Wave Velocity Values Research Articles

A global solution to a hyperbolic problem for blood flow modelling

The paper aims to examine the hyperbolic system of equations governing one-dimensional haemodynamics and its relevance in analysing blood flow under mechanical influences, with particular emphasis on the impact of altering the angle of the leg axis. Methods and approaches for solving hyperbolic equations have been developed in light of their properties and characteristics. The primary objective of this study was to investigate the interplay between vein pressure, pulse wave velocity, and vascular distension. The study revealed an inverse relationship between vein pressure and pulse wave velocity. A decrease in pulse wave velocity occurs when vein pressure rises, and vice versa. Both real measurements and modelling results confirmed this dependence. The pressure in the veins is between 10.8 and 13.6 kPa, and the speed of the pulse wave is between 0.061 and 0.27 kPa. The agreement between real and model data was high. The modelled venous pressure and pulse wave velocity values are close to the actual values. However, it is essential to acknowledge the limitations of this paper. These limitations include the utilisation of one-dimensional haemodynamic models, which fail to consider the three-dimensional structure of the circulatory system. Additionally, the analysis is restricted to examining changes solely in the leg axis angle. The research helps to clarify the relationship between mechanical actions and haemodynamic parameters. The findings may help research and develop new methods for identifying and treating conditions associated with the cardiovascular system.

Normal value of virtual touch imaging quantification elastography in measurements of pancreas.

To evaluate pancreatic tissue stiffness and provide a normal reference shear wave velocity (SWV) value of pancreas from healthy adults by Virtual Touch Imaging Quantification (VTIQ) measurements. Healthy adult volunteers without known history of hepatobiliary or pancreatic diseases were included. VTIQ elastography (Siemens ACUSON Sequoia, 5C-1 transducer) was used. SWV values were measured at the cephalic, corpus and tail of pancreas and replicated different operators' obtained data. Subgroups were classified according to the volunteers' gender, age, body mass index (BMI), depth of measurements and the echogenicity of the pancreas. From February 2023 to July 2023, 33 healthy adult volunteers were included. The success rate of VTIQ measurements in cephalic, corpus and tail regions was 90.90 % (30/33), 96.97 % (32/33) and 90.90 % (30/33) respectively. The color elastograms of healthy adult pancreas showed uniform blue or simultaneously blue and green. The average SWV values were 0.97±0.26 m/s for cephalic, 0.91±0.24 m/s for corpus and 0.97±0.25 m/s for pancreatic tail respectively (P = 0.198). The mean SWV values of pancreas did not show significant difference with age, gender or depth (P > 0.05). BMI was an influence factor in the measurements of SWV values of cephalic and tail of pancreas (P < 0.05). Pancreas with hyperechoic parenchyma showed higher mean SWV values (P < 0.05). The intra-observer (ICC = 0.938 [95% CI: 0.869-0.971]) and the inter-observer (ICC = 0.887 [95% CI: 0.760-0.947]) agreements of VTIQ measurements were excellent. The mean SWV value of the pancreas in healthy adults was 0.96±0.20 m/s (range: 0.52-1.74 m/s). VTIQ technique can be used in pancreatic stiffness measurements with good reliability.

Petrophysical Analyses of Rock Construction Materials from a Roman Rural Settlement in Podšilo Bay on Rab Island (North-East Adriatic, Croatia).

This article presents the results of petrophysical analyses of limestones and sandstones used for the construction of the wall structures of a Roman rural settlement located in Podšilo Bay on Rab Island (Croatia). An on-site analysis of the walls indicated the use of different lithotypes, which is an uncommon case in the area. So far, no petrophysical properties of the applied materials have been tested, and their provenance has not been specified. The aim of this research was to determine their usability as construction materials in an attempt to determine the possible reasons behind the usage of multiple lithotypes and their suitability as building materials. The following procedure was used to address these issues: (1) determination of the petrographic characteristics of the rocks, (2) performance of tests to characterise the mechanical properties in a complex stress state of uniaxial tension followed by uniaxial and triaxial compression, and, finally, (3) determination of the internal structure of the rocks using methods based on X-ray imaging. Multi-proxy characteristics of the materials including numerous observations and methods were performed: optical microscopy used to characterise rock petrography and mineralogy, scanning electron microscopy (SEM) coupled with EDS, as well as grinding tests; furthermore, mechanical properties were determined on cylindrical samples in accordance with European standards. X-ray microtomography using the XμCT method enabled microscopic observations and determination of the orientation of discontinuities and the rock structure. The performed analyses allowed us to distinguish three lithological types of sandstone and two types of limestone among the examined stone blocks. Stone blocks of fine- and medium-grained sandstone with carbonate binders, as well as sparitic limestone and mudstone with calcite veins, were used to build the studied structures. The analysed blocks showed traces of partial edge processing. Despite the defects in the material structure identified using XμCT, all the types of rock were characterised by high or very high strength. High values of longitudinal wave velocity confirmed the good quality of the material. These results contribute to a better understanding of the construction process and the related technological choices, and they provide the first dataset which can be used for the reconstruction of the building's original appearance in the future.

Brachial-Ankle Pulse Wave Velocity is Associated with Incident Dementia in Patients with Cerebral Small-Vessel Disease.

Increased arterial stiffness is associated with the severity of cerebral small-vessel disease (SVD) and may predict incident dementia. This study investigated the predictive value of brachial-ankle pulse wave velocity (ba-PWV) for dementia and cognitive decline. Data were obtained from a Japanese cohort of 478 patients who underwent ba-PWV measurement. Magnetic resonance imaging (MRI) was used to evaluate SVD severity. The Mini-Mental State Examination (MMSE) and the Japanese version of the Montreal Cognitive Assessment (MoCA-J) were used to assess the cognitive function. The primary outcome was the incidence of dementia. The secondary outcome was cognitive change during three years of follow-up. The median age was 71 years old, 61% were men, and the median ba-PWV was 1787 cm/s. Dementia was diagnosed in 23 patients during a mean follow-up of 4.8 years. A Cox proportional hazard regression analysis revealed that the highest quartile (ba-PWV ≥ 2102 cm/s) was associated with a significantly higher risk of dementia than the first to third quartiles (ba-PWV ≤ 2099 cm/s) after adjusting for risk factors, the mean blood pressure, the MoCA-J score, and SVD severity (adjusted HR, 3.40; 95% CI, 1.24-9.34; P=0.018). Longitudinal cognitive changes in 192 patients indicated that ba-PWV was negatively related to changes in the MoCA-J score (r=-0.184, P=0.011). The decline in the MoCA-J score in the highest quartile was greater than that in the first to third quartiles after adjusting for risk factors, SVD severity, and baseline MoCA-J score (P=0.017). ba-PWV was associated with incident dementia and cognitive decline, independent of age, risk factors, the baseline cognitive function, and the SVD severity.

Relation between liquefaction resistance and shear modulus of crushable volcanic soils

Pumice-rich soils originating from volcanic eruptions are deposited in various parts of the world, such as in the central region of North Island, NZ. The pumice sand components of these natural pumiceous (NP) soils are known to be crushable and lightweight, resulting in a significant difference in their cyclic resistance ratio (CRR) and small-strain shear modulus (Gmax) when compared to hard-grained (quartz) sands. In this paper, the results of a number of cyclic triaxial and bender element tests performed on reconstituted specimens of three types of NP sands having different pumice contents (PC), as well as on quartz-type Toyoura sand specimens, are discussed. Then, the concept of modified cyclic yield strain, εay,m, which relates the CRR of the specimen to its Gmax, is used. The results indicate that εay,m appears to be dependent only on the soil type, and independent of the confining pressure applied and the relative density of the specimen. All NP sand specimens show higher εay,m when compared to Toyoura sand because of their higher CRR and lower Gmax, with values of εay,m increasing as the PC of the specimen increases. Based on the results obtained, an empirical chart is developed to estimate the CRR of NP sands from their shear wave velocity (Vs) values under field conditions.

Geological Mapping Optimisation Using Satellite Gravity, Satellite Imagery, and Seismic Shear Velocity (Vs30) to Monitor Lithological Condition in Geothermal Area of Mount Salak, West Java

Conventional geological mapping has several challenges such as limitation of area coverage, tough terrain, unstable weather condition, high-cost survey, also limitation of expert geologist that capable to do geological mapping. Remote sensing is an alternative solution to geological mapping through the combination of satellite gravity, satellite imagery, and seismic shear wave velocity. This research aims to optimise geological mapping activity in the Mount Salak geothermal area from ineffective area coverage mapping and inefficient budgeting allocation. Integration of rock density from satellite gravity, lithological distribution from satellite imagery, and seismic shear wave velocity from Vs30 are giving more detailed lithological units interpretation with specific physical conditions. There are two main area of Mount Salak that should be preserved geothermal resource sustainable. Northeast area needs to preserve heat source and groundwater recharge area, that consist of dense vegetation as landcover, relatively high rock density value (2.30 - 2.50 gr/cm3), high seismic shear wave velocity (600 – 900 m/s), also dominantly covers by Andesitic-Basaltic Lava. Southwest area preserve reservoir and caprock of geothermal conceptual model, where covers by dense vegetation with several bare land as geothermal wells and powerplants, relatively low rock density value (2.00 – 2.20 gr/cm3), moderate seismic shear wave velocity value (450-750 m/s), also dominated by several pyroclastic product such as Lapilli and Tuff. This research shows good indication in geothermal resource preservation in the Mount Salak, that keep natural aspect of geothermal conceptual model still preserved well.

Correlating Measured SPT-N, Shear Wave Velocity and Liquid Limit Values in Melekli Region, Igdır (Türkiye)

Characterization of soil layers underneath or having interaction with structures is substantially critical for the overall stability of structures under static and dynamic conditions. The main objectives in characterizing soil are mainly to determine ultimate bearing capacity, settlement, and liquefaction potential. Additionally, the dynamic behavior of soil during seismic excitation, as well as its interaction with structures, should be determined. In these regards, Standard Penetration Test blow counts (SPT-N) and shear wave velocity (Vs) values of soils obtained directly through field tests are known to reflect the soil characteristics, strongly. Therefore, any correlation between these two soil parameters is always in utmost interest. This study assesses the correlation between Vs and SPT-N values measured in Melekli region, Igdır (Türkiye). Moreover, four existing correlations in the literature are presented. The best-fit curve for the measured data is shown to divert from the existing correlation curves, which are also significantly different from each other, for all soils, sand, and clay soils. This can be attributed to the uniqueness of correlation to the study site as geological conditions at one site differ extensively from another site. There seems to be valuable correlation between Vs and water content and liquid limit in the studied area.

Estimating reference values of parenchymal stiffness of normal pancreatic parenchyma by means of point shear wave elastography.

There are numerous imaging modalities available to describe pancreatic parenchyma. None of the broadly accepted diagnostic methods uses elasticity as an indicator of tissue damage.

A new machine learning approach for estimating shear wave velocity profile using borelog data

The shear wave velocity is among the key parameters that are responsible for damage caused during an earthquake. Determining shear wave velocity is a costly and time-consuming direct geophysical method. In the present paper, a machine learning model has been developed to obtain the subsurface shear wave velocity profile without using direct methods. The bore log information and the subsurface shear wave velocity profile available at various stations of Japan’s Kyoshin network (K-NET) have been utilized for training this machine learning model. The parametric correlation study indicates that simple parameters like rock/soil type, the thickness of the layer in the model, and standard penetration test (SPT-N) value directly correlate with the medium’s shear wave velocity. A stacked ensemble machine learning model named VelProfES (an acronym for Velocity Profiler using Ensemble machine learning models) has been developed in this paper and has been utilized for effective prediction of the shear wave velocity profile using basic information from borelog data. The dataset used in the training and testing of the machine learning model consists of borelog and shear wave velocity information from 1101 stations. Of 1101 stations, 657, 283, and 71 stations have been utilized for training, testing, and validating the machine learning model. Training, testing, and validation of the developed machine learning model consist of parameters from 12351, 5279, and 1388 velocity layers. The problem of data imbalance based on soil type has been addressed using an additional 10510 layers of synthetic borelog data generated from conditional generative adversarial networks (CTGANs). A feature and model ablation study was conducted for the VelProfES model to provide substantiation for the model and feature selection choices. The predicted shear wave velocity profiles were compared at specific stations, focusing on average velocities at 5, 10, 15, and 20 depths. Further, the predicted values have been compared with the empirical relation of Sil and Haloi (2017) and a trained polynomial model. The machine learning model demonstrates close alignment between predicted and actual values across a broad spectrum of velocities, a contrast not observed in the empirical relation and polynomial model. The results show that the machine learning models and augmented data generated using CTGANs can efficiently minimize the error between actual and predicted subsurface shear wave velocity values.

MRI T2 mapping and quantitative ultrasound shear wave elastography in cartilage integrity assessment for juvenile idiopathic arthritis patients

BackgroundJuvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood that can lead to irreversible cartilage damage, with associated disability and decreased life quality. Shear wave elastography and quantitative MRI mapping can be used to identify early cartilage affection. PurposeTo evaluate diagnostic utility of distal femoral cartilage shear wave elastography and MRI T2 mapping in patients with symptomatic knee and investigate their potential clinical significance.Material and methodsTwenty patients with knee affection (study group) and 20 volunteers with the same demographic characteristics but without symptomatic knee pain (control group) were included in the study. A total of 80 knee joints of 40 individuals were evaluated. At the medial, intercondylar, and lateral condylar levels, distal femoral cartilage thickness was measured by B-mode ultrasonography and MRI, stiffness was assessed by shear wave elastography, and T2 relaxation time was measured by MRI.ResultsThe medial, intercondylar, and lateral cartilage thickness measurements were similar between the two groups and no statistically significant difference was observed while measured by US (P value 0.653,0.702,0.607) and MRI (P value 0.414, 0.4187, 0.3903). The shear wave velocity values in the study group were significantly higher than in the control group (P value 0.0202). There was a statistically significant difference between the average T2 relaxation time values for the distal femoral cartilage in the study and the control groups (P value 0.0027). SWE results were statistically significant in moderate and high disease activity while T2* revealed statistically significant p values in low as well as moderate and high disease activity; we found the best cutoff values for detection of cases using shear wave elastography velocity ratio (m/sec) about 4.445 with significant p value = 0.02, sensitivity 59.3% and specificity = 70.45%.ConclusionShear wave elastography and MRI T2 mapping are reliable, non-invasive, and acceptable methods for the assessment of pathologic cartilage. Better diagnostic information of hyaline cartilage can be obtained by adding up an extra sequence called T2 mapping to the routine MRI protocol of knee.

Tempol improves aortic mechanics in a mouse model of hypertension

Hypertension-induced arterial remodeling is thought to be a response to increases in both mechanical stress and oxidative stress. The superoxide dismutase mimetic Tempol has been shown to reduce adverse aortic remodeling in multiple murine models of hypertension but in the absence of a detailed assessment of the biaxial biomechanics. We show that concurrent treatment with Tempol in a common mouse model of systemic hypertension results in modest reductions in both wall thickening and circumferential material stiffness that yet work together to achieve a significant reduction in calculated aortic pulse wave velocity. Reducing elevated values of pulse wave velocity engenders multiple benefits to cardiovascular function.

Meta-analysis of randomized clinical trials on the speed of pulse wave propagation

This paper presents a theoretical analysis of the literature on the speed of pulse wave propagation using a combination of ECG and PPG signals. The diagnostic value of pulse wave velocity in medical practice is use of this indicator for non-invasive measurement of blood pressure and also for determination of arterial stiffness. Some studies have shown an association of pulse wave velocity with risk factors for cardiovascular disease. The speed of pulse wave propagation is an early marker and predictor of cardiovascular risk both in individuals with normal blood pressure and people with hypertension and is used as the "gold standard" for assessing arterial stiffness; however, the question about accuracy and automation of the measurement of the speed of pulse wave propagation still remains to be answered.

Gender-related differences in cardiometabolic risk factors and oxidative stress among prepubertal children with obesity.

Gender-related differences in oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors were examined in a cross-sectional study involving 313 prepubertal children (8-9 years old) from the generation XXI birth-cohort. Anthropometric measurements, cardiometabolic variables, and redox markers were assessed, including plasma and urinary isoprostanes (P-Isop, U-Isop), plasma total antioxidant status (P-TAS), serum myeloperoxidase (MPO), plasma and urinary nitrates and nitrites (P-NOX, U-NOX), and urinary hydrogen peroxide (U-H2O2). Girls showed higher levels of total/non-HDL cholesterol, triglycerides, and insulin resistance (HOMA-IR) compared to boys. Notably, U-H2O2 values were lower in girls. When stratifying by body mass index (BMI) and gender, both girls and boys exhibited higher MPO concentration and U-Isop values. Uric acid concentration was higher in overweight and obese girls than in normal weight girls, while no significant differences were observed among boys across BMI categories. Furthermore, U-NOX values differed only in boys, with higher levels observed in overweight and obese individuals compared to those with normal weight. Multivariate analysis, adjusted for age and BMI z-score, demonstrated inverse associations between U-H2O2 and pulse wave velocity values, as well as between U-NOX and total or non-HDL cholesterol, exclusively in boys. In girls, a positive association between U-Isop and HOMA-IR values was observed. In conclusion, gender differentially impacts oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors in prepubertal children. Prepubertal girls appear more susceptible to oxidative stress-induced metabolic dysfunction, while in boys, elevated levels of redox and nitric oxide bioavailability markers seem to provide protection against arterial stiffness and lipid homeostasis.

A cross-sectional study in type 2 diabetes patients reveals that elevated pulse wave velocity predicts asymptomatic peripheral arterial disease associated with age and diabetes duration

BackgroundPeripheral arterial disease (PAD) reduces functional capacity and raises cardiovascular risks, but underdiagnosis is common, resulting in less comprehensive care than other cardiovascular conditions. While diabetes has long been viewed as a key risk factor for PAD, recent studies indicate that its impact is influenced by the presence of concurrent cardiovascular risk factors. The aim of this study is to elucidate the intricate relationship between the prevalence of PAD, diabetic complications, and cardiovascular risk factors among asymptomatic patients with type 2 diabetes mellitus (T2DM). MethodsNinety-one patients with T2DM and no symptoms or previous diagnosis of PAD were recruited from the outpatient diabetic clinic. Clinical data were extracted from electronic medical records, and the screening for PAD was conducted using MESI mTABLET. ResultsScreening for PAD among asymptomatic individuals with T2DM revealed that 5.49 % of patients exhibit a low ankle-brachial index (ABI). Patients who had previously experienced major adverse cardiovascular events or exhibited albuminuria displayed lower ABI values. Furthermore, a striking 45.05 % of the participants displayed an abnormally high carotid-femoral pulse wave velocity (cfPWV) value, with elevated PWV values correlating with advanced age and longer diabetes duration. ConclusionsThe prevalence of elevated cfPWV is more pronounced than that of decreased ABI in T2DM patients with asymptomatic PAD and is associated with older age and longer diabetes duration, therefore measurement of both ABI and PWV is crucial for the cardiovascular risk assessment protocol for patients with T2DM and timely PAD diagnosis.

Ultrasonic Characterization of Polymer Based Sille Stone Powder Composite Mortars

The Sille stone mined in the Sille Region of Konya province in Türkiye, is an andesitic rock. This stone is a material used in the construction of traditional and modern buildings. The Sille stone is cut while being used in buildings. The Sille stone powder (SSP) is formed during this cutting process. The SSPs cause environmental pollution. Therefore, this study was carried out to produce durable and eco-friendly new restoration mortars from the SSP that can be used in the restoration of historical buildings. The SSP composites were prepared by contributing SSP into epoxy and polyester resins in varied ratios such as 60‒75 wt.%. The effect of resin types and SSP contribution ratios on the elastic properties of epoxy resin (ER)/SSP and polyester resin (PR)/SSP composites was investigated by the ultrasonic pulse-echo method. Additionally, the morphology of these composites was investigated by scanning electron microscopy (SEM). Experimental results figured out that both longitudinal and shear wave velocity values of the PR/SSP composites were higher than of the ER/SSP composites. Furthermore, a linear increase was observed in the elastic properties of obtained composites with the increasing amounts of SSP.

Seismic site characteristics for geotechnical engineering purposes: Case study, South of Ras Samadai, Red Sea, Egypt

Nowadays, geophysical techniques are widely employed in geotechnical research. Among the techniques that are frequently employed is the Multichannel Analysis of Surface Waves (MASW) technique, it aims to depict spatial differences in physical characteristics of the subsurface layers. The aim of the current research is to produce multiple maps for the seismic site classification (SSC) and dynamic characteristics along the study area located on the Red Sea shoreline of Egypt, south of Ras Samadai. In order to achieve this goal MASW surveys have been conducted in the current study, and corresponding 1D-shear wave velocity profiles have been generated. Consequently, to trace the stiffness change in the subsurface layers, the study provides a series of maps using the shear wave velocity (Vs) values at different depths to help the geotechnical engineers to identify and mitigate the geotechnical potential risk. Additionally, The Vs30 map for the study site is prepared and classified in accordance with the EC8 classification system. Referring to the obtained Vs30 map, the study region is mostly described as category B, with limited zones falling under classes A and C. Moreover, the soil's dynamic properties, including soil amplification and site natural period have already been taken in consideration. Approximately, the whole region exhibits low-to-moderate amplification values. However, two constrained zones are significantly more susceptible to amplification. Furthermore, the studied area is divided into six separate zones according to the obtained isoperiod map. The obtained results could be applied to engineering problems contribute to soil to avoid the probable obstacles during construction on soft soil.

Geotechnical variability of the soils of Quito, Ecuador: a geodatabase study

This paper presents a new geotechnical database for the soils of Quito, Ecuador. The geotechnical database is then used to investigate the best fit probability distributions for the key geotechnical parameters contained in the database. Using the Akaike information criteria for best fit selection, SPT (N), plasticity index, Vs30, peak friction angle (direct shear), and apparent cohesion (triaxial) are best represented by a Weibull distribution. The peak friction angle (triaxial) is best fitted with a truncated normal distribution. The database is also used to develop transformation models to allow for the estimation of more complex geotechnical parameters from intrinsic ones. This analysis shows that the transformation model between Vs30 and SPT (N) has high coefficients of determination and is statistically significant. Finally, the systematic collection of information in the database is used to investigate the assumption, based on engineering judgement by local practitioners, that soil derived from volcanic deposits and volcano-lacustrine sediments in the northern part of Quito has different geotechnical properties with respect to the southern zone of the city beyond the value of shear wave velocity whose difference is embedded in the soil classification map of the seismic code.

Liquefaction of industrial zone against earthquake loading using laboratory and field measurements

Purpose. To assess the liquefaction of Kirkuk’s industrial region following a series of earthquakes that struck the city during the previous five years based on the current earthquake activity in the region. Methodology. Initially, substantial relationships for shear wave velocity in different types of soil were collected and studied, where the majority of these correlations necessitated the use of standard penetration tests in the field. Indeed, two boreholes were drilled up to a maximum depth of 10 m, and the numbers of blows for conventional penetration tests were measured at various depths in each borehole. The stated shear wave velocity values from the literature, as well as the maximum and lowest shear wave velocity constraints, were employed in a simple technique to estimate the cyclic shear stress induced by earthquake loading. Findings. Based on laboratory and field data, the safety factor against earthquake-induced liquefaction can be determined. When the worst-case scenario was examined using the suggested values of shear wave velocity, the factor of safety against earthquake was reduced by 94 % as the depth increased from 3.5 to 9 m. Originality. No previous study has tried to quantify the liquefaction impact of industrial zone of Kirkuk city as such an important rich-oil area was influenced by series of earthquakes occurrence. More importantly, for the first time field soil samples from on-site boreholes in Kirkuk city have been collected and used for liquefaction assessment since such real field data can be utilized properly in liquefaction evaluation process in the absence of any comparable quantification for the investigated area. Practical value. Precious liquefaction analysis should be performed prior to any proposed project construction in the light of increased earthquake activity in the industrial zone in Kirkuk city (Iraq).

Role Of Shear Wave Elastography In Assessment Of Placental Elasticity In Normal And High-Risk Pregnancies In Third Trimester.

To assess the elasticity of placenta using shear wave elastography in normal and high-risk pregnancies in the third trimester. The prospective, observational study was conducted at the Dow Institute of Radiology, Dow University of Health Sciences, Karachi, from September 15, 2022, to January 15, 2023, and comprised singleton pregnant women during 28-40 weeks of gestation who were referred from the obstetric department. The subjects were divided into normal pregnancy group A and high-risk pregnancy group B. Risk factors include gestational hypertension, gestational diabetes, intrauterine growth restriction, placenta previa, morbidly adherent placenta, old primigravida, teen age and morbid obesity were noted. All the patients underwent grey scale, Doppler ultrasonography and shear wave elastography. Data was analysed using SPSS 26. Of the 104 subjects, 78(75%) were in group A and 26(25%) were in group B. The overall mean age was 34.2±3.59 years. In group B, mean placental shear wave velocity was 2.34±1.17m/sec and elasticity was 24.41±25.51kPa compared to 1.42±0.55 m/sec and 13.6±10.23kPa in group A (p<0.05). Significant positive correlation was found between shear wave velocity and elasticity values in both groups (p<0.001). Shear wave elastography was found to be a useful technique in detecting placental stiffness, and can be used as an adjunct to the currently available ultrasonographic methods in high-risk pregnancies.

Study of indicators of arterial stiffness in young people depending on ‘classical’ and ‘modern’ risk factors

Objective. To identify ‘classical’ and ‘modern’ risk factors (RFs) in young people aged 18–25 years in a student environment and evaluate their impact on arterial wall stiffness using non-invasive examination methods.Materials and methods. 171 students of a humanitarian university aged 18–25 years old were examined, of which 52.1 % were girls and 47.9 % were boys. An anonymous survey was conducted to identify the main risk factors. The method of volumetric sphygmography and highly sensitive compression oscillometry was used to assess the state of the vascular wall.Results. Against the background of ‘classic’ risk factors (low physical activity – 61.9 %, essential arterial hypertension [AH] – 29.8 %, aggravated heredity for hypertension – 18.3 %, overweight – 14.0 %, obesity – 8.5 %, cigarette smoking – 3.0 %), ‘modern’ RFs were identified: a combination of hookah and cigarette smoking – 31.0 %, use of electronic cigarettes – 17.0 %, use of energy drinks – 25.3 %. In students with the presence of ‘modern’ PR, the values of pulse wave velocity (PWV) were obtained – 8.4 ± 2.7 m/s, relative to the PWV of students without PR 5.1 ± 0.6 m/s (p = 0.002). It was found that the relative risk of an increase in PWV with the combined use of hookah and cigarettes increases by 52.1 times (95 % CI: 11.2–242.1 at χ2 = 37.987; p = 0.001), with the use of energy drinks by 27.4 times (95 % CI: 6.8–111.0 at χ2 = 29.328; p = 0.001), when using electronic cigarettes by 2.6 times (95 % CI: 1.3–5.2 at χ2 = 6.496; p = 0.011).Conclusions. Students aged 18–25 years showed a high adherence to modern risk factors (a combination of hookah and cigarette smoking, energy drinks, use of electronic cigarettes) that lead to a violation of the elastic properties of the vascular wall, which indicates endothelial dysfunction.