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Incorporating AC-type flying capacitors (FC) between series-connected devices is an effective way to enhance the rated voltage for high-power applications based on current source converters (CSCs). Through appropriate modulation and FC voltage control, it is possible to achieve improved DC bus voltage quality with reduced common-mode voltage (CMV) and low dv/dt. On the other hand, the parallel CSC is a popular choice for increasing the system's rated current to accommodate higher power applications. The use of interleaved modulation techniques can improve the harmonic performance of parallel converters while reducing the need for passive filters. The modular flying capacitor clamped (FCC)-CSC structure can combine these advantages, achieving higher rated power along with improved power quality on both the DC and AC sides. Moreover, the enhanced AC quality contributes to the regulation of FC voltage and further improves the DC-side voltage quality. This paper analyzes the operation principle of the parallel FCC-CSC structure and proposes an interleaved space vector modulation (SVM) method to enhance the harmonic performance of the AC output. Additionally, an optimized zero-state replacement (ZSR) based FC voltage control and a DC-link current balance strategy built on this control are introduced. Simulation and experimental results validate the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

To improve the performance of the interior permanent magnet synchronous motor control system, a Markov decision model predictive current control strategy based on a lumped disturbances sliding mode disturbance observer is proposed in this paper. A fast terminal sliding mode disturbance observer based on a recursive integral sliding surface is designed to observe and compensate the unideal factors in the motor control system unified as lumped disturbances. Then, according to the characteristic of model predictive control where only the first vector in the optimal control sequence is selected and applied to the system during rolling optimization, the discounted cost criterion based on the Markov decision process is introduced to enhance the control performance of the system. The compensation of lumped disturbances can eliminate the impact of unideal factors, enhance the dynamic performance of the speed loop, and eliminate the static errors in the current loop. The introduction of the discounted cost criterion can reduce the fluctuations in system states without affecting the system's dynamic performance. Moreover, the proposed control strategy does not require the original control structure of the system to be changed. Experiments are carried out to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Urea electrosynthesis from carbon dioxide (CO2) and nitrate (NO3−) is an alternative approach to traditional energy‐intensive urea synthesis technology. Herein, we report a CuAu single‐atom alloy (SAA) with electronic metal support interaction (EMSI), achieving a high urea yield rate of 813.6 μg h−1 mgcat−1 at −0.94 V versus reversible hydrogen electrode (vs. RHE) and a Faradaic efficiency (FE) of 45.2 % at −0.74 V vs. RHE. In situ experiments and theoretical calculations demonstrated that single‐atom Cu sites modulate the adsorption behavior of intermediate species. Bimetallic sites synergistically accelerate C−N bond formation through spontaneous coupling of *CO and *NO to form *ONCO as key intermediates. More importantly, electronic metal support interaction between CuAu SAA and CeO2 carrier further modulates electron structure and interfacial microenvironment, endowing electrocatalysts with superior activity and durability. This work constructs SAA electrocatalysts with EMSI effect to tailor C−N coupling at the atomic level, which can provide guidance for the development of C−N coupling systems. [ABSTRACT FROM AUTHOR]

To overcome the problem of current control effect being reduced by unideal factors in a motor control system, such as motor parameter variation, inverter dead time, nonlinearity of the system, etc., a sliding mode disturbance observer for an interior permanent magnet synchronous motor is proposed in this paper. The model of an interior permanent magnet synchronous motor with unideal factors is designed, and the unideal factors are unified into lumped disturbances of motor stator voltage. Then, the observer for lumped disturbance is designed. A recursive integral sliding surface is used to replace the terminal sliding surface to avoid the noise sensitivity and singularity problem of the traditional terminal sliding mode observer. The observer can estimate the lumped disturbance of the current loop without relying on the accurate system model in finite time. Moreover, the structure of the current loop does not need to be adjusted while using the observer to observe and compensate for disturbances. Experiments are carried out to verify the effectiveness of the proposed observer. [ABSTRACT FROM AUTHOR]

The computer‐aided diagnostic (CAD) method to detect human brain tumors relies heavily on automated tumor characterization. Although CAD method has been extensively researched, significant obstacles still exist. Magnetic resonance imaging (MRI) classifiers brain tumors into glioma, meningioma, and pituitary tumors. However, accurately distinguishing between these tumor types remains a complex challenge in medical imaging. The recently developed deep learning and machine learning (ML) techniques have shown immense potential in image classification. However, the low numbers of medical image archives also pose a problem for medical image classification. As a result, fewer medical images are available to use in deep learning research and development. To address this issue, we use three highly effective ML classifiers with deep convolutional learned features for medical image classification. The MRI images of the three distinct types of brain tumors may be found in an open dataset on Figshare, which tests the automated approach's efficacy. Features are extracted from brain MRI scans using the DenseNet169 model. Extracted features are fed into a multiclass three ML classifiers (RF, SVM, XGBoost) for improved performance. Results from testing and evaluation of the entire framework are promising, especially compared to the field's state‐of‐the art technique. The suggested model outperformed the state‐of‐the‐art technique, with an overall classification accuracy of 95.10%. To verify the enhanced performance of the proposed system, extensive tests are conducted on the brain MRI dataset available on Figshare. The optimal hyper‐parameter fading classifier is seen to outperform the Softmax classifier for the features when there is limited training data. [ABSTRACT FROM AUTHOR]

Objectives: Esketamine is an S (+) enantiomer of ketamine with greater potency and similar psychomimetic effects compared to racemic ketamine. We aimed to explore the safety of esketamine in different doses as an adjuvant to propofol in patients undergoing endoscopic variceal ligation (EVL) with or without injection sclerotherapy. Methods: One hundred patients were randomized to receive sedation with propofol 1.5 mg/kg in combination with sufentanil 0.1 μg/kg (group S), esketamine 0.2 mg/kg (group E0.2), esketamine 0.3 mg/kg (group E0.3), or esketamine 0.4 mg/kg (group E0.4) for EVL (n = 25 each). Hemodynamic and respiratory parameters were recorded during the procedure. The primary outcome was the incidence of hypotension; secondary outcomes included the incidence of desaturation, positive and negative syndrome scale (PANSS) after the procedure, pain score after the procedure, and secretion volume. Results: The incidence of hypotension was significantly lower in groups E0.2 (36%), E0.3 (20%), and E0.4 (24%) than in group S (72%). The incidence of SpO2 ≤94% was significantly lower in group E0.4 (4%) than in group S (32%). No significant intergroup difference was found in the PANSS assessment. Conclusions: Combining 0.4 mg/kg esketamine with propofol sedation was optimal to facilitate EVL with stable hemodynamic status and better respiratory function during the procedure, without significant psychomimetic side‐effects. Trial registration: Chinese Clinical Trial Registry (Trial ID: ChiCTR2100047033, http://www.chictr.org.cn/showproj.aspx?proj=127518). [ABSTRACT FROM AUTHOR]

In order to solve the coordinated optimization problem of distributed generation (DG), on‐load tap changer (OLTC) and capacitor banks, a dynamic reactive power optimization (DRPO) method based on fuzzy time clustering is proposed. In the method, fuzzy time clustering algorithm is used to cluster the static optimal switching sequence of OLTC and capacitor banks. The time decoupling of control variables is realized and it meets the constraints of the maximum switching times. Next, the influencing factors of DG reactive power limit are analysed. Considering the control ability of OLTC, capacitor banks and DG in voltage and reactive power optimization, a coordinated optimization method is proposed. Since the adjustment of OLTC tap position directly affects the voltage and reactive power distribution of the whole line, the switching time and tap position of OLTC are determined based on the static optimization results of each time and fuzzy time clustering algorithm. Then, the switching time of capacitor banks is determined by fuzzy time clustering algorithm. At last, the switching capacity of capacitor banks and DG reactive power are jointly optimized to get the final control scheme. The proposed method demonstrated good performance in the modified IEEE33 node system and two actual power grid examples. [ABSTRACT FROM AUTHOR]

Objective: The diurnal rhythm profile of human basal pain sensitivity and its association with sympathetic nerve activity are not fully understood. This study aimed to examine rhythmic changes in experimental pain sensitivity and skin sympathetic nerve activity in healthy volunteers. Methods: Thirty healthy volunteers were included in the study. Experimental pain sensitivity, including pressure pain threshold and tolerance, cold pain threshold (CPT) and tolerance, skin sympathetic nerve activity, and cardiovascular parameters (including heart rate, cardiac output, and peripheral vascular resistance) at six time points throughout the day (08:00, 12:00, 16:00, 20:00, 00:00, and 04:00) were sequentially measured. Circadian rhythm analysis was performed on the mean values of the different measurements and individual subjects. Results: Significant differences were found in experimental pain sensitivity, skin sympathetic nerve activity, and non-invasive cardiovascular parameters at different time points (P < 0.05). The minimum measured values of all four types of experimental pain sensitivity were consistently observed at 04:00. Rhythmical analysis showed that the mean values of pressure pain threshold (meta2d P = 0.016) and skin sympathetic nerve activity (meta2d P = 0.039) were significant. Significant diurnal rhythms in pain sensitivity and skin sympathetic nerve activity existed in some individuals but not in others. No significant correlation between experimental pain sensitivity and skin sympathetic nerve activity was found at any time point (P > 0.05). Conclusion: Significant diurnal fluctuations were observed in different pain sensitivities and skin sympathetic nerve activity. No significant correlation between experimental pain sensitivity and sympathetic excitability at different times was found; the reasons for these phenomena remain to be further studied. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [ChiCTR2000039709]. [ABSTRACT FROM AUTHOR]

Urea (CO(NH2)2) is the main component of nitrogen‐based fertilizers and is widely used in various industries. Until now, urea production is conducted under high‐temperature and high‐pressure conditions, which involves a considerable carbon footprint. Urea electrosynthesis, which is powered by renewable energy‐derived electricity, has emerged as a sustainable single‐step process for urea production. The development of efficient and stable catalysts is the key to improving the efficiency of urea electrosynthesis. In this review, we summarized the research progress and applications of catalysts with atomic‐scale reactive sites in urea electrosynthesis. First, the catalytic mechanisms of urea electrosynthesis from CO2 and various nitrogenous molecules are discussed. Then, typical electrocatalysts such as single‐atom electrocatalysts, dual‐atom electrocatalysts, clusters, atomic dopants, vacancies, and so forth, are discussed. Furthermore, characterization methods for atomic‐scale reactive sites are summarized. Finally, challenges and suggestions for urea electrosynthesis are proposed. We hope this review can provide some inspiration toward the development of catalysts for efficient and sustainable urea electrosynthesis. [ABSTRACT FROM AUTHOR]

In this paper, resource allocation is studied for a fully sustainable cooperative IoT network, in which a relay powered by renewable energy forwards data to a destination while charging multiple IoT nodes by radio-frequency (RF) signals. An optimal joint time and power allocation problem is formulated to maximize the long-term sum-throughput of IoT nodes, taking into consideration the bounded transmit power of IoT nodes, the stochastic characteristic of energy harvesting (EH) process, and dynamic wireless channel conditions. To solve the formulated problem, we analyze the time allocation for cooperative communications with EH, considering both data and energy dependency of the two hop transmissions in three cases with different network settings. Based on the analysis, we derive the closed-form solutions of optimal time and power allocation in a network with symmetric links. Then, we extend our solution to a general network with asymmetric links. By employing Lyapunov optimization, an online stochastic resource allocation algorithm is proposed to obtain the maximum network throughput. It has been shown that the proposed algorithm can achieve close-to-optimal network throughput while maintaining the stability of the system. Finally, extensive simulations validate the analysis and demonstrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In this paper, we present a mobile charging policy for perpetual operation of large-scale wireless rechargeable sensor networks (WRSNs). In these networks, dedicated mobile chargers (MCs) move throughout the network and supply energy for power-limited sensors. The MCs not only charge the sensors but also charge each other. We develop a hop-based mobile charging policy (HMCP) minimizing the number of required MCs. The HMCP considers both the sensors’ unbalanced energy consumption rate and the MCs’ limited energy capacity. The minimum number of MCs is is formulated as an integer programming problem. We first verify the existence of an optimal solution, and later design an algorithm to obtain the optimal solution. Based on HMCP, we propose HMCP+ for the case that only one MC can recharge sensors in each region. HMCP+ plans MCs’ paths to decrease mobile energy consumption by MCs. Finally, performance of the proposed polices is validated through the simulation results. [ABSTRACT FROM AUTHOR]

In body area networks, sustainable energy supply and reliable data transmission are important to prolong the service cycle and guarantee the quality of service. In this article, we build a system model to capture the stochastic processes in body area networks, including energy harvesting process, spectrum pricing process, and data sampling process. In the system model, energy harvesting technology and cognitive radio technology are adopted to provide green energy and improve transmission environment for body area networks. Based on the proposed model, we formulate an optimization problem of system utility maximization. Since this problem is a multi-objective mixed-integer problem under multiple restrictions, we decompose the problem into several subproblems by Lyapunov optimization theory. Based on this, we design an efficient online energy and channel transmission management algorithm to solve these subproblems and achieve a close-to-optimal system utility without any priori knowledge. We analyze the optimality of proposed algorithm and derive the required battery capacity and the size of data buffer. Simulation results demonstrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

• The edible quality of liquid egg after steaming, baking, frying and microwaving were compared. • Baked egg showed superior soft and elasticity taste characteristics. • Fried egg exhibited better antioxidant activity. • The texture of cooked eggs is closely related to their microstructure. The purpose of this study was to compare the edible quality of liquid egg after steaming, baking, frying and microwaving. Texture profile analysis (TPA) and color analysis were used to evaluate the sensory characteristics of cooked eggs. The fat, vitamin A and E, protein and amino acid content of cooked eggs and the antioxidant activity after in vitro digestion were determined to display the variations in nutritional value. TPA results demonstrate that baked egg exhibited a softer and more elasticity texture, with a significant lower hardness of 3234 g than fried and microwaved eggs (p < 0.05). This is also consistent with the results of cohesiveness and chewiness. Consequences from scanning electron microscope showed plentiful honeycomb structure in baked egg, which may be related to the soft and elasticity texture. However, significantly higher contents of fat, vitamins A and E, protein were determined in fried egg (p < 0.05), which may be related to its lower moisture content. The strongest free radical scavenging efficiency for the hydroxyl, the DPPH and the superoxide radical were found in the gastrointestinal digestion of fried egg, with the rate of 95.76%, 81.08%, and 91.08%, respectively. Overall, baked egg showed superior soft and elasticity taste characteristics due to its honeycomb structure, while fried egg exhibited better antioxidant activity because of its high contents in vitamins and amino acids. The above results provide potential approach for the manufacture of pre-cooked eggs and related products using liquid eggs as ingredients. [ABSTRACT FROM AUTHOR]

Background: Hypovolemia is common in colonoscopy due to fasting and bowel preparation, and propofol itself can reduce systemic vascular resistance, resulting in relative hypovolemia. Therefore, hypotension is not a rare event during propofol-based sedation for colonoscopy., Objectives: Our objective was to explore the efficacy of esketamine as a sedative adjuvant in reducing the incidence of hypotension during colonoscopy., Design: This was a prospective randomized trial. The trial was registered with the Chinese Clinical Trial Registry (ID: ChiCTR 2100047032)., Methods: We included 100 eligible patients who planned to receive a colonoscopy and randomly divided them into 4 groups with 25 patients in each group, which were propofol 2 mg/kg (Group P), propofol 1 mg/kg with esketamine 0.2 mg/kg (Group E1), propofol 1 mg/kg with esketamine 0.3 mg/kg (Group E2), and propofol 1 mg/kg with esketamine 0.4 mg/kg (Group E3). The hemodynamic and respiratory parameters were documented at various times during the procedure, including the patient's entry into the endoscopic room (T0), the induction of sedation (T1), the insertion of the colonoscope (T2), the removal of the colonoscope (T3), and the awakening of the patient (T4). The primary outcome was the incidence of hypotension. Secondary outcomes were cardiovascular side effects other than hypotension, incidence of hypoxia, cumulative changes in cardiovascular and respiratory parameters, total propofol dosage, anesthesia recovery time, and satisfactory levels of both patients and endoscopists., Results: The incidence of hypotension in Group E1 (16%), Group E2 (16%), and Group E3 (12%) was significantly lower than in Group P (60%), with p values 0.003, 0.003, and <0.001 respectively. The cumulative changes in diastolic blood pressure and mean arterial pressure in Groups E1, E2, and E3 were significantly higher than in Group P ( p  = 0.024, p  < 0.001, p  = 0.006, respectively). Cumulative changes in systolic blood pressure in Group E3 were significantly higher than those in Group P ( p  = 0.012). The respiratory-related parameters were not statistically significant., Conclusions: This study showed that the application of 0.4 mg/kg esketamine in propofol-based sedation reduced the incidence of hypotension during colonoscopy while providing satisfactory sedation., (© The Author(s), 2024.)

Significance: The identification of a role for CYP4F2-dependent metabolism in driving immune evasion in non-small cell lung cancer reveals a strategy to improve the efficacy of immunotherapy by inhibiting CYP4F2. See related article by Van Ginderachter, p. 3882., (©2022 American Association for Cancer Research.)