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  • 1
    ISSN: 0931-1890
    Keywords: Key words Maximum density ; Cell wall thickness ; Radial cell diameter ; Climatic factors ; Picea glehnii Mast.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  An investigation was made of the effects of tracheid dimensions on variations in the maximum density of Picea glehnii Mast., which were associated with climatic changes. Radial cell diameter and the thickness of the tangential cell walls of the last-formed cells in 90 annual rings of nine trees with different annual ring widths were analyzed by image analysis. Correlations between maximum density and tracheid dimensions indicated that changes in maximum density were due mainly to changes in cell wall thickness of the last-formed cells in annual rings and were not due to changes in radial cell diameter. The effects of climatic factors on tracheid dimensions were examined by application of dendroclimatological techniques. A chronology of cell wall thickness that represented common signals among trees was established. Simple correlation and response function analyses of the chronology revealed that cell wall thickness was influenced positively by summer temperature and negatively by precipitation in August, and these responses were similar to those of maximum density. The study demonstrated that variations in maximum density were due to variations in the cell wall thickness of the last-formed cells, which varied depending on the weather in summer.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0931-1890
    Keywords: Key words Dendrochronology ; Abrupt growth changes ; Pointer years ; Air pollution ; Drought
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Increments in the radii of Norway spruce (Picea abies Karst.) and Yezo spruce (Picea jezoensis Carr.) trees that revealed symptoms of a decline in growth were analyzed by dendrochronological methods in an attempt to correlate past reductions in growth with their main causes. The trees were growing at different sites near the industrial district of Tomakomai, Hokkaido. A skeleton plot method was used to construct a series of pointer years that revealed the number of trees with a clear reduction in growth or recovery from such a reduction. An analysis of “abrupt growth changes” demonstrated that at least two periods of growth reduction were common to a large number of Norway spruce trees. The reduction events were related to the records of industrial activity near the forest and meteorological data. The growth reduction in the 1970s coincided with the start of operation of certain local factories, and its extent was related to the distance from the industrial region. By contrast, a reduction in growth in 1984 was detected at all the Norway spruce sites and the extent was approximately the same at all sites. This phenomenon was related to extreme drought conditions. Growth of Yezo spruce trees was less sensitive to industrial activity and to drought than that of Norway spruce. Thus, differences in response to air pollution and drought were observed between the two species.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 199 (1994), S. 1453-1460 
    ISSN: 0006-291X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Gene Structure and Expression 1216 (1993), S. 165-169 
    ISSN: 0167-4781
    Keywords: (S. melongena) ; Cytochrome P-450 ; Gene family ; Seedling
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Chemical Physics Letters 73 (1980), S. 178-180 
    ISSN: 0009-2614
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial and engineering chemistry 18 (1979), S. 373-375 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 6631-6633 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mechanical strength and properties of thin plates were investigated for hot-rolled Pr-Fe-B-Cu magnets. Tensile strengths of the hot-rolled magnets were more than 23.7 kg f/mm2. Bending tests were also applied and the strength of 37.7 kg f/mm2 was obtained. The strengths obtained are definitely higher than that of commercial Nd-based sintered magnets. It was found that the mechanical strengths were enhanced by Pr2Fe14B grain refinement caused by Cu addition. Related to high mechanical strength, hot-rolled Pr-Fe-B-Cu magnets show excellent machinability. Thin plate magnets up to 0.1 mm in thickness with fairly large surface area were produced without any cracking. Moderate energy products better than 20 MGOe were achieved by heat treatment after machining.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 5290-5292 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new process has been developed to produce high-energy bulk Pr-Fe-B magnets directly from the melt without the handling of magnetic powder or powderlike ribbons. The process mainly consists of only three steps—casting/hot pressing/annealing—and minimizes the oxygen contamination of magnets. A typical composition of cast alloy is Pr17 Fe76.5 B5 Cu1.5 . Using this type of alloy, a magnetic alignment is easily introduced by hot pressing. Copper plays two important roles: high coercivity and excellent magnetic alignment are achieved simultaneously by the addition of copper. Magnetic properties of hot-pressed Pr17 Fe76.5 B5 Cu1.5 magnets are as follows: Br=12.5 kG, i Hc =10.0 kOe, and (BH)max =36.2 MGOe. The cast alloy of this composition also has an i Hc of 7.4 kOe and a (BH)max of 8.8 MGOe after annealing at 1000 °C for 24 h. The steep rise in the initial magnetization curve indicates a type of nucleation-controlled coercivity mechanism.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 5829-5831 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The hot workability of R-Fe-B alloys and their magnetic properties were extensively investigated. Modified hot pressing employing a ring which constrains an alloy ingot enabled hot working without cracking at high strain rates up to ε(overdot) = 1 × 10−1/s. Excessive discharging of the liquid R-rich phase was controlled and the refinement of crystal grains occurred at high strain rate hot pressing. Through these effects the maximum Hci reached 18 kOe, and a (BH)max of 33.3 MGOe with a moderate Hci of 15 kOe was obtained in a composition of the Pr-Fe-B-Cu system. Post-heat treatment at 475–525 °C was effective for enhancing Hci. It was found that even in Nd-based alloys, a (BH)max of more than 30 MGOe was achieved by hot pressing at a high strain rate, because the change in composition during pressing is minimized.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cyclooxygenase-2 (COX-2) is one of the rate-limiting enzymes for prostaglandin synthesis from arachidonic acid. Although it is known that inhibition of cyclooxygenase activity delays ulcer healing, the regulatory relationship between COX-2 and its metabolites in gastric epithelial cell proliferation is not well known.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To investigate whether COX-2 has an effect on gastric mucosal cell proliferation and further studied whether such effect is mediated only by prostaglandin E2 (PGE2), a representative metabolite of arachidonates in the gastric mucosa.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:Artificial wounds of defined area size were created on complete monolayer cell sheets of isolated rat gastric epithelial cells and rat gastric cell line RGM1 under the addition of arachidonic acid or a COX-2 selective inhibitor, JTE522. Repair of wounds was assessed by monitoring wound size, with cell proliferation detected using 5-bromodeoxyuridine staining. Quantity of secreted PGE2 was measured by enzyme immunoassay.〈section xml:id="abs1-4"〉〈title type="main"〉Results:Stimulation of foetal calf serum increased the expression of COX-2 protein and inhibition of COX-2 retarded wound healing with reduction of cell proliferation. Arachidonic acid increased PGE2 production and accelerated restoration. Combination of JTE522 and arachidonic acid resulted in a marked retardation of wound healing compared to the control, but JTE522 did not completely suppress the increase in cellular PGE2 content following the addition of arachidonate.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:The difference in the effects of JTE522 on PGE2 production and on wound healing suggest that the involvement of COX-2 in gastric epithelial cell proliferation is not mediated solely by PGE2.
    Type of Medium: Electronic Resource
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