Changes In Pressure Research Articles

Application of Deep Learning Classification Model for Regional Evaluation of Roof Pressure Support Evolution Effects Over Time in Coal Mining Face

Hydraulic support leg pressure serves as a crucial indicator for assessing work face support quality. Current evaluation methods for support quality primarily concentrate on static analyses-like inadequate initial support force, pressure overrun, and uneven bracket force-while neglecting dynamic column pressure changes. This paper introduces a model for assessing hydraulic support quality using deep learning techniques. Real-time data is preprocessed into a spatio-temporal pressure sub-matrix sample, which is then inputted into the model. This process assesses the support quality type and characterizes its dynamic evolution within the area. The model facilitates the identification of dynamic support quality effects in the working face area, aiding operators in making targeted adjustments to hydraulic support status. Experimental results revealed that the optimized LeNet-5 network-adjusting parameters like convolutional layer count, kernel size, and ReLU activation function-achieved the highest classification accuracy of 85.25% for support quality, surpassed other networks. Furthermore, the improved LeNet-5 network outperformed other networks in both F1 score and recall. Additionally, the improved LeNet-5 network achieved faster convergence to the optimal solution, accelerated training speed. This highlighted its advantages in evaluating the spatio-temporal support quality of hydraulic supports in smart mining operations.

Effects of intrarenal pelvic infusion of tumour necrosis factor-α and interleukin 1-β on reno-renal reflexes in anaesthetised rats.

Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves. In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1β (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin. The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1β infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1β, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1β, by almost 80% below vehicle, again without effect on either MAP or HR. The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1β. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response.

Design of smoke detection system using deep learning and sensor fusion with recursive feature elimination cross-validation

The fire safety system is an important component that controls material and immaterial losses. Fire disasters are generally indicated by the appearance of excess smoke and changes in temperature, pressure, and changes in other parameters in the environment. Conventional smoke sensors are limited in reading parameter changes around their environment, making them less effective in early fire detection. This study aims to design a smoke detection system as an early fire detection system, using sensor fusion based on deep learning using the recursive feature elimination method with cross-validation (RFECV) using a random forest classifier used to select optimal parameters from public datasets as the basis for determining the sensor to be used. Based on the RFECV optimal feature, a deep learning algorithm was performed and obtained an accuracy of 0.99, a precision of 0.99, a recall of 1.00, and an F1 score of 0.99, with a latency time of 34.02 μs, which is 71.76% times faster than the original model.

Research on Establishment of Digital-Twin System for Intelligent Control of Cutting Tools Sintering Process Driven by Data-Model Combination

In the manufacturing process of tungsten cemented carbide cutting tools, the changes in temperature, pressure and vacuum during the sintering process of the cutting tools can have a significant impact on the quality of the cutting tools. This effect is particularly significant in the vacuum sintering stage, so this paper focuses on cutting tools sintering in the vacuum stage. The cutting tools sintering process is carried out in a closed space in a sintering furnace with a complex internal structure. Therefore, it is extremely difficult to accurately predict the heating condition of the cutting tools in the furnace and monitor the sintering quality of the cutting tools. In this study, a digital twin system for the sintering process of cemented carbide cutting tools is proposed, which combines monitoring rolling data analysis and sintering quality prediction model. Firstly, the radiative thermodynamic model of cutting tools sintering temperature was established in this system. The model predicts the time-varying state of the heat distribution at any location in the furnace during the vacuum phase. Subsequently, based on the convolutional neural network, the mapping relationship between the sintering parameters and the grain size in the vacuum stage is constructed, and a dynamic evaluation model of cutting tools sintering quality is proposed. The model enables real-time prediction of sintering quality in the vacuum stage. The system realizes the prediction of the time-varying state of the sintering quality of the cutting tools. The digital twin system realizes the adaptive temperature control of the vacuum stage of cutting tools sintering based on the fuzzy control algorithm. The application of this system has increased the yield rate of cemented carbide cutting tools manufacturing to 98.9%. This breaks through the problem of timing modulation of cutting tools sintering quality in the vacuum stage of cutting tools sintering.

An assessment of model capability on rapid intensification prediction of tropical cyclones in the South China Sea

The absence of robust quantitative evaluation methods has led to insufficient knowledge of models capability on the rapid intensification (RI) prediction of tropical cyclones (TCs). In this study, we propose a method and define some indicators aiming to evaluate model capability on predicting RI in a more accurate manner. An assessment of model predictive capability on RI of TCs based on 10 years of operational forecasts has been conducted using different RI criteria. The Tropical Regional Atmosphere Model for the South China Sea (TRAMS) and the European Centre for Medium-Range Weather Forecasts (ECMWF) high resolution (HRES) operational forecasts were used. Analysis results revealed that the criterion of 6-hour sea level pressure (SLP) change is more appropriate to be used in RI operational forecast. The maximum lead time (MLT) of TRAMS and HRES was 72 and 78h, and the maximum deviation of RI occurrence time of TRAMS and HRES was 48h delay and 24h ahead, respectively. Overall results suggest that the model predictive capability of RI is currently limited, and both models have inadequate capability in providing sufficient heat and energy to support RI in the long run. A tendency of TRAMS to have a lag in RI occurrence time was also demonstrated due to an air-sea interaction lag resulting from the fixed skin sea surface temperature used. Results of the present study provide insights and could be the basis for future efforts on improving parametrization schemes for properly describing RI process of TCs.

Longitudinal trajectories of Alzheimer's disease CSF biomarkers and blood pressure in cognitively healthy subjects.

We examined whether hypertension (HTN) was associated with Alzheimer's disease-related biomarkers in cerebrospinal fluid (CSF) and how changes in blood pressure (BP) related to changes in CSF biomarkers over time. A longitudinal observation of cognitively healthy normotensive subjects (n=134, BP<140/90, withno antihypertensive medication), controlled HTN(n=36, BP<140/90, taking antihypertensive medication), and 35 subjects with uncontrolled HTN (BP ≥ 140/90). The follow-up range was 0.5to15.6 years. Total tau (T-tau) and phospho-tau181 (P-tau 181) increased in allbut controlled HTN subjects (group×timeinteraction: p<0.05 for both), but no significant Aβ42 changes were seen. SignificantBP reduction wasobserved in uncontrolled HTN, andit was related to increase in T-tau (p=0.001) and P-tau 181 (p<0.001). Longitudinal increases in T-tau and P-tau 181 were observed in most subjects; however, onlyuncontrolled HTN had both markers increase alongside BPreductions. We speculatecumulative vascular injury renders thebrain susceptible to relative hypoperfusion with BP reduction. Over the course of the study, participants with uncontrolled HTN at baseline showed greater accumulation of CSF total tau and phospho-tau181 (P-tau 181) than subjects with normal BP or with controlled HTN. In the group with uncontrolled HTN, increases in total tau and P-tau 181 coincided with reduction in BP. We believe this highlights the role of HTN in vascular injury and suggests decline in cerebral perfusion resulting in increased biomarker concentrations in CSF. Medication use was the main factor differentiating controlled from uncontrolled HTN, indicating that earlier treatment was beneficial for preventing accumulations of pathology.

Uniformly elevated future heat stress in China driven by spatially heterogeneous water vapor changes

The wet bulb temperature (Tw) has gained considerable attention as a crucial indicator of heat-related health risks. Here we report south-to-north spatially heterogeneous trends of Tw in China over 1979-2018. We find that actual water vapor pressure (Ea) changes play a dominant role in determining the different trend of Tw in southern and northern China, which is attributed to the faster warming of high-latitude regions of East Asia as a response to climate change. This warming effect regulates large-scale atmospheric features and leads to extended impacts of the South Asia high (SAH) and the western Pacific subtropical high (WPSH) over southern China and to suppressed moisture transport. Attribution analysis using climate model simulations confirms these findings. We further find that the entire eastern China, that accommodates 94% of the country’s population, is likely to experience widespread and uniform elevated thermal stress the end of this century. Our findings highlight the necessity for development of adaptation measures in eastern China to avoid adverse impacts of heat stress, suggesting similar implications for other regions as well.

Age-related changes of intraocular pressure in Dutch belted rabbits.

This study investigated intraocular pressure (IOP) in Dutch belted rabbits using two different tonometers, rebound tonometry (TonoVet Plus; TVP) and a Tonopen (Tono-Pen AVIA Vet; TPA). Post-pubescent male Dutch belted rabbits aged 36weeks (n = 10 animals) were used in the study. IOP measurements were conducted every 2weeks for 22weeks using TVP and TPA on both eyes of each rabbit. The average IOP measurements were compared by the paired Student's t-test. Pairwise Pearson's correlation coefficients and Bland-Altman statistics were used. The overall mean IOP measured with TPA was significantly higher than that with TVP (23.5 ± 4.9 vs. 21.8 ± 2.4mmHg for the right eyes; P = 0.045, and 23.0 ± 4.7 vs. 21.5 ± 2.4mmHg for the left eyes; P = 0.047). Both tonometers tended to show increased IOP readings with age, and positive correlations between IOP and age were observed with both TPA (r = 0.95, P < 0.001 for right eyes; r = 0.95, P < 0.001 for left eyes) and TVP (r = 0.91, P < 0.001 for right eyes; r = 0.64, P = 0.024 for left eyes). The average bias calculated by subtracting TPA from TVP was - 1.60(95% confidence intervals - 1.927, - 1.281)mmHg. IOP in post-pubescent Dutch belted rabbits tended to increase with age throughout the 22week study.

Patent Ductus Arteriosus—To Close or Not to Close?

(N Engl J Med. 2024;390(4):370–371) Patent ductus arteriosus (PDA) is the most frequently encountered cardiac condition in neonates. The ductus arteriosus plays the crucial role of allowing blood to bypass the lungs in the fetal stage. At birth, with the initiation of lung function, changes in pressure and oxygen lead to the closure of the ductus arteriosus, redirecting blood flow through the newly operational pulmonary circulation. When a baby is born too early, birth is not enough to cause the duct to close, resulting in PDA.

Influence of audiovisual distraction on the feeling of stress, analgesic sedation and patient satisfaction during electrophysiological ablation procedures on the heart

Abstract Background Distraction using audiovisual stimuli has mostly been researched in a paediatric population with the results showing an inhibiting effect on stress and anxiety as well as the subjective perception of pain. Purpose We designed a study to test if audiovisual distraction may reduce the level of sedatives and analgesics by reducing anxiety and stress during electrophysiological intervention (EP). Methods We conducted a clinical intervention pilot study that was carried out in a randomized controlled manner. Consecutive 70 patients undergoing EP with subsequent ablation were randomized 1:1 to control (CTL) or intervention group (AVD). In addition to standardized sedation, all patients in AVD group received audiovisual glasses. Feeling of fear and stress was assessed through blood pressure changes. The patient satisfaction was assessed with Client Satisfaction Questionnaire, ZUF-8. Numeric scale (NRS) was used to quantify the perceived pain during the procedure. The difference between the subjective estimated duration of the procedure and the actual duration of the procedure was compared. Results The study included predominantly male patients (58.6%) with a mean age of 56 years. Technical aptitude was well balanced between both groups with the majority of patients in both groups owning a smartphone or a tablet (86.1% vs 85.7% for CTL and AVD respectively, p=0.92), and majority of patients in both groups using a computer, laptop or tablet on a weekly basis (58% vs 57.1% for CTL and AVD group respectively, p=0.97). The baseline feelings of anxiety were well balanced within both groups (Figure 1). Our analysis revealed no significant difference between the mean blood pressure values of the CTL and AVD groups (systolic: 135 vs. 141 mmHg; p = 0.32; diastolic: 74 vs. 72 mmHg; p = 0.45). Patient satisfaction score was comparable in both groups (26.5 vs. 26.8 points, p = 0.36). Average response for perceived pain using NRS scale as well as perceived procedure duration was similar between the groups (Figure 2). AVD group required a lower dose of Midazolam than CTL group (0.005 mg/kg/h vs 0.007 mg/kg/h, p = 0.07). Majority of patients (31.4%) in AVD group stated: "The audiovisual glasses made me feel distracted at times." 10% of the AVD patients stated: "The audiovisual glasses made me feel completely distracted and more relaxed." Conclusion The use of audiovisual glasses has no influence on the patients’ feelings of anxiety and stress during EP. The use of audiovisual glasses can temporarily induce distraction during EP, while they do not seem to be sufficient in reducing pain intensity during ablation therapy. Patients undergoing EP do not seem to be the target patient group for AVD use.

LVSP and LBBP result in similar or improved LV synchrony and hemodynamics compared to biventricular pacing

Abstract Background The effect of left ventricular myocardial septal pacing (LVSP) and left bundle branch pacing (LBBP) on ventricular synchrony and LV hemodynamics is poorly understood in unselected cardiac resynchronization therapy (CRT) patients. Aim To investigate the impact of LBBP and LVSP on ultra-high-frequency ECG (UHF-ECG) ventricular synchrony and hemodynamics in CRT patients. Methods In consecutive CRT patients with LBBB, ventricular synchrony was assessed using UHF-ECG. LV hemodynamics was assessed using invasive systolic blood pressure measurement during multiple transitions between LBBP, LVSP, and biventricular pacing (BVP). LV synchrony was assessed by LV lateral wall delay (LVLWd) from the first to the last from V5-V8 activations. Hemodynamic effects were expressed as relative changes in systolic blood pressure. Results Thirty patients with an LVEF of 29 ± 6% and mean QRSd of 169 ± 24 ms were included. Twenty had non-ischemic cardiomyopathy. QRSd during BVP, LVSP, and LBBP was the same, but LBBP provided shorter LVLWd than BVP (-9 ms (-16; -4), p = 0.004); the difference between LVSP and BVP was not significant (-4 ms (-10;2), p = 0.2). LBBP was associated with higher systolic blood pressure than BVP (4% (2; 5) p &amp;lt; 0.001), while LVSP was not (1% (1; 2), p = 0.1. LV hemodynamic improvements during LBBP and LVSP vs. BVP were more pronounced in non-ischemic than ischemic patients. Conclusion The differences in ventricular synchrony between LBBP, LVSP, and BVP were demonstrated using UHF-ECG but not QRSd. LBBP, but not LVSP, was associated with better LV synchrony and hemodynamics than BVP.Local activation times in V1–V8Ventricular dyssynchrony and hemodynamic

Acute hemodynamic effects of the Marshall-Plan ablation on left and right atrial pressure: does 'respecting atrial physiology' prevent stiff left atria? A retrospective single- center analysis

Abstract Introduction Stiff left atrium (STILA)-syndrome is a relevant concern after extensive ablation in the left atrium (LA) e.g. in persistent atrial fibrillation (AF). STILA often causes disabling heart failure symptoms worse than the initial arrhythmia symptoms. Therefore preventing adverse ablation-induced hemodynamic effects is of utmost concern. Methods This single-center study retrospectively analyzed data from 89 consecutive patients who underwent biatrial ablation for AF following the Marshall-Plan between February 2022 and November 2023. The procedures included ablation of the CTI and PVI where necessary followed by ablation of a LA roof line and ablation of the lateral mitral isthmus after previously performed ethanol ablation of the vein of Marshall. This lesion set is considered to maintain physiological activation of the LA. This study evaluates acute hemodynamic changes following the Marshall-Plan. Invasive hemodynamic measurements of mean left and right atrial pressure, as well as A- and V-waves were performed in all patients before and after the ablation. We assessed the acute changes of atrial hemodynamics in these procedures. Continuous data are given as mean ± standard deviation, categorical data are expressed as number and percentages. Differences between groups were determined by Student’s t-test, chisquare-test, and Fisher’s exact test using SPSS software. A p-value of &amp;lt;0.05 was deemed significant. Results The patients' mean age was 70.1 ± 7.5 years and 39.0% were female. Mean BMI was 28.9 ± 5.2 kg/m². Procedures were performed under general anesthesia (with a PEEP of 5.5cmH2O (2-10 cmH2O)) and took 181 minutes on average. Left atrial mean pressure averaged at 15.7mmHg before the procedure. The overall average change of left atrial mean pressure was +1,8mmHg. The average change in left atrial A- and V-Wave amounted to -1.9mmHg and -0.9mmHg respectively. The pre-procedural average right atrial mean pressure was 12.1mmHg. Right atrial mean pressure inclined by +1.6mmHg. The average change in right atrial A- and V-Wave was +0.6mmHg and +1.1mmHg respectively. The i.v. administered volume averaged 1900 ± 285ml. 3.3% of patients showed an increase of mean LA-pressure &amp;gt;9mmHg. Those patients tended to be older (74.3years), were all male (100%) and had a higher BMI (31.5 kg/m²) as well as higher amount of i.v. administered volume (2333ml) and a longer procedure (213min). Discussion Complex and extensive biatrial ablation following the Marshall-Plan does not lead to acute significant increases in left or right atrial pressures. The administered i.v. volume might explain the slight increases observed. In our observation, the rate of significant increases in LA-pressure is low. This suggests that disrupting the (left) atrial activation pattern might play a role in the development of diastolic dysfunction and thereby STILA-syndrome. Respecting atrial physiology may be beneficial for preventing adverse hemodyamic changes after ablation.

The origin of intraluminal pressure waves in gastrointestinal tract.

The gastrointestinal (GI) peristalsis is an involuntary wave-like contraction of the GI wall that helps to propagate food along the tract. Many GI diseases, e.g., gastroparesis, are known to cause motility disorders in which the physiological contractile patterns of the wall get disrupted. Therefore, to understand the pathophysiology of these diseases, it is necessary to understand the mechanism of GI motility. We present a coupled electromechanical model to describe the mechanism of GI motility and the transduction pathway of cellular electrical activities into mechanical deformation and the generation of intraluminal pressure (IP) waves in the GI tract. The proposed model consolidates a smooth muscle cell (SMC) model, an actin-myosin interaction model, a hyperelastic constitutive model, and a Windkessel model to construct a coupled model that can describe the origin of peristaltic contractions in the intestine. The key input to the model is external electrical stimuli, which are converted into mechanical contractile waves in the wall. The model recreated experimental observations efficiently and was able to establish a relationship between change in luminal volume and pressure with the compliance of the GI wall and the peripheral resistance to bolus flow. The proposed model will help us understand the GI tract's function in physiological and pathophysiological conditions.

Prevalence of non pulmonary vein triggers and pulmonary pressure change in atrial fibrillation ablation for cardiac amyloidosis patients

Abstract Background Cardiac amyloidosis (CA) has been associated with an increased risk of atrial arrhythmias and high risk to develop pulmonary hypertension due to infiltration of the amyloid protein in the atrial wall. Though non-PV triggers are commonly seen in left atrium, they are also seen in the right side of the heart, so identifying them at the time of ablation is essential. Objective The study evaluates the prevalence of non-PV triggers during catheter ablation in atrial fibrillation (AF) patients affected by cardiac amyloidosis and how restoration of sinus rhythm affects pulmonary pressures. Methods This is a study including 74 consecutive patients with an established diagnosis of amyloidosis ATTR diagnosed with cardiac MRI or myocardial biopsy that underwent their first AF catheter ablation. All have a transthoracic echocardiogram before ablation. They underwent pulmonary vein (PV) isolation + isolation of left atrial posterior wall and superior vena cava. Additionally, extrapulmonary triggers, which are defined as ectopic triggers originating from sites other than PVs including left atrial appendage (LAA), coronary sinus (CS), interatrial septum, crista terminalis, mitral valve anulus were identified. Post procedure, patients were followed up routinely with ECG during office visits, echocardiogram, 7-day Holter monitor and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Student’s t-test was used to compare pulmonary pressure between the groups. Results Isoproterenol-challenge revealed non-PV triggers in 51 (68.9%) patients. These triggers were mostly mapped to LAA (39, 52.7%), CS (30, 40,5%), and crista terminalis (35, 47.3%). Besides, ectopic beats were seen originating from inter-atrial septum (19, 25.6%), mitral valve annulus (10, 13.5%). More than one trigger was found in (68%) patients. At 1-year after the ablation, 65 (87.8%) were arrhythmia-free off antiarrhythmic drugs. Moreover, in patients who maintained sinus rhythm post-ablation, there was either a non progression or a reduction in pulmonary pressures (PAPm before ablation: 44.8 ± 8.9 mmHg vs PAPm after ablation 45.1 ± 11.1 mmHg, P value =0.87). Conversely, those experiencing arrhythmic recurrences demonstrated an increase in pulmonary pressures (PAPm before ablation: 41.9 ± 7.7 mmHg vs PAPm after ablation 47.8 ± 10.2 mmHg, P value =0.019). Fig.1 Conclusion Our findings suggest that non-PV triggers are highly prevalent in cardiac amyloidosis AF patients including a high rate crista terminalis firing. Notably, restoration of sinus rhythm post-ablation was linked to stable or reduced pulmonary arterial pressures, whereas patients with arrhythmic recurrences experienced a significant increase.

#730 Dialysis-induced changes in systolic, diastolic, and pulse pressure in maintenance hemodialysis patients

Abstract Background and Aims Hemodialysis (HD) therapy has a strong impact on cardiovascular function in both the short and long term. In the short term, the dialysis-induced changes in blood volume directly affect the arterial blood pressure (BP), frequently leading to intradialytic hypotension or hypertension, both associated with adverse outcomes. The aim of this study was to investigate the dialysis-induced changes in systolic (SBP), diastolic (DBP), and pulse pressure (PP) in maintenance HD patients and to assess their relationship with pre-HD BP. Methods 197 maintenance HD patients were studied during the middle dialysis session of the week. The mean pre-dialysis fluid overload was 2.0 ± 1.6 L (calculated as the difference between the pre-dialysis body weight and the target weight). All HD sessions lasted approximately 4 h and were performed using mainly low-flux dialyzers. SBP and DBP were measured pre-HD and post-HD using a sphygmomanometer. PP was calculated as SBP minus DBP. The patients were divided into two groups: A) patients with an intradialytic decline in SBP (∆SBP &amp;lt;0), and B) patients with an increase or no change in SBP during HD (∆SBP ≥0). Paired data were compared using the Student's t-test. Correlations between variables were assessed using Spearman's rho (ρ). Results During HD, SBP decreased in 120 (61%) patients (in 20 cases by more than 30 mmHg), remained unchanged in 11 (6%) patients, and increased in 66 (33%) patients (in 13 cases by more than 20 mmHg). DBP decreased in 94 (48%) patients, remained unchanged in 46 (23%) patients, and increased in 57 (29%) patients. In 76 (39%) patients both SBP and DBP decreased, whereas in 33 (17%) patients both SBP and DBP increased. In group A (n = 120), SBP, DBP, and PP decreased by 21 ± 16 mmHg (P &amp;lt; 0.001), 8 ± 11 mmHg (P &amp;lt; 0.001), and 13 ± 14 mm Hg (P &amp;lt; 0.001), respectively. In group B (n = 77), SBP, DBP, and PP increased by 12 ± 10 mmHg (P &amp;lt; 0.001), 4 ± 11 mmHg (P &amp;lt; 0.001), and 8 ± 13 mmHg (P &amp;lt; 0.001), respectively. Pre-HD SBP was 144 ± 23 mmHg in group A and 128 ± 25 mmHg in group B (P &amp;lt; 0.001). Pre-HD DBP was 80 ± 15 mmHg in group A and 68 ± 11 mmHg in group B (P &amp;lt; 0.001). In all patients combined, ∆SBP was similarly correlated with pre-HD SBP and pre-HD DBP (ρ = −0.42 in both cases, P &amp;lt; 0.001), whereas ∆DBP was more strongly correlated with pre-HD DBP (ρ = −0.52, P &amp;lt; 0.001) than with pre-HD SBP (ρ = −0.22, P &amp;lt; 0.01). ∆SBP was correlated with ∆DBP (ρ = 0.55, P &amp;lt; 0.001) and highly correlated with ∆PP (ρ = 0.78, P &amp;lt; 0.001). According to linear regression, SBP tended to increase during HD in patients with pre-HD SBP &amp;lt;118 mmHg (Fig. 1A), whereas DBP tended to increase in patients with pre-HD DBP &amp;lt;68 mmHg (Fig. 1B). Conclusions Patients with dialysis-induced decline in SBP (group A) had a significantly higher pre-HD BP (both SBP and DBP) compared with patients with an increasing or stable SBP (group B). This suggests that a high decline in SBP during HD appears to be more likely in patients with elevated pre-HD BP and that HD appears to have a pressure-normalizing effect in such patients. Similarly, a dialysis-induced increase in SBP or DBP appears to be more likely in patients with low values of pre-HD SBP or DBP, respectively.

Silver nanowires/waterborne polyurethane composite film based piezoresistive pressure sensor for ultrasensitive human motion monitoring

Flexible piezoresistive pressure sensors are gaining significant attention, particularly in the realm of flexible wearable electronic skin. Here, a flexible piezoresistive pressure sensor was developed with a broad sensing range and high sensitivity. We achieved this by curing polydimethylsiloxane (PDMS) on sandpaper, creating a PDMS film as the template with a micro-protrusion structure. The core sensing layer was formed using a composite of silver nanowires (AgNWs) and waterborne polyurethane (WPU) with a similar micro-protrusion structure. The sensor stands out with its exceptional sensitivity, showing a value of 1.04 × 106 kPa−1 with a wide linear range from 0 to 27 kPa. It also boasts a swift response and recovery time of 160 ms, coupled with a low detection threshold of 17 Pa. Even after undergoing more than 1000 cycles, the sensor continues to deliver stable performance. The flexible piezoresistive pressure sensor based on AgNWs/WPU composite film (AWCF) can detect small pressure changes such as pulse, swallowing, etc, which indicates that the sensor has great application potential in monitoring human movement and flexible wearable electronic skin.

#2175 Sodium-glucose cotransporter 2 (SGLT2) inhibitors-induced erythropoiesis and cardiovascular events in chronic kidney patients

Abstract Background and Aims Prior research has established that in chronic kidney disease (CKD), elevating hemoglobin (Hb) levels above 11.5 g/dl correlates with heightened thromboembolic event risks and increased mortality. Similar findings are seen in heart failure patients with Hb levels exceeding 13 g/dl, following treatment with erythropoiesis-stimulating agents. Sodium-glucose cotransporter 2 (SGLT2) inhibitors consistently raise Hb levels in CKD patients, both anemic and non-anemic. This study aims to evaluate the consequences of Hb level elevation due to SGLT2 inhibitors beyond the safe threshold in CKD patients and to investigate its association with cardiovascular (CV) events. Method A retrospective observational study was conducted from January 2016 to December 2021, focusing on CKD patients treated with SGLT2 inhibitors. Patients receiving erythropoiesis-stimulating agents or undergoing renal replacement therapy were excluded. We assessed the impact of Hb level changes on atheroembolic events, blood pressure variations, and mortality, while considering demographic data, red blood cell parameters, and renal function indicators. Patients receiving iron treatment were excluded to ensure accurate ferrokinetic parameter assessment. Results The study included 79 CKD patients, predominantly male (76%) and primarily with type 2 diabetes mellitus (T2DM) as the CKD cause (67%). Average follow-up post-SGLT2 inhibitor initiation was 3.5 years (SD 1.4, 0.7-6.7 years). Hb levels increased mainly in the first six months of treatment, with an average increase of 0.7 g/dl/year from baseline (p &amp;lt; 0.01). Ferritin levels slightly decreased (p 0.002), while the transferrin saturation index remained stable. Baseline estimated glomerular filtration rate (eGFR) did not influence Hb increase. Various responses to SGLT2 inhibitors were noted based on baseline Hb levels. No significant association was found between elevated Hb levels (&amp;gt;16.0 g/dl) and increased atheroembolic events, mortality, or blood pressure changes. However, patients with Hb levels &amp;gt;13.0 g/dl experienced more CV events compared to those maintaining Hb ≤13.0 g/dl, though not statistically significant (0% vs 17.5%: p 0.30). Conclusion SGLT2 inhibitor treatment led to a significant Hb increase unless baseline levels were above 16.0 g/dl. Importantly, elevating Hb levels above 13.0 g/dl appears to be linked with a higher incidence of cardiovascular (CV) events, suggesting a potential risk associated with such an increase in Hb levels in this patient population. This finding underscores the necessity for further research to confirm this correlation and to delineate the safe therapeutic window for Hb levels in CKD patients treated with SGLT2 inhibitors.

#336 Early detection of vascular access complication in pediatric CKD hemodialysis patients

Abstract Background and Aims Vascular access (VA) dysfunction is a major clinical complication in the hemodialysis (HD) population and has a direct effect on dialysis outcome. Where in patients undergoing HD, neointimal hyperplasia results in vascular stenosis and subsequent thrombosis, which lead to vascular access failure. Interleukin-10 (IL-10), hs CRP, and tumor necrosis factor- (TNF–α) are inflammatory markers which are proved to be involved in the process neointimal hyperplasia &amp; subsequent complications. We aimed to evaluate the value of these inflammatory markers in early detection of arterio-venous fistula (AVF) failure, in pediatric patients on regular HD, together with the clinical &amp; radiological diagnoses, for proper intervention for correcting AVF failure according to guidelines. Method It was an prospective cohort study, where we included 59 pediatric chronic kidney disease patients’ stage 5, on regular HD (CKD5d), who were following up regularly with us for 1 year. Patients with nonfunctioning AVFs due to complications as thrombus occluding fistula, infections, or large aneurysm, were excluded from the beginning of the study. Monitoring of VA by pre-cannulation physical examination was performed to detect the physical signs of dysfunction, at least once per month according to KDOQI guidelines. Venous pressure (VP) and trans-membrane pressure (TMP) were recorded at each HD session, to detect any abnormalities and to record the pressure changes with the appearance of any AVF complications. Doppler ultrasound (DUS) was performed routinely every 3 months for all HD patients, &amp; at the time of development AVF complications. Blood samples for measuring IL10, TNF, hs CRP were collected from the patients every 2 weeks for 12 months, prior to HD sessions, where we included the most recent samples prior to, and at the time of development complications, which were clinically and radiologically confirmed. Results The mean (±SD) age of our patients was 13.97 (±2.65) years, where we had 39 (56.5%) males, and 30 (43.5%) females, with a median (IQR) HD duration of 4.0 (5.0) years. On assessing the AVF complications, 33 patients (55.9%) had experienced complications, where thrombosis was the most common reported one (17 patients, 28.8%), followed by aneurysm formation in 14 patients (23.7%), while 6 patients (10%) had stenosed AVF, early VA failure in 2 patients (3.4%),1 patient (1.7%) had pseudoaneurysm, and another patient (1.7%) had perivascular hematoma. Mean serum levels of Hs-CRP, TNF-α, IL-10 were elevated at timing of early development of complication, in comparison to their baseline levels, meanwhile serum IL10, and TNF alpha were significantly higher among patients who developed AVF stenosis. The baseline hs-CRP had related positively with AVF diameter at the time of the development of the complications. Conclusion The inflammatory markers have no clinically applied role in early detection of AVF abnormalities, therefore, physical examination and DUS are deemed sufficient.

Augmentation of nitric oxide deficient hypertension by high salt diet is associated with reduced TNF-α receptor type 1 expression in the kidneys.

High salt (HS) intake induces an augmented hypertensive response to nitric oxide (NO) inhibition, though it causes minimal changes in blood pressure (BP) in NO intact condition. The cause of such augmentation is not known. HS induces tumor necrosis factor-alpha (TNFα) production that causes natriuresis via activation of its' receptor type 1 (TNFR1). We hypothesized that NO deficiency reduces renal TNFR1 activity, leading to enhanced sodium retention and hypertension. We examined the changes in renal TNFR1 protein expression (Immunohistochemistry analyses) after HS (4% NaCl) intake in wild-type mice (WT, C57BL6) treated with a NO synthase (NOS) inhibitor, nitro-L-arginine methyl ester (L-NAME; 0.05mg/min/g; osmotic mini-pump), as well as in endothelial NOS knockout mice (eNOSKO) and compared the responses in WT mice with normal salt (NS; 0.3% NaCl) intake. BP was measured with tail-cuff plethysmography and 24-hour urine collections were made using metabolic cages. HS alone did not alter mean BP in untreated mice (76±3 to 77±1 mmHg) but induced an augmented response in L-NAME treated (106±1 vs 97±2 mmHg) and in eNOSKO (107±2 vs 89±3 mmHg) mice. The percentage area of TNFR1 expression in renal tissue was higher in WT+HS (4.1+0.5%) than in WT+NS mice (2.7±0.6%). However, TNFR1 expression was significantly lower in L-NAME treated WT+NS (0.9±0.1%) and in eNOSKO+NS (1.4±0.2%) than in both WT+NS and WT+HS mice. These data indicate that TNFR1 activity is downregulated in NO deficient conditions, which facilitates salt retention leading to augmented hypertension during HS intake.

#2570 Non-invasive blood pressure monitoring in dialysis patients using pulse wave velocity

Abstract Background and Aims Dialysis patients are at high risk of circulatory dysregulation and hypotension during treatment. Intradialytic hypotension (IDH) is a potentially life-threatening complication. The main causes are high ultrafiltration volumes and high ultrafiltration rates when patients tend to gain a lot of weight between dialysis treatments. A lack of patient compliance with regard to drinking volumes and a lack of residual diuresis are risk factors for this. Close circulatory monitoring and therapy settings to avoid absolute or relatively high UF rates to prevent IDH are frequently used. These are primarily the frequent non-invasive measurement of blood pressure using cuffs, the measurement of relative blood volume and the adjustment of ultrafiltration rates to these values. Prophylactically, the dialysis time can be extended, ultrafiltration profiles or ultrafiltration breaks can be planned, the dialysate temperature can be lowered and the composition of the dialysate can be adjusted. Despite all attempts, however, the incidence of IDH in everyday clinical practice is too high. The non-invasive measurements with cuffs are not carried out frequently enough, the measurement of the relative blood volume only covers a partial range, sudden changes in vascular tension or cardiac output are not recorded. Method The pulse wave velocity (PWV) is a well-known parameter for describing the propagation of the pressure wave after ejection of the heart beat volume in the arteries. The PWV is dependent on blood pressure, vessel wall tension and cardiac output. Changes in blood pressure can therefore be recognised by measuring the PWV. With the help of a measuring device (PESAS) for the ECG signal and peripheral pulse plethysmography, PWV can be measured non-invasively, continuously, for every heartbeat and, above all, hardly noticed by the patient. The PESAS allows the time-synchronised measurement of ECG and peripheral plethysmography curves and thus the determination of PWV. It is an experimental device. We would like to present a study showing the use of a measuring device (PESAS) in 15 prevalent dialysis patients for the detection of IDH. All study participants were examined during 3 dialysis treatments. Results The measurement of PWV in chronic dialysis patients during treatment is technically feasible. The measurement is tolerated by the patients. Changes in PWV could be detected in the patients during the course of dialysis; these were also dependent on the ultrafiltration rates. Individual patient reactions to volume withdrawal varied, with both increases and decreases in PWV being demonstrated. An acute change in PWV was usually associated with a drop in blood pressure. Continuous measurement allowed IDH events to be detected earlier than intermittent blood pressure measurement with cuffs. Sudden drops in blood pressure could be detected better and earlier with the PESAS system than by measuring the relative blood volume. Conclusion The PESAS system is suitable for monitoring dialysis patients to prevent IDH. Further adjustments and optimisation of the evaluation algorithms are necessary.