17,777 research outputs found
The Phoenix Drone: An Open-Source Dual-Rotor Tail-Sitter Platform for Research and Education
In this paper, we introduce the Phoenix drone: the first completely
open-source tail-sitter micro aerial vehicle (MAV) platform. The vehicle has a
highly versatile, dual-rotor design and is engineered to be low-cost and easily
extensible/modifiable. Our open-source release includes all of the design
documents, software resources, and simulation tools needed to build and fly a
high-performance tail-sitter for research and educational purposes. The drone
has been developed for precision flight with a high degree of control
authority. Our design methodology included extensive testing and
characterization of the aerodynamic properties of the vehicle. The platform
incorporates many off-the-shelf components and 3D-printed parts, in order to
keep the cost down. Nonetheless, the paper includes results from flight trials
which demonstrate that the vehicle is capable of very stable hovering and
accurate trajectory tracking. Our hope is that the open-source Phoenix
reference design will be useful to both researchers and educators. In
particular, the details in this paper and the available open-source materials
should enable learners to gain an understanding of aerodynamics, flight
control, state estimation, software design, and simulation, while experimenting
with a unique aerial robot.Comment: In Proceedings of the IEEE International Conference on Robotics and
Automation (ICRA'19), Montreal, Canada, May 20-24, 201
Serum and synovial fluid lipidomic profiles predict obesity-associated osteoarthritis, synovitis, and wound repair
High-fat diet-induced obesity is a major risk factor for osteoarthritis (OA) and diminished wound healing. The objective of this study was to determine the associations among serum and synovial fluid lipid levels with OA, synovitis, adipokine levels, and wound healing in a pre-clinical obese mouse model of OA. Male C57BL/6 J mice were fed either a low-fat (10% kcal) or one of three high-fat (HF, 60% kcal) diets rich in saturated fatty acids (SFAs), ω-6 or ω-3 polyunsaturated FAs (PUFAs). OA was induced by destabilization of the medial meniscus. Mice also received an ear punch for evaluating wound healing. Serum and synovial fluid were collected for lipidomic and adipokine analyses. We demonstrated that the serum levels of ω-3 PUFAs were negatively correlated with OA and wound size, but positively correlated with adiponectin levels. In contrast, most ω-6 PUFAs exhibited positive correlations with OA, impaired healing, and inflammatory adipokines. Interestingly, levels of pentadecylic acid (C15:0, an odd-chain SFA) and palmitoleic acid were inversely correlated with joint degradation. This study extends our understanding of the links of FAs with OA, synovitis and wound healing, and reports newly identified serum and synovial fluid FAs as predictive biomarkers of OA in obesity
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Tildrakizumab in the treatment of psoriasis: latest evidence and place in therapy.
Psoriasis is a chronic inflammatory disorder that is clinically characterized by scaly cutaneous plaques. New evidence suggests that dysregulation of interleukin (IL)-23, a key cytokine in the T-helper-17 pathway, plays a vital role in the development of psoriatic systemic inflammation. The novel biologic medication tildrakizumab is among the first drugs with specific action against IL-23 that has recently been approved by the United States Food and Drug Administration and the European Medicines Agency for moderate-to-severe psoriasis. Tildrakizumab has been shown in large randomized controlled trials to be effective in improving skin manifestations as well as enhancing quality of life outcomes in patients with psoriasis. Its simple dosing, prolonged duration of action, and mild adverse event profile make it a practical option for patients; however, only a small number of trials have investigated the clinical effectiveness of tildrakizumab, and long-term data regarding the drug's efficacy and safety are currently limited. Hence, further research is needed to better understand the risks and benefits of tildrakizumab. This review summarizes and analyzes phase I, phase II, and phase III clinical trials that investigate the mechanism, pharmacokinetics, efficacy, and safety of tildrakizumab. It also identifies areas in which additional studies are warranted to further elucidate the advantages of tildrakizumab over other biologic therapies
Photoluminescence and x-ray diffraction studies of the diffusion behavior of lattice matched InGaAs/InP heterostructures
Copyright (2003) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The following article appeared in (F. Bollet and W. P. Gillin, J. Appl. Phys. 94, 988 (2003) and may be found at http://link.aip.org/link/?jap/94/988
Sentinel Node Biopsy for Head and Neck Cutaneous Melanoma
Sentinel lymph node biopsy is the most precise and accurate staging technique for malignant melanoma. This resulted from international collaborations and technical innovations across subspecialties and systematic and methodical study of real-time clinical problems. This article describes sentinel node biopsy from conception to current techniques. Indications for the procedure and evidence of its prognostic value are discussed. Controversies surrounding results of Multicenter Selective Lymphadenectomy Trial I and II and German Dermatologic Cooperative Oncology Group Selective Lymphadenectomy trial are reviewed. Head and neck melanoma is presented as a unique subsite for performing sentinel node biopsy and when considering completion cervical lymphadenectomy
Aviation Education Impacts on Cockpit Culture of Chinese Student Pilots
The safety of the aviation industry heavily depends on the performance of pilots. A pilot with a good cockpit culture improves safety performance. However, a lack of understanding of how a well-established aviation program impacts student pilots’ cockpit culture regarding power distance, masculinity, individualism, and uncertainty avoidance. This study aimed to investigate the training effect on Chinese student perceptions regarding power distance, masculinity, individualism, and uncertainty avoidance, and its related variables. The study collected 726 Chinese student pilots and analyzed their cockpit culture based on the survey data. The study examined the academic tenure influences on cockpit culture variables within student pilots. The profile analysis indicated that first-year students, sophomores, juniors, and seniors had different profiles regarding the cockpit culture variables. Outcomes show that there is a positive influence on Chinese student pilots’ perception of power distance and individualism. The perception of masculinity increases with their academic tenures and uncertainty avoidance has a periodical pattern
Nano-structured morphological features of pulsed direct current magnetron sputtered Mo films for photovoltaic applications
Historically, molybdenum thin films have been used as the back contact for Cu(In,Ga)Se2 based solar cells and as such the properties of these layers play an important role in the overall cell structure. This paper describes the production of molybdenum films using pulsed d.c magnetron sputtering from compressed molybdenum powder targets. The films were deposited at different substrate temperatures under constant power and constant current modes, and analysed using X-ray diffraction, scanning electron microscopy, atomic force microscopy and four point resistance probe. Mechanical strain and resistivity were found to decrease with substrate temperature together with a shift in the (110) crystallographic plane towards higher diffraction angles. All films were well adhered to the glass substrates irrespective of their high tensile strain. Surface morphology analysis revealed the presence of nano-structured stress relief patterns which can enhance the nucleation sites for subsequent CuInSe2 deposition. A high-resolution cross sectional image showed the columnar growth of the films. Surface roughness analysis revealed that roughness increased with increase in substrate temperature
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