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microscopy Observations of Habitable Space in Biochar for Colonization by Fungal Hyphae From Soil

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Journal of Integrative Agriculture 2014年第3期13卷 483-490页

作者： Noraini M Jaafar Peta L Clode Lynette K Abbott Soil Biology and Molecular Ecology Group School of Earth and Environment and UWA Institute of Agriculture The University of Western Australia Department of Land Management Faculty of Agriculture Universiti Putra Malaysia Centre for microscopy Characterisation and Analysis The University of Western Australia

Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy （SEM） observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study.

关键词： biochar agriculture fungi soil habitable pore space microscopy

Near-infrared-II deep tissue fluorescence microscopy and application

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Nano Research 2023年第1期16卷 692-714页

作者： Pengfei Liu Rong Zhao Hongwei Li Tianyu Zhu Yuan Li Hao Wang Xiao-Dong Zhang Academy of Medical Engineering and Translational Medicine Medical CollegeTianjin UniversityTianjin 300072China Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology School of SciencesTianjin UniversityTianjin 300350China

Fluorescence imaging has become an essential tool in biomedical ***,non-invasive deep-tissue threedimensional optical in vivo imaging with the high spatiotemporal resolution is challenging due to the interaction between photons and *** shaping has been used to tailor microscopy techniques to enhance microscope *** nearinfrared window(NIR)between 700 and 1,700 nm,generally emphasized as the NIR-II(1,000–1,700 nm)window,has been developed into a promising bio-optical solution chosen as the lower interaction effect in this spectrum,showing potential in basic biological research and clinical *** this review,we summarize the existing methods to increase penetration depth and extensively describe biological microscopy techniques,NIR-II spectral windows,and *** to improve bioimaging performance and NIR-II imaging applications are *** on the current research achievements,we elucidate the main challenges and provide some recommendations and prospects for deep tissue penetration fluorescence for future biomedical applications.

关键词： deep tissue penetration microscopy near-infrared II imaging fluorophore

High-resolution Transmission Electron microscopy Characterization of the Structure of Cu Precipitate in a Thermal-aged Multicomponent Steel

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Chinese Journal of Mechanical Engineering 2019年第5期32卷 117-124页

作者： Lizhan Han Qingdong Liu Jianfeng Gu Institute of Materials Modification and Modelling School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai Jiao Tong UniversityShanghai 200240China

High-dispersed nanoscale Cu precipitates often contribute to extremely high strength due to precipitation hardening,and whereas usually lead to degraded toughness for especially ferritic ***,it is important to understand the formation behaviors of the Cu ***-resolution transmission electron microscopy(TEM)is utilized to investigate the structure of Cu precipitates thermally formed in a high-strength low-alloy(HSLA)*** Cu precipitates were generally formed from solid solution and at the crystallographic defects such as martensite lath boundaries and *** Cu precipitates in the same aging condition have various structure of BCC,9 R and FCC,and the structural evolution does not greatly correlate with the actual *** presence of different structures in an individual Cu precipitate is observed,which reflects the structural transformation occurring locally to relax the strain *** multiply additions in the steel possibly make the Cu precipitation more complex compared to the binary or the ternary Fe-Cu alloys with Ni or Mn *** research gives constructive suggestions on alloying design of Cu-bearing alloy steels.

关键词： Cu precipitate High-resolution transmission electron microscopy Thermal aging High-strength low-alloy steel

Resolution and contrast enhancement of laser-scanning multiphoton microscopy using thulium-doped upconversion nanoparticles

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Nano Research 2019年第12期12卷 2933-2940页

作者： Alexey B.Kostyuk Artem D.Vorotnov Andrey V.Ivanov Arthur B.Volovetskiy Aleksandr V.Kruglov Lyudmila M.Sencha Liuen Liang Evgenii L.Guryev Vladimir A.Vodeneev Sergey M.Deyev Yiqing Lu Andrei V.Zvyagin Lobachevsky State University of Nizhny Novgorod Nizhny Novgorod 603950Russia Center of Biomedical Engineering Institute of Molecular MedicineSechenov UniversityMoscow 119991Russia ARC Centre of Excellence"Nanoscale BioPhotonics" Department of Physics and AstronomyMacquarie UniversitySydney 2109Australia Institute ofBioorganic Chemistry Russian Academy of SciencesMoscow 117997Russia

High-contrast optical imagi ng is achievable using phosphoresce nt labels to suppress the short-lived background due to the optical backscatterand autofluoresce ***,the long-lived phosphorescence is generally incompatible with high-speed laser-scan ning imaging ***,we show that upc on versi on nan oparticles of structure NaYF4:Yb co-doped with 8%Tm(8T-UCNP)in combi nation with a commerciallaser-scanning multiphoton microscopy are uniquely suited for labeling biological systems to acquire high-resolution images with the enhancedcon *** comparison with many phosphoresce nt labels,the 8T-UCNP emission lifetime of-15μs affords rapid image ***-order optical nonlinearity of the 8T-UCNP(n=4,as confirmed experimentally and theoretically)afforded pushing the resolution limitattain able with UCNPs to the *** contrast enha nceme nt was achieved by suppressing the backgro und using(i)ban dpassspectral filtering of the narrow emission peak of 8T-UCNP at 455-nm,and(ii)time-gating implemented with a time-correlated single-photon counting system that demonstrated the contrast enhancement of>2.5-fold of polyethyle neimine-coated 8T-UCNPs take n up by huma nbreast adeno carcinoma cells *** a result,discrete 8T-UCNP nan oparticles became clearly observable in the freshly excised splee ntissue of laboratory mice 15-min post in trave nous injectio n of an 8T-UCNP *** dem on strated approach paves the way forhigh-contrast,high-resoluti on,and high-speed multiphot on microscopy in challe nging envir onments of i ntense autofluorescence,exogenous staining,and turbidity,as typically occur in intravital imaging.

关键词： upconversion nanoparticles autofluorescence time-gated imaging scanning microscopy time-correlated single photon counting

Assessment of oxide nanoparticle stability in liquid phase transmission electron microscopy

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Nano Research 2019年第9期12卷 2355-2363页

作者： Mark J. Meijerink Krijn P. de Jong Jovana Zecevic Inorganic Chemistry and Catalysis Debye Institute of Nanomaterials ScienceUtrecht UniversityUniversiteitsweg 993584 CG UtrechtThe Netherlands

Studying liquid phase nanoscale dynamic processes of oxide nanoparticles is of considerable interest to a wide variety of *** developed liquid phase transmission electron microscopy(LP-TEM)is a promising technique,but destabilization of oxides by solid-liquid?electron interactions remains an important *** this work we present a methodology to assess LP-TEM oxide stability in an aqueous phase,by subjecti ng several oxides of tech no logical importa nee to a controlled electr on dose in *** show a correlati on based on the Gibbs free en ergy of oxide hydrati on that can be used to assess the stability of oxides and dem on strate the existenee of several remarkably stable oxides,with no observable structural changes after one hour of electron beam irradiation in *** such destabilization phenomena combined with the identification of stable oxides allows for designing LP-TEM experiments free from adverse beam effects and thus in vestigati ons of numerous releva ntnano scale processes in water.

关键词： liquid phase transmission electron microscopy(LP-TEM) transmission electron microscopy electron beam damage metal oxide nano materials oxide stability

Advances in atomic force microscopy for single-cell analysis

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Nano Research 2019年第4期12卷 703-718页

作者： Mi Li Ning Xi Yuechao Wang Lianqing Liu State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang 110016 China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Shenyang 110016 China Department of Industrial and Manufacturing Systems Engineering The University of Hong Kong Hong Kong 999077 China

Single-cell analysis has been considered as a promising way to uncover the underlying mechanisms guiding the mysteries of life activities, which con siderably complements traditio nal en semble assays and yields novel in sights into cell biology. The adve nt of atomic force microscopy (AFM) provides a potent tool for investigati ng the structures and properties of n ative biological samples at the micro/na no scale un der near-physiological conditions, which promotes the studies of single-cell behaviors. In the past decades, AFM has achieved great success in single-cell observation and manipulation for biomedical applications, demonstrating the excellent capabilities of AFM in addressing biological issues at the single-cell level with unprecedented spatiotemporal resolution. In this article, we review the recent advances in single-cell analysis that has been made with the utilization of AFM, and provide perspectives for future progression.

关键词： atomic force microscopy single-cell analysis cellular morphology cellular mechanics cellular manipulation

Advances in nanomaterials for brain microscopy

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Nano Research 2018年第10期11卷 5144-5172页

作者： Jackson T. Del Bonis-O'Donnell Linda Chio Gabriel F. Dorlhiac lan R. McFarlane Markita P. Landry Department of Chemical and Biomolecular Engineering University of California Berkeley CA 94720 USA Biophysics Graduate Group University of California Berkeley CA 94720 USA Innovative Genomics Institute (IGI) Berkeley CA 94720 USA California Institute for Quantitative Biosciences QB3 University of California Berkeley CA 94720 USA Chan-Zuckerberg Biohub San Francisco CA 94158 USA

Microscopic imaging of the brain continues to reveal details of its structure, connectivity, and function. To further improve our understanding of the emergent properties and functions of neural circuits, we need to directly visualize the relationship between brain structure, neuron activity, and neurochemistry. Advances in the chemical and optical properties of nanomaterials, and developments in deep-tissue microscopy, may help to overcome the current challenges of in-vivo brain imaging, particularly when imaging the brain through optically-dense brain tissue, skull, and scalp. Developments in nanomaterials may enable the implementation of tunable chemical functionality for neurochemical targeting and sensing, and fluorescence stability for long-term imaging. In this review, we summarize the current methods used for brain microscopy and describe the diverse classes of nanomaterials recently offered as contrast agents and functional probes for microscopic optical imaging of the brain.

关键词： nanomaterials neuroscience imaging microscopy

Probing non-polarizable liquid/liquid interfaces using scanning ion conductance microscopy

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Science China Chemistry 2020年第3期63卷 411-418页

作者： Yaxiong Gu Ye Chen Yifan Dong Junjie Liu Xianhao Zhang Mingzhi Li Yuanhua Shao Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer *** this article,the microscopic structure of a non-polarizable water/nitrobenzene(W/NB)interface was evaluated by scanning ion conductance microscope(SICM).Using SICM with a nanometer-sized quartz pipette filled with an electrolyte solution as the probe,the thickness of this type of W/NB interface could be measured at sub-nanometer scale,based on the continuous change of ionic current from one phase to another *** effects for thicknesses of the non-polarizable W/NB interfaces with different electrolyte concentrations,the Galvani potentials at the interface and the applied potentials on the probe were measured and systematically *** experimental setups,that is an organic phase up and an aqueous down,and a reverse version,were employed to acquire the approach *** data were compared with those of an ideal polarizable interface under the similar experimental conditions,and several characteristics of non-polarizable interfaces were *** thickness of a non-polarizable interface increases with the decrease of electrolyte concentration and the increase of applied potential,which is similar to the situation of a polarizable liquid/liquid *** also find that the Galvani potential across a non-polarizable interface can also influence the interfacial thickness,this phenomenon is difficult to observe when using polarizable *** importantly,by the comparison of two kinds of liquid/liquid interfaces,we experimentally proved that much more excess ions are gathered in the space charge layer of non-polarizable interfaces than in that of polarizable *** results are consistent with the predictions of molecular dynamic simulations and X-ray reflectivity measurements.

关键词： micro/nano pipettes scanning ion conductance microscopy microstructure of a non-polarizable liquid/liquid interface

Development of a sample preparation approach to measure the size of nanoparticle aggregates by electron microscopy

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Particuology 2019年第4期17卷 49-57页

作者： Agnieszka Dudkiewicz Angela Lehner Qasim Chaudhry Kristian Molhave Guenter Allmaier Karen Tiede Alistair B.A. Boxall Peter Hofmann John Lewis The Food and Environment Research Agency Sand Hutton York Y041 1LZ UK Department of Environment The University of York Heslington York YO10 5DD UK National Centre for Food Manufacturing The University of Lincoln Holbeach PE12 7AG UK Research Group Bio- and Polymer Analysis Institute of Chemical Technologies and Analytics TU Wien (Vienna University of Technology) Getreidemarkt 9 A-1060 Vienna Austria University of Chester Parkgate Road Chester CH1 4BJ UK Department of Micro and Nanotechnology Technical University of Denmark DTU Bldg 345b Lyngby 2800 Denmark Research Centre for Global Food Security and Ecosystems University of Hohenheim Wollgrasweg 43 70155 Stuttgart Germany Department of Geoinformatics - Z.GIS University of Salzburg Schillerstr. 30 A-5020 Salzburg Austria

Electron microscopy (EM) is widely used for nanoparticle (NP) sizing. Following an initial assessment of two sample preparation protocols described in the current literature as"unperturbed", we found that neither could accurately measure the size of NPs featuring a broad size distribution, e.g., aggregates. Because many real-world NP samples consist of aggregates, this finding was of considerable concern. The data showed that the protocols introduced errors into the measurement by either inducing agglomeration artefacts or providing a skewed size distribution towards small particles (skewing artefact). The focus of this work was to develop and apply a mathematical refinement to correct the skewing artefact. This refinement provided a much improved agreement between EM and a reference methodology, when applied to the measurement of synthetic amorphous silica NPs. Further investigation, highlighted the influence of NP chemistry on the refinement. This study emphasised the urgent need for greater and more detailed consideration regarding the sample preparation of NP aggregates to routinely achieve accurate measurements by EM. This study also provided a novel refinement solution applicable to the size characterisation of silica and c让rate-coated gold NPs featuring broad size distributions. With further research, this approach could be extended to other NP types.

关键词： Nanoparticles Aggregates Measurement Electron microscopy Sample preparation Artefacts