334 research outputs found

    Properties of Ag/AgCl electrodes fabricated with IC-compatible technologies

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    The purpose of this work is to fabricate and characterize Ag/AgCl electrodes made on a silicon chip at the wafer level with integrated circuit-compatible fabrication techniques. Such electrodes are useful as reference electrodes in several kinds of chemical sensors. Two types of electrode were investigated. The first type uses an evaporated AgCl layer that is patterned with lift-off photolithography. The second type is formed by exposing a selected part of the silver substrate to a KCrO3Cl solution. Both types of electrode give the thermodynamically expected potential response to variations of Cl− ion concentration. The potential generated by the KCrO3Cl-formed electrodes was more stable, however. Auger electron spectroscopy depth profiles indicate that immersion in a KCrO3Cl solution produces a thin layer of AgCl on top of a layer of AgO. The low electronic resistance of AgO then reduces the measured series resistance of the KCrO3Cl-formed electrodes. Impedance plane plots and the impedance as a function of frequency were measured for both types of electrode, and the impedance of the evaporated AgCl electrodes was indeed considerably higher. The impedance measurements could be successfully modelled by assuming a Randles equivalent circuit for the AgCl/electrolyte interface. For the KCrO3Cl-formed electrodes, the impedance was modified by the porosity these electrodes manifested

    What is the effect of a formalised trauma tertiary survey procedure on missed injury rates in multi-trauma patients? Study protocol for a randomised controlled trial

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    Background: Missed injury is commonly used as a quality indicator in trauma care. The trauma tertiary survey (TTS) has been proposed to reduce missed injuries. However a systematic review assessing the effect of the TTS on missed injury rates in trauma patients found only observational studies, only suggesting a possible increase in early detection and reduction in missed injuries, with significant potential biases. Therefore, more robust methods are necessary to test whether implementation of a formal TTS will increase early in-hospital injury detection, decrease delayed diagnosis and decrease missed injuries after hospital discharge. Methods/Design: We propose a cluster-randomised, controlled trial to evaluate trauma care enhanced with a formalised TTS procedure. Currently, 20 to 25% of trauma patients routinely have a TTS performed. We expect this to increase to at least 75%. The design is for 6,380 multi-trauma patients in approximately 16 hospitals recruited over 24 months. In the first 12 months, patients will be randomised (by hospital) and allocated 1:1 to receive either the intervention (Group 1) or usual care (Group 2). The recruitment for the second 12 months will entail Group 1 hospitals continuing the TTS, and the Group 2 hospitals beginning it to enable estimates of the persistence of the intervention. The intervention is complex: implementation of formal TTS form, small group education, and executive directive to mandate both. Outcome data will be prospectively collected from (electronic) medical records and patient (telephone follow-up) questionnaires. Missed injuries will be adjudicated by a blinded expert panel. The primary outcome is missed injuries after hospital discharge; secondary outcomes are maintenance of the intervention effect, in-hospital missed injuries, tertiary survey performance rate, hospital and ICU bed days, interventions required for missed injuries, advanced diagnostic imaging requirements, readmissions to hospital, days of work and quality of life (EQ-5D-5 L) and mortality. Discussion: The findings of this study may alter the delivery of international trauma care. If formal TTS is (cost-) effective this intervention should be implemented widely. If not, where already partly implemented, it should be abandoned. Study findings will be disseminated widely to relevant clinicians and health funders.Griffith Health, School of MedicineFull Tex

    Twente spine model:A complete and coherent dataset for musculo-skeletal modeling of the lumbar region of the human spine

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    Item does not contain fulltextMusculo-skeletal modeling can greatly help in understanding normal and pathological functioning of the spine. For such models to produce reliable muscle and joint force estimations, an adequate set of musculo-skeletal data is necessary. In this study, we present a complete and coherent dataset for the lumbar spine, based on medical images and dissection measurements from one embalmed human cadaver. We divided muscles into muscle-tendon elements, digitized their attachments at the bones and measured morphological parameters. In total, we measured 11 muscles from one body side, using 96 elements. For every muscle element, we measured three-dimensional coordinates of its attachments, fiber length, tendon length, sarcomere length, optimal fiber length, pennation angle, mass, and physiological cross-sectional area together with the geometry of the lumbar spine. Results were consistent with other anatomical studies and included new data for the serratus posterior inferior muscle. The dataset presented in this paper enables a complete and coherent musculo-skeletal model for the lumbar spine and will improve the current state-of-the art in predicting spinal loading

    Dendritic Cells in Innate and Adaptive Immune Responses against Influenza Virus

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    Dendritic cells (DC) are major players in both innate and adaptive immune responses against influenza virus. These immune responses, as well as the important interface between the innate and adaptive systems, are orchestrated by specialized subsets of DC, including conventional steady-state DC, migratory DC and plasmacytoid DC. The characteristics and efficacy of the responses are dependent on the relative activity of these DC subsets, rendering DC crucial for the development of both naïve and memory immune responses. However, due to their critical role, DC also contribute to the immunopathological processes observed during acute influenza, such as that caused by the pathogenic H5N1 viruses. Therein, the role of different DC subsets in the induction of interferon type I, pro-inflammatory cytokine and chemokine responses is important for the outcome of interaction between the virus and host immune defences. The present review will present current knowledge on this area, relating to the importance of DC activity for the induction of efficacious humoral and cell-mediated immune responses. This will include the main viral elements associated with the triggering or inhibition of DC activation. Finally, the current knowledge on understanding how differences in various vaccines influence the manner of immune defence induction will be presented

    Thermal Ablation for Treating Tumor-induced Osteomalacia in a Patient With IV Phosphate Dependency

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    Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome associated with tumors secreting fibroblast growth factor 23 that can be cured with complete surgical resection of the tumor. However, when these tumors are at difficult locations, less invasive modalities such as thermal ablation (TA) might be a good alternative. A 40-year-old woman was seen for a second opinion because of severe hypophosphatemia with complaints of fatigue, myalgia, and muscle weakness for which she needed IV phosphate for 15 to 18 hours per day in addition to oral alfacalcidol and phosphate. Initial laboratory results revealed hypophosphatemia (0.59 mmol/L [1.83 mg/dL]; reference range, 0.90-1.50 mmol/L [8.40-10.2 mg/dL]), increased fibroblast growth factor 23 levels (137 RU/mL; reference range, &lt;125 RU/mL), and a reduced TmP-GFR (0.47 mmol/L; reference range, 0.8-1.4 mmol/L). Gallium-positron emission tomography/computed tomography (CT) showed moderately increased uptake at thoracic vertebra (Th) 8 and mildly increased uptake at Th7, suggestive of TIO. Complete tumor removal would have required resection of at least 1 vertebral body. Therefore, CT-guided TA was performed at Th8. No complications were observed, and in the months after, treatment with IV phosphate could be discontinued, indicating a satisfying result from the procedure. This extreme TIO case demonstrates that CT-guided TA can be an alternative to extensive or risky classical surgery.</p

    The effect of tertiary surveys on missed injuries in trauma:A systematic review

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    BACKGROUND: Trauma tertiary surveys (TTS) are advocated to reduce the rate of missed injuries in hospitalized trauma patients. Moreover, the missed injury rate can be a quality indicator of trauma care performance. Current variation of the definition of missed injury restricts interpretation of the effect of the TTS and limits the use of missed injury for benchmarking. Only a few studies have specifically assessed the effect of the TTS on missed injury. We aimed to systematically appraise these studies using outcomes of two common definitions of missed injury rates and long-term health outcomes. METHODS: A systematic review was performed. An electronic search (without language or publication restrictions) of the Cochrane Library, Medline and Ovid was used to identify studies assessing TTS with short-term measures of missed injuries and long-term health outcomes. ‘Missed injury’ was defined as either: Type I) any injury missed at primary and secondary survey and detected by the TTS; or Type II) any injury missed at primary and secondary survey and missed by the TTS, detected during hospital stay. Two authors independently selected studies. Risk of bias for observational studies was assessed using the Newcastle-Ottawa scale. RESULTS: Ten observational studies met our inclusion criteria. None was randomized and none reported long-term health outcomes. Their risk of bias varied considerably. Nine studies assessed Type I missed injury and found an overall rate of 4.3%. A single study reported Type II missed injury with a rate of 1.5%. Three studies reported outcome data on missed injuries for both control and intervention cohorts, with two reporting an increase in Type I missed injuries (3% vs. 7%, P<0.01), and one a decrease in Type II missed injuries (2.4% vs. 1.5%, P=0.01). CONCLUSIONS: Overall Type I and Type II missed injury rates were 4.3% and 1.5%. Routine TTS performance increased Type I and reduced Type II missed injuries. However, evidence is sub-optimal: few observational studies, non-uniform outcome definitions and moderate risk of bias. Future studies should address these issues to allow for the use of missed injury rate as a quality indicator for trauma care performance and benchmarking

    Which surgical technique may yield the best results in large, infected, segmental non-unions of the tibial shaft?:A scoping review

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    Purpose: Infected nonunion of the tibia with a large segmental bone defect is a complex and challenging condition for the patient and surgeon. This scoping review was conducted to identify existing evidence and knowledge gaps regarding this clinical scenario. Secondly, the objective of this study was to search for a valid recommendation on the optimal treatment. Methods: A comprehensive search was conducted in the bibliographic databases: PubMed, Embase.com, and Web of Science Core Collection. Studies reporting on bone transport techniques, the Masquelet technique, and vascularized fibular grafts in bone defects greater than 5 cm were included. Bone healing results and functional results were compared according to duration of nonunion, infection recurrence, bone consolidation, complication rate, external fixation time, and time until full weight-bearing. Results: Of the 2753 articles retrieved, 37 studies could be included on bone transport techniques (n = 23), the Masquelet technique (n = 7), and vascularized fibular grafts (n = 7). Respective bone union percentages were 94.3%, 89.5%, and 96.5%. The percentages of infection recurrence respectively were 1.6%, 14.4% and 7.0%, followed by respectively 1.58, 0.78, and 0.73 complications per patient. Conclusion: Bone transport was found to be the most widely studied technique in the literature. Depending on the surgeon’s expertise, vascularized fibular grafts may be held as a favourable alternative. This review indicates that further high-quality research on large bone defects (≥ 5 cm) in patients with infected tibial nonunions is necessary to gain more insight into the potentially beneficial results of vascularized fibular grafts and the Masquelet technique.</p
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