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  • 1
    Electronic Resource
    Electronic Resource
    Au-Sn/W and Au-Sn/Cr metallized chemical vapor deposited diamond heat sinks for InP laser device applications (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 563-567 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An attempt to apply a more stable metallurgical soldering system than the traditionally used Ti/Pt/Au-Sn reactive system was explored by replacing the barrier metals in between the chemical vapor deposited diamond (CVDD) submount and the Au-Sn solder with either W or Cr layers. In the case of the W layer a thin layer of Ti was added to improve the adhesion of Au-Sn solder to the W layer. The CVDD/W(100 nm)/Ti(10 nm)/Au-Sn(1.5–2.2 μm) system was heat treated at 350 °C for durations of 5 s–5 min, simulating a bonding cycle, and the metallurgical interactions were analyzed. Some diffusion of the Ti was observed, but the W layer remained intact. Thus, due to the absence of interaction between the Sn or Au and the W barrier layer, the Au:Sn ratio was kept uniform for long duration heating ((approximately-greater-than)2 min). The Au-Sn solder tends to "ball up'' in local spots leading to the formation of local voids in the continuous solder layer over the W. In the case of the CVDD/Ti (100 nm)/Cr(200 nm)/AuSn(1.5–2.2 μm) structure a minimum interaction between the Au-Sn solder and the barrier was observed through a heating cycle at 350 °C for 5 min. This heat treatment, however, led to solder surface roughness in the order of about 5000 A(ring) between bump peak and valley, but the Au:Sn composition remained in the eutectic ratio of 70:30 at. %. Both soldering metallurgical systems gave a potential good bonding of InP laser diodes to CVDD heat sinks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355840
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  • 2
    Electronic Resource
    Electronic Resource
    Infantile fibrosarcoma: radiological and clinical features (1994)
    Springer
    Skeletal radiology 23 (1994), S. 337-341 
    Details
    ISSN: 1432-2161
    Keywords: Infantile Fibrosarcoma ; Computed tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two cases of infantile fibrosarcoma are described. This rare childhood malignancy of mesodermal origin usually affects the lower limbs, as it did in both of our cases. Previously, the only treatment option available involved some form of radical and often mutilating surgery. More recently, combination chemotherapy has given good results, with the effect that various imaging modalities have become important in assessing both the initial extent of disease and the response to treatment. Computed tomography has the advantage of demonstrating the amount of osseous involvement, but at the expense of a considerable dose of ionizing radiation. On the other hand, magnetic resonance imaging, with its multiplanar capacity, gives superior demonstration of breaching of tissue planes, which has important implications for planning of surgery. However, as in other soft tissue tumours, changes in signal characteristics with treatment have proved less specific than was originally anticipated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02416988
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  • 3
    Electronic Resource
    Electronic Resource
    Isolated dihydroxyacetonephosphate acyltransferase deficiency presenting with developmental delay (1994)
    Springer
    Journal of inherited metabolic disease 17 (1994), S. 533-540 
    Details
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A boy aged 21 months who was being investigated for developmental delay and failure to thrive was found to have punctate epiphyseal calcification. He had no evidence of rhizomelic shortening of the limbs or cataracts. Investigation revealed defective plasmalogen synthesis due to isolated deficiency of dihydroxyacetonephosphate acyltransferase (DHAP-AT). The parents were consanguineous and a sister was similarly affected, suggesting autosomal recessive inheritance. Hitherto, recessively inherited isolated DHAP-AT deficiency has only been described in patients with a phenotype similar to that of rhizomelic chondrodysplasia punctata. This report indicates that the same biochemical disorder can be associated with a less severe phenotype.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711587
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  • 4
    Electronic Resource
    Electronic Resource
    Developmental expression of poly(A) binding protein mRNAs during spermatogenesis in the mouse (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 39 (1994), S. 355-364 
    Details
    ISSN: 1040-452X
    Keywords: Testis-specific ; Spermatid ; Spermatocyte ; Poly (A) binding protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The poly(A) binding protein (PABP), a conserved protein that binds to the 3′ poly(A) tail on mRNAs in eukaryotic cells, has been implicated in the regulation of mRNA stability and translation. Two PABP cDNAs with different sequences were isolated from mouse testis cDNA libraries. The predicted amino acid sequence of one, PABP1, is nearly identical (98.9%) to human liver PABP, while 80% of the amino acids of the second, PABPt, are identical to mouse and human PABPs. Northern blots reveal that there is one major PABP mRNA species in liver, muscle, kidney, and brain, two in spleen, and at least four in testis. The levels of PABP mRNA in testis are 5-10-fold higher than in these somatic tissues, but surprisingly the vast majority of all PABP mRNA size variants sediment more slowly than single ribosome, indicating strong translational repression. Reverse transcriptase-polymerase chain reaction assays demonstrate that PABPt mRNAs are abundant only in testis. Northern blots of RNAs purified from highly enriched spermatogenic cells show that the high levels, multiple sizes of PABP mRNAs, and the PABPt mRNA are present in meiotic and early haploid spermatogenic cells, and are sharply reduced in late haploid cells. Comparison of the binding of PABP1 and PABPt to poly(A) Sepharose in vitro revealed subtle differences, even though PABPt contains substitutions for highly conserved aromatic amino acids that are thought to be necessary for binding to poly(A). The existence of two PABP isoforms in mouse spermatogenic cells could influence cytoplasmic gene expression during spermatogenesis. © 1994 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080390403
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  • 5
    Electronic Resource
    Electronic Resource
    Striking selectivity of anion incorporation into polypyrrole by competitive doping: perchlorate versus hexafluorophosphate (1994)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 5 (1994), S. 586-590 
    Details
    ISSN: 1042-7147
    Keywords: Conducting polymer ; Polypyrrole ; Competitive doping ; Anion selectivity ; Perchlorate ; Hexafluorophosphate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In the electro-oxidative preparation of polypyrrole films from electrolyte media containing both perchlorate and hexafluorophosphate anions a striking selectivity towards ClO4 was observed, with a three-fold preference for this anion in films from aqueous medium and a greater than ten-fold preference from MeCN. This result is of benefit towards the production of polypyrroles containing complex functionalized dopant anions, since the presence of PF6 to bolster electrolysis parameters will less readily carry over into the final polymer. PF6 is particularly useful for this purpose in MeCN, where ClO4 is inappropriate, being itself too readily incorporated into the polymer from this solvent system.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1994.220050920
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