1,124 research outputs found

    Efficacy of MedMyst: an Internet Teaching Tool for Middle School Microbiology

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    Can web-based technology be used to effectively introduce or reinforce aspects of microbiology to middle school students? This central hypothesis examines whether brief exposure to a web adventure format containing virtual lab experiments and computer games within an engaging story line can impact student learning. An episodic adventure series, MedMyst (http://medmyst.rice.edu), focuses on infectious diseases and the microbes that cause them. The website is not intended to replace classroom instruction, but rather to engage students in problem-solving activities not likely to be encountered elsewhere. It also provides scientists with a resource to introduce microbiology to adolescent audiences through outreach activities. In the online adventure, the player (student) enters a futuristic world in which he or she becomes a “Reconstructor,” a member of an elite team charged with preventing the spread of infectious disease. The series consists of three “missions,” each lasting approximately 30 to 40 minutes and designed to address a limited set of learning objectives. Middle school students participated in the creation of the characters and the stylized design through focus groups. Classroom teachers oversaw the alignment of the web adventure objectives with the National Science Content Standards. Scientists and clinicians reviewed the web adventure for content and accuracy. A field test involving over 700 students from nine different schools assessed the knowledge gains attributable to playing MedMyst. Gain scores from pretest to posttest indicated that middle school students retained important information by interacting with the online material for as little as 30 minutes per adventure; however, gains for high school students were less persuasive, perhaps indicating a different learning tool or content is required for this age audience

    Lisbon’s Electric Vehicle (EV) Fleet: A Cost-Benefit Analysis of a Mass Adoption of EVs in Lisbon by 2050

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    As the impacts of climate change increase, the EU and its member countries are attempting to achieve carbon neutrality by 2050. The adoption of electric vehicles is proving to be a promising solution to achieve this goal, and specifically, reductions in the transport sector emissions. This study analyzes the potential costs and benefits resulting from a mass adoption of electric vehicles in Lisbon by 2050. Through a cost-benefit analysis, this study aims to quantify the major costs and benefits associated with electric vehicles. The results display the potential monetary benefits of a city-wide shift to electric vehicles in addition to environmental benefits. This report recommends government incentives to subsidize the diffusion of electric vehicles and emphasizes the importance of a simultaneous shift to renewable energy. These actions will promote sustainable mobility in Lisbon and set the city on a path to carbon neutrality

    Postoperative renal function preservation with nonischemic femoral arterial cannulation for thoracoabdominal aortic repair.

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    BACKGROUND: Renal failure after thoracoabdominal aortic repair is a significant clinical problem. Distal aortic perfusion for organ and spinal cord protection requires cannulation of the left femoral artery. In 2006, we reported the finding that direct cannulation led to leg ischemia in some patients and was associated with increased renal failure. After this finding, we modified our perfusion technique to eliminate leg ischemia from cannulation. In this article, we present the effects of this change on postoperative renal function. METHODS: Between February 1991 and July 2008, we repaired 1464 thoracoabdominal aortic aneurysms. Distal aortic perfusion was used in 1088, and these were studied. Median patient age was 68 years, and 378 (35%) were women. In September 2006, we began to adopt a sidearm femoral cannulation technique that provides distal aortic perfusion while maintaining downstream flow to the leg. This was used in 167 patients (15%). We measured the joint effects of preoperative glomerular filtration rate (GFR) and cannulation technique on the highest postoperative creatinine level, postoperative renal failure, and death. Analysis was by multiple linear or logistic regression with interaction. RESULTS: The preoperative GFR was the strongest predictor of postoperative renal dysfunction and death. No significant main effects of sidearm cannulation were noted. For peak creatinine level and postoperative renal failure, however, strong interactions between preoperative GFR and sidearm cannulation were present, resulting in reductions of postoperative renal complications of 15% to 20% when GFR was \u3c60 mL\u3e/min/1.73 m(2). For normal GFR, the effect was negated or even reversed at very high levels of GFR. Mortality, although not significantly affected by sidearm cannulation, showed a similar trend to the renal outcomes. CONCLUSION: Use of sidearm cannulation is associated with a clinically important and highly statistically significant reduction in postoperative renal complications in patients with a low GFR. Reduced renal effect of skeletal muscle ischemia is the proposed mechanism. Effects among patients with good preoperative renal function are less clear. A randomized trial is needed

    タカ゛ロク゛語と英語の文字習得を予測する認知能力:小学1年生から4年生まて゛の横断的研究

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    筑波大学University of Tsukuba博士(行動科学)Doctor of Philosophy in Behavioral Science2020この博士論文は内容の要約のみの公開(または一部非公開)になっていますdoctoral thesi

    タガログ語と英語の文字習得を予測する認知能力:小学1年生から4年生までの横断的研究

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    筑波大学University of Tsukuba博士(行動科学)Doctor of Philosophy in Behavioral Science2020【要旨】thesi

    Update on blunt thoracic aortic injury: Fifteen-year single-institution experience

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    ObjectivesDespite improvements in the management of blunt thoracic aortic injury, mortality remains high. We report our experience with blunt thoracic aortic injury at a level 1 trauma center over the past 15 years.MethodsBetween January 1, 1997, and January 1, 2012, data on 338 patients who presented with suspected blunt thoracic aortic injury were entered into the University of Texas Medical School at Houston Trauma Center Registry. A total of 175 patients (52%) underwent thoracic aortic repair; 29 (17%) had open repair with aortic crossclamping, 77 (44%) had open repair with distal aortic perfusion, and 69 (39%) had thoracic endovascular aortic repair. Outcomes were determined, including early mortality, morbidity, length of stay, and late survival. Multiple logistic regression analysis was used to compute adjusted estimates for the effects of the operative technique.ResultsThe early mortality for all patients with blunt thoracic aortic injury was 41% (139/338). Early mortality was 17% (27/175) for operative aortic interventions, 4% (3/69) for thoracic endovascular aortic repairs, 31% (11/29) for open repairs with aortic crossclamping, and 14% (11/77) for open repairs with distal aortic perfusion. Survival for thoracic endovascular aortic repair at 1 year and 5 years was 92% and 87%, respectively. Survival for open repair at 1, 5, 10, and 15 years was 76%, 75%, 72%, and 68%, respectively.ConclusionsBlunt thoracic aortic injury remains associated with significant early mortality. Delayed selective management, when applied with open repair with distal aortic perfusion and the use of thoracic endovascular aortic repair, has been associated with improved early outcomes. The long-term durability of thoracic endovascular aortic repair is unknown, necessitating close radiographic follow-up

    Open Repair With Latissimus Muscle Flap Coverage for Treatment of Infected Thoracic Endovascular Aneurysm Repair

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    A male patient, 70 years of age, was evaluated for an infected thoracic endovascular aneurysm repair (TEVAR). After presenting with persistent fever, a positron emission tomography scan found an infected aortic stent graft. The patient underwent open repair with explantation of the infected TEVAR, extensive periaortic debridement, graft replacement with a Dacron graft, and complete coverage with a latissimus dorsi muscle flap. Tissue culture reveale

    Hybrid Management of Type B Aortic Dissection in a Patient With Right-sided Aortic Arch and Aberrant Left Subclavian Artery

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    This report describes a patient with a right-sided aortic arch, aberrant left subclavian artery and Kommerell diverticulum, who presented with aneurysmal degeneration of the aortic root to the descending aorta, in addition to an acute type B2-10 aortic dissection. He underwent hybrid treatment with a valve-sparing aortic root replacement, transverse arch replacement with reattachment of the right subclavian artery, bilateral common carotid arteries, and thoracic endovascular aneurysm repair with left subclavian artery embolization and a left common carotid to subclavian artery bypass

    Total Aortic Arch Replacement: Superior Ventriculo-Arterial Coupling with Decellularized Allografts Compared with Conventional Prostheses.

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    BACKGROUND: To date, no experimental or clinical study provides detailed analysis of vascular impedance changes after total aortic arch replacement. This study investigated ventriculoarterial coupling and vascular impedance after replacement of the aortic arch with conventional prostheses vs. decellularized allografts. METHODS: After preparing decellularized aortic arch allografts, their mechanical, histological and biochemical properties were evaluated and compared to native aortic arches and conventional prostheses in vitro. In open-chest dogs, total aortic arch replacement was performed with conventional prostheses and compared to decellularized allografts (n = 5/group). Aortic flow and pressure were recorded continuously, left ventricular pressure-volume relations were measured by using a pressure-conductance catheter. From the hemodynamic variables end-systolic elastance (Ees), arterial elastance (Ea) and ventriculoarterial coupling were calculated. Characteristic impedance (Z) was assessed by Fourier analysis. RESULTS: While Ees did not differ between the groups and over time (4.1+/-1.19 vs. 4.58+/-1.39 mmHg/mL and 3.21+/-0.97 vs. 3.96+/-1.16 mmHg/mL), Ea showed a higher increase in the prosthesis group (4.01+/-0.67 vs. 6.18+/-0.20 mmHg/mL, P<0.05) in comparison to decellularized allografts (5.03+/-0.35 vs. 5.99+/-1.09 mmHg/mL). This led to impaired ventriculoarterial coupling in the prosthesis group, while it remained unchanged in the allograft group (62.5+/-50.9 vs. 3.9+/-23.4%). Z showed a strong increasing tendency in the prosthesis group and it was markedly higher after replacement when compared to decellularized allografts (44.6+/-8.3dyn.sec.cm-5 vs. 32.4+/-2.0dyn.sec.cm-5, P<0.05). CONCLUSIONS: Total aortic arch replacement leads to contractility-afterload mismatch by means of increased impedance and invert ventriculoarterial coupling ratio after implantation of conventional prostheses. Implantation of decellularized allografts preserves vascular impedance thereby improving ventriculoarterial mechanoenergetics after aortic arch replacement
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