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  • 1
    Electronic Resource
    Electronic Resource
    Non-linear structures in the non-critical NSR string (1996)
    Springer
    Communications in mathematical physics 176 (1996), S. 401-420 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We investigate the Ward identities of theW ∞ symmetry in the super-Liouville theory coupled to the super-conformal matter of central charge $$\hat c_M = 1 - 2(p - q)^2 /pq$$ . The theory is classified into two chiralities. For the positive chirality, all gravitationally dressed scaling operators are generated from theq−1 gravitational primaries by one of the ring generators in the R-sector acting on them repeatedly. After fixing the normalizations of the dressed scaling operators, we find that the Ward identities are expressed in the form of theusual W q algebra constraints as in the bosonic case:W n (k+1) ,τ=0, (k=1,...,q−1;n∈Z≧1−k), where the equations for even and oddn come from the currents in the NS- and the R-sector respectively. The non-linear terms come from the anomalous contributions at the boundaries of moduli space. The negative chirality is defined by interchanging the roles ofp andq. Then we get theW p algebra constraints.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02099555
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  • 2
    Electronic Resource
    Electronic Resource
    Preparation and critical current density of hot pressed Bi2Sr2Ca2Cu3Ox/Ag tapes (1998)
    Springer
    Journal of materials science 33 (1998), S. 1293-1297 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Bi2Sr2Ca2Cu3Ox(Bi-2223)/Ag tapes have been prepared by hot pressing performed at 800–840 °C for 12–96 h under 6 or 12 MPa in air. The highest transport critical current density, Jc, is 3900 A cm−2 at 77 K and 8800 A cm−2 at 65 K under zero magnetic field, which is observed in tape hot pressed at 820 °C under 12 MPa for 24 h twice. The tape has undergone a cold pressing under 260 MPa between hot pressings. Jc is limited to 120 A cm−2 in tape hot pressed for 48 h continuously, in spite of total hot pressing time, temperature and pressure all being the same as for tape hot pressed for 24 h twice. It is found that alternate hot pressing and cold pressing is effective in the preparation of Bi-2223 tapes with high Jc, which is determined by the strength of grain coupling. Grain coupling is strengthened in tape hot pressed with an intermediate cold pressing. © 1998 Chapman & Hall
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004398230888
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  • 3
    Electronic Resource
    Electronic Resource
    Electron-microscopic study on the anterior pituitary gland of spontaneous dwarf rats (1989)
    Springer
    Cell & tissue research 258 (1989), S. 477-482 
    Details
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; Electron microscopy ; Growth hormone ; Spontaneous dwarf rats (dr/dr)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The spontaneous dwarf rat is a novel experimental model animal on the study of pituitary dwarfism. The fine structure of the anterior pituitary cells was studied in the immature and mature dwarf rats. Pituitary glands were removed from 5-, 10-, 20-day-old immature dwarfs, adult (45 days-16 weeks) dwarfs and normal 3-month-old rats and processed for electron-microscopic observation. In the control animals, growth hormone cells were readily identified by their ultrastructural characteristics, such as the presence of numerous electron-dense secretory granules, 300–350 nm in diameter, well developed rough endoplasmic reticulum and a prominent Golgi complex. In contrast, growth hormone cells were not found in the anterior pituitary gland of the spontaneous dwarf rat at any age examined. Other pituitary cell types, i.e., luteinizing hormone/ follicle stimulating hormone, thyroid stimulating hormone, adrenocorticotropic hormone and prolactin cells, appeared similar in their fine structure to those found in the control rats. In the pituitary gland of dwarf rats, a number of polygonal cells were observed either with no or relatively few secretory granules. The rough endoplasmic reticulum was arranged in parallel cisternae and the Golgi complex was generally prominent in these cells. In addition, many were found to have abundant lysosomes. A few minute secretory granules were occasionally observed; however, the immunogold technique failed to localize growth hormone or prolactin in the granules. The nature of these cells remained obscure in this study. Since their incidence and fine structural features, other than the secretory granules, were quite similar to those of the growth hormone cells in normal rats, we postulate that these cells are dysfunctional growth hormone cells. These results suggest that the cause of the growth impairment in the spontaneous dwarf rat is due to a defect in the functional growth hormone cells in the pituitary gland, and since other pituitary cell types appeared normal, the disorder seems to be analogous to the isolated growth hormone deficiency in the human.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218859
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  • 4
    Electronic Resource
    Electronic Resource
    Accumulation of secretory granules in pituitary clonal cells derived from the epithelium of Rathke's pouch (1978)
    Springer
    Cell & tissue research 186 (1978), S. 53-61 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Clonal cells ; Secretory granules ; Rat serum ; in vitro studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 2A8 clonal cells derived from the epithelium of Rathke's pouch of the fetal rat are essentially agranular when grown in vitro, in spite of their active secretion of hormones, i.e., ACTH, prolactin and growth hormone. These cells do not produce detectable amounts of thyrotrophic or gonadotrophic hormones in vitro. When the growth medium (Ham's F10) was supplemented with rat median eminence extract (MEE), l-thyroxin and fresh serum from hypophysectomized rats, some of the 2A8 cells accumulated and stored secretory granules which were characteristic of the cells of the intact pituitary gland. Typical thyrotrophic and gonadotrophic cells also became recognizable and all six anterior pituitary hormones were released into the culture medium. Growth of 2A8 cells in this modified culture medium resulted in an increased production of all hormones with increasing time in culture. These results indicate that the processes that lead to the accumulation of typical mature secretory granules which characterize the individual pituitary cell types are initiated or promoted by some unidentified factor or factors which are present in fresh rat serum. It is also apparent that fresh rat serum can promote the differentiation of gonadotrophs and thyrotrophs in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219654
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  • 5
    Electronic Resource
    Electronic Resource
    Granular, ciliated cells in the anterior pituitaries of immature rats (1988)
    Springer
    Cell & tissue research 253 (1988), S. 683-684 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars anterior ; Cilia ; Differentiation ; Rat (Wistar-Imamichi)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In this communication we demonstrate a new type of ciliated cell in the pituitary gland of immature rats. Anterior pituitary glands of rats, 31 days of age, were examined by electron microscopy. Around the agranular cells, which lined small cavities, there were sparsely granulated cells with many cilia (granular, ciliated cells). Their small granules, which were distributed along the cell membrane, had limiting membranes. Their cilia were of 9+2 type with a central pair of micro tubules. It was suggested that the granular, ciliated cells might be an intermediate-type of cell for the different types of pituitary cells, which appear temporarily during pituitary ontogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219761
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  • 6
    Electronic Resource
    Electronic Resource
    Cystlike structures derived from the marginal cells of Rathke's cleft in rat pituitary grafts (1987)
    Springer
    Cell & tissue research 250 (1987), S. 29-33 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars anterior ; Cysts ; Transplantation ; Differentiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hemipituitary glands from 30 rats were isotransplanted under renal capsules. At 1, 2, 4, 7 and 20 days after transplantation, the grafts were examined by light and electron microscopy. Two days after transplantation, the central area of graft showed necrosis; however, the peripheral area, where marginal cells of Rathke's cleft were ingesting the remnants of necrotic glandular cells, survived. Four days after transplantation, mitotic figures of marginal cells were observed. Seven days after transplantation, the damaged area of the graft disappeared, and Rathke's cleft was completely lined by marginal cells. Remnants of necrotic glandular cells were not seen in intercellular spaces or in the cytoplasm of marginal cells. Cystlike structures formed in the grafts; some were connected to Rathke's cleft by narrow cavities. The cavity-lining cells of the cysts were agranular and similar to those that lined Rathke's cleft. At 20 days after transplantation, granular cavity-lining cells appeared. It is suggested that marginal cells of immature rats can differentiate into granular cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214650
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  • 7
    Electronic Resource
    Electronic Resource
    Separation and maturation of gonadotrophs from 2A8 clonal cells in vitro (1978)
    Springer
    Cell & tissue research 189 (1978), S. 31-40 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary cell clone ; LHRH-Sepharose ; Gonadotrophs ; Hypertrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 2A8 clonal cells derived from the epithelium of Rathke's pouch of fetal rats were cultured in growth medium supplemented with fresh rat serum, median-eminence extract and l-thyroxine. Then, in order to isolate gonadotrophs, cyanogen bromide-activated Sepharose which was conjugated with LHRH (LHRH-Sepharose) was added to the culture medium. Fourteen days after incubation of 2A8 cells with LHRH-Sepharose, agranular and granular cells were rapidly bound to LHRH-Sepharose when fresh serum had previously been added in the medium. The cytoplasm of granular cells that were bound to LHRH-Sepharose contained spherical secretory granules (200–250 nm in diameter). These cells were similar in morphology to the FSH and LH gonadotrophs described by Kurosumi (1968). Moreover, many of them appeared as hypertrophied cells that resembled “castration” cells. These results demonstrate that LHRH conjugated to Sepharose can be used to separate gonadotrophs from other 2A8 cells, and it is suggested that the hypertrophy of some cells might be due to persistent stimulation by LHRH which is likely bound to receptors on the cell membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223119
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  • 8
    Electronic Resource
    Electronic Resource
    Studies on the development of growth hormone and prolactin cells in the rat pituitary gland by in situ hybridization (1989)
    Springer
    Cell & tissue research 255 (1989), S. 23-28 
    Details
    ISSN: 1432-0878
    Keywords: Prolactin cells ; Growth hormone cells ; In situ hybridization ; Immunocytochemistry ; Cytogenesis ; Rat (Wistar-Imamichi)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytogenesis of growth hormone and prolactin cells in the rat pituitary gland was studied using in situ cDNA-mRNA hybridization and immunocytochemistry. Frozen or Paraplast sections of fetal and neonatal pituitaries were hybridized with 3H-cDNAs for rat prolactin or growth hormone, and were then processed for autoradiography. A number of growth hormone mRNA-positive cells were encountered throughout the anterior lobe on day 19 of gestation. Individual variaction in growth hormone gene expression was observed between fetuses at day 19 of gestation (6 out of 8 fetuses examined were positive for growth hormone mRNA). In contrast, growth hormone mRNA was detected in the all fetuses examined on day 20 or later. The autoradiographic signal (number of reduced silver grains) appeared to increase with later stages of development. Fetal growth hormone mRNA-positive cells were evenly scattered throughout the anterior lobe. Most of them were isolated, however, small clusters of several growth hormone cells were infrequently observed. Prolactin mRNApositive cells were found first on the 22nd day (the last day of gestation) in 3 of 6 fetuses examined, but were rarely observed on earlier gestational days. By postnatal day 8, prolactin mRNA-positive cells were numerous and the grain density over prolactin cells increased. Both growth hormone and prolactin cells were found as early as 18 days of gestation using immunocytochemistry, although the number of positive cells was very small at this stage. Immunoreactive growth hormone cells increased sharply in number during the next 24 h, while the number of prolactin cells remained scarce until birth. The results suggest that many growth hormone cells are still in an immature state at 20∶00 of day 18 and that many begin to synthesize growth hormone mRNA during next 14 h. On the other hand, no substantial prolactin gene expression appears to take place until after birth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229062
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  • 9
    Electronic Resource
    Electronic Resource
    Large-scale synthesis of Bi2Sr2CaCu2Ox superconducting whiskers (1997)
    Springer
    Journal of materials science 16 (1997), S. 1460-1463 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018594201947
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  • 10
    Electronic Resource
    Electronic Resource
    Preparation of In-plane Aligned Bi-2212Ag Tapes Using Bi- 2212 Whiskers (1998)
    Springer
    Journal of materials science 17 (1998), S. 981-983 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006649614478
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