394 research outputs found

    The K2-ESPRINT Project. I. Discovery of the Disintegrating Rocky Planet K2-22b with a Cometary Head and Leading Tail

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    We present the discovery of a transiting exoplanet candidate in the K2 Field-1 with an orbital period of 9.1457 hr: K2-22b. The highly variable transit depths, ranging from \sim0\% to 1.3\%, are suggestive of a planet that is disintegrating via the emission of dusty effluents. We characterize the host star as an M-dwarf with Teff3800T_{\rm eff} \simeq 3800 K. We have obtained ground-based transit measurements with several 1-m class telescopes and with the GTC. These observations (1) improve the transit ephemeris; (2) confirm the variable nature of the transit depths; (3) indicate variations in the transit shapes; and (4) demonstrate clearly that at least on one occasion the transit depths were significantly wavelength dependent. The latter three effects tend to indicate extinction of starlight by dust rather than by any combination of solid bodies. The K2 observations yield a folded light curve with lower time resolution but with substantially better statistical precision compared with the ground-based observations. We detect a significant "bump" just after the transit egress, and a less significant bump just prior to transit ingress. We interpret these bumps in the context of a planet that is not only likely streaming a dust tail behind it, but also has a more prominent leading dust trail that precedes it. This effect is modeled in terms of dust grains that can escape to beyond the planet's Hill sphere and effectively undergo `Roche lobe overflow,' even though the planet's surface is likely underfilling its Roche lobe by a factor of 2.Comment: 22 pages, 16 figures. Final version accepted to Ap

    Annual variation in the levels of transcripts of sex-specific genes in the mantle of the common mussel, Mytilus edulis

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    Mytilus species are used as sentinels for the assessment of environmental health but sex or stage in the reproduction cycle is rarely considered even though both parameters are likely to influence responses to pollution. We have validated the use of a qPCR assay for sex identification and related the levels of transcripts to the reproductive cycle. A temporal study of mantle of Mytilus edulis found transcripts of male-specific vitelline coat lysin (VCL) and female-specific vitelline envelope receptor for lysin (VERL) could identify sex over a complete year. The levels of VCL/VERL were proportional to the numbers of sperm/ova and are indicative of the stage of the reproductive cycle. Maximal levels of VCL and VERL were found in February 2009 declining to minima between July - August before increasing and re-attaining a peak in February 2010. Water temperature may influence these transitions since they coincide with minimal water temperature in February and maximal temperature in August. An identical pattern of variation was found for a cryptic female-specific transcript (H5) but a very different pattern was observed for oestrogen receptor 2 (ER2). ER2 varied in a sex-specific way with male > female for most of the cycle, with a female maxima in July and a male maxima in December. Using artificially spawned animals, the transcripts for VCL, VERL and H5 were shown to be present in gametes and thus their disappearance from mantle is indicative of spawning. VCL and VERL are present at equivalent levels in February and July-August but during gametogenesis (August to January) and spawning (March to June) VCL is present at lower relative amounts than VERL. This may indicate sex-specific control mechanisms for these processes and highlight a potential pressure point leading to reduced reproductive output if environmental factors cause asynchrony to gamete maturation or release

    Crystallographic coincidence of two bridging species in a dinuclear CoIII ethynyl­benzene complex

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    In the title compound, trans,trans-[μ-(m-phenyl­ene)bis­(ethyne-1,2-di­yl)]bis­[chlorido(1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)cobalt(III)]–trans,trans-[μ-(5-bromo-m-phenyl­ene)bis­(ethyne-1,2-di­yl)]bis­[chlorido(1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)cobalt(III)]–tetra­phenyl­borate–acetone (0.88/0.12/2/4), [Co2(C12H4)Cl2(C10H24N4)2]0.88[Co2(C10H3Br)Cl2(C10H24N4)2]0.12(C24H20B)2·4C3H6O, with the exception of the acetyl­ene and bromine groups, all atomic postitions are the same in the two compounds and are modeled at full occupancy. The CoIII ions are six-coordinate with acetyl­ide and chloride ligands bound to the axial sites and the N atoms from the cyclam rings coordinated at the equatorial positions. N—H⋯O and N—H⋯Cl hydrogen-bonding interactions help to consolidate the crystal packing

    Early treatment with a sodium-glucose co-transporter 2 inhibitor in high-risk patients with acute heart failure:Rationale for and design of the EMPA-AHF trial

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    Aims: The aim of the EMPA-AHF trial is to clarify whether early initiation of a sodium-glucose co-transporter 2 inhibitor before clinical stabilization is safe and beneficial for patients with acute heart failure (AHF) who are at a high risk of adverse events. Methods: The EMPA-AHF trial is a randomized, double-blind, placebo-controlled, multicentre trial examining the efficacy and safety of early initiation of empagliflozin (10 mg once daily). In total, 500 patients admitted for AHF will be randomized 1:1 to either empagliflozin 10 mg daily or placebo at 47 sites in Japan. Study entry requires hospitalization for AHF with dyspnoea, signs of volume overload, elevated natriuretic peptide, and at least one of the following criteria: estimated glomerular filtration rate &lt;60 mL/min/1.73 m2; already taking ≥40 mg of furosemide daily before hospitalization; and urine output of &lt;300 mL within 2 hours after an adequate dose of intravenous furosemide. Patients will be randomized within 12 hours of hospital presentation, with treatment continued up to 90 days. The primary outcome is the clinical benefit of empagliflozin on the win ratio for a hierarchical composite endpoint consisting of death within 90 days, heart failure rehospitalization within 90 days, worsening heart failure during hospitalization, and urine output within 48 hours after treatment initiation. Conclusion: The EMPA-AHF trial is the first to evaluate the efficacy and safety of early initiation of empagliflozin in patients with AHF considered to be at high risk under conventional treatment.</p

    Early treatment with a sodium-glucose co-transporter 2 inhibitor in high-risk patients with acute heart failure:Rationale for and design of the EMPA-AHF trial

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    Aims: The aim of the EMPA-AHF trial is to clarify whether early initiation of a sodium-glucose co-transporter 2 inhibitor before clinical stabilization is safe and beneficial for patients with acute heart failure (AHF) who are at a high risk of adverse events. Methods: The EMPA-AHF trial is a randomized, double-blind, placebo-controlled, multicentre trial examining the efficacy and safety of early initiation of empagliflozin (10 mg once daily). In total, 500 patients admitted for AHF will be randomized 1:1 to either empagliflozin 10 mg daily or placebo at 47 sites in Japan. Study entry requires hospitalization for AHF with dyspnoea, signs of volume overload, elevated natriuretic peptide, and at least one of the following criteria: estimated glomerular filtration rate &lt;60 mL/min/1.73 m2; already taking ≥40 mg of furosemide daily before hospitalization; and urine output of &lt;300 mL within 2 hours after an adequate dose of intravenous furosemide. Patients will be randomized within 12 hours of hospital presentation, with treatment continued up to 90 days. The primary outcome is the clinical benefit of empagliflozin on the win ratio for a hierarchical composite endpoint consisting of death within 90 days, heart failure rehospitalization within 90 days, worsening heart failure during hospitalization, and urine output within 48 hours after treatment initiation. Conclusion: The EMPA-AHF trial is the first to evaluate the efficacy and safety of early initiation of empagliflozin in patients with AHF considered to be at high risk under conventional treatment.</p

    Expression of nm23-H1 gene product in esophageal squamous cell carcinoma and its association with vessel invasion and survival

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    BACKGROUND: We assessed the nm23-H1 gene product expression and its relationship with lymphatic and blood vessel invasion in patients with esophageal squamous cell carcinoma. METHODS: Formalin-fixed and paraffin-embedded tissue sections from 45 patients who were treated surgically were used in this study. Pathologists graded lymphatic and blood vessel invasion in each of the tissue samples. Expression of nm23-Hl gene product was determined using a specific monoclonal antibody. RESULTS: Expression of nm23-H1 gene product was present in 17 (37.8%) cases. We found an inverse correlation between nm23-H1 gene product expression and lymphatic vessel invasion, whereas no correlation between nm23-H1 gene product expression and blood vessel invasion. Overall survival rate was not different between nm23-H1 gene product positive and negative patients (p = 0.21). However, reduced expression of nm23-H1 gene product was associated with shorter overall survival in patients with involved lymph nodes (p < 0.05), but not in patients without involved lymph nodes (p = 0.87). CONCLUSIONS: In patients with esophageal squamous cell carcinoma, there appears to be an inverse relationship between nm23-H1 gene product expression and lymphatic vessel invasion. Furthermore, nm23-H1 gene product expression might be a prognostic marker in patients with involved lymph nodes. Our data does not demonstrate any correlation between nm23-H1 gene product expression and blood vessel invasion
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