Chamber Pressure Research Articles

Teaching the distribution of pulmonary blood flow using a Starling resistor model and turbine flowmeters.

The distribution of pulmonary blood flow is uneven and can be described as a three-zone model, the West zones: zone 1 occurs whenever alveolar pressure exceeds arterial pressure; zone 2 when the arterial pressure is greater than alveolar but the alveolar pressure exceeds the venous pressure; and finally zone 3 when both arterial and venous pressures exceed alveolar pressure. Consequently, the blood flow is almost determined by the difference between the arterial and venous pressures in zone 3 and between arterial and alveolar pressures in zone 2 and ceases in zone 1. The understanding of this subject may be difficult to some medical students. Therefore, to improve the learning of this topic in our physiology course, we used a didactic model to demonstrate the core concept of flow down gradients and its application to pulmonary blood flow. We modeled a Starling resistor by placing a collapsible tube inside a hermetic chamber of variable pressure. Transparent turbine flowmeters were connected to the upstream and downstream extremities of the Starling resistor, and we generated a constant airflow with a brushless motor. By maintaining the input (arterial) pressure constant and varying the chamber (alveolar) pressure, we could simulate the three zones and demonstrate the resulting flow through the turbines. In conclusion, our demonstration using a Starling resistor model combined with visible turbine flowmeters can be used to facilitate comprehension of important concepts in physiology involving flow down gradients, such as pulmonary blood flow.NEW & NOTEWORTHY The understanding of respiratory physiology is a challenge to medical students. To improve the learning of pulmonary blood flow distribution through lung vessels in our physiology course, we modeled a Starling resistor model combined with visible turbine flowmeters. Our model can significantly improve the core concept of flow down gradients teaching and its application to West zones.

Characteristics of Side Effects in Non-Emergency Indications Using Computer-Controlled Pressurized Monoplace Hyperbaric Chambers: A Retrospective Multicenter Study

Background: Hyperbaric oxygen therapy (HBOT) involves inhaling nearly 100% oxygen in a pressurized environment and is commonly used to treat various diseases and injuries. Despite its well-known safety, HBOT is associated with side effects, with frequent middle ear barotrauma (MEB) and oxygen toxicity. Understanding the characteristics and risk factors associated with these side effects is critical for improving patient compliance and treatment outcomes. Methods: This retrospective multicenter study aimed to analyze the characteristics and factors associated with side effects during HBOT using a computer-controlled pressurized monoplace hyperbaric chamber. We conducted a retrospective observational study across the two tertiary hospitals in Korea, involving patients who received HBOT from October 2016 for one hospital and October 2017 for another hospital to June 2020. Data were extracted from electronic medical records and hyperbaric chamber logs, including patient demographics, medical history, HBOT indications, and details of side effects. Statistical analyses, including chi-square and t-tests, were used to compare variables. Results: A total of 247 patients (mean age: 59.35 ± 15.05 years, 63.56% male) were included. The most common indications for HBOT were sudden sensorineural hearing loss (27.94%) and post-graft/flap (24.29%). Hypertension (46.15%) and diabetes mellitus (39.27%) were the most frequent comorbidities. Otalgia was the most prevalent side effect (33.20%), followed by chest discomfort (2.02%) and headache (1.62%). A significant proportion of patients (11.74%) terminated HBOT due to side effects, with most pauses occurring at pressures between 1.2 and 1.4 ATA (26.67%). Side effects, particularly otalgia, significantly impact patient compliance with HBOT. Conclusions: The incidence of side effects varies by pressure level during treatment, suggesting the need for tailored strategies to minimize side effects. This study highlights the importance of patient monitoring and education to improve the safety and efficacy of HBOT in monoplace chambers.

Abstract 4135360: Eosinophilic Myocarditis: An Atypical Presentation with a Labile Course: A Case Report

Case presentation: A 64-year-old man presented with one day of chest pain. Initial evaluation showed elevated cardiac enzymes (CE) and normal eosinophil count. Electrocardiogram (EKG) was unremarkable. Transthoracic echocardiogram (TTE) showed an ejection fraction (EF) of 40% and a moderate-large pericardial effusion with signs of tamponade. Pericardiocentesis was deferred due to the lack of a safe window. Left and right heart catheterization showed no occlusive disease or chamber pressure equalization. The patient developed worsening shock, raising suspicion for myocarditis and prompting an endomyocardial biopsy (EMB). He was placed on extracorporeal membrane oxygenation (ECMO) on day 3. The EMB resulted as eosinophilic myocarditis (EM), and high dose Methylprednisolone was started. He was decannulated from ECMO on day 10. Intra-operative transesophageal echocardiogram (TEE) post-decannulation showed a normal EF without segmental abnormalities. Three hours later, a rise in CEs was noted, and EKG showed ST elevations inferiorly. TTE showed a reduced EF with multiple segmental abnormalities concerning for myocardial infarction. A repeat coronary angiogram was unremarkable. Due to the residual pericardial effusion, the patient underwent a pericardial window draining 200 cc of serosanguinous fluid. Intra-operative TEE showed an EF of 20% with no improvement after drainage. He had a cardiac arrest during the procedure and was placed back on ECMO. High-dose steroids were resumed along with intravenous immunoglobulin. Despite interventions, the patient continued to deteriorate and he ultimately expired. Discussion: EM has high mortality and a variable course, often requiring EMB for diagnosis. As in our case, about 25% of cases present without peripheral eosinophilia. Pericardial effusion occurs in 34% of cases and tamponade in 6%. A distinct feature of this case is the decompensation associated with ST elevation and segmental abnormalities, thought initially to be myocardial infarction (MI), after an initial response to steroids. While the etiology of such decompensation is unclear, relapsing EM in the setting of tapering steroids is one explanation, as myocarditis and MI can share similar clinical features. Another explanation is cardiac tamponade, which has also been reported to mimic MI and myocarditis. Air embolism from ECMO decannulation is another possibility, though air embolisms may include cerebrovascular pathology, which was not observed.

Comparison of two formulas for calculating intraocular lens in patients with angle-closure glaucoma.

This study compares the accuracy of SRK/T and Barrett Universal II intraocular lens (IOL) measurement formulas for cataract phacoemulsification combined with intraocular lens implantation in angle-closure glaucoma (ACG) patients. Prospective serial case studies were conducted. A total of 146 patients (146 eyes) with ACG complicated with cataract who underwent cataract surgery with atrial angle closure ≤180° were observed. All the patients were divided into 2 groups according to different intraocular lens calculation formula, with 73 cases in each group (73 eyes). SRK/T intraocular lens calculation formula was used in group A, and Barrett intraocular lens calculation formula was used in group B. The visual acuity, the best corrected visual acuity, intraocular pressure and central anterior chamber depth were significantly improved in 146 eyes 3 months after operation, and the differences were statistically significant. There was statistically significant difference in postoperative spherical equivalent (SE) between the 2 groups (t = 2.147, P = .033), and there was statistically significant difference in preoperative expected refraction between group A and postoperative SE (t = 4.221, P < .001). There was no significant difference between preoperative expected diopter and postoperative SE in group B (t = 1.857, P = .065). The difference in absolute predicted error between the 2 groups was statistically significant (t = 4.929, P < .001). Axis length was negatively correlated with SRK/T formula and Barrett Universal II formula absolute refractive error value (ME) (group A: r = -0.740, P < .001; group B: r = -0.532, P < .001), there was A significant negative correlation between absolute refractive error value and anterior chamber depth in both groups (group A: r = -0.382, P = .001; group B: r = -0.358, P = .002). The cataract phacoemulsification combined with intraocular lens implantation is safe and effective for ACG patients with cataract. For such patients, the Barrett Universal II intraocular lens measurement formula may be more accurate after surgery.

A Comparative Study on Laser Cutting Performance with Varying Speeds at 10 M Underwater

Despite the dismantling structures that are submerged to significant depths of water during the decommissioning of nuclear power plants, there is limited research on deep-water laser cutting processes. A self-designed pressurized chamber was used in this study and successfully conducted the world’s first laser cutting experiment in a simulated 10 m water depth environment. laser cutting was performed in a 10 m underwater environment, and the cutting efficiency was compared to that observed in a 1 m underwater environment. Therefore, A 100 mm thickness of 304 stainless steel was successfully cut underwater, and the highest cutting speed of 100 mm/min was achieved. The result indicates that, as the cutting speed increased during underwater laser cutting, both the heat input and the mass flow rate of the assist gas decreased, resulting in a narrower rear kerf width and an ineffective evacuation of the molten metal.

Effect of detachment on Magnum-PSI ELM-like pulses: direct observations and qualitative results

Abstract Conditions similar to those at the end of the divertor leg in a tokamak were replicated in the linear plasma machine Magnum-PSI. The neutral pressure in the target chamber is then increased to cause the target to transition from an attached to a detached state. Superimposed to this steady state regime, edge localised mode (ELM)-like pulses are reproduced, resulting in a sudden increase in plasma temperature and density, such that the heat flux increases transiently by half an order of magnitude. Visible light emission, target thermography, and Thomson scattering are used to demonstrate that the higher the neutral pressure the more energy is removed from the ELM-like pulse in the volume. If the neutral pressure is sufficiently high, the ELM-like pulse can be prevented from affecting the target and the plasma energy is fully dissipated in the volume instead (ID 4 in table 1). The visible light images allow the division of the ELM-plasma interaction process of ELM energy dissipation into 3 ‘stages’ ranging from no dissipation to full dissipation (the target plasma is detached). In the second publication related to this study, spectroscopic data is analysed with a Bayesian approach, to acquire insights into the significance of molecular processes in dissipating the plasma energy and particles.

Water status assessment in grapevines using plant electrophysiology

Traditional methods for assessing vine water status, such as the Scholander pressure chamber, are time-consuming, punctual and labour-intensive. The development of alternative methods which are accurate, reliable and can provide real-time information on vine water status is a necessity for farmers all over the world. This study proposes the use of plant electrophysiology as a novel approach for real-time water status assessment in grapevines. We conducted four climate chamber experiments with potted grapevines under different irrigation regimes. Various morphological and physiological assessments were performed in parallel with electrophysiological measurements to correlate classic water status assessment methods with plant electrophysiological signals. Two machine learning approaches based on classification and regression were employed to train the prediction models. Results obtained from both models indicate significant differences in irrigation status between well-watered and water-deficit plants, with the latter showing reduced growth and physiological activity, confirming the water stress status of the plant. While the binary classification model successfully differentiates between well-watered and water-deficit plants, its practical use is limited. Therefore, a regression model was developed to directly predict predawn leaf water potential. To the best of our knowledge, this is the first time that electrical signals are correlated with vine water potential measurements. The findings presented here thus provide a promising new tool for future real-time and remote monitoring of vine water status to manage irrigation and adapt agronomic strategies. Nevertheless, validation and optimisation of the models are still necessary, particularly under field conditions.

Modeling and Validation of the Sealing Performance of High-Pressure Vane Rotary Actuator

The EHRA (Electro-Hydraulic Rotary Actuator), using a vane rotary actuator, has the advantages of a high torque density and integration and is expected to become a joint actuator for robots. This research focuses on the sealing characteristics of various parts of a vane rotary actuator. The average Reynolds equation was used to analyze the leakage characteristics at the gap. A detailed theoretical analysis was conducted on the internal leakage mechanism of a vane rotary actuator using an X-ring as the dynamic seal for the rotor vane. According to the path of internal leakage, different sealing forms are considered as a series or parallel, and the Newton iteration method is used to obtain the total internal leakage characteristics of a vane rotary actuator. It was also considered that the deformation of the vane rotary actuator caused a thicker gap, leading to an increase in internal leakage. The calculation results are consistent with the experimental data. The analysis results indicate that when estimating the internal leakage of a vane rotary actuator, it is necessary to take the pressure of the high-pressure chamber and output shaft position as inputs. This research provides a reference for an analysis of the method of internal leakage for vane rotary actuators. It provides theoretical support for designing a vane rotary actuator with more minor internal leakage and a higher volumetric efficiency.

Thermal erosion test of ZrB2-based ceramics

The thermal erosion of a set of bulk fully dense and 10% porous ZrB2-based ceramics of different composition were machined as sharp wing and tested in an air-fuel mixture flow formed by mixing air and kerosene with an oxygen content ~ 5wt%. The resulting pressure in the combustion chamber was 0.8MPa and the flow temperature was 1500°C. Microstructural analyses upon the tests evidenced that criteria for material success include high density and high thermal conductivity, along with formation of stable compounds. These results were supported by numerical simulation. Among all tested materials, only ZrB2-15 MoSi2 (ZM) ceramics met all the requirements and successfully survived the thermal erosion test up to 1200sec.

Synthesis of Sn-catalyzed Ge nanowires and Ge/Si heterostructures via a gradient method

In this study, we investigate the growth of Ge nanowires (NWs) using a gas supply gradient method during plasma-enhanced chemical vapor deposition (PECVD), focusing on the effects of GeH4 partial pressure and total chamber pressure on NWs morphology. By adjusting either the GeH4 flow rate or the total pressure, we explored a gradient method to manipulate the growth process. Scanning electron microscopy (SEM) images revealed that, even with constant GeH4 partial pressure, variations in total pressure significantly influenced NWs diameter and structure. Furthermore, elemental mapping and compositional analysis demonstrated the presence of a Ge/Si heterostructure with a Sn catalyst at the apex and an amorphous Si layer encapsulating the NW surface.

Development and Diagnostic Study of the RF nitrogen Atom Source

With the development of thin film technology, particularly the increasing demand for research on group III nitride materials, the need for N ions has significantly increased. A wider and more efficient RF nitrogen atom source specifically designed for nitride film growth has been developed. To evaluate the nitrogen atom density from the RF nitrogen source, a global model of RF nitrogen gas discharge plasma was created. This model was calibrated by measuring the emission spectrum of RF nitrogen gas discharge, and the relationships between nitrogen atom density and actual working pressure, power, and discharge chamber size were determined. It was found that the nitrogen atom density increases with increasing power and initially increases with pressure before decreasing. Finally, the nitrogen atom density was determined, achieving an 18% nitrogen atom dissociation rate and a nitrogen atom density of 5×1012/cm³ at an RF power of 400 W. This density is significantly higher than that of nitrogen ions, indicating that this is a nitrogen atom source with high purity.

Direct Shear Testing Apparatus for Saturated Rock Joints

Abstract A novel shear test apparatus has been designed and built to test saturated jointed rock specimens under normal and shear loading, capable of housing seismic transducers to monitor simultaneously the mechanical and geophysical response of the rock joints during shear. The system comprises a sealed pressure chamber and a biaxial compression frame. The internal dimensions of the chamber are 177.8 mm × 228.6 mm × 381.0 mm to accommodate a rock specimen with dimensions 152.4 mm × 127.0 mm × 50.8 mm. The chamber is made of aluminum to reduce its weight and is designed to sustain a maximum chamber pressure of 10 MPa, which is considered sufficient to be able to saturate a wide number of rocks. Structural calculations of the chamber are performed with the finite element method (FEM) software, ABAQUS, with the criterion of a maximum deflection of 1 mm at maximum chamber pressure, which is small enough to prevent the loss of seal between the loading shafts and the chamber. The rocks used in the study are Indiana limestone and Sierra White granite. B-value tests conducted on cylindrical specimens of the rocks placed inside the chamber show that the back pressures required to achieve saturation are 3.5 MPa for Indiana limestone and 5.0 MPa for Sierra White granite. The chamber performance has been evaluated by comparing the changes of volume of the chamber at different pressures, measured in the laboratory, with those predicted with ABAQUS. The successful completion of a number of repeatable direct shear tests, on tensile-induced rock joints in dry and saturated conditions specimens, has further established the correctness of the chamber design and its operation.

Effect of application of ozone at low-pressure on the technological properties, phenolic compounds, and antioxidant capacity of common beans during storage

The objective of this study was to assess the effects of low-pressure ozone treatment on the technological quality, phenolic compounds, and antioxidant capacity of common beans (Phaseolus vulgaris L.) during storage. Samples of 5.0 kg of dry beans were exposed to ozone in a hypobaric chamber with an internal volume of 70 L. Ozone was injected until the internal chamber pressure reached 100000 Pa, with an inlet concentration of 61.37 mg L−1 and flow rate of 1.0 L min−1. Ten cycles of ozone injection were adopted. Oxygen was used in control treatment. The effect of the treatments on the grain quality was assessed over storage for 180 days. Ozone did not affect the percentage composition of the dry beans, which exhibited 18.76% of protein, 11.66% of moisture content, 3.44% of minerals, 1.32% of lipids, and 64.51% of carbohydrates. A significant difference (p < 0.05) between the treatments and the control was noticed in total titratable acidity. The luminosity (L*) and hue (h*) of the grains were not altered by ozonation. Ozone had a significant effect (p < 0.05) on the phenolic content of the dry beans but no significant effect (p > 0.05) on their antioxidant capacity. The phenolic compounds content and antioxidant capacity decreased over storage in all treatments. Ozone application at low pressures proved a promising technology for controlling insect pests and promoting fungal decontamination without altering dry bean quality throughout storage.

Mucilage facilitates root water uptake under edaphic stress: first evidence at the plant scale.

Mucilage has been hypothesized to soften the gradients in matric potential at the root-soil interface, hereby facilitating root water uptake in dry soils and maintaining transpiration with a moderate decline in leaf water potential. So far, this hypothesis has been tested only through simplified experiments and numerical simulations. However, the impact of mucilage on the relationship between transpiration rate (E) and leaf water potential (ψleaf) at the plant scale remains speculative. We utilized an automated root pressure chamber to measure the E(ψleaf) relationship in two cowpea genotypes with contrasting mucilage production. We then leveraged a soil-plant hydraulic model to reproduce the experimental observations and inferred the matric potential at the root-soil interface for both genotypes. In wet soil, the relationship between the leaf water potential and transpiration rate (E) was linear for both genotypes. However, as the soil progressively dried, the E(ψleaf) relationship exhibited nonlinearity. Genotype with low mucilage production exhibited nonlinearity earlier during soil drying, i.e. in wetter soil conditions, (soil water content < 0.36cm3 cm-3) compared to Genotype with high mucilage production (soil water content < 0.30cm3 cm-3). The incidence of nonlinearity was concomitant with the decline in matric potential across the rhizosphere. High mucilage production attenuated water potential diminution at the root-soil interface with increased E. This shows, for the first time at the plant scale, that root mucilage softened the gradients in matric potential and maintained transpiration in drying soils. The model simulations indicate that a plausible explanation for this effect is an enhanced hydraulic conductivity of the rhizosphere in genotype with higher mucilage production. Mucilage exudation maintains the hydraulic continuity between soil and roots and decelerates the drop in matric potential near the root surface, hereby postponing the hydraulic limitations to transpiration during soil drying.

Water Stress Adaptations by Rhododendron arboreum Smith in The Himalayan Treeline Environment

Drought is amongst the most important climatic events which can severely impact natural ecosystems. The under-canopy Indian Himalayan tree species are less studied on water stress in harsh climatic conditions. Rhododendron arboreum is an ecologically and economically important tree species and distributed between 1500–3500 m asl in the Himalayan ecosystems. In this study, we have tried to assess the water stress adaptations by R. arboreum near the treeline ecotone located at 30°11´02˝N and 79°39´36˝E between 3100 and 3500 m asl elevation. Water potential (Ψ) was measured using a Pressure chamber and leaf conductance with the help of AP4 porometer. Soil moisture (Sm) across the depths was highly variable (p&lt;0.05). The pre-dawn water potential (ΨPD) of R. arboreum tree varied between -0.12 and -0.91 MPa. ANOVA showed that the ΨPD of R. arboreum seedlings varied significantly across the years, seasons, and sites (p&lt;0.05). The decline in osmotic potential at full turgor (Ψπ100) was -1.18 to -1.20 MPa in trees and -1.42 to -1.72 MPa in seedlings. The morning leaf conductance (gwAM) of R. arboreum trees ranged from 58.00 to 271.68 m mol m-2 sec-1. Correlation showed that the maximum leaf conductance in R. arboreum trees was observed when the ΨPD was -0.5 to -0.9 MPa. Water uptake function in plants is generally affected by winter frost which can change the Ψ, osmotic potential, and leaf conductance of plants. The ΨPD in the species was relatively high across all seasons in the treeline areas to disrupt physiological activities.

Fuel Ignition in HTP Hybrid Rockets at Very Low Mass Fluxes: Challenges and Pulsed Preheating Techniques Using Palladium-Coated Catalysts

In a worldwide scenario which sees an increasing number of small satellite launches, novel mission concepts may be unlocked providing the spacecrafts with the very precise and rapid maneuvering capability that electric thrusters cannot guarantee. In this context, chemical thrusters appear to be a possible solution. This work aimed to experimentally study and solve the problem of ignition for 10 N hybrid rockets based on hydrogen peroxide. Firstly, the study analyzed the performance of a monopropellant engine capable of functioning as a hybrid injection system. In particular, the effects of the liquid mass injected, the initial temperature, and the supply pressure on the pulsed engine performance were experimentally investigated. The injected mass showed a greater impact on the performance with respect to the starting chamber temperature and injection pressure. This thruster also showed a good potential for space applications. In the second part of the work, the objective was to find an ignition procedure that reduced propellant consumption and eliminated the need for a glow plug. This is important because the electrical power consumption in real applications significantly affects other subsystems and is undesirable for chemical engines. Different ignition procedures were tested to emphasize their respective advantages and disadvantages, and the findings indicated that the concept of pulsed preheating is feasible with only a small amount of propellant consumption, while substantially decreasing the ignition duration from approximately 45 min to a maximum of just 3 min. Finally, similar ignition procedures were adopted using different fuels. The results showed that PVC and ABS, under the same operating conditions, ignite more easily than HDPE, which requires an oxidizer consumption approximately double that of the other two fuels. Considerations about the effect of chamber pressure and oxidizer mass flow rate on engine ignition were also included.

Prediction of TBM cutter wear in heterogeneous ground under high ambient pressure

To prevent tunnel face collapse in heterogeneous ground, the applied face pressure in the excavation chamber can be increased to stabilise the tunnel face, which may hinder cutter rotation during tunnel boring machine (TBM) tunnelling. This study proposes a TBM cutter wear prediction model that considers the impact of the variation in the cutter normal force on the cutterhead owing to the high applied face pressure and low penetration rate. First, the cutter motion mode in heterogeneous ground is investigated. The cutter is found to slide when cutting soft rock based on an analysis of the field data. The evolution process of the cutter wear morphology under heterogeneous ground conditions is summarised. A method for calculating the cutter normal force when the cutter slides on the tunnel face is proposed by referring to the cutting mechanism of the drag bits. The cutter hardness is measured on-site using a portable hardness tester. A semi-empirical model considering the variation in the cutter normal force on the cutterhead is proposed to predict the cutter wear in heterogeneous ground. Wear prediction is compared with other predictive models and field data for validation, and the discrepancies between the different models are discussed. The results show that the proposed model is effective for predicting TBM cutter wear under complex geological conditions.

Statistical analysis of predictors of effectiveness of complex physiotherapeutic treatment in patients with involutional skin changes

BACKGROUND: Analysis of predictors of the effectiveness of various treatment regimens for diseases, as well as the correction of involutionary processes in the human body, is increasingly becoming a standard in scientific medical research. The technology for identifying them traditionally includes the use of correlation and regression analysis, as well as the principles of correlation adaptometry, which makes it possible to approach the solution of this problem from the position of system analysis. AIM: Analysis of predictors of the effectiveness of correction of involutive skin changes in middle-aged and older women with metabolic syndrome using various therapeutic regimens, including hyaluronic acid laser phoresis and the use of transcranial magnetic therapy in combination with oxygen barotherapy. MATERIALS AND METHODS: The study was carried out with the participation of 60 patients from middle and older age with involutional changes in the skin against the background of metabolic syndrome. All patients were divided into 2 groups using simple fixed randomization. The first group (comparison, 30 patients) received laser phoresis of hyaluronic acid in the form of a 1.5% sodium hyaluronate gel using a laser and laser-vacuum therapy device LAZMIK. Patients of the second group (main group, 30 patients) were prescribed combined physiotherapy. For transcranial magnetic therapy, the Amo-Atos device with the Headband attachment was used, and oxygen barotherapy was carried out in single pressure chambers of the Oka-MT or Irtysh-Shch1 type under a pressure of 2 atm for 1 hour. RESULTS: It was found that in the initial state, the quality of life of patients with involutional changes in the skin against the background of metabolic skin syndrome was largely determined by the presence of pathological correlation galaxies that integrate changes in the condition of the skin, metabolic disorders, indicators of oxidative stress and microhemodynamics, and the activity of proinflammatory cytokines. At the same time, the leading role in the deterioration of the quality of life belonged to the age of the patients, the insulin resistance index, transepidermal water loss and microcirculation indicator. However, predictors of effectiveness varied across different treatment regimens. With laser phoresis of hyaluronic acid, its effectiveness increases in younger women with minimal involutional manifestations of skin aging, tested for the condition of the skin, while combined physiotherapy is also most effective in women with a low average age limit, with minimal manifestations of metabolic syndrome and inflammatory processes, as well as against the background of high activity values of one of the enzymes of antioxidant protection ― superoxide dismutase. CONCLUSION: The results obtained convincingly prove the effectiveness of combination therapy in correcting involutive skin changes in middle-aged and older women due to metabolic syndrome, which is comparable in a number of parameters to the effectiveness of hyaluronic acid laser phoresis. At the same time, predictors of effectiveness depend on the characteristics of the mechanisms of therapeutic action of the treatment regimens used, which allows for a more correct approach to the choice of personalized treatment methods.

The inactivation of Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes using isochoric freezing in raw milk and carrot juice

Isochoric freezing is a novel food preservation method that may maintain the quality and safety of products by simultaneously applying low temperatures and high pressures. This work aims to determine whether isochoric freezing can improve food safety by inactivating Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes in raw milk and carrot juices. Raw milk and carrot juice samples were inoculated with cocktails of either STEC or L. monocytogenes and then subjected to isochoric freezing conditions in pressurized chambers set at −5, −10, and −15 °C and treated for 1, 5, 7, or 10 days. Following treatment, the product was sampled for surviving pathogens. The results demonstrated that a 5-log reduction of both STEC and L. monocytogenes can be achieved for raw milk and carrot juice without adversely affecting quality. For STEC inoculated in raw milk, both the linear and Weibull models suggest that 10 days is required to achieve 5-log reduction at −10 °C. Decreasing the temperature to −15 °C led to accelerated log reduction but induced phase separation in the milk. Listeria in raw milk demonstrated a biphasic reduction, indicating 1.3 days is required for a 5-log reduction at −10 °C. In comparison, pathogens demonstrated faster log reduction in carrot juice due to its intrinsic properties. The survival curves for STEC-inoculated carrot juice demonstrated that the 5-log reduction times were 6.9 days at −10 °C and 3.8 days at −15 °C. L. monocytogenes in carrot juice required 1.5 days at −10 °C for a 5-log reduction and was eliminated (7 log cfu/ml) within 24 h at −15 °C. Isochoric freezing could be an option for milk and carrot juice processors wishing to improve food safety without applying heat. This method is not a one-size-fits-all solution, and the time and temperature will need further optimization depending on the target pathogen and intended commodity.

Influence of Synthesis Parameters on Structure and Characteristics of the Graphene Grown Using PECVD on Sapphire Substrate.

The high surface area and transfer-less growth of graphene on dielectric materials is still a challenge in the production of novel sensing devices. We demonstrate a novel approach to graphene synthesis on a C-plane sapphire substrate, involving the microwave plasma-enhanced chemical vapor deposition (MW-PECVD) technique. The decomposition of methane, which is used as a precursor gas, is achieved without the need for remote plasma. Raman spectroscopy, atomic force microscopy and resistance characteristic measurements were performed to investigate the potential of graphene for use in sensing applications. We show that the thickness and quality of graphene film greatly depend on the CH4/H2 flow ratio, as well as on chamber pressure during the synthesis. By varying these parameters, the intensity ratio of Raman D and G bands of graphene varied between ~1 and ~4, while the 2D to G band intensity ratio was found to be 0.05-0.5. Boundary defects are the most prominent defect type in PECVD graphene, giving it a grainy texture. Despite this, the samples exhibited sheet resistance values as low as 1.87 kΩ/□. This reveals great potential for PECVD methods and could contribute toward efficient and straightforward graphene growth on various substrates.