Significant Pressure Increase Research Articles

The role of peripheral venous distension reflex in regulating hemodynamics: mini review

Significant volume is pooled in veins in humans and the amount is dramatically altered by various physiological stresses and diseases. Several animal and human studies demonstrated that limb venous distension evoked significant increases in blood pressure and sympathetic nerve activity (venous distension reflex, VDR). VDR has attracted much attention because of its potential to explain the still unknown mechanism of autonomic dysfunction in several diseases, which would lead to a new treatment approach. This mini review discusses accumulated evidence of VDR at this point and what should be investigated in the future to apply the current understanding of VDR in clinical practice.

TDAH : quels sont les effets cardiovasculaires du méthylphénidate et quelles sont les conséquences éventuelles pour la pratique clinique ?

ContextMethylphenidate is the first-line pharmacological treatment for ADHD, and its prevalence continues to grow, with an increase of 116% over the last ten years in France. Its use in hospitals has been extended to neurologists, psychiatrists and pediatricians, and its prescription can be renewed by a general practitioner. Cardiovascular complications are rare, but life-threatening. Management practices currently vary widely from one medical center or doctor to another. ObjectivesReviewing the cardiovascular effects of methylphenidate in adults and children with ADHD, aiming to propose a practical management plan without intending to replace existing recommendations. MethodsThe subject under study aimed to answer the following PICO question “What are the cardiovascular consequences (outcomes) when using MPH (intervention) for an ADHD population (population) regardless of age”. We carried out systematic review of international reviews and meta-analyses, selected using the PRISMA methodology via the PubMed, Cochrane Library and Google Scholar databases. Their methodological quality was assessed using the AMSTAR-2 scale. Cardiovascular events considered were the adrenergic effects of MPH on the cardiovascular system, looking for changes in blood pressure and heart rate, and the serious cardiovascular effects represented by sudden death/arrhythmia, myocardial infarction and stroke. A total of 17 systematic reviews and meta-analyses met the eligibility criteria. ResultsOf the 734 articles found, twelve were finally selected. Four concerned a population of children, five a mixed population of adults and children and three a population of adults only. They included two systematic reviews and ten meta-analyses. Three reviews included cohort studies and nine included randomized controlled trials. Three clinical situations can be distinguished depending on the age of the patient and the length of exposure to methylphenidate. The first, on initiation of treatment, there was a marked by a short-term increase in blood pressure and heart rate. The second involves a patient under the age of 35 with short- to medium-term exposure to MPH. A persistent adrenergic effect tends to increase the risk of sudden death by 12% (if the resting heart rate increases by ten beats per minute). This risk is further increased if the patient has psychiatric comorbidities and their associated treatments, congenital heart disease and uses recreational substances. Finally, the last situation involves a patient exposed to MPH for several years and aged over 35, whose main risk is the onset of atheromatous disease with myocardial infarction and ventricular arrhythmia. In this case, a comprehensive approach is required, identifying risk factors and behavioral factors likely to exacerbate the risk of CV disease. ConclusionsThe short-term cardiovascular effects of MPH are well documented and statistically significant, with a moderate but significant increase in blood pressure (+2mmHg) and heart rate (+5bpm). Longer-term cardiovascular safety data are often lacking, leading to conflicting conclusions. Meta-analyses of cohort studies conclude that there is an increase in cardiovascular risk, while meta-analyses of randomized trials find no significant statistical association. This means that patients and their families need to be made aware of this lack of data. Personalized management based on age, duration of exposure to MPH and the clinical profile of patients as defined by cohort studies seems to us to be the most appropriate approach. In people under 35, the main risk is sudden death. In this population, it is important to identify any congenital heart disease and to look for psychiatric comorbidities, and by assessing the substance abuse. For people over 35, the main risk is coronary heart disease. In this case, a comprehensive approach is required, identifying risk factors and behavioral factors likely to exacerbate the risk of CV disease. Our daily practice is more in line with cohort studies including patients with co-morbidities associated with their ADHD, as well as a significant risk of having risky behaviors, depressive episodes, heart disease and prolonged exposure to MPH and other drugs. Prescribing MPH in this context is tricky, with a higher risk of cardiovascular events. Close clinical monitoring is therefore necessary, and specialist advice may be required.

Abstract P225: Persistent Vascular Dysfunction and Blood Pressure Elevation Over 12 Months After COVID-19 Recovery in Non-Hypertensive Adults – LOCHINVAR Study

Background: The potential long-term vascular consequences of COVID-19, particularly in relation to future hypertension risk, remain poorly understood. This study aims to elucidate the longitudinal blood pressure trajectories in individuals who have recovered from COVID-19 but were not hypertensive prior to their infection, over a 12-month observational period. Methods: This study enrolled participants who had recovered from a hospital-admitted COVID-19 infection at least 12 weeks prior and had no history of hypertension. A control group was established from individuals with no prior SARS-CoV-2 infection, confirmed by a negative antibody test. All participants underwent ambulatory blood pressure monitoring (ABPM), flow-mediated dilation (FMD), and 6-minute walk test (6MWT) both at baseline and after 12 months. RAAS phenotyping was conducted at baseline. Paired t-tests and multivariable adjusted regression models were employed in the analyses of the full-dataset and per-protocol subset (because of variation in participant characteristics due to changing COVID-19 landscape during the recruitment period). Results: The full dataset had 97 participants (SARS-CoV-2 Negative:Positive 60:37) and per protocol data set had 66 participants (SARS-CoV-2 Negative:Positive 51:15). The median age was 50 (IQR:42-54) years with majority females. Per-protocol analysis revealed the positive group showed an increase in systolic and diastolic blood pressure (SBP/DBP) by 4.6/4.5 mmHg, a decrease in FMD by 3.2%, and an improvement in the 6MWT distance by 145.6 meters over 12 months, compared to the negative group (Figure 1). Baseline RAAS phenotyping showed no significant differences between groups. Conclusions: Our study demonstrates a significant increase in diastolic blood pressure 12 months following COVID-19 recovery in previously non-hypertensive individuals, accompanied by a decline in FMD. These findings suggest a possible vascular basis for the development of hypertension post-COVID-19 recovery.

Abstract P212: Microinjection of the novel angiotensin, alamandine-(1-5) into insular cortex, increase blood pressure

It is well known that the renin-angiotensin system plays a critical role in cardiovascular control and hydro-electrolyte homeostasis. At least in some circumstances Alamandine (Ala) and Angiotensin-(1-7) can have selective actions such as reported in the insular córtex (IC). Hydrolysis of Angiotensin-(1-7) by angiotensin converting enzyme (ACE) can form the heptapeptide Angiotensin-(1-5) and recently our group demonstrated that hydrolysis of Ala by ACE can form Ala-(1-5). In this study we aimed to evaluate the cardiovascular effects produced by microinjection of Ala-(1-5) and Angiotensin-(1-5) into the rostral region of the posterior IC. Urethane (1.4g/kg) anesthetized rats were instrumented for measurement of mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA). Unilateral microinjection of vehicle (0,9% NaCl, 100nL, n=4), Ala (40pmol/100nl, n=7), Ala-(1-5) (400pmol/100nl, n=7) or Angiotensin-(1-5) (400pmol/100nl, n=5) were made into IC (+1.5mm rostral to the bregma). At the baseline, there was no difference between the groups (Vehicle: 85±2 mmHg and 388±5bpm, Ala: 83±9mmHg and 389±10bpm, Ala-(1–5): 91±6mmHg and 386±7bpm or Ang-(1-5): 96±9mmHg and 375±6bpm). Vehicle microinjection was performed as a control for nonspecific effects (ΔMAP:2±1mmHg, ΔHR:4±2bpm, ΔRSNA:3±1%). Ala microinjection into IC, confirmed our previous data showing a long-lasting (18±3min) increase in MAP (Δ=14±2mmHg), and this effect was associated with a significant increase in HR (Δ=32±4bpm) and in RSNA (Δ=36±6%). These responses were elicited immediately after Ala microinjection. When compared with vehicle and, very different from what was observed with Ala, microinjection of Ala-(1–5) evoked a significant increase in blood pressure without altering RSNA or HR (ΔMAP:22±2mmHg, ΔHR:-1±3bpm, ΔRSNA:1±3%). Differently from Ala evoked responses, the effects of Ala-(1–5) had a shorter duration (5.88±1.9min) without delay to beginning the effects. On other hand, microinjection of Angiotensin-(1-5) did not elicited autonomic and cardiovascular effects (ΔMAP:-1±3mmHg, ΔHR:-2±2bpm, ΔRSNA:2±3%). In conclusion, these data showed that the IC is a brain site that has unique effects of Ala (increase in MAP, HR and RSNA) and Ala-(1-5) (increase in MAP only) contrasting with the essentially absent effects of Angiotensin-(1-7) and Angiotensin-(1-5). These findings will contribute to extend our understanding of the brain renin-angiotensin system.

Abstract P385: Effects Of a High Salt Diet On Glutamatergic Signaling In The Nucleus Of The Solitary Tract And Baroreflex Sensitivity

Hypertension remains a global health concern. Studies have shown a correlation with the loss of normal 24-hour blood pressure patterns and hypertension with a high salt diet. However, the mechanisms behind this are not fully known. The nucleus of the solitary tract (nTS), a key medullary nucleus involved in cardiorespiratory regulation, is known to modulate sympathetic outflow and blood pressure alterations.When blood pressure increases, baroreceptors in peripheral vessels detect these changes and send signals to the nTS through the neurotransmitter glutamate. Increased nTS glutamatergic signaling decreases blood pressure via efferent signals to the heart and blood vessels. The nTS integrates these signals and initiates responses through the baroreflex to counteract changes in blood pressure. Thus, baroreflex sensitivity (BRS), or a measure of how the baroreflex adjusts, serves as an indicator of the regulation of this feedback loop. An increased BRS indicates a more robust ability of the body to respond to blood pressure changes. Conversely, a reduced BRS is associated with hypertension, and autonomic dysfunction. Studies have shown that those with diet-induced hypertension also have a decreased BRS, however, the mechanism is not clear. We hypothesize that dysregulation of the 24-hour circadian glutamatergic signaling within the nTS may cause BRS decrease and hypertension. Salt-sensitive rats were subjected to either a normal salt diet (NSD, 0.4 % NaCl) or high salt diet (HSD, 4% NaCl) for 7 weeks. To determine nTS changes related to HSD, we measured blood pressure using 24/7 telemetry, and activation of glutamatergic neurons via immunohistochemistry (IHC). Antibodies against glutamate (CAMKII) and neuronal activation (cFos) were used to detect neuronal activation 6 hours apart, at the end of the NSD or HSD. Our preliminary findings reveal near significant decreases in glutamate signaling during the active period (at 9pm), suggesting a potential shift in the excitatory signaling in the nTS. Additionally, HSD over 7 weeks caused a significant increase in blood pressure and a decrease in BRS during the active period. Our preliminary data shows a connection between 24-hour regulation of glutamate within the nTS, diet-induced hypertension, and loss of BRS. This dysregulation in the blood pressure regulation underscores the importance of understanding the molecular mechanisms linking diet and development of disease.

Load Distribution After Serial Resection of the Posterior Horn of the Lateral Meniscus and Subsequent Meniscal Allograft Transplant: A Biomechanical Study

Background: Data are lacking as to when a meniscal allograft transplant (MAT) may be biomechanically superior to a partially resected lateral meniscus. Hypothesis: Lateral MAT using a bone bridge technique would restore load distribution and contact pressures in the tibiofemoral joint to levels superior to those of a partial lateral meniscectomy. Study Design: Controlled laboratory study. Methods: Eleven fresh-frozen human cadaveric knees were evaluated in 5 lateral meniscal testing conditions (native, one-third posterior horn meniscectomy, two-thirds posterior horn meniscectomy, total meniscectomy, MAT) at 3 flexion angles (0°, 30°, and 60°) under a 1600-N axial load. Pressure sensors were used to acquire contact pressure, contact area, and peak contact pressure within the tibiofemoral joint. Results: Limited (one-third and two-thirds) partial lateral posterior horn meniscectomy showed no significant increase in mean and peak contact pressures as well as no significant decrease in contact area compared with the intact state. Total meniscectomy significantly increased mean contact pressure at 0° and 30° (P = .008 and P < .001, respectively), increased peak contact pressure at 30° (P = .04), and decreased mean contact area in all flexion angles compared with the native condition (P < .01). Lateral MAT significantly improved mean contact pressure compared with total meniscectomy at 0° and 30° (P = .002 and P = .003, respectively) and increased contact area at 30° and 60° (P = .003 and P = .009, respectively), although contact area was still significantly smaller (24.1%) after MAT relative to the native meniscus (P = 0.015). However, allograft transplant did not result in better tibiofemoral contact biomechanics compared with limited partial meniscectomy (P > .05). Conclusion: The peripheral portion of the lateral meniscus provided the most important contribution to the distribution of contact pressure across the tibiofemoral joint in the cadaveric model. Total meniscectomy significantly increased mean and peak contact pressure in the cadaveric model and decreased contact area. Lateral MAT restored contact biomechanics close to normal but was not superior to the partially meniscectomized status. Clinical Relevance: Surgeons should attempt to preserve a peripheral rim of the posterior lateral meniscus. Meniscal allograft transplant appears to improve but not normalize mean contact pressure and contact area relative to total lateral meniscectomy.

Exposure to Lead in Drinking Water Causes Cognitive Impairment via an Alzheimer's Disease Gene-Dependent Mechanism in Adult Mice.

Exposure to lead (Pb) is a major public health problem that could occur through contaminated soil, air, food, or water, either during the course of everyday life, or while working in hazardous occupations. Although Pb has long been known as a neurodevelopmental toxicant in children, a recent and growing body of epidemiological research indicates that cumulative, low-level Pb exposure likely drives age-related neurologic dysfunction in adults. Environmental Pb exposure in adulthood has been linked to risk of late-onset Alzheimer's disease (AD) and dementia. Although the biological mechanism underlying this link is unknown, it has been proposed that Pb exposure may increase the risk of AD via altering the expression of AD-related genes and, possibly, by activating the molecular pathways underlying AD-related pathology. We investigated Pb exposure using a line of genetically modified mice with AD-causing knock-in mutations in the amyloid precursor protein and presenilin 1 (APPΔNL/ΔNL x PS1P264L/P264L) that had been crossed with Leprdb/db mice to impart vulnerability to vascular pathology. Our data show that although Pb exposure in adult mice impairs cognitive function, this effect is not related to either an increase in amyloid pathology or to changes in the expression of common AD-related genes. Pb exposure also caused a significant increase in blood pressure, a well known effect of Pb. Interestingly, although the increase in blood pressure was unrelated to genotype, only mice that carried AD-related mutations developed cognitive dysfunction, in spite of showing no significant change in cerebrovascular pathology. These results raise the possibility that the increased risk of dementia associated with Pb exposure in adults may be tied to its subsequent interaction with either pre-existing or developing AD-related neuropathology.

Early reapplication of prone position during venovenous ECMO for acute respiratory distress syndrome: a prospective observational study and propensity-matched analysis

BackgroundA combination of prone positioning (PP) and venovenous extracorporeal membrane oxygenation (VV-ECMO) is safe, feasible, and associated with potentially improved survival for severe acute respiratory distress syndrome (ARDS). However, whether ARDS patients, especially non-COVID-19 patients, placed in PP before VV-ECMO should continue PP after a VV-ECMO connection is unknown. This study aimed to test the hypothesis that early use of PP during VV-ECMO could increase the proportion of patients successfully weaned from ECMO support in severe ARDS patients who received PP before ECMO.MethodsIn this prospective observational study, patients with severe ARDS who were treated with VV-ECMO were divided into two groups: the prone group and the supine group, based on whether early PP was combined with VV-ECMO. The proportion of patients successfully weaned from VV-ECMO and 60-day mortality were analyzed before and after propensity score matching.ResultsA total of 165 patients were enrolled, 50 in the prone and 115 in the supine group. Thirty-two (64%) and 61 (53%) patients were successfully weaned from ECMO in the prone and the supine groups, respectively. The proportion of patients successfully weaned from VV-ECMO in the prone group tended to be higher, albeit not statistically significant. During PP, there was a significant increase in partial pressure of arterial oxygen (PaO2) without a change in ventilator or ECMO settings. Tidal impedance shifted significantly to the dorsal region, and lung ultrasound scores significantly decreased in the anterior and posterior regions. Forty-five propensity score-matched patients were included in each group. In this matched sample, the prone group had a higher proportion of patients successfully weaned from VV-ECMO (64.4% vs. 42.2%; P = 0.035) and lower 60-day mortality (37.8% vs. 60.0%; P = 0.035).ConclusionsPatients with severe ARDS placed in PP before VV-ECMO should continue PP after VV-ECMO support. This approach could increase the probability of successful weaning from VV-ECMO.Trial RegistrationClinicalTrials.Gov: NCT04139733. Registered 23 October 2019.

Bile Acid Metabolism Analysis Provides Insights into Vascular Endothelial Injury in Salt-Sensitive Hypertensive Rats.

As an unhealthy dietary habit, a high-salt diet can affect the body's endocrine system and metabolic processes. As one of the most important metabolites, bile acids can prevent atherosclerosis and reduce the risk of developing cardiovascular diseases. Therefore, in the present study, we aimed to reveal the bile acid metabolism changes in salt-sensitive hypertension-induced vascular endothelial injury. The model was established using a high-salt diet, and the success of this procedure was confirmed by detecting the levels of the blood pressure, vascular regulatory factors, and inflammatory factors. An evaluation of the histological sections of arterial blood vessels and kidneys confirmed the pathological processes in these tissues of experimental rats. Bile acid metabolism analysis was performed to identify differential bile acids between the low-salt diet group and the high-salt diet group. The results indicated that the high-salt diet led to a significant increase in blood pressure and the levels of endothelin-1 (ET-1) and tumor necrosis factor-α (TNF-α). The high-salt diet causes disorders in bile acid metabolism. The levels of four differential bile acids (glycocholic acid, taurolithocholic acid, tauroursodeoxycholic acid, and glycolithocholic acid) significantly increased in the high-salt group. Further correlation analysis indicated that the levels of ET-1 and TNF-α were positively correlated with these differential bile acid levels. This study provides new evidence for salt-sensitive cardiovascular diseases and metabolic changes caused by a high-salt diet in rats.

An Optimized Encryption Storage Scheme for Blockchain Data Based on Cold and Hot Blocks and Threshold Secret Sharing.

In recent years, with the rapid development of blockchain technology, the issues of storage load and data security have attracted increasing attention. Due to the immutable nature of data on the blockchain, where data can only be added and not deleted, there is a significant increase in storage pressure on blockchain nodes. In order to alleviate this burden, this paper proposes a blockchain data storage strategy based on a hot and cold block mechanism. It employs a block heat evaluation algorithm to assess the historical and correlation-based heat indicators of blocks, enabling the identification of frequently accessed block data for storage within the blockchain nodes. Conversely, less frequently accessed or "cold" block data are offloaded to cloud storage systems. This approach effectively reduces the overall storage pressure on blockchain nodes. Furthermore, in applications such as healthcare and government services that utilize blockchain technology, it is essential to encrypt stored data to safeguard personal privacy and enforce access control measures. To address this need, we introduce a blockchain data encryption storage mechanism based on threshold secret sharing. Leveraging threshold secret sharing technology, the encryption key for blockchain data is fragmented into multiple segments and distributed across network nodes. These encrypted key segments are further secured through additional encryption using public keys before being stored. This method serves to significantly increase attackers' costs associated with accessing blockchain data. Additionally, our proposed encryption scheme ensures that each block has an associated encryption key that is stored alongside its corresponding block data. This design effectively mitigates vulnerabilities such as weak password attacks. Experimental results demonstrate that our approach achieves efficient encrypted storage of data while concurrently reducing the storage pressure experienced by blockchain nodes.

Hydrogen reduction of iron ore pellets: A surface study using ambient pressure X-ray photoelectron spectroscopy

Using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS), this study investigates the reduction behavior of iron oxides in direct reduction (DRI) and blast furnace (BF) pellets. H2, CO, and a H2–CO mixture are used as reducing agents at 650 °C. The investigation aimed to elucidate variations in the rate of reduction over time and under different conditions. Additionally, contour plots are generated to visualize the X-ray photoelectron peak intensity variations as a function of time. Furthermore, phase stability diagrams based on Fe–O–C and Fe–O–H systems are employed to enhance the understanding of reduction behavior. Results revealed that an increased gas flow rate significantly accelerated the reduction rate due to enhanced gas diffusion, while elevated pressure facilitated the reduction of wüstite to metallic iron. Notably, the DRI pellet achieves around 90% metallization degree reduction with hydrogen, but the introduction of carbon monoxide into the reducing gas prevented the reduction of the DRI pellet. In the case of BF pellet reduction, approximately 20% metallization degree is observed using H2–CO (50:50), yet subsequent reoxidation of the reduced iron to wüstite and magnetite occurred. Further investigation identified a significant increase in the partial pressure of H2O and CO2, particularly within the surface porosities, as the underlying cause of this reoxidation phenomenon.

Evaluation of clinical outcome and predictors of mortality in patients undergoing antegrade transvenous variceal embolization in adjunct to salvage transjugular intrahepatic portosystemic shunt for active uncontrolled gastric variceal bleeding.

Salvage transjugular intrahepatic portosystemic shunt (TIPS) is indicated in patients with active endoscopically uncontrollable variceal bleeding. TIPS alone is not effective in the management of gastric varices, and balloon occluded transvenous obliteration (BRTO) requires favourable variceal anatomy. Concomitant placement of a TIPS stent with antegrade variceal embolization leads to control of gastric variceal bleeding with no significant increase in portal pressure. A single-centre retrospective observational study in which patients with active uncontrollable gastric variceal bleeding were included. Technical success of the procedure, 5-day rebleeding, 6-week, and 6-month survival, as well as other additional outcomes, were evaluated. A total of 18 patients were included in the study. Technical success was 100% and significant non-target embolization was seen in 0% of patients. The 6-week and 6-month survival rates were 66.67%, with an overall survival of 108.786 days (censored at 180 days). The 5-day rebleed rate was 11.1%. A significant difference in Child-Turcotte-Pugh score (P = .03), model for end-stage liver disease-sodium (MELD-Na) score (P = .022), requirement of intubation (P = .038), haemoglobin (Hb) levels (P = .042), haematocrit value (P = .018), packed red blood cell infusion required prior to and after the procedure (P = .045, .044), and presence of refractory shock (P = .013) was observed between the survival and the mortality groups. Post-variceal bleeding Hb levels, mean arterial pressure, and MELD-Na scores were significant predictors of mortality. TIPS in adjunct to antegrade transvenous embolization is a safe and effective modality for the management of active uncontrolled gastric variceal bleeding in patients with variceal anatomy unfavourable for performing retrograde obliteration. (1) TIPS alone may not be effective in the management of gastric varices. BRTO requires favourable variceal anatomy and may lead to catastrophic oesophageal variceal haemorrhage. Concomitant placement of a TIPS stent with antegrade variceal embolization leads to control of gastric variceal bleeding with no significant increase in portal pressure. (2) TIPS, in conjunction with antegrade transvenous embolization, requires proper knowledge of variceal anatomy and the embolizing agent. Post-variceal bleeding Hb levels, mean arterial pressure, and MELD-Na scores were significant predictors of mortality.

A Direct Comparison of a Power and an Energy-Optimized Li-Ion Pouch Cell: Characterization, Ageing and Modelling

Driven by the incredible transformation of the energy sector over the past 30 years lithium-ion batteries (LIBs) have seen continuous development and incredible improvements in terms of energy density, lifetime and power performance. Depending on their applications, Li-ion cells are normally optimized for either supplying as much power as possible or storing as much energy as possible, or a compromise between the two. A power optimized cell has typically a lower energy density and thinner electrode layers, compared to an energy optimized cell with higher energy density and thicker electrodes. One pathway to increase the performance of the modern LIBs is to move from conventional to thick electrode designs: this will result in an increased ratio of active components (anode/cathode) to inactive components (current collector, separator, casings) delivering improved energy densities. However, increasing the electrode thickness leads to several new challenges, such as e.g., reduced mechanical strength, higher tortuosity, and poorer rate performance, significantly affecting cell performance and ageing characteristics.In this study we aim to develop a fundamental understanding of electrode performance and limitations through the evaluation of both, high-energy and high-power electrodes from state-of-the-art commercial LIBs. For this purpose, we selected two renowned large-scale commercial Li-ion pouch cells with similar geometry, chemistry, and capacity: one optimized for power and the other for energy.Both cell types were tested following a test matrix including different temperatures, currents, and State-of-Charge limits as well as with and without mechanical compression of the cell during cycling. A large dataset with diagnostic data was recorded during ageing. This included, e.g., dQ/dV (Incremental capacity analysis, ICA), DC resistances and entropy changes. An especially strong influence of the current on the cycle life was observed for the energy-optimized cells. Cells without mechanical pressure had considerably shorter cycle life compared to cells cycled with mechanical pressure. Detailed monitoring of the pressure evolution across the pouch surface revealed significant pressure increases and thus electrode expansion throughout the cycling.Cell-tear-down analysis was done to reveal differences in battery design, especially electrode structure and thicknesses. The extracted materials were structurally characterized by, e.g., SEM, XRD, and x-ray computed tomography, and assessed electrochemically in coin full- and half-cells. The obtained data was then used to fully parameterize a P2D electrochemical model.The combination of detailed experiments coupled to P2D modelling provided valuable insights into influence of electrode thickness and morphology on battery performance and ageing, as well as degradation mechanisms specific to electrodes with increased thicknesses.

Excited‐State Dynamics and Optical Properties of Silica Under Ultrafast Laser Irradiation

AbstractExcited by intense infrared ultrafast light pulses, a wide bandgap material undergoes nonlinear ionization, generating a high density of free electrons in conduction states. As a result, the electronic band structure is critically modified and the bandgap shrinks. This induces rapid changes in optical properties, dramatically affecting the absorption spectrum during light coupling to the dielectric surface or during nonlinear propagation inside the bulk. This study analyzes the structural behavior and the modification of the optical properties of laser‐excited silica glass at the molecular cluster level through first‐principles simulations. Employing density functional theory and the GW approximations for band structure under nonequilibrium conditions, alongside the Bethe–Salpeter equation, the dynamics of the optical properties of fused silica are comprehensively explored. The behavior of excited fused silica in a wide photon energy range (from a few to 20 eV) is thus predicted. Laser‐induced electron excitation triggers a redistribution of charges between oxygen and silicon atoms, accompanied by a significant increase in electronic pressure, local atomic structure rearrangement, and material expansion. Molecular dynamics simulations offer a temporal perspective on the excited state dynamics, unveiling the intricate interplay between electronic and atomic effects on bandgap evolution. The analysis sheds light on excitonic resonances, intraband and interband transitions in fused silica under ultrafast laser irradiation, providing valuable insights into its excited state behavior and optical properties.

Effectiveness of different doses of dexmedetomidine on intraoperative haemodynamic profiles and postoperative pain in patients undergoing abdominal surgery at Dilla University Referral Hospital, Ethiopia, 2024: a double-blind randomized controlled trial.

Abdominal surgery stands as one of the most frequently conducted procedures across surgical specialties, accounting for up to half of surgery-related expenses. Hemodynamic instability emerges as a significant concern during anaesthesia and surgery, provoked by the stress of intubation, surgical incision, and anaesthetic agents. Following abdominal surgery, pain is an inevitable consequence, typically managed with opioid-based analgesia. However, the adverse effects associated with opioids often overshadow their analgesic benefits, particularly in the context of abdominal surgery. Consequently, there exists a necessity to explore and assess alternative non-opioid pain management options post-abdominal surgery as part of a broader strategy to reduce opioid usage. The primary aim of this investigation is to assess the effectiveness of varying doses of dexmedetomidine in regulating intraoperative hemodynamics and alleviating postoperative pain in patients undergoing abdominal surgery. Ethical clearance and institutional review board were obtained from the ethical clearance committee of Dilla University College of Medicine and Health Sciences with protocol unique number of duirb/008/22-01. Our trial has been prospectively registered on the Pan African Clinical Trial Registry with a unique identification number for the registry PACTR202208813896934. Statistical package and analysis were performed by using SPSS version 25. The distribution of data was checked by using Shapiro-Wilk test and the homogeneity of variance was checked by Levene's test. Analysis of variance (ANOVA) and Kruskal-Wallis H test were used for normally distributed continuous data and non-normally distributed or non-parametric data, respectively. P value less than 0.05 with a power of 90% was considered statistically significant. There was a statistically significant increase in mean SBP in the control group at the different critical time points (P<0.05), as compared to the baseline value, while there was no significant difference in mean systolic blood pressure (SBP) between the baseline and all other levels for group 2 and group 3. A statistically significant increase in mean arterial pressure (MAP) was detected in the control group at immediately after intubation (P=0.009) as compared to the baseline value, while a statistically significant reduction in mean heart rate (HR) was observed in group 3 at 15th min after infusion and at 30th 30 min after induction compared to baseline with a P value of 0.002 and 0.008, respectively.Conclusion:Perioperative low-dose infusion of dexmedetomidine at the rate of 0.4mcg/kg/h is a useful anaesthesia adjuvant to control hemodynamic stress response to critical periods. It is wise to use this infusion dose as part of general anaesthesia to achieve better hemodynamic stability.

Comparison of isometric handgrip test among pregnant offspring of hypertensive parents and pregnant offspring of non-hypertensive parents.

A family history of hypertension is one of the important risk factors for the development of pregnancy-induced hypertension (PIH). Offspring of hypertensive parents should be screened for PIH. The isometric handgrip (IHG) test is used to assess autonomic function among them. Autonomic function dysregulation can indicate their predisposition to develop PIH later in the course of pregnancy. To compare the IHG among pregnant offspring of hypertensive parents (Group 1) and non-hypertensive parents (Group 2). This is a cross-sectional study done among 100 pregnant women in the second trimester (50 participants in each group). Blood pressure responses to sustained hand grip for 2 minutes of maximum voluntary contraction (MVC) were recorded, immediately at the end of the IHG test and after 5 minutes of the IHG test. Independent t-test and Mann-Whitney U test were used to compare the responses in two groups. There is no statistical difference in basal blood pressure and heart rate between the two groups. Group 1 exhibited a significant increase in systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared to Group 2 immediately after 2 minutes of the IHG test. There is a significant increase in SBP after 5 minutes of the IHG in Group 2. Offspring of hypertensive parents have increased sympathetic reactivity and restoration of the blood pressure is significantly less compared to offspring of normotensive parents, which may predispose them for PIH. IHG can be applied as a convenient tool to screen the population who are at risk of PIH in places like primary health centres or field screenings where IHG is one possible option.

Understanding the Ocular Hypertension Model in Mice Induced by Dexamethasone-21-Acetate – Implications for Glaucoma Research

Purpose This study aimed to assess the effectiveness of monocular and bilateral injections of Dexamethasone-21-acetate (Dex-21-Ac) into the murine fornix twice a week as a glucocorticoid-induced ocular hypertension model and investigated potential systemic side effects. Methods Dex-21-Ac was administered twice weekly in three groups: bilateral injections, monocular injections, and a control group receiving the vehicle solution bilateral. After 21 days, enucleated eyes were examined using immunocytochemistry (ICC), and organ histology was performed. Results All groups receiving Dex-21-Ac injections had a significant increase in intraocular pressure (IOP). Monocular injections also resulted in a significant increase in IOP in the fellow eye. The Dex-21-Ac-treated groups showed a bilateral increase in IOP of approximately 8 mmHg, accompanied by elevated expression of alpha smooth muscle actin and fibronectin in the anterior chamber angle. There were no significant changes in weight progression. Hepatic steatosis was observed in all Dex-21-Ac-treated animals, and some suffered from residual neuromuscular blockade under fentanyl anesthesia. Conclusion Bilateral injections of Dex-21-Ac twice a week lead to a significant increase in daytime IOP and fibrotic changes in the trabecular meshwork. Unilateral application has a significant impact on the fellow eye. Local dexamethasone leads to notable systemic effects independent of changes in animal weight. Considering liver damage and associated influence on metabolization, hepatically eliminated injection anesthetics may lead to overdosing and are not recommended. They should be replaced by inhalation anesthesia.

The Stamping Method Utilizing a Double-Trough Die in Microforming to Enhance Formability.

Currently, the field of microgear manufacturing faces various processing challenges, particularly in terms of size reduction; these challenges increase the complexity and costs of manufacturing. In this study, a technique for microgear manufacturing is aimed at reducing subsequent processing steps and enhancing material utilization. This technique involves the use of trough dies with extrusion-cutting processing, which enables workpieces to undergo forming in a negative clearance state, thus reducing subsequent processing time for micro products. We conducted finite element simulations using microgear dies, measuring stress, velocity, and flow during the forming process of four types of dies-flat, internal-trough, external-trough, and double-trough dies. The results indicated that the buffering effect of the troughs reduced the rate of increase in the material's internal stress. In the cavity, the material experiences a significant increase in hydrostatic pressure, leading to the formation of a "hydrostatic pressure wall". This pressure barrier imposes substantial constraints on the flow of the material during dynamic processes, making it difficult for the material to move into the remaining areas. This effectively enhances the blockage of material flow, demonstrating the critical role of hydrostatic pressure in controlling material distribution and movement. In addition, combining the characteristics of both into a double-trough die enhances the overall stability of forming velocity, reduces forming load and energy consumption, and maximizes material utilization. Results further revealed that microgears manufactured using double-trough dies exhibited defect-free surfaces, with a dimensional error of less than 5 μm and tolerances ranging from IT5 to IT6. Overall, this study offers new insights into the traditional field of microgear manufacturing, highlighting potential solutions for the challenges encountered in current microstamping processes.

Evaluation of Exposure to Bisphenol Analogs through Canned and Ready-to-Eat Meal Consumption and Their Possible Effects on Blood Pressure and Heart Rate.

Bisphenols are endocrine-disrupting chemicals used in plastics and resins for food packaging. This study aimed to evaluate the exposure to bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) associated with the consumption of fresh, canned, and ready-to-eat meals and determine the effects of bisphenols on blood pressure and heart rate. Forty-eight healthy young adults were recruited for this study, and they were divided into the following three groups: fresh, canned, and ready-to-eat meal groups. Urine samples were collected 2, 4, and 6 h after meal consumption, and blood pressure and heart rate were measured. The consumption of ready-to-eat meals significantly increased urine BPA concentrations compared with canned and fresh meal consumption. No significant difference in BPS and BPF concentrations was observed between the groups. The consumption of ready-to-eat meals was associated with a significant increase in systolic blood pressure and pulse pressure and a marked decrease in diastolic blood pressure and heart rate. No significant differences were noted in blood pressure and heart rate with canned and fresh meal consumption. It can be concluded that total BPA concentration in consumed ready-to-eat meals is high. High BPA intake causes increase in urinary BPA concentrations, which may, in turn, lead to changes in some cardiovascular parameters.

An Experimental Investigation of Low-Frequency Active Excitation in Scramjet Combustor Using a Micro-Pulse Detonation Engine

A micro-pulse detonation engine (μPDE) was designed and installed to a direct-connect scramjet combustor of Pusan National University (PNU-DCSC). The active excitation on the scramjet combustor was experimentally studied using the μPDE operating at frequencies of 10–20 Hz. A vitiation air heater (VAH) was used to supply high-enthalpy vitiated air to the isolator and the scramjet combustor at a Mach number of 2.0, with a total temperature of 1600 K and a total pressure of 1.68 MPa. The exit of μPDE was located at the center of the cavity of the scramjet combustor. Active excitation was performed at equivalence ratios of 0.111 and 0.163, and characteristics were analyzed through Schlieren recording and bottom wall pressure measurement. As a result, when the detonation emitted from the μPDE entered the scramjet combustor, it instantly formed a shock train and moved forward within the scramjet combustor. The flame instantaneously changed from the cavity shear layer flame to the cavity flame. Through bottom wall pressure measurement, it was also observed that active excitation resulted in a significant pressure increase near the cavity compared to when active excitation was not performed. This revealed combustion characteristics, indicating improved combustion efficiency from the pressure increase in the scramjet combustor.