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  • 1
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chlamydomonas pulsatilla Wollenweber, a euryhaline, marine flagellate (isolated from rockpool at St. Andrew's, New Brunswick, Canada in 1980 by J. A. Hellebust), shows decreasing rates of activity of its four contractile vacuoles in the salinity range of 0 to 15% artificial seawater (ASW). Electron microscopy shows that the contractile vacuole complex persists as a spongiome (collection of small vesicles or tubules) in cells grown at salinities above the range for operation of contractile vacuoles. From calculations of rates of water expulsion, based on size and frequency of contraction of individual vacuoles determined by light microscopy, the time necessary to empty one cell volume increased from ca 20 min at 1% ASW to ca 600 min at 15% ASW. Analysis of inorganic and organic solute contents of cells grown at 1 and 5% ASW allowed the calculation of internal osmotic pressures. Estimates of hydraulic conductivities based on rates of water expulsion via contractile vacuoles and differences in internal and external osmotic pressures resulted in values ranging from 1.1 to 1.4×10-14 m s-1 Pa-1 for individual cells. Growth experiments at low photon flux densities over a salinity range of 1 to 15% ASW, over which contractile vacuole activity varied by a factor of 30, showed little difference in growth rates. This indicates that the cost for operation of contractile vacuoles must be very low. The secretion of large molecular weight organic substances does not appear to be associated with the functioning of contractile vacuoles.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chlorella autotrophica Shihira and Krauss (clone 580), a euryhaline microalga from the marine coastal environment is subject to large fluctuations in external salinity and nitrogen supply. The alga exhibits maximum growth at salinities lower than 100% ASW (artificial seawater). Cells divide faster and show higher cell yields when the supply of either NH 4 + or NO 3 - is increased above 0.2 mM. Cells growing on NH 4 + show high levels of NADPH-glutamate dehydrogenase (GDH) activity, and the levels of glutamine synthetase (GS) are decreased to very low levels under these conditions. Methionine sulfoximine (MSX), an inhibitor of GS, has little effect on cell division and nitrogen assimilation of cells growing on NH 4 + . Cells growing on NO 3 - , however, show marked inhibition (65%) in nitrogen assimilation in the presence of 5 mM MSX. This MSX concentration also causes growth retardation and a progressive decrease in cell protein and nitrogen content. GS is almost completely inhibited by 5 mM MSX in both NH 4 + and NO 3 - -grown cells. Cells growing on NH 4 + maintain high levels of NADPH-GDH activity in the presence of MSX. NADPH-GDH activity in MSX-treated NO 3 - -grown cells increases, and, in the presence of 5 mM MSX, reaches 40% of the level found in NH 4 + -grown cells. These results are consistent with NADPH-GDH providing an alternate pathway for NH 4 + assimilation by this marine Chlorella species.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 87 (1985), S. 245-250 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Brachiomonas submarina Bohlin (Chlorophyceae), a euryhaline marine flagellate, can osmoregulate over a wide range of external salinity. The alga exhibits maximum water content at 100% artificial seawater (ASW), and shows only a small water loss (〈15%) when salinity is increased to 300% ASW. The non-aqueous volume of the cells is increased at salinities higher than 100% ASW. This is partially attributable to the accumulation of glycerol. Glycerol is the major osmoregulatory organic solute in this flagellate. The alga also shows an accumulation of amino acids in response to increased salinity. The contribution of glycerol and amino acids to intracellular osmolarity is only 9% at 10% ASW, but accounts for 49% at 300% ASW. The remainder of the osmotic balance is due to uptake and accumulation of inorganic ions, particularly sodium, potassium and chloride.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of environmental contamination and toxicology 61 (1998), S. 746-753 
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 31 (Nov. 2007), p. 202-205 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Nowadays, die attach film (DAF) gaining popularity in microelectronic packaging asintegral part in facilitating the growth of wafer level packaging and stacked die packaging. DAFapplied to the backside of wafers prior to saw have many advantages, such as the elimination of theepoxy dispensed process step and the reduction of epoxy related failure mode. However, the dicingprocess for DAF wafer usually associated with sidewall chipping, DAF whiskering and crack thatwill affect reliability of Quad Flat Non-Leaded (QFN) stacked die. Blade properties andcharacteristics are the crucial factor in analyzing the DAF dicing results. In this paper, we evaluatethe blade characteristics before and after DAF wafer dicing process for our stacked die packaging.The qualitative measure by means of the Scanning Electron Microscope (SEM) and EnergyDispersive X-Ray (EDX) analysis were performed in order to understand the lamination and dullingeffect on blade surface. The obtained results showed that sawing polymeric material such as waferlaminated with DAF induces lamination of polymeric material onto the blade surface and reduceblade cutting edge. As a result, reduce the quality of DAF dicing process
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0942-0940
    Keywords: Calcitonin gene-related peptide ; slow-release tablet ; subarachnoid haemorrhage ; cerebral vasospasm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The calcitonin gene-related peptide (CGRP), a known potent intrinsic cerebral vasodilator, is contained in the sensory nerves from trigeminal ganglia that inervate the cerebral arteries. We previously reported that human α CGRP (hCGRP) dilates spastic cerebral arteries after experimental subarachnoid haemorrhage (SAH) in rabbits. In the present study, we investigated the prophylactic potential of a sustained higher cerebrospinal fluid level ofhCGRP against experimental cerebral vasospasm. AnhCGRP slow-release tablet (hCGRP s-r tablet) was developed for cisternal implantation. Experimental SAH was induced by percutaneous cisternal injection of autologous arterial blood. Angiography was initiated on day 1 (before SAH) and performed everyday. ThehCGRP s-r tablet was implanted into the cisterna magna on day 2 in the treated groups. The spastic response of the basilar artery was maximized on day 4 in the non-treated (80.7% of day 1) and the placebo-treated (79.3%) groups. In contrast, the arterial diameters on day 4 were 96.1% and 90.5% of day 1 in the groups implanted withhCGRP 24 μg and 153 μg s-r tablets, respectively. We also measured the concentration ofhCGRP in the cerebrospinal fluid (CSF) following implantation of thehCGRP 24 μg s-r tablet in the cisterna magna. The hCGRP concentration before implantation was below the dectable level. Following implantation, thehCGRP level in the CSF was 23.12 nmol/L on the second day and remained at elevated levels until the fifth day. These experiments suggest that the intrathecal single implantation of thehCGRP s-r tablet could produce an elevated concentration ofhCGRP in the CSF over five days and have prevented the cerebral vasospasm after SAH in the rabbit. ThehCGRP s-r tablet may be clinically applicable in the treatment of patients with SAH against cerebral vasospasm.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 518 (July 2006), p. 477-484 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Amorphous carbon coatings for implantable medical devices require high mechanicalstrength, adhesion and uniform biocompatibility response across the devices. Investigation of a-C:Hproperties and structure variation with thickness and substrate material provides valuable insightinto requirements for device coating. A number of devices are coated and the effect of interfaciallayers, film doping and the spatial variation in quality is investigated
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 173 (1990), S. 463-470 
    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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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 173 (1990), S. 463-470 
    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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  • 10
    ISSN: 0375-9474
    Keywords: Nuclear Reactions
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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