1,396 research outputs found

    (E)-N′-(3,4-Dimethoxy­benzyl­idene)-2,4-dihydroxy­benzohydrazide methanol solvate

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    The title compound, C16H16N2O5·CH3OH, was obtained from a condensation reaction of 3,4-dimethoxy­benzaldehyde and 2,4-dihydroxy­benzohydrazide. The non-H atoms of the Schiff base mol­ecule are approximately coplanar (r.m.s. deviation = 0.043 Å) and the dihedral angle between the two benzene rings is 1.6 (1)°. The mol­ecule adopts an E configuration with respect to the C=N double bond. An intra­molecular O—H⋯O hydrogen bond is observed. The Schiff base and methanol mol­ecules are linked into a two-dimensional network parallel to (10) by inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds

    Surface exciton polaritons in individual Au nanoparticles in the far-ultraviolet spectral regime

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    All surface-excitation studies of Au in the past focused on the well-known 2.4 eV surface plasmon polariton in the visible spectral regime. The existence of surface exciton polaritons is believed to be pristine to the spectral regimes, showing strong excitonic absorptions. The presence of surface exciton polaritons in far-UV in Au (≥10 eV), where the optical and electronic properties of Au are dominated by broad interband transitions that display characters of rather weak and diffused excitonic oscillator strengths, is not expected and has never been discussed. Re-examining the reports of Yang and using electron energy-loss spectroscopy with a 2Å electron probe in aloof (optical near-field) setup and real-space energy-filtered imaging, we firmly establish the existence of surface exciton polaritons in individual Au nanoparticles in the far-UV spectral regime. These results indicate that surface exciton polaritons indeed can be excited in weak excitonic onsets in addition to their general believing for the sharp excitonic oscillations. Our experimental observations are further confirmed by the theoretical calculations of electron energy-loss spectra. The unmatched spatial resolution (2Å) of the electron spectroscopy technique enables an investigation of individual nanomaterials and their surface excitations in aloof setup. The surface exciton polaritons in individual Au nanoparticles thus represent an example of surface excitations of this type beyond the visible spectral regime and could stimulate further interests in surface exciton polaritons in various materials and applications in novel plasmonics and nanophotonics at high energies via manipulations of the associated surface near fields. © 2008 The American Physical Society.This work was supported by the National Science Council of Taiwan under Projects No. NSC94-2120-M-002-016 and No. NSC94-2119-M-002-025.Peer Reviewe

    NNAT and DIRAS3 genes are paternally expressed in pigs

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    Although expression and epigenetic differences of imprinted genes have been extensively characterised in man and the mouse, little is known on livestock species. In this study, the polymorphism-based approach was used to detect the imprinting status of NNAT and DIRAS3 genes in five heterozygous pigs (based on SNP) of Large White and Meishan F1 hybrids. The results show that both genes were paternally expressed in all the tested tissues (heart, liver, spleen, lung, kidney, stomach, small intestine, skeletal muscle, fat, uterus, ovary and pituitary). In addition, the NNAT gene had two transcripts in all tested tissues, which is consistent with its counterpart in man and cattle

    Adorym: A multi-platform generic x-ray image reconstruction framework based on automatic differentiation

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    We describe and demonstrate an optimization-based x-ray image reconstruction framework called Adorym. Our framework provides a generic forward model, allowing one code framework to be used for a wide range of imaging methods ranging from near-field holography to and fly-scan ptychographic tomography. By using automatic differentiation for optimization, Adorym has the flexibility to refine experimental parameters including probe positions, multiple hologram alignment, and object tilts. It is written with strong support for parallel processing, allowing large datasets to be processed on high-performance computing systems. We demonstrate its use on several experimental datasets to show improved image quality through parameter refinement

    KIN10 promotes stomatal development through stabilization of the SPEECHLESS transcription factor

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    Stomata are epidermal structures that modulate gas exchanges between plants and the atmosphere. The formation of stomata is regulated by multiple developmental and environmental signals, but how these signals are coordinated to control this process remains unclear. Here, we showed that the conserved energy sensor kinase SnRK1 promotes stomatal development under short-day photoperiod or in liquid culture conditions. Mutation of KIN10, the catalytic α-subunit of SnRK1, results in the decreased stomatal index; while overexpression of KIN10 significantly induces stomatal development. KIN10 displays the cell-type-specific subcellular location pattern. The nuclear-localized KIN10 proteins are highly enriched in the stomatal lineage cells to phosphorylate and stabilize SPEECHLESS, a master regulator of stomatal formation, thereby promoting stomatal development. Our work identifies a module links connecting the energy signaling and stomatal development and reveals that multiple regulatory mechanisms are in place for SnRK1 to modulate stomatal development in response to changing environments

    (E)-N′-(2,5-Dimethoxy­benzyl­idene)-2,4-dihydroxy­benzohydrazide

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    In the title compound, C16H16N2O5, the dihedral angle between the two benzene rings is 4.2 (2)° and an intra­molecular O—H⋯O hydrogen bond generates an S(6) ring. In the crystal, mol­ecules are linked into layers lying parallel to the bc plane by O—H⋯O and N—H⋯O hydrogen bonds

    Identification of a differentially expressed gene, ACL, between Meishan × Large White and Large White × Meishan F1 hybrids and their parents

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    ATP-citrate lyase (ACL), one of the lipogenic enzymes, catalyses the formation of acetyl-coenzyme A (CoA) involved in the synthesis of fatty acid and cholesterol. In pig, very little is known about the ACL gene. In this work, the mRNA differential display technique was used to analyse the differences in gene expression between Meishan and Large White pigs and the F1 hybrids of both direct and reciprocal crosses. Our results show that among the differentially expressed genes ACL is up-regulated in the backfat of the F1 hybrids. After cloning and analysing the fulllength cDNA and the 870 bp 5'-flanking sequence of the porcine ACL gene, a C/T mutation at position -97 bp upstream of the transcription site was detected. Luciferase activity detection showed that this mutation changed the transcriptional activity. In F1 hybrids, the heterozygous genotype CT was more frequent than the homozygous genotypes CC and TT. Real-time PCR analysis showed that in Meishan pigs, ACL mRNA expression was more abundant in individuals with genotype CT than in those with genotype CC or TT or in Large White pigs. These results indicate that the C/T mutation affects ACL mRNA expression, probably via the activator protein 2

    Controlling the Growth of the Skin Commensal Staphylococcus epidermidis Using d-Alanine Auxotrophy.

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    Using live microbes as therapeutic candidates is a strategy that has gained traction across multiple therapeutic areas. In the skin, commensal microorganisms play a crucial role in maintaining skin barrier function, homeostasis, and cutaneous immunity. Alterations of the homeostatic skin microbiome are associated with a number of skin diseases. Here, we present the design of an engineered commensal organism, Staphylococcus epidermidis, for use as a live biotherapeutic product (LBP) candidate for skin diseases. The development of novel bacterial strains whose growth can be controlled without the use of antibiotics or genetic elements conferring antibiotic resistance enables modulation of therapeutic exposure and improves safety. We therefore constructed an auxotrophic strain of S. epidermidis that requires exogenously supplied d-alanine. The S. epidermidis NRRL B-4268 Δalr1 Δalr2 Δdat strain (SEΔΔΔ) contains deletions of three biosynthetic genes: two alanine racemase genes, alr1 and alr2 (SE1674 and SE1079), and the d-alanine aminotransferase gene, dat (SE1423). These three deletions restricted growth in d-alanine-deficient medium, pooled human blood, and skin. In the presence of d-alanine, SEΔΔΔ colonized and increased expression of human β-defensin 2 in cultured human skin models in vitro. SEΔΔΔ showed a low propensity to revert to d-alanine prototrophy and did not form biofilms on plastic in vitro. These studies support the potential safety and utility of SEΔΔΔ as a live biotherapeutic strain whose growth can be controlled by d-alanine.IMPORTANCE The skin microbiome is rich in opportunities for novel therapeutics for skin diseases, and synthetic biology offers the advantage of providing novel functionality or therapeutic benefit to live biotherapeutic products. The development of novel bacterial strains whose growth can be controlled without the use of antibiotics or genetic elements conferring antibiotic resistance enables modulation of therapeutic exposure and improves safety. This study presents the design and in vitro evidence of a skin commensal whose growth can be controlled through d-alanine. The basis of this strain will support future clinical studies of this strain in humans
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