Flavoured axions in the tail of Bq_{q} → μ+^{+} μ−^{-} and B → γ∗^{*} form factors

We discuss how LHC di-muon data collected to study B$_{q}$ → μμ can be used to constrain light particles with flavour-violating couplings to b-quarks. Focussing on the case of a flavoured QCD axion, a, we compute the decay rates for B$_{q}$ → μμa and the SM background process Bq → μμγ near the kinematic endpoint. These rates depend on non-perturbative Bq → γ($^{*}$) form factors with on- or off-shell photons. The off-shell form factors — relevant for generic searches for beyond-the-SM particles — are discussed in full generality and computed with QCD sum rules for the first time. This includes an extension to the low-lying resonance region using a multiple subtracted dispersion relation. With these results, we analyse available LHCb data to obtain the sensitivity on B$_{q}$ → μμa at present and future runs. We find that the full LHCb dataset alone will allow to probe axion-coupling scales of the order of 10$^{6}$ GeV for both b → d and b → s transitions. As a spin-off application of the off-shell form factors we further analyse the case of light, Beyond the Standard Model, vectors

Different Outcomes of Experimental Hepatitis E Virus Infection in Diverse Mouse Strains, Wistar Rats, and Rabbits

Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but autochthonous cases of zoonotic genotype 3 (HEV-3) infection also occur in industrialized countries. In contrast to swine, rats, and rabbits, natural HEV infections in mice have not yet been demonstrated. The pig represents a well-established large animal model for HEV-3 infection, but a suitable small animal model mimicking natural HEV-3 infection is currently missing. Therefore, we experimentally inoculated C57BL/6 mice (wild-type, IFNAR−/−, CD4−/−, CD8−/−) and BALB/c nude (nu/nu) mice, Wistar rats, and European rabbits with a wild boar-derived HEV-3 strain and monitored virus replication and shedding, as well as humoral immune responses. HEV RNA and anti-HEV antibodies were detected in one and two out of eight of the rats and all rabbits inoculated, respectively, but not in any of the mouse strains tested. Remarkably, immunosuppressive dexamethasone treatment of rats did not enhance their susceptibility to HEV infection. In rabbits, immunization with recombinant HEV-3 and ratHEV capsid proteins induced protection against HEV-3 challenge. In conclusion, the rabbit model for HEV-3 infection may serve as a suitable alternative to the non-human primate and swine models, and as an appropriate basis for vaccine evaluation studies

Tolerance induced via TLR2 and TLR4 in human dendritic cells: role of IRAK-1

<p>Abstract</p> <p>Background</p> <p>While dendritic cells (DCs) can induce tolerance in T cells, little is known about tolerance induction in DCs themselves. We have analysed tolerance induced in human <it>in-vitro </it>generated DCs by repeated stimulation with ligands for TLR4 and TLR2.</p> <p>Results</p> <p>DCs stimulated with the TLR4 ligand LPS did show a rapid and pronounced expression of TNF mRNA and protein. When DCs were pre-cultured for 2 days with 5 ng LPS/ml then the subsequent response to stimulation with a high dose of LPS (500 ng/ml) was strongly reduced for both TNF mRNA and protein. At the promoter level there was a reduced transactivation by the -1173 bp TNF promoter and by a construct with a tetrameric NF-κB motif. Within the signalling cascade leading to NF-κB activation we found an ablation of the IRAK-1 adaptor protein in LPS-tolerant DCs. Pre-culture of DCs with the TLR2 ligand Pam3Cys also led to tolerance with respect to TNF gene expression and IRAK-1 protein was ablated in such tolerant cells as well, while IRAK-4 protein levels were unchanged.</p> <p>Conclusion</p> <p>These data show that TLR-ligands can render DCs tolerant with respect to TNF gene expression by a mechanism that likely involves blockade of signal transduction at the level of IRAK-1.</p

2-(4-Fluoro­phen­yl)-N-{4-[6-(4-fluoro­phen­yl)-2,3-dihydro­imidazo[2,1-b][1,3]thia­zol-5-yl]pyridin-2-yl}acetamide

In the crystal structure of the title compound, C24H18F2N4OS, the imidazole system makes dihedral angles of 34.3 (1) and 43.9 (1)°, respectively, with the directly attached 4-fluoro­phenyl and pyridine rings. The crystal structure is stabilized by inter­molecular N—H⋯N hydrogen bonding and by an intra­molecular C—H⋯O hydrogen inter­action. The F atom of the 2-(4-fluoro­phen­yl) group is disordered over two positions with site-occupancy factors of 0.75 and 0.25

Probing flavoured Axions in the Tail of Bq→μ+μ−B_q \to \mu^+\mu^-

We discuss how LHC di-muon data collected to study $B_q \to \mu\mu$ can be used to constrain light particles with flavour-violating couplings to $b$-quarks. Focussing on the case of a flavoured QCD axion, $a$, we compute the decay rates for $B_q \to \mu \mu a$ and the SM background process $B_q \to \mu \mu \gamma$ near the kinematic endpoint. These rates depend on non-perturbative $B_q \to \gamma^{(*)}$ form factors with on- or off-shell photons. The off-shell form factors -- relevant for generic searches for beyond-the-SM particles -- are discussed in full generality and computed with QCD sum rules for the first time. With these results, we analyse available LHCb data to obtain the sensitivity on $B_q \to \mu \mu a$ at present and future runs. We find that the full LHCb dataset alone will allow to probe axion-coupling scales of the order of $10^6$ GeV for both $b\to d$ and $b \to s$ transitions.Comment: 37 pages, 6 figures, version to appear in JHEP, added multiple subtracted dispersion relation to extend in resonance region including ancillary Mathematica notebook with Form Factor

Ultrafine carbon particles down-regulate CYP1B1 expression in human monocytes

Cytochrome P450 monoxygenases play an important role in the defence against inhaled toxic compounds and in metabolizing a wide range of xenobiotics and environmental contaminants. In ambient aerosol the ultrafine particle fraction which penetrates deeply into the lungs is considered to be a major factor for adverse health effects. The cells mainly affected by inhaled particles are lung epithelial cells and cells of the monocyte/macrophage lineage. RESULTS: In this study we have analyzed the effect of a mixture of fine TiO2 and ultrafine carbon black Printex 90 particles (P90) on the expression of cytochrome P450 1B1 (CYP1B1) in human monocytes, macrophages, bronchial epithelial cells and epithelial cell lines. CYP1B1 expression is strongly down-regulated by P90 in monocytes with a maximum after P90 treatment for 3 h while fine and ultrafine TiO2 had no effect. CYP1B1 was down-regulated up to 130-fold and in addition CYP1A1 mRNA was decreased 13-fold. In vitro generated monocyte-derived macrophages (MDM), epithelial cell lines, and primary bronchial epithelial cells also showed reduced CYP1B1 mRNA levels. Benzo[a]pyrene (BaP) is inducing CYB1B1 but ultrafine P90 can still down-regulate gene expression at 0.1 muM of BaP. The P90-induced reduction of CYP1B1 was also demonstrated at the protein level using Western blot analysis. CONCLUSION: These data suggest that the P90-induced reduction of CYP gene expression may interfere with the activation and/or detoxification capabilities of inhaled toxic compounds

Molecular investigations on a chimeric strain of Staphylococcus aureus sequence type 80

A PVL-positive, methicillin-susceptible Staphylococcus aureus was cultured from pus from cervical lymphadenitis of a patient of East-African origin. Microarray hybridisation assigned the isolate to clonal complex (CC) 80 but revealed unusual features, including the presence of the ORF-CM14 enterotoxin homologue and of an ACME-III element as well as the absence of etD and edinB. The isolate was subjected to both, Illumina and Nanopore sequencing allowing characterisation of deviating regions within the strain´s genome. Atypical features of this strain were attributable to the presence of two genomic regions that originated from other S. aureus lineages and that comprised, respectively, 3% and 1.4% of the genome. One deviating region extended from walJ to sirB. It comprised ORF-CM14 and the ACME-III element. A homologous but larger fragment was also found in an atypical S. aureus CC1/ST567 strain whose lineage might have served as donor of this genomic region. This region itself is a chimera comprising fragments from CC1 as well as fragments of unknown origin. The other deviating region comprised the region from htsB to ecfA2, i.e., another 3% of the genome. It was very similar to CC1 sequences. Either this suggests an incorporation of CC1 DNA into the study strain, or alternatively a recombination event affecting “canonical” CC80. Thus, the study strain bears witness of several recombination events affecting supposedly core genomic genes. Although the exact mechanism is not yet clear, such chimerism seems to be an additional pathway in the evolution of S. aureus. This could facilitate also a transmission of virulence and resistance factors and therefore offer an additional evolutionary advantage

Exchange and Correlation Kernels at the Resonance Frequency -- Implications for Excitation Energies in Density-Functional Theory

Specific matrix elements of exchange and correlation kernels in time-dependent density-functional theory are computed. The knowledge of these matrix elements not only constraints approximate time-dependent functionals, but also allows to link different practical approaches to excited states, either based on density-functional theory, or on many-body perturbation theory, despite the approximations that have been performed to derive them.Comment: Submitted to Phys. Rev. Lett. (February 4, 1999). Other related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm