| 1. |
- Jansen, Severine, et al.
(author)
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Structure of Bombyx mori chemosensory protein 1 in solution
- 2007
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In: Archives of Insect Biochemistry and Physiology. - : Wiley. - 1520-6327 .- 0739-4462. ; 66:3, s. 135-145
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Journal article (peer-reviewed)abstract
- Chemosensory Proteins (CSPs) represent a family of conserved proteins found in insects that may be involved in chemosensory functions. BmorCSP1 is expressed mainly in antennae and legs of the silkworm moth Bombyx morii and was cloned from antennal cDNA. Here we report the determination of the structure of Bombyx mori CSP1 (BmorCSP1) by NMR. The overall fold of BmorCSP1 is globular and comprises six a-helices. These helices span residues 10-14, 17-27, 35-49, 57-72, 75-85, and 92-100. The internal hydrophobic sides of the helices are formed mostly by leucine and isoleucine residues and, therefore, well suited to constitute a binding site for hydrophobic ligands.
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| 2. |
- Armand, Michel, et al.
(author)
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Lithium-ion batteries – Current state of the art and anticipated developments
- 2020
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In: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 479
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Journal article (peer-reviewed)abstract
- Lithium-ion batteries are the state-of-the-art electrochemical energy storage technology for mobile electronic devices and electric vehicles. Accordingly, they have attracted a continuously increasing interest in academia and industry, which has led to a steady improvement in energy and power density, while the costs have decreased at even faster pace. Important questions, though, are, to which extent and how (fast) the performance can be further improved, and how the envisioned goal of truly sustainable energy storage can be realized. Herein, we combine a comprehensive review of important findings and developments in this field that have enabled their tremendous success with an overview of very recent trends concerning the active materials for the negative and positive electrode as well as the electrolyte. Moreover, we critically discuss current and anticipated electrode fabrication processes, as well as an essential prerequisite for “greener” batteries – the recycling. In each of these chapters, we eventually summarize important remaining challenges and propose potential directions for further improvement. Finally, we conclude this article with a brief summary of the performance metrics of commercial lithium-ion cells and a few thoughts towards the future development of this technology including several key performance indicators for the mid-term to long-term future.
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| 3. |
- Cullen, Nicholas C., et al.
(author)
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Efficacy assessment of an active tau immunotherapy in Alzheimer's disease patients with amyloid and tau pathology : a post hoc analysis of the “ADAMANT” randomised, placebo-controlled, double-blind, multi-centre, phase 2 clinical trial
- 2024
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In: EBioMedicine. - 2352-3964. ; 99
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Journal article (peer-reviewed)abstract
- Background: Tau pathology correlates with and predicts clinical decline in Alzheimer's disease. Approved tau-targeted therapies are not available. Methods: ADAMANT, a 24-month randomised, placebo-controlled, parallel-group, double-blinded, multicenter, Phase 2 clinical trial (EudraCT2015-000630-30, NCT02579252) enrolled 196 participants with Alzheimer's disease; 119 are included in this post-hoc subgroup analysis. AADvac1, active immunotherapy against pathological tau protein. A machine learning model predicted likely Amyloid+Tau+ participants from baseline MRI. Statistical methods: MMRM for change from baseline in cognition, function, and neurodegeneration; linear regression for associations between antibody response and endpoints. Results: The prediction model achieved PPV of 97.7% for amyloid, 96.2% for tau. 119 participants in the full analysis set (70 treatment and 49 placebo) were classified as A+T+. A trend for CDR-SB 104-week change (estimated marginal means [emm] = −0.99 points, 95% CI [−2.13, 0.13], p = 0.0825]) and ADCS-MCI-ADL (emm = 3.82 points, CI [−0.29, 7.92], p = 0.0679) in favour of the treatment group was seen. Reduction was seen in plasma NF-L (emm = −0.15 log pg/mL, CI [−0.27, −0.03], p = 0.0139). Higher antibody response to AADvac1 was related to slowing of decline on CDR-SB (rho = −0.10, CI [−0.21, 0.01], p = 0.0376) and ADL (rho = 0.15, CI [0.03, 0.27], p = 0.0201), and related to slower brain atrophy (rho = 0.18–0.35, p < 0.05 for temporal volume, whole cortex, and right and left hippocampus). Conclusions: In the subgroup of ML imputed or CSF identified A+T+, AADvac1 slowed AD-related decline in an antibody-dependent manner. Larger anti-tau trials are warranted. Funding: AXON Neuroscience SE.
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| 4. |
- Flores, Eibar, et al.
(author)
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Cation Ordering and Redox Chemistry of Layered Ni-Rich LixNi1-2yCoyMnyO2 : An Operando Raman Spectroscopy Study
- 2020
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In: Chemistry of Materials. - : AMER CHEMICAL SOC. - 0897-4756 .- 1520-5002. ; 32:1, s. 186-194
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Journal article (peer-reviewed)abstract
- Although layered transition metal oxides are state-of-the-art cathode active materials for Li-ion batteries, many fundamental aspects of their operation are poorly understood, in particular, how the local lattice structure and transition metal composition influence their electrochemical activity. In this work, the local structure and redox activity of Ni-rich LixNi1-2yCoyMnyO2 (y = 0.1, 0.2, and 0.33, abbreviated as NCM811, NCM622, and NCM111, respectively) Li-ion cathodes are characterized under standard and overcharge operating conditions with a recently developed operando Raman spectroscopy methodology. Supported by DFT phonon calculations and advanced data analysis methods, we demonstrate that the Raman spectra of NCMs entail spectroscopic signatures of cation ordering phenomena, sequential oxidation/reduction of nickel, and participation of bulk lattice oxygen in the charge-compensation process at a low state of lithiation (SOL). Our methodology enables monitoring such processes during cycling and offers the potential for investigating the mechanisms by which certain strategies (i.e., doping, surface coatings, etc.) ameliorate electrochemical performance.
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| 5. |
- Flores, Eibar, et al.
(author)
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Elucidation of LixNi0.8Co0.15Al0.05O2 Redox Chemistry by Operando Raman Spectroscopy
- 2018
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In: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 30:14, s. 4694-4703
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Journal article (peer-reviewed)abstract
- The local structure evolution of LixNi0.8Co0.15Al0.05O2 (NCA) is linked to its electrochemical response during cycling (and overcharge) by operando Raman spectroscopy with findings supported by complementary techniques, such as online electrochemical mass spectrometry (OEMS) and density functional theory (DFT) phonon calculations. The vibrational motion of lattice oxygens is observed to be highly dependent on the local LixMO2 lattice environment, e.g. M—O bonding strength/length and state of lithiation x. All vibrational modes generally harden upon delithiation due to M—O bond character (ionic → covalent) evolution (disregarding an early bond softening due to Li+ vacancy formation) and evidence the important influence of the local structural lattice configuration on the electrochemical response of NCA. Although the intensities of all Raman active bands generally increase upon delithiation, a major inflection point at x = 0.2 marks the onset of a partly irreversible fundamental transition within NCA that is most likely related to electron removal from MO bonding states and partial oxidation of oxygen sublattice, which is also indicated by the observed concomitant O2 release from the particle surface. Operando Raman spectroscopy with higher time resolution provides unique possibilities for detailed studies of how chemical parameters (Li+ vacancy formation, transition metal cation concentration, and lattice doping, etc.) may govern the onset and nature of processes (such as bond character evolution and stability) that define the performance of the LixMO2 class of oxides. The further insights thus gained can be exploited to guide the development of next-generation layered cathodes for Li-ion batteries operating stably at higher voltages and capacities.
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| 6. |
- Flores, Eibar, et al.
(author)
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In situ and Operando Raman Spectroscopy of Layered Transition Metal Oxides for Li-ion Battery Cathodes
- 2018
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In: FRONTIERS IN ENERGY RESEARCH. - : FRONTIERS MEDIA SA. - 2296-598X. ; 6
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Journal article (peer-reviewed)abstract
- In situ and operando Raman spectroscopy is proposed to provide unique means for deeper fundamental understanding and further development of layered transition metal LiMO2 (M = Ni, Co, Mn) oxides suitable for Li-ion battery applications. We compare several spectro-electrochemical cell designs and suggest key experimental parameters for obtaining optimum electrochemical performance and spectral quality. Studies of the most practically relevant LiMO2 compositions are exemplified with particular focus on two experimental approaches: (1) lateral and axial Raman mapping of the electrode's (near-) surface to monitor inhomogeneous electrode reactions and (2) time-dependent single-particle spectra during cycling to analyze the LixMO2 lattice dynamics as a function of lithium content. Raman Spectroscopy is claimed to provide a unique real-time probe of the M-O bonds, which are at the heart of the electrochemistry of LiMO2 oxides and govern their stability. We highlight the need for further fundamental understanding of the relationships between the spectroscopic response and oxide lattice structure with particular emphasis on the development of a theoretical framework linking the position and intensity of the Raman bands to the local LixMO2 lattice con figuration. The use of complementary experimental techniques and model systems for validation also deserve further attention. Several novel LiMO2 compositions are currently being explored, especially containing dopings and coatings, and Raman spectroscopy could offer a highly dynamic and convenient tool to guide the formulation of high specific charge and long cycle life LiMO2 oxides for next-generation Li-ion battery cathodes.
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| 7. |
- Goktas, Mustafa, et al.
(author)
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Stable and Unstable Diglyme-Based Electrolytes for Batteries with Sodium or Graphite as Electrode
- 2019
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In: ACS Applied Materials and Interfaces. - 1944-8244 .- 1944-8252. ; 11:36, s. 32844-32855
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Journal article (peer-reviewed)abstract
- We study the stability of several diglyme-based electrolytes in sodium|sodium and sodium|graphite cells. The electrolyte behavior for different conductive salts [sodium trifluoromethanesulfonate (NaOTf), NaPF6, NaClO4, bis(fluorosulfonyl)imide (NaFSI), and sodium bis(trifluoromethanesulfonyl)imide (NaTFSI)] is compared and, in some cases, considerable differences are identified. Side reactions are studied with a variety of methods, including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, online electrochemical mass spectrometry, and in situ electrochemical dilatometry. For Na|Na symmetric cells as well as for Na|graphite cells, we find that NaOTf and NaPF6 are the preferred salts followed by NaClO4 and NaFSI, as the latter two lead to more side reactions and increasing impedance. NaTFSI shows the worst performance leading to poor Coulombic efficiency and cycle life. In this case, excessive side reactions lead also to a strong increase in electrode thickness during cycling. In a qualitative order, the suitability of the conductive salts can be ranked as follows: NaOTf >= NaPF6 > NaClO4 > NaFSI >> NaTFSI. Our results also explain two recent, seemingly conflicting findings on the degree of solid electrolyte interphase formation on graphite electrodes in sodium-ion batteries [Maibach, J.; ACS Appl. Mater. Interfaces 2017, 9, 12373-12381; Goktas, M.; Adv. Energy Mater. 2018, 8, 1702724]. The contradictory findings are due to the different conductive salts used in both studies.
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| 8. |
- He, Minglong, et al.
(author)
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Towards more Durable Electrochemical Capacitors by Elucidating the Ageing Mechanisms under Different Testing Procedures
- 2019
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In: ChemElectroChem. - : WILEY-V C H VERLAG GMBH. - 2196-0216. ; 6:2, s. 566-573
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Journal article (peer-reviewed)abstract
- Electrical double-layer capacitors (EDLCs) commonly denoted supercapacitors are rechargeable energy storage devices with excellent power and energy delivery metrics intermediate to conventional capacitors and batteries. High-voltage aqueous electrolyte based EDLCs are particularly attractive due to their high-power capability, facile production, and environmental advantages. EDLCs should last for thousands of cycles and evaluation of future cell chemistries require long-term and costly galvanostatic cycling. Voltage holding tests have been proposed to shorten evaluation time by accelerating cell degradation processes. Whether voltage holding can replace cycling completely remains undemonstrated. In this work, a systematic investigation of the influence of testing procedure on cell performance is presented. The state-of-the-art post-mortem and operando experimental techniques are implemented to elucidate ageing mechanisms and kinetics inside EDLC cells under different testing procedures. Carbon corrosion occurring on the positively polarized electrode leads to the lower active surface area and higher oxygen content. On the contrary, an increase of surface area and micropore volume are observed on the negatively polarized electrode. Repeated galvanostatic cycles at U<1.6 V appears to facilitate the depletion of oxygen species on the positively polarized electrode in comparison with voltage holding, which indicates a more complex degradation mechanism during cycling. Caution is advised when comparing results from different test procedures.
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| 9. |
- Karlsson, Christoffer, 1986-
(author)
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Conducting Redox Polymers for Electrical Energy Storage : Backbone - Substituent Interactions in Quinone Polypyrrole Model Systems
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- Organic electrical energy storage (EES) is a growing field of research that is expected to play an important role in the future, as the need for sustainable EES increases. Conducting redox polymers (CRPs), i.e. conducting polymers with incorporated redox active moieties e.g. as pendant groups (PGs), are proposed as a promising class of compounds for this purpose. Redox cycling of the PGs can be utilized for high charge storage capacity, while the conducting polymer backbone provides fast charge transport through the material. Some of the major challenges with small-molecule systems for EES could be solved by using CRPs, e.g. capacity fading due to dissolution of the active compound, and high resistance due to slow charge transport between molecules. The latter issue is often solved by adding large amounts of conducting additives to the active material, drastically lowering the specific capacity. In this project, CRPs are shown to be able to function in battery cells without any additives, making both high capacity and high power possible. Although several CRPs have been reported in the literature, very few detailed studies have been conducted on the electrochemical processes of the two systems (i.e. the conducting polymer backbone and the redox active PGs). An important factor to consider in CRP design is the possibility for interaction between the two redox systems, which could be either beneficial or detrimental to the function as EES material. In this thesis, CRP model systems composed of hydroquinone functionalized polypyrrole have been studied, and they exhibit separate redox reactions for the PGs and the backbone, overlapping in potential. Significant interaction between them was observed, as oxidation of the PGs has severe impact on the backbone: When the oxidized and hydrophobic p-benzoquinone PGs are formed, they pack and force the polymer backbone to twist, localizing the bipolarons, and decreasing the conductivity. This is accompanied by a contraction of the polymer film and expulsion of electrolyte. Overall, the interaction in these polymers is destructive for their EES function, and it could be eliminated by introduction of a long linker unit between the PGs and the backbone.
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| 10. |
- Karnkowska, Anna, et al.
(author)
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The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion
- 2019
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In: Molecular biology and evolution. - : OXFORD UNIV PRESS. - 0737-4038 .- 1537-1719. ; 36:10, s. 2292-2312
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Journal article (peer-reviewed)abstract
- The discovery that the protist Monocercomonoides exilis completely lacks mitochondria demonstrates that these organelles are not absolutely essential to eukaryotic cells. However, the degree to which the metabolism and cellular systems of this organism have adapted to the loss of mitochondria is unknown. Here, we report an extensive analysis of the M. exilis genome to address this question. Unexpectedly, we find that M. exilis genome structure and content is similar in complexity to other eukaryotes and less "reduced" than genomes of some other protists from the Metamonada group to which it belongs. Furthermore, the predicted cytoskeletal systems, the organization of endomembrane systems, and biosynthetic pathways also display canonical eukaryotic complexity. The only apparent preadaptation that permitted the loss of mitochondria was the acquisition of the SUF system for Fe-S cluster assembly and the loss of glycine cleavage system. Changes in other systems, including in amino acid metabolism and oxidative stress response, were coincident with the loss of mitochondria but are likely adaptations to the microaerophilic and endobiotic niche rather than the mitochondrial loss per se. Apart from the lack of mitochondria and peroxisomes, we show that M. exilis is a fully elaborated eukaryotic cell that is a promising model system in which eukaryotic cell biology can be investigated in the absence of mitochondria.
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