81 research outputs found
Association between aspirin and mortality in critically ill patients with atrial fibrillation: a retrospective cohort study based on mimic-IV database
BackgroundAtrial fibrillation (AF) is a prevalent issue among critically ill patients, and the availability of effective treatment strategies for AF is limited.AimThe objective of this study was to evaluate the mortality rate associated with AF in critically ill patients who were either aspirin or non-aspirin users.MethodsThis cohort study incorporated critically ill patients with AF from the Medical Information Mart for Intensive Care database. The study compared incidences of 28-day mortality, 90-day mortality, and 1-year mortality between patients with and without aspirin prescriptions. To assess the association between aspirin and the endpoints, Kaplan-Meier analysis and Cox proportional hazards regression analyses were conducted.ResultsIn this study, a total of 13,330 critically ill patients with atrial fibrillation (AF) were included, of which 4,421 and 8,909 patients were categorized as aspirin and non-aspirin users, respectively. The 28-day, 90-day, and 1-year mortality rates were found to be 17.5% (2,330/13,330), 23.9% (3,180/13,330), and 32.9% (4,379/13,330), respectively. The results of a fully-adjusted Cox proportional hazard model indicated that aspirin use was negatively associated with the risk of death after adjusting for confounding factors (28-day mortality, HR 0.64, 95% CI 0.55â0.74; 90-day mortality, HR 0.65, 95% CI 0.58â0.74; 1-year mortality, HR 0.67, 95%CI 0.6âŒ0.74). The results of the subgroup analysis indicate a more robust correlation, specifically among patients under the age of 65 and those without a history of congestive heart failure or myocardial infarction.ConclusionsThe utilization of aspirin may exhibit a correlation with a reduction in risk-adjusted mortality from all causes in critically ill patients diagnosed with atrial fibrillation. However, additional randomized controlled trials are necessary to elucidate and confirm this potential association
Manometric Measurement of the Sphincter of Oddi in Patients with Common Bile Duct Stones: A Consecutive Study of the Han Population of China
Objective. Role of dysfunction of the sphincter of Oddi (SO) in choledocholithiasis is controversial. This study was to evaluate SO motor activity in patients with common bile duct (CBD) stones in the Han population of China. Patients and Methods. In this study, 76 patients with CBD stones were enrolled in a single tertiary endoscopy center. Data of SO motor activities was prospectively evaluated by endoscopic manometry. Mean basal SO pressure, amplitude, and frequency were collected and analyzed. Results. The mean basal SO pressure, amplitude, and frequency were 52.7±40.0 (1.60â171.1)âmmHg, 39.9±19.7 (14.9â115.5)âmmHg, and 5.7±3.2 (1.3â13.8)/min, respectively. The basal SO pressure was higher in patients with CBD stones < 10âmm in diameter than that in those with CBD stones larger than 10âmm in diameter (60.7±41.0âmmHg versus 36.8±29.4âmmHg, P=0.043). There was no significant difference in the basal SO pressure, amplitude, and frequency when compared with the CBD diameter, CBD stone number, prior cholecystectomy, periampullary diverticula, and symptoms. Levels of alanine aminotransferase, aspartate transaminase, Îł-glutamyl transpeptidase, and alkaline phosphatase showed no significant difference in patients with normal or elevated basal SO pressure. Conclusion. These results identify that, in Chinese Han population, abnormalities of SO motor activity are associated with CBD stones
Dynamics of Water Vapor Content around Isolated Sprinklers: Description and Validation of Model
Irrigation consumes considerable water to satisfy the current food demand. An improvement in water use efficiency for irrigation is essential. Wind drift and evaporation losses reduce the water use efficiency of center pivot irrigation systems in arid and semi-arid areas. In this paper, a model of water vapor dynamics during and after overhead sprinkler irrigation was developed and validated by experimental data using a center pivot simulator and a water vapor measuring system. The model was represented as an exponential equation during irrigation and a logistic equation after irrigation. The water vapor dynamics measured next to and 2 m from the sprinkler were well-fitted with the developed model. Model performance was good according to evaluations of the NashâSutcliffe efficiency coefficient, with values of 0.961 and 0.934 for estimations next to the sprinkler and 2 m from the sprinkler, respectively. Results showed that both modeled and observed water vapor dynamics increased rapidly as irrigation started, and then leveled off to maximum values. After irrigation, the water vapor dynamics started to decrease gradually, and eventually decreased rapidly. The decreasing rate stopped when the water vapor content was restored to the level of the surrounding atmosphere. The model parameters showed that the maximum increases in water vapor content were from 2.506 to 6.476 g mâ3 for the area next to the sprinkler, and 1.277 to 3.380 g mâ3 for the area 2 m from the sprinkler, under the influence of vapor pressure deficits. The increasing and decreasing rates of the dynamics during and after irrigation were influenced by temperature, relative humidity, and vapor pressure deficits, according to Pearsonâs correlations. A period of 2.3 to 4.0 h was required to restore water vapor to the atmospheric level
Experimental Interharmonic Sensitivity Evaluation of LED Lamps Based on the Luminous Flux Flicker Model
LED lamps have gradually replaced other lighting sources and have become mainstream in the lighting industry. The research on interharmonic sensitivity affecting their lighting quality cannot be ignored. By deconstructing the lamp-eye-brain module in the International Electrotechnical Commission (IEC) flicker model, a luminous flux flicker model without the constraints of a specific light source was proposed. The test system and corresponding analysis method of the interharmonic-luminous flux transfer coefficient in the model were described in detail, and the accuracy of the test results of the system was verified via incandescent lamp heat balance model simulations. Based on the test results, the conversion method of the interharmonic ratio of LED lamps under the flicker limit based on the interharmonic-flicker limit curve of incandescent lamps was deduced. By testing and comparing the differences in interharmonic-flicker limit curves of different driving types of LED lamps, the experimental evaluation of their sensitivity was completed, and the reference for LED lamp selection, driver design, and compatibility standard formulation in different application scenarios was provided
A Rainfall Interception Model for Alfalfa Canopy under Simulated Sprinkler Irrigation
Estimating canopy interception of water by plants during rainfall or sprinkler irrigation is a critical step for evaluating water-use efficiency. Most existing experimental studies and mathematic models of canopy interception have paid little attention to the interception losses of water by herbaceous plants. To better understand the canopy interception processes of herbaceous plants and to estimate the interception losses, a process-based dynamic interception model for alfalfa canopy was developed and validated by an experiment under conditions of simulated sprinkler irrigation. The parameters of the model included the maximum interception, the rate of interception of the alfalfa canopy, and the duration of sprinkler irrigation. The model demonstrated that the amount of interception increased rapidly with duration in the early stage of sprinkler irrigation, and then gradually leveled off until the maximum retention capacity of the canopy was reached. The maximum interception by the alfalfa canopy, ranging from 0.29 to 1.26 mm, increased nonlinearly with the increase of leaf area index (LAI) and sprinkling intensity. The rate of interception increased with the decrease of LAI and the increase of sprinkling intensities. Meanwhile, a nonlinear equation based on sprinkling intensity and plant height was proposed in order to more practically estimate the maximum interception by alfalfa canopy
Experimental Interharmonic Sensitivity Evaluation of LED Lamps Based on the Luminous Flux Flicker Model
LED lamps have gradually replaced other lighting sources and have become mainstream in the lighting industry. The research on interharmonic sensitivity affecting their lighting quality cannot be ignored. By deconstructing the lamp-eye-brain module in the International Electrotechnical Commission (IEC) flicker model, a luminous flux flicker model without the constraints of a specific light source was proposed. The test system and corresponding analysis method of the interharmonic-luminous flux transfer coefficient in the model were described in detail, and the accuracy of the test results of the system was verified via incandescent lamp heat balance model simulations. Based on the test results, the conversion method of the interharmonic ratio of LED lamps under the flicker limit based on the interharmonic-flicker limit curve of incandescent lamps was deduced. By testing and comparing the differences in interharmonic-flicker limit curves of different driving types of LED lamps, the experimental evaluation of their sensitivity was completed, and the reference for LED lamp selection, driver design, and compatibility standard formulation in different application scenarios was provided
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