Given its peak luminosity and early-time spectra, ASASSN-15lh was classified as the most luminous supernova ever discovered. Here, we report a UV rebrightening of ASASSN-15lh observed with Swift ...during our follow-up campaign. The rebrightening began at t ... 90 d (observer frame) after the primary peak and was followed by a ~120-d long plateau in the bolometric luminosity, before starting to fade again at t ... 210 d. ASASSN-15lh rebrightened in the Swift UV bands by ...mUVW2 ... -1.75 mag, ...mUVM2 ... -1.25 mag and ...mUVW1 ... -0.8 mag, but did not rebrighten in the optical bands. Throughout its initial decline, subsequent rebrightening and renewed decline, the spectra did not show evidence of interactions between the ejecta and circumstellar medium such as narrow emission lines. There are hints of weak Ha emission at late-times, but Margutti et al. have shown that it is narrow line emission consistent with star formation in the host nucleus. By fitting a blackbody, we find that during the rebrightening, the effective photospheric temperature increased from TBB ... 11 000 K to TBB ... 18 000 K. Over the ~ 550 d since its detection, ASASSN-15lh has radiated ~1.7 -1.9 x 10 super( 52) erg. Although its physical nature remains uncertain, the evolution of ASASSN-15lh's photospheric radius, its radiated energy and the implied event rate, are all more similar to those of H-poor superluminous supernovae than to tidal disruption events. (ProQuest: ... denotes formulae/symbols omitted.)
We present optical light curves, redshifts, and classifications for spectroscopically confirmed Type Ia supernovae (SNe Ia) discovered by the Pan-STARRS1 (PS1) Medium Deep Survey. We detail ...improvements to the PS1 SN photometry, astrometry, and calibration that reduce the systematic uncertainties in the PS1 SN Ia distances. We combine the subset of PS1 SNe Ia (0.03 < z < 0.68) with useful distance estimates of SNe Ia from the Sloan Digital Sky Survey (SDSS), SNLS, and various low-z and Hubble Space Telescope samples to form the largest combined sample of SNe Ia, consisting of a total of SNe Ia in the range of 0.01 < z < 2.3, which we call the "Pantheon Sample." When combining Planck 2015 cosmic microwave background (CMB) measurements with the Pantheon SN sample, we find and for the wCDM model. When the SN and CMB constraints are combined with constraints from BAO and local H0 measurements, the analysis yields the most precise measurement of dark energy to date: and for the CDM model. Tension with a cosmological constant previously seen in an analysis of PS1 and low-z SNe has diminished after an increase of 2× in the statistics of the PS1 sample, improved calibration and photometry, and stricter light-curve quality cuts. We find that the systematic uncertainties in our measurements of dark energy are almost as large as the statistical uncertainties, primarily due to limitations of modeling the low-redshift sample. This must be addressed for future progress in using SNe Ia to measure dark energy.
This study investigated the in vitro susceptibilities of methicillin-resistant
Staphylococcus aureus
(MRSA) to nine antimicrobial agents in Taiwan. A total of 1,725 isolates were obtained from 20 ...hospitals throughout Taiwan from 2006 to 2010. The minimum inhibitory concentrations (MICs) of the nine agents were determined by the agar dilution method. The MICs of mupirocin and tyrothricin were determined for 223 MRSA isolates collected from 2009 to 2010. For vancomycin, 99.7 % were susceptible; however, 30.0 % (
n
= 517) exhibited MICs of 2 μg/ml and 0.3 % (
n
= 6) demonstrated intermediate susceptibility (MICs of 4 μg/ml). Nearly all isolates (≥99.9 %) were susceptible to teicoplanin, linezolid, and daptomycin. The MIC
90
values were 2 μg/ml for ceftobiprole and 1 μg/ml for nemonoxacin. The MIC
90
values of mupirocin and tyrothricin were 0.12 and 4 μg/ml, respectively. MIC creep was noted for daptomycin during this period, but not for vancomycin, teicoplanin, linezolid, or tigecycline. For isolates with vancomycin MICs of 2 μg/ml, the MIC
90
values were 2 μg/ml for teicoplanin, 0.5 μg/ml for daptomycin, and 0.5 μg/ml for tigecycline. Those values were four- to eight-fold higher than those among isolates with vancomycin MICs of 0.5 μg/ml (2, 0.06, and 0.12 μg/ml, respectively). Of the nine MRSA isolates exhibiting non-susceptibility to vancomycin (
n
= 6), teicoplanin (
n
= 1), daptomycin (
n
= 2), or tigecycline (
n
= 1), all had different pulsotypes, indicating the absence of intra-hospital or inter-hospital spread. The presence of a high proportion of MRSA isolates with elevated MICs (2 μg/ml) and MIC creep of daptomycin might alert clinicians on the therapy for serious MRSA infections in Taiwan.
We discovered Swope Supernova Survey 2017a (SSS17a) in the LIGO/Virgo Collaboration (LVC) localization volume of GW170817, the first detected binary neutron star (BNS) merger, only 10.9 hr after the ...trigger. No object was present at the location of SSS17a only a few days earlier, providing a qualitative spatial and temporal association with GW170817. Here, we quantify this association, finding that SSS17a is almost certainly the counterpart of GW170817, with the chance of a coincidence being ≤ (90% confidence). We arrive at this conclusion by comparing the optical properties of SSS17a to other known astrophysical transients, finding that SSS17a fades and cools faster than any other observed transient. For instance, SSS17a fades >5 mag in g within 7 days of our first data point, while all other known transients of similar luminosity fade by <1 mag during the same time period. Its spectra are also unique, being mostly featureless, even as it cools. The rarity of "SSS17a-like" transients combined with the relatively small LVC localization volume and recent non-detection imply the extremely unlikely chance coincidence. We find that the volumetric rate of SSS17a-like transients is ≤ Gpc−3 yr−1 and the Milky Way rate is per century. A transient survey designed to discover similar events should be high cadence and observe in red filters. The LVC will likely detect substantially more BNS mergers than current optical surveys will independently discover SSS17a-like transients, however a 1 day cadence survey with the Large Synoptic Survey Telescope (LSST) could discover an order of magnitude more events.
Introduction & Aims
Haemophilic arthropathy (HA) is a major complication in patients with haemophilia (PWH), but the study of age‐specific prevalence and severity of HA is very limited in Asian ...countries.
Materials & Methods
This study retrospectively reviewed 146 severe‐ and moderate‐type Taiwanese PWH aged 4–73 years, with roentgenograms of elbows, knees and ankles and calculated Pettersson scores.
Results
The prevalence of HA, mean number of HAs per patient and mean Pettersson scores of all the joints were 42.8%, 1.3 and 1.9 points in PWH aged 4–10 years; 64.3%, 1.4 and 4.1 points in PWH aged 11–19 years; 97.1%, 2.9 and 15.6 points in PWH aged 20–29 years; 93.1%, 4.4 and 33.1 points in PWH aged 30–39 years; 100%, 5.1 and 46.1 points in PWH aged 40–49 years and 100%, 5 and 49.6 points in PWH aged ≥50 years, respectively. There was a high prevalence of HA for PWH aged ≥20 years. Among PWH aged <20 years, prevalence of HA was low and mild ankle arthropathy was the most common. Besides, in the four age groups aged <40 years, the prevalence of ankle arthropathy was the highest, followed by elbow arthropathy and then knee arthropathy.
Conclusions
Although severe arthropathy of the six major joints was rare in PWH aged <30 years, it increased rapidly in PWH after 30 years. Analysis of clinical correlates suggested that age, severity of haemophilia, absence of prophylaxis and presence of HCV infection correlated positively with Pettersson scores.
We report the results of a three-year-long dedicated monitoring campaign of a restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and ...spectroscopically in the optical and near-infrared domains. In this paper, we present the full historical data set from 2009 to 2012 with multi-wavelength dense coverage of the two high-luminosity events between 2012 August and September. We construct bolometric light curves and measure the total luminosities of these eruptive or explosive events. We propose that the high intrinsic luminosity of the latest peak, the variability history of SN 2009ip, and the detection of broad spectral lines indicative of high-velocity ejecta are consistent with a pulsational pair-instability event, and that the star may have survived the last outburst. The question of the survival of the LBV progenitor star and its future fate remain open issues, only to be answered with future monitoring of this historically unique explosion.
Abstract
The ejecta velocities of Type Ia supernovae (SNe Ia), as measured by the Si
ii
λ
6355 line, have been shown to correlate with other supernova properties, including color and standardized ...luminosity. We investigate these results using the Foundation Supernova Survey, with a spectroscopic data release presented here, and photometry analyzed with the SALT2 light-curve fitter. We find that the Foundation data do not show significant evidence for an offset in color between SNe Ia with high and normal photospheric velocities, with Δ
c
= 0.004 ± 0.015. Our SALT2 analysis does show evidence for redder high-velocity SNe Ia in other samples, including objects from the Carnegie Supernova Project, with a combined sample yielding Δ
c
= 0.018 ± 0.008. When split on velocity, the Foundation SNe Ia also do not show a significant difference in Hubble diagram residual, Δ
HR
= 0.015 ± 0.049 mag. Intriguingly, we find that SN Ia ejecta velocity information may be gleaned from photometry, particularly in redder optical bands. For high-redshift SNe Ia, these rest-frame red wavelengths will be observed by the Nancy Grace Roman Space Telescope. Our results are in line with previous work that suggests SN Ia host-galaxy stellar mass is correlated with ejecta velocity: high-velocity SNe Ia are found nearly exclusively in high-stellar-mass hosts. However, host-galaxy properties alone do not explain velocity-dependent differences in supernova colors and luminosities across samples. Measuring and understanding the connection between intrinsic explosion properties and supernova environments, across cosmic time, will be important for precision cosmology with SNe Ia.
Aims
This study investigated the role of L‐3‐n‐Butylphthalide (NBP) in cardiac protection.
Methods
The left anterior descending coronary arteries (LAD) of the rats were occluded for 30 min following ...by 2‐h reperfusion to make the ischaemia/reperfusion models. Neonatal cardiomyocytes were cultured and subjected to hypoxia. L‐3‐n‐Butylphthalide was administered intraperitoneally 2 h before the surgery and right after the reperfusion in the in vivo experiments or added to the culture medium in vitro. Haemodynamic parameters were recorded to evaluate the cardiac functions, triphenyltetrazolium chloride (TTC) and Evens blue staining were used to determine the area of risk and infarct area, apoptotic cell numbers were counted with terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining. Western blotting was used to determine the apoptotic protein levels and immune staining to determine the translocation of Glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) protein.
Results
Our research showed for the first time that L‐3‐n‐Butylphthalide had great effects in improving cardiac hemodynamic function and decreasing cardiac infarct areas and apoptotic cell numbers in the peri‐infarct areas. The apoptotic signals investigation showed that L‐3‐n‐Butylphthalide affected the mitochondrial pathway including Bcl‐2 protein expression, inhibition of caspase 3 activation and cytochrome C releasing. Besides, Glyceraldehyde‐3‐phosphate dehydrogenase protein translocation was inhibited by L‐3‐n‐Butylphthalide treatment, and this effect was mediated by endogenous reactive oxygen species (ROS).
Conclusion
L‐3‐n‐Butylphthalide protects cardiomyocytes from ischaemia/reperfusion‐induced apoptosis by antioxidant effect and affecting mitochondrial apoptotic pathway.
Time-domain science has undergone a revolution over the past decade, with tens of thousands of new supernovae (SNe) discovered each year. However, several observational domains, including SNe within ...days or hours of explosion and faint, red transients, are just beginning to be explored. Here we present the Young Supernova Experiment (YSE), a novel optical time-domain survey on the Pan-STARRS telescopes. Our survey is designed to obtain well-sampled griz light curves for thousands of transient events up to z 0.2. This large sample of transients with four-band light curves will lay the foundation for the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope, providing a critical training set in similar filters and a well-calibrated low-redshift anchor of cosmologically useful SNe Ia to benefit dark energy science. As the name suggests, YSE complements and extends other ongoing time-domain surveys by discovering fast-rising SNe within a few hours to days of explosion. YSE is the only current four-band time-domain survey and is able to discover transients as faint as ∼21.5 mag in gri and ∼20.5 mag in z, depths that allow us to probe the earliest epochs of stellar explosions. YSE is currently observing approximately 750 deg2 of sky every 3 days, and we plan to increase the area to 1500 deg2 in the near future. When operating at full capacity, survey simulations show that YSE will find ∼5000 new SNe per year and at least two SNe within 3 days of explosion per month. To date, YSE has discovered or observed 8.3% of the transient candidates reported to the International Astronomical Union in 2020. We present an overview of YSE, including science goals, survey characteristics, and a summary of our transient discoveries to date.
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