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We fabricated a new and selective fluorescent sensor for the detection of citrate by employing g-C3N4 quantum dots (g-CNQDs) and MgFe layered double hydroxide (MgFe-LDH). The g-CNQDs interacted with MgFe-LDH via electrostatic interaction and the fluorescence of g-CNQDs was effectively quenched by MgFe-LDH due to inner filter effect. Upon addition of citrate, the fluorescence of the g-CNQDs was significantly enhanced, arising from the replacement of g-CNQDs by citrate because citrate competed with g-CNQDs to form more stable complexes with MgFe-LDH. Therefore, we developed a "turn-off–on" fluorescence assay method for the detection of citrate. This method enabled the selective detection of citrate with linear range of 0.5–3.0 μM and 3.0–10.0 μM with a 12.3 nM limit of detection. This method exhibited advantages including easy preparation, environmentally friendly process and rapid response toward citrate. [ABSTRACT FROM AUTHOR]

miR-25 was identified as an essential oncogene by promoting the growth and metastasis through TOB1 in gastric cancer (GC). The function of the single nucleotide polymorphism (SNP) located in the mature region of miR-25 (rs41274221) has not been investigated. In this study, we aimed to explore the involvement of rs41274221 in miR-25 in gastric cancer. We found that SNP rs41274221 in miR-25 was participated in the occurrence of GC by acting as a tumor protective factor associating with the tumor growth and metastasis. Besides, further investigation found that upregulation of miR-25 with AA genotype could attenuate the proliferation and invasion of tumor cells caused by wild-type miR-25. The dual-luciferase reporter assay also confirmed that miR-25 harbored the A allele which caused an incapacitation of binding at the TOB1. In conclusion, rs41274221 in miR-25 was a subgroup which may protect the patients from further growth and metastasis of gastric cancer and might serve as a novel biomarker for the disease. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates that abnormal microRNA (miRNA) expression is related to hepatocellular carcinoma (HCC) development. Our study aimed to elucidate the essential role of miR-329 in HCC progression. Real-time PCR was used to analyze miR-329 and bromodomain containing 4 (BRD4) expression in HCC samples ( n = 135). Cell Counting Kit-8 (CCK-8) and flow cytometric analysis were used to investigate cell proliferation and apoptosis. The transwell assay was used to examine the cell invasive ability. The regulation mechanism was confirmed by luciferase reporter and western blot assays. Kaplan-Meier analysis was used to detect the function of miR-329 on the prognosis of HCC patients. miR-329 was decreased in HCC samples and was related to tumor development. Furthermore, miR-329 significantly regulated cell invasion by targeting BRD4 but had no effect on cell proliferation and apoptosis. Moreover, downregulation of miR-329 predicted poor prognosis of HCC patients. miR-329 could control cell invasion via regulating BRD4 expression and may be a prognostic marker in HCC. [ABSTRACT FROM AUTHOR]

Brucellosis is a common zoonotic infection worldwide and a major public health problem in developing countries including China. The aim of our study was to investigate the seroprevalence of Brucella infection in humans in Yixing, located at the centre of the Yangtze River Delta Urban Agglomeration. A total of 895 sera from apparently healthy abattoir workers and 3303 sera from general healthy people living in rural areas were collected in Yixing, screened by Rose-Bengal plate agglutination test (RBPT) and the positives were confirmed by standard tube agglutination test (SAT) according to official Chinese diagnostic criteria. Seropositivity among abattoir workers was 16.42% compared to zero among the general population living in rural areas. No significant difference of seropositivity was observed in age groups. Contact or inhalation of Brucella organisms from infected animals, principally goats, was found to be a significant risk factor. Education in occupational hygiene and public healthcare programmes are needed to control this emerging problem. [ABSTRACT FROM AUTHOR]

Morphological, thermal, and mechanical features of electrosprayed and electrospun deposition of the silk-inspired polyurethane (PU) containing GlycineAlanineGlycineAlanine (GlyAlaGlyAla, the featured peptide sequence of silkworm silk fibroin) tetrapeptide, which was synthesized by the traditional liquid-phase peptide synthesis method and the classical two-step polymerization method using Boc-protected amino acids and diisocyanates as starting materials, were characterized. The results show that the synthesized silk-inspired PU dissolved in tetrahydrofuran (THF) can be easily electrosprayed or electrospun into the film form, although its molecular weight ranging from 13,000 to 15,000 is quite low. Elastomeric fibrous membranes with surface morphologies of 'droplets,' 'bead-on-string,' and 'nonwoven fibers' have been obtained by electrospraying and electrospinning the silk-inspired PU/THF solution of varying concentrations. The thermograms confirm high thermostability of the silk-inspired PU between 350 and 400°C due to the polar peptide linkages. The tanδ peak of dynamic mechanical analysis curve corresponding to its glass transition temperatures is detected at −34.3°C. Its elongation at break is about 140-150%, and the breaking tensile strength ranges from 22 to 27 MPa, which is consistent with the data of other PUs containing l-alanine residue. Information provided by this study can be used to better understand the correlation between the natural and man-made silk polymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40245. [ABSTRACT FROM AUTHOR]

A composite (Ag-g-CNQDs) was prepared from graphitic carbon nitride quantum dots and silver nanoparticles by water phase synthesis. Aided by metal-enhanced fluorescence, the composite exhibits excitation-dependent red emission with a peak at 600 nm with a quantum yield of 21%. If the composite is coated with polyethylenimine (PEI) to form the Ag-g-CNQD/PEI complexe, fluorescence is strongly reduced. Upon addition of heparin, the fluorescence of the system is enhanced because PEI has a higher affinity for heparin than Ag-g-CNQDs. The effect was used to design a fluorometric  assay for heparin. The emission at 600 nm increases linearly in the 0.025 to 2.5 μM heparin concentration range, with a 8.2 nM limit of detection.Schematic illustration for fabricating a composite consisting of silver nanoparticles and graphitic carbon nitride quantum dots (Ag-g-CNQDs). Its red fluorescence is weak in presence of polyethyleneimine but restored on addition of heparin. This forms the basis for a new method for heparin detection. [ABSTRACT FROM AUTHOR]