Structural characterization and properties of polyols plasticized chitosan films.

In this study, the influence of different polyols such as glycerol, xylitol and maltitol on the crystalline structure and thermal properties of chitosan films were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The concentration of polyol was fixed at 20 wt%. FTIR result showed that the addition of polyols weakened the hydrogen bonding between chitosan molecules, whereas the electrostatic interactions remained nearly unchanged.

Effect of hydration on water state, glass transition dynamics and crystalline structure in chitosan films.

The influence of water uptake on water state, glass transition dynamics and crystalline structure in chitosan films was investigated by differential scanning calorimetry (DSC), X-ray diffraction and infrared spectroscopy (FTIR) techniques. DSC result indicated that two types of water, i.e.

Effect of sorbitol content on microstructure and thermal properties of chitosan films.

In this work, the influence of sorbitol content on the microstructure and thermal properties of chitosan films was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC). It showed that the addition of sorbitol weakened the hydrogen bonding between chitosan molecules as well as the electrostatic interactions existed in chitosan films. Structural analysis revealed that a small amount of sorbitol (~10 wt%) could facilitate the crystallization of chitosan, whereas it was seriously hindered at high content of sorbitol (~50 wt%).

Effect of salt on the coil-helix transition of gelatin at early stages: Optical rotation, rheology and DSC studies.

The influence of the concentration and type of salt on the physical gelation of gelatin at early stages was explored by polarimeter, rheometer and differential scanning calorimetry (DSC). With the increase of salt concentration, both the triple helix content and the storage modulus of gelatin increased slightly and then decreased in CaCl solutions, whereas they decreased monotonically in NaCl and CrCl solutions. The addition of CaCl at low concentrations facilitated the coil-helix transition of gelatin, which could be significantly inhibited by high salt concentrations.

Molecular interactions in gelatin/chitosan composite films.

Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels.

Solid and hollow pedicle screws affect the electrical resistance: A potential source of error with stimulus-evoked electromyography.

Background: Although stimulus evoked electromyography (EMG) is commonly used to confirm the accuracy of pedicle screw placement. There are no studies to differentiate between solid screws and hollow screws to the electrical resistance of pedicle screws. We speculate that the electrical resistance of the solid and hollow pedicle screws may be different and then a potential source of error with stimulus-evoked EMG may happen.

[Development of a new noninvasive blood sugar detector].

The level of blood sugar is an improtant indicator used in the diagnosis and management of diabetes mellitus. In this respect, polarimeter and blood sugar detector were conventionally and generally used in hospitals; However, the former one is already obsolete; the latter one is invasive. In this paper, the development of a novel noninvasive blood-sugar detector is described.