Flow Algorithm Research Articles (Page 2)

Measuring river surface velocity is crucial for hydrological monitoring. However, traditional methods exhibit significant limitations under extreme weather conditions and emergency scenarios. In this study, we propose OF-PhyNet, an innovative hybrid neural network architecture designed as an image-based velocimetry method to improve the accuracy of river surface velocity estimation. By integrating an optical flow algorithm with a physics-informed neural network, OF-PhyNet achieves deep coupling of motion feature extraction with fluid dynamics constraints. To address the challenges posed by uneven particle distribution and illumination variations in natural rivers, we introduce a feature extraction strategy based on K-means clustering and morphological operations, which enables effective flow field segmentation and reliable identification of particle regions. Experimental validation conducted in the Heihe River Basin, using Stalker Pro II surface velocity radar (SVR) as a reference, demonstrates that OF-PhyNet achieves a mean absolute error of 0.054 m/s and a relative error of 7.22% across 12 cross-sectional measurement points, substantially outperforming PIVLab with 11.65% and the Horn-Schunck algorithm with 25.84% relative error. As a UAV-based image velocimetry approach, OF-PhyNet offers exceptional mobility for rapid flood monitoring and enables robust reconstruction of flow fields in particle-sparse regions, delivering precise non-contact river velocity measurements beyond the reach of traditional methods.

Multiscale anisotropic scaffolds enable a biomimetic electro-mechanical myocardial platform for drug discovery and heart repair.

Accurate estimation of state of charge (SoC) for lithium-ion battery packs is crucial for ensuring system safety and optimizing energy management. Most existing SoC estimation methods are centralized, relying on a central node to unify computation, which tend to lead to a heavy communication burden and poor reliability in the event of node or communication failure. Therefore, this article proposes a SoC estimation method for lithium-ion battery packs based on a distributed consensus algorithm. The method consists of two functional modules, the first part of which employs the Luenberger observer for SoC estimation of each battery cell. The second part utilizes the signed gradient descent flow algorithm to realize the distributed estimation of the SoC of battery cells, and ultimately obtains the SoC of the battery pack. We demonstrate that the proposed method converges in a finite time. Experiments verify the effectiveness and robustness of the proposed method. The results show that, compared with the centralized methods, the proposed approach exhibits superior fault tolerance, maintaining estimation errors within 1% even under communication failures.

Objective: To evaluate the nursing value of mechanical expectoration drainage combined with traditional Chinese medicine acupoint application in children with pediatric bronchial pneumonia. Methods: A total of 62 children with pediatric bronchial pneumonia treated from May 2024 to May 2025 were selected as samples and randomly divided into groups using a random number table. Group A received mechanical expectoration drainage combined with traditional Chinese medicine acupoint application nursing, while Group B received conventional nursing. Lung function, symptom disappearance time, nursing satisfaction, and inflammatory indicators were compared between the two groups. Results: The maximum vital capacity (FVC), forced expiratory volume in one second (FEV), peak expiratory flow (PEF), and maximal mid-expiratory flow (MMEF) in Group A were all higher than those in Group B, with p < 0.05; the symptom disappearance time in Group A was shorter than that in Group B, and nursing satisfaction was higher in Group A than in Group B, with p < 0.05; the procalcitonin (PCT), white blood cell count (WBC), and serum amyloid A (SAA) levels in Group A were lower than those in Group B, with p < 0.05. Conclusion: The application of mechanical expectoration drainage combined with traditional Chinese medicine acupoint application nursing in the care of children with pediatric bronchial pneumonia reduces inflammation levels, shortens symptom disappearance time, and improves lung function.

The presence of fountains in public areas can create a comfortable atmosphere for everyone. Green spaces can provide ecological and aesthetic benefits, so fountains that combine ecological and aesthetic functions were essential. Based on this, research was conducted to test the performance of the water flow control system and nozzle movement control in a fountain integrated with automatic plant irrigation. Water flow testing was conducted by setting the dimmer at angles of 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, and 65°. Nozzle movement testing was carried out by giving servo motor movement commands at angles of 50° – 130° and gradually adding an angle of 4° for each test. The data collected in the study were water flow and nozzle movement accuracy. Based on the test results, the minimum flow rate recorded was 0.141 l/s at an angle of 20°, the maximum flow rate reached 0.775 l/s at an angle of 65°, while the average flow rate from the tests was 0.490 l/s. The nozzle movement system showed an average accuracy of 98.84%, indicating that the system performs very well. The test results showed that the water discharge control and nozzle movement systems were able to produce controlled water jets, both in terms of flow rate and direction.

The relevance of this study is driven by the need to address a key scientific and applied problem—understanding the dynamics of maximum runoff formation during spring floods in the context of increasing climate variability. In Vinnytsia Region, the transformation of snow cover, altered flood genesis, and rising temperatures significantly influence maximum runoff values and associated flood risks. Therefore, identifying limiting characteristics of slope inflow under current climatic conditions is essential for sustainable water management and hydraulic engineering. Numerous studies have highlighted climate-induced changes in the hydrological regime of Ukrainian rivers; however, the dynamics of slope inflow formation and the spatial variability of maximum runoff modules for the rivers of the Vinnytsia Region remain insufficiently studied. Existing gaps relate primarily to the lack of quantitative assessments of extreme slope inflow modules and their dependence on watershed characteristics under contemporary climate trends. This article aims to determine the limiting values of maximum slope inflow modules and to assess the current hydrological conditions of spring flood formation using long-term observational data from hydrological stations across Vinnytsia Region. The study employs classical statistical techniques (method of moments, maximum likelihood estimation, and Kritzky–Menkel gamma distribution), as well as numerical methods for determining slope inflow duration and unevenness, and an operator-based runoff formation model grounded in channel isochrone theory. Presentation of the main research material. Based on multi-year observational data from 11 hydrological stations, the study demonstrates that current climatic conditions are characterized by a 1.5–2.0 °C rise in mean annual air temperature relative to 1961–1990, a marked decrease in snow cover depth, and a shortened snow-cover duration. These changes reduce the water yield of spring floods or transform them into mixed rain–snowmelt events. The mean spring flood runoff depth varies from 17 to 36 mm, with high spatial variability depending on basin morphology. Numerical calculations show that slope inflow duration ranges from 136 to 404 hours, while the limiting 1% slope inflow modules vary from 0.79 to 2.79 m³/s·km². Watershed elevation was identified as the dominant factor controlling spatial differences, whereas the influence of latitude and forest cover is less pronounced. The spatial distribution of the limiting modules shows the highest values in the northern part of the region (Dnieper basin) and in the upper reaches of the Southern Bug, while the lowest values are characteristic of the rivers of the Dnieper basin within Vinnytsia Region. The obtained results form an important scientific basis for assessing spring flood hazards, estimating rare-probability maximum discharges, designing hydraulic structures, and developing river basin management plans for the Vinnytsia Region. The study demonstrates that the observed reduction in spring flood water yield under climate change must be integrated into future regional water management and adaptation strategies. Further research will involve expanding the analysis to additional watersheds within the region using broader empirical datasets.

The objective was to compare the outcomes of dorsal and ventral onlay urethroplasties using buccal mucosal grafts for the treatment of urethral strictures in women, focusing on patency, complications, de novo incontinence, and impact on sexual function. A retrospective analysis was conducted on 65 patients who underwent dorsal (n = 38) and ventral (n = 27) onlay female urethroplasty using a buccal mucosal graft between July 2017 and January 2024 across three centers. Patency was determined by the successful passage of a 16-French cystoscope or by a maximum flow rate exceeding 15ml/s. Median age, etiology, and stenosis characteristics of the two groups were comparable. At the final follow-up, the patency rates for dorsal and ventral onlay female urethroplasty were 92.1% and 92.6% respectively (p = 1.0). There was no significant difference in postoperative maximum flow rates, postvoid residual urine, Female Sexual Function Index scores, Patient Global Impressions of Change scores, and de novo incontinence rates between the groups. The median blood loss was significantly lower in the ventral onlay group than in the dorsal onlay group (10 vs 20ml, p = 0.001). Dorsal and ventral onlay urethroplasties with buccal mucosal graft are safe and effective techniques for managing female urethral stricture, with similar patency, complications, de novo incontinence rates, and improvements in sexual function. Ventral onlay female urethroplasty has been associated with reduced intraoperative bleeding. To the best of our knowledge, this study represents the largest individual comparative cohort in the literature that directly evaluates dorsal and ventral onlay female urethroplasty.

Abstract Introduction By the seventh decade of life, greater than 50% of men will experience lower urinary tract symptoms due to benign prostatic hyperplasia (BPH). Both the surgical and non-surgical treatment options for BPH continue to evolve, with a variety existing in each category. A popular surgical choice for many patients with BPH are endoscopic-based, which include transurethral resection of the prostate (TURP), Rezum, UroLift, and holmium laser enucleation of the prostate (HoLEP). To our knowledge, no other study exists that directly compares outcomes of these four commonly utilized procedures performed at a single institution. Objective This study sought to analyze patients at a single institution who underwent the common procedures for BPH (TURP, Rezum, UroLift, and HoLEP), to hopefully determine a superior option in terms of improvement in urinary symptoms while not affecting sexual function. The aim was to analyze possible associations between demographic, laboratory, radiologic, operative, postoperative, and patient-reported outcomes and general health, sexual health and urinary health outcomes. Methods A single-center retrospective chart review was performed, consisting of 200 patients who had undergone either TURP, Rezum, UroLift, or HoLEP from July 2021 to December 2024. Preoperative and postoperative urinary and sexual function outcome parameters were recorded, including IPSS and SHIM scores, patient-reported symptoms, changes in medications, maximum urinary flow rate (Qmax), and post-void residual volume (PVR). Chi-square and Kruskal-Wallis ANOVA tests were used to determine group differences. P<0.05 was considered statistically significant. Results Patients who underwent HoLEP experienced higher rates of symptomatic improvement (p<0.001) and improvements in Qmax (p<0.001) compared to other groups, with a median improvement in Qmax of 15.6 mL/s. Greater decreases in PVR were seen for HoLEP (42 mL) and TURP (43 mL) compared to Rezum (13 mL) and UroLift (-1.5 mL) (p=0.036). There was no significant difference between groups in development of erectile dysfunction (p=0.915), with an overall rate of 5% that developed erectile dysfunction. Those with higher prostate volumes were more likely to undergo HoLEP (p<0.001), and those with higher preoperative Qmax were more likely to undergo UroLift (p=0.037). Conclusions Our study showed that patients who underwent HoLEP experienced the greatest improvement in symptoms and urinary flow parameters. Both HoLEP and TURP appeared to improve bladder emptying more effectively than Rezum or UroLift. Erectile dysfunction rates were not different between groups and appear consistent with pre-existing literature. Future assessment of ejaculatory function between these four groups may improve physicians ability to properly counsel their patients preoperatively for those who wish to maximally preserve their sexual function. Disclosure No

ObjectiveThis study aimed to evaluate the clinical efficacy and safety of colpocleisis for urinary retention in elderly women with advanced pelvic organ prolapse (POP), with a particular focus on symptom resolution, postoperative voiding function, and perioperative safety.MethodsThis retrospective study included nine elderly women (median age: 79 years) with POP-associated urinary retention who underwent colpocleisis at our institution between January 2019 and December 2024. Colpocleisis was performed only in patients who were not sexually active and did not desire future sexual activity. Urinary retention was defined as the inability to void spontaneously, requiring either intermittent catheterization or placement of an indwelling urethral catheter. All patients underwent a preoperative urodynamic evaluation. Surgical outcomes and the postoperative voiding function were assessed, including the voided volume, maximum urinary flow rate (Qmax), and post-void residual volume (PVR).ResultsEight of the nine patients (89%) achieved spontaneous voiding postoperatively and were successfully weaned from catheterization. One patient with spinal cord injury continued to require catheterization but experienced easier management and an overall improvement in quality of life. No perioperative complications were observed, and no POP recurrence was noted during a median follow-up of three (range: 1-18) months. The median postoperative voided volume, Qmax, and PVR were 175 mL, 15.9 mL/s, and 20 mL, respectively.ConclusionsColpocleisis may represent a safe and effective surgical option in elderly women with POP-related urinary retention. It facilitates spontaneous voiding or simplifies catheter management, contributing to an improved quality of life. Given its minimally invasive, mesh-free nature and short operative time, colpocleisis could be a valuable treatment option for elderly patients with voiding dysfunction who do not wish to preserve sexual function.

We present an algorithm for the numerical simulation of compressible, shocked, viscous flows interacting with geometrically complex elastoplastic materials. A mathematical formulation is considered, where each material has its own equation of state and is governed by its own system of non-linear, inhomogeneous partial differential equations, which are solved simultaneously on the same computational mesh. To this end, we extend an existing algorithm, which was originally devised for inviscid flows interacting with elastoplastic solids, to account for viscous and heat transfer effects at material interfaces. This approach allows for the modeling of problems of interest to this work, where near-wall viscous effects are important to the external aerodynamics of the body, but which may induce a two-way dynamic and thermodynamic interaction with an elastoplastic material. In the special case of negligible two-way interaction, the algorithm reduces to an immersed interface scheme for viscous flow past rigid bodies. For both cases, we demonstrate the accuracy and robustness of the method through a wide range of multi-dimensional test problems. We demonstrate that the elastoplastic multi-physics simulations can accurately capture the external viscous fluid dynamics flow, while also being able to resolve the behavior of the substrate and interior of the geometry. For the rigid body simulations, we also highlight the differences in the solution when compared to the inviscid case. In all cases, the method operates on a single computational Cartesian mesh and integrates seamlessly with adaptive mesh refinement.

Outpatient surgery is now common in surgical procedure for stress urinary incontinence especially mid-urethral slings (MUS). However, this type of management requires a better selection of patients. The objective of this study was to find predictive factors and a reliable predictive model for the success of outpatient MUS surgery. We carried out a single-center retrospective study between 2013 and 2018 including female patients planned as outpatient for MUS placement for urinary incontinence. Predictive factors and a preoperative predictive model of outpatient success for this surgery were assessed. Overall, 84 patients were included, the mean (standard deviation) age and body mass index (BMI) were respectively 51.9 years (10.9) and 24.7 (4.2). 58 (69%) presented a successful outpatient procedure. In the multivariate analysis, BMI, postoperative visual analogic scale, use of tramadol, preoperative maximum urine flow (Qmax) and surgery duration were predictive of outpatient success (respectively OR [95%CI]= 0.8[0.7-0.9], 0.6[0.4-0.9], 0.1[0.1-0.7], 2.1[1.2-4.2] and 0.9[0.8-0.9]). A pre-operative predictive model including BMI and Qmax had an area under the curve of 0,71. The best performing threshold for the BMI was 24.5kg/m2 and for Qmax was 29.5ml/sec with an 86% prediction rate for outpatient success. We evidenced that low BMI, high preoperative Qmax, short operating time, low postoperative pain, and no use of tramadol were predictive of successful ambulatory care. In addition, a model combining BMI and urinary flow was highly predictive of ambulatory success for patients who underwent MUS placement. External validation is needed.

Overactive bladder (OAB) symptoms are prevalent in patients with bladder outlet obstruction (BOO). Although the pathogenesis of OAB in men with BOO is still under investigation, OAB symptoms might persist following an outflow surgery. It is, thus, crucial to prognosticate preoperatively the outcome of a deobstructive operation. This review aims to systematically investigate the preoperative factors that could prognosticate the persistence of OAB symptoms following deobstruction surgery in males. This is a systematic review of the current literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Randomised controlled trials and observational studies of both prospective and retrospective design were considered eligible for the analysis. The Quality in Prognosis Studies tool was used for assessing the risk of bias. Thirty studies, involving 8043 patients who had persistent storage symptoms following surgical BOO relief, were included. Across adjusted analyses, older age and a higher baseline storage symptom burden were the most frequently associated factors, though findings were inconsistent. Urodynamic measures such as detrusor overactivity, bladder capacity, and detrusor contractility showed heterogeneous results, with some positive and some protective signals. Other factors (eg, prostate volume, prostate-specific antigen, maximum flow rate, postvoid residual, and comorbidities) were uniformly null. Overall certainty of evidence was very low, reflecting inconsistency, imprecision, and reliance on single-study signals. Current evidence is of limited quality; no preoperative factor demonstrated robust prognostic value. Older age and a greater storage symptom burden may be associated with persistence in some adjusted models, whilst urodynamic prognostic factors remain uncertain.

With the continuous advancement of deep oil and gas resource development, the evolution of permeability characteristics for sandstone under high temperature and high-pressure conditions has become critical scientific issues urgently to be addressed. This study conducted permeability tests on sandstone specimens with different inlet pressures, confining pressures, and temperatures, combined with COMSOL Multiphysics multi-field coupling numerical simulations. Applying thermal-hydraulic-mechanical coupling analysis methods, the variation characteristics and evolution mechanisms of sandstone permeability were investigated. The experimental results show that the permeability of sandstones exhibits significant nonlinear decreasing characteristics under temperature-confining pressure coupling effects. When temperature increases from 20 to 95 °C, the reduction of flow rate reaches 78.1% and 86.8% under the confining pressures of 10 and 60 MPa, respectively. The influence of confining pressure on permeability is mainly concentrated in the stage of low confining pressure due to the pore compression effects. The heterogeneous numerical model based on the Weibull distribution effectively reproduced the experimental results. The numerical simulation results reveal that the multi-field coupling mechanisms of sandstone permeability evolution: confining pressure directly alters pore structures through mechanical compression and serves as the dominant factor controlling permeability performance; temperature regulates pore channels through thermal expansion effects while simultaneously affecting fluid property parameters. When confining pressure increases from 10 to 60 MPa, the maximum flow rate attenuation reaches one order of magnitude, far exceeding the influence of temperature effects. These research findings provide important theoretical foundation and technical support for deep oil and gas reservoir development.

Objective: The current study aimed to develop predictive models based on noninvasive clinical parameters to facilitate the early identification and stratification of patients with suspected bladder outlet dysfunction (BOD), thereby reducing the need for invasive diagnostic procedures. Materials and Methods: This retrospective study included 307 male patients with lower urinary tract symptoms (LUTS) refractory to medical therapy who were enrolled between January 2001 and May 2022. To assess the predictive performance of the model in an independent cohort, the dataset was randomly divided into the training set (70%) for model development and the test set (30%) for external validation. A two-stage modeling approach was adopted: Stage 1 involved detecting BOD, and stage 2 focused on identifying specific BOD subtypes. Backward stepwise logistic regression was conducted for model derivation, with internal validation performed using 5-fold cross-validation repeated 20 times. Clinical nomograms and a clinical decision-making framework were constructed based on the final modeling results. Results: In stage 1, the derived BOD model for detecting suspected BOD incorporated maximum flow rate, voided volume, intravesical prostatic protrusion (IPP), and prostatic urethral angle (PUA) as predictors. In stage 2, the derived benign prostatic obstruction (BPO) model included post-void residual (PVR), total prostate volume (TPV), and IPP as predictors. We also constructed nomogram to broadly screening BOD by the combination of maximum flow rate, voided volume, IPP, and PUA, a total score of ≥107 yielded the probability of 0.78 to identify BOD of 0.78. Subsequently, by combining PVR, TPV, and IPP, a total score of ≥39 yielded the probability of 0.35 to discriminate BPO. However, the BOD model (0.47) had a relatively low specificity, and the BPO model (0.58) had a lower sensitivity. Thus, these findings should be considered when applying the models in clinical practice. Conclusions: The results of this study revealed that using the clinical non-invasive parameters to create models can only yield a low sensitivity and low specificity for identifying BPO and the other BOD subtype. In patients with LUTS and small to moderate prostate volume, invasive video urodynamic study is still necessary when invasive treatment modality is recommended.

ObjectiveTo compare and analyze differences in the clinical effect and postoperative urodynamic indexes of microsurgery combined with covering new urethra by multilayer fascial tissue coverage tissues and conventional surgery alone in the treatment of male children with hypospadias.MethodsA total of 80 male children with penile hypospadias who were hospitalized in Baoding Hospital, Beijing Children's Hospital Affiliated to Capital Medical University were randomly divided into two groups, with 40 in each group. Children in the study group underwent microsurgery combined with covering new urethra by multilayer fascial tissue coverage tissues, while those in the control group were provided with traditional tubularized incised plate (TIP) urethroplasty alone. Further comparative analysis was performed on the operation effect, operation time, total intraoperative bleeding, postoperative length of stay in the hospital and the incidence of surgical complications between the two groups. All male children were followed up for 6 months to compare and analyze the changes of urodynamic parameters such as maximum urinary flow rate (Qmax), mean urinary flow rate (Qavc), post-void residual urine (PVR) before and after surgery.ResultsThere were statistically significant differences that the operation time (p = 0.03) was longer while the postoperative length of stay in the hospital (p = 0.000) was shorter in the study group than those in the control group. The effective rate of the study group was 97.50%, while that of the control group was 82.50%, with statistically significant difference (p = 0.025). The incidence of surgical complications was 7.50% in the study group and 25.00% in the control group 3 months after operation (p = 0.034). There was statistically significant difference that the HOSE score of the study group was significantly higher than that of the control group (p = 0.000). Meanwhile, there was no significant difference in indicators such as Qmax, Qavc and PVR between the two groups before surgery; while the levels of Qmax and Qavc in the study group were higher than those in the control group 6 months after surgery, with statistically significant difference (p = 0.000).ConclusionMicrosurgery combined with covering new urethra by multilayer fascial tissue coverage tissues has certain clinical value in the treatment of male children with hypospadias, which shows good therapeutic effect, shorter length of stay in the hospital, lower incidence of postoperative complications, and significantly improved urodynamic indicators, despite slightly complicated operation and relatively longer duration of operation.

Objectives: The relationship between pulmonary function tests (PFT) performed while awake and sleep-related breathing disorders is not yet well defined. This study aimed to examine the potential of flow-volume curve abnormalities in assessing both the presence and severity of obstructive sleep apnea syndrome. Methods: This retrospective study reviewed medical records of patients evaluated for suspected obstructive sleep apnea syndrome (OSAS) between May 2011 and April 2013. Among 141 patients with available PFT, 99 were diagnosed with OSAS, and 42 were normal based on polysomnography results. Patients were classified into OSAS and control groups, and pulmonary function parameters, including flow-volume curve features, were analyzed. Results: Of the OSAS patients, 80 (80.8%) were male, while 22 (52.4%) males were present in the control group, which consisted of patients not diagnosed with obstructive sleep apnea syndrome. Among pulmonary function test parameters, the ratio of maximal mid-expiratory flow to forced vital capacity (FEF25-75/FVC) was lower in the obstructive sleep apnea syndrome group than in the control group (P<0.05). Patients with the sawtooth sign showed significantly higher apnea-hypopnea index, apnea-hypopnea index during rapid eye movement sleep, and total apnea scores (P<0.05). The presence of sawtooth signs in the flow-volume loop was useful for identifying more severe cases of obstructive sleep apnea syndrome. Conclusions: The complex pathophysiology of obstructive sleep apnea syndrome complicates the identification of patients who need polysomnography. Flow-volume curve abnormalities, indicating airway instability in the upper respiratory tract, are common in these patients and may serve as early indicators of obstructive sleep apnea syndrome.

This study aimed to evaluate the perioperative safety and functional outcomes of high-power holmium laser enucleation of the prostate (HoLEP) in patients with benign prostatic hyperplasia (BPH) and long-term indwelling urinary catheter (IUC) use, with a specific focus on the impact of catheter duration on postoperative outcomes. A retrospective analysis was conducted on 380 patients who underwent HoLEP between 2016 and 2022, stratified into two groups based on catheter duration: long-term (≥ 28 days; Group 1) and short-term catheterization (Group 2). Demographic, intraoperative, and follow-up data were collected. Functional outcomes, including International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), and post-void residual (PVR), were assessed preoperatively and during follow-up at 3 and 12 months. Both groups demonstrated significant and sustained improvement in voiding function and symptom scores following HoLEP. Although perioperative metrics, such as operative time, hospital stay, and catheter removal time, were comparable, Group 1 had longer enucleation times (p = 0.02). No difference in postoperative complication rate was noted. At 3 months, Group 2 exhibited superior symptom relief (IPSS: 10 vs. 12, p = 0.01), though Qmax and PVR were similar. No patients in either group required re-catheterization postoperatively. By 12 months, functional outcomes converged between groups. Multivariate analysis showed that catheter duration predicted poorer symptomatic recovery one year after surgery (OR 0.786, p < 0.001). HoLEP is effective and safe for patients with BPH and preoperative catheterization. However, prolonged catheterization negatively impacts early symptom recovery. Early surgical intervention should be considered to optimize long-term outcomes and prevent catheter-related complications.

The "swipe" technique for prostatic urethral lift: a comparative analysis of 200 patients in a prospective cohort.

IntroductionTo assess the relationship between body mass index (BMI) and BMI z-scores with lung function parameters in children with asthma, aiming to provide scientific evidence for individualized treatment and management strategies.MethodsWe enrolled 328 children with asthma during acute exacerbation. The BMI and BMI z-scores were analyzed in relation to lung function parameters, including maximum vital capacity (VCmax), forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), peak expiratory flow (PEF), maximal mid-expiratory flow rate (MMEF), and instantaneous flows at 25%, 50%, and 75% of maximal expiratory flow (MEF25, MEF50, MEF75). Both linear regression and piecewise regression models were used to identify linear associations and potential threshold effects.ResultsBMI showed significant positive linear correlations with VCmax, FVC, FEV1, MEF50, MEF75, and MMEF, while BMI z-scores demonstrated positive linear associations with VCmax, FVC, FEV1, MEF25, MEF50, and MMEF. After adjusting for age, sex, immunoglobulin E (IgE), eosinophil count (EOS), fractional exhaled nitric oxide (FeNO), and asthma severity, both BMI and BMI z-scores remained positively associated with VCmax, FVC, and FEV1. Piecewise regression analysis revealed significant threshold effects in the relationships between BMI z-scores and VCmax, FVC, FEV1, PEF, MEF25, MEF50, MEF75, and MMEF. Below a z-score of ~2.3–3.9, BMI z-score was positively associated with pulmonary function. Above this threshold, the association reversed; for instance, FEV1 decreased by 9.7% (β = −9.69, 95% CI: −18.93 to −0.46) and PEF decreased by 12.2% (β = −12.17, 95% CI: −21.12 to −3.22) for every unit increase in BMI z-score beyond 3.945.ConclusionA nonlinear relationship exists between BMI z-scores and lung function parameters in children with asthma. Weight-guided interventions may enhance lung function and asthma control.

Continuous manifold systems (CMS) are widely used for energy and mass transfer. The flow distribution of the branch ports directly affects the flow pattern of the chamber. However, the current understanding of the flow distribution in CMS under unsteady flow conditions and the optimization of their geometry is still limited. In this study, three-dimensional numerical simulations were performed to investigate the flow distribution of branch ports under unsteady flow conditions. Moreover, this study analyzed the effects of the geometric parameters of CMS on the non-uniformity coefficient (α) and total pressure drop (ΔP) under the maximum inlet flow condition (Q = 23.40 L/s). The results show that (i) from 0 to 12 s, the flow ratio (β) at the branch ports decreases in the direction of the fluid flow and then increases in the same direction from 12 to 90 s; (ii) as flow growth coefficient (η) increases, α for the maximum inlet Reynolds number (Re) increases slightly, and the difference in α corresponding to the same Re at different time points decreases; (iii) the increase in area ratio (AR) causes the flow rate of the first branch port to rise and the flow of the terminal branch port to decrease. The value of α increases linearly with AR: α = 0.23AR−0.11; (iv) The most economical approach involves adopting a linearly tapered branch ports width design with b 1/b 10 = 1.50, which decreases α by 65.04% while increasing the ΔP by 9.93% compared to the original design. This study can provide a reference for engineers in designing CMS with unsteady flow.