| 231. |
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| 232. |
- Persson, Bertil
(författare)
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Fuktsäkra betongbjälklag
- 1994
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Ingår i: Betong. - 1101-9190. ; :3, s. 14-16
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 233. |
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| 234. |
- Persson, Bertil
(författare)
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Migrän : Genetiskt inflytande, uppväxtförhållanden och personlighet i migränfamiljen
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The monograph consists of an extensive survey of psychological and behavioral genetic research on migraine, reports of three empirical studies in this area and an extensive English summary. Study 1 indicated persons with migraine (n=28) drawn from a neurological clinic to have experienced negative psychosocial events to a significantly greater extent during their development than persons free of migraine in general population (n=28) had. In study 2, part 1 involving 30 subjects with migraine 87% reported stress as a major migraine trigger (the headache often appeared after stress). Study 2, part 2, a family history study showed there to be a significantly greater prevalence of migraine (27%) among the siblings of the same 30 migraine subjects than among the siblings of 30 migraine-free controls drawn from the general population (10%). This result suggests the heritability of migraine, although the high discordance found also points to the importance of the within-family environment. Study 3, part 1, involving 30 sibling pair in which the one had migraine (migraine sibling) and the other was migraine-free and use of various personality instruments (Eysenck Personality Inventory, EPI; Coulour Word Test, CWT; Visual Aftereffects, VAE; Meta Contrast Technigue, MCT; and Ceasarec-Markes Personality Schedule, CMPS) showed the migraine siblings to score significantly higer on neuroticism (EPI), to be more sensitive (MCT; EPI) to disply signs of greater anxiety (VAE; CWT) and to report greater scarcity of friends during childhood and less verbal as well as nonverbal encouragement from their parents, than the migraine-free siblings. Neuroticism was found to correlate significantly with migraine, but not with headache frequency or severity in the migraine group. It is argued that, due to the high neuroticism of migrainics, psychotherapy should be considered as an alternative to other prophylactic treatments such as use of beta-adrenoceptor blockers, although the acute onset should be pharmacologically treated. Study 3, part 2, employed a special developed Sibling Behavioral Genetic Method (SBM) involving participants of 30 full sibling pairs, one sibling with and the other without migraine, and also a new pairing of the same subjects so as to produce genetically unrelated pairs (again one with and the other without migraine). Both groups were approximately similar on factors such as SES, age, gender, grade and sixe of the maily. A certain model was applied to test an additive genetic hypothesis. Out of 21 personality factors sensitivity (MCT), achievement (CMPS), extraversion-introversion (EPI), aggression (CMPS), anxiety (CWT), guilt-feelings, exhibition and succorance (CMPS) fit the model assuming additive genetic influences. However, within family environment appeared to be the major source of variance for most of the traits. Neuroticism (EPI), anxiety (MCT) and defense of status (CMPS) could be accounted for socioeconomic status (SES). The results also supported the assumption thatgenetically related siblings reared together experience quite different envoronments, as different in fact as the genetically unrelated controls.
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| 235. |
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| 236. |
- Persson, Bertil
(författare)
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Psykoterapi mot migrän
- 1994
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Ingår i: Psykologtidningen. - 0280-9702. ; 10, s. 17-17
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Abstract in Undetermined Resultat visar att aga och känslokyla hade förekommit i större utsträckning i migränikernas uppväxtmiljö, skriver Bertil Persson, Psykologiska institutionen i Lund, apropå sin avhandling om genetiskt inflytande, uppväxtförhållanden och personlighet i migränfamiljen.
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| 237. |
- Salford, Leif G., et al.
(författare)
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Permeability of the blood‐brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz
- 1994
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Ingår i: Microscopy Research and Technique. - : Wiley. - 1059-910X .- 1097-0029. ; 27:6, s. 535-542
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Tidskriftsartikel (refereegranskat)abstract
- Biological effects of electromagnetic fields (EMF) on the blood‐brain barrier (BBB) can be studied in sensitive and specific models. In a previous investigation of the permeability of the blood‐brain barrier after exposure to the various EMF‐components of proton magnetic resonance imaging (MRI), we found that the exposure to MRI induced leakage of Evans Blue labeled proteins normally not passing the BBB of rats [Salford et al. (1992), in: Resonance Phenomena in Biology, Oxford University Press, pp. 87–91]. In the present investigation we exposed male and female Fischer 344 rats in a transverse electromagnetic transmission line chamber to microwaves of 915 MHz as continuous wave (CW) and pulse‐modulated with repetition rates of 8, 16, 50, and 200 s−1. The specific energy absorption rate (SAR) varied between 0.016 and 5 W/kg. The rats were not anesthetized during the 2‐hour exposure. All animals were sacrificed by perfusion‐fixation of the brains under chloral hydrate anesthesia about 1 hour after the exposure. The brains were perfused with saline for 3–4 minutes, and thereafter fixed in 4% formaldehyde for 5–6 minutes. Central coronal sections of the brains were dehydrated and embedded in paraffin and sectioned at 5 μm. Albumin and fibrinogen were demonstrated immunohistochemically. The results show albumin leakage in 5 of 62 of the controls and in 56 of 184 of the animals exposed to 915 MHz microwaves. Continuous wave resulted in 14 positive findings of 35, which differ significantly from the controls (P = 0.002). With pulsed 915 MHz microwaves with repetition rates of 200, 50, 16, and 8 s−1, 42 of 149 were positive, which is highly significant at the P = 0.001 level. This reveals that both CW and pulsed 915 MHz microwaves have the potential to open up the BBB for albumin passage. However, there is no significant difference between continuous and pulsed 915 MHz microwaves in this respect. The frequency of occurrence of extravasates (26%) was found to be independent of SAR for SAR < 2.5 W/kg, but rose significantly for the higher SAR values (to 43%). The question of whether the opening of the blood‐brain barrier constitutes a health hazard demands further investigation. © 1994 Wiley‐Liss, Inc.
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| 238. |
- Ceberg, Crister, et al.
(författare)
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Neutron capture imaging of 10B in tissue specimens
- 1993
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Ingår i: Radiotherapy and Oncology. - 1879-0887. ; 26:2, s. 139-146
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Tidskriftsartikel (refereegranskat)abstract
- Boron Neutron Capture Therapy (BNCT) is an attractive concept for radiation treatment of malignant tumours. The patients receive a 10B-carrying compound with selective uptake in tumour cells, after which they are irradiated with epithermal neutrons. Theoretically, the tumour cells are killed by the high-LET particles produces in 10B(n, alpha)7Li reactions inside or close to the cell nucleus, while healthy brain cells with no boron uptake will be spared. In practice, a successful BNCT depends on the actual boron-distribution in the tissue, and consequently a new boron-compound aimed for BNCT must undergo detailed bio-distribution studies before clinical trials. In experimental work there is accordingly a great need for methods for quantitative bio-distribution measurements in tissue samples. In this paper we present an improved technique for neutron activated autoradiography providing quantitative boron images of freeze-sectioned tissue specimens from highly malignant rat brain gliomas. Particular attention has been paid to the correlation with the morphology of the specimens and to the altered self-absorption properties due to freeze-drying. A self-absorption correction factor for tumour tissue has been experimentally determined.
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| 239. |
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| 240. |
- Persson, Bertil, et al.
(författare)
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Basic creep of high-strength concrete at early ages
- 1993
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Ingår i: Creep and shrinkage of concrete : proceedings of the fifth International RILEM Symposium / RILEM proceedings 22. - 0419186301 ; , s. 523-528
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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