GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Book
    Book
    New York : American Elsevier Publ.
    Keywords: Elektromagnetische Welle ; Fortpflanzung ; Elektromagnetische Welle ; Wellenausbreitung
    Type of Medium: Book
    Pages: VII, 126 S. , graph. Darst.
    Series Statement: Modern analytic and computational methods in science and mathematics [6]
    DDC: 537.1/2
    RVK:
    RVK:
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 34 (1930), S. 2771-2781 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 32 (1991), S. 2744-2763 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: In order to study the connections between Lagrangian and Hamiltonian formalisms constructed from a—perhaps singular—higher-order Lagrangian, some geometric structures are constructed. Intermediate spaces between those of Lagrangian and Hamiltonian formalisms, partial Ostrogradskii's transformations and unambiguous evolution operators connecting these spaces are intrinsically defined, and some of their properties studied. Equations of motion, constraints, and arbitrary functions of Lagrangian and Hamiltonian formalisms are thoroughly studied. In particular, all the Lagrangian constraints are obtained from the Hamiltonian ones. Once the gauge transformations are taken into account, the true number of degrees of freedom is obtained, both in the Lagrangian and Hamiltonian formalisms, and also in all the "intermediate formalisms'' herein defined.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
    Wound repair and regeneration 13 (2005), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction:  Chronic, nonhealing wounds are often observed in tissues with poor oxygen supply. Impaired reepithelialization is a hallmark of these wounds; however, the pathogenesis of the retarded reepithelialization in chronic, ischemic wounds remains poorly understood. Transforming Growth Factor beta (TGF-beta) is involved in both normal and hypoxic wound healing response and exogenous overexpression of Smad3, a TGF-beta signaling intermediate, has been known to accelerate reepithelialization. In a recent study, Ad-Smad3 injection in the rabbit ear dermal ulcer model showed enhanced reepithelialization and granulation tissue area suggesting a positive effect of Smad3 on wound healing. However, little is known about the role of Smad3 in the ischemic wound healing process. In this study we examined the effect of Smad3 in an ischemic wound model.Methods:  Ad-Smad3 or LacZ (108 pfu/wound) empty vector was injected in either ear of White New Zealand Rabbits. Twenty-four hours later, these ears were rendered ischemic using an established model and four 7-mm full-thickness punch wounds were made on each ear.Results:  Histological evaluation showed a highly significant increase in reepithelialization, epithelial ingrowth and percentage of epithelialization in Ad-Smad3 transfected wounds versus ischemic wounds transfected with LacZ-empty vector (p 〈 0.01).Conclusion:  Our data confirm the enhancing effect of Smad3 on reepithelialization in an ischemic wound model. The deficiency in reepithelialization, as evident in chronic ischemic wounds, could thus be ameliorated by excess Smad3. Therapeutic interventions using overexpressed Smad3 may improve wound healing through accelerated epithelialization in chronic wounds.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
    Wound repair and regeneration 13 (2005), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction:  Clinically, it has been observed that treatment with an occlusive dressing that results in hydration of the epidermis reduces scarring. A keratinocyte/fibroblast coculture system in which the epidermis is hydrated results in increased TNF production by keratinocytes, and reduced collagen synthesis by fibroblasts. We wished to test the hypothesis that in a nonhydrated coculture system, increasing TNF expression would result in decreased collagen synthesis by fibroblasts. Both keratinocytes and fibroblasts play essential role in scar formation. However, little is known about how TNF-alpha specific communication between these cell types modulates scar formation. To better elucidate this interaction, we used a keratinocyte/fibroblast coculture system to assess fibroblast function in a milieu of TNF-alpha overexpression by keratinocytes.Methods:  Primary human keratinocytes were transfected with adenovirus (MOI = 10) containing cDNA for TNF-alpha (AdTNF-alpha) or with LacZ and then cocultured with human dermal fibroblasts for 6 days.Results:  TNF-alpha transfected keratinocytes and their corresponding conditioned media showed a 3000-fold increase of TNF-alpha expression and synthesis in QRT-PCR and ELISA. Subsequent antibody blocking experiments with a specific TNF-alpha antibody showed a dose-dependent increase in collagen type 1 protein in the conditioned media. Col-1A1 mRNA expression in dermal fibroblasts was significantly reduced (p 〈 0.05).Conclusion:  Our data demonstrate that in a coculture setting, TNF-alpha expression by keratinocytes reduces Col-1A1 expression in fibroblasts and suggests a mechanism for clinical finding on the scar-reducing effects of hydration. This may bolster support for a TNF-alpha-mediated therapeutic intervention to ameliorate wound scarification.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
    Wound repair and regeneration 13 (2005), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The Hypoxia Inducible Factor (HIF) system has been characterized as the principal tissue level response to hypoxia. Posttranslational regulation of HIF-1alpha has been reported to act though a Hypoxia Responsive Element (HRE) promoter region on a range of hypoxia-induced genes. A plasmid was constructed consisting of a fivefold HRE repeat conjugated to a luciferase gene, used as a marker for HRE activation. Plasmid HRE-luciferase was then transfected into a well-established ischemic rabbit ear wound healing model. Ischemia was induced using a variety of published models for interruption of arterial inflow and compared with a nonischemic control. Central artery, caudal artery and rostrocaudal artery models were tested for induction of ischemia. Tissue specimens were harvested from the transfected areas and solubilized. Luminescence of each specimen was measured using a standard luminometer to quantify luciferase induction. To provide correlation on a regional level, tissue level oxygen tension was measured directly for each wound model. Profound and statistically significant differences were found in the induced luciferase production. Marked differences in the tissue hypoxia between the various ischemic wound healing models correlated in graded fashion with the ischemia induced on an anatomic basis. The least ischemic model showed no significant difference in hypoxia readings versus control. The intermediate model showed a significant fourfold greater ischemia signaling. The most ischemic model showed a highly significant 72-fold greater ischemic response compared to controls. The use of gene transfection is described as a sensitive and effective method for quantification of tissue hypoxia at a cellular level in ischemic wounds.Acknowledgments:  This study was funded by the Wound Healing Research Laboratory.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Science Ltd/Inc.
    Wound repair and regeneration 12 (2004), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Chronic wounds are characterized by a continued inability to heal after an extended period of time (often defined as 3 weeks or longer) and more commonly found in the elderly over areas of compromised blood flow. Collagen is a gene vital to this healing process and Transforming Growth Factor beta 1 (TGFβ1) is an important signaling molecule for collagen induction. We chose to examine the effects of age and ischemia on TGFβ1 regulation using the rat backflap model, which demonstrates negative influences of age and ischemia on the wound healing. Four full-thickness biopsy punches (7 mm) were made centered on the back of aged and young rats. The rostral wound pair was made ischemic by raising a transverse flap (1.8 cm wide × 8 cm length). The caudal wound pair served as a non-ischemic control. Wound contraction was prevented by insertion of a sterilized polyethylene sheet under both the ischemic and nonischemic wounds. RNA was then extracted from wounds at post operation days 3, 7, 10 and 14. The RNA was then reverse transcribed and assayed by Real-Time PCR to examine the relative expression of TGFβ1. TGFβ1 expression in the ischemic wounds of young rats was significantly increased versus nonischemic controls at post-wounding days 3, 7 and 14 (p 〈 0.05, p 〈 0.05, p 〈 0.05, respectively). We also observed a significant increase in TGFβ1 expression in the ischemic of aged animals at day 14 (p = 0.01). The data suggest that there is either a loss of function in TGFβ1’s response to ischemia in the aged animals, or, at least, a significant delay. The results also demonstrate the usefulness of the rat backflap model for the study of age and ischemia on TGFβ1 function in a non-contractile rat wound model.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Science Ltd/Inc.
    Wound repair and regeneration 12 (2004), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Epithelialization and vascularization are key elements involved in the repair of cutaneous wounds. One method of regulation for these pathways is expression of a signaling molecule known as Vascular Endothelial Growth Factor (VEGF), which, in turn, is regulated by the transcription factor Hypoxia-Inducible Factor-1 (HIF-1). It has been suggested that chronic wounds, which are most commonly located in ischemic tissue among the elderly, may be the result of a loss of function in the VEGF regulation pathway. Using our rat back flap model, which demonstrates the negative influences of age and ischemia on wound healing, we examined the relative expression of HIF-1 and VEGF in aged and young rats at 3,7, and 10 days post-wounding. Four full-thickness biopsy punches (7 mm) were made on the back of each aged and young rat. The rostral wound pair was made ischemic by raising a transverse flap (1.8 cm wide × 8 cm length). The caudal wound pair served as a non-ischemic control. Inserting a sterilized polyethylene sheet under both ischemic and nonischemic wounds prevented wound contraction. RNA was extracted from the tissue at the specified time points, and run on Real-Time PCR to determine relative expression of VEGF and HIF-1. Preliminary data suggest that, at the 3 day time point, there is a significant increase in both HIF-1 and VEGF expression in young rats under ischemic conditions and a significant increase in VEGF expression in aged rats under ischemia with a strong (but not significant) trend towards increase in HIF-1 as well. While the rat model does not produce significant differences between aged and young animals, this upregulation under ischemia indicates that HIF-1 and VEGF expression may play a vital role in the early signaling of ischemic wound repair.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 29 (1981), S. 0 
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: A nomogram has been devised for situations, in which the source of a self-potential anomaly can be approximated by an obliquely polarized sphere or horizontal cylinder embedded in a homogeneous half space. The nomogram can be used for rapid determination of three parameters of the target: (1) depth to the centre, (2) angle between the axis of polarization and the horizontal, (3) shift of the point vertically above the centre of the body from zero potential value.The nomogram has been tested and the parameters determined for SP results obtained over ore bodies Weiss and Süleymanköy in the Ergani Copper district, Turkey. The curves computed for the estimated parameters match the field curves well.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 90 (1968), S. 4494-4495 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...