Regulation of Marginal Zone B-Cell Differentiation by MicroRNA-146a.

B-cell development in the bone marrow is followed by specification into functional subsets in the spleen, including marginal zone (MZ) B-cells. MZ B-cells are classically characterized by T-independent antigenic responses and require the elaboration of distinct gene expression programs for development. Given their role in gene regulation, it is not surprising that microRNAs are important factors in B-cell development. Recent work demonstrated that deficiency of the NFκB feedback regulator, miR-146a, led to a range of hematopoietic phenotypes, but B-cell phenotypes have not been extensively characterized. Here, we found that miR-146a-deficient mice demonstrate a reduction in MZ B-cells, likely from a developmental block. Utilizing high-throughput sequencing and comparative analysis of developmental stage-specific transcriptomes, we determined that MZ cell differentiation was impaired due to decreases in Notch2 signaling. Our studies reveal miR-146a-dependent B-cell phenotypes and highlight the complex role of miR-146a in the hematopoietic system

Enhanced Transmission of Light and Particle Waves through Subwavelength Nanoapertures by Far-Field Interference

Subwavelength aperture arrays in thin metal films can enable enhanced transmission of light and matter (atom) waves. The phenomenon relies on resonant excitation and interference of the plasmon or matter waves on the metal surface. We show a new mechanism that could provide a great resonant and nonresonant transmission enhancement of the light or de Broglie particle waves passed through the apertures not by the surface waves, but by the constructive interference of diffracted waves (beams generated by the apertures) at the detector placed in the far-field zone. In contrast to other models, the mechanism depends neither on the nature (light or matter) of the beams (continuous waves or pulses) nor on material and shape of the multiple-beam source (arrays of 1-D and 2-D subwavelength apertures, fibers, dipoles or atoms). The Wood anomalies in transmission spectra of gratings, a long standing problem in optics, follow naturally from the interference properties of our model. The new point is the prediction of the Wood anomaly in a classical Young-type two-source system. The new mechanism could be interpreted as a non-quantum analog of the superradiance emission of a subwavelength ensemble of atoms (the light power and energy scales as the number of light-sources squared, regardless of periodicity) predicted by the well-known Dicke quantum model.Comment: Revised version of MS presented at the Nanoelectronic Devices for Defense and Security (NANO-DDS) Conference, 18-21 June, 2007, Washington, US

A supramolecular self-assembly strategy for upconversion nanoparticle bioconjugation

© 2018 The Royal Society of Chemistry. An efficient surface modification for upconversion nanoparticles (UCNPs) is reported via supramolecular host-guest self-assembly. Cucurbit[7]uril (CB) can provide a hydrophilic surface and cavities for most biomolecules. High biological efficiency, activity and versatility of the approach enable UCNPs to be significantly applied in bio-imaging, early disease detection, and bio-sensing

Combined chemotherapy and radiotherapy for patients with breast cancer and extensive nodal involvement

Purpose: This retrospective review examines local control, freedom from distant failure, and survival for patients with nonmetastatic breast cancer with extensive nodal disease (> 10 nodes, 45 patients; or greater than or equal to 70% involved nodes if < 10 nodes found, 19 patients). All patients received chemotherapy and radiotherapy following mastectomy

Fate of Z(N) walls in hot holographic QCD

We first study Z(N) walls in a deconfined phase of Witten's D4-brane background of pure SU(N) Yang-Mills theory, motivated by a recent work in the case of N=4 SYM. Similarly to it, we propose that for a large wall charge k ~ N, it is described by k D2-branes blown up into a NS5-brane wrapping S^3 inside S^4 via Myers effect, and we calculate the tension by suitable U-duality. We find a precise Casimir scaling for the tension formula. We then study the fate of Z(N)-vacua in a presence of fundamental flavors in quenched approximation via gauge/gravity correspondence. In the case of D3/D7 system where one can vary the mass m_q of flavors, we show that there is a phase transition at T_c ~ m_q, below which the Z(N)-vacua survive while they are lifted above the critical temperature. We analytically calculate the energy lift of k'th vacua in the massless case, both in the D3/D7 system and in the Sakai-Sugimoto model.Comment: 24 pages, v2: references updated, v3: A clarification on the meaning of Z(N) walls in Euclidean space added, citations update

Tachyon Kinks in Boundary String Field Theory

We study tachyon kinks with and without electromagnetic fields in the context of boundary string field theory. For the case of pure tachyon only an array of kink-antikink is obtained. In the presence of electromagnetic coupling, all possible static codimension-one soliton solutions such as array of kink-antikink, single topological BPS kink, bounce, half kink, as well as nonBPS topological kink are found, and their properties including the interpretation as branes are analyzed in detail. Spectrum of the obtained kinks coincides with that of Dirac-Born-Infeld type effective theory.Comment: LaTex, 29 pages, 17 Figure

Holographic chiral magnetic spiral

We study the ground state of baryonic/axial matter at zero temperature chiral-symmetry broken phase under a large magnetic field, in the framework of holographic QCD by Sakai-Sugimoto. Our study is motivated by a recent proposal of chiral magnetic spiral phase that has been argued to be favored against previously studied phase of homogeneous distribution of axial/baryonic currents in terms of meson super-currents dictated by triangle anomalies in QCD. Our results provide an existence proof of chiral magnetic spiral in strong coupling regime via holography, at least for large axial chemical potentials, whereas we don't find the phenomenon in the case of purely baryonic chemical potential.Comment: 24 pages, 15 figure

A new rhynchocephalian from the late jurassic of Germany with a dentition that is unique amongst tetrapods.

Rhynchocephalians, the sister group of squamates (lizards and snakes), are only represented by the single genus Sphenodon today. This taxon is often considered to represent a very conservative lineage. However, rhynchocephalians were common during the late Triassic to latest Jurassic periods, but rapidly declined afterwards, which is generally attributed to their supposedly adaptive inferiority to squamates and/or Mesozoic mammals, which radiated at that time. New finds of Mesozoic rhynchocephalians can thus provide important new information on the evolutionary history of the group. A new fossil relative of Sphenodon from the latest Jurassic of southern Germany, Oenosaurus muehlheimensis gen. et sp. nov., presents a dentition that is unique amongst tetrapods. The dentition of this taxon consists of massive, continuously growing tooth plates, probably indicating a crushing dentition, thus representing a previously unknown trophic adaptation in rhynchocephalians. The evolution of the extraordinary dentition of Oenosaurus from the already highly specialized Zahnanlage generally present in derived rhynchocephalians demonstrates an unexpected evolutionary plasticity of these animals. Together with other lines of evidence, this seriously casts doubts on the assumption that rhynchocephalians are a conservative and adaptively inferior lineage. Furthermore, the new taxon underlines the high morphological and ecological diversity of rhynchocephalians in the latest Jurassic of Europe, just before the decline of this lineage on this continent. Thus, selection pressure by radiating squamates or Mesozoic mammals alone might not be sufficient to explain the demise of the clade in the Late Mesozoic, and climate change in the course of the fragmentation of the supercontinent of Pangaea might have played a major role

Holographic aspects of three dimensional QCD from string theory

We study two aspects of 3D QCD with massless fermions in a holographic set-up from string theory, based on D3/D7 branes; parity anomaly and baryons as baby Skyrmions. We first give a novel account of parity anomaly of 3D QCD with odd number of flavors from the IR holographic viewpoint by observing a subtle point in D7 brane embeddings with a given fixed UV theory. We also discuss its UV origin in terms of weakly coupled D-brane pictures. We then focus on the parity-symmetric case of even number of N_F flavors, and study baryons in the holographic model. We identify the monopoles of U(N_F) gauge theory dynamically broken down to U(N_F/2)x U(N_F/2) in the holographic 4 dimensional bulk as a holographic counter-part of 3D baby-Skyrmions for baryons in large N limit, and work out some details how the mapping goes. In particular, we show that the correct baryon charges emerge from the Witten effect with a space-varying theta angle.Comment: 33 pages, 10 figures; v2: references added with comments, typos corrected; v3: more references added; v4: holographic baryon profile and the analysis of its baryon charge is significantly revised, correcting errors in the previous discussio