Installation of a High Sensitivity Ocean Borehole Strainmeter in the Nankai Trough Under Severe Sea Current Conditions

2018 ◽  
Vol 52 (3) ◽  
pp. 128-137
Author(s):  
Yuya Machida ◽  
Eiichiro Araki ◽  
Toshinori Kimura ◽  
Demian M. Saffer ◽  
Tomokazu Saruhashi ◽  
...  
Keyword(s):  
Nankai Trough ◽  
High Sensitivity ◽  
Recording Device ◽  
Pressure Data ◽  
Cement Slurry ◽  
Mechanical Coupling ◽  
Vortex Induced Vibrations ◽  
Highly Sensitive ◽  
Borehole Strainmeter ◽  
Vibration Tests

AbstractA high-sensitivity volumetric strainmeter has been installed into the C0010 borehole observatory using the drilling vessel (D/V) Chikyu during the Expedition 365 cruise in the Nankai Trough, Japan. At this location, crustal deformation occurs in association with large interplate earthquakes. However, strong Kuroshio ocean currents cause vortex-induced vibrations (VIVs) in the region, which can cause fatal damage to the strainmeter. Therefore, laboratory vibration tests were performed prior to installation to confirm that the antivibration mechanism inside the strainmeter was functional against the severe vibrations during installation. VIV was measured prior to installing the strainmeter into the C0010A borehole using accelerometers at the installation site. The results indicated that the VIV were within the specification of the antivibration mechanism. This meant that installation of the strainmeter into the borehole was possible. To maximize sensor sensitivity, it is extremely important to ensure mechanical coupling of the strainmeter with the borehole wall by cementing operation after installation. The cementing process was confirmed using a pressure recording device incorporated within the strainmeter. Pressure data clearly showed that seawater had been displaced with cement slurry. Data from the strainmeter clearly showed tidal waveforms, which are comparable to those of pressure data recorded by a borehole pressure sensor installed at approximately the same depth. Accuracies of the strain data were validated through the procedure. They suggest that the first installation of the ocean borehole strainmeter in the Nankai Trough was successful, and therefore, highly sensitive strain measurement is now possible in a seismically active area.

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

scholarly journals Highly sensitive detection of nitrobenzene by a series of fluorescent 2D zinc(ii) metal–organic frameworks with a flexible triangular ligand

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 23975-23984
Author(s):  
Xue Yang ◽  
Yixia Ren ◽  
Hongmei Chai ◽  
Xiufang Hou ◽  
Zhixiang Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Organic Frameworks ◽  
High Sensitivity ◽  
Fluorescent Sensors ◽  
Sensitive Detection ◽  
Donor Ligands ◽  
Highly Sensitive ◽  
Metal Organic ◽  
Highly Sensitive Detection

Four fluorescent 2D Zn-MOFs based on a flexible triangular ligand and linear N-donor ligands are hydrothermally prepared and used to detect nitrobenzene in aqueous solution with high sensitivity, demonstrating their potential as fluorescent sensors.

Rapid, highly sensitive and quantitative detection of interleukin 6 based on SERS magnetic immunoassay

2021 ◽  
Vol 13 (15) ◽  
pp. 1823-1831
Author(s):  
Xiaomei Wang ◽  
Li Ma ◽  
Shijiao Sun ◽  
Tingwei Liu ◽  
Hao Zhou ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
High Sensitivity ◽  
Quantitative Detection ◽  
Detection Time ◽  
Highly Sensitive ◽  
Sandwich Method

We have developed a SERS magnetic immunoassay method based on the principle of sandwich method for rapid and quantitative detection of IL-6. The developed SERS method has the advantages of high sensitivity and detection time is only 15 min.

scholarly journals Highly Sensitive Fluorescent Detection of Acetylcholine Based on the Enhanced Peroxidase-Like Activity of Histidine Coated Magnetic Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1207
Author(s):  
Hong Jae Cheon ◽  
Quynh Huong Nguyen ◽  
Moon Il Kim
Keyword(s):  
Magnetic Nanoparticles ◽  
High Sensitivity ◽  
High Specificity ◽  
Choline Oxidase ◽  
Fluorescent Detection ◽  
One Pot ◽  
Site Structure ◽  
Specificity And Sensitivity ◽  
Highly Sensitive ◽  
Peroxidase Mimics

Inspired by the active site structure of natural horseradish peroxidase having iron as a pivotal element with coordinated histidine residues, we have developed histidine coated magnetic nanoparticles (His@MNPs) with relatively uniform and small sizes (less than 10 nm) through one-pot heat treatment. In comparison to pristine MNPs and other amino acid coated MNPs, His@MNPs exhibited a considerably enhanced peroxidase-imitating activity, approaching 10-fold higher in catalytic reactions. With the high activity, His@MNPs then were exploited to detect the important neurotransmitter acetylcholine. By coupling choline oxidase and acetylcholine esterase with His@MNPs as peroxidase mimics, target choline and acetylcholine were successfully detected via fluorescent mode with high specificity and sensitivity with the limits of detection down to 200 and 100 nM, respectively. The diagnostic capability of the method is demonstrated by analyzing acetylcholine in human blood serum. This study thus demonstrates the potential of utilizing His@MNPs as peroxidase-mimicking nanozymes for detecting important biological and clinical targets with high sensitivity and reliability.

scholarly journals Spatial expression pattern of serine proteases in the blood fluke Schistosoma mansoni determined by fluorescence RNA in situ hybridization

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lenka Ulrychová ◽  
Pavel Ostašov ◽  
Marta Chanová ◽  
Michael Mareš ◽  
Martin Horn ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Schistosoma Mansoni ◽  
Rna Sequencing ◽  
Serine Proteases ◽  
Expression Patterns ◽  
High Sensitivity ◽  
Host Parasite Interactions ◽  
Highly Sensitive ◽  
Host Parasite

Abstract Background The blood flukes of genus Schistosoma are the causative agent of schistosomiasis, a parasitic disease that infects more than 200 million people worldwide. Proteases of schistosomes are involved in critical steps of host–parasite interactions and are promising therapeutic targets. We recently identified and characterized a group of S1 family Schistosoma mansoni serine proteases, including SmSP1 to SmSP5. Expression levels of some SmSPs in S. mansoni are low, and by standard genome sequencing technologies they are marginally detectable at the method threshold levels. Here, we report their spatial gene expression patterns in adult S. mansoni by the high-sensitivity localization assay. Methodology Highly sensitive fluorescence in situ RNA hybridization (FISH) was modified and used for the localization of mRNAs encoding individual SmSP proteases (including low-expressed SmSPs) in tissues of adult worms. High sensitivity was obtained due to specifically prepared tissue and probes in combination with the employment of a signal amplification approach. The assay method was validated by detecting the expression patterns of a set of relevant reference genes including SmCB1, SmPOP, SmTSP-2, and Sm29 with localization formerly determined by other techniques. Results FISH analysis revealed interesting expression patterns of SmSPs distributed in multiple tissues of S. mansoni adults. The expression patterns of individual SmSPs were distinct but in part overlapping and were consistent with existing transcriptome sequencing data. The exception were genes with significantly low expression, which were also localized in tissues where they had not previously been detected by RNA sequencing methods. In general, SmSPs were found in various tissues including reproductive organs, parenchymal cells, esophagus, and the tegumental surface. Conclusions The FISH-based assay provided spatial information about the expression of five SmSPs in adult S. mansoni females and males. This highly sensitive method allowed visualization of low-abundantly expressed genes that are below the detection limits of standard in situ hybridization or by RNA sequencing. Thus, this technical approach turned out to be suitable for sensitive localization studies and may also be applicable for other trematodes. The results suggest that SmSPs may play roles in diverse processes of the parasite. Certain SmSPs expressed at the surface may be involved in host–parasite interactions. Graphic abstract

scholarly journals A flexible and highly sensitive pressure sensor based on three-dimensional electrospun carbon nanofibers

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 13898-13905
Author(s):  
Chuan Cai ◽  
He Gong ◽  
Weiping Li ◽  
Feng Gao ◽  
Qiushi Jiang ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Pressure Sensor ◽  
Carbon Nanofiber ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Highly Sensitive ◽  
Sensitive Pressure

A three-dimensional electrospun carbon nanofiber network was used to measure press strains with high sensitivity.

scholarly journals Dual functionality metamaterial enables ultra-compact, highly sensitive uncooled infrared sensor

Nanophotonics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 1337-1346
Author(s):  
Jin Tao ◽  
Zhongzhu Liang ◽  
Guang Zeng ◽  
Dejia Meng ◽  
David R. Smith ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Metamaterial Absorber ◽  
Bulk Acoustic Wave ◽  
Infrared Sensors ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Highly Sensitive ◽  
Film Bulk ◽  
Perfect Metamaterial Absorber ◽  
High Absorption

Abstract Cointegration and coupling a perfect metamaterial absorber (PMA) together with a film bulk acoustic wave resonator (FBAR) in a monolithic fashion is introduced for the purpose of producing ultracompact uncooled infrared sensors of high sensitivity. An optimized ultrathin multilayer stack was implemented to realize the proposed device. It is experimentally demonstrated that the resonance frequency of the FBAR can be used efficiently as a sensor output as it downshifts linearly with the intensity of the incident infrared irradiation. The resulting sensor also achieves a high absorption of 88% for an infrared spectrum centered at a wavelength of 8.2 μm. The structure is compact and can be easily integrated on a CMOS-compatible chip since both the FBAR and PMA utilize and share the same stack of metal and dielectric layers.

Optically pumped magnetometers enable a new level of biomagnetic measurements

2020 ◽  
Vol 9 (5) ◽  
pp. 247-251
Author(s):  
Tilmann Sander ◽  
Anna Jodko-Władzińska ◽  
Stefan Hartwig ◽  
Rüdiger Brühl ◽  
Thomas Middelmann
Keyword(s):  
Quantum Interference ◽  
High Sensitivity ◽  
High Temporal Resolution ◽  
Optically Pumped ◽  
New Class ◽  
Magnetic Shields ◽  
Highly Sensitive ◽  
Electric And Magnetic Fields ◽  
Auditory Evoked Fields

AbstractThe electrophysiological activities in the human body generate electric and magnetic fields that can be measured noninvasively by electrodes on the skin, or even, not requiring any contact, by magnetometers. This includes the measurement of electrical activity of brain, heart, muscles and nerves that can be measured in vivo and allows to analyze functional processes with high temporal resolution. To measure these extremely small magnetic biosignals, traditionally highly sensitive superconducting quantum-interference devices have been used, together with advanced magnetic shields. Recently, they have been complemented in usability by a new class of sensors, optically pumped magnetometers (OPMs). These quantum sensors offer a high sensitivity without requiring cryogenic temperatures, allowing the design of small and flexible sensors for clinical applications. In this letter, we describe the advantages of these upcoming OPMs in two exemplary applications that were recently carried out at Physikalisch-Technische Bundesanstalt (PTB): (1) magnetocardiography (MCG) recorded during exercise and (2) auditory-evoked fields registered by magnetoencephalography.

scholarly journals Hybrid Grating in Reduced-Diameter Fiber for Temperature-Calibrated High-Sensitivity Refractive Index Sensing

2019 ◽  
Vol 9 (9) ◽  
pp. 1923
Author(s):  
Biqiang Jiang ◽  
Zhen Hao ◽  
Dingyi Feng ◽  
Kaiming Zhou ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Surrounding Medium ◽  
High Sensitivity ◽  
Fiber Grating ◽  
Bragg Resonance ◽  
Core Mode ◽  
Promising Alternative ◽  
Sensing Applications ◽  
Highly Sensitive

We propose and experimentally demonstrate a hybrid grating, in which an excessively tilted fiber grating (Ex-TFG) and a fiber Bragg grating (FBG) were co-inscribed in a reduced-diameter fiber (RDF). The hybrid grating showed strong resonances due to coupling among core mode and a set of polarization-dependent cladding modes. This coupling showed enhanced evanescent fields by the reduced cladding size, thus allowing stronger interaction with the surrounding medium. Moreover, the FBG’s Bragg resonance confined by the thick cladding was exempt from the change of the surrounding medium’s refractive index (RI), and then the FBG can work as a temperature compensator. As a result, the Ex-TFG in RDF promised a highly sensitive RI measurement, with a sensitivity up to ~1224 nm/RIU near the RI of 1.38. Through simultaneous measurement of temperature and RI, the temperature dependence of water’s RI is then determined. Therefore, the proposed hybrid grating with a spectrum of multi-peaks embedded with a sharp Bragg resonance is a promising alternative for the simultaneous measurement of multi-parameters for many RI-based sensing applications.

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