| 1. |
- Belichenko, P, et al.
(författare)
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Dendritic morphology in epileptogenic cortex from TRPE patients, revealed by intracellular Lucifer Yellow microinjection and confocal laser scanning microscopy.
- 1994
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Ingår i: Epilepsy research. - 0920-1211. ; 18:3, s. 233-47
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Tidskriftsartikel (refereegranskat)abstract
- Biopsy material was obtained from cortical epileptogenic zones (eight temporal, one occipital, one parietal and one frontal) of eleven patients aged 1.5-47 years with therapy-resistant partial epilepsy (TRPE) undergoing epilepsy surgery. Control autopsy material (two temporal, two occipital, one parietal and one frontal) was removed from six neurologically healthy cases within 6-10 hours postmortem delay. In each specimen, 100-300 pyramidal and non-pyramidal neurons were visualized by intracellular Lucifer Yellow microinjection. Single neurons were imaged using CLSM generated serial optical sections; 2-D reconstruction of each neuron was made using z-projection of serial optical images, and 3-D reconstructions and rotations were computerized. Neuronal maps from TRPE biopsies, compared to control autopsies, show markedly increased numbers of dendritic abnormalities of single pyramidal and non-pyramidal neurons in layers I, II-III, V-VII, and in the subcortical white matter. The abnormalities include: (1) increased number of non-pyramidal cells in layer I; (2) many pyramidal cells with two or three dendrites originating apically, rather than one single apical dendrite, in layers II-III; (3) atypical orientation of oblique apical and basal dendrites in pyramidal neurons of layers II-VII; (4) increased number of atypical 'dinosaur-like' and fusiform cells in layers V-VII; (5) numerous neurons in the white matter. These abnormalities may be etiological in cases with early onset, and predisposing in cases with late onset.
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| 2. |
- Smith, M.L., et al.
(författare)
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Heme-protein fission under non-denaturing conditions
- 1991
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 88:3, s. 882-886
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Tidskriftsartikel (refereegranskat)abstract
- Slow heme transfer from horseradish peroxidases C2 and A2, cytochrome c peroxidase, chloroperoxidase, and leghemoglobins to a heme acceptor protein, apomyoglobin, has been studied under mild conditions. The reaction is best described as heme release into water followed by quick engulfment by apomyoglobin. The energetics of the activated process are large and interpreted as connected to both polypeptide motions during release and the ordering of water around the heme during solvation. The free energy required to break the iron(III)-ligand 5 (L5) bond is a minor but crucial portion of the activation free energy. Donor-acceptor protein interactions are not involved in the transfer. Fast heme release from inactive protein has also been observed. Apoprotein recombination with porphyrins and hemes suggest that this lack of activity is a result of Fe-L5 bond breaking.
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| 3. |
- Christakopoulos, Paul, et al.
(författare)
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Direct conversion of straw to ethanol by Fusarium oxysporum : Effect of cellulose crystallinity
- 1991
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Ingår i: Enzyme and microbial technology. - 0141-0229 .- 1879-0909. ; 13:3, s. 272-274
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Tidskriftsartikel (refereegranskat)abstract
- Wheat straw was successfully fermented to ethanol by Fusarium oxysporum F3 in a one-step process. Cellulose crystallinity was found to be a major factor in the bioconversion process. Ethanol yields increased linearly with decreasing crystallinity index. Approximately 80% of straw carbohydrates were converted directly to ethanol with a yield of 0.28 g ethanol/g−1 of straw when the crystallinity index was reduced to 23.6%.
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| 4. |
- Christakopoulos, Paul, et al.
(författare)
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Direct ethanol conversion of pretreated straw by Fusarium oxysporum
- 1991
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 35:3, s. 297-300
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Tidskriftsartikel (refereegranskat)abstract
- Factors affecting the direct conversion of alkali pretreated straw to ethanol by Fusarium oxysporum F3 were investigated and the alkali level used for pretreatment and the degree of delignification of straw were found to be the most important. A linear correlation between ethanol yield and both the degree of straw delignification and the alkali level was observed. At optimum delignified straw concentration (4% w/v), a maximum ethanol yield of 0·275 g ethanol g−1 of straw was obtained corresponding to 67·8% of the theoretical yield.
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| 5. |
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| 6. |
- Koullas, D.P., et al.
(författare)
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Effect of alkali delignification on wheat straw saccharification by fusarium oxysporum cellulases
- 1993
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Ingår i: Biomass and Bioenergy. - 0961-9534 .- 1873-2909. ; 4:1, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- The effect of alkaline delignification of wheat straw on the chemical composition and the subsequent enzymic hydrolysis of the pretreated straw are reported. Both hot (120°°C) and cold (20–36°°C) delignification were investigated, using either aqueous or organic alkaline solutions. The treated lignocellulosic materials were hydrolyzed by the cellulases of Fusarium oxysporum strain F3. Both delignification and saccharification yield showed linear relationships with the level of alkali used. Under the chosen experimental conditions 70–100% hydrolysis was achieved either by hot or cold delignification. Delignification to at least 50% appeared crucial for total polysaccharide conversion.
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| 7. |
- Kristensson, Gerhard, et al.
(författare)
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Time domain inversion techniques for electromagnetic scattering problems
- 1992
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Ingår i: Invariant imbedding and inverse problems. - 0898713056 ; , s. 1-29
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a review of and a comparison between two different methods to solve an inverse scattering problem in the time domain. The problem is that of propagation of transient electromagnetic waves in spatially inhomogeneous slabs of finite length. The permittivity and conductivity profiles are assumed to vary only with depth and the scattering problem is thus onedimensional. Several algorithms to solve the direct and inverse scattering problems for continuous and discontinuous permittivity profiles are suggested. Some of these algorithms have not been published before. The aim of this paper is to compare and review these methods. More specifically, the numerical performance of the invariant imbedding approach (layer-stripping)and the Green functions formulation (downward continuation)is compared. Some new results based upon time reversal techniques for a lossless slab are presented in an appendix.
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| 8. |
- Paul, Jan, et al.
(författare)
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Temperature dependence of CO ligation to LegHb and Mb: 0-80°C
- 1994
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 231:4-6, s. 547-550
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Tidskriftsartikel (refereegranskat)abstract
- The temperature dependence of the coordination of CO to two hemoproteins, myoglobin (Mb) and leghemoglobin (LegHb), has been studied by absorption spectroscopy. All spectral changes in the electronic and infrared ranges are fully reversible between 8 and 88°C and indicate a more linear orientation of the distal ligand with increasing temperature. The characteristic energy for the above spectral changes is around 200 cm-1 or identical to the Fe-Imidazole (Im) mode in hemoproteins. Our results are also compared with recent models for the dynamics of CO adsorbed at the surfaces of transition metals. Based on these surface models we suggest that our observed temperature dependences stem from thermal excitations of the Fe-Im vibration. This implies a so far undocumented mechanism by which the Fe-proximal bond influences the binding and energy dissipation at the active site of hemoproteins.
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