Pressure Values Research Articles

#1784 The potential impact of chronic subclinical hypervolemia on left ventricular hypertrophy in children on dialysis: a prospective longitudinal study

Abstract Background and Aims Hypervolemia poses a significant challenge in pediatric patients undergoing dialysis, potentially leading to severe complications such as left ventricular hypertrophy (LVH) and cardiac dysfunction. Accurately assessing fluid status in growing children on dialysis could be particularly difficult, and although several non-invasive methods are emerging, each individual measurement has its own strengths and diagnostic limitations in terms of sensitivity and specificity. To date, only a few studies in children have compared the use of different methods simultaneously to detect fluid status, and none of these have evaluated the potential cardiovascular impact of a prolonged subclinical hypervolemia. The latter can be defined as a condition of euvolemia at clinical assessment but hypervolemia at technical evaluation. We evaluated the role of three methods—lung ultrasound (LUS), bioimpedance spectroscopy (BIS), and ultrasound assessment of inferior vena cava collapsibility index (IVC-CI)—in detecting subclinical hypervolemia and examined the cardiac implications. Method In this prospective observational longitudinal study, we included 23 children (<18 years) who were receiving chronic hemodialysis or peritoneal dialysis at the regional pediatric nephrology center of Meyer University Children's Hospital IRCSS, Florence, Italy, between 01/06/2018 and 01/11/2020. We excluded patients with clinical signs of fluid overload. Each patient underwent a multiparametric evaluation of their fluid status (physical examination, LUS, IVC-CI, BIS) every 2 months, and an echocardiography every six months starting from a baseline evaluation. The LVH was defined as a left ventricular mass index (LVMI) of ≥ 95th percentile or a left ventricular wall-thickness z-score > 2 z-score. We divided the patients into two groups and arbitrarily assigned them to the subclinical hypervolemia (SH) group if they had at least two out of three parameters of fluid overload at different methods (≥5 B-lines at LUS, overhydration normalized to extracellular water “OH/ECW” > 7% at BIS, and/or IVC-CI < 40%) in the absence of clinical signs of fluid overload. The others were included in the euvolemic (EU) group. The overload rate by weight (clinical OH), prescribed by the physician clinically, was calculated as the proportional increase from the dry weight (kg of fluid overload / dry weight in kg × 100). Results The two analyzed groups did not differ regarding gender, age and BSA (Table). The clinical OH was significantly higher in the SH population than in the EU group (2.2 ± 1.84 vs 1.30 ± 2.16%, p < 0.01). In the correlation analysis, we found that clinical OH positively correlated with the number of B-lines by LUS (R = 0.2923, p < 0.001) and OH/ECW by BIS (R = 0.4144, p < 0.001), while there was a negative correlation with IVC-CI (R = −0.2597, p = 0.019). However, each method taken individually (LUS, BIS, and IVC-CI) appeared to be inaccurate in predicting fluid status in several individual cases. Although the frequency of hypertension did not differ between the SH and EU groups, uncontrolled hypertension, treatment-resistant hypertension, and hospital admission for hypertensive crises were more frequent in the SH group, with the latter being statistically significant (67% vs 0%, p < 0.01). Furthermore, in the entire cohort, we observed a significant linear correlation between LVMI values and the average values of pre-HD systolic blood pressure recorded in the prior six months (R2 = 0.16, p = 0.002). It is worth noting that the presence of LVH at the last follow-up was significantly more prevalent in the SH group (75% vs 27%, p = 0.04). Conclusion Chronic subclinical hypervolemia, detected with a multi-method evaluation (including LUS, BIS, and IVC-CI), was significantly correlated with clinical OH and associated with a higher risk of LVH. To mitigate the intrinsic limitations of each technique, adopting two or more methods simultaneously can bypass and minimize the risk of evaluative error in assessing fluid status, and help reduce cardiovascular risk.

#3009 The impact of living donor hypertension on later function of kidney graft in kidney transplantation

Abstract Background and Aims Living donor (LD) selection is a crucial step in kidney transplantation (KTX). The impact of hypertension (HT) of LD on later kidney graft function remains insufficiently understood. Method We retrospectively reviewed recipients of LD KTX at a single tertiary center (Geneva University Hospitals, Geneva, Switzerland) from January 2003 to December 2021 with a follow-up until December 2022. LD blood pressure (BP) values obtained with office measurement and 24 h ambulatory BP monitoring (ABPM) were the main predictors, while recipients estimated glomerular filtration rate (eGFR) and proportion of kidney fibrosis on biopsies were the outcomes. Multivariate analyses were adjusted for the following pre-KTX donor characteristics: Age, gender, ethnicity, body mass index and eGFR. Results In total, 212 LD KTX recipients were included with LD mean age 51 ± 11 and 133 women (62.7%). According to European guidelines definition, 73 (34.4%) LD were hypertensive based on office BP. On a sub-group of 112 LD with ABPM, 64 (57.1%) were hypertensive. Systolic office BP was negatively associated with eGFR at 6 months, 1 year, 5 year and 10 year follow-up (p < 0.05 for all). Systolic office BP was positively associated with kidney fibrosis at 1 year follow-up (p < 0.05). Those associations were not significant after multivariate adjustment. Age at donation remained significantly associated eGFR and kidney fibrosis after multivariate adjustment (p < 0.05 in both models). Conclusion Based on our experience, a significant proportion of LD are hypertensive at kidney donation. While an adverse impact of HT on later kidney function and fibrosis could be measured, this effect seemed negligible after accounting for other more relevant clinical characteristics, with age at donation being decisive.

#1610 FGF23-mediated hypertension via augmented calcium entry in vascular smooth muscle cells

Abstract Background and Objectives Ongoing studies are shedding light on the potential connection between FGF23 and hypertension. In experimental settings, the administration of recombinant FGF23 in mice has been demonstrated to induce hypertension by elevating serum sodium, along with an increase in NCC receptors in the kidney. Clinical evidences further supports pro-hypertensive effects of high circulating levels of FGF23. Our group has previously demonstrated a direct influence of FGF23 on increased arterial stiffness by inducing a phenotypic transition in vascular smooth muscle cells (VSMCs) from a contractile to a synthetic phenotype. This study aimed comprehensively to evaluate, both in vivo and in vitro, whether FGF23 directly leads to hypertension through the stimulation of intracellular calcium entry in vascular cells. Methods To ascertain whether FGF23 contributes to hypertension through a direct impact on blood vessels, recombinant FGF23 (15 µg/day) was administered for 28 days via Alzet pumps. Blood pressure was meticulously measured in these animals, and we investigated alterations in vascular remodeling and calcium channels, as well as proteins associated with vascular contraction such as Orai1, STIM1, PKD1, SERCA2a, and AGTR1. In vitro experiments included the evaluation of the effect of elevated levels of recombinant FGF23 (2 ng/ml) over 9 days on intracellular calcium entry stimulated by Ang2 (100 nM) or Thapsigargin (2.5 µM). We used the FURA method to conduct these experiments. To elucidate the in vitro pro-hypertensive mechanisms of FGF23, studies were conducted with the administration of inhibitors targeting FGF Receptors 1-3 (AZD4547, 150 nM), FGF Receptor-4 (BLU9931, 10 nM), and Erk1/2 phosphorylation (PD98059, 10 μM). Additionally, changes in Orai1, STIM1, PKD1, SERCA2a, and AGTR1 were also evaluated in these VSMCs. Results After 28 days of recombinant FGF23 treatment, no significant differences were observed in serum sodium levels, yet there was a marked increase in urinary phosphorus excretion. Systolic and diastolic blood pressure values showed a progressive significant elevation in animals exposed to high levels of FGF23. The expression of AGTR1 and PKD1 levels significantly increased after FGF23 administration for 28 days (Figure). However, Orai1 and STIM1 in the thoracic aorta exhibited no significant differences following FGF23 treatment. In VSMCs, the exposure to recombinant FGF23 for 9 days resulted in increased calcium entry upon Ang2 stimulation (Figure). This effect was markedly diminished after inhibiting FGFR1-3 receptors and Erk1/2 phosphorylation (Figure). Notably, the inhibition of FGF23 receptor 4 (FGFR4) had no impact on the calcium entry induced by FGF23 (Figure). While Orai1, STIM1, IP3R, and TRPV5 in VSMCs remained unaffected by recombinant FGF23 administration, PKD1, SERCA2, and AGTR1 levels were significantly elevated compared to control cells (Figure). The addition of Thapsigargin in a Ca2+-free culture medium to VSMCs incubated with recombinant FGF23 for 9 days led to increased Ca2+ efflux from endoplasmic reticulum. Conclusion Elevated levels of FGF23 directly enhanced calcium entry in VSMCs. This effect is mediated by FGFR1-3 receptors, Erk1/2 phosphorylation, and the upregulation of related protein to cell contraction such as SERCA2a, PKD1 or AGTR1. These modifications could be responsible of FGF23-associated hypertension in the experimental model.

#3092 Case report: Renal cystic disease caused to heterozygous NEK8 variant in pediatric patient

Abstract Background and Aims Polycystic kidney diseases (PKDs) are the most prevalent inherited kidney disease [1]. They are caused by pathogenic variants in genes encoding for proteins with roles in the functioning of primary cilium, a sensory organelle at the cell surface of almost all cells regulating key signaling pathways. Therefore, they are also classified as Ciliopathy and can occur with isolated renal involvement with/without systemic manifestations. As 1 of the family of “Never in Mitosis A–related kinases” (NEK), NEK8 is a regulator of Hippo pathway that controls cell growth, regulate the renal tubule epithelial cell cytoskeletal structure, and is involved in ciliary biogenesis/function. Biallelic NEK8 mutations are reported as causing a syndromic ciliopathy with multiorgan developmental defects, referred to as renal-hepatic-pancreatic dysplasia [1]. A recent paper [1] analyzed a total of 21 patients from 12 families with heterozygous NEK8 variants and cystic kidney disease and proposed a dominant negative effect for specific heterozygous variants in the NEK8 kinase domain as a new cause of PKD. Method We describe a case report of PKD associated with NEK8 heterozygous mutation. Results 8 years old female patient accessed to Emergency Department with first evidence of isolated macro-hematuria. Previous medical history was unremarkable. The girl was afebrile, in good clinical condition, with elevated blood pressure values (120/82 mmHg) at the physical examination. The laboratory tests showed normal blood count with hemoglobin 11.7 g/dl, serum creatinine 0.42 mg/dl, no inflammatory markers. Urinalysis revealed proteinuria (100 mg/dL), hemoglobinuria, active urinary sediment with microhematuria (3557 red blood cell/microliter) and leukocyturia (535 white blood cells/microliter). An abdominal ultrasound study observed kidneys of increased size (longitudinal diameter of approximately 14 cm) with presence of multiple cystic formations with a maximum diameter of 2 cm and lost cortico-medullary differentiation; other organs were normal. Ultrasound findings were confirmed with MRI. The macrohematuria resolved quickly, however we recorded the persistence of positive urinary sediment. No other concomitant clinical manifestations were recorded and the cardiological evaluation was normal. Suspecting a cystic renal disease, we proposed a genetic analysis by whole exome sequencing (WES): an heterozygous NEK8 variant (c.133C>T, p. Arg45Trp) was found. Due to persistent proteinuria and hypertension we suggested to initiate RAAS inhibitor treatment. Conclusion The patient's clinical history and onset of disease agree with the data described in the literature for the NEK8 variant c.133C>T, p. Arg45Trp. In literature all patients had an early onset of PKD. Enlarged kidney were present in 79%, followed by hypertension in 67% of cases; no patients had liver involvement, as in our patient. Kidney failure occurred before adulthood in non-mosaic case. The absence of a phenotype with systemic involvement, doesn't exclude the possible subsequent appearance of extra-renal manifestations. Therefore, it is necessary to set up a multidisciplinary follow-up, including cardiological evaluation and radiological study of brain structure. An early nephroprotective therapy and behavioral strategy must be established to prevent disease progression. Thus, it is suggested to include NEK8 in the genetic analysis when PKD is suspected.

#1833 Analysis of clinical and laboratory manifestations in different classes of lupus nephritis—a Serbian single center experience

Abstract Background and Aims Lupus nephritis represents one of the most serious manifestations of systemic lupus erythematosus. The gold standard for determining the class of lupus nephritis is percutaneous kidney biopsy and the histopathological analysis of the biopsy specimen. The aim of this study was to analyze the clinical and laboratory characteristics of different histopathological classes of lupus nephritis (LN) at the time of the systemic lupus diagnosis and onset of symptoms. Method This retrospective cross-sectional study included a total of 54 subjects who were hospitalized at the Clinic for Nephrology and Clinical Immunology of the University Clinical Center of Vojvodina from 2017 to 2022 and underwent percutaneous kidney biopsy. Available clinical and laboratory data, as well as the histopathological findings of kidney biopsies, were analyzed. Based on the histopathological classification, patients were divided into four groups (Class II, III, IV, and V), and the clinical and laboratory characteristics were analyzed for all subjects. Due to a low number of patients, no analysis of Class I and Class VI was made. Results The most prevalent class among the subjects was Class IV, in which the lowest values of the C3 complement component were recorded. Subjects in this LN class had higher blood pressure values, a higher frequency of clinical manifestations such as arthralgia, and joint swelling. Class IV LN was also associated with elevated anti-dsDNA antibody values with a significant statistical significance (p = 0.004), lower red blood cell parameters, and higher levels of nitrogenous substances compared to other classes. The lowest values of total serum proteins and albumins, as well as the highest values of total cholesterol, LDL cholesterol, and triglycerides, were observed in the group of subjects with Class V LN; C-reactive protein had the highest average values in Class III and IV, which showed a statistical significance (p = 0.007). The lowest values of total serum calcium and iron were in Class III, and 24-hour proteinuria was most pronounced in Class V (p = 0.001), whereas microscopic hematuria was most present in Class II LN (p = 0.03). Conclusion Patients with lupus nephritis exhibit different clinical and laboratory manifestations based on histopathological classification and the time of diagnosis. The results of this study suggest their potential use in diagnosis, assessment of histopathological classification, and the development of a targeted and personalized therapeutic approach. These parameters will be used to develop machine learning models which might help in further evaluation and treatment.

#1112 A simplified lung ultrasound guided management protocol of pulmonary congestion in hemodialysis

Abstract Background and Aims Pulmonary congestion PC is frequent in Hemodialysis HD and holds a negative prognostic value. Lung ultrasound LUS is accurate in detecting and quantification PC, however, there are many methods to use LUS to evaluate PC. Here we validate a simplified LUS guided pulmonary congestion management protocol in HD patients that can be easily integrated in clinical practice, while studying at the same time the impact of such method on blood pressure control. Methods A prospective randomized multi-centric trial including stable HD patients in 3 countries. Patients were randomized into two groups: active and control group. All patients had a bedside LUS at the end of their mid-week session every two weeks according to the following time-line: Day 1, 15, 30, 45, 60. Lung ultrasound was performed according to the 8-zone method, and a B line score BLS was obtained. A global BLS of more than 6 was considered reflecting a significant PC level. The dry weight was adapted according to the standard of care in the control group. In the active group, in addition to the standard of care, if BLS was more than 6 at day 1 then the dry weight was reduced by 500 g. The same procedure was repeated at Day 15. (The maximum global dry weight modification per patient was 1 kg) (Fig. 1). Home blood pressure monitoring HBPM was also obtained weekly all through the study period. Results 28 stable HD patients (21 males) were enrolled in the study up until now. Mean age was 66.4 years, 14 were diabetics, 4 with stable ischemic heart disease, 1 heart failure and 27 were suffering from hypertension. Mean dialysis vintage was 35.8 months, and mean residual urine volume was 548 ml/24H. Mean session time was 4 hours. Main study population characteristics are described in Table 1. In the active group, mean BLS at day 1 (13.5) was significantly reduced, and reached (7.57) at day 60. (P < 0.001, ES:1.55) (Fig. 2). This was in parallel with a little but significant reduction in the dry weight (P: 0.03, ES: 0.6) but without a statistically greater UF values (P: 0.23) (Table 2). A significant reduction in home blood pressure was also observed by the HBPM readings, especially in the diastolic BP (P: 0.004). In the control group, the mean BLS at day 1 was (12.1). This level did not change all through the study time line, as it was (12.1) at day 60. No significant difference was observed in the dry weight, or ultrafiltration rate UF or home blood pressure values (Table 3). Conclusion Our simplified LUS guided management protocol was able to safely reduce the pulmonary congestion in HD patients in addition to better controlling their blood pressure. This protocol can be applied easily in every HD unit, and may be added to the standard of care to better estimate the dry weight in HD patients.

Nanofillers embedded flexible piezoelectric polymer sensor pad for robotic and human finger tap analysis

Flexible pressure sensors are receiving a lot of attention due to their use in wearable electronic devices, human-machine interactive systems, and physiological signal monitoring. In this paper, we present a novel nanofiller embedded thin film based piezoelectric pressure sensor for finger tapping analysis. The active material is fabricated using poly (vinylidene fluoride) (PVDF) having zirconium oxide (ZrO2) nanofillers. It is observed that the incorporation of ZrO2 nanofillers has a substantial impact on the structural characteristics of PVDF polymer, leading to enhancements in its piezoelectric properties. Moreover, the PVDF/2 wt% ZrO2 composite film sensor showed a notable maximum piezoelectric output voltage of ∼210 millivolts at a load of 20 g (0.88 kPa applied pressure). A four-fold enhancement in response is observed in case of PVDF/2 wt% ZrO2 composite in comparison to pristine PVDF sensor. Further, a sensitivity of 0.255 ± 0.083 kPa−1 has been recorded for the composite based sensor. Additionally, maximum of 115 mV is obtained when the composite sensor is tapped manually. The recorded maximum values for impulsive pressure (38 g), high pressure (108 g), and low pressure (45 g) are 76 mV, 150 mV, and 90 mV, respectively. The sensor is efficiently able to detect robotic tapping and stress on the human fingers. An efficiency of around 90% was achieved in PVDF/ 2 wt% ZrO2 at 5 kV/cm using PE hysteresis loop data. The findings indicate that PVDF/ZrO2 composite based piezoelectric pressure sensor has promising capabilities for applications in wearable electronic devices and medical diagnostics.

A novel method for evaluating stack pressure in real high-rise buildings: Optimization of measurement points

Excessive stack pressure in a high-rise building always causes various problems, and the most direct way to understand the extent of the stack pressure across building components is to derive pressure distribution profiles for the entire buildings. As an alternative to measurement process, which is generally time-consuming and labor-intensive, an optimal field measurement method is proposed to investigate the real-time pressure distribution in operating high-rise buildings. The absolute pressure at unmeasured points can be accurately predicted from measured values at selected key points, both horizontally and vertically. Robust linear regression and the MARS model are applied to develop the related prediction models, and the number and positions of measurement points in the horizontal and vertical directions are optimized sequentially. Two high-rise buildings were selected to validate the applicability of the method, and five and six key pressure measurement points were finally determined, respectively. The measured and predicted absolute pressure values at unmeasured points were further compared, and the results showed a high goodness of fits as the R2 values were higher than 0.98 and the average MAE values were less than 2.0 Pa for all models. It is observed that the proposed method is suitable for engineering applications and demonstrates a practical method for investigating stack pressure distribution within high-rise buildings.

Relationships between Dairy Consumption Patterns and Hypertension, Overweight, and Obesity Status

Background: Obesity is considered a widespread concern internationally. Few studies have investigated the relationships between dairy consumption and hypertension and obesity. Therefore, this study examined the above concern in students. Method: This cross-sectional study was conducted on 292 male students (18–30 y) living in the dormitories of Tabriz University of Medical Sciences. Students were selected via the multistage stratified random sampling method. Demographic information, anthropometric measurements, blood pressure (BP) readings, and a semi-quantitative validated questionnaire assessing dairy consumption (including a 24-hour dietary record covering 2 typical days and a holiday) were collected. After all the questionnaires were reviewed, they were coded and analyzed with Nutritionist IV software. Results: The average age of the subjects was 22.36 years. The mean±SD values of body mass index (BMI), waist circumference, waist-to-hip ratio, and waist circumference-to-standing height ratio were 22.68±2.58 kg/m², 80.95±7.81 cm, 0.85±0.04, and 0.46±0.04 among the studied population, respectively. The mean±SD values of systolic and diastolic blood pressure were 111.84±10 mm Hg and 70.99±8 mm Hg, respectively. Milk consumption was associated with a low waist circumference (95% credible interval, 1.005 to 4.580; P=0.046). The odds of hypertension (defined as BP>120/90 mm Hg) were 2.686 times higher in the overweight and obese group than in the normal BMI group. The risk of hypertension was 1.045 times higher for individuals with abdominal obesity than for those who did not consume dairy products. Conclusion: Milk consumption was associated with a low waist circumference. The correlations between systolic blood pressure and anthropometric factors were statistically significant. BMI, waist circumference, and waist-to-hip ratio were positively associated with systolic blood pressure.

Ventilation improvement for effective protection of healthcare workers in negative pressure airborne infectious isolation room from viral aerosols

A negative pressure airborne infectious isolation room (AIIR) is the primary healthcare air contamination control system used for the treatment of severe respiratory infectious patients. Effects of the ventilation system configuration and conditions on airflow pattern, aerosol distribution and ventilation performance were investigated using computational fluid dynamics (CFD). The field measurement by SARS-CoV-2 environmental surface test was also conducted. The cycle threshold values from transcription polymerase chain reaction (RT-PCR) method showed inverse relation to the simulated number of particles trapped on the surfaces indicating a good agreement. Modification of the present AIIR to have alignment between air inlet and outlet where the aspect ratio of the air outlet, Width (W): Height (H) = 1:1 (Improved case: IC#1) showed a 78 % reduction of aerosol concentration in healthcare workers (HCWs) zones. Aerosol concentrations were increased when the openings of the air outlet were enlarged. Addition of air outlet led to large swirling air, resulting in more aerosols being trapped and suspended in the air. Results suggested that AIIR with alignment air inlet on the ceiling and air outlet at the wall over the patient's head with W:H = 1:1 be the most suitable configuration to maximize the ventilation performance and minimize exposure risk to aerosolized viral infection for HCWs. Air change rate plays a more important role than the differential pressure on the removal efficiency. The differential pressure value should be at least −2.5 Pa and the air supply rate 12 ACH for effective protection of HCWs in the negative pressure AIIR.

Identification of excessive contact pressures under hand orthosis based on finite element analysis.

Implicit magnitudes and distribution of excessive contact pressures under hand orthoses hinder clinicians from precisely adjusting them to relieve the pressures. To address this, contact pressure under a hand orthosis were analysed using finite element method. This paper proposed a method to numerically predict the relatively high magnitudes and critical distribution of contact pressures under hand orthosis through finite element analysis, to identify excessive contact pressure locations. The finite element model was established consisting of the hand, orthosis and bones. The hand and bones were assumed to be homogeneous and elastic bodies, and the orthosis was considered as an isotropic and elastic shell. Two predictions were conducted by assigning either low (fat) or high (skin) material stiffness to the hand model to attain the range of pressure magnitudes. An experiment was conducted to measure contact pressures at the predicted pressure locations. Identical pressure distributions were obtained from both predictions with relatively high pressure values disseminated at 12 anatomical locations. The highest magnitude was found at the thumb metacarpophalangeal joint with the maximum pressure range from 13 to 78 KPa. The measured values were within the predicted range of pressure magnitudes. Moreover, 6 excessive contact pressure locations were identified. The proposed method was verified by the measurement results. It renders understanding of interface conditions underneath the orthosis to inform clinicians regarding orthosis design and adjustment. It could also guide the development of 3D printed or sensorised orthosis by indicating optimal locations for perforations or pressure sensors.

Improving the efficiency of the fuel horizontal tank fleet management system

The active use of helicopter transportation to facilitate the construction and operation of oil and gas facilities in the Far North has resulted in the establishment of refueling points, which include fuel tank farms. The evaporation of fuel during the filling and storage of fuel in tanks is the primary cause of product loss, which results in economic damage and environmental pollution. The lack of scientifically substantiated technical solutions to prevent fuel losses means that it is not possible to completely eliminate fuel losses. The objective of this article is to develop a control system for a fleet of horizontal tanks that minimizes fuel losses. The development is based on a study of the factors affecting the volume of evaporation, which are divided into three categories: those that can be controlled, those that cannot be controlled, and those that can be controlled and influenced. The result is a schematic solution of the automated control system that performs condensation of fuel vapours evaporating in the process of tank farm operation, and also determines the priority of tank use depending on the value of vapour pressure in them. This makes it possible to reduce fuel losses by a factor of five.

Patient knowledge about risk factors, achievement of target values and guideline adherent secondary prevention therapies 12 months after acute myocardial infarction.

The prospective GULLIVE-R study aimed to evaluate adherence to guideline recommended secondary prevention, physicians' and patients' estimation of cardiac risk, and patients' knowledge about target values of risk factors after acute myocardial infarction (AMI). We performed a prospective study enrolling patients 9-12 months after AMI. Guideline recommended secondary prevention therapies and physicians as well as patients' estimation about their risk, and patients' knowledge about target values were prospectively collected. Between 07/2019 and 06/2021 a total of 2509 outpatients were enrolled in 150 German centers 10 months after AMI. The mean age was 66 years, 26.4% were women, 45.3% had STEMI, 54.7% had NSTEMI, 93.6% had revascularization (84.0% PCI, 7.4% CABG, 1.8% both). Guideline recommended secondary drug therapies were prescribed in over 80% of patients, while only about 50% received all five recommended drugs (aspirin, P2Y12 inhibitors, statins, beta-blockers, RAAS inhibitors) and regular exercise was performed by only one third. About 90% of patients felt well informed about secondary prevention, but the correct target value for blood pressure was known in only 37.9% and for LDL-C in only 8.2%. Both, physicians and patients underestimated the objective risk for future AMIs as determined by the TIMI risk score for secondary prevention. There is still room for improvement in patient education and implementation of guideline recommended non-pharmacological and pharmacological secondary prevention therapies in patients in the chronic phase after AMI.

Optical coherence tomography findings in primary headache disorders: is pain duration a clinical correlate?

Objective Ganglion cell layer thickness (GCLT) may be used as a potential marker for central neural changes. We compared GCLT by using spectral domain optical coherence tomography (SD-OCT) in patients with primary headache disorders and healthy controls. We seek whether there was any difference between the headache groups and whether any clinical parameters correlated to GCLT. Methods Fifty-three primary headache patients, 11 age and sex-matched healthy subjects were included in this cross-sectional study after power analysis. All subjects underwent SD-OCT. The duration of disorder, headache frequency, severity, duration of pain, presence of ocular pain, and accompanying symptoms have been collected. Results Mean GCLT of the headache group was 15.7 ± 3.8 µm (mean ± standard deviation), and the control group was 17.5 ± 2.4. The difference was not statistically significant. When we compared the controls, migraine and tension-type headache patients’ GCLT values, we found a significant difference (ANOVA, p = 0.001). Migraine patients had thinner GCLT compared to all non-migraine headache patients (p = 0.01). Intraocular pressure values of migraine patients and non-migraine patients were not statistically significantly different (p = 0.13). The only clinical parameter that correlated with GCLT was pain duration (r = −0.43 and p = 0.01). The patients with white matter lesions had thinner GCLT (p = 0.046). Conclusion Our results suggest that not long-term suffering from pain but migraine pathophysiology itself seems to affect neuroretinal tissue. Pain duration was moderately and inversely correlated to GCLT, meaning that the longer the headache, the thinner the ganglion cell layer is.

Discriminating "impaired" from "disordered" contractile response on FLIP panometry by utilizing pressure measurement.

Functional lumen imaging probe (FLIP) panometry evaluates esophageal motility, including the contractile response to distension, that is, secondary peristalsis. Impaired/disordered contractile response (IDCR) is an abnormal, but nonspecific contractile response that can represent either hypomotility or spastic motor disorders on high-resolution manometry (HRM). We hypothesized that FLIP pressure could be incorporated to clarify IDCR and aimed to determine its utility in a cohort of symptomatic esophageal motility patients. 173 adult patients that had IDCR on FLIP panometry and HRM with a conclusive Chicago Classification v4.0 (CCv4.0) diagnosis were included and analyzed as development (n = 118) and validation (n = 55) cohorts. FLIP pressure values were assessed for prediction of either hypomotility or spasm, defined on HRM/CCv4.0. HRM/CCv4.0 diagnoses were normal motility in 48 patients (28%), "hypomotility" (ineffective esophageal motility, absent contractility, or Type I or II achalasia) in 89 (51%), and "spasm" (Type III achalasia, distal esophageal spasm, or hypercontractile esophagus) in 36 (21%). The pressure at esophagogastric junction-distensibility index (DI) (60 mL) was lower in hypomotility (median [interquartile range] 34 [28-42] mmHg) than in spasm (49 [40-62] mmHg; p < 0.001) and had an area under the receiver operating characteristic curve of 0.80 (95% CI 0.73-0.88) for hypomotility and 0.76 (0.69-0.83) for spasm. For "spasm" on HRM, a threshold FLIP pressure of >35 mmHg provided 90% sensitivity (47% specificity) while >55 mmHg provided 93% specificity (40% sensitivity). Pressure on FLIP panometry can help clarify the significance of IDCR, with low-pressure IDCR associated with hypomotility and high-pressure IDCR suggestive of spastic motor disorders.

Speckle Plethysmograph-Based Blood Pressure Assessment

Continuous non-invasive blood pressure (CNBP) monitoring is of the utmost importance in detecting and managing hypertension, a leading cause of death in the United States. Extensive research has delved into pioneering methods for predicting systolic and diastolic blood pressure values by leveraging pulse arrival time (PAT), the time difference between the proximal and distal signal peaks. The most widely employed pairing involves electrocardiography (ECG) and photoplethysmography (PPG). Possessing similar characteristics in terms of measuring blood flow changes, a recently investigated optical signal known as speckleplethysmography (SPG) showed its stability and high signal-to-noise ratio compared with PPG. Thus, SPG is a potential surrogate to pair with ECG for CNBP estimation. The present study aims to unlock the untapped potential of SPG as a signal for non-invasive blood pressure monitoring based on PAT. To ascertain SPG’s capabilities, eight subjects were enrolled in multiple recording sessions. A third-party device was employed for ECG and PPG measurements, while a commercial device served as the reference for arterial blood pressure (ABP). SPG measurements were obtained using a prototype smartphone-based system. Following the completion of three scenarios—sitting, walking, and running—the subjects’ signals and ABP were recorded to investigate the predictive capacity of systolic blood pressure. The collected data were processed and prepared for machine learning models, including support vector regression and decision tree regression. The models’ effectiveness was evaluated using root-mean-square error and mean absolute percentage error. In most instances, predictions utilizing PATSPG exhibited comparable or superior performance to PATPPG (i.e., SPG Rest ± 12.4 mmHg vs. PPG Rest ± 13.7 mmHg for RSME, and SPG 8% vs. PPG 9% for MAPE). Furthermore, incorporating an additional feature, namely the previous SBP value, resulted in reduced prediction errors for both signals in multiple model configurations (i.e., SPG Rest ± 12.4 mmHg to ±3.7 mmHg for RSME, and SPG Rest 8% to 3% for MAPE). These preliminary tests of SPG underscore the remarkable potential of this novel signal in PAT-based blood pressure predictions. Subsequent studies involving a larger cohort of test subjects and advancements in the SPG acquisition system hold promise for further improving the effectiveness of this newly explored signal in blood pressure monitoring.

Next-Gen Lubrication: Water-cooled thrust bearings in conjunction with nano fluid lubricant

Thrust bearing finds application as a key element for heavy duty machines such as hydro-power plants (vertical shaft), submarines, steam engines, cement plant-ball mills (horizontal shaft) etc. Bearing temperature is a primary factor that affects the performance of hydrodynamic thrust bearings. Thermal deformation, misalignment, reduction in minimum oil film thickness and subsequent drop in load carrying capacity, are some of the manifestations related to high bearing temperatures. The present study attempts to decrease the bearing temperature by utilizing novel hybrid bearing set up. It involves the integration of water-cooled pads coupled with nanoparticle-infused lubricant films. This approach represents a convergence of two key technologies aimed at addressing the thermal effects linked with elevated temperatures generated during the operation of bearings. This study utilizes computational simulations to evaluate the effect of integrated thrust pad design on performance characteristics like pressure, temperature, and thermal deformation of a thrust bearing. The simulation results of new integrated design confirm (i) enhancement in pressure values e.g. maximum pressure increases from 5.6 MPa to 6.5 MPa (ii) reduction of pad temperature values e.g. maximum pad temperature value reduces from 85℃ to 70℃ (iii) reduction of pad thermal deformation values e.g. maximum pad thermal deformation value reduces from 36.5 µm to 22.3 µm. By leveraging the direct cooling effect of embedded cooling circuitry and the enhanced thermophysical properties of nanoparticles, this novel configuration promises to unlock new levels of efficiency and reliability in thrust bearing operation.

Sleep Quality in Greek Adolescent Swimmers.

The aim of our study was to investigate the relationship between sleep quality and functional indices, swimming distance and gender in adolescent competitive swimmers. Forty-eight adolescent swimmers (boys, n = 22, 15.7 ± 1.0 years and girls, n = 26, 15.1 ± 0.8 years) were included in our study. They were assessed for handgrip strength, respiratory muscle strength and pulmonary function, answered a Pittsburg Sleep Quality Index questionnaire (PSQI), and recorded their anthropometric and morphological characteristics and training load for the last four weeks. The results showed differences between swimming distance and chest circumference difference, between maximal inhalation and exhalation (Δchest) (p = 0.033), PSQI score (p < 0.001), and sleep quality domains for "cannot breathe comfortably" (p = 0.037) and "have pain" (p = 0.003). Binary logistic regression (chi-square = 37.457, p = 0.001) showed that the variables Δchest (p = 0.038, 95% CI: 1.05-6.07) and PSQI score (p = 0.048, 95% CI: 0.1-1.07) remained independent predictors of the swim distance groups. Girls had a lower percentage of predicted values for the maximal inspiratory pressure (p < 0.001), maximal expiratory pressure (p = 0.027), forced expiratory volume within the first second (p = 0.026), forced vital capacity (p = 0.008) and sleep quality domains for "cough or snore loudly" (p = 0.032) compared to boys. A regression analysis showed that the sleep quality score was explained by the six independent variables: respiratory muscle strength (t = 2.177, β = 0.164, p = 0.035), Δchest (t = -2.353, β = -0.17, p = 0.023), distance (t = -5.962, β = -0.475, p < 0.001), total body water (t = -7.466, β = -0.687, p < 0.001), lean body mass (t = -3.120, β = -0.434, p = 0.003), and handgrip (t = 7.752, β = 1.136, p < 0.001). Our findings demonstrate that sleep quality in adolescent swimmers is a multifactorial result of morphometric characteristics, strength and respiratory function.

Ultrawideband sub-pascal sensitivity piezopolymer detectors

Piezoelectric detectors are integral part of modern ultrasound imaging systems. Their utility has also been extended beyond the established methodologies into the emerging realm of hybrid optoacoustic imaging. Conventional piezoceramic detectors, however, struggle to combine high detection sensitivity with ultrawide bandwidth, both considered critical for attaining optimal optoacoustic imaging performance. Our research, both theoretical and empirical, unveils that damped piezopolymer detectors fabricated from PVDF-TrFE are markedly capable of achieving a synergistic blend between broad bandwidth and superb sensitivity. Experimental evaluations reflected an average sensitivity of 15.5 µV/Pa within a 1–10 MHz band for a 120 µm thick detector and 6.4 µV/Pa within a 1–30 MHz band for a 20 µm thick detector, thus outperforming conventional piezoelectric analogues. The resultant noise equivalent pressure (NEPs) values were 0.3 Pa and 1.2 Pa for the 20 µm and 120 µm detectors, respectively. Our findings herald a significant stride towards enhancing the efficacy of ultrawideband ultrasound and optoacoustic imaging systems.

EVALUATION OF ELABELA LEVELS IN OBESE INDIVIDUALS

Aim: Obesity is a condition that occurs as a result of excessive weight gain. Obesity is related with the high risk of several diseases like cardiovascular diseases and diabetes mellitus. Elabela is a peptide that has emerged recently and is known to affect food intake by binding to apelinergic receptors. This study aimed to investigate the serum levels of Elabela in obese and non-obese individuals. Material and methods: This study involved 24 people with obesity and 25 healthy adult people as control group. Height, weight, gender, age, waist-hip circumference, blood pressure of participants were recorded and routine blood tests were measured. Serum concentrations of Elabela were determined using enzyme-linked immunosorbent assay. Results: When comparing the obese group to the controls, no statistically significant differences were observed between the two groups in terms of diastolic blood pressure, blood urea nitrogen, creatinine, total cholesterol, low density lipoprotein cholesterol and C-reactive protein. Similarly, both groups did not differ statistically regarding Elabela levels. The obese group exhibited significantly elevated levels of body mass index, waist/hip ratio, systolic blood pressure values, glucose, aspartate aminotransferase, alanine aminotransferase, triglyceride, insulin, homeostatic model assessment for insulin resistance (HOMA-IR) compared to the control group. The obese group demonstrated a significantly lower level of high-density lipoprotein cholesterol in comparison to the control group. Conclusions: In this study, it was found that there was no relationship between Elabela levels and obesity. However, this issue needs to be supported by further studies to clarify.