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This paper presents the concept, design and development of shim (passive damper) to improve the stability for high spindle speed machine operation of face mill tool. The objective of this paper is to learning the dynamic behavior of a face mill tool on VMC with dissimilar types of shims which cover investigation of dynamic motion behavior of the face mill tool, the behavior of different types of shim design and behavior of vibration by using the amplitude ratio method and analysis by a Design Expert. Research work supported computational analysis with Ansys, 35 VMC experimental records and analyzed by ANOVA/Design Expert with different type of shims to observe a dynamic behavior of chatter. It include of the effect of process parameters like Cutting speed (250,200,150 m/min), feed per tooth (0.05, 0.1, 0.15mm/tooth), depth of cut (1.2 mm, 1.0 mm, 0.8 mm), and different types of materials (shims) for face mill tool on VMC, for analyzing the responses like amplitude ratio in X – direction, Y- direction with ANOVA and optimizing for AISI 2062 steel by Design Expert. An experimental methodology was developed using the DOE (Design of experiment) technique. The optimum factorial method was used to design an orthogonal array of four factors having three levels. Here, the main results are based on amplitude ratio, ANOVA analysis and optimization. ANOVA was used to decide the effects of the machining parameters on the vibration amplitude ratio in X; and vibration amplitude ratio in Y. This is useful for evaluating the stability of milling operations via time domain FFT and analyzed by ANOVA. Data are validated by 35 sets of VMC experiments. Physical 35 experiments may be not enough in a view of high level researchers, academicians and industrialist to conclude the use of shim and it need in face mill tool on VMC. Hence here optimization based on optimum factorial method is executed using Design Expert software in which 35experiments and its iterations with 70 populations were used to run the program. It is found that the most critical parameter in this study is the material of Shim. At high cutting parameters carbide shim, at low and medium cutting parameters SS shim are given better results by ANOVA and Optimization of Design Expert also validated by 35 sets of VMC experiments. Hence these shim designs endorse versatile solutions.

PURPOSE The aim of this study was to evaluate and compare early corneal biomechanical changes after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK). METHODS The study comprised 74 patients eligible for refractive surgery, equally allocated to PRK (37 patients) and SMILE (37 patients). Corneal biomechanical properties were recorded and compared between the 2 groups at preoperatively and 3 months after surgery using a dynamic ultra-high-speed Scheimpflug camera equipped with a noncontact tonometer. RESULTS Both procedures significantly affected corneal biomechanical properties at 3 months after surgery. Patients in the PRK group showed significantly better results for deformation amplitude ratio (DA ratio) (P = 0.03), maximum inverse radius (InvRadMax) (P = 0.02), and A2 time (P = 0.03). The mean changes in DA ratio, HC radius, InvRadMax, and Ambrosio relational thickness were significantly higher in the SMILE group in comparison with those of the PRK group (all, P < 0.05). In both groups, change in CCT was significantly correlated with changes in DA ratio and InvRadMax (P < 0.05). CONCLUSIONSS Both SMILE and PRK refractive surgeries significantly altered corneal biomechanical properties but the changes were more prominent after SMILE.

Purpose: To validate and evaluate the use of a new biomechan-ical index known as the Corvis biomechanical index-laser vision correction (CBI-LVC) as a method for separating stable post-LVC eyes from post-LVC eyes with ectasia. Setting: 10 clinics from 9 countries. Design: Retrospective, multicenter, clinical study. Methods: The study was designed with 2 purposes: to develop the CBI-LVC, which combines dynamic corneal response (DCR) pa-rameters provided by a high-speed dynamic Scheimpflug camera (CorVis ST; OCULUS Optikgerate GmbH) and then to evaluate its ability to detect post-LVC ectasia. The CBI-LVC includes integrated inverse radius, applanation 1 (A1) velocity, A1 deflection amplitude, highest concavity and arclength, deformation amplitude ratio of 2 mm, and A1 arclength in millimeters. Logistic regression with Wald forward stepwise approach was used to identify the optimal com-bination of DCRs to create the CBI-LVC and then separate stable from LVC-induced ectasia. Eighty percentage of the database was used for training the software and 20% for validation. Results: 736 eyes of 736 patients were included (685 stable LVC and 51 post-LVC ectasia). The receiver operating char-acteristic curve analysis showed an area under the curve of 0.991 when applying CBI-LVC in the validation dataset and 0.998 in the training dataset. A cutoff of 0.2 was able to separate stable LVC from ectasia with a sensitivity of 93.3% and a specificity of 97.8%. Conclusions: The CBI-LVC was highly sensitive and specific in distinguishing stable from ectatic post-LVC eyes. Using CBI-LVC in routine practice, along with topography and tomography, can aid the early diagnosis of post-LVC ectasia and allow intervention prior to visually compromising progression.

This paper discusses Ree–Eyring fluid’s peristaltic transport in a rotating frame and examines the impacts of Magnetohydrodynamics (MHD). The results deal with systematically (analytically) applying each of the governing equations of Ree–Eyring fluid, the axial and secondary velocities, flow rate due to auxiliary stream, and bolus. The effects of some distinctive variables, such as Hartman number, heat source/sink, and amplitude ratio, are taken under consideration and illustrated through graphs.

OBJECTIVES: The objectives were to measure the effect of stimulus rate and vowel-change direction on the acoustic change complex (ACC) latencies and amplitudes and compare ACC metrics to behavioral measures of vowel-contrast detection for infants tested under the age of 1 year. We tested the hypothesis that the direction of spectral energy shift from a vowel change would result in differences in the ACC, owing to the sensitivity of cortical neurons to the direction of frequency change. We evaluated the effect of the stimulus rate (1/s vs. 2/s) on the infants’ ACC. We evaluated the ACC amplitude ratio’s sensitivity (proportion of ACCs present for each change trial) and compared it to perceptual responses obtained using a visually-reinforced infant speech discrimination paradigm (VRISD). This report provides normative data from infants for the ACC towards the ultimate goal of developing a clinically useful index of neural capacity for vowel discrimination. DESIGN: Twenty-nine infants, nine females, aged 4.0–11.8 months, participated. All participants were born at full-term and passed their newborn hearing screens. None had risk factors for hearing or neurologic impairment. Cortical auditory evoked potentials were obtained in response to synthesized vowel tokens /a/, /i/, /o/ and /u/ presented at a rate of 1- or 2/s in an oddball stimulus paradigm with a 25% probability of the deviant stimulus. All combinations of vowel tokens were tested at the two rates. The ACC was obtained in response to the deviant stimulus. The infants were also tested for vowel-contrast detection using a VRISD paradigm with the same combinations of vowel tokens used for the ACC. The mean age at the time of the ACC test was 5.4 months, while the mean age at the behavioral test was 6.8 months. RESULTS: Variations in ACC amplitude and latency occurred as a function of the initial vowel token and the contrast token. However, the hypothesis that the direction of vowel (spectral) change would result in significantly larger change responses for high-to-low spectral changes was not supported. The contrasts with /a/ as the leading vowel of the contrast pair resulted in the largest ACC amplitudes than other conditions. Significant differences in the ACC presence and amplitude were observed as a function of rate, with 2/s resulting in ACCs with the largest amplitude ratios. Latency effects of vowel contrast and rate were present, but not systematic. The ACC amplitude ratio’s sensitivity for detecting a vowel contrast was greater for the 2/s rate than the 1/s rate. For an amplitude ratio criterion of ≥ 1.5, the sensitivity was 93% for ACC component P2-N2 at 2/s, whereas at 1/s sensitivity was 70%. VRISD tests of vowel-contrast detection had a 71% hit and a 21% false-positive rate. Many infants who could not reach performance criteria for VRISD had ACC amplitude ratios ≥ 2.0. DISCUSSION: The ACC for vowel contrasts presented at a rate of 2/s is a robust index of vowel-contrast detection when obtained in typically developing infants under the age of 1 year. The ACC is present in over 90% of infants tested at this rate when an amplitude ratio criterion of ≥1.5 is used to define a response. The amplitude ratio appears to be a sensitive metric for the difference between a control and contrast condition. The ACC can be obtained in infants who do not yet exhibit valid behavioral responses for vowel change contrasts and may be useful for estimating neural capacity for discriminating these sounds.

This article deals with the behavior of reflection/transmission phenomena on the propagation of SH waves in a corrugated fluid-saturated porous layer sandwiched between heterogeneous viscoelastic a...

Prcis Treatment with topical prostaglandin analogues (PGAs) induces increased corneal compliance in glaucoma eyes measured with a dynamic Scheimpflug analyzer. Purpose The purpose of this study was to evaluate the effect of topical PGAs on the corneal biomechanical properties. Methods We retrospectively studied the biomechanical parameters of 31 eyes of 19 consecutive patients with glaucoma measured using a dynamic Scheimpflug analyzer (Corvis ST) before and after initiation of treatment with topical PGAs. No patients had a history of glaucoma treatment before the study and no other antiglaucoma medication was used during the study period. Nine biomechanical parameters were evaluated before and 61.6±28.5 days (range: 21 to 105 d) after initiation of the treatment. The changes in the corneal biomechanical parameters before and after treatment were analyzed using multivariable models adjusting for intraocular pressure and central corneal thickness. The Benjamini-Hochberg method was used to correct for multiple comparison. Results In multivariable models, PGA treatment resulted in shorter inward applanation time (P=0.016, coefficient=-0.151) and larger deflection amplitude (P=0.023, coefficient=0.055), peak distance (P=0.042, coefficient=0.131), and deformation amplitude ratio at 1 mm (P=0.018, coefficient=0.028). These associations consistently indicated increased corneal compliance (deformability) after PGA treatment. Conclusion Topical PGAs resulted in greater corneal compliance, suggesting that the changes in the corneal biomechanical properties may lead to overestimation of the intraocular pressure-lowering effects.

Quantifying the density contrasts of the Earth’s inner core boundary (ICB) is crucial to understand core-mantle coupling and the generation of the geodynamo. The PKiKP/PcP amplitude ratio is commonly used to obtain the density contrast at the ICB, but its applications are limited by scattered observed data. In this study, we selected the PKiKP and PcP phases reflected at the same region of inner-core and core-mantle boundaries beneath Northeast Asia from different earthquakes for the first time, and the observations suggested that the PKiKP/PcP amplitude ratio is widely scattered. We also compared the PKiKP and PcP amplitudes, which demonstrated that the scatter cannot be attributed only to ICB anomalies but might also arise from raypath differences and heterogeneities throughout the crust and mantle. By fitting the observed PKiKP/PcP amplitude ratio, we obtained a density contrast of approximately 0.65 g cm−3 and a compressional velocity contrast of approximately 0.87 km s−1 at the ICB beneath Northeast Asia. The larger contrast values indicate the possible occurrence of local crystallization occurring at the inner core surface.

In this study, seismic events in the Edirne district (Turkey) and its vicinity have been investigated in order to discriminate earthquakes from quarry blasts. A total of 150 seismic events with Md ≤ 3.5 duration magnitude from a seismic activity catalog between 2009 and 2014 recorded by the Enez (ENEZ), Erikli (ERIK) and Gelibolu (GELI) broadband stations operated by Bogazici University, Kandilli Observatory and Earthquake Research Institute Regional Earthquake-Tsunami Monitoring Center were used in this study. The maximum S-wave and maximum P-wave amplitude ratio of vertical component velocity seismograms, power ratio (Complexity) and total signal duration of the waveform were calculated. Earthquakes and quarry blasts were discriminated using the linear discriminate function (LDF) and back propagation feed forward neural networks, an artificial neural network (ANN) learning algorithm, taking the determination coefficient and variance account values between these parameters into consideration. Eighty-one (54%) of the total 150 seismic events studied were determined to be earthquakes, and sixty-nine (46%) of them were determined to be quarry blasts. The LDF and ANNs methods were applied to the data in Edirne and its vicinity using a pair of parameters and were compared to each other for the first time. The accuracy of the methods are 95% and 99% for LDF and ANNs, respectively.

This paper presents a novel design for a high resolution microelectromechanical systems (MEMS) technology based resonant gyroscope using the mode-localization effect in weekly coupled resonators (WCRs) as a mechanism for sensing the input angular rate. The design consists of a single proof mass with two three degree-of-freedom (3-DoF) WCRs systems attached on either side. The MEMS gyroscope is designed according to the microfabrication constraints of the foundry process, silicon-on-insulator multi-user MEMS process (SOIMUMPs). The shift in the resonance frequency values, amplitude ratios of the WCRs, and amplitude ratios difference of two sets due to electrostatic stiffness perturbation, corresponding to the input angular rotation, are discussed as an output metric for the measurement of angular rate. The results show that the amplitude ratio difference as an output metric allows achieving a linear output response and large dynamic range in comparison to the shift in the amplitude ratio and resonance frequency in 3-DoF WCRs in a single set. The dynamic range and resolution of the MEMS gyroscope in terms of maximum allowed resonators amplitude and the noise floor is discussed. The proposed MEMS gyroscope design has a sensitivity of 62830 ppm/°/ $s$ based on a difference in the amplitude ratios of resonators in two 3-DoF WCRs systems and a dynamic range of ±100 °/s. The resolution of the MEMS gyroscope is $31.09\times 10^{-6\circ }$ /s which is significantly higher than existing MEMS gyroscopes and is comparable to traditional bulky ring laser gyroscopes. This high resolution makes the proposed MEMS gyroscope design suitable for use in applications such as earth rotation rate measurement for gyrocompassing and high precision robotics.

—The structure of seismic wavefield at distances close to antipodal is analyzed using two numerical methods—DSM and AXISEM—for calculating full waveforms. The obtained empirical estimates of the amplitude ratio of PKIIKP and PKIKP phases indicate that the S-wave velocity in the upper 40 km of the inner core may not be higher than 3.1 km/s. The properties of the PKPc-dif waves suggest a lower P-wave velocity in the lower 100 km of the outer core.

This paper demonstrates the feasibility of employing mode localized mass sensing in coupled MEMS resonators for ultra-fine particulate detection applications. The potential benefits of this approach include higher parametric sensitivity and intrinsic common mode rejection as compared to the resonant frequency shift-based detection approach. Weakly coupled MEMS resonators demonstrated in this paper demonstrate sensitivity to fine particulates and a significant improvement in mass sensitivity for particulate quantification by employing an amplitude ratio shift output metric.

In a spectrum ranging from a subatomic particle which is approximately 10^(-26) m, to the observable universe, which is of the order of 10^(26) m, airborne ultrafine particles have a diameter of less than 100nm. The adverse impact of these ultrafine airborne particles on human health has been the focus of numerous clinical studies, including respiratory and cardiovascular diseases. Empirical results of the clinical studies suggest that it is essential to map the emission sources of these ultrafine airborne particles to monitor and regulate them. Recognizing the cumbersome nature of the traditional optical methods and their inability to count individual particles below 100nm due to diffraction limit, new approaches are being researched for sensing these ultrafine particles. In recent decades, Richard Feynman’s (1961) vision of building minuscule machines has been translated to a reality using Microelectromechanical Systems (MEMS) Technology. Integration of miniature electrical and mechanical components fabricated using integrated circuit batch processing techniques is achievable utilising MEMS Technology. As a result, MEMS devices have witnessed exponential growth over the last decade in various fields and have had a significant impact on the field of sensors and sensor systems. This thesis investigates the potential of mode localisation in MEMS devices for sensing ultrafine particles as an approach towards future sensor technologies for gravimetric sensing that could eventually be deployed as part of the emerging Internet-of-Things (IoT) paradigm. Furthermore, this thesis aims to examine the influence of “real-world” conditions during the field deployment of mode localised MEMS resonators for sensing ultrafine particles. In that regard, weakly coupled MEMS resonators utilising mode localisation have been proposed as an alternative to resonant frequency MEMS sensors due to their increased sensitivity and first-order common-mode rejection to variations in temperature. This thesis presents a number of contributions to the design of coupled MEMS resonators for sensing ultra-fine particles. Firstly, piezoelectrically transduced, coupled MEMS resonators are modelled by numerical simulations, including finite element simulations for modal analysis. Secondly, the coupled MEMS resonators are designed and fabricated using silicon-on-insulator (SOI) wafers via the PiezoMUMPs process offered by MEMSCAP, Inc. Thirdly, critical aspects of the MEMS mass sensors such as sensitivity, stability, and common-mode rejection are analysed through laboratory experiments. These experiments involve interfacing the MEMS element to a source of ultrafine particles and observing amplitude ratio as the output electrical signal. The ultrafine particles generated in the laboratory for this experimental execution include polystyrene latex nanoparticles and diesel soot nanoparticles. The results highlight the three orders of magnitude enhancement in relative mass sensitivity for mode-localised MEMS sensors over the resonant frequency shift-based approach. Notably, the resolution of the mode localised MEMS sensors is explored by implementing a single oscillator for the coupled MEMS resonators in the array. Following this, the coupled MEMS resonators are subjected to temperature variations to demonstrate their insensitivity to temperature. In addition, an investigation of the coupled MEMS sensor lifetime by depositing particles on both resonators to achieve mass balancing has been addressed. Finally, suggestions for future work are presented to optimise the accuracy of the mode localised MEMS sensors towards future miniaturisation and deployment as population-based exposure assessment tools., British Council (UKIERI), BP, Lundgren Trust, Fletcher Bursary, CAPE Acorn Research Award

Background/AimsWe aimed to investigate the refractive changes in the posterior corneal surface in keratoconus (KC) associated with wearing spherical corneal rigid gas-permeable contact lenses (corneal GPs) with apical touch or three-point touch fitting and the effect of spherical corneal GPs on corneal biomechanics.MethodsPatients with KC wearing corneal GPs every day without facing complications were enrolled as a single group. Corneal tomographic data were obtained using a three-dimensional anterior segment optical coherence tomography from the same eye with and without corneal GPs. Dioptric data from the central 3-mm zone of the posterior corneal surface were decomposed into spherical, regular astigmatism, asymmetry and higher-order irregularity components using Fourier harmonic analysis. The corneal biomechanical indices were deformation amplitude ratio within 2 mm, integrated radius, stiffness parameter at first applanation and linear Corvis Biomechanical Index. Correlations between the difference in Fourier indices with and without corneal GPs and the corneal biomechanical parameters were analysed.ResultsThirty-two eyes of 32 patients with KC were enrolled. Spherical, regular astigmatism and asymmetry components were significantly smaller with corneal GP wear than without the wear (all pConclusionCorneal biomechanical properties of KC were correlated with posterior corneal surface flattening induced by wearing corneal GPs on the spherical components. This effect is greater in biomechanically weaker corneas.

A novel tunable vector-sum filtering power divider (FPD) with arbitrary output phase difference is proposed. It is constructed by a tunable FPD [which has reconfigurable in-/out-of-phase output and arbitrary power division ratios (PDRs)] on the left and a wideband branch-line coupler (BLC) on the right. The output wave from the left FPD forms two orthogonal vectors at each output port of the BLC. The orthogonal vectors are summed up and result in a new vector with phase that is purely determined by the amplitude ratio of the orthogonal vectors. As a result, the phase difference between the new vectors at the outputs of the BLC can be continuously tuned by adjusting the PDR of the left FPD. Detailed theoretical analysis has been given. It shows that the phase difference between the output ports can be flexibly tuned from 0 °C to 360 °C within the full frequency tuning range.

Purpose: To evaluate the possibility of registration of the photopic negative response (PhNR) without pupil dilatation in healthy individuals to determine the dysfunction of neurons of the inner retina.Methods: 12 healthy persons (23 eyes) aged 24 to 40 years were examined. Refraction anomalies did not exceed 0.5 diopters. A PhNR was evaluated in photopic ERGs recorded on a blue background with red flashes of four intensities (0.375, 0.75, 1.5, 3.0 cd·s/m2) using the RETIport/scan21 (Roland Consult). First, ERG was recorded with the natural pupil (3.5 ± 0.2 mm). Then, the recording was repeated after drug mydriasis (average pupil size 8.7 ± 0.1 mm).Results. In eyes with natural pupil width, in comparison with drug mydriasis, PhNR amplitudes in responses to weakest stimuli (0.375 cd·s/m2) were significantly reduced. The effect of pupil size on the PhNR amplitude from a baseline was virtually absent in responses to higher strength flashes. This phenomenon can be associated with an irregular distribution of light over the retina with small pupil size, the effect of which is maximal in responses to weak flashes. For the maximal brightness stimuli (3.0 cd·s/m2), differences were found between groups of non-dilated and dilated pupils in the amplitudes of the b-wave and PhNR from the b-peak, which may reflect a decrease in the number of stimulated photoreceptors during ganzfeld stimulation when the pupil is not dilated.Conclusion. The effect of pupil size on the parameters of the PhNR was most significant in the ERG with minimal flash strength and it decreases in responses to flashes of higher brightness. If it is necessary to record the ERG without drug mydriasis, especially in screening studies, it is recommended to limit the protocol to estimate the PhNR from a baseline in responses to maximal flashes, and use the relative parameter — the amplitude ratio of PhNR/b. Keywords: photopic negative response, electroretinography, pupil width

Accurate tidal height data for the seas around Antarctica are much needed, given the crucial role of these tides in the regional and global ocean, marine cryosphere, and climate processes. However, obtaining long-term sea level records for traditional tidal predictions is extremely difficult around ice-affected coasts. This study evaluates the ability of a relatively new tidal-species-based approach, the complete tidal species modulation with tidal constant corrections (CTSM + TCC) method, to accurately predict tides for a temporary observation station in the Ross Sea, Antarctica, using a record from a neighbouring reference station characterised by a similar tidal regime. Predictions for the “mixed, mainly diurnal” regime of Jang Bogo Antarctic Research Station (JBARS) were made and evaluated based on summertime (2017; and 2018 to 2019) short-term (25 h) observations at this temporary station, along with tidal prediction data derived from year-long observations (2013) from the neighbouring “diurnal” regime of Cape Roberts (ROBT). Results reveal the CTSM + TCC method can produce accurate (to within ∼5 cm root mean square errors) tidal predictions for JBARS when using short-term (25 h) tidal data from periods with higher-than-average tidal ranges (i.e. those at high lunar declinations). We demonstrate how to determine optimal short-term data collection periods based on the Moon's declination and/or the modulated amplitude ratio and phase lag difference between the diurnal and semidiurnal species predicted from CTSM at ROBT (i.e. the reference tidal station). The importance of using long-period tides to improve tidal prediction accuracy is also considered and, finally, the unique tidal regimes of the Ross Sea examined in this paper are situated within a wider Antarctic tidal context using Finite Element Solution 2014 (FES2014) model data.

Purpose: A 6-month evaluation of the topographic and biomechanical changes induced by corneal collagen cross-linking (CXL) in keratoconic eyes using Pentacam and Corvis ST. Design: Longitudinal prospective case series. Methods: In this study, 67 eyes of 67 patients with progressive keratoconus (KCN) treated with “Epithelium-off” CXL were evaluated. Patients with stages 1 or 2 of KCN and a corneal thickness of at least 400 μm at the thinnest point were included. Standard ophthalmologic examinations were carried out for all patients. The topographic and biomechanical measurements of the cornea were obtained by Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and 6-month postoperatively. Results: The mean age of the participants was 21.68 ± 4.23 years. There was significant difference in mean spherical equivalent (SE) before and 6 months after CXL. Uncorrected and best corrected visual acuity improved postoperatively, although not statistically significant. The mean and maximum keratometry showed a significant decrease 6 months after CXL (0.93 ± 0.38 D and 1.43 ± 0.62 D, respectively p Conclusion: Analyzing biomechanical changes after corneal cross-linking can provide basis for efficient KCN treatment. Corvis ST parameters demonstrated changes in corneal biomechanical characteristics indicative of stiffing after CXL.

To determine whether normal to supernormal 30-Hz flicker ERGs are associated with visual function and prognosis in patients with central retinal artery occlusion (CRAO).A total of 133 patients diagnosed with unilateral acute non-arteritic CRAO by examination with electroretinography (ERG) were examined. Thirty-hertz flicker ERG amplitudes were analyzed according to the severity of CRAO, and their correlation with visual function and prognosis was assessed. All patients were categorized into one of three groups according to the flicker ERG amplitude ratios between affected and fellow eyes: ≥ 110%, supernormal; 90-110%, normal; and 90%, subnormal.Thirty-hertz flicker ERG parameters differed significantly according to the severity of retinal ischemia, i.e., between incomplete versus complete CRAO: mean amplitude (55.89 ± 24.38 45.41 ± 23.47 μV, P = 0.029), amplitude ratio (76.1 ± 23.1% 58.7 ± 25.7%, P 0.001), and proportion of normal to supernormal flicker ERGs (30.5% 12.4%, P .001). One-month and final follow-up visual function and prognosis were better in the normal to supernormal flicker ERGs: 1 month BCVA (1.55 ± 0.65 2.05 ± 0.61 logMAR, P .001), final BCVA (1.32 ± 0.79 1.97 ± 0.68 logMAR, P .001), 1-month VA improvement (- 0.50 ± 0.47 - 0.10 ± 0.29 logMAR, P .001), and final VA improvement (- 0.74 ± 0.61 - 0.18 ± 0.37 logMAR, P .001).Normal to supernormal 30-Hz flicker ERG changes in eyes with CRAO are associated with the milder severity of retinal ischemia and showed better visual function and outcome than the subnormal ERG group.

PRECIS Corvis ST Tonometry and Ocular Response Analyzer (ORA) measurements were conducted in primary open-angle glaucoma and normative subjects. Many parameters were significantly correlated, however, the strengths were weak to moderate. PURPOSE Reichert ORA parameters are derived from pressure information following the application of air-jet, whereas detailed structural observation can be made using the Corneal Visualization Scheimpflug Technology instrument (CST). The purpose of the study was to investigate the association between CST measurements and ORA measured corneal hysteresis (CH). METHODS Measurements of CST, ORA, axial length, average corneal curvature, central corneal thickness (CCT) and intraocular pressure with Goldmann applanation tonometry were carried out in 104 eyes of 104 patients with primary open-angle glaucoma and 35 eyes from normative subjects. The association between CST and ORA parameters was assessed using linear regression analysis, with model selection based on the second order bias corrected Akaike Information Criterion index. RESULTS Deformation amplitude ratio (corneal softness, R=-0.51), SP A1 (corneal stiffness, R=0.41), and Inverse Radius (integrated area under the curve of the inverse concave radius, R=-0.44) were significantly correlated with CH (P

PURPOSE To evaluate the safety and efficacy of photorefractive intrastromal corneal crosslinking (PiXL) for the treatment of low myopia using the epithelium-on approach with supplemental oxygen. SETTING The Eye Foundation, Coimbatore, India. DESIGN Prospective interventional case series. METHODS Myopic nonectatic eyes underwent PiXL using the Mosaic system. Ultraviolet-A (UV-A) irradiation of 365 nm wavelength was delivered in an accelerated (30 mW/cm) pulsed approach to provide a total fluence of 15 J/cm. Supplemental oxygen (concentration greater than 95%) was provided to increase the efficacy of the epithelium-on approach during the UV-A irradiation. Efficacy was determined by improvement in mean refractive spherical equivalent (MRSE), uncorrected distance visual acuity (UDVA), and keratometric flattening. Safety was determined by loss of lines of corrected distance visual acuity, endothelial cell loss, and adverse events. RESULTS Fifty eyes of 26 patients with a mean age of 22.73 ± 3.74 years were included. A significant improvement in UDVA from baseline (logarithm of the minimum angle of resolution [logMAR] 0.63 ± 0.25) was noted at the 3-month (logMAR 0.08 ± 0.15) and 6-month (logMAR 0.13 ± 0.18) follow-up visits (P < .001). Significant keratometric flattening from baseline was noted at all follow-up visits (P < .001). No significant endothelial cell loss or adverse effects were noted. A significant correlation was noted between the change in MRSE and preoperative corneal biomechanics (deformation amplitude ratio, P = .029). CONCLUSIONS Transepithelial PiXL with supplemental oxygen might be a safe and effective approach for reduction of myopia. The change in MRSE and keratometric flattening was greater in comparison with earlier protocols, including the epithelium-off approach.

The problem of wave propagation in the generalized theory of micropolar thermoelasticity under the Green–Lindsay model has been investigated. We have investigated the reflected dilatational and shear waves due to incident waves at a plane-free surface of generalized micropolar thermoelastic materials. The amplitude and energy ratios corresponding to the reflected coupled dilatational and coupled shear waves are derived using boundary conditions at the free surface. These ratios are also computed numerically for a particular model. Note that there are critical angles for the incident shear wave.

In this paper, the gain characteristics of the sequential rotating array are theoretically analyzed. The cell spacing d, the unit polarization characteristic AR, the feeding amplitude ratio a and the feeding phase difference Δψ all affect the beam shape of the array, thus affecting the gain of the array. In this paper, the quaternary array is taken as an example to analyze the effects of the polarization characteristics, feed amplitude ratio and feed phase difference of the antenna elements in the sequential rotating array on the gain characteristics of the antenna array.

In this work, the properties of a two-tone signal driven concurrent power amplifier (CPA) are analyzed extensively. Firstly, the characteristics of two-tone signals are discussed to explain the nonlinearity and efficiency of two-tone signal driven CPA. Secondly, a method of how to solve the efficiency of a two-tone signal driven CPA is proposed in this paper with a detailed calculation procedure and complete theory. Finally, a general empirical expression to calculate the drain efficiency (DE) of CPA versus the frequency ratio and the amplitude ratio of the two carriers is proposed. Simulation results and experimental verifications are given to validate the proposed analytical formulation to predict the efficiency of CPAs when driven with balanced or imbalanced two-tone signals.

This paper presents a mode pair extraction method for a bell-type structure that employs a generated beat response signal. Due to the occurrence of small asymmetries in the bell structure, a mode pair can be observed on the circumference. Each mode in the pair has very close frequencies and interference between these frequencies produces beats. Beats are a very interesting acoustics phenomenon in the bell sound. Controlling the beat characteristics requires extraction of a mode pair after the bell is cast. The conventional modal test needed excitation force and response signals at several points. On the contrary, the proposed method requires only the beat response measured at two points on the circumference. This method applied the theory of shell-of-revolution and measured the amplitude ratios of the beat wave’s peak and the valley. The position of the nodes and anti-nodes of the mode pair was determined using the amplitude ratio and the auto-spectrum. The validity of the new method was verified by comparing the experimental results with those of the multi-point test method. Moreover, this method is much simpler and faster than the conventional ones.

The Whakaari/White Island volcano, located ~ 50 km off the east coast of the North Island in New Zealand, has experienced sequences of quiescence, unrest, magmatic and phreatic eruptions over the last decades. For the last 15 years, seismic data have been continuously archived providing potential insight into this frequently active volcano. Here we take advantage of this unusually long time series to retrospectively process the seismic data using ambient noise and tremor-based methodologies. We investigate the time (RSAM) and frequency (Power Spectral Density) evolution of the volcanic tremor, then estimate the changes in the shallow subsurface using the Displacement Seismic Amplitude Ratio (DSAR), relative seismic velocity (dv/v) and decorrelation, and the Luni-Seismic Correlation (LSC). By combining our new set of observations with the long-term evolution of earthquakes, deformation, visual observations and geochemistry, we review the activity of Whakaari/White Island between 2007 and the end of 2018. Our analysis reveals the existence of distinct patterns related to the volcano activity with periods of calm followed by cycles of pressurization and eruptions. We finally put these results in the wider context of forecasting phreatic eruptions using continuous seismic records.

The mode localization phenomenon is an effective technique to enhance sensor sensitivity, and some low noise floor mode-localized sensors, including accelerometers, mass sensors, and electrometers, have been successfully realized. To further improve the performance of the mode-localized accelerometer, we report a microelectromechanical system mode-localized accelerometer based on 4-degree of freedom (DoF) weakly coupled resonators (WCRs) with a stress-relief structure eliminating the thermal stress generated during the silicon-on-glass fabrication process. Experimental results show that compared with the state-of-the-art 3-DoF mode-localized accelerometer (4.40 g$^{-1}$), the amplitude ratio-based sensitivity of the proposed accelerometer (119.36 V$\\cdot$g$^{-1}$) is improved by 2612%. Moreover, the noise floor is 0.64 $\\mu$g$\\cdot$Hz$^{-1/2}$ from 0.01 to 3 Hz under the closed-loop circumstance. To the authors best knowledge, this is the lowest measured noise floor for mode-localized accelerometers.

Past examinations on the deducing the (bridge frequency (B-f) in an indirect way from the dynamic reaction of a moving vehicle were centered fundamentally around the possibility of the procedure. Not many examinations are done to contemplate the impacts of important unique factors of the framework on the vertical reaction of the moving vehicle. To comprehend such a space, the important factors will be analyzed not just for assessing their comparative impact, however for enhancing the likelihood of effectively recognizing the B-f of requirement. Different amplitude ratio (AR’s) will be characterized and communicated as far as the important factors, which serve as valuable markers for assessing the likelihood of effective recognition of the B-f from the moving automobile. For the case examined, where it is possible that a couple of B-f to be indicated, it was indicated that the preliminary AR assumes a job that’s a higher priority when compared to others in fruitful recognizable proof of the B-f. Recommendations are done for utilization of strategy in the discipline.

Objective: Vestibular-Evoked Myogenic potential (VEMP) is a non invasive test for vestibular function. It is a series of electrical waves that are generated by vestibular pathway in response to loud acoustic stimulation. It can be recorded from surface electrodes placed over muscles and according to the site of recording there are two types cervical VEMP and ocular VEMP. The primary goal of the present study is to compare cervical evoked myogenic potential (cVEMP) findings in normal hearing children and adults.Materials and Methods: This study included 60 subjects of normal hearing. They were selected from relatives; friends and relatives of patients attending Audiology Unit of Alzahraa University Hospital. 30 were children in the age range of 5-15 years and 30 were adults in the age range of 20-40 years. All subjects were submitted to cVEMP (air-conducted sound). Amplitude, latencies, asymmetry amplitude ratio and threshold were measured.Results: There was statistically significant difference in latencies and amplitudes and no statistically significant difference in asymmetry ratio of cVEMP responses between children and adults. There was no statistically significant difference in threshold between right and left ears in adult and children but there was statistically significant difference between the two groups as regard cVEMP threshold.Conclusion: cVEMPs responses in children have shorter latencies and lower thershold than adult responses, which should be considered in interpretation of cVEMP responses in children. Normative data for different age groups should be collected as cVEMPs responses, as age has a significant effect on them.

The capability to discriminate low‐magnitude earthquakes from low‐yield anthropogenic sources, both detectable only at local distances, is of increasing interest to the event monitoring community. We used a dataset of seismic events in Utah recorded during a 14‐day period (1–14 January 2011) by the University of Utah Seismic Stations network to perform a comparative study of event classification at local scale using amplitude ratio (AR) methods and a machine learning (ML) approach. The event catalog consists of 7377 events with magnitudes MC ranging from −2 and lower up to 5.8. Events were subdivided into six populations based on location and source type: tectonic earthquakes (TEs), mining‐induced events (MIEs), and mining blasts from four known mines (WMB, SMB, LMB, and CQB). The AR approach jointly exploits Pg‐to‐Sg phase ARs and Rg‐to‐Sg spectral ARs in multivariate quadratic discriminant functions and was able to classify 370 events with high signal quality from the three groups with sufficient size (TE, MIE, and SMB). For that subset of the events, the method achieved success rates between about 80% and 90%. The ML approach used trained convolutional neural network (CNN) models to classify the populations. The CNN approach was able to classify the subset of events with accuracies between about 91% and 98%. Because the neural network approach does not have a minimum signal quality requirement, we applied it to the entire event catalog, including the abundant extremely low-magnitude events, and achieved accuracies of about 94%–100%. We compare the AR and ML methodologies using a broad set of criteria and conclude that a major advantage to ML methods is their robustness to low signal‐to‐noise ratio data, allowing them to classify significantly smaller events.

Magma opening new fluid pathways through the crust can generate migrating seismic sources following the trail of the magma. By using Seismic Amplitude Ratio Analysis (SARA), it is possible to detect this seismic migration simply from the amplitudes of continuous data recorded at different stations in a network, without having to do any picking of seismic phases. In this study, we present a modified method – Red-flag SARA, which adapts SARA for real-time monitoring. Red-flag SARA provides a quantitative tool to analyse amplitude ratios between stations in a network and detect temporal changes in these ratios. Since such changes imply seismic source location variations, Red-flag SARA is a handy tool during seismic crises to quickly answer the question of whether seismic activity, and therefore magma, is migrating or not. We tested Red-flag SARA on synthetic data and validated it using real data from two volcanoes – Piton de la Fournaise, Reunion Island, and Gede, Indonesia, for three scenarios: 1) magma migration ending as intrusion, 2) migration leading to eruption and 3) a burst of seismicity with no magma migration. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Published version

Intriduction. Proper investigation of the abnormalities in heart sounds is known to provide vital clinical information that can assist in the diagnosis and management of cardiac conditions in the newborns. Systematic studies were conducted in various populations by using electronic cardiac auscultation and the ratio of the amplitude of first heart sound S1 to the amplitude of second heart sound S2 could provide a non-invasive assessment of cardiac activity. It has been proved that these indicators can be used to reflect the relationship between the cardiac contractility and the peripheral resistance and to evaluate the relative workload status of the left and right ventricles, respectively.Objective. The primary objective of this work was to devise some indicators based on relative values of the neonatal electronic phonocardiograms for evaluating the differences between them in newborns of different gestational age and for evaluating the neonatal cardiac heart activity.Materials and methods. 343 newborn babies of gestational age 26 to 42 weeks were examined. In the group of examined children, no structural defects of the heart and large vessels were found prenatal or after birth as well as no pathological changes were detected using traditional auscultation. The following study using electronic auscultation was performed by the digital stethoscope Thinklabs Model ds32a + at five standard listening points. The sound recording was performed on the Sony-ICD-UX71 digital voice recorder. The analysis of received phonocardiograms was carried out with the help of the developed computer program "Hearttone D". Results. The amplitude ratio of the first heart sound to the second heart sound (s1_a_max/ s2_a_max), the width ratio of the first heart sound to the second heart sound (s1_width/s2_width) of the neonates were measured, calculated and analyzed. Revealed significant differences between these indicators in newborns of different gestational age.Newborn babies with a gestational age of 33-35 weeks had significant differences in s1_a_max/ s2_a_max in the presence of a patent ductus arteriosus. Newborns with a patent ductus arteriosus had higher values of this parameter.Conclusions. There are significant differences in the electronic phonocardiograms of newborns from different gestational age groups. Newborn babies with a gestational age of 33-35 weeks had significant differences in s1_a_max/ s2_a_max in the presence of a patent ductus arteriosus. The obtained results indicate that further research is required to gain a better understanding of the electronic auscultation of the heart for the early cost-effective screening and control of the course of cardiovascular diseases in newborns.

To investigate whether visual acuity improvement achieved after surgical treatment for macular hole (MH) can be predicted by preoperative multifocal ERG (mfERG) central/peripheral amplitude ratio. Thirty patients with unilateral MH were included. Evaluations with comprehensive ophthalmological examination including best-corrected visual acuity (BCVA) were performed at baseline and 1, 3, 8, 24 and 48 weeks after surgery, while mfERG (Diagnosys LLC; 61 hexagons—30°) and spectral-domain optic coherence tomography (sOCT—Heidelberg Engineering) were performed at baseline and 2 months after surgery. mfERG results are shown by means of the ratio between the amplitudes’ average from rings 1 and 2 (central) and rings 4 and 5 (peripheral): the P1 ratio. mfERG data from 20 normally sighted age-matched subjects was used for comparison. A macular hole index (MH index) was defined as the quotient between hole height and base measured on OCT. Twenty-six patients finished the 48-week follow-up. Mean ± SE (logMAR) preoperative BCVA was 0.93 ± 0.22 and improved in 0.25 ± 0.07 at 48 weeks. mfERG P1 ratio was reduced at baseline and increased significantly after surgery. A significant correlation was observed between preoperative P1 ratio and BCVA gain at week 8 (r = −0.42; P = 0.033). There was no significant correlation between preoperative MH index and postoperative BCVA (P > 0.05). Retinal function assessed using the ratio between central and peripheral mfERG responses might be used as predictor of visual acuity outcome after macular surgery for MH.

The characteristics of the rotational components of strong earthquake ground motion and their effects on structural response are rarely considered. A reduced order parametric model is used to investigate the effects of the rotational ground motions upon buildings, which includes the influence of Soil-Structure Interaction. An indirect method of extracting rotational ground components using a multi-station procedure is employed. Ground accelerogram data recorded from the SMART-1 array in Taiwan for three different events are used. Over 3 million system/ground motion cases are analysed in this extensive parametric study. The results show that the rotational ground motion can significantly affect the displacement and acceleration responses of certain structures. The impact of the rotational ground motion depends principally on the amplitude ratio of the rotational to horizontal ground motion and the phase difference content at the structural system’s frequencies.

We propose a blind digital modulation format identification (MFI) method for coherent optical fiber communication systems. Based on the evaluation of differential phase distribution ratio (DPDR) and average of amplitude ratio (AAR), a monitoring factor ${R}$ , the product of DPDR and AAR, is defined to distinguish whether the signal modulation format is QPSK, 16-QAM, or 64-QAM. Simulation and experimental results demonstrate that the proposed MFI can perform an identification when the OSNR of the incoming signal is greater than 12 dB. The proposed method needs no extensive training data sets and can tolerate residual chromatic dispersion (−210–210 ps/nm) and phase noise.

In-depth understanding of water management is essential for the optimization of the performance and durability of polymer electrolyte fuel cells (PEFCs). Neutron imaging of liquid water has proven to be a powerful diagnostic technique, but it cannot distinguish between ‘legacy’ water that has accumulated in the system over time and ‘nascent’ water recently generated by reaction. Here, a novel technique is introduced to investigate the spatially resolved water exchange characteristics inside PEFCs. Hydro-electrochemical impedance imaging (HECII) involves making a small AC-sinusoidal perturbation to a cell and measuring the consequential water generated, using neutron radiographs, associated with the stimulus frequency. Subsequently, a least-squares estimation (LSE) analysis is applied to derive the spatial amplitude ratio and phase shift. This technique provides a complementary view to conventional neutron imaging and provides information on the source and ‘history’ of water in the system. By selecting a suitable perturbation frequency, HECII can be used to achieve an alternative image ‘contrast’ and identify different features involved in the water dynamics of operational fuel cells.

We have previously shown that the amplitude of the mfERG response obtained to a single (large) hexagon is significantly smaller than that obtained when summating all the mfERG responses evoked to an array of 7–61 hexagons covering the same retinal area. The purpose of this study was to confirm our initial findings in normal subjects of different ages and in selected patients. Binocular mfERGs (1, 7, 19, 37 and 61 hexagon arrays; Espion V6.0.54 Diagnosys LLC) were recorded from 40 normal subjects (25 aged 18–25, and 15 aged 3–12). Individual mfERG waveforms evoked in response to the multi-hexagon arrays (7, 19, 37 and 61) were summated, and the amplitude of the resulting composite mfERG waveform was compared to that measured in the response evoked to the single (large) hexagon stimulus to yield the amplitude ratio (i.e., 7:1 X100, 19:1X100, etc.). In normal subjects, the 7:1 ratio was 119.5 ± 9.2%, a value that gradually decreased to reach 109.4 ± 20.6% with the 61:1 ratio and a finding that was similar across all ages. The present study indicates a significant enhancement in amplitude of the summed mfERG composite waveform evoked to the 7 hexagon stimulus array (and to a lesser extent to the 19, 37 and 61 stimuli) compared to the 1 hexagon array, possibly mediated through the retinal lateral pathway (horizontal or amacrine cells), a claim that awaits confirmation. Preliminary results obtained from patients treated with Plaquenil suggest that this new method of mfERG analysis might probe a feature of macular function different from that investigated with the more usual method of mfERG ring ratio.

Spalling is a main fatigue failure type of ball bearings. Vibration features of the bearing will be changed during the spalling propagation, which can be utilized to identify the spalling damage level. In this study, a new spalling propagation assessment algorithm dependent on the spectrum amplitude ratio and statistical features is established to identify the spalling damage location and level. The damage level is determined by the test fault samples in the listed test works. The spectrum amplitude ratio based on the bearing fault frequencies and spectrum amplitudes is applied to identify the damage location. 25 statistical features of the time-domain vibration signal are calculated. Pearson correlation coefficient (PCC) is used to determine the effective ones in the 25 statistical features presented by the previous works. The effective statistical features are applied to estimate the damage level. The test data given by the previous work in the list reference is utilized to verify the developed spalling propagation assessment algorithm. The results indicate that the established method can give a new approach to identify the spalling damage location and level of a ball bearing.

The inter-frequency amplitude ratio (IFAR) is the ratio of the amplitude of 1000-Hz tone-burst evoked ocular vestibular evoked myogenic potential (oVEMP) to the 500 Hz tone-burst evoked oVEMP. Since IFAR is an amplitude-based parameter, and the amplitudes of oVEMP for different frequencies are differentially affected by ageing, IFAR could potentially be affected by the ageing process. Therefore, we aimed to examine the effects of ageing on the IFAR of oVEMPs.Multiple static groups comparison.We recorded oVEMPs for 500 Hz and 1000 Hz tone-bursts from 270 healthy individuals, each included in one of the six age groups.The IFAR was significantly larger in the ≥60 years age group than the age groups up to 49 years. Furthermore, the IFAR in the 50-59 years age group was significantly larger than all the other age groups up to 39 years. There was a significant positive correlation between age and IFARs (IFAR, a sensitive tool in the test battery for the diagnosis of Meniere's disease, is affected even in healthy individuals due to ageing; hence its cautious interpretation is recommended when evaluating adults50 years of age who are suspected of having Meniere's disease.

BackgroundTo explore the relationship between corneal biomechanical parameters and corneal sublayer thickness using corneal visualization Scheimpflug technology (Corvis ST) and ultrahigh-resolution optical coherence tomography (UHR-OCT) in clinical and suspected keratoconus and normal eyes.MethodsCross-sectional prospective study. A total of 94 eyes of 70 participants were recruited. Twenty five eyes of 19 keratoconus patients, 52 eyes of 34 patients showing high risk of developing keratoconus according to the Belin/Ambrosio Enhanced Ectasia Display, and each eye of 17 normal subjects were enrolled. All participants underwent Corvis ST, Pentacam, and UHR-OCT examinations at the same time. Stiffness parameter A1 (SP-A1), deformation amplitude ratio (DA ratio), and other biomechanical parameters were recorded using Corvis ST. The vertical and horizontal thickness profiles of central 3 mm corneal epithelium, Bowman’s layer, and stroma as measured by the perpendicular distance between the neighboring interfaces were generated using UHR-OCT. The flat keratometry and steep keratometry were obtained using Pentacam. Analysis of correlation was applied to explore the association between variables.ResultsMost of the biomechanical parameters and corneal sublayer thickness profiles showed statistical differences among three groups. A statistically significant linear relationship was noted between SP-A1 and DA ratio in all three groups. SP-A1 was found to be positively correlated with epithelial and Bowman’s layer thickness in the keratoconus (KC) group, and with stromal thickness in all three groups. In the normal and suspected keratoconus (SKC) groups, only stromal thickness was included in the stepwise linear regression to predict SP-A1, whereas in the KC group, steep keratometry and Bowman’s layer thickness were included.ConclusionsSignificant and different correlations were noted between corneal stiffness and corneal sublayer thickness in different groups, indicating that corneal sublayers may play different roles in maintaining corneal biomechanical stability between keratoconus and normal eyes.

Tinnitus in audiometrically normal listeners has been associated with reduced wave I amplitudes of the evoked auditory brainstem response but normal wave V amplitudes, a characteristic thought to be indicative of increased central gain compensation for reduced auditory nerve output. It remains uncertain, however, if central gain compensation is specific to tinnitus or can also occur for other conditions that reduce the auditory nerve output, such as aging. Here, we investigate if central gain increases with increasing age for people with normal hearing or very mild hearing losses. For 94 such people (aged 12-68 years, 64 women), we found that the amplitude of wave I decreased with increasing age but the amplitude of wave V was not correlated with the amplitude of wave I after accounting for age-related subclinical hearing loss and cochlear mechanical damage. Furthermore, the wave I/V amplitude ratio (the inverse of central gain) decreased with increasing age. Those findings are consistent with the presence of central gain compensation in aging. An analysis of the correlation between age and wave I/III or III/V amplitude ratios suggests that central gain compensation in aging likely occurs in the cochlear nuclei. For each of seven participants with tinnitus, the amplitude of wave I, wave V, and the wave I/V amplitude ratio were not significantly different from those of the non-tinnitus group. We conclude that increased central gain occurs with aging and is not specific to tinnitus.

Introduction: Plasmonic biosensors provide high sensitivity in detecting the low amount of biomarkers and pharmaceutical drugs. We studied the mesenchyme cell activity under the treatment of common sedative drugs of methadone and tramadol using the integrated plasmonic-ellipsometry technique.Methods: Mesenchymal stem cells were cultured on patterned plasmonic chips under the treatment of methadone and tramadol drugs. Three cultured chips were kept non-treated as the control ones. The plasmonic-ellipsometry technique was applied to study the signaling characteristic of the cells affected by these two drugs. In this technique, optical information regarding the amplitude ratio and phase change between p- and s-polarized light was recorded.Results: This drug treatment could affect the spectral plasmonic resonance and subsequently the phase shift (Δ) and the amplitude ratio (Ψ) values under p- and s-polarized impinging light. A more significant Δ value for tramadol treatment meant that the phase split was larger between p- and s-polarized light. Tramadol also had more prominent absolute Δeff and Ψeff values in comparison with methadone.Conclusion: We showed that tramadol caused more contrast in phase shift (Δ) and amplitude ratio (Ψ) between p- and s-polarized impinging light for cultured stem cells in comparison with methadone. It means that tramadol differentiated more the optical responses for p- and s-polarized lights compared to methadone. Our proposed technique possesses the potential of quantitative and qualitative analysis of drugs on humans even on a cell scale. DOI:10.34172/jlms.2021.46

Aquifer hydraulic parameter can change during earthquakes. Continuous monitoring of the response of water level to seismic waves or solid Earth tides provides an opportunity to document how earthquakes influence hydrological properties. Here we use data of two groundwater wells, Dian-22 (D22) and Lijiang (LJ) well, in southeast Tibet Plateau in response to the 2015 Mw 7.8 Gorkha earthquake to illustrate hydrological implications. The coherences of water level and seismic wave before and after the far-field earthquake show systematic variations, which may confirm the coseismic dynamic shaking influence at high frequencies (f > 8 cpd). The tidal response of water levels in these wells shows abrupt coseismic increases of both phase shift and amplitude ratio after the earthquake, which may be interpreted as an increase in the horizontal permeability of a confined aquifer in D22 well, and an occurrence in the vertical permeability of a switched semiconfined aquifer with larger epicentral distance and but high seismic ground motion. Using the continuous transmissivity monitoring, we show that the possible preseismic initial for ~ 1 day, coseismic response for ~ 3 days and postseismic healing for ~ 10 days during the earthquake. Thus, the dynamic shaking during the Gorkha earthquake may have caused confined aquifers to semiconfined aquifers by reopening of preexisting vertical fractures and later healing at epicentral distances about 1500 km.

Fatigue tests with solid round bar specimens were carried out to investigate the effect of stress amplitude ratio on the axial-torsion fatigue failure of low carbon steel under a certain equivalent stress. The processing of surface short cracks initiation and propagation were recorded by replica technology. It is observed that all the crack propagation curves based on the criterion of dominant effective short fatigue crack (DESFC) clearly exhibits a similar oscillations tendency caused by the microstructure. In addition, the fatigue life, fracture angle and crack source vary with the value of stress amplitude ratio. Hence, a short crack model incorporating the effects of stress amplitude ratio was used to simulate the short crack growth rate, and the model can directly estimate the biaxial short cracks growth rate under different stress amplitude ratios according to the experimental data of uniaxial short cracks. A good agreement is achieved between simulation results and experimental data.

The objective of this study was to assess the brainstem auditory evoked response (BAER) wave pattern in normal dogs as well as those with otitis externa (OE). The BAER test was performed on twenty five dogs with varying degrees of OE. Our study found that BAER of ears with severe OE had prolonged latencies of all waves and lower wave I to wave V amplitude ratio compared to the mildly affected or normal ears. However the inter – peak latencies were unaffected. Thus BAER can be a useful diagnostic tool to assess the hearing impairment due to conductive deafness in OE.

Purpose Approximately 1.3 billion people worldwide have vision impairment. The aim of the present study was to investigate the influence of Late-Onset blindness on cervical vestibular evoked myogenic potentials (cVEMP) responses. Accordingly, this study was performed to investigate and compare the parameters of the cVEMP test in sighted and late-onset blind individuals. Materials and method In this cross-sectional- comparative study, cVEMP was recorded by presenting a tone burst stimulus of 500 Hz with an intensity of 95 dBnHL in 20 sighted and 20 late-onset blind individuals aged between 18 and 30 years old. Results cVEMP was observed in all the individuals (100%). The average latency of P13 and N23, amplitude, amplitude ratio, and VEMP threshold did not differ significantly between the two groups (p > 0.05). Conclusion The findings of the study revealed that the formation of the neural pathway and reflex arch of cVEMP is similar between late-onset blind and sighted individuals. Thus, cVEMP can be a suitable test for assessing the vestibular function of late-onset blind people.

Author(s): Miki, Atsuya; Yasukura, Yuichi; Weinreb, Robert N; Maeda, Naoyuki; Yamada, Tomomi; Koh, Shizuka; Asai, Tomoko; Ikuno, Yasushi; Nishida, Kohji | Abstract: Purpose:To characterize the corneal biomechanical properties of glaucoma eyes by comparing the dynamic Scheimpflug biomechanical parameters between untreated glaucoma and control eyes. Methods:Cross-sectional observational data of dynamic Scheimpflug analyzer (Corvis ST) examinations were retrospectively collected from 35 eyes of 35 consecutive patients with untreated normal tension glaucoma and 35 eyes of 35 healthy patients matched on age and IOP. Ten biomechanical parameters were compared between the two groups using multivariable models adjusting for IOP, central corneal thickness, age, and axial length. The Benjamini-Hochberg method was used to correct for multiple comparison. Results:In multivariable models, glaucoma was associated with smaller applanation 1 time (P l 0.001, coefficient = -0.5865), applanation 2 time (P = 0.012, coefficient = -0.1702), radius (P = 0.006, coefficient = -0.5447), larger peak distance (P = 0.011, coefficient = 0.1023), deformation amplitude ratio at 1 mm (P l 0.001, coefficient = 0.072), and integrated radius (P l 0.001, coefficient = 1.094). These associations consistently indicate greater compliance of the cornea in glaucoma eyes. Conclusions:Untreated normal tension glaucoma eyes were more compliant than healthy eyes. The greater compliance (smaller stiffness) of normal tension glaucoma eyes may increase the risk of optic nerve damage. These results suggest the relevance of measuring biomechanical properties of glaucoma eyes.

Objective: To study differential post-stroke changes of excitability of spinal motor neurons innervating a group of antagonist muscles of ankle and their effects on foot inversion.Methods: F waves in tibialis anterior (TA) and peroneus muscles (PN) were recorded. The condition of spasticity and foot inversion in stroke patients were also evaluated. The differences of F wave parameters between patients and healthy controls (HC), as well as TA and PN, were investigated.Results: There were natural differences in the persistence of the F waves (Fp) and F/M amplitude ratio (F/M) between TA and PN in HC. Stroke patients showed significantly higher F/M in TA and PN, while there was no difference in Fp comparing to HC. The natural differences in F wave parameters between TA and PN were differentially retained after stroke. The natural difference of the two muscles in Fp remained unchanged and the F/M difference disappeared in those without spasticity or foot inversion, while the Fp difference disappeared and the F/M difference remained in those with spasticity or foot inversion.Conclusion: Based on the natural difference of the number and size of spinal motor neurons innervating TA and PN, their excitability may change differently according to the severity of the stroke, which may be the reason of foot inversion.