| 1. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity exploration from the Arctic to the Antarctic. Part 3. The SWEDARP expedition Oct 1988 – April 1989
- 2015
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:004, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Antarctic Research Expedition named “SWEDARP” was performed during October 1988 through April 1989. The aim of our project was to study the radioactivity in air and water from Gothenburg to the Antarctic. Between Gothenburg and the Equator, the average activity concentration of 7Be in air was 4.3 ± 0.7 mBq/m3. The activity concentration of 7Be in the South Atlantic down to Antarctica varied between 1.3 and 1.7 with an average of 1.5 ± 0.8 mBq/m3. The average activity concentration of 210Pb in air during autumn 1988 on the route Gothenburg- Montevideo was about 290±270 micro-Bq/m3 and on the return in spring 1989 it was about 230±140 micro-Bq/m3. At the Equator, the average activity concentration of 210Pb in November 1988 was about 630±170 and in April 1989 about 260±210 microBq/m3. In the South Atlantic down to Antarctica during February-March 1989, the activity concentration of 210Pb varied between 11 and 58 micro-Bq/m3. The average activity concentration of 210Po in air during the route Gothenburg- Montevideo in 1988 was about 63±58, and on the return, it was about 60±44 The Swedish Antarctic Research Expedition named “SWEDARP” was performed during October 1988 through April 1989. The aim of our project was to study the radioactivity in air and water from Gothenburg to the Antarctic. Between Gothenburg and the Equator, the average activity concentration of 7Be in air was 4.3 ± 0.7 mBq/m3. The activity concentration of 7Be in the South Atlantic down to Antarctica varied between 1.3 and 1.7 with an average of 1.5 ± 0.8 mBq/m3. The average activity concentration of 210Pb in air during autumn 1988 on the route Gothenburg- Montevideo was about 290±270 micro-Bq/m3 and on the return in spring 1989 it was about 230±140 micro-Bq/m3. At the Equator, the average activity concentration of 210Pb in November 1988 was about 630±170 and in April 1989 about 260±210 microBq/m3. In the South Atlantic down to Antarctica during February-March 1989, the activity concentration of 210Pb varied between 11 and 58 micro-Bq/m3. The average activity concentration of 210Po in air during the route Gothenburg- Montevideo in 1988 was about 63±58, and on the return, it was about 60±44 micro-Bq/m3. At the Equator, the average activity concentration in Nov 1988 was about 132±45, and in April 1989 about 70±60 micro-Bq/m3. The activity concentration of 210Po in the South Atlantic down to Antarctica during February-March 1989 varied between 6 and 14 micro-Bq/m3. The inventory (Bq.m-2) of various deposited ratio nuclides, measured in moss, lichen, soil and lake sediments was: 280 ±110 for 210Pb (excess); 155 ± 95 for 137Cs, 4.6 ± 2.6 for 239+240Pu, 1.6 ± 1.0 for 241Am and, 0.95± 0.5 for 238Pu. 137Cs activity concentration (Bq.m-3) in surface waters samples along the route of the SWEDARP expedition was about 3 Bq.m-3 above 20 °N , decreased to about 2 Bq.m-3 between 20 °N and 40 °S where it decrease to about 1 Bq.m-3 , and at 55 °S (e) there is a further decrease to about 0.3 Bq.m-3. Radio-Caesium, which originates from atmospheric nuclear weapons tests carried out in the late 1950's and the early 1960's shows a long residence time in surface waters of the North and South Atlantic Oceans with half-time, corrected for physical decay estimated to be more than bout 100 years. Concentration factor for 137Cs estimated to 15000 for fish in the Antarctic is much higher than the value of 500 given by The IAEA 1985. Concentration factors for MacroAlgea/Water, was found to be about 1800 in the Antarctic compared to 100 the Arctic. The 239+240Pu activity concentrations in the surface water was about 8 mBq.m-3 in the latitude band 5°-25 °N , about 3 mBq.m-3 in the latitude band 25-5 °N; and about 1,5 mBq.m-3 in the latitude band 0 °S-60 °S. Plutonlum-238 activity was measured in a few water samples from the southern hemisphere with activity ratio of 238Pu to 239+240Pu in the range of 0.14-0.22. Plutonium isotopes 239+240Pu from atmospheric nuclear weapons tests has a low half-life of 7-8 years due to the higher affinity to sinking particles for Pu than Cs. In the southern hemisphere, 238Pu was found as the result of the 1964 burn-up of a satellite in the atmosphere over the Mozambique Channel. The Average activity concentrations (Bq/kgdw,) of 137Cs are in flesh of seals 2.5, penguins 0.2 and, fish 2.5 in liver of seals 0.6 and penguins 0.7 and in kidneys of seals 0.5. The Average activity concentrations (Bq/kgdw) of 210Po are in flesh of seals 8, penguins 4 and, fish 7, in liver of seals 110 and penguins 43 and, fish 5, and in kidneys of seals 91 and of penguins 43. The Average activity concentrations (Bq/kgdw,) of 210Pb are in flesh of seals 0,3, penguins 0,2, and fish 0.6, in liver of seals 4 and penguins 1 and, fish 1, and in kidneys of seals 1 and of penguins 1. The Average activity concentration of 137Cs in samples of Krill is about 1.7 Bq/kgdw of 210Po and 210Pb are in samples of Amphipods, 87 and 1.4 Bq/kgdw respectively. Radio-Caesium, which originates from atmospheric nuclear weapons tests carried out in the late 1950's and the early 1960's shows a long residence time in surface waters of the North and South Atlantic Oceans with half-time, corrected for physical decay estimated to be more than bout 100 years. Plutonium isotopes 239+240Pu from atmospheric nuclear weapons tests has a low half-life of 7-8 years due to the higher affinity to sinking particles for Pu than Cs. In the southern hemisphere, 238Pu was found as the result of the 1964 burn-up of a satellite in the atmosphere over the Mozambique Channel.Bq/m3. At the Equator, the average activity concentration in Nov 1988 was about 132±45, and in April 1989 about 70±60 micro-Bq/m3. The activity concentration of 210Po in the South Atlantic down to Antarctica during February-March 1989 varied between 6 and 14 micro-Bq/m3. The inventory (Bq.m-2) of various deposited ratio nuclides, measured in moss, lichen, soil and lake sediments was: 280 ±110 for 210Pb (excess); 155 ± 95 for 137Cs, 4.6 ± 2.6 for 239+240Pu, 1.6 ± 1.0 for 241Am and, 0.95± 0.5 for 238Pu. 137Cs activity concentration (Bq.m-3) in surface waters samples along the route of the SWEDARP expedition was about 3 Bq.m-3 above 20 °N , decreased to about 2 Bq.m-3 between 20 °N and 40 °S where it decrease to about 1 Bq.m-3 , and at 55 °S (e) there is a further decrease to about 0.3 Bq.m-3. Radio-Caesium, which originates from atmospheric nuclear weapons tests carried out in the late 1950's and the early 1960's shows a long residence time in surface waters of the North and South Atlantic Oceans with half-time, corrected for physical decay estimated to be more than bout 100 years. Concentration factor for 137Cs estimated to 15000 for fish in the Antarctic is much higher than the value of 500 given by The IAEA 1985. Concentration factors for MacroAlgea/Water, was found to be about 1800 in the Antarctic compared to 100 the Arctic. The 239+240Pu activity concentrations in the surface water was about 8 mBq.m-3 in the latitude band 5°-25 °N , about 3 mBq.m-3 in the latitude band 25-5 °N; and about 1,5 mBq.m-3 in the latitude band 0 °S-60 °S. Plutonlum-238 activity was measured in a few water samples from the southern hemisphere with activity ratio of 238Pu to 239+240Pu in the range of 0.14-0.22. Plutonium isotopes 239+240Pu from atmospheric nuclear weapons tests has a low half-life of 7-8 years due to the higher affinity to sinking particles for Pu than Cs. In the southern hemisphere, 238Pu was found as the result of the 1964 burn-up of a satellite in the atmosphere over the Mozambique Channel. The Average activity concentrations (Bq/kgdw,) of 137Cs are in flesh of seals 2.5, penguins 0.2 and, fish 2.5 in liver of seals 0.6 and penguins 0.7 and in kidneys of seals 0.5. The Average activity concentrations (Bq/kgdw) of 210Po are in flesh of seals 8, penguins 4 and, fish 7, in liver of seals 110 and penguins 43 and, fish 5, and in kidneys of seals 91 and of penguins 43. The Average activity concentrations (Bq/kgdw,) of 210Pb are in flesh of seals 0,3, penguins 0,2, and fish 0.6, in liver of seals 4 and penguins 1 and, fish 1, and in kidneys of seals 1 and of penguins 1. The Average activity concentration of 137Cs in samples of Krill is about 1.7 Bq/kgdw of 210Po and 210Pb are in samples of Amphipods, 87 and 1.4 Bq/kgdw respectively. Radio-Caesium, which originates from atmospheric nuclear weapons tests carried out in the late 1950's and the early 1960's shows a long residence time in surface waters of the North and South Atlantic Oceans with half-time, corrected for physical decay estimated to be more than bout 100 years. Plutonium isotopes 239+240Pu from atmospheric nuclear weapons tests has a low half-life of 7-8 years due to the higher affinity to sinking particles for Pu than Cs. In the southern hemisphere, 238Pu was found as the result of the 1964 burn-up of a satellite in the atmosphere over the Mozambique Channel.
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| 2. |
- Anderson, Leif G., et al.
(författare)
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The effect of the Siberian tundra on the environment of the shelf seas and the Arctic Ocean
- 1999
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Ingår i: Ambio. - 0044-7447. ; 28:3, s. 270-280
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Tidskriftsartikel (refereegranskat)abstract
- The Tundra Ecology -94 expedition investigated inflow of inorganic and organic carbon to the shelf seas by river runoff, and its transformation by biochemical processes in seawater and sediment. In addition, anthropogenic radionuclides, 137Cs, 90Sr, and 239,240Pu, were studied in water and sediments. The distribution of dissolved inorganic carbon indicates that the majority of the Ob and Yenisey discharges flow into the Laptev Sea before entering the central Arctic Ocean. The sediment study shows that there is a marked difference in benthic oxygen uptake, efflux of dissolved inorganic carbon and nutrients between localities. 137Cs activity from the Chernobyl accident is 30% in the Barents, Kara, and Laptev Seas. 137Cs increased from 5-8 Bq m-3 in Barents Sea, 5-13 Bq m-3 in the Kara Sea to 8-15 Bq m-3 in the Laptev Sea, but with locally low concentrations at the river mouths. Corresponding values for 90Sr were 2.5, 3, and 4 Bq m-3, respectively.
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| 3. |
- Andersson, Anton, et al.
(författare)
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Ground granulated iron silicate slag as supplementary cementitious material: Effect of prolonged grinding and granulation temperature
- 2023
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Ingår i: Cleaner Materials. - : Elsevier. - 2772-3976. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The metallurgical and cement industries contribute significantly to anthropogenic carbon dioxide emissions. Utilizing oxidic by-products from the metallurgical industry as supplementary cementitious materials (SCMs) can improve resource efficiency and reduce emissions from cement production. Iron silicate copper slags have been studied as SCMs, but mainly in systems where Portland cement is used as an activator. There is limited research on the inherent reactivity of the slag under changing processing conditions. The present study offers insight into the effect of granulation temperature and grinding on the inherent reactivity of an industrially produced iron silicate copper slag. The results showed that granulation temperature had an insignificant effect on reactivity, while grinding generated substantial improvements. The latter effect was concluded to stem from the increased specific surface area, increased number of sites for nucleation and growth of hydrates, and changes in the inherent reactivity owing to structural changes induced by the grinding.
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| 4. |
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| 5. |
- Aquilante, Francesco, et al.
(författare)
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Cholesky decomposition-based multiconfiguration second-order perturbation theory (CD-CASPT2) : application to the spin-state energetics of Co-III(diiminato)(NPh).
- 2008
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 4:5, s. 694-702
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure and low-lying electronic states of a Co-III(diiminato)(NPh) complex have been studied using mulficonfigurational wave function theory (CASSCF/CASPT2) The results have been compared to those obtained with density functional theory. The best agreement with ab initio results is obtained with a modified B3LYP functional containing a reduced amount (15%) of Hartree-Fock exchange. A relativistic basis set with 869 functions has been employed in the most extensive ab initio calculations, where a Cholesky decomposition technique was used to overcome problems arising from the large size of the two-electron integral matrix. It is shown that this approximation reproduces results obtained with the full integral set to a high accuracy, thus opening the possibility to use this approach to perform multiconfigurational wave-function-based quantum chemistry on much larger systems relative to what has been possible until now.
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| 6. |
- Aquilante, Francesco, et al.
(författare)
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Software news and update MOLCAS 7 : The Next Generation
- 2010
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Ingår i: Journal of Computational Chemistry. - : Wiley. - 0192-8651 .- 1096-987X. ; 31:1, s. 224-247
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Forskningsöversikt (refereegranskat)abstract
- Some of the new unique features of the MOLCAS quantum chemistry package version 7 are presented in this report. In particular, the Cholesky decomposition method applied to some quantum chemical methods is described. This approach is used both in the context of a straight forward approximation of the two-electron integrals and in the generation of so-called auxiliary basis sets. The article describes how the method is implemented for most known wave functions models: self-consistent field, density functional theory, 2nd order perturbation theory, complete-active space self-consistent field multiconfigurational reference 2nd order perturbation theory, and coupled-cluster methods. The report further elaborates on the implementation of a restricted-active space self-consistent field reference function in conjunction with 2nd order perturbation theory. The average atomic natural orbital basis for relativistic calculations, covering the whole periodic table, are described and associated unique properties are demonstrated. Furthermore, the use of the arbitrary order Douglas-Kroll-Hess transformation for one-component relativistic calculations and its implementation are discussed. This section especially focuses on the implementation of the so-called picture-change-free atomic orbital property integrals. Moreover, the ElectroStatic Potential Fitted scheme, a version of a quantum mechanics/molecular mechanics hybrid method implemented in MOLCAS, is described and discussed. Finally, the report discusses the use of the MOLCAS package for advanced studies of photo chemical phenomena and the usefulness of the algorithms for constrained geometry optimization in MOLCAS in association with such studies.
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| 7. |
- Gagliardi, L, et al.
(författare)
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Theoretical study of the lowest B-1(U) states of trans-stilbene
- 2002
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Ingår i: The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory. - : American Chemical Society (ACS). - 1520-5215. ; 106:32, s. 7355-7361
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Tidskriftsartikel (refereegranskat)abstract
- The results of a theoretical study of the ground state, 1(1)A(g), and of the lowest B-1(u) states of trans-stilbene are presented. The vertical and adiabatic excitation energies of the lowest B-1(u) states have been computed using multiconfigurational SCF theory, followed by second-order perturbation. theory. It is shown that the two lowest excited states are separated by a small energy gap in the Franck-Condon region. They are the 1(1)B(u), characterized by the HOMO-->LUMO single excitation substantially localized on the ethylenic moiety, and the 2(1)B(u), formed by a combination,of one electron excitations localized mainly on the benzene rings. The most intense transition is found to be the lowest in energy when the interaction between different states is included at the level of second-order perturbation theory. The vibronic structure of emission and absorption spectra of the two lowest B-1(u) states have been determined within the Franck-Condon approximation. The spectrum calculated for the 1(1)B(u) state agrees with the experimental spectrum, while the low intensity band computed for the 2(1)B(u) state has no experimental counterpart. It is concluded that this band is buried in the strong 1(1)B(u) absorption and therefore not observed.
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| 8. |
- Ghigo, Giovanni, et al.
(författare)
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A modified definition of the zeroth-order Hamiltonian in multiconfigurational perturbation theory (CASPT2)
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 396:1-3, s. 142-149
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Tidskriftsartikel (refereegranskat)abstract
- A new shifted zeroth-order Hamiltonian is presented, which will be used in second-order multiconfigurational perturbation theory (CASPT2). The new approximation corrects for the systematic error of the original formulation, which led to an relative overestimate of the correlation energy for open shell system, resulting in too small dissociation and excitation energies. Errors in the D, values for 49 diatomic molecules have been reduced with more than 50%. Calculations on excited states of the N-2 and benzene molecules give a similar improvement. (C) 2004 Elsevier B.V. All rights reserved.
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| 9. |
- Guehne, Otfried, et al.
(författare)
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Compatibility and noncontextuality for sequential measurements
- 2010
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Ingår i: PHYSICAL REVIEW A. - 1050-2947. ; 81:2, s. 022121-
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Tidskriftsartikel (refereegranskat)abstract
- A basic assumption behind the inequalities used for testing noncontextual hidden variable models is that the observables measured on the same individual system are perfectly compatible. However, compatibility is not perfect in actual experiments using sequential measurements. We discuss the resulting "compatibility loophole" and present several methods to rule out certain hidden variable models that obey a kind of extended noncontextuality. Finally, we present a detailed analysis of experimental imperfections in a recent trapped-ion experiment and apply our analysis to that case.
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| 10. |
- Gusarov, Sergey, et al.
(författare)
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Correlation potentials for a multiconfigurational-based density functional theory with exact exchange
- 2004
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Ingår i: Theoretical Chemistry accounts. - : Springer Science and Business Media LLC. - 1432-881X .- 1432-2234. ; 112:2, s. 84-94
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Tidskriftsartikel (refereegranskat)abstract
- A density functional theory based on a complete active space self consistent field (CASSCF) reference function with exact exchange is discussed. It is first shown that such a theory may be formulated with a correlation potential dependent on the density function and on the active space used. Auxiliary functions, such as the on-top two-particle density, are used to define uniquely the potential for different active spaces. The paper also analyses the correlation functional for some atomic and molecular cases. Large ab initio calculations are performed to obtain accurate density functions. A correlation potential is then fitted such that the reference CASSCF function gives the same density. The correlation potential values are saved in a data base for future analysis.
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| 11. |
- Karlsson, Örjan, et al.
(författare)
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Skidtjärn.Topografisk och morfologisk studie av sjö i Hälsingland
- 1970
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Skidtjärn ligger inom det sjörika området strax innanför kustslätten i Norrlandsterrängen. Den bildades under kvartärtiden, sannolikt i en sänka, och uppdämdes mellan bergen, i norr av mäktiga moränavlagringar, i söder och öster av utsvämmat äsmaterial . Sjöns östra del befinner sig inom ett kvartsitområde med hög sprickfrekvens, vilket kan förklara bottenreliefen liksom det uppvälvande källvattnet i denna del. På botten framträder höjdryggar, vilkas from tyder på bildningar utskulpterade av isen. Botten i sjöns västra del bildar en relativt plan yta, uppbyggd av mäktiga sediment från den närbelägna åsens norra sluttning.
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| 12. |
- Karlström, Gunnar, et al.
(författare)
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MOLCAS : a program package for computational chemistry
- 2003
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Ingår i: Computational materials science. - 0927-0256 .- 1879-0801. ; 28:2, s. 222-239
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Tidskriftsartikel (refereegranskat)abstract
- The program system MOLCAS is a package for calculations of electronic and structural properties of molecular systems in gas, liquid, or solid phase. It contains a number of modern quantum chemical methods for studies of the electronic structure in ground and excited electronic states. A macromolecular environment can be modeled by a combination of quantum chemistry and molecular mechanics. It is further possible to describe a crystalline material using model potentials. Solvent effects can be treated using continuum models or by combining quantum chemical calculations with molecular dynamics or Monte-Carlo simulations. MOLCAS is especially adapted to treat systems with a complex electronic structure, where the simplest quantum chemical models do not work. These features together with the inclusion of relativistic effects makes it possible to treat with good accuracy systems including atoms from the entire periodic system. MOLCAS has effective methods for geometry optimization of equilibria, transition states, conical intersections, etc. This facilitates studies of excited state energy surfaces, spectroscopy, and photochemical processes.
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| 13. |
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| 14. |
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| 15. |
- Lorentzon, Johan, et al.
(författare)
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A CASPT2 study of the valence and lowest Rydberg electronic states of benzene and phenol.
- 1995
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Ingår i: Theoretica Chimica Acta. - 0040-5744. ; 91, s. 91-108
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Tidskriftsartikel (refereegranskat)abstract
- The valence excited states and the 3s, 3p, and 3d (united atom) Rydberg states of benzene and phenol have been obtained by the CASPT2 method, which computes a second-order perturbation correction to complete active space self-consistent field (CASSCF) energies. All non-zero dipole oscillator strengths are also computed, at the CASSCF level. For benzene, 16 singlet and 16 triplet states with excitation energies up to ca. 7.86 eV (63 400 cm–1) are obtained. Of these, 12 singlet and three triplet energies are experimentally known well enough to allow meaningful comparison. The average error is around 0.1 eV. The highest of these singlet states (21 E2g) is the highest valence ππ* state predicted by elementary π-electron theory. Its energy is then considerably lower than has been suggested from laser flash experiments, but in perfect agreement with a reinterpretation of that experiment. For phenol, 27 singlet states are obtained, in the range 4.53–7.84 eV (63 300 cm−1). Only the lowest has a well-known experimental energy, which agrees with the computed result within 0.03 eV. The ionization energy is in error by 0.05 eV.
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| 16. |
- Lyon, Jonathan T., et al.
(författare)
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Infrared spectrum and bonding in uranium methylidene dihydride, CH2=UH2
- 2007
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 1520-510X .- 0020-1669. ; 46:12, s. 4917-4925
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Tidskriftsartikel (refereegranskat)abstract
- Uranium atoms activate methane upon ultraviolet excitation to form the methyl uranium hydride CH3-UH, which undergoes alpha-H transfer to produce uranium methylidene dihydride, CH2UH2. This rearrangement most likely occurs on an excited-quintet potential-energy surface and is followed by relaxation in the argon matrix. These simple U + CH4 reaction products are identified through isotopic substitution ((CH4)-C-13, CD4, CH2D2) and density functional theory frequency and structure calculations for the strong U-H stretching modes. Relativistic multiconfiguration (CASSCF/CASPT2) calculations substantiate the agostic distorted C-1 ground-state structure for the triplet CH2UH2 molecule. We find that uranium atoms are less reactive in methane activation than thorium atoms. Our calculations show that the CH2UH2 complex is distorted more than CH2ThH2. A favorable interaction between the low energy open-shell U(5f) sigma orbital and the agostic hydrogen contributes to the distortion in the uranium methylidene complexes.
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| 17. |
- Malmquist, Per-Åke, et al.
(författare)
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An ab initio study of the molecular structure andvibration-rotation spectrum of the triplet radical HCCN
- 1988
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Ingår i: THEORETICA CHIMICA ACTA. - 0040-5744. ; 73:2-3, s. 155-171
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Tidskriftsartikel (refereegranskat)abstract
- The bent triplet cyanocarbene H-C-CN and the linear triplet allene H-C=C=N have been studied by the CASSCF and CI methods, using a DZP basis. Relaxation of all geometrical parameters for the CASSCF energy results in a bent molecule with CCH angle 133° and a barrier to linearity of 6.4 kcal/mol, which was lowered to 2.3 kcal/mol in a subsequent CI calculation. The Davidson correction lowered it further to 1.8 kcal/mol.A 26-term analytical potential energy surface (PES) was fitted to CASSCF, CI, and Davidson corrected CI energies in 94 different geometries. Using these three potentials, the semi-rigid bender model predicts a CCH bending frequency of 782, 505, and 503 cm–1, resp., which compares favourably with an experimentally observed IR transition line at 458 cm–1. For the deuterated species, the corresponding frequencies are 610, 407, and 402 cm–1, to be compared with two possible absorption lines at 405 and 317.5 cm–1.The PES was then parametrized by adding a variable CCH angle dependence, and a comprehensive vibration-rotation spectrum was calculated variationally, using the exact 4-atom vibration-rotation kinetic Hamiltonian, for a range of barrier heights. Comparison with experiment indicates a barrier in the range 1±0.5 kcal/mol.
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| 18. |
- Malmqvist, Per-Åke, et al.
(författare)
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The restricted active space (RAS) state interaction approach with spin-orbit coupling
- 2002
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Ingår i: Chemical Physics Letters. - 0009-2614. ; 357:3-4, s. 230-240
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Tidskriftsartikel (refereegranskat)abstract
- A method to compute spin-orbit coupling between electronic states is presented. An effective one-electron spin-orbit Hamiltonian is used, based on atomic mean field integrals, The basic electronic states are obtained using the restricted active space (RAS) SCF method. The Hamiltonian matrix is obtained by an extension of the restricted active space state interaction (RASSI) method. Several hundred states can be included. Tests for atoms and molecules from the entire periodic system show accurate results. Computed spin-orbit effects on relative energies are normally accurate within a few percent. The method has been included in the MOLCAS-5.0 quantum chemistry software. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 19. |
- Masso, H., et al.
(författare)
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Ab initio characterization of C-5
- 2007
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 127:15
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the structure and spectroscopic parameters of the C-5 cluster are determined using multiconfigurational quantum chemical methods as implemented in the MOLCAS software. A number of spectroscopic properties (band center positions, l-doubling parameters, and rotational constants) have been characterized. From the new results, the assignments of previous astrophysical observations [J. Goicoechea , Astrophys. J. 609, 225 (2004)] are discussed. A detailed exploration of the global potential energy surface confirms that C-5 has a X (1)Sigma(+)(g) linear isomer of prominent stability and, at least, three minimum energy structures showing singlet electronic ground states. Two of them are cyclic and one has a nonplanar geometry. Vertical and adiabatic electronic transitions and vibrational spectroscopic parameters are determined for the most stable linear isomer using multiconfigurational second order perturbation theory (CASPT2) using an active space containing 12 valence orbitals with 12 active electrons and extended ANO-type basis sets. The infrared spectrum has been analyzed from an anharmonic force field derived form the local surface, determined from the energies of a grid of 1350 geometries. The force field includes four coupling terms. The CASPT2 band center position of the nu(7)(pi(u)) anharmonic fundamental has been calculated to be at 102 cm(-1), which validates the assignment to C-5 of the pattern of bands centered at 102 cm(-1) observed with the ISO telescope. (C) 2007 American Institute of Physics.
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| 20. |
- Olsen, Jeppe, et al.
(författare)
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A non-linear approach to configuration interaction: The low-rank CI method (LR CI)
- 1987
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 133:2, s. 91-101
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Tidskriftsartikel (refereegranskat)abstract
- An alternative to the linear CI expansion is presented, which is based on the spectral resolution of the double excitation CI coefficients arranged as a symmetric matrix. The resulting energy expression is a quartic function of the new variables, where the double excitation operator is given as T̂2 = ∑IMωI(d̂I)2, where d̂dI is a single excitation operator: d̂I =∑Ia,d̂IiaÊai. Since M is a small number, the number of variables is reduced considerably compared to normal SDCI, with only little loss in accuracy. A program for non-linear CI calculations has been written and is presented with results for H2O and N2. The method can easily be extended to include orbital optimization and cluster terms in the wavefunction, still yielding a fully variational approximation to the Schrödinger equation.
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| 21. |
- Palmqvist, Richard, et al.
(författare)
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hTERT gene copy number is not associated with hTERT RNA expression or telomerase activity in colorectal cancer
- 2005
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Ingår i: International Journal of Cancer. - Geneve : International union against cancer. - 0020-7136 .- 1097-0215. ; 116:3, s. 395-400
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Tidskriftsartikel (refereegranskat)abstract
- In a majority of malignant human tumors telomerase activity can be detected, suggesting an immortal phenotype. Expression of the reverse transcriptase subunit, hTERT, in the human telomerase complex is required for telomerase activity. The regulation of hTERT, from gene level to a fully functional protein, is still a poorly understood process. Increased copy number of the hTERT gene has been demonstrated in a significant portion of established cell lines and tumors of different origin but its relevance for telomerase activity levels is unclear. In the present study, we examined the hTERT gene copy number using fluorescence in situ hybridization (FISH) in samples from 64 colorectal carcinomas and an increased copy number (≥ 3 hTERT gene copies/nucleus) was observed in 31 cases (48%). No statistical association existed between hTERT gene copy number and hTERT RNA expression or telomerase activity. However, a significant relationship was found between an increase in hTERT gene copy number and p53 protein accumulation (p = 0.002) and aneuploidy (p = 0.036). Only 4 tumors showed microsatellite instability, 3 of which had a normal hTERT gene copy number. The data indicated that the increased copy number of the hTERT gene in colorectal carcinoma was a result of genomic instability with no obvious consequence for telomerase activity levels.
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| 22. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity exploration from the Arctic to the Antarctic. Part 4: The Arctic Ocean-91 expedition
- 2015
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:005, s. 1-14
-
Tidskriftsartikel (refereegranskat)abstract
- The Arctic Ocean expedition in 1991 with the Swedish icebreaker M/S Oden was focused on oceanography and geology. The aim of our project was exploring the activity concentrations in surface air of 7Be, 210Pb. and 210Po in the surface air, radioactive isotopes of Caesium (134Cs, 137Cs) and plutonium (239+240Pu) in seawater. During the cruise in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average activity concentrations in surface air of 7Be was 0.6±0.4 mBq.m-3 , 210Pb 46±34 microBq.m-3 and 210Po 37±23 microBq.m-3 The activity concentration of 137Cs in the surface of the Arctic Ocean was in the range of 8-12 Bq.m-3. When crossing the Nansen basin the activity concentration of 137Cs increased to about 18 Bq.m-3 at 88 °N 80 °E, and there was an accumulation of 137Cs in an area around at 88 °N and 80-100 °E and locally increased activity at 83 °N 10 °E. The 134Cs/137Cs activity ratios was about 0.02 due to the contribution mainly from Sellafield and a few percent contribution from Chernobyl. The 134Cs/137Cs activity ratio decreased to about 0.002-0.005 in areas of high 137Cs activity concentration which exclude contribution of 134Cs of nuclear reactor fuel. The activity concentration of 239+240Pu in the surface of the Arctic Ocean was in the range of 6 - 8 mBq.m-3. But locally the activity concentration of 239+240Pu was found to be increased to 11 mBq.m-3 at 86°N 48-53°E, and to 16 mBq.m-3 at 83°N 10°E.
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| 23. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity Exploration from the Arctic to the Antarctic. Part 6: The Arctic Ocean-96 expedition
- 2015
-
Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:007, s. 1-22
-
Tidskriftsartikel (refereegranskat)abstract
- The Swedish Arctic Ocean-96 expedition arranged by the Swedish Polar Research Committee took place during 1996 with the Swedish icebreaker M/S Oden. The expedition focused on studying the distribution of radionuclides in different water masses in the central Arctic Ocean. The expedition crossed the Barents Sea, entered the Nansen Basin at the St. Anna Trough, and continued north across the Amundsen Basin. The main part of the expedition was concentrated on the north Lomonosov Ridge and the return route passed the North Pole and went south along 10 oE towards Svalbard. In both legs, water samples in the surface and subsurface layers were collected for the determination of fission products and transuranic elements in seawater and sediment. The highest 137Cs, 90Sr and 129l activities and 134Cs/137Cs activity ratios are found in a band stretching from the northern Lomonosov Ridge, over the North Pole and south along 10-15 oE to 85 oN. The releases from European nuclear fuel reprocessing plants and Chernobyl fallout traced by the 129I and 134Cs/137Cs signals respectively have approximately the same spatial distribution in the Arctic Ocean surface layer. The activity concentration of 90Sr in surface water is about 2 Bq.m-3. For 239+240Pu the lowest concentrations in the surface water of 4 mBq.m-3 was found on the Lomonosov Ridge and in the Makarov Basin. In the Eurasian Basin, the concentrations 239+240Pu are about 13 mBq.m-3 . For all the radionuclides analysed, the water profiles generally show activities decreasing with depth. An exception is the high 137Cs activity concentrations found in the lower halocline layer at the Lomonosov Ridge and Makarov Basin stations. The maxima were not observed in the 90Sr or l29l measurements. It is assumed to be due to a contribution of Chernobyl fallout to the Arctic Ocean surface layers in the years around 1990. Inventories down to 900 m death reveal that between 60-70 % of the 137Cs, 90Sr and in the Arctic Ocean water, are present in the surface layer inflow from the Atlantic. The total inventories down to 900 m in the Eurasian Basin of the Arctic Ocean estimate to 6.7 PBq for 137Cs, 3.4 PBq for 90Sr and 5.3x1028 atoms for 129l.
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| 24. |
- Roos, Björn, et al.
(författare)
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Exploring the actinide-actinide bond: Theoretical studies of the chemical bond in Ac-2, Th-2, Pa-2, and U-2
- 2006
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 128:51, s. 17000-17006
-
Tidskriftsartikel (refereegranskat)abstract
- Multiconfigurational quantum chemical methods (CASSCF/CASPT2) have been used to study the chemical bond in the actinide diatoms Ac-2, Th-2, Pa-2, and U-2. Scalar relativistic effects and spin-orbit coupling have been included in the calculations. In the Ac-2 and Th-2 diatoms the atomic 6d, 7s, and 7p orbitals are the significant contributors to the bond, while for the two heavier diatoms, the 5f orbitals become increasingly important. Ac-2 is characterized by a double bond with a (3)Sigma(-)(g)(0(g)(+)) ground state, a bond distance of 3.64. angstrom, and a bond energy of 1.19 eV. Th-2 has quadruple bond character with a D-3(g)(1(g)) ground state. The bond distance is 2.76 angstrom and the bond energy (D-0) 3.28 eV. Pa-2 is characterized by a quintuple bond with a (3)Sigma(-)(g)(0(g)(+)) ground state. The bond distance is 2.37 angstrom and the bond energy 4.00 eV. The uranium diatom has also a quintuple bond with a O-7(g) (8(g)) ground state, a bond distance of 2.43 angstrom, and a bond energy of 1.15 eV. It is concluded that the strongest bound actinide diatom is Pa-2, characterized by a well-developed quintuple bond.
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| 25. |
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| 26. |
- Roos, Björn, et al.
(författare)
-
Main group atoms and dimers studied with a new relativistic ANO basis set
- 2004
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 108:15, s. 2851-2858
-
Tidskriftsartikel (refereegranskat)abstract
- New basis sets of the atomic natural orbital (ANO) type have been developed for the main group and rare gas atoms. The ANO’s have been obtained from the average density matrix of the ground and lowest excited states of the atom, the positive and negative ions, and the dimer at its equilibrium geometry. Scalar relativistic effects are included through the use of a Douglas-Kroll Hamiltonian. Multiconfigurational wave functions have been used with dynamic correlation included using second-order perturbation theory (CASSCF/CASPT2). The basis sets are applied in calculations of ionization energies, electron affinities, and excitation energies for all atoms and the ground-state potentials for the dimers. These calculations include spin-orbit coupling using the RASSCF State Interaction (RASSI-SO) method. The spin-orbit splitting for the lowest atomic term is reproduced with an accuracy of better than 0.05 eV, except for row 5, where it is 0.15 eV. Ionization energies and electron affinities have an accuracy better than 0.2 eV, and atomic polarizabilities for the spherical atoms are computed with errors smaller than 2.5%. Computed bond energies for the dimers are accurate to better than 0.15 eV in most cases (the dimers for row 5 excluded).
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| 27. |
- Roos, Björn, et al.
(författare)
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New relativistic ANO basis sets for actinide atoms
- 2005
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 409:4-6, s. 295-299
-
Tidskriftsartikel (refereegranskat)abstract
- New basis sets of the atomic natural orbital (ANO) type have been developed for the actinide atoms Ac-Cm. The ANOs have been obtained from the average density matrix of the ground and lowest excited states of the atom, the positive ions, and the atom in a electric field. Scalar relativistic effects are included through the use of a Douglas-Kroll-Hess Hamiltonian. Multiconfigurational wave functions have been used with dynamic correlation included using second order perturbation theory (CASSCF/CASPT2). The basis sets are applied in calculations of ionization energies and some excitation energies. Computed ionization energies have an accuracy better than 0.2 eV in most cases. The lowest multiplet levels have been computed. These calculations include spin-orbit coupling using a variation-perturbation approach. The atomic polarizability of the spherically symmetric americium atom has been computed to be 116 au(3).
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| 28. |
- Roos, Björn, et al.
(författare)
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New relativistic ANO basis sets for transition metal atoms
- 2005
-
Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 109:29, s. 6575-6579
-
Tidskriftsartikel (refereegranskat)abstract
- New basis sets of the atomic natural orbital (ANO) type have been developed for the first, second, and third row transition metal atoms. The ANOs have been obtained from the average density matrix of the ground and lowest excited states of the atom, the positive and negative ions, and the atom in an electric field. Scalar relativistic effects are included through the use of a Douglas-Kroll-Hess Hamiltonian. Multiconfigurational wave functions have been used with dynamic correlation included using second order perturbation theory (CASSCF/CASPT2). The basis sets are applied in calculations of ionization energies, electron affinities, and excitation energies for all atoms and polarizabilities for spherically symmetric atoms. These calculations include spin-orbit coupling using a variation-perturbation approach. Computed ionization energies have an accuracy better than 0.2 eV in most cases. The accuracy of computed electron affinities is the same except in cases where the experimental values are smaller than 0.5 eV. Accurate results are obtained for the polarizabilities of atoms with spherical symmetry. Multiplet levels are presented for some of the third row transition metals.
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| 29. |
- Roos, Björn, et al.
(författare)
-
New Relativistic Atomic Natural Orbital Basis Sets for Lanthanide Atoms with Applications to the Ce Diatom and LuF3
- 2008
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 112:45, s. 11431-11435
-
Tidskriftsartikel (refereegranskat)abstract
- New basis sets of the atomic natural orbital (ANO) type have been developed for the lanthanide atoms La-Lu. The ANOs have been obtained from the average density matrix of the ground and lowest excited states of the atom, the positive ions, and the atom in an electric field. Scalar relativistic effects are included through the use of a Douglas-Kroll-Hess Hamiltonian. Multiconfigurational wave functions have been used with dynamic correlation included using second-order perturbation theory (CASSCF/CASPT2). The basis sets are applied in calculations of ionization energies and some excitation energies. Computed ionization energies have an accuracy better than 0.1 eV in most cases. Two molecular applications are inluded as illustration: the cerium diatom and the LuF3 molecule. In both cases it is shown that 4f orbitals are not involved in the chemical bond in contrast to an earlier claim for the latter molecule.
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| 30. |
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| 31. |
- Roos, Björn, et al.
(författare)
-
Relativistic quantum chemistry: the multiconfigurational approach
- 2004
-
Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 6:11, s. 2919-2927
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Tidskriftsartikel (refereegranskat)abstract
- A multiconfigurational approach to the quantum chemistry of heavy element compounds is described. Relativistic effects are treated in two steps, both based on the Douglas-Kroll Hamiltonian. Scalar terms are included in the basis set generation and are used to determine wave functions and energies, which include static (through the use of the CASSCF method) and dynamic correlation effects (using multiconfigurational perturbation theory, CASPT2). Spin-orbit coupling is treated in a configuration interaction model, which uses CASSCF wave functions as the basis states. The method is shown to work for all atoms of the periodic system, with the possible exception of the heavier fifth row main group atoms. Illustrative results are presented for the main group atoms (spin-orbit splittings), the electronic spectrum of the iridium atom, the ground state of Tl-2 and Pb-2, and for the electronic spectrum of PbO. Some applications in actinide chemistry are also discussed.
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| 32. |
- Roos, Björn, et al.
(författare)
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Theoretical characterization of the lowest-energy absorption band of pyrrole
- 2002
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 116:17, s. 7526-7536
-
Tidskriftsartikel (refereegranskat)abstract
- The lowest-energy band of the electronic spectrum of pyrrole has been studied with vibrational resolution by using multiconfigurational second-order perturbation theory (CASPT2) and its multistate extension (MS-CASPT2) in conjunction with large atomic natural orbital-type basis sets including Rydberg functions. The obtained results provide a consistent picture of the recorded spectrum in the energy region 5.5-6.5 eV and confirm that the bulk of the intensity of the band arises from a pipi(*) intravalence transition, in contradiction to recent theoretical claims. Computed band origins for the 3s,3p Rydberg electronic transitions are in agreement with the available experimental data, although new assignments are suggested. As illustrated in the paper, the proper treatment of the valence-Rydberg mixing is particularly challenging for ab initio methodologies and can be seen as the main source of deviation among the recent theoretical results as regards the position of the low-lying valence excited states of pyrrole. (C) 2002 American Institute of Physics.
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| 33. |
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| 34. |
- Roos, Åke
(författare)
-
Detaljstudie av Ljusnanåsen i Rengsjö socken, Gävleborgs län
- 1974
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Berggrunden i Gävleborgs län präglas av tre morfologiska formelement.I öster utbreder sig en kustslätt, i söder cirka 30 Km bred, som i norr löper utanför den nuvarande kustlinjen. Denna slätt utgör sannolikt en denudationsyta, ett S.K. peneplan, med låg topografi och med berget rikligt exponerat mellan sedimenten. Slätten utgör troligen en utlöpare av det subkambriska peneplanet, i söder väl utbildat i bl. a. uppland. Detta peneplan övergår inåt landet i ett höjdområde med bergsmassiv av ganska enhetlig toppkonstans, med vissa toppar överstigande denna nivå. Gränsen mellan slätten i söder och inlandets berg är utbildad som en brant, vars genes är omtvistad. Marin abrasion i kombination med andra morfologiska processer är närmast att förmoda.Gnejsgranit med stora fältspatsögon utgör den mest representerade bergarten i länt. Denna bergart uppträder i stora massiv. Ett bälte av kvartsit utgör berggrund vid gränsen till Västernorrland. I länets södra förekommer yngre granit, liksom i Orsa Finnmark i NW. Lågmetamorfa sedimentbergarter och massformiga, ibland skiffriga vulkanbergarter, S. K. Losgrönstenar finns inom samma område. Porfyrer sträcker sig in i flikar i detta område från Dalarna och Härjedalen. Jonisk sandsten finns Orsa Finnmark, liksom i Gävlesänkan i söder. Kambrosilurbergarter finns bara representerade som lösa block i de kvartära avlagringarna. Länets yngsta bergart är Dellenit, en andesit, som finns mellan Dellensjöarna i norr.Länets mest representerade jordart är, som i stort landet i övrigt, morän. Dess sammansättning är varierande, vad beträffar blockhalt och matrix. Normalblockig , sandig morän är vanligast. Moränens former är ofta i samstämmighet med den underliggande berggrundens former. Egenformer, i form av ändmoräner .m . ärsparsamt representerade. Isälvsavlagringarna är talrikt, i form av väl markerade åsryggar och deltan i HK-nivå. Under HK-nivå förekommer i åsarna ett antal sandfält med hittills ganska okänd genes. Svallmaterial förekommer ofta i de dalgånga, som i NW riktning drar inåt höglandet. Klapperfält omgärdar de höjder inom kustslätten, som har varit kraftigt exponerade, liksom öarna i det nuvarande kustbandet, Lera och främst mjäla utfyller de lägre liggande delarna av dalgångarna på kustslätten, liksom mindre områden längre in i landet. Mo blir rikligare representerad i sedimenten inom höglandet. Eoliska avlagringar är utbredda främst i södra delen av länet och i höglandet i nordväst. Sedimentslätterna är, med få undantag, torvfattiga.Isrörelsen har inom länet övergått från en i söder, kring Gävletrakten, mycket nordlig ritning till , kring Söderhamn, en tydlig avböjning mot NW och W. Räfflor vittnar om flera isrörelseriktningar, inalles tre , en första från WNW, en något senare från NW och en ung, främst representerad i kustzonen, från N och NE . Denna kuströrelse ställs i samband med en förmodad isoscillation i Gävletrakten.Den lokala undersökningen tillsammans med övriga resultat ger vid handen, att isen från en nordlig riktning i höjd med Söderhamn, ganska snabbt drar mot väster, samtidigt som iskanten dröjer i norra delen av länet. I höjd med kustslättens övergång i höglandet i W utjämnas denna rörelse, genom att recessionen hejdas i W av över HK uppdykande bergsområden. Isbrämet erhåller nu en jämnare linje i riktning SW-NE, och uppbrytningen tilltar krig kustöarna i NE. Isen ligger kvar i dalarna inåt, och i sprickor mellan bergshöjderna ansamlas stora material mängder. Isavsmältningen med dödisrester inom stora områden. Och med lateral dränering längs sprickor och tunnlar i dalsidorna.
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| 35. |
- Salomonsson, Emelie, et al.
(författare)
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Functional analyses of pilin-like proteins from Francisella tularensis : complementation of type IV pilus phenotypes in Neisseria gonorrhoeae
- 2009
-
Ingår i: Microbiology. - Berks : Society of general microbiology. - 1350-0872 .- 1465-2080. ; 155, s. 2546-2559
-
Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence from a number of studies strongly suggests that proteins orthologous to those involved in type IV pili (Tfp) assembly and function are required for Francisella pathogenicity. However, the molecular mechanisms by which the components exert their influence on virulence remain poorly understood. Owing to the conservation and promiscuity of Tfp biogenesis machineries, expression of Tfp pilins in heterologous species has been used successfully to analyse organelle structure-function relationships. In this study we expressed a number of Francisella pilin genes in the Tfp-expressing pathogen Neisseria gonorrhoeae lacking its endogenous pilin subunit. Two gene products, the orthologous PiIA proteins from Francisella tularensis subspecies tularensis and novicida, were capable of restoring the expression of Tfp-like appendages that were shown to be dependent upon the neisserial Tfp biogenesis machinery for surface localization. Expression of Francisella PiIA pilins also partially restored competence for natural transformation in N. gonorrhoeae. This phenotype was not complemented by expression of the PuIG and XcpT proteins, which are equivalent components of the related type II protein secretion system. Taken together, these findings provide compelling, although indirect, evidence of the potential for Francisella PiIA proteins to express functional Tfp.
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| 36. |
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| 37. |
- Shami, Annelie, et al.
(författare)
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Fibromodulin Deficiency Reduces Low-Density Lipoprotein Accumulation in Atherosclerotic Plaques in Apolipoprotein E-Null Mice.
- 2012
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1524-4636.
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to analyze how an altered collagen structure affects development of atherosclerotic plaques. METHODS AND RESULTS: Fibromodulin-null mice develop an abnormal collagen fibril structure. In apolipoprotein E (ApoE)-null and ApoE/fibromodulin-null mice, a shear stress-modifying carotid artery cast induced formation of atherosclerotic plaques of different phenotypes; inflammatory in low-shear stress regions and fibrous in oscillatory shear stress regions. Electron microscopy showed that collagen fibrils were thicker and more heterogeneous in oscillatory shear stress lesions from ApoE/fibromodulin-null mice. Low-shear stress lesions were smaller in ApoE/fibromodulin-null mice and contained less lipids. Total plaque burden in aortas stained en face with Oil Red O, as well as lipid accumulation in aortic root lesions, was also decreased in ApoE/fibromodulin-null mice. In addition, lipid accumulation in RAW264.7 macrophages cultured on fibromodulin-deficient extracellular matrix was decreased, whereas levels of interleukin-6 and -10 were increased. Our results show that an abnormal plaque collagen fibril structure can influence atherosclerotic plaque development. CONCLUSIONS: The present findings suggest a more complex role for collagen in plaque stability than previously anticipated, in that it may promote lipid-accumulation and inflammation at the same time as it provides mechanical stability.
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| 38. |
- Svenson, Ulrika, et al.
(författare)
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Telomere length in peripheral leukocytes is associated with immune cell tumor infiltration and prognosis in colorectal cancer patients
- 2016
-
Ingår i: Tumor Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 37:8, s. 10877-10882
-
Tidskriftsartikel (refereegranskat)abstract
- Telomeres are protective structures at the end of chromosomes, essential for chromosomal integrity. A large number of studies have investigated leukocyte telomere length as a possible risk marker for various cancers, colorectal cancer (CRC) included. In contrast, studies investigating leukocyte telomere length in relation to CRC survival are lacking. We previously reported that relative telomere length (RTL) of leukocytes collected at diagnosis predicted survival in patients with breast and kidney cancer. We suggested that these findings might reflect various immunological mechanisms, affected by the presence of a tumor. In the present study, leukocyte RTL was examined in relation to immune cell tumor infiltration and prognosis in 130 patients with CRC diagnosis. RTL was measured with a well-established qPCR method. We found that patients with the highest degree of lymphocyte tumor infiltration had shorter leukocyte RTL. Consistent with our previous findings, short RTL was a favorable prognostic marker in univariate survival analysis. In the current study, RTL did not remain as an independent predictor in multivariate survival analysis, when including metastatic status in the model. However, a non-significant trend towards a similar telomere-associated survival pattern was observed in patients with limited disease. In contrast, for patients who died of other causes than CRC, short RTL was associated with significantly shorter survival time. To our knowledge, this is the first study to investigate an association between leukocyte RTL, immune cell tumor infiltration, and cancer-specific survival in CRC patients. Larger studies are warranted to verify these findings.
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| 39. |
- Thurfjell, Niklas, et al.
(författare)
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Function and importance of p63 in normal oral mucosa and squamous cell carcinoma of the head and neck.
- 2005
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Ingår i: Advances in Oto-Rhino-Laryngology. - Basel : KARGER. - 0065-3071 .- 1662-2847. ; 62, s. 49-57
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Squamous cell carcinoma of the head and neck (HNSCC) is the 6th most common malignancy worldwide with a 5-year survival that has not improved over the last 20-25 years. Factors of prognostic significance for this tumour type include the presence of regional lymph node metastasis and amplification of chromosome 3q21-29, where the p63 gene is located. This gene encodes 6 proteins and is crucial for formation of the oral mucosa, teeth, salivary glands and skin. Each of the 6 different p63 proteins has different characteristics and functions, where some resemble the tumour suppressor protein p53, whilst others have functions that oppose p53. METHODS: To understand the function and importance of p63 in oral mucosa and tumour development we have studied protein as well as mRNA expression in normal oral mucosa and tumours. RESULTS/CONCLUSION: Expression of p63 proteins differs between the cell layers in normal oral mucosa, and primary HNSCC has a high expression level of p63 isoforms normally expressed in basal cells. Data suggest that p63 expression in HNSCC influences tumour cell differentiation.
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| 40. |
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| 41. |
- Veryazov, Valera, et al.
(författare)
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How to Select Active Space for Multiconfigurational Quantum Chemistry?
- 2011
-
Ingår i: International Journal of Quantum Chemistry. - : Wiley. - 0020-7608. ; 111:13, s. 3329-3338
-
Tidskriftsartikel (refereegranskat)abstract
- Bjorn Roos is one of the pioneers in the development and usage of multiconfigurational methods, in particular, the complete active space self-consistent field method and the perturbational complete active space perturbation theory through second order. To perform multiconfigurational calculations using these methods, a set of active orbitals must be selected, and the success of the methods depends on the choice of this set. This is not only sometimes easy but also sometimes difficult, especially for use of the more recent RASSCF and RASPT2 methods (which use a "restricted active space" rather than the complete one). Although an automated procedure for selecting the active orbitals would be a preferable solution, this does not seem feasible yet. An account of the problem is given, with examples and some approaches that usually work. (C) 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111: 3329-3338, 2011
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| 42. |
- Wang, Xuefeng, et al.
(författare)
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Experimental and Theoretical Investigation of Simple Terminal Group 6 Arsenide As MF3 Molecules
- 2009
-
Ingår i: The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory. - : American Chemical Society (ACS). - 1520-5215. ; 113:21, s. 6064-6069
-
Tidskriftsartikel (refereegranskat)abstract
- Laser-ablated group 6 metal atoms react with NF3 and PF3 to form the simple lowest energy N MF3 and P=MX3 products, and this investigation has been extended to AsF3. Mo and W atoms react with AsF3 upon excitation by laser ablation or UV irradiation to form stable trigonal As MF3 terminal arsenides. These molecules are identified by comparison of the closely related infrared spectra of the analogous phosphide species and with frequencies calculated by density functional theory and multiconfigurational second order perturbation theory (CASSCF/CASPT2). Computed CASSCF/CASPT2 triple bond lengths for the As MoF3 and As WF3 molecules are 2.240 angstrom and 2.250 angstrom, respectively. The natural bond orders calculated by CASSCF/CASPT2 decrease from 2.67 to 2.60 for P MoF3 to As MoF3 and from 2.74 to 2.70 for P WF3 to As WF3 as the arsenic valence orbitals are less effective than those of phosphorus in bonding to each metal atom and the larger metal orbital size becomes more compatible with the arsenic valence orbitals. The Cr atom reaction gives the arsinidene AsF=CrF2 product instead of the higher energy As CrF3 molecule as the Cr (VI) state is not supported by the softer pnictides.
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| 43. |
- Wang, Xuefeng, et al.
(författare)
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Infrared Spectra and Quantum Chemical Calculations of the Uranium Carbide Molecules UC and CUC with Triple Bonds.
- 2010
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 132, s. 8484-8488
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Tidskriftsartikel (refereegranskat)abstract
- Laser evaporation of carbon-rich uranium/carbon alloys followed by atom reactions in a solid argon matrix and trapping at 8 K gives weak infrared absorptions for CUO at 852 and 804 cm−1. A new band at 827 cm−1 becomes a doublet with mixed carbon 12 and 13 isotopes and exhibits the 1.0381 isotopic frequency ratio, which is appropriate for the UC diatomic molecule, and another new band at 891 cm−1 gives a three-band mixed isotopic spectrum with the 1.0366 isotopic frequency ratio, which is characteristic of the linear CUC molecule. CASPT2 calculations with dynamical correlation find the C≡U≡C ground state as linear 3Σu+ with 1.840 Å bond length and molecular orbital occupancies for an effective bond order of 2.83. Similar calculations with spin-orbit coupling show that the U≡C diatomic molecule has a quintet (Λ = 5, Ω = 3) ground state, a similar 1.855 Å bond length, and a fully developed triple bond of 2.82 effective bond order.
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