751
|
|
752
|
Dreyfuss P, Keller A, Willmouth FM. Novel diffraction effects in the combined wide-angle and low-angle X-ray diffraction patterns of solution-grown nylon crystals. ACTA ACUST UNITED AC 1972. [DOI: 10.1002/pol.1972.160100507] [Citation(s) in RCA: 9] [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: 11/07/2022]
|
753
|
Diamant J, Keller A, Baer E, Litt M, Arridge RG. Collagen; ultrastructure and its relation to mechanical properties as a function of ageing. Proc R Soc Lond B Biol Sci 1972; 180:293-315. [PMID: 4402469 DOI: 10.1098/rspb.1972.0019] [Citation(s) in RCA: 375] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Tail tendons from Fischer and Sprague-Dawly albino rats of ages from 2 weeks to 3 years were investigated under the polarizing microscope as regards structure and deformation behaviour. Periodically extinguishing bands were observed along the otherwise featureless tendons. By analysing the behaviour of this extinction pattern under appropriate rotations of the tendon, it could be deduced that the orientation of the basic birefringent units varies periodically along the tendon and that this periodic pattern corresponds to a planar arrangement of the anisotropic entities. All the relevant parameters of this periodic structure could be determined in a representative manner from polarizing optics alone. Subdivision of the tendons revealed regularly undulating or rather crimped subunits in good correspondence to what has been deduced from the extinction bands in the intact tendons. The crimp angle was found to decrease while the periodicity increased - in approximate proportion to the length of the tail - with the age of the rat implying constancy of crimp number during the life time of the animal. On elongation the periodicity was gradually removed. The calculated fibre elongation necessary to eliminate the crimp was in good agreement with observation for mature rats but was larger for young rats implying the simultaneous stretching of the fibre itself. Stress-strain properties of tendons were measured and models for crimp straightening were tested. It was found that a model containing inflexible hinges, corresponding to the ‘elastica’ problem in mechanics gave reasonable fit with experiment. Analysis of stress-strain data on this basis leads to a basic load bearing unit, the diameter of which increases from 100 to 500 nm with the age of the animal. Implications of these findings for the structure and properties of the tendons, also in relation to ageing are pointed out.
Collapse
|
754
|
|
755
|
Folkes M, Keller A, Scalisi F. A test for molecular orientation in a ‘single crystal’ of SBS three-block copolymer by infra-red spectroscopy. POLYMER 1971. [DOI: 10.1016/0032-3861(71)90026-7] [Citation(s) in RCA: 9] [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: 10/27/2022]
|
756
|
Keller A, Udagawa Y. Fold surface of polyethylene single crystals as assessed by selective degradation studies. II. Refinements of the nitric acid degradation method. ACTA ACUST UNITED AC 1971. [DOI: 10.1002/pol.1971.160091005] [Citation(s) in RCA: 17] [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: 11/12/2022]
|
757
|
Keller A, Martuscelli E, Priest DJ, Udagawa Y. Fold surface of polyethylene single crystals as assessed by selective degradation studies. III. Application of the improved techniques to single crystals. ACTA ACUST UNITED AC 1971. [DOI: 10.1002/pol.1971.160091006] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
758
|
Keller A. Mexico City: a clinic dropout study. Stud Fam Plann 1971; 2:192-6. [PMID: 5128533] [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]
|
759
|
|
760
|
|
761
|
Udagawa Y, Keller A. Liquid-induced reversible long-spacing changes in polyethylene single crystals and their implications for the fold-surface problem. ACTA ACUST UNITED AC 1971. [DOI: 10.1002/pol.1971.160090305] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
762
|
Dlugosz J, Keller A, Pedemonte E. Electron microscope evidence of a macroscopic ‘single crystal’ from a three block copolymer. Colloid Polym Sci 1970. [DOI: 10.1007/bf02084718] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
763
|
Carr SH, Keller A, Baer E. Relationship between self-seeded and epitaxial crystallization from polymer solutions: A potentially new method for molecular weight separation and a new decoration method for alkali halides. ACTA ACUST UNITED AC 1970. [DOI: 10.1002/pol.1970.160080905] [Citation(s) in RCA: 16] [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: 11/09/2022]
|
764
|
Keller A, Willmouth FM. Self-seeded crystallization and its potential for molecular weight characterization. I. Experiments on broad distributions. ACTA ACUST UNITED AC 1970. [DOI: 10.1002/pol.1970.160080903] [Citation(s) in RCA: 14] [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: 11/09/2022]
|
765
|
Keller A, Sadler DM. Self-seeded crystallization and its potential for molecular weight characterization. II. Experiments on narrow fractions. ACTA ACUST UNITED AC 1970. [DOI: 10.1002/pol.1970.160080904] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
766
|
Sadler DM, Keller A. Polyethylene crystals with dislocation networks; their origin structure and relevance to polymer crystallization Part I. Colloid Polym Sci 1970. [DOI: 10.1007/bf02085913] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
767
|
|
768
|
|
769
|
Kobayashi Y, Keller A. The temperature coefficient of the c lattice parameter of polyethylene; an example of thermal shrink̄age along the chain direction. POLYMER 1970. [DOI: 10.1016/0032-3861(70)90030-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
770
|
Keller A, Pedemonte E, Willmouth FM. Macro-lattice from Segregated Amorphous Phases of a Three Block Copolymer. Nature 1970; 225:538-9. [PMID: 16056598 DOI: 10.1038/225538a0] [Citation(s) in RCA: 211] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/1969] [Indexed: 11/08/2022]
Affiliation(s)
- A Keller
- University of Bristol, H.H. Wills physics Laboratory, Royal Fort
| | | | | |
Collapse
|
771
|
|
772
|
Williams T, Udagawa Y, Keller A, Ward IM. Determination of the molecular weight spread of narrow peaks in the gel-permeation chromatograms of nitric acid-degraded polyethylene. ACTA ACUST UNITED AC 1970. [DOI: 10.1002/pol.1970.160080103] [Citation(s) in RCA: 12] [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: 11/11/2022]
|
773
|
Keller A, Udagawa Y. Preparation of long-chain paraffins from nitric acid degradation products of polyethylene; some consequences for polymer crystal structure studies. ACTA ACUST UNITED AC 1970. [DOI: 10.1002/pol.1970.160080102] [Citation(s) in RCA: 9] [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: 11/11/2022]
|
774
|
Keller A, Vetter WF. [Asepsis and surgery in a hospital in the Vaud zone]. Helv Chir Acta 1969; 36:519-23. [PMID: 5376436] [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: 01/14/2023]
|
775
|
|
776
|
Kovacs AJ, Lotz B, Keller A. Multiple twinning in polyethylene oxide single crystals-a scheme for the formation of growth twins from self-seeding nuclei. J MACROMOL SCI B 1969. [DOI: 10.1080/00222346908217100] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
777
|
|
778
|
|
779
|
Willmouth FM, Keller A, Ward IM, Williams T. Gel permeation chromatographic studies of the degradation of polyethylene with fuming nitric acid. III. Fibrous stirring-induced crystals. ACTA ACUST UNITED AC 1968. [DOI: 10.1002/pol.1968.160060908] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
780
|
Williams T, Blundell DJ, Keller A, Ward IM. Gel permeation chromatographic studies of the degradation of polyethylene with fuming nitric acid. I. Single crystals. ACTA ACUST UNITED AC 1968. [DOI: 10.1002/pol.1968.160060906] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
781
|
Williams T, Keller A, Ward IM. Gel permeation chromatographic studies of the degradation of polyethylene with fuming nitric acid. II. Bulk polyethylene. ACTA ACUST UNITED AC 1968. [DOI: 10.1002/pol.1968.160060907] [Citation(s) in RCA: 15] [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: 11/07/2022]
|
782
|
|
783
|
Blundell DJ, Keller A. Submikroskopische Keimkristalle bei der Lösungskristallisation des Polyäthylens. Angew Chem Int Ed Engl 1968. [DOI: 10.1002/ange.19680801032] [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: 11/06/2022]
|
784
|
|
785
|
Blundell DJ, Keller A, Connor TM. Investigation of the fold-surface problem in polyethylene single crystals with the nitric acid oxidation technique. ACTA ACUST UNITED AC 1967. [DOI: 10.1002/pol.1967.160050601] [Citation(s) in RCA: 30] [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: 11/07/2022]
|
786
|
Fröhlich C, Keller A, Eggstein M. [On the differential diagnostic value of comparative LDH activity determinations in pleural effusion and blood serum. Studies using LDH-isoenzyme separation]. Klin Wochenschr 1967; 45:832-9. [PMID: 5592451 DOI: 10.1007/bf01745559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
787
|
|
788
|
|
789
|
Fröhlich C, Keller A. [Lactate dehydrogenase isoenzyme pattern in pleural effusions of benign and malignant etiology and its diagnostic significance]. Klin Wochenschr 1967; 45:457-61. [PMID: 5585804 DOI: 10.1007/bf01717431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
790
|
Blundell DJ, Keller A, Ward IM, Grant IJ. Examination of degraded polyethylene single crystals by gel permeation chromatography. ACTA ACUST UNITED AC 1966. [DOI: 10.1002/pol.1966.110041021] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
791
|
Blundell DJ, Keller A, Kovacs AJ. A new self-nucleation phenomenon and its application to the growing of polymer crystals from solution. ACTA ACUST UNITED AC 1966. [DOI: 10.1002/pol.1966.110040709] [Citation(s) in RCA: 306] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
792
|
Lotz B, Kovacs AJ, Bassett GA, Keller A. Properties of copolymers composed of one poly-ethylene-oxide and one polystyrene block. ACTA ACUST UNITED AC 1966. [DOI: 10.1007/bf01500629] [Citation(s) in RCA: 174] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
793
|
|
794
|
|
795
|
Kawai T, Charlesby A, Keller A, Ormerod M. Relation between radiation induced physical changes and crystalline ordering in polyethylene. POLYMER 1964. [DOI: 10.1016/0032-3861(64)90174-0] [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: 10/27/2022]
|
796
|
Keller A. Introductory talk: Recent results, trends and problems in the research on the morphology of crystalline polymers. POLYMER 1964. [DOI: 10.1016/0032-3861(64)90162-4] [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: 10/27/2022]
|
797
|
|
798
|
|
799
|
|
800
|
|