555 research outputs found

    Effects of a radiation dose reduction strategy for computed tomography in severely injured trauma patients in the emergency department: an observational study

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    <p>Abstract</p> <p>Background</p> <p>Severely injured trauma patients are exposed to clinically significant radiation doses from computed tomography (CT) imaging in the emergency department. Moreover, this radiation exposure is associated with an increased risk of cancer. The purpose of this study was to determine some effects of a radiation dose reduction strategy for CT in severely injured trauma patients in the emergency department.</p> <p>Methods</p> <p>We implemented the radiation dose reduction strategy in May 2009. A prospective observational study design was used to collect data from patients who met the inclusion criteria during this one year study (intervention group) from May 2009 to April 2010. The prospective data were compared with data collected retrospectively for one year prior to the implementation of the radiation dose reduction strategy (control group). By comparison of the cumulative effective dose and the number of CT examinations in the two groups, we evaluated effects of a radiation dose reduction strategy. All the patients met the institutional adult trauma team activation criteria. The radiation doses calculated by the CT scanner were converted to effective doses by multiplication by a conversion coefficient.</p> <p>Results</p> <p>A total of 118 patients were included in this study. Among them, 33 were admitted before May 2009 (control group), and 85 were admitted after May 2009 (intervention group). There were no significant differences between the two groups regarding baseline characteristics, such as injury severity and mortality. Additionally, there was no difference between the two groups in the mean number of total CT examinations per patient (4.8 vs. 4.5, respectively; p = 0.227). However, the mean effective dose of the total CT examinations per patient significantly decreased from 78.71 mSv to 29.50 mSv (p < 0.001).</p> <p>Conclusions</p> <p>The radiation dose reduction strategy for CT in severely injured trauma patients effectively decreased the cumulative effective dose of the total CT examinations in the emergency department. But not effectively decreased the number of CT examinations.</p

    Experimental and theoretical insights to demonstrate the hydrogen evolution activity of layered platinum dichalcogenides electrocatalysts

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    Abstract Hydrogen is a highly efficient and clean renewable energy source and water splitting through electrocatalytic hydrogen evolution is a most promising approach for hydrogen generation. Layered transition metal dichalcogenides-based nano-structures have recently attracted significant interest as robust and durable catalysts for hydrogen evolution. We systematically investigated the platinum (Pt) based dichalcogenides (PtS2, PtSe2 and PtTe2) as highly energetic and robust hydrogen evolution electrocatalysts. PtTe2 catalyst unveiled the rapid hydrogen evolution process with the low overpotentials of 75 and 92 mV (vs. RHE) at a current density of 10 mA cm−2, and the small Tafel slopes of 64 and 59 mV/dec in acidic and alkaline medium, respectively. The fabricated PtTe2 electrocatalyst explored a better catalytic activity than PtS2 and PtSe2. The density functional theory estimations explored that the observed small Gibbs free energy for H-adsorption of PtTe2 was given the prominent role to achieve the superior electrocatalytic and excellent stability activity towards hydrogen evolution due to a smaller bandgap and the metallic nature. We believe that this work will offer a key path to use Pt based dichalcogenides for hydrogen evolution electrocatalysts

    Graphitic carbon growth on crystalline and amorphous oxide substrates using molecular beam epitaxy

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    We report graphitic carbon growth on crystalline and amorphous oxide substrates by using carbon molecular beam epitaxy. The films are characterized by Raman spectroscopy and X-ray photoelectron spectroscopy. The formations of nanocrystalline graphite are observed on silicon dioxide and glass, while mainly sp2 amorphous carbons are formed on strontium titanate and yttria-stabilized zirconia. Interestingly, flat carbon layers with high degree of graphitization are formed even on amorphous oxides. Our results provide a progress toward direct graphene growth on oxide materials

    The appropriateness of single page of activation of the cardiac catheterization laboratory by emergency physician for patients with suspected ST-segment elevation myocardial infarction: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>The early use of reperfusion therapy has a significant effect on the prognosis of patients with ST-segment elevation myocardial infarction (STEMI), and it is recommended that emergency department (ED) physicians activate the cardiac catheterization laboratory (CCL) as soon as possible to treat these patients. The aim of this study was to examine the appropriateness of emergency physician activation of the CCL for patients with suspected STEMI. Inappropriate activations (i.e., false positive activations) were identified according to a variety of criteria.</p> <p>Methods</p> <p>All patients with emergency physician CCL activations between August 2009 and April 2011 were included in the study. False positive cases were defined according to ECG criteria and cardiologists' reviews of patients' initial clinical information.</p> <p>Results</p> <p>ED physicians used a STEMI page to activate the CCL 117 times. According to reviews by cardiologists, this activation was appropriate 89.8% of the time (in 105/117 cases). Truly unnecessary activation (i.e., cases in which STEMI was not identified by the cardiologists, no clear culprit coronary artery was present, no significant coronary artery disease and cardiac biomarkers were negative) occurred 5.1% of the time (in 6/117 cases).</p> <p>Conclusions</p> <p>CCL activation was appropriate for most patients and was unnecessary in a relatively small percentage of cases. This result supports the current recommendation for CCL activation by emergency physicians. Such early activation is a key strategy in the reduction of door-to-balloon time.</p

    Total joint reconstruction using computer-assisted surgery with stock prostheses for a patient with bilateral TMJ ankylosis

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    Backgrounds The purpose of this study is to discuss the total joint reconstruction surgery for a patient with recurrent ankylosis in bilateral temporomandibular joints (TMJs) using three-dimensional (3D) virtual surgical planning, computer-aided manufacturing (CAD/CAM)-fabricated surgical guides, and stock TMJ prostheses. Case presentation A 66-year-old female patient, who had a history of multiple TMJ surgeries, complained of severe difficulty in eating and trismus. The 3D virtual surgery was performed with a virtual surgery software (FACEGIDE, MegaGen implant, Daegu, South Korea). After confirmation of the location of the upper margin for resection of the root of the zygoma and the lower margin for resection of the ankylosed condyle, and the position of the fossa and condyle components of stock TMJ prosthesis (Biomet, Jacksonville, FL, USA), the surgical guides were fabricated with CAD/CAM technology. Under general anesthesia, osteotomy and placement of the stock TMJ prosthesis (Biomet) were carried out according to the surgical planning. At 2 months after the operation, the patient was able to open her mouth up to 30 mm without complication. Conclusion For a patient who has recurrent ankylosis in bilateral TMJs, total joint reconstruction surgery using 3D virtual surgical planning, CAD/CAM-fabricated surgical guides, and stock TMJ prostheses may be an effective surgical treatment option
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