Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Computational Chemistry and Molecular Modeling  (21)
  • Long-range order  (2)
  • Cell & Developmental Biology  (1)
  • Conjugation  (1)
  • 1
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The expression of laminin, a major constituent of endometrial cell basement membranes, is increased during differentiation of human endometrial stromal cells (decidualization). To determine whether laminin plays a role in decidualization, we studied the effects of laminin substrate on the synthesis and release of prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1), two major secretory proteins of decidualized stromal cells. Endometrial stromal cells were plated on laminin as well as several other extracellular matrix (ECM) proteins (types 1 and IV collagen or fibronectin) and on plastic, and cultured in media containing medroxyprogesterone acetate (MPA) and estradiol. Cells cultured on plastic or ECM proteins displayed similar morphological changes indicative of decidualization. However, the release of PRL and IGFBP-1 from cells cultured on plastic and ECM proteins (types 1 and IV collagen and fibronection) was approximately 2.1-fold and 2.8-fold greater respectively, than from cells cultured on laminin. The decrease in PRL and IGFBP-1 expression in cells cultured on laminin was not due to differences in initial cell attachment efficiency or final DNA content. In addition, laminin had no effect on the content of laminin protein or fibronectin mRNA levels, indicating that the effects of laminin on PRL and IGFBP-1 were specific. PGE2 stimulated the release of PRL and IGFBP-1 from cells cultured on laminin to levels comparable to those from cells cultured on plastic or other ECM proteins. This indicates that the decrease in PRL and IGFBP-1 release by laminin was not due to a generalized unresponsiveness. In contrast to the effects of laminin during decidualization, PRL expression was not altered by laminin in terminally differentiated decidual cells isolated at term. Our results support a role for laminin in selectively regulating PRL and IGFBP-1 gene expression during in vitro decidualization of human endometrial stromal cells. © 1995 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various earlier-proposed perturbative approaches to the description of weakly interacting species are considered. It is argued that most of these perturbative approaches, including many of the so-called exchange perturbation theories, exhibit a number of difficulties and limitations, which have not previously been emphasized. From these criticisms positive suggestions as to the nature of a general exchange perturbation-like theory are made. Finally, a candidate for such a theory is outlined.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Symmetries are considered for a class of Hamiltonian models with one (spin-free) orbital per site. The models include common types of Parisier-Parr-Pople and valence-bond Hamiltonians, defined over a continuous range of parametrizations. The symmetries investigated are linear canonical transformations and include the common point-group and alternancy symmetries. We find “graphical” symmetries extending the usual point-group symmetries and novel “color-pairing” symmetries which involve hybrids of point-group-like and alternancy symmetries of relevance for certain heteroatomic species. The occurence of recolorpairing transformations relating the eigensolutions of models for different molecules is also noted.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Within the framework of the AMO-EHF approximation for the Hubbard model, it is shown that the band gap ΔE of an arbitrary regular alternant 1D π-system (polymer), having a singlet ground state, is different from zero, i.e., the ground state is a dielectric one. At least one of the three components of the energy gap - the topological, Δtop; the geometrical, Δgeom; or the correlation, Δcorr (combined via the equation ΔE = {Δcorr2 + (Δtop + Δgeom))2}1/2 - is different from zero. Numerical results for several 1D alternant polymers with conjugated π-systems are given. © 1994 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 12 (1991), S. 1243-1251 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A chemically and graph-theoretically relevant problem is that of determining whether a pair of graphs G and G′ are isomorphic. A two-stage computational test is developed. In the first stage an “eigenvalue-eigenprojector” tabular graph-theoretic invariant is computed, whence if the two tables differ, G and G′ must be nonisomorphic. The second stage, utilizing the tables of the first stage, orders the vertices, thereby leading to a special labeling for them, whence if the associated adjacency matrices for G and G′ are equal, it must be that G and G′ are isomorphic. The computational implementation, and testing of the algorithm is described.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 16 (1995), S. 517-526 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We consider rigorous evaluation of conjugated-circuit resonance energies for families of structurally related benzenoid hydrocarbons of increasing size. Local and global aromatic properties of such molecules are investigated with particular interest in modeling high polymers. Using the algebra of large numbers, exact formulas for contributions from individual benzene rings of polymers with up to 25,000 repeating units (close to half a million carbon atoms) were derived. All arithmetic procedures were carried out in terms of whole numbers retaining all digits, of which there were sometimes more than 105. © 1995 by John Wiley & Sons, Inc.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 12 (1991), S. 1252-1259 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The problem of the generation of polyhedra with degree-3 vertices, and faces each of which is pentagonal or hexagonal, is addressed in order to characterize carbon in order to characterize clusters of ca. 30 or more atoms. Following Eulerian type arguments such polyhedra are subcategorized in terms of numbers of different types of local structures. An algorithm to generate such polyhedra is developed, and its computer implementation is described. Results for smaller than 80-vertex cages of subcategories anticipated to be more chemically relevant are reported. The singular position of the truncated-icosahedron (buckminsterfullerene) structure is noted.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 12 (1991), S. 1260-1264 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A powerful algorithm for calculating conjugated-circuit expectations for planar graphs is enunicated. The utility for systematizing quantitative resonance-theoretic computations on conjugated hydrocarbons, and related species, is emphasized.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 12 (1991), S. 1265-1269 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The enumeration of all 60-atom carbon cages associated to trivalent polyhedra with five-and six-sided faces is addressed. This isomer problem is computationally solved to give 1790 cages, with a further resolution into subclasses of cages with differing numbers p of abutting pairs of pentagonal faces. The individual cages are generated, and then there are computed various graph-theoretic invariants, including Hückel MO energies, HOMO-LUMO gaps, Kekulé structure counts, and conjugated-circuit counts. Associated properties as a function of p are reported and found to be in concert with earlier qualitative arguments. It is found that the most stable of these cages is the unqiue p = 0 Buckminsterfullerene structure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A frequently encountered problem in chemical applications is that of a weighted enumeration (or summation over) a class of extended subgraphs of a given system graph, which might represent a chemical structure. Some aspects of a powerful transfer-matrix method are described for treating such graphtheoretic weighted enumeration problems. This method is seen to be particularly amenable for system graphs which are long in one direction and narrow in transverse directions. When the system graph is uniform (i.e., translationally symmetric) along one extended direction, asymptotic results can be readily extracted.A second point of emphasis here is that the weighted enumeration problems of the type studied here naturally arise in computing matrix elements over cluster expanded wave functions, though most applications so far framed in the literature differ from this. Size consistency and size-extensivity aspects of this application are noted in terms of the transfer-matrix approach.Polypyrene fusene strips of varying lengths are considered as applications of the transfer-matrix methods for two weighted enumeration problems. Different graph-theoretic problems are noted to arise for low-order cluster expanded wave functions, such as in fact occur in both the Herndon-Simpson and the Pauling-Wheland resonance theories. For higher-order wave function ansätze the graph-theoretic problems would simply have more complicated weights and transfer matrices, which for the present examples are very small (i.e., 2 by 2 and 3 by 3).
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...