Pressure Modulation Research Articles

Crystalline state in a pressure region of proceeding amorphization of SnI4

ABSTRACT Room-temperature compression with a diamond-anvil cell without pressure-transmitting media has detected SnI 4 's pressure-induced solid-state amorphization at around 15 GPa. Multianvil apparatus compression employed in this study shows us an entirely different aspect; instead of undergoing amorphization, SnI 4 remains crystalline, which is stabilized by heating from room temperature. This crystalline state could be the metallic phase, the high pressure modification, whose existence has been known, but the structure remains unresolved. Surprisingly, this crystalline state transforms to another crystalline state, not yet reported thus far, before returning to the ambient phase upon isothermal decompression at about 530 K and 640 K. Combined Angle- and Energy-Structural Analysis and Refinement (CAESAR), devised by Wang et al. (J Appl Cryst. 2004;37;947), with which to convert energy-dispersive diffraction patterns to those of angle-dispersive ones, is demonstrated as a profitable approach that can compensate a standard energy dispersive measurement.

Chemical‐Strain‐Engineered Adaptive Interfaces in Nanocomposite Films for Robust Ferroelectricity

AbstractStrain is an effective means of tuning the crystal structure to obtain a variety of fascinating properties, but how to apply flexible strain to meet the different needs of the film at each location has rarely been reported. In this study, a novel approach for designing strain‐damping structures that facilitate the imposition of flexible strain is introduced. A wide range of strain modulation is demonstrated in SmCoO3 films (a‐axis:+4.5%–+1.7%, b‐axis: +3.2%–+0.4%, c‐axis:+2.2%–+1.4%) under positive pressure by introducing Sm2O3 as a dopant. When SmCoO3 films are subjected to triaxial tensile strain, they exhibit a ferroelectric polarization of 7.12 µC cm−2. Through positive pressure modulation, resulting in a further increase in the ferroelectric polarization (up to 11.62 µC cm−2, which represents the maximum performance of the orthogonal rare earth transition metal oxide family). Moreover, the electron spin order can be effectively controlled, and the film's saturation magnetization increases to 14.83 emu cm−3 (+94.1%). This damping structure allows for flexible modulation of chemical strain in epitaxial film, achieving a delicate balance between film strain and structure, which provides valuable insights for all ferroelectrics based on structural distortion.

Optimizing Lasing Performance of CsPbBr3 Microplates by Regulating Exciton Recombination Dynamics with Pressure.

This study aims to achieve an ultralow lasing threshold in CsPbBr3 microplates (MPs), a crucial step toward developing electrically driven micro/nanolasers for optics integrated chips. We investigate the lasing behavior of CsPbBr3 MPs under varying pressures by using static-state photoluminescence (PL), time-resolved PL (TRPL), and first-principles theory calculations based on density functional theory (DFT). Our results reveal that the lasing threshold initially decreases and then increases, with a critical turning point at 0.44 GPa. Notably, we achieve an optimal lasing threshold of 20.87 μJ/cm2 after releasing pressure from 1.87 GPa, highlighting the potential of pressure modulation to optimize the lasing performance. At low pressure, pressure-induced phonon hardening enhances the barrier, preventing excitons decay from free states to trapping states. Conversely, at higher pressure, the increased density of surface defects, due to pressure-induced anisotropic contraction of lattice constants along the c-axis, leads to excitons decay from free states to trapping states. For CsPbBr3 MPs, it is evident that only free excitons contribute to lasing, while both free and trapped excitons contribute to luminescence. These findings offer a novel strategy to optimize the lasing performance of perovskite micro/nanolasers, significantly advancing their potential for practical applications in optoelectronic devices.

Pressure Modulation Improves Locomotion of an Expanding Robot for Colonoscopy

Abstract Colonoscopy plays a pivotal role in early colorectal disease detection. It is hindered by procedural difficulties such as friction between colonoscope and colon wall as well as maneuverability issues. Expanding robots offer a promising alternative, aiming for a reduced risk of tissue damage and reduced forces between colononscope and tissue. In this paper, the usage of expanding locomotion for colonoscopy is investigated to address technical challenges. Preliminary tests on a custom-designed test rig demonstrate the potential of intermitted advancement and retraction modes to overcome challenges such as the difference in pathlength of robot body and working channel as well as the typical buckling during retraction of expanding robots. Future research will focus on refining control systems based on sensor feedback and evaluating additional parameters for clinical application.

Synthesis and characterization of MIL-101 metal-organic framework and its application as filler for Pebax2533 membrane

Global warming poses a significant environmental challenge, highlighting the urgent need to reduce and manage greenhouse gas emissions, especially carbon dioxide (CO2). One promising approach to mitigating this issue is membrane separation technology. Herein, the MIL-101 metal-organic framework was synthesized, characterized, and incorporated as a filler (0–40 wt.%) into Pebax®2533 polymer. Gas permeability measurements were conducted using a constant pressure module for pure gases at a fixed feed pressure (2 bar) and temperature (298 K). Various analytical techniques, such as FESEM, FTIR, TGA, and mechanical strength analyses, were employed for membrane characterization. Analytical techniques confirmed excellent particle dispersion and proper adhesion between the polymer and filler particles without void formation. The results showed substantial improvements in the selectivity for H2/N2 and CO2/N2, surpassing the values of the neat membrane by 52.33% and 52.56%, respectively, due to the narrow pore size of the filler. Despite the improvement in gas permselectivity, the permeability of all gases decreased with filler content compared to the pure membrane. Polymer chain rigidification and possible blockage of filler pores by polymer chains could be the main reasons for the decrease in gas solubility inside the Pebax rubbery polymer.

Impact of ultra-high pressure on the microstructure, emulsification, and physicochemical properties of rice starch

Ultra-high pressure (UHP) treatment is considered a non-thermo physical treatment technology with a “clean label”. Starch is an ideal stabilizer for food-grade Pickering emulsions. This study aimed to investigate the effects of ultra-high pressure (UHP) modification of rice starch on its structure, water/oil absorption, and emulsification properties under different pressure treatments (100–500 MPa), the results showed that the morphology of the starch granules and crystalline structure did not change significantly at lower pressures. Conversely, the particle size of starch increased significantly from 4.85 to 110.13 μm, the relative crystallinity (RC) obviously decreased from 18.89 % to 9.18 %, and the starch granules were destroyed and formed more fragments at higher pressure (500 MPa). The results of water/oil absorption indicated that the oil absorption slightly increased under UHP treatment, but water absorption intensively increased under higher pressure (500 MPa). The emulsifying capacity was significantly enhanced at 500 MPa after 8, 16, and 24 min. The UHP treatment induced swelling and disruption of starch granules at higher pressure (500 MPa). The starch fragments and the released starch molecules stabilized the droplets. This study provides a reference for the application of UHP processing in the starchy foods.

NIMG-64. SURVIVAL IMPLICATIONS OF POSTOPERATIVE RESTRICTED DIFFUSION IN HIGH-GRADE GLIOMA AND LIMITATIONS OF INTRAOPERATIVE MRI DETECTION

Abstract AIMS In glioma surgery, surgically induced cerebral ischemia may poorly affect overall survival. While intraoperative MRI (iMRI) is an established tool used to maximize extent of resection, its ability to detect cerebral ischemia during surgery has not been studied. Here we evaluate both the association of post-surgical cerebral ischemia on survival independent of new functional deficits and the sensitivity of iMRI in detecting cerebral ischemia. METHODS We retrospectively reviewed 361 cranial surgeries that used a 3 Tesla iMRI. 165 patients met all inclusion criteria and were included in the final analysis. Diffusion weighted imaging (DWI) obtained during iMRI was compared to postoperative DWI obtained within 7 days of the operation in cases where no further resection occurred after the iMRI. RESULTS 42 of 165 patients (25%) showed evidence of restricted diffusion on postoperative (poMRI); 37 of these 42 (88%) lacked evidence of restricted diffusion on iMRI (false-negative rate of 88%, sensitivity of 12%). In high-grade gliomas, poMRI restricted diffusion volume was predictive of overall survival independent of new functional deficit (p = 0.011). CONCLUSION Here we present the largest case series to date analyzing the sensitivity of iMRI in detecting ischemia. In high-grade gliomas, increased volume of ischemia correlated with worsening median overall survival (OS) irrespective of postoperative neurologic deficits. Future work will focus on improving intraoperative detection of ischemia during the hyperacute phase when interventions such as blood pressure modulation or direct application of vasodilator agents may be effective.

A new flexible-wall triaxial permeameter for localized characterizations of soil suffusion

Suffusion involves the migration of fines within the soil matrix, which may cause many types of geohazards. Localized characterization of suffusion is necessary because suffusion is inhomogeneous. However, existing studies on localized characterization have primarily relied on rigid-wall permeameters, which prevent lateral soil deformation and might introduce preferential flow, biasing the experimental results. In this study, a new flexible-wall triaxial permeameter was developed for the localized characterization of suffusion. The permeameter testing system has four modules: a loading and permeating module, a pressurized water supply module, an outflow collecting module and a back pressure supply module. The local pore water pressure is captured by an invented perforation socket that connects transducers to the specimen through the flexible wall without water leakage. The local deformation is measured by photography. Three repeated suffusion tests on complete decomposed granite were carried out using the new permeameter. The results show that the maximum coefficients of variation of the initial seepage velocity, clogging hydraulic gradient, critical hydraulic gradient and total loss of fine particles are less than 4.9%, demonstrating satisfactory reliability. Soil suffusion is better characterized and understood since a localized indicator and a precursor for suffusion-induced failure are considered.

Calcitriol prevents SARS-CoV spike-induced inflammation in human trophoblasts through downregulating ACE2 and TMPRSS2 expression

SARS-CoV-2, the causative virus of COVID-19, increases the risk of pregnancy complications including hypertensive disorders and placental inflammation. The spike glycoprotein mediates viral cell entry by interacting with the angiotensin-converting enzyme (ACE)2 in conjunction with the transmembrane serine protease 2 (TMPRSS2). ACE1, ACE2 and renin are components of the renin-angiotensin system (RAS), which regulates blood pressure. As the placenta expresses all these proteins, it is a target for SARS-CoV-2 and a source of blood pressure modulators. Noteworthy, an ACE1/ACE2 ratio imbalance can lead to RAS dysregulation and a bad prognosis in COVID-19 patients. Calcitriol, the most active vitamin D metabolite, negatively regulates RAS, reduces inflammation, and enhances antiviral immunity, thereby protecting against COVID-19 severity. However, contrasting information exists on the regulatory role of calcitriol upon RAS components and SARS-CoV-2 receptors; while the impact of calcitriol on spike-induced inflammation in placental cells has not been explored. Thus, we studied the effects of calcitriol on these parameters using the trophoblast cell line HTR-8/SVneo and primary syncytiotrophoblasts. By RT-qPCR, ELISA, and immunocytochemistry, we found that the spike enhanced proinflammatory cytokines expression and secretion, while calcitriol significantly downregulated this effect. Calcitriol also diminished ACE1, ACE2, TMPRSS2, and renin gene expression, as well as ACE1/ACE2 mRNA ratio. ConclusionsIn the human placenta, calcitriol reduced the gene expression of main RAS components and TMPRSS2, resulting in the inhibition of spike-induced inflammation. This outcome suggest that vitamin D participates in restricting SARS-CoV-2 placental infection by rendering trophoblasts less permissive to infection while helping to regulate maternal blood pressure and decreasing inflammation.

Walking On Thin Ice: Understanding and Preventing Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) are a serious side effect of diabetes that frequently results in amputations, extended hospital stays, and infections. Peripheral artery disease (PAD), neuropathy, smoking, long-term diabetes, foot abnormalities, and a history of ulcers or amputations all raise the chance of developing DFUs. Usually, a combination of Gram-positive and Gram-negative bacteria, anaerobes, and fungi cause the infections in DFUs. Comprehensive care, such as blood glucose management, lifestyle modifications, routine foot assessments, appropriate footwear, and patient education, is the focus of prevention initiatives. For people who are at risk of DFUs, wearing shoes that fit properly, abstinence of smoking, and managing blood pressure and cholesterol are important preventive measures. the use of multiple treatments is needed for patients who already have foot ulcers. This includes debridement, pressure unloading, wound dressings, and maybe surgery. To remove necrotic tissue and to promote healing, debridement techniques include surgery, enzymatic, autolytic, and biological debridement (such as maggot therapy) are crucial. For the treatment of neuropathic ulcers, pressure modulation using methods such as total contact casts (TCC) is potential. Numerous cutting-edge wound dressings, such as hydrogels, hydrocolloids, and dressings infused with silver, help control wound moisture, enhance autolysis, and fight against infection. Revascularization, nonvascular foot surgery for abnormalities, or amputation in extreme circumstances are all possible surgical therapeutic options. strategies are required for long-term prevention and care for treating both the ulcer and the underlying causes of DFU. Ultimately, lowering the incidence of DFU and enhancing patient outcomes require a mix of efficient communication, patient education, and coordinated treatment among healthcare providers

Modification of Additional Check Valves and Tube Pressure to Enhance Hydram Pump Capacity and Performance for Agricultural Applications

Pump that operates automatically by relying on natural power from water without using great cost and trouble by pumping hydram. Hydram pumps are one of the types of pumps that are driven by kinetic power, it was discovered by a 1796 Montgolfier in Italy. The purpose is to determine the most optimal water speed of the hydram pump by using different numbers of pressure tubes and several check valves. This research uses a factorial Randomised Group Design (RGD) method. The first treatment is valve variation and the second is variation in the number of tubes. The results showed that the average river water flow velocity was 0.154 meters/second with an average water discharge of 2.61 m3/second under normal flow conditions. The average water flow in the intake pipe is 0.717 meters / second and the volume of water in the pipe is 15.19 liters with an average water discharge entering the intake pipe is 10.804 m3 / second. A combination of three valves and three tube treatments consistently produces greater water discharge than other combinations. The highest efficiency of the hydram pump is found in the combination of three checks.

Modulation of blood pressure by dietary potassium and sodium: Sex differences and modeling analysis.

High Na+ intake has been linked to elevations in blood pressure, whereas K+ has the opposite effect. The underlying mechanisms involve complex interactions among renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. These mechanisms are likely moderated by sex, given the known sex differences in blood pressure regulation and the higher prevalence of hypertension in men. The source of these observed sex differences may be traced to organ and tissue levels, given that kidney function, intrarenal renin-angiotensin system components, renal sympathetic nervous activity, and nitric oxide bioavailability all exhibit sex differences. To assess the functional impact of each of these sex differences, we developed sex-specific computational models to simulate whole-body Na+, K+, and fluid homeostasis, and the effects on blood pressure. The models describe the interactions among the renal system, cardiovascular system, gastrointestinal system, renal sympathetic nervous system, and renin-angiotensin-aldosterone system. Model simulations suggest that women's attenuated blood pressure response to hypertensive stimuli, including high Na+ intake, may be largely attributable to the female renal transporter abundance pattern. Additionally, we investigated the causal link between high K+ intake and blood pressure reduction. The models simulate renal response to high K+ intake, including the immediate gastrointestinal feedforward signals to the kidneys to increase K+ excretion, and the longer-term response to decrease proximal fractional Na+ reabsorption and distal K+ reabsorption. With these assumptions, simulations of high K+ intake yielded kaliuresis, natriuresis, and a substantial reduction in blood pressure, even when combined with high Na+ intake.

Enhanced Study of CO2 Hydrate Formation in Marine Oil–Gas Based on Additive Effect

During marine oil–gas extraction, significant amounts of carbon dioxide (CO2) gas are often produced. Effectively separating these associated CO2 gases during extraction has become a critical technical challenge. Therefore, this paper aims to enhance the efficiency of CO2 hydrate-based capture technology and conduct relevant research. The goal is to increase the driving force for hydrate formation by combining the traditional thermodynamic additive TBAB with pressure modulation and to improve the hydrate formation rate through the use of multiple kinetic promoters. This paper presents the initial investigation into the effect of the thermodynamic accelerator tetrabutylammonium bromide (TBAB) on the characteristics of CO2 hydrate formation. The promotion effects of TBAB solutions with varying mass concentrations (3%, 5%, 7.5%, 10%) and reaction pressures (3 MPa, 4 MPa) were subjected to a systematic analysis, and the optimal conditions were identified as 4 MPa and a 5 wt% TBAB concentration. Subsequently, the impact of combining TBAB with kinetic promoters (SDS, nano Al2O3, L-methionine, L-leucine) on CO2 hydrate generation characteristics was further investigated. In this paper, the effect of a single promoter on the generation characteristics of CO2 hydrate was investigated, and the efficient carbon trapping ability of the complex promoter was verified, which provides theoretical support for the application of CO2 trapping technology using the hydrate method.

Modulation of Blood Pressure through Microbiome Exchange between Milan Normotensive and Hypertensive Rat Strains

Modulation of Blood Pressure through Microbiome Exchange between Milan Normotensive and Hypertensive Rat Strains

Characteristic analysis and diagnosis method optimization of scroll compressor pressure pulsation signal under voltage fluctuation

Under off-design conditions, scroll compressors can lead to reduced efficiency, motor damage, and even cause safety problems such as leaks or explosions. To solve the above problems, this paper analyzes the influence mechanism of different voltages on the spectrum of pressure pulsation signal and modulation signal and provides theoretical support for fault diagnosis and enhances the interpretability of the model. A voltage fault diagnosis method of scroll compressor based on Time-frequency Principal component Convolutional Network (TPCN) model is proposed. By demodulation analysis of the pressure pulsation signal of the low-pressure inlet and high-pressure outlet of the refrigerant in the scroll compressor, the spectrum information of the principal component modulation signal under different voltages is obtained. The pooling strategy is used to accurately identify and extract the fault information in the modulated signal spectrum as the input data of the model. The input data is divided into the training set and the test set according to the ratio of 8:2 to complete the training and testing of the fault diagnosis model. The experimental results show that the accuracy of TPCN model for the diagnosis of 5 types of faults reaches 100 %. The average accuracy of the model is 100 %, which indicates that the model has good stability.

Novel Insights into the Kallikrein-Kinin System in Fulminant Myocarditis: Physiological Basis and Potential Therapeutic Advances.

Fulminant myocarditis (FM) is characterized by rapid cardiac deterioration often instigated by an inflammatory cytokine storm. The kallikrein-kinin system (KKS) is a metabolic cascade known for releasing vasoactive kinins, such as bradykinin-related peptides, possessing diverse pharmacological activities that include inflammation, regulation of vascular permeability, endothelial barrier dysfunction, and blood pressure modulation. The type 1 and type 2 bradykinin receptors (B1R and B2R), integral components of the KKS system, mediate the primary biological effects of kinin peptides.This review aims to offer a comprehensive overview of the primary mechanisms of the KKS in FM, including an examination of the structural components, regulatory activation, and downstream signaling pathways of the KKS. Furthermore, it explores the involvement of the tissue kallikrein/B1R/inducible nitric oxide synthase (TK/B1R/iNOS) pathway in myocyte dysfunction, modulation of the immune response, and preservation of endothelial barrier integrity. The potential therapeutic advances targeting the inhibition of the KKS in managing FM will be discussed, providing valuable insights for the development of clinical treatment strategies.

Microscale Flow Control and Droplet Generation Using Arduino-Based Pneumatically-Controlled Microfluidic Device.

Microfluidics are crucial for managing small-volume analytical solutions for various applications, such as disease diagnostics, drug efficacy testing, chemical analysis, and water quality monitoring. The precise control of flow control devices can generate diverse flow patterns using pneumatic control with solenoid valves and a microcontroller. This system enables the active modulation of the pneumatic pressure through Arduino programming of the solenoid valves connected to the pressure source. Additionally, the incorporation of solenoid valve sets allows for multichannel control, enabling simultaneous creation and manipulation of various microflows at a low cost. The proposed microfluidic flow controller facilitates accurate flow regulation, especially through periodic flow modulation beneficial for droplet generation and continuous production of microdroplets of different sizes. Overall, we expect the proposed microfluidic flow controller to drive innovative advancements in technology and medicine owing to its engineering precision and versatility.

Terms for describing atmospheric deposition of substances on surfaces

Relevance. The need to assess the state of the environment based on the use of terminology for quantitative chemical characteristics of the underlying surface as a result of deposition of pollutants in the composition of wet and dry fallout from the atmosphere. Aim. This study can be a source of information about the terminology used to describe the state of the underlying surface during the deposition of substances from the atmosphere, with links to scientific and technical literature. Methods. Review of some scientific and technical literature and an attempt to select terms used to quantify the ecological state of the underlying surface, mainly snow, after the arrival of substances as part of dry and wet deposition from the atmosphere, depending on the sampling method. Results and conclusions. The author has carried out an analysis of the scientific and technical literature and defined the terms applied to a quantity that has the dimension mass/area*time for assessing the ecological state of the snow cover, such as specific reserve (surface density), deposition density, atmospheric deposition density, precipitation intensity pollutant, daily deposition of chemical elements, technogenic load, dust load, pollution load (element), mass load, gas-aerosol load, technogenic pressure module, input module, atmospheric fallout module, mass of the determined component received at unit area, flux obtained on the basis of sampling during snow chemical survey. An analysis of the scientific and technical literature was also carried out and the terms applied to a value with the same dimension mass/area*time were defined to assess the ecological state of the underlying surface during the deposition of substances from the atmosphere, such as "fallout density", "atmospheric fallout density", “pollutant fallout intensity”, “aggravating substance", "precipitation", "critical load", "flow" obtained based on sample collection using plates, cuvettes, collections.

A review of gut microbial metabolites and therapeutic approaches in hypertension

Abstract Background Hypertension is a prevalent and complex disease that is increasingly recognized to be influenced by the gut microbiome and its metabolites. Understanding the relationship between gut microbial metabolites and blood pressure regulation could provide new therapeutic avenues. Main body This review examines the role of key microbial metabolites—short-chain fatty acids, trimethylamine N-oxide, tryptophan derivatives, polyamines, bile acids, and phenylacetylglutamine—in blood pressure regulation. Short-chain fatty acids, produced through dietary fiber fermentation, can lower blood pressure by modulating immune responses and reducing inflammation. Elevated trimethylamine N-oxide levels are associated with increased cardiovascular risk and hypertension, influencing cholesterol metabolism and promoting atherosclerosis. Tryptophan derivatives interact with vascular and renal functions to modulate blood pressure. Polyamines affect blood pressure regulation through their impact on nitric oxide synthesis and vascular tone. Bile acids influence blood pressure via gut microbiota modulation and activation of metabolic receptors. Phenylacetylglutamine has been linked to hypertension through its effects on platelet hyperactivity and thrombosis. Therapeutic approaches targeting these metabolites, including probiotics, prebiotics, fecal microbiota transplantation, dietary interventions, and polyphenols, have shown varying degrees of success. Probiotics and prebiotics promote the growth of beneficial gut bacteria and may lower blood pressure. Dietary interventions, such as the Mediterranean diet, positively affect blood pressure and cardiovascular health by modulating the gut microbiota. Polyphenols, known for their antioxidant properties, are associated with blood pressure reductions and improved vascular function. Fecal microbiota transplantation shows promise in restoring gut microbial balance and improving metabolic health, potentially influencing blood pressure regulation. Conclusion The review highlights the significant role of gut microbial metabolites in regulating blood pressure, offering new avenues for hypertension management. Key metabolites, including short-chain fatty acids, trimethylamine N-oxide, and bile acids, play critical roles in blood pressure modulation. Therapeutic strategies targeting these metabolites, such as probiotics, prebiotics, and dietary interventions, hold promise, though further research is needed to fully understand their mechanisms and optimize their use. Advancing microbiota-based interventions through large-scale studies and exploring personalized therapies will be essential for developing effective treatments in hypertension management.

High pressure and high temperature modulation of electrical conductivity in high hardness silicon nitride-carbon composites

Electrically conductive silicon nitride ceramics with both high hardness and electrically conductive properties are promising advancing ceramics. However, ensuring the high hardness while simultaneously enhancing their electrical conductivity poses a great challenge. In this work, Si3N4-carbon composites with different carbon content were synthesized with diamond phase transformation method under high pressure and high temperature (HPHT). The α→β phase transition in silicon nitride enables the coexistence of α/β phases, offering a hardness of up to 23.15 ± 0.08 GPa, comparable to dense silicon nitride ceramics and significantly higher than synthesized silicon nitride-graphite composites. Diamond uniformly distributed in the silicon nitride matrix is graphitized at high temperatures to form conductive channels, reducing resistivity to 2 × 10-⁴ Ω∙m, over a dozen orders of magnitude lower than pristine silicon nitride. This phase transition sinter mechanism provides a method for designing conductive Si₃N₄-based ceramics with high hardness.