113 results on '"Meckel T"'
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2. Accessibility of fiber surface sites for polymeric additives determines dry and wet tensile strength of paper sheets
- Author
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Schäfer, J.-L., Schölch, S., Prucker, O., Brandstetter, T., Rühe, J., Stockert, A. Ritter v., Meckel, T., and Biesalski, M.
- Published
- 2021
- Full Text
- View/download PDF
3. Maturing global CO2 storage resources on offshore continental margins to achieve 2DS emissions reductions
- Author
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Ringrose, P. S. and Meckel, T. A.
- Published
- 2019
- Full Text
- View/download PDF
4. Nanoscale pores introduced into paper via mesoporous silica coatings using sol–gel chemistry
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Mikolei, J. J., primary, Richter, D., additional, Pardehkhorram, R., additional, Helbrecht, C., additional, Schabel, S., additional, Meckel, T., additional, Biesalski, M., additional, Ceolin, M., additional, and Andrieu-Brunsen, A., additional
- Published
- 2023
- Full Text
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5. Update: Wie das Wasser im Fisch bleibt – Natriumcarbonat in Fisch und Fischerzeugnissen
- Author
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Foik, S.‐M., primary, Meckel, T., additional, Hegmanns, M., additional, Straub, I., additional, and Möllers, M., additional
- Published
- 2022
- Full Text
- View/download PDF
6. Final Report
- Author
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Akhbari, D., primary, Akkutlu, Y, additional, Altman, S. J., additional, Aman, M, additional, Aminzadeh, B, additional, Arbogast, T., additional, Bagaria, H. G., additional, Balhoff, M, additional, Bauer, S. J., additional, Bennett, P. C., additional, Bhagmane, J., additional, Bielawski, C. W., additional, Bishop, J. E., additional, Biswal, S. L., additional, Bollinger, J. A., additional, Bowden, M. E., additional, Boyd, V., additional, Broome, S. T., additional, Bryant, S., additional, Bryndzia, T, additional, Butler, D, additional, Cardenas, B, additional, Cassidy, M, additional, Cha, M, additional, Chan, M.A., additional, Chang, C, additional, Chaudhary, k, additional, Chen, X., additional, Chen, H, additional, Chen, Y, additional, Chini, G. P., additional, Choens, C, additional, Chojnicki, Kirsten, additional, Chung, D H, additional, Cole, D. R., additional, Cornell, K. A., additional, Craddock, P, additional, Criscenti, L. J., additional, Cui, L, additional, Cygan, R T, additional, Daigle, H, additional, Daniel, S R, additional, Davison, S M, additional, Dehghanpour, H, additional, Delshad, M, additional, Deng, W, additional, Dewers, T A, additional, DiCarlo, D, additional, Dong, J, additional, Duan, Z, additional, Eichhubl, P, additional, Elhag, A S, additional, Ellison, C J, additional, Espinoza, D N, additional, Estep, D, additional, Evans, J, additional, Fanizza, M F, additional, Foster, L M, additional, Foster, E L, additional, Fouke, B W, additional, Ganis, B, additional, Geier, M, additional, Ghosh, R, additional, Gilbert, K, additional, Gomez, S, additional, Guiltinan, E J, additional, Hackley, P C, additional, Hardy, C D, additional, Hart, D B, additional, Hayman, N W, additional, He, B, additional, Heath, J E, additional, Hernandez-Uribe, L. Alberto, additional, Hess, N J, additional, Hesse, M A, additional, Hirasaki, G J, additional, Ho, T A, additional, Ho, J, additional, Hosseini, S A, additional, Hu, M, additional, Huang, C S, additional, Hueckel, T, additional, Huh, C, additional, Hung, C H, additional, Ilgen, A G, additional, Illangasekare, T. H., additional, Ingram, D R, additional, Iqbal, M, additional, Islan, A, additional, Jammoul, M, additional, Javier, K J, additional, Jensen, E W, additional, Jessen, K, additional, Jiang, H, additional, Jin, S, additional, Joekar-Niasar, V, additional, Johnston, K P, additional, Jung, J, additional, Jung, H, additional, Juntunen, M, additional, Kang, Q, additional, Katz, L, additional, Kelemen, P B, additional, Kelkar, C W, additional, Kelly, E D, additional, Ketcham, R A, additional, Kharaka, Y K, additional, Kianinejad, A, additional, Killough, J E, additional, Kim, S, additional, Kim, K, additional, Kim, M F, additional, Kirk, M F, additional, Kitnidis, P, additional, Kmetz, A A, additional, Kneafsey, T J, additional, Kobos, P, additional, Kong, X, additional, Kotsmar, C, additional, Krafczyk, M, additional, Krishnamurthy, P G, additional, Kruichak, J N, additional, Kucala, A, additional, Kumar, K, additional, Kwok, A, additional, Lake, L, additional, Larson, E S, additional, Larson, T E, additional, Lee, S, additional, Lee, Y J, additional, Lee, J, additional, Lee, W, additional, Leist, E A, additional, Leung, W, additional, Leung, J Y, additional, Leung, Y, additional, Liang, Y, additional, Lin, E L, additional, Lisabeth, H P, additional, Liu, R, additional, Liu, H, additional, Liu, Z C, additional, Lotfollahi, M, additional, Luo, L S, additional, Lützenkirchen, J, additional, Lyon, B A, additional, Ma, K, additional, Maisano, J A, additional, Major, J R, additional, Martinez, M J, additional, Matteo, E, additional, McFadden, C, additional, McGrath, L K, additional, McKenna, S A, additional, McNeece, C J, additional, Meckel, T A, additional, Mehmani, A, additional, Mehmani, Y, additional, Merino, E, additional, Metaxas, A E, additional, Mikelić, A, additional, Milner, T E, additional, Mirzaei, M, additional, Moaseri, E, additional, Mozley, P S, additional, Myshakin, E M, additional, Nakshatrala, K B, additional, Neilson, B M, additional, Newell, P, additional, Nguyen, Q P, additional, Noble, D R, additional, Noguera, J A, additional, Olson, J E, additional, Omelon, C R, additional, Oostrom, M, additional, Ortiz, M R, additional, Ovaysi, S, additional, Parks, M L, additional, Pasquali, A, additional, Pastora, L E, additional, Pencheva, G, additional, Pennell, K D, additional, Perego, M, additional, Perkins, W A, additional, Person, M, additional, Peterman, A H, additional, Petersen, R T, additional, Phan, S, additional, Pike, D Q, additional, Prigiobbe, V, additional, Prodanovic, M, additional, Pyrak-Nolte, L J, additional, Quintanilla, H, additional, Raduha, S, additional, Rakowski, C L, additional, Ramos, M J, additional, Reber, J E, additional, Reddy, P R, additional, Requeiro, R A, additional, Richmond, M C, additional, Rinehart, A G, additional, Roach, C M, additional, Roberts, M, additional, Romanak, K D, additional, Romanov, V N, additional, Romero-Gomez, P, additional, Ruoff, R S, additional, Sanford, R A, additional, Santamarina, J C, additional, Santillan, E F U, additional, Sathaye, K J, additional, Scheibe, T D, additional, Schonherr, M, additional, Sen, M K, additional, Senthilnathan, S, additional, Serkowski, J A, additional, Shafiei, M, additional, Shanahan, T M, additional, Shao, S, additional, Sheehan, B, additional, Sheikh, A H El, additional, Shi, Z, additional, Shovkun, I A, additional, Singh, G, additional, Singh, R, additional, Slottke, D T, additional, Sobolik, S, additional, Srinivasan, S, additional, Stadler, G, additional, Stauffer, P H, additional, Stockli, D F, additional, Stormont, J, additional, Strack, E A, additional, Strathmann, T J, additional, Suarez-Rivera, R, additional, Sun, Z, additional, Sun, Y, additional, Sun, A, additional, Sun, T, additional, Sweetser, J D, additional, Taha, M Reda, additional, Tang, H, additional, Tang, Y, additional, Tartakovsky, A M, additional, Tartakovsky, G D, additional, Tavakoli, R, additional, Tavener, S, additional, Tenney, C M, additional, Thomassen, D, additional, Tian, X, additional, Tran, V, additional, Trask, N, additional, Trevisan, L, additional, Truskett, T M, additional, Tsotsis, T T, additional, Turner, D Z, additional, Ureña-Benavides, E E, additional, Valocchi, A J, additional, Vohralik, M, additional, Wang, L, additional, Wang, W, additional, Wang, B, additional, Wang, W H, additional, Wang, Y, additional, Wen, B, additional, Werth, C J, additional, Wheeler, M, additional, White, D, additional, Wick, T, additional, Wietsma, T W, additional, Wildey, T, additional, Wilson, A, additional, Wilson, Jennifer, additional, Wolfe, W, additional, Worthen, A J, additional, Xiao, H, additional, Xue, Z, additional, Xue, G, additional, Yang, C, additional, Yang, X, additional, Yoon, H, additional, Yoon, K Y, additional, Yotov, I A, additional, Youl, A, additional, Youl, K, additional, Yu, G, additional, Zhang, L, additional, Zhang, C, additional, Zhang, R, additional, Zhen, T, additional, and Zhu, W, additional
- Published
- 2019
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7. Effects of grain size and small-scale bedform architecture on CO2 saturation from buoyancy-driven flow.
- Author
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Ni, Hailun, Bakhshian, Sahar, and Meckel, T. A.
- Subjects
BUOYANCY-driven flow ,GRAIN size ,PROPERTIES of fluids ,FLOW simulations ,INTERFACIAL tension ,BUOYANCY - Abstract
Small-scale (mm-dm scale) heterogeneity has been shown to significantly impact CO
2 migration and trapping. To investigate how and why different aspects of small-scale heterogeneity affect the amount of capillary trapping during buoyancy-driven upward migration of CO2 , we conducted modified invasion percolation simulations on heterogeneous domains. Realistic simulation domains are constructed by varying two important aspects of small-scale geologic heterogeneity: sedimentary bedform architecture and grain size contrast between the matrix and the laminae facies. Buoyancy-driven flow simulation runs cover 59 bedform architecture and 40 grain size contrast cases. Simulation results show that the domain effective CO2 saturation is strongly affected by both grain size and bedform architecture. At high grain size contrasts, bedforms with continuous ripple lamination at the cm scale tend to retain higher CO2 saturation than bedforms with discontinuous or cross lamination. In addition, the "extremely well sorted" grain sorting cases tend to have lower CO2 saturation than expected for cross-laminated domains. Finally, both a denser CO2 phase and greater interfacial tension increase CO2 saturation. Again, variation in fluid properties seems to have a greater effect on CO2 saturation for cross-laminated domains. This result suggests that differences in bedform architecture can impact how CO2 saturation values respond to other variables such as grain sorting and fluid properties. [ABSTRACT FROM AUTHOR]- Published
- 2023
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8. Characterizing the Effect of Capillary Heterogeneity on Multiphase Flow Pulsation in an Intermediate‐Scale Beadpack Experiment Using Time Series Clustering and Frequency Analysis
- Author
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Ni, Hailun, primary and Meckel, T. A., additional
- Published
- 2021
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9. Guard cells undergo constitutive and pressure-driven membrane turnover
- Author
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Meckel, T., Hurst, A. C., Thiel, G., and Homann, U.
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- 2005
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10. ERES (ER exit sites) and the “Secretory Unit Concept”
- Author
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LANGHANS, M., MECKEL, T., KRESS, A., LERICH, A., and ROBINSON, D. G.
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- 2012
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11. Upcycling of food industry side streams by basidiomycetes for production of a vegan protein source
- Author
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Ahlborn, J., Stephan, A., Meckel, T., Maheshwari, G., Rühl, M., Zorn, H., and Publica
- Abstract
Purpose Novel protein sources are urgently needed to meet the increasing protein demand of a continuously growing world population. This study is focused on the production of protein rich mushroom mycelia on industrial side streams. Methods Submerged propagation of mushrooms was carried out in shake flasks which contained agro-industrial side streams as the sole carbon source. The biomass obtained was analyzed for its crude protein, ash and fat content as well as for its fatty acid and amino acid profiles. Vitamin D2 production from ergosterol in the biomass was induced by UV-B irradiation and determined by HPLC-DAD. The share of fungal mycelium in the total biomass was determined by extraction and quantitation of ergosterol. Additionally, water and oil binding capacity (WBC and OBC) were evaluated. Results A screening of basidiomycetes grown on agro-industrial side streams indicated a fast growth of Pleurotus sapidus on apple pomace. After 4 days of cultivation, the biomass obtained from this mushroom-substrate combination contained 21% true protein in dry matter. In addition to proteins, the amounts of lipids (4%), ash (2%) and carbohydrates (74%) were quantitated. The dominating fatty and amino acids of Pleurotus sapidus grown on apple pomace were linoleic acid and glutamic acid/glutamine, respectively. Concentrations of up to 115 µg (g dry matter)−1 vitamin D2 were formed from ergosterol by UV-B irradiation. Ergosterol was used as a biomarker to monitor the amount of fungal content. Conclusion The nutritional value of agro-industrial side streams such as apple pomace can be upcycled by biotransformation with basidiomycetes.
- Published
- 2019
12. Author Correction: A method to generate small-scale, high-resolution sedimentary bedform architecture models representing realistic geologic facies
- Author
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Meckel, T. A., primary, Trevisan, L., additional, and Krishnamurthy, P. G., additional
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- 2018
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13. A method to generate small-scale, high-resolution sedimentary bedform architecture models representing realistic geologic facies
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Meckel, T. A., primary, Trevisan, L., additional, and Krishnamurthy, P. G., additional
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- 2017
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14. Possible function for virus encoded K+ channel Kcv in the replication of chlorella virus PBCV-1
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Mehmel M., Rothermel M., Meckel T., Van Etten J.L., Moroni A., and Thiel G.
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viruses - Abstract
The K+ channel Kcv is encoded by the chlorella virus PBCV-1. There is evidence that this channel plays an essential role in the replication of the virus, because both PBCV-1 plaque formation and Kcv channel activity in Xenopus oocytes have similar sensitivities to inhibitors. Here we report circumstantial evidence that the Kcv channel is important during virus infection. Recordings of membrane voltage in the host cells Chlorella NC64A reveal a membrane depolarization within the first few minutes of infection. This depolarization displays the same sensitivity to cations as Kcv conductance; depolarization also requires the intact membrane of the virion. Together these data are consistent with the idea that the virus carries functional K+ channels in the virion and inserts them into the host cell plasma membrane during infection.
- Published
- 2003
15. The short N-terminus is required for functional expression of the virus encoded miniature K+-channel Kcv
- Author
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Moroni A., Viscomi C., Sangiorgio V., Pagliuca C., Meckel T., Horvath F., Gazzarrini S., Valbuzzi P., Van Etten J.L., Difrancesco D., and Thiel G.
- Abstract
Kcv (K+ Chlorella virus) is a miniature virus-encoded K+ channel. Its predicted membraneporemembrane structure lacks a cytoplasmic C-terminus and it has a short 12 amino acid (aa) cytoplasmic N-terminus. Kcv forms a functional channel when expressed in human HEK 293 cells. Deletion of the 14 N-terminal aa results in no apparent differences in the subcellular location and expression level of the Kcv protein. However, the truncated protein does not induce a measurable current in transfected HEK 293 cells or Xenopus oocytes. We conclude that the N-terminus controls functional properties of the Kcv channel, but does not influence protein expression.
- Published
- 2002
16. Digital Rendering of Sedimentary-Relief Peels: Implications for Clastic Facies Characterization and Fluid Flow
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Meckel, T. A., primary
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- 2013
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17. Best Management Practices for subseabed geologic sequestration of carbon dioxide
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Smyth, R. C., primary and Meckel, T. A., additional
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- 2012
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18. Above-Zone Pressure Monitoring as a Surveillance Tool for Carbon Sequestration Projects
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Meckel, T. A., additional and Hovorka, S. D., additional
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- 2010
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19. Live cell imaging of repetitive DNA sequences via GFP-tagged polydactyl zinc finger proteins
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Lindhout, B. I., primary, Fransz, P., additional, Tessadori, F., additional, Meckel, T., additional, Hooykaas, P. J.J., additional, and van der Zaal, B. J., additional
- Published
- 2007
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20. Sediment compaction rates and subsidence in deltaic plains: numerical constraints and stratigraphic influences
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Meckel, T. A., primary, Ten Brink, U. S., additional, and Williams, S. J., additional
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- 2007
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21. Current subsidence rates due to compaction of Holocene sediments in southern Louisiana
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Meckel, T. A., primary, ten Brink, U. S., additional, and Williams, S. Jeffress, additional
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- 2006
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22. Influence of cumulative convergence on lithospheric thrust fault development and topography along the Australian-Pacific plate boundary south of New Zealand
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Meckel, T. A., primary, Mann, P., additional, Mosher, Sharon, additional, and Coffin, Millard F., additional
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- 2005
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23. Underthrusting at the Hjort Trench, Australian-Pacific plate boundary: Incipient subduction?
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Meckel, T. A., primary, Coffin, M. F., additional, Mosher, S., additional, Symonds, P., additional, Bernardel, G., additional, and Mann, P., additional
- Published
- 2003
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24. Maturing global CO2 storage resources on offshore continental margins to achieve 2DS emissions reductions.
- Author
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Ringrose, P. S. and Meckel, T. A.
- Subjects
- *
CARBON dioxide , *GREENHOUSE gas mitigation , *HYDROCARBONS , *RENEWABLE energy sources , *ENERGY consumption - Abstract
Most studies on CO2 emissions reduction strategies that address the 'two-degree scenario' (2DS) recognize a significant role for CCS. For CCS to be effective, it must be deployed globally on both existing and emerging energy systems. For nations with large-scale emissions, offshore geologic CO2 storage provides an attractive and efficient long-term strategy. While some nations are already developing CCS projects using offshore CO2 storage resources, most geographic regions have yet to begin. This paper demonstrates the geologic significance of global continental margins for providing broadly-equitable, geographically-relevant, and high-quality CO2 storage resources. We then use principles of pore-space utilization and subsurface pressure constraints together with analogs of historic industry well deployment rates to demonstrate how the required storage capacity can be developed as a function of time and technical maturity to enable the global deployment of offshore storage for facilitating 2DS. Our analysis indicates that 10–14 thousand CO2 injection wells will be needed globally by 2050 to achieve this goal. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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25. Impact of 3D capillary heterogeneity and bedform architecture at the sub-meter scale on CO 2 saturation for buoyant flow in clastic aquifers
- Author
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Meckel, T.
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- 2017
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26. Investigating Cellulose Binding of Peptides Derived from Carbohydrate Binding Module 1.
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Lill A, Herbst A, Langhans M, Paech S, Hamacher K, Biesalski M, Meckel T, and Schmitz K
- Abstract
Carbohydrate-binding modules (CBM) have emerged as useful tools for a wide range of tasks, including the use as purification tags or for cellulose fiber modification. For this purpose, the CBM needs to be attached to a target protein leading to large constructs. We investigated if short peptides from the carbohydrate binding site of CBMs can bind in a similar way as native, full-length CBMs to nanocrystalline cellulose (NCC) or cotton linter paper. We designed our cellulose-binding peptides to be less hydrophobic and shorter than those previously reported. Starting from the binding site of Cel7A-CBM1, we incorporated the essential amino acids involved in cellulose binding into our peptides. These peptides, as well as control peptides with scrambled sequences or a lack of essential amino acids, bound to cellulose with similar affinity as CBM regardless of their secondary structure, sequence, or hydrophobicity. This unspecific mode of cellulose binding displayed by the presented peptides may be exploited to functionalize cellulose-based biomaterials by means of peptide-conjugates.
- Published
- 2024
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27. Isotachophoresis with Oscillating Sample Zones to Control the Spatial Overlap of Co-focused Species.
- Author
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Gebhard F, Bonart H, Roy T, Meckel T, and Hardt S
- Abstract
Microfluidic isotachophoresis (ITP) is a powerful technique that can significantly increase the reaction rate of homogeneous chemical reactions by cofocusing reactants in a narrow sample zone. Correspondingly, ITP has been utilized to reduce the reaction time in various bioanalytical assays. However, in conventional ITP, it is hardly possible to control the reaction rate in real time, i.e., speeding up or slowing down a reaction on demand. Here, we experimentally demonstrate a new mode of ITP that allows the spatial overlap of two ITP zones to be precisely controlled over time, which is a crucial first step toward controlling reaction rates. Two nonreactive samples are initially focused and separated by a spacer using a DC electric field. By superimposing an oscillating field component with sufficiently high amplitude on the DC field, the spatial overlap of their concentration profiles is temporarily increased due to electromigration dispersion. The time-average of this overlap can be precisely controlled by varying the frequency and amplitude of the oscillation. We suggest that this scheme can be transferred to chemical reactions between ionic species with sufficiently different electrophoretic mobilities. Tuning the parameters of the oscillatory electric field should allow direct control of the corresponding reaction rate.
- Published
- 2024
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28. Chemical Gradients in Polymer-Modified Paper Sheets-Towards Single-Layer Biomimetic Soft Robots.
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Schäfer JL, Meckel T, Poppinga S, and Biesalski M
- Abstract
Biomimetic actuators are typically constructed as functional bi- or multilayers, where actuating and resistance layers together dictate bending responses upon triggering by environmental stimuli. Inspired by motile plant structures, like the stems of the false rose of Jericho ( Selaginella lepidophylla ), we introduce polymer-modified paper sheets that can act as soft robotic single-layer actuators capable of hygro-responsive bending reactions. A tailored gradient modification of the paper sheet along its thickness entails increased dry and wet tensile strength and allows at the same time for hygro-responsiveness. For the fabrication of such single-layer paper devices, the adsorption behavior of a cross-linkable polymer to cellulose fiber networks was first evaluated. By using different concentrations and drying procedures fine-tuned polymer gradients throughout the thickness can be achieved. Due to the covalent cross-linking of polymer with fibers, these paper samples possess significantly increased dry and wet tensile strength properties. We furthermore investigated these gradient papers with respect to a mechanical deflection during humidity cycling. The highest humidity sensitivity is achieved using eucalyptus paper with a grammage of 150 g m
-2 modified with the polymer dissolved in IPA (~13 wt%) possessing a polymer gradient. Our study presents a straightforward approach for the design of novel hygroscopic, paper-based single-layer actuators, which have a high potential for diverse soft robotic and sensor applications.- Published
- 2023
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29. MeCP2-induced heterochromatin organization is driven by oligomerization-based liquid-liquid phase separation and restricted by DNA methylation.
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Zhang H, Romero H, Schmidt A, Gagova K, Qin W, Bertulat B, Lehmkuhl A, Milden M, Eck M, Meckel T, Leonhardt H, and Cardoso MC
- Subjects
- Chromatin, DNA, DNA Methylation, Humans, Heterochromatin, Rett Syndrome genetics
- Abstract
Heterochromatin is the highly compacted form of chromatin with various condensation levels hallmarked by high DNA methylation. MeCP2 is mostly known as a DNA methylation reader but has also been reported as a heterochromatin organizer. Here, we combine liquid-liquid phase separation (LLPS) analysis and single-molecule tracking with quantification of local MeCP2 concentrations in vitro and in vivo to explore the mechanism of MeCP2-driven heterochromatin organization and dynamics. We show that MeCP2 alone forms liquid-like spherical droplets via multivalent electrostatic interactions and with isotropic mobility. Crowded environments and DNA promote MeCP2 LLPS and slow down MeCP2 mobility. DNA methylation, however, restricts the growth of heterochromatin compartments correlating with immobilization of MeCP2. Furthermore, MeCP2 self-interaction is required for LLPS and is disrupted by Rett syndrome mutations. In summary, we are able to model the heterochromatin compartmentalization as well as MeCP2 concentration and heterogeneous motion in the minimal in vitro system.
- Published
- 2022
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30. Modulation of Differentiation and Bone Resorbing Activity of Human (Pre-) Osteoclasts After X-Ray Exposure.
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Eckert D, Rapp F, Tsedeke AT, Kraft D, Wente I, Molendowska J, Basheer S, Langhans M, Meckel T, Friedrich T, Donaubauer AJ, Becker I, Frey B, and Fournier C
- Subjects
- Cytokines metabolism, Humans, X-Rays, Bone Resorption metabolism, Osteoclasts metabolism
- Abstract
Low-dose radiotherapy (LD-RT) is a local treatment option for patients with chronic degenerative and inflammatory diseases, in particular musculoskeletal diseases. Despite reported analgesic and anti-inflammatory effects, cellular and molecular mechanisms related to osteoimmunological effects are still elusive. Here we test the hypothesis that X-irradiation inhibits the differentiation of precursor osteoclasts into mature osteoclasts (mOC) and their bone resorbing activity. Circulating monocytes from healthy donors were isolated and irradiated after attachment with single or fractionated X-ray doses, comparable to an LD-RT treatment scheme. Then monocytes underwent ex vivo differentiation into OC during cultivation up to 21 days, under conditions mimicking the physiological microenvironment of OC on bone. After irradiation, apoptotic frequencies were low, but the total number of OC precursors and mOC decreased up to the end of the cultivation period. On top, we observed an impairment of terminal differentiation, i.e. a smaller fraction of mOC, reduced resorbing activity on bone, and release of collagen fragments. We further analyzed the effect of X-irradiation on multinucleation, resulting from the fusion of precursor OC, which occurs late during OC differentiation. At 21 days after exposure, the observation of smaller cellular areas and a reduced number of nuclei per mOC suggest an impaired fusion of OC precursors to form mOC. Before, at 14 days, the nuclear translocation of Nuclear Factor Of Activated T Cells 1 (NFATc1), a master regulator of osteoclast differentiation and fusion, was decreased. In first results, obtained in the frame of a longitudinal LD-RT study, we previously reported a pain-relieving effect in patients. However, in a subgroup of patients suffering from Calcaneodynia or Achillodynia, we did not observe a consistent decrease of established blood markers for resorption and formation of bone, or modified T cell subtypes involved in regulating these processes. To assess the relevance of changes in bone metabolism for other diseases treated with LD-RT will be subject of further studies. Taken together, we observed that in vitro X-irradiation of monocytes results in an inhibition of the differentiation into bone-resorbing OC and a concomitant reduction of resorbing activity. The detected reduced NFATc1 signaling could be one underlying mechanism., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer MS declared a shared affiliation with the authors ML and TM to the handling editor at the time of review., (Copyright © 2022 Eckert, Rapp, Tsedeke, Kraft, Wente, Molendowska, Basheer, Langhans, Meckel, Friedrich, Donaubauer, Becker, Frey and Fournier.)
- Published
- 2022
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31. Illuminating a Dark Kinase: Structure-Guided Design, Synthesis, and Evaluation of a Potent Nek1 Inhibitor and Its Effects on the Embryonic Zebrafish Pronephros.
- Author
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Baumann G, Meckel T, Böhm K, Shih YH, Dickhaut M, Reichardt T, Pilakowski J, Pehl U, and Schmidt B
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- Animals, Embryo, Nonmammalian enzymology, Polycystic Kidney Diseases enzymology, Polycystic Kidney Diseases pathology, Pronephros embryology, Pronephros enzymology, Zebrafish, Drug Design, Embryo, Nonmammalian drug effects, NIMA-Related Kinase 1 antagonists & inhibitors, Polycystic Kidney Diseases drug therapy, Pronephros drug effects, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors pharmacology
- Abstract
NIMA-related kinase 1 (Nek1) has lately garnered attention for its widespread function in ciliogenesis, apoptosis, and the DNA-damage response. Despite its involvement in various diseases and its potential as a cancer drug target, no directed medicinal chemistry efforts toward inhibitors against this dark kinase are published. Here, we report the structure-guided design of a potent small-molecule Nek1 inhibitor, starting from a scaffold identified by kinase cross-screening analysis. Seven lead compounds were identified in silico and evaluated for their inhibitory activity. The top compound, 10f , was further profiled for efficacy, toxicity, and bioavailability in a zebrafish polycystic kidney disease model. Administration of 10f caused the expansion of fluorescence-labeled proximal convoluted tubules, supporting our hypothesis that Nek1-inhibition causes cystic kidneys in zebrafish embryos. Compound 10f displayed insignificant inhibition in 48 of 50 kinases in a selectivity test panel. The findings provide a powerful tool to further elucidate the function and pharmacology of this neglected kinase.
- Published
- 2022
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32. Design, synthesis and biological evaluation of novel aminopyrazole- and 7-azaindole-based Nek1 inhibitors and their effects on zebrafish kidney development.
- Author
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Pilakowski J, Baumann G, Shih YH, Meckel T, and Schmidt B
- Subjects
- Animals, Dose-Response Relationship, Drug, Indoles chemical synthesis, Indoles chemistry, Kidney growth & development, Kidney metabolism, Molecular Structure, NIMA-Related Kinase 1 metabolism, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors chemistry, Pyrazoles chemical synthesis, Pyrazoles chemistry, Structure-Activity Relationship, Zebrafish, Drug Design, Indoles pharmacology, Kidney drug effects, NIMA-Related Kinase 1 antagonists & inhibitors, Protein Kinase Inhibitors pharmacology, Pyrazoles pharmacology
- Abstract
NIMA-related protein kinase Nek1 is crucially involved in cell cycle regulation, DNA repair and microtubule regulation and dysfunctions of Nek1 play key roles in amyotrophic lateral sclerosis (ALS), polycystic kidney disease (PKD) and several types of radiotherapy resistant cancer. Targeting of Nek1 could reveal a new class of radiosensitizing substances and provide useful tools to better understand the aforementioned diseases. In this report we explore substituted aminopyrazoles and 7-azaindoles as potent inhibitors for the Nek1 kinase domain and examine their effect on kidney organogenesis in Danio rerio., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
33. Reducing Unspecific Protein Adsorption in Microfluidic Papers Using Fiber-Attached Polymer Hydrogels.
- Author
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von Stockert AR, Luongo A, Langhans M, Brandstetter T, Rühe J, Meckel T, and Biesalski M
- Subjects
- Adsorption, Hydrogels, Paper, Microfluidics, Polymers
- Abstract
Microfluidic paper combines pump-free water transport at low cost with a high degree of sustainability, as well as good availability of the paper-forming cellulosic material, thus making it an attractive candidate for point-of-care (POC) analytics and diagnostics. Although a number of interesting demonstrators for such paper devices have been reported to date, a number of challenges still exist, which limit a successful transfer into marketable applications. A strong limitation in this respect is the (unspecific) adsorption of protein analytes to the paper fibers during the lateral flow assay. This interaction may significantly reduce the amount of analyte that reaches the detection zone of the microfluidic paper-based analytical device (µPAD), thereby reducing its overall sensitivity. Here, we introduce a novel approach on reducing the nonspecific adsorption of proteins to lab-made paper sheets for the use in µPADs. To this, cotton linter fibers in lab-formed additive-free paper sheets are modified with a surrounding thin hydrogel layer generated from photo-crosslinked, benzophenone functionalized copolymers based on poly-(oligo-ethylene glycol methacrylate) (POEGMA) and poly-dimethyl acrylamide (PDMAA). This, as we show in tests similar to lateral flow assays, significantly reduces unspecific binding of model proteins. Furthermore, by evaporating the transport fluid during the microfluidic run at the end of the paper strip through local heating, model proteins can almost quantitatively be accumulated in that zone. The possibility of complete, almost quantitative protein transport in a µPAD opens up new opportunities to significantly improve the signal-to-noise (S/N) ratio of paper-based lateral flow assays.
- Published
- 2021
- Full Text
- View/download PDF
34. Porosity Centrifuge: Determination of Pore Sizes of Swellable Porous Materials under Hypergravity.
- Author
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Postulka N, Meckel T, and Biesalski M
- Abstract
Porous materials are ubiquitous and essential for many processes in nature as well as in industry, and the need to produce them from renewable materials will definitely increase. A prominent example for such a fully recyclable and biogenic porous material is paper, a material that contains macropores formed in between the fibers as well as a large distribution of much finer pores on and within the fiber walls. While the determination of pore sizes is of central importance for the characterization of such materials, their determination is usually only possible with complex methodologies. The determination of pore sizes in the context of water has remained largely unsolved to date, in particular, if water-swellable materials are considered. Here, we introduce a completely new way of determining pore sizes of materials even under swelling conditions. Using a centrifugal device and studying the imbibition of water into paper at various centrifugal forces that oppose the capillary forces, we can access the mean pore size of different paper materials in an experimentally simple fashion. In addition, we can show that the pore size values obtained with our "centrifugal porosimetry" are consistent with the values obtained using other methods, usually much more involved methods. For this purpose, we measure well-characterized translucent macroporous materials using water, ranging from simple glass capillaries to standard filters and nitrocellulose membranes.
- Published
- 2021
- Full Text
- View/download PDF
35. Diazo-Based Copolymers for the Wet Strength Improvement of Paper Based on Thermally Induced CH-Insertion Cross-Linking.
- Author
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Schölch S, Schäfer JL, Meckel T, Brandstetter T, Biesalski M, and Rühe J
- Subjects
- Hydrophobic and Hydrophilic Interactions, Tensile Strength, Cellulose, Water
- Abstract
We present an alternative to commonly used, but from an environmental point of view, problematic wet strength agents, which are usually added to paper to prevent a loss of mechanical stability and finally disintegrate when they get into contact with water. To this end, diazoester-containing copolymers are generated, which are coated onto paper and by heating to 110-160 °C for short periods of time become activated and form carbene intermediates, which undergo a CH-insertion cross-linking reaction. The process leads to a simultaneous cross-linking of the polymer and its attachment to the cellulose substrate. The immobilization process of copolymers consisting of a hydrophilic matrix based on N , N -dimethylacrylamide and a diazoester-based comonomer to a cellulose model surface and to laboratory-engineered, fibrous paper substrates is investigated as a function of time, temperature, and cross-linker composition. The distribution of the polymer in the fiber network is studied using confocal fluorescence microscopy. Finally, the tensile properties of modified wet and dry eucalyptus sulfate papers are measured to demonstrate the strong effect of the thermally cross-linked copolymers on the wet strength of paper substrates. Initial experiments show that the tensile indices of the modified and wetted paper samples are up to 50 times higher compared to the values measured for unmodified samples. When dry and wet papers coated with the above-described wetting agents are compared, relative wet strengths of over 30% are observed.
- Published
- 2021
- Full Text
- View/download PDF
36. Toward Fabrication of Bioactive Papers: Covalent Immobilization of Peptides and Proteins.
- Author
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Liebich VJ, Avrutina O, Habermann J, Hillscher LM, Langhans M, Meckel T, Biesalski M, and Kolmar H
- Subjects
- Reproducibility of Results, Transglutaminases, Bacterial Proteins, Peptides
- Abstract
Herein, we report a novel two-step method for the covalent, site-directed, and efficient immobilization of proteins on lab-made paper sheets. First, paper fibers were modified with a peptidic anchor comprising enzyme recognition motifs. Four different conjugation strategies for peptide immobilization were evaluated with respect to reproducibility and fiber loading efficiency. After manufacturing of the peptide-preconditioned paper, oriented conjugation of the model protein tGFP containing a C-terminal recognition sequence for either sortase A or microbial transglutaminase was assessed semiquantitatively by fluorescence measurement and inspected by confocal laser scanning microscopy (CLSM). The two enzymes utilized for protein conjugation used the same oligoglycine peptide anchor, and both proved to be suitable for controlled oriented linkage of substrate proteins at physiological conditions.
- Published
- 2021
- Full Text
- View/download PDF
37. Storage of Carbon Dioxide in Saline Aquifers: Physicochemical Processes, Key Constraints, and Scale-Up Potential.
- Author
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Ringrose PS, Furre AK, Gilfillan SMV, Krevor S, Landrø M, Leslie R, Meckel T, Nazarian B, and Zahid A
- Subjects
- Chemical Phenomena, Climate, Humans, Carbon Dioxide, Groundwater
- Abstract
CO
2 storage in saline aquifers offers a realistic means of achieving globally significant reductions in greenhouse gas emissions at the scale of billions of tonnes per year. We review insights into the processes involved using well-documented industrial-scale projects, supported by a range of laboratory analyses, field studies, and flow simulations. The main topics we address are ( a ) the significant physicochemical processes, ( b ) the factors limiting CO2 storage capacity, and ( c ) the requirements for global scale-up.Although CO2 capture and storage (CCS) technology can be considered mature and proven, it requires significant and rapid scale-up to meet the objectives of the Paris Climate Agreement. The projected growth in the number of CO2 injection wells required is significantly lower than the historic petroleum industry drill rates, indicating that decarbonization via CCS is a highly credible and affordable ambition for modern human society. Several technology developments are needed to reduce deployment costs and to stimulate widespread adoption of this technology, and these should focus on demonstration of long-term retention and safety of CO2 storage and development of smart ways of handling injection wells and pressure, cost-effective monitoring solutions, and deployment of CCS hubs with associated infrastructure.- Published
- 2021
- Full Text
- View/download PDF
38. Carbohydrate binding module-fused antibodies improve the performance of cellulose-based lateral flow immunoassays.
- Author
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Elter A, Bock T, Spiehl D, Russo G, Hinz SC, Bitsch S, Baum E, Langhans M, Meckel T, Dörsam E, Kolmar H, and Schwall G
- Subjects
- Biocompatible Materials, Chorionic Gonadotropin chemistry, Clostridium thermocellum immunology, Humans, Immunoglobulin Fragments chemistry, Immunoglobulin G chemistry, Point-of-Care Systems, Protein Binding, SARS-CoV-2 immunology, Urinalysis, Antibodies, Viral analysis, COVID-19 diagnosis, COVID-19 Serological Testing methods, Carbohydrates chemistry, Collodion chemistry, Immunoassay methods
- Abstract
Since the pandemic outbreak of Covid-19 in December 2019, several lateral flow assay (LFA) devices were developed to enable the constant monitoring of regional and global infection processes. Additionally, innumerable lateral flow test devices are frequently used for determination of different clinical parameters, food safety, and environmental factors. Since common LFAs rely on non-biodegradable nitrocellulose membranes, we focused on their replacement by cellulose-composed, biodegradable papers. We report the development of cellulose paper-based lateral flow immunoassays using a carbohydrate-binding module-fused to detection antibodies. Studies regarding the protein binding capacity and potential protein wash-off effects on cellulose paper demonstrated a 2.7-fold protein binding capacity of CBM-fused antibody fragments compared to the sole antibody fragment. Furthermore, this strategy improved the spatial retention of CBM-fused detection antibodies to the test area, which resulted in an enhanced sensitivity and improved overall LFA-performance compared to the naked detection antibody. CBM-assisted antibodies were validated by implementation into two model lateral flow test devices (pregnancy detection and the detection of SARS-CoV-2 specific antibodies). The CBM-assisted pregnancy LFA demonstrated sensitive detection of human gonadotropin (hCG) in synthetic urine and the CBM-assisted Covid-19 antibody LFA was able to detect SARS-CoV-2 specific antibodies present in serum. Our findings pave the way to the more frequent use of cellulose-based papers instead of nitrocellulose in LFA devices and thus potentially improve the sustainability in the field of POC diagnostics.
- Published
- 2021
- Full Text
- View/download PDF
39. Multivalent dextran hybrids for efficient cytosolic delivery of biomolecular cargoes.
- Author
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Becker B, Englert S, Schneider H, Yanakieva D, Hofmann S, Dombrowsky C, Macarrón Palacios A, Bitsch S, Elter A, Meckel T, Kugler B, Schirmacher A, Avrutina O, Diederichsen U, and Kolmar H
- Subjects
- Cell-Penetrating Peptides chemical synthesis, Cell-Penetrating Peptides chemistry, Cytosol chemistry, Dextrans chemistry, Fluorescent Dyes chemistry, HeLa Cells, Humans, Molecular Structure, Optical Imaging, Tumor Cells, Cultured, Cell-Penetrating Peptides metabolism, Cytosol metabolism, Dextrans metabolism, Fluorescent Dyes metabolism
- Abstract
The development of novel biotherapeutics based on peptides and proteins is often limited to extracellular targets, because these molecules are not able to reach the cytosol. In recent years, several approaches were proposed to overcome this limitation. A plethora of cell-penetrating peptides (CPPs) was developed for cytoplasmic delivery of cell-impermeable cargo molecules. For many CPPs, multimerization or multicopy arrangement on a scaffold resulted in improved delivery but also higher cytotoxicity. Recently, we introduced dextran as multivalent, hydrophilic polysaccharide scaffold for multimerization of cell-targeting cargoes. Here, we investigated covalent conjugation of a CPP to dextran in multiple copies and assessed the ability of resulted molecular hybrid to enter the cytoplasm of mammalian cells without largely compromising cell viability. As a CPP, we used a novel, low-toxic cationic amphiphilic peptide L17E derived from M-lycotoxin. Here, we show that cell-penetrating properties of L17E are retained upon multivalent covalent linkage to dextran. Dextran-L17E efficiently mediated cytoplasmic translocation of an attached functional peptide and a peptide nucleic acid (PNA). Moreover, a synthetic route was established to mask the lysine side chains of L17E with a photolabile protecting group thus opening avenues for light-triggered activation of cellular uptake., (© 2021 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.)
- Published
- 2021
- Full Text
- View/download PDF
40. Entrapment of Hydrophobic Biocides into Cellulose Acetate Nanoparticles by Nanoprecipitation.
- Author
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Cordt C, Meckel T, Geissler A, and Biesalski M
- Abstract
This contribution reports an efficient method for the production and use of biocide-loaded cellulose acetate nanoparticles. As well-known model biocides 4-Hexylresorcinol and Triclosan were used for in situ nanoparticle loading during a nanoprecipitation process. We show that the nanoparticle size can be well-controlled by variation of the cellulose acetate concentration during nanoprecipitation. Apart from strong evidence suggesting cellulose acetate particle formation according to a nucleation-aggregation mechanism, we further show that the biocide loading of the particles occurs by a diffusion process and not via co-precipitation. The quantity of particle loading was analyzed by
1 H-NMR spectroscopy of re-dissolved nanoparticles, and it was observed that a decisive factor for high packaging efficiency is the use of a biocide with low water solubility and high hydrophobicity. SEM studies showed no influence on the particle morphology or size by both biocides 4-Hexylresorcinol and Triclosan. Finally, an aqueous nanoparticle dispersion can be coated onto model paper sheets to yield pronounced antimicrobial surface-properties. Nanoparticles loaded with the biocide Triclosan showed a high antimicrobial activity against Bacillus subtilis , a cellulase producing bacteria, if applied to model paper substrates, even at extremely low coating weights of 1-5 g/m2 , respectively. Additional long-term efficacy renders these nanoparticles ideal for various applications.- Published
- 2020
- Full Text
- View/download PDF
41. Analysis of free chlorine in aqueous solution at very low concentration with lateral flow tests.
- Author
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Schwenke KU, Spiehl D, Krauße M, Riedler L, Ruppenthal A, Villforth K, Meckel T, Biesalski M, Rupprecht D, and Schwall G
- Abstract
Test strips are convenient tools for rapid, semi-quantitative analysis of a variety of parameters by dipping them for a few seconds in a sample solution followed by a simple colorimetric read-out. Their sensitivity is mainly determined by the reactivity of the test dyes on the reaction zone and is not sufficient for some applications. The detection limit of commercially available free chlorine test strips, for example, is at present not low enough to confirm the absence of this analyte as disinfectant in rinsing solutions after disinfection or to control required residual amounts of chlorine in drinking water. Therefore, we developed a user-friendly lateral flow test which is capable to detect very low amounts of free chlorine. The latter relies on a larger sample volume passing the reaction zone as compared to simple dip test strips. An amount of as low as 0.05 ppm chlorine can, however, only be detected if oxidation stable flow test substrates are used. The eventually developed flow test reaches a 10x higher sensitivity than a commercial dip test. The result is obtained within 4-5 min flow time, whereby no action is required by the user during this analysis time.
- Published
- 2019
- Full Text
- View/download PDF
42. Light-Controlled Chemoenzymatic Immobilization of Proteins towards Engineering of Bioactive Papers.
- Author
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Hilberg V, Avrutina O, Ebenig A, Yanakieva D, Meckel T, Biesalski M, and Kolmar H
- Subjects
- Amides chemistry, Aminoacyltransferases chemistry, Bacterial Proteins chemistry, Biocatalysis, Cycloaddition Reaction, Cysteine Endopeptidases chemistry, Fluorescent Dyes chemistry, Immobilized Proteins chemistry, Immobilized Proteins metabolism, Microscopy, Confocal, Peptides analysis, Peptides chemistry, Point-of-Care Systems, Stereoisomerism, Aminoacyltransferases metabolism, Bacterial Proteins metabolism, Cysteine Endopeptidases metabolism, Light, Paper
- Abstract
Efficient and reliable methods for the generation of bioactive papers are of growing interest in relation to point-of-care testing devices that do not require extensive analytical equipment. Herein, we report the immobilization of functional proteins on paper fibers using a modular chemoenzymatic approach. The synthetic strategy relies on a combination of highly efficient spatially controllable photo-triggered cycloaddition followed by site-specific sortase A-catalyzed transamidation. This site-directed and regiospecific method has allowed unidirectional and covalent immobilization of several proteins displaying different functional properties, with ramifications for application in paper-based diagnostics., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2019
- Full Text
- View/download PDF
43. Combining Wax Printing with Hot Embossing for the Design of Geometrically Well-Defined Microfluidic Papers.
- Author
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Postulka N, Striegel A, Krauße M, Mager D, Spiehl D, Meckel T, Worgull M, and Biesalski M
- Abstract
A simple, efficient, and repeatable combination of wax printing and hot embossing is reported. This combination yields microfluidic channels in paper, where fluid transport driven by paper-intrinsic capillary forces takes place inside the noncompressed areas, whereas embossed and wax-bonded areas serve as hydrophobic barriers laterally confining the fluid flow. Lab-made paper sheets first coated with a hydrophobic wax were hot-embossed with a tailor-made metal stamp. Both paper-intrinsic (e.g., grammage, fiber type) and paper-extrinsic parameters (e.g., embossing force) were studied for their influence on the geometry of the embossed structures and the resulting redistribution of the wax within the paper matrix. Embossing of wax-printed paper at temperatures above the wax melting point was completed within 15 s. Cotton linters papers required higher embossing forces than eucalyptus papers, which can be explained by their different intrinsic mechanical properties. In summary, both paper-intrinsic and paper-extrinsic parameters were found to have strong impact on resolution and reproducibility of the channels. All in all, the approach yields microfluidic channels in a fast and robust and reproducible manner with comparably low constrains on the precision of manufacturing parameters, such as embossing time, force, or temperature. Most importantly, embossing greatly reduces the lateral spreading of the wax as seen with melting approaches and therefore allows for a much higher feature density than the latter.
- Published
- 2019
- Full Text
- View/download PDF
44. Generation of Potent Anti-HER1/2 Immunotoxins by Protein Ligation Using Split Inteins.
- Author
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Pirzer T, Becher KS, Rieker M, Meckel T, Mootz HD, and Kolmar H
- Subjects
- ADP Ribose Transferases pharmacology, Animals, Antineoplastic Agents, Immunological metabolism, Antineoplastic Agents, Immunological pharmacology, Bacterial Toxins pharmacology, Breast Neoplasms drug therapy, CHO Cells, Cell Line, Tumor, Cricetulus, ErbB Receptors antagonists & inhibitors, Escherichia coli genetics, Exotoxins pharmacology, Female, Humans, Immunotoxins pharmacology, Protein Engineering, Protein Splicing, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins pharmacology, Ribosome Inactivating Proteins, Type 1 genetics, Ribosome Inactivating Proteins, Type 1 pharmacology, Trastuzumab pharmacology, Virulence Factors pharmacology, Pseudomonas aeruginosa Exotoxin A, ADP Ribose Transferases genetics, Bacterial Toxins genetics, Exotoxins genetics, Immunotoxins genetics, Inteins, Pseudomonas genetics, Receptor, ErbB-2 antagonists & inhibitors, Trastuzumab genetics, Virulence Factors genetics
- Abstract
Cell targeting protein toxins have gained increasing interest for cancer therapy aimed at increasing the therapeutic window and reducing systemic toxicity. Because recombinant expression of immunotoxins consisting of a receptor-binding and a cell-killing moiety is hampered by their high toxicity in a eukaryotic production host, most applications rely on recombinant production of fusion proteins consisting of an antibody fragment and a protein toxin in bacterial hosts such as Escherichia coli ( E. coli). These fusions often lack beneficial properties of whole antibodies like extended serum half-life or efficient endocytic uptake via receptor clustering. Here, we describe the production of full-length antibody immunotoxins using self-splicing split inteins. To this end, the short (11 amino acids) N-terminal intein part of the artificially designed split intein M86, a derivative of the Ssp DnaB intein, was recombinantly fused to the heavy chain of trastuzumab, a human epidermal growth factor receptor 2 (HER2) receptor targeting antibody and to a nanobody-Fc fusion targeting the HER1 receptor, respectively. Both antibodies were produced in Expi293F cells. The longer C-terminal counterpart of the intein was genetically fused to the protein toxins gelonin or Pseudomonas Exotoxin A, respectively, and expressed in E. coli via fusion to maltose binding protein. Using optimized in vitro splicing conditions, we were able to generate a set of specific and potent immunotoxins with IC
50 values in the mid- to subpicomolar range.- Published
- 2018
- Full Text
- View/download PDF
45. Ionizing Radiation Induces Morphological Changes and Immunological Modulation of Jurkat Cells.
- Author
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Voos P, Fuck S, Weipert F, Babel L, Tandl D, Meckel T, Hehlgans S, Fournier C, Moroni A, Rödel F, and Thiel G
- Subjects
- Cell Adhesion radiation effects, Humans, Integrin beta1 genetics, Interferon-gamma genetics, Interferon-gamma immunology, Interleukin-2 genetics, Interleukin-2 immunology, Interleukin-2 Receptor alpha Subunit genetics, Monocytes radiation effects, Jurkat Cells immunology, Jurkat Cells radiation effects, Lymphocyte Activation radiation effects, Radiation, Ionizing
- Abstract
Impairment or stimulation of the immune system by ionizing radiation (IR) impacts on immune surveillance of tumor cells and non-malignant cells and can either foster therapy response or side effects/toxicities of radiation therapy. For a better understanding of the mechanisms by which IR modulates T-cell activation and alters functional properties of these immune cells, we exposed human immortalized Jurkat cells and peripheral blood lymphocytes (PBL) to X-ray doses between 0.1 and 5 Gy. This resulted in cellular responses, which are typically observed also in naïve T-lymphocytes in response of T-cell receptor immune stimulation or mitogens. These responses include oscillations of cytosolic Ca
2+ , an upregulation of CD25 surface expression, interleukin-2 and interferon-γ synthesis, elevated expression of Ca2+ sensitive K+ channels and an increase in cell diameter. The latter was sensitive to inhibition by the immunosuppressant cyclosporine A, Ca2+ buffer BAPTA-AM, and the CDK1-inhibitor RO3306, indicating the involvement of Ca2+ -dependent immune activation and radiation-induced cell cycle arrest. Furthermore, on a functional level, Jurkat and PBL cell adhesion to endothelial cells was increased upon radiation exposure and was highly dependent on an upregulation of integrin beta-1 expression and clustering. In conclusion, we here report that IR impacts on immune activation and functional properties of T-lymphocytes that may have implications in both toxic effects and treatment response to combined radiation and immune therapy in cancer patients.- Published
- 2018
- Full Text
- View/download PDF
46. Parallel assembly of actin and tropomyosin, but not myosin II, during de novo actin filament formation in live mice.
- Author
-
Masedunskas A, Appaduray MA, Lucas CA, Lastra Cagigas M, Heydecker M, Holliday M, Meiring JCM, Hook J, Kee A, White M, Thomas P, Zhang Y, Adelstein RS, Meckel T, Böcking T, Weigert R, Bryce NS, Gunning PW, and Hardeman EC
- Subjects
- Actin Cytoskeleton genetics, Actins genetics, Animals, Female, Male, Mice, Mice, Inbred C57BL, Myosin Heavy Chains, Nonmuscle Myosin Type IIA genetics, Protein Binding, Secretory Vesicles genetics, Secretory Vesicles metabolism, Tropomyosin genetics, Actin Cytoskeleton metabolism, Actins metabolism, Nonmuscle Myosin Type IIA metabolism, Tropomyosin metabolism
- Abstract
Many actin filaments in animal cells are co-polymers of actin and tropomyosin. In many cases, non-muscle myosin II associates with these co-polymers to establish a contractile network. However, the temporal relationship of these three proteins in the de novo assembly of actin filaments is not known. Intravital subcellular microscopy of secretory granule exocytosis allows the visualisation and quantification of the formation of an actin scaffold in real time, with the added advantage that it occurs in a living mammal under physiological conditions. We used this model system to investigate the de novo assembly of actin, tropomyosin Tpm3.1 (a short isoform of TPM3) and myosin IIA (the form of non-muscle myosin II with its heavy chain encoded by Myh9 ) on secretory granules in mouse salivary glands. Blocking actin polymerization with cytochalasin D revealed that Tpm3.1 assembly is dependent on actin assembly. We used time-lapse imaging to determine the timing of the appearance of the actin filament reporter LifeAct-RFP and of Tpm3.1-mNeonGreen on secretory granules in LifeAct-RFP transgenic, Tpm3.1-mNeonGreen and myosin IIA-GFP (GFP-tagged MYH9) knock-in mice. Our findings are consistent with the addition of tropomyosin to actin filaments shortly after the initiation of actin filament nucleation, followed by myosin IIA recruitment., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)
- Published
- 2018
- Full Text
- View/download PDF
47. Lipid-rafts remain stable even after ionizing radiation induced disintegration of β1 integrin containing focal adhesions.
- Author
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Babel L, Kruse L, Bump S, Langhans M, and Meckel T
- Subjects
- Humans, Membrane Microdomains physiology, Focal Adhesions metabolism, Integrin beta1 metabolism, Membrane Microdomains radiation effects, Radiation, Ionizing
- Abstract
Objective: Adhesion of cells to the extracellular matrix is facilitated by integrin receptors. We recently found that a nanoscale organization of plasma membrane located integrins containing the β1 subunit is responsible for an enhanced radio-resistance in 3D cultured cells over cells grown in 2D. While ionizing radiation is known to have broad effects on the lipid composition of the plasma membrane and their organization in lipid-rafts, it is not clear whether the effects of ionizing radiation on the nanoscale clustering of integrins is lipid-raft dependent., Results: Using single molecule microscopy we can show that β1 integrins colocalize with cholesterol in lipid-rafts. Ionizing radiation, as an extrinsic stressor, causes the separation of β1 integrins from cholesterol lipid raft suggesting that the effects of ionizing radiation on the clustering of β1 integrins are lipid-raft independent.
- Published
- 2017
- Full Text
- View/download PDF
48. Direct evidence for cell adhesion-mediated radioresistance (CAM-RR) on the level of individual integrin β1 clusters.
- Author
-
Babel L, Grunewald M, Lehn R, Langhans M, and Meckel T
- Subjects
- Animals, Cells, Cultured, Embryo, Mammalian metabolism, Embryo, Mammalian radiation effects, Extracellular Matrix, Fibroblasts metabolism, Fibroblasts radiation effects, Mice, Signal Transduction, Cell Adhesion radiation effects, Embryo, Mammalian pathology, Fibroblasts pathology, Integrin beta1 metabolism, Radiation Tolerance, Radiation, Ionizing
- Abstract
The cellular interaction with the extracellular matrix (ECM) modulates many key processes such as proliferation, migration, differentiation and survival. In addition, cells cultured under 3D conditions in presence of an ECM display a marked radioresistance towards ionizing radiation (IR) in comparison to conventionally 2D cultured cells. This process, also known as "cell-adhesion-mediated-radio-resistance" (CAM-RR), has been linked to the chromatin structure that differs between cells cultured on stiff surfaces versus cell grown on soft planar supports or in 3D environments. As integrins are the key mediators of cell adhesion and mechanosensing, they originate the molecular signalling towards chromatin remodelling in response to a cell's microenvironment. We aimed to investigate this molecular origin that leads to CAM-RR by investigating the distribution of integrins at the single molecule level and show that cells cultured in 2D keep a lower fraction of integrin β1 in clusters and maintain a less defined cluster status than 3D cultured cells. Upon X-irradiation this nanoscale distribution of integrin β1 is disturbed at much lower dosages in 2D versus 3D cultured cells. Radioresistance is thus linked to the ability to maintain a well defined organization of integrins in clusters, making integrin distribution a potential drug target for radiosensitization.
- Published
- 2017
- Full Text
- View/download PDF
49. Improved cell adhesion under shear stress in PDMS microfluidic devices.
- Author
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Siddique A, Meckel T, Stark RW, and Narayan S
- Subjects
- Adsorption, Animals, COS Cells, Cell Adhesion, Cell Proliferation, Chlorocebus aethiops, Collagen chemistry, Microscopy, Atomic Force, Oxygen chemistry, Propylamines chemistry, Shear Strength, Silanes chemistry, Stress, Mechanical, Surface Properties, Wettability, Dimethylpolysiloxanes chemistry, Lab-On-A-Chip Devices, Nylons chemistry
- Abstract
Microfluidic systems based on polydimethylsiloxane (PDMS) provide a versatile platform to study the mechanoresponse of cells in vitro. Under a shear flow, however, the stability of cells that were grown on physically adsorbed proteins is short lived, which limits long-term cell studies. To address this issue, we used (3-Aminopropyl)triethoxysilane (APTES) as a linker between PDMS and collagen. In micro-channels that were modified with APTES-anchored collagen, fibroblast cells demonstrated higher stability and better proliferation as compared to collagen that was physically adsorbed onto PDMS after oxygen plasma treatment. To assess the stability of the cellular adhesion, cells were forced in a shear flow until detachment. In devices with APTES-anchored collagen, cells showed better adhesion and proliferation at shear stresses between 11.6 and 93dyn/cm
2 as compared to devices with the adsorbed collagen coating where the first cellular detachment occurred already at a shear stress of 23dyn/cm2 . The APTES-attached collagen coating also contributed to an improved long-term cellular growth (observed for 48h) at different shear stress levels (10-300dyn/cm2 ). Attachment of collagen with the help of APTES thus is a very promising technique not only to modify the glass but also to modify the PDMS surfaces of microfluidic devices for mechanotransduction experiments., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
50. Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids.
- Author
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Dubois C, Herzog N, Rüttiger C, Geißler A, Grange E, Kunz U, Kleebe HJ, Biesalski M, Meckel T, Gutmann T, Gallei M, and Andrieu-Brunsen A
- Abstract
In paper-based devices, capillary fluid flow is based on length-scale selective functional control within a hierarchical porous system. The fluid flow can be tuned by altering the paper preparation process, which controls parameters such as the paper grammage. Interestingly, the fiber morphology and nanoporosity are often neglected. In this work, porous voids are incorporated into paper by the combination of dense or mesoporous ceramic silica coatings with hierarchically porous cotton linter paper. Varying the silica coating leads to significant changes in the fluid flow characteristics, up to the complete water exclusion without any further fiber surface hydrophobization, providing new approaches to control fluid flow. Additionally, functionalization with redox-responsive polymers leads to reversible, dynamic gating of fluid flow in these hybrid paper materials, demonstrating the potential of length scale specific, dynamic, and external transport control.
- Published
- 2017
- Full Text
- View/download PDF
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