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16 results on '"Sohrab Pahlavan"'

1. Use of Lateral Access in the Treatment of the Revision Spine Patient

Author

Samuel S. Bederman, Vu H. Le, Sohrab Pahlavan, Douglas P. Kiester, Nitin N. Bhatia, and Vedat Deviren

Subjects
Technology, Medicine, Science
Abstract

With the rate of spinal surgery increasing, we have seen a concomitant increase in the number of revision cases. It is, therefore, important to have a systematic approach to the management of these complicated patients with unique problems. A thorough understanding of the different pathologies affecting revision spine patients is critical to an effective treatment recommendation. Lateral access is a useful management approach since it can avoid the complications of operating through previous approaches. Furthermore, it possesses certain advantages for treatment in specific circumstances outlined in this paper. Long-term studies are needed to demonstrate the safety and efficacy of the lateral approach compared to the anterior and posterior approaches in the treatment of revision spine patients.

Published
2012
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2. Texture coding in the rat whisker system: slip-stick versus differential resonance.

Author

Jason Wolfe, Dan N Hill, Sohrab Pahlavan, Patrick J Drew, David Kleinfeld, and Daniel E Feldman

Subjects
Biology (General), QH301-705.5
Abstract

Rats discriminate surface textures using their whiskers (vibrissae), but how whiskers extract texture information, and how this information is encoded by the brain, are not known. In the resonance model, whisker motion across different textures excites mechanical resonance in distinct subsets of whiskers, due to variation across whiskers in resonance frequency, which varies with whisker length. Texture information is therefore encoded by the spatial pattern of activated whiskers. In the competing kinetic signature model, different textures excite resonance equally across whiskers, and instead, texture is encoded by characteristic, nonuniform temporal patterns of whisker motion. We tested these models by measuring whisker motion in awake, behaving rats whisking in air and onto sandpaper surfaces. Resonant motion was prominent during whisking in air, with fundamental frequencies ranging from approximately 35 Hz for the long Delta whisker to approximately 110 Hz for the shorter D3 whisker. Resonant vibrations also occurred while whisking against textures, but the amplitude of resonance within single whiskers was independent of texture, contradicting the resonance model. Rather, whiskers resonated transiently during discrete, high-velocity, and high-acceleration slip-stick events, which occurred prominently during whisking on surfaces. The rate and magnitude of slip-stick events varied systematically with texture. These results suggest that texture is encoded not by differential resonant motion across whiskers, but by the magnitude and temporal pattern of slip-stick motion. These findings predict a temporal code for texture in neural spike trains.

Published
2008
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3. The Contrast between the Pitting Corrosion of 316 SS in NaCl and NaBr Solutions: Part I. Evolution of Metastable Pitting and Stable Pitting

Author

Sohrab Pahlavan, Mohammad Hadi Moayed, and Mostafa Mirjalili

Subjects
Materials science, Renewable Energy, Sustainability and the Environment, Metastability, Inorganic chemistry, Materials Chemistry, Electrochemistry, Pitting corrosion, Halide, Contrast (music), Condensed Matter Physics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Published
2019
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4. The Contrast between the Pitting Corrosion of 316 SS in NaCl and NaBr Solutions: Part II. Morphology, Chemistry, and Stabilization of the Pits

Author

Mohammad Hadi Moayed, Sohrab Pahlavan, and Mostafa Mirjalili

Subjects
Morphology (linguistics), Chemical engineering, Renewable Energy, Sustainability and the Environment, Chemistry, Materials Chemistry, Electrochemistry, Pitting corrosion, Contrast (music), Condensed Matter Physics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Published
2019
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5. Pitting Corrosion of 17-4PH Stainless Steel: Impingement of a Fluid Jet vs. Erosion–Corrosion in the Presence of the Solid Particles

Author

Mohammad Hadi Moayed, Iman Taji, Mehrdad Zia Hoseinpoor, and Sohrab Pahlavan

Subjects
Jet (fluid), Materials science, Solid particle, 020209 energy, Mechanical Engineering, Materials Science (miscellaneous), Erosion corrosion, Metallurgy, Metals and Alloys, chemistry.chemical_element, Pit formation, 02 engineering and technology, Oxygen, Corrosion, 020303 mechanical engineering & transports, 0203 mechanical engineering, chemistry, Mechanics of Materials, 0202 electrical engineering, electronic engineering, information engineering, Materials Chemistry, Slurry, Pitting corrosion
Abstract

The pitting corrosion behaviour of 17-4PH (H900) stainless steel during static corrosion (SC), flow-induced corrosion (FIC) and erosion–corrosion (EC) conditions was studied. In comparison with SC, reduction in both corrosion potential (Ecorr) and pitting potential (Epit) was observed in the EC measurement with sand particles. This behaviour was attributed to the presence of depassivated areas with lower potential on the surface that moves Ecorr towards lower values and provided favourable locations for pit formation. Acceleration in the access of oxygen to the surface increased meaningfully the Ecorr in FIC condition and pitting corrosion occurred during open-circuit potential (OCP) measurement in the absence of external polarisation. However, long-term OCP measurements in SC and EC circumstances did not show stable pitting. Consequently, it was proposed that in some conditions, the FIC without eroding particles could be more detrimental compared to slurry EC.

Published
2020
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6. Investigation of the Microstructure Dependence of Critical Pitting Temperature and Pitting Potential in a 2205 Duplex Stainless Steel

Author

Sohrab Pahlavan, Ali Kosari, Mostafa Mirjalili, and Mohammad Hadi Moayed

Subjects
Materials science, Renewable Energy, Sustainability and the Environment, Duplex (building), Materials Chemistry, Electrochemistry, Composite material, Condensed Matter Physics, Microstructure, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Published
2021
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7. The Role of Lug Preheating, Melt Pool Temperature, and Lug Entrance Delay on the Cast-on-Strap Joining Process

Author

Saman Nikpour, Iman Taji, Sohrab Pahlavan, Mohammadyousef Azimi, Mostafa Mirjalili, and Ali Alagheband

Subjects
Work (thermodynamics), Structural material, Materials science, Metallurgy, Metals and Alloys, Evaporation, Thermodynamics, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, medicine.disease_cause, 01 natural sciences, Raising (metalworking), 0104 chemical sciences, Mechanics of Materials, Casting (metalworking), Mold, medicine, Wetting, Composite material, 0210 nano-technology, Joint (geology)
Abstract

This work deals with effective parameters in the cast-on-strap (COS) process during which grid lugs of a lead-acid battery are joined together by a strap. The effects of lug preheating, melt pool temperature, and lug entrance delay on the quality of joints and casting defects were investigated. Lug preheating was found to propitiously reduce joint internal voids because of flux elimination. Its adverse effect on lowering lug wettability, however, made it unfavorable under the experimental conditions. The melt pool temperature also showed a two-sided effect depending on the process conditions. Raising the temperature increases the strap melt fluidity, which improves the joint contact area; however, it has a negative effect on lug wettability by flux evaporation. Besides, higher temperatures cause more lug back-melting and, hence, lower relative contact lengths. Therefore, an intermediate temperature of 683 K (410 °C) was found to make the most proper condition. Moreover, the case at which the lugs enter the mold coincident with its filling by the melt rendered the best joint quality. In this condition, the melt flows through the interlug spaces, which helps the voids to escape, resulting in the better joint interface. As the conclusion, the lug entrance time has the most effective role on joint quality, considering that lug preheating does not show any improving effect.

Published
2017
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8. Proposed stability product criterion for open hemispherical metastable pits formed in the crevices of different aspect ratios (l/d) on 316L stainless steel in 3.5% NaCl solution

Author

Sohrab Pahlavan, E. Shojaei, Mohammad Hadi Moayed, and Mostafa Mirjalili

Subjects
Materials science, 020209 energy, General Chemical Engineering, Induction time, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Aspect ratio (image), Corrosion, Metastability, 0202 electrical engineering, electronic engineering, information engineering, General Materials Science, Composite material, 0210 nano-technology, Crevice corrosion
Abstract

This work investigates the mechanism of crevice corrosion for a 316 L stainless steel in 3.5 % NaCl solution and assesses its characteristics. Potentiodynamic, potentiostatic, and galvanostatic techniques along with SEM were used to characterize the crevice corrosion at various gap sizes of 5, 10, 30, 60, 120 and 240 μm. Results revealed that the crevice corrosion initiates by pitting events stabilization. Using a novel approach and considering the crevice aspect ratio (l/d), it is discussed how the crevice geometry can affect pit stability product criterion. By increasing the crevice gap, the pit stability product decreased and the induction time increased.

Published
2021
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9. Pitting corrosion of martensitic stainless steel in halide bearing solutions

Author

S. Mollazadeh Beidokhti, Mohammad Hadi Moayed, M. Hamrah, K. Saffar, Sohrab Pahlavan, S. Moazen, and Iman Taji

Subjects
Materials science, 020209 energy, General Chemical Engineering, fungi, Metallurgy, technology, industry, and agriculture, Halide, 02 engineering and technology, General Chemistry, Martensitic stainless steel, engineering.material, Corrosion, 0202 electrical engineering, electronic engineering, information engineering, Pitting corrosion, engineering, General Materials Science, Polarization (electrochemistry)
Abstract

In this research, pitting corrosion of martensitic stainless steel in presence of halide anions was investigated by using polarization techniques. Results confirm that the aggressivity of halides increases in the following order: I−

Published
2016
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10. Fungal spine

Author

Sohrab Pahlavan and Nitin N. Bhatia

Subjects
0301 basic medicine, 030222 orthopedics, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, Orthopedics and Sports Medicine, Surgery
Published
2016
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11. An Approach to Lumbar Revision Spine Surgery in Adults

Author

Sohrab Pahlavan, S. Samuel Bederman, and Vu Le

Subjects
Adult, Reoperation, medicine.medical_specialty, Population ageing, Decompression, medicine.medical_treatment, MEDLINE, Lumbar vertebrae, 03 medical and health sciences, 0302 clinical medicine, Spine surgery, Lumbar, Postoperative Complications, Medicine, Humans, Orthopedics and Sports Medicine, Medical diagnosis, 030222 orthopedics, Lumbar Vertebrae, business.industry, General surgery, Middle Aged, Decompression, Surgical, medicine.anatomical_structure, Spinal Fusion, Spinal fusion, Surgery, Spinal Diseases, business, 030217 neurology & neurosurgery
Abstract

Along with the increase in lifestyle expectations in the aging population, a dramatic rise in surgical rates has been observed over the past 2 decades. Consequently, the rate of revision spine surgery is expected to increase. A systematic approach to treatment is required for the adult patient presenting with late or chronic complications after spinal surgery. Patient assessment includes elucidating current symptoms and knowledge of the previous surgery, performing a detailed assessment, and obtaining appropriate studies. Subsequently, differential diagnoses are formulated based on whether the pathology arises from the same levels or adjacent levels of the spine and whether it relates to the previous decompression or fusion. Finally, familiarity with different surgical approaches is imperative in treating the common pathologies encountered in this patient population.

Published
2016

12. Variation in Costs of Spinal Implants in United States Academic Medical Centers

Author

Sohrab Pahlavan, Sigurd Berven, and Stacey Samuel Bederman

Subjects
Gerontology, Joint replacement, Transparency (market), medicine.medical_treatment, 03 medical and health sciences, Indirect costs, 0302 clinical medicine, Health care, medicine, Humans, Orthopedics and Sports Medicine, Operations management, 030212 general & internal medicine, health care economics and organizations, Retrospective Studies, Academic Medical Centers, business.industry, Unit price, Benchmarking, Health Care Costs, Purchasing, Internal Fixators, United States, Spinal Fusion, Neurology (clinical), Implant, business, 030217 neurology & neurosurgery
Abstract

Study design Retrospective study of benchmarking database. Objective To evaluate the variability in direct costs of spinal implants across various academic medical centers, determining variability between and within specific manufacturers, and to measure the relationship between purchasing volume and price. Summary of background data Spinal implants are a significant component of the cost of surgery. There is an absence of transparency of how much various medical centers in the United States pay for implants because of the use of nondisclosure agreements as part of price negotiations. Transparency of information on costs and awareness of costs by physicians will be useful in managing costs in a value-based health care economy. Methods Purchasing records of 45 academic medical centers over a 12-month period were examined. Purchasing volume and unit pricing for pedicle screws (PS), anterior cervical plates (ACP), and transforaminal lumbar interbody fusion (TLIF) cages were collected for 6 manufacturers. Overall variation in implant costs across centers and for each manufacturer was determined as was the relationship between purchasing volume and unit price. Results We found variation in implant costs between medical centers, and between manufacturers for PS, ACP and TLIF similar to joint replacement implants. Regression analysis showed that for each 10-fold increase in purchasing volume, the unit price decreased by $126 for PS, $242 for ACP, and $789 for TLIF. Conclusion There was variation in implant costs between medical centers and manufacturers of implants, with a small negative relationship between purchasing volume and cost. Transparency in cost negotiation, surgeon awareness of costs and alignment between surgeon and hospital goals may help decrease the cost of spinal implants, and the cost of care for patients undergoing instrumented fusions.

Published
2016

13. Use of Lateral Access in the Treatment of the Revision Spine Patient

Author

S. Samuel Bederman, Douglas Kiester, Vu Le, Sohrab Pahlavan, Nitin N. Bhatia, and Vedat Deviren

Subjects
trends, Reoperation, fusion, medicine.medical_specialty, deformity, proximal junctional kyphosis, lcsh:Medicine, Review Article, lcsh:Technology, General Biochemistry, Genetics and Molecular Biology, surgery, adjacent, Postoperative Complications, Medicine and Health Sciences, medicine, Deformity, Humans, Effective treatment, lcsh:Science, Intensive care medicine, General Environmental Science, instrumentation, lcsh:T, business.industry, lcsh:R, reoperation rates, stenosis, degenerative lumbar spine, General Medicine, Spinal surgery, Surgery, Treatment Outcome, lcsh:Q, Spinal Diseases, Approaches of management, medicine.symptom, business, Lateral approach
Abstract

With the rate of spinal surgery increasing, we have seen a concomitant increase in the number of revision cases. It is, therefore, important to have a systematic approach to the management of these complicated patients with unique problems. A thorough understanding of the different pathologies affecting revision spine patients is critical to an effective treatment recommendation. Lateral access is a useful management approach since it can avoid the complications of operating through previous approaches. Furthermore, it possesses certain advantages for treatment in specific circumstances outlined in this paper. Long-term studies are needed to demonstrate the safety and efficacy of the lateral approach compared to the anterior and posterior approaches in the treatment of revision spine patients.

Published
2012
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14. Reliability, Validity, and Responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index for Elderly Patients with a Femoral Neck Fracture

Author

Paul T.P.W. Burgers, Rudolf W Poolman, Theodorus MJ Van Bakel, Wim E Tuinebreijer, Stephanie M Zielinski, Mohit Bhandari, Peter Patka, Esther MM Van Lieshout, P J Devereaux, Gordon H Guyatt, Thomas A Einhorn, Lehana Thabane, Emil H Schemitsch, Kenneth J Koval, Frede Frihagen, Kevin Tetsworth, Ernesto Guerra-Farfan, Stephen D Walter, Sheila Sprague, Marilyn Swinton, Taryn Scott, Paula McKay, Kim Madden, Diane Heels-Ansdell, Lisa Buckingham, Aravin Duraikannan, Heather Silva, Martin J Heetveld, Robert D Zura, Victoria Avram, Ajay Manjoo, Dale Williams, John Antoniou, Tim Ramsay, Earl R Bogoch, Andrew Trenholm, Stephen Lyman, Madhu Mazumdar, Kevin J Bozic, Mark Luborsky, Stuart Goodman, Susan Muray, Rob Korley, Richard Buckley, Paul Duffy, Shannon Puloski, Kimberly Carcary, Melissa Lorenzo, Michael D McKee, Jeremy A Hall, Aaron Nauth, Daniel Whelan, Timothy R Daniels, James P Waddell, Henry Ahn, Milena R Vicente, Jennifer T Hidy, Melanie T MacNevin, Hans Kreder, Terry Axelrod, Richard Jenkinson, Markku Nousiainen, David Stephen, Veronica Wadey, Monica Kunz, Katrine Milner, Ria Cagaanan, Melanie MacNevin, Peter J O’Brien, Piotr A Blachut, Henry M Broekhuyse, Pierre Guy, Kelly A Lefaivre, Gerard P Slobogean, Raman Johal, Irene Leung, Chad Coles, Ross Leighton, C. Glen Richardson, Michael Biddulph, Michael Gross, Michael Dunbar, J. David Amirault, David Alexander, Catherine Coady, Mark Glazebrook, David Johnston, William Oxner, Gerald Reardon, Ivan Wong, Kelly Trask, Shelley MacDonald, Andrew Furey, Craig Stone, Minnie Parsons, Trevor Stone, Mauri Zomar, Robert McCormack, Kelly Apostle, Dory Boyer, Farhad Moola, Bertrand Perey, Darius Viskontas, Karyn Moon, Raely Moon, Yves Laflamme, Benoit Benoit, Pierre Ranger, Michel Malo, Julio Fernandes, Karine Tardif, Julie Fournier, Pascal André Vendittoli, Vincent Massé, Alain G Roy, Martin Lavigne, Daniel Lusignan, Craig Davis, Philip Stull, Stewart Weinerman, Peter Weingarten, Steven Lindenbaum, Michael Hewitt, Rebecca Danielwicz, Janell Baker, Michael Mont, Donald E Delanois, Bhaveen Kapadia, Kimona Issa, Marylou Mullen, Andrew Sems, Barb Foreman, Javad Parvizi, Tiffany Morrison, Courtland Lewis, Stephanie Caminiti, Paul Tornetta, William R Creevy, Michelle J Lespasio, Hope Carlisle, Andrew Marcantonio, Michael Kain, Lawrence Specht, John Tilzey, John Garfi, Samir Mehta, John L Esterhai, Jaimo Ahn, Derek Donegan, Annamarie Horan, Kelly McGinnis, James Roberson, Thomas Bradbury, Greg Erens, Kyle Webb, Brian Mullis, Karl Shively, Andrew Parr, Janos Ertl, Ripley Worman, Mark Webster, Judd Cummings, Valda Frizzell, Molly Moore, Clifford B Jones, James R Ringler, Debra L Sietsema, Jane E Walker, Enes Kanlic, Amr Abdelgawad, Juan Shunia, Charles DePaolo, Susan Sutherland, Rachel Alosky, Robert Zura, Maria Manson, Gregg Strathy, Kathleen Peter, Paul Johnson, Meaghan Morton, James Shaer, Tyson Schrickel, Barbara Hileman, Marina Hanes, Elisha Chance, E. Matthew Heinrich, David Dodgin, Michele LaBadie, David Zamorano, Martin Tynan, Ran Schwarzkopf, John A Scolaro, Ranjan Gupta, Samuel Bederman, Nitin Bhatia, Bang Hoang, Douglas Kiester, Neil Jones, Gregory Rafijah, Damon Alavekios, Jason Lee, Akshay Mehta, Steven Schroder, Tom Chao, Vincent Colin, Phuc (Phil) Dang, Stephen Keun Heng, Gregory Lopez, Samuel Galle, Sohrab Pahlavan, Duy L Phan, Minal Tapadia, Christopher Bui, Nickul Jain, Tyler Moore, Nathan Moroski, Deeba Pourmand, Erik N Kubiak, Jeremy Gililland, David Rothberg, Christopher Peters, Christopher Pelt, Ami R Stuart, Kirby Corbey, Franklin D Shuler, James Day, Tigran Garabekyan, Felix Cheung, Ali Oliashirazi, Jonathon Salava, Linda Morgan, Timothy Wilson-Byrne, Mary Beth Cordle, Leon H.G.J. Elmans, Joost A.A.M. van den Hout, Adrianus JP Joosten, Ad FA van Beurden, Stefan BT Bolder, Denise Eygendaal, Adrianus F.C.M. Moonen, Rutger CI van Geenen, Eric A Hoebink, Robert Wagenmakers, Wouter van Helden, Hans-Peter W van Jonbergen, Herbert Roerdink, Joost M Reuver, Alexander FW Barnaart, Elvira R Flikweert, Rover Krips, J. Bernard Mullers, Hans Schüller, Mark LM Falke, Frans J Kurek, Adrianus CH Slingerland, Jan P van Dijk, Wouter H van Helden, Hugo W Bolhuis, Pieter HJ Bullens, Mike Hogervorst, Karin E de Kroon, Rob H Jansen, Ferry Steenstra, Eric EJ Raven, W. Peter J Fontijne, Saskia C Wiersma, Bastiaan Boetes, Edgar JT ten Holder, Huub JL van der Heide, Jochem Nagels, Enrike H.M.J. van der Linden-van der Zwaag, Stefan B Keizer, Jan-Willem A Swen, Peter HC den Hollander, Bregje JW Thomassen, Willem Jan Kleyn Molekamp, Frank R.A.J. de Meulemeester, Arthur EB Kleipool, Robert Haverlag, Maarten P Simons, Eduard L.A.R. Mutsaerts, Rob Kooijman, Roelf R Postema, René J.T.M. Bleker, Harald IH Lampe, Lein Schuman, John Cheung, Frank van Bommel, W. Paul Winia, Daniel Haverkamp, Harm van der Vis, Peter A Nolte, Michel PJ van den Bekerom, Tjitte de Jong, Arthur van Noort, Diederik A Vergroesen, Bernard G Schutte, Harm M van der Vis, Lijkele Beimers, Jasper de Vries, Arthur W Zurcher, G.H. Rob Albers, Maarten Rademakers, Stefan Breugem, Ibo van der Haven, Pieter Jan Damen, Gythe H Bulstra, Martin M Campo, Mathijs P Somford, Daniël Haverkamp, Susan Liew, Harvinder Bedi, Ashley Carr, Andrew Chia, Steve Csongvay, Craig Donohue, Stephen Doig, Elton Edwards, Max Esser, Richard Freeman, Andrew Gong, Doug Li, Russell Miller, Lu Ton, Otis Wang, Ian Young, Adam Dowrick, Zoe Murdoch, Claire Sage, Richard Page, David Bainbridge, Richard Angliss, Ben Miller, Andrew Thomson, Graeme Brown, Simon Williams, Kevin Eng, David Bowyer, John Skelley, Chatar Goyal, Sally Beattie, Enrique Guerado, Encarnacion Cruz, Juan Ramon Cano, Miguel Angel Froufe, Lluis Marull Serra, Samer Al-dirra, Cristina Martinez, Francisco José Tarazona Santabalbina, Jordi Teixidor Serra, Jordi Tomas Hernandez, Marc Aguilar Garcia, Vicente Molero Garcia, Sergi Barrera, Miriam Garrido, Lars Nordsletten, John Clarke-Jenssen, Geir Hjorthaug, Anne Christine Brekke, Elise Berg Vesterhus, Ingunn Skaugrud, Pradeep Tripathi, Sandesh Katiyar, Preksha Shukla, Marc Swiontkowski, Gordon Guyatt, Kyle Jeray, Stephen Walter, Helena Viveiros, Victoria Truong, Kaitlin Koo, Qi Zhou, Deborah Maddock, Nicole Simunovic, Julie Agel, Amar Rangan, Birgit C Hanusch, Lucksy Kottam, Rachel Clarkson, Gregory J Della Rocca, Gerard Slobogean, Jeffrey Katz, Brenda Gillespie, Gail A Greendale, Curtis Hartman, Craig Rubin, James Waddell, H. Michael Lemke, Amber Oatt, Richard E Buckley, Robert Korley, Kelly Johnston, James Powell, David Sanders, Abdel Lawendy, Christina Tieszer, John Murnaghan, Diane Nam, Albert Yee, Daniel B Whelan, Lisa M Wild, Ryan M Khan, Cathy Coady, David Amirault, Glen Richardson, Gwen Dobbin, Ryan Bicknell, Jeff Yach, Davide Bardana, Gavin Wood, Mark Harrison, David Yen, Sue Lambert, Fiona Howells, Angela Ward, Paul Zalzal, Heather Brien, V Naumetz, Brad Weening, Eugene K Wai, Steve Papp, Wade T Gofton, Stephen P Kingwell, Garth Johnson, Joseph O’Neil, Darren M Roffey, Vivian Borsella, Todd M Oliver, Vicki Jones, Terrence J Endres, Samuel G Agnew, Kyle J Jeray, J. Scott Broderick, David R Goetz, Thomas B Pace, Thomas M Schaller, Scott E Porter, Stephanie L Tanner, Rebecca G Snider, Lauren A Nastoff, Shea A Bielby, Julie A Switzer, Peter A Cole, Sarah A Anderson, Paul M Lafferty, Mengnai Li, Thuan V Ly, Scott B Marston, Amy L Foley, Sandy Vang, David M Wright, Andrew J Marcantonio, Michael SH Kain, Richard Iorio, Lawrence M Specht, John F Tilzey, Margaret J Lobo, John S Garfi, Heather A Vallier, Andrea Dolenc, Chalitha Robinson, Michael J Prayson, Richard Laughlin, L. Joseph Rubino, Jedediah May, Geoffrey Ryan Rieser, Liz Dulaney-Cripe, Chris Gayton, John T Gorczyca, Jonathan M Gross, Catherine A Humphrey, Stephen Kates, Krista Noble, Allison W McIntyre, Kaili Pecorella, Craig A Davis, Stephen Lindenbaum, John Schwappach, Janell K Baker, Tori Rutherford, Heike Newman, Shane Lieberman, Erin Finn, Kristin Robbins, Meghan Hurley, Lindsey Lyle, Khalis Mitchell, Kieran Browner, Erica Whatley, Krystal Payton, Christina Reeves, Lisa K Cannada, David Karges, Leslie Hill, John Esterhai, Annamarie D Horan, Christine A Kaminski, Brynn N Kowalski, Jonathan P Keeve, Christopher G Anderson, Michael D McDonald, Jodi M Hoffman, Ivan Tarkin, Peter Siska, Gary Gruen, Andrew Evans, Dana J Farrell, James Irrgang, Arlene Luther, William W Cross, Joseph R Cass, Stephen A Sems, Michael E Torchia, Tyson Scrabeck, Mark Jenkins, Jules Dumais, Amanda W Romero, Carlos A Sagebien, Mark S Butler, James T Monica, Patricia Seuffert, Joseph R Hsu, James Ficke, Michael Charlton, Matthew Napierala, Mary Fan, Chadi Tannoury, Michael Archdeacon, Ryan Finnan, Toan Le, John Wyrick, Shelley Hess, Michael L Brennan, Robert Probe, Evelyn Kile, Kelli Mills, Lydia Clipper, Michelle Yu, Katie Erwin, Daniel Horwitz, Kent Strohecker, Teresa K Swenson, Andrew H Schmidt, Jerald R Westberg, Kamran Aurang, Gary Zohman, Brett Peterson, Roger B Huff, Joseph Baele, Timothy Weber, Matt Edison, Jessica McBeth, Janos P Ertl, J. Andrew Parr, Molly M Moore, Erin Tobias, Emily Thomas, Charles J DePaolo, Leslie E Shell, Lynne Hampton, Stephanie Shepard, Tracy Nanney, Claudine Cuento, Robert V Cantu, Eric R Henderson, Linda S Eickhoff, E. Mark Hammerberg, Philip Stahel, David Hak, Cyril Mauffrey, Douglas Gibula, Hannah Gissel, Corey Henderson, David P Zamorano, Martin C Tynan, Deanna Lawson, Brett D Crist, Yvonne M Murtha, Linda K Anderson, Colleen Linehan, Lindsey Pilling, Courtland G Lewis, Raymond J Sullivan, Elizabeth Roper, William Obremskey, Philip Kregor, Justin E Richards, Kenya Stringfellow, Michael P Dohm, Abby Zellar, Michiel JM Segers, Jacco AC Zijl, Bart Verhoeven, Anke B Smits, Jean Paul PM de Vries, Bram Fioole, Henk van der Hoeven, Evert BM Theunissen, Tammo S de Vries Reilingh, Lonneke Govaert, Philippe Wittich, Maurits de Brauw, Jan Wille, Peter M.N.Y.M. Go, Ewan D Ritchie, Ronald N Wessel, Eric R Hammacher, Gijs A Visser, Heyn Stockmann, Rob Silvis, Jaap P Snellen, Bram Rijbroek, Joris JG Scheepers, Erik GJ Vermeulen, Michiel PC Siroen, Ronald Vuylsteke, Hans LF Brom, Herman Rijna, Piet AR de Rijcke, Cees L Koppert, Steven E Buijk, Richard PR Groenendijk, Imro Dawson, Geert WM Tetteroo, Milko MM Bruijninckx, Pascal G Doornebosch, Eelco JR de Graaf, Maarten van der Elst, Carmen C van der Pol, Martijne van’t Riet, Tom M Karsten, Mark R de Vries, Laurents PS Stassen, Niels WL Schep, G Ben Schmidt, W H Hoffman, Frank H.W.M. van der Heijden, W. Jaap Willems, Cor P van der Hart, Kahn Turckan, Sebastiaan Festen, Frank de Nies, Nico JM Out, Jan Bosma, Albert van Kampen, Jan Biert, Arie B van Vugt, Michael JR Edwards, Taco J Blokhuis, Jan Paul M Frölke, Leo MG Geeraedts, Jean WM Gardeniers, Edward T.C.H. Tan, Lodewijk M.S.J. Poelhekke, Maarten C de Waal Malefijt, Bart Schreurs, Gert R Roukema, Hong A Josaputra, Paul Keller, Peter D de Rooij, Hans Kuiken, Han Boxma, Berry I Cleffken, Ronald Liem, Steven J Rhemrev, Coks HR Bosman, Alexander de Mol van Otterloo, Jochem Hoogendoorn, Alexander C de Vries, Sven AG Meylaerts, Michiel HJ Verhofstad, Joost Meijer, Teun van Egmond, Igor van der Brand, Martin G Eversdijk, Rolf Peters, Dennis Den Hartog, Oscar JF Van Waes, Pim Oprel, Martin Campo, Ronald Verhagen, G.H. Robert Albers, Rogier KJ Simmermacher, Jeroen van Mulken, Karlijn van Wessem, Steven M van Gaalen, Luke PH Leenen, Maarten W.G.A. Bronkhorst, Onno R Guicherit, J. Carel Goslings, Kees Jan Ponsen, Mahesh Bhatia, Vinod Arora, Vivek Tyagi, Ajay Gupta, Neeraj Jain, Farah Khan, Ateet Sharma, Amir Sanghavi, Mittal Trivedi, Anil Rai, null Subash, Kamal Rai, Vineet Yadav, Sanjay Singh, Amal Shankar Prasad, Vimlesh Mishra, D C Sundaresh, Angshuman Khanna, Joe Joseph Cherian, Davy J Olakkengil, Gaurav Sharma, Akhil Dadi, Naveen Palla, Utsav Ganguly, B. Sachidananda Rai, Janakiraman Rajakumar, Peter Hull, Sophie Lewis, Simone Evans, Rajesh Nanda, Rajanikanth Logishetty, Sanjeev Anand, Carol Bowler, Andrew Jennings, Graham Chuter, Glynis Rose, Gillian Horner, Callum Clark, Kate Eke, Mike Reed, Chris Herriott, Christine Dobb, Hamish Curry, Greg Etherington, Arvind Jain, Ash Moaveni, Matthias Russ, Geoff Donald, Patrick Weinrauch, Paul Pincus, Steven Yang, Brett Halliday, Trevor Gervais, Michael Holt, Annette Flynn, Marinis Pirpiris, David Love, Andrew Bucknill, Richard J Farrugia, Torben Ianssen, Asgeir Amundsen, Jan Egil Brattgjerd, Tor Borch, Berthe Bøe, Bernhard Flatøy, Sondre Hasselund, Knut Jørgen Haug, Kim Hemlock, Tor Magne Hoseth, Geir Jomaas, Thomas Kibsgård, Tarjei Lona, Gilbert Moatshe, Oliver Müller, Marius Molund, Tor Nicolaisen, Fredrik Nilsen, Jonas Rydinge, Morten Smedsrud, Are Stødle, Axel Trommer, Stein Ugland, Anders Karlsten, Guri Ekås, Hans-Christoph Pape, Matthias Knobe, Roman Pfeifer, Orthopedic Surgery and Sports Medicine, Graduate School, Other departments, Surgery, Other Research, Amsterdam Movement Sciences, Cardiothoracic Surgery, and Emergency Medicine

Subjects
Male, medicine.medical_specialty, WOMAC, Abstracting and Indexing, Osteoarthritis, Cronbach's alpha, Surveys and Questionnaires, medicine, Humans, Orthopedics and Sports Medicine, Clinical significance, Femoral neck, Aged, 80 and over, Ontario, business.industry, Reproducibility of Results, Construct validity, General Medicine, medicine.disease, RELIABILITY VALIDITY, Femoral Neck Fractures, Reconstructive and regenerative medicine Radboud Institute for Health Sciences [Radboudumc 10], Clinical trial, Reconstructive and regenerative medicine Radboud Institute for Molecular Life Sciences [Radboudumc 10], medicine.anatomical_structure, Physical therapy, Female, Surgery, business
Abstract

Item does not contain fulltext BACKGROUND: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been extensively evaluated in groups of patients with osteoarthritis, yet not in patients with a femoral neck fracture. This study aimed to determine the reliability, construct validity, and responsiveness of the WOMAC compared with the Short Form-12 (SF-12) and the EuroQol 5D (EQ-5D) questionnaires for the assessment of elderly patients with a femoral neck fracture. METHODS: Reliability was tested by assessing the Cronbach alpha. Construct validity was determined with the Pearson correlation coefficient. Change scores were calculated from ten weeks to twelve months of follow-up. Standardized response means and floor and ceiling effects were determined. Analyses were performed to compare the results for patients less than eighty years old with those for patients eighty years of age or older. RESULTS: The mean WOMAC total score was 89 points before the fracture in the younger patients and increased from 70 points at ten weeks to 81 points at two years postoperatively. In the older age group, these scores were 86, 75, and 78 points. The mean WOMAC pain scores before the fracture and at ten weeks and two years postoperatively were 92, 76, and 87 points, respectively, in the younger age group and 92, 84, and 93 points in the older age group. Function scores were 89, 68, and 79 points for the younger age group and 84, 71, and 73 points for the older age group. The Cronbach alpha for pain, stiffness, function, and the total scale ranged from 0.83 to 0.98 for the younger age group and from 0.79 to 0.97 for the older age group. Construct validity was good, with 82% and 79% of predefined hypotheses confirmed in the younger and older age groups, respectively. Responsiveness was moderate. No floor effects were found. Moderate to large ceiling effects were found for pain and stiffness scales at ten weeks and twelve months in younger patients (18% to 36%) and in the older age group (38% to 53%). CONCLUSIONS: The WOMAC showed good reliability, construct validity, and responsiveness in both age groups of elderly patients with a femoral neck fracture who had been physically and mentally fit before the fracture. The instrument is suitable for use in future clinical studies in these populations. CLINICAL RELEVANCE: The results are based on two clinical trials. The questionnaires used concern pure, clinically relevant issues (ability to walk, climb stairs, etc.). Moreover, the results can be used for future research comparing clinical outcomes (or treatments) for populations with a femoral neck fracture.

Published
2015

15. Proximal humerus fractures in the pediatric population: a systematic review

Author

Harish S. Hosalkar, Keith D. Baldwin, Nirav K. Pandya, Surena Namdari, and Sohrab Pahlavan

Subjects
Operative and non-operative, medicine.medical_specialty, Proximal humerus, medicine.medical_treatment, Poison control, Proximal humerus fracture, Asymptomatic, Occupational safety and health, Paediatrics and Reproductive Medicine, Clinical Research, Injury prevention, medicine, Original Clinical Article, Orthopedics and Sports Medicine, Pediatrics, Perinatology, and Child Health, Children, Reduction (orthopedic surgery), Pediatric, business.industry, Injuries and accidents, Surgery, Orthopedics, Pediatrics, Perinatology and Child Health, Orthopedic surgery, medicine.symptom, business, Pediatric population
Abstract

Purpose Proximal humerus fractures and epiphyseal separations in skeletally immature children and adolescents are traditionally treated non-operatively. Recently, authors have described the operative fixation of these injuries, particularly in older children and adolescents with displaced fractures. We performed a systematic review of the literature to identify operative indications for proximal humerus fractures in children and to compare the results by age, displacement, and treatment modality. Methods A systematic review of the literature from January 1960 to April 2010 was performed. All studies with patients under the age of 18 years who were treated for a proximal humerus fracture either operatively or non-operatively were included. Results The available literature is largely composed of uncontrolled case series (Level IV). According to findings, the literature shows that asymptomatic union is the rule in proximal humerus fractures in children and adolescents. Poorer outcomes were noted in operatively treated patients, patients with more displaced fractures, and older patients. Conclusions The currently available literature supports a non-operative treatment approach, particularly in younger children with more growth remaining. Older patients (>13 years) with more widely displaced fractures may benefit from anatomic reduction with stabilization, though the data in the literature at this point is too weak to strongly recommend this approach. Further analysis with a more rigorous scientific method is necessary to evaluate the optimum treatment modality in this subgroup.

Published
2011

16. Texture coding in the rat whisker system: slip-stick versus differential resonance

Author

Daniel Hill, J. H. Wolfe, Daniel E. Feldman, Patrick J. Drew, David Kleinfeld, Sohrab Pahlavan, and Stanley, Garrett B

Subjects
QH301-705.5, Whiskers, Acoustics, Somatosensory, Slip (materials science), Biology, Vibration, Medical and Health Sciences, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, 0302 clinical medicine, Whisker, Models, Neural Pathways, Animals, Mechanical resonance, Biology (General), Evoked Potentials, 030304 developmental biology, 0303 health sciences, Afferent Pathways, General Immunology and Microbiology, Agricultural and Veterinary Sciences, General Neuroscience, Whisking in animals, Resonance, Anatomy, Somatosensory Cortex, Biological Sciences, Biological, Rats, Brain Disorders, Amplitude, Vibrissae, Exploratory Behavior, General Agricultural and Biological Sciences, Mechanoreceptors, 030217 neurology & neurosurgery, Developmental Biology
Abstract

Rats discriminate surface textures using their whiskers (vibrissae), but how whiskers extract texture information, and how this information is encoded by the brain, are not known. In the resonance model, whisker motion across different textures excites mechanical resonance in distinct subsets of whiskers, due to variation across whiskers in resonance frequency, which varies with whisker length. Texture information is therefore encoded by the spatial pattern of activated whiskers. In the competing kinetic signature model, different textures excite resonance equally across whiskers, and instead, texture is encoded by characteristic, nonuniform temporal patterns of whisker motion. We tested these models by measuring whisker motion in awake, behaving rats whisking in air and onto sandpaper surfaces. Resonant motion was prominent during whisking in air, with fundamental frequencies ranging from approximately 35 Hz for the long Delta whisker to approximately 110 Hz for the shorter D3 whisker. Resonant vibrations also occurred while whisking against textures, but the amplitude of resonance within single whiskers was independent of texture, contradicting the resonance model. Rather, whiskers resonated transiently during discrete, high-velocity, and high-acceleration slip-stick events, which occurred prominently during whisking on surfaces. The rate and magnitude of slip-stick events varied systematically with texture. These results suggest that texture is encoded not by differential resonant motion across whiskers, but by the magnitude and temporal pattern of slip-stick motion. These findings predict a temporal code for texture in neural spike trains.

Published
2008

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