Increase In Pressure Research Articles

Optical Coherence Tomography Study of Choroidal Response to Exercise-Induced Hypertension in Chronic Central Serous Chorioretinopathy

Background/Objectives: The aim of this study was to evaluate the choroidal vascular response using optical coherence tomography (OCT) in patients with chronic central serous chorioretinopathy (CSCR) during transient increases in blood pressure. Methods: This observational, case–control study enrolled chronic CSCR patients and age-matched healthy controls. OCT scans of the macula were performed at rest and during hand-grip (HG) isometric exercise. Mean ocular perfusion pressure (MOPP) and subfoveal choroidal thickness (SCT) were measured at baseline and during stress. Quantitative OCT assessment included the bright area (BA, stroma), dark area (DA, vascular lumen), and total choroidal area (CA). The choroidal vascularity index (CVI) was calculated as DA/CA to assess vascular response to stress. A comparative analysis between CSCR patients and controls was conducted. Conclusions: MOPP was significantly higher (p = 0.008) at baseline in CSCR patients and further increased under stress compared to controls. SCT and CA were both significantly higher in CSCR patients than in healthy subjects at rest and under stress (p < 0.001), but no change occurred after HG. A significant decrease in CVI (p = 0.005) was noted in controls under stress, but not in CSCR patients. Additionally, a negative correlation between CVI and MOPP was found in healthy subjects (−0.648; p = 0.043). The study demonstrated a choroidal vasoconstrictive response to stress in healthy subjects, as evidenced by a decrease in CVI, but not in CSCR patients. This suggests that CSCR patients may experience impaired choroidal blood flow regulation, resulting in potentially higher perfusion pressures during stress without compensatory vasoconstriction, potentially affecting the choriocapillaris.

Effect of pre-shock on the expanding fracture behavior of 1045 steel cylindrical shell under internal explosive loading

Explosively driven expansion fractures in metallic shells will be preceded by a compression shock wave, which inevitably changes the mechanical and microstructural state of the shell materials and thus affects their subsequent dynamic deformation and expansion fracture processes. To understand the influence of pre-shock pressure on the dynamic expansion fracture behavior of metallic shells, the incident shock waves with varying peak pressure were generated in a 1045 steel cylindrical shell by sweeping detonation wave loading. The pre-shock and subsequent expansion fracture processes were continuously diagnosed by combining a high-speed framing camera and the arrayed Photon Doppler Velocimetry (PDV) measurements to obtain the fracture strains at different axial positions (corresponding to different pre-shock pressures). The results clearly show that the pre-shock pressure during detonation loading has a significant effect on the expansion fracture properties of the 1045 steel cylinder; the fracture strain remarkably decreases with the increase of pre-shock pressure from ∼19 GPa to ∼20 GPa and then changes gently in the range of ∼20 GPa to ∼22 GPa. Metallurgical analyses reveal increased densities of microstructural defects, including dislocations and deformation twins, when a shock wave passes through, resulting in a reduced capacity for further defect storage in the shocked metals, ultimately leading to a decrease in the fracture strain during the subsequent expansion deformation process.

An enhanced numerical model for considering coupled strain-softening and seepage effects on rock masses surrounding a submarine tunnel

The seepage of groundwater and the strain-softening of rock mass in a submarine tunnel expand the plastic region of rock, thereby affecting its overall stability. It is therefore essential to study the stress and strain fields in the rocks surrounding the submarine tunnel by considering the coupled effect of strain-softening and seepage. However, the evolution equation for the hydro-mechanical parameters in the existing fully coupled solution is a uniform equation that is unable to reproduce the characteristics of rock mass in practice. In this study, an updated numerical procedure for the submarine tunnel is derived by coupling strain-softening and seepage effect based on the experimental results. According to the hydro-mechanical coupling theory, the hydro-mechanical parameters such as elastic modulus, Poisson's ratio, Biot's coefficient and permeability coefficient of rocks are characterized by the fitting equations derived from the experimental data. Then, the updated numerical procedure is deduced with the governing equations, boundary conditions, seepage equations and fitting equations. The updated numerical procedure is verified accurately compared with the previous analytical solution. By utilizing the updated numerical procedure, the characteristics of stress field and the influences of initial pore water pressure, Biot's coefficient, and permeability coefficient on the stress, displacement and water-inflow of the surrounding rocks are discussed. Regardless of the variations in hydro-mechanical parameters, the stress distribution has a similar trend. The initial permeability coefficient exerts the most significant influence on the stress field. With the increases in initial pore water pressure and Biot's coefficient, the plastic region expands, and the water-inflow and displacement increase accordingly. Given the fact that the stability of the tunnel is more sensitive to the seepage force controlled by the hydraulic parameters, it is suggested to dewater the ground above the submarine tunnel to control the initial pore water pressure.

Pore formation and evolution mechanisms during hydrocarbon generation in organic-rich marl

Marine organic-rich marl is not only a high-quality hydrocarbon source of conventional oil and gas, but also a new type and field of unconventional oil and gas exploration. An understanding of its pore structure evolution characteristics during a hydrocarbon generation process is theoretically significant and has application prospects for the exploration and development of this special type of natural gas reservoirs. This study conducted thermal simulation of hydrocarbon generation under near-geological conditions during a whole process for cylinder samples of low mature marine organic-rich marl in the Middle Devonian of Luquan, Yunnan Province, China. During this process, hydrocarbon products at different evolution stages were quantified and corresponding geochemical properties were analyzed. Simultaneously, field emission scanning electron microscopy (FE-SEM) and low-pressure gas adsorption (CO2, N2) tests were applied to the corresponding cylinder residue samples to reveal the mechanisms of different types of pore formation and evolution, and clarify the dynamic evolution processes of their pore systems. The results show that with an increase in temperature and pressure, the total oil yield peaks at an equivalent vitrinite reflectance (VRo) of 1.03% and is at the maximum retention stage of liquid hydrocarbons, which are 367.51 mg/g TOC and 211.67 mg/g TOC, respectively. The hydrocarbon gas yield increases continuously with an increase in maturity. The high retained oil rate at the peak of oil generation provides an abundant material basis for gas formation at high maturity and over-maturity stage. The lower limit of VRo for organic matter (OM) pore mass development is about 1.6%, and bitumen pores, organic-clay complex pores together with intergranular pores, grain edge seams and dissolution pores constitute a complicated pore-seam-network system, which is the main reservoir space for unconventional carbonate gas. Pore formation and evolution are controlled synergistically by hydrocarbon generation, diagenesis and organic-inorganic interactions, and the pattern of pore structure evolution can be divided into four stages. A pore volume (PV) and a specific surface area (SSA) are at their highest values within the maturity range of 1.9% to 2.5%, which is conducive to exploring unconventional natural gas.

Mortality-related factors in older adults with delirium: A prospective observational study

BackgroundDelirium is a common and serious neuropsychiatric syndrome characterized by acute changes in attention, cognition, and consciousness. It is frequently encountered in various clinical settings, including critical care units and postoperative care, and is associated with significant morbidity and mortality. Understanding the factors contributing to delirium-related mortality is crucial for improving patient outcomes and healthcare practices. However, the factors associated with mortality in delirium have not been well-defined in the literature. ObjectivesThis study aimed to identify factors influencing 3-month mortality in older adults with delirium presenting to the emergency department (ED). MethodsThe study was conducted prospectively and delirium was screened using the brief Confusion Assesment Method (bCAM). The primary outcome was 3-month mortality. Mann-Whitney U and Chi-square tests compared groups, Spearman correlation analyzed correlations, and multivariate logistic regression identified risk factors. ResultsAmong 243 patients, 29.6% experienced in-hospital mortality, and 56.4% had 3-month mortality. Factors associated with increased mortality risk included prior delirium history (3.32-fold increase, 95%CI: 1.51-7.30), active malignancy (3.49-fold increase, 95%CI: 1.61-7.56) and increased respiratory rate (1.18-fold increase, 95%CI: 1.08-1.29). An increase in mean arterial pressure (MAP) was associated with a 0.98-fold decrease in mortality risk (95%CI: 0.96-0.99), increase in body temperature was associated with a 0.48-fold decrease in mortality risk (95%CI:0.31-0.76). ConclusionIn delirious older adults at the ED, higher respiratory rate, lower MAP, lower body temperature, active malignancy and prior delirium history signal elevated mortality risk.

Changes in portal pulsatility index induced by a fluid challenge in patients with haemodynamic instability and systemic venous congestion: a prospective cohort study

BackgroundIt is uncertain whether fluid administration can improve patients with systemic venous congestion and haemodynamic instability. This study aimed to describe the changes in systemic venous congestion and peripheral perfusion parameters induced by a fluid challenge in these patients, and to analyse the influence of the fluid responsiveness status on these changes.MethodsThe study is a single-centre prospective cohort study of 36 critically ill ICU patients with haemodynamic instability and a maximum vena cava diameter ≥ 20 mm. Changes in cardiac index during a fluid challenge (4 mL/kg of lactated Ringer’s solution during 5 min) assessed by pulse contour analysis, central venous pressure, ultrasound systemic congestion parameters (portal venous flow pulsatility index, supra hepatic and intrarenal venous Doppler), and peripheral perfusion parameters (capillary refill time and peripheral perfusion index) were assessed in the overall population. All these data were compared between patients presenting a cardiac index increase > 10% during the fluid challenge (fluid responders) and the others (fluid non-responders).ResultsTwenty-eight (78%) patients were admitted for postoperative care following cardiac surgery; their mean ± SD left ventricular ejection fraction was 42 ± 9% and right ventricular dysfunction was found in at least 61% of the patients. The mean ± SD SOFA score was 9 ± 3. Thirteen (36%) patients were fluid responders. The fluid challenge administration induced a significant increase in portal pulsatility index, VExUS score, and central venous pressure without significant difference of these changes between fluid responders and non-responders. No significant change in perfusion parameters was observed.ConclusionFluid administration in patients with haemodynamic instability and systemic venous congestion worsens venous congestion regardless of the fluid responsiveness status, without improving perfusion parameters.

Clinical and epidemiological characteristics of patients with pheochromocytoma and retroperitoneal paraganglioma

Introduction. Pheochromocytoma/paraganglioma (PPGL) is a rare hormonally active tumor of chromaffin tissue. Delayed diagnosis of this disease can lead to severe, even fatal, complications. Surgical treatment of PPGL without the necessary preoperative preparation can cause intraoperative uncontrolled hemodynamic impairment. In addition, since 2017, PPGL has been recognized as a malignant tumor due to the presence of metastatic potential. All these factors determine the need for early diagnosis of PPGL, which is based, first of all, on knowledge of the clinical picture by specialists in various fields.Aim. To check and confirm the epidemiological characteristics of PPGL as well as the most common clinical symptoms in the whole group of PPGL and in subgroups of clinical forms; to form a risk group for screening for PPGL.Materials and methods. There were enrolled 353 patients in the study. These patients were operated on at the St. Petersburg State University Hospital in the period from 2010 to 2022 inclusive. All the patients were verified PPGL diagnosis histologically. Clinical symptoms were assessed: a) retrospectively, by analyzing complaints and anamnesis from the initial examination in medical histories upon admission to the hospital for surgical treatment b) both in the entire group as a whole and in subgroups of clinical forms (paroxysmal, constant, mixed, asymptomatic). Statistical analysis was performed using the Python 3.11 programming language (Python Software Foundation, USA). descriptive statistics of quantitative characteristics are presented in the form of medians, first and third quartiles in me format [q1; q3], categorical features – in the form of absolute and relative frequencies in the format n (%). the frequency histogram was constructed using the Matplotlib 3.8.2 library.Results. PPGL is most common in women over 40 years of age. The most common symptoms of PPGL are the following: a feeling of rapid heartbeat (55.95%), headache (41.07%), arterial hypertension (AH) in the form of hypertensive crises (55.65%), constant increase in blood pressure (38.39%), episodes of moderate increases in blood pressure (24.11%), sweating (30.65%), general weakness and fatigue (26.19%), hot flashes or chills (24.11%). These symptoms are formed into the criteria for screening for PPGL. In the asymptomatic clinical form – lower back pain is more common (14%); with paroxysmal – panic attacks (10%); with mixed – thirst and dry mouth (10%), and with constant form – the actual constant nature of hypertension (100%).Conclusion. In a large sample of patients with a rare pathology, the most characteristic symptom complex was identified, characteristic of both PPGL and individual clinical forms. A risk group has been formed for screening for PPGL.

Non-equilibrium condensation flow characteristics of wet steam considering condensation shock effect in the steam turbine

A non-equilibrium condensation flow occurs in steam turbines, accompanied by condensation shock. At present, there are limited studies on the influence of condensation shock on the flow and condensation characteristics of wet steam, and the unsteady influence of condensation shock on the flow field of wet steam always have been ignored. In this paper, the unsteady flow characteristics of condensation were presented by considering the condensation shock effect. First, the condensation flow models and corresponding source terms were programmed and loaded with UDS (user-defined scalar) and UDF (user-defined function), respectively, and the governing equations were discretized using a high-resolution calculation method. The calculated results agreed well with the reported experimental results. Based on the models, the non-equilibrium condensation flow characteristics with inlet and outlet pressures in Laval nozzle considering the condensation shock effect were analyzed. Finally, during the unsteady phase change process, the effects of back pressure and saturation of the inlet on the liquid phase parameters were examined considering the condensation shock effect in the Dykas cascade. The results show that a decrease in the back pressure and an increase in the inlet pressure improve the condensation shock intensity in Laval nozzle. With the increase of condensation shock intensity, the nucleation rate increases. Moreover, in Dykas cascade, with the increase of back pressure from 48.8 kPa to 73.2 kPa, the maximum wetness decreases from 4.8 % to 2.1 %, whereas with the increase of relative saturation from 0.58 to 0.88, the maximum wetness increases from 2.4 % to 3.6 %. The results obtained in this paper are of significance to accurately analyze the actual situation of non-equilibrium condensation flow of wet steam and to develop methods for reducing wet steam loss in turbine stage.

Preparation and Electrochemical Performance of Alkaline Earth Metal-Doped Nd2Ce2O7 Proton Conductor Hydrogen Separation Membranes

Nd2Ce2O7 is a rare earth oxide with a fluorite structure and exhibits proton conductivity. Alkaline earth metals (Mg, Ca, Sr, Ba) doped Nd2Ce2O7 powders were synthesized using the citrate sol-gel method. The doped samples retain the fluorite structure, and enhanced oxygen vacancy concentration. Notably, Nd1.85Mg0.15Ce2O7-δ exhibited the highest oxygen vacancy concentration, reaching an electrical conductivity of 2.91×10-2 S•cm-1 in a humid atmosphere of 20%H2 and 80%N2 at 900°C. Hydrogen separation membranes were fabricated using alkaline earth metal-doped Nd2Ce2O7 as the proton-conducting phase and Pt as the electron-conducting phase. The results indicated that Pt-Nd1.85Mg0.15Ce2O7-δ had the optimal hydrogen permeation flux, reaching 8.35×10-9 mol•cm-2•s-1 at 900°C. It demonstrated short-term stability in environments containing CO2 and H2O, and an increase in temperature and hydrogen partial pressure on the feed side enhanced hydrogen permeation, highlighting its potential as a hydrogen separation membrane material.

Diagnostic Accuracy of Lung Ultrasonography Compared to Chest Radiography, BNP and Physical Examination in Patients with Dyspnea Suggestive of Pulmonary Edema: A Systematic Review and Meta-Analysis

Background: Pulmonary edema (PE) is the result of an abrupt increase in hydrostatic pressure in the pulmonary capillaries that leads to leakage of fluid through microvascular endothelial cells. This leads to a disruption of gas exchange in the lungs. Aims: This meta-analysis aimed to determine the diagnostic accuracy of lung ultrasonography (LUS) in pulmonary edema. Methods: A systematic search was conducted using a strategy based on these search terms (Lung ultrasonography, pulmonary edema, diagnostic accuracy); we searched PubMed, Google Scholar, and the Cochrane Library. Out of 1029, 14 prospective cross-sectional and observational studies with 2239 patients who reported the sensitivity and specificity of lung ultrasonography in diagnosing pulmonary edema were selected. For inclusion and data extraction, an independent review of citations was carried out. The data obtained were analyzed using SPSS, RevMan 5.3, and Stata 14.0 software. A quality assessment was conducted using the QUADAS-2 tool. The reference gold standard was the final clinical diagnosis according to chest radiography, B-type natriuretic peptide, and/or physical examination in dyspneic patients. Results: The overall sensitivity and specificity of lung ultrasonography in the diagnosis of pulmonary edema were 0.86 (95% CI, 0.81-0.90) and 0.91 (95% CI, 0.90-0.93), respectively, with a Younden index of 77.8%. The area under the receiver operating characteristic (ROC) curve was 0.889. Conclusion: The overall diagnostic odds ratio was 68.86. The results of this meta-analysis suggest that lung ultrasonography is an effective non-invasive technique in the diagnosis of acute pulmonary edema with rapid bedside examination and immediate interpretation.

Propagation of Hydraulic Fractures and Natural Fractures: The Bypassing Behavior in 3D Space

Summary The interaction between natural fractures (NFs) and hydraulic fractures (HFs) in 3D space poses significant challenges to numerical simulation. The interaction behaviors between HFs and NFs in 3D space include crossing, offset, stopping, and bypassing. Many existing numerical simulators are 2D, which inherently limits their ability to account for the vertical growth of fractures. Consequently, they are unable to model the bypassing behavior effectively. In this paper, a mathematical model for the propagation of HFs and NFs in a naturally fractured reservoir is established. The displacement discontinuity method (DDM) is used to solve the rock deformation, while the finite difference method (FDM) is utilized to solve the fluid flow within fractures. The undirected graph structure is used to represent the complex fracture network, and a dynamic adjustment of grid connectivity method is implemented to describe the process by which HFs bypass NFs. By integrating with graphics processing unit (GPU) computing, an efficient 3D simulator for HFs and NFs propagation is developed. The accuracy is verified against analytical solutions and reference solutions. Subsequently, a series of numerical studies on the bypassing behavior are conducted. The primary findings are as follows: (1) The simulator can accurately capture the interactions between HFs and NFs in 3D space, including crossing, arresting, and bypassing behaviors. (2) The bypassing behavior is characterized by three distinct processes—intersection, height growth of HF, and bypassing. (3) During the intersection stage, both the injection pressure and maximum NF width increase. During the height growth stage, the pressure is relatively stable, while the maximum NF width continues to increase. These two stages together result in the “storage” phenomenon. Once the bypassing behavior occurs, both the pressure and the maximum NF width decrease sharply, leading to a “release” phenomenon. Additionally, the “storage” and “release” phenomena may impact proppant transport. (4) Given the presence of bypassing behavior, it is essential to consider the NFs in 3D fracture simulators. The simulator and its findings can provide valuable insights for field design.

Supercontinuum saturation of a femtosecond laser filament in pressurized gases.

Filamentation of high-power femtosecond optical pulses in high-pressure gases has gained increasing academic and practical interest from the viewpoint of studying large-scale spectral and temporal transformations occurring with pulsed laser radiation and obtaining super-broadened spectra and extremely short (attosecond) wave packets. Experimentally and theoretically, for the first time to the best of our knowledge, we show that as a result of a 45 fs Ti:sapphire laser pulse filamentation in an optical cell filled with pressurized up to 50 bar nitrogen or argon, the pulse spectrum can reach maximally about eightfold broadening. This limiting pulse spectral width is reached at a gas pressure of about 20 bar and with further pressure increase exhibits saturation and even a slight decrease relative to the limiting value. As a possible reason for this finding, we suppose the increase of pulse energy depletion in the self-created plasma at high gas pressure.

Thermodynamic Modelling of a Twin-Stage Claw Vacuum Pump and Its Gas Pressurization Analysis

Multi-stage claw vacuum pumps are crucial in various industrial applications for efficiently achieving high vacuum levels compared to other positive displacement vacuum pumps. In order to elucidate the gas pressurization process of the multi-stage claw vacuum pump and clarify its structural design principles, the authors investigated a twin-stage claw vacuum pump as the main research subject, and analyzed its working characteristic. A thermodynamic model of the twin-stage claw vacuum pump describing the pressurization process was established, and the results were verified by means of experiments. Moreover, effects of the phase difference φⅠ-Ⅱ, the first-stage discharge port angle θd,Ⅰ and the thickness ratio B1:B2 on pump performance were discussed. Results show that as φⅠ-Ⅱ increases, the pump power of the first stage gradually increases, while the power of the second stage decreases and then increases. With the increase of θd,Ⅰ, the pump power decreases and then increases. When the suction pressure is 10kPa, the specific power reaches its minimum value under B1: B2=2:1. As the suction pressure increases, the pump power gradually increases, and its specific power fells substantially and then levels out. These contents are of great significance for the design and optimization of multi-stage claw vacuum pumps.

Enhanced strength-ductility synergy in a Ni–W–Co–Ta medium-heavy alloy via cryogenic supersonic fine particle bombardment

This study explores the influence of cryogenic supersonic fine particle bombardment (CSFPB) on a Ni–W–Co–Ta medium heavy alloy (MHA), and focus on the effect of gas pressure and impact time on the surface integrity, microstructural evolution, and mechanical properties of the MHA. CSFPB treatment creates a gradient structure, including surface layer with nanograins down to 9.0 nm due to severe plastic deformation, subsurface layer with high density dislocation structures and deformation twins due to weakened impact energy, and undeformed matrix. A key advantage of CSFPB is seen to be the cryogenic environment, which promotes superior surface integrity by reduced roughness. As the impact duration and gas pressure increase, the depth of deformation layer, surface hardness and strength of the MHA progressively rise. The optimal combination of strength and ductility is achieved at a gas pressure of 1.0 MPa for a duration of 90 s. This setting results in a maximum ultimate tensile strength of 1351 MPa and yield strength 796 MPa, with uncompromising elongation. However, excessively long treatment durations or high gas pressures can lead to the formation of surface microcracks, ultimately reducing the MHA's strength. Therefore, CSFPB offers the benefit of improved surface integrity through the cryogenic environment while maintaining a desirable balance between enhanced strength and ductility.

Evidence for interacting but decoupled controls of decisions and movements in nonhuman primates.

Many recent studies indicate that control of decisions and actions is integrated during interactive behavior. Among these, several carried out in humans and monkeys conclude that there is a coregulation of choices and movements. Another perspective, based on human data only, proposes a decoupled control of decision duration and movement speed, allowing, for instance, trading decision duration for movement duration when time pressure increases. Crucially, it is not currently known whether this ability to flexibly dissociate decision duration from movement speed is specific to humans, whether it can vary depending on the context in which a task is performed, and whether it is stable over time. These are important questions to address, especially to rely on monkey electrophysiology to infer the neural mechanisms of decision-action coordination in humans. To do so, we trained two macaque monkeys in a perceptual decision-making task and analyzed data collected over multiple behavioral sessions. Our findings reveal a strong and complex relationship between decision duration and movement vigor. Decision duration and action duration can covary but also "compensate" each other. Such integrated but decoupled control of decisions and actions aligns with recent studies in humans, validating the monkey model in electrophysiology as a means of inferring neural mechanisms in humans. Crucially, we demonstrate for the first time that this control can evolve with experience, in an adapted manner. Together, the present findings contribute to deepening our understanding of the integrated control of decisions and actions during interactive behavior.NEW & NOTEWORTHY The mechanism by which the integrated control of decisions and actions occurs, coupled or interactive but decoupled, is debated. In the present study, we show in monkeys that decisions and actions influence each other in a decoupled way. For the first time, we also demonstrate that this control can evolve depending the subject's experience, allowing the trade of movement time for decision time and limiting the temporal discounting of reward value.

Soot formation and laminar combustion characteristics of anisole: ReaxFF MD simulation and kinetic analysis

The application of biomass energy is one of the important ways to achieve carbon neutrality and deal with global warming. The study on the combustion mechanism of anisole, an oxygen-containing fuel, is helpful for biofuel large-scale application. In this study, the soot formation and laminar combustion characteristics of anisole were analyzed by reactive force field molecular dynamics (ReaxFF MD) and kinetic simulation, respectively. ReaxFF MD simulation studies had shown that soot formation of anisole combustion occurred in three stages, stage 1 (0–1 ns), stage 2 (1–2.5 ns), stage 3 (2.5–6 ns). The three stages represented the pyrolysis of the fuel, the developmental stage of the soot, and the graphitization stage of the soot, respectively. During the combustion of anisole, primary mechanisms for the soot formation were as follows: H-abstraction-C2H2-addition, carbon-addition-hydrogen-addition, internal ring formation and long carbon chain link. The formation of soot graphitization exhibited different morphologically behaviors: from flakes to onions to spheres with fewer branched chains. From the study of the laminar combustion characteristics of anisole, it can be found that the laminar burning velocities increased along with the increase of temperature, while the opposite trend was shown along with the increase of pressure. The sensitivity coefficient of naphthalene, the main soot precursor, revealed that the main promotional reactions for soot formation were R5 (O2 + H < = > O + OH), R36 (CO + OH < = > CO2 + H).

ДАВЛЕНИЕ НА ПОЧВУ БУНКЕРОВ-ПЕРЕГРУЖАТЕЛЕЙ В РАБОЧИХ ЦИКЛАХ ОБСЛУЖИВАНИЯ ЗЕРНОУБОРОЧНЫХ КОМБАЙНОВ

The problem of soil compaction by heavy transport equipment used to transport grain from combines, the solution of which is associated with the use of bunker-loaders (BL), is currently becoming more acute. However, the lack of indicators of the pressure on the soil of their running systems (when moving across fields) and the methodology for assessing the impact of BL on the soil with different body loads of grain, prevent comparative assessments of BL and an objective choice by agricultural producers of samples with the lowest pressure on the soil. The distances of passes across the field in the working cycles of BL for the variants of the number of combines serviced are modeled using original formulas as a result of research. It was found that the total length of the BL run across the field Ltotal in the working cycle is directly proportional to the length of the run Lg of the harvested field and the number of combines serviced. It consists of separate sections-passages characterized by successively increasing soil compaction, the value of which in turn depends on the mass of the loaded grain and the number of support wheels of the BP. The proposed expression for calculating the vertical load on the wheels of the bunker-loader, taking into account the change in the weight of the grain in the body, provides the ability to calculate the maximum pressure on the sections of the BP movement across the field when servicing combines for subsequent comparison with the regulated permissible pressure. It was found that with each loading of grain from the combine bunker, the maximum pressure of the wheels on the soil increases by 104 and 80 kPa for BP with four support wheels and by 38-50 kPa - with eight support wheels, with an increase in pressure to 382-394 kPa and with an excess of the permissible value by 1.8-1.9 times. When working with grain reception in a heavy-duty BP from three bunkers of TORUM combines instead of the possible four, the maximum pressure on the soil is reduced by 9.9% (from 382 to 344 kPa), and when receiving grain from two bunkers - by 20.7% (from 382 to 302 kPa).

The Effect of Process Parameters on the Pore Structure of Lotus-Type Porous Copper Fabricated via Continuous Casting

The pores in lotus-type porous copper are formed due to the difference in hydrogen solubility between the liquid and solid phases of copper. In a pressurized hydrogen atmosphere, hydrogen gas is released at the gas release and crystallization temperature, which is the melting point of copper. This study systematically analyzes the effects of process parameters, including hydrogen ratio, total pressure, and continuous casting speed, on the pore structure of lotus-type porous copper, with the aim of identifying the most critical process parameters for controlling pore diameter and density. Within the hydrogen ratio up to 50%, it was observed that as the hydrogen ratio increases, the pores tend to increase in porosity, and the pore diameter increases. As the hydrogen ratio increased from 25% to 50%, the pore diameter increased from 300 μm to 400 μm, while the pore density decreased from 3.3 N·mm−2 to 2.8 N·mm−2. As the total pressure increased, the pore diameter tended to decrease, and the pore density increased. Specifically, when the total pressure increased from 0.2 MPa to 0.4 MPa, the pore diameter decreased from 1100 μm to 400 μm, while the pore density increased significantly from 0.5 N·mm−2 to 2.8 N·mm−2. In addition, as the continuous casting speed increased, 30 to 90 mm·min−1, the pore diameter decreased from 850 μm to 400 μm, and the pore density increased from 0.7 N·mm−2 to 2.8. N·mm−2. Specifically, the increase in total pressure led to a decrease in Gibbs free energy and a reduction in the critical pore nucleation radius, which promoted pore formation and resulted in the creation of more, smaller pores. These results suggest that total pressure is the primary factor influencing both pore diameter and density in lotus-type porous copper.

Antihypertensive Activity Profile of Bangkirai Leaves (Shorea laevis Ridl.) Ethanol Extract on Angiotensin II (4ZUD) and β-Adrenergic (6PS5) Receptors

Hypertensive is a cardiovascular system disorder characterized by systolic pressure ≥ 140mmHg and diastolic ≥ 90mmHg. The increase in blod pressure is due to the mechanism of angiotensin II and β-adrenergic receptors, so in developing medicine for hypertension, compounds are needed to inhibit the activation of angiotensin II to angiotensin II, as well as β-adrenergic. Kalimantan, Indonesia has a biodiversity that has the potential as medicine such as Bangkirai (Shorea laevis Ridl.). Based on previous research on secondary metabolites, various compounds have been identified that have potential as new drug candidates, for example as antihypertensive. This study aims to determine the pharmacological profile and mechanism of angiotensin I inhibition at the 4ZUD and β-adrenergic receptors inhibition at the 6PS5 receptor, from ethanol extract of bangkirai leaves by carrying out molecular docking which begins with several stages including preparation and optimization of the structure of the test compound and structure preparation of 3D receptors 4ZUD and 6PS5. To find out the correctness of the method, validation was carried out on the Olmesartan ligand compound for 4ZUD and the propranolol ligand for 6PS5. Based on research carried out on both receptors, results were obtained for the test compounds in the form of MolDockScore, the pharmacological profile of absorption, distribution, metabolism, excretion, and toxicity. MolDockScore results show that the compound Colchicine, N-desacetyl-N-[4-hydroxy-3,5-dimethoxycinnamoyl] has the lowest values, namely -146.503 at the 4ZUD receptor dan -129.718 at the 6PS5 receptor, which is close to the natural ligand value compared to other metabolite compounds. Apart from that, it also provides good results based on the pharmacological profile of the 4ZUD and 6PS5 receptors including HIA (95.73%), Caco2 (35.14nm/second), and PPB (87.67%). Negative test results are also shown in the mutagenic toxicity profile (Ames Test Method), non-mutagenic, and carcinogenic tests which include genotoxic and nongenotoxic.

Efficacy of Suprachoroidal versus Intravitreal Triamcinolone Acetonide in Refractory Macular Edema; A Quasi-experimental study

Objective: To compare the efficacy of suprachoroidal vs intravitreal triamcinolone acetonide in management of refractory macular edema. Study Design: Quasi-experimental study Place and Duration of Study: Ophthalmology Department, Fauji Foundation Hospital, Rawalpindi Pakistan, from Jun to Nov 2022. Methodology: A total of three hundred and seventy-eight eyes of 189 patients were selected after approval from the Institutional Ethics Review Board. In this study, individuals were divided into two Groups using lottery method: Group-A, received suprachoroidal triamcinolone acetonide and Group-B, received intravitreal triamcinolone acetonide. After intervention, both Groups were followed up at 1 and 3 months. Baseline central macular thickness was noted in each Group. Patients were also observed for complications. Statistical Package for Social Sciences version 23 was utilized for data analysis. Results: No significant differences were noted between both Groups at baseline Central Macular Thickness (p-value =0.29), However, significant difference was noted at 3-month Central Macular Thickness (p-value as &lt;0.001). Very few compli-cations were observed in both Groups. Conclusion: This study revealed that both suprachoroidal and intravitreal routes of administering triamcinolone acetonide were equally effective. Significant reduction in Central Macular Thickness and no increase in Intraocular Pressure along with better tolerance for treatment were seen in suprachoroidal route in our research which indicated its safety.