Factors influencing residual air saturation during consecutive imbibition processes in an air-water two-phase fine sandy medium - A laboratory-scale experimental study.

The residual air saturation plays a crucial role in modeling hydrological processes of groundwater and the migration and distribution of contaminants in subsurface environments. However, the influence of factors such as media properties, displacement history, and hydrodynamic conditions on the residual air saturation is not consistent across different displacement scenarios. We conducted consecutive drainage-imbibition cycles in sand-packed columns under hydraulic conditions resembling natural subsurface environments, to investigate the impact of wetting flow rate, initial fluid state, and number of imbibition rounds (NIR) on residual air saturation. The results indicate that residual air saturation changes throughout the imbibition process, with variations separated into three distinct stages, namely, unstable residual air saturation (Sgr-u), momentary residual air saturation (Sgr-m), and stable residual air saturation (Sgr). The results also suggest that the transition from Sgr-u to Sgr is driven by changes in hydraulic pressure and gradient; the calculated values followed the following trend: Sgr > Sgr-u > Sgr-m. An increase in capillary number, which ranged from 1.46 × 10-7 to 3.07 × 10-6, increased Sgr-u and Sgr-m in some columns. The increase in Sgr ranged from 0.034 to 0.117 across all the experimental columns; this consistent increase can be explained by water film expansion at the primary wetting front along with a strengthening of the hydraulic gradient during water injection. Both the pre-covered water film on the sand grain surface and a pore-to-throat aspect ratio of up to 4.42 were identified as important factors for the increased residual air saturation observed during the imbibition process. Initial air saturation (Sai) positively influenced all three types of residual air saturation, while initial capillary pressure (Pci) exhibited a more pronounced inhibitory effect on residual air saturation, as it can partly characterized the initial connectivity of the air phase generated under different drying flow rates. Under identical wetting flow rate conditions, Sgr was higher during the second imbibition than during the first imbibition due to variations in initial fluid state, involving both fluid distribution and the concentration of dissolved air in the pore water. In contrast, NIR did not have an obvious effect on the three types of residual air saturation. This work aims to provide empirical evidences and offer further insights into the capture of non-wetting phases in groundwater environments, as well as to put forward some potential suggestion for future investigations on the retention and migration of contaminants that involves multiphase interface interactions in subsurface environments.

Cardiopulmonary Bypass Blood Flow Rates and Major Adverse Kidney Events in Cardiac Surgery: A Propensity Score-adjusted Before-After Study.

OBJECTIVES: Cardiac surgery associated-acute kidney injury is a common and serious postoperative complication of cardiac surgery, which is associated with increased postoperative morbidity and mortality. This study aimed to explore the association between cardiopulmonary bypass (CPB) blood flow rate (BFR), and major adverse kidney events (MAKEs) at day 30. DESIGN: Retrospective single-center before-after observational study. Patients were divided in 2 groups according to CPB flow rates: a first group with an institutional protocol targeting a CPB-BFR of >2.2 L/min/m² (low CPB-BFR group), and a second group with a modified institutional protocol targeting a CPB-BFR of >2.4 L/min/m² (high CPB-BFR group). The primary outcome was MAKE at 30 days, defined as the composite of death, renal replacement therapy or persistent renal dysfunction. SETTING: The data were collected from clinical routines in university hospital. PARTICIPANTS: Adult patients who underwent elective and urgent cardiac surgery without severe chronic renal failure, for whom CPB duration was ≥90 minutes. INTERVENTIONS: We included 533 patients (low CPB-BFR group, n = 270; high CPB-BFR group, n = 263). MEASUREMENTS AND MAIN RESULTS: A significant decrease in MAKE at 30 days was observed in the high CPB-BFR group (3% v 8%; odds ratio [OR], 0.779; 95% confidence interval [CI], 0.661-0.919; p < 0.001) mainly mediated by a lower 30-day mortality in the high CPB-BFR group (1% v 5%; OR, 0.697; 95% CI, 0.595-0.817; p = 0.001), as was renal replacement therapy (1% v 4%; OR, 0.739; 95% CI, 0.604-0.904; p = 0.016). CONCLUSIONS: In patients undergoing cardiac surgery, increased CPB-BFR was associated with a decrease in MAKE at 30 days including mortality and renal replacement therapy.

Validating respiratory sarcopenia diagnostic criteria by mortality based on a position paper by four professional organizations: Insights from the Otassha study.

AIM: The Japanese Society for Respiratory Care and Rehabilitation, Japanese Association on Sarcopenia and Frailty, Japanese Society of Respiratory Physical Therapy, and Japanese Association of Rehabilitation Nutrition proposed the definition and diagnosis of respiratory sarcopenia using low respiratory muscle strength and appendicular skeletal muscle mass (ASM; ASM/height2) instead of respiratory muscle mass; however, these parameters have not been validated. This study aimed to confirm the validity of the respiratory sarcopenia definition proposed by these four professional organizations. METHODS: Participants of our cohort study in 2015 of 468 community-dwelling older people who were evaluated for sarcopenia and underwent spirometry were included in this analysis. We determined two respiratory sarcopenia models based on low skeletal muscle mass and respiratory muscle strength. Low skeletal muscle mass was defined by low ASM/height2, and low respiratory muscle strength was defined by peak expiratory flow rate (PEFR) or percentage of predicted PEFR (%PEFR). Survival status was assessed 5 years after baseline assessment (in 2020). To evaluate the validity of the cut-off values for PEFR and %PEFR, we determined different respiratory sarcopenia models by sequentially varying the cut-off values for each parameter, including ASM/height2, from high to low. We subsequently calculated the hazard ratio (HR) for mortality for each respiratory sarcopenia model using the Cox proportional hazards model. Additionally, we plotted the HR for each combination of cut-off values for ASM/height2 and PEFR or %PEFR on a three-dimensional chart to observe the relationship between the different cut-off values and HR. RESULTS: A total of 31 people died during the 5-year observation period. With ASM/height2 cut-off values of approximately 7.0 kg/m2 for men and 5.7 kg/m2 for women and %PEFR cut-off values of 66-75%, respiratory sarcopenia was associated with mortality risk (HR, 2.36-3.27, point estimation range). CONCLUSIONS: The definition of respiratory sarcopenia by the four professional organizations is related to future health outcomes, and this definition is valid. Geriatr Gerontol Int 2024; ••: ••-••.

Use of a novel configuration of ports for patients needing intermittent long-term apheresis.

PURPOSE: In patients with a need for frequent but intermittent apheresis, vascular access can prove challenging. We describe the migration of the use of a Vortex LP dual lumen port (Angiodynamics, Latham, NY) to one Powerflow and one ClearVUE power injectable port (Becton Dickinson, Franklin Lakes, NJ) in a series of patients undergoing intermittent apheresis. MATERIALS AND METHODS: All patients had a need for long-term intermittent apheresis. Eight had double lumen Vortex port (pre) and were exchanged for one Powerflow port and one conventional subcutaneous venous port with 90° needle entry (post) while 12 did not have any port in place and received the same configuration. IRB approval was granted. We recorded the treatment time, flow rate, and tissue plasminogen activator (tPA) use for five treatment sessions after placement. When available, we compared five treatments with the Vortex port and the new configuration. RESULTS: The mean treatment time is reduced with the new configuration (P = 0.0033). The predicted mean treatment time, adjusting for gender, race, BMI and age and accounting for correlations within a patient is 91.18 min pre and 77.96 min post. The flow rate is higher with the new configuration (P < 0.0001). The predicted mean flow rate in mL/min is 61.59 for the Vortex port and 71.89 for the new configuration. tPA use was eliminated in the population converted from Vortex ports and had a 48% reduction when compared to all other configurations in the study. CONCLUSION: The introduction of a novel device configuration of venous access ports for intermittent apheresis resulted in higher flow rates and less total time for treatment. Use of tPA was greatly reduced. These results suggest that the new configuration could result in less expense for the hospital and better throughput in a busy pheresis practice. Clinical trial registration with ClinicalTrials.gov: NCT04846374.

Comparison of Salivary Flow Rate, pH, Buffering Capacity, and Secretory Immunoglobulin A Levels between Children with Early Childhood Caries and Caries-free Children.

Background and objectives: Early childhood caries (ECC) is the most common chronic disease of childhood in many developing countries, which is associated with local, systemic, psychological, and social consequences. Multiple variables are shown to be associated with an increased risk of ECC. The knowledge regarding the role of saliva in the pathophysiological process of ECC still remains controversial and unexplored. Scanty studies focused on probing the role of salivary flow rate, pH, buffering capacity, and secretory immunoglobulin A (sIgA) in unstimulated whole saliva of children with ECC and children without ECC. Aim: To assess the salivary flow rate, pH, buffering capacity, and sIgA levels in children with ECC and caries-free children and to evaluate their role in caries risk assessment.Materials and Methods: The study was carried out among 64 children aged between 24 and 71 months. Clinical examinations were carried out according to the criteria by the World Health Organization, and carious status was recorded. Subjects were categorized as group I with ECC (dmfs-Decayed, Missing or Filled Surfaces (Deciduous dentition) of ≥5), and group II included children without ECC (dmfs = 0). Unstimulated whole salivary samples were collected in a sterile vial and stored at -70°C by draining. Estimations of salivary flow rate, pH, buffering capacity, and sIgA levels were done. Digital pH meters were used for the estimation of pH and buffering capacity. A human IgA enzyme-linked immunosorbent assay (ELISA) kit was used to estimate sIgA levels. Statistical software IBM Statistical Package for the Social Sciences (SPSS) statistics 20.0 (IBM Corporation, Armonk, New York, United States of America) was used to analyze the data. Results: The mean salivary flow rate decreased in group I children with ECC (0.15 ± 0.05) when compared to group II children without ECC (0.67 ± 0.14), which was statistically significant. In caries active children, no statistically significant correlation was found between salivary flow rate and the dmfs scores [r-value (-0.247)] and p-value (0.147). The mean level of salivary pH is decreased in group I children with ECC (4.65 ± 0.4) when compared to group II children without ECC (7.28 ± 0.18). In the caries active group, the levels of salivary pH decrease as the dmfs scores increase, and this correlation is found to be statistically significant (r-value of 0.547 and p-value of 0.002). The mean level of buffering capacity is decreased for caries-active children (5.45 ± 0.49) when compared to caries-free children (8.94 ± 0.42). In caries active children, as the dmfs scores increase, the salivary buffering capacity decreases, and this correlation is found to be not statistically significant (r-value of -0.334 and p-value of 0.161). The mean levels of sIgA in group I children with ECC were higher (10.61 ± 0.90) than that in group II children without ECC (6.11 ± 1.22). In the caries-active group, the salivary sIgA levels were comparatively higher than in the caries-free children. As the dmfs scores increase, the level of the sIgA increases in caries-active children, and this correlation is noted to be highly statistically significant (r-value of 0.769 and p-value 0.008). Conclusion: Children with ECC showed decreased salivary flow rate, pH, buffering capacity, and increased sIgA levels, while children without ECC showed increased salivary flow rate, pH, buffering capacity, and decreased sIgA levels. The salivary parameters, such as salivary flow rate and buffering capacity, showed no correlation with the dmfs score, while salivary pH and sIgA levels have a positive correlation in caries-active children. How to cite this article: Sivakumar A, Narayanan R. Comparison of Salivary Flow Rate, Ph, Buffering Capacity, and Secretory Immunoglobulin A Levels between Children with Early Childhood Caries and Caries-free Children. Int J Clin Pediatr Dent 2024;17(3):334-340.

[Empirical Study on the Impact of Infusion Media on the Flow Rate of Infusion Pumps].

Objective: To investigate the impact of different infusion media on the flow rate of infusion pumps. Methods: Ten infusion pumps were randomly selected and tested for infusion rates using deionized water, saline solution, glucose solution, and parenteral nutrition solution. The infusion flow rate was set at 30 mL/h, and the testing methodology conformed to the standards for the calibration and quality control of syringe pumps and infusion pumps. Results: For infusion set A, the infusion rate was unaffected by the infusion media, remaining within the acceptable quality control standards. For infusion set B, when infused with deionized water, saline solution, and glucose solution, the infusion errors were within the quality control standards. However, when using parenteral nutrition solution as the infusion medium, the infusion error exceeded the acceptable quality control standards. Conclusion: Both the infusion set and the infusion medium can affect the flow rate of infusion pumps. It is crucial to calibrate the flow rate according to the specific infusion medium to reduce medical risks associated with infusion pumps during clinical use.

Toward Metallized Pellets for Steelmaking by Hydrogen Cooling Reduction: Effect of Gas Flow Rate.

This study proposed a strategy to prepare metalized pellets for direct steelmaking by hydrogen cooling reduction (HCR) of iron ore pellets with a focus on the effect of H2 flow rate on the process. It was demonstrated that increasing H2 flow rate could effectively enhance the reduction performance of iron ore pellets. However, due to the influence of the countercurrent diffusion resistance of gas molecules, too high H2 flow rate no longer promoted the reduction of the pellets when the maximum reduction rate was reached. The reduction swelling index (RSI) of the pellets initially increased and then decreased with increasing H2 flow rate. This change was associated with the decreased content of Fe2SiO4 in the metalized pellets and the changes in porosity and iron particle size. The compressive strength (CS) decreased continuously, showing a sharp decline when the H2 flow rate reached 0.6 L/min. It was attributed to the significant increases in porosity and average pore size of the metalized pellets, with the presence of surface cracks. When the H2 flow rate was 0.8 L/min, the metalized pellets had the optimal performance, namely, reduction degree of 91.45%, metallization degree of 84.07%, total iron content of 80.67 wt%, RSI of 4.66%, and CS of 1265 N/p. The findings demonstrated the importance of controlling the H2 flow rate in the preparation of metallized pellets by HCR.

Enhancing the Quality of Polypropylene Recyclates: Predictive Modelling of the Melt Flow Rate and Shear Viscosity.

The extensive use of polypropylene (PP) in various industries has heightened interest in developing efficient methods for recycling and optimising its mixtures. This study focuses on formulating predictive models for the Melt Flow Rate (MFR) and shear viscosity of PP blends. The investigation involved characterising various grades, including virgin homopolymers, copolymers, and post-consumer recyclates, in accordance with ISO 1133 standards. The research examined both binary and ternary blends, utilising traditional mixing rules and symbolic regression to predict rheological properties. High accuracy was achieved with the Arrhenius and Cragoe models, attaining R2 values over 0.99. Symbolic regression further enhanced these models, offering significant improvements. To mitigate overfitting, empirical noise and variable swapping were introduced, increasing the models' robustness and generalisability. The results demonstrated that the developed models could reliably predict MFR and shear viscosity, providing a valuable tool for improving the quality and consistency of PP mixtures. These advancements support the development of recycling technologies and sustainable practices in the polymer industry by optimising processing and enhancing the use of recycled materials.

The Infusion of Piperacillin/Tazobactam with an Elastomeric Device: A Combined 24-H Stability Study and Drug Solution Flow Rate Analysis.

Bacterial respiratory tract infections (e.g., in patients with cystic fibrosis) may be treated with the intravenous infusion of a piperacillin/tazobactam (P/T) solution through an elastomeric device. In the present work, we combined a 24-h drug stability study with an assessment of the drug solution flow rate during an in vitro simulated infusion. Experiments were performed in triplicate with two excipient-free generic P/T solutions and an excipient-containing proprietary P/T solution in saline (all 50/6.25 mg/mL) released from an elastomeric infusion device at 32 °C. The P/T solutions' stability was assessed by an HPLC-UV assay, pH and osmolality measurements, a visual assessment, and particle counting. Before these analyses, a forced degradation study was performed. To assess the flow rate, a precision scale was used to weigh the solution collected at the infusion line outlet. The stability criteria were <10% degradation and a flow rate within ± 15% of the nominal value over the 24-h infusion period: all three P/T solutions were found to be stable. The actual flow rate was lower than the expected flow rate; this difference was probably due to the drug solution's high viscosity and must be taken into account in clinical use.

Pulmonary Inhalation of Biotherapeutics: A Systematic Approach to Understanding the Effects of Atomisation Gas Flow Rate on Particle Physiochemical Properties and Retained Bioactivity.

The identification of spray-drying processing parameters capable of producing particles suitable for pulmonary inhalation with retained bioactivity underpins the development of inhalable biotherapeutics. Effective delivery of biopharmaceuticals via pulmonary delivery routes such as dry powder inhalation (DPI) requires developing techniques that engineer particles to well-defined target profiles while simultaneously minimising protein denaturation. This study examines the simultaneous effects of atomisation gas flow rate on particle properties and retained bioactivity for the model biopharmaceutical lysozyme. The results show that optimising the interplay between atomisation gas flow rate and excipient concentration enables the production of free-flowing powder with retained bioactivity approaching 100%, moisture content below 4%, and D50 < 4 µm, at yields exceeding 50%. The developed methodologies inform the future design of protein-specific spray-drying parameters for inhalable biotherapeutics.

Optimization of Operational Parameters of Plant Protection UAV.

The operational parameters of plant protection unmanned aerial vehicles (UAVs) significantly impact spraying effectiveness, but the underlying mechanism remains unclear. This paper conducted a full factorial experiment with varying flight speeds, heights, and nozzle flow rates to collect parameter space data. Using the Kriging surrogate model, we characterized this parameter space and subsequently optimized the average deposition rate and coefficient of variation by employing a variable crossover (mutation) probability multi-objective genetic algorithm. In the obtained Pareto front, the average sedimentation rate is no less than 46%, with a maximum of 56.08%, and the CV coefficient is no more than 13.91%, with a minimum of only 8.42%. These optimized parameters enhance both the average deposition rate and spraying uniformity compared to experimental data. By employing these optimized parameters in practical applications, a balance between the maximum average deposition rate and minimum coefficient of variation can be achieved during UAV spraying, thereby reducing pesticide usage, promoting sustainable agriculture, and mitigating instances of missed spraying and re-spraying.

In-use stability of Rituximab and IVIG during intravenous infusion: Impact of peristaltic pump, IV bags, flow rate, and plastic syringes.

This study investigates the impact of intravenous (IV) infusion protocols on the stability of Intravenous Immunoglobulin G (IVIG) and Rituximab, with a particular focus on subvisible particle generation. Infusion set based on peristaltic movement (Medifusion DI-2000 pump) was compared to a gravity-based infusion system (Accu-Drip) at different flow rates. The impacts of different diluents (0.9 % saline and 5.0 % dextrose) and plastic syringes with or without silicone oil (SO) were also investigated. The results from the aforementioned particular case demonstrated that peristaltic pumps generated high levels of subvisible particles (prominently < 25 µm), exacerbated by increasing flow rates, specifically in formulations lacking surfactants. Other factors, such as diluent type and syringe composition, also increased the number of subvisible particles. Strategies that can help overcome these complications include surfactant addition as well as the use of SO-free syringes and a gravity infusion system, which aid in reducing particle formation and preserving antibody monomer during administration. Altogether, these findings highlight the importance of the careful selection of formulations and infusion protocols to minimize particle generation during IV infusion both for patients' safety and treatment efficacy.

Dos and don'ts to optimize transnasal aerosol drug delivery in clinical practice.

INTRODUCTION: Transnasal aerosol drug delivery has become widely accepted for treating acutely ill infants, children, and adults. More recently aerosol administration to wider populations receiving high and low-flow nasal oxygen has become common practice. AREAS COVERED: Skepticism of insufficient aerosol delivery to the lungs has been tempered by multiple in vitro explorations of variables to optimize delivery efficiency. Additionally, clinical studies demonstrated comparable clinical responses to orally inhaled aerosols. This paper provides essential clinical guidance on how to improve transnasal aerosol delivery based on device-, settings-, and drug-related optimization to serve as a resource for educational initiatives and quality enhancement endeavors at healthcare institutions. EXPERT OPINION: Transnasal aerosol delivery is proliferating worldwide, but indiscriminate use of excessive-high flows, poor selection and placement of aerosol devices and circuits can greatly reduce aerosol delivery and efficacy, potentially compromising treatment to acute and critically ill patients. Attention to these details can improve inhaled dose by an order of magnitude, making the difference between effective treatment and the progression to more invasive ventilatory support, with greater inherent risk and cost. These revelations have prompted specific recommendations for optimal delivery, driving advancements in aerosol generators, formulations, and future device designs to administer aerosols and maximize treatment effectiveness.

The Accuracy of PUMA Questionnaire in Combination With Peak Expiratory Flow Rate to Identify At-risk, Undiagnosed COPD Patients.

INTRODUCTION: The English PUMA questionnaire emerges as an effective COPD case-finding tool. We aimed to use the PUMA questionnaire in combination with peak expiratory flow rate (PEFR) to improve case-finding efficacy in Chinese population. METHODS: This cross-sectional, observational study included two stages: translating English to Chinese PUMA (C-PUMA) questionnaire with linguistic validation and psychometric evaluation, followed by clinical validation. Eligible participants (with age ≥40 years, respiratory symptoms, smoking history ≥10 pack-years) were enrolled and subjected to three questionnaires (C-PUMA, COPD assessment test [CAT], and generic health survey [SF-12V2]), PEFR measurement, and confirmatory spirometry. The C-PUMA score and PEFR were incorporated into a PUMA-PEFR prediction model applying binary logistic regression coefficients to estimate the probability of COPD (PCOPD). RESULTS: C-PUMA was finalized through standard forward-backward translation processes and confirmation of good readability, comprehensibility, and reliability. In clinical validation, 240 participants completed the study. 78/240 (32.5%) were diagnosed with COPD. C-PUMA exhibited significant validity (correlated with CAT or physical component scores of SF-12V2, both P<0.05, respectively). PUMA-PEFR model had higher diagnostic accuracy than C-PUMA alone (area under ROC curve, 0.893 vs. 0.749, P<0.05). The best cutoff values of C-PUMA and PUMA-PEFR model (PCOPD) were ≥6 and ≥0.39, accounting for a sensitivity/specificity/numbers needed to screen of 77%/64%/3 and 79%/88%/2, respectively. C-PUMA ≥5 detected more underdiagnosed patients, up to 11.5% (vs. C-PUMA ≥6). CONCLUSION: C-PUMA is well-validated. The PUMA-PEFR model provides more accurate and cost-effective case-finding efficacy than C-PUMA alone in at-risk, undiagnosed COPD patients. These tools can be useful to detect COPD early.

Evaluation of Pulmonary Function in Post-convalescent COVID-19 Adults: A Comparative Insight.

Background and objective COVID-19 is a respiratory disease that is highly contagious and is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms vary from mild to severe, where most of the patients suffer from high fever, severe headaches, dry cough, and exhaustion, while the less common symptoms are diarrhea, loss of taste, sore throat, and loss of smell. Following recovery from COVID-19, some patients displayed a restricted pattern in the function of their lungs. As a result, documenting the effects of COVID-19 after infection is essential since it provides a better understanding of the long-term consequences of COVID-19. Hence, the objective of the present study was to assess pulmonary functions in post-convalescent COVID-19 patients. Methodology A cross-sectional comparative study was conducted among students and staff members of Gulf Medical University for a duration of one year from 2021 to 2022. Through a convenient sampling method, a total of 100 participants were recruited for the present study, in which pulmonary function tests (PFTs) were performed using a spirometer, and O2 levels were measured using a pulse oximeter. Additionally, respiratory rate and pulse rate were monitored. Results The present study highlighted the comparison of PFTs in post-convalescent COVID-19 patients and concluded that smoker and convalescent COVID-19 groups showed non-significant decrease (p>0.05) in forced vital capacity (FVC) prediction, forced expiratory volume in the first second (FEV1) prediction, FEV1/FVC%, forced mid-expiratory flow rate (FEF25-75%) prediction, peak expiratory flow rate (PEFR) prediction, respiratory rate, and pulse rate in comparison to the control group. In comparison to the convalescent COVID-19 group, convalescent COVID-19 smoking patients showed a significant increase in FEV1/FVC% (p=0.04). Additionally, in comparison to the convalescent COVID-19 group, a significant increase in PEFR prediction values was observed with a p-value of 0.045 and in comparison to the smoker group with a p-value of 0.006. Moreover, oxygen saturation (SpO2) levels demonstrated non-significant changes between the groups. Conclusion The study concluded that for FEV1/FVC% and PEFR prediction values among the convalescent COVID-19 smoking patient group, a significant increase was observed in comparison to the convalescent COVID-19 group. This aids healthcare professionals in amending strategies to prevent consequences resulting from post-COVID-19 infection.

Taste Changes and Salivary Flow Rate Disparities in Premenopausal and Postmenopausal Women: Exploring the Zinc Connection.

INTRODUCTION: Menopause triggers hormonal changes that can manifest in oral symptoms like dysgeusia, xerostomia, and burning sensations, substantially impacting daily life, including chewing, swallowing, and taste perception. Menopausal women are particularly susceptible to nutritional fluctuations, including variations in zinc levels, which are believed to be linked to taste perception. Taste alterations can render food unappetizing, leading to malnutrition and diminished quality of life. The study aims to assess taste alterations, salivary flow rate, and zinc levels in premenopausal and postmenopausal women, investigating the correlation between these factors. MATERIALS AND METHODS: This research involved 30 premenopausal and 30 postmenopausal women randomly selected from outpatients at the Department of Oral Medicine and Radiology, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, India. Saliva samples were collected, unstimulated salivary flow rates were measured, taste perception was evaluated using a whole mouth threshold taste test, and serum zinc levels were assessed. RESULTS: The study revealed that a significantly higher percentage of postmenopausal women could not identify sucrose taste at concentrations 1 (76.7%, p = 0.017) and concentrations 2 (56.7%, p = 0.007) compared to premenopausal women (43.3%, 20%, respectively). A statistically significant number of postmenopausal women also couldn't identify the bitter taste at concentration 1 (43.3%, p=0.047) compared to premenopausal women. No significant difference in taste perception of salt and sour was observed between both groups at all tested concentrations. In both groups, mean taste perception rankings were similar, with salt being most perceived, followed by sour bitter, and at least with sucrose. Salivary flow rates and zinc levels did not significantly differ between premenopausal and postmenopausal women. The correlation between zinc levels and taste perception was weak and non-significant, indicating that zinc levels were not significant predictors of taste perception in either group. CONCLUSION: Postmenopausal women exhibited reduced perceptions of sucrose and quinine hydrochloride, potentially impacting eating habits, while taste perception of sodium chloride and citric acid remained relatively consistent. Salivary flow rates and zinc levels were within the normal range for postmenopausal women up to 60 years of age included in the study. The study demonstrated that zinc levels did not significantly influence perception among postmenopausal women, suggesting that taste impairment is a multifactorial phenomenon.

Threshold effects between caffeine intake and urine flow rate: a population-based cross-sectional study.

PURPOSE: The potential benefits of caffeine intake are currently receiving much attention and exploration. Urine flow rate (UFR) is an objective index to comprehensively reflect bladder function. The aim of this study was to investigate the association between caffeine intake and UFR using the National Health and Nutrition Examination Survey (NHANES) database. METHODS: 14,142 participants were enrolled in this study. Weighted multivariate adjusted regression models were used to explore the relationship between caffeine intake and UFR. The dose-response relationships were explored using a restricted cubic spline (RCS) and a threshold effect analysis was conducted based on the inflection points identified by the two-segment linear regression model. In addition, subgroup analysis and sensitivity analysis were applied. RESULTS: The findings suggested that the intake of caffeine was correlated with improved UFR [Model 3: 0.091 (0.057, 0.126), P value < 0.001]. In addition, the RCS supported a nonlinear relationship between them. The analysis of threshold effect further revealed a specific level of caffeine intake (34.51 mg/day) that exhibited a significant enhancement in UFR. Finally, through re-analyzing the data set obtained after multiple imputation (MI), we obtained similar results. CONCLUSION: This study found a nonlinear beneficial relationship between caffeine intake and UFR, and revealed the recommended intake of caffeine. The values varied by gender, race, education, and smoking status.

The impact of dialysate flow rate on haemodialysis adequacy: a systematic review and meta-analysis.

Background: Patients with kidney failure treated with maintenance haemodialysis (HD) require appropriate small molecule clearance. Historically, a component of measuring 'dialysis adequacy' has been quantified using urea kinetic modelling that is dependent on the HD prescription. However, the impact of dialysate flow rate on urea clearance remains poorly described in vivo and its influence on other patient-important outcomes of adequacy is uncertain. Methods: We searched Embase, MEDLINE and the Cochrane Library from inception until April 2022 for randomized controlled trials and observational trials comparing a higher dialysate flow rate (800 ml/min) and lower dialysate flow rate (300 ml/min) with a standard dialysis flow rate (500 ml/min) in adults (age ≥18 years) treated with maintenance HD (>90 consecutive days). We conducted a random effects meta-analysis to estimate the pooled mean difference in dialysis adequacy as measured by Kt/V or urea reduction ratio (URR). Results: A total of 3118 studies were identified. Of those, nine met eligibility criteria and four were included in the meta-analysis. A higher dialysate flow rate (800 ml/min) increased single-pool Kt/V by 0.08 [95% confidence interval (CI) 0.05-0.10, P < .00001] and URR by 3.38 (95% CI 1.97-4.78, P < .00001) compared with a dialysate flow rate of 500 ml/min. Clinically relevant outcomes including symptoms, cognition, physical function and mortality were lacking and studies were generally at a moderate risk of bias due to issues with randomization sequence generation, allocation concealment and blinding. Conclusion: A higher dialysate flow increased urea-based markers of dialysis adequacy. Additional high-quality research is needed to determine the clinical, economic and environmental impacts of higher dialysate flow rates.

Efficacy of Lemon Mouthwash in Improving Dry Mouth Symptoms and Salivary Flow in Hemodialysis Patients.

OBJECTIVES: Gargling mouthwash is a safe and convenient oral care intervention; it rinses the mouth and increases salivary flow rate. The effectiveness of lemon mouthwash in relieving xerostomia and increasing the salivary flow rate among hemodialysis patients has not been studied. Our study sought to analyze the effectiveness of varying concentrations of lemon in mouthwash solutions on xerostomia and salivary flow rate. METHODS: A multi-concentration test was used to assess lemon mouthwash at 20%, 15%, 10%, 5%, and 2.5% concentrations to determine the optimal concentration for relieving dry mouth and increasing salivary flow rate. Generalized estimating equations were used to analyze the differences between various concentrations of lemon mouthwash and baseline values. RESULTS: In total, 44 patients were recruited. The 10% lemon concentration mouthwash was the most effective for increasing salivary flow rate, but the 5% and 2.5% were better accepted by the participants. Our findings can help establish intervention guidelines to relieve xerostomia among hemodialysis patients. CONCLUSION: Our findings can help establish intervention guidelines to relieve xerostomia among hemodialysis patients.

Coronary microvascular dysfunction and left heart filling pressures in patients with type 2 diabetes.

AIMS: Patients with type 2 diabetes (T2D) have a high prevalence of diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF), which in turn leads to an increased risk of hospitalization and death. However, the factors of risk and their relative importance in leading to higher left ventricular filling pressures are still disputed. We sought to clarify the associations of a wide range of invasive and non-invasive risk factors with cardiac filling pressures in high-risk T2D patients. METHODS AND RESULTS: Patients with T2D at high risk of cardiovascular events were prospectively enrolled in this study. Participants were thoroughly phenotyped including right heart catheterization at rest and during exercise, echocardiography, urinary excretion of albumin (UACR), and quantification of their myocardial blood flow rate (MFR) using cardiac 82Rb-PET/CT. Of the 37 patients included in the study, 22 (59%) patients met invasive criteria for HFpEF. Only 2 out of 39 variables emerged as independent factors associated with left ventricular filling pressure as assessed by pulmonary capillary wedge pressure (PCWP) at rest; history of hypertension (coefficient: 2.6 mmHg [0.3; 5.0], P = 0.030) and MFR (P = 0.026). We found a significant inverse association between MFR and PCWP with a coefficient of -2.3 mmHg (-4.3; -0.3) in PCWP per integer change of MFR. The MFR ranged from 1.18 to 3.68 in our study, which corresponds to a difference in PCWP of approximately 6 mmHg between patients with the lowest compared to the highest MFR. During exercise, only 2 variables emerged as borderline independent factors associated with PCWP: myocardial flow reserve (coefficient: -4.4 [-9.6; 0.8], P = 0.091) and beta-blockers use (coefficient: 6.1 [-0.1; 12.4], P = 0.053). CONCLUSIONS: In patients with type 2 diabetes without known HFpEF but risk factors for cardiovascular disease, myocardial blood flow rate was independently associated with PCWP at rest across the range from normal to abnormal left heart filling pressures. A clinically significant difference of 6 mmHg in PWCP was attributable to differences in MFR in patients with the lowest compared with the highest MFR values. This suggests that strategies than attenuate microvascular dysfunction could slow progression of increased left ventricular left heart filling pressures in patients at increased risk.