Endre søk
Begrens søket
45678910 301 - 350 of 488
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 301.
    Löfstedt, Håkan
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Westerlund, Jessica
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Graff, Pål
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Bryngelsson, Ing-Liss
    Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Mölleby, Göte
    Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Olin, Anna-Carin
    Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
    Eriksson, Kåre
    Umeå University, Umeå, Sweden.
    Westberg, Håkan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Respiratory and ocular symptoms among employees at Swedish indoor swimming poolsManuskript (preprint) (Annet vitenskapelig)
  • 302.
    Lönnberg, Hanna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Ytbehandlingsteknik.
    Ring-opening polymerization from cellulose for biocomposite applications2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    There is an emerging interest in the development of sustainable materials with high performance. Cellulose is promising in this regard as it is a renewablere source with high specific properties, which can be utilized as strong reinforcements in novel biocomposites. However, to fully exploit the potential ofcellulose, its inherent hydrophilic character has to be modified in order toimprove the compatibility and interfacial adhesion with the more hydrophobicpolymer matrices commonly used in composites.In this study, the grafting of poly(ε-caprolactone) (PCL) and poly(L-lactide)(PLLA) from cellulose surfaces, via ring-opening polymerization (ROP) of ε-caprolactone and L-lactide, was investigated. Both macroscopic and nano-sizedcellulose were explored, such as filter paper, microfibrillated cellulose (MFC),MFC-films, and regenerated cellulose spheres. It was found that thehydrophobicity of the cellulose surfaces increased with longer graft lengths, andthat polymer grafting rendered a smoother surface morphology.To improve the grafting efficiency in the ROP from filter paper, both covalent(bis(methylol)propionic acid, bis-MPA) and physical pretreatment (xyloglucanbisMPA)were explored. The highest grafting efficiency was obtained with ROPfrom the bis-MPA modified filter papers, which significantly increased amountof polymer on the surface, i.e. the thickness of the grafted polymer layer.MFC was grafted with PCL to different molecular weights. The dispersability innon-polar solvent was obviously improved for the PCL grafted MFC, incomparison to neat MFC, and the stability of the MFC suspensions was better maintained with longer grafts. PCL based biocomposites were prepared from neat MFC and PCL grafted MFCwith different graft lengths. The polymer grafting improved the mechanical properties of the composites, and the best reinforcing effect was obtained when PCL grafted MFC with the longest grafts were used as reinforcement.A bilayer laminate consisting of PCL and MFC-films grafted with different PCL graft lengths displayed a gradual increase in the interfacial adhesion with increasing graft length.The effect of grafting on the adhesion was also investigated via colloidal probeatomic force microscopy at different temperatures and time in contact. A significant improvement in the adhesion was observed after polymer grafting.

  • 303. Maddalo, Gianluca
    et al.
    Shariatgorji, Mohammadreza
    Adams, Christopher M.
    Fung, Eva
    Nilsson, Ulrika
    Zubarev, Roman A.
    Sedzik, Jan
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Teknisk strömningslära.
    Ilag, Leopold L.
    Porcine P2 myelin protein primary structure and bound fatty acids determined by mass spectrometry (vol 397, pg 1903, 2010)2010Inngår i: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 398, nr 7-8, s. 3225-3226Artikkel i tidsskrift (Fagfellevurdert)
  • 304.
    Maicher, André
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Gazy, Inbal
    Sharma, Sushma
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Marjavaara, Lisette
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Grinberg, Gilad
    Shemesh, Keren
    Chabes, Andrei
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik. Umeå universitet, Medicinska fakulteten, Molekylär Infektionsmedicin, Sverige (MIMS).
    Kupiec, Martin
    Rnr1, but not Rnr3, facilitates the sustained telomerase-dependent elongation of telomeres2017Inngår i: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 13, nr 10, artikkel-id e1007082Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ribonucleotide reductase (RNR) provides the precursors for the generation of dNTPs, which are required for DNA synthesis and repair. Here, we investigated the function of the major RNR subunits Rnr1 and Rnr3 in telomere elongation in budding yeast. We show that Rnr1 is essential for the sustained elongation of short telomeres by telomerase. In the absence of Rnr1, cells harbor very short, but functional, telomeres, which cannot become elongated by increased telomerase activity or by tethering of telomerase to telomeres. Furthermore, we demonstrate that Rnr1 function is critical to prevent an early onset of replicative senescence and premature survivor formation in telomerase-negative cells but dispensable for telomere elongation by Homology-Directed-Repair. Our results suggest that telomerase has a "basal activity" mode that is sufficient to compensate for the "end-replication-problem" and does not require the presence of Rnr1 and a different "sustained activity" mode necessary for the elongation of short telomeres, which requires an upregulation of dNTP levels and dGTP ratios specifically through Rnr1 function. By analyzing telomere length and dNTP levels in different mutants showing changes in RNR complex composition and activity we provide evidence that the Mec1ATR checkpoint protein promotes telomere elongation by increasing both dNTP levels and dGTP ratios through Rnr1 upregulation in a mechanism that cannot be replaced by its homolog Rnr3.

  • 305.
    Malmström, David
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Pelzing, Matthias
    Bruker Bioscience Melbourne, Australia.
    Capillary Electrophoresis-Mass Spectrometry (CZE-MS) Analysis of Intact Monoclonal Antibodies using bare fused silicaManuskript (preprint) (Annet vitenskapelig)
  • 306.
    Mardoukhi, Sahar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Kartläggning av inkomna konsumentfrågor om läkemedel och biverkningar till Läkemedelsupplysningen på Läkemedelsverket2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Kartläggning av inkomna konsumentfrågor om läkemedel och biverkningar till Läkemedelsupplysningen på Läkemedelsverket

    Sahar Mardoukhi

    Handledare: Elin Kimland, Med Dr, Leg ssk, farmaceut. Examinator: Professor Margareta Hammarlund-Udenaes

    Institutionen för farmaceutisk biovetenskap. Avdelningen för farmakokinetik och läkemedelsterapi. 30 hp

     

    Introduktion: Läkemedel är ett viktigt verktyg för att behandla patienter men kan ibland ge upphov till läkemedelsbiverkningar. Under de senaste decennierna har myndigheter ansträngt sig för att kunna bidra till en säkrare läkemedelsanvändning för konsumenter genom att bl. a. etablera möjlighet till  rapportering av biverkningar för konsumenter. Ett annat initiativ är att det finns en Läkemedelsupplysningen (LMU) inom Sverige som besvarar frågor om läkemedel och läkemedelsnära produkter som riktar sig till allmänheten.

    Syfte: Denna studie syftar till att öka kunskapen om konsumenternas frågor om läkemedelsbiverkningar genom att kartlägga och analysera inkomna frågor till LMU.

    Material och metoder: Retrospektiv epidemiologisk kartläggning av inkomna frågor om läkemedelsbiverkningar till LMU baserad på mätning under en vecka per kvartal januari till juni 2013. En statistisk analys med χ2-test (P-värde <0,05) utfördes för att studera eventuella skillnader mellan de två utvalda kvartalsperioder.

    Resultat: Totalt dokumenterades 968 frågor i undersökningen varav 513 frågor från första kvartalsperioden och 455 frågor från andra kvartalsperioden. Drygt en tredje del (38%) av frågorna berörde ATC-kod N (läkemedel för behandling av sjukdomar, symtom från nervsystemet). Omkring 5 % av frågor gällande biverkningar som inte var tidigare dokumenterade i produktinformationen. Ingen signifikant skillnad observerades för de olika kategorier mellan de två kvartalsperioderna dock observerades en signifikant skillnad för antalet biverkningsfrågor mellan båda kvartalsperioderna.

    Konklusion: Kartläggning av inkomna konsumentfrågor om läkemedelsbiverkningar kan utgöra en källa för ökad kunskap utifrån ett konsumentperspektiv. Majoriteten av frågorna handlade om läkemedlen som ofta förskrivs och är väldokumenterade. Andelen frågor om ej tidigare listade biverkningar var låg.

  • 307. McDonald, Karin R.
    et al.
    Guise, Amanda J.
    Pourbozorgi-Langroudi, Parham
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Cristea, Ileana M.
    Zakian, Virginia A.
    Capra, John A.
    Sabouri, Nasim
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Pfh1 Is an Accessory Replicative Helicase that Interacts with the Replisome to Facilitate Fork Progression and Preserve Genome Integrity2016Inngår i: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 12, nr 9, artikkel-id e1006238Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Replicative DNA helicases expose the two strands of the double helix to the replication apparatus, but accessory helicases are often needed to help forks move past naturally occurring hard-to-replicate sites, such as tightly bound proteins, RNA/DNA hybrids, and DNA secondary structures. Although the Schizosaccharomyces pombe 5'-to-3' DNA helicase Pfh1 is known to promote fork progression, its genomic targets, dynamics, and mechanisms of action are largely unknown. Here we address these questions by integrating genome-wide identification of Pfh1 binding sites, comprehensive analysis of the effects of Pfh1 depletion on replication and DNA damage, and proteomic analysis of Pfh1 interaction partners by immunoaffinity purification mass spectrometry. Of the 621 high confidence Pfh1-binding sites in wild type cells, about 40% were sites of fork slowing (as marked by high DNA polymerase occupancy) and/or DNA damage (as marked by high levels of phosphorylated H2A). The replication and integrity of tRNA and 5S rRNA genes, highly transcribed RNA polymerase II genes, and nucleosome depleted regions were particularly Pfh1-dependent. The association of Pfh1 with genomic integrity at highly transcribed genes was S phase dependent, and thus unlikely to be an artifact of high transcription rates. Although Pfh1 affected replication and suppressed DNA damage at discrete sites throughout the genome, Pfh1 and the replicative DNA polymerase bound to similar extents to both Pfh1-dependent and independent sites, suggesting that Pfh1 is proximal to the replication machinery during S phase. Consistent with this interpretation, Pfh1 co-purified with many key replisome components, including the hexameric MCM helicase, replicative DNA polymerases, RPA, and the processivity clamp PCNA in an S phase dependent manner. Thus, we conclude that Pfh1 is an accessory DNA helicase that interacts with the replisome and promotes replication and suppresses DNA damage at hard-to-replicate sites. These data provide insight into mechanisms by which this evolutionarily conserved helicase helps preserve genome integrity.

  • 308. McDonald, Karin R
    et al.
    Sabouri, Nasim
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Webb, Christopher J
    Zakian, Virginia A
    The Pif1 family helicase Pfh1 facilitates telomere replication and has an RPA-dependent role during telomere lengthening2014Inngår i: DNA Repair, ISSN 1568-7864, E-ISSN 1568-7856, Vol. 24, s. 80-86Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pif1 family helicases are evolutionary conserved 5'-3' DNA helicases. Pfh1, the sole Schizosaccharomyces pombe Pif1 family DNA helicase, is essential for maintenance of both nuclear and mitochondrial DNAs. Here we show that its nuclear functions include roles in telomere replication and telomerase action. Pfh1 promoted semi-conservative replication through telomeric DNA, as replication forks moved more slowly through telomeres when Pfh1 levels were reduced. Unlike other organisms, S. pombe cells overexpressing Pfh1 displayed markedly longer telomeres. Because this lengthening occurred in the absence of homologous recombination but not in a replication protein A mutant (rad11-D223Y) that has defects in telomerase function, it is probably telomerase-mediated. The effects of Pfh1 on telomere replication and telomere length are likely direct as Pfh1 exhibited high telomere binding in cells expressing endogenous levels of Pfh1. These findings argue that Pfh1 is a positive regulator of telomere length and telomere replication.

  • 309.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Malmgren, Joel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Klinke, Felix J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis of diaryliodonium triflates using environmentally benign oxidizing agents2009Inngår i: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, nr 14, s. 2277-2280Artikkel i tidsskrift (Fagfellevurdert)
  • 310. Miralles Fusté, Javier
    et al.
    Shi, Yonghong
    Wanrooij, Sjoerd
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Zhu, Xuefeng
    Jemt, Elisabeth
    Persson, Orjan
    Sabouri, Nasim
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Gustafsson, Claes M
    Falkenberg, Maria
    In vivo occupancy of mitochondrial single-stranded DNA binding protein supports the strand displacement mode of DNA replication2014Inngår i: PLOS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 10, nr 12, s. e1004832-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mitochondrial DNA (mtDNA) encodes for proteins required for oxidative phosphorylation, and mutations affecting the genome have been linked to a number of diseases as well as the natural ageing process in mammals. Human mtDNA is replicated by a molecular machinery that is distinct from the nuclear replisome, but there is still no consensus on the exact mode of mtDNA replication. We here demonstrate that the mitochondrial single-stranded DNA binding protein (mtSSB) directs origin specific initiation of mtDNA replication. MtSSB covers the parental heavy strand, which is displaced during mtDNA replication. MtSSB blocks primer synthesis on the displaced strand and restricts initiation of light-strand mtDNA synthesis to the specific origin of light-strand DNA synthesis (OriL). The in vivo occupancy profile of mtSSB displays a distinct pattern, with the highest levels of mtSSB close to the mitochondrial control region and with a gradual decline towards OriL. The pattern correlates with the replication products expected for the strand displacement mode of mtDNA synthesis, lending strong in vivo support for this debated model for mitochondrial DNA replication.

  • 311.
    Miyasaka, Keiichi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi.
    A structural study into the boundary surface and associated curvature of three-dimensional mesoporous silica crystals2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Since their first discovery in the early 1990s, mesoporous crystals (MCs) have fascinated researchers in various fields because of their interesting structures and their potential uses. Electron crystallography (EC) gives the direct three-dimensional (3D) realization of a crystal as a reconstructed electrostatic potential map (EPM). Various 3D-EPMs of silica MCs with cubic symmetry have been previously obtained by EC.

    The main task in this thesis is the development of structural analyses focusing on MCs and thus to evaluate the properties of periodic mesopores within EC data. How MC structures can be described and solved by EC is discussed in terms of the interpretation of the reconstructed 3D-EPM. Assuming a regime of an equi-potential surface (EPS), a structural description for MCs is suggested as a surface that optimizes the curvature elasticity evaluated on every EPS. The geometric properties of cubic MCs so far already reconstructed by EC, are then analyzed on the basis of the optimized EPSs. The analysis provides the property of the mesopores independently from gas adsorption measurements. A large cage-like MC is further studied by in-situ synchrotron powder X-ray diffraction to help understand the nitrogen adsorption process onto the mesopore wall.

    As an additional study, a silica MC showing its crystal morphologies of icosahedron, decahedron, etc. is studied. Results by EC suggest that the spherical uni-modal cages form the cubic close packing. The morphologies observed are explained in terms of the multiple twinning, which is analogous to metal nanoparticles. The occurrence of multiple twinning in MCs is discussed in light of the synthesis condition and the shape of micelles.

  • 312.
    Mollick, Tanzina
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Photoreceptor degeneration, second order neuron remodeling and glia reactivity in an in vivo and in vitro model of retinal neurodegeneration2016Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Photoreceptors have the ability to last during the entire lifespan of an individual. Being the first line of neurons in the visual transduction pathway, their health and maintenance is eminent for proper retinal function. However, photoreceptors are susceptible to neurodegenerative retinal dystrophies. A number of retinal pathologies such as retinitis pigmentosa, age-related amacular degeneration and diabetic retinopathy have been linked to photoreceptor death. Moreover, photoreceptor degeneration has been shown to affect downstream inner nuclear layer cells as well as induce reactive responses from Müller cells and microglia. Since current treatments are ineffective in preventing the degeneration of these neurons, intense research is still underway to discover novel treatment modalities. In this thesis, photoreceptor degeneration was assessed in an in vivo and in vitro model of neurodegeneration. Moreover, a possible mode of preserving these neurons by the use of human neural progenitor cells (hNPCs) was investigated. The in vivo pdgf-bret/ret (platelet derived growth factor-b retention motif knockout) mouse model, which shows severe vascular pathology as a result of detachment of pericytes from the vascular endothelium, was studied during the first postnatal month. In a short time span, i.e. between postnatal day (P)10 and P15, retinopathic features were observed. Photoreceptor degeneration related to cell death, cone outer segment (OS) shortening and synapse disassembly in the outer plexiform layer (OPL) was seen. The second order rod bipolar cells underwent remodeling and the Müller cells became gliotic with increased expression of GFAP (glial fibrillary acidic protein). Microglial cells were also observed to convert to their reactive amoeboid-like phenotype. These features seemed to become more severe in the older P28 mutants. In the in vitro porcine retinal explant model, photoreceptor death significantly increased by 3 days in vitro (div). This was associated with loss of cone OSs, opsin mislocalization and loss of synaptic integrity in the OPL. Horizontal cell death and remodeling was also observed together with a severe gliotic response from the Müller cells. Human neural progenitor cell cocultured explants for 3 div had the ability to preserve photoreceptor survival by means of OS conservation, better opsin trafficking and maintaining synaptic integrity. However, Müller cell gliosis was only mitigated by a decreased density of GFAP immunoreactive Müller cells. In conclusion, both the in vivo and in vitro model of neurodegeneration demonstrate the vulnerability of photoreceptors to various mechanisms of retinal injury. Interestingly, hNPC derived neurotrophic factors had neuroprotective qualities in 3 div porcine retinal explants.

  • 313.
    Montibon, Elson
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemiteknik.
    Lestelius, Magnus
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemiteknik.
    Järnström, Lars
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemiteknik.
    Preparation of Electroconductive Paper by Coating Blends of Poly(3,4-ethylenedioxythiophene)/Poly(4-styrenesulfonate)(PEDOT:PSS) and Organic Solvents2009Inngår i: Proceedings of the TAPPI Coating and Graphic Arts Conference (PaperCon '09), 2009Konferansepaper (Fagfellevurdert)
  • 314.
    Moreira Bastos, Patricia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljökemi.
    Comparison of experimentally and theoretically determined oxidation and photochemical transformation rates of some organohalogens to promote prediction of persistence2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The diversity of choices we have to make everyday influence our environment and ourselves in more ways than most of us realise. Anthropogenic substances, such as flame retardants, date back as early as 450 BC when the Egyptians used alum to reduce flammability. The increasing demand for new articles has led to an increased production of chemical substances, for which many are commercially produced without complete knowledge on properties such as persistence, bioaccumulation and toxicology (PBT). Commercial compounds may be properly tested and denominated as “safe” regarding PBT properties, but their degradation products and/or metabolites may cause environmental impact.

    The availability of uniform and accurate data for prediction of persistence is of key importance for the understanding of chemical fate. A method to determine the susceptibility of chemicals to undergo oxidation in water has been developed and applied on several organohalogens, including PBDEs and OH-PBDEs. The method was used to determine reaction rates and the group of OH-PBDEs were subsequently subjected to photolysis by use of UV-light. Hence, susceptibility to undergo both oxidation and photolysis for the OH-PBDEs were investigated and compared to previously reported degradation rates on PBDEs.

    As a final step in promoting the prediction of persistence, Quantitative structure-property relationship (QSPR) models were performed on a set of compounds which had undergone photolytic degradation under similar conditions. The QSPRs were used as a preliminary step in predicting photolysis half-lives for chemical substances and to determine which physicochemical descriptors are of greatest importance thereof.

    This thesis presents the possibility of performing and assessing oxidation transformations on compounds of low and high water solubility, photolysis transformations in various media and using obtained data to predict behaviour via QSPR models, to promote predictions of persistence.

  • 315.
    Morelli, Paula I.
    et al.
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden / Wallenberg Laboratory, Sahlgrenska University Hospital, Göteborg, Sweden.
    Martinsson, Sofia
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Östergren-Lundén, Gunnel
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Fridén, Vincent
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Moses, Jonatan
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Bondjers, Göran
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Krettek, Alexandra
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    Lustig, Florentyna
    Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
    IFN gamma regulates PDGF-receptor alpha expression in macrophages, THP-1 cells, and arterial smooth muscle cells2006Inngår i: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 184, nr 1, s. 39-47Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The recruitment of monocyte-derived macrophages (MDMs) and arterial smooth muscle cells (ASMCs) contributes to inflammation and development of intimal hyperplasia during atherosclerosis. Platelet-derived growth factor (PDGF) is a potent mitogen for SMC, signalling through PDGF-receptor subunits alpha (Ralpha) and beta (Rbeta). We have previously found that interferon gamma (IFNgamma) upregulates PDGF-Ralpha mRNA expression in human MDM (hMDM) which causes an increased migration towards PDGF. In the present study, we found that IFNgamma mediated an upregulation of PDGF-Ralpha mRNA also in THP-1 cells. The induction of PDGF-Ralpha in both hMDM and THP-1 cells was caused by STAT1 binding to the PDGF-Ralpha promoter. In human ASMCs, IFNgamma again stimulated a transient STAT1-binding to the PDGF-Ralpha promoter. However, this was not followed by an upregulation of PDGF-Ralpha mRNA. IFNgamma-stimulation resulted in augmented expression of PDGF-Ralpha protein in differentiated hMDM. Early hMDM only expressed an immature and not fully glycosylated form of the PDGF-Ralpha protein. In contrast, THP-1 cells did not synthesize PDGF-Ralpha protein, implying further posttranscriptional inhibition. Our results contribute to a better understanding of the complex regulation of PDGF-Ralpha expression and how proinflammatory factors may contribute to PDGF-related hyperplasia in vascular diseases.

  • 316.
    Mortensen, Anja C
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi.
    Spiegelberg, Diana
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Haylock, Anna-Karin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Lundqvist, Hans
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi.
    Nestor, Marika
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi.
    Preclinical evaluation of a novel engineered recombinant humananti-CD44v6 antibody for potential use in radio-immunotherapy2018Inngår i: International Journal of Oncology, ISSN 1019-6439Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    CD44v6 is overexpressed in a variety of cancers,rendering it a promising target for radio-immunotherapy (RIT).In this study, we have characterized a novel engineered recombinantmonoclonal anti-CD44v6 antibody, AbN44v6, andassessed its potential for use in RIT using either 177Lu or 131Ias therapeutic radionuclides. In vitro affinity and specificityassays characterized the binding of the antibody labeled with177Lu, 125I or 131I. The therapeutic effects of 177Lu-AbN44v6 and131I-AbN44v6 were investigated using two in vitro 3D tumormodels with different CD44v6 expression. Finally, the normaltissue biodistribution and dosimetry for 177Lu-AbN44v6 and125I-AbN44v6/131I-AbN44v6 were assessed in vivo using amouse model. All AbN44v6 radioconjugates demonstratedCD44v6-specific binding in vitro. In the in vitro 3D tumormodels, dose-dependent therapeutic effects were observedwith both 177Lu-AbN44v6 and 131I-AbN44v6, with a greatersignificant therapeutic effect observed on the cells with a higherCD44v6 expression. Biodistribution experiments demonstrateda greater uptake of 177Lu-AbN44v6 in the liver, spleen and bone,compared to 125I-AbN44v6, whereas 125I-AbN44v6 demonstrateda longer circulation time. In dosimetric calculations, thecritical organs for 177Lu-AbN44v6 were the liver and spleen,whereas the kidneys and red marrow were considered the criticalorgans for 131I-AbN44v6. The effective dose was in the order of0.1 mSv/MBq for both labels. In conclusion, AbN44v6 boundspecifically and with high affinity to CD44v6. Furthermore,in vitro RIT demonstrated growth inhibition in a CD44v6-specific activity-dependent manner for both radioconjugates,demonstrating that both 177Lu-AbN44v6 and 131I-AbN44v6 maybe promising RIT candidates. Furthermore, biodistributionand dosimetric analysis supported the applicability of bothconjugates for RIT. The CD44v6-specific therapeutic effectsobserved with radiolabeled AbN44v6 in the 3D tumor modelsin vitro, combined with the beneficial dosimetry

  • 317.
    Moses Matti, Nuha
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Undersökning av Ammoniumoxiderande Arkéer i reningsverks slam2010Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Livsformerna på jorden delas systematiskt in i de tre domänerna bakterier, arkéer och eukaryoter. Arkéer är de mikroorganismer som lever i extrema miljöer såsom hetvattenkällor, sjöar med hög salthalt och i miljöer med extrema pH-värden. De kan existera i miljöer där inga andra organismer överlever men förekommer även rikligt överallt runtomkring oss, exempelvis i människans mage och som normalflora i munnen.

    Vissa bakterier och arkéer har genen för enzymet ammoniak monooxygenas (AMO). Detta enzym spelar en viktig roll vid rening av avloppsvatten genom att oxidera ammonium till nitrit.

    Syftet med detta examensarbete har varit att detektera arkéer i prover av aktivt slam vilket gjordes genom att optimera en Polymerase Chain Reaction (PCR) baserad metod. Först pelleterades slamproverna via centrifugering för att kunna preparera DNA. Detta DNA användes som templat för optimering av PCR med specifika primers för AMO genen hos arkéer. De PCR produkter som erhölls från det optimerade programmet klonades och transformerades in i Escherichia coli. Därefter sekvenserades PCR produkterna för att identifiera vilka ammonium oxiderande arkéer som fanns i proverna.

    De amplifierade gensekvenserna visade god överensstämmelse med den förväntade nukleotidsekvensen för arkéer. Samtliga gensekvenser passade bäst in på icke odlingsbara arkéer enligt databasen BLAST. Genom att välja bort icke odlingsbara arkéer i sökningen kunde arkéen Nitrosopumilus maritimus identifieras, vilket är en av få odlade arkéer med AMO-genen sekvens bestämd.

  • 318.
    Muradrasoli, Shaman
    et al.
    Uppsala University ; Swedish University of Agricultural Sciences.
    Bálint, Adám
    Swedish University of Agricultural Sciences ; National Veterinary Institute.
    Wahlgren, John
    Karolinska Institutet ; Swedish Institute for Infectious Disease Control.
    Waldenström, Jonas
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV. Swedish Institute for Infectious Disease Control.
    Belák, Sándor
    Swedish University of Agricultural Sciences ; National Veterinary Institute.
    Blomberg, Jonas
    Uppsala University.
    Olsen, Björn
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV. Uppsala University.
    Prevalence and phylogeny of coronaviruses in wild birds from the Bering Strait area (Beringia)2010Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, nr 10, artikkel-id e13640Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Coronaviruses (CoVs) can cause mild to severe disease in humans and animals, their host range and environmental spread seem to have been largely underestimated, and they are currently being investigated for their potential medical relevance. Infectious bronchitis virus (IBV) belongs to gamma-coronaviruses and causes a costly respiratory viral disease in chickens. The role of wild birds in the epidemiology of IBV is poorly understood. In the present study, we examined 1,002 cloacal and faecal samples collected from 26 wild bird species in the Beringia area for the presence of CoVs, and then we performed statistical and phylogenetic analyses. We detected diverse CoVs by RT-PCR in wild birds in the Beringia area. Sequence analysis showed that the detected viruses are gamma-coronaviruses related to IBV. These findings suggest that wild birds are able to carry gamma-coronaviruses asymptomatically. We concluded that CoVs are widespread among wild birds in Beringia, and their geographic spread and frequency is higher than previously realised. Thus, Avian CoV can be efficiently disseminated over large distances and could be a genetic reservoir for future emerging pathogenic CoVs. Considering the great animal health and economic impact of IBV as well as the recent emergence of novel coronaviruses such as SARS-coronavirus, it is important to investigate the role of wildlife reservoirs in CoV infection biology and epidemiology.

  • 319.
    Mårtensson, Ellinor
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Foaming in Apple Wine2010Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    At Kiviks Musteri AB, situated in the southeast part of Scania, a wide variety of products based on fruits and berries, are produced. One of these products is base apple wine, which is used for the production of cider and mulled wine and also is sold to other producers of cider. A foaming problem has occurred at some customers when the cider is bottled, and this problem has been traced to the base wine. The aim of this paper is to investigate what causes the foaming and how the foaming is affected by the clarifying agents used during the production of the wine. An investigation whether silica based antifoaming agents might be a solution of the problem will be performed. During the work fermentations, clarification and foaming tests will be performed in laboratory scale in Kivik. Tests with four different silica based antifoaming compounds are carried out and on these samples the surface tension and viscosity are measured to see how these factors correlate with the foaming when antifoaming agents are added to the wine. What is more, fermentations with a new yeast type and fermentations with less fruit are made to investigate if this could give better foaming properties in the wine.

    The tests showed that it is probably proteins that are the main cause of the foaming, but an increase of the amount of bentonite, the clarifying agent reducing protein content in the wine, is not possible since this causes too much sediment. Antifoaming agents gave reduced foaming times, which were at an acceptable level, but when the wine was mixed to cider base and filtered the effect was lost. No significant differences were observed between the four antifoaming compounds. The test with the new yeast type gave no positive results when it came to foaming. The test with less fruit showed a decrease in foaming but not sufficient enough.

  • 320.
    Mörén, Lina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Metabolomics and proteomics studies of brain tumors: a chemometric bioinformatics approach2015Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The WHO classification of brain tumors is based on histological features and the aggressiveness of the tumor is classified from grade I to IV, where grade IV is the most aggressive. Today, the correlation between prognosis and tumor grade is the most important component in tumor classification. High grade gliomas, glioblastomas, are associated with poor prognosis and a median survival of 14 months including all available treatments. Low grade meningiomas, usually benign grade I tumors, are in most cases cured by surgical resection. However despite their benign appearance grade I meningiomas can, without any histopathological signs, in some cases develop bone invasive growth and become lethal. Thus, it is necessary to improve conventional treatment modalities, develop new treatment strategies and improve the knowledge regarding the basic pathophysiology in the classification and treatment of brain tumors.

    In this thesis, both proteomics and metabolomics have been applied in the search for biomarkers or biomarker patterns in two different types of brain tumors, gliomas and meningiomas. Proteomic studies were carried out mainly by surface enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS). In one of the studies, isobaric tags for relative and absolute quantitation (iTRAQ) labeling in combination with high-performance liquid chromatography (HPLC) was used for protein detection and identification. For metabolomics, gas-chromatography time-of-flight mass spectrometry (GC-TOF-MS) has been the main platform used throughout this work for generation of robust global metabolite profiles in tissue, blood and cell cultures. To deal with the complexity of the generated data, and to be able to extract relevant biomarker patters or latent biomarkers, for interpretation, prediction and prognosis, bioinformatic strategies based on chemometrics were applied throughout the studies of the thesis.

    In summary, we detected differentiating protein profiles between invasive and non-invasive meningiomas, in both fibrous and meningothelial tumors. Furthermore, in a different study we discovered treatment induce protein pattern changes in a rat glioma model treated with an angiogenesis inhibitor. We identified a cluster of proteins linked to angiogenesis. One of those proteins, HSP90, was found elevated in relation to treatment in tumors, following ELISA validation. An interesting observation in a separate study was that it was possible to detect metabolite pattern changes in the serum metabolome, as an effect of treatment with radiotherapy, and that these pattern changes differed between different patients, highlighting a possibility for monitoring individual treatment response.  In the fourth study of this work, we investigated tissue and serum from glioma patients that revealed differences in the metabolome between glioblastoma and oligodendroglioma, as well as between oligodendroglioma grade II and grade III. In addition, we discovered metabolite patterns associated to survival in both glioblastoma and oligodendroglioma. In our final work, we identified metabolite pattern differences between cell lines from a subgroup of glioblastomas lacking argininosuccinate synthetase (ASS1) expression, (ASS1 negative glioblastomas), making them auxotrophic for arginine, a metabolite required for tumor growth and proliferation, as compared to glioblastomas with normal ASS1 expression (ASS1 positive). From the identified metabolite pattern differences we could verify the hypothesized alterations in the arginine biosynthetic pathway. We also identified additional interesting metabolites that may provide clues for future diagnostics and treatments. Finally, we were able to verify the specific treatment effect of ASS1 negative cells by means of arginine deprivation on a metabolic level.

  • 321.
    Naessén, Tord
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa.
    Kushnir, Mark M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Chaika, Andrey
    Donetsk State Medical University, Ukraine.
    Nosenko, Jelena
    Donetsk State Medical University, Ukraine.
    Mogilevkina, Iryna
    Donetsk State Medical University, Ukraine.
    Rockwood, Alan L.
    ARUP Institute for Clinical and Experimental Pathology, Utah.
    Carlström, Kjell
    Karolinska Institute.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Kirilovas, Dmitrijus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa.
    Steroid profiles in ovarian follicular fluid in women with and without polycystic ovary syndrome, analyzed by liquid chromatography-tandem mass spectrometry.2010Inngår i: Fertility and Sterility, ISSN 0015-0282, E-ISSN 1556-5653, Vol. 94, nr 6, s. 2228-2233Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE

    To compare steroid concentrations and steroid product-to-precursor ratios in ovarian follicular fluid (FF) from women with polycystic ovary syndrome (PCOS) and from regularly menstruating women in their early follicular phase, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Polycystic ovary syndrome involves abnormal regulation of the steroidogenic enzymes, leading to arrest of follicle development.

    DESIGN

    Case-control study.

    SETTING

    University hospital clinic.

    PATIENT(S)

    Follicular fluid from size-matched ovarian follicles (5-8 mm) in 27 nonstimulated women with PCOS and in 21 women without PCOS was sampled. Thirteen steroids were quantitated from 40 muL of FF, using LC-MS/MS.

    INTERVENTION(S)

    None.

    MAIN OUTCOME MEASURE(S)

    Concentrations of steroids in the FF and product-to-precursor ratios (enzyme activity) were compared between the groups.

    RESULT(S)

    In women with PCOS, ovarian FF contained higher concentrations of individual and total androgens, lower individual and total estrogens (E), and a lower total E-to-androgen ratio, compared with regularly menstruating women. The product-to-precursor concentration ratios indicated higher CYP17-linked and lower CYP19-linked (aromatase) enzyme activity. Receiver operating characteristic plots indicated the early CYP17 step (17-OH5P/5P) being highly important for the prevalence of PCOS (c = 0.95).

    CONCLUSION(S)

    The women with PCOS had higher ovarian CYP17-linked and lower CYP19-linked (aromatase) enzyme activity, confirming previous data. Multiple steroid assessments from minute volumes including FF from nonstimulated ovaries, using LC-MS/MS, might be useful in research, clinical endocrinology, and in IVF.

  • 322.
    Nakka, Sravya Sowdamini
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Development of novel tools for prevention and diagnosis of Porphyromonas gingivalis infection and periodontitis2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Periodontitis is a chronic inflammatory disease caused by exaggerated host immune responses to dysregulated microbiota in dental biofilms leading to degradation of tissues and alveolar bone loss. Porphyromonas gingivalis is a major periodontal pathogen and expresses several potent virulence factors. Among these factors, arginine and lysine gingipains are of special importance, both for the bacterial survival/proliferation and the pathological outcome. The major aim of this thesis was to develop and test novel methods for diagnosis and prevention of P. gingivalis infection and periodontitis. In study I, anti-P. gingivalis antibodies were developed in vitro for immunodetection of bacteria in clinical samples using a surface plasmon resonance (SPR)-based biosensor. Specific binding of the antibodies to P. gingivalis was demonstrated in samples of patients with periodontitis and the results were validated using real-time PCR and DNA-DNA checkerboard analysis. In study II, we elucidated the properties and antimicrobial effects of different lactobacillus species and the two-peptide bacteriocin PLNC8 αβ on P. gingivalis. L. plantarum NC8 and 44048 effectively inhibited P. gingivalis growth and pure PLNC8 αβ induced bacterial lysis by damaging P. gingivalis membrane. In study III, we demonstrated that PLNC8 αβ dose-dependently induces proliferation and release of growth factors in gingival epithelial cells (GECs). Furthermore, PLNC8 αβ decreased P. gingivalis-induced cytotoxic effects in GECs but did not alter the effect of gingipains on cytokine expression. In study IV, we elucidated the effects of anti-P. gingivalis antibodies and PLNC8 αβ in regulating cellular responses during P. gingivalis infection. Both antibodies and PLNC8 αβ modulated P. gingivalis-induced expression of growth factors in GECs, however, their effects were diminished when used in combination. The results of this thesis demonstrate a possible role of anti-P. gingivalis antibodies and PLNC8 αβ in prevention and treatment of P. gingivalis infection and periodontitis with no cytotoxic effects on human cells.

  • 323.
    Nakka, Sravya Sowdamini
    et al.
    Örebro universitet, Institutionen för medicinska vetenskaper. The Institution for Protein Environmental Affinity Surveys, PEAS Institut AB, Linköping, Sweden.
    Palm, Eleonor
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Bengtsson, Torbjörn
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Khalaf, Hazem
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Bacteriocin plantaricin NC8 αβ antagonizes Porphyromonas gingivalis infection and induces proliferation of gingival epithelial cellsManuskript (preprint) (Annet vitenskapelig)
  • 324.
    Nakka, Sravya Sowdamini
    et al.
    Örebro universitet, Institutionen för medicinska vetenskaper. The Institution for Protein Environmental Affinity Surveys, PEAS Institut AB, Linköping, Sweden.
    Palm, Eleonor
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Nayeri, Fariba
    The Institution for Protein Environmental Affinity Surveys, PEAS Institut AB, Linköping, Sweden; Division of Infectious Diseases, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
    Bengtsson, Torbjörn
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Khalaf, Hazem
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Effects of plantaricin NC8 αβ and antibodies on gingival epithelial cells infected by Porphyromonas gingivalisManuskript (preprint) (Annet vitenskapelig)
  • 325.
    Nevalainen, Nina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Histologi med cellbiologi. nina.nevalainen@diagrad.umu.se.
    Af Bjerkén, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Histologi med cellbiologi.
    Gerhardt, G A
    Department of Anatomy, Neurobiology, and Neurology, University of Kentucky Medical Center, Lexington, KY, USA.
    Strömberg, Iingrid
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Histologi med cellbiologi.
    Serotonergic nerve fibers in l-DOPA-derived dopamine release and dyskinesia2014Inngår i: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 260, s. 73-86Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The 5-HT (5-hydroxytryptamine) system has been assigned a key role in the development of 3,4-dihydroxyphenyl-l-alanine (l-DOPA)-induced dyskinesia, mainly due to 5-HT neuronal ability to decarboxylate l-DOPA into dopamine. Nevertheless, knowledge of l-DOPA-induced events that could lead to development of dyskinesias are limited and therefore the present work has evaluated (i) the role of the 5-HT system in l-DOPA-derived dopamine synthesis when dopamine neurons are present, (ii) l-DOPA-induced effects on striatal dopamine release and clearance, and on 5-HT nerve fiber density, and (iii) the behavioral outcome of altered 5-HT transmission in dyskinetic rats. Chronoamperometric recordings demonstrated attenuated striatal l-DOPA-derived dopamine release (∼30%) upon removal of 5-HT nerve fibers in intact animals. Interestingly, four weeks of daily l-DOPA treatment yielded similar-sized dopamine peak amplitudes in intact animals as found after a 5-HT-lesion. Moreover, chronic l-DOPA exposure attenuated striatal 5-HT nerve fiber density in the absence of dopamine nerve terminals. Furthermore, fluoxetine-induced altered 5-HT transmission blocked dyskinetic behavior via action on 5-HT1A receptors. Taken together, the results indicate a central role for the 5-HT system in l-DOPA-derived dopamine synthesis and in dyskinesia, and therefore potential l-DOPA-induced deterioration of 5-HT function might reduce l-DOPA efficacy as well as promote the upcoming of motor side effects.

  • 326. Nieberding, Caroline. M.
    et al.
    de Vos, Helena
    Schneider, Maria V.
    Lassance, Jean-Marc
    Estramil, Natalia
    Andersson, Jimmy
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Bång, Joakim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Löfstedt, Christer
    Brakefield, Paul M.
    The Male Sex pheromone of the Butterfly Bicyclus anynana: Towards an Evolutionary Analysis2008Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 3, nr 7, s. e2751-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies.

    Methodology/Principal Findings: Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP.

    Conclusions/Significance: This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.

  • 327.
    Nilsson, Fritjof
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Gedde, Ulf W.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Small-Molecule Diffusion in Semicrystalline Polymers as Revealed by Experimental and Simulation Studies2010Inngår i: POLYCHAR-18 WORLD FORUM ON ADVANCED MATERIALS / [ed] Mormann, W., Weinheim: WILEY-V C H VERLAG , 2010, Vol. 298, s. 108-115Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Diffusion of n-hexane in poly(ethylene-co-1-hexene)s with 15-75 wt.% crystallinity was studied by desorption experiments analyzing data using the Fickian equations with a concentration dependent diffusivity. The effect of the impenetrable crystalline phase on the penetrant diffusivity (D) is described by D = D-a/(tau beta), where D-a is the diffusivity of the amorphous polymer, tau is the geometrical impedance factor and beta is a factor describing the constraining effect of the crystals on the non-crystalline phase. For a polymer with 75 wt.% crystallinity, tau beta varied markedly with penetrant concentration (V-1a) in the penetrable phase: 1000 (V-1a = 0) and 10 (V-1a = 0.15). This penetrant-uptake had no effect on the gross crystal morphology, i.e. beta must be strongly dependent on V-1a. Samples saturated in n-hexane exhibited a penetrant-induced loosening of the interfacial structure, as revealed by an increase in crystal density that require an increased mobility in the interfacial component and by a decrease in the intensity of the asymmetric X-ray scattering associated with the interfacial component. The geometrical impedance factor has been modelled by mimicking spherulite growth and tau was obtained as the ratio of the diffusivities of the fully amorphous and semicrystalline systems. The maximum tau obtained from these simulations is ca. ten, which suggests that beta in the systems with V-1a = 0.15 takes values close to unity. The simulations showed that the geometrical impedance factor is insensitive to the ratio of the crystal width and the crystal thickness. A free path length scaling parameter characteristic of the amorphous phase correlated with tau.

  • 328.
    Nilsson, Jenny
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Förskolebarns tankar om vattnets kretslopp i naturen och i samhället.: skiljer sig pojkars och flickors svar åt?2009Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Abstract

    The work will give the picture of what four- and five-year-olds know about the water cycle in nature and in the society. Is there any difference depending on whether a boy or a girl is answering? The work will as well try to describe a picture of how a pre-school could plan their work on a sustainable society, science, and increased gender equality. To answer these questions the information has been received from interviews with children and by studying pre-school’s local plan. 

       Earlier research on the area of water shows that it is important before working with a new topic to find out what knowledge the children already have, so that the process could be as worthwhile as possible. The proceeding work should be based on children’s previous knowledge of the topic.

       The research has been done on twelve four- and five-year-old children with the help of individual interviews. The result of the research shows that the children have some knowledge of the words which are important for understanding of the water cycle in nature, but they are not capable of talking about the entirety, as the complete cycle. The water cycle in the society is even more difficult for the children to describe, although there were some children who could explain the function of the water tower. The children do not even show the understanding or knowledge of the words which are included into the concept. The local plan gives a good picture of how the work could be planned in an appropriate way to increase the environmental awareness and equality.

       To sum up, this work will show a picture of what children know nowadays about the water cycle. Different answers can be received depending on the location of the pre-school. Identical background can lead to similar answers. If pre-schools have an opportunity to go to the forest often, the children then have the experience from there as well and answer more similar than if the opportunity doesn’t exist. The teacher shall help the children to explore there environment in as simple and interesting way. A well-planned local plan helps the pre-school become as good as possible. The children feel participating if they get attention and praise. 

    Key-words: The water cycle, Children's thoughts, Gender, Local plan.

  • 329.
    Nilsson, Rickard
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    AMPK Expression in Denervated Atrophic and Hypertrophic Skeletal Muscle2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 330.
    Nilsson, Therese
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Interaction between Oil Content, pH and Preservatives and their Effect on Zygosaccharomyces bailii and Lactobacillus plantarum in Mayonnaise Type Products2010Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
  • 331.
    Norberg, Thomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi II.
    Synthesis of phosphodiester-linked microbial polysaccharide structures2009Inngår i: Progress in the synthesis of complex carbohydrate chains of plant and microbial polysaccharides / [ed] N. E. Nifantiev, Trivandrum: Transworld Research Network , 2009, s. 309-325Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This chapter reviews work published until mid-2008 on the synthesis of phosphodiester-linked microbial polysaccharide structures, with emphasis on the development during the last two decades. Different techniques and chemistries that have been used to create the phosphodiester linkages are discussed, and syntheses of oligomeric (2-10 repeating units) phosphodiester-linked fragments of natural polysaccharides from different sources are presented.

  • 332. Nordberg, Agneta
    et al.
    Hartvig, Per
    Lundkvist, Hans
    Antoni, Gunnar
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen.
    Ulin, Johan
    Långström, Bengt
    Uptake and distribution of (+)-R and (-)-S N-[methyl-11C]nicotine in brains of rhesus    monkey- an attempt to study nicotine receptors in vivo.1989Inngår i: J neurol trans 1, s. 195-205Artikkel i tidsskrift (Fagfellevurdert)
  • 333. Nordberg, Agneta
    et al.
    Rinne, Juha O.
    Kadir, Ahmadul
    Långström, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    The use of PET in Alzheimer disease2010Inngår i: Nature Reviews Neurology, ISSN 1759-4758, Vol. 6, nr 2, s. 78-87Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In Alzheimer disease (AD), which is the most common cause of dementia, the underlying disease pathology most probably precedes the onset of cognitive symptoms by many years. Thus, efforts are underway to find early diagnostic markers as well as disease-modifying treatments for this disorder. PET enables various brain systems to be monitored in living individuals. In patients with AD, PET can be used to investigate changes in cerebral glucose metabolism, various neurotransmitter systems, neuroinflammation, and the protein aggregates that are characteristic of the disease, notably the amyloid deposits. These investigations are helping to further our understanding of the complex pathophysiological mechanisms that underlie AD, as well as aiding the early and differential diagnosis of the disease in the clinic. In the future, PET studies will also be useful for identifying new therapeutic targets and monitoring treatment outcomes. Amyloid imaging could be useful as early diagnostic marker of AD and for selecting patients for anti-amyloid-beta therapy, while cerebral glucose metabolism could be a suitable PET marker for monitoring disease progression. For the near future, multitracer PET studies are unlikely to be used routinely in the clinic for AD, being both burdensome and expensive; however, such studies are very informative in a research context.

  • 334.
    Nordborg, Anna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Synthesis and modifications of materials for separation science2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis deals with the preparation of materials for use in separation science and their surface modification by grafting. The overall aim is the preparation of diverse materials by combination of a set of developed tools.

    Included in the thesis is the synthesis of monolithic media using non-traditional crosslinkers, the characterization of their porous properties and initial testing in reversed-phase chromatographic separation of proteins. The preparation of a library of short polymer chains, telomers, with varied functionality and their characterization is reported. Included in the characterization is the gradient polymer elution chromatography of selected telomers on a monolithic column in capillary format. The technique shows promise as a tool for monitoring of polymerization processes and for the separation of telomers with similar size but different functionalities or characteristics.

    Finally, the combination of polymeric support materials and the prepared telomer library is used in surface modification. Surface modification is performed onto activated surfaces via a “grafting to” approach. One example is shown, the surface modification of epoxy-modified divinylbenzene particles by attachment of telomer chains introducing ion-exchange functionality. The material is tested for the separation of proteins, in ion-exchange chromatography mode.

  • 335.
    Nordqvist, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa.
    Endometrial gene expression related to recurrent miscarriage2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    A woman’s uterus is a safe place for the baby to grow and get nourished which is not always the case since the endometrium can, due to some underlying causes repel the fertilised egg which in other words means that the woman undergoes miscarriage. Recurrent miscarriage is defined as three or more pregnancy losses before 22 weeks of gestation. Multiple etiologies is thought to cause recurrent miscarriage although still 50 % of these cases remains unknown. The aim of this study was to measure the gene expression of DKK1, STC1, TK1, IL8 and OLFM1 in the endometrium of women with recurrent miscarriage compared to fertile women by using quantitative real-time PCR (qPCR) with TaqMan probes and primers. Immunohistochemical staining of paraffin embedded endometrium tissue was performed with a primary antibody anti-IL8 for detection of the IL8-protein. No significant difference was seen in mRNA expression between the two groups, only the IL8 mRNA showed a tendency to significant difference between the groups, p=0,063. On protein level, the immunohistochemical staining of IL8 showed few stained cells in both groups. Interestingly, the number of cells was clearly more abundant in women with recurrent miscarriage than in fertile women, p=0,036. The main conclusion from this study is that the high number of IL8 produced cells in the endometrium may be a contributing factor to recurrent miscarriage and need to be investigated further.

  • 336.
    Norlin, Rikard
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Juhlin, Lars
    Swedish Defence Research Agency, Division of NBC-Defence, Department of Threat Assessment, Umeå.
    Lind, Per
    Swedish Defence Research Agency, Division of NBC-Defence, Department of Threat Assessment, Umeå.
    Trogen, Lars
    Swedish Defence Research Agency, Division of NBC-Defence, Department of Threat Assessment, Umeå.
    a-Haloenamines as reagents for the conversion of phosphorus oxyacids to their halogenated analogues2005Inngår i: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, nr 11, s. 1765-1770Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phosphorus oxyacids are converted to their halogenated analogues under mild conditions. α-Haloenamines are shown to be effective halogen transfer reagents affording good to high yields of the desired products at reaction times, in some cases, less than one minute.

  • 337.
    Norlin, Rikard
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Lindberg, Gösta
    Swedish Defence Research Agency, NBC-protection Division, Umeå .
    Synthesis of 14C Sarin2003Inngår i: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 6, s. 599-604Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Synthetic routes for the synthesis of [14C] sarin and related nerve agents are described. Triethyl phosphite and [14C] methyl iodide are reacted in the Michaelis-Arbusov reaction to produce diethyl methyl phosphonate which is converted to methylphosphonic acid by hydrolysis. After chlorination and subsequent fluorination the final product is formed by reaction with the appropriate alcohol.

  • 338.
    Norrbäck, Mattias
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Vitamin D metabolism in the enterocyte2010Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Vitamin D3, also known as cholecalciferol, can be produced by UV light from 7-dehydrocholesterol in the skin. However, as this synthesis is often insufficient, it should also be provided by the diet through fat fish, beef liver, miIk and egg yolk. Two successive hydroxylations occur to produce 1α,25(OH)2-D3, the biologically active form of vitamin D, which primarily functions to maintain the calcium and phosphorous homeostasis. Vitamin D is first hydroxylated in the liver by  D3-25-hydroxylase to 25(OH)D3. There have been several candidates suggested as the D3-25-hydroxylase such as the mitochondrial CYP27A enzyme. This enzyme is expressed in the liver, but it is also expressed in the intestinal cells of both rodents and humans. The aim of this project was to investigate whether a metabolization of the vitamin D3 could occur directly in the intestinal cell. Both an extraction method and two analytical HPLC methods were developed and used for comparing the putative vitamin D3 metabolization in HepG2 cell line (control) and the Caco-2 TC7 line. We first observed no spontaneous degradation when vitamin D3 was incubated in culture medium in similar conditions without cells. Then, a decrease of vitamin D3 joined with an increase in 25(OH)D3 were observed in both cell experiments in the apical medium. A small amount of 25(OH)D3 was detected in HepG2 cell compartment but not in the Caco-2 cells. This suggests that vitamin D3 can be incorporated into the HepG2 and Caco-2 cells, then metabolized and immediately re-secreted. Further research still needs to be done and we suggest conducting cell inhibitor experiments, evaluating the possible metabolization in mouse intestine by conducting ex vivo experiments, and finally validate these observations in humans with a postprandial experiment after a meal supplemented in vitamin D, which would definitely ensure the possible metabolization under dietary conditions.

  • 339.
    Norström, Sara H
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Soil and stream water chemistry in a boreal catchment - interactions, influences of dissolved organic matter and effects of wood ash application2010Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Two small bordering catchments in Bispgården, Central Sweden, wereinvestigated in regard to soil solution and stream water chemistry during the frostfree seasons of 2003-2007. Both catchments were drained by first order streams,Fanbergsbäcken and Gråbergsbäcken, and in Fanbergsbäckens catchment anextensive investigation of the soil and soil solution chemistry was conducted bylysimeter and centrifugation sampling. The area of intensive soil solutioninvestigation was situated in a slope towards a stream incorporating a rechargearea, with podzolic soil, and a discharge area close to the stream with an arenosolsoil. Samples were continuously taken in both the recharge- and the discharge areaof the slope, and stream water was sampled in the streams of both catchments. Themain variables of interest of the study were the interactions, the influence ofdissolved organic carbon and the effects of wood ash application to soil solutionand stream water.The natural variations and the interactions between soil solution and streamwater were monitored during 2003-2004. In soil solution, most of the investigatedsubstances tended to increase during the growing season, due to weathering andmicrobial degradation of biota. Ca, Mg, Al and Fe were highly associated todissolved organic carbon (DOC) throughout the catchment. The low molecularfraction of DOC seemed to have a higher impact on the soil processes in therecharge area, while high molecular DOC was more important for transport ofcations in the discharge area and the stream water.The concentration of different substances in the two streams differedsignificantly, even though the catchments were similar in size, shape andforestation. The seasonal patterns of most of the substances measured weresignificantly correlated between the streams, however. Cations and pH correlatedwell with DOC and flow. The flow pattern driven by precipitation seems to be thedriver of the stream water chemistry.Wood ash was applied at a dosage of 3 ton/ha to one of the catchments in theautumn of 2004, to investigate the initial effects on the soil solution- and streamwater chemistry. WAA is recommended by the Swedish Forest Agency tocounteract acidification in soil and runoff that may be caused by an intensivebiomass harvesting. The impact of the WAA was studied during 2005-2006.Compared to the control temporarily higher concentrations of K, Ca and SO4 wereobserved in the soil solution of the ashed area. In the stream water the effects of theWAA were easier to distinguish due to higher sampling frequency. The strongesteffect was seen for K, but increases in the stream water were also noted for DOC,Ca, Mg, Si, Cl and malonate. No increase in pH could be statistically verifiedhowever, and overall the initial effects of the WAA seem mild.

  • 340.
    Norström, Sara H
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Vestin, Jenny LK
    Swedish geotechnical institute.
    Bylund, Dan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Lundström, Ulla S
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Influences of dissolved organic carbon on stream water chemistry in two forested catchments in central Sweden2010Inngår i: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 101, nr 1-3, s. 229-241Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stream water chemistry in two headwater streams draining two small, adjacent catchments in Bispgården, central Sweden was studied during the 2003 and 2004 growing seasons. The two catchments closely resemble each other in regard to size, shape and drainage density, with the major difference found in the area of wetland lining the streambeds. The emphasis of the study was to investigate the stream water chemistry of these closely resembling catchments, regarding the quality and quantity of dissolved organic carbon (DOC) and its influence on the concentrations of di- and trivalent cations. The streams showed significant differences in the content and size distribution of DOC and in the distribution of cations between the different size fractions. For both streams the high flow events induced by precipitation influenced the chemistry of the streams through increase of organic matter and its associated cations. Fanbergsbäcken, with relatively low pH and high DOC concentration, had a greater amount of high molecular mass (HMM) DOC to which approximately 75% of Al and Fe and about 50% of Ca and Mg were associated. Gråbergsbäcken, with a higher pH and lower DOC level, had approximately 65% of Al, 40% of Fe and 30% of Ca and Mg associated to its HMM DOC fraction. Sixteen different low molecular mass organic acids were found in the stream water, of which oxalic and lactic acid were present in the highest concentrations.

  • 341.
    Norén, Katarina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Coordination Chemistry of Monocarboxylate and Aminocarboxylate Complexes at the Water/Goethite Interface2007Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis is a summary of five papers with focus on adsorption processes of various monocarboxylates and aminocarboxylates at the water/goethite interface. Interaction of organic acids at the water/mineral interfaces are of importance in biogeochemical processes, since such processes have potential to alter mobility and bioavailability of the acids and metal ions.

    In order to determine the coordination chemistry of acetate, benzoate, cyclohexanecarboxylate, sarcosine, MIDA (methyliminediacetic acid), EDDA (ethylenediamine-N,N’-diacetic acid) and EDTA (ethylenediamine-N,N’-tetraacetic acid) upon adsorption to the goethite (alpha-FeOOH) surface, a combination of quantitative measurements with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized.

    Over the pH range studied here (pH 3- 9) all ligands, except for sarcosine, have been found to form surface complexes with goethite. In general, theses were characterized as outer sphere surface complexes i.e. with no direct interaction with surface Fe(III) metal ions. Furthermore, two types of different outer-sphere complexes were identified, the solvent-surface hydration-separated ion pair, and hydration-shared ion pair. For the monocarboxylate surface complexes distinction between these two could be made. At high pH values the solvent-surface hydration-separated ion pair was the predominating complex, while at low pH the surface complex is stabilized through the formation of strong hydrogen bonds with the goethite surface. However, it was not possible to clearly separate between the two outer-sphere complexes for coordination of the aminocarboxylates with the surface of goethite. Additionally, EDDA also formed an inner-sphere surface complex at high pH values. The EDDA molecule was suggested to coordinate to the surface by forming a five membered ring with an iron at the goethite surface, through the amine and carboxylate groups.

    Contrary to the other ligands studied, EDTA significantly induced dissolution of goethite. Some of the dissolved iron, in the form of the highly stable FeEDTA- solution complex, was indicated to re-adsorb to the mineral surface as a ternary complex. Similar ternary surface complexes were also found in the Ga(III)EDTA/goethite system, and quantitative and spectroscopic studies on adsorption of Ga(III) in presence and absence of EDTA showed that EDTA considerably effects speciation of gallium at goethite surface.

    The collective results in this thesis show that the affinity of these ligands for the surface of goethite is primarily governed by their chemical composition and structure, and especially important are the types, numbers and relative position of functional groups within the molecular structure.

  • 342.
    Nygren, Patrik
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Lundqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Broo, Klas
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Jonsson, Bengt-Harald
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Fundamental Design Principles That Guide Induction of Helix upon Formation of Stable Peptide−Nanoparticle Complexes2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 7, s. 1844-1852Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have shown that it is possible to design a peptide that has a very low helical content when free in solution but that adopts a well-defined helix when interacting with silica nanoparticles. From a systematic variation of the amino acid composition and distribution in designed peptides, it has been shown that the ability to form helical structure upon binding to the silica surface is dominated by two factors. First, the helical content is strongly correlated with the net positive charge on the side of the helix that interacts with the silica, and arginine residues are strongly favored over lysine residues in these positions. The second important factor is to have a high net negative charge on the side of the helix that faces the solution. Apparently, both attractive and repulsive electrostatic forces dominate the induction and stabilization of a bound helix. It is also evident that using amino acids that have high propensity to form helix in solution are also advantageous for the formation of helix on surfaces.

  • 343.
    Obaidur, Rahman
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Erlandsson, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Blom, Elisabeth
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Långström, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Automated synthesis of 18F-labelled analogues of etomidate, vorozole and harmine using commercial synthesizer TRACERLab FXFNManuskript (Annet vitenskapelig)
    Abstract [en]

    18F-Labelled analogues of three biologically interesting compounds, ethyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (ETO), 6-[(S)-(4-chlorophenyl)-(1H)-1,2,4-triazol-1-yl)methyl]-1-methyl-1H-benzotriazole (VOZ) and 7-methoxy-1-methyl-9H-β-carboline (HAR) were synthesized by one-step nucleophilic fluorination. The 18F-labelled products were obtained with 20–30% isolated decay-corrected radiochemical yields and the radiochemical purities were over 99% in all cases. The labelling syntheses were performed using fully automated commercial synthesizer TRACERLab FXFN. The automation of the syntheses of these three promising PET tracers using a commercial synthesizer will make them accessible for clinical applications.       

  • 344.
    Oglęcka, Kamila
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Lundberg, Pontus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Magzoub, Mazin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Eriksson, L. E. Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Langel, Ülo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Gräslund, Astrid
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Relevance of the N-terminal NLS-like sequence for membrane interactions of the Prion protein2007Inngår i: Biochimica et Biophysica Acta. MR. Reviews on Biomembranes, ISSN 0304-4157, E-ISSN 1879-257X, Vol. 1778, nr 1, s. 206-213Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated the nuclear localization-like sequence KKRPKP, corresponding to the residues 23–28 in the mouse prion protein (mPrP), for its membrane perturbation activity, by comparing effects of two mPrP-derived peptides, corresponding to residues 1–28 (mPrPp(1–28)) and 23–50 (mPrPp(23–50)), respectively. In erythrocytes, mPrPp(1–28) induced 60% haemoglobin leakage after 30 min, whereas mPrPp(23–50) had negligible effects. In calcein-entrapping, large unilamellar vesicles (LUVs), similar results were obtained. Cytotoxicity estimated by lactate dehydrogenase leakage from HeLa cells, was found to be 12% for 50 μM mPrPp(1–28), and 1% for 50 μM mPrPp(23–50). Circular dichroism spectra showed structure induction of mPrPp(1–28) in the presence of POPC:POPG (4:1) and POPC LUVs, while mPrPp(23–50) remained a random coil. Membrane translocation studies on live HeLa cells showed mPrPp(1–28) co-localizing with dextran, suggesting fluid-phase endocytosis, whereas mPrPp(23–50) hardly translocated at all. We conclude that the KKRPKP-sequence is not sufficient to cause membrane perturbation or translocation but needs a hydrophobic counterpart.

  • 345.
    Ohgaki, Ryuichi
    et al.
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Teramura, Yuji
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Klinisk immunologi. The University of Tokyo, Department of Bioengineering.
    Hayashi, Daichi
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Quan, Lili
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Okuda, Suguru
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Nagamori, Shushi
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Takai, Madoka
    The University of Tokyo, Department of Bioengineering.
    Kanai, Yoshikatsu
    Osaka University, Graduate School of Medicine, Department of Bio-system Pharmacology.
    Ratiometric fluorescence imaging of cell surface pH by poly(ethylene glycol)-phospholipid conjugated with fluorescein isothiocyanate2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 17484Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Various physiological and pathological processes are accompanied with the alteration of pH at extracellular juxtamembrane region. Accordingly, the methods to analyze the cell surface pH have been demanded in biological and medical sciences. In this study, we have established a novel methodology for cell surface pH imaging using poly(ethylene glycol)-phospholipid (PEG-lipid) as a core structure of ratiometric fluorescent probes. PEG-lipid is a synthetic amphiphilic polymer originally developed for the cell surface modification in transplantation therapy. Via its hydrophobic alkyl chains of the phospholipid moiety, PEG-lipid is, when applied extracellularly, spontaneously inserted into the plasma membrane and retained at the surface of the cells. We have demonstrated that the PEG-lipid conjugated with fluorescein isothiocyanate (FITC-PEG-lipid) can be used as a sensitive and reversible cell-surfacea-nchored pH probe between weakly alkaline and acidic pH with an excellent spatiotemporal resolution. The remarkably simple procedure for cell-surface labeling with FITC-PEG-lipid would also be advantageous when considering its application to high-throughput in vitro assay. This study further indicates that various probes useful for the investigation of juxtamembrane environments could also be developed by using PEG-lipid as the core structure for bio-membrane anchoring.

  • 346.
    Olofsson, Evelina
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Bronopol - ett miljöproblem i Sverige?2008Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    Bronopol (2-brom-2nitropropan-1,3-diol) occurs in many products, for example cosmetics, medicines and industrial water systems. In this thesis Bronopol was investigated to see if it is an environmental problem in Sweden.

    As a starting point two existing analysis methods was used to combine to one. The first one was suited for phenol analysis and the other one for Bronopol analysis. The combined method was optimized as far as possible, although this wasn’t achieved as hoped. The cause of this was due to errors beyond our explanation. Because of this problem the yield couldn’t be determined.

    The water samples were taken from Tekniska Verken in Linköping, Sweden. It was two samples, one incoming and one outgoing sample from the waste water treatment plant. The samples were filtered and then they were passed through SPE columns. The samples were evaporated to dryness with N2. After this the samples were derivatizised with TMS and the following step was GC analysis with EC – detector.

    Bronopol was detected in the incoming water sample.

  • 347.
    Olsson, Gustaf D.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Fundamental Studies of Molecular Interactions in Complete Prepolymerization Mixtures of Molecularly Imprinted Polymers2009Oppgave
    Abstract [en]

    In the present work, molecular dynamics simulations were used to evaluate the molecular interactions in prepolymerization mixtures, as occurring during production of molecularly imprinted polymers. The systems simulated were produced based on earlier studies for reference of results. Four systems were simulated in order to investigate the effect on molecular interactions based upon the choice of porogen (acetonitrile or chloroform) and proton transfers. The systems consisted of phenylalanine anilide as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker and 2,2’-azobis-(2-methylpropionitrile) as radical initiator, with either acetonitrile or chloroform as porogen. Trajectories from the simulations were evaluated through radial distribution function analysis, grid density analysis and hydrogen bond analysis to investigate molecular interactions and complex formations in the simulated complete prepolymerization mixtures. Focus was on functional monomer-template, crosslinker-template and template-template complex formations. The results showed that the porogen influences molecular interactions in complete prepolymerization mixtures. Formation of higher order complexes was confirmed in all of the systems involving all of the investigated molecular species in the prepolymerization mixtures. The results could also confirm the presence of previously observed complexes between functional monomer and template (2:1 and 1:1 stoichiometry) and the prevalence of template dimerization, as well as a high involvement of crosslinker in complex formation.

  • 348.
    Olsson, Jessica
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Enzymtillsats som ersättning för extratillsatt gluten i bröddegar2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    With today’s demand to produce bread varieties at low cost, bread bakeries are looking for alternative methods to achieve cheaper products but with the same qualities.

    There are many approaches that can be used to achieve this, modifying the baking process by using enzymes is one method.

    In bread bakeries, extra gluten is usually added to bread dough to achieve bread with increased volume, improved crumb structure, dough stability, shelf life and circular shape.

    Gluten proteins align to form a thin viscous protein layer called gluten network which contributes to a range of bread characteristics and is therefore difficult to substitute. The raw materials expensiveness, due to a range of price changes, has influenced development of new methods that will substitute the use of extra added gluten.

    The focus of this study is to substitute 50 % of the extra added gluten in a wheat and rye dough (25 respectively 40 g/ kg water) by using enzymes in purpose to strength and stretch the gluten network and get similar results compared to bread baked with extra added gluten.

    Wheat and rye bread were baked with the addition of three different kinds of enzyme (named X, Y and Z), in three concentrations with the purpose to strength the gluten network. After the fermentation and before baking stability test was performed. After baking the bread’s volume, crumb structure and shape were estimated. The results were compared to bread baked with extra added gluten (reference bread). The wheat bread most similar to its reference bread was bread baked with 250 ppm of enzyme addition V.  To stabilize the strengthened gluten network enzyme Z was added. The outcome of this study showed that the combination of enzyme V and Z is able to substitute for 50 % of the extra added gluten in wheat and rye bread.

  • 349.
    Olsson, R T
    et al.
    KTH.
    Azizi Samir, M A S
    Nanocomposites and Bioconcepts s.a.r.l., N170 Tanalt Alhouda (Agadir), .
    Salazar-Alvarez, German
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Belova, L
    KTH.
    Ström, V
    KTH.
    Berglund, L A
    KTH.
    Ikkala, O
    Helsinki University of Technology/Aalto University School of Science and Technology, Molecular Materials, Department of Applied Physics.
    Nogués, J
    Universitat Autònoma de Barcelona.
    Gedde, U W
    KTH.
    Making flexible magnetic aerogels and stiff magnetic nanopaper using cellulose nanofibrils as templates2010Inngår i: Nature Nanotechnology, ISSN 1748-3387, E-ISSN 1748-3395, Vol. 5, s. 584-588Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nanostructured biological materials inspire the creation of materials with tunable mechanical properties. Strong cellulose nanofibrils derived from bacteria or wood can form ductile or tough networks that are suitable as functional materials. Here, we show that freeze-dried bacterial cellulose nanofibril aerogels can be used as templates for making lightweight porous magnetic aerogels, which can be compacted into a stiff magnetic nanopaper. The 20-70-nm-thick cellulose nanofibrils act as templates for the non-agglomerated growth of ferromagnetic cobalt ferrite nanoparticles (diameter, 40-120 nm). Unlike solvent-swollen gels and ferrogels, our magnetic aerogel is dry, lightweight, porous (98%), flexible, and can be actuated by a small household magnet. Moreover, it can absorb water and release it upon compression. Owing to their flexibility, high porosity and surface area, these aerogels are expected to be useful in microfluidics devices and as electronic actuators.

  • 350.
    Olsson, Rickard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Surface reactions on mineral particles controlling the hydrolysis of glucose phosphates2011Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Phosphorus (P) is an essential nutrient. A significant amount of soil P may be in the form of organophosphates. Due to the size of these compounds, hydrolysis is often required before P can be assimilated by organisms. Hydrolysis may be mediated by mineral surfaces, or catalyzed by extra cellular enzymes. Since both organophosphates and enzymes have a strong affinity for environmental particles, a study of the hydrolysis of organophosphates must focus on reactions at the water/particle interface. This thesis is a summary of four papers, discussing the adsorption, desorption, and abiotic and enzymatic hydrolysis of glucose-1-phosphate (G1P) and glucose-6-phosphate (G6P) in aqueous goethite suspensions. A new technique for simultaneous infrared and potentiometric titrations (SIPT) allowed in-situ measurements of the interfacial reactions. It was found that glucose phosphates form pH-dependent inner sphere complexes on goethite, which coordinate in a monodentate fashion, and are stabilized by hydrogen bonding. Desorption involves a change in speciation of the surface complexes, illustrating the difficulty in determining desorption rates for individual complexes. The surface mediated hydrolysis is primarily base catalyzed for G1P, and acid catalyzed for G6P. The difference is partly due to electronic factors, and partly to differences in glucose group/goethite interactions. Considerably more extensive is the hydrolysis catalyzed by an acid phosphatase (AcPase). The rate of the enzymatic hydrolysis are strongly dependent on the glucose phosphate surface coverage, showing that surface properties affect the adsorption mode of enzymes, and thus their catalytic activity. In solution, AcPase showed a greater specificity towards G6P, but this specificity was partly lost after adsorption onto goethite.

45678910 301 - 350 of 488
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf