5 research outputs found
Detachable Steerable Clip Applier for Dissection of ITA Branches
No full textThe internal thoracic artery (ITA) is increasingly being recognized as the best conduit for replacement of diseased coronary arteries. As the ITA is the main blood supply for the sternum, harvesting this artery causes a drop in blood flow, increasing the risk of failing to heal, and risking deep sternal wound infection. Current methods of harvesting the ITA are time consuming, and due to hidden arteries the manoeuvrability of the surgeon is limited. In this project the goal is to develop a new instrument for branch sealing and dissection, that increases the maneuverability, minimizes damage to surrounding tissue while beingmore time efficient. A systematical selection process resulted in the solutions for some of the sub-functions, whereas two subfunctions required more thorough analysis and evaluation. Concept selection for the sub-function Tip-Articulation a more in-depth analysis and experimental evaluation (n=19). The selection of the sub-function Handle-Mechanism is done by analysis of proven concepts, choices are based on the requirements that resulted from consultation with an experienced surgeon from LUMC, literature study, and supervision of experienced medical instrument engineers. A preliminary headroom analysis is done, resulting in an estimated drop of 64.45%for the duration of sealing and dissecting of branches with a relatively bigger diameter. Further research should specifically be aimed on the further development of the chosen concepts
Expanding Anatomy Academy in the Las Vegas Metropolitan Area: A Service Learning Project to Improve Childhood Health through Supplemental Educational Sessions
No full textChildhood obesity is a growing epidemic in the United States, with approximately 18.5% of US children presenting with obesity. High levels of obesity are less common in higher income communities, but increasingly more prevalent in lower income communities. Currently in Clark County, Nevada, more specifically in lower socioeconomic communities and Title I schools within the Las Vegas area, there is an opportunity to educate students about the components of a healthier lifestyle to provide children with the tools to improve their health. Anatomy Academy (AA) is an eight-week health education program that was created to teach fourth and fifth grade students about the various structures and functions of the human body, as well as the importance of living a healthy lifestyle in order to address the obesity epidemic. This service-learning project aimed to expand the reach of the Anatomy Academy program to more schools in the Las Vegas area in an effort to educate more underserved students about anatomy, physiology, and healthy lifestyle choices. Secondary aims included teaching fourth and fifth grade students about anatomy, physiology, and the components of a healthy lifestyle, as well as providing opportunities for professional growth to the physical therapy (PT) students administering the program. This service learning project delivered the program in two Title I elementary schools near University of Nevada, Las Vegas (UNLV), facilitated by UNLV PT student mentors and undergraduate kinesiology volunteers. Weekly sessions focused on seven body systems and included interactive activities designed to foster physical activity and engagement, with guidance provided by student mentors to enhance learning and ensure a seamless delivery of material. The program successfully expanded from two classrooms to five total classrooms over the course of three semesters. Additionally, student physical therapists reported personal and professional growth, which was measured through their application of the American Physical Therapy Association (APTA) core values throughout the program, as highlighted in post-program reflections. While no conclusions on the effectiveness of the AA program can be made from this service-learning project, the program provided valuable benefits for all stakeholders involved. Therefore, efforts should continue to be made to expand AA further, in subsequent years, to additional classrooms and schools in the Las Vegas Valley
Electromagnetic Characterization of the LISA Verification Binary ZTF J0526+5934
No full text© 2023. The Author(s). Published by the American Astronomical Society. cc-byWe present an analysis of new and archival data to the 20.506 minute LISA verification binary J052610.42+593445.32 (J0526+5934). Our joint spectroscopic and photometric analysis finds that the binary contains an unseen M 1 = 0.89 ± 0.11 M ⊙ CO-core white dwarf primary with an M 2 = 0.38 ± 0.07 M ⊙ post-core-burning subdwarf, or low-mass white dwarf, companion. Given the short orbital period and relatively large total binary mass, we find that LISA will detect this binary with signal-to-noise ratio 44 after 4 yr of observations. J0526+5934 is expected to merge within 1.8 ± 0.3 Myr and likely result in a D6 scenario Type Ia supernova or form a He-rich star that will evolve into a massive single white dwarf
An Isolated White Dwarf with a 70 s Spin Period
No full textOriginal content from this work may be used under the terms
of the Creative Commons Attribution 4.0 licence. Any further
distribution of this work must maintain attribution to the author(s) and the title
of the work, journal citation and DOI.We report the discovery of an isolated white dwarf with a spin period of 70 s. We obtained high-speed photometry of three ultramassive white dwarfs within 100 pc and discovered significant variability in one. SDSS J221141.80+113604.4 is a 1.27 M⊙ (assuming a CO core) magnetic white dwarf that shows 2.9% brightness variations in the BG40 filter with a 70.32 ± 0.04 s period, becoming the fastest spinning isolated white dwarf currently known. A detailed model atmosphere analysis shows that it has a mixed hydrogen and helium atmosphere with a dipole field strength of Bd = 15 MG. Given its large mass, fast rotation, strong magnetic field, unusual atmospheric composition, and relatively large tangential velocity for its cooling age, J2211+1136 displays all of the signatures of a double white dwarf merger remnant. Long-term monitoring of the spin evolution of J2211+1136 and other fast-spinning isolated white dwarfs opens a new discovery space for substellar and planetary mass companions around white dwarfs. In addition, the discovery of such fast rotators outside of the ZZ Ceti instability strip suggests that some should also exist within the strip. Hence, some of the monoperiodic variables found within the instability strip may be fast-spinning white dwarfs impersonating ZZ Ceti pulsators
Massive White Dwarfs in the 100 pc Sample: Magnetism, Rotation, Pulsations, and the Merger Fraction
No full text© 2024. The Author(s). Published by the American Astronomical Society. cc-byWe present a detailed model atmosphere analysis of massive white dwarfs with M > 0.9 M ⊙ and T eff ≥ 11,000 K in the Montreal White Dwarf Database 100 pc sample and the Pan-STARRS footprint. We obtained follow-up optical spectroscopy of 109 objects with no previous spectral classification in the literature. Our spectroscopic follow-up is now complete for all 204 objects in the sample. We find 118 normal DA white dwarfs, including 45 massive DAs near the ZZ Ceti instability strip. There are no normal massive DBs: the six DBs in the sample are strongly magnetic and/or rapidly rotating. There are 20 massive DQ white dwarfs in our sample, and all are found in the crystallization sequence. In addition, 66 targets are magnetic (32% of the sample). We use magnetic white dwarf atmosphere models to constrain the field strength and geometry using offset dipole models. We also use magnetism, kinematics, and rotation measurements to constrain the fraction of merger remnant candidates among this population. The merger fraction of this sample increases from 25% for 0.9-1 M ⊙ white dwarfs to 49% for 1.2-1.3 M ⊙. However, this fraction is as high as 78 − 7 + 4 % for 1.1-1.2 M ⊙ white dwarfs. Previous works have demonstrated that 5%-9% of high-mass white dwarfs stop cooling for ∼8 Gyr due to the 22Ne distillation process, which leads to an overdensity of Q-branch stars in the solar neighborhood. We demonstrate that the overabundance of the merger remnant candidates in our sample is likely due to the same process
