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Swackhamer C, Bedane T, Keppler S, Poltorak A, Cheung K, Awais N, Marra F, Bornhorst GM. Development and analysis of a multi-module peristaltic simulator for gastrointestinal research. Food Res Int 2023; 170:112877. [PMID: 37316038 DOI: 10.1016/j.foodres.2023.112877] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/06/2023] [Accepted: 04/20/2023] [Indexed: 06/16/2023]
Abstract
Many existing in vitro digestion systems do not accurately represent the peristaltic contractions of the gastrointestinal system; most of the systems that have physiologically-relevant peristaltic contractions have low throughput and can only test one sample at a time. A device has been developed that provides simulated peristaltic contractions for up to 12 digestion modules simultaneously using rollers of varying width to modulate the dynamics of the peristaltic motion. The force applied to a simulated food bolus varied from 2.61 ± 0.03 N to 4.51 ± 0.16 N (p < 0.05) depending on roller width. Video analysis showed that the degree of occlusion of the digestion module varied from 72.1 ± 0.4% to 84.6 ± 1.2% (p < 0.05). A multiphysics, computational fluid dynamics model was created to understand the fluid flow. The fluid flow was also examined experimentally using video analysis of tracer particles. The model-predicted maximum fluid velocity in the peristaltic simulator incorporating the thin rollers was 0.016 m/s, and the corresponding value measured using tracer particles was 0.015 m/s. The occlusion, pressure, and fluid velocity in the new peristaltic simulator fell within physiologically representative ranges. Although no in vitro device perfectly recreates the conditions of the gastrointestinal system, this novel device is a flexible platform for future gastrointestinal research and could allow for high-throughput screening of food materials for health-promoting properties under conditions representative of human gastrointestinal motility.
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Affiliation(s)
- Clay Swackhamer
- Department of Biological and Agricultural Engineering, University of California, Davis, USA
| | - Tesfaye Bedane
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Silvia Keppler
- Department of Biological and Agricultural Engineering, University of California, Davis, USA
| | - Adam Poltorak
- Department of Biological and Agricultural Engineering, University of California, Davis, USA
| | - Kyle Cheung
- Department of Biological and Agricultural Engineering, University of California, Davis, USA
| | - Nashea Awais
- Department of Biological and Agricultural Engineering, University of California, Davis, USA
| | - Francesco Marra
- Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, 84084 Fisciano, Italy
| | - Gail M Bornhorst
- Department of Biological and Agricultural Engineering, University of California, Davis, USA; Riddet Institute, Palmerston North, New Zealand.
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Keppler S, Huynh K, Reinhold D, Bornhorst GM. Fate of Phytometabolites of Antibiotics during In Vitro Digestion and Implications for Human Health. J Agric Food Chem 2021; 69:12598-12607. [PMID: 34665628 DOI: 10.1021/acs.jafc.1c03934] [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] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Antibiotics are released into the environment as their global consumption increases. Uptake, accumulation, and metabolism of antibiotics by food crops is an emerging health concern as the associated risks of consuming food crops containing antibiotics are still largely unknown. This study investigated the fate of sulfamethazine, sulfamethoxazole, and their phytometabolites during in vitro digestion of the model plantArabidopsis thaliana. The amounts of parent antibiotics released during in vitro digestion were 4-5 times higher than those quantified in plant tissues prior to digestion, which was attributed to back transformation of the phytometabolites into the parent aglycones. These findings demonstrated that overlooking the proportions of phytometabolites in recent health risk assessment studies would considerably underestimate the realistic human exposure through consumption of contaminated food crops. New risk assessment frameworks are necessary to include these critical factors for comprehensively addressing human exposure to emerging contaminants through food chains.
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Affiliation(s)
- Silvia Keppler
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, California 95616, United States
| | - Khang Huynh
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Dawn Reinhold
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Gail M Bornhorst
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, California 95616, United States
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Keppler S, Mannara G, Marra F, Bornhorst GM. Characterization of raft-forming alginate suspensions formed in HCl or model food systems at varying pH levels to better simulate gastric postprandial conditions. Drug Dev Ind Pharm 2021; 47:1079-1089. [PMID: 34254865 DOI: 10.1080/03639045.2021.1954940] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Elucidate properties of raft-forming alginates in vitro with varying composition, a system in which the raft was formed (HCl solution; tomato soup; protein-rich beverage), and pH levels for a more accurate representation of postprandial gastric conditions. SIGNIFICANCE Knowledge of the impact of the food system and pH on properties of raft-forming alginates may aid in formulation optimization. Recommendations may be made on food that is consumed prior to their consumption to optimize efficacy as a therapeutic agent. METHODS Dispersions of sodium alginate, calcium carbonate, and sodium bicarbonate were prepared with levels similar to commercial formulations. Rafts were formed in HCl solution, tomato soup, and a protein-rich beverage at pH 1-4 to assess raft properties. RESULTS Significant differences (p < 0.05) in raft mass, strength, resilience, and ability to buffer acid were observed depending on the system in which the rafts were formed. The highest mass was obtained in tomato soup (48.5 ± 9.8 g) compared to the protein-rich beverage and HCl solution (32.5 ± 4.5 g and 23.4 ± 4.8 g, respectively) at pH 1. Rafts formed in the protein-rich beverage exhibited the highest strength. Rafts formed in both food systems had a greater ability to buffer added acid compared to rafts formed in HCl solution. CONCLUSIONS In vitro testing of raft forming alginates in HCl solution at low pH may not be sufficient to describe in vivo events, as a strong matrix effect was observed when rafts were formed in model meal systems at representative postprandial pH levels.
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Affiliation(s)
- S Keppler
- Department of Biological and Agricultural Engineering, University of California Davis, Davis, CA, USA
| | - G Mannara
- Department of Industrial Engineering, University of Salerno, Fisciano SA, Italy
| | - F Marra
- Department of Industrial Engineering, University of Salerno, Fisciano SA, Italy
| | - G M Bornhorst
- Department of Biological and Agricultural Engineering, University of California Davis, Davis, CA, USA
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Tamer I, Hornung M, Lukas L, Hellwing M, Keppler S, Van Hull R, Hein J, Zepf M, Kaluza MC. Characterization and application of nonlinear plastic materials for post-CPA pulse compression. Opt Lett 2020; 45:6575-6578. [PMID: 33325843 DOI: 10.1364/ol.409637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/15/2020] [Indexed: 06/12/2023]
Abstract
We demonstrate the three-fold post-chirped-pulse-amplification (post-CPA) pulse compression of a high peak power laser pulse using allyl diglycol carbonate (CR39), which was selected as the optimal material for near-field self-phase modulation out of a set of various nonlinear plastic materials, each characterized with respect to its nonlinear refractive index and optical transmission. The investigated materials could be applied for further pulse compression at high peak powers, as well as for gain narrowing compensation within millijoule-class amplifiers. The post-CPA pulse compression technique was tested directly after the first CPA stage within the POLARIS laser system, with the compact setup containing a single 1 mm thick plastic sample and a chirped mirror pair, which enabled a substantial shortening of the compressed pulse duration and, hence, a significant increase in the laser peak power without any additional modifications to the existing CPA chain.
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Mennah-Govela YA, Keppler S, Januzzi-Guerreiro F, Follador-Lemos C, Vilpont K, Bornhorst GM. Acid and Moisture Uptake into Red Beets during in Vitro Gastric Digestion as Influenced by Gastric pH. FOOD BIOPHYS 2020. [DOI: 10.1007/s11483-019-09623-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Keppler S, O'Meara S, Bakalis S, Fryer P, Bornhorst G. Characterization of individual particle movement during in vitro gastric digestion in the Human Gastric Simulator (HGS). J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2019.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Tan J, Martini S, Wang Y, Kong F, Hartel R, Barbosa-Cánovas G, Vardhanabhuti B, Bornhorst G, Keppler S, Joyner H. Interlaboratory Measurement of Rheological Properties of Tomato Salad Dressing. J Food Sci 2019; 84:3204-3212. [PMID: 31589341 DOI: 10.1111/1750-3841.14828] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/24/2019] [Accepted: 09/04/2019] [Indexed: 11/30/2022]
Abstract
Rheological properties of food materials are important as they influence food texture, processing properties, and stability. Rotational rheometry has been widely used for measuring rheological properties. However, the measurements obtained using different geometries and rheometers are generally not compared for precision and accuracy, so it is difficult to compare data across different studies. In this study, nine rheometers from seven laboratories were used to measure the viscosity and viscoelastic properties of a commercial salad dressing. The measurements were obtained at three temperatures (8, 25, and 60 °C) using different diameter parallel plates (20, 40, 50, and 60 mm). Generally, the viscosity measurements among rheometers differed significantly ( P < 0.05 ). For larger geometry diameter (40, 50, and 60 mm) and at lower temperatures (8 °C), viscosity measurements at lower shear rate (0.01, 0.1, and 1.0 s-1 ) were significantly different. Rheometer brand significantly affected storage modulus only at low (0.01%) and high levels (10% and 100%) of strain. Temperature was an influencing factor on viscoelastic behaviors only at high strain (>10%). Storage moduli values obtained by frequency sweeps were not affected by rheometer or plate diameter. Overall, rheometer, geometry, and temperature can influence rheological measurements and care should be taken when comparing data across laboratories or published works. Higher shear rates (≥10 s-1 ) and moderate strains (0.1% to 10%) generally provide more repeatable data among different laboratories. PRACTICAL APPLICATION: This study provides information on what factors may potentially influence rheological measurements conducted across different laboratories. It is useful for rheometer users who want to compare their experimental data to published data or compare two sets of published data. It is better to compare data collected at shear rates 10 s-1 and strains between 0.1% and 1.0%.
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Affiliation(s)
- Juzhong Tan
- Dept. of Food Science, Rutgers, The State Univ. of New Jersey, New Brunswick, NJ, 30605, U.S.A
| | - Silvana Martini
- Dept. of Nutrition, Dietetics, and Food Science, Utah State Univ., Logan, UT, 84322, U.S.A
| | - Ye Wang
- Dept. of Statistics, Univ. of Georgia, Athens, GA, 30602, U.S.A
| | - Fanbin Kong
- Dept. of Food Science and Technology, Univ. of Georgia, Athens, GA, 30602, U.S.A
| | - Richard Hartel
- Dept. of Food Science, Univ. of Wisconsin-Madison, Madison, WI, 53706, U.S.A
| | | | | | - Gail Bornhorst
- Dept. of Food Science and Technology, Univ. of California-Davis, Davis, CA, 95616, U.S.A
| | - Silvia Keppler
- Dept. of Food Science and Technology, Univ. of California-Davis, Davis, CA, 95616, U.S.A
| | - Helen Joyner
- School of Food Science, Univ. of Idaho, Moscow, ID, 83844, U.S.A
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Keppler S, Bakalis S, Leadley C, Sahi S, Fryer P. Evaluation of dry heat treatment of soft wheat flour for the production of high ratio cakes. Food Res Int 2018; 107:360-370. [DOI: 10.1016/j.foodres.2018.02.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/28/2018] [Accepted: 02/13/2018] [Indexed: 11/26/2022]
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Keppler S, Bakalis S, Leadley C, Fryer P. A systematic study of the residence time of flour in a vibrating apparatus used for thermal processing. INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2015.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
The introduction of Swiss DRG in 2012 offers women in Switzerland free choice of hospital. The objective of this study was to identify decision factors affecting the choice of hospital birth in Switzerland and to rate the degree of utilization of information sources. In seven Swiss hospitals, located in the German-speaking part of Switzerland, women in childbed were interviewed in writing. When choosing a hospital, factors rated by women as important were professional competence, good medical care, good obstetric competence, good nursing care and a neat and clean atmosphere. Important sources of information are recommendations of friends, own experience gained during previous hospital stays, the specialist, family, and the hospital homepage. Information meetings for pregnant women are essential for hospitals because they encourage women's decision to use the hospital. Web presence of the hospital and a good relationship with the specialists or family doctors are important, but experience of friends, family or one's own experience with stay at the hospital play a more important role.
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Affiliation(s)
| | - S Keppler
- European Education Group AG, Business Development, Eschen, Liechtenstein
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Keppler S, Hornung M, Bödefeld R, Sävert A, Liebetrau H, Hein J, Kaluza MC. Full characterization of the amplified spontaneous emission from a diode-pumped high-power laser system. Opt Express 2014; 22:11228-11235. [PMID: 24921820 DOI: 10.1364/oe.22.011228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present the first complete temporal and spatial characterization of the amplified spontaneous emission (ASE) of laser radiation generated by a diode-pumped high-power laser system. The ASE of the different amplifiers was measured independently from the main pulse and was characterized within a time window of -10ms ≤ t ≤ 10ms and an accuracy of up to 15fs around the main pulse. Furthermore, the focusability and the energy of the ASE from each amplifier was measured after recompression. Using our analysis method, the laser components, which need to be optimized for a further improvement of the laser contrast, can be identified. This will be essential for laser-matter interaction experiments requiring a minimized ASE intensity or fluence.
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Keppler S, Hornung M, Bödefeld R, Kahle M, Hein J, Kaluza MC. All-reflective, highly accurate polarization rotator for high-power short-pulse laser systems. Opt Express 2012; 20:20742-20747. [PMID: 23037123 DOI: 10.1364/oe.20.020742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present the setup of a polarization rotating device and its adaption for high-power short-pulse laser systems. Compared to conventional halfwave plates, the all-reflective principle using three zero-phase shift mirrors provides a higher accuracy and a higher damage threshold. Since plan-parallel plates, e.g. these halfwave plates, generate postpulses, which could lead to the generation of prepulses during the subsequent laser chain, the presented device avoids parasitic pulses and is therefore the preferable alternative for high-contrast applications. Moreover the device is easily scalable for large beam diameters and its spectral reflectivity can be adjusted by an appropriate mirror coating to be well suited for ultra-short laser pulses.
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Affiliation(s)
- S Keppler
- Institute of Optics and Quantum Electronics, FSU Jena, Max-Wien Platz 1, 07743 Jena, Germany.
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Klewitz J, Sieme H, Probst J, Baackmann C, Keppler S, Ortgies F, Heberling A, Strübing C, Heutelbeck A, Börgel C. „Plugged ampullae“ – a case report of azoospermia in the stallion. PFERDEHEILKUNDE 2012. [DOI: 10.21836/pem20120103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bertelsmann H, Keppler S, Höltershinken M, Bollwein H, Behne D, Alber D, Bukalis G, Kyriakopoulos A, Sieme H. Selenium in blood, semen, seminal plasma and spermatozoa of stallions and its relationship to sperm quality. Reprod Fertil Dev 2010; 22:886-91. [DOI: 10.1071/rd10032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 03/22/2010] [Indexed: 11/23/2022] Open
Abstract
The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples each). The pregnancy rate per oestrus cycle (PRC) served as an estimation of fertility. An adverse effect on stallion fertility caused by low dietary selenium intake was excluded, as all stallions had sufficient selenium levels in their blood. Interestingly, no significant correlations (P > 0.05) between the selenium level in blood and the selenium level in seminal plasma or spermatozoa were found, suggesting that the selenium level in blood is no indicator of an adequate selenium supply for spermatogenesis. The selenium level in spermatozoa (nmol billion–1) was correlated with PMI, PMS and PAS (r = 0.40, r = 0.31 and r = –0.42, respectively; P ≤ 0.05), and the selenium concentration in spermatozoa (nmol g–1) was correlated with PRC (r = 0.40, P < 0.03). The results of the present study show that the determination of an adequate selenium status for the male equine reproduction requires the analysis of selenium in spermatozoa. Furthermore, selenium is associated with improved sperm quality and fertility in the stallion.
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Keppler S, Shores J. Health educators design complete CPR program. Crossreference 1975; 5:3-4. [PMID: 10237326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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