Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Comparison of Clinical Characteristics and Mortality Outcome in Critical COVID-19 Patients Infected with Alpha and Omicron Variants

Hsin-I Cheng,1 Ko-Wei Chang,1 Bing-Chen Wu,1 Mei-Yuan Teo,1 Wei-Syun Hung,1 Hao-Ming Wu,1 Allen Chung-Cheng Huang,1 Chang-Wei Lin,2 Ting-Yu Lin,1 Horng-Chyuan Lin,1 Cheng-Hsun Chiu,3,4 Shu-Min Lin1,5– 7 1Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkuo, Taiwan; 2Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan; 3Department of Pediatrics, Chang Gung Children’s Hospital, Chang Gung University College of Medicine, Taoyuan City, Taiwan; 4Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan; 5Department of Respiratory Therapy, Chang Gung Memorial Hospital, Linkuo, Taiwan; 6School of Medicine, National Tsing Hua University, Hsin-Chu, Taiwan; 7School of Medicine, Chang Gung University, Taoyuan, TaiwanCorrespondence: Shu-Min Lin, Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Road, Taipei, Taiwan, Tel + (886) 3-328 1200 ext. 8467, Email [email protected]: Early reports have indicated that the Omicron variant of coronavirus disease 2019 (COVID-19) may be associated with low mortality. However, the mortality rate of critical patients in Taiwan with COVID-19 caused by different variants has not been well described.Methods: This retrospective cohort study was conducted at the Linkou Branch of Chang Gung Memorial Hospital, Taiwan, from April 2020 to September 2022. Critically ill patients who had confirmed SARS-CoV-2 infection and were on mechanical ventilation (MV) were enrolled. Demographic data, laboratory results, and treatment information were collected and analyzed. In addition, clinical outcomes for different SARS-CoV-2 variants were analyzed.Results: This study included 110 critical patients with COVID-19 who required intubation and intensive care unit (ICU) admission. Among these patients, 46 (41.8%) required intensive care during Alpha predominance period and 64 (58.2%) during the Omicron predominance period. The Alpha group had a higher body mass index, had a longer ICU stay, and included more patients with acute respiratory distress syndrome, and the Omicron group included more active smokers, had more comorbidities, had worse initial laboratory data (including higher white blood cell counts, prothrombin time [PT], activated partial prothrombin time, blood urine nitrogen levels, and creatine levels), and had higher in-hospital mortality rates (40.6% vs 15.2%, p = 0.004). The independent risk factors for in-hospital mortality, were Charlson Comorbidity Index (CCI) ≥ 3 and higher PT and creatine levels.Conclusion: Our study discovered that CCI ≥ 3, elevated serum creatine levels, and prolonged PT were independently associated with a high mortality rate in patients with critical COVID-19. Patients with those risk factors may require intensive monitoring during their treatment course.Keywords: COVID-19, intensive care, CCI, Charlson Comorbidity Index, mortalit

Amino acid transporters implicated in endocytosis of Buchnera during symbiont transmission in the pea aphid

Abstract Background Many insects host their obligate, maternally transmitted symbiotic bacteria in specialized cells called bacteriocytes. One of the best-studied insect nutritional endosymbioses is that of the aphid and its endosymbiont, Buchnera aphidicola. Aphids and Buchnera are metabolically and developmentally integrated, but the molecular mechanisms underlying Buchnera transmission and coordination with aphid development remain largely unknown. Previous work using electron microscopy to study aphid asexual embryogenesis has revealed that Buchnera transmission involves exocytosis from a maternal bacteriocyte followed by endocytotic uptake by a blastula. While the importance of exo- and endocytic cellular processes for symbiont transmission is clear, the molecular mechanisms that regulate these processes are not known. Here, we shed light on the molecular mechanisms that regulate Buchnera transmission and developmental integration. Results We present the developmental atlas of ACYPI000536 and ACYPI008904 mRNAs during asexual embryogenesis in the pea aphid, Acyrthosiphon pisum. Immediately before Buchnera invasion, transcripts of both genes were detected by whole-mount in situ hybridization in the posterior syncytial nuclei of late blastula embryos. Following Buchnera invasion, expression of both genes was identified in the region occupied by Buchnera throughout embryogenesis. Notably during Buchnera migration, expression of both genes was not concomitant with the entirety of the bacterial mass but rather expression colocalized with Buchnera in the anterior region of the bacterial mass. In addition, we found that ACYPI000536 was expressed in nuclei at the leading edge of the bacterial mass, joining the bacterial mass in subsequent developmental stages. Finally, quantitative reverse transcription real-time PCR suggested that early in development both transcripts were maternally provisioned to embryos. Conclusions We venture that ACYPI000536 and ACYPI008904 function as nutrient sensors at the site of symbiont invasion to facilitate TOR-pathway-mediated endocytosis of Buchnera by the aphid blastula. Our data support earlier reports of bacteriocyte determination involving a two-step recruitment process but suggest that the second wave of recruitment occurs earlier than previously described. Finally, our work highlights that bacteriocyte-enriched amino acid transporter paralogs have additionally been retained to play novel developmental roles in both symbiont recruitment and bacteriome development

Role of peptido-leukotrienes in the genesis of early ventricular arrhythmias during acute myocardial ischaemia in rats

Changes in cardiac ventricular concentrations of peptidoleukotrienes (peptido-LTs) following coronary artery ligation and the effects of lipoxygenase inhibition and leukotriene antagonism on the cardiovascular responses to acute myocardial ischaemia were studied in pentobarbitone-anaesthetised rats. It was found that the left ventricular peptido-LT levels significantly increased at 2.5 and 5 min after left coronary artery ligation while the changes in right ventricle were not statistically significant. Pretreatment with nordihydroguaiaretic acid 25, 50 or 100mg/kg caused marked depletion of ventricular peptido-LT content, but did not significantly prevent the blood pressure or heart rate changes, the occurrence of ventricular tachycardia or fibrillation, or the mortality of the animals following coronary artery ligation. Administration of SK and F 102922, even at doses which caused marked decreases in blood pressure and heart rate, also did not significantly alter the cardiovascular changes and the mortality rate induced by left coronary artery ligation. It is, therefore, suggested that the occurrence of ventricular arrhythmias and haemodynamic changes during the early phase of acute myocardial ischaemia may not be due to the augmented synthesis of peptido-LTs in cardiac tissue.link_to_subscribed_fulltex