| 1. |
- Bedo, Daniel, et al.
(författare)
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Coupling of poly(lactic acid) with a polyurethane elastomer by reactive processing
- 2017
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Ingår i: European Polymer Journal. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0014-3057 .- 1873-1945. ; 97, s. 409-417
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Tidskriftsartikel (refereegranskat)abstract
- A segmented polyurethane elastomer (PU) was synthesized in poly(lactic acid) (PLA) melt by reactive processing. The isocyanate component was anticipated to react with the end-groups of PLA resulting in the formation of block-copolymers. The stoichiometry of the functional groups was optimized in the preliminary experiments. Two different processing methods were compared in the further experiments: conventional mixing of PU with PLA (PLA/PU), and reactive blending (PLA-b-PU). The comparison of the structure and properties of compatibilized reactive blends and conventional physical blends clearly shows the benefits of reactive processing. Coupling resulted in a finer dispersion of the particles in the matrix leading to better mechanical properties in the reactive blend. The successful synthesis of PEA-b-PU block copolymers was confirmed by NMR spectroscopy. The isocyanate component was found to react only with the hydroxyl end-groups of PLA, while the formation of amide and acylurea groups was not detected on the carboxyl end.
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| 2. |
- Bense, Laszlo, et al.
(författare)
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Right main bronchus perforation detected by 3D-image
- 2011
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Ingår i: BMJ Case Reports. - : BMJ. - 1757-790X.
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Tidskriftsartikel (refereegranskat)abstract
- A male metal worker, who has never smoked, contracted debilitating dyspnoea in 2003 which then deteriorated until 2007. Spirometry and chest x-rays provided no diagnosis. A 3D-image of the airways was reconstructed from a high-resolution CT (HRCT) in 2007, showing peribronchial air on the right side, mostly along the presegmental airways. After digital subtraction of the image of the peribronchial air, a hole on the cranial side of the right main bronchus was detected. The perforation could be identified at the re-examination of HRCTs in 2007 and 2009, but not in 2010 when it had possibly healed. The occupational exposure of the patient to evaporating chemicals might have contributed to the perforation and hampered its healing. A 3D HRCT reconstruction should be considered to detect bronchial anomalies, including wall-perforation, when unexplained dyspnoea or other chest symptoms call for extended investigation.
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| 3. |
- Esteve-Codina, Anna, et al.
(författare)
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Gender specific airway gene expression in COPD sub-phenotypes supports a role of mitochondria and of different types of leukocytes
- 2021
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is a destructive inflammatory disease and the genes expressed within the lung are crucial to its pathophysiology. We have determined the RNAseq transcriptome of bronchial brush cells from 312 stringently defined ex-smoker patients. Compared to healthy controls there were for males 40 differentially expressed genes (DEGs) and 73 DEGs for females with only 26 genes shared. The gene ontology (GO) term "response to bacterium" was shared, with several different DEGs contributing in males and females. Strongly upregulated genes TCN1 and CYP1B1 were unique to males and females, respectively. For male emphysema (E)-dominant and airway disease (A)-dominant COPD (defined by computed tomography) the term "response to stress" was found for both sub-phenotypes, but this included distinct up-regulated genes for the E-sub-phenotype (neutrophil-related CSF3R, CXCL1, MNDA) and for the A-sub-phenotype (macrophage-related KLF4, F3, CD36). In E-dominant disease, a cluster of mitochondria-encoded (MT) genes forms a signature, able to identify patients with emphysema features in a confirmation cohort. The MT-CO2 gene is upregulated transcriptionally in bronchial epithelial cells with the copy number essentially unchanged. Both MT-CO2 and the neutrophil chemoattractant CXCL1 are induced by reactive oxygen in bronchial epithelial cells. Of the female DEGs unique for E- and A-dominant COPD, 88% were detected in females only. In E-dominant disease we found a pronounced expression of mast cell-associated DEGs TPSB2, TPSAB1 and CPA3. The differential genes discovered in this study point towards involvement of different types of leukocytes in the E- and A-dominant COPD sub-phenotypes in males and females.
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| 4. |
- Horváth, Gábor, et al.
(författare)
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Experimental evidence that stripes do not cool zebras
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- There are as many as 18 theories for the possible functions of the stripes of zebras, one of which is to cool the animal. We performed field experiments and thermographic measurements to investigate whether thermoregulation might work for zebra-striped bodies. A zebra body was modelled by water-filled metal barrels covered with horse, cattle and zebra hides and with various black, white, grey and striped patterns. The barrels were installed in the open air for four months while their core temperature was measured continuously. Using thermography, the temperature distributions of the barrel surfaces were compared to those of living zebras. The sunlit zebra-striped barrels reproduced well the surface temperature characteristics of sunlit zebras. We found that there were no significant core temperature differences between the striped and grey barrels, even on many hot days, independent of the air temperature and wind speed. The average core temperature of the barrels increased as follows: White cattle, grey cattle, real zebra, artificial zebra, grey horse, black cattle. Consequently, we demonstrate that zebra-striped coats do not keep the body cooler than grey coats challenging the hypothesis of a thermoregulatory role of zebra stripes.
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| 5. |
- Hsiung, Shih-Yi, et al.
(författare)
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Structures of the xyloglucans in the monocotyledon family Araceae (aroids)
- 2023
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Ingår i: Planta. - : Springer Nature. - 0032-0935 .- 1432-2048. ; 257:2
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Tidskriftsartikel (refereegranskat)abstract
- The aquatic Araceae species Lemna minor was earlier shown to have xyloglucans with a different structure from the fucogalactoxyloglucans of other non-commelinid monocotyledons. We investigated 26 Araceae species (including L. minor), from five of the seven subfamilies. All seven aquatic species examined had xyloglucans that were unusual in having one or two of three features: < 77% XXXG core motif [L. minor (Lemnoideae) and Orontium aquaticum (Orontioideae)]; no fucosylation [L. minor (Lemnoideae), Cryptocoryne aponogetonifolia, and Lagenandra ovata (Aroideae, Rheophytes clade)]; and > 14% oligosaccharide units with S or D side chains [Spirodela polyrhiza and Landoltia punctata (Lemnoideae) and Pistia stratiotes (Aroideae, Dracunculus clade)]. Orontioideae and Lemnoideae are the two most basal subfamilies, with all species being aquatic, and Aroideae is the most derived. Two terrestrial species [Dieffenbachia seguine and Spathicarpa hastifolia (Aroideae, Zantedeschia clade)] also had xyloglucans without fucose indicating this feature was not unique to aquatic species.
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| 6. |
- Imre, Balazs, et al.
(författare)
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Organocatalytic esterification of corn starches towards enhanced thermal stability and moisture resistance
- 2020
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 22:15, s. 5017-5031
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Tidskriftsartikel (refereegranskat)abstract
- Most commercial starch esters are currently produced under harsh alkaline conditions. Triggered by environmental concerns, organocatalysis has recently emerged as a sustainable alternative offering mild reaction conditions, reduced waste formation and high selectivity. In this paper, the catalytic effect of several organic acids for the heterogeneous esterification of corn starch is compared, followed by a systematic analysis of tartaric acid-catalysed reactions on substrates with varying amylose/amylopectin ratios using a range of carboxylic acid and anhydride reagents of different chain lengths. Reaction conditions (temperature, time and catalyst concentration) were optimized and products were thoroughly characterized in terms of degree of substitution, chemical structure, morphology, moisture uptake and thermal stability. Organocatalysis proved to be competitive with conventional, alkaline methods. Our study also demonstrates that sustainability can further be improved by the direct recycling of the liquid phase. Notably, however, the tartaric acid catalyst participates in substitution reactions with starch. Despite recent claims to the opposite, reactivity of the carboxylic acid derivatives is primarily determined by carbon chain-length, while reagent type and therefore water content in the reaction mixture has a crucial effect on the final properties of the product. Our results highlight the importance of selecting appropriate synthesis methods and conditions as well as characterization techniques in order to create materials with the desired property profile according to the targeted application.
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| 7. |
- Imre, Balázs, et al.
(författare)
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Reactive Compatibilization of Plant Polysaccharidesand Biobased Polymers : Review on Current Strategies,Expectations and Reality
- 2018
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344.
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Tidskriftsartikel (refereegranskat)abstract
- Our society is amidst a technological revolution towards a sustainable economy, focused on the development of biobased products in virtually all sectors. In this context, plant polysaccharides, as the most abundant macromoleculespresent in biomass represent a fundamental renewable resource for the replacement of fossil-based polymeric materials in commodity and engineering applications. However, native polysaccharides have several disadvantages compared to their synthetic counterparts, including reduced thermal stability, moisture absorption and limited mechanical performance, which hinder their direct application in native form in advanced material systems. Thus, polysaccharides are generally used in a derivatized form and/or in combination with other biobased polymers, requiring the compatibilization of such blends and composites. In this review we critically explore the current status and the future outlook of reactive compatibilization strategies of the most common plant polysaccharides in blends with biobased polymers. The chemical processes for the modification and compatibilization of starch and lignocellulosic based materialsare discussed, together with the practical implementation of these reactive compatibilization strategies with special emphasis on reactive extrusion. The efficiency of these strategies is critically discussed in the context on the definition of blending and compatibilization from a polymer physics standpoint; this relies on the detailed evaluation of the chemical structure of the constituent plant polysaccharides and biobased polymers, the morphology of the heterogeneous polymeric blends, and their macroscopic behavior, in terms of rheological and mechanical properties.
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| 8. |
- Kano, Izabella Szakalne, et al.
(författare)
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Agglomeration, foreign firms and firm exit in regions under transition : the increasing importance of related variety in Hungary
- 2019
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Ingår i: European Planning Studies. - : Routledge. - 0965-4313 .- 1469-5944. ; 27:11, s. 2099-2122
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Tidskriftsartikel (refereegranskat)abstract
- Related variety of economic activities is widely recognized to induce regional development; however, it is not clear how this mechanism takes place in regions that go through major structural and institutional transformation. Furthermore, foreign direct investment (FDI) is typically a major source of structural change in these areas; and we still need a better understanding on how foreign-owned (foreign) firms affect the dynamics of domestic-owned (domestic) companies. For these reasons we analyse firm-level exit in Hungarian city regions between 1996 and 2011, over the late post-socialist transition in manufacturing industries, focusing on the difference between foreign and domestic firms. Introducing ownership into the related variety calculation, we estimate the probability of firm exit with the region-level related variety calculated separately for foreign and domestic firms. Our results suggest that related variety of foreign firms decreases the probability of domestic firm exit earlier during the economic transition compared to the related variety of domestic firms. This finding supports the idea that FDI plays a formative role in regions under transition, and shows that domestic firms benefit from being in agglomerations where foreign firms are technologically related to each other.
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| 9. |
- Li, Yanping, et al.
(författare)
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Brown Algae Carbohydrates : Structures, Pharmaceutical Properties, and Research Challenges
- 2021
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Ingår i: Marine Drugs. - : MDPI AG. - 1660-3397. ; 19
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Forskningsöversikt (refereegranskat)abstract
- Brown algae (Phaeophyceae) have been consumed by humans for hundreds of years. Current studies have shown that brown algae are rich sources of bioactive compounds with excellent nutritional value, and are considered functional foods with health benefits. Polysaccharides are the main constituents of brown algae; their diverse structures allow many unique physical and chemical properties that help to moderate a wide range of biological activities, including immunomodulation, antibacterial, antioxidant, prebiotic, antihypertensive, antidiabetic, antitumor, and anticoagulant activities. In this review, we focus on the major polysaccharide components in brown algae: the alginate, laminarin, and fucoidan. We explore how their structure leads to their health benefits, and their application prospects in functional foods and pharmaceuticals. Finally, we summarize the latest developments in applied research on brown algae polysaccharides.
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| 10. |
- Ziegler-Heitbrock, Loems, et al.
(författare)
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The EvA study : aims and strategy
- 2012
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 40:4, s. 823-829
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Tidskriftsartikel (refereegranskat)abstract
- The EvA study is a European Union-funded project under the Seventh Framework Programme (FP7), which aims at defining new markers for chronic obstructive pulmonary disease (COPD) and its subtypes. The acronym is derived from emphysema versus airway disease, indicating that the project targets these two main phenotypes of the disease. The EvA study is based on the concept that emphysema and airway disease are governed by different pathophysiological processes, are driven by different genes and have differential gene expression in the lung. To define these genes, patients and non-COPD controls are recruited for clinical examination, lung function analysis and computed tomography (CT) of the lung. CT scans are used to define the phenotypes based on lung density and airway wall thickness. This is followed by bronchoscopy in order to obtain samples from the airways and the alveoli. These tissue samples, along with blood samples, are then subjected to genome-wide expression and association analysis and markers linked to the phenotypes are identified. The population of the EvA study is different from other COPD study populations, since patients with current oral glucocorticoids, antibiotics and exacerbations or current smokers are excluded, such that the signals detected in the molecular analysis are due to the distinct inflammatory process of emphysema and airway disease in COPD.
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