Evaluation of an Automated Ultrafiltration System for Concentrating a Range of Viruses from Saline Waters.

Pathogenic viruses in environmental water are usually present in levels too low for direct detection and thus, a concentration step is often required to increase the analytical sensitivity. The objective of this study was to evaluate an automated filtration device, the Innovaprep Concentrating Pipette Select (CP Select) for the rapid concentration of viruses in saline water samples, while considering duration of process and ease of use. Four bacteriophages (MS2, P22, Phi6, and PhiX174) and three animal viruses (adenovirus, coronavirus OC43, and canine distemper virus) were seeded in artificial seawater, aquarium water, and bay water samples, and processed using the CP Select. The recovery efficiencies of viruses were determined either using a plaque assay or droplet digital PCR (ddPCR). Using plaque assays, the average recovery efficiencies for bacteriophages ranged from 4.84 ± 3.8% to 82.73 ± 27.3%, with highest recovery for P22 phage. The average recovery efficiencies for the CP Select were 39.31 ± 26.6% for adenovirus, 19.04 ± 11.6% for coronavirus OC43, and 19.84 ± 13.6% for canine distemper virus, as determined by ddPCR. Overall, viral genome composition, not the size of the virus, affected the recovery efficiencies for the CP Select. The small sample volume size used for the ultrafilter pipette of the system hinders the use of this method as a primary concentration step for viruses in marine waters. However, the ease of use and rapid processing time of the CP Select are especially beneficial when rapid detection of viruses in highly contaminated water, such as wastewater or sewage-polluted surface water, is needed.

Evaluación clínica y económica del uso de ultrafiltración en pacientes con insuficiencia cardíaca aguda / Clinical and economic evaluation of the use of ultrafiltration in patients with acute heart failure

ANTECEDENTES: La ICA es la mayor causa de hospitalizaciones en personas de ≥65 años, y está asociada a una tasa de mortalidad y reingreso elevada. La ICA se puede presentar como una primera manifestación de la IC (de novo) o, más frecuentemente, como consecuencia de una descompensación aguda de la IC crónica. Los diuréticos son la base del tratamiento de la ICA con sobrecarga de volumen y congestión. Los más utilizados son los diuréticos de asa. En ciertos pacientes, puede existir una resistencia a estos fármacos, por lo que, para resolver la congestión, se ha empleado la ultrafiltración. La ultrafiltración se refiere a la eliminación mecánica y ajustable de agua plasmática isotónica de la sangre a través de una membrana semipermeable (hemofiltro), mediada por la aplicación de un gradiente de presión hidrostática generado por una bomba. OBJETIVO: Evaluar la eficacia, seguridad y costo-efectividad del uso de ultrafiltración en pacientes con insuficiencia cardiaca aguda. MÉTODOS: Se realizó una búsqueda sistemática y exhaustiva de toda la evidencia disponible en Pubmed, BVS y Cochrane library, obteniendo una revisión sistemática con metaanálisis de confianza alta, de acuerdo a AMSTAR-2, la cual fue utilizada para el análisis cualitativo. RESULTADOS: Se identificaron un total de 780 estudios, de los cuales, 59 estudios fueron revisados a texto completo, obteniendo 4 revisiones sistemáticas, en donde, 3 no cumplieron con criterios de calidad metodológica, consiguiendo una confianza críticamente baja. La revisión sistemática incluida en nuestro análisis, demostró un efecto estadístico nulo en todos los desenlaces evaluados (mortalidad, rehospitalización, mejoría clínica, efectos adversos), a excepción de la rehospitalización por insuficiencia cardiaca a largo plazo, donde el efecto favoreció a la intervención de análisis (ultrafiltración). CONCLUSIÓN: De los datos obtenidos de la evaluación clínica, se identifica que la UF podría reducir la rehospitalización por insuficiencia cardiaca, la cual, es la causa de los mayores gastos por insuficiencia cardiaca aguda en los sistemas de salud. Debido a la certeza limitada de los hallazgos, se debe mantener en vigilancia estrecha a las nuevas publicaciones del tema, para confirmar o modificar la dirección del efecto de los distintos desenlaces.

Probing protein rejection behavior of blended PES-based flat-sheet ultrafiltration membranes: A density functional theory (DFT) study.

Membrane fouling is a common problem in membrane technology and causes detrimental effects for the applied membranes such as loss of integrity and productivity. Henceforward, we devoted this work to fabricate membranes that pose favored criteria in the direction of alleviating membrane fouling incidence. Herein, the fabricated membranes were traced via an assortment of both experimental and molecular modeling verifications to understand the mechanism of interaction. To do so, firstly, three different ultrafiltration (UF) membranes had been prepared via facile wet phase inversion method thru dipping a casting solution composed of polyethersulfone-polyvinyl pyrrolidone (PES-PVP) and polyethersulfone-Pluronic P31R1 (PES-P31R1) in a water coagulation bath. Regarding the practical-based data, the pristine PES membrane exhibited the highest rejection of bovine serum albumin (BSA) protein (model foulant) compared with the modified PES-based membranes. The membrane chemical compositions were elucidated with ATR-FTIR Spectroscopy. On the other hand, molecular modeling has been carried out via calculating thermodynamic parameters, level parametric method, and density functional theory (DFT). Thermodynamic parameters analysis indicated that the noticeable difference of BSA rejection may be ascribed to different entropy behavior for the fabricated membranes. In addition, the level parametric method (PM6) and density functional theory DFT: B3LYP with 6-31g (d,p) basis set models clarified the interaction manner of BSA molecules to membrane surfaces.

Filter-Membrane-Based Ultrafiltration Coupled with Surface-Enhanced Raman Spectroscopy for Potential Differentiation of Benign and Malignant Thyroid Tumors from Blood Plasma.

OBJECTIVE: The objective of this study is to evaluate the performance and feasibility of surface-enhanced Raman spectroscopy coupled with a filter membrane and advanced multivariate data analysis on identifying and differentiating benign and malignant thyroid tumors from blood plasma. PATIENTS AND METHODS: We proposed a membrane filter SERS technology for the differentiation between benign thyroid tumor and thyroid cancer. That is to say, by using filter membranes with optimal pore size, the blood plasma samples from thyroid tumor patients were pretreated with the macromolecular proteins being filtered out prior to SERS measurement. The SERS spectra of blood plasma ultrafiltrate obtained using filter membranes from 102 patients with thyroid tumors (70 thyroid cancers and 32 benign thyroid tumors) were then analyzed and compared. Two multivariate statistical analyses, principal component analysis-linear discriminate analysis (PCA-LDA) and Lasso-partial least squares-discriminant analysis (Lasso-PLS-DA), were performed on the SERS spectral data after background subtraction and normalization, as well as the first derivative processing, to analyze and compare the differential diagnosis of benign thyroid tumors and thyroid cancer. RESULTS: SERS measurements were performed in blood plasma acquired from a total of 102 thyroid tumor patients (benign thyroid tumor N=32; thyroid cancer N=70). By using filter membranes, the macromolecular proteins in blood plasma were effectively filtered out to yield high-quality SERS spectra. 84.3% discrimination accuracy between benign and malignant thyroid tumor was achieved using PCA-LDA method, while Lasso-PLS-DA yields a discrimination accuracy of 90.2%. CONCLUSION: Our results demonstrate that SERS spectroscopy, coupled with ultrafiltration and multivariate analysis has the potential of providing a non-invasive, rapid, and objective detection and differentiation of benign and malignant thyroid tumors.

Fabrication of nanofiltration membrane based on non-biofouling PVP/lecithin nanofibers reinforced with microcrystalline cellulose via needle and needle-less electrospinning techniques.

In this work, polyvinylpyrrolidone nanofibers were electrospun incorporated with lecithin, zero-charge natural segment, as non-biofouling nanofiltration membrane with tunable porous structures. Optimum conditions were studied to obtain nano-pore size capable of nano-scaled objects reduction using needle and needleless electrospinning apparatuses. Fiber diameters were in proportional relationship with PVP concentrations to range from 1.2 um to 34 nm at 10 to 5% wt/v PVP respectively. Microcrystalline cellulose (MCC) was added and PVP fibers were photo-crosslinked to enhance the mechanical strength. Mechanical properties of electrospun fibers were enforced up to 279% in the presence of microcrystalline cellulose while increased by 125% when exposed to photo-crosslinking for 8 h by UV-light radiation. UV-crosslinking has significantly improved the hydrophobicity of the final mat to report contact angle bigger than 90° at 16 h. Protein adhesion test was conducted to indicate the capability of the electrospun membrane to bypass the blood-plasma products. Zero protein adhesion was recorded by adding only 2% wt/v of lecithin.

Economic model for obtaining cyclodextrins from commercial cgtase

A repetitive batch process was employed followed by membrane ultrafiltration system to produce low-cost cyclodextrins (CDs) using commercial enzymes Toruzyme® cyclomaltodextrin glucanotransferase (CGTase) and its kinetic parameters were determined. The ultrafiltration system enabled the removalof inhibitory products from the reaction medium, allowing the enzyme to be recovered for reuse. A 10 kDa membrane was used to separate the different CDs produced by the CGTase. The substrates evaluated were maltodextrin, corn starch and cassava starch at 5, 10 and 15% (w/V), in the presence and absence of 10% (V/V) ethanol. After reaction for 132 h, 10% (w/V) cassava starch in the presence of ethanol provided the best results with 32.1 mg/mL of ß-CD. Maximum production occurred after 72 h of reaction, with a yield of 87.4% of ß-CD and an α-CD, ß-CD and γ-CD production ratio of 1:1:0.08 g, respectively. When eight repetitive batches of 72 h followed by ultrafiltration and crystallization of ß-CD were performed, 2.1 g of precipitate was obtained with a purity of 67.6% ß-CD. The supernatant from the crystallization process was lyophilized and resulted in 35.3% α-CD. The developed model can be used industrially for the production of low cost CDs from easily obtained raw material

Molecular traits of phenolic moieties in dissolved organic matter: Linkages with membrane fouling development.

Phenolic moieties are important constituents in dissolved organic matter (DOM) in natural and engineered systems. However, their roles in membrane fouling mechanism during drinking water treatment by ultrafiltration (UF) have remained elusive. Herein, by using water insoluble polyvinylpolypyrrolidone (PVPP) resins, we sequestered the phenolic moieties from a model DOM (Suwannee River DOM, SRDOM) and characterized their molecular profiles using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). Subsequently, their roles in UF membrane fouling propensity were investigated using reconstituted DOM solutions with various concentrations of phenolic moieties. The results showed that the phenolic moieties were of higher molecular weight and rich in unsaturation cyclic structures and oxygen-rich groups. Van Krevelen diagrams revealed that the sequestered sample was rich in aromatics structures and tannins-like compounds while contained less alicyclic organic acids in comparison with the original SRDOM, which was consistent with the aromaticity index (AI) analysis. UF experiments showed that the more phenolic moieties in DOM solution, the severer decline of flux was observed. The phenolic moieties played a significant role in membrane irremovable fouling due to the hydrophobic interactions and their higher molecular weight as evidenced by membrane cleaning tests. By surface characterization, the SRDOM fouled membrane was identified to have a higher water contact angle value and abundant C-O groups, likely due to the adsorption of more hydrophobic phenolic moieties. Overall, these findings highlighted links between phenolic moieties and membrane fouling development, and implied that membrane performance could be improved by pre-removal of phenolic moieties in DOM.

Role of concentration polarization in cross flow micellar enhanced ultrafiltration of cadmium with low surfactant concentration.

Concentration polarization is an important issue in micellar enhanced ultrafiltration (MEUF) of wastewater containing heavy metal ions at low surfactant concentrations. In this paper, we studied removal of Cd(Ⅱ) by cross flow MEUF at low sodium dodecyl sulfate (SDS) concentration levels, and the role of concentration polarization in flux decline and Cd(Ⅱ) rejection was emphasized. Concentration polarization resistance and SDS concentration near membrane were calculated to characterize concentration polarization. The results showed that SDS concentration near membrane was 13 mM when feed concentration was merely 0.8 mM. By combining phase diagram of SDS, structures of SDS micelles in concentration polarization layer were deduced and thin layer structure transformed to porous structure formed by accumulated globular micelles when SDS concentration increased. Although micelles formed in concentration polarization layer was responsible for flux decline, they also provided adsorption sites for Cd(Ⅱ).

Smart ultrafiltration membrane fouling control as desalination pretreatment of shale gas fracturing wastewater: The effects of backwash water.

BACKGROUND: Increasing attention is being paid to the treatment of shale gas fracturing wastewater, including flowback and produced water (FPW). Energy-efficient pretreatment technologies suitable for desalinating and reusing FPW are of paramount importance. OBJECTIVES: This work focused on enhanced fouling alleviation of ultrafiltration (UF) as a pretreatment for desalinating shale gas FPW in Sichuan Basin, China. The UF fouling behaviors under various backwash water sources or coagulant dosages were evaluated, and membrane surface characteristics were correlated with UF fouling. The feasibility of Fourier transform infrared (FTIR) microscope mapping technique in quantifying UF fouling was also assessed. METHODS: Various backwash water sources, including UF permeate, ultrapure water, nanofiltration (NF) permeate, reverse osmosis (RO) permeate, RO concentrate and forward osmosis (FO) draw solution, were used to clean UF membranes fouled by shale gas FPW. The UF fouling behaviors were characterized by total and non-backwashable fouling rates. Membrane surface characteristics were analyzed by scanning electron microscopy (SEM), total tension surface and FTIR spectra. RESULTS: Protein-like substances in terms of fluorescence intensity in the backwash water decreased with the order of UF permeate, RO concentrate, NF permeate, RO permeate and FO draw solution. Compared with UF permeate backwashing, alleviated UF fouling was observed by using demineralized backwash water including ultrapure water and RO permeate, irrespective of hollow fiber and flat-sheet membranes. NF permeate and RO concentrate after NF used as backwash water resulted in low and comparable membrane fouling with that in integrated coagulation-UF process under optimal dosage. Among the backwash water tested, FO draw solution backwashing corresponded to the lowest UF fouling rates, which were even lower than that in the presence of coagulant under optimal dosage. The superiority of these backwash water sources to UF permeate was further confirmed by SEM images and FTIR spectra. The residual foulant mass on membrane surface and the total surface tension correlated well with non-backwashable and total fouling rates, respectively. CONCLUSIONS: FTIR microscopy was a powerful surface mapping technique to characterize UF membrane fouling caused by shale gas FPW. Backwash water sources significantly influenced the fouling of UF membranes. In the integrated UF-NF-RO or UF-FO process, RO concentrate or FO draw solution were proposed as backwash water to enhance UF fouling control and decrease waste discharge simultaneously.

Rapid identification of urokinase plasminogen activator inhibitors from Traditional Chinese Medicines based on ultrafiltration, LC-MS and in silico docking.

The urokinase plasminogen activator (uPA) is regarded as the crucial trigger for plasmin generation, which is involved in several diseases especially for neoplasm metastasis. In this study, an efficient approach integrating ultrafiltration, LC/MS, bioassay and in silico docking, was proposed for rapidly detecting uPA ligands from Traditional Chinese Medicines (TCMs). Forty-two TCMs were initially assessed, and as illustrative case studies, Galla Chinensis and Sanguisorbae Radix, which appeared significant inhibitory activities on uPA, were chosen to develpe and verify the strategy. A total of seven uPA ligands were successfully detected and identified. Two of them, pentagalloylglucose and 28-O-ß-d-glucopyranosyl pomolic acid, were demonstrated to be potential inhibitors, with IC50 at 1.639 µM and 37.82 µM repectively. Furthermore, a combinatorial compound library screening combined with in silico docking assay, was revealed that ursolic acid (IC50 = 2.623 µM) was also speculated to be a potent parent structure for inhibition of uPA. This approach offers a multidimensional perspective to discover uPA-binding leading compounds from TCMs or other complex mixtures, which would provide an efficient route for drug discovery.

Antifouling Ultrafiltration Membranes with Retained Pore Size by Controlled Deposition of Zwitterionic Polymers and Poly(ethylene glycol).

We demonstrate antifouling ultrafiltration membranes with retained selectivity and pure water flux through the controlled deposition of zwitterionic polymers and poly(ethylene glycol) (PEG). Molecules for polymerization were immobilized on the membrane's surface yet prevented from attaching to the membrane's pores due to a backflow of nitrogen (N2) gas achieved using an in-house constructed apparatus that we named the polymer prevention apparatus, or "PolyPrev". First, the operating parameters of the PolyPrev were optimized by investigating the polymerization of dopamine, which was selected due to its versatility in enabling further chemical reactions, published metrics for comparison, and its oxidative self-polymerization. Membrane characterization revealed that the polydopamine-modified membranes exhibited enhanced hydrophilicity; moreover, their size selectivity and pure water flux were statistically the same as those of the unmodified membranes. Because it is well documented that polydopamine coatings do not provide a long-lasting antifouling activity, poly(2-methacryloyloxyethyl phosphorylcholine) (polyMPC, Mn = 30 kDa) and succinimidyl-carboxymethyl-ester-terminated PEG ( Mn = 40 kDa) were codeposited while dopamine was polymerizing to generate antifouling membranes. Statistically, the molecular-weight cutoff of the polyMPC- and PEG-functionalized membranes synthesized in the PolyPrev was equivalent to that of the unmodified membranes, and the pure water flux of the PEG membranes was equivalent to that of the unmodified membranes. Notably, membranes prepared in the PolyPrev with polyMPC and PEG decreased bovine serum albumin fouling and Escherichia coli attachment. This study demonstrates that by restricting antifouling chemistries from attaching within the pores of membranes, we can generate high-performance, antifouling membranes appropriate for a wide range of water treatment applications without compromising intrinsic transport properties.

Efficient removal of nickel(II) from high salinity wastewater by a novel PAA/ZIF-8/PVDF hybrid ultrafiltration membrane.

Enhanced removal of trace toxic metals (ppm level) from high-salinity wastewater is crucial to ensure water safety but still a challenging task. In this study, we fabricated a new hybrid ultrafiltration membrane (PAA/ZIF-8/PVDF) by immobilizing zeolitic imidazolate framework-8 (ZIF-8) particles onto the surface of trimesoyl chloride (TMC)-modified polyvinylidene fluoride (PVDF) membrane under protection of polyacrylic acid (PAA) layer. The resultant PAA/ZIF-8/PVDF membrane exhibited relatively high water flux of 460 L·m-2 h-1 and outstanding nickel ion (Ni(II)) capacity (219.09 mg/g) from a synthetic high-salinity ([Na+] = 15000 mg/L) wastewater. X-ray photoelectron spectroscopic studies revealed that preferable Ni(II) uptake was mainly attributed to the specific interaction between Ni(II) and hydroxyl groups on ZIF-8 frameworks and carboxyl groups in PAA layer as well. Compared to PAA, ZIF-8 could selectively bind Ni(II) with negligible effect exerted by concentrated sodium ion. The filtration study showed that the 12.56-cm2 membrane could effectively treat 5.76 L high-salinity wastewater ([Ni(II)0 = 2 mg/L, [Na+]0 = 15000 mg/L) to conspicuously reduce Ni(II) below the maximum contaminant level of China, 0.1 mg/L. Moreover, the hybrid membrane could be regenerated by HCl-NaCl solution (pH = 5.5) for repeated use under direct current electric field. Generally speaking, the newly developed ZIF-8 hybrid ultrafiltration membrane showed a very promising potential in enhanced removal of toxic metals from high-salinity wastewater treatment.

The role of salinity on the changes of the biomass characteristics and on the performance of an OMBR treating tannery wastewater.

Tannery wastewaters are difficult to treat biologically due to the high salinity and organic matter concentration. Conventional treatments, like sequential batch reactors (SBR) and membrane bioreactors (MBR), have showed settling problems, in the case of SBR, and ultrafiltration (UF) membrane fouling in the case of MBR, slowing their industrial application. In this work, the treatment of tannery wastewater with an osmotic membrane bioreactor (OMBR) is assessed. Forward osmosis (FO) membranes are characterized by a much lower fouling degree than UF membranes. The permeate passes through the membrane pores (practically only water by the high membrane rejection) from the feed solution to the draw solution, which is also an industrial wastewater (ammonia absorption effluent) in this work. Experiments were carried out at laboratory scale with a FO CTA-NW membrane from Hydration Technology Innovations (HTI). Tannery wastewater was treated by means of an OMBR using as DS an actual industrial wastewater mainly consisting of ammonium sulphate. The monitoring of the biological process was carried out with biological indicators like microbial hydrolytic enzymatic activities, dissolved and total adenosine triphosphate (ATP) in the mixed liquor and microbial population. Results indicated a limiting conductivity in the reactor of 35 mS cm-1 (on the 43th operation day), from which process was deteriorated. This process performance diminution was associated by a high decrease of the dehydrogenase activity and a sudden increase of the protease and lipase activities. The increase of the bacterial stress index also described appropriately the process performance. Regarding the relative abundance of bacterial phylotypes, 37 phyla were identified in the biomass. Proteobacteria were the most abundant (varying the relative abundance between 50.29% and 34.78%) during the first 34 days of operation. From this day on, Bacteroidetes were detected in a greater extent varying the relative abundance of this phylum between 27.20% and 40.45%.

Characterization and Separation of Cancer Cells with a Wicking Fiber Device.

Current cancer diagnostic methods lack the ability to quickly, simply, efficiently, and inexpensively screen cancer cells from a mixed population of cancer and normal cells. Methods based on biomarkers are unreliable due to complexity of cancer cells, plasticity of markers, and lack of common tumorigenic markers. Diagnostics are time intensive, require multiple tests, and provide limited information. In this study, we developed a novel wicking fiber device that separates cancer and normal cell types. To the best of our knowledge, no previous work has used vertical wicking of cells through fibers to identify and isolate cancer cells. The device separated mouse mammary tumor cells from a cellular mixture containing normal mouse mammary cells. Further investigation showed the device separated and isolated human cancer cells from a heterogeneous mixture of normal and cancerous human cells. We report a simple, inexpensive, and rapid technique that has potential to identify and isolate cancer cells from large volumes of liquid samples that can be translated to on-site clinic diagnosis.

Purification of Drug Loaded PLGA Nanoparticles Prepared by Emulsification Solvent Evaporation Using Stirred Cell Ultrafiltration Technique.

PURPOSE: The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. METHODS: The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter. The purification efficiency of this technique was compared with the conventional centrifugation technique. RESULTS: The flow rate of ultrafiltration was optimized for removal of surfactant (polyvinyl alcohol) impurities to the acceptable levels in 1-3.5 h from the nanoparticle dispersion of tamoxifen prepared by emulsification solvent evaporation method. CONCLUSIONS: The present investigations demonstrate the application of solvent resistant stirred cell ultrafiltration technique for removal of toxic impurities of surfactant (PVA) from the polymeric drug nanoparticles (tamoxifen) prepared by emulsification solvent evaporation method. This technique offers added benefit of producing more concentrated nanoparticles dispersion without causing significant particle size growth which is observed in other purification techniques, e.g., centrifugation and ultracentrifugation.

Extraction and isolation of potential anti-stroke compounds from flowers of Pueraria lobata guided by in vitro PC12 cell model.

A simple and efficient method based on ultrafiltration liquid chromatography-mass spectrometry (UFLC-MS) was applied to rapidly screen and identify ligands for lactate dehydrogenase (LDH) from the flowers of Pueraria lobata, and the compounds were assessed for anti-stroke activity using a PC12 cell model. Seven major isoflavones, kakkalide, 3'-hydroxy puerarin, puerarin, puerarin xyloside, tectoridin, tectorigenin, and ononin, were identified as potent LDH inhibitors. A continuous online method, which consisted of microwave-assisted extraction and countercurrent chromatography (MAE-CCC), was newly developed for scaled-up production of these compounds with high purity and efficiency. This novel approach, using UFLC-MS coupled with MAE-CCC and a PC12 cell model, provided a powerful tool for screening, extraction, and separation of LDH inhibitors from complex samples, and a useful platform for the large-scale production of functional food and nutraceutical ingredients.

Retrospective analysis of eliminating modified ultrafiltration after pediatric cardiopulmonary bypass.

Modified ultrafiltration (MUF) is a technique which is commonly used immediately post-cardiopulmonary bypass (CPB) for open heart surgery in children. There are many advantages of MUF, but there are also a number of less reported disadvantages. At our institution, after considering all of the available data, a decision was made to no longer perform MUF. The primary motivation being the simplified and miniaturized CPB circuit would reduce hemodilution, decrease our likelihood of reaching our transfusion trigger during CPB and, potentially, improve safety. This study reports the before and after data from this practice change. A total of 160 patients less than 8kg were studied over 38 months and divided into neonatal and pediatric cohorts. Parameters reported in this study include: demographics, hematocrit, blood product transfusion, hemostasis, hemodynamics and outcomes. Although retrospective, our analysis supports an advantage of preventing hemodilution (via circuit miniaturization) versus reversing hemodilution (via MUF) at our institution with the patient population we examined.

A Novel Centrifugation Method Using a Cell Salvage Device Offers an Alternative to the Use of Leukocyte-Depleting Filters for Autologous Blood Transfusions.

Autotransfusion protocols often use the use of costly filters, such as leukocyte-depleting filters (LDFs), to minimize reinfusion of activated leukocytes and inflammatory mediators associated with reperfusion injury (RI). LDFs are used extensively in hospital settings; however, they represent an additional capital expenditure for hospitals, as well as a constraint on the reinfusion rate of blood products for health-care providers. We compared a commonly used LDF to a novel centrifugation method employing a widely used cell salvage device. Complete blood counts and enzyme-linked immunosorbent assays (ELISAs) measuring tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) were performed to compare the efficacy of these methodologies. The LDF removed, on average, 94% of all leukocytes, including 96% of neutrophils. The centrifugation method removed, on average, 89% of all leukocytes, including 91% of neutrophils and resulted in a highly concentrated red blood cell product. Our results suggest both methods offer equivalent leukocyte reduction. TNF-α was also comparably reduced following our novel centrifugation method and the LDF method and IL-2 levels were undetectable in all samples. These results indicate our novel centrifugation method may preclude the need for a LDF during select autotransfusion applications.

A one-step centrifugal ultrafiltration method to concentrate enteric viruses from wastewater.

A one-step centrifugal ultrafiltration method was developed to enhance rapid detection of human enteric viruses and co-occurring viruses in wastewater. Samples were collected pre- and post-UV treatment at two full-scale tertiary municipal wastewater treatment plants in Calgary, Canada. Viruses were concentrated from 100mL wastewater samples through direct centrifugation using the Centricon Plus-70 ultrafilter. Seven viruses, including norovirus, rotavirus, sapovirus, astrovirus, enterovirus, adenovirus and JC virus, were tested using real-time quantitative PCR (rt-qPCR) and cell culture. All of the viruses were detected in pre- and post-UV samples by rt-qPCR, with rotavirus the most numerous (6.6 log10 GE copies/L). Infectious viruses, by cell culture, were found in all tested pre-UV samples but only in one post-UV sample. The results were comparable and consistent to that obtained using virus adsorption-elution method, indicating that the centrifugal ultrafiltration method is adequate to retain the viruses and maintain their infectivity during processing. As a simple, rapid and cost-effective method to screen wastewater viruses, this one-step centrifugal ultrafiltration method may serve as an effective approach to assess virus removal and gain knowledge of human virus activity during wastewater treatment.

Polyethersulfone/polyacrylonitrile blended ultrafiltration membranes: preparation, morphology and filtration properties.

Polyethersulfone (PES)/polyacrylonitrile (PAN) membranes have been paid attention among membrane research subjects. However, very few studies are included in the literature. In our study, asymmetric ultrafiltration (UF) membranes were prepared from blends of PES/PAN with phase inversion method using water as coagulation bath. Polyvinylpyrrolidone (PVP) with Mw of 10,000 Da was used as pore former agent. N,N-dimethylformamide was used as solvent. The effects of different percentage of PVP and PES/PAN composition on morphology and water filtration properties were investigated. Membrane performances were examined using pure water and lake water filtration studies. Performances of pure water were less with the addition of PAN into the PES polymer casting solutions. However, long-term water filtration tests showed that PES/PAN blend membranes anti-fouling properties were much higher than the neat PES membranes. The contact angles of PES/PAN membranes were lower than neat PES membranes because of PAN addition in PES polymer casting solutions. Furthermore, it was found that PES/PAN blend UF membranes' dynamic mechanical analysis properties in terms of Young's modules were less than neat PES membrane because of decreasing amount of PES polymer.