We report improved sensitivity to NO, NO₂ and NH₃ gas with specially-designed AlGaN/GaN high electron mobility transistors (HEMT) that are suitable for operation in the harsh environment of diesel exhaust systems. The gate of the HEMT device is functionalized using a Pt catalyst for gas detection. We found that the performance of the sensors is enhanced at a temperature of 600 °C, and the measured sensitivity to 900 ppm-NO, 900 ppm-NO₂ and 15 ppm-NH₃ is 24%, 38.5% and 33%, respectively, at 600 °C. We also report dynamic response times as fast as 1 s for these three gases. Together, these results indicate that HEMT sensors could be used in a harsh environment with the ability to control an anti-pollution system in real time.
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http://dx.doi.org/10.3390/s16030273 | DOI Listing |
Curr Probl Diagn Radiol
April 2024
Radiology Service, VA Palo Alto Health Care System, Palo Alto, CA, USA; Department of Radiology, Stanford University, Stanford, CA, USA. Electronic address:
Background: Early detection of abdominal aortic aneurysms (AAAs) is critical given the high morbidity and mortality of a ruptured aneurysm. Screening ultrasound is recommended for men 65 and 75 years of age with a smoking history. However, studies have shown that the rate of ultrasound screening is low and that implicit AAA screening by abdominal imaging studies that were not originally intended for AAA screening can play a major role in AAA detection.
View Article and Find Full Text PDFNPJ Biofilms Microbiomes
December 2021
Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA.
Work on marine biofilms has primarily focused on host-associated habitats for their roles in larval recruitment and disease dynamics; little is known about the factors regulating the composition of reef environmental biofilms. To contrast the roles of succession, benthic communities and nutrients in structuring marine biofilms, we surveyed bacteria communities in biofilms through a six-week succession in aquaria containing macroalgae, coral, or reef sand factorially crossed with three levels of continuous nutrient enrichment. Our findings demonstrate how biofilm successional trajectories diverge from temporal dynamics of the bacterioplankton and how biofilms are structured by the surrounding benthic organisms and nutrient enrichment.
View Article and Find Full Text PDFAnn Vasc Surg
July 2021
Division of Cardiology, Rocky Mountain Regional VA Medical Center, University of Colorado, Denver, CO. Electronic address:
Background-objective: Prior studies have suggested a higher prevalence of simple renal cysts (SRC) among patients with aortic disease, including abdominal aortic aneurysms (AAA). Thus, the aim of this study was to systematically review all currently available literature and investigate whether patients with AAA are more likely to have SRC.
Methods: This study was performed according to the PRISMA guidelines.
Br J Surg
February 2018
Department of Cardiovascular Sciences and National Institute for Health Research Leicester Biomedical Research Unit, University of Leicester, Leicester Royal Infirmary, Leicester, UK.
Background: Screening for abdominal aortic aneurysm (AAA) is known to reduce AAA-related mortality; however, the psychological impact of population AAA screening is unclear. The aim was to assess the impact of AAA diagnosis on quality of life (QoL) using data from an established AAA screening programme.
Methods: Mental and physical QoL scores for men diagnosed with AAA through participation in the English and Welsh AAA screening programmes were compared with no-AAA controls.
Cardiovasc Pathol
December 2014
Institute for Medical Research-IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel. Electronic address:
Introduction: Infusion of angiotensin-II (Ang-II) in apolipoprotein-E-deficient mice (Apo-E(-/-)) results in suprarenal abdominal aortic aneurysm (AAA) in 30-85% of cases. This study identifies the apparent mechanism by which some animals do, but others do not, develop AAA in this model.
Methods: Male Apo-E(-/-) mice were infused with Ang-II (n=21) or saline (n=6) and sacrificed at 4 weeks.
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