744 research outputs found
Radio-wave communication with chaos
This research is supported in part by National Natural Science Foundation of China (61172070), Scientific and Technological Innovation Leading Talents Program of Shaanxi Province, The Key Basic Research Fund of Shaanxi Province (2016ZDJC-01).Peer reviewedPublisher PD
The Immunomodulatory Effect of You-Gui-Wan on Dermatogoides-pteronyssinus-Induced Asthma
The traditional Chinese medicine You-Gui-Wan (YGW) contains ten species of medicinal plants and has been used to improve health in remissive states of asthma for hundreds of years in Asia. However, little is known about the immunomodulatory mechanisms in vivo. Therefore, this study investigated the pathologic and immunologic responses to YGW in mice that had been repeatedly exposed to Dermatogoides-pteronyssinus (Der p). YGW reduced Der-p-induced airway hyperresponsiveness and total IgE in serum. It also inhibited eosinophil infiltration by downregulating the protein expression of IL-5 in serum and changed the Th2-bios in BALF by upregulating IL-12. Results of the collagen assay and histopathologic examination showed that YGW reduced airway remodeling in the lung. In addition, after YGW treatment there was a relative decrease in mRNA expression of TGF-β1, IL-13, eotaxin, RANTES, and MCP-1 in lung in the YGW group. The results of EMSA and immunohistochemistry revealed that YGW inhibited NF-κB expression in epithelial lung cells. YGW exerts its regulative effects in chronic allergic asthmatic mice via its anti-inflammatory activity and by inhibiting the progression of airway remodeling
Enhanced inhibitory synaptic transmission in the spinal dorsal horn mediates antinociceptive effects of TC-2559
<p>Abstract</p> <p>Background</p> <p>TC-2559 is a selective α4β2 subtype of nicotinic acetylcholine receptor (nAChR) partial agonist and α4β2 nAChR activation has been related to antinociception. The aim of this study is to investigate the analgesic effect of TC-2559 and its underlying spinal mechanisms.</p> <p>Results</p> <p>1) <it>In vivo </it>bioavailability study: TC-2559 (3 mg/kg) had high absorption rate in rats with maximal total brain concentration reached over 4.6 μM within first 15 min after administration and eliminated rapidly with brain half life of about 20 min after injection. 2) <it>In vivo </it>behavioral experiments: TC-2559 exerts dose dependent antinociceptive effects in both formalin test in mice and chronic constriction injury (CCI) model in rats by activation of α4β2 nAChRs; 3) Whole-cell patch-clamp studies in the superficial dorsal horn neurons of the spinal cord slices: perfusion of TC-2559 (2 μM) significantly increased the frequency, but not amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs). The enhancement of sIPSCs was blocked by pre-application of DHβE (2 μM), a selective α4β2 nicotinic receptor antagonist. Neither the frequency nor the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) of spinal dorsal horn neurons were affected by TC-2559.</p> <p>Conclusions</p> <p>Enhancement of inhibitory synaptic transmission in the spinal dorsal horn via activation of α4β2 nAChRs may be one of the mechanisms of the antinociceptive effects of TC-2559 on pathological pain models. It provides further evidence to support the notion that selective α4β2 subtype nAChR agonist may be developed as new analgesic drug for the treatment of neuropathic pain.</p
Observation of Non-Hermitian Skin Effect in Thermal Diffusion
The paradigm shift of the Hermitian systems into the non-Hermitian regime
profoundly modifies the inherent topological property, leading to various
unprecedented effects such as the non-Hermitian skin effect (NHSE). In the past
decade, the NHSE effect has been demonstrated in quantum, optical and acoustic
systems. Besides in those non-Hermitian wave systems, the NHSE in diffusive
systems has not yet been explicitly demonstrated, despite recent abundant
advances in the study of topological thermal diffusion. Here we first design a
thermal diffusion lattice based on a modified Su-Schrieffer-Heeger model which
enables the observation of diffusive NHSE. In the proposed model, the periodic
heat exchange rate among adjacent unit cells and the asymmetric temperature
field coupling inside unit cells can be judiciously realized by appropriate
configurations of structural parameters of unit cells. The transient
concentration feature of temperature field on the boundary regardless of
initial excitation conditions can be clearly observed, indicating the
occurrence of transient thermal skin effect. Nonetheless, we experimentally
demonstrated the NHSE and verified the remarkable robustness against various
defects. Our work provides a platform for exploration of non-Hermitian physics
in the diffusive systems, which has important applications in efficient heat
collection, highly sensitive thermal sensing and others.Comment: 23 pages, 5 figure
Combining ketamine with astrocytic inhibitor as a potential analgesic strategy for neuropathic pain. ketamine, astrocytic inhibitor and pain
<p>Abstract</p> <p>Background</p> <p>Neuropathic pain is an intractable clinical problem. Intrathecal ketamine, a noncompetitive N--methyl-D-aspartate receptor (NMDAR) antagonist, is reported to be useful for treating neuropathic pain in clinic by inhibiting the activity of spinal neurons. Nevertheless, emerging studies have disclosed that spinal astrocytes played a critical role in the initiation and maintenance of neuropathic pain. However, the present clinical therapeutics is still just concerning about neuronal participation. Therefore, the present study is to validate the coadministration effects of a neuronal noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine and astrocytic cytotoxin L-α-aminoadipate (LAA) on spinal nerve ligation (SNL)-induced neuropathic pain.</p> <p>Results</p> <p>Intrathecal ketamine (10, 100, 1000 μg/kg) or LAA (10, 50, 100 nmol) alleviated SNL-induced mechanical allodynia in a dose-dependent manner respectively. Phosphorylated NR1 (pNR1) or glial fibrillary acidic protein (GFAP) expression was down-regulated by intrathecal ketamine (100, 1000 μg/kg) or LAA (50, 100 nmol) respectively. The combination of ketamine (100 μg/kg) with LAA (50 nmol) showed superadditive effects on neuropathic pain compared with that of intrathecal administration of either ketamine or LAA alone. Combined administration obviously relieved mechanical allodynia in a quick and stable manner. Moreover, down-regulation of pNR1 and GFAP expression were also enhanced by drugs coadministration.</p> <p>Conclusions</p> <p>These results suggest that combining NMDAR antagonist ketamine with an astrocytic inhibitor or cytotoxin, which is suitable for clinical use once synthesized, might be a potential strategy for clinical management of neuropathic pain.</p
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Creating Ferromagnetic Insulating La0.9Ba0.1MnO3 Thin Films by Tuning Lateral Coherence Length
In this work, heteroepitaxial vertically aligned nanocomposite (VAN) La0.9Ba0.1MnO3 (LBMO)-CeO2 films are engineered to produce ferromagnetic insulating (FMI) films. From combined X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy, the elimination of the insulator-metal (I-M) transition is shown to result from the creation of very small lateral coherence lengths (with the corresponding lateral size ~ 3 nm (~ 7 u.c.)) in the LBMO matrix, achieved by engineering a high density of CeO2 nanocolumns in the matrix. The small lateral coherence length leads to a shift in the valence band maximum and reduction of the double exchange (DE) coupling. There is no "dead layer" effect at the smallest lateral coherence length achieved of ~ 3 nm. The FMI behaviour obtained by lateral dimensional tuning is independent of substrate interactions, thus intrinsic to the film itself and hence not related to film thickness. The unique properties of VAN films give the possibility for multilayer spintronic devices that can be made without interface degradation effects between the layers.Royal Academy of Engineering - CIET1819_24,
the Leverhulme Trust grant RPG-2015-017,
EPSRC grants EP/N004272/1, EP/T012218/1, and EP/M000524/1,
the Isaac Newton Trust in Cambridge (minute 16.24(p) and RG96474).
EU grant H2020-MSCA-IF-2016 (745886)-MuStMAM
Observing parity-time symmetry in diffusive systems
Phase modulation has scarcely been mentioned in diffusive systems since the
diffusion process does not carry momentum like waves. Recently, the
non-Hermitian physics provides a new perspective for understanding diffusion
and shows prospects in the phase regulation of heat flow, for example, the
discovery of anti-parity-time (APT) symmetry in diffusive systems. The precise
control of thermal phase however remains elusive hitherto and can hardly be
realized in APT-symmetric thermal systems due to the existence of phase
oscillation. Here we construct the counterpart of APT-symmetric diffusive
systems, i.e., PT-symmetric diffusive systems, which can achieve complete
suppression of thermal phase oscillation. We find the real coupling of
diffusive fields can be readily established through a strong convective
background, where the decay-rate detuning is enabled by thermal metamaterial
design. Moreover, we observe phase transition of PT symmetry breaking in
diffusive systems with the symmetry-determined amplitude distribution and phase
regulation of coupled temperature fields. Our work uncovers the existence of
PT-symmetry in dissipative energy exchanges and provides a unique approach for
harnessing the mass transfer of particles, the wave propagation in strongly
scattering systems as well as thermal conduction
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