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Erickson M, Casañola-Martin G, Han Y, Rasulev B, Kilin D. Relationships between the Photodegradation Reaction Rate and Structural Properties of Polymer Systems. J Phys Chem B 2024; 128:2190-2200. [PMID: 38386478 DOI: 10.1021/acs.jpcb.3c06854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The development of reusable polymeric materials inspires an attempt to combine renewable biomass with upcycling to form a biorenewable closed system. It has been reported that 2,5-furandicarboxylic acid (FDCA) can be recovered for recycling when incorporated as monomers into photodegradable polymeric systems. Here, we develop a procedure to better understand the photodegradation reactions combining density functional theory (DFT) based time-dependent excited-state molecular dynamics (TDESMD) studies with machine learning-based quantitative structure-activity relationships (QSAR) methodology. This procedure allows for the unveiling of hidden structural features between active orbitals that affect the rate of photodegradation and is coined InfoTDESMD. Findings show that electrotopological features are influential factors affecting the rate of photodegradation in differing environments. Additionally, statistical validations and knowledge-based analysis of descriptors are conducted to further understand the structural features' influence on the rate of photodegradation of polymeric materials.
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Affiliation(s)
- Meade Erickson
- Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Gerardo Casañola-Martin
- Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Yulun Han
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Bakhtiyor Rasulev
- Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Dmitri Kilin
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58105, United States
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Pak A, Zylstra AB, Baker KL, Casey DT, Dewald E, Divol L, Hohenberger M, Moore AS, Ralph JE, Schlossberg DJ, Tommasini R, Aybar N, Bachmann B, Bionta RM, Fittinghoff D, Gatu Johnson M, Geppert Kleinrath H, Geppert Kleinrath V, Hahn KD, Rubery MS, Landen OL, Moody JD, Aghaian L, Allen A, Baxamusa SH, Bhandarkar SD, Biener J, Birge NW, Braun T, Briggs TM, Choate C, Clark DS, Crippen JW, Danly C, Döppner T, Durocher M, Erickson M, Fehrenbach T, Freeman M, Havre M, Hayes S, Hilsabeck T, Holder JP, Humbird KD, Hurricane OA, Izumi N, Kerr SM, Khan SF, Kim YH, Kong C, Jeet J, Kozioziemski B, Kritcher AL, Lamb KM, Lemos NC, MacGowan BJ, Mackinnon AJ, MacPhee AG, Marley EV, Meaney K, Millot M, Di Nicola JMG, Nikroo A, Nora R, Ratledge M, Ross JS, Shin SJ, Smalyuk VA, Stadermann M, Stoupin S, Suratwala T, Trosseille C, Van Wonterghem B, Weber CR, Wild C, Wilde C, Wooddy PT, Woodworth BN, Young CV. Observations and properties of the first laboratory fusion experiment to exceed a target gain of unity. Phys Rev E 2024; 109:025203. [PMID: 38491694 DOI: 10.1103/physreve.109.025203] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/18/2024] [Indexed: 03/18/2024]
Abstract
An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05 MJ of laser light at a wavelength of 351 nm and produced 3.1±0.16 MJ of total fusion yield, producing a target gain G=1.5±0.1 exceeding unity for the first time in a laboratory experiment [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe the experimental evidence for the increased drive on the capsule using additional laser energy and control over known degradation mechanisms, which are critical to achieving high performance. Improved fuel compression relative to previous megajoule-yield experiments is observed. Novel signatures of the ignition and burn propagation to high yield can now be studied in the laboratory for the first time.
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Affiliation(s)
- A Pak
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A B Zylstra
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - K L Baker
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - D T Casey
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - E Dewald
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - L Divol
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M Hohenberger
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J E Ralph
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - D J Schlossberg
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - R Tommasini
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - N Aybar
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - B Bachmann
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - R M Bionta
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - D Fittinghoff
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M Gatu Johnson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - H Geppert Kleinrath
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - V Geppert Kleinrath
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - K D Hahn
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M S Rubery
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J D Moody
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - L Aghaian
- General Atomics, San Diego, California 92186, USA
| | - A Allen
- General Atomics, San Diego, California 92186, USA
| | - S H Baxamusa
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - S D Bhandarkar
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J Biener
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - N W Birge
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - T Braun
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - T M Briggs
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - C Choate
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - D S Clark
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J W Crippen
- General Atomics, San Diego, California 92186, USA
| | - C Danly
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M Durocher
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - M Erickson
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | | | - M Freeman
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - M Havre
- General Atomics, San Diego, California 92186, USA
| | - S Hayes
- General Atomics, San Diego, California 92186, USA
| | - T Hilsabeck
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J P Holder
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - K D Humbird
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - O A Hurricane
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - N Izumi
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - S M Kerr
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - S F Khan
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - Y H Kim
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - C Kong
- General Atomics, San Diego, California 92186, USA
| | - J Jeet
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - B Kozioziemski
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A L Kritcher
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - K M Lamb
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - N C Lemos
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - B J MacGowan
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A J Mackinnon
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A G MacPhee
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - E V Marley
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - K Meaney
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - M Millot
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - J-M G Di Nicola
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - A Nikroo
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - R Nora
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M Ratledge
- General Atomics, San Diego, California 92186, USA
| | - J S Ross
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - S J Shin
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - V A Smalyuk
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - M Stadermann
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - S Stoupin
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - T Suratwala
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - C Trosseille
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - B Van Wonterghem
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - C R Weber
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - C Wild
- Diamond Materials GmbH, 79108 Freiburg, Germany
| | - C Wilde
- Los Alamos National Laboratory, Mail Stop F663, Los Alamos, New Mexico 87545, USA
| | - P T Wooddy
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - B N Woodworth
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
| | - C V Young
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA
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Erickson M, Han Y, Rasulev B, Kilin D. Molecular Dynamics Study of the Photodegradation of Polymeric Chains. J Phys Chem Lett 2022; 13:4374-4380. [PMID: 35544382 DOI: 10.1021/acs.jpclett.2c00802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The development of reusable polymeric materials inspires an attempt to combine renewable biomass with upcycling to form a biorenewable closed system. It has been reported that 2,5-furandicarboxylic acid (FDCA) can be recovered for recycling when incorporated as monomers into photodegradable polymeric systems. Here, we conduct density functional theory (DFT) studies with periodic boundary conditions on microscopic structures involved in the photodegradation of polymeric chains incorporating FDCA and 2-nitro-1,3-benzenedimethanol. The photodegradation process of polymeric chains is studied using time-dependent excited-state molecular dynamics (TDESMD) in vacuum and aqueous environments. Changes in the photophysical properties for reaction intermediates are characterized by ground-state observables. The distribution of reaction intermediates and products is obtained from TDESMD trajectories using cheminformatics techniques. Results show that a higher degree of polymeric chain degradation is achieved in the vacuum environment. Additionally, one finds that the FDCA molecule is recoverable in the aqueous environment, in qualitative agreement with experimental findings.
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Affiliation(s)
- Meade Erickson
- Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Yulun Han
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Bakhtiyor Rasulev
- Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Dmitri Kilin
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
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Erickson M, Truong A, Boucher K, Hyngstrom J. 522 Associations between influenza vaccine and immunotherapy outcomes in metastatic melanoma patients. J Invest Dermatol 2021. [DOI: 10.1016/j.jid.2021.02.548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Malacco VMR, Erickson M, Cardoso FF, Biese BP, Laguna JG, Donkin SS. Short communication: Effect of glucose infusion dose and stage of lactation on glucose tolerance test kinetics in lactating dairy cows. J Dairy Sci 2020; 103:7547-7554. [PMID: 32475657 DOI: 10.3168/jds.2019-17139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 02/14/2020] [Indexed: 12/26/2022]
Abstract
The objective for this study was to determine the effect of glucose dose and days following peak milk yield on plasma glucose, serum insulin, and plasma nonesterified fatty acids (NEFA) kinetics during an intravenous glucose tolerance test (IVGTT) in lactating dairy cattle. Six lactating Holstein dairy cows (3 primiparous and 3 multiparous) were assigned to 2 squares and received 0.092, 0.15, or 0.3 g of glucose/kg of body weight (BW) during an IVGTT at 74 and 221 d in milk (DIM), representing early (post-peak) lactation and mid lactation, respectively. Treatments were applied in a replicated Latin square design using contiguous 7-d periods within each stage of lactation. Milk production and dry matter intake were determined daily during the first 6 d of each period. The IVGTT was performed on d 7. For the IVGTT, cows were prepared with indwelling catheters in each jugular vein, and blood samples were collected at -15, -10, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min relative to the glucose infusion. Samples were analyzed for plasma glucose, serum insulin, and plasma NEFA concentrations. Increasing the glucose dose during the IVGTT increased plasma glucose area under the curve (AUC), decreased glucose half-life, and increased maximal plasma glucose concentrations in plasma during the IVGTT. Greater glucose dose during the IVGTT elevated serum insulin AUC and increased nadir NEFA concentrations. Maximal plasma glucose concentration during the IVGTT was lower, whereas maximum NEFA concentration, NEFA AUC, and NEFA clearance rate were greater at 74 than at 221 DIM. Only glucose half-life was responsive to stage of lactation × glucose dose effects during the IVGTT, and the decrease in glucose half-life with increasing glucose dose was greater at 74 than at 221 DIM. Glucose AUC was greater and NEFA AUC lower for cows at 74 than at 221 DIM. For the doses tested, a glucose dose greater than 0.092 g/kg of BW resulted in peak blood glucose concentration that exceeded the previously reported renal glucose excretion threshold of 8.3 mM. There is a need for accompanying data to determine if this is the case for the glucose doses evaluated in this experiment. Based on maximal peak glucose concentrations and effects on glucose half-life, we identify 0.092 g of glucose/kg of BW (0.46 g/kg of metabolic body weight) as the preferred dose for the IVGTT for cows at 74 and 221 DIM in this study.
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Affiliation(s)
- V M R Malacco
- Department of Animal Sciences, Universidade Federal de Minas Gerais, Minas Gerais, 30161-970, Brazil; Department of Animal Sciences, Purdue University, West Lafayette, IN 47906
| | - M Erickson
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47906
| | - F F Cardoso
- Department of Animal Sciences, Universidade Federal de Lavras, Minas Gerais, 37200-000, Brazil
| | - B P Biese
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47906
| | - J G Laguna
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47906
| | - S S Donkin
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47906.
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Lan N, Tan H, Erickson M, Gupta A. 275 A Novel Method for Detecting Coronary Artery Dissection Using Computed Tomography Coronary Angiography. Heart Lung Circ 2020. [DOI: 10.1016/j.hlc.2020.09.282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Erickson M, Lansford AC, Musgrave JA, Funston RN. 171 Effect of Backgrounding and Feedlot System Strategies on May-Born Steer Performance. J Anim Sci 2018. [DOI: 10.1093/jas/sky073.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- M Erickson
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
| | - A C Lansford
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
| | - J A Musgrave
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
| | - R N Funston
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
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Erickson M, Ramsay KC, Funston RN. 386 Efficacy of a Second Injection of Prostaglandin F2α in Yearling Beef Heifers Following Previous Estrus Synchronization. J Anim Sci 2018. [DOI: 10.1093/jas/sky073.383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M Erickson
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
| | | | - R N Funston
- University of Nebraska, West Central Research and Extension Center, North Platte, NE
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Steinwender C, Mont L, Duray GZ, Clementy N, Chinitz L, Sheldon T, Erickson M, Grenz NA, Amori V, Koehler J, Ritter P. 39Sensing of atrial contraction by an accelerometer within a ventricular leadless pacemaker. Europace 2018. [DOI: 10.1093/europace/euy015.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - L Mont
- Hospital Clinic de Barcelona, Barcelona, Spain
| | - G Z Duray
- Medical Centre, Hungarian Defence Forces, Budapest, Hungary
| | - N Clementy
- University Hospital of Tours, Tours, France
| | - L Chinitz
- New York University Langone Medical Center, New York, United States of America
| | - T Sheldon
- Medtronic, plc, Mounds View, Minnesota, United States of America
| | - M Erickson
- Medtronic, plc, Mounds View, Minnesota, United States of America
| | - N A Grenz
- Medtronic, plc, Mounds View, Minnesota, United States of America
| | - V Amori
- Medtronic EMEA Regional, Clinical Center, Rome, Italy
| | - J Koehler
- Medtronic, plc, Mounds View, Minnesota, United States of America
| | - P Ritter
- University Hospital of Bordeaux, Bordeaux, France
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Virag N, Erickson M, Taraborrelli P, Vetter R, Lim PB, Sutton R. 179Predicting vasovagal syncope from heart rate and blood pressure: a prospective study in 140 subjects. Europace 2017. [DOI: 10.1093/ehjci/eux136.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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McCarter S, St. Louis E, Sandness D, Arndt K, Erickson M, Tabatabai G, Boeve B, Silber M. Antidepressants increase REM sleep muscle tone in patients with and without REM sleep behavior disorder. Sleep Med 2015. [DOI: 10.1016/j.sleep.2015.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ihdayhid A, Chopra S, Erickson M. Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA): classical imaging findings on angiography and echocardiography. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Gerbaud E, Erickson M, Grenouillet-Delacre M, Beauvieux MC, Coste P, Durrieu-Jaïs C, Hilbert G, Castaing Y, Vargas F. Echocardiographic evaluation and N-terminal pro-brain natriuretic peptide measurement of patients hospitalized for heart failure during weaning from mechanical ventilation. Minerva Anestesiol 2012; 78:415-425. [PMID: 22310189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Weaning patients with heart failure who have required mechanical ventilation remains challenging. We evaluated echocardiographic indexes and N-terminal pro-brain natriuretic peptide (NT-proBNP) as markers of acute cardiac dysfunction before and after spontaneous breathing trials (SBT) in such patients to assess their ability to predict subsequent successful extubation. METHODS Forty-four patients who underwent their first SBT were prospectively included. Plasma levels of NT-proBNP and transthoracic echocardiography indices including cardiac index, E/A ratio and E/Ea ratio were recorded immediately before commencing and just before the end of SBT. RESULTS Ten patients (22.7%) failed their SBT. No significant difference was observed concerning baseline echocardiographic data and NT-proBNP level between the patients who succeeded the SBT or those that failed. Cardiac index increased significantly at end-SBT in patients who passed (3.3 [3.06-3.77] vs. 3 [2.68-3.3] L/min/m(2), P<0.001), whereas it remained unchanged in those that failed. E/Ea ratio (16.8 [8.5-27.3] vs. 10.7 [6.7-20.5], P=0.006) and NT-proBNP level (8199 [3106-10949] vs. 4200 [1855-7125] pg/mL, P=0.004) increased significantly in those who failed the SBT, in contrast to the weaning success group where they remained unchanged. CONCLUSION Neither NT-proBNP level nor the studied echocardiographic indices before SBT were able to predict SBT outcome in patients presenting with severe heart failure. Failure to increase the cardiac index and increases in both E/Ea ratio and NT-proBNP levels were seen at end-SBT in patients who failed the SBT, and may reflect failure of myocardial reserve to cope with the stress of SBT.
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Affiliation(s)
- E Gerbaud
- Soins Intensifs Cardiologiques, Plateau de Cardiologie Interventionnelle, CHU de Bordeaux, Hopital Haut-Lévêque, Pessac, France.
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Chung E, Erickson M, Torres V, Haas G, Magalski A, Adamson P, Costanzo M, Murillo J. 459 Monitoring of Respiratory Rate Derived from an Implantable Right Ventricular Pressure Sensor in Patients with Heart Failure. J Heart Lung Transplant 2012. [DOI: 10.1016/j.healun.2012.01.470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Griffis TJ, Lee X, Baker JM, Billmark K, Schultz N, Erickson M, Zhang X, Fassbinder J, Xiao W, Hu N. Oxygen isotope composition of evapotranspiration and its relation to C4photosynthetic discrimination. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jg001514] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Michalski M, Rosenfield C, Erickson M, Selle R, Bates K, Essar D, Massung R. Anaplasma phagocytophilum in central and western Wisconsin: a molecular survey. Parasitol Res 2007; 99:694-9. [PMID: 16738890 DOI: 10.1007/s00436-006-0217-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 04/16/2006] [Indexed: 10/24/2022]
Abstract
Anaplasma phagocytophilum is an obligate intracellular bacterium that is transmitted to humans through the bite of Ixodes spp. ticks, and causes a febrile disease known as human granulocytic anaplasmosis. The presence of A. phagocytophilum in Wisconsin white-tailed deer blood and in deer ticks was assessed using PCR and DNA sequencing. Sampling sites in the western part of the state (Buffalo County) and central region (Waushara, Waupaca, and Green Lake counties) were used. In Buffalo County, 5.6% of deer and 8.9% of ticks were infected. At Hartman Creek State Park (Waupaca County), 11.5% of ticks were infected, while the observed prevalence in deer from counties to the south of the park (Waushara and Green Lake) reached 19-26%. Based on 16S rRNA sequences, A. phagocytophilum strains associated and not associated with human infections were identified. Furthermore, two novel A. phagocytophilum variants were found in deer blood samples. Transmission of Lyme disease has been documented in both the Western and Central regions we sampled, and the presence of A. phagocytophilum in naturally occurring tick populations could present an additional risk of disease to humans that enter tick habitats.
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Affiliation(s)
- M Michalski
- Department of Biology and Microbiology, University of Wisconsin Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA.
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Erickson M, Rankin J, Amerena J, Brieger D, Coverdale S, Huynh L, Astley C, Chew D. Reperfusion Therapy in STEMI: ACACIA Registry Contemporary Australian Data. Heart Lung Circ 2007. [DOI: 10.1016/j.hlc.2007.06.314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Erickson M, Simillion E, Cope G, Mews G, Clugston R, Shetty S, Rankin J. Intra-Coronary Thrombectomy with the Possis AngioJet Rheolytic Catheter in ST Elevation Myocardial Infarction-a Single Centre Experience. Heart Lung Circ 2007. [DOI: 10.1016/j.hlc.2007.06.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Erickson M, Murray C. Cardiac Magnetic Resonance Imaging in the evaluation of Stress Related Cardiomyopathy. Heart Lung Circ 2007. [DOI: 10.1016/j.hlc.2007.06.098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kornysova O, Maruska A, Owens PK, Erickson M. Non-particulate (continuous bed or monolithic) acrylate-based capillary columns for reversed-phase liquid chromatography and electrochromatography. J Chromatogr A 2005; 1071:171-8. [PMID: 15865190 DOI: 10.1016/j.chroma.2004.10.078] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Three approaches are described to synthesize acrylic non-particulate beds (also called continuous beds or monoliths) in aqueous polymerization media for reversed-phase capillary liquid chromatography/electrochromatography. In the first, hexyl acrylate comonomer was dissolved together with water soluble polar comonomers using a non-ionic detergent. In the second, a new alkyl ammonium salt comonomer, (3-allylamino-2-hydroxypropyl)dodecyldimethylammonium chloride was used, which is water soluble and has detergent properties itself. The alkyl group of this comonomer provides hydrophobicity while the ionic groups generate electroosmosis in the non-particulate bed. In the third approach, the alkyl comonomer was used as a detergent to dissolve another hydrophobic comonomer in an aqueous polymerization medium. All three approaches were evaluated with respect to hydrophobicity, efficiency and electroosmotic properties of the beds. Hydrophobicity expressed as methylene group selectivity for the three types of the beds in 50% methanol mobile phase was 1.86, 1.16 and 1.78, electroosmotic mobility -5.14 x 10(-5), 6.89 x 10(-5) and 6.37 x 10(-5) cm2 V(-1) s(-1) and efficiency for the retained compound (methylparabene) 67,000, 93,000 and 110,000 plates m(-1) correspondingly. The columns were tested using pressure driven capillary chromatography and capillary electrochromatography. The influence of polymerization temperature on hydrodynamic permeability, separation impedance and inverse size exclusion porosimetry characteristics were used to evaluate the separation columns. The increase of the polymerization temperature resulted higher permeability of the bed, separation impedance and lower polymeric skeleton porosity. Further characterisation was provided by examining the separation efficiency observed for a series of benzoic acid esters and alkyl parabens.
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Affiliation(s)
- O Kornysova
- Department of Chemistry, Vytautas Magnus University, Vileikos 8, LT-44404 Kaunas, Lithuania
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Fietze I, Theres H, Melzer C, Glos M, Duru F, Lemola K, Bloch K, Erickson M, Cho Y, Markowitz T. Nächtliches Overdrive-Pacing hat keinen Einfluss auf die Schlafapnoe. Pneumologie 2004. [DOI: 10.1055/s-2004-828906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
OBJECTIVES To investigate the efficacy of botulinum toxin A in chronic low back pain and associated disabilities. METHODS Thirty-one consecutive patients with chronic low back pain who met the inclusion criteria were studied: 15 received 200 units of botulinum toxin type A, 40 units/site at five lumbar paravertebral levels on the side of maximum discomfort, and 16 received normal saline. Each patient's baseline level of pain and degree of disability was documented using the visual analogue scale (VAS) and the Oswestry Low Back Pain Questionnaire (OLBPQ). The authors reevaluated the patients at 3 and 8 weeks (visual analogue scale) and at 8 weeks (OLBPQ). RESULTS At 3 weeks, 11 of 15 patients who received botulinum toxin (73.3%) had >50% pain relief vs four of 16 (25%) in the saline group (p = 0.012). At 8 weeks, nine of 15 (60%) in the botulinum toxin group and two of 16 (12.5%) in the saline group had relief (p = 0.009). Repeat OLBPQ at 8 weeks showed improvement in 10 of 15 (66.7%) in the botulinum toxin group vs three of 16 (18.8%) in the saline group (p = 0.011). No patient experienced side effects. CONCLUSION Paravertebral administration of botulinum toxin A in patients with chronic low back pain relieved pain and improved function at 3 and 8 weeks after treatment.
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Affiliation(s)
- L Foster
- Department of Physical Medicine & Rehabilitation, Walter Reed Army Medical Center, Washington, DC, USA
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Abstract
We describe a 35-year-old woman who presented with the syndrome of painful hand-moving fingers on the right side. Eight months later, she developed similar finger movements and hand discomfort on the left side. She had a history of hand trauma and recurrent shoulder dislocation on the right side. Kinesiologic electromyography suggested a common central oscillator for finger movements in both hands. Electrophysiological assessment of spinal alpha motor neuron excitability, reciprocal inhibition, and Renshaw cell inhibition failed to show any abnormalities. Somatosensory evoked potential test showed marked attenuation of N20 potential recorded from the left somatosensory cortex; paired transcortical magnetic stimulation of the left motor cortex suggested failure of cortical facilitation. The data suggest that the central oscillator responsible for finger movements is located above the spinal cord level in this patient.
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Affiliation(s)
- B Jabbari
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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Len SV, Hung YC, Erickson M, Kim C. Ultraviolet spectrophotometric characterization and bactericidal properties of electrolyzed oxidizing water as influenced by amperage and pH. J Food Prot 2000; 63:1534-7. [PMID: 11079696 DOI: 10.4315/0362-028x-63.11.1534] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To identify the primary component responsible in electrolyzed oxidizing (EO) water for inactivation, this study determined the concentrations of hypochlorous acid (HOCl) and hypochlorite ions (OCl-) and related those concentrations to the microbicidal activity of the water. The ultraviolet absorption spectra were used to determine the concentrations of HOCl and OCl- in EO water and the chemical equilibrium of these species with change in pH and amperage. EO water generated at higher amperage contained a higher chlorine concentration. The maximum concentration of HOCl was observed around pH 4 where the maximum log reduction (2.3 log10 CFU/ml) of Bacillus cereus F4431/73 vegetative cells also occurred. The high correlation (r = 0.95) between HOCl concentrations and bactericidal effectiveness of EO water supports HOCl's role as the primary inactivation agent. Caution should be taken with standard titrimetric methods for measurement of chlorine as they cannot differentiate the levels of HOCl present in EO water of varying pHs.
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Affiliation(s)
- S V Len
- Department of Food Science and Technology, College of Agricultural and Environmental Sciences, University of Georgia, Griffin 30223-1797, USA
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Abstract
INTRODUCTION Respiratory changes accompany the cardiovascular changes during head-up, tilt test-induced vasovagal syncope. METHODS AND RESULTS Using the 45-minute 60 degrees head-up Westminster protocol, 29 patients were studied (mean age 53.9+/-20.0 years; 19 females). Two groups resulted: tilt-induced vasovagal syncope positive and negative. The cardiorespiratory parameters blood pressure (BP), heart rate (HR), tidal volume, and minute volume were measured. Comparisons of the cardiorespiratory parameters were made within the positive group and negative group, and then between the two groups. There were 14 in the positive group and 15 in the negative group. Baseline measurements were normalized to 1.0. Comparing the late tilt periods between the positive and negative groups, there were differences in BP (P < 0.002), HR (P < 0.002), tidal volume (P < 0.05), and minute volume (P < 0.002). In the positive group comparing early with late intervals: BP 1.11+/-0.09 versus 0.49+/-0.17, P < 0.0001; HR 1.18+/-0.12 versus 0.85+/-0.35, P < 0.009; tidal volume 1.39+/-0.34 versus 2.17+/-1.00, P < 0.015; and minute volume 1.24+/-0.26 versus 3.3+/-2.03, P < 0.0025. There were no comparable cardiorespiratory changes in the negative group. CONCLUSION There were significant differences in the respiratory and cardiovascular parameters measured between those who were positive and those who were negative for tilt-induced vasovagal syncope. Within the positive group, in addition to the falls in HR and BP, there were significant increases in minute volume and tidal volume during late tilt. This suggests that there may be a role for respiratory sensors in vasovagal syncope that may permit earlier and hence possibly more effective therapy for selected patients.
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Affiliation(s)
- A S Kurbaan
- Department of Cardiology, London Chest Hospital, United Kingdom.
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Zerr DM, Huang ML, Corey L, Erickson M, Parker HL, Frenkel LM. Sensitive method for detection of human herpesviruses 6 and 7 in saliva collected in field studies. J Clin Microbiol 2000; 38:1981-3. [PMID: 10790134 PMCID: PMC86642 DOI: 10.1128/jcm.38.5.1981-1983.2000] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To facilitate studies of the epidemiology and natural history of human herpesviruses 6 and 7 in infants, a practical method for collecting and quantifying the DNA of these viruses was developed. Saliva was collected using small strips of filter paper, and virus was detected using a real-time quantitative fluorescent-probe PCR assay. The sensitivity and specificity of this method even after prolonged drying of the specimens compared favorably to those of our traditional method of collecting and assaying saliva.
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Affiliation(s)
- D M Zerr
- Department of Pediatrics, University of Washington, Seattle, USA.
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Erickson M. Diversity, compassion & exceptional leadership. Attributes of the 1999 emerging leaders. Health Forum J 1999; 42:55-7. [PMID: 10539026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Flammang D, Erickson M, McCarville S, Church T, Hamani D, Donal E. Contribution of head-up tilt testing and ATP testing in assessing the mechanisms of vasovagal syndrome: preliminary results and potential therapeutic implications. Circulation 1999; 99:2427-33. [PMID: 10318665 DOI: 10.1161/01.cir.99.18.2427] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In patients with vasovagal syndrome, head-up tilt testing may reproduce symptoms generally associated with vasodepression. Recent research suggests ATP testing identifies patients with abnormal vagal cardiac inhibition. This preliminary study examined the joint contribution of both tests in identifying underlying mechanisms in the general population with vasovagal syndrome. METHODS AND RESULTS Both tests were performed in random order during 1 session and outside of predominant sympathetic periods in 72 patients hospitalized for syncope (n=56) or presyncope (n=16) for whom no cardiac or extracardiac cause was found. For passive and isoproterenol-provocative tilt testing by standard protocol, reproduction of symptoms defined a positive test. The ATP test consisted of injecting ATP 20 mg IV at bedside, continuously monitoring ECG and blood pressure; a vagal cardiac pause >10 seconds defined a positive test. For most patients (64%), >/=1 test was positive. Of the 41 patients (57%) with a positive tilt test (either passive or provoked by isoproterenol), 32% had cardiac disease; none had significant bradycardia (<50 bpm). Of the 8 patients (11%) with a positive ATP test, 62% had cardiac disease; the probability of a positive result increased with age (P=0.015). Both tests were positive in 3 patients and negative in 26 patients; the tilt and ATP test results were uncorrelated (P=0.28). CONCLUSIONS Results suggest tilt and ATP tests individually and jointly determine the mechanism of vasovagal symptoms in most patients and that vagal cardiac inhibition increases with age.
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Affiliation(s)
- D Flammang
- Angoulême General Hospital, Saint Michel, France
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Abstract
INTRODUCTION Adenosine-5'-triphosphate (ATP) provokes negative chronotropic and dromotropic vagal effects. In vasovagal syndrome, ATP test (20-mg i.v. bolus infusion) represents a promising technique for identifying patients at risk of severe cardioinhibitory response of vagal origin. The electrocardiographic and related symptom reproducibility of this descriptive test must be assessed. METHODS AND RESULTS In order to achieve this objective, ATP tests were performed twice in 80 patients (44 men, 36 women; mean age 72.3+/-12.2 years) by using the recently published test procedure and criteria of positivity. The second test was repeated shortly after the initial test (mean: 7 days) in 43 patients and long-term (mean: 3.7 years) in 37 patients. The initial ATP test provoked a cardiac pause > 10 seconds in 31 patients (39%) and a short cardiac pause (< or =10 sec) or no pause in 49 patients (61%). The electrocardiographic outcome was reproduced during the second ATP test in 36 patients (84%) of the short-term group and in 29 patients (78%) of the long-term group. Similarly, symptoms were reproduced in 38 patients (88%) of the short-term group and 29 patients (78%) of the long-term group, reflecting the severity of the electrocardiographic outcome. CONCLUSION The negative chronotropic and dromotropic vagal effect of ATP can be reproduced short term and long term in 84% and 78% of patients, respectively. Associated symptoms were related to the severity of the electrocardiographic outcome.
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Affiliation(s)
- D Flammang
- Department of Cardiology, Angoulême General Hospital, Saint Michel, France
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Rothenberg S, Erickson M, Eilert R, Fitzpatrick J, Chang F, Glancy G, Georgopoulus G, Brown C. Thoracoscopic anterior spinal procedures in children. J Pediatr Surg 1998; 33:1168-70; discussion 1170-1. [PMID: 9694116 DOI: 10.1016/s0022-3468(98)90553-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
METHODS From February 1996 through July 1997, 20 patients were determined to be appropriate for a thoracoscopic approach for the anterior portion of their spinal surgery. Ages ranged from 8 to 17 years of age and weight from 20 to 70 kg. The diagnosis included severe idiopathic and neurogenic scoliosis or kyphosis (n = 20) and congenital hemivertebra (n = 4). The procedures performed included diskectomy and anterior release from two to nine vertebral levels, hemivertebrectomy, and epiphysiodesis. Four patients also had an open lumbar exposure and all had a posterior fusion. RESULTS All procedures were completed successfully endoscopically. Surgical times for the thoracoscopic portion of the procedure averaged 106 minutes and total procedure times were comparable with the standard open technique. Three patients were extubated at the end of the procedure with the majority extubated on postoperative day 1. Average intensive care unit stay was 1.8 days, and chest tubes were removed between postoperative day 1 and 5 (average, 2.2 days). In follow-up, surgical correction was deemed to be acceptable and equivalent to open techniques in all cases. CONCLUSION This technique has proven to be safe and effective in children and appears to be associated with less pain and morbidity as evidenced by earlier extubation and chest tube removal and shorter ICU stay.
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Abstract
This study examined the potential utility of monitoring right ventricular dP/dt as a means of detecting imminent vasovagal syncope. To assess this possibility, continuous right ventricular pressure measurements were recorded in nine patients during induction of syncope by head-up tilt testing. Findings indicated that arterial pressure tended to fall prior to drop in heart rate. RV pressure exhibited a significant, but very small, fall during tilt. DP/dt max increased by 15-20% during tilt, then fell by a median of 30% from maximum value beginning about 2 minutes prior to syncope. Thus, further investigation of dP/dt as a potential marker of impending vasovagal syncope is warranted.
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Affiliation(s)
- M E Petersen
- Chelsea and Westminster Hospital, London, United Kingdom
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Affiliation(s)
- D G Benditt
- University of Minnesota Medical School, Minneapolis 55455, USA
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Abstract
A new impurity has been found in some batches of metoprolol tartrate. As the amount exceeded 0.1% it was of interest to deduce the structure. Techniques involved in solving the problem were LC, LC-MS and GC-MS. The LC systems showed that the impurity and metoprolol behaved differently to modifications of the mobile phase, indicating that there were differences in the functional groups. LC-MS was used to determine the molecular weight, which was 74 mass units higher than metoprolol. A hydrogen-deuterium shift technique using micro column LC-MS gave the information that three hydrogen atoms were bound to heteroatoms, i.e. one more than in metoprolol. This led to the conclusion that the impurity had three extra carbon and two extra oxygen atoms. It was supposedly a by-product in the synthesis. Knowledge of the synthesis steps for beta-receptor blocking drugs suggested three possible structures. Two were independently synthesized and one of these was found to be identical to the impurity.
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Affiliation(s)
- M Erickson
- Astra Hässle AB, Department of Analytical Chemistry, Mölndal, Sweden
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Lau CP, Tai YT, Lee IS, Erickson M, Yerich C. Utility of an implantable right ventricular oxygen saturation-sensing pacemaker for ambulatory cardiopulmonary monitoring. Chest 1995; 107:1089-94. [PMID: 7705121 DOI: 10.1378/chest.107.4.1089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Mixed venous oxygen saturation (SvO2) is a physiologic parameter reflecting cardiac output (CO) and tissue oxygen utilization. An implantable oxygen sensor incorporated in a right ventricular pacing lead has been developed to assess the feasibility of ambulatory monitoring of SvO2 to predict cardiorespiratory parameters. Eight patients with a mean age of 62 +/- 2 years and sinoatrial disease received an SvO2-driven dual-chamber rate-adaptive pacemaker capable of continuous SvO2 measurement. During graded maximal exercise with measurement of oxygen consumption (Vo2), arterial oxygen saturation (SaO2), and telemetered derived SvO2 data, CO was assessed using the Fick principle. The accuracy of the derived CO was compared with CO measured directly by continuous-wave Doppler assessment of the ascending aortic flow. The maximum changes in SvO2 and SaO2 during exercise were 25 +/- 5 and 3 +/- 1%, respectively. SvO2 was significantly correlated with Vo2 (r = 0.9 +/- 0.1, p < 0.001), work done (r = 0.8 +/- 0.1, p < 0.05), and minute ventilation (r = 0.9 +/- 0.1, p < 0.05). Doppler-derived CO was significantly correlated with CO estimated from SvO2 measured (r = 0.8 +/- 0.1, p < 0.05) and is expressed as 46x derived CO +300. Although continuous SvO2 sensing was originally developed to increase pacing rate during exercise, its use can be extended for monitoring cardiopulmonary performance on an ambulatory basis. This may be useful as a direct assessment of cardiopulmonary status in diseased states and also as an objective means to evaluate cardiac response to medical therapy in patients with heart failure.
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Affiliation(s)
- C P Lau
- Department of Medicine, Queen Mary Hospital, University of Hong Kong
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Lau CP, Tai YT, Leung WH, Leung SK, Li JP, Wong CK, Lee IS, Yerich C, Erickson M. Rate adaptive cardiac pacing using right ventricular venous oxygen saturation: quantification of chronotropic behavior during daily activities and maximal exercise. Pacing Clin Electrophysiol 1994; 17:2236-46. [PMID: 7885930 DOI: 10.1111/j.1540-8159.1994.tb02371.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Central venous oxygen saturation (SvO2) closely reflects cardiac output and tissue oxygen consumption. In the absence of an adequate chronotropic response during exercise, SvO2 will decrease and the extent of desaturation may be used as a parameter for rate adaptive cardiac pacing. Eight patients with sinoatrial disease received a DDDR pacemaker capable of DDDR pacing by sensing either SvO2 or piezoelectric detected body movement. Both sensors were programmed to attain a rate of about 100 beats/min during walking, and with the lower and upper rates set at 50% and 90% of age predicted maximum, respectively. Chronotropic behavior of the two sensors were compared in the DDD mode with measurement of sensor responses, during everyday activities (walking, stair climbing, postural changes, and physiological stresses) and at each quartile of workload during a continuous treadmill exercise test. During walking at 2.5 mph, both sensors showed no significant difference in delay time (both react within 15 secs) or half-time (SvO2 = 36 +/- 12 sec and activity 24 +/- 3 sec; P = NS), although SvO2 driven pacing achieved 90% target rate response slower than activity sensing (124 +/- 16 sec vs 77 +/- 10 sec; P < 0.02). SvO2 pacing was associated with a more physiological rate response during walking upslope (68 +/- 12 beats/min vs 57 +/- 10 beats/min; P < 0.05), ascending stairs (59 +/- 10 beats/min vs 31 +/- 6 beats/min; P < 0.05), and standing (34 +/- 7 beats/min vs 9 +/- 2 beats/min; P < 0.05). The SvO2 sensor significantly overpaced in the first quartile of exercise (51.8 +/- 25.6% in excess of heart rate expected from workload), but the rate was within 20% of expected for the remainder of exercise. "Underpacing" was observed with the activity sensor at the higher workload. In conclusion, the SvO2 sensor demonstrated a more physiological response to activities of daily living compared with the activity sensor. Using a quantitative method, the speed of onset of rate response of the SvO2 sensor was comparable to activity sensing, and was more proportional in rate response. Significant overpacing occurs at the beginning of exercise during SvO2 driven pacing, which may be improved with the use of a curvilinear algorithm.
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Affiliation(s)
- C P Lau
- Department of Medicine, University of Hong Kong, Queen Mary Hospital
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Abstract
The authors' objective was to review previous studies of immediate (first 30 seconds) and stabilized (30 seconds to 20 minutes) hemodynamic responses of healthy adults to the head-up posture, with particular reference to alteration of such responses in the elderly and the usefulness of such data in the diagnosis of orthostatic hypotension. The immediate response in healthy young adults is characterized by a prompt rise in heart rate, which peaks at about 8 to 15 seconds and then tapers; the arterial pressure and total vascular resistance decrease sharply at 5 to 10 seconds, followed by a rapid rebound and overshoot. Over the first 30 seconds there is a steady parallel decline of thoracic blood volume and stroke volume; there is also an initial surge of cardiac output followed by a steady decrease. During the stabilized response (30 seconds to 20 minutes), the hemodynamic variables are relatively steady, showing average increases in heart rate of about 15 to 30%, in diastolic pressure of 10 to 15%, and in total vascular resistance of 30 to 40%; during the 5th to 20th minutes there are also decreases in thoracic blood volume averaging about 25 to 30%, in cardiac output 15 to 30%, and in pulse pressure about 5 to 10%. It is evident that in normal human subjects, assumption of the upright posture results in profound hemodynamic changes, most of them occurring during the first 30 seconds. In elderly subjects (aged 60-69 years), there are, in the upright posture, lesser increments of heart rate and diastolic pressure, but no significant differences from younger age groups in the response of thoracic blood volume, cardiac output or total vascular resistance. However, beginning at about age 75, there is an increasing incidence of orthostatic hypotension, which averages about 14 to 20% at age 75 and older. The tendency toward orthostatic hypotension in the elderly is due (1) to the structural and functional changes in the circulation itself, (2) to a decline in autonomic function, and (3) to a probable functional deficiency of the skeletal muscle pump. The authors believe that closer hemodynamic monitoring of orthostatic hypotension patients would considerably increase our understanding and aid in the diagnosis of this condition.
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Affiliation(s)
- J J Smith
- Department of Physiology, Medical College of Wisconsin, Milwaukee 53226
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Erickson M. Ability of chemical measurements to differentiate oxidative stabilities of frozen minced muscle tissue from farm-raised striped bass and hybrid striped bass. Food Chem 1993. [DOI: 10.1016/0308-8146(93)90321-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Conventional Holter monitoring is of limited benefit in patients with infrequent symptoms suspected to be related to arrhythmia. A small recorder implanted subcutaneously might obviate many limitations of conventional monitoring. To determine the feasibility of obtaining adequate electrocardiographic signals from such a device, a prototype was temporarily implanted in 17 patients undergoing pacemaker implantation. The prototype contained four disc-shaped titanium electrodes, 0.21 inches in diameter embedded in epoxy. The four electrodes were in a square configuration spaced 0.72 inches center to center and were placed face down in a subcutaneous pocket in the left pectoral region. Bipolar recordings were made from a horizontal pair, a vertical pair, and both diagonal paris of electrodes (interelectrode distance 1.02 inches) and recorded on electromagnetic tape after filtering at 0.5-250 Hz. The mean peak-to-peak amplitude in each configuration was determined over a five-beat interval. Clear recordings were obtained from all 17 patients with recognizable P, QRS, and T waves. The amplitude of the signals obtained from the diagonal pairs of electrodes (175 +/- 51 and 170 +/- 54 microV) were greater than obtained from either the vertical pair (142 +/- 62 microV, P = 0.08 compared to diagonal electrodes) or the horizontal pair of electrodes (105 +/- 54 microV, P < 0.01). The maximum amplitude recorded from any configuration was 189 +/- 54 microV. In six patients the device was also tested with the electrodes face up in the subcutaneous pocket.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Leitch
- Department of Medicine, University Hospital, London, Ontario, Canada
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Erickson M. An analysis of early intervention expenditures in Massachusetts. Am J Ment Retard 1992; 96:617-29. [PMID: 1344939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Early intervention expenditure data from Massachusetts were linked to service data on a 157-member sample of Massachusetts early intervention service recipients. The findings revealed an enormous variability in the total expenditure per child estimate. Regression analyses identified specific child, family, and program characteristics that were significant predictors of the hours of service received. These results were then used to estimate expected hours of service and per child expenditures for eight subgroups. Variations in total expenditures by subgroup reflected differences in the distribution of service hours by service type. The implications of these findings for the implementation of Part H of P.L. 99-457 were discussed.
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41
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Porth CM, Erickson M. Physiology of thirst and drinking: implication for nursing practice. Heart Lung 1992; 21:273-82. [PMID: 1592619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Thirst and drinking function to maintain body water balance and are basic to survival. Thirst is often associated with a dry unpleasant-tasting mouth and the feeling of a need to obtain water; it can result from dehydration, decreased vascular volume, dry mouth, pharmacologic agents, or inappropriate activation of the thirst mechanism. Drinking involves the motor activities that culminate in ingestion of liquids. Thirst sensation and drinking are influenced by many factors, including the temperature and taste of a liquid. Thirst may be discomforting in persons with limited fluid intake, diminished in some elderly persons, and inappropriate in persons who are compulsive water drinkers. Although nurses are commonly confronted with client complaints of thirst, there has been minimal nursing research that relates to assessment of thirst and drinking behaviors, nursing diagnoses for thirst, or nursing interventions for persons with altered thirst or drinking behaviors.
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Affiliation(s)
- C M Porth
- School of Nursing, University of Wisconsin-Milwaukee 53201
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Abstract
A common procedure for assessing children's behavior is to obtain parental ratings of the child. Since the ratings obtained are a function of both parent and child, disentangling the child's phenotype from that of the rater becomes an important methodological problem. For the analysis of genetic and environmental contributions to children's behavior, solutions to this are available when multiple raters, e.g., two parents, rate multiple children, e.g., twins. This paper describes and illustrates simple LISREL models for the analysis of parental ratings of children's behavior. We show how the assumption that mothers and fathers are rating the same behavior in children can be contrasted with the weaker alternative that parents are rating correlated behaviors. Given the stronger assumption, which appears adequate for ratings of children's internalizing behavior problems, the contribution of rater bias and unreliability may be separated from the shared and nonshared environmental components of variation in a behavior genetic analysis.
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Affiliation(s)
- J K Hewitt
- Department of Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0003
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Bennett T, Sharma A, Sutton R, Camm AJ, Erickson M, Beck R. Development of a Rate Adaptive Pacemaker Based on the Maximum Rate-of-Rise of Right Ventricular Pressure (RV dP/dtmax). Pacing Clin Electro 1992; 15:219-34. [PMID: 1372421 DOI: 10.1111/j.1540-8159.1992.tb03066.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The maximum rate of rise of right ventricular pressure (RV dP/dtmax) may change in response to physiological stress and thereby provide an appropriate parameter upon which to base rate adaptive pacing. Initial feasibility testing was carried out in six patients using externally closed loop rate adaptive pacing with a pressure sensing lead (Model 6220) and an investigational VVI pulse generator (Medtronic, Model 2451). During exercise, maximum positive RV dP/dtmax increased from 223 +/- 55 to 405 +/- 181 mmHg.sec.1 (P less than 0.05). Based on these results, rate adaptive pulse generators using maximum positive RV dP/dt were implanted in 12 patients (Medtronic, Model 2503). Exercise treadmill testing in the VVI mode resulted in heart rates ranging from 69 +/- 6 beats/min at rest to 79 +/- 14 beats/min (n = 12; P greater than 0.05). In contrast, VVIR mode pacing rates ranged from 71 +/- 11 beats/min to 115 +/- 24 beats/min (n = 17; P less than 0.05). Holter recording showed heart rates ranging from 51 +/- 6 to 110 +/- 22 beats/min during activities of normal daily living (n = 9; P less than 0.05). Passive postural tilt resulted in rates of 69 +/- 8 beats/min in the supine position increasing to 74 +/- 14 beats/min with 60 degrees upright tilt (n = 16; P greater than 0.05). With up to 5-year follow-up data, there have been no late failures of pacing but one lead showed insulation failure with over- and undersensing after 4.5 years. A number of deficiencies were identified in the prototypes leading to modifications of a subsequent generation of rate responsive pacemaker based on RV dP/dtmax. These initial data demonstrate that rate adaptive pacing based on RV dP/dtmax responds in a physiological manner. This rate responsive system is of particular interest as it is based on a beat-to-beat parameter of cardiac mechanical function.
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Affiliation(s)
- T Bennett
- Sutter Memorial Hospital, Sacramento, California
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Sharma AD, Bennett TD, Erickson M, Klein GJ, Yee R, Guiraudon G. Right ventricular pressure during ventricular arrhythmias in humans: potential implications for implantable antitachycardia devices. J Am Coll Cardiol 1990; 15:648-55. [PMID: 2303634 DOI: 10.1016/0735-1097(90)90640-b] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Implantable defibrillators use algorithms based on ventricular electrographic data to detect the onset and termination of arrhythmias, but these algorithms do not always differentiate hemodynamically stable from unstable arrhythmias. Although, ideally, left ventricular function should be used to assess the hemodynamic state, right ventricular pulse pressure can be assessed in humans on a long-term basis with a transvenous lead. The potential utility of right ventricular pulse pressure to assess hemodynamic stability was studied in 22 patients with induced ventricular arrhythmias. Right ventricular pressure was measured with use of a transvenous right ventricular endocardial pacing lead with a piezoelectric bender pressure sensor 3 cm from its tip. Single ventricular premature paced beats administered in up to a bigeminal frequency did not alter the mean right ventricular pulse pressure (control 33.7 +/- 26, bigeminy 35.7 +/- 26 mm Hg). Twenty-one episodes of induced ventricular tachycardia were studied in the electrophysiology laboratory. Five seconds after tachycardia induction, hemodynamically stable ventricular tachycardia had a longer cycle length (294 +/- 41 ms) and the right ventricular pulse pressure ratio was higher (0.55 +/- 0.26) than that in unstable ventricular tachycardia (cycle length 256 +/- 55 ms, p = 0.06; pulse pressure ratio 0.26 +/- 0.09, p less than 0.05). Twenty episodes of ventricular fibrillation were induced in eight patients. One second after induction, right ventricular pulse pressure decreased from 25 +/- 5 to 6 +/- 3 mm Hg (p less than 0.05). On the first beat after defibrillation, right ventricular pulse pressure increased to 24 +/- 14 mm Hg, a level not significantly different from that before the induction of ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A D Sharma
- Mercy General Hospital, Sacramento, California
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Erickson M, Upshur CC. Caretaking burden and social support: comparison of mothers of infants with and without disabilities. Am J Ment Retard 1989; 94:250-8. [PMID: 2478171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Data concerning mothers' perceptions of child caretaking burden, fathers' participation in child caretaking, and satisfaction with social support were analyzed for a 202 member sample consisting of mothers of infants with Down syndrome, motor impairment, developmental delay, and no known disabilities. The results were contrary to some common findings from the literature. Significant differences among the four groups were found on difficulty of and time devoted to caretaking, number of tasks with which fathers helped, and satisfaction with support from family, friends, and community groups. The programmatic and policy implications of these findings were discussed.
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Affiliation(s)
- M Erickson
- Heller Graduate School, Brandeis University, Waltham, MA 02254-9110
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Chatwood S, Erickson M. A lesson in professional development. Can Nurse 1988; 84:29-30. [PMID: 2904300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Hillman LS, Chow W, Salmons SS, Weaver E, Erickson M, Hansen J. Vitamin D metabolism, mineral homeostasis, and bone mineralization in term infants fed human milk, cow milk-based formula, or soy-based formula. J Pediatr 1988; 112:864-74. [PMID: 3373390 DOI: 10.1016/s0022-3476(88)80206-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The purpose of this study was to evaluate mechanisms of mineral homeostasis and mineralization in term infants with recommended vitamin D intakes. Infants fed human milk (nine), cow milk-based formula (11), or soy-based formula (11) were studied at 2 weeks and at 2, 4, 6, 9, and 12 months of age. While receiving 400 IU of vitamin D, all infants maintained serum vitamin D concentrations higher or equal to normal adult concentrations, and serum 25-hydroxyvitamin D levels were maintained at or above normal adult levels. Serum 1,25-dihydroxyvitamin D concentrations were higher than those of adults in the formula-fed but not in the human milk-fed infants. Serum calcium and phosphorus values were similar in all groups; however, urine phosphorus excretion and urine calcium excretion were adjusted to intakes. Serum parathyroid hormone values were normal in all groups. Bone mineral content significantly increased with age similarly in all groups; however, an apparent plateau occurred at 6 months of age in all groups. Bone width steadily increased with age. Taken as a whole, these data suggest that the vitamin D-sufficient term infant fed human milk, cow milk-based formula, or the soy-based formula studied can regulate mineral metabolism within acceptable physiologic limits to attain similar levels of serum minerals and bone mineral content.
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Affiliation(s)
- L S Hillman
- Department of Child Health, University of Missouri School of Medicine, Columbia
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Erickson M, Schwarzkopf R, McKenzie R. EFFECTS OF CAFFEINE, FRUCTOSE, AND GLUCOSE INGESTION ON MUSCLE GLYCOGEN UTILIZATION DURING EXERCISE. Med Sci Sports Exerc 1986. [DOI: 10.1249/00005768-198604001-00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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50
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