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Schuler MJ, Becker D, Mueller M, Bautista Borrego L, Mancina L, Huwyler F, Binz J, Hagedorn C, Schär B, Gygax E, Weisskopf M, Sousa Da Silva RX, Antunes Crisóstomo JM, Dutkowski P, Rudolf von Rohr P, Clavien PA, Tibbitt MW, Eshmuminov D, Hefti M. Observations and findings during the development of a subnormothermic/normothermic long-term ex vivo liver perfusion machine. Artif Organs 2023; 47:317-329. [PMID: 36106378 DOI: 10.1111/aor.14403] [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: 04/03/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Ex situliver machine perfusion at subnormothermic/normothermic temperature isincreasingly applied in the field of transplantation to store and evaluateorgans on the machine prior transplantation. Currently, various perfusionconcepts are in clinical and preclinical applications. Over the last 6 years ina multidisciplinary team, a novel blood based perfusion technology wasdeveloped to keep a liver alive and metabolically active outside of the bodyfor at least one week. METHODS Within thismanuscript, we present and compare three scenarios (Group 1, 2 and 3) we werefacing during our research and development (R&D) process, mainly linked tothe measurement of free hemoglobin and lactate in the blood based perfusate. Apartfrom their proven value in liver viability assessment (ex situ), these twoparameters are also helpful in R&D of a long-term liver perfusion machine and moreover supportive in the biomedical engineering process. RESULTS Group 1 ("good" liver on the perfusion machine) represents the best liver clearance capacity for lactate and free hemoglobin wehave observed. In contrast to Group 2 ("poor" liver on the perfusion machine), that has shown the worst clearance capacity for free hemoglobin. Astonishingly,also for Group 2, lactate is cleared till the first day of perfusion andafterwards, rising lactate values are detected due to the poor quality of theliver. These two perfusate parametersclearly highlight the impact of the organ quality/viability on the perfusion process. Whereas Group 3 is a perfusion utilizing a blood loop only (without a liver). CONCLUSION Knowing the feasible ranges (upper- and lower bound) and the courseover time of free hemoglobin and lactate is helpful to evaluate the quality ofthe organ perfusion itself and the maturity of the developed perfusion device. Freehemoglobin in the perfusate is linked to the rate of hemolysis that indicates how optimizing (gentle blood handling, minimizing hemolysis) the perfusion machine actually is. Generally, a reduced lactate clearancecapacity can be an indication for technical problems linked to the blood supplyof the liver and therefore helps to monitor the perfusion experiments.Moreover, the possibility is given to compare, evaluate and optimize developed liverperfusion systems based on the given ranges for these two parameters. Otherresearch groups can compare/quantify their perfusate (blood) parameters withthe ones in this manuscript. The presented data, findings and recommendations willfinally support other researchers in developing their own perfusion machine ormodifying commercially availableperfusion devices according to their needs.
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Affiliation(s)
- Martin J Schuler
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Matteo Mueller
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Leandro Mancina
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Florian Huwyler
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Jonas Binz
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Catherine Hagedorn
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Beatrice Schär
- Entwicklung biomedizinische Anwendungen, Securecell AG, Urdorf, Switzerland
| | - Erich Gygax
- Forschung und Entwicklung, Fumedica AG, Muri, Switzerland
| | - Miriam Weisskopf
- Center of Surgical Research, University Hospital Zürich, University of Zürich, Zurich, Switzerland
| | - Richard Xavier Sousa Da Silva
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | | | - Philipp Dutkowski
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Pierre-Alain Clavien
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Mark W Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Dilmurodjon Eshmuminov
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
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2
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Clavien PA, Dutkowski P, Mueller M, Eshmuminov D, Bautista Borrego L, Weber A, Muellhaupt B, Sousa Da Silva RX, Burg BR, Rudolf von Rohr P, Schuler MJ, Becker D, Hefti M, Tibbitt MW. Transplantation of a human liver following 3 days of ex situ normothermic preservation. Nat Biotechnol 2022; 40:1610-1616. [PMID: 35641829 DOI: 10.1038/s41587-022-01354-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 05/09/2022] [Indexed: 01/13/2023]
Abstract
Current organ preservation methods provide a narrow window (usually <12 hours) to assess, transport and implant donor grafts for human transplantation. Here we report the transplantation of a human liver discarded by all centers, which could be preserved for several days using ex situ normothermic machine perfusion. The transplanted liver exhibited normal function, with minimal reperfusion injury and the need for only a minimal immunosuppressive regimen. The patient rapidly recovered a normal quality of life without any signs of liver damage, such as rejection or injury to the bile ducts, according to a 1-year follow up. This inaugural clinical success opens new horizons in clinical research and promises an extended time window of up to 10 days for assessment of viability of donor organs as well as converting an urgent and highly demanding surgery into an elective procedure.
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Affiliation(s)
- Pierre-Alain Clavien
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland. .,Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.
| | - Philipp Dutkowski
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland
| | - Matteo Mueller
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Dilmurodjon Eshmuminov
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Achim Weber
- Department of Pathology and Molecular Pathology, and Institute of Molecular Cancer Research, University of Zurich and University Hospital Zurich, Zurich, Switzerland
| | - Beat Muellhaupt
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Richard X Sousa Da Silva
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) and Transplant Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Brian R Burg
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.,Pixium Vision, Paris, France
| | - Philipp Rudolf von Rohr
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Martin J Schuler
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Mark W Tibbitt
- Wyss Zurich Translational Center, ETH Zurich and University of Zurich, Zurich, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
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3
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Eshmuminov D, Hefti M, Mueller M, Schuler MJ, Bautista Borrego L, Schneider MA, Koch K, Weisskopf M, Tibbitt MW, Dutkowski P, Rudolf von Rohr P, Studt JD, Becker D, Clavien PA. Synthesis of coagulation factors during long-term ex situ liver perfusion. Artif Organs 2021; 46:273-280. [PMID: 34287985 DOI: 10.1111/aor.14041] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 02/25/2021] [Revised: 06/10/2021] [Accepted: 07/06/2021] [Indexed: 01/04/2023]
Abstract
Robust viability assessment of grafts during normothermic liver perfusion is a prerequisite for organ use. Coagulation parameters are used commonly for liver assessment in patients. However, they are not yet included in viability assessment during ex situ perfusion. In this study, we analysed coagulation parameters during one week ex situ perfusion at 34℃. Eight discarded human livers were perfused with blood-based, heparinised perfusate for one week; perfusions in a further four livers were terminated on day 4 due to massive ongoing cell death. Coagulation parameters were well below the physiologic range at perfusion start. Physiologic levels were achieved within the first two perfusion days for factor V (68.5 ± 35.5%), factor VII (83.5 ± 26.2%), fibrinogen (2.1 ± 0.4 g/L) and antithrombin (107 ± 26.5%) in the livers perfused for one week. Despite the increased production of coagulation factors, INR was detectable only at 24h of perfusion (2.1 ± 0.3) and prolonged thereafter (INR > 9). The prolongation of INR was related to the high heparin level in the perfusate (anti-FXa > 3 U/mL). Intriguingly, livers with ongoing massive cell death also disclosed synthesis of factor V and improved INR. In summary, perfused livers were able to produce coagulation factors at a physiological level ex situ. We propose that single coagulation factor analysis is more reliable for assessing the synthetic function of perfused livers as compared to INR when using a heparinised perfusate.
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Affiliation(s)
- Dilmurodjon Eshmuminov
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Matteo Mueller
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Martin J Schuler
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Marcel André Schneider
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Karin Koch
- Department of Medical Oncology and Hematology, University Hospital Zurich, Zurich, Switzerland
| | - Miriam Weisskopf
- Center of Surgical Research, University Hospital Zürich University of Zürich, Zurich, Switzerland
| | - Mark W Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Philipp Dutkowski
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Jan-Dirk Studt
- Department of Medical Oncology and Hematology, University Hospital Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Pierre-Alain Clavien
- Department of Surgery, Swiss Hepato-Pancreato-Biliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
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Eshmuminov D, Mueller M, Brugger SD, Bautista Borrego L, Becker D, Hefti M, Hagedorn C, Duskabilova M, Tibbitt MW, Dutkowski P, Rudolf von Rohr P, Schuler MJ, Mueller NJ, Clavien PA. Sources and prevention of graft infection during long-term ex situ liver perfusion. Transpl Infect Dis 2021; 23:e13623. [PMID: 33887094 DOI: 10.1111/tid.13623] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 10/29/2020] [Revised: 03/31/2021] [Accepted: 04/12/2021] [Indexed: 01/11/2023]
Abstract
INTRODUCTION The use of normothermic liver machine perfusion to repair injured grafts ex situ is an emerging topic of clinical importance. However, a major concern is the possibility of microbial contamination in the absence of a fully functional immune system. Here, we report a standardized approach to maintain sterility during normothermic liver machine perfusion of porcine livers for one week. METHODS Porcine livers (n = 42) were procured and perfused with blood at 34°C following aseptic technique and standard operating procedures. The antimicrobial prophylaxis was adapted and improved in a step-wise manner taking into account the pathogens that were detected during the development phase. Piperacillin-Tazobactam was applied as a single dose initially and modified to continuous application in the final protocol. In addition, the perfusion machine was improved to recapitulate partially the host's defense system. The final protocol was tested for infection prevention during one week of perfusion. RESULTS During the development phase, microbial contamination occurred in 27 out of 39 (69%) livers with a mean occurrence of growth on 4 ± 1.6 perfusion days. The recovered microorganisms suggested an exogenous source of microbial contamination. The antimicrobial agents (piperacillin/tazobactam) could be maintained above the targeted minimal inhibitory concentration (8-16 mg/L) only with continuous application. In addition to continuous application of piperacillin/tazobactam, partial recapitulation of the host immune system ex situ accompanied by strict preventive measures for contact and air contamination maintained sterility during one week of perfusion. CONCLUSION The work demonstrates feasibility of sterility maintenance for one week during ex situ normothermic liver perfusion.
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Affiliation(s)
- Dilmurodjon Eshmuminov
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Matteo Mueller
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Silvio D Brugger
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Catherine Hagedorn
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Muhayyo Duskabilova
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Mark W Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Philipp Dutkowski
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Martin J Schuler
- Wyss Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Nicolas J Mueller
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
| | - Pierre-Alain Clavien
- Department of Surgery, Swiss Hepatopancreatobiliary and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
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5
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Becker D, Eshmuminov D, Keller R, Mueller M, Bautista Borrego L, Hagedorn C, Duskabilova M, Tibbitt MW, Onder C, Clavien PA, Rudolf von Rohr P, Schuler MJ, Hefti M. Automated Insulin Delivery - Continuous Blood Glucose Control During Ex Situ Liver Perfusion. IEEE Trans Biomed Eng 2021; 68:1399-1408. [DOI: 10.1109/tbme.2020.3033663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Stamatopoulos C, Milionis A, Ackerl N, Donati M, Leudet de la Vallée P, Rudolf von Rohr P, Poulikakos D. Droplet Self-Propulsion on Superhydrophobic Microtracks. ACS Nano 2020; 14:12895-12904. [PMID: 32806052 DOI: 10.1021/acsnano.0c03849] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Liquid transport (continuous or segmented) in microfluidic platforms typically requires pumping devices or external fields working collaboratively with special fluid properties to enable fluid motion. Natural liquid adhesion on surfaces deters motion and promotes the possibility of liquid or surface contamination. Despite progress, significant advancements are needed before devices for passive liquid propulsion, without the input of external energy and unwanted contamination, become a reality in applications. Here we present an unexplored and facile approach based on the Laplace pressure imbalance, manifesting itself through targeted track texturing, driving passively droplet motion, while maintaining the limited contact of the Cassie-Baxter state on superhydrophobic surfaces. The track topography resembles out-of-plane, backgammon-board, slowly converging microridges decorated with nanotexturing. This design naturally deforms asymmetrically the menisci formed at the bottom of a droplet contacting such tracks and causes a Laplace pressure imbalance that drives droplet motion. We investigate this effect over a range of opening track angles and develop a model to explain and quantify the underlying mechanism of droplet self-propulsion. We further implement the developed topography for applications relevant to microfluidic platform functionalities. We demonstrate control of the rebound angle of vertically impacting droplets, achieve horizontal self-transport to distances up to 65 times the droplet diameter, show significant uphill motion against gravity, and illustrate a self-driven droplet-merging process.
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7
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Becker D, Hefti M, Schuler MJ, Borrego LB, Hagedorn C, Muller X, Graf R, Dutkowski P, Tibbitt MW, Onder C, Clavien PA, Eshmuminov D, von Rohr PR. Model Assisted Analysis of the Hepatic Arterial Buffer Response During Ex Vivo Porcine Liver Perfusion. IEEE Trans Biomed Eng 2020; 67:667-678. [DOI: 10.1109/tbme.2019.2919413] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Eshmuminov D, Becker D, Bautista Borrego L, Hefti M, Schuler MJ, Hagedorn C, Muller X, Mueller M, Onder C, Graf R, Weber A, Dutkowski P, Rudolf von Rohr P, Clavien PA. An integrated perfusion machine preserves injured human livers for 1 week. Nat Biotechnol 2020; 38:189-198. [PMID: 31932726 PMCID: PMC7008032 DOI: 10.1038/s41587-019-0374-x] [Citation(s) in RCA: 203] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 11/18/2019] [Indexed: 12/26/2022]
Abstract
The ability to preserve metabolically active livers ex vivo for 1 week or more could allow repair of poor-quality livers that would otherwise be declined for transplantation. Current approaches for normothermic perfusion can preserve human livers for only 24 h. Here we report a liver perfusion machine that integrates multiple core physiological functions, including automated management of glucose levels and oxygenation, waste-product removal and hematocrit control. We developed the machine in a stepwise fashion using pig livers. Study of multiple ex vivo parameters and early phase reperfusion in vivo demonstrated the viability of pig livers perfused for 1 week without the need for additional blood products or perfusate exchange. We tested the approach on ten injured human livers that had been declined for transplantation by all European centers. After a 7-d perfusion, six of the human livers showed preserved function as indicated by bile production, synthesis of coagulation factors, maintained cellular energy (ATP) and intact liver structure. Livers are stored long term in a sophisticated perfusion system.
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Affiliation(s)
- Dilmurodjon Eshmuminov
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Martin J Schuler
- Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Catherine Hagedorn
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Xavier Muller
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Matteo Mueller
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Christopher Onder
- Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Institute for Dynamic Systems and Control, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Rolf Graf
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Achim Weber
- Department of Pathology and Molecular Pathology, and Institute of Molecular Cancer Research (IMCR), University Zurich and University Hospital Zurich, Zurich, Switzerland
| | - Philipp Dutkowski
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland.,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Transport Processes and Reactions Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Pierre-Alain Clavien
- Department of Surgery and Transplantation, Swiss Hepato-Pancreato-Biliary (HPB) Center, University Hospital Zurich, Zurich, Switzerland. .,Wyss Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.
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9
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Gaikwad R, Reymond H, Phongprueksathat N, Rudolf von Rohr P, Urakawa A. From CO or CO2?: space-resolved insights into high-pressure CO2 hydrogenation to methanol over Cu/ZnO/Al2O3. Catal Sci Technol 2020. [DOI: 10.1039/d0cy00050g] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The temperature and pressure dependent reaction pathways of high-pressure CO2 hydrogenation over a Cu/ZnO/Al2O3 catalyst were studied through the gradients of reactants/products concentrations and catalyst temperature within the reactor.
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Affiliation(s)
- Rohit Gaikwad
- Institute of Chemical Research of Catalonia (ICIQ)
- 43007 Tarragona
- Spain
| | - Helena Reymond
- Department of Mechanical Engineering
- Institute of Process Engineering
- ETH Zurich
- 8092 Zürich
- Switzerland
| | - Nat Phongprueksathat
- Institute of Chemical Research of Catalonia (ICIQ)
- 43007 Tarragona
- Spain
- Catalysis Engineering
- Department of Chemical Engineering
| | - Philipp Rudolf von Rohr
- Department of Mechanical Engineering
- Institute of Process Engineering
- ETH Zurich
- 8092 Zürich
- Switzerland
| | - Atsushi Urakawa
- Institute of Chemical Research of Catalonia (ICIQ)
- 43007 Tarragona
- Spain
- Catalysis Engineering
- Department of Chemical Engineering
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10
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Stamatopoulos C, Bleuler P, Pfeiffer M, Hedtke S, Rudolf von Rohr P, Franck CM. Influence of Surface Wettability on Discharges from Water Drops in Electric Fields. Langmuir 2019; 35:4876-4885. [PMID: 30884239 DOI: 10.1021/acs.langmuir.9b00374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
It is known that electrified droplets deform and may become unstable when the electric field they are exposed to reaches a certain critical value. These instabilities are accompanied by electric discharges due to the local enhancement of the electric field caused by the deformed droplets. Here we report and highlight an interesting aspect of the behavior of unstable water droplets and discharge generation: by implementing wettability engineering, we can manipulate these discharges. We demonstrate that wettability strongly influences the shape of a droplet that is exposed to an electric field. The difference in shape is directly related to differences in the critical value of the applied electric field at which inception of discharge occurs. Using theoretical models, we can predict and sufficiently support our observations. Thus, by tailoring the wettability of the surface, we can control droplet's behavior from expediting the discharge inception to completely restricting it.
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Seidel CM, Brethauer S, Gyenge L, Rudolf von Rohr P, Studer MH. Two-stage steam explosion pretreatment of softwood with 2-naphthol as carbocation scavenger. Biotechnol Biofuels 2019; 12:37. [PMID: 30828382 PMCID: PMC6383249 DOI: 10.1186/s13068-019-1373-3] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Lignocellulosic biomass is considered as a potential source for sustainable biofuels. In the conversion process, a pretreatment step is necessary in order to overcome the biomass recalcitrance and allow for sufficient fermentable sugar yields in enzymatic hydrolysis. Steam explosion is a well known pretreatment method working without additional chemicals and allowing for efficient particle size reduction. However, it is not effective for the pretreatment of softwood and the harsh conditions necessary to achieve a highly digestible cellulose fraction lead to the partial degradation of the hemicellulosic sugars. Previous studies showed that the autohydrolysis pretreatreatment of softwood can benefit from the addition of 2-naphthol. This carbocation scavenger prevents lignin repolymerisation leading to an enhanced glucose yield in the subsequent enzymatic hydrolysis. RESULTS In order to prevent the degradation of the hemicellulose, we investigated in this study a two-stage 2-naphthol steam explosion pretreatment. In the first stage, spruce wood is pretreated at a severity which is optimal for the autocatalytic hydrolysis of the hemicellulose. The hydrolyzate containing the solubilized sugars is withdrawn from the reactor and the remaining solids are pretreated with different amounts of 2-naphthol in a second stage at a severity that allows for high glucose yields in enzymatic hydrolysis. The pretreated spruce was subjected to enzymatic hydrolysis and to simultaneous saccharification and fermentation (SSF). In the first stage, the maximal yield of hemicellulosic sugars was 47.5% at a pretreatment severity of log R 0 = 3.75 at 180 °C. In the second stage, a 2-naphthol dosage of 0.205 mol/mol lignin C9-unit increased the ethanol yield in SSF with a cellulose loading of 1% using the whole second stage pretreatment slurry by 17% from 73.6% for the control without 2-naphthol to 90.4%. At a higher solid loading corresponding to 5% w/w cellulose, the yields decreased due to higher concentrations of residual 2-naphthol in the biomass and the pretreatment liquor, but also due to higher concentrations of potential inhibitors like HMF, furfural and acetic acid. Experiments with washed solids, vacuum filtered solids and the whole slurry showed that residual 2-naphthol can inhibit the fermentation as a single inhibitor but also synergistically together with HMF, furfural and acetic acid. CONCLUSIONS This work shows that a two-stage pretreatment greatly enhances the recovery of hemicellulosic sugars from spruce wood. The presence of 2-naphthol in the second pretreatment stage can enhance the ethanol yield in SSF of steam explosion pretreated softwood at low cellulose concentrations of 1% w/w. However, with higher solid loadings of 5% w/w cellulose, the ethanol yields were in general lower due to the solid effect and a synergistic inhibition of HMF, furfural, acetic acid with residual 2-naphthol. The concentration of residual 2-naphthol tolerated by the yeast decreased with increasing concentrations of HMF, furfural, and acetic acid.
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Affiliation(s)
| | - Simone Brethauer
- School of Agricultural, Forest and Food Science, Bern University of Applied Science, Länggasse 85, 3052 Zollikofen, Switzerland
| | - László Gyenge
- School of Agricultural, Forest and Food Science, Bern University of Applied Science, Länggasse 85, 3052 Zollikofen, Switzerland
- Present Address: Faculty of Economics and Socio-Human Sciences and Engineering, Sapientia - Hungarian University of Transylvania, Miercurea Ciuc, Piaţa Libertăţii nr. 1, 530104 Cluj-Napoca, Romania
| | | | - Michael H. Studer
- School of Agricultural, Forest and Food Science, Bern University of Applied Science, Länggasse 85, 3052 Zollikofen, Switzerland
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Waskow A, Betschart J, Butscher D, Oberbossel G, Klöti D, Büttner-Mainik A, Adamcik J, von Rohr PR, Schuppler M. Characterization of Efficiency and Mechanisms of Cold Atmospheric Pressure Plasma Decontamination of Seeds for Sprout Production. Front Microbiol 2018; 9:3164. [PMID: 30619223 PMCID: PMC6305722 DOI: 10.3389/fmicb.2018.03164] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [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: 07/15/2018] [Accepted: 12/06/2018] [Indexed: 11/17/2022] Open
Abstract
The consumption of fresh fruit and vegetable products has strongly increased during the past few decades. However, inherent to all minimally processed products is the short shelf life, and the risk of foodborne diseases, which have been increasingly related to such products in many parts of the world. Because of the favorable conditions for the growth of bacteria during the germination of seeds, sprouts are a frequent source for pathogenic bacteria, thus highlighting the need for seed decontamination to reduce the risk of foodborne illness. Consequently, this study focused on cold atmospheric pressure plasma (CAPP) treatment of artificially inoculated seeds in a diffuse coplanar surface barrier discharge to determine the inactivation efficiency for relevant foodborne pathogens and fungal spores. Plasma treatment of seeds resulted in a highly efficient reduction of microorganisms on the seed surface, while preserving the germination properties of seeds, at least for moderate treatment times. To characterize the mechanisms that contribute to microbial inactivation during plasma treatment, an experimental setup was developed to separate ultraviolet light (UV) and other plasma components. The combination of bacterial viability staining with confocal laser scanning microscopy was used to investigate the impact of ozone and other reactive species on the bacterial cells in comparison to UV. Further characterization of the effect of CAPP on bacterial cells by atomic force microscopy imaging of the same Escherichia coli cells before and after treatment revealed an increase in the surface roughness of treated E. coli cells and a decrease in the average height of the cells, which suggests physical damage to the cell envelope. In conclusion, CAPP shows potential for use as a decontamination technology in the production process of sprouts, which may contribute to food safety and prolonged shelf life of the product.
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Affiliation(s)
- Alexandra Waskow
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Julian Betschart
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Denis Butscher
- Institute of Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Gina Oberbossel
- Institute of Process Engineering, ETH Zurich, Zurich, Switzerland
| | | | | | - Jozef Adamcik
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | | | - Markus Schuppler
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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Eshmuminov D, Leoni F, Schneider MA, Becker D, Muller X, Hefti M, Schuler MJ, Onder C, Dutkowski P, Graf R, Rudolf von Rohr P, Clavien PA, Bautista Borrego L. Reply to “Ex situ
normothermic machine perfusion of donor livers using a haemoglobin-based oxygen carrier: a viable alternative to red blood cells”. Transpl Int 2018; 31:1283-1284. [DOI: 10.1111/tri.13331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Dilmurodjon Eshmuminov
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Filippo Leoni
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Marcel André Schneider
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Dustin Becker
- Wyss Zurich - ETH Zurich; University of Zurich; Zurich Switzerland
| | - Xavier Muller
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Max Hefti
- Wyss Zurich - ETH Zurich; University of Zurich; Zurich Switzerland
| | | | - Christopher Onder
- Institute for Dynamic Systems and Control; ETH Zurich; Zurich Switzerland
| | - Philipp Dutkowski
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Rolf Graf
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | | | - Pierre-Alain Clavien
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery; Swiss Hepatopancreatobiliary and Transplantation Center; University Hospital Zurich; Zurich Switzerland
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15
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dos Santos EC, Ładosz A, Maggioni GM, Rudolf von Rohr P, Mazzotti M. Characterization of shapes and volumes of droplets generated in PDMS T-junctions to study nucleation. Chem Eng Res Des 2018. [DOI: 10.1016/j.cherd.2018.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Corral-Pérez JJ, Bansode A, Praveen CS, Kokalj A, Reymond H, Comas-Vives A, VandeVondele J, Copéret C, von Rohr PR, Urakawa A. Decisive Role of Perimeter Sites in Silica-Supported Ag Nanoparticles in Selective Hydrogenation of CO2 to Methyl Formate in the Presence of Methanol. J Am Chem Soc 2018; 140:13884-13891. [DOI: 10.1021/jacs.8b08505] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Juan José Corral-Pérez
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, 43007 Tarragona, Spain
| | - Atul Bansode
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, 43007 Tarragona, Spain
| | - C. S. Praveen
- Department of Materials, ETH Zürich, CH-8093 Zürich, Switzerland
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Anton Kokalj
- Department of Physical and Organic Chemistry, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Helena Reymond
- Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Aleix Comas-Vives
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Catalonia, Spain
| | | | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | | | - Atsushi Urakawa
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, 43007 Tarragona, Spain
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17
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Sharma CS, Stamatopoulos C, Suter R, von Rohr PR, Poulikakos D. Rationally 3D-Textured Copper Surfaces for Laplace Pressure Imbalance-Induced Enhancement in Dropwise Condensation. ACS Appl Mater Interfaces 2018; 10:29127-29135. [PMID: 30067013 DOI: 10.1021/acsami.8b09067] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Enhancing the thermal efficiency of a broad range of condenser devices requires means of achieving sustainable dropwise condensation on metallic surfaces, where heat transfer can be further enhanced, by harvesting the advantage of the sweeping action of vapor flow over the surface, facilitating a reduction in the droplet departure diameter. Here, we present a rationally driven, hierarchical texturing process of copper surfaces, guided by fundamental principles of wettability and coalescence, which achieves controlled droplet departure under vapor flow conditions and thus significantly enhances phase change thermal transport. The desired texture is attained by fabricating an array of 3D laser-structured truncated microcones on the surface, covered with papillae-like nanostructures and a hydrolytically stable, low surface energy self-assembled-monolayer coating. Passive droplet departure on this surface is achieved through progressive coalescence of droplets arising from microcavities formed by the microcone array, resulting in depinning and subsequent departure of the depinned condensate drops through vapor shear. The synergistic combination of vapor shear and the sustained dropwise condensation on the hierarchical copper surface results in a nearly 700% increase in heat transfer coefficients as compared to filmwise condensation from identical, standard unstructured surfaces.
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18
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Eshmuminov D, Leoni F, Schneider MA, Becker D, Muller X, Onder C, Hefti M, Schuler MJ, Dutkowski P, Graf R, Rudolf von Rohr P, Clavien PA, Bautista Borrego L. Perfusion settings and additives in liver normothermic machine perfusion with red blood cells as oxygen carrier. A systematic review of human and porcine perfusion protocols. Transpl Int 2018; 31:956-969. [PMID: 29928775 DOI: 10.1111/tri.13306] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [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: 05/01/2018] [Revised: 06/10/2018] [Accepted: 06/18/2018] [Indexed: 12/30/2022]
Abstract
Liver machine perfusion (MP) at normothermic temperature (NMP) is a promising way to preserve and evaluate extended criteria donor livers. Currently, no consensus exists in methodology and perfusion protocols. Here, the authors performed a systematic literature search to identify human and porcine studies reporting on liver NMP with red blood cells. A qualitative synthesis was performed concerning technical aspects of MP, fluid composition, gas supply, and liver positioning. Thirty-seven publications including 11 human and 26 porcine studies were considered for qualitative synthesis. Control mode, pressure, flow, perfusate additives, and targeted blood gas parameters varied across human as well as porcine studies. For future analyses, it is advisable to report flow adjusted to liver weight and exact pressure parameters including mean, systolic, and diastolic pressure. Parenteral nutrition and insulin addition was common. Parenteral nutrition included amino acids and/or glucose without lipids. Taurocholic acid derivatives were used as bile flow promoters. However, short-term human NMP without taurocholic acid derivatives seems to be possible. This finding is relevant due to the lack of clinical grade bile salts. Near physiological oxygen tension in the perfusate is doable by adjusting gas flows, while blood gas parameters regulation needs more detailed description.
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Affiliation(s)
- Dilmurodjon Eshmuminov
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Filippo Leoni
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Marcel André Schneider
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Dustin Becker
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Xavier Muller
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Christopher Onder
- Institute for Dynamic Systems and Control, ETH Zurich, Zurich, Switzerland
| | - Max Hefti
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Martin J Schuler
- Wyss Zurich - ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Philipp Dutkowski
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Rolf Graf
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | | | - Pierre-Alain Clavien
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
| | - Lucia Bautista Borrego
- Department of Surgery, Swiss HPB and Transplantation Center, University Hospital Zurich, Zurich, Switzerland
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19
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Reymond H, Corral-Pérez JJ, Urakawa A, Rudolf von Rohr P. Towards a continuous formic acid synthesis: a two-step carbon dioxide hydrogenation in flow. REACT CHEM ENG 2018. [DOI: 10.1039/c8re00142a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The need for long term, large-scale storage solutions to match surplus renewable energy with demand drives technological innovation towards a low-carbon economy.
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Affiliation(s)
- Helena Reymond
- Department of Mechanical and Process Engineering
- ETH Zürich
- Zürich
- Switzerland
| | - Juan José Corral-Pérez
- Institute of Chemical Research of Catalonia (ICIQ)
- The Barcelona Institute of Science and Technology
- 43007 Tarragona
- Spain
| | - Atsushi Urakawa
- Institute of Chemical Research of Catalonia (ICIQ)
- The Barcelona Institute of Science and Technology
- 43007 Tarragona
- Spain
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20
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Reymond H, Rudolf von Rohr P. Micro-view-cell for phase behaviour and in situ Raman analysis of heterogeneously catalysed CO 2 hydrogenation. Rev Sci Instrum 2017; 88:114103. [PMID: 29195391 DOI: 10.1063/1.4989910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The operando study of CO2 hydrogenation is fundamental for a more rational optimisation of heterogeneous catalyst and reactor designs. To further complement the established efficiency of microreactors in reaction screening and bridge the operating and optical gaps, a micro-view-cell is presented for Raman microscopy at extreme conditions with minimum flow interference for genuine reaction analysis. Based on a flat sapphire window unit sealed in a plug flow-type enclosure holding the sample, the cell features unique 14 mm working distance and 0.36 numerical aperture and resists 400 °C and 500 bars. The use of the cell as an in situ tool for fast process monitoring and surface catalyst characterisation is demonstrated with phase behaviour and chemical analysis of the methanol synthesis over a commercial Cu/ZnO/Al2O3 catalyst.
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Affiliation(s)
- Helena Reymond
- Department of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092 Zürich, Switzerland
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21
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Song F, Schmid T, Häfeli R, von Rohr PR. A Numerical Research on Limits of the Dispersion Model. CHEM-ING-TECH 2017. [DOI: 10.1002/cite.201600024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Feifei Song
- ETH Zurich; Institute of Process Engineering; Sonneggstrasse 3 8092 Zurich Switzerland
| | - Thomas Schmid
- ETH Zurich; Institute of Process Engineering; Sonneggstrasse 3 8092 Zurich Switzerland
| | - Richard Häfeli
- ETH Zurich; Institute of Process Engineering; Sonneggstrasse 3 8092 Zurich Switzerland
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22
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Pielhop T, Amgarten J, Studer MH, von Rohr PR. Pilot-scale steam explosion pretreatment with 2-naphthol to overcome high softwood recalcitrance. Biotechnol Biofuels 2017; 10:130. [PMID: 28529543 PMCID: PMC5437563 DOI: 10.1186/s13068-017-0816-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/02/2017] [Indexed: 05/11/2023]
Abstract
BACKGROUND Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. It is however not effective for overcoming the extremely high recalcitrance of softwood to biochemical conversion. Recent fundamental research in small-scale liquid hot water pretreatment has shown, though, that the addition of a carbocation scavenger like 2-naphthol can prevent lignin repolymerization and thus enhance the enzymatic digestibility of softwood cellulose. This work studies the technical application potential of this approach in a larger steam explosion pilot plant for surmounting softwood recalcitrance. RESULTS The addition of 35.36 g 2-naphthol to the steam explosion pretreatment of 1.5 kg spruce wood chips allowed to considerably enhance the enzymatic cellulose digestibility. Different ways of adding the solid 2-naphthol to steam pretreatment were tested. Mixing with the biomass before pretreatment could enhance digestibility by up to 55% compared to control experiments. Impregnation of the biomass with 2-naphthol was yet more effective. Acetone and ethanol were tested to dissolve 2-naphthol and impregnate the biomass. The solvents were then removed again by evaporation before the pretreatment. The impregnation allowed to enhance digestibility by up to 179 and 192%, respectively. A comparison to prevalent acid-catalyzed steam explosion pretreatments for softwood revealed that the scavenger approach allows for obtaining exceptionally high yields in enzymatic hydrolysis. The biomass impregnation with 2-naphthol even renders a complete enzymatic cellulose conversion possible, which is remarkable for a softwood pretreatment not removing lignin. Steam pretreatment experiments without explosive decompression revealed that the enhancing effects of the explosion and the scavenger complement each other well. The explosion enhances the accessibility of the cellulose while the use of the scavenger reduces particularly the deactivation of enzymes. CONCLUSIONS This is the first study to show that a carbocation scavenger in steam pretreatment can enhance the enzymatic digestibility of lignocellulosic biomass. The approach opens up a novel possibility for overcoming the high softwood recalcitrance in a process that does not require an acid catalyst or the removal of lignin from the biomass.
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Affiliation(s)
- Thomas Pielhop
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Janick Amgarten
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Michael H. Studer
- School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
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Altheimer M, Becker D, D'Aleo FP, Rudolf von Rohr P. Response to the Letter by Huchet concerning the paper titled “Flow regime and liquid-solid mass transfer investigation in a designed porous structure using electrochemical micro-probes”. Chem Eng Sci 2017. [DOI: 10.1016/j.ces.2017.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Affiliation(s)
- Sergio Vernuccio
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse
3, 8092 Zurich, Switzerland
| | - Adrian Meier
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse
3, 8092 Zurich, Switzerland
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25
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Reymond H, Amado-Blanco V, Lauper A, Rudolf von Rohr P. Interplay between Reaction and Phase Behaviour in Carbon Dioxide Hydrogenation to Methanol. ChemSusChem 2017; 10:1166-1174. [PMID: 27981806 DOI: 10.1002/cssc.201601361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 10/20/2016] [Indexed: 06/06/2023]
Abstract
Condensation promotes CO2 hydrogenation to CH3 OH beyond equilibrium through in situ product separation. Although primordial for catalyst and reactor design, triggering conditions as well as the impact on sub-equilibrium reaction behaviour remain unclear. Herein we used an in-house designed micro-view-cell to gain chemical and physical insights into reaction and phase behaviour under high-pressure conditions over a commercial Cu/ZnO/Al2 O3 catalyst. Raman microscopy and video monitoring, combined with online gas chromatography analysis, allowed the complete characterisation of the reaction bulk up to 450 bar (1 bar=0.1 MPa) and 350 °C. Dew points of typical effluent streams related to a parametric study suggest that the improving reaction performance and reverting selectivities observed from 230 °C strongly correlate with (i) a regime transition from kinetic to thermodynamic, and (ii) a phase transition from a single supercritical to a biphasic reaction mixture. Our results advance a rationale behind transitioning CH3 OH selectivities for an improved understanding of CO2 hydrogenation under high pressure.
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Affiliation(s)
- Helena Reymond
- Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland
| | - Victor Amado-Blanco
- Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland
| | - Andreas Lauper
- Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland
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26
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Affiliation(s)
- Helena Reymond
- Department of Process Engineering, ETH Zürich, Sonneggstrasse
3, 8092 Zürich, Switzerland
| | - Selin Vitas
- Department of Process Engineering, ETH Zürich, Sonneggstrasse
3, 8092 Zürich, Switzerland
| | - Sergio Vernuccio
- Department of Process Engineering, ETH Zürich, Sonneggstrasse
3, 8092 Zürich, Switzerland
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27
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Seidel CM, Pielhop T, Studer MH, Rudolf von Rohr P. The influence of the explosive decompression in steam-explosion pretreatment on the enzymatic digestibility of different biomasses. Faraday Discuss 2017; 202:269-280. [DOI: 10.1039/c7fd00066a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the production of second generation biofuels from lignocellulosic biomass, pretreatment of the biomass feedstock is necessary to overcome its recalcitrance in order to gain fermentable sugars. Due to many reasons, steam-explosion pretreatment is currently the most commonly used pretreatment method for lignocellulosic biomass on a commercial scale [S. Brethauer and M. H. Studer, CHIMIA, 2015, 69, 572–581]. In contrast to others, we showed that the explosive decompression at the end of this pretreatment step can have a positive influence on the enzymatic digestibility of softwood, especially in combination with high enzyme dosages [T. Pielhop, et al., Biotechnology for Biofuels, 2016, 9, 152]. In this study, the influence of the explosive decompression on the enzymatic digestibility of hardwood and herbaceous plants was systematically studied. Beech and corn stover were pretreated under different pretreatment conditions and enzymatically hydrolysed with different enzyme dosages. The maximum enhancement of the digestibility of corn stover was 16.53% after a 2.5 min pretreatment step at 15 barg steam pressure. For beech, a maximum relative enhancement of 58.29% after a 10 min pretreatment step at 15 barg steam pressure could be reached. With this, we show that the explosive decompression can also enhance the enzymatic cellulose digestibility of hardwood and herbaceous plants.
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Affiliation(s)
| | - Thomas Pielhop
- Institute of Process Engineering
- ETH Zurich
- 8092 Zurich
- Switzerland
| | - Michael H. Studer
- School of Agricultural
- Forest and Food Sciences
- Bern University of Applied Sciences
- 3052 Zollikofen
- Switzerland
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28
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Altheimer M, Becker D, D'Aleo FP, Rudolf von Rohr P. Flow regime and liquid–solid mass transfer investigation in a designed porous structure using electrochemical micro-probes. Chem Eng Sci 2016. [DOI: 10.1016/j.ces.2016.06.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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29
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Butscher D, Van Loon H, Waskow A, Rudolf von Rohr P, Schuppler M. Plasma inactivation of microorganisms on sprout seeds in a dielectric barrier discharge. Int J Food Microbiol 2016; 238:222-232. [PMID: 27668570 DOI: 10.1016/j.ijfoodmicro.2016.09.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [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: 04/11/2016] [Revised: 08/31/2016] [Accepted: 09/11/2016] [Indexed: 11/29/2022]
Abstract
Fresh produce is frequently contaminated by microorganisms, which may lead to spoilage or even pose a threat to human health. In particular sprouts are considered to be among the most risky foods sold at retail since they are grown in an environment practically ideal for growth of bacteria and usually consumed raw. Because heat treatment has a detrimental effect on the germination abilities of sprout seeds, alternative treatment technologies need to be developed for microbial inactivation purposes. In this study, non-thermal plasma decontamination of sprout seeds is evaluated as a promising option to enhance food safety while maintaining the seed germination capabilities. In detail, investigations focus on understanding the efficiency of non-thermal plasma inactivation of microorganisms as influenced by the type of microbial contamination, substrate surface properties and moisture content, as well as variations in the power input to the plasma device. To evaluate the impact of these parameters, we studied the reduction of native microbiota or artificially applied E. coli on alfalfa, onion, radish and cress seeds exposed to non-thermal plasma in an atmospheric pressure pulsed dielectric barrier discharge streamed with argon. Plasma treatment resulted in a maximum reduction of 3.4 logarithmic units for E. coli on cress seeds. A major challenge in plasma decontamination of granular food products turned out to be the complex surface topology, where the rough surface with cracks and crevices can shield microorganisms from plasma-generated reactive species, thus reducing the treatment efficiency. However, improvement of the inactivation efficiency was possible by optimizing substrate characteristics such as the moisture level and by tuning the power supply settings (voltage, frequency) to increase the production of reactive species. While the germination ability of alfalfa seeds was considerably decreased by harsh plasma treatment, enhanced germination was observed under mild conditions. In conclusion, the results from this study indicate that cold plasma treatment represents a promising technology for inactivation of bacteria on seeds used for sprout production while preserving their germination properties.
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Affiliation(s)
- Denis Butscher
- ETH Zurich, Institute of Process Engineering, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Hanne Van Loon
- ETH Zurich, Institute of Process Engineering, Sonneggstrasse 3, 8092 Zurich, Switzerland; ETH Zurich, Institute of Food Science and Nutrition, Schmelzbergstrasse 7, 8092 Zurich, Switzerland
| | - Alexandra Waskow
- ETH Zurich, Institute of Process Engineering, Sonneggstrasse 3, 8092 Zurich, Switzerland; ETH Zurich, Institute of Food Science and Nutrition, Schmelzbergstrasse 7, 8092 Zurich, Switzerland
| | | | - Markus Schuppler
- ETH Zurich, Institute of Food Science and Nutrition, Schmelzbergstrasse 7, 8092 Zurich, Switzerland.
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Pielhop T, Amgarten J, von Rohr PR, Studer MH. Steam explosion pretreatment of softwood: the effect of the explosive decompression on enzymatic digestibility. Biotechnol Biofuels 2016; 9:152. [PMID: 27453727 PMCID: PMC4957380 DOI: 10.1186/s13068-016-0567-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/12/2016] [Indexed: 05/02/2023]
Abstract
BACKGROUND Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. The information available about the effect of the explosive decompression on the biochemical conversion is, however, very limited, and no studies prove that the latter is actually enhanced by the explosion. Hence, it is of great value to discern between the effect of the explosion on the one hand and the steaming on the other hand, to identify their particular influences on enzymatic digestibility. RESULTS The effect of the explosive decompression in the steam explosion pretreatment of spruce wood chips on their enzymatic cellulose digestibility was studied systematically. The explosion had a high influence on digestibility, improving it by up to 90 % compared to a steam pretreatment without explosion. Two factors were identified to be essentially responsible for the effect of the explosion on enzymatic digestibility: pretreatment severity and pressure difference of the explosion. A higher pretreatment severity can soften up and weaken the lignocellulose structure more, so that the explosion can better break up the biomass and decrease its particle size, which enhances its digestibility. In particular, increasing the pressure difference of the explosion leads to more defibration, a smaller particle size and a better digestibility. Though differences were found in the micro- and nanostructure of exploded and non-exploded biomass, the only influence of the explosion on digestibility was found to be the macroscopic particle size reduction. Steam explosion treatments with a high severity and a high pressure difference of the explosion lead to a comparatively high cellulose digestibility of the-typically very recalcitrant-softwood biomass. CONCLUSIONS This is the first study to show that explosion can enhance the enzymatic digestibility of lignocellulosic biomass. If the enhancing effect of the explosion is thoroughly exploited, even very recalcitrant biomass like softwood can be made enzymatically digestible.
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Affiliation(s)
- Thomas Pielhop
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Janick Amgarten
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Michael H. Studer
- />Laboratory for Bioenergy and Biochemicals, School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
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Butscher D, Zimmermann D, Schuppler M, Rudolf von Rohr P. Plasma inactivation of bacterial endospores on wheat grains and polymeric model substrates in a dielectric barrier discharge. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.09.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Vernuccio S, von Rohr PR, Medlock J. General Kinetic Modeling of the Selective Hydrogenation of 2-Methyl-3-butyn-2-ol over a Commercial Palladium-Based Catalyst. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b03424] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergio Vernuccio
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | | | - Jonathan Medlock
- Research & Development, DSM Nutritional Products, 4002 Basel, Switzerland
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Butscher D, Schlup T, Roth C, Müller-Fischer N, Gantenbein-Demarchi C, Rudolf von Rohr P. Inactivation of microorganisms on granular materials: Reduction of Bacillus amyloliquefaciens endospores on wheat grains in a low pressure plasma circulating fluidized bed reactor. J FOOD ENG 2015. [DOI: 10.1016/j.jfoodeng.2015.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [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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Zenklusen A, Walser S, Rudolf von Rohr P. Influence of ligament shape and thickness on vortex shedding in highly porous structures. Chem Eng Sci 2015. [DOI: 10.1016/j.ces.2014.12.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schuler MJ, Rothenfluh T, Rudolf von Rohr P. “Stagnation flow heat transfer of confined, impinging hot water jets under supercritical pressures”. J Supercrit Fluids 2015. [DOI: 10.1016/j.supflu.2015.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schuler MJ, Rothenfluh T, Stathopoulos P, Brkic D, Meier T, Rudolf von Rohr P. Simulating Supercritical Water Jets with a Variable Turbulent Prandtl Number. Chem Eng Technol 2014. [DOI: 10.1002/ceat.201300661] [Citation(s) in RCA: 10] [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: 11/09/2022]
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Rothenfluh T, Schuler MJ, Rudolf von Rohr P. Experimental heat transfer study on impinging, turbulent, near-critical water jets confined by an annular wall. J Supercrit Fluids 2013. [DOI: 10.1016/j.supflu.2013.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Schuler MJ, Rothenfluh T, Rudolf von Rohr P. Simulation of the thermal field of submerged supercritical water jets at near-critical pressures. J Supercrit Fluids 2013. [DOI: 10.1016/j.supflu.2012.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bansode A, Tidona B, von Rohr PR, Urakawa A. Impact of K and Ba promoters on CO2hydrogenation over Cu/Al2O3catalysts at high pressure. Catal Sci Technol 2013. [DOI: 10.1039/c2cy20604h] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Butscher A, Bohner M, Roth C, Ernstberger A, Heuberger R, Doebelin N, Rudolf von Rohr P, Müller R. Printability of calcium phosphate powders for three-dimensional printing of tissue engineering scaffolds. Acta Biomater 2012; 8:373-85. [PMID: 21925623 DOI: 10.1016/j.actbio.2011.08.027] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 08/12/2011] [Accepted: 08/31/2011] [Indexed: 11/24/2022]
Abstract
Three-dimensional printing (3DP) is a versatile method to produce scaffolds for tissue engineering. In 3DP the solid is created by the reaction of a liquid selectively sprayed onto a powder bed. Despite the importance of the powder properties, there has to date been a relatively poor understanding of the relation between the powder properties and the printing outcome. This article aims at improving this understanding by looking at the link between key powder parameters (particle size, flowability, roughness, wettability) and printing accuracy. These powder parameters are determined as key factors with a predictive value for the final 3DP outcome. Promising results can be expected for mean particle size in the range of 20-35 μm, compaction rate in the range of 1.3-1.4, flowability in the range of 5-7 and powder bed surface roughness of 10-25 μm. Finally, possible steps and strategies in pushing the physical limits concerning improved quality in 3DP are addressed and discussed.
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Voitl T, von Rohr PR. Reply to “Comments on ‘Demonstration of a Process for the Conversion of Kraft Lignin into Vanillin and Methyl Vanillate by Acidic Oxidation in Aqueous Methanol’”. Ind Eng Chem Res 2010. [DOI: 10.1021/ie100313f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tobias Voitl
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich
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Voitl T, Rohr PRV. Demonstration of a Process for the Conversion of Kraft Lignin into Vanillin and Methyl Vanillate by Acidic Oxidation in Aqueous Methanol. Ind Eng Chem Res 2009. [DOI: 10.1021/ie901293p] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tobias Voitl
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
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Abstract
A novel approach has been developed in order to use Kraft lignin as a renewable resource for the production of chemicals. The concept is based on the use of polyoxometalates as reversible oxidants and on the use of radical scavengers, which prevent lignin fragments from repolymerizing. The oxidation of Kraft lignin, which is a potential source of functionalized phenols, by H3PMo12O40 in water yields a relatively small amount of monomeric species detected by GC-MS. The addition of methanol to the reaction resulted in an increase in the yield of monomeric products by a factor of up to 15. Vanillin and methyl vanillate are the main products obtained, in a maximum yield of 5 wt % based on dry Kraft lignin. Methanol plays a decisive role in the prevention of repolymerization by reducing lignin-lignin condensation reactions. Furthermore, it is proposed that methanol generates small amounts of .CH3 and CH3O. radicals through the acid-catalyzed formation of dimethyl ether which couple with lignin fragments.
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Affiliation(s)
- Tobias Voitl
- Institute of Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
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Urakawa A, Trachsel F, von Rohr PR, Baiker A. On-chip Raman analysis of heterogeneous catalytic reaction in supercritical CO2: phase behaviour monitoring and activity profiling. Analyst 2008; 133:1352-4. [DOI: 10.1039/b808984c] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Studer M, Rudolf von Rohr P. Novel membrane bioreactor: Able to cope with fluctuating loads, poorly water soluble VOCs, and biomass accumulation. Biotechnol Bioeng 2007; 99:38-48. [PMID: 17570707 DOI: 10.1002/bit.21532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Biological waste gas treatment is an attractive method for controlling air emissions of volatile organic compounds (VOCs). Microorganisms degrade the VOCs to harmless products such as carbon dioxide (CO(2)), biomass and water. In spite of the advantages, significant unresolved challenges remain for biological waste gas treatment. Fluctuating loads in waste gas streams, especially of VOCs with low water solubility, can often not be satisfactorily removed. Concentration peaks leave the reactor virtually untreated, while periods without VOCs in the waste gas lead to starvation of the bacteria. Furthermore, bioreactors are often subject to clogging due to biomass accumulation. In the current work, a flat sheet membrane bioreactor was developed which was able to buffer fluctuating loads of toluene, our model compound, by absorption in silicone oil prior to degradation and which continuously removed and discharged excess biomass from the reactor. The absorption and the biodegradation were both membrane based. An inverse bacterial biofilm developed on the membrane, which separated the culture medium from the absorbent. The culture medium was constantly passed along the biofilm, introducing shear stresses on the surface and thereby removing excess, inactive biomass. The toluene surface elimination capacity was virtually independent of the gas flow rate for the tested steady-state conditions and reached a maximum of 0.6 g m(-2) h(-1). Experiments with fluctuating inlet mass flow rates of toluene confirmed the excellent buffering capability of the set-up. The reactor was successfully operated for 162 days without clogging.
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Affiliation(s)
- Michael Studer
- ETH Zurich, Transport Processes and Reactions Laboratory, Institute of Process Engineering, Sonneggstrasse 3, ML, CH-8092 Zurich, Switzerland
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