| 1. |
- Gustafsson, Agnetha, et al.
(författare)
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Evaluation of various attenuation corrections in lung SPECT in healthy subjects
- 2003
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Ingår i: Nuclear Medicine Communications. - : Ovid Technologies (Wolters Kluwer Health). - 0143-3636 .- 1473-5628. ; 24:10, s. 1087-1095
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Tidskriftsartikel (refereegranskat)abstract
- The effect of increasingly more sophisticated attenuation correction methods on image homogeneity has been studied in seven healthy subjects. The subjects underwent computed tomography (CT), single photon emission computed tomography (SPECT) and transmission computed tomography (TCT) of the thorax region in the supine position. Density maps were obtained from the CT and TCT studies. Attenuation corrections were performed using five different methods: (1) uniform correction using only the body contour; (2) TCT based corrections using the average lung density; (3) TCT based corrections using the pixel density; (4) CT based corrections using average lung density; and (5) CT based corrections using the pixel density. The isolated attenuation effects were assessed on quotient images generated by the division of images obtained using various attenuation correction methods divided by the non-uniform attenuation correction based on CT pixel density (reference method). The homogeneity was calculated as the coefficient of variation of the quotient images (CVatt), showing the isolated attenuation effects. Values of CVatt were on average 12.8% without attenuation correction, 10.7% with the uniform correction, 8.1% using TCT map using the average lung density value and 4.8% using CT and average lung density corrections. There are considerable inhomogeneities in lung SPECT slices due to the attenuation effect. After attenuation correction the remaining inhomogeneity is considerable and cannot be explained by statistical noise and camera non-uniformity alone. ((C) 2003 Lippincott Williams Wilkins).
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| 2. |
- Jacobsson, Micael, et al.
(författare)
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Improving structure-based virtual screening by multivariate analysis of scoring data
- 2003
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 46:26, s. 5781-5789
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Tidskriftsartikel (refereegranskat)abstract
- hree different multivariate statistical methods, PLS discriminant analysis, rule-based methods, and Bayesian classification, have been applied to multidimensional scoring data from four different target proteins: estrogen receptor alpha (ERalpha), matrix metalloprotease 3 (MMP3), factor Xa (fXa), and acetylcholine esterase (AChE). The purpose was to build classifiers able to discriminate between active and inactive compounds, given a structure-based virtual screen. Seven different scoring functions were used to generate the scoring matrices. The classifiers were compared to classical consensus scoring and single scoring functions. The classifiers show a superior performance, with rule-based methods being most effective. The precision of correctly predicting an active compound is about 90% for three of the targets and about 25% for acetylcholine esterase. On the basis of these results, a new two-stage approach is suggested for structure-based virtual screening where limited activity information is available.
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| 3. |
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| 4. |
- Jacobsson, Mårten, et al.
(författare)
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Synthesis of naphthoxylosides on solid support
- 2002
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Ingår i: Tetrahedron Letters. - 0040-4039. ; 43:37, s. 6549-6552
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate the selective antiproliferative effects shown by 2-(6-hydroxynaphthyl)-beta-D-xylopyranoside the 14 possible beta-D-xylopyranosidic compounds were synthesized on solid support. An aminomethylated polystyrene resin was converted into an acid chloride resin and then esterified using dihydroxynaphthalene. The free hydroxy group was then xylosylated Under BF3.OEt2 mediated conditions. The xyloside was deprotected and simultaneously cleaved off the resin Using NaOMe/MeOH. Final purification using reverse phase HPLC gave the pure xylosides in 6-42% yield with Virtually no formation of alpha-xylosides. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 5. |
- Jacobsson, Ulf, et al.
(författare)
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12th comparison between the Swedish National Kilogram and SP's principal kilogram mass standards.
- 2004
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Rapport (refereegranskat)abstract
- The 12th comparison between the Swedish National Platinum-Iridium kilogram (Proto¬type number 40) and the principal kilogram standards for mass has been performed at SP Swedish National Testing and Research Institute. The method used was a weighted least square method with restraint developed by Dr Leslie Pendrill < >. Weighings for the pan-European key intercomparisons for 1 kg, EUROMET 509 and 510 were made together with the regular kilogram comparison.
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| 6. |
- Jacobsson, Ulf, et al.
(författare)
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Determination of the magnetic properties of mass standards.
- 2004
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Rapport (refereegranskat)abstract
- Magnetic forces can adversely affect weighings since, without systematic investigation, these spurious forces cannot be distinguished from the gravitational forces to be compared in the determination of mass. Magnetic forces can result from the mutual interaction of two mass standards as well as between a mass standard and the mass comparator being used for the weighing. Magnetic forces arise in the influence of a magnetic field gradient on a mass standard possessing a magnetic dipole moment; the latter may either exist permanently or may be induced by the applied magnetic field. This report summarises the effects of magnetism in weighing and methods developed to determine the magnetic properties of mass standard and comparator.
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| 7. |
- Kero, Anneli, 1950-, et al.
(författare)
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Legal abortion : a painful necessity
- 2001
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Ingår i: Social Science and Medicine. - 0277-9536 .- 1873-5347. ; 53:11, s. 1481-1490
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to increase knowledge about the psychosocial background and current living conditions of Swedish women seeking abortion, along with their motives for abortion and their feelings towards pregnancy and abortion. Two hundred and eleven women answered a questionnaire when they consulted the gynaecologist for the first time. The study indicates that legal abortion may be sought by women in many circumstances and is not confined to those in special risk groups. For example, most women in the sample were living in stable relationships with adequate finances. The motives behind a decision to postpone or limit the number of children revealed a wish to have children with the right partner and at the right time in order to combine good parenting with professional career. The study shows that prevailing expectations about lifestyle render abortion a necessity in family planning. One-third of the women had had a previous abortion(s) and 12% had become pregnant in a situation where they had felt pressured or threatened by the man. Two-thirds of the women characterised their initial feelings towards the pregnancy solely in painful words while nearly all the others reported contradictory feelings. Concerning feelings towards the coming abortion, more than half expressed both positive and painful feelings such as anxiety, relief, grief, guilt, anguish, emptiness and responsibility, while one-third expressed only painful feelings. However, almost 70% stated that nothing could change their decision to have an abortion. Thus, this study highlights that contradictory feelings in relation to both pregnancy and the coming abortion are common but are very seldom associated with doubts about the decision to have an abortion.
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