2,109 research outputs found

    Leptoquarks meet ε/ε\varepsilon'/\varepsilon and rare Kaon processes

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    We analyse for the first time the CP violating ratio ε/ε\varepsilon'/\varepsilon in KππK\to \pi\pi decays in leptoquark (LQ) models. Assuming a mass gap to the electroweak (EW) scale, the main mechanism for LQs to contribute to ε/ε\varepsilon'/\varepsilon is EW gauge-mixing of semi-leptonic into non-leptonic operators, which we treat in the Standard Model effective theory (SMEFT). We perform also the one-loop decoupling for scalar LQs, finding that in all models with both left-handed and right-handed LQ couplings box-diagrams generate numerically strongly enhanced EW-penguin operators Q8,8Q_{8,8'} already at the LQ scale. We then investigate correlations of ε/ε\varepsilon'/\varepsilon with rare Kaon processes (KLπ0ννˉK_L\to\pi^0\nu\bar\nu, K+π+ννˉK^+\to\pi^+\nu\bar\nu, KLπ0ˉK_L\to\pi^0\ell\bar\ell, KSμμˉK_S\to\mu\bar\mu, ΔMK\Delta M_K and εK\varepsilon_K) and find that even imposing only a moderate enhancement of (ε/ε)NP=5×104(\varepsilon'/\varepsilon)_{\rm NP} = 5 \times 10^{-4} to explain the current anomaly hinted by the Dual QCD approach and RBC-UKQCD lattice QCD calculations leads to conflicts with experimental upper bounds on rare Kaon processes. They exclude all LQ models with only a single coupling as an explanation of the ε/ε\varepsilon'/\varepsilon anomaly and put strong-to-serious constraints on parameter spaces of the remaining models. Future results on K+π+ννˉK^+\to\pi^+\nu\bar\nu from the NA62 collaboration, KLπ0ννˉK_L\to\pi^0\nu\bar\nu from the KOTO experiment and KSμμˉK_S\to\mu\bar\mu from LHCb will even stronger exhibit the difficulty of LQ models in explaining the measured ε/ε\varepsilon'/\varepsilon, in case the ε/ε\varepsilon'/\varepsilon anomaly will be confirmed by improved lattice QCD calculations. Hopefully also improved measurements of KLπ0ˉK_L\to\pi^0\ell\bar\ell decays will one day help in this context.Comment: 53 pages, 9 figures; v2: minor extensions, matches published version; v3: corrected eq.(B.10) and figure 2 (right plot U_1,L), conclusions not affecte

    The correct structures of the ortho-cyclized products in the cycloalkylations of 1-m-methoxybenzyl-4,4a,5,6,7,8-hexahydronaphthalen-2(3H)-one and 1-m-methoxybenzyl-octalins: X-ray structure determination of (±)-4-methoxy-9a-carbamorphinan-16-one

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    The previously assigned (ref.1) ortho-cycloalkylated product from the reaction of 1 and 2 respectively, with ortho-phosphosphoric acid and polyphosphoric acid, has been corrected to (±)-4-methoxy-9a-carbamorphinan-16-one (6) and the respective ether 7 by a single crystal X-ray structure determination of 6

    2,2′-Diazinodimethylidyne)di-o-phenyl­ene) dibenzoate

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    The title compound, C28H20N2O4, was synthesized by the reaction of 2-(hydrazonometh­yl)phenyl benzoate with iodine. The mol­ecule possesses a crystallographically imposed center of symmetry at the mid-point of the hydrazine N—N bond. The substituents at the ends of the C=N bonds adopt an E,E configuration. Inter­molecular C—H⋯π(arene) hydrogen bonds and aromatic π–π stacking inter­actions [centroid–centroid distance 3.900 (1) Å] link the mol­ecules into (100) sheets. In addition, there is an inter­molecular C—H⋯O hydrogen-bond inter­action

    The −675 4G/5G Polymorphism in Plasminogen Activator Inhibitor-1 Gene Is Associated with Risk of Asthma: A Meta-Analysis

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    BACKGROUND: A number of studies assessed the association of -675 4G/5G polymorphism in the promoter region of plasminogen activator inhibitor (PAI)-1 gene with asthma in different populations. However, most studies reported inconclusive results. A meta-analysis was conducted to investigate the association between polymorphism in the PAI-1 gene and asthma susceptibility. METHODS: Databases including Pubmed, EMBASE, HuGE Literature Finder, Wanfang Database, China National Knowledge Infrastructure (CNKI) and Weipu Database were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the dominant model, recessive model, codominant model, and additive model. RESULTS: Eight studies involving 1817 cases and 2327 controls were included. Overall, significant association between 4G/5G polymorphism and asthma susceptibility was observed for 4G4G+4G5G vs. 5G5G (OR = 1.56, 95% CI 1.12-2.18, P = 0.008), 4G/4G vs. 4G/5G+5G/5G (OR = 1.38, 95% CI 1.06-1.80, P = 0.02), 4G/4G vs. 5G/5G (OR = 1.80, 95% CI 1.17-2.76, P = 0.007), 4G/5G vs. 5G/5G (OR = 1.40, 95% CI 1.07-1.84, P = 0.02), and 4G vs. 5G (OR = 1.35, 95% CI 1.08-1.68, P = 0.008). CONCLUSIONS: This meta-analysis suggested that the -675 4G/5G polymorphism of PAI-1 gene was a risk factor of asthma

    A concentration-dependent endocytic trap and sink mechanism converts Bmper from an activator to an inhibitor of Bmp signaling

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    Bmper, which is orthologous to Drosophila melanogaster crossveinless 2, is a secreted factor that regulates Bmp activity in a tissue- and stage-dependent manner. Both pro- and anti-Bmp activities have been postulated for Bmper, although the molecular mechanisms through which Bmper affects Bmp signaling are unclear. In this paper, we demonstrate that as molar concentrations of Bmper exceed Bmp4, Bmper dynamically switches from an activator to an inhibitor of Bmp4 signaling. Inhibition of Bmp4 through a novel endocytic trap-and-sink mechanism leads to the efficient degradation of Bmper and Bmp4 by the lysosome. Bmper-mediated internalization of Bmp4 reduces the duration and magnitude of Bmp4-dependent Smad signaling. We also determined that Noggin and Gremlin, but not Chordin, trigger endocytosis of Bmps. This endocytic transport pathway expands the extracellular roles of selective Bmp modulators to include intracellular regulation. This dosage-dependent molecular switch resolves discordances among studies that examine how Bmper regulates Bmp activity and has broad implications for Bmp signal regulation by secreted mediators

    Biology and biotechnology of Trichoderma

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    Fungi of the genus Trichoderma are soilborne, green-spored ascomycetes that can be found all over the world. They have been studied with respect to various characteristics and applications and are known as successful colonizers of their habitats, efficiently fighting their competitors. Once established, they launch their potent degradative machinery for decomposition of the often heterogeneous substrate at hand. Therefore, distribution and phylogeny, defense mechanisms, beneficial as well as deleterious interaction with hosts, enzyme production and secretion, sexual development, and response to environmental conditions such as nutrients and light have been studied in great detail with many species of this genus, thus rendering Trichoderma one of the best studied fungi with the genome of three species currently available. Efficient biocontrol strains of the genus are being developed as promising biological fungicides, and their weaponry for this function also includes secondary metabolites with potential applications as novel antibiotics. The cellulases produced by Trichoderma reesei, the biotechnological workhorse of the genus, are important industrial products, especially with respect to production of second generation biofuels from cellulosic waste. Genetic engineering not only led to significant improvements in industrial processes but also to intriguing insights into the biology of these fungi and is now complemented by the availability of a sexual cycle in T. reesei/Hypocrea jecorina, which significantly facilitates both industrial and basic research. This review aims to give a broad overview on the qualities and versatility of the best studied Trichoderma species and to highlight intriguing findings as well as promising applications

    Yersinia enterocolitica Targets Cells of the Innate and Adaptive Immune System by Injection of Yops in a Mouse Infection Model

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    Yersinia enterocolitica (Ye) evades the immune system of the host by injection of Yersinia outer proteins (Yops) via a type three secretion system into host cells. In this study, a reporter system comprising a YopE-β-lactamase hybrid protein and a fluorescent staining sensitive to β-lactamase cleavage was used to track Yop injection in cell culture and in an experimental Ye mouse infection model. Experiments with GD25, GD25-β1A, and HeLa cells demonstrated that β1-integrins and RhoGTPases play a role for Yop injection. As demonstrated by infection of splenocyte suspensions in vitro, injection of Yops appears to occur randomly into all types of leukocytes. In contrast, upon infection of mice, Yop injection was detected in 13% of F4/80+, 11% of CD11c+, 7% of CD49b+, 5% of Gr1+ cells, 2.3% of CD19+, and 2.6% of CD3+ cells. Taking the different abundance of these cell types in the spleen into account, the highest total number of Yop-injected cells represents B cells, particularly CD19+CD21+CD23+ follicular B cells, followed by neutrophils, dendritic cells, and macrophages, suggesting a distinct cellular tropism of Ye. Yop-injected B cells displayed a significantly increased expression of CD69 compared to non-Yop-injected B cells, indicating activation of these cells by Ye. Infection of IFN-γR (receptor)- and TNFRp55-deficient mice resulted in increased numbers of Yop-injected spleen cells for yet unknown reasons. The YopE-β-lactamase hybrid protein reporter system provides new insights into the modulation of host cell and immune responses by Ye Yops

    Photochemically-produced SO2_2 in the atmosphere of WASP-39b

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    Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been detected in exoplanet atmospheres to date. Recent observations from the JWST Transiting Exoplanet Early Release Science Program found a spectral absorption feature at 4.05 μ\mum arising from SO2_2 in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ_J) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of \sim1100 K. The most plausible way of generating SO2_2 in such an atmosphere is through photochemical processes. Here we show that the SO2_2 distribution computed by a suite of photochemical models robustly explains the 4.05 μ\mum spectral feature identified by JWST transmission observations with NIRSpec PRISM (2.7σ\sigma) and G395H (4.5σ\sigma). SO2_2 is produced by successive oxidation of sulphur radicals freed when hydrogen sulphide (H2_2S) is destroyed. The sensitivity of the SO2_2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of \sim10×\times solar. We further point out that SO2_2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations.Comment: 39 pages, 14 figures, accepted to be published in Natur

    Photochemically produced SO2 in the atmosphere of WASP-39b

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    Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability1. However, no unambiguous photochemical products have been detected in exoplanet atmospheres so far. Recent observations from the JWST Transiting Exoplanet Community Early Release Science Program2,3 found a spectral absorption feature at 4.05 μm arising from sulfur dioxide (SO2) in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of around 1,100 K (ref. 4). The most plausible way of generating SO2 in such an atmosphere is through photochemical processes5,6. Here we show that the SO2 distribution computed by a suite of photochemical models robustly explains the 4.05-μm spectral feature identified by JWST transmission observations7 with NIRSpec PRISM (2.7σ)8 and G395H (4.5σ)9. SO2 is produced by successive oxidation of sulfur radicals freed when hydrogen sulfide (H2S) is destroyed. The sensitivity of the SO2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of about 10× solar. We further point out that SO2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations
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