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Impact of device resistances in the performance of graphene‑based terahertz photodetectors

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Frontiers of Optoelectronics 2024年第2期17卷 87-97页

作者： O.Castelló Sofía M.López Baptista K.Watanabe T.Taniguchi E.Diez j.E.Velázquez-Pérez Y.M.Meziani j.M.Caridad j.A.Delgado-notario Department of Applied Physics University of Salamanca37008 SalamancaSpain Unidad de Excelencia en Luz y Materia Estructurada(LUMES) University of Salamanca37008 SalamancaSpain Research Center for Electronic and Optical Materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for Materials nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and *** features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and ***,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic *** this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFET *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical *** findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.

关键词： Graphene THz Photodetector Field-effect transistor Plasmonic

Human Eosinophil Cell Manipulation by Optical Tweezers

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Open journal of Biophysics 2024年第3期14卷 330-338页

作者： Pavel Yale jean Michel Edoukoua Konin Abadê Ange-Boris n’guessan Michel Abaka Kouacou jérémie T. Zoueu Laboratoire dInstrumentation Image et Spectroscopie (L2IS) Institut National Polytechnique Houphout-Boigny (INPHB) Yamoussoukro Cte dIvoire Laboratoire de Chimie et de Physique Appliques Sciences et Techniques Universit Alassane Ouattara Bouak Cte dIvoire

In this work, lateral deformation of human eosinophil cell during the lateral indentation by an optically trapped microbead of diameter 4.5 µm is studied. The images were captured using a CCD camera and the Boltzmann statistics method was used for force calibration. Using the Hertz model, we calculated and compared the elastic moduli resulting from the lateral force, showing that the differences are important and the force should be considered. Besides the lateral component, the setup also allows us to examine the lateral cell-bead interaction. The mean values of the properties obtained, in particular the elastic stiffness and the shear stiffness, were Eh = (37.76 ± 2.85) µn/m and Gh = (12.57 ± 0.32) µn/m. These results show that the lateral indentation can therefore be used as a routine method for cell study, because it enabled us to manipulate the cell without contact with the laser.

关键词： Optical Tweezers Human Eosinophil Cell Indentation Shear Stiffness

The HIF-1α/PLOD2 axis integrates extracellular matrix organization and cell metabolism leading to aberrant musculoskeletal repair

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Bone Research 2024年第2期12卷 289-301页

作者： Heeseog Kang Amy L.Strong Yuxiao Sun Lei Guo Conan juan Alec C.Bancroft ji Hae Choi Chase A.Pagani Aysel A.Fernandes Michael Woodard juhoon Lee Sowmya Ramesh Aaron W.james David Hudson Kevin n.Dalby Lin Xu Robert j.Tower Benjamin Levi Center for Organogenesis Regeneration and TraumaDepartment of SurgeryUniversity of Texas SouthwesternDallasTX 75390USA Section of Plastic Surgery Department of SurgeryUniversity of MichiganAnn ArborMI 48109USA Quantitative Biomedical Research Center Peter O’Donnell Jr.School of Public HealthUniversity of Texas SouthwesternDallasTX 75390USA Department of Orthopedics and Sports Medicine University of WashingtonSeattleWA 98195USA Division of Chemical Biology and Medicinal Chemistry College of PharmacyUniversity of Texas at AustinAustinTX 78712USA Department of Pathology Johns Hopkins UniversityBaltimoreMD 21218USA

While hypoxic signaling has been shown to play a role in many cellular processes,its role in metabolism-linked extracellular matrix(ECM)organization and downstream processes of cell fate after musculoskeletal injury remains to be ***(HO)is a debilitating condition where abnormal bone formation occurs within extra-skeletal *** andhypoxia-inducible factor 1α(HIF-1α)activation have been shown to promote ***,the underlying molecular mechanisms bywhich the HIF-1αpathway in mesenchymal progenitor cells(MPCs)contributes to pathologic bone formation remain to ***,we used a proven mouse injury-induced HO model to investigate the role of HIF-1αon aberrant cell ***-cell RnA sequencing(scRnA-seq)and spatial transcriptomics analyses of the HO site,we found that collagen ECM organizationis the most highly up-regulated biological process in *** mesenchymal cell-specific deletion of Hif1α(Hoxa11-CreER^(T2);Hif1a^(fl/fl))significantly mitigated HO in ***-seq analysis of these Hoxa11-CreER^(T2);Hif1a^(fl/fl)mice identified the PLOD2/LOXpathway for collagen cross-linking as downstream of the HIF-1αregulation of ***,our scRnA-seq data and mechanisticstudies further uncovered that glucose metabolism in MPCs is most highly impacted by HIF-1α*** a translational aspect,a pan-LOX inhibitor significantly decreased HO.A newly screened compound revealed that the inhibition of PLOD2 activity in MPCssignificantly decreased osteogenic differentiation and glycolytic *** suggests that the HIF-1α/PLOD2/LOX axis linked tometabolism regulates HO-forming MPC *** results suggest that the HIF-1α/PLOD2/LOX pathway represents a promisingstrategy to mitigate HO formation.

关键词： metabolism skeletal aberrant

On the Trail of Self-Directed Online Learners

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ECnU Review of Education 2024年第2期7卷 406-419页

作者： Curtis j.Bonk 朱美娜 School of Education Indiana University201 N.Rose AvenueBloomingtonIN 4740lUSA Wayne State University

Purpose We describe a series of more than a dozen studies on self-directed online learning spanning over a ***/Approach/Methods We incorporated surveys,interviews,focus groups,and content analyses into these research studies,which initially targeted the goals,motivations,and challenges of learners using open educational resources and OpenCourseWare and then focused on learning from massive open online courses(MOOCs).This research accelerated after creating a database of over 3,000 MOOC instructors,through which we explored cultural sensitivity and personalization practices in MOOCs as well as instructional design considerations and challenges,MOOC instructor professional development and career development,instructor motivation and engagement,and student and instructor perceptions of self-directed *** This study reveals that self-directed online learners(SDOLs)seek learning environments offering freedom,choice,control,and a sense of autonomy and that both learners and instructors have intrinsic motivation for engaging in open online learning ***/Value Based on this research with both MOOC instructors and MOOC learners,we offer instructional design guidelines to address SDOLs’needs and assist in efforts to foster a new generation of SDOLs.

关键词： MOOCs motivation online learning self-directed learning self-management self-monitoring

CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)

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journal of Rare Earths 2024年第9期42卷 1669-1681,I0002页

作者： j.C.Martínez-Munuera M.P.Yeste A.García-García MCMA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR ***,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

Optimizing laser coupling,matter heating,and particle acceleration from solids using multiplexed ultraintense lasers

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Matter and Radiation at Extremes 2024年第4期9卷 16-28页

作者： Weipeng Yao Motoaki nakatsutsumi Sébastien Buffechoux Patrizio Antici Marco Borghesi Andrea Ciardi Sophia n.Chen Emmanuel d’Humières Laurent Gremillet Robert Heathcote Vojtech Horny Paul McKenna Mark n.Quinn Lorenzo Romagnani Ryan Royle Gianluca Sarri Yasuhiko Sentoku Hans-Peter Schlenvoigt Toma Toncian Olivier Tresca Laura Vassura Oswald Willi julien Fuchs LULI-CnRS CEASorbonne UniversitéEcole PolytechniqueInstitut Polytechnique de ParisF-91128 Palaiseau CedexFrance Sorbonne Université Observatoire de ParisUniversité PSLCNRSLERMAF-75005 ParisFrance InRS-EMT 1650 BoulLionel-BouletVarennesQuebec J3X 1S2Canada Center for Plasma Physics School of Mathematics and PhysicsQueen’s University BelfastBelfast BT71NNUnited Kingdom “Horia Hulubei”national Institute for Physics and nuclear Engineering 30 Reactorului StreetRO-077125 Bucharest-MagureleRomania University of Bordeaux Centre Lasers Intenses et ApplicationsCNRSCEAUMR 5107F-33405 TalenceFrance CEA DAMDIFF-91297 ArpajonFrance Université Paris-Saclay CEALMCE91680 Bruyères-le-ChatelFrance Central Laser Facility STFC Rutherford Appleton LaboratoryDidcotUnited Kingdom SUPA Department of PhysicsUniversity of StrathclydeGlasgow G40NGUnited Kingdom Department of Physics University of NevadaRenoNevada 89557USA Institute of Laser Engineering Osaka University2-6 YamadaokaSuitaOsaka 565-0871Japan Institut fur Laser und Plasmaphysik Heinrich Heine Universitat DusseldorfDusseldorfGermany

Realizing the full potential of ultrahigh-intensity lasers for particle and radiation generation will require multi-beam arrangements due to technology ***,we investigate how to optimize their coupling with solid ***,we show that overlapping two intense lasers in a mirror-like configuration onto a solid with a large preplasma can greatly improve the generation of hot electrons at the target front and ion acceleration at the target *** underlying mechanisms are analyzed through multidimensional particle-in-cell simulations,revealing that the self-induced magnetic fields driven by the two laser beams at the target front are susceptible to reconnection,which is one possible mechanism to boost electron *** addition,the resistive magnetic field generated during the transport of the hot electrons in the target bulk tends to improve their *** simulations also indicate that such effects can be further enhanced by overlapping more than two laser beams.

关键词： laser acceleration particle

A multi-shot target wheel assembly for high-repetition-rate, laser-driven proton acceleration

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High Power Laser Science and Engineering 2024年第2期12卷 87-94页

作者： j.Penas A.Bembibre D.Cortina-Gil L.Martin A.Reija C.Ruiz M.Seimetz A.Alejo j.Benlliure Instituto Galego de Fisica de Altas Enerxias Universidade de Santiago de CompostelaSantiago de CompostelaSpain Laboratorio Laser de Aceleracion y Aplicaciones RIAIDTUniversidade de Santiago de CompostelaSantiago de CompostelaSpain Instituto Universitario de Física Fundamental y Matematicas y Dpto.de Didactica de la Matematica y de las Ciencias Experimentales Universidad de SalamancaSalamancaSpain Instituto de Instrumentación para Imagen Molecular(I3M) CSIC-Universitat Politecnica de ValenciaValenciaSpain

A multi-shot target assembly and automatic alignment procedure for laser–plasma proton acceleration at high repetition rate are *** assembly is based on a multi-target rotating wheel capable of hosting more than 5000 targets,mounted on a 3D motorized stage to allow rapid replenishment and alignment of the target material between laser *** automatic alignment procedure consists of a detailed mapping of the impact positions at the target surface prior to the irradiation that ensures stable operation of the target,which alongside the purpose-built design of the target wheel,enables operation at rates up to 10 *** and continuous laser-driven proton acceleration at 10 Hz is demonstrated,with observed cut-off energy stability about 15%.

关键词： high repetition rate laser-plasma acceleration multi-shot operation proton source target assembly

Ecosystem Services of Grazed Grasslands in the Flooding Pampa

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Phyton-International journal of Experimental Botany 2024年第6期93卷 1179-1202页

作者： Elizabeth j.jacobo Adriana M.Rodríguez Facultad de Agronomía Área de AgroecologíaUniversidad de Buenos AiresBuenos Aires1417Argentina Facultad de Agronomía Departamento de Producción AnimalUniversidad de Buenos AiresBuenos Aires1417Argentina

The Flooding Pampa grasslands are the last remnant of the Rio de la Plata grasslands in ***-genic interventions have led to severe degradation and,as a result,the ecosystem services provided by the grass-lands are declining,in terms of provisioning,regulating,and supporting *** synthesized the existing literature on the ecosystem goods and services provided by these grasslands under grazing in different conditions and conservation *** found that plant and animal diversity and primary production are the most studied ecosystem services,while climate regulation,water supply,nutrient cycling,meat production and erosion control,in that order,are less *** services are *** grazing and glyphosate spraying are the main drivers of grassland *** grazing and conservative stocking rates have been shown to reverse degradation and demonstrate that livestock production is compatible with ecosystem conserva-tion by maintaining regulating and provisioning *** these management strategies are poorly integrated,improving their implementation will require important changes in farmers’decisions and the development of policies that create the economic conditions for this to *** is needed to understand the conditions that prevent the knowledge generated from being transferred to producers and translated into practices that would improve the provision of ecosystem services.

关键词： Salado basin sustainability biodiversity rangelands meat production adaptative multi paddock grazing process technologies agroecology

Evaluation of corneal parameter changes under different accommodative stimuli with Scheimpflug imaging-based tomography

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国际眼科杂志 2024年第9期24卷 1357-1366页

作者： Farid j Bedrán-García David P Piñero Department of Optics Pharmacology and AnatomyUniversity of AlicanteAlicante 03690Spain

AIM:To evaluate the reliability of measurements of corneal changes with accommodation in healthy eyes using a Scheimpflug imaging-based system and how these measurements distribute in the normal ***:Prospective,non-randomized,comparative study including 27 healthy subjects(54 eyes),including emmetropia(13 eyes),myopia(17 eyes),hyperopia(4 eyes)and astigmatism(20 eyes)*** all cases,a complete eye examination was performed,including the analysis of corneal changes with different accommodative stimuli(+2.00,0.00 and-3.00 D)using the Pentacam AXL *** investigation was structured in 2 phases:repeatability analysis and characterization of accommodation-related corneal changes in healthy ***:In the repeatability analysis,the index of height asymmetry(IHA)showed the greatest variability with the three accommodative stimuli,being the results for the rest of parameters *** group of emmetropes showed significant differences with accommodative changes in the position of maximum keratometry(Kmax;Pn the astigmatism group,significant changes were not only observed in the position of Kmax,but also in minimum corneal thickness(MCT),corneal spherical aberration,and total and low order aberration root mean square(all Pnificant difference was found in the displacement of the X position of Kmax with+2.00 D and-3.00 D in the myopia group(P=0.033)as well as in changes with+2.00 D and-3.00 D in the magnitude of the position vector of Kmax in the emmetropia group(Pno significant changes were found between accommodative stimuli in the displacement of coordinates of MCT(P≥0.109).COnCLUSIOn:The position of Kmax and MCT in healthy corneas can change significantly when presenting different accommodative stimuli using the accommodation mode of the Pentacam system,with different trends in these accommodation-related corneal changes between refractive ***,the consistency of the measurement

关键词： corneal biomechanics keratometry corneal thickness pachymetry corneal aberrations Pentacam accommodation