| 1. |
- Alimohammadzadeh, Rana
(författare)
-
Eco-friendly and Catalytic Surface Engineering of Cellulose and Nanocellulose
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The non-stop use of petroleum-based materials such as plastics can generate significant environmental problems, including pollution of the oceans and increased CO2 levels, and cause diseases like cancer due to the starting monomers. Consequently, increased use of sustainable and non-toxic polymers and monomers is required to address these issues. Cellulose, generously supplied by Mother Nature, is the most abundant biopolymer on Earth. Nanocellulose is a sustainable polymer extracted from the cellulose inwood or produced by bacteria and algae. This biodegradable nanomaterialhas recently been receiving intense research attention, since it has great potential for use in a broad range of industrial and biomedical applications. However, it has limitations such as moisture sensitivity and incompatibility with hydrophobic materials due to its hydrophilic nature. Chemical modification is necessary for it to fulfill the requirements for applications that require high moisture resistance and water repellency. Unfortunately, several of the existing methods involve harsh and toxic conditions or reagents. In this thesis, together with my co-workers, I have employed the toolbox of organocatalysis for accomplishing eco-friendly and innovative surface modification of cellulose and nanocellulose. The organocatalysts we usedmost in our research are the naturally abundant and industrially relevantorganic acids tartaric acid and citric acid.Direct catalytic esterification of cellulose nanocrystal (CNC) with thioglycolicacid was performed either in suspension or on solid surfaces such as films and foams. We found that the reaction was accelerated by tartaric acid but could also be autocatalytic with respect to the thioglycolic acid under certain conditions. The synthesized CNC-SH was further exploited as a heterogeneous reducing agent as well as a handle for further nanocellulose modifications. This was demonstrated by using CNC-SH as a heterogenous reducing agent of Cu(II) to Cu(I), which is essential for allowing the Cu to actas a catalyst for 2,3-dipolar cycloaddition reactions between azides andalkynes. We also showed that the thia-modified CNC could undergo further functionalizing via thiol-ene click chemistry reactions, for example, we attached fluorescent compounds such as TAMRA and quinidine.Herein we provide a fluorine-free method to prepare superhydrophobic CNC film with excellent water-resistance properties by combining self-assemblyand organocatalysis. Self-assembly of CNC via vacuum filtration resulted in xa film with a specific roughness at the microscale. Next, the catalytic silylation with a variety of alkoxysilanes in the presence of natural organic acids such as tartaric acid and citric acid was performed. The successful implementation of our method resulted in a super-hydrophobic CNC film (water contact angleover 150°) with excellent water-resistance. Thus, the combination of the selfassembly of a rough surface with catalytic surface modification resulted in a phenomenon like the “lotus effect” as exhibited by the leaves of the lotus flower. An investigation of the oxygen permeability of the octadecyltrimethoxysilane-modified CNC film revealed that it significantly decreased at high relative humidity compared with unmodified CNC films.In this thesis, the fabrication of hydrophobic and functionalized MTM/CNF nanocomposites using organocatalytic surface modification with a large variety of alkoxysilanes is also performed. The surface modifications are mildand the mechanical strength of the Nacre-mimetic nanocomposites is preserved. Elemental mapping analysis revealed that the silane modification occurred predominantly on the surface.A combination of organocatalyst and biopolyelectrolyte complex was appliedfor surface engineering of chemi-thermomechanical pulp (CTMP) and bleached sulfite pulp (BSP). The reaction was performed using a synergistic combination of an organocatalyst with a polyelectrolyte (PE) complex. Using this method, the strength properties of CTMP and BSP sheets were significantly increased (up to 100% in Z-strength for CTMP). Further investigations of the distribution of the PE complex were then performed using TAMRA and quinidine labeling and confocal laser scanningmicroscopy. This revealed that an even distribution of the cationic starch component of the PE complex had occurred within the CTMP-based paper sheets, which follows its lignin distribution pattern.
|
|
| 2. |
- Granholm, Fredrik, et al.
(författare)
-
A Feasibility Study on the Identification of Potential Biomarkers in Pulmonary Embolism Using Proteomic Analysis
- 2022
-
Ingår i: Clinical and applied thrombosis/hemostasis. - : SAGE Publications. - 1076-0296 .- 1938-2723. ; 28
-
Tidskriftsartikel (refereegranskat)abstract
- Acute pulmonary embolism (PE) is a common emergency with a high morbidity and mortality. Most clinical presentations are non-specific and there is a lack of suitable biomarkers for PE. For example, the traditional D-dimer tests shows a rather high sensitivity for PE, but yet a rather low positive predictive value due to its lack of specificity. Research on novel biomarkers for PE is thus of interest to improve early diagnostics and reduce the number of unnecessary computed tomography pulmonary angiogram (CTPA) scans performed. In this study we evaluate the feasibility to use label-free quantitative proteomics to discover potential biomarkers for acute PE and to monitor changes in proteins levels in PE patients over time. Blood was collected from 8 patients with CTPA verified PE and from 8 patients presenting with same symptoms but with a negative CTPA. The samples were analyzed by liquid chromatography-mass spectrometry and thirteen protein concentrations were found to be significantly changed in PE patients compared to the CTPA negative controls. This exploratory study shows that proteomic analysis can be used to identify potential biomarkers for PE as well as to monitor changes of protein levels over time. The complement proteins play a part in PE but further studies are needed to clarify their specific role in the pathophysiological process and to look for more specific proteins.
|
|
| 3. |
- Henriksson, Anders E., et al.
(författare)
-
Identification of Potential Plasma Biomarkers for Abdominal Aortic Aneurysm Using Tandem Mass Tag Quantitative Proteomics
- 2018
-
Ingår i: Proteomes. - : MDPI AG. - 2227-7382. ; 6:4
-
Tidskriftsartikel (refereegranskat)abstract
- Plasma biomarkers that identify abdominal aortic aneurysm (AAA) rupture risk would greatly assist in stratifying patients with small aneurysms. Identification of such biomarkers has hitherto been unsuccessful over a range of studies using different methods. The present study used an alternative proteomic approach to find new, potential plasma AAA biomarker candidates. Pre-fractionated plasma samples from twelve patients with AAA and eight matched controls without aneurysm were analyzed by mass spectrometry applying a tandem mass tag (TMT) technique. Eight proteins were differentially regulated in patients compared to controls, including decreased levels of the enzyme bleomycin hydrolase. The down-regulation of this enzyme was confirmed in an extended validation study using an enzyme-linked immunosorbent assay (ELISA). The TMT-based proteomic approach thus identified novel potential plasma biomarkers for AAA.
|
|
| 4. |
- Ljunggren, Joel, et al.
(författare)
-
Antifungal efficiency of individual compounds and evaluation of non-linear effects by recombining fractionated turpentine
- 2020
-
Ingår i: Microchemical journal (Print). - : Elsevier BV. - 0026-265X .- 1095-9149. ; 153
-
Tidskriftsartikel (refereegranskat)abstract
- A combination between a reductive and a holistic assay was employed to investigate whole fraction, synergistic, antagonistic and individual compound efficacy of vacuumdistilled turpentine fractions against the economically important brown-rot fungus Coniophora puteana. The fungus was subjected to recombinations of turpentine fractions at a concentration of 1000 ppm. All combinations exhibited useful antifungal properties, but some antifungal mixtures showed a more pronounced effect than the expected level of inhibition. Synergistic effects by a two-fold factor and minor antagonistic effects were observed. Complete growth inhibition of C. puteana was observed by a fraction obtained after distilling 1 L turpentine at 111–177°C (0.5 mbar) as well as by mixing it with another fraction withdrawn at 70–79°C (0.5 mbar). Chemical compositions of distilled fractions were determined through GC–MS analysis and Orthogonal Partial Least Squares (OPLS) multivariate data analysis of GC–MS chromatograms was employed to zoom in on the most active compounds responsible for antifungal activity. Isomers of epicubenol, the hydrocarbon aromatic compound ar-himachalene and α-cadinol are suggested as effective antifungal compounds. In addition, a subsequent fractionation of the most effective fraction was performed with preparatory gas chromatography and subfractions showed similar or better efficacy than previously observed. Our work demonstrates the possibility to retain adequate synergistic antifungal efficiency and offers an opportunity to explore the effects of individual compounds originating from the same crude sample.
|
|
| 5. |
- Ljunggren, Joel, et al.
(författare)
-
Evaluation of fractionally distilled Picea abies TMP-turpentine on wood-decaying fungi : in vitro, microcosm and field experiments
- 2020
-
Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 0043-7719 .- 1432-5225. ; 54, s. 847-868
-
Tidskriftsartikel (refereegranskat)abstract
- Synthetic and heavy metal antifungals are frequently used as wood preservatives. However, they exhibit relatively inert biodegradation and toxic properties when leached; this makes their replacement with environmentally degradable yet functional alternatives a key target in the wood protection industry. In this context, distilled fractions of raw thermomechanical pulp turpentine (TMP-T) from Picea abies were assessed for their wood protecting capabilities against wood-decaying fungi. Antifungal bioactivity of fractions and some of their combinations were screened on agar-plates against the brown-rot fungus Coniophora puteana. Addition of TMP-T fractions showed a significant fungal growth rate reduction, while mixtures indicated the presence of synergistic and antagonistic effects. One fraction, obtained after distilling 1 L TMP-T at 111–177 °C at 0.5 mbar, showed complete growth inhibition of Antrodia sinuosa, Serpula lacrymans, Serpula himantioides and significant inhibition of Antrodia serialis, Antrodia xantha, Gloeophyllum sepiarium, Heterobasidion parviporum at a concentration of 1000 ppm. This fraction was further examined for long- and medium-term effects on wood decay in microcosm soil-jar and field experiment, respectively. The known antifungal compounds benzisothiazolinone, 2-octyl-4-isothiazolin-3-one, 3-iodo-2-propynyl N-butylcarbamate and two commercial wood preservatives were used as reference treatments. Commercial preservatives instilled long-term efficacy against C. puteana wood decay in a soil-jar microcosm experiment, but no noticeable protection with antifungal compounds or the present treatments was found. However, a moderate effect by the TMP-T fraction from the in vitro assay was observed and the TMP-turpentine distillation residue showed a similar fungal inhibition effect to the most potent commercial treatment after 29 months in the field.
|
|
| 6. |
- Olofsson, Madelen, 1981-, et al.
(författare)
-
Analysis of hydroxamate siderophores in soil solution using liquid chromatography with mass spectrometry and tandem mass spectrometry with on-line sample preconcentration
- 2015
-
Ingår i: Journal of Separation Science. - Weinheim : Wiley-VCH Verlagsgesellschaft. - 1615-9306 .- 1615-9314. ; 38:19, s. 3305-3312
-
Tidskriftsartikel (refereegranskat)abstract
- A liquid chromatography-electrospray ionization-mass spectrometry method was developed to quantitatively and qualitatively analyze thirteen hydroxamate siderophores (ferrichrome, ferrirubin, ferrirhodin, ferrichrysin, ferricrocin, ferrioxamine B, D1, E and G, neocoprogen I and II, coprogen and triacetylfusarinine C). Samples were pre-concentrated on-line via switch-valve setup prior to analyte separation on a Kinetex C18 column. Gradient elution was performed using a mixture of an ammonium formate buffer and acetonitrile. Total analysis time including column conditioning was 20.5 minutes. Analyte were fragmented by applying collision induced dissociation, enabling structural identification via tandem mass spectrometry. Limit of detection values for the selected ion monitoring method ranged from 71 pM to 1.5 nM with corresponding values of two to nine times higher for the multiple reaction monitoring method. The liquid chromatography-mass spectrometry method resulted in a robust and sensitive quantification of hydroxamate siderophores as indicated by retention time stability, linearity, sensitivity, precision and recovery. The analytical error of the methods, assessed trough random-order, duplicate analysis of soil samples extracted with a mixture of 10 mM phosphate buffer and methanol, appears negligible in relation to between-sample variations.
|
|
| 7. |
- Olofsson, Madelen, 1981-, et al.
(författare)
-
Effects of mineral amendment on soil chemistry parameters reflecting microbial activity in a Swedish boreal forest soil
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Samples of apatite, biotite and oligoclase were incubated in different soil horizons of a boreal forest podzol in central Sweden. After four years, soil from the bulk and the surfaces of the minerals were extracted and analyzed in regard to fungal biomass, enzymatic activity, low molecular mass organic acids and hydroxamate siderophores. The nutrient status of the study area was evaluated using historical data from foliar and soil solution analysis. Soil solution indicated a possible shortage of P in the mineral soil even though foliar content was above target levels. The foliar analysis instead revealed possible shortage of Fe. Apatite is the primary source of inorganic P in soil and biotite is rich in Fe compared to the soil at the site, and it was hypothesized that both minerals could be attractive sources of weatherable mineral nutrients, hence associated with higher microbial activity. Parameters measured as indicators of microbial activity revealed few significant (p<0.05) differences between the minerals and bulk soil in the O horizon, probably due to large variations among replicates, although an overall higher microbial activity was found in the bulk soil. In the E horizon a distinct trend appeared indicating higher levels of low molecular mass organic acids, enzymatic activity and fungal biomass associated with the biotite mineral, although this observation was only found to be significant for some of the parameters when analyzed individually. No clear trends were observed in the B horizon.
|
|
| 8. |
- Olofsson, Madelen, 1981-, et al.
(författare)
-
Evaluation of sampling and sample preparation procedures for the determination of aromatic acids and their distribution in a podzol soil using liquid chromatography-tandem mass spectrometry
- 2014
-
Ingår i: Geoderma. - Amsterdam : Elsevier. - 0016-7061 .- 1872-6259. ; 232-234, s. 373-380
-
Tidskriftsartikel (refereegranskat)abstract
- In this work the distribution of free and weekly adsorbed aromatic acids (phthalic acid and ten phenolicacids; gallic, p-hydroxybenzoic, salicylic, vanillic, protocatechuic, p-coumaric, syringic, sinapic, ferulic and caffeicacid), which could participate in weathering and soil formation processes, were studied for O, E and Bhorizons in a podzol soil in central Sweden. For the analysis a simple and rapid quantitative and qualitative liquidchromatography–tandem mass spectrometry method (using gradient elution) was developed with LODs rangingfrom 5 to 25 nM. Different soil solution sampling techniques (tension-lysimeter and soil centrifugation) and soilextraction with either 10 mM phosphate buffer (pH 7.2) or 50:50 (v/v) 10 mM phosphate buffer:MeOHwere compared. All eleven acids were found in detectable or trace concentrations. The most abundant aromaticacids were vanillic and phthalic acid with concentrations around 1 μM for O and E horizon respectively.Lysimeter samples resulted in the lowest concentrations followed by centrifugation samples. Ingeneral, buffer:MeOH extraction resulted in the highest concentrations for the O horizon, likely due toMeOH's ability to compete for hydrophobic sites on soil organic matter (SOM). Then again, pure bufferwith its higher ion strength, interfering with the acids electrostatic interactions with clay particles, leads tohigher extracted concentrations for the E and B horizons. Since the efficiency of the extraction solutions, to alarge extent, depends on the sample properties, a general approach is hard to appoint. However, the extractionof substituted cinnamic acids is in general facilitated by adding MeOH to the extraction solution. The use of statisticalmethods for the evaluation of the results showed a large and significant difference in aromatic acid concentrationsreceived using different sampling techniques and sample preparations. In fact, sampling methodsresulted in higher variations in aromatic acid concentrations than sampled horizon.
|
|
| 9. |
- Olofsson, Madelen, 1981-, et al.
(författare)
-
Liquid Chromatography with Electrospray Ionization and Tandem Mass Spectrometry Applied in the Quantitative Analysis of Chitin-Derived Glucosamine for a Rapid Estimation of Fungal Biomass in Soil
- 2016
-
Ingår i: International Journal of Analytical Chemistry. - : Hindawi Publishing Corporation. - 1687-8760 .- 1687-8779.
-
Tidskriftsartikel (refereegranskat)abstract
- This method employs liquid chromatography-tandem mass spectrometry to rapidly quantify chitin-derived glucosamine for estimating fungal biomass. Analyte retention was achieved using hydrophilic interaction liquid chromatography, with a zwitter-ionic stationary phase (ZIC-HILIC), and isocratic elution using 60 % 5 mM ammonium formate buffer (pH 3.0) and 40 % ACN. Inclusion of muramic acid, and its chromatographic separation from glucosamine, enabled calculation of the bacterial contribution to the latter. Galactosamine, an isobaric isomer to glucosamine, found in significant amounts in soil samples, was also investigated. The two isomers form the same precursor and product ions, and could not be chromatographically separated using this rapid method. Instead, glucosamine and galactosamine were distinguished mathematically, using the linear relationships describing the differences in product ion intensities for the two analytes. The m/z transitions of 180→72 and 180→84 were applied for the detection of glucosamine and galactosamine and that of 252→126 for muramic acid. Limits of detection were in the pico-molar range for all included analytes. The total analysis time was 6 min, providing a high sample through-put method.
|
|
| 10. |
|
|
