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Sheng L.,Soochow University of China | Wang L.,Soochow University of China | Su M.,Soochow University of China | Su M.,Suzhou Environmental Monitor Center | And 9 more authors.
Environmental Toxicology | Year: 2016

Zebrafish (Danio rerio) has been used historically for evaluating the toxicity of environmental and aqueous toxicants, and there is an emerging literature reporting toxic effects of manufactured nanoparticles (NPs) in zebrafish embryos. Few researches, however, are focused on the neurotoxicity on adult zebrafish after subchronic exposure to TiO2 NPs. This study was designed to evaluate the morphological changes, alterations of neurochemical contents, and expressions of memory behavior-related genes in zebrafish brains caused by exposures to 5, 10, 20, and 40 μg/L TiO2 NPs for 45 consecutive days. Our data indicated that spatial recognition memory and levels of norepinephrine, dopamine, and 5-hydroxytryptamine were significantly decreased and NO levels were markedly elevated, and over proliferation of glial cells, neuron apoptosis, and TiO2 NP aggregation were observed after low dose exposures of TiO2 NPs. Furthermore, the low dose exposures of TiO2 NPs significantly activated expressions of C-fos, C-jun, and BDNF genes, and suppressed expressions of p38, NGF, CREB, NR1, NR2ab, and GluR2 genes. These findings imply that low dose exposures of TiO2 NPs may result in the brain damages in zebrafish, provide a developmental basis for evaluating the neurotoxicity of subchronic exposure, and raise the caution of aquatic application of TiO2 NPs. © 2014 Wiley Periodicals, Inc. Source

Su M.,Soochow University of China | Su M.,Suzhou Environmental Monitor Center | Sheng L.,Soochow University of China | Zhao X.,Soochow University of China | And 14 more authors.
Toxicology Research | Year: 2015

Background: Titanium dioxide nanoparticles (TiO2 NPs) have been widely used in industry and daily life; their potential neurotoxic effects are of great concern. The aim of this study is to determine whether exposure to TiO2 NPs mediates neurotrophins and related receptor expression in the hippocampus of mice under TiO2 NPs-induced neuroinflammation. Methods: Mice were nasally administered with 0.25, 0.5, or 1 mg per kg body weight TiO2 NPs for nine months. How neurotrophin-related factors and signaling pathways might be affected by exposure to TiO2 NPs for nine months using real-time PCR and ELISA methods were investigated. Results: The results suggest that exposure to TiO2 NPs caused TiO2 NPs deposition, excessive proliferation of all glial cells and tissue necrosis in the hippocampus. The hippocampal injury due to TiO2 NPs exposure was closely associated with significant reduction in nerve growth factor, brain-derived neurotrophic factor, tyrosine kinases (Trk A, B), calcium/calmodulin-dependent protein kinases (CaMKII, CaMKIV), cyclic-AMP responsive element binding proteins (CREB-1, CREB-2), dopamine receptors (D1, D2) and Tyrosine hydroxylase expression in the hippocampus. Conclusions: The findings imply that long-term exposure to TiO2 NPs may induce neuroinflammation via impairing neurotrophin-mediated signaling pathways in animals. This journal is © The Royal Society of Chemistry 2015. Source

Shi H.-C.,Tsinghua University | Song B.-D.,Tsinghua University | Long F.,Renmin University of China | Zhou X.-H.,Tsinghua University | And 3 more authors.
Environmental Science and Technology | Year: 2013

The accelerated eutrophication of surface water sources and climate change have led to an annual occurrence of cyanobacterial blooms in many drinking water resources. To minimize the health risks to the public, cyanotoxin detection methods that are rapid, sensitive, real time, and high frequency must be established. In this study, an innovative automated online optical biosensing system (AOBS) was developed for the rapid detection and early warning of microcystin-LR (MC-LR), one of the most toxic cyanotoxins and most frequently detected in environmental water. In this system, the capturing molecular MC-LR-ovalbumin (MC-LR-OVA) was covalently immobilized onto a biochip surface. By an indirect competitive detection mode, samples containing different concentrations of MC-LR were premixed with a certain concentration of fluorescence-labeled anti-MC-LR-mAb, which binds to MC-LR with high specificity. Then, the sample mixture was pumped onto the biochip surface, and a higher concentration of MC-LR led to less fluorescence-labeled antibody bound onto the biochip surface and thus to lower fluorescence signal. The quantification of MC-LR ranges from 0.2 to 4 μg/L, with a detection limit determined as 0.09 μg/L. The high specificity and selectivity of the sensor were evaluated in terms of its response to a number of potentially interfering cyanotoxins. Potential interference of the environmental sample matrix was assessed by spiked samples, and the recovery of MC-LR ranged from 90 to 120% with relative standard deviation values <8%. The immunoassay performance of the AOBS was validated with respect to that of conventional high-performance liquid chromatography, and the correlation between methods agreed well (R2 = 0.9762). This system has successfully been applied to long-term, continuous determination and early warning for MC-LR in Lake Tai from June 2011 to May 2012. Thus, the AOBS paves the way for a vital routine online analysis that satisfies the high demand for ensuring the safety of drinking water sources. The AOBS can also serve as early warning system for accidental or intentional water pollution. © 2013 American Chemical Society. Source

Dai C.-Y.,Tsinghua University | Wu J.,Tsinghua University | Xiang X.,Tsinghua University | Xie C.-B.,Tsinghua University | And 3 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2013

The present paper studied fluorescence fingerprint properties of the municipal wastewater with industrial wastewater as major components. There existed three typical fluorescence peaks in the excitation-emission matrix of the municipal wastewater, locating at about λex/λem of 275/310, 230/340 and 220/310 nm respectively. The wastewater didn't display typical protein-like fluorescence as the municipal wastewater with domestic sewage as major component. The fluorescence intensity of the wastewater was quite high with remarkable difference between workday and weekend. These might relate to the high content of industrial wastewater. The advantages of the fluorescence fingerprint such as easy and fast measurement and rich information about the components of wastewater make it a novel tool in water quality monitoring and early-warning. Source

Wang S.-F.,Southwest University | Wang S.-F.,Tsinghua University | Wu J.,Tsinghua University | Cheng C.,Tsinghua University | And 4 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015

Aqueous fingerprint has an advantage to represent the organic components of water samples as compared to traditional parameters such as chemical oxygen demand (COD) and total organic carbon (TOC). Printing and dyeing wastewater is one of the major types of industrial wastewater in China. It is of huge volume and heavy pollution, containing large numbers of luminescent components and being difficult to be degraded. In this study the aqueous fingerprint of printing and dyeing wastewater was investigated with the fluorescent spectrometry. The experimental results showed that there existed two peaks in the aqueous fingerprint of the printing and dyeing wastewater, locating at the excitation/emission wavelength around 230/340 nm and 280/310 nm respectively. The intensity of the excitation/emission wavelength at 230/340 nm was higher than that of 280/310 nm. The locations and intensities of peaks varied within small range. The intensities of the two peaks linearly correlated with coefficient of 0.9108 and slope of 1.506. The intensity ratio of Peak at 280/310 nm to Peak at 230/340 nm averagely was 0.777, ranging between 0.712 and 0.829. It was found that the aqueous fingerprints of sewage and aniline compounds were significantly different from that of the printing and dyeing wastewater, but the aqueous fingerprints of several types of widely-used dye were similar to that of the printing and dyeing wastewater. Thus dye may be the main luminescent components in the wastewater. The aqueous fingerprint can be used as a novel tool of early warning of waterbodies. © 2015, Science Press. All right reserved. Source

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