The application of novel electrosynthesized polydopamine (PDA)-imprinted film as a recognition element for the capacitive sensing of nicotine is reported. The PDA-imprinted film was electropolymerized directly on the gold electrode surface in the presence of nicotine without an additional self-assembled thiol sublayer. The compact PDA film has various functional groups that aid the imprinting procedure. Furthermore, the film shows good capacitive response since it is insulating in nature and ultrathin. The sensor's linear response range for nicotine was between 1-25 micromol L(-1), with a detection limit of 0.5 micromol L(-1). The proposed molecularly imprinted polymer capacitive (MIPC) sensor exhibited good selectivity for nicotine. The reproducibility and repeatability of the MIPC sensor were all found to be satisfactory. The results from sample analysis confirmed the applicability of the MIPC sensor to quantitative analysis.

A simple, sensitive, and reliable method based on a combination of multi-walled carbon nanotubes with incorporated beta-cyclodextrin (beta-CD-MWNTs) and a polyaniline (PANI) film-modified glassy-carbon (GC) electrode has been successfully developed for determination of dopamine (DA) in the presence of ascorbic acid (AA). The PANI film had good anti-interference properties and long-term stability, because of the permselective and protective properties of the conducting redox polymer film. The acid-treated MWNTs with carboxylic acid functional groups promoted the electron-transfer reaction of DA and inhibited the voltammetric response of AA. Sensitive detection of DA was further improved by the preconcentration effect of formation of a supramolecular complex between beta-CD and DA. The analytical response of the beta-CD-MWNTs/PANI film to the electrochemical behavior of DA was, therefore, better than that of a MWNTs/PANI film, a PANI film, or a bare glassy-carbon (GC) electrode. Under the conditions chosen a linear calibration plot was obtained in the range 1.0 x 10(-7)-1.0 x 10(-3) mol L(-1) and the detection limit was 1.2 x 10(-8) mol L(-1). Interference from AA was effectively eliminated and the sensitivity, selectivity, stability, and reproducibility of the electrodes was excellent for determination of DA.

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BackgroundObesity is a key public health problem. The advancement of gut microbiota research sheds new light on this field. This article aims to present the research trends in global intestinal microbiota studies within the domain of obesity research.MethodsBibliographic information of the publications on intestinal microbiota and obesity was retrieved from the Scopus database, and then analyzed by using bibliometric approaches.ResultsA total of 3,446 references were retrieved; the data indicated a steady growth and an exponential increase in publication numbers. The references were written in 23 different languages (93.8% in English). A number of 3,056 English journal papers were included in the further analyses. Among the 940 journals, the most prolific ones were PLOS ONE, Scientific Reports, and British Journal of Nutrition. North America and Europe were the highest publication output areas. The US (995 publications) ranked first in the number of publications, followed by the China (243 publications) and France (242 publications). The publication numbers were significantly correlated with gross domestic product (GDP), human development index (HDI), and population number (PN). International collaboration analysis also shows that most of the collaborations are among developed countries.DiscussionThis comprehensive bibliometric study indicates that gut microbiota is a significant topic in the obesity research. The structured information may be helpful in understanding research trends, and locating research hot spots and gaps in this domain.

Ginsenoside Rb1, a major component of different ginseng species, can be bioconverted into compound K by gut microbiota, and the latter possess much stronger cancer chemopreventive potential. However, while the initiation and progression of colorectal cancer is closely associated with gut inflammation, to date, the effects of compound K on inflammation-linked cancer chemoprevention have not been reported. In the present study, liquid chromatography quadrupole time-of-flight mass spectrometry analysis was applied to evaluate the biotransformation of Rb1 in American ginseng by human enteric microflora. The in vitro inhibitory effects of Rb1 and compound K were compared using the HCT-116 and HT-19 human colorectal cancer cell lines by a MTS assay. Cell cycle and cell apoptosis were assayed using flow cytometry. Using ELISA, the anti-inflammatory effects of Rb1 and compound K were compared for their inhibition of interleukin-8 secretion in HT-29 cells, induced by lipopolysaccharide. The results revealed that compound K is the major intestinal microbiome metabolite of Rb1. When compared with Rb1, compound K had significantly stronger anti-proliferative effects in HCT-116 and HT-29 cell lines (P<0.01). Compound K significantly arrested HCT-116 and HT-29 cells in the G1 phase, and induced cell apoptosis (P<0.01). By contrast, Rb1 did not markedly influence the cell cycle or apoptosis. Furthermore, compound K exerted significant anti-inflammatory effects even at low concentrations (P<0.05), while Rb1 did not have any distinct effects. The data obtained from the present study demonstrated that compound K, an intestinal microbiome metabolite of Rb1, may have a potential clinical value in the prevention of inflammatory-associated colorectal cancer.

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Background Hepatocellular carcinoma (HCC) with high heterogeneity is one of the most frequent malignant tumors throughout the world. However, there is no research to establish a ferroptosis-related lncRNAs (FRlncRNAs) signature for the patients with HCC. Therefore, this study was designed to establish a novel FRlncRNAs signature to predict the survival of patients with HCC. Method The expression profiles of lncRNAs were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. FRlncRNAs co-expressed with ferroptosis-related genes were utilized to establish a signature. Cox regression was used to construct a novel three FRlncRNAs signature in the TCGA cohort, which was verified in the GEO validation cohort. Results Three differently expressed FRlncRNAs significantly associated with prognosis of HCC were identified, which composed a novel FRlncRNAs signature. According to the FRlncRNAs signature, the patients with HCC could be divided into low- and high-risk groups. Patients with HCC in the high-risk group displayed shorter overall survival (OS) contrasted with those in the low-risk group (P < 0.001 in TCGA cohort and P = 0.045 in GEO cohort). This signature could serve as a significantly independent predictor in Cox regression (multivariate HR > 1, P < 0.001), which was verified to a certain extent in the GEO cohort (univariate HR > 1, P < 0.05). Meanwhile, it was also a useful tool in predicting survival among each stratum of gender, age, grade, stage, and etiology,etc. This signature was connected with immune cell infiltration (i.e., Macrophage, Myeloid dendritic cell, and Neutrophil cell, etc.) and immune checkpoint blockade targets (PD-1, CTLA-4, and TIM-3). Conclusion The three FRlncRNAs might be potential therapeutic targets for patients, and their signature could be utilized for prognostic prediction in HCC.