Background Painless gastrointestinal endoscopy is widely used for the diagnosis and treatment of digestive diseases. At present, propofol is commonly used to perform painless gastrointestinal endoscopy, but the high dose of propofol often leads to a higher incidence of cardiovascular and respiratory complications. Studies have shown that the application of propofol combined with ketamine in painless gastrointestinal endoscopy is beneficial to reduce the dosage of propofol and the incidence of related complications. Esketamine is dextrorotatory structure of ketamine with a twice as great anesthetic effect as normal ketamine but fewer side effects. We hypothesized that esketamine may reduce the consumption of propofol and to investigate the safety of coadministration during gastrointestinal endoscopy. Methods A total of 260 patients undergoing painless gastrointestinal endoscopy (gastroscope and colonoscopy) were randomly divided into P group (propofol + saline), PK1 group (propofol + esketamine 0.05 mg/kg), PK2 group (propofol + esketamine 0.1 mg/kg), and PK3 group (propofol + esketamine 0.2 mg/kg). Anesthesia was achieved by 1.5 mg/kg propofol with different doses of esketamine. Propofol consumption per minute was recorded. Hemodynamic index, pulse oxygen saturation, operative time, induction time, awakening status, orientation recovery time, adverse events, and Mini-Mental State Examination (MMSE) were also recorded during gastrointestinal endoscopy. Results Propofol consumption per minute was 11.78, 10.56, 10.14, and 9.57 (mg/min) in groups P, PK1, PK2, and PK3, respectively; compared with group P, groups PK2 and PK3 showed a decrease of 13.92% (P = 0.021) and 18.76% (P = 0.000), respectively. In all four groups, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), but not pulse oxygen saturation (SpO2) significantly decreased (P = 0.000) immediately after administration of induction, but there were no significant differences between the groups. The induction time of groups P, PK1, PK2, and PK3 was 68.52 ± 18.394, 64.83 ± 13.543, 62.23 ± 15.197, and 61.35 ± 14.470 s, respectively (P = 0.041). Adverse events and psychotomimetic effects were observed but without significant differences between the groups. Conclusions The combination of 0.2 mg/kg esketamine and propofol was effective and safe in painless gastrointestinal endoscopy as evidenced by less propofol consumption per minute, shorter induction time, and lower incidence of cough and body movement relative to propofol alone. The lack of significant differences in hemodynamic results, anesthesia-related indices, adverse events, and MMSE results showed the safety to apply this combination for painless gastrointestinal endoscopy. Trial registration This study was registered with China Clinical Trial Registration on 07/11/2020 (registration website: chictr.org.cn; registration numbers: ChiCTR https://clinicaltrials.gov/ct2/show/2000039750).

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In resource limited mobile computing devices (wireless sensor networks), energy saving is a critical design task. However, existing wake-up mechanisms encounter a critical trade-off between energy consumption and response time.In this paper, we propose a passive RF wake up (PRFW) scheme instead of time-based scheme to wake up node that indeed needs to wake up. The PRFW scheme is enabled by a PRFW hardware module sensing radio signal from other nodes. Analysis of energy consumption and delay shows that the power saving capability and wake-up delay can be improved by using the PRFW scheme.

In this paper we describe a semianalytical approach to computing the temperature and thermal stress inside a III-V compound grown with the Czochralski technique. An analysis of the growing conditions indicates that the crystal growth occurs on the conductive time scale. A perturbation method for the temperature field is developed for an arbitrary crystal profile using the Biot number as a (small) expansion parameter. The zeroth order solution is one-dimensional in the axial direction. Explicit solutions are obtained for a cylindrical and a conical crystal. Under typical growth conditions, a parabolic temperature profile in the radial direction is shown to arise naturally as the first order correction. As a result, the thermal stress is obtained explicitly and its magnitude is shown to depend on the zeroth order temperature and Biot number. Both the axial temperature gradient and crystal profile are shown to be important for controlling thermal stress and defect density. Some issues relevant to growth conditions are also discussed.

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