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  1. Article ; Online: The 2008 Financial Recession and the Dodd-Frank Act

    Spano Dominick

    Holistica, Vol 12, Iss 1, Pp 1-

    2021  Volume 10

    Abstract: ... this paper, readers will also learn about the demographics effected by the recession and the Dodd-Frank Act ...

    Abstract The 2008 Financial Recession was one of the most significant fiscal downturns in the history of the United States. Considering that the world is in the midst of a global pandemic which may lead to another adverse economic climate, I believe that looking back at the causes of the 2008 Financial Recession is recommended. This may assist administrators to avoid the missteps which sparked this down economy in the future. By reading this paper, readers will also learn about the demographics effected by the recession and the Dodd-Frank Act, which was drafted to combat future occurrences of this nature.
    Keywords recession ; dodd-frank act ; obama ; regulations ; policy ; Social sciences (General) ; H1-99
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher Sciendo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Exciton-phonon polaritons in organic microcavities: Testing a simple ansatz for treating a large number of chromophores.

    Spano, Frank C

    The Journal of chemical physics

    2020  Volume 152, Issue 20, Page(s) 204113

    Abstract: Polaritons in an ensemble of permutationally symmetric chromophores confined to an optical microcavity are investigated numerically. The analysis is based on the Holstein-Tavis-Cummings Hamiltonian which accounts for the coupling between an electronic ... ...

    Abstract Polaritons in an ensemble of permutationally symmetric chromophores confined to an optical microcavity are investigated numerically. The analysis is based on the Holstein-Tavis-Cummings Hamiltonian which accounts for the coupling between an electronic excitation on each chromophore and a single cavity mode, as well as the coupling between the electronic and nuclear degrees of freedom on each chromophore. A straightforward ensemble partitioning scheme is introduced, which, along with an intuitive ansatz, allows one to obtain accurate evaluations of the lowest-energy polaritons using a subset of collective states. The polaritons include all three degrees of freedom-electronic, vibronic, and photonic-and can therefore be described as exciton-phonon polaritons. Applications focus on the limiting regimes where the Rabi frequency is small or large compared to the nuclear relaxation energy subsequent to optical excitation, with relaxation occurring mainly along the vinyl stretching coordinate in conjugated organic chromophores. Comparisons are also made to the more conventional vibronic polariton approach, which does not take into account two-particle excitations and vibration-photon states.
    Language English
    Publishing date 2020-06-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/5.0002164
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Erratum: "HJ-aggregates of donor-acceptor-donor oligomers and polymers" [J. Chem. Phys. 155, 034905 (2021)].

    Chang, Xin / Qarai, Mohammad Balooch / Spano, Frank C

    The Journal of chemical physics

    2022  Volume 157, Issue 20, Page(s) 209901

    Language English
    Publishing date 2022-12-01
    Publishing country United States
    Document type Journal Article ; Published Erratum
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/5.0133010
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Excitons and Polarons in Organic Materials.

    Ghosh, Raja / Spano, Frank C

    Accounts of chemical research

    2020  Volume 53, Issue 10, Page(s) 2201–2211

    Abstract: ConspectusExcitons and polarons play a central role in the electronic and optical properties of organic semiconducting polymers and molecular aggregates and are of fundamental importance in understanding the operation of organic optoelectronic devices ... ...

    Abstract ConspectusExcitons and polarons play a central role in the electronic and optical properties of organic semiconducting polymers and molecular aggregates and are of fundamental importance in understanding the operation of organic optoelectronic devices such as solar cells and light-emitting diodes. For many conjugated organic molecules and polymers, the creation of neutral electronic excitations or ionic radicals is associated with significant nuclear relaxation, the bulk of which occurs along the vinyl-stretching mode or the aromatic-quinoidal stretching mode when conjugated rings are present. Within a polymer chain or molecular aggregate, nuclear relaxation competes with energy- and charge-transfer, mediated by electronic interactions between the constituent units (repeat units for polymers and individual chromophores for a molecular aggregate); for neutral electronic excitations, such inter-unit interactions lead to extended excited states or excitons, while for positive (or negative) charges, interactions lead to delocalized hole (or electron) polarons. The electronic coupling as well as the local coupling between electronic and nuclear degrees of freedom in both excitons and polarons can be described with a Holstein Hamiltonian. However, although excitons and polarons derive from similarly structured Hamiltonians, their optical signatures are quite distinct, largely due to differing ground states and optical selection rules.In this Account, we explore the similarities and differences in the spectral response of excitons and polarons in organic polymers and molecular aggregates. We limit our analysis to the subspace of excitons and hole polarons containing at most one excitation; hence we omit the influence of bipolarons, biexcitons, and higher multiparticle excitations. Using a generic linear array of coupled units as a model host for both excitons and polarons, we compare and contrast the optical responses of both quasiparticles, with a particular emphasis on the spatial coherence length, the length over which an exciton or polaron possesses wave-like properties important for more efficient transport. For excitons, the UV-vis absorption spectrum is generally represented by a distorted vibronic progression with H-like or J-like signatures depending on the sign of the electronic coupling,
    Language English
    Publishing date 2020-10-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1483291-4
    ISSN 1520-4898 ; 0001-4842
    ISSN (online) 1520-4898
    ISSN 0001-4842
    DOI 10.1021/acs.accounts.0c00349
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Polaron absorption in aligned conjugated polymer films: breakdown of adiabatic treatments and going beyond the conventional mid-gap state model.

    LeCroy, Garrett / Ghosh, Raja / Untilova, Viktoriia / Guio, Lorenzo / Stone, Kevin H / Brinkmann, Martin / Luscombe, Christine / Spano, Frank C / Salleo, Alberto

    Materials horizons

    2024  Volume 11, Issue 2, Page(s) 545–553

    Abstract: This study provides the first experimental polarized intermolecular and intramolecular optical absorption components of field-induced polarons in regioregular poly(3-hexylthiophene-2,5-diyl), rr-P3HT, a polymer semiconductor. Highly aligned rr-P3HT thin ... ...

    Abstract This study provides the first experimental polarized intermolecular and intramolecular optical absorption components of field-induced polarons in regioregular poly(3-hexylthiophene-2,5-diyl), rr-P3HT, a polymer semiconductor. Highly aligned rr-P3HT thin films were prepared by a high temperature shear-alignment process that orients polymer backbones along the shearing direction. rr-P3HT in-plane molecular orientation was measured by electron diffraction, and out-of-plane orientation was measured through series of synchrotron X-ray scattering techniques. Then, with molecular orientation quantified, polarized charge modulation spectroscopy was used to probe mid-IR polaron absorption in the
    Language English
    Publishing date 2024-01-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 2744250-0
    ISSN 2051-6355 ; 2051-6347
    ISSN (online) 2051-6355
    ISSN 2051-6347
    DOI 10.1039/d3mh01278f
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: HJ-aggregates of donor-acceptor-donor oligomers and polymers.

    Chang, Xin / Balooch Qarai, Mohammad / Spano, Frank C

    The Journal of chemical physics

    2021  Volume 155, Issue 3, Page(s) 34905

    Abstract: A vibronic exciton model is developed to account for the spectral signatures of HJ-aggregates of oligomers and polymers containing donor-acceptor-donor (DAD) repeat units. In (DAD) ...

    Abstract A vibronic exciton model is developed to account for the spectral signatures of HJ-aggregates of oligomers and polymers containing donor-acceptor-donor (DAD) repeat units. In (DAD)
    Language English
    Publishing date 2021-07-23
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/5.0054877
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: A Holstein–Peierls Approach to Excimer Spectra: The Evolution from Vibronically Structured to Unstructured Emission

    Bialas, April L. / Spano, Frank C.

    Journal of physical chemistry. 2022 Feb. 16, v. 126, no. 8

    2022  

    Abstract: The presence of excimers, as revealed by broad, structureless, and red-shifted emission, is quite common in a great many organic solution- and solid-phase systems. A fundamental theoretical account of excimer creation and relaxation has generated ... ...

    Abstract The presence of excimers, as revealed by broad, structureless, and red-shifted emission, is quite common in a great many organic solution- and solid-phase systems. A fundamental theoretical account of excimer creation and relaxation has generated enormous interest over the years. Here, a model based on a Holstein–Peierls Hamiltonian is presented to account for absorption and photoluminescence in molecular dimers. The model extends the Frenkel-charge transfer (CT)-Holstein model in order to account for both local and nonlocal coupling to a slow intermolecular vibrational mode. The model shows that excimer emission can be induced either through (1) local intermolecular coupling to the dimer CT states or through (2) the nonlocal Frenkel-CT coupling terms. Finally, by incorporating both the local and nonlocal intermolecular coupling, the measured absorption and excimer emission spectra for a set of two different bis(perylene diimide) covalently linked dimers are successfully reproduced. The evolution from structured to unstructured excimer emission likely occurs via an increase in the nonlocal coupling, but it can also be induced by the stabilization of the diabatic CT state.
    Keywords absorption ; chemical bonding ; models ; photoluminescence
    Language English
    Dates of publication 2022-0216
    Size p. 4067-4081.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1932-7455
    DOI 10.1021/acs.jpcc.1c10255
    Database NAL-Catalogue (AGRICOLA)

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  8. Article ; Online: Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer.

    Hestand, Nicholas J / Spano, Frank C

    Chemical reviews

    2018  Volume 118, Issue 15, Page(s) 7069–7163

    Abstract: The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on ... ...

    Abstract The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and "HJ" aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate architecture leading to a wide array of photophysical behaviors.
    Language English
    Publishing date 2018-04-17
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 207949-5
    ISSN 1520-6890 ; 0009-2665
    ISSN (online) 1520-6890
    ISSN 0009-2665
    DOI 10.1021/acs.chemrev.7b00581
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Identification of Oocyst-Driven

    Álvarez García, Gema / Davidson, Rebecca / Jokelainen, Pikka / Klevar, Siv / Spano, Furio / Seeber, Frank

    Microorganisms

    2021  Volume 9, Issue 11

    Abstract: The apicomplexan zoonotic ... ...

    Abstract The apicomplexan zoonotic parasite
    Language English
    Publishing date 2021-11-13
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2720891-6
    ISSN 2076-2607
    ISSN 2076-2607
    DOI 10.3390/microorganisms9112346
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Associations between circadian misalignment and telomere length in BD: an actigraphy study.

    Spano, Luana / Hennion, Vincent / Marie-Claire, Cynthia / Bellivier, Frank / Scott, Jan / Etain, Bruno

    International journal of bipolar disorders

    2022  Volume 10, Issue 1, Page(s) 14

    Abstract: Background: Life expectancy is significantly decreased in bipolar disorder (BD). This is associated with accelerated cellular aging which can be estimated by telomere length (TL). However, specific determinants of shorter TL in BD are under-explored. ... ...

    Abstract Background: Life expectancy is significantly decreased in bipolar disorder (BD). This is associated with accelerated cellular aging which can be estimated by telomere length (TL). However, specific determinants of shorter TL in BD are under-explored. This study examines whether circadian misalignment (i.e. mismatch between preferred and actual phase of circadian activity rhythms) is associated with shorter TL in BD.
    Methods: Euthymic individuals with BD (n = 101) undertook 21 consecutive days of actigraphy recording and completed the Composite Scale of Morningness (CSM) to assess phase preference for activities (chronotype). Polymerase chain reaction was used to measure TL in blood. Cluster analysis identified circadian aligned/misaligned subgroups as defined by preferred (CSM score) and actual phases of activity (actigraphically determined onset of active and inactive periods). We tested for any associations between TL and clusters, with adjustments for between-cluster differences in socio-demographic and illness factors.
    Results: We identified three clusters: an "Aligned Morning" cluster (n = 31) with preferred and actual timing of activity in the morning, an "Aligned Evening" cluster (n = 37) with preferred and actual timing of activity in the evening and a "Misaligned" cluster (n = 32) with an evening chronotype, but an earlier objective onset of active periods. After adjustment for confounders, we found that TL was significantly associated with circadian misalignment and older age.
    Conclusions: Circadian misalignment may partly explain shorter TL in BD and could contribute to accelerated aging in these individuals.
    Language English
    Publishing date 2022-05-27
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2732954-9
    ISSN 2194-7511
    ISSN 2194-7511
    DOI 10.1186/s40345-022-00260-w
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