| 1. |
- Lindh, Roland, 1958-, et al.
(författare)
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The reduced multiplication scheme of the Rys quadrature and new recurrence relations for auxiliary function based two‐electron integral evaluation
- 1991
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 95:8, s. 5889-5897
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Tidskriftsartikel (refereegranskat)abstract
- The reduced multiplication scheme of the Rys quadrature is presented. The method is based on new ways in which the Rys quadrature can be developed if it is implemented together with the transfer equation applied to the contracted integrals. In parallel to the new scheme of the Rys quadrature improvements are suggested to the auxiliary function based algorithms. The two new methods have very favorable theoretical floating point operation (FLOP) counts as compared to other methods. It is noted that the only significant difference in performance of the two new methods is due to the vectorizability of the presented algorithms. In order to exhibit this, both methods were implemented in the integral program SEWARD. Timings are presented for comparisons with other implementations. Finally, it is demonstrated how the transfer equation in connection with the use of spherical harmonic Gaussians offers a very attractive path to compute the two-electron integrals of such basis functions. It is demonstrated both theoretically and with actual performance that the use of spherical harmonic Gaussians offers a clear advantage over the traditional evaluation of the two-electron integrals in the Cartesian Gaussian basis.
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| 2. |
- Ryu, U, et al.
(författare)
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An efficient method of implementing the horizontal recurrence relation in the evaluation of electron repulsion integrals using Cartesian Gaussian functios
- 1991
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 185:5-6, s. 562-568
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Tidskriftsartikel (refereegranskat)abstract
- The tree search problem is considered for optimizing the horizontal recurrence relation step, which is a three-dimensional recurrence relation used in generating two-electron integrals. By eliminating redundant work, it is possible to achieve 13%, 25%, 38% and 44% savings in floating point operations and 21%, 34%, 46% and 53% reductions in memory requirements for the (ff\textbackslashff), (gg\textbackslashgg), (hh\textbackslashhh) and (ii\textbackslashii) cases, respectively. These savings and reductions will lead to quite efficient two-electron integral and derivative programs when high angular momentum functions are included.
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| 3. |
- Shev, S, et al.
(författare)
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Second-generation hepatitis C Elisa antibody tests confirmed by the four-antigen recombinant immunoblot assay correlate well with hepatitis C viremia and chronic liver disease in Swedish blood donors
- 1993
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Ingår i: Vox Sanguinis. - 1423-0410. ; 65:1, s. 32-37
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Tidskriftsartikel (refereegranskat)abstract
- Seventy-three Swedish blood donors (52 men, 21 women; median age 36 years) repeatedly reactive for hepatitis C antibodies (anti-HCV C-100-3) were tested with a second-generation (2nd-gen) anti-HCV Elisa and a 4-band recombinant immunoblot assay (RIBA 2). These results were correlated to serum alanine aminotransferase (S-ALAT), liver morphology and viremia as detected by 'nested' polymerase chain reaction (PCR) based on primers from a 5'-noncoding sequence of the HCV genome. Thirty-five of 46 (76%) donors with positive 2nd-gen Elisa tests confirmed by RIBA 2 were PCR positive whereof 27 had histological findings compatible with chronic persistent hepatitis (CPH) and 7 had chronic active hepatitis (CAH). Ten of 56 (18%) 2nd-gen Elisa-positive donors were RIBA 2 negative (or indeterminate) and none of these had chronic hepatitis nor were PCR positive. Seventeen of 73 (23%) donors were 1st-gen Elisa positive but 2nd-gen Elisa negative. All of these were PCR negative and only 1 (6%) had chronic hepatitis (CPH). An elevated S-ALAT level (reference < 0.7 mu kat/l) was found in 26 2nd-gen Elisa and RIBA 2-positive donors of which 18 had CPH and 7 had CAH and all 25 were PCR positive. A normal S-ALAT level was found in 9 of 34 (26%) donors with chronic hepatitis (all had CPH) and positive PCR. We have found that blood donors with positive 2nd-gen anti-HCV Elisa tests confirmed by RIBA-2 and especially with a concomitant elevated S-ALAT are highly likely to be viremic as demonstrated by PCR and to have chronic hepatitis.
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