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Discovery of termitophilous rove beetles associated with Formosan subterranean termite Coptotermes formosanus in Taiwan, with the first larval description for the tribe Termitohospitini (Coleoptera: Staphylinidae)
Get PDFThe Formosan subterranean termite, Coptotermes formosanus Shiraki, 1909 (Blattodea: Rhinotermitidae), is a well-known pest of wood structures. Its native range has been widely investigated for potential implications for pest control strategies. Termitophilous staphylinid species of the genera Japanophilus Maruyama & Iwata, 2002 and Sinophilus Kistner, 1985 found in nests of C. formosanus have been used to infer the native range of their host termite. Herein, we extend the range of these two genera to include Taiwan, the type locality of C. formosanus. Taiwanese specimens were identifi ed as J. hojoi Maruyama & Iwata, 2002 and S. yukoae Maruyama & Iwata, 2002 based on morphological and molecular data. The fi rst-instar larva of J. hojoi is described, the fi rst known immature stage of the tribe Termitohospitini (Coleoptera: Staphylinidae: Aleocharinae).journal articl
Generation of cold Rydberg atoms at submicron distances from an optical nanofiber
Get PDFWe report on a controllable, hybrid quantum system consisting of cold Rydberg atoms and an optical nanofiber interface. Using a two-photon ladder-type excitation in 87Rb, we demonstrate both coherent and incoherent Rydberg excitation at submicron distances from the nanofiber surface. The 780-nm photon, near resonant to the 5S→5P transition, is mediated by the cooling laser, while the 482-nm light, near resonant to the 5P→29D transition, is mediated by the guided mode of the nanofiber. The population loss rate of the cold atom ensemble is used to measure the Rydberg population rate. A theoretical model is developed to interpret the results and link the population loss rate to the experimentally measured, effective Rabi frequency of the process. This work makes headway in the study of Rydberg atom-surface interactions at submicron distances and the use of cold Rydberg atoms for all-fibered quantum networks.journal articl
Macrophages directly contribute collagen to scar formation during zebrafish heart regeneration and mouse heart repair
Get PDFCanonical roles for macrophages in mediating the fibrotic response after a heart attack include extracellular matrix turnover and activation of cardiac fibroblasts to initiate collagen deposition. Here we reveal that macrophages directly contribute collagen to the forming post-injury scar. Unbiased transcriptomics shows an upregulation of collagens in both zebrafish and mouse macrophages following heart injury. Adoptive transfer of macrophages, from either collagen-tagged zebrafish or adult mouse GFPtpz-collagen donors, enhances scar formation via cell autonomous production of collagen. In zebrafish, the majority of tagged collagen localises proximal to the injury, within the overlying epicardial region, suggesting a possible distinction between macrophage-deposited collagen and that predominantly laid-down by myofibroblasts. Macrophage-specific targeting of col4a3bpa and cognate col4a1 in zebrafish significantly reduces scarring in cryoinjured hosts. Our findings contrast with the current model of scarring, whereby collagen deposition is exclusively attributed to myofibroblasts, and implicate macrophages as direct contributors to fibrosis during heart repair.journal articl
Electric-field control of single-molecule tautomerization
Get PDFThe electric field is an important parameter to vary in a single-molecule experiment, because it can directly affect the charge distribution around the molecule. Yet, performing such an experiment with a well-defined electric field for a model chemical reaction at an interface has proven to be extremely difficult. Here, by combining a graphene field-effect transistor and a gate-tunable scanning tunneling microscope (STM), we reveal how this strategy enables the intramolecular H atom transfer of a metal-free macrocycle to be controlled with an external field. Experiments and theory both elucidate how the energetic barrier to tautomerization decreases with increasing electric field. The consistency between the two results demonstrates the potential in using electric fields to engineer molecular switching mechanisms that are ubiquitous in nanoscale electronic devices.journal articl
Increase of turbulent drag by polymers in particle suspensions
Get PDFWe study the effect of spherical particles on the turbulent flow of a viscoelastic fluid and find that thedrag reducing effect ofpolymer additives is completely lostforsemidense suspensions, with the drag increasing more than for suspensions in Newtonian fluids. This different behavior is due to three separate effects. First, polymer stretching is reduced by the presence of rigid particles, thus canceling the drag reducing benefit of the viscoelastic fluid. Second, drag increase is provided by the growth of the particle and polymeric shear stresses with the particles, due to larger shear rates in the vicinity of the particle surface. Third, particles migrate towards the wall due to the shear-thinning property of the fluid, thus enhancing the particle near-wall layer and further increasing the drag.journal articl
Optical trapping and orientation-resolved spectroscopy of europium-doped nanorods
Get PDFEuropium-doped NaYF4 nanorods with a high aspect ratio are optically trapped using a single fibre tip optical tweezers. Three distinct trapping positions of the nanorods are observed: in contact with the fibre tip, close to the tip and 5 µm from the tip end. The direction and polarisation-dependent Eu3+ photoluminescence is investigated by recording the emission parallel and perpendicular to the nanorod long axis through the trapping fibre and the microscope objective, respectively. These spectroscopic measurements permit an unambiguous determination of the nanorod orientation.journal articl
Orthogonality Catastrophe as a Consequence of the Quantum Speed Limit
Get PDFA remarkable feature of quantum many-body systems is the orthogonality catastrophe that describes their extensively growing sensitivity to local perturbations and plays an important role in condensed matter physics. Here we show that the dynamics of the orthogonality catastrophe can be fully characterized by the quantum speed limit and, more specifically, that any quenched quantum many-body system, whose variance in ground state energy scales with the system size, exhibits the orthogonality catastrophe. Our rigorous findings are demonstrated by two paradigmatic classes of many-body systems—the trapped Fermi gas and the long-range interacting Lipkin-Meshkov-Glick spin model.journal articl
Many Exciplex Systems Exhibit Organic Long‐Persistent Luminescence
Get PDFOrganic long‐persistent luminescence (OLPL) is a long‐lasting luminescence from a photogenerated intermediated state, such as a charge separated state. Here, it is shown that many exciplex systems exhibit OLPL and that emission pathways of OLPL can be controlled by the relationship among local excited states and charge‐transfer excited states of materials.journal articl
Graphene based field-effect transistor biosensors functionalized using gas-phase synthesized gold nanoparticles
Get PDFResearch has focused on graphene for developing the next generation of label-free biosensors, capable of highly sensitive and specific detection of DNA or other biomolecules. The binding of charged analytes to the one-atom thick layer of graphene can greatly affect its electronic properties. However, graphene is highly chemically inert, thus surface functionalization through chemical treatment is typically necessary to immobilize receptors of the target biological analyte on the graphene. In this work, we use gas-phase synthesized gold nanoparticles (Au NPs) to functionalize and bind a DNA aptamer to the graphene surface. The graphene is employed in a liquid gated field-effect transistor (FET) configuration to detect the hybridization of the complementary DNA strand, as well as the protein streptavidin, at attomolar level (aM, 10−18 mol L−1). The sensor shows a high dynamic detecting range from aM to picomolar (pM) levels (10-18 to 10-12 mol L−1), can discriminate between a complementary strand anda single nucleotide polymorphism (SNP)containing strand, and achieves adetection limit as low as 15aM. The high detection limit suggests that decorating biosensors with Au NPs synthesized from magnetron sputtering inert gas condensing technique is a promising method for biosensor functionalization, particularly for larger-area sensors that employ two-dimensional materials such as graphene.journal articl
Numerical Simulation of A Cubic Spout-Fluid Bed: Influences of Inlet Gas Temperature and Jet to Bed Cross-Section Ratio
Get PDFIn this paper, we study the role of inlet gas temperature and jet to bed cross-section ratio on hydrodynamics and circulation patterns of particles in a spout-fluid bed. The system is modeled using CFD-TFM approach based on Eulerian-Eulerian method. Simulation results are validated by experimental data measured by (Link 2008. "PEPT and Discrete Particle Simulation Study of Spout-fluid Bed Regimes." Aiche Journal 54 (5): 1189-202). First, the sensitivity analysis of simulation results versus the most significant parameters are conducted to find the optimum values for each parameter. Subsequently, the role of inlet gas temperature and cross-section ratios are studied in detail. The simulation results clearly demonstrate that increasing the inlet gas temperature raises particles' velocity in the bed and affects the circulation pattern in annulus region. Additionally, it is shown that higher gas temperature leads to existence of hot spots in the annulus region. In case of jet to bed cross-section ratio, using larger ratios results in higher velocities and lower pressure drop along the bed.journal articl