Biomedical subjects

Ingmar Persson

Publications and source records attributed to Ingmar Persson.

25 records · Page 2Linked to original sources

PubMed2002

Human death--a view from the beginning of life.

This paper presents a simple argument against definitions of the death of a human being in terms of death, or the cessation of functioning, of its brain: a human being is alive, and is capable of dying, before it acquires a brain. Although a more accurate definition is sketched, it is stressed that it should not be taken for granted that it is ethically urgent to work out such a definition. What morally matters more than the death of a human being may be something for which its death is sufficient, but not necessary, namely the irreversible loss of its capacity for consciousness. It is when we lose this capacity that we lose our moral standing, as subjects who can be benefited and harmed, and who can have rights. But, as is also suggested, the loss of this capacity is ill suited to be what the death of a human being definitionally consists of.

Beginning of Human Life↗

PubMed1999

Harming the non-conscious.

Peter Singer has argued that nothing done to a fetus before it acquires consciousness can harm it. At the same time, he concedes that a child can be harmed by something done to it when it was a non-conscious fetus. But this implies that the non-conscious fetus can be harmed. The mistake lies in thinking that, since existence can be instrinsically bad for a being only if it is conscious, it can be harmed only if it is conscious. In fact, its being harmed only implies that it could have been conscious (and led a good life).

Abortion, Induced↗

PubMed1998

The Structure of the Hydrated Gallium(III), Indium(III), and Chromium(III) Ions in Aqueous Solution. A Large Angle X-ray Scattering and EXAFS Study.

The structure of the hydrated gallium(III), indium(III), and chromium(III) ions has been determined in aqueous perchlorate and nitrate solutions by means of the large-angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) techniques. The EXAFS studies have been performed over a wide concentration range, 0.005-1.0 mol.dm(-)(3) (2.6 mol.dm(-)(3) for chromium(III)), while the LAXS studies are restricted to concentrated solutions, ca. 1.5 mol.dm(-)(3). All three metal ions were found to coordinate six water molecules, each of which are hydrogen bonded to two water molecules in a second hydration sphere. The metal-oxygen bond distance in the first hydration sphere of the gallium(III), indium(III), and chromium(III) ions was determined by LAXS and EXAFS methods to be 1.959(6), 2.131(7), and 1.966(8) Å. The LAXS data gave mean second sphere M.O distances of 4.05(1), 4.13(1), and 4.08(2) Å for the gallium(III), indium(III), and chromium(III) ions, respectively. The perchlorate ion was found to be hydrogen bonded to 4.5(7) water molecules with the O.O distance 3.05(2) Å and Cl.O 3.68(3) Å. Analyses of the Ga, In, and Cr K-edge EXAFS data of the aqueous perchlorate and nitrate solutions showed no influence on the first shell M-O distance by a change of concentration or anion. The minor contribution from the second sphere M.O distance is obscured by multiple scattering within the tightly bonded first shell. EXAFS data for the alum salts CsM(SO(4))(2).12H(2)O, M = Ga or In, showed the M-O bond length of the hexahydrated gallium(III) and indium(III) ions to be 1.957(2) and 2.122(2) Å, respectively.

Journal Article↗

PubMed1997

Crystal Structure of N,N-Dimethylthioformamide Solvates of the Divalent Group 12 Ions with Linear Coordination Geometry for Mercury(II), Tetrahedral for Zinc(II), and Octahedral for Cadmium(II).

The crystalline solvates of the divalent group 12 metal ions with the soft sulfur donor N,N-dimethylthioformamide display an unusual variation in coordination number and geometry with two, four, and six ligands attached to the mercury(II), zinc(II), and cadmium(II), ions, respectively. Bis(N,N-dimethylthioformamide)mercury(II) perchlorate precipitates from acetonitrile solution when adding less than 2 equiv of N,N-dimethylthioformamide, while the zinc and cadmium solvates crystallize from saturated N,N-dimethylthioformamide solutions. The disolvate [Hg(SCHN(CH(3))(2))(2)](ClO(4))(2) crystallizes in the monoclinic space group P2(1)/n (No. 14) with a = 6.208(1) Å, b = 15.239(7) Å, c = 8.681(2) Å, beta = 99.30(3) degrees, and Z = 2. Centrosymmetric mercury(II) complexes with strong collinear bonds to two N,N-dimethylthioformamide molecules, Hg-S 2.350(2) Å, are joined by double bridges of perchlorate ions in chains along the a-axis by four weak interactions between the mercury and the perchlorate oxygen atoms, mean Hg-O distance 2.84 Å. Tetrakis(N,N-dimethylthioformamide)zinc trifluoromethanesulfonate, [Zn(SCHN(CH(3))(2))(4)](CF(3)SO(3))(2), crystallizes in the triclinic space group P&onemacr; (No. 2) with a = 10.487(3) Å, b = 12.910(3) Å, c = 13.489(5) Å, alpha = 68.800(4) degrees, beta = 69.260(4) degrees, gamma = 74.06(1) degrees, and Z = 2, with the zinc ions tetrahedrally surrounded by four N,N-dimethylthioformamide ligands, mean Zn-S distance 2.34 Å. Also the cadmium solvate of corresponding composition, [Cd(SCHN(CH(3))(2))(4)(CF(3)SO(3))(2)], crystallizes in the space group P&onemacr;, with a = 8.670(1) Å, b = 9.529(1) Å, c = 10.685(1) Å, alpha = 75.20(1) degrees, beta = 66.97(1) degrees, gamma = 65.31(1) degrees, and Z = 1, although the structure comprises centrosymmetric tetrakis(N,N-dimethylthioformamide)bis(trifluoromethanesulfonato)cadmium(II) complexes in which four Cd-S bonds (mean 2.65 Å) and two weaker Cd-O bonds at 2.470(2) Å to the trifluoromethanesulfonate ions give rise to a pseudo-octahedral coordination around the cadmium ion. When using perchlorate instead as counterion, hexakis(N,N-dimethylthioformamide)cadmium perchlorate, [Cd(SCHN(CH(3))(2))(6)](ClO(4))(2), crystallizes in the space group P2(1)/n with a = 12.757(1) Å, b = 7.4681(6) Å, c = 19.732(2) Å, beta = 96.31(1) degrees, and Z = 2. The mean Cd-S bond distance increases to 2.715 Å in the fully solvated cadmium ion with almost regular octahedral coordination geometry to its six centrosymmetrically related ligands. The effect of the weak internal hydrogen bonding occuring between the hydrogen atom of a -CHS group and the sulfur atom of neighboring N,N-dimethylthioformamide ligands is discussed.

Journal Article↗

PubMed1997

Structure of the Solvated Zinc(II), Cadmium(II), and Mercury(II) Ions in N,N-Dimethylthioformamide Solution.

By means of large-angle X-ray scattering zinc(II) and mercury(II) ions in N,N-dimethylthioformamide solution are found to coordinate to four N,N-dimethylthioformamide molecules with Zn-S and Hg-S bond distances of 2.362(5) and 2.527(6) Å, respectively. The intermediate divalent ion in group 12, cadmium, is solvated by six N,N-dimethylthioformamide molecules with a Cd-S bond distance of 2.69(1) Å. Raman and far-infrared spectra have been recorded and assigned for the solvated ions both in solution and in the solid state. The character of the bonds to the metal ion is discussed in order to explain the lower coordination numbers of the zinc and mercury(II) ions.

Journal Article↗

PubMed1997

Genetic therapy, person-regarding reasons and the determination of identity -- a reply to Robert Elliot.

I have outlined two ways of defending the claim that there are so-called person-regarding reasons for practising gene therapy on human conceptuses. One is metaphysical and concerns our nature and identity. The upshot of it is that, in cases of most interest, this therapy does not affect our identity, by bringing into existence anyone of our kind who would not otherwise have existed. The other defence is value theoretical and claims that even if genetic therapy were to affect the identity of beings of our kind, there could still be person-regarding reasons for performing it, since we can be benefited and harmed by being caused to exist or not to exist. Robert Elliot has attacked both of these lines, and my present objective is to show how his criticisms can be deflected.

Altruism↗

PubMed1995

Genetic therapy, identity and the person-regarding reasons.

It has been argued that there can be no person-regarding reasons for practising genetic therapy, since it affects identity and causes to exist an individual who would not otherwise have existed. And there can be no such reasons for causing somebody to exist because existing cannot be better for an individual than never existing. In the present paper, both of these claims are denied. It is contended, first, that in practically all significant cases genetic therapy will not affect the identity of beings of our kind. This is so irrespective of whether, essentially, we are beings with minds or beings of a certain biological species, the human one. Second, it is contended that, even if genetic therapy were to affect our identity, there could be person-regarding reasons for conducting it, for existence can be better than non-existence for the individual.

Beginning of Human Life↗