26 research outputs found
Coffee Diterpene Derivatives as Anti-angiogenesis Agent
Among the several compounds present in coffee, the coffee-specific diterpenes have been identified as important chemoprotective agents which possess anti-carcinogenic properties.info:eu-repo/semantics/publishedVersio
Gap Dependent Bifurcation Behavior of a Nano-Beam Subjected to a Nonlinear Electrostatic Pressure
A NEW EFFICIENT APPROACH FOR MODELING AND SIMULATION OF NANO-SWITCHES UNDER THE COMBINED EFFECTS OF INTERMOLECULAR SURFACE FORCES AND ELECTROSTATIC ACTUATION
Microencapsulation of a Natural Antioxidant from Coffee - Chlorogenic Acid (3-Caffeoylquinic Acid)
Chlorogenic acids, the main polyphenolic grouppresent in coffee, which include the caffeoylquinic acids,are recognized as antioxidants with growing interest inpharmacological, cosmetic, and food applications.However, they can be easily oxidized and they are alsovery unstable when exposed to high temperatures.Therefore, they can suffer transesterification reactionsduring storage or food processing, limiting their applications. Nevertheless, this situation can be overcome orminimized by microencapsulation. The purpose of thepresent study was to prepare by a spray-drying processsodium alginate and modified chitosan microparticleswith chlorogenic acid (3-CQA), characterize them (morphological analysis), and evaluate the release profile of 3-CQA from the microparticles in in vitro studies.Furthermore, their antioxidant activity and moisture content were determined. The results address the success ofchlorogenic acid microencapsulation, resulting in stablemicroparticles with controlled release properties and goodantioxidant activity, suggesting increasing applications infood and pharmaceutical industry
A coupled bending-torsion model for electrostatically actuated torsional nano/micro-actuators with considering influence of van der Waals force
Electrostatic pull-in analysis of a nonuniform micro-resonator undergoing large elastic deflection
A 2-DOF microstructure-dependent model for the coupled torsion/bending instability of rotational nanoscanner
It has been well established that the physical performance of nanodevices might be affected by the microstructure. Herein, a two-degree-of-freedom model base on the modified couple stress theory is developed to incorporate the impact of microstructure in the torsion/bending coupled instability of rotational nanoscanner. Effect of microstructure dependency on the instability parameters is determined as a function of the microstructure parameter, bending/torsion coupling ratio, van der Waals force parameter and geometrical dimensions. It is found that the bending/torsion coupling substantially affects the stable behavior of the scanners especially those with long rotational beam elements. Impact of microstructure on instability voltage of the nanoscanner depends on coupling ratio and the conquering bending mode over torsion mode. This effect is more highlighted for higher values of coupling ratio. Depending on the geometry and material characteristics, the presented model is able to simulate both hardening behavior (due to microstructure) and softening behavior (due to torsion/bending coupling) of the nanoscanners. © 2016, Springer-Verlag Berlin Heidelberg