Pulse Wave Research Articles

Experimental Study of Electrical-Assisted Nanomachining of Monocrystalline Copper Using Customized Tungsten Tip

As a promising micro/nanofabrication method, electrical-assisted nanomachining has obtained substantial attention due to its high material removal rate and attainable superior surface quality. In this study, a rectangular wave electrical signal was applied for nanomachining by a customized tungsten tip. Owing to the coupling effect between the electric field and mechanical force, the cutting depth of the machined grooves can be expanded. In electrical-assisted groove processing, a depth of 270 nm and an aspect ratio of 0.6 on the copper sample can be achieved. The influence of operation parameters including applied voltage, frequency, duty ratio, normal force and cutting speed on the machining performance was investigated in terms of the groove depth, width, aspect ratio, and surface roughness. The potential machining mechanisms should be a combination of electric field force, nanoscale electric discharge, electric contact thermal effects, possible annealing behavior, and scraping and plowing actions induced by mechanical forces.

Lamb waves-based PCF-DMA: An anti-interference synchronous independent data transmission scheme for multiple cross-space users

Due to the high cost and safety risk brought about by wire penetration within the aerospace and underwater structure, reliable wireless cross-space multiple access transmission techniques become highly necessary. Lamb waves data transmission is recognized as a feasible solution, since it utilizes the solid structures as the transmission medium without being affected by electromagnetic radiation. However, in the case of synchronous transmission of multiple users, the aggravation of inter-access interference would severely weaken the reliability of the transmission system. Focusing on the issue of anti-interference synchronous independent data transmission for multiple cross-space users, this study proposes a Lamb waves-based pulse code frequency division multiple access (PCF-DMA) scheme. Firstly, a fast pulse position modulation strategy is established to improve the transmission rate. Considering the characteristics of the Lamb waves excitation pulses as the codeword, a PCF-DMA multiple access encoding method is designed. Secondly, by sparsely representing the Lamb waves physical transmission channel, a shift-invariant sparse deconvolution technology is proposed for decoding. Specially, to achieve reliable multiple access transmission with the PCF-DMA scheme, a normalized cross-correlation coefficient is used as the design criterion of the Lamb wave pulses. To validate these concepts, a three-user PCF-DMA data transmission system based on Lamb waves is built. The experimental results illustrate that the proposed design criterion can accurately predict the reliability of the multiple access transmission system. The bit error rate (BER) of the proposed PCF-DMA scheme is 30 % lower than that of conventional FDMA within a signal-to-noise ratio of −12 to 8 dB. Further, the influence factor analysis for the BER and communication rate are conducted. Finally, a synchronous independent data transmission for multiple cross-space users is achieved, with a maximum communication rate of 92.9 kbps per user and a BER below 0.17 %.

Non-Invasive Assessment of Micro- and Macrovascular Function after Initiation of JAK Inhibitors in Patients with Rheumatoid Arthritis.

Janus kinase (JAK) inhibitors constitute a novel class of oral biologic disease-modifying antirheumatic drugs for patients with rheumatoid arthritis (RA). However, their use has been associated with increased risk of major cardiovascular events. We investigated whether treatment with JAK inhibitors exerts significant alterations in the micro- and microvasculature in RA patients. Thirteen patients with RA initiating treatment with JAK inhibitors were prospectively studied. Eventually, data from 11 patients who completed the study were analyzed. Procedures were performed at baseline and 3 months after treatment. Nailfold videocapillaroscopy was applied to detect alterations of the dermal capillary network. Participants underwent 24 h ambulatory blood pressure monitoring (Mobil-O-Graph device) for the assessment of blood pressure (both brachial and aortic) and markers of large artery stiffening [pulse wave velocity (PWV), augmentation index] throughout the whole 24 h and the respective day- and nighttime periods. Carotid intima-media thickness was assessed with ultrasound. Three-month treatment with JAK inhibitors was not associated with any differences in brachial and aortic blood pressure, arterial stiffness, and carotid atherosclerosis, with the only exception of nighttime PWV, which was significantly elevated at follow-up. However, three-month treatment with JAK inhibitors induced significant microvascular alterations and increased the total number of capillaroscopic abnormalities. Three-month treatment with JAK inhibitors may exert significant effects on microcirculation as assessed with nailfold videocapillaroscopy, whereas macrovascular structure and function appears largely unaffected. Further research toward this direction may add substantial information to the available literature regarding cardiovascular aspects of JAK inhibitors in RA.

Angiopoietin-2, vascular endothelial growth factor family, and heparin binding endothelial growth factor are associated with subclinical atherosclerosis in rheumatoid arthritis

IntroductionPatients with RA are at a higher risk of developing CV diseases than the general population. The precise mechanisms are still unknown. We evaluated the associations between 8 plasma growth factors (GFs) (angiopoietin-2, EGF, HB-EGF, PLGF, TGF-α, VEGFa, VEGFc, and VEGFd) and subclinical arteriosclerosis in RA patients. Materials and methodsA total of 199 patients with RA treated at the Hospital Universitari Sant Joan de Reus (Spain) between 2011 and 2015 were included in this cross-sectional study. Carotid intima media thickness (cIMT), carotid plaque presence (cPP) and pulse wave velocity (PWV) were measured. GFs were measured with Bio-Plex Pro Human Cancer Biomarker Panel 2 (Bio-Rad). Multivariate models and partial least square discriminant analysis (PLS-DA) were used for analysis (RStudio, version 4.0.1). ResultsMultivariate models showed that angiopoietin-2 was associated with cPP and PWV in the overall cohort (OR = 1.53 and β = 0.20, respectively). VEGFc (β = 0.29), VEGFa (β = 0.26) and HB-EGF (β = 0.22) were also associated with PWV. VEGFa (OR = 2.36), VEGFd (OR = 2.29), EGF (OR = 2.62), PLGF (OR = 2.54), and HB-EGF (OR = 2.24) were associated with cPP in men. According to PLS-DA, GFs were able to distinguish between patients with and without cPP in the overall cohort, male cohort, and female cohort. In women, angiopoietin-2 was associated with PWV (β = 0.18). ConclusionsThe selected GFs were closely related to atherosclerosis in patients with RA and are potential predictors of CV disease in patients with RA.

Law Enforcement Officers Have an Increased Prevalence of Subclinical Cardiovascular Disease That is Not Explained by Traditional Risk Factors

ABSTRACT Objectives Determine if law enforcement officers develop subclinical atherosclerotic cardiovascular disease (ASCVD) earlier than non-officers and if so, the extent to which conventional risk factors explain this difference. Methods Estimated pulse wave velocity (ePWV) was the marker of subclinical ASCVD. EPWV, ASCVD risk factors, metabolic syndrome (MetS), and 10-year risk for ASCVD were compared among 408 law enforcement officers and a civilian cohort. Results EPWV, 10-year ASCVD risk, and MetS prevalence increased significantly with age. All but the officers age 55 and older had higher ePWV cohort than the civilian cohort (p < .001). Ten-year ASCVD risk explained the most variability of ePWV (R2 = .49, p < .001). Conclusions Officers develop subclinical ASCVD earlier than non-officers. Conventional ASCVD risk factors only explain about half of this increase. Occupational factors may play a role in contributing to this increased ASCVD risk.

Wave pulses’ physical properties in birefringent optical fibres containing two vector solitons with coupled fractional LPD equation with Kerr’s law nonlinearity

Wave pulses’ physical properties in birefringent optical fibres containing two vector solitons with coupled fractional LPD equation with Kerr’s law nonlinearity

Thermo-Mechano-Chemical Processing of Printed Circuit Boards for Organic Fraction Removal

Printed circuit boards (PCBs) are the main components of e-waste. In order to reduce the negative impact of waste PCBs on human health and the environment, they must be properly disposed of. A new method is demonstrated for recycling waste PCBs. It is referred to as the high-temperature thermo-mechano-chemical gasification (TMCG) of PCBs by the detonation-born gasification agent (GA), which is a blend of H2O and CO2 heated to a temperature above 2000 °C. The GA is produced in a pulsed detonation gun (PDG) operating on a near-stoichiometric methane–oxygen mixture. The PDG operates in a pulsed mode producing pulsed supersonic jets of GA and pulsed shock waves possessing a huge destructive power. When the PDG is attached to a compact flow reactor filled with waste PCBs, the PCBs are subject to the intense thermo-mechano-chemical action of both strong shock waves and high-temperature supersonic jets of GA in powerful vortical structures established in the flow reactor. The shock waves grind waste PCBs into fine particles, which undergo repeated involvement and gasification in the high-temperature vortical structures of the GA. Demonstration experiments show full (above 98%) gasification of the 1 kg batch of organic matter in a setup operation time of less than 350 s. The gaseous products of PCB gasification are mainly composed of CO2, CO, H2, N2, and CH4, with the share of flammable gas components reaching about 45 vol%. The solid residues appear in the form of fine powder with visible metal inclusions of different sizes. All particles in the powder freed from the visible metal inclusions possess a size less than 300–400 μm, including a large fraction of sizes less than 100 μm. The powder contains Sn, Pb, Cu, Ni, Fe, In, Cd, Zn, Ca, Si, Al, Ti, Ni, and Cl. Among these substances, Sn (10–20 wt%), Pb (5–10 wt%), and Cu (up to 1.5 wt%) are detected in the maximum amounts. In the powder submitted for analysis, precious elements Ag, Au, and Pt are not detected. Some solid mass (about 20 wt% of the processed PCBs) is removed from the flow reactor with the escaping gas and is partly (about 10 wt%) trapped by the cyclones in the exhaust cleaning system. Metal inclusions of all visible sizes accumulate only in the flow reactor and are not detected in powder samples extracted from the cyclones. The gasification degree of the solid residues extracted from the cyclones ranges from 76 to 91 wt%, i.e., they are gasified only partly. This problem will be eliminated in future work.

Assessment of arterial rigidity and daily profile of arterial pressure in women with newly detected breast cancer

Research objective: to evaluate arterial stiff ness indicators and its correlation with parameters of 24-hour ambulatory blood pressure monitoring (ABPM) in women with newly diagnosed breast cancer (BC).Material and methods: a prospective cohort study in 158 women aged 27 to 64 years with a median age of 45.4 years and newly diagnosed BC at stage IIA–IIIB before chemotherapy was conducted. The first group included 109 patients with normal or high-normal office blood pressure (BP), and the second group included 49 women with previously diagnosed stage 1– 2 essential hypertension (EH) with low or moderate cardiovascular risk. All patients underwent indirect arteriography and ABPM. Results. According to ABPM data, “masked” arterial hypertension (MAH) was diagnosed in 54 (49.5%) women in the fi rst group. In patients with MAH, the mean daily level and diastolic BP time index exceeded the corresponding indicators in EH, and the magnitude of the morning rise in systolic BP was significantly lower. In 35.4% of the examined patients with EH, the pulse wave velocity (PWV) was increased, and in 17.4% it was pathological. With MAH, these changes were recorded in 28.5% and 14.1% of cases, respectively. The odds ratio showed that in women with normal BP, the probability of an increase in PWV >10 m/s increased by 1.6 times, and in the presence of comorbidity with MAH and EH, it increased by 2.2 and 2.4 times, respectively. The risk of an increase in central systolic BP >125 mm Hg and pulse BP >60 mm Hg was highest in patients with EH.Conclusion: Among young and middle-aged women with newly diagnosed BC, a significant number of cases of MAH and EH are detected, which determines the need to evaluate arterial stiff ness and daily BP profiles before starting antitumor therapy.

Shock Response of Polymethyl Methacrylate (PMMA) Under Explosive Loading

AbstractThe dynamic response of polymethyl methacrylate (PMMA) is well understood for one-dimensional planar impact shocks, but limited research has been performed on the response of PMMA under spherical shock loading. In this work, the shock decay of an explosively-driven shock wave into PMMA was experimentally measured. PMMA cubes of various geometries were explosively loaded with an RP-80 detonator to produce the explosive shock wave. High-speed schlieren imaging was implemented to measure the explosively-driven shock wave velocity throughout the PMMA cubes. Photon Doppler velocimetry (PDV) was used to measure the particle velocity imparted by the shock wave at the surface of the cubes. The material shock response was studied at distances from 21.91 to 133.3 mm from the explosive source. The particle velocity history measured by PDV was compared to the wave profile visualized in the high-speed images. The shock wave pulse amplitude decreased with increased distance from the source. The conducted experiments extend the PMMA shock Hugoniot relating to the lower shock and particle velocity regime.

12,13-diHOME attenuates high glucose-induced calcification of vascular smooth muscle cells through repressing CPT1A-mediated HMGB1 succinylation

Diabetes is closely associated with vascular calcification (VC). Exorbitant glucose concentration activates pro-calcific effects in vascular smooth muscle cells (VSMCs). This study enrolled 159 elderly patients with type 2 diabetes and divided them into three groups, T1, T2 and T3, according to brachial-ankle pulse wave velocity(BaPWV). There were statistically significant differences in the waist circumference, waist hip ratio, systolic blood pressure, 12,13-diHOME (a lipokin) concentration among T1, T2 and T3. 12,13-diHOME levels were positively correlated to high density lipoprotein cholesterol and total cholesterol, but negatively correlated to with waist circumference, waist hip ratio, systolic blood pressure and baPWV. Studies in vitro showed that 12,13-diHOME effectively inhibits calcification in VSMCs under high glucose conditions. Notably, 12,13-diHOME suppressed the up-regulation of carnitine O-palmitoyltransferase 1 (CPT1A) and CPT1A-induced succinylation of HMGB1. The succinylation of HMGB1 at the K90 promoted the protein stability and induced the enrichment of HMGB1 in cytoplasm, which induced the calcification in VSMCs. Together, 12,13-diHOME attenuates high glucose-induced calcification in VSMCs through repressing CPT1A-mediated HMGB1 succinylation.

Hierarchical Piezoelectric Composites for Noninvasive Continuous Cardiovascular Monitoring.

Continuous monitoring of blood pressure (BP) and multiparametric analysis of cardiac functions are crucial for the early diagnosis and therapy of cardiovascular diseases. However, existing monitoring approaches often suffer from bulky and intrusive apparatus, cumbersome testing procedures, and challenging data processing, hampering their applications in continuous monitoring. Here, a heterogeneously hierarchical piezoelectric composite is introduced for wearable continuous BP and cardiac function monitoring, overcoming the rigidity of ceramic and the insensitivity of polymer. By optimizing the hierarchical structure and components of the composite, the developed piezoelectric sensor delivers impressive performances, ensuring continuous and accurate monitoring of BP at Grade A level. Furthermore, the hemodynamic parameters are extracted from the detected signals, such as local pulse wave velocity, cardiac output, and stroke volume, all of which are in alignment with clinical results. Finally, the all-day tracking of cardiac function parameters validates the reliability and stability of the developed sensor, highlighting its potential for personalized healthcare systems, particularly in early diagnosis and timely intervention of cardiovascular disease.

Endothelial dysfunction influences augmented aortic hemodynamic responses to metaboreflex activation in postmenopausal women.

Postmenopausal women experience augmented aortic hemodynamic responses to isometric handgrip (IHG) exercise and metaboreflex activation post-exercise muscle ischemia (PEMI). Relationships between endothelial function brachial artery flow-mediated dilation (FMD) and aortic stiffness carotid-femoral pulse wave velocity (cfPWV) with aortic pulsatile hemodynamics during IHG and PEMI have not been determined. The relationships between aortic hemodynamic responses to PEMI were evaluated. Aortic blood pressure (BP), wave reflection, and pressure of forward (Pf) and backward (Pb) waves were measured using arterial tonometry at rest, IHG at 30% maximal force, and PEMI in 30 (15/group) postmenopausal women with low (≤ 4.5%) and normal (≥ 5.5%) FMD. Hemodynamic responses were analyzed as the change (Δ) from rest to the last minute of IHG and PEMI. Brachial and aortic systolic BP (SBP) responses to IHG were higher in the low vs normal FMD group (P < 0.05). Aortic SBP (Δ20 ± 8 vs Δ11 ± 7mmHg), pulse pressure (PP) (Δ12 ± 8 vs Δ6 ± 4mmHg), augmented pressure (AP) (Δ5 ± 3 vs Δ2 ± 2mmHg), and Pb (Δ6 ± 4 vs Δ3 ± 2mmHg) responses to PEMI were greater (P < 0.05) in women with low vs. normal FMD. FMD was negatively correlated with aortic SBP, PP, AP, and Pb (P < 0.05) responses to PEMI. cfPWV was not correlated with responses to PEMI. Endothelial dysfunction relates to augmented aortic pulsatile load during metaboreflex activation, which may increase cardiovascular risk in postmenopausal women.

Cardiac MRI evaluation of aortic biophysical properties in paediatric Turner syndrome.

Aortopathy in Turner syndrome is associated with aortic dilation, and the risk of dissection is increased when the aortic size index is ≥ 2-2.5 cm/m2. We evaluated the aortic biophysical properties in paediatric Turner syndrome using cardiac MRI to determine their relationship to aortic size index. Turner syndrome patients underwent cardiac MRI to evaluate ventricular function, aortic dimensions, and biophysical properties (aortic stiffness index, compliance, distensibility, pulse wave velocity, and aortic and left ventricular elastance). Spearman correlation examined correlations between these properties and aortic size index. Data was compared to 10 controls. Of 25 Turner syndrome patients, median age 14.7 years (interquartile range: 11.0-16.8), height z score -2.7 (interquartile range: -2.92 - -1.54), 24% had a bicuspid aortic valve. Turner syndrome had increased diastolic blood pressure (p < 0.001) and decreased left ventricular end-diastolic (p < 0.001) and end-systolic (p = 0.002) volumes compared to controls. Median aortic size index was 1.81 cm/m2 (interquartile range: 1.45-2.1) and 7 had an aortic size index > 2 cm/m2. Aortic and left ventricular elastance were greater in Turner syndrome compared to controls (both p < 0.001). Increased aortic size index correlated with increased aortic elastance (r = 0.5, p = 0.01) and left ventricular elastance (r = 0.59, p = 0.002) but not aortic compliance. Higher ascending aortic areas were associated with increased aortic compliance (r = 0.44, p = 0.03) and left ventricular elastance (r = 0.49, p = 0.01). Paediatric Turner syndrome with similar aortic size index to controls showed MRI evidence of abnormal aortic biophysical properties. These findings point to an underlying aortopathy and provide additional parameters that may aid in determining risk factors for aortic dissection.

Study Protocol of a Prospective, Monocentric, Single-Arm Study Investigating the Correlation of Endograft Properties with Aortic Stiffness in Abdominal Aortic Aneurysm Patients Subjected to Endovascular Aortic Repair.

The number of endovascular aortic repairs (EVARs) has surpassed the number of open surgical repairs of abdominal aortic aneurysms (AAAs) worldwide. The available commercial endoprostheses are composed of materials that are stiffer than the native aortic wall. As a consequence, the implantation of stent-graft endoprostheses during EVAR increases aortic rigidity and thus aortic stiffness, resulting in a decrease in abdominal aorta compliance. EVAR has been found to have a possibly harmful effect not only on heart functions but also on other vascular beds, including kidney function, due to the decrease in aortic compliance that it causes. Aortic stiffness is measured by various hemodynamic indices like the pulse wave velocity (PWV), the central aortic pressure (CAP), and the augmentation index (AIx). In the literature, there are increasing numbers of studies investigating the properties of endografts, which are strongly related to increases in aortic stiffness. However, there is a lack of data on whether there is a correlation between the length of various endografts implanted during EVAR and the increase in the PWV, CAP, and AIx postoperatively compared to the preoperative values. The aim of this prospective, observational, monocentric, single-arm study is to investigate the correlation between endograft length and the postoperative increase in the PWV, CAP, and AIx in patients subjected to EVAR. Additionally, this study intends to identify other endograft properties related to increases in the PWV, CAP, and AIx. Other endpoints to be studied are the existence of immediate postoperative myocardial and kidney injury after EVAR. The prediction of cardiovascular events caused by endograft-related increased aortic stiffness could contribute to the improvement of various endograft properties so that the impact of endografts on the native aortic wall can be minimized.

Changes in the cardiovascular profile in patients 3 and 12 months after COVID-19 pneumonia: parameters of arterial stiffness, global longitudinal strain, and diastolic function of the left ventricle

Aim. To study changes in the brachial – ankle pulse wave velocity (baPWV), ankle – brachial index (ABI), diastolic function, and global longitudinal strain of the left ventricle (LV) 3 and 12 months after COVID-19 pneumonia.Materials and methods. The dynamics of vascular age and LV global longitudinal strain was studied in 154 patients 3 and 12 months after COVID-19 pneumonia (51 ± 12 years, 48% were women). The control group consisted of 55 sexand age-matched individuals.Results. During the follow-up, the average baPWV decreased (13.2 [11.8; 15.1] cm / sec vs. 13.0 [11.8; 14.1] cm/ s; p &lt; 0.001), and the frequency of its elevated values declined (45.4 vs. 35.1%; p = 0.008). The average ABI increased (1.09 [1.04; 1.14] vs. 1.11 [1.06; 1.17]; p = 0.012), but remained within the normal range. LV global longitudinal strain (LV GLS) (–19.6 ± 2.2 and –19.7 ± 2.5%; p = 0.854) and the frequency of reduced LV GLS (21.4 and 26.6%; p = 0.268) did not change significantly and did not differ from values in the control group. Global longitudinal strain in the LV basal inferoseptal segment improved (–19.2 ± 3.6% vs. –20.1 ± 4.0%; p = 0.032). The early diastolic mitral annular velocity decreased (8.4 ± 3.0 cm / s vs. 8.0 ± 2.5 cm / s; p = 0.023). The LV isovolumic relaxation time was greater than in the control group (101.8 ± 22.3 ms at the 1st visit vs. 92.9 ± 21.5 ms; p = 0.012; 105.9 ± 21.9 ms vs. 92.9 ± 21.5 ms at the 2nd visit; p &lt; 0.001). A positive correlation was found between baPWV (r = 0.209; p = 0.009) and ABI (r = 0.190; p = 0.021) and strain parameters of the LV basal segments 12 months after discharge.Conclusion. Patients with optimal visualization on echocardiography at 12 months after COVID-19 pneumonia, compared to the results of the examination 3 months after the disease, had deteriorated parameters of LV diastolic function. LV GLS was within the grey zone and did not change significantly. An improvement in arterial stiffness was noted, associated with an improvement in the strain of basal LV segments.

Numerical Simulation Study on Impact Initiation on Shielded Charge Using Hypervelocity Composite-Structure Reactive Fragments.

In order to study the impact initiation process and mechanism of hypervelocity PTFE/Al composite structure reactive fragments on a shielded charge, first, an existing PTFE/Al reactive fragment hypervelocity collision experiment was numerically simulated using the SPH algorithm in ANSYS/AUTODYN 17.0 software. Then, the Lee-Tarver model was verified to describe the detonation reaction behavior and explosion damage effect of reactive materials. A numerical simulation analysis of the impact of two kinds of ultra-high-speed PTFE/Al composite-structure reactive fragments on a shielded charge was carried out using the SPH algorithm. These were steel-coated PTFE/Al and steel-semi-coated PTFE/Al fragments, and they were compared with the impact of steel fragments. The results indicate that the threshold velocities of the impact initiation of the two composite-structure reactive fragments on the shielded charge were both 2.6 km/s, while the threshold velocity of the steel fragment was 2.7 km/s. Under the threshold velocity condition, the two composite-structure reactive fragments increase the time and intensity of the compressed shock wave pulse in the explosive due to the impact energy release effect of the reactive materials, causing the shielded charge to detonate under the continuous long-term pulse loads. However, the mechanism of the steel fragment on the shielded charge belongs to the shock-detonation transition. The research results can provide scientific references for the design of hypervelocity reactive fragments and the study of their damage mechanism.

Estimated pulse wave velocity and risk of new-onset heart failure.

As a potential surrogate of carotid-femoral pulse wave velocity, estimated pulse wave velocity (ePWV) has been confirmed to independently predict the cardiovascular events, but the association between ePWV and heart failure has not been well confirmed. Therefore, we performed this cohort study to evaluate the association between ePWV and risk of new-onset heart failure. A total of 98269 employees (mean age: 51.77±12.56years, male accounted for 79.9%) without prior heart failure who participated in the 2006-2007 health examination were selected as the observation cohort, with an average follow-up of 13.85±1.40years. Area under the receiver operator characteristic curve (AUC) of ePWV was calculated in prediction of heart failure. The adjusted Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals. The category-free net reclassification index (NRI) was calculated to evaluate the reclassification performance of cardiovascular risk models after adding ePWV. The AUC of ePWV was 0.74 in prediction of heart failure. After adjusting for the traditional cardiovascular risk factors except for age and blood pressure, the risk of new-onset heart failure increased by 35% [hazard ratio (HR): 1.35, 95% confidence interval (CI): 1.33-1.37] for each 1m/s increase in ePWV. Subgroup analysis showed that ePWV was significantly associated with incident heart failure regardless of THE presence (HR: 1.33, 95% CI: 1.31-1.36, P<0.01) or absence (HR: 1.59, 95% CI: 1.46-1.73, P<0.01) of cardiovascular risk factors, male (HR: 1.33, 95% CI: 1.31-1.36, P<0.01) or female (HR: 1.44, 95% CI: 1.38-1.51, P<0.01), young and middle-aged (<52years) (HR: 1.50, 95% CI: 1.41-1.58, P<0.01), or middle-aged and elderly (≥52years) (HR: 1.23, 95% CI: 1.21-1.26, P<0.01). The addition of ePWV to the traditional cardiovascular risk model including age and mean arterial pressure could significantly improve the reclassification ability by 31.1% (category-free NRI=0.311, P<0.01). ePWV was an independent predictor for new-onset heart failure.

Structural transition of a nanodroplet under an alternating electric field: Understandings and predictions from a dynamic density functional theory

Alternating current (AC) electric field is an efficient means in controlling the nanostructure of a material but the mechanism is not so clear in many systems. We introduced a dynamic density functional theory (DDFT) to mimic the formation and evolution of a nanodroplet/nanocluster under an AC electric field. The prediction from DDFT is qualitatively consistent with real-world experiments and molecular simulations. The influence from the AC electric field is summarized into a diagram and the transition line can be fitted into an empirical function. It seems the crystallization mechanism is different at high and low temperatures, in which the AC electric field is a favorable and unfavorable condition for crystallization, respectively. The crystallization can be divided into two steps which corresponds to the change of order parameter and free energy, respectively. Additionally, different AC waves results in similar nanostructures and the pulse wave has the highest order parameter.

Impact of respiratory cycle during mechanical ventilation on beat-to-beat right ventricle stroke volume estimation by pulmonary artery pulse wave analysis.

The same principle behind pulse wave analysis can be applied on the pulmonary artery (PA) pressure waveform to estimate right ventricle stroke volume (RVSV). However, the PA pressure waveform might be influenced by the direct transmission of the intrathoracic pressure changes throughout the respiratory cycle caused by mechanical ventilation (MV), potentially impacting the reliability of PA pulse wave analysis (PAPWA). We assessed a new method that minimizes the direct effect of the MV on continuous PA pressure measurements and enhances the reliability of PAPWA in tracking beat-to-beat RVSV. Continuous PA pressure and flow were simultaneously measured for 2-3min in 5 pigs using a high-fidelity micro-tip catheter and a transonic flow sensor around the PA trunk, both pre and post an experimental ARDS model. RVSV was estimated by PAPWA indexes such as pulse pressure (SVPP), systolic area (SVSystAUC) and standard deviation (SVSD) beat-to-beat from both corrected and non-corrected PA signals. The reference RVSV was derived from the PA flow signal (SVref). The reliability of PAPWA in tracking RVSV on a beat-to-beat basis was enhanced after accounting for the direct impact of intrathoracic pressure changes induced by MV throughout the respiratory cycle. This was evidenced by an increase in the correlation between SVref and RVSV estimated by PAPWA under healthy conditions: rho between SVref and non-corrected SVSD -0.111 (0.342), corrected SVSD 0.876 (0.130), non-corrected SVSystAUC 0.543 (0.141) and corrected SVSystAUC 0.923 (0.050). Following ARDS, correlations were SVref and non-corrected SVSD -0.033 (0.262), corrected SVSD 0.839 (0.077), non-corrected SVSystAUC 0.483 (0.114) and corrected SVSystAUC 0.928 (0.026). Correction also led to reduced limits of agreement between SVref and SVSD and SVSystAUC in the two evaluated conditions. In our experimental model, we confirmed that correcting for mechanical ventilation induced changes during the respiratory cycle improves the performance of PAPWA for beat-to-beat estimation of RVSV compared to uncorrected measurements. This was demonstrated by a better correlation and agreement between the actual SV and the obtained from PAPWA.

Correlation between estimated pulse wave velocity values from two equations in healthy and under cardiovascular risk populations.

Equations can calculate pulse wave velocity (ePWV) from blood pressure values (BP) and age. The ePWV predicts cardiovascular events beyond carotid-femoral PWV. We aimed to evaluate the correlation between four different equations to calculate ePWV. The ePWV was estimated utilizing mean BP (MBP) from office BP (MBPOBP) or 24-hour ambulatory BP (MBP24-hBP). We separated the whole sample into two groups: individuals with risk factors and healthy individuals. The e-PWV was calculated as follows: [Formula: see text] [Formula: see text] We calculated the concordance correlation coefficient (Pc) between e1-PWVOBP vs e2-PWVOBP, e1-PWV24-hBP vs e2-PWV24-hBP, and mean values of e1-PWVOBP, e2-PWVOBP, e1-PWV24-hBP and e2-PWV24-hBP. The multilevel regression model determined how much the ePWVs are influenced by age and MBP values. We analyzed data from 1541 individuals; 1374 ones with risk factors and 167 healthy ones. The values are presented for the entire sample, for risk-factor patients and for healthy individuals respectively. The correlation between e1-PWVOBP with e2-PWVOBP and e1-PWV24-hBP with e2-PWV24-hBP was almost perfect. The Pc for e1-PWVOBP vs e2-PWVOBP was 0.996 (0.995-0.996), 0.996 (0.995-0.996), and 0.994 (0.992-0.995); furthermore, it was 0.994 (0.993-0.995), 0.994 (0.994-0.995), 0.987 (0.983-0.990) to the e1-PWV24-hBP vs e2-PWV24-hBP. There were no significant differences between mean values (m/s) for e1-PWVOBP vs e2-PWVOBP 8.98±1.9 vs 8.97±1.8; p = 0.88, 9.14±1.8 vs 9.13±1.8; p = 0.88, and 7.57±1.3 vs 7.65±1.3; p = 0.5; mean values are also similar for e1-PWV24-hBP vs e2-PWV24-hBP, 8.36±1.7 vs 8.46±1.6; p = 0.09, 8.50±1.7 vs 8.58±1.7; p = 0.21 and 7.26±1.3 vs 7.39±1.2; p = 0.34. The multiple linear regression showed that age, MBP, and age2 predicted more than 99.5% of all four e-PWV. Our data presents a nearly perfect correlation between the values of two equations to calculate the estimated PWV, whether utilizing office or ambulatory blood pressure.