250 research outputs found

    Visualisation of latent fingerprint on wild bird eggshells by alternate light sources following superglue fuming

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    The theft of the eggs of endangered or protected species of bird, and subsequent reduction in wildlife population, is a significant problem worldwide. Detection rates are comparatively low towards this type of crime and fingerprinting of egg shells is infrequently utilised due to the technical barrier. This paper explores a novel technique using cyanoacrylate (superglue) fuming in conjunction with fluorescent dye to visualise latent fingerprints upon avian eggshells assisted with alternate light sources. A systematic investigation of experimental parameters has also been carried out to optimise the condition for the fingerprint visualisation. This research project has successfully developed latent fingerprints upon smooth wild bird eggshells but was less successful on developing prints on more textured, porous eggshells.Published onlin

    Protein/polysaccharide intramolecular electrostatic complex as superior food-grade foaming agent

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    High-performance foaming agents are widely required in the food industry. In this study, the relationship between electrostatic interaction of whey protein isolate (WPI)/alginate (ALG) and the resultant foaming properties were investigated systematically. The phase diagram of WPI/ALG was established in terms of protein/polysaccharide mixing ratio (r) and pH. The results show that the foaming capacity of WPI/ALG complexes is almost the same across different regions of the phase diagram, while the foam stability varies significantly. At pHs 7.0 and 0.5 where no electrostatic complexation occurs, the foam stability is found to decrease monotonically with decreasing r. At pH 4.0 and particular mixing ratios, i.e., r = 1 and 2, intramolecular soluble complexes are formed and the particular WPI/ALG complexes yield the best foam stability, as compared to other electrostatic complexes or individual components. The half-life (t1/2) of the foams stabilized by the intramolecular electrostatic complexes is as long as 4000 s at a very low WPI/ALG concentration of 0.1% w/w. The foaming properties are in line with the foam viscosity, interfacial adsorption behavior and microstructures of the complexes observed at the air-water interface. This demonstrates that the protein/polysaccharide intramolecular electrostatic complex, more specifically at the stoichiometry, could potentially act as a superior foaming agent in the food industry

    Preparation and emulsifying properties of trace elements fortified gum arabic

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    Gum arabic was enriched with trace elements (Zn2+, Fe3+, Fe2+) by ion exchange against ZnCl2, FeCl3 and FeCl2. Trace elements content, molecular parameters and emulsifying properties of the gum arabic rich in trace elements (GARTE) were characterized by flame atomic absorption spectrometry (FAAS), gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), interfacial rheometer, laser particle analyzer and zeta potentiometry. With trace elements, molecular weight and arabinogalactan protein (AGP) content of gum arabic have increased probably due to the high surface energy leading to the aggregation of protein. GARTE has good emulsion stability performance with increasing molecular weight and AGP content compared to the control gum arabic. GARTE can be applied as a natural functional ingredient for trace element fortification, where the ferric ions and zinc ions are chelated by the self-assembled polymer host

    Loss of Jak2 Selectively Suppresses DC-Mediated Innate Immune Response and Protects Mice from Lethal Dose of LPS-Induced Septic Shock

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    Given the importance of Jak2 in cell signaling, a critical role for Jak2 in immune cells especially dendritic cells (DCs) has long been proposed. The exact function for Jak2 in DCs, however, remained poorly understood as Jak2 deficiency leads to embryonic lethality. Here we established Jak2 deficiency in adult Cre+/+Jak2fl/fl mice by tamoxifen induction. Loss of Jak2 significantly impaired DC development as manifested by reduced BMDC yield, smaller spleen size and reduced percentage of DCs in total splenocytes. Jak2 was also crucial for the capacity of DCs to mediate innate immune response. Jak2−/− DCs were less potent in response to inflammatory stimuli and showed reduced capacity to secrete proinflammatory cytokines such as TNFα and IL-12. As a result, Jak2−/− mice were defective for the early clearance of Listeria after infection. However, their potency to mediate adaptive immune response was not affected. Unlike DCs, Jak2−/− macrophages showed similar capacity secretion of proinflammatory cytokines, suggesting that Jak2 selectively modulates innate immune response in a DC-dependent manner. Consistent with these results, Jak2−/− mice were remarkably resistant to lethal dose of LPS-induced septic shock, a deadly sepsis characterized by the excessive innate immune response, and adoptive transfer of normal DCs restored their susceptibility to LPS-induced septic shock. Mechanistic studies revealed that Jak2/SATA5 signaling is pivotal for DC development and maturation, while the capacity for DCs secretion of proinflammatory cytokines is regulated by both Jak2/STAT5 and Jak2/STAT6 signaling

    Effect of arabinogalactan protein complex content on emulsification performance of gum arabic

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    The emulsification properties of the standard (STD), matured (EM2 and EM10) and fractionated gum arabic samples via phase separation induced molecular fractionation were investigated to find out how the content of arabinogalactan protein (AGP) complex affects the resulting emulsion properties. Phase separation and the accompanying molecular fractionation were induced by mixing with different hydrocolloids including hyaluronan (HA), carboxymethyl cellulose (CMC), and maltodextrin (MD). Increase of AGP content from 11 to 28% resulted in the formation of emulsions with relatively smaller droplet sizes and better stability. Further increase in the AGP content to 41% resulted in the formation of emulsions with larger droplets. In spite of the larger droplets sizes, these emulsions were extremely stable. In addition, the emulsions prepared with GA higher AGP content better stability in the presence of ethanol. The results indicate that AGP content plays a vital role in emulsion stability and droplet size

    Characterization of hydrophilic and hydrophobic core-shell microcapsules prepared using a range of antisolvent approaches

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    This study describes three straightforward approaches to leveraging gel network-restricted antisolvent precipitation techniques as a means of preparing hydrophilic hydrophobic core-shell microparticles. Briefly, hydrophilic polysaccharides (sodium alginate (ALG), κ-carrageenan (CAR), and agar (AG)) were utilized to prepare microgel beads that were then immersed in zein solutions (70% ethanol aqueous solution, 70% urea aqueous solution, and zein in 70% acetic acid, respectively), thereby facilitating the controlled, slow antisolvent precipitation of the protein layer on the microbead surfaces and inducing hydrophilic hydrophobic core-shell structure formation. This technique can be readily applied to a range of gelling systems and can be tailored to target particle sizes and shell thicknesses. The resultant core-shell particles offer great promise for controlled delivery of fragrances, drugs, or other bioactive compounds in an application-specific fashion, and can be individually tailored based upon the selected input concentrations and preparation methods. Importantly, this technique is generalizable and can be extended to prepare diverse particles with a range of core-shell structures produced from a wide assortment of hydrophobic materials
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