484 research outputs found
CFD predictions of near-field pressure signatures of a low-boom aircraft
A three dimensional Euler marching code has been utilized to predict near-field pressure signatures of an aircraft with low boom characteristics. Computations were extended to approximately six body lengths aft of the aircraft in order to obtain pressure data at three body lengths below the aircraft for a cruise Mach number of 1.6. The near-field pressure data were extrapolated to the ground using a Whitham based method. The distance below the aircraft where the pressure data are attained is defined in this paper as the 'separation distance.' The influences of separation distances and the still highly three-dimensional flow field on the predicted ground pressure signatures and boom loudness are presented in this paper
Fluid-structure interaction assessment of blood flow hemodynamics and leaflet stress during mitral regurgitation
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The cost-effectiveness of ivermectin vs. albendazole in the presumptive treatment of strongyloidiasis in immigrants to the United States
The presumptive treatment of parasitosis among immigrants with albendazole has been shown to save both money and lives, primarily via a reduction in the burden of Strongyloides stercoralis. Ivermectin is more effective than albendazole, but is also more expensive. This coupled with confusion surrounding the cost-effectiveness of guiding therapy based on eosinophil counts has led to disparate practices. We used the newly arrived year 2000 immigrant population as a hypothetical cohort in a decision analysis model to examine the cost-effectiveness of various interventions to reduce parasitosis among immigrants. When the prevalence of S. stercoralis is greater than 2%, the incremental cost-effectiveness ratios of all presumptive treatment strategies were similar. Ivermectin is associated with an incremental cost-effectiveness ratio of $1700 per QALY gained for treatment with 12 mg ivermectin relative to 5 days of albendazole when the prevalence is 10%. Any presumptive treatment strategy is cost-effective when compared with most common medical interventions
Laser Trabeculoplasty and Aqueous Dynamics
For the past four decades, laser trabeculoplasty has been a staple in the treatment armamentarium against glaucoma. Although the exact mechanism of laser trabeculoplasty has not been fully elucidated, its clinical utility in lowering intraocular pressure has been well established. Aqueous dynamic studies uniformly reveal an increase in aqueous outflow facility at the trabecular meshwork. Accumulating evidence suggests that the mechanism is the result of complex cellular and biochemical processes. Histopathological studies of the trabecular meshwork tissue after argon laser suggest an additional mechanical role. The traditional treatment algorithm for glaucoma placed laser trabeculoplasty as an intermediary between medical therapy and incisional surgery. However, because of the safety profile of selective laser trabeculoplasty, recent studies have challenged this treatment paradigm. One such study was a multicenter trial headed by our department that compared laser trabeculoplasty and medical therapy as initial treatment for glaucoma. We showed a similar efficacy between the two modalities, reinforcing the possibility of using laser as the initial treatment in the right clinical setting
No association between blood-based markers of immune system and migraine status:a population-based cohort study
Background: Although some evidence implicates the immune system in migraine attacks, its role during attack-free periods remains largely unexplored. Therefore, we assessed the association between the immune system and migraine status. Methods: From the population-based Rotterdam Study, we included 6593 participants who underwent blood sampling and migraine assessments. In the blood samples, we measured white blood-cell-based immune markers. As a marker for the innate immune system, granulocyte and platelet counts were determined, whereas lymphocyte counts were used as a marker for the adaptive immune system. Migraine was assessed using a validated questionnaire based on ICHD-2 criteria. We investigated associations between blood-cell counts and migraine using logistic regression models adjusting for age, sex and other variables. Results: Mean age of participants was 65.6 ± 11.2 years and 56.7% were female. The lifetime prevalence of migraine was 15.1% (995/6593). We found no statistically significant associations between granulocyte (odds ratio [OR] per standard deviation increase 1.01 95% Confidence Interval [CI]: 0.93–1.09), platelet (OR 1.01 CI: 0.94–1.09) or lymphocyte counts (OR 1.01 CI: 0.93–1.08) and migraine status.Conclusions: Our results do not support an association between white blood-cell-based immunity markers and migraine status.</p
No association between blood-based markers of immune system and migraine status:a population-based cohort study
Background: Although some evidence implicates the immune system in migraine attacks, its role during attack-free periods remains largely unexplored. Therefore, we assessed the association between the immune system and migraine status. Methods: From the population-based Rotterdam Study, we included 6593 participants who underwent blood sampling and migraine assessments. In the blood samples, we measured white blood-cell-based immune markers. As a marker for the innate immune system, granulocyte and platelet counts were determined, whereas lymphocyte counts were used as a marker for the adaptive immune system. Migraine was assessed using a validated questionnaire based on ICHD-2 criteria. We investigated associations between blood-cell counts and migraine using logistic regression models adjusting for age, sex and other variables. Results: Mean age of participants was 65.6 ± 11.2 years and 56.7% were female. The lifetime prevalence of migraine was 15.1% (995/6593). We found no statistically significant associations between granulocyte (odds ratio [OR] per standard deviation increase 1.01 95% Confidence Interval [CI]: 0.93–1.09), platelet (OR 1.01 CI: 0.94–1.09) or lymphocyte counts (OR 1.01 CI: 0.93–1.08) and migraine status.Conclusions: Our results do not support an association between white blood-cell-based immunity markers and migraine status.</p
Managing Patient Expectations with Implant Treatment
This patient came to University of the Pacific, Arthur A. Dugoni School of Dentistry to get implants and implant crowns to improve his smile, replacing his upper partial denture. Different approaches were made by the faculty to arrive at best outcomes, which took four years for the patient to receive the treatment he wanted. This abstract will further detail how the treatment was conducted and the results afterwards
Nonvolatile memory with molecule-engineered tunneling barriers
We report a novel field-sensitive tunneling barrier by embedding C60 in SiO2
for nonvolatile memory applications. C60 is a better choice than ultra-small
nanocrystals due to its monodispersion. Moreover, C60 provides accessible
energy levels to prompt resonant tunneling through SiO2 at high fields.
However, this process is quenched at low fields due to HOMO-LUMO gap and large
charging energy of C60. Furthermore, we demonstrate an improvement of more than
an order of magnitude in retention to program/erase time ratio for a metal
nanocrystal memory. This shows promise of engineering tunnel dielectrics by
integrating molecules in the future hybrid molecular-silicon electronics.Comment: to appear in Applied Physics Letter
An overview of measurement standards for power quality
Received: December 7th, 2020 ; Accepted: April 7th, 2021 ; Published: May 13th, 2021 ; Correspondence: [email protected] Quality (PQ) is a vital aspect of electrical power systems, which cannot be
neglected anymore, as an ample PQ guarantees the essential compatibility between consumer
equipment and the electricity network. The analysis of electrical parameters related to distributing
electricity is recognized as a complex engineering problem. It remains a critical task to maintain
and improve PQ in modern evolving networks as the overall system performance highly depends
on it. Future smart grids will also require a further increase in PQ levels in terms of observability,
affordability, data exchange, flexibility, and net metering, thus making the network much more
complex as it will be featuring a large amount of variable renewable-based distributed generation.
This will further require the need for the introduction of novel, efficient and intelligent
monitoring, control, and communication systems with various demand manageable resources. In
this paper, a review and comparisons have been made for different IEEE and IEC measurement
standards that are used for PQ with a specific focus on harmonic distortion as it is one of the most
important parameters in PQ and some guidelines have been suggested for future electricity
networks
α8β1 integrin regulates nutrient absorption through an Mfge8-PTEN dependent mechanism.
Coordinated gastrointestinal smooth muscle contraction is critical for proper nutrient absorption and is altered in a number of medical disorders. In this work, we demonstrate a critical role for the RGD-binding integrin α8β1 in promoting nutrient absorption through regulation of gastrointestinal motility. Smooth muscle-specific deletion and antibody blockade of α8 in mice result in enhanced gastric antral smooth muscle contraction, more rapid gastric emptying, and more rapid transit of food through the small intestine leading to malabsorption of dietary fats and carbohydrates as well as protection from weight gain in a diet-induced model of obesity. Mechanistically, ligation of α8β1 by the milk protein Mfge8 reduces antral smooth muscle contractile force by preventing RhoA activation through a PTEN-dependent mechanism. Collectively, our results identify a role for α8β1 in regulating gastrointestinal motility and identify α8 as a potential target for disorders characterized by hypo- or hyper-motility
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