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Nanocomposites and nanomaterials have frequently useful advantages for drug delivery applications because of their excellent potential in cancer therapy. This study development of nanocomposites from graphene/N-phthaloylchitosan –graft- poly(methylmethacrylate-block-(poly ethylenglycol methacrylate -random-dimethylaminoethyl methacrylate), CS-g-P(MMA-b-(PEGMA-ran-DMAEMA), via reversible addition fragmentation chain transfer polymerization. The structure of the copolymer and nanocomposite were investigated by FT-IR and 1HNMR. The nanocomposites properties of GO/ CS-g-P(MMA-b-(PEGMA-ran-DMAEMA) were investigated by scanning electron microscopy (FE-SEM), dynamic light scattering, ultraviolet–visible (UV–Vis) spectroscopies, and thermogravimetry measurements. We developed a biodegradable GO nanocomposites to overcome limitations of doxorubicin (DOX)-loading. The drug loading efficiency of GO/nanocomposites for DOX was high, and 81% efficiency was obtained. Release behavior of DOX from the nanocomposites showed that the rate of DOX release is controlled by pH values.

Herein, a high performance chemiluminescence (CL) system is developed for the sensitive detection of tramadol. The CL reaction is based on the direct oxidation of rhodamine 6 G (R6 G) by potassium permanganate (KMnO4), producing an ultra-weak emission. It was found that copper nanoclusters encapsulated in copper-based two-dimensional metal-organic frameworks (CuNCs@CuMOF) create a tremendous enhancing effect on the observed emission. A probable mechanism was also suggested for CL emission based on the catalytic effects of nanomaterial and chemiluminescence resonance energy transfer (CRET) events. Besides, it was observed that tramadol caused a relatively selective increasing effect on the CL emission of R6 G-KMnO4-CuNCs@CuMOF system. In order to guarantee a selective response for tramadol, an extraction process using molecularly imprinted polymer modified Fe3O4@SiO2 nanoparticles (MIP-Fe3O4@SiO2 NPs) was applied before the CL analysis. The dispersed MIP-Fe3O4@SiO2 NPs showed high specificity for the extraction of tramadol from its samples. The combination between the high improved CL detection system and the efficient extraction process caused an ultrasensitive and selective determination method for tramadol. The best linear calibration graph was obtained in the concentration range of 0.0030–2.5 μM tramadol, with a detection limit (3Sb/m) of 0.80 nM. The illustrated CL method was tested for the quantification of tramadol in biological fluids, which led to the acceptable and reliable results.

— In this paper, our goal is to simulate abrasion resistance material. We therefore need a robust algorithm to model this phenomenon which is a kind of large frictional contact problem. In order to reach to our aim, we have proposed a new method to impose contact constraints in eXtended Finite Element Method (XFEM) framework. In this algorithm, we have modeled large sliding contact problems by using the Node To Segment (NTS) concept. Furthermore, friction between two sliding interface has been modeled based on the Coulomb friction law. In addition, the penalty method which is the most convenient way of imposing non-penetration constraints has been employed. In our algorithm, new Lagrangian shape functions have been used to solve the problems of the conventional Heaviside enrichment function. Finally, a numerical simulation has been delivered to prove the accuracy and capability of our new algorithm.