Analysis and prediction of ground deformation in Yinxi Industrial Park based on time-series InSAR technology.

Monitoring ground deformation in industrial parks is of great importance for the economic development of urban areas. However, limited research has been conducted on the deformation mechanism in industrial parks, and there is a lack of integrated monitoring and prediction models. Therefore, this study proposes a comprehensive monitoring and prediction model for industrial parks, utilizing time-series Interferometry Synthetic Aperture Radar (InSAR) technology and the Whale Optimization Algorithm-Back Propagation (WOA-BP) neural network algorithm. Taking Yinxi Industrial Park in Baiyin District as a case study, we used 68 scenes of Sentinel-1A ascending and descending orbit data from June 2018 to April 2021. The Stanford Method for Persistent Scatterers-Permanent Scatterers (StaMPS-PS) and the Small Baseline Subsets-Interferometry Synthetic Aperture Radar (SBAS-InSAR) technologies were employed to obtain the surface deformation information of the park. The deformation information obtained by the two technologies was cross-validated in terms of temporal and spatial distribution, and the vertical and east-west deformation of the park was obtained by combining the ascending and descending orbit data. The results show that the deformation feature points in the line of sight (LOS) direction obtained by the two technologies have a high consistency in spatial distribution, using the ascending orbit data as an example. Additionally, the SBAS-InSAR technology was used to obtain the east-west and vertical deformation results of the park after merging the ascending and descending orbit data for the same period. It was found that the park is mainly affected by vertical deformation, with a maximum subsidence rate of 14.67 mm/yr. The subsidence areas correspond to the deformation positions observed in field survey photos. Based on the ascending orbit deformation data, the two technologies were validated with 585 points of the same latitude and longitude, and the coefficient of determination R2 was found to be 0.82, with a root mean square error (RMSE) of 2.20 mm/a. The deformation rates were also highly consistent. Due to the 47% increase in the number of sampling points provided by the StaMPS-PS technique compared to the SBAS-InSAR technique, the former was found to be more applicable in the industrial park. Based on the ground deformation mechanism in the park, we combined the StaMPS-PS technique with the WOA-BP neural network to construct a deformation zone prediction model. We conducted predictive studies on the deformation zones of buildings and roads within the park, and the results showed that the WOA-optimized BP neural network achieved higher accuracy and lower overall error compared to the unoptimized network. Finally, we analyzed and discussed the geological conditions and inducing factors of ground deformation in the park, providing a reference for a better understanding of the deformation mechanism and early warning of disasters in the industrial park.

Miniaturised gap sensor using fibre optic Fabry-Pérot interferometry for structural health monitoring.

A miniaturised structural health monitoring device has been developed capable of measuring the absolute distance between close parallel surfaces using Fabry-Pérot interferometry with nm-scale sensitivity. This is achieved by fabricating turning mirrors on two opposite cores of a multi-core fibre to produce a probe with dimensions limited only be the fibre diameter. Two fabrication processes have been investigated: Focused ion beam milling, which has resulted in a sensor measurement accuracy, sensitivity and range of ±0.056 µm, ±0.006 µm and ∼16000  µm respectively; and ultrafast laser assisted etching of the cleaved fibre end, where a sensor measurement accuracy, sensitivity and range of ±0.065 µm, ±0.006 µm and ∼7500 µm have been demonstrated.

Assessment of ground deformation and seismicity in two areas of intense hydrocarbon production in the Argentinian Patagonia.

The exploitation of both conventional and unconventional hydrocarbons may lead to still not well-known environmental consequences such as ground deformation and induced/triggered seismicity. Identifying and characterizing these effects is fundamental for prevention or mitigation purposes, especially when they impact populated areas. Two case studies of such effects on hydrocarbon-producing basins in Argentina, the Neuquén and the Golfo de San Jorge, are presented in this work. The intense hydrocarbon production activities in recent years and their potential link with the occurrence of two earthquakes of magnitude 4.9 and 5 near the operating well fields is assessed. A joint analysis of satellite radar interferometry and records of fluid injection and extraction demonstrate that, between 2017 and 2020, vertical ground displacements occurred in both study areas over active well fields that might indicate a correlation to hydrocarbon production activities. Coseismic deformation models of the two earthquakes constrain source depths to less than 2 km. The absence of seismicity before the beginning of the hydrocarbon activities in both areas, and the occurrence of the two largest and shallow earthquakes in the vicinity of the active well fields just after intensive production periods, points towards the potential association between both phenomena.

Assessment of presumed small-molecule ligands of telomeric i-DNA by biolayer interferometry (BLI).

Biolayer interferometry (BLI) and circular dichroism (CD) spectroscopy were used to investigate the interaction between previously reported i-motif DNA (i-DNA) ligands and folded or unfolded i-DNA in acidic (pH 5.5) and near-neutral (pH 6.5) conditions. We observed that although several ligands, in particular macrocyclic bis-acridine (BisA) and pyridostatin (PDS), showed good affinities for the telomeric i-motif forming sequence, none of the ligands displayed selective interactions with the i-DNA structure nor was able to promote its formation.

Assessment of the Measurement Performance of the Multimodal Fibre Optic Shape Sensing Configuration for a Morphing Wing Section.

In this paper, with the final aim of shape sensing for a morphing aircraft wing section, a developed multimodal shape sensing system is analysed. We utilise the method of interrogating a morphing wing section based on the principles of both hybrid interferometry and Fibre Bragg Grating (FBG) spectral sensing described in our previous work. The focus of this work is to assess the measurement performance and analyse the errors in the shape sensing system. This includes an estimation of the bending and torsional deformations of an aluminium mock-up section due to static loading that imitates the behaviour of a morphing wing trailing edge. The analysis involves using a detailed calibration procedure and a multimodal sensing algorithm to measure the deflection and shape. The method described In this paper, uses a standard single core optical fibre and two grating pairs on both the top and bottom surfaces of the morphing section. A study on the fibre placement and recommendations for efficient monitoring is also included. The analysis yielded a maximum deflection sensing error of 0.7 mm for a 347 × 350 mm wing section.

Tear film interferometry assessment after intense pulsed light in dry eye disease: A randomized, single masked, sham-controlled study.

BACKGROUND: Inadequate meibomian glands (MGs) secretion can lead to dry eye signs and symptoms. Tear film lipid layer (TFLL) secreted by MGs protects and prevents rapid evaporation of tear film. The purpose was to assess TFLL alteration and function in patients with evaporative dry eye (EDE) using tear interferometry after optimal pulse light technology (OPT) intense pulsed light (IPL). METHODS: This prospective randomized examiner-masked sham- controlled study included 86 participants (142 eyes) with DED. IPL or sham procedure was performed on day 0, 21, and 42. Ocular Surface Disease Index (OSDI), non-invasive breakup time (NITBUT), interferometric fringe pattern determined TFLL quality, fluorescein staining (FS), and meibum gland (MG) were assessed at day 0, 21, 42 and 3-month. RESULTS: At 3-month, TFLL, NITBUT, MG drop-out, MG quality, MG expressibility, FS and OSDI improved significantly (P < 0.05) in the IPL group, while the sham group had no significant improvements. Except for Meibo-score and FS, all parameters significantly correlated with the improvement in TFLL following IPL treatment. Additionally, artificial tears usage was significantly less in the IPL group from D-42 onwards. CONCLUSION: IPL treatment demonstrated the ability to improve TFLL quality and clinically reduced sign and symptoms of DED thereby reducing the frequency of artificial tears use.

Agreement between the Swept-Source Optical Coherence Tomography and the Image-Guided System for Biometry Assessment in Cataract Surgery.

PURPOSE: To assess the agreement on biometric data obtained using the Verion image-guided surgery system and the swept-source-OCT biometer IOL Master 700. MATERIALS AND METHODS: All patients underwent biometry using the SS-OCT and the Image-Guide System. The comparison between instruments was assessed using the Intraclass correlation coefficient (ICC). Level of Agreement (LoA) employing the Bland-Altman analysis. RESULTS: The image-based system produced significantly higher keratometry values, evidencing a low LoA between the SS-OCT and the image-based system, ranging from -1.30 D to 0.65 D (1.95 D), -1.04 D to 0.72 D (1.76 D), and -1.31 D to 0.65 D (1.96 D), respectively. The LoA for the Cylinder ranged from -0.46 D to 0.74 D (1.2 D) and from 0.82 to 0.94 mm for WTW. CONCLUSIONS: In our study, the SS-OCT biometer and the Image-based System evidenced statistically significant differences in measuring the main biometric parameters except for the WTW.

Evaluation of the Repeatability of the LacryDiag Ocular Surface Analyzer for Assessment of the Meibomian Glands and Tear Film.

Purpose: This study aimed to determine the intra- and interobserver repeatability of the new LacryDiag Ocular Surface Analyzer and compare it to a similar all-in-one device, the OCULUS Keratograph 5M. Methods: Thirty healthy subjects aged 18 years and above were recruited for this study. All patients were free of any existing ocular pathology. The LacryDiag Ocular Surface Analyzer was used to evaluate tear meniscus height, interferometry, noninvasive tear break-up time (NIBUT), and meibography. The same or analogous exams were performed using the OCULUS Keratograph 5M. Test equivalation was used to compare data from corresponding examinations. Paired t-tests and coefficient of variation were used to determine inter- and intraobserver repeatability. Bland-Altman analysis was used to determine level of agreement between devices. Results: There were no differences in mean values for tear meniscus height, NIBUT, or tear film interferometry between observers for either device. Significant differences were found between observers for meibography when using the LacryDiag (P = 0.008 for percent loss calculation and P = 0.004 for grading scale). Intra-observer variability for NIBUT was significantly higher for the Keratograph (P = 0.0003 for observer A and P < 0.0001 for observer B). Conclusions: There was a good correlation but poor agreement between devices for a given observer. This was likely influenced by the use of repeated testing and the non-dry eye cohort. Translational Relevance: Both the repeatability of the testing device and the use of multiple outcome measures are essential for the diagnosis and monitoring of patients with dry eye disease (DED).

The assessment of Pseudomonas aeruginosa lectin LecA binding characteristics of divalent galactosides using multiple techniques.

Pseudomonas aeruginosa is a widespread opportunistic pathogen that is capable of colonizing various human tissues and is resistant to many antibiotics. LecA is a galactose binding tetrameric lectin involved in adhesion, infection and biofilm formation. This study reports on the binding characteristics of mono- and divalent (chelating) ligands to LecA using different techniques. These techniques include affinity capillary electrophoresis, bio-layer interferometry, native mass spectrometry and a thermal shift assay. Aspects of focus include: affinity, selectivity, binding kinetics and residence time. The affinity of a divalent ligand was determined to be in the low-nanomolar range for all of the used techniques and with a ligand residence time of approximately 7 h, while no strong binding was seen to related lectin tetramers. Each of the used techniques provides a unique and complementary insight into the chelation based binding mode of the divalent ligand to the LecA tetramer.

Assessment of precision of astigmatism measurements taken by a sweptsource optical coherence tomography biometer - IOLMaster 700.

Purpose: : To assess the repeatability of ocular measurements, particularly astigmatism, taken using the latest version of an swept-source optical coherence tomography (SS-OCT) device, IOLMaster 700. Methods: This prospective observational study done in a private eye care centre. Study included 213 eyes of 152 patients diagnosed with cataract. Axial length (AL), Anterior corneal astigmatism (ΔK), Total corneal astigmatism (ΔTK), Aqueous depth (AD), Lens thickness (LT), Iris barycentre distance (IBD) and White to white distance (WTW) were analysed; three measurements were taken for each patient in the same sitting by the same examiner in an undilated state using the SS-OCT device. Repeatability was analysed using intraclass coefficient (ICC) and coefficient of variation (CV) measures, and astigmatism values were transformed into vector components (J0/J45) and categorised based on magnitude. Results: Astigmatism vector components (J0/J45) showed poor repeatability (ICC < 0.5 and CV > 0), while iris coordinates (IBD) and astigmatism magnitude had good correlation (ICC > 0.9) but more variations between the readings which was least for magnitude ≥ 1.5D; however, rest of the parameters demonstrated excellent repeatability (ICC > 0.9 with P value < 0.05). Conclusion: IOLMaster 700 demonstrated good reliability for the parameters measured, although, for astigmatism and iris barycentre distance, more number of readings and cross reference with other devices may be required to get clinically accurate results.

A Coherence Improvement Method Based on Sub-Aperture InSAR for Human Activity Detection.

Human activity detection plays an important role in social security monitoring. Since human activity is very weak, it is necessary to employ the repeat-pass Interferometric Synthetic Aperture Radar (InSAR) technique to detect the potential activity between two data acquisitions; a high level of coherence is required for detection. With the object of detecting human activity of interest, this paper presents a coherence improvement approach based on sub-aperture InSAR for human activity detection. Different sub-apertures contain different scattering information of the target, as they represent the backscatter of the target from a different range of angles. Integrating corresponding sub-aperture interferometric results can improve the coherence between two complex images compared to the entire synthetic aperture, as well as removing a little disturbance in some circumstances. To validate the method presented in this paper, the actual airborne Ka-band frequency modulated continuous wave (FMCW) InSAR data acquired by the Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS) are utilized. The experimental results demonstrate that the proposed method can effectively improve the coherence between two complex SAR images and can validly detect human activity of interest.

Manual interferometric device for routine non-invasive tear film break-up time assessment.

Purpose: To determine the feasibility of non-invasive tear break-up time (NIBUT) assessment using the Handheld tear lipid layer thickness assessment instrument and compare it with the standard tear break-up time (TBUT) test and other dry eye tests.Subjects and methods: 108 subjects were enrolled, 56 with and 52 without dry eye symptoms. Schein questionnaire was used to determine the severity of dry eye symptoms. Ocular signs were assessed by NIBUT, TBUT, lipid layer thickness (LLT), lid-parallel conjunctival folds (LIPCOF), conjunctival hyperemia, and corneal staining.Results: Median NIBUT and TBUT, and other clinical test values significantly differed among the dry eye symptoms group and control group. NIBUT yielded the most significant difference between the groups (NIBUT: 7 sec vs. 17.5 sec, p < .001, Z = 5.94; TBUT: 5 sec vs. 10 sec, p < .001, Z = 4.38; LLT: p = .007; LIPCOF: p < .001, conjunctival hyperemia: p < .047, corneal staining: p < .010). Spearman's test showed a significant correlation between NIBUT and TBUT (p < .001), NIBUT and LLT (p = .001), NIBUT and LIPCOF (p = .019), NIBUT and conjunctival hyperemia (p = .002), and NIBUT and corneal staining (p = .012) in the dry eye symptoms group. NIBUT did not significantly differ among the three measurements in both groups of patients (p = .061, p = .096), while TBUT values did in the control group (p < .001). Short NIBUT values were the main predictors and indicators of dry eye complaints (AOR = 0.87, p < .001), superior to TBUT (AOR = 0.88, p = .008) and other tests even after adjustment for age and gender.Conclusion: NIBUT measured by Handheld instrument is a simple, accessible, practical, and, most of all, reproducible and objective method that might allow NIBUT assessment on a regular basis.

Fiber Optic Sensors for Vital Signs Monitoring. A Review of Its Practicality in the Health Field.

Vital signs not only reflect essential functions of the human body but also symptoms of a more serious problem within the anatomy; they are well used for physical monitoring, caloric expenditure, and performance before a possible symptom of a massive failure-a great variety of possibilities that together form a first line of basic diagnosis and follow-up on the health and general condition of a person. This review includes a brief theory about fiber optic sensors' operation and summarizes many research works carried out with them in which their operation and effectiveness are promoted to register some vital sign(s) as a possibility for their use in the medical, health care, and life support fields. The review presents methods and techniques to improve sensitivity in monitoring vital signs, such as the use of doping agents or coatings for optical fiber (OF) that provide stability and resistance to the external factors from which they must be protected in in vivo situations. It has been observed that most of these sensors work with single-mode optical fibers (SMF) in a spectral range of 1550 nm, while only some work in the visible spectrum (Vis); the vast majority, operate through fiber Bragg gratings (FBG), long-period fiber gratings (LPFG), and interferometers. These sensors have brought great advances to the measurement of vital signs, especially with regard to respiratory rate; however, many express the possibility of monitoring other vital signs through mathematical calculations, algorithms, or auxiliary devices. Their advantages due to miniaturization, immunity to electromagnetic interference, and the absence of a power source makes them truly desirable for everyday use at all times.

Critical assessment of relevant methods in the field of biosensors with direct optical detection based on fibers and waveguides using plasmonic, resonance, and interference effects.

Direct optical detection has proven to be a highly interesting tool in biomolecular interaction analysis to be used in drug discovery, ligand/receptor interactions, environmental analysis, clinical diagnostics, screening of large data volumes in immunology, cancer therapy, or personalized medicine. In this review, the fundamental optical principles and applications are reviewed. Devices are based on concepts such as refractometry, evanescent field, waveguides modes, reflectometry, resonance and/or interference. They are realized in ring resonators; prism couplers; surface plasmon resonance; resonant mirror; Bragg grating; grating couplers; photonic crystals, Mach-Zehnder, Young, Hartman interferometers; backscattering; ellipsometry; or reflectance interferometry. The physical theories of various optical principles have already been reviewed in detail elsewhere and are therefore only cited. This review provides an overall survey on the application of these methods in direct optical biosensing. The "historical" development of the main principles is given to understand the various, and sometimes only slightly modified variations published as "new" methods or the use of a new acronym and commercialization by different companies. Improvement of optics is only one way to increase the quality of biosensors. Additional essential aspects are the surface modification of transducers, immobilization strategies, selection of recognition elements, the influence of non-specific interaction, selectivity, and sensitivity. Furthermore, papers use for reporting minimal amounts of detectable analyte terms such as value of mass, moles, grams, or mol/L which are difficult to compare. Both these essential aspects (i.e., biochemistry and the presentation of LOD values) can be discussed only in brief (but references are provided) in order to prevent the paper from becoming too long. The review will concentrate on a comparison of the optical methods, their application, and the resulting bioanalytical quality.

Time-of-flight resolved light field fluctuations reveal deep human tissue physiology.

Red blood cells (RBCs) transport oxygen to tissues and remove carbon dioxide. Diffuse optical flowmetry (DOF) assesses deep tissue RBC dynamics by measuring coherent fluctuations of multiply scattered near-infrared light intensity. While classical DOF measurements empirically correlate with blood flow, they remain far-removed from light scattering physics and difficult to interpret in layered media. To advance DOF measurements closer to the physics, here we introduce an interferometric technique, surmounting challenges of bulk motion to apply it in awake humans. We reveal two measurement dimensions: optical phase, and time-of-flight (TOF), the latter with 22 picosecond resolution. With this multidimensional data, we directly confirm the unordered, or Brownian, nature of optically probed RBC dynamics typically assumed in classical DOF. We illustrate how incorrect absorption assumptions, anisotropic RBC scattering, and layered tissues may confound classical DOF. By comparison, our direct method enables accurate and comprehensive assessment of blood flow dynamics in humans.

Assessment of Antibody Self-Interaction by Bio-Layer-Interferometry as a Tool for Early Stage Formulation Development.

PURPOSE: To speed up the drug development process in the biopharmaceutical industry, high throughput methods are indispensable for assessing drug candidates and potential lead formulations, in particular during late stages of discovery and early phases of development. This study aimed to establish a bio-layer-interferometry based high throughput assay for assessing formulation dependent mAb self-interaction (SI-BLI) and to compare the results with kD values obtained by dynamic light scattering (DLS). METHODS: Self-interaction of proprietary and commercially available mAbs was analyzed by SI-BLI and dynamic light scattering (DLS). RESULTS: We found significant correlations of the SI-BLI results and kD-values obtained by DLS for both, different mAbs in one platform formulation and for mAbs formulated in several buffer compositions. In total, we assessed self-interaction propensity of different mAbs in 58 formulations and found significant Pearson correlation (p < 0.05) between kD and results of SI-BLI. CONCLUSIONS: The SI-BLI results correlate with kD and enable fast ranking of both different drug candidates and potential lead formulations. Thus, SI-BLI might decrease the risk to lose potent mAb candidates during transition from discovery to development, and help to accelerate the development of high concentration liquid formulations.

Quantitative analysis of a micro array anode structured target for hard x-ray grating interferometry.

Talbot-Lau interferometry (TLI) provides additional contrast modes for x-ray imaging that are complementary to conventional absorption radiography. TLI is particularly interesting because it is one of the few practical methods for realizing phase contrast with x-rays that is compatible with large-spot high power x-ray sources. A novel micro array anode structured target (MAAST) x-ray source offers several advantages for TLI over the conventional combination of an extended x-ray source coupled with an absorption grating including higher flux and larger field of view, and these advantages become more pronounced for x-ray energies in excess of 30 keV. A Monte Carlo simulation was performed to determine the optimal parameters for a MAAST source for use with TLI. It was found that the both spatial distribution of x-ray production and the number of x-ray produced in the MAAST have a strong dependence on the incidence angle of the electron beam.

Interferometric Reflectance Imaging Sensor (IRIS) for Molecular Kinetics with a Low-Cost, Disposable Fluidic Cartridge.

The determination of kinetic information and appropriate binding pairs is fundamental to the proper optimization and selection of ligands used in immunoassays, diagnostics, and therapeutics. However, the ability to estimate such parameters in a multiplexed and inexpensive format remains difficult and modification of the ligand is often necessary. Here, we detail the methods and materials necessary to evaluate hundreds of unlabeled ligands simultaneously using the interferometric reflectance imaging sensor (IRIS). The incorporation of a low-cost fluidic cartridge that integrates on the top of the sensor simplifies reagent handling considerably.

Design optimization of a periodic microstructured array anode for hard x-ray grating interferometry.

Talbot-Lau grating interferometer (TLGI) has great advantages in x-ray imaging contrasts, especially for low-Z materials, over conventional absorption contrast. A microstructured array anode target (MAAT) source offers significantly higher imaging throughput than the combination of an extended x-ray source paired with an absorption grating (also known as source grating). The performance of the MAAT source can be optimized with respect to the areal density, dimensions, and choice of material for the microstructured metal inserts (MMI) and the substrate in which they are embedded. In this paper, we analyze the x-ray generation efficiency per incident electron, relative fraction of x-rays generated by MMI and substrate, x-ray spectrum, and angular distribution via Monte Carlo simulation. Based on the simulation results, the optimal parameters are obtained for a MAAT with incident electron energies from 30 keV to 120 keV. The corresponding temperature distribution within the MAAT is also simulated for the optimal set of the parameters via finite element analysis. As demonstrated by the thermal analysis data, the maximum allowable electron-beam power loading was derived that allows a stable operation of the transmission MAAT.

Low-cost and user-friendly biosensor to test the integrity of mRNA molecules suitable for field applications.

The use of mRNA in biotechnology has expanded with novel applications such as vaccines and therapeutic mRNA delivery recently demonstrated. For mRNA to be used in patients, quality control assays will need to be routinely established. Currently, there is a gap between the highly sophisticated RNA integrity tests available and broader application of mRNA-based products by non-specialist users, e.g. in mass vaccination campaigns. Therefore, the aim of this work was to develop a low-cost biosensor able to test the integrity of a mRNA molecule with low technological requirements and easy end-user application. The biosensor is based on a bi-functional fusion protein, composed by the λN peptide that recognizes its cognate aptamer encoded on the 5' end of the RNA under study and ß-lactamase, which is able to produce a colorimetric response through a simple test. We propose two different mechanisms for signal processing adapted to two levels of technological sophistication, one based on spectrophotometric measurements and other on visual inspection. We show that the proposed λN-ßLac chimeric protein specifically targets its cognate RNA aptamer, boxB, using both gel shift and biolayer interferometry assays. More importantly, the results presented confirm the biosensor performs reliably, with a wide dynamic range and a proportional response at different percentages of full-length RNA, even when gene-sized mRNAs were used. Thus, the features of the proposed biosensor would allow to end-users of products such as mRNA vaccines to test the integrity of the product before its application in a low-cost fashion, enabling a more reliable application of these products.