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The current point-of-care ultrasound (POCUS) assessment of gastric fluid volume primarily relies on the traditional linear approach, which often suffers from moderate accuracy. This study aimed to develop an advanced machine learning (ML) model to estimate gastric fluid volume more accurately. We retrospectively analyzed the clinical data and POCUS data (D1: craniocaudal diameter, D2: anteroposterior diameter) of 1386 patients undergoing elective sedated gastrointestinal endoscopy (GIE) at Nanjing First Hospital to predict gastric fluid volume using ML techniques, including six different ML models and a stacking model. We evaluated the models using the adjusted Coefficient of Determination (R2), mean absolute error (MAE) and root mean square error (RMSE). The SHapley Additive exPlanations (SHAP) method was used to interpret the importance of the variables. Finally, a web calculator was constructed to facilitate its clinical application. The stacking model (Linear regression + Multilayer perceptron) performed best, with the highest adjusted R2 of 0.718 (0.632 to 0.804). The mean prediction bias was 4 ml (MAE: 4.008 (3.68 to 4.336)), which is better than that of the linear model. D1 and D2 ranked high in the SHAP plot and performed better in the right lateral decubitus (RLD) than in the supine position. The web calculator can be accessed at . The stacking model and its web calculator can serve as practical tools for accurately estimating gastric fluid volume in patients undergoing elective sedated GIE. It is recommended that anesthesiologists measure D1 and D2 in the patient's RLD position. [ABSTRACT FROM AUTHOR]

Assessment of the patient's gastric contents is the key to avoiding aspiration incidents, however, there is no effective method to determine whether elective painless gastrointestinal endoscopy (GIE) patients have a full stomach or an empty stomach. And previous studies have shown that preoperative oral carbohydrates (POCs) can improve the discomfort induced by fasting, but there are different perspectives on their safety. This study aimed to develop a convenient, accurate machine learning (ML) model to predict full stomach. And based on the model outcomes, evaluate the safety and comfort improvements of POCs in empty- and full stomach groups. We enrolled 1386 painless GIE patients between October 2022 and January 2023 in Nanjing First Hospital, and 1090 patients without POCs were used to construct five different ML models to identify full stomach. The metrics of discrimination and calibration validated the robustness of the models. For the best-performance model, we further interpreted it through SHapley Additive exPlanations (SHAP) and constructed a web calculator to facilitate clinical use. We evaluated the safety and comfort improvements of POCs by propensity score matching (PSM) in the two groups, respectively. Random Forest (RF) model showed the greatest discrimination with the area under the receiver operating characteristic curve (AUROC) 0.837 [95% confidence interval (CI): 79.1–88.2], F1 71.5%, and best calibration with a Brier score of 15.2%. The web calculator can be visited at . PSM results demonstrated that POCs significantly reduced the full stomach incident in empty stomach group (p < 0.05), but no differences in full stomach group (p > 0.05). Comfort improved in both groups and was more significant in empty stomach group. The developed convenient RF model predicted full stomach with high accuracy and interpretability. POCs were safe and comfortably improved in both groups, with more benefit in empty stomach group. These findings may guide the patients' gastrointestinal preparation. This study is the first model utilizing advanced ML techniques based on multiple clinical variables to identify full stomach. The model is suitable for patient-rich outpatient clinics, primary hospitals, remote regions, and specific clinical settings where POCUS is not available. The developed convenient RF model predicted full stomach with high accuracy and interpretability. The test cohort AUROC was 0.837. We further established an online accessible individualized risk calculator and provided waterfall plots to increase the interpretability of each prediction. The propensity score matching (PSM) showed that preoperative oral carbohydrate (POCs) were safe and comfortably improved in both groups, with more benefit in empty stomach group. These findings may provide information for anesthesiologists to guide patients on POCs. [ABSTRACT FROM AUTHOR]

In this article, garnet-type Y3Al5O12 (YAG) were doped with Mg2+-Si4+ ionic pairs and its effect on the structure and the microwave dielectric properties was investigated. It was revealed that in ceramics Y3MgxAl5-2xSixO12 (x = 0, 0.5, 1.0, 1.5, 2.0), increasing doping concentration decreased the sintering temperature and time for the optimal densification. X-ray diffraction studies showed that the samples are isostructural to Al5Y3O12 garnet. All sample were formed a single phase except for x = 2.0, where a secondary peak was detected. Excellent microwave dielectric properties of εr = 10.56, Q × f = 67,571 GHz and τf = -35.23 ppm/°C were obtained for Y3Mg0.5Al4Si0.5O12 ceramics sintered at 1625 °C for 5 h. The factors influencing the microwave dielectric properties of Y3MgxAl5-2xSixO12 ceramics were further discussed by considering the ionic polarization, packing fraction, average grain size and chemical bond valence theory. [ABSTRACT FROM AUTHOR]

In this study, MgxY3-xAl5-xSixO12 (x = 0–0.6) ceramics were prepared via a high-temperature solid state method. Mg2+ and Si4+ replacing Y3+ ions at A-site and Al3+ at C-site in garnet-type Y3Al5O12 (YAG) ceramics were designed to discuss the effects of crystal structure, microstructure on microwave dielectric properties for the first time. Liquid phase sintering induced by doping of Mg2+-Si4+, significantly decreased the sintering temperature and time for the densification of YAG ceramics. X-ray diffraction of the samples showed single phase for x ≤ 0.5, while a secondary phase of MgAl2O4 formed for x = 0.6. From the Rietveld analysis, a decrease in lattice dimensions, bond length and valence and rattling effect were observed, while Raman results showed a change in FWHM of the Eg mode. Based on these parameters, a structure–property relation was developed for MgxY3-xAl5-xSixO12 ceramics. Specially, Mg0.1Y2.9Al4.9Si0.1O12 showed a good set of microwave dielectric properties sintered at 1575 °C for 4 h with εr = 10.67, Q × f = 58,799 GHz, τf = -29.5 ppm/°C. [ABSTRACT FROM AUTHOR]

Ma, M.; Cheng, D., and Kou, Q., 2019. Electromagnetic interference source test system for marine power electronic rectifier. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 704–710. Coconut Creek (Florida), ISSN 0749-0208. In order to improve that testing performance of the electromagnetic interference source of the ship power electronic rectification device, the electromagnetic interference source test system of the ship power electronic rectification device is designed, the design method of electromagnetic interference source test system for ship power electronic rectifier based on discrete distributed ADSP-BF537 logic control and pattern recognition is presented. The invention relates to a local bus control method for an electromagnetic interference source test system of a ship electric power electronic rectification device, which is composed of a ship power electronic rectification module, a bus control module, a modulation and demodulation module, an upper computer information transmission module and an automatic identification module, the invention adopts the ISA/EISA/ Micro Channel expansion bus to carry out the command loading of the electromagnetic interference source test of the ship electric power electronic rectifying device, and combines the discrete distributed control method to carry out the high-precision identification and the program compilation of the electromagnetic interference source test of the ship power electronic rectification device, and adopts the logic ADSP-BF537 as the core processor, the instruction read-write and the compiling operation of the electromagnetic interference source test system of the ship power electronic rectification device are carried out. In that ARM embed microprocessor environment, the hardware module design and the bus development of the electromagnetic interference source test system of the ship power electronic rectification device are carry out, an internal clock oscillator is designed, and the protection performance of the electromagnetic interference source test system of the ship power electronic rectification device is improved. The results of the system test show that the reliability of the electromagnetic interference source test is good, the precision of the automatic control is high, and the self-adaptive judgment of the electromagnetic interference source test of the ship power electronic rectifier is improved. [ABSTRACT FROM AUTHOR]