Graviton-Photon Conversion in Atoms and the Detection of Gravitons

We study graviton-photon conversion in ground-based experiments. From graviton to photon tran- sition, we calculate the cross section of graviton-atom interaction in the presence of spherical atomic electric fields; the obtained results hold for graviton energy around 100 keV - 1 GeV and would be enhanced by crystal structures, thus it gives a chance to catch MeV level gravitons from the universe with current neutrino facilities. From photon to graviton transition, we propose an experiment using entangled pho- ton pairs to count missing photons passing through transverse magnetic tunnel, which could be used to verify the energy quantization of gravitational field

Triply charmed baryons mass decomposition from lattice QCD

We present the first lattice QCD calculation about the mass decomposition of triply charmed baryons with $J^{P}$ as $\frac{3}{2}^{+}$ and $\frac{3}{2}^{-}$. The quark mass term $\langle H_{M} \rangle$ contributes about 66\% to the mass of $\frac{3}{2}^+$ state, which is slightly lower than that of the meson system with the same valence charm quark. Furthermore, based on our results, the total contribution of sea quarks, the gluons and the QCD anomaly accounts for about a quarter of the mass of these two triply charmed baryons. The mass difference of $\frac{3}{2}^+$ and $\frac{3}{2}^-$ states is mainly from the quark energy $\langle H_{E} \rangle$ of the QCD energy-momentum tensor. For comparison, the mass splitting is also calculated under the framework of the constituent quark model.Comment: 7 page, 14 figure

Multifunctional luminescent nanomaterials from NaLa(MoO 4) 2:Eu 3+ /Tb 3+ with tunable decay lifetimes, emission colors, and enhanced cell viability

A facile, but effective, method has been developed for large-scale preparation of NaLa(MoO 4) 2 nanorods and microflowers co-doped with Eu 3+ and Tb 3+ ions (abbreviated as: NLM:Ln 3+). The as-synthesized nanomaterials possess a pure tetragonal phase with variable morphologies from shuttle-like nanorods to microflowers by controlling the reaction temperature and the amount of ethylene glycol used. Consequently, the resulting nanomaterials exhibit superb luminescent emissions over the visible region from red through yellow to green by simply changing the relative doping ratios of Eu 3+ to Tb 3+ ions. Biocompatibility study indicates that the addition of NLM:Ln 3+ nanomaterials can stimulate the growth of normal human retinal pigment epithelium (ARPE-19) cells. Therefore, the newly-developed NaLa(MoO 4) 2 nanomaterials hold potentials for a wide range of multifunctional applications, including bioimaging, security protection, optical display, optoelectronics for information storage, and cell stimulation

Few-Shot Learning for Annotation-Efficient Nucleus Instance Segmentation

Nucleus instance segmentation from histopathology images suffers from the extremely laborious and expert-dependent annotation of nucleus instances. As a promising solution to this task, annotation-efficient deep learning paradigms have recently attracted much research interest, such as weakly-/semi-supervised learning, generative adversarial learning, etc. In this paper, we propose to formulate annotation-efficient nucleus instance segmentation from the perspective of few-shot learning (FSL). Our work was motivated by that, with the prosperity of computational pathology, an increasing number of fully-annotated datasets are publicly accessible, and we hope to leverage these external datasets to assist nucleus instance segmentation on the target dataset which only has very limited annotation. To achieve this goal, we adopt the meta-learning based FSL paradigm, which however has to be tailored in two substantial aspects before adapting to our task. First, since the novel classes may be inconsistent with those of the external dataset, we extend the basic definition of few-shot instance segmentation (FSIS) to generalized few-shot instance segmentation (GFSIS). Second, to cope with the intrinsic challenges of nucleus segmentation, including touching between adjacent cells, cellular heterogeneity, etc., we further introduce a structural guidance mechanism into the GFSIS network, finally leading to a unified Structurally-Guided Generalized Few-Shot Instance Segmentation (SGFSIS) framework. Extensive experiments on a couple of publicly accessible datasets demonstrate that, SGFSIS can outperform other annotation-efficient learning baselines, including semi-supervised learning, simple transfer learning, etc., with comparable performance to fully supervised learning with less than 5% annotations

Optical properties of a waveguide-mediated chain of randomly positioned atoms

We theoretically study the optical properties of an ensemble of two-level atoms coupled to a one-dimensional waveguide. In our model, the atoms are randomly located in the lattice sites along the one-dimensional waveguide. The results reveal that the optical transport properties of the atomic ensemble are influenced by the lattice constant and the filling factor of the lattice sites. We also focus on the atomic mirror configuration and quantify the effect of the inhomogeneous broadening in atomic resonant transition on the scattering spectrum. Furthermore, we find that initial bunching and persistent quantum beats appear in photon-photon correlation function of the transmitted field, which are significantly changed by filling factor of the lattice sites. With great progress to interface quantum emitters with nanophotonics, our results should be experimentally realizable in the near future.Comment: 11 pages, 8 figures, Accepted for publication in Optics Expres

rac-(1R,2S,6R,7R)-4-{[(1E)-(2-Chloro­phen­yl)methyl­idene]amino}-1-isopropyl-7-methyl-4-aza­tricyclo­[5.2.2.02,6]undec-8-ene-3,5-dione

The title compound, C21H23ClN2O2, was synthesized from N-amino-α-terpinene maleimide and 2-chloro­benzaldehyde. There are two independent mol­ecules in the asymmetric unit which are linked via an inter­molecular C—H⋯O hydrogen bond. The crystal studied was found to be a partial merohedral twin, with a 0.74 (7):0.26 (7) domain ratio

Musca domestica Cecropin (Mdc) Alleviates Salmonella typhimurium-Induced Colonic Mucosal Barrier Impairment: Associating With Inflammatory and Oxidative Stress Response, Tight Junction as Well as Intestinal Flora

Salmonella typhimurium, a Gram-negative food-borne pathogen, induces impairment in intestinal mucosal barrier function frequently. The injury is related to many factors such as inflammation, oxidative stress, tight junctions and flora changes in the host intestine. Musca domestica cecropin (Mdc), a novel antimicrobial peptide containing 40 amino acids, has potential antibacterial, anti-inflammatory, and immunological functions. It remains unclear exactly whether and how Mdc reduces colonic mucosal barrier damage caused by S. typhimurium. Twenty four 6-week-old male mice were divided into four groups: normal group, control group (S. typhimurium-challenged), Mdc group, and ceftriaxone sodium group (Cs group). HE staining and transmission electron microscopy (TEM) were performed to observe the morphology of the colon tissues. Bacterial load of S. typhimurium in colon, liver and spleen were determined by bacterial plate counting. Inflammatory factors were detected by enzyme linked immunosorbent assay (ELISA). Oxidative stress levels in the colon tissues were also analyzed. Immunofluorescence analysis, RT-PCR, and Western blot were carried out to examine the levels of tight junction and inflammatory proteins. The intestinal microbiota composition was assessed via 16s rDNA sequencing. We successfully built and evaluated an S. typhimurium-infection model in mice. Morphology and microcosmic change of the colon tissues confirmed the protective qualities of Mdc. Mdc could inhibit colonic inflammation and oxidative stress. Tight junctions were improved significantly after Mdc administration. Interestingly, Mdc ameliorated intestinal flora imbalance, which may be related to the improvement of tight junction. Our results shed a new light on protective effects and mechanism of the antimicrobial peptide Mdc on colonic mucosal barrier damage caused by S. typhimurium infection. Mdc is expected to be an important candidate for S. typhimurium infection treatment