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Pedersen MRV, Precht H, Jensen J, Mussmann B, Abdi AJ, Hansen PL, Holm S, Mørup SD, Brage K. Radiographers use of social media - SoMe in a Nordic perspective. Radiography (Lond) 2024; 30:651-658. [PMID: 38341986 DOI: 10.1016/j.radi.2024.01.015] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/16/2024] [Accepted: 01/22/2024] [Indexed: 02/13/2024]
Abstract
INTRODUCTION Social media (SoMe) is widely used as a communication platform in everyday life. Also, healthcare professionals have embraced SoMe as a communication tool for both peers and patients. It is becoming an interactive tool for discussing professionals' issues and a place where learning and education occur. This study explores the specific patterns of SoMe use for radiographers' in the Nordic countries. The aim of this survey was to investigate radiographers use of social platforms in a professional setting. METHODS A 29-item survey was prepared, and pilot-tested. The survey was produced in Danish a language that all Nordic countries master. In general, most Nordic languages are very similar. The survey was distributed by online platforms such as Facebook, LinkedIn, Twitter/X, and also distributed by newsletters by the Norwegian and Danish national radiographers societies. All data was collected anonymously. An Ethical Research approval was obtained from the University of Southern Denmark. RESULTS A total of 242 respondents completed the survey (Denmark n = 183, Norway n = 48, Sweden n = 8, and n = 3 from other Scandinavian countries). The respondents included 186 females, 52 males and four were undisclosed. On average, the respondents spent approximately 2 h and 23 min daily on SoMe, with 27 min specifically dedicated to content relevant to radiographers. Facebook was the preferred platform with 93 % (n = 226). A total of 5.4 % (n = 13) respondents had experienced contact from patients and/or next of kin, while 92 % (n = 222) reported no such interactions and 2.9 % (n = 7) were undisclosed. A total of 52.8 % (n = 128) used SoMe in relation to courses, conferences, or online meetings. This shows that time spent on content relevant to radiographers imply that SoMe can be a relevant tool for reaching radiographers. CONCLUSION The survey demonstrates radiographers' use of SoMe for personal and professional interest, with Facebook as the preferred social media platform. SoMe were mostly used during courses, conferences, or online meetings with half of the respondent reported using SoMe platforms during working hours. These results underscore the untapped potential of SoMe in professional healthcare settings. Additionally, the study offers insight into current practices, facilitating comparisons to identify trends in SoMe usage within the radiographer community. IMPLICATIONS FOR PRACTICE The findings advocate for the strategic use of SoMe by radiographers', emphasizing professional networking and knowledge sharing. However, clear guidelines are necessary to ensure patient confidentiality and data security in these digital interactions.
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Affiliation(s)
- M R V Pedersen
- Department of Radiology, University Hospital of Southern Denmark, Vejle, Denmark; Department of Radiology, University Hospital of Southern Denmark, Kolding, Denmark; Department of Regional Health Sciences, University of Southern Denmark, Denmark.
| | - H Precht
- Department of Radiology, University Hospital of Southern Denmark, Kolding, Denmark; Department of Regional Health Sciences, University of Southern Denmark, Denmark; Health Sciences Research Centre, UCL University College, Odense, Denmark; Education of Radiography, UCL University College, Odense, Denmark
| | - J Jensen
- Research and Innovation Unit of Radiology, University Hospital, Odense, Denmark; Department of Radiology, Odense University Hospital, Odense, Denmark
| | - B Mussmann
- Research and Innovation Unit of Radiology, University Hospital, Odense, Denmark; Department of Radiology, Odense University Hospital, Odense, Denmark
| | - A J Abdi
- Research and Innovation Unit of Radiology, University Hospital, Odense, Denmark; Department of Radiology, Odense University Hospital, Odense, Denmark; Department of Clinical Engineering, Region of Southern Denmark, Denmark
| | - P L Hansen
- Health Sciences Research Centre, UCL University College, Odense, Denmark
| | - S Holm
- Health Sciences Research Centre, UCL University College, Odense, Denmark; Education of Radiography, UCL University College, Odense, Denmark
| | - S D Mørup
- Department of Radiology, University Hospital of Southern Denmark, Vejle, Denmark
| | - K Brage
- Health Sciences Research Centre, UCL University College, Odense, Denmark; Education of Radiography, UCL University College, Odense, Denmark
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Pedersen MT, Vilgis TA, Brewer JR, Hansen PL, Clausen MP. Structural characterization of solvent-based food preparation of jellyfish. Soft Matter 2024; 20:495-510. [PMID: 38088053 DOI: 10.1039/d3sm00620d] [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] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Jellyfish as a potential sustainable food material has recently gained increasing interest. However, with their soft gel-like texture and easy spoilage, it remains challenging to achieve desirable edible structures from jellyfish. The culinary preparation of jellyfish is a complex process and extends beyond conventional cooking methods. In this study, we investigate the transformation of jellyfish into crispy-like structures by manipulating their microstructural and mechanical properties through a solvent-based preparation. The study focuses on the use of "poor solvents", namely ethanol and acetone, and employs rheology measurements and quantitative microscopy techniques to analyze the effects of these solvents on the mechanical properties and microstructure of jellyfish. Our findings reveal that both ethanol and acetone lead to a significant increase in jellyfish hardness and deswelling. Notably, a micro-scale network is formed within the jellyfish matrix, and this network is then mechanically reinforced before a crispy-like texture can be obtained. Our study points to solvent polarity as also being a crucial factor for creating these effects and determines an upper polarity limit in the range of 12.2-12.9 MPa1/2 for added solvents, corresponding to approximately 60% of added ethanol or 70% of added acetone. Our study highlights that solvent-based preparation serves as a "reverse cooking" technique, where mechanical modification rather than traditional softening mechanisms are employed to stabilize and strengthen the microstructures and fibers of jellyfish. By elucidating the underlying mechanisms of solvent-induced stabilization, our findings may facilitate the development of innovative and sustainable culinary practices, paving the way for broader applications of jellyfish and other soft edible materials in the gastronomic landscape.
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Affiliation(s)
- Mie T Pedersen
- SDU Biotechnology, Department of Green Technology, University of Southern Denmark, Campusvej 55, DK-5230, Denmark.
| | | | - Jonathan R Brewer
- Department of Molecular Biology and Biochemistry & Danish Molecular Biomedical Imaging Center (DaMBIC), University of Southern Denmark, Denmark
| | - Per L Hansen
- Department of Mechanical and Production Engineering, Aarhus University, Aarhus, Denmark
| | - Mathias P Clausen
- SDU Biotechnology, Department of Green Technology, University of Southern Denmark, Campusvej 55, DK-5230, Denmark.
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Pedersen MT, Christensen M, Duelund L, Hansen PL, Brewer JR, Clausen MP. The Microscopic Structure of Crunchy and Crispy Jellyfish. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.2939] [Citation(s) in RCA: 2] [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: 10/18/2022] Open
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Affiliation(s)
- L H Light
- Clinical Research Centre, Harrow, Middlesex
| | - G Cross
- Clinical Research Centre, Harrow, Middlesex
| | - P L Hansen
- Clinical Research Centre, Harrow, Middlesex
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Rosholm KR, Arouri A, Hansen PL, González-Pérez A, Mouritsen OG. Characterization of fluorinated catansomes: a promising vector in drug-delivery. Langmuir 2012; 28:2773-2781. [PMID: 22149538 DOI: 10.1021/la2039834] [Citation(s) in RCA: 12] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Catansomes, which are vesicles prepared from mixtures of oppositely charged surfactants, have been suggested as effective alternatives to phospholipid vesicles, i.e., liposomes, in applications such as drug-delivery. This is mainly due to their enhanced chemical and physical stability as well as to their relatively easy preparation, which is an advantage for large-scale productions. In this study we have investigated catansomes prepared from a perfluorinated anionic surfactant (sodium perfluorooctanoate) premixed with a hydrogenated cationic surfactant (dodecyltrimethylammonium bromide or 1-dodecylpyridinium chloride). The aim was to gain insights into the physicochemical properties of these systems, such as size, stability, surface charge, and membrane morphology, which are essential for their use in drug-delivery applications. The catansomes were mostly unilamellar and 100-200 nm in size, and were stable for more than five months at room temperature. After loading the catansomes with the fluorescent marker calcein, they were found to exhibit an appreciable encapsulation efficiency and a low calcein leakage over time. The addition of fatty acids to calcein-loaded catansomes considerably promoted the release of calcein, and the rate and efficiency of calcein release were found to be proportional to the fatty acid concentration and chain length. Our results prove the feasibility of utilizing catansomes as drug-delivery vehicles as well as provide a means to efficiently release the encapsulated load.
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Affiliation(s)
- Kadla R Rosholm
- BioNano & NanoMedicine, Center of Nano-Science, University of Copenhagen, Universitetsparken 5, DK-2100 København Ø, Denmark
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Cohen JA, Podgornik R, Hansen PL, Parsegian VA. A phenomenological one-parameter equation of state for osmotic pressures of PEG and other neutral flexible polymers in good solvents. J Phys Chem B 2009; 113:3709-14. [PMID: 19265418 DOI: 10.1021/jp806893a] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a phenomenological one-parameter scaling equation of state that accurately represents osmotic pressures of neutral flexible polymers in good solvents from the dilute through the semidilute regime. The equation comprises a sum of scaled van't Hoff and des Cloizeaux terms including a fitted parameter alpha, the "crossover index", which encapsulates all chemical specificity and determines the relevant prefactors. Strikingly different values of alpha are found for the two very different systems poly(ethyleneglycol)/water (PEG) and poly(alpha-methylstyrene)/toluene (PAMS). Alpha-dependent rescaling collapses both data sets to a simple one-parameter scaling function. The fact that the anomalous system PEG/water and the canonical system PAMS/toluene can both be described by the same equation of state attests to the robustness of the polymer-scaling concepts introduced by de Gennes.
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Affiliation(s)
- J A Cohen
- Laboratory of Physical and Structural Biology, PPB, NICHD, NIH, Bethesda, Maryland 20892-0924, USA.
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Thormann E, Simonsen AC, Hansen PL, Mouritsen OG. Force trace hysteresis and temperature dependence of bridging nanobubble induced forces between hydrophobic surfaces. ACS Nano 2008; 2:1817-24. [PMID: 19206420 DOI: 10.1021/nn800218s] [Citation(s) in RCA: 14] [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: 05/12/2023]
Abstract
An atomic force microscope and the colloidal probe technique are used to probe the interaction between a hydrophobic particle and a hydrophobic surface in water. The characteristics of the observed force curves strongly suggest that a gas bubble is formed when the particle is moved toward the surface and that the bubble ruptures when the particle subsequently is retracted from the surface. We demonstrate that this type of interaction is not unique for hydrophobic surfaces in water since the interaction between hydrophilic surfaces in air provides very similar force curves. However, the interaction between hydrophobic surfaces vanish if water is replaced by an organic solvent with low polarity. The bridging bubble model is employed to explain the hysteresis observed between approach and retraction force traces and experimental conditions where the hysteresis can be almost eliminated are identified. Finally, it is demonstrated that the hydrophobic interaction is strongly temperature dependent and this dependence can be attributed mainly to the decreasing solubility of air in water with increasing temperature.
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Affiliation(s)
- Esben Thormann
- MEMPHYS, Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
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Thormann E, Simonsen AC, Hansen PL, Mouritsen OG. Interactions between a polystyrene particle and hydrophilic and hydrophobic surfaces in aqueous solutions. Langmuir 2008; 24:7278-84. [PMID: 18553951 DOI: 10.1021/la8005162] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The interaction between a colloidal polystyrene particle mounted on an AFM cantilever and a hydrophilic and a hydrophobic surface in aqueous solution is investigated. Despite the apparent simplicity of these two types of systems a variety of different types of interactions are observed. The system containing the polystyrene particle and a hydrophilic surface shows DLVO-like interactions characteristic of forces between charged surfaces. However, when the surface is hydrophobized the interaction changes dramatically and shows evidence of a bridging air bubble being formed between the particle and the surface. For both sets of systems, plateaus of constant force in the force curves are obtained when the particle is retracted from the surface after being in contact. These events are interpreted as a number of individual polystyrene molecules that are bridging the polystyrene particle and the surface. The plateaus of constant force are expected for pulling a hydrophobic polymer in a bad (hydrophilic) solvent. The plateau heights are found to be of uniform spacing and independent of the type of surface, which suggests a model by which collapsed polymers are extended into the aqueous medium. This model is supported by a full stretching curve showing also the backbone elasticity and a stretching curve obtained in pentanol, where the plateau changes to a nonlinear force response, which is typical for a polymer in a good or neutral solvent. We suggest that these polymer bridges are important in particular for the interaction between polystyrene and the hydrophilic surface, where they to some extent counteract the long-range electrostatic repulsion.
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Affiliation(s)
- Esben Thormann
- MEMPHYS, Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
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Thormann E, Dreyer JK, Simonsen AC, Hansen PL, Hansen S, Holmskov U, Mouritsen OG. Dynamic strength of the interaction between lung surfactant protein D (SP-D) and saccharide ligands. Biochemistry 2007; 46:12231-7. [PMID: 17915943 DOI: 10.1021/bi700823k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to investigate the dynamic strength of the interaction between lung surfactant protein D (SP-D) and different sugars, maltose, mannose, glucose, and galactose, we have used an atomic force microscope to monitor the interaction on a single molecule scale. The experiment is performed by measuring the rupture force when the SP-D-sugar bond is subjected to a continuously increasing force. Under these dynamic conditions, SP-D binds strongest to d-mannose and weakest to maltose and d-galactose. These results differ from equilibrium measurements wherein SP-D exhibits preference for maltose. On the basis of this finding, we propose that the binding of the disaccharide maltose to SP-D, which is energetically stronger than the binding of any of the monosacchrides, alters the structure of the binding site in a way that lowers the dynamic strength of the bond. We conclude that determining the strength of a protein-ligand bond under dynamic stress using an atomic force microscope is possibly more relevant for mimicking the actual nonequilibrium physiological situation in the lungs.
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Affiliation(s)
- Esben Thormann
- MEMPHYS, Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
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Abstract
We present a general and systematic theory of non-equilibrium dynamics of multi-component fluid membranes, in general, and membranes containing transmembrane proteins, in particular. Developed based on a minimal number of principles of statistical physics and designed to be a meso/macroscopic-scale effective description, the theory is formulated in terms of a set of equations of hydrodynamics and linear constitutive relations. As a particular emphasis of the theory, the equations and the constitutive relations address both the thermodynamic and the hydrodynamic consequences of the unconventional material characteristics of lipid-protein membranes and contain proposals as well as predictions which have not yet been made in already existing work on membrane hydrodynamics and which may have experimental relevance. The framework structure of the theory makes possible its applications to a range of non-equilibrium phenomena in a range of membrane systems, as discussions in the paper of a few limit cases demonstrate.
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Affiliation(s)
- M A Lomholt
- The MEMPHYS Center for Biomembrane Physics, Physics Department, University of Southern Denmark, DK-5230 Odense M, Denmark.
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López-Cartes C, Bernal S, Calvino JJ, Cauqui MA, Blanco G, Pérez-Omil JA, Pintado JM, Helveg S, Hansen PL. In situ transmission electron microscopy investigation of Ce(IV) and Pr(IV) reducibility in a Rh (1%)/Ce0.8Pr0.2O(2-x) catalyst. Chem Commun (Camb) 2003:644-5. [PMID: 12669866 DOI: 10.1039/b211786j] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In-situ Atomic Resolution Transmission Electron Microscopy studies carried out on a Rh/Ce0.8Pr0.2O(2-x) catalyst, under hydrogen in the temperature range 298-1223 K, show the occurrence of consecutive reduction of Pr4+ and Ce4+ ions, and the formation of an oxygen-deficient Ln16O30 (Ln: Ce, Pr) ordered phase.
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Affiliation(s)
- C López-Cartes
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cádiz, Apdo 40 Puerto Real, 11510-Cádiz, Spain
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Hansen TW, Wagner JB, Hansen PL, Dahl S, Topsøe H, Jacobsen CJ. Atomic-resolution in situ transmission electron microscopy of a promoter of a heterogeneous catalyst. Science 2001; 294:1508-10. [PMID: 11711670 DOI: 10.1126/science.1064399] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Insight into the location, state, and function of a promoter in heterogeneous catalysis was obtained through atomic-resolution in situ transmission electron microscopy. In the most active ruthenium catalyst for ammonia synthesis known so far, the barium promoter is shown to be located in two different phases in the catalyst. The increased activity is suggested to be related to a two-dimensional barium-oxygen overlayer on the ruthenium crystals. The possibility for conducting such studies for other reactions could add substantially to our current understanding of heterogeneous catalysis. Heterogeneous catalysis plays an increasingly important role in environmental protection processes, in fuel upgrading, and in providing the majority of the chemical building blocks required by contemporary society. Most heterogeneous catalysts of industrial importance are multicomponent materials that are designed by trial-and-error experimentation. Application of even the most sophisticated physical-chemical characterization techniques is usually not sufficient to obtain a complete understanding of the structure of the active site, the reaction mechanism and kinetics, the structural dynamics, and the specific roles of all catalyst components.
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Affiliation(s)
- T W Hansen
- Haldor Topsøe A/S, Nymøllevej 55, DK-2800 Lyngby, Denmark
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Hansen PL, Podgornik R, Parsegian VA. Osmotic properties of DNA: critical evaluation of counterion condensation theory. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:021907. [PMID: 11497620 DOI: 10.1103/physreve.64.021907] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2001] [Revised: 04/16/2001] [Indexed: 05/23/2023]
Abstract
The osmotic coefficient of B-DNA in water may, in dilute solutions, deviate by as much as 100% from predictions based on a simple line-charge "counterion condensation" theory. In contrast, a cell model description of the ionic atmosphere near a cylindrical polyelectrolyte predicts osmotic properties that are in surprisingly good harmony with all available experimental findings over a wide range of DNA concentrations. We argue that the neglect of molecular features, such as finite radius, makes line-charge condensation theory inapplicable at all but impractically low polyelectrolyte concentrations.
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Affiliation(s)
- P L Hansen
- Laboratory of Physical and Structural Biology National Institute of Child Health and Human Development National Institutes of Health, Bethesda, Maryland 20892-5626, USA
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Hansen PL, Svensek D, Adrian Parsegian V, Podgornik R. Buckling, fluctuations, and collapse in semiflexible polyelectrolytes. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1999; 60:1956-66. [PMID: 11969988 DOI: 10.1103/physreve.60.1956] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/1999] [Indexed: 04/18/2023]
Abstract
We present a systematic statistical mechanical analysis of the conformational properties of a stiff polyelectrolyte chain with intrachain attractions that are due to counterion correlations. We show that the mean-field solution corresponds to an Euler-like buckling instability. The effect of the conformational fluctuations on the buckling instability is investigated, first, qualitatively, within the harmonic ("semiclassical") theory, then, systematically, within a 1/d expansion, where d denotes the dimension of embedding space. Within the "semiclassical" approximation, we predict that the effect of fluctuations is to renormalize the effective persistence length to smaller values, but not to change the nature of the mean-field (i.e., buckling) behavior. Based on the 1/d expansion we are, however, led to conclude that thermal fluctuations are responsible for a change of the buckling behavior which is turned into a polymer collapse. A phase diagram is constructed in which a sequence of collapse transitions terminates at a buckling instability that occurs at a place that varies with the magnitude of the bare persistence length of the polymer chain, as well as with the strength and range of the attractive potential.
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Affiliation(s)
- P L Hansen
- Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, California 93106-4030, USA
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Pedersen C, Hansen PL, Buchhave P, Skettrup T. Single-frequency diode-pumped Nd:YAG prism laser with use of a composite laser crystal. Appl Opt 1997; 36:6780-6787. [PMID: 18259544 DOI: 10.1364/ao.36.006780] [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] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A compact, stable, diode-pumped Nd:YAG laser suitable for high-power single-frequency operation is investigated theoretically as well as experimentally. Residual spatial hole burning has been eliminated with a unidirectional ring-laser design with a specially designed intracavity prism and a composite YAG laser crystal. A detailed Jones matrix analysis is performed, leading to design criteria for high loss difference and high-frequency stability.
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Affiliation(s)
- C Pedersen
- Department of Physics, Technical University of Denmark, Building 309, DK-2800 Lyngby, Denmark
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Abstract
The increase in the circulating signal and idler fields that occurs in a high- Q doubly resonant optical parametric oscillator (OPO) as it approaches resonance results in a small increase in the crystal temperature owing to absorption of the generated fields. The temperature change affects the refractive index of the crystal and alters the optical path length of the cavity. This effect may lead to self-frequency locking of the OPO to a specific resonance of the signal and idler fields, and it also results in peculiarities in the transient response of the system as it is scanned through resonance. We show that the experimentally observed effects are consistent with the results of a numerical model of the OPO.
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Pedersen C, Hansen PL, Skettrup T, Buchhave P. Diode-pumped single-frequency Nd:YVO(4) laser with a set of coupled resonators. Opt Lett 1995; 20:1389-1391. [PMID: 19862024 DOI: 10.1364/ol.20.001389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
350 mW of single-frequency power from a diode-pumped solid-state Nd:YVO(4) laser has been obtained from a coupled resonator design without any intracavity elements. Single-frequency operation was obtained by use of a very short laser rod and a coupled resonator design. The two coupled resonators were formed by the two faces of a very short Nd:YVO(4) laser crystal and an output coupling mirror. The interaction of the two coupled cavities caused a modification of the eigenmodes supporting laser action in a single longitudinal mode. This design, which is extremely simple, represents a cost-eff icient way of obtaining single-frequency output.
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McGibbon AJ, Brown LM, Bleloch AL, Browning ND, Aires FC, Fallon PJ, Gaskell PH, Gilkes KW, Hansen PL, Howie A. Microscopy in solid state science. Microsc Res Tech 1993; 24:299-315. [PMID: 8390313 DOI: 10.1002/jemt.1070240404] [Citation(s) in RCA: 3] [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: 01/30/2023]
Abstract
The Microstructural Physics group at the Cavendish Laboratory is actively involved in a considerable number of research projects which cover a broad range of materials science. In this paper, we describe briefly several such projects, with particular emphasis given to the application of parallel-detection electron energy loss spectroscopy (PEELS) on a scanning transmission electron microscope (STEM) to the analysis of materials such as stainless steels, catalysts, and high temperature superconductors. In addition, we describe a number of related projects that are currently being carried out in the group, particularly those which utilise and develop novel STEM imaging and analytical techniques.
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Affiliation(s)
- A J McGibbon
- Cavendish Laboratory, Department of Physics, Cambridge University, England
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Hosokawa MC, Roberts CR, Hansen PL. Health education in rural Missouri: phase II. Health Educ 1984; 15:18-21. [PMID: 6444002] [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: 01/20/2023]
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Hansen PL. [Chronic headache caused by a poorly fitting denture]. Ugeskr Laeger 1976; 138:161-3. [PMID: 1108333] [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]
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Light LH, Cross G, Hansen PL. Non-invasive measurement of blood velocity in the major thoracic vessels. Proc R Soc Med 1974; 67:142-4. [PMID: 4821229 PMCID: PMC1645253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Hansen PL. Alcoholism. The development of an alcoholism unit in a private general hospital. Minn Med 1972; 55:577-9. [PMID: 5064187] [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: 01/13/2023]
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Steinhilber RM, Kuluvar VD, Anderson DJ, Heilman RO, Hansen PL. Symposium on the problem of the chronic alcoholic. Mayo Clin Proc 1967; 42:705-23. [PMID: 6053799] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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