Search Results (389)

Membrane technology is primarily used for the separation and purification of biotechnological products, which contain proteins and enzymes. Membrane fouling during crossflow filtration remains a significant challenge. This study aims to initially validate crossflow filtration models, particularly related to pore-blocking mechanisms, through a comparative analysis with dead-end filtration models. One crossflow microfiltration (MF) and six consecutive ultrafiltration (UF) stages were implemented to concentrate laccase extracts from Pleurotus ostreatus 202 fungi. The complete pore-blocking mechanism significantly impacts the MF, UF 1000, UF 100 and UF 10 stages, with the highest related filtration constant (Kb_F) estimated at 12.60 × 10⁻⁴ (m⁻¹). Although the intermediate pore-blocking mechanism appears across all filtration stages, UF 100 is the most affected, with an associated filtration constant (Ki_F) of 16.70 (m⁻¹). This trend is supported by the highest purification factor (6.95) and the presence of 65, 62 and 56 kDa laccases in the retentate. Standard pore blocking occurs at the end of filtration, only in the MF and UF 1000 stages, with filtration constants (Ks_F) of 29.83 (s^−0.5m^−0.5) and 31.17 (s^−0.5m^−0.5), respectively. The absence of cake formation and the volume of permeate recovered indicate that neither membrane was exposed to exhaustive fouling that could not be reversed by backwashing. Full article

Magnetic nanoparticles (MNPs), especially iron oxide (Fe₃O₄), display distinctive superparamagnetic characteristics and elevated surface-area-to-volume ratios, facilitating improved physicochemical interactions with solutes and pollutants. These characteristics make MNPs strong contenders for use in water treatment applications. This research investigates the application of iron oxide MNPs synthesized via co-precipitation as innovative draw solutes in forward osmosis (FO) for treating synthetic produced water (SPW). The FO membrane underwent surface modification with sulfobetaine methacrylate (SBMA), a zwitterionic polymer, to increase hydrophilicity, minimize fouling, and elevate water flux. The SBMA functional groups aid in electrostatic repulsion of organic and inorganic contaminants, simultaneously encouraging robust hydration layers that improve water permeability. This adjustment is vital for sustaining consistent flux performance while functioning with MNP-based draw solutions. Material analysis through thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) verified the MNPs’ thermal stability, consistent morphology, and modified surface chemistry. The FO experiments showed a distinct relationship between MNP concentration and osmotic efficiency. At an MNP dosage of 10 g/L, the peak real-time flux was observed at around 3.5–4.0 L/m²·h. After magnetic regeneration, 7.8 g of retrieved MNPs generated a steady flow of ~2.8 L/m²·h, whereas a subsequent regeneration (4.06 g) resulted in ~1.5 L/m²·h, demonstrating partial preservation of osmotic driving capability. Post-FO draw solutions, after filtration, exhibited total dissolved solids (TDS) measurements that varied from 2.5 mg/L (0 g/L MNP) to 227.1 mg/L (10 g/L MNP), further validating the effective dispersion and solute contribution of MNPs. The TDS of regenerated MNP solutions stayed similar to that of their fresh versions, indicating minimal loss of solute activity during the recycling process. The combined synergistic application of SBMA-modified FO membranes and regenerable MNP draw solutes showcases an effective and sustainable method for treating produced water, providing excellent water recovery, consistent operational stability, and opportunities for cyclic reuse. Full article

Background/Objectives: Current dosing recommendations for piperacillin/tazobactam suggest adjustments only for patients with creatinine clearance (CrCl) below 40 mL/min, potentially neglecting the variability in drug exposure among patients with a CrCl greater than 40 mL/min. This study aimed to develop a population pharmacokinetic (PK) model for piperacillin/tazobactam and explore optimal dosage regimens tailored by renal function and pathogen susceptibility. Methods: Twelve healthy adults received a single intravenous dose of piperacillin/tazobactam (4 g/0.5 g). Population PK models were developed using nonlinear mixed-effects modeling. Monte Carlo simulations were conducted to identify optimal dosing regimens across various renal functions and MIC levels, guided by pharmacodynamic targets defined as the percentage of time that free drug concentrations exceed the minimum inhibitory concentration (fT_>MIC). Results: PK profiles of both drugs were best described by two-compartment models. Estimated glomerular filtration rate (eGFR) adjusted by body surface area and body weight were identified as significant covariates influencing drug clearance and peripheral volume of distribution. Simulations showed that the standard dosing regimen (4/0.5 g q6h with 30 min infusion) achieved a 90% probability of target attainment (PTA) for 50%fT_>MIC at MIC values up to 4 mg/L in patients with normal renal function. However, this regimen often did not achieve a 90% PTA for stringent targets (100%fT_>MIC, 100%fT_>4MIC) or higher MICs, particularly in patients with eGFR ≥ 130 mL/min. Conclusions: These findings suggest current dosing regimens may be inadequate and highlight the potential of alternative strategies, such as extended or continuous infusion, which warrant further investigation in clinical populations to optimize therapeutic outcomes. Full article

Geological surveys have vital importance at the planning stage of dammed reservoir construction projects. The results of these surveys determine the majority of the technical solutions adopted in the construction design to ensure the proper safety and stability parameters of the structure during water damming. Where the ground type is found to be different from what is expected, the construction project may be delayed or even cancelled. This study analyses issues and design modifications caused by the identification of different soil conditions during the construction of four new flood control reservoirs in the Nysa Kłodzka River basin in south-western Poland. The key findings are as follows: (1) a higher density of exploratory boreholes in areas with potentially fractured rock mass is essential for selecting the appropriate anti-filtration protection; (2) when deciding to apply deep piles, it is reasonable to verify, at the planning stage, whether they can be installed using the given technology directly at the planned site; (3) inaccurate identification of foundation soils under the dam body can lead to significant design modifications—in contrast, a denser borehole grid helps to determine the precise elevation of the base layer, which is essential for reliably estimating the volume of material required for the embankment; (4) in order to correctly assess the soil deposits located, for instance, in the reservoir basin area, it is more effective to use test excavations rather than relying solely on borehole-based investigations—as a last resort, test excavations can be used to supplement the latter. Full article

Background/Objectives: Robot-assisted radical cystectomy (RARC) has become the primary approach for treating bladder cancer, replacing the traditional open procedure. The robotic approach, when combined with ureterocutaneostomy (UCS), offers significant advantages for octogenarians, who are at increased risk for perioperative complications. Methods: This observational, prospective, multicenter analysis is based on data from the Italian Radical Cystectomy Registry (RIC), collected from January 2017 to June 2020 across 28 major urological centers in Italy. We analyzed consecutive male and female patients undergoing radical cystectomy (RC) and urinary diversion via the open, laparoscopic, or robot-assisted technique. Inclusion criteria: patients aged 80 years or older, with a WHO Performance Status (PS) of 2–3, an American Society of Anesthesiologist score ≥3, a Charlson Comorbidity Index (CCI) ≥ 4, and a glomerular filtration rate (GFR) <60 mL/min. Results: A total of 128 consecutive patients were included: 41 underwent RARC with UCS (Group 1), 65 open RC (ORC) with UCS (Group 2), and 22 laparoscopic RC (LRC) with UCS (Group 3). The cystectomy operative time was longer in robotic surgeries, while the lymph node dissection time was shorter. RARC with UCS showed statistically significant advantages in terms of lower median estimated blood loss (EBL), transfusion rate, and length of hospital stay (LOS) compared to open and laparoscopic procedures. Intra- and postoperative complications were also lower in the RARC groups. Conclusions: Robotic cystectomy in high-volume referral centers (≥20 cystectomies per year) provides the best outcome for fragile patients. Beyond addressing the baseline pathology, RARC with UCS may represent a leading option, offering oncological control while reducing complications in this vulnerable age group. Full article

Background: Cardiovascular diseases (CVDs) remain a leading cause of morbidity and mortality, despite advances in treatment. Early detection of vascular aging is critical, as preclinical atherosclerosis often remains undiagnosed. AI-determined vascular age, originally developed using carotid-femoral pulse wave velocity (cf-PWV), may help to identify individuals at elevated risk. This study aimed to evaluate the clinical utility of an alternative AI-determined vascular age model based on the arterial velocity pulse index (AVI) and arterial pressure volume index (API) in a Japanese hospital-based cohort. Methods: This retrospective, exploratory study analyzed electronic health records of 408 patients from Yokohama City University Hospital. This study was approved by the Clinical Research Ethics Committee (approval numbers: B180300040, F240500007), and patient consent was obtained through an opt-out process. AI-determined vascular age was estimated using a Generalized Additive Model (GAM) with backward stepwise regression, substituting cf-PWV with AVI and API. Correlations with chronological age were assessed, and comparisons of cardiovascular and renal function markers were performed across age-stratified groups. Results: AI-determined vascular age showed a strong correlation with chronological age (p < 0.05). Significant differences were observed in cardiac diastolic function parameters, B-type natriuretic peptide (BNP), and estimated glomerular filtration rate (eGFR) between the highest and lowest quintiles of AI-determined vascular age. Conclusions: AI-determined vascular age using AVI and API appears to be a feasible surrogate for cf-PWV in clinical settings. This index may aid in stratifying vascular aging and identifying individuals who could benefit from early cardiovascular risk management. Full article

Background: Several studies have shown that total kidney volume (TKV) measurements may serve as a non-invasive imaging biomarker for monitoring and predicting the progression of autosomal dominant polycystic kidney disease (ADPKD) in children. Methods: This study aimed to evaluate the relationship between height-adjusted TKV (htTKV), estimated glomerular filtration rate (GFR), and blood pressure, assessed using 24 h ambulatory blood pressure monitoring (ABPM), in children with early-stage ADPKD. The study was conducted with 72 children, mean age 12.46 ± 3.76 (5.42–17.92). Results: Hypertension (HT) was diagnosed in (20) 28% of children. ABPM allowed the identification of previously undiagnosed HT in 12 (16.7%) children. Decreased GFR was demonstrated in 10 (14%) children, and hyperfiltration in 5 (7%) children. Significantly higher htTKV and calculated TKV z-score and more frequent decreases in GFR were observed in hypertensive children (p = 0.018; 0.020 and 0.010, respectively). The study demonstrated a significant inverse correlation between htTKV and GFR (r −0.25; p = 0.032). The TKV z-score showed a very good correlation with all ABPM parameters, except for DBP and DBP z-score during the day. Receiver operating curve (ROC) analysis showed that htTKV and TKV z-score had good diagnostic value for predicting a decline in GFR (AUC 0.808, p < 0.001), but were not useful for predicting the onset of HT (AUC 0.697, p = 0.010). Conclusions: There is a relationship between TKV, GFR, and blood pressure parameters in children with early-stage ADPKD. The TKV z-score can be useful for predicting GFR decline. Children with ADPKD and increasing TKV require careful blood pressure monitoring. Full article

As the population of adults with congenital heart disease (ACHD) continues to grow, a significant and often underrecognized complication is the development of cardiorenal syndrome (CRS)—a complex, bidirectional interaction between cardiac and renal dysfunction. While CRS has been extensively studied in acquired heart failure, its manifestations and implications in ACHD remain insufficiently understood. Emerging data suggest that renal dysfunction is highly prevalent in ACHD, with significant associations to adverse outcomes regardless of cardiac lesion type or functional status. This review explores CRS within three key physiologic categories in ACHD: patients with a systemic right ventricle, those with a subpulmonary right ventricle, and those with Fontan circulation. Each subgroup presents unique hemodynamic challenges that affect renal perfusion, filtration pressure, and systemic congestion, contributing to both acute and chronic renal impairment. The utility of renal biomarkers such as albuminuria, cystatin C, and estimated glomerular filtration rate (eGFR) is emphasized, alongside the importance of early detection and multidisciplinary management. Heart failure therapy tailored to congenital anatomy, neurohormonal modulation, and careful volume control remain the cornerstones of treatment, while transplantation strategies must consider the potential for irreversible end-organ damage. Given the profound implications of CRS on quality of life and survival, a comprehensive understanding of its pathophysiology and management in ACHD is critical to optimizing long-term outcomes in this increasingly complex patient population. Full article

This study proposes practical methods for estimating the moisture content of sludge, represented by the cake moisture, in the filter press dewatering process. Because the cake moisture and filtrate volume are difficult to measure directly, the proposed approaches utilize indirectly measurable data, including drain outlet images and the differential pressure during the compression phase. By analyzing the correlations between these parameters and the cake moisture, estimation models were developed using mathematical approximations. In the image-based approach, image processing techniques were applied to isolate the dewatered region, and the relationship between the pixel count and actual filtrate volume was analyzed to estimate the cake moisture based on the calculated filtrate volume per minute. In the pressure-based approach, two models were proposed: one that directly estimates the cake moisture from the differential pressure, and another that models the relationship among the differential pressure, filtrate volume, and cake moisture. Unlike complex machine learning techniques, the proposed methods employ simple and interpretable mathematical functions, offering both practicality and reliability. Validation using real-world operational data confirmed the accuracy and effectiveness of the proposed approaches. Full article

This paper presents a novel small-scale system for drinking water treatment from surface waters, designed to rely on gravity as the only source of energy driving the treatment process. The pilot-scale setup, designed for a flow rate of 0.5 L/s, was tested at the Cornell University Water Filtration Plant (CWFP) for a total period of 5 months of operation. The experiments evaluated the influence of selected process parameters on system performance. The identified best operation practices were used to complete a comparative study against CWFP’s full-scale treatment process and to conduct a performance assessment in the context of various legislative landscapes. The objective of the work was to determine both the advantages and disadvantages of the proposed technology over established solutions. Over the study period, the average turbidity of the produced water was equal to 0.54 NTU. The pilot complied with the United States Environmental Protection Agency (US EPA) turbidity standard of <0.3 NTU 47.1% of the time and <1 NTU for 89.9% of the time, thus falling short of the standard of <0.3 NTU 95% of the time and <1 NTU 100% of the time. For 99.5% of the time, it complied with the World Health Organization turbidity guideline of <5 NTU for chlorination treatment. The benchmark conventional system outperformed the tested prototype, complying with the US EPA standards for the entire duration of the study. The tested process also generated a waste stream, which accounted on average for more than 10% of the total raw water volume. Full article

Fibrous biomaterials are essential in biomedical engineering, tissue engineering, and filtration due to their specific transport and mechanical properties. Fluid flow through these materials is critical for their function. However, many biological fluids exhibit non-Newtonian behavior, characterized by micro-rotational effects, which traditional models often overlook. The current study presents a machine learning (ML) framework for the prediction and understanding of hydraulic permeability in fibrous biomaterials with a micropolar fluid. A dataset of 1000 numerical simulations was generated by varying the micropolar fluid properties and the fiber volume fraction in a periodic porous structure with nine parallel cylindrical fibers in a square lattice. Six powerful ML algorithms were deployed: Decision Trees (DT), Random Forests (RF), XGBoost, LightGBM, Support Vector Regression (SVR), and k-Nearest Neighbors (kNN). The balance of predictive capacity to unseen data values (tracking $R^2$ values and error metrics) with computational efficiency for all algorithms was assessed. The best-performing ML algorithm was subsequently used to interpret the decisions made by the model using Shapley Additive exPlanations (SHAP) analysis and understand the role of feature importances. The SHAP findings highlight the potential of ML in capturing complex fluid interactions and guiding the design of advanced fibrous biomaterials with optimized hydraulic permeability. Full article

To mitigate the influence of wellbore heat transfer on the physicochemical properties of water-based fracturing fluids in the high-temperature environments of low-permeability shale reservoirs, this study investigates the fluid filtration behavior of water-based fracturing fluids within the wellbore under such reservoir conditions. A wellbore heat-transfer model based on solid–liquid coupling was constructed in order to analyse the effects of different reservoir and wellbore factors on fluid properties (viscosity and filtration volume) in the water-based fracturing fluids. Concurrently, boundary conditions and control equations were established for the numerical model, thereby delineating the heat-transfer conditions extant between the water-based fracturing fluid and the wellbore. Furthermore, molecular dynamics theory and microgrid theory were utilised to elucidate the mechanisms of the alterations of the fluid properties of the water-based fracturing fluids due to wellbore heat transfer in low-permeability shale reservoirs. The findings demonstrated that wellbore heat transfer in low-permeability shale reservoirs exerts a pronounced influence on the fluid viscosity and filtration volume of the water-based fracturing fluids. Parameters such as wellbore wall thickness, heat-transfer coefficient, radius, and pressure differential introduce distinct variation trends in these fluid properties. At the microscopic scale, the disruption of intermolecular hydrogen bonds and the consequent increase in free molecular content induced by thermal effects are the fundamental mechanisms driving the observed changes in viscosity and fluid filtration. These findings may offer theoretical guidance for improving the thermal stability of water-based fracturing fluids under wellbore heat-transfer conditions. Full article

High-sodium/low-potassium in the modern diet, potassium excretion, and sodium retention have all been implicated in hypertension. Objectives: This study investigated the differential effects of potassium (K⁺) supplementation on blood pressure, renal function, and oxidative stress in two experimental hypertensive rat models: L-NAME-induced (nitric oxide synthase inhibitor-induced hypertension presenting with reduced NO bioavailability, endothelial dysfunction, vasoconstriction) and DOCA-salt-induced hypertension (deoxycorticosterone acetate + salt mimics volume-dependent hypertension of hypermineralocorticoidism, low renin, high sodium retention and severe cardiac fibrosis and oxidative stress). Methods: Male Sprague Dawley rats were treated with L-NAME or DOCA-salt, with or without 0.75% KCl dietary supplementation for eight weeks. Blood pressure, vascular reactivity, serum electrolytes, renal function markers, and malondialdehyde (MDA) levels were evaluated. Results: Potassium supplementation significantly reduced (20%) mean arterial pressure and (80%) oxidative stress markers in the L-NAME model but not in the DOCA-salt model. In both hypertensive models, K⁺ reduced (15%) vascular contractile response to phenylephrine, though it did not improve acetylcholine-induced vasodilation. Notably, K⁺ supplementation improved glomerular filtration rate (eGFR), sodium–potassium ratio, and renal biomarkers (urea and creatinine) in the L-NAME model, suggesting nephroprotection. However, in the DOCA-salt group, these markers either remained unchanged or worsened. Conclusions: These findings indicate that the antihypertensive and renoprotective effects of potassium are model-specific and depend on the underlying pathophysiological mechanisms, such as nitric oxide bioavailability and mineralocorticoid sensitivity. Dietary potassium may be more effective in patients with endothelial dysfunction-dominant hypertensive subtypes compared with volume-dependent hypertension and may call for K⁺ supplementation studies to be stratified by hypertension subtype. Full article

Double-filtration plasmapheresis (DFPP) is a plasma-exchange modality that allows selective clearance of high-molecular-weight proteins, potentially minimizing albumin loss and the need for volume replacement. Reports concerning DFPP use in dogs are scarce. This study evaluates the quantitative net loss of different plasma proteins fractions in an ex vivo model using canine blood processed via DFPP. DFPP treatment with INUSpheresis^® processing 1.5, 2, and 3 plasma volumes (PVs) was performed. Plasma proteins fractions were measured in the reservoir blood bag at baseline (pre-treatment) and in the effluent bag at the end of each target PV exchanged to calculate the net loss of selected plasma proteins. At 1.5 PV, net globulin and albumin loss was 41 and 25% respectively. At 3 PV, net globulin and albumin loss was 47 and 40%, respectively. Fibrinogen concentration was unmeasurable low in the reservoir blood bag after processing 1.5 PV. INUSpheresis^® allows selective plasma proteins removal, with a sparing effect on albumin at 1.5 PV. Selectivity is, however, progressively reduced with incremental target PV. A description of five DFPP treatments in three dogs is additionally presented. Semi-selective protein removal was also demonstrated in vivo, with a significantly lower percentage reduction in albumin compared to total globulin (p = 0.01) and fibrinogen (p = 0.007). Full article

Drip irrigation is a widely spreading technology, mainly due to its high water-use efficiency. This technique requires a filtration process that exhibits cyclical behavior where both filtration and backwashing modes repeat. In filtration, pressure increases with time due to the particle retention up to a preset value. In backwashing, the flow is reversed to clean the filter. Different design strategies to reduce energy and water consumption have been proposed, but their practical effects are not yet clear. Here, a global analysis method based on the classification of the time evolution of the pressure curve in filtration mode was developed. Energy and water use efficiency indices were defined and evaluated under different scenarios. More design options can be undertaken to reduce the consumption of energy than of water. The decrease in the pressure drop for clean filter conditions arose as the best option to increase energy efficiency (in a realistic scenario, a reduction of 20% in the pressure drop with tap water resulted in a reduction of 7.6% in the energy consumption per volume of filtered water). Precise backwashing times and flow rates were essential to improve water use efficiency (e.g., doubling the backwashing time led to a 4.5% decrease in water use efficiency). Full article