922 research outputs found

    One Small Step for an Inflaton, One Giant Leap for Inflation: a novel non-Gaussian tail and primordial black holes

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    We report a novel prediction from single-field inflation that even a tiny step in the inflaton potential can change our perception of primordial non-Gaussianities of the curvature perturbation. Our analysis focuses on the tail of probability distribution generated by an upward step transition between two stages of slow-roll evolution. The nontrivial background dynamics with off-attractor behavior is identified. By using a non-perturbative δN\delta N analysis, we explicitly show that a highly non-Gaussian tail can be generated by a tiny upward step, even when the conventional nonlinearity parameters fNLf_{NL}, gNLg_{NL}, etc. remain small. With this example, we demonstrate for the first time the sensitive dependence of non-perturbative effects on the tail of probability distribution. Our scenario has an inconceivable application to primordial black holes by either significantly boosting their abundance or completely forbidding their appearance.Comment: 7 pages, 4 figure

    Enhanced excitability of small dorsal root ganglion neurons in rats with bone cancer pain

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    <p>Abstract</p> <p>Background</p> <p>Primary and metastatic cancers that affect bone are frequently associated with severe and intractable pain. The mechanisms underlying the development of bone cancer pain are largely unknown. The aim of this study was to determine whether enhanced excitability of primary sensory neurons contributed to peripheral sensitization and tumor-induced hyperalgesia during cancer condition. In this study, using techniques of whole-cell patch-clamp recording associated with immunofluorescent staining, single-cell reverse-transcriptase PCR and behavioral test, we investigated whether the intrinsic membrane properties and the excitability of small-sized dorsal root ganglion (DRG) neurons altered in a rat model of bone cancer pain, and whether suppression of DRG neurons activity inhibited the bone cancer-induced pain.</p> <p>Results</p> <p>Our present study showed that implantation of MRMT-1 tumor cells into the tibial canal in rats produced significant mechanical and thermal hyperalgesia in the ipsilateral hind paw. Moreover, implantation of tumor cells provoked spontaneous discharges and tonic excitatory discharges evoked by a depolarizing current pulse in small-sized DRG neurons. In line with these findings, alterations in intrinsic membrane properties that reflect the enhanced neuronal excitability were observed in small DRG neurons in bone cancer rats, of which including: 1) depolarized resting membrane potential (RMP); 2) decreased input resistance (R<sub>in</sub>); 3) a marked reduction in current threshold (CT) and voltage threshold (TP) of action potential (AP); 4) a dramatic decrease in amplitude, overshot, and duration of evoked action potentials as well as in amplitude and duration of afterhyperpolarization (AHP); and 5) a significant increase in the firing frequency of evoked action potentials. Here, the decreased AP threshold and increased firing frequency of evoked action potentials implicate the occurrence of hyperexcitability in small-sized DRG neurons in bone cancer rats. In addiotion, immunofluorescent staining and single-cell reverse-transcriptase PCR revealed that in isolated small DRG neurons, most neurons were IB4-positive, or expressed TRPV1 or CGRP, indicating that most recorded small DRG neurons were nociceptive neurons. Finally, using in vivo behavioral test, we found that blockade of DRG neurons activity by TTX inhibited the tumor-evoked mechanical allodynia and thermal hyperalgesia in bone cancer rats, implicating that the enhanced excitability of primary sensory neurons underlied the development of bone cancer pain.</p> <p>Conclusions</p> <p>Our present results suggest that implantation of tumor cells into the tibial canal in rats induces an enhanced excitability of small-sized DRG neurons that is probably as results of alterations in intrinsic electrogenic properties of these neurons. Therefore, alterations in intrinsic membrane properties associated with the hyperexcitability of primary sensory neurons likely contribute to the peripheral sensitization and tumor-induced hyperalgesia under cancer condition.</p

    Effect of edaravone-urinary kallidinogenase combination treatment on acute cerebral infarction

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    Purpose: To investigate the curative effect of edaravone in combination with urinary kallidinogenase in the treatment of acute cerebral infarction and its effect on serum high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL).Methods: One hundred and eighty patients with acute cerebral infarction (ACI) who were on admission from March 2015 to July 2016 participated in this study as research subjects. They were assigned to study group (59 patients) and control group (59 patients). Edaravone and conventional treatment were administered to the control group. In contrast, in addition to conventional treatment, the study group was given edaravone in combination with urinary kallidinogenase. Clinical effects, neurological function and serum IL-17 and hs-CRP levels in the two groups were determined.Results: The overall response of the study group was significantly higher than that of the control group (p &lt; 0.05). Scores in the National Institute of Health stroke scale (NIHSS) were reduced in both groups, and modified Barthel index (MBI) of both groups remarkably increased, when compared to values before treatment. Improvements in NIHSS score and MBI of the study group were higher than those of the control group (p &lt; 0.05). Serum IL-17 and hs-CRP levels declined significantly in the two groups (p &lt; 0.05), but post-treatment serum IL-17 and hs-CRP levels of the study group were significantly reduced, relative to control values (p &lt; 0.05). There were no significant differences in incidence of adverse reactions between the two groups.Conclusion: The use of edaravone in combination with urinary kallidinogenase in the treatment of ACI can significantly reduce serum IL-17 and hs-CRP levels without inducing severe adverse reactions.Keywords: Edaravone, Urinary kallidinogenase, Acute cerebral infarctio

    1-Resilient Boolean Functions on Even Variables with Almost Perfect Algebraic Immunity

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    Several factors (e.g., balancedness, good correlation immunity) are considered as important properties of Boolean functions for using in cryptographic primitives. A Boolean function is perfect algebraic immune if it is with perfect immunity against algebraic and fast algebraic attacks. There is an increasing interest in construction of Boolean function that is perfect algebraic immune combined with other characteristics, like resiliency. A resilient function is a balanced correlation-immune function. This paper uses bivariate representation of Boolean function and theory of finite field to construct a generalized and new class of Boolean functions on even variables by extending the Carlet-Feng functions. We show that the functions generated by this construction support cryptographic properties of 1-resiliency and (sub)optimal algebraic immunity and further propose the sufficient condition of achieving optimal algebraic immunity. Compared experimentally with Carlet-Feng functions and the functions constructed by the method of first-order concatenation existing in the literature on even (from 6 to 16) variables, these functions have better immunity against fast algebraic attacks. Implementation results also show that they are almost perfect algebraic immune functions

    Calorimetric Evidence for Nodes in the Overdoped Ba(Fe0.9_{0.9}Co0.1_{0.1})2_{2}As2_{2}

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    We present low-temperature specific heat of the electron-doped Ba(Fe0.9_{0.9}Co0.1_{0.1})2_{2}As2_{2}, which does not show any indication of an upturn down to 400 mK, the lowest measuring temperature. The lack of a Schottky-like feature at low temperatures or in magnetic fields up to 9 Tesla enables us to identify enhanced low-temperature quasiparticle excitations and to study anisotropy in the linear term of the specific heat. Our results can not be explained by a single or multiple isotropic superconducting gap, but are consistent with multi-gap superconductivity with nodes on at least one Fermi surface sheet.Comment: 5 pages 4 figure
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