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302. MEASUREMENT OF FLOW IN PERFUSED ORGANS, USING MICROSPHERE TECHNIQUES

Author

Rudolph, Abraham M. and Heymann, Michael A.

Abstract

Injection of radionuclide labelled microspheres into the circulation of animals can be used to measure the proportion of blood flow to any organ, or the regional distribution of blood flow within any organ. The use of this technique depends on the fact that these microspheres are distributed according to the blood flow and that they are completely trapped within the organ. It is important that they are adequately mixed within the flowing stream and also evenly distributed at branching sites. It has been shown that for the assessment of the regional distribution within an organ, microspheres of small diameter (10–15 μm) are preferable since they more accurately reflect true flow to all segments of the organ. The accurate measurement of the distribution of flow is also dependent on the absolute number of microspheres present in any organ or segment of organ under study.Studies of regional distribution of flow during cardio-pulmonary bypass in rhesus monkeys have shown that the proportion of cardiac output distributed to the kidneys falls, while that to the gut increases. The haematocrit of the perfusing blood may modify the distribution of flow to organs; thus, cerebral blood flow was maintained while using blood of low haematocrit whereas with normal haematocrit it fell during perfusion. The regional distribution of the blood flow within the kidney has been shown to change markedly with artificial perfusion in situwith a striking increase in flow to the medulla and inner cortex during perfusion as compared to normal.

Published
1972
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303. The Pattern and Mechanisms of Response to Oxygen by the Ductus Arteriosus and Umbilical Artery

Author

OBERHÄNSLI-WEISS, INGRID, HEYMANN, MICHAEL A., RUDOLPH, ABRAHAM M., and MELMON, KENNETH L.

Abstract

Response of the ductus arteriosus and umbilical artery to changes in oxygen tension, to acetylcholine, and to sympathetic and parasympathetic blocking agents was studied in vitroin isolated rings obtained from 22 fetal lambs of 98− to 147-day gestation.

Published
1972

304. Toxicity of lidocaine in the fetal and newborn lamb and its relationship to asphyxia

Author

MorishimaM.D, Hisayo O., Heymann, Michael A., Rudolph, Abraham M., and Barrett, Cynthia T.

Abstract

Toxic effects of lidocaine upon the fetal and newborn lamb were studied. Lidocaine hydrochloride was administered directly to 7 fetuses and 6 newborn lambs. Transient bradycardia followed by tachycardia occurred in all lambs immediately following intravenous infusion of lidocaine. This tachycardia was maintained until cardiovascular failure occurred. Tolerance of the fetus to lidocaine was higher than that of the newborn lamb, but it was reduced in both by asphyxia.

Published
1972
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305. Developmental Changes in Constriction of the Ductus Arteriosus: Responses to Oxygen and Vasoactive Agents in the Isolated Ductus Arteriosus of the Fetal Lamb

Author

Mcmurphy, Dorothy M, Heymann, Michael A, Rudolph, Abraham M, and Melmon, Kenneth L

Abstract

Extract: Development of the constrictor response of the ductus arteriosus to O2and selected vasoactive drugs (acetylcholine and bradykinin) was studied in 20 fetal lambs weighing 680–4800 g (90- to 150-day gestation). The isolated ductus arteriosus was perfused in vitro with Tyrode's solution at constant flow, temperature (38°), pH (7.3–7.4), and Pco2(30–40 mm Hg), and the mean pressure difference across the ductus was measured. Ductal resistance was calculated at different levels of PO2(10–700 mm Hg), raised stepwise to produce dose-response curves. Three young fetuses failed to respond initially to O2and in the other 17 the initial response occurred at progressively lower PO2levels with advancing gestation. The maximal degree of constriction developed showed a progressive increase with advancing gestational age.At any given PO2, both acetylcholine and bradykinin produced a further increase in resistance when added to the perfusion solution, but this further increase was independent of age. The level of PO2at which an initial response occurred was decreased after exposure to acetylcholine but not bradykinin.Speculation: The ductus arteriosus of the fetal lamb constricts when exposed to oxygen. The initial level of PO2at which this constriction occurs decreases, and the maximal degree of constriction increases, with advancing gestational age. The poor response to oxygen of the ductus arteriosus in the immature fetus may be the mechanism responsible for the high incidence of patent ductus arteriosus in premature infants. Constriction following-oxygen may be augmented by the exposure to acetylcholine or bradykinin.

Published
1972
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307. Alpha and beta adrenergic receptor activity in fetal sheep

Author

Barrett, Cynthia T., Heymann, Michael A., and Rudolph, Abraham M.

Abstract

Fetal circulatory responses to infusions of isoproterenol and methoxamine were measured in 16 fetal sheep with weights between 138 grams and 4.75 kilograms. During isoproterenol infusion in 9 animals, heart rate increased from a mean of 196 to 247 and mean umbilical blood flow increased from 211 to 269 ml. per kilogram per minute. Cardiac output, measured by radionuclide labeled microspheres, did not change significantly but was redistributed with preferential flow to the placenta and myocardium. During methoxamine infusion in 7 studies, mean arterial pressure increased from a mean value of 46 mm. Hg to 56 mm. Hg and mean unbilical blood flow decreased from 217 to 177 ml. per kilogram per minute. Cardiac output decreased in all animals (mean decrease, 22.5 per cent). Renal blood flow decreased out of proportion to the change in cardiac output; the proportion of cardiac output supplying the lungs increased, and in 6 animals actual flow to the lungs also increased.

Published
1972
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308. Precision 3D‐Printed Cell Scaffolds Mimicking Native Tissue Composition and Mechanics

Author

Erben, Amelie, Hörning, Marcel, Hartmann, Bastian, Becke, Tanja, Eisler, Stephan A., Southan, Alexander, Cranz, Séverine, Hayden, Oliver, Kneidinger, Nikolaus, Königshoff, Melanie, Lindner, Michael, Tovar, Günter E. M., Burgstaller, Gerald, Clausen‐Schaumann, Hauke, Sudhop, Stefanie, and Heymann, Michael

Abstract

Cellular dynamics are modeled by the 3D architecture and mechanics of the extracellular matrix (ECM) and vice versa. These bidirectional cell‐ECM interactions are the basis for all vital tissues, many of which have been investigated in 2D environments over the last decades. Experimental approaches to mimic in vivo cell niches in 3D with the highest biological conformity and resolution can enable new insights into these cell‐ECM interactions including proliferation, differentiation, migration, and invasion assays. Here, two‐photon stereolithography is adopted to print up to mm‐sized high‐precision 3D cell scaffolds at micrometer resolution with defined mechanical properties from protein‐based resins, such as bovine serum albumin or gelatin methacryloyl. By modifying the manufacturing process including two‐pass printing or post‐print crosslinking, high precision scaffolds with varying Young's moduli ranging from 7‐300 kPa are printed and quantified through atomic force microscopy. The impact of varying scaffold topographies on the dynamics of colonizing cells is observed using mouse myoblast cells and a 3D‐lung microtissue replica colonized with primary human lung fibroblast. This approach will allow for a systematic investigation of single‐cell and tissue dynamics in response to defined mechanical and bio‐molecular cues and is ultimately scalable to full organs. 3D printed cell niches with the highest biological conformity and resolution offer tantalizing avenues for tissue engineering, cell and developmental biology. mm‐sized 3D scaffolds with micrometer precision, defined mechanical properties and low autofluorescence are fabricated from extracellular matrix derived gelatin methacryloyl. These scaffolds are compatible with various cell‐lines, including myoblasts colonized on alignment promoting substrates and lung fibroblasts on in vivo derived 3D topographies.

Published
2020
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310. Strictly Observable Linear Systems

Author

FLORIDA UNIV GAINESVILLE CENTER FOR MATHEMATICAL SYSTEM THEORY, Hammer,Jacob, Heymann,Michael, FLORIDA UNIV GAINESVILLE CENTER FOR MATHEMATICAL SYSTEM THEORY, Hammer,Jacob, and Heymann,Michael

Published
1981

311. Rest Point Theorems for Autonomous Control Systems.

Author

FLORIDA UNIV GAINESVILLE CENTER FOR MATHEMATICAL SYSTEM THEORY, Hautus,M. L. J., Heymann,Michael, Stern,Ronald J., FLORIDA UNIV GAINESVILLE CENTER FOR MATHEMATICAL SYSTEM THEORY, Hautus,M. L. J., Heymann,Michael, and Stern,Ronald J.

Abstract

The classical Poincare-Bendixson theory in the plane is generalized to multivalued vector fields. For control systems x = f(x, u) where the state x is in R(n) subset and the control u is valued in a compact subset of R(m) we study the existence (and nonexistence) of rest states. Some special emphasis is focused on the case n = 2.

Published
1975

313. Megahertz serial crystallography

Author

Wiedorn, Max Oliver, Oberth��r, Dominik, Bean, Richard, Schubert, Robin, Werner, Nadine, Abbey, Brian, Aepfelbacher, Martin, Adriano, Luigi, Allahgholi, Aschkan, Al-Qudami, Nasser, Andreasson, Jakob, Horke, Daniel A., Hunter, Mark S., Imlau, Siegfried, Kaukher, Alexander, Kim, Yoonhee, Klyuev, Alexander, Kno��ka, Juraj, Kobe, Bostjan, Kuhn, Manuela, Kupitz, Christopher, M��hlig, Kerstin, K��pper, Jochen, Lahey-Rudolph, Janine Mia, Laurus, Torsten, Le Cong, Karoline, Letrun, Romain, Xavier, Paulrajpillai Lourdu, Maia, Luis, Maia, Filipe R. N. C., Mariani, Valerio, Messerschmidt, Marc, Munke, Anna, Metz, Markus, Mezza, Davide, Michelat, Thomas, Mills, Grant, Monteiro, Diana C.F., Morgan, Andrew J., M��nnich, Astrid, Nette, Julia, Nugent, Keith A., Nuguid, Theresa, Orville, Allen M., Pandey, Suraj, Pena, Gisel, Villanueva-Perez, Pablo, Shelby, Megan L., P��hlsen, Jennifer, Previtali, Gianpietro, Redecke, Lars, Riekehr, Winnie Maria, Rohde, Holger, Round, Adam R., Safenreiter, Tatiana, Sarrou, Iosifina, Sato, Tokushi, Schmidt, Marius, Shoemann, Robert L., Schmitt, Bernd, Sch��nherr, Robert, Schulz, Joachim, Sellberg, Jonas Alexander, Seibert, M. Marvin, Seuring, Carolin, Sikorski, Marcin, Silenzi, Alessandro, Stan, Claudiu A., Shi, Xintian, Stern, Stephan, Sztuk-Dambietz, Jolanta, Szuba, Janusz, Tolstikova, Aleksandra, Aplin, Steven, Trebbin, Martin, Trunk, Ulrich, Vagovic, Patrik, Ve, Thomas, Weinhausen, Britta, White, Thomas A., Wrona, Krzysztof, Xu, Chen, Yefanov, Oleksandr, Zatsepin, Nadia, Awel, Salah, Zhang, Jiaguo, Perbandt, Markus, Mancuso, Adrian P., Betzel, Christian, Chapman, Henry N., Banty, Anton, Ayyer, Kartik, Bajt, Sa��a, Bar��k, Imrich, Bari, Sadia, Bielecki, Johan, Botha, Sabine, Boukhelef, Djelloul, Brehm, Wolfgang, Brockhauser, Sandor, Cheviakov, Igor, Coleman, Matthew A., Cruz-Mazo, Francisco, Danilevski, Cyril, Darmanin, Connie, Doak, R. Bruce, Domaracky, Martin, D��rner, Katerina Henrike, Du, Yang, Fangohr, Hans, Fleckenstein, Holger, Frank, Matthias, Fromme, Petra, Ga����n-Calvo, Alfonso M., Gevorkov, Yaroslav, Giewekemeyer, Klaus, Ginn, Helen Mary, Graafsma, Heinz, Graceffa, Rita, Greiffenberg, Dominic, Gumprecht, Lars, G��ttlicher, Peter, Hajdu, J��nos, Hauf, Steffen, Heymann, Michael, and Holmes, Susannah

Subjects
600: Technik, 3. Good health
Abstract

The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a ��-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source.

314. Ultracompact 3D microfluidics for time-resolved structural biology

Author

Knoska, Juraj, Adriano, Luigi, Awel, Salah, Beyerlein, Kenneth R., Yefanov, Oleksandr, Oberthuer, Dominik, Pena Murillo, Gisel Esperanza, Roth, Nils, Sarrou, Iosifina, Villanueva-Perez, Pablo, Wiedorn, Max O., Wilde, Fabian, Bajt, Saša, Chapman, Henry N., and Heymann, Michael

Subjects
3. Good health
Abstract

Nature Communications 11(1), 657 (2020). doi:10.1038/s41467-020-14434-6, To advance microfluidic integration, we present the use of two-photon additive manufacturing to fold 2D channel layouts into compact free-form 3D fluidic circuits with nanometer precision. We demonstrate this technique by tailoring microfluidic nozzles and mixers for time-resolved structural biology at X-ray free-electron lasers (XFELs). We achieve submicron jets with speeds exceeding 160 m s−1, which allows for the use of megahertz XFEL repetition rates. By integrating an additional orifice, we implement a low consumption flow-focusing nozzle, which is validated by solving a hemoglobin structure. Also, aberration-free in operando X-ray microtomography is introduced to study efficient equivolumetric millisecond mixing in channels with 3D features integrated into the nozzle. Such devices can be printed in minutes by locally adjusting print resolution during fabrication. This technology has the potential to permit ultracompact devices and performance improvements through 3D flow optimization in all fields of microfluidic engineering., Published by Nature Publishing Group UK, [London]

316. Analysis of XFEL serial diffraction data from individual crystalline fibrils

Author

Wojtas, David H., Ayyer, Kartik, Liang, Mengning, Mossou, Estelle, Romoli, Filippo, Seuring, Carolin, Beyerlein, Kenneth, Bean, Richard J., Morgan, Andrew, Oberthuer, Dominik, Fleckenstein, Holger, Heymann, Michael, Gati, Cornelius, Yefanov, Oleksandr, Barthelmess, Miriam, Ornithopoulou, Eirini, Galli, Lorenzo, Xavier, P. Lourdu, Ling, Wai Li, Frank, Matthias, Yoon, Chun Hong, White, Thomas A., Bajt, Saša, Mitraki, Anna, Boutet, Sebastien, Aquila, Andrew, Barty, Anton, Forsyth, V. Trevor, Chapman, Henry N., and Millane, Rick P.

Subjects
3. Good health
Abstract

IUCrJ 4(6), 795 - 811 (2017). doi:10.1107/S2052252517014324, Serial diffraction data collected at the Linac Coherent Light Source from crystalline amyloid fibrils delivered in a liquid jet show that the fibrils are well oriented in the jet. At low fibril concentrations, diffraction patterns are recorded from single fibrils; these patterns are weak and contain only a few reflections. Methods are developed for determining the orientation of patterns in reciprocal space and merging them in three dimensions. This allows the individual structure amplitudes to be calculated, thus overcoming the limitations of orientation and cylindrical averaging in conventional fibre diffraction analysis. The advantages of this technique should allow structural studies of fibrous systems in biology that are inaccessible using existing techniques., Published by IUCr, Chester

317. Megahertz serial crystallography

Author

Wiedorn, Max O., Oberthür, Dominik, Bean, Richard, Schubert, Robin, Werner, Nadine, Abbey, Brian, Aepfelbacher, Martin, Adriano, Luigi, Allah Gholi, Aschkan, Al-Qudami, Nasser, Andreasson, Jakob, Aplin, Steve, Awel, Salah, Ayyer, Kartik, Bajt, Saša, Barák, Imrich, Bari, Sadia, Bielecki, Johan, Botha, Sabine, Boukhelef, Djelloul, Brehm, Wolfgang, Brockhauser, Sandor, Cheviakov, Igor, Coleman, Matthew A., Cruz-Mazo, Francisco, Danilevski, Cyril, Darmanin, Connie, Doak, R. Bruce, Domaracky, Martin, Dörner, Katerina, Du, Yang, Fangohr, Hans, Fleckenstein, Holger, Frank, Matthias, Fromme, Petra, Gañán-Calvo, Alfonso M., Gevorkov, Yaroslav, Giewekemeyer, Klaus, Ginn, Helen, Graafsma, Heinz, Graceffa, Rita, Greiffenberg, Dominic, Gumprecht, Lars, Göttlicher, Peter, Hajdu, Janos, Hauf, Steffen, Heymann, Michael, Holmes, Susannah, Horke, Daniel A., Hunter, Mark S., Imlau, Siegfried, Kaukher, Alexander, Kim, Yoonhee, Klyuev, Alexander, Knoska, Juraj, Kobe, Bostjan, Kuhn, Manuela, Kupitz, Christopher, Küpper, Jochen, Lahey-Rudolph, Janine Mia, Laurus, Torsten, Le Cong, Karoline, Letrun, Romain, Xavier, P. Lourdu, Maia, Luis, Maia, Filipe R. N. C., Mariani, Valerio, Messerschmidt, Marc, Metz, Markus, Mezza, Davide, Michelat, Thomas, Mills, Grant, Monteiro, Diana, Morgan, Andrew, Mühlig, Kerstin, Munke, Anna, Münnich, Astrid, Nette, Julia, Nugent, Keith A., Nuguid, Theresa, Orville, Allen M., Pandey, Suraj, Pena, Gisel, Villanueva-Perez, Pablo, Poehlsen, Jennifer, Previtali, Gianpietro, Redecke, Lars, Riekehr, Winnie Maria, Rohde, Holger, Round, Adam, Safenreiter, Tatiana, Sarrou, Iosifina, Sato, Tokushi, Schmidt, Marius, Schmitt, Bernd, Schönherr, Robert, Schulz, Joachim, Sellberg, Jonas A., Seibert, M. Marvin, Seuring, Carolin, Shelby, Megan L., Shoeman, Robert L., Sikorski, Marcin, Silenzi, Alessandro, Stan, Claudiu A., Shi, Xintian, Stern, Stephan, Sztuk-Dambietz, Jola, Szuba, Janusz, Tolstikova, Aleksandra, Trebbin, Martin, Trunk, Ulrich, Vagovic, Patrik, Ve, Thomas, Weinhausen, Britta, White, Thomas A., Wrona, Krzysztof, Xu, Chen, Yefanov, Oleksandr, Zatsepin, Nadia, Zhang, Jiaguo, Perbandt, Markus, Mancuso, Adrian, Betzel, Christian, Chapman, Henry, and Barty, Anton

Subjects
3. Good health
Abstract

Nature Communications 9(1), 4025 (2018). doi:doi.org/10.1038/s41467-018-06156-7, The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a β-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source., Published by Nature Publishing Group, London

318. Rapid Sample Delivery for Megahertz Serial Crystallography at X-ray FELs

Author

Wiedorn, Max O., Awel, Salah, Morgan, Andrew J., Ayyer, Kartik, Gevorkov, Yaroslav, Fleckenstein, Holger, Roth, Nils, Adriano, Luigi, Bean, Richard, Beyerlein, Kenneth R., Chen, Joe, Coe, Jesse, Cruz-Mazo, Francisco, Ekeberg, Tomas, Graceffa, Rita, Heymann, Michael, Horke, Daniel A., Knoška, Juraj, Mariani, Valerio, Nazari, Reza, Oberthür, Dominik, Samanta, Amit K., Sierra, Raymond G., Stan, Claudiu A., Yefanov, Oleksandr, Rompotis, Dimitrios, Correa, Jonathan, Erk, Benjamin, Treusch, Rolf, Schulz, Joachim, Hogue, Brenda G., Gañán-Calvo, Alfonso M., Fromme, Petra, Küpper, Jochen, Rode, Andrei V., Bajt, Saša, Kirian, Richard A., and Chapman, Henry N.

Subjects
3. Good health
Abstract

IUCrJ 5(5), 574 - 584 (2018). doi:10.1107/S2052252518008369, Liquid microjets are a common means of delivering protein crystals to the focus of X-ray free-electron lasers (FELs) for serial femtosecond crystallography measurements. The high X-ray intensity in the focus initiates an explosion of the microjet and sample. With the advent of X-ray FELs with megahertz rates, the typical velocities of these jets must be increased significantly in order to replenish the damaged material in time for the subsequent measurement with the next X-ray pulse. This work reports the results of a megahertz serial diffraction experiment at the FLASH FEL facility using 4.3 nm radiation. The operation of gas-dynamic nozzles that produce liquid microjets with velocities greater than 80 m s$^{−1}$ was demonstrated. Furthermore, this article provides optical images of X-ray-induced explosions together with Bragg diffraction from protein microcrystals exposed to trains of X-ray pulses repeating at rates of up to 4.5 MHz. The results indicate the feasibility for megahertz serial crystallography measurements with hard X-rays and give guidance for the design of such experiments., Published by Chester

319. Megahertz serial crystallography

Author

Wiedorn, Max O., Oberthür, Dominik, Bean, Richard, Schubert, Robin, Werner, Nadine, Abbey, Brian, Aepfelbacher, Martin, Adriano, Luigi, Allahgholi, Aschkan, Al-Qudami, Nasser, Andreasson, Jakob, Aplin, Steve, Awel, Salah, Ayyer, Kartik, Bajt, Saša, Barak, Imrich, Bari, Sadia, Bielecki, Johan, Botha, Sabine, Boukhelef, Djelloul, Brehm, Wolfgang, Brockhauser, Sandor, Cheviakov, Igor, Coleman, Matthew A., Cruz-Mazo, Francisco, Danilevski, Cyril, Darmanin, Connie, Doak, R. Bruce, Domaracky, Martin, Dörner, Katerina, Du, Yang, Fangohr, Hans, Fleckenstein, Holger, Frank, Matthias, Fromme, Petra, Ganan-Calvo, Alfonso, Gevorkov, Yaroslav, Giewekemeyer, Klaus, Ginn, Helen, Graafsma, Heinz, Graceffa, Rita, Greiffenberg, Dominic, Gumprecht, Lars, Göttlicher, Peter, Hajdu, Janos, Hauf, Steffen, Heymann, Michael, Holmes, Susannah, Horke, Daniel A., Hunter, Mark S., Imlau, Siegfried, Kaukher, Alexander, Kim, Yoonhee, Klyuev, Alexander, Knoska, Juraj, Kobe, Bostjan, Kuhn, Manuela, Kupitz, Christopher, Küpper, Jochen, Lahey-Rudolph, Janine Mia, Laurus, Torsten, Le Cong, Karoline, Letrun, Romain, Xavier, P. Lourdu, Maia, Luis, Maia, Filipe R. N. C., Mariani, Valerio, Messerschmidt, Marc, Metz, Markus, Mezza, Davide, Michelat, Thomas, Mills, Grant, Monteiro, Diana, Morgan, Andrew, Mühlig, Kerstin, Munke, Anna, Münnich, Astrid, Nette, Julia, Nugent, Keith, Nuguid, Theresa, Orville, Allen, Pandey, Suraj, Pena, Gisel, Villanueva-Perez, Pablo, Poehlsen, Jennifer, Previtali, Gianpietro, Redecke, Lars, Riekehr, Winnie Maria, Rohde, Holger, Round, Adam, Safenreiter, Tatiana, Sarrou, Iosifina, Sato, Tokushi, Schmidt, Marius, Schmitt, Bernd, Schönherr, Robert, Schulz, Joachim, Sellberg, Jonas, Seibert, M. Marvin, Seuring, Carolin, Shelby, Megan, Shoeman, Robert, Sikorski, Marcin, Silenzi, Alessandro, Stan, Claudiu, Shi, Xintian, Stern, Stephan, Sztuk-Dambietz, Jola, Szuba, Janusz, Tolstikova, Aleksandra, Trebbin, Martin, Trunk, Ulrich, Vagovic, Patrik, Ve, Thomas, Weinhausen, Britta, White, Thomas A., Wrona, Krzysztof, Xu, Chen, Yefanov, Oleksandr, Zatsepin, Nadia, Zhang, Jiaguo, Perbandt, Markus, Mancuso, Adrian P., Betzel, Christian, Chapman, Henry, and Barty, Anton

Subjects
3. Good health
Abstract

Nature Communications 9(1), 4025 (2018). doi:10.1038/s41467-018-06156-7, The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a β-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reli- able structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source., Published by Nature Publishing Group, London

320. Mix-and-diffuse serial synchrotron crystallography

Author

Beyerlein, Kenneth R., Dierksmeyer, Dennis, Mariani, Valerio, Kuhn, Manuela, Sarrou, Iosifina, Ottaviano, Angelica, Awel, Salah, Knoska, Juraj, Fuglerud, Silje, Jönsson, Olof, Stern, Stephan, Wiedorn, Max O., Yefanov, Oleksandr, Adriano, Luigi, Bean, Richard, Burkhardt, Anja, Fischer, Pontus, Heymann, Michael, Horke, Daniel A., Jungnickel, Katharina E. J., Kovaleva, Elena, Lorbeer, Olga, Metz, Markus, Meyer, Jan, Morgan, Andrew, Pande, Kanupriya, Panneerselvam, Saravanan, Seuring, Carolin, Tolstikova, Aleksandra, Lieske, Julia, Aplin, Steve, Roessle, Manfred, White, Thomas A., Chapman, Henry N., Meents, Alke, and Oberthuer, Dominik

Subjects
3. Good health
Abstract

IUCrJ 4(6), 769 - 777 (2017). doi:10.1107/S2052252517013124, Unravelling the interaction of biological macromolecules with ligands and substrates at high spatial and temporal resolution remains a major challenge in structural biology. The development of serial crystallography methods at X-ray free-electron lasers and subsequently at synchrotron light sources allows new approaches to tackle this challenge. Here, a new polyimide tape drive designed for mix-and-diffuse serial crystallography experiments is reported. The structure of lysozyme bound by the competitive inhibitor chitotriose was determined using this device in combination with microfluidic mixers. The electron densities obtained from mixing times of 2 and 50 s show clear binding of chitotriose to the enzyme at a high level of detail. The success of this approach shows the potential for high-throughput drug screening and even structural enzymology on short timescales at bright synchrotron light sources., Published by Chester

321. Ultracompact 3D microfluidics for time-resolved structural biology

Author

Knoška, Juraj, Adriano, Luigi, Awel, Salah, Beyerlein, Kenneth R., Yefanov, Oleksandr, Oberthuer, Dominik, Peña Murillo, Gisel E., Roth, Nils, Sarrou, Iosifina, Villanueva-Perez, Pablo, Wiedorn, Max O., Wilde, Fabian, Bajt, Saša, Chapman, Henry N., and Heymann, Michael

Subjects
3. Good health
Abstract

Nature Communications 11(1), 657 (2020). doi:10.1038/s41467-020-14434-6, To advance microfluidic integration, we present the use of two-photon additive manufacturing to fold 2D channel layouts into compact free-form 3D fluidic circuits with nanometer precision. We demonstrate this technique by tailoring microfluidic nozzles and mixers for time-resolved structural biology at X-ray free-electron lasers (XFELs). We achieve submicron jets with speeds exceeding 160 m s−1, which allows for the use of megahertz XFEL repetition rates. By integrating an additional orifice, we implement a low consumption flow-focusing nozzle, which is validated by solving a hemoglobin structure. Also, aberration-free in operando X-ray microtomography is introduced to study efficient equivolumetric millisecond mixing in channels with 3D features integrated into the nozzle. Such devices can be printed in minutes by locally adjusting print resolution during fabrication. This technology has the potential to permit ultracompact devices and performance improvements through 3D flow optimization in all fields of microfluidic engineering., Published by Nature Publishing Group UK, [London]

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