6 research outputs found

    The particle surface of spinning test particles

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    In this work, inspired by the definition of the photon surface given by Claudel, Virbhadra, and Ellis, we give an alternative quasi-local definition to study the circular orbits of single-pole particles. This definition does not only apply to photons but also to massive point particles. For the case of photons in spherically symmetric spacetime, it will give a photon surface equivalent to the result of Claudel, Virbhadra, and Ellis. Meanwhile, in general static and stationary spacetime, this definition can be regarded as a quasi-local form of the effective potential method. However, unlike the effective potential method which can not define the effective potential in dynamical spacetime, this definition can be applied to dynamical spacetime. Further, we generalize this definition directly to the case of pole-dipole particles. In static spherical symmetry spacetime, we verify the correctness of this generalization by comparing the results obtained by the effective potential method.Comment: 12pages, no figures; accepted by The European Physical Journal C; the title has been revies

    The particle surface of spinning test particles

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    Abstract In this work, inspired by the definition of the photon surface given by Claudel, Virbhadra, and Ellis, we give an alternative quasi-local definition to study the circular orbits of single-pole particles. This definition does not only apply to photons but also to massive point particles. For the case of photons in spherically symmetric spacetime, it will give a photon surface equivalent to the result of Claudel, Virbhadra, and Ellis. Meanwhile, in general static and stationary spacetime, this definition can be regarded as a quasi-local form of the effective potential method. However, unlike the effective potential method which can not define the effective potential in dynamical spacetime, this definition can be applied to dynamical spacetime. Further, we generalize this definition directly to the case of pole–dipole particles. In static spherical symmetry spacetime, we verify the correctness of this generalization by comparing the results obtained by the effective potential method

    The investigation on the hypercoagulability of hepatocellular carcinoma‐related cerebral infarction with thromboelastography

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    Abstract Aim To investigate the hypercoagulability of hepatocellular carcinoma (HCC)‐related cerebral infarction (HCRCI) with thromboelastography (TEG). Methods A multicenter prospective study was conducted in HCRCI patients, HCC patients without cerebral infarction, and acute cerebral infarction (ACI) patients without HCC between January 2016 and December 2019. TEG parameters and laboratory and clinical data were collected and compared among the three groups. To confirm the independent risk factors of HCRCI, multivariate analyses were conducted. Receiver operating characteristic (ROC) curves were utilized to evaluate the area under the curve (AUC) plotted by each independent risk factor. Results There were 38 patients recruited in the HCRCI group, and 152 patients were recruited to the HCC group and the ACI group. The levels of plasma neutrophil count, D‐dimer, α‐fetoprotein (AFP), carcinoembryonic antigen, and maximum amplitude (MA)—a parameter of TEG—were significantly higher in the HCRCI group than HCC and ACI groups. Multivariate logistic regression analysis showed that increased neutrophile count, D‐dimer, AFP, and MA were independently associated with HCRCI. ROC curve analysis showed first that AUC of MA for HCRCI was .875, which was larger than the other risk factors, and second that the optimal cutoff value for MA was 61.35, with a sensitivity of 89.50% and specificity of 66.40%. Conclusion It was suggested that TEG disclosed that the pathogenesis of HCRIC is exactly related to the hypercoagulability. And with a cutoff value of MA equaling to 61.35, TEG facilitates clinicians to identify HCC patients at high risk of HCRIC

    <i>LEAF TIP RUMPLED 1</i> Regulates Leaf Morphology and Salt Tolerance in Rice

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    Leaf morphology is one of the important traits related to ideal plant architecture and is an important factor determining rice stress resistance, which directly affects yield. Wax layers form a barrier to protect plants from different environmental stresses. However, the regulatory effect of wax synthesis genes on leaf morphology and salt tolerance is not well-understood. In this study, we identified a rice mutant, leaf tip rumpled 1 (ltr1), in a mutant library of the classic japonica variety Nipponbare. Phenotypic investigation of NPB and ltr1 suggested that ltr1 showed rumpled leaf with uneven distribution of bulliform cells and sclerenchyma cells, and disordered vascular bundles. A decrease in seed-setting rate in ltr1 led to decreased per-plant grain yield. Moreover, ltr1 was sensitive to salt stress, and LTR1 was strongly induced by salt stress. Map-based cloning of LTR1 showed that there was a 2-bp deletion in the eighth exon of LOC_Os02g40784 in ltr1, resulting in a frameshift mutation and early termination of transcription. Subsequently, the candidate gene was confirmed using complementation, overexpression, and knockout analysis of LOC_Os02g40784. Functional analysis of LTR1 showed that it was a wax synthesis gene and constitutively expressed in entire tissues with higher relative expression level in leaves and panicles. Moreover, overexpression of LTR1 enhanced yield in rice and LTR1 positively regulates salt stress by affecting water and ion homeostasis. These results lay a theoretical foundation for exploring the molecular mechanism of leaf morphogenesis and stress response, providing a new potential strategy for stress-tolerance breeding
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