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  • 11
    ISSN: 1432-2013
    Keywords: Heart function ; Postnatal development ; Thyroid hormones ; Sarcolemma ; Sarcoplasmic reticulum ; Ca2+ transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Newborn rats were rendered hyperthyroid (daily subcutaneous injections of L-triiodothyronine, 10 μg 100 g−1 body weight) or hypothyroid (0.05% 6-n-propyl-2-thiouracil in drinking water to nursing mothers) during the first 3 weeks of postnatal life. Compared with the euthyroid group, hyperthyroidism resulted in: (1) cardiac enlargement with right ventricular preponderance, (2) increased cardiac contractile function, (3) increased Ca2+ uptake by the sarcoplasmic reticulum (SR), (4) decreased sensitivity to the negative inotropic effect of verapamil and (5) greater inhibition of contractile function by ryanodine. Hypothyroidism generally resulted in opposite changes. The data suggest that the development of the heart and its contractile function during early postnatal life depends on the plasma level of thyroid hormones. In particular, the relative contribution of the SR and sarcolemmal Ca2+ transport to the control of cardiac contractility seems to be markedly affected by altered thyroid states. The postnatal maturation of the SR function is accelerated in hyperthyroidism but retarded in hypothyroidism. Consequently, hyperthyroid hearts appear to be less dependent and hypothyroid ones more dependent on trans-sarcolemmal Ca2+ fluxes when compared with age-matched euthyroid animals.
    Type of Medium: Electronic Resource
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  • 12
    ISSN: 1573-1561
    Keywords: Lepidoptera ; Pyralidae ; sex pheromone ; (Z,E)-9,11,13-tetradecatrienal ; mimic ; (Z,E)-7,9,11-dodecatrienyl formate ; wind tunnel ; attractant ; electrophysiology ; receptor cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The behavioral and electrophysiological activity of a mimic [(Z,E)7,9,11-dodecatrienyl formate] of the major sex pheromone component [(Z,E) 9,11,13-tetradecatrienal] of carob moth was assessed. Wind-tunnel bioassays demonstrated that the formate was as effective as natural gland extracts, and significantly more effective than the trienal alone or than the trienal blended with two minor pheromone components, in evoking source contact. Dispensers containing the formate were as effective as trienal-containing blend lures in attracting males when placed at the same dosage in traps in date gardens. Single-cell recordings showed that at least two olfactory neurons, differentiated by spike amplitude, are located in the long trichoid hairs on male carob moth antennae. Dose-response relationships indicated that puffs from cartridges loaded with at least 0.1 μg of the formate or of the trienal were necessary to elicit spiking by either the small or the large-spiking cell within a sensillum. Cross-adaptation studies demonstrated that both compounds stimulated the same large-spiking cell. The frequencies of spikes evoked from the large cell when stimulated by emissions from 0.1-μg, 1-μg, or 10-μg cartridges of either the formate or the trienal were not significantly different, suggesting that the formate is an effective mimic of the trienal at the antennal receptor cell level.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of epidemiology 8 (1992), S. 845-850 
    ISSN: 1573-7284
    Keywords: Colon cancer ; Risk factors ; Occupational activity ; Turkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case-control study of 107 colon cancer cases and 486 controls from an oncological clinic in Istanbul was conducted to examine the association between occupational physical activity and colon cancer in Turkey, where incidence of this disease is low. Only two of the four activity measures showed evidence of an increased colon cancer risk for sedentary jobs (time spent sitting OR= 1.5 and occupational energy expenditure OR= 1.6); neither was statistically significant. Subjects below age 55 showed higher risk associated with sedentary jobs than did the older age group, probably due to their adoption of a more western lifestyle, including dietary habits, less activity, and other factors that may interact to increase the risk of colon cancer.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 162 (1992), S. 614-624 
    ISSN: 1432-136X
    Keywords: Sulfhemoglobin ; Sulfide oxidation ; Blood ; Sulfide tolerance ; Cyprinodontidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sulfide can potentially damage hemoglobin or be detoxified by hemoglobin. In the sulfide-tolerant California killifish neither seems to be the case at environmentally realistic (micromolar) and physiologically relevant (millimolar) sulfide concentrations. An 8-h exposure of killifish to 5 and 8 mmol sulfide · 1-1 results in 50–100% mortality, but not due to sulfhemoglobin (where sulfide covalently binds to the porphyrin) nor ferric hemoglobin (Hb+), both dysfunctional hemoglobin derivatives. Killifish hemoglobin converts to sulfhemoglobin in vitro only in the presence of 1–5 mmol sulfide · 1-1. The amount of sulfhemoglobin formed increases with time and heme concentration but decreases with pH. Hb+ binds sulfide as ferric hemoglobin sulfide (Hb+S, an unstable complex where sulfide ligates to the iron), and also as sulfhemoglobin. Killifish blood does not catalyze the oxidation of 10–500 μmol sulfide · 1-1 to any appreciable extent. Radiolabeled sulfide incubated with oxyhemoglobin or whole blood disappears at rates greater than in buffers, but only minimal amounts of thiosulfate and no sulfate nor sulfite are formed (elemental sulfur and bound sulfide not quantified). Sulfide disappearance rates increase linearly with initial sulfide concentration. Hb+ does catalyze the oxidation of sulfide to thiosulfate in vitro. Similar experiments on another sulfide-tolerant species, the long-jawed mudsucker Gillichthys mirabilis, produced similar results.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 24 (1992), S. 161-164 
    ISSN: 1434-6079
    Keywords: 32.70.Jz ; 31.30.Gs ; 35.10.Bg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The use of an effusive beam of titanium atoms crossed with a CW single-mode tunable dye laser has allowed the high-resolution, Doppler-free study of the isotope shifts between50Ti,48Ti and46Ti, for seven 3d 2 4s 2 a3 F J → 3d 2 4s 4p z 5 D J , visible transitions of Ti I. The measurements show without ambiguity the existence of a non-negligible field shift. Using the values of the nuclear radii of titanium (coming from muonic X-ray measurements), it is possible to determine the respective values of the field and mass shifts.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 15 (1992), S. 300-312 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Thick-walled components subjected to pulsating internal pressure are widely applied in high-pressure technology and in manufacturing processes such as fluid-jet cutting and high-pressure cleaning, mainly in conjunction with reciprocating pumps. Corrosive fluids require high-strength and tough chrome-nickel steels with soft martensitic or semi-austenitic structure. This contribution reports on the fatigue of thick-walled plain and cross-bored pipes made from high alloy chrome-nickel steels such as X5 CrNiMoCu 21 8 and X5 CrNiMo 16 5. The speciments, uniaxial standard form and thick-walled pipes, were cut from forged blocks in the three axial directions. For loading with pulsating pressure, a suitable, high-frequency piston pulsation machine has been developed. The fatigue tests on pipe specimens show typical Woehler characteristics with only slight scatter and relatively good isotropy. The surprisingly large admissible pulsating pressure can be explained for the applied steels by dynamic generation of residual stresses as a result of shake-down effects. Presentation in a Smith digram explains the occuring dynamic shake-down and its favourable results in comparison to the more brittle highly tensile steels. It also reveals that heat treatment to higher tensile strength does not always yield an increase in the admissible pulsating pressure. It will be shown that static autofretting and shake-down affect the fatigue strength of thick-walled pipe specimens in the same way. Tests with internal liners in the tube specimens provide indications on the sensitivity of material failures towards fluids. The investigation aids the understanding of the fatigue behaviour and the design of components made of modern high-strength corrosion resistant steels.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
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  • 17
    ISSN: 1040-7685
    Keywords: capillary gas chromatography ; capillary supercritical fluid chromatography ; enantiomeric alcohols ; diastereomeric esters ; Trolox methyl ether ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enantiomers of aliphatic alcohols are transformed by a new chiral reagent (S)-Trolox methyl ether to their diastereomeric esters which are separated by capillary GC or SFC on achiral columns. The applicability of this reagent and its superiority to the hitherto known reagents are demonstrated by selected examples.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 64 (1992), S. 784-785 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 151 (1992), S. 215-227 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Human bone cells grown in culture, representative of a preosteoblastic stage of maturation, produce an extracellular matrix composed of collagen several noncollagenous glycoproteins, hyaluronan, and four distinct proteoglycans (PGs). The influence of donor age on the levels of expression of these molecules in vitro has not been well characterized. In this study, human bone cells derived from sources ranging from fetal to 60-year-old donors were grown in culture, radiolabeled for 24 h, and the amount of incorporation of [35S]sulfate into PGs, [3H]glucosamine into hyaluronan, [3H]leucine/proline into osteonectin, and [3H]proline into collagen was determined. Cell proliferation was most rapid in fetal-derived bone cells and decreased with increasing age. Total protein and PG synthesis also decreased with increasing age, falling to 1/3 and 1/4, respectively, of fetal levels after age 30. A large chondroitin sulfate PG (Mr ∼ 600,000 Da) was the major fetal PG and its levels were highly correlated with cellular proliferation. [3H]Collagen and [35S]decorin levels increased with the increasing age of the donor, reached a maximum in puberty-derived cells, and decreased to 1/3 maximal levels after age 20. The heparan sulfate PG (Mr ∼ 400,000 Da) exhibited steadystate levels regardless of donor age. [3H]Osteonectin and [35S]biglycan levels were high in fetal-derived cells and in cells derived from pubescent donors. The percentage of collagen and four proteoglycans associated with the cell layer pool changed with donor age. All fetal-derived PG core proteins possessed more N- and O-linked oligosaccharides than newborn or adult derived PGs. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 20
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; chromosome II ; RAD16 ; DNA helicase ; double-finger motif ; DNA excision repair ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have analysed a region some 30 kb centromere distal form PHO5 on the right arm of yeast chromosome II and determined the nucleotide sequence of a 8.95 kb DNA segment from this region. By this analysis we were able to derive the precise location and the transcriptional orientation of CMD1, ALG1, SSN6 and LYS2. An open reading frame of 2370 bp was locatlized between SSN6 and LYS2, which has recently been identified (Schild et al., 1991) to be the RAD16 gene. The putative gene product, 790 amino acids in length, reveals several interesting freatures. It contains a nuclear target singnature and shares several blocks of similarity with the yeast recombinational repair protein RAD54 and the nuclear factor SNF2 (SW12), which is required for teh transcriptioal activation of a number of yeast genes. The similarity blocks in these three proteins are reminiscent of those found in the helicase superfamily. Furthrmore, RAD16 contains a novel ‘double-finger’ motif, which has been encountered in a variety of proteins from different organisms that are suggested to interact with DNA and are involved in diverse functions including site-specific recombination, DNA repair, and transcriptional regulation. The putative gene product of RAD16 then is the first example of a proteins in which the novel double-finger motif is found to be combined with a poteintial DNA helicase framework.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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