Study of Drug Metabolism by Xanthine Oxidase

In this work, we report the studies of drug metabolism by xanthine oxidase (XOD) with electrochemical techniques. Firstly, a pair of stable, well-defined and quasi-reversible oxidation/reduction peaks is obtained with the formal potential at −413.1 mV (vs. SCE) after embedding XOD in salmon sperm DNA membrane on the surface of pyrolytic graphite electrode. Then, a new steady peak can be observed at −730 mV (vs. SCE) upon the addition of 6-mercaptopurine (6-MP) to the electrochemical system, indicating the metabolism of 6-MP by XOD. Furthermore, the chronoamperometric response shows that the current of the catalytic peak located at −730 mV increases with addition of 6-MP in a concentration-dependent manner, and the increase of the chronoamperometric current can be inhibited by an XOD inhibitor, quercetin. Therefore, our results prove that XOD/DNA modified electrode can be efficiently used to study the metabolism of 6-MP, which may provide a convenient approach for in vitro studies on enzyme-catalyzed drug metabolism

The TESS Objects of Interest Catalog from the TESS Prime Mission

We present 2241 exoplanet candidates identified with data from the Transiting Exoplanet Survey Satellite (TESS) during its 2 yr Prime Mission. We list these candidates in the TESS Objects of Interest (TOI) Catalog, which includes both new planet candidates found by TESS and previously known planets recovered by TESS observations. We describe the process used to identify TOIs, investigate the characteristics of the new planet candidates, and discuss some notable TESS planet discoveries. The TOI catalog includes an unprecedented number of small planet candidates around nearby bright stars, which are well suited for detailed follow-up observations. The TESS data products for the Prime Mission (sectors 1-26), including the TOI catalog, light curves, full-frame images, and target pixel files, are publicly available at the Mikulski Archive for Space Telescopes

OMFM: a framework of object merging based on fuzzy multisets

Information fusion is a process of merging information from multiple sources into a new set of information. Existing work on information fusion is applicable in various scenarios such as multiagent system, group decision making, and multidocument summarization. This paper intends to develop an effective framework to solve object merging problem based on fuzzy multisets. The objects defined in this paper are data segments in document fusion task, referring to the concepts with semantic-related terms of different semantic relations embedded. The fundamental operation is the merge function mapping data segments in multiple fuzzy multisets onto one object, which is a solution. Under this framework, we define quality measures of purity and entropy to quantify the quality of the solutions, balancing accurateness, and completeness of the results. Merge function that yields this kind of solutions is VI-optimal merge function and a series of theoretical properties concerning it are studied. Finally, we investigate the proposed framework in a special application scenario (i.e., document fusion) which is related to the task of multidocument summarization and show how the framework works with illustrative example

Heavy metal migration and risk transference associated with cyanobacterial blooms in eutrophic freshwater

The distribution of metals in cyanobloom-forming lakes, and potential risks of these metals during irrigation with water derived from the bloom were evaluated in this study. Seven metals were monitored throughout a cyanobacterial bloom season in Lake Taihu. Cyanobloom bio-dilution of the targeted metals could be explained by the negative relationships between total phytoplankton metal contents (Cu, Fe, Zn, Pb and Cr) and Chl a concentrations (p &lt; 0.05). Meanwhile, the ratios of extracellular bound to total cellular bound metals (Cu, Zn, Pb, Cr and Cd) were positively correlated with the ratios of cyanophyta to total phytoplankton (p &lt; 0.01), indicating the enhanced extracellular bound of these metals during cyanobloom period. Secondly, Cd, Pb and Cr were detected in several local vegetables. In comparison to reference vegetables, vegetables (e.g., radish, soybean, and cowpea), which were irrigated with cyanobloom broth collected from Lake Taihu, presented high health risk index (HRI) and were not safe for human consumption. Collectively, the frequent dominant colonial Microcystis blooms which performed high metal affinity might mediate the distribution of heavy metals in lake and potentially transferred these pollutants into terrestrial system. (C) 2017 Published by Elsevier B.V.</p

The ecological risks of hydrogen peroxide as a cyanocide: its effect on the community structure of bacterioplankton

Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide (H2O2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H2O2 has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H2O2 on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by Microcystis at a highly eutrophic Dianchi Lake, China. The results showed that Microcystis was more sensitive to H2O2 than other eukaryotic algae. More interestingly, application of H(2)O(2 )changed the community structure of bacterioplankton, evidenced by the emergence of Firmicutes as the dominant species in place of Bacteroidetes and Proteobacteria. The H2O2 treatment resulted in the community of bacterioplankton that was primarily dominated by Exiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H2O2 reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H(2)O(2 )to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment.</p

Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma.

125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost

theecologicalrisksofhydrogenperoxideasacyanocideitseffectonthecommunitystructureofbacterioplankton

Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide (H2O2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H2O2 has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H2O2 on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by Microcystis at a highly eutrophic Dianchi Lake, China. The results showed that Microcystis was more sensitive to H2O2 than other eukaryotic algae. More interestingly, application of H(2)O(2 )changed the community structure of bacterioplankton, evidenced by the emergence of Firmicutes as the dominant species in place of Bacteroidetes and Proteobacteria. The H2O2 treatment resulted in the community of bacterioplankton that was primarily dominated by Exiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H2O2 reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H(2)O(2 )to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment

User relation prediction based on matrix factorization and hybrid particle swarm optimization

Many real-world domains are relational in nature, consisting of a set of objects related to each other in complex ways. Matrix factorization is an effective method in relationship prediction, However, traditional matrix factorization link prediction methods can only be used for non-negative matrix. In this paper, a generalized framework, itelliPrediction, is presented that is able to deal with positive and negative matrix. The novel itelliPrediction framework is domain independent and with high precision. We validate our approach using two different data sources, an open data sets and a real-word dataset, the result demonstrated that the quality of our approach is comparable to, if not better than, exiting state of the art relation predication framework

Multi-Year Assessment of Toxic Genotypes and Microcystin Concentration in Northern Lake Taihu, China

Lake Taihu is the third-largest freshwater lake in China and has been suffering from cyanobacterial blooms for over two decades. The northern part of the lake, Meiliang Bay, is known to be at high risk of dense and sustained Microcystis blooms and toxins. This study aimed to investigate and record the annual and seasonal dynamics of toxic genotype, Microcystis morphospecies succession and microcystin variation. It also aimed to find out the underlying driving factors influencing the dynamic changes. Microcystin (MC) and the Microcystis genotype were quantified using HPLC and quantitative real-time PCR, respectively. Our study, over three consecutive years, showed that the pattern of morphospecies succession was seasonally distinct and annually consistent. During the same period in 2012, 2013 and 2014, the average MC were, on dry weight basis, 733 μg·g−1, 844 μg·g−1, 870 μg·g−1, respectively. The proportion of toxic Microcystis accounted for 41%, 44% and 52%, respectively. Cell bound microcystin was found to correlate with the percentage of toxic Microcystis. Based on historical and current data, we conclude that annual bloom toxicity was relatively stable or possibly increased over the last decade