Physical Sciences and Mathematics Commons^™

Stellar Mass–Gas-Phase Metallicity Relation At 0.5 ≤ Z ≤ 0.7: A Power Law With Increasing Scatter Toward The Low-Mass Regime, Yicheng Guo, David C. Koo, Yu Lu, John C. Forbes, Marc Rafelski, Jonathan R. Trump, Ricardo Amorín, Guillermo Barro, Romeel Davé, S. M. Faber, Nimish P. Hathi, Hassen Yesuf, Michael C. Cooper, Avishai Dekel, Puragra Guhathakurta, Evan N. Kirby, Anton M. Koekemoer, Pablo G. Pérez-González, Lihwai Lin, Jeffery A. Newman, Joel R. Primack, David J. Rosario, Christopher N. A. Willmer, Renbin Yan

Physics and Astronomy Faculty Publications

We present the stellar mass (M_*)–gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5 ≤ z ≤ 0.7) for for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given M_* of this magnitude-limited (R ≲ 24 AB) sample are representative of normal star-forming galaxies. For masses below 10⁹ M_☉ our sample of 237 galaxies is ~10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and its scatter …

Crystal Structures Of (Z)-5-[2-(Benzo[B]Thiophen-2-Yl)-1-(3,5-Dimethoxyphenyl)Ethenyl]-1H-Tetrazole And (Z)-5-[2-(Benzo[B]Thiophen-3-Yl)-1-(3,4,5-Trimethoxyphenyl)Ethenyl]-1H-Tetrazole, Narsimha Reddy Penthala, Jaishankar K. B. Yadlapalli, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

(Z)-5-[2-(Benzo[b]thio­phen-2-yl)-1-(3,5-di­meth­oxy­phen­yl)ethen­yl]-1H-tetrazole methanol monosolvate, C₁₉H₁₆N₄O₂S·CH₃OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thio­phen-2-yl)-2-(3,5-di­meth­oxy­phen­yl)acrylo­nitrile with tri­butyl­tin azide via a [3 + 2]cyclo­addition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thio­phen-3-yl)-1-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]-1H-tetra­zole, C₂₀H₁₈N₄O₃S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thio­phen-3-yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­nitrile with tri­butyl­tin azide. Crystals of (I) have two mol­ecules in the asymmetric unit (Z′ = 2), whereas crystals of (II) have Z′ …

To Bend Or Not To Bend – Are Heteroatom Interactions Within Conjugated Molecules Effective In Dictating Conformation And Planarity?, Gary Conboy, Howard J. Spencer, Enrico Angioni, Alexander L. Kanibolotsky, Neil J. Findlay, Simon J. Coles, Claire Wilson, Mateusz B. Pitak, Chad Risko, Veaceslav Coropceanu, Jean-Luc Brédas, Peter J. Skabara

Chemistry Faculty Publications

We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability.

Direct Imaging Of Coexisting Ordered And Frustrated Sublattices In Artificial Ferromagnetic Quasicrystals, Barry Farmer, Vinayak Shantaram Bhat, Eric Teipel, J. Unguris, D. J. Keavney, Jeffrey Todd Hastings, Lance E. De Long

Physics and Astronomy Faculty Publications

We have used scanning electron microscopy with polarization analysis and photoemission electron microscopy to image the two-dimensional magnetization of permalloy films patterned into Penrose P2 tilings (P2T). The interplay of exchange interactions in asymmetrically coordinated vertices and short-range dipole interactions among connected film segments stabilize magnetically ordered, spatially distinct sublattices that coexist with frustrated sublattices at room temperature. Numerical simulations that include long-range dipole interactions between sublattices agree with images of as-grown P2T samples and predict a magnetically ordered ground state for a two-dimensional quasicrystal lattice of classical Ising spins.

Ground-State Tuning Of Metal-Insulator Transition By Compositional Variations In Bair1−XRuXO3 (0 ≤ X ≤ 1), Shujuan Yuan, Kamal H. Butrouna, Jsaminka Terzic, Hao Zheng, Saicharan Aswartham, Lance E. Delong, Feng Ye, P. Schlottmann, Gang Cao

Physics and Astronomy Faculty Publications

Hexagonal BaIrO3 is a magnetic insulator driven by the spin-orbit interaction (SOI), whereas BaRuO₃ is an enhanced paramagnetic metal. Our investigation of structural, magnetic, transport, and thermal properties reveals that substitution of Ru⁴⁺ (4d⁴) ions for Ir⁴⁺ (5d⁵) ions in BaIrO₃ reduces the magnitudes of the SOI and a monoclinic structural distortion and rebalances the competition between the SOI and the lattice degrees of freedom to render an evolution from a magnetic insulting state to a robust metallic state. The central findings of this paper are as follows: (1) light …

An Apparatus For Studying Electrical Breakdown In Liquid Helium At 0.4 K And Testing Electrode Materials For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, T. M. Ito, J. C. Ramsey, W. Yao, D. H. Beck, V. Cianciolo, S. M. Clayton, Christopher B. Crawford, S. A. Currie, B. W. Filippone, W. C. Griffith, M. Makela, R. Schmid, G. M. Seidel, Z. Tang, D. Wagner, W. Wei, S. E. Williamson

Physics and Astronomy Faculty Publications

We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ∼600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1–2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures …

Hallmarks Of The Mott-Metal Crossover In The Hole-Doped Pseudospin-1/2 Mott Insulator Sr2Iro4, Yue Cao, Qiang Wang, Justin A. Waugh, Theodore J. Reber, Haoxiang Li, Xiaoqing Zhou, Stephen Parham, S. -R. Park, Nicholas C. Plumb, Eli Rotenberg, Aaron Bostwick, Jonathan D. Denlinger, Tongfei Qi, Michael A. Hermele, Gang Cao, Daniel S. Dessau

Physics and Astronomy Faculty Publications

The physics of doped Mott insulators remains controversial after decades of active research, hindered by the interplay among competing orders and fluctuations. It is thus highly desired to distinguish the intrinsic characters of the Mott-metal crossover from those of other origins. Here we investigate the evolution of electronic structure and dynamics of the hole-doped pseudospin-1/2 Mott insulator Sr₂IrO₄. The effective hole doping is achieved by replacing Ir with Rh atoms, with the chemical potential immediately jumping to or near the top of the lower Hubbard band. The doped iridates exhibit multiple iconic low-energy features previously observed …

Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang

Geography Faculty Publications

Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …

H, He-Like Recombination Spectra – I. L-Changing Collisions For Hydrogen, Francisco Guzmán, N. R. Badnell, R. J. R. Williams, P. A. M. Van Hoof, Marios Chatzikos, Gary J. Ferland

Physics and Astronomy Faculty Publications

Hydrogen and helium emission lines in nebulae form by radiative recombination. This is a simple process which, in principle, can be described to very high precision. Ratios of He I and H I emission lines can be used to measure the He⁺/H⁺ abundance ratio to the same precision as the recombination rate coefficients. This paper investigates the controversy over the correct theory to describe dipole l-changing collisions (nl → nl′ = l ± 1) between energy-degenerate states within an n-shell. The work of Pengelly & Seaton has, for half-a-century, been considered the definitive …

Photocatalytic Reduction Of Fumarate To Succinate On Zns Mineral Surfaces, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

The reductive tricarboxylic acid (rTCA) cycle is an important central biosynthetic pathway that fixes CO₂ into carboxylic acids. Among the five reductive steps in the rTCA cycle, the two-electron reduction of fumarate to succinate proceeds nonenzymatically on the surface of photoexcited sphalerite (ZnS) colloids suspended in water. This model reaction is chosen to systematically study the surface photoprocess occurring on ZnS in the presence of [Na₂S] (1–10 mM) hole scavenger at 15 °C. Experiments at variable pH (5–10) indicate that monodissociated fumaric acid is the primary electron acceptor forming the monoprotic form of succinic acid. The following …

Spatio-Temporal Linear Stability Analysis Of Stratified Planar Wakes: Velocity And Density Asymmetry Effects, Benjamin Emerson, Swapnil Jagtap, J. Mathew Quinlan, Michael W. Renfro, Baki M. Cetegen, Tim Lieuwen

Mechanical Engineering Faculty Publications

This paper explores the hydrodynamic stability of bluff body wakes with non-uniform mean density, asymmetric mean density, and velocity profiles. This work is motivated by experiments [S. Tuttle et al., “Lean blow off behavior of asymmetrically-fueled bluff body-stabilized flames,” Combust. Flame 160, 1677 (2013)], which investigated reacting wakes with equivalence ratio stratification and, hence, asymmetry in the base flow density profiles. They showed that highly stratified cases exhibited strong, narrowband oscillations, suggestive of global hydrodynamic instability. In this paper, we present a local hydrodynamic stability analysis for non-uniform density wakes that includes base flow asymmetry. The results show …

Measurement Of The Transverse Single-Spin Asymmetry In P↑+P→W±/Z0 At Rhic, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at √s = 500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

Conducting Laalo3/Srtio3 Heterointerfaces On Atomically-Flat Substrates Prepared By Deionized-Water, John G. Connell, J. Nichols, John H. Gruenewald, D. -W. Kim, Sung S. Ambrose Seo

Physics and Astronomy Faculty Publications

We have investigated how the recently-developed water-leaching method for atomically-flat SrTiO₃ (STO) substrates affects the transport properties of LaAlO₃ (LAO) and STO heterointerfaces. Using pulsed laser deposition at identical growth conditions, we have synthesized epitaxial LAO thin-films on two different STO substrates, which are prepared by water-leaching and buffered hydrofluoric acid (BHF) etching methods. The structural, transport, and optical properties of LAO/STO heterostructures grown on water-leached substrates show the same high-quality as the samples grown on BHF-etched substrates. These results indicate that the water-leaching method can be used to grow complex oxide heterostructures with atomically well-defined heterointerfaces without …

Uncovering Local Trends In Genetic Effects Of Multiple Phenotypes Via Functional Linear Models, Olga A. Vsevolozhskaya, Dmitri V. Zaykin, David A. Barondess, Xiaoren Tong, Sneha Jadhav, Qing Lu

Biostatistics Faculty Publications

Recent technological advances equipped researchers with capabilities that go beyond traditional genotyping of loci known to be polymorphic in a general population. Genetic sequences of study participants can now be assessed directly. This capability removed technology-driven bias toward scoring predominantly common polymorphisms and let researchers reveal a wealth of rare and sample-specific variants. Although the relative contributions of rare and common polymorphisms to trait variation are being debated, researchers are faced with the need for new statistical tools for simultaneous evaluation of all variants within a region. Several research groups demonstrated flexibility and good statistical power of the functional linear …

A No-Math Method Of Calibrating Backpack Sprayers And Lawn Care Spray Guns, Gregg Munshaw

Agriculture and Natural Resources Publications

Calibrating application equipment is something many people avoid because they believe it is too time consuming or that the math involved in the process is confusing. Calibration, however, is critical. Applying too much can be bad for the environment, injure the grass, and also wastes money. Applying too little can result in poor pest control and can lead to pesticide resistance. There are several methods that will calibrate sprayers but the no-math method is likely the most simple and reduces the chance of errors.

Understanding Produce Safety Programs And Making A Food Safety Plan, Paul Priyesh Vijayakumar, Melissa Newman, Pam Sigler

Agriculture and Natural Resources Publications

Safety of fresh vegetables and fruits is very important because these products are often consumed raw or are minimally processed. Unlike meats, fresh fruits and vegetables do not always undergo a cooking step to ensure that foodborne pathogens are killed before consuming. For the safety of consumers, farmers who produce our food must know the best practices available to produce, process, handle, and store fresh produce.

Notes On Contributions To The Science Of Rare Earth Element Enrichment In Coal And Coal Combustion Byproducts, James C. Hower, Evan J. Granite, David B. Mayfield, Ari S. Lewis, Robert B. Finkelman

Center for Applied Energy Research Faculty and Staff Publications

Coal and coal combustion byproducts can have significant concentrations of lanthanides (rare earth elements). Rare earths are vital in the production of modern electronics and optics, among other uses. Enrichment in coals may have been a function of a number of processes, with contributions from volcanic ash falls being among the most significant mechanisms. In this paper, we discuss some of the important coal-based deposits in China and the US and critique classification systems used to evaluate the relative value of the rare earth concentrations and the distribution of the elements within the coals and coal combustion byproducts.

X-Ray Absorption Spectroscopy Study Of The Effect Of Rh Doping In Sr2Iro4, C. H. Sohn, Deok-Yong Cho, C. -T. Kuo, L. J. Sandilands, Tongfei Qi, Gang Cao, T. W. Noh

Center for Advanced Materials Faculty Publications

We investigate the effect of Rh doping in Sr₂IrO₄ using X-ray absorption spectroscopy (XAS). We observed appearance of new electron-addition states with increasing Rh concentration (x in Sr₂Ir_1−xRh_xO₄) in accordance with the concept of hole doping. The intensity of the hole-induced state is however weak, suggesting weakness of charge transfer (CT) effect and Mott insulating ground states. Also, Ir J_eff = 1/2 upper Hubbard band shifts to lower energy as x increases up to x = 0.23. Combined with optical spectroscopy, these results suggest a hybridisation-related mechanism, in …

Poster Session, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

1. Fecal Coliforms and E. coli Levels in Surface Waters from McConnell Springs, 2011-2015, David Price, Division of Water Quality, Lexington-Fayette County Government
2. Buried Soils as an Important Control on C Storage along Human-Impacted Floodplains in Kentucky, USA, Ashley Casselberry and Gary Stinchcomb, Dept. of Geosciences & Watershed Studies Institute, Murray State University
3. Buried Soils are an Important Chemical Interface Controlling Mineral Weathering and Solute Gradients along River Corridors, Gary Stinchcomb, Ashley Casselberry, and Abigail Smith, Dept. of Geosciences & Watershed Studies Institute, Murray State University
4. Geospatial Evaluation of Sewer Gas to Indoor Air Pathways Relevant for Vapor …

Track 2: Stream Restoration, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Bankfull Open Channel Flow Model: Development and Applications for Stream Restoration Design, Charles Davis and Brian Belcher, Beaver Creek Hydrology, LLC, Lexington, KY
• Using Stream Restoration for Pollution Reduction, Wanda Lawson, Stantec Consulting Services, Inc, Louisville, KY
• KDFWR Hatchery Creek Stream and Wetlands Restoration Project - A Unique Opportunity to Maximize Trout Habitat, Create Recreational Opportunities and Provide Mitigation Credits: Planning & Design, Oakes Routt and others, Stantec Consulting Services, Inc., Louisville, KY
• KDFWR Hatchery Creek Stream and Wetlands Restoration Project - A Unique Opportunity to Maximize Trout Habitat, Create Recreational Opportunities and Provide Mitigation Credits: Construction …

Track 2: Environmental Impact, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Toward Rapid Detection of Phytophthora cinnamomi in Appalachian Streams, Kenton Sena and others, Dept. of Forestry, University of Kentucky
• Arsenic in Water and Risk of Cancer in Humans, Steven Lamm and others, Center for Epidemiology and Global Health, Washington, DC
• Examining the Impacts of Valley Fills in Stream Ecosystems on Amphibian and Aquatic Insect Communities in Southeastern Kentucky, John Bourne and Stephen Richter, Patuxent Research Refuge, Laurel, MD and Eastern Kentucky University
• The Wetlands Prioritization Tool, Caroline Chan, Kentucky Division of Water, Frankfort, KY

Track 2: Soils, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Controlled Drainage in Western Kentucky: Mitigating Water Stress and Reducing Nutrient Loss to Surface Waters in Grain Crop Production, Ethan Snyder and Carrie Knott, Dept. of Plant and Soil Sciences, University of Kentucky
• Comparing Simulated Soil Properties to Field Derived Values in Forested and Grassland Catena of MLRA 120, Trinity Baker and others, Dept. of Plant and Soil Sciences, University of Kentucky
• Soil Infiltration Rates in Six Agricultural Fields of Western Kentucky, Landon Gibbs and Iin Handayani, Dept. of Agricultural Science, Murray State University
• Investigation of the Climate Modeling Factors Impacting Forecasted Streamflow for Central Kentucky, …

Track 1: Source Water Protection, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Kentucky's Source Water Protection Assistance Program, Robert Blair and James Calhoun, Watershed Management Branch, Kentucky Division of Water and Jessica Moore, U.S. EPA, Dallas Texas
• Source Water Protection Assistance Program, Trimble County Water District #1 Customer Outreach Program, Andrew Stark, Trimble County Water District #1, Bedford, KY
• Kentucky Rural Water Association and Water Utilities' Efforts in Protecting Drinking Water Sources, Jack Stickney, Kentucky Rural Water Association, Bowling Green, KY
• Source Water Protection for the Riverbank Filtration System, Kay Ball and Rob Newman, Louisville Water Company, Louisville, KY

Track 1: Karst, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Characteristics of Cover-Collapse Sinkholes in Kentucky, James C. Currens, Kentucky Geological Survey
• Data and Model Investigation of a Fluviokarst System in the Bluegrass Region: Water, Sediment, and Carbon Interactions, Admin Husic and others, Dept. of Civil Engineering, University of Kentucky
• Sourcing and Dynamics of Karst Hydrologic Inputs on Harmful Algal Bloom Occurrences in Kentucky Lakes, Robert Schaefer and Jason Polk, Dept. of Geography and Geology, Western Kentucky University
• Investigation of Fecal Contamination in the Little River Basin, Kentucky Using Microbial Source Tracking and Fecal Indicator Bacteria, 2013-2014, Mac A. Cherry, USGS, Kentucky Water Science Center

Track 1: Groundwater, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Proposed Bill to License Closed-Loop Geothermal System Vertical Borehole Well Drillers, Bart Davidson, Kentucky Geological Survey, David Jackson and Scotty Robertson, Kentucky Division of Water
• Using Oil and Gas Data to Assess the Distribution of Fresh and Saline Water in Northeastern Kentucky, Ethan Davis, Kentucky Geological Survey
• A Pilot Study to Assess Baseline Groundwater Chemistry for the Berea Sandstone and Rogersville Shale Play Area, Eastern Kentucky, Junfeng Zhu and others, Kentucky Geological Survey
• Investigation of Limestone Aquifer Characteristics in the Elizabethtown, Kentucky Area, Chuck Taylor and others, Kentucky Geological Survey

Plenary Session: Working With Flint Residents: Lead Discovery And Citizen Science In The Flint Water Crisis, Min Tang

Kentucky Water Resources Annual Symposium

No abstract provided.

Proceedings Of 2016 Kentucky Water Resources Annual Symposium, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

This symposium was planned and conducted as a part of the state water resources research institute annual program that is supported by Grant/Cooperative Agreement Number G11AP20081 from the United States Geological Survey. The contents of this proceedings document and the views and conclusions presented at the symposium are solely the responsibility of the individual authors and presenters and do not necessarily represent the official views of the USGS or of the symposium organizers and sponsors. This publication is produced with the understanding that the United States Government is authorized to reproduce and distribute reprints for government purposes.

Narrow Nucleon-Ψ(2S) Bound State And Lhcb Pentaquarks, Michael I. Eides, Victor Yu. Petrov, Maxim V. Polyakov

Physics and Astronomy Faculty Publications

We interpret the newly discovered pentaquark P_c(4450) as a bound state of charmonium ψ(2S) and the nucleon. The binding potential is due to the charmonium-nucleon interaction that in the heavy quark approximation is proportional to the product of the charmonium chromoelectric polarizability and the nucleon energy-momentum distribution. We use the large Nc expansion to estimate the quarkonium polarizability and calculate the nucleon properties in the framework of the mean-field picture of light baryons. Two almost degenerate states J^P=(1/2)⁻ and J^P=(3/2)⁻ are predicted at the position of the P_{c …}

Direct Collapse To Supermassive Black Hole Seeds: Comparing The Amr And Sph Approaches, Yang Luo, Kentaro Nagamine, Isaac Shlosman

Physics and Astronomy Faculty Publications

We provide detailed comparison between the adaptive mesh refinement (AMR) code ENZO-2.4 and the smoothed particle hydrodynamics (SPH)/N-body code GADGET-3 in the context of isolated or cosmological direct baryonic collapse within dark matter (DM) haloes to form supermassive black holes. Gas flow is examined by following evolution of basic parameters of accretion flows. Both codes show an overall agreement in the general features of the collapse; however, many subtle differences exist. For isolated models, the codes increase their spatial and mass resolutions at different pace, which leads to substantially earlier collapse in SPH than in AMR cases due …

Correlation Of Maximal Inspiratory Pressure To Transdiaphragmatic Twitch Pressure In Intensive Care Unit Patients, Gerald S. Supinski, Philip M. Westgate, Leigh Ann Callahan

Internal Medicine Faculty Publications

Background: Respiratory muscle weakness contributes to respiratory failure in ICU patients. Unfortunately, assessment of weakness is difficult since the most objective test, transdiaphragmatic pressure in response to phrenic nerve stimulation (PdiTw), is difficult to perform. While most clinicians utilize maximum inspiratory pressure (Pimax) to assess strength, the relationship of this index to PdiTw has not been evaluated in a large ICU population. The purpose of the present study was to assess both PdiTw and Pimax in ICU patients to determine how these indices correlate with each other, what factors influence these indices, and how well these indices predict outcomes.

Methods: …