8 results
The Effect of Aerobic Exercise on Concussion Recovery: A Pilot Clinical Trial
- Aliyah R. Snyder, Sarah M. Greif, James R. Clugston, David B. FitzGerald, Joshua F. Yarrow, Talin Babikian, Christopher C. Giza, Floyd J. Thompson, Russell M. Bauer
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- Journal:
- Journal of the International Neuropsychological Society / Volume 27 / Issue 8 / September 2021
- Published online by Cambridge University Press:
- 16 November 2021, pp. 790-804
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Objective:
The purpose of this study was to pilot safety and tolerability of a 1-week aerobic exercise program during the post-acute phase of concussion (14–25 days post-injury) by examining adherence, symptom response, and key functional outcomes (e.g., cognition, mood, sleep, postural stability, and neurocognitive performance) in young adults.
Method:A randomized, non-blinded pilot clinical trial was performed to compare the effects of aerobic versus non-aerobic exercise (placebo) in concussion patients. The study enrolled three groups: 1) patients with concussion/mild traumatic brain injury (mTBI) randomized to an aerobic exercise intervention performed daily for 1-week, 2) patients with concussion/mTBI randomized to a non-aerobic (stretching and calisthenics) exercise program performed daily for 1-week, and 3) non-injured, no intervention reference group.
Results:Mixed-model analysis of variance results indicated a significant decrease in symptom severity scores from pre- to post-intervention (mean difference = −7.44, 95% CI [−12.37, −2.20]) for both concussion groups. However, the pre- to post-change was not different between groups. Secondary outcomes all showed improvements by post-intervention, but no differences in trajectory between the groups. By three months post-injury, all outcomes in the concussion groups were within ranges of the non-injured reference group.
Conclusions:Results from this study indicate that the feasibility and tolerability of administering aerobic exercise via stationary cycling in the post-acute time frame following post-concussion (14–25 days) period are tentatively favorable. Aerobic exercise does not appear to negatively impact recovery trajectories of neurobehavioral outcomes; however, tolerability may be poorer for patients with high symptom burden.
Appropriate use of echocardiography for palpitations in paediatric cardiology clinics
- Saloni Sheth, Munes Fares, Sandra Kikano, Christopher Snyder, Andrew Dodgen, Carolyn M. Wilhelm
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- Journal:
- Cardiology in the Young / Volume 31 / Issue 1 / January 2021
- Published online by Cambridge University Press:
- 07 October 2020, pp. 60-62
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Objectives:
Identify diagnostic yield and frequency of echocardiograms for palpitation-related indications at outpatient paediatric cardiology clinics in relation to the 2014 ACC/AAP/AHA/ASE/HRS/SCAI/SCCT/SCMR/SOPE appropriate use criteria for Initial Transthoracic Echocardiography in Outpatient Paediatric Cardiology.
Study design:A single-centre, retrospective study of children presenting for evaluation of a chief complaint of palpitations to outpatient paediatric cardiology clinics from 2015 to 2017. Palpitations were defined as an unpleasant sensation of rapid, irregular, and/or forceful beating of the heart. Indications for echocardiogram in patients were retrospectively classified based on the appropriate use criteria as “appropriate,” “may be appropriate,” or “rarely appropriate.” The incidence of abnormal and incidental echocardiographic findings for each category was determined.
Results:A total of 286 patients presented with palpitations, with 128 (52% female) meeting inclusion criteria. Exclusion criteria included patients with additional cardiac complaints, prior echocardiogram, or history of congenital heart disease. Echocardiograms were performed on 36 (28%) patients. The appropriate use criteria were retrospectively applied, and indications for their performance were classified as “appropriate” (n = 4), “may be appropriate” (n = 17), or “rarely appropriate” (n = 15). Minor echocardiographic abnormalities were present in 22% (n = 8) of echocardiograms obtained for all appropriate use criteria classifications. No moderate or severe echocardiographic abnormalities were found. Incidental findings were noted in eight echocardiograms.
Conclusion:Echocardiography in the evaluation of “rarely appropriate” and “may be appropriate” palpitation-related indications is of low diagnostic yield.
Quantifying Antimicrobial Exposure: Hazards in Populations With End-Stage Renal Disease
- Graham M. Snyder, Christopher McCoy, Erika M. C. D’Agata
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 38 / Issue 3 / March 2017
- Published online by Cambridge University Press:
- 05 December 2016, pp. 360-363
- Print publication:
- March 2017
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Using a rigorously collected data set of antimicrobial use among patients receiving chronic hemodialysis, antimicrobial use was calculated using 3 different methodologies: daily defined dose, days of therapy, and start–stop days. Estimates of antimicrobial use varied by as much as 10-fold, depending on the type of antimicrobial.
Infect Control Hosp Epidemiol 2017;38:360–363
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- Book:
- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
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Porous ultrathin silicon membranes for purification of nanoscale materials
- Christopher C Striemer, Thomas R Gaborski, David Z Fang, Jessica L Snyder, James L McGrath, Philippe M Fauchet
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1209 / 2009
- Published online by Cambridge University Press:
- 31 January 2011, 1209-P02-08
- Print publication:
- 2009
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A new class of porous membrane has been fabricated that is unique in its combination of nanoscale thickness (<50 nm) with macroscopic, yet robust, millimeter-scale lateral dimensions and tunable pore size in the range of ˜5nm to ˜100nm. The membrane material is porous nanocrystalline Si (pnc-Si)1, and is being scaled-up to commercial volumes by a startup company, SiMPore, Inc. Standard commercial separation membranes with pores in this size regime are polymeric materials (poly ether sulphone, cellulose, etc.), microns in thickness, leading to pore morphologies that resemble long narrow tubes or tortuous-path 3-D matrices. As pnc-Si membrane thickness approaches the pore diameters, a simplified structure of holes in a thin sheet results, greatly enhancing both diffusive and forced flow transport through the membrane, as predicted by classical transport theories2. Pnc-Si has confirmed these theoretical predictions, demonstrating record-breaking transport rates, in addition to precise size-separation of nanoparticles, viruses, proteins, and nucleic acids. Applications for this highly precise silicon-based membrane range from highly efficient separations and purification of biomolecules, complexes, and nanoparticles, to substrates for microscopy to cell culture and co-culture. SiMPore is focused on navigating this application space with the goal of quickly introducing products that will allow the company to become self-sustaining and profitable though direct sales or partnerships with market leaders. Key product development drivers include potential competitive performance advantages and perceived value to a particular market, the IP landscape, development costs of the membrane and the device package/interface, and alignment with existing in-house capabilities.
Enhanced hydrothermal conversion of surfactant-modified diatom microshells into barium titanate replicas
- Eric M. Ernst, Ben C. Church, Christopher S. Gaddis, Robert L. Snyder, Kenneth H. Sandhage
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- Journal:
- Journal of Materials Research / Volume 22 / Issue 5 / May 2007
- Published online by Cambridge University Press:
- 03 March 2011, pp. 1121-1127
- Print publication:
- May 2007
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The three-dimensional nanostructured SiO2-based microshells of diatoms have been converted into nanocrystalline BaTiO3 via a series of shape-preserving reactions. The microshells, obtained as diatomaceous earth, were first exposed to a surfactant-induced dissolution/reprecipitation process [C.E. Fowler, et al., Chem. Phys. Lett.398, 414 (2004)] to enhance the microshell surface area, without altering the microshell shape. The SiO2 microshells were then converted into anatase TiO2 replicas via reaction with TiF4 gas and then humid oxygen. Hydrothermal reaction with a barium hydroxide-bearing solution then yielded three-dimensional nanocrystalline microshell replicas composed of BaTiO3. The enhanced surface area of the surfactant-treated microshells resulted in faster conversion into phase-pure BaTiO3 at 100 °C.
Perovskite Particles from Phytoplankton
- Michael R. Weatherspoon, Shawn M. Allan, Christopher S. Gaddis, Ye Cai, Michael S. Haluska, Robert L. Snyder, Kenneth H. Sandhage
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- Journal:
- MRS Online Proceedings Library Archive / Volume 873 / 2005
- Published online by Cambridge University Press:
- 01 February 2011, K1.8
- Print publication:
- 2005
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Controlled-shape BaTiO3-based microparticles were synthesized with the use of diatom microshells (frustules) as templates. The SiO2-based frustules of Aulacoseira diatoms were first converted into MgO-based replicas via a gas/solid displacement reaction at 900°C. A BaTiO3 coating was then applied to the MgO-bearing frustules by a sol-gel process. After firing at 700°C for 1.5 h, a conformal nanocrystalline coating of BaTiO3was generated on the surfaces of the MgO-bearing frustules. The underlying MgO scaffolds were then selectively dissolved away to yield freestanding 3-D BaTiO3-based replicas of the original Aulacoseira diatom frustules. This work demonstrates that microparticles with well-controlled 3-D morphologies and non-natural multicomponent ceramic compositions can be produced by merging the self-assembly ability of biomineralizing micro-organisms with synthetic chemical tailoring.
Loan Commitments and the Debt Overhang Problem
- Christopher M. Snyder
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- Journal:
- Journal of Financial and Quantitative Analysis / Volume 33 / Issue 1 / March 1998
- Published online by Cambridge University Press:
- 09 June 2010, pp. 87-116
- Print publication:
- March 1998
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The debt overhang problem is shown to arise in the context of an entrepreneurial project that requires a sequence of investments financed by an outside lender. The entrepreneur, not internalizing losses accruing to the lender which financed the initial investments, may inefficiently cancel the project and instead pursue an outside opportunity. It is shown that loan commitments (contracts that allow the entrepreneur to borrow a variable amount at a set interest rate in return for a fixed fee) are the optimal financial contracts in this setting, strictly dominating standard debt. The existence of the fixed fee allows loan commitments to set a relatively low interest rate, improving the entrepreneur's incentives to continue the project. The paper specifies the optimal contract fully, derives robust comparative statics properties (using an extension of Milgrom and Roberts (1994)), and extends the results to more realistic settings (e.g., allowing the market risk-free rate to be stochastic).