| 1. |
- Mormino, Maurizio, 1988
(författare)
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Exploring Saccharomyces cerevisiae’s responses to acetic acid and other inhibitors found in lignocellulosic hydrolysates
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The limited tolerance of the budding yeast Saccharomyces cerevisiae to lignocellulosic hydrolysate inhibitors is a key challenge to its use in biorefinery cell factories. Considerable resources have been invested in the isolation of yeast strains with better tolerance towards the inhibitors released during lignocellulose hydrolysis, such as acetic acid. The goal of this thesis was twofold: characterize the transcriptional response of S. cerevisiae to wheat straw hydrolysate and explore the role of essential S. cerevisiae genes in acetic and formic acid tolerance, using a new biosensor and competitive growth assays. The transcriptomes of one laboratory strain, two industrial strains, and two wild-type isolates grown in wheat straw hydrolysate were profiled. Despite similar growth, the isolates showed different expression of genes encoding proteins involved in oxidative stress response, lipid accumulation, and transport, suggesting different genetic strategies for tolerance. The new acetic acid biosensor was based on two transcription factors, Haa1 from S. cerevisiae and BM3R1 from Bacillus megaterium. Biosensor and competitive growth were used in parallel to screen a S. cerevisiae CRISPR interference strain library. While fluorescence-activated cell sorting led to the isolation of cells with higher acetic acid retention and sensitivity, competitive growth assays allowed the identification of cells with higher acid tolerance. The results confirmed the role in acid stress response of genes involved in glycogen accumulation, chromatin modification, and mitochondrial or proteasomal functions. Two novel targets for improving tolerance were also identified: PAP1 and HIP1. Altogether, this thesis provides mechanistic insight into the stress response to lignocellulosic hydrolysates or weak acid inhibitors that limit yeast-mediated conversion of lignocellulosic biomass into biochemicals. Additionally, it offers new tools for the identification of strains with altered acetic acid tolerance.
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| 2. |
- Adams, Camiel, 1992, et al.
(författare)
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AN ADAPTIVE ISOGEOMETRIC CONTINUUM SHELL ELEMENT FOR EFFICIENT MODELLING OF DELAMINATION GROWTH
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To accurately predict damage growth in large, thin-walled composite structures, it is required to have models that are both valid and computational efficient. In this respect, isogeometric continuum shell elements provide an interesting option. First of all, the higher order continuity achieved via isogeometric analysis yields an increased in-plane smoothness that enable the use of larger shell elements. In addition, the high in-plane continuity also leads to that in-plane derivatives of in-plane stresses are continuous across element edges, thereby allowing for element-local recovery procedures for the prediction of out-of-plane stresses [2, 3]. Furthermore, as shown by Hosseini et al. [1], it is in an isogeometric continuum shell modelling framework rather straightforward to modify the through-thickness kinematics to incorporate weak and strong discontinuities. By introducing weak discontinuities at ply interfaces, the through-thickness strain discontinuities at these locations are explicitly accounted for. This enables a much better 3D strain and stress prediction, something which is key for a good estimation of the amount of intralaminar damage. By introducing strong discontinuities, the element is also capable to represent initiation and growth of one or several delamination cracks. In the current contribution, we extend the shell formulation from [1] into an adaptive continuum shell that allows for an update of the through-thickness kinematics at any required time instant during the simulation. The adaptivity is facilitated by that the through-thickness kinematical enrichment can be achieved by so-called ”knot insertion”, a step which can be fully automated due to the hierarchical nature of the isogeometric approximation functions. As a result, the current shell provides a good basis for an accurate but also computationally efficient prediction of the progressive failure in laminates, without a-priory knowledge of where damage will occur. Results show that the adaptive modelling framework works well, both to predict the full 3D stress states in multiaxial laminates, but also to capture growth of delaminations. Furthermore, in comparison to a fully resolved model, the adaptive approach gives significant time savings even for simple analyses where significant parts of the domain exhibit delamination growth. This implies that computational efforts (time and memory) can be considerably reduced when using this adaptive concept in large-scale analyses where damage develop only in a confined, but initially unknown area of the structure. [1] S. Hosseini, J.J.C. Remmers, C.V. Verhoosel, and R. de Borst (2015) Int. J. Numer. Meth. Eng., 102, 159–179. [2] M. Fagerström and J.J.C Remmers (2017) Adaptive modelling of delmination growth using isogeometric continuum shell elements. Proc. ICCM21, Xian, China. [3] J.-E. Dufour, P. Antolin, G. Sangalli, F. Auricchio, A. Reali (2018) Composites Part B: Engineering, 138, 12-18.
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| 3. |
- Campbell, Jonathan D., et al.
(författare)
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The REal Life EVidence AssessmeNt Tool (RELEVANT) : Development of a novel quality assurance asset to rate observational comparative effectiveness research studies
- 2019
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Ingår i: Clinical and Translational Allergy. - : Wiley. - 2045-7022. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence from observational comparative effectiveness research (CER) is ranked below that from randomized controlled trials in traditional evidence hierarchies. However, asthma observational CER studies represent an important complementary evidence source answering different research questions and are particularly valuable in guiding clinical decision making in real-life patient and practice settings. Tools are required to assist in quality appraisal of observational CER to enable identification of and confidence in high-quality CER evidence to inform guideline development. Methods: The REal Life EVidence AssessmeNt Tool (RELEVANT) was developed through a step-wise approach. We conducted an iterative refinement of the tool based on Task Force member expertise and feedback from pilot testing the tool until reaching adequate inter-rater agreement percentages. Two distinct pilots were conducted - the first involving six members of the Respiratory Effectiveness Group (REG) and European Academy of Allergy and Clinical Immunology (EAACI) joint Task Force for quality appraisal of observational asthma CER; the second involving 22 members of REG and EAACI membership. The final tool consists of 21 quality sub-items distributed across seven methodology domains: Background, Design, Measures, Analysis, Results, Discussion/Interpretation, and Conflict of Interest. Eleven of these sub-items are considered critical and named "primary sub-items". Results: Following the second pilot, RELEVANT showed inter-rater agreement ≥ 70% for 94% of all primary and 93% for all secondary sub-items tested across three rater groups. For observational CER to be classified as sufficiently high quality for future guideline consideration, all RELEVANT primary sub-items must be fulfilled. The ten secondary sub-items further qualify the relative strengths and weaknesses of the published CER evidence. RELEVANT could also be applicable to general quality appraisal of observational CER across other medical specialties. Conclusions: RELEVANT is the first quality checklist to assist in the appraisal of published observational CER developed through iterative feedback derived from pilot implementation and inter-rater agreement evaluation. Developed for a REG-EAACI Task Force quality appraisal of recent asthma CER, RELEVANT also has wider utility to support appraisal of CER literature in general (including pre-publication). It may also assist in manuscript development and in educating relevant stakeholders about key quality markers in observational CER.
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| 4. |
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| 5. |
- Chang, Bo, et al.
(författare)
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Self-transport and self-alignment of microchips using microscopic rain
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Alignment of microchips with receptors is an important process step in the construction of integrated micro- and nanosystems for emerging technologies, and facilitating alignment by spontaneous self-assembly processes is highly desired. Previously, capillary self-alignment of microchips driven by surface tension effects on patterned surfaces has been reported, where it was essential for microchips to have sufficient overlap with receptor sites. Here we demonstrate for the first time capillary self-transport and self-alignment of microchips, where microchips are initially placed outside the corresponding receptor sites and can be self-transported by capillary force to the receptor sites followed by self-alignment. The surface consists of hydrophilic silicon receptor sites surrounded by superhydrophobic black silicon. Rain-induced microscopic droplets are used to form the meniscus for the self-transport and self-alignment. The boundary conditions for the self-transport have been explored by modeling and confirmed experimentally. The maximum permitted gap between a microchip and a receptor site is determined by the volume of the liquid and by the wetting contrast between receptor site and substrate. Microscopic rain applied on hydrophilic-superhydrophobic patterned surfaces greatly improves the capability, reliability and error-tolerance of the process, avoiding the need for accurate initial placement of microchips, and thereby greatly simplifying the alignment process.
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| 6. |
- Fortes Brollo, Maria Eugenia, et al.
(författare)
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Combined Magnetoliposome Formation and Drug Loading in One Step for Efficient Alternating Current-Magnetic Field Remote-Controlled Drug Release.
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 12:4, s. 4295-4307
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a reproducible and facile one step strategy for the synthesis of doxorubicin loaded magnetoliposomes by using a thin-layer evaporation method. Liposomes of around 200 nm were made of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and iron oxide nanoparticles (NPs) with negative, positive, and hydrophobic surfaces that were incorporated outside, inside, or between the lipid bilayers, respectively. To characterize how NPs are incorporated in liposomes, advanced cryoTEM and atomic force microscope (AFM) techniques have been used. It was observed that only when the NPs are attached outside the liposomes, the membrane integrity is preserved (lipid melt transition shifts to 38.7 °C with high enthalpy 34.8 J/g) avoiding the leakage of the encapsulated drug while having good colloidal properties and the best heating efficiency under an alternating magnetic field (AMF). These magnetoliposomes were tested with two cancer cell lines, MDA-MB-231 and HeLa cells. First, 100% of cellular uptake was achieved with a high cell survival (above 80%), which is preserved (83%) for doxorubicin-loaded magnetoliposomes. Then, we demonstrate that doxorubicin release can be triggered by remote control, using a noninvasive external AMF for 1 h, leading to a cell survival reduction of 20%. Magnetic field conditions of 202 kHz and 30 mT seem to be enough to produce an effective heating to avoid drug degradation. In conclusion, these drug-loaded magnetoliposomes prepared in one step could be used for drug release on demand at a specific time and place, efficiently using an external AMF to reduce or even eliminate side effects.
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| 7. |
- Friberg, Ari T.
(författare)
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Partial polarization in arbitrary three-dimensional electromagnetic fields
- 2004
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Ingår i: Free And Guided Optical Beams. - SINGAPORE : WORLD SCIENTIFIC PUBL CO PTE LTD. - 9812389504 ; , s. 15-25
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Konferensbidrag (refereegranskat)abstract
- Although the theory of partial polarization of uniform electromagnetic beams is well-developed, it cannot be applied to random three-dimensional (3D) waves such as optical near fields. A general formulation of partial coherence and polarization in arbitrary 3D electromagnetic fields must be based on the 3 x 3 cross-spectral density tensors. After the fundamentals of electromagnetic coherence theory, we recall some recent researches on the spatial-coherence and spectral changes brought on by surface modes and evanescent waves. Partial polarization of arbitrary electromagnetic fields containing three orthogonal components is then addressed in terms of the 3 x 3 coherence matrix, and the variation of the 3D degree of polarization in near fields generated by semi-infinite thermal sources is analyzed. Finally, the similarities and differences of the conventional 2D and the new 3D formulations of partial polarization are briefly discussed.
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| 8. |
- Friberg, Anna
(författare)
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Towards Total Democracy?
- 2011
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Ingår i: The Creative Crisis of Democracy. - : Peter Lang Publishing Group. - 9789052017976 ; , s. 215-236
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
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| 10. |
- Friberg, Anneli
(författare)
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Why continuous usability testing can and should be part of regular library activity - from a UX librarian’s point of view
- 2017
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Ingår i: REVY. - Aarhus N, Denmark : Danish Research Library Association. - 1904-1969. ; 40:1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The interest for user experience (UX) and usability in libraries has grown rapidly over the past years and has now become an essential tool for developing and assessing a library’s digital services and physical spaces. At Linköping University Library (LiUB) we are slowly moving towards a user-centered culture, where users are being observed interacting with both physical and virtual spaces, but this article will only focus on the library’s online presence. The main objective is to argue for continuous usability testing as a part of regular library activity.
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