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Graaff R, Eggersdorfer ML. Letter to the editor: "Clinical significance of micronutrient supplements in patients with coronavirus disease 2019: A comprehensive systematic review and meta-Analysis". Clin Nutr ESPEN 2023; 53:274. [PMID: 36657924 PMCID: PMC9727962 DOI: 10.1016/j.clnesp.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Affiliation(s)
| | - Manfred L. Eggersdorfer
- Professor at University Medical Centre Groningen, the Netherlands, Department of Internal Medicine, Münchwilerstrasse 20, 4332 Stein, Switzerland
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Zhu Y, Frank J, Riphagen IJ, Minović I, Vos MJ, Eggersdorfer ML, Navis GJ, Bakker SJL. Associations of 24 h urinary excretions of α- and γ-carboxyethyl hydroxychroman with plasma α- and γ-tocopherol and dietary vitamin E intake in older adults: the Lifelines-MINUTHE Study. Eur J Nutr 2022; 61:3755-3765. [PMID: 35718823 PMCID: PMC9464128 DOI: 10.1007/s00394-022-02918-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 05/19/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Urinary metabolites of vitamin E, i.e., α- and γ-carboxyethyl hydroxychroman (α- and γ-CEHC), have gained increasing attention and have been proposed as novel biomarkers of vitamin E intake and status. However, there are insufficient data on the relationship of plasma α-tocopherol and γ-tocopherol and dietary vitamin E intake with 24 h urinary excretions of α- and γ-CEHC. OBJECTIVES We aimed to (1) investigate the associations of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC with plasma α- and γ-tocopherol, respectively; (2) investigate the associations of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC with dietary vitamin E intake, and we hypothesize that 24 h urinary excretions of α- and γ-CEHC will better correlate with vitamin E intake than urinary α- and γ-CEHC/creatinine ratios. DESIGN 24 h Urine and plasma samples were collected from 1519 participants (60-75 years, male: 50%) included in the Lifelines-MINUTHE Study for the assessments of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC, and plasma α- and γ-tocopherol. Among those participants, dietary vitamin E intake data from 387 participants were available from an externally validated Flower-Food Frequency Questionnaire (FFQ). The associations of plasma α- and γ-tocopherol, dietary vitamin E intake, with urinary α- and γ-CEHC were assessed using multivariate linear regressions. RESULTS 24 h Urinary excretion of α-CEHC (median (IQR): 0.9 (0.3-2.4) µmol) was less than that of γ-CEHC (median (IQR): 1.5 (0.5-3.5) µmol). After adjustment for covariates, we found that 24 h urinary α-CEHC excretion and urinary α-CEHC/creatinine ratio were both positively associated with plasma α-tocopherol (std.beta: 0.06, p = 0.02; std.beta: 0.06, p = 0.01, respectively). Furthermore, the sum of 24 h urinary α- and γ-CEHC excretions was positively associated with dietary vitamin E intake (std.beta: 0.08; p = 0.03), whereas there was no relation between urinary α- and γ-CEHC/creatinine ratios and vitamin E intake. No association was observed neither between plasma α- and γ-tocopherol and dietary vitamin E intake, nor between urinary γ-CEHC and plasma γ-tocopherol. CONCLUSION Our study confirmed our hypothesis that 24 h urinary α- and γ-CEHC excretions would be a better marker for dietary vitamin E intake than urinary α- and γ-CEHC/creatinine ratios. Considering that both 24 h urinary α- and γ-CEHC excretions and α- and γ-CEHC/creatinine ratios were also associated with plasma α-tocopherol status, we suggest that 24 h urinary α- and γ-CEHC excretions could be used to assess overall vitamin E status.
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Affiliation(s)
- Yinjie Zhu
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Jan Frank
- Department of Food Biofunctionality (140B), Institute of Nutritional Sciences, University of Hohenheim, Stuttgart, Germany
| | - Ineke J Riphagen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Certe Medical Diagnostics and Advice, Medical Center Leeuwarden, Leeuwarden, The Netherlands
| | - Isidor Minović
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Michel J Vos
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Gerjan J Navis
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Stephan J L Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Riphagen IJ, Minović I, Groothof D, Post A, Eggersdorfer ML, Kootstra-Ros JE, de Borst MH, Navis G, Muskiet FAJ, Kema IP, Heiner-Fokkema MR, Bakker SJL. Methylmalonic acid, vitamin B12, renal function, and risk of all-cause mortality in the general population: results from the prospective Lifelines-MINUTHE study. BMC Med 2020; 18:380. [PMID: 33298054 PMCID: PMC7726887 DOI: 10.1186/s12916-020-01853-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/11/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Methylmalonic acid (MMA) is best known for its use as a functional marker of vitamin B12 deficiency. However, MMA concentrations not only depend on adequate vitamin B12 status, but also relate to renal function and endogenous production of propionic acid. Hence, we aimed to investigate to what extent variation in MMA levels is explained by vitamin B12 and eGFR and whether MMA levels are associated with mortality if vitamin B12 and eGFR are taken into account. METHODS A total of 1533 individuals (aged 60-75 years, 50% male) were included from the Lifelines Cohort and Biobank Study. Individuals were included between 2006 and 2013, and the total follow-up time was 8.5 years. RESULTS Median [IQR] age of the study population was 65 [62-69] years, 50% was male. At baseline, median MMA concentration was 170 [138-216] nmol/L, vitamin B12 290 [224-362] pmol/L, and eGFR 84 [74-91] mL/min/1.73 m2. Log2 vitamin B12, log2 eGFR, age, and sex were significantly associated with log2 MMA in multivariable linear regression analyses (model R2 = 0.22). After a total follow-up time of 8.5 years, 72 individuals had died. Log2 MMA levels were significantly associated with mortality (hazard ratio [HR] 1.67 [95% CI 1.25-2.22], P < 0.001). Moreover, we found a significant interaction between MMA and eGFR with respect to mortality (Pinteraction < 0.001). CONCLUSIONS Only 22% of variation in MMA levels was explained by vitamin B12, eGFR, age, and sex, indicating that a large part of variation in MMA levels is attributable to other factors (e.g., catabolism, dietary components, or gut microbial production). Higher MMA levels are associated with an increased risk for mortality, independent of vitamin B12, eGFR, and sex. This association was more pronounced in individuals with impaired renal function.
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Affiliation(s)
- Ineke J Riphagen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Isidor Minović
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
| | - Dion Groothof
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Adrian Post
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Jenny E Kootstra-Ros
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Gerjan Navis
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Frits A J Muskiet
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - M Rebecca Heiner-Fokkema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Stephan J L Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Zhu Y, Minović I, Dekker LH, Eggersdorfer ML, van Zon SK, Reijneveld SA, Kootstra-Ros JE, Kema IP, Bakker SJ, Navis GJ, Riphagen IJ. Vitamin Status and Diet in Elderly with Low and High Socioeconomic Status: The Lifelines-MINUTHE Study. Nutrients 2020; 12:nu12092659. [PMID: 32878227 PMCID: PMC7551314 DOI: 10.3390/nu12092659] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022] Open
Abstract
Socioeconomic health inequalities are an important global public health problem. However, it is not well known to what extent socioeconomic inequalities culminate in impaired vitamin status and whether this is mediated by diet. We, therefore, aimed to assess vitamin status in a population already at increased risk of micronutrient deficiency, i.e., elderly with high and low socioeconomic status (SES), and to investigate whether potential differences therein were mediated by diet quality. Vitamin status in 1605 individuals (60–75 years) from the Lifelines- Micronutrients and Health inequalities in Elderly (MINUTHE) Study was assessed by measuring folic acid and the vitamins B6, B12, D, A, E, and K. Multinomial logistic and linear regression analyses were applied to test the associations between SES and vitamin status. Mediation analysis was used to explore the interrelationship between SES, diet quality, and vitamin status. Low SES was associated with poorer status of vitamin B6, vitamin B12, and, notably, folic acid. Moreover, multivitamin deficiencies were more prevalent in the low SES group. Diet quality was found to mediate the associations of SES with folic acid (for 39.1%), vitamin B6 (for 37.1%), and vitamin B12 (for 37.2%). We conclude that low SES is a risk factor for a spectrum of vitamin deficiencies. Diet quality can partially explain the socioeconomic differences in vitamin status, suggesting that policymakers can mitigate socioeconomic inequality in nutritional status through improving diet quality.
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Affiliation(s)
- Yinjie Zhu
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (L.H.D.); (S.J.L.B.); (G.J.N.)
- Correspondence: ; Tel.: +31(0)62-665-2320
| | - Isidor Minović
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (I.M.); (J.E.K.-R.); (I.P.K.); (I.J.R.)
| | - Louise H. Dekker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (L.H.D.); (S.J.L.B.); (G.J.N.)
| | | | - Sander K.R. van Zon
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.K.R.v.Z.); (S.A.R.)
| | - Sijmen A. Reijneveld
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (S.K.R.v.Z.); (S.A.R.)
| | - Jenny E. Kootstra-Ros
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (I.M.); (J.E.K.-R.); (I.P.K.); (I.J.R.)
| | - Ido P. Kema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (I.M.); (J.E.K.-R.); (I.P.K.); (I.J.R.)
| | - Stephan J.L. Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (L.H.D.); (S.J.L.B.); (G.J.N.)
| | - Gerjan J. Navis
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (L.H.D.); (S.J.L.B.); (G.J.N.)
| | - Ineke J. Riphagen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands; (I.M.); (J.E.K.-R.); (I.P.K.); (I.J.R.)
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Sotomayor CG, Minović I, Eggersdorfer ML, Riphagen IJ, de Borst MH, Dekker LH, Nolte IM, Frank J, van Zon SK, Reijneveld SA, van der Molen JC, Vos MJ, Kootstra-Ros JE, Rodrigo R, Kema IP, Navis GJ, Bakker SJ. Duality of Tocopherol Isoforms and Novel Associations with Vitamins Involved in One-Carbon Metabolism: Results from an Elderly Sample of the LifeLines Cohort Study. Nutrients 2020; 12:nu12020580. [PMID: 32102191 PMCID: PMC7071362 DOI: 10.3390/nu12020580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/16/2022] Open
Abstract
Whether the affinity of serum vitamin E with total lipids hampers the appropriate assessment of its association with age-related risk factors has not been investigated in epidemiological studies. We aimed to compare linear regression-derived coefficients of the association of non-indexed and total lipids-indexed vitamin E isoforms with clinical and laboratory characteristics pertaining to the lipid, metabolic syndrome, and one-carbon metabolism biological domains. We studied 1429 elderly subjects (non-vitamin supplement users, 60-75 years old, with low and high socioeconomic status) from the population-based LifeLines Cohort and Biobank Study. We found that the associations of tocopherol isoforms with lipids were inverted in total lipids-indexed analyses, which may be indicative of overcorrection. Irrespective of the methods of standardization, we consistently found positive associations of α-tocopherol with vitamins of the one-carbon metabolism pathway and inverse associations with characteristics related to glucose metabolism. The associations of γ-tocopherol were often opposite to those of α-tocopherol. These data suggest that tocopherol isoforms and one-carbon metabolism are related, with beneficial and adverse associations for α-tocopherol and γ-tocopherol, respectively. Whether tocopherol isoforms, or their interplay, truly affect the one-carbon metabolism pathway remains to be further studied.
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Affiliation(s)
- Camilo G. Sotomayor
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
- Correspondence: ; Tel.: +31-050-361-0881
| | - Isidor Minović
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Manfred L. Eggersdorfer
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
| | - Ineke J. Riphagen
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Martin H. de Borst
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
| | - Louise H. Dekker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
| | - Ilja M. Nolte
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
| | - Jan Frank
- Institute of Nutritional Sciences, University of Hohenheim, 70599 Stuttgart, Germany;
| | - Sander K.R. van Zon
- Department of Health Sciences, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (S.A.R.)
| | - Sijmen A. Reijneveld
- Department of Health Sciences, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (S.A.R.)
| | - Jan C. van der Molen
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Michel J. Vos
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Jenny E. Kootstra-Ros
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Ramón Rodrigo
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago CP 8380453, Chile;
| | - Ido P. Kema
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (I.J.R.); (J.C.v.d.M.); (M.J.V.); (J.E.K.-R.); (I.P.K.)
| | - Gerjan J. Navis
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
| | - Stephan J.L. Bakker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (M.L.E.); (M.H.d.B.); (L.H.D.); (G.J.N.)
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Dekker LH, Vinke PC, Riphagen IJ, Minović I, Eggersdorfer ML, van den Heuvel EGHM, Schurgers LJ, Kema IP, Bakker SJL, Navis G. Cheese and Healthy Diet: Associations With Incident Cardio-Metabolic Diseases and All-Cause Mortality in the General Population. Front Nutr 2020; 6:185. [PMID: 31921878 PMCID: PMC6927928 DOI: 10.3389/fnut.2019.00185] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/22/2019] [Indexed: 01/07/2023] Open
Abstract
Background: Many countries have established Food-Based Dietary Guidelines (FBDG). For some foods, such as cheese, there is no consensus on whether or not to include them in these guidelines. Cheese may, however, be an excellent source of vitamin K2, which is a macronutrient with demonstrated positive results on cardiovascular-related outcomes. Aim: First, we assessed the role of cheese within the recently developed Lifelines Diet Score (LLDS), a score based on the Dutch FBDG 2015 in relation to incident cardio-metabolic diseases and all-cause mortality. Secondly, we assessed the association of cheese intake with desphospho-uncarboxylated matrix Gla protein (dp-ucMGP), a marker for functional vitamin K2 status, in a subset of the population. Methods: From the Lifelines cohort study, 122,653 adult participants were included to test the association between de LLDS and health outcomes. In a subset of 1,059 participants aged 60–75 years, dp-ucMGP levels were measured. Dietary intake was assessed using a 110-item Food Frequency Questionnaire. Logistic regression were applied, adjusted for relevant confounders. Results: Median cheese intake was 23.5 [12.6–40.6] g/day. We found a positive correlation between cheese intake and the LLDS (Spearman's rho = 0.024, p < 0.001). The LLDS in quintiles was associated with T2DM [OR (95% CI) Q5 (healthy diet) vs. Q1 (poor diet) = 0.54 (0.43–0.67)] and all-cause mortality [Q5 vs. Q1 = 0.62 (0.50–0.76)]. Inclusion of cheese did not alter these associations. Additionally, we found no significant association of total cheese intake with plasma dp-ucMGP levels. Conclusion: In this population-based cohort study, the inclusion of cheese in the LLDS did not change the inverse associations with incident cardio-metabolic diseases and all-cause mortality. Furthermore, we found no significant association of total cheese intake with plasma dp-ucMGP. The results suggest that cheese is a neutral food group that fits a healthy diet.
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Affiliation(s)
- Louise H Dekker
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Petra C Vinke
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Ineke J Riphagen
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Isidor Minović
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Manfred L Eggersdorfer
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | | | - Leon J Schurgers
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Stephan J L Bakker
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Gerjan Navis
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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7
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Sotomayor CG, Rodrigo R, Gomes-Neto AW, Gormaz JG, Pol RA, Minović I, Eggersdorfer ML, Vos M, Riphagen IJ, de Borst MH, Nolte IM, Berger SP, Navis GJ, Bakker SJL. Plasma versus Erythrocyte Vitamin E in Renal Transplant Recipients, and Duality of Tocopherol Species. Nutrients 2019; 11:E2821. [PMID: 31752254 PMCID: PMC6893692 DOI: 10.3390/nu11112821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 12/22/2022] Open
Abstract
Redox imbalance is an adverse on-going phenomenon in renal transplant recipients (RTR). Vitamin E has important antioxidant properties that counterbalance its deleterious effects. However, plasma vitamin E affinity with lipids challenges interpretation of its levels. To test the hypothesis that erythrocyte membranes represent a lipids-independent specimen to estimate vitamin E status, we performed a cross-sectional study in a cohort of adult RTR (n = 113) recruited in a university setting (2015-2018). We compared crude and total lipids-standardized linear regression-derived coefficients of plasma and erythrocyte tocopherol species in relation to clinical and laboratory parameters. Strongly positive associations of fasting lipids with plasma tocopherol became inverse, rather than absent, in total lipids-standardized analyses, indicating potential overadjustment. Whilst, no variables from the lipids domain were associated with the tocopherol species measured from erythrocyte specimens. In relation to inflammatory status and clinical parameters with antioxidant activity, we found associations in directions that are consistent with either beneficial or adverse effects concerning α- or γ-tocopherol, respectively. In conclusion, erythrocytes offer a lipids-independent alternative to estimate vitamin E status and investigate its relationship with parameters over other biological domains. In RTR, α- and γ-tocopherol may serve as biomarkers of relatively lower or higher vulnerability to oxidative stress and inflammation, noticeably in opposite directions.
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Affiliation(s)
- Camilo G. Sotomayor
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
| | - Ramón Rodrigo
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, CP 8380453 Santiago, Chile;
| | - António W. Gomes-Neto
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
| | | | - Robert A. Pol
- Division of Transplantation Surgery, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
| | - Isidor Minović
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (M.L.E.); (M.V.); (I.J.R.)
| | - Manfred L. Eggersdorfer
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (M.L.E.); (M.V.); (I.J.R.)
| | - Michel Vos
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (M.L.E.); (M.V.); (I.J.R.)
| | - Ineke J. Riphagen
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (I.M.); (M.L.E.); (M.V.); (I.J.R.)
| | - Martin H. de Borst
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
| | - Ilja M. Nolte
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
| | - Stefan P. Berger
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
| | - Gerjan J. Navis
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
| | - Stephan J. L. Bakker
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; (A.W.G.-N.); (M.H.d.B.); (S.P.B.); (G.J.N.); (S.J.L.B.)
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8
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Minović I, Eisenga MF, Riphagen IJ, van den Berg E, Kootstra-Ros J, Frenay ARS, van Goor H, Rimbach G, Esatbeyoglu T, Levy AP, Gaillard CAJM, Geleijnse JM, Eggersdorfer ML, Navis GJ, Kema IP, Bakker SJL. Author Correction: Circulating Haptoglobin and Metabolic Syndrome in Renal Transplant Recipients. Sci Rep 2018; 8:6501. [PMID: 29679027 PMCID: PMC5910402 DOI: 10.1038/s41598-018-24791-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
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Affiliation(s)
- Isidor Minović
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. .,Top Institute Food and Nutrition, Nieuwe Kanaal 9-A, 6709 PA, Wageningen, The Netherlands. .,Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
| | - Michele F Eisenga
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Ineke J Riphagen
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Else van den Berg
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Jenny Kootstra-Ros
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Anne-Roos S Frenay
- Department of Pathology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Harry van Goor
- Department of Pathology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Gerald Rimbach
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Tuba Esatbeyoglu
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Andy P Levy
- Faculty of Medicine, Technion Institute of Technology, Efron Street 1, Haifa, Israel
| | - Carlo A J M Gaillard
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Johanna M Geleijnse
- Division of Human Nutrition, Wageningen University, Droevendaalsesteeg 4, 6708 PB, Wageningen, The Netherlands
| | | | - Gerjan J Navis
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Stephan J L Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.,Top Institute Food and Nutrition, Nieuwe Kanaal 9-A, 6709 PA, Wageningen, The Netherlands
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9
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Post A, Minović I, van den Berg E, Eggersdorfer ML, Navis GJ, Geleijnse JM, Gans ROB, van Goor H, Struck J, Franssen CFM, Kema IP, Bakker SJL. Renal sulfate reabsorption in healthy individuals and renal transplant recipients. Physiol Rep 2018; 6:e13670. [PMID: 29671959 PMCID: PMC5907819 DOI: 10.14814/phy2.13670] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 02/28/2018] [Indexed: 11/24/2022] Open
Abstract
Inorganic sulfate is essential for normal cellular function and its homeostasis is primarily regulated in the kidneys. However, little is known about renal sulfate handling in humans and particularly in populations with impaired kidney function such as renal transplant recipients (RTR). Hence, we aimed to assess sulfate reabsorption in kidney donors and RTR. Plasma and urinary sulfate were determined in 671 RTR and in 251 kidney donors. Tubular sulfate reabsorption (TSR) was defined as filtered load minus sulfate excretion and fractional sulfate reabsorption (FSR) was defined as 1-fractional excretion. Linear regression analyses were employed to explore associations of FSR with baseline parameters and to identify the determinants of FSR in RTR. Compared to kidney donors, RTR had significantly lower TSR (15.2 [11.2-19.5] vs. 20.3 [16.7-26.3] μmol/min), and lower FSR (0.56 [0.48-0.64] vs. 0.64 [0.57-0.69]) (all P < 0.001). Kidney donation reduced both TSR and FSR by circa 50% and 25% respectively (both P < 0.001). In RTR and donors, both TSR and FSR associated positively with renal function. In RTR, FSR was independently associated with urinary thiosulfate (β = -0.18; P = 0.002), growth hormone (β = 0.12; P = 0.007), the intakes of alcohol (β = -0.14; P = 0.002), methionine (β = -0.34; P < 0.001), cysteine (β = -0.41; P < 0.001), and vitamin D (β = -0.14; P = 0.009). In conclusion, TSR and FSR are lower in RTR compared to kidney donors and both associated with renal function. Additionally, FSR is determined by various dietary and metabolic factors. Future research should determine the mechanisms behind sulfate handling in humans and the prognostic value of renal sulfate reabsorption in RTR.
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Affiliation(s)
- Adrian Post
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Isidor Minović
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
- Top Institute Food and NutritionWageningenThe Netherlands
- Department of Laboratory MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Else van den Berg
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | | | - Gerjan J. Navis
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | | | - Reinold O. B. Gans
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Harry van Goor
- Department of PathologyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | | | - Casper F. M. Franssen
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Ido P. Kema
- Department of Laboratory MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Stephan J. L. Bakker
- Department of Internal MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
- Top Institute Food and NutritionWageningenThe Netherlands
- Transplant Lines Food and Nutrition Biobank and Cohort StudyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
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10
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Minović I, Eisenga MF, Riphagen IJ, van den Berg E, Kootstra-Ros J, Frenay ARS, van Goor H, Rimbach G, Esatbeyoglu T, Levy AP, Gaillard CAJM, Geleijnse JM, Eggersdorfer ML, Navis GJ, Kema IP, Bakker SJL. Circulating Haptoglobin and Metabolic Syndrome in Renal Transplant Recipients. Sci Rep 2017; 7:14264. [PMID: 29079835 PMCID: PMC5660219 DOI: 10.1038/s41598-017-14302-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 10/09/2017] [Indexed: 12/17/2022] Open
Abstract
Haptoglobin (Hp) is an acute phase protein that has recently been linked to components of the metabolic syndrome (MetS). We aimed to evaluate Hp as marker of MetS, and to assess its association with long-term outcome in renal transplant recipients (RTR). We measured plasma Hp in a prospective cohort of 699 stable RTR and 149 healthy controls. Median plasma Hp concentration in RTR was 1.4 [interquartile range (IQR), 1.0–1.8] g/L, which was higher compared to 1.1 [0.9–1.4] g/L in controls (P < 0.001). Hp was independently associated with the MetS (β = 0.10) (P = 0.005). During follow-up of 5.4 [4.8–6.1] years, 150 (21%) recipients died, of whom 60 (9%) due to cardiovascular causes, and 83 (12%) RTR developed graft failure. High (≥2.0 g/L) and low (≤0.9 g/L) plasma Hp were associated with increased risk of mortality (HR’s 2.3 [1.3–4.1] and 1.9 [1.0–3.5], resp.), predominantly cardiovascular. The association of high Hp lost significance upon adjustment for inflammation markers (HR 1.5 [0.8–2.7]), while low Hp was independently associated with mortality (HR 2.2 [1.2–4.0]). Hp was not associated with graft failure (P = 0.49). In conclusion, plasma Hp is independently associated with MetS in RTR. Importantly, high and low Hp are associated with increased mortality risk, independent of MetS.
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Affiliation(s)
- Isidor Minović
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. .,Top Institute Food and Nutrition, Nieuwe Kanaal 9-A, 6709 PA, Wageningen, The Netherlands. .,Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
| | - Michele F Eisenga
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Ineke J Riphagen
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Else van den Berg
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Jenny Kootstra-Ros
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Anne-Roos S Frenay
- Department of Pathology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Harry van Goor
- Department of Pathology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Gerald Rimbach
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Tuba Esatbeyoglu
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Andy P Levy
- Faculty of Medicine, Technion Institute of Technology, Efron Street 1, Haifa, Israel
| | - Carlo A J M Gaillard
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Johanna M Geleijnse
- Division of Human Nutrition, Wageningen University, Droevendaalsesteeg 4, 6708 PB, Wageningen, The Netherlands
| | | | - Gerjan J Navis
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Stephan J L Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.,Top Institute Food and Nutrition, Nieuwe Kanaal 9-A, 6709 PA, Wageningen, The Netherlands
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Eggersdorfer ML, Zheng W, Nawar S, Mercandetti C, Ofner A, Leibacher I, Koehler S, Weitz DA. Tandem emulsification for high-throughput production of double emulsions. Lab Chip 2017; 17:936-942. [PMID: 28197593 DOI: 10.1039/c6lc01553k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Core-shell double emulsions produced using microfluidic methods with controlled structural parameters exhibit great potential in a wide range of applications, but the low production rate of microfluidic methods hinders the exploitation of the capabilities of microfluidics to produce double emulsions with well-defined features. A major obstacle towards the scaled-up production of core-shell double emulsions is the difficulty of achieving robust spatially controlled wettability in integrated microfluidic devices. Here, we use tandem emulsification, a two-step process with microfluidic devices, to scale up the production. With this method, single emulsions are generated in a first device and are re-injected directly into a second device to form uniform double emulsions. We demonstrate the application of tandem emulsification for scalable core-shell emulsion production with both integrated flow focusing and millipede devices and obtain emulsions of which over 90% are single-core monodisperse double emulsion drops. With both mechanisms, the shell thickness can be controlled, so that shells as thin as 3 μm are obtained for emulsions 50 μm in radius.
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Affiliation(s)
- M L Eggersdorfer
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - W Zheng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - S Nawar
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - C Mercandetti
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - A Ofner
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - I Leibacher
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - S Koehler
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
| | - D A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA. and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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12
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Abstract
The ballistic agglomeration of polydisperse particles is investigated by an event-driven (ED) method and compared to the coagulation of spherical particles and agglomerates consisting of monodisperse primary particles (PPs). It is shown for the first time to our knowledge that increasing the width or polydispersity of the PP size distribution initially accelerates the coagulation rate of their agglomerates but delays the attainment of their asymptotic fractal-like structure and self-preserving size distribution (SPSD) without altering them, provided that sufficiently large numbers of PPs are employed. For example, the standard asymptotic mass fractal dimension, Df, of 1.91 is attained when clusters are formed containing, on average, about 15 monodisperse PPs, consistent with fractal theory and the literature. In contrast, when polydisperse PPs with a geometric standard deviation of 3 are employed, about 500 PPs are needed to attain that Df. Even though the same asymptotic Df and mass-mobility exponent, Dfm, are attained regardless of PP polydispersity, the asymptotic prefactors or lacunarities of Df and Dfm increase with PP polydispersity. For monodisperse PPs, the average agglomerate radius of gyration, rg, becomes larger than the mobility radius, rm, when agglomerates consist of more than 15 PPs. Increasing PP polydispersity increases that number of PPs similarly to the above for the attainment of the asymptotic Df or Dfm. The agglomeration kinetics are quantified by the overall collision frequency function. When the SPSD is attained, the collision frequency is independent of PP polydispersity. Accounting for the SPSD polydispersity in the overall agglomerate collision frequency is in good agreement with that frequency from detailed ED simulations once the SPSD is reached. Most importantly, the coagulation of agglomerates is described well by a monodisperse model for agglomerate and PP sizes, whereas the detailed agglomerate size distribution can be obtained by scaling the average agglomerate size to the SPSD.
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Affiliation(s)
- E Goudeli
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, CH-8092 Zürich, Switzerland
| | - M L Eggersdorfer
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, CH-8092 Zürich, Switzerland
| | - S E Pratsinis
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, CH-8092 Zürich, Switzerland
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13
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Eggersdorfer ML, Gröhn AJ, Sorensen CM, McMurry PH, Pratsinis SE. Mass-mobility characterization of flame-made ZrO2 aerosols: primary particle diameter and extent of aggregation. J Colloid Interface Sci 2012; 387:12-23. [PMID: 22959835 DOI: 10.1016/j.jcis.2012.07.078] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 06/14/2012] [Accepted: 07/14/2012] [Indexed: 11/26/2022]
Abstract
Gas-borne nanoparticles undergoing coagulation and sintering form irregular or fractal-like structures affecting their transport, light scattering, effective surface area, and density. Here, zirconia (ZrO(2)) nanoparticles are generated by scalable spray combustion, and their mobility diameter and mass are obtained nearly in situ by differential mobility analyzer (DMA) and aerosol particle mass (APM) measurements. Using these data, the density of ZrO(2) and a power law between mobility and primary particle diameters, the structure of fractal-like particles is determined (mass-mobility exponent, prefactor and average number, and surface area mean diameter of primary particles, d(va)). The d(va) determined by DMA-APM measurements and this power law is in good agreement with the d(va) obtained by ex situ nitrogen adsorption and microscopic analysis. Using this combination of measurements and above power law, the effect of flame spray process parameters (e.g., precursor solution and oxygen flow rate as well as zirconium concentration) on fractal-like particle structure characteristics is investigated in detail. This reveals that predominantly agglomerates (physically-bonded particles) and aggregates (chemically- or sinter-bonded particles) of nanoparticles are formed at low and high particle concentrations, respectively.
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Affiliation(s)
- M L Eggersdorfer
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zürich, Switzerland
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Eggersdorfer ML, Kadau D, Herrmann HJ, Pratsinis SE. Fragmentation and restructuring of soft-agglomerates under shear. J Colloid Interface Sci 2009; 342:261-8. [PMID: 19948345 DOI: 10.1016/j.jcis.2009.10.062] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 10/23/2009] [Accepted: 10/24/2009] [Indexed: 11/25/2022]
Abstract
Soft-agglomerate restructuring, break-up (or fragmentation) and relaxation are studied in a simple shear flow by a discrete element method (DEM). The agglomerates, held together by van der Waals forces, rotate in the shear flow and are stretched into nearly linear structures (fractal dimension approaches unity) until they fracture at their weakest point resulting in lognormally-shaped fragment size distributions asymptotically. Individual fragments relax in the flow towards more compact agglomerates than the parent ones. The evolution of the average number of particles per fragment is described by generalized scaling laws between shear rate, onset (time-lag) of fragmentation, asymptotic fragment mass and size consistent with experimental and theoretical studies in the literature. The initial effective fractal dimension of the agglomerates influences the final one of the fragments.
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Affiliation(s)
- M L Eggersdorfer
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zürich, Switzerland.
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Eggersdorfer ML, Kokke WCMC, Crandell CW, Hochlowski JE, Djerassi C. Sterols in marine invertebrates. 32. Isolation of 3.beta.-(hydroxymethyl)-A-nor-5.alpha.-cholest-15-ene, the first naturally occurring sterol with a 15-16 double bond. J Org Chem 2002. [DOI: 10.1021/jo00148a015] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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