5,728 research outputs found

    Prehospital Use of Cuffed Endotracheal Tubes in Pediatric Patients: Thematic Analysis of Barriers to Practice Change.

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    The prehospital use of cuffed endotracheal tubes has become an evidence-based practice recommendation. Uncuffed endotracheal tubes continue to be used by emergency medical services (EMS) that transport injured and ill children to Nemours/Alfred I Dupont Hospital for Children (N/AIDHC). Uncuffed endotracheal tubes are being used in infants and toddlers, but also in older children and adolescents. EMS agencies that refer patients to N/AIDHC were surveyed to determine the status of their implementation and use of cuffed endotracheal tubes. Of six services, two had fully implemented the use of cuffed endotracheal tubes. Dispositional resistance to change among the EMS administrators was measured and found to be lower at the services that had implemented the use of uncuffed endotracheal tubes. Implementation of the use of cuffed endotracheal tubes was most facilitated by clinical expert involvement. Outreach education by pediatric critical care experts is indicated to assist those services that have not yet implemented the use of cuffed endotracheal tubes

    Age and growth of blue rockfish (Sebastes mystinus) from central and northern California

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    Otoliths from blue rockfish (Sebastes mystinus), were aged by using a combination of surface and break-and-burn methods. The samples were collected between 1978 and 1998 off central and northern California. Annual growth increments in the otoliths were validated by using edge analysis for females up to age 23 and for males to age 25.The first annual growth increment was identified by comparing the diameter of the otolith from fish known to be one year old collected in May (when translucent zone formation was completed) to the mean diameter of the first translucent zone in the otoliths from older fish. Our estimated maxi-mum ages of 44 years for males and 41 years for females were much older than those reported in previous studies. Von Bertalanffy growth models were developed for each sex. Females grew faster and reached larger maximum length than males. The growth models were similar to those generated in other studies of this species in southern and central California. Fish from northern and central California had similar maximum sizes, maximum ages, and growth model parameters

    Massive hiatus hernia: Evaluation and surgical management

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    AbstractObjective: Paraesophageal hernias represent advanced degrees of sliding hiatus hernia with intrathoracic displacement of the intraesophageal junction. Gastroesophageal reflux disease occurs in most cases, resulting in acquired short esophagus, which should influence the type of repair selected. Methods: Between 1960 and 1996, 94 patients with massive, incarcerated paraesophageal hiatus hernia were operated on at the Toronto General Hospital. The mean age was 64 years (39 to 85 years), with a female to male ratio of 1.8:1. Organoaxial volvulus was present in 50% of cases. Clinical presentation in these patients included postprandial pain in 56%, dysphagia in 48%, chronic iron deficiency anemia in 38%, and aspiration in 29%. Symptomatic reflux, either present or remote, was recorded in 83% of cases. All patients underwent endoscopy by the operating surgeon. In 91 of 94 patients, the esophagogastric junction was found to be above the diaphragmatic hiatus, denoting a sliding type of hiatus hernia. Gross, endoscopic peptic esophagitis was observed in 36% of patients: ulcerative esophagitis in 22% and peptic esophagitis with stricture in 14%. A complete preoperative esophageal motility study was obtained for 41 patients. The lower sphincter was hypotensive in 21 patients (51%), and the amplitude of peristalsis in the distal esophagus was diminished in 24 patients (59%). These abnormalities are both features of significant gastroesophageal reflux disease. In 13 recent, consecutive patients with paraesophageal hernia, the distance between the upper and lower esophageal sphincters was measured during manometry. The average distance was 15.4 ± 2.33 cm (11 to 20 cm), which is consistent with acquired short esophagus. The normal distance is 20.4 cm ± 1.9 (p < 0.0001). Results: All 94 patients were treated surgically: 97% had a transthoracic repair with fundoplication. A gastroplasty was added in 75 cases (80%) because of clearly defined or presumed short esophagus. There were two operative deaths, and two patients were never followed up. Among the 90 available patients, the mean follow-up was 94 months; median follow-up was 72 months. Seventy-two patients (80%) are free of symptoms (excellent result); 13 (13%) have inconsequential symptoms requiring no therapy (good result); and three patients (4%) are improved but have symptoms requiring medical therapy or interval dilatation (fair result). Two patients had poor results because of recurrent hernia and severe reflux. Both were successfully treated by reoperation with the addition of gastroplasty because of acquired shortening, which was not recognized at the first operation. Conclusions: Most of these 94 patients had symptoms or endoscopic, manometric, and operative findings that were consistent with a sliding hiatus hernia. There was a high incidence of endoscopic reflux esophagitis and of acquired short esophagus. True paraesophageal hernia, with the esophagogastric junction in a normal abdominal location, appears rare. Our observations were supported by measurements obtained at preoperative endoscopy and manometry, and by findings at the time of surgical repair. These observations support the choice of a transthoracic approach for repair in most patients. (J Thorac Cardiovasc Surg 1997;115:53-62

    Non-invertible Symmetries and Higher Representation Theory II

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    In this paper we continue our investigation of the global categorical symmetries that arise when gauging finite higher groups and their higher subgroups with discrete torsion. The motivation is to provide a common perspective on the construction of non-invertible global symmetries in higher dimensions and a precise description of the associated symmetry categories. We propose that the symmetry categories obtained by gauging higher subgroups may be defined as higher group-theoretical fusion categories, which are built from the projective higher representations of higher groups. As concrete applications we provide a unified description of the symmetry categories of gauge theories in three and four dimensions based on the Lie algebra so(N)\mathfrak{so}(N), and a fully categorical description of non-invertible symmetries obtained by gauging a 1-form symmetry with a mixed 't Hooft anomaly. We also discuss the effect of discrete torsion on symmetry categories, based a series of obstructions determined by spectral sequence arguments.Comment: 56 pages + appendix, v2: clarifications and citations adde

    Resection and resolution of bone marrow lesions associated with an improvement of pain after total knee replacement: a novel case study using a 3-Tesla metal artefact reduction MRI sequence

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    We present our case report using a novel metal artefact reduction magnetic resonance imaging (MRI) sequence to observe resolution of subchondral bone marrow lesions (BMLs), which are strongly associated with pain, in a patient after total knee replacement surgery. Large BMLs were seen preoperatively on the 3-Tesla MRI scans in a patient with severe end stage OA awaiting total knee replacement surgery. Twelve months after surgery, using a novel metal artefact reduction MRI sequence, we were able to visualize the bone-prosthesis interface and found complete resection and resolution of these BMLs. This is the first reported study in the UK to use this metal artefact reduction MRI sequence at 3-Tesla showing that resection and resolution of BMLs in this patient were associated with an improvement of pain and function after total knee replacement surgery. In this case it was associated with a clinically significant improvement of pain and function after surgery. Failure to eradicate these lesions may be a cause of persistent postoperative pain that is seen in up to 20% of patients following TKR surgery

    Drilling disturbance and constraints on the onset of the Paleocene–Eocene boundary carbon isotope excursion in New Jersey

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    The onset of the Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE; about 56 million years ago) was geologically abrupt but it is debated whether it took thousands of years or was effectively instantaneous. A significant new record of the onset of the CIE was published by Wright and Schaller (2013) who claimed that it could be resolved across 13 annual layers in a drill core through the Marlboro Clay at Millville, New Jersey (Ocean Drilling Program Leg 174X). Supporting evidence of similar layering was also reported from another New Jersey drill site, Wilson Lake B, and a photograph of the Marlboro Clay in outcrop. Such a short duration would imply an instantaneous perturbation of the atmosphere and surface ocean, and the impact of a comet or asteroid as the likely cause. However it was suggested by Pearson and Nicholas (2014) from the published photographs that the layers in the Marlboro Clay could be artifacts of drilling disturbance (so-called "biscuiting", wherein the formation is fractured into layers or "biscuits" and drilling mud is injected in between). Here we report new observations on the cores which support that interpretation, including concentric grooves on the surfaces of the biscuits caused by spinning in the bit, micro-fracturing at their edges, and injected drilling mud. We re-interpret the outcrop evidence as showing joints rather than sedimentary layers. We argue that foraminifer concentrations in the sediments are far too high for the layers to be annually deposited in turbid waters at depths of 40–70 m, indicating that the onset of the CIE in the Marlboro Clay likely took on the order of millennia, not years. Re-coring of Millville to minimize drilling disturbance and allow a higher resolution study of the carbon isotope excursion is highly desirable

    Real-time diagnostics of gas/water assisted injection moulding using integrated ultrasonic sensors

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    YesAn ultrasound sensor system has been applied to the mould of both the water and gas assisted injection moulding processes. The mould has a cavity wall mounted pressure sensor and instrumentation to monitor the injection moulding machine. Two ultrasound sensors are used to monitor the arrival of the fluid (gas or water) bubble tip through the detection of reflected ultrasound energy from the fluid polymer boundary and the fluid bubble tip velocity through the polymer melt is estimated. The polymer contact with the cavity wall is observed through the reflected ultrasound energy from that boundary. A theoretically based estimation of the residual wall thickness is made using the ultrasound reflection from the fluid (gas or water) polymer boundary whilst the samples are still inside the mould and a good correlation with a physical measurement is observed

    Performance of an Annular Linear Induction Pump with Applications to Space Nuclear Power Systems

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    Results of performance testing of an annular linear induction pump are presented. The pump electromagnetically pumps liquid metal through a circuit specially designed to allow for quantification of the performance. Testing was conducted over a range of conditions, including frequencies of 33, 36, 39, and 60 Hz, liquid metal temperatures from 125 to 525 C, and input voltages from 5 to 120 V. Pump performance spanned a range of flow rates from roughly 0.16 to 5.7 L/s (2.5 to 90 gpm), and pressure head less than 1 to 90 kPa (less than 0.145 to 13 psi). The maximum efficiency measured during testing was slightly greater than 6%. The efficiency was fairly insensitive to input frequency from 33 to 39 Hz, and was markedly lower at 60 Hz. In addition, the efficiency decreased as the NaK temperature was raised. The performance of the pump operating on a variable frequency drive providing 60 Hz power compared favorably with the same pump operating on 60 Hz power drawn directly from the electrical grid
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