The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium
, which is assumed to dominate the total extragalactic dispersion. ...Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs
, in at least one case there is evidence for an extreme magneto-ionic local environment
and a compact persistent radio source
. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately Formula: see text parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies
, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications.
The search continues for nickel oxide-based materials with electronic properties similar to cuprate high-temperature superconductors
. The recent discovery of superconductivity in the doped ...infinite-layer nickelate NdNiO
(refs.
) has strengthened these efforts. Here, we use X-ray spectroscopy and density functional theory to show that the electronic structure of LaNiO
and NdNiO
, while similar to the cuprates, includes significant distinctions. Unlike cuprates, the rare-earth spacer layer in the infinite-layer nickelate supports a weakly interacting three-dimensional 5d metallic state, which hybridizes with a quasi-two-dimensional, strongly correlated state with Formula: see text symmetry in the NiO
layers. Thus, the infinite-layer nickelate can be regarded as a sibling of the rare-earth intermetallics
, which are well known for heavy fermion behaviour, where the NiO
correlated layers play an analogous role to the 4f states in rare-earth heavy fermion compounds. This Kondo- or Anderson-lattice-like 'oxide-intermetallic' replaces the Mott insulator as the reference state from which superconductivity emerges upon doping.
The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and ...transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.
Abstract
Discovery of pulsars is one of the main goals for large radio telescopes. The Five-hundred-meter Aperture Spherical radio Telescope (FAST), that incorporates an L-band 19-beam receiver with ...a system temperature of about 20 K, is the most sensitive radio telescope utilized for discovering pulsars. We designed the
snapshot
observation mode for a FAST key science project, the Galactic Plane Pulsar Snapshot (GPPS) survey, in which every four nearby pointings can observe
a cover
of a sky patch of 0.1575 square degrees through beam-switching of the L-band 19-beam receiver. The integration time for each pointing is 300 seconds so that the GPPS observations for a cover can be made in 21 minutes. The goal of the GPPS survey is to discover pulsars within the Galactic latitude of ± 10° from the Galactic plane, and the highest priority is given to the inner Galaxy within ± 5°. Up to now, the GPPS survey has discovered 201 pulsars, including currently the faintest pulsars which cannot be detected by other telescopes, pulsars with extremely high dispersion measures (DMs) which challenge the currently widely used models for the Galactic electron density distribution, pulsars coincident with supernova remnants, 40 millisecond pulsars, 16 binary pulsars, some nulling and mode-changing pulsars and rotating radio transients (RRATs). The follow-up observations for confirmation of new pulsars have polarization-signals recorded for polarization profiles of the pulsars. Re-detection of previously known pulsars in the survey data also leads to significant improvements in parameters for 64 pulsars. The GPPS survey discoveries are published and will be updated at
http://zmtt.bao.ac.cn/GPPS/
.
Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa ...phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PIN1 in T. annulata (TaPIN1) that is secreted into the host cell and modulates oncogenic signalling pathways. Here we show that TaPIN1 is a bona fide prolyl isomerase and that it interacts with the host ubiquitin ligase FBW7, leading to its degradation and subsequent stabilization of c-JUN, which promotes transformation. We performed in vitro and in silico analysis and in vivo zebrafish xenograft experiments to demonstrate that TaPIN1 is directly inhibited by the anti-parasite drug buparvaquone (and other known PIN1 inhibitors) and is mutated in a drug-resistant strain. Prolyl isomerization is thus a conserved mechanism that is important in cancer and is used by Theileria parasites to manipulate host oncogenic signalling.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT We report the discovery of EPIC 201702477b, a transiting brown dwarf in a long period (40.73691 0.00037 day) and eccentric (e = 0.2281 0.0026) orbit. This system was initially reported as a ...planetary candidate based on two transit events seen in K2 Campaign 1 photometry and later validated as an exoplanet candidate. We confirm the transit and refine the ephemeris with two subsequent ground-based detections of the transit using the Las Cumbres Observatory Global Telescope 1 m telescope network. We rule out any transit timing variations above the level of ∼30 s. Using high precision radial velocity measurements from HARPS and SOPHIE we identify the transiting companion as a brown dwarf with a mass, radius, and bulk density of 66.9 1.7 MJ, 0.757 0.065 RJ, and 191 51 g cm−3 respectively. EPIC 201702477b is the smallest radius brown dwarf yet discovered, with a mass just below the H-burning limit. It has the highest density of any planet, substellar mass object, or main-sequence star discovered so far. We find evidence in the set of known transiting brown dwarfs for two populations of objects-high mass brown dwarfs and low mass brown dwarfs. The higher-mass population have radii in very close agreement to theoretical models, and show a lower-mass limit around 60 MJ. This may be the signature of mass-dependent ejection of systems during the formation process.
Patients with heart failure with preserved ejection fraction were assigned to receive sacubitril–valsartan or valsartan. At a median of 35 months, there was no significant between-group difference in ...the composite outcome of total hospitalizations for heart failure or death from cardiovascular causes.
Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of ...characterization techniques, and simulations, we observe that in PbTiO
/SrTiO
superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a
/a
phase. At room temperature, the coexisting vortex and ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our findings suggest new cross-coupled functionalities.
Background
Various minimally invasive approaches have been described for infected necrotizing pancreatitis. This article describes a modified minimal‐access retroperitoneal pancreatic necrosectomy ...(MARPN) procedure assisted by gas insufflation.
Methods
This retrospective, observational study documented patients who had undergone a step‐up MARPN between 1 January 2010 and 31 December 2016. A minimum follow‐up of 1 year was required for inclusion. The step‐up approach involved percutaneous catheter drainage followed by the modified MARPN and necrosectomy. If more than one access site was needed it was categorized as complex MARPN.
Results
Of 212 patients with infected necrotizing pancreatitis, 164 (77·4 per cent) underwent a step‐up approach. The median number of percutaneous catheter drains and MARPN procedures was 3 (range 1–7) and 1 (1–6) respectively. Ninety patients (54·9 per cent) underwent complex MARPN. For residual necrosis after MARPN, three patients (1·8 per cent) underwent sinus tract gastroscopy, and 11 (6·7 per cent) had sinography combined with a tube change. However, operations in 13 patients (7·9 per cent) required conversion to open surgery. Postoperative complications developed in 103 patients (62·8 per cent). The mortality rate was 6·1 per cent (10 deaths).
Conclusion
A step‐up approach using a modified MARPN for infected necrotizing pancreatitis is a reasonable option.
Antecedentes
Los procedimientos mínimamente invasivos se han convertido en los más frecuentes para el tratamiento de necrosis pancreáticas infectadas. El objetivo de este estudio fue presentar un procedimiento de necrosectomía pancreática retroperitoneal de acceso mínimo (minimal‐access retroperitoneal pancreatic necrosectomy, MARPN) modificado y asistido mediante insuflación de gases, así como evaluar su seguridad y eficacia.
Métodos
Se realizó un análisis retrospectivo y observacional de los datos de un hospital desde el 1 de enero de 2010 hasta el 31 de diciembre de 2016. Se incluyeron en el análisis todos los pacientes en los que realizó un abordaje por etapas, que consistía en el drenaje percutáneo mediante la colocación de un catéter seguido de un procedimiento MARPN modificado, en los que se dispusiese de un seguimiento postoperatorio mínimo de 1 año. El MARPN en el lado derecho y la necrosectomía realizada a través de más de un acceso se clasificaron como MARPN complejo. Se evaluaron los resultados radiológicos y quirúrgicos.
Resultados
De 212 pacientes con necrosis pancreática infectada, en 164 (77,4%) se realizó un abordaje por etapas. La mediana del número de drenajes percutáneos y procedimientos MARPN fue 3 (rango, 1‐7) y 1 (rango, 1‐6), respectivamente. En 90 pacientes (54,9%) se realizó un MARPN complejo. Para la exéresis de necrosis residual después de un MARPN, en 3 pacientes (1,8%) se realizó mediante gastroscopia y en 11 pacientes (6,7%) con un recambio de drenaje bajo control radiológico. En 13 pacientes (7,9%) fue necesaria la reconversión a cirugía abierta. Hubo complicaciones postoperatorias en 103 pacientes (62,8%). La tasa de mortalidad fue del 6,1% (n = 10).
Conclusión
El abordaje por etapas con un MARPN modificado es seguro y efectivo en el tratamiento de la necrosis pancreática infectada.
Minimally invasive approaches have been used increasingly in the management of infected necrotizing pancreatitis. This study presents a modified minimal‐access retroperitoneal pancreatic necrosectomy procedure assisted by carbon dioxide insufflation, instead of saline. A clear field of view without necrotic debris floating in saline makes the technique safe and efficient.
High degree of success
VIDEO
Presented in part to the Joint Congress of the Sixth Biennial Congress of the Asian–Pacific Hepato‐Pancreato‐Biliary Association and the 29th Meeting of the Japanese Society of Hepato‐Biliary‐Pancreatic Surgery, Yokohama, Japan, June 2017
Abstract
We report the joint WASP/KELT discovery of WASP-167b/KELT-13b, a transiting hot Jupiter with a 2.02-d orbit around a V = 10.5, F1V star with Fe/H = 0.1 ± 0.1. The 1.5 R
Jup planet was ...confirmed by Doppler tomography of the stellar line profiles during transit. We place a limit of <8 M
Jup on its mass. The planet is in a retrograde orbit with a sky-projected spin–orbit angle of λ = −165° ± 5°. This is in agreement with the known tendency for orbits around hotter stars to be more likely to be misaligned. WASP-167/KELT-13 is one of the few systems where the stellar rotation period is less than the planetary orbital period. We find evidence of non-radial stellar pulsations in the host star, making it a δ-Scuti or γ-Dor variable. The similarity to WASP-33, a previously known hot-Jupiter host with pulsations, adds to the suggestion that close-in planets might be able to excite stellar pulsations.
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