| 1. |
- Gyllenberg, A, et al.
(författare)
-
Variability in the CIITA gene interacts with HLA in multiple sclerosis.
- 2014
-
Ingår i: Genes and immunity. - Stockholm : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 15, s. 162-167
-
Tidskriftsartikel (refereegranskat)abstract
- The human leukocyte antigen (HLA) is the main genetic determinant of multiple sclerosis (MS) risk. Within the HLA, the class II HLA-DRB1*15:01 allele exerts a disease-promoting effect, whereas the class I HLA-A*02 allele is protective. The CIITA gene is crucial for expression of class II HLA molecules and has previously been found to associate with several autoimmune diseases, including MS and type 1 diabetes. We here performed association analyses with CIITA in 2000 MS cases and up to 6900 controls as well as interaction analysis with HLA. We find that the previously investigated single-nucleotide polymorphism rs4774 is associated with MS risk in cases carrying the HLA-DRB1*15 allele (P=0.01, odds ratio (OR): 1.21, 95% confidence interval (CI): 1.04-1.40) or the HLA-A*02 allele (P=0.01, OR: 1.33, 95% CI: 1.07-1.64) and that these associations are independent of the adjacent confirmed MS susceptibility gene CLEC16A. We also confirm interaction between rs4774 and HLA-DRB1*15:01 such that individuals carrying the risk allele for rs4774 and HLA-DRB1*15:01 have a higher than expected risk for MS. In conclusion, our findings support previous data that variability in the CIITA gene affects MS risk, but also that the effect is modulated by MS-associated HLA haplotypes. These findings further underscore the biological importance of HLA for MS risk.Genes and Immunity advance online publication, 16 January 2014; doi:10.1038/gene.2013.71.
|
|
| 2. |
- Sedimbi, S. K., et al.
(författare)
-
SUMO4 M55V polymorphism affects susceptibility to type I diabetes in HLA DR3- and DR4-positive Swedish patients
- 2007
-
Ingår i: Genes Immun. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 8:6, s. 518-21
-
Tidskriftsartikel (refereegranskat)abstract
- SUMO4 M55V, located in IDDM5, has been a focus for debate because of its association to type I diabetes (TIDM) in Asians but not in Caucasians. The current study aims to test the significance of M55V association to TIDM in a large cohort of Swedish Caucasians, and to test whether M55V is associated in those carrying human leukocyte antigen (HLA) class II molecules. A total of 673 TIDM patients and 535 age- and sex-matched healthy controls were included in the study. PCR-RFLP was performed to identify the genotype and allele variations. Our data suggest that SUMO4 M55V is not associated with susceptibility to TIDM by itself. When we stratified our patients and controls based on heterozygosity for HLA-DR3/DR4 and SUMO4 genotypes, we found that presence of SUMO4 GG increased further the relative risk conferred by HLA-DR3/DR4 to TIDM, whereas SUMO4 AA decreased the risk. From the current study, we conclude that SUMO4 M55V is associated with TIDM in association with high-risk HLA-DR3 and DR4, but not by itself.
|
|
| 3. |
- Landin-Olsson, Mona, et al.
(författare)
-
Immunoreactive trypsin(Ogen) in the sera of children with recent-onset insulin-dependent diabetes and matched controls
- 1990
-
Ingår i: Pancreas. - : Ovid Technologies (Wolters Kluwer Health). - 0885-3177. ; 5:3, s. 241-247
-
Tidskriftsartikel (refereegranskat)abstract
- To evaluate the exocrine pancreatic function at the time of diagnosis of insulin-dependent diabetes mellitus, we determined immunoreactive an-odal and cathodal trypsin(ogen) levels in sera from almost all children (n = 375) 0-14 years of age in Sweden in whom diabetes developed during 1 year, and in sex-, age-, and geographically matched control subjects (n = 312). The median level of anodal trypsin(ogen) was 5 (quartile range, 3-7) µg/L in children with newly diagnosed diabetes, compared with a median level of 7 (quartile range, 4-8) µg/L in control subjects (p < 0.0001). Similarly, the median level of cathodal trypsin(ogen) was 8 (quartile range, 4-10) µg/L in children with diabetes, compared with a median level of 11 (quartile range, 7-15) µg/L in control subjects (p < 0.0001). The median of the individual ratios between cathodal and anodal trypsin(ogen) was 1.4 in the diabetic patients and 1.7 in the control children (p < 0.001). In a multivariate test, however, only the decrease in cathodal trypsin(ogen) concentration was associated with diabetes. The levels of trypsin(ogen)s did not correlate with levels of islet cell antibodies, present in 81% of the diabetic children. Several mechanisms may explain our findings, for example, similar pathogenetic factors may affect both the endocrine and exocrine pancreas simultaneously, a failing local trophic stimulation by insulin on the exocrine cells may decrease the trypsinogen production, and there may be an increased elimination of trypsin(ogen) because of higher filtration through the kidneys in the hyperglycemic state.
|
|
| 4. |
- Axfors, Cathrine, et al.
(författare)
-
Association between convalescent plasma treatment and mortality in COVID-19 : a collaborative systematic review and meta-analysis of randomized clinical trials
- 2021
-
Ingår i: BMC Infectious Diseases. - : BioMed Central (BMC). - 1471-2334. ; 21:1
-
Forskningsöversikt (refereegranskat)abstract
- Background: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, ). Methods: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I-2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.
|
|
| 5. |
- Sanjeevi, Carani B., et al.
(författare)
-
The risk conferred by HLA-DR and DQ for type 1 diabetes in 0-35-year age group are different in different regions of Sweden
- 2008
-
Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. - 9781573317337 ; 1150, s. 106-11
-
Tidskriftsartikel (refereegranskat)abstract
- HLA DR4-DQ8 and DR3-DQ2 haplotypes account for 89% of newly diagnosed cases of type 1 diabetes (T1D) in Sweden. The presence of a single copy of DQ6 confers protection. The aim of the present study is to evaluate whether the risk conferred by high risk HLA DR and DQ to T1D is similar in all regions of Sweden and see whether there are any significant regional differences. The subjects comprised 799 consecutively diagnosed T1D patients and 585 age-, sex-, and geography-matched healthy controls in the age group 0-35 years. HLA typing for high-risk haplotypes was previously performed using PCR-SSOP and RFLP. The results showed that HLA DR3-DR4 gave an odds ratio of 8.14 for the whole of Sweden. However, when the study group was divided into six geographical regions, subjects from Stockholm had the highest OR, followed by those from Lund, Linköping, Gothenburg, Umeå, and Uppsala. Absolute protection was conferred by the presence of DQ6 in subjects from the Linköping region, but varied in the other regions. The frequency of DR3 and DQ2, DR4 and DQ8, DR15, and DQ6 in patients showed high linkage for each region, but were different between regions. In conclusion: The risk conferred by high-risk HLA varies in different regions for a homogenous population in Sweden. The results highlight the important role played by the various environmental factors in the precipitation of T1D.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Sun, Chengjun, et al.
(författare)
-
CRYAB-650 C>G (rs2234702) affects susceptibility to type 1 diabetes and IAA-positivity in Swedish population
- 2012
-
Ingår i: Human Immunology. - : Elsevier. - 0198-8859 .- 1879-1166. ; 73:7, s. 759-766
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Single nucleotide polymorphisms (SNPs) in the promoter region of CRYAB gene have been associated with in multiple sclerosis. CRYAB gene, which encodes alpha B-crystallin (a member of small heat shock protein), was reported as a potential autoimmune target. In this study we investigated whether SNPs in the promoter region of CRYAB gene were also important in the etiology of Type 1 diabetes (T1D).METHODS: Genotyping of SNPs in the promoter region of CRYAB gene was performed in a Swedish cohort containing 444 T1D patients and 350 healthy controls. Three SNPs were included in this study: CRYAB-652 A>G (rs762550), -650 C>G (rs2234702) and -249 C > G (rs14133). Two SNPs (CRYAB-652 and -650) were not included in previous genome wide association studies.RESULTS: CRYAB-650 (rs2234702)*C allele was significantly more frequent in patients than in controls (OR = 1.48, Pc = 0.03). CRYAB-650*C allele was associated with IAA positivity (OR = 8.17, Pc < 0.0001) and IA-2A positivity (OR = 2.14, Pc = 0.005) in T1D patients. This association with IAA was amplified by high-risk HLA carrier state (OR = 10.6, P < 0.0001). No association was found between CRYAB-650 and other autoantibody positivity (GADA and ICA). CRYAB haplotypes were also associated with IAA and IA-2A positivity (highest OR = 2.07 and 2.11, respectively), these associations remain in high HLA-risk T1D patients.CONCLUSIONS: CRYAB-650 was associated with T1D in the Swedish cohort we studied. CRYAB-650*C allele might confers susceptibility to the development of T1D. CRYAB-650 was also associated with the development of IAA-positivity in T1D patients, especially in those carrying T1D high-risk HLA haplotypes.
|
|
| 9. |
- Uusitupa, M., et al.
(författare)
-
Effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile and inflammation markers in metabolic syndrome : a randomized study (SYSDIET)
- 2013
-
Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 274:1, s. 52-66
-
Tidskriftsartikel (refereegranskat)abstract
- Background Different healthy food patterns may modify cardiometabolic risk. We investigated the effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile, blood pressure and inflammatory markers in people with metabolic syndrome. Methods We conducted a randomized dietary study lasting for 18-24weeks in individuals with features of metabolic syndrome (mean age 55years, BMI 31.6kgm-2, 67% women). Altogether 309 individuals were screened, 200 started the intervention after 4-week run-in period, and 96 (proportion of dropouts 7.9%) and 70 individuals (dropouts 27%) completed the study, in the Healthy diet and Control diet groups, respectively. Healthy diet included whole-grain products, berries, fruits and vegetables, rapeseed oil, three fish meals per week and low-fat dairy products. An average Nordic diet served as a Control diet. Compliance was monitored by repeated 4-day food diaries and fatty acid composition of serum phospholipids. Results Body weight remained stable, and no significant changes were observed in insulin sensitivity or blood pressure. Significant changes between the groups were found in non-HDL cholesterol (-0.18, mmolL-1 95% CI -0.35; -0.01, P=0.04), LDL to HDL cholesterol (-0.15, -0.28; -0.00, P=0.046) and apolipoprotein B to apolipoprotein A1 ratios (-0.04, -0.07; -0.00, P=0.025) favouring the Healthy diet. IL-1 Ra increased during the Control diet (difference -84, -133; -37ngL-1, P= 0.00053). Intakes of saturated fats (E%, beta estimate 4.28, 0.02; 8.53, P=0.049) and magnesium (mg, -0.23, -0.41; -0.05, P=0.012) were associated with IL-1 Ra. Conclusions Healthy Nordic diet improved lipid profile and had a beneficial effect on low-grade inflammation.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Landin-Olsson, M., et al.
(författare)
-
Islet cell and thyrogastric antibodies in 633 consecutive 15- to 34-yr-old patients in the diabetes incidence study in Sweden
- 1992
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 41:8, s. 1022-1027
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of age on ICA and thyrogastric antibodies at diagnosis of IDDM was evaluated in 633 consecutively diagnosed Swedish diabetic patients aged 15-34 yr and in 282 volunteers of the same age. ICAs were present in 61% (383 of 633) of the patients and in 2% (5 of 282) of control subjects. When the initial classification was considered, ICAs were detected in 69% (327 of 473) of patients with IDDM, 23% (19 of 83) of those with NIDDM, 50% (36 of 72) of those with unclassifiable diabetes, and 20% (1 of 5) of those with secondary diabetes. The frequency of ICA fell significantly (P < 0.001) with age in IDDM patients from 77% (104/135) in those 15-19 yr old to 52% (50 of 96) in 30- to 34-yr-old IDDM patients. The low frequency of ICA in 30- to 34-yr-old IDDM patients was confined to men (42%, 28 of 66). The frequency of gastric (H+, K+-ATPase) antibodies was significantly (P < 0.05) higher in IDDM patients (10%, 47 of 449) than in patients with NIDDM (3%, 3 of 80) and unclassifiable diabetes (4%, 3 of 72). In conclusion, the frequency of ICA at the diagnosis of IDDM in young adult subjects decreases with increasing age, particularly in men. The frequent finding of ICA in patients considered to have NIDDM or unclassifiable diabetes indicates that misclassification of diabetes is frequent in young adult patients recently diagnosed with diabetes.
|
|
| 14. |
- Landin-Olsson, M, et al.
(författare)
-
Predictive value of islet cell and insulin autoantibodies for type 1 (insulin-dependent) diabetes mellitus in a population-based study of newly-diagnosed diabetic and matched control children
- 1992
-
Ingår i: Diabetologia. - 0012-186X. ; 35:11, s. 73-1068
-
Tidskriftsartikel (refereegranskat)abstract
- Most studies evaluating immune markers for prediction of Type 1 (insulin-dependent) diabetes mellitus have focused on first degree relatives, although only 10% of newly-diagnosed patients have an affected first degree relative. The Swedish Childhood Diabetes Register identifies 99% of all diabetic children at diagnosis. In this population-based study, islet cell antibodies and insulin autoantibodies in 0-14-year-old Swedish consecutively-diagnosed patients and control subjects were analysed to define their sensitivity and specificity. Over 16 months (1986-1987), 515 Swedish children developed diabetes. Plasma samples were obtained from 494 (96%) patients, and 420 matched control children. Among patients, the frequency of islet cell antibodies was 84% (415 of 494), insulin autoantibodies 43% (145 of 334); 40% (135 of 334) were positive for both and 88% (294 of 334) were positive for one or both. Among control children, 3% (14 of 420) had islet cell antibodies, 1% (4 of 390) insulin autoantibodies, and 4% (16 of 390) had either autoantibody marker. The predictive value of finding a patient with the disease was only 7% since 4% of the control children were antibody-positive and the cumulative incidence rate up to 15 years of age is 0.38%. None of the autoantibody-positive (n = 21) or negative control children developed diabetes during 3 to 5 years of follow-up. Longitudinal investigations of islet cell or insulin-autoantibody-positive healthy children are necessary to accurately determine the conversion rate from marker positivity to disease onset.
|
|
| 15. |
|
|
| 16. |
- Magnusdottir, O. K., et al.
(författare)
-
Plasma alkylresorcinols C17:0/C21:0 ratio, a biomarker of relative whole-grain rye intake, is associated to insulin sensitivity : a randomized study
- 2014
-
Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 68:4, s. 453-458
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/OBJECTIVES: Few studies have used biomarkers of whole-grain intake to study its relation to glucose metabolism. We aimed to investigate the association between plasma alkylresorcinols (AR), a biomarker of whole-grain rye and wheat intake, and glucose metabolism in individuals with metabolic syndrome (MetS). SUBJECTS/METHODS: Participants were 30-65 years of age, with body mass index 27-40 kg/m(2) and had MetS without diabetes. Individuals were recruited through six centers in the Nordic countries and randomized to a healthy Nordic diet (ND, n=96), rich in whole-grain rye and wheat, or a control diet (n=70), for 18-24 weeks. In addition, associations between total plasma AR concentration and C17:0/C21:0 homolog ratio as an indication of the relative whole-grain rye intake, and glucose metabolism measures from oral glucose tolerance tests were investigated in pooled (ND + control) regression analyses at 18/24 weeks. RESULTS: ND did not improve glucose metabolism compared with control diet, but the AR C17:0/C21:0 ratio was inversely associated with fasting insulin concentrations (P=0.002) and positively associated with the insulin sensitivity indices Matsuda ISI (P=0.026) and disposition index (P=0.022) in pooled analyses at 18/24 weeks, even after adjustment for confounders. The AR C17:0/C21:0 ratio was not significantly associated with insulin secretion indices. Total plasma AR concentration was not related to fasting plasma glucose or fasting insulin at 18/24 weeks. CONCLUSIONS: The AR C17:0/C21:0 ratio, an indicator of relative whole-grain rye intake, is associated with increased insulin sensitivity in a population with MetS.
|
|
| 17. |
- Petruzzo, P., et al.
(författare)
-
VCA in the Era of the COVID-19 Pandemic
- 2022
-
Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 106:4, s. 690-692
-
Tidskriftsartikel (refereegranskat)
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Törn, C., et al.
(författare)
-
Prognostic factors for the course of beta cell function in autoimmune diabetes
- 2000
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 85:12, s. 4619-4623
-
Tidskriftsartikel (refereegranskat)abstract
- This study presents a 2-yr follow-up of 281 patients, aged 15-34 yr, diagnosed with diabetes between 1992 and 1993. At diagnosis, 224 (80%) patients were positive for at least one of the following autoantibodies: islet cell antibodies (ICAs), glutamic acid decarboxylase antibodies (GADAs), or tyrosine phosphatase antibodies (IA-2As), the remaining 57 (20%) patients were negative for all three autoantibodies. At diagnosis, C-peptide levels were lower (0.27, 0.16-0.40 nmol/L) in autoantibody-positive patients compared with autoantibody-negative patients (0.51, 0.28-0.78 nmol/L, P < 0.001). After 2 yr, C-peptide levels had decreased significantly in patients with autoimmune diabetes (0.20, 0.10-0.37 nmol/L, P = 0.0018), but not in autoantibody-negative patients. In patients with autoimmune diabetes, a low initial level of C-peptide (odds ratio, 2.6, 95% confidence interval, 1.7-4.0) and a high level of GADAs (odds ratio, 2.5, 95% confidence interval, 1.1-5.7) were risk factors for a C-peptide level below the reference level of 0.25 nmol/L 2 yr after diagnosis. Body mass index had a significant effect in the multivariate analysis only when initial C-peptide was not considered. Factors such as age, gender, levels of ICA or IA-2A or insulin autoantibodies (analyzed in a subset of 180 patients) had no effect on the decrease in ▀-cell function. It is concluded that the absence of pancreatic islet autoantibodies at diagnosis were highly predictive for a maintained ▀-cell function during the 2 yr after diagnosis, whereas high levels of GADA indicated a course of decreased ▀-cell function with low levels of C-peptide. In autoimmune diabetes, an initial low level of C-peptide was a strong risk factor for a decrease in ▀-cell function and conversely high C-peptide levels were protective. Other factors such as age, gender, body mass index, levels of ICA, IA-2A or IAA had no prognostic importance.
|
|
| 21. |
|
|
| 22. |
- Wendt, M, et al.
(författare)
-
Long-Term Survival and Recurrence in Oropharyngeal Squamous Cell Carcinoma in Relation to Subsites, HPV, and p16-Status
- 2021
-
Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 13:11
-
Tidskriftsartikel (refereegranskat)abstract
- Long-term survival data in relation to sub-sites, human papillomavirus (HPV), and p16INK4a (p16) for patients with oropharyngeal squamous cell carcinoma (OPSCC) is still sparse. Furthermore, reports have indicated atypical and late recurrences for patients with HPV and p16 positive OPSCC. Therefore, we assessed long-term survival and recurrence in relation to oropharyngeal subsite and HPV/p16 status. A total of 529 patients with OPSCC, diagnosed in the period 2000–2010, with known HPVDNA and p16-status, were included. HPV/p16 status and sub-sites were correlated to disease-free and overall survival (DFS and OS respectively). The overexpression of p16 (p16+) is associated with significantly better long-term OS and DFS in tonsillar and base of tongue carcinomas (TSCC/BOTSCC), but not in patients with other OPSCC. Patients with HPVDNA+/p16+ TSCC/BOTSCC presented better OS and DFS compared to those with HPVDNA−/p16− tumors, while those with HPVDNA−/p16+ cancer had an intermediate survival. Late recurrences were rare, and significantly more frequent in patients with p16− tumors, while the prognosis after relapse was poor independent of HPVDNA+/−/p16+/− status. In conclusion, patients with p16+ OPSCC do not have more late recurrences than p16−, and a clear prognostic value of p16+ was only observed in TSCC/BOTSCC. Finally, the combination of HPVDNA and p16 provided superior prognostic information compared to p16 alone in TSCC/BOTSCC.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Östman, Jan, et al.
(författare)
-
Ketoacidosis in young adults is not related to the islet antibodies at the diagnosis of Type 1 diabetes mellitus - A nationwide study
- 2000
-
Ingår i: Diabetic Medicine. - : Wiley. - 0742-3071 .- 1464-5491. ; 17, s. 269-
-
Tidskriftsartikel (refereegranskat)abstract
- Aims: To test the hypothesis that there is lower prevalence of islet antibodies in subjects with newly diagnosed Type 1 diabetes mellitus in young adulthood than in children is associated with less severe diabetes at time of diagnosis. Methods: This investigation was based on a nationwide study (Diabetes Incidence Study in Sweden) of 15-34-year-old newly diagnosed diabetic subjects. During 1992-1993, all diabetic subjects (excluding secondary and gestational diabetes) were reported on standardized forms, with information about clinical characteristics at diagnosis. The study examined islet cell antibodies (ICA) by indirect immunofluorescence, and autoantibodies to glutamic acid decarboxylase (GADA), tyrosine phosphatase- like antigen (IA-2A) and insulin (IAA) as well as C-peptide by radioimmunoassay. Results: Blood samples were available from 78 patients with diabetic ketoacidosis (DKA) and 517 non-acidotic patients. The prevalence of ICA (63% vs. 57%), GADA (63% vs. 66%), IA-2A (35% vs. 44%) and IAA (20% vs. 15%) were very similar in patients with or without DKA. The median levels of the four autoantibodies did not differ between the two groups. High blood glucose (P < 0.001) and low C-peptide levels (P < 0.001) were the only parameters found to be related to DKA. Conclusions: The similarities in findings of newly diagnosed diabetic patients with or without DKA regarding ICA, GADA, IA-2A and IAA suggest that there is no relationship between the expression of antigenicity and the severity of β-cell dysfunction. The lower prevalence of the four autoantibodies in 15-34-year-old diabetic subjects compared with previous findings in children is not explained by misclassification of diabetes type.
|
|
| 27. |
- Agardh, Daniel, et al.
(författare)
-
HLA-DQB1*0201/0302 is associated with severe retinopathy in patients with IDDM
- 1996
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 39:11, s. 1313-1317
-
Tidskriftsartikel (refereegranskat)abstract
- Some insulin-dependent diabetic (IDDM) patients develop severe forms of retinopathy. Putative risk factors such as hypertension, poor metabolic control, nephropathy and growth hormone levels do not fully explain the progress of retinopathy in these patients. It has been discussed whether there is a genetic marker, since some diabetic patients without any known predisposing risk factors develop severe retinopathy and others do not. In the present study, HLA-DR and DQ were compared in two patient groups with IDDM. One group consisted of patients with early-onset diabetes, with severe non-proliferative or proliferative retinopathy; the other group had no or only mild signs of retinopathy. High resolution HLA typing was carried out by polymerase chain reaction (PCR) and hybridization with allele specific probes. Alleles on the DR3-DQ2 haplotype, DRB1*0301, DQA1*0501 and DQB1*0201, were more frequent in patients with severe retinopathy. A difference was seen when combining certain alleles in the genotypes of DQA1*03/0501 (p > 0.05) and DQB1*0201/0302 (p < 0.01). The findings of the present study suggest that DQB1*0201/0302 is the strongest genetic marker for severe retinopathy and DRB1*0301/0401 only has a secondary influence when combined with this genotype. It seems as if IDDM patients who are positive for the genotype DR3-DQ2/DR4-DQ8 (DRB1*0301-DQA1*0501-DQB1*0201/DRB1*0401 -DQA1*03-DQB1*0302) are at greater risk of developing severe retinopathy.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Berglund, Erik, et al.
(författare)
-
Clinical Significance of Alloantibodies in Hand Transplantation : A Multicenter Study
- 2019
-
Ingår i: Transplantation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0041-1337 .- 1534-6080. ; 103:10, s. 2173-2182
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Donor-specific antibodies (DSAs) have a strong negative correlation with long-term survival in solid organ transplantation. Although the clinical significance of DSA and antibody-mediated rejection (AMR) in upper extremity transplantation (UET) remains to be established, a growing number of single-center reports indicate their presence and potential clinical impact. Methods. We present a multicenter study assessing the occurrence and significance of alloantibodies in UET in reference to immunological parameters and functional outcome. Results. Our study revealed a high prevalence and early development of de novo DSA and non-DSA (43%, the majority detected within the first 3 postoperative y). HLA class II mismatch correlated with antibody development, which in turn significantly correlated with the incidence of acute cellular rejection. Cellular rejections preceded antibody development in almost all cases. A strong correlation between DSA and graft survival or function cannot be statistically established at this early stage but a correlation with a lesser outcome seems to emerge. Conclusions. While the phenotype and true clinical effect of AMR remain to be better defined, the high prevalence of DSA and the correlation with acute rejection highlight the need for optimizing immunosuppression, close monitoring, and the relevance of an HLA class II match in UET recipients.
|
|
| 31. |
- Bryllert, Tomas, et al.
(författare)
-
Designed emitter states in resonant tunneling through quantum dots
- 2002
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 80:15, s. 2681-2683
-
Tidskriftsartikel (refereegranskat)abstract
- Resonant tunneling through a single layer of self-assembled quantum dots (QDs) is compared to tunneling through two layers of vertically aligned (stacked) dots. The difference can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. The temperature dependence of current peaks originating in tunneling through individual QDs and individual stacks is used to clarify this point. In addition, we show that the statistical size distribution of self-assembled quantum dots causing the inhomogeneous broadening in luminescence experiments can be analyzed in a resonant tunneling experiment. (C) 2002 American Institute of Physics.
|
|
| 32. |
- Bryllert, Tomas, et al.
(författare)
-
Resonant tunneling through coupled self-assembled quantum dots and the influence of inhomogeneous broadening
- 2002
-
Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
-
Konferensbidrag (refereegranskat)abstract
- Resonant tunneling through a single layer of self-assembled quantum dots (QDs) as well as tunneling through two layers of vertically aligned (stacked) dots is investigated. The difference between single and double layers of QDs can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. By fabricating small-area devices we are able to probe single stacks of quantum dots, revealing details of the coupling between the stacked dots. Very sharp resonances, with peak-to-valley ratios of several hundred, have been measured in the current-voltage characteristics. We also show that the statistical size distribution of self-assembled quantum dots causing the inhomogeneous broadening in luminescence experiments can be analysed in a resonant tunneling experiment
|
|
| 33. |
- Colldén, Hannah, et al.
(författare)
-
Comprehensive Sex Steroid Profiling in Multiple Tissues Reveals Novel Insights in Sex Steroid Distribution in Male Mice
- 2022
-
Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 163:3
-
Tidskriftsartikel (refereegranskat)abstract
- A comprehensive atlas of sex steroid distribution in multiple tissues is currently lacking, and how circulating and tissue sex steroid levels correlate remains unknown. Here, we adapted and validated a gas chromatography tandem mass spectrometry method for simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione, progesterone (Prog), estradiol, and estrone in mouse tissues. We then mapped the sex steroid pattern in 10 different endocrine, reproductive, and major body compartment tissues and serum of gonadal intact and orchiectomized (ORX) male mice. In gonadal intact males, high levels of DHT were observed in reproductive tissues, but also in white adipose tissue (WAT). A major part of the total body reservoir of androgens (T and DHT) and Prog was found in WAT. Serum levels of androgens and Prog were strongly correlated with corresponding levels in the brain while only modestly correlated with corresponding levels in WAT. After orchiectomy, the levels of the active androgens T and DHT decreased markedly while Prog levels in male reproductive tissues increased slightly. In ORX mice, Prog was by far the most abundant sex steroid, and, again, WAT constituted the major reservoir of Prog in the body. In conclusion, we present a comprehensive atlas of tissue and serum concentrations of sex hormones in male mice, revealing novel insights in sex steroid distribution. Brain sex steroid levels are well reflected by serum levels and WAT constitutes a large reservoir of sex steroids in male mice. In addition, Prog is the most abundant sex hormone in ORX mice.
|
|
| 34. |
- Colldén, Hannah, et al.
(författare)
-
Dehydroepiandrosterone Supplementation Results in Varying Tissue-specific Levels of Dihydrotestosterone in Male Mice
- 2022
-
Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 163:12
-
Tidskriftsartikel (refereegranskat)abstract
- Dehydroepiandrosterone (DHEA), an adrenal androgen precursor, can be metabolized in target tissues into active sex steroids. It has been proposed that DHEA supplementation might result in restoration of physiological local sex steroid levels, but knowledge on the effect of DHEA treatment on local sex steroid levels in multiple tissues is lacking. To determine the effects of DHEA on tissue-specific levels of sex steroids, we treated orchiectomized (ORX) male mice with DHEA for 3 weeks and compared them with vehicle-treated ORX mice and gonadal intact mice. Intra-tissue levels of sex steroids were analyzed in reproductive organs (seminal vesicles, prostate, m. levator ani), major body compartments (white adipose tissue, skeletal muscle, and brain), adrenals, liver, and serum using a sensitive and validated gas chromatography-mass spectrometry method. DHEA treatment restored levels of both testosterone (T) and dihydrotestosterone (DHT) to approximately physiological levels in male reproductive organs. In contrast, this treatment did not increase DHT levels in skeletal muscle or brain. In the liver, DHEA treatment substantially increased levels of T (at least 4-fold) and DHT (+536%, P < 0.01) compared with vehicle-treated ORX mice. In conclusion, we provide a comprehensive map of the effect of DHEA treatment on intra-tissue sex steroid levels in ORX mice with a restoration of physiological levels of androgens in male reproductive organs while DHT levels were not restored in the skeletal muscle or brain. This, and the unexpected supraphysiological androgen levels in the liver, may be a cause for concern considering the uncontrolled use of DHEA.
|
|
| 35. |
- Faxén Irving, Karlström Brita, Landin I-L, Rothenberg E, Överby E.
(författare)
-
Mat och kostråd inom äldrevården.
- 1998
-
Ingår i: Uppsala: Statens Livsmedelsverk Manuskript.
-
Annan publikation (övrigt vetenskapligt/konstnärligt)
|
|
| 36. |
- Graham, J, et al.
(författare)
-
Genetic effects on age-dependent onset and islet cell autoantibody markers in type 1 diabetes
- 2002
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 51:5, s. 1346-1355
-
Tidskriftsartikel (refereegranskat)abstract
- Age-dependent associations between type 1 diabetes risk genes HLA, INS VNTR, and CTLA-4 and autoantibodies to GAD65 (GADAs), ICA512/IA-2, insulin, and islet cells were determined by logistic regression analysis in 971 incident patients with type 1 diabetes and 702 control subjects aged 0–34 years. GADAs were associated with HLA-DQ2 in young but not in older patients (P = 0.009). Autoantibodies to insulin were negatively associated with age (P < 0.0001) but positively associated with DQ8 (P = 0.03) and with INS VNTR (P = 0.04), supporting possible immune tolerance induction. ICA512/IA-2 were negatively associated with age (P < 0.0001) and with DQ2 (P < 0.0001) but positively associated with DQ8 (P = 0.04). Males were more likely than females to be negative for GADA (P < 0.0001), autoantibodies to islet cells (P = 0.04), and all four autoantibody markers (P = 0.004). The CTLA-4 3′ end microsatellite marker was not associated with any of the autoantibodies. We conclude that age and genetic factors such as HLA-DQ and INS VNTR need to be combined with islet autoantibody markers when evaluating the risk for type 1 diabetes development.
|
|
| 37. |
- Grubin, C. E., et al.
(författare)
-
A novel radioligand binding assay to determine diagnostic accuracy of isoform-specific glutamic acid decarboxylase antibodies in childhood IDDM
- 1994
-
Ingår i: Diabetologia. - 0012-186X. ; 37:4, s. 344-350
-
Tidskriftsartikel (refereegranskat)abstract
- Insulin-dependent diabetes mellitus (IDDM) is associated with autoreactivity against GAD but the diagnostic sensitivity (positivity in disease) and specificity (negativity in health) of isoform-specific GAD antibodies have yet to be defined in assay systems suitable for screening large number of samples. One set of IDDM patient (n=10) and control (n=50) standard sera were used to develop quantitative antibody assays with in vitro synthesized recombinant 35S-methionine-labelled GAD65 and GAD67, respectively, and protein A-Sepharose to separate free from antibody-bound ligand. Binding levels were not normally distributed (p<0.0001) and therefore, the diagnostic accuracy of GAD antibodies was analysed by the ROC plots in population-based, consecutively-diagnosed, recent onset, 0-14 year-old patients (n=105), and matched, healthy control subjects (n=157). The ROC plots showed that the diagnostic sensitivity of GAD65 antibodies was 77% and the specificity 92% compared with 8% and 98%, respectively for GAD67 antibodies. In the IDDM sera, GAD65 and GAD67 antibodies were concordant in 7% (6 of 81) and GAD65 antibodies and ICA in 89% (72 of 81) without a correlation between the autoantibody levels. Autoantibodies to recombinant human islet GAD65 are specific and sensitive markers for childhood IDDM in this immunoassay with in vitro synthesized 35S-methioninelabelled recombinant GAD.
|
|
| 38. |
- Gupta, M, et al.
(författare)
-
Coxsackie virus B antibodies are increased in HLA DR3-MICA5.1 positive type 1 diabetes patients in the Linkoping region of Sweden
- 2003
-
Ingår i: Human Immunology. - 0198-8859. ; 64:9, s. 874-879
-
Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes mellitus (T1DM) is an autoimmune disorder in which genetics and environmental factors play a role. Among the environmental factors, viruses (especially Coxsackie virus B [CBV]), and among genetic markers, human leukocyte antigen (HLA) DRB1*04-DQA1*0301-DQB1*0302 (DR4-DQ8) and DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2), and major histocompatibility complex class I chain-related gene-A (MICA) alleles 5 and 5.1 have been reported to be associated with T1DM in Caucasians. Sweden ranks third in the world for T1DM incidence. In Sweden, the Linkoping region indicates the highest incidence for T1DM. In this study, we analyzed whether antibodies against CBV are increased in DR3, DR4, MICA5, or MICA5.1 positive patients from Linkoping (n = 46) and from Swedish population as a whole (n = 298) between the age of 0 and 15 years old. There was no difference in the frequency of antibodies to CBV in patients compared with controls in Linkoping (26% vs 23%) or in all of Sweden (26% vs 21%). However, CBV antibodies were increased in DR3, DR3-DR4 (heterozygous), DR3-MICA5.1, and DR3-DR4-MICA5.1 positive compared with DR3, DR3-DR4, DR3-MICA5.1, and DR3-DR4-MICA5.1 negative patients in Linkoping (p < 0.05 for all), but not in Swedish population as a whole. Thus, our study suggests that in addition to DR3, MICA5.1 has an influence on the immune response to CBV infection in patients from Linkoping. (C) American Society for Histocompatibility and Immunogenetics, 2003. Published by Elsevier Inc.
|
|
| 39. |
|
|
| 40. |
- Gyllenberg, A, et al.
(författare)
-
Age-dependent variation of genotypes in MHC II transactivator gene (CIITA) in controls and association to type 1 diabetes
- 2012
-
Ingår i: Genes and Immunity. - Stockholm : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 76:2, s. 202-203
-
Tidskriftsartikel (refereegranskat)abstract
- The major histocompatibility complex class II transactivator (CIITA) gene (16p13) has been reported to associate with susceptibility to multiple sclerosis, rheumatoid arthritis and myocardial infarction, recently also to celiac disease at genome-wide level. However, attempts to replicate association have been inconclusive. Previously, we have observed linkage to the CIITA region in Scandinavian type 1 diabetes (T1D) families. Here we analyze five Swedish T1D cohorts and a combined control material from previous studies of CIITA. We investigate how the genotype distribution within the CIITA gene varies depending on age, and the association to T1D. Unexpectedly, we find a significant difference in the genotype distribution for markers in CIITA (rs11074932, P=4 × 10(-5) and rs3087456, P=0.05) with respect to age, in the collected control material. This observation is replicated in an independent cohort material of about 2000 individuals (P=0.006, P=0.007). We also detect association to T1D for both markers, rs11074932 (P=0.004) and rs3087456 (P=0.001), after adjusting for age at sampling. The association remains independent of the adjacent T1D risk gene CLEC16A. Our results indicate an age-dependent variation in CIITA allele frequencies, a finding of relevance for the contrasting outcomes of previously published association studies.
|
|
| 41. |
- Hagman, A., et al.
(författare)
-
Obstetric Outcomes in Women With Turner Karyotype EDITORIAL COMMENT
- 2012
-
Ingår i: Obstetrical and Gynecological Survey. - 0029-7828. ; 67:4, s. 228-229
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- There is concern over the high risk of cardiovascular complications, hypertensive disorders, and other adverse obstetric outcomes among pregnant women with Turner syndrome (TS). A diagnosis of TS is made in some women late in life or not at all. Spontaneous pregnancies are rare in women with TS and are associated with a high rate of complications, especially miscarriage. The use of assisted reproductive techniques is an option for these women; pregnancy and implantation rates after oocyte donation in women with TS seem to be comparable with those without TS who need this treatment. Few data are available on obstetric outcome in pregnant women with TS. The aim of this retrospective population-based cohort study was to compare maternal and neonatal outcomes among singleton pregnancies of women with and without TS. Data on births occurring between 1973 and 2007 from the Swedish Genetic Turner Register and the Swedish Medical Birth Register were cross-linked. Obstetric outcome in infants born to women with TS was compared with a reference group of 56,000 women from the general population. Mean gestational age and birth weight were adjusted for maternal age. Outcome in TS women with twins was described separately. A total of 115 women with TS gave birth to 208 children (202 singletons and 3 sets of twins) during the study period. The TS diagnosis was unknown in 52% of the women before the first delivery. Women in the TS group were older at the first delivery than women in the reference group; median age was 30 years and 26 years, respectively (P < 0.0001). There was a trend toward more women with TS having preeclampsia during their first pregnancy (6.3 vs. 3.0%; P = 0.07). One woman suffered from an aortic dissection during her second spontaneous pregnancy. Compared with the reference group, the median gestational age was shorter in children in the TS group (-6.4 days, P = 0.0067), and median birth weight was lower (-208 g, P = 0.001); however, no significant difference was found in median standard deviation scores for weight and length at birth. The rate of cesarean delivery was higher in the TS group than in the reference group (35.6% vs. 11.8%, respectively, P < 0.0001). There was no significant difference in birth defects between groups. These findings show that women with a TS karyotype have mostly favorable obstetric outcomes. Singletons of women with TS have a shorter gestational age but a similar size at birth. The data also show no difference in birth defects between women with and without TS.
|
|
| 42. |
|
|
| 43. |
- Hillman, M., et al.
(författare)
-
Skim milk powder with high content of Maillard reaction products affect weight gain, organ development and intestinal inflammation in early life in rats
- 2019
-
Ingår i: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915. ; 125, s. 78-84
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The intestinal tract is important for development of immune tolerance and disturbances are suggested to trigger autoimmune disorders. The aim of this study was to explore the effect of Maillard products in skim milk powder obtained after long storage, compared to fresh skim milk powder. Methods: Young rats were weaned onto a diet based on skim milk powder with high concentration of Maillard products (HM-SM, n = 18) or low (C-SM, n = 18) for one week or four weeks. Weekly body weight and feed consumption were noted. At the end, organ weights, intestinal histology, permeability and inflammatory cytokines were evaluated. Results: Rats fed with HM-SM had after one week, 15% less weight gain than controls, despite equal feed intake. After one week thymus and spleen were smaller, intestinal mucosa thickness was increased and acute inflammatory cytokines (IL-17, IL-1β, MCP-1) were elevated. After four weeks, cytokines associated with chronic intestinal inflammation (fractalkine, IP-10, leptin, LIX, MIP-2, RANTES and VEGF) were increased in rats fed with HM-SM compared to C-SM. Conclusion: High content of Maillard products in stored milk powder caused an intestinal inflammation. Whether this is relevant for tolerance development and future autoimmune diseases remains to be explored.
|
|
| 44. |
|
|
| 45. |
|
|
| 46. |
- Jensen, R., et al.
(författare)
-
Islet cell autoantibody levels after the diagnosis of young adult diabetic patients
- 2007
-
Ingår i: Diabetic Medicine. - : Wiley. - 0742-3071 .- 1464-5491. ; 24:11, s. 1221-1228
-
Tidskriftsartikel (refereegranskat)abstract
- Aims The aim was to determine the course of islet cell antibodies [glutamate decarboxylase (GADA), tyrosine phosphatase-like islet antigen 2 (IA-2A) and islet cell (ICA)] after the diagnosis of the diabetic patient. Methods The Diabetes Incidence Study in Sweden (DISS) attempted to prospectively enrol all newly diagnosed diabetic patients aged 15–34 years during 1992 and 1993. C-peptide and autoantibody levels were determined from venous blood samples at diagnosis and again at yearly intervals for 6 years. Results After the first year, the odds of remaining GADA positive decreased by 9% per year [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.85–0.96] while the mean GADA index remained unchanged ( = 0.8, P = 0.37). There was no change in the percentage of subjects testing IA-2A positive after the first year ( = 0.1, P = 0.75). However, the mean index decreased 0.04 per year (95% CI: 0.03–0.05)—a 7.9% decline (95% CI: 5.4–10.4%). The odds of a subject testing positive for ICA decreased by 24% per year (OR = 0.76, 95% CI = 0.70–0.82). The mean ICA levels decreased 0.75 per year (95% CI: 0.66–0.84)—a 16.4% decline (95% CI: 14.1–18.6%). The rate of change in titres for all three autoantibodies was independent of gender, human leucocyte antigen genotype and C-peptide status. Conclusions GADA levels remained high while ICA levels declined. In contrast to a previous study, we found that the proportion of IA-2A subjects remaining positive did not decrease after the first year, while the average index decreased slightly.
|
|
| 47. |
- Johansson, J O, et al.
(författare)
-
Long-term treatment with growth hormone decreases plasminogen activator inhibitor-1 and tissue plasminogen activator in growth hormone-deficient adults.
- 1996
-
Ingår i: Thrombosis and haemostasis. - 0340-6245. ; 76:3, s. 422-8
-
Tidskriftsartikel (refereegranskat)abstract
- The syndrome of growth hormone deficiency (GHD) in adults is associated with premature atherosclerosis, increased cardiovascular mortality, abnormal lipoprotein patterns and abnormal body composition. We have previously shown that GH-deficient adults have increased concentrations of fibrinogen and plasminogen activator inhibitor (PAI-1) activity. The aim of the present investigation was to study coagulation and fibrinolysis in 17 patients with adult-onset GHD during two years of treatment with recombinant human GH (12 micrograms/kg body weight/day). The impact of the contemporary changes in metabolic variables and body composition on coagulation and fibrinolysis was studied. The patients received conventional thyroid, adrenal and gonadal hormone replacement therapy. PAI-1 activity, PAI-1 antigen and tissue plasminogen activator (t-PA) antigen levels decreased during the GH treatment period (p < 0.05). The decrease was more pronounced in patients with high pre-treatment levels of the different variables. alpha 2-antiplasmin decreased (p < 0.05), while plasminogen was unchanged during two years of GH treatment. Fibrinogen concentrations tended to decrease after two years of GH treatment (p = 0.06), while the coagulation factors VII and VIII were unchanged. von Willebrand factor demonstrated a transient decrease after 18 months of GH treatment. The coagulation inhibitor, protein C, decreased (p < 0.05), while antithrombin was unchanged. Fasting plasma insulin increased (p < 0.01), but blood glucose did not differ after two years of GH treatment. Serum high-density lipoprotein cholesterol, total cholesterol and triglycerides were unaltered. Body fat decreased during the initial GH treatment but was unaltered after two years, while lean body mass increased (p < 0.001) and the waist over hip circumference ratio tended to decrease (p = 0.06). In conclusion, PAI-1 activity, PAI-1 antigen and t-PA antigen decreased during long-term GH treatment. These changes may be a direct effect of GH itself or may be secondary to the favourable changes in body composition. It remains to be seen whether changes in these fibrinolytic variables during rhGH treatment reduces the cardiovascular risk in patients with GHD. The present results suggest that GH plays a role in the regulation of fibrinolysis.
|
|
| 48. |
- Järrendahl, Kenneth, et al.
(författare)
-
Polarization of Light Reflected from Chiral Structures - Calculations Compared with Mueller Matrix Ellipsometry Measurements on Natural and Synthetic Samples
- 2012
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Mueller matrix elements mij representing the polarization response from a nanostructured materialis determined by the constituent materials optical properties and the superstructure. Here, we investigate how chiral structures in form of helicoidally stacked uniaxial layers determine mij as a functionof polarization state, wavelength, incidence angle and azimuthal angle of the incoming light. The studied parameters include the layer materials ordinary/extraordinary optical properties, Euler angle values, and layer thickness as well as the thickness and pitch of the helicoidal superstructure. Sub- and superstructure inhomogeneity is also introduced. From the Fresnel-based calculations, mij aswell as the degree of polarization, ellipticity and azimuth of the polarization ellipse are obtained and presented as contour and trace plots to give a complete view of the polarization behavior. The results from the calculations are compared with Mueller matrix spectroscopic ellipsometry measurements of both natural and synthesized helicoidal structures. The measurements were performed with a dualrotating compensator system (RC2, J.A. Woollam Co., Inc.) for wavelengths in the range from 245 to 1000 nm and incident angles from 20 to 75°. For some measurements the azimuthal angle of the incident light was varied. The investigated natural chiral structures were exoskeletons from several beetles in the scarab subfamilies Cetoniinae and Rutelinae. As predicted from the calculations it isobserved that the reflection from these beetles can have a high degree of polarization and high ellipticity (near-circular polarization). Both left- and right-polarization was observed. The synthesized structures are helicoidal nanorods of Al1−xInxN grown on sapphire substrates with metal-nitride seedlayers using UHV magnetron sputtering. Due to an internal composition gradient (a variation of x) in the crystalline structure, the nanorods will tilt away from the substrate normal. Helicoidal structures can thus be obtained by rotating the substrate around its normal during deposition. Samples with different pitch and layer thickness with right-handed as well as left-handed chirality were grown. Also for these structures both left and right near-circular polarized light is observed. By combining calculations, ellipsometry measurements and scanning electron microscopy characterization we get agood input to build layered models of the natural and synthetic samples. After regression fitting agood agreement between calculated and measured optical data were obtained.
|
|
| 49. |
- Jönsson, Christina, et al.
(författare)
-
Microplastics shedding from textiles-developing analytical method for measurement of shed material representing release during domestic washing
- 2018
-
Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 10:7
-
Tidskriftsartikel (refereegranskat)abstract
- The topic of shedding of micro-sized polymeric particles, so called microplastics, from textiles has been covered by an increasing number of studies over the past years. However, the methods with which the shedding of microplastics from textiles has been measured so far has shown a large variation. Consequently, the results regarding the amount of shed particles also vary, from 120 to 728,289 particles from similar garments in recent studies. This article presents research enabling for identification of whether the shedding of microplastics from different types of fabric was dependent on construction parameters. As none of the methods in the existing literature could be used for evaluating shedding of microplastics from textiles, a method was developed for this purpose. The resulting final method is described in this paper as well as the work with minimizing the error sources and consequently the standard deviation of the results through selection of material samples, equipment and procedure for sample preparation, washing, filtering the washing water and analyzing the shed microplastics. Comparing the environmental load of different garments, or identifying improvement possibilities in garment construction are two examples of how the method can be utilized.
|
|
| 50. |
|
|
