Mean Flow Rate Research Articles

Associations between long-term ozone exposure and small airways function in Chinese young adults: a longitudinal cohort study

BackgroundIncreasing evidence is appearing that ozone has adverse effects on health. However, the association between long-term ozone exposure and lung function is still inconclusive.ObjectivesTo investigate the associations between long-term exposure to ozone and lung function in Chinese young adults.MethodsWe conducted a prospective cohort study among 1594 college students with a mean age of 19.2 years at baseline in Shandong, China from September 2020 to September 2021. Lung function indicators were measured in September 2020 and September 2021, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory flow at the 25th, 50th, and 75th percentile of the FVC (FEF25, FEF50, and FEF75) and mean flow rate between 25% and 75% of the FVC (FEF25-75) were measured. Daily 10 km×10 km ozone concentrations come from a well-validated data-fusion approach. The time-weighted average concentrations in 12 months before the lung function test were defined as the long-term ozone exposure. The associations between long-term ozone exposure and lung function indicators in Chinese young adults were investigated using a linear mixed effects model, followed by stratified analyses regarding sex, BMI and history of respiratory diseases.ResultsEach interquartile range (IQR) (8.9 µg/m3) increase in long-term ozone exposure were associated with a -204.3 (95% confidence interval (CI): -361.6, -47.0) ml/s, -146.3 (95% CI: -264.1, -28.4) ml/s, and − 132.8 (95% CI: -239.2, -26.4) ml/s change in FEF25, FEF50, and FEF25-75, respectively. Stronger adverse associations were found in female participants or those with BMI ≥ 24 kg/m2 and history of respiratory diseases.ConclusionLong-term exposure to ambient ozone is associated with impaired small airway indicators in Chinese young adults. Females, participants with BMI ≥ 24 kg/m2 and a history of respiratory disease have stronger associations.

Effects of accumulated exercise on the stiffness and hemodynamics of the common carotid artery.

Purpose: This research aims to study and compare the effects of moderate-intensity continuous exercise and accumulated exercise with different number of bouts on common carotid arterial stiffness and hemodynamic variables. Methods: Thirty healthy male adults were recruited to complete four trials in a randomized crossover design: no-exercise (CON); continuous exercise (CE, 30-min cycling); accumulated exercise including two or three bouts with 10-min rest intervals (AE15, 2 × 15-min cycling; AE10, 3 × 10-min cycling). The intensity in all the exercise trials was set at 45%-55% heart rate reserve. Blood pressure, right common carotid artery center-line velocity, and arterial inner diameter waveforms were measured at baseline and immediately after exercise (0min), 10 min, and 20 min. Results: 1) The arterial stiffness index and pressure-strain elastic modulus of the CE and AE15 groups increased significantly at 0min, arterial diameters decreased in AE15 and AE10, and all indicators recovered at 10min. 2) The mean blood flow rate and carotid artery center-line velocity increased in all trials at 0min, and only the mean blood flow rate of AE10 did not recover at 10min. 3) At 0min, the blood pressure in all trials was found to be increased, and the wall shear stress and oscillatory shear index of AE10 were different from those in CE and AE15. At 20min, the blood pressure of AE10 significantly decreased, and the dynamic resistance, pulsatility index, and peripheral resistance of CE partially recovered. Conclusion: There is no significant difference in the acute effects of continuous exercise and accumulated exercise on the arterial stiffness and diameter of the carotid artery. Compared with continuous exercise, accumulated exercise with an increased number of bouts is more effective in increasing cerebral blood supply and blood pressure regulation, and its oscillatory shear index recovers faster. However, the improvement of blood flow resistance in continuous exercise was better than that in accumulated exercise.

Phase-contrast magnetic resonance imaging of intracranial and extracranial blood flow in carotid near-occlusion

PurposeCompare extracranial internal carotid artery flow rates and intracranial collateral use between conventional ≥ 50% carotid stenosis and carotid near-occlusion, and between symptomatic and asymptomatic carotid near-occlusion.MethodsWe included patients with ≥ 50% carotid stenosis. Degree of stenosis was diagnosed on CTA. Mean blood flow rates were assessed with four-dimensional phase-contrast MRI.ResultsWe included 110 patients of which 83% were symptomatic, and 38% had near-occlusion. Near-occlusions had lower mean internal carotid artery flow (70 ml/min) than conventional ≥ 50% stenoses (203 ml/min, P < .001). Definite use of ≥ 1 collateral was found in 83% (35/42) of near-occlusions and 10% (7/68) of conventional stenoses (P < .001). However, there were no differences in total cerebral blood flow (514 ml/min vs. 519 ml/min, P = .78) or ipsilateral hemispheric blood flow (234 vs. 227 ml/min, P = .52), between near-occlusions and conventional ≥ 50% stenoses, based on phase-contrast MRI flow rates. There were no differences in total cerebral or hemispheric blood flow, or collateral use, between symptomatic and asymptomatic near-occlusions.ConclusionNear-occlusions have lower internal carotid artery flow rates and more collateral use, but similar total cerebral blood flow and hemispheric blood flow, compared to conventional ≥ 50% carotid stenosis.

Mathematical modeling of blood flow in an annulus porous region between two coaxial deformable tubes: An advancement to peristaltic endoscope

In the present work, the electromagnetohydrodynamic peristaltic flow of blood through an annulus region between two concentric circular tubes has been investigated for the advancement of a peristaltic endoscope. In this model, the viscous and incompressible blood is assumed as non-Newtonian Jeffery fluid, and tubes are inclined at an angle β with the horizontal. The governing equations for the considered problem are simplified under the assumption of a low Reynolds number and long wavelength approximations. An analytical expression for various flow variables such as axial velocity, radial velocity, time mean flow rate, volumetric flow rate, frictional force at the surface of the inner tube, and mechanical efficiency is obtained. In this work, we discussed the impact of various flow parameters like the Hartmann number M, electric field strength parameter H, Jeffery fluid parameter λ1, radius ratio n, occlusion ϕ=ba, angle of inclination β, and Darcy number Da on the above flow variables. The streamlines are also made to discuss the trapping phenomena of a fluid bolus inside the tubes. The comparison of pressure rise for the various endoscopes and the validation of the present result with the previously established results are discussed.

The anthropometric determinants of peak expiratory flow rate among children in Dar Es Salaam, Tanzania

BackgroundPeak expiratory flow rate (PEFR) is an important tool for assessing lung function, which can be affected by environmental and physical factors such as altitude, nutrition, genetics, age, height, and weight. Conducting a study to assess the correlation between peak expiratory flow rate and anthropometric measurements in Tanzanian schoolchildren is crucial to derive a population-specific prediction formula and further simplify respiratory health assessment.MethodsThis cross-sectional study was conducted in a single center private primary and secondary school in Dar es Salaam, Tanzania using data from an asthma screening camp. Variables of interest were height, weight, Body Mass Index (BMI) and PEFR. Independent t-test was performed to identify any differences in mean flow rate values between different ethnicities and genders. Correlation coefficients (r) were used to observe the relationship between PEFR and anthropometric measurements. A prediction equation by gender was generated using linear regression analysis. Statistical significance was set at the 5% level. All statistical data was analyzed using SPSS version 25.0.ResultsThe study involved 260 participants with a mean age of 9.5 years. Males were 51.2% and 65% of participants were of Asian ethnicity. PEFR was not observed to differ across the different ethnic groups and genders. Height was found to have the strongest correlation coefficient of 0.745, while BMI had the weakest correlation coefficient of 0.366. The strongest correlation was found with height for females (r = 0.787), while the weakest was with body mass index for boys (r = 0.203). The derived prediction equation for males was PEFR = 279.169 (Height of Student in meters) —134.12, while the predictive equation for females was PEFR = 318.32 (Height of Student in meters) —195.69.ConclusionThis study found a strong correlation between PEFR and anthropometric characteristics in school children from Dar es Salaam, Tanzania. A prediction equation by gender for PEFR was developed based on anthropometric characteristics. This equation may be applied in population-based studies or situations where peak flow meters are not readily available. Further research is needed to explore how well this prediction formula performs in other Tanzanian settings and to determine other factors that may affect lung function in this population.

Nanoleakage of apical sealing using a calcium silicate-based sealer according to canal drying methods.

This study investigated the nanoleakage of root canal obturations using calcium silicate-based sealer according to different drying methods. Fifty-two extracted mandibular premolars with a single root canal and straight root were selected for this study. After canal preparation with a nickel-titanium rotary file system, the specimens were randomly divided into 4 groups according to canal drying methods (1: complete drying, 2: blot drying/distilled water, 3: blot drying/NaOCl, 4: aspiration only). The root canals were obturated using a single-cone filling technique with a calcium silicate-based sealer. Nanoleakage was evaluated using a nanoflow device after 24 hours, 1 week, and 1 month. Data were collected twice per second at the nanoscale and measured in nanoliters per second. Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05). The mean flow rate measured after 24 hours showed the highest value among the time periods in all groups. However, the difference in the flow rate between 1 week and 1 month was not significant. The mean flow rate of the complete drying group was the highest at all time points. After 1 month, the mean flow rate in the blot drying group and the aspiration group was not significantly different. Within the limitations of this study, the canal drying method had a significant effect on leakage and sealing ability in root canal obturations using a calcium silicate-based sealer. Thus, a proper drying procedure is critical in endodontic treatment.

Electro-rheological flow of seminal fluid (K-L MODEL) induced by movement of cilia in a circular conduit

The current study deals with the flow of seminal fluid through the ductus efferentes owing to electro-osmotic force and motion of cilia. The constitutive equation of semen liquid has been assumed to be described as a K-L (Kuang and Luo) fluid model. The main equations of the ciliary flow of K-L model are solved by considering the supremacy of viscous upshot over inertia influence assuming the state of long wave-length number. The analytic expressions for velocity profile, flow rate and flow impedance are derived. This is the first time to bring out to the lime light that the flow impedance is decreased and the plug core radius is enlarged with the introduction of electric force in the ciliary flow system. The effects of pertinent physiological parameters on the time-mean flow rates of rhesus monkey and human semen are thoroughly investigated. The computational mean flow rate's value over the period of time of the current mathematical model has been well matched with the corresponding experimentation values of the time-mean flow rates of rhesus monkey and humanoid semen in the path of generative and the vas deferens of the path of generative of male. Introduction of electric field into the flow ciliary system and the rheology of semen fluid described as K-L fluid model (for the values of rheological parameters of K-L fluid are considered) reduce the flow resistance, which in turn elevates the flow velocity of seminal fluid, which activates the significant and favorable changes for Oocytes getting fertilized within hours of ovulation by means of reasonable volume of semen transport into the female reproductive tract to partake a quick contact with cervical mucus and enter the cervix.

GİRİŞ HIZ PROFİLİ VE GİRİŞ UZUNLUĞUNUN ABDOMİNAL AORT ANEVRİZMASI HEMODİNAMİĞİ SİMÜLASYONLARINA ETKİSİ

In computational Abdominal Aortic Aneurysm (AAA) hemodynamics studies, along with adjusting the problem geometry, mesh, transport, turbulence and rheology models; setting up boundary conditions (BC) is also a very important step which affect the reliability and accuracy of the hemodynamic assessment. The transient effects of physiological flow are well described by the Womersley profile, though its application might be difficult due to the complex nature of functions involved. Conversely, in literature, studies utilizing Plug or Parabolic profiles as inlet boundary conditions generally requires large entrance lengths to obtain the exact characteristics of the Womersley profile. In the current study, the differences arising between those boundary conditions, Womersley, Parabolic and Plug, with different entrance lengths, L_(ent )=D,3D and 11D, are examined by comparing the results with a Base condition, which is a solution obtained with ensured fully-developed flow before entering the aneurysm sac at two physiological flow conditions with mean Reynolds numbers, 〖Re〗_m=340 and 1160. The results reveal that with increasing mean flow rate, applying the complex Womersley equation might not be necessary. For the inlet flow waveform with 〖Re〗_m=1160, the Parabolic profile can be used instead of the Womersley profile by supplying an entrance length L_(ent )= 3D. On the other hand, the Plug profile requires an entrance length at least L_(ent )= 11D to replicate the Base condition for waveform with 〖Re〗_m=340.

The Effects of Free Breathing on Cerebral Venous Flow: A Real-Time Phase Contrast MRI Study in Healthy Adults.

Quantifying the effects of free breathing on cerebral venous flow is crucial for understanding cerebral circulation mechanisms and clinical applications. Unlike conventional cine phase-contrast MRI sequences (CINE-PC), real-time phase-contrast MRI sequences (RT-PC) can provide a continuous beat-to-beat flow signal that makes it possible to quantify the effect of breathing on cerebral venous flow. In this study, we examined 28 healthy human participants, comprising of 14 males and 14 females. Blood flows in the right/left internal jugular veins in the extracranial plane and the superior sagittal sinus (SSS) and straight sinus in the intercranial plane were quantified using CINE-PC and RT-PC. The first objective of this study was to determine the accuracy of RT-PC in quantifying cerebral venous flow, relative to CINE-PC. The second, and main objective, was to quantify the effect of free breathing on cerebral venous flow, using a time-domain multiparameter analysis method. Our results showed that RT-PC can accurately quantify cerebral venous flow with a 2 × 2 mm2 spatial resolution and 75 ms/image time resolution. The mean flow rate, amplitude, stroke volume, and cardiac period of cerebral veins were significantly higher from the mid-end phase of expiration to the mid-end phase of inspiration. Breathing affected the mean flow rates in the jugular veins more than those in the SSS and straight sinus. Furthermore, the effects of free breathing on the flow rate of the left and right jugular veins were not synchronous. These new findings provide a useful reference for better understanding the mechanisms of cerebral circulation.

Impact of hypertension on mean transvalvular gradients in aortic stenosis Lessons learned from in silico modelling

Abstract Introduction The influence of hypertension on the diagnostic assessment of aortic stenosis (AS) severity is unclear, yet clinically relevant. To clarify the effect of hypertension on transvalvular gradients, requires a better understanding of the impact that blood pressure change has on mean flow rate. Also, the effect of various degrees of AS severity, the valve geometry and intrinsic left ventricular contractile function (elastance) on this interaction, needs to be clarified. Existing clinical research on this topic is limited by not incorporating the full complement of factors that influences the directionality and magnitude of mean transvalvular gradient change for any given change in blood pressure. Purpose To use validated flow dynamics modelling grounded in fundamental physics principles to create a digital platform where various parameters can be manipulated to quantify the effects of bloodpressure change on mean transvalvular gradients in various pathological states. Methods A validated, zero-dimensional electro-hydraulic analogue computer model of the human cardiovascular circulatory system was generated. It was used to assess the impact of blood pressure changes on left ventricular pressure and transvalvular gradients at various flow rates, left ventricular elastances, a range of aortic valve areas and for different aortic valve morphologies. Results Mean transvalvular gradients are flow dependent. The impact of hypertension on mean flow rate (MFR), and hence on mean gradient (MG), is influenced by the aortic valve area as well as the underlying left ventricular elastance (Figure 1). Subsequently, the relationship between MFR and MG could be modelled (Figure 2). Generally, for a given change in systemic arterial pressure, the impact on MG will be the most marked for lower flow rate states such as is expected in more severe degrees of AS and for worse intrinsic left ventricular (LV) contractility. Furthermore, for a constant hemodynamic valve area, the hydraulic valve orifice area was found to be smaller in rheumatic AS compared to degenerative AS. This results in less susceptibility to blood pressure induced changes in mean transvalvular gradient. Similarly, the size of the aortic root was found to be inversely related to the susceptibility to induce a change in mean gradient for a change in blood pressure. Conclusion The interaction between hypertension and mean gradients in AS is complex. The current work places previous recommendations in perspective by quantifying the magnitude of the effect that a change in blood pressure has on mean gradient in various pathophysiological states. By doing so it provides more granularity into this multifaceted interaction compared to previously oversimplified deductions from clinical studies. The findings of this study creates a basic science framework based on first principles that dictates the scope of parameters that should be considered in future clinical research on the topic.Modelling 1Modelling 2

Safety and efficacy of prostatic artery embolization in patients with hematuria due to benign prostate hyperplasia

BackgroundBenign prostate hyperplasia (BPH) commonly affects aging men that can result in hematuria. For patients who are not suitable candidates for surgery, prostatic artery embolization (PAE) has emerged as a minimally invasive alternative. This study aimed to assess the safety and efficacy of PAE specifically for treating hematuria in BPH patients who cannot undergo surgery.MethodsThe study included n = 110 participants. PAE was performed, and outcomes of interest, including resolution of hematuria, improvement in lower urinary tract symptoms (LUTS), prostate volume (PV), and quality of life (QoL), were assessed. Adverse events were also analyzed.ResultsThe study demonstrated a 100% clinical success rate in resolving hematuria at 3 months, with no recurrence observed during the 6-month follow-up. Mean hemoglobin levels increased, indicating successful resolution of bleeding. PAE also led to a significant reduction in LUTS severity, as measured by the International Prostate Symptom Score (IPSS). Improvement in the mean maximum urinary flow rate (Qmax) indicated enhanced urinary flow. Additionally, MRI measurements showed a reduction in prostate volume following PAE. These improvements contributed to enhanced QoL for the patients.ConclusionsProstatic artery embolization (PAE) was found to be a safe and effective treatment option for hematuria in BPH patients not suitable for surgery. PAE demonstrated a high success rate in resolving hematuria and resulted in significant improvements in LUTS, prostate volume, and QoL outcomes. These findings have important implications for clinical decision-making and improving patient care for BPH patients with hematuria. Further research and long-term follow-up studies are necessary to validate these findings and assess the durability of PAE outcomes in this patient population.

Combined Analysis of a Phase III Randomized Trial and Phase II Prospective Trial with Blind Control Matching of Patients Receiving Whole-Lung, Low-Dose Radiation for COVID-19: Full Results and Immunologic Correlates of the RESCUE 1-19 Trial

Whole-lung, low-dose radiation (LD-RT) for COVID-19 requires randomization and biologic correlates to determine causality and mechanism. A phase III trial randomized COVID-19 patients to physician's choice of drug therapy with or without LD-RT. Primary endpoint was intubation-free survival (IFS). The trial was designed with 80% power (two-sided log rank, alpha 0.05) to detect a hazard ratio of 0.3 after 12 intubation events. Estimating a 25% event rate, the planned sample size was 84 patients plus 25 to account for declining intubation rates and screen failures. Due to hospitalization declines and other barriers, the trial closed prematurely. Available randomized data were analyzed by intention-to-treat and combined with phase II results and immunologic correlates, using one-sided significance and an alpha of 0.1 to inform future trial design. From Jun 2020-Jun 2022, 14 patients were randomized on a phase III trial. From Apr 2020-Dec 2020, 42 patients were enrolled on a phase II trial and blindly matched to 40 controls from contemporaneous trials. 96 total patients and 193 blood samples were available for analysis. Mean hospital duration with LD-RT was 12.9 vs 15.4 days in controls (p = 0.12). Oxygen flow rate >15 L/min (26% vs 38%, p = .27), high-flow oxygen >30 L/min (24% vs 38%, p = 0.18), non-invasive positive-pressure >60 L/min (9% vs 27%, p = 0.03), and mechanical ventilation (9% vs 24%, p = 0.05) reduced with LD-RT. Mean supplemented oxygen volume was 171,759 vs 547,626 liters in controls, with daily means of 10 vs 23 L/min (p = 0.03). Radiographs worsened in 43% vs 71% of controls (p = 0.03). Arterial blood gas mean P/F ratios improved 22% after LD-RT vs declined 8% in controls (p = 0.12). Mean days febrile were 1.8 vs 2.9 in controls (p = 0.10). Rate of myocardial injury was 47% vs 40% in controls (p = 0.77). Flow cytometry revealed 4-fold and 30-fold larger expansions, respectively, in CD8- and CD4-positive CD3+PD1+Ki67-high proliferating cytotoxic T-cells (300% vs 75% expansion, p = 0.07) and helper T-cells (200% expansion vs 6% contraction, p = 0.03) at day 7. In the randomized cohort, mean oxygen volume fell 75% with LD-RT to 78,336 vs 316,786 liters in controls (p = 0.13), mean flow rates were 5.1 vs 18.4 L/min (p = 0.13), radiographs worsened in 50% vs 100% (p = .17), P/F ratios improved 31% vs declined 68% in controls (p = 0.03), hospital duration was 8.9 vs 11.5 days (p = 0.22), and zero LD-RT patients vs one control intubated. Combined analysis of a phase II/III randomized trial suggests that LD-RT prevents ventilation, reduces supplemental oxygen need, improves clinical course, and enhances immune response. LD-RT may have both immediate direct effects and delayed enhanced immunity in COVID-19. Larger multi-institutional trials are justified.

Acute upper and lower limb hemodynamic responses during single sessions of low- versus high-intensity inspiratory muscle strength training.

Inspiratory muscle strength training (IMST) has shown potential to improve both respiratory and cardiovascular function in health and disease. Less is known about acute hemodynamic responses to a single IMST session, therefore we assessed upper and lower limb blood flow via Doppler ultrasound in the brachial and popliteal arteries, respectively. Mean, anterograde, and retrograde blood flow (BF) and shear rate (SR) were assessed relative to baseline during low-intensity (15% maximal inspiratory pressure - PImax) and high-intensity (75% PImax) IMST. During low-intensity IMST, popliteal BF and SR were reduced by ∼10%, and brachial BF and SR were reduced by ∼40%. During high-intensity IMST, popliteal BF and SR were reduced by ∼20%, and brachial BF and SR were reduced by ∼35%. BF and SR responses were not statistically different between low-intensity and high-intensity training for either blood vessel (P > 0.05). In addition, anterograde BF and SR were significantly decreased in the brachial artery for both low-intensity and high-intensity training (P < 0.05), but not the popliteal artery (P > 0.05). Finally, during IMST retrograde BF and SR were significantly increased in both the upper and lower limbs during low-intensity and high-intensity training (P < 0.05). These data provide novel insight into the acute BF and SR responses to a single bout of IMST and may enhance our understanding of the mechanism(s) by which IMST imparts its beneficial chronic effects on cardiovascular function.NEW & NOTEWORTHY Herein, we demonstrate for the first time that upper and lower limb blood flow and shear rate patterns are altered during a single bout of IMST, at low- and high-intensity training. Specifically, anterograde blood flow and shear rate are significantly reduced in the brachial artery, whereas retrograde blood flow is significantly elevated in both the brachial and popliteal arteries. These findings provide insight into the vascular impact of IMST, which may inform future mechanistic studies.

CFD simulation of an axial discharge rotor-stator mixer: LES versus RANS predictions

The large eddy simulation (LES) technique is used to model the turbulent flow of water in a two-stage, axial discharge, in-line rotor-stator mixer. The WALE sub-grid scale model is employed, and the resulting filtered velocity field is ensemble averaged to predict the mean velocity, turbulent kinetic energy, energy dissipation rate, and energy production rate. The results of these 3-D sliding mesh simulations are compared to analogous RANS predictions on similar meshes using the realizable k-ε turbulence model. Stator slot flow rate and rotor torque/power draw are also monitored. RANS and LES predict similar mean velocity profiles, flow rate and rotor torque. LES predicts higher turbulent kinetic energy, but lower dissipation rate compared to RANS. Results from a coarse and refined computational mesh are compared to discuss the significance of resolving smaller scales for LES. The effect of operating conditions on throughput, power draw, and other quantities of practical utility are also discussed. It was found that prediction of macroscopic quantities such as flow rate and power draw can be done efficiently using either RANS or LES on a relatively course mesh while capturing turbulence quantities requires a well refined LES simulation.

Transport and Attenuation of an Artificial Sweetener and Six Pharmaceutical Compounds in a Sequenced Wetland-Steel Slag Wastewater Treatment System

The occurrence of pharmaceutically active compounds (PhACs), nutrients, and an artificial sweetener acesulfame in wastewater, and subsequent removal in an engineered system comprising aerobic wetland, anaerobic wetland, and steel slag cells, were investigated. The PhACs evaluated in this study covered a range of octanol–water partition coefficients (log Kow = 0.07–2.45) and acid dissociation constants (pKa = 1.7–13.9) and included carbamazepine, caffeine, sulfamethoxazole, ibuprofen, and naproxen. The mean flow rate in the system was 0.89 m3 day−1 (0.02 to 4.27 m3 day−1), representing a hydraulic retention time of 5 days. The removal efficiencies of PO4-P, NH3-N, and cBOD5 in the treatment system were &gt;99, 82, and 98%. The removal efficiencies for the PhACs and acesulfame were classified into four groups, including those that were (a) efficiently removed (caffeine by &gt;75%); (b) moderately removed (ibuprofen by 50–75%); (c) poorly removed (sulfamethoxazole and naproxen by 25–50%); and (d) recalcitrant (carbamazepine and acesulfame by &lt;25%). Variability in concentrations and treatment efficiencies was observed in different sampling events, which may be due to variations in input concentrations or changes in the flow rate. The addition of a steel slag cell increased the overall removal efficiency of the studied compounds, except for carbamazepine.

Synchronous optical intensity and phase measurements to characterize Rayleigh-Bénard convection.

Propagation of a laser beam through the Rayleigh-Bénard (RB) convection is experimentally investigated using synchronous optical wavefront and intensity measurements. Experimental results characterize the turbulence strength and length scales, which are used to inform numerical wave optic simulations employing phase screens. Experimentally found parameters are the refractive index structure constant, mean flow rate, kinetic and thermal dissipation rates, Kolmogorov microscale, outer scale, and shape of the refractive index power spectrum using known models. Synchronization of the wavefront and intensity measurements provide statistics of each metric at the same instance in time, allowing for two methods of comparison with numerical simulations. Numerical simulations prove to be within agreement of experimental and published results. Synchronized measurements provided more insight to develop reliable propagation models. It is determined that the RB test bed is applicable for simulating realistic undersea environments.

Effectiveness of vocal fold medialization surgery on the swallowing function of patients with unilateral vocal fold paralysis.

Vocal fold medialization surgery is generally considered a phonosurgical procedure for improvement of vocal function in patients with glottic insufficiency. However, the literature describing this procedure for the management of dysphagia is limited. This study aims to assess the effects of medialization surgery on swallowing function in patients with unilateral vocal fold paralysis (UVFP). We enrolled 32 patients with UVFP undergoing vocal fold medialization surgery (medialization laryngoplasty combined with arytenoid adduction [ML + AA], 12 cases; injection laryngoplasty [IL], 20 cases). We assessed the aerodynamic vocal function including maximum phonation time and mean flow rate to evaluate glottal closure status. The Hyodo score determined by flexible endoscopic evaluation and Functional Oral Intake Scale (FOIS) were evaluated pre- and postoperatively. Almost 60% of patients with UVFP had dysphagia, and one-third were at high risk for aspiration. Aerodynamic parameters effectively improved after IL and ML + AA. With regard to swallowing, both the FOIS and total Hyodo score were significantly improved postoperatively. We found a particularly significant improvement in pharyngeal clearance. However, patients with high vagal nerve paralysis and postoperative insufficient glottal closure showed poor swallowing benefits after the interventions. In patients with recurrent laryngeal nerve palsy, there were no significant differences in postoperative swallowing function between the ML + AA and IL groups. Vocal fold medialization surgery was effective in improving swallowing function in most cases with UVFP, except for those with high vagal paralysis and insufficient postoperative glottal closure. Both IL and ML + AA showed an equivalent effect on swallowing improvement. 3b.

Pressure-Volume Loop Analysis of Voiding Workload: An Application in Trans-Vaginal Mesh-Repaired Pelvic Organ Prolapse Patients.

Although trans-vaginal mesh (TVM) offers a successful anatomical reconstruction and can subjectively relieve symptoms/signs in pelvic organ prolapse (POP) patients, its objective benefits to the voiding function of the bladder have not been well established. In this study, we investigated the therapeutic advantage of TVM on bladder function by focusing on the thermodynamic workload of voiding. The histories of 31 POP patients who underwent TVM repair were retrospectively reviewed. Cystometry and pressure volume analysis (PVA) of the patients performed before and after the operation were analyzed. TVM postoperatively decreased the mean voiding resistance (mRv, p < 0.05, N = 31), reduced the mean and peak voiding pressure (mPv, p < 0.05 and pPv, p < 0.01, both N = 31), and elevated the mean flow rate (mFv, p < 0.05, N = 31) of voiding. While displaying an insignificant effect on the voided volume (Vv, p < 0.05, N = 31), TVM significantly shortened the voiding time (Tv, p < 0.05, N = 31). TVM postoperatively decreased the loop-enclosed area (Apv, p < 0.05, N = 31) in the PVA, indicating that TVM lessened the workload of voiding. Moreover, in 21 patients who displayed postvoiding urine retention before the operation, TVM decreased the residual volume (Vr, p < 0.01, N = 21). Collectively, our results reveal that TVM postoperatively lessened the workload of bladder voiding by diminishing voiding resistance, which reduced the pressure gradient required for driving urine flow.

Oral Health Status and Salivary Properties among Children before and after Tonsillectomy.

Objectives: Enlarged adenoids can lead to obstruction of the nasopharyngeal airway and subsequent oral respiration. Oral breathing can cause dry mouth, dehydration in gingival tissue, and resistance to plaque accumulation. This study aimed to evaluate the impact of tonsillectomy on oral health status, salivary pH and flow rate, and common complications caused by tonsillar hypertrophy in children. Materials and Methods: An analytical before-and-after study was conducted on 60 children aged 5-12 years who required tonsillectomy. We gathered data through a questionnaire and collected unstimulated saliva using the spitting method for five minutes. Salivary pH was measured by a pH meter and its volume was determined with a calibrated test tube. The plaque index, bleeding index and modified gingival index were determined using a disclosing tablet, Williams' probe and observational examination, respectively. All measurements were repeated one month after tonsillectomy. Paired t-test was used for data analysis. Results: We found a significant increase in mean pH and salivary flow rate after tonsillectomy and observed a decrease in oral health indices among the children one month after surgery. Over half of the children who reported complications such as dry mouth, itchy nose and throat, snoring, night sweats, and sleep disturbances experienced complete recovery after tonsillectomy. Conclusion: Based on the results obtained in the present study, children with enlarged adenoids showed significant improvements in salivary pH, salivary flow rate, and oral health indices, one month after tonsillectomy.

The Influence of Presbylarynx Status on Objective Measures of the Aging Voice

The primary objective of this study was to assess objective voice measures in an elderly population representative of those seen in a tertiary laryngology practice, stratified by sex and presbylarynx status, and compare their measures to each other and to a cohort of young adult patients aged 40 years or less. The secondary objectives of this study were to evaluate and compare the strobovideolaryngoscopy findings across all groups and compare the voice complaints and subjective questionnaire results between the presbylarynx and non-presbylarynx groups. Two hundred and eighty-six adult voice patients (147 females/139 males) were included in this study and stratified into one of three groups: (1) young adults aged 40 years or less (n = 122), (2) patients over the age of 60 without presbylarynx (n = 78), and (3) patients over the age of 60 with a diagnosis of presbylarynx (n = 86). The acoustic analysis included fundamental frequency (F0), voice intensity, standard deviation of the fundamental frequency (SDFF), jitter (Jitt), relative average perturbation (RAP), shimmer (Shim), noise-to-harmonic ratio (NHR), and others. The aerodynamic and pulmonary assessment included maximum phonation time (MPT), S/Z ratio, mean flow rate (MFR), forced expiratory volume in 1 second (FEV1), and maximal mid-expiratory flow (FEF25-75). Coexisting vocal fold conditions and pathologies were also characterized and compared. Statistical analysis was performed using SPSS 28.0.0.0 (IBM, Armonk, NY). All tests were performed in two-tailed, and a P value of less than 0.05 was considered statistically significant. Assessment of vocal fold features revealed a significantly higher prevalence of benign vocal fold lesions in the young adult group for males and females compared to both elderly groups but significantly lower prevalence of vocal fold edema only in young adult females compared to the elderly female groups. Among males, young adults differed significantly from both elderly groups with regard to SDFF, Shim, FEV1, and FEF25-75. However, Jitt and RAP only differed significantly between the young adult and presbylarynx groups. Among females, young adults differed significantly from both elderly groups for F0, SDFF, Jitt, RAP, NHR, CPP, MFR, FEV1, and FEF25-75. However, the non-presbylarynx group had a significantly lower S/Z ratio than the young adult and presbylarynx groups. A comparison of voice complaints between elderly groups revealed breathiness to be significantly more common in the presbylarynx group compared to the non-presbylarynx group, but no other significant differences were found in voice complaints or questionnaire scores. When interpreting objective voice measures, it is critical to consider differences in vocal fold features alongside age-related changes. In addition, sex-related differences in anatomy and the aging process may explain discrepancies in significant findings between young adults and elderly patients stratified by presbylarynx status. However, presbylarynx status alone appears insufficient to generate significant differences in most objective voice measures among the elderly. Yet, presbylarynx status may be sufficient to generate differences in perceptual voice symptoms.