The purpose of this research was to develop a novel antimicrobial delivery system by encapsulating d -limonene into an organogel-based nanoemulsion and investigating its antimicrobial activity. The d -limonene organogel-based nanoemulsion was prepared by high pressure homogenization method. The surfactant concentration had a major impact on the droplets' formation and distribution. At the optimal condition (10% w/w Tween 80, 100 Mpa, and 10 Cycles) the smallest droplet size ( d ≈ 36 nm) could be obtained, which has shown a narrow structure and good stability. Results from the antimicrobial activity have shown the encapsulation of d -limonene (4% w/w) into the organogel-based nanoemulsion contributed to the increase of its antimicrobial activity. In addition, the mechanism of d -limonene organogel-based nanoemulsion against the tested microorganisms was studied by the electronic microscope observation and the cell constituent release. This research would have an important implication for the design of more efficient antimicrobial systems for food preservation and production.
Yiyin Chen,Xiaomin Yang,Lin Zhao,László Almásy,Vasil M. Garamus,Regine Willumeit,Aihua Zou
The aim of this study was to prepare a stable nanostructured lipid carrier (NLC) with biocompatible lipids and surfactants (Pluronic F68 and Cremophor EL) by high-pressure homogenization (HPH). Surface tension measurements were used to choose the suitable ratio between Pluronic F68 and Cremophor EL. Hydrophobic anticancer drug docetaxel (DTX) was used as an active pharmaceutical ingredient (API). The mean particle size of docetaxel loaded nanostructured lipid carrier (DTX-NLC), as determined by dynamic light scattering (DLS), was between 120 nm and 250 nm during the storage period of 30 days, with the entrapment efficiency decreasing from (60.5 ± 5.0)% to (55.3 ± 4.5)%, while zeta potential was slightly changed from (−43.19 ± 3.6) mV to (−40.12 ± 4.3) mV. Transmission electron microscopy (TEM) showed that some of DTX-NLCs have elongated shape. Small angle neutron scattering (SANS) demonstrated that DTX-NLC in solution contained dense core with perfectly smooth surface, while blank NLC had dense core but rough surface. The blank NLC and DTX-NLC showed cubic crystalline structure according to small angle X-ray scattering (SAXS). Wide angle X-ray diffraction (XRD) showed that adding of DTX increased the crystallinity of the NLC. Cytotoxicity was studied by MTT assay against Hela cells. The data suggested that blank NLC was biocompatible with HeLa cells while the DTX-NLC was more cytotoxic than pure DTX at the same drug concentration. DTX-NLC could be taken up into the cells more than pure DTX, which could be attributed to the better solubility of DTX after loading into NLC.
Asif Islam,Md Shafiullah,Amjad Ali,Md Shafiul Alam,Waleed Hamanah,Rabiul Alam
ISO/IEC 17025:2017 recommends all accredited laboratories under this standard, performing testing and calibration, shall identify and evaluate the contributions to the uncertainty of their measurements. This paper represents the results of the ‘measurement uncertainty’ assessment carried out on a partial discharge (PD) test set in our laboratory. The major sources of uncertainty include sampling error, calibrator inaccuracy, the resolution limit of display panels, temperature and humidity factors, etc. The uncertainty for each factor was calculated by the principles outlined in NIST-1297:1994 and JCGM-100:2008. The test PD levels were 1, 5, 10, 20, 50 and 100 pC. The combined uncertainty was calculated based on all uncertainty contributions, and the expanded uncertainties were expressed with 68%, 95% and 99% confidence level. Apparently, the measurement uncertainty was highest for the lowest test PD which decreased with the increase in PD level. The uncertainty was around 18% at 1 pC PD whereas it dropped to 2.84% at 100 pC PD. Within the whole test range of 5 to 100 pC, the maximum uncertainty was equal to 5.81%.
危险品化学品经营许可证（带存储）