2,121 research outputs found

    Novel Quantum Criticality in Two Dimensional Topological Phase transitions

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    Topological quantum phase transitions intrinsically intertwine self-similarity and topology of many-electron wave-functions, and divining them is one of the most significant ways to advance understanding in condensed matter physics. Our focus is to investigate an unconventional class of the transitions between insulators and Dirac semimetals whose description is beyond conventional pseudo relativistic Dirac Hamiltonian. At the transition without the long-range Coulomb interaction, the electronic energy dispersion along one direction behaves like a relativistic particle, linear in momentum, but along the other direction it behaves like a non-relativistic particle, quadratic in momentum. Various physical systems ranging from TiO2{}_2-VO2{}_2 heterostructure to organic material Ī±\alpha-(BEDT-TTF)2{}_2 I3{}_3 under pressure have been proposed to have such anisotropic dispersion relation. Here, we discover a novel quantum criticality at the phase transition by incorporating the 1/r long-range Coulomb interaction. Unique interplay between the Coulomb interaction and electronic critical modes enforces not only the anisotropic renormalization of the Coulomb interaction but also marginally modified electronic excitation. In connection with experiments, we investigate several striking effects in physical observables of our novel criticality.Comment: 12 pages + 31 pages, 5 figures, 2 tables, published versio

    Topological Phase Transitions in Line-nodal Superconductors

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    Fathoming interplay between symmetry and topology of many-electron wave-functions has deepened understanding of quantum many body systems, especially after the discovery of topological insulators. Topology of electron wave-functions enforces and protects emergent gapless excitations, and symmetry is intrinsically tied to the topological protection in a certain class. Namely, unless the symmetry is broken, the topological nature is intact. We show novel interplay phenomena between symmetry and topology in topological phase transitions associated with line-nodal superconductors. The interplay may induce an exotic universality class in sharp contrast to that of the phenomenological Landau-Ginzburg theory. Hyper-scaling violation and emergent relativistic scaling are main characteristics, and the interplay even induces unusually large quantum critical region. We propose characteristic experimental signatures around the phase transitions in three spatial dimensions, for example, a linear phase boundary in a temperature-tuning parameter phase-diagram.Comment: 4 + 23 pages, 7 figures, 1 table; the first two authors contributed equally to this wor

    Nonflammable Lithium Metal Full Cells with Ultra-high Energy Density Based on Coordinated Carbonate Electrolytes

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    Coupling thin Li metal anodes with high-capacity/high-voltage cathodes such as LiNi0.8Co0.1Mn0.1O2 (NCM811) is a promising way to increase lithium battery energy density. Yet, the realization of high-performance full cells remains a formidable challenge. Here, we demonstrate a new class of highly coordinated, nonflammable carbonate electrolytes based on lithium bis(fluorosulfonyl)imide (UFSI) in propylene carbonate/fluoroethylene carbonate mixtures. Utilizing an optimal salt concentr ation (4 M LiFSI) of the electrolyte results in a unique coordination structure of Li+-FSI-solvent cluster, which is critical for enabling the formation of stable interfaces on both the thin Li metal anode and high-voltage NCM811 cathode. Under highly demanding cell configuration and operating conditions (Li metal anode = 35 mu m, areal capacity/charge voltage of NCM811 cathode = 4.8 mAh cm(-2)/4 .6 V, and anode excess capacity [relative to the cathode] = 0.83), the Li metal-based full cell provides exceptional electrochemical performance (energy densities = 679 Wh kg(cell)(-1)/1,024 Wh L-cell(-1)) coupled with nonflammability

    Upper Gastrointestinal Tract Foreign Bodies

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    Foreign body ingestion, a common emergency encountered in clinical practice, is a potentially serious condition. Most foreign bodies in the gastrointestinal tract pass spontaneously. However, objects that are relatively long or large may lodge in the upper gastrointestinal tract, potentially causing perforation, bleeding, and obstruction. This literature review summarizes the natural history and clinical aspects of these types of foreign bodies in adults as well as the various methods for their removal. Endoscopic removal is a relatively safe and effective procedure for removing these types of foreign bodies. The development of endoscopic techniques and devices has resulted in their widespread use, with good results, as the primary treatment

    Doctors Fact-Check, Journalists Get Fact-Checked: Comparing Public Trust in Journalism and Healthcare

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    Public trust in journalism has fallen disconcertingly low. This study sets out to understand the news industryā€™s credibility crisis by comparing public perceptions of journalism with public perceptions of another institution facing similar trust challenges: healthcare. Drawing on in-depth interviews with 31 US adults, we find that although both healthcare and journalism face public distrust, members of the public generally tend to feel more trusting of individual doctors than they do of individual journalists. This is because people (a) perceive doctors to be experts in their field and (b) engage more frequently with doctors than they do with journalists. Consequently, our interviewees described treating their doctors as "fact-checkers" when it comes to health information they find online, demonstrating trust in their physicians despite their lack of trust in healthcare more broadly. Meanwhile, the opposite unfolds in journalism: Instead of using legitimate news sources to fact-check potential misinformation, people feel compelled to "fact-check" legitimate news by seeking alternative sources of corroboration. We conclude that, to improve their credibility among the public, journalists must strike the right balance between persuading the public to perceive them as experts while also pursuing opportunities to engage with the public as peers

    Comparison of Dst Forecast Models for Intense Geomagnetic Storms

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    We have compared six disturbance storm time (Dst) forecast models using 63 intense geomagnetic storms (Dst <=100 nT) that occurred from 1998 to 2006. For comparison, we estimated linear correlation coefficients and RMS errors between the observed Dst data and the predicted Dst during the geomagnetic storm period as well as the difference of the value of minimum Dst (Delta Dst(sub min)) and the difference in the absolute value of Dst minimum time (Delta t(sub Dst)) between the observed and the predicted. As a result, we found that the model by Temerin and Li gives the best prediction for all parameters when all 63 events are considered. The model gives the average values: the linear correlation coefficient of 0.94, the RMS error of 14.8 nT, the Delta Dst(sub min) of 7.7 nT, and the absolute value of Delta t(sub Dst) of 1.5 hour. For further comparison, we classified the storm events into two groups according to the magnitude of Dst. We found that the model of Temerin and Lee is better than the other models for the events having 100 <= Dst < 200 nT, and three recent models (the model of Wang et al., the model of Temerin and Li, and the model of Boynton et al.) are better than the other three models for the events having Dst <= 200 nT

    Depressed Neuronal Growth Associated Protein (GAP)-43 Expression in the Small Intestines of Mice Experimentally Infected with Neodiplostomum seoulense

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    Neodiplostomum seoulense (Digenea: Neodiplostomidae) is an intestinal trematode that can cause severe mucosal pathology in the small intestines of mice and even mortality of the infected mice within 28 days after infection. We observed neuronal growth associated protein-43 (GAP-43) expression in the myenteric plexus of the small intestinal wall of N. seoulense-infected mice until day 35 post-infection (PI). BALB/c mice were infected with 200 or 500 N. seoulense metacercariae isolated from naturally infected snakes and were killed every 7 days for immunohistochemical demonstration of GAP-43 in the small intestines. N. seoulense-infected mice showed remarkable dilatation of intestinal loops compared with control mice through days 7-28 PI. Conversely, GAP-43 expression in the mucosal myenteric plexus was markedly (P<0.05) reduced in the small intestines of N. seoulense-infected mice during days 7-28 PI and was slightly normalized at day 35 PI. From this study, it is evident that neuronal damage occurs in the intestinal mucosa of N. seoulense-infected mice. However, the correlation between intestinal pathology, including the loop dilatation, and depressed GAP-43 expression remains to be elucidated
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