Average Pressure Research Articles

Thermal-hydraulic performance of modified Schwartz-Diamond solid-networks triply periodic minimal surface structures

The triply periodic minimal surface (TPMS) structures are widely used as disturbance core structure in high performance heat exchangers. In this paper, four modified Schwartz-Diamond solid-networks (SD-solid) TPMS structures, one structure compressed along the flow direction (β = 2), and three structures compressed along the spanwise direction (α = 2, α = 3, and α = 4) are designed. Flow and heat transfer processes in the structures are studied with computational fluid dynamics (CFD) and experimental method. The performance enhancement criterion (PEC) is employed to evaluate the overall heat transfer performance. As the results of simulation, the overall heat transfer coefficient (hoverall) of α = 2, α = 3, and α = 4 is 10.04 %, 34.34 %, and 62.03 % higher than that of SD-solid respectively. The PEC of α = 2, α = 3, and α = 4 structures is 27.35 %, 34.17 %, and 34.95 % higher than that of the original SD-solid structure, respectively. Two samples of them (β = 2 and α = 2) are fabricated using additive manufacturing and their thermal–hydraulic performance is experimented on a flow and heat transfer experimental platform. Comparing the experimental results of the hoverall, the β = 2 structure is 68.5 % higher and the α = 2 structure is 23.06 % higher than the original SD-solid structure. However, for the average pressure drop, the β = 2 structure is 448.5 % higher and the α = 2 structure is 66.77 % lower than the original SD-solid structure. It is proved that the modified SD-solid structure compressed along the spanwise direction has the performance of enhancing heat transfer and reducing the pressure drop.

Shape optimization of annular transonic thrust nozzles via genetic algorithm and adjoint method

In this research, the idea of combining the genetic algorithm and adjoint method was proposed to leverage the benefits of both approaches to improve the accuracy of thrust nozzle shape optimization. Although the genetic algorithm can search the entire design space to approach the global optimum, its computational cost increases considerably with the number of design variables. Meanwhile, the adjoint method is unaffected by the design variables, but it cannot achieve the global optimum directly and relies on the initial guess geometry. To address these challenges, a genetic algorithm was initially employed to approximate the global optimal geometry of a thrust nozzle with a conical center body parameterized by a Bezier curve. A MATLAB code integrated the geometry parameterization, genetic algorithm, and Fluent R2 2021 flow solver. The resulting geometry was then considered as the initial guess for the adjoint method, which accurately achieved the final optimal geometry with increased control points. The genetic algorithm aimed to maximize the thrust coefficient as the objective function, while the adjoint solver aimed to minimize the axial velocity variance at the nozzle outlet as the cost function. Three distinct constraints were incorporated in the optimization process, and the influence of the center body shape on the results was thoroughly examined to consider all possible geometries throughout the optimization procedure. The findings revealed that the conical center body effectively adjusted the flow angle at the exit, significantly affecting the thrust force. Both optimization steps reduced the average velocity and increased the average pressure at the nozzle exit, enhanced the mass flow rate, and finally increased the thrust force. The genetic algorithm and adjoint method contributed to 3 % and 0.6 % increases, respectively, in the thrust force, resulting in a thrust coefficient of 96.15 % for the final optimized nozzle.

Reservoir Quality Under the Control of Gravity Flows in the C7 Member of Yanchang Formation in the Jinghe Oilfield, Ordos Basin, China

The late Triassic sandstone reservoir in the C7 member of the Jinghe oilfield southern Ordos basin is a typical deep-water gravity flow tight oil reservoir. Sedimentary microfacies, physical properties, and petrographic analysis were being examined for quality determination. Pore structure and physical properties data together combined with, thin sections, and scanning electron microscope and core images were used to identify factors controlling reservoir physical properties. The depositional system under debates of different gravity flows including debris flow, seismite slumping, and turbidity flows. Among which sandy debris flow facies shows a better distribution of porosity and permeability followed by seismite-slump, where turbidity facies are the poorest. The petrophysical analysis shows that the study oil interval is a typical tight sandstone reservoir with an average porosity of 9% and permeability average being 0.025mD. The rock classification criteria of the C7 sandstone reveal the sub-categories of lithic feldspar sandstone and feldspar lithic sandstone. Average quartz sandstone contents of 48.25%, average feldspar sandstone content being 25%, and lithic fragments content of 29%. The formation lithology comprises mostly fine-grained sandstone and small pore size, which disclose that the porosity-permeability distribution increases proportional to the average and median pore throat radius, and decreases with average and median pressure. The microfacies distribution shows that the depositional facies controlled physical properties. The sandstone primary pores are affected by the mineral composition of quartz, feldspar, illite, smectite, kaolinite, calcite, and dolomite. Features such as dissolved pores and intergranular pore filling by feldspar, silky-like aggregates of illite-smectite intergranular pore filling and most diagenetic minerals influenced the sandstone pores beside the compaction.

Design, assembly and testing of an upgraded aeroacoustics wind tunnel facility

The Aeroacoustics Laboratory in the Department of Aerospace Engineering at Penn State currently serves several areas of experimental research. Most notable in the laboratory is the Anechoic Chamber of which the Aeroacoustics Wind Tunnel is an integral part. In recent years the dominant areas of research have included model aircraft exhaust jets and model rotors for helicopter applications involving detailed noise experiments. In the jet noise area, the applications have included aircraft in both flyover and take-off configurations. In the flyover application the air flow surrounding the exhaust jet has a significant effect on the radiated noise and must be simulated to produce experimental results that will be most useful in preliminary design of noise suppression applications. The Aeroacoustics Wind Tunnel at Penn State serves the purpose for this simulation. During aircraft take-off, the aircraft airspeed is in a range exceeding 250 ft per second, or Mach number of over M = 0.22. In the years preceding 2022, the velocity of the free jet flow of the Penn State facility was limited to less than 200 ft/sec. This paper reports on a project to design upgrades to the existing wind tunnel to improve the test section flow velocity to values closer to the 250 ft/sec target. The approach began with a preliminary design of the return flow ducting to convert the open jet, open return wind tunnel to a closed return tunnel. The concept is to make use of the flow energy in the exhaust of the tunnel to boost the input energy to the inlet fan that drives the flow to the test section. An integral part of the preliminary design involved making use of an upgraded flow analysis computer code to predict the gain in test section velocity of the new facility. For the available horsepower of two fans in the facility, the configurations of the existing and upgraded wind tunnel were entered into this analysis code based on a quasi-one-dimensional formulation. The code included empirical data formulated to include the various shapes of the components of the tunnels. The relative flow velocities in each section used simple incompressible continuity to calculate all velocities in the component sections. The average dynamic pressure in each section is calculated from the flow (constant) density and the velocity squared. Each section had a non-dimensional pressure loss parameter calculated from empirical data (from the relevant literature). The basic code (using the Excel algorithms) was based on a predictor-corrector concept in which the calculation was initialized with the estimated velocity and pressure of the flow at the entrance to the test section. The loss in each following section is estimated to determine the loss in the total pressure and the cumulated loss compared to the gains made at the two fans in the circuit. The initial guess is adjusted based on the total pressure value at the end of the circuit. During the related experiments, measurements of the total and dynamic pressure were performed at several joints between sections and compared to the values predicted in the analysis code. Various settings of the horsepower of the drive fans were used and the results were compared to flow measurements for the tunnel configurations (predominantly for the open return and closed return tunnel setups available before and after the upgrade project.) Results of the analysis and experiments are presented and analyzed together with the remaining activities planned for the coming months.

Changes in the state of matter of KCIO4 to improve thermal and combustion properties of Al/MoO3 nanothermite

To improve the thermal and combustion properties of nanothermites, a design theory of changing the state of matter and structural state of the reactants during reaction was proposed. The Al/MoO3/KClO4 (Kp) nanothermite was prepared and the Al/MoO3 nanothermite was used as a control. SEM and XRD were used to characterize the nanothermites; DSC was used to test thermal properties; and constant volume and open combustion tests were performed to examine their combustion performance. Phase and morphology characterization of the combustion products were performed to reveal the mechanism of the aluminothermic reaction. The results show that the Al/MoO3/Kp nanothermite exhibited excellent thermal properties, with a total heat release of 1976 J·g− 1, increasing by approximately 33% of 1486 J·g− 1 of the Al/MoO3 nanothermite, and activation energy of 269.66 kJ·mol− 1, which demonstrated higher stability than the Al/MoO3 nanothermite (205.64 kJ·mol− 1). During the combustion test, the peak pressure of the Al/MoO3/Kp nanothermite was 0.751 MPa, and the average pressure rise rate was 25.03 MPa·s− 1, much higher than 0.188 MPa and 6.27 MPa·s− 1 of the Al/MoO3 nanothermite. The combustion products of Al/MoO3 nanothermite were Al2O3, MoO, and Mo, indicating insufficient combustion and incomplete reaction, whereas, the combustion products of Al/MoO3/Kp nanothermite were Al2O3, MoO, and KCl, indicating complete reaction. Their “coral-like” morphology was the effect of reactants solidifying after melting during the combustion process. The characterization of reactants and pressure test during combustion reveals the three stages of aluminothermic reaction in thermites. The excellent thermal and combustion performance of Al/MoO3/Kp nanothermite is attributed to the melt and decomposition of Kp into O2 in the third stage. This study provides new ideas and guidance for the design of high-performance nanothermites.

Clinical Effects of Sildenafil in the Treatment of Congenital Heart Disease with Pulmonary Hypertension

Objective: To analyze the improvement of mean pulmonary arterial pressure and oxygenation index as well as the therapeutic effect of sildenafil treatment in patients with congenital heart disease and pulmonary arterial hypertension. Methods: A total of 104 patients with congenital heart disease and pulmonary arterial hypertension were recruited from February 2023 to January 2024 and grouped into study and control groups using a randomized numerical table, with 52 patients in each group. The study group received sildenafil treatment, while the control group received conventional treatment. The therapeutic effects of both groups were analyzed and compared. Results: The study group had an average pulmonary arterial pressure of 26.23 ± 2.16 mmHg, an oxygenation index of 241.63 ± 4.86, and a total effective treatment rate of 98.08%, which was significantly better than the control group (P < 0.05). Conclusion: By implementing sildenafil treatment for patients with congenital heart disease and pulmonary hypertension, the mean pulmonary artery pressure and oxygenation index of the patients improved significantly, and the effective rate of treatment increased significantly.

“Advocates for Each Other”: The creation and evaluation of a pragmatic peer navigation program for black patients in primary care with uncontrolled hypertension

BackgroundBlack individuals in the U.S. and in our primary care clinic experience worse control of blood pressure compared to White individuals. ObjectiveTo address this inequity, our objectives were to (1) elicit from patients and community members their ideas for barriers and facilitators to blood pressure control; and (2) use their input to design and pilot a navigator program for Black patients in our clinic to improve blood pressure management. Patient involvementWe conducted three focus groups with 27 individuals and identified two main areas of need that informed the peer navigator program: (1) community-based services and (2) skill development for hypertension self-management. MethodsPeer navigators from the Black community called participants at least monthly for 6–12 months and connected them with medical and social services. Available blood pressure data was used as the primary outcome to measure change pre- to post-peer navigation program. ResultsAmong 499 eligible patients in the clinic, 53 (10.6%) enrolled in the peer navigation program. For those with baseline and follow-up blood pressure data, mean systolic blood pressure decreased from 155.9 to 142.4 mmHg after the program (change of −13.6, 95% CI −24.7 to −2.4) for the enrolled patients (N = 17) and from 139.1 to 137.1 mmHg (change of −2.5, −4.8 to 1.9) for unenrolled, comparison patients (N = 183). DiscussionThis community-informed peer navigation program to support Black patients with uncontrolled hypertension led to a 11.1 mmHg greater decrease in average systolic blood pressure for enrolled patients compared to the comparison group. However, the enrolled group started with a significantly higher systolic blood pressure at baseline with more room for improvement. While this study was conducted during the pandemic years, low uptake of this program needs to be addressed in expansion efforts. Practical valueClinic-based peer navigation for hypertension improved blood pressure control and was highly regarded by the subset of enrolled patients. Increasing uptake and sustainable funding for non-billable clinic roles remain areas of need. FundingGrant from the Pacific Hospital Preservation & Development Authority.

The Role of Blood Pressure Control in Prevention of Hematoma After Blepharoplasty.

Hematoma formation after blepharoplasty is serious and potentially vision-threatening, with hypertension being the primary risk factor. The aim of this paper is to assess perioperative blood pressure trends and rates of complication in patients undergoing a strict blood pressure protocol designed to keep perioperative systolic blood pressure below 120 mmHg. A retrospective chart review was performed of 32 patients undergoing face lift with conomitant blepharoplasty from January 2015 to July 2018. For each patient blood pressure readings obtained before, during, and after surgery were reviewed. Two-sample one-tail T-tests were performed, and p values less than 0.05 were considered statistically significant. The mean systolic blood pressure (SBP) for all patients was highest intraoperatively. Patients with known hypertension had higher mean SBPs than patients without hypertension across all phases of care, with a statistically significant difference in immediate preoperative SBP (p=0.05). Males had a higher average blood pressure immediately postoperatively (p=0.05). A previous diagnosis of hypertension in females was associated with a higher immediate preoperative SBP (p=0.07) as well as age over 65 (p=0.07). The overall rate of complications was 37.5%. No patients experienced hematoma. This study demonstrated that keeping blood pressure below 120 mmHg after surgery was an effective method of preventing hematoma after blepharoplasty, even in patients concurrently on anti-coagulative medications. Special attention to blood pressure control should be shown to patients with known risk factors such as a previous diagnosis of hypertension, male sex, or age greater than 65. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impact Of Global Warming on Tropical Cyclones in The Northwest Pacific Ocean

Tropical cyclones are meteorological phenomena that can affect mid to low latitudes around the world. This Paper systematically summarizes and reviews the main characteristics, potential influencing factors, and influencing mechanisms of tropical cyclones in Northwestern Pacific, and summarizes and analyzes their changing trends in the context of global change. Global warming will affect the generation and development of tropical cyclones from multiple dimensions, with the most intuitive being the surface temperature of seawater. Through the analysis of global surface temperature and tropical cyclones in the Northwest Pacific, it is shown that as global climate warms, the frequency of tropical cyclones in the Northwest Pacific decreases, the extreme central pressure decreases, and the extreme maximum central wind speed increases, there is no significant trend in the average minimum pressure and average maximum wind speed of tropical cyclones. In other words, the extreme intensity of tropical cyclones strengthens; In the 2010s, this relationship was particularly prominent.

Cross-dimensional multi-physics model and two-phase mass-transport enhancement for the hydrogen peroxide-based fuel cell

The direct liquid fuel cell utilizing hydrogen peroxide as an oxidant is considered to be the promising energy conversion technology, owing to its superior energy density and theoretical voltage. In the hydrogen peroxide-based fuel cells, the ever-changing two-phase mass transport and multi-component reaction processes resulting from the hydrogen peroxide self-decomposition exerts a pivotal influence on their performance. In this work, taken hydrogen peroxide self-decomposition into account, a cross-dimensional multi-physics model for the hydrogen peroxide-based fuel cell was proposed and developed to clarify the complex mechanisms of transports and reactions. In this ingeniously developed model, the multi-component reaction in the porous electrode is elucidated by a two-dimensional (2D) sub-model, the two-phase mass transport in the flow field is captured by a three-dimensional (3D) sub-model, and the one-dimensional (1D) correlation equation is served as a bridge between them. The uneven distribution of gas–liquid volume, velocity and current density and their relationships in fuel cell with serpentine flow field and dot matrix flow field were thus achieved. Furthermore, a novel gradient dot matrix flow field was developed to match the two-phase mass transport and multi-component reaction processes of hydrogen peroxide-based fuel cell. It is found that the continuously increasing pressure and velocity along flow path is balanced by the gradient-downsized ribs and the formation of large-volume oxygen bubbles is prevented by the gradient-densified ribs, achieving obviously uniformized current density distribution. Moreover, the gradient dot matrix flow field enables 54 % higher average hydrogen peroxide coverage contents (49 %) and 86 % lower average pressure drop (172 Pa) compared to the serpentine flow field, yielding 6.3 % higher peak power density (210 mW cm−2) and ultra-low extra pump power in fuel cell. This work will make contribution towards gaining profound insights into the intricate mechanisms underlying mass and charge transport, and offering invaluable guidance for the flow field design for the hydrogen peroxide-based fuel cells.

Effect of the early diastolic blood pressure response to the head-up tilt test on the recurrence of benign paroxysmal positional vertigo.

Otolith organ acts complementarily with the autonomic nervous system to maintain blood pressure. However, the effect of blood pressure variability in the autonomic nervous system on otolith organ has not yet been determined. This study aimed to verify the hypothesis that blood pressure variability in the autonomic nervous system affects the recurrence of benign paroxysmal positional vertigo (BPPV), which is the most common disease of the vestibular organs, by using the head-up tilt test (HUTT). This study included 432 patients diagnosed with idiopathic BPPV. The follow-up period for all patients was 12 months. Age, sex, hypertension, diabetes and recurrence were analyzed. The HUTT parameters were divided into a group of patients whose average diastolic blood pressure increased in the upright position compared to supine position during the HUTT (DBP1) and a group of patients whose average diastolic blood pressure decreased in the upright position compared to supine position during the HUTT (DBP2). Model selection, general loglinear analysis, and logit loglinear analysis were performed using a hierarchically progressing loglinear analysis. In summary, the group with increased average diastolic blood pressure (DBP1) showed a higher tendency for BPPV recurrence compared to the group with decreased diastolic blood pressure (DBP2) in the upright position during the HUTT, although the difference was not statistically significant (p = 0.080). However, in males, the DBP1 group demonstrated a significantly higher recurrence rate of BPPV than the DBP2 group during the HUTT (95% CI, -20.021 to -16.200; p < 0.001). It is presumed that poor autonomic nervous system response through vestibulosympathetic reflex maintains elevated diastolic blood pressure in the upright position during the HUTT. This variability is assumed to affect the recurrence of BPPV.

ANALYSIS OF CIRCADIAN RHYTHM AND DETECTION RATE OF EARLY EVENING ELEVATED BLOOD PRESSURE IN HYPERTENSIVE PATIENTS

Objective: The aim of the study is to investigate the circadian rhythm and detection rate of early evening elevated blood pressure (EEE) in treated and untreated hypertensive patients by ambulatory blood pressure monitoring. Design and method: From February 1, 2020 to February 28, 2023, the total of 1413 hypertensivs underwent ambulatory blood pressure monitoring in 13 medical institutions through the National 13th Five Year Plan Major Cooperation Group for Chronic Disease Prevention and Control (Research on the Application of Lifestyle and Nutritional Intervention Techniques and Strategies for Obesity and Hypertension, No. 2016YFC1300100). Among them, 1026 had taken antihypertensive drugs and 387 had not taken antihypertensive drugs. EEE is defined as average systolic blood pressure is higher or equal to 135mmHg or average diastolic blood pressure is higher or equal to 85mmHg from 6PM to 10PM. The definitions of dipper, non-dipper, super-dipper, and reverse-dipper blood pressure refer to the 2020 China Ambulatory Blood Pressure Monitoring Guidelines. Results: 1. The detection rate of EEE in treated hypertensive patients was 60.4% (620 patients), while the detection rate of EEE in untreated hypertensive patients was 70.5% (273 patients); 2. The detection rate of dipper type in treated hypertensive patients was 21.7% (223 patients), while the detection rate of dipper type in untreated hypertensive patients was 21.7% (84 patients); 3. The detection rate of non-dipper type in treated hypertensive patients was 51.4% (527 patients), while the detection rate of non-dipper type in untreated hypertensive patients was 53.5% (207 patients); 4. The detection rate of super-dipper type in treated hypertensive patients was 1.6% (16 patients), while the detection rate of super-dipper type in untreated hypertensive patients was 1.8% (7 patients); 5. The detection rate of reverse-dipper type in treated hypertensive patients was 25.3% (260 patients), while the detection rate of reverse-dipper type in untreated hypertensive patients was 23% (89 patients). Conclusions: The detection rate of EEE is significantly higher than that of traditional non-dipper, super-dipper, and reverse-dipper blood pressure; It is possible that EEE become a new target for antihypertensive treatment.

ANALYSIS OF DETECTION RATE OF EARLY EVENING ELEVATED BLOOD PRESSURE IN HYPERTENSIVE PATIENTS BY AMBULATORY BLOOD PRESSURE MONITORING

Objective: The aim of the study is to investigate the detection rate of early evening elevated blood pressure (EEE) in treated and untreated hypertensive patients by ambulatory blood pressure monitoring. Design and method: From February 1, 2020 to February 28, 2023, the total of 1413 hypertensive patients underwent ambulatory blood pressure monitoring in 13 medical institutions through the National 13th Five Year Plan Major Cooperation Group for Chronic Disease Prevention and Control (Research on the Application of Lifestyle and Nutritional Intervention Techniques and Strategies for Obesity and Hypertension, No. 2016YFC1300100). Among them, 1026 patients had taken antihypertensive drugs and 387 patients had not taken antihypertensive drugs. EEE is defined as average systolic blood pressure is higher or equal to 135mmHg or average diastolic blood pressure is higher or equal to 85mmHg from 6PM to 10PM. Results: 1. The detection rate of EEE in treated hypertensive patients was 60.4% (620 patients), while the detection rate of EEE in untreated hypertensive patients was 70.5% (273 patients); 2. The detection rate of daytime hypertension in treated hypertensive patients was 55.8% (573 patients), while the detection rate of daytime hypertension in untreated hypertensive patients was 71.6% (277 patients); 3. The detection rate of nighttime hypertension in treated hypertensive patients was 81.2% (833 patients), while the detection rate of nighttime hypertension in untreated hypertensive patients was 87.6% (339 patients); 4. The detection rate of whole-day hypertension in treated hypertensive patients was 69.3% (711 patients), while the detection rate of whole-day hypertension in untreated hypertensive patients was 80.9% (313 patients); 5. The detection rate of morning hypertension in treated hypertensive patients was 61.1% (627 patients), while the detection rate of morning hypertension in untreated hypertensive patients was 72.9% (282 patients). Conclusions: In this study, the detection rate of EEE in treated hypertensive patients did not significantly decrease compared to those untreated patients, while the detection rate of EEE was similar to that of morning hypertension. It is necessary to conduct further research to reveal the correlation between EEE and cardiovascular diseases.

Study on a 20 K two-stage thermally-coupled pulse tube cooler with independent ambient displacers

Pulse tube cooler has the advantages of higher reliability and longer MTTF compared to Stirling cooler due to the elimination of moving components at the cold end. Pulse tube cooler working at liquid hydrogen temperatures has already become a strong candidate in sensor cooling, high-temperature superconductivity, etc. However, the efficiency of the pulse tube cooler at liquid hydrogen temperatures remains relatively low. In this paper, a two-stage thermally-coupled Stirling-type pulse tube cooler working at liquid hydrogen temperatures is designed and simulated. The first and second stage use independent ambient displacers as phase shifters. The simulation results show that the pulse tube cooler can reach a higher relative Carnot efficiency due to the improvement of the phase distribution of the whole system by using independent displacers. Meanwhile, the influence of factors such as average pressure and operating frequency on the system performance is also discussed.

UNATTENDED AUTOMATIC BLOOD PRESSURE MEASUREMENTS VS. CONVENTIONAL OFFICE READINGS IN PREDICTING HYPERTENSION-MEDIATED ORGAN DAMAGE

Objective: Hypertension, a major cardiovascular risk, requires accurate blood pressure measurement. Conventional office measurements (OBPM) are error-prone and systematically biased by the white coat effect. Unattended office blood pressure measurement (UOBPM) is emerging as an alternative to mitigate this bias. However, its ability to predict hypertension-mediated organ damage (HMOD), indicating disease progression, remains debated. This study compares UOBPM with OBPM in terms of their association with various HMODs, including left ventricular hypertrophy (LVH), left atrial enlargement (LAE), left ventricular systolic and diastolic dysfunction, intima-media complex (IMT) thickening, microalbuminuria and abnormal pulse wave velocity (PWV). Design and method: Hypertensive patients without overt cardiovascular disease were recruited, interviewed, and examined. Subsequently, blood pressure measurements were conducted in standard conditions in a randomized sequence in each patient: 1) UOBPM: After 5 minutes of solitary rest in the examination room, blood pressure was automatically measured three times at 1-minute intervals with OMRON HEM 907 device. 2) OBPM: After 5 minutes of rest, a physician performed three automated measurements at 1-minute intervals with the same device. Subsequent evaluations aimed to detect HMODs, including echocardiography, carotid artery ultrasound, PWV assessment, and laboratory tests. Receiver operating characteristic (ROC) analysis was performed for each HMOD in both measurement groups, and the areas under the ROC curves were compared. Results: The study enrolled 219 patients(55% females, mean age 55 ±14 years). The average systolic blood pressure in UOBPM was lower by 4,2 mmHg (p&lt;0,001) compared to OBP while the difference in diastolic pressure was 1,9 mmHg (p&lt;0,001). Both measurement methods were associated with the presence of the following HMODs: LAE, IMT thickening, and abnormal PWV. Neither method allowed for the prediction of LVH, systolic and diastolic dysfunction of the left ventricle, elevated ACR, or the presence of atherosclerotic plaques in the carotid arteries. Furthermore, ROC curve analyses revealed no difference between the two methods in predicting HMOD (Table 1). Conclusions: Both measurement techniques exhibited satisfactory predictive ability for the presence of certain HMOD. However, based on the study results, no significant differences could be inferred between the two methods with respect to their predictive performance.

AN UPDATED REPORT FROM THE HUNGARIAN AMBULATORY BLOOD PRESSURE MONITORING REGISTRY

Objective: Ambulatory blood pressure monitoring (ABPM) is recommended by current European guidelines for the early diagnosis of hypertension and to monitor the efficacy of antihypertensive treatments. The Hungarian Society of Hypertension has initiated a 5-year, nationwide program in 2021 to promote the routine use of ABPM and to improve the motivation of doctors and patients. This is an updated report on the Hungarian ABPM Registry. Design and method: This is an ongoing, multicenter, open-label, observational study. Adult (age &gt;18 years) patients with known hypertension(HT), or with suspected/newly diagnosed hypertension(nHT) can be involved in the study. ABPM monitoring is performed by GPs, internists, and cardiologists using validated Meditech ABPM-06 monitors. Current report analyzed ABPM data between 21.02.2021-16.11.2023, that were collected into an electronic case report. Overall, 40621 ABPMs were performed, due to protocol deviation 1901 patients were excluded from the analysis. Results: 26315 patients were HTs(68.3%), 12193 patients were nHTs(31.5%). In the HT group 95.5%, in the nHT group 21.5% were treated. 63.6% of all patients were hypertensives according to the 24-hour average blood pressure(BP) values. Mean 24-hour systolic and diastolic BP was 133.84±14.5 mmHg and 79.2±10.3 mmHg, respectively. There was no difference in the 24-hour mean systolic BP between HT and nHT patients (133.75±13.96mmHg vs. 133.86±14.72mmHg, respectively, p=NS). Obesity(BMI &gt;30 kg/m2) increased the risk of hypertension(OR=1.82[1.73;1.92]for 24-hour average). Coffee consumption(more than 3/day)(OR=1.22[1.16;1.29]for 24-hour average), snoring(OR=1.39[1.33;1.46]for 24-hour average)and smoking(OR=1.10[1.03;1.18]for 24-hour average)all increased the risk of hypertension, primarily affecting more the daytime BP values(OR=1.24[1.18;1.31]for daytime in coffee consumption, OR=1.13[1.07;1.19]for nighttime in coffee consumption; OR=1.42[1.36;1.49]for daytime in snoring, OR=1.31[1.25;1.38]for nighttime in snoring; OR=1.09[1.01;1.16]for daytime in smoking, OR=1.01[0.94;1.08]for nighttime in smoking (NS)). Lack of regular sport(less than 3x30 minutes weekly)increased the risk of hypertension(OR=1.11[1.05;1.18]for 24-hour average), primarily affecting more the nighttime values(OR=1.19[1.12;1.26]for nighttime, OR= 1.02[0.96;1.07]for daytime(NS)). Conclusions: Hypertension is highly prevalent in both HT and nHT patients, irrespectively of gender or treatment. Obesity, lack of regular sport, coffee consumption, snoring and smoking are all significant risk factors in developing hypertension, latter ones affecting more the daytime BP values, whereas lack of regular sport affects more the nighttime BP values.

An experimental study on gas-solid two-phase rotating detonation ramjet engine based on aluminum powder fuel

In order to explore the feasibility of solid powder detonation technology, the ground direct connection test of aluminum powder/hydrogen/air fuel detonation engine was carried out in this paper. The experimental results show that hydrogen is needed to achieve detonation combustion of aluminum powder with a diameter of 1 μm. A series of tests were carried out in the range of equivalence ratio of 0.8-1.2. With the increase of equivalence ratio, the mean value of steady pressure, average peak pressure, and average wave velocity of rotating detonation combustion increased first and then decreased gradually, and reached the maximum at the equivalence ratio of 0.9. The maximum propagation frequency of the detonation wave is 2653 Hz, and the average wave velocity is 1667 m/s.

Evaluation of tubal patency based on peak injection pressure in four-dimensional hysterosalpingo-contrast sonography among infertile females: a preliminary study.

Although the application of four-dimensional hysterosalpingo-contrast sonography (4D-HyCoSy) has relatively good diagnostic accuracy for assessing the patency of the fallopian tubes, the evaluation process mainly relies on morphological findings of the fallopian tubes and pelvic cavity. The purpose of this study was to explore the relationship of peak injection pressure during 4D-HyCoSy and tubal patency to provide a quantitative indicator for the evaluation of fallopian tube patency. This study included infertile patients who underwent 4D-HyCoSy and laparoscopic chromopertubation (LC) between 2020 and 2022, with LC serving as the reference test for assessing tubal patency. For the HyCoSy procedure, the ultrasound contrast agent was injected automatically using a liquid injection machine, and real-time pressure values were recorded. Patients were classified based on tubal patency status in LC as bilaterally patent, unilaterally patent, or bilaterally nonpatent. The average peak injection pressure and contrast agent volume of different groups were compared. Receiver operating characteristic (ROC) curve analysis was employed to determine the cutoff value. A total of 268 infertile patients were enrolled in the study. With LC as the standard examination, the sensitivity and specificity of 4D-HyCoSy in diagnosing nonpatent fallopian tubes were 91.1% and 95.1%, respectively. In general, peak injection pressure was observed to gradually increase as tubal patency decreased (P<0.001), with average peak injection pressures of 233.5±66.3, 338.8±99.8, and 469.6±63.1 mmHg in the bilaterally patent, unilaterally patent, and bilaterally nonpatent groups, respectively. The volume of contrast agent used in patients in the bilaterally nonpatent group was significantly lower than that in the other two groups (P<0.01), with average volumes of 22.7±6.3, 24.3±9.3, and 18.9±9.2 mL, respectively. When one fallopian tube was patent, the area under the curve (AUC) for distinguishing obstruction from patency of the other fallopian tube was 0.827, with a sensitivity of 79.8% and a specificity of 74.3% (cutoff value: 254.3 mmHg). Similarly, when one fallopian tube was nonpatent, the AUC was 0.866, with a sensitivity of 90.6% and a specificity of 78.3% (cutoff value: 401.3 mmHg). Peak injection pressure during 4D-HyCoSy demonstrates promising diagnostic performance in evaluating fallopian tube patency in infertile patients.

Multiphase flow simulation in hybrid porous structure

Recent research has primarily focused on creating biporous and hybrid porous structures with multiple pore sizes and length scales to optimize capillary pressure and permeability. Despite numerous experimental investigations on biporous and hybrid media, there is a noticeable absence of numerical simulations that explore the multiphase flow within these media. Therefore, the present study aims to conduct a pore-scale numerical simulation of two-phase flow in a biporous structure. The biporous structure is proposed by arranging clusters of solid particles in a staggered regular pattern, with each cluster consisting of closely packed particles. The dimensions and characteristics of the simulated structure are based on previous experimental literature on biporous and hybrid media. A monoporous structure simulation is also included for comparison with biporous results. ANSYS Fluent is utilized to carry out the numerical simulations of capillary pumping flow. The simulation results indicate that the permeability and average capillary pressure of the biporous media are four times and over one and a half times higher, respectively, compared to those of the monoporous media. The presence of smaller pathways within each cluster of a biporous and hybrid porous media enhances the capillary effect in comparison to conventional monoporous structures. Additionally, the larger pores between the clusters contribute to a higher permeability of the hybrid porous structure. As a result, the combined effect of increased capillary action and higher permeability leads to improved performance of the hybrid porous structure. Overall, the proposed simplified biporous geometry accurately models fluid flow in real, complex biporous and hybrid structures.

EFFECT OF RENAL DENERVATION ON 24H BLOOD PRESSURE PATTERN

Objective: Endovascular renal denervation (DRN) is a therapeutic approach for resistant arterial hypertension (RH). The aim of this study was to assess the effects of RDN on 24h blood pressure. Design and method: A retrospective evaluation of ABPM data at baseline and after 6 months from RDN in patients undergoing DRN between 01/01/2011 and 31/12/2021 in the Arterial Hypertension Center of Turin. Mean 24h, Daytime, Nighttime BP and HR values and short term 24h, daytime and nigthtime BP and HR varability parameters (standard deviation, dipping and coefficient of variation) were calculated. Results: The series included 14 subjects, of which 8 (57%) were female and with an average age 54±10 years. The number of antihypertensive drugs before renal denervation was 5.7±1.0. At baseline office BP was 188/113±22±18 mmHg and ABPM 24h BP was 150/92±21±16 mmHg. Patients were considered as responders if a reduction of least 10 mmHg in systolic blood pressure (PAS) at 24h Blood Pressure Monitoring at six months from RDN was obtained. From a safety point of view, there were no short-term or long-term complications. The responders at six months were 66%. Non-responders showed an increased blood pressure variability compared to responders at baseline and only one was dipper. The responders had a statistically significant redution of SD24h after DRN, an increased average nocturnal blood pressure drop and a lower pressure variability. While in non-responders no redution in SDnight, SDday and coefficient of variation was found, by contrast all of them become dippers because mean daytime SBP increase. Conclusions: In conclusion, pressure variability (SD24h and coefficient of variation) is globally reduced in the denerved patients, this trend is particularly present in responders. The non-responders have an increased BP variability at baseline without decreasing after DRN. These results suggest that, when effective, DRN can reduce both BP levels and BP variability, thus may have an important effect in reducing cardiovascular risk.