Changes In Velocity Research Articles

Prediction of evaporation temperature in air-water heat source heat pump based on artificial neural network

To improve the low-temperature heating stability and performance of the air-source heat pump (ASHP), a heat transfer model was established for an air-water heat source heat pump (A-WSHP) in this study. Key factors affecting A-WSHP evaporating temperature were analyzed through simulation. An artificial neural network (ANN) prediction model for refrigerant evaporating temperature was developed using fin pitch, air velocity, air temperature, spray flow rate, spray water temperature, and droplet diameter as inputs. In the winter climate of Xiangtan City, this model predicts the refrigerant evaporating temperature and regulates it by adjusting various input parameters. Results indicate that fin pitch and droplet size significantly impact the refrigerant evaporating temperature, more so than fin thickness. The air temperature (34.78 %) and spray water temperature (38.02 %) have the highest weights, while fin thickness has the least influence, with a weight of 0.75 %. The R2 value of the ANN refrigerant evaporating temperature prediction model is 0.974, indicating a good fit. By properly adjusting the heat pump fan and spray valve, changes in air velocity and spray flow rate can enhance the refrigerant evaporating temperature, leading to stable and efficient heat pump operation. This research not only provides a theoretical basis for the operational strategy of air-water heat pumps but also offers guidance for frost-free operation in low-temperature environments.

A settling velocity formula for irregular shaped microplastic fragments based on new shape factor: Influence of secondary motions

Microplastic (MP) fragments are prevalent in rivers and lakes and cause considerable pollution in natural water environments. Determining the settling velocity of microplastic fragments is crucial for predicting their migration and fate in aquatic systems. Predicting the settling velocity of MP fragments is challenging because of their complex and variable geometries and the uncertainties associated with secondary motions. To better understand the secondary motions of irregular MP fragments, a numerical model was developed to study the entire settling process, and an experiment was conducted to validate the numerical model. The model results showed the temporal changes in the settling velocity and orientation of MP fragments during the settling process. The MP fragments were classified according to their shape factors into fragments undergoing stable, transitional, and oscillating settling on the basis of velocity fluctuations caused by secondary motions. To describe the shape of irregular MP fragments appropriately, a new irregular shape factor (ISF) was derived by performing a theoretical analysis of forces and demonstrated to be more suitable than the Corey shape factor (CSF) for irregular MP fragments exhibiting considerable secondary motions. The settling velocity data were fitted to obtain an explicit settling velocity formula that includes the ISF for irregular MP fragments. Compared with machine learning methods and existing formulas, the proposed formula provides more accurate predictions of the settling velocity for irregular MP fragments.

Fluid effect on elastic properties of carbonate and implication for CO2 geological sequestration monitoring

Laboratory measurement of the elastic properties of carbonates saturated with different fluids is crucial for characterizing reservoirs and monitoring CO2 sequestration. However, it is challenging to distinguish the effects of different fluids. We measured eight carbonate samples under varying pressure and fluids saturation conditions, and conducted quantitative analysis. The measurements showed that water saturation can increase P-wave velocity (Vp), while oil and CO2 saturation may lead to an increase, decrease or no change in Vp. Meanwhile, all fluids saturation reduces the S-wave velocity (Vs). The velocities of dolomite samples are higher and less pressure-sensitive than that of limestone samples. Four attributes are adopted to distinguish the fluids effect, including elastic moduli, impedance, Vp/Vs ratio, and a newly designed fluid discrimination factor F, which is proposed by multiplying P-wave modulus and square value of density change. Among the attributes, the F factor performed the best as it achieved evident and consistent results for all the samples. Rock physics models were used to simulate the elastic behaviors with the differential effective medium model predicting Vs the best. The Gassmann’s equation correctly indicated the positive or negative changes of rock velocity after fluid saturation even though its prediction did not exactly match the data. This study highlights the impact of various pore fluids on the carbonate elastic properties through laboratory measurement and theoretical modeling, and introduces a novel fluid identification factor, providing insights for reservoir seismic characterization and CO2 sequestration monitoring.

Cerebral vasomotor reactivity to carbon dioxide using the rebreathe technique: assessment of within-day and between-day repeatability.

The cerebral vasodilator response to increased arterial carbon dioxide (CO2) concentration, termed cerebral vasomotor reactivity (CVMR), is used to assess cerebral vascular function. We sought to assess the within-day and between-day repeatability of CVMR to rebreathing-induced hypercapnia. Twelve healthy adults performed a within-day short interval protocol (17 ± 2 min between trials), ten performed a within-day long interval protocol (145 ± 16 min between trials), and seventeen performed a between-day protocol (5 ± 2 days between visits). Repeatability of the slope of the percent change in middle cerebral artery mean blood velocity (%MCAvmean) and cerebral vascular conductance index (%CVCi), to the change in partial pressure of end-tidal CO2 ([Formula: see text]) between the two trials/days was assessed. Within-day short interval, %MCAvmean slope demonstrated fair to excellent repeatability (intraclass correlation, ICC = 0.92 [95% confidence interval 0.72-0.98]; P < 0.001) while %CVCi slope showed more variability (ICC = 0.84 [0.47-0.95]; P = 0.002]). Within-day long interval, %MCAvmean (ICC = 0.95 [0.80-0.99]) and %CVCi (ICC = 0.94 [0.71-0.99]) slopes showed good to excellent and fair to excellent repeatability respectively (P < 0.001 for both). For between-day trials, better repeatability was observed for %CVCi (ICC = 0.85 [0.57-0.95]; P < 0.001) compared with %MCAvmean (ICC = 0.76 [0.33-0.91]; P = 0.004) slope. These findings indicate repeatable within- and between-day CVMR responses to rebreathe-induced hypercapnia. However, a longer interval may be better for within-day repeat trials, particularly for CVCi measures.NEW & NOTEWORTHY The cerebral vasodilator response to increases in arterial carbon dioxide concentration, termed cerebral vasomotor reactivity, provides an index of cerebral vascular function/health. Reduced responses are present in populations with elevated cerebral vascular and neurocognitive disease risk/overt disease. Cerebral vasomotor reactivity is often assessed during rebreathing-induced hypercapnia. This study determined that the day-to-day and between-day variability in this response is repeatable, thereby providing important methodological information to the scientific community.

Short-Term Multicomponent Exercise Impact on Muscle Function and Structure in Hospitalized Older at Risk of Acute Sarcopenia.

Hospitalization exacerbates sarcopenia and physical dysfunction in older adults. Whether tailored inpatient exercise prevents acute sarcopenia is unknown. This study aimed to examine the effect of a multicomponent exercise programme on muscle and physical function in hospitalized older adults. We hypothesized that participation in a brief tailored exercise regimen (i.e., 3-5 days) would attenuate muscle function and structure changes compared with usual hospital care alone. This randomized clinical trial with blinded outcome assessment was conducted from May 2018 to April 2021 at Hospital Universitario de Navarra, Spain. Participants were 130 patients aged 75 years and older admitted to an acute care geriatric unit. Patients were randomized to a tailored 3- to 5-day exercise programme (n = 64) or usual hospital care (control, n = 66) consisting of physical therapy if needed. The coprimary endpoints were between-group differences in changes in short physical performance battery (SPPB) score and usual gait velocity from hospital admission to discharge. Secondary endpoints included changes in rectus femoris echo intensity, cross-sectional area, thickness and subcutaneous and intramuscular fat by ultrasound. Among 130 randomized patients (mean [SD] age, 87.7 [4.6] years; 57 [44%] women), the exercise group increased their mean SPPB score by 0.98 points (95% CI, 0.28-1.69 points) and gait velocity by 0.09 m/s (95% CI, 0.03-0.15 m/s) more than controls (both p < 0.01). No between-group differences were observed in any ultrasound muscle outcomes. There were no study-related adverse events. Three to 5 days of tailored multicomponent exercise provided functional benefits but did not alter muscle or fat architecture compared with usual hospital care alone among vulnerable older patients. Brief exercise may help prevent acute sarcopenia during hospitalization. ClinicalTrials.gov identifier: NCT04600453.

Regional Blood Flow Spectral Parameters as Predictors of Epidural-Related Maternal Fever: A Prospective Observational Study

Background: Epidural-related maternal fever (ERMF) is a common phenomenon that appears to be unique to laboring women and presents diagnostic and therapeutic dilemmas for anesthesiologists. It is crucial to identify and predict the occurrence of ERMF at an early stage to improve the outcomes for mothers and infants. This study evaluated the degree of sympathetic blockade induced by epidural labor analgesia (ELA) by quantifying blood flow spectral parameters using Pulsed-wave Doppler (PWD). The aim was to determine the predictive value of these parameters for the onset of ERMF. Methods: A total of 103 women who had vaginal deliveries with ELA were recruited into the study. PWD ultrasound was used to measure peak systolic velocity (PSV, cm/s) and end-diastolic velocity (EDV, cm/s) in the anterior and posterior tibial arteries. Measurements were taken 1 minute before induction of analgesia and at 5-minute intervals for the subsequent 30 minutes. The change of PSV (ΔPSV) and EDV (ΔEDV) at 30 minutes relative to baseline after induction of analgesia was calculated. Participants were categorized into two groups based on their body temperature during labor and delivery: febrile and afebrile. Generalized estimating equations were used to assess differences both between and within groups across multiple time points. The correlation between two variables was analyzed using Spearman's rank correlation coefficient. Receiver operating characteristic (ROC) curves were plotted to ascertain the cut-off values of lower extremity arterial ultrasound flow spectral parameters for predicting ERMF. Results: Of the 103 study participants, 73 were ultimately included for analysis. Thirteen participants (17.8%) in the study developed ERMF. PSV was significantly higher in the febrile group than the non-febrile group at 10 min after ELA (p &lt; 0.05). In contrast, EDV showed a significant difference between the two groups at 15 min after ELA (p &lt; 0.01). Based on linear correlation analysis, there was a positive correlation between PSV and EDV at 30 minutes after analgesia induction and the peak labor temperature (p &lt; 0.05). ROC curve analysis identified a cut-off value of 43.35 and an area under the curve (AUC) of 0.701 for ΔPSV in the anterior tibial artery region (95% confidence interval (CI) 0.525 to 0.878, p = 0.025) and a cut-off value of 29.94 and an AUC of 0.733 for ΔEDV (95% CI 0.590 to 0.877, p = 0.001). The cut-off value for ΔPSV in the region of the posterior tibial artery was 39.96 with an AUC of 0.687 (95% CI 0.514 to 0.860, p = 0.034), and the cut-off value for ΔEDV was 33.10 with an AUC of 0.713 (95% CI 0.558 to 0.869, p = 0.007). Conclusions: Regional blood flow spectral parameters after epidural analgesia induction can predict the occurrence of ERMF by indirectly reflecting the degree of sympathetic activity inhibition. Specifically, the amount of change in peak systolic velocity and end-diastolic velocity relative to baseline parameters 30 min after ELA induction was the most predictive. Clinical Trial Registration: The study has been registered in the Chinese Clinical Trial Registry https://www.chictr.org.cn/ (reference number: ChiCTR2400080507, 31/01/2024).

Synchronous measurement of wind pressure and flow field in wind tunnel: device, method and application

Accurate assessment of the relationship between flow field and surface wind pressure distribution around buildings in wind tunnel tests is crucial for understanding the interaction mechanism between wind and buildings. Despite notable technological advancements in dynamic pressure measurement and flow visualization, the acquirement of synchronous data on flow and wind pressure around buildings still faces challenges in terms of accuracy, cost, and operational complexity. Given this, a frame synchronization technique has been developed to collect flow field and wind pressure data based on particle image velocimetry and Scanivalve dynamic pressure measurement. Meanwhile, this study established a more precise correction method for the distortion effect of the synchronously measured wind pressure signal. Furthermore, the paper demonstrates the feasibility of synchronously measuring the flow field and the corrected wind pressure in time through the flow around triangular prism test. Experimental results indicate that the corrected wind pressure distribution on triangular prism surface is consistent with the temporal variations in instantaneous flow velocity and vorticity change, thereby verifying the reliability of the synchronous test system.

Seasonal Variability of Ice Motion for Hubbard and Valerie Glaciers, Alaska

Hubbard Glacier is a large fast-flowing tidewater-terminating glacier in the St. Elias Mountains and is connected at its terminus to Valerie Glacier. Although Hubbard Glacier has been shown to experience large intra-annual velocity changes and a long-term deceleration, previous seasonality studies have had limited timescale without a dense record of motion. Valerie Glacier’s variability has also been understudied, with only one study reporting its seasonal behaviour. The goal of this study was to combine ITS_LIVE, RADARSAT-2, RADARSAT Constellation Mission, and TerraSAR-X/TanDEM-X derived velocity data to create the densest record of motion ever constructed for Hubbard and Valerie glaciers from July 2013-April 2022 in order to explore seasonal velocity variability of both glaciers. Air temperature (NCEP-NCAR Reanalysis) was used to estimate surface melt on the glaciers, which was explored as a potential driver for seasonal velocity changes. Valerie Glacier had a seasonal pattern of fast flow in May, with minimum flow between August-November before accelerating again. Hubbard Glacier displayed a unique seasonal pattern that has not been previously observed on this glacier, with two periods of fast motion: one in May and one in December-February. It is inferred that the spring peaks and late summer/fall minimums on both glaciers are due to meltwater reaching the glacier bed and influencing the subglacial hydrology. The cause of the winter peak and slight velocity drop before the spring peak on Hubbard Glacier has not been determined and should be a topic for future studies, although it is hypothesized to influenced by its geometry.

Spatiotemporal statistical features of velocity responses to traffic congestions in a local motorway network

Abstract The causal connection between congestions and velocity changes at different locations induces various statistical features, which we identify and measure in detail. We carry out an empirical analysis of large-scale traffic data on a local motorway network around the Breitscheid intersection in the North Rhine-Westphalia, Germany. We put forward a response function which measures the velocity change at a certain location versus time conditioned on a congestion at another location. We use a novel definition of the corresponding congestion indicator to ensure causality. We find that the response of velocities to the congestion exhibits phase changes in time. A negative response at smaller time lags transforms into positive one at larger time lags, implying a certain traffic mechanism. The response decays as a power law with the distance. We also identify a scaling property leading to a collapse of the response functions on one curve.

Development of a Mathematical Model of a Highly Maneuverable Robot for Simulation of Robots with Different Types of Designs

The article presents the results of developing a mathematical model and simulation modeling of a three-wheeled highly maneuverable mobile robot. A mathematical model of the robot in the state space has been developed. The possibility of using this robot with rotary modules for analyzing and testing control algorithms for robots of various designs has been considered. The relevance of the study is justified by the high costs of creating physical models of robots for experimental verification of control algorithms. The proposed three-wheeled mobile robot with rotary modules, where each wheel is simultaneously both a driving and a steering wheel, allows reducing these costs, while maintaining the ability to simulate part of the real operating conditions. Simplified diagrams of the robot are given, the main parameters and equations characterizing the change in linear and angular velocity are described. Particular attention is paid to modeling various types of robot drives: automotive type and with a differential drive. In the discrete state space, equations describing the dynamics of the robot were presented, which allows them to be used in software products for modeling. The results of simulation modeling obtained in the SimInTech software environment confirm the effectiveness of the proposed model. The analysis of the obtained results showed that the use of a three-wheeled robot with rotary modules allows successfully simulating the behavior of robots with other types of drives and creating conditions close to real ones for testing control algorithms. The proposed model can be used to improve the quality of design and testing of control algorithms in robotics, while reducing the costs of creating physical models of robots, as well as in the educational process.

CFD modeling of DME synthesis based on methanol dehydration process by an adiabatic reactor: Characterization

Today, Dimethyl ether (DME) can be used as a fuel in various applications, including as a substitute for diesel fuel. Despite its advantages, there are some challenges associated with DME as a fuel. One of the main challenges is the limited availability of DME refueling stations and the need for dedicated storage facilities due to their different properties compared to traditional fuels. DME shows promise as a clean-burning alternative fuel with the potential to reduce emissions and dependence on fossil fuels, especially in the transportation and power generation sectors. Ongoing research and development efforts are focused on improving production methods, expanding infrastructure, and exploring new applications for DME as a fuel. DME is a colorless gas that can be used as a fuel or as a precursor for the production of other chemicals. The most common method for DME synthesis involves the dehydration of methanol. Methanol is first converted to dimethyl ether by removing a molecule of water. This reaction is typically catalyzed by acidic materials such as alumina or zeolites. In this work, to study the physical properties of the methanol dehydration reaction, CFD modeling of the adiabatic reactor has been accomplished. The researchers showed that the use of an alumina catalyst, which has selective mechanical properties and unique surface properties, is a suitable choice as a catalyst for DME synthesis. The results of this study indicate that laboratory data such as pressure, energy, and velocity in the adiabatic reactor satisfy the reaction conditions well. Also, temperature profile diagrams with changes in temperature, pressure, and velocity show that the reaction of methanol dehydration is strongly dependent on environmental factors and presents different results under the influence of other conditions.

Impact of Acoustic and Optical Phonons on the Anisotropic Heat Conduction in Novel C-Based Superlattices.

C-based XC binary materials and their (XC)m/(YC)n (X, Y ≡ Si, Ge and Sn) superlattices (SLs) have recently gained considerable interest as valuable alternatives to Si for designing and/or exploiting nanostructured electronic devices (NEDs) in the growing high-power application needs. In commercial NEDs, heat dissipation and thermal management have been and still are crucial issues. The concept of phonon engineering is important for manipulating thermal transport in low-dimensional heterostructures to study their lattice dynamical features. By adopting a realistic rigid-ion-model, we reported results of phonon dispersions ωjSLk→ of novel short-period XCm/(YC)n001 SLs, for m, n = 2, 3, 4 by varying phonon wavevectors k→SL along the growth k|| ([001]), and in-plane k⟂ ([100], [010]) directions. The SL phonon dispersions displayed flattening of modes, especially at high-symmetry critical points Γ, Z and M. Miniband formation and anti-crossings in ωjSLk→ lead to the reduction in phonon conductivity κz along the growth direction by an order of magnitude relative to the bulk materials. Due to zone-folding effects, the in-plane phonons in SLs exhibited a strong mixture of XC-like and YC-like low-energy ωTA, ωLA modes with the emergence of stop bands at certain k→SL. For thermal transport applications, the results demonstrate modifications in thermal conductivities via changes in group velocities, specific heat, and density of states.

Thermal energy and thermo-economic analysis of PCM-TES for space heating based on low-temperature waste heat: An experimental and numerical study

Great potential for using low-temperature waste heat for energy savings has been revealed in recent years. In this study, a novel PCM-TES unit integrated into a fresh air system was proposed to effectively utilize low-temperature waste heat to address shortcomings of preheating outdoor air for space heating. An experimental setup was built to investigate the heat storage and release performance of proposed unit. Well-validated CFD simulations further parametrically studied PCM thermal characteristics to HTF’s velocity and temperature changes. Energy and thermo-economic analyses were employed to evaluate unit potentials across three Chinese cities with different climate zones. The results showed that charging process was completed in 142–253 min at water temperatures of 55–60 °C; discharging process efficiency increased by 36.10% as the air velocity increased from 2 to 4 m/s. EPI revealed that, theoretically, the system could handle up to 28.2% of the heating demand. Energy and economic analysis indicated the system’s significant potential in colder climates, with Harbin achieving average energy savings of 7.93% and 13.48% over Qingdao and Chongqing, respectively, and cost savings up to 67.65% and 229.61% compared to those cities. This study is expected to shed light on the utilization of low-temperature waste sources for indoor space heating.

Monitoring seismic velocity changes at Campi Flegrei (Italy) using seismic noise interferometry

Campi Flegrei is a volcanic field located west of Naples (Italy) in a densely populated area. Since 2005, its ground has been rising steadily due to the accumulation of fluids at shallow depths. The inflation of volcanic edifices is a possible precursor of an impending eruption. The uplift is accompanied by increasing seismic activity. This raises concerns about the possibility that the volcano may be on the verge of an eruption. To track the fluid movement, it is possible to monitor subtle changes of velocities of seismic waves by exploring ambient seismic noise. By examining different frequency bands, we can observe velocity changes at different depths. We interpret these changes as a monitoring of depth-dependent deformation in addition to the standard monitoring of surface deformation. We observe a velocity decrease in the long-term trend, presumably due to the extension of the hydrothermal system at shallow depths. To explain the long-term changes, we model a spherical pressure source to simulate volumetric strain changes induced by recent fluid activity. The model explains both, surface and subsurface deformation which leads to the opening of microcracks and pores, resulting in the observed velocity decrease. The short-term velocity changes are mainly driven by temperature or groundwater level changes. Once velocity changes are corrected for seasonal effects, remaining short term velocity changes can be associated with volcanic activity and earthquake swarms.

Quantifying Normal Diaphragmatic Motion and Shape and their Developmental Changes via Dynamic MRI

BackgroundThe diaphragm is a critical structure in respiratory function, yet in-vivo quantitative description of its motion available in the literature is limited. Research QuestionHow to quantitatively describe regional hemi-diaphragmatic motion and curvature via free-breathing dynamic magnetic resonance imaging (dMRI)? Study Design and MethodsIn this prospective cohort study we gathered dMRI images of 177 normal children and young adults and segmented hemi-diaphragm domes in end-inspiration and end-expiration phases of the constructed 4D image. We selected 25 points uniformly located on each 3D hemi-diaphragm surface. Based on the motion and local shape of hemi-diaphragm at these points, we computed the velocities and sagittal and coronal curvatures in 13 regions on each hemi-diaphragm surface and analyzed the change in these properties with age and sex. ResultsOur cohort consisted of 94 Females, 6-20 years (12.09+3.73), and 83 Males, 6-20 years (11.88+3.57). We observed velocity range: ∼2mm/s to ∼13mm/s; Curvature range – Sagittal: ∼3m-1 to ∼27m-1; Coronal: ∼6m-1 to ∼20m-1. There was no significant difference in velocity between sexes, although the pattern of change in velocity with age was different for the two groups. Strong correlations in velocity were observed between homologous regions of right and left hemi-diaphragms. There was no significant difference in curvatures between sexes or change in curvatures with age. InterpretationRegional motion/curvature of the 3D diaphragmatic surface can be estimated using free-breathing dynamic MRI. Our analysis sheds light on here-to-fore unknown matters such as how the pediatric 3D hemi-diaphragm motion/shape varies regionally, between right and left hemi-diaphragms, between sexes, and with age.

Automobile Intelligent Vehicle-machine and Human-computer Interaction System based on Big Data

This paper measures the accelerator, brake pedal, clutch, transmission device and steering wheel under different driving conditions in real-time and accurately on the simulation experiment platform. The goal is to conduct human-machine-road system interaction in a virtual simulation of human-vehicle-road systems. Fitting test data establishes the mathematical model of traffic control parameters. In terms of hardware, the distributed architecture of upper and lower computers is utilized. The system communicates point-to-point with the host computer through the RS-232 serial port. The system adopts multi-thread technology and serial communication technology. The simulation system of driving operation is designed with the visual central controller. The system takes 89S52 as the core. The slave program is written in C language. Then, the system establishes a multi-target coordinated obstacle avoidance method based on a multi-sensor information vehicle cooperation collision avoidance method. The multi-vehicle cooperation obstacle avoidance problem is transformed into an optimal control problem under multiple constraints. Simulation analysis shows that the velocity and displacement obtained by the multi-robot collaborative collision avoidance method are in good agreement with the measured values. Compared with the time series algorithm, the output accuracy of the proposed collaborative collision avoidance algorithm is significantly reduced, and the changes in velocity and displacement in the time domain are more stable.

137 - WSS and velocity changes of common iliac arteries in patients with abdominal aortic aneurysm: assessment using 4D flow MRI

137 - WSS and velocity changes of common iliac arteries in patients with abdominal aortic aneurysm: assessment using 4D flow MRI

Time-Lapse Shear-Wave Velocity Changes Corresponding to Stages of Soil Arching Using a Trapdoor and the Multichannel Analysis of Surface Waves

Time-Lapse Shear-Wave Velocity Changes Corresponding to Stages of Soil Arching Using a Trapdoor and the Multichannel Analysis of Surface Waves

Utility of doppler ultrasound in early-onset neonatal sepsis: A case-control study.

Early-onset sepsis is one of the leading causes of neonatal morbidity and mortality worldwide and timely diagnosis is, therefore, of paramount importance. As there is a lack of literature regarding early alteration of the cerebral blood flow (CBF) in neonatal sepsis, our study aimed to appraise changes in the CBF velocities and Doppler indices in neonates with early-onset neonatal sepsis (EONS) and to assess its diagnostic accuracy. A total of 99 neonates were recruited in the study; 56 neonates with EONS, and the age-matched 43 neonates without any manifestations of sepsis. A Transcranial Doppler examination and cerebral hemodynamics were assessed in neonates during the first seventy-two hours of life. Doppler indices and CBFV were measured in the anterior cerebral artery (ACA), and middle cerebral artery (MCA), of either side. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. A significantly lower resistance in Resistivity (RI) and Pulsatility (PI) indices, a significant high end-diastolic velocity (EDV), and relatively higher peak systolic velocity (PSV) in both ACA and MCA have been documented within 72 hours of birth in neonates with EONS compared to the control group of neonates without sepsis. Our Study revealed that assessment of CBF at early hours of birth by Transcranial Doppler examination showed alteration in cerebral hemodynamics in neonates with EONS with an increase in the CBF and a decrease in the resistance. It can be adopted as a bedside, noninvasive tool with immediate diagnostic value.

Impact of three-month treatment with pitavastatin on arterial stiffness in patients with hypercholesterolemia: a prospective observational study

ObjectiveAlthough several studies have highlighted the benefits of statins in improving arterial stiffness, there is limited research on whether pitavastatin, a more recently developed statin, has similar effects. This study aimed to investigate the impact of pitavastatin on arterial stiffness in patients with hypercholesterolemia. MethodsThis prospective study enrolled 115 patients with hypercholesterolemia (mean age, 59 years; 22% female) who had not previously been treated with statins. Participants underwent lifestyle interventions followed by administration of pitavastatin (2 or 4 mg daily) if target low-density lipoprotein (LDL) cholesterol levels were not achieved. The primary outcome measured was the change in brachial-ankle pulse wave velocity (baPWV) from baseline after three months of treatment. ResultsPitavastatin treatment significantly reduced LDL cholesterol by 41.1% (from 158 ± 28 to 93.0 ± 29.6 mg/dL; P < 0.001). Additionally, systolic blood pressure (SBP) decreased significantly from 130 ± 14 to 126 ± 14 mmHg (P < 0.001), representing a 2.9% reduction, and baPWV decreased significantly from 1522 ± 325 to 1407 ± 289 cm/s (P < 0.001), a 7.6% reduction. There was a significant correlation between changes in SBP and changes in baPWV (r = 0.565; P < 0.001). Even after adjusting for changes in SBP, the reduction in baPWV induced by pitavastatin remained statistically significant (P < 0.001). ConclusionA three-month treatment with pitavastatin effectively reduced arterial stiffness in patients with hypercholesterolemia, alongside significant improvements in lipid profiles and blood pressure reductions. These findings support the use of pitavastatin for managing key cardiovascular risk factors.