ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Collection
Keywords
Publisher
Language
Years
  • 1
    Electronic Resource
    Electronic Resource
    Acid and alkaline phosphatase activities in the clam Ruditapes philippinarum (1993)
    Springer
    Marine biology 115 (1993), S. 113-118 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acid and alkaline phosphatase activities have been partially characterized in Ruditapes philippinarum (Adams and Reeve, 1850). Two activity peaks at pH=4.5 and pH 10.5 were detected in the gill, digestive gland, mantle, siphon and foot. Acid phosphatase activity was higher than that of alkaline phosphatase. The highest activity for both enzymes was observed in the digestive gland and, in decreasing order, the gill, foot, siphon and mantle. Alkaline phosphatase activity was similar in the mantle, siphon and foot. K m values were determined for both enzymes in the gill and digestive gland. Hill coefficients were near 1, indicating no allosteric behaviour for either enzyme in the two organs. The optimum temperature was the same for acid phosphatase in both gill and digestive gland (50 °C), while for alkaline phosphatase it differed for these two organs (gill, 40 °C; digestive gland, 35 °C). The apparent activation energy was obtained from Arrhenius plots, and ranged from 8.61 kcal/mol for alkaline phosphatase in the gill, to 10.84 kcal/mol for acid phosphatase in the digestive gland. The effects of metals (1 mM conc) on both enzyme activities were assayed in vitro. Hg strongly inhibited the enzyme activities in the gill and digestive gland, probably because of its affinity for the sulphydryl group. Histochemically, acid phosphatase in the gill was located in a granular form throughout the gill cells, but was undetectable in the ciliate epithelium of the gill filaments. Alkaline phosphatase was located in the gill skeleton. Clam size and phosphatase activities were inversely related, probably reflecting a decrease in shell deposition with inereasing size. As a function of season, both enzymes were present in lowest amounts in winter, when undifferentiated sex cells were predominant in the germinative epithelium, and highest in summer, when ripe individuals of both sexes were more frequent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349392
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Non-linearity of the YBa"2Cu"3O"7"-"δ low field diamagnetic properties: Multi-harmonic analysis.
    Amsterdam : Elsevier
    Physica C: Superconductivity and its applications 162-164 (1989), S. 325-326 
    Details
    ISSN: 0921-4534
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0921-4534(89)91037-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Biochemical characteristics of aspartate aminotransferase from gills and digestive gland of the manile clam (Ruditapes philippinarum)
    Amsterdam : Elsevier
    Comparative Biochemistry and Physiology -- Part B: Biochemistry and 103 (1992), S. 209-216 
    Details
    ISSN: 0305-0491
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0305-0491(92)90433-R
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Structural, magnetic and electrical properties of NdNi"1"-"xFe"xO"3 and NdNi"1"-"xCo"xO"3 systems
    Amsterdam : Elsevier
    Journal of Physics and Chemistry of Solids 55 (1994), S. 843-852 
    Details
    ISSN: 0022-3697
    Keywords: A. oxides ; C. X-ray diffraction ; D. electrical properties ; D. magnetic properties
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-3697(94)90009-4
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Correlation between magnetovolume and giant magnetoresistance effects in doped La2/3Ca1/3MnO3 perovskites : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5175-5177 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: La0.62Tb0.05Ca0.33MnO3 and La0.6Y0.07Ca0.33MnO3 have been studied in order to probe into the mechanisms responsible for the giant magnetoresistance ratios observed in this kind of compound. The experiments have shown a strong connection between the magnetotransport and magnetovolume properties. A large volume effect appears above Tc which collapses with applied magnetic field or when the long range magnetic order sets in. Above Tc the magnetostriction and magnetoresistance isotherms are highly correlated. Charge localization with local distortion appears to be responsible for the transport and volume properties at zero field. Charge mobility and a more normal volume dependence on temperature are restored by applying high enough magnetic fields. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361544
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Pressure effect on the resistivity in GMR La0.60Y0.07Ca0.33MnO3 compound (abstract) : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5178-5178 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The substitution of La+3 by smaller Y+3 ions in mixed valence Mn+3–Mn+4 perovskites La0.67−xYxCa0.33MnO3 gives rise to a decrease of the order temperature (Tc=160±5 K for x=0.07 and Tc=240 K for x=0). One of the most relevant features found in this compound was the extremely large magnetoresistance observed in bulk polycrystals (≈−10 000%) near Tc. This huge effect was associated with the reduction of the lattice parameter. In order to have an insight into the influence of volume change on transport properties in this compound, we have performed measurement of the thermal dependence of the resistivity under hydrostatic pressure up to 8 kbar. At ambient pressure a peaklike anomaly in the resistivity is observed at Tc. Under the former assumptions, one would expect an increase of the resistivity value at the maximum as well as a decrease of Tc. However, we have found a shift toward higher temperatures and a drastic decreasing of the maximum in the resistivity for increasing pressures. At a pressure of 7.5 kbar the anomaly in the resistivity almost disappears and consequently the GMR effect. As a consequence, the effect of pressure seems to be identical to the effect of the applied magnetic field. Ibarra et al. recently observed a large spontaneous magnetovolume effect at Tc with an extra contribution to the lattice thermal expansion. This extra contribution was found to be suppressed by an applied magnetic field. From these preliminary results it seems that the interplay between magnetostrictive deformations and the shrinkage of the lattice by external pressure could be in the origin of the observed behavior. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361330
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The effects of starvation and refeeding on plasma amino acid levels in carp, Cyprinus carpio L., 1758 (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 38 (1991), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Plasma amino acid (AA) levels of carp, Cyprinus carpio L., 1758, were analysed after various periods of starvation as well as after 12 days of refeeding. The levels were compared to control groups, which had been previously fasted for 24 h. A positive correlation between dietary and plasma essential amino acid (EAA) concentrations was observed in all of the control groups.The effect of starvation on the dynamics of AA concentration was different according to the period of starvation. Fasting already produced a decrease of total α-AA levels at 2 days, and these low levels were maintained until 5 and 8 days. These short periods of fasting affected the levels of EAA (especially branched-chain AA) more than those of non-essential amino acids (NEAA). The only AA that increased was Ala, which rose at 5 days of starvation, surpassing the levels of the control group. These high levels were maintained until 19 days of starvation.A different situation was observed at 19 days, when an important increase of total α-AA levels was produced, the branched-chain AA being the most notable among EAA and Glu/Gln among NEAA. Later, at 50 days of starvation, total α-AA, EAA (except Leu and Ile) and NEAA decreased.After 50 days of starvation, 12 days of refeeding did not modify the levels of EAA and NEAA, and their concentrations were lower than those of the control group, which presented an increase of total AA at this time. The differences observed on the changes of individual AA levels are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1991.tb03145.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Thermal expansion and magnetostriction in colossal magnetoresistance mixed valence manganites (abstract) : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 5504-5504 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Structural aspects are closely related to the large spontaneous and field-induced magnetic and magnetogalvanic effects in mixed valence manganites. Local distortions are the source of an extra contribution to the thermal expansion. These were associated with a charge localization process.1 The existence of ferromagnetic order in these compounds favors the carriers mobility and, as a consequence, produces unexpected magnetovolume effects.2 We report thermal expansion measurements within the temperature range 4–800 K and magnetostriction up to 15 T in the series (R1−yRy)1−xCaxMnO3 (R=La, Nd and R′=Y, Tb). We have found completely unusual volume magnetostriction at temperatures at which the system is in the insulator state (paramagnetic, antiferromagnetic, spin-glass states). These results give a deep insight into the mechanism responsible for the colossal magnetoresistance and reveal these experimental techniques as an excellent tool to follow the spontaneous and field-induced localization and delocalization processes. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Pressure effect on yttrium doped La0.60Y0.07Ca0.33MnO3 compound (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 67 (1995), S. 2875-2877 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the effect of hydrostatic pressure up to 8 kbar on magnetoelastic, magnetic, and transport properties in the temperature range 10–300 K. An increase of Curie temperature Tc with pressure ΔTc/Δp=2.6 K/kbar was determined from ac susceptibility measurements. The anomalies in resistivity and magnetovolume effects are significantly suppressed by pressure but the temperatures of these anomalies increased with pressure with the same slope as Tc. These results indicate that impurity state of yttrium rather than lattice parameter reduction is responsible for the large increase in the magnetoresistance observed in the doped compound. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.114814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Variations in tissue reserves, plasma metabolites and pancreatic hormones during fasting in immature carp (Cyprinus carpio)
    Amsterdam : Elsevier
    Comparative Biochemistry and Physiology -- Part A: Physiology 103 (1992), S. 357-363 
    Details
    ISSN: 0300-9629
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0300-9629(92)90594-G
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...