Nanofiltration is a green purification method for juice valorization; however, its efficiency is often limited by membrane fouling. Ultrafiltration is commonly applied as pretreatment to mitigate fouling during juice nanofiltration. This study evaluated the separation of L-citrulline from watermelon rind juice using nanofiltration with and without a prior ultrafiltration step. The juice was pre-clarified using a 50 kDa ultrafiltration membrane and subsequently filtered through a polyamide nanofiltration membrane at pressures of 10-40 bar. Membrane performance and fouling behavior were analyzed in terms of permeate flux, solute rejection of L-citrulline and D-glucose, total soluble solids (TSS), total dissolved solids (TDS), salinity, electrical conductivity (EC), and Hermia's fouling models. During nanofiltration without pretreatment, rapid cake layer formation limited the permeate flux to below 15.0 L·m- 2·h- 1 and the volume concentration factor (VCF) to approximately 7. In contrast, the use of ultrafiltration prior to nanofiltration significantly improved process performance, increasing the flux to 84.7 L·m- 2·h- 1 at 35 bar and enabling concentration up to VCF 11.56. L-citrulline exhibited negative rejection (Ri < 0), resulting in higher permeate concentrations after the combined process (1,773 mg·L- 1), while D-glucose remained strongly rejected (Ri > 74%). The permeate obtained from the combined process also showed reduced levels of TSS, TDS, salinity, and EC (2.0 °Brix, 2,203.0 ppm, 0.22%, and 4,370.0 µS·cm- 1, respectively). Fouling analysis revealed a transition in the dominant mechanism from cake filtration to complete blocking when ultrafiltration was applied prior to nanofiltration. These findings highlight the effectiveness of integrating ultrafiltration as a pretreatment step to enhance nanofiltration performance for selective L-citrulline recovery from watermelon rind. PRACTICAL APPLICATIONS: This study demonstrated that integrating ultrafiltration with nanofiltration effectively reduced sugars while concentrating L-citrulline in watermelon rind juice, making the resulting permeate suitable for functional beverage and nutraceutical formulations. The proposed membrane-based process offers a scalable, clean-label strategy for valorizing fruit-processing by-products, thereby supporting sustainable manufacturing and the development of health-oriented food products.
Perfluoroalkyl and polyfluoroalkyl substances （PFAS） possess desirable properties， including hydrophobicity， oleophobicity， surface activity， and thermal and chemical stability. Their extensive production and widespread application have resulted in the pervasive presence of PFAS in diverse environmental media. However， accumulating evidence indicates that PFAS are persistent， capable of long-range transport， bioaccumulative， and toxic； consequently， their adverse effects on ecosystems and humans are of widespread concern. Aquatic environments serve as a major transport pathway and contamination route for PFAS， making accurate measurement of PFAS levels in water crucial for assessing associated environmental and health risks. However， accurate quantification requires multi-step procedures， including sample filtration， enrichment， nitrogen blow-down concentration， and reconstitution， such as solid-phase extraction （SPE） and accelerated solvent extraction （ASE）. These methods are often labor-intensive and time-consuming. Although research on fully automated SPE technology is increasing， it necessitates installation of online SPE systems， which entail high costs and may present limitations in sample throughput per run. With continuous advancements in mass spectrometry， instrumental sensitivity has improved considerably， making direct injection of water samples for multi-analyte analysis technically feasible. However， reports on the use of direct injection methods for detecting PFAS in water remain limited， and the number of target analytes covered in such studies is relatively small. In this study， a direct injection-ultra performance liquid chromatography-triple quadrupole mass spectrometry （UPLC-MS/MS） method was developed for the determination of 31 PFAS in water. To optimize the chromatographic separation， enhance the detection sensitivity of target analytes， and minimize undesirable adsorption losses， the method was meticulously optimized with respect to solvent selection， injection volume， and syringe filter type. Our method involves the following procedure： 0.5 mL of water is aliquoted， mixed with 0.5 mL of methanol spiked with 2 ng of internal standard， and filtered through a 0.22 μm polypropylene membrane. The PFAS were analyzed by UPLC-MS/MS with an injection volume of 35 µL. The analytes were ionized in electrospray ionization negative mode （ESI-） with scheduled multiple-reaction monitoring （sMRM）. The MS parameters， including precursor and product ions， collision energy， and declustering voltage were optimized. Through optimization of the analytical column and mobile phases， the analytes were separated on an RSLC 120 C18 column with a gradient of methanol and 5 mmol/L ammonium acetate aqueous solution as the mobile phase in a gradient elution program. The results were quantified by the internal standard method. The method demonstrated excellent linearity （R²>0.994） across a defined concentration range. The limits of detection （LODs） and quantification （LOQs） were 0.007 1-3.0 ng/L and 0.024-10 ng/L， respectively. Recoveries at spiked levels of 2， 10， and 500 ng/L ranged from 67.2% to 130.2%， with relative standard deviations （RSDs） of 0.30% to 18%. To quantify the effective equivalence between the enrichment efficiency of SPE and the sensitivity of direct injection methods， a comparative analysis of analyte recovery rates was performed for both approaches. Furthermore， for long-chain PFAS， direct injection demonstrated consistent and favorable recovery performance. The method was applied to analyze PFAS in groundwater samples. The results showed that 24 PFAS were detectable with the total PFAS content （∑PFAS） ranging from 20.6 to 521 ng/L， with perfluorooctanoic acid （PFOA） and perfluorobutanoic acid （PFBA） being the primary pollutants. This approach is simple， rapid， highly sensitive， and provides broad coverage of target analytes， making it suitable for the quantitative analysis of PFAS in urban groundwater. It offers an efficient and reliable technical solution for determining trace-level PFAS in environmental water samples. 本文建立了一种直接进样-超高效液相色谱-三重四极杆质谱测定水中31种全氟/多氟化合物（PFAS）的分析方法。通过对色谱柱、流动相及进样体积等参数的优化，最终确定以RSLC 120 C18色谱柱为分离柱，以甲醇和5 mmol/L乙酸铵水溶液为流动相进行梯度洗脱，在电喷雾负离子模式下，结合分时间段-多反应选择离子监测模式对31种PFAS进行定量分析。当样品进样体积为35 µL时，PFAS在其相应范围内具有良好的线性关系（R²> 0.994），检出限为0.007 1~3.0 ng/L，定量限为0.024~10 ng/L。加标水平为2、10和500 ng/L时，PFAS的回收率为67.2%~130.2%，相对标准偏差为0.30%~18%。应用该方法在10个地下水点位检出24种PFAS，总浓度（∑PFAS）范围为20.6~521 ng/L，其中PFOA和PFBA为主要污染物。该方法简便快捷，目标物覆盖范围广，准确度和灵敏度高，为环境水体中痕量PFAS的测定提供了高效可靠的方法选择。
The coexistence of emulsified oil, dissolved organics, and heavy metal ions in industrial oily wastewater makes one-step treatment highly challenging. Herein, an organic-inorganic co-modified PVDF composite membrane (MTSP) was fabricated via nonsolvent-induced phase separation, with tea polyphenols, SiO2, and fibrous MXene synergistically incorporated. The resulting membrane exhibited a superhydrophilic/underwater oleophobic surface, with a water contact angle of 1° and an underwater oil contact angle of ~136°, owing to the optimized surface chemistry and hierarchical pore structure. As a result, the MTSP membrane effectively suppressed oil fouling while enabling rapid water transport. At 0.1 bar, the optimized membrane delivered an oil/water separation efficiency of ~99.5% and a high flux of 2420-2670 L·m-2·h-1, while maintaining >99% separation efficiency for various emulsified oils, including kerosene, edible oil, n-hexane, and 1,2-dichloroethane. It also showed excellent recyclability and chemical stability, retaining >98-99% efficiency after five cycles and after 24 h exposure to pH 1 and pH 12 conditions. Notably, for complex simulated wastewater containing emulsified kerosene, phenol, and Fe3+, Cu2+, Zn2+, and Cd2+, the membrane maintained ~99% oil/water separation efficiency and simultaneously removed ~79% of phenol and 70-86% of heavy metal ions in a single filtration process. The superior performance is attributed to the synergistic effects of the superhydrophilic/underwater-oleophobic membrane surface, hierarchical transport channels enabling rapid water permeation, and multifunctional sites that adsorb/coordinate dissolved pollutants. This work provides a simple, scalable design strategy for PVDF-based membranes that integrate high-flux separation, antifouling performance, and multi-pollutant remediation for the treatment of complex oily wastewater.
Riociguat, a vasodilatory drug for treating pulmonary hypertension (PH), might generate a nitrosamine drug substance-related impurity (NDSRI), reported as N-nitroso-desformyl riociguat (NNDFR). NDSRIs are a class of nitrosamine impurities that are specific to each drug and are structurally related to the active pharmaceutical ingredient (API) either or both sharing a common molecular backbone but differing by specific functional groups. Such impurities have drawn growing regulatory attention due to their recognized genotoxic and carcinogenic potential, in which the identification and quantification in the product is mandatory. Thus, a sensitive and reliable Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) method is developed employing a Shimpack-GIS CN column (150 mm × 4.6 mm × 3 µm) with a gradient of 0.1% formic acid in water, and 0.1% formic acid in methanol for chromatography separation, and in multiple reaction monitoring (MRM) mode in an electrospray ionization (ESI) environment. Optimized conditions focused on chromatographic selectivity, ionization efficiency, and matrix interference reduction. Method validation for the identification of NNDFR in the riociguat drug product confirmed that this method achieved baseline separation of NNDFR isomers with retention times of 10.037 (Isomer-1) and 10.579 (Isomer-2) minutes, prohibiting interferences from other compounds. Validation also confirmed excellent linearity (R2 > 0.99), precision (RSD < 1.3%), and accuracy (recoveries from 100.5% to 110.4%). The LOD and LOQ were determined to be 0.4 ppm and 1.22 ppm, respectively. A 24-hour stability study confirmed the analyte integrity and method robustness at various flow rates and column temperatures, and under various filtration conditions, ensuring consistent performance. This validated UHPLC-MS/MS method is robust, sensitive, and reliable for routinely quantifying NNDFR in riociguat drug products. Subsequently, the analytical method developed was assessed for environmental sustainability using established greenness assessment tools. The AGREE score was calculated to be 0.73, AGREEprep to be 0.69, and the BAGI value to be 70.0. These values reflected a favorable environmental profile, efficient sample preparation, and practical sustainability. Together, these metrics confirmed the method's suitability for both regulatory compliance and routine application in industrial quality control laboratories.
Aloe vera has long been used for its diverse pharmacological properties, motivating continued interest in isolating and preserving the bioactive molecules responsible for its therapeutic potential. More recently, Aloe vera-derived extracellular vesicles (Av-EVs) have emerged as nanoscale, cell-free carriers capable of retaining and delivering these properties, making them attractive for various biomaterials, nanomedicine, and regenerative medicine applications. Multiple techniques are available for extracellular vesicle isolation. These include ultracentrifugation, polymer-based precipitation, size-exclusion chromatography, immunoaffinity capture, ultrafiltration, density gradient separation, and emerging microfluidic platforms. Each method presents distinct trade-offs in purity, yield, scalability, and downstream compatibility. Despite this diversity, standardized workflows tailored to Av-EV isolation remain limited, and the influence of homogenization-induced shear forces and plant maturity on vesicle recovery and characterization has not been systematically addressed. Here, we present a reproducible protocol for isolating Av-EVs from Aloe vera gel employing two distinct homogenization strategies: manual, no-shear force (NB EVs), and blender-based shear-force homogenization (B EVs). The workflow covers gel preparation, serial centrifugation for debris removal, ultracentrifugation as the gold standard for vesicle enrichment, and final sterile filtration. This protocol enables consistent recovery of Av-EVs suitable for physicochemical characterization and functional analyses. It is simple and relies on commonly available laboratory equipment, facilitating broad adoption by ultracentrifugation users and offering adaptability to diverse research projects involving purified Aloe vera gel and Av-EVs, including studies focused on wound healing, fibrotic scarring, and regenerative processes, where coordinated antioxidant, anti-inflammatory, antimicrobial, immunomodulatory, and moisturizing responses are of interest. Key features • This protocol allows direct comparison of vesicle yield, size distribution, and protein content across extraction methods. • This protocol yields ~1.4-2.0 × 1010 particles/mL per mature leaf for a total of ~8 × 1012 particles per leaf. • This protocol yields ~1.2-2.8 × 1010 particles/mL per young leaf for a total of ~2.8 × 1012 per leaf. • EVs from mature Aloe leaves yield protein concentrations of ~160-447 μg/mL, corresponding to ~3,840-10,728 μg of protein per leaf.
Separators have evolved from passive polymeric barriers into multifunctional components that critically govern the performance, safety, and lifetime of liquid and quasi-solid lithium rechargeable batteries. This Review provides a comprehensive analysis of separator materials and architectures spanning commercial polyolefins and their ceramic coatings, high‑temperature polymers (PI, PEEK), nanofiber and bio‑derived membranes, and cross-linked gel/polymer-ceramic composites for quasi-solid systems. Design principles linking pore size, porosity, tortuosity, wettability, and Li+ transference to ionic conductivity and rate capability are systematically discussed, alongside mechanical and thermal requirements such as puncture resistance, dimensional stability, shutdown behavior, and flame retardance. We compare major fabrication routes-including dry and wet stretching, phase inversion, electrospinning, ceramic/oxide coating, UV/thermal crosslinking, and vacuum filtration/solution casting-and relate their process windows to separator microstructure, electrochemical performance, and scalability. Separator-electrolyte-anode interactions are analyzed with emphasis on dendrite suppression, flux homogenization, and interface stabilization in lithium‑metal and quasi‑solid cells. Finally, market and techno‑economic trends are summarized, highlighting the trade‑offs between advanced functionality and roll‑to‑roll manufacturability, as well as emerging directions toward intelligent (advanced) separators and PFAS‑free, recyclable architectures. This review outlines quantitative targets and design strategies needed to translate next‑generation separator concepts into safe, high‑energy, and commercially viable lithium battery technologies.
Aging of the lacrimal gland (LG) is associated with reduced tear secretion and chronic inflammation, contributing to dry eye disease. Age-related LG changes include immune cell infiltration, cellular damage, lipid accumulation in acinar cells, extracellular matrix deposition, and ductal dilation. Single-cell RNA sequencing (scRNA-seq) provides a powerful approach to profile cellular heterogeneity and transcriptional changes during aging; however, generating viable single-cell suspensions from aged LG tissue is technically challenging due to increased fibrosis, cellular fragility, and lipid accumulation. This study presents an optimized, reproducible protocol for the efficient dissociation of aged mouse LGs and the isolation of multiple cell types, suitable for downstream scRNA-seq analysis. Importantly, this protocol is also applicable to young lacrimal glands, conjunctiva, and other exocrine tissues. The workflow employs a stepwise enzymatic dissociation strategy using Collagenase IV, Dispase II, and DNase I for initial tissue digestion, followed by Accutase to dissociate remaining cell clusters and a final DNase I treatment to obtain a clean single-cell suspension. To minimize cell damage, all plasticware is pre-coated with PBS containing bovine serum albumin, and tissue processing is performed under controlled temperature and agitation conditions. Red blood cell lysis and sequential filtration through several strainers further enhance cell purity. Cell type-specific isolation is achieved using reporter mouse lines combined with fluorescence-activated cell sorting (FACS). Using Acta2GFP and PdgfraEGFP mice, we successfully isolated myoepithelial cells and fibroblasts, respectively, following immunostaining with an EpCAM antibody. FACS enabled the separation of the EpCAM⁺/αSMA⁺ myoepithelial population, while EGFP⁺ cells from PdgfraEGFPmice represented the fibroblast population. This protocol yields high-quality, viable single-cell suspensions from aged LGs and can be readily adapted to other fibrotic or aging exocrine tissues requiring gentle dissociation and targeted cell isolation.
Performing efficient plasma separation from whole blood, a vital sample matrix for diagnostics, in point-of-care settings remains challenging, particularly for sensitive assays that require larger volumes than can be obtained from a finger prick. Centrifugation, the gold standard for plasma separation, relies on bulky equipment and trained personnel, making it difficult to implement in decentralized settings. Current point-of-care (POC) plasma separation methods are limited to microliter blood volumes, which are insufficient for high-sensitivity clinical applications; these tools also require manual operation and yield limited plasma volumes. Here, we present PlasmaLIFT (Large-volume Immunodepletion and Filtration Tool), an automated and compact device that uniquely combines two plasma separation strategies-immunomagnetic red blood cell depletion that enables downstream filtration without clogging, and a dual membrane size-exclusion filtration recently developed that removes remaining cells-to enable rapid, efficient plasma separation from 5 mL of whole blood within 10 minutes. PlasmaLIFT removes over 99.9% of cellular components without needing significant dilution or causing hemolysis, achieves a high plasma recovery efficiency of 80% at physiological hematocrit levels, and produces plasma containing clinically relevant biomarkers-demonstrated here for proteins, metabolites, lipids, nucleic acids, and viruses-at levels comparable to those obtained with centrifugation. This scalable, automated, centrifuge-free approach facilitates high-volume plasma separation in decentralized settings, potentially expanding access to sensitive blood-based diagnostic testing; future work to reduce the cost of magnetic beads at scale will expand access even further to low-resource settings.
Background Hepatitis B virus (HBV) infection and hypertension (HTN) are major public health concerns worldwide. Both conditions independently contribute to hepatic, renal, and metabolic disturbances. However, the combined impact of HTN on biochemical abnormalities in chronic HBV patients remains insufficiently characterized. The objective of the present work was to assess the biochemical profile of patients with HTN and/or chronic HBV infection at Laquintinie Hospital in Douala, Cameroon, and to determine the impact of HTN and its severity on hepatic, renal, and metabolic markers in HBV carriers. Methodology A comparative cross-sectional design was carried out in the hepato-gastroenterology department of Laquintinie Hospital from December 2022 to January 2024, involving 401 individuals. Following detection of the hepatitis B surface antigen (HBsAg) and measurement of blood pressure, the participants were separated into four groups, including 92 hypertensive patients with HBV infection (HTN+/HBV+), 73 hypertensive patients without HBV (HTN+/HBV-), 96 normotensive HBV-infected patients (HTN-/HBV+), and 140 healthy controls (HTN-/HBV). Hepatic, renal, and cardiac biochemical markers were assayed using enzymatic and colorimetric methods from commercial kits and automated biochemical analyzers. Frequencies of biochemical abnormalities were compared across groups. Logistic regression analysis was performed to evaluate associations between HTN and biochemical abnormalities in HBV-positive and HBV-negative patients. The relationship between HTN grade and biochemical disturbances in HBV carriers was also examined. Results Patients with both HTN and HBV infection (HTN+/HBV+) exhibited the most pronounced biochemical alterations, including significantly elevated liver enzymes, bilirubin, cystatin C, albuminuria, triglycerides, LDL cholesterol, and fasting glucose, along with reduced glomerular filtration rate (GFR) and potassium levels (p < 0.01). The healthy group (HTN- / HBV-) showed the most favorable biochemical profiles. In HBV-positive patients, HTN was strongly and positively associated (odds ratio (OR) > 1; p < 0.01) with elevated alanine aminotransferase (ALT; OR = 12.00), aspartate aminotransferase (AST; OR = 41.94), total bilirubin (OR = 33.81), cystatin C (OR = 39.00), renal insufficiency (OR = 36.93), albuminuria (OR = 14.00), hypertriglyceridemia (OR = 7.36), and elevated LDL cholesterol (OR = 8.84). Similar renal and metabolic associations were observed in HBV-negative hypertensive patients, though liver-specific markers were less affected. Increasing HTN grade showed limited additional impact on most biochemical parameters, with significant differences observed only for total bilirubin, total cholesterol, and potassium (p < 0.05). Conclusions The coexistence of HTN and chronic HBV infection is associated with significant hepatic, renal, and metabolic disturbances. While the presence of HTN markedly exacerbates biochemical abnormalities in HBV patients, increasing HTN severity confers limited additional impact. Integrated management strategies targeting both blood pressure control and viral disease are essential to reduce organ-related complications in this high-risk population.
The purpose of this study was to evaluate the long-term intraocular pressure (IOP)-lowering efficacy, antifibrotic activity, and outflow patency of a hydroxyapatite-coated degradable magnesium (HA-Mg) glaucoma drainage implant in a chronic glaucoma rabbit model. Chronic glaucoma was induced by anterior chamber injection of a magnetic bead suspension, and glaucomatous damage was confirmed by retinal thinning and optic nerve injury. In a separate cohort, glaucomatous eyes were randomized to trabeculectomy (TL), sham surgery, or HA-Mg implantation (n = 6/group) and followed for 6 months. IOP and corneal diameter were monitored longitudinally, aqueous outflow was evaluated using intracameral trypan blue, and filtration tissues were examined histologically. Modeled eyes maintained IOP at approximately 30 millimeters of mercury (mm Hg) for 6 weeks, accompanied by retinal thinning and optic nerve damage. After treatment, IOP in the HA-Mg group decreased below 21 mm Hg and remained significantly lower than in the sham and TL groups, in which IOP remained elevated or rebounded. Only HA-Mg-implanted eyes showed recovery of corneal diameter to baseline at 6 months. Trypan blue testing demonstrated persistent subconjunctival drainage in the HA-Mg group, and histology revealed reduced fibroblast proliferation, decreased collagen deposition, and preservation of a clear filtration pathway. The degradable HA-Mg implant was well tolerated, provided sustained IOP reduction, and maintained outflow patency while attenuating postoperative fibrosis, supporting its potential for clinical translation in glaucoma filtration surgery. A biodegradable HA-Mg drainage implant that sustains outflow and limits fibrosis may offer a safer and more durable alternative to permanent subconjunctival drainage devices.
A novel stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the quantification of baicalein (5,6,7-trihydroxyflavone) in bulk drug and nanoliposomal formulations. Samples were pretreated via dilution with mobile phase, membrane filtration (0.22 µm), protection from light, and refrigerated storage prior to analysis. Method validation was performed in accordance with ICH Q2(R2) guidelines. Chromatographic separation was achieved on a BDS C18 column using an isocratic mobile phase comprising water (pH 3.0, adjusted with orthophosphoric acid) and acetonitrile (50 : 50, v/v) at a flow rate of 1.0 mL min-1 with DAD detector. The method exhibited excellent linearity (0.0078-1 µg mL-1; R 2 = 0.9998), accuracy (98.25-101.58%), and precision (%RSD < 2%). The limits of detection (LOD) and quantification (LOQ) were 0.0069 µg mL-1 and 0.0208 µg mL-1, respectively. Forced degradation under acidic, alkaline, oxidative, and thermal stress conditions confirmed the stability-indicating capability, with pronounced degradation under acidic conditions and high thermal stability. The method was successfully applied to solubility profiling and quantification in nanoliposomal systems, including entrapment efficiency and drug loading. Greenness assessment using Blue Applicability Grade Index (BAGI), Modified Green Analytical Procedure Index (MoGAPI), Carbon Footprint Reduction Index (CaFRI), Click Analytical Chemistry Index (CACI), Analytical GREEnness (AGREE), and Violet Innovation Grade Index (VIGI) yielded scores of 75, 85, 77, 80, 0.64, and 55, respectively. The method demonstrates key advantages, including buffer-free operation, reduced chemical hazard, and operational simplicity; however, moderate organic solvent usage imposes minor sustainability limitations. Overall, the method is robust, sensitive, and suitable for routine pharmaceutical and nanoformulation analysis.
Herein, a hydrolyzed polyacrylonitrile (PAN) nanofiber membrane with highly oriented structure (designated as HOFM) is fabricated for in situ dynamic fouling control during oil-in-water (O/W) emulsion separation. This membrane possesses piezoelectric properties, capable of inducing sustained negative charges and generating an open-circuit output voltage of 6 V under a pulsed pressure of 10 kPa. During filtration, the inherent pulsed hydraulic pressure is converted into pulsed voltage, thereby constructing a dynamic electric field. Both experimental results and molecular dynamics simulations verify that this dynamic electric field not only facilitates the deformation, collision, and coalescence of emulsified oil droplets to accelerate demulsification significantly but also mitigates the adsorption and deposition of negatively charged oil droplets on the membrane surface via electrostatic repulsion, thus effectively alleviating membrane fouling. Benefiting from this piezoelectric effect, the HOFM exhibits a stable permeation flux of approximately 4000 L m-2 h-1 bar-1 and maintains a separation efficiency exceeding 97% for SDS surfactant-stabilized O/W emulsions during long-term continuous separation, exhibiting application potential in wastewater treatment. This work combines the piezoelectric self-powered property with membrane separation technology, providing a strategy for efficient and eco-friendly oil-water separation.
Developing membranes with superior antifouling properties is crucial for efficient and sustainable water treatment. In this study, polysulfone (PSM) composite membranes were fabricated by incorporating hydroxylated titanium nanotubes (TNT@OH) via the non-solvent-induced phase separation method. The hydroxylation of TNTs enhanced their dispersion in the polymer matrix and promoted strong polymer-nanoparticle interactions. Comprehensive characterization using FTIR, XRD, TGA, FESEM, and AFM confirmed the successful integration of TNT@OH, resulting in membranes with improved hydrophilicity, porosity, and thermal stability. The contact angle decreased from ~88° for neat PSM to ~50° at 7 wt% TNT@OH, while surface free energy increased significantly. Mechanical strength and flexibility were also enhanced at optimal TNT@OH loadings (3-5 wt%), owing to uniform dispersion and strong interfacial bonding. Filtration experiments using humic acid (HA) and natural organic matter (NOM) demonstrated remarkable improvements in water flux, rejection efficiency, and fouling resistance. The composite membranes achieved HA rejection rates of up to 98%, with reduced irreversible fouling and higher flux recovery ratios across multiple filtration-cleaning cycles. The proposed antifouling mechanism is attributed to the formation of a stable hydration layer by surface hydroxyl groups, which prevents foulant adhesion and facilitates cleaning. These findings suggest that incorporating TNT@OH into polysulfone membranes is a promising approach for developing high-performance ultrafiltration membranes with enhanced permeability, mechanical robustness, and long-term antifouling stability, thereby making them suitable for advanced water purification applications.
The critical micelle concentration (CMC) is a core parameter dictating the formation and stability of polymeric micelles in drug delivery. Conventional CMC determination methods, relying on indirect measurements, are constrained by issues such as limited sensitivity or potential interference. To overcome these limitations, this study established a method based on ultrafiltration coupled with liquid chromatography-tandem mass spectrometry (UF-LC-MS/MS) for directly determining the CMC of methoxy poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PLA) with varying PLA chain lengths. The LC-MS/MS method exhibited good linearity, accuracy, and precision for the quantification of mPEG2000-PLA2000, mPEG2000-PLA3000, and mPEG2000-PLA5000. The optimized and validated ultrafiltration process ensured selective separation of micelles from unimers. By identifying the inflection point in the concentration of free mPEG-PLA in the tested sample, the CMC values were determined as 5.77 ± 0.16 μg/mL for mPEG2000-PLA2000, 3.02 ± 0.16 μg/mL for mPEG2000-PLA3000, and 1.86 ± 0.04 μg/mL for mPEG2000-PLA5000. These results were comparable to those from the conventional pyrene fluorescence probe assay, demonstrating that UF-LC-MS/MS is a robust tool for CMC determination of mPEG-PLA copolymers, with strong potential for broader application to other amphiphilic polymers.
The ability to adjust the size, composition, optical behavior and physicochemical properties of quantum dots (QDs) makes them a promising material for use in analysis, photocatalysis, biochemistry, solar cells, and display technologies. However, obtaining monodisperse QDs with uniform properties remains a challenging task. Their optical characteristics are highly sensitive to size and structural homogeneity, which directly dictate the photoluminescence quantum yield, emission wavelength and spectral bandwidth. Although a lot of research is aimed at optimizing synthesis in order to achieve QDs with a narrow size distribution, post synthetic, non-destructive size separation of QDs remains a crucial area of study. This review categorizes various QD size-separation methods, highlighting size-selective precipitation and membrane filtration as the most established techniques, while also evaluating the pros and cons of density gradient ultracentrifugation, along with various forms of electrophoresis and chromatography. By selecting an accessible, reproducible, and effective separation method tailored to a specific QD system and application, researchers can isolate monodisperse QDs of defined sizes rather than relying on heterogeneous mixtures-an outcome that is highly beneficial for both fundamental research and practical applications.
Observational studies link high net ultrafiltration (UFNET) rates during continuous kidney replacement therapy (CKRT) to increased mortality. The Restrictive versus Liberal Rate of Extracorporeal Volume Evaluation in Acute Kidney Injury trial evaluated the feasibility of a restrictive versus liberal UFNET rate strategy. This stepped-wedge cluster-randomized trial enrolled patients in ten ICUs across two healthcare systems from July 2022 to June 2024. Each ICU was a cluster, with 1 randomly transitioning from liberal (2.0-5.0 mL/kg/h) to restrictive (0.5-1.5 mL/kg/h) group every two months after the first six months. The coprimary outcomes included between-group separation in UFNET rates, protocol adherence, and recruitment rate. Of 97 patients (55 liberal, 42 restrictive) enrolled, the mean (SD) delivered UFNET rate did not differ between the groups (2.05 [0.83] vs. 1.81 [0.86] mL/kg/h; adjusted P = 0.4). In per-protocol analysis, there was a significant between-group separation in mean UFNET rates (2.24 [0.72] vs. 1.22 [0.32] mL/kg/h; P = 0.002). Protocol deviations were similar (9.1% vs.7.1%, P = 0.7), and the recruitment rate was 0.99 (0.27) patients per ICU per two months. The use of rescue UFNET was higher in the restrictive group (14.5% vs. 66.7%; P < 0.001). In conclusion, despite high protocol adherence, there was minimal separation in delivered UFNET rates. While both strategies were feasible in select patients, the high rates of hemodynamic instability, the need for rescue UFNET, and physician override orders suggest that UFNET is more often driven by dynamic patient physiology than fixed protocols. This makes it challenging to maintain distinct, alternative UFNET targets in clinical practice.Trial registration number: ClinicalTrials.gov Identifier: NCT05306964.
Polyvinylidene fluoride (PVDF) membranes are used in ultrafiltration systems for car wash water reuse, where frequent alkaline cleaning is required to maintain operational flux rates. Although NaOH-induced degradation of virgin PVDF membranes has been reported, its relevance under real industrial conditions remains poorly understood. This study investigates the long-term exposure of tubular PVDF membranes to alkaline car wash detergents and evaluates how the resulting structural changes influence permeate quality. During several months of pilot-scale operation with synthetic car wash wastewater and daily alkaline cleaning (pH > 11.5), permeate fluxes remained stable at 50-70 LMH despite pronounced membrane aging. Structural analyses revealed enlarged pore size, increased water permeability and reduced dextran retention, while FTIR confirmed dehydrofluorination of the polymer matrix. Despite the extensive degradation of the membrane skin layer, permeate turbidity, dissolved organic carbon, and surfactant concentrations remained stable throughout the operation. This stability was attributed to the persistent fouling layer, which acted as an effective secondary separation barrier and compensated for the loss of intrinsic membrane selectivity. These findings demonstrate that substantial PVDF degradation does not necessarily compromise permeate quality in car wash ultrafiltration systems, highlighting the dominant role of fouling-controlled separation under long-term alkaline cleaning regimes.
Aseptic osteolysis induced by ultra-high-molecular-weight polyethylene (UHMWPE) wear debris has historically been a major cause of late failure in total hip arthroplasty, highlighting the need for more robust methods to isolate and identify wear particles in complex biological matrices. To validate an optimized protocol for the isolation and identification of UHMWPE wear debris from hip simulator lubricant serum by combining lyophilization, alkaline digestion, and chemometric analysis based on principal component analysis (PCA) applied to energy-dispersive x-ray spectroscopy (EDS) data. Wear tests were performed in a hip simulator in accordance with ABNT NBR ISO 14242-1, using metal-on-UHMWPE and ceramic-on-UHMWPE bearing couples lubricated with 25% fetal bovine serum. Three isolation procedures were compared: direct liquid digestion and two protocols based on lyophilization followed by alkaline digestion with 6 mol/L KOH. Particles retained on polyethersulfone (PES) membranes were characterized by scanning electron microscopy (SEM; ASTM F1877) and EDS. Weight percentages of C, O, Na, K, Ca, Cl, S, and Au were subjected to PCA after autoscaling. Lyophilization increased filtration efficiency from 17% (0.2 g) to 25% (~4 g) and markedly reduced sample storage volume. SEM micrographs revealed typical fibrillar and globular UHMWPE particles ranging from 0.1 to 20 μm. PCA explained 67.4% of the total variance in the first three components and generated a distinct cluster of carbon-rich regions, clearly separated from areas dominated by salts and membrane background. The combination of lyophilization, alkaline digestion, and PCA-assisted EDS analysis improves recovery efficiency, preserves particle morphology, and supports the discrimination of UHMWPE wear debris in complex serum matrices, providing a practical and transferable approach for preclinical wear testing.
Sickle cell nephropathy is a common complication of sickle cell disease that begins in childhood and can progress silently to chronic kidney disease. In the Democratic Republic of Congo (DRC), data on early kidney damage in children with sickle cell disease remain limited. In 2017, studies conducted in the same context reported separately on the prevalence of microalbuminuria and glomerular hyperfiltration (GHF). This study aimed to update the prevalence of albuminuria and GHF and to determine their associated factors in children with sickle cell disease in the DRC. We conducted a cross-sectional study including 175 children with sickle cell disease, followed up in four hospitals in Kinshasa. High albuminuria and GHF, the main evaluation criteria, were defined respectively by an albuminuria/creatinine ratio (ACR) ≥ 30 mg/g and an estimated glomerular filtration rate (eGFR) > 130 ml/min/1.73 m2 in girls and > 140 ml/min/1.73 m2 in boys, according to the Schwartz formula. Among the 175 children included, 28.5% had high albuminuria and 38.3% had GHF. Factors significantly associated with early renal involvement were frequent blood transfusions (≥ 9/year), recurrent vaso-occlusive crises (≥ 3/year), low fetal hemoglobin levels (< 15%), and markers of hemolysis (LDH > 400 IU/L and elevated indirect bilirubin). These results reflect a high persistence of early renal impairment nearly nine years after the first data were published. Early markers of kidney damage remain very common in children with homozygous sickle cell disease in the DRC. This persistence highlights the lack of effective kidney prevention strategies and the urgent need for systematic screening using simple and accessible tools in resource-limited settings.
The stability of amino acids, vitamins, and trace elements in parenteral nutrition (PN) admixtures is a critical factor in ensuring the safety, efficacy, and quality of intravenous nutritional support. This review analyzes the main degradation and instability mechanisms affecting these essential components, including the photooxidation of sensitive amino acids, Maillard reactions, the loss of water-soluble vitamins due to oxidation or interactions with trace elements, and the precipitation of micronutrients resulting from physicochemical incompatibilities. Key contributing factors such as pH, temperature, oxygen exposure, ultraviolet light, and packaging materials are described. The article integrates recent evidence and consensus recommendations, proposing practical strategies such as the use of multilayer bags, light protection, oxygen limitation, optimal sequence of component addition, physical separation of unstable compounds, and the use of in-line filtration during administration. These precautions are particularly important in vulnerable populations such as neonates or patients receiving long-term home PN. This consensus document aims to provide technical and clinical criteria to improve the safety and stability of nutrients administered parenterally, adapting their preparation and handling to real-world conditions in both hospital and home care settings.