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Electrochemical impedance spectroscopy (EIS) is a commonly used technique for studying internal dynamics of the proton exchange membrane (PEM) fuel cell. However, due to its linear frequency response nature and reliance on the linear target hypothesis, EIS has limitations in analyzing the nonlinear behavior of the PEM fuel cell, which is the inherently nonlinear system. To overcome this issue, this paper employs an unconventional frequency analysis technique that utilizes the high-order frequency response function (FRF) and total harmonic distortion (THD) in a broad frequency range, to conduct the nonlinear frequency response analysis (NFRA) of the PEM fuel cell. In addition to the traditional electrochemical impedance based on the first-order harmonic response, the high-order harmonic response is also included. Based on this, the appropriate excitation amplitude is determined through a comprehensive examination of the impact of varying excitation amplitudes on the impedance, second-order FRF, and THD. Then, the impacts of operating conditions, such as reactant stoichiometry, humidity, temperature, and pressure, on the FRF and THD were investigated incorporating the dynamics losses computed using EIS and equivalent circuit model. Furthermore, the nonlinear frequency response is investigated under various fault conditions, such as flooding, membrane drying, and air starvation. The results demonstrate the heightened sensitivity of the NFRA method towards detecting changes in internal processes of the PEM fuel cell, which offers a multidimensional frequency-domain perspective, facilitating the study of the advanced diagnosis, system control, material optimization, and even other electrochemical energy sources. • FRF and THD spectrum are used for nonlinear frequency response analysis of fuel cell. • Effect of various operating conditions on nonlinear frequency response is analyzed. • FRF and THD spectrum provide new perspicacity for fault feature extraction. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we consider the global gradient estimates for weak solutions of the parabolic -Laplacian type equation in a -Reifenberg flat domain. [Copyright &y& Elsevier]

Abstract: In this paper we establish the existence and uniqueness of weak solutions for the initial-boundary value problem of a generalized thin film equation. In addition, we present some interesting results on the regularity of weak solutions. [Copyright &y& Elsevier]

A moving chemical reaction boundary (MCRB) is formed by the weak alkali NH[sub 3]·H[sub 2]O and strong acid HCl with an excess of potassium chloride as background electrolyte. The experimental results are compared with the predictions in accordance with the moving chemical reaction boundary equation (MCRBE). If the MCRB is cathodic, the experimental results are in agreement with the predictions by the MCRBE. However, if the MCRB is anodic, the experimental results significantly deviate from the predictions of the MCRBE. A corrected MCRB equation is proposed for such conditions. The findings are evidently different from those in our early reports (J. Chromatogr. A, 891 (2000): 337-347; 907 (2001): 347-352; 922 (2001) 283-393). This study is of obvious benefit to capillary electrophoresis and isoelectric focusing. [ABSTRACT FROM AUTHOR]

In this paper we study the global existence of solutions to the fully parabolic chemotaxis system: u t = Δ u − χ ∇ ⋅ (u v ∇ v) + f (u) , v t = Δ v − v + u in a smooth bounded domain Ω ⊂ R n (n ≥ 3) subject to the non-flux boundary conditions, where χ > 0 and the logistic function f ∈ C 1 [ 0 , ∞) satisfies f (s) ≤ r − μ s γ with r ≥ 0 and γ , μ > 0. It is shown that the problem possesses a global and classical solution as long as γ > 2. Moreover, the global existence of the weak solution is also established provided that f (s) = r s − μ s 2 with any r , μ > 0. [ABSTRACT FROM AUTHOR]

• A new prediction model of wetting depth and wetting apparent contact angle of regular rough surface was established. • The roughness of aggregate surface, pore depth and pore resolution are important control parameters of wetting model. • Aggregate roughness, surface texture and aggregate lithology affect the wettability of epoxy resin binder on aggregate surface. • This paper provides some theoretical basis for exploring the overall wettability phenomenon and then revealing the essential laws of interfacial interactions. In order to study the effect of aggregate characteristics on the wetting of epoxy resin binder-aggregate interface, based on the Wenzel model and Cassie model, this paper established a new wetting model of the irregular rough surface. The model regularizes the rough solid surface and can calculate the wetting depth and apparent contact angle between different irregular rough solids and liquids. The texture parameters of aggregates, the surface tension of test liquids and the contact angles of different liquids-aggregates were tested by laser confocal tester and optical contact angle measuring instrument. It was found that the surface texture parameters of different aggregates were quite different. The relative error between the apparent contact angle calculated by the prediction model and the contact angle measured by the test was less than 15 %, indicating that the prediction model had excellent prediction effect. Through the analysis of the wetting model, it is found that the surface tension of the test liquid, the lithology of the solid aggregate, the surface roughness and the texture structure are the important control parameters affecting the wetting. The surface morphology of rough solid can be designed by changing the resolution k and depth H of micropores, so as to control the wettability of solid aggregate surface and epoxy resin aggregate. [ABSTRACT FROM AUTHOR]

The introduction of PARP inhibitors (PARPis) and immune checkpoint inhibitors (ICIs) has marked a significant shift in the treatment landscape for solid tumors. Emerging preclinical evidence and initial clinical trials have indicated that the synergistic application of PARPis and ICIs may enhance treatment efficacy and potentially improve long-term patient outcomes. Nonetheless, how to identify specific tumor types and molecular subgroups most likely to benefit from this combination remains an area of ongoing research. This review thoroughly examines current studies on the co-administration of PARPis and ICIs across various solid tumors. It explores the underlying mechanisms of action, evaluates clinical efficacy, identifies potential responder populations, and delineates common adverse events alongside strategic management approaches. The aim is to offer a detailed understanding of this combination therapy, potentially guiding future therapeutic strategies for solid tumors. [Display omitted] • Preclinical Study Confirms Theoretical Foundation for Combination Therapy with PARPi and ICIs. • Combination therapy improves the efficacy of recurrent ovarian cancer, Triple-negative breast cancer, endometrial cancer, and partial metastatic castration-resistant prostate cancer, while beneficial subtypes of urothelial carcinoma, lung, gastric, and pancreatic cancers are controversial. • Combining PAPRi, ICIs, and anti-angiogenic drugs, PD-1 combined with CTLA-4/LAG-3, and highly selective targeting of PARP1 inhibitors for advanced solid tumors are still investigational topics. • The adverse events of combination therapy mainly include mild-to-moderate hematologic, gastrointestinal reactions, and fatigue, while proper management can improve the patient's quality of life. [ABSTRACT FROM AUTHOR]

In this paper we mainly prove the existence and uniqueness of entropy solutions and the uniqueness of renormalized solutions to the general nonlinear elliptic equations in Musielak-Orlicz spaces. Moreover, we also obtain the equivalence of entropy solutions and renormalized solutions in the present conditions. [ABSTRACT FROM AUTHOR]

This work studies an outstanding reaction–diffusion system modeling tumor invasion, with interactions among tumor tissue, acid concentration and normal tissue. This model has very different features from the models extensively studied in the mathematics literature. The most challenge issue for mathematical analysis of the present model is the existence of classical solution, since the diffusion of tumor tissue is influenced by the density of normal cells and diffusion degeneracy arises when normal cells are at the carrying capacity. A rigorous proof of global existence and uniqueness of classical solutions is presented. Moreover, we study global dynamics of the solution, and show asymptotic stability of the four possible constant equilibria under various scenarios. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we generalize classical , , estimates of the gradient to the Orlicz space for weak solutions of quasilinear elliptic equations of p-Laplacian type. [Copyright &y& Elsevier]

In this paper, we investigate the optimal C 1 , α estimates for the elliptic p (⋅) -Laplace equation: div (a (x) | ∇ u | p (x) − 2 ∇ u) = div h (x) + f (x) in Ω with f ∈ L q (⋅) (Ω) and a , h ∈ C σ (Ω ¯). Based on a certain geometric oscillation estimate, the scaling arguments and appropriate localization technique as well as the careful analysis on the variable exponents, we exhibit how the optimal Hölder exponent of ∇ u is influenced by p (⋅) , q (⋅) and σ. This work can be regarded as a natural follow up to the paper by Araújo and Zhang (in press). [ABSTRACT FROM AUTHOR]

In this paper we use the Hardy–Littlewoodmaximal functions to obtain the following global BMO estimates f ∈ B M O (R n) ⇒ ∇ u ∈ B M O (R n) for the weak solutions of a class of quasilinear elliptic equations div a ∇ u ∇ u = div f in R n , where B (t) = ∫ 0 t τ a (τ) d τ for t ≥ 0. Meanwhile, we use the iteration-covering procedure to prove that B f ∈ L q (R n) ⇒ B ∇ u ∈ L q (R n) for any q > 1 for the weak solutions of div a ∇ u ∇ u = div a f f in R n. Moreover, we remark that a (t) = t p − 2 (p -Laplace equation) and a (t) = t p − 2 log (1 + t) satisfy the given conditions in this work. [ABSTRACT FROM AUTHOR]