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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 154 (1990), S. 414-416 
    ISSN: 1432-072X
    Keywords: Cyanobacterium ; Ammonium assimilation ; Glutamine auxotrophy ; Transformation ; MSX-resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glutamine auxotrophic (Gln -) and l-methionine d,l-sulfoximine (MSX) resistant (MSX r) mutants of N. muscorum were isolated and characterized for nitrogen nutrition, nitrogenase activity, glutamine synthetase (GS) activity and glutamine amide, α-keto-glutarate amido transferase (GOGAT) activity. The glutamine auxotroph was found to the GOGAT-containing GS-defective, incapable of growth with N2 or NH 4 + but capable of growth with glutamine as nitrogen source, thus, suggesting GS to be the primary enzyme of both ammonia assimilation and glutamine formation in the cyanobacterium. The results of transformation and reversion studies suggests that glutamine auxotrophy is the result of a mutation in the gln A gene and that gln A gene can be transferred from one strain to another by transformation.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 129 (1994), S. 97-99 
    ISSN: 0942-0940
    Keywords: Multipurpose head frame ; neuronavigator ; stereotaxis ; instrumentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A newly designed attachment device of the multipurpose head frame (Sugita) for Neuronavigator (Watanabe) is presented with an illustrative case of glioblastoma in an eloquent area. This has extended the usefulness of the neuronavigator for those who prefer and use the multipurpose head frame, while the requirements for keeping a stereotactic combination and the original concept of the multipurpose head frame, as well as that of the neuronavigator have been kept undisturbed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 82 (1991), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: In Nostoc muscorum (Anabaena ATCC 27893) glutamate was not metabolised as a fixed nitrogen source, rather it functioned as an inhibitor of growth. The latter effect was nitrogen source specific and occurred in N2-fixing cultures but not in cultures assimilating nitrate or ammonium. NO3--grown cultures lacked heterocysts and nitrogenase activity and showed a nearly 50% reduction in glutamate uptake rates, as well as in the final extent of glutamate taken up, compared to N2-fixing or nitrogen-limited control cultures. NH4+-grown cultures showed a similar response, except that the reduction in glutamate uptake rates and the final exten of glutamate taken up was over 80%. The present results suggest a relation between nitrate/ammounium nitrogen-dependent inhibition of glutamate uptake, probably via repression of the glutamate transport system, and glutamate toxicity.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Changes in visual evoked potentials, visual acuity, blood ammonia levels and serum electrolytes (Na+ and K+) after transurethral resection of the prostate using glycine as an irrigating fluid performed under subarachnoid block were studied in 12 patients, in the pre-operative and immediate postoperative periods. Visual evoked potentials (p100 latency), recorded by shift of a checkerboard pattern, increased significantly from a pre-operative value of mean (SEM) 101.18 (1.63) msec in the right eye, and 102.5 (1.47) msec in the left eye to 108.91 (1.8) msec (p 〈 0.01) and 108.08 (2.53) msec (p 〈 0.01) respectively in the postoperative phase. There were no changes in visual acuity as assessed by a Snellen's chart, blood ammonia levels and serum electrolyte concentrations. The amount of glycine used intra-operatively for irrigation ranged from 3 to 31 litres.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 107 (1991), S. 0 
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Hybridization followed by pedigree selection was carried out between two autotetraploid strains of fenugreek (Trigonella foenum-graecum L.). Morphological and cytological investigations were carried out in two autotetraploid parents, their F1 hybrids and F6 lines derived from F1 after selfing. Cytomorphological data of F6 lines were compared with those of F1, hybrids and of their parents. The hybrid plants were intermediate with respect to different vegetative traits, however, they showed increased seed set as compared to their autotetraploid parents. The mean pod number per plant in F6 was one and half times as high as one of the high yielding tetraploid parents and approximately twice as high as that of F1 hybrid. Meiosis in F6 was more regular than in F, and the parents. Thus, hybridization followed by pedigree selection is helpful not only in regularizing the meiotic behavior, but vigour and seed fertility have also improved in autotetraploid fenugreek.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 3452-3455 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The formation of good quality epitaxial c-axis-perpendicular YBa2 Cu3 O7 superconducting thin films on (100) yttria-stabilized-zirconia (YSZ) substrates in the temperature range of 550–650 °C by a biased laser deposition method is reported. However, below 550 °C, the epitaxial quality of the films decreased appreciably with corresponding changes in the superconducting properties. For temperatures much below the critical temperature, the critical current density showed a linear variation with temperature, with a value of 1.0×106 A/cm2 at 77 K and zero magnetic field. Because of the lattice mismatch between the substrate and the film, the interface was found to be highly strained in the presence of a large number of defects. The epitaxial nature and the crystalline quality of the films were determined by a number of techniques including Rutherford backscattering/channeling, electron channeling, cross-section transmission electron microscopy (TEM), and x-ray diffraction techniques. Rutherford backscattering channeling showed a minimum channeling yield of about 18%–25% for films deposited at and above 550 °C. Cross-section TEM and x-ray diffraction revealed the following thin film and substrate relationships: [001]film (parallel)[001]YSZ and [110]film (parallel)[100]YSZ. The electron channeling pattern taken from a large area confirmed the epitaxial relationship. The lattice parameters mismatch in this orientation has been found to gives rise to stresses near the interface.
    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 67 (1990), S. 3448-3451 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Reliable critical current density measurements have been sucessfully carried out on superconducting thin films which were in situ patterned during the laser deposition process. This method does not require cumbersome wet etching or post-ion-implantation patterning steps for measuring transport critical current densities of thin films. Epitaxial films of YBa2Cu3O7 on (100) SrTiO3 and (100)yttria-stabilized ZrO2 (YSZ) were fabricated at low processing temperatures (500–650 °C) by the excimer laser ablation technique in an oxygen ambient coupled with a dc bias voltage of +300 V on an interposing ring between the substrate and the target. Steel masks of various lateral dimensions were placed close to the substrate to generate various patterns. The superconducting properties obtained at the masked and unmasked areas of the film were similar and reproducible. The thickness and width of the mask have been found to be critical in controlling the superconducting properties of the patterned thin films. Excellent quality superconducting thin films were obtained in the patterned areas. The critical temperature of the films was found to lie in the range of 88–90 K, and the best critical current density values (at 77 K and zero magnetic field) of 1.0×106, 5.0×106, and 6.5×106 A/cm2 were obtained for films deposited on (100) YSZ, (100) SrTiO3 , and (100) LaAlO3 , respectively.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 2926-2930 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Two-dimensional structures in a plane perpendicular to the magnetic field, of the low-frequency turbulence in a toroidal plasma, have been studied. The probability distribution functions for the density and the potential fluctuations are found to deviate from the Gaussian distribution significantly indicating intermittency in the turbulence and formation and destruction of the coherent structures in the strongly turbulent state. The presence of such short-lived structures has been established, on a statistical basis, by means of conditional averaging of the fluctuation amplitudes.
    Type of Medium: Electronic Resource
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  • 9
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    Unknown
    Worcester, Mass. : Periodicals Archive Online (PAO)
    Journal of Social Psychology. 130 (1990) 533-541 
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 48 (1992), S. 655-657 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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