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4-Amino-1,8-naphthalimide based fluorescent photoinduced electron transfer (PET) pH sensors as liposomal cellular imaging agents: The effect of substituent patterns on PET directional quenching

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 61-75页

作者： Miguel Martinez-Calvo Sandra A.Bright Emma B.Veale Adam F.Henwood d.Clive williams Thorfinnur Gunnlaugsson School of Chemistry and Trinity Biomedical Sciences Institute(TBSI) Trinity College DublinThe University of DublinDublin 2Ireland School of Biochemistry and Immunology and Trinity Biomedical Sciences Institute(TBSI) Trinity College DublinThe University of DublinDublin 2Ireland Centro Singular de Investigacion en Quimica Bioloxica e Materiais Moleculares(CIQUS)and departamento de Quimica Organica Universidade de Santiago de Compostela Rua Jenaro de la Fuente s/n15782Santiago de CompostelaSpain

Four new fluorescent sensors(1-4)based on the 4-amino-1,8-naphthalimide fluorophores(Naps)have been synthesized based on the classical fluorophore-spacer-receptor *** four compounds all gave rise to emission bands centred at ca.535 nm,which were found to be highly pH dependent,the emission being‘switched on’in acidic media,while being quenched due to PET from the amino moieties to the excited state of the Nap at more alkaline *** luminescent pH dependence for these probes was found to be highly dependent on the substitution on the imide site,as well as the polyamine chain attached to the position 4-amino *** the case of sensor 2 the presence of the 4-amino-aniline dominated the pH dependent ***,at higher pH,PET quenching was also found to occur from the polyamine ***,2 is better described as a receptor1-spacer1-fluorophore-spacer2-receptor2 system,where the dominant PET process is due to(normally less favourable)‘directional’PET quenching from the 4-amino-aniline unit to the Nap *** trends and pH fluorescence dependences were also seen for 3 and *** compounds were also tested for their imaging potential and toxicity against HeLa cells(using dRAQ5 as nuclear stain which does now show pH dependent changes in acidic and neutral pH)and the results demonstrated that these compounds have reduced cellular viability at moderately high concentrations(with IC50 values between ca.8-30μmol?L^?1),but were found to be suitable for intracellular pH determination at 1μmol?L^?1 concentrations,where no real toxicity was *** allowed us to employ these as lysosomal probes at sub-toxic concentrations,where the Nap based emission was found to be pH depended,mirroring that seen in aqueous solution for 1-4,with the main fluorescence changes occurring within acidic to neutral pH.

关键词： sensors pH photoinduced electron transfer cellular imaging confocal microscopy

Obsolescence optimization of electronic and mechatronic components by considering dependability and energy consumption

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Journal of Central South University 2013年第5期20卷 1221-1225页

作者： M.A.Mellal S.Adjerid d.Benazzouz S.Berrazouane E.J.williams Solid Mechanics and System Laboratory Faculty of Engineering Sciences (FSI)M'Hamed Bougara University Faculty of Engineering Sciences (FSI) M'Hamed Bougara University decision Sciences College of BusinessUniversity of Michigan Industrial and Manufacturing Systems Engineering department College of Engineering and Computer ScienceUniversity of Michigan

Nowadays, rapid technological progress influences the dependability of equipments and also causes rapid obsolescence. The mechatronic and electronic equipment components are mostly affected by obsolescence. A new challenger unit possesses identical functionalities, but with higher performances. This work aims to find the optimal number of components which should be replaced by new-type units, under budgetary constraints. In this work, the new challenger unit is characterized by lower energy consumption and the optimization steps are based on genetic algorithm (GA). The result shows the importance of this type of replacement in order to economize energy consumption and to deal with obsolescence.

关键词： obsolescence lower energy consumption mechatronic and electronic components genetic algorithm

Rangeland hillslope lengths:A case study at the Walnut Gulch Experimental Watershed,southeastern Arizona

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International Soil and Water Conservation Research 2022年第4期10卷 597-609页

作者： Li Li Mark A.Nearing Philip Heilman Mary H.Nichols d.P.Guertin C.J.williams School of Natural Resources and the Environment University of ArizonaTucsonAZ85705USA USdA-Agricultural Research Service Southwest Watershed Research CenterTucsonAZ85719USA

Rangeland hillslopes provide much of the sediment supplied to channel systems and their lengths exert a fundamental constraint on hillslope diffusive ***,information regarding lengths of rangeland hillslopes,and how best to estimate them,is *** this study,three groups of watersheds(10 in total)were selected from the Walnut Gulch Experimental Watershed according to their geology,soil and vegetation *** 1 watersheds were at lower elevations dominated by shrubs,Group 3 were at high elevations dominated by grass,and Group 2 were mixed shrub and *** hillslope lengths were calculated from 1 m-resolution dEMs using three methods:a flow routing algorithm,slope-area relationships,and inverted relationship with drainage *** that characterize the current watersheds,including Hack's exponent and coefficient,watershed shape coefficient,channel concavity and steepness,and surface roughness,were quantified and related to hillslope *** shows:(1)estimated hillslope lengths were different for the three methods and between the three groups of watersheds;(2)hillslope lengths that measured from the flow routing algorithm for the ten selected watersheds primarily ranged from 30 to 100 m,with a median value of 63.0 m,which was 20%e50%greater than those derived from slope-area plots or drainage densities;(3)hillslope lengths estimated from the flow routing method were greater in Group 3 watersheds than in Group 2 and then in Group 1 *** attributed these differences in hillslope lengths to the historic epeirogenic pulses,watershed and drainage network morphology,and differences in vegetation characteristics;(4)measured hillslope lengths from the flow routing algorithm were best correlated with hillslope relief,then surface roughness,channel steepness and *** results would benefit the applications of hydrological and erosion models in rangelands.

关键词： Rangeland hillslope Slope length drainage density Slope-area relationship Hillslope hydrology

A Methodology to Measure the Environmental Impact of ICT Operating Systems across different device Platforms

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Journal of Electronic Science and Technology 2015年第3期13卷 255-263页

作者： daniel R.williams Yinshan Tang the Technologies for Sustainable Built Environments (TSBE) Centre University of Reading the Henley Business School University of Reading

A new methodology was created to measure the energy consumption and related green house gas （GHG） emissions of a computer operating system （OS） across different device platforms. The methodology involved the direct power measurement of devices under different activity states. In order to include all aspects of an OS, the methodology included measurements in various OS modes, whilst uniquely, also incorporating measurements when running an array of defined software activities, so as to include OS application management features. The methodology was demonstrated on a laptop and phone that could each run multiple OSs, results confirmed that OS can significantly impact the energy consumption of devices. In particular, the new versions of the Microsoft Windows OS were tested and highlighted significant differences between the OS versions on the same hardware. The developed methodology could enable a greater awareness of energy consumption, during both the software development and software marketing processes.

关键词： Environment green information and communications technology operating system sustainability.

Gaia Journeys: a museum-based immersive performance exploration of the Earth

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International Journal of digital Earth 2009年第1期2卷 44-58页

作者： K.C.Yu K.williams d.Neafus L.Gaston G.downing department of Space Sciences Denver Museum of Nature&ScienceDenverColoradoUSA Remedy Arts LLC New York CityNYUSA dept.Music&Entertainment Industry Studies University of Colorado at DenverDenverColoradoUSA xRez Studios Los AngelesCaliforniaUSA

Gaia Journeys is a collaborative multimedia musical and virtual reality art performance conceived by author williams,with the aid of staff at the denver Museum of Nature&*** by astronauts who spoke of seeing a border-less world from orbit,Gaia Journeys’chief goal was to deliver this experience to museum audiences via photo-realistic virtual depictions of the Earth(from orbit as well as via spherical photographic panoramas taken from the ground)choreographed to live musical *** Journeys took place in the high resolution digital‘fulldome’Gates Planetarium,withwilliams playing the violin and keyboards,enhancing a previously recorded backing track,while visuals were generated with SCISS AB’s *** eight tracks of audio were three-dimensionally spatialised to the 16.4 sound system of the Gates Planetarium,providing an immersive sound experience to match the *** audience feedback was generally positive,with great interest in repeat or similar future *** visitor evaluations suggest the potent power of the new class of digital planetaria for displaying virtual globe datasets to the public,via both multimedia entertainment like Gaia Journeys as well as traditional lectures.

关键词： digital planetarium museums immersive displays virtual reality musical performance

Heterogeneous molecular catalysts for electrocatalytic CO2 reduction

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Nano Research 2019年第9期12卷 2093-2125页

作者： Nathan Corbin Joy Zeng Kindle williams Karthish Manthiram department of Chemical Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA

This review provides an overview of the literature regarding heterogeneous molecular catalysts for electrochemical CO2 reduction (ECR).Fundamental aspects of the science,including aggregation,electrochemical rate laws,and electrode-catalyst electronic coupling,are discussed to provide a solid foundation on which to design experiments and interpret *** aspects of ECR are presented based on electrokinetic and spectroscopic measurements as well as density functional theory (dFT) *** is improving for electrokinetic measurements,but the redox state of the metal center under reaction conditions and dFT reaction pathways lack agreement in the *** the tunable aspects of the molecular catalyst,the impacts of the metal center,ligand substituents,and electrode support on the activity and selectivity toward ECR are presented with an emphasis on those studies that controlled for aggregation and minimized mass-transport *** three-dimensional (3d) structures such as polymers,metal-organic frameworks (MOFs),and covalent-organic frameworks (COFs) are discussed as highly tunable architectures that begin to mimic the catalytic pockets of enzyme active *** achieve the full potential of these catalysts,design principles must emerge based on a combination of deconvoluting measurements to extract intrinsic catalyst properties and more reliable theoretical calculations to predict reaction pathways.

关键词： CO2 reduction electrocatalysis porphyrins phthalocyanines molecular complexes heterogeneous catalysis

Comment on“In vivo flow cytometry reveals a circadian rhythm of circulating tumor cells”

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Light(Science & Applications) 2021年第10期10卷 1998-1999页

作者： Amber L.williams Jessica E.Fitzgerald Fernando Ivich Eduardo dSontag Mark Niedre department of Bioengineering Northeastern UniversityBostonMAUSA department of Electrical and Computer Engineering Northeastern UniversityBostonMAUSA Laboratory of Systems Pharmacology Harvard Medical SchoolBostonMAUSA

dear Editor,Circulating tumor cells(CTCs)are instrumental in hematogenous metastasis and are widely studied using liquid biopsy *** involve analysis and characterization of CTCs from fractionally small blood samples drawn from *** biopsy implicitly assumes that the number and phenotypical distribution of CTCs in small blood samples is representative of the full peripheral blood volume,and furthermore that CTC numbers are approximately constant over the days and hours surrounding the blood draw.

关键词： biopsy metastasis furthermore

Evaluation of the mood repair hypothesis of compulsive buying

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Open Journal of Psychiatry 2012年第2期2卷 83-90页

作者： Alishia d. williams Clinical Research Unit for Anxiety and depression University of New South Wales at St. Vincent’s Hospital Sydney Australia

Compulsive buying (CB) is a proposed disorder of dysregulated buying behaviour that is associated with high rates of Axis I comorbidity, particularly depression and anxiety. It has been proposed that purchasing behaviours may serve as a maladaptive means of alleviating negative affect in vulnerable individuals. The aim of the current study was to experimentally manipulate affect to test this mood repair hypothesis. Compulsive buyers (n = 26) and pathological gamblers (n = 23) diagnosed using structured clinical interviews (SCId) and healthy controls (n = 24) were randomly assigned to either a negative or positive mood-induction procedure (MIP) and participated in an experimental buying task. Results revealed that, irrespective of mood induction condition, compulsive buyers reported a greater urge to acquire items, purchased more items, and spent a greater total amount of money during the buying task when compared to the healthy control group. Compulsive buyers were also faster than pathological gamblers in making decisions to purchase, even after controlling for motor impulsivity (BIS). There was, however, no main effect of mood-induction condition or group by condition interaction. Limitations and future directions are discussed.

关键词： Compulsive Buying Acquisition Mood Repair depression

How do molecular interactions affect fluorescence behavior of AIEgens in solution and aggregate states?

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Science China Chemistry 2022年第1期65卷 135-144页

作者： Ying Yu Hao Xing Zhicong Zhou Junkai Liu Herman H-YSung Ian d.williams Jonathan E.Halpert Zheng Zhao Ben Zhong Tang department of Chemistry the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionDepartment of Chemical and Biomedical EngineeringInstitute for Advanced Studyand Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional MaterialsThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Shenzhen Institute of Molecular Aggregate Science and Engineering School of Science and EngineeringChinese University of Hong KongShenzhenGuangdong518172China department of chemistry The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina AIE Institute Guangzhou Development DistrictHuangpuGuangzhou 510530China

Molecular interactions are crucial in diverse fields of protein folding,material science,nanotechnology,and life *** mounting experimental research controls luminescent behavior by adjusting molecular interactions in light-emitting materials,it remains elusive to correlate microscopic molecular interactions with macroscopic luminescent behavior ***,we synthesized three red luminogens with subtle structural variation and investigated the influence of molecular interactions on their luminescent behavior in solution and aggregate *** results indicate that strongπ-πand d-A interactions in both dilute solution(between luminogen and solvent molecules)and aggregate(between luminogens)states cause the redshift in emission,while weak interactions(e.g.,Van der Waals,C–H…π,and C–H…F interactions)enhance the quantum *** work provides a thoughtful investigation into the complicated influence of various molecular interactions on luminescent behavior.

关键词： molecular interactions fluorescence behaviors AIEgens aggregates

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