ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 48 (1974), S. 73-80 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract A mineralogical nomenclature applicable to the natural binary isomorphous series ZrSiO4-HfSiO4 is proposed. It is suggested that (Hf, Zr)SiO4 with more than 90 mol.-% hafnium component be called hafnon. Zoned crystals ranging in composition from hafnian zircon to hafnon were found in the heavy mineral concentrates from the tantalum pegmatites of the Morrua area, Conco, Moneia and Muiane mines in the district of Zambézia, Mozambique. The density (Berman balance), Hf/Zr ratio (XRF analysis) and unit-cell parameters (X-ray powder pattern) of the samples are determined and discussed. Two microprobe analyses of hafnon from Muiane are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-4889
    Keywords: titanium ; oxidation ; oxide scale ; solid state diffusion ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxidation behavior of titanium was studied over the temperature range of 600 to 800°C in a pure oxygen atmosphere. A parabolic kinetics period is made up of a succession of short parts whose weight gain is nearly constant and whose beginning is characterized by an alteration of the oxidation rate. The kinetics curve is closely correlated with the morphology of the oxide scale which contains several layers separated by short cracks. These cracks decrease the diffusional flows of oxygen and titanium and alter the oxidation rate. A parabolic-linear kinetics transition is attributed to the formation of a continuous crack between the oxide scale and the matrix. The oxide scale then forms a porous barrier of constant thickness which induces a linear rate law due to the steady-state oxygen diffusion. Titanium cannot diffuse across the continuous crack. During the linear kinetics period several layers of constant thickness, separated by a continuous crack, spread out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-4889
    Keywords: oxidation ; titanium ; Ti-Ni alloy ; Ti-Cu alloy ; kinetics ; oxide scale ; solid-state diffusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The kinetics and morphologic oxidation properties of titanium, Ti-1.5Ni and Ti-2.5Cu were compared. Titanium and Ti-1.5Ni have a similar behavior, concerning the kinetics and the oxide micro structure. Copper additions decrease the oxidation rate of titanium. The oxide scales formed on Ti-Cu are thinner and less cracked than those obtained on Ti or Ti-1.5Ni. Copper is found in the oxide scale of Ti-Cu, whereas nickel is not found in the oxide scale of Ti-Ni. The oxidation of titanium and its alloys is controlled chiefly by diffusional phenomena in the oxide scale. Thus the alterations of the oxide scale structure and the slower oxidation rate of Ti-2.5Cu can be attributed to the copper which diffuses towards the gas-oxide interface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2008-03-28
    Description: T helper cells that produce IL-17 (T(H)17 cells) promote autoimmunity in mice and have been implicated in the pathogenesis of human inflammatory diseases. At mucosal surfaces, T(H)17 cells are thought to protect the host from infection, whereas regulatory T (T(reg)) cells control immune responses and inflammation triggered by the resident microflora. Differentiation of both cell types requires transforming growth factor-beta (TGF-beta), but depends on distinct transcription factors: RORgammat (encoded by Rorc(gammat)) for T(H)17 cells and Foxp3 for T(reg) cells. How TGF-beta regulates the differentiation of T cells with opposing activities has been perplexing. Here we demonstrate that, together with pro-inflammatory cytokines, TGF-beta orchestrates T(H)17 cell differentiation in a concentration-dependent manner. At low concentrations, TGF-beta synergizes with interleukin (IL)-6 and IL-21 (refs 9-11) to promote IL-23 receptor (Il23r) expression, favouring T(H)17 cell differentiation. High concentrations of TGF-beta repress IL23r expression and favour Foxp3+ T(reg) cells. RORgammat and Foxp3 are co-expressed in naive CD4+ T cells exposed to TGF-beta and in a subset of T cells in the small intestinal lamina propria of the mouse. In vitro, TGF-beta-induced Foxp3 inhibits RORgammat function, at least in part through their interaction. Accordingly, lamina propria T cells that co-express both transcription factors produce less IL-17 (also known as IL-17a) than those that express RORgammat alone. IL-6, IL-21 and IL-23 relieve Foxp3-mediated inhibition of RORgammat, thereby promoting T(H)17 cell differentiation. Therefore, the decision of antigen-stimulated cells to differentiate into either T(H)17 or T(reg) cells depends on the cytokine-regulated balance of RORgammat and Foxp3.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597437/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597437/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhou, Liang -- Lopes, Jared E -- Chong, Mark M W -- Ivanov, Ivaylo I -- Min, Roy -- Victora, Gabriel D -- Shen, Yuelei -- Du, Jianguang -- Rubtsov, Yuri P -- Rudensky, Alexander Y -- Ziegler, Steven F -- Littman, Dan R -- AI48779/AI/NIAID NIH HHS/ -- R01 AI048779/AI/NIAID NIH HHS/ -- R01 AI048779-05/AI/NIAID NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 May 8;453(7192):236-40. doi: 10.1038/nature06878. Epub 2008 Mar 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York 10016, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18368049" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Differentiation/drug effects ; Cell Line ; Cells, Cultured ; Forkhead Transcription Factors/genetics/*metabolism ; Gene Expression Regulation/drug effects ; Humans ; Interleukin-17/biosynthesis/genetics/*metabolism ; Mice ; Mice, Inbred C57BL ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; Receptors, Interleukin/genetics/metabolism ; Receptors, Retinoic Acid/*antagonists & inhibitors/genetics/metabolism ; Receptors, Thyroid Hormone/*antagonists & inhibitors/genetics/metabolism ; T-Lymphocytes, Helper-Inducer/*cytology/*drug effects/metabolism ; Transforming Growth Factor beta/*pharmacology
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 1974-01-01
    Print ISSN: 0010-7999
    Electronic ISSN: 1432-0967
    Topics: Geosciences
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...