309 research outputs found

    CHD associated with syndromic diagnoses: peri-operative risk factors and early outcomes

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    CHD is frequently associated with a genetic syndrome. These syndromes often present specific cardiovascular and non-cardiovascular co-morbidities that confer significant peri-operative risks affecting multiple organ systems. Although surgical outcomes have improved over time, these co-morbidities continue to contribute substantially to poor peri-operative mortality and morbidity outcomes. Peri-operative morbidity may have long-standing ramifications on neurodevelopment and overall health. Recognising the cardiovascular and non-cardiovascular risks associated with specific syndromic diagnoses will facilitate expectant management, early detection of clinical problems, and improved outcomes--for example, the development of syndrome-based protocols for peri-operative evaluation and prophylactic actions may improve outcomes for the more frequently encountered syndromes such as 22q11 deletion syndrome

    Notes

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    Notes by David S. Landis, William B. Lawless, Robert Oberfell, Thomas F. Halligan, Hal E. Hunter, Jr., Charles M. Boynton, John S. Warren, Norman B. Thirion, Vail Pischke, Peter F. Nemeth, Saverio J. Alonzi, and Peter T. Alonzi

    A Flexible Path for Human and Robotic Space Exploration

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    During the summer of 2009, a flexible path scenario for human and robotic space exploration was developed that enables frequent, measured, and publicly notable human exploration of space beyond low-Earth orbit (LEO). The formulation of this scenario was in support of the Exploration Beyond LEO subcommittee of the Review of U.S. Human Space Flight Plans Committee that was commissioned by President Obama. Exploration mission sequences that allow humans to visit a wide number of inner solar system destinations were investigated. The scope of destinations included the Earth-Moon and Earth-Sun Lagrange points, near-Earth objects (NEOs), the Moon, and Mars and its moons. The missions examined assumed the use of Constellation Program elements along with existing launch vehicles and proposed augmentations. Additionally, robotic missions were envisioned as complements to human exploration through precursor missions, as crew emplaced scientific investigations, and as sample gathering assistants to the human crews. The focus of the flexible path approach was to gain ever-increasing operational experience through human exploration missions ranging from a few weeks to several years in duration, beginning in deep space beyond LEO and evolving to landings on the Moon and eventually Mars

    The 2001 Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration

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    The successful performance of the five individual demonstrations of MARS IN-SITU-PROPELLANT-PRODUCTION PRECURSOR (MIP) will provide both knowledge of and confidence in the reliability of this technology. At the completion of this flight demonstration, the MIP Team will be able to: a) recommend preferred hardware configurations for the intake and adsorption of carbon dioxide from the Martian atmosphere; b) understand the performance characteristics of zirconia cells to generate propellant-grade oxygen; c) understand long-term performance characteristics of advanced solar cells/arrays operated in the actual Mars environment; d) evaluate the functionality of methods to mitigate the deposition of airborne dust onto solar arrays; and e) recommend preferred hardware designs for innovative thermal management including the radiation of heat to the outside environment

    Immediate reexploration for the perioperative neurologic event after carotid endarterectomy: Is it worthwhile?

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    AbstractPurpose: When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon is often preoccupied with determining the cause of the problem, requesting diagnostics tests, and deciding whether the patient should be surgically reexplored. The goal of this study was to analyze a series of perioperative neurologic events and to determine if careful analysis of their timing and mechanisms can predict which cases are likely to improve with reoperation. Methods: A review of 2024 CEAs performed from 1985 to 1997 revealed 38 patients who manifested a neurologic deficit in the perioperative period (1.9%). These cases form the focus of this analysis. Results: The causes of the events included intraoperative clamping ischemia in 5 patients (13.2%); thromboembolic events in 24 (63.2%); intracerebral hemorrhage in 5 (13.2%); and deficits unrelated to the operated artery in 4 (10.5%). Neurologic events manifesting in the first 24 hours after surgery were significantly more likely to be caused by thromboembolic events than by other causes of stroke (88.0% vs 12.0%, P <.002); deficits manifesting after the first 24 hours were significantly more likely to be related to other causes. Of 25 deficits manifesting in the first 24 hours after surgery, 18 underwent immediate surgical reexploration. Intraluminal thrombus was noted in 15 of the 18 reexplorations (83.3%); any technical defects were corrected. After the 18 reexplorations, in 12 cases there was either complete resolution of or significant improvement in the neurologic deficit that had been present (66.7%). Conclusions: Careful analysis of the timing and presentation of perioperative neurologic events after CEA can predict which cases are likely to improve with reoperation. Neurologic deficits that present during the first 24 hours after CEA are likely to be related to intraluminal thrombus formation and embolization. Unless another etiology for stroke has clearly been established, we think immediate reexploration of the artery without other confirmatory tests is mandatory to remove the embolic source and correct any technical problems. This will likely improve the neurologic outcome in these patients, because an uncorrected situation would lead to continued embolization and compromise. (J Vasc Surg 2000;32:1062-70.

    Validation of the World Health Organization Tool for Situational Analysis to Assess Emergency and Essential Surgical Care at District Hospitals in Ghana

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    The World Health Organization (WHO) Tool for Situational Analysis to Assess Emergency and Essential Surgical Care (hereafter called the WHO Tool) has been used in more than 25 countries and is the largest effort to assess surgical care in the world. However, it has not yet been independently validated. Test–retest reliability is one way to validate the degree to which tests instruments are free from random error. The aim of the present field study was to determine the test–retest reliability of the WHO Tool. The WHO Tool was mailed to 10 district hospitals in Ghana. Written instructions were provided along with a letter from the Ghana Health Services requesting the hospital administrator to complete the survey tool. After ensuring delivery and completion of the forms, the study team readministered the WHO Tool at the time of an on-site visit less than 1 month later. The results of the two tests were compared to calculate kappa statistics for each of the 152 questions in the WHO Tool. The kappa statistic is a statistical measure of the degree of agreement above what would be expected based on chance alone. Ten hospitals were surveyed twice over a short interval (i.e., less than 1 month). Weighted and unweighted kappa statistics were calculated for 152 questions. The median unweighted kappa for the entire survey was 0.43 (interquartile range 0–0.84). The infrastructure section (24 questions) had a median kappa of 0.81; the human resources section (13 questions) had a median kappa of 0.77; the surgical procedures section (67 questions) had a median kappa of 0.00; and the emergency surgical equipment section (48 questions) had a median kappa of 0.81. Hospital capacity survey questions related to infrastructure characteristics had high reliability. However, questions related to process of care had poor reliability and may benefit from supplemental data gathered by direct observation. Limitations to the study include the small sample size: 10 district hospitals in a single country. Consistent and high correlations calculated from the field testing within the present analysis suggest that the WHO Tool for Situational Analysis is a reliable tool where it measures structure and setting, but it should be revised for measuring process of care

    Two Years Later: Journals Are Not Yet Enforcing the ARRIVE Guidelines on Reporting Standards for Pre-Clinical Animal Studies

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    There is growing concern that poor experimental design and lack of transparent reporting contribute to the frequent failure of pre-clinical animal studies to translate into treatments for human disease. In 2010, the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines were introduced to help improve reporting standards. They were published in PLOS Biology and endorsed by funding agencies and publishers and their journals, including PLOS, Nature research journals, and other top-tier journals. Yet our analysis of papers published in PLOS and Nature journals indicates that there has been very little improvement in reporting standards since then. This suggests that authors, referees, and editors generally are ignoring guidelines, and the editorial endorsement is yet to be effectively implemented

    The Holy Grail: A road map for unlocking the climate record stored within Mars' polar layered deposits

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    In its polar layered deposits (PLD), Mars possesses a record of its recent climate, analogous to terrestrial ice sheets containing climate records on Earth. Each PLD is greater than 2 ​km thick and contains thousands of layers, each containing information on the climatic and atmospheric state during its deposition, creating a climate archive. With detailed measurements of layer composition, it may be possible to extract age, accumulation rates, atmospheric conditions, and surface activity at the time of deposition, among other important parameters; gaining the information would allow us to “read” the climate record. Because Mars has fewer complicating factors than Earth (e.g. oceans, biology, and human-modified climate), the planet offers a unique opportunity to study the history of a terrestrial planet’s climate, which in turn can teach us about our own planet and the thousands of terrestrial exoplanets waiting to be discovered. During a two-part workshop, the Keck Institute for Space Studies (KISS) hosted 38 Mars scientists and engineers who focused on determining the measurements needed to extract the climate record contained in the PLD. The group converged on four fundamental questions that must be answered with the goal of interpreting the climate record and finding its history based on the climate drivers. The group then proposed numerous measurements in order to answer these questions and detailed a sequence of missions and architecture to complete the measurements. In all, several missions are required, including an orbiter that can characterize the present climate and volatile reservoirs; a static reconnaissance lander capable of characterizing near surface atmospheric processes, annual accumulation, surface properties, and layer formation mechanism in the upper 50 ​cm of the PLD; a network of SmallSat landers focused on meteorology for ground truth of the low-altitude orbiter data; and finally, a second landed platform to access ~500 ​m of layers to measure layer variability through time. This mission architecture, with two landers, would meet the science goals and is designed to save costs compared to a single very capable landed mission. The rationale for this plan is presented below. In this paper we discuss numerous aspects, including our motivation, background of polar science, the climate science that drives polar layer formation, modeling of the atmosphere and climate to create hypotheses for what the layers mean, and terrestrial analogs to climatological studies. Finally, we present a list of measurements and missions required to answer the four major questions and read the climate record. 1. What are present and past fluxes of volatiles, dust, and other materials into and out of the polar regions? 2. How do orbital forcing and exchange with other reservoirs affect those fluxes? 3. What chemical and physical processes form and modify layers? 4. What is the timespan, completeness, and temporal resolution of the climate history recorded in the PLD
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