602 research outputs found
4-Bit Microprocessor: Design, Simulation, Fabrication, and Testing
The work presented demonstrates the unique ability of Rochester Institute of Technology’s Microelectronic Engineering department to design, simulate, fabricate, and test complex digital integrated circuits. Utilizing the resources available, the author would be the first undergraduate at RIT to successfully drive the creation of a microprocessor from design through fabrication to test. The microprocessor created is the most complex digital circuit ever fabricated at RIT. Fabrication was completed on three lots using the well-established RIT sub μm CMOS Process. Functional CMOS transistors were demonstrated at the Metal 1 level, but complex digital integrated circuits were not realized beyond that
Awareness and bispectral index (BIS) monitoring in mechanically ventilated patients in the emergency department and intensive care unit: A systematic review protocol
INTRODUCTION: Accidental awareness with recall is one of the most feared complications for patients undergoing general anaesthesia and can lead to post-traumatic stress disorder in up to 70% of patients experiencing it. To reduce the incidence of awareness with recall, the bispectral index monitor is recommended for patients receiving total intravenous anaesthetics, especially those receiving neuromuscular blockers. While extensive investigation into awareness and bispectral index monitoring has occurred for operating room patients, this has not extended to other clinical arenas where sedated and mechanically ventilated patients are cared for, namely the intensive care unit and emergency department. The purpose of this systematic review is to assess the world\u27s literature to determine the incidence of awareness with paralysis in mechanically ventilated patients and the impact of bispectral index monitoring for reducing this complication.
METHODS AND ANALYSIS: Randomised trials and non-randomised studies are eligible for inclusion. With aid from a medical librarian, an electronic search will include Ovid Medline, Embase.com, Scopus, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. To find data published in abstract form, literature from professional society conferences (2010-2019) will be manually searched. Two authors will independently review search results and consensus will be reached with assistance from a third author, as needed. Heterogeneity and publication bias will be assessed and reported. If possible and appropriate, a meta-analysis of the data will be conducted for quantitative data analysis.
ETHICS AND DISSEMINATION: The proposed systematic review does not require ethical approval, as it is conducted at the study level and does not involve individual patient-level data. Results will be disseminated by data sharing via academically established means, presentation at local and national scientific meetings and publication as a peer-reviewed manuscript.
PROSPERO REGISTRATION NUMBER: The protocol has been submitted to International Prospective Register of Systematic Reviews and is awaiting registration
Long-term Evolution and Appearance of Type Iax Postgenitor Stars
Type Iax supernovae may arise from failed explosions of white dwarfs (WDs) that leave behind a bound remnant (i.e., a "postgenitor" star) that could be identified in wide field surveys. To understand their observational signatures, we simulate these WD postgenitors from shortly after explosion until they move back down the WD cooling track, and we consider several possible WD masses and explosion energies. To predict the peculiar surface abundances of the WD postgenitors, our models take into account gravitational settling and radiative levitation. We find that radiative levitation is significant at temperatures above a mass-dependent critical temperature, typically in the range T_(eff) ≈ (50–100) × 10^3 K, significantly increasing surface abundances of iron group elements. Due to enhanced iron group opacity compared to normal WDs, the postgenitor peak luminosity and cooling timescale depend sensitively on mass, with more massive WDs becoming brighter but cooling much faster. We discuss our results in light of recently discovered hypervelocity WDs with peculiar surface compositions, finding that our low-mass postgenitor models match many of their observational characteristics. Finally, we explore the effects of thermohaline diffusion, tentatively finding that it strongly suppresses abundance enhancements created by radiative levitation, but more realistic modeling is required to reach a firm conclusion
Disease prevention versus data privacy : using landcover maps to inform spatial epidemic models
The availability of epidemiological data in the early stages of an outbreak of an infectious disease is vital for modelers to make accurate predictions regarding the likely spread of disease and preferred intervention strategies. However, in some countries, the necessary demographic data are only available at an aggregate scale. We investigated the ability of models of livestock infectious diseases to predict epidemic spread and obtain optimal control policies in the event of imperfect, aggregated data. Taking a geographic information approach, we used land cover data to predict UK farm locations and investigated the influence of using these synthetic location data sets upon epidemiological predictions in the event of an outbreak of foot-and-mouth disease. When broadly classified land cover data were used to create synthetic farm locations, model predictions deviated significantly from those simulated on true data. However, when more resolved subclass land use data were used, moderate to highly accurate predictions of epidemic size, duration and optimal vaccination and ring culling strategies were obtained. This suggests that a geographic information approach may be useful where individual farm-level data are not available, to allow predictive analyses to be carried out regarding the likely spread of disease. This method can also be used for contingency planning in collaboration with policy makers to determine preferred control strategies in the event of a future outbreak of infectious disease in livestock
Aura Microwave Limb Sounder Observations of Dynamics and Transport During the Record-Breaking 2009 Arctic Stratospheric Major Warming
A major stratospheric sudden warming (SSW) in January 2009 was the strongest and most prolonged on record. Aura Microwave Limb Sounder (MLS) observations are used to provide an overview of dynamics and transport during the 2009 SSW, and to compare with the intense, long-lasting SSW in January 2006. The Arctic polar vortex split during the 2009 SSW, whereas the 2006 SSW was a vortex displacement event. Winds reversed to easterly more rapidly and reverted to westerly more slowly in 2009 than in 2006. More mixing of trace gases out of the vortex during the decay of the vortex fragments, and less before the fulfillment of major SSW criteria, was seen in 2009 than in 2006; persistent well-defined fragments of vortex and anticyclone air were more prevalent in 2009. The 2009 SSW had a more profound impact on the lower stratosphere than any previously observed SSW, with no significant recovery of the vortex in that region. The stratopause breakdown and subsequent reformation at very high altitude, accompanied by enhanced descent into a rapidly strengthening upper stratospheric vortex, were similar in 2009 and 2006. Many differences between 2006 and 2009 appear to be related to the different character of the SSWs in the two years
A study protocol for a multicentre, prospective, before-and-after trial evaluating the feasibility of implementing targeted SEDation after initiation of mechanical ventilation in the emergency department (The ED-SED Pilot Trial)
INTRODUCTION: Sedation is a cornerstone therapy in the management of patients receiving mechanical ventilation and is highly influential on outcome. Early sedation depth appears especially influential, as early deep sedation is associated with worse outcome when compared with light sedation. Our research group has shown that patients receiving mechanical ventilation in the emergency department (ED) are exposed to deep sedation commonly, and ED sedation depth is impactful on intensive care unit (ICU) care and clinical outcomes. While extensive investigation has occurred for patients in the ICU, comparatively little data exist from the ED. Given the influence that ED sedation seems to carry, as well as a lack of ED-based sedation trials, there is significant rationale to investigate ED-based sedation as a means to improve outcome.
METHODS AND ANALYSIS: This is a multicentre (n=3) prospective, before-and-after pilot trial examining the feasibility of implementing targeted sedation in the immediate postintubation period in the ED. A cohort of 344 patients receiving mechanical ventilation in ED will be included. Feasibility outcomes include: (1) participant recruitment; (2) proportion of Richmond Agitation-Sedation Scale (RASS) scores in the deep sedation range; (3) reliability (agreement) of RASS measurements performed by bedside ED nurses; and (4) adverse events. The proportion of deep sedation measurements before and after the intervention will be compared using the χ
ETHICS AND DISSEMINATION: The Human Research Protection Office at Washington University in St. Louis School of Medicine has approved the study. The publication of peer-reviewed manuscripts and the presentation of abstracts at scientific meetings will be used to disseminate the work.
REGISTRATION: ClinicalTrials.gov identifier NCT04410783; Pre-results
Awareness with paralysis and symptoms of post-traumatic stress disorder among mechanically ventilated emergency department survivors (ED-AWARENESS-2 Trial): study protocol for a pragmatic, multicenter, stepped wedge cluster randomized trial.
BACKGROUND: Awareness with paralysis (AWP) is memory recall during neuromuscular blockade (NMB) and can cause significant psychological harm. Decades of effort and rigorous trials have been conducted to prevent AWP in the operating room, where prevalence is 0.1-0.2%. By contrast, AWP in mechanically ventilated emergency department (ED) patients is common, with estimated prevalence of 3.3-7.4% among survivors given NMB. Longer-acting NMB use is a critical risk for AWP, and we have shown an association between ED rocuronium use and increased AWP prevalence. As NMB are given to more than 90% of ED patients during tracheal intubation, this trial provides a platform to test an intervention aimed at reducing AWP. The overall objective is to test the hypothesis that limiting ED rocuronium exposure will significantly reduce the proportion of patients experiencing AWP.
METHODS: This is a pragmatic, stepped wedge cluster randomized trial conducted in five academic EDs, and will enroll 3090 patients. Per the design, all sites begin in a control phase, under observational conditions. At 6-month intervals, sites sequentially enter a 2-month transition phase, during which we will implement the multifaceted intervention, which will rely on use of nudges and defaults to change clinician decisions regarding ED NMB use. During the intervention phase, succinylcholine will be the default NMB over rocuronium. The primary outcome is AWP, assessed with the modified Brice questionnaire, adjudicated by three independent, blinded experts. The secondary outcome is the proportion of patients developing clinically significant symptoms of post-traumatic stress disorder at 30 and 180 days after hospital discharge. We will also assess for symptoms of depression and anxiety, and health-related quality of life. A generalized linear model, adjusted for time and cluster interactions, will be used to compare AWP in control versus intervention phases, analyzed by intention-to-treat.
DISCUSSION: The ED-AWARENESS-2 Trial will be the first ED-based trial aimed at preventing AWP, a critical threat to patient safety. Results could shape clinical use of NMB in the ED and prevent more than 10,000 annual cases of AWP related to ED care.
TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05534243 . Registered 06, September 2022
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