Pressure Values Research Articles

Non-isothermal mathematical model of blocking tecnogenic fractures

Nowadays, large oil fields have moved to the stage of declining production, to maintain reservoir pressure, it is necessary to apply flooding technologies. To maintain the previous rates of oil production, it is necessary to force selections by increasing the value of downhole pressure on the injection wells. However, the risks of exceeding the fracturing pressure are increasing, which can lead to the formation of technogenic fractures. An intensive increase in the fracture can lead to an increase in the risks of premature water reaching through it into the drainage zone of the producing wells, which will lead to an increase in the value of the water oil ratio. The analysis of current numerical mathematical models of colmatation of technogenic fracture has shown the status of determining the volume of leaks of the colmatation agent beyond the fracture, considering changes in the temperature field at the bottom of the injection well. This problem is relevant, since special research complexes have been conducted at several oil and gas fields to determine the growth of technogenic fractures that arose because of excess fracturing pressure and fell into the drainage zone of producing wells. A change in the temperature field of the reservoir will allow direct changes in the viscosity of the injected colmatation agent, as well as determine the amount of leakage of the agent beyond the limits of the technogenic fractures. The article describes the construction of a non-isothermal physico-mathematical model of injection of a suspension system (water-reagent) into the reservoir, considering changes in the temperature field of the reservoir, the volume of reagent leaks beyond the limits of the technogenic fracture, considered for the first time. The aim of the work is to establish the dependences of the leakage volume of the colmatation agent, the critical time of filling the fracture from changes in the temperature field at the bottom of the injection well. A nonisothermal reservoir simulation model has been constructed showing the stages of initiation of a technogenic fracture with its subsequent colmation. The distribution of the concentration of the colmatation reagent both in the fracture and outside it, depending on the change in the temperature field at the bottom of the well, is obtained. It is determined that the volume of reagent leaks decreases if changes in the temperature field at the bottom of the injection well are considered with identical well operation parameters and geological and physical characteristics of the formation.

An investigation of hydraulic fracturing initiation and location of hydraulic fracture in preforated oil shale formations.

Horizontal well fracturing technology enables the commercial production of low-permeability reservoirs, with perforation fracturing technology serving as a critical component of multistage fracturing for horizontal wells. However, the presence of the horizontal wellbore and the perforation borehole significantly complicates the distribution of the local stress field. The extension behavior of hydraulic fractures cannot be accurately described. The mechanisms of initiation and extension of fractures resulting from perforation fracturing require further investigation. By employing the principle of superposition and considering the effects of far-field stress, fluid pressure within the wellbore, filtration loss of fracturing fluid, and temperature variations, the distribution of the stress field around the perforation has been elucidated. A theoretical model for calculating hydraulic fracture initiation pressure and location was developed based on the stress distribution pattern and the established rock damage criterion for various rock types. The accuracy of this theoretical model was validated through real triaxial hydraulic fracturing experiments. A combination of theoretical calculations and perforation fracturing experiments revealed that the fracture initiation location for perforation fracturing occurs at the intersection of the perforation borehole and the horizontal wellbore. Moreover, a comprehensive fracturing calculation guideline was proposed for varying fracturing conditions by comparing the theoretical and experimental values of fracture initiation pressure. The findings presented in this paper are anticipated to enhance the prediction of hydraulic fracture initiation pressures and locations in perforation fracturing.

Retrospective analysis of non-pharmacological factors associated with ineffective control of arterial hypertension in a clinical sample

Introduction. Arterial hypertension (HT) is the most common risk factor of cardiovascular diseases and leads to increased premature mortality. About half of HT patients do not reach the target values of blood pressure (BP).Aim: To assess the frequency of failure to achieve the target BP level and to identify non-pharmacological factors associated with inefficient BP control in a clinical sample of patients with hypertension.Material and Methods. A sequential clinical sample of patients (n = 105, 19–84 years old) with an established diagnosis of HT receiving antihypertensive therapy (AHT), was examined. Clinical data were analyzed in groups with efficient (ECHT, n = 29) and inefficient control of hypertension (ICHT, n = 76) by the time of admission to the hospital.Results. In the entire sample, the proportion of ICHT (72%) was higher compared to ECHT (28%). The groups did not differ in age, anthropometry, menopausal status in women, and duration of HT, but with an increase in the degree of hypertension, the proportion of patients with NCAH increased. There were more women in ECHT group, and there were equal proportions of men and women in ICHT group. In the ICHT group, we observed higher values of HDLC, more frequent chronic heart failure (CHF) and single atherosclerotic plaques (AP) of carotid and other peripheral arteries; in the ECHT group, the average levels of plasma glucose, glycated hemoglobin, the proportion of smokers were higher, and type 2 diabetes and multiple AP were more common. The AHT (doses, regimen, combinations) was more adequate in the ECHT group. About half of the patients received combination therapy.Conclusion. In the clinical sample, one third of HT patients receiving AHT, had blood pressure controlled to target at hospital admission. Inefficient blood pressure control was associated with male gender, a higher level of HDLC, the high degree of HT, single AP and CHF. In the efficient control group, smoking, comorbidity with type 2 diabetes, multiple AP, higher glucose levels and HbA1c were more often noted.

Development and Evaluation of a Deep Learning-Based Pulmonary Hypertension Screening Algorithm Using a Digital Stethoscope.

Despite the poor outcomes related to the presence of pulmonary hypertension, it often goes undiagnosed in part because of low suspicion and screening tools not being easily accessible such as echocardiography. A new readily available screening tool to identify elevated pulmonary artery systolic pressures is needed to help with the prognosis and timely treatment of underlying causes such as heart failure or pulmonary vascular remodeling. We developed a deep learning-based method that uses phonocardiograms (PCGs) for the detection of elevated pulmonary artery systolic pressure, an indicator of pulmonary hypertension. Approximately 6000 PCG recordings with the corresponding echocardiogram-based estimated pulmonary artery systolic pressure values, as well as ≈169 000 PCG recordings without associated echocardiograms, were used for training a deep convolutional network to detect pulmonary artery systolic pressures ≥40 mm Hg in a semisupervised manner. Each 15-second PCG, recorded using a digital stethoscope, was processed to generate 5-second mel-spectrograms. An additional labeled data set of 196 patients was used for testing. GradCAM++ was used to visualize high importance segments contributing to the network decision. An average area under the receiver operator characteristic curve of 0.79 was obtained across 5 cross-validation folds. The testing data set gave a sensitivity of 0.71 and a specificity of 0.73, with pulmonic and left subclavicular locations having higher sensitivities. GradCAM++ technique highlighted physiologically meaningful PCG segments in example pulmonary hypertension recordings. We demonstrated the feasibility of using digital stethoscopes in conjunction with deep learning algorithms as a low-cost, noninvasive, and easily accessible screening tool for early detection of pulmonary hypertension.

Comparative thermodynamic study of CO2 transcritical supermarket booster refrigeration system combined with vapor injection and parallel compressionÉtude thermodynamique Comparative du système de réfrigération transcritique de supermarché au CO2 combiné à l'injection de vapeur et à la compression parallèle

The use of CO2 refrigerants in supermarket refrigeration has recently demonstrated great potential owing to their excellent thermophysical properties and environmental protection. To further improve the efficiency of transcritical CO2 refrigeration systems, a parallel compression cycle with vapor injection system (SRC) is proposed. Thermodynamic model is established to investigate the influence of working condition parameters and compared with basic booster refrigeration system (BRC) and parallel compression refrigeration system (PRC). In addition, the effect of vapor injection parameters on the characteristics of the proposed system is investigated. The results show that the medium pressure has little effect on BRC, while the optimum value exists for both PRC and SRC. The performance of the three systems can be significantly enhanced by optimizing the discharge pressure and medium pressure. The optimal value of the relative vapor injection pressure is constant at about 1.15. The maximum coefficient of performance (COPmax) of the SRC is significantly improved by 23.99%∼32.14% and 14.44%∼20.07% at disccussed working conditions compared with BRC and PRC, respectively. In summary, this paper confirms the performance enhancement potential of the proposed cycle and provides theoretical support for its practical implementation.

Secured and cloud-based electronic health records by homomorphic encryption algorithm

This uses homomorphic encryption in cloud-based platforms to improve electronic health records (EHR) security and accessibility. Protecting sensitive medical data while enabling data processing and analysis is the main goal. The study examines how homomorphic encryption protects EHR data privacy and integrity. Its main purpose is to reduce risks of unauthorized access and data breaches to build trust between healthcare professionals and patients in digital healthcare. The research uses homomorphic encryption to safeguard cloud EHR storage and transmission. Results will highlight the algorithm's influence on data security and computing efficiency, revealing its potential use in healthcare to protect patient privacy and meet regulatory requirements. Results from dataset of patient health metrics show in the 1st instance sample data for 5 instances with ages between 57 to 88, blood pressure (BP) values from 33 to 85, glucose values from 5 to 99, and heart rate values from 24 to 88. In another study of 5 patients, cholesterol levels ranged from 10 to 80 mg/dL, body mass index (BMI) from 10 to 96 kg/m², smoking status from 14 to 79, and medication adherence from 6 to 78%.

Measurement, analysis and utilization of meteorological parameters for radio signal propagation modeling – tropospheric refraction

Abstract The paper deals with wave propagation in the troposphere and discusses practical estimates of the refractive index, which determines how much the path of radio-wave is bent, or refracted, in the troposphere. Refractive index (RI) is a function of relative air humidity, air temperature and air pressure while the tropospheric refractivity depends on their height profile. Based on balloon measurements in the Prague meteorological station and mast measurements at Kopisty meteorological station, statistical characteristics of RI are calculated and their sensitivity to changes in pressure, temperature and relative humidity is quantitatively estimated. The paper includes figures and tables that can be used to provide a basic estimate of RI for specified atmospheric properties given by temperature, pressure and relative humidity. The results show that the RI is not very sensitive to pressure values and instead depends strongly on temperature and this dependence increases with increasing relative humidity. It should be emphasized that the RI undoubtedly depends on the local climatology of the quantities from which it is calculated.

Multi-compartment impact of micropollutants and particularly antibiotics on bacterial communities using environmental DNA at river basin-level.

Bacterial communities respond to environmental conditions with diverse structural and functional changes depending on their compartment (water, biofilm or sediment), type of environmental stress, and type of pollution to which they are exposed. In this study, we combined amplicon sequencing of bacterial 16S rRNA genes from water, biofilm, and sediment samples collected in the anthropogenically impacted River Aconcagua basin (Central Chile, South America), in order to evaluate whether micropollutants alter bacterial community structure and functioning based on the type and degree of chemical pollution. Furthermore, we evaluated the potential of bacterial communities from differently polluted sites to degrade contaminants. Our results show a lower diversity at sites impacted by agriculture and urban areas, featuring high loads of micropollution with pesticides, pharmaceuticals and personal care products as well as industrial chemicals. Nutrients, antibiotic stress, and micropollutant loads explain most of the variability in the sediment and biofilm bacterial community, showing a significant increase of bacterial groups known for their capabilities to degrade various organic pollutants, such as Nitrospira and also selecting for taxa known for antibiotic resistance such as Exiguobacterium and Planomicrobium. Moreover, potential ecological functions linked to the biodegradation of toxic chemicals at the basin level revealed significant reductions in ecosystem-related services in sites affected by agriculture and wastewater treatment plant (WWTP) discharges across all investigated environmental compartments. Finally, we suggest transitioning from simple concentration-based assessments of environmental pollution to more meaningful toxic pressure values, measured environmental concentrations normalised by effect information, in order to comprehensively evaluate the role of micropollutants at the ecological (biodiversity) level.

Computational exploration of injection strategies for improving medicine distribution in the liver.

The liver, a vital metabolic organ, is always susceptible to various diseases that ultimately lead to fibrosis, cirrhosis, acute liver failure, chronic liver failure, and even cancer. Optimal and specific medicine delivery in various diseases, hepatectomy, shunt placement, and other surgical interventions to reduce liver damage, transplantation, optimal preservation, and revival of the donated organ all rely on a complete understanding of perfusion and mass transfer in the liver. This study aims to simulate the computational fluid dynamics of perfusion and the temporal-spatial distribution of a medicine in a healthy liver to evaluate the hemodynamic characteristics of flow and medicine transport with the purpose of more effective liver treatment. Patient-specific geometries of parenchyma and hepatic artery, portal vein, and hepatic vein vessels of a healthy liver were segmented and reconstructed from the abdominal computed tomography scan images. Mesh was generated for the comprehensive combined model using unstructured tetrahedral elements. Transient pressure values were applied as boundary conditions at the portal vein and hepatic artery inlets, and pressure outlet boundary condition was assumed at the hepatic vein outlet. Medicine injection was done through the portal vein. The liver parenchyma was assumed to be a porous medium. Finally, computational fluid dynamics (CFD) simulation was performed to investigate blood perfusion, medicine distribution, and saturation time. The velocity parameter values calculated for the hepatic artery, portal vein, and hepatic vein vessels were consistent with the physiological ranges. The mass flow rate was higher in the portal vein than in the hepatic artery, which was consistent with high perfusion through the portal vein. The portal pressure gradient was 8.53mmHg. From a pharmacokinetic viewpoint, medicine distribution in porous tissue was a heterogeneous process. Medicine distribution was higher at end-diastolic pressure than at peak-systolic pressure which showed the influence of hepatic artery flow. The tissue was saturated faster at first 40s and with decreasing porosity, saturation time decreased, and distribution improved. The right lobe included a higher number of vascular terminals due to its larger volume, and the flow rate was higher in this lobe compared to the left lobe. This showed the significant effect of the right lobe on the overall function of the body. Recirculation flow zones along hepatic artery and portal vein branches emphasized the sensitivity of downstream vessels. Rotational flow and potential vortex formation at the hepatic vein outlet may indicate a risk of plaque and clot formation in this region. The heterogeneous distribution of medicine indicated the importance of injection time in treating liver diseases. The percentage of tissue porosity affected the saturation time, so adjusting the medicine dose and injection time could be challenging in treatments.

Cavitating flow morphology determination in cavitation-on-a-chip devices based on local real-time pressure measurements

This study presents a practical approach for the characterization and control of hydrodynamic cavitation (HC) behavior in microfluidic devices by utilizing real-time static pressure measurements. Two geometrically identical micro-orifice devices were specifically designed for this purpose. Pressure measurement locations were strategically positioned along the embedded microchannel in both devices. These locations were determined as a function of the hydraulic diameter of the microchannel. Pressure measurements were simultaneously made with high-speed imaging. Particular attention was directed to the prediction and monitoring of cavitation inception, cavitating flow patterns, and cavitation development. Thus, the dynamic and complex nature of hydrodynamic cavitation in microdomains could be captured by local pressure variations along the microchannel walls. According to the results, cavitation inception and subsequent formation of twin sheet cavities could be detected by changes in local pressure values. Moreover, the analysis of local pressure variations could be employed to predict the length of sheet cavities. The findings of this study offer valuable guidelines for designing microfluidic systems involving hydrodynamic cavitation. Moreover, this study proves the potential of local wall pressure measurements as a stand-alone practical approach, which will reduce reliance on high-speed visualization. It could thus enhance the affordability and accessibility of HC-on-a-chip platforms for emerging applications, including biomedical engineering, wastewater treatment, and 2D material exfoliation.

The potential role of N-acetylcysteine as an adjuvant therapy in acute aluminum phosphide poisoning: a randomized clinical trial.

Aluminum phosphide (AP) intoxication is a life-threatening emergency with no available effective antidote. This study evaluated the efficacy and safety of N-acetylcysteine (NAC) infusion in cases of acute AP poisoning. This randomized, single-blinded, parallel-group, controlled, clinical trial enrolled 96 patients with acute AP poisoning. The patients were allocated to two groups and received either conventional treatment (control group) or conventional treatment plus NAC infusion (NAC group). The patients were subjected to full clinical evaluation, routine laboratory investigations, silver nitrate test, and evaluation of the oxidative markers, malondialdehyde (MDA) and total antioxidant capacity (TAC), at admission and after 24h treatment. The primary outcome was mortality, and the secondary outcomes were the arterial blood pressure, the length of hospital stay, and the need for intubation or mechanical ventilation. Compared to the control group, the NAC group showed significantly lower MDA (median [interquartile range (IQR)]: 4.6 [1.9-10.6] vs. 6.8 [3.5-17.4] nmol/mL, P=0.014) and higher TAC levels (median [IQR]: 0.7 [0.6-0.7] vs. 0.6 [0.6-06] mM/L, P<0.001). The mortality rate and the need for mechanical ventilation were comparable in both groups (P=0.601 and 0.505, respectively). However, the NAC group showed significant improvements of both systolic and diastolic blood pressure values (both P=0.030). The duration of hospitalization was significantly shorter in the NAC group (P=0.017). No adverse events were reported in patients who received NAC infusion. In patients with acute AP poisoning, the use of NAC mitigates oxidative stress and partially enhances clinical manifestations without inducing noticeable adverse effects.

Reconstruction of the solid–liquid two-phase flow field in the pipeline based on limited pipeline wall information

Pipeline hydraulic transportation is the primary method for transporting deep-sea mineral resources and fossil fuels. Pipeline blockage often causes excessive pressure in the pipeline, leading to pipeline breakage or even cargo leakage, which severely impacts transportation safety and can easily trigger secondary disasters. Therefore, clarifying the global flow field within pipelines, such as particle distribution, is crucial for monitoring and controlling pipeline systems. This study uses a limited number of easily measurable pipeline wall sensor pressure values as inputs of deep learning models for flow field reconstruction, with the global flow field of solid–liquid two-phase flow in the three-dimensional pipeline as the output. Three model frameworks from existing studies are summarized, and their reconstruction effects are compared. Based on this, a new framework is proposed. It expands the low-dimensional sensor pressure values to the same size as the global flow field using a pseudo-decoder and then processes them through an autoencoder. The results indicate that the new framework achieves further accuracy improvements compared to the previous three frameworks, with R2 and mean squared error reaching 0.933 and 5.13 ×10−4, respectively. Additionally, the effects of the skip connection configuration of the model, dataset size, and model learning rate, as well as the number and arrangement of pressure sensors on reconstruction accuracy, are investigated. Finally, the transferability of the model is demonstrated by reconstructing the pressure and fluid velocity fields of the pipeline two-phase flow.

Design and development of graduated compression garment with adhesive stripes using 3D virtual fitting technology

PurposeThe goal of this research is to utilize 3D virtual fitting technology to design and develop a customized full leg sleeve with graduated compression and strategically placed adhesive stripes, aiming to improve training effectiveness by restricting bending movement in the leg.Design/methodology/approachKnitted fabric and polymer adhesive film were chosen for compression garment development. The design of adhesive stripes was based on Kinesio taping method. Pattern design and 3D visualization was performed using Modaris 3D (CAD Lectra). The compression values were determined by the Laplace equation. The compression full leg sleeve with and without the adhesive stripes were fitted on the virtual mannequin in the squat position in order to determine the influence of adhesive stripes for tensile load in longitudinal direction.FindingsThe compression values in a virtual garment varied from 23.17 ± 1.94 mmHg in the ankle girth to 13.41 ± 1.50 mmHg in the thigh girth. The difference did not exceed 3 mmHg compared to the planned pressure values. The obtained result showed that purposefully placed adhesive stripes significantly increased the tensile force in the longitudinal direction of the garment in a squat position, so it may improve training effectiveness.Research limitations/implications3D virtual fitting represents the fit on a solid body form, which may affect the accuracy of compression garment simulation, as the human body is not rigid.Originality/valueThe application of 3D virtual fitting technology in creating customized and functional garments demonstrates its unique contribution to garment prototyping and product development.

Mesalazine solubility in supercritical carbon dioxide with and without cosolvent and modeling

In this study, the solubility of mesalazine in supercritical carbon dioxide with and without cosolvent was carried out for the first time at different temperatures and pressure values ranging from 308 to 338 K and 12 to 30 MPa, respectively. The determined experimental molar solubilities of mesalazine in supercritical carbon dioxide were in the range of 4.41 × 10–5 to 9.97 × 10–5 (308 K), 3.9 × 10–5 to 13.1 × 10–5 (318 K), 3.4 × 10–5 to 16 × 10–5 (328 K) and 3.3 × 10–5 to 18.4 × 10–5 (338 K). Meanwhile, the determined experimental molar solubilities in supercritical carbon dioxide using 2% dimethyl sulfoxide as cosolvent were in the range of 28.22 × 10–5 to 36.2 × 10–5 (308 K), 26.07 × 10–5 to 51.41 × 10–5 (318 K), 25.02 × 10–5 to 69.07 × 10–5 (328 K) and 25.86 × 10–5 to 82.6 × 10–5 (338 K). A novel association model was employed to simulate the solubility data of the binary and ternary systems. Various semiempirical correlations were utilized to calculate the solubility of mesalazine in supercritical carbon dioxide. The new association model was deemed the most superior model, achieving an average absolute relative deviation value of 4.13% without a cosolvent, and 3.36% when a cosolvent was included.

A Novel Method to Recognise Faults and Reefs from History Matching of Gas Production- Case Study: Mishrif Reservoir, Southern Iraq

The study area is located within the Mesopotamian Basin, the habitat of several oil fields that extract hydrocarbons from NW-SE-trending anticline formations parallel to the Zagros folding belt. The study aimed to determine if discrepancies in bubble pressure values were caused by faults or reefs using historical matching of gas production. The study revealed a distinct Mishrif reservoir seismic graph and seismic reflectors exhibiting many severe discontinuities, indicating the presence of a reef or fault. Field production data matched the fault case more consistently than the reef case during reservoir simulation, as per the well results (C37P, C43P, C46P). The history-matching simulation confirmed the two faults and rejected the reef. After seismic interpretation and historical matching, the Mishrif reservoir has two faults that were the cause of the bubble point pressure discrepancy during production operations. This method is suitable for discovering geological structures and deformations that cause bubble pressure differences for use by other researchers.

The Effect of Temulawak and Ginger on Changes in Blood Pressure in Pregnant Women and Pain Reduction in Labouring Women in BPM Suryani North Padang Lawas Regency

Hypertension in pregnancy has a significant impact on maternal and fetal health. It can lead to complications such as placental abruption, organ failure, intravenous coagulation, preeclampsia, preeclampsia to become eclampsia, risk of intrauterine development, premature birth and intrauterine death. The treatment of gestational hypertension may be either pharmacological or non-pharmacological in nature. Non-pharmacological therapy for the treatment of hypertension in pregnancy may employ the use of ginger and temulawak. This study was conducted at BPM Suryani. The population comprised all pregnant women at BPM Suryani, numbering 154. The sample consisted of pregnant women with gestational hypertension, numbering 34. The recommended dose of dried temulawak and ginger is 25 grams, boiled in 200 ml of water until 100 ml of boiled water is obtained. The boiling time is 2-5 minutes. The temulawak and ginger are administered once a day for one week. At the outset of the study, the blood pressure of pregnant women with gestational hypertension was ascertained. Following the administration of temulawak and ginger, the respondents were again subjected to monitoring of their blood pressure. The data were analysed using a statistical test, namely the t-test, which is a paired sample t-test. A significant relationship was observed between systolic and diastolic blood pressure values before and after the administration of temulawak and ginger (p-value &lt;0.05). The average difference in systolic blood pressure before and after the intervention was 5.82 mmHg with a p-value on systolic blood pressure of The p-value was 0.000 (p-value &lt;0.05) for systolic blood pressure and 0.026 (p-value &lt;0.05) for diastolic blood pressure. These findings suggest that the content of temulawak and ginger can be used in reducing blood pressure in pregnant women with gestational hypertension.

Cardiac systolic and diastolic function in relation to cardiovascular risk factor distribution: a comparison of strain-rate imaging in Russian and Norwegian populations

Abstract Background and Purpose Cardiovascular morbidity and mortality rates are high in Russia and it is likely that this reflects a similar impact on the general cardiac health of the population. The current study seeks to compare standard echocardiography and strain-based measurements between Russian and Norwegian populations, while also exploring their links to hemodynamic and risk factors. Methods This study included echocardiographic measurements of 1,192 participants from Russia, and 917 from the Study population, Norway. The sample included men and women aged 40–69 years. Normalcy, defined as the absence of hypertension or indicators of CVD, was observed in 840 individuals. We performed conventional echocardiography and analysed two-dimensional speckle-tracking longitudinal strains, including systolic, early-, and late-diastolic SR values. The study population was divided into four groups: normal, controlled hypertension, hypertensive blood pressure, and cardiac disease. Echocardiographic parameters were compared between the Russian and Norwegian populations, adjusted for age, sex, height, body mass index, blood pressure, heart rate (HR), atrial fibrillation (AF), smoking, pulmonary hypertension, and serum values for total, LDL (low density lipoprotein), and HDL (high density lipoprotein) cholesterol; triglycerides; creatinine; high-sensitivity C-reactive protein; and HbA1C. Results Russians showed a tendency towards lower longitudinal systolic functional parameters, which were most prominent in the normotensive group. However, these differences became insignificant after adjusting for parameters that influence pre- and after-loads. Russians also had a lower stroke volume, higher HR, higher left atrial volume, lower A, and higher E/A ratio, indicating a higher incidence of diastolic dysfunction in the Russian population that persisted after adjustments. Conclusion After adjusting for factors that influence cardiac function, there were no differences in systolic functional parameters between the Norwegian and Russian populations. However, differences in diastolic parameters, which persisted after adjusting for conventionally influential factors, indicated unexplained underlying causes of diastolic dysfunction in the Russian population. Figure 1 Table 1

Novel sequential proximal iliopsoas compartment block: A four-in-one block as a primary anaesthetic technique for intramedullary femoral nailing surgery: A retrospective study

Background and Aims: The fragile elderly population suffering from hip fractures presents an anaesthetic challenge; therefore, widening the armamentarium for surgical treatment should be sought. This retrospective study presents a new primary anaesthetic method for intramedullary femoral nailing (IMFN) surgery in the context of hip fracture: the sequential proximal iliopsoas compartment (SPIC) block. Methods: This single-centre retrospective study involved 25 patients aged 80 or older submitted to IMFN surgery. The patients were given a single-shot SPIC block using a total of 25 ml of ropivacaine 0.5% plus dexamethasone 8 mg administered sequentially in the proximal iliopsoas space, divided equally as per two different sites as a primary anaesthetic technique associated with moderate sedation. The outcome measure was the adequacy of the anaesthetic approach. The one-tailed Wilcoxon signed-rank test compared the preoperative numerical pain rating scale (NPRS) with the NPRS at 24 h and the pre-incision with the maximum intraoperative mean arterial pressure. Results: The patients were successfully anaesthetised, had no vasopressor consumption, had good surgical conditions, and had no complaints recorded. No tachycardia or hypertensive events were noted. No additional opioids were given. No statistically different values were observed when the pre-incisional and intraoperative mean arterial pressure values were compared (P = 0.52), and the preoperative NPRS compared with the NPRS at 24 h showed a statistically significant difference (P &lt; 0.001). Conclusion: The SPIC block combined only with moderate sedation permits adequate anaesthesia while avoiding the significant risk of neuraxial/sympathetic blockade.

The Influence of Hot Isostatic Pressing on the Mechanical Properties of Ti-6Al-4V Samples Printed Using the LENS Method

The aim of this work was to assess the influence of the parameters of the hot isostatic pressing (HIP) process and the direction of printing of Ti-6Al-4V samples made using the laser-engineered net shaping (LENS) method on strength properties. The tests were carried out using a static testing machine and a digital image correlation system. Samples before and after the HIP process were tested. The HIP process was carried out at a temperature of 1150 °C, a heating time of 240 min and various pressure values of 500, 1000 and 1500 bar. Based on the comparative analysis of the test results, it has been shown that the ability to adjust the parameters of the HIP process has a significant impact on the final mechanical properties of the samples.

Waveform characteristics in thoracic paravertebral space: a prospective observational study

Background With increased use of thoracic paravertebral block (TPVB) in thoracic surgery, many faced the challenge of locating the thoracic paravertebral space (TPVS) ultrasonographically. This observational study aimed to investigate the waveform characteristics and pressure value within the TPVS in anaesthetized patients with controlled ventilation. Methods 50 patients scheduled for elective lung surgery were enrolled. After conduction of anesthesia, all patients underwent TPVB at T4/5 and T6/7 using transverse, in-plane ultrasound guidance. A pressure transducer system with a desktop monitor was connected to the needle hub to measure pressure values and waveform characteristics in three locations: the paraspinal muscles, immediately behind the superior costotransverse ligament, and within the TPVS. Next, 15 mL of 0.33% bupivacaine was injected into each desired TPVS. After completion of the surgery, the extent of dermatomal blockade and the pain score was assessed in all patients. Results 98 typical regular respiratory waveforms with a mean pressure of ≤ 25 mmHg were detected in the TPVS of 50 patients. The sensitivity of the combined ultrasound and pressure waveform measurement technique to identify the TPVS was 95.45% (95% confidence interval, 84.527–99.445). Nontypical respiratory waveforms were present in two patients. Factors interfering with the TPVS waveform characteristics were previous thoracic surgery. Conclusion The TPVS had low pressure and showed a smooth, regular waveform pattern corresponding to respiration.