| 1. |
- Enroth, Stefan, et al.
(författare)
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Effects of Long-Term Storage Time and Original Sampling Month on Biobank Plasma Protein Concentrations
- 2016
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 12, s. 309-314
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Tidskriftsartikel (refereegranskat)abstract
- The quality of clinical biobank samples is crucial to their value for life sciences research. A number of factors related to the collection and storage of samples may affect the biomolecular composition. We have studied the effect of long-time freezer storage, chronological age at sampling, season and month of the year and on the abundance levels of 108 proteins in 380 plasma samples collected from 106 Swedish women. Storage time affected 18 proteins and explained 4.8–34.9% of the observed variance. Chronological age at sample collection after adjustment for storage-time affected 70 proteins and explained 1.1–33.5% of the variance. Seasonal variation had an effect on 15 proteins and month (number of sun hours) affected 36 proteins and explained up to 4.5% of the variance after adjustment for storage-time and age. The results show that freezer storage time and collection date (month and season) exerted similar effect sizes as age on the protein abundance levels. This implies that information on the sample handling history, in particular storage time, should be regarded as equally prominent covariates as age or gender and need to be included in epidemiological studies involving protein levels.
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| 2. |
- Al-Behadili, Ali, et al.
(författare)
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A two-nuclease pathway involving RNase H1 is required for primer removal at human mitochondrial OriL
- 2018
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Ingår i: Nucleic acids research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 46:18, s. 9471-9483
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Tidskriftsartikel (refereegranskat)abstract
- The role of Ribonuclease H1 (RNase H1) during primer removal and ligation at the mitochondrial origin of light-strand DNA synthesis (OriL) is a key, yet poorly understood, step in mitochondrial DNA maintenance. Here, we reconstitute the replication cycle of L-strand synthesis in vitro using recombinant mitochondrial proteins and model OriL substrates. The process begins with initiation of DNA replication at OriL and ends with primer removal and ligation. We find that RNase H1 partially removes the primer, leaving behind the last one to three ribonucleotides. These 5'-end ribonucleotides disturb ligation, a conclusion which is supported by analysis of RNase H1-deficient patient cells. A second nuclease is therefore required to remove the last ribonucleotides and we demonstrate that Flap endonuclease 1 (FEN1) can execute this function in vitro. Removal of RNA primers at OriL thus depends on a two-nuclease model, which in addition to RNase H1 requires FEN1 or a FEN1-like activity. These findings define the role of RNase H1 at OriL and help to explain the pathogenic consequences of disease causing mutations in RNase H1.
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| 3. |
- Alrifaiy, Ahmed, et al.
(författare)
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A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy : first investigations of single biological cells
- 2015
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Ingår i: Biomedical engineering online. - : Springer Science and Business Media LLC. - 1475-925X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.
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| 4. |
- Cheddad, Abbas, et al.
(författare)
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Improving signal detection in emission optical projection tomography via single source multi-exposure image fusion
- 2013
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 21:14, s. 16584-16604
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a technique to improve structural data obtained from Optical Projection Tomography (OPT) using Image Fusion (IF) and contrast normalization. This enables the visualization of molecular expression patterns in biological specimens with highly variable contrast values. In the approach, termed IF-OPT, different exposures are fused by assigning weighted contrasts to each. When applied to projection images from mouse organs and digital phantoms our results demonstrate the capability of IF-OPT to reveal high and low signal intensity details in challenging specimens. We further provide measurements to highlight the benefits of the new algorithm in comparison to other similar methods.
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| 5. |
- Chen, Ye, et al.
(författare)
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A global learning with local preservation method for microarray data imputation
- 2016
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Ingår i: Computers in Biology and Medicine. - : Elsevier. - 0010-4825 .- 1879-0534. ; 77, s. 76-89
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Tidskriftsartikel (refereegranskat)abstract
- Microarray data suffer from missing values for various reasons, including insufficient resolution, image noise, and experimental errors. Because missing values can hinder downstream analysis steps that require complete data as input, it is crucial to be able to estimate the missing values. In this study, we propose a Global Learning with Local Preservation method (GL2P) for imputation of missing values in microarray data. GL2P consists of two components: a local similarity measurement module and a global weighted imputation module. The former uses a local structure preservation scheme to exploit as much information as possible from the observable data, and the latter is responsible for estimating the missing values of a target gene by considering all of its neighbors rather than a subset of them. Furthermore, GL2P imputes the missing values in ascending order according to the rate of missing data for each target gene to fully utilize previously estimated values. To validate the proposed method, we conducted extensive experiments on six benchmarked microarray datasets. We compared GL2P with eight state-of-the-art imputation methods in terms of four performance metrics. The experimental results indicate that GL2P outperforms its competitors in terms of imputation accuracy and better preserves the structure of differentially expressed genes. In addition, GL2P is less sensitive to the number of neighbors than other local learning-based imputation. methods.
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| 6. |
- Du, Ning, et al.
(författare)
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A brief review of the development of telerehabilitation and its application in patients of adolescent idiopathic scoliosis
- 2023
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Ingår i: Journal of Scientific & Technical Research. - 2574-1241. ; 48:2
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Forskningsöversikt (refereegranskat)abstract
- Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity and characterized by progressive development during growth, and eventually to a curvature of the spine greater than 10 degrees on the posteroanterior radiograph. AIS usually does not present symptoms in early age, which makes the diagnosis and treatment of these patients difficult. Thus, a follow-up observation of all suspicious AIS patients becomes very important to monitor the progression of spinal cord deformity. Telerehabilitation is a new type of rehabilitation, which links the professional physiotherapists and the patients through telecommunication and information technology. Telerehabilitation can be synchronous (through any device real-time connection between patients and therapists), asynchronous (computer-based intervention for remote monitoring by the physiotherapists and offline adjustments), or a combination of both. The COVID-19 pandemic has caused medical health care system chaos and affected seriously the ongoing disease management in many countries. Telerehabilitation can reduce the spreading risk of COVID-19, the cost of face-to-face rehabilitation service, the pressure on the staff, and the financial burden on the patients. In this review, we briefly describe the development of telerehabilitation, its current status and related technologies, and its application in clinical practice of AIS. In addition, we discussed the limitations of the current telerehabilitation and its future prospection. We believe that telerehabilitation could provide high quality rehabilitation service to the patients, thus becoming the mainstream of rehabilitation to the population of AIS.
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| 7. |
- Hadrevi, Jenny, et al.
(författare)
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Myosin light chain and calcium regulating protein differences in chronic musculoskeletal neck and shoulder pain
- 2016
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Ingår i: Journal of Integrated Omnics. - : Proteomass Scientific Society. - 2182-0287. ; 6:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Proteomic screening analysis has detected myosin light chain (MLC) as a protein implied to be involved in chronic musculoskeletal neck and shoulder pain. Several analyses of MLC proteins have stated a difference in phosphorylation being the determining factor for protein activation hence altered contrability of the muscle in i.e. senescence. In continuation of a previous publication, this study is an attempt to analyze the different MLC isoforms by mass spectrometry and immune-analyses in myalgic and healthy trapezius muscle. In the present study no differences in phosphorylation level between the corresponding individual proteins were detected using LC-MSMS and immunoblotting; instead we assigned different isoforms of regulatory MLCs. To further elucidate the contrability: calcium (Ca2+) regulatory proteins, sarco(endo)plasmic reticulum Ca2+ ATPase 1 (SERCA-1) and calsequestrine (CSQ) were analyzed by western blot. The analysis revealed a significantly increased abundance of SERCA-1 protein in the myalgic muscle and a significantly increased abundance of CSQ in healthy muscle. Myalgic muscle contraction patterns have in previous studies shown to differ from healthy muscle which may be connected to the Ca2+ availability in the muscle. Here we present the proteomic characterization of differences in Ca2+ regulating proteins and particularly regulatory MLCs in trapezius muscle of women with chronic musculoskeletal neck and shoulder pain.
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| 8. |
- Hellström, Fredrik, et al.
(författare)
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Association between plasma concentrations of linoleic acid-derived oxylipins and the perceived pain scores in an exploratory study in women with chronic neck pain
- 2016
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic musculoskeletal pain may be associated with changes in the balance of algogenic and anti-nociceptive compounds, and such changes may be visible in plasma samples. We have undertaken an exploratory study to measure the levels of endocannabinoids, related N-acylethanolamines and oxylipins (primarily those derived from linoleic acid) in plasma samples from women with chronic neck pain (NP) and chronic widespread pain (CWP), and to investigate whether the observed levels are associated with the pain experienced by these women.Methods: Blood samples from 35 women with NP, 15 with CWP and 27 age-matched controls were analysed for the lipids using ultra performance liquid chromatography coupled to tandem mass spectrometry. Current pain (“NRSday”) and the average pain during the last week (“NRSweek”) were rated by the participants using a numerical rating scale.Results: There were no significant differences in the plasma concentrations of the fifteen lipids investigated between the women with pain and the controls. However, significant correlations were seen for the NP group between the NRSday scores and the plasma concentrations of the linoleic acid derivatives 9- and 13-hydroxy-octadecadienoic acid (Spearman’s rho values 0.51 [P = 0.0016]) and 0.53 [P = 0.0011], respectively).Conclusions: The data obtained in this exploratory study indicate that although no group differences are seen in plasma lipid concentrations, there is an association between the NRSday scores and the 9- and 13-hydroxy-octadecadienoic acid levels. Whether or not the association reflects a causality (i.e. that the circulating lipids contribute to the perceived pain of the pain participants), requires further investigation.
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| 9. |
- Kumar, Abhinav, et al.
(författare)
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Enrichment of immunoregulatory proteins in the biomolecular corona of nanoparticles within human respiratory tract lining fluid
- 2016
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Ingår i: Nanomedicine. - : Elsevier BV. - 1549-9634 .- 1549-9642. ; 12:4, s. 1033-1043
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Tidskriftsartikel (refereegranskat)abstract
- When inhaled nanoparticles deposit in the lungs, they transit through respiratory tract lining fluid (RTLF) acquiring a biomolecular corona reflecting the interaction of the RTLF with the nanomaterial surface. Label-free snapshot proteomics was used to generate semiquantitative profiles of corona proteins formed around silica (SiO2) and poly(vinyl) acetate (PVAc) nanoparticles in RTLF, the latter employed as an archetype drug delivery vehicle. The evolved PVAc corona was significantly enriched compared to that observed on SiO2 nanoparticles (698 vs. 429 proteins identified); however both coronas contained a substantial contribution from innate immunity proteins, including surfactant protein A, napsin A and complement (C1q and C3) proteins. Functional protein classification supports the hypothesis that corona formation in RTLF constitutes opsonisation, preparing particles for phagocytosis and clearance from the lungs. These data highlight how an understanding of the evolved corona is necessary for the design of inhaled nanomedicines with acceptable safety and tailored clearance profiles. From the Clinical Editor: Inhaled nanoparticles often acquire a layer of protein corona while they go through the respiratory tract. Here, the authors investigated the identity of these proteins. The proper identification would improve the understanding of the use of inhaled nanoparticles in future therapeutics. (C) 2016 Published by Elsevier Inc.
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| 10. |
- Larsen, Christian, et al.
(författare)
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Design, fabrication and application of organic power converters : Driving light-emitting electrochemical cells from the AC mains
- 2017
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Ingår i: Organic electronics. - : Elsevier BV. - 1566-1199 .- 1878-5530. ; 45, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- The design, fabrication and operation of a range of functional power converter circuits, based on diode configured organic field-effect transistors as the rectifying unit and capable of transforming a high AC input voltage to a selectable DC voltage, are presented. The converter functionality is demonstrated by selecting and tuning its constituents so that it can effectively drive a low-voltage organic electronic device, a light-emitting electrochemical cell (LEC), when connected to high-voltage AC mains. It is established that the preferred converter circuit for this task comprises an organic full-wave rectifier and a regulation resistor but is void of a smoothing capacitor, and that such a circuit connected to the AC mains (230 V, 50 Hz) successfully can drive an LEC to bright luminance (360 cd m(-2)) and high efficiency (6.4 cd A(-1)).
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