Wave Velocity Ratio Research Articles

Evaluation of Soil Moisture and Shear Deformation Based on Compression Wave Velocities in a Shallow Slope Surface Layer.

Rainfall-induced landslides occur commonly in mountainous areas around the world and cause severe human and infrastructural damage. An early warning system can help people safely escape from a dangerous area and is an economical and effective method to prevent and mitigate rainfall-induced landslides. This paper proposes a method to evaluate soil moisture and shear deformation by compression wave velocities in a shallow slope surface layer. A new type of exciter and new receivers have been developed using a combination of micro electro-mechanical systems (MEMS) accelerometers and the Akaike’s information criterion (AIC) algorithm, which can automatically calculate the elastic wave travel time with accuracy and reliability. Laboratory experiments using a multi-layer shear model were conducted to reproduce the slope failure. The relationships between wave velocities and soil moisture were found to be dependent on the saturation path (rain or drain); in other words, hysteresis was observed. The wave velocity ratio reduced by 0.1–0.2 when the volumetric water content (VWC) increased from 0.1 to 0.27 m3/m3. When loading the shear stress corresponding to slope angles of 24, 27, 29, or 31 degrees, a drop of 0.2–0.3 in wave velocity ratio was observed at the middle layer, and near 0.5 at the bottom layer. After setting the shear stress to correspond to a slope angle of 33 degrees, the displacement started increasing and finally, slope failure occurred. With increasing displacement, the wave velocities also decreased rapidly. The wave velocity ratio dropped by 0.2 after a displacement of 3 mm. Monitoring long-term elastic wave velocities in a slope surface layer allows one to observe the behavior of the slope, understand its stability, and then apply an early warning system to predict slope failure.

Studies on the relationships of the Curie surface with heat flow and crustal structures in Yunnan Province, China, and its adjacent areas

A Curie surface indicates the distribution of the thermal fields underground, providing a clear marker for the thermodynamic effect in the crust and mantle. In this paper, based on a geomagnetic field model (NGDC-720) and aeromagnetic data, we use power spectrum analysis of magnetic anomalies to estimate the Curie surface in Yunnan Province, China, and its adjacent areas. By combining the distribution of the Curie surface with regional heat flow, the geothermal gradient, crustal wave velocity ratio anomalies, high-conductivity layer anomalies, and the Moho surface, we reveal the connection between the undulation of the magnetic basement and the crustal structures. The results indicate that the uplift and depression of the Curie surface in the research area are distinct. The Curie surface is approximately inversely correlated to the surface heat flow. The Lijiang-Jianchuan-Baoshan-Tengchong and Jianchuan- Chuxiong- Kunming-Yuxi zones are two Curie surface uplift zones, and their crust-mantle heat flows are relatively high. The Curie surface uplift zone along the Lijiang-Xiaojinhe fault and Red River fault is consistent with the heading direction of the fault zone and is partially in agreement with the eastward mass flow of the Tibetan Plateau. The Curie surface uplift zone is consistent with the high wave velocity ratio and high-conductivity layer anomaly region of the crust. The depth of the Curie surface is less than the depth of the Moho surface.

Effect of Hammer Impact on Wave Propagation Characteristics of Soil

Wave transmission through soil due to dynamic load causes many problems to civil engineers craving safe construction. In this article, a laboratory model study is conducted to investigate the vibration propagation characteristics of soil due to the falling masses at different depths. Different types of impact, soils, and relative densities are used to study the characteristics of vibration transmission and energy dissipation. It was found that the increase in relative density and decrease in the depth causes an increase in the Peak Particle Acceleration and wave velocity of soil. An attempt is also made to determine the dynamic properties of soil using wave velocity ratios. A simple laboratory arrangement discussed here can be used to predict the wave propagation in soil reasonably and can determine its elastic constants. From the studies, it was revealed that the wave travel in soil and the peak particle acceleration depends on many factors like density, particle gradation, impact energy, etc.

Using the receiver function for studying earth deep structure in the Southern Borborema Province

The Borborema Province is characterized by a succession of tectonic events, including compressive periods associated with amalgamation of lithospheric blocks during the Brasiliano orogeny in the Neoproterozoic, superimposed by extension events related to the breaking of the continents and the South Atlantic formation in the Cretaceous. Ten seismographic broadband stations belonging to the Geoterm Network were installed in the Transversal Zone and South Domains to collect the data used in this work in the southern Borborema Province, northeastern Brazil. Thus, this study aims to determine the thickness of the Moho and Mid-Crustal (“Conrad”) discontinuities and estimate the Vp/Vs ratios to define rock composition using the receiver function over a time window, using the HK-stacking method. The station in the Alto Moxotó Terrain determined a crustal thickness of 35.4 km. The two stations in the Pernambuco-Alagoas Terrain estimated thickness of approximately 37 km and no thinning trend in the geotectonic context. The four stations in the Sergipano Folding Belt indicated thickness ranging between 34.6 and 37.2 km, and a South-North crustal thickening. Mid-crustal discontinuity depth estimates ranged between 10 and 19 km, indicating a WNW-ESE thinning of the upper crust in the middle of the area. The P and S wave velocity ratios appeared to have no geological or tectonic correlation and ranged between 1.68 and 1.77, indicating that the crustal composition is predominantly felsic.

452-P: Albumin/Creatinine Ratio and Pulse Wave Velocity Predicts Coronary Artery Disease and Renal Outcome in Type 2 Diabetic and Prediabetic Subjects

Introduction: Silent coronary heart disease is frequently undetected in type 2 diabetes mellitus (DM2) and prediabetes determined by glucose intolerance (GI). Pulse wave velocity (PWV) and albumin-creatinine ratio (ACR) have been considered markers of cardiovascular mortality, coronary heart disease and chronic renal failure. Aims: To evaluate the incidence of coronary heart disease (CHD) and its relationship with urinary albumin-creatinine ratio, glomerular filtration rate (GFR) and PWV in type 2 DM with silent CHD. Methods: We analyzed 92 individuals (44 male), 49 (60±7y) type 2 DM non-insulin dependents and 43 prediabetics (43±4y), with Grade I-II hypertension and no symptoms of CHD. All type 2 DM patients were under hypoglycemic treatment with an A1C hemoglobin between 5.5 and 6.5%. Every patient underwent a myocardial perfusion SPECT scan. In those subjects with ischemic patterns, a coronary angiography was performed. In addition, a PWV, glomerular filtration rate (CrCl), and ACR were evaluated. Statistics: mean±SEM, and ANOVA followed by Post Hoc analysis among groups. Results: Silent CHD was found in 48.59% of DM2 and 25.58% of GI. DM2 and GI patients with CHD had higher ACR and PWV and reduced glomerular filtration rate (p<0.05). DM2 and GI showed a negative relationship between GFR and ACR (p<0.05). Type 2 diabetic and GI showed a negative relation between GFR and ACR or PWV when having GFR above 60 mil.min. Meanwhile, in type 2 Diabetics with CHD and GFR < 60 ml.min a negative relationship with PWV was only, suggesting a cardiorenal interaction in type 2 diabetes. Conclusions: Higher PWV, lower GFR and ACR predict the incidence of CHD in DM2. GI also represent a group of higher risk for coronary heart disease with the same predictors showed in DM2. PWV seems to represent a reliable marker. Disclosure R.A. Sanchez: None. M.J. Sanchez: None. A.J. Ramirez: None.

Characteristics of the level of somatic health and biological age of persons with neuro-stressful professional activity

Introduction.Unfavorable tendencies in the health of the working population, especially those with high neuro-emotional stress in professional activities, the scarcity of information about the impact of professional factors on the health and performance of police officers, which is characterized by nervous and hard work, determine the relevance of this study.The aim of the studyis to study the biological age with an assessment of the rate of aging of individual body systems and the level of somatic health of police officers.Materials and methods.We examined 110 men — police officers. Biological age was determined by an automated expert system of diagnostics of aging by the method of A.A. Podkolzin, V.N. Crutko. To quantify the level of somatic health the method of G.L. Apanasenko was used. We used clinical, physiological and computational methods to study the state of the cardiovascular and respiratory systems, static balancing, interviewing methods and mathematical statistics.Results.The accelerated rate of aging was revealed in 65.4% of the examined patients. Accelerated aging of the neuropsychic, respiratory and cardiovascular systems was the most common (97.3%, 94.6% and 75.5%, respectively). A decrease in functional activity of blood circulation was revealed in 70.9%. The coefficients of endurance of cardiac activity and efficiency of blood circulation exceeded the norm, which indicates a possible weakening of the activity and the state of fatigue of the cardiovascular system, myocardial weakness. The ratio of pulse wave velocity in the vessels of muscular and elastic types below the norm was determined in 40.9% of the surveyed, which may indicate the presence of transitional and late-stage hypertension, 62.2% of such persons have an accelerated type of aging of the cardiovascular system. The proportion of persons with accelerated type of aging of the respiratory system significantly (p<0.05) exceeded the proportion of persons with normal and delayed type of aging. The proportion of persons with an accelerated rate of aging was significantly higher in persons with a duration of static balancing below the standard (79.1% [71.5–86.7] versus 20.9% [13.3–28.5], p=0.009).Conclusions.Accelerated rates of aging of cardiovascular, respiratory and neuropsychic systems, low functionality of the body can be regarded as a manifestation of occupational stress. The discrepancy between the subjective assessment of their health and objective indicators of the rate of aging, the level of somatic health can be caused by the socio-psychological characteristics of the service and the tightening of medical requirements for police officers.

The application of cracking coefficient method to the study on fractures in volcanic of Anda area

According to the actual situation of volcanic reservoirs in Anda area, this paper uses the comprehensive analysis of drilling and logging data to predict the fracture development of volcanic reservoirs in the study area. Among them, the ratio of longitudinal wave velocity, “crack coefficient” method, is used to analyze and calculate the crack development frequency. The research shows that the fractures of volcanic reservoirs in Anda area are relatively developed, and the characteristics of fracture parameters will inevitably affect the exploration and production of natural gas in this area.

Should we calculate arterial stiffness gradient in middle-aged women with increased cardiovascular risk?

Purpose: The study was designed to evaluate clinical and laboratory determinants pulse wave velocity (PWV) ratio in women at the age of 50–65 years without overt cardiovascular disease but having elevated cardiovascular risk, such as hypertension, obesity, diabetes and hypercholesterolemia.Materials and methods: We analyzed data from 1170 women enrolled in the national-wide primary prevention program. Univariate and multivariate linear regression analysis was used to establish independent risk factors in groups based on clinical data, laboratory values, and comorbidities. Arterial stiffness was evaluated using applanation tonometry technique (SphygmoCor). The PWV ratio was calculated by dividing cfPWV to crPWV.Results: In multivariate logistic regression analysis, age (OR = 1.109, p < .001), waist circumference (OR = 1.021, p = .001) and mean arterial pressure (OR = 1.031, p < .001) were found as independent clinical determinants of PWV ratio, while independent laboratory determinants were urine albumin to creatinine ratio (OR = 1.189, p = .010), triglycerides (OR = 1.161, p = .034), glucose (OR = 1.28, p = .001) and eGFR (OR = 0.998, p = .007). Diabetes (OR = 1.811, p = .029), hypertension (OR = 2.784, p = .042) and menopause (OR = 1.054, p = .018) were established as independent factors in comorbidities group. The analysis confirmed that PWV ratio (R2 = 0.0667, p < .001), as well as carotid radial (R2 = 0.0341, p < .001) and carotid femoral PWV (R2 = 0.1752, p < .001) is affected by mean arterial blood pressure.Conclusions: Age, abdominal obesity, blood pressure, triglycerides, glucose, kidney function parameters and menopause all are associated with PWV ratio. More importance to women with high cardiovascular risk should be given whilst screening and stratifying further progression of the disease.

Loss of the Normal Gradient in Arterial Compliance and Outcomes of Chronic Kidney Disease Patients

Background: In dialysis patients, loss of the normal gradient in arterial compliance, assessed by the pulse wave velocity (PWV) ratio, predicts all-cause mortality better than does carotid-femoral PWV (CF-PWV) alone. However, the prognostic significance of the PWV ratio for outcome in chronic kidney disease (CKD) patients remains unclear. Methods: In this longitudinal cohort study, CKD patients who visited our CKD management clinic between April 27, 2006, and March 27, 2008, were included and followed up. To assess the gradient in arterial compliance, the PWV ratio was calculated using CF-PWV divided by carotid-radial PWV. Results: A total of 209 patients in CKD stages 1–4 with a median follow-up of 3.74 years were included. Patients with higher PWV ratio were relatively older (p < 0.001) and had worse renal function (p < 0.001), more hypertension (p < 0.001), diabetes mellitus (p < 0.001), and cardiovascular or cerebrovascular disease (p < 0.001). The median time to patient outcome (death, renal replacement therapy, or double increase in serum creatinine from baseline) in the group with a PWV ratio above the median (89.8 months, 95% CI 84.2–95.5) was shorter than that in the group with a PWV ratio below the median (105.3 months, 95% CI 101.3–109.3, p = 0.001). Univariate Cox regression analysis showed that both PWV ratio and CF-PWV were significantly associated with patient outcome. In multivariate Cox regression analysis, both PWV ratio and CF-PWV were associated with patient outcome. However, the HR for CF-PWV (2.177, 95% CI 1.064–4.453, p = 0.033) was slightly higher than that for PWV ratio (2.091, 95% CI 1.049–4.167, p = 0.036). There was a significant interaction effect between PWV ratio and CKD stage. It was shown that patients with advanced CKD stages and higher PWV ratios had a significantly higher risk of adverse CKD outcome (p = 0.006). Conclusions: The PWV ratio, as a measure of loss of the normal gradient in arterial compliance, was associated with CKD patient outcome. Patients with advanced CKD and a higher PWV ratio had a significantly higher risk of adverse CKD outcome.

Pulse wave velocity to global longitudinal strain ratio in hypertension.

Arterial elastance to left ventricular elastance ratio assessed by echocardiography is widely used as a marker of ventricular-arterial coupling. We investigated whether the ratio of carotid-femoral pulse wave velocity, as a marker of arterial stiffness, to global longitudinal strain, as a marker of left ventricular performance, could be better associated with vascular and cardiac damage than the established arterial elastance/left ventricular elastance index. In 299 newly-diagnosed untreated hypertensives we measured, carotid-femoral pulse wave velocity, and carotid intima-media thickness, coronary-flow reserve, arterial elastance/left ventricular elastance, global longitudinal strain, and markers of left ventricular diastolic function (E/A and E') by echocardiography. Pulse wave velocity-to-global longitudinal strain ratio (PWV/GLS) was lower in hypertensives than controls (-0.61±0.21 vs -0.45±0.11m/sec%, P<0.001). Low PWV/GLS values were associated with carotid-intima media thickness>0.9mm (P=0.003), E/A≤0.8 (P=0.019) and E'≤9cm/sec (P=0.002) and coronary-flow reserve<2.5 (P=0.017), after adjustment for age, sex and mean arterial pressure. Low PWV/GLS was also associated with increased left ventricular mass and left atrial volume in the univariate (P=0.003 and 0.038) but not in the multivariate model. In hypertensives, there was no significant association of arterial elastance-to-left ventricular elastance index with carotid intima media thickness, coronary flow reserve, E/A, E', or left atrial volume with the exception of an inverse association with left ventricular mass (P=0.027). Pulse wave velocity-to-global longitudinal strain ratio but not the echocardiography-derived arterial elastance-to left ventricular elastance index is related to impaired carotid-intima media thickness, coronary-flow reserve and diastolic function in hypertensives.

Valley amplification of horizontal ground strain

It is recognized that seismic damages to segmented buried pipelines depend in part upon transient ground strain due to seismic wave propagation. Such wave propagation damage seems to be larger at sites with variable subsurface conditions, because of drastic changes in seismic wave characteristics as they propagates in heterogeneous rock and soil layers. This paper intends to investigate the amplification of horizontal ground strains in a valley subjected to vertically incident SH waves. A 2D model with an inclined soil-rock interface is established to simulate conditions of the valley subject to seismic wave propagation. A procedure for evaluating the ground strain amplification is developed by consideration of travel path effects. Three amplification/de-amplification mechanisms are specifically considered, the ground velocity amplification, ground strain amplification due to the change in the propagation direction, and de-amplification due to a lack of total reflection at the soil-rock interface. The analysis results show that the maximum amplification factor is mainly affected by the interface inclination angle and shear wave velocity ratio between the valley soil and the base rock. For a given number of wave cycles, the amplification factor grows with the increment of the inclination angle and declines with the growth of shear wave velocity ratio. The de-amplification at inclined interface is likely to nullify the amplification generated by travel path effects.

Anomalous Vp/Vs Ratios at Seismic Frequencies Might Evidence Highly Damaged Rocks in Subduction Zones

AbstractUnusually high compressional (P) to shear (S) wave velocity ratios (Vp/Vs) were measured at different subduction zones and interpreted as fluid‐pressurized regions. Because no laboratory data reported such high values in isotropic rocks, mineralogical or anisotropic constrains were assumed. However, fluid‐saturated rocks' Vp/Vs is a frequency‐dependent property so that standard laboratory measurements cannot be directly upscaled to the field. Using a new methodology, we measured the property in the elastic regime relevant to field measurements for diverse lithologies. We obtained extreme Vp/Vs values, consistent with those reported at seismic frequency in the field. Consistently with a model, it shows that if high fluid pressure is a key factor, anomalous Vp/Vs values could evidence intense degrees of microfracturation in isotropic rocks, whichever its mineralogical content. The permeability of these regions could be larger than 10−16 m2.

Restrictive Spirometry Pattern, Cardiac Structure and Function, and Incident Heart Failure in African Americans. The Jackson Heart Study.

Although chronic obstructive pulmonary disease has been related to heart failure, the relationship between the restrictive spirometry pattern (forced vital capacity [FVC] < 80% predicted with preserved forced expiratory volume in 1 second [FEV1]/FVC ratio) and heart failure is poorly understood. To determine whether having a restrictive spirometry pattern is associated with incident heart failure hospitalization. Community-dwelling African Americans from the Jackson Heart Study (total n = 5,306; analyzed n = 4,210 with spirometry and heart failure outcome data) were grouped by restrictive spirometry (FEV1/FVC ≥ 0.70, FVC < 80%; n = 840), airflow obstruction (FEV1/FVC < 0.70; n = 341), and normal spirometry (FEV1/FVC ≥ 0.70, FVC ≥ 80%; n = 3,029) at the time of baseline examination in 2000-2004. We assessed relationships of echocardiographic parameters and biomarkers with spirometry patterns using regression models. Incident heart failure was defined as an adjudicated hospitalization for heart failure after January 1, 2005 in subjects with no self-reported heart failure history. We used multivariable-adjusted Poisson regression models and Cox proportional hazards models, with death treated as a competing risk in the Cox models, to test associations between spirometry patterns and incident heart failure. We also modeled the association of FVC% predicted with heart failure hospitalization risk using a restricted cubic spline after excluding subjects with airflow obstruction. At the time of baseline spirometry, participants with restrictive spirometry had a median age of 57.2 years (interquartile range, 47.8-64.1); 38.1% were male. Compared with normal spirometry, restrictive spirometry was associated with a higher transmitral early (E) wave velocity to atrial (A) wave velocity ratio, higher pulmonary artery systolic pressure, and higher endothelin levels. After a median follow-up time of 8.0 years, 8.0% of subjects with restrictive spirometry (n = 67) had developed incident heart failure, compared with 3.8% of those with normal spirometry (n = 115) and 10.6% of those with airflow obstruction (n = 36). After risk adjustment, both a restrictive pattern (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.1-2.0) and airflow obstruction (HR, 1.7; 95% CI, 1.1-2.5) were associated with increased rates of incident heart failure hospitalization compared with normal spirometry. Using flexible modeling, the lowest hazards of heart failure hospitalization were observed around FVC 90-100%, with lower FVC% values associated with an increased incidence of heart failure. Both a restrictive pattern on spirometry and airflow obstruction identify African Americans with impaired lung health at risk for heart failure.

A0504 The Prevalence of Central Hypertension and Its Association with Target Organ Damage in Community-Dwelling Elderly Chinese

Objectives: We aimed to investigate the prevalence of central hypertension and its association with target organ damage (TOD). Methods: 1983 community-dwelling elderly Chinese were recruited for this analysis. Brachial and central blood pressure (BP) were measured by a oscillometric device and SphygmoCor, respectively. Brachial hypertension was defined by brachial systolic (SBP)/diastolic BP (DBP) ≥140/90 mmHg or using antihypertensive medications. Central hypertension was defined by central SBP/DBP ≥130/90 mmHg or using antihypertensive medications. TOD including left ventricular hypertrophy (LVH) and diastolic dysfunction (LVDD), carotid-femoral pulse wave velocity (CF-PWV) and urinary albumin-creatinine ratio (UACR), were evaluated by standardized methods. Results: In this cohort, there were 563(28.4%) brachial and central consistent normotension (BCCN), 46 (2.3%) isolated brachial hypertension (IBH), 27 (1.4%) isolated central hypertension (ICH), and 1347 (67.9%) brachial and central combined hypertension (BCCH). In ANOVA, BCCH showed significantly higher levels in all TOD than BCCN. In multiple logistic regression, all TOD were significantly associated with BCCH (LVH: adjusted OR[95%CI] = 2.03[1.55, 2.68]; LVDD:2.29[1.53, 3.43]; CF-PWV > 10m/s: 3.41[2.55, 4.58]; UACR > 30 mg/g: 1.97[1.58, 2.44]), rather than IBH or ICH. Conclusion: Central hypertension was prevalent (69.3%) in this elderly cohort. BCCH was independently and significantly associated with cardiac, arterial and renal damage. This finding implies that both brachial and central BPs need to be considered for managing hypertension.

Apparent motion as hyperacuity phenomenon under low two-point spatial resolution

In this study, we analyze the acceleration time histories data at the Belleplaine (Guadeloupe, French West Indies) vertical array, recorded between 2008 and 2014, to evaluate the seismic response of sediments. First, we apply seismic interferometry by deconvolution method to compute the in-situ shear wave velocity between the sensor at the surface and the two shallow sensors located at GL-15m and GL-39m depth. The efficiency of this method is discussed by studying the variability of the velocity profile obtained and comparing with the in-situ geophysical survey of the site. Computed strains between sensors remain very weak, lower than 10−5, meaning that nonlinearities are not expected for these events. Moreover, the small dispersion of shear wave velocities values deduced from seismic interferometry may be related to the elastic behavior of the soil column. Furthermore, the transfer functions between each sensor combination are inverted to obtain a new velocity profile compatible with the geological knowledge of the site. The lag times calculated by seismic interferometry are then used to constrain random perturbations of the inverted velocity profile, allowing to study the variability of the 1D soil response. Since recorded motion has a PGA less than 10 cm/s2 in the dataset, we numerically predict the nonlinear response of the site using strong motion from a worldwide dataset. Furthermore, we study the ratio between the PGV and the medium shear velocity as a proxy showing the development of shear deformation during strong motion. Finally, using strong motion events from a worldwide dataset, we numerically predict the nonlinear response of the site based on shear wave velocity variation and the strain proxy computed by the particle velocity versus shear wave velocity ratio. We conclude that seismic interferometry by deconvolution is a robust and accurate solution to help extracting the shear wave velocity profile and to monitor the soil nonlinear response. This technique can be used when strong earthquakes will be recorded at this experimental site in order to track and assess nonlinear effects in the soil column.

Watching Dehydration: Seismic Indication for Transient Fluid Pathways in the Oceanic Mantle of the Subducting Nazca Slab

AbstractIntermediate depth seismicity in subduction zones often occurs in the form of two slab‐parallel bands. We estimated the seismic P to S wave velocity ratio within the shallowest part of the lower seismicity zone (LSZ) in the mantle of the subducting slab of the Central Andean subduction system at 50‐km depth, 30 km below the Moho, using local earthquake data. We find an exceptionally high VP/VS value larger than ∼2.0 that cannot be explained by a realistic solid lithology but requires the presence of fluid‐filled porosity. This implies that the incoming Nazca plate must be partially hydrated to this depth below the seafloor. We introduce a state‐of‐the‐art petrophysical model that takes into account the thermodynamic and poroelastic effects of dynamic metamorphic mineral dehydration at 1.8 GPa and consider anisotropic effects. The model shows that a high VP/VS value generally indicates that the medium is near the percolation threshold, that is, that porosity must be interconnected. This result is consistent with observations from outcrops of paleosubduction zones, laboratory experiments, and numerical simulations. It follows that the shallowest part of the LSZ of the Central Andes must reside at a temperature at which mineral dehydration reactions take place, here between 430 and 500 ° C. For the first time, we can confirm that the observations of transient dehydrating fluid‐filled vein structures with a pore volume in the order of only 10−3 are reasonable for the LSZ and enough to allow for effective drainage.

4917Global longitudinal strain to pulse wave velocity ratio (VA coupling) is a better indicator of target organ damage than the arterial elastance to LV elastance ratio in hypertensives

4917Global longitudinal strain to pulse wave velocity ratio (VA coupling) is a better indicator of target organ damage than the arterial elastance to LV elastance ratio in hypertensives

Using Ultrasonic Pulse and Artificial Intelligence to Investigate the Thermal-Induced Damage Characteristics of Concrete

Using the traditional assessment method considering single-input and single-output variables, the correlation between ignition loss and maximum temperature is usually used to evaluate the fire-damage degree of concrete. To improve this method, multi-input and multi-output variables are examined in this study using a newly-developed experiment consisting of a thermo-induced damage test, ultrasonic pulse (UP) measurement technique, and uniaxial compressive test. The input variables include the designed strength, rate of heating, maximum temperature, and exposure time. The output variables include the stiffness, strength, toughness, and ratio of shear wave velocity to pressure wave velocity (Vs/Vp). Artificial intelligence (AI) is used to assess these variables. The test results show that the stiffness, strength, and toughness decreased with an increase in maximum temperature. The measured Vs/Vp has a high positive correlation with maximum temperature and the reduced ratio of stiffness, strength, and toughness. This correlation was also identified using AI analysis. The findings in this study suggest that the wave velocity ratio obtained using the UP technique can be applied to quantitatively evaluate thermal-induced damage in concrete.

Application of ARFI-SWV in Stiffness Measurement of the Abdominal Wall Musculature: A Pilot Feasibility Study

The purpose of this study was to assess the feasibility of acoustic radiation force impulse shear wave velocity and textural features for characterizing abdominal wall musculature and to identify subject-related and technique-related factors that can potentially affect measurements. Median shear wave velocity measurements for the right external abdominal oblique were the same (1.89 ± 0.16 m/s) for both the active group (healthy volunteers with active lifestyles) and the control group (age and body mass index–matched volunteers from an ongoing hernia study). When corrected for thickness, the ratio of right external abdominal oblique shear wave velocity -to-muscle thickness was significantly higher in the control group than in the active volunteers (4.33 s−1 versus 2.88 s−1; p value 0.006). From the textural features studied for right external abdominal oblique, 8 features were found to be statistically different between the active and control groups. In conclusion, shear wave velocity is a feasible and reliable technique to evaluate the stiffness of the abdominal wall musculature. Sonographic texture features add additional characterization of abdominal wall musculature.

FGF23-klotho axis, bone fractures, and arterial stiffness in dialysis: a case-control study.

New bone markers such as sclerostin, Dickkopf-related protein 1 (DKK1), fibroblast growth factor-23 (FGF23), and α-klotho have been identified as potential key players in bone and vascular abnormalities of chronic kidney disease. Therefore, we aimed to assess whether these markers are associated with fractures, bone metabolism, and vascular stiffness in dialysis patients. In a prospective hemodialysis cohort, where plasma samples and vascular assessment were performed at baseline, we matched patients who experienced a fracture during follow-up with sex- and age-matched non-fractured patients on a 1:4 ratio. Sclerostin, DKK1, α-klotho, FGF23, and markers of bone formation (alkaline phosphatase and procollagen type 1-N terminal propeptide [P1NP]) and bone resorption (tartrate-resistant acid phosphatase 5b [TRAP5b]) were measured in baseline plasma samples. Aortic-brachial pulse wave velocity ratio, a blood pressure independent measure of arterial stiffness, was used to assess vascular stiffness at baseline. We included 130 hemodialysis patients (26 fractured, 104 non-fractured) with a median follow-up of 42months and a median age of 72years. In multivariate Cox regression models, high FGF23 levels were associated with increased fracture incidence (adjusted HR = 2.97; 95% CI 1.18, 7.43). α-Klotho levels were associated with bone formation but not resorption markers. In both univariate and multivariable adjusted models, α-klotho levels were inversely associated with the aortic-brachial pulse wave velocity ratio (β = - 0.070; 95% CI - 0.133, - 0.006). These results suggest a role for FGF23/klotho axis on bone and vascular metabolism in dialysis populations.