Articoli di riviste: "Ultrafiltration"

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Tay, Kirsty Luo-Yng, Abdel Rahman Osman, Esyn Ee Xin Yeoh, Jasmine Luangboriboon, Jie Fei Lau, Joanne Jia An Chan, Majed Yousif et al. "Ultrafiltration versus Diuretics on Prognostic Cardiac and Renal Biomarkers in Acute Decompensated Heart Failure: A Systematic Review and Meta-Analysis". Journal of Clinical Medicine 12, n. 8 (9 aprile 2023): 2793. http://dx.doi.org/10.3390/jcm12082793.

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Existing systematic reviews have insufficiently delineated the differing cardiac and renal profile of ultrafiltration compared to diuretics as a method of decongestion in acute decompensated heart failure. This meta-analysis will investigate the impact of ultrafiltration compared to diuretics on prognostic cardiac and renal biomarkers. We searched PubMed Central, Ovid MEDLINE®, Ovid Embase, all EBM reviews, and Web of Science Core Collection for randomised controlled trials published before 21 July 2022. Our main outcome measures were cardiac (brain natriuretic peptide and N-terminal pro-brain natriuretic peptide) and renal biomarkers (serum creatinine, serum sodium, and blood urea nitrogen). A total of 10 randomised trials were included in our analysis after screening. An inverse-variance random effects meta-analysis of the pooled results demonstrated no significant difference between ultrafiltration and diuretics for brain natriuretic peptide, N-terminal pro-brain natriuretic peptide, creatinine, sodium and long-term blood urea nitrogen. However, ultrafiltration produced statistically greater increases in blood urea nitrogen in the short-term (mean difference, 3.88; 95% confidence interval 0.59–7.17 mg/dL). Overall, ultrafiltration produces a similar impact on prognostic cardiac and renal biomarkers when compared to diuretic therapy. We highlight ultrafiltration’s significant impact on short-term BUN and recommend further research to investigate more optimal protocols of ultrafiltration administration.

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Petterson, Craig M., Alfred H. Stammers, Ryan J. Kohtz, Scott A. Kmiecik, Jeffrey D. Nichols, Nancy J. Mills e Jun-Li Liu. "The Effects of Ultrafiltration on e-Aminocaproic Acid: An In Vitro Analysis". Journal of ExtraCorporeal Technology 34, n. 3 (settembre 2002): 197–202. http://dx.doi.org/10.1051/ject/2002343197.

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Blood conservation strategies have become a standard of practice in cardiac surgery, with the use of antifibrinolytic agents and ultrafiltration two popular techniques. The purpose of this study was to evaluate the effects of continuous ultrafiltration on e-aminocaproic acid (EACA) utilizing functional coagulation analysis. A fibrinolytic assay was developed to detect EACA using the thromboelastograph (TEG) and urokinase (0.138 units 0.360 mL−1). Fresh bovine blood (23 ± 1% hematocrit) was pumped (100 mL min−1) through an ultrafiltrator (HPH 400) at 37°C with a transmembrane pressure of 280 mmHg. EACA (0.065 mg mL−1) was circulated for 10 minutes before initiating ultrafiltration. Samples (pre- and postultrafiltrator) were obtained at baseline, 5, and 10 min of ultrafiltration and analyzed via the fibrinolytic assay for EACA determination. TEG profiles significantly decreased from concentrations of 0.065 mg to 0.0325 mg of EACA mL−1 blood (maximum amplitude MA, 75.4 ± 4.0 versus 63.3 ± 2.9, p < .05, TEG index 5.4 ± 0.7 versus 4.0 ± 0.3, p < .05). Fibrinolysis at 30 min increased as EACA concentrations declined (0.065 mg, 0% versus 0.032 mg, 16.4 ± 2.8%, p < .05). During ultrafiltration the MA increased significantly from baseline to 10 min postultrafiltrator (68.2 ± 3.0 versus 75.8 ± 10.0, p < .05) and from 5 min pre- to 10 min postultrafiltrator (69.7 ± 4.2 versus 75.8 ± 10.0, p < .05). The TEG index showed no significant change, and no fibrinolysis was detected at 30 min from any datapoint during ultrafiltration. In conclusion, this study demonstrates that the antifibrinolytic properties of EACA are maintained during ultrafiltration with a 25% reduction in total circulating volume.

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Han, You Qi, De Ming Zhu, Zhou Kong Su e Wen Xiang Ding. "Ultrafiltration in Pediatric Cardiac Surgical Procedures". Journal of ExtraCorporeal Technology 23, n. 3 (settembre 1991): 63–65. http://dx.doi.org/10.1051/ject/199123363.

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Ultrafiltration is an extracorporeal technique that employs the principle of convective solution transport across a semipermeable membrane and by which plasma water is removed from the dilute blood during cardiopulmonary bypass. Ultrafiltration has been used in 40 pediatric cases who underwent corrective surgery for congenital heart disease (TOF 12, VSD 23, ASD 4 and PAVC 1) intraoperatively. The patients' ages ranged from 10months to 9 years (4.9±2.6yrs)and weights from 7 to 28kgs (16.4±5.8 kgs). The ultrafiltrator was interposed in the port of arterial filter of the CPB circuit and performed during the rewarming period. Ultrafiltration blood flow rate was 250-300 ml/ min and negative pressure was less than -250 mmHg. The average ultrafiltrability (total blood flow volume/ultrafiltration fluid volume) was 11.2%(10.7-12.1%). After ultrafiltration HCT increased from 16.1 %(15-18%) to 34.7%(32-40%). In the ICU, 5 cases (TOF 3, VSD 1 and ASD 1) had hemoglobinuria. The indications of ultrafiltration in pediatric cardiac surgery are: 1. The initial perfusion is conducted with bloodless priming or with blood priming when the HCT value dropped to lower than 17% during CPB. 2. The CPB time is longer than 2 hours. 3. The patient receives digoxin and diuretics preoperatively or has complex anomals. Our experience showed that ultrafiltration during pediatric CPB is facile, safe, and effective. It may result in a reduced amount of fluid accumulation in extracellular fluid space with hemodilution perfusion which benefits the patients postoperative recovery. Hemoconcentration of dilute blood during cardiopulmonary bypass(CPB) by plasma water removal is an extracorporeal technique application by ultrafiltration during the pediatric open-heart surgery. Usually after CPB, especially in infant cases, the residual pump blood volume is much more than the acceptable volume for postoperative transfusion. Therefore, the transfusing of large volumes of dilute blood with low colloid oncotic pressure to the patient may cause circulatory overload with normovolumic anemia and result in significant fluid diffusion into interstitial space. In order to save the residual pump blood and reduce such ill effects and complications, we applied ultrafiltration on 40 pediatric cases during open-heart surgical procedures. Our clinical data, ultrafiltration application indications and recommended procedures are now presented.

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Ming, Zhu De, Wang Wei, Chen Hong, Zhang Wei e Ding Wen Xiang. "Balanced Ultrafiltration, Modified Ultrafiltration, and Balanced Ultrafiltration with Modified Ultrafiltration in Pediatric Cardiopulmonary Bypass". Journal of ExtraCorporeal Technology 33, n. 4 (dicembre 2001): 223–26. http://dx.doi.org/10.1051/ject/2001334223.

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This study evaluates the effect of balanced ultrafiltration, modified ultrafiltration, and balanced ultrafiltration with modified ultrafiltration on inflammatory mediators in children’s open-heart surgery. Eighty children with congenital heart disease were randomly divided into four groups: control group (C group); balanced ultrafiltration group (BUF group); modified ultrafiltration group (MUF group); and balanced ultrafiltration with modified ultrafiltration group (B+M group). Clinical data of these groups were similar. Tumor necrosis factor (TNF), interleukin-8(IL-8), and E-selectin were measured at the beginning of cardiopulmonary bypass (CPB), 30 min later, at the cessation of CPB, at the cessation of MUF (MUF group and B+M group), and 2 hours postoperatively. During CPB, the concentrations of TNF, IL-8, and E-selectin increased significantly in C and MUF groups and did not change significantly in BUF and B+M groups. In the period of MUF, TNF and IL-8 increased; whereas, Eselectin did not change. The study shows that ultrafiltration can filter out the inflammatory mediators, but only BUF can decrease the concentrations of them. Moreover, MUF only can concentrate blood. Combining both techniques has both effects, but the effect of BUF was offset by MUF.

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Soat, Marian. "Ultrafiltration". Nursing Management (Springhouse) 39, n. 1 (gennaio 2008): 48–49. http://dx.doi.org/10.1097/01.numa.0000305993.07980.51.

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Bourge, Robert C., e José A. Tallaj. "Ultrafiltration". Journal of the American College of Cardiology 46, n. 11 (dicembre 2005): 2052–53. http://dx.doi.org/10.1016/j.jacc.2005.09.014.

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Babka, Ronald M., James Petress, Richard Briggs, Robert Helsel e John Mack. "Conventional haemofiltration during routine coronary bypass surgery". Perfusion 12, n. 3 (maggio 1997): 187–92. http://dx.doi.org/10.1177/026765919701200307.

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The use of conventional ultrafiltration during cardiopulmonary bypass (CPB) has been well recognized as an efficient modality of therapy to reverse the effects of deliberate haemodilution. Routine use of the haemofilter was prospectively studied on 60 patients undergoing coronary artery bypass surgery. Group A consisted of 30 patients on whom the ultrafiltrator was used and compared to group B who did not receive the ultrafiltration technique. The COBE 1200 ultrafiltration device was used. The results of the study demonstrated that, in group A, the mean total amount of ultrafiltrate collected during bypass was 2510 ± 804 ml per patient. The mean 24-h postoperative blood loss was 440 ± 192 ml in group A and 451 ± 136 ml in group B. The average bank blood transfused was 0.6 ± 1.3 units per patient in group A and 0.75 ± 1.5 units per patient in group B. Postoperative weight gain in group A averaged 3.5 ± 3.45 lb per patient, compared to 4.8 ± 3.7 lb per patient in group B. Postoperative length of stay averaged 6.4 ± 1.5 days per patient in group A and 6.4 ± 2.1 days per patient in group B. Overall patient charges averaged $33 706 ± 8348 per patient in group A and $33 041 ± 7674 per patient in group B. It was concluded that routine use of ultrafiltration during routine coronary artery bypass surgery with CPB offers no improvement in the quality of care nor does it decrease the patient’s overall charges.

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Babenyshev, S. P., V. E. Zhidkov, D. S. Mamay, V. P. Utkin e N. A. Shapakov. "ULTRAFILTRATION OF MODIFIED MILK WHEY". Food and Raw Materials 4, n. 2 (30 dicembre 2016): 101–10. http://dx.doi.org/10.21179/2308-4057-2016-2-101-110.

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Lazarev, Sergey I., Yuri V. Golovin, Irina V. Khorokhorina, Sergey V. Kovalev e Alexandr A. Levin. "KINETIC AND STRUCTURAL CHARACTERISTICS OF ULTRAFILTRATIONAL MEMBRANES AT SEPARATION OF SOLUTIONS CONTAINING SODIUM LAURYLSULPHATE". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, n. 10 (29 ottobre 2019): 89–95. http://dx.doi.org/10.6060/ivkkt.20196210.6031.

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In work the generalized analysis of literary data on a research of relative permeability ratio of various types of porous organic and inorganic membranes was submitted. Application of a method of X-ray analysis of samples of the semipermeable ultrafiltrational membranes on a diffractometer of DRON-3 and a specific output flow on a flat-chamber ultrafiltration unit is shown. In materials of work the pilot and theoretical studies on isokinetic zones and structural characteristics of polymeric semipermeable membranes in the course of ultrafiltrational separation of the technological solutions containing the anionic and fissile surface substances are conducted. It is experimentally confirmed that kinetic curves on a specific output flow have two isokinetic zones. The first zone, the stage of the ultrafiltration process, proceeds quickly, lasts only a few minutes - 7.8 min and 13.05 min, the second zone is slower with duration of about 30 min and 60 min for ultrafiltration cellulose acetate membranes of the UAM-100 and UAM-50 series, respectively. The revealed isokinetic zones differ in characteristic times, which differ by orders of magnitude, and, as a result, the final kinetic dependence has an exponential form. The comparative analysis of roentgenograms allows to note coincidence of angles of diffraction, but significant redistribution of intensity of reflexes in air-dried and working sapless in the range of scattering angles 2θ from 8°-35°. The obtained experimental data and their comparison with literary, indicate the same set of the diffraction reflexes at corners 2θ = 17°; 22°; 25° for both samples of membranes that corresponds to the crystal reflexes of membranes created from polyamide fibers (nylon).

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Liu, Shu Xing, e Bei Wang. "Purification of Ferulic Acid from Wheat by Ultrafiltration Technology". Advanced Materials Research 524-527 (maggio 2012): 2294–97. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.2294.

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Purification extraction of ferulic acid from wheat bran by using ultrafiltration,based on the molecular weight cutoff (MWCO) of ultrafiltration membranes,ultrafiltration pressure,sample concentration,ultrafiltration time these four factors influence of the membrane flux,determine the best the ultrafiltration conditions.

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Cherkasov, A. N. "Selective ultrafiltration". Journal of Membrane Science 50, n. 2 (giugno 1990): 109–30. http://dx.doi.org/10.1016/s0376-7388(00)80310-5.

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McCray, Scott B. "Ultrafiltration Handbook". Journal of Membrane Science 32, n. 2-3 (luglio 1987): 341–42. http://dx.doi.org/10.1016/s0376-7388(00)85017-6.

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Jönsson, A. "Ultrafiltration applications". Desalination 77, n. 1-3 (marzo 1990): 135–79. http://dx.doi.org/10.1016/0011-9164(90)80008-y.

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Jönsson, Ann-Sofi, e Gun Trägårdh. "Ultrafiltration applications". Desalination 77 (marzo 1990): 135–79. http://dx.doi.org/10.1016/0011-9164(90)85024-5.

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Li, Yinghua, Yiyan Wang, Mengxi Liao, Fei Su, Yue Zhang e Linlin Peng. "Effects of electroflocculation/oxidation pretreatment on the fouling characteristics of ultrafiltration membranes". Water Science and Technology 85, n. 4 (21 gennaio 2022): 1079–89. http://dx.doi.org/10.2166/wst.2022.016.

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Abstract In order to reduce the membrane pollution of ultrafiltration caused by natural organic matter and improve the treatment efficiency, electroflocculation/oxidation is used as the premembrane treatment method. The membrane specific flux attenuation characteristics was compared and analyzed under the conditions of direct ultrafiltration and electroflocculation/oxidation-ultrafiltration. Combined with the analysis of the reversibility of membrane fouling, the mechanism of electroflocculation/oxidation pretreatment to alleviate ultrafiltration membrane fouling was evaluated, and the membrane pore clogging model was used to fit the fouling law. The results show that, in the continuously fed filtration experiment, the electroflocculation/oxidation process involved in the pretreatment and the direct ultrafiltration membrane filtration decreased the ultrafiltration membrane flux to 79.1% and 28.5%, respectively. The reversible resistance generated by ultrafiltration and electroflocculation/oxidation-ultrafiltration processes accounted for 37.70% and 62.26% of their total pollution resistance, whereas the irreversible resistance generated accounted for 47.30% and 12.40%, respectively. Meanwhile, the direct correlation between the the flux dropped and complete clogging became less than that of the ultrafiltration process. The pretreatment significantly strengthened irreversible fouling resistance of the membrane pores. The membrane permeation flux was significantly increased after the electroflocculation/oxidation pretreatment.

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Elliott, Martin J. "Ultrafiltration and modified ultrafiltration in pediatric open heart operations". Annals of Thoracic Surgery 56, n. 6 (dicembre 1993): 1518–22. http://dx.doi.org/10.1016/0003-4975(93)90744-3.

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Naik, SK, A. Knight e MJ Elliott. "A successful modification of ultrafiltration for cardiopulmonary bypass in children". Perfusion 6, n. 1 (gennaio 1991): 41–50. http://dx.doi.org/10.1177/026765919100600106.

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Total body water (TBW) is increased after cardiopulmonary bypass (CPB) resulting in tissue oedema and organ dysfunction. Ultrafiltration has been used to reduce this accumulation of water, although conventional ultrafiltration seemed ineffective in reducing the rise in TBW after CPB in our clinical experience. We describe a modified technique in which ultrafiltration is performed in the first 10 minutes after the patient is weaned from bypass, returning nearly all the blood in the circuit to the patient and elevating the haematocrit (Hct) to any predetermined level. We carried out a pilot study on 21 children aged 4-144 months undergoing open-heart surgery and CPB for congenital heart defects. They were divided into three comparable groups: (1) controls (n = 6); (2) conventional ultrafiltration (n = 7); and (3) modified ultrafiltration (n = 8). TBW (bio-impedance), Hct, osmolality, mean corpuscular volume and mean corpuscular haemoglobin concentration were recorded at frequent intervals. Control patients showed elevation of TBW by 18.2% median (range 14.5-20.3), conventional ultrafiltration by 12.4% (7.9-15.0), modified ultrafiltration by 5.7% (4.5-7.1) (p < 0.0001 compared to controls, p < 0.005 compared to conventional ultrafiltration, Mann-Whitney U test). Hct could be elevated to preoperative levels only by the modified method. Mean corpuscular volume, and mean corpuscular haemoglobin concentration osmolality were unaltered. Ultrafiltration by the modified method was more effective than conventional ultrafiltration in reducing the rise in TBW and elevating Hct after CPB.

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Krack, Genevieve, Giusto Viglino, Pier Luigi Cavalli, Carmen Gandolfo, Giuseppe Magliano, Alberto Cantaluppi e Franco Peluso. "Intraperitoneal Administration of Phospha Tidylcholine Improves Ul Trafil Tration in Continuous Ambulatory Peritoneal Dialysis Patients". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 12, n. 4 (ottobre 1992): 359–64. http://dx.doi.org/10.1177/089686089201200405.

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Reports in the literature have linked a low phosphatidylcholine content in continuous ambulatory peritoneal dialysis {CAPD) effluent to ultrafiltration loss. Clinical evidence suggests that adding phosphatidylcholine to the dialysis solution enhances ultrafiltration. A clinical study has been designed to clarify the effect of phosphatidylcholine on ultrafiltration in CAPD patients with normal ultrafiltration. A weekly measurement of the peritoneal equilibration test was conducted per patient in the hospital. A comparison between the control dialysis solution {three-week period) and the phosphatidylcholine premixed solution {three-week period) was performed on a total of 12 patients. This study shows that a phosphatidylcholine premixed dialysis solution significantly enhances ultrafiltration. Since ultrafiltration per osmotic driving force (mUg glucose) is enhanced, the patient's glucose load per day is reduced to achieve equal ultrafiltration. In the presence of phosphatidylcholine, peritoneal permeability remained unchanged, as indicated by membrane transport characteristics. No side effects were observed.

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Krediet, Raymond T., Colin B. Brown, Alexander L. T. Imholz e Gerardus C. M. Koomen. "Protein Clearance and Icodextrin". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 14, n. 2_suppl (febbraio 1994): 39–44. http://dx.doi.org/10.1177/089686089401402s06.

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Objective To analyze the peritoneal transport of serum proteins during continuous ambulatory peritoneal dialysis (CAPD) with icodextrin. Design A comparison was made between CAPD with glucose-based dialysate and, in the same patients, 4 weeks after the instillation of icodextrin for the long night dwell, with icodextrin-based dialysate. Patients Ten stable CAPD patients, who participated in a large randomized multicenter study comparing icodextrin with glucose-based dialysate. Five patients used glucose 1.5% dialysate for the night dwell before its replacement by icodextrin (good ultrafiltration group), and 5 used glucose 4.25% (poor ultrafiltration group). Results The clearance of β2-microglobulin increased by 28% on icodextrin, due to increased convective transport. The clearances of the larger proteins -albumin, IgG, fibronectin, and α2-macroglobulin -remained unaltered, indicating transport of these proteins across the large pore system. The patients with poor ultrafiltration had a higher β2-microglobulin clearance on glucosebased dialysate than the high ultrafiltration group. This indicates that the ultrafiltration failure was caused by a large effective peritoneal surface area, leading to a rapid absorption of glucose. Icodextrin produced significantly more ultrafiltration in the poor ultrafiltration patients than in the high ultrafiltration group. A correlation was found for the β2-microglobulin clearance on glucose-based dialysate and the ultrafiltration produced by icodextrin. Conclusions Icodextrin causes ultrafiltration through the small pore system, whereas glucose-based dialysate has its effect on transcellular water transport. Therefore, the use of icodextrin causes an increased clearance of β2 microglobulin, but not of larger proteins. Icodextrin was especially useful in patients with a large effective surface area leading to ultrafiltration failure during treatment with glucose-based dialysate.

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Mamay, Dmitriy, Sergey Babenyshev, Angelina Mamay e Vyacheslav Lisitsyn. "Ultrafiltration of skim milk microfiltration permeate". BIO Web of Conferences 116 (2024): 02015. http://dx.doi.org/10.1051/bioconf/202411602015.

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The purpose of the research conducted in the laboratory is to study the basic regularities of the ultrafiltration process of microfiltration permeate of skim milk, called native whey (NW). The objects of the research are NW, its ultrafiltration process and the obtained ultrafiltration retentate, NW permeate. To create the initial information base of the research work we used the results of the analysis of literature data from the libraries of the Russian State Library, North Caucasus Federal University, as well as the global network of the Internet and so on. Physicochemical characteristics of NW, as an object of ultrafiltration, were determined according to standard methods and on certified equipment. The main operating modes of the NW ultrafiltration process were determined experimentally. A mathematical expression allowing to quantitatively determine the permeability of ultrafiltration membrane depending on the working pressure, flow rate of circulation and temperature of the separated system was obtained. Quantitative indices of casein and whey proteins content in the resulting ultrafiltration retentate and permeate were determined. The results of the experimental research stage are the basis for the preparation of recommendations on the technology of ultrafiltration of NW with the use of pilot baromembrane equipment in industrial conditions. The obtained experimental data can be used as initial information for nanofiltration of ultrafiltration permeate. The field of application of the results is dairy industry.

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Bierer, Joel, Roger Stanzel, Mark Henderson, Suvro Sett e David Horne. "Ultrafiltration in Pediatric Cardiac Surgery Review". World Journal for Pediatric and Congenital Heart Surgery 10, n. 6 (novembre 2019): 778–88. http://dx.doi.org/10.1177/2150135119870176.

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Introduction: The use of cardiopulmonary bypass in pediatric cardiac surgery is associated with significant inflammation, fluid overload, and end-organ dysfunction yielding morbidity and mortality. For decades, various intraoperative ultrafiltration techniques such as conventional ultrafiltration, modified ultrafiltration (MUF), zero-balance ultrafiltration (ZBUF), and combination techniques (ZBUF-MUF) have been used to mitigate these toxicities and promote improved postoperative outcomes. However, there is currently no consensus on the ultrafiltration technique or strategy that yields the most benefit for infants and children undergoing open heart surgery. Methods: A librarian-conducted PubMed literature search from 1990 to 2018 yielded 90 clinical studies or publications on the various forms of ultrafiltration and the impact on physiologic markers and clinical outcomes. All publications were reviewed, summarized, and conclusions synthesized. The data sets were not combined for systematic or meta-analysis due to significant heterogeneity in study protocols and patient populations. Results: Modified ultrafiltration significantly promotes improved myocardial function, reduction in fluid overload, and reduced bleeding and transfusion complications. Furthermore, ZBUF has shown a consistent reduction in inflammatory cytokines and improved pulmonary function and compliance. There is conflicting evidence that MUF, ZBUF, and ZBUF-MUF culminate in reduced ventilation time and intensive care unit stay. Conclusion: Various modes of ultrafiltration have been shown to be associated with improved physiologic function or clinical outcomes in pediatric cardiac surgery. There are some inconsistent trial results that can be explained by heterogeneity in ultrafiltration, clinical staff preferences, and institution protocols. Ultrafiltration has some essential benefit as it is ubiquitously used at pediatric heart centers; however, the optimal protocol could be yet identified.

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Breborowicz, Andrzej, e Jan Knapowski. "Transmesothelial Ultrafiltration IN VITRO". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 6, n. 3 (luglio 1986): 124–27. http://dx.doi.org/10.1177/089686088600600303.

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The authors created transmesothelial ultrafiltration in vitro by inducing an osmotic gradient (vasc-300 mOsm: meso-400 mOsm) across the membrane. Calculated value of hydraulic conductivity of the mesothelium is comparable with analogous value for endothelium of the microvessels. They propose that transperitoneal ultrafiltration develops in two phases: Transmesothelial ultrafiltration, which augments tonicity of the interstitial tissue which is followed by transendothelial ultrafiltration due to the osmotic gradient between the dehydrated interstitium and the vascular space. Hypertonic medium on the mesothelial side of the membrane modified its permeability to various solutes: transport rate of urea and inulin was increased whereas transport rate of albumin decreased. Transperitoneal ultrafiltration of fluid during peritoneal dialysis conditions the removal of water from the organism. According to Nolph et al, the endothelium of the peritoneal microvessels plays a crucial role in this process (I). Little is known about the role of the mesothelium in transperitoneal ultrafiltration but patients with damaged mesothelium show decreased removal of water across the peritoneal membrane (2). This paper describes the results of an in vitro study on the transmesothelial, osmotically induced ultrafiltration.

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Teitelbaum, Isaac. "Ultrafiltration Failure in Peritoneal Dialysis: A Pathophysiologic Approach". Blood Purification 39, n. 1-3 (2015): 70–73. http://dx.doi.org/10.1159/000368972.

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Background: Ultrafiltration failure is a significant cause of technique failure for peritoneal dialysis and subsequent transfer to hemodialysis. Summary: Ultrafiltration failure is defined as failure to achieve at least 400 ml of net ultrafiltration during a 4 h dwell using 4.25% dextrose. Four major causes of ultrafiltration failure have been described. A highly effective peritoneal surface area is characterized by transition to a very rapid transport state with D/P creatinine >0.81. Low osmotic conductance to glucose is characterized by attenuation of sodium sieving and decreased peritoneal free water clearance to <26% of total ultrafiltration in the first hour of a dwell. Low effective peritoneal surface area manifests with decreases in the transport of both solute and water. A high total peritoneal fluid loss rate is the most difficult to diagnose clinically; failure to achieve ultrafiltration with an 8-10 h icodextrin dwell may provide a clue to diagnosis. Key Messages: Knowledge of the specific pathophysiology of the various causes of ultrafiltration failure will aid in the diagnosis thereof.

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Balafa, Olga, Anila Duni, Paraskevi Tseke, Karolos Rapsomanikis, Paraskevi Pavlakou, Margarita Ikonomou, Vasileios Tatsis e Evangelia Dounousi. "Survival of Peritoneal Membrane Function on Biocompatible Dialysis Solutions in a Peritoneal Dialysis Cohort Assessed by a Novel Test". Journal of Clinical Medicine 10, n. 16 (18 agosto 2021): 3650. http://dx.doi.org/10.3390/jcm10163650.

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Background: Longitudinal surveillance of peritoneal membrane function is crucial in defining patients with a risk of ultrafiltration failure. Long PD is associated with increased low molecular weight solute transport and decreased ultrafiltration and free water transport. Classic PET test only provides information about low molecular solute transport, and the vast majority of longitudinal studies are based on this test and include patients using conventional dialysates. Our aim was to prospectively analyze longitudinal data on peritoneal function in patients on biocompatible solutions using a novel test. Methods: Membrane function data were collected based on uni-PET (a combination of modified and mini PET). A total of 85 patients (age 61.1 ± 15.1 years) with at least one test/year were included. Results: The median follow up was 36 months (21.3, 67.2). A total of 219 PETs were performed. One-way repeated measures ANOVA showed that there were no statistically significant differences over time in ultrafiltration, free water transport, ultrafiltration through small pores, sodium removal, D/D0 and D/PCre in repeated PET-tests. Twenty-three tests revealed ultrafiltration failure in 16 (18.8%) patients. Those patients were longer on PD, had higher D/P creatinine ratios, lower ultrafiltration at one hour with lower free water transport and higher urine volume at baseline. Multivariate analysis revealed that the variation of ultrafiltration over repeated PET-tests independently correlated only with D/Pcreatinine, free water transport and ultrafiltration through small pores. Conclusions. Uni-PET is a combination of two tests that provides more information on the function of the membrane compared with PET. Our study on a PD cohort using only biocompatible solutions revealed that function membrane parameters remained stable over a long time. Ultrafiltration failure was correlated with increased D/P creatinine and decreased free water transport and ultrafiltration through small pores.

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Assa, Solmaz, Johanna Kuipers, Esmée Ettema, Carlo A. J. M. Gaillard, Wim P. Krijnen, Yoran M. Hummel, Adriaan A. Voors et al. "Effect of isolated ultrafiltration and isovolemic dialysis on myocardial perfusion and left ventricular function assessed with13N-NH3positron emission tomography and echocardiography". American Journal of Physiology-Renal Physiology 314, n. 3 (1 marzo 2018): F445—F452. http://dx.doi.org/10.1152/ajprenal.00368.2017.

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Hemodialysis is associated with a fall in myocardial perfusion and may induce regional left ventricular (LV) systolic dysfunction. The pathophysiology of this entity is incompletely understood, and the contribution of ultrafiltration and diffusive dialysis has not been studied. We investigated the effect of isolated ultrafiltration and isovolemic dialysis on myocardial perfusion and LV function. Eight patients (7 male, aged 55 ± 18 yr) underwent 60 min of isolated ultrafiltration and 60 min of isovolemic dialysis in randomized order. Myocardial perfusion was assessed by13N-NH3positron emission tomography before and at the end of treatment. LV systolic function was assessed by echocardiography. Regional LV systolic dysfunction was defined as an increase in wall motion score in ≥2 segments. Isolated ultrafiltration (ultrafiltration rate 13.6 ± 3.9 ml·kg−1·h−1) induced hypovolemia, whereas isovolemic dialysis did not (blood volume change −6.4 ± 2.2 vs. +1.3 ± 3.6%). Courses of blood pressure, heart rate, and tympanic temperature were comparable for both treatments. Global and regional myocardial perfusion did not change significantly during either isolated ultrafiltration or isovolemic dialysis and did not differ between treatments. LV ejection fraction and the wall motion score index did not change significantly during either treatment. Regional LV systolic dysfunction developed in one patient during isolated ultrafiltration and in three patients during isovolemic dialysis. In conclusion, global and regional myocardial perfusion was not compromised by 60 min of isolated ultrafiltration or isovolemic dialysis. Regional LV systolic dysfunction developed during isolated ultrafiltration and isovolemic dialysis, suggesting that, besides hypovolemia, dialysis-associated factors may be involved in the pathogenesis of hemodialysis-induced regional LV dysfunction.

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26

Ho, Chii-Dong, Jr-Wei Tu, Yih-Hang Chen e Thiam Leng Chew. "Two-Dimensional Theoretical Analysis and Experimental Study of Mass Transfer in a Hollow-Fiber Dialysis Module Coupled with Ultrafiltration Operations". Membranes 13, n. 8 (27 luglio 2023): 702. http://dx.doi.org/10.3390/membranes13080702.

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Abstract (sommario):

This research theoretically and experimentally develops a hollow-fiber dialysis module coupled with ultrafiltration operations by introducing a trans-membrane pressure during the membrane dialysis process, which can be applied to the waste metabolic end products in the human body for improving the dialysis efficiency. The solutes were transported by both diffusion and convection from the concentration driving-force gradient between retentate and dialysate phases across the membrane, compared to the traditional dialysis processes by diffusion only. A two-dimensional modeling of such a dialysis-and-ultrafiltration system in the hollow-fiber dialysis module was formulated and solved using the stream function coupled with the perturbation method to obtain the velocity distributions of retentate and dialysate phases, respectively. The purpose of the present work is to investigate the effect of ultrafiltration on the dialysis rate in the hollow-fiber dialyzer with ultrafiltration operations. A highest level of dialysis rate improvement up to about seven times (say 674.65% under Va=20 mL/min) was found in the module with ultrafiltration rate Vw=10 mL/min and membrane sieving coefficient θ=1, compared to that in the system without operating ultrafiltration. Considerable dialysis rate improvements on mass transfer were obtained by implementing a hollow-fiber dialysis-and-ultrafiltration system, instead of using the hollow-fiber dialyzer without ultrafiltration operation. The experimental runs were carried out under the same operating conditions for the hollow-fiber dialyzers of the two experimental runs with and without ultrafiltration operations for comparisons. A very reasonable prediction by the proposed mathematical model was observed.

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27

Zakharov, Ye V., A. L. Levit, D. A. Furazhkov, A. I. Svalov, T. L. Buldakova e K. B. Kazantsev. "Ultrafiltration as a method for regulating the volume balance during correction of transposition of great vessels in newborns". Patologiya krovoobrashcheniya i kardiokhirurgiya 18, n. 3 (10 ottobre 2015): 24. http://dx.doi.org/10.21688/1681-3472-2014-3-24-26.

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Abstract (sommario):

Correction of congenital heart disease in newborns under extracorporeal circulation is accompanied by fluid overload. To eliminate this pathological state, the method of ultrafiltration is commonly used. The paper presents a comparative analysis of two methods of ultrafiltration in the arterial switch procedure in 20 newborns with transposition of the great vessels. In group I (n = 10) we conducted conventional ultrafiltration during cardiopulmonary bypass; and in group II (n = 10), modified ultrafiltration after completing the cardiopulmonary bypass was used. The data obtained indicate that the inotropic support, the need in blood transfusion during the immediate follow-up and the mechanical ventilation duration were significantly lower during modified ultrafiltration as compared to conventional one.

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28

De Vecchi, Amedeo, Claudia Castelnovo, Luisella Guerra e Antonio Scalamogna. "Phosphatidylcholine Administration in Continuous Ambulatory Peritoneal Dialysis (CAPD) Patients with Reduced Ultrafiltration". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 9, n. 3 (luglio 1989): 207–10. http://dx.doi.org/10.1177/089686088900900312.

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Abstract (sommario):

To evaluate the possible role of oral phosphatidylcholine administration in improving peritoneal ultrafiltration sixteen continuous ambulatory peritoneal dialysis (CAPD) patients with a reduced ultrafiltration rate (less than 500 mL/4 h after a standard 3.86% glucose exchange) were studied. Three patients spontaneously stopped phosphatidylcholine due to gastric side effects. Three out of the remaining 13 patients showed a mild increase of standard ultrafiltration, which was not followed by any increase in daily dialysate output. No differences in glucose, sodium, potassium, urea and creatinine equilibration curves were seen. In conclusion, in our series oral phosphatidylcholine is not free of side effects, and its efficacy in improving ultrafiltration is scanty, with no clinical relevance in increasing daily ultrafiltration.

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29

Myers, Gerard J., Richard B. Leadon, Lance B. Mitchell e David B. Ross. "Simple modified ultrafiltration". Perfusion 15, n. 5 (settembre 2000): 447–52. http://dx.doi.org/10.1177/026765910001500507.

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Abstract (sommario):

After reviewing all available methods of modified ultrafiltration (MUF), an attempt was made to develop a more simplified approach to this beneficial method of post-bypass fluid removal by withdrawing blood from the right atrium and reinfusing into the aortic cannula (venoarterial). The simplicity of operation, ease of setup and analysis of hemoglobin, hematocrit, total proteins and colloid osmotic pressure, and fluid removed were examined in 12 consecutive neonatal and pediatric patients undergoing cardiac surgery. Results indicate that this simplified modified ultrafiltration (SMUF) is comparable to all other methods of MUF by achieving dramatic improvements in all parameters measured. In addition, SMUF provides the perfusionist with the ability to run conventional ultrafiltration throughout the bypass procedure, using this one circuit design. As well as finding the learning curve for SMUF to be very short, this method was found to be superior in its simplicity of operation, ease of setup, reduced risk of complications and acceptance by the surgeon and anesthetist.

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30

BODZEK, MICHAL. "Ultrafiltration PVC membranes". Polimery 30, n. 10 (ottobre 1985): 391–400. http://dx.doi.org/10.14314/polimery.1985.391.

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31

Akcicek, F. "Peritoneal ultrafiltration failure". Nephrology Dialysis Transplantation 16, suppl_6 (25 settembre 2001): 109–10. http://dx.doi.org/10.1093/ndt/16.suppl_6.109.

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32

Hubble, J., e J. D. Newman. "Alginate ultrafiltration membranes". Biotechnology Letters 7, n. 4 (aprile 1985): 273–76. http://dx.doi.org/10.1007/bf01042376.

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33

Ahner, N., D. Gottschlich, S. Narang, D. Roberts, S. Sharma e S. Ventura. "Piezoelectrically Assisted Ultrafiltration". Separation Science and Technology 28, n. 1-3 (gennaio 1993): 895–908. http://dx.doi.org/10.1080/01496399308019526.

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34

Grzenia, D. L., S. R. Wickramasinghe e J. O. Carlson. "Ultrafiltration of Parvovirus". Separation Science and Technology 42, n. 11 (luglio 2007): 2387–403. http://dx.doi.org/10.1080/01496390701477220.

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35

Dalgaard-Mikkelsen, Svend, e Sven Ancher Kvorning. "“Cellophane” for Ultrafiltration." Acta Pharmacologica et Toxicologica 5, n. 2 (13 marzo 2009): 173–78. http://dx.doi.org/10.1111/j.1600-0773.1949.tb03383.x.

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36

van Reis, Robert, Elizabeth M. Goodrich, Christine L. Yson, Leah N. Frautschy, Stephen Dzengeleski e Herb Lutz. "Linear scale ultrafiltration". Biotechnology and Bioengineering 55, n. 5 (5 settembre 1997): 737–46. http://dx.doi.org/10.1002/(sici)1097-0290(19970905)55:5<737::aid-bit4>3.0.co;2-c.

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37

Davis, Matthew, e Edward M. Darling. "Modified Ultrafiltration (MUF)". Journal of ExtraCorporeal Technology 27, n. 1 (marzo 1995): 56. http://dx.doi.org/10.1051/ject/199527156.

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38

Gienau, Tobias, Artjom Ehrmanntraut, Matthias Kraume e Sandra Rosenberger. "Influence of Ozone Treatment on Ultrafiltration Performance and Nutrient Flow in a Membrane Based Nutrient Recovery Process from Anaerobic Digestate". Membranes 10, n. 4 (4 aprile 2020): 64. http://dx.doi.org/10.3390/membranes10040064.

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Abstract (sommario):

Membrane filtration of biological suspensions is frequently limited by fouling. This mechanism is well understood for ultrafiltration of activated sludge in membrane bioreactors. A rather young application of ultrafiltration is the recovery of nutrients from anaerobic digestates, e.g., from agricultural biogas plants. A process chain of solid/liquid separation, ultrafiltration, and reverse osmoses separates the digestate into different products: an organic N-P-fertilizer (solid digestate), a recirculate (UF retentate), a liquid N-K-fertilizer (RO retentate) and water. Despite the preceding particle removal, high crossflow velocities are required in the ultrafiltration step to overcome fouling. This leads to high operation costs of the ultrafiltration step and often limits the economical application of the complete process chain. In this study, under-stoichiometric ozone treatment of the ultrafiltration feed stream is investigated. Ozone treatment reduced the biopolymer concentration and apparent viscosity of different digestate centrates. Permeabilities of centrate treated with ozone were higher than without ozone treatment. In a laboratory test rig and in a pilot plant operated at the site of two full scale biogas plants, ultrafiltration flux could be improved by 50–80% by ozonation. Nutrient concentrations in the fertilizer products were not affected by ozone treatment.

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39

Wang, Wei, Hui Ming Huang, De Ming Zhu, Hong Chen, Zhao Kang Su e Wei Xiang Ding. "Modified ultrafiltration in paediatric cardiopulmonary bypass". Perfusion 13, n. 5 (settembre 1998): 304–10. http://dx.doi.org/10.1177/026765919801300504.

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Abstract (sommario):

Cardiopulmonary bypass (CPB), a nonphysiological procedure, is associated with haemodilution and the inflammatory response, causing the accumulation of body water and organ dysfunction. The purpose of this study was to evaluate the efficacy of modified ultrafiltration. Forty paediatric patients undergoing cardiac operations were randomized into a control group and a modified ultrafiltration group. Blood cells, protein and cytokine concentrations were recorded for 24 h postoperatively. As the fluid was removed at 50 ml/min, both blood cells and protein were concentrated by modified ultrafiltration ( p < 0.001). The tumour necrosis factor (TNF)-α concentration was increased and interleukin-8 (IL-8) and endothelin (ET) concentrations were unaltered after ultrafiltration. After correction for albumin, TNF-α concentration changed little, and IL-8 and ET concentrations (36.75 ± 12.35, 42.89 ± 15.54) were decreased significantly (21.47 ± 13.87, 26.06 ± 12.54) after ultrafiltration. Modified ultrafiltration is an effective method for removing excess tissue fluid and concentrating blood after CPB. This technique can also filter out some cytokines.

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40

Wu, Buyun, Jian Sun, Si Liu, Xiangbao Yu, Yamei Zhu, Huijuan Mao e Changying Xing. "Relationship among Mortality of Patients with Acute Kidney Injury after Cardiac Surgery, Fluid Balance and Ultrafiltration of Renal Replacement Therapy: An Observational Study". Blood Purification 44, n. 1 (2017): 32–39. http://dx.doi.org/10.1159/000455063.

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Abstract (sommario):

Background/Aims: The study aimed to investigate the relationship among mortality of patients with cardiac surgery-associated acute kidney injury (CSA-AKI), fluid balance, and ultrafiltration of renal replacement therapy (RRT). Methods: From January 2009 to October 2015, hospitalized patients with CSA-AKI receiving continuous or prolonged intermittent RRT were screened. The effects of fluid balance and ultrafiltration of RRT on clinical outcome were analyzed. Results: The 30-day mortality of all the 63 patients in the study was 58.6%. Compared with the death group, the survival group had a significantly lower fluid balance, larger ultrafiltration volume, and similar ultrafiltration rate during the first 3 days of RRT. Multivariate Cox regression analysis revealed that positive fluid balance during the first day of RRT, cardiac function of grade IV, and higher Sequential Organ Failure Assessment score were independent risk factors of 30-day mortality. Conclusion: Fluid balance was more relevant to short-term prognosis of CSA-AKI-RRT patients than ultrafiltration volume or ultrafiltration rate.

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41

Zhao, Zhi Ling, Ying Lin e Shu Po Liu. "Study on Ultrafiltration Membrane Technology for Water Purification in Zhengzhou". Advanced Materials Research 287-290 (luglio 2011): 2156–60. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.2156.

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Abstract (sommario):

The ultrafiltration membrane technology which has been regarded as the water treatment technology for the human beings in the 21 century develops on the basis of reverse osmosis. The main function of the ultrafiltration membrane technology is to clear liquid, to reject solute concentration and solute fractionation, which can dislodge biological molecules, polymers and colloidal substances. The study introduces the situation of ultrafiltration membrane in treating drinking water in the fundament of the experiment of ultrafiltration membrane technology in Shiyuan water treatment plant in Zhengzhou,China.

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42

Hasanah, Hasanah, Iriani Setyaningsih e Uju Uju. "Harvesting and Separation Technique of Porphyridium cruentum Polysaccharide Using Ultrafiltration Membrane". Jurnal Pengolahan Hasil Perikanan Indonesia 19, n. 2 (31 agosto 2016): 110. http://dx.doi.org/10.17844/jphpi.v19i2.13110.

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Abstract (sommario):

Red microalga Porphyridium cruentum secreting polysaccharides into its medium culture. Harvesting and separation of polysaccharide of P. cruentum usually use centrifugation and in large scale needs high cost. The use of ultrafiltration membrane can be one of the alternatives for harvesting and separation of P. cruentum polysaccharide. This study aimed to determine the characteristic of membrane and permeat from harvesting and separation of P. cruentum polysaccharide using ultrafiltration. Research consisted of four stages : membrane characterization, cultivation of P. cruentum, harvesting using 0.05 μm ultrafiltration membrane, and polysaccharide separation using 0.01 μm ultrafiltration membrane. Characterization of membrane permeability and internal resistance on ultrafiltration 0.05 μm dan 0.01 μm were 137.32 L/m2hbar and 62.38 L/m2hbar and 0.01 barm2h/L and 0.02 barm2h/L, respectively. Harvesting using ultrafiltration 0.05 μm produced flux 131.37-94.75 L/m2h, biomass rejection 96% and permeate with OD (Optical Density) (0.01 ± 0.00), viscosity (2.4 ± 0.17 cp), pH (8 ± 0.00), and salinity (42.37 ± 0.11 ‰). Separation of polysaccharide using ultrafiltration 0.05 μm produced flux 58.11-51.53 L/m2h and permeate with viscosity (2.2 ± 0.30 cp), pH (7.8 ± 0.01), and salinity (38.73 ± 0.05 ‰). Ultrafiltration process decreased OD, viscosity, and salinity of permeate.

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43

Hasanah, Hasanah, Iriani Setyaningsih e Uju Uju. "Harvesting and Separation Technique of Porphyridium cruentum Polysaccharide Using Ultrafiltration Membrane". Jurnal Pengolahan Hasil Perikanan Indonesia 19, n. 2 (30 agosto 2016): 110. http://dx.doi.org/10.17844/jphpi.v19i2.13454.

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Abstract (sommario):

Red microalga Porphyridium cruentum secreting polysaccharides into its medium culture. Harvesting and separation of polysaccharide of P. cruentum usually use centrifugation and in large scale needs high cost. The use of ultrafiltration membrane can be one of the alternatives for harvesting and separation of P. cruentum polysaccharide. This study aimed to determine the characteristic of membrane and permeat from harvesting and separation of P. cruentum polysaccharide using ultrafiltration. Research consisted of four stages : membrane characterization, cultivation of P. cruentum, harvesting using 0.05 μm ultrafiltration membrane, and polysaccharide separation using 0.01 μm ultrafiltration membrane. Characterization of membrane permeability and internal resistance on ultrafiltration 0.05 μm dan 0.01 μm were 137.32 L/m2hbar and 62.38 L/m2hbar and 0.01 barm2h/L and 0.02 barm2h/L, respectively. Harvesting using ultrafiltration 0.05 μm produced flux 131.37-94.75 L/m2h, biomass rejection 96% and permeate with OD (Optical Density) (0.01 ± 0.00), viscosity (2.4 ± 0.17 cp), pH (8 ± 0.00), and salinity (42.37 ± 0.11 ‰). Separation of polysaccharide using ultrafiltration 0.05 μm produced flux 58.11-51.53 L/m2h and permeate with viscosity (2.2 ± 0.30 cp), pH (7.8 ± 0.01), and salinity (38.73 ± 0.05 ‰). Ultrafiltration process decreased OD, viscosity, and salinity of permeate.

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44

Rehman, Muneeb Ur, Tariq Rao, Naila Niaz, Shahid Nafees, Naseem Azad e Muhammad Shoaib Umar. "EFFECT OF MODIFIED ULTRAFILTRATION ON HEMODYNAMICS IN PEDIATRIC CARDIAC SURGERY AT ARMED FORCES INSTITUTE OF CARDIOLOGY/ NATIONAL INSTITUTE OF HEART DISEASES (AFIC/NIHD)". Pakistan Armed Forces Medical Journal 70, Suppl-4 (5 gennaio 2021): S757–61. http://dx.doi.org/10.51253/pafmj.v70isuppl-4.6019.

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Abstract (sommario):

Objective: To observe the effect of modified ultrafiltration on hemodynamics of pediatric patients. Study Design: A descriptive cross-sectional study. Place and Duration of Study: Pediatric Cardiac Surgery department, AFIC/NIHD Rawalpindi, from Jun 2019 to Dec 2019. Methodology: A total of 60 pediatric patients were included undergoing open-heart surgery with cardiopulmonary bypass, having age ≤6 years and weights ≤15kg. To assess hemodynamics parameters observed were pre modified ultrafiltration and post modified ultrafiltration measurements of haemoglobin level, systolic pressure, diastolic pressure, central venous pressure and the number of transfusions given after off-bypass. The data was entered and analyzed in SPSS-23. Results: The pre-operative mean Hb level of the 60 sampled patients was 12.08 ± 2.89 g/dl. The findings taken pre modified ultrafiltration and post modified ultrafiltration of haemoglobin level was (9.91 ± 0.91 g/dl and 13.09 ± 1.38 g/dl, p<0.05) after an average filtration of 370.83 ± 66.56 ml of the filtrate. The mean of systolic pressure was (61.3 ± 2.01 mmHg and 70.68 ± 1.76 mmHg, p<0.05), diastolic pressure was (49.95 ± 1.35 and 59.7 ± 6.85, p<0.005), Central Venous Pressure was (10.07 ± 1.18 and 9.9 ± 1.09, p>0.005) compared pre modified ultrafiltration and post modified ultrafiltration respectively. Conclusion: The study concluded that modified ultrafiltration has a significant impact on haemoglobin levels after bypass, decreases the allogenic transfusions and also improve the hemodynamics of the patient.

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45

Kwong, Mary B. L., George G. Wu, Helen Rodella, Lidia Brandes e Dimitrios G. Oreopoulos. "Effect of the Peritoneal Dialysate Buffer on UL TRafil Tration: Studies in Normal Rabbits". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 5, n. 3 (luglio 1985): 182–85. http://dx.doi.org/10.1177/089686088500500312.

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Abstract (sommario):

We studied an animal model to test the ultrafiltration capability of three different peritoneal dialysis solutions: Brand A, containing lactate and manufactured in Canada, Brand B, containing acetate and manufactured in U.S.A. and Brand C also containing acetate and manufactured in France. Solutions with 1.5 g0/o and 4.25 g0/o glucose concentrations were tested. We found no significant difference in the amount of ultrafiltration produced with the three brands when glucose concentration was 1.5 g0/o. However with glucose concentration of 4.25 g 0/o ultrafiltration was significantly lower with the Brand C-French acetate solution comparing to Brand A-Iactate solution. Brand B (acetate U.S.A.) solution produced ultrafiltration volumes that were between the other two and were not statistically significantly different from either Brand A (acetate) nor from Brand C (acetate). We concluded that the lower ultra-filtration produced by Brand C is not due to the presence of acetate buffer but to other factors operating alone or in combination with acetate. Adequate peritoneal ultrafiltration for fluid balance is one of the main factors in the success of continuous ambulatory peritoneal dialysis (CAPD). Ultrafiltration failure associated with the use of acetate buffered dialysis solution has been described frequently in France (I, 2, 3), but only occasionally in North American centres (4,5,6). It is still controversial whether acetate or some other element(s) is the factor responsible for the ultrafiltration failure observed in French patients. The first report of an international co-operative study revealed that ultrafiltration is significantly lower in patients using acetate, compared to those using lactate dialysis solutions (7). However, the second report of this study, which contained results from patients using a larger number of brands, showed that acetate may not be a responsible factor because there were patients using acetate-solutions manufactured outside France who had an ultrafiltration similar to that produced with lactate brands (8). Because of this, we chose to study in an animal model the ultrafiltration produced with solutions containing different buffers during acute experiments. This paper reports our findings.

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46

LaLone, Brian J., Mark W. Turrentine, Ko Bando, Chris C. Frederick, Michael T. Horner, Lon H. Richmond, Alex P. Bezruczko, Susan M. Morris, Deborah L. Frankenberg e John W. Brown. "Modified Ultrafiltration After Congenital Heart Surgery: A Veno–Venous Method Using a Dual-Lumen Hemodialysis Catheter". Journal of ExtraCorporeal Technology 32, n. 2 (giugno 2000): 95–103. http://dx.doi.org/10.1051/ject/2000322095.

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Abstract (sommario):

Perfusion practice surveys on modified ultrafiltration show most clinicians reporting the use of arterial to venous cannulation. With an arterial–venous (A–V) approach, the patient’s blood is accessed in a retrograde direction from the cardiopulmonary bypass aortic cannula, and the hemoconcentrated blood is returned to a catheter placed at a systemic venous return site. To avoid possible hazards of these arterial–venous techniques, we developed a veno–venous (V–V) modified ultrafiltration circuit and method that: (1) uses an 11.5 F dual-lumen hemodialysis catheter placed at a right atrial cannulation site for concomitant pickup and return of the patient’s blood; (2) places the ultrafiltration circuit within the cardioplegia delivery system, enabling the use of the heat exchanger/bubble trap features and also allowing hemoconcentration during cardiopulmonary bypass; and (3) uses an elevated, collapsible transfusion bag within the circuit as a holding reservoir for crystalloid-chased blood from the CPB circuit. The product literature and our lab testing of the hemodialysis catheter indicates adequate hemodynamics for modified ultrafiltration in children, and our clinical experience shows routine completion of the process in about 10–15 min (12.67 ± 1.73 mins; mean ± 1 SD, N = 9). Advantages of this V–V approach compared to A–V access include: (1) no potential aortic air entrainment at the aortic cannula purse-string suture; (2) modified ultrafiltration in patients regardless of aortic size or anatomy; and (3) avoidance of significant arterial to venous shunts during the performance of modified ultrafiltration. The elevated reservoir within the modified ultrafiltration circuit allows: (1) efficient pre- and/or postultrafiltration fluid chasing of blood from the main cardiopulmonary bypass circuit, thereby keeping it safely primed and allowing for the concentration of all circuit contents before and/or following the ultrafiltration method; (2) maintenance of desired patient filling pressures, temperature, and blood oxygen saturation within the ultrafiltration circuit by intermittent addition of warmed, oxygenated blood to the V–V modified ultrafiltration circuit.

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47

Armiyati, Yunie, Suharyo Hadisaputro, Shofa Chasani e Untung Sujianto. "High Ultrafiltration Increasing Intradialytic Blood Pressure on Hemodialysis Patients". South East Asia Nursing Research 3, n. 1 (28 marzo 2021): 8. http://dx.doi.org/10.26714/seanr.3.1.2021.8-15.

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Abstract (sommario):

The increase in blood pressure when the patient is undergoing hemodialysis is experienced by patients with intradialytic hypertension. This condition can be very dangerous for the patient, must be prevented and needs to be controlled. Prevention can be done by controlling variables that can affect intradialytic blood pressure, including ultrafiltration during hemodialysis. This study aims to analyze the relationship between ultrafiltration (ultrafiltration goal, ultrafiltration rate) and intradialytic blood pressure. This research was a descriptive-analytic study with a cross-sectional design, with 112 samples at two centres of dialysis in Semarang. Data were analyzed using the Spearman Rho. The finding obtained showed that ultrafiltration goal (UFG) and ultrafiltration rate (UFR) correlated with intradialytic blood pressure (systolic, diastolic and mean arterial pressure). The magnitude of UFG an associated with increase in intradialytic systolic (p=0,024; r=0,213), increase in intradialytic diastolic (p=0,007; r=0,252) and increase in mean arterial pressure (p=0,016; r=0,227). High UFR is associated with with increase in intradialytic systolic (p=0,037; r=0,211), increase in intradialytic diastolic (p=0,001; r=0,320) and increase in mean arterial pressure (p=0,034; r=0,200). Determination of ultrafiltration during hemodialysis must be done carefully and precisely to prevent an increase in intradialytic blood pressure.

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48

Wang, Hai Chao, e Xiao Ling Lei. "Problems and Prospects of Water-Supply by Ultrafiltration". Key Engineering Materials 727 (gennaio 2017): 837–40. http://dx.doi.org/10.4028/www.scientific.net/kem.727.837.

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Abstract (sommario):

General problems and prospects for water-supply using ultrafiltration technology are considered. The limits for application of this technology are indicated. The industrial water ultrafiltration plants appeared in the end of the XX century. Later in 2006 year the biggest in Europe plant purifying 250,000 m^3 of water per day by ultrafiltration was put into operation in Moscow. World experience shows that in large-scale station for purifying water the technology using combination of traditional methods with ozone treatment and sorption, and then membrane ultrafiltration is very useful.

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49

Stammers, Alfred H., John F. Morrow, Chad P. Brady, Joseph J. Deptula, Suzanne M. Huffman, Andrew S. Bonness, Timothy A. Galbraith e Anselmo Alonso. "Ultrafiltration of the Waste Plasma Effluent from Cardiopulmonary Bypass Circuit Contents Processed with a Cell-Washing Device". Journal of ExtraCorporeal Technology 28, n. 3 (settembre 1996): 134–39. http://dx.doi.org/10.1051/ject/1996283134.

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Abstract (sommario):

Blood conservation methods are commonly practiced throughout most hospitals that conduct cardiothoracic surgery. In an effort to reduce patients' exposure to homologous blood products and due to cost effectiveness of blood conservation techniques, this present study combines autotransfusion of the remaining blood in the extracorporeal circuit and ultrafiltration of the plasma effluent, and describes the resulting product. Seven patients, greater than 19 years of age, requiring cardiopulmonary bypass (CPB) were incorporated into this study. Exclusion criteria included age limitation. At termination of CPB, the remaining blood in the circuit was transferred to an autotransfusion machine and processed. Plasma (1054 ± 206 ml) effluent was collected directly from the centrifugal bowl and processed through a ultrafiltrator, with a constant flow rate and negative pressure, until the plasma effluent concentrated down to an end processed volume of approximately 150 ml. The following variables were either measured or calculated: plasma-concentrate volumes per three minute interval, inlet/outlet pressures of an ultrafiltrator, transmembrane pressure (TMP), plasma free hemoglobin, fibrinogen, total protein, and colloid osmotic pressure. The average ultrafiltrate volume taken off from the plasma effluent was 828 ± 237 ml, with an average ultrafiltrate volume of 115 ml in every three minute interval. The TMP did not change over the first 15 minutes of processing but became significantly elevated at the 18th minute interval and continued to increase and reach a maximum TMP of 286.5 ± 2.1 mmHg at the end of concentration. Fibrinogen levels increased from pre-concentration values of 118.2 ± 64 to 317 ± 177 mg/dl (p=.03) along with increases in plasma free hemoglobin from 97.7 ± 46 to 402.1 ± 180 mg/dl (p=.0002). The total protein concentration increased by over 330% from baseline values. Ultrafiltrating plasma effluent from autotransfused cell salvaged CPB circuit contents could prove beneficial, but further study is required to discover ways to separate unfavorable products, such as activated platelet-leukocyte products and reduced plasma free hemoglobin, and to lower heparin concentrations of the plasma-concentrate.

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Rusthoven, Esther, Raymond T. Krediet, Hans L. Willems, Leo A. Monnens e Cornelis H. Schröder. "Sodium Sieving in Children". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 25, n. 3_suppl (febbraio 2005): 141–42. http://dx.doi.org/10.1177/089686080502503s37.

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Abstract (sommario):

Sodium sieving is a consequence of dissociation between the amount of water and sodium transported over the peritoneal membrane. This dissociation occurs in the presence of aquaporin-mediated water transport. Sieving of sodium can be used as a rough measure for aquaporin-mediated water transport. Icodextrin contains glucose polymers, inducing ultrafiltration by colloid osmosis. Therefore, aquaporins play a minor role in ultrafiltration, which is confirmed by the absence of sodium sieving. Icodextrin is very suitable for the daytime dwell in children on a nightly intermittent peritoneal dialysis regimen. Ultrafiltration obtained with icodextrin is similar to ultrafiltration obtained with 3.86% glucose after a 12-hour dwell. When using icodextrin in children, it is also confirmed by the absence of sodium sieving that the aquaporins play a minor role in ultrafiltration.

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