.4 ± 0.2) × 10-6 [cm²/s] under the condition of temperature T= 25°C and compacted density of bentonite ρ= 2.7 [g/cm³]. It was revealed quantitatively that the self-diffusivity of water in bentonite is much smaller than that of free water (2.13 × 10-5 [cm²/s] at T= 25°C). Also discussed is the analysis of experimental results on the basis of a new solution derived for the diffusion in one dimensional finite zone

    Identification of prothymosin-α1, the necrosis–apoptosis switch molecule in cortical neuronal cultures

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    We initially identified a nuclear protein, prothymosin-α1 (ProTα), as a key protein inhibiting necrosis by subjecting conditioned media from serum-free cultures of cortical neurons to a few chromatography steps. ProTα inhibited necrosis of cultured neurons by preventing rapid loss of cellular adenosine triphosphate levels by reversing the decreased membrane localization of glucose transporters but caused apoptosis through up-regulation of proapoptotic Bcl2-family proteins. The apoptosis caused by ProTα was further inhibited by growth factors, including brain-derived neurotrophic factor. The ProTα-induced cell death mode switch from necrosis to apoptosis was also reproduced in experimental ischemia-reperfusion culture experiments, although the apoptosis level was markedly reduced, possibly because of the presence of growth factors in the reperfused serum. Knock down of PKCβII expression prevented this cell death mode switch. Collectively, these results suggest that ProTα is an extracellular signal protein that acts as a cell death mode switch and could be a promising candidate for preventing brain strokes with the help of known apoptosis inhibitors

    Competition of perpendicular magnetic anisotropy and exchange magnetic anisotropy in a Pt/Co/α-Cr₂O₃(0001) thin film

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    We investigated perpendicular magnetic anisotropy and exchange magnetic anisotropy in a Pt/Co/α-Cr₂O₃(0001) thin film grown on an α-Al₂O₃(0001) substrate. The film exhibits perpendicular magnetic anisotropy below a Co thickness of 1.2 nm at room temperature. Independent of the magnetic easy direction of the Co layer, the perpendicular exchange bias (PEB) appears in a direction perpendicular to the film below 80 K. The maximum unidirectional magnetic anisotropy energy estimated from the exchange bias field is 0.33 erg/cm², which is higher than the reported PEB strength. The perpendicular exchange bias is accompanied by the in-plane remanent magnetization and an increase in the in-plane coercivity. We speculate that the increases in the in-plane remanent magnetization and the in-plane coercivity are caused by the spin canting of Cr³⁺ in the α-Cr₂O₃(0001) layer.Yu Shiratsuchia, Hayato Noutomi, Hiroto Oikawa, Toshiaki Fujita, and Ryoichi Nakatani, Journal of Applied Physics 109, 07C101 (2011); https://doi.org/10.1063/1.3535555

    MicroRNA, hsa-miR-200c, is an independent prognostic factor in pancreatic cancer and its upregulation inhibits pancreatic cancer invasion but increases cell proliferation

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    <p>Abstract</p> <p>Background</p> <p>Recently, the microRNA-200 family was reported to affect cancer biology by regulating epithelial to mesenchymal transition (EMT). Especially, the expression of <it>miR-200c </it>has been shown to be associated with upregulating the expression of <it>E-cadherin</it>, a gene known to be involved in pancreatic cancer behavior. However, the significance of <it>miR-200c </it>in pancreatic cancer is unknown.</p> <p>Methods</p> <p>In the present study, we investigated the relationship between <it>E-cadherin </it>and <it>miR-200c </it>expression in a panel of 14 pancreatic cancer cell lines and in macro-dissected formalin-fixed paraffin-embedded (FFPE) tissue samples obtained from 99 patients who underwent pancreatectomy for pancreatic cancer. We also investigated the effects of <it>miR-200c </it>on the proliferation and invasion of pancreatic cancer cells.</p> <p>Results</p> <p>We found that patients with high levels of <it>miR-200c </it>expression had significantly better survival rates than those with low levels of <it>miR-200c </it>expression. We also found a remarkably strong correlation between the levels of <it>miR-200c </it>and <it>E-cadherin </it>expression.</p> <p>Conclusions</p> <p>These data indicate that <it>miR-200c </it>may play a role in the pancreatic cancer biology and may be a novel marker for the prognosis of pancreatic cancer.</p

    Detection and in situ switching of unreversed interfacial antiferromagnetic spins in a perpendicular-exchange-biased system

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    By using the perpendicular-exchange-biased Pt/Co/α-Cr₂O₃ system, we provide experimental evidence that the unreversed uncompensated Cr spins exist at the Co/α-Cr₂O₃ interface. The unreversed uncompensated Cr spin manifests itself in both the vertical shift of an element-specific magnetization curve and the relative peak intensity of soft-x-ray magnetic circular dichroism spectrum. We also demonstrate an in situ switching of the interfacial Cr spins and correspondingly a reversal of the exchange bias without interfacial atomic diffusion. Such switching shows the direct relationship between the interfacial antiferromagnetic spins and origin of the exchange bias. The demonstrated switching of exchange bias would likely offer a new design of advanced spintronics devices, using the perpendicular-exchange-biased system, with low power consumption and ultrafast operation.Y.Shiratsuchi, H.Noutomi, H.Oikawa, et al. Detection and in situ switching of unreversed interfacial antiferromagnetic spins in a perpendicular-exchange-biased system. Physical Review Letters 109, 077202 (2012); https://doi.org/10.1103/PhysRevLett.109.077202

    Análise macroscópica e radiográfica de dentes decíduos com hiperbilirrubinemia de crianças com doenças hepáticas crônicas e transplante hepático

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    Aim: is to identify, through macroscopic and radiographic analysis, structural changes in dental tissues affected by hyperbilirubinemia, usually seen from the clinical sign of icterus and causes the development of intrinsic greenish pigments in dental structure. Materials and Methods: The sample consisted of 31 primary teeth divided into a control group (n=7) and an experimental group (n=24). Macroscopic analyzes were performed using standardized individual photographs and radiographic ones obtained by image acquisition at 9 mA, 70 kVp, 8cm distance, 0.4 seconds exposure and with XDR Sensor®. The images were converted by XDR Brasil 3.1.6 software and standardized by GIMP 2.10.22 software. The Histogram’s simple mean data were analyzed by T-Student and Mann-Whitney tests (p&lt;0.05). Results: showed intensity of pigmentation in the cervical region of the root, with a statistically significant difference in the root portion between the experimental and control groups (p=0.043. In the analysis of radiographic density of the root structure of the experimental group, there was a statistically significant difference (p= 0.016) between the cervical and apical thirds. Discussion: The data showed that teeth pigmented by hyperbilirubinemia do not have changes in mineral density in the coronary thirds. Conclusion: Greenish pigments teeth have differences in radiographic density only in the root structure.Objetivo: identificar mediante análise macroscópica e radiográfica as alterações estruturais em tecidos dentários afetados pela hiperbilirrubinemia, normalmente constatada a partir do sinal clínico de icterícia e provoca o desenvolvimento de pigmentos intrínsecos esverdeados nas estruturas dentárias. Materiais e Métodos: a amostra foi composta por 31 dentes decíduos dividida em grupo controle (n= 7) e grupo experimental (n= 24). As análises macroscópicas foram efetuadas por meio de fotografias individuais padronizadas e as radiográficas obtidas com aquisições de imagem a 9 mA, 70 kVp, distância de 8cm, exposição 0,4 segundos e com XDR Sensor®. As imagens foram convertidas pelo software XDR Brasil 3.1.6 e padronizadas pelo programa GIMP 2.10.22. Os dados da média simples do histograma foram analisados pelo teste T-Student e Mann-Whitney (p&lt;0,05). Resultados: demonstraram a maior intensidade de pigmentação em região cervical da raiz, com diferença de densidade radiográfica estaticamente significante na porção radicular entre os grupos experimental e controle (p=0,043). Na análise da densidade radiográfica da estrutura radicular do grupo experimental houve diferença estaticamente significante (p=0,016) entre os terços cervical e apical. Discussão: Os dados evidenciaram que dentes pigmentados pela hiperbilirrubinemia não possuem alterações na densidade mineral nos terços coronários. Conclusão: Dentes com pigmentação esverdeada bilirrubina possuem diferenças na densidade radiográfica somente na região radicular

    Preoperative Butyrylcholinesterase Level as an Independent Predictor of Overall Survival in Clear Cell Renal Cell Carcinoma Patients Treated with Nephrectomy

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    The prognostic factors for the overall survival (OS) of clear cell renal cell carcinoma (ccRCC) patients treated with nephrectomy are not well defined. In the present study, we investigated the prognostic significance of preoperative butyrylcholinesterase (BChE) levels in 400 ccRCC patients undergoing radical or partial nephrectomy from 1992 to 2013 at our institution. Univariate and multivariate analyses were performed to determine the clinical factors associated with OS. Among the enrolled patients, 302 were diagnosed with organ-confined disease only (T1-2N0M0), 16 with lymph node metastases, and 56 with distant metastases. The median preoperative BChE level was 250 U/L (normal range, 168–470 U/L), and median follow-up period was 36 months. The 3-year OS rate in patients with preoperative BChE levels of ≥100 U/L was significantly higher than in those with levels of <100 U/L (89.3% versus 77.7%, P=0.004). On univariate analysis, performance status; anemia; hypoalbuminemia; preoperative levels of BChE, corrected calcium, and C-reactive protein; and distant metastasis status were significantly associated with OS. Multivariate analysis revealed that preoperative BChE levels and distant metastasis status were significantly associated with OS. Our findings suggest a possible role of preoperative BChE levels as an independent predictor of OS after nephrectomy in ccRCC patients

    Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases

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    Aims The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them. Methods and Results We performed WES of 23 probands diagnosed with early-onset (&amp;lt;65 years) CCSD and analyzed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency &amp;lt; 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as “pathogenic” by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that 2 variants in KCNH2 and SCN5A, 4 variants in SCN10A, and 1 variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from “Uncertain significance” to “Likely pathogenic” in 6 probands. Conclusions Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD. Translational Perspective Whole-exome sequencing (WES) may be helpful in determining the causes of cardiac conduction system disease (CCSD), however, the identification of pathogenic variants remains a challenge. We performed WES of 23 probands diagnosed with early-onset CCSD, and identified 12 pathogenic or likely pathogenic variants in 11 of these probands (48%) according to the 2015 ACMG standards and guidelines. In this context, functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants, and SCN10A may be one of the major development factors in CCSD

    ゲンパツ フメイ ガン ニオケル PET/CT ケンサ ノ ユウヨウセイ ニツイテ

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    We reported the utility of18F-FDG-PET/CT examination for patients with cancer of unknownprimary origin. Twenty six patients(13 men, 13 women, aged 27-91 years, mean 71)were examined.The indication for PET/CT examination was tumor maker elevation(14 patients), suspectedmetastatic tumor(14)and metastasis diagnosed histopathologically(3). Patients weretold not to eat for at least four hours and a PET/CT image was obtained one hour after theadministration of 3.7MBq/kg FDG. From April to August 2006, 33 patients diagnosed with a cancerof unknown primary origin were referred to our hospital for PET/CT examination from anoutside institution. Twenty six patients could be investigated for outcomes. Seventeen patientsshowed an abnormal accumulation, with 14 of the 17 having their primary regions detected histopathologicallyor clinically. For one patient, the abnormal accumulation could not be determined toshow the origin. For 2 patients, it was difficult to diagnose if these abnormal accumulationsshowed the primary region or not, but CT examinations were helpful for a diagnosis. Seven of the9 patients who showed no abnormal accumulation were treated conservatively and the primaryregion for their cancer could not be detected during the follow up study. In 21 of 26 patients, theseresults were useful to select an appropriate therapy to be applied or a relevant examination. Weconsidered PET/CT examination, where it is possible to scan the whole body at one time, was veryuseful to get both morphologic and metabolic information. PET/CT examination showed a highersensitivity for detecting abnormal lesions than other imaging modalities

    Epidemiology of Coronavirus Disease Outbreak among Crewmembers on Cruise Ship, Nagasaki City, Japan, April 2020

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    In April 2020, a coronavirus disease (COVID-19) outbreak occurred on the cruise ship Costa Atlantica in Nagasaki, Japan. Our outbreak investigation included 623 multinational crewmembers onboard on April 20. Median age was 31 years; 84% were men. Each crewmember was isolated or quarantined in a single room inside the ship, and monitoring of health status was supported by a remote health monitoring system. Crewmembers with more severe illness were hospitalized. The investigation found that the outbreak started in late March and peaked in late April, resulting in 149 laboratory-confirmed and 107 probable cases of infection with severe acute respiratory syndrome coronavirus 2. Six case-patients were hospitalized for COVID-19 pneumonia, including 1 in severe condition and 2 who required oxygen administration, but no deaths occurred. Although the virus can spread rapidly on a cruise ship, we describe how prompt isolation and quarantine combined with a sensitive syndromic surveillance system can control a COVID-19 outbreak
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