The Design Method of Axial Flow Runners Focusing on Axial Flow Velocity Uniformization and Its Application to an Ultra-Small Axial Flow Hydraulic Turbine

We proposed a portable and ultra-small axial flow hydraulic turbine that can generate electric power comparatively easily using the low head of open channels such as existing pipe conduits or small rivers. In addition, we proposed a simple design method for axial flow runners in combination with the conventional one-dimensional design method and the design method of axial flow velocity uniformization, with the support of three-dimensional flow analysis. Applying our design method to the runner of an ultra-small axial flow hydraulic turbine, the performance and internal flow of the designed runner were investigated using CFD analysis and experiment (performance test and PIV measurement). As a result, the runners designed with our design method were significantly improved in turbine efficiency compared to the original runner. Specifically, in the experiment, a new design of the runner achieved a turbine efficiency of 0.768. This reason was that the axial component of absolute velocity of the new design of the runner was relatively uniform at the runner outlet in comparison with that of the original runner, and as a result, the negative rotational flow was improved. Thus, the validity of our design method has been verified

Study on an Axial Flow Hydraulic Turbine with Collection Device

We propose a new type of portable hydraulic turbine that uses the kinetic energy of flow in open channels. The turbine comprises a runner with an appended collection device that includes a diffuser section in an attempt to improve the output by catching and accelerating the flow. With such turbines, the performance of the collection device, and a composite body comprising the runner and collection device were studied using numerical analysis. Among four stand-alone collection devices, the inlet velocity ratio was most improved by the collection device featuring an inlet nozzle and brim. The inlet velocity ratio of the composite body was significantly lower than that of the stand-alone collection device, owing to the resistance of the runner itself, the decreased diffuser pressure recovery coefficient, and the increased backpressure coefficient. However, at the maximum output tip speed ratio, the inlet velocity ratio and the loading coefficient were approximately 31% and 22% higher, respectively, for the composite body than for the isolated runner. In particular, the input power coefficient significantly increased (by approximately 2.76 times) owing to the increase in the inlet velocity ratio. Verification tests were also conducted in a real canal to establish the actual effectiveness of the turbine

Polytetrafluoroethylene fume-induced pulmonary edema: a case report and review of the literature

INTRODUCTION: Polytetrafluoroethylene is ubiquitous in materials commonly used in cooking and industrial applications. Overheated polytetrafluoroethylene can generate toxic fumes, inducing acute pulmonary edema in some cases. However, neither the etiology nor the radiological features of this condition have been determined. For clarification, we report an illustrative case, together with the first comprehensive literature review. CASE PRESENTATION: A previously healthy 35-year-old Japanese man who developed severe dyspnea presented to our hospital. He had left a polytetrafluoroethylene-coated pan on a gas-burning stove for 10 hours while unconscious. Upon admission, he was in severe respiratory distress. A chest computed tomographic scan showed massive bilateral patchy consolidations with ground-glass opacities and peripheral area sparing. A diagnosis of polytetrafluoroethylene fume-induced pulmonary edema was made. He was treated with non-invasive positive pressure ventilation and a neutrophil elastase inhibitor, which dramatically alleviated his symptoms and improved his oxygenation. He was discharged without sequelae on hospital day 11. A literature review was performed to survey all reported cases of polytetrafluoroethylene fume-induced pulmonary edema. We searched the PubMed, Embase, Web of Science and OvidSP databases for reports posted between the inception of the databases and 30 September 2014, as well as several Japanese databases (Ichushi Web, J-STAGE, Medical Online, and CiNii). Two radiologists independently interpreted all chest computed tomographic images. Eighteen relevant cases (including the presently reported case) were found. Our search revealed that (1) systemic inflammatory response syndrome was frequently accompanied by pulmonary edema, and (2) common computed tomography findings were bilateral ground-glass opacities, patchy consolidation and peripheral area sparing. Pathophysiological and radiological features were consistent with the exudative phase of acute respiratory distress syndrome. However, the contrast between the lesion and the spared peripheral area was striking and was distinguishable from the common radiological features of acute respiratory distress syndrome. CONCLUSION: The essential etiology of polytetrafluoroethylene fume-induced pulmonary edema seems to be increased pulmonary vascular permeability caused by an inflammatory response to the toxic fumes. The radiological findings that distinguish polytetrafluoroethylene fume-induced pulmonary edema can be bilateral ground-glass opacity or a patchy consolidation with clear sparing of the peripheral area

Intravenous administration of mesenchymal stem cells exerts therapeutic effects on parkinsonian model of rats: Focusing on neuroprotective effects of stromal cell-derived factor-1α

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) are pluripotent stem cells derived from bone marrow with secretory functions of various neurotrophic factors. Stromal cell-derived factor-1α (SDF-1α) is also reported as one of chemokines released from MSCs. In this research, the therapeutic effects of MSCs through SDF-1α were explored. 6-hydroxydopamine (6-OHDA, 20 μg) was injected into the right striatum of female SD rats with subsequent administration of GFP-labeled MSCs, fibroblasts, (i.v., 1 × 10⁷cells, respectively) or PBS at 2 hours after 6-OHDA injection. All rats were evaluated behaviorally with cylinder test and amphetamine-induced rotation test for 1 month with consequent euthanasia for immunohistochemical evaluations. Additionally, to explore the underlying mechanisms, neuroprotective effects of SDF-1α were explored using 6-OHDA-exposed PC12 cells by using dopamine (DA) assay and TdT-mediated dUTP-biotin nick-end labeling (TUNEL) staining.</p> <p>Results</p> <p>Rats receiving MSC transplantation significantly ameliorated behaviorally both in cylinder test and amphetamine-induced rotation test compared with the control groups. Correspondingly, rats with MSCs displayed significant preservation in the density of tyrosine hydroxylase (TH)-positive fibers in the striatum and the number of TH-positive neurons in the substantia nigra pars compacta (SNc) compared to that of control rats. In the <it>in vitro </it>study, SDF-1α treatment increased DA release and suppressed cell death induced by 6-OHDA administration compared with the control groups.</p> <p>Conclusions</p> <p>Consequently, MSC transplantation might exert neuroprotection on 6-OHDA-exposed dopaminergic neurons at least partly through anti-apoptotic effects of SDF-1α. The results demonstrate the potentials of intravenous MSC administration for clinical applications, although further explorations are required.</p

Association between off-hour presentation and endotracheal-intubation-related adverse events in trauma patients with a predicted difficult airway: A historical cohort study at a community emergency department in Japan

Background: A reduction in medical staff such as occurs in hospitals during nights and weekends (off hours) is associated with a worse outcome in patients with several unanticipated critical conditions. Although difficult airway management (DAM) requires the simultaneous assistance of several appropriately trained medical caregivers, data are scarce regarding the association between off-hour presentation and endotracheal intubation (ETI)-related adverse events, especially in the trauma population. The aim of this study was to determine whether off-hour presentation was associated with ETI complications in injured patients with a predicted difficult airway. Methods: This historical cohort study was conducted at a Japanese community emergency department (ED). All patients with inhalation burn, comminuted facial trauma (Abbreviated Injury Scale Score Face ≥3), and penetrating neck injury who underwent ETI from January 2007 to January 2016 in our ED were included. Primary exposure was off-hour presentation, defined as the period from 6:01 PM to 8:00 AM weekdays plus the entire weekend. The primary outcome measure was the occurrence of an ETI-related adverse event, including hypoxemia, unrecognized esophageal intubation, regurgitation, cardiac arrest, ETI failure rescued by emergency surgical airway, cuff leak, and mainstem bronchus intubation. Results: Of the 123 patients, 75 (61.0 %) were intubated during off hours. Crude analysis showed that off-hour presentation was significantly associated with an increased risk of ETI-related adverse events [odds ratio (OR), 2.5; 95 % confidence interval (CI), 1.1–5.6; p = 0.033]. The increased risk remained significant after adjusting for potential confounders, including operator being an anesthesiologist, use of a paralytic agent, and injury severity score (OR, 3.0; 95 % CI, 1.1–8.4; p = 0.034). Conclusions: In this study, off-hour presentation was independently associated with ETI-related adverse events in trauma patients with a predicted difficult airway. These data imply the need for more attentive hospital care during nights and weekends