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Burgmann S, Lid M, Johnsen H, Vedvik N, Haugen B, Provine J, van Helvoort A, Torgersen J. New avenues for residual stress analysis in ultrathin atomic layer deposited free-standing membranes through release of micro-cantilevers. Heliyon 2024; 10:e26420. [PMID: 38434070 PMCID: PMC10906182 DOI: 10.1016/j.heliyon.2024.e26420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 02/13/2024] [Indexed: 03/05/2024] Open
Abstract
The fabrication of thinnest, yet undeformed membrane structures with nanometer resolution is a prerequisite for a variety of Microelectromechanical systems (MEMS). However, functionally relevant thin films are susceptible to growth-generated stress. To tune the performance and reach large aspect ratios, knowledge of the intrinsic material properties is indispensable. Here, we present a new method for stress evaluation through releasing defined micro-cantilever segments by focused ion beam (FIB) milling from a predefined free-standing membrane structure. Thereby, the cantilever segment is allowed to equilibrate to a stress-released state through measurable strain in the form of a resulting radius of curvature. This radius can be back-calculated to the residual stress state. The method was tested on a 20 nm and 50 nm thick tunnel-like ALD Image 1 membrane structure, revealing a significant amount of residual stress with 866 MPa and 6104 MPa, respectively. Complementary finite element analysis to estimate the stress distribution in the structure showed a 97% and 90% agreement in out-of-plane deflection for the 20 nm and 50 nm membranes, respectively. This work reveals the possibilities of releasing entire membrane segments from thin film membranes with a significant amount of residual stress and to use the resulting bending behavior for evaluating stress and strain by measuring their deformation.
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Affiliation(s)
- S. Burgmann
- Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | - M.J. Lid
- Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | - H.J.D. Johnsen
- Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | - N.P. Vedvik
- Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | - B. Haugen
- Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | | | - A.T.J. van Helvoort
- Department of Physics, NTNU, Trondheim, Norwegian University of Science and Technology, Norway
| | - J. Torgersen
- Chair of Materials Science, Department of Materials Engineering, TUM School of Engineering and Design, Technical University of Munich, Germany
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Peron M, Bin Afif A, Dadlani AL, Berto F, Torgersen J. Improving stress corrosion cracking behavior of AZ31 alloy with conformal thin titania and zirconia coatings for biomedical applications. J Mech Behav Biomed Mater 2020; 111:104005. [PMID: 32769072 DOI: 10.1016/j.jmbbm.2020.104005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [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: 04/11/2020] [Revised: 07/19/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
Abstract
Magnesium and its alloys have been widely studied as materials for temporary implant devices. However, corrosion-assisted cracking phenomena such as stress corrosion cracking (SCC) continue to prevent their mainstream use. For the first time, we explore the SCC susceptibility of Atomic Layer Deposition (ALD) coated AZ31 alloys in Simulated Body Fluid (SBF). Conformal 100 nm coatings of titania and zirconia were deposited on standard dogbone specimens and subjected to slow strain rate tests at 3.5 10-6 s-1 and a temperature of 37 °C. Remarkably, the SCC susceptibility index IUTS was reduced by 6% and 40% and the Iε was reduced by more than 70% and 76% with a titania and zirconia coating, respectively. Potentiodynamic polarization, hydrogen evolution and fracture behavior of the samples revealed the drastic corrosion reduction to be the main reason for the susceptibility reduction. We discuss the observed SCC behavior of our samples in light of the coatings' electrochemical activities, wettabilities, surface integrities and mechanical properties. This straightforward conformal surface treatment can be useful as a workaround for one of the major bottlenecks of biomedical Mg based implants and hence provides a possible pathway for making them more commonplace in the field.
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Affiliation(s)
- M Peron
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway.
| | - A Bin Afif
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
| | - A L Dadlani
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
| | - F Berto
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
| | - J Torgersen
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
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Peron M, Bertolini R, Ghiotti A, Torgersen J, Bruschi S, Berto F. Enhancement of stress corrosion cracking of AZ31 magnesium alloy in simulated body fluid thanks to cryogenic machining. J Mech Behav Biomed Mater 2019; 101:103429. [PMID: 31522123 DOI: 10.1016/j.jmbbm.2019.103429] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [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: 07/04/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 11/25/2022]
Abstract
Magnesium and its alloys have recently attracted great attention as potential materials for the manufacture of biodegradable implants. Unfortunately, their inadequate resistance to the simultaneous action of corrosion and mechanical stresses in the human body have hampered their use as implant materials. This work aims at evaluating the Stress Corrosion Cracking (SCC) susceptibility of the AZ31 Mg alloy after being machined under cryogenic cooling. The SCC behaviour was evaluated by means of Slow Strain Rate Tests (SSRTs) in Simulated Body Fluid (SBF) at 37 °C. Prior to testing, a full characterization of the machined surface integrity, including microstructural observations, residual stress, nano-hardness measurements and surface texture analysis was carried out together with the assessment of the corrosion properties through potentiodynamic polarization curves. In addition, the morphology of the fracture surfaces after SSRTs was analysed by means of 3D optical profiler and Scanning Electron Microscopy (SEM). The improved corrosion resistance due to the increased extension of the nano-surface layer and to the compressive residual stresses represents the reason of the reduced SCC susceptibility of cryogenically machined AZ31 samples as compared to dry machined ones.
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Affiliation(s)
- M Peron
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway.
| | - R Bertolini
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131, Padova, Italy
| | - A Ghiotti
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131, Padova, Italy
| | - J Torgersen
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
| | - S Bruschi
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131, Padova, Italy
| | - F Berto
- Department of Industrial and Mechanical Engineering, Norwegian University of Science and Technology, Richard Birkelands vei 2b, 7034, Trondheim, Norway
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Torgersen J. Anomalies of the Spine in Anomalies of Viscera and Constitution: A Radiological Contribution to the Physiology of Development of Man and to the Understanding of the Bearing of the Anomalies of the Spine on Pathology. Acta Radiol 2013. [DOI: 10.1177/028418514802900225] [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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Torgersen J. The Developmental Anatomy of the Pyloric Canal and the Etiology of Infantile Pyloric Stenosis. Acta Radiol 2013. [DOI: 10.1177/028418514903200508] [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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Torgersen J. The Frontal Sinuses in Bronchiectasis: A Study on the Morphological Basis of Lung Disease. Acta Radiol 2013. [DOI: 10.1177/028418514903200211] [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: 11/16/2022]
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Torgersen J. Localization of Gastritis and Gastric Cancer, Especially in Cases of Pernicious Anemia. Acta Radiol 2013. [DOI: 10.1177/028418514402500544] [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: 11/15/2022]
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Torgersen J. Gastric Carcinoma with Special Reference to the Sex Ratio, Age and Situation and to the Anatomy of the Stomach. Acta Radiol 2013. [DOI: 10.1177/028418515304000502] [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: 11/15/2022]
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Torgersen J. Asymmetry and Skeletal Maturation. Acta Radiol 2013. [DOI: 10.1177/028418515103600610] [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: 11/15/2022]
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Torgersen J. Hereditary Factors in the Sutural Pattern of the Skull. Acta Radiol 2013. [DOI: 10.1177/028418515103600504] [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: 11/15/2022]
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Torgersen J. The Developmental Anatomy of the Heart and the Etiology of Congenital Heart Disease. Acta Radiol 2013. [DOI: 10.1177/028418515003300204] [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: 11/16/2022]
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Torgersen J. A Roentgenological Study of the Metopic Suture. Acta Radiol 2013. [DOI: 10.1177/028418515003300101] [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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Torgersen J, Strand K, Bjelland TW, Klepstad P, Kvåle R, Søreide E, Wentzel-Larsen T, Flaatten H. Cognitive dysfunction and health-related quality of life after a cardiac arrest and therapeutic hypothermia. Acta Anaesthesiol Scand 2010; 54:721-8. [PMID: 20236101 DOI: 10.1111/j.1399-6576.2010.02219.x] [Citation(s) in RCA: 66] [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: 11/29/2022]
Abstract
BACKGROUND Evidence-based treatment protocols including therapeutic hypothermia have increased hospital survival to over 50% in unconscious out-of-hospital cardiac arrest survivors. In this study we estimated the incidence of cognitive dysfunctions in a group of cardiac arrest survivors with a high functional outcome treated with therapeutic hypothermia. Secondarily, we assessed the cardiac arrest group's level of cognitive performance in each tested cognitive domain and investigated the relationship between cognitive function and age, time since cardiac arrest and health-related quality of life (HRQOL). METHODS We included 26 patients 13-28 months after a cardiac arrest. All patients were scored using the Cerebral Performance Category scale (CPC) and Mini-Mental State Examination (MMSE). Twenty-five of the patients were tested for cognitive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB). These patients were tested using four cognitive tests: Motor Screening Test, Delayed Matching to Sample, Stockings of Cambridge and Paired Associate Learning from CANTAB. All patients filled in the Short Form-36 for the assessment of HRQOL. RESULTS Thirteen of 25 (52%) patients were classified as having a cognitive dysfunction. Compared with the reference population, there was no difference in the performance in motor function and delayed memory but there were significant differences in executive function and episodic memory. We found no associations between cognitive function and age, time since cardiac arrest or HRQOL. CONCLUSION Half of the patients had a cognitive dysfunction with reduced performance on executive function and episodic memory, indicating frontal and temporal lobe affection, respectively. Reduced performance did not affect HRQOL.
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Affiliation(s)
- J Torgersen
- Department of Anaesthesiology and Intensive Care Medicine, Haukeland University Hospital, Bergen, Norway.
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Torgersen J. [John Locke the doctor, and the ideas of democracy]. Samtiden 2001; 79:29-43. [PMID: 11635911] [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: 02/22/2023]
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Torgersen J, Collas P, Aleström P. Gene-Gun-Mediated Transfer of Reporter Genes to Somatic Zebrafish (Danio rerio) Tissues. Mar Biotechnol (NY) 2000; 2:293-300. [PMID: 10852809 DOI: 10.1007/s101260000002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We describe the use of gene-gun-mediated transfer of luciferase and green fluorescent protein (GFP) reporter genes in zebrafish (Danio rerio). Optimization of DNA transfer parameters indicated highest overall luciferase expression in epidermis and dermis using 1-μm microcarriers and 1 μg of pCMVL plasmid DNA at a delivery pressure of 200 psi. Time course studies revealed luciferase activity peaking at 18 hours and decreasing to 30% of the maximum at day 8 after DNA transfer. Onset of reporter gene (GFP) expression was detected at 13 minutes after DNA delivery, and by 65 minutes approximately 100% of the cells in the target area exhibited GFP expression. No germline association or integration events were detected in a screen of approximately 250,000 zebrafish sperm cells by fluorescence in situ hybridization at 15 or 30 days after delivery of 1 μg of pCMVL DNA, suggesting incidental male germline integration should not be considered as a risk factor when using the biolistic DNA delivery parameters and target tissues described.
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Affiliation(s)
- J Torgersen
- Department of Biochemistry, Physiology and Nutrition, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., N-0033 Oslo, Norway, NO
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Smith RE, Torgersen J, Long PH, Maurer JK. Lethality and bone alterations in chicken embryos and newly hatched chickens given bone-active agents. Am J Vet Res 1988; 49:1376-81. [PMID: 3263067] [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: 01/05/2023]
Abstract
Studies were undertaken to assess the chicken embryo and newly hatched chicken as models for studying the effects of bone-active agents. Initially, 1,25-dihydroxycholecaliferol (1,25[OH]2D3), sodium fluoride (NaF), parathyroid extract, epidermal growth factor, and prostaglandin E2, were tested for lethality over a broad dose range. One or 3 injections of 1,25(OH)2D3 into the yolk sac of chicken embryos resulted in death of embryos given greater than or equal to 0.1 ng/injection, whereas 0.01 ng was tolerated by the embryos. Administering 1,25(OH)2D3 intraperitoneally to newly hatched chickens as a single injection or weekly for 3 weeks resulted in no deaths at doses up to 50 ng. One or 3 IV injections of 800 micrograms of NaF were lethal to embryos, whereas injections of less than or equal to 400 micrograms were tolerated by the embryo. Giving chickens feed and water containing 2.4 g of NaF/kg was lethal, but no deaths occurred when chickens were given feed containing less than or equal to 1.2 g of NaF/kg. Mortality associated with the administration of epidermal growth factor to embryos was inconsistent, in that death occurred in embryos given a single injection of greater than or equal to 250 ng, but no deaths occurred in embryos given 3 injections at similar doses. Parathyroid extract and prostaglandin E2 were not lethal when administered to embryos and chickens in a single-injection or multiple-injection regimen. Overall, lethality in chicken embryos given a particular agent reflected the dose of bone-active agent injected, rather than the number of injections. Three of the bone-active agents were selected to characterize their microscopic bone effects in chicken embryos and chickens.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R E Smith
- Department of Microbiology, Colorado State University, Fort Collins 80523
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Torgersen J. [Orthodontic treatment and craniometry]. Nor Tannlaegeforen Tid 1976; 86:298-301. [PMID: 1065849] [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: 12/25/2022]
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Torgersen J. [Fine arts and neurology]. Tidsskr Nor Laegeforen 1975; 95:981-6. [PMID: 1096356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Torgersen J. The doctor, humanist and citizen. Tidsskr Nor Laegeforen 1970; 90:Suppl:1158-60. [PMID: 5450056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Torgersen J. [Pre- and postgraduate medical education]. Tidsskr Nor Laegeforen 1969; 89:1867-8. [PMID: 4914305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Torgersen J. [The lower urinary tract and the male genital organs. On problems in Norwegian works]. Tidsskr Nor Laegeforen 1968; 88:465-9. [PMID: 5691334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Torgersen J. [The kidney and the upper urinary tract. Between two doctoral dissertations, 1902 and 1962]. Tidsskr Nor Laegeforen 1968; 88:461-5. [PMID: 5669249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Torgersen J. [Heredity in medical research and practice]. Tidsskr Nor Laegeforen 1967; 87:524-5. [PMID: 6046750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Torgersen J. [The general practitioner (Otto Lund)]. Tidsskr Nor Laegeforen 1966; 86:1023-31. [PMID: 5338598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Torgersen J. [A general practitioner (Otto Lund)]. Tidsskr Nor Laegeforen 1966; 86:767-73 passim. [PMID: 5330500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Torgersen J. [The study of medicine; selection, plan and goals]. Tidsskr Nor Laegeforen 1966; 86:49-50. [PMID: 5912466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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