Synergetic catalytic effect of rGO,Pd, Fe3O4 and PPy as a magnetically separable and recyclable nanocomposite for coupling reactions in green media

In this paper, rGO/Pd–Fe₃O₄@PPy as an efficient stable nanocomposite was synthesized. To understand the synergetic effects of rGO, Pd, Fe₃O₄ and PolyPyrrole, the performance of rGO/Pd–Fe₃O₄@PPy as a heterogeneous recyclable nanocatalyst in the green synthesis of C‐C and C‐O coupling products, as well as different conditions are studied. Synthesized rGO/Pd–Fe₃O₄@PPy was characterized by FT‐IR, XRD, FE‐SEM, EDS, TGA and AFM analysis. Best results are obtained under sonication in H₂O for C‐C coupling and by ball‐milling for C‐O coupling. The benefits of this method include: green solvents and conditions, absence of external base, low reaction times with high yield and easy work‐up method.     

99mTc-radiolabeled imidazo[2,1-b]benzothiazole derivatives as potential radiotracers for glioblastoma

This study presents [^99mTc]BPTG-1 and [^99mTc]BPTG-2 for glioblastoma imaging. In vitro cellular uptakes of these radiotracers were examined in SKOV-3, MCF-7, U87-MG, HT-29, and A549 cell lines. U87-MG cell line displayed the highest radiotracers uptakes. Biodistribution study in U87-MG tumor bearing mice revealed higher uptake of radiotracers in tumor than muscle and brain. Liver, intestine, and kidneys displayed the highest radioactivity uptakes. The main route of radiotracers elimination was hepatobiliary. Due to the brain uptake of these radiotracers, they are promising radiotracers for future studies in the diagnosis of glioblastoma.

     

Gain and noise figure improvements in a shorter wavelength region of EDFA using a macrobending approach

Gain and noise figure improvements are demonstrated in a shorter wavelength region of a double-pass EDFA using a macrobending approach. The EDF is wound in a small radius to suppress the amplified spontaneous emission at the longer wavelength in order to achieve a high amplification in the shorter wavelength. Gain enhancements of about 12–14 dB are obtained with macrobending at the wavelength region between 1480 and 1530 nm. The macrobending also reduces the noise figure of the EDFA at wavelengths shorter than 1525 nm with a maximum improvement of 25 dB.     

Estimation of the transient interfacial heat flux between substrate/melt at the initiation of magnesium solidification on aluminum substrates using the lumped capacitance method

Interfacial heat flux (IHF) between solid pure aluminum/magnesium melt and solid 413 aluminum alloy/magnesium melt couples was evaluated using lumped capacitance method, and the interface microstructures were assessed by scanning electronic microscope. The variation of maximum IHF with surface roughness for these two couples also was evaluated. The results showed that, for both solid aluminum/magnesium melt couples, with increasing the surface roughness, the maximum IHF increases at first and then starts to decrease after reaching a maximum value. In addition the measured maximum IHF for solid 413 aluminum alloy/magnesium melt couples was found to be higher than those measured for solid pure aluminum/magnesium melt couples. That seems to be because of the better wettability of 413 aluminum alloy than pure aluminum, by magnesium melt.     

In situ forming PLGA implant for 90 days controlled release of leuprolide acetate for treatment of prostate cancer

In prostate cancer, hormone therapy via leuprolide acetate drug (LUP) is used to lower the level of testosterone down to castration level to effectively control the development of prostate cancer. The objective of this study was to evaluate the effective parameters in degradation and controlled release of an injectable in situ formed polymeric implant, loaded with leuprolide acetate, in order to achieve an optimum formulation for sustained drug release for 90 days with minimum burst release. The main problem associating with such implants is their high burst release. Designing an injectable implant with sustained and minimum burst release has thus become an attractive challenge in drug delivery field. Effects of type of poly(lactic‐co‐glycolic acid) 75:25 copolymers (RG752, RG756) and addition of nano‐hydroxyapatite (HA) particles on degradation rates of the implants and release profiles were examined in vitro and in vivo in a rabbit animal model. Results showed that implants containing polymers with higher molecular weights had significantly lower weight loss and molecular weight reduction. Adding nanoparticles of hydroxyapatite into poly(lactic‐co‐glycolic acid) implants caused further reduction in degradation rates, leading to a more sustained drug release in vivo, with reduced burst release. Different conventional kinetic models were applied to drug release and degradation data. The degradation data fit well to the first‐order degradation model. Higuchi model was the best kinetic release model fitted to the experimental in vitro release data. This study led to an optimum formulation (RG756:RG752 3:1 + 5% HA) with sustained leuprolide release and testosterone suppression over a 90‐day period with significant decrease of burst release phase (50%, p < 0.001) compared with the conventional Eligard formulation. The histopathology test showed that the formulated implant had no effects of toxicity or tissue necrosis in organs of the animal model. Copyright © 2017 John Wiley & Sons, Ltd.