| 1. |
- Aldaeus, Fredrik, et al.
(författare)
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The supramolecular structure of cellulose-rich wood pulps can be a determinative factor for enzymatic hydrolysability
- 2015
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Ingår i: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 22:6, s. 3991-4002
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Tidskriftsartikel (refereegranskat)abstract
- The enzymatic hydrolysability of three industrial pulps, five lab made pulps, and one microcrystalline cellulose powder was assessed using commercial cellulolytic enzymes. To gain insight into the factors that influence the hydrolysability, a thorough characterization of the samples was done, including their chemical properties (cellulose content, hemicellulose content, lignin content, and kappa number), their macromolecular properties (peak molar mass, number-average molar mass, weight-average molar mass, polydispersity, and limiting viscosity) and their supramolecular properties (fibre saturation point, specific surface area, average pore size, and crystallinity). The hydrolysability was assessed by determination of initial conversion rate and final conversion yield, with conversion yield defined as the amount of glucose in solution per unit of glucose in the substrate. Multivariate data analysis revealed that for the investigated samples the conversion of cellulose to glucose was mainly dependent on the supramolecular properties, such as specific surface area and average pore size. The molar mass distribution, the crystallinity, and the lignin content of the pulps had no significant effect on the hydrolysability of the investigated samples.
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| 2. |
- Carlén, A, et al.
(författare)
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Surface characteristics and in vitro biofilm formation on glass ionomer and composite resin
- 2001
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Ingår i: Biomaterials. - 0142-9612 .- 1878-5905. ; 22, s. 481-487
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Tidskriftsartikel (refereegranskat)abstract
- In the initial stages of dental plaque formation, early colonizing bacteria bind to receptor structures in the pellicle, a proteinaceous film formed instantly after cleaning of the tooth surface. Dental restorative materials with surface characteristics different from the tooth might affect pellicle formation and the ability of bacteria to colonize the oral cavity. in this study (i) roughness and chemical composition of glass ionomer and composite resin surfaces before and after polishing, and (ii) the adsorption of salivary proteins and bacterial adherence to the pellicle-coated surfaces were examined. Compared with unpolished composite resin, unpolished glass ionomer had higher surface roughness, contained more inorganic, positively charged components, collected more proteins, and promoted better bacterial adherence. Polishing had the most pronounced effect on the composite resin, giving an enlarged and a rougher surface with a more inorganic character. Polishing the composite resin also led to increased biofilm formation
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| 3. |
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| 4. |
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| 5. |
- Baison, John, et al.
(författare)
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Genome-Wide Association Study (GWAS) identified novel candidate loci affecting wood formation in Norway spruce
- 2019
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Ingår i: The Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 100:1, s. 83-100
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Tidskriftsartikel (refereegranskat)abstract
- Norway spruce is a boreal forest tree species of significant ecological and economic importance. Hence there is a strong imperative to dissect the genetics underlying important wood quality traits in the species. We performed a functional Genome-Wide Association Study (GWAS) of 17 wood traits in Norway spruce using 178101 single-nucleotide polymorphisms (SNPs) generated from exome genotyping of 517 mother trees. The wood traits were defined using functional modelling of wood properties across annual growth rings.We applied a LASSO based association mapping method using a functional multi-locus mapping approach that utilizes latent traits, with a stability selection probability method as the hypothesis testing approach to determine significant Quantitative Trait Loci (QTLs). The analysis provided 52 significant SNPs from 39 candidate genes, including genes previously implicated in wood formation and tree growth in spruce and other species. Our study represents a multi-locus GWAS for complex wood traits in Norway spruce. The results advance our understanding of the genetics influencing wood traits and identifies candidate genes for future functional studies.
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| 6. |
- Carmona, Pierre, 1995, et al.
(författare)
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Controlling the structure of spin-coated multilayer ethylcellulose/ hydroxypropylcellulose films for drug release
- 2023
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Ingår i: International Journal of Pharmaceutics. - 0378-5173 .- 1873-3476. ; 644
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Tidskriftsartikel (refereegranskat)abstract
- Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. Water-soluble HPC leaches out and forms a porous structure that controls the drug transport. Industrially, the pellets are coated using a fluidized bed spraying device, and a layered film exhibiting varying porosity and structure after leaching is obtained. A detailed understanding of the formation of the multilayered, phase-separated structure during production is lacking. Here, we have investigated multilayered EC/HPC films produced by sequential spin-coating, which was used to mimic the industrial process. The effects of EC/HPC ratio and spin speed on the multilayer film formation and structure were investigated using advanced microscopy techniques and image analysis. Cahn-Hilliard simulations were performed to analyze the mixing behavior. A gradient with larger structures close to the substrate surface and smaller structures close to the air surface was formed due to coarsening of the layers already coated during successive deposition cycles. The porosity of the multilayer film was found to vary with both EC/HPC ratio and spin speed. Simulation of the mixing behavior and in situ characterization of the structure evolution showed that the origin of the discontinuities and multilayer structure can be explained by the non-mixing of the layers.
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| 7. |
- Elftonson, JE, et al.
(författare)
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Adhesion of Streptococcus sanguis to porous and non-porous substrates with well-defined surface energies
- 1996
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Ingår i: Journal of Adhesion Science and Technology. - 0169-4243 .- 1568-5616. ; 10, s. 761-770
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Tidskriftsartikel (refereegranskat)abstract
- Adhesion of the oral bacterium Streptococcus sanguis was investigated on two series of surfaces, one solid, non-porous and one porous with a pore diameter centered around 0.2 µm. Each series consisted of four substrates with varying surface free energies: pure aluminum oxide, PEG modified aluminum oxide, and two types of silanized aluminum oxide. The surface composition was analyzed by ESCA and the surface free energy and acid-base character were determined by contact angle measurement using water, formamide and diiodomethane according to Van Oss and Good. Contact angle measurements were conducted on non-porous substrates which had been subjected to the same silanization procedure as the porous ones. Untreated aluminum oxide and PEG modified aluminum oxide were both hydrophilic and gave water contact angles of less than 10°. One silanization procedure gave a surface of intermediate hydrophobicity, with a y-tot of 47.5 mN/m; the other gave a strongly hydrophobic surface of y-tot = 27.4 mN/m. Adhesion of S. sanguis was measured by using radiolabelled bacteria. It was demonstrated that more bacteria adhered to the porous than to the non_x001F_porous substrate and that the PEG treatment, as well as the two sil aniz ation pro cedures, resulted in a decreas e in bacterial adhesion, b oth to the controls treated with aqueous buffer and to surfaces treated with fresh saliva.
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| 8. |
- Garg, Neeraj, et al.
(författare)
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Chemoselective Probe Containing a Unique Bioorthogonal Cleavage Site for Investigation of Gut Microbiota Metabolism
- 2018
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 57:42, s. 13805-13809
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Tidskriftsartikel (refereegranskat)abstract
- While metabolites derived from gut microbiota metabolism have been linked to disease development in the human host, the chemical tools required for their detailed analysis and the discovery of biomarkers are limited. A unique and multifunctional chemical probe for mass spectrometric analysis, which contains p-nitrocinnamyloxycarbonyl as a new bioorthogonal cleavage site has been designed and synthesized. Coupled to magnetic beads, this chemical probe allows for straightforward extraction of metabolites from human samples and release under mild conditions. This isolation from the sample matrix results in significantly reduced ion suppression, an increased mass spectrometric sensitivity, and facilitates the detection of metabolites in femtomole quantities. The chemoselective probe was applied to the analysis of human fecal samples, resulting in the discovery of four metabolites previously unreported in this sample type and confirmation of the presence of medically relevant gut microbiota-derived metabolites.
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