13 research outputs found
Effect of Physical Exercise on Bone Density and Remodeling in Egyptian Type 1 Diabetic Osteopenic Adolescents
<p>Abstract</p> <p>Background</p> <p>The study was planned to assess effect of physical exercise on bone remodeling in type I diabetics with osteopenia.</p> <p>Methods</p> <p>Twenty-four type I diabetes mellitus (DM1) with osteopenia (10 females and 14 males) were compared to thirty-eight age- and sex-matched healthy control individuals (20 females and 18 males) for biochemical and radiologic parameters of bone mass. Laboratory investigations included serum and urinary calcium, inorganic phosphorus, alkaline phosphatase, and serum "procollagen type 1 N-terminal propeptide (P1NP). Bone densitometry was assessed at neck femur using Dual Energy X-ray Absorptiometry (DEXA). Serum P1NP and DEXA were reevaluated after a planned exercise program.</p> <p>Results</p> <p>Patients and controls were comparable with respect to serum as well as urinary biochemical parameters of bone mass namely; calcium, phosphorus and total serum alkaline phosphatase. Osteopenic DM1 patients displayed lower mean serum P1NP than control group (20.11 ± 6.72 ugdL versus 64.96 ± 34.89 ugdL; p < 0.05). A significant correlation was observed between BMD and degree of glycemic control reflected by serum glycated hemoglobin (r = -0.44, p, 0.030). Bone densitometry correlated with serum P1NP (r = -0.508, p, 0.011). After a planned regular exercise for 3 months, serum P1NP and BMD levels increased with percentage change of 40.88 ± 31.73 and 3.36 ± 2.94, respectively. Five patients resumed normal densitometry and they were all males.</p> <p>Conclusion</p> <p>Diabetic osteopenic patients displayed lower serum levels of procollagen type 1 N-terminal propeptide which reflects poor bone formation. A 3-months planned exercise program was associated with improvement of bone densitometry and significant increment of serum P1NP.</p
Structural, optical, morphological and thermal properties of PEO/PVP blend containing different concentrations of biosynthesized Au nanoparticles
Casting technique was used for preparation of polyethylene oxide (PEO)/polyvinyl pyrrolidone (PVP) (70/30 wt.%) films filled with different concentrations of gold nanoparticles (Au NPs). X-ray diffraction (XRD) pattern proved the semi-crystalline nature of the pristine and filled polymer blend. Fourier transform infrared (FT-IR) and Ultraviolet/Visible (UV/Vis.) analyses were used to retrace the structural and optical changes with increasing Au content. UV/Vis. analysis spectroscopy was utilized to calculate the optical properties such as optical energy gap Eg, refractive index n and Urbach energy Eu for blend/Au nanocomposite films. Scanning electron micrograph (SEM) suggested the dependence of morphological structure on filling level and the surface morphology changed from rough to smooth. Transmission electron microscope (TEM) micrographs showed that the size of Au NPs was increased with continuous filling in PEO/PVP. Thermogravimetric analysis (TGA) was performed to investigate the thermal stability for nanocomposite films. Keywords: PEO/PVP, Au NPs, FT-IR, Optical properties, TG
Structural investigation and enhancement of optical, electrical and thermal properties of poly (vinyl chloride-co-vinyl acetate-co-2-hydroxypropyl acrylate)/graphene oxide nanocomposites
Different concentrations of graphene oxide (GO) were successfully embedded into poly (vinyl chloride-co-vinyl acetate-co-2-hydroxypropyl acrylate) (PVVH) copolymer. The composites obtained were characterized using XRD, FT-IR, SEM and UV/Vis techniques, in addition to investigating their electrical properties. XRD results showed the predominance of the amorphous phase inside the prepared samples. The main characteristic peaks of the used materials were observed in FT-IR spectra with changes in their intensities and/or their positions, confirming the successful complexation and strong interaction between GO and PVVH. A bathochromic shift in the main absorption sharp edge was detected in UV/Vis spectra. Additionally, the two peaks at 214 and 280 nm were ascribed to n→π* and π→π* transitions, respectively. Both optical energy gap and refractive index were calculated in terms of UV/Vis absorption spectra using Mott–Davis model and Dimitrov–Sakka equation. The thermal behavior of the current samples was carefully investigated by employing TGA. Moreover, the activation energy was studied using Coats-Redfern and Broido models. The homogeneous dispersion of GO has contributed to the significant increase in the electrical conductivity as well as improving thermal stability of the PVVH-based nanocomposites. The experimental results obtained for the current system promote these nanocomposites for use in optoelectronic applications. Keywords: PVVH, Graphene oxide, Nanocomposite, Optical energy gap, Thermal stability, Electrical conductivit