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Denatured proteins as a novel template for the synthesis of well-defined,ultra-stable and water-soluble metal nanostructures for catalytic applications

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Journal of Leather Science and Engineering 2020年第1期2卷 66-76页

作者： Chaojian Chen david Yuen wah ng Tanja weil Max Planck Institute for Polymer Research Ackermannweg 1055128 MainzGermany Ulm University Albert-Einstein-Allee 1189081 UlmGermany

The templated synthesis of noble metal nanoparticles using biomass,such as proteins and polysaccharides,has generated great interest in recent *** this work,we report on denatured proteins as a novel template for the preparation of water-soluble metal nanoparticles with excellent stability even after high speed centrifugation or storage at room temperature for one *** noble metal nanoparticles including spherical gold and platinum nanoparticles as well as gold nanoflowers are obtained using sodium borohydride or ascorbic acid as the reducing *** particle size can be controlled by the concentration of the *** metal nanoparticles are further used as catalysts for the hydrogenation reaction of p-nitrophenol to ***,spherical gold nanoparticles with an average size of 2 nm show remarkable catalytic performance with a rate constant of 1.026×10^(-2) L s^(-1) mg^(-1).These metal nanoparticles with tunable size and shape have great potential for various applications such as catalysis,energy,sensing,and biomedicine.

关键词： Unfolded proteins Gold nanoparticles Gold nanoflowers Platinum nanoparticles Biotemplated synthesis Catalysis

Modeling and optimization of the cyclic steady state operation of adsorptive reactors

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Chinese Journal of Chemical Engineering 2018年第6期26卷 1321-1329页

作者： Mamoon Hussainy david w.Agar Technical University of Dortmund Faculty of Bio-and Chemical EngineeringLaboratory for Chemical Reaction Engineering

Adsorptive reactors(AR),in which an adsorptive functionality is incorporated into the catalytic reactors,offer enhanced performance over their conventional counterparts due to the effective manipulation of concentration and temperature *** operation of these attractive reactors is,however,inherently unsteady state,complicating the design and operation of such sorption-enhanced *** order to capture,comprehend and capitalize upon the rich dynamic texture of adsorptive reactors,it is necessary to employ cyclic steady state algorithms describing the entire reaction-adsorption/desorption *** stability of this cyclic steady state is of great importance for the design and operation of adsorptive *** this paper,the cyclic steady state of previously proposed novel adsorptive reactor designs has been calculated and then optimized to give maximum space–time *** results obtained revealed unambiguously that an improvement potential of up to multifold level could be attained under the optimized cyclic steady state *** additional improvement resulted from the reduction of the regeneration time well below the reaction-adsorption time,which means,in turn,more space–time yield.

关键词： Adsorptive reactors Multifunctional reactors Cyclic steady state Claus reaction Deacon reaction

More than mimicry？ Evaluating scope for flicker-fusion as a defensive strategy in coral snake mimics

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Current Zoology 2014年第1期60卷 123-130页

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

Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping predators through a ＂flicker-fusion＂ effect. According to this hypothesis, banded color patterns confuse potential predators when a snake transitions from resting to moving because its bands blur together to form a different color. To produce this motion blur, a moving snake＇s bands must transition faster than the critical flicker-fusion rate at which a predator＇s photoreceptors can refresh. It is unknown if coral snakes or their mimics meet this requirement. we tested this hypothesis by measuring the movement speed and color pat- terns of two coral snake mimics, Lampropeltis triangulum campbelli and L. elapsoides, and comparing the frequency of color transitions to the photoreceptor activity of the avian eye. we found that snakes often produced a motion blur, but moving snakes created a blurring effect more often in darker conditions, such as sunrise, sunset, and nighttime when these snakes are often active. Thus, at least two species of coral snake mimics are capable of achieving flicker-fusion, indicating that their color patterns may confer an additional defense aside from mimicry

关键词： Coral snake mimicry Flicker-fusion effect CFF Kingsnake Defensive strategy

Pterosaur Research:Recent Advances and a Future Revolution

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Acta Geologica Sinica(English Edition) 2012年第6期86卷 1366-1376页

作者： david w.E.HONE Department of Earth Sciences University of Bristol School of Biological and Chemical Sciences Queen Mary University of London

In the years since the first description of a pterosaur specimen in 1784, pterosaur research has inevitably advanced considerably. However the last decade has arguably seen a much greater increase in our knowledge than the preceding two centuries. Since the turn of the new millennium, more than 40 new pterosaur genera and species have been described and whole new clades have been discovered, in addition to much new data being developed on pterosaur anatomy, functional morphology, palaeobiology, systematics, ecology and more. we are perhaps at the start of a golden age of pterosaur research and much as the dinosaurs underwent a revolution in the 1970s through to the early 1990s, now the Pterosauria are taking their turn. There is also a new and wider interest in pterosaur work as it attracts both more researchers and greater public interest. Pterosaurs appear to be an increasingly popular aspect of paleontology in popular culture and of interest to the media, both mainstream and digital.

关键词： paleontology Pterosauria science history of research academia

Inducible competitors and adaptive diversification

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Current Zoology 2013年第4期59卷 537-552页

作者： Beren w. ROBINSON david w. PFENNIG Department of Integrative Biology University of Guelph Guelph Ontario N 1G 2W 1 Canada Department of Biology University of North Carolina Chapel Hill NC 27599 USA

Identifying the causes of diversification is central to evolutionary biology. The ecological theory of adaptive diversi- fication holds that the evolution of phenotypic differences between populations and species--and the formation of new spe- cies-stems from divergent natural selection, often arising from competitive interactions. Although increasing evidence suggests that phenotypic plasticity can facilitate this process, it is not generally appreciated that competitively mediated selection often also provides ideal conditions for phenotypic plasticity to evolve in the first place. Here, we discuss how competition plays at least two key roles in adaptive diversification depending on its pattern. First, heterogenous competition initially generates heterogeneity in resource use that favors adaptive plasticity in the form of ＂inducible competitors＂. Second, once such competitively induced plas- ticity evolves, its capacity to rapidly generate phenotypic variation and expose phenotypes to alternate selective regimes allows populations to respond readily to selection favoring diversification, as may occur when competition generates steady diversifying selection that permanently drives the evolutionary divergence of populations that use different resources. Thus, competition plays two important roles in adaptive diversification---one well-known and the other only now emerging--mediated through its effect on the evolution ofphenotypic plasticity

关键词： Phenotypic plasticity Competition Adaptive radiation Character displacement Genetic assimilation Resourcepolymorphism

Factors influencing mercury accumulation in three species of forage fish from Caddo Lake, Texas, USA

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Journal of Environmental Sciences 2010年第8期22卷 1158-1163页

作者： Matthew M Chumchal Ray w Drenner david R Cross K david Hambright Department of Biology Texas Christian University 2800 S. University Dr Department of Psychology Texas Christian University 2800 S. University Dr Program in Ecology and Evolutionary Biology Biological Station and Department of Zoology 730 Van Vleet Oval University of Oklahoma

Most studies that have examined mercury （Hg） contamination of fish have focused on game species feeding near the top of the food web, while studies that examine forage fish that feed near the base of the food web are rare. we conducted a survey of Hg contamination in three species of forage fish, brook silverside （Labidesthes sicculus）, threadfin shad （Dorosoma petenense） and gizzard shad （Dorosoma cepedianum）, from Caddo Lake, Texas, USA and found species-specific differences in Hg concentrations. we examined total length, age, trophic position （determined using δ15N）, and growth rate of forage fish as factors that could have influenced within-and between-species differences in Hg concentration. Total length and age were the best predictors of within-species differences in Hg concentration. Between-species differences in Hg concentrations were most strongly influenced by trophic position.

关键词： mercury trophic position forage fish

Barriers to advancing nanotechnology to better improve and translate nanomedicines

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Frontiers of Chemical Science and Engineering 2014年第3期8卷 265-275页

作者： Yuwei w.ng david w. Grainger Department of Pharmaceutics and Pharmaceutical Chemistry University of Utah Salt Lake City UT 84112-5820 USA

Engineered nanomaterials and nanotechnolo- gies promise many benefits to enhance both in vitro and in vivo performance. This is now manifest in the increasing number of reported biomedical products under develop- ment and testing that contain nanotechnologies as their distinguishing performance--enhancing components. In many cases, nano-sized materials are selected to provide a specific functional aspect that contributes to improved medical performance, either in vitro or in vivo. Nanopar- ticles are most commonly exploited in diverse roles in topical lotions and creams, solubilization aids, for in vitro and in vivo diagnostic and targeting agents in nanomedi- cines and theranostics. Despite fundamental scientific excitement and many claims to nanotechnology-based improvements in new biomedical applications, several fundamental and long-standing challenges remain to be addressed using nanomedicines to make clinically important progress. This review addresses several issues that must be fairly and objectively reported and then overcome to provide truly credible performance for nanomedicines.

关键词： nanotechnology nanomedicine drug delivery therapeutic targeted delivery

1D and 2D ~1H NMR studies on bisantrene complexes with short DNA oligomers

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Science China Chemistry 1995年第12期38卷 1462-1472页

作者：姚世杰 wILSON.w.david Department of Chemistry and Laboratory for Chemical and Biological Sciences Georgia State UniversityAtlantaGA30303USA

The binding of bisantrene to four DNA tetramers,d(CGCG)_2,d(GCGC)_2,d(CATG)_2, and d(GTAC)_2,was investigated by 1D and 2D NMR *** is.a well known anticancer drug and has been used clinically for *** is believed to be one of its cellular ***- suits from both ID and 2D 1H NMR are in agreement with an intercalation binding mode of bisantrene with the four DNA tetramers in this *** results further indicate that a threading intercalation birding mode,in which one bisantrene side chain is in the minor groove and the other in the major groove of DNA, is *** NMR results also suggest that bisantrene prefers binding at pyrimidine-(3',5')-purine intercalation sequences rather than at purine-(3',5')-pyrimidine *** intramolecular and intermolecular NOE contacts of bisantrene-DNA tetramer complexes indicate that a C2'-endo uniform sugar pucker,rather than a mixed sugar conformation,is preferred by the intercalation site of both the 5'-(TA)-3' and the 5'-(CG)-3' binding steps.

关键词： NOESY DNA bisantrene intercalation threading intercalation uniform intercalation geometry.

Uncommon presentation of a common disease-Bouveret's syndrome:A case report and systematic literature review

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world Journal of Gastrointestinal Surgery 2017年第1期9卷 25-36页

作者： Yahya AL-Habbal Matthew.ng david Bird Trevor McQuillan Haytham AL-Khaffaf Department of Surgery Box Hill Hospital Department of Surgery the Northern Hospital East Lancashire Hospitals NHS Trust the Royal Blackburn Hospital

AIM To investigate and summarise the current evidence surrounding management of Bouveret's syndrome(BS).METHODS A MEDLINE search was performed for the BS. The search was conducted independently by two clinicians(Yahya ALHabbal and Matthew.ng) in April 2016. A case of BS is also *** A total of 315 articles, published from 1967 to 2016, were found. For a clinically meaningful clinical review, articles published before 01/01/1990 and were excluded, leaving 235 unique articles to review. Twenty-seven articles were not available(neither by direct communication nor through inter-library transfer). These were also excluded. The final number of articles reviewed was 208. There were 161 case reports, 13 reviews, 23 images(radiological and clinical images), and 11 letters to editor. Female to male ratio was 1.82. Mean age was 74 years. Treatment modalities included laparotomy in the majority of cases, laparoscopic surgery, endoscopic surgery and shockwave *** There is limited evidence in the literature about the appropriate approach. we suggest an algorithm for management of BS.

关键词： Bouveret’s syndrome Biliary anomalies Endoscopy Digestive system Duodenal obstruction diagnosis Gallstones surgery Gallstones complications Duodenal obstruction etiology Duodenal obstruction surgery Intestinal fistula diagnosis Humans