3,500 research outputs found

    Electrical Investigation of the Oblique Hanle Effect in Ferromagnet/Oxide/Semiconductor Contacts

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    We have investigated the electrical Hanle effect with magnetic fields applied at an oblique angle ({\theta}) to the spin direction (the oblique Hanle effect, OHE) in CoFe/MgO/semiconductor (SC) contacts by employing a three-terminal measurement scheme. The electrical oblique Hanle signals obtained in CoFe/MgO/Si and CoFe/MgO/Ge contacts show clearly different line shapes depending on the spin lifetime of the host SC. Notably, at moderate magnetic fields, the asymptotic values of the oblique Hanle signals (in both contacts) are consistently reduced by a factor of cos^2({\theta}) irrespective of the bias current and temperature. These results are in good agreement with predictions of the spin precession and relaxation model for the electrical oblique Hanle effect. At high magnetic fields where the magnetization of CoFe is significantly tilted from the film plane to the magnetic field direction, we find that the observed angular dependence of voltage signals in the CoFe/MgO/Si and CoFe/MgO/Ge contacts are well explained by the OHE, considering the misalignment angle between the external magnetic field and the magnetization of CoFe.Comment: 19 pages, 8 figure

    Electrical spin injection and accumulation in CoFe/MgO/Ge contacts at room temperature

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    We first report the all-electrical spin injection and detection in CoFe/MgO/moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable spin signal of ~170 k{\Omega} {\mu}m^2 has been observed at RT, and the analysis using a single-step tunneling model gives a spin lifetime of ~120 ps and a spin diffusion length of ~683 nm in Ge. The observed spin signal shows asymmetric bias and temperature dependences which are strongly related to the asymmetry of the tunneling process.Comment: 28 pages, 5 figure

    Soft X-ray resonant Kerr rotation measurement and simulation of element-resolved and interface-sensitive magnetization reversals in a NiFe/FeMn/Co trilayer structure

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    We report experimental observations of element- and buried interface-resolved magnetization reversals in an oppositely exchange-biased NiFeFeMnCo trilayer structure by soft x-ray resonant Kerr rotation measurements. Not only Co-, Ni-, Fe-specific exchange-biased loops but also interfacial uncompensated (UC) Fe reversal loops coupled to the individual Co and NiFe layers are separately observed. From the experimental results interpreted with the help of the model simulations of soft x-ray resonant Kerr rotation, the effective thicknesses of interfacial UC regions at the buried interfaces of both FeMnCo and NiFeFeMn are found to be tUC =13??2 A and 6??4 A, respectively. The depth sensitivity as well as element specificity of the x-ray resonant Kerr effect offer an elegant way into the investigations of element- and depth-resolved magnetization reversals of ferromagnetic ultrathin regions at buried interfaces in multicomponent multilayer films.open91

    Transvaginal Endoscopic Appendectomy

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    Since Kalloo and colleagues first reported the feasibility and safety of a peroral transgastric approach in the porcine model in 2004, various groups have reported more complex natural orifice transluminal endoscopic surgery (NOTES) procedures, such as the cholecystectomy, splenectomy and liver biopsy, in the porcine model. Natural orifice access to the abdominal cavity, such as transgastric, transvesical, transcolonic, and transvaginal, has been described. Although a novel, minimally invasive approach to the abdominal cavity is a peroral endoscopic transgastric approach, there are still some challenging issues, such as the risk of infection and leakage, and the method of gastric closure. Hybrid-NOTES is an ideal first step in humans. Human hybrid transvaginal access has been used for years by many surgeons for diagnostic and therapeutic purposes. Here, we report a transvaginal flexible endoscopic appendectomy, with a 5-mm umbilical port using ultrasonic scissors in a 74-year-old woman with acute appendicitis

    Examining the links between burnout and suicidal ideation in diverse occupations

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    IntroductionIt is uncertain whether burnout is associated with suicidal ideation among workers not in health care services. The aim of this study was to identify how burnout and suicidal ideation are linked among employees in various occupations and whether depression affects this link.MethodsThis cross-sectional study collected data from 12,083 participants aged 19–65 years from 25 companies and public institutions who underwent workplace mental health screening. Burnout and depression were assessed using both the Oldenburg Burnout Inventory and the Center for Epidemiologic Studies Depression Scale. Suicidal ideation was assessed by a self-rated questionnaire from the Korea National Health and Nutrition Examination Survey.ResultsExhaustion but not the cynicism dimension of burnout was associated with increased odds of suicidal ideation after adjustment for depression and other covariates (odds ratio [OR] = 1.47, 95% CI = 1.26–1.72). The association of exhaustion with suicidal ideation was significant in both depressed (OR = 1.36, 95% CI = 1.14–1.61) and not depressed (OR = 1.77, 95% CI = 1.13–2.76) participants. In exhausted participants, insufficient job control, an unfavorable occupational climate, low educational level, and depression were associated with increased odds of suicidal ideation.ConclusionExhaustion is linked with risk of suicidal ideation in employees not in health care service, regardless of depression status. Exhausted employees, particularly those having poor job resources, should be recognized as an at-risk group

    Erosion problems of shore line and counter measurement by various geomaterials

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    Coastal regions are vulnerable to erosion and depletion of land areas for human habitation and economic activities. A description of various types of the hydraulic structures associated in erosion protection applications are provided. Recently, because of the shortage of natural rock, traditional forms of river and coastal structures have become very expensive to build and maintain. Therefore, the materials used in hydraulic and coastal structures are changing from the traditional rubble and concrete systems to the cheaper materials and systems. Erosion problems in coastal zones are become increasingly serious due to the development of artificial activities related to the expansion of city functions, industrial complexes and harbour facilities, as well as the removal of sea sand for use in aggregate resources at the construction sites, which is a major factor in the inflow and outflow of sea sand. In addition, the environmental and economical importance of the coastal beach zones is increased. However, coastal beach zones are constantly eroded by waves accompanied with the rising water level due to storm surges, hurricanes, winter storm impact, and high tide. This erosion motion accelerates the regression of the coastal cliff due to the regression of the dunes or the shoreline. In addition, the regression leads to loss of real estate in the hinterland and ruins the shock-absorbing zone between land and sea. The application benefits for erosion protection are discussed. Several case studies are included

    Interferon-inducible protein SCOTIN interferes with HCV replication through the autolysosomal degradation of NS5A

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    Hepatitis C virus (HCV) utilizes autophagy to promote its propagation. Here we show the autophagy-mediated suppression of HCV replication via the endoplasmic reticulum (ER) protein SCOTIN. SCOTIN overexpression inhibits HCV replication and infectious virion production in cells infected with cell culture-derived HCV. HCV nonstructural 5A (NS5A) protein, which is a critical factor for HCV RNA replication, interacts with the IFN-beta-inducible protein SCOTIN, which transports NS5A to autophagosomes for degradation. Furthermore, the suppressive effect of SCOTIN on HCV replication is impaired in both ATG7-silenced cells and cells treated with autophagy or lysosomal inhibitors. SCOTIN does not affect the overall flow of autophagy; however, it is a substrate for autophagic degradation. The physical association between the transmembrane/proline-rich domain (TMPRD) of SCOTIN and Domain-II of NS5A is essential for autophagosomal trafficking and NS5A degradation. Altogether, our findings suggest that IFN-beta-induced SCOTIN recruits the HCV NS5A protein to autophagosomes for degradation, thereby restricting HCV replication.1110Ysciescopu

    How a short double-stranded DNA bends

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    Akt regulates the expression of MafK, synaptotagmin I, and syntenin-1, which play roles in neuronal function

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    <p>Abstract</p> <p>Background</p> <p>Akt regulates various cellular processes, including cell growth, survival, and metabolism. Recently, Akt's role in neurite outgrowth has also emerged. We thus aimed to identify neuronal function-related genes that are regulated by Akt.</p> <p>Methods</p> <p>We performed suppression subtractive hybridization on two previously established PC12 sublines, one of which overexpresses the wild-type (WT) form and the other, the dominant-negative (DN) form of Akt. These sublines respond differently to NGF's neuronal differentiation effect.</p> <p>Results</p> <p>A variety of genes was identified and could be classified into several functional groups, one of which was developmental processes. Two genes involved in neuronal differentiation and function were found in this group. v-Maf musculoaponeurotic fibrosarcoma oncogene homolog K (MafK) induces the neuronal differentiation of PC12 cells and immature telencephalon neurons, and synaptotagmin I (SytI) is essential for neurotransmitter release. Another gene, <it>syntenin-1 </it>(<it>Syn-1</it>) was also recognized in the same functional group into which <it>MafK </it>and <it>SytI </it>were classified. Syn-1 has been reported to promote the formation of membrane varicosities in neurons. Quantitative reverse transcription polymerase chain reaction analyses show that the transcript levels of these three genes were lower in PC12 (WT-Akt) cells than in parental PC12 and PC12 (DN-Akt) cells. Furthermore, treatment of PC12 (WT-Akt) cells with an Akt inhibitor resulted in the increase of the expression of these genes and the improvement of neurite outgrowth. These results indicate that dominant-negative or pharmacological inhibition of Akt increases the expression of <it>MafK</it>, <it>SytI</it>, and <it>Syn-1 </it>genes. Using lentiviral shRNA to knock down endogenous Syn-1 expression, we demonstrated that Syn-1 promotes an increase in the numbers of neurites and branches.</p> <p>Conclusions</p> <p>Taken together, these results indicate that Akt negatively regulates the expression of <it>MafK</it>, <it>SytI</it>, and <it>Syn-1 </it>genes that all participate in regulating neuronal integrity in some way or another.</p
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