Very Long Baseline Interferometry observations at 86 GHz reveal an almost hollow jet in M87 with a forked morphology. The detailed analysis presented here indicates that the spectral luminosity of ...the central spine of the jet in M87 is a few percent of that of the surrounding hollow jet 200–400
μ
as from the central black hole. Furthermore, recent jet models indicate that a hollow “tubular” jet can explain a wide range of plausible broadband spectra originating from jetted plasma located within ~30
μ
as of the central black hole, including the 230 GHz correlated flux detected by the Event Horizon Telescope. Most importantly, these hollow jets from the inner accretion flow have an intrinsic power capable of energizing the global jet out to kiloparsec scales. Thus motivated, this paper considers new models of the event horizon magnetosphere (EHM) in low luminosity accretion systems. Contrary to some models, the spine is not an invisible powerful jet. It is an intrinsically weak jet. In the new EHM solution, the accreted poloidal magnetic flux is weak and the background photon field is weak. It is shown how this accretion scenario naturally results in the dissipation of the accreted poloidal magnetic flux in the EHM not the accumulation of poloidal flux required for a powerful jet. The new solution indicates less large scale poloidal magnetic flux (and jet power) in the EHM than in the surrounding accretion flow and cannot support significant EHM driven jets.
The Galactic center supermassive black hole Sagittarius A* (Sgr A*) is one of the most promising targets to study the dynamics of black hole accretion and outflow via direct imaging with very long ...baseline interferometry (VLBI). At 3.5 mm (86 GHz), the emission from Sgr A* is resolvable with the Global Millimeter VLBI Array (GMVA). We present the first observations of Sgr A* with the phased Atacama Large Millimeter/submillimeter Array (ALMA) joining the GMVA. Our observations achieve an angular resolution of ∼87 as, improving upon previous experiments by a factor of two. We reconstruct a first image of the unscattered source structure of Sgr A* at 3.5 mm, mitigating the effects of interstellar scattering. The unscattered source has a major-axis size of 120 34 as (12 3.4 Schwarzschild radii) and a symmetrical morphology (axial ratio of ), which is further supported by closure phases consistent with zero within 3 . We show that multiple disk-dominated models of Sgr A* match our observational constraints, while the two jet-dominated models considered are constrained to small viewing angles. Our long-baseline detections to ALMA also provide new constraints on the scattering of Sgr A*, and we show that refractive scattering effects are likely to be weak for images of Sgr A* at 1.3 mm with the Event Horizon Telescope. Our results provide the most stringent constraints to date for the intrinsic morphology and refractive scattering of Sgr A*, demonstrating the exceptional contribution of ALMA to millimeter VLBI.
Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystem disorder caused by expansion of the CTG triplet repeats in the 3′ untranslated region of dystrophia myotonica protein kinase ...(DMPK). It leads to transcription of toxic RNA containing expanded CUG repeats (CUGexp). Splicing factors such as MBNL1 are sequestered by CUGexp and it interferes with normal splicing programs that are essential for various cellular functions. Pentatricopeptide repeat (PPR) proteins, originally found in plants, regulate organelle RNAs by binding in a sequence-specific manner. In this study, we designed a series of PPR proteins that specifically bind to the hexamer of CUG-repeat RNA (CUG-PPRs) and showed that they selectively bound to the CUG hexamer in vitro and improved typical molecular abnormalities caused by CUGexp in murine DM1 model cells. Finally, we demonstrated that a single systemic administration of a recombinant adeno-associated virus (AAV9) with an expression cassette of CUG-PPR1 protein showed a long-term therapeutic efficacy in DM1 model mice in a correlation with global restoration of abnormal splicing activity. We would like also to present at the session that CUG-PPR1 does not reduce neither DMPK mRNA nor the protein levels in patient-derived cells, unlike nucleic acid-based modalities. These results suggest that systemic delivery of CUG-specific PPR molecules by AAV9 might be an effective approach for the treatment of DM1. Furthermore, this study implies a potential of PPR molecules as a new therapeutic modality that can target pathogenic RNA-mediated diseases.
The change structure and composition of molybdenum nitride catalysts with cooling in a stream of ammonia or helium gas after NH3 treating was determined using temperature-programmed reduction (TPR) ...and X-ray powder diffraction analyses. The relationship between the molybdenum species and the catalytic activities of the molybdenum nitride catalysts for the hydrodenitrogenation (HDN) of carbazole was discussed. MoO2, γ-Mo2N, and Mo metal were mainly formed during the temperature-programmed reaction of MoO3 with ammonia at 773, 973, and 1173 K, respectively. During the TPR experiment, a portion of the adsorbed NHx (x=0–3) species caused further nitriding of the catalyst at higher temperatures. It was found that nitrogen desorption during TPR could be assigned to four types of nitrogen species: (1) NHx adsorbed on MoO2, (2) NHx adsorbed on γ-Mo2N, (3) N2 during the transformation of γ-Mo2N to β-Mo2N0.78, and (4) N2 during the reduction of β-Mo2N0.78 to molybdenum metal. Purging the NH3-treated catalyst with helium at 973 K not only removed the adsorbed NHx and diffused nitrogen but also altered the structure of the molybdenum compounds, i.e., from γ-Mo2N to β-Mo2N0.78. During the HDN of carbazole, γ-Mo2N was the most active, followed by β-Mo2N0.78 for C–N hydrogenolysis, while molybdenum metal had the highest activity for hydrogenation. NH3-treated MoO2 was much less active for both C–N hydrogenolysis and hydrogenation during carbazole HDN. From these results, the C–N hydrogenolysis sites were most likely located on small nitrogen deficient particles and crystallites of the molybdenum nitrides. The hydrogenation sites were located on the surface grain boundary of molybdenum metals.
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