Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes
. Their physical origin remains unknown, but dozens of possible models have been postulated
. Some FRB sources exhibit repeat ...bursts
. Although over a hundred FRB sources have been discovered
, only four have been localized and associated with a host galaxy
, and just one of these four is known to emit repeating FRBs
. The properties of the host galaxies, and the local environments of FRBs, could provide important clues about their physical origins. The first known repeating FRB, however, was localized to a low-metallicity, irregular dwarf galaxy, and the apparently non-repeating sources were localized to higher-metallicity, massive elliptical or star-forming galaxies, suggesting that perhaps the repeating and apparently non-repeating sources could have distinct physical origins. Here we report the precise localization of a second repeating FRB source
, FRB 180916.J0158+65, to a star-forming region in a nearby (redshift 0.0337 ± 0.0002) massive spiral galaxy, whose properties and proximity distinguish it from all known hosts. The lack of both a comparably luminous persistent radio counterpart and a high Faraday rotation measure
further distinguish the local environment of FRB 180916.J0158+65 from that of the single previously localized repeating FRB source, FRB 121102. This suggests that repeating FRBs may have a wide range of luminosities, and originate from diverse host galaxies and local environments.
Background
Pulsed radiofrequency (PRF) has been widely used to treat chronic pain, but the effectiveness and mechanisms in preventing early neuropathic pain have not been well explored. Even fewer ...knowledge is available in its impact on glia‐mediated nociceptive sensitization. This study aims to elucidate the modulation of PRF on nerve injury‐induced pain development and activation of spinal mitogen‐activated protein kinases (MAPKs).
Methods
In a rat spinal nerve ligation (SNL) model, a low‐volt PRF treatment was applied to the L5 dorsal root ganglion after nerve injury. Nociceptive behaviours were measured by von Frey and heat withdrawal tests at multiple time points. MAPK activations, including p‐ERK and p‐p38, as well as TNF‐α level in the spinal dorsal horn were assessed and the cell types that expressed MAPK activation were identified by double immunofluorescence staining.
Results
We found that SNL promptly induced neuropathic pain in the affected hind limb for over 1 week as well as increased p‐ERK and p‐p38 in the spinal dorsal horn. PRF significantly attenuated SNL‐induced mechanical allodynia and thermal hyperalgesia for 5–7 days. PRF also inhibited ERK and p38 activations, which were found majorly located within neurons and microglia, respectively. Besides, PRF significantly suppressed expression of TNF‐α in the spinal dorsal horn throughout the course.
Conclusions
Low‐volt PRF significantly ameliorated SNL‐induced acute pain. Inferentially, PRF may inhibit spinal sensitization by down‐regulating spinal MAPK activations and activation‐mediated cytokine release. We demonstrated that early PRF treatment in acute nerve injury helps to ameliorate neuropathic pain development.
ABSTRACT We present observations of SN 2015bn (=PS15ae = CSS141223-113342+004332 = MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift z = 0.1136. As well as being one of ...the closest SLSNe I yet discovered, it is intrinsically brighter ( ) and in a fainter galaxy ( ) than other SLSNe at . We used this opportunity to collect the most extensive data set for any SLSN I to date, including densely sampled spectroscopy and photometry, from the UV to the NIR, spanning −50 to +250 days from optical maximum. SN 2015bn fades slowly, but exhibits surprising undulations in the light curve on a timescale of 30-50 days, especially in the UV. The spectrum shows extraordinarily slow evolution except for a rapid transformation between +7 and +20-30 days. No narrow emission lines from slow-moving material are observed at any phase. We derive physical properties including the bolometric luminosity, and find slow velocity evolution and non-monotonic temperature and radial evolution. A deep radio limit rules out a healthy off-axis gamma-ray burst, and places constraints on the pre-explosion mass loss. The data can be consistently explained by a M stripped progenitor exploding with erg kinetic energy, forming a magnetar with a spin-down timescale of ∼20 days (thus avoiding a gamma-ray burst) that reheats the ejecta and drives ionization fronts. The most likely alternative scenario-interaction with ∼20 M of dense, inhomogeneous circumstellar material-can be tested with continuing radio follow-up.
Background
Postoperative colorectal anastomotic strictures are quite common. As such, many techniques have been available to address such a problem, one of which is endoscopic dilation. The aim of ...the present study was to evaluate the long-term outcomes following endoscopic dilation using a multidiameter balloon.
Methods
A retrospective study was conducted on patients with postoperative anastomotic stenosis treated with endoscopic dilation using a multidiameter balloon at our institution, in January 2005–December 2019 were retrospectively reviewed, excluding those with tumor recurrence. Perioperative factors, complications, and recurrence rates were analyzed.
Results
There were 40 patients, (22 males and 18 females, mean age 64.6 ± 10.7 years, range 33–84 years). The median follow-up period was 56 months (interquartile range 22.5–99 months). Only 1 complication occurred, micro-perforation due to guided wire injury, which was managed conservatively. Five (12.5%) patients developed restenosis and underwent repeat balloon dilation. None of the five recurrences required more aggressive management, such as redo anastomosis.
Conclusions
Endoscopic multidiameter balloon dilation is a safe and effective method for treating benign colorectal anastomotic strictures.
The physical and chemical properties of N-heterocyclic carbene complexes used as coinage metals are explored. The history and synthesis of these metals, as well as a discussion of property ...modification, are presented.
Recent developments in the instrumentation and data analysis of synchrotron small‐angle X‐ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular ...tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small‐ and wide‐angle X‐ray scattering (SAXS–WAXS or SWAXS). The endstation features an in‐vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size‐exclusion chromatography system incorporating several optical probes including a UV–Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS–WAXS data collection and data reduction for high‐throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal‐model fittings to the data in the q range ∼0.005–2.0 Å−1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration‐dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.
A new endstation for biological small‐ and wide‐angle X‐ray scattering is detailed, which provides development opportunities for studying correlated local and global structures of biomolecules in solution.
Extracellular RNAs (exRNAs) in human body fluids are emerging as effective biomarkers for detection of diseases. Saliva, as the most accessible and noninvasive body fluid, has been shown to harbor ...exRNA biomarkers for several human diseases. However, the entire spectrum of exRNA from saliva has not been fully characterized.
Using high-throughput RNA sequencing (RNA-Seq), we conducted an in-depth bioinformatic analysis of noncoding RNAs (ncRNAs) in human cell-free saliva (CFS) from healthy individuals, with a focus on microRNAs (miRNAs), piwi-interacting RNAs (piRNAs), and circular RNAs (circRNAs).
Our data demonstrated robust reproducibility of miRNA and piRNA profiles across individuals. Furthermore, individual variability of these salivary RNA species was highly similar to those in other body fluids or cellular samples, despite the direct exposure of saliva to environmental impacts. By comparative analysis of >90 RNA-Seq data sets of different origins, we observed that piRNAs were surprisingly abundant in CFS compared with other body fluid or intracellular samples, with expression levels in CFS comparable to those found in embryonic stem cells and skin cells. Conversely, miRNA expression profiles in CFS were highly similar to those in serum and cerebrospinal fluid. Using a customized bioinformatics method, we identified >400 circRNAs in CFS. These data represent the first global characterization and experimental validation of circRNAs in any type of extracellular body fluid.
Our study provides a comprehensive landscape of ncRNA species in human saliva that will facilitate further biomarker discoveries and lay a foundation for future studies related to ncRNAs in human saliva.
Summary
Adjuvant pegylated interferon plus ribavirin treatment (PegIFN/RBV) reduces recurrence and prolongs survival in early stage hepatocellular carcinoma (HCC) patients with chronic hepatitis C ...(CHC) infection receiving resection or ablation. However, the impact of antiviral therapy in intermediate and advanced stage of CHC‐HCC patients is uncertain. This study aimed to investigate the impact PegIFN/RBV treatment on recurrence‐free interval and survival in patients with HCC receiving transarterial chemoembolization (TACE). From 2010 to 2013, 274 CHC patients from a 1073 patient‐based cohort composed of freshly diagnosed HCC and receiving TACE treatment the Chang Gung Memorial Hospital, Linkou Medical Center were recruited. Propensity score matching (PSM) (age, gender, AST to Platelet Ratio Index (APRI), tumour size, tumour number and Child‐Turcotte‐Pugh score) with the ratio 1:2 for patients with and without PegIFN/RBV treatment was performed. Statistics were performed with SPSS V.20 (IBM, USA). After matching, 153 patients were analysed and 27 patients (17.6%) achieved sustained virologic response (SVR). The 2‐year cumulative overall survival rate and recurrence‐free survival rate among patients with SVR, non‐SVR, and untreated were 85.2% vs 58.3% vs 69.6% (P=.001) and 73.3% vs 53.8% vs 58.5% (P=.013). By Cox regression analysis, non‐SVR, untreated, increase CTP score and nonresponder to TACE were independent factors related to mortality. The SVR achieved by PegIFN/RBV treatment markedly improves survival and reduces tumour recurrence in CHC‐HCC patients receiving TACE treatment after complete response.
Abstract
We present analysis of the light curves (LCs) of 77 hydrogen-poor superluminous supernovae (SLSNe I) discovered during the Zwicky Transient Facility Phase I operation. We find that the ...majority (67%) of the sample can be fit equally well by both magnetar and ejecta–circumstellar medium (CSM) interaction plus
56
Ni decay models. This implies that LCs alone cannot unambiguously constrain the physical power sources for an SLSN I. However, 23% of the sample show inverted V-shape, steep-declining LCs or features of long rise and fast post-peak decay, which are better described by the CSM+Ni model. The remaining 10% of the sample favors the magnetar model. Moreover, our analysis shows that the LC undulations are quite common, with a fraction of 18%–44% in our gold sample. Among those strongly undulating events, about 62% of them are found to be CSM-favored, implying that the undulations tend to occur in the CSM-favored events. Undulations show a wide range in energy and duration, with median values (and 1
σ
errors) being as
1.7
%
−
0.7
%
+
1.5
%
E
rad
,
total
and
28.8
−
9.1
+
14.4
days, respectively. Our analysis of the undulation timescales suggests that intrinsic temporal variations of the central engine can explain half of the undulating events, while CSM interaction (CSI) can account for the majority of the sample. Finally, all of the well-observed He-rich SLSNe Ib either have strongly undulating LCs or the LCs are much better fit by the CSM+Ni model. These observations imply that their progenitor stars have not had enough time to lose all of the He-envelopes before supernova explosions, and H-poor CSM are likely to present in these events.
Breast cancer risk assessment can inform the use of screening and prevention modalities. We investigated the performance of the Breast Cancer Surveillance Consortium (BCSC) risk model in combination ...with a polygenic risk score (PRS) comprised of 83 single nucleotide polymorphisms identified from genome-wide association studies. We conducted a nested case–control study of 486 cases and 495 matched controls within a screening cohort. The PRS was calculated using a Bayesian approach. The contributions of the PRS and variables in the BCSC model to breast cancer risk were tested using conditional logistic regression. Discriminatory accuracy of the models was compared using the area under the receiver operating characteristic curve (AUROC). Increasing quartiles of the PRS were positively associated with breast cancer risk, with OR 2.54 (95 % CI 1.69–3.82) for breast cancer in the highest versus lowest quartile. In a multivariable model, the PRS, family history, and breast density remained strong risk factors. The AUROC of the PRS was 0.60 (95 % CI 0.57–0.64), and an Asian-specific PRS had AUROC 0.64 (95 % CI 0.53–0.74). A combined model including the BCSC risk factors and PRS had better discrimination than the BCSC model (AUROC 0.65 versus 0.62,
p
= 0.01). The BCSC-PRS model classified 18 % of cases as high-risk (5-year risk ≥3 %), compared with 7 % using the BCSC model. The PRS improved discrimination of the BCSC risk model and classified more cases as high-risk. Further consideration of the PRS’s role in decision-making around screening and prevention strategies is merited.
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