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A projective ternary phase diagram of stationary non-equilibrium states for low-pressure diamond growth

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Chinese Science Bulletin 1997年第11期42卷 967-968页

作者： w.ng, JT Huang, ZQ wan, YZ Zhang, w Yang, qh Department of Electronic Engineering Fudan University Shanghai China Department of Applied Mathematics Tongji University Shanghai China

SINCE 1980,activated low-pressure diamond growth by chemical vapor deposition(CVD)pro-cess has been one of the worldwide interesting ***,in the last decades severalthermodynamic explanations were *** et *** a lot ofpu... 详细信息

关键词： A projective ternary phase diagram of stationary non-equilibrium states for low-pressure diamond growth

Biochemical mechanisms in drug-induced liver injury:Certainties and doubts

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world Journal of Gastroenterology 2009年第39期15卷 4865-4876页

作者： Ignazio Grattagliano Leonilde Bonfrate Catia V Diogo Helen H w.ng david qh w.ng Piero Portincasa Clinica Medica "A.Murri" Dipartimento di Medicina Interna e Medicina PubblicaUniversity of Bari Medical School Department of Zoology Center for Neurosciences and Cell BiologyUniversity of Coimbra Department of Medicine Liver Center and Gastroenterology DivisionBeth Israel Deaconess Medical CenterHarvard Medical School and Harvard Digestive Diseases Center

Drug-induced liver injury is a significant and still unresolved clinical problem. Limitations to knowledge about the mechanisms of toxicity render incomplete the detection of hepatotoxic potential during preclinical development. Several xenobiotics are lipophilic substances and their transformation into hydrophilic compounds by the cytochrome P-450 system results in production of toxic metabolites. Aging, preexisting liver disease, enzyme induction or inhibition, genetic variances, local 02 supply and, above all, the intrinsic molecular properties of the drug may affect this process. Necrotic death follows antioxidant consumption and oxidation of intracellular proteins, which determine increased permeability of mitochondrial membranes, loss of potential, decreased ATP synthesis, inhibition of Ca^2＋-dependent ATPase, reduced capability to sequester Ca^2＋ within mitochondria, and membrane bleb formation. Conversely, activation of nucleases and energetic participation of mitochondria are the main intracellular mechanisms that lead to apoptosis. Non-parenchymal hepatic cells are inducers of hepatocellular injury and targets for damage. Activation of the immune system promotes idiosyncratic reactions that result in hepatic necrosis or cholestasis, in which different HLA genotypes might play a major role. This review focuses on current knowledge of the mechanisms of drug-induced liver injury and recent advances on newly discovered mechanisms of liver damage. Future perspectives including new frontiers for research are discussed.

关键词： Adverse effects Apoptosis Drug toxicity Liver diseases Microsomes Mitochondria Necrosis

Crystal Structure of 5-(l-Menthyloxy)-3-Bromo-4-(R)-(+)-Methylbenzylamino-2(5H)-Furanone

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Chinese Journal of Structural Chemistry 1999年第2期18卷 32-34页

作者： Geng, Z Huang, B Chen, qh Capital Normal Univ Dept Chem Beijing 100037 Peoples R China Beijing Normal Univ Dept Chem Beijing 100875 Peoples R China

The crystal structure of the title compound 1, C 22 H 30 BrNO 3, was determined by X ray analysis at 296(1)K. The crystal belongs to othorhombic system, space group P2 12 12 1 with a=9.842(5), b=12.510(5), c=17.763(6) , V=2187(3)  3, Z=4, M r=436.37, D x =1.33 g/cm 3, μ =18.79 cm 1 , F(000) =912 and the final R=0.047 and R w=0.053 for 1429 observed reflections with I≥3σ(I). Structure analysis reveals that the absolute configuration at C 14 of the acetal carbon of the title compound is S.

关键词： crystal structure 2(5H) furanone absolute configuration.

Competition and the evolution of imperfect mimicry

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Current Zoology 2012年第4期58卷 608-619页

作者： david w. PFENNIG david w. KIKUCHI Department of Biology University of North Carolina Chapel Hill NC 27599-3280 USA

Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. we review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry .

关键词： Batesian mimicry Character displacement Hybridization MtUlerian mimicry Reproductive interference Selectivetrade-off

A Batesian mimic and its model share color production mechanisms

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Current Zoology 2012年第4期58卷 658-667页

作者： david w. KIKUCHI david w. PFENNIG Department of Biology University of North Carolina at Chapel Hill Chapel Hill NC 27599-3280 USA

Batesian mimics are harmless prey species that resemble dangerous ones （models）, and thus receive protection from predators. How such adaptive resemblances evolve is a classical problem in evolutionary biology. Mimicry is typically thought to be difficult to evolve, especially if the model and mimic produce the convergent phenotype through different proximate mecha- nisms. However, mimicry may evolve more readily if mimic and model share similar pathways for producing the convergent phenotype. In such cases, these pathways can be co-opted in ancestral mimic populations to produce high-fidelity mimicry with- out the need for major evolutionary innovations. Here, we show that a Batesian mimic, the scarlet kingsnake Larnpropeltis elap-soides, produces its coloration using the same physiological mechanisms as does its model, the eastern coral snake Micrurus fulvius. Therefore, precise color mimicry may have been able to evolve easily in this system. Generally, we know relatively little about the proximate mechanisms underlying mimicry .

关键词： Adaptation Coloration Convergent evolution Pteridine Pigment

Silybin counteracts lipid excess and oxidative stress in cultured steatotic hepatic cells

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world Journal of Gastroenterology 2016年第26期22卷 6016-6026页

作者： Giulia Vecchione Elena Grasselli Adriana Voci Francesca Baldini Ignazio Grattagliano david qh w.ng Piero Portincasa Laura Vergani DISTAV Department of Earth Environment and Life Sciences University of Genova Department of Biomedical Sciences and Human Oncology University School of Medicine Department of Internal Medicine Division of Gastroenterology and Hepatology Saint Louis University School of Medicine

AIM: To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic ***: Rat hepatoma FaO cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitate for 3 h to mimic liver steatosis. Then, the steatotic cells were incubated for 24 h with different concentrations (25 to 100 μmol/L) of silybin as phytosome complex with vitamin E. The effects of silybin on lipid accumulation and metabolism, and on indices of oxidative stress were evaluated by absorption and fluorescence microscopy, quantitative real-time PCR, western blot, spectrophotometric and fluorimetric ***: Lipid-loading resulted in intracellular triglyceride (TG) accumulation inside lipid droplets, whose number and size increased. TG accumulation was mediated by increased levels of peroxisome proliferator-activated receptors (PPARs) and sterol regulatory element-binding protein-1c (SREBP-1c). The lipid imbalance was associated with higher production of reactive oxygen species (ROS) resulting in increased lipid peroxidation, stimulation of catalase activity and activation of nuclear factor kappa-B (NF-κB). Incubation of steatotic cells with silybin 50 μmol/L significantly reduced TG accumulation likely by promoting lipid catabolism and by inhibiting lipogenic pathways, as suggested by the changes in carnitine palmitoyltransferase 1 (CPT-1), PPAR and SREBP-1c levels. The reduction in fat accumulation exerted by silybin in the steatotic cells was associated with the improvement of the oxidative imbalance caused by lipid excess as demonstrated by the reduction in ROS content, lipid peroxidation, catalase activity and NF-κB ***: we demonstrated the direct anti-steatotic and anti-oxidant effects of silybin in steatotic cells, thus elucidating at a cellular level the encouraging results demonstrated in clinical and animal studies.

关键词： Non-alcoholic fatty liver disease Steatotic hepatocytes Silybin Lipid metabolism Oxidative stress Lipid droplets Mitochondrial β -oxidation

Applications of Pattern Recognition in Drug Discovery

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Chemical Research in Chinese Universities 2002年第2期18卷 107-108页

作者： w. Graham Richards Department of Chemistry, University of Oxford, Central Chemistry, South Parks Road, Oxford OX1 3qh, UK Department of Chemistry University of Oxford Central Chemistry South Parks Road 英国 Oxford

This is a brief account of the plenary talk given to the meeting of the Chinese Society of Chemical Science and Technology held in Oxford on 6 October 2001. The talk covered the application of pattern recognition techniques to discover molecules which will bind to the binding sites of proteins. Three situations were considered: the structure of the protein being unknown; the structure known but the binding site unknown; and finally, and this is the most important case for the future, both the structure and nature of the target site available in atomic detail. For this case we have developed a massively distributed computer program using a screensaver which now involves over one million personal computers, including over a thousand in China. The project will involve the screening of 3 5 billion small molecules against 16 protein targets, all of which are implicated in the process of cancer.

关键词： Pattern recognition Drug Protein Gene Binding site

Recombinase-mediated Gene Stacking as a Transformation Operating System

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Journal of Integrative Plant Biology 2011年第7期53卷 512-519页

作者： david w.Ow South China Botanical Garden

The current method for combining transgenes into a genome is through the assortment of independent loci, a classical operating system compatible with transgenic traits created by different developers, at different times and/or through different transformation techniques. However, as the number of transgenic loci increases over time, increasingly larger populations are needed to find the rare individual with the desired assortment of transgenic loci along with the non-transgenic elite traits. Introducing a transgene directly into a field cultivar would bypass the need to introgress the engineered trait. However, this necessitates separate transformations into numerous field cultivars, along with the characterization and regulatory approval of each independent transformation event. Reducing the number of segregating transgenic loci could be achieved if multiple traits are introduced at the same time, a preferred option if each of the many traits is new or requires re-engineering. If reengineering of previously introduced traits is not needed, then appending a new trait to an existing locus would be a rational strategy. The insertion of new DNA at a known locus can be accomplished by site- specific integration, through a host-dependent homology-based process, or a heterologous site-specific recombination system. Here, we discuss gene stacking through the use of site-specific recombinases.

关键词： site-specific recombination transgenic plants DNA integration marker removal Cre-lox

A Review of the Taxonomy and Palaeoecology of the Anurognathidae(Reptilia,Pterosauria)

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Acta Geologica Sinica(English Edition) 2020年第5期94卷 1676-1692页

作者： david w.E.HONE School of Biological and Chemical Sciences Queen Mary University of LondonLondonE14NSUK

The anurognathids are an enigmatic and distinctive clade of small,non-pterodactyloid pterosaurs with an unusual combination of anatomical traits in the head,neck,w.ngs and *** are known from very limited remains and few have been described in detail,and as a result,much of their biology remains *** is despite their importance as potentially one of the earliest branches of pterosaur evolution or even lying close to the origins of *** review covers the taxonomy and palaeoecology of the anurognathids,which remain an interesting branch of pterosaurian evolution.

关键词： non-pterodactyloid palaeobiology flight Ornithodira