Fractional Order Nonlinear Bone Remodeling Dynamics Using the Supervised Neural Network

This study aims to solve the nonlinear fractional-order mathematical model (FOMM) by using the normal and dysregulated bone remodeling of the myeloma bone disease (MBD). For the more precise performance of the model, fractional-order derivatives have been used to solve the disease model numerically. The FOMM is preliminarily designed to focus on the critical interactions between bone resorption or osteoclasts (OC) and bone formation or osteoblasts (OB). The connections of OC and OB are represented by a nonlinear differential system based on the cellular components, which depict stable fluctuation in the usual bone case and unstable fluctuation through the MBD. Untreated myeloma causes by increasing the OC and reducing the osteoblasts, resulting in net bone waste the tumor growth. The solutions of the FOMM will be provided by using the stochastic framework based on the Levenberg-Marquardt backpropagation (LVMBP) neural networks (NN), i.e., LVMBPNN. The mathematical performances of three variations of the fractional-order derivative based on the nonlinear disease model using the LVMPNN. The static structural performances are 82% for investigation and 9% for both learning and certification. The performances of the LVMBPNN are authenticated by using the results of the Adams-Bashforth-Moulton mechanism. To accomplish the capability, steadiness, accuracy, and ability of the LVMBPNN, the performances of the error histograms (EHs), mean square error (MSE), recurrence, and state transitions (STs) will be provided.     

High-performance liquid chromatographic determination of arbutin in skin-whitening creams and medicinal plant extracts

A high-performance liquid chromatographic method was developed for quantitative analysis of arbutin. The arbutin was separated on an ODS Hypersil^® C18 column with a mobile phase of water: methanol: 0.1 M hydrochloric acid (89:10:1, v/v/v). The level of arbutin was measured by means of UV detection at 222 nm. The optimum conditions for arbutin quantitative analysis were investigated. The calibration curve was found to be linear up to 1000 μg/ml^-1 of arbutin concentration, and the working calibration curve for arbutin determination over the range 0.5–30.0 μg/ml^-1 of arbutin ( r ² = 0.9999) was established. The relative standard deviations for intraday and interday were found to be 0.98% and 1.15%, respectively. A detection limit (3σ) and quantitation limit (10σ) of 0.02 μg/ml^-1 and 0.2 μg/ml^-1, respectively, and a mean percentage recovery of the spiked arbutin of 99.88 ± 1.12% were obtained. The proposed method has been applied to the determination of arbutin in commercial skin-whitening creams (Arbuwhite^® cream, Super Whitening^® cream, and Shiseido^® cream) with average contents of 7.60, 5.30, and 57.90 mg/g^-1, respectively. It was also applied to the determination of arbutin in medicinal plant extracts from Betula alnoides Buch. Ham., Clerodendrum petasites S. Moore, Curculigo latifolia Dryand. Var. latifolia, and Hesperethusa crenulata (Roxb.) Roem, levels of which were found to be 3.50, 1.50, 1.10, and 0.12 μg/g^-1, respectively (no article reported in the literature about arbutin analysis). The proposed HPLC method is rapid, simple, and selective for routine analysis.     

Wide-band amplitude control of the second-order oscillator circuit

In this paper, a new analysis technique of an ordinary second-order oscillator which is based on multi-time concept is proposed. This mathematical analysis results in a new closed-form solution of a system complete response. It is found that amplitude of the natural response is not constant but varied with the forced response of the system. For a constant forcing function proposed, the new analysis is identical to the conventional analysis. In the case of time-varying forcing function, however, it is different from the conventional approach. Based on such analysis, it implies that the amplitude of a second-order oscillator can easily be controlled by forced response of the system. Hence, the obtained result based on the proposed analysis technique provides a proper mathematical solution for the system, especially in a time-varying forcing function. Moreover, the mathematical analysis for the wide-band characteristic of a second-order oscillator is also described. The experimental results demonstrate the responses of the oscillator which agree well between the theoretical and simulation results.     

Biological characteristic effects of human dental pulp stem cells on poly-ε-caprolactone-biphasic calcium phosphate fabricated scaffolds using modified melt stretching and multilayer deposition

Craniofacial bone defects such as alveolar cleft affect the esthetics and functions that need bone reconstruction. The advanced techniques of biomaterials combined with stem cells have been a challenging role for maxillofacial surgeons and scientists. PCL-coated biphasic calcium phosphate (PCL-BCP) scaffolds were created with the modified melt stretching and multilayer deposition (mMSMD) technique and merged with human dental pulp stem cells (hDPSCs) to fulfill the component of tissue engineering for bone substitution. In the present study, the objective was to test the biocompatibility and biofunctionalities that included cell proliferation, cell viability, alkaline phosphatase activity, osteocalcin, alizarin red staining for mineralization, and histological analysis. The results showed that mMSMD PCL-BCP scaffolds were suitable for hDPSCs viability since the cells attached and spread onto the scaffold. Furthermore, the constructs of induced hDPSCs and scaffolds performed ALP activity and produced osteocalcin and mineralized nodules. The results indicated that mMSMD PCL-BCP scaffolds with hDPSCs showed promise in bone regeneration for treatment of osseous defects.     

Preliminary Study of Conformation and Drug Release Mechanism of Doxorubicin-Conjugated Glycol Chitosan, via cis-Aconityl Linkage, by Molecular Modeling

An investigation of the structure and drug release mechanism of a drug delivery system is proposed on the basis of semi-empirical and ab initio computations in vacuum stage. Cis-aconityl linkage is used to improve the interaction between an anti-cancer agent, doxorubicin, and a glycol chitosan biopolymer. It has been found that the doxorubicin-conjugated glycol chitosan carrier has more stability. The stability is increased when the lengths of the polyethylene glycol (PEG) chains in the glycol chitosan biopolymer are increased. Cis-aconityl can release doxorubicin under appropriate environmental conditions. Relative energies of this mechanism in an acid condition, as determined by B3LYP/6-31G//PM3, are 122.41, 119.27, 160.18 and 222.22 kcal/mol, and by the B3LYP/6-31G//HF/6-31G method are 54.23, 109.28, 219.98 and 980.49 kcal/mol, with mono-, di-, tri-, and quanta-ethylene glycol, respectively. In a normal condition, the relative energies are above 300 kcal/mol for all reactions. Therefore, cis-aconityl will release doxorubicin in an acid solution but not in a normal condition. The glycol chitosan polymer can be degraded in an acid solution as well. Long PEG chains influence the release mechanism of doxorubicin. The proposed length of the PEG chain is di-ethylene glycol. These simulation results agree well with various reported experimental data.     

Simulation of mass exchange networks using modified genetic algorithms

The optimum water usage network leads to both a minimum of freshwater consumption and a minimum of generated wastewater. This work is to develop a mass-exchange networks (MENs) module for a minimum freshwater usage target. This module works as an interface to retrieve supplemental data of chemical processes from a process simulator and to communicate this to the genetic algorithm optimizer. A reuse system and a regeneration/recyclingsystem with a single contaminant are considered as approaches for freshwater minimization. In the formulated model, as mixed integer nonlinear programming (MINLP), all of the variables are divided into independent and dependent variables. The values of independent variables come from randomization, whereas the values of dependent variables come from simultaneous solutions of a set of equality constraints after assigning the values of independent variables. This method is applied to the steps of initialization, crossover and mutation. The MENs module is validated with a tricresylphosphate process consisting of five unit operations. Water is used to remove a fixed content of cresol. From the result, the module gives a reliable solution for freshwater minimization, which can satisfy mass balance and constraints. The results show that reuse and regeneration/recycling strategies can reduce freshwater consumption, including wastewater generated. Reuse cannot decrease the mass load of the contaminant, while regeneration/recycling can. In addition, regeneration requires less freshwater than the reuse process.     

Xylitol production by liquid emulsion membrane encapsulated yeast cells

BACKGROUND: Liquid emulsion membrane (LEM)‐encapsulated live cells can be used to produce various products. This work reports on LEM‐encapsulated cells for producing xylitol and models the production process. RESULTS: Encapsulated cells of Candida mogii ATCC 18364 were used to produce xylitol from xylose. Soybean oil LEM consisting of 5% (w/v) lanolin and microwaxes was found most suitable for this process. The LEM‐encapsulated cells were immobilized in a tubular biocatalytic loop. Xylitol was produced under oxygen‐limited and aerobic conditions. Xylitol productivity and yield were 0.005 g L^?1 h^?1 and 0.52 g g^?1, respectively, for oxygen‐limited operation. Under aerobic conditions, xylitol productivity increased greatly to 0.022 g L^?1 h^?1, but yield on xylose declined to 0.49 g g^?1. A mathematical model successfully described substrate consumption and product formation in the LEM‐immobilized cell system. CONCLUSION: Potentially, immobilized cell LEM systems are useful for certain fermentations and they can be successfully modeled, as shown by the example of xylitol from xylose process. Copyright © 2009 Society of Chemical Industry