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  • 1
    Electronic Resource
    Electronic Resource
    Modelling of the kinetics and parametric behaviour of a copper vapour laser: Output power limitation issues (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 71-83 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A self-consistent computer model was used to simulate the plasma kinetics (radially resolved) and parametric behaviour of an 18 mm bore (6 W) copper vapour laser for a wide range of optimum and non-optimum operating conditions. Good quantitative agreement was obtained between modelled results and experimental data including the temporal evolution of the 4p2P3/2, 4s2 2D5/2 and 4s22D3/2 Cu laser level populations derived from hook method measurements. The modelled results show that the two most important parameters that affect laser behaviour are the ground state copper density and the peak electron temperature Te. For a given pulse repetition frequency (prf), maximum laser power is achieved by matching the copper atom density to the input pulse energy thereby maintaining the peak Te at around 3 eV. However, there is a threshold wall temperature (and copper density) above which the plasma tube becomes thermally unstable. At low prf (〈8 kHz), this thermal instability limits the attainable copper density (and consequently the laser output power) to values below the optimum for matching to the input pulse energy. For higher prf values (〉8 kHz), the copper density can be matched to the input pulse energy to give maximum laser power because the corresponding wall temperature then falls below the threshold temperature for thermal instability. For prf 〉14 kHz, the laser output becomes highly annular across the tube diameter due to a severe depletion of the copper atom density on axis caused by radial ion pumping. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.365851
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  • 2
    Electronic Resource
    Electronic Resource
    Detection of high-risk groups and individuals for periodontal diseases: laboratory markers based on the microbiological analysis of subgingival plaque (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of clinical periodontology 17 (1990), S. 0 
    Details
    ISSN: 1600-051X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract Periodontal microbiology is reviewed with regard to the potential of certain characteristics to serve as markers of high risk groups or individuals for periodontal diseases. The generally accepted associations between particular organisms and the various periodontal diseases are discussed. The usefulness of various clinical study designs is reviewed. The ecology of the subgingival plaque microflora is discussed and a number of suggestions for future research are made. We have concluded that there is no monospecific aetiology to any of the various periodontal conditions. Nevertheless, we give particular attention to the role of the black-pigmented bacteroides based upon our belief that they, and Bacteroides gingivalis in particular, are fundamental to our understanding of the biology of periodontal diseases in humans and other animals. Consequently, the contribution of its various virulence factors and their potential as markers of disease susceptibility and activity is addressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-051X.1990.tb01040.x
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  • 3
    Electronic Resource
    Electronic Resource
    Specific antibody responses to subgingival plaque bacteria as aids to the diagnosis and prognosis of destructive periodontitis (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of clinical periodontology 18 (1991), S. 0 
    Details
    ISSN: 1600-051X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract We have reviewed the recent literature on the humoral immune responses to a variety of subgingival plaque bacterial species in patients with destructive periodontal diseases. We do not feel that the information presently available on the specific antibody responses to proposed pathogens such as Bacteroides gingivalis and Actinobacillus actinomycetemcomitans allows antibody responses to be diagnostic. All control subjects without periodontal destruction have antibodies to candidate pathogens but the generally higher levels in patients are not sufficiently elevated to be diagnostic. Nor can they be used to predict the initiation of disease or the onset of new episodes of destruction where disease had previously occurred. Successful treatment of patients may lead to lower levels of antibodies to some organisms, including possible pathogens, and thus support a given species in the aetiopathogenesis of disease. It appears that unsuccessful treatment may be accompanied by continuing high antibody levels to some organisms and further studies may enable this observation to be used to monitor therapy. There is some evidence from serological studies that each destructive episode may be induced by a different bacterial species or consortium. The start of studies using single antigens and the techniques of molecular biology will provide not only antibody-based diagnostic methods but also allow us to determine which bacterial antigens are virulence factors and thus the role of the antibody responses, whether protective or damaging, in the periodontal diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-051X.1991.tb01112.x
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  • 4
    Electronic Resource
    Electronic Resource
    The role of histopathology in the diagnosis and prognosis of periodontal diseases (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of clinical periodontology 17 (1990), S. 0 
    Details
    ISSN: 1600-051X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract The histological evaluation of surgical biopsies from affected tissues is a standard way of assessing pathological change and determining treatment in many diseases. In most forms of periodontal disease, however, this approach finds limited application. Here, we review what uses the histopathological approach has in the study and evaluation of the periodontal diseases. Current understanding of the changes in epithelial anatomy during pocket formation, the cellular composition and dynamics of the inflammatory infiltrate and the mechanisms of bone resorption and repair are reviewed from the perspective of the information available from microscopical investigation, including the uses and potential application of modern immunocytochemical methods to these questions. The usefulness of histological study of biopsy material is reassessed in the light of advances made in immunohistochemical techniques and their application to gingival inflammatory infiltrates and epithelia. Such techniques offer immediately valuable research opportunities with potential for diagnostic applications, noteably the recognition of phases of destructive activity and their differentiation from periods of effective host defence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-051X.1990.tb01053.x
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    Paper (German National Licenses)
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