20 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

    Acute Hepatitis after Ingestion of a Preparation of Chinese Skullcap and Black Catechu for Joint Pain

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    Many herbal preparations are routinely used and have been occasionally associated with a wide range of side effects, from mild to severe. Chinese skullcap and black catechu are herbal medications commonly used for their hepatoprotective and other properties. We report a case of acute toxic hepatitis associated with ingestion of Chinese skullcap and black catechu in one preparation for the alleviation of joint pain

    Endocuff-Assisted Colonoscopy—A Novel Accessory in Improving Adenoma Detection Rate: A Review of the Literature

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    Endocuff (Arc Medical Design) is a U.S. Food and Drug Administration-approved device that is attached like a cap to the distal tip of the colonoscope; it is used to improve adenoma detection rates during colonoscopy. The aim of this review was to summarize and evaluate the clinical and technical efficacy of Endocuff in improving adenoma detection rate. A comprehensive literature review was performed to identify studies describing this technique. In this review article, we have summarized case series and reports describing Endocuff use and results. The reported indications, results, limitations, and complications are discussed

    Colonic Ganglioneuroma: A Rare Finding during Colorectal Cancer Screening

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    Ganglioneuromas are very rare clinical entities, and their occurrence in the large bowel lays further emphasis on their rarity. Ganglioneuromas are benign tumors of undifferentiated neural crest cells. Their clinical presentation is mostly asymptomatic, and if any symptoms are present at all, they are usually nonspecific, with excellent prognosis. We report an asymptomatic, 65-year-old male with a solitary ascending colonic polyp found on screening colonoscopy. Histology revealed benign polypoid spindle-cell proliferation as well as S100 reactivity, consistent with ganglioneuroma. We report on the clinical presentation and discuss the origin, epidemiology, treatment, and management of this lesion

    Hemostatic powder spray: a new method for managing gastrointestinal bleeding

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    Gastrointestinal bleeding is a leading cause of morbidity and mortality in the United States. The management of gastrointestinal bleeding is often challenging, depending on its location and severity. To date, widely accepted hemostatic treatment options include injection of epinephrine and tissue adhesives such as cyanoacrylate, ablative therapy with contact modalities such as thermal coagulation with heater probe and bipolar hemostatic forceps, noncontact modalities such as photodynamic therapy and argon plasma coagulation, and mechanical hemostasis with band ligation, endoscopic hemoclips, and over-the-scope clips. These approaches, albeit effective in achieving hemostasis, are associated with a 5–10% rebleeding risk. New simple, effective, universal, and safe methods are needed to address some of the challenges posed by the current endoscopic hemostatic techniques. The use of a novel hemostatic powder spray appears to be effective and safe in controlling upper and lower gastrointestinal bleeding. Although initial reports of hemostatic powder spray as an innovative approach to manage gastrointestinal bleeding are promising, further studies are needed to support and confirm its efficacy and safety. The aim of this study was to evaluate the technical feasibility, clinical efficacy, and safety of hemostatic powder spray (Hemospray, Cook Medical, Winston-Salem, North Carolina, USA) as a new method for managing gastrointestinal bleeding. In this review article, we performed an extensive literature search summarizing case reports and case series of Hemospray for the management of gastrointestinal bleeding. Indications, features, technique, deployment, success rate, complications, and limitations are discussed. The combined technical and clinical success rate of Hemospray was 88.5% (207/234) among the human subjects and 81.8% (9/11) among the porcine models studied. Rebleeding occurred within 72 hours post-treatment in 38 patients (38/234; 16.2%) and in three porcine models (3/11; 27.3%). No procedure-related adverse events were associated with the use of Hemospray. Hemospray appears to be a safe and effective approach in the management of gastrointestinal bleeding
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