Library

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
  • 1990-1994  (189)
  • 1960-1964
  • 1950-1954
  • 1880-1889
  • 1850-1859
  • 1993  (189)
  • 1
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 58 (1993), S. 520-522 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3013-3017 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Absorptive switching and transverse structures in resonatorless optical bistability in bulk ZnSe is observed upon exciting the sample at the Urbach edge. The switching is due to nonlinear absorption induced by a temperature tuning of the band gap. We have modeled such behavior by numerically solving for the intensity, carrier density, and temperature, including both longitudinal and transverse fluctuations. Simulations show that both longitudinal and transverse heat diffusion are necessary in producing specific structures, as well as in determining the time of switching. During switching, the experiment and theory illustrate for the intensity profile the formation of a local minima on axis (hole) followed by a local maxima on axis and local minima off axis (rings). Such beam distortions and bistable switching are the result of the spatial and temporal dynamics and positive feedback existing among the absorption and heating.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 9770-9775 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The first ab initio theoretical study has been performed on the ground state of nitroxide, HNO−, in combination with a comparison study of the ground state of two chemically similar systems, peroxy radical, HO2, and the neutral nitroxyl radical, HNO. An optimum geometry and vibrational frequencies are reported for all species, and results are compared to experimental and theoretical values. A bent geometry is obtained for HNO−, with an equilibrium bond angle of 106.2°, and bond lengths of RNO=1.333 A(ring) and RNH=1.045 A(ring). The calculated fundamental vibrational frequencies (in cm−1) are: ν1 (N–H stretch), 3029; ν2 (bend), 1474; and ν3 (N–O stretch), 1183. The bending frequency and the N–O stretching frequency in the ion are similar to the bending frequency and the O–O stretching frequency of HO2, while the N–H stretching frequency of HNO− is similar to the N–H stretching frequency of HNO. In addition, the GAUSSIAN 1 and GAUSSIAN 2 methods are used for the determination of an electron affinity for HNO. The calculated electron affinity of 0.23±0.10 eV is in reasonable agreement with the experimentally determined value of 0.338±0.015 eV.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 4937-4947 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Monte Carlo simulations were performed on lattice gas systems with Coulombic interactions. Emphasis was placed on two lattice gases. The first consists of both mobile anions and cations while the second is composed of mobile anions and a random distribution of fixed cations. Comparisons are made to a strictly repulsive lattice gas. The addition of attractive forces is shown to significantly retard particle motion relative to the repulsive system. In the mobile-anion, mobile-cation system, at temperatures high enough to suppress ion clustering, the effect of backward correlations on the particle diffusivity is found to be similar to that for the strictly repulsive system. In the mobile-anion, fixed-cation system, however, backward correlations are much stronger due to the presence of immobile Coulomb traps. Both systems deviate from Nernst–Einstein behavior. The mobile-anion, mobile-cation system exhibits diminished conductivity (Haven ratio (approximately-greater-than)1) due to the migration of neutral ion pairs, whereas the mobile-anion, fixed-cation system exhibits slightly enhanced conductivity (Haven ratio 〈1) due to the mutual repulsions between mobile charge carriers. The results of these simulations are discussed in terms of multiple timescale behavior, specifically including Funke's jump relaxation model, and observations on relaxation times are reported.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 3850-3865 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Collisional quenching cross sections for laser-induced fluorescence from NO A(v'=0) are measured for H2O, CO2, O2, NO, N2, H2, Ar, C2H6, and CO as a function of temperature from 300 to 1750 K. Room temperature cross sections vary widely (≤0.03 A(ring)2 for N2, H2, C2H6, and Ar to ≥100 A(ring)2 for H2O). As temperature increases, cross sections for H2O and CO2 decrease, cross sections for O2 and NO remain constant, and cross sections for N2, H2, CO, and C2H6 increase. These data provide quantitative quenching corrections for laser-induced fluorescence measurements of NO concentrations in nonreacting and reacting flows. Physical quenching models (based upon NO–Q and NO+–Q− collision complexes) are reviewed and used for experimental data correlation and extrapolation. A new quenching mechanism is proposed for weak quenchers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Sociological inquiry 63 (1993), S. 0 
    ISSN: 1475-682X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Sociology
    Notes: This study evaluates deviance among academicians in university settings. A typology is suggested which includes two dimensions and delineates four basic types of academic deviance. The relationship of these types to university and disciplinary organization is offered as the sources of academic deviance are explained.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 60 (1993), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Human tyrosine hydroxylase (HTH) RNA undergoes alternative splicing, and four different forms of HTH mRNA have been previously identified. Rabbit antibodies were raised against octapeptides unique to each of the four isoforms of HTH predicted from these mRNAs. Blot immunolabeling of human adrenal medulla, pheochromocytoma, and several neuroblastoma cell lines with affinitypurified anti-HTH peptide antibodies demonstrated the presence of all four HTH isoforms in each of these tissues. Quantitative immunolabeling assays for HTH-1, -2, and -4 were established, and HTH isoform levels were determined in several human neuroblastoma cell lines. Whereas total HTH levels differed up to fourfold among the HTH-positive neuroblastoma cell lines studied [LA-N-1, LA-N-5, CHP-234, BE(2)-C, and BE(2)-M17], the relative abundances of HTH isoforms in each of the cell lines were similar. Immunocytochemical analyses demonstrated that HTH immunoreactivity was distributed unequally among the cells in each of these neuroblastoma lines, and morphological interconversion did not account for this heterogeneity. A direct relationship between the percentage of HTH-positive cells and overall HTH levels was also observed. This relationship, in the absence of an apparent clonal basis for the heterogeneity, suggests that HTH expression in neuroblastoma cells may be controlled in a relatively “all-ornone”(bimodal) fashion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 61 (1993), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: A peptidylarginine deiminase (PAD; EC 3.5.3.15) has been isolated from bovine brain and some of its characteristics have been studied. The enzyme showed an absolute requirement for Ca2+, a temperature optimum at ∼50°C, and two Kmvalues when benzoylarginine ethyl ester was used as substrate, 0.78 mMand 11.2 mM.The higher Kmhas not been reported previously. Protein substrates for the enzyme included polyarginine and myelin basic protein but not histones. Because one of the components of MBP contains six citrullinyl residues per mole, enzymic deimination appeared to be a likely mechanism. When the most cationic component (C-1) was subjected to PAD in solution, 17 of the 19 arginyl residues were modified. From sequence analyses we concluded that the nature of the amino acid residues adjacent to the deiminated arginine were not modifiers of the reaction as arginyl residues in a variety of environments were deiminated. This deimination was reflected in a large increase in random structure, as measured by [θ]200. At 5°C, the [θ]200of the deiminated protein was -70 × 103 compared with -30 × 103 deg cm2/dmol for the native protein. When the temperature was increased to 70°C, the [θ]200 was -44 × 103 for the deiminated protein and -20 × 107 deg cm2/ dmol for the native C-1. When plotted as a function of temperature, [θ]200 decreased linearly from 5°C to 50°C for both proteins and did not change from 50°C to 70°C. PAD provides a mechanism for deimination of arginyl residues of myelin basic protein. The selective deimination of the six arginyl residues that are consistently found deiminated in C-8 may be determined by the orientation of the protein in the membrane and/or the more complex lipid composition of myelin may affect the selectivity of the deimination.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...