Nuclear ashes and outflow in the eruptive star Nova Vul 1670

CK Vulpeculae was observed in outburst in 1670-16721, but no counterpart was seen until 1982, when a bipolar nebula was found at its location. Historically, CK Vul has been considered to be a nova (Nova Vul 1670), but a similarity to 'red transients', which are more luminous than classical nova and thought to be the result of stellar collisions, has re-opened the question of CK Vul's status. Red transients cool to resemble late M-type stars, surrounded by circumstellar material rich in molecules and dust. No stellar source has been seen in CK Vul, though a radio continuum source was identified at the expansion centre of the nebula. Here we report CK Vul is surrounded by chemically rich molecular gas with peculiar isotopic ratios, as well as dust. The chemical composition cannot be reconciled with a nova or indeed any other known explosion. In addition, the mass of the surrounding gas is too high for a nova, though the conversion from observations of CO to a total mass is uncertain. We conclude that CK Vul is best explained as the remnant of a merger of two stars.Comment: an older version of an article that appeared in Nature; published in Nature, online version, 23 March 201

PPARs as new therapeutic targets for the treatment of cerebral ischemia/reperfusion injury.

Stroke is a leading cause of death and long-term disability in industrialized countries. Despite advances in understanding its pathophysiology, little progress has been made in the treatment of stroke. The currently available therapies have proven to be highly unsatisfactory (except thrombolysis) and attempts are being made to identify and characterize signaling proteins which could be exploited to design novel therapeutic modalities. The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that control lipid and glucose metabolism. PPARs regulate gene expression by binding with the retinoid X receptor (RXR) as a heterodimeric partner to specific DNA sequences, termed PPAR response elements. In addition, PPARs may modulate gene transcription also by directly interfering with other transcription factor pathways in a DNA-binding independent manner. To date, three different PPAR isoforms, designated α, β/ δ, and γ, have been identified. Recently, they have been found to play an important role for the pathogenesis of various disorders of the central nervous system and accumulating data suggest that PPARs may serve as potential targets for treating ischemic stroke. Activation of all PPAR isoforms, but especially of PPAR γ, was shown to prevent post-ischemic inflammation and neuronal damage in several in vitro and in vivo models, negatively regulating the expression of genes induced by ischemia/ reperfusion (I/R). This paper reviews the evidence and recent developments relating to the potential therapeutic effects of PPAR-agonists in the treatment of cerebral I/R injury

A Complicated Course of Brain Tumor Resection in a Patient with a Left Ventricular Assist Device

Left ventricular assist devices (LVAD) are mechanical pumps that have become a standard treatment for end-stage heart failure. As patients with LVAD are living longer, the number of noncardiac surgeries performed in these patients is rising. However, these patients present a unique set of risk factors, some of which include acquired coagulopathies, anticoagulation status, and hemodynamic instability. Thus, performing noncardiac surgeries in patients with an LVAD requires a precise and complex surgical strategy with optimal communication among the surgical team. Therefore, knowledge of best perioperative approaches for patients with LVAD is urgently needed. Here, we present a detailed perioperative surgical approach in the case of a brain tumor resection for a 62-year-old patient with an LVAD whose course was complicated with a brain hematoma. Critical details include key aspects of monitoring patient hemodynamic stability and handling of anesthesia, patient positioning, and antiplatelet and anticoagulation drug therapy. This case highlights the importance for anesthesiologists to be well informed about perioperative LVAD management, as well as common complications that they may encounter

Detection of Vibrationally Excited CO in IRC+10216

Using the Submillimeter Array we have detected the J=3-2 and 2-1 rotational transitions from within the first vibrationally excited state of CO toward the extreme carbon star IRC+10216 (CW Leo). The emission remains spatially unresolved with an angular resolution of ~2" and, given that the lines originate from energy levels that are ~3100 K above the ground state, almost certainly originates from a much smaller (~10^{14} cm) sized region close to the stellar photosphere. Thermal excitation of the lines requires a gas density of ~10^{9} cm^{-3}, about an order of magnitude higher than the expected gas density based previous infrared observations and models of the inner dust shell of IRC+10216.Comment: Accepted for publication in ApJ Letter

Emergent Surgical Airway Skills: Time to Re-evaluate the Competencies

Introduction: One of the most challenging scenarios an anesthesia provider can face is treating a can\u27t intubate can\u27t ventilate (CICV) patient. The incidence of CICV is estimated to be around one in 10,000 cases. According to the American Society of Anesthesiology Closed Claims Study, adverse respiratory events are the most common type of injury, with difficult intubation and ventilation contributing to the majority of these cases. The objective of this non-interventional quality improvement project was to evaluate the prior training, exposure, and self-reported confidence in handling the CICV scenario among anesthesia providers at Henry Ford Hospital in Detroit, MI. Methods: An online questionnaire was distributed via email to all residents, certified registered nurse anesthetists (CRNAs), and attending anesthesiologists in March 2021. The email contained a link to an online questionnaire via Microsoft Forms (Microsoft Corporation, Redmond, WA). Univariate group comparisons were carried out between the respondents\u27 role (attending, CRNA, or resident), as well as between the number of years that the respondents were in practice (\u3c 5 years, 5-10 years, \u3e 10 years). Results: Out of the total 170 anesthesia providers, 119 participated in the study where 54 (45%) were attendings, 44 (37%) were residents, and 21 (18%) were CRNAs. The majority (75%) did not know the surgical airway kit location, and 87% had not performed the surgical airway procedure before. The vast majority (96.7%) recommended simulation training compared to online training or lecture series, and just over 50% recommended annual training frequency. When looking at the differences in responses based on years of experience as an anesthesia provider, the majority of those with \u3e 10 years in practice knew how to perform the surgical airway technique while respondents with \u3c 5 years did not know how to perform the technique, and 50% of those with five to 10 years experience knew how to perform the surgical airway procedure for a CICV scenario. Conclusion: Although there were many significant differences observed between the various provider roles and years in practice, surprisingly, the responses revealed both a lack of experience and confidence in performing the surgical airway procedure in all provider roles. These findings highlight a need for better emergency airway teaching and training. These findings will be used to guide the design and implementation of improved surgical airway training for residents, CRNAs, and attending anesthesiologists with the goal of better preparedness for handling a CICV scenario

Proper Motion of Water Masers Associated with IRAS 21391+5802: Bipolar Outflow and an AU-Scale Dusty Circumstellar Shell

We present VLBA observations of water maser emission associated with the star-forming region IRAS 21391+5802, which is embedded in a bright rimmed cometary globule in IC1396. The angular resolution of the maps is about 0.8 mas, corresponding to a spatial resolution of about 0.6 AU, at an estimated distance of 750 pc. Proper motions are derived for 10 maser features identified consistently over three epochs, which were separated by intervals of about one month. The masers appear in four groups, which are aligned linearly on the sky, roughly along a northeast-southwest direction, with a total separation of about 520 AU (about 0.7 arcseconds). The 3-D velocities of the masers have a maximum value of about 42 km/s (about 9 AU/yr). The average error on the derived proper motions is about 4 km/s. The overall pattern of proper motions is indicative of a bipolar outflow. Proper motions of the masers in a central cluster, with a projected extent of about 20 AU, show systematic deviations from a radial outflow. However, we find no evidence of Keplerian rotation, as has been claimed elsewhere. A nearly circular loop of masers lies near the middle of the cluster. The radius of this loop is 1 AU and the line-of-sight velocities of the masers in the loop are within 2 km/s of the systemic velocity of the region. These masers presumably exist at the radial distance where significant dust condensation occurs in the outflow emanating from the star.Comment: 15 pages, 4 figures. Accepted for publication in the Astrophysical Journal. Version 2.12.00: Astrometric coordinates of maser revise

Angiopoietins as Targets for Diabetic Retinopathy Treatment

Diabetic eye diseases, such as diabetic retinopathy (DR) and diabetic macular edema (DME) are among the leading causes of blindness in developed countries. Anti-VEGF therapies such as, ranibizumab, aflibercept and off-label bevacizumab have become first-line treatment for DME. While randomized controlled trials show significant improvement in vision, these anti-VEGF agents have limited durability leading to a significant treatment burden, as reflected in real-world studies, which generally demonstrate under-treatment and less favorable visual acuity outcomes than observed in prospective trials. Alternative pathways, such as the Tie-2 angiopoietin pathway may address unmet needs, with potential for greater efficacy or durability when compared to anti-VEGF monotherapy. While some Tie-2 angiopoietin therapeutic agents, such as nesvacumab, ARP-1536 or AKB-9778, did not meet primary endpoints in clinical trials, other agents have shown promise. One such agent is faricimab, a bispecific antibody inhibiting both VEGF-A and Ang-2. The phase 3 DME trials (YOSEMITE and RHINE) demonstrated favorable safety, visual, and durability outcomes; patients receiving faricimab injection every 4 months achieved similar visual gains as those receiving aflibercept injection every 2 months. Another agent, AXT107 is a peptide that inhibits VEGFR2 and modifies Ang-2 to behave more similarly to Ang-1, promoting vascular stability. This drug is currently undergoing phase 1/2a trials for safety and bioactivity to be completed in May 2022