856 research outputs found

    Activation of a prophage‐encoded tyrosine kinase by a heterologous infecting phage results in a self‐inflicted abortive infection

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87011/1/j.1365-2958.2011.07847.x.pd

    Origin of Temperature-Dependent Ferroelectricity in SiDoped HfO₂

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    The structural origin of the temperature-dependent ferroelectricity in Si-doped HfO₂ thin films is systematically examined. From temperature-dependent polarization-electric field measurements, it is shown that remanent polarization increases with decreasing temperature. Concurrently, grazing incidence X-ray diffraction shows an increase in the orthorhombic phase fraction with decreasing temperature. The temperature-dependent evolution of structural and ferroelectric properties is believed to be highly promising for the electrocaloric cooling application. Magnetization measurements do not provide any indication for a change of magnetization within the temperature range for the strong crystalline phase transition, suggesting that magnetic and structural properties are comparatively decoupled. The results are believed to provide the first direct proof of the strongly coupled evolution of structural and electrical properties with varying temperature in fluorite oxide ferroelectrics

    Effect of Annealing Ferroelectric HfO₂ Thin Films: In Situ, High Temperature X-Ray Diffraction

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    The ferroelectricity in fluorite oxides has gained increasing interest due to its promising properties for multiple applications in semiconductor as well as energy devices. The structural origin of the unexpected ferroelectricity is now believed to be the formation of a non-centrosymmetric orthorhombic phase with the space group of Pca2₁. However, the factors driving the formation of the ferroelectric phase are still under debate. In this study, to understand the effect of annealing temperature, the crystallization process of doped HfO₂ thin films is analyzed using in situ, high-temperature X-ray diffraction. The change in phase fractions in a multiphase system accompanied with the unit cell volume increase during annealing could be directly observed from X-ray diffraction analyses, and the observations give an information toward understanding the effect of annealing temperature on the structure and electrical properties. A strong coupling between the structure and the electrical properties is reconfirmed from this result

    Regulation of shear-induced nuclear translocation of the Nrf2 transcription factor in endothelial cells

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    <p>Abstract</p> <p>Background</p> <p>Vascular endothelial cells (ECs) constantly experience fluid shear stresses generated by blood flow. Laminar flow is known to produce atheroprotective effects on ECs. Nrf2 is a transcription factor that is essential for the antioxidant response element (ARE)-mediated induction of genes such as heme-oxygenase 1 (HO-1). We previously showed that fluid shear stress increases intracellular reactive oxygen species (ROS) in ECs. Moreover, oxidants are known to stimulate Nrf2. We thus examined the regulation of Nrf2 in cultured human ECs by shear stress.</p> <p>Results</p> <p>Exposure of human umbilical vein endothelial cells (HUVECs) to laminar shear stress (12 dyne/cm<sup>2</sup>) induced Nrf2 nuclear translocation, which was inhibited by a phosphatidylinositol 3-kinase (PI3K) inhibitor, a protein kinase C (PKC) inhibitor, and an antioxidant agent N-acetyl cysteine (NAC), but not by other protein kinase inhibitors. Therefore, PI3K, PKC, and ROS are involved in the signaling pathway that leads to the shear-induced nuclear translocation of Nrf2. We also found that shear stress increased the ARE-binding activity of Nrf2 and the downstream expression of HO-1.</p> <p>Conclusion</p> <p>Our data suggest that the atheroprotective effect of laminar flow is partially attributed to Nrf2 activation which results in ARE-mediated gene transcriptions, such as HO-1 expression, that are beneficial to the cardiovascular system.</p

    The Effect of Galaxy Interactions on Molecular Gas Properties

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    © 2018. The American Astronomical Society. All rights reserved.Galaxy interactions are often accompanied by an enhanced star formation rate (SFR). Since molecular gas is essential for star formation, it is vital to establish whether and by how much galaxy interactions affect the molecular gas properties. We investigate the effect of interactions on global molecular gas properties by studying a sample of 58 galaxies in pairs and 154 control galaxies. Molecular gas properties are determined from observations with the JCMT, PMO, and CSO telescopes and supplemented with data from the xCOLD GASS and JINGLE surveys at 12CO(1-0) and 12CO(2-1). The SFR, gas mass (), and gas fraction (f gas) are all enhanced in galaxies in pairs by ∼2.5 times compared to the controls matched in redshift, mass, and effective radius, while the enhancement of star formation efficiency (SFE ≡SFR/) is less than a factor of 2. We also find that the enhancements in SFR, and f gas, increase with decreasing pair separation and are larger in systems with smaller stellar mass ratio. Conversely, the SFE is only enhanced in close pairs (separation <20 kpc) and equal-mass systems; therefore, most galaxies in pairs lie in the same parameter space on the SFR- plane as controls. This is the first time that the dependence of molecular gas properties on merger configurations is probed statistically with a relatively large sample and a carefully selected control sample for individual galaxies. We conclude that galaxy interactions do modify the molecular gas properties, although the strength of the effect is dependent on merger configuration.Peer reviewedFinal Accepted Versio

    Joint relationship between renal function and proteinuria on mortality of patients with type 2 diabetes: The Taichung Diabetes Study

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    Abstract Background Estimated glomerular filtration rate (eGFR) is a powerful predictor of mortality in diabetic patients with limited proteinuria data. In this study, we tested whether concomitant proteinuria increases the risk of mortality among patients with type 2 diabetes. Methods Participants included 6523 patients > 30 years with type 2 diabetes who were enrolled in a management program of a medical center before 2007. Renal function was assessed by eGFR according to the Modification of Diet in Renal Disease Study equation for Chinese. Proteinuria was assessed by urine dipstick. Results A total of 573 patients (8.8%) died over a median follow-up time of 4.91 years (ranging from 0.01 year to 6.42 years). The adjusted expanded cardiovascular disease (CVD)-related mortality rates among patients with proteinuria were more than three folds higher for those with an eGFR of 60 mL/min/1.73 m2 or less compared with those with an eGFR of 90 mL/min/1.73 m2 or greater [hazard ratio, HR, 3.15 (95% confidence interval, CI, 2.0–5.1)]. The magnitude of adjusted HR was smaller in patients without proteinuria [1.98 (95% CI, 1.1–3.7)]. An eGFR of 60 mL/min/1.73 m2 to 89 mL/min/1.73 m2 significantly affected all-cause mortality and mortality from expanded CVD-related causes only in patients with proteinuria. Similarly, proteinuria affected all outcomes only in patients with an eGFR of <60 mL/min/1.73 m2. Conclusion The risks of all-cause mortality, as well as expanded and non-expanded mortality from CVD-related causes associated with proteinuria or an eGFR of 90 mL/min/1.73 m2 or greater are independently increased. Therefore, the use of proteinuria measurements with eGFR increases the precision of risk stratification for mortality.http://deepblue.lib.umich.edu/bitstream/2027.42/112804/1/12933_2012_Article_558.pd

    Controle de arritmias atriais com período refratário atrial controlado por sensor e mudança automática de modo em pacientes portadores de marcapasso dupla-câmara com sensor de ventilaçao por minuto

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    Apesar de um longo período refratário atrial pós evento ventricular (PVARP) poder prevenir a ocorrência de taquicardias mediadas pelo marca passo e também o sincronismo inapropriado com arritmias atriais na estimulaçao dupla-câmara (DDD) a limitaçao da freqüência máxima será necessariamente comprometida. Testamos a possibilidade de utilizar um marca passo dupla-câmara com sensor de ventilaçao por minuto (DDDR) e com capacidade de encurtar o PVARP durante o exercício em 13 pacientes com bradicardia (PVARP em repouso = 463 ± 29 ms) a fim de prevenir a limitaçao prematura da freqüência máxima. O teste de esforço em esteira nos modos DDD e DDDR com este PVARP resultou em freqüências máximas de 98 bpm ± 8 bpm e 142 bpm ± 3 bpm respectivamente (P < 0,DDD1). Estes resultados foram obtidos graças à incompetência cronotrópica e à limitaçao da freqüência máxima no modo DDD, ambas contornadas pelo uso do sensor. Com a finalidade de simular arritmias atriais, foi aplicada estimulaçao na parede torácica por 30 segundos, a uma freqüência de 250 bpm e com uma sensibilidade atrial uni polar média de 0,82 mV. No modo DDD, ocorreu uma resposta ventricular irregular (as freqüências com um PVARP de 280 ms e 463 ms ± 29 ms foram respectivamente 92 bpm ± 5 bpm e 66 bpm ± 3 bpm (P < 0,DDD1). No modo DDDR, com um PVARP de 463 ms ± 29 ms, ocorreu uma estimulaçao ventricular regular a 53 bpm ± 2 bpm, devida à mudança de mDDD para VVIR, na presença de eventos repetitivos captados dentro do PVARP. Um paciente desenvolveu fibrilaçao atrial espontânea durante o seguimento, que foi corretamente identificada pelo algoritmo do marcapasso, resultando na mudança de modo de DDDR para WIR e na preservaçao da resposta em freqüência. Em conclusao, o PVARP controlado pelo sensor permite a utilizaçao de um PVARP mais longo durante o repouso, sem comprometer a freqüência máxima durante o exercício. Adicionalmente, ao oferecer em proteçao contra conduçao retrógrada, o PVARP longo e a mudança automática de mDDD também limitam a freqüência durante as arritmias atriais, permitindo uma resposta ventricular de acordo com a demanda fisiológica

    Functional role of ICAM-3 polymorphism in genetic susceptibility to SARS infection.

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    Key Messages 1. Severe acute respiratory syndrome (SARS) patients who are homozygous for intercellular adhesion molecule-3 (ICAM-3) Gly143 showed significant association with higher lactate dehydrogenase levels and lower total white blood cell counts on admission. 2. In vitro functional studies demonstrated low level binding of ICAM-3 to DC-SIGN and a wide variation in T-cell response of the wild-type ICAM-3 genotype.published_or_final_versio

    The 2021 flexible and printed electronics roadmap

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    This roadmap includes the perspectives and visions of leading researchers in the key areas of flexible and printable electronics. The covered topics are broadly organized by the device technologies (sections 1–9), fabrication techniques (sections 10–12), and design and modeling approaches (sections 13 and 14) essential to the future development of new applications leveraging flexible electronics (FE). The interdisciplinary nature of this field involves everything from fundamental scientific discoveries to engineering challenges; from design and synthesis of new materials via novel device design to modelling and digital manufacturing of integrated systems. As such, this roadmap aims to serve as a resource on the current status and future challenges in the areas covered by the roadmap and to highlight the breadth and wide-ranging opportunities made available by FE technologies
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