Quality of life, symptoms and treatment satisfaction in patients with aortic aneurysm using new abdominal aortic aneurysm-specific patient-reported outcome measures.

BACKGROUND: The aim of this study was to present preliminary data on quality of life (QoL), symptoms and treatment satisfaction gathered using three new abdominal aortic aneurysm (AAA)-specific patient-reported outcome measures (PROMs). METHODS: Patients with AAA were recruited from five National Health Service Trusts to complete the three new PROMs: the AneurysmDQoL, AneurysmSRQ and AneurysmTSQ. Patients were either under surveillance or had undergone AAA repair (open or endovascular) during the preceding 24 months. Data were initially collected as part of a study assessing the psychometric properties of the new measures, before being used in the observational analysis of outcomes presented here. RESULTS: Results, although largely non-significant, showed interesting trends. The impact of AAA repair on QoL appeared to worsen progressively after open repair (OR) and improve progressively after endovascular aneurysm repair (EVAR). Conversely, symptoms seemed to become progressively worse after EVAR and progressively better after OR. Information and understanding were key sources of dissatisfaction before the intervention, whereas postoperative dissatisfaction was related to bother from symptoms, follow-up and feedback about scan results. CONCLUSION: Although a larger, prospective data set is necessary to explore outcomes more fully with the new AAA-specific PROMs, the observational data presented here suggest there may be clinically important differences in the symptoms, impact on QoL and treatment satisfaction associated with OR and EVAR

A new fabrication method for precision antenna reflectors for space flight and ground test

Communications satellites are using increasingly higher frequencies that require increasingly precise antenna reflectors for use in space. Traditional industry fabrication methods for space antenna reflectors employ successive modeling techniques using high- and low-temperature molds for reflector face sheets and then a final fit-up of the completed honeycomb sandwich panel antenna reflector to a master pattern. However, as new missions are planned at much higher frequencies, greater accuracies will be necessary than are achievable using these present methods. A new approach for the fabrication of ground-test solid-surface antenna reflectors is to build a rigid support structure with an easy-to-machine surface. This surface is subsequently machined to the desired reflector contour and coated with a radio-frequency-reflective surface. This method was used to fabricate a 2.7-m-diameter ground-test antenna reflector to an accuracy of better than 0.013 mm (0.0005 in.) rms. A similar reflector for use on spacecraft would be constructed in a similar manner but with space-qualified materials. The design, analysis, and fabrication of the 2.7-m-diameter precision antenna reflector for antenna ground tests and the extension of this technology to precision, space-based antenna reflectors are described

Structural design of a vertical antenna boresight 18.3 by 18.3-m planar near-field antenna measurement system

A large very precise near-field planar scanner was proposed for NASA Lewis Research Center. This scanner would permit near-field measurements over a horizontal scan plane measuring 18.3 m by 18.3 m. Large aperture antennas mounted with antenna boresight vertical could be tested up to 60 GHz. When such a large near field scanner is used for pattern testing, the antenna or antenna system under test does not have to be moved. Hence, such antennas and antenna systems can be positioned and supported to simulate configuration in zero g. Thus, very large and heavy machinery that would be needed to accurately move the antennas are avoided. A preliminary investigation was undertaken to address the mechanical design of such a challenging near-field antenna scanner. The configuration, structural design and results of a parametric NASTRAN structural optimization analysis are contained. Further, the resulting design was dynamically analyzed in order to provide resonant frequency information to the scanner mechanical drive system designers. If other large near field scanners of comparable dimensions are to be constructed, the information can be used for design optimization of these also

Chamber shape effects on combustion instability

Rocket combustor shape effects on combustion instabilit

Hardware development for the surface tension driven convection experiment aboard the USML-1 spacelab mission

The Surface Tension Driven Convection Experiment is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the USML-1 Spacelab mission planned for March 1992. Hardware is under development to establish the experimental conditions and perform the specified measurements, for both ground based research and the flight experiment in a Spacelab single rack. Major development areas include an infrared thermal imaging system for surface temperature measurement, a CO2 laser and control system for surface heating, and for flow visualization, a He-Ne laser and optical system in conjunction with an intensified video camera. For ground based work the components of each system were purchased or designed, and tested individually. The three systems will be interfaced with the balance of the experimental hardware and will constitute a working engineering model. A description of the three systems and examples of the component performance is given along with the plans for the development of flight hardware

Frequency and type of interval adverse events during the waiting period to complex aortic endovascular repair

Objective: The aim of the present study was to evaluate the frequency and type of adverse events that can occur during the waiting period to complex aortic endovascular repair. Methods: We performed a retrospective study of all elective patients with complex aortic aneurysms (including pararenal, suprarenal, thoracoabdominal, and aortic arch aneurysms) that had required a custom-made device (CMD) from Cook Medical (Bloomington, Ind) at a tertiary referral vascular center (November 2010 to May 2020). The waiting period was defined as the interval between the date of the stent-graft order and the date of the procedure or cancellation. Interval adverse events were defined as any event that had occurred during the waiting period and led to either mortality, aneurysm rupture, or cancellation of the planned procedure. Results: A total of 235 patients (mean age, 72 years; 25% female) had had a CMD graft ordered (201 planned as a single-stage procedure). The median waiting time until surgery was 106 days (interquartile range [IQR], 77-146 days) in the whole cohort and 101 days (IQR, 77-140 days) for the single-stage cohort. The planned procedure was performed electively in 219 patients (93%), with an overall 30-day elective mortality of 2% (n = 5). A total of 16 interval adverse events occurred during the waiting period. Of these 16 events, 10 were aneurysm ruptures and 6 were cancellations of the procedure owing to non–aneurysm-related deaths (3% of the entire cohort). A total of 10 interval deaths were registered (4.2%), 4 of which were aneurysm related. The risk of rupture during the waiting period (Kaplan-Meier) was 6.1% ± 2.3% at 180 days. The median interval from the stent-graft order to aneurysm rupture was 101 days (IQR, 54-200 days). Of the 10 aneurysm ruptures that had occurred, 6 had undergone emergent repair, with 0% mortality at 30 days (one open repair, one t-Branch, one physician-modified endograft, two cases for which the CMD was already available, one case for which a different CMD was available). Conclusions: The median waiting time from the stent-graft order to implantation was ∼15 weeks. During this waiting period, a substantial proportion of patients could experience adverse events, either related to aneurysm rupture or underlying comorbidities. The risk of rupture during the waiting period exceeded the risk of perioperative mortality. Thus, efforts to decrease this risk could significantly improve the outcomes. A combination of different techniques might play a vital role in reducing the mortality after cases of interval rupture

Disease Control and Biosecurity Measures on Specialized Beef Rearing Units in Sweden

The aim of this study was to investigate and evaluate how biosecurity measures are implemented on Swedish farms with specialized beef production. In Swedish specialized beef production young calves are purchased for intensive rearing, mainly from dairy farms. The calves can be as young as two weeks old. They are reared and later sent to slaughter, and will be classified either as calves (about 8-11 months of age) or as young stock (bulls, heifers and steers older than 11 months). A large part of these beef producing herds purchase calves from many different farms, often through farm-to-farm agreements or through slaughterhouse agents. The agents collect young calves from different farms and thereafter sell and deliver them to specialized beef producers. Since the calves are very young and are mixed with calves from different farms there is a high risk of disease outbreaks. As in many parts of the world the two biggest health issues for calves are enteric and respiratory diseases, common disease pathogens are bovine Corona Virus (BCV), Cryptosporidium parvum (C. Parvum) and bovine respiratory syncytial virus (BRSV). Disease introduction and outbreaks can be prevented through different preventive measures, i.e. biosecurity. The implementation of biosecurity is a common practice in the pig and poultry industry, but not as widespread in the cattle production. The actual extent in Sweden is not known and this study was therefore undertaken. A questionnaire on biosecurity measures was sent to a random sample of 200 farms with specialized beef production, and 100 replied. In addition, face-to-face interviews were made with two slaughterhouse agents and one person responsible for courses needed for authorization of animal transports. The results showed that farmers at specialized beef rearing units perform few biosecurity measures; the majority performed rodent and bird control, participated in the voluntary salmonella program and swept the feed area. Larger herds performed more biosecurity measures compared to smaller farms. According to the participating farms not a large proportion of the calves expressed signs of diarrhea and pneumonia, but diarrhea is usually more common among younger calves than older ones and the age of the purchased calves varies between these herds. There was also a significant association between performing biosecurity measures and cases of diarrhea in the quarantine barn, less cases of diarrhea when implementing biosecurity but not a significant association between pneumonia and biosecurity. When interviewing slaughterhouse agents it seemed possible to implement a “health declaration” program for BRSV-calves in Sweden, similar to the previous BVDV-program. This might motivate specialized beef producers (and dairy herds) to improve their biosecurity. Nonetheless, there is room for an improvement of biosecurity in the Swedish specialized beef industry