Removal Of Urea Research Articles

Urease immobilized core–shell magnetic Fe[NiFe]O4/alginate and Fe3O4/alginate composite beads with improved enzymatic stability properties: removal of artificial blood serum urea

Urease immobilized core–shell magnetic Fe[NiFe]O4/alginate and Fe3O4/alginate composite beads with improved enzymatic stability properties: removal of artificial blood serum urea

Precision medicine in transplantation and hemodialysis.

In kidney transplantation, precision medicine has already entered clinical practice. Donor and recipient human leucocyte antigen (HLA) regions are genotyped in two class 1 and usually three class 2 loci, and the individual degree of sensitization against alloimmune antigens is evaluated by the detection of anti-HLA donor-specific antibodies. Recently, the contribution of non-HLA mismatches to outcomes such as acute T- and B-cell-mediated rejection and even long-term graft survival was described. Tracking of specific alloimmune T- and B-cell clones by next generation sequencing and refinement of the immunogenicity of allo-epitopes specifically in the interaction with HLA and T- and B-cell receptors may further support individualized therapy. Although the choices of maintenance immunosuppression are rather limited, individualization can be accomplished by adjustment of dosing based on these risk predictors. Finally, supplementing histopathology by a transcriptomics analysis allows for a biological interpretation of the histological findings and avoids interobserver variability of results. In contrast to transplantation, the prescription of hemodialysis therapy is far from precise. Guidelines do not consider modifications by age, diet or many comorbid conditions. Patients with residual kidney function routinely receive the same treatment as those without. A major barrier hitherto is the definition of ‘adequate’ treatment based on urea removal. Kt/Vurea and related parameters neither reflect the severity of uremic symptoms nor predict long-term outcomes. Urea is poorly representative for numerous other compounds that accumulate in the body when the kidneys fail, yet clinicians prescribe treatment based on its measurement. Modern technology has provided the means to identify other solutes responsible for specific features of uremic illness and their measurement will be a necessary step in moving beyond the standardized prescription of hemodialysis.

Molecular insight into COF monolayers for urea sorption in artificial kidneys

Urea removal from an aqueous solution is considered a challenge in the biological process. The state of complete kidney destruction is known as an end-stage renal disease (ESRD). Kidney transplant and hemodialysis are the most common methods for confronting ESRD. More recently, wearable artificial kidney (WAK) devices have shown a significant improvement in urea removal performance. However, low efficiency in physical adsorbents is a barrier in developing them. For the first time, the urea adsorption capacity of five types of last-generation covalent organic framework (COF) nanosheets (NSs) was investigated in this study by applying molecular dynamics (MD) simulation tools. To this end, different analyses have been performed to evaluate the performance of each nanoparticle. The MD all-atom (AA) results demonstrated that all introduced COF NSs had urea removal capacity. Among the five NSs, TPA-COF was shown to have the best outcomes. Moreover, coarse-grained (CG) and density functional theory (DFT) simulations were conducted, and the results show that the TPA-COF nanoparticle modified with –OH functional group has even better properties for urea adsorption. The present molecular study sheds new light on COF NSs as an adsorbent for urea removal.

The benefits of autotrophic nitrogen removal from high concentration of urea wastewater through a process of urea hydrolysis and partial nitritation in sequencing batch reactor

For the sake of high efficiency and saving operational cost for high-concentration urea wastewater treatment, a novel two-stage partial nitritation (PN)-anammox process containing simultaneous urea hydrolysis and PN in sequencing batch reactor (SBR) was investigated. Although the influent urea concentration increased from 500 to 1200 mg/L, the SBR simultaneously achieved urea removal efficiency higher than 98% and stable PN with effluent NO2−-N/NH4+-N ratio of 1.0–1.3 without any extra alkalinity addition. The intracellular hydrolysis was the dominant mechanism for urea removal and persistent free ammonia inhibition on nitrite-oxidizing bacteria was the main reason for nitrite accumulation of 97.92% in SBR. The subsequent anammox reactor showed efficient nitrogen removal performance with average ammonium removal efficiency, nitrogen removal efficiency and maximum nitrogen removal loading rate of 98.08%, 81.45% and 1.05 kg N·m−3·d−1 respectively. High-throughput sequencing results indicated Gemmatimonadetes became the most abundant bacterial phylum related to potential intracellular urea hydrolysis and displayed obvious ammonium-oxidizing bacteria enrichment and nitrite-oxidizing bacteria inhibition in SBR, and the dominant anammox bacteria (Candidatus_Kuenenia) in anammox reactor. The proposed process was proven to be promising for high-concentration urea wastewater treatment, facilitating the sustainable development of the urea industry in the future.

Molecular insight into optimizing the N- and P-doped fullerenes for urea removal in wearable artificial kidneys

Urea is the result of the breakdown of proteins in the liver, the excess of which circulates in the blood and is adsorbed by the kidneys. However, in the case of kidney diseases, some products, specifically urea, cannot be removed from the blood by the kidneys and causes serious health problems. The end-stage renal disease (ESRD) patients are not able to purify their blood, which endangers their life. ESRD patients require dialysis, a costly and difficult method of urea removal from the blood. Wearable artificial kidneys (WAKs) are consequently designed to remove the waste from blood. Regarding the great amount of daily urea production in the body, WAKs should contain strong and selective urea adsorbents. Fullerenes—which possess fascinating chemical properties—have been considered herein to develop novel urea removal adsorbents. Molecular dynamics (MD) has enabled researchers to study the interaction of different materials and can pave the way toward facilitating the development of wearable devices. In this study, urea adsorption by N-doped fullerenes and P-doped fullerenes were assessed through MD simulations. The urea adsorption was simulated by five samples of fullerenes, with phosphorous and different nitrogen dopant contents. For comparing the urea adsorption capacity in the performed simulations, detailed characteristics—including the energy analysis, radius of gyration, radial distribution function (RDF), root-mean-square fluctuation (RMSD), and H-bond analyses were investigated. It had been determined that the fullerene containing 8% nitrogen—with the highest reduction in the radius of gyration, the maximum RDF, a high adsorption energy, and a high number of hydrogen bonds—adsorbs urea more efficiently.

Safety of a Novel Dialyzer Containing a Fluorinated Polyurethane Surface-Modifying Macromolecule in Patients with End-Stage Kidney Disease

Background: By inhibiting the adsorption of protein and platelets, surface-modifying macromolecules (SMMs) may improve the hemocompatibility of hemodialyzers. This trial aims to assess the performance and safety of a novel dialyzer with a fluorinated polyurethane SMM, Endexo™. Methods: This prospective, sequential, multicenter, open-label study (NCT03536663) was designed to meet regulatory requirements for clinical testing of new hemodialyzers, including assessment of the in vivo ultrafiltration coefficient (Kuf). Adults prescribed thrice-weekly hemodialysis were eligible for enrollment. After completing 12 hemodialysis sessions with an Optiflux® F160NR dialyzer, patients received 38 sessions with the dialyzer with Endexo. Evaluated parameters included the in vivo Kuf of the dialyzer with Endexo extent of removal of urea, albumin, and β2-microglobulin (β2M), as well as complement activation. Results: Twenty-three patients received 268 hemodialysis treatments during the Optiflux period, and 18 patients received 664 hemodialysis treatments during the Endexo period. Three serious adverse events were reported, and none of them were considered device related. No overt complement activation was observed with either dialyzer. Both dialyzers were associated with comparable mean increases in serum albumin levels from pre- to posthemodialysis (Optiflux: 7.9%; Endexo: 8.0%). These increases can be viewed in the context of a mean increase in hemoglobin of approximately 5% and a mean ultrafiltration volume removed of approximately 2.2 L. The corrected mean β2M removal rate was 47% higher during the Endexo period (67.73%). Mean treatment times (208 vs. 205 min), blood flow rates (447.7 vs. 447.5 mL/min), dialysate flow rates (698.5 vs. 698.0 mL/min), urea reduction ratio (82 vs. 81%), and spKt/V (2.1 vs. 1.9) were comparable for the Endexo and Optiflux periods, respectively. The mean (SD) Kuf was 15.85 (10.33) mL/h/mm Hg during the first use of the dialyzer with Endexo (primary endpoint) and 16.36 (9.92) mL/h/mm Hg across the Endexo period. Conclusions: The safety of the novel dialyzer with Endexo was generally comparable to the Optiflux dialyzer, while exhibiting a higher β2M removal rate.

Prescribing Home Hemodialysis.

Home hemodialysis (HHD), performed more frequently than in-center hemodialysis, is underutilized in the United States but has had a recent resurgence driven predominantly by innovative dialysis equipment that is easy to use, less intrusive to the home, and requires less storage space. There are 3 different hemodialysis machines approved for use in the home but currently NxStage™ accounts for the overwhelming majority of HHD patients. Therefore, it is the focus of this article. To minimize storage space in the home, the NxStage platform minimizes the volume of dialysate that is used per treatment. We refer to this method as the Frequent Low Dialysate Volume Approach (FLDVA). The approach to urea removal with the NxStage platform is much different compared to traditional in-center HD. To minimize the volume of dialysate per treatment, and still achieve target urea removal, the dialysate must be highly saturated. In this article, we explain how to increase the saturation of dialysate fluid. We also draw a parallel between urea removal in peritoneal dialysis and NxStage therapy and use that model to estimate an initial HHD prescription and to alter prescriptions when necessary.

Recent advances and challenges in management of urea wastewater: A mini review

Treating the wastewater with high level of urea and ammonia-nitrogen is one of the problems faced by different plants in the world. The basic methods of urea removal of wastewater streams are electrochemical oxidation, biological treatment, adsorption and hydrolysis using thermal treatment or enzymes and decomposition with the aid of catalyst, strong oxidant. This work reviewed recent of different nanosized and nanostructured particles in different techniques for urea removal from wastewater and the challenges for treatments to draw the attention of researchers and scientists toward novel research ideas in this area.

Predialytic versus Intradialytic Nutrition: A Study to Assess Effects on Intradialytic Blood Pressure, Dialysis Adequacy, and Urea Removal

Background: Provision of oral protein in hemodialysis (HD) is desirable due to improved compliance to protein requirements and better nutritional status, but the risks of hypotension and underdialysis need to be considered. This study compared 2 different timings for administering oral nutritional supplements (ONS), predialysis and mid-dialysis, with respect to hemodynamics, dialysis adequacy, urea removal, and tolerability. Methods: This single-center, prospective crossover study analyzed 72 stable patients with ESRD on twice a week maintenance HD with a mean age of 38.7 (±11.2) years and a dialysis vintage of 28.2 (±13.1) months. In the first week, all the patients received ONS (450 kcal energy, 20 g protein) 1 h prior to start of dialysis (group 1) and in the next week, the supplement was administered after 2 h of start of dialysis (group 2), with a predialysis fasting period of at least 3 h in both groups. Blood pressures, serum, and spent dialysate samples were collected and nausea occurrence was noted by severity. Results: Predialytic intake (group 1) was associated with higher predialysis and 1st hour blood urea, dialysis adequacy, and urea removal than group 2. Both groups achieved mean Kt/V > 1.2, and the occurrence of symptomatic hypotensive episodes and nausea was not significantly different between the groups. On repeated measures ANOVA, changes in blood urea over time showed significant group effect. Conclusions: Predialytic supplementation was associated with better dialysis adequacy and urea removal than intradialytic supplementation. However, both timings were equally tolerated and not associated with underdialysis.

Photolysis of N-chlorourea and its effect on urea removal in a combined pre-chlorination and UV254 process

Urea is one of the most important nitrogenous organic pollutants in water, and its removal attracts attention because of a growing concern related to water eutrophication. Urea has previously been considered to be largely unaffected by the UV-chlorine process. However, N-chlorourea, an intermediate of urea chlorination, has been shown to absorb ultraviolet radiation, and as such its photolysis is possible. Experiments were conducted to quantify the kinetics of N-chlorourea degradation under UV254 irradiation. The results showed that about 92% of N-chlorourea was degraded under UV254 irradiation. Ammonia and nitrate were detected as the primary nitrogen containing products of the photolysis of N-chlorourea. Solution pH ranging from 3.0 to 7.5 influenced the distribution of these products but not on the degradation rate. Based on these data, a possible pathway of photodegradation of N-chlorourea under UV254 is proposed. The degradation of urea was also achieved by the photolysis of N-chlorourea during the combined pre-chlorination and UV254 process. Insights gained in this study may be useful for exploring the potential of combined pre-chlorination and UV254 process on urea removal in water treatment.

Effect of Polymer Loading on Membrane Properties and Uremic Toxins Removal for Hemodialysis Application

The adequacy of uremic toxins removal via hemodialysis treatment is essential for every kidney failure patient. To obtain hemodialysis adequacy, the effects of main polymer were investigated. The hollow fiber membranes were produced by using dry/wet spinning process from dope solution comprising PES as the main polymer, 3% poly(vinyl pyrrolidone) (PVP) in 1-methyl-2-pyrrolidone (NMP) at 40-cm air gap. PES loadings of 14, 16, and 18 wt.% were studied. The membrane morphology was characterized by using a scanning electron microscope (SEM) and the membrane properties were measured by using contact angle measurement (WCA). Membrane performance was evaluated by pure water flux (PWF), retention to bovine serum albumin (BSA), p-cresol and urea removal (URR) by using cross-flow permeation system. SEM analysis showed the asymmetric finger-like structure obtained for each polymer loading. The dense skin layer in the inner surface had thickened, followed by the increasing polymer weight loading. The 14 wt.% PES loading had a better pore size (116 nm) and porosity (74%). The WCA showed that the hollow fiber membranes studied were hydrophilic, and the utilization of 14 wt.% PES loading obtained better PWF (108.58 Lm-2h-1). However, this result had an impact on the impairment of BSA retention. The BSA retention for 14 wt.% PES loadings was 88.23%. The URR and p-cresol removal for 14 wt.% PES loading was higher (80.90% and 36.85% for 4 h, respectively) compared to others. As a conclusion, the percentage weight loading for polymer was a significant influence for morphology, membrane properties, and uremic toxins removal.

Urea removal using electrocoagulation process with copper and iron electrodes

Urea removal using electrocoagulation process with copper and iron electrodes

Silicon oxide-protected nickel nanoparticles as biomass-derived catalysts for urea electro-oxidation

The urea electro-oxidation reaction (UOR) is explored as a new technique for energy conversion and the removal of urea via electrochemical means in wastewater. Nickel (Ni) nanoparticles grown on nanosheets were prepared by a facile hydrothermal reaction and a subsequent calcination process of silicon oxide/nitrogen-doped carbon (SiOx/NC) as the precursor, in which SiOx/NC with a natural three-dimensional (3D) interconnected structure was obtained from bamboo leaves. The nickel/silicon oxide/nitrogen-doped carbon (Ni/SiOx/NC, denoted as Y) obtained at 900 °C (Y3), exhibits the most optimal catalytic properties for the UOR with a low potential of 1.384 V vs. RHE at 10 mA cm−2. The protective role of SiOx was also explored via the partial etching of SiOx (Y3-NaOH), and the results show that the overpotential of the curve increased rapidly after long-term test. The findings indicate that full exploitation of the comprehensive advantages of biomass materials is beneficial for alleviating the problems encountered in the development of energy-related technologies.

Rapid in situ synthesis of MgAl-LDH on η-Al2O3 for efficient hydrolysis of urea in wastewater

A rapid and efficient synthesis strategy of MgAl-LDH was proposed. MgAl-LDH with high specific surface area was synthesized in situ by using η-Al2O3 as carrier, and the synthesis time was greatly shortened by both increasing temperature and introducing ethanol as co-solvent. Besides, the growth process of MgAl-LDH on the surface of η-Al2O3 is also revealed. Under optimized conditions, the specific surface area of the MgAl-LDH is as high as 172.4 m2/g, the crystalline size is as small as 12.82 nm, and the basicity can reach 1.795 mmol/g. The urea wastewater was degraded from 8000 mg/L to 6.85 mg/L over the catalyst synthesized by the rapid method, and the catalyst still maintains high activity after four uses. Also, it was found that there is a good linear relationship between the urea removal rate and the basicity of MgAl-LDH.

Determining the appropriate pretreatment procedures and the utility of liver tissue for bulk stable isotope (δ13 C and δ15 N) studies in sharks.

Stable-isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into recent feeding/movement behaviours of this diverse group. To date, limited work has used this tissue, but ecological application of SIA in liver requires consideration of tissue preparation techniques given the potential for high concentrations of urea and lipid that could bias δ13 C and δ15 N values (i.e., result in artificially lower δ13 C and δ15 N values). Here we investigated the effectiveness of (a) deionized water washing (WW) for urea removal from liver tissue and (b) chloroform-methanol for extraction of lipids from this lipid rich tissue. We then (a) established C:N thresholds for deriving ecologically relevant liver isotopic values given complications of removing all lipid and (b) undertook a preliminary comparison of δ13 C values between tissue pairs (muscle and liver) to test if observed isotopic differences correlated with known movement behaviour. Tests were conducted on four large shark species: the dusky (DUS, Carcharhinus obscurus), sand tiger (RAG, Carcharias taurus), scalloped hammerhead (SCA, Sphyrna lewini) and white shark (GRE, Carcharodon carcharias). There was no significant difference in δ15 N values between lipid-extracted (LE) liver and lipid-extracted/water washed (WW) treatments, however, WW resulted in significant increases in %N, δ13 C and %C. Following lipid extraction (repeated three times), some samples were still biased by lipids. Our species-specific "C:N thresholds" provide a method to derive ecologically viable isotope data given the complexities of this lipid rich tissue (C:N thresholds of 4.0, 3.6, 4.7 and 3.9 for DUS, RAG, SCA and GRE liverLEWW tissue, respectively). The preliminary comparison of C:N threshold corrected liver and muscle δ13 C values corresponded with movement/habitat behaviours for each shark; minor differences in δ13 C values were observed for known regional movements of DUS and RAG (δ13 CDiffs = 0.24 ± 0.99‰ and 0.57 ± 0.38‰, respectively), while SCA and GRE showed greater differences (1.24 ± 0.63‰ and 1.08 ± 0.71‰, respectively) correlated to large-scale movements between temperate/tropical and pelagic/coastal environments. These data provide an approach for the successful application of liver δ13 C and δ15 N values to examine elasmobranch ecology.

Urea removal in rosé and red wines by immobilised acid urease in a packed bed reactor

The aim of this work was to develop and study the performance of a packed bed immobilized enzyme reactor for the effective removal of urea in high polyphenol wines. Purified acid urease from Lactobacillus fermentum was immobilized on Eupergit® C 250 L yielding a biocatalyst with enzyme loading and specific activity per g of dry support of 109.7 ± 2.4 mg and 677 ± 39 IU, respectively. Incubation of the developed biocatalyst at 20 °C in rosé and red wines resulted in a two-phase deactivation mechanism, with a residual asymptotic activity after about 170 h of 67% and 24%, respectively. The developed biocatalyst was used in a packed bed reactor with recycling to efficiently remove urea from rosé and red wines. A model for the bioreactor allowed to estimate the apparent pseudo-first order kinetic constant for urea hydrolysis, which for three repeated bioconversion cycles varied in the range 2.8–4.1 cm3 g−1 min−1 for the rosé wine and 1.1–2.7 cm3 g−1 min−1 for the red wine. Results of repeated bioconversion cycles allowed to conclude that enzyme deactivation by phenols is the main reason for the low urease activity observed in high polyphenol wines. This suggested the use of immobilization as a means to overcome the present limitations in the use of the free enzyme.

Cobalt-modified 2D porous organic polymer for highly efficient electrocatalytic removal of toxic urea and nitrophenol

The urea oxidation reaction (UOR) and nitrophenol reduction are safe and key limiting reactions for sustainable energy conversion and storage. Urea and nitrophenol are abundant in industrial and agricultural wastes, human wastewater, and in the environment. Catalytic oxidative and reductive removal is the most effective process to remove urea and 4-nitrophenol from the environment, necessary to protect human health. 2D carbon-supported, cobalt nanoparticle-based materials are emerging catalysts for nitrophenol reduction and as an anode material for the UOR. In this work, cobalt modified on a porous organic polymer (CoPOP) was synthesized and carbonized at 400 and 600 °C. The formation of CoPOP was confirmed by FT-IR spectroscopy, the 2D graphitic layer and amorphous carbon with cobalt metal by TEM, SEM, and PXRD, and the elemental composition by TEM mapping, EDX, and XPS. The catalytic activity for the 4-nitrophenol reduction was studied and the related electrocatalytic UOR was scientifically evaluated. The catalytic activity toward the reduction of 4-NP to 4-AP was tested with the addition of NaBH4; CoPOP-3 exhibited enhanced activity at a rate of 0.069 min−1. Furthermore, LSV investigated the catalytic activity of materials toward UOR, producing hydrogen gas, the products of which were analyzed via gas chromatography. Among the electrocatalysts studied, CoPOP-2 exhibited a lower onset potential, and the Tafel slope was 1.34 V and 80 mV dec−1. This study demonstrates that cobalt metal-doped porous organic polymers can be used as efficient catalysts to remove urea and nitrophenol from wastewater.

Pcal_0842, a highly thermostable glycosidase from Pyrobaculum calidifontis displays both α-1,4- and β-1,4-glycosidic cleavage activities

The gene encoding Pcal_0842, annotated as a cellulase (accession no. ABO08268), was cloned and expressed in Escherichia coli. The gene product was produced in insoluble form in E. coli in high amounts even without addition of the inducer isopropyl β-D-1-thiogalactopyranoside. The recombinant protein was solubilized in 8 M urea and refolded by gradual removal of urea. The refolded protein exhibited both α-1,4- and β-1,4-glycosidic cleavage activities. The enzyme activity increased with the increase in temperature till 120 °C. Apart from very high optimal temperature, recombinant Pcal_0842 was extremely thermostable. There was no significant loss in activity even after heating for 100 h at 100 °C. The half-lives of Pcal_0842 were 6 and 2.5 h at 110 and 120 °C, respectively. To the best of our knowledge, Pcal_0842 is the most thermostable glycosidase characterized to date and this is the first report on cloning and characterization of an enzyme from archaea that displays both α-1,4- and β-1,4-glycosidic cleavage activities.

DIALYSIS DISEQUILIBRIUM SYNDROME: WHEN THERAPY PRECIPITATES TOXICITY

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Dialysis disequilibrium syndrome (DDS) is characterized by a spectrum of neurologic symptoms that can affect patients on hemodialysis. Dialysis naive patients are more prone to this condition but it can also occur in patients who have missed several days of dialysis. Early features may be mild, including headache, nausea, and blurred vision, to severe symptoms such as somnolence, confusion, seizures, coma and death. CASE PRESENTATION: A 35 year old female, history of bipolar disorder and depression, presented to a small community hospital ED with confusion and lethargy. She was found to have an elevated creatinine in the setting of lithium toxicity. She was transferred to our facility for a higher level of care and on arrival was somnolent but hemodynamically stable. Initial laboratory studies were as shown below. CT of the brain showed no intracranial hemorrhage. Given the patient’s altered level of consciousness, and renal failure in the setting of lithium toxicity, emergent dialysis was recommended by nephrology. During dialysis, the patient became markedly hypotensive and obtunded. She required intubation for airway protection and vasopressor support. MRI of the brain showed diffuse cortical edema and herniation of the cerebellar tonsils. Brain death was declared independently by an intensivist and a neurologist. DISCUSSION: Our patient required emergent dialysis given her severe altered mental status, and renal failure secondary to lithium toxicity. Unfortunately, she went on to develop DDS. DDS usually affects patients who are undergoing their first dialysis session. The exact incidence is unknown but it is thought to be very rare. The broad nature of the symptoms makes it difficult to identify DDS. Risk factors include extremes of age, severe uremia, hypernatremia, hyperglycemia, preexisting neurologic abnormalities, and first dialysis treatment. DDS remains a clinical diagnosis of exclusion. One must rule out stroke, subdural hematoma, intracerebral hemorrhage, infection, and toxic encephalopathy among others. The cornerstone of treatment is prevention. Prevention entails identifying high-risk patients and utilizing intermittent hemodialysis, or CRRT using slow urea removal. The exact mechanism is not well understood, and there are no guidelines on appropriate dialysis settings. If symptoms are mild, one can consider reducing the blood flow rate, but if patients display severe neurologic abnormalities, one should strongly consider stopping the dialysis session. CONCLUSIONS: DDS is a rare but potentially lethal clinical entity. Early recognition, prompt cardiopulmonary resuscitation, and cessation of the dialysis session are of paramount importance in managing patients with severe DDS. Reference #1: Mistry K. Dialysis disequilibrium syndrome prevention and management. Int J Nephrol Renovasc Dis. 2019;12:69–77. Published 2019 Apr 30. doi:10.2147/IJNRD.S165925 Reference #2: Bagshaw SM, Peets AD, Hameed M, Boiteau PJ, Laupland KB, Doig CJ. Dialysis Disequilibrium Syndrome: brain death following hemodialysis for metabolic acidosis and acute renal failure--a case report. BMC Nephrol. 2004;5:9. Published 2004 Aug 19. doi:10.1186/1471-2369-5-9 DISCLOSURES: No relevant relationships by Krystal Alexander, source=Web Response No relevant relationships by John Paul Papadopoulos, source=Web Response No relevant relationships by Nirvi Shah, source=Web Response

High-Performance Hemodialysis Membrane: Influence of Polyethylene Glycol and Polyvinylpyrrolidone in the Polyethersulfone Membrane

the preparation of high-performance hemodialysis membrane, the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and also the simultaneous effect of both additives in the polyethersulfone (PES) membrane were investigated. Viscosity measurements demonstrated that PVP has better compatibility with PES, owing to the amorphous nature, closer glassy transition temperature (Tg), and solubility parameters rather than PEG (semi-crystalline and low Tg). This could lead to enhancement in the solution viscosity. SEM results revealed that membranes morphology was dependent upon casting solution viscosity and with increasing viscosity; the formation of macro-voids suppressed and achieving to a membrane with a smaller mean pore size would be possible. The results of the AFM study demonstrated that, with the addition of PVP, membranes with smooth surface were achieved. In contrast, the PEG addition led to a rougher membrane surface. The results verified that PEG had a tangible effect on the permeability of membrane rather than PVP or blend of PVP and PEG, which is owing to its impressive pore-forming role. The maximum pure water permeability (PWP) was achieved for MV4 (24.9 L/m2.h.bar), MG2 (44.8 L/m2.h.bar), MVG2 (25.2 L/m2.h.bar), and MVG3 (25.1 L/m2.h.bar). Rejection test showed that MV3, MV4, MG3, MG4, MVG2, and MVG3 had the best performance in terms of urea removal and maintaining other components, especially bovine serum albumin (BSA). In-vitro cytotoxicity demonstrated the biocompatibility of MV2, MG3, and MVG3 as representative of all membranes. The lactate dehydrogenase (LDH) test confirmed that PVP has a tangible effect on the reduction of platelet adhesion on the membrane surface.