The development of a curcumin-based sensor for the detection of volatile amines (specifically known as total volatile basic nitrogen, TVBN) is described. Curcumin [(1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5dione] is the major yellow pigment extracted from turmeric, a commonly used spice, derived from the rhizome of the plant Curcuma longa. Curcumin was immobilized onto bacterial cellulose membrane via the absorption method. Thus, the sensing materials are edible and suitable for food applications. The curcumin/bacterial cellulose membrane as the TVBN sensor worked based on pH increase as the basic spoilage volatile amines produced gradually in the package headspace, and subsequently, the color of the sensor will change from yellow to orange, then to reddish orange for spoilage indication, which is easily visible to the naked eye. The curcumin membrane is a highly sensitive material toward acid–base reactions. Color changes, as a result of its interactions with increasing pH (as a result of increasing TVBN), were monitored directly with visual inspection and the color quantitatively measured with color analysis via Photoshop software. Furthermore, the membrane response was found to correlate with bacterial growth patterns in shrimp samples. Finally, the curcumin/bacterial cellulose membrane was successfully used as a sticker sensor for real-time monitoring of shrimp spoilage in ambient and chiller conditions. 相似文献
Utilization of biomass as a new and renewable energy source is being actively conducted by various parties. One of the technologies for utilizing or converting biomass as an energy source is pyrolysis, to convert biomass into a more valuable product which is bio-oil. Bio-oil is a condensed liquid from the vapor phase of biomass pyrolysis such as coconut shells and coffee shells. Biomass composition consisting of hemicellulose, cellulose, and lignin will oxidize to phenol which is the main content in bio-oil. The total phenolic compounds contained in bio-oil are 47.03% (coconut shell) and 45% (coffee shell). The content of phenol compounds in corrosive bio-oils still quite high, the use of this bio-oil directly will cause various difficulties in the combustion system due to high viscosity, low calorific value, corrosivity, and instability. Phenol compounds have some benefits as one of the compounds for floor cleaners and disinfectants which are contained in bio-oil.The correlation between experimental data and calculations shows that the UNIQUAC Functional-group Activity Coefficients (UNIFAC) equilibrium model can be used to predict the liquid–liquid equilibrium in the phenol extraction process of the coconut shell pyrolysis bio-oil. While the Non-Random Two Liquid (NRTL) equilibrium model can be used to predict liquid–liquid equilibrium in the extraction process of phenol from bio-oil pyrolysis of coffee shells. 相似文献
As a biocompatible porous material, bio-MOF is a very promising material as a carrier for hydrophobic drugs, including curcumin. However, the stability of bio-MOF against water and humidity still needs to be improved; therefore, surface modifications are required. This study aims to modify the MIL-100(Fe)-based bio-MOF through core–shell architecture by employing mesoporous silica nanoparticles (MSNs or SiO2) for improving the stability and performance of MIL-100(Fe) to provide a slow-release feature of curcumin. The composites were synthesized via sonochemistry-assisted or mechanochemistry-assisted green protocol to form core–shell structure of MIL-100(Fe)@SiO2 (Composite-1) or SiO2@MIL-100(Fe) (Composite-2). Structural, textural, and morphological analyses, including XRD, FTIR, SEM, TEM, and N2 adsorption–desorption, are discussed in this study to evaluate the composite formation. BET surface area of the MIL-100(Fe) decreased from 1197.45 m2/g to 565.63 and 823.70 m2/g after forming composite-1 and composite-2 with SiO2. The loading capacity, however, just increased slightly up to 97.89% after the modification. The presence of SiO2 as shell (composite-1) protects the MIL-100(Fe) from degradation under the acidic condition at pH 5.8 and can maintain the slow-release of curcumin. In contrast, the presence of SiO2 as core (composite-2) induces the sustained release due to faster degradation of MIL-100(Fe) in acidic condition. Both composites serve as a model for either sustained release or delayed release drug delivery systems.
A suspected epidemic of unknown etiology was investigated in April/May 1996 in the remote jungle highlands of easternmost Indonesia. Trend analysis demonstrates the area-wide occurrence of a major respiratory infection outbreak in November 1995 through February 1996. The monthly mean rate of respiratory infection episodes for the peak outbreak months (2,477 episodes/100,000 persons) was significantly higher (P < .0001) than for the 34 months leading up to the outbreak (109 episodes/100,000 persons). Notable were the high attack rates, particularly among adults: 202 episodes/1,000 persons aged 20-50 years in one community. Excess morbidity attributed to the outbreak was an estimated 4,338 episodes. The overall case-fatality rate was 15.1% of outbreak cases. Laboratory evidence confirmed the circulation of influenza A/Taiwan/1/86-like viruses in the study population, and high hemagglutination inhibition titer responses were indicative of recent infections. Historical documents from neighboring Papua New Guinea highlight the role of influenza A virus in repeated area outbreaks. 相似文献
In this research, the performance of metal–organic frameworks (MOFs) of MIL-101(Fe) and MOF-808 as aspirin detoxification agents was evaluated. MIL-101(Fe) was successfully prepared for the first time using the electrochemical method for 30 min under room temperature and pressure. MIL-101(Fe) detoxification capacity was compared to that of MOF-808, which was synthesized by a common solvothermal method at 135 °C for 24 h. The obtained materials were fully confirmed by X-ray diffraction (XRD) with the appearance of MIL-101(Fe) characteristic peaks (at 2θ 8.5°; 9°;16.7°) and MOF-808 (at 2θ 8.3°; 8.7°; 10°; 10.9°), and also confirmed by Fourier transform infrared (FTIR) spectroscopy that shows the coordination between metal and ligand. Based on scanning electron and transmission electron microscopy (SEM and TEM), MIL-101(Fe) has a micro-spindle shape with average particles size of 649.12?±?73.32 nm, while MOF-808 showed irregular shape with average particle sizes of 169.73?±?31.87 nm. Nitrogen sorption isotherm confirmed that both materials could be classified as micro to-meso porous materials by the pore radius of 1.89 nm for each materials with BET surface areas of 131 for MIL-101(Fe), and 847 m2/g for MOF-808, respectively. Based on an in vitro test, in a gastric simulation, MIL-101(Fe) decreased 11.78% of aspirin, while MOF-808 decreased 7.99%. In the intestinal simulation, MIL-101(Fe) and MOF-808 decreased aspirin by 24.06% and 26.74%, respectively. XRD analysis of the MOFs after the detoxification test showed that MIL-101(Fe) has lower stability than MOF-808. FTIR spectra confirmed that aspirin was successfully adsorbed into the MOFs. Transmission electron microscopy showed that aspirin interacted with MIL-101(Fe) on the outer surface and with MOF-808 on the inside of the pores.
