| 1. |
- De Vico, Luca, et al.
(author)
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Chemiluminescence of 1,2-dioxetane. Reaction mechanism uncovered
- 2007
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In: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 111:32, s. 8013-8019
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Journal article (peer-reviewed)abstract
- The thermal decomposition of 1,2-dioxetane and the associated production of chemiluminescent products, model for a wide range of chemiluminescent reactions, has been studied at the multistate multiconfigurational second-order perturbation level of theory. This study is in qualitative and quantitative agreement with experimental observations with respect to the activation energy and the observed increase of triplet and singlet excited products as substituents are added to the parent molecule. The, previously incomplete, reaction mechanism of the chemiluminescence of 1,2-dioxetane is now rationalized and described as mainly due to a particular form of entropic trapping.
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| 2. |
- Gagliardi, L, et al.
(author)
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The electronic spectrum of the UO2 molecule
- 2005
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 127:1, s. 86-91
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Journal article (peer-reviewed)abstract
- The electronic spectrum of the UO2 Molecule has been determined using multiconfigurational wave functions together with the inclusion spin-orbit coupling. The molecule has been found to have a (5fphi)(7s), (3)Phi(2u), ground state. The lowest state of gerade symmetry, H-3(4g), corresponding to the electronic configuration (5f)(2) was found 3330 cm(-1) above the ground state. The computed energy levels and oscillator strengths were used for the assignment of the experimental spectrum in the energy range 17000-19000 and 27000-32000 cm(-1).
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| 3. |
- Krogh, Jesper, et al.
(author)
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Growth hormone, prolactin and cortisol response to exercise in patients with depression
- 2010
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In: Journal of Affective Disorders. - : Elsevier BV. - 1573-2517 .- 0165-0327. ; 125:1-3, s. 189-197
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Journal article (peer-reviewed)abstract
- Background: A blunted growth hormone and prolactin response to pharmacological stress test have previously been found in depressed patients, as well as an increased cortisol response to psychosocial stress. This study investigated these hormones in response to acute exercise using an incremental bicycle test. Method: A cross-sectional comparison of cortisol, growth hormone, and prolactin in depressed (n = 137) and healthy (n = 44) subjects during rest and in response to an incremental bicycle test. Secondly, we tested the depressed patients again after a 4-month randomized naturalistic exercise intervention. Results: Resting plasma levels of growth hormone (GH), cortisol, or prolactin (PRL) did not differ between depressed and healthy subjects (all p-values > .12). In response to an incremental bicycle test the GH (p = .02) and cortisol (p = .05) response in depressed was different compared to healthy controls. The effect of acute exercise stress on PRL (p = .56) did not differ between depressed and healthy subjects. Apart from a decrease in CH response in the strength-training group (p = .03) the pragmatic exercise intervention did not affect resting hormonal levels, or the response to acute exercise. Conclusions: Patients with mild to moderate depression had a different growth hormone and cortisol response to acute exercise stress compared to healthy controls. Strength training was able to reduce the growth hormone response to acute exercise stress in this patient population. Studies with more rigorous inclusion criteria and higher exercise frequencies are needed to evaluate and confirm the possible effect of exercise in depressed subjects. (C) 2010 Elsevier B.V. All rights reserved.
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| 4. |
- Krogh, Jesper, et al.
(author)
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N-terminal pro-atrial natriuretic peptide response to acute exercise in depressed patients and healthy controls
- 2011
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In: Psychoneuroendocrinology. - : Elsevier BV. - 1873-3360 .- 0306-4530. ; 36:5, s. 656-663
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Journal article (peer-reviewed)abstract
- Background: The dysfunction of hypothalamic-pituitary-adrenal (HPA) axis in major depression includes hyperactivity and reduced feedback inhibition. Atrial natriuretic peptide (ANP) is able to reduce the HPA-axis response to stress and has an anxiolytic effect in rodents and humans. We hypothesized that patients with depression would have an attenuated N-terminal proANP (NT-proANP) response to acute exercise compared to healthy controls. Secondly, we aimed to assess the effect of antidepressants on NT-proANP response to acute exercise. Methods: We examined 132 outpatients with mild to moderate depression (ICD-10) and 44 healthy controls, group matched for age, sex, and BMI. We used an incremental bicycle ergometer test as a physical stressor. Blood samples were drawn at rest, at exhaustion, and 15, 30, and 60 min post-exercise. Results: The NT-proANP response to physical exercise differed between depressed subjects and healthy controls (group x time; F-4,F-162.9 = 10.92; p < 0.001). The increase from rest to VO2max was 0.98 (SD 0.8) and 1.96 nmol/l (SD 1.1), respectively, for depressed subjects and healthy controls (mean diff: 0.98 nmol/l; 95% CI 0.7-1.3; t = 6.63; df = 170; p < 0.001). The increase in NT-proANP from rest to peak VO2max was 1.27 (SD 1.0) and 0.84 nmol/l (SD 0.6), respectively, for unmedicated and medicated patients (mean diff: 0.42 nmol/l; 95% CI 0.1-0.8; t = 2.56; df = 128; p = 0.01). Conclusion: We observed an attenuated NT-proANP response to acute physical stress in depressed patients. Antidepressants were associated with an independent suppressive effect on the NT-proANP response. (c) 2010 Elsevier Ltd. All rights reserved.
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| 5. |
- Krogh, Jesper Wisborg
(author)
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Development and Implementation of Methods in Theoretical Chemistry
- 2006
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Doctoral thesis (other academic/artistic)abstract
- The method development research in the field of theoretical chemistry is the never ending quest for methods that are faster, gives more accurate results, and expands the possibilities. The work in this thesis is no exception to that statement. Thus a CI routine more suited for calculations on large active spaces was implemented in the RASSCF code of Molcas; a new scheme for localizing multipole moments and polarizabilities were developed and implemented; and a parallel SCF code that provides super linear speed up saw the light of the day. These implementations were largely used throughout the remainder of the work, where the nuclear quadrupole moment of tin and the electronic spectrum of UO2 were determined; the photodissociation of bromoiodomethane was investigated; and the ability of localized properties to reproduce the electrostatic potential was tested.
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| 6. |
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| 7. |
- Krogh, Jesper Wisborg, et al.
(author)
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The condensation energy of the homogeneous superconducting gas.
- 2003
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In: Computer Physics Communications. - 0010-4655. ; 150:1, s. 53-63
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Journal article (peer-reviewed)abstract
- We present CHS, a computer program designed to calculate the condensation energy of the homogeneous superconducting electron gas. The correlation energy, which we treat at the level of the RPA, is an essential ingredient for the construction of a local density approximation in the framework of density functional theory for superconductors (SCDFT) [Kurth et al., Phys. Rev. Lett. 83 (1999) 2628].
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| 8. |
- Krogh, Jesper Wisborg, et al.
(author)
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The prediction of the nuclear quadrupole splitting of Sn-119 Mossbauer spectroscopy data by scalar relativistic DFT calculations
- 2006
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In: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 12:19, s. 5116-5121
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Journal article (peer-reviewed)abstract
- The electric field gradient components for the tin nucleus of 34 tin compounds of experimentally known structures and Sn-119 Mossbauer spectroscopy parameters were computed at the scalar relativistic density functional theory level of approximation. The theoretical values of the electric field gradient components were used to determine a quantity, V, which is proportional to the nuclear quadrupole splitting parameter (Delta E). In a subsequent linear regression analysis the effective nuclear quadrupole moment, Q, was evaluated. The value of (11.9 +/- 0.1) fm(2) is a significant improvement over the non-relativistic result of (15.2 +/- 4.4) fm(2) and is in agreement with the experimental value of (10.9 +/- 0.8) fm(2). The average mean square error Delta E-calcd-Delta E-exptl = +/- 0.3 mm s(-1) is a factor of two smaller than in the non-relativistic case. Thus, the approach has a quality which provides accurate support for the structure interpretation by Sn-119 spectroscopy. It was noted that geometry optimization at the relativistic level does not significantly increase the quality of the results compared with non-relativistic optimized structures. The accuracy in the approach called on us to consider the singlet-triplet state nature of the electronic structure of one of the investigated compounds.
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| 9. |
- Lindh, Roland, 1958-, et al.
(author)
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Semidirect parallel self-consistent field : the load balancing problem in the input/output intensive self-consistent field iterations
- 2003
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In: Theoretical Chemistry accounts. - : Springer Science and Business Media LLC. - 1432-881X .- 1432-2234. ; 110:3, s. 156-164
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Journal article (peer-reviewed)abstract
- The full capacity of contemporary parallel computers can, in the context of iterative ab initio procedures like, for example, self-consistent field (SCF) and multiconfigurational SCF, only be utilized if the disk and input/output (I/O) capacity are fully exploited before the implementation turns to an integral direct strategy. In a recent report on parallel semidirect SCF http://www.tc.cornell.edu/er/media/1996/collabrate.html, http://www.fp.mcs.anl.gd/grand-challenges/chem/non-direct/index.html it was demonstrated that super-linear speedups are achievable for algorithms that exploit scalable parallel I/O. In the I/O-intensive SCF iterations of this implementation a static load balancing, however, was employed, dictated by the initial iteration in which integral evaluation dominates the central processing unit activity and thus determines the load balancing. In the present paper we present the first implementation in which load balancing is achieved throughout the whole SCF procedure, i.e. also in subsequent iterations. The improved scalability of our new algorithm is demonstrated in some test calculations, for example, for 63-node calculation a speedup of 104 was observed in the computation of the two-electron integral contribution to the Fock matrix.
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| 10. |
- Liu, Ya-Jun, et al.
(author)
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Spin-orbit ab initio investigation of the photolysis of bromoiodomethane
- 2006
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In: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 7:4, s. 955-963
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Journal article (peer-reviewed)abstract
- The photodissociation of bromoiodomethane has been investigated by spin-orbit ab initio calculations. The experimentally observed A- and B-bands and the corresponding photoproducts were assigned by multistate second-order multiconfigurationol perturbation theory in conjunction with spin-orbit interaction through complete active space state interaction potential energy curves, vertical excitation energies, and oscillator strengths of low-lying excited states. The present conclusions with respect to the dissociation process in the B-band are different compared with those of previous studies. The reaction between the iso-CH2,Br-I and iso-CH2I-Br species has also been studied. Finally, a set of stable excited states was identified for both isomers. These species might be of importance in the recombination process that follows the photodissociotion in a solvent.
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