Publikationer från Linköpings universitet
Not a member yet
58266 research outputs found
Sort by
Understanding and Addressing the Performance Asymmetry Issue in Semitransparent Laminated Organic Photovoltaic Devices
No full textOrganic photovoltaics (OPVs) offer a promising solution for indoor energy harvesting. However, fundamental investigations to understand and optimize industrial processes such as roll-to-roll lamination for upscaling remain limited. This study investigates a critical failure mode in the upscaling of OPVs. One major challenge for thick semitransparent laminated OPV devices is current-voltage (J-V) asymmetry, where performance under cathode-side illumination exceeds that under anode-side illumination. X-ray reflectivity, neutron reflectivity, and drift-diffusion simulations reveal that a vertically stratified polymer-rich region within the bulk of photoactive layers is the main cause of asymmetric J-V characteristics. Based on this fundamental understanding, a model is proposed to explain the mechanism, wherein electron extraction is hindered by the polymer-rich region during anode illumination. By exploring upscaling-compatible blends, cathode/anode-balanced, high-performing, and air-stable semitransparent laminated OPVs are developed for indoor applications using commercially available PV-X-plus material. These findings provide valuable guidance for designing OPVs with balanced performance, facilitating roll-to-roll adoption and commercialization.Funding Agencies|Vetenskapsrdet [ID20-0105]; Swedish Foundation for Strategic Research (SSF) [PH2022-0029]; Royal Academy of Sciences Physics grant [2019-04837_VR]; Swedish Research Council, VR</p
Effects of rotigotine on sleep in Parkinson's disease patients: a Parkinson's KinetiGraph study
No full textIntroduction: Recent studies suggest that the dopamine agonist (DA) rotigotine improves sleep among Parkinson disease (PD) patients. Parkinson's KinetiGraph (PKG) offers a home-based alternative for evaluating sleep. We investigated the effect of rotigotine on sleep in PD patients with PKG and questionnaires. Secondarily, the effects of rotigotine on daytime sleepiness, motor symptoms, quality of life and correlations between PKG variables and rating scale results were investigated. Method: Thirty-two PD patients with sleep disturbances (Clinical Global Impression-Severity (CGI-S) &gt;= 3) were included in this observational study. Before start of treatment and during stable dose with rotigotine patients were assessed with Parkinson's disease sleep scale 2 (PDSS-2), Epworth Sleepiness Scale (ESS), Parkinson's disease quality of life questionnaire (PDQ-8), European Quality of life five dimensions (EQ-5D-5L) questionnaires and PKG recordings (24 h/day for 6 days). Clinicians evaluated sleep using CGI scales, and PD severity using Clinical Impression of Severity Index for Parkinson's Disease (CISI-PD). Results: Rotigotine did not significantly improve total PDSS-2 or PKG nighttime scores in the entire group, but PDSS-2 improved among patients with PDSS-2 &gt;= 18 at baseline and for DA-na & iuml;ve patients (p = 0.009 and p = 0.013). Treatment improved percent time tremor (PTT; p &lt; 0.001), percent time immobile during daytime (PTID; p &lt; 0.001), CISI-PD (p &lt; 0.001), PDQ-8 (p = 0.014), and EQ-5D-5L (p = 0.002). No significant correlations were found between PTID and ESS-total (rho = -0.046, p = 0.718) or between combined sleep score (CSS) and PDSS-2 total (rho = -0.065, p = 0.612). Conclusion: Rotigotine improved sleep in patients with a baseline PDSS-2 &gt;= 18 and in DA-na & iuml;ve patients, but not in the whole study group. Additionally, rotigotine seemed to improve motor function and quality of life. PTID improved with treatment. Whether the improved PTID reflects a positive impact on daytime sleepiness or just improved mobility and to what extent PKG nighttime scores accurately represent sleep variables remains to be investigated in further studies.Funding Agencies|Medical Faculty at Lund University, Multipark; Swedish Parkinson Academy; Swedish Parkinson Foundation; Skane University Hospital Foundation and Donations; Global Kinetics Corporation</p
Brain volumes are related with motor skills at late childhood in children born extremely preterm
No full textBackground: This study had three aims. First, we wanted to explore if there was difference in motor performance at 12 years of age in children born extremely preterm (EPT &lt; 28 weeks of gestation) and at term. Our second aim was to study whether the volumes of motor networks and regions differed between those groups when they underwent brain scans at 10 years of age. Third, we investigated whether there were differences in the motor networks and regions of the brain in children born EPT who did or did not have motor impairment at 12 years of age. Methods: In a Swedish national study, a subgroup of 42 children born before 27 weeks and 25 term-born controls underwent MRI at age 10. A neuroradiologist performed MRI acquisitions, and analyses focused on brain regions associated with motor function. At age 12, motor function was assessed using the Movement Assessment Battery for Children - Second Edition (MABC-2), conducted by a licensed physiotherapist. Examiners were blinded to group status. Motor function and motor-related brain volumes were compared between the EPT and control group, and between children born EPT with and without motor impairments. Results: Findings revealed significantly reduced motor performance and smaller motor region volumes in EPT children compared to controls (p &lt; 0.001). Among EPT children, those with motor impairment especially in aiming and catching, had notably smaller brain volume in the basal ganglia (mean difference:1.2 cm3, p = 0.049), cerebellum (mean difference:14.4 cm3, p &lt; 0.001), motor execution (mean difference:3.7 cm3, p = 0.049) network and motor imagery network (mean difference 5.6 cm3, p = 0.049) than their EPT peers without such impairments. Cerebellar volume remained significant different between the groups when adjusting for birth weight and sex in a linear regression model, p = 0.02 (eta 2 = 0.17). Conclusion: The results underscore the impact of extreme prematurity on motor function and brain structure, highlighting a specific link between reduced motor area volumes and impaired ball skills.Funding Agencies|Swedish Medical Research Council; Stockholm County Council; Karolinska Institutet; Swedish Order of Freemasons in Stockholm; Swedish Medical Society; Swedish Brain Foundation; Region Stockholm (clinical research appointment); Saellskapet Barnavard, the Jerring foundation</p
Scientific normative dissonance: A large-scale survey of researchers’ subscription to scientific norms and counternorms across academic fields
No full textWe investigate the extent to which researchers hold morally competing ideals related to scientific norms, which we refer to as scientific normative dissonance. Researchers (n = 11,050) indicated their agreement with four general scientific norms (communality, universalism, disinterestedness, and organized skepticism) and counternorms (individualism, particularism, self-interestedness, and organized dogmatism). Results indicate systematic differences in the relative norm–counternorm subscription (i.e., scientific normative dissonance) across academic fields, academic seniority, and genders. Specifically, normative dissonance was higher among researchers in the medical and health sciences (vs. researchers in social sciences, humanities, or natural sciences), more senior researchers, and male researchers. Our findings have implications for fostering ethical research environments and aligning research practices and incentive structures with scientific ideals.Funding Agencies|Swedish Research Council</p
Roadmap: medical physics technologies in brachytherapy
No full textBrachytherapy is a crucial modality of radiotherapy for cancer, known for its effectiveness in delivering high doses of radiation directly to tumours while sparing surrounding healthy tissues. Despite its clinical importance, recent years have witnessed a concerning decline in its utilization, which negatively impacts patient outcomes. This decline is attributed to several factors, with the inherent complexity of brachytherapy, fair reimbursement policies, and high dexterity being significant barriers. There are silver linings, however, as growing number of applications are seen in continents such as Africa, as well as advances in medical physics technology offering promising solutions to these challenges. This roadmap paper aims to provide a comprehensive overview and preview of advancements in brachytherapy, as well as strategies to address key challenges in four critical areas: 'Imaging and Image Guidance,' 'Treatment Planning,' 'Treatment Delivery,' and 'Brachytherapy Outcomes.' We anticipate that these advances will enhance therapeutic efficacy, equipping clinicians worldwide with the tools needed to deliver state-of-the-art cancer treatments and fostering a promising future in oncology care.Funding Agencies|DoD; National Institute of Health (NIH) [R01-CA233487]</p
No concurrent correlations between parental mental state talk and toddlers language abilities
No full textMental State Talk (MST) is utterances describing invisible mental aspects. The first aim of this study was to investigate the characteristics of Parental MST and Child MST and their concurrent association in a Swedish population, and the second aim was to relate these MST measures to the childrens general language abilities. Seventy-seven dyads of parents and their 25-month-old toddlers participated. MST was assessed by videotaping the dyads during free-play sessions in a laboratory and general language abilities were based on parental reports. Forty-nine toddlers did not produce MST, while all parents used MST. Child MST was positively associated with vocabulary and grammar. Parental MST was not associated with Child MST nor the childrens general language abilities. In exploratory analyses, Parental MST referred to another than the child was positively correlated with vocabulary and grammar. Further studies are needed to confirm these findings and continue studying MST in different linguistic contexts
Innovative Small-molecule Therapies for Psoriasis
No full textPsoriasis is a common, chronic inflammatory skin disease with a strong genetic predisposition. Formerly considered a purely skin disease, it is now recognised as a chronic systemic condition that may affect the nails and joints and can increase the risk of coexisting chronic conditions, such as obesity and cardiovascular disease. The majority of patients experience mild to moderate severity of psoriasis, for which topical treatments are the first-line therapy. For more severe forms, ultraviolet therapy or systemic treatments, such as methotrexate and monoclonal antibodies, are available and can be highly effective. Despite these options, some patients experience insufficient results or adverse effects, and psoriasis is well established to significantly reduce health-related quality of life. In 2014, the World Health Assembly Resolution WHA 67.9 emphasised the need for new, widely accessible treatments for psoriasis. The aim of this doctoral thesis was to evaluate novel small-molecule treatment options for psoriasis within the field of redox medicine. In Study I, we investigated small-molecule MutT Homolog 1 (MTH1) inhibitors in preclinical models. The enzyme MTH1 is crucial for preventing oxidative damage to guanine, a nucleotide and building block of DNA. Cancer cells exhibit increased oxidative DNA damage and over-express MTH1 to protect their survival. Inhibition of MTH1, a strategy to disrupt this protective mechanism, is currently under clinical investigation by Prof. Helleday's group at Karolinska Institutet (KI). Psoriasis shares pathological features with cancer, such as hyperproliferation, a pro-inflammatory environment, and angiogenesis, although malignant transformation generally does not occur in psoriatic cells. Psoriatic tissue also exhibits disrupted redox homeostasis, and we demonstrated in Study I that the enzyme MTH1 is upregulated in human psoriatic skin. MTH1 inhibition with subcutaneous injections reduced histological characteristics and inflammation in an in vivo mouse model of psoriasis. Our results of genetic analyses further support MTH1 inhibitors as a potential future treatment option for psoriasis. In Study II, we investigated the functional role of the gene nitric oxide synthase 2 (NOS2), which has been identified as a susceptibility gene for psoriasis. It has also been suggested as a disease classifier, distinguishing it from different types of eczema, another common skin disease. The small molecule nitric oxide (NO) is produced by NOS2, and other isoforms of NOS. NO has been shown to exhibit pleiotropic effects depending on its concentration in cells, which can lead to opposite effects on various biological functions, such as promoting or inhibiting proliferation and inflammation. We demonstrated that NOS2 contributes significantly to the psoriatic phenotype in a mouse model of psoriasis. Additionally, we observed beneficial effects of an NO-donor cream in the imiquimod (IMQ) mouse model, with decreased keratinocyte proliferation and reduced inflammatory infiltrate in the dermis. The results of Study II highlight the therapeutical potential of an NO-donor cream as a novel topical treatment option for the majority of patients with mild-to-moderate psoriasis. In Study III, we evaluated a topical formulation of an MTH1 inhibitor (MTH1i TH1579) and demonstrated a diminished psoriatic phenotype in an in vivo mouse model of psoriasis. We showed that the number of IL-17-producing T-cells, crucial immune cells involved in driving the inflammation, was significantly reduced in murine skin following short-term treatment. Additionally, we observed a near abolition of IL-17 gene expression, an effect that may play a pivotal role in the pathophysiology of psoriasis. Furthermore, we explored an MTH1-S-phase kinase-associated protein 2 (SKP2)-Enhancer of zeste homolog (EZH2) pathway potentially involved in the antiproliferative effects of topical MTH1 inhibition through its impact on the cell cycle. In conclusion, this thesis provides the foundation for the development of novel treatment options for psoriasis with the small-molecule substances MTH1i TH1579 and NO, the latter incorporated into an NO-donor cream, showing beneficial effects in a well-established mouse model of psoriasis.Psoriasis är en inflammatorisk och kronisk hudsjukdom som drabbar människor i alla åldrar världen över. Vanligtvis uppstår välavgränsade röda plack med silvriga eller grå fjäll på huden. Sjukdomen ansågs tidigare vara en ren hudsjukdom, men betraktas numera som en inflammatorisk systemsjukdom, vilket innebär att inflammationen också påverkar inre delar av kroppen. I detta sammanhang är det betydelsefullt att personer med hög sjukdomsbörda löper en ökad risk för samtidigt förekommande kroniska sjukdomar, såsom obesitas (fetma) och hjärt-kärlsjukdomar. Många patienter med psoriasis upplever också påverkan på naglar och leder. Det är välkänd att psoriasis har en betydande negativ inverkan på hälsorelaterad livskvalitet. Trots stora framsteg under de senaste decennierna i förståelsen av sjukdomens bakomliggande mekanismer och individens geners bidragande roll, finns det fortfarande ingen botande behandling. Ungefär två tredjedelar av patienterna med psoriasis har en mild till måttlig svårighetsgrad av sjukdomen. Mild psoriasis behandlas vanligtvis med mjukgörande medel och glukokortikoider (kortison), antingen ensamt eller i kombination med kolekalciferol (vitamin D3). Vid otillräcklig effekt tillämpas ljusbehandling som tillägg, följt av systemisk behandling med immunmodulerande läkemedel, där metotrexat är förstahandsvalet. Biologiska läkemedel utgör sista steget i behandlingstrappan. Dessa läkemedel är antikroppar i sprutform och anses för närvarande de mest effektiva behandlingsalternativen. Trots deras höga effektivitet finns det patienter med psoriasis som inte svarar på behandlingen eller som drabbas av allvarliga biverkningar. År 2014 betonade Världshälsoförsamlingen i resolution WHA 67.9 behovet av nya, allmänt tillgängliga behandlings-alternativ för psoriasis. I detta sammanhang är utvecklingen av nya terapier särskilt relevant för den majoritet av patienter med mild till måttlig psoriasis. De tre delarbetena i avhandlingen beskriver experimentella studier inom redoxmedicin för att utveckla nya behandlingar mot psoriasis som kan vara lämpliga för topikal behandling i salva- eller krämform på huden. Små-molekylära ämnen undersöktes, bestående av kemiska molekyler som har förmågan att påverka sjukdomsmekanismer i cellerna. Redoxmedicin är ett relativt nytt forskningsområde som fokuserar på kemiska processer som involverar oxidation- och reduktionsreaktioner (överföring av elektroner), ofta i samband med syre i kroppen. I den första studien undersöktes effekten av MTH1-hämmare i cellförsök och i en musmodell för psoriasis. MTH1-hämmarna utvecklades av en forskargrupp vid Karolinska Institutet, ledd av professor Helleday, som är verksam inom cancerforskning. MTH1-enzymet förhindrar att oxidativt skadade byggstenar (nukleotider) infogas i cellens DNA. Cancerceller utsätts för ökad oxidativ stress på grund av sin höga delningstakt. När enzymet hämmas ansamlas oxidativt skadade nukleotider, vilket leder till att cellerna drabbas av oxidativa DNA-skador och dör, en mekanism som här utnyttjas som behandlingsstrategi mot cancer. Psoriasisceller känne-tecknas också av en hög delningstakt och därmed förhöjd oxidativ stress, även om det sker i en godartad process. Detta inspirerade hypotesen att MTH1-hämmare även skulle kunna vara effektiva mot psoriasis. Eftersom positiva effekter av MTH1-hämmaren vid subkutan applikation (injektion) observerades på den psoriatriska inflammationen i musmodellen i studie I, fortsattes arbetet i studie III med att testa en krämformulering av MTH1-hämmaren. Även MTH1-krämen visade tydliga antiinflammatoriska effekter i mushud redan efter några få applikationer. En nyligen beskriven signalväg, som har betydelse för cellcykeln, undersöktes, vilket kan vara en förklaring varför den snabba delningen av hudceller bromsas och bidrar till att MTH1-hämmare verkar fungera som en innovativ behandlingsstrategi mot psoriasis. I studie II undersöktes en liten gasmolekyl, kväveoxid (NO), som bildas i alla däggdjur samt i vissa växter. Forskning under de senaste decennierna har visat att NO har olika funktioner beroende på dess koncentration. Den används bland annat av celler för att överföra signaler, eftersom den lätt diffunderar genom cellmembran. Vid infektioner med bakterier eller virus kan NO i höga koncentrationer användas för att eliminera dessa patogener. NO är en kraftfull vasodilatator, vilket innebär att det får blodkärlen att vidgas, vilket i sin tur leder till att blodtrycket sänks. En brist på NO i blodkärlen är en viktig mekanism bakom högt blodtryck. Genen för enzymet NOS2, som producerar NO i höga koncentrationer, har i studier visat sig vara betydelsefull i samband med psoriasis. I studie II undersöktes därför betydelsen av NOS2 för psoriasis i cell- och djurmodeller. I mus-försök analyserades effekten av ökad NO genom applicering av en NO-frisättande kräm. En förbättring av den psoriatriska inflammationen observerades, vilket indikerar att behandling med en NO-frisättande kräm kan vara en möjlig framtida behandlingsstrategi mot psoriasis. Sammanfattningsvis banar de tre studierna i avhandlingen väg för innovativa behandlingsalternativ för psoriasis inom redoxmedicin, med särskilt fokus på topikala behandlingar som kan nå en större patientgrupp, där nuvarande behandlingsalternativ är begränsade
Orthostatic Hypotension and Cognitive Function in Individuals 85 Years of Age: A Longitudinal Cohort Study in Sweden
No full textBackground: Orthostatic hypotension (OH) is more common in the elderly, and associated with increased mortality. However, its implications in 85-year-olds are not known. Methods: In the prospective observational cohort study Elderly in Linköping Screening Assessment (ELSA 85), 496 individuals in Linköping, Sweden, were followed from age 85 years with cognitive assessments. Blood pressure (BP) was measured supine and after 1, 3, 5, and 10 minutes of standing. Participants with a BP fall of ≥20 mmHg systolic or ≥10 mmHg diastolic after 1 or 3 minutes were classified as classical continuous or classical transient OH depending on whether the BP fall was sustained or not, at subsequent measurements. Those with a BP fall of the same magnitude, but only after 5 or 10 minutes were classified as delayed OH. Results: Of participants, 329 took part in BP measurements and were included. Of these, 156 (47.4%) had classical OH (113 [34.3%] continuous classical, 38 [11.6%] transient classical), and 15 (4.6%) had delayed OH. Cognitive assessments were not markedly different between groups. After 8.6 years, 195 (59.3%) of the participants had died, and delayed vs no OH was associated with twice the risk of all-cause mortality, HR 2.15 (95% CI 1.12-4.12). Transient classical OH was associated with reduced mortality, HR 0.58 (95% CI 0.33-0.99), but not after multiple adjustments, and continuous classical OH was not associated with mortality. Conclusion: OH may have different implications for morbidity and mortality in 85-year-olds compared with younger populations.Funding: Swedish National Research School in General Practice; George Institute for Global Health; National Research School in General Practice; Swedish Society of Medicine, The Strategic Research Network in Circulation and Metabolism at Linkping University; Swedish Society for Medical Research; Health Research Council in the South-East of Sweden [FORSS-8888, FORSS-11636, FORSS-31811, LIO-11877, LIO-31321, LIO-79951]</p
Mental training in school - a key to pupil´s well-being? : A literature review on mental training in school enviroment
No full textI samhällsdebatten beskrivs det ofta att unga idag mår dåligt och att deras psykiska hälsa blir alltsämre. Den här litteraturstudien har undersökt vad forskningen säger om användning av mentalträning i skolmiljö för att minska problemen som benämns - subjektiv ohälsa. Hur används mentalträning i svensk skola idag eller om det har gjorts några försök att applicera dessa tekniker iskolmiljö är några frågor som den här studien vill finna svar på. Studien söker i forskningen ävensvar på om det har gjorts några sådana försök i andra länder eller om det finns program i något landsom används idag och vilka resultat dessa har gett. De delar inom mental träning som har varitintressanta för denna studie är avslappning och positiv psykologi.Resultaten pekar på att elever som genomgår program med avslappningsövningar känner sig mindrestressade, har en högre grad av välbefinnande och är bättre på att fokusera. Likande resultat går attse vid program som genomförs med utgångspunkt i positiv psykologi. Andra positiva effekter avdessa program är en bättre självkänsla, ökat självförtroende att våga prova nya saker och resiliensmot motgångar. Några av programmen visar minskad förekomst av ångest eller depression hosdeltagarna, men inte alla
Prediction-Based Resource Management for Heterogeneous Multi-Core Embedded Systems
No full textIn modern embedded heterogeneous architectures, multiple processing resources are often integrated to achieve performance benefits. Different tasks operate on various segments of these systems, resulting in variations in timing, temperature, and energy consumption. A key component for such a system is a resource manager (RM) capable of taking decisions such that resources are used most efficiently and performance requirements are satisfied. Moreover, modern platforms often encounter fluctuating workloads that are not known at design time. This uncertainty makes traditional design-time resource management methods impractical. In such scenarios, runtime resource management decisions can be enhanced by not only considering the current state (current workload) of the platform but also by incorporating forecasts of future workloads. For example, predicting the upcoming workload allows more tasks to be mapped to the most suitable processors, thereby avoiding unnecessary migration time and energy overhead. Furthermore, leveraging workload prediction improves resource allocation efficiency, enabling more tasks to meet their deadlines in scenarios involving time-sensitive applications.While incorporating workload prediction is an appealing strategy, it raises several questions: (1) Can workload be predicted in realistic scenarios? (2) Is it feasible to implement lowoverhead predictive models? (3) How adaptable are these models if the workload changes unexpectedly? To address these questions, the first part of this thesis focuses on task-level workload prediction. We develop a two-phase machine learning-based framework for modeling and predicting the arrival time of resource requests (workloads). Our experiments reveal that the arrival times of resource requests in real-world scenarios exhibit certain patterns that can be exploited for prediction. Furthermore, we demonstrate that user behavior shows predictable patterns in the sequence of request types (workload types) over time, and these patterns can be leveraged for request type prediction. After predicting the workload, additional questions arise: (1) What would a resource manager that incorporates workload prediction look like? (2) Does workload prediction actually enhance the efficiency of resource management, and if so, to what extent? (3) How accurate does the prediction need to be to improve decisions rather than potentially causing harm? (4) Does knowing more about the future workload (predicting multiple steps ahead) provide a significant increase in efficiency? Finding answers to these questions is the focus of the subsequent part of the thesis. By proposing a prediction-based resource manager that aims at meeting task deadlines while minimizing energy consumption, and by conducting extensive tests, we attempt to provide answers to the aforementioned questions. Our experiments demonstrate that incorporating workload prediction into resource management improves the efficiency of resource manager decisions. Furthermore, the extent of this improvement depends on several factors, including workload intensity, prediction accuracy, and runtime overhead. We analyze the impact of each of these factors individually to gain a clearer understanding of their influence on the overall effectiveness of our methodology. In contemporary multi-core systems, there is also a discernible trend toward reducing the size of processing cores relative to their power consumption. This reduction leads to higher power density within chips, resulting in elevated temperatures. Thus, addressing temperature-related issues is essential in any resource management technique. In the final part of the thesis, we present resource management strategies that aim to achieve the following objectives: (1) Incorporate predictions of future arriving requests up to n steps ahead, (2) Ensure timely task completion to meet deadlines, (3) Prevent violations of threshold temperatures, and (4) Minimize energy consumption. In the experiments, we demonstrate that even with the constraints imposed by temperature management, incorporating workload prediction consistently improves resource management efficiency.Funding agencies: The Swedish Graduate School in Computer Science (CUGS) and the Swedish Foundation for Strategic Research (SSF) under the project Adaptive Software for the Heterogenous Edge-Cloud-Continuum (ASTECC) (project number FUS21-0033)</p