Asymmetric Monomer, Amorphous Polymer? Structure-Property Relationships in 2,4-FDCA and 2,4-PEF
Nolasco, Mariela M. ; Araujo, Catarina F. ; Thiyagarajan, Shanmugam ; Rudić, Svemir ; Vaz, Pedro D. ; Silvestre, Armando J.D. ; Ribeiro-Claro, Paulo J.A. ; Sousa, Andreia F. - \ 2020
Macromolecules 53 (2020)4. - ISSN 0024-9297 - p. 1380 - 1387.
The biobased polyester poly(ethylene 2,4-furanoate) (2,4-PEF) is a potentially interesting yet insufficiently studied polymer whose resistance to crystallization fundamentally stems from the asymmetric nature of the 2,4-furandicarboxylic acid monomer. A combination of vibrational spectroscopy (infrared, Raman and inelastic neutron scattering) and ab initio calculations has been used to assess the conformational and regiochemistry preferences of 2,4-PEF. The latter polymerizes following a random distribution of monomer orientation, thereby rendering the formation of periodic interchain C-H···O contacts wholly unfeasible and ultimately favoring the formation of randomly coiled chains based on gauche-ethylene glycol segments. In the absence of C-H···O stabilization, the ordered crystalline arrangement is disfavored and polymer chains - adopting several quasi iso-energetic structures - prefer to solidify into an amorphous mess.
Highly transparent films of new copolyesters derived from terephthalic and 2,4-furandicarboxylic acids
Zaidi, Sami ; Thiyagarajan, Shanmugam ; Bougarech, Abdelkader ; Sebti, Fouzia ; Abid, Souhir ; Majdi, Abid ; Silvestre, Armando J.D. ; Sousa, Andreia F. - \ 2019
Polymer Chemistry 10 (2019)39. - ISSN 1759-9954 - p. 5324 - 5332.
In this study transparent films of poly(ethylene terephthalate)-co-(ethylene 2,4-furandicarboxylate) (PET-co-2,4-PEF) copolymers were developed for the first time, exploring the ability of 2,4-furandicarboxylic acid (2,4-FDCA) to impart excellent optical properties to the polymers thereof. The properties were fine-tuned by feeding this furan monomer content. For example, specifically up to 15 mol% the copolyesters were semi-crystalline in nature, and they were amorphous materials when exceeding the limits of 50 mol% and above. The amorphous polymers had excellent thermal stability over 400 °C, in combination with high transmittance at the wavelength of 555 nm.
Protein intake and the incidence of pre-diabetes and diabetes in 4 population-based studies: the PREVIEW project
Sluik, D. ; Brouwer, E.M. ; Berendsen, A.M. ; Mikkilä, V. ; Poppitt, Sally D. ; Silvestre, Marta P. ; Tremblay, A. ; Perusse, L. ; Bouchard, C. ; Raben, Anne ; Feskens, E.J.M. - \ 2019
American Journal of Clinical Nutrition 109 (2019)5. - ISSN 0002-9165 - p. 1310 - 1318.
Background:Data on the relationship between protein intake andthe risk of type 2 diabetes are conflicting.Objectives:We studied prospective associations between the intakeof total, plant-based, and animal protein and the risk of pre-diabetesand diabetes in 4 population-based studies included in the PREVIEWproject.Methods:Analyses were conducted with the use of data from 3 Eu-ropean cohorts and 1 Canadian cohort, including 78,851 participants.Protein intake was assessed through the use of harmonized datafrom food-frequency questionnaires or 3-d dietary records. Cohort-specific incidence ratios (IRs) were estimated for pre-diabetes anddiabetes, adjusting for general characteristics, lifestyle and dietaryfactors, disease history, and body mass index (BMI) and waistcircumference; results were pooled based on a random-effects meta-analysis.Results:Higher total protein intake (g·kg–1·d–1) was associatedwith lower incidences of pre-diabetes and diabetes (pooled IRs: 0.84;95% CI: 0.82, 0.87 and 0.49; 95% CI: 0.28, 0.83, respectively); plant-based protein intake was the main determinant (pooled IRs: 0.83;95% CI: 0.81, 0.86 and 0.53; 95% CI: 0.36, 0.76, respectively).Substituting 2 energy percentage (E%) protein at the expense ofcarbohydrates revealed increased risks of pre-diabetes and diabetes(pooled IRs: 1.04; 95% CI: 1.01, 1.07 and 1.09; 95% CI: 1.01, 1.18,respectively). Except for the associations between intakes of totalprotein and plant-based protein (g·kg–1·d–1) and diabetes, all otherassociations became nonsignificant after adjustment for BMI andwaist circumference.Conclusions:Higher protein intake (g·kg–1·d–1) was associatedwith a lower risk of pre-diabetes and diabetes. Associationswere substantially attenuated after adjustments for BMI and waistcircumference, which demonstrates a crucial role for adiposityand may account for previous conflicting findings. This study wasregistered at ISRCTN as ISRCTN31174892.
Dynamics of the seagrass Zostera noltei in a shallow Mediterranean lagoon exposed to chemical contamination and other stressors
Espel, Diane ; Diepens, Noël J. ; Boutron, Olivier ; Buffan-Dubau, Evelyne ; Chérain, Yves ; Coulet, Eric ; Grillas, Patrick ; Probst, Anne ; Silvestre, Jérôme ; Elger, Arnaud - \ 2019
Estuarine Coastal and Shelf Science 222 (2019). - ISSN 0272-7714 - p. 1 - 12.
Chemical contaminants - Coastal lagoon - Multiple stressors - Seagrass dynamics - Zostera noltei
Seagrass decline due to a variety of stressors has been observed worldwide. In the shallow Vaccarès lagoon, Camargue, France, the dominant macrophyte species, Zostera noltei, has suffered two major declines since 1996. The first decline was well explained by salinity and turbidity variations, while the second one could not be explained by these parameters. Other stressors such as chemical contamination, eutrophication or temperature increase could be explanatory variables for this most recent decline. The aim of our study was to understand, via scientific monitoring from 2011 to 2015, the influence of chemical contamination and its possible interactions with other biological and environmental pressures, on seagrass physiology and population dynamics in the Vaccarès lagoon. Multi-contamination by organic contaminants and trace metals was detected in the water and sediments, and their concentrations often exceeded environmental standards, particularly where seagrass regression was observed. Spatial variations in biological, environmental and chemical parameters in the lagoon were investigated by co-inertia analysis, which revealed significant relationships between environmental data, more particularly between contaminants, seagrass dynamics indices and biomarkers. Seagrass dynamics indices were negatively correlated with the concentrations of some herbicides in water (2,4-MCPA and bentazon) and with trace metals in sediments (arsenic). Rhizome starch contents in winter were negatively correlated with those herbicides and with several metals (arsenic, zinc, copper) in water and/or sediments. These results suggest that environmental contamination may play a role in seagrass decline. However, complementary investigations, such as monitoring over longer periods and additional toxicity tests, are required to address the causal link between contamination and seagrass decline.
PREVIEW study—Influence of a behavior modification intervention (PREMIT) in over 2300 people with pre-diabetes : Intention, self-efficacy and outcome expectancies during the early phase of a lifestyle intervention
Huttunen-Lenz, Maija ; Hansen, Sylvia ; Christensen, Pia ; Larsen, Thomas Meinert ; Sandø-Pedersen, Finn ; Drummen, Mathijs ; Adam, Tanja C. ; Macdonald, Ian A. ; Taylor, Moira A. ; Martinez, J.A. ; Navas-Carretero, Santiago ; Handjiev, Svetoslav ; Poppitt, Sally D. ; Silvestre, Marta P. ; Fogelholm, Mikael ; Pietiläinen, Kirsi H. ; Brand-Miller, Jennie ; Berendsen, Agnes A.M. ; Raben, Anne ; Schlicht, Wolfgang - \ 2018
Psychology Research and Behavior Management 11 (2018). - ISSN 1179-1578 - p. 383 - 394.
Cognition - Diabetes mellitus - Goals - Habits - Weight loss
Purpose: Onset of type 2 diabetes (T2D) is often gradual and preceded by impaired glucose homeostasis. Lifestyle interventions including weight loss and physical activity may reduce the risk of developing T2D, but adherence to a lifestyle change is challenging. As part of an international T2D prevention trial (PREVIEW), a behavior change intervention supported participants in achieving a healthier diet and physically active lifestyle. Here, our aim was to explore the influence of this behavioral program (PREMIT) on social-cognitive variables during an 8-week weight loss phase. Methods: PREVIEW consisted of an initial weight loss, Phase I, followed by a weight-maintenance, Phase II, for those achieving the 8-week weight loss target of ≥ 8% from initial bodyweight. Overweight and obese (BMI ≥25 kg/m2) individuals aged 25 to 70 years with confirmed pre-diabetes were enrolled. Uni-and multivariate statistical methods were deployed to explore differences in intentions, self-efficacy, and outcome expectancies between those who achieved the target weight loss (“achievers”) and those who did not (“non-achievers”). Results: At the beginning of Phase I, no significant differences in intentions, self-efficacy and outcome expectancies between “achievers” (1,857) and “non-achievers” (163) were found. “Non-achievers” tended to be younger, live with child/ren, and attended the PREMIT sessions less frequently. At the end of Phase I, “achievers” reported higher intentions (healthy eating χ2 (1)=2.57; P <0.008, exercising χ2 (1)=0.66; P <0.008), self-efficacy (F(2; 1970)=10.27, P <0.005), and were more positive about the expected outcomes (F(4; 1968)=11.22, P <0.005). Conclusion: Although statistically significant, effect sizes observed between the two groups were small. Behavior change, however, is multi-determined. Over a period of time, even small differences may make a cumulative effect. Being successful in behavior change requires that the “new” behavior is implemented time after time until it becomes a habit. Therefore, having even slightly higher self-efficacy, positive outcome expectancies and intentions may over time result in considerably improved chances to achieve long-term lifestyle changes.
Glutaminolysis and Fumarate Accumulation Integrate Immunometabolic and Epigenetic Programs in Trained Immunity
Arts, Rob J.W. ; Novakovic, Boris ; Horst, Rob ter; Carvalho, Agostinho ; Bekkering, Siroon ; Lachmandas, Ekta ; Rodrigues, Fernando ; Silvestre, Ricardo ; Cheng, Shih Chin ; Wang, Shuang Yin ; Habibi, Ehsan ; Gonçalves, Luís G. ; Mesquita, Inês ; Cunha, Cristina ; Laarhoven, Arjan van; Veerdonk, Frank L. van de; Williams, David L. ; Meer, Jos W.M. van der; Logie, Colin ; O'Neill, Luke A. ; Dinarello, Charles A. ; Riksen, Niels P. ; Crevel, Reinout van; Clish, Clary ; Notebaart, Richard A. ; Joosten, Leo A.B. ; Stunnenberg, Hendrik G. ; Xavier, Ramnik J. ; Netea, Mihai G. - \ 2016
Cell Metabolism 24 (2016)6. - ISSN 1550-4131 - p. 807 - 819.
cholesterol metabolism - epigenetics - glutamine metabolism - glycolysis - trained immunity
Induction of trained immunity (innate immune memory) is mediated by activation of immune and metabolic pathways that result in epigenetic rewiring of cellular functional programs. Through network-level integration of transcriptomics and metabolomics data, we identify glycolysis, glutaminolysis, and the cholesterol synthesis pathway as indispensable for the induction of trained immunity by β-glucan in monocytes. Accumulation of fumarate, due to glutamine replenishment of the TCA cycle, integrates immune and metabolic circuits to induce monocyte epigenetic reprogramming by inhibiting KDM5 histone demethylases. Furthermore, fumarate itself induced an epigenetic program similar to β-glucan-induced trained immunity. In line with this, inhibition of glutaminolysis and cholesterol synthesis in mice reduced the induction of trained immunity by β-glucan. Identification of the metabolic pathways leading to induction of trained immunity contributes to our understanding of innate immune memory and opens new therapeutic avenues.
Altered expression of the bZIP transcription factor DRINK ME affects growth and reproductive development in Arabidopsis thaliana
Lozano-Sotomayor, Paulina ; Chávez Montes, Ricardo A. ; Silvestre-Vañó, Marina ; Herrera-Ubaldo, Humberto ; Greco, Raffaella ; Pablo-Villa, Jeanneth ; Galliani, Bianca M. ; Diaz-Ramirez, David ; Weemen, Mieke ; Boutilier, Kim - \ 2016
The Plant Journal 88 (2016)3. - ISSN 0960-7412 - p. 437 - 451.
Arabidopsis thaliana - bZIP transcription factor - bZIP30 - DRINK ME - growth - meristem activity - reproductive development
Here we describe an uncharacterized gene that negatively influences Arabidopsis growth and reproductive development. DRINK ME (DKM; bZIP30) is a member of the bZIP transcription factor family, and is expressed in meristematic tissues such as the inflorescence meristem (IM), floral meristem (FM), and carpel margin meristem (CMM). Altered DKM expression affects meristematic tissues and reproductive organ development, including the gynoecium, which is the female reproductive structure and is determinant for fertility and sexual reproduction. A microarray analysis indicates that DKM overexpression affects the expression of cell cycle, cell wall, organ initiation, cell elongation, hormone homeostasis, and meristem activity genes. Furthermore, DKM can interact in yeast and in planta with proteins involved in shoot apical meristem maintenance such as WUSCHEL, KNAT1/BP, KNAT2 and JAIBA, and with proteins involved in medial tissue development in the gynoecium such as HECATE, BELL1 and NGATHA1. Taken together, our results highlight the relevance of DKM as a negative modulator of Arabidopsis growth and reproductive development.
Industrial potential of lipoxygenases
Heshof, R. ; Graaff, L.H. de; Villaverde, J.J. ; Silvestre, A.J.D. ; Haarmann, T. ; Dalsgaard, T.K. ; Buchert, J. - \ 2016
Critical Reviews in Biotechnology 36 (2016)4. - ISSN 0738-8551 - p. 665 - 674.
Lipoxygenases (LOXs) are iron- or manganese-containing oxidative enzymes found in plants, animals, bacteria and fungi. LOXs catalyze the oxidation of polyunsaturated fatty acids to the corresponding highly reactive hydroperoxides. Production of hydroperoxides by LOX can be exploited in different applications such as in bleaching of colored components, modification of lipids originating from different raw materials, production of lipid derived chemicals and production of aroma compounds. Most application research has been carried out using soybean LOX, but currently the use of microbial LOXs has also been reported. Development of LOX composition with high activity by heterologous expression in suitable production hosts would enable full exploitation of the potential of LOX derived reactions in different applications. Here, we review the biological role of LOXs, their heterologous production, as well as potential use in different applications. LOXs may fulfill an important role in the design of processes that are far more environmental friendly than currently used chemical reactions. Difficulties in screening for the optimal enzymes and producing LOX enzymes in sufficient amounts prevent large-scale application so far. With this review, we summarize current knowledge of LOX enzymes and the way in which they can be produced and applied
Species composition and phytosociology of xerophytic plant communities after extreme rainfall in South Peru
Montesinos, D.B. ; Sykora, K.V. ; Quipuscoa-Silvestre, Victor ; Cleef, A.M. - \ 2015
Phytocoenologia 45 (2015)3. - ISSN 0340-269X - p. 203 - 250.
We present a phytosociological overview of the arid and semi-arid montane vegetation of the province of Arequipa in southern Peru. The xerophytic vegetation was studied after extreme rainfall had promoted exceptionally lush vegetation and a high aboveground floristic diversity. We used TWINSPAN for classification and Detrended Correspondence Analysis for gradient analysis of our relevés. PC-ORD was used to show the hierarchical similarity structure of the syntaxa, and to compare them with related communities in Peru and surrounding countries from literature. We present a synoptic table, and describe the physiognomy, floristic composition, ecology and spatial distribution of the plant communities. In total, we recorded 187 plant species, including 50 endemics, in 196 phytosociological relevés distributed over 2030 km2 at an elevation between 2020 and 3260 m a. s. l. The relevés were assigned to three alliances in the class Opuntietea sphaericae. The vegetation consists mainly of native species of trees, shrubs, grasses, succulents, annual herbs, and ferns. The most diverse families were Asteraceae, Cactaceae, Solanaceae, Malvaceae, Boraginaceae, Fabaceae, Poaceae, Amaranthaceae and Pteridaceae. Within the class Opuntietea sphaericae, three alliances have been distinguished of which two are new. The Ambrosio artemisioidis-Weberbauerocerion weberbaueri comprising six associations was recorded on barren hillsides between 2000 and 2900 m a. s. l. in the Arequipa city boundary zones. The Corryocaction brevistyli defines xerophytic scrub between 2700 and 3200 m a. s. l. in semi-dry regions bordering the puna grasslands. It contains the Balbisio weberbaueri-Ambrosietum artemisioidis and the Aloysio spathulatae-Corryocactetum brevistyli, all in need of further investigation as they lack diagnostic species. A unit clearly distinguished by Weberbauerocereus rauhii and Neoraimondia arequipensis is here described as a new alliance, Neoraimondio arequipensis-Weberbauerocerion rauhii. It grows in inter-Andean valleys in dry regions (1100– 2200 m a. s. l.), with abundant cacti accompanied by few xerophytes.
Hydroperoxide production from linoleic acid by heterologous Gaeumannomyces graminis tritici lipoxygenase: Optimization and scale-up
Villaverde, J.J. ; Vlist, V. van der; Santos, S.A.O. ; Haarmann, T. ; Langfelder, K. ; Pirttimaa, M. ; Nyyssola, A. ; Jylhä, S. ; Tamminen, T. ; Kruus, K. ; Graaff, L.H. de; Pascoal Neto, C. ; Simoes, M.M.Q. ; Domingues, M.R.M. ; Silvestre, A.J.D. ; Eidner, J. ; Buchert, J. - \ 2013
Chemical Engineering Journal 217 (2013). - ISSN 1385-8947 - p. 82 - 90.
unsaturated fatty-acids - soybean lipoxygenase - immobilized lipoxygenase - manganese lipoxygenase - mass-spectrometry - oxidation - identification - system - state - oil
Linoleic acid was converted into hydroperoxides by a Gaeumannomyces graminis tritici lipoxygenase produced recombinantly in Trichoderma reesei. Hydroperoxide production was optimized using a face-centred experimental design in order to study the effects of pH, temperature and time on the conversion of linoleic acid into four regioisomeric hydroperoxyoctadecadienoic acids (HPODE): 13-(Z,E)-, 9-(E,Z)-, 13-(E,E)-, 9-(E,E)-HPODE. Fitting equations described satisfactorily the system behavior and showed that reaction time was the most influencing independent variable. A set of independent variables (pH = 6.7, temperature = 23.9 °C and time = 18 h) allowed to obtain high yields of hydroperoxides (88.0%) with a good selectivity for the 13-(Z,E)-HPODE isomer (47.4%) when the initial substrate concentration was 10 g/L. The production was further investigated using industrially relevant linoleic acid concentrations (100–300 g/L) leading to HPODE yields of ~40% and the volumetric productivity 3.6 g/(L h), and a selectivity for 13-(Z,E)-HPODE of around 74%
Wheat gluten films cross-linked with 1-ethyl-3-(3-demethylaminopropyl) carbodiimide and N-hydroxysuccinimide
Tropini, V. ; Lens, J.P. ; Mulder, W.J. ; Silvestre, F. - \ 2004
Industrial Crops and Products 20 (2004)3.. - ISSN 0926-6690 - p. 281 - 289.
water-vapor permeability - protein-based films - edible wheat - mechanical-properties - barrier properties - plasticizers - linking - polymers - property - corn
Wheat gluten films were cast from aqueous dispersions containing 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as cross-linking reagents and glycerol as a plasticizer. Cross-linking was carried out to improve film properties such as water sensitivity and tensile strength. Films were characterized by measuring protein and water content, amount of amino groups, swelling of the films in water, and mechanical properties such as tensile strength (sigma(max)) and strain at maximum stress (epsilon at (sigma(max)). The use of different ratios of EDC to COOH resulted in different tensile properties and different percentage of swelling, which was attributed to the degree of cross-linking in the film. At a ratio of EDC/NHS/COOH = 0.5/0.5/1, films had a water content of 10-11.5% and showed the highest sigma(max) (2.8 +/- 0.9 MPa), the lowest a at sigma(max) (142 +/- 67%), and the lowest swelling (46%) compared to sigma(max) = 1.7 +/- 0.4 MPa, epsilon at sigma(max) = 257 +/- 63%, and swelling = 68% for native gluten films. (C) 2003 Published by Elsevier B.V.
Cross-linking of wheat gluten using a water-soluble carbodiimide
Tropini, V. ; Lens, J.P. ; Mulder, W.J. ; Silvestre, F. - \ 2000
Cereal Chemistry 77 (2000)3. - ISSN 0009-0352 - p. 333 - 338.
Wheat gluten was cross-linked using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl (EDC). To enhance cross-linking, N-hydroxysuccinimide (NHS) was added to the reaction mixture. The cross-linking efficiency was evaluated by the decrease in the amount of amino groups, the solubility of the protein in aqueous solutions with different pH levels, and by the change in the molecular weight distribution of the cross-linked compounds. Cross-linking was dependent on the reaction time, the molar ratio of added reactants, and the pH level of the reaction mixture. If the reaction was carried out at pH 3, no decrease in the amount of amino groups or solubility was observed. At pH 5–7, the amount of amino groups decreased from 15 to 10 mmol/100 g of protein. This was accompanied by a large decrease in the water solubility of the protein (<10%, w/v). Finally, reaction at pH 11 decreased the amount of amino groups from 15 to 8 mmol/100 g of protein. However, hardly any decrease in the water solubility was observed. Based on these results and SDS-PAGE experiments, two cross-link mechanisms are suggested: one resulting in inter- and the other resulting in intramolecular cross-links.
|A population dynamic approach to the control of Anthriscus sylvestris (L.) Hoffm.
Mierlo, J.E.M. ; Groenendael, J.M. van - \ 1991
Journal of Applied Ecology 28 (1991). - ISSN 0021-8901 - p. 128 - 139.