Modification of Activated Carbon and Its Application in Selective Hydrogenation of Naphthalene.

The MoS2/ACx catalyst for hydrogenation of naphthalene to tetralin was prepared with untreated and modified activated carbon (ACx) as support and characterized by X-ray powder diffraction, Brunauer-Emmett-Teller, scanning electron microscopy, temperature-programmed desorption of ammonia, X-ray photoelectron spectroscopy, and scaning transmission electron microscopy. The results show that the modification of activated carbon by HNO3 changes the physical and chemical properties of activated carbon (AC), which mainly increases the micropore surface area of AC from 1091 to 1209 m2/g, increases the micropore volume of AC from 0.444 to 0.487 cm3/g, increases the oxygen-containing functional groups of AC from 5.46 to 7.52, and increases the acidity of catalysts from 365.7 to 559.2 mmol/g. The modified catalyst showed good catalytic performance, and the appropriate HNO3 concentration is very important for the modified of activated carbon. Among all the catalysts used in this study, the MoS2/AC3 catalyst could achieve the highest yield of tetralin. It can be attributed to the moderate acidity of the catalyst, reducing the cracking of hydrogenation products. Also, the proper hydrogenation activity of MoS2 and the appropriate increase of oxygen-containing functional groups on the surface of modified activated carbon are beneficial to the dispersion of active components on the support, increasing the yield of tetralin. The catalytic performance of MoS2/AC3 is better than that of MoS2/Al2O3 catalyst, and the two catalysts show different hydrogenation paths of naphthalene.

Effects of microwave vacuum drying on the moisture migration, microstructure, and rehydration of sea cucumber.

Effectsof microwave vacuum drying (MVD) on moisture migration, microstructure, and rehydration of sea cucumber were investigated in this paper. Vacuum condition avoided the exposure of sea cucumber to high temperature. Low-field nuclear magnetic resonance relaxation results revealed that the peaks of three water components in sea cucumber shifted to short relaxation time during MVD process, and the peak area of major water component-immobilized water-decreased significantly due to water evaporation. Magnetic resonance imaging found that the water in the internal layer of sea cucumber body wall was first removed due to the internal heating of microwave, and then the water in the outer layer. Higher microwave power could promote the moisture transfer motion during drying process, and shorten the drying time. Porous microstructure was observed by Cryo scanning electronic microscope images in sea cucumber dried with microwave power of 200 and 250 W, which might be responsible for high values of rehydration ratio and water holding capacity. High microwave power caused the increase of amino acids content, but had no significant effect on the change of saponins content. In addition, excellent prediction models of moisture ratio have been developed by partial least squares regression analysis based on transverse relaxation data, which proved the feasibility of low-field nuclear magnetic resonance to monitor moisture changes of sea cucumber during MVD process. PRACTICAL APPLICATION: Effects of microwave vacuum drying (MVD) on moisture migration, microstructure, and rehydration of sea cucumber were investigated. Understanding the impacts of MVD drying on water status, texture, and nutritional characteristics of sea cucumber is important to improve the processing quality of dried sea cucumber.

Preparation and In Vitro Evaluation of a Nano Ultrasound Contrast Agent Targeting Pancreatic Cancer.

To prepare a nano-sized ultrasound contrast agent that specifically targets pancreatic cancer cells and to evaluate its targeting effect In Vitro. PLGA-PEG-NHS was synthesized using PLGA, NHS, and PEG and detected using 1H-NMR. PLGA-PEG-NHS and PFOB were used to prepare PLGA nano contrast agent coated with PFOB by emulsification and volatilization, and then a hedgehog antibody was conjugated. The morphology of the nano contrast agent was observed using a transmission electron microscope, and its particle size and potential were measured using the dynamic light scattering method. The entrapment and drug loading efficiency of the nano contrast agent was measured using gas chromatography-mass spectrometry. The In Vitro release characteristics of the nano contrast agent was measured using the dialysis method. Human pancreatic cancer cell lines SW1990 and CFPAC1 were cultured in medium containing the nano contrast agent. The targeting ability of the nano contrast agent was qualitatively and quantitatively verified using fluorescence microscopy and flow cytometry. The average particle size of the targeted ultrasound contrast agent was 198.9 nm, zeta potential was -31.8 mv, entrapment rate was 63.7±3.9%, drug loading efficiency was 14.3±0.9%, and drug release was 85.3% in 48 h. In Vitro cell experiments showed that the targeted ultrasound contrast agent strongly bound to SW1990 cells with high expression of hedgehog antigen, but no specific binding was detected in CFPAC-1 cells which lack the hedgehog antigen. The nano ultrasound contrast agent prepared by emulsification and volatilization method can be potentially used for the diagnosis of pancreatic cancer.

[Preparation and evaluation of a novel liposome-based fluorescent probe for tumor imaging].

In this study, a fluorescent nanoprobe based on liposome was synthesized by the hydrophobic interaction of phosphatidyl ethanolamine and indocyanine green(ICG).The nanoprobe was called LipoICG. In order to enhance the stability of liposome, we made a new LipoICG by coating it with human serum albumin (HSA). The new fluorescent nanoprobe, H-LipoICG, was produced for tumor imaging. The LipoICG and H-LipoICG were observed as spherical shape with uniform size distribution. The particle size of LipoICG was 94.47 nm, zeta potential was-43.5 m V and encapsulation efficiency (EE) was 81.5%.The particle size of H-LipoICG was 121.5 nm, zeta potential was-32.3 m V and EE was 98.2%.The coating of HSA could enhance the stability of liposome and increase the EE of ICG. Studies on drug release demonstrated that the release of ICG in H-LipoICG was slower than LipoICG, which suggests that HSA may reduce the ICG leakage from liposome, the fluorescence intensity could be enhanced in the nanoprobe. The Cell Counting Kit-8 assay demonstrated that LipoICG and H-LipoICG was not toxic for MCF-7 cells with good biocompatibility. In the study of biodistribution in mice, our experiments demonstrated that H-LipoICG had better tumor targeting ability and exhibited an enhanced fluorescence intensity than LipoICG. An optimize tumor contrast was observed after 8 h intravenous administration, the tumor margins could be clearly detected for up to 24 h after injection. So, H-LipoICG was an effective fluorescent probe for tumor imaging.