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  • 1.
    Bagge, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Hedman, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Smedsrud, Sabina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Svärdström, Cornelia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Söderberg, Elisabeth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Valdés, Fernando
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Utveckling av metodik för påvisning och typning av Listeria i livsmedelskedjan2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 2.
    Balian, Alien
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hernandez, Frank
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Nucleases as molecular targets for cancer diagnosis2021In: Biomarker Research, E-ISSN 2050-7771, Vol. 9, no 1, article id 86Article, review/survey (Refereed)
    Abstract [en]

    Early cancer diagnosis is a crucial element to improved treatment options and survival. Great research efforts have been made in the search for better performing cancer diagnostic biomarkers. However, the quest continues as novel biomarkers with high accuracy for an early diagnosis remain an unmet clinical need. Nucleases, which are enzymes capable of cleaving nucleic acids, have been long considered as potential cancer biomarkers. The implications of nucleases are key for biological functions, their presence in different cellular counterparts and catalytic activity led the enthusiasm towards investigating the role of nucleases as promising cancer biomarkers. However, the most essential feature of these proteins, which is their enzymatic activity, has not been fully exploited. This review discusses nucleases interrogated as cancer biomarkers, providing a glimpse of their physiological roles. Moreover, it highlights the potential of harnessing the enzymatic activity of cancer-associated nucleases as a novel diagnostic biomarker using nucleic acid probes as substrates.

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  • 3.
    Bengtsson, Katarina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Design of a galvanotaxic track for cells, using polymer electrodes.2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Galvanotaxis is the movement of cells in an applied electric field. The first steps to design a chip for observations of galvanotaxic behavior of cells were done in this work. The chip is a miniaturised system of previous larger galvanotaxis systems and uses materials which are thought to be biocompatible. The system was constructed on microscope slides with a channel in PDMS with adjacent polymer electrodes. The polymer electrodes were made from poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), glycerol and Silquest A-187. The PEDOT:PSS electrodes were connected with either an evaporated metal electrode of titanium and gold or a gold net. Systems with PEDOT:PSS are neutralised when put in excessive amount of PBS (pH=7.4) for 24 hours. The final system had a channel with dimension length=14 mm, width=0.5 mm and height=0.25 mm. PEDOT:PSS worked as an electrode material and the achieved electric field through the channel was between 55 V/m and 160 V/m with an applied voltage of 1 V. The decrease of the electric field within the first hour was between 10 % and 30%.  Further development of this system could give an easy way to observe galvanotaxic behaviour of cells or an instrument that can distinguish between different cell types.

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  • 4.
    Berglund, Joel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    THE PROSPECT OF LIVING FILTERS: Reducing building sector energy demands by improving indoor air quality2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today people spend all the more time indoors. Asthma, allergies and Sick Building Syndrome (SBS) are affecting an increasing number of people. The remedy for all these affections has long been to increase the volume flow of outdoor air in the ventilation but at the same time cities all over the world are struggling with air pollution and smog rising above endangering levels. Living filters present a new solution where part of the indoor air can be purified and recirculated in a building. This project has compiled research on the area to describe the how and why concerning air purification by plants. Independent research conclude that plants can reduce most hazardous chemical agents in the air.

    Climate change, global warming and increasing demands on energy performance induces a race for countries and companies to improve energy efficiency in all sectors. To the building engineering sector living filters presents a unique solution to cut ventilation energy loses. A powerful simulation tool IDA ICE was used to estimate the energy saving capacity when a living filter is applied in the lunch room of an office floor. Another simulation software; Comsol Multiphysics was used to illustrate the aspects of ventilation flow when a living filter cabinet is deployed in a room. The simulation results show that for three living filter cabinets each measuring 0,7x0,8x1,73 cm the buildings energy usage is reduced with more than the living filters use to operate. The single room simulations then show how a living filter can be accommodated with both mixing and displacing ventilation. However, these simulations also illustrate the importance of the living filters placement to achieve maximum ventilation efficiency. 

    The conclusions from this work are that living filters can reduce building sector energy demands and provide significant indoor environmental benefits. The main issue for using living filters is identified to be building regulations putting strict demands on outdoor air flow and that the hygienic function of each living filter must be verified before it may replace outdoor air.

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    The Prospect of Living Filters
  • 5.
    Cecilia, Bill
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Improving anti-drug antibody assay performance in Gyrolab for therapeutic recombinant antibody Infliximab2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Monoclonal antibodies can be used as targeting therapies for several diseases. One major concern when using these therapies is anti-drug antibodies which may hamper the drugs efficiency. Gyrolab is an automated platform which can be used to develop bridging immunoassays where the anti-drug antibodies affinity towards the monoclonal antibody is utilized. Anti-drug antibody immunoassay development on Gyrolab is limited mainly by three factors which may inappropriately affect signal intensity levels. In this project different variants of bridging immunoassays based on drug Fab fragments have been developed for monoclonal antibody Infliximab, with the purpose to illustrate the effects of these three factors.

    Findings indicate that an assay based completely on drug Fab fragments is more sensitive compared to an assay based on intact drug since less affected by unspecific interactions between drug reagents and complex formations. Surprisingly findings also indicate that an assay based completely on drug Fab fragments is affected by human anti-hinge antibodies which decrease assay sensitivity. The most optimal assay variant is based on the combination between intact capture drug and Fab fragment as detection. This variant is insensitive to false positive reactions caused by Rheumatoid factor and human anti-hinge antibodies, less prone to form unspecific interactions between drug reagents and complex formations in the presence of anti-drug antibodies. The optimal assay variant also demonstrates best drug tolerance in combination with acid dissociation.

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    Master thesis Cecilia Bill
  • 6.
    Chen, DeJiu
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Su, Peng
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Ottikkutti, Suranjan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Embedded Control Systems.
    Vartholomeos, Panagiotis
    Tahmasebi, Kaveh Nazem
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Embedded Control Systems.
    Karamousadakis, Michalis
    Analyzing Dynamic Operational Conditions of Limb Prosthetic Sockets with a Mechatronics-Twin Framework2022In: Applied Sciences, E-ISSN 2076-3417, Vol. 12, no 3, p. 986-986Article in journal (Refereed)
    Abstract [en]

    Lower limb prostheses offer a solution to restore the ambulation and self-esteem of amputees. One key component is the prosthetic socket that serves as the interface between prosthetic device and amputee stump and thereby has a wide range of impacts on efficient fitting, appropriate load transmission, operational stability, and control. For the design and optimization of a prosthetic socket, an understanding of the actual intra-socket operational conditions becomes therefore necessary. This is however a difficult task due to the inherent complexity and restricted observability of socket operation. In this study, an innovative mechatronics-twin framework that integrates advanced biomechanical models and simulations with physical prototyping and dynamic operation testing for effective exploration of operational behaviors of prosthetic sockets with amputees is proposed. Within this framework, a specific Stewart manipulator is developed to enable dynamic operation testing, in particular for a well-managed generation of dynamic intra-socket loads and behaviors that are otherwise difficult to observe or realize with the real amputees. A combination of deep learning and Bayesian Inference algorithms is then employed for analyzing the intra-socket load conditions and revealing possible anomalous. 

  • 7.
    Chen, Jingjing
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Heat-transfer Enhancement for Slurries from Biogas Plants− Properties, processes, and thermal systems2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

     Biomethane production from renewable residues with anaerobic digestion gains increasing attention as a crucial alternative to petroleum fuels. It has been vigorously developed, but the large amounts of subsidy from the government indicate that the process efficiency needs to be further improved. For biomethane production, on the one hand, a great amount of heat needs to be used for heating the feeding slurry, sanitation of slurry, and maintaining the temperature in the large-scale reactors. On the other hand, a large amount of thermophilic effluent slurries brings a huge amount of waste heat, which can be recovered. This makes it important to study how to increase production by improving the thermal efficiency of biogas plants with novel heat exchangers. 

    The working fluids in the biogas plants are the non-Newtonian and high-viscous slurries, and the conventional heat exchangers in biogas plants always show much lower performance compared to those in other industries. Normally, the slurries in the biogas plant consist of different substrates, including straw, manure, food waste, municipal sludge, and their mixtures, and various factors such as the amount and type of solids, particle size, shear rate, and temperature impact the rheological properties of the slurries, which makes the complexity in the rheological properties and the difficulty in developing novel heat exchangers.

    The development of heat exchangers calls for the rheological properties of slurries. However, to the best of our knowledge, only the rheology of manure slurry was systematically determined and modeled considering the effect of temperature. The lack of the rheological properties of slurries further hinders the design and development of novel geometries to enhance the heat transfer of the slurries. Correspondingly, the quantitative contribution and potential of the waste-heat recovery from the slurries to production using the enhanced geometry remain unclear. 

        In this thesis work, to design novel geometry with heat-transfer enhancement for different slurries and determine its potential in thermal cycles in the full-scale biogas plants, firstly, the temperature-dependent rheological properties of the slurries, including the corn straw, food waste, and mixed slurries, were tested and modeled. It was found that these slurries possess strong shear-thinning behavior, the temperature has a significant impact on their dynamic viscosity, and the power-law model combined with the Arrhenius equation can describe the rheology well.

        Subsequently, with the reliable models of the rheological properties as the key input,  Computational Fluid Dynamics simulations were conducted to screen different twisted geometries, determine the heat-transfer performance, and reveal the mechanism of the heat-transfer enhancement. Lab- and pilot-scale experiments were also conducted to validate the numerical results. The twisted hexagonal tubes show a positive enhancement factor up to 2.6 compared to normal heat exchangers in a wide range of operating conditions. The continuous and strong near-wall shear effect is the intrinsic reason for achieving a significant heat-transfer enhancement in the twisted hexagonal tubes. Moreover, the generalized engineering equations for predicting the effective shear rate and heat-transfer performance with measurable parameters were established and verified with both numerical and experimental results.

        Finally, the twisted-hexagonal-tube heat exchange was integrated with complete thermal cycles, including waste-heat recovery and external heating processes in the biogas plant, and the potential of increased production and profits were modeled and analyzed combined with the practical operating conditions in a full-scale biogas plant. It was found that for the waste-heat recovery using the twisted hexagonal tubes, the net raw biogas production can increase by up to 17.0 %, and for the external heating process, the increased profit equivalent to 39 % of total production can be achieved owing to energy conservation in external heating using the twisted-hexagonal-tube heat exchangers for a full-scale biogas plant. 

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  • 8.
    Cruz, Javier
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Microsystems Technology.
    Microfluidics for High-Pressure Inertial Focusing: Focusing, Separation and Concentration of Micro and Sub-micron Particles2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The birth of microsystems set the ground for technologies never imagined before, for it is not only the small size what characterizes the miniaturized systems, but unique phenomena arise in the micro scale. This thesis relates to one such unique phenomenon, inertial focusing, a phenomenon that occurs in microfluidic systems if very special conditions are met and that allows for fine manipulation of particles in fluid samples. This ability is key in a bigger picture: the analysis of complex fluids, where rare particles of interest may be present in very few numbers amongst a myriad of others, making the task difficult – if not impossible. A system exploiting inertial focusing allows, for instance, to focus, separate, isolate and concentrate such rare particles of interest, and even to transfer them to another fluid, thereby enabling/facilitating their detection and analysis. Examples of rare particles of interest in complex fluids are circulating tumor cells in blood, that give away the presence of cancer, extracellular vesicles also in blood, that contain biomarkers with physiological and pathological information about the patient, or bacteria in natural water, where the species present and their numbers are to be monitored for safety reasons and/or biological studies. This thesis covers the state of art physical principles behind the phenomenon and extends the understanding both in theory and applications. Specifically, the technology is extended to allow for manipulation of sub-micron particles, a range of interest as it comprises bacteria, viruses and organelles of eukaryotic cells. This was possible by an analysis of the balance of forces in play and by the integration of inertial focusing in high-pressure systems (up to 200 bar). In a second block, a very special line of inertial focusing is introduced and developed; inertial focusing in High Aspect Ratio Curved (HARC) microfluidics. These systems, engineered to rearrange the force field responsible for the particle manipulation, not only achieve excellent performances for focusing and concentration of particles, but also extreme resolution in their separation (mathematically unlimited; demonstrated experimentally for differences in size down to 80 nm). Perhaps more important than the performance, the systems are stable, intuitive and simpler to design, attributes that we hope will make the technology and its outstanding benefits more accessible to the community. With its remarkable performance, it would not come as a surprise if, in the near future, inertial focusing makes a strong impact on how analyses are performed nowadays and opens up for possibilities beyond the current state of the art.

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  • 9.
    Dashwood, Michael R.
    et al.
    Surgical and Interventional Sciences, Royal Free Hospital Campus, University College London Medical School, London, United Kingdom.
    Pinheiro, Bruno Botelho
    Department of Cardiovascular Surgery, Hospital do Coração Anis Rassi, Goiânia, Goiás, Brazil.
    Souza, Domingos S. R.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Cardiothoracic and Vascular Surgery.
    Impact of saphenous vein harvesting on graft diameter: Supporting the no-touch technique2022In: JTCVS techniques, E-ISSN 2666-2507, Vol. 16, p. 105-106Article in journal (Refereed)
  • 10.
    Dev, Apurba
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. Uppsala University, Sweden.
    Horak, J.
    Kaiser, A.
    Yuan, X.
    Perols, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Björk, P.
    Karlström, A. E.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Kleimann, P.
    Linnros, Jan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Electrokinetic effect for molecular recognition: A label-free approach for real-time biosensing2016In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 82, p. 55-63Article in journal (Refereed)
    Abstract [en]

    We present a simple and inexpensive method for label-free detection of biomolecules. The method monitors the changes in streaming current in a fused silica capillary as target biomolecules bind to immobilized receptors on the inner surface of the capillary. To validate the concept, we show detection and time response of different protein-ligand and protein-protein systems: biotin-avidin and biotin-streptavidin, barstar-dibarnase and Z domain-immunoglobulin G (IgG). We show that specific binding of these biomolecules can be reliably monitored using a very simple setup. Using sequential injections of various proteins at a diverse concentration range and as well as diluted human serum we further investigate the capacity of the proposed technique to perform specific target detection from a complex sample. We also investigate the time for the signal to reach equilibrium and its dependence on analyte concentration and demonstrate that the current setup can be used to detect biomolecules at a concentration as low as 100 pM without requiring any advanced device fabrication procedures. Finally, an analytical model based on diffusion theory has been presented to explain the dependence of the saturation time on the analyte concentration and capillary dimensions and how reducing length and inner diameter of the capillary is predicted to give faster detection and in practice also lower limit of detection.

  • 11.
    Griffith, May
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Lee, Chyan-Jang
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Buznyk, Oleksiy
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Filatov Inst Eye Dis and Tissue Therapy, Ukraine.
    Artificial Corneas, and Reinforced Composite Implants for High Risk Donor Cornea Transplantation2017In: The Stem Cell Microenvironment and its Role in Regenerative Medicine and Cancer Pathogenesis, RIVER PUBLISHERS , 2017, Vol. 7, p. 93-102Conference paper (Refereed)
    Abstract [en]

    Here, we review examples of artificial corneas that have been developed as alternatives to donor cornea transplantation. These consist of artificial corneas developed as prostheses and regenerative scaffolds. Examples of reinforced and composite implants developed within our group are profiled.

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  • 12.
    Iredahl, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Assessment of microvascular and metabolic responses in the skin2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The general aim of this project was to develop experimental in vivo models that allow for minimally invasive investigations of responses in the skin to microvascular and metabolic provocations. The cutaneous microvasculature has emerged as a valuable model and been proposed to mirror the microcirculation in other organs. Dysfunction in the cutaneous microcirculation has thus been linked to systemic diseases such as hypertension and diabetes mellitus. Models for investigating skin responses could facilitate the understanding of pathophysiological mechanisms as well as effects of drugs.

    In the first study, three optical measurement techniques (laser Doppler flowmetry (LDF), laser speckle contrast imaging (LSCI) and tissue viability imaging (TiVi)) were compared against each other and showed differences in their ability to detect microvascular responses to provocations in the skin. TiVi was found more sensitive for measurement of noradrenaline-induced vasoconstriction, while LSCI was more sensitive for measurement of vascular occlusion. In the second study, microvascular responses in the skin to iontophoresis of vasoactive drugs were found to depend on the drug delivery protocol. Perfusion half-life was defined and used to describe the decay in the microvascular response to a drug after iontophoresis. In the third study, the role of nitric oxide (NO) was assessed during iontophoresis of insulin. The results showed a NO-dependent vasodilation in the skin by insulin. In the fourth study the vasoactive and metabolic effects of insulin were studied after both local and endogenous administration. Local delivery of insulin increased skin blood flow, paralleled by increased skin concentrations of interstitial pyruvate and lactate, although no change in glucose concentration was observed. An oral glucose load resulted in an increased insulin concentration in the skin paralleled by an increase in blood flow, as measured using the microdialysis urea clearance technique, although no changes in perfusion was measured by LSCI.

    The thesis concludes that when studying skin microvascular responses, the choice of measurement technique and the drug delivery protocol has an impact on the measurement results, and should therefore be carefully considered. The thesis also concludes that insulin has metabolic and vasodilatory effects in the skin both when administered locally and as an endogenous response to an oral glucose load. The vasodilatory effect of insulin in the skin is mediated by nitric oxide.

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    Assessment of microvascular and metabolic responses in the skin
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  • 13.
    Johansson, Johannes D.
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation.
    Fredriksson, Ingemar
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Wårdell, Karin
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Eriksson, Ola
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Simulation of reflected light intensity changes during navigation and radio frequency lesioning in the brain2009In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 14, no 044040Article in journal (Refereed)
    Abstract [en]

    An electrode with adjacent optical fibers for measurements during navigation and radio frequency lesioning in the brain was modeled for Monte Carlo simulations of light transport in brain tissue. Relative reflected light intensity at 780 nm, I780, from this electrode and probes with identical fiber configuration were simulated using the intensity from native white matter as reference. Models were made of homogeneousnative and coagulated gray, thalamus, and white matter as well as blood. Dual layermodels, including models with a layer of cerebrospinal fluid between the fibers andthe brain tissue, were also made. Simulated I780 was 0.16 for gray matter, 0.67 forcoagulate gray matter, 0.36 for thalamus, 0.39 for coagulated thalamus, unity forwhite matter, 0.70 for coagulated white matter and 0.24 for blood. Thalamic matterhas also been found to reflect more light than gray matter and less than white matterin clinical studies. In conclusion the reflected light intensity can be used todifferentiate between gray and white matter during navigation. Furthermore,coagulation of light gray tissue, such as the thalamus, might be difficult to detectusing I780, but coagulation in darker gray tissue should result in a rapid increase of I780.

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  • 14.
    Jonasson, Hanna
    et al.
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Fredriksson, Ingemar
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. Perimed AB, Sweden.
    Bergstrand, Sara
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Nursing Sciences and Reproductive Health. Linköping University, Faculty of Medicine and Health Sciences.
    Östgren, Carl Johan
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Prevention, Rehabilitation and Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Primary Care Center, Primary Health Care Center Ekholmen.
    Larsson, Marcus
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Strömberg, Tomas
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Absorption and reduced scattering coefficients in epidermis and dermis from a Swedish cohort study2023In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 28, no 11Article in journal (Refereed)
    Abstract [en]

    Significance Knowledge of optical properties is important to accurately model light propagation in tissue, but in vivo reference data are sparse.Aim The aim of our study was to present in vivo skin optical properties from a large Swedish cohort including 3809 subjects using a three-layered skin model and spatially resolved diffuse reflectance spectroscopy (Periflux PF6000 EPOS).Approach Diffuse reflectance spectra (475 to 850 nm) at 0.4 and 1.2 mm source-detector separations were analyzed using an inverse Monte Carlo method. The model had one epidermis layer with variable thicknesses and melanin-related absorptions and two dermis layers with varying hemoglobin concentrations and equal oxygen saturations. The reduced scattering coefficient was equal across all layers.Results Median absorption coefficients (mm (- 1)) in the upper dermis ranged from 0.094 at 475 nm to 0.0048 at 850 nm and similarly in the lower dermis from 0.059 to 0.0035. The reduced scattering coefficient (mm( - 1)) ranged from 3.22 to 1.20, and the sampling depth (mm) ranged from 0.23 to 0.38 (0.4 mm separation) and from 0.49 to 0.68 (1.2 mm separation). There were differences in optical properties across sex, age groups, and BMI categories.Conclusions Reference material for skin optical properties is presented.

  • 15.
    Nordesjö, Olle
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Pontén, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Herman, Stephanie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Ås, Joel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Jamal, Sabri
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Nyberg, Alona
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Ett sannolikhetsbaserat kvalitetsmått förbättrar klassificeringen av oförväntade sekvenser i in situ sekvensering2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In situ sequencing is a method that can be used to localize differential expression of mRNA directly in tissue sections, something that can give valuable insights to many statest of disease. Today, many of the registered sequences from in situ sequencing are lost due to a conservative quality measure used to filter out incorrect sequencing reads. There is room for improvement in the performance of the current method for base calling since the technology is in an early stage of development. We have performed exploratory data analysis to investigate occurrence of systematic errors, and corrected for these by using various statistical methods. The primary methods that have been investigated are the following:

    I) Correction of emission spectra overlap resulting in spillover between channels.

    II) A probability-based interpretation of intensity data, resulting in a novel quality measure and an alternative classifier based on supervised learning.

    III) Analysis of occurrence of cycle dependent effects, e.g. incomplete dehybridization of fluorescent probes.

    We suggest the following:

    • Implementation and evaluation of the probability-based quality measure
    • Development and implementation of the proposed classifier
    • Additional experiments to investigate the possible occurrence of incomplete dehybridization
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  • 16.
    Ramírez-Chavarría, Roberto G.
    et al.
    Universidad Nacional Autónoma de México.
    Müller, Matias I.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Mattila, Robert
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Quintana-Carapia, Gustavo
    Vrije Universiteit Brussel.
    Sánchez-Pérez, Celia
    Universidad Nacional Autónoma de México.
    A framework for high-resolution frequency response measurement and parameter estimation in microscale impedance applications2019In: Measurement, ISSN 0263-2241, Vol. 148, article id 106913Article in journal (Refereed)
    Abstract [en]

    Electrical impedance spectroscopy (EIS) is a tool for characterizing the electrical behavior of matter. Nevertheless, most of the work is focused on purely experimental results, leading aside alternative measurement and estimation techniques. In this paper, we introduce a framework for spectral measurements and parameter estimation applied to EIS. There are two methods in the proposal running independently: frequency response function based non-parametric estimation, and parametric recursive estimation. The former provides consistent estimates even in the presence of noise and works with batches of data. Whilst the latter gives consistent parametric estimates under the right model structure. The proposed platform is designed around a reconfigurable device, which comprises minimal hardware design and digital signal processing. We test the system with a multisine signal by measuring calibration circuits and colloidal samples at microscale. Results show that this method outperforms the state-of-the-art techniques for impedance measurement applications, exhibiting low uncertainty and physical interpretation.

  • 17.
    Ramírez-Chavarría, Roberto G.
    et al.
    Universidad Nacional Autónoma de México.
    Quintana-Carapia, Gustavo
    Vrije Universiteit Brussel.
    Müller, Matias I.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Mattila, Robert
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Matatagui, Daniel
    Universidad Nacional Autónoma de México.
    Sánchez-Pérez, Celia
    Universidad Nacional Autónoma de México.
    Bioimpedance Parameter Estimation using Fast Spectral Measurements and Regularizaton2018In: IFAC-PapersOnLine, IFAC Papers Online, 2018, Vol. 51, no 15, p. 521-526Conference paper (Refereed)
    Abstract [en]

    This work proposes an alternative framework for parametric bioimpedance estimation as a powerful tool to characterize biological media. We model the bioimpedance as an electrical network of parallel RC circuits, and transform the frequency-domain estimation problem into a time constant domain estimation problem by means of the distribution of relaxation times (DRT) method. The Fredholm integral equation of the first kind is employed to pose the problem in a regularized least squares (RLS) form. We validate the proposed methodology by numerical simulations for a synthetic biological electrical circuit, by using a multisine signal in the frequency range of 1kHz to 853kHz and considering an error in variables (EIV) problem. Results show that the proposed method outperforms the state-of-the-art techniques for spectral bioimpedance analysis. We also illustrates its potentiality in terms of accurate spectral measurements and precise data interpretation, for further usage in biological applications.

  • 18.
    Rogozea, Dan
    Jönköping University, School of Engineering.
    Design, 3D Bioprinting, and Testing of Otic Prosthesis2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The middle ear is a complex organ with multiple functions. It is prone to accidental, genetic, excessive noise exposure, or age-related damage. Its main role is to convey and amplify the mechanical vibrations of the tympanic membrane to the acoustic nerve through three connected small bones, the ossicles; malleus, incus, and stapes. When severely damaged, the most used solution is currently a partial or total ossicle replacement with inorganic titanium prostheses, which are not anatomically similar. However, 3D models derived from micro-CT scans of human ossicular chains are freely available for research and educational purposes in high resolution 3D files. Therefore, these files were scaled to anatomical size and used to print partial models of the malleus and incus using an extrusion contact method using a bioprinter and OsteoInk, a calcium phosphate-based paste sold by the bioprinting company regenHU. The use of this biologically analogous material to 3D print anatomically sized and shaped ossicles is novel. The process and settings for bioprinting the malleus and incus were devised and tested for repeatability. OsteoInk was found suitable to form hard bone-like objects after printing and curing. However, for this process to be successful with OsteoInk, the models required a flat base; the first .560 mm of the virtual model were not printed. A support structure is required for creating complete ossicles, but the hydrogel and polymer structures attempted were not deemed feasible. The support structure could be created by combining the OsteoInk with other biomaterials, or by fibers printed through Melt Electrospinning Writing. The workflow devised in this project is applicable to other bioprinters, and to thus to further the research in the field of bioprinting.

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  • 19.
    Silverå Ejneby, Malin
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jakesova, Marie
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Brno Univ Technol, Czech Republic.
    Ferrero, Jose J.
    Columbia Univ, NY 10027 USA.
    Migliaccio, Ludovico
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Brno Univ Technol, Czech Republic.
    Sahalianov, Ihor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhao, Zifang
    Columbia Univ, NY 10027 USA.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Khodagholy, Dion
    Columbia Univ, NY 10027 USA.
    Derek, Vedran
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Zagreb, Croatia.
    Gelinas, Jennifer N.
    Columbia Univ, NY 10027 USA; Columbia Univ, NY 10027 USA.
    Glowacki, Eric
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Brno Univ Technol, Czech Republic.
    Chronic electrical stimulation of peripheral nerves via deep-red light transduced by an implanted organic photocapacitor2022In: Nature Biomedical Engineering, E-ISSN 2157-846X, Vol. 6, no 6, p. 741-753Article in journal (Refereed)
    Abstract [en]

    Implantable devices for the wireless modulation of neural tissue need to be designed for reliability, safety and reduced invasiveness. Here we report chronic electrical stimulation of the sciatic nerve in rats by an implanted organic electrolytic photocapacitor that transduces deep-red light into electrical signals. The photocapacitor relies on commercially available semiconducting non-toxic pigments and is integrated in a conformable 0.1-mm(3) thin-film cuff. In freely moving rats, fixation of the cuff around the sciatic nerve, 10 mm below the surface of the skin, allowed stimulation (via 50-1,000-mu s pulses of deep-red light at wavelengths of 638 nm or 660 nm) of the nerve for over 100 days. The robustness, biocompatibility, low volume and high-performance characteristics of organic electrolytic photocapacitors may facilitate the wireless chronic stimulation of peripheral nerves. An organic electrolytic photocapacitor transducing deep-red light into electrical signals and implanted within a thin cuff around the sciatic nerve of rats allows for wireless electrical stimulation of the nerve for over 100 days.

  • 20.
    Singh, Shikha
    et al.
    Luleå University of Technology, Sweden; Universitat Politècnica de Catalunya Barcelona Tech, Spain.
    Patel, Mitul
    Luleå University of Technology, Sweden.
    Geng, Shiyu
    Luleå University of Technology, Sweden.
    Teleman, Anita
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Herrera, Natalia
    Luleå University of Technology, Sweden.
    Schwendemann, Daniel
    Luleå University of Technology, Sweden; OST Eastern Switzerland University of Applied Sciences, Switzerland.
    Maspoch, Maria
    Universitat Politècnica de Catalunya Barcelona Tech, Spain.
    Oksman, Kristina
    Luleå University of Technology, Sweden;University of Toronto, Canada.
    Orientation of polylactic acid–chitin nanocomposite films via combined calendering and uniaxial drawing: Effect on structure, mechanical, and thermal properties2021In: Nanomaterials, E-ISSN 2079-4991, Vol. 11, no 12, article id 3308Article in journal (Refereed)
    Abstract [en]

    The orientation of polymer composites is one way to increase the mechanical properties of the material in a desired direction. In this study, the aim was to orient chitin nanocrystal (ChNC)-reinforced poly(lactic acid) (PLA) nanocomposites by combining two techniques: calendering and solid-state drawing. The effect of orientation on thermal properties, crystallinity, degree of orientation, mechanical properties and microstructure was studied. The orientation affected the thermal and structural behavior of the nanocomposites. The degree of crystallinity increased from 8% for the isotropic compression-molded films to 53% for the nanocomposites drawn with the highest draw ratio. The wide-angle X-ray scattering results confirmed an orientation factor of 0.9 for the solid-state drawn nanocomposites. The mechanical properties of the oriented nanocomposite films were significantly improved by the orientation, and the pre-orientation achieved by film calendering showed very positive effects on solid-state drawn nanocomposites: The highest mechanical properties were achieved for pre-oriented nanocomposites. The stiffness increased from 2.3 to 4 GPa, the strength from 37 to 170 MPa, the elongation at break from 3 to 75%, and the work of fracture from 1 to 96 MJ/m3. This study demonstrates that the pre-orientation has positive effect on the orientation of the nanocomposites structure and that it is an extremely efficient means to produce films with high strength and toughness. © 2021 by the authors. 

  • 21.
    Thorsén, Jenny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Purification of His-tagged Proteins Using WorkBeads 40 TREN as a Pre-Treatment Step Prior Loading Sample onto IMAC Resins with the Purpose to Enhance Performance2021Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work is the result of evaluating a novel strategy for the purification of recombinant His-tagged proteins. Proteins purified in this study were the E. coli translational proteins IF-3, RF-1, and RFF. The study aimed to analyse the potential of using Bio-Works WorkBeads™40 TREN, a multimodal anion ion exchange chromatography resin, as a pretreatment step upstream an immobilized metal ion chromatography (IMAC) resin to enhance performance efficiency of His-tagged protein purification. The method demonstrated here shows potential for anyone seeking to increase the purity of His-tagged protein purification or to introduce an effective purification procedure by replacing a polishing step downstream IMAC with WorkBeads 40 TREN upstream IMAC. The latter contributing to guard the IMAC column from heavy bioburden. This study showed that running WorkBeads 40 TREN prior IMAC captures impurities and removes 97-98 % more dsDNA compared to direct IMAC. WorkBeads 40 TREN is therefore highly advantageous to include early in a purification process to remove protein binding DNA fragments. Moreover, WorkBeads 40 TREN increases purity in the final product by capturing more host cell proteins than when running direct IMAC. This concept is general and WorkBeads 40 TREN could be used upstream a variety of resins such as Protein A and RPC.

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  • 22.
    Ulmefors, Hanna
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Yang Nilsson, Ting
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Eriksson, Viktor
    Chalmers University of Technology, Sweden.
    Eriksson, Gustav
    Chalmers University of Technology, Sweden.
    Evenäs, Lars
    Chalmers University of Technology, Sweden.
    Andersson Trojer, Markus
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites. Chalmers University of Technology, Sweden.
    Solution-Spinning of a Collection of Micro- and Nanocarrier-Functionalized Polysaccharide Fibers2022In: Macromolecular materials and engineering, ISSN 1438-7492, E-ISSN 1439-2054, Vol. 307, no 8, article id 2200110Article in journal (Refereed)
    Abstract [en]

    Continuous polysaccharide fibers and nonwovens—based on cellulose, hydroxypropyl cellulose, chitosan, or alginate—containing biopolymeric microcapsules (MC) or mesoporous silica nanoparticles (MSN) are prepared using a wet-spinning or solution blowing technique. The MCs are homogeneously distributed in the fiber matrices whereas the MSNs form discrete micron-sized aggregates as demonstrated using scanning electron-, fluorescence-, and confocal microscopy. By encapsulating the model compound pyrene, it is shown that 95% of the substance remains in the fiber during the formation process as compared to only 7% for the nonencapsulated substance. The material comprising the MC has a strong impact on the release behavior of the encapsulated pyrene as investigated using methanol extraction. MCs based on poly(l-lactic acid) prove to be practically impermeable with no pyrene released in contrast to MCs based on poly(lactic-co-glycolic acid) which allow for diffusion of pyrene through the MC and fiber as visualized using fluorescence microscopy. © 2022 The Authors.

  • 23.
    Valenti, Marco
    et al.
    Delft University of Technology, Netherlands.
    Kontoleta, Evgenia
    Delft University of Technology, Netherlands.
    Digdaya, Ibadillah A.
    Delft University of Technology, Netherlands.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Biskos, George
    Delft University of Technology, Netherlands; Cyprus Institute, Cyprus.
    Schmidt-Ott, Andreas
    Delft University of Technology, Netherlands.
    Smith, Wilson A.
    Delft University of Technology, Netherlands.
    The Role of Size and Dimerization of Decorating Plasmonic Silver Nanoparticles on the Photoelectrochemical Solar Water Splitting Performance of BiVO4 Photoanodes2016In: ChemNanoMat, E-ISSN 2199-692X, Vol. 2, no 7, p. 739-747Article in journal (Refereed)
    Abstract [en]

    Ag nanoparticles (NPs) are deposited on BiVO4 photoanodes to study their effect on the photoelectrochemical (PEC) water splitting performance of the semiconductor. 15 nm light-absorbing NPs and 65 nm light scattering NPs were studied separately to compare their light trapping ability for enhancing the semiconductors absorption through light concentration and light scattering, respectively. The 15 nm NPs enhanced the BiVO4 external quantum efficiency throughout the semiconductors absorption range (e.g.,approximate to 2.5 fold at lambda=400 nm). However, when a hole scavenger was added to the electrolyte, no enhancement was ob-served upon NP deposition, indicating that the NPs only facilitate the injection of holes from the semiconductor surface to the electrolyte but do not enhance its absorption. On the other hand, the 65 nm scattering NPs not only facilitated hole injection to the electrolyte, but also enhanced the absorption of the semiconductor (by approximate to 6%) through light scattering. Such a dual effect, i.e., of enhancing both the surface properties and the absorption of the semiconductor, makes light scattering Ag NPs an ideal decoration for PEC water splitting photoelectrodes.

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