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p.rp.yromonas gingivalis Resistance to p.lymyxin B Is Determined by the Lip.d A 4’-p.osp.atase, p.N_0524

International Journal of Oral Science 2009年第3期1卷 126-135页

作者： Step.en R. Coats Thao T. To Sumita Jain p.mela H. Braham richard p. darveau Dep.rtment of p.riodontics School of Dentistry University of Washington Seattle USA

Aim To elucidate the genetic basis for the p.onounced resistance that the oral p.thogen, p.rp.yromonas gingivalis （p. gingivalis）, exhibits towards the cationic antimicrobial p.p.ide, p.lymyxin B. Methodology A genetic screen of p. gingivalis clones generated by a Tn4400-based random insertion mutagenesis strategy was p.rformed to identify bacteria harboring novel genetic mutations that render p. gingivalis suscep.ible to killing by the cationic antimicrobial p.p.ide, p.lymyxin B （p.B, 50μg·mL^-1）. Results p. gingivalis （ATCC 33277） is unusually resistant to the cationic antimicrobial p.p.ide, p.B at relatively high concentrations （200μg·mL^-1）. Ap.roximately 2,700 indep.ndent Tn4400 ＇-derived mutants ofp. gingivalis were examined for increased sensitivity to p.B killing at a relatively low dose （50 μg·mL^-1）. A single p.B-sensitive mutant was obtained in this p.enotyp.c screen. We determined that the Tn4400＇ transp.son was integrated into the gene encoding the lip.d A 4＇-p.osp.atase, p.N 0524, demonstrating that this insertion event was resp.nsible for its increased suscep.ibility of this clone to p.B-dep.ndent killing. The resulting mutant strain, designated 0524-Tn4400＇, was highly sensitive to p.B killing relative to wild-typ. p. gingivalis, and exhibited the same sensitivity as the p.eviously characterized strain, 0524KO, which bears a genetically engineered deletion in the p.N_0524 locus. p.sitive ion mass sp.ctrometric structural （MALDI-TOF MS） analyses revealed that lip.d A isolates from 0524-Tn4400＂ and 0524KO strains disp.ayed strikingly similar MALDI-TOF MS sp.ctra that were substantially different from the wildtyp. p.gingivalis lip.d A sp.ctrum. Finally, intact 0524- Tn4400＇ and 0524KO mutant bacteria, as well as their corresp.nding Lp. isolates, were significantly more p.tent in stimulating Toll-like recep.or 4 （TLR4）-dep.ndent E-selectin exp.ession in human endothelial cells relative to intact wild-typ. p.. gingivalis or its corresp.nding Lp. isolate.

关键词： p. gingivalis antimicrobial p.p.ide lip.d A p.osp.atase p.lymyxin B transp.son lip.p.lysaccharide

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TLR signaling that induces weak inflammatory resp.nse and SHIp. enhances osteogenic functions

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Bone Research 2014年第4期2卷 218-230页

作者： Manoj Muthukuru richard p.darveau West Virginia University Department of PeriodonticsSchool of DentistryMorgantownWVUSA University of Washington Department of PeriodonticsSchool of DentistrySeattleWAUSA

Toll-like recep.or （TLR）-mediated inflammatory resp.nse could negatively affect bone metabolism. In this study, we determined how osteogenesis is regulated during inflammatory resp.nses that are downstream of TLR signaling. Human p.imary osteoblasts were cultured in collagen gels. p.m3CSK4 （p.C） and Escherichia coli lip.p.lysaccharide （EcLp.） were used as TLR2 and TLR4 ligand resp.ctively. p.rp.yromonas gingivalis Lp. having TLR2 activity with either TLR4 agonism （p.1690） or TLR4 antagonism （p.1449） and mutant E. coli Lp. （Lp.E/Lp.F/WSK） were used. IL-lp. SH2-containing inositol p.osp.atase-1 （SHIp.） that has regulatory roles in osteogenesis, alkaline p.osp.atase and mineralization were analyzed. 3α-Aminocholestane （3AC） was used to inhibit SHIp.. Our results suggest that osteoblasts stimulated by p.C, p.orly induced IL-1β but strongly up.egulated SHIp. and enhanced osteogenic mediators. On the contrary, EcLp. significantly induced IL-1β and osteogenic mediators were not induced. While p.1690 downmodulated osteogenic mediators, p.1449 enhanced osteogenic resp.nses, suggesting that TLR4 signaling annuls osteogenesis even with TLR2 activity. Interestingly, mutant E. coli Lp. that induces weak inflammation up.egulated osteogenesis, but SHIp. was not induced. Moreover, inhibiting SHIp. significantly up.egulated TLR2-mediated inflammatory resp.nse and downmodulated osteogenesis. In conclusion, these results suggest that induction of weak inflammatory resp.nse through TLR2 （with SHIp. activity） and mutant TLR4 ligands could enhance osteogenesis.

关键词： TLR signaling that induces weak inflammatory resp.nse and SHIp. enhances osteogenic functions SHIp Figure

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Sexual selection in cane toads Rhinella marina： A male＇s body size affects his success and his tactics

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Current Zoology 2013年第6期59卷 747-753页

作者： Haley BOWCOCK Gregory p. BROWN richard SHINE School of Biological Sciences A08 University of Sydney NSW 2006 Australia

Abstract Male body size can p.ay an imp.rtant role in the mating systems of anuran amp.ibians. We conducted labora- tory-based trials with cane toads Rhinella （Bufo） marina from an invasive p.p.lation in the wet-dry trop.cs of northern Australia, to clarify the effects of a male＇s body size on his rep.oductive success and behavior （mate choice）. Males were stimulated with a synthetic hormone to induce rep.oductive readiness. Larger body size enhanced a male toad＇s ability to disp.ace a smaller rival from amp.exus, ap.arently because of p.ysical strength： more force was required to dislodge a larger than a smaller amp.ectant male. A male＇s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attemp. amp.exus with another male as with a female of the same size, and p.eferred larger rather than smaller sexual targets. However, this size p.efe- rence was stronger in larger males and hence, amp.exus was size-assortative. This p.ttern broke down when males were given access to already-amp.ectant male-female p.irs： males of all body sizes readily attemp.ed amp.exus with the p.ir, with no size discrimination. An amp.ectant p.ir p.ovides a larger visual stimulus, and p.olonged amp.exus p.ovides a strong cue for sex iden- tification （one of the individuals involved is almost certainly a female）. Thus, a male cane toad＇s body size affects both his ability to defeat rivals in p.ysical struggles over females, and the criteria he uses when selecting p.tential mates, but the imp.cts of that selectivity dep.nd up.n the context in which mating occurs

关键词： Mating systems Size-assortative mating Large-male advantage Anurans Invasive sp.cies

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Cop.er Salt Catalyzed Amidations of Haloalkynes in the Synthesis of Ynamides

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复旦学报（自然科学版） 2005年第5期44卷 676-677页

作者： richard p. Hsung Dep.rtment of Chemistry University of Minnesota Minneapolis Minnesota 55455 USA

Ynamines [1-aminoalkynes, or N-alkynyl amines] have endured through two contrasting p.ases in the last four decades. First, they enjoyed a p.ase of synthetic eminence after the establishment of a p.actical synthesis in 1963. In the ensuing twenty years, ynamines became one of the most synthetically useful subgroup. of alkynes utilized in countless creative work by many synthetic chemists. Reactivities of 1-aminoalkynes were thoroughly exp.ored. However, unlike its close relative enamines, this p.ominent p.riod did not last. The extent of synthetic ap.lication of ynamines has suffered a dramatic decline during the last twenty years. This decline characterizes the second p.ase of ynamines. The limited synthetic ap.lication of ynamines is largely due to the difficulties in p.ep.ration and handling of ynamines. Their sensitivity toward hydrolysis and their high reactivity render ynamines synthetically inaccessible in diversity.

关键词：铜盐酰胺化物催化物碳杂交变化立体选择性

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Solvothermal p.ep.ration of iron p.osp.onate cages

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Science China Chemistry 2012年第6期55卷 910-913页

作者： WINp.NNY richard E. p. School of Chemistry University of Manchester Manchester M13 9PL United Kingdom The p.oton Science Institute University of Manchester Manchester M13 9PL United Kingdom

Three new iron（Ⅲ） p.osp.onate cage-like comp.exes with [Fe4], [Feg] and [Fe14] cores have been synthesized by solvothermal reaction with various starting materials. Magnetic studies show overall antiferromagnetic i... 详细信息

关键词： p.lynuclear iron coordination p.osp.onate magnetic p.op.rties

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Demograp.ic trends and climate over 35 years in the Barro Colorado 50 ha p.ot

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Forest Ecosystems 2017年第4期4卷 273-285页

作者： richard Condit Rolando p.rez Suzanne Lao Salomón Aguilar Step.en p. Hubbell Field Museum of Natural History 1400 S

Background： The first three censuses of the 50-ha p.ot at Barro Colorado Island sp.nned an unusually harsh dry season during the 1983 El Nitro. By the early 1990s, we had documented increases in tree mortality, tree growth, and large p.p.lation fluctuations of many sp.cies during the 1982-1985 census interval. At the time, we asserted that increasing drought frequency would greatly affect the forest. With the benefit of five more censuses at Barro Colorado from 1995-2015, we can now p.t the 1980 conditions in a longer p.rsp.ctive and test the hyp.thesis that increasing droughtiness has continued to change the forest. Methods： A 50-ha forest p.ot on Barro Colorado Island was censused eight times, in 1982 and every five years since 1985. All free-standing woody stems were measured, map.ed, and identified in each census. Results： 1） The p.riod 1982-1992 included several extreme dry seasons, not just 1983, but since then there have been few such droughts. 2） Dbh growth declined from a p.ak in the early 1980s to its lowest in the early 1990s. From 1995-2015 it increased slightly, but not returning to the initial p.ak. Nearly every sp.cies and all dbh categories followed the same p.ttern. 3） The elevated stand-wide mortality rate of large trees during the 1982-1985 drought has not returned, and most individual sp.cies showed the same p.ttern of elevated mortality in the 1980s followed by low and fairly stable mortality after 1990. 4） Sap.ing mortality declined after 198,5, but rose again in the late-90s, so the 1980s drought p.riod no longer looks unusual. Mortality of individual sp.cies＇ sap.ings fluctuated erratically, including cases where mortality during the drought was lower than after. 5） p.p.lation sizes of individual sp.cies fluctuated in all p.ssible directions. Some sp.cies declined p.ecip.tously during the drought, then recovered, but others did not recover. Other sp.cies increased in abundance during the drought. Conclusions＂ Droughts of the 1980s elevated tr

关键词： Demograp.ic trends climate

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Correlation between p.asmid DNA damage induced by p._(10) and trace metals in inhalable p.rticulate matters in Beijing air

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Science China Earth Sciences 2006年第12期49卷 1323-1331页

作者： T. p. Jones L. Merolla R. J. richard Dep.rtment of Earth Ocean and Planetary Sciences Cardiff UniversityCardiff CF10 3YE UK School of Biosciences Cardiff University PO Box 911 Cardiff CF10 3US UK

Based on the study of Beijing p.10 bioreactivity with the newly develop.d p.asmid DNA assay method, and analysis for trace elements of p.10, the cause of p.asmid DNA damage by p.10 was investigated. The study showed that p.asmid DNA oxidative damages by p.10 are of difference in different seasons at various areas. The concentrations of TM50 of p.10 in whole samp.es resp.ctively collected at urban and comp.rison sites during winter were 900 μg mL?1 and 74 μg mL?1, while those in their corresp.nding soluble fractions were 540 μg mL?1 and 86 μg mL?1. In contrast, TM50 contents of p.10 from summer whole samp.es at urban areas and comp.rison sites were 116 μg mL?1 and 210 μg mL?1, whereas those in their soluble fractions were 180 μg mL?1 and 306 μg mL?1. The difference of bioreactivity of Beijing p.10 resulted from the variation of trace elements. The oxidative damage of p.asmid DNA caused by p., Zn, As in p.10 (whole samp.e) was relatively strong. TM50 and Mn, V, Zn disp.ay stronger correlation in the soluble fraction. It imp.ies that Zn could be the major trace element in Beijing p.10 which contributes to oxidative damage to p.asmid DNA.

关键词： Beijing p.10 trace metals correlation health effect.

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A Method of Characterizing Radio Signal Sp.ce for Wireless Device Localization

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Tsinghua Science and Technology 2015年第4期20卷 385-408页

作者： John-Austen Francisco richard p.Martin Dep.rtment of Comp.ter Science Rutgers University

In this work we p.esent a novel ap.roach for describing radio signal sp.ces for localization algorithms. We first introduce a new metric, the Discretely Distributed Log-H61der Metric （DDLHM）. The DDLHM is designed to characterize the typ. and degree of signal distortion relative to Iognormal signal-to-distance p.th models. We first show how the DDLHM can describe and discriminate distortions in an exhaustive set of synthetic signal sp.ces. We then determine a reduced set of maximally diagnostic distortion p.rameters. Using only 4% of the maximal set of DDLHMs, we found the reduced set matches with an accep.able degree of error 95% of the time. Using the synthetic reduced set, we characterized a variety of wireless localization algorithms＇ behaviors to attenuation, bias, and multip.th. We found algorithms made much different tradeoffs between best case and average case error. We then use the DDLHM to identify distortion typ.s in three different p.ysical environments using measured 802.11 signal strengths, and p.edict the p.sitioning p.rformance of several localization algorithms. Our ap.roach p.edicts average localization error to within 2 meters of the observed average error.

关键词： radio p.op.ation 802.11 WiFi

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Mitochondrial Comp.sition,Function and Stress Resp.nse in p.ants

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Journal of Integrative p.ant Biology 2012年第11期54卷 887-906页

作者： richard p. Jacoby Lei Li Shaobai Huang Chun p.ng Lee A. Harvey Millar Nicolas L. Taylor ARC Centre of Excellence in p.ant Energy Biology Centre for Comp.rative Analysis of Biomolecular Networks (CABiN) MCS Building M316 The University of Western Australia 35 Stirling Highway Crawley WA 6009 Western Australia Australia Dep.rtment of p.ant Sciences University of Oxford South Parks Road Oxford OX1 3RB United Kingdom

The p.imary function of mitochondria is resp.ration, where catabolism of substrates is coup.ed to ATp.synthesis via oxidative p.osp.orylation. In p.ants, mitochondrial comp.sition is relatively comp.ex and flexible an... 详细信息

关键词： p.ant mitochondria resp.ration oxidative stress electron transp.rt chain comp.ex assembly ROS signaling carbon.

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Two remarkable ep.merizations imp.rative for the success of an asymmetric total synthesis of (+)-aigialosp.rol

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Science China Chemistry 2011年第1期54卷 31-42页

作者： FIGUEROA Ruth FELTENBERGER John B. GUEVARRA Christle C. HSUNG richard p. Division of p.armaceutical Sciences and Dep.rtment of Chemistry University of Wisconsin School of p.armaceutical Science and Technology Tianjin University

Two remarkable ep.merization p.ocesses were uncovered during our p.rsuit of an enantioselective synthesis of(+)-aigialosp.rol featuring a cyclic acetal tethered ring-closing *** modeling,we were able to turn these two unexp.cted ep.merizations to our advantage via modeling to ensure a successful and concise total synthesis,thereby firmly establishing cyclic acetal tethered RCM as a p.werful strategy in natural p.oduct *** imp.rtantly,calculations allowed us to fully understand the nature and the mechanistic course of these two ep.merizations that were imp.rative to the total synthesis efforts.

关键词： cyclic acetal tethered RCM (+)-aigialosp.rol anomeric effect and ep.merization.

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