| 1. |
- Nordmark, Gunnel, et al.
(författare)
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Association of EBF1, FAM167A(C8orf13)-BLK and TNFSF4 gene variants with primary Sjögren's syndrome
- 2011
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 12:2, s. 100-109
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Tidskriftsartikel (refereegranskat)abstract
- We performed a candidate gene association study in 540 patients with primary Sjögren's Syndrome (SS) from Sweden (n=344) and Norway (n=196) and 532 controls (n=319 Swedish, n=213 Norwegian). A total of 1139 single-nucleotide polymorphisms (SNPs) in 84 genes were analyzed. In the meta-analysis of the Swedish and Norwegian cohorts, we found high signals for association between primary SS and SNPs in three gene loci, not previously associated with primary SS. These are the early B-cell factor 1 (EBF1) gene, P=9.9 × 10−5, OR 1.68, the family with sequence similarity 167 member A–B-lymphoid tyrosine kinase (FAM167A–BLK) locus, P=4.7 × 10−4, OR 1.37 and the tumor necrosis factor superfamily (TNFSF4=Ox40L) gene, P=7.4 × 10−4, OR 1.34. We also confirmed the association between primary SS and the IRF5/TNPO3 locus and the STAT4 gene. We found no association between the SNPs in these five genes and the presence of anti-SSA/anti-SSB antibodies. EBF1, BLK and TNFSF4 are all involved in B-cell differentiation and activation, and we conclude that polymorphisms in several susceptibility genes in the immune system contribute to the pathogenesis of primary SS.
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| 2. |
- Almlöf, Jonas Carlsson, et al.
(författare)
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Powerful Identification of Cis-regulatory SNPs in Human Primary Monocytes Using Allele-Specific Gene Expression
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:12, s. e52260-
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Tidskriftsartikel (refereegranskat)abstract
- A large number of genome-wide association studies have been performed during the past five years to identify associations between SNPs and human complex diseases and traits. The assignment of a functional role for the identified disease-associated SNP is not straight-forward. Genome-wide expression quantitative trait locus (eQTL) analysis is frequently used as the initial step to define a function while allele-specific gene expression (ASE) analysis has not yet gained a wide-spread use in disease mapping studies. We compared the power to identify cis-acting regulatory SNPs (cis-rSNPs) by genome-wide allele-specific gene expression (ASE) analysis with that of traditional expression quantitative trait locus (eQTL) mapping. Our study included 395 healthy blood donors for whom global gene expression profiles in circulating monocytes were determined by Illumina BeadArrays. ASE was assessed in a subset of these monocytes from 188 donors by quantitative genotyping of mRNA using a genome-wide panel of SNP markers. The performance of the two methods for detecting cis-rSNPs was evaluated by comparing associations between SNP genotypes and gene expression levels in sample sets of varying size. We found that up to 8-fold more samples are required for eQTL mapping to reach the same statistical power as that obtained by ASE analysis for the same rSNPs. The performance of ASE is insensitive to SNPs with low minor allele frequencies and detects a larger number of significantly associated rSNPs using the same sample size as eQTL mapping. An unequivocal conclusion from our comparison is that ASE analysis is more sensitive for detecting cis-rSNPs than standard eQTL mapping. Our study shows the potential of ASE mapping in tissue samples and primary cells which are difficult to obtain in large numbers.
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| 3. |
- Almlöf, Jonas, et al.
(författare)
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Single nucleotide polymorphisms with cis-regulatory effects on long non-coding transcripts in human primary monocytes
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:7, s. e102612-
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Tidskriftsartikel (refereegranskat)abstract
- We applied genome-wide allele-specific expression analysis of monocytes from 188 samples. Monocytes were purified from white blood cells of healthy blood donors to detect cis-acting genetic variation that regulates the expression of long non-coding RNAs. We analysed 8929 regions harboring genes for potential long non-coding RNA that were retrieved from data from the ENCODE project. Of these regions, 60% were annotated as intergenic, which implies that they do not overlap with protein-coding genes. Focusing on the intergenic regions, and using stringent analysis of the allele-specific expression data, we detected robust cis-regulatory SNPs in 258 out of 489 informative intergenic regions included in the analysis. The cis-regulatory SNPs that were significantly associated with allele-specific expression of long non-coding RNAs were enriched to enhancer regions marked for active or bivalent, poised chromatin by histone modifications. Out of the lncRNA regions regulated by cis-acting regulatory SNPs, 20% (n = 52) were co-regulated with the closest protein coding gene. We compared the identified cis-regulatory SNPs with those in the catalog of SNPs identified by genome-wide association studies of human diseases and traits. This comparison identified 32 SNPs in loci from genome-wide association studies that displayed a strong association signal with allele-specific expression of non-coding RNAs in monocytes, with p-values ranging from 6.7×10-7 to 9.5×10-89. The identified cis-regulatory SNPs are associated with diseases of the immune system, like multiple sclerosis and rheumatoid arthritis.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Adoue, Veronique, et al.
(författare)
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Allelic expression mapping across cellular lineages to establish impact of non-coding SNPs
- 2014
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Ingår i: Molecular Systems Biology. - : EMBO. - 1744-4292 .- 1744-4292. ; 10:10, s. 754-
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Tidskriftsartikel (refereegranskat)abstract
- Most complex disease-associated genetic variants are located in non-coding regions and are therefore thought to be regulatory in nature. Association mapping of differential allelic expression (AE) is a powerful method to identify SNPs with direct cis-regulatory impact (cis-rSNPs). We used AE mapping to identify cis-rSNPs regulating gene expression in 55 and 63 HapMap lymphoblastoid cell lines from a Caucasian and an African population, respectively, 70 fibroblast cell lines, and 188 purified monocyte samples and found 40-60% of these cis-rSNPs to be shared across cell types. We uncover a new class of cis-rSNPs, which disrupt footprint-derived de novo motifs that are predominantly bound by repressive factors and are implicated in disease susceptibility through overlaps with GWAS SNPs. Finally, we provide the proof-of-principle for a new approach for genome-wide functional validation of transcription factor-SNP interactions. By perturbing NFκB action in lymphoblasts, we identified 489 cis-regulated transcripts with altered AE after NFκB perturbation. Altogether, we perform a comprehensive analysis of cis-variation in four cell populations and provide new tools for the identification of functional variants associated to complex diseases.
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| 9. |
- Allard, Per, et al.
(författare)
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[Inventory of geriatric psychiatry in Sweden. In short supply where demand does not determine resource allocation].
- 2000
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 97:24, s. 2976-80
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Tidskriftsartikel (refereegranskat)abstract
- In 1999 The Swedish Society for Old Age Psychiatry conducted an investigation in all Swedish counties in order to survey existing organizations and resources for medical services intended for elderly people with psychiatric complaints. In some counties there were no out-patient units specifically aimed at elderly people with psychiatric diseases, while more than half had no out-patient units for the large group of elderly with psychiatric ailments other than dementia. The total number of beds was far less than international recommendations. Less than 5 per cent of the total number of Swedish psychiatrists and geriatricians hold positions exclusively for geriatric psychiatry. Access to geriatric psychiatry resources appears to be unevenly distributed, and may be found mainly in or near university cities.
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| 10. |
- Andersson, Thomas, et al.
(författare)
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Vanlig svamp gav ovanlig hudinfektion : Fallbeskrivning
- 1999
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; :45, s. 4926-4927
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Vid opportunistisk svampinfektion i huden är diagnosen sällan självklar. Ett samarbete mellan dermatolog, patolog och mykolog kan behövas, som i detta fall av kutan alternarios. Denna typ av svampinfektion innefattas i begreppet feohyfomykos.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Calles, Britt-Marie, et al.
(författare)
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Grunddatadomän transportsystem: Kompletterande underlag till den utforskande förstudien
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I mars 2022 levererade Trafikverket och samverkande myndigheter (Transportstyrelsen, Sjöfartsverket, Luftfartsverket, Trafikanalys och VTI, Statens väg- och transportforskningsinstitut) en rapport som sammanfattade den utforskande utvecklingen att utreda en grunddatadomän för transportsystemet. Föreliggande rapport är en komplettering till den ursprungliga rapporten och utgör Trafikverkets inklusive samverkande myndigheters sammantagna underlag (utforskande utveckling) för etablering av en grunddatadomän för transportsystemet. Arbetet har bedrivits under ledning av Myndigheten för digital förvaltning (DIGG) med Trafikverket som ansvarig för den utforskande utvecklingen. Till rapporten hör en bilaga, se länk till höger.Ursprunglig rapport: Grunddatadomän transportsystem: Samverkansuppdrag mellan transportmyndigheterna för att bedriva en utforskande utveckling att utreda en grunddatadomän för information kopplat till transportsystemet
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| 16. |
- Dahlgren, Andreas, et al.
(författare)
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Association of the estrogen receptor 1 (ESR1) gene with body height in adult males from two Swedish population cohorts
- 2008
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:3, s. e1807-
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Tidskriftsartikel (refereegranskat)abstract
- Human body height is a complex genetic trait with high heritability. We performed an association study of 17 candidate genes for height in the Uppsala Longitudinal Study of Adult Men (ULSAM) that consists of 1153 elderly men of age 70 born in the central region of Sweden. First we genotyped a panel of 137 single nucleotide polymorphism (SNPs) evenly distributed across the candidate genes in the ULSAM cohort. We identified 4 SNPs in the estrogen receptor gene (ESR1) on chromosome 6q25.1 with suggestive signals of association (p<0.05) with standing body height. This result was followed up by genotyping the same 25 SNPs in the ESR1 gene as in ULSAM in a second population cohort, the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort that consist of 507 males and 509 females of age 70 from the same geographical region as ULSAM. One SNP, rs2179922 located in intron 4 of ESR1 showed and association signal (p = 0.0056) in the male samples from the PIVUS cohort. Homozygote carriers of the G-allele of the SNP rs2179922 were on average 0.90 cm taller than individuals with the two other genotypes at this SNP in the ULSAM cohort and 2.3 cm taller in the PIVUS cohort. No association was observed for the females in the PIVUS cohort.
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| 17. |
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| 18. |
- Ekberg, Niclas, et al.
(författare)
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Pekplattan och lärarutbildningen - om studenters och pekplattors intra-agerande
- 2016
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Ingår i: NU2016. Högskolan i samhället. Samhället i högskolan. Malmö 16-17 juni 2016. ; , s. 107-108
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Konferensbidrag (refereegranskat)abstract
- Syftet med detta paper är att presentera och diskutera erfarenheterna av att introducera och använda pekplattan som pedagogisk resurs för studenter och lärare i en förskollärarutbildning. Fokus fästs på att utifrån ett posthumanistiskt perspektiv och en rhizomatisk syn på lärandet förstå och diskutera tekniksatsningarna i utbildningen som samtillblivelser av lärarstudenter och pekplattor. Projektet ”Pekplattan som resurs – ett pedagogiskt verktyg för lärare och lärande”, har bedrivits mellan VT2014 och HT2015 och inbegripit 42 studenter, i slutet av sin utbildning, samt nio lärare. Satsningen har ingått som del av Luleå tekniska universitets pedagogiska utvecklingsarbete, med medel från universitets utvecklingsfond. Projektet, syftande till att utforska pekplattans pedagogiska möjligheter och utveckla metoder som berikar undervisningen och lärandet, initierades under VT2014 bland lärarna för att under läsåret 2014/2015 också inbegripa studenterna. Det har innefattat inköp och utdelning av pekplattor och applikationer till lärare och studenter, fortbildningsinsatser för lärarna, egenproduktion av utbildnings- och instruktionsmaterial för projektdeltagarna, teknikinvesteringar i lektionssalar samt organiserade kollegiala erfarenhetsutbyten. Under projektets gång har data insamlats från deltagarna genom återkommande enkäter, bestående av både öppna och slutna svarsalternativ, samt genom dokumenterade kollegiala samtal. Den första resultatanalysen utmynnade i tre teman, vilka karaktäriserar vilka betydelser teknikanvändningen har kommit att få för projektdeltagarna. Dessa tre teman är Personal Learning Environment (PLE), undervisningens och lärandets gestaltning samt professionalisering. Studenterna framhåller hur den mobila tekniken bidragit till en mer personifierad studiemiljö och studiesituation. Den ständiga tillgången till och möjligheten att själv arrangera läromaterialet visade sig inte bara betydelsefull för studenternas upplevelse av tekniken som ett organisatoriskt stöd för studierna. Teknikanvändningen har även kommit att främja studenternas självständighet vad gäller produktion och presentation i utbildningen och har vidare bidragit till deras upplevelser av ett ökat engagemang och en ökad självkänsla. Projektets fokus på lärandets multimodala aspekter har inneburit nya vägar till kunskapsrepresentation och reflektion. Genom att nyttja flera olika uttrycksformer och själva figurera i olika produktioner och representationer har studenterna upplevt ett rikare lärande och en större glädje och kreativitet i studierna. Projektet har därtill visat sig ha betydelse för studenternas professionalisering då det bidragit till en högre beredskap att använda de tekniska resurserna samt givit ett större mod att både möta och ta en egen plats i förskoleverksamheten. Den inledande resultatuppföljningen gav oss som forskarlag, tillika projektdeltagande lärare, en del svar på våra frågor om pekplatteanvändningens betydelse för såväl undervisningens villkor som studenternas lärande och professionalisering, men väckte i sin tur även nya: Vad innebär lärarstudentens möte med den mobila tekniken för lärandets villkor, vägar och uttryck? Till vem blir studenten och till vad blir pekplattan i det inom utbildningen arrangerade mötet mellan människa-teknik? Hur kan lärarstudenters och pekplattans intra-agerande förstås? Med utgångspunkt frågorna genomfördes en fördjupad studie bland de projektdeltagande studenterna. Vårt datamaterial består i sju videodokumenterade gruppsamtalsessioner under vilka studenterna behandlar och diskuterar fyra givna frågeställningar av öppen karaktär. Vi avser att under presentationen både redogöra för resultaten av vår studie och diskutera det posthumanistiska perspektivets möjligheter till förståelse av studenters möte med och relationer till den mobila informations- och kommunikationstekniken.
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| 19. |
- Engstrand, J., et al.
(författare)
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The Resection Rate of Synchronously Detected Liver and Lung Metastasis from Colorectal Cancer Is Low-A National Registry-Based Study
- 2023
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 15:5
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Real-life data on the occurrence and treatment of synchronously detected liver and lung metastases from colorectal cancer are lacking. Through the merging of several Swedish nationwide patient quality registries, we aimed to answer these questions. We found that synchronous liver and lung colorectal metastases are rare and that a minority undergo resection of both metastatic sites, but if they do, they have an excellent survival. It is likely that a larger proportion of patients could be offered treatment that leads to a prolonged overall survival. We also found differences in regional treatment approaches across Sweden, but the reasons for this are unknown, which warrants further studies. Population-based data on the incidence and surgical treatment of patients with colorectal cancer (CRC) and synchronous liver and lung metastases are lacking as are real-life data on the frequency of metastasectomy for both sites and outcomes in this setting. This is a nationwide population-based study of all patients having liver and lung metastases diagnosed within 6 months of CRC between 2008 and 2016 in Sweden identified through the merging of data from the National Quality Registries on CRC, liver and thoracic surgery and the National Patient Registry. Among 60,734 patients diagnosed with CRC, 1923 (3.2%) had synchronous liver and lung metastases, of which 44 patients had complete metastasectomy. Surgery of liver and lung metastases yielded a 5-year OS of 74% (95% CI 57-85%) compared to 29% (95% CI 19-40%) if liver metastases were resected but not the lung metastases and 2.6% (95% CI 1.5-4%) if non-resected, p < 0.001. Complete resection rates ranged from 0.7% to 3.8% between the six healthcare regions of Sweden, p = 0.007. Synchronous liver and lung CRC metastases are rare, and a minority undergo the resection of both metastatic sites but with excellent survival. The reasons for differences in regional treatment approaches and the potential of increased resection rates should be studied further.
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| 20. |
- Gunnarsson, Rebeqa, et al.
(författare)
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Mutation, methylation, and gene expression profiles in dup(1q)-positive pediatric B-cell precursor acute lymphoblastic leukemia
- 2018
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551. ; 32:10, s. 2117-2125
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Tidskriftsartikel (refereegranskat)abstract
- High-throughput sequencing was applied to investigate the mutation/methylation patterns on 1q and gene expression profiles in pediatric B-cell precursor acute lymphoblastic leukemia (BCP ALL) with/without (w/wo) dup(1q). Sequencing of the breakpoint regions and all exons on 1q in seven dup(1q)-positive cases revealed non-synonymous somatic single nucleotide variants (SNVs) in BLZF1, FMN2, KCNT2, LCE1C, NES, and PARP1. Deep sequencing of these in a validation cohort w (n = 17)/wo (n = 94) dup(1q) revealed similar SNV frequencies in the two groups (47% vs. 35%; P = 0.42). Only 0.6% of the 36,259 CpGs on 1q were differentially methylated between cases w (n = 14)/wo (n = 13) dup(1q). RNA sequencing of high hyperdiploid (HeH) and t(1;19)(q23;p13)-positive cases w (n = 14)/wo (n = 52) dup(1q) identified 252 and 424 differentially expressed genes, respectively; only seven overlapped. Of the overexpressed genes in the HeH and t(1;19) groups, 23 and 31%, respectively, mapped to 1q; 60-80% of these encode nucleic acid/protein binding factors or proteins with catalytic activity. We conclude that the pathogenetically important consequence of dup(1q) in BCP ALL is a gene-dosage effect, with the deregulated genes differing between genetic subtypes, but involving similar molecular functions, biological processes, and protein classes.
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| 21. |
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| 22. |
- Hedwall, Per-Ola, et al.
(författare)
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Interplay between N-form and N-dose influences ecosystem effects of N addition to boreal forest
- 2018
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Ingår i: Plant and Soil. - : Springer Science and Business Media LLC. - 0032-079X .- 1573-5036. ; 423, s. 385-395
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen (N) addition effects on boreal forest ecosystem are influenced by an interplay between N-form and N-dose. We hypothesize that trees take up organic N more efficiently than inorganic N and that unwanted side-effects of organic N are smaller. We predicted that 1) the tree growth response to arginine (ARG) addition is larger than to ammonium-nitrate (AN) and, 2) understory vegetation and ectomycorrhizal (EcM) changes following ARG addition are smaller than following AN addition.We investigated the effects of AN and ARG addition (50 and 150 kg N ha(-1)) during five years on tree growth, understory vegetation and EcM fungi in a Pinus sylvestris L. forest (c 50 years old) in northern Sweden.N addition increased tree growth and changed understory vegetation composition with few significant differences between AN and ARG. Differences in responses mainly occurred for the bryophyte Pleurozium schreberi which decreased more from ARG, and for EcM sporocarps, which sharply declined from AN, but not from ARG.We found very few differences in responses between AN and ARG addition with the exception of EcM and bryophytes. These species groups have several key functions in boreal forests and the differences in responses merits further investigations.
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| 23. |
- Håkansson, Charlotta, 1971-
(författare)
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Greenhouse Gas Fluxes and Carbon Sequestration in Young Norway Spruce Stands : The Effects of Fertilization
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance.The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021.The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become carbon sinks already eight years after the storm with a net uptake of about 18 ton CO2 ha-1 yr-1 of. The forest floor fluxes of CH4 and N2O also show a short-term effect of fertilization, however the levels are very low compared to CO2. The fertilization induced increase of total tree biomass growth increased with time. The results show that 12 and 15 years after regeneration, the fertilization compared to the control has increased the tree growth by 3.4 and 6.3 m3 ha-1 yr-1 and carbon storage by 4.7 and 8.7 ton C ha-1 yr-1 respectively.Comparison of measurement results of the Eddy-flux technique's netflows and chamber measurements of soil respiration together with tree growth shows the importance of calibrating the measurement methods when the results are later to be used in modeling future climate scenarios.
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| 24. |
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| 25. |
- Jawerth, Marcus, et al.
(författare)
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Mechanical and Morphological Properties of Lignin-Based Thermosets
- 2020
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Ingår i: ACS APPLIED POLYMER MATERIALS. - : AMER CHEMICAL SOC. - 2637-6105. ; 2:2, s. 668-676
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Tidskriftsartikel (refereegranskat)abstract
- The need for renewable alternatives for fossil-based aromatic material constituents is evident for a more sustainable society. Lignin is the largest source of naturally occurring aromatic compounds but has mainly been considered as waste material or energy source in the pulp and paper industry. Developments in extracting lignin from these processes provide a large source for renewable aromatic structures to be used in various applications. Producing thermosets out of lignin is a very promising route to utilize this raw material toward, for example, composite application. The buildup of the molecular network based on oligomeric lignin segments will be different from traditional thermoset analogues, where the constituents often are smaller molecules, and will have an effect on the material properties. In this work LignoBoost Kraft lignin is refined, chemically modified, and used to produce freestanding thermosets with different architectures and properties. These different thermosets are evaluated, and the possibilities to tailor the material properties through work-up and modification are demonstrated. Morphological studies on the formed thermosets using X-ray scattering show systematic differences in molecular stacking and aggregate sizes.
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| 26. |
- Lind, Lars, et al.
(författare)
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Variation in genes in the endothelin pathway and endothelium-dependent and endothelium-independent vasodilation in an elderly population
- 2013
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 208:1, s. 88-94
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Tidskriftsartikel (refereegranskat)abstract
- Aim Indirect evidences by blockade of the endothelin receptors have suggested a role of endothelin in endothelium-dependent vasodilation. This study aimed to investigate whether circulating levels of endotehlin-1 or genetic variations in genes in the endothelin pathway were related to endothelium-dependent vasodilation. Methods In 1016 seventy-year-old participants of the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (52% women), we measured endothelium-dependent vasodilation using the invasive forearm technique with acetylcholine given in the brachial artery (EDV) and the brachial artery ultrasound technique with measurement of flow-mediated dilatation (FMD). Plasma endothelin-1 levels were measured and 60 SNPs in genes in the endothelin pathway (ECE1, EDN1, EDNRA, EDNRB) were genotyped. Results No significant associations were found between circulating endothelin levels and EDV or FMD. No single genotype was related to EDV or FMD following adjustment for multiple testing, but a genotype score for 3 SNPs (rs11618266 in EDNRB, rs17675063 in EDNRA, rs3026868 in ECE1) was significantly related to EDV (beta coefficient 0.070, 95% CI 0.0250.12, P=0.002) when adjusting for gender, systolic blood pressure, HDL and LDL cholesterol, serum triglycerides, BMI, diabetes, smoking, antihypertensive medication or statins and CRP. This score was also related to nitroprusside-induced vasodilation in the forearm. Conclusion A combination of genotypes in the endothelin pathway was related to both endothelium-dependent and endothelium-independent vasodilation in forearm resistance vessels, but not in the brachial artery in an elderly population, giving evidence for a role of the endothelin system in resistance vessel reactivity independent of major cardiovascular risk factors.
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| 27. |
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| 28. |
- Lundmark, Annika, et al.
(författare)
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Estimating the fate of de-icing salt in a roadside environment by combining modelling and field observations
- 2008
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 195:1-4, s. 215-232
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Tidskriftsartikel (refereegranskat)abstract
- Predicting the environmental effects of de-icing salt requires knowledge of the pathways taken by salt from on-road application through spread to the surroundings to deposition and fate in the roadside environment. This study described differences in chloride deposition and distribution in soil with increasing distance from the road by means of field observations and modelling. The dynamic modelling approach successfully represented the spread of de-icing salt from road to surroundings, deposition in the roadside environment and the subsequent infiltration into roadside soil. The general decrease in soil chloride content with distance from the road was described by differences in salt deposition, soil physical properties, vegetation properties and snow characteristics. The uncertainty in model predictions was highest in areas close to the road due to a complex combination of high salt deposition, snow-ploughed masses and road runoff. The exponential decline in salt deposition with distance from the road could not be justified close to the road. Different types of field investigations were applied in a calibration procedure to establish reasonable ranges for the most influential model parameters. Measured electrical resistivity reflected well the changes in simulated chloride content in soil during winter and spring when chloride concentrations were high. However, during summer or periods with low chloride concentrations the measured resistivity was substantially lower than simulated values, as it reflected the total contamination level in soil.
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| 29. |
- Lundmark, Annika, et al.
(författare)
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Generic soil descriptions for modelling water and chloride dynamics in the unsaturated zone based on Swedish soils
- 2009
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Ingår i: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 150:1-2, s. 85-95
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Tidskriftsartikel (refereegranskat)abstract
- Information about soil hydraulic properties is a prerequisite for modelling water and solute dynamics in the unsaturated zone. Providing that this information is available and the uncertainty is within an acceptable range, computer models can be helpful tools in quantifying environmental effects. This study describes the water retention curve and hydraulic conductivity for three soil types: clay, glacial till and sand. These soils originated from a Swedish database containing 2200 measured soil layers representing 260 soil profiles. A simulation experiment was conducted where daily variations in water and chloride were simulated for a 20-year period in central Sweden, using the different soil profiles sampled from the database. Two approaches to calculate effective parameters were tested, in order to obtain generic soil descriptions and examine their ability to represent the average of the variation in chloride and water characteristics obtained for the respective soil type. In general, the use of these effective parameters was successful but overestimations of the water and chloride outflow occurred in the clay, which presented high spatial variability, and of the chloride concentration in the sand, which presented high temporal variability. Overall, the generic soil descriptions were useful in producing reasonable behaviour regarding water and chloride dynamics and could be recommended for general assessments of the environmental impact of non-reactive solutes from ;areas where simplified soil classifications are available.
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| 30. |
- Lundmark, Annika, 1972-
(författare)
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Monitoring transport and fate of de-icing salt in the roadside environment : Modelling and field measurements
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Roads and traffic are a major non-point source of pollutants and may have severe impacts on surface water, groundwater, soil and vegetation. In cold climates, de-icing salt is one such pollutant that may cause increased chloride concentrations and induce other effects on the environment. Monitoring and quantifying environmental effects are crucial for governing decisions towards more suitable use of de-icing salt in order to achieve and maintain good environmental status around roads. This thesis presents an operational modelling tool for monitoring the transport and fate of de-icing salt in the roadside environment in order to quantify changes in the environment at various spatial and temporal scales, using salt application data, meteorological data, geology and generic descriptions of hydrogeological environments as main inputs. A combination of modelling and various independent field measurements provided an efficient means for evaluating and describing the spread of de-icing salt from the road to the surroundings, the deposition of salt and ploughed snow in the roadside, and the corresponding increase in chloride concentration in soil and groundwater. Both the spatial and seasonal variation in soil chloride concentration were significantly affected by de-icing salt application. The importance of type of soil, vegetation type, groundwater conditions and distance from the road was clearly demonstrated for modelling the transport and fate of de-icing salt in the roadside environment. Salt emissions from the road by surface runoff were estimated at 50-80% of applied salt and transport by snow ploughing and air emissions at 20-50%. The uncertainty in the spatial distribution of snow and salt deposition close to the road was high and a previous proposed exponential decline in salt deposition with distance from the road could not be justified within a couple of metres from the road. Future monitoring should include both modelling and systematic data collection in order to reduce the uncertainty in predictions of the environmental impact of de-icing salt. Modelling of chloride concentration, soil water content and soil temperature and measurements of electrical resistivity may be a cost-effective solution for quantifying changes in the roadside environment.
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| 31. |
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| 32. |
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| 33. |
- Lundmark, Katarzyna, et al.
(författare)
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Naturally occurring fibrillar proteins can induce AA amyloidosis by a prion-like mechanism
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Experimental AA amyloidosis, where the acute phase protein serum AA (SAA) forms amyloid fibrils, can be induced in mice provoked with inflannnatmy challenge. The time for development of amyloid is dramatically shortened when the animals concomitantly receive extract of a tissue from another mouse with amyloid 1-3. The active elusive principle has been named Amyloid Enhancing Factor (AEF) and experimental secondary amyloidosis was supposed to be a nucleation dependent process. The nature of the nucleus, however, was unknown for a long time. Our studies with synthetic amyloid-like fibrils made frmn short amyloidogenic pep tides instead of AEF 4, 5, indicate that the amyloid fibrils theruselves may act as nuclei for fibril formation (Fig. 1a). Here we present the enhanced development of AA -amyloidosis by naturally occurring amyloid-like protein fibrils.
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| 34. |
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| 35. |
- Lundmark, Katarzyna, et al.
(författare)
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Transmissibility of systemic amyloidosis by a prion-like mechanism
- 2002
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 99:10, s. 6979-6984
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Tidskriftsartikel (refereegranskat)abstract
- The generation of amyloid fibrils from an amyloidogenic polypeptide occurs by a nucleation-dependent process initiated in vitro by seeding the protein solution with preformed fibrils. This phenomenon is evidenced in vivo by the fact that amyloid protein A (AA) amyloidosis in mice is markedly accelerated when the animals are given, in addition to an inflammatory stimulus, an i.v. injection of protein extracted from AA amyloid-laden mouse tissue. Heretofore, the chemical nature of this “amyloid enhancing factor” (AEF) has not been definitively identified. Here we report that the active principle of AEF extracted from the spleen of mice with silver nitrate-induced AA amyloidosis was identified unequivocally as the AA fibril itself. Further, we demonstrated that this material was extremely potent, being active in doses <1 ng, and that it retained its biologic activity over a considerable length of time. Notably, the AEF was also effective when administered orally. Our studies have provided evidence that AA and perhaps other forms of amyloidosis are transmissible diseases, akin to the prion-associated disorders.
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| 36. |
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| 37. |
- Lundmark, Per E, et al.
(författare)
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Evaluation of HapMap data in six populations of European descent
- 2008
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 16:9, s. 1142-1150
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Tidskriftsartikel (refereegranskat)abstract
- We studied how well the European CEU samples used in the Haplotype Mapping Project (HapMap) represent five European populations by analyzing nuclear family samples from the Swedish, Finnish, Dutch, British and Australian (European ancestry) populations. The number of samples from each population (about 30 parent-offspring trios) was similar to that in the HapMap sample sets. A panel of 186 single nucleotide polymorphisms (SNPs) distributed over the 1.5 Mb region of the GRID2 gene on chromosome 4 was genotyped. The genotype data were compared pair-wise between the HapMap sample and the other population samples. Principal component analysis (PCA) was used to cluster the data from different populations with respect to allele frequencies and to define the markers responsible for observed variance. The only sample with detectable differences in allele frequencies was that from Kuusamo, Finland. This sample also separated from the others, including the other Finnish sample, in the PCA analysis. A set of tagSNPs was defined based on the HapMap data and applied to the samples. The tagSNPs were found to capture the genetic variation in the analyzed region at r(2)>0.8 at levels ranging from 95% in the Kuusamo sample to 87% in the Australian sample. To capture the maximal genetic variation in the region, the Kuusamo, HapMap and Australian samples required 58, 63 and 73 native tagSNPs, respectively. The HapMap CEU sample represents the European samples well for tagSNP selection, with some caution regarding estimation of allele frequencies in the Finnish Kuusamo sample, and a slight reduction in tagging efficiency in the Australian sample.
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| 38. |
- Lundmark, Per Erik, 1976-
(författare)
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Genetic and Genomic Analysis of DNA Sequence Variation
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The studies in this thesis describe the application of genotyping and allele specific expression analysis to genetic studies. The role of the gene NPC1 in Triglyceride metabolism was explored in mouse models and in humans on the population level in study I. NPC1 was found to affect hepatic triglyceride metabolism, and to be relevant for controlling serum triglyceride levels in mice and potentially in humans. In study II the utility of the HapMap CEU samples was investigated for tagSNP selection in six European populations. The HapMap CEU was found to be representative for tagSNP selection in all populations while allele frequencies differed significantly in the sample from Kuusamo, Finland. In study III the power of Allele specific expression as a tool for the mapping of cis-regulatory variation was compared to standard eQTL analysis, ASE was found to be the more powerful type of analysis for a similar sample size. Finally ASE mapping was applied to regions reported to harbour long non-coding RNAs and associated SNPs were compared to published trait-associations. This revealed strong cis-regulatory SNPs of long non-coding RNAs with reported trait or disease associations.
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| 39. |
- Lundmark, Ralf, et al.
(författare)
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Fågelskär i Mälaren 2016 : Heltäckande inventering av kolonihäckande sjöfågel
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Länsstyrelserna i Uppsala, Södermanlands, Västmanlands och Stockholms län bedriver tillsammans med Mälarens vattenvårdsförbund fågelinventering i Mälaren som en del av den regionala miljöövervakningen. Ralf Lundmark har under 2016 fungerat som fältprojektledare och har författat ett underlag till föreliggande resultatrapport. Per Hedenbo, Länsstyrelsen i Västmanlands län, har producerat områdeskartan samt sammanställt tabellerna över antal inventerade fåglar som återfinns i slutet av dokumentet.
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| 40. |
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| 41. |
- Mellander, Per-Erik, et al.
(författare)
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Recovery of photosynthetic capacity in Scots pine : a model analysis of forest plots with manipulated winter/spring soil temperature regimes.
- 2008
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Ingår i: European Journal of Forest Research. - : Springer Science and Business Media LLC. - 1612-4669 .- 1612-4677. ; 127:1, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- Both aboveground and belowground climate affects net primary production (NNP) and forest growth. Little is known about how above and belowground factors interact. The BIOMASS-model was tested to simulate photosynthetic recovery over a wide range of soil temperatures created by snow cover manipulations on tree-scale plots in a 20-year-old Scots pine stand in northern Sweden. The differences in timing of soil warming between the plots covered a span of two months. Carbon assimilation in needles, sap flow, needle water potential and climatic parameters were measured in the field. The simulations revealed that an early start of soil warming gave a relatively early photosynthetic recovery and a 7.5% increase of NPP. Late soil warming delayed the photosynthetic recovery and reduced the NPP by 13.7%. This indicated that soil temperature needed to be accounted for, as well as air temperature, when analysing photosynthetic recovery and NPP in boreal environment. The effects of differences in soil temperature were reflected in the simulated photosynthetic recovery. The model did not fully capture the delay of photosynthetic recovery caused by a late soil warming. It was possible to integrate the complexity of the soil climate effects into a threshold date for soil thaw, using sapflow measurements together with information about air temperature and a day degree sum, as long as water availability was not limiting water uptake by roots. Although a more realistic mechanism than that currently in BIOMASS is desirable as climate change shifts the typical patterns of interplay between air and soil temperature dynamics.
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| 42. |
- Mellander, Per-Erik, et al.
(författare)
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The influence of soil temperature on transpiration: : a plot scale manipulation in a young Scots pine stand
- 2004
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127. ; 195:1-2, s. 15-28
-
Tidskriftsartikel (refereegranskat)abstract
- Classic studies have stressed the importance of forest management for soil frost and the dynamics of soil warming during spring. But, we know very little about the potential loss of forest production due to cold soils. Liquid soil water may not be available to trees due to cold soil conditions, thus reducing transpiration and photosynthesis. We believe that these effects need to be quantified in order to keep silvicultural practices from inadvertently reducing forest growth through effects on soil temperature. In order to test this hypothesis it is important to know more about water uptake in the field by trees in cold environments. The snow cover was manipulated on plots in a young stand of Pinus sylvestris L. to create plots with different timings of soil warming. Soil profile temperature and liquid water content, as well as snow and frost depths, were measured together with tree physiological parameters such as sap flow, stomatal conductance and needle water potential. The study has confirmed the importance of the soil temperature for tree water uptake when soil warming was delayed beyond the start of growing season as defined by air temperature. The absence of frost (and hence the presence of liquid water) was not sufficient to enable water uptake. It was rather elevation of soil temperature above zero in the upper soil layers that was required for substantial water uptake, in combination with other site factors. Below ca. +8 °C, soil temperature was a factor in the restriction of transpiration, explained by a lower stomatal conductance and likely decreased root permeability. The effect of a certain soil temperature was not the same at different times due to its interaction with aboveground factors such as air temperature and day-length. The effect of low soil temperature increased with the persistence of low temperatures after the start of the growing season. The timings of soil warming induced by our study were within the spatial and inter-annual variation of soil warming in this region. Thus, we conclude that influences of forest management on soil temperature can affect the transpiration deficit during spring, with potential implications for forest productivity
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| 43. |
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| 44. |
- Nilsson, Urban, et al.
(författare)
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Thinning of Scots pine and Norway spruce monocultures in Sweden: effects of different thinning programmes on standlevel gross- and net stem volume production
- 2010
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Ingår i: Studia Forestalia Suecica. - 0039-3150. ; 219, s. 1-46
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The effect of thinning intensity, thinning interval, thinning form and timing of the first thinning on stand level gross- andnet stem volume production in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst) was investigatedin a nationwide field experiment across Sweden. In total, 35 Scots pine sites distributed from the south to the north ofSweden and 13 Norway spruce sites located in the south and central parts of Sweden were investigated. Thinning treatments ranged from unthinned control, to light and moderate repeated thinnings, to a treatmentwhere 60-70% of the basal area was removed in a single thinning. In addition, thinning from above was compared tothinning from below and delayed first thinning was compared to early first thinning. The average measurement period was31 years for Scots pine and 30 years for Norway spruce. All Scots pine thinning treatments reduced the total gross stemvolume production compared to the unthinned control, whereas only the heaviest thinning treatments, in which a largeproportion of the basal area was removed, reduced the total gross stem volume production for Norway spruce. Thinningfrom above did not affect total gross stem volume production of Scots pine, but there was a tendency towards lowerproduction in Norway spruce. For Norway spruce, thinning from above resulted in lower net stem volume production thanthinning from below. Delaying the first thinning did not affect gross stem volume production for either Scots pine orNorway spruce. Net volume production and volume production in trees with diameter at breast height > 8 cm was higher forthe light thinning treatment than for the unthinned control in Norway spruce. In Scots pine, there was no differencebetween the light thinning treatment and unthinned control in net volume production. For cots pine, the heavy thinningtreatments decreased net volume production compared to the unthinned threatment whereas there were no differences innet volume production between the heavy thinning treatments and unthinned control in Norway spruce
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| 45. |
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| 46. |
- Panahi, Aida Vahdat Shariat, et al.
(författare)
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Lipid membranes accelerate amyloid formation in the mouse model of AA amyloidosis
- 2019
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Ingår i: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 26:1, s. 34-44
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Tidskriftsartikel (refereegranskat)abstract
- Introduction:AA amyloidosis develops as a result of prolonged inflammation and is characterized by deposits of N-terminal proteolytic fragments of the acute phase reactant serum amyloid A (SAA). Macrophages are usually found adjacent to amyloid, suggesting their involvement in the formation and/or degradation of the amyloid fibrils. Furthermore, accumulating evidence suggests that lipid membranes accelerate the fibrillation of different amyloid proteins.Methods:Using an experimental mouse model of AA amyloidosis, we compared the amyloidogenic effect of liposomes and/or amyloid-enhancing factor (AEF). Inflammation was induced by subcutaneous injection of silver nitrate followed by intravenous injection of liposomes and/or AEF to accelerate amyloid formation.Results:We showed that liposomes accelerate amyloid formation in inflamed mice, but the amyloidogenic effect of liposomes was weaker compared with AEF. Regardless of the induction method, amyloid deposits were mainly found in the marginal zones of the spleen and coincided with the depletion of marginal zone macrophages, while red pulp macrophages and metallophilic marginal zone macrophages proved insensitive to amyloid deposition.Conclusions:We conclude that increased intracellular lipid content facilitates AA amyloid fibril formation and show that the mouse model of AA amyloidosis is a suitable system for further mechanistic studies.
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| 47. |
- Penell, Johanna, et al.
(författare)
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Genetic variation in the CYP2B6 Gene is related to circulating 2,2 ',4,4 '-tetrabromodiphenyl ether (BDE-47) concentrations : an observational population-based study
- 2014
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Ingår i: Environmental Health. - London : BioMed Central (BMC). - 1476-069X. ; 13, s. 34-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Since human CYP2B6 has been identified as the major CYP enzyme involved in the metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and that human 2B6 is a highly polymorphic CYP, with known functional variants, we evaluated if circulating concentrations of a major brominated flame retardant, BDE-47, were related to genetic variation in the CYP2B6 gene in a population sample.Methods: In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (men and women all aged 70), 25 single nucleotide polymorphisms (SNPs) in the CYP2B6 gene were genotyped. Circulating concentrations of BDE-47 were analyzed by high-resolution gas chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS).Results: Several SNPs in the CYP2B6 gene were associated with circulating concentrations of BDE-47 (P = 10(- 4) to 10(-9)). The investigated SNPs came primarily from two haplotypes, although the correlation between the haplotypes was rather high. Conditional analyses adjusting for the SNP with the strongest association with the exposure (rs2014141) did not provide evidence for independent signals.Conclusion: Circulating concentrations of BDE-47 were related to genetic variation in the CYP2B6 gene in an elderly population.
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| 48. |
- Petersson, Hans, et al.
(författare)
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On the role of forests and the forest sector for climate change mitigation in Sweden
- 2022
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1707 .- 1757-1693. ; 14:7, s. 793-813
-
Tidskriftsartikel (refereegranskat)abstract
- We analyse the short- and long-term consequences for atmospheric greenhouse gas (GHG) concentrations of forest management strategies and forest product uses in Sweden by comparing the modelled consequences of forest resource use vs. increased conservation at different levels of GHG savings from carbon sequestration and product substitution with bioenergy and other forest products. Increased forest set-asides for conservation resulted in larger GHG reductions only in the short term and only when substitution effects were low. In all other cases, forest use was more beneficial. In all scenarios, annual carbon dioxide (CO2) sequestration rates declined in conservation forests as they mature, eventually approaching a steady state. Forest set-asides are thus associated with increasing opportunity costs corresponding to foregone wood production and associated mitigation losses. Substitution and sequestration rates under all other forest management strategies rise, providing support for sustained harvest and cumulative mitigation gains. The impact of increased fertilization was everywhere beneficial to the climate and surpassed the mitigation potential of the other scenarios. Climate change can have large—positive or negative—influence on outcomes. Despite uncertainties, the results indicate potentially large benefits from forest use for wood production. These benefits, however, are not clearly linked with forestry in UNFCCC reporting, and the European Union's Land Use, Land-Use Change and Forestry carbon accounting, framework may even prevent their full realization. These reporting and accounting frameworks may further have the consequence of encouraging land set-asides and reduced forest use at the expense of future biomass production. Further, carbon leakage and resulting biodiversity impacts due to increased use of more GHG-intensive products, including imported products associated with deforestation and land degradation, are inadequately assessed. Considerable opportunity to better mobilize the climate change mitigation potential of Swedish forests therefore remains.
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| 49. |
- Pyo, Sang-Hyun, et al.
(författare)
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Cyclic carbonates as monomers for phosgene- and isocyanate-free polyurethanes and polycarbonates
- 2012
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Ingår i: Pure and Applied Chemistry. - 0033-4545. ; 84:3, s. 637-661
-
Forskningsöversikt (refereegranskat)abstract
- Polyurethanes and polycarbonates are widely used in a variety of applications including engineering, optical devices, and high-performance adhesives and coatings, etc., and are expected to find use also in the biomedical field owing to their biocompatibility and low toxicity. However, these polymers are currently produced using hazardous phosgene and isocyanates, which are derived from the reaction between an amine and phosgene. Extensive safety procedures are required to prevent exposure to phosgene and isocyanate because of its high toxicity. Therefore, the demand for the production of isocyanate-free polymers has now emerged. Among the alternative greener routes that have been proposed, a popular way is the ring-opening polymerization (ROP) of cyclic carbonate in bulk or solution, usually using metallic catalyst, metal-free initiator, or biocatalyst. This review presents the recent developments in the preparation and application of cyclic carbonates as monomers for ROP, with emphasis on phosgene-and isocyanate-free polymerization to produce aliphatic polycarbonates and polyurethanes and their copolymers.
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| 50. |
- Pyo, Sang-Hyun, et al.
(författare)
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Lipase-mediated synthesis of six-membered cyclic carbonates from trimethylolpropane and dialkyl carbonates: Influence of medium engineering on reaction selectivity
- 2011
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Ingår i: Journal of Molecular Catalysis B: Enzymatic. - : Elsevier BV. - 1873-3158 .- 1381-1177. ; 73:1-4, s. 67-73
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Tidskriftsartikel (refereegranskat)abstract
- Six-membered cyclic carbonates are potential monomers for aliphatic polycarbonates and polyurethanes in a process without using toxic phosgene and isocyanate. Lipase catalyzed transesterification of the polyol, trimethylolpropane (TMP) with dimethyl carbonate (DMC) or diethyl carbonate (DEC) followed by thermal cyclization was used for synthesis of six-membered cyclic carbonates with pendant hydroxyl and alkoxycarbonyloxyl groups. Immobilized lipase B from Candida antarctica (Novozym (R) 435) was used as the catalyst. Mixture of a hydrophilic solvent such as THF for high solubility of TMP, and a hydrophobic solvent such as toluene, were selected as the best solvent system for achieving high substrate conversion and selectivity. A relationship between polyol conversion and solvent hydrophobicity (log P) and solvent type, respectively, was established. THF:toluene system at a ratio of 0.5:1.0 (v/v) provided high degree of TMP conversion to product with high proportion of cyclic carbonates (>80%). The cyclic carbonate with pendant hydroxyl group was obtained with almost 85% selectivity at TMP conversion of 68.6% using 10% (w/w)Novozym (R) 435 at TMP:DMC ratio of 1:1. However, at TMP:DMC ratio of 1:5 and the same biocatalyst concentration, the TMP conversion was 100% with 72% selectivity for the cyclic carbonate with pendant alkoxycarbonyloxyl group. The product formed was without or with less content of linear carbonates, bis and tris(methoxycarbonyloxy)-TMP, as compared to that in a solvent-free system. The reactivity of DEC was lower than that of DMC. The reaction pathway leading to the formation of cyclic carbonate in this process comprised enzymatic carbonation of TMP with alkylcarbonates and thermal cyclization of linear carbonates. The process affords high degree of conversion of polyol to cyclic carbonates and provides a potentially attractive synthetic route for monomers of polycarbonates and polyurethanes. (C) 2011 Elsevier B.V. All rights reserved.
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