407 research outputs found

    Immunomodulatory Potential of Patchouli Alcohol Isolated from Pogostemon cablin (Blanco) Benth (Lamiaceae) in Mice

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    Purpose: To isolate and purify patchouli alcohol (PA), a tricyclic sesquiterpene constituent of Pogostemon cablin, and investigate its immunomodulatory potential in Kunming mice.Methods: PA was prepared from an ethanol aqueous extract of P. cablin by silica gel column chromatography, and further purified by crystallization using n-hexane. Purity was assessed by analytical gas chromatography (GC) and confirmation of chemical structure performed by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The effect of PA from Pogostemon cablin on immunological function was studied by macrophage phagocytosis, immune organ index, serum immunoglobulin level and delayed type  hypersensitivity (DTH) in mice that were administered orally doses of 20, 40 and 80 mg/kg.Results: The purity of PA was 99.3%. The oral administration of PA (40, or 80 mg/kg body weight) significantly increased the phagocytic index (p < 0.05), compared with prednisone acetate (PR) group. Administration of PA (80 mg/kg) boosted the production of circulating serum IgM (0.081 ± 0.010) and IgG (1.296 ± 0.120), while IgM and IgG in PR group was 0.069 ± 0.011 (p < 0.01) and 1.180 ± 0.070 (p < 0.01) respectively. However, PA (20 mg/kg) treatment elicited significant decrease in DTH induced by 2, 4-dinitro-chlorobenzene (DNCB) in mice (1.03 ± 0.40, p < 0.05), in comparison to DNCB-induced group (1.67 ± 0.84 mg).Conclusion: These results suggest that PA has significant immunomodulatory properties which probably act by activating mononuclear phagocytic system, augmenting humoral immune response while suppressing cellular immune response.Keywords: Patchouli alcohol, Pogostemon cablin, Immunomodulatory, Phagocytic index, Macrophag

    IFN-gamma is associated with risk of Schistosoma japonicum infection in China.

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    Before the start of the schistosomiasis transmission season, 129 villagers resident on a Schistosoma japonicum-endemic island in Poyang Lake, Jiangxi Province, 64 of whom were stool-positive for S. japonicum eggs by the Kato method and 65 negative, were treated with praziquantel. Forty-five days later the 93 subjects who presented for follow-up were all stool-negative. Blood samples were collected from all 93 individuals. S. japonicum soluble worm antigen (SWAP) and soluble egg antigen (SEA) stimulated IL-4, IL-5 and IFN-gamma production in whole-blood cultures were measured by ELISA. All the subjects were interviewed nine times during the subsequent transmission season to estimate the intensity of their contact with potentially infective snail habitats, and the subjects were all re-screened for S. japonicum by the Kato method at the end of the transmission season. Fourteen subjects were found to be infected at that time. There was some indication that the risk of infection might be associated with gender (with females being at higher risk) and with the intensity of water contact, and there was evidence that levels of SEA-induced IFN-gamma production were associated with reduced risk of infection

    Atomically dispersed Ni in cadmium-zinc sulfide quantum dots for high-performance visible-light photocatalytic hydrogen production.

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    Catalysts with a single atom site allow highly tuning of the activity, stability, and reactivity of heterogeneous catalysts. Therefore, atomistic understanding of the pertinent mechanism is essential to simultaneously boost the intrinsic activity, site density, electron transport, and stability. Here, we report that atomically dispersed nickel (Ni) in zincblende cadmium-zinc sulfide quantum dots (ZCS QDs) delivers an efficient and durable photocatalytic performance for water splitting under sunlight. The finely tuned Ni atoms dispersed in ZCS QDs exhibit an ultrahigh photocatalytic H2 production activity of 18.87 mmol hour-1 g-1. It could be ascribed to the favorable surface engineering to achieve highly active sites of monovalent Ni(I) and the surface heterojunctions to reinforce the carrier separation owing to the suitable energy band structures, built-in electric field, and optimized surface H2 adsorption thermodynamics. This work demonstrates a synergistic regulation of the physicochemical properties of QDs for high-efficiency photocatalytic H2 production

    Unique walnut-shaped porous MnO<inf>2</inf>/C nanospheres with enhanced reaction kinetics for lithium storage with high capacity and superior rate capability

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    Unique walnut-shaped porous MnO2/carbon nanospheres via in situ carbonization of amorphous MnO2 nanospheres demonstrate enhanced reaction kinetics for lithium storage.This work is realized in the frame of a program for Changjiang Scholars and Innovative Research Team (IRT_15R52) of Chinese Ministry of Education. B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Life Membership at the Clare Hall, Cambridge and the financial support of the Department of Chemistry, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. T. Hasan acknowledges funding from the Royal Academy of Engineering (Graphlex) and an Impact Acceleration Award (GRASS). This work is also financially supported by the National Science Foundation for Young Scholars of China (No. 21301133 and 51302204), International Science & Technology Cooperation Program of China (2015DFE52870) and and Self-determined and Innovative Research Funds of the SKLWUT (2015‐ZD‐7). The authors also would like to thank Dr. Bin-Jie Wang from Shanghai Nanoport (FEI, Shanghai) for TEM analysis, and thank Hang Ping from Wuhan University of Technology for the TGA/DSC tests.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C6TA00594

    Anchoring ultrafine metallic and oxidized Pt nanoclusters on yolk-shell TiO2 for unprecedentedly high photocatalytic hydrogen production

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    We demonstrate an alkali modification process to produce highly dispersed ultrafine Pt nanoclusters with metallic Pt0^0 and oxidized Pt2+^{2+} species as co-catalyst anchored on nanosheet-constructed yolk-shell TiO2_2 (NYTiO2_2-Pt) acting as light harvesting reactor for highly efficient photocatalytic H2_2 production. Benefiting from the high surface area, highly dispersed ultrafine Pt nanoclusters (~0.6 nm) with Pt0^0 and Pt2+^{2+} species and special nanosheet-constructed yolk-shell structure, this novel light harvesting reactor exhibits excellent performance for photocatalytic H2_2 production. The NYTiO2_2-Pt-0.5 (0.188 wt% Pt) demonstrates an unprecedentedly high H2_2 evolution rate of 20.88 mmol h1^{−1} g1^{−1} with excellent photocatalytic stability, which is 87 times than that of NYTiO2_2-Pt-3.0 (0.24 mmol h1^{−1} g1^{−1}, 1.88 wt% Pt), and also much higher than those of other TiO2_2 nanostructures with the same Pt content. Such H2_2 evolution rate is the highest reported for photocatalytic H2_2 production with such a low Pt content under simulated solar light. Our strategy here suggests that via alkali modifying the photocatalysts, we can not only enhance the H2_2 production for solar energy conversion but also significantly decrease the noble metal content for cost saving.B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Life Membership at the Clare Hall, Cambridge and the financial support of the Department of Chemistry, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. T. H. acknowledges support from the Royal Academy of Engineering through a Research Fellowship and an EPSRC Impact acceleration grant. This work is supported by the National Key Research and Development Program of China (2016YFA0202602), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52), International Science & Technology Cooperation Program of China (2015DFE52870), National Natural Science Foundation of China (51302204 and 51502225) and the Fundamental Research Funds for the Central Universities (WUT: 2016 029)

    Linear, Deterministic, and Order-Invariant Initialization Methods for the K-Means Clustering Algorithm

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    Over the past five decades, k-means has become the clustering algorithm of choice in many application domains primarily due to its simplicity, time/space efficiency, and invariance to the ordering of the data points. Unfortunately, the algorithm's sensitivity to the initial selection of the cluster centers remains to be its most serious drawback. Numerous initialization methods have been proposed to address this drawback. Many of these methods, however, have time complexity superlinear in the number of data points, which makes them impractical for large data sets. On the other hand, linear methods are often random and/or sensitive to the ordering of the data points. These methods are generally unreliable in that the quality of their results is unpredictable. Therefore, it is common practice to perform multiple runs of such methods and take the output of the run that produces the best results. Such a practice, however, greatly increases the computational requirements of the otherwise highly efficient k-means algorithm. In this chapter, we investigate the empirical performance of six linear, deterministic (non-random), and order-invariant k-means initialization methods on a large and diverse collection of data sets from the UCI Machine Learning Repository. The results demonstrate that two relatively unknown hierarchical initialization methods due to Su and Dy outperform the remaining four methods with respect to two objective effectiveness criteria. In addition, a recent method due to Erisoglu et al. performs surprisingly poorly.Comment: 21 pages, 2 figures, 5 tables, Partitional Clustering Algorithms (Springer, 2014). arXiv admin note: substantial text overlap with arXiv:1304.7465, arXiv:1209.196

    Role of Organic Cation Transporter 1, OCT1 in the Pharmacokinetics and Toxicity of cis-Diammine(pyridine)chloroplatinum(II) and Oxaliplatin in Mice

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    PurposeThe goal of this study was to test the hypothesis that by controlling intracellular uptake, organic cation transporter 1, Oct1 is a key determinant of the disposition and toxicity of cis-diammine(pyridine)chloroplatinum(II)(CDPCP) and oxaliplatin.MethodsPharmacokinetics, tissue accumulation and toxicity of CDPCP and oxaliplatin were compared between Oct1-/- and wild-type mice.ResultsAfter intravenous administration, hepatic and intestinal accumulation of CDPCP was 2.7-fold and 3.9-fold greater in Oct1 wild-type mice (p &lt; 0.001). Deletion of Oct1 resulted in a significantly decreased clearance (0.444 ± 0.0391 ml/min*kg versus 0.649 ± 0.0807 ml/min*kg in wild-type mice, p &lt; 0.05) and volume distribution (1.90 ± 0.161 L/kg versus 3.37 ± 0.196 L/kg in wild-type mice, p &lt; 0.001). Moreover, Oct1 deletion resulted in more severe off-target toxicities in CDPCP-treated mice. Histologic examination of the liver and measurements of liver function indicated that the level of hepatic toxicity was mild and reversible, but was more apparent in the wild-type mice. In contrast, the effect of Oct1 on the pharmacokinetics and toxicity of oxaliplatin in the mice was minimal.ConclusionsOur study suggests that Oct1 plays an important role in the pharmacokinetics, tissue distribution and toxicity of CDPCP, but not oxaliplatin

    Measurement of CP-violation asymmetries in D0 to Ks pi+ pi-

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    We report a measurement of time-integrated CP-violation asymmetries in the resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57 (stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry, consistent with the standard model prediction.Comment: 15 page

    Coordinate up-regulation of TMEM97 and cholesterol biosynthesis genes in normal ovarian surface epithelial cells treated with progesterone: implications for pathogenesis of ovarian cancer

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    <p>Abstract</p> <p>Background</p> <p>Ovarian cancer (OvCa) most often derives from ovarian surface epithelial (OSE) cells. Several lines of evidence strongly suggest that increased exposure to progesterone (P4) protects women against developing OvCa. However, the underlying mechanisms of this protection are incompletely understood.</p> <p>Methods</p> <p>To determine downstream gene targets of P4, we established short term <it>in vitro </it>cultures of non-neoplastic OSE cells from six subjects, exposed the cells to P4 (10<sup>-6 </sup>M) for five days and performed transcriptional profiling with oligonucleotide microarrays containing over 22,000 transcripts.</p> <p>Results</p> <p>We identified concordant but modest gene expression changes in cholesterol/lipid homeostasis genes in three of six samples (responders), whereas the other three samples (non-responders) showed no expressional response to P4. The most up-regulated gene was <it>TMEM97 </it>which encodes a transmembrane protein of unknown function (MAC30). Analyses of outlier transcripts, whose expression levels changed most significantly upon P4 exposure, uncovered coordinate up-regulation of 14 cholesterol biosynthesis enzymes, insulin-induced gene 1, low density lipoprotein receptor, <it>ABCG1</it>, endothelial lipase, stearoyl- CoA and fatty acid desaturases, long-chain fatty-acyl elongase, and down-regulation of steroidogenic acute regulatory protein and <it>ABCC6</it>. Highly correlated tissue-specific expression patterns of <it>TMEM97 </it>and the cholesterol biosynthesis genes were confirmed by analysis of the GNF Atlas 2 universal gene expression database. Real-time quantitative RT-PCR analyses revealed 2.4-fold suppression of the <it>TMEM97 </it>gene expression in short-term cultures of OvCa relative to the normal OSE cells.</p> <p>Conclusion</p> <p>These findings suggest that a co-regulated transcript network of cholesterol/lipid homeostasis genes and <it>TMEM97 </it>are downstream targets of P4 in normal OSE cells and that <it>TMEM97 </it>plays a role in cholesterol and lipid metabolism. The P4-induced alterations in cholesterol and lipid metabolism in OSE cells might play a role in conferring protection against OvCa.</p
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