| 1. |
- Haghighi, Mona, et al.
(författare)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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| 2. |
- Lundgren, Markus, et al.
(författare)
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Analgesic antipyretic use among young children in the TEDDY study : No association with islet autoimmunity
- 2017
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Ingår i: BMC Pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The use of analgesic antipyretics (ANAP) in children have long been a matter of controversy. Data on their practical use on an individual level has, however, been scarce. There are indications of possible effects on glucose homeostasis and immune function related to the use of ANAP. The aim of this study was to analyze patterns of analgesic antipyretic use across the clinical centers of The Environmental Determinants of Diabetes in the Young (TEDDY) prospective cohort study and test if ANAP use was a risk factor for islet autoimmunity. Methods: Data were collected for 8542 children in the first 2.5 years of life. Incidence was analyzed using logistic regression with country and first child status as independent variables. Holm's procedure was used to adjust for multiplicity of intercountry comparisons. Time to autoantibody seroconversion was analyzed using a Cox proportional hazards model with cumulative analgesic use as primary time dependent covariate of interest. For each categorization, a generalized estimating equation (GEE) approach was used. Results: Higher prevalence of ANAP use was found in the U.S. (95.7%) and Sweden (94.8%) compared to Finland (78.1%) and Germany (80.2%). First-born children were more commonly given acetaminophen (OR 1.26; 95% CI 1.07, 1.49; p = 0.007) but less commonly Non-Steroidal Anti-inflammatory Drugs (NSAID) (OR 0.86; 95% CI 0.78, 0.95; p = 0.002). Acetaminophen and NSAID use in the absence of fever and infection was more prevalent in the U.S. (40.4%; 26.3% of doses) compared to Sweden, Finland and Germany (p < 0.001). Acetaminophen or NSAID use before age 2.5 years did not predict development of islet autoimmunity by age 6 years (HR 1.02, 95% CI 0.99-1.09; p = 0.27). In a sub-analysis, acetaminophen use in children with fever weakly predicted development of islet autoimmunity by age 3 years (HR 1.05; 95% CI 1.01-1.09; p = 0.024). Conclusions: ANAP use in young children is not a risk factor for seroconversion by age 6 years. Use of ANAP is widespread in young children, and significantly higher in the U.S. compared to other study sites, where use is common also in absence of fever and infection.
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| 3. |
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| 4. |
- Corman, Thierry, et al.
(författare)
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Burst technology with feedback-loop control for capacitive detection and electrostatic excitation of resonant silicon sensors
- 2000
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Ingår i: IEEE Transactions on Electron Devices. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9383 .- 1557-9646. ; 47:11, s. 2228-2235
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Tidskriftsartikel (refereegranskat)abstract
- A method for excitation and detection of resonant silicon sensors based on discontinuous, burst excitation is presented. The solution eliminates the crosstalk between electrostatic excitation and capacitive detection by separating them in time. High excitation voltages can be combined with highly sensitive detection electronics. The method facilitates the use of large distances between the resonator and electrodes used for elicitation and detection. The method was successfully tested with feedback-loop control on silicon resonant density and pressure sensors where the electrodes were positioned outside a glass, Continuous measurements of gas pressures and liquid densities were realized, The simplified fabrication process utilized reduces the risk of leakage from the ambient pressure to the low-pressure cavities in which the resonators are encapsulated since electrical feedthroughs are not needed, Excitation voltages alternating between 0 and 150 V could be applied to the resonators with measured electronics sensitivities of 0.4 fF Signal-to-noise ratios (SNRs) as high as 100 (density sensor) and 360 (pressure sensor) were obtained. The electronic evaluation revealed that the burst duty cycle (i.e,, the excitation time relative to the free oscillation time) had a strong influence on the output detection voltage, As few as two excitation periods with a burst cycle frequency of 115 Hz and a burst duty cycle of 1% was sufficient to select and lock the resonance frequency (28 042 Hz) for the tested pressure sensor. The same electrodes could be used for both excitation and detection, A novel solution is also presented that eliminates the charging effect of dielectric surfaces which otherwise can be a problem for capacitive detection.
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| 5. |
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| 6. |
- Dahlin, Anna M., 1979-, et al.
(författare)
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A genome-wide association study on medulloblastoma
- 2020
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Ingår i: Journal of Neuro-Oncology. - : Springer. - 0167-594X .- 1573-7373. ; 147:2, s. 309-315
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Medulloblastoma is a malignant embryonal tumor of the cerebellum that occurs predominantly in children. To find germline genetic variants associated with medulloblastoma risk, we conducted a genome-wide association study (GWAS) including 244 medulloblastoma cases and 247 control subjects from Sweden and Denmark.Methods: Genotyping was performed using Illumina BeadChips, and untyped variants were imputed using IMPUTE2.Results: Fifty-nine variants in 11 loci were associated with increased medulloblastoma risk (p < 1 × 10–5), but none were statistically significant after adjusting for multiple testing (p < 5 × 10–8). Thirteen of these variants were genotyped, whereas 46 were imputed. Genotyped variants were further investigated in a validation study comprising 249 medulloblastoma cases and 629 control subjects. In the validation study, rs78021424 (18p11.23, PTPRM) was associated with medulloblastoma risk with OR in the same direction as in the discovery cohort (ORT = 1.59, pvalidation = 0.02). We also selected seven medulloblastoma predisposition genes for investigation using a candidate gene approach: APC, BRCA2, PALB2, PTCH1, SUFU, TP53, and GPR161. The strongest evidence for association was found for rs201458864 (PALB2, ORT = 3.76, p = 3.2 × 10–4) and rs79036813 (PTCH1, ORA = 0.42, p = 2.6 × 10–3).Conclusion: The results of this study, including a novel potential medulloblastoma risk loci at 18p11.23, are suggestive but need further validation in independent cohorts.
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| 7. |
- Driscoll, Kimberly A., et al.
(författare)
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SAI-CH-6 : Development of a Short Form of the State Anxiety Inventory for Children At-Risk for Type 1 Diabetes
- 2023
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Ingår i: Journal of Pediatric Psychology. - 0146-8693. ; 48:10, s. 861-869
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To develop a reliable and valid short form of the State Anxiety Subscale of the State-Trait Anxiety Inventory for Children (STAI-CH) in the Environmental Determinants of Diabetes in the Young (TEDDY) study. Methods: A Development Sample of 842 10-year-old TEDDY children completed the STAI-CH State Subscale about their type 1 diabetes (T1D) risk. The best 6 items (three anxiety-present and three anxiety-absent) for use in a short form (SAI-CH-6) were identified via item-total correlations. SAI-CH-6 reliability was examined in a Validation Sample (n = 257) of children who completed the full 20-item STAI-CH State Subscale and then again in an Application Sample (n = 2,710) who completed only the SAI-CH-6. Expected associations between the children's SAI-CH-6 scores and country of residence, sex, T1D family history, accuracy of T1D risk perception, worry about getting T1D, and their parents' anxiety scores were examined. Results: The SAI-CH-6 was reliable (α = 0.81-0.87) and highly correlated with the full 20-item STAI-CH State Subscale (Development Sample: r = 0.94; Validation Sample: r = 0.92). SAI-CH-6 scores detected significant differences in state anxiety symptoms associated with T1D risk by country, T1D family history, accuracy of T1D risk perception, and worry about getting T1D and were correlated with the child's parent's anxiety. Conclusion: The SAI-CH-6 appears useful for assessing children's state anxiety symptoms when burden and time limitations prohibit the use of the STAI-CH. The utility of the SAI-CH-6 in older children with and without chronic conditions needs to be assessed.
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| 8. |
- Gao, Hong, et al.
(författare)
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The landscape of tolerated genetic variation in humans and primates
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648
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Tidskriftsartikel (refereegranskat)abstract
- Personalized genome sequencing has revealed millions of genetic differences between individuals, but our understanding of their clinical relevance remains largely incomplete. To systematically decipher the effects of human genetic variants, we obtained whole-genome sequencing data for 809 individuals from 233 primate species and identified 4.3 million common protein-altering variants with orthologs in humans. We show that these variants can be inferred to have nondeleterious effects in humans based on their presence at high allele frequencies in other primate populations. We use this resource to classify 6% of all possible human protein-altering variants as likely benign and impute the pathogenicity of the remaining 94% of variants with deep learning, achieving state-of-the-art accuracy for diagnosing pathogenic variants in patients with genetic diseases.
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| 9. |
- Johnson, Randi K., et al.
(författare)
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Metabolite-related dietary patterns and the development of islet autoimmunity
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The role of diet in type 1 diabetes development is poorly understood. Metabolites, which reflect dietary response, may help elucidate this role. We explored metabolomics and lipidomics differences between 352 cases of islet autoimmunity (IA) and controls in the TEDDY (The Environmental Determinants of Diabetes in the Young) study. We created dietary patterns reflecting pre-IA metabolite differences between groups and examined their association with IA. Secondary outcomes included IA cases positive for multiple autoantibodies (mAb+). The association of 853 plasma metabolites with outcomes was tested at seroconversion to IA, just prior to seroconversion, and during infancy. Key compounds in enriched metabolite sets were used to create dietary patterns reflecting metabolite composition, which were then tested for association with outcomes in the nested case-control subset and the full TEDDY cohort. Unsaturated phosphatidylcholines, sphingomyelins, phosphatidylethanolamines, glucosylceramides, and phospholipid ethers in infancy were inversely associated with mAb+ risk, while dicarboxylic acids were associated with an increased risk. An infancy dietary pattern representing higher levels of unsaturated phosphatidylcholines and phospholipid ethers, and lower sphingomyelins was protective for mAb+ in the nested case-control study only. Characterization of this high-risk infant metabolomics profile may help shape the future of early diagnosis or prevention efforts. © 2019, The Author(s).
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| 10. |
- Johnson, Suzanne Bennett, et al.
(författare)
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The association of physical activity to oral glucose tolerance test outcomes in multiple autoantibody positive children : The TEDDY Study
- 2022
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Ingår i: Pediatric Diabetes. - : Hindawi Limited. - 1399-543X .- 1399-5448. ; 23:7, s. 1017-1026
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine the association of physical activity (PA), measured by accelerometry, to hemoglobin AIC (HbA1c) and oral glucose tolerance test (OGTT) outcomes in children who were multiple persistent confirmed autoantibody positive for type 1 diabetes (T1D). Methods: The Environmental Determinants of Diabetes in the Young (TEDDY) multinational study followed children from birth. Children ≥3 years of age who were multiple persistent confirmed autoantibody positive were monitored by OGTTs every 6 months. TEDDY children's PA was measured by accelerometry beginning at 5 years of age. We examined the relationship between moderate plus vigorous (mod + vig) PA, HbA1c, and OGTT in 209 multiple autoantibody children who had both OGTT and PA measurements. Results: Mod + vig PA was associated with both glucose and C-peptide measures (fasting, 120-min, and AUC); higher mod + vig PA was associated with a better OGTT response primarily in children with longer duration of multiple autoantibody positivity. Mod + vig PA also interacted with child age; lower mod + vig PA was associated with a greater increase in C-peptide response across age. Mod + vig PA was not related to fasting insulin, HOMA-IR or HbA1c. Conclusions: The OGTT is the gold standard for diabetes diagnosis and is used to monitor those at high risk for T1D. We found higher levels of mod + vig PA were associated with better OGTT outcomes in children ≥5 years of age who have been multiple autoantibody positive for longer periods of time. Physical activity should be the focus of future efforts to better understand the determinants of disease progression in high-risk children.
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| 11. |
- Krischer, Jeffrey P, et al.
(författare)
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Predicting Islet Cell Autoimmunity and Type 1 Diabetes : An 8-Year TEDDY Study Progress Report
- 2019
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 42:6, s. 1051-1060
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Assessment of the predictive power of The Environmental Determinants of Diabetes in the Young (TEDDY)-identified risk factors for islet autoimmunity (IA), the type of autoantibody appearing first, and type 1 diabetes (T1D).RESEARCH DESIGN AND METHODS: A total of 7,777 children were followed from birth to a median of 9.1 years of age for the development of islet autoantibodies and progression to T1D. Time-dependent sensitivity, specificity, and receiver operating characteristic (ROC) curves were calculated to provide estimates of their individual and collective ability to predict IA and T1D.RESULTS: HLA genotype (DR3/4 vs. others) was the best predictor for IA (Youden's index J = 0.117) and single nucleotide polymorphism rs2476601, in PTPN22, was the best predictor for insulin autoantibodies (IAA) appearing first (IAA-first) (J = 0.123). For GAD autoantibodies (GADA)-first, weight at 1 year was the best predictor (J = 0.114). In a multivariate model, the area under the ROC curve (AUC) was 0.678 (95% CI 0.655, 0.701), 0.707 (95% CI 0.676, 0.739), and 0.686 (95% CI 0.651, 0.722) for IA, IAA-first, and GADA-first, respectively, at 6 years. The AUC of the prediction model for T1D at 3 years after the appearance of multiple autoantibodies reached 0.706 (95% CI 0.649, 0.762).CONCLUSIONS: Prediction modeling statistics are valuable tools, when applied in a time-until-event setting, to evaluate the ability of risk factors to discriminate between those who will and those who will not get disease. Although significantly associated with IA and T1D, the TEDDY risk factors individually contribute little to prediction. However, in combination, these factors increased IA and T1D prediction substantially.
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| 12. |
- Kuderna, Lukas F. K., et al.
(författare)
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A global catalog of whole-genome diversity from 233 primate species
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648, s. 906-913
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Tidskriftsartikel (refereegranskat)abstract
- The rich diversity of morphology and behavior displayed across primate species provides an informative context in which to study the impact of genomic diversity on fundamental biological processes. Analysis of that diversity provides insight into long-standing questions in evolutionary and conservation biology and is urgent given severe threats these species are facing. Here, we present high-coverage wholegenome data from 233 primate species representing 86% of genera and all 16 families. This dataset was used, together with fossil calibration, to create a nuclear DNA phylogeny and to reassess evolutionary divergence times among primate clades. We found within-species genetic diversity across families and geographic regions to be associated with climate and sociality, but not with extinction risk. Furthermore, mutation rates differ across species, potentially influenced by effective population sizes. Lastly, we identified extensive recurrence of missense mutations previously thought to be human specific. This study will open a wide range of research avenues for future primate genomic research.
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| 13. |
- Kuderna, Lukas F. K., et al.
(författare)
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Identification of constrained sequence elements across 239 primate genomes
- 2024
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 625:7996, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- Noncoding DNA is central to our understanding of human gene regulation and complex diseases1,2, and measuring the evolutionary sequence constraint can establish the functional relevance of putative regulatory elements in the human genome3,4,5,6,7,8,9. Identifying the genomic elements that have become constrained specifically in primates has been hampered by the faster evolution of noncoding DNA compared to protein-coding DNA10, the relatively short timescales separating primate species11, and the previously limited availability of whole-genome sequences12. Here we construct a whole-genome alignment of 239 species, representing nearly half of all extant species in the primate order. Using this resource, we identified human regulatory elements that are under selective constraint across primates and other mammals at a 5% false discovery rate. We detected 111,318 DNase I hypersensitivity sites and 267,410 transcription factor binding sites that are constrained specifically in primates but not across other placental mammals and validate their cis-regulatory effects on gene expression. These regulatory elements are enriched for human genetic variants that affect gene expression and complex traits and diseases. Our results highlight the important role of recent evolution in regulatory sequence elements differentiating primates, including humans, from other placental mammals.
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| 14. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Impact of Menstrual Function on Hormonal Response to Repeated Bouts of Intense Exercise
- 2019
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 10, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Strenous exercise stimulates the hypothalamic-pituitary (HP) axis in order to ensure homeostasis and promote anabolism. Furthermore, exercise stimulates a transient increase in the neurotrophin brain-derived neurotrophic factor (BDNF) suggested to mediate the anxiolytic effects of exercise. Athletes with secondary functional hypothalamic amenorrhea (FHA) have been reported to have lower BDNF, and a blunted HP axis response to exercise as athletes with overtraining syndrome. Aim: The aim of the study was to investigate the hormonal and BDNF responses to a two-bout maximal exercise protocol with four hours of recovery in between in FHA and eumenorrheic (EUM) athletes. Methods: Eumenorrheic (n = 16) and FHA (n = 14) endurance athletes were recruited from national teams and competitive clubs. Protocols included gynecological examination; body composition (DXA); 7-day assessment of energy availability; blood sampling pre and post the two exercises tests. Results: There were no differences between groups in hormonal responses to the first exercise bout. After the second exercise bout IGFBP-3 increased more in FHA compared with EUM athletes (2.1 +/- 0.5 vs. 0.6 +/- 0.6 mu g/L, p = 0.048). There were non-significant trends toward higher increase in IGF-1 (39.3 +/- 4.3 vs. 28.0 +/- 4.6 mu g/L, p = 0.074), BDNF (96.5 +/- 22.9 vs. 34.4 +/- 23.5 mu g/L, p = 0.058), GH to cortisol ratio (0.329 +/- 0.010 vs. 0.058 +/- 0.010, p = 0.082), and decrease in IGF-1 to IGFBP-3 ratio (-2.04 +/- 1.2 vs. 0.92 +/- 1.22, p = 0.081) in athletes with FHA compared with EUM athletes. Furthermore, there was a non-significant trend toward a higher increase in prolactin to cortisol ratio in EUM athletes compared with athletes with FHA (0.60 +/- 0.15 vs. 0.23 +/- 0.15, p = 0.071). No differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function were found. Conclusion: No major differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function could be detected.
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| 15. |
- Melin, Jessica, et al.
(författare)
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A fast passive and planar liquid sample micromixer
- 2004
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Ingår i: Lab on a Chip. - : RSC Publishing. - 1473-0197 .- 1473-0189. ; 4:3, s. 214-219
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Tidskriftsartikel (refereegranskat)abstract
- A novel microdevice for passively mixing liquid samples based on surface tension and a geometrical mixing chamber is presented. Due to the laminar flow regime on the microscale, mixing becomes difficult if not impossible. We present a micromixer where a constantly changing time dependent flow pattern inside a two sample liquid plug is created as the plug simply passes through the planar mixer chamber. The device requires no actuation during mixing and is fabricated using a single etch process. The effective mixing of two coloured liquid samples is demonstrated.
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| 16. |
- Melin, Jessica, et al.
(författare)
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A LIQUID-TRIGGERED LIQUID MICROVALVE
- 2003
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Ingår i: 12th IEEE International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCERS 2003). - NEW YORK : IEEE conference proceedings. - 0780377311 ; , s. 1562-1565
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Konferensbidrag (refereegranskat)abstract
- This work introduces a novel surface tension and geometry based liquid-triggered liquid microvalve for on-chip liquid control. The simultaneous presence of two liquid plugs at the uncomplicated valve junction triggers the further movement of the liquids and overcomes the stop valve function of the device, thereby providing a precise means of timing liquid movement on-chip. The structure was shown to successfully function and forms the basis for several novel and useful functions, including fluidic AND gates, contactless on-chip liquid sample control, timing of independent processes on the same microchip, bubble-free joining of liquids, all of which pose great challenges in the area of microfluidics.
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| 17. |
- Melin, Jessica, et al.
(författare)
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A liquid-triggered liquid microvalve for on-chip flow control
- 2004
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 100:3, s. 463-468
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Tidskriftsartikel (refereegranskat)abstract
- This work introduces a novel surface tension and geometry based liquid-triggered liquid microvalve for on-chip liquid flow control. The simultaneous presence of two liquid plugs at the uncomplicated valve junction triggers the further movement of the liquids and overcomes the stop valve function of the device, thereby providing a precise means of timing liquid movement on-chip. The generic structure was shown to successfully function and forms the basis for several novel and useful functions, including fluidic AND gates, contactless on-chip liquid sample control, timing of independent processes on the same microchip, bubble-free joining of liquids, all of which pose great challenges in the area of microfluidics. The device may be applied to chemical analysis, drug discovery, medical diagnostics and biochemistry.
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| 18. |
- Melin, Jessica, et al.
(författare)
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A low-pressure encapsulated deep reactive ion etched resonant pressure sensor electrically excited and detected using 'burst' technology
- 2000
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 10:2, s. 209-217
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Tidskriftsartikel (refereegranskat)abstract
- A purely silicon resonant pressure sensor fabricated using deep reactive ion etching (DRIE) and encapsulated at low pressure by two glass lids is presented. The sensor consists of a vibrating dual-diaphragm capsule suspended at four points in a fixed frame. The support beams an hollow and act as pressure inlet ports. As the ambient gas pressure changes, the resonator shape changes, thereby changing its resonance frequency. The sensor integrates corner holes and is encapsulated at low pressure to reduce squeezed-film damping effects between the resonating structure and the glass lid. The sensor is electrostatically excited into a balanced mode of oscillation and capacitively detected using a novel 'burst' technology. This technique is based on independently exciting the structure and detecting the resulting output frequency at separate periods in time. Several sizes and design variations of the sensor have been fabricated and evaluated. Measurements show the smallest structure (5 mm membrane diameter width) to have a Q factor of 14 000 after low-pressure encapsulation, pressure sensitivity of 15 ppm/mbar(-1) over the range 0.1-1500 mbar, and expected temperature sensitivity of -34 ppm degrees C-1. The structure had a resonance frequency of 35 078 Hz in atmospheric air pressure. If higher sensitivity is desired, a larger sensor can be chosen (140 ppm/mbar(-1) for a sensor with a 10 mm wide membrane), however, at the expense of a lower Q factor.
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| 19. |
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| 20. |
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| 21. |
- Melin, Jessica, et al.
(författare)
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Behaviour and design considerations for continuous flow closed-open-closed liquid microchannels
- 2005
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 5:6, s. 682-686
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Tidskriftsartikel (refereegranskat)abstract
- This paper introduces a method of combining open and closed microchannels in a single component in a novel way which couples the benefits of both open and closed microfluidic systems and introduces interesting on-chip microfluidic behaviour. Fluid behaviour in such a component, based on continuous pressure driven flow and surface tension, is discussed in terms of cross sectional flow behaviour, robustness, flow-pressure performance, and its application to microfluidic interfacing. The closed-open-closed microchannel possesses the versatility of upstream and downstream closed microfluidics along with open fluidic direct access. The device has the advantage of eliminating gas bubbles present upstream when these enter the open channel section. The unique behaviour of this device opens the door to applications including direct liquid sample interfacing without the need for additional and bulky sample tubing.
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| 22. |
- Melin, Jessica, et al.
(författare)
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Factors assessed in the first year of a longitudinal study predict subsequent study visit compliance : the TEDDY study
- 2023
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Ingår i: European Journal of Medical Research. - 0949-2321. ; 28:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Compliance with a study protocol is central to meeting its research goals. In longitudinal research studies, data loss due to missed visits limit statistical power and introduce bias. The Environmental Determinants of Diabetes in the Young (TEDDY) study is a longitudinal multinational (US, Finland, Germany, and Sweden) investigation of children at risk for type 1 diabetes (T1D) that seeks to identify the environmental triggers of islet autoimmunity and T1D. The purpose of the current study was to identify sociodemographic variables and maternal characteristics assessed in the first year of TEDDY that were associated with study visit compliance in the subsequent 3 years. Methods: Sociodemographic variables, maternal life-style behaviors, post-partum depression, maternal reactions to the child’s T1D risk, and study-related variables were collected at child-age 6 months and 15 months. Multiple linear regression was used to examine the association of these variables to study visit compliance in the subsequent 3 years. Results: Study visit compliance was highest in Sweden (p > 0.001), in children who were their mother’s first child (p > 0.001), and whose mothers were older (p > 0.001) and more satisfied with the TEDDY study (p > 0.001). Father participation was also associated with better study visit compliance (p > 0.001). In contrast, children whose mothers smoked (p > 0.001), suffered from post-partum depression (p = 0.034), and were more anxious about their child’s T1D risk (p = 0.002), completed fewer visits. Father’s study satisfaction was also associated with study visit compliance (p = 0.029); however, it was not significant in models that included maternal study satisfaction. Conclusions: Sociodemographic variables, maternal characteristics—including study satisfaction—and fathers’ participation in the first year of a longitudinal study were associated with subsequent study visit compliance in a sample of children genetically at-risk for T1D followed for 4 years. This information can inform future strategies designed to improve study visit compliance in longitudinal pediatric studies. Trial registration: NCT00279318, 06/09/2004.
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| 23. |
- Melin, Jessica, et al.
(författare)
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Is staff consistency important to parents' satisfaction in a longitudinal study of children at risk for type 1 diabetes : the TEDDY study
- 2022
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Ingår i: BMC Endocrine Disorders. - : Springer Science and Business Media LLC. - 1472-6823. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Participants' study satisfaction is important for both compliance with study protocols and retention, but research on parent study satisfaction is rare. This study sought to identify factors associated with parent study satisfaction in The Environmental Determinants of Diabetes in the Young (TEDDY) study, a longitudinal, multinational (US, Finland, Germany, Sweden) study of children at risk for type 1 diabetes. The role of staff consistency to parent study satisfaction was a particular focus. METHODS: Parent study satisfaction was measured by questionnaire at child-age 15 months (5579 mothers, 4942 fathers) and child-age four years (4010 mothers, 3411 fathers). Multiple linear regression analyses were used to identify sociodemographic factors, parental characteristics, and study variables associated with parent study satisfaction at both time points. RESULTS: Parent study satisfaction was highest in Sweden and the US, compared to Finland. Parents who had an accurate perception of their child's type 1 diabetes risk and those who believed they can do something to prevent type 1 diabetes were more satisfied. More educated parents and those with higher depression scores had lower study satisfaction scores. After adjusting for these factors, greater study staff change frequency was associated with lower study satisfaction in European parents (mothers at child-age 15 months: - 0.30,95% Cl - 0.36, - 0.24, p < 0.001; mothers at child-age four years: -0.41, 95% Cl - 0.53, - 0.29, p < 0.001; fathers at child-age 15 months: -0.28, 95% Cl - 0.34, - 0.21, p < 0.001; fathers at child-age four years: -0.35, 95% Cl - 0.48, - 0.21, p < 0.001). Staff consistency was not associated with parent study satisfaction in the US. However, the number of staff changes was markedly higher in the US compared to Europe. CONCLUSIONS: Sociodemographic factors, parental characteristics, and study-related variables were all related to parent study satisfaction. Those that are potentially modifiable are of particular interest as possible targets of future efforts to improve parent study satisfaction. Three such factors were identified: parent accuracy about the child's type 1 diabetes risk, parent beliefs that something can be done to reduce the child's risk, and study staff consistency. However, staff consistency was important only for European parents. TRIAL REGISTRATION: NCT00279318 .
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| 24. |
- Melin, Jessica, 1975-
(författare)
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Novel Microsystem Techniques for Liquid Manipulation and Pressure Sensing
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Scaling down operations and functions into the fascinating micro world not only improve performance, lower costs, and enable easier integration, but also opens the door to new functionalities. This truly multidisciplinary thesis presents novel solutions to current and relevant challenges in the areas of 1) on-chip liquid manipulation which has applications in micro total analysis systems, medical diagnostics, and drug discovery and 2) pressure sensing which has an established market in the automotive and industrial processes industry. Especially in the area of liquid manipulation, the aim was to take advantage of forces and properties dominating on the micro scale whenever possible, rather than compensating for these effects, and to create solutions with universal appeal and application areas. In the area of liquid manipulation, this thesis discusses a novel method of passively synchronizing liquid movement on-chip based on liquid surface tension and device geometry. This technique has potential applications in timing independent processes, liquid-liquid interactions, and digitizing liquid movement. A fast and passive discrete sample micromixer is also presented based on the same principles. A unique way of direct access, bubble tolerant sample interfacing with flow-through microfluidics using a closed-open-closed channel is also introduced. This method can be used to regulate flow on-chip without the need for any moving parts or electrical contact. Moreover, work is presented on two types of out-of-plane electrospray ionization mass spectrometry (ESI-MS) emitter tips which mimic ideal mass spectrometry tips. Fabrication of these tips is uncomplicated and results in robust structures with good performance. In the field of pressure sensing, this thesis investigates a form based resonating principle. The Q factor of the sensor is improved by low pressure encapsulation and structure design. A novel technique for excitation and detection of resonant microsensors using 'burst' technology is also demonstrated. This method involves temporally separating excitation and detection, thereby eliminating crosstalk and the need for electrical feedthroughs. It also allows high voltages to be used with sensitive circuitry and a single electrode to be used for both excitation and detection.
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| 25. |
- Melin, Jessica, et al.
(författare)
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Parental anxiety after 5 years of participation in a longitudinal study of children at high risk of type 1 diabetes
- 2020
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Ingår i: Pediatric Diabetes. - : Hindawi Limited. - 1399-543X .- 1399-5448. ; 21:5, s. 878-889
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Parents of children participating in screening studies may experience increased levels of anxiety. The aim of this study was to assess parental anxiety levels after 5 years of participation in the Diabetes Prediction in Skåne study. Associations between parental anxiety about their child developing type 1 diabetes and clinical, demographic, and immunological factors were analyzed. Method: Mothers and fathers of participating 5-year-old children answered a questionnaire regarding parental anxiety associated with their child's increased risk of type 1 diabetes. Anxiety levels were assessed using the State Anxiety Inventory scale. Data were analyzed using logistic and multinomial regression. Results: Parents of 2088 5-year-old children participated. Both parents answered the questionnaire for 91.2% (n = 1904) of children. In 67.1% of families, neither parent reported being anxious that their child had an increased risk of developing type 1 diabetes. Anxiety was higher in mothers of children positive for autoantibodies (OR 2.21 95% CI 1.41, 3.48, P <.001) and those perceiving their child had a higher risk for type 1 diabetes (2.01; 1.29, 3.13, P =.002). Frequency of worry was associated with parental anxiety (mothers 5.33; 3.48, 8.17, P <.001, fathers 5.27; 3.51, 7.92, P <.001). Having a family member with type 1 diabetes and having lower education level were also associated with increased anxiety. Conclusions: Diabetes in the family, the child's autoantibody status, education level, frequency of worry and risk perception where associated with higher parental anxiety. These findings add to our understanding of the impact of screening for type 1 diabetes in children on parental anxiety.
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