- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis of amorphous carbon nanofibers on a surface of commercial polymers under the action of a high power ion beam of nanosecond duration
摘要： The irradiation of various commercial polymers (chlorinated polyvinyl chloride, polyvinyl chloride, polyvinyl alcohol, polymethyl methacrylate) by a high-power ion beam of nanosecond duration has been investigated. The amorphous carbon nanofibers formation was detected on the surface of low-cost commercial polymers (chlorinated polyvinyl chloride, polyvinyl chloride) containing a catalyst under the high power ion beam irradiation at room temperature. Various iron compounds (organic and inorganic) were used as catalytic additions. The electron microscopy (scanning and transmission) with an energy dispersive analyzer and Raman spectroscopy were used to investigate the morphologies and structure of irradiated polymers. Carbon nanofibers (CNFs) had a most probable diameter in the range 50-90 nm and a maximum length of up to 10 μm. The maximum CNFs growth rate was estimated as 160 μm/μs. A possible growth mechanism for CNFs is discussed.
关键词： electron microscopy,amorphous carbon nanofibers,catalytic additions,Raman spectroscopy,high-power ion beam,commercial polymers
更新于2025-09-04 15:30:14
-
[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Recent Advances in Digital Holographic Microscopy
摘要： In digital holographic microscopy (DHM) a hologram is captured in the image space provided by a microscope. The transfer of the phase and amplitude structure in the original sample to the hologram is in fact strongly affected by the use of the imaging microscope. A big research effort has been devoted to correct these distortions both by numerical and optical compensation. In this contribution, we present several proposals to improve the performance of classical DHM architectures by an a priori approach to compensate physically these perturbations. Experimental results are also presented to validate the proposed techniques.
关键词： holography,digital holographic microscopy,quantitative phase imaging
更新于2025-09-04 15:30:14
-
Electrochemical etching of lightweight nanotips for high quality-factor quartz tuning fork force sensor: atomic force microscopy applications
摘要： Commercially available quartz tuning forks (QTFs) can be transformed into self-sensing and actuating force sensors by micro-assembling a sharp tip on the apex of a tine. Mass of the tip is critical in determining the quality (Q)-factor of the sensor, therefore, fabrication of the lightweight nanotips is a precondition for high Q-factor QTF sensors. The work reports fabrication of very lightweight tungsten nanotips with a two-step electrochemical etching technique which can be used to develop high Q-factor QTF force sensor. First, a tungsten wire with protective coating at one end (1–2 mm) is etched with a trapezoidal waveform to form a lengthy (～2–5 mm) and slender (diameter ～10–40 μm) micro-needle. In the second step, sharp tip apex is fabricated with a direct current etching. High Q-factor (6600–8000) QTF force sensors have been developed with the fabricated nanotips. Atomic force microscope scanning of nano-grating and a triblock copolymer surface validates the scanning performance of the developed sensors.
关键词： quartz tuning fork,nanotips,atomic force microscopy,force sensor,electrochemical etching
更新于2025-09-04 15:30:14
-
Passive ultrasound aided acoustic resolution photoacoustic microscopy imaging for layered heterogeneous media
摘要： Photoacoustic imaging reconstructions usually assume a known speed-of-sound (SOS) distribution; however, in most cases, the SOS distribution is not revealed and is dif?cult to estimate from photoacoustic signals. In this paper, we propose passive ultrasound aided acoustic resolution photoacoustic microscopy which simultaneously reconstructs SOS distributions and photoacoustic images for layered heterogeneous media. The passive ultrasound is a kind of laser-induced acoustic wave generated by a transducer absorbing the backscattered light. It can be used to measure the layer thicknesses due to its sensitivity to structural information and broad bandwidth and further determine the SOS distributions. After estimating the SOS distributions, a phase shift plus interpo- lation is employed to reconstruct the photoacoustic image for heterogeneous media. Without intro- ducing additional hardware, this method can be conveniently incorporated into a conventional photoacoustic imaging system. A curved shell immersed in water is adopted as a layered heteroge- neous phantom, and the proposed method reconstructs the targets (carbon rods) under this shell. Under the test of a 5 MHz focused transducer (NA 0.25), the maximum reconstruction deviation of 1.2 mm carbon rods is only 0.15 mm.
关键词： passive ultrasound,speed-of-sound distribution,acoustic resolution photoacoustic microscopy,layered heterogeneous media,photoacoustic imaging
更新于2025-09-04 15:30:14
-
Choosing the right label for single-molecule tracking in live bacteria: side-by-side comparison of photoactivatable fluorescent protein and Halo tag dyes
摘要： Visualizing and quantifying molecular motion and interactions inside living cells provides crucial insight into the mechanisms underlying cell function. This has been achieved by super-resolution localization microscopy and single-molecule tracking in conjunction with photoactivatable fluorescent proteins (PA-FPs). An alternative labelling approach relies on genetically-encoded protein tags with cell-permeable fluorescent ligands which are brighter and less prone to photobleaching than fluorescent proteins but require a laborious labelling process. Either labelling method is associated with significant advantages and disadvantages that should be taken into consideration depending on the microscopy experiment planned. Here, we describe an optimised procedure for labelling Halo-tagged proteins in live Escherichia coli cells. We provide a side-by-side comparison of Halo tag with different fluorescent ligands against the popular photoactivatable fluorescent protein PAmCherry. Using test proteins with different intracellular dynamics, we evaluated fluorescence intensity, background, photostability, and results from single-molecule localization and tracking experiments. Capitalising on the brightness and extended spectral range of fluorescent Halo ligands, we also demonstrate high-speed and dual-colour single-molecule tracking.
关键词： Halo tag,single-molecule tracking,photoactivatable fluorescent protein,Escherichia coli,fluorophores,super-resolution microscopy,DNA-binding proteins
更新于2025-09-04 15:30:14
-
SENSING IMMOBILIZED MOLECULES OF STREPTAVIDIN ON A SILICON SURFACE BY MALDI-TOF MASS SPECTROMETRY AND FLUORESCENCE MICROSCOPY
摘要： A hydrogen-terminated Si (111) surface was modified to form an aminoterminated monolayer for immobilization of streptavidin. Cleavage of an N-(ω-undecylenyl)-phthalimide covered surface using hidrazine yields an amino group-modified surface, which serves as a substrate for the attachment of biotin and subsequently streptavidin. We used surface analytical techniques to characterize the surface and to control the course of functionalization before the immobilization of streptavidin. To confirm the presence of the streptavidin Texas red on the surface two powerful techniques available in a standard biochemical laboratory are used, Fluorescence Microscopy and MALDI-TOF that allow us to detect and determine the immobilized streptavidin. This work provides an avenue for the development of devices in which the exquisite binding specificity of biomolecular recognition is directly coupled to a biosensor. In addition, we have demonstrated that MALDI-TOF and fluorescence microscopy are useful techniques for the characterization of silicon functionalized surfaces.
关键词： streptavidin,fluorescence microscopy,MALDI-TOF,biosensor,silicon surface
更新于2025-09-04 15:30:14
-
[Methods in Molecular Biology] BCL-2 Family Proteins Volume 1877 (Methods and Protocols) || Rapid Imaging of BCL-2 Family Interactions in Live Cells Using FLIM-FRET
摘要： The Bcl-2 proteins control cell death via interchanging interactions within the Bcl-2 family. Fluorescence lifetime imaging microscopy (FLIM) is used to detect F?rster resonance energy transfer (FRET) between two fluorescent-fusion proteins in live cells. FLIM-FRET has been used to detect specific interactions and their disruption, for Bcl-2 family proteins. To date, this has been possible only in low throughput, due to the time required for serial data acquisition. We developed an automated optical system with eight parallel detectors for rapid and efficient data collection. Here we describe how to use this system for FLIM-FRET imaging of Bcl-2 family protein interactions in a 384-well plate format.
关键词： BH3 mimetic,FLIM Hyperspectral,FLIM-FRET,Bcl-2 family,mCerulean3,High throughput,Fluorescence lifetime imaging microscopy
更新于2025-09-04 15:30:14
-
Formation mechanism of twin domain boundary in 2D materials: The case for WTe2
摘要： Our scanning tunneling microscopy (STM) study observes, for the first time, twin domain boundary (TDB) formations on the surface of WTe2 single crystal, which is glued by solidifying indium to Si substrate. In these TDB regions, a large inhomogeneous strain field, especially a critical shear strain of about 7%, is observed by geometric phase analysis. This observation does not obey the old believe that a small mechanical stress is sufficient to drive thermally-induced TDB formations in two-dimensional materials. To resolve the contradiction, we perform density functional theory calculations combined with elasticity theory analysis, which show that TDBs on WTe2 are entirely displacement-induced, for which a critical strain is necessary to overcome the onset barrier.
关键词： WTe2,twin domain boundary,density functional theory,strain,scanning tunneling microscopy (STM)
更新于2025-09-04 15:30:14
-
Infrared microscopy in the study of cellular biochemistry
摘要： This is a personal overview of the background, motivation and objectives in the application of infrared spectromicroscopy techniques to the study of cellular biochemistry, as detailed in a presentation given at WIRMS2017. It was not the aim of the presentation, nor is it the aim of the present article, to be a systematic review of the field of biological IR microscopy. Rather, it highlights the motivation for the author to use IR microscopy in biological research, with an emphasis on experiments that address specific questions in biochemical and cellular research. It also comments on the role of conventional light sources and synchrotron radiation in these experiments and justifies the use of synchrotron light in their implementation. The synchrotron advantage for experiments on live cells is reassessed in view of recent developments in the technology of IR light sources, in particular the introduction of novel designs of mid-infrared lasers. Finally, future applications of synchrotron IR light to the field are discussed with respect to the introduction of near-field techniques for IR imaging and spectroscopy of cellular samples, such as sSNOM and AFM-IR.
关键词： Metabolism,Infrared microscopy,Tomography,Synchrotron radiation,Live cells
更新于2025-09-04 15:30:14
-
Enhanced Photoresponsive Graphene oxide-modified g-C3N4 for Disassembly of Amyloid β Fibrils
摘要： Protein misfolding and abnormal self-assembly lead to the aggregates of oligomer, fibrils, or senior amyloid β plaques, which is associated with the pathogenesis of many neurodegenerative diseases. Progressive cerebral accumulation of amyloid β-protein (Aβ) was widely proposed to explain the cause of Alzheimer's disease, for which one promising direction of preclinical study is to convert the pre-formed β-sheet structure of amyloid β aggregates into innocent structures. However, the conversion is even harder than the modulation of amyloidosis process. Herein, graphene oxide/carbon nitride (GO/g-C3N4) composite was developed as a good photocatalyst for irreversibly disassembling the amyloid β aggregates of Aβ (33-42) under UV. Quartz crystal microbalance, circular dichroism spectrum, atomic force microscopy, fluorescent spectra, and mechanical property analysis were performed to analyze this photo-degradation process from different aspects for fully understanding the mechanism, which may provide an important enlightenment for the relevant research in this field and neurodegenerative disease study.
关键词： Neurodegenerative disease,Amyloid β disassembly,Quartz crystal microbalance,Atomic force microscopy,Photo-degradation
更新于2025-09-04 15:30:14