| 1. |
- Almer, Sven, 1953-, et al.
(author)
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Leukocyte scintigraphy compared to intraoperative small bowel enteroscopy and laparotomy findings in Crohn's disease
- 2007
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In: Inflammatory Bowel Diseases. - : Oxford University Press (OUP). - 1078-0998 .- 1536-4844. ; 13:2, s. 164-174
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Journal article (peer-reviewed)abstract
- Background: Leukocyte scintigraphy is a noninvasive investigation to assess inflammation. We evaluated the utility of labeled leukocytes to detect small bowel inflammation and disease complications in Crohn's disease and compared it to whole small bowel enteroscopy and laparotomy findings.Methods: Scintigraphy with technetium-99m exametazime-labeled leukocytes was prospectively performed in 48 patients with Crohn's disease a few days before laparotomy; 41 also had an intraoperative small bowel enteroscopy. The same procedures were performed in 8 control patients. Independent grading of scans was compared with the results of enteroscopy and with surgical, histopathologic, and clinical data.Results: In the 8 control patients leukocyte scan, endoscopy, and histopathology were all negative for the small bowel. In patients with Crohn's disease and small bowel inflammation seen at enteroscopy and/or laparotomy (n = 39) the scan was positive in 33. In 8 patients without macroscopic small bowel inflammation, the scan was positive for the small bowel in 3 patients; at histology, 2 of 3 had inflammation. When combining results for patients and controls, the sensitivity of leukocyte scan for macroscopically evident small bowel inflammation was 0.85, specificity 0.81, accuracy 0.84, positive predictive value 0.92, and negative predictive value 0.68. Scintigraphy detected inflammatory lesions not known before laparotomy in 16 of 47 (34%) Crohn's disease patients and showed uptake in 25 of 35 (71%) bowel strictures. It was diagnostic regarding 4 of 8 abscesses and 9 of 15 fistulas. In 6 patients (13%) lesions first demonstrated by leukocyte scintigraphy were treated during the surgery performed.Conclusions: Leukocyte scintigraphy reliably detects small bowel inflammation in Crohn's disease. It gives additional information on the presence of inflammatory lesions in a fraction of patients planned for surgery.
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| 2. |
- Andersson, Peter, et al.
(author)
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Low symptomatic load in Crohn's disease with surgery and medicine as complementary treatments
- 1998
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In: Scandinavian Journal of Gastroenterology. - : Informa Healthcare. - 0036-5521 .- 1502-7708. ; 33:4, s. 423-429
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Journal article (peer-reviewed)abstract
- Background: The treatment of Crohn's disease has changed owing to the recognition of its chronicity. Medical maintenance treatment and limited resections have evolved as major concepts of management, regarded as complementary, and both aim at reducing the symptoms.Methods: We investigated the symptomatic load in Crohn's disease as reflected in a cross-sectional study of the symptom index, physicians' assessment, and the patients' perception of health. A cohort of 212 patients from the primary catchment area and 125 referred patients were studied.Results: Of catchment area patients, 83% were receiving medication, and the annual rate of abdominal surgery was 5.7%. Corresponding figures for the referred patients were 82% and 10.3%. According to the symptom index, 87% of catchment area patients were in remission or had only mild symptoms; according to the physicians' assessment, 90% were. The patients' median perception of health was 90% of perfect health according to the visual analogue scale. The figures were similar for referred patients, except that referrals were considered more diseased by the physician.Conclusion: The great majority of patients with Crohn's disease are able to live in remission or experience only mild symptoms.
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| 3. |
- Börjesson, Mikaela, 1987, et al.
(author)
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Periodate oxidation of xylan-based hemicelluloses and its effect on their thermal properties
- 2018
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In: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 202, s. 280-287
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Journal article (peer-reviewed)abstract
- Hemicellulose from pulp mill process water and crop residuals from food production often end up in waste streams or burnt for energy contribution. These waste products contain valuable biopolymers but lack many attributes needed for use in applications such as food and medical or consumer products. This study reports on an investigation of the periodate oxidation of hardwood xylan and arabinoxylan (AX) from wheat bran to produce materials with new functionalities. The study explores how to control the oxidation degree and describes structural differences between the two xylan-based polymers. For the xylan samples, the oxidation resulted in a lowering of the glass transition temperature (Tg), indicating a more flexible chain due to ring-opening of the xylan anhydro-sugar units. For the AX samples, the arabinose side-groups were instead oxidized, hindering oxidation on part of the xylose units, which resulted in a crosslinked network with an unchanged Tgbut reduced intrinsic viscosity.
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| 4. |
- Börjesson, Mikaela, 1987, et al.
(author)
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Thermoplastic and flexible films from arabinoxylan
- 2019
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In: ACS Applied Polymer Materials. - : American Chemical Society (ACS). - 2637-6105. ; 1:6, s. 1443-1450
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Journal article (peer-reviewed)abstract
- Current interest in replacing fossil-fuel-derivedpolymers and materials in favor of renewable materials is high.An inherent difficulty with the use of biomass-derivedpolysaccharides and hemicelluloses in this context, however,is their stiffness and lack offlowability at temperatures relevantfor thermal processing, which severely limits their capacity forthermal processing. Here, we present a modification thatenables a heat-processable arabinoxylan (AX). The modifica-tion involves a ring-opening oxidation to a dialdehyde withsubsequent reduction of the aldehydes to alcohol, to increasethe number of OH groups, followed by an etherification withhydrophobic alkyl chains. The modified AX was successfullycompression molded with heat intofilmswhich becomethermoplastic in behavior and highlyflexibleandflows at temperatures above 130°C. Thefilms are stretchable up to 200%,and their strength and strain deformation are controlled by the degree of oxidation and substitution of the AX polymer. Thesefindings are highly encouraging and open up the potential use of modified AX alone or as a composite in applications thatincludefilms, food packaging, and barriers via hot-melt processing techniques.
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| 5. |
- Deralia, Parveen Kumar, 1985, et al.
(author)
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Hydrophobization of arabinoxylan with n-butyl glycidyl ether yields stretchable thermoplastic materials
- 2021
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 188, s. 491-500
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Journal article (peer-reviewed)abstract
- Hemicelluloses are regarded as one of the first candidates for the development of value-added materials due to their renewability, abundance, and functionality. However, because most hemicelluloses are brittle, they can only be processed as a solution and cannot be processed using industrial melt-based polymer processing techniques. In this study, arabinoxylan (AX) was hydrophobized by incorporating butyl glycidyl ether (BuGE) into the hydroxyl groups through the opening of the BuGE epoxide ring, yielding alkoxy alcohols with terminal ethers. The formed BuGE derivatives were melt processable and can be manufactured into stretchable thermoplastic films through compression molding, which has never been done before with hemicellulose modified in a single step. The structural and thermomechanical properties of the one-step synthesis approach were compared to those of a two-step synthesis with a pre-activation step to demonstrate its robustness. The strain at break for the one-step synthesized AX thermoplastic with 3 mol of BuGE is ≈200%. These findings suggest that thermoplastic polymers can be composited with hemicelluloses or that thermoplastic polymers made entirely of hemicelluloses can be designed as packaging and stretchable electronics supports.
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| 6. |
- Deralia, Parveen Kumar, 1985, et al.
(author)
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Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics
- 2021
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In: ACS Applied Bio Materials. - : American Chemical Society (ACS). - 2576-6422. ; 4:4, s. 3133-3144
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Journal article (peer-reviewed)abstract
- Developing flexible, stretchable, and thermally processable materials for packaging and stretchable electronic applications from polysaccharide-based polymers contributes to the smooth transition of the fossil-based economy to the circular bioeconomy. We present arabinoxylan (AX)-based thermoplastics obtained by ring-opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE), and 2-ethyl hexyl (EtHGE) glycidyl ether]. We also investigate the relationship between structural composition, thermal processing, and thermomechanical properties. BuGE- A nd iPrGE-etherified dA-AXs showed glass-transition temperatures (Tg) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140 °C. The BuGE (3 mol)-etherified dA-AX films at 19 and 31% oxidation levels show 244% (±42) and 267% (±72) elongation, respectively. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had a maximum of 60% (±19) elongation. No studies have reported such superior elongation of AX thermoplastic films and its relationship with molar substitution and Tg. These findings have implications on the strategic development of chemical modification routes using commercial polymer processing technologies and on fine-tuning structures and properties when specific polysaccharide-based polymers are used to engineer bio-based products for film, packaging, and substrates for stretchable electronic applications.
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| 7. |
- Deralia, Parveen Kumar, 1985, et al.
(author)
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Side chains affect the melt processing and stretchability of arabinoxylan biomass-based thermoplastic films
- 2022
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In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 294
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Journal article (peer-reviewed)abstract
- Hydrophobization of hemicellulose causes melt processing and makes them stretchable thermoplastics. Understanding how native and/or appended side chains in various hemicelluloses after chemical modification affect melt processing and material properties can help in the development of products for film packaging and substrates for stretchable electronics applications. Herein, we describe a one-step and two-step strategy for the fabrication of flexible and stretchable thermoplastics prepared by compression molding of two structurally different arabinoxylans (AX). For one-step synthesis, the n-butyl glycidyl ether epoxide ring was opened to the hydroxyl group, resulting in the introduction of alkoxide side chains. The first step in the two-step synthesis was periodate oxidation. Because the melt processability for AXs having low arabinose to xylose ratio (araf/xylp<0.5) have been limited, two structurally distinct AXs extracted from wheat bran (AXWB, araf/xylp = 3/4) and barley husk (AXBH, araf/xylp = 1/4) were used to investigate the effect of araf/xylp and hydrophobization on the melt processability and properties of the final material. Melt compression processability was achieved in AXBH derived samples. DSC and DMA confirmed that the thermoplastics derived from AXWB and AXBH had dual and single glass transition (Tg) characteristics, respectively, but the thermoplastics derived from AXBH had lower stretchability (maximum 160%) compared to the AXWB samples (maximum 300%). Higher araf/xylp values, and thus longer alkoxide side chains in AXWB-derived thermoplastics, explain the stretchability differences.
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| 8. |
- Eriksson, Daniel, et al.
(author)
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GWAS for autoimmune Addison’s disease identifies multiple risk loci and highlights AIRE in disease susceptibility
- 2021
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In: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 12:1
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Journal article (peer-reviewed)abstract
- Autoimmune Addison's disease (AAD) is characterized by the autoimmune destruction of the adrenal cortex. Low prevalence and complex inheritance have long hindered successful genetic studies. We here report the first genome-wide association study on AAD, which identifies nine independent risk loci (P < 5 × 10-8). In addition to loci implicated in lymphocyte function and development shared with other autoimmune diseases such as HLA, BACH2, PTPN22 and CTLA4, we associate two protein-coding alterations in Autoimmune Regulator (AIRE) with AAD. The strongest, p.R471C (rs74203920, OR = 3.4 (2.7-4.3), P = 9.0 × 10-25) introduces an additional cysteine residue in the zinc-finger motif of the second PHD domain of the AIRE protein. This unbiased elucidation of the genetic contribution to development of AAD points to the importance of central immunological tolerance, and explains 35-41% of heritability (h2).
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| 9. |
- Esmaily, Mohsen, 1987, et al.
(author)
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Corrosion behavior of alloy AM50 in semi-solid cast and high pressure die cast states in cyclic conditions
- 2015
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In: Corrosion. - : Association for Materials Protection and Performance (AMPP). - 0010-9312 .- 1938-159X. ; 71:6, s. 737-748
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Journal article (peer-reviewed)abstract
- The atmospheric corrosion behavior of the Mg-Al alloy AM50 produced by high pressure die casting (HPDC) and a semi-solid metal (SSM) technique was studied under alternating wet-dry conditions for up to 672 hours. The alloy AM50 in the SSC state was fabricated using rheocasting (RC) technique in which the slurry was prepared by the newly developed RheoMetal process. To simulate the real-world atmospheric environment, the exposure program included a 6 hour wet phase (including rain with 0.5 % NaCl), a 2.5 hours transition phase followed by a 15.5 hours dry phase at 50°C and 70% relative humidity (RH). The results showed that the RC alloy was substantially less prone to corrosion than the HPDC material in the cyclic wet/dry atmosphere. Based on the gravimetric results and microstructural characterization studies, this was attributed to a lower fraction of porosity and to the barrier role of β phase particles in the RC.
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| 10. |
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