The effect of ultrasonication on the immunomodulatory activity of low-quality ginseng.

This study investigated the effects of ultrasonication extraction (UE) on the immunomodulatory activity of low-quality ginseng. The results indicate that the optimal conditions for extracting low-quality ginseng are ultrasonication at 60 kHz and 85°C for 60 min. The extraction yield from the UE was 20% higher than that of the water extraction (WE) at 100°C. The low quality ginseng obtained from the UE exhibited relatively low cytotoxicity toward normal human cells, with an observed toxicity of 15-18% at a concentration of 1.0 mg/mL. The ginseng product obtained following UE induced human B and T cells growth and resulted in concentrations of up to 9.33 × 10(4) cells/mL and 15.33 × 10(4) cells/mL, respectively. The ginseng extract also increased the secretion of interleukin-6 and tumor necrosis factor-α from these cells by up to 35%, and natural killer/ cell growth was also improved by up to 30%. The UE effectively released 2- to 3-fold higher levels of ginsenosides than the WE. Specifically, the obtained levels of Rb(1) , Re, and Rg(1) , which are likely immunomodulatory factors, were approximately three times higher after ultrasonication than after WE. These results were further supported by the finding that UE product-treated macrophages produced higher levels of nitric oxide (21 µM) than macrophages treated with the WE product or with standard ginsenosides. These results demonstrate that this optimized ultrasonication process effectively destroyed the more rigid cell walls of low-quality ginseng and released high levels of ginsenosides. This work is the first to correlate extraction parameters with both extraction yields and biological activity. The use of low-quality ginseng can thus be expanded by utilizing a low-temperature ultrasonic extraction process.

Enhancement of lipid extraction from marine microalga, Scenedesmus associated with high-pressure homogenization process.

Marine microalga, Scenedesmus sp., which is known to be suitable for biodiesel production because of its high lipid content, was subjected to the conventional Folch method of lipid extraction combined with high-pressure homogenization pretreatment process at 1200 psi and 35°C. Algal lipid yield was about 24.9% through this process, whereas only 19.8% lipid can be obtained by following a conventional lipid extraction procedure using the solvent, chloroform:methanol (2:1, v/v). Present approach requires 30 min process time and a moderate working temperature of 35°C as compared to the conventional extraction method which usually requires >5 hrs and 65°C temperature. It was found that this combined extraction process followed second-order reaction kinetics, which means most of the cellular lipids were extracted during initial periods of extraction, mostly within 30 min. In contrast, during the conventional extraction process, the cellular lipids were slowly and continuously extracted for >5 hrs by following first-order kinetics. Confocal and scanning electron microscopy revealed altered texture of algal biomass pretreated with high-pressure homogenization. These results clearly demonstrate that the Folch method coupled with high-pressure homogenization pretreatment can easily destruct the rigid cell walls of microalgae and release the intact lipids, with minimized extraction time and temperature, both of which are essential for maintaining good quality of the lipids for biodiesel production.

Drop-on-demand printing of carbon black ink by electrohydrodynamic jet printing.

Electrohydrodynamic (EHD) jet printing is a technique using electric fields to eject inks through nozzle apertures. EHD jet printing is very attractive due to its non-contacting nature and compatibility with diverse materials and substrates. In this research, we have fabricated micron-sized dot arrays and line patterns with carbon black ink on Si wafer substrates using EHD jet printing. The effect of operating conditions such as applied voltage, working distance and stage speed on the size and shape of the jetted patterns and jetting cycles is investigated by using optical microscope, high speed camera and atomic force microscopy (AFM). We have also demonstrated the drop-on-demand feature of the EHD jet printing system by patterning carbon black ink lines with various widths and dot arrays with desired diameters and spacing by controlling the operating conditions.

Direct-patterning of porphyrin dot arrays and lines using electrohydrodynamic jet printing.

In this research, we have fabricated micron-sized patterns of porphyrins on silicon substrates using an electrohydrodynamic (EHD) jet printing technique. Optical and fluorescence microscopies have been used to examine the shape and fluorescence property of porphyrin patterns. The morphology of the porphyrin patterns printed with variously formulated porphyrin inks and the effects of applied voltage, working distance, and substrate properties on the morphology of patterns were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). We have also demonstrated the acid-vapor sensing capability of the porphyrins by exposing the porphyrin patterns on Si substrates to nitric acid vapor.