High Pressure Pulses Research Articles

The Impact of Smoking on Arterial Stiffness in Young Adults: A Prospective Analysis.

Arterial stiffness is a crucial factor in the pathogenesis of cardiovascular disease, often associated with aging. However, the impact of smoking on arterial stiffness is frequently underestimated. This study aims to investigate the intricate relationship between smoking and arterial stiffness to advance our understanding of and therapeutic approaches to cardiovascular health. A prospective analysis was conducted from January to July 2024, focusing on arterial stiffness parameters in a cohort of students from the Carol Davila University of Medicine and Pharmacy. Participants were categorized as smokers or non-smokers based on self-reported smoking status. The study endpoints included correlations between high pulse wave velocity, elevated peripheral and central systolic blood pressure, increased peripheral and central pulse pressure, and smoking status. These markers were assessed using an arteriograph device measuring the time difference between the initial forward pulse wave and the reflected pulse wave in the brachial artery to indirectly estimate the PWV using oscillometric pulsations. Our investigation, involving 102 young individuals aged 20 to 26 (69 females, 33 males), revealed that smokers exhibited significantly higher average values of arterial stiffness indicators compared to non-smokers. Current smokers had higher mean systolic blood pressure (130.65 vs. 123.05 mmHg), higher mean peripheral pulse pressure (53.19 vs. 45.64 mmHg), higher mean central pulse pressure (33.66 vs. 29.69 mmHg), and higher mean pulse wave velocity (5.27 vs. 5.03 m/s). The utilization of arterial stiffness markers as predictive tools offers opportunities for personalized treatment strategies, potentially enhancing cardiovascular health outcomes.

Barometric pressure monitoring and multiple applications based on pulsed airflow-driven silver nanoparticles/copper foam triboelectric nanogenerators

Abundant high-pressure exhaust gas is generated during industrial production processes. The direct release of this exhaust gas not only leads to energy dissipation but also increases the accident risk. Therefore, it is essential to utilize and monitor high-pressure exhaust gas. This study designed a triboelectric nanogenerator (TENG) driven by high-pressure pulse airflow to realize energy harvesting and pressure monitoring at the gas–solid interface. The silver nanoparticles (Ag NPs)/ copper foam (CF)-based TENG (SC-TENG) were fabricated and exhibited excellent output characteristics. Compared to the copper-based TENG, the short-circuit current and output power were increased by 68.72 % and 63.34 %, respectively, which could directly light up 111 light-emitting diodes (LEDs). Furthermore, the effects of pipeline mateal, valve material, preparation environment (AgNO3 concentration), and air pressure were investigated to optimize the electric output of SC-TENG. The SC-TENG exhibited excellent pressure sensing capabilities and could be applied for rapid and sensitive long-term monitoring. Based on this, a wireless high-pressure warning system was designed to realize signal transmission and safety pre-warning. Lastly, a novel information encryption method based on pulse airflow was developed, and its potential applications in various fields were discussed. This work not only proposes a utilization and solution strategy for high-pressure exhaust gas issues to realize the principle of “turning waste into treasure”, but also provides valuable insights into the extended applications of TENG technology.

Timber DNA release using focused ultrasound extraction (FUSE) for genetic species identification

The use of genetic data for timber species and population assignment is a powerful tool for combating the illegal timber trade, but the challenges of extracting DNA from timber have prevented the routine use of genetics as a supply chain management tool. To overcome these challenges, we explored the feasibility of focused ultrasound extraction (FUSE) for rapid DNA release from timber. Using high-pressure ultrasound pulses, FUSE generates a cavitation bubble cloud that disintegrates samples into acellular debris, resulting in the mechanical release of DNA. In this work, FUSE was applied to white oak (Quercus alba) timber shavings to test the feasibility of using FUSE for timber DNA extraction for the first time. Results showed that FUSE processing disintegrated the tissue samples and released significant quantities of DNA. After five minutes of tissue processing DNA quantities of 0.21 ± 0.02 ng/mg, 0.99 ± 0.32 ng/mg, and 0.14 ± 0.01 ng/mg, were released from medium, coarse, and combination shaving groups, respectively. Amplification and sequencing of regions within the matK and rbcL chloroplast genes confirmed that the quality of DNA prepared with FUSE was suitable for PCR and short-read sequencing applications. Overall, these results show that FUSE can serve as a DNA sample preparation method capable of releasing high-quality DNA from timber in a fraction of the time required by conventional extraction methods. Based on the improved efficiency of DNA release with FUSE, ongoing work aims to develop this technology into portable systems that can be used to rapidly prepare timber samples for genetic species identification.

Ultrasound Therapy With High-Pressure Pulses Is Effective to Reduce the Effects of Collagenase-Induced Tendinopathy in Rat's Achilles Tendon

ObjectiveWe propose an ultrasonic treatment for collagenase-induced tendinopathy in rat's Achilles tendon using pulses with a low number of cycles, high acoustic pressure and very low duty cycle. MethodsTwenty rats were used to perform the experiment. Four experimental groups of calcaneal tendons were studied: control (n = 6), sham (n = 4), collagenase-induced tendinopathy (n = 8) and ultrasound-treated collagenase-induced tendinopathy (n = 8). Surgical intervention was performed to expose the tendons prior to collagenase injection. A 1 MHz ultrasonic tansducer with a focusing lens was used. Ultrasonic treatments were used with an average total treatment time of 2.5 min, 20-cycle pulses, pressure amplitude p = 7 MPa, and 0.02% duty cycle. Histopathology of the samples was performed to evaluate nuclear density, acute inflammation, and signs of neovascularization. Collagen (types I and III), elastic fibers, and glycosaminoglycans were also analyzed. ResultsNo tendon involvement was found by the surgical process. Ultrasonic treatment is safe, as it does not affect healthy tendons. When collagenase infiltrated animals were treated with US, a clear predominance of type I collagen fibers and a similar collagen ratio profile to that observed in the control and sham groups was observed, with a higher density of elastic fibers compared to the control and sham groups and a significant increase in the density of glycosaminoglycans. ConclusionThe ultrasound treatment proposed reduces the effects of the artificial collagenase lesion to reach the basal level after 45 d.

Study on partial load vortex and pressure pulsation characteristics of Francis turbine

Abstract Under partial load condition of the Francis turbine, problems such as hydraulic vibration, noise, and high amplitude pressure pulsation that endanger the safe and efficient operation of the unit are inevitable during the transient process. Based on dynamic grid technology and CFD technology, unsteady numerical simulation was conducted for the closing process of the active guide vane from 54% opening to 38% opening, and the evolution characteristics of internal vortex and pressure pulsation were analyzed. The results show that there is always a vortex structure at the crown of the runner during the transition process of variable load. Because of the vortex structure, a “banded” low-pressure zone appears on the suction surface of the blade, which gradually approaches the lower ring of the runner as the vortex structure develops. The analysis of the pressure signal in the runner region shows that the pressure coefficient on the suction surface fluctuates greatly due to the influence of the distribution position of the vortex structure, and the evolution of the vortex structure from continuous to local fracture will lead to a sudden increase of the pressure coefficient. In addition, the frequency components within the runner domain include the frequency of the movable guide vanes passing through the blade and the low-frequency components caused by the evolution of eddy currents within the runner.

Research on Closed Loop Control of Pulse Power Discharge Frequency

Abstract During the process of improving unconventional oil and gas reservoirs using electric pulse stimulation, to achieve optimal effects in terms of rock matrix pore dilation and fracturing, it is required that the electric pulse frequency is close to the inherent frequency of the reservoir. In the context of research focused on open-loop control for the discharge frequency of a high-pressure pulse device, the topological structure and mathematical model of the high-pressure pulse discharge device have been established. The analysis of current variations during the discharge process has been conducted. A closed-loop control strategy based on the super-helix sliding mode control has been proposed, along with the introduction of a nonlinear extended state observer. This strategy aims to achieve closed-loop control of the discharge frequency, and its effectiveness and control performance have been verified through simulation.

Pulse pressure is associated with decline in physical function in older adults

ObjectivesThis study examined the associations between pulse pressure, hypertension, and the decline in physical function in a prospective framework. Study designThe Healthy Aging Longitudinal Study tracked a group of Taiwanese adults aged 55 or more over an average of 6.19 years to assess pulse pressure and decline in physical function, including in handgrip strength, gait speed, and 6-min walking distance, at baseline (2009–2013) and in the second phase of assessments (2013−2020). Main outcome measuresPulse pressure was calculated as the difference between systolic and diastolic blood pressure values. Weakness, slowness, and low endurance were defined as decreases of ≥0.23 m/s (one standard deviation) in gait speed, ≥5.08 kg in handgrip strength, and ≥ 57.73 m in a 6-min walk, as determined from baseline to the second phase of assessment. Linear and logistic regressions were employed to evaluate the associations between pulse pressure, hypertension, and decline in physical function. ResultsBaseline pulse pressure was associated with future handgrip strength (beta = −0.017, p = 0.0362), gait speed (beta = −0.001, p < 0.0001), and 6-min walking distance (beta = −0.470, p < 0001). In multivariable models, only handgrip strength (beta = −0.016, p = 0.0135) and walking speed (beta = −0.001, p = 0.0042) remained significantly associated with future pulse pressure. Older adults with high systolic blood pressure (≥140 mmHg) and elevated pulse pressure (≥60 mmHg) exhibited a significantly increased risk of weakness (odds ratio: 1.30, 95 % confidence interval: 1.08–1.58), slowness (1.29, 1.04–1.59), and diminished endurance (1.25, 1.04–1.50) compared with the reference group, who exhibited systolic blood pressure of <140 mmHg and pulse pressure of <60 mmHg. ConclusionsAmong older adults, pulse pressure is associated with a decline in physical function, especially in terms of strength and locomotion.

Traumatic Brain Injury and Conversion Disorder in a Veteran’s Atypical Presentation

IntroductionTraumatic brain injury (TBI) induces cognitive and behavioral changes due to environmental impacts on brain tissue.ObjectivesHighlighting the atypical TBI presentation challenging conventional diagnostics and obscured by conversion disorders.MethodsA 36-year-old male veteran, injured by a sniper rifle in 2011, presented with right ear tinnitus and monthly, unresponsive right hemicranial headaches. Seizures occurred every two weeks with no reported loss of consciousness or sensation. The gunshot wound to the neck in 2011 prompted emergency intervention, with entry and exit wounds located in the posterior lateral neck. Post-injury symptoms comprised hearing loss, tinnitus, restricted neck movement, and weakness in the right arm. Seizures persisted, accompanied by numbness and neck movement. Management included physical therapy, hyperbaric oxygen therapy (improving weakness but not tinnitus), and administration of piracetam (2400 mg/day), sertraline (100 mg/day), and ginkgo biloba (2400 mg/day). Psychiatric consultation suggested a diagnosis of “conversion disorder.”ResultsNeuropsychological Evaluation: Raven Standard Progressive Matrices Test showed borderline impairment. Psychiatric Evaluation noted monotonous mimics, occasional depersonalization, reduced emotional involvement, and slowed psychomotor activity. Elevated trait anxiety was observed per the State-Trait Anxiety Inventory. Neurological Examination identified left arm weakness and impaired resting balance. Imaging Findings: F18-FDG PET/CT Scan at 1 year post-GSW showed hypermetabolism in the right frontal lobe, and at 3.5 years post-GSW demonstrated decreased glucose metabolism in the bilateral cerebellar cortex, temporal lobe, and bilateral parietal lobe.ConclusionsA high-kinetic-energy bullet passed through the right lateral base of the neck without causing apparent brain damage. Proposed is the generation of upward pressure waves in neck tissues through the transmission of kinetic energy, compressing and displacing soft tissues toward the skull. Gunshot injuries create cavities, forming high-pressure waves capable of damaging distant brain regions, leading to TBI such as crush injury, edema, and myelin and axonal damage (Courtney &amp; Courtney, 2007). Microscopic brain damage, undetectable by current imaging, may only surface during autopsy (Yilmaz &amp; Pekdemir, 2007). Rat studies after primary blast injuries reveal brain alterations, highlighting that high-pressure pulses can cause neuronal damage, potentially yielding related symptoms (Cernak et al., 2001). The patient’s atypical symptoms, combined with the initial conversion disorder hypothesis, underscore the need for a diagnostic paradigm shift to differentiate traumatic brain injury from other potential misnomers.Disclosure of InterestNone Declared

Abstract 1456: First successful engraftment of human liver cancer cell line in highly robust immunocompromised porcine model to test the tumor ablation efficacy by histotripsy

Abstract Liver tumor, commonly called Hepatocellular carcinoma(HCC), is the most common type of primary liver malignancy. It is the fourth leading cause of cancer-related deaths. Late diagnosis, location of the tumor, tumor burden, and metastases makes liver tumor very challenging to treat by liver transplantation, surgical procedures, and other ablation techniques like cryoablation and thermal ablation. Also, the absence of a preclinical animal model makes it challenging to develop and explore the feasibility of treatment modalities. Histotripsy is a non-invasive, non-ionizing, non-thermal, image-guided focused ultrasound ablation treatment method that uses high-pressure pulses to create acoustic cavitation, a “bubble cloud,” at the target. The bubble cloud expands and collapses, which ablates the tissue into an acellular homogenate. Pigs are ideal animal models as they closely resemble human anatomy and are significant in improving the translation to human patients. This study aimed to establish the feasibility of successfully ablating liver tumors by histotripsy using an immunocompromised porcine model to generate HepG2 human liver cancer cell line tumors in the liver of the immunocompromised pigs. The orthotopic porcine model was established using RAG2/IL2RG double knockout immunocompromised pigs. HepG2 cells were injected orthotopically into the liver of immunocompromised pigs. Three weeks after the injections, CT images and necropsy indicated successful engraftment and growth of liver tumors in the pigs. The ultrasound images and post-histotripsy treatment histology images showed confirmed ablation zones in the liver. Therefore, in conclusion, our preliminary results in the study could demonstrate, for the first time, a highly robust model of human liver cancer in a large animal model. Soon, we plan to conduct more such studies and explore all the possible utilities of these immunocompromised porcine models to develop therapeutic strategies to increase the efficacy of liver tumor ablation by histotripsy. Citation Format: Tamalika Paul, Khan M. Imran, Jessica Gannon, Brie Trusiano, Kristin Eden, Hannah Ivester, Madeline Mott, Manali Powar, Michael Edwards, Christopher Byron, Sherrie Clark-Deener, Kiho Lee, Eli Vlaisavljevich, Irving Coy Allen. First successful engraftment of human liver cancer cell line in highly robust immunocompromised porcine model to test the tumor ablation efficacy by histotripsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1456.

The Effects of Noise Pollution on the Prevalence of High Blood Pressure and Abnormal Pulse Rate on Workers in select Industries in Nnewi

This study investigates the impact of noise pollution on the prevalence of high blood pressure and abnormal pulse rate among workers in selected industries in Nnewi, Nigeria. Utilizing a cross-sectional design, the research encompassed 250 workers exposed to varying levels of noise pollution. Data on blood pressure, pulse rate, and noise exposure were collected and analyzed using descriptive and inferential statistics. The findings reveal a significant correlation between prolonged exposure to high noise levels and increased instances of high blood pressure and abnormal pulse rates among the participants. These outcomes underscore the critical need for stringent noise control measures and regular health monitoring in industrial settings to mitigate the adverse health effects associated with noise pollution. This research contributes to the body of knowledge on occupational health, emphasizing the importance of creating a safer work environment to enhance workers' wellbeing.

Mathematical modeling and parameter optimization of a stacked piezoelectric energy harvester based on water pressure pulsation

A stacked piezoelectric energy harvester is designed to capture the pressure pulsation in water hydraulic system, and a mathematical model is established to study the energy harvesting performance. The model considers two types of pulsation pressure: standard and double sinusoidal pressure as inputs. The effect of pressure amplitude on energy harvesting performance is studied at different resistances, as well as its parameter optimization. The results show that the theoretical voltage and average power using double sinusoidal pressure as the pressure input are consistent with experimental results, particularly for high pressure pulsation rate. Additionally, the voltage increases with increasing pressure amplitude, and the harmonic frequency amplitude enhances nonlinearity. At lower resistance, the harmonic frequency amplitude has a more significant influence on energy harvesting performance than the fundamental frequency amplitude, but they have similar effects at higher resistance. Furthermore, the optimal resistance to obtain maximum average power initially increases and subsequently stabilizes as the fundamental frequency amplitude increases, but an increase in harmonic frequency amplitude results in decreased optimal resistance. This work provides ideas for the design, modeling and optimization of stacked piezoelectric energy harvester for pressure pulsation in hydraulic system.

Simulation of lighting characteristics of pulse discharge in cesium vapor

Mathematical modeling of characteristics of intense light source on the basis of high pressure pulse discharge in cesium vapor is performed. The investigated discharge is realized in a long ceramic tube from Al2O3 with an internal diameter of 5 mm. The amount of cesium in the discharge is determined by the value of the saturation pressure at the cold end of the tube. A current pulse with amplitude of 40 A to 250 A is periodically passed through the discharge plasma, with a frequency of 400- 1700 Hz. In the work, a mathematical model based on the equations of radiation gas dynamics is used to simulate discharge. When calculating heat exchange by radiation in plasma and light characteristics of discharge, direct integration of the radiation transfer equation is performed. The model takes into account two mechanisms for heating the walls of the gas discharge tube. Firstly, it is the molecular thermal conductivity of the near wall plasma and secondly, it is the absorption of discharge plasma radiation by walls. As a result of the simulation, the dependencies of plasma pressure and temperature, luminous flux and luminous efficacy of the discharge on the temperature of the cold tube end were investigated for different values of amplitudes of current pulses. It is shown that at all current amplitudes there is a pronounced maximum of luminous efficacy. In all studied modes of discharge combustion color rendering index exceeds Ra &gt; 95. It is shown in particular that if the power embedded per unit of discharge length increases to 400 W/cm, the luminous flux reaches 36000 lm/cm.

Design and Fabrication of 1-D CMUT Arrays for Dual-Mode Dual-Frequency Acoustic Angiography Applications.

When microbubble contrast agents are excited at low frequencies (less than 5 MHz), they resonate and produce higher-order harmonics due to their nonlinear behavior. We propose a novel scheme with a capacitive micromachined ultrasonic transducer (CMUT) array to receive high-frequency microbubble harmonics in collapse mode and to transmit a low-frequency high-pressure pulse by releasing the CMUT plate from collapse and pull it back to collapse again in the same transmit-receive cycle. By patterning and etching the substrate to create glass spacers in the device cavity we can reliably operate the CMUT in collapse mode and receive high-frequency signals. Previously, we demonstrated a single-element CMUT with spacers operating in the described fashion. In this article, we present the design and fabrication of a dual-mode, dual-frequency 1-D CMUT array with 256 elements. We present two different insulating glass spacer designs in rectangular cells for the collapse mode. For the device with torus-shaped spacers, the 3 dB receive bandwidth is from 8 to 17 MHz, and the transmitted maximum peak-to-peak pressure from 32 elements at 4 mm focal depth was 2.12 MPa with a 1.21 MPa peak negative pressure, which corresponds to a mechanical index (MI) of 0.58 at 4.3 MHz. For the device with line-shaped spacers, the 3-dB receive bandwidth at 150 V dc bias extends from 10.9 to 19.2 MHz. By increasing the bias voltage to 180 V, the 3 dB bandwidth shifts, and extends from 11.7 to 20.4 MHz. The transmitting maximum peak-to-peak pressure with 32 elements at 4 mm was 2.06 MPa with a peak negative pressure of 1.19 MPa, which corresponds to an MI of 0.62 at 3.7 MHz.

Two Types of Plasma Channel Structure in High Pressure Pulse Discharge in Cesium

Two Types of Plasma Channel Structure in High Pressure Pulse Discharge in Cesium

Experimental studies of dynamic compression of cellulose pulp fibers

The ability to control the structure of the wood-pulp fiber cell wall is an attractive means to obtain increased accessibility to the fiber interior, providing routes for functionalization of the fibers that support further processing and novel material concepts, e.g. improved degree of polymerization, nanofiltration as demonstrated in previous studies. It has been proposed that dynamic compression and decompression of the cellulose pulp fibers in the wet state make it possible to modify the cell wall significantly.We hypothesize that hydrostatic pressure exerted on fibers fully submerged in water will increase the accessibility of the fiber wall by penetrating the fiber through weak spots in the cell wall. To pursue this, we have developed an experimental facility that can subject wet cellulose pulp samples to a pressure pulse ∼10 ms long and with a peak pressure of ∼300 MPa. The experiment is thus specifically designed to elucidate the effect of a rapid high-pressure pulse passing through the cellulose sample and enables studies of changes in structural properties over different size ranges. Different characterization techniques, including Scanning electron microscopy, X-ray diffraction, and wide- and small-angle X-ray scattering, have been used to evaluate the material exposed to pulsed pressure. The mechanism of pressure build-up is estimated computationally to complement the results. Key findings from the experiments consider a decrease in crystallinity and changes in the surface morphology of the cellulose sample.

Flux Vector Splitting Method of Weakly Compressible Water Navier-Stokes Equation and Its Application

Water is a weakly compressible fluid medium. Due to its low compressibility, it is usually assumed that water is an incompressible fluid. However, if there are high-pressure pulse waves in water, the compressibility of the water medium needs to be considered. Typical engineering applications include water hammer protection and pulse fracturing, both of which involve the problem of discontinuous pulse waves. Traditional calculation and simulation often use first-order or second-order precision finite difference methods, such as the MacCormark method. However, these methods have serious numerical dissipation or numerical dispersion, which hinders the accurate evaluation of the pulse peak pressure. In view of this, starting from the weakly compressible Navier–Stokes (N-S) equation, this paper establishes the control equations in the form of flux, derives the expressions of eigenvalues, eigenvectors, and flux vectors, and gives a new flux vector splitting (FVS) formula by considering the water equation of state. On this basis, the above flux vector formula is solved using the fifth-order weighted essentially non-oscillatory (WENO) method. Finally, the proposed FVS formula is verified by combining the typical engineering examples of water hammer and pulse fracturing. Compared with the traditional methods, it is proved that the FVS formula proposed in this paper is reliable and robust. As far as we know, the original work in this paper extends the flux vector splitting method commonly used in aerodynamics to hydrodynamics, and the developed model equation and method are expected to play a positive role in the simulation field of water hammer protection, pulse fracturing, and underwater explosion.

Experimental investigation on the combustion characteristics and thermoacoustic instability of liquid spray flame with blended fuel

This study experimentally investigates the combustion characteristics and thermoacoustic instability of two fuels, ethanol and RP-3, at five different blending ratios. The flame images, root temperature of blended fuel flame and pollutant emissions were photographed and tested. The experimental results indicate that high-pressure pulsation amplitude and airflow disturbance can enhance droplets’ evaporation and combustion processes, resulting in a reduction in flame length. Lower evaporation temperature ensures a higher temperature of the flame root while increasing the blend ratio of RP-3 and increasing the global equivalence ratio can increase the temperature level inside the combustion chamber. The root temperature of ethanol flame can reach over 1400 K. Fuel characteristics and burner structure can influence the coupling between pressure pulsation and flame heat release pulsation, leading to differences in the amplitude of combustion instability. The shorter the outlet length of the burner, the wider the stability range of the flame. Moreover, the increase in total burner length results in a shift of the oscillation dominant frequency towards lower frequencies. Emission characteristic curves reveal that high-pressure pulsation amplitude can improve the combustion efficiency of blended RP-3 fuel but are unfavorable for the complete combustion of ethanol. Meanwhile, under the dilution effect of the airflow, the emissions of NOx and CO at the outlet gradually decrease as the airflow increases.

Transcranial pulse stimulation in the treatment of mild neurocognitive disorders.

There are limited effectiveness and potential side effects of existing pharmacological approach in treating mild neurocognitive disorder (NCD). Transcranial pulse stimulation (TPS) applies repetitive single high-pressure ultrashort shockwave pulses to stimulate the brain, which has been shown to effectively improve cognition in major NCD. However, the effectiveness of TPS in mild NCD patients remained unknown. This study aims to assess the effectiveness and tolerability of TPS with neuro-navigation in old-age adults with mild NCD by both clinical and biochemical assessments. An open-label study recruited older adults with mild NCD to receive neuro-navigated TPS intervention for two weeks with three sessions per week. Assessments included detailed cognitive assessments, APOE genotype, and brain-derived neurotrophic factor (BDNF). Nineteen participants (12 females and 7 males) completed the whole TPS interventions with no serious adverse effects reported. Repeated measures ANOVA showed statistically significant effects of time on HK-MoCA (F (3, 54) = 4.99, P = 0.004), 30-sec interval of Verbal Fluency Test (F (3, 54) = 2.94, P = 0.041), Stroop interference (F (3, 54) = 3.46, P = 0.023), and Chinese IADL (F (3, 54) = 2.78, P = 0.050) after receiving the intervention. Bonferroni post hoc comparisons on HK-MoCA showed a significant improvement after intervention. There was no significant change in serum BDNF level. TPS has brought significant improvement in cognition of elderly with mild NCD. It has a great potential to delay the deterioration of cognition in older adults. The long-term effect of TPS in cognition would benefit from further large-scale, randomized, sham-controlled trials.

High-pressure pulses for Aspergillus niger spore inactivation in a model pharmaceutical lipid emulsion

High hydrostatic pressure (HHP) is a non-thermal process widely used in the food industry to reduce microbial populations. However, rarely its effect has been assessed in products with high oil content. This study evaluated the efficacy of HHP (200, 250, and 300 MPa) at different temperatures (25, 35, and 45 °C) by cycles (1, 2, or 3) of 10 min in the inactivation of Aspergillus niger spores in a lipid emulsion. After treatments at 300 MPa for 1 cycle at 35 or 45 °C, no surviving spores were recovered. All treatments were modeled by the linear and Weibull models. The presence of shoulders and tails in the treatments at 300 MPa at 35 or 45 °C resulted in sigmoidal curves which cannot be described by the linear model, hence the Weibull + Tail, Shoulder + Log-lin + Tail, and double Weibull models were evaluated to elucidate the inactivation kinetics. The tailing formation could be related to the presence of resistance subpopulations. The double Weibull model showed better goodness of fit (RMSE <0.2) to describe the inactivation kinetics of the treatments with the higher spore reductions. HHP at 200–300 MPa and 25 °C did not reduce the Aspergillus niger spores. The combined HHP and mild temperatures (35–45 °C) favored fungal spore inactivation. Spore inactivation in lipid emulsions by HHP did not follow a linear inactivation. HHP at mild temperatures is an alternative to the thermal process in lipid emulsions.

Mechanism of Microbubbles and Cavitation Effect on Bubble Breakage in a Venturi Bubble Generator

Venturi bubble generators have been extensively studied because of having a simple structure and high foaming efficiency, while producing a uniform bubble size. The effect of a noncondensable gas on hydraulic cavitation was considered to improve the Zwart-Gerber-Belamri cavitation model. This improved model and a population balance model were used to study the effect of cavitation on bubble fragmentation. The CFD-PBM results were compared with experimental results, and the accuracy of the improved calculation method was verified in terms of the distributions for the cavitation cavity, gas phase, and bubble size. The calculation results showed that increasing the noncondensable gas content over a certain range promoted the development of hydraulic cavitation, and the cavitation intensity could be indirectly controlled by adjusting the noncondensable gas content. With increasing cavitation intensity, the average bubble size decreased, and the bubble size distribution became narrower. Therefore, a high-pressure pulse generated by cavitation could effectively break bubbles. The development process of microbubbles was studied. The main controlling factors for bubble formation were determined to be the turbulent shear force of the fluid and the collapse impact force of the cavitation group, which provides a theoretical basis for optimizing the design of bubble generators.