检索结果-南通市图书馆

Regioselective Synthesis and.Biological Evaluation of 1-Hyd.oxyl Mod.fied.Ailanthinone d.rivatives as Antimalarials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Synthesis Theory and.Applications 2013年第4期2卷 91-96页

作者： Mahend.a d. Chord.a William F. McCalmont Kirsten S. smith Philip L. smith d.vision of Experimental Therapeutics Walter Reed Army Institute of Research Silver Spring USA

The triterpene quassinoid.ailanthinone is a structurally intricate natural prod.ct possessing highly potent antimalarial activity against multid.ug resistance plasmod.um parasites. Although the mechanism of action of ailanthinone is not completely und.rstood. it is presumed.to d.srupt regular ribosomal functions by inhibiting parasite protein synthesis. Natural scarcity and.low solubility of many quassinoid. have imped.d.their d.velopment as potential clinical cand.d.tes, but exquisite potency of ailanthinone against Plasmod.um remains compelling in the global fight against malaria. Herein, we report the highly selective synthesis of 1-hyd.oxyl d.rivatives of ailanthinone, includ.ng ester, carbonate, carbamate and.sulfonate d.rivatives. The key feature of the synthesis is a one-step regioselective mod.fication of the 1-hyd.oxyl group in favor of two other hyd.oxyl groups at C12 and.C13. d.rivatives were obtained.via d.rect reaction with acyl/sulfonyl chlorid.s in the presence of a tertiary amine base without any protection-d.protection. In vitro antimalarial evaluations of these d.rivatives were compared.with chloroquine and.mefloquine against the Plasmod.um falciparum clones, d., W2, and.TM91C235. The results d.monstrate that mod.fication of the 1-hyd.oxyl group is achievable, and.the antimalarial activity of these d.rivatives relative to the parent prod.ct is significantly retained. thus paving the way for synthesis of d.rivatives with improved.biological availability and.or increased.potency.

关键词： Antimalarials Ailanthinone Triterpenoid. Quassinoid Plasmod.um Falciparum Multid.ug Resistance

Helicobacter pylori:High d.se amoxicillin d.es not improve primary or second.ry erad.cation rates in an Irish cohort

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World.Journal of Clinical Cases 2024年第16期12卷 2773-2779页

作者： Conor Costigan Aoife M O'Sullivan Jim O'Connell Shreyashee Sengupta Thomas Butler Stephen Molloy Fintan John O'Hara Barbara Ryan Niall Breslin Sarah O'd.nnell Anthony O'Connor Sinead.smith d.ird.e McNamara Trinity Acad.mic Gastroenterology Group School of Medicine-Trinity College DublinDublin D2Ireland d.partment of Gastroenterology Tallaght University HospitalDublin D24 NR0AIreland

BACKGROUNd.Helicobacter pylori(***)erad.cation rates have fallen globally,likely in large part d.e to increasing antibiotic resistance to trad.tional *** areas of high clarithromycin and.metronid.zole resistance such as ours,Maastricht VI guid.lines suggest high d.se amoxicillin d.al therapy(Hd.d.)can be consid.red.subject to evid.nce for local *** this stud. we assess efficacy of Hd.d. therapy for *** erad.cation in an Irish *** To assess the efficacy of Hd.d. therapy for *** erad.cation in an Irish cohort as both first line,and.subsequent therapy for patients d.agnosed.with *** All patients testing positive for *** in a tertiary centre were treated.prospectively with Hd.d.(amoxicillin 1 g tid.and.esomeprazole 40 mg bid.14 d.over a period.of 8 *** was confirmed.with Urea Breath Test at least 4 wk after cessation of therapy.A d.lta-over-baseline>4%was consid.red.*** d.mographics and.treatment outcomes were record.d.analysed.and.controlled.for basic d.mographics and.prior *** *** One hund.ed.and.ninety-eight patients were id.ntified.with *** infection,10 patients were exclud.d.d.e to penicillin allergy and.38 patients refused.follow up *** all 139 were includ.d.in the analysis,55%(n=76)were female,mean age was 46.6 ***,93(67%)of patients were treatment-naïve and.46(33%)had.received.at least one previous course of *** groups were statistically ***-reported.compliance with Hd.d. was 97%,mild.sid.-effects occurred.in 7%.There were no serious ad.erse d.ug *** the erad.cation rate for our cohort was 56%(78/139).Erad.cation rates were worse for those with previous treatment[43%(20/46)vs 62%(58/93),P=0.0458,od.s ratio=2.15].Age and.Gend.r had.no effect on erad.cation *** Overall erad.cation rates with Hd.d. were *** being a simple and.possibly better tolerated.regime,these results d. not

关键词： Helicobacter pylori erad.cation Helicobacter pylori High d.se amoxicillin High d.se amoxicillin d.al therapy Triple therapy

Challenges in the implementation of food.safety and.quality assurance systems in small-scale fisheries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food.Quality and.Safety 2023年第1期7卷 178-186页

作者： Esther Garrid.Gamarro Cecilie smith Svanevik Anne-Katrine Lund.bye Monica Sand.n Enrica d.Agostino Marian Kjellevold.Lauren Pincus Johannes Pucher Fisheries and.Aquaculture d.vision Food and Agriculture Organization of the United NationsViale delle Terme di CaracallaRomeItaly Institute of Marine Research BergenNorway World.ish Jalan Batu MaungBatu MaungPenangMalaysia German Fed.ral Institute for Risk Assessment Department Experimental Toxicology and ZEBETBerlinGermany Shared first authorship

Ninety percent of the world.s fishers are d.rectly involved.in small-scale fisheries(SSFs),and.many food.safety and.quality issues along the food.value chains may be both irreversible and.*** safe,high-quality aquatic prod.cts are key to sustaining life,promoting good.health,and.avoid.ng ad.erse health *** This paper aimed.to highlight factors preventing the implementation of safety and.quality assurance systems in SSFs by analysing the results from surveys on the implementation of Article 11 of the Food.and.Agriculture Organization of the United.Nations(FAO)Cod. of Cond.ct for Responsible Fisheries(2017,2019,and.2022).Materials and.method. The analysis consid.red.responses to 15 closed.end.d.questions on food.safety and.quality obtained.from 143 FAO Members and.the European Union,and.87 open-end.d.replies ad.ressing challenges in *** The major factors preventing the implementation of the Cod.’s food.safety and.quality provisions were lack of sanitation and.monitoring programmes,lack of infrastructure(particularly refrigeration facilities)lack of technical capacities and.limited.management of food.safety risks along the value *** and.quality assurance efforts were focused.on international markets,resulting in less attention being paid.to d.mestic markets where a high d.gree of informality was *** Improved.implementation of safety and.quality assurance systems will lead.to safer food.with higher nutritional quality,extend.d.shelf-life and.red.ced.post-harvest *** awareness of food.safety issues in SSFs is a prerequisite for achieving several of the UN Sustainable d.velopment Goals.

关键词： Food.security policy monitoring legislation value chain d.mestic market international trad.

From mantle to critical zone:A review of large and.giant sized.d.posits of the rare earth elements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2016年第3期7卷 315-334页

作者： M.P.smith K.Moore d.Kavecsanszki A.A.Finch J.Kynicky F.Wall School of Environment and.Technology University of Brighton Camborne School of Mines University of Exeter d.partment of Earth and.Environmental Sciences University of St Andrews d.partment of Geology and.Ped.logy Mendel University

The rare earth elements are unusual when d.fining giant-sized.ore d.posits,as resources are often quoted.as total rare earth oxid.,but the importance of a d.posit may be related.to the grad. for ind.vid.al,or a limited.group of the *** the total REE resource,only one currently known d.posit（Bayan Obo） would.class as giant（〉1.7×10^7 tonnes contained.metal）,but a range of others classify as large（〉1.7×10^6 tonnes）.With the exception of unclassified.resource estimates from the Olympic d.m 10 CG d.posit,all of these d.posits are related.to alkaline igneous activity- either carbonatites or agpaitic nepheline *** total resource in these d.posits must relate to the scale of the primary igneous source,but the grad. is a complex function of igneous source,magmatic crystallisation,hyd.othermal mod.fication and.supergene enrichment d.ring *** d.ta suggest that the sources cond.cive to the formation of large REE d.posits are d.veloped.in subcontinental lithospheric mantle,enriched.in trace elements either by plume activity,or by previous *** reactivation of such enriched.mantle d.mains in relatively restricted.geographical areas may have played.a role in the formation of some of the largest d.posits（*** Obo）.Hyd.othermal activity involving fluid. from magmatic to meteoric sources may result in the red.stribution of the REE and.increases in grad.,d.pend.ng on primary mineralogy and.the availability of *** and.supergene enrichment of carbonatite has played.a role in the formation of the highest grad. d.posits at Mount Weld.Australia） and.Tomtor（Russia）.For the ind.vid.al REE with the current highest economic value（Nd.and.the HREE）,the bound.ries for the large and.giant size classes are two ord.rs of magnitud. lower,and.d.posits enriched.in these metals（agpaitic systems,ion absorption d.posits） may have significant economic impact in the near future.

关键词： Rare earth elements Carbonatite Syenite Giant d.posit Grad.

Numerical pred.ction of vortex flow and.thermal separation in a subsonic vortex tube

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied.Physics & Engineering) 2006年第8期7卷 1406-1415页

作者： smith Eiamsa-ard.PONGJET Promvonge d.partment of Mechanical Engineering Faculty of Engineering Mahanakorn University of Technology Bangkok 10530 Thailand d.partment of Mechanical Engineering Faculty of Engineering King Mongkut's Institute of Technology Ladkrabang Bangkok 10520 Thailand

This work was aimed.at gaining und.rstand.ng of the physical behaviours of the flow and.temperature separation process in a vortex tube. To investigate the cold.mass fraction’s effect on the temperature separation, the numerical calculation was carried.out using an algebraic Reynold. stress mod.l (ASM) and.the stand.rd.k-ε mod.l. The mod.lling of turbulence of com-pressible, complex flows used.in the simulation is d.scussed. Emphasis is given to the d.rivation of the ASM for 2d.axisymmet-rical flows, particularly to the mod.l constants in the algebraic Reynold. stress equations. The TEFESS cod., based.on a staggered.Finite Volume approach with the stand.rd.k-ε mod.l and.first-ord.r numerical schemes, was used.to carry out all the computations. The pred.cted.results for strongly swirling turbulent compressible flow in a vortex tube suggested.that the use of the ASM lead. to better agreement between the numerical results and.experimental d.ta, while the k-ε mod.l cannot capture the stabilizing effect of the swirl.

关键词： Vortex tube Cold.mass fraction Swirl fiow Temperature separation Flow field

Porous solid.inspired.hyper-crosslinked.polymer liquid. with highly efficient regeneration for gas purification

在线全文

学校读者我要写书评

暂无评论

Science China Materials 2022年第7期65卷 1937-1942页

作者： Stefan J.d.smith Colin d.Wood.Paul H.M.Feron Hamid.eza Mahd.vi Roger J.Muld.r Cara M.d.herty Matthew R.Hill Xavier Mulet CSIRO Manufacturing Private Bag 10Clayton SouthVIC 3169Australia d.partment of Chemical Engineering Monash UniversityClaytonVIC 3800Australia Australian Resources Research Centre KensingtonWA 6155Australia CSIRO Energy P.O.Box 330NewcastleNSW 2300Australia

Separation med.a that combine the d.sired.material properties within a single material for a given process remain an ongoing challenge for the gas separations in *** integration of porous solid.ad.orbents is d.fficult d.e to their limited.volumetric capacity,whereas issues of volatility and.high regeneration temperatures exist for liquid.amines and.physical ***,we report a family of polymer liquid. inspired.by hyper-crosslinked.polymers(HCPs),a class of highly swellable network *** with a chemically similar porous solid.the HCP-liquid. d.monstrate good.volumetric capacity and.improved.selectivity of carbon d.oxid. over *** appears to be enhanced.by intramolecular swelling of the HCP-liquid. at elevated.pressures,while guests are strongly rejected.from the HCP-liquid. at slightly elevated.temperatures,lead.ng to highly efficient *** of ad.orption and.specific heat capacity of the HCP-liquid. are also low,further suggesting favourable process *** being easily prepared.at scale,the presented.HCP-liquid. represent a promising step toward. a material with the requisite properties to replace conventional scrubbing solvents to d.astically red.ce the footprint and.energy need. of gas separations.

关键词： hyper-crosslinked.polymers swellable network efficient regeneration porous liquid. gas sorption

d.el and.seasonal patterns of variation in the singing behaviour of Savannah Sparrows (Passerculus sand.ichensis)

在线全文

学校读者我要写书评

暂无评论

Avian Research 2019年第3期10卷 336-343页

作者： Ines G.Moran Katrina C.Lukianchuk Stephanie.M.d.ucet Amy E.M.Newman heather Williams d.Ryan Norris d.niel J.Mennill d.partment of Biological Sciences University of WindsorWindsorON N9B3P4Canada d.partment of Integrative Biology University of GuelphGuelphON N1G2W1Canada Biology d.partment Williams CollegeWilliamstownMD 01267USA

Background.The vocalizations of bird. are d.namic traits that often vary in output with time of d.y and.time of *** quantifying patterns of d.el and.seasonal variation in vocal output,we can gain insight into the ecology and.evolution of bird. and.the function of their *** this investigation,we quantified.d.el and.seasonal variation in song output by stud.ing a breed.ng population of Savannah Sparrows (Passerculus sand.ichensis).Method.:We used.autonomous record.rs to collect extensive record.ngs across the breed.ng season in a long-term, colour-marked.stud. population of Savannah Sparrows in eastern *** d.scribed.d.el and.seasonal variation across five d.fferent breed.ng stages based.on record.ngs of more than 50,000 songs from 34 ***:d.ring the pre-breed.ng stage, prior to female arrival, males sang a pronounced.d.wn chorus with a peak in song output d.ring the early *** the breed.ng stage,in contrast,the d.wn chorus was d.minished.and.males instead.exhibited.a pronounced.d.sk chorus with a peak in song output d.ring the *** the breed.ng season,the highest levels of song output occurred.in late April and.early May,soon after males arrived.on the breed.ng ground.,and.the lowest levels occurred.in August,prior to the d.parture of bird. for the wintering ***:These patterns suggest that Savannah Sparrows' early-season d.wn choruses are d.rected.at males and.serve a territorial d.fense ***-season d.sk choruses,in contrast, appear to play a role in attracting mates and.possibly acoustic mate guard.ng.

关键词： Bird song Breed.ng activities Circad.an rhythms Seasonal variation in song

Quiet in the nest:The nest environment attenuates song in a grassland.songbird

在线全文

学校读者我要写书评

暂无评论

Avian Research 2023年第4期14卷 623-629页

作者： Sarah L.d.bney Mikayla M.K.Bornais d.Ryan Norris Amy E.M.Newman heather Williams Stéphanie M.d.ucet d.niel J.Mennill d.partment of Integrative Biology University of WindsorWindsorOntarioN9B 3P4Canada d.partment of Integrative Biology University of GuelphGuelphOntarioN1G 2W1Canada Biology d.partment Williams CollegeWilliamstownMA01267USA

The nest environment may limit the ability of nest-bound.bird. to hear sound. from the outsid. *** vocal learning species,such as humans and.songbird.,it is vital for young animals to hear the voices of conspecific animals early in *** songbird.,nest structure varies consid.rably across species,and.the resulting impact on sound.transmission may have consequences for vocal learning in *** this stud.,we tested.the hypothesis that the nest environment attenuates song of Savannah Sparrows(Passerculus sand.ichensis),grassland.songbird. that build.nests on the ground.und.r cover of d.nse *** record.d.live Savannah Sparrows singing at variable d.stances from 21 *** record.d.songs using one microphone insid. the nest(the typical position of a nestling)and.another placed.1 m d.rectly above the nest(a typical position of an ad.lt).We found.a substantial red.ction in signal-to-noise ratio,where songs record.d.insid. the nest were an average of 11 d. lower than songs record.d.d.rectly above the *** estimate that the attenuation imposed.by the nest red.ced.the maximum acoustic environment from 117.7 m(for record.ngs above the nest),to 78.6 m(for record.ngs within the nest),which is analogous to listening from a position 39.1 m farther away from the *** research estimated.that song transmits up to 100 m in this species,so any ad.lt male within 100 m of a young bird.was previously consid.red.a potential vocal *** red.cing the nestling acoustic environment from 100 m to 78.6 m,the number of male tutors available to nestlings is red.ced.by an average of 27%.Given the growing evid.nce that song learning begins very early in life,future research on vocal d.velopment should.account for how the structural properties of the natal environment affect the songs that nestlings hear.

关键词： Acoustic environment Nest environment Songbird Sound.attenuation Vocal learning

ENVIRONMENTAL SCIENCE : 9th ed.

在线全文

学校读者我要写书评

暂无评论