Pressure Response Research Articles

Role of Ciliary Neurotrophic Factor in Angiotensin II-Induced Hypertension.

Ciliary neurotrophic factor (CNTF), mainly known for its neuroprotective properties, belongs to the IL-6 (interleukin-6) cytokine family. In contrast to IL-6, the effects of CNTF on the vasculature have not been explored. Here, we examined the role of CNTF in AngII (angiotensin II)-induced hypertension. Hypertension was chronically induced with AngII (1000 ng/kg per minute, osmotic mini-pumps, 14 days) in CNTF-knockout and wild-type mice (with or without nephrectomy and 1% NaCl drinking water). Blood pressure was measured by tail-cuff and radiotelemetry. Effects of CNTF on vascular function and the JAK2/STAT3 pathway were measured in vivo, in the isolated perfused kidney, and in mouse and human vascular smooth muscle cells. At baseline, systolic blood pressure was similar between both groups. During AngII infusion, blood pressure increase was significantly attenuated and hypertensive heart and kidney damage was significantly attenuated in CNTF-knockout compared with wild-type mice. Accordingly, renal pressor response to AngII but not KCl or phenylephrine was significantly decreased in CNTF-knockout compared with wild-type mice. Acute CNTF (5 µmol/L) administration nearly restored the AngII-dependent renal pressor response. Chronic CNTF treatment in CNTF-knockout mice increased blood pressure response to AngII to levels observed in wild-type mice. CNTF augments AngII-induced activation of the JAK2/STAT3 pathway in vitro in vascular smooth muscle cells. The significance of this interaction was shown, as the increase in renal pressor response by CNTF was abolished by JAK2/STAT3 inhibitors. Our results demonstrate a major impact of CNTF on blood pressure regulation by modulating AngII-induced pressor response via a JAK2/STAT3-dependent mechanism and indicate that CNTF is an important regulatory cytokine in hypertension.

Alteplase Purge Solution for Impella 5.5 Ventricular Assist Device Purge System Occlusion: Case Report and Review of the Literature.

The use of an alteplase (Activase) purge solution to address Impella ventricular assist device "thrombosis" or "purge system occlusion" has been mainly documented with earlier generation Impella devices (CP, 2.5, 5.0). Here, we report the use of an alteplase purge solution to manage Impella 5.5 purge system occlusion in a 31-year-old male admitted to the cardiac care unit in cardiogenic shock and listed for a heart transplant. Throughout the purge system occlusion, the patient demonstrated hemodynamic stability and overall pump flow and cardiac output were preserved. Initially, there was a lack of response in purge flow and pressure observed at the lower concentration of alteplase purge solution (0.04 mg/ml), yet after using the alteplase 4 mg/50 ml purge (0.08 mg/ml) solution concentration, a response was seen. No bleeding or hemodynamic complications were observed. In addition, a suggested management workflow and review of the case reports and case series published to date regarding Impella purge system occlusion is included in this article.

Systolic blood pressure response during exercise testing in symptomatic severe aortic stenosis

AimsExercise testing remains underused in patients with aortic stenosis (AS), partly due to concerns about an exercise-induced drop in systolic blood pressure (SBP). We aimed to study the SBP response...

A Tribo/Piezoelectric Nanogenerator Based on Bio-MOFs for Energy Harvesting and Antibacterial Wearable Device.

New types of metal-organic framework (MOF) materials have great potential in solving the current global dilemma on energy, environment, and medical care. Herein, based on two kinds of biomolecule-MOFs (Bio-MOFs) with favorable biocompatibility and degradation-reconstruction characteristics, we have established a self-powered muti-functional device to achieve an efficient and broad-spectrum environmental energy collection and biomedical applications. Combining Zn(II) and carnosine-based Zn-Car_MOF possessing a high piezoelectric response (d33 = 11.17 pm V-1) with patterned polydimethylsiloxane (PDMS) film, a tribo-piezoelectric hybrid nanogenerator (TPHG) is constructed with a synergy output of triboelectric and piezoelectric effects. The Zn-Car_TPHG demonstrates a high output performance (131V at 100kPa) and a wide range of pressure response (1Pa-100kPa), possessing applications in environmental energy collection and biomedical sensors. To expand the application of the wearable device, a conductive hexagonal prism MOF (Cu3(2,3,6,7,10,11-hexahydroxytriphenylene)2 (Cu-HHTP)) is synthesized and employed to load thymol (Thy). Cooperating with Zn-Car_TPHG, the resulting Cu-HHTP/Thy can achieve an efficient self-powered ROS (singlet oxygen (1O2) and hydroxyl radical (·OH)) generation and drug synergistic broad-spectrum sterilization effect (efficiency ≥ 98%). In a word, the flexible wearable device based on the muti-functional Bio-MOFs is sustainable and environmentally friendly, possessing wide application potential in fields of environmental energy collection, biosensors, and self-powered antibacterial.

Two-week Paramedic Hospital Training Augments Blood Pressure Response to Isometric Handgrip Exercise in Healthy Young Men.

Persistent stressful situations can have detrimental cardiovascular effects; however, effects on the blood pressure (BP) response to exercise have not been fully examined. This study investigated the impact of a 2-week stressful situation on the exercise pressor response. Eight healthy male university paramedic trainees underwent a 2-week paramedic hospital training and a control period study. Pre- and post-intervention, BP responses to the exercise test (2-min submaximal isometric handgrip [IHG] exercise followed by post-exercise muscle ischemia [PEMI]) and cold pressure test (CPT) were assessed. A stress biomarker, salivary alpha-amylase (sAA) activity, significantly increased after hospital training (Pre: 8.8 ± 4.6; Post: 15.5 ± 7.3 kU/L; P = 0.036), whereas no significant changes were observed in the control period (Pre: 11.3 ± 3.6; Post: 10.4 ± 4.5 kU/L). Although no significant trial (hospital training vs. control)-by-intervention (pre- vs. post-2-week period) interactions were detected in the mean arterial pressure (MAP) response to PEMI or CPT, a significant interaction in the MAP response to IHG exercise was noted (Δ48.9 ± 11.2 to Δ55.5 ± 9.1 mmHg, hospital training; Δ53.2 ± 14.1 to Δ51.2 ± 11.9 mmHg, control; P = 0.035). Consequently, changes in the sAA and MAP pre-intervention to post-intervention showed a significant correlation (τ = 0.397, P = 0.036). Results showed that stressful paramedic hospital training augmented BP response to IHG exercise. This suggests that prolonged stressful situations increase pressor response to exercise, particularly in cases involving healthy young men.

Loneliness mediates the association between trait social anxiety and cardiovascular reactivity to acute psychological stress.

The primary aims of the current study are (1) to examine the association between trait social anxiety and cardiovascular reactivity to acute psychological stress, and (2) to identify if loneliness significantly mediates the association between trait social anxiety and cardiovascular reactivity. A sample of 658 participants completed a cardiovascular reactivity protocol consisting of a resting baseline and stressor phase (mental arithmetic and Stroop), with systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) monitored throughout. Participants also completed self-reported measures assessing social anxiety and loneliness. Social anxiety was associated with increased self-reported stress. However, no significant associations between social anxiety and measures of cardiovascular reactivity were observed in regression analyses. Loneliness was significantly associated with lower SBP and DBP reactivity. Additionally, loneliness significantly mediated the association between trait social anxiety and both SBP reactivity and DBP reactivity. Here, trait social anxiety predicted greater levels of loneliness, which in turn was associated with diminished cardiovascular reactivity. No significant associations emerged for HR reactivity. These blunted blood pressure responses to acute stress may indicate a potential mechanism leading to adverse prospective health outcomes.

The associations between cardiovascular and pain responses to a cold pressor test differ between males and females.

Nociceptors contribute to the cardiovascular responses during a cold pressor test (CPT). While these responses are lower in females, data suggest that they perceive the CPT as more painful. Thus, we examined sex differences in associations between pain and cardiovascular responses to a CPT (Aim 1) as well as differences between females using (OC), and not using (NC), an oral contraceptive (Aim 2). 25 males (23 ± 5years) and 25 females (21 ± 3years; 11OC and 14NC) were studied. Cardiovascular data and pain levels (0-10 scale) were recorded at baseline then during a two-minute CPT; changes from baseline to peak response were analyzed. Systolic blood pressure (SBP, p = 0.57), mean arterial pressure (MAP, p = 0.22), heart rate (HR, p = 0.58), and pain (p = 0.71) responses did not differ between sexes; diastolic blood pressure (DBP) increased more in males (17 ± 8 vs. 13 ± 6mmHg, p < 0.05). Pain was associated with HR in males (r = 0.42, p < 0.05) but notfemales (r = -0.16, p = 0.44); no other associations were observed in either sex (p = 0.48-0.92). SBP (27 ± 12 vs. 15 ± 6mmHg), DBP (16 ± 6 vs. 9 ± 5mmHg), MAP (20 ± 7 vs. 14 ± 5mmHg), and HR (8 ± 5 vs. 2 ± 5beats/min) were greater in NC than OC (p < 0.05 for all); pain was similar (p = 0.38). In NC, pain was associated with DBP (r = 0.65, p = 0.01)and MAP (r = 0.65, p = 0.01),but not HR (r = -0.43, p = 0.13), and tended to be associated with SBP (r = 0.46, p = 0.09). In OC, pain was inversely associated with SBP (r = -0.62, p < 0.05) but no other outcome (p = 0.40-0.65). We report a sexual dimorphism in the HR-pain association during a CPT and underscore the impact of oral contraceptives.

Phytic Acid-Induced Gradient Hydrogels for Highly Sensitive and Broad Range Pressure Sensing.

Ionic conductive hydrogels have emerged as an excellent option for constructing dielectric layers of interfacial iontronic sensors. Among these, gradient ionic hydrogels, due to the intrinsic gradient elastic modulus, can achieve a wide range of pressure responses. However, the fabrication of gradient hydrogels with optimal mechanical and sensing properties remains a challenge. In this study, it is discovered first that phytic acid (PA) interacts in remarkably distinct manners (i.e., plasticizing effects and phase separation) with different polymers (i.e., polyacrylamide and polyacrylic acid). This distinctive PA-polymer interacting mechanism is innovatively utilized to construct a modulus gradient ionic hydrogel through a simple precursor solution infiltration approach. The gradient hydrogel-based flexible pressure sensor not only achieves a high sensitivity (9.00kPa-1, <15kPa) and a broad sensing range (from ≈3.7Pa to 1.2MPa) simultaneously, but also exhibits superior low pressure sensing performance. It successfully recognizes the subtle pressure due to acoustic waves and airflow, as well as the moderate pressure due to speaking and finger pressing and the high magnitude of plantar pressure. In addition, the gradient hydrogel demonstrates remarkable antibacterial properties and biocompatibility. This functional hydrogel with excellent sensing performance and bioactivity exhibits exceptional potential for wearable sensing applications.

Revisiting the oxygen reactivity index in traumatic brain injury: the complementary value of combined focal and global autoregulation monitoring

BackgroundThe oxygen reactivity index (ORx) reflects the correlation between focal brain tissue oxygen (pbtO2) and the cerebral perfusion pressure (CPP). Previous, small cohort studies were conflicting on whether ORx conveys cerebral autoregulatory information and if it is related to outcome in traumatic brain injury (TBI). Thus, we aimed to investigate these issues in a larger TBI cohort.Methods425 TBI patients with intracranial pressure (ICP)- and pbtO2-monitoring for at least 12 h, who had been treated at Addenbrooke’s Hospital, Cambridge, UK, were included. Association between ORx and ICP, pressure reactivity index (PRx), CPP, ΔCPPopt (actual CPP-CPPopt [PRx based optimal CPP]), and pbtO2 were evaluated with generalized additive models (GAMs). Association between ORx and outcome (Glasgow Outcome Scale [GOS]) was investigated with logistic regressions and heatmaps for those 239 patients with GOS data.ResultsGAMs showed that ORx increased with higher ICP, PRx above + 0.30, CPP below 60–70 mmHg, and negative ΔCPPopt. In contrast to PRx, ORx did not increase at higher CPP. In outcome heatmaps, there was a transition towards unfavourable outcome when ORx exceeded + 0.50, particularly for longer durations, and in combination with high ICP, high PRx, low CPP, negative ΔCPPopt, and low pbtO2. In multivariable logistic regressions, higher ORx was associated with increased mortality.ConclusionsORx seemed to be sensitive to the lower, but not the upper, limit of autoregulation, in contrast to PRx which was sensitive to both. The combination of high values for both ORx and PRx was particularly associated with worse outcome and, thus, ORx may provide a complementary value to the global index PRx. ORx could also be useful to determine the safe and dangerous perfusion target intervals.

Pressure and temperature response and phase transition path during small hole leakage in a near-industrial scale CO2 pipe

ABSTRACT As a large-scale CO2 migration method, pipelines play a crucial role in the CCUS industry chain. Small hole leakage caused by self defects, fatigue and corrosion, and natural disasters is a common accident in CO2 pipelines. When leaked CO2 is sprayed out through a small hole, the temperature inside the pipeline drops sharply under the Joule Thomson effect. This sudden temperature drop significantly reduces the toughness of the material, increases the risk of brittle fracture. In order to improve the CO2 pipeline release database, a new industrial scale CO2 pipeline has been built. The CO2 release experiments were carried out by using this experimental device. The experimental results showed that the pressure drop rate was fast under high pressure and then slowed down when the pressure dropped below the critical pressure, with the coexistence of gas and liquid. Rapid pressure drop and slight rebound occur during the leakage process, and low initial pressure leads to a more pronounced pressure plateau effect. Dense-phase CO2 leakage produced more dry ice than supercritical state, and the far field sublimation effect was more significant. In practice, particular attention should be paid to safety far from the leakage end.

Carotid bodies mediate glial cell activation and neuroinflammation in the NTS following long-term intermittent hypoxia: role in cardiorespiratory dysfunction.

Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, heightened chemosensory discharges of the carotid body (CB), which contributes to potentiate the ventilatory hypoxic response and elicits hypertension. We aimed to determine: 1) whether the persistence of cardiorespiratory alterations found in long-term CIH depend on the inputs from the CB and, 2) in what extension the activation of glial cells and neuroinflammation in the caudal region of the nucleus of the Solitary Tract (NTS) requires functional CB chemosensory activity. To evaluate these hypotheses, we exposed male mice to CIH for 60 days. At 50 days of CIH, CBs were denervated and animals were kept in CIH for 10 additional days. At the end of the experiments, we measured arterial blood pressure, breathing regularity, and hypoxic ventilatory response (HVR) and assessed astrocyte and microglia cell activation. Compared to Sham, CIH induces hypertension (MABP: 83.47±1.39 vs. 95.00±2.18 mmHg), disordered breathing (IS: 7.77±0.49 vs. 12.56±1.66), increased the HVR (1.69±0.17 vs. 4.31±0.87 ΔVE/min), and produced an early transient activation of astrocytes followed by a late and persistent activation of microglia in the NTS. In addition, CIH increased IL-1β, IL-6, and TNF-α levels in the NTS. Bilateral CB denervation after 50 days of CIH results in the restoration of normal glial cell activation in the NTS, lower levels of IL-6 and TNF-α, reductions in arterial blood pressure (83.47±1.38 mmHg) and HVR (1.63±0.43 ΔVE/min). Present results suggest that CB inputs to the NTS during long-term CIH contributes to maintain the cardiorespiratory alterations and the formation of a neuroinflammatory niche at the NTS by modifying glial cell activity.

Development of an Active Cerebrovascular Autoregulation Model Using Representation Learning: A Proof of Concept Study With Experimental Data.

It remains a challenge to monitor cerebrovascular autoregulation (CA) reliably and dynamically in an intensive care unit. The objective was to build a proof-of-concept active CA model exploiting advances in representation learning and the full complexity of the arterial blood pressure (ABP) and intracranial pressure (ICP) signal and outperform the pressure reactivity index (PRx). A porcine cranial window CA data set (n = 20) was used. ABP and ICP signals were preprocessed and downsampled to 20 Hz. Quadriphasic CA state labels were assigned to each piglet's CA curve and projected on their preprocessed ABP and ICP time series. Windowed ABP and ICP segments of 300 seconds, reflecting active CA, were used to optimize a neural network to reconstruct its own input. Reconstruction error of ABP and ICP were compared between active CA and inactive CA, and assessed together with PRx over quadriphasic CA states. The study confirmed that the optimized model achieved stellar reconstruction quality of ABP and ICP segments that derived from active CA while reconstruction quality deteriorated for segments that came from inactive CA. ABP and ICP reconstruction errors steadily increased concurrently with cerebral blood flow deviation from baseline. A significant interaction between variable and CA state showed that the model captured the differential behavior of CA with increasing vs decreasing cerebral perfusion pressures and offered improved discriminative ability regarding PRx. The present work showed that an active CA model can be built using advanced representation learning and the full complexity of 300-second ABP and ICP segments. On assessment in an experimental data set, relevant CA state information was present in both lower and higher frequencies of ABP and ICP. Improved discriminative ability between CA states was attained regarding PRx, which focuses only on slow-wave ABP and ICP information.

Positive end-expiratory pressure increases intracranial pressure but not pressure reactivity index in supine and prone positions: a porcine model study.

Positive end-expiratory pressure (PEEP) and prone positioning can improve gas exchange by promoting uniform lung aeration. However, elevated ventilation pressures may increase intracranial pressure (ICP) and disrupt cerebral autoregulation. This study investigated the effects of PEEP on ICP and cerebral autoregulation in a porcine model with healthy lungs and normal ICP, comparing prone and supine positions. Cerebral autoregulation was assessed through cerebrovascular reactivity using the pressure reactivity index (PRx). We also explored whether other baseline variables influenced potential variances in ICP and PRx. Twelve anesthetized pigs were randomized to begin in either supine or prone position, across PEEP of 5, 10, 15, and 20 cmH2O. Continuous monitoring included esophageal pressure to calculate end-inspiratory and end-expiratory transpulmonary pressures. The ICM+® software (University of Cambridge Enterprise, Cambridge, United Kingdom) was used for high-resolution data collection, signal processing and ICP curve analysis. Linear mixed-effects models and ANOVA were used to analyze changes in ICP and PRx and the influence of position. An exploratory correlation analysis was conducted on baseline variables potentially related to the ICP increase. Mean ICP increase was 1.0 mmHg ± 0.9 at 10 cmH2O PEEP, 2.0 mmHg ± 1.7 at 15 cmH2O PEEP, and 3.1 mmHg ± 1.6 at 20 cmH2O PEEP compared to a baseline PEEP of 5 cmH2O (p < 0.001). The effect of PEEP increase on ICP was not influenced by body position. PRx remained unaffected by PEEP. PEEP-induced increases in ICP were higher in cases of higher baseline ICP, higher central venous pressure, lower respiratory system elastance and lower end-inspiratory and end-expiratory transpulmonary pressures. Increasing PEEP elevates ICP regardless of body position without adversely affecting cerebral autoregulation in a healthy porcine model. Baseline ICP, central venous pressure, respiratory system elastance and end-inspiratory and end-expiratory transpulmonary pressure may influence the magnitude of ICP changes.

A fiber-shaped sensor constructed by coaxial wet-spinning for dual-mode sensing

This study made a skincore fiber sensor by co–axial wet spinning. It can accurately detect human movement and breathing due to its humidity and pressure response. Wireless signal modules were used for monitoring and interaction.

Physiological responses to low-intensity stationary cycling with intermittent positive and negative pressure an exploratory study

Background: This study evaluated the physiological responses to intermittent positive and negative pressure (IPNP) in 17 healthy, recreationally active individuals (10 males, average age 33.1 years, mean BMI 26.1 kg/m²) during stationary, upright cycling. Methods: We assessed acute IPNP effects on heart rate variability (HRV), blood pressure, and cardiovascular responses during moderate-intensity exercise. Participants engaged in two exercise modalities: Monark cycle ergometry (Mc) and cycling with IPNP, ranging from ±15 to ±25 Mbar. Results: Results indicated normal physiological responses in heart rate and systolic blood pressure (SBP) from rest to peak exercise in both modalities. A non-significant difference in SBP was observed during Mc compared to IPNP. Significant differences in mean arterial pressure were noted during recovery from IPNP cycling, highlighting a distinct cardiovascular response. HR increased in both conditions during exercise, with a more pronounced increase during Mc. Comfort and perceived exertion revealed no significant differences between the two modalities, indicating the potential acceptability of IPNP therapies. Conclusion: The study provides valuable insights into cardiovascular dynamics during stationary cycling with intermittent positive and negative pressure and highlights key physiological responses that warrant further investigation.

Deer Browsing Increases Stem Slenderness and Crown Irregularity and Modifies the Effects of Light Gradients on Architecture of Forest Tree Saplings.

Browsing by ungulates is commonly assumed to target the upper parts of sapling crowns, leading to reduced vertical growth or even growth cessation. However, the extent to which browsing induces shifts in resource allocation toward lateral growth remains unclear. This study explores the impact of browsing intensity (BI) and light availability on the architectural traits of six temperate tree species, focusing on height-diameter ratio (H/D), crown slenderness (CL/CW), and crown irregularity (CI) across sapling height classes. Browsing pressure and architectural responses varied across height groups, reflecting diverse adaptive strategies. BI was weakly but negatively correlated with sapling height, indicating that even tall saplings (> 2 m) experience browsing, particularly in the lower crown. H/D consistently increased with BI across all height classes, with stronger effects in medium and tall saplings. Light influenced H/D differently between browsed and unbrowsed saplings: unbrowsed saplings showed reduced H/D only under high light conditions, while browsed saplings exhibited consistent reductions regardless of light levels. CL/CW was negatively but insignificantly affected by BI. Light increased CL/CW in unbrowsed saplings across all height classes but decreased it in browsed short and medium saplings, suggesting a 'pruning' effect of browsing that altered competition dynamics. Species-specific analysis of Fagus sylvatica revealed an increase in CL/CW with BI, reflecting unique adaptive responses. CI increased significantly with BI across all height classes, with the strongest effects in medium and tall saplings. Light reduced CI in browsed short saplings but had inconsistent effects on unbrowsed individuals. Variation partitioning showed that light explained most variation in H/D and CL/CW for shorter saplings, while BI predominantly influenced CI in taller ones. By integrating the effects of browsing and light, this study provides insights into juvenile tree adaptations and resilience under ecological stressors, advancing our understanding of tree growth strategies in challenging environments.

Depression and cardiovascular reactions to acute psychological stress: Is anhedonia the driver?

Blunted cardiovascular reactions in response to acute psychological stress are predictive of future health risk. A large body of research has identified depression as an influential factor associated with blunted cardiovascular reactivity. Separately, there has been a resurgence in focus on anhedonia as a key feature of depression, responsible for poor treatment responses to non-improvement in cardiac event-free survival. In a re-analysis of a previously published study that found depression to be associated with blunted systolic blood pressure (SBP) and heart rate responses (HR), we used cross-sectional network models to examine if anhedonia symptoms were key drivers of this observation. Healthy young adults (N=180) completed measures of depression symptoms (Hospital Anxiety and Depression Scale (HADS)) and had their blood pressure and heart rate monitored throughout a standardized stress testing protocol. Using network analysis, a Walktrap algorithm identified two clusters of depressive symptoms: anhedonia and non-anhedonia. These anhedonia symptoms of depression, but not the non-anhedonia symptoms, were associated with blunted SBP and HR reactivity, such that those scoring higher on HADS-D items capturing anhedonia displayed more blunted cardiovascular response profiles. Moreover, these findings were robust to adjustment for several covariates. This study adds greater clarity on the depression-cardiovascular reactivity to stress association, by demonstrating that anhedonia is a key driver of this observation.

Comparative study of autonomic function in diabetics and yoga practitioners using Ewing’s battery

ABSTRACT Background: Diabetes mellitus (DM) is a chronic metabolic disorder characterized by high blood sugar levels. It significantly increases the risk of cardiovascular diseases and autonomic neuropathy. Yoga has been shown to improve autonomic function and glycemic control in diabetic patients. Objective: To compare the autonomic nervous system (ANS) function between diabetic patients and regular yoga practitioners using Ewing’s battery tests. Methods: This cross-sectional study included 270 participants, divided into two groups: 135 diabetics (Group I) and 135 yoga practitioners (Group II). Participants’ height, weight, and BMI were measured. ANS function was assessed using Ewing’s battery tests, which included heart rate (HR) and blood pressure (BP) responses to various stimuli. Statistical analysis was performed using SPSS, with significance set at P ≤ 0.05. Results: Diabetic participants showed lower HR responses to standing from a supine posture, the Valsalva maneuver, and slow deep breathing, indicating impaired parasympathetic function. They also exhibited higher BP responses to the cold pressor test, sustained handgrip, and standing, reflecting sympathetic overactivity. In contrast, yoga practitioners demonstrated better autonomic function with higher HR responses and lower BP responses in these tests. The findings suggest that yoga promotes parasympathetic dominance and reduces sympathetic overactivity. Conclusion: Regular yoga practice significantly improves autonomic function in individuals, including those with diabetes. These results support the incorporation of yoga as a complementary therapy in diabetes management to enhance cardiovascular health and reduce autonomic dysfunction.

Research on dynamic well control in riserless mud recovery system

In order to promote the development of RMR (Riserless Mud Recovery) system well control technology and ensure the safe operation of deep water drilling operations, the overflow control equation of RMR system considering the lifting force of subsea pump is established and verified, the conventional overflow monitoring method and the overflow monitoring method based on subsea pump parameter variation are compared and analyzed. the dynamic well control process of the RMR system after overflow under the two modes of constant subsea pump displacement and constant inlet pressure of subsea pump is simulated, and the influencing factors of inlet pressure of subsea pump are further analyzed. The results show that although the temperature effect is taken into account in the model established in this paper, the time error of the mud pool increment, the inlet pressure and the displacement of subsea pump after reaching the overflow criterion is less than 22.5% compared with Froyen's model. The conventional overflow monitoring method has fast response and small change, while the overflow monitoring method based on subsea pump parameter change is on the contrary, and the two should be used together. Both the constant inlet pressure of subsea pump mode and the constant subsea pump displacement mode can control overflow, but from the stability of subsea pump, service life and well control safety, the constant displacement mode is better. In the case of large formation pressure, low drilling fluid density, overflow criteria and circulating displacement, the pressure response adjustment speed of the subsea pump inlet is faster, and the back pressure load of the subsea pump inlet can be effectively alleviated by appropriately increasing the circulating displacement and drilling fluid density. This study has enriched the theoretical system of RMR system in overflow control, and has certain guiding significance for the development of deepwater and ultra-deepwater drilling safety technology.

Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions

Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions