Non-isothermal crystallization kinetics and nucleation behavior of isotactic polypropylene composites with micro-talc

Journal of Thermal Analysis and Calorimetry - The current investigation has presented a new synthesis technique to prepare pentaethylene glycol-treated graphene nanoplatelets (PEG-GnP) and...     

The Hilbert number of a class of differential equations

The notion of Hilbert number from polynomial differential systems in the plane of degree $n$ can be extended to the differential equations of the form \[\dfrac{dr}{d\theta}=\dfrac{a(\theta)}{\displaystyle \sum_{j=0}^{n}a_{j}(\theta)r^{j}} \eqno(*)\] defined in the region of the cylinder $(\tt,r)\in \Ss^1\times \R$ where the denominator of $(*)$ does not vanish. Here $a, a_0, a_1, \ldots, a_n$ are analytic $2\pi$--periodic functions, and the Hilbert number $\HHH(n)$ is the supremum of the number of limit cycles that any differential equation $(*)$ on the cylinder of degree $n$ in the variable $r$ can have. We prove that $\HHH(n)= \infty$ for all $n\ge 1$.     

LIMIT CYCLES OF A GENERALIZED LINARD DIFFERENTIAL EQUATION VIA AVERAGING THEORY

We apply the averaging theory of first and second orders to a generalized Liénard differential equation to study the maximum number of limit cycles of the system.     

LIMIT CYCLES OF THIRD-ORDER DIFFERENTIAL EQUATION

In this paper, we investigate a third-order differential equation. Based on the averaging theory, we obtain sufficient conditions for the existence of periodic solutions to the equation.     

Sur le principe de superposition et l'équation de Riccati

In this Note we study the conditions under which a system of ordinary differential equations admits a nonlinear superposition of the solutions, and also the linearization of such systems. A particular study is established for the Riccati equation. To cite this article: S. Rezzag et al., C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

On Observer Design for a Class of Nonlinear Systems Including Unknown Time-Delay

The observer design for nonlinear systems with unknown, bounded, time-varying delays, on both input and state, is still an open problem for researchers. In this paper, a new observer design for a class of nonlinear system with unknown, bounded, time-varying delay was presented. For the proof of the observer stability, a Lyapunov–Krasovskii function was chosen. Sufficient assumptions are provided to prove the practical stability of the proposed observer. Furthermore, the exponential convergence of the observer was proved in the case of a constant time delay. Simulation results were shown to illustrate the feasibility of the proposed strategy.

     

Smart Therapeutic Strategy of pH-Responsive Gold Nanoparticles for Combating Multidrug Resistance

As several multi-target drug delivery approaches are successfully identified through preclinical screening, their clinical success is often hampered by challenges such as poor circulation stability, dissimilarities in the pharmacokinetics of different drugs, as well as targeting inefficiency. Gold nanoparticles (AuNPs) are adopted as promising nanocarriers in the co-delivery of multiple therapeutic drugs for combination therapy. The pH-responsive AuNPs are synthesized and incorporated with multiple chemotherapeutic drugs, such as doxorubicin and bleomycin. Such structures can work as drug carriers to treat cervical carcinoma by adopting a quality by design approach. The designed nanocarrier is characterized by adopting a range of physicochemical and morphological techniques. In vitro drug release and cytotoxicity of optimized nanocarriers are assessed to cervical tumor epithelial cells. The results highlight the notable advantages of colloidal AuNPs, including sustained drug release, therapeutic agent delivery with high stability, and biocompatibility for more effective treatment of cervical carcinoma. Furthermore, by improving the biodistribution and/or bioavailability profiles, it is believed that the two-in-one approach may therefore give evidence on the fate of co-loaded nanocarrier as a promising trajectory for successful clinical translation against ovarian carcinoma to achieve maximum therapeutic synergy for an individual patient.