63 research outputs found
The true fraction of repeating fast radio bursts revealed through CHIME source count evolution
Fast Radio Bursts (FRBs) are classified into repeaters and non-repeaters,
with only a few percent of the observed FRB population from the Canadian
Hydrogen Intensity Mapping Experiment (CHIME) confirmed as repeaters. However,
this figure represents only a lower limit due to the observational biases, and
the true fraction of repeaters remains unknown. Correcting for these biases
uncovers a notable decline in apparently non-repeating FRB detection rate as
the CHIME operational time increases. This finding suggests that a significant
portion of apparently non-repeating FRBs could in fact exhibit repetition when
observed over more extended periods. A simple population model infers that the
true repeater fraction likely exceeds 50% with 99% confidence, a figure
substantially larger than the observed face value, even consistent with 100%.
This greater prevalence of repeaters had previously gone unnoticed due to their
very low repetition rates (10 hr on average). Hence,
theoretical FRB models must incorporate these low-rate repeaters. Furthermore,
our results indicate a significantly higher repeater volume number density,
potentially exceeding observed values by up to 10 times, which in turn
impacts comparisons with potential FRB progenitors.Comment: 7 pages, 7 figures, submitted to MNRA
Overcoming the Photochemical Problem of Vitamin K in Topical Application
Topical application of vitamin K is beneficial in the treatment of various skin pathologies. However, its delivery to the skin is hampered by the photo-instability and phototoxicity of vitamin K (quinone form). Indeed, topical use of vitamin K is regulated in Europe owing to the photosensitive properties of this molecule. Here, we discuss the suitability of ester derivatives of vitamin K hydroquinone (VKH), the active form of vitamin K, for topical applications. Notably, VKH derivatives have the potential to overcome the photo-instability and phototoxicity problem of vitamin K and act as VKH prodrugs, as demonstrated in HaCaT human keratinocytes. Thus, VKH prodrug is a promising strategy for topical application of vitamin K without the need for special protection from light
Gpr19 is a circadian clock-controlled orphan GPCR with a role in modulating free-running period and light resetting capacity of the circadian clock
Gpr19 encodes an evolutionarily conserved orphan G-protein-coupled receptor (GPCR) with currently no established physiological role in vivo. We characterized Gpr19 expression in the suprachiasmatic nucleus (SCN), the locus of the master circadian clock in the brain, and determined its role in the context of the circadian rhythm regulation. We found that Gpr19 is mainly expressed in the dorsal part of the SCN, with its expression fluctuating in a circadian fashion. A conserved cAMP-responsive element in the Gpr19 promoter was able to produce circadian transcription in the SCN. Gpr19⁻/⁻mice exhibited a prolonged circadian period and a delayed initiation of daily locomotor activity. Gpr19 deficiency caused the downregulation of several genes that normally peak during the night, including Bmal1 and Gpr176. In response to light exposure at night, Gpr19⁻/⁻mice had a reduced capacity for light-induced phase-delays, but not for phase-advances. This defect was accompanied by reduced response of c-Fos expression in the dorsal region of the SCN, while apparently normal in the ventral area of the SCN, in Gpr19⁻/⁻ mice. Thus, our data demonstrate that Gpr19 is an SCN-enriched orphan GPCR with a distinct role in circadian regulation and may provide a potential target option for modulating the circadian clock
Sea Ice Thickness and Snow Depth Data Collected by Ship-based Video Observations during the 29th to 48th Japanese Antarctic Research Expeditions
On the relation between duration and energy of non-repeating fast radio bursts: census with the CHIME data
A correlation between the intrinsic energy and the burst duration of
non-repeating fast radio bursts (FRBs) has been reported. If it exists, the
correlation can be used to estimate intrinsic energy from the duration, and
thus can provide us with a new distance measure for cosmology. However, the
correlation suffered from small number statistics (68 FRBs) and was not free
from contamination by latent repeating populations, which might not have such a
correlation. How to separate/exclude the repeating bursts from the mixture of
all different types of FRBs is essential to see this property. Using a much
larger sample from the new FRB catalogue (containing 536 FRBs) recently
released by the CHIME/FRB project, combined with a new classification method
developed based on unsupervised machine learning, we carried out further
scrutiny of the relation. We found that there is a weak correlation between the
intrinsic energy and duration for non-repeating FRBs at z < 0.3 with Kendall's
tau correlation coefficient of 0.239 and significance of 0.001 (statistically
significant), whose slope looks similar to that of gamma-ray bursts. This
correlation becomes weaker and insignificant at higher redshifts (z > 0.3),
possibly due to the lack of the faint FRBs at high-z and/or the redshift
evolution of the correlation. The scattering time in the CHIME/FRB catalogue
shows an intriguing trend: it varies along the line obtained from linear fit on
the energy versus duration plane between these two parameters. A possible
cosmological application of the relation must wait for faint FRBs at high-z.Comment: 9 pages, 7 figures, accepted for publication in MNRA
Analyses of the Expression, Immunohistochemical Properties and Serodiagnostic Potential of Schistosoma japonicum Peroxiredoxin-4
Background
Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence coding homologous to this gene in the S. japonicum database was identified, characterized and expressed as recombinant SjPrx-4 protein (rSjPrx-4). Furthermore, rSjPrx-4 was evaluated in this study for its diagnostic potentials in detecting S. japonicum infection in humans. Results
The gene found in the parasite genome contained 2 active-site cysteines with conserved sequences in the predicted amino acid (AA) sequence and showed 75% identity with that of the previously characterized Prx (TPx-1) of S. japonicum. The gene was expressed in different stages of schistosome life-cycle with highest transcription level in the adult male. The gene was cloned into a plasmid vector and then transfected into Escherichia coli for expression of rSjPrx-4. Anti-rSjPrx-4 mouse sera recognized native SjPrx-4 in egg and adult worm lysate by western blotting. The result of a mixed function oxidation assay in which rSjPrx-4 prevented the nicking of DNA from hydroxyl radicals confirmed its antioxidant activity. Subsequently, immunolocalization analysis showed the localization of SjPrx-4 inside the egg, on the tegument and in the parenchyma of the adult worm. Enzyme-linked immunosorbent assay results showed that rSjPrx-4 has 83.3% sensitivity and 87.8% specificity. Its diagnostic potential was further evaluated in combination with recombinant SjTPx-1 protein, yielding an improved sensitivity and specificity of 90% and 92.7%, respectively. Conclusions
These results suggest that SjPrx-4 plays a role as an antioxidant dealing with oxidative stresses of S. japonicum, and its diagnostic potential improved by coupling it with SjTPx-1 is a proof for developing a serological test with better diagnostic performance for human schistosomiasis
Case of relapsed AIDS-related plasmablastic lymphoma treated with autologous stem cell transplantation and highly active antiretroviral therapy
Plasmablastic lymphoma is a rare and aggressive malignancy strongly associated with HIV infection. The refractory/relapsed disease rate is high, and the survival rate is characteristically poor. There are no satisfactory salvage regimens for relapsed cases. We successfully performed autologous stem cell transplantation using a regimen consisting of MCNU (ranimustine), etoposide, cytarabine, and melphalan in a Japanese patient with relapsed AIDS-related plasmablastic lymphoma of the oral cavity. Highly active antiretroviral therapy continued during the therapy. Therapy-related toxicity was tolerable, and a total of 40 Gy of irradiation was administered after autologous stem cell transplantation. The patient has remained in complete remission for 16 months since transplantation
Trends in hepatocellular carcinoma incident cases in Japan between 1996 and 2019
We examined the epidemiological trends, including the distribution of sex, age, and disease etiology, in HCC incident cases, over 24 years. Data of 20,547 HCC patients (1996–2019) were analyzed in this prospective study. We divided the study period into four 6-yearly quarters. HCC etiology was categorized as hepatitis B virus (HBV) infection, HBV + hepatitis C virus (HCV) infection, HCV infection, and both negative (non-BC). The incident cases of HCC per quarter of the study period were 4311 (21.0%), 5505 (26.8%), 5776 (28.1%), and 4955 (24.1%), sequentially. Overall, 14,020 (68.2%) patients were male. The number of HCC cases in patients < 60 years, 60–69 years, 70–79 years, and ≥ 80 years were 3711 (18.1%), 6652 (32.4%), 7448 (36.2%), and 2736 (13.3%), respectively. The average age of newly-diagnosed patients increased in each quarter. HCC was associated with HBV, HBV + HCV, and HCV infections and non-BC in 2997 (14.6%), 187 (0.9%), and 12,019 (58.5%), and 5344 (26.0%) cases, respectively. The number of HCV-associated cases decreased in each quarter, while that of non-BC-associated cases increased. HCC incident cases tend to increase in the elderly and in non-BC patients; in contrast, HCC incident cases due to HCV tend to decrease
The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016)
Background and purposeThe Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 and published in the Journal of JSICM, [2017; Volume 24 (supplement 2)] https://doi.org/10.3918/jsicm.24S0001 and Journal of Japanese Association for Acute Medicine [2017; Volume 28, (supplement 1)] http://onlinelibrary.wiley.com/doi/10.1002/jja2.2017.28.issue-S1/issuetoc.This abridged English edition of the J-SSCG 2016 was produced with permission from the Japanese Association of Acute Medicine and the Japanese Society for Intensive Care Medicine.MethodsMembers of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within each team were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ) and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a two-thirds (> 66.6%) majority vote of each of the 19 committee members.ResultsA total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in addition to ratings of the strengths of the recommendation, and its supporting evidence were also added to each recommendation statement. We conducted meta-analyses for 29 CQs. Thirty-seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for five CQs.ConclusionsBased on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals
Analysis of Expressed Sequence Tags from the Fungus Aspergillus oryzae Cultured Under Different Conditions
We performed random sequencing of cDNAs from nine biologically or industrially important cultures of the industrially valuable fungus Aspergillus oryzae to obtain expressed sequence tags (ESTs). Consequently, 21 446 raw ESTs were accumulated and subsequently assembled to 7589 non-redundant consensus sequences (contigs). Among all contigs, 5491 (72.4%) were derived from only a particular culture. These included 4735 (62.4%) singletons, i.e. lone ESTs overlapping with no others. These data showed that consideration of culture grown under various conditions as cDNA sources enabled efficient collection of ESTs. BLAST searches against the public databases showed that 2953 (38.9%) of the EST contigs showed significant similarities to deposited sequences with known functions, 793 (10.5%) were similar to hypothetical proteins, and the remaining 3843 (50.6%) showed no significant similarity to sequences in the databases. Culture-specific contigs were extracted on the basis of the EST frequency normalized by the total number for each culture condition. In addition, contig sequences were compared with sequence sets in eukaryotic orthologous groups (KOGs), and classified into the KOG functional categories
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