23 research outputs found

    Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

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    Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded

    Enterocutaneous Fistulas in the Setting of Trauma and Critical Illness

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    One of the most devastating complications to develop in the general surgical patient is an enterocutaneous fistula (ECF). Critically ill patients suffering trauma, thermal injury, infected necrotizing pancreatitis, and other acute intraabdominal pathology are at unique risk for this complication as well. By using decompressive laparotomy for abdominal compartment syndrome and leaving the abdomen open temporarily for other acute processes, survival in some instances may be improved. However, the exposed viscera are at risk for fistulization in the presence of an open abdomen, a newly defined entity termed the enteroatmospheric fistula (EAF). The purpose of this article is to describe the epidemiology of ECF in the setting of trauma and critical illness, nutrition in injured/critically ill patients with ECF, pharmacologic adjuncts to decrease fistula effluent, wound care, surgical management of the EAF/ECF, and techniques for prevention of these dreaded complications in patients with an open abdomen

    Historical Perspectives in the Care of Patients with Enterocutaneous Fistula

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    Evidence can be found throughout surgical history of how devastating an enterocutaneous fistula (ECF) can be for both patient and surgeon. From antiquity, this complication of abdominal surgery, malignancy, radiation, trauma, or inflammatory processes has been a significant challenge to surgeons due to high associated mortality and significant morbidity. An ECF causes dehydration, malnutrition, skin excoriation, and sepsis, and has profound psychological effects on the patient. Recent mortality rates of patients suffering an ECF approach 20%. The authors illustrate the history of management of patients with ECF and discuss advances in perioperative care including parasurgical care, nutrition, wound care, and the history of surgical techniques

    The Operative Burden of General Surgical Disease and Non-Battle Injury in a Deployed Military Treatment Facility in Afghanistan.

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    OBJECTIVES Contemporary medical operations support a mobile, nonconventional force involved in nation building, counterinsurgency, and humanitarian operations. Prior reports have described surgical care for disease and nonbattle injuries (DNBI). The purpose of this report is to describe the prevalence and scope of DNBI managed by general surgeons in a contemporary, deployed medical facility. METHODS A 2-year retrospective review of the operative logbook from the U.K. Role 3 Multinational Hospital, Camp Bastion, Afghanistan, was performed to determine the prevalence and makeup of procedures performed for DNBI by general surgeons. RESULTS Nontrauma general surgical procedures accounted for 7.7% (n = 279 of 3,607 cases) of cases; appendectomy (n = 146) was the most common, followed by drainage of soft tissue (n = 55) and oral abscesses (n = 5), scrotal exploration (n = 12), and hernia repair (n = 7). A total of 7.2% (n = 20 of 279) of cases fell outside the standard scope of practice of an urban, civilian general surgeon. CONCLUSION Although the prevalence of operative procedures for DNBI was low, the spectrum of cases included those not typically managed in the civilian setting of the United Kingdom. With an evolving decline in case volume performed in multiple anatomic locations due to subspecialization during surgical training, this gap in expertise is likely to increase
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