| 1. |
- Backlund, Y., et al.
(författare)
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Micromachining of Silicon for Thermal and Position-Sensitive Nuclear-Detector Applications
- 1989
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 279:3, s. 555-559
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Tidskriftsartikel (refereegranskat)abstract
- As part of a programme aiming at the development of small nuclear radiation detectors, for example thermal detectors and position sensitive mosaic structures of surface barrier type, a technique for micromachining the detector bodies in silicon has been developed. The technique is based on an anisotropic etching property of a solution, mainly consisting of KOH. The etch rate is strongly orientation dependent with a speed in the 〈100〉 direction about 400 times faster than in the 〈111〉 direction. The major steps in the etching procedure are described and some examples of deep etching in Si are shown.
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| 2. |
- Björck, I., et al.
(författare)
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Formation of enzyme resistant starch during autoclaving of wheat starch : Studies in vitro and in vivo
- 1987
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Ingår i: Journal of Cereal Science. - 0733-5210. ; 6:2, s. 159-172
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Tidskriftsartikel (refereegranskat)abstract
- The formation of in vitro resistant starch (RS) during autoclaving and freeze-drying of wheat starch suspension was evaluated. A substantial amount of starch, up to 8% (dry weight basis), was rendered resistant to amylases during heat-treatment unless solubilised in KOH, whereas freeze-drying had only marginal effects. Heat-treated wheat starch was incorporated into test diets to provide different levels of RS (0–5 %). The digestibility of starch was measured in vivo through balance experiments in normal rats and in rats treated with Nebacitin to suppress hind-gut fermentation. RS remained essentially undigested also in vivo. However, like certain types of dietary fibre, RS was readily metabolised (80–92 %) by the hind-gut microflora. Starch analysed with an enzymic method, in vitro accessible starch (AS), seemed to correspond to starch digestible in vivo. The in vivo digestibility of AS was close to 100 % whether Nebacitin was present or not. Energy utilisation decreased significantly with increasing level of RS in the diet. The biological value of dietary protein increased with increasing intake of RS in normal rats whereas no effect was noted in animals treated with Nebacitin. We conclude that RS formed during heat-treatment should be regarded as an easily fermentable dietary fibre component.
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| 3. |
- Nyman, M, et al.
(författare)
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Bulk laxatives : their dietary fibre composition, degradation, and faecal bulking capacity in the rat
- 1985
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 20:7, s. 95-887
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Tidskriftsartikel (refereegranskat)abstract
- The intestinal dietary fibre degradation and faecal bulking capacity of various bulk laxatives were investigated by means of balance experiments on rats. Nitrogen, fat, and mineral excretion in faeces was also studied. The dietary fibre content of the various bulk laxatives was quite different (in g/kg dry matter): ACO fibre tablets (barley and citrus pulp), 451; Fiberform (wheat bran-based), 817; Inolaxol (sterkulia gum), 696; and Vi-Siblin (ispaghula husk), 533. The increase in faecal dry matter per 1 g dietary fibre was similar with ACO fibre tablets, Fiberform, and Vi-Siblin. Inolaxol gave a significantly (p less than 0.001) higher faecal dry-weight increment, mainly due to an increased mineral excretion. Of the dry-weight increment, 59-82% constituted undegraded dietary fibre. Thus, 68-97% of the fibre passed through the gastrointestinal tract without being degraded. All the bulk laxatives caused a similar increase in the faecal N content, whereas the increase in faecal lipids was most pronounced with Vi-Siblin. The water-holding capacity of faeces was more pronounced with Inolaxol and Vi-Siblin than with ACO fibre tablets and Fiberform.
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| 4. |
- Nyman, M, et al.
(författare)
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Dietary fibre fermentation in the rat intestinal tract : effect of adaptation period, protein and fibre levels, and particle size
- 1985
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Ingår i: British Journal of Nutrition. - 0007-1145. ; 54:3, s. 43-635
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Tidskriftsartikel (refereegranskat)abstract
- 1. The fermentative breakdown of one resistant type of dietary fibre (wheat bran) and one easily-fermented fibre (low-methoxyl pectin) was studied with respect to the length of the adaptation period and fibre level in the diet. The breakdown of the resistant fibre was also studied regarding the protein level in the diet and particle size of the fibre. 2. Prolongation of the adaptation period from 4 to 18 d decreased the faecal dry weight considerably. The excretion of dietary fibre however, was similar, whereas a decrease in faecal nitrogen excretion could be seen. 3. A level of dietary protein of less than 50 g/kg impaired the fermentation of wheat-bran fibre, whereas a level higher than 100 g protein/kg did not further increase the degree of fermentation of the fibre. 4. The particle size did not change the fermentability of the fibre, equal amounts of the main components of coarse and milled bran being excreted in faeces. 5. Two different levels of wheat-bran fibre (48 and 96 g/kg) in the diet did not influence the fibre breakdown. Similar results were obtained with two levels of fibre from low-methoxyl pectin (42 and 84 g/kg), but a tendency towards a decreased percentage of faecal excretion of uronic acids was seen at the lower level of low-methoxyl pectin.
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| 5. |
- Nyman, M, et al.
(författare)
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Fermentation of dietary fibre in the intestinal tract : comparison between man and rat
- 1986
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Ingår i: British Journal of Nutrition. - : Cambridge University Press (CUP). - 0007-1145 .- 1475-2662. ; 55:3, s. 96-487
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Tidskriftsartikel (refereegranskat)abstract
- 1. The breakdown and faecal bulking capacity of dietary fibre preparations from wheat bran, apple, cabbage, carrot, and guar gum were compared in man and rat. 2. The degradation of the fibre showed good correlation between man and rat (r 0.99, regression coefficient 0.86). Wheat bran was the least well-digested, 66 and 59% of the neutral sugars being excreted in faeces of man and rat respectively. The breakdown of the fibre in apple, cabbage, carrot and guar gum was more complete and 4-29% of the neutral sugars were recovered in faeces. 3. The main dietary fibre constituents in each preparation were degraded to a similar extent in man and rat. The main dietary fibre constituents of apple, carrot, cabbage and guar gum were almost completely degraded. Of the xylose in wheat bran 45% (man) and 48% (rat) were recovered in faeces. However, the percentage excretion of glucose and arabinose from bran was higher in man. 4. A faecal glucan other than cellulose was identified in human faeces after guar gum, and has been provisionally identified as starch. No such glucan occurred in rat faeces. 5. A good correlation between the faecal bulking capacity in man and rat was seen (r 0.97, regression coefficient 0.56). Wheat bran had the best bulking capacity, while that of apple, cabbage, carrot and guar gum was less pronounced. Faecal bulking was inversely related to the amount of fibre which was water-soluble in each preparation. 6. It is concluded that this rat experimental model is useful for the prediction of fermentative breakdown and bulking capacity of dietary fibre in man. However, more comparative studies are needed to evaluate animal experiments regarding other physiological effects of dietary fibre.
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| 6. |
- Nyman, M. G.L., et al.
(författare)
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Fermentation of oat fiber in the rat intestinal tract : A study of different cellular areas
- 1988
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165. ; 48:2, s. 274-278
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Tidskriftsartikel (refereegranskat)abstract
- Intestinal fermentation of dietary fiber from oat husk, bran, and white flour and a commercial oat bran was investigated through balance experiments in rats. Both solubility and monomeric composition of the fiber differed widely. Fiber from husk was only 0.5% soluble and nearly completely resistant to fermentation whereas fiber from bran (38% soluble) and white flour (24% soluble) was more fermentable (62% and 55% of the intake, respectively). Fiber from commercial bran (37% soluble) was most extensively fermented; only 19% of the fiber could be detected in feces. The fecal dry weight with the husk in the diet was significantly (p < 0.001) higher than that for the other preparations. Most of the fecal dry weight increment for husk (~95%) could be accounted for as fiber whereas only 45-65% of the increment was undegraded fiber for the other preparations. An additional 20-30% could be explained by protein and ~15% by fat with these preparations.
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| 7. |
- Nyman, M., et al.
(författare)
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Popping of whole-grain wheat : Effects on dietary fibre degradation in the rat intestinal tract
- 1987
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Ingår i: Journal of Cereal Science. - 0733-5210. ; 5:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- The fermentative breakdown of dietary fibre in raw and popped whole-grain wheat products was investigated by using rat balance dietary experiments. The faecal excretion of total dietary fibre was 74% with raw wheat, compared with 58% with the ‘severely’ popped product. The increased fermentability, could be partly related to an increased proportion of soluble fibre, but also to the formation of acid-insoluble material, which was easily degraded by the microbial flora. This material was formed during popping and, on analysis, appeared as Klason lignin. It consisted mainly of Maillard reaction products formed from protein. Thus, Maillard products may contribute to the apparent dietary fibre content in processed cereals.
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| 8. |
- Stroke, H. H., et al.
(författare)
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Bolometers as Particle Spectrometers
- 1986
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Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499. ; 33:1, s. 759-761
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Tidskriftsartikel (refereegranskat)
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