40 research outputs found

    Propfan test assessment testbed aircraft stability and control/performance 1/9-scale wind tunnel tests

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    One-ninth scale wind tunnel model tests of the Propfan Test Assessment (PTA) aircraft were performed in three different NASA facilities. Wing and propfan nacelle static pressures, model forces and moments, and flow field at the propfan plane were measured in these tests. Tests started in June 1985 and were completed in January 1987. These data were needed to assure PTA safety of flight, predict PTA performance, and validate analytical codes that will be used to predict flow fields in which the propfan will operate

    Outcome and quality of life after aorto-bifemoral bypass surgery

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    <p>Abstract</p> <p>Background</p> <p>Aorto-bifemoral bypass (AFB) is commonly performed to treat aorto-iliac disease and a durable long-term outcome is achieved. Most studies documenting beneficial outcomes after AFB have been limited to mortality and morbidity rates, costs and length of hospital stay (LOS). Few studies have examined the dependency of patients and how their perception of their own health changes after surgery. The aim of the present study was to evaluate outcome after AFB and to study its determinants.</p> <p>Methods</p> <p>This retrospective study was carried out in the multidisciplinary Post-Anaesthesia Care Unit (PACU) with five intensive care beds. Out of 1597 intensive care patients admitted to the PACU, 75 were submitted to infrarenal AFB and admitted to these intensive care unit (ICU) beds over 2 years. Preoperative characteristics and outcome were evaluated by comparing occlusive disease with aneurysmatic disease patients. Six months after discharge, the patients were contacted to complete a Short Form-36 questionnaire (SF-36) and to have their dependency in Activities of Daily Living (ADL) evaluated. Patient's characteristics and postoperative follow-up data were compared using Mann-Whitney U test, t test for independent groups, chi-square or Fisher's exact test. Patient preoperative characteristics were evaluated for associations with mortality using a multiple logistic regression analysis.</p> <p>Results</p> <p>The mortality rate was 12% at six months. Multivariate analysis identified congestive heart disease and APACHE II as independent determinants for mortality. Patients submitted to AFB for occlusive disease had worse SF-36 scores in role physical and general health perception. Patients submitted to AFB had worse SF-36 scores for all domains than a comparable urban population and had similar scores to other PACU patients. Sixty-six percent and 23% of patients were dependent in at least one activity in instrumental and personal ADL, respectively, but 64% reported having better general health.</p> <p>Conclusion</p> <p>This study shows that congestive heart disease and APACHE II were risk factors for mortality after AFB surgery. Survivors who have undergone AFB perceive an improved quality of life although they are more dependent in ADL tasks and have worse scores in almost all SF-36 than the population to which they belong.</p

    Gene Expression, Function and Ischemia Tolerance in Male and Female Rat Hearts After Sub-Toxic Levels of Angiotensin II

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    To examine the response to chronic high-dose angiotensin II (Ang II) and a proposed milder response in female hearts with respect to gene expression and ischemic injury. Female and male litterā€“matched rats were treated with 400Ā ngĀ kgāˆ’1Ā mināˆ’1 Ang II for 14Ā days. Hearts were isolated, subjected to 30-min ischemia and 30-min reperfusion in combination with functional monitoring and thereafter harvested for gene expression, WB and histology. Ang II-treated hearts showed signs of non-hypertrophic remodeling and had significantly higher end diastolic pressure after reperfusion, but no significant gender difference was detected. Ang II increased expression of genes related to heart function (ANF, Ī²-MCH, Ankrd-1, PKC-Ī±, PKC-Ī“ TNF-Ī±); fibrosis (Col I-Ī±1, Col III-Ī±1, Fn-1, Timp1) and apoptosis (P53, Casp-3) without changing heart weight but with 68% increase in collagen content. High (sub-toxic) dose of Ang II resulted in marked heart remodeling and diastolic dysfunction after ischemia without significant myocyte hypertrophy or ventricular chamber dilatation. Although there were some gender-dependent differences in gene expression, female gender did not protect against the overall response

    Hospital Pharmacy Preparedness and Pharmacist Role During Disaster in Saudi Arabia

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    Background: In case of emergencies, the number and severity of mass casualties may exceed medical services resources. Saudi Arabia is prone to different disasters, and all medical resources should be ready and prepared to serve during disasters. Pharmacists are essential during disasters; however, their roles have not been well studied during disasters in Saudi Arabia. Methods: An observational cross-sectional study targeted tertiary hospitals in Jeddah. An electronic survey, consisting of 34 questions, was developed and distributed to pharmacy directors or their representatives to investigate the hospital pharmaciesā€™ preparedness and pharmacist roles during disasters in the city of Jeddah. Results: Six hospitals participated in the survey, with a 100% response rate. All respondents confirmed the presence of disaster plans involving pharmacy departments. Hospital committee consensuses determined which medication to stock in five hospitals (83.3%). All six respondents (100%) agreed that the following medication supplies were adequate in the event of disasters: analgesics, rapid sequence intubation medications (ie, sedatives and paralytics), respiratory medications, antimicrobials, and maintenance intravenous (IV) fluids. There was disagreement on the adequacy of wound infection prophylaxis, vasopressors/inotropes, antiemetic medications, ophthalmic medications, and antidotes for chemical weapons. There were discrepancies on pharmacist roles during disaster, but hospitals agreed on the following roles: maintain effective distribution and control, collaborate on medication management, and develop and maintain first-aid skills. Conclusion: All included facilities have emergency preparedness plans for the hospitals and the pharmacy departments. However, the type and quantities of stocked medications, as well as pharmacist roles, are not well recognized. The results highlight the need for national guidance to enhance and support the preparedness of healthcare facilities. Ā© 2021 Aljabri et al.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    A comprehensive study of Al-Cu-Mg system reinforced with nano-ZrO2 particles synthesized by powder metallurgy technique

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    Abstract More focus has recently been placed on enhancing the strength, elastic modulus, coefficient of thermal expansion (CTE), wear and corrosion resistance, and other qualities of aluminum (Al) alloys by varying the quantity of ceramics added for a range of industrial uses. In this regard, Al-4.2-Cu-1.6Mg matrix nanocomposites reinforced with nano-ZrO2 particles have been created using the powder metallurgy approach. The microstructure and particle size distributions of the produced powders were analyzed using a diffraction particle size analyzer, XRD, TEM, and SEM. To achieve good sinterability, the powders were compacted and sintered in argon. The sintered nanocomposites' mechanical, elastic, and physicochemical characteristics were measured. Additionally, the behavior of corrosion, wear, and thermal expansion were examined. The results showed a decrease in the particle sizes of the Al-Cu-Mg alloy by adding ZrO2 nanoparticles up to 45.8 nm for the composite containing 16 wt.% ZrO2. By increasing the sintering temperature to 570 Ā°C, the densification of nanocomposites was enhanced. Also, the coefficient of thermal expansion and wear rate remarkably decreased by about 28 and 37.5% by adding 16 wt.% ZrO2. Moreover, microhardness yield, strength, and Youngā€™s modulus were enhanced to 161, 145, and 64%, respectively, after adding 16 wt.% ZrO2. In addition, increasing the exposure time was responsible for decreasing the corrosion rate for the same sample

    Structural systematics of the [Cu(chelate)(3)][Y](2) series. An interesting crystallographic structural insight involving vibronic coupling and the Jahn-Teller effect (JTE). The syntheses and low temperature crystal structures of tris(2,2 ' bipyridyl)copper(II) tetraphenylborate and tris(2,2 ' bipyridyl)zinc(II) tetraphenylborate

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    The crystal structures of [Cu(bipy)(3)][BPh4](2), 1, and [Zn(bipy)(3)][BPh4](2), 2 have been determined at low temperature. 1 and 2 are closely related, but are not isostructural. Both contain a two-dimensional supramolecular construct (SC) involving a sandwich structure. 1 has a six-coordinate CuN6 chromophore with a regular elongated octahedral stereochemistry and rhombic in-plane bond lengths. The associated tetragonality value, T, of 1 is 0.8868. 2 involves a six-coordinate octahedral chromophore. Differences between 1 and 2 relate to the tendency of copper(II) complexes to undergo a Jahn-Teller (JT) distortion. The zinc( II) cation feels solely the host site strain, whereas the copper( II) cation also involves vibronic JT type coupling. The copper polyhedron geometry is characterized by both phenomena, with the vibronic interaction dominating. Scatter plot analysis involving the tris-chelate copper( II) series suggests that neither pure Q(theta) or Q(epsilon) components or the a(2u) mode operate in isolation over the entire series. All three operate in combination with varying quantifiable contributions, leading to distortion from the regular tetragonal octahedral stereochemistry

    Installation effects on propeller noise

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