| 51. |
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| 52. |
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| 53. |
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| 54. |
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| 55. |
- Kotov, P. V., et al.
(författare)
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Recovery of the ponderomotive parametric instability after long pumping of the ionosphere
- 2007
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 40:3
-
Tidskriftsartikel (refereegranskat)abstract
- We show that during high frequency (HF) pumping of the overhead ionosphere with a pump wave frequency slightly above the local fifth electron gyroharmonic, when one switches the pump wave from continuous pumping to low duty cycle pulse pumping, the stimulated electromagnetic emission (SEE) features related to the ponderomotive parametric instability (PPI) near the pump wave reflection point, such as the ponderomotive narrow continuum and the narrow continuum maximum, recover and become dominating in the SEE spectra after a few seconds after the switch. Simultaneously, the ionospherically reflected pump wave signal exhibits a recovery of ponderomotive self-action and the damped quasi-periodical oscillations (spikes) of the reflected pump wave, also related to the PPI development. The intensity of the down-shifted maximum (DM) feature in the SEE spectra increases for about 1–2 s after the switch to the pulse mode, but later, together with PPI related phenomena recovery, the DM intensity decreases noticeably. The phenomena described are attributed to the relaxation of small-scale irregularities (striations). The latter provide strong scattering of the pump wave into upper hybrid waves, strong shielding of the pump wave reflection point, and generation of the upper-hybrid related DM feature.
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| 56. |
- Kovacev, M, et al.
(författare)
-
Extreme ultraviolet fourier-transform spectroscopy with high order harmonics
- 2005
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Ingår i: Physical Review Letters. - 1079-7114. ; 95:22
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a new scheme for extreme ultraviolet (xuv) Fourier-transform spectroscopy based on the generation of two phase-locked high-harmonic beams. It allows us to measure for the first time interferograms at wavelengths as short as 90 nm, and open the perspective of performing high-resolution Fourier-transform absorption spectroscopy in the xuv. Our measurements also demonstrate that a precise control of the relative phase of harmonic pulses can be obtained with an accuracy on an attosecond time scale, of importance for future xuv pump-xuv probe attosecond spectroscopy.
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| 57. |
- Li, Z. S, et al.
(författare)
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Radiative properties of neutral germanium obtained from excited-state lifetime and branching-ratio measurements and comparison with theoretical calculations
- 1999
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 60:1, s. 198-208
-
Tidskriftsartikel (refereegranskat)abstract
- Using time-resolved UV laser-induced fluorescence from a laser-produced plasma, natural radiative lifetimes have been measured for 21 levels of Ge I belonging to the odd-parity 4p4d, 4p5d, and 4p6s configurations. Stimulated Brillouin scattering in water has allowed us to compress Nd:YAG laser pulses pumping a dye laser (where YAG denotes yttrium aluminum garnet), thus yielding 1-ns tunable laser pulses to enable accurate measurements of short lifetimes. Branching ratios of Ge I have been measured by inductively coupled plasma emission spectrometry, the intensity calibration being performed by means of Ar lines emitted by a hollow-cathode lamp. The experimental lifetimes and branching ratios have been combined in order to provide a set of accurate transition probabilities for the 4p-5s and 4p-4d transitions. A relativistic Hartree-Fock; calculation, taking configuration-interaction and polarization effects into account, has been combined with a least-squares optimization procedure of the Slater and spin-orbit integrals in order to test the ability of this approach to correctly predict radiative properties of the group-IV elements. Good agreement between experimental and theoretical transition probability values has been achieved for most of the transitions considered.
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| 58. |
- Lundström, Erik, 1964-, et al.
(författare)
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Effects of Fluoxetine on Outcomes at 12 Months After Acute Stroke Results From EFFECTS, a Randomized Controlled Trial
- 2021
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 52:10, s. 3082-3087
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The EFFECTS (Efficacy of Fluoxetine-a Randomised Controlled Trial in Stroke) recently reported that 20 mg fluoxetine once daily for 6 months after acute stroke did not improve functional outcome but reduced depression and increased fractures and hyponatremia at 6 months. The purpose of this predefined secondary analysis was to identify if any effects of fluoxetine were maintained or delayed over 12 months. METHODS: EFFECTS was an investigator-led, randomized, placebo-controlled, double-blind, parallel group trial in Sweden that enrolled adult patients with stroke. Patients were randomized to 20 mg oral fluoxetine or matching placebo for 6 months and followed for another 6 months. The primary outcome was functional outcome (modified Rankin Scale), at 6 months. Predefined secondary outcomes for these analyses included the modified Rankin Scale, health status, quality of life, fatigue, mood, and depression at 12 months. RESULTS: One thousand five hundred patients were recruited from 35 centers in Sweden between 2014 and 2019; 750 were allocated fluoxetine and 750 placebo. At 12 months, modified Rankin Scale data were available in 715 (95%) patients allocated fluoxetine and 712 (95%) placebo. The distribution of modified Rankin Scale categories was similar in the 2 groups (adjusted common odds ratio, 0.92 [95% CI, 0.76-1.10]). Patients allocated fluoxetine scored worse on memory with a median value of 89 (interquartile range, 75-100) versus 93 (interquartile range, 82-100); P=0.0021 and communication 93 (interquartile range, 82-100) versus 96 (interquartile range, 86-100); P=0.024 domains of the Stroke Impact Scale compared with placebo. There were no other differences in secondary outcomes. CONCLUSIONS: Fluoxetine after acute stroke had no effect on functional outcome at 12 months. Patients allocated fluoxetine scored worse on memory and communication on the Stroke Impact Scale compared with placebo, but this is likely to be due to chance.
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| 59. |
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| 60. |
- Midtvedt, T, et al.
(författare)
-
Response to Surawicz et al
- 2013
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Ingår i: The American journal of gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 1572-0241 .- 0002-9270. ; 108:12, s. 1931-1932
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 61. |
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| 62. |
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| 63. |
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| 64. |
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| 65. |
- Mårtensson, Olof, et al.
(författare)
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Effects of fermented, ropy, non-dairy, oat-based products on serum lipids and the faecal excretion of cholesterol and short chain fatty acids in germfree and conventional rats
- 2002
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Ingår i: Nutrition Research. - 0271-5317. ; 22:12, s. 1461-1473
-
Tidskriftsartikel (refereegranskat)abstract
- Three fermented, ropy, non-dairy, oat-based products were evaluated for their effect on serum lipids, faecal cholesterol and faecal short chain fatty. acids in germfree and conventional rats. Three different exopolysaccharide (EPS) producing lactic acid bacteria strains were used to ferment the non-dairy oat-base (Adavena(R) G40) (Ceba Foods AB, Lund; Sweden). Two commercial non-dairy products based on oats (Mill Milk(TM)) (Ceba Foods AB, Lund, Sweden) and rice (Rice Dream(R)) (Imagine Foods, London, UK) were used as non-ropy and unfermented controls. All the standardized feeds were sterilized before being fed to the animals. Adult, germfree-and conventional AGUS rats, were fed the above sterile diets ad libitum for 21 days. Blood samples and faecal samples were collected and the animals' weight gain was monitored throughout the study. No significant change in serum lipids or faecal excretion of cholesterol was observed between the groups on the different diets. A difference in faecal SCFA pattern was observed in conventional rats fed on the oat-based diets in comparison. to the group fed on the rice-based diet. More evidence is needed to support the effect of fermented, ropy, oat-based products and their potential effect on serum lipids, faecal cholesterol/coprostanol levels and amounts of short chain fatty acids.
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| 66. |
- Mårtensson, Olof, et al.
(författare)
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Fermented, ropy, oat-based products reduce cholesterol levels and stimulate the bifidobacteria flora in humans
- 2005
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Ingår i: Nutrition Research. - : Elsevier BV. - 0271-5317. ; 25:5, s. 429-442
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Tidskriftsartikel (refereegranskat)abstract
- This investigation determined the effects of fermented oat-based products containing both native and microbial beta-glucans on plasma lipids and on fecal total bacterial count and Bifidobacterium ssp. The study was randomized, double blind with 3 parallel groups. Sixty-two free-living volunteers with moderately increased plasma cholesterol levels were recruited. In the final analysis, 56 subjects remained, as 6 subjects had left the study either due to lack of time (n = 2), unwillingness to continue the regimen (n = 2), or for other reasons (n = 2). During the first 3 weeks, all subjects received a fermented dairy-based product (control product, run-in period). On the following 5 weeks, I group continued with the control product, whereas the other 2 groups were given fermented oat-based products (intervention period, 3-3.5 g native beta-glucans per day). One of the oat products (ropy) was cofermented with an exopolysaccharide-producing strain, Pediococcus damnosus 2.6. A significant (P = .022) reduction in total cholesterol by 6% was observed in volunteers who had eaten the fermented, ropy, oat-based product compared with the control group. No other significant changes in plasma lipids were found. A significant increase in total bacterial count (P = .001) and Bifidobacterium ssp (P = .012) was observed in fecal samples from volunteers in the group who had eaten the fermented, ropy, oat-based product. This study shows that a fermented, ropy, oat-based product, containing both native and microbial glucans, can reduce the blood cholesterol level and also stimulate the bifidobacteria flora in the gastrointestinal tract. (c) 2005 Elsevier Inc. All rights reserved.
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| 67. |
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| 68. |
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| 69. |
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| 70. |
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| 71. |
- Norin, E
(författare)
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Intestinal cholesterol conversion in adults and elderly from four different European countries
- 2008
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Ingår i: Annals of nutrition & metabolism. - : S. Karger AG. - 1421-9697 .- 0250-6807. ; 5252 Suppl 1, s. 12-14
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Tidskriftsartikel (refereegranskat)abstract
- The growing healthy aging population in Europe is a heterogeneous group with varying nutritional needs, especially in association with problems like decreased sense of smell and taste, saliva production, chewing and swallowing problems besides all disease problems that put specific demands on the dietary intake and the role of the intestinal metabolism. To investigate this, one must clarify which functions are related to the host itself and which actions are related to the microflora. In short, the host’s side of the ecosystem can be defined as <X_Underline>m</X_Underline>ilieu <X_Underline>i</X_Underline>nterieur (MI), the non-host side as <X_Underline>m</X_Underline>ilieu <X_Underline>e</X_Underline>xterieur (ME) and MI plus ME together as <X_Underline>m</X_Underline>ilieu <X_Underline>t</X_Underline>otal (MT). We have investigated the role of the intestinal flora and its functions in adults and elderly from different European countries and this publication is concentrated on the microbial conversion of intestinal cholesterol to coprostanol, aiming to investigate the hepatic-intestinal flora co-cross-talk.
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| 72. |
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| 73. |
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| 74. |
- Norin, Lars, et al.
(författare)
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Ionospheric plasma density irregularities measured by stimulated electromagnetic emission
- 2008
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 113:A9, s. A09314-
-
Tidskriftsartikel (refereegranskat)abstract
- It is well known that ionospheric plasma turbulence can be conveniently generated by controlled injection of powerful high-frequency radio beams from the ground. Irradiation of the ionosphere with such radio waves leads to the formation of plasma density structures, striations, and the generation of secondary electromagnetic radiation, a phenomenon known as stimulated electromagnetic emission (SEE). In this paper we present experimental results of the dependence of SEE on decreasing excitation levels of the striations. In the experiments the frequency of the injected radio beam was varied near the fifth harmonic of the local ionospheric electron gyro frequency. We use the SEE measurements to obtain transverse length scales of the striations involved in the generation of the SEE. Our results show that different spectral features of the SEE display different temporal dynamics, suggesting that they are related to striations with different transverse length scales (1 less than or similar to L-perpendicular to less than or similar to 25 m).
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| 75. |
- Norin, Lars, et al.
(författare)
-
Transient dynamics of secondary radiation from an HF pumped magnetized space plasma
- 2007
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 119:A9
-
Tidskriftsartikel (refereegranskat)abstract
- In order to systematically analyze the transient wave and radiation processes that are excited when a high-frequency (HF) radio wave is injected into a magnetized space plasma, we have measured the secondary radiation, or stimulated electromagnetic emission (SEE), from the ionosphere, preconditioned such that geomagnetic field-aligned plasma irregularities are already present. The transient dynamics experiments were made using a duty cycle of the HF radio wave of 200 ms (180 ms on and 20 ms off) and 100 ms (80 ms on and 20 ms off) for various frequencies near the fifth harmonic of the local ionospheric electron cyclotron frequency. Within the first 10 ms after the radio pulse turn-on, frequency downshifted structures of the SEE exhibit an overshoot with a maximum at 3 ms < t < 8 ms, whereas the upshifted spectral components do not exhibit this feature. The relative magnitude of the overshoot is strongly dependent on the frequency offset of the pump from the harmonic of the electron cyclotron frequency. A transient blue-shifted frequency component is identified. This component is upshifted from the pump by 14 kHz < Δ f< 55 kHz and exists only within the first 10 ms after the radio pulse turn-on. On a longer time scale we analyze the amplitude modulation, or "ringing," of the reflected radio wave, (also known as "quasi-periodic oscillations" or "spikes"). The ringing has a frequency of the order 15-20 Hz and we show that this phenomenon is also present in the SEE sidebands and is synchronized with the ringing of the reflected HF wave itself.
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| 76. |
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| 77. |
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| 78. |
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| 79. |
- Rosen, Lars, 1962, et al.
(författare)
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SCORE: A novel multi-criteria decision analysis approach to assessing the sustainability of contaminated land remediation
- 2015
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 511, s. 621-638
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Tidskriftsartikel (refereegranskat)abstract
- The multi-criteria decision analysis (MCDA) method provides for a comprehensive and transparent basis for performing sustainability assessments. Development of a relevant MCDA-method requires consideration of a number of key issues, e.g. (a) definition of assessment boundaries, (b) definition of performance scales, both temporal and spatial, (c) selection of relevant criteria (indicators) that facilitate a comprehensive sustainability assessment while avoiding double-counting of effects, and (d) handling of uncertainties. Adding to the complexity is the typically wide variety of inputs, including quantifications based on existing data, expert judgements, and opinions expressed in interviews. The SCORE (Sustainable Choice Of REmediation) MCDA-method was developed to provide a transparent assessment of the sustainability of possible remediation alternatives for contaminated sites relative to a reference alternative, considering key criteria in the economic, environmental, and social sustainability domains. The criteria were identified based on literature studies, interviews and focus-group meetings. SCORE combines a linear additive model to rank the alternatives with a non-compensatory approach to identify alternatives regarded as non-sustainable. The key strengths of the SCORE method are as follows: a framework that at its core is designed to be flexible and transparent; the possibility to integrate both quantitative and qualitative estimations on criteria; its ability, unlike other sustainability assessment tools used in industry and academia, to allow for the alteration of boundary conditions where necessary; the inclusion of a full uncertainty analysis of the results, using Monte Carlo simulation; and a structure that allows preferences and opinions of involved stakeholders to be openly integrated into the analysis. A major insight from practical application of SCORE is that its most important contribution may be that it initiates a process where criteria otherwise likely ignored are addressed and openly discussed between stakeholders.
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| 80. |
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| 81. |
- Santangelo, E. M., et al.
(författare)
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Resolution of an iridoid synthon, gastrolactol, by means of dynamic acetylation and lipase-catalyzed alcoholysis
- 2001
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 66:16, s. 5384-5387
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Tidskriftsartikel (refereegranskat)abstract
- A short synthetic route to asymmetric iridoids was developed. The three key steps were an intramolecular [4 + 2] cycloaddition reaction of an enamine derivative of 8-oxocitral (2), a dynamic acetylation, and an enzymatic resolution of the gastrolactyl acetates 5a and 5b, iridoids with three stereocenters. Some regio- and stereoselective heterogeneous catalytic hydrogenations of double bonds in iridoid aglucones were discussed.
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| 82. |
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| 83. |
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| 84. |
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| 85. |
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| 86. |
- Sobko, T, et al.
(författare)
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Gastrointestinal nitric oxide generation in germ-free and conventional rats
- 2004
-
Ingår i: American journal of physiology. Gastrointestinal and liver physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 287:5, s. G993-G997
-
Tidskriftsartikel (refereegranskat)abstract
- Nitric oxide (NO) is a central mediator of various physiological events in the gastrointestinal tract. The influence of the intestinal microflora for NO production in the gut is unknown. Bacteria could contribute to this production either by stimulating the mucosa to produce NO, or they could generate NO themselves. Using germ-free and conventional rats, we measured gaseous NO directly in the gastrointestinal tract and from the luminal contents using a chemiluminescence technique. Mucosal NO production was studied by using an NO synthase (NOS) inhibitor, and to evaluate microbial contribution to the NO generation, nitrate was given to the animals. In conventional rats, luminal NO differed profoundly along the gastrointestinal tract with the greatest concentrations in the stomach [>4,000 parts per billion (ppb)] and cecum (≈200 ppb) and lower concentrations in the small intestine and colon (≤20 ppb). Cecal NO correlated with the levels in incubated luminal contents. NOS inhibition lowered NO levels in the colon, without affecting NO in the stomach and in the cecum. Gastric NO increased greatly after a nitrate load, proving it to be a substrate for NO generation. In germ-free rats, NO was low (≤30 ppb) throughout the gastrointestinal tract and absent in the incubated luminal contents. NO also remained low after a nitrate load. Our results demonstrate a pivotal role of the intestinal microflora in gastrointestinal NO generation. Distinctly compartmentalized qualitative and quantitative NO levels in conventional and germ-free rats reflect complex host microbial cross talks, possibly making NO a regulator of the intestinal eco system.
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| 87. |
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| 88. |
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| 89. |
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| 90. |
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| 91. |
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| 92. |
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| 93. |
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| 94. |
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| 95. |
- Szponar, Bogumila, et al.
(författare)
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Limitations in the use of 3-hydroxy fatty acid analysis to determine endotoxin in mammalian samples
- 2002
-
Ingår i: Journal of Microbiological Methods. - 1872-8359 .- 0167-7012. ; 50:3, s. 283-289
-
Tidskriftsartikel (refereegranskat)abstract
- 3-Hydroxy fatty acids (3-OH FAs) of 10-18-carbon chain lengths are constituents of the lipopolysaccharide of Gram-negative bacteria. These acids are used as chemical markers for determining endotoxin in environmental samples. The present communication addresses the question whether this type of analysis also would be applicable to mammalian samples. Low levels (6.1 +/- 1.6-94.0 +/- 23.2 pmol/ml) of the studied 3-OH FAs were detected in blood from both conventional and germ-fine rats. The levels were considerably higher (0.0-1.06 +/- 0.17 nmol/mg) in livers. The amounts of the 3-OH FAs did not differ between the two groups of rats. All analyses were made by gas chromatography-tandem mass spectrometry (GC-MSMS) for unequivocal identification. The results illustrate a limitation in using 3-OH FA analysis to determine endotoxin in mammalian samples since these acids may represent not only endotoxin but also products from mammalian mitochondrial fatty acid beta-oxidation. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 96. |
- Tjellstrom, B, et al.
(författare)
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A Role for Bacteria in Celiac Disease?
- 2016
-
Ingår i: Digestive diseases and sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 61:7, s. 2140-2140
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 97. |
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| 98. |
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| 99. |
- Tjellstrom, B., et al.
(författare)
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The effects of oats on the function of gut microflora in children with coeliac disease
- 2014
-
Ingår i: Alimentary Pharmacology and Therapeutics. - : Wiley. - 0269-2813 .- 1365-2036. ; 39:10, s. 1156-1160
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Tidskriftsartikel (refereegranskat)abstract
- Background Faecal short chain fatty acids (SCFAs) are produced by the gut microflora. We have previously reported high faecal SCFA levels in children with coeliac disease (CD), indicating alteration in gut microfloral metabolism. Data accumulated over recent decades by us and others suggest that wheat-free oats can safely be included in a gluten-free diet (GFD). However, concerns have been raised with respect to the safety of oats in a subset of coeliacs. Aim To describe faecal SCFA patterns in children with newly diagnosed CD treated for 1year with a GFD with or without oats. Methods This report is part of a randomised, double-blind study on the effect of a GFD containing oats (GFD-oats) vs. a standard GFD (GFD-std). Faecal samples were received from 34 children in the GFD-oats group and 37 in the GFD-std group at initial diagnosis and/or after 1year on a GFD. Faecal SCFAs were analysed. Results The GFD-std group had a significantly lower total faecal SCFA concentration at 12months compared with 0months (Pless than0.05). In contrast, total SCFA in the GFD-oats group remained high after 1year on the GFD. The children in the GFD-oats group had significantly higher acetic acid (Pless than0.05), n-butyric acid (Pless than0.05) and total SCFA concentration (Pless than0.01) after 1-year diet treatment compared to the GFD-std group. Conclusions Our results indicate that oats do affect the gut microflora function, and that some coeliac children receiving oats may develop gut mucosal inflammation, that may present a risk for future complications.
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| 100. |
- Tjellström, Bo, et al.
(författare)
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Gut microflora associated characteristics in children with celiac disease
- 2005
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Ingår i: American Journal of Gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 0002-9270 .- 1572-0241. ; 100:12, s. 2784-2788
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The aim of the study was to investigate the metabolic function of intestinal microflora in children with celiac disease (CD) in order to find out if there is a deviant gut flora in CD patients compared to healthy controls. METHODS: The study group comprised children with CD, consecutively diagnosed according to current criteria given by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition. Thirty-six children were studied at presentation, i.e., on a normal gluten-containing diet, with clinical symptoms and signs indicative of CD, positive celiac serology markers, and a small bowel biopsy showing severe enteropathy. Forty-seven patients were studied when they had been on a gluten-free diet (GFD) for at least 3 months. For comparison, a group of 42 healthy controls (HC) were studied. The functional status of the intestinal microflora was evaluated by gas-liquid chromatography of short chain fatty acids (SCFAs) in fecal samples. RESULTS: There was a significant difference between untreated CD children and HC as well as between treated CD children and HC regarding acetic, i-butyric, i-valeric acid, and total SCFAs. The propionic and n-valeric acids differed significantly between CD children on GFD and HC. Moreover, there was a strong correlation between i-butyric and i-valeric acids in all study groups. CONCLUSIONS: This is the first study of the SCFA pattern in fecal samples from children with CD. The results indicate that there is a difference in the metabolic activity of intestinal microbial flora in children with CD compared to that in HC. The finding of a different pattern of some SCFAs in celiacs both at presentation and during treatment with GFD indicates that it is a genuine phenomenon of CD not affected by either the diet, the inflammation, or the autoimmune status of the patient. © 2005 by Am. Coll. of Gastroenterology Published by Blackwell Publishing.
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