Self-assembled poly(ethylene glycol) methyl ether-grafted gelatin nanogels for efficient delivery of curcumin in cancer treatment

Curcumin (CUR) is a natural active ingredient that attracted much attention for its chemotherapeutic activity against tumors without causing toxicity in healthy cells. However, it has certain limitations for being used in chemotherapy such as low aqueous solubility and hydrolytic instability in the physiological environment. In this study, self-assembled poly(ethylene glycol) methyl ether-grafted gelatin (Gel-mPEG) nanogels were fabricated as delivery systems to improve the applicability of CUR in cancer treatment. CUR-loaded Gel-mPEG nanogels exhibited desired size range, relatively colloidal stability, and provided enhanced CUR stability in aqueous solutions. Especially, they showed significant high CUR loading capacity and better anticancer activity than free CUR as compared to previously reported CUR-loaded nanogels according to the best of our knowledge. Moreover, the in vitro release of CUR from the nanogels was controlled and prolonged up to 96 h. These results demonstrated that Gel-mPEG nanogels are the promising modality for the efficient delivery of CUR in cancer treatment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47544.     

Phase formation and mechanical properties of Cu-Zr-Ti bulk metallic glass composites

The effect of the type of the crystalline phase and its volume fraction on the mechanical property of Cu₅₀Zr_50-xTi_x alloys (x = 0-10) bulk metallic glass composites has been investigated in this study. Up to 6 at% of Ti, B19’ phase particles distributed in the glassy matrix, while at 8 and 10% of Ti, B2 phase particles are retained in the glass matrix due to suppression of the eutectoid transformation of B2 phase and by avoidance of martensitic transformation of B2 into B19’. The volume fraction of crystalline phase is strongly dependent on the cooling rate. The larger volume fraction of the crystalline phases results in the lower yield stress, the higher plastic strain, and the more pronounced work hardening behavior. At the crystalline volume fraction below ~30%, the variation of the yield strength can be described by the rule of mixture model (ROM), while at the crystalline volume fraction higher than ~50% by the load-bearing model (LBM). At the crystal fractions between 30 and 50%, there is a yield strength drop and a transition from the ROM to the LBM. This transition is due to the formation of the crystalline structural framework at higher crystal fraction.     

Wrench-feasible workspace analysis considering aerodynamics of aerial robotic camera under high speed

Microsystem Technologies - Recently, there have been demand for aerial robotic cameras that offer a large working space, long broadcasting times, and excellent dynamic stability to broadcast live...     

Analysis of heat-transfer performance of cross-flow fin-tube heat exchangers under dry and wet conditions

A three-dimensional analysis procedure for the detailed phenomenon in a fin-tube heat exchanger has been developed and applied to predict the heat/mass transfer characteristics of the wave-fin heat exchangers. The continuity, Navier–Stokes and energy equations together with the species equation for the air–vapor mixture are solved in a coupled manner, so that the inter-dependence between the temperature and the humidity can be properly taken into account, by using the SIMPLE-type finite volume method. Having validated the procedure, calculations have been carried out for various frontal-velocity and inlet-humidity conditions. It has been shown that the flow characteristics, such as the temperature and humidity fields, along with the local heat flux and the condensation rate, can be successfully captured. The numerical results reveal that the existing correlations considerably underestimate the fin efficiency especially for multi-row heat exchangers. For dehumidifying cases, the sensible heat-transfer rate seems insensitive to the inlet-humidity change. The rate changes mostly in the narrow band of partially wet regime between 25% and 40% of inlet relative humidity. The range of the frontal velocity that gives the best performance for various numbers of rows is also estimated. The analogy between the heat and mass transfer on the fin surface is also examined.     

On data dependence of stability domains,exponential stability and stability radii for implicit linear dynamic equations

We shall deal with some problems concerning the stability domains, the spectrum of matrix pairs, the exponential stability and its robustness measure for linear implicit dynamic equations of arbitrary index. First, some characterizations of the stability domains corresponding to a convergent sequence of time scales are derived. Then, we investigate how the spectrum of matrix pairs, the exponential stability and the stability radii for implicit dynamic equations depend on the equation data when the structured perturbations act on both the coefficient of derivative and the right-hand side.     

Measurement and correlation of the isobaric vapor-liquid equilibrium for mixtures of alcohol+ketone systems at atmospheric pressure

Vapor-liquid equilibrium (VLE) for binary mixtures composed of ethanol+methyl isobutyl ketone, 1-butanol+ methyl ethyl ketone, and 1-butanol+methyl propyl ketone systems was measured using a circulation type equilibrium apparatus at atmospheric pressure. The measured data and literature data for alcohol and ketone systems have been correlated by the UNIversal Quasi-Chemical (UNIQUAC) model with two binary interaction parameters and the non-random lattice fluid equation of state with hydrogen bonding equation of state (NLF-HB EoS) using a single binary interaction parameter. For the NLF-HB EoS calculations, the numbers of proton acceptor for ketones were adjusted between 0 and 1. The calculation results with the NLF-HB EoS are better than those with the UNIQUAC model.     

Investigation of organic n-type field-effect transistor performance on the polymeric gate dielectrics

We report a copper hexadecafluorophthalocyanine (F₁₆CuPc) based n-type organic field-effect transistor (OFET) with polymeric gate dielectrics with different physical/electrical properties. The gate dielectrics are four types of cross-linked poly(4-vinylphenol) and newly prepared poly(4-phenoxy methyl styrene) and those are characterized based on surface tension, leakage current and capacitance. The performance of F₁₆CuPc OFETs with those gate dielectrics was compared. We found that the composition of the gate dielectrics and the interfacial interaction of F₁₆CuPc with the gate dielectric play a decisive role in the performance of OFETs. The effect of physical/electrical properties, composition and processing condition of the gate dielectrics on the device performance was investigated.     

Computational Nonlinear Thermomechanical Model of Large Light Partition Walls Based on Experimental Analysis and Probabilistic Models

Abstract: This article is devoted to the construction of a computational nonlinear thermomechanical model of large light partition walls made up of cardboard‐plasterboard‐cardboard (CPC) plates screwed to a metallic frame, and is submitted to mechanical and thermal loadings induced by fire. The computational model, based on experimental analysis and a probabilistic modeling, is developed for the prediction of a large light partition wall for (1) its linear thermal behavior, (2) its nonlinear mechanical behavior, and (3) its nonlinear thermomechanical behavior.