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  • 101.
    Engqvist, Cecilia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andreasson, B
    Karlsson, O
    Lund University.
    Interactions between single latex particles and silica surfaces studied with AFM2007In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 302, no 1-3, p. 197-203Article in journal (Refereed)
    Abstract [en]

    The spreading of single styrene-acrylic latex particles on silicon oxide surfaces was studied using atomic force microscopy (AFM). Three latexes with different glass transition temperature (Tg) were used and the effects of temperature, time and preparation method were investigated. Particle sizes and shape were measured with AFM and the contact angles were calculated. The observed rate for the spreading of latex particles was low and it took several days before the particles reached steady state, even at temperatures well above their Tg. The experimental particle spreading results deviated with two orders of magnitude from predictions using the WLF equation for polymer diffusion. The deviation could be attributed to polymer-surface interactions that slowed down the particle spreading. The work of adhesion was calculated using two models. The results from using the regular Young-Dupré equation and a modified version of this equation that also included the mechanical properties (E-modulus and Poisson�s ratio) of the latexes, were compared. For soft latex particles the results from the two models agreed well and were of the order of 75 J/m2, but for glassy latexes the Young-Dupré equation underestimated the work of adhesion.

  • 102.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    UV-Vis spectrophotometry for analyzing the exfoliation of graphite in aqueous solutions2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Graphene has generated a great deal of interest all over the world in the last decade, mainly as a result of its unique properties such as high con-ductance and strength, which is of potential benefit for many electronic applications. One common strategy for producing increased quantities of few-layer graphene includes liquid-based methods, where graphite is peeled off or exfoliated. Ultraviolet-Visible (UV-Vis) spectrophotometry can be used for measuring the degree of exfoliation since the optical ab-sorbance at a given amount of graphite increases with the degree of exfo-liation. In this work, a UV-Vis method was tested where the exfoliated samples were stabilized with glycerol. This enabled measurements of both polydisperse samples directly after the exfoliation and also top-phase samples collected after gravitational sedimentation. Beer-Lam-bert’s law could be applied for quantifying the amount of exfoliated graphite in the samples. The samples were analyzed by focusing on the connection between absorbance, extinction and light scattering. It was found that the particle size and the contribution from light scattering de-creased at the presence of smaller particle sizes. It was also evident that the absorbance peak of graphite was shifted toward higher wavelengths as the exfoliation was progressed by repeated shearing. These are intri-guing results that warrant further studies as well as verification by alter-native spectroscopic analysis.In order to investigate the change in absorbance with different chemical and mechanical exfoliation conditions, studies were performed using a high-pressure capillary viscometer, ACAV A2. It was clear that an addi-tion of 2% polyacrylic acid (PAA) facilitated mixing and also increased the amount of dispersed graphite by more than six times. The mechanical treatment showed that both high-pressure shearing and sonication gave higher concentrations of nanographite compared to mechanical disper-sion by a rotary disperser. The overall conclusion of this study is that a combination of analysis is required for characterizing the particles. In or-der to quantify graphene, the analysis of chemical structure, inter-particle stability and flake cleanliness is very important.

  • 103.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Månsson, Per
    Schlyter, Fredrik
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Strategier i sökandet efter gnaghämmare mot snytbaggen, Hylobius abietis: Föredrag, 19:e Organikerdagarna i Linköpng 20042004Conference paper (Other academic)
  • 104.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Månsson, P. E.
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Schlyter, F
    Antifeedants and feeding stimulants in bark extracts of ten woody non-host species of the pine weevil, Hylobius abietis.2008In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 34, no 10, p. 1290-1297Article in journal (Refereed)
  • 105.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Månsson, P
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Searching for Pine Weevil Antifeedants: Finding an Active Compound in Bark from Linden, Tilia cordata: Joint meeting of International Society of Chemical Ecology and Phytochemical Society of North America, Ottawa, Canada 20042004Conference paper (Other academic)
  • 106.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schlyter, F
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Benzaldehyde, cinnamic aldehyde and related compounds as antifeedants against the pine weevil, Hylobius abietis: A study of structure-activity relationships.Manuscript (Other academic)
  • 107.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schlyter, F
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Syntes av 2,6-disubstituerade piperidinalkaloider, potentiella gnaghämmare mot snytbaggen Hylobius abietis: 20:e Organikerdagarna, 12-15 juni 2006, Kalmar, föredrag2006Conference paper (Other academic)
  • 108.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schlyter, Fredrik
    Swedish University of Agricultural Sciences, Alnarp.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Synthesis of (+)- and (-)-dihydropinidine by diastereoselective dimethylzinc promoted allylation of 2-methyltetrahydropyridine-N-oxide with allylboronic ester.2006In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 17, no 7, p. 1074-1080Article in journal (Refereed)
    Abstract [en]

    The enantiomers of the naturally occurring alkaloid dihydropinidine 1, potential antifeedants against the pine weevil, Hylobius abietis, were prepared by diastereoselective, dimethylzinc mediated addition of pinacolyl 2-propenylboronate 14 to nitrones (R)- and (S)-2-methyl tetrahydropyridine-N-oxide 3, prepared from d- and l-alanine, respectively.

  • 109.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Smitt, O.
    Schlyter, F.
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Antifeedants for Protection of Pines and Spruces against the Pine Weevil, Hylobius abietis: International Society of Chemical Ecology, Annual Meeting 2001, Lake Tahoe, USA2001Conference paper (Other academic)
  • 110.
    Eriksson, Carina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Smitt, Olof
    Schlyter, Fredrik
    Sjödin, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Searching for Pine Weevil Antifeedants, Strategy and Synthesis2002In: 19th annual meeting of International Society of Chemical Ecology, 2002, Hamburg, Germany, 2002, p. 217-Conference paper (Other academic)
  • 111.
    Essén, Sofia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Moberg, M
    Uppsala University.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Quantification of hydroxamate siderophores in soil solutions of podzolic soil profiles in Sweden2006In: Biometals, ISSN 0966-0844, E-ISSN 1572-8773, Vol. 19, no 3, p. 269-282Article in journal (Refereed)
    Abstract [en]

    Concentrations up to 2 and 12 nM of the hydroxamate siderophores ferrichrome and ferricrocin, respectively, were identified in soil solutions of podzolic forest soils at four sites in both northern and southern Sweden. No ferrichrysin was detected. As with the dissolved organic carbon and low molecular mass organic acids, the highest concentrations of the siderophores were found in the upper layers i.e. the mor layer, the eluvial and upper illuvial horizons. At the southern sites, the concentrations of ferrichrome and ferricrocin were both of similar magnitude and did not differ between the two sites. In contrast, soil solutions at the two northern sites contained more ferricrocin than ferrichrome; the ferricrocin concentrations were also higher at the northern sites than at the southern sites. Analyses were performed by high performance liquid chromatography with a porous graphitic carbon column on which ferrichrome, ferricrocin and ferrichrysin were separated. Detection by electrospray ionization mass spectrometry (ESI-MS) combined with on-line sample pre-concentration, by means of column-switching, enabled detection limits of 0.1-0.2 nM for ferrichrome, ferrichrysin and ferricrocin. The structural identities of the siderophores were further verified by MS/MS fragmentation. Fragmentation of ferrichrome, ferricrocin and ferrichrysin occured mainly via peptide cleavage. The most intense fragments were typified by the loss of one of the three iron(III) chelating hydroxamate residues, i.e N5-acyl-N5-hydroxy ornithine.

  • 112.
    Essén, Sofia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Johnson, Anna
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pedersen, Karsten
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Siderophore production by Pseudomonas stutzeri under aerobic and anaerobic conditions2007In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 73, no 18, p. 5857-5864Article in journal (Refereed)
  • 113.
    Fagerlund, Amelie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Shanks, David
    Sunnerheim, Kerstin
    Engman, Lars
    Frisell, Håkan
    Protective effects of synthetic and naturally occurring antioxidants in pulp products2003In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 18, p. 176-181Article in journal (Refereed)
    Abstract [en]

    Various types of natural and synthetic antioxidants when added to handsheets of pulp in low concentrations (0.2% weight%) could significantly reduce the emission of hexanal. The most efficient compounds caused a 90% reduction after eight weeks. Their capacity to inhibit brightness reversion was limited.

  • 114. Fagerlund, Amelie
    et al.
    Sunnerheim, Kerstin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Dimberg, Lena H
    Radical-scavenging and antioxidant activity of avenanthramides2009In: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 113, no 2, p. 550-556Article in journal (Refereed)
    Abstract [en]

    Avenanthramides are amides of cinnamoyl-anthranilic acids and, among cereals, are exclusively found in oats. This study investigated the structure-antioxidant activities of 15 avenanthramides with different substitution patterns in the two aromatic rings, seven of which were new avenanthramides synthesised and characterised in this study. Radical-scavenging activity was tested as reactivity towards 1,1-diphenyl-2-picrylhydrazyl (DPPH-). The activity increased with the number of radical-stabilising groups ortho to the phenolic hydroxy group. Both aromatic rings were independently important for activity, while conjugation across the amide bond was of minor importance. Antioxidant activity was determined as inhibition of linoleic acid oxidation. In contrast to the radical-scavenging activity, antioxidant activity was observed for most avenanthramides, and also for compounds with only one hydroxy group in either of the aromatic rings. Compared with alpha-tocopherol, the avenanthramides protected linoleic acid from oxidation to a smaller extent initially, but the effect lasted for a longer time.

  • 115.
    Fagerlund-Edfeldt, Amelie
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Naturally occurring phenols with antioxidant, antifungal and anti-browsing activity2014Doctoral thesis, comprehensive summary (Other academic)
  • 116.
    Fagerlund-Edfeldt, Amelie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effect of Debarking Water from Norway Spruce (Picea abies) on the Growth of Five Species of Wood-Decaying Fungi2014In: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 9-10, no 69c, p. 418-424Article in journal (Refereed)
    Abstract [en]

    Norway spruce (Picea abies) debarking water is an aqueous extract obtained as waste from the debarking of logs at paper mills. The debarking water contains a mixture of natural compounds that can exhibit diverse biological activities, potentially including fungicidal activity on some species of wood-decaying fungi. Thus, we investigated the growth rates of such fungi on agar plates to which debarking water extracts had been added. The experiment included five wood-decaying fungi, viz. Gloeophyllum sepiarium, Oligoporus lateritius, Ischnoderma benzoinum, Junghuhnia luteoalba, and Phlebia sp. Growth reduction was observed for all species at the highest tested concentrations of freeze-dried and ethanol-extracted debarking water, the ethyl acetate-soluble fraction and the diethyl ether-soluble fraction. However, the magnitude of the effect varied between different species and strains of individual species. The brown-rot fungi G. sepiarium and O. lateritius were generally the most sensitive species, with the growth of all tested strains being completely inhibited by the ethyl acetate-soluble fraction. These results indicate that development of antifungal wood-protecting agents from debarking water could potentially be a way to make use of a low-value industrial waste.

  • 117. Fazio, Valentina
    et al.
    Örtegren, Jonas
    Koelsch, Patrick
    Andersen, Audree
    Wantke, Dieter
    Möhwald, Helmut
    Motschmann, Hubert
    New insights in static and dynamic properties of soluble monolayers2003In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5223, p. 38-49Article in journal (Refereed)
    Abstract [en]

    Abstract In this paper we discuss selected equilibrium and dynamic properties of adsorp-tion layers of soluble surfactants. The surface state has been investigated by nonlinearoptical techniques based on second order χ(2)effects which exhibit a high surface specificityand suppress bulk contributions. The surface tension isotherm σ(c) of the homologousseries of n-alkyldimethylphosphine (n =8 − 12) can be described by Frumkin’s equation ofstate which yields the surface interaction parameter, surface coverage and the correspondingarea per molecule A. The comparison of the surface tension σ at a given area per moleculeA reveals a strong alternation within the homologous series. Odd C2n±1 layers show alower surface tension than the adjacent even members C2n of the homologous series. Thiseffect is also present at low surface coverage (A =1.4nm2) and cannot be attributed to adifferences in the chain-packing within a crystalline state. Infrared-Visible Sum-FrequencyGeneration Spectroscopy (SFGS) has been used to monitor the orientation and chain orderwithin the aliphatic tail. SFGS spectra have been recorded for different chain lengths andat different areas per molecule. The analysis of the spectra yields an order parameterG which is proportional to the number of gauche defects within the aliphatic tail. Theodd-even effect in the surface tension turned out to be accompanied by an odd-even effectin the order parameter G. The data suggest that an ordered structure has a bigger impacton the surface tension than an unordered structure. The odd-even effect is also observedin the orientation of the terminating methyl group as retrieved by polarization dependentSFGS measurements. The data shed some light in the relation between molecular andmacroscopic properties. Furthermore surface dilatational viscoelastic properties of afluorinated amphiphile have been measured by a novel version of the oscillating bubble.The oscillating bubble method generates a non-equilibrium state by a harmonic compressionand expansion of the surface layer formed at the tip of a capillary. The surface state ismonitored by Surface Second Harmonic Generation (SHG). This technique is highly surfacespecific and discriminates between monolayer and subsurface coverage. Our set-up allowsto measure the monolayer coverage under dynamic conditions and to relate this to surfacedilatational viscosity and elasticity. For a purely elastic surface layer the prediction of theLucassen van den Temple model (LvdT) are fulfilled.

  • 118.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Cellulose stabilizers for 2D materials inkjet inks2017Conference paper (Refereed)
    Abstract [en]

    To date, the most promising scalable method for achieving 2D materials dispersions is through liquidbasedexfoliation of nanosheets in solvents. We study the use of high throughput shear exfoliation insteadof sonication to exfoliate water dispersions of MoS2 using environmental friendly stabilizers based oncellulose. The resulted dispersion was then concentrated and inkjet printed on a flexible substrate. We usedethyl cellulose, cellulose nanofibers (CNF) and ultra-fine cellulose nanofibers (UF-CNF). The stability wasevaluated by measuring the differences in concentration over time. The particle size distribution (PSD) ofthe dispersed particles was evaluated using statistical methods applied to SEM images of the dispersions(See Fig 1 and 2). The zeta potential and the mechanisms of stabilization involved was evaluated (See Fig4). All three stabilizers appear to work very well for MoS2 nanosheets even though the mechanisms ofstabilization were different i.e. steric stabilization for MoS2-EC and electrostatic stabilization for MoS2-CNF and MoS2-UF-CNF dispersions. For the MoS2-EC dispersions we achieved a broader PSD (Fig. 1)and higher stability. Thin nanosheets was observed from the SEM image of MoS2-EC dispersions depositedonto cellulose filters by vacuum filtration (Fig. 5) which demonstrated that the exfoliation technique usedwas successful. The estimated concentration of the MoS2-EC dispersion after 8 days of sample preparationwas 0.24 mg/mL, 77% of the initial concentration (see Fig. 6) and it was relatively steady after 40 days ofsample preparation (0.22 mg/mL). To adjust the concentration and the viscosity of the MoS2-EC dispersion,we concentrated it using a rotary evaporator solvent exchange technique. For this we used terpineol andadjusted the viscosity using ethanol. This paper presents the results of an inkjet 2D material ink usingenvironmental friendly components different than previous 2D materials inks that used organic solvents orwater based dispersions containing surfactants.

  • 119.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Maslik, Jan
    Tomas Bata University.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Toivakka, Martti
    Åbo Akademi University.
    Koppolu, Rajesh
    Åbo Akademi University.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Printability of functional inkjet inks onto commercial inkjet substrates and a taylor made pigmented coated paper2018Conference paper (Other academic)
    Abstract [en]

    Printed electronics are of increasing interest. The substrates used have primarily been plastics although the interest for cellulose-based substrates is increasing due to the environmental aspect as well as cost. The requirements of substrates for electronically active inks differs from graphical inks and therefore we have investigated a custom-made pigment based coated paper and compared it to commercial photo-papers and a coated PE film.

    Our goal with the study of different substrates was to select the most suitable substrate to print water based 2D materials inkjet inks for flexible electronics.

    The discovery of graphene, a layered material achieved from the exfoliation of graphite, has resulted in the study of other materials with similar properties to cover areas where graphene could not be used due to the absence of a bandgap in the material. For example in thin film transistors (TFT) a semiconductor layer is essential to enable turn on and off the device. This semiconductor layer can be achieved using various materials but particular interest have been dedicated to abundant and cheap 2D materials such as the transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2). To date, most of the dispersions based on TMDs use organic solvents or water solutions of surfactants. Previously we focus on the study of environmental friendly inks produced by liquid phase exfoliation (LPE) of MoS2 in water using cellulose stabilizers such as ethyl cellulose (EC), cellulose nanofibrils (CNF) and nanofibrilcellulose (NFC). We have study various aspects of the ink fabrication includi  ng pH range, the source of MoS2, nanosheets thickness, particle size distribution,  ink stabilizers, ink concentration, viscosity and surface tension. These inks have very low concentration requiring a number of printing passes to cover the substrate. Therefore the substrate selection is crucial as a large amount of solvent is to be absorb by the substrate. Our goal was to use such an ink to print electrodes of MoS2 into a paper substrate after substrate selection.

    Commercial photo papers, a commercial coated PE film and a tailor made multilayer pigment coated paper substrate were used for the substrate selection analysis.  We print the substrates using a DIMATIX inkjet printer with a 10 pL printing head using the distillated water waveform supplied by the printer manufacturer. The voltage used was 23V and 4 nozzles were used for the print outs. The inkjet ink used was the organic PEDOT:PSS. We printed lines ranging from 1 pixel to 20 pixels with 1, 2 and 3 printing passes. The printing quality was evaluated through measurements of the waviness of the printed lines measured after imaging the printed samples with a SEM microscope. The line width measurement was done using the software from the SEM.

    We also evaluated the structure of the coatings using SEM and topography measurements. The ink penetration through the substrates was evaluated using Raman Spectroscopy. For the pigmented coated sample we measured 4% of ink penetration through the substrate for the 1pxl printed line printed once onto the paper.  Cross-section SEM images of the printed lines were made to visualize the ink penetration into the substrate.

    Regarding the electrical conductivity of the printed samples, the differences in resistivity varying the width of the printed lines and the number of printed passes were evaluated. The resistivity of the printed electrodes was evaluated using the 2-points probe method. Before the resistivity measurements, the printed substrates were heated at 50°C and 100°C for 30 minutes in an oven.

    We choose the PEDOT:PSS ink because it is a low price ink compared to metal nanoparticles inks for printed electronics. The print outs had low resistivity at a few printing passes with no need for sintering at high temperatures. The MoS2 ink has a very high resistance at a few printing passes due to lower coverage of the substrate therefore for this ink these measurements were not possible to be made. The main pigment composition of the paper coatings of the substrates was evaluated using FT-IR and EDX, these data plus the coating structure evaluated by SEM was related to the print quality.

    The best in test papers were used to print MoS2 electrodes. After the printing tests, another step for the optimization of the MoS2 ink properties shall be carried out in future studies for better print quality. We also evaluated the surface energy of the substrates through contact angle measurements to match the surface tension of the PEDOT:PSS ink and later the MoS2 ink. Although the pigmented coated printing substrate did not show better results than the commercial photo papers and PE foil in terms of line quality, it shows the lowest resistivity and sufficient results for low cost recyclable electronics, which do not require high conductivity. Nevertheless, the substrate was very thin and it could even be used in magazines as traditional lightweight coated papers (LWC) are used but with the additional of a printed electronic feature.

  • 120.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Green materials for inkjet printing of 2D materials and transparent electronics2018Conference paper (Other (popular science, discussion, etc.))
  • 121.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Liquid Exfoliation of Layered Materials in Water for Inkjet Printing2016In: Printing for Fabrication 2016: Materials, Applications, and Processes, USA: Curran Associates, Inc., 2016Conference paper (Refereed)
    Abstract [en]

    MoS2 is a layered material which is abundant and non-toxic and has been increasingly studied during the last few years as a semiconducting alternative to graphene. While most studies have been performed on single MoS2 nanosheets, for example to demonstrate high-performance electronic transistors, more work is needed to explore the use of MoS2 in printed electronics. The importance of using MoS2 as a printed electronic material could be understood by considering the several orders higher electron mobility in MoS2, even in several nanometer thick layers, compared to the organic and other materials used today. In the few studies performed so far on printing MoS2, the developed dispersions used mainly organic solvents that might be detrimental for the environment. Here, we show an environmentally friendly liquid-based exfoliation method in water where the solution was stabilized by sodium dodecyl sulfate (SDS) surfactant. The dispersions consisted of very thin MoS2 nanosheets with average lateral size of about 150 nm, surface tension of 28 mN m-1 and a shelf life of a year. Although both the concentration and viscosity was less than optimal, we were able to inkjet print the MoS2 solution on paper and on PET films, using multiple printing passes. By tuning the concentration/viscosity, this approach might lead to an environmentally friendly MoS2 ink suitable for printed electronics.

  • 122.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The Influence of pH on the Stability of Inks of Two-Dimensional Materials for Digital Fabrication2017Conference paper (Refereed)
    Abstract [en]

    We aim to achieve stable printable 2D inks with environmental friendly solvents using a surfactant as a stabilizer. This study focuses on the influence of the pH on the stability of the MoS2 dispersionsin acetic acid at concentrations ranging from pH 1 to 5.The effectiveness of liquid-based exfoliation using shear exfoliation was also evaluated though SEM images and resulted in very thin nanosheets. We observed that at pH concentrations higher than 2, the dispersions were more stable.

  • 123.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Towards flexible and cheap printed electronics using inks of exfoliated 2D materials stabilized by cellulose2017Conference paper (Other academic)
    Abstract [en]

    Flexible and cheap electronics are needed for simple applications such as sensors and solar cells. To achieve this, thin functional materials should be deposited efficiently to flexible substrates such as paper. A promising method for the deposition of such materials is through inkjet printing that said a stable and printable dispersion is necessary. We achieved this through liquid-based exfoliation of 2D materials in water using shear exfoliation and cellulose stabilizers. The resulted dispersion was then concentrated and inkjet printed on a flexible substrate. We used ethyl cellulose, cellulose nanofibers (CNF) and ultra-fine cellulose nanofibers (UF-CNF). All three stabilizers appear to work very well for MoS2 nanosheets even though the mechanisms of stabilization were different among them. For the MoS2-EC dispersions we achieved a broader PSD and higher dispersion stability. Thin nanosheets were observed from the SEM image of MoS2-EC dispersions deposited onto cellulose filters. The estimated concentration of the MoS2-EC dispersion after 20 days of sample preparation was 0.20 mg/mL. This dispersion was further processed to adjust the concentration and viscosity.  Good coverage of the substrate was achieved after 50 printing passes. If the same technique is applied to other 2D materials such as graphene (conductor) and boro nitride (insulator), a transistor can be fabricated.

  • 124.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Towards stable 2D materials inkjet inks: a study of stabilizers and MoS2 grades2017Conference paper (Refereed)
  • 125. Forsgard, N.
    et al.
    Sjöberg, P.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, M.
    Pettersson, J.
    Screening and identification of aluminium-containing biomolecules by column-switched LC-ICP-MS and LC-ESI-MS/MS2007In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 22, no 11, p. 1397-1402Article in journal (Refereed)
  • 126.
    Fredriksson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Efficient algorithms for highly automated evaluation of liquid chromatography - mass spectrometry data2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Liquid chromatography coupled to mass spectrometry (LC‐MS) has due to its superiorresolving capabilities become one of the most common analytical instruments fordetermining the constituents in an unknown sample. Each type of sample requires a specificset‐up of the instrument parameters, a procedure referred to as method development.During the requisite experiments, a huge amount of data is acquired which often need to bescrutinised in several different ways. This thesis elucidates data processing methods forhandling this type of data in an automated fashion.The properties of different commonly used digital filters were compared for LC‐MS datade‐noising, of which one was later selected as an essential data processing step during adeveloped peak detection step. Reconstructed data was further discriminated into clusterswith equal retention times into components by an adopted method. This enabled anunsupervised and accurate comparison and matching routine by which components fromthe same sample could be tracked during different chromatographic conditions.The results show that the characteristics of the noise have an impact on the performanceof the tested digital filters. Peak detection with the proposed method was robust to thetested noise and baseline variations but functioned optimally when the analytical peaks hada frequency band different from the uninformative parts of the signal. The algorithm couldeasily be tuned to handle adjacent peaks with lower resolution. It was possible to assignpeaks into components without typical rotational and intensity ambiguities associated tocommon curve resolution methods, which are an alternative approach. The underlyingfunctions for matching components between different experiments yielded satisfactoryresults. The methods have been tested on various experimental data with a high successrate.

  • 127.
    Fredriksson, Mattias
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wood Fibre Composites with High Fibre Content2005Report (Other academic)
  • 128.
    Fredriksson, Mattias
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Petersson, Patrik
    AstraZeneca.
    Axelsson, Bengt-Olof
    AstraZeneca.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    A component tracking algorithm for accelerated and improved liquid chromatography-mass spectrometry method development2010In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1217, no 52, p. 8195-8204Article in journal (Refereed)
    Abstract [en]

    A method for tracking of sample components during liquid chromatography–mass spectrometry (LC–MS) method development has been proposed. The method manages to, fully automatically and without user intervention, find the chromatographic peaks in the data sets, discriminate them to sample components and track them when the separation conditions have been changed. The algorithm utilises the resolution obtained from all considered data sets and has the ability to discriminate the non informative parts. The technique has a great sensitivity even in cases where a majority of the tracked components cannot easily be spotted by means of traditional total ion chromatogram (TIC) or base peak chromatogram (BPC) representations. The method was tested on an experimental sample using six different columns and an average of 79% of the suggested sample components could be successfully tracked at a minimum area of 0.05% of the main component in the sample. 66 components with 79–92% of the total suggested component area were able to be tracked between all data sets. The method could be used to rapidly investigate selectivity during different types of separation conditions.

  • 129.
    Fredriksson, Mattias
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Petersson, Patrik
    Jörntén-Karlsson, Magnus
    Axelsson, Bengt-Olof
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    An objective comparison of pre-processing methods for enhancement of liquid chromatography-mass spectrometry data2007In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1172, no 2, p. 135-150Article in journal (Refereed)
    Abstract [en]

    Four data pre-processing methods have been applied with different settings to data sets obtained from the analysis of a pharmaceutical drug and its degradation products by liquid chromatography�mass spectrometry (LC�MS). The methods compared were the frequently used component detection algorithm (CODA) and three kinds of digital filters�matched filtration (MF), Gaussian second derivative (GSD) and Savitzky�Golay. The aim was to evaluate the performance and robustness of these methods for extracted ion chromatogram (XIC), total ion chromatogram (TIC) and base peak chromatogram (BPC) in the presence of different types of noise. In accordance with theory, the best improvements in signal-to-noise ratio (S/N) of the XICs were obtained with MF under the ideal case with random white noise. However, when highly coloured noise was present, it was found that no improvements in XIC S/N could be obtained with any of the pre-processing methods studied. GSD and CODA did, however, improve the S/N for both TIC and BPC. GSD and CODA also significantly reduced the background in the spectral domain, thereby facilitating the interpretation of the mass spectra. Another advantage associated with CODA and to some extent also with GSD is their data reduction ability.

  • 130. Fronza, G.
    et al.
    Fuganti, C.
    Pedrocchi-Fantoni, G.
    Högberg, Hans-Erik
    Servi, S.
    Chiral Alpha-Methyl-homoallylic alcohols from Yeast-generated Precursors: Synthesis of (4S,5R)-Sitophilure1988In: Chemistry Letters, ISSN 0366-7022, Vol. 1988, no 3, p. 385-388Article in journal (Refereed)
  • 131. Fuganti, C
    et al.
    Grasselli, P
    Servi, S
    Högberg, Hans-Erik
    Bakers Yeast Mediated Preparation of (S)-3-(2-Furyl)- 2-methyl-1-propanol a Bifunctional Chiral C5 Isoprenoid Synton. Synthesis of (4R,8R)-4,8-Dimethyldecanal, Pheromone of Tribolium castaneum.1988In: Journal of the Chemical Society. Perkin Transactions I, ISSN 0300-922X, Vol. 1988, no 12, p. 3061-3065Article in journal (Refereed)
  • 132. Fuganti, C.
    et al.
    Grasselli, P.
    Servi, S.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fermenting Bakers' yeast reduction of a-methyl-b-(2-furyl)acrolein1992-1997In: Preparative biotransformations: whole cell and isolated enzymes in organic systems, 1992-1997, p. 1-7Chapter in book (Other scientific)
  • 133.
    Geibe, Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects on soil solution chemistry caused by sampling method, soil treatment and vegetation2005Licentiate thesis, comprehensive summary (Other academic)
  • 134.
    Geibe, Christine
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Danielsson, Rolf
    Uppsala University.
    van Hees, Patrick A.W
    Örebro University.
    Lundström, Ulla. S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Comparison of soil solution chemistry sampled by centrifugation, two types of suction lysimeters and zero-tension lysimeters2006In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 21, no 12, p. 2096-2111Article in journal (Refereed)
    Abstract [en]

    The choice of sampling method for soil solution is of great importance. In this paper soil solution chemistry sampled by centrifugation, two types of suction lysimeters and zero-tension lysimeters have been studied with the purpose of investigating systematic differences between them. The samples were taken at 4 depths from an acidified forest soil as well as from adjacent lime and ash treated soils. A centrifugation drainage method was compared with two types of suction lysimeters (‘Rhizon’ and ‘Prenart’) and zero-tension lysimeters. About half of the 27 variables measured showed a significant difference between the sampling methods used. Typically the centrifuged samples had lower pH (4.0 vs. 4.4), Ca (21 lM vs. 30 lM) and Mg (25 lM vs. 34 lM) concentrations and higher Cl (330 lM vs. 230 lM) and DOC (4.4 mM vs. 3.2 mM) concentrations than the Rhizon lysimeters. Also the other lysimeters showed significant differences compared to the centrifuged samples for about half the number of analytes. Centrifuged samples had higher concentrations of all analytes except NO3 and PO4 compared to zero-tension lysimeters and also for all analytes except NO3 and Al compared to Prenart lysimeters. Among the environmental factors considered depth showed an influence to some extent, while sampling occasion had a great significant impact on the difference between the centrifugation method and the Rhizon lysimeters. Factors like individual pits or soil treatment did not show any influence on the difference between the methods.

  • 135.
    Geibe, Christine E
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara J. M
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    van Hees, Patrick A. W
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Impact of lime and ash applications on soil solution chemistry of acidified podzolic soils.2003In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 3, no 4, p. 77-96Article in journal (Refereed)
    Abstract [en]

    Soil solution samples were taken from two sites (Horröd and Hasslöv) in the south part of Sweden to evaluate how soil solution chemistry responded to different treatmentswith dolomite and wood ash. At Horröd, samples were taken four years after application of wood ash, 4.28 ton ha-1 and dolomite, 3.25 ton ha-1. At Hasslöv dolomite, 3.45 ton ha-1 and 8.75 ton ha-1 was applied and samples were taken 15 yr later. It was found that treatment with dolomite at one site (Hasslöv) resulted in higher pH values (<2 pH units) and higher nitrification. It was also found at this site that the total Al and the inorganic Al concentrations decreased with dolomite treatment. The Ca, Mg, DOC, Fe, SO4 2- and Cl- concentrations, mainly in the topsoil, were found to be higher at both sites, following dolomite treatment; Ca and Mg concentrations were 2–8 times higher (<820 mgrM) than in controls (<70 mgrM). Wood ash was found to have less impact. The PO4 concentration in the O2 horizon at Hasslöv decreased due to dolomite-treatment. ANOVA (Analyse of Variance) and PLS (Partial Least Square) were used to evaluate the data from the two sites.

  • 136. Giesler, R.
    et al.
    Ilvesniemi, H.
    Nyberg, L.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Bishop, K.
    Kareinen, T.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Distribution and mobilization of Al, Fe and Si in three podzolic soil profiles in relation to the humus layer.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 249-263Article in journal (Refereed)
    Abstract [en]

    The mobilization of Al, Fe and Si in podzols is often associated with the weathering of silicate minerals in the E horizon, downward migration, and their accumulation lower in the soil profile. This study investigated Al, Fe, and Si concentrations in soil water (centrifugation samples) and estimated leaching losses from the humus layer in comparison with those in the mineral E and B horizon. Concentrations of total soluble Al and Fe in soil water were higher in the O and E horizons than in B horizon samples, but not significantly different between the two uppermost horizons. Si concentrations were higher in the E than in the O horizon. The amount of Al and Fe leaching from the E horizon (i.e. input to the B horizon) compared to amount leaching from the O horizon (i.e. the input to the E horizon) ranged from 92% to 163%. Calculated leaching losses from the lower B horizon were less than 3% of the input to the B horizon. The results suggest that a large part of the illuviated Al and Fe in the Bs horizon is derived from the O horizon. Similar values for the Si ranged from 56% to 61% (comparing E horizon output with E horizon input). Budget estimates available for one of the investigated podzols indicated that biocycling via above-ground litter explained < 12% of the estimated annual input of Al and Fe to the forest floor. Inputs of Al and Fe due to upward flow of capillary water accounted for about 26% of the Al and Fe in the O layer. The results show that there is a considerable pool of Si Al, Fe in the humus layer. This pool plays an important part in the present day biogeochemical cycling of these elements in podzolic soils. Several mechanisms possibly involved in the transfer of Al, Fe and Si from the mineral soil to the humus layer are discussed.

  • 137. Gustafsson, Jon Petter
    et al.
    van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, Michael
    Karltun, Erik
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Partitioning of base cations and sulphate between solid and dissolved phases in three podzolized forest soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 311-333Article in journal (Refereed)
    Abstract [en]

    The cation and SO4 adsorption properties of O and B horizons of three podzolised soils in Sweden and Finland were studied through analysing the soil solution at six different sampling occasions and through a set of batch experiments. High concentrations of dissolved organic carbon and cations were found in centrifuged soil solutions from the O horizon, especially during autumn. An analysis using the WHAM-S model suggested that most of the dissolved Ca, Mg, K and Mn were counter-ions, residing in the diffuse layers of dissolved fulvic acids. Hence, the solubility of these cations depended on the solubility of organic matter. Model exercises suggested that the solubility of humics in turn was influenced by seasonal differences in hydrophobicity and by the water content. Furthermore, the model results showed that only a low proportion of the B horizon organic matter was involved in calcium binding. This is probably due to the interaction between organic matter and oxide surfaces in this horizon. In the case of sulphate adsorption in the B horizons, a surface complexation model was tested for its ability to describe batch experiment data and temporal differences in soil water chemistry. This model was based on the diffuse-layer model and it was optimised by adjusting the surface site concentration and the point of zero charge. However, the interaction between Ca2+ and SO4/2- could not be modelled. Comparisons between the model and the field observations proved to be difficult due to a considerable soil heterogeneity. (C) 2000 Elsevier Science B.V.

  • 138.
    Hagström, Å.K.
    et al.
    Pheromone group, Department of Biology, Lund University, Lund, Sweden.
    Liénard, M
    Pheromone group, Department of Biology, Lund University, Lund, Sweden.
    Groot, A
    Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Löfstedt, C
    Pheromone group, Department of Biology, Lund University, Lund, Sweden.
    Semi-selective fatty acyl reductases from four heliothine moths influence the specific pheromone composition2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 5, p. Art. no. e37230-Article in journal (Refereed)
    Abstract [en]

    Background: Sex pheromones are essential in moth mate communication. Information on pheromone biosynthetic genes and enzymes is needed to comprehend the mechanisms that contribute to specificity of pheromone signals. Most heliothine moths use sex pheromones with (Z)-11-hexadecenal as the major component in combination with minor fatty aldehydes and alcohols. In this study we focus on four closely related species, Heliothis virescens, Heliothis subflexa, Helicoverpa armigera and Helicoverpa assulta, which use (Z)-11-hexadecenal, (Z)-9-tetradecanal, and (Z)-9-hexadecenal in different ratios in their pheromone blend. The components are produced from saturated fatty acid precursors by desaturation, β-oxidation, reduction and oxidation. Results: We analyzed the composition of fatty acyl pheromone precursors and correlated it to the pheromone composition. Next, we investigated whether the downstream fatty-acyl reduction step modulates the ratio of alcohol intermediates before the final oxidation step. By isolating and functionally characterizing the Fatty Acyl Reductase (pgFAR) from each species we found that the pgFARs were active on a broad set of C8 to C16 fatty acyl substrates including the key pheromone precursors, Z9-14, Z9-16 and Z11-16:acyls. When presenting the three precursors in equal ratios to yeast cultures expressing any of the four pgFARs, all reduced (Z)-9-tetradecenoate preferentially over (Z)-11-hexadecenoate, and the latter over (Z)-9-hexadecenoate. Finally, when manipulating the precursor ratios in vitro, we found that the pgFARs display small differences in the biochemical activity on various substrates. Conclusions: We conclude that a pgFAR with broad specificity is involved in heliothine moth pheromone biosynthesis, functioning as a semi-selective funnel that produces species-specific alcohol product ratios depending on the fatty-acyl precursor ratio in the pheromone gland. This study further supports the key role of these in pheromone biosynthesis and emphasizes the interplay between the pheromone fatty acyl precursors and the Lepidoptera specific pgFARs in shaping the pheromone composition. © 2012 Hagström et al.

  • 139. Hansson, B. S.
    et al.
    van der Pers, J. N. C.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sex Pheromone Perception in male pine sawflies, Neodiprion sertifer (Hymenoptera; Diprionidae)1991In: Journal of Comparative Physiology A, ISSN 0340-7594, Vol. 168, no 5, p. 533-538Article in journal (Refereed)
  • 140.
    Harvey, Deborah J.
    et al.
    Royal Holloway University of London, UK.
    Harvey, Hannah
    Royal Holloway University of London, UK.
    Harvey, Rachael P.
    UCL, London, England.
    Kadej, Marcin
    Univ Wroclaw, Poland.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Gange, Alan C.
    Royal Holloway University of London, UK.
    Finch, Paul
    Royal Holloway University of London, UK.
    Use of novel attraction compounds increases monitoring success of a rare beetle, Elater ferrugineus2017In: Insect Conservation and Diversity, ISSN 1752-458X, E-ISSN 1752-4598, Vol. 10, no 2, p. 161-170Article in journal (Refereed)
    Abstract [en]

    The use of pheromones to determine distributions of rare saproxylic insects is an increasingly popular technique. Pheromones may, however, also be used to elucidate the biology of these cryptic species, a vital requirement if they are to be accurately monitored and conserved. We used non-invasive aerial trapping to compare the effectiveness of chemicals produced by Elater ferrugineus L (Coleoptera: Elateridae), namely 7-methyloctyl (Z)-4-decenoate (the female-produced sex pheromone), and male compounds (geranyl and neryl acetone and 6-methyl-5-heptene-2-one). The male compounds were identified using headspace analysis by solid phase micro-extraction gas chromatography-mass spectrometry. We discovered that males only produce these two compounds after having been attracted to a female, and that this serves to attract further males to a female. Such compounds do not appear to attract females but for a species that has a short activity period and is non-feeding in the adult stage, may ensure breeding success when populations are low. By marking all beetles caught, we were able to demonstrate that recapture rate using this method is low (approximately 11% of total captures annually). Therefore, the method does not limit dispersal or breeding opportunities, making it a valuable tool for monitoring endangered saproxylic beetle species.

  • 141. Haslinger, E.
    et al.
    Ottner, F.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pedogenesis in the Alno carbonatite complex, Sweden2007In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 142, no 1-2, p. 127-135Article in journal (Refereed)
  • 142.
    Hedenstedt, Kristoffer
    et al.
    Göteborgs Universitet; AkzoNobel.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Göteborgs Universitet.
    Ahlberg, Elisabet
    Göteborgs Universitet.
    In-Situ Raman Spectroscopy of α- and γ-FeOOH during Cathodic Load2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 9, p. H621-H627Article in journal (Refereed)
    Abstract [en]

    Water reduction on corroded iron surfaces is technologically and fundamentally important. Here, the technological interest originatesfrom the chlorate process where water reduction is the main cathodic process. Fundamentally, water reduction on oxide surfaces raisesquestions on the stability of the oxide and the nature of electrocatalytic surface sites. Two iron oxyhydroxides,α-andγ-FeOOH,were electrodeposited on titanium substrate and their reduction processes were followed in detail with in-situ Raman spectroscopy,using low incident laser power to avoid sample damaging. Polarization to negative potentials show two reduction peaks forγ-FeOOHand one peak forα-FeOOH prior to hydrogen evolution. The characteristic Raman peaks gradually disappear as the potential ismade more negative but no new peaks can be observed.δ-FeOOH was detected as an intermediate phase upon oxidation of thereduced surface layer. This indicates that Fe(OH)2is formed during cathodic polarization and initially re-oxidized to the isostructuralδ-FeOOH. Characteristic Raman signals of the original phases appear upon further oxidation in air.

  • 143.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Fredrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Syntheses of female sex pheromone precursors of pine sawflies species and of some structurally related methyl-branched long-chain 2-alkanols2002In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 28, no 6, p. 1237-1254Article in journal (Refereed)
    Abstract [en]

    3,7-Dimethyl-2-undecanol, 3,7,9-trimethyl-2-tridecanol, and 3,7, 11-trimethyl-2-tridecanol were synthesized as racemic mixtures in moderate yields. The alcohols are known precursors of the female sex pheromones of the pine sawfly species Diprion nipponica, Macrodiprion nemoralis, and Microdiprion pallipes, respectively. Stereoisomeric mixtures of 3,8,12-trimethyl-2-tridecanol, erythro-(2R,3R,11R/S)-3,11-dimethyl-2-tetradecanol, 3,5-dimethyl-2-tetradecanol, and 5,7-dimethyl-2-tetradecanol, structurally related to sex pheromone alcohol precursors of pine sawfly species, were also synthesized in moderate yields. The key reaction in the syntheses was the ring opening of γ-butyrolactones by using different alkyl lithiums as nucleophiles.

  • 144.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Fredrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hjalmarsson, Mats
    Synthesis of N-propionylated (S)-(-)-2-(pyrrolidin-2-yl)propan-2-ol and its use as a chiral auxiliary and selectivity marker in asymmetric aldol reactions2000In: Journal of the Chemical Society. Perkin Transactions 1, ISSN 1472-7781, Vol. 2000, p. 1513-1518Article in journal (Refereed)
    Abstract [en]

    The N-propionylated pyrrolidine derivative and chiral auxiliary, (S)-(-)-2-(pyrrolidin-2-yl)propan-2-ol, was synthesised and used in stereoselective aldol reactions with benzaldehyde. Differences in stereoselectivity were investigated as a function of temperature, solvent, chelating agent and the amount of the chelating agent used by monitoring the 1H NMR spectra of the aldol adducts that were obtained. Among the additives that were investigated, Cp2ZrCl2 induced higher syn-selectivity, while SnCl2 induced higher syn-selectivity respectively. TMSCl was found to induce high selectivity for one syn- and one anti-diastereomer. Varying the ligand sets on titanium additives was found to induce differences in selectivity, with (i-PrO)3TiCl exhibiting syn-selectivity and Cp2TiCl2 exhibiting anti-selectivity. Differences in reactivity and stereoselectivity were also found to depend upon the amount of Lewis acid that was added. Methods for removal of the auxiliary were also investigated. Acidic hydrolysis was used successfully to obtain the desired 3-hydroxy-2-methyl-3-phenylpropionic acids, but was found to give low yields and resulted in a large amount of epimerisation. Furthermore, the ethyl esters of these hydroxy acids are easy to separate into pure syn- and anti-diastereomers by LC. © The Royal Society of Chemistry 2000.

  • 145.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Helen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lund, Susan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Stereoselective esterification of 2,6-dimethyl-1,7-heptanedioic acid, catalysed by Candida rugosa lipase2003In: Journal of Molecular Catalysis B: Enzymatic, ISSN 1381-1177, E-ISSN 1873-3158, Vol. 23, no 1, p. 53-59Article in journal (Refereed)
    Abstract [en]

    The immobilised Candida rugosa lipase (CRL) displayed S-preference for both stereogenic centres in this sequential esterification of 2,6-dimethyl-1,7-heptanedioic acid (1) (pure meso and meso: (+/-) mixture, 53/47) with n-butanol in cyclohexane at a(w) = 0.8. The reaction was faster when short-chain primary n-alcohols was used and very slow, or even none reactive, when a Ion-chain alcohol was used.

  • 146.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Helen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lund, Susan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Abersten, M.
    Persson, D.
    Synthesis and lipase catalysed stereoselective acylation of some 3-methyl-2-alkanols, identified as sex pheromone precursors in females of pine sawfly species2002In: Journal of The Chemical Society, Perkin Transactions 1, ISSN 1472-7781, Vol. 2002, no 15, p. 1810-1817Article in journal (Refereed)
    Abstract [en]

    Several 3-methylalkan-2-ols precursors to sex pheromones of Diprion pini, Gilpinia pallida, Gilpinia frutetorum, Diprion nipponica, Macrodiprion nemoralis and Microdiprion pallipes were synthesised as stereoisomeric mixtures in moderate to good yields. The key reaction sequence in the syntheses was the ring opening of either cis- or racemic trans-epoxybutane using a higher order cyanocuprate as nucleophile followed by a highly efficient lipase catalysed stereoselective acylation of the obtained 3-methylalkan-2-ol. The biologically active species specific stereoisomer was synthesised as a single stereoisomer in high stereoisomeric purity, as one in a mixture of two or as one of four stereoisomers when the appropriate 3-methylalkan-2-ol was stereoselectively acylated using a Pseudomonas sp. lipase as catalyst.

  • 147.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Edlund, Helene
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Wassgren, Ann-Britt
    Bergström, Gunnar
    Anderbrant, Olle
    Östrand, Fredrik
    Sierpinski, Andrzej
    Auger-Rozenberg, Marie-Anne
    Herz, Annette
    Heitland, Werner
    Varama, Martti
    The Sex Pheromones of Two Pine Sawfly Species, Gilpinia frutetorum and Gilpinia socia: Chemical Identification, Synthesis and Biological Activity2009In: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 64, no 9-10, p. 733-742Article in journal (Refereed)
    Abstract [en]

    3,7-Dimethylpentadecan-2-ol and 3-methylpentadecan-2-ol were identified in female whole body extracts from the two pine sawfly species Gilpinia frutetorum and Gilpinia socia. This is the first observation of 3-methylpentadecan-2-ol in extracts of a female pine sawfly species. Synthetic and highly pure stereoisomers of 3,7-dimethylpentadecan-2-ol and 3-methylpentadecan-2-ol were used to verify that the (2S,3R,7R)-isomer of 3,7-dimethyl- pentadecan-2-ol and (2S,3R)-3-methylpentadecan-2-ol were present in the extracts. The four stereoisomers of 3-methylpentadecan-2-ol and their biologically active esters were produced via chemoenzymatic methods and the synthesis is described in detail. Male G. socia anten- nae responded strongly in EAG recordings to the (2S,3R)-isomer of the acetate and propionate of 3-methylpentadecan-2-ol. Male antennae of both G. frutetorum and G. socia also responded to the (2S,3R,7R)- and (2S,3R,7S)-acetates of 3,7-dimethylpentadecan-2-ol.

  • 148.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Helene
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wassgren, Ann-Britt
    Göteborg University.
    Bergström, Gunnar
    Göteborg University.
    Anderbrant, Olle
    Lund University.
    Östrand, Fredrik
    Lund University.
    Sierpinski, Andrzej
    Forest Research Institute, Poland.
    Auger-Rozenberg, Marie-Anne
    Institut National de la Recherche Agronomique, France.
    Herz, Marie-Anne
    Technische Universität München, Germany.
    Heitland, Werner
    Technische Universität München, Germany.
    Varama, Martti
    Finnish Forest Research Institute, Finland.
    Sex pheromone of the pine sawfly, Gilpinia pallida: Chemical identification, synthesis, and biological activity2006In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 32, no 11, p. 2525-2541Article in journal (Refereed)
    Abstract [en]

    We present the identification of the sex pheromone in the pine sawfly, Gilpinia pallida, including analysis of the female pheromone content, male antennal response and attraction in the field, and synthesis of the most active pheromone component. Several 3,7-dimethyl-2-alkanols were identified from female whole-body extracts, including some compounds with a 2R configuration. This is the first observation of such compounds in a pine sawfly species. Antennae of male G. pallida responded strongly in electroantennograph (EAG) recordings to the (2S,3R,7R)-isomers of the propionates of 3,7-dimethyl-2-tridecanol, 3,7-dimethyl-2-tetradecanol, and 3,7-dimethyl-2-pentadecanol, as well as to the acetates of the tri- and pentadecanols (the acetate of the tetradecanol was not tested). The propionate of (2S,3R,7R)-3,7-dimethyl-2-tetradecanol caught more males in the field than the corresponding isomer of tri- or pentadecanol. We suggest that the (2S,3R,7R)-isomer of 3,7-dimethyl-2-tetradecanol is likely the main sex pheromone precursor in G. pallida, with a subsidiary role for the (2S,3R,7R)-isomer of the tridecanol. Preparation of highly pure (2R,3R,7R)- and (2S,3R,7R)-stereoisomers of 3,7-dimethyl-2-tetradecanol, including the biological active esters, was performed via chemoenzymatic methods and is described in detail.

  • 149.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Efficient Opening of trans-2,3-Epoxybutane by a Higher Order Cuprate: Synthesis of erythro-3.7-Dimethylpentadecan-2-yl Acetate, Pheromone of Pine Sawflies1994In: Tetrahedron, ISSN 0040-4020, Vol. 50, no 17, p. 5225-5232Article in journal (Refereed)
  • 150.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Anderbrant, Olle
    Wang, H.B.
    Zhang, Z.
    Chen, G.F.
    Sex pheromone for monitoring flight periods and population densities of the pine sawfly, Diprion jingyuanensis Xiao et Zhang (Hym.: Diprionidae)2010In: Forests for the Future - Sustaining Society and the Environment: Abstracts / [ed] John A Parrotta and Mary A Carr, 2010, Vol. 12, no 5, p. 369-369Conference paper (Refereed)
1234567 101 - 150 of 446
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