| 1. |
- Aasa, Mikael, et al.
(author)
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Cost and health outcome of primary percutaneous coronary intervention versus thrombolysis in acute ST-segment elevation myocardial infarction-Results of the Swedish Early Decision reperfusion Study (SWEDES) trial.
- 2010
-
In: American heart journal. - : Elsevier BV. - 1097-6744 .- 0002-8703. ; 160:2, s. 322-8
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Journal article (peer-reviewed)abstract
- BACKGROUND: In ST-elevation myocardial infarction, primary percutaneous coronary intervention (PCI) has a superior clinical outcome, but it may increase costs in comparison to thrombolysis. The aim of the study was to compare costs, clinical outcome, and quality-adjusted survival between primary PCI and thrombolysis. METHODS: Patients with ST-elevation myocardial infarction were randomized to primary PCI with adjunctive enoxaparin and abciximab (n = 101), or to enoxaparin followed by reteplase (n = 104). Data on the use of health care resources, work loss, and health-related quality of life were collected during a 1-year period. Cost-effectiveness was determined by comparing costs and quality-adjusted survival. The joint distribution of incremental costs and quality-adjusted survival was analyzed using a nonparametric bootstrap approach. RESULTS: Clinical outcome did not differ significantly between the groups. Compared with the group treated with thrombolysis, the cost of interventions was higher in the PCI-treated group ($4,602 vs $3,807; P = .047), as well as the cost of drugs ($1,309 vs $1,202; P = .001), whereas the cost of hospitalization was lower ($7,344 vs $9,278; P = .025). The cost of investigations, outpatient care, and loss of production did not differ significantly between the 2 treatment arms. Total cost and quality-adjusted survival were $25,315 and 0.759 vs $27,819 and 0.728 (both not significant) for the primary PCI and thrombolysis groups, respectively. Based on the 1-year follow-up, bootstrap analysis revealed that in 80%, 88%, and 89% of the replications, the cost per health outcome gained for PCI will be <$0, $50,000, and $100,000 respectively. CONCLUSION: In a 1-year perspective, there was a tendency toward lower costs and better health outcome after primary PCI, resulting in costs for PCI in comparison to thrombolysis that will be below the conventional threshold for cost-effectiveness in 88% of bootstrap replications.
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| 2. |
- Arup, Ulf, et al.
(author)
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Belonia nidarosiensis funnen i Sverige
- 2013
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In: Lavbulletinen. - 1651-6435. ; 2013:2, s. 44-48
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Journal article (peer-reviewed)abstract
- Redan för några år sedan hittade Mikael Hagström och Jan Henriksson B. nidarosiensis på Gotland, men av flera anledningar har det tagit lite tid att få klarhet vad det var för art. Nedan beskriver de tillsammans med Ulf Arup hela historien om fynden på Gotland.
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| 3. |
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| 4. |
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| 5. |
- Azhar, Shoaib, et al.
(author)
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Extraction of polymers from enzyme-treated softwood
- 2011
-
In: BioResources. - 1930-2126. ; 6:4, s. 4606-4614
-
Journal article (peer-reviewed)abstract
- In a biorefinery context it is an advantage to fractionate and extract different wood components in a relatively pure form. However, one major obstacle for efficient extraction of wood polymers (lignin, polysaccharides etc.) is the covalent lignin-polysaccharide networks present in lignified cell walls. Enzymatic catalysis might be a useful tool for a controlled degradation of these networks, thereby enhancing the extraction of high molecular weight polymers. In this work, a methanol-alkali mixture was used to extract two different wood samples treated with endoxylanase and gammanase, respectively. Wood chips were pretreated with alkali prior to enzymatic treatment to enhance the cell-wall accessibility to enzymes. Extractions were also carried out on non-enzyme-treated samples to evaluate the enzymatic effects. Results showed that the enzymatic treatment increased the extraction yield, with gammanase as the more efficient of the two enzymes. Furthermore, polymers extracted from xylanase-treated wood had a higher degree of polymerization than the reference.
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| 6. |
- Brynolfsson, Patrik, et al.
(author)
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ADC texture-An imaging biomarker for high-grade glioma?
- 2014
-
In: Medical physics (Lancaster). - : Wiley. - 0094-2405. ; 41:10, s. 101903-
-
Journal article (peer-reviewed)abstract
- Purpose:Survival for high-grade gliomas is poor, at least partly explained by intratumoral heterogeneity contributing to treatment resistance. Radiological evaluation of treatment response is in most cases limited to assessment of tumor size months after the initiation of therapy. Diffusion-weighted magnetic resonance imaging (MRI) and its estimate of the apparent diffusion coefficient (ADC) has been widely investigated, as it reflects tumor cellularity and proliferation. The aim of this study was to investigate texture analysis of ADC images in conjunction with multivariate image analysis as a means for identification of pretreatment imaging biomarkers.Methods:Twenty-three consecutive high-grade glioma patients were treated with radiotherapy (2 Gy/60 Gy) with concomitant and adjuvant temozolomide. ADC maps and T1-weighted anatomical images with and without contrast enhancement were collected prior to treatment, and (residual) tumor contrast enhancement was delineated. A gray-level co-occurrence matrix analysis was performed on the ADC maps in a cuboid encapsulating the tumor in coronal, sagittal, and transversal planes, giving a total of 60 textural descriptors for each tumor. In addition, similar examinations and analyses were performed at day 1, week 2, and week 6 into treatment. Principal component analysis (PCA) was applied to reduce dimensionality of the data, and the five largest components (scores) were used in subsequent analyses. MRI assessment three months after completion of radiochemotherapy was used for classifying tumor progression or regression.Results:The score scatter plots revealed that the first, third, and fifth components of the pretreatment examinations exhibited a pattern that strongly correlated to survival. Two groups could be identified: one with a median survival after diagnosis of 1099 days and one with 345 days, p = 0.0001.Conclusions:By combining PCA and texture analysis, ADC texture characteristics were identified, which seems to hold pretreatment prognostic information, independent of known prognostic factors such as age, stage, and surgical procedure. These findings encourage further studies with a larger patient cohort. (C) 2014 Author(s).
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| 7. |
- Gad, Helge, et al.
(author)
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MTH1 inhibition eradicates cancer by preventing sanitation of the dNTP pool
- 2014
-
In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 508:7495, s. 215-221
-
Journal article (peer-reviewed)abstract
- Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death. We validate MTH1 as an anticancer target in vivo and describe small molecules TH287 and TH588 as first-in-class nudix hydrolase family inhibitors that potently and selectively engage and inhibit the MTH1 protein in cells. Protein co-crystal structures demonstrate that the inhibitors bindin the active site of MTH1. The inhibitors cause incorporation of oxidized dNTPs in cancer cells, leading to DNA damage, cytotoxicity and therapeutic responses in patient-derived mouse xenografts. This study exemplifies the non-oncogene addiction concept for anticancer treatment and validates MTH1 as being cancer phenotypic lethal.
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| 8. |
- Helander, Mikaela, et al.
(author)
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Fractionation of Technical Lignin: Molecular Mass and pH Effects
- 2013
-
In: BioResources. - : BioResources. - 1930-2126 .- 1930-2126. ; 8:2, s. 2270-2282
-
Journal article (peer-reviewed)abstract
- Today, lignin from kraft pulping is used mainly as fuel, with only very small amounts being used as raw material for chemicals and materials. This work focuses on using a convenient method for separating large amounts of low molecular weight lignin from the kraft process. Low molecular weight lignin contains larger amounts of phenolic structural units, which are possible modification sites and can be used as antioxidants. Moreover, a product that has reduced polydispersity, low molecular weight, and purified lignin could be a potential material for new applications. The studied process for separating lignin from weak black liquor used a membrane with a cut-off of 1000 Da. During precipitation of the 1000 Da permeate, it is necessary to prevent formation of fairly large, rigid particles/agglomerates of lignin by keeping the temperature low. To improve the dead-end filtration, higher ionic strength is needed for the weak black liquor. Additionally, reducing the end pH will cause more material to precipitate. More sulfur was found in the low molecular weight lignin and at lower precipitation pH, indicating that most sulfur left in the lignin samples might be bound to low molecular weight lignin.
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| 9. |
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| 10. |
- Henriksson, Gunnar, 1965-, et al.
(author)
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Lignin Utilization
- 2010
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In: Thermochemical conversion of biomass to liquid fuels and chemicals. - : RSC Publishing. - 9781849732260 ; , s. 222-262
-
Book chapter (peer-reviewed)abstract
- Lignin is one of the most abundant biopolymers on Earth, carrying out important biological roles in vascular plants. It has somewhat higher energy content than polysaccharides, but has a complex and heterogeneous structure including covalent bonds to polysaccharides. The partly random structure of lignin is explained by the fact that it is created by an uncatalyzed radical polymerization. Lignin is obtained as a by-product of various types of technical processes based on biomass, of which chemical pulping of wood is the most important. These technical lignins have structures that differ from native lignin. Sulphite pulping of wood generates a water soluble lignin derivate, which among other things, is used as a dispersing agent and dust binder. Kraft pulping generates a lignin that is insoluble at neutral pH, which today is mainly burned for heat generation in the chemical recovery system of the kraft pulp mill. Recently, efficient methods have been developed for the preparation of lignin from the process liquids, for use in energy generation or other applications. Conversion of technical lignin to liquid fuels for use in combustion engines is an interesting possibility that represents a technical challenge. This chapter reviews the structure and biopolymerisation of lignin, reactions of lignin during technical processes, and different applications of technical lignins.
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| 11. |
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| 12. |
- Henriksson, Gunnar, et al.
(author)
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Ways to tailor-make xylan for kraft pulping
- 2011
-
In: Proceedings 16th International Symposium on Wood, Fiber and Pulping Chemistry, ISWFPC. - : China Light Industry Press. ; , s. 596-599
-
Conference paper (peer-reviewed)abstract
- Genetic manipulation of trees in order to produce raw material with different chemical composition, which will perform better in pulping and bleaching, has gained large interest the last decade. Most efforts have been on increasing cellulose content, and modifying the lignin structure so that the pulping will be more efficient. Less interest has been focused on the hemicellulose structures, although many important chemical reactions occur on hemicelluloses during kraft pulping. For instance, hexenuronic acid is formed from 4-O-methyl glucuronic acid, a side group on xylan. This structure is a main contributor to the kappa number in the unbleached pulp, especially in hardwoods, and requires relatively strong bleaching agents for efficient removal. Remaining hexenuronic acid in the bleached pulp may furthermore cause post yellowing. In model experiments, we have simulated kraft cooking, and shown that hexenuronic acid is formed to a much lower degree from unmethylated glucuronic acid, than from 4-O-methylglucuronic acid. A tree without methyl groups on its glucuronic acid residues on xylan, is therefore expected to be pulped to a much lower kappa number, and to be easy to bleach to high brightness stability. According to a literature study, the possibilities to make such a tree by genetically manipulation appear to be promising. There might also be other ways, in which hemicelluloses structure can be manipulated.
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| 13. |
- Henriksson, Sara, et al.
(author)
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Development of an in situ assay for simultaneous detection of the genomic and replicative form of PCV2 using padlock probes and rolling circle amplification
- 2011
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In: Virology Journal. - 1743-422X. ; 8, s. 37-
-
Journal article (peer-reviewed)abstract
- Background: In this study we utilized padlock probes and rolling circle amplification as a mean to detect and study the replication of porcine circovirus type 2 (PCV2) in cultured cells and in infected tissue. Porcine circovirus type 2 is a single-stranded circular DNA virus associated with several severe diseases, porcine circovirus diseases (PCVD) in pigs, such as postweaning multisystemic wasting syndrome. The exact reason and mechanisms behind the trigger of PCV2 replication that is associated with these diseases is not well-known. The virus replicates with rolling circle replication and thus also exists as a double-stranded replicative form. Results: By applying padlock probes and rolling circle amplification we could not only visualise the viral genome but also discriminate between the genomic and the replicative strand in situ. The genomic strand existed in higher numbers than the replicative strand. The virus accumulated in certain nuclei but also spread into the cytoplasm of cells in the surrounding tissue. In cultured cells the average number of signals increased with time after infection. Conclusions: We have developed a method for detection of both strands of PCV2 in situ that can be useful for studies of replication and in situ detection of PCV2 as well as of DNA viruses in general.
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| 14. |
- Jedvert, Kerstin, 1984, et al.
(author)
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Mild steam explosion: A way to activate wood for enzymatic treatment, chemical pulping and biorefinery processes
- 2012
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In: Nordic Pulp and Paper Research Journal. - 2000-0669 .- 0283-2631. ; 27:5, s. 828-835
-
Journal article (peer-reviewed)abstract
- Industrially chipped wood chips of Norway spruce (Picea abies) were subjected to mild steam explosion (115 - 160 degrees C) in a small-scale steam explosion reactor. This was followed by kraft cooking or extraction in alkali at 130 degrees C for two hours, or by an enzymatic treatment with a culture filtrate in order to investigate the efficiency of the process in opening wood structure. The results demonstrated that mild explosion has an effect on opening wood structure, shown by increased release of glucomannans during alkaline extraction and faster delignification in kraft cooks for steam-exploded samples. The effect was also shown by analysis of the released reducing sugars of enzymatic treated wood chips, which showed that the wood structure became accessible for enzymes even at very modest mild steam explosion conditions. This was not observed in untreated wood chips, used as reference. The enzyme activity increased with increased temperature during mild steam explosion, and the effect did not seem to be linear. The mechanical effect of steam explosion seems to be of great importance at lower temperatures, and both chemical and mechanical effects are important at higher steam explosion temperatures. Samples for enzymatic treatment were taken both from the edges of wood chips as well as from the middle part of the chips, and the effect of steam explosion was somewhat greater in samples from the middle parts.
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| 15. |
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| 16. |
- Karlsson, Terese, 1979-
(author)
-
The expression and molecular functions of LRIG proteins in cancer and psoriasis
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- The leucine-rich repeats and immunoglobulin-like domains (LRIG) family consists of three integral membrane proteins that are important in human cancer. LRIG1 is a negative regulator of growth factor signaling. Its expression is associated with longer survival in several cancer types, and the gene has been shown to function as a tumor suppressor. The roles of LRIG2 and LRIG3 are less well known. The aim of this thesis was to improve our understanding of the expression and function of the LRIG protein family in psoriasis and cancer.To investigate their expression in psoriasis, the mRNA levels and subcellular localization of the LRIG proteins were analyzed and compared between normal and psoriatic human skin. There were no differences in the LRIG mRNA levels between psoriatic and normal skin samples. However, the subcellular localization of all three LRIG proteins differed between psoriatic and normal skin.To study the physiological and molecular functions of Lrig2, we generated Lrig2E12-/- mice. These mice were viable and born at a Mendelian rate, but Lrig2E12-/- mice had an increased rate of spontaneous mortality and a transient reduction in growth rate compared to Lrig2 wild-type (wt) mice. In an orthotopic platelet-derived growth factor (PDGF)B-driven brain tumor mouse model, we studied the effect of Lrig2 on gliomagenesis. All Lrig2 wt mice developed tumors; 82% developed grade II/III tumors, and 18% developed grade IV tumors. Only 77% of the Lrig2E12-/- mice developed tumors, and they were all grade II/III tumors. Thus, Lrig2 increased the incidence and malignancy rates of PDGFB-driven gliomas. We then analyzed the effect of Lrig2 on Pdgf receptor (Pdgfr) signaling. Lrig2 had no effect on Pdgfr steady-state levels, the starvation-induced up-regulation of Pdgfrs, the phosphorylation of Pdgfrs, primary cilium formation or the PDGFBB-induced phosphorylation of Akt or Erk1/2. However, the kinetics of induction of the immediate-early genes Fos and Egr2 were altered, resulting in a more rapid induction in Lrig2E12-/- cells.We then analyzed the clinical and biological importance of LRIG1 in lung cancer. In a human lung cancer tissue micro-array (TMA), LRIG1 expression was found to be an independent positive prognostic factor for adenocarcinoma. To study the importance of Lrig1 regarding lung cancer development in vivo, we used an inducible EGFRL858R-driven mouse lung cancer model. The mice developed diffuse lung adenocarcinoma, and the tumor burden was greater in Lrig1-/- mice than in Lrig1+/+ mice (p = 0.025) at 60 days. The human lung cancer cell line H1975, with either normal or Tet-induced expression of LRIG1, was injected into the flanks of Balb/cA nude mice. Tumors formed by LRIG1-overexpressing cells were smaller than those formed by parental cells, further indicating that LRIG1 is important during lung tumor formation or growth. In vitro, LRIG1 suppressed the proliferation of H1975 cells and down-regulated the phosphorylation of MET and RET.To investigate the molecular functions of LRIG proteins further, we performed a yeast two-hybrid (YTH) screen using a peptide from the cytosolic tail of LRIG3 as bait. This screen identified LMO7 and LIMCH1 as prominent interaction partners for LRIG3. Proximity ligation assays showed that LMO7 interacted with all of the LRIG proteins at endogenous expression levels. LMO7 and LIMCH1 were expressed in all human tissues analyzed. Their expression was dramatically decreased in lung cancer compared to normal lung tissue. The expression of LMO7 was analyzed in a human lung cancer TMA. LMO7 was expressed in respiratory epithelial cells in normal lungs. However, LMO7 was only expressed in a quarter of the lung tumors. LMO7 expression was found to be an independent negative prognostic factor for lung cancer.In summary, we found that the LRIG proteins were redistributed in psoriatic skin. In a mouse glioma model, Lrig2 promoted oligodendroglioma genesis. LRIG1 was an independent positive prognostic factor in human lung cancer. Lrig1 ablation increased the tumor size in an EGFRL858R-driven lung cancer mouse model. LRIG1 expression decreased the tumor growth of human lung cancer cells in a xenograft mouse model. LMO7 interacted with all three LRIG proteins and was an independent negative prognostic factor in human lung cancer. These data demonstrate the importance of LRIG proteins in human disease.
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| 17. |
- Li, Jiebing, et al.
(author)
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The methoxy group of beta-O-methyl glucuronic acid is central for the formation of hexenuronic acid during kraft pulping
- 2011
-
In: O Papel. - 0031-1057. ; 72:1, s. 54-65
-
Journal article (peer-reviewed)abstract
- Hexenuronic acid is created from 4-O-methyl gluc-uronic acid – a side chain group in xylan, and one of the most important hemicelluloses in both hardwood and softwood - during alkaline conditions, such as kraft pulping. Especially in hardwood kraft pulp, hexenuronic acid corresponds to a large part of the kappa number, and the presence of this component in bleached pulp causes post yellowing. In this work it is shown that glucuronic acid that lacks a methoxy group on the 4-carbon does not form hexenuronic acid under alkaline condition to the same extent as 4-O-methylglucuronic acid. This opens up novel strategies for genetic modification of the hemicellulose structures in wood cultivated for kraft pulping.
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| 18. |
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| 19. |
- Svensson, Nils-Olof
(author)
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Rapport rörande havsmiljö och pollenanalytisk vegetationshistoria : undersökningsresultat från yta 7 Ysane socken, Sölvesborgs kommun, Blekinge län
- 2014
-
In: Yta 7. - Karlskrona : Blekinge Museum.
-
Book chapter (other academic/artistic)abstract
- Denna undersökning ingår som en del i projektet Särskildundersökning av ny vägsträckning av väg E22, sträckanSölve–Stensnäs, Sölvesborgs och Karlshamns kommuner,Blekinge län (Länsstyrelsen i Blekinge län, Dnr 431-2502-10). Undersökningen genomfördes som en särskild utredning,steg 2, under 2011, inom fastigheterna Norje 67:1, 4:10,9:24, 6:35, 6:14, 10:19, 85:3, 10:27, 7:27, 70:1, 48:3, 86:1, Ysanesocken, Sölvesborgs kommun.Den särskilda utredning, steg 2, av Yta 7 omfattade enca 40–50 m bred och ca 1 580 m lång del av vägområdet förnya E22 och passerade ett flertal fastigheter i anslutning tillNorje by i Ysane socken. Undersökningsområdet gränsade isöder mot undersökningslokalen Norje Sunnansund, YsaneRAÄ 80, 44 m fl) och i norr mot lokalen Norje Nordansund(Ysane RAÄ 47) (figur 3 i rapporten). Sett till polleninnehåll i relation till den regionala vegetationsutvecklingen är de två undersökta pollenprofilerna något olika till sin ålder. Profilen åt norr i schakt 1 saknar helt pol len av lind (Tilia) vilket ju ären karaktärsart i den atlantiska skogen i regionen. Det undre provet i sektionen har så pass låga frekvenser av al att provet troligen representerar en ti- dig fas i alens etablering i landskapet. Pollenanalytiskt kan det undre provet därför knytas till övergången mellan tidig- boreal och senboreal pollenzon, och det övre provet faller i senboreal pollenzon. Sektionen åt syd har däremot i båda sina prov lindpol- len i frekvens på runt 1,5. Alens frekvens är hög nog att indikera att den är väl etablerad i området. Pollenanalytiskt faller proverna därför troligast i slutet av senboreal pollenzon. Av detta kan dras den slutsatsen att nedre delen av sedi- menten i sektionen åt norr avlagrats före det att sedimentationen i sektionen åt syd påbörjats. Dateringarna från respektive sektion stödjer även detta och även om de är mycket likartade är åldern för PM229 provet uppemot 100–200 år yngre än dateringen från PM230. Ur sedimentstratigrafisk synvinkel är dateringarna något anmärkningsvärda, den absoluta nivån är likartad, -1,03 respektive -1,13 m, och man skulle kunna förvänta sig att sandlagret skulle ha en enhetlig ålder på de båda närliggande platserna. Så är tydligen inte fallet, vilket rimligen bör knytas till olika exponeringsgradför strandprocesser för de båda sektionerna. Bottensekvensen av de båda lagerföljderna med ett sand- igt gruslager som erosivt vilar på en glacial lera och därovan gyttja tolkas troligen som en transgressionssekvens, alltså stigande vattennivå. Möjligen kan denna bero på hydrologiska förändringar i den forna Vesaninsjön men troligast är vattenståndshöjningen knuten till en transgression i Östersjön som nått in i Vesanbassängen. De höga tallpollenfrekvenser som förekom i proven, framförallt i de från sektionen mot norr, innebär vid denna tid en klar indikation på en strandnära miljö i ett större vat- tenområde, här antingen den forna Vesaninsjön, eller kanske troligare just i inledningsfasen av Östersjöns transgression in i Vesan. Höga tallpollenfrekvenser i en sådan miljö är typ-n och sedan drivit in i strandzonen där så småningom pollenkornen brutits ner så pass att de sjunkit och inlagrats i strandnära sediment. Mikroskopiska kolpartiklar förekom i anmärkningsvärt höga frekvenserna (18–80 ) för att vara prover som inte är knutna till boplatsytor. Förklaringen kan vara att kolpartiklar vattentransporterats till platsen med processer i strandzonen. Källan kan vara en boplatsyta som eroderats av vågorna i närområdet, men naturligt ursprung från kol äldre skogsbränder eller kanske en drivvedsansamling som fattat eld är ju tänkbar. Vattenmiljön har ändrats något, vilket visar sig i lägre frekvenser av den sötvattenlevande Pediastrum-algen i det yngsta provet PM231, än i proven från sandlagen i botten. Vad som ändrat sig i vattenmiljön är svårt att visa utan dia-toméanalys men det kan tänkas bero på ökad salthalt.
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| 20. |
- Tavast, Daniel, et al.
(author)
-
Selectiveness and efficiency of combined peracetic acid and chlorine dioxide bleaching stage for kraft pulp in removing hexeuronic acid
- 2011
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In: Cellulose Chemistry and Technology. - 0576-9787. ; 45:1-2, s. 89-95
-
Journal article (peer-reviewed)abstract
- Combined peracetic acid and chlorine dioxide bleaching stages of unbleached and oxygen delignified hardwood and softwood kraft pulps were compared with conventional chlorine dioxide and peracetic acid stages as to kappa number and viscosity reduction, selectivity and reduction of hexenuronic acid content. The combined stages were more efficient in kappa number reduction than those with only chlorine dioxide. Part of the increased kappa number reduction was due to an improved degradation of hexenuronic acid. The stages where chlorine dioxide was added before the peracetic acid (DT) showed a higher selectivity than those in which the chemicals were added simultaneously (D+T); in turn, the latter were more efficient than the "pure" chlorine dioxide (D, D-0) and peracetic acid stages (T). However, peracetic acid and chlorine dioxide seemed to react with each other, leading to the degradation of both bleaching chemicals. The mechanisms and practical implementation of these bleaching sequences are discussed.
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| 21. |
- Virtanen, Anders, et al.
(author)
-
Poly(A)-specific ribonuclease (PARN) : An allosterically regulated, processive and mRNA cap-interacting deadenylase
- 2013
-
In: Critical reviews in biochemistry and molecular biology. - : Informa UK Limited. - 1040-9238 .- 1549-7798. ; 48:2, s. 192-209
-
Research review (peer-reviewed)abstract
- Deadenylation of eukaryotic mRNA is a mechanism critical for mRNA function by influencing mRNA turnover and efficiency of protein synthesis. Here, we review poly(A)-specific ribonuclease (PARN), which is one of the biochemically best characterized deadenylases. PARN is unique among the currently known eukaryotic poly(A) degrading nucleases, being the only deadenylase that has the capacity to directly interact during poly(A) hydrolysis with both the m 7 G-cap structure and the poly(A) tail of the mRNA. In short, PARN is a divalent metal-ion dependent poly(A)-specific, processive and cap-interacting 3'-5' exoribonuclease that efficiently degrades poly(A) tails of eukaryotic mRNAs. We discuss in detail the mechanisms of its substrate recognition, catalysis, allostery and processive mode of action. On the basis of biochemical and structural evidence, we present and discuss a working model for PARN action. Models of regulation of PARN activity by trans-acting factors are discussed as well as the physiological relevance of PARN.
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| 22. |
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| 23. |
- Wang, Yan, et al.
(author)
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Increased Degradability of Cellulose by Dissolution in Cold Alkali
- 2014
-
In: BioResources. - : BioResources. - 1930-2126. ; 9:4, s. 7566-7578
-
Journal article (peer-reviewed)abstract
- To enhance the degradability of cellulosic materials for further industrial purposes, different qualities of cellulose were dissolved in cold sodium hydroxide solution and precipitated by lowering the pH with sulfuric acid. The precipitated cellulose was subjected to acidic and enzymatic hydrolysis. The results showed that the precipitated cellulose degraded considerably faster both with enzymes and acid relative to the untreated controls. Important pretreatment parameters that can influence the degradability of the pretreated cellulosic materials were found to include temperature and concentration of the cellulose in NaOH solution. Increasing amounts of cellulose were hydrolysed with decreasing pretreatment temperature; the degradability of the pretreated cellulose increased with decreasing cellulose concentration. The degree of polymerization (DP) also can influence the pretreatment efficiency. Diluted sulfuric acid was able to decrease the DP and enhance the effect of dissolution and precipitation. The results showed that the lower DP of cellulosic materials caused an increase of degradability for the NaOH pretreated samples compared to untreated samples. The NaOH pretreatment was more effective for shorter chain cellulose.
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| 24. |
- Wang, Yan, et al.
(author)
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Mild alkaline treatment activates spruce wood for enzymatic processing : A possible stage in bio-refinery processes
- 2011
-
In: BioResources. - 1930-2126. ; 6:3, s. 2425-2434
-
Journal article (peer-reviewed)abstract
- The structure of wood is so compact that enzymes are too large to penetrate into the structure and thereby attack the wood components for modifications that can be valuable for various purposes. Here we present a pretreatment method based on traditional kraft pulping, which opens the wood structure, so that enzymes are able to attack the wood components. To study this kind of chemical pretreatment, spruce wood samples were treated at similar conditions used in kraft cooking at varying intensities (H-factors). To verify if the structure was "opened" for enzymes, the pretreated wood samples were incubated with a cellulolytic culture filtrate, and the released reducing sugar concentration after the enzymatic hydrolysis was measured. The results indicated that un-pretreated wood fibers could not be attacked by the enzymes, but already relatively mild pretreatment was sufficient for letting the culture filtrate attack wood polysaccharides, and more intensive treatments opened the structure further. The mildest treatments did not cause any significant yield losses of lignin (Klason lignin). Some galactoglucomannans were however lost during the pretreatments. The mechanisms behind the effect and the technical significance of the method are discussed.
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| 25. |
- Wang, Yan
(author)
-
Pretreatment and Enzymatic Treatment of Spruce : A functional designed wood components separation for a future biorefinery
- 2014
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Doctoral thesis (other academic/artistic)abstract
- The three main components of wood, namely, cellulose, hemicellulose, and lignin, can be used in various areas. However, since lignin covalently crosslinks with wood polysaccharides creating networks that is an obstacle for extraction, direct extraction of different wood components in high yield is not an easy matter. One potential approach to overcome such obstacles is to treat the wood with specific enzymes that degrade the networks by specific catalysis. However, the structure of wood is so compact that the penetration of the wood fibers by large enzyme molecules is hindered. Thus, the pretreatment of wood prior to the application of enzymes is necessary, for “opening” the structure.One pretreatment method that was performed in this thesis is based on kraft pulping, which is a well-established and industrialized technique. For untreated wood, the wood fibers cannot be attacked by the enzymes. A relatively mild pretreatment was sufficient for wood polysaccharides hydrolyzed by a culture filtrate. A methanol-alkali mixture extraction was subsequently applied to the samples that were pretreated with two types of hemicellulases, Gamanase and Pulpzyme HC, respectively. The extraction yield increased after enzymatic treatment, and the polymers that were extracted from monocomponent enzyme-treated wood had a higher degree of polymerization. Experiments with in vitro prepared lignin polysaccharide networks suggested that the increased extraction was due to the enzymatic untying. However, the relatively large loss of hemicellulose, particularly including (galacto)glucomannan (GGM), represents a problem with this technique. To improve the carbohydrate yield, sodium borohydride (NaBH4), polysulfide and anthraquinone were used, which increased the yields from 76.6% to 89.6%, 81.3% and 80.0%, respectively, after extended impregnation (EI). The additives also increased the extraction yield from approximately 9 to 12% w/w wood. Gamanase treatment prior to the extraction increased the extraction yield to 14% w/w wood.Sodium dithionite (Na2S2O4) is an alternative reducing agent for the preservation of hemicelluloses because it is less expensive than metal hydrides and only contains sodium and sulfur, which will not introduce new elements to the recovery system. Moreover, Na2S2O4has the potential to be generated from black liquor. Na2S2O4 has some preservation effect on hemicelluloses, and the presence of Na2S2O4 also contributed to delignification. The extraction yield increased to approximately 15% w/w wood. Furthermore, Na2S2O4 has been applied in the kraft pulping process of spruce. The yield and viscosity increased, while the Klason lignin content and kappa number decreased, which represents a beneficial characteristic for kraft pulp. The brightness and tensile strength of the resulting sheets also improved. However, the direct addition of Na2S2O4 to white liquor led to greater reject content. This problem was solved by pre-impregnation with Na2S2O4 and/or mild steam explosion (STEX) prior to the kraft pulping process. Following Na2S2O4 pre-impregnation and mild STEX, the obtained kraft pulp had substantially better properties compared with the properties exhibited after direct addition of Na2S2O4 to the white liquor.The wood structure opening efficiency of mild STEX alone was also tested. The accessibility of the wood structure to enzymes was obtained even at very modest STEX conditions, according to a reducing sugar analysis, and was not observed in untreated wood chips, which were used as a reference. The mechanical effect of STEX appears to be of great importance at lower temperatures, and both chemical and mechanical effects occur at higher STEX temperatures.
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| 26. |
- Wibom, Carl, 1977-, et al.
(author)
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Vandetanib alters the protein pattern in malignant glioma and normal brain in the BT4C rat glioma model
- 2010
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In: International Journal of Cancer. - : Spandidos Publications. - 0020-7136 .- 1097-0215 .- 1019-6439 .- 1791-2423. ; 37:4, s. 879-890
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Journal article (peer-reviewed)abstract
- The treatment of glioblastoma is unsatisfactory. Improved understanding of the biological effects of treatment, together with development of new tools to predict outcome of the initiated treatment are therefore of great need. Vandetanib (ZD6474) is mainly a vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) receptor tyrosine kinase inhibitor. This study investigated the pattern of protein expression in brain tumor and normal brain tissue, following treatment with vandetanib in a rat glioma model. BT4C-cells were stereotactically implanted into the brain of BD IX rats. The rats were divided into three different experiments. The treatment schedule for experiments one and two consisted of daily, oral doses of vandetanib from day 6 until day 12 or 20 after implantation, respectively. In the third experiment, each animal received a single dose of vandetanib on day 19 after implantation and was then sacrificed 2, 8 or 24 h thereafter. The protein expression profiles were analyzed by SELDI-TOF-MS and evaluated with multivariate statistical methods. Following treatment with vandetanib, we found significantly altered protein expression pattern in malignant glioma and normal brain. Analyzing protein spectra is an interesting option to assess biological effects induced in brain tissue by signal transduction inhibitors such as vandetanib.
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| 27. |
- Wichardt, Emma, et al.
(author)
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Rhabdomyolysis/myoglobinemia and NSAID during 48-hours ultra-endurance exercise (adventure racing)
- 2011
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In: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 111:7, s. 1541-1544
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Journal article (peer-reviewed)abstract
- Purpose: To determine if rhabdomyolysis with myoglobinemia exists during a 48+ hour adventure race and if there is a correlation with NSAID use, race time and perceived pain or exertion. Method: Blood samples for analyses of myoglobin (Mb) were collected, and perception of exertion and pain registered on the Borg-RPE and CR scales, from 20 subjects (3 female, 17 male) Pre, Mid and Post race. Subjects were asked about NSAID use at each sampling and within 12 hours pre race. Result: A significant rise in Mb was observed throughout the race, with the NSAID group (n=6) having significantly lower Mb-Post than the no-NSAID group (n=14). High Mb-Pre and Post correlated to shorter race time and high Mb-Pre to lower Pain-Post. Race time also correlated to NSAID use, with the NSAID group having significantly longer race time than the no-NSAID group. Conclusion: Rhabdomyolysis with myoglobinemia, which might be reduced with NSAID use, exists during a 48+ hour adventure race. Indications that high Mb-levels correlate with shorter race time and less pain, and the reasons for the NSAID groups longer race time, need further investigation.
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| 28. |
- Zhu, Hongli, et al.
(author)
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A novel nano cellulose preparation method and size fraction by cross flow ultra- filtration
- 2012
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In: Current organic chemistry. - : Bentham Science Publishers Ltd.. - 1385-2728 .- 1875-5348. ; :16, s. 1871-1875
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Journal article (peer-reviewed)abstract
- A novel energy-efficient method called nanopulping (patent pending) to produce nanocellulose from chemical pulp, and a novel cross-flow ultra-filtration method to separate nanofibrils fractions of different size were applied in this study. Pretreatment with endoglucanase or 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation seems to enhance the nanopulping process. Results were evaluated with atomic force microscope and ultrafiltration. The nanopulping produced a relatively inhomogeneous material with larger particles/ fibers in addition to nanofibers. However, by ultrafiltration of the material it was possible to obtain more homogeneous material in different dimensions with methods industrially acceptable.
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| 29. |
- Zhu, Hongli, et al.
(author)
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Technical soda lignin dissolved in urea as an environmental friendly binder in wood fiberboard
- 2014
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In: Journal of Adhesion Science and Technology. - : Informa UK Limited. - 0169-4243 .- 1568-5616. ; 28:5, s. 490-498
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Journal article (peer-reviewed)abstract
- The application of lignin as binder in wood composite panel is not only environmentally friendly but also commercially attractive. The dissolving of technical soda lignin is the most premier challenge in its application. In this study, the effect of different key factors on soda lignin solubility in urea was investigated. The maximum solubility of 60.16g/L was obtained under the temperature 70 degrees C, urea concentration 8M, lignin content 7%, and pH 8.8. Then, different kinds of wood fiber material were mixed with the dissolved lignin solution to make fiber board separately. The results showed that the lignin can enhance the tensile strength of particleboard and can be used as a binder in wood material, but the strength will be different with different materials. The optimal tensile strength obtained was 44.63MPa with the sample made from oriented cotton linter sheet.
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