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Purpose: To determine the effects of strabismus on dry eye parameters. Methods: In this cross-sectional study, the preliminary assessment of ocular parameters related to dry eye disease was performed in patients with untreated concomitant strabismus. In total, 204 patients with concomitant strabismus and 125 volunteers without strabismus (4 to 30 years old, 170 male and 159 female) were enrolled. The Ocular Surface Disease Index questionnaire (OSDI) was administered, and ocular surface was examined using the Oculus Keratograph 5M (Oculus Optikgeräte GmbH) to collect data on tear film break-up time (TBUT), ocular redness index (based on bulbar conjunctival blood vessel engorgement), and meibomian gland atrophy. Subgroup analysis was performed based on strabismus type (concomitant exotropia, concomitant esotropia, and non-strabismus); age (juvenile versus adults age > 18 years); and 5- to 10-year and 10- to 20-year strabismus course, according to an age of 12 years. Results: Concomitant exotropia and esotropia were reported in 134 and 70 patients, respectively. A total of 125 healthy volunteers were recruited. The three groups showed significant differences in the ocular redness index (right eye: P = .012, left eye: P = .018). In contrast, other parameters were not significantly different. Similarly, no statistical differences in ocular surface indicators were observed when patients were divided by age ( P > .05 for all) and the 5- to 10-year and 10-to 20-year strabismus course. The meibomian gland showed varying degrees atrophy in both strabismus and non-strabismus groups. Conclusions: Strabismus does not affect tear film stability with age in this cohort with constant strabismus up to 30 years, indicating that strabismus may not increase the risk of dry eye disease. [ J Pediatr Ophthalmol Strabismus . 20XX;X(X):XX–XX.]

Surface wave methods have been developed as a commonly used non-invasive tool for shear-wave velocity (Vs) profiling of near-surface soil and rock formations. Inversion is a key step to back-calculate the Vs profile from dispersion curves; however, the non-linear and ill-posed nature of the problem sometimes yields non-unique Vs profiles. To overcome these challenges, a new method was developed to circumvent inversion and directly estimate Vs profiles from the fundamental mode dispersion trend for sites with Vs gradually increasing with depth. This method is developed based on the relationship between the phase velocity of surface waves at a given frequency with the time-averaged shear-wave velocity within a depth of one-half wavelength. Three field sites and three simulated sites covering shallow, medium and deep locations with gradually increasing Vs with depth are employed to verify the feasibility of the proposed methodology. Results indicate that the method can efficiently give a reasonable and realistic estimation of Vs profiles. The goal of this method is to provide an alternative to obtain Vs profiles with high certainty and low computational cost for surface wave testing, but not necessarily to find a ‘better’ profile than inversion or to locate each layer interface.

Purpose: To evaluate the ocular biometric parameters in patients with constant and intermittent exotropia by the measurement of swept-source optical coherence tomography (SS-OCT) optical biometer OA-2000 and comparing it with the normal control subjects.Design: Cross-sectional case-control study.Participants: Fifty-five constant and 24 intermittent patients with exotropia with central fixation and 77 orthotropic normal control participants aged 4–18 years old.Methods: Non-contact and high-resolution optical biometric OA-2000 measurements were conducted under uniform ambient light conditions. The statistical analysis included intraclass correlation coefficient (ICC), Bland-Altman plot, and independent t-tests.Main Outcome Measures: Spherical equivalent (SE), ocular biological parameters such as pupil diameter (PD), anterior chamber depth (ACD), lens thickness (LT), and axial lengths (AL). The absolute values of inter-eye differences for SE, PD, ACD, LT, and AL were recorded as AnisoSE, AnisoPD, AnisoACD, AnisoLT, and AnisoAL, respectively.Results: AnisoSE (0.878 vs. 0.577, P = 0.019), AnisoAL (0.395 vs. 0.208, P = 0.001), AnisoACD (0.060 vs. 0.032, P < 0.001), AnisoLT (0.060 vs. 0.031, P = 0.002), and AnisoPD (0.557 vs. 0.340, P = 0.002) were significantly larger in concomitant patients with exotropia. The SE, AL, ACD, LT, and PD showed excellent binocular correlation with ICC values that ranged from 0.943 to 0.987 in control participants and from 0.767 to 0.955 in concomitant exotropia patients. Bland-Altman plots showed the wider range of agreement in patients with concomitant exotropia than the control participants (SE: 5.0288 vs. 3.3258; AL: 2.2146 vs. 1.3172; ACD:0.3243 vs. 0.1682; PD: 2.4691 vs. 1.9241; and LT:0.3723 vs 0.1858).Conclusion: Patients with concomitant exotropia showed larger inter-eye differences in SE, ACD, LT, PD, and AL. Advice should be given to suspicious children to avoid or delay the development of concomitant exotropia.

Surface wave methods have been extensively employed to estimate time-averaged shear-wave velocity (Vs) to 30 m (Vs,30) for seismic site classification. However, the inversion of surface wa...

Asphalt overlays have been commonly used to extend the service life of deteriorated concrete bridge decks. Nonlinear, viscoelastic asphalt has properties that differ considerably from the properties of the underlying portland cement concrete (PCC) deck. The impact echo (IE) method has been extensively used to nondestructively evaluate PCC structures. The method, however, performs differently on asphalt overlays, especially when a membrane is placed between the overlay and the deck. The general recommendation has been to perform IE tests on asphalt overlays in cold weather. The temperature range under which IE can be used, however, is still uncertain. This study was conducted to systematically examine IE performance on asphalt overlays. Three PCC specimens with three types of asphalt overlays―asphalt with a liquid membrane, asphalt with a sheet membrane, and asphalt without a membrane―were tested in a temperature chamber. The three PCC specimens had identical designs, materials, and artificial defects. The nondestructive evaluation (NDE) results from the tests indicate that: (1) 32°F and below is the appropriate temperature range for IE to detect defects in the underlying deck; and (2) membranes can significantly reduce the propagation of waves into the underlying deck.

Objective. To explore the pharmacological mechanism of Liuwei Dihuang decoction (LDD) for diabetic retinopathy (DR). Methods. The potential targets of LDD were predicted by PharmMapper. GeneCards and other databases were used to collect DR genes. Cytoscape was used to construct and analyze network DR and LDD’s network, and DAVID was used for Gene Ontology (GO) and pathway enrichment analysis. Finally, animal experiments were carried out to verify the results of systematic pharmacology. Results. Five networks were constructed and analyzed: (1) diabetic retinopathy genes’ PPI network; (2) compound-compound target network of LDD; (3) LDD-DR PPI network; (4) compound-known target network of LDD; (5) LDD known target-DR PPI network. Several DR and treatment-related targets, clusters, signaling pathways, and biological processes were found. Animal experiments found that LDD can improve the histopathological changes of the retina. LDD can also increase erythrocyte filtration rate and decrease the platelet adhesion rate ( P < 0.05 ) and decrease MDA and TXB2 ( P < 0.05 ). Compared with the model group, the retinal VEGF and HIF-1α expression in the LDD group decreased significantly ( P < 0.05 ). Conclusion. The therapeutic effect of LDD on DR may be achieved by interfering with the biological processes (such as response to insulin, glucose homeostasis, and regulation of angiogenesis) and signaling pathways (such as insulin, VEGF, HIF-1, and ErbB signaling pathway) related to the development of DR that was found in this research.

PurposeTo compare the biometric characteristics between concomitant exotropia (XT) and orthotropia (OT) with OA2000.MethodThis cross-sectional study collected 4–18 years old children. All subjects underwent a comprehensive ophthalmic examination and prism alternate cover test for ocular alignment measurement. Included subjects had no any eye surgery, structural ocular anomalies, amblyopia of either eyes, ptosis, cataract and nystagmus. OA-2000 was used for the measurement of ocular biological parameters. Spherical equivalent (SE, spherical power + (cylindrical power)/2), keratometry, central corneal thickness (CCT), white to white distance (WTW), pupil diameter (PD), anterior chamber depth (ACD), lens thickness (LT), axial lengths (AL) and intereye differences in SE, keratometry, CCT, WTW, PD, ACD, LT and AL were analyzed by independent sample t-tests. Pearson correlation was used for correlations assessment. Partial correlation was used to control for intereye differences in SE.ResultsA total of 156 subjects (79 XT and 77 OT) were collected. Intereye differences in spherical equivalent (SE) (t 2.369, P 0.019), AL (t 3.423, P 0.001), ACD (t 3.782, P Compared with OT subjects, intereye differences in SE, AL, ACD, LT and PD were significantly larger in XT patients and had positive correlation with XT and may be associated with the pathogenesis of XT.

Objective: To investigate the clinical application values of electrocardiogram (ECG) combined with ultrasound cardiogram (UCG) in the differential diagnosis of cardiomyopathy. Methods: A total of 120 patients with cardiomyopathy who were admitted to our hospital were randomly divided into the dilated cardiomyopathy (DCM) group (60 cases) and the ischemic cardiomyopathy (ICM) group (60 cases). Both groups were examined using ECG combined with UCG. The ultrasonic values (aorta, LADI, LVDd, LVESD, RVID, SV, LVEF, LVET, EPSS, E/A, RV6, RV6/RMAX), morphological changes (thin and round left ventricular apex, spherical left ventricle, arch-shaped left ventricle, segmental wall-motion abnormalities (SWMAs), diffuse wall motion abnormalities (DWMAs), paradoxical ventricular wall motion) and heart valve regurgitation (aortic valve, mitral valve, tricuspid valve, pulmonary valve) were compared and analyzed. Results: The degree of chamber enlargement in the DCM group was remarkably higher than that in the ICM group, but the degree of LVEF and aortic enlargement were significantly lower than those in the ICM group (P

Determination of the depth of surface-opening (visible) cracks is of critical importance for evaluating the structural safety of concrete elements. Accurately determining the crack depth wi...

To explore the pharmacological mechanism of Liuwei Dihuang decoction (LDD) for diabetic retinopathy (DR).The potential targets of LDD were predicted by PharmMapper. GeneCards and other databases were used to collect DR genes. Cytoscape was used to construct and analyze network DR and LDD's network, and DAVID was used for Gene Ontology (GO) and pathway enrichment analysis. Finally, animal experiments were carried out to verify the results of systematic pharmacology.Five networks were constructed and analyzed: (1) diabetic retinopathy genes' PPI network; (2) compound-compound target network of LDD; (3) LDD-DR PPI network; (4) compound-known target network of LDD; (5) LDD known target-DR PPI network. Several DR and treatment-related targets, clusters, signaling pathways, and biological processes were found. Animal experiments found that LDD can improve the histopathological changes of the retina. LDD can also increase erythrocyte filtration rate and decrease the platelet adhesion rate (The therapeutic effect of LDD on DR may be achieved by interfering with the biological processes (such as response to insulin, glucose homeostasis, and regulation of angiogenesis) and signaling pathways (such as insulin, VEGF, HIF-1, and ErbB signaling pathway) related to the development of DR that was found in this research.

Overlay systems have been extensively used to extend the service life of concrete bridge decks. There is, however, a lack of systematic studies on nondestructive evaluation (NDE) of concrete bridge decks with various overlays. This study assesses nine NDE methods for evaluation of concrete bridge decks with seven different types of overlays through laboratory concrete specimens. The nine NDE methods are sounding, ultrasonic surface waves (USW), impact echo (IE), ultrasonic testing (UT), impulse response (IR), ground-penetrating radar (GPR), electrical resistivity (ER), half-cell potential (HCP), and infrared thermography (IRT). The seven types of overlays are epoxy, latex modified concrete, silica fume modified concrete, polyester polymer, asphalt with a liquid membrane, asphalt with a sheet membrane, and asphalt without a membrane. Eight concrete specimens with various defects were built and nondestructively evaluated to acquire the detailed information of all embedded defects before placing overlays. One concrete specimen was kept bare as a reference, and the other seven specimens were covered with seven different overlays, respectively. Half of each overlay was bonded to the underlying concrete specimens, whereas the other half was debonded. NDE tests were carried out on the top of overlays. Based on the NDE test results, the applicability of each NDE method for concrete bridge decks with overlays is summarized as follows: (1) GPR and HCP are two effective methods for evaluation of the underlying concrete decks through both bonded and debonded overlays; (2) USW, IE, and UT can image the defects in the underlying concrete decks under bonded overlays, with the exception of the three asphalt overlays; (3) sounding, IR, and IRT can identify overlay debonding; and (4) ER is not effective due to electrical insulation of the overlay materials.

Nondestructive testing methods have been increasingly used to evaluate in situ layered stiffness of pavement systems. However, different testing methods could yield considerable different results, which can bring confusions and difficulties to road agencies when conducting mechanistic-based designs or setting specifications for constructions. This study compares a newly improved multichannel analysis of surface waves (MASW) method and the falling weight deflectometer (FWD) test for estimating in situ moduli of various mechanically and chemically stabilized unpaved road sections, which will serve as foundations for future surface upgrade. The comparisons showed that the trends of MASW moduli generally agree with those of the FWD test for the sections without a geosynthetic layer, but the MASW moduli are much higher than the FWD moduli for the aggregate layers. The discrepancies between the two tests were found to be greatly influenced by the different testing strain levels, which were estimated using the KENLAYER analysis. By combining the MASW and FWD moduli and calculated testing strain levels, in situ modulus reduction characteristics of the various stabilized aggregate layers can also be determined, which provides a better understanding of the in situ mechanistic performances of the different stabilization methods under different traffic loading conditions.

Ultrasonic imaging is a powerful nondestructive evaluation technology for examining the condition of concrete structures through focused images obtained with the Synthetic Aperture Focusing Technique (SAFT). However, its application has been limited to constant-velocity concrete structures; it has not been used with multi-layer concrete structures with different wave propagation velocities, such as bridge decks with overlays. Advancements of SAFT have theoretically allowed ultrasonic imaging for multi-layer concrete structures. In this study, SAFT is combined with the Multi-Layer Delay-And-Sum (MLDAS) method to develop a data analysis method for multi-layer concrete structures. The SAFT-MLDAS method is first verified with the experimental data from a three-layer structure with point-like scatters. The method is then further examined with finite element simulation data from a concrete specimen with a 50-mm overlay, and with experimental data from a concrete specimen with a 38-mm silica fume modified concrete overlay. Results indicate that the SAFT-MLDAS method enables improved ultrasonic imaging for multi-layer concrete structures. Its application in imaging bridge decks with overlays improves the accuracy of the testing results, when the estimation of the shear-wave velocity of each layer is accurate.

Infrared thermography (IRT) has been employed as a non-destructive evaluation (NDE) method to detect delaminations in bridge decks by ASTM standards since 2003. Compared to other NDE methods, IRT is fast in data acquisition and processing. In addition to applications on bridge decks, IRT can be employed to detect defects in other structures such as roadway pavements and tunnel liners. Recent IRT applications on tunnel liners with reflective finishes such as ceramic tiles show that the IRT results can be severely contaminated by infrared reflections of the vehicles and the illuminating systems in the tunnels. In this study, an algorithm is developed to mitigate the contamination caused by the thermal reflections in the IRT results. The reflection is reduced by combining thermal data from multiple thermographs. Perspective projection is employed to map thermal data to the same coordinates if the thermographs are taken with an infrared camera moving in the space. The algorithm is proved to be successful by the results from the lab experiments and field tests. The algorithm can work with IRT data collected by vehicle-mounted infrared cameras to achieve high-speed IRT for tunnel liners with reflective finishes.

This study evaluates three nondestructive testing (NDT) techniques for quality assessment of asphalt pavements. The three NDT techniques examined include an electromagnetic density gauge, a dynamic...

The Magnetic Flux Leakage (MFL) method can be nondestructively used to disclose the location and extent of corrosion or fracture in prestressed strands in concrete structures. In this study, parameters with the greatest effect on the performance of the MFL system are investigated using numerical simulations. The MFL system under study is based on two permanent magnets to magnetize embedded strands and Hall-effect sensors to detect normal magnetic flux leakage. The system is assessed using magnetostatic and transient numerical analysis to effectively simulate the MFL system. Results have been verified by laboratory and field experiments. Both normal and axial Hall-effect sensors are modeled in simulations to better identify magnetic signals at the corrosion zone. The sensor lift-off and the magnetic field masking by lateral reinforcements on nearby pitting corrosion are addressed as two main drawbacks of using MFL systems to detect corrosion in prestressed concrete structures. To provide more details about the flux leakage interference between the pitting corrosion and lateral reinforcements in prestressed concrete structures, linear and oriented magnets/sensor arrays are proposed and analyzed numerically.

Surface waves propagating in layered media inherently possess multimodal dispersion characteristics. However, traditional surface wave testing methods employing measurements at the free surface usually capture only a single apparent dispersion curve, especially when using short geophone arrays common to near surface and geotechnical-scale investigations. Such single-mode or fragmented multimode apparent dispersion curves contain only a fraction of the possible dispersion information, thus limiting the accuracy of inverted profiles. To enable more robust measurement of higher Rayleigh-wave modes, a recently developed hybrid minimally invasive multimodal surface wave method is combined herein with the widely used geotechnical standard penetration test (SPT), which is employed as a practical and ubiquitous downhole source. Upon superimposing surface wave dispersion data for a range of SPT impact depths within the soil, higher modes can be measured more consistently and reliably relative to traditional non-invasive testing methods. As a result, misidentification of multiple dispersion modes can be practically eliminated, significantly improving the accuracy and certainty of inversion results.

Purpose This study implements and demonstrates a deep learning (DL) approach for screening referable horizontal strabismus based on primary gaze photographs using clinical assessments as a reference. The purpose of this study was to develop and evaluate deep learning algorithms that screen referable horizontal strabismus in children's primary gaze photographs. Methods DL algorithms were developed and trained using primary gaze photographs from two tertiary hospitals of children with primary horizontal strabismus who underwent surgery as well as orthotropic children who underwent routine refractive tests. A total of 7026 images (3829 non-strabismus from 3021 orthoptics [healthy] subjects and 3197 strabismus images from 2772 subjects) were used to develop the DL algorithms. The DL model was evaluated by 5-fold cross-validation and tested on an independent validation data set of 277 images. The diagnostic performance of the DL algorithm was assessed by calculating the accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). Results Using 5-fold cross-validation during training, the average AUCs of the DL models were approximately 0.99. In the external validation data set, the DL algorithm achieved an AUC of 0.99 with a sensitivity of 94.0% and a specificity of 99.3%. The DL algorithm's performance (with an accuracy of 0.95) in diagnosing referable horizontal strabismus was better than that of the resident ophthalmologists (with accuracy ranging from 0.81 to 0.85). Conclusions We developed and evaluated a DL model to automatically identify referable horizontal strabismus using primary gaze photographs. The diagnostic performance of the DL model is comparable to or better than that of ophthalmologists. Translational relevance DL methods that automate the detection of referable horizontal strabismus can facilitate clinical assessment and screening for children at risk of strabismus.

This paper presents a study on the application of the multichannel simulation with one-receiver (MSOR) surface-wave testing method for geophysical profiling of soil sites. The MSOR method reverses the roles of source and receiver in the widely-used multi-channel analysis of surface waves (MASW) method. To examine the feasibility and accuracy of utilizing MSOR for soil sites, finite element simulations of MSOR testing are performed for three types of soil profiles containing horizontal interfaces, a vertical fault, and a dipping interface, respectively. The effects of variations in the moving impact locations on the uncertainty and repeatability of the dispersion trends are analyzed for the different soil profiles. Real-world case studies are carried out to examine the equivalency of the MSOR and MASW methods for quantifying surface-wave dispersion trends of soil profiles, as well as the advantages of MSOR testing with embedded geophones to obtain more extensive multimodal dispersion data. From the computational simulations and field case studies, MSOR is demonstrated to be equivalent to MASW testing for practical purposes. In addition, MSOR has the advantages of reduced instrumentation cost, improved portability, enhanced ability to measure multi-mode dispersion curves by utilizing borehole geophones, and the potential for improving efficiency of 3-D stiffness profiling.

Aluminum alloys have found increasing use in space structures, mainly because of their high strength-to-weight ratio and satisfactory corrosion resistance. The work presented in this article is focused on finite element simulation of the failure behavior of aluminum alloy members subjected to an axial compression load and failing in overall buckling mode. The column members were fabricated by extrusion using the relatively new heat-treated aluminum alloy 6082-T6. An accurate finite element model has been developed for the simulation of aluminum alloy columns. The developed finite element model was verified against experimental results and demonstrated that it is capable of accurately predicting the deformed shapes and the ultimate loads of the tested columns. A parametric study was carried out on the stability of aluminum alloy column members failing by overall buckling. A fitting column curve was proposed for aluminum alloy design; it was somewhat more conservative than the column curve from current Chinese code GB50429.

Dynamic modulus has been recognized as an objective and sensitive material property for designing and evaluating pavement systems. To accurately measure the in situ elastic modulus ( E = 2(1 + ν) ρV s 2 ) for nondestructive quality assessment of asphalt pavements, field measurements of density ( ρ ) via an electromagnetic gauge and shear-wave velocity ( V s ) via surface-wave testing were examined for four paving projects covering a range of mixes and traffic loads. A quality control/quality assurance (QC/QA) procedure was developed to correct the in situ moduli at different field temperatures to a common reference temperature using a fitting function from experimental data for QC and using master curves from laboratory dynamic modulus tests for QA. The corrected in situ moduli can then be compared against the maximum moduli for an assessment of the actual pavement performance.

A Minimally-invasive Multimodal Surface Wave (MMSW) geophysical testing method, which is a hybrid of surface and borehole seismic methods, was developed recently by the authors to measure more extensive multi-mode dispersion data and thus improve the accuracy of inversion profiles. The new MMSW method employs a borehole geophone at selected depths to record seismic waves from different source offsets on the soil surface. Presented in this paper is a procedure for estimating a range of optimum geophone depths to capture a given higher mode by the MMSW method. Stiffness matrix and finite-element-based numerical simulations of the MMSW method are performed to identify the relationships between critical geophone depths and apparent cutoff frequencies of higher modes. Specifically, it is shown for increasing velocity profiles that 1) at a given borehole sensor measurement depth, the apparent cutoff frequencies of higher modes increase with mode number, 2) at a given frequency, the critical geophone depth at which a higher mode will first become dominant increases with mode number, and 3) for a given higher mode, the apparent cutoff frequency decreases as measurement depth increases. A preliminary field test is conducted using a vertical geophone placed at five different depths while impacts are applied to the soil surface from 3.66 to 43.89 m from the borehole, with an impact spacing of 3.66 m. Dispersion images from the five geophone depths are superimposed to produce a dispersion image having three modes with improved clarity relative to the surface-only Multichannel Analysis of Surface Waves (MASW) method. A comparison of the experimental and theoretical apparent cutoff frequencies for higher modes is used to validate the theoretical prediction of critical depths by the stiffness matrix method. Matching of experimental and theoretical apparent cutoff frequencies could provide additional optimization constraints to reduce the uncertainty of final inversion profiles.

6082 is a relatively new alloy that currently provides the best combination of properties in 6xxx series alloys. A series of tests was conducted on the stability of heat-treated aluminium alloy 6082-T6 circular tube columns to check the reliability of buckling strength predictions of 6082-T6 alloy circular tube columns using current design rules. First, nine stub columns were tested to obtain stress–strain curves and three parameters of the Ramberg–Osgood expression ( E , σ 0.2 and n ). The experimental stress–strain curves were in good agreement with the Ramberg–Osgood expression, and the mean value of σ 0.2 / n obtained from the tests was close to the Steinhardt assumption. Second, prior to column tests, the initial out-of-straightness of 15 circular tubes was accurately measured. Third, these 15 tubes, with five nominal slenderness ratios varying from 20.4 to 69.6, were tested between two pinned ends under axial compression to obtain failing modes and buckling strengths. Finally, the experimental buckling strengths were compared with the buckling strengths predicted by several current aluminium structure design codes, including the American Aluminium Design Manual (AA), Australian/New Zealand Standard 1664 (AS/NZS), and Eurocode 9 (EC9), as well as the general column curve formulation proposed by Rasmussen and Rondal [13] . These comparisons shows that the AA predictions are too conservative at small slenderness ratios, the AS/NZS predictions are unsafe at large slenderness ratios, the EC9 predictions are conservative, and the Rasmussen–Rondal formulation provides the closest and generally conservative strength predictions.