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This paper focuses on optimizing an unknown cost function through extremum seeking (ES) control in the presence of a slow nonlinear dynamic sensor responsible for measuring the cost. In contrast to traditional perturbation-based ES control, which often suffers from sluggish convergence, the proposed method eliminates the time-scale separation between sensor dynamics and ES control by using the relative degree of the nonlinear sensor system. To improve the convergence rate, the authors incorporate high-frequency dither signals and a differentiator. To enhance the robustness with the existence of rapid disturbances, an off-the-shelf linear high-gain differentiator is applied. The first result demonstrates that, for any desired convergence rate, with properly tuned parameters for the proposed ES algorithm, the input of the cost function can converge to an arbitrarily small neighborhood of the optimal solution, starting from any initial condition within any given compact set. Furthermore, the second result shows the robustness of the proposed ES control in the presence of sufficiently fast, zero-mean periodic disturbances. Simulation results substantiate these theoretical findings.

The majority of literature for averaging methods deal with a class of nonlinear time-varying (NLTV) dynamics and their time-invariant averaged systems with locally Lipschitz continuous (LLC) condition. In this work, a class of uniformly continuous NLTV systems and their uniformly continuous averaged systems are considered. The first result shows the closeness of solutions between the original NLTV system and its averaged system with a sufficiently small time-scale separation parameter ε on a subset of a time interval, in which both systems have well-defined solutions. If the averaged system is finite-time stable (FTS), the second result shows that the original NLTV system will uniformly converge to an arbitrarily small neighborhood of the origin on a finite-time interval with sufficiently small ε. Simulation results support the theoretical finding.

Superhydrophilic membranes with underwater superoleophobicity for oil-water separation have been attracted widely attention. Nevertheless, oil contamination of such membranes represents a pressing challenge in this field. Superhydrophilic/underwater superoleophobic membranes with surface zwitterionic moieties are proved to show excellent antifouling properties; however, such zwitterionic surface modifiers adopted previously usually face the problem of cumbersome synthesis relying on expensive reagents and complicated procedures, accompanied with poor acid/alkali resistance due to the unstable linkers, restricting their practical applications. Herein, we describe an alternative strategy for fabricating antifouling superhydrophilic/underwater superoleophobic membranes from a natural amino acid. Sand particle-based sintered glass membranes were firstly coated with silicone nanofilaments using vinyltrichlorosilane as a precursor through chemical vapor deposition; and then the surfaces of silicone nanofilaments were further functionalized with cysteine via thiol-ene click chemistry. The resulting membranes exhibited high separation flux and efficiency for gravity-driven separation of various oil-water mixtures and surfactant-stabilized oil-in-water emulsions. Moreover, such membranes displayed excellent antifouling properties and were reusable for the separation of oil-water mixtures and surfactant-stabilized oil-in-water emulsions. With the advantages of facile fabrication, low-cost, fouling resistance and high separation performance, we believe that cysteine-based glass membranes without any hydrolytic bonds will arouse tremendous attentions for oil-water separation.

The interannual variation of the North Equatorial Current (NEC) across the North Pacific Ocean and the modulation of the Pacific Decadal Oscillation (PDO) are investigated based on both observations and reduced gravity model experiments. Results reveal that the interannual variation of the NEC is highly related to El Niño‐Southern Oscillation (ENSO) with unsynchronized variations both in zonal and meridional structure. The tropical and subtropical gyre branches of the NEC (NEC‐S and NEC‐N) behave antiphase variation during El Niño events with the transport of the former being enhanced and the latter being weakened across the Pacific. The NEC axis in the western/eastern Pacific shifts northward/southward during El Niño events, consistent with the meridional shift of the zero‐line of wind stress curl. Model experiments indicate that Rossby waves mainly modulate the NEC near the western boundary and the NEC‐N, while Ekman pumping modulates NEC‐S in the western basin. Meanwhile, the relationship between the interannual variation of the NEC and ENSO events is significantly modulated by different PDO phases. The PDO cold phase favors a much closer connection between the NEC and the Niño 3.4 index. The dynamics lie in that PDO‐related wind stress curl and sea level anomalies are consistent with that of El Niño, favoring the enhanced correlation between NEC and El Niño. The reverse is true for the warm phase. These results will contribute to a better understanding of the behavior of the tropical Pacific Ocean circulation and its role in climate change. Serving as the boundary of tropical and subtropical gyres, the North Equatorial Current plays an important role in the exchanging of mass, heat, and salt between the mid‐ and low‐latitude oceans. It is a very broad current and behaves quite differently in both zonal and meridional directions across the Pacific due to the phase lag of propagated Rossby waves. This study reveals that the interannual variation of the North Equatorial Current is highly related to El Niño‐Southern Oscillation (ENSO) with unsynchronized variations in zonal and meridional structure. The tropical and subtropical gyre branches of the North Equatorial Current behave antiphase variation during El Niños with the transport of the former is enhanced and the latter weakened across the Pacific. Rossby waves excited west of the dateline modulate the North Equatorial Current near the western boundary, while those excited in the eastern Pacific modulate the subtropical branches. Local Ekman pumping plays a dominant role in tropical branches in the western Pacific. Further analysis indicates that the ENSO‐related air‐sea state in the tropical Pacific Ocean is modulated by Pacific Decadal Oscillation phases. The cold phase favors a much closer connection between the North Equatorial Current and ENSO events. Interannual variation of the North Equatorial Current (NEC) is highly related to El Niño‐Southern Oscillation (ENSO) with unsynchronized variations both in zonal and meridional structureRossby waves mainly modulate the NEC near the western boundary and subtropical gyre branch, while Ekman pumping modulates the tropical gyre branchThe relationship between the NEC and ENSO is nonstationary and significantly modulated by different phases of the Pacific Decadal Oscillation Interannual variation of the North Equatorial Current (NEC) is highly related to El Niño‐Southern Oscillation (ENSO) with unsynchronized variations both in zonal and meridional structure Rossby waves mainly modulate the NEC near the western boundary and subtropical gyre branch, while Ekman pumping modulates the tropical gyre branch The relationship between the NEC and ENSO is nonstationary and significantly modulated by different phases of the Pacific Decadal Oscillation

Introduction: Neoadjuvant chemoradiotherapy (nCRT) followed by operation has become the standard treatment for locally advanced rectal cancer (LARC). However, considering the possible toxicity and complications of radiochemotherapy, nCRT is seldom used for the elderly. The purpose of this study was to assess the safety and long-term effect of nCRT combined with TME in elderly patients with LARC.Method: Four-hundred-fourteen LARC patients were divided into 2 groups: 108 patients were in the elderly group (≥ 65 years old) and 306 patients were in the non-elderly group (<65 years old). The side effects, toxicity, complications, disease-free survival (DFS), and overall survival (OS) of all of the patients were assessed.Results: The data comprised 103 patients in the elderly group and 292 patients in the non-elderly group who completed nCRT sessions following operation. The treatment-completion rates of the elderly and non-elderly groups were 95.37% and 95.42%, respectively. Twenty-two patients developed radiotherapy complications (grade III) in the elderly group and 37 such cases developed in the non-elderly group. Diarrhea, skinulcer, and perianal pain were ranked as the top 3 most common complications. The incidence of infection, anastomotic leakage, and intestinal obstruction was 0.97% in the elderly group. The 5-year DFS and 5-year OS rate were 70.7% and 80.8% in the elderly group, 67.3% and 81.6% in the non-elderly group respectively.Conclusions: nCRT are safe and effective for elderly patients, and it does not increase the risk of postoperative complications for the elderly. Hence, nCRT should not be withheld based on age alone.