Ratiometric fluorescence probe integrated with smartphone for visually detecting lipopolysaccharide.

A portable instrument-free detection method for lipopolysaccharide (LPS) analysis was developed based on dual-emission ratiometric fluorescence sensing system. Herein, red-emitting Au nanoclusters (Au NCs) were as reference probe, while blue-emitting fluorescent silica quantum dots (Si QDs) were as response probe. Additionally, the aptamer of LPS was covalently grafted to the surface of Si QDs in order to specific recognize the LPS. According to the changes of fluorescence intensityratio (FL ratio, I461 nm/I643 nm) with the concentrations of LPS, the linear equation was fitted with the range of 50-3000 ng/mL, and the limit of detection (LOD) was 29.3 ng/mL. As a practical application, this method was employed to analyze LPS in normal saline with the recovery rate of 97.7-103.8 %. The color picker platform in the smartphone was used to transform the detection picture to the process of Red, Green and Blue (RGB) for visual detection of LPS. The low-cost and easy-carry method reported here presents broad merits for the visually quantitative detection of LPS.

Association between irritable bowel syndrome and micronutrients: A systematic review.

BACKGROUND AND AIM: Irritable bowel syndrome (IBS) is a highly prevalent disorder of gut brain interaction with a multifactorial etiology. Food trigger avoidance is common among individuals with IBS and exclusion diets are gaining popularity. However, recent guidelines on IBS management cautioned regarding the use of unsupervised dietary therapy with concerns of development of poor eating habits and even nutritional deficiencies. We aimed to review the available literature on the effect of habitual and exclusion diets on micronutrient status as well as the role of micronutrient supplementation in alleviating IBS symptoms. METHODS: Four electronic databases (PubMed, Embase, Cochrane, Web of Science) were searched for articles that reported micronutrient data in patients with IBS. Serum micronutrient levels and dietary intake of micronutrients in patients with IBS were collected. The extracted data were tabulated and organized by micronutrient type to observe for trends. RESULTS: Twenty-six articles were included in this systematic review (12 interventional and 14 observational studies). Studies showed that generally IBS subjects had lower levels of vitamin B2, vitamin D, calcium, and iron at baseline compared with non-IBS subjects. Studies also found that exclusion diets were associated with lower intake of micronutrients especially vitamin B1, B2, calcium, iron, and zinc. There was a lack of interventional studies on micronutrients. CONCLUSION: Irritable bowel syndrome patients are at risk of developing multiple micronutrient deficiencies that may have both localized gastrointestinal as well as systemic effects. Dietary management of IBS patients should include a proper dietitian review to ensure nutritional adequacy where possible.

Optical trapping and manipulation of metallic micro/nanoparticles via photorefractive crystals.

A simple method to trap and manipulate metallic micro/nano-particles on the surface of photorefractive crystals is proposed. After inducing inhomogeneous charge density and space-charge fields in photorefractive crystals by non-uniform illumination, both uncharged and charged metallic particles can be trapped on the illuminated surface due to dielectrophoretic force and electrophoretic force, respectively. A transition from dielectrophoresis to electrophoresis is observed when manipulating nano-silver particles with high surface space-charge field. Our results show that this method is simple and effective to form surface microstructures of metallic particles.