Wave Velocity Research Articles

Novel CMR-assessed right ventricular-pulmonary artery coupling index independently associates with exercise capacity and clinical risk in pulmonary arterial hypertension

Abstract Background We defined a novel noninvasive right ventricle (RV)–pulmonary artery (PA) coupling index as the ratio of cardiovascular magnetic resonance (CMR)-assessed RV direct flow (RVDF) and PA pulse wave velocity (PWV), and investigated its associations with exercise capacity and clinical risk in pulmonary arterial hypertension (PAH). Method 43 PAH patients (mean age 46±12 years, M:F 7:36) and 60 healthy volunteers (mean age 46±13 years, M:F 11:48) underwent CMR and cardiopulmonary exercise test (CPET) within one week. From cine CMR, RV ejection fraction (EF) and RV end-diastolic volume (RVEDV) were calculated using volumetric analysis; and tricuspid annular plane systolic excursion (TAPSE), feature tracking. PAPWV was the ratio of early systolic DPA flow and DPA area measured from instantaneous phase and magnitude through plane 2D flow CMR images across the pulmonary trunk, respectively. RVDF was the 4D flow CMR-assessed blood volume entering and exiting the RV in one cardiac cycle, indexed to RVEDV. RV-PA coupling was RVDF/PAPWV. Based on CPET-assessed peak oxygen consumption (PVO2), all 103 participants were stratified into two groups: PVO2>15 ml/kg/min; and PVO2≤15 ml/kg/min. Based on the REVEAL (Registry to Evaluate Early and Long-term PAH Disease Management) 2.0 score, the 43 PAH patients were stratified into low risk (score ≤6) and intermediate to high risk (score >6) groups. Results RVDF/PAPWV was significantly lower in PAH vs. controls (7.9 vs. 20.4 %/(m/s), P<0.001); and in PAH patients with intermediate to high risk vs. low risk (4.6 vs. 9.4 %/(m/s), P=0.001). On multivariable analyses, RVDF/PAPWV was an independent predictor of PVO2≤15 ml/kg/min (=0.302, P=0.001) among all participants, and of REVEAL 2.0 score >6 (=0.621, P=0.009) among PAH patients. Compared to RVEF and TAPSE, RVDF/PAPWV had numerically higher discrimination (p values non-significant based on Delong test) for PVO2≤15 ml/kg/min (AUC=0.914 vs. 0.872, 0.843); and among PAH patients, REVEAL 2.0 score >6 (AUC=0.851 vs. 0.723 and 0.728) (Figure). Conclusion CMR-derived noninvasive RVDF/PAPWV independently associates with exercise capacity and PAH clinical risk, supporting its utility as an imaging marker of disease progression and therapeutic response.

Validation and development of a scoring system for comprehensively evaluating arterial damage in the elderly chinese

Abstract Background and aims Existing assessments on arterial damage focus on specific segments of arterial system (e.g., carotid artery), lacking a comprehensive index to evaluate overall arterial health. We aimed to integrate existing assessments for arterial damage and develop a new score, named Arterial Damage Index (ADI), to comprehensively evaluate arterial health status of the whole-body arterial system. Methods A total of 3075 community-dwelling elderly Chinese (age ≥65 years) from the North Shanghai Study (2014–2022) were included. Assessments on arteries including ankle-brachial index (ABI), pulse wave velocity (PWV), carotid intima-media thickness (CIMT) and plaques, pulse pressure (PP), and inter-arm (IASBPD) and -leg (ILSBPD) systolic blood pressure difference were included for screening. Cox proportional hazards regressions of MACEs (non-fatal myocardial infarction, non-fatal stroke, and all-cause mortality) were conducted to acquire the ADI algorithm. Internal and external validation on ADI were also performed. Results Over a median follow-up period of 6.4 years, 316 individuals (10.3%) experienced an incident of MACE. After screening, PWV, ABI, PP, CIMT, and carotid plaque were included for ADI scoring system. Survival analysis revealed a significant difference in the rates of composite events across different ADI stratifications (p for trend < .05). ADI showed superior discriminative performance (C-index 0.65±0.02) compared to any individual arterial-related indicator. Calibration curve shows the predictive model showed that the predicted and actual probabilities were broadly consistent. Additionally, ADI provided better incremental value when added to the base model (net reclassification improvement, 36.2% [95% CI, 15.3%-52.1%]; p < .05, integrated discrimination improvement, 7.9% [95% CI, 4.9%-11.0%]; p < .05) compared to any individual arterial-related indicator. These findings were confirmed in internal validation sets (p for DeLong tests >0.05), and was externally validated in 2155 participants from a community-based cardiovascular disease cohort among residents in Beijing, China. Conclusion ADI can comprehensively assess arterial damage and provide a valuable tool for further assessment of future cardiovascular risk.central illustration

Optimal blood pressure values to reduce arterial stiffness, an analysis from UK Biobank

Abstract Introduction Increased arterial stiffness is a powerful independent risk factor for adverse cardiovascular events. While pulse wave velocity has been used extensively as a biomarker of vascular health reflecting functional and structural arterial changes, its use in clinical practice was limited. The Arterial Stiffness Index (ASI) simplifies the assessment of arterial stiffness using a pulse waveform obtained at the finger with an infrared sensor with BP measured using an automated device. Age and raised blood pressure (BP) are major contributors to increased arterial stiffness, but time trajectories of ASI in the general population and optimal BP values to reduce arterial stiffening are scarcely known. Purpose To establish temporal changes of ASI and identify BP values associated with longer-term improvement of arterial stiffness. Methods The study analysed data from UK Biobank (baseline n=154,684, median age 54, interquartile range (IQR) [40-72] years; 52% female; 91% white, 28% hypertension). ASI was measured using PulseTrace PCA2 device (CareFusion, USA) at baseline with measurements repeated in 4617 individuals after a median follow up of 3.0, IQR [2.8-3.3] years. BP was measured during the same time points. Multivariable (adjusted for age, sex, diabetes, and use of BP-lowering drugs) linear regression was used to determine the association of BP with baseline and the association of BP and ASI changes during follow up. ROC analysis was used to determine BP values associated with improvement (reduction) of ASI during follow up. Continuous data are presented as median [IQR] and compared using Wilcoxon test. R software packages were used for analyses. Results At baseline, ASI (m/sec) was higher in those with systolic BP (SBP) >140 mmHg (9.60 [7.15-11.85] vs. 8.67 [6.77-10.70] for SBP ≤140 mmHg, p<0.001) and in those with diastolic BP (DBP) >90 mmHg (9.90 [7.48-12.16] vs 8.81 [6.78-10.90] for DBP ≤90 mmHg, p<0.001). Both SBP and DBP were independently associated with ASI at baseline (B±SE 0.08±0.02 and 0.79±0,29m, respectively; p<0.001 for both). During follow up, the population level SBP remained unchanged (change 0 [-8 - 8] mmHg), with some reduction in DBP (-1.0 [-6.0 - 3.5]) mmHg. SBP reduced in 2234 (48%) and DBP in 2517 (55%). ASI increased by 0.56 [-1.46 - 2.78] m/s, with ASI reduction observed in 1935 (42%). An increase in DBP but not in SBP was independently associated with an increase in ASI (B±SE DBP 0.04±0.01, p<0.001; SBP 0.007±0.006, p=0.22; DBP 0.04±0.007, p<0.001). The baseline BP was predictive of the magnitude of changes in ASI: SBP 132 mmHg (AUC 0.53, p=0.001) and DBP 83 mmHg (AUC 0.54, p<0.001). Conclusions Increased arterial stiffness is associated with higher BP, particularly with higher DBP. Raised ASI is reversible, providing BP is adequately controlled with optimal BP being <132/83 mmHg.

New intensity prediction equation in Western China considering site equivalent shear wave velocity

New intensity prediction equation in Western China considering site equivalent shear wave velocity

Plasma Lipidomic Profiles Improve upon Traditional Risk Factors for the Prediction of Arterial Stiffness Among Patients with Type 2 Diabetes Mellitum: A Randomized, Placebo-Controlled Trial

Background: Exercise or vitamin D intervention can reduce the risk of arterial stiffness; however, the underlying mechanisms of lipid metabolism remain unexplored. To examine the effects of a 12-week moderate and vigorous exercise program (65–80% maximal heart rate, 60 min/time, 2~3 times/week) with or without vitamin D supplementation (1000 IU/day) on the reduction in arterial stiffness and further explore whether the effects of interventions could be associated with the basal lipidome among patients with Type 2 diabetes mellitum (T2DM). Method: 61 patients with T2DM were randomly assigned to the following groups: control (CON, n = 15), exercise (EX, n = 14), vitamin D (VD, n = 16), and exercise + vitamin D (EX + VD, n = 16). Arterial stiffness risk factors (ankle–brachial index (ABI); brachial–ankle pulse wave velocity (baPWV), systolic blood pressure (SBP), and diastolic blood pressure (DBP)) were evaluated before and after the intervention. The plasma lipidome was determined using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Machine learning was applied to establish prediction models for the responsiveness to arterial stiffness. Result: Vitamin D supplementation could inhibit the decrease in the ankle–brachial index (mean ± SD: EX + VD and VD, −0.001 ± 0.058; EX + CON, −0.047 ± −0.089; p = 0.03). We observed high inter-individual variability in the arterial stiffness risk factors in response to the interventions. We also found that optimally selecting the lipid predictors at baseline, such as SM d44:6, LPE 18:2, and Hex2Cer 29:0, could enhance the predictive power by 100% for arm SBP changes in the exercise group. Basal levels of Cer (33:1) and GM3 (44:4) could enhance the predictive power by 100% for changes in baPWV in the vitamin D group. Conclusions: A 12-week vitamin D supplementation was beneficial in preventing arterial stiffness. Compared with traditional clinical risk factors, specific lipids at baseline could significantly improve the ability to predict intervention-induced changes in the reduction of arterial stiffness.

Vascular Chemerin from PVAT contributes to Norepinephrine and Serotonin-Induced Vasoconstriction and Vascular Stiffness in a Sex-Dependent Manner.

The adipokine chemerin supports normal blood pressure and contributes to adiposity-associated hypertension, evidenced by falls in mean arterial pressure in Dahl SS rats given an antisense oligonucleotide against chemerin. In humans, circulating chemerin is positively associated with hypertension and aortic stiffness. Mechanisms of chemerin's influence on vascular health and disease remain unknown. We identified chemerin production in the vasculature-the blood vessel and its perivascular adipose tissue (PVAT). Here, using RNAScope®, QPCR, isometric contractility, high frequency ultrasound imaging, and western blot in the Dahl SS rat, we test the hypothesis that endogenous chemerin amplifies agonist-induced vasoconstriction through Chemerin1 and that chemerin drives aortic stiffness in the thoracic aorta. CMKLR1 (Chemerin1) expression was higher in the media, and Rarres2 (chemerin) expression was higher in the PVAT. Chemerin1 antagonism via selective inhibitor CCX832 reduced maximal contraction to norepinephrine (NE) and serotonin (5-HT), but not angiotensin II, in isolated thoracic aorta (PVAT intact) from male Dahl SS rat. In females, CCX832 did not alter contraction to NE or 5-HT. Male, but not female, genetic chemerin knockout Dahl SS rats had lower aortic arch pulse wave velocity than wild types, indicating chemerin's role in aortic stiffness. Aortic PVAT from females expressed less chemerin protein than males, suggesting PVAT as the primary source of active chemerin. We show that chemerin made by the PVAT amplifies NE and 5-HT-induced contraction and potentially induces aortic stiffening in a sex-dependent manner, highlighting the potential for chemerin to be a key factor in blood pressure control and aortic stiffening.

A triangular acoustic emission source location method considering its anisotropic propagation behavior on the surface of finger-joint-laminated board

ABSTRACT To understand the anisotropic propagation characteristics of acoustic emission (AE) signals in finger-joint-laminated boards, an improved planar localization method for AE sources is proposed. Initially, the AE source was generated by the pencil-lead break (PLB) at a fixed position on the surface of the glued wood specimen, and two AE sensors were arranged in different directions at a fixed distance of 60 mm, and the AE propagation velocity was calculated according to the time difference of arrival (TDOA). For clarity, the grain parallel direction was defined as 0 degrees, with velocities measured every 10 degrees through a counterclockwise rotation. Using these measurements, two angular anisotropic wave velocity models were developed. Subsequently, three AE sensors arranged linearly on the specimen surface pinpointed the AE source’s location. This source location problem was formulated as a multi-parameter optimization model, constrained by the geometric relationships between the AE source and the sensors. A particle swarm optimization (PSO) algorithm was utilized to estimate the AE source’s angles relative to each sensor. The findings indicate that the located AE sources deviated by 6.0–19.0 mm from the predetermined PLB positions, with inaccuracies largely attributed to the anisotropic AE wave velocity models’ precision.

Fault location technology for cable-overhead-hybrid transmission lines based on improved HOVMD-TKEO and wave velocity normalization method

Fault location technology for cable-overhead-hybrid transmission lines based on improved HOVMD-TKEO and wave velocity normalization method

Association between pulse wave velocity and cerebral microbleeds: a systematic review and meta-analysis.

Cerebral microbleeds are associated with events that are among the highest mortality and disability events combined worldwide, as well as with hypertensive vasculopathy. The aim of the present study was to investigate the relationship between a marker of hypertensive vasculopathy, arterial stiffness assessed by pulse wave velocity, and cerebral microbleeds. A systematic review and meta-analysis was performed using PubMed, Scopus, and Web of Science, according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Cochrane Collaboration Handbook statements. Data extraction, quality assessment and statistical analyses were performed following pre-established criteria. Twenty-one studies involving 18,436 participants were included. Higher levels of pulse wave velocity were associated with a higher presence of cerebral microbleeds p-OR = 1.26 (95% CI; 1.09-1.45), with considerable heterogeneity; even adjusting for potential confounding variables p-OR = 1.12 (95% CI, 1.05-1.20), with substantial heterogeneity. Only the percentage of women was related to p-OR in the adjusted model. Sensitivity analyses confirmed the robustness of our results. Adjusted models showed publication bias. Higher levels of arterial stiffness are associated with greater presence of cerebral microbleeds. This phenomenon may be caused by damage to the brain under higher blood flow loads, in turn due to age-induced reversal of the stiffness gradient between large and small vessels. As the world's population is undergoing demographic ageing, our results underline the importance of establishing pulse wave velocity as a cardiovascular marker for early screening and delaying the onset of the characteristic signs of both diseases.

Foot Sole Temperature Correlates with Ankle–Brachial Index, Pulse Wave Velocity, and Arterial Age in Diabetic Patients Without Diagnosis of Peripheral Arterial Disease

Background/Objectives: Some vascular alterations such as peripheral arterial disease (PAD) or arterial stiffness can alter perfusion of the limbs, so we wondered if this is reflected in the temperature of the soles of the feet of diabetic patients who did not have a diagnosis of peripheral arterial disease. Foot sole temperature was correlated with the ankle–brachial index (ABI), carotid—femoral pulse wave velocity (cfPWV), brachial–ankle pulse wave velocity (baPWV), and arterial age. Methods: A total of 175 patients with type 2 diabetes mellitus, without a previous diagnosis of PAD, were recruited. Comorbidities, anthropometry, biochemical analysis results, temperature, ABI, cfPWV, baPWV, and arterial age were recorded. Forty-two temperature records were obtained from the sole of the foot with an FLIR T865 thermal imaging camera. ABI, cfPWV, baPWV, and arterial age were obtained using plethysmographic and oscillometric methods. Statistical analysis was performed with SPSS v.29.0 (correlations and multiple linear regression models). Results: All temperature points analyzed correlated negatively with ABI (p < 0.001) and rho values ranged from −0.168 to −0.210. Likewise, cfPWV, baPWV, and arterial age had similar results, since most temperature records showed low rho values and a negative correlation with these parameters. Four models were developed to explain the variables of interest. Temperature was involved in all of them. The temperature of the first toe was included in the prediction of cfPWV, baPWV, and arterial age. Conclusions: There is an inversely proportional relationship between temperature and ABI, cfPWV, baPWV, and arterial age in diabetic patients without a previous diagnosis of arterial disease. Temperature can be a predictor of these hemodynamic variables.

Full wavefield modeling and dispersion characteristics of underwater MASW

The underwater multichannel analysis of surface wave (UMASW) is becoming an essential tool for surveying subbottom shear wave velocity. Current practice is limited to interpretation based on the fundamental mode. This paper investigates the full dynamic response of the underwater-multilayered structure under two different types of sources (impact and explosion). Fundamental solutions in the transformed domain, after applying both Fourier transform and Fourier–Bessel transform, are derived utilizing the global stiffness matrix method, analogous to a 1-D finite element approach. Solutions in the physical domain are then obtained using the fast and accurate Fourier series and Fourier–Bessel series approach proposed in this paper. The most attractive feature of this novel approach is that the expansion coefficients (or Love numbers) can be pre-calculated, saved, and repeatedly used for other field points. Through numerical analyses, we quantitatively investigate the effect of the water depth and source/receiver types/locations on different wave features (i.e., Scholte, fast-guided, and acoustic modes) from different perspectives (i.e., dispersion curve, Green’s function, frequency-velocity spectrum (FVS), and waveform). We find that (1) unlike the impact source, stronger acoustic waves can be produced by the explosive source, which sometimes causes difficulty in identifying the Scholte waves. (2) The acoustic and interface-guided waves exhibit distinct behaviors depending on the source and receiver locations. Scholte waves and fast-guided waves are weakened when the source and receivers are elevated far from the water/soil interface. Moreover, (3) the response of the Scholte wave can be enhanced by muting the direct acoustic waves. However, (4) the fast-guided wave may also arise in underwater surveys when the Vs of the underlying half-space is much higher than those of the upper layers, exerting a significant influence on the shallow water scenarios and posing challenges for correct mode identification. With the ability to model the entire wavefield (or FVS) that takes into account all propagation modes and the actual survey configuration, inversion can be performed by fitting the entire FVS. This approach eliminates the need to pick dispersion curves and provides a more accurate and stronger model constraint.

20-HETE, Blood Pressure, and Vascular Stiffness in Young Adults.

Cytochrome-P450 eicosanoids from arachidonic acid, including vasodilator epoxyeicosatrienoic acids (EETs) and the vasoconstrictor 20-HETE, are important in regulating blood pressure, vascular tone, and cardiac and renal function. This study examined plasma 20-HETE and EETs in relation to blood pressure and vascular stiffness in a cohort of 1054 community-dwelling young adults from the Raine Study at 27 years. Plasma 20-HETE, EETs, and their hydroxylated products were measured by liquid chromatography-tandem mass spectrometry. Pulse wave velocity and aortic distensibility were measured to assess vascular stiffness. Sex differences were assessed using univariate analysis. Multiple regression models assessed the relationship between 20-HETE and systolic blood pressure (SBP) and measures of vascular stiffness. The regression model for SBP showed a positive relationship with plasma 20-HETE (β, 0.092; P<0.0001), after adjusting for sex (P<0.0001), body mass index (P<0.0001), (ln)triglycerides (P<0.0001), and (ln)HOMA-IR (P=0.015), and accounted for 29% of the variance in SBP. 20-HETE was positively related to pulse wave velocity (β, 0.059; P=0.021); after adjusting for sex (P<0.0001), SBP (P<0.0001), (ln)triglycerides (P=0.014), (ln)HOMA-IR (P=0.0001), (ln)high-sensitivity C-reactive protein (P=0.005), and age (P=0.002), the model accounted for 34% of the variance in pulse wave velocity. 20-HETE was inversely associated with aortic distensibility (β, -0.051; P=0.029), independent of sex (P<0.0001), SBP (P<0.0001), and (ln)HOMA-IR (P<0.0001); the model accounted for 25% of the variance in aortic distensibility. Plasma EETs were not significant predictors of SBP or vascular stiffness. In young adults, 20-HETE may play a fundamental role in regulating blood pressure and vascular stiffness independent of numerous cardiometabolic risk factors and cytochrome 450-derived EETs. URL: https://www.anzctr.org.au; Unique identifier: CTRN12617001599369.

Structural evolution and magnetic, optical, and optoelectronic properties changes in annealed Co0.5Sr0.5Fe2O4 nanoparticles: A comprehensive study

A sample of Co0.5Sr0.5Fe2O4 nanoparticles was synthesized by the coprecipitation technique to explore the effect of annealing on the structure and some physical properties of the produced material. The coprecipitated sample consists of an orthorhombic strontium carbonate phase and the required cubic Co0.5Sr0.5Fe2O4. Annealing at elevated temperatures (900 °C) leads to the formation of cubic and hexagonal phases. This crystal structure was confirmed by X-ray diffraction analysis (XRD). The accuracy of the cation distribution of the cubic phase determined from the Rietveld analysis of XRD patterns is demonstrated by matching the experimental and theoretical lattice constants. There are several noticeable changes in aspects as the annealing temperature goes up. The transmission electron microscopy (TEM) images indicated that heating substantially affects the growth and densification of the smaller nanoparticles. There is a drop in the longitudinal and transverse wave velocities, bulk, rigidity, Young's moduli, Poisson ratio (σ), and Debye temperature (θD) with annealing and grain growth. The saturation magnetization and coercive field are enhanced with annealing. The particle size distribution calculated from TEM is confirmed and supported by the switching field distribution. The indirect optical bandgap energy (Eg) decreased with annealing. The present study concentrated on the thermal treatment impacts on various optical parameters, such as the refractive index and extinction coefficient. The optoelectrical parameters, such as the dielectric constant, dielectric loss, and optical and electrical conductivity, were extensively investigated, giving valuable insights, and their results were interpreted. These findings suggest potential applications in magnetic storage, sensors, and optoelectronics fields.

A Multiscale Mathematical Model for the Fetal Blood Circulation of the Second Half of Pregnancy.

Doppler ultrasound is a commonly used method to assess hemodynamics of the fetal cardiovascular system and to monitor the well-being of the fetus. Indices based on the velocity profile are often used for diagnosis. However, precisely linking these indices to specific underlying physiology factors is challenging. Several influences, including wave reflections, fetal growth, vessel stiffness, and resistance distal to the vessel, contribute to these indices. Understanding these data is essential for making informed clinical decisions. Mathematical models can be used to investigate the relation between velocity profiles and physiological properties. This study presents a mathematical model designed to simulate velocity wave propagation throughout the fetal cardiovascular system, facilitating the assessment of factors influencing velocity-based indices. The model combines a one-fiber model of the heart with a 1D wave propagation model describing the larger vessels of the circulatory system and a lumped parameter model for the microcirculation. Fetal growth from 20 to 40 weeks of gestational age is incorporated by adjusting cardiac and circulatory parameter settings according to scaling laws. The model's results, including cardiac function, cardiac output distribution, and volume distribution, show a good agreement with literature studies for a growing healthy fetus from 20 to 40 weeks. In addition, Doppler indices are simulated in various vessels and agree with literature as well. In conclusion, this study introduces a novel closed-loop 0D-1D mathematical model that has been verified against literature studies. This model offers a valuable platform for analyzing factors influencing velocity-based indices in the fetal cardiovascular system.

Problem of Surface Waves on Water in Higher School Laboratory Workshop

Traditionally, in lecture courses on General Physics, the example of waves propagating on the water surface is used for the qualitative description of wave phenomena. At the same time, in corresponding laboratory courses, there are almost no quantitative tasks on the same topic, the purpose of which would be to measure the surface wave characteristics. The reason for this difference must be associated with the complexity of the physical mechanism of generation and propagation of waves on the water surface. In this work, a laboratory problem has been developed to measure the group velocity of circular waves traveling on the water surface. It uses a standard laboratory water tank equipped with a surface wave generator. The proposed experiment offers an opportunity for quantitative measurement of surface wave characteristics, a dispute of only qualitative observations of wave phenomena commonly found in current curricula, due to the introduction of two improvements. First, to produce the water waves’ rich in-contrast representations on a screen, the optimal generator amplitude is specially set for each experiment; and second, to measure the group wavelength, the device magnification is preliminary calculated based on the laws of geometric optics. The tests carried out have shown that the relative accuracy of these measurements is quite acceptable: within a few percent. The introduction of the problem of surface waves on water into the General Physics laboratory workshop for engineering specialties of technical universities will contribute to improving the quality of mastering the subject by students.

Seismic site conditions of RESNOM network

The Northwest Seismic Network of Mexico (RESNOM) is operated by personnel from the Center for Scientific Research and Higher Education of Ensenada, Baja California (CICESE), which supervises station installation, improvement, and maintenance. We employed seismic noise and the Horizontal to Vertical Spectral Ratio (HVSR) method to determine, for each station, the following site condition parameters: the depth of the rock layer (Heng_bed), and the geotechnical parameter VS30, obtained from 1D shear wave velocity models. Other parameters as the fundamental frequency (f0) and the average amplitude at the fundamental frequency (A0) were also estimated. Our results show clear differences between the values obtained for the Mexicali Valley and the Peninsular ranges regions. The VS30 obtained for stations of the Mexicali Valley region falls in the range from 173 m/s to 535 m/s, while for the Peninsular Ranges region is between 213 m/s and 958 m/s. Regarding the Heng_bed parameter, the values are similar between both regions, from 23 m to 850 m for the Peninsular and from 42 m to 926 m for the Mexicali Valley. Additionally, from the VS30 values, we propose the site classification according to the U.S. National Earthquake Hazards Reduction Program (NEHRP).

Impact of arterial system alterations due to amputation on arterial stiffness and hemodynamics: a numerical study

Subjects with amputation of the lower limbs are at increased risk of cardiovascular mortality and morbidity. We hypothesize that amputation-induced alterations in the arterial tree negatively impact arterial biomechanics, blood pressure and flow behavior. These changes may interact with other biological factors, potentially increasing cardiovascular risk. To evaluate this hypothesis regarding the purely mechanical impact of amputation on the arterial tree, we used a simulation computer model including a detailed one-dimensional (1D) arterial network model (143 arterial segments) coupled with a zero-dimensional (0D) model of the left ventricle. Our simulations included five settings of the arterial network: (1) 4-limbs control, (2) unilateral amputee (right lower limb), (3) bilateral amputee (both lower limbs), (4) trilateral amputee (lower-limbs and right upper-limb), and (5) quadrilateral amputee (lower and upper limbs). Analysis of regional stiffness, as calculated by pulse wave velocity (PWV) for large-, medium- and small-sized arteries, showed that, while aortic stiffness did not change with increasing degree of amputation, stiffness of medium and smaller-sized arteries increased with greater amputation severity. Despite a staged decrease in cardiac output, the systolic and diastolic blood pressure values increased, resulting in an increase in both central and peripheral pulse pressures but with an attenuation of pulse pressure amplification. The most significant increase in peak systolic pressure and decrease in peak systolic blood flow was observed at the site of the abdominal aorta. Wave separation analysis indicated no changes in the shape of the forward and backward wave components. However, the results from wave intensity analysis showed that with extended amputation, there was an increase in peak forward wave intensity and a rise in the inverse peak of the backward wave intensity, suggesting potential alterations in cardiac hemodynamic load. In conclusion, this simulation study showed that biomechanical and hemodynamic changes in the arterial network geometry could interact with additional risk factors to increase the cardiovascular risk in patients with amputations.

Parallel multiple-chain DRAM probabilistic model for ultrasonic pulse velocity of concrete performance in the pipe of arch bridge

The existing models for predicting the compaction state of concrete inside steel tubes based on ultrasonic wave velocity have a major limitation in that they cannot comprehensively consider concrete compressive strength, instar, and various sources of uncertainties, both subjective and objective. To overcome this limitation, the study introduced a probability model for ultrasonic wave velocity in the concrete performance inside arch bridge steel tubes, based on the parallel multiple-chain Delayed Rejection Adaptive Metropolis (DRAM) algorithm. Initially, the study considers the influence of concrete compressive strength and instar, establishing a simplified deterministic model for predicting concrete compactness inside the tubes. Building on this, the study incorporates material stochastic uncertainty and cognitive uncertainty, deriving analytical expressions for a probabilistic prediction model of concrete compactness. Furthermore, using parallel processing alongside the DRAM algorithm, the study explores how the number of parallel chains and the order of acceptance probabilities influence the probabilistic model parameters. The study selected and updated the posterior distribution information of the probabilistic model parameters. Finally, the effectiveness of the model was validated using experimental data. As shown in the analysis, with better prediction accuracy and lower dispersion, the model not only selects the optimal Markov chain iteration path in a short time, but also corrects the parameters affecting the prediction accuracy of the existing model, and also provides a probabilistic method for correcting the confidence intervals of the existing model.

Diagnosis and management of Canine Renal Cell Carcinoma with special reference to Shear Wave Elastography

This report focuses on the diagnosis and surgical management of unilateral renal cell carcinoma in a 7-year-old male intact German Shepherd dog. The dog was presented with fever, haematuria, inappetence, infrequent bouts of emesis, and progressive weight loss. Palpation revealed a hard, round mass in the right cranial abdomen. A presumptive diagnosis of unilateral renal neoplasm was made based on clinical signs, haematobiochemical analysis, and radiography. B-mode ultrasound examination demonstrated an enlarged right kidney extending up to the ventral midline. The kidney exhibited heterogenous echotexture, loss of renal architecture, and only a small healthy portion at the caudal pole. Point Shear Wave Elastography analysis revealed elevated values both in terms Shear Wave Velocity (m/sec) and Young’s Modulus Stiffness Value (kPa), indicating the presence of renal malignancy. To treat the condition, unilateral nephroureterectomy was performed under general anaesthesia. Histopathological examination confirmed the diagnosis of renal cell carcinoma. Consequently, it can be concluded that B-mode ultrasonography, Point Shear Wave Elastography, and nephroureterectomy played crucial roles in the successful diagnosis and surgical management of unilateral renal cell carcinoma.

Association between estimated pulse wave velocity and the risk of mortality in patients with subarachnoid hemorrhage: a retrospective cohort study based on the MIMIC database

BackgroundThe estimated pulse wave velocity (ePWV) is a recently developed, simple and useful tool to measure arterial stiffness and to predict long-term cardiovascular mortality. However, the association of ePWV with mortality risk in patients with subarachnoid hemorrhage (SAH) is unclear. Herein, this study aims to assess the potential prediction value of ePWV on short- and long-term mortality of SAH patients.MethodsData of adult patients with no traumatic SAH were extracted from the Medical Information Mart for Intensive Care (MIMIC) III and IV database in this retrospective cohort study. Weighted univariate and multivariable Cox regression analyses were used to explore the associations of ePWV levels with 30-day mortality and 1-year mortality in SAH patients. The evaluation indexes were hazard ratios (HRs) and 95% confidence intervals (CIs). In addition, subgroup analyses of age, the sequential organ failure assessment (SOFA) score, surgery, atrial fibrillation (AF), renal failure (RF), hepatic diseases, chronic obstructive pulmonary disease (COPD), sepsis, hypertension, and diabetes mellitus (DM) were also performed.ResultsAmong 1,481 eligible patients, 339 died within 30 days and 435 died within 1 year. After adjusting for covariates, ePWV ≥ 12.10 was associated with higher risk of both 30-day mortality (HR = 1.77, 95%CI: 1.17–2.67) and 1-year mortality (HR = 1.97, 95%CI: 1.36–2.85), compared to ePWV < 10.12. The receiver operator characteristic (ROC) curves showed that compared to single SOFA score, ePWV combined with SOFA score had a relative superior predictive performance on both 30-day mortality and 1-year mortality, with the area under the curves (AUCs) of 0.740 vs. 0.664 and 0.754 vs. 0.658. This positive relationship between ePWV and mortality risk was also found in age ≥ 65 years old, SOFA score < 2, non-surgery, non-hepatic diseases, non-COPD, non-hypertension, non-DM, and sepsis subgroups.ConclusionBaseline ePWV level may have potential prediction value on short- and long-term mortality in SAH patients. However, the application of ePWV in SAH prognosis needs further clarification.