963 research outputs found

    More on complexity of operators in quantum field theory

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    Recently it has been shown that the complexity of SU(nn) operator is determined by the geodesic length in a bi-invariant Finsler geometry, which is constrained by some symmetries of quantum field theory. It is based on three axioms and one assumption regarding the complexity in continuous systems. By relaxing one axiom and an assumption, we find that the complexity formula is naturally generalized to the Schatten pp-norm type. We also clarify the relation between our complexity and other works. First, we show that our results in a bi-invariant geometry are consistent with the ones in a right-invariant geometry such as kk-local geometry. Here, a careful analysis of the sectional curvature is crucial. Second, we show that our complexity can concretely realize the conjectured pattern of the time-evolution of the complexity: the linear growth up to saturation time. The saturation time can be estimated by the relation between the topology and curvature of SU(nn) groups.Comment: Modified the Sec. 4.1, where we offered a powerful proof: if (1) the ket vector and bra vector in quantum mechanics contain same physics, or (2) adding divergent terms to a Lagrangian will not change underlying physics, then complexity in quantum mechanics must be bi-invariant

    Principles and symmetries of complexity in quantum field theory

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    Based on general and minimal properties of the {\it discrete} circuit complexity, we define the complexity in {\it continuous} systems in a geometrical way. We first show that the Finsler metric naturally emerges in the geometry of the complexity in continuous systems. Due to fundamental symmetries of quantum field theories, the Finsler metric is more constrained and consequently, the complexity of SU(nn) operators is uniquely determined as a length of a geodesic in the Finsler geometry. Our Finsler metric is bi-invariant contrary to the right-invariance of discrete qubit systems. We clarify why the bi-invariance is relevant in quantum field theoretic systems. After comparing our results with discrete qubit systems we show most results in kk-local right-invariant metric can also appear in our framework. Based on the bi-invariance of our formalism, we propose a new interpretation for the Schr\"{o}dinger's equation in isolated systems - the quantum state evolves by the process of minimizing "computational cost."Comment: Published version; added a short introduction on Finsler geometr

    Superconductor Pb10x_{10-x}Cux_x(PO4_4)6O_{6O} showing levitation at room temperature and atmospheric pressure and mechanism

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    A material called LK-99, a modified-lead apatite crystal structure with the composition Pb10x_{10-x}Cux_x(PO4_4)6O_{6O} (0.9<x<1.10.9<x<1.1), has been synthesized using the solid-state method. The material exhibits the Ohmic metal characteristic of Pb(6s1) above its superconducting critical temperature, TcT_c, and the levitation phenomenon as Meissner effect of a superconductor at room temperature and atmospheric pressure below TcT_c. A LK-99 sample shows TcT_c above 126.85^\circC (400 K). We analyze that the possibility of room-temperature superconductivity in this material is attributed to two factors: the first being the volume contraction resulting from an insulator-metal transition achieved by substituting Pb with Cu, and the second being on-site repulsive Coulomb interaction enhanced by the structural deformation in the one-dimensional(D) chain (Pb2-O1/2_{1/2}-Pb2 along the c-axis) structure owing to superconducting condensation at TcT_c. The mechanism of the room-temperature TcT_c is discussed by 1-D BR-BCS theory.Comment: 18 pages, 7 figure

    CCN1 Secretion Induced by Cigarette Smoking Extracts Augments IL-8 Release from Bronchial Epithelial Cells

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    Inflammation involves in many cigarette smoke (CS) related diseases including the chronic obstructive pulmonary disease (COPD). Lung epithelial cell released IL-8 plays a crucial role in CS induced lung inflammation. CS and cigarette smoke extracts (CSE) both induce IL-8 secretion and subsequently, IL-8 recruits inflammatory cells into the lung parenchyma. However, the molecular and cellular mechanisms by which CSE triggers IL-8 release remain not completely understood. In this study, we identified a novel extracellular matrix (ECM) molecule, CCN1, which mediated CSE induced IL-8 secretion by lung epithelial cells. We first found that CS and CSE up-regulated CCN1 expression and secretion in lung epithelial cells in vivo and in vitro. CSE up-regulated CCN1 via induction of reactive oxygen spices (ROS) and endoplasmic reticulum (ER) stress. p38 MAPK and JNK activation were also found to mediate the signal pathways in CSE induced CCN1. CCN1 was secreted into ECM via Golgi and membrane channel receptor aquaporin4. After CSE exposure, elevated ECM CCN1 functioned via an autocrine or paracrine manner. Importantly, CCN1 activated Wnt pathway receptor LRP6, subsequently stimulated Wnt pathway component Dvl2 and triggered beta-catenin translocation from cell membrane to cytosol and nucleus. Treatment of Wnt pathway inhibitor suppressed CCN1 induced IL-8 secretion from lung epithelial cells. Taken together, CSE increased CCN1 expression and secretion in lung epithelial cells via induction of ROS and ER stress. Increased ECM CCN1 resulted in augmented IL-8 release through the activation of Wnt pathway

    Acute Effect of Active Tibial Rotation Exercise on Tibial Torsion Angle, Ankle Range of Motion, and Neuromuscular Control

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    PURPOSE This study aimed to analyze the acute effect of active tibial rotation exercise on tibial torsion angle, ankle range of motion, and neuromuscular control. METHODS This study was based on AB/BA Cross-over design, and participants were divided into two conditions (core-tex tibial and manual tibial rotation exercises). Before and after the exercise intervention, tibial torsion angle, non-weight bearing ankle range of motion, weight-bearing ankle range of motion and dynamic balance test, and Shark skill test were conducted. RESULTS An interaction effect was found in the left non-weight-bearing ankle range of motion and the right posterolateral (PL) of the Y Balance Test. In addition, there were significant differences between periods in left tibial torsion angle, non-weight-bearing ankle range of motion, bilateral weight-bearing ankle range of motion, bilateral AN, bilateral posteromedial, right PL, bilateral composite score, and bilateral Shark skill test. CONCLUSIONS Tibial rotation exercise is considered valuable as sports injury prevention training due to its effectiveness for lower extremities functionally and structurally regardless of tibial rotation exercise type

    Genetic Variations Mir-10Aa\u3eT, Mir-30Ca\u3eG, Mir-181At\u3eC, and Mir-499Ba\u3eG and the Risk of Recurrent Pregnancy Loss in Korean Women

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    This study investigated the genetic association between recurrent pregnancy loss (RPL) and microRNA (miRNA) polymorphisms in miR-10aA\u3eT, miR-30cA\u3eG, miR-181aT\u3eC, and miR-499bA\u3eG in Korean women. Blood samples were collected from 381 RPL patients and 281 control participants, and genotyping of miR-10aA\u3eT, miR-30cA\u3eG, miR-181aT\u3eC, and miR-499bA\u3eG was carried out by TaqMan miRNA RT-Real Time polymerase chain reaction (PCR). Four polymorphisms were identified, including miR-10aA\u3eT, miR-30cA\u3eG, miR-181aT\u3eC, and miR-499bA\u3eG. MiR-10a dominant model (AA vs. AT + TT) and miR-499bGG genotypes were associated with increased RPL risk (adjusted odds ratio [AOR] = 1.520, 95% confidence interval [CI] = 1.038−2.227, p = 0.032; AOR = 2.956, 95% CI = 1.168−7.482, p = 0.022, respectively). Additionally, both miR-499 dominant (AA vs. AG + GG) and recessive (AA + AG vs. GG) models were significantly associated with increased RPL risk (AOR = 1.465, 95% CI = 1.062−2.020, p = 0.020; AOR = 2.677, 95% CI = 1.066−6.725, p = 0.036, respectively). We further propose that miR-10aA\u3eT, miR-30cA\u3eG, and miR-499bA\u3eG polymorphisms effects could contribute to RPL and should be considered during RPL patient evaluation

    An additional cysteine in a typical 2-Cys peroxiredoxin of Pseudomonas promotes functional switching between peroxidase and molecular chaperone

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    AbstractPeroxiredoxins (Prx) have received considerable attention during recent years. This study demonstrates that two typical Pseudomonas-derived 2-Cys Prx proteins, PpPrx and PaPrx can alternatively function as a peroxidase and chaperone. The amino acid sequences of these two Prx proteins exhibit 93% homology, but PpPrx possesses an additional cysteine residue, Cys112, instead of the alanine found in PaPrx. PpPrx predominates with a high molecular weight (HMW) complex and chaperone activity, whereas PaPrx has mainly low molecular weight (LMW) structures and peroxidase activity. Mass spectrometry and structural analyses showed the involvement of Cys112 in the formation of an inter-disulfide bond, the instability of LMW structures, the formation of HMW complexes, and increased hydrophobicity leading to functional switching of Prx proteins between peroxidase and chaperone
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