Electropolymerization of single-walled carbon nanotubes composited with polypyrrole as a solid-phase microextraction fiber for the detection of acrylamide in food samples using GC with electron-capture detection.

We developed a solid-phase microextraction coupled to GC with electron-capture detection method for the detection of acrylamide in food samples. Single-walled carbon nanotubes and polypyrrole were electropolymerized onto a stainless-steel wire as a coating, which possessed a homogeneous, porous, and wrinkled surface, chemical and mechanical stability, long lifespan (over 300 extractions), and good extraction efficiency for acrylamide. The linearity range between the signal intensity and the acrylamide concentration was found to be in the range 0.001­1 µg/mL, and the coefficient of determination was 0.9985. The LOD, defined as three times the baseline noise, was 0.26 ng/mL. The reproducibility for each single fiber (n = 6) and the fiber-to-fiber (n = 5) repeatability prepared in the same batch were less than 4.1 and 11.2%, respectively.

A simple colorimetric device for rapid detection of Hg2+ in water.

A 'turn-on' fluorescent colorimetric device for Hg(2+) sensing was built using a dual light-emitting diode system. Fluorescence generated from a rhodamine derivative (RHD), an indicator for Hg(2+) sensing, was combined with a background red light, and the complex light was captured by a commercial charge coupled device camera or by the naked eye.

Effectiveness of Yi-Zhi-An-Shen granules on cognition and sleep quality in older adults with amnestic mild cognitive impairment: protocol for a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Amnestic mild cognitive impairment (aMCI) is a syndrome characterized by significant forgetfulness that does not meet the criteria of dementia. Individuals with aMCI are at greater risk of progressing to dementia. Current studies suggest that good sleep quality is linked with preserved cognition in the elderly, and sleep complaints are common among the elderly with amnesia. Therefore, improving their sleep may be helpful for maintaining and improving their cognitive capacity. According to the theory of traditional Chinese medicine, Yi-Zhi-An-Shen is an herbal compound which may ameliorate forgetfulness and sleep disorders. As growing evidence indicates that the gut microbiome is associated with major mental symptoms, a hypothesis was proposed that Yi-Zhi-An-Shen granules (YZASG) might work by alternating microbial abundance and diversity. In this study, the investigators intend to assess the efficacy of YZASG on global cognition in the elderly suffering from aMCI and evaluate its safety as well as its potential mechanisms via sleep quality, fecal microbial 16S ribosomal DNA and metagenomics analyses, and serum markers. METHODS/DESIGN: This study is a randomized, double-blind, placebo-controlled clinical trial. A total of 80 patients (aged 60-85 years) will be recruited and allocated randomly to a treatment group and a placebo group in a 1:1 ratio and will then be administered YZASG or isodose placebo three times a day. The intervention course is 16 weeks, with an 18 months follow-up. The primary outcome is the Alzheimer's Disease Assessment Scale-Cognitive Subscale. Secondary outcome measures are the Mini-Mental State Examination, Montreal Cognitive Assessment, Pittsburgh Sleep Quality Index, serum concentrations of immunological factors and inflammatory cytokines, and fecal microbiota. Fecal microbiota will only be collected at the baseline and endpoint of the intervention. DISCUSSION: The results of this trial will be conducive to assessing the safety and effectiveness on cognition of YZASG in intervening aMCI among the elderly and determining if it takes effect via the improvement of sleep quality, regulation of gut microbiota, and concentration of certain serum markers. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03601000 . Registered on 26 July 2018.

Determination of nerolidol in teas using headspace solid phase microextraction-gas chromatography.

Nerolidol is an important volatile compound found in tea aroma, consumption of which has been associated with good health. A novel approach for the quantitative determination of nerolidol in teas has been developed using a headspace solid phase microextraction (HS-SPME) and a gas chromatography-flame ionization detector (GC-FID). The experimental parameters relating to the extraction efficiency of the HS-SPME such as fibre types, extraction temperature, extraction time, stirring rate were investigated and optimized. The study results demonstrated that combining GC-FID with HS-SPME was an efficient and flexible extraction approach for the analysis of nerolidol in teas. Using the HS-SPME-GC-FID, the linear range of the determination of nerolidol was found to be 2.7-1360 ng g(-1) and the limit of detection was 0.3 ng g(-1). The average recoveries were in the range 78.7-106% in spiked tea samples. In addition, the generation and the content change in nerolidol at different manufacturing stages were investigated. Based on the content of nerolidol in Oolong tea samples, grade judgment for the various teas was performed.