Статті в журналах: "Probe structure"

1

Liu, Yifang, Ruimin Liu, Xiang Wang, Jiaxin Jiang, Wenwang Li, Juan Liu, Shumin Guo, and Gaofeng Zheng. "Electrospun Three-Dimensional Nanofibrous Structure via Probe Arrays Inducing." Micromachines 9, no. 9 (August 24, 2018): 427. http://dx.doi.org/10.3390/mi9090427.

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The fast and precise direct-printing of micro three-dimensional (3D) structures is the important development trend for micro/nano fabrication technique. A novel method with probe arrays was built up to realize the controllable deposition of 3D electrospun nanofibrous structures. Firstly, several 3D nanofibrous structures were built on a single probe and 2-, 3-probes, which indicated that the probe height and probe interval played a key role on the 3D structure morphology. Then, different stereo nanofibrous structures based on multiprobe arrays were achieved accurately and the effects of processing parameters, including the probe height, probe interval, applied voltage and flow rate on the deposition behaviors of electrospun nanofiber over the probe arrays were investigated. The deposition area of 3D electrospun nanofibrous structures decreased with the increase of probe interval, applied voltage, and flow rate. Several 3D nanofibrous structures of special shapes including convex, triangle wave, inverted cone and complex curved surface were demonstrated by controlling the configuration of probe arrays and electrospinning parameters. This work provides an effective and simple way for the construction of 3D electrospun nanofibrous structures, which has great potentials in various medical and industrial applications.

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2

Livanova, Nadezhda, Svetlana Karpova, and Gennady Zaikov. "The Structure of Acrylonitrile-Butadiene Rubbers: Paramagnetic-Probe Study." Chemistry & Chemical Technology 7, no. 1 (March 10, 2013): 69–72. http://dx.doi.org/10.23939/chcht07.01.069.

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3

Chen, Guolong, Zheng Cao, and Weimin Zhang. "A Novel Planar Differential Koch Fractal Eddy Current Probe with Parallel Wound Topological Structure." Journal of Sensors 2021 (June 16, 2021): 1–13. http://dx.doi.org/10.1155/2021/6671189.

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Flexible planar eddy current probes are widely used to detect conductive components with complex surface. In this study, topological transformation is applied to design a differential Koch coil exciting eddy current probe. Two kinds of Koch exciting coils, Koch A and Koch B , were obtained by topological transformation from a three-dimensional differential exciting eddy current probe. Finite element model simulation is conducted to visualize the differences of eddy current distributions induced by the probes and get the defect signal. A detailed comparison is made among the two kinds of Koch eddy current probes and a circular eddy current probe by experiments. The experiments demonstrate that the sensitivity of the Koch A eddy current probe is higher than that of another two probes for detecting the defect which is shorter than the size of the probe. This work provides a novel method for improving the performance of eddy current probes in the coil structure design.

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4

Kimoto, Gunsei, Takehiro Watanabe, Souta Matsusaka, Akio Inoue, and Takaharu Kuroda. "New Development of Contact Probe and Methodology." Advanced Materials Research 126-128 (August 2010): 726–31. http://dx.doi.org/10.4028/www.scientific.net/amr.126-128.726.

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We present a new type of wafer probe card with resin film consisting of two beams. Resin film is embedded on both sides of the probe beam, having a thickness of 4 [μm] and made from polyimide. This proposed probe enables compliant structures with large overdrive to ensure high durability of the structure and controllable scrub motion to assure cleaning process. In this study, Matrix method is introduced for theoretical studies of the probe structure and commercial finite element code is used. Electrical contact resistance is determined by theoretical studies based on Holm's theory and experimentally by our measurement instrumentation respectively. The structure is proven theoretically to get appropriate scrub motion when it undergoes a large overdrive with preferable exhibited contact force. Moreover, all of these mechanical characteristics can be varied to know the values of the character of probes. The methodology having one of the most preferable characters of the contact-probe had been achieved.

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5

Chandler, Darrell P., Gregory J. Newton, Jonathan A. Small, and Don S. Daly. "Sequence versus Structure for the Direct Detection of 16S rRNA on Planar Oligonucleotide Microarrays." Applied and Environmental Microbiology 69, no. 5 (May 2003): 2950–58. http://dx.doi.org/10.1128/aem.69.5.2950-2958.2003.

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ABSTRACT A two-probe proximal chaperone detection system consisting of a species-specific capture probe for the microarray and a labeled, proximal chaperone probe for detection was recently described for direct detection of intact rRNAs from environmental samples on oligonucleotide arrays. In this study, we investigated the physical spacing and nucleotide mismatch tolerance between capture and proximal chaperone detector probes that are required to achieve species-specific 16S rRNA detection for the dissimilatory metal and sulfate reducer 16S rRNAs. Microarray specificity was deduced by analyzing signal intensities across replicate microarrays with a statistical analysis-of-variance model that accommodates well-to-well and slide-to-slide variations in microarray signal intensity. Chaperone detector probes located in immediate proximity to the capture probe resulted in detectable, nonspecific binding of nontarget rRNA, presumably due to base-stacking effects. Species-specific rRNA detection was achieved by using a 22-nt capture probe and a 15-nt detector probe separated by 10 to 14 nt along the primary sequence. Chaperone detector probes with up to three mismatched nucleotides still resulted in species-specific capture of 16S rRNAs. There was no obvious relationship between position or number of mismatches and within- or between-genus hybridization specificity. From these results, we conclude that relieving secondary structure is of principal concern for the successful capture and detection of 16S rRNAs on planar surfaces but that the sequence of the capture probe is more important than relieving secondary structure for achieving specific hybridization.

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6

Zheng, Guanghua, Fei Shui, Jinxin Hu, Xin Liu, and Huazhong Xiao. "Effects of probes with different structures on the flow field and measurement results of imported compressors." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 39, no. 4 (August 2021): 858–64. http://dx.doi.org/10.1051/jnwpu/20213940858.

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In this paper, the measurement accuracy of two different types of total pressure probe and total temperature probe in turboshaft engine compressor inlet channel and the influence of these two probes on the flow field through numerical simulation was studied. At the same time, the influence of the probe structure and installation position on probe measurement results under three typical working conditions of cruise, maximum continuous and takeoff was analyzed. The simulation results showed that the higher the engine inlet flow rate, the greater the measurement error of the probe. Comparing with the total temperature probe, the total pressure probe measurement accuracy is more influenced by the flow rate. The velocity uniformity is less affected by the engine operating conditions and is mainly related to the structure of the inserted probes. The closer the total pressure probe to the support plate, the greater the measurement error. The probe installation position has a small effect on the total pressure loss coefficient at the outlet.

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7

AbdAlla, Ahmed N., Moneer A. Faraj, Fahmi Samsuri, Damhuji Rifai, Kharudin Ali, and Y. Al-Douri. "Challenges in improving the performance of eddy current testing: Review." Measurement and Control 52, no. 1-2 (November 16, 2018): 46–64. http://dx.doi.org/10.1177/0020294018801382.

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Eddy current testing plays an important role in numerous industries, particularly in material coating, nuclear and oil and gas. However, the eddy current testing technique still needs to focus on the details of probe structure and its application. This paper presents an overview of eddy current testing technique and the probe structure design factors that affect the accuracy of crack detection. The first part focuses on the development of different types of eddy current testing probes and their advantages and disadvantages. A review of previous studies that examined testing samples, eddy current testing probe structures and a review of factors contributing to eddy current signals is also presented. The second part mainly comprised an in-depth discussion of the lift-off effect with particular consideration of ensuring that defects are correctly measured, and the eddy current testing probes are optimized. Finally, a comprehensive review of previous studies on the application of intelligent eddy current testing crack detection in non destructive eddy current testing is presented.

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8

Luc Le, Xuan, Han Eul Lee, and Sung-Hoon Choa. "Deformation Behavior of Various Interconnection Structures Using Fine Pitch Microelectromechanical Systems (MEMS) Vertical Probe." Journal of Nanoscience and Nanotechnology 21, no. 5 (May 1, 2021): 2949–58. http://dx.doi.org/10.1166/jnn.2021.19132.

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Recently, fine pitch wafer level packaging (WLP) technologies have drawn a great attention in the semiconductor industries. WLP technology uses various interconnection structures including microbumps and through-silicon-vias (TSVs). To increase yield and reduce cost, there is an increasing demand for wafer level testing. Contact behavior between probe and interconnection structure is a very important factor affecting the reliability and performance of wafer testing. In this study, with a MEMS vertical probe, we performed systematic numerical analysis of the deformation behavior of various interconnection structures, including solder bump, copper (Cu) pillar bump, solder capper Cu bump, and TSV. During probing, the solder ball showed the largest deformation. The Cu pillar bump also exhibited relatively large deformation. The Cu bump began to deform at OD of 10 μm. At OD of 20 μm, bump pillar was compressed, and the height of the bump decreased by 8.3%. The deformation behavior of the solder capped Cu bump was similar to that of the solder ball. At OD of 20 μm, the solder and Cu bumps were largely deformed, and the total height was reduced by 11%. The TSV structure showed the lowest deformation, but exerted the largest stress on the probe. In particular, copper protrusion at the outer edge of the via was observed, and very large shear stress was generated between the via and the silicon oxide layer. In summary, when probing various interconnection structures, the probe stress is less than that when using an aluminum pad. On the other hand, deformation of the structure is a critical issue. In order to minimize damage to the interconnection structure, smaller size probes or less overdrive should be used. This study will provide important guidelines for performing wafer-level testing and minimizing damage of probes and interconnection structures.

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9

Yanagisawa, Keisuke, Ryunosuke Yoshino, Genki Kudo, and Takatsugu Hirokawa. "Inverse Mixed-Solvent Molecular Dynamics for Visualization of the Residue Interaction Profile of Molecular Probes." International Journal of Molecular Sciences 23, no. 9 (April 26, 2022): 4749. http://dx.doi.org/10.3390/ijms23094749.

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To ensure efficiency in discovery and development, the application of computational technology is essential. Although virtual screening techniques are widely applied in the early stages of drug discovery research, the computational methods used in lead optimization to improve activity and reduce the toxicity of compounds are still evolving. In this study, we propose a method to construct the residue interaction profile of the chemical structure used in the lead optimization by performing “inverse” mixed-solvent molecular dynamics (MSMD) simulation. Contrary to constructing a protein-based, atom interaction profile, we constructed a probe-based, protein residue interaction profile using MSMD trajectories. It provides us the profile of the preferred protein environments of probes without co-crystallized structures. We assessed the method using three probes: benzamidine, catechol, and benzene. As a result, the residue interaction profile of each probe obtained by MSMD was a reasonable physicochemical description of the general non-covalent interaction. Moreover, comparison with the X-ray structure containing each probe as a ligand shows that the map of the interaction profile matches the arrangement of amino acid residues in the X-ray structure.

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10

Yanagisawa, Keisuke, Ryunosuke Yoshino, Genki Kudo, and Takatsugu Hirokawa. "Inverse Mixed-Solvent Molecular Dynamics for Visualization of the Residue Interaction Profile of Molecular Probes." International Journal of Molecular Sciences 23, no. 9 (April 26, 2022): 4749. http://dx.doi.org/10.3390/ijms23094749.

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To ensure efficiency in discovery and development, the application of computational technology is essential. Although virtual screening techniques are widely applied in the early stages of drug discovery research, the computational methods used in lead optimization to improve activity and reduce the toxicity of compounds are still evolving. In this study, we propose a method to construct the residue interaction profile of the chemical structure used in the lead optimization by performing “inverse” mixed-solvent molecular dynamics (MSMD) simulation. Contrary to constructing a protein-based, atom interaction profile, we constructed a probe-based, protein residue interaction profile using MSMD trajectories. It provides us the profile of the preferred protein environments of probes without co-crystallized structures. We assessed the method using three probes: benzamidine, catechol, and benzene. As a result, the residue interaction profile of each probe obtained by MSMD was a reasonable physicochemical description of the general non-covalent interaction. Moreover, comparison with the X-ray structure containing each probe as a ligand shows that the map of the interaction profile matches the arrangement of amino acid residues in the X-ray structure.

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11

Ma, Jin-Liang, Bin-Cheng Yin, and Bang-Ce Ye. "A versatile proximity-dependent probe based on light-up DNA-scaffolded silver nanoclusters." Analyst 141, no. 4 (2016): 1301–6. http://dx.doi.org/10.1039/c5an02446c.

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It is well-known that proximity-dependent probes containing an analyte recognization site and a signal formation domain could be assembled specifically into a sandwich-like structure (probe–analyte–probe) via introducing an analyte.

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12

Dominy, R. G., and H. P. Hodson. "An Investigation of Factors Influencing the Calibration of Five-Hole Probes for Three-Dimensional Flow Measurements." Journal of Turbomachinery 115, no. 3 (July 1, 1993): 513–19. http://dx.doi.org/10.1115/1.2929281.

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The effects of Reynolds number, Mach number, and turbulence on the calibrations of commonly used types of five-hole probe are discussed. The majority of the probes were calibrated at the exit from a transonic nozzle over a range of Reynolds numbers (7 × 103 < Re < 80 × 103 based on probe tip diameter) at subsonic and transonic Mach numbers. Additional information relating to the flow structure were obtained from a large-scale, low-speed wind tunnel. The results confirmed the existence of two distinct Reynolds number effects. Flow separation around the probe head affects the calibrations at relatively low Reynolds numbers while changes in the detailed structure of the flow around the sensing holes affects the calibrations even when the probe is nulled. Compressibility is shown to have little influence upon the general behavior of these probes in terms of Reynolds number sensitivity but turbulence can affect the reliability of probe calibrations at typical test Reynolds numbers.

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13

YANG, Xiao-Qiu, Xiao-Bin SHI, He-Hua XU, Xing XU, Guan-Bao LI, Xing-Wei GUO, and Xian-Hu LUO. "Optimizing Probe Structure for Dual-Probe Seafloor Heat Flow Meter." Chinese Journal of Geophysics 52, no. 3 (May 2009): 615–24. http://dx.doi.org/10.1002/cjg2.1383.

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14

Hira, Jonathan, Md Jalal Uddin, Marius M. Haugland, and Christian S. Lentz. "From Differential Stains to Next Generation Physiology: Chemical Probes to Visualize Bacterial Cell Structure and Physiology." Molecules 25, no. 21 (October 26, 2020): 4949. http://dx.doi.org/10.3390/molecules25214949.

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Chemical probes have been instrumental in microbiology since its birth as a discipline in the 19th century when chemical dyes were used to visualize structural features of bacterial cells for the first time. In this review article we will illustrate the evolving design of chemical probes in modern chemical biology and their diverse applications in bacterial imaging and phenotypic analysis. We will introduce and discuss a variety of different probe types including fluorogenic substrates and activity-based probes that visualize metabolic and specific enzyme activities, metabolic labeling strategies to visualize structural features of bacterial cells, antibiotic-based probes as well as fluorescent conjugates to probe biomolecular uptake pathways.

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15

Sghir, Abdelghani, Genevieve Gramet, Antonia Suau, Violaine Rochet, Philippe Pochart, and Joel Dore. "Quantification of Bacterial Groups within Human Fecal Flora by Oligonucleotide Probe Hybridization." Applied and Environmental Microbiology 66, no. 5 (May 1, 2000): 2263–66. http://dx.doi.org/10.1128/aem.66.5.2263-2266.2000.

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ABSTRACT To investigate the population structure of the predominant phylogenetic groups within the human adult fecal microbiota, a new oligonucleotide probe designated S-G-Clept-1240-a-A-18 was designed, validated, and used with a set of five 16S rRNA-targeted oligonucleotide probes. Application of the six probes to fecal samples from 27 human adults showed additivity of 70% of the total 16S rRNA detected by the bacterial domain probe. The Bacteroidesgroup-specific probe accounted for 37% ± 16% of the total rRNA, while the enteric group probe accounted for less than 1%.Clostridium leptum subgroup and Clostridium coccoides group-specific probes accounted for 16% ± 7% and 14% ± 6%, respectively, while Bifidobacterium andLactobacillus groups made up less than 2%.

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16

Moloni, Katerina. "The Moving Finger Writes: Carbon Nanotubes as AFM Probe Tips." Microscopy Today 12, no. 1 (January 2004): 34–37. http://dx.doi.org/10.1017/s1551929500051804.

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After carbon nanotubes (CNT) were discovered in 1991, many applications have been proposed that utilize their extraordinary electrical and mechanical properties. One application is as tips for scanning probe microscopy where CNTs offer several advantages including high resolution and the capability to image deep, narrow structures. A recent study of CNT scanning probes for atomic force microscopy (AFM) in semiconductor surface science concluded that an AFM with CNT tips has immense potential as a surface characterization tool in integrated circuit manufacture. Previously researchers had to construct their own CNT probes, but recently CNT AFM probes have become commercially available.Carbon nanotubes (sometimes called buckytubes) are closed seamless shells ot graphitic carbon typically one to tens of nanometers in diameter and several micrometers long. The structure of a closed-dome single-walled nanotube is illustrated in Figure 1. Carbon nanotube probe tips offer several advantages.

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17

Szelecka, Agnieszka, Maciej Jakubczak, and Jacek Kurzyna. "Plasma beam structure diagnostics in krypton Hall thruster." Laser and Particle Beams 36, no. 2 (June 2018): 219–25. http://dx.doi.org/10.1017/s0263034618000198.

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AbstractKrypton Large Impulse Thruster (KLIMT) project was aimed at incremental development and optimization of a 0.5 kW-class plasma Hall Effect Thruster in which, as a propellant, krypton could be used. The final thermally stable version of the thruster (the third one) was tested in the Plasma Propulsion Satellites (PlaNS) laboratory in the Institute of Plasma Physics and Laser Microfusion (IPPLM) in Warsaw as well as in the European Space Agency (ESA) propulsion laboratory in the European Space Research and Technology Centre (ESTEC).During final measurement campaign, a wide spectrum of parameters was tested. The plasma potential, electron temperature, electron concentration, and electron energy probability function in the far-field plume of the thruster were measured with a single cylindrical Langmuir probe. Faraday probes were used for recording local values of ion current. Using several collectors in different locations and moving them on the surface of a sphere, the angular distribution of the expelled particles was reconstructed which was a local measure of beam divergence. Angular distribution of ion flux as measured with a central Faraday probe was parameterized with krypton mass flow rate, voltage, coil current ratio, and the cathode mass flow rate. Beam divergence measurements with Faraday probes as well as plasma parameters derived from Langmuir probe seem to be consistent with our understanding of the operating envelope. Obtained results will serve as a baseline in the design of plasma beam structure diagnostics system for the PlaNS laboratory.

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18

Zhang, Lan, Yang Ju, Atsushi Hosoi, and Akifumi Fujimoto. "Enhancement of Sensitivity for the Evaluation of Electrical Properties by Modifying the Nano Structure of Microwave AFM Probe." Materials Science Forum 675-677 (February 2011): 555–58. http://dx.doi.org/10.4028/www.scientific.net/msf.675-677.555.

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To confirm the sensitivity in the measurement of electrical properties affected by the nano structure of microwave AFM (M-AFM) probe, three kinds of M-AFM probe with a nano-slit on its tip in different width (75 nm, 120 nm and 160 nm) were investigated. Au and glass samples were measured by the probes working at a non-contact AFM mode. The M-AFM probe with the nano-slit having the width of 75 nm, by which the difference of the measured voltage between Au and glass samples is 55.1 mV, shows the highest sensitivity for detecting electrical properties of materials. As the result illustrated, the M-AFM probe with smaller width nano-slit on the tip can be considered to be an ideal nano structure.

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19

Guidi, Stefano, and Stephen E. Palmer. "The Internal Structure of a Rectangular Frame: Position, Orientation, and Direction." Art & Perception 3, no. 1 (2015): 19–52. http://dx.doi.org/10.1163/22134913-00002013.

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Previous research has shown that the structure of a rectangular frame strongly influences perceived goodness-of-fit for a small circular probe positioned within it (Palmer and Guidi, 2011). The center is consistently rated as the best position, followed by positions along the global vertical, global horizontal, and local diagonal symmetry axes. Here we report how goodness-of-fit within a surrounding frame is influenced by the relation between with the orientational and directional structure of the probe and that of the frame. In Experiment 1, fit ratings of short line segments and small ovals (each with two symmetry axes) at 35 positions and four orientations within the frame revealed strong orientational effects, especially when the probe’s and frame’s axes of symmetry were aligned. Experiment 2 extended the paradigm using triangular probes (with a single symmetry axis) at 15 positions and eight pointing directions. The results showed high fit ratings when the probe was aligned with global and local symmetry axes of the frame, and directional increments when the probes pointed upward, rightward, and into the frame. Experiment 3 confirmed the upward, rightward, and inward directional effects of Experiment 2 using a more sensitive Two-Alternative Forced Choice (2AFC) task. Experiment 4 showed that orientational effects were more strongly driven by alignment with the rectangle’s sides than with gravitational or retinal reference frames, especially when the probe was near the sides and vertices of the frame. The relevance of these findings to the empirical study of aesthetic response to images within rectangular frames is discussed.

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20

Dimitrijević, Tijana, Aleksandar Atanaskovic, Nebojša S. Dončov, David W. P. Thomas, Christopher Smartt, and Mohd Hafiz Baharuddin. "Calibration of the loop probe for the near-field measurement." International Journal of Microwave and Wireless Technologies 12, no. 9 (June 1, 2020): 878–84. http://dx.doi.org/10.1017/s1759078720000690.

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AbstractAccurate near-field measurements for either deterministic or stochastic electromagnetic fields characterization require a relevant process that removes the influence of the probes, transmission lines, and measurement circuits. The main part of the experimental work presented here is related to a calibration procedure of a test setup consisting of a microstrip test structure and a scanning loop probe. The calibration characteristic, obtained by comparing measured and simulated results, is then used to convert the measured voltage into the magnetic field across and along the microstrip line at the specific height above it. By performing the measurements and simulations of the same test structure with the loop probe in the presence of an additional scanning probe, the influence of the additional probe to the measured output is thoroughly investigated and relevant corrections are given. These corrections can be important when two-point correlation measurement is required, especially in scanning points when two probes are mutually close.

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21

Kim, Young Joo, Bong Young Ahn, Ki Bok Kim, and Young Gil Kim. "Multi-Coil Eddy Current Probe for the Detection of Circumferential Cracks in Tubing." Key Engineering Materials 321-323 (October 2006): 505–8. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.505.

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Conventional eddy current bobbin probes, multi-pancake and/or rotating pancake probes, and transmit-receive eddy current probes are currently utilized in testing metal tubing. Each method has respective strengths and weaknesses. This paper proposes another eddy current probe with new features. The structure is designed to be sensitive to circumferential cracks, which are not easily detected with ordinary bobbin coil probes. The directions of the magnetic field and the eddy current around the coil were considered in design of the probe structure. Signals of these probes from the artificial defects were acquired and analyzed. Experimental results show that the developed probes are more sensitive to circumferential defects than comparable ordinary bobbin probes. In addition, the new probes are insensitive to axial defects. By employing both the new probes and ordinary bobbin probes, more reliable ECT can be performed.

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22

Armendariz, Kevin P., Heath A. Huckabay, Philip W. Livanec, and Robert C. Dunn. "Single molecule probes of membrane structure: Orientation of BODIPY probes in DPPC as a function of probe structure." Analyst 137, no. 6 (2012): 1402. http://dx.doi.org/10.1039/c2an16255e.

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23

Spychalski, Maciej, E. Fortuna-Zalesna, Joanna Zdunek, Marek Rubel, Anna Widdowson, Spyridon Aleiferis, and Beth Thomas. "Tungsten Langmuir probes from JET-with the ITER-Like Wall: Assessment of mechanical properties by nano-indentation." Physica Scripta 96, no. 12 (December 1, 2021): 124072. http://dx.doi.org/10.1088/1402-4896/ac3dbb.

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Abstract Tungsten Langmuir probes retrieved from the JET tokamak with the ITER-Like Wall (JET-ILW) after the second ILW campaign were examined by nano-indentation, microscopy and x-ray diffraction in order to determine changes in mechanical properties and phase composition. Not-exposed probe served as a reference material. Two regions were studied: (i) recrystallized region below the tip and, (ii) the lower probe structure, called ‘support structure’. A large difference between the hardness in the tip and the other region has been found: 5 GPa versus 15 GPa, respectively. The measured values of the Young’s modulus in both zones of exposed probe are at the same level of 260 GPa. From the force-displacement curves, it can be concluded that the material in the tip has a smaller range of elastic deformations compared to that characteristic for the support structure. The values obtained for the material in its initial state are consistent with the available literature data for tungsten. With x-ray diffraction and microscopy only tungsten has been detected in the probe tip. It remained clean and free from impurities and undesirable compounds, which could have a negative impact on the probes electrical properties.

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24

Wen, Jianguo, James Mabon, Changhui Lei, Steve Burdin, Ernie Sammann, Ivan Petrov, Amish B. Shah, et al. "The Formation and Utility of Sub-Angstrom to Nanometer-Sized Electron Probes in the Aberration-Corrected Transmission Electron Microscope at the University of Illinois." Microscopy and Microanalysis 16, no. 2 (February 26, 2010): 183–93. http://dx.doi.org/10.1017/s1431927610000085.

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AbstractWe evaluate the probe forming capability of a JEOL 2200FS transmission electron microscope equipped with a spherical aberration (Cs) probe corrector. The achievement of a real space sub-Angstrom (0.1 nm) probe for scanning transmission electron microscopy (STEM) imaging is demonstrated by acquisition and modeling of high-angle annular dark-field STEM images. We show that by optimizing the illumination system, large probe currents and large collection angles for electron energy loss spectroscopy (EELS) can be combined to yield EELS fine structure data spatially resolved to the atomic scale. We demonstrate the probe forming flexibility provided by the additional lenses in the probe corrector in several ways, including the formation of nanometer-sized parallel beams for nanoarea electron diffraction, and the formation of focused probes for convergent beam electron diffraction with a range of convergence angles. The different probes that can be formed using the probe corrected STEM opens up new applications for electron microscopy and diffraction.

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25

Carbotte, J. P., and E. Schachinger. "Optical conductivity to probe boson structure." Annalen der Physik 15, no. 7-8 (July 3, 2006): 585–95. http://dx.doi.org/10.1002/andp.200510195.

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26

Varnava, Christiana. "A deeper probe of electronic structure." Nature Electronics 1, no. 1 (January 2018): 3. http://dx.doi.org/10.1038/s41928-017-0017-5.

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Wen, Bo, Sho Sekine, Shinichi Osawa, Yuki Shimizu, Hiraku Matsukuma, Andreas Archenti, and Wei Gao. "A Comparison of the Probes with a Cantilever Beam and a Double-Sided Beam in the Tool Edge Profiler for On-Machine Measurement of a Precision Cutting Tool." Machines 9, no. 11 (November 6, 2021): 271. http://dx.doi.org/10.3390/machines9110271.

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This paper describes a comparison of the mechanical structures (a double-sided beam and a cantilever beam) of a probe in a tool edge profiler for the measurement of a micro-cutting tool. The tool edge profiler consists of a positioning unit having a pair of one-axis DC servo motor stages and a probe unit having a laser displacement sensor and a probe composed of a stylus and a mechanical beam; on-machine measurement of a tool cutting edge can be conducted with a low contact force through measuring the deformation of the probe by the laser displacement sensor while monitoring the tool position. Meanwhile, the mechanical structure of the probe could affect the performance of measurement of the edge profile of a precision cutting tool. In this paper, the measurement principle of the tool edge profile is firstly introduced; after that, slopes and a top-flat of a cutting tool sample are measured by using a cantilever-type probe and a double-sided beam-type probe, respectively. The measurement performances of the two probes are compared through experiments and theoretical measurement uncertainty analysis.

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28

Metfies, Katja, and Linda K. Medlin. "Feasibility of Transferring Fluorescent In Situ Hybridization Probes to an 18S rRNA Gene Phylochip and Mapping of Signal Intensities." Applied and Environmental Microbiology 74, no. 9 (March 7, 2008): 2814–21. http://dx.doi.org/10.1128/aem.02122-07.

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ABSTRACT DNA microarray technology offers the possibility to analyze microbial communities without cultivation, thus benefiting biodiversity studies. We developed a DNA phylochip to assess phytoplankton diversity and transferred 18S rRNA probes from dot blot or fluorescent in situ hybridization (FISH) analyses to a microarray format. Similar studies with 16S rRNA probes have been done determined that in order to achieve a signal on the microarray, the 16S rRNA molecule had to be fragmented, or PCR amplicons had to be <150 bp in length to minimize the formation of a secondary structure in the molecule so that the probe could bind to the target site. We found different results with the 18S rRNA molecule. Four out of 12 FISH probes exhibited false-negative signals on the microarray; eight exhibited strong but variable signals using full-length 18S RNA molecules. A systematic investigation of the probe's accessibility to the 18S rRNA gene was made using Prymenisum parvum as the target. Fourteen additional probes identical to this target covered the regions not tested with existing FISH probes. Probes with a binding site in the first 900 bp of the gene generated positive signals. Six out of nine probes binding in the last 900 bp of the gene produced no signal. Our results suggest that although secondary structure affected probe binding, the effect is not the same for the 18S rRNA gene and the 16S rRNA gene. For the 16S rRNA gene, the secondary structure is stronger in the first half of the molecule, whereas in the 18S rRNA gene, the last half of the molecule is critical. Probe-binding sites within 18S rRNA gene molecules are important for the probe design for DNA phylochips because signal intensity appears to be correlated with the secondary structure at the binding site in this molecule. If probes are designed from the first half of the 18S rRNA molecule, then full-length 18S rRNA molecules can be used in the hybridization on the chip, avoiding the fragmentation and the necessity for the short PCR amplicons that are associated with using the 16S rRNA molecule. Thus, the 18S rRNA molecule is a more attractive molecule for use in environmental studies where some level of quantification is desired. Target size was a minor problem, whereas for 16S rRNA molecules target size rather than probe site was important.

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29

Crawford, Conor J., Radamés J. B. Cordero, Lorenzo Guazzelli, Maggie P. Wear, Anthony Bowen, Stefan Oscarson, and Arturo Casadevall. "Exploring Cryptococcus neoformans capsule structure and assembly with a hydroxylamine-armed fluorescent probe." Journal of Biological Chemistry 295, no. 13 (January 31, 2020): 4327–40. http://dx.doi.org/10.1074/jbc.ra119.012251.

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Chemical biology is an emerging field that enables the study and manipulation of biological systems with probes whose reactivities provide structural insights. The opportunistic fungal pathogen Cryptococcus neoformans possesses a polysaccharide capsule that is a major virulence factor, but is challenging to study. We report here the synthesis of a hydroxylamine-armed fluorescent probe that reacts with reducing glycans and its application to study the architecture of the C. neoformans capsule under a variety of conditions. The probe signal localized intracellularly and at the cell wall–membrane interface, implying the presence of reducing-end glycans at this location where the capsule is attached to the cell body. In contrast, no fluorescence signal was detected in the capsule body. We observed vesicle-like structures containing the reducing-end probe, both intra- and extracellularly, consistent with the importance of vesicles in capsular assembly. Disrupting the capsule with DMSO, ultrasound, or mechanical shear stress resulted in capsule alterations that affected the binding of the probe, as reducing ends were exposed and cell membrane integrity was compromised. Unlike the polysaccharides in the assembled capsule, isolated exopolysaccharides contained reducing ends. The reactivity of the hydroxylamine-armed fluorescent probe suggests a model for capsule assembly whereby reducing ends localize to the cell wall surface, supporting previous findings suggesting that this is an initiation point for capsular assembly. We propose that chemical biology is a promising approach for studying the C. neoformans capsule and its associated polysaccharides to unravel their roles in fungal virulence.

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30

Zhang, Si Quan, Yu Liu, Hao Jun Xu, and Chang Yin. "Eddy Current Testing Probe to Improve the Defect Detection Sensitivity of Metal Tube." Advanced Materials Research 945-949 (June 2014): 1987–90. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.1987.

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The structure of conventional bobbin probe was modified to improve the detection sensitivity of defects in metal tube. Based on the results of finite element simulation, several types of modified probes are fabricated and used to detect artificial defects in tube and the defect signals are acquired and analyzed. The simulation and experimental results verified that the modified eddy current probes are more sensitive to non-axial defects than conventional bobbin probe and can improve the reliability of tube inspection.

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31

Dehoff, Robert T. "PROBES, POPULATIONS, SAMPLES, MEASUREMENTS AND RELATIONS IN STEREOLOGY." Image Analysis & Stereology 19, no. 1 (May 3, 2011): 1. http://dx.doi.org/10.5566/ias.v19.p1-8.

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This summary paper provides an overview of the content of stereology. The typical problem at hand centers around some three dimensional object that has an internal structure that determines its function, performance, or response. To understand and quantify the geometry of that structure it is necessary to probe it with geometric entities: points, lines, planes volumes, etc. Meaningful results are obtained only if the set of probes chosen for use in the assessment is drawn uniformly from the population of such probes for the structure as a whole. This requires an understanding of the population of each kind of probe. Interaction of the probes with the structure produce geometric events which are the focus of stereological measurements. In almost all applications the measurement that is made is a simple count of the number of these events. Rigorous application of these requirements for sample design produce unbiased estimates of geometric properties of features in the structure no matter how complex are the features or what their arrangement in space. It is this assumption-free characteristic of the methodology that makes it a powerful tool for characterizing the internal structure of three dimensional objects.

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32

Laakso, H., T. L. Aggson, and R. F. Pfaff. "Plasma gradient effects on double-probe measurements in the magnetosphere." Annales Geophysicae 13, no. 2 (February 28, 1995): 130–46. http://dx.doi.org/10.1007/s00585-995-0130-z.

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Abstract. The effects on double-probe electric field measurements induced by electron density and temperature gradients are investigated. We show that on some occasions such gradients may lead to marked spurious electric fields if the probes are assumed to lie at the same probe potential with respect to the plasma. The use of a proper bias current will decrease the magnitude of such an error. When the probes are near the plasma potential, the magnitude of these error signals, ∆E, can vary as ∆E ~ Te(∆ne/ne)+0.5∆Te, where Te is the electron temperature, ∆ne/ne the relative electron density variation between the two sensors, and ∆Te the electron temperature difference between the two sensors. This not only implies that the error signals will increase linearly with the density variations but also that such signatures grow with Te, i.e., such effects are 10 times larger in a 10-eV plasma than in a 1-eV plasma. This type of error is independent of the probe separation distance provided the gradient scale length is much larger than this distance. The largest errors occur when the probes are near to the plasma potential. At larger positive probe potentials with respect to the plasma potential, the error becomes smaller if the probes are biased, as is usually the case with spherical double-probe experiments in the tenuous magnetospheric plasmas. The crossing of a plasma boundary (like the plasmapause or magnetopause) yields an error signal of a single peak. During the crossing of a small structure (e.g., a double layer) the error signal appears as a bipolar signature. Our analysis shows that errors in double-probe measurements caused by plasma gradients are not significant at large scale (»1 km) plasma boundaries, and may only be important in cases where small-scale (<1 km), internal gradient structures exist. Bias currents tailored for each plasma parameter regime (i.e., variable bias current) would o1q1improve the double-probe response to gradient effects considerably.

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33

Ogura, Ichiro, and Yuichi Okazaki. "Development of Micro Probe System for Micro Measurement Center." International Journal of Automation Technology 3, no. 4 (July 5, 2009): 471–77. http://dx.doi.org/10.20965/ijat.2009.p0471.

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We developed two types of contact probe for micromeasurement. The first type -a dynamic motion probe with a probe ball 200μm in diameter- is driven in a circle by piezoelectric (PZT) actuators at a radius of 3μm and frequency of 10 Hz. The signal noise ratio indicates that the probe’s angle resolution is 1° and contact detection resolution of 50 nm. The second type of contact probe is static and developed for compact design. In addition to having a structure similar to earlier probes developed with a crossbeam plate, this one has a measurement ball glued to the front and back of the center plate. Optical sensors measure ball movement, which is synchronized with the contact probe. Basic experiments confirmed that the new probe has a measurement resolution of 50 nm.

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34

Yu, Jing, Yan-ling Yang, Jin-hui Cai, and Dong-sheng Li. "Coupling error model for the contact probe of a three-dimensional screw thread-measuring machine." Measurement Science and Technology 33, no. 5 (February 16, 2022): 055012. http://dx.doi.org/10.1088/1361-6501/ac4c0e.

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Abstract Coupling error is an important factor that affects the measurement accuracy of the contact scanning probe of a three-dimensional thread-measuring machine. To address this issue, this paper proposes a coupling error model for contact scanning probes. First, the mechanical structure of the contact scanning probe was introduced, and the main source of its coupling error was analyzed. Second, material mechanics was used to conduct a geometry–force analysis on the guiding mechanism of the probe, thereby establishing a coupling error model. Finally, the experiments were carried out to verify the accuracy of the coupling error model. From the experimental verification, the movement of the measuring head by 10 μm increased the deviation of the probe displacement by 2 μm, indicating the probe deflection. Moreover, the calculated probe deflection angle was consistent with the theoretical value, validating the proposed coupling error model. This method provides an important theoretical basis for the decoupling of measuring probe, thereby improving the accuracy of the probe guiding mechanism.

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35

Chathirat, Naphat, Charndet Hruanun, and Amporn Poyai. "DNA Biosensor on Optical Nanograting Structure." Applied Mechanics and Materials 804 (October 2015): 199–202. http://dx.doi.org/10.4028/www.scientific.net/amm.804.199.

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We present a nanograting optical biosensor device, fabricated by photolithography, which is sensitive to changes in refractive index at the sensor surface. via changes in the reflectivity spectra. The grating was created by etching of a silicon nitride (Si3N4) film, which has a refractive index of 2.01, resulting in an array of Si3N4 pillars. The grating was coated by the high quality spin on glass material which has a low effective refractive index <1.50. The surface was functionalised with a layer of probe biomolecules for specific binding of the target DNA. Immobilization of the probe molecules was carried out via streptavidin – biotin interaction, the biotin modified ssDNA oligonucleotide probes were 23 bases in length (1010 copies/μl) and the sequence of the complementary ssDNA was 5’-TAC TCA TAC TTG AGG TTG AAA TT-3’(10, 100 and 1000 copies/μl). Results of the experiment showed that when molecules attached to the surface of the device, the position of the reflectance spectrum shifted due to the change of the optical path of light that is coupled into the nanograting structure. The extent of the wavelength shift (Δλ) of the peaks could be used to quantify the amount of materials bound to the sensor surface.

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36

Isoyama, Soichiro, and Eric Poisson. "Self-force as probe of internal structure." Classical and Quantum Gravity 29, no. 15 (July 13, 2012): 155012. http://dx.doi.org/10.1088/0264-9381/29/15/155012.

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37

Oetting, Janna B., Jessica R. Berry, Kyomi D. Gregory, Andrew M. Rivière, and Janet McDonald. "Specific Language Impairment in African American English and Southern White English: Measures of Tense and Agreement With Dialect-Informed Probes and Strategic Scoring." Journal of Speech, Language, and Hearing Research 62, no. 9 (September 20, 2019): 3443–61. http://dx.doi.org/10.1044/2019_jslhr-l-19-0089.

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Purpose In African American English and Southern White English, we examined whether children with specific language impairment (SLI) overtly mark tense and agreement structures at lower percentages than typically developing (TD) controls, while also examining the effects of dialect, structure, and scoring approach. Method One hundred six kindergartners completed 4 dialect-informed probes targeting 8 tense and agreement structures. The 3 scoring approaches varied in the treatment of nonmainstream English forms and responses coded as Other (i.e., those not obligating the target structure). The unmodified approach counted as correct only mainstream overt forms out of all responses, the modified approach counted as correct all mainstream and nonmainstream overt forms and zero forms out of all responses, and the strategic approach counted as correct all mainstream and nonmainstream overt forms out of all responses except those coded as Other. Results With the probes combined and separated, the unmodified and strategic scoring approaches showed lower percentages of overt marking by the SLI groups than by the TD groups; this was not always the case for the modified scoring approach. With strategic scoring and dialect-specific cut scores, classification accuracy (SLI vs. TD) was highest for the 8 individual structures considered together, the past tense probe, and the past tense probe irregular items. Dialect and structure effects and dialect differences in classification accuracy also existed. Conclusions African American English– and Southern White English–speaking kindergartners with SLI overtly mark tense and agreement at lower percentages than same dialect–speaking TD controls. Strategic scoring of dialect-informed probes targeting tense and agreement should be pursued in research and clinical practice.

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38

Doughty, Christopher E., and Adam Wolf. "Detecting 3D Vegetation Structure with the Galileo Space Probe: Can a Distant Probe Detect Vegetation Structure on Earth?" PLOS ONE 11, no. 12 (December 14, 2016): e0167188. http://dx.doi.org/10.1371/journal.pone.0167188.

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39

Maiuri, Margherita, Evgeny E. Ostroumov, Raphael G. Saer, Robert E. Blankenship, and Gregory Scholes. "Coherent wavepackets in the Fenna-Matthews-Olson complex are robust to excitonic-structure perturbations caused by mutagenesis." EPJ Web of Conferences 205 (2019): 10008. http://dx.doi.org/10.1051/epjconf/201920510008.

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The photosynthetic FMO complex is probed by femtosecond pump-probe spectroscopy and compared with a series of genetically modified mutants with distinct excitonic interactions. These experiments allow us to identify vibrational contributions to the coherence.

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40

Ma, D., Y. Sun, M. Wang, and Y. Gao. "Three-dimensional numerical modeling of a four-pin probe for soil water content." Soil Research 44, no. 2 (2006): 183. http://dx.doi.org/10.1071/sr05116.

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Soil probes with 4-pin configuration have been widely used in frequency domain (FD) and time domain reflectometry methods for determining soil water content. The techniques of FD sensors largely rely on the port impedance of the probe. This study provided a 3-dimensional numerical model to represent the electric behaviours of the 4-pin probe, which is valuable for analysing the effect of the soil dielectric constant, geometry, and the operating frequency on the port impedance of the probe. The model was performed with high frequency structure simulator software based on Maxwell’s equations and finite element method. A typical 3-dimensional electromagnetic distribution of the 4-pin probe was presented. The model was validated with 3 experiments under the aid of a network analyser. First, the experiment was performed using a series of fluids of known relative dielectric constants, then numerical simulations were carried out and confirmed by soil sample test with varying frequencies and the probe lengths. The effects of these parameters on FD methods are discussed based on the 4-pin probes. The 3-dimensional numerical model appears to be a meaningful tool to investigate more deeply a 4-pin probe in FD method.

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41

Padmanabhan, T. "Observational Constraints on Cosmological Models." International Astronomical Union Colloquium 148 (1995): 470–77. http://dx.doi.org/10.1017/s0252921100022387.

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AbstractCosmological models for structure formation are severely constrained by several of the recent observational results. We now have observations which probe the power spectrum of fluctuations from about 0.5 h−1 Mpc to 3000 h−1 Mpc. These probes and the constraints they imply on models for structure formation are reviewed.

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42

Karachevtsev, V. A., N. T. Kartel, L. V. Ivanov, A. N. Lyapunov, O. A. Nardid, Ya O. Cherkashina, and A. Yu Ivanov. "Change in the Microviscosity of Erythrocyte Membranes and Proteins in Blood Plasma after Graphene Oxide Addition: The ESR Spectroscopy Study." Journal of Spectroscopy 2019 (April 1, 2019): 1–8. http://dx.doi.org/10.1155/2019/8083207.

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The change in the microviscosity of erythrocyte membranes and the proteins in blood plasma after graphene oxide addition is studied by the ESR spectroscopy exploiting two spin probes with different lipophilic components in the structures. Experiments with charged spin probe 2 embedded into the erythrocyte membrane showed that the introduction of graphene oxide in small concentrations (∼70 μg/ml) into a suspension of erythrocytes did not lead to significant changes in the microviscosity of their membranes. Correlation times of hydrophobic spin probe 1 adsorbed to hydrophobic pockets of plasma proteins demonstrate a gradual slowdown at the graphene oxide injection into blood plasma that indicates a small deformation of the hydrophobic cavity of protein at the adsorption. However, this protein binding with graphene oxide does not cause the displacement of the spin probe from their hydrophobic cavities, which is evidence about small changes in the protein secondary structure. The obtained results indicate the insignificant cytotoxicity effect of small concentrations of graphene oxide for erythrocytes and blood plasma.

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43

Pomorski, Adam, Justyna Adamczyk, Anthony C. Bishop, and Artur Krężel. "Probing the target-specific inhibition of sensitized protein tyrosine phosphatases with biarsenical probes." Organic & Biomolecular Chemistry 13, no. 5 (2015): 1395–403. http://dx.doi.org/10.1039/c4ob02256d.

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A library of biarsenical probes was developed, characterized and used to probe structure–activity relationships for inhibition of sensitized protein tyrosine phosphatases (PTPs), revealing the superior inhibitory properties of 2′,7′-substituted biarsenicals.

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44

Frischer, Marc E., Peter J. Floriani, and Sandra A. Nierzwicki-Bauer. "Differential sensitivity of 16S rRNA targeted oligonucleotide probes used for fluorescence in situ hybridization is a result of ribosomal higher order structure." Canadian Journal of Microbiology 42, no. 10 (October 1, 1996): 1061–71. http://dx.doi.org/10.1139/m96-136.

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The use of 16S rRNA targeted gene probes for the direct analysis of microbial communities has revolutionized the field of microbial ecology, yet a comprehensive approach for the design of such probes does not exist. The development of 16S rRNA targeted oligonucleotide probes for use with fluorescence in situ hybridization (FISH) procedures has been especially difficult as a result of the complex nature of the rRNA target molecule. In this study a systematic comparison of 16S rRNA targeted oligonucleotide gene probes was conducted to determine if target location influences the hybridization efficiency of oligonucleotide probes when used with in situ hybridization protocols for the detection of whole microbial cells. Five unique universal 12-mer oligonucleotide sequences, located at different regions of the 16S rRNA molecule, were identified by a computer-aided sequence analysis of over 1000 partial and complete 16S rRNA sequences. The complements of these oligomeric sequences were chemically synthesized for use as probes and end labeled with either [γ-32P] ATP or the fluorescent molecule tetramethylrhodamine-5/-6. Hybridization sensitivity for each of the probes was determined by hybridization to heat-denatured RNA immobilized on blots or to formaldehyde fixed whole cells. All of the probes hybridized with equal efficiency to denatured RNA. However, the probes exhibited a wide range of sensitivity (from none to very strong) when hybridized with whole cells using a previously developed FISH procedure. Differential hybridization efficiencies against whole cells could not be attributed to cell wall type, since the relative probe efficiency was preserved when either Gram-negative or -positive cells were used. These studies represent one of the first attempts to systematically define criteria for 16S rRNA targeted probe design for use against whole cells and establish target site location as a critical parameter in probe design.Key words: 16S rRNA, oligonucleotide probes, in situ hybridization.

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45

Li, Shuang-ling, Jing Yang, Xiao-fei Lei, Jian-na Zhang, Hong-li Yang, Kun Li, and Chang-qing Xu. "Peptide-Conjugated Quantum Dots Act as the Target Marker for Human Pancreatic Carcinoma Cells." Cellular Physiology and Biochemistry 38, no. 3 (2016): 1121–28. http://dx.doi.org/10.1159/000443062.

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Background/Aims: In the present study, we describe a novel and straightforward approach to produce a cyclic- arginine-glycine-aspartic (RGD)-peptide-conjugated quantum dot (QD) probe as an ideal target tumor biomarker. Due to its specific structure, the probe can be used for targeted imaging of pancreatic carcinoma cells. Methods: Pancreatic carcinoma cells were routinely cultured and marked with QD-RGD probe. The QD-RGD probe on the fluorescence-labeled cancer cell was observed by fluorescence microscopy and laser confocal microscopy. Cancer cell viability was detected by MTT assay after culturing with QD-RGD probe. Results: Fluorescence microscopy and laser confocal microscopy displayed that 10nmol/L QD-RGD probe was able to effectively mark pancreatic carcinoma cells. In comparison with organic dyes and fluorescent proteins, the quantum dot-RGD probe had unique optical and electronic properties. Conclusion: QD-RGD probe has a low cytotoxicity with an excellent optical property and biocompatibility. These findings support further evaluation of QD-RGD probes for the early detection of pancreatic cancer.

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46

Nuthanakanti, Ashok, Ishtiyaq Ahmed, Saddam Y. Khatik, Kayarat Saikrishnan, and Seergazhi G. Srivatsan. "Probing G-quadruplex topologies and recognition concurrently in real time and 3D using a dual-app nucleoside probe." Nucleic Acids Research 47, no. 12 (May 20, 2019): 6059–72. http://dx.doi.org/10.1093/nar/gkz419.

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Abstract Comprehensive understanding of structure and recognition properties of regulatory nucleic acid elements in real time and atomic level is highly important to devise efficient therapeutic strategies. Here, we report the establishment of an innovative biophysical platform using a dual-app nucleoside analog, which serves as a common probe to detect and correlate different GQ structures and ligand binding under equilibrium conditions and in 3D by fluorescence and X-ray crystallography techniques. The probe (SedU) is composed of a microenvironment-sensitive fluorophore and an excellent anomalous X-ray scatterer (Se), which is assembled by attaching a selenophene ring at 5-position of 2′-deoxyuridine. SedU incorporated into the loop region of human telomeric DNA repeat fluorescently distinguished subtle differences in GQ topologies and enabled quantify ligand binding to different topologies. Importantly, anomalous X-ray dispersion signal from Se could be used to determine the structure of GQs. As the probe is minimally perturbing, a direct comparison of fluorescence data and crystal structures provided structural insights on how the probe senses different GQ conformations without affecting the native fold. Taken together, our dual-app probe represents a new class of tool that opens up new experimental strategies to concurrently investigate nucleic acid structure and recognition in real time and 3D.

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47

Sykes, Kiana S., and Ryan J. White. "Measuring Practical Reversibility of Surface-Bound DNA for Mechanistic Insight into Folding-Based Sensors." Journal of The Electrochemical Society 168, no. 11 (November 1, 2021): 116511. http://dx.doi.org/10.1149/1945-7111/ac3abe.

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In this paper we characterize the mass-transport-limited response of surface-tethered redox moieties via flexible DNA linkers using measured voltammetric peak current and peak potential splitting. We demonstrate that peak splitting can be used to differentiate between reversible, quasi-reversible, and irreversible electrochemical regimes of the tethered redox molecule. Interestingly, the transition from one regime to another is dependent on the length and structure of the DNA probe. For example, as the probe length increases the transition from reversible to quasi-reversible occurs at lower scan rates. Additionally, we directly compare the dependence of the peak splitting and peak current as a function of scan rate for ssDNA, dsDNA, and other structured nucleic acids such as stem-loop and pseudoknot probes. Lastly, we find that by interrogating our surfaces with cyclic voltammetry we can observe quantitative differences in the peak splitting once the aptamer is in a bound state and correlate this to the extent of conformational change the sequence undergoes. The observations reported herein are consistent with the postulation that signaling in this class of sensor architectures is dictated by changes in nucleic acid structure and flexibility, which controls the mass transfer rate of the redox probe to the surface of the electrode.

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48

Collins, C., G. R. Darling, and M. J. Rosseinsky. "The Flexible Unit Structure Engine (FUSE) for probe structure-based composition prediction." Faraday Discussions 211 (2018): 117–31. http://dx.doi.org/10.1039/c8fd00045j.

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49

Jang, Jihun, Jinwoo Kim, Hak Jong Lee, and Jin Ho Chang. "Transrectal Ultrasound and Photoacoustic Imaging Probe for Diagnosis of Prostate Cancer." Sensors 21, no. 4 (February 9, 2021): 1217. http://dx.doi.org/10.3390/s21041217.

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A combined transrectal ultrasound and photoacoustic (TRUS–PA) imaging probe was developed for the clear visualization of morphological changes and microvasculature distribution in the prostate, as this is required for accurate diagnosis and biopsy. The probe consisted of a miniaturized 128-element 7 MHz convex array transducer with 134.5° field-of-view (FOV), a bifurcated optical fiber bundle, and two optical lenses. The design goal was to make the size of the TRUS–PA probe similar to that of general TRUS probes (i.e., about 20 mm), for the convenience of the patients. New flexible printed circuit board (FPCB), acoustic structure, and optical lens were developed to meet the requirement of the probe size, as well as to realize a high-performance TRUS–PA probe. In visual assessment, the PA signals obtained with the optical lens were 2.98 times higher than those without the lens. Moreover, the in vivo experiment with the xenograft BALB/c (Albino, Immunodeficient Inbred Strain) mouse model showed that TRUS–PA probe was able to acquire the entire PA image of the mouse tight behind the porcine intestine about 25 mm depth. From the ex vivo and in vivo experimental results, it can be concluded that the developed TRUS–PA probe is capable of improving PA image quality, even though the TRUS–PA probe has a cross-section size and an FOV comparable to those of general TRUS probes.

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50

Silva, W. R. L. da, L. R. Prudencio Jr, and A. L. de Oliveira. "Probe penetration test applied for evaluating shotcrete compressive strength." Revista IBRACON de Estruturas e Materiais 5, no. 3 (June 2012): 362–87. http://dx.doi.org/10.1590/s1983-41952012000300007.

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This study presents a methodology for evaluating shotcrete compressive strength. Because of the high surface roughness and low thickness of the concrete layer observed in shotcrete structures, the proposed methodology is based on the probe penetration test. In a first phase, the variability of the probe penetration test was investigated to define the number of tests that are required to characterise the test correlation curve. Then, a procedure that can be applied to define the correlation curve was described. This procedure includes the moulding of shotcrete plates in loco, the control of the discharge energy of the pins, the extraction of the plates' samples to determine the concrete compressive strength, and statistical analysis. With the test correlation curve, an evaluation of the structure and data analysis can be performed. To verify the applicability of the proposed methodology, the structure of a shotcrete tunnel in a small hydropower plant was investigated. In the analysed structure, strength results that were non-compliant with the project specifications and a lack of concrete homogeneity were observed. Since the analysed methodology allowed for the characterisation of the considered structure conditions, the proposed solution is adequate for evaluating the compression strength of shotcrete structures.

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