87 research outputs found
TLR4 signalling in pulmonary stromal cells is critical for inflammation and immunity in the airways
Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway diseases. Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma. Pathologic changes induced by endotoxin inhalation include bronchospasm, airflow obstruction, recruitment of inflammatory cells, injury of the alveolar epithelium, and disruption of pulmonary capillary integrity leading to protein rich fluid leak in the alveolar space. Mammalian Toll-like receptors (TLRs) are important signalling receptors in innate host defense. Among these receptors, TLR4 plays a critical role in the response to endotoxin
Age-Related Changes of Myelin Basic Protein in Mouse and Human Auditory Nerve
Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38–46 years (middle-aged group) and 6 adults aged 63–91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP+ auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis
Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector
A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at
= 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb,
, and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion
Polarization Control by Using Anisotropic 3-D Chiral Structures
Due to the mirror symmetry breaking, chiral structures show fantastic
electromagnetic (EM) properties involving negative refraction, giant optical
activity, and asymmetric transmission. Aligned electric and magnetic dipoles
excited in chiral structures contribute to extraordinary properties. However,
the chiral structures that exhibit n-fold rotational symmetry show limited
tuning capability. In this paper, we proposed a compact, light, and highly
tunable anisotropic chiral structure to overcome this limitation and realize a
linear-to-circular polarization conversion. The anisotropy is due to
simultaneous excitations of two different pairs of aligned electric and
magnetic dipoles. The 3D omega-like structure, etched on two sides of one PCB
board and connected by metallic vias, achieves 60% of linearto- circular
conversion (transmission) efficiency at the operating frequency of 9.2 GHz. The
desired 90-degree phase shift between the two orthogonal linear polarization
components is not only from the finite-thickness dielectric substrate but also
from the anisotropic chiral response slightly off the resonance. The work
enables elegant and practical polarization control of EM waves.Comment: 7 pages, 10 figure
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