73 research outputs found

    Sphere-shaped Mn3O4 catalyst with remarkable low-temperature activity for Methyl-Ethyl-Ketone combustion

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    Mn3O4, FeMnOx, and FeOx catalysts synthesized via a solvothermal method were employed for catalytic oxidation of methyl−ethyl−ketone (MEK) at low temperature. Mn3O4 with sphere-like morphology exhibited the highest activity for MEK oxidation, over which MEK was completely oxidized to CO2 at 200 °C, and this result can be comparable to typical noble metal loaded catalysts. The activation energy of MEK over Mn3O4 (30.8 kJ/mol) was much lower than that of FeMnOx (41.5 kJ/mol) and FeOx (47.8 kJ/mol). The dominant planes, surface manganese species ratio, surface-absorbed oxygen, and redox capability played important roles in the catalytic activities of catalysts, while no significant correlation was found between specific surface area and MEK removal efficiency. Mn3O4 showed the highest activity, accounting for abundant oxygen vacancies, low content of surface Mn4+ and strong reducibility. The oxidation of MEK to CO2 via an intermediate of diacetyl is a reaction pathway on Mn3O4 catalyst. Due to high efficiency and low cost, sphere-shaped Mn3O4 is a promising catalyst for VOCs abatement

    Insight into the efficient oxidation of methyl-ethyl-ketone over hierarchically micro-mesostructured Pt/K-(Al)SiO 2 nanorod catalysts: Structure-activity relationships and mechanism

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    Hierarchically micro-mesostructured Pt/K-Al-SiO2 catalysts with regular nanorod (Pt/KA-NRS) and spherical nanoflower-like (Pt/KA-SNFS) morphologies were prepared. The existence of Al atoms generates Brønsted acid sites and reduces silanol groups over the supports, promoting the dispersion of Pt nanoparticles and stability of catalysts. Potassium atoms balance the negative charge of supports and enhance O2 mobility. The Pt/KA-NRS catalysts exhibit unexceptionable low temperature activity, CO2 selectivity, and stability for MEK oxidation. Amongst, 0.27 wt.% Pt/KA-NRS completely converts MEK at just 170 °C (activation energy as low as 37.22 kJ·mol−1), more than 100 °C lower than other typical Pt/Pd supported catalysts reported in the literature. Diacetyl and 2,3-butandiol are the main intermediates during MEK activation, which convert into H2O and CO2 through aldehydes and acids. The excellent catalytic activity of Pt/KA-NRS is ascribed to their regular morphology, high Pt0 content and dispersion, excellent MEK adsorption capacity and superior O2/CO2 desorption capability under low temperature

    Inhibition of Protein Phosphatase 2A Sensitizes Mucoepidermoid Carcinoma to Chemotherapy via the PI3K-AKT Pathway in Response to Insulin Stimulus

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    Background/Aims: Protein phosphatase 2A (PP2A) is a ubiquitous serine/threonine phosphatase that mediates cell cycle regulation and metabolism. Mounting evidence has indicated that PP2A inhibition exhibits considerable anticancer potency in multiple types of human cancers. However, the efficacy of PP2A inhibition remains unexplored in mucoepidermoid carcinoma (MEC), especially in locally advanced and metastatic cases with limited systemic treatment. In this study, we demonstrated the therapeutic potency of LB100 in mucoepidermoid carcinoma. Methods: In this study, the expression of PP2A was evaluated using immunohistochemical (IHC) staining. The effects associated with LB100 alone and in combination with cisplatin for the treatment of mucoepidermoid carcinoma were investigated both in vitro, regarding metabolism, proliferation, and migration, and in vivo in a mucoepidermoid carcinoma xenograft model. In addition, with LB100 treatment and in response to an insulin stimulus, the expression levels and phosphorylation levels of targets in the PI3K-AKT pathway were determined using western blot analysis and immunoblotting. Results: The expression of protein phosphatase 2A was significantly upregulated in the clinical specimens of high-grade MECs compared with those of low-/medium-grade MECs and normal controls. In this article, we report that a small molecule PP2A inhibitor, LB100, decreased cellular viability and glycolytic activity and induced G2/M cell cycle arrest. Importantly, LB100 enhanced the efficacy of cisplatin in mucoepidermoid carcinoma cells both in vitro and in vivo. PP2A inhibition by LB100 increased the phosphorylation of insulin receptor substrate 1(IRS-1) on serine residues, downregulated the expression of phosphatidylinositol 3-kinase (PI3K) p110 alpha subunit and dephosphorylated AKT at Ser473 and Thr308 in mucoepidermoid carcinoma cells in response to insulin stimulus. Conclusion: These results highlight the translational potential of PP2A inhibition to synergize with cisplatin in mucoepidermoid carcinoma treatment

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    HBsAg seroprevalence in students for college entrance examination from 2006 to 2014 in Qidong of Jiangsu Province

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    ObjectiveTo investigate the HBsAg seroprevalence in the young generation in Qidong of Jiangsu Province, China. MethodsA total of 15 534 students for college entrance examination from 2006 to 2014 were randomly selected from three secondary schools in Qidong as student group. Some of them had hepatitis B vaccination at birth. A total of 1208 adults who had their routine checkups in our hospital from 2007 to 2013 were selected as adult group. It was confirmed that all of them did not have hepatitis B vaccination at birth. Serum HBsAg levels of the two groups were measured using enzyme-linked immunosorbent assay and the seroprevalence was analyzed. Comparison of data between the two groups was made by chi-square test. Results In the 9 years from 2007 to 2013, the seroprevalence rates of HBsAg in the student group were 4.2%(75/1794), 4.3%(77/1797), 4.4%(82/1858), 4.3%(82/1903), 3.4%(56/1627), 2.6%(46/1768), 1.6%(29/1778), 1.6%(27/1642), and 1.8%(24/1367), respectively. The mean HBsAg seroprevalence of the student group was 3.2%(498/15534), significantly lower compared with 7.1% (86/1208) of the adult group (χ2= 59.986, P<0.001). In both of the student group and the adult group, the males had a significantly higher HBsAg seroprevalence than the females (χ2=10.521, P=0.001; χ2=8.452, P=0.004) and the values were 3.7%(266/7236) vs 2.8%(229/8298) and 8.8%(66/750) vs 4.4%(20/458), respectively. Among male subjects, the HBsAg seroprevalence of the adult group was 2.4 times that of the student group; among female subjects, the HBsAg seroprevalence of the adult group was 1.6 times that of the student group. ConclusionIn the recent 9 years from 2006 to 2014, the HBsAg seroprevalence in students for college entrance examination declined continuously. The goal set by the World Health Organization Western Pacific Region in 2010 had been achieved ahead of the schedule that the HBsAg seroprevalence should be controlled below 2% in children aged less than 5
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