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1.	Moberg, Christina, et al. (författare) De unga gör helt rätt när de stämmer staten 2022 Ingår i: Aftonbladet. - 1103-9000. Tidskriftsartikel (populärvet., debatt m.m.)abstract 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
2.	Hsiao, Ching-Lien, et al. (författare) Composition tunable Al1-xInxN nanorod arrays grown by ultra-high-vacuum magnetron sputter epitaxy 2011 Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Self-assembled ternary Al1-xInxN nanorod arrays with variable In concentration, 0.10 ≤ x ≤ 0.32 have been realized onto c-plane sapphire substrates by ultra-high-vacuum magnetron sputter epitaxy with Ti0.21Zr0.79N or VN seed layers assistance. The formation of nanorods was very sensitive to the applied seed layer. Without proper seed layer assistance a continuous Al1-xInxN film was grown. The nanorods exhibit hexagonal crosssections with preferential growth along the c axis. A coaxial rod structure with higher In concentration in the core was observed by (scanning) transmission electron microscopy in combination with low-loss electron energy loss spectroscopy and energy dispersive xray spectroscopy. 5 K cathodoluminescence spectroscopy of Al0.86In0.14N nanorods revealed band edge emission at ~5.46 eV, which was accompanied by a strong defectrelated emission at ~ 3.38 eV.
3.	Hsiao, Ching-Lien, et al. (författare) Spontaneous Formation of AlInN Core–Shell Nanorod Arrays by Ultrahigh-Vacuum Magnetron Sputter Epitaxy 2011 Ingår i: Applied Physics Express. - : Japan Society of Applied Physics. - 1882-0786. ; 4:115002 Tidskriftsartikel (refereegranskat)abstract The spontaneous formation of AlInN core–shell nanorod arrays with variable In concentration has been realized by ultrahigh-vacuum magnetron sputter epitaxy with Ti0.21Zr0.79N or VN seed layer assistance. The nanorods exhibit hexagonal cross sections with preferential growth along the c-axis. A core–shell rod structure with a higher In concentration in the core was observed by (scanning) transmission electron microscopy in combination with low-loss electron energy loss spectroscopy and energy dispersive X-ray spectroscopy. 5 K cathodoluminescence spectroscopy of Al0.86In0.14N nanorods revealed band edge emission at ∼5.46 eV, which was accompanied by a strong defect-related emission at ∼3.38 eV
4.	Ding, Haoming, et al. (författare) Chemical scissor-mediated structural editing of layered transition metal carbides 2023 Ingår i: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 379:6637, s. 1130-1135 Tidskriftsartikel (refereegranskat)abstract Intercalated layered materials offer distinctive properties and serve as precursors for important two-dimensional (2D) materials. However, intercalation of non-van der Waals structures, which can expand the family of 2D materials, is difficult. We report a structural editing protocol for layered carbides (MAX phases) and their 2D derivatives (MXenes). Gap-opening and species-intercalating stages were respectively mediated by chemical scissors and intercalants, which created a large family of MAX phases with unconventional elements and structures, as well as MXenes with versatile terminals. The removal of terminals in MXenes with metal scissors and then the stitching of 2D carbide nanosheets with atom intercalation leads to the reconstruction of MAX phases and a family of metal-intercalated 2D carbides, both of which may drive advances in fields ranging from energy to printed electronics.
5.	Ding, Haoming, et al. (författare) Synthesis of MAX phases Nb2CuC and Ti2(Al0.1Cu0.9)N by A-site replacement reaction in molten salts 2019 Ingår i: Materials Research Letters. - : Taylor & Francis. - 2166-3831. ; 7:12, s. 510-516 Tidskriftsartikel (refereegranskat)abstract New MAX phases Ti2(AlxCu1−x)N and Nb2CuC were synthesized by A-site replacement by reacting Ti2AlN and Nb2AlC, respectively, with CuCl2 or CuI molten salt. X-ray diffraction, scanning electron microscopy, and atomically resolved scanning transmission electron microscopy showed complete A-site replacement in Nb2AlC, which lead to the formation of Nb2CuC. However, the replacement of Al in Ti2AlN phase was only close to complete at Ti2(Al0.1Cu0.9)N. Density-functional theory calculations corroborated the structural stability of Nb2CuC and Ti2CuN phases. Moreover, the calculated cleavage energy in these Cu-containing MAX phases are weaker than in their Al-containing counterparts.The preparation of MAX phases Nb2CuC and Ti2(Al0.1Cu0.9)N were realized by A-site replacement in Ti2AlN and Nb2AlN, respectively.
6.	Eklund, Per, et al. (författare) Structural, electrical, and mechanical properties of nc-TiC/a-SiC nanocomposite thin films 2005 Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 23:6, s. 2486-2495 Tidskriftsartikel (refereegranskat)abstract We have synthesized Ti–Si–C nanocomposite thin films by dc magnetron sputtering from a Ti3SiC2 compound target in an Ar discharge on Si(100), Al2O3(0001), and Al substrates at temperatures from room temperature to 300 °C. Electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy showed that the films consisted of nanocrystalline (nc-) TiC and amorphous (a-) SiC, with the possible presence of a small amount of noncarbidic C. The growth mode was columnar, yielding a nodular film-surface morphology. Mechanically, the films exhibited a remarkable ductile behavior. Their nanoindentation hardness and E-modulus values were 20 and 290 GPa, respectively. The electrical resistivity was 330 µ cm for optimal Ar pressure (4 mTorr) and substrate temperature (300 °C). The resulting nc-TiC/a-SiC films performed well as electrical contact material. These films' electrical-contact resistance against Ag was remarkably low, 6 µ at a contact force of 800 N compared to 3.2 µ for Ag against Ag. The chemical stability of the nc-TiC/a-SiC films was excellent, as shown by a Battelle flowing mixed corrosive-gas test, with no N, Cl, or S contaminants entering the bulk of the films.
7.	Frodelius, Jenny, et al. (författare) Direct current magnetron sputtering from a Ti2AlC target Annan publikation (övrigt vetenskapligt/konstnärligt)
8.	Frodelius, Jenny, et al. (författare) Sputter deposition from a Ti2AlC target: Process characterization and conditions for growth of Ti2AlC 2010 Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 518:6, s. 1621-1626 Tidskriftsartikel (refereegranskat)abstract Sputter deposition from a Ti2AlC target was found to yield Ti-Al-C films with a composition that deviates from the target composition of 2:1:1. For increasing substrate temperature from ambient to 1000 degrees C, the Al content decreased from 22 at.% to 5 at.%, due to re-evaporation. The C content in as-deposited films was equal to or higher than the Ti content. Mass spectrometry of the plasma revealed that the Ti and Al species were essentially thermalized, while a large fraction of C with energies andgt;4 eV was detected. Co-sputtering with Ti yielded a film stoichiometry of 2:0.8:0.9 for Ti:Al:C, which enabled growth of Ti2AlC. These results indicate that an additional Ti flux balances the excess C and therefore provides for more stoichiometric Ti2AlC synthesis conditions.
9.	Ganowiak, Katarzyna, et al. (författare) Fibrils from Synthetic Amyloid-Related Peptides Enhance Development of Experimental AA-Amyloidosis in Mice 1994 Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 199:1, s. 306-312 Tidskriftsartikel (refereegranskat)abstract Amyloid enhancing factor is an incompletely characterized activity of extracts from many amyloid-containing tissues and which greatly shortens the preamyloidotic phase during experimental induction of AA-amyloidosis. In this communication we show that amyloid-like fibrils made in vitro from synthetic peptides, corresponding to segments of amyloid fibril proteins, have amyloid enhancing factor-like activity. Thus, there is a possibility that amyloid enhancing factor activity depends on small fibrils serving as nucleation centers for fibril elongation.
10.	Hsiao, Ching-Lien, et al. (författare) Curved-lattice epitaxial growth of chiral AlInN twisted nanorods for optical applications 2012 Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Despite of using chiral metamaterials to manipulate light polarization states has been demonstrated their great potential for applications such as invisible cloaks, broadband or wavelength-tunable circular polarizers, microreflectors, etc. in the past decade [1-6], operating wavelength in ultraviolet-visible range is still a challenge issue. Since these chiral structures often consist of metallic materials, their operation is designed for the infrared and microwave regions [2-4]. Here, we show how a controlled curved-lattice epitaxial growth (CLEG) of wide-bandgap AlInN semiconductor curved nanocrystals [7] can be exploited as a novel route for tailoring chiral nanostructures in the form of twisted nanorods (TNRs). The fabricated TNRs are shown to reflect light with a high degree of polarization as well as a high degree of circular polarization (that is, nearly circularly polarized light) in the ultravioletvisible region. The obtained polarization is shown to be dependent on the handedness of the TNRs.
11.	Hsiao, Ching-Lien, et al. (författare) Curved-Lattice Epitaxial Growth of InxAl1-xN Nanospirals with Tailored Chirality 2015 Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 15:1, s. 294-300 Tidskriftsartikel (refereegranskat)abstract Chirality, tailored by external morphology and internal composition, has been realized by controlled curved-lattice epitaxial growth (CLEG) of uniform coatings of single-crystalline InxAl1-xN nanospirals. The nanospirals are formed by sequentially stacking segments of curved nanorods on top of each other, where each segment is incrementally rotated around the spiral axis. By controlling the growth rate, segment length, rotation direction, and incremental rotation angle, spirals are tailored to predetermined handedness, pitch, and height. The curved morphology of the segments is a result of a lateral compositional gradient across the segments while maintaining a preferred crystallographic growth direction, implying a lateral gradient in optical properties as well. Left- and right-handed nanospirals, tailored with 5 periods of 200 nm pitch, as confirmed by scanning electron microscopy, exhibit uniform spiral diameters of ~80 nm (local segment diameters of ~60 nm) with tapered hexagonal tips. High resolution electron microscopy, in combination with nanoprobe energy dispersive X-ray spectroscopy and valence electron energy loss spectroscopy, show that individual nanospirals consist of an In-rich core with ~15 nm-diameter hexagonal cross-section, comprised of curved basal planes. The core is surrounded by an Al-rich shell with a thickness asymmetry spiraling along the core. The ensemble nanospirals, across the 1 cm2 wafers, show high in-plane ordering with respect to shape, crystalline orientation, and direction of compositional gradient. Mueller matrix spectroscopic ellipsometry shows that the tailored chirality is manifested in the polarization state of light reflected off the CLEG nanospiral-coated wafers. In that, the polarization state is shown to be dependent on the handedness of the nanospirals and the wavelength of the incident light in the ultraviolet-visible region.
12.	Hsiao, Ching-Lien, et al. (författare) Nucleation and core-shell formation mechanism of self-induced InxAl1−xN core-shell nanorods grown on sapphire substrates by magnetron sputter epitaxy 2016 Ingår i: Vacuum. - : Pergamon Press. - 0042-207X .- 1879-2715. ; 131, s. 39-43 Tidskriftsartikel (refereegranskat)abstract Nucleation of self-induced nanorod and core-shell structure formation by surface-induced phase separation have been studied at the initial growth stage. The growth of well-separated core shell nanorods is only found in a transition temperature region (600 degrees C amp;lt;= T amp;lt;= 800 degrees C) in contrast to the result of thin film growth outside this region (T amp;lt; 600 degrees C or T amp;gt; 800 degrees C). Formation of multiple compositional domains, due to phase separation, after similar to 20 nm InxAl1-xN epilayer growth from sapphire substrate promotes the core-shell nanorod growth, showing a modified Stranski-Krastanov growth mode. The use of VN seed layer makes the initial growth of the nanorods directly at the substrate interface, revealing a Volmer-Weber growth mode. Different compositional domains are found on VN template surface to support that the phase separation takes place at the initial nucleation process and forms by a self-patterning effect. The nanorods were grown from In-rich domains and initiated the formation of core-shell nanorods due to spinodal decomposition of the InxAl1-xN alloy with a composition in the miscibility gap.
13.	Hsu, Chih-Wei, et al. (författare) Controlled Growth of GaN Pyramidal template hosting InGaN Quantum Dots Annan publikation (övrigt vetenskapligt/konstnärligt)abstract The emission properties of InGaN grown on hexagonal GaN pyramids with various pitch distances (PD) are studied. Emissions associated with InGaN quantum wells (QWs) and InGaN quantum dots (QDs) can be identified. The emission energies of InGaN QWs and QDs shift toward opposite directions with increasing PD; red-shift for QWs and blue-shift for QDs. Based on the source supply mechanism in a selective area growth process, the formation of InGaN QDs on GaN pyramids is believed to be a combined effect of Stranski-Krastanow growth mode and spinodal decomposition taking place at the microscopic (0001) surfaces on GaN pyramids.
14.	Hultman, Johan, et al. (författare) Hållbara hem i växande städer 2004 Ingår i: Miljö och hållbar utveckling. - 9144031432 ; , s. 337-360 Bokkapitel (övrigt vetenskapligt/konstnärligt)
15.	Johan, Katarzyna, et al. (författare) Acceleration of amyloid protein A amyloidosis by amyloid-like synthetic fibrils 1998 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 95:5, s. 2558-2563 Tidskriftsartikel (refereegranskat)abstract Amyloid protein A (AA) amyloidosis is a consequence of some long-standing inflammatory conditions, and subsequently, an N-terminal fragment of the acute phase protein serum AA forms β-sheet fibrils that are deposited in different tissues. It is unknown why only some individuals develop AA amyloidosis. In the mouse model, AA amyloidosis develops after ≈25 days of inflammatory challenge. This lag phase can be shortened dramatically by administration of a small amount of amyloid extract containing an as yet undefined amyloid-enhancing factor. In the present study, we show that preformed amyloid-like fibrils made from short synthetic peptides corresponding to parts of several different amyloid fibril proteins exert amyloidogenic enhancing activity when given i.v. to mice at the induction of inflammation. We followed i.v. administered, radiolabeled, heterologous, synthetic fibrils to the lung and to the perifollicular area in the spleen and found that new AA–amyloid fibrils developed on these preformed fibrils. Our findings thus show that preformed, synthetic, amyloid-like fibrils have an in vivo nidus activity and that amyloid-enhancing activity may occur, at least in part, through this mechanism. Our findings also show that fibrils of a heterologous chemical nature exert amyloid-enhancing activity.
16.	Junaid, Muhammad, et al. (författare) Epitaxial Growth of GaN (0001)/Al2O3 (0001) by Reactive High Power Impulse Magnetron Sputter Deposition Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Epitaxial GaN (0001) thin films were grown on Al2O3 (0001) substrates by reactive high power impulse magnetron sputtering of liquid Ga targets in a mixed N2/Ar discharge. A combination of x-ray diffraction, electron microscopy, atomic force microscopy, μ-Raman mapping and spectroscopy, μ-photoluminescence, time of flight elastic recoil detection, and cathodoluminescence showed the formation of relaxed and strained domains in the same films. While the strained domains form due to ion bombardment during growth, the relaxed domains exhibit
17.	Khatibi, Ali, et al. (författare) Face-Centered Cubic (Al1-xCrx)2O3 2011 Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 519:8, s. 2426-2429 Tidskriftsartikel (refereegranskat)abstract We report the discovery of a face-centered cubic (Al1−xCrx)2O3 solid solution [0.60bxb0.70] in films grownonto Si substrates using reactive radio frequency magnetron sputtering from Al and Cr targets at 400 °C. Theproposed structure is NaCl-like with 33% vacancies on the metal sites. The unit cell parameter is 4.04 Å asdetermined by X-ray diffraction. The films have a b100N preferred crystallographic orientation and exhibithardness values up to 26 GPa and an elastic modulus of 220–235 GPa.
18.	Lai, Chung-Chuan, et al. (författare) Phase formation of nanolaminated Mo2AuC and Mo-2(Au1-xGax)(2)C by a substitutional reaction within Au-capped Mo2GaC and Mo2Ga2C thin films 2017 Ingår i: Nanoscale. - : ROYAL SOC CHEMISTRY. - 2040-3364 .- 2040-3372. ; 9:45, s. 17681-17687 Tidskriftsartikel (refereegranskat)abstract Au-containing nanolaminated carbides Mo2AuC and Mo-2(Au1-xGax)(2)C were synthesized by a thermally induced substitutional reaction in Mo2GaC and Mo2Ga2C, respectively. The Au substitution of the Ga layers in the structures was observed using cross-sectional high-resolution scanning transmission electron microscopy. Expansion of c lattice parameters was also observed in the Au-containing phases compared to the original phases. Energy dispersive spectroscopy detected residual Ga in Au-substituted layers of both phases with a peculiar Ga in-plane ordering for Au : Ga = 9 : 1 ratio along the Au-Ga layers in Mo-2(Au1-xGax)(2)C. These results indicate a generalization of the Au substitution reaction for the A elements in MAX phases.
19.	Li, Mian, et al. (författare) Element Replacement Approach by Reaction with Lewis Acidic Molten Salts to Synthesize Nanolaminated MAX Phases and MXenes 2019 Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126. ; 141:11, s. 4730-4737 Tidskriftsartikel (refereegranskat)abstract Nanolaminated materials are important because of their exceptional properties and wide range of applications. Here, we demonstrate a general approach to synthesizing a series of Zn-based MAX phases and Cl-terminated MXenes originating from the replacement reaction between the MAX phase and the late transition-metal halides. The approach is a top-down route that enables the late transitional element atom (Zn in the present case) to occupy the A site in the pre-existing MAX phase structure. Using this replacement reaction between the Zn element from molten ZnCl2 and the Al element in MAX phase precursors (Ti3AlC2, Ti2AlC, Ti2AlN, and V2AlC), novel MAX phases Ti3ZnC2, Ti2ZnC, Ti2ZnN, and V2ZnC were synthesized. When employing excess ZnCl2, Cl-terminated MXenes (such as Ti3C2Cl2 and Ti2CCl2) were derived by a subsequent exfoliation of Ti3ZnC2 and Ti2ZnC due to the strong Lewis acidity of molten ZnCl2. These results indicate that A-site element replacement in traditional MAX phases by late transition-metal halides opens the door to explore MAX phases that are not thermodynamically stable at high temperature and would be difficult to synthesize through the commonly employed powder metallurgy approach. In addition, this is the first time that exclusively Cl-terminated MXenes were obtained, and the etching effect of Lewis acid in molten salts provides a green and viable route to preparing MXenes through an HF-free chemical approach.
20.	Li, Mian, et al. (författare) Halogenated Ti3C2 MXenes with Electrochemically Active Terminals for High-Performance Zinc Ion Batteries 2021 Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 15:1, s. 1077-1085 Tidskriftsartikel (refereegranskat)abstract The class of two-dimensional metal carbides and nitrides known as MXenes offer a distinct manner of property tailoring for a wide range of applications. The ability to tune the surface chemistry for expanding the property space of MXenes is thus an important topic, although experimental exploration of surface terminals remains a challenge. Here, we synthesized Ti3C2 MXene with unitary, binary, and ternary halogen terminals, e.g., -Cl, -Br, -I, -BrI, and -ClBrI, to investigate the effect of surface chemistry on the properties of MXenes. The electrochemical activity of Br and I elements results in the extraordinary electrochemical performance of the MXenes as cathodes for aqueous zinc ion batteries. The -Br- and -I-containing MXenes, e.g., Ti3C2Br2 and Ti3C2I2, exhibit distinct discharge platforms with considerable capacities of 97.6 and 135 mA.g(-1). Ti3C2 (BrI) and Ti3C2 (ClBrI) exhibit dual discharge platforms with capacities of 117.2 and 106.7 mAh.g(-1). In contrast, the previously discovered MXenes Ti3C2Cl2 and Ti3C2 (OF) exhibit no discharge platforms and only similar to 50% of capacities and energy densities of Ti3C2Br2. These results emphasize the effectiveness of the Lewis-acidic-melt etching route for tuning the surface chemistry of MXenes and also show promise for expanding the MXene family toward various applications.
21.	Li, Youbing, et al. (författare) A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte 2020 Ingår i: Nature Materials. - : NATURE PUBLISHING GROUP. - 1476-1122 .- 1476-4660. ; 19:8, s. 894-899 Tidskriftsartikel (refereegranskat)abstract Two-dimensional transition metal carbides and nitrides, known as MXenes, are currently considered as energy storage materials. A generic Lewis acidic etching route for preparing high-rate negative-electrode MXenes with enhanced electrochemical performance in non-aqueous electrolyte is now proposed. Two-dimensional carbides and nitrides of transition metals, known as MXenes, are a fast-growing family of materials that have attracted attention as energy storage materials. MXenes are mainly prepared from Al-containing MAX phases (where A = Al) by Al dissolution in F-containing solution; most other MAX phases have not been explored. Here a redox-controlled A-site etching of MAX phases in Lewis acidic melts is proposed and validated by the synthesis of various MXenes from unconventional MAX-phase precursors with A elements Si, Zn and Ga. A negative electrode of Ti3C2 MXene material obtained through this molten salt synthesis method delivers a Li+ storage capacity of up to 738 C g(-1) (205 mAh g(-1)) with high charge-discharge rate and a pseudocapacitive-like electrochemical signature in 1 M LiPF6 carbonate-based electrolyte. MXenes prepared via this molten salt synthesis route may prove suitable for use as high-rate negative-electrode materials for electrochemical energy storage applications.
22.	Li, Youbing, et al. (författare) A-site alloying-guided universal design of noble metal-based MAX phases 2024 Ingår i: Matter. - : Cell Press. - 2590-2393 .- 2590-2385. ; 7:2, s. 523-538 Tidskriftsartikel (refereegranskat)abstract Mn+1AXn (MAX) phases have attracted significant attention due to their structural diversity and potential applications. Designing MAX phases with single-atom-thick A layers featuring 4d/5d-orbital electronic elements is interesting work. Here, we present a comprehensive report on noble metal-based M2(A1-xA′x)C (M = V, Ti, Nb; A = Al, Sn, In, Ga, Ge; A′ = Ru, Rh, Pd, Ir, Pt, Au and combinations thereof; 0 < x ≤ 0.4) phases featuring A sublayers of 4d/5d-orbital electronic elements through an A-site alloying strategy. The chemical composition of MAX phases can be adjusted by selecting different M- and A-site elements, with morphology tailored by distinct C sources. Furthermore, the V2(Sn0.8Pt0.2)C (15.7 wt % Pt) catalyst showed better performance for hydrogen evolution reaction compared to the commercial Pt/C (20 wt % Pt) electrode. This study highlights the prospects of A-site alloying for the design of novel MAX phases with unique properties and promising applications in electrocatalysis and beyond.
23.	Li, Youbing, et al. (författare) Electrochemical Lithium Storage Performance of Molten Salt Derived V2SnC MAX Phase 2021 Ingår i: Nano-Micro Letters. - : Springer. - 2311-6706 .- 2150-5551. ; 13:1 Tidskriftsartikel (refereegranskat)abstract MAX phases are gaining attention as precursors of two-dimensional MXenes that are intensively pursued in applications for electrochemical energy storage. Here, we report the preparation of V2SnC MAX phase by the molten salt method. V2SnC is investigated as a lithium storage anode, showing a high gravimetric capacity of 490 mAh g(-1) and volumetric capacity of 570 mAh cm(-3) as well as superior rate performance of 95 mAh g(-1) (110 mAh cm(-3)) at 50 C, surpassing the ever-reported performance of MAX phase anodes. Supported by operando X-ray diffraction and density functional theory, a charge storage mechanism with dual redox reaction is proposed with a Sn-Li (de)alloying reaction that occurs at the edge sites of V2SnC particles where Sn atoms are exposed to the electrolyte followed by a redox reaction that occurs at V2C layers with Li. This study offers promise of using MAX phases with M-site and A-site elements that are redox active as high-rate lithium storage materials.
24.	Li, Youbing, et al. (författare) Multielemental single atom-thick A layers in nanolaminated V2(Sn, A) C (A = Fe, Co, Ni, Mn) for tailoring magnetic properties 2020 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 117:2, s. 820-825 Tidskriftsartikel (refereegranskat)abstract Tailoring of individual single-atom-thick layers in nanolaminated materials offers atomic-level control over material properties. Nonetheless, multielement alloying in individual atomic layers in nanolaminates is largely unexplored. Here, we report 15 inherently nanolaminated V-2(A(x)Sn(1-x))C (A = Fe, Co, Ni, Mn, and combinations thereof, with x similar to 1/3) MAX phases synthesized by an alloy-guided reaction. The simultaneous occupancy of the 4 magnetic elements and Sn in the individual single-atom-thick A layers constitutes high-entropy MAX phase in which multielemental alloying exclusively occurs in the 2 -dimensional (2D) A layers. V-2(A(x)Sn(1-x))C exhibit distinct ferromagnetic behavior that can be compositionally tailored from the multielement A-layer alloying. Density functional theory and phase diagram calculations are performed to understand the structure stability of these MAX phases. This 2D multielemental alloying approach provides a structural design route to discover nanolaminated materials and expand their chemical and physical properties. In fact, the magnetic behavior of these multielemental MAX phases shows strong dependency on the combination of various elements.
25.	Li, Youbing, et al. (författare) Nanolaminated Ternary Transition Metal Carbide (MAX Phase)-Derived Core-Shell Structure Electrocatalysts for Hydrogen Evolution and Oxygen Evolution Reactions in Alkaline Electrolytes 2023 Ingår i: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 14:2, s. 481-488 Tidskriftsartikel (refereegranskat)abstract The development of abundant, cheap, and highly active catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is important for hydrogen production. Nanolaminate ternary transition metal carbides (MAX phases) and their derived two-dimensional transition metal carbides (MXenes) have attracted considerable interest for electrocatalyst applications. Herein, four new MAX@MXene core-shell structures (Ta2CoC@ Ta2CTx, Ta2NiC@Ta2CTx, Nb2CoC@Nb2CTx, and Nb2NiC@Nb2CTx), in which the core region is Co/Ni-MAX phases while the edge region is MXenes, have been prepared. Under alkaline electrolyte conditions, the Ta2CoC@Ta2CTx core-shell structure showed an overpotential of 239 mV and excellent stability during the HER with MXenes as the active sites. For the OER, the Ta2CoC@Ta2CTx core- shell structure showed an overpotential of 373 mV and a small Tafel plot (56 mV dec-1), which maintained a bulk crystalline structure and generated Co-based oxyhydroxides that formed by surface reconstruction as active sites. Considering rich chemical compositions and structures of MAX phases, this work provides a new strategy for designing multifunctional electrocatalysts and also paves the way for further development of MAX phase-based materials for clean energy applications.
26.	Li, Youbing, et al. (författare) Near-room temperature ferromagnetic behavior of single-atom-thick 2D iron in nanolaminated ternary MAX phases 2021 Ingår i: Applied Physics Reviews. - : AIP Publishing. - 1931-9401. ; 8:3 Tidskriftsartikel (refereegranskat)abstract M(n+)(1)AX(n) (MAX) phases nanolaminated ternary carbides or nitrides possess a unique crystal structure in which single-atom-thick "A" sublayers are interleaved by alternative stacking of a "Mn+1Xn" sublayer; these materials have been investigated as promising high-safety structural materials for industrial applications because of their laminated structure and metal and ceramic properties. However, limited of A-site elements in the definition of M(n+)(1)AX(n) phases, it is a huge challenge for designing nanolaminated ferromagnetic materials with single-atom-thick two-dimensional iron layers occupying the A layers in the M(n+)(1)AX(n) phases. Here, we report three new ternary magnetic M(n+)(1)AX(n) phases (Ta2FeC, Ti2FeN, and Nb2FeC) with A sublayers of single-atom-thick two-dimensional iron through an isomorphous replacement reaction of M(n+)(1)AX(n) precursors (Ta2AlC, Ti2AlN, and Nb2AlC) with a Lewis acid salts (FeCl2). All these M(n+)(1)AX(n) phases exhibit ferromagnetic behavior. The Curie temperatures of the Ta2FeC and Nb2FeC M(n+)(1)AX(n) phases are 281 and 291K, respectively, i.e., close to room temperature. The saturation magnetization of these ternary magnetic MAX phases is almost two orders of magnitude higher than V-2(Sn,Fe)C, whose A-site is partially substituted by Fe. Theoretical calculations on magnetic orderings of spin moments of Fe atoms in these nanolaminated magnetic M(n+)(1)AX(n) phases reveal that the magnetism can be mainly ascribed to an intralayer exchange interaction of the two-dimensional Fe atomic layers. Owing to the richness in composition of M(n+)(1)AX(n) phases, our work provides a large imaginary space for constructing functional single-atom-thick two-dimensional layers in materials using these nanolaminated templates.
27.	Li, Youbing, et al. (författare) Single-Atom-Thick Active Layers Realized in Nanolaminated Ti-3(AlxCu1-x)C-2 and Its Artificial Enzyme Behavior 2019 Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 13:8, s. 9198-9205 Tidskriftsartikel (refereegranskat)abstract A Ti-3(AlxCu1-x)C-2 phase with Cu atoms with a degree of ordering in the A plane is synthesized through the A site replacement reaction in CuCl2 molten salt. The weakly bonded single -atom -thick Cu layers in a Ti-3(AlxCu1-x)C-2 MAX phase provide actives sites for catalysis chemistry. As -synthesized Ti-3(AlxCu1-x)C-2 presents unusual peroxidase-like catalytic activity similar to that of natural enzymes. A fabricated Ti-3(AlxCu1-x)C-2/chitosan/glassy carbon electrode biosensor prototype also exhibits a low detection limit in the electrochemical sensing of H2O2. These results have broad implications for property tailoring in a nanolaminated MAX phase by replacing the A site with late transition elements.
28.	Lu, Jun, 1962-, et al. (författare) Tin+1Cn MXenes with fully saturated and thermally stable Cl terminations 2019 Ingår i: Nanoscale Advances. - : Royal Society of Chemistry. - 2516-0230. ; 1:9, s. 3680-3685 Tidskriftsartikel (refereegranskat)abstract MXenes are a rapidly growing family of 2D materials that exhibit a highly versatile structure and composition, allowing for significant tuning of the materials properties. These properties are, however, ultimately limited by the surface terminations, which are typically a mixture of species, including F and O that are inherent to the MXene processing. Other and robust terminations are lacking. Here, we apply high-resolution scanning transmission electron microscopy (STEM), corresponding image simulations and first-principles calculations to investigate the surface terminations on MXenes synthesized from MAX phases through Lewis acidic melts. The results show that atomic Cl terminates the synthesized MXenes, with mere residual presence of other termination species. Furthermore, in situ STEM-electron energy loss spectroscopy (EELS) heating experiments show that the Cl terminations are stable up to 750 degrees C. Thus, we present an attractive new termination that widely expands the MXenes functionalization space and enables new applications.
29.	Lundskog, Anders, et al. (författare) InGaN quantum dot formation mechanism on hexagonal GaN/InGaN/GaN pyramids 2012 Ingår i: Nanotechnology. - : Institute of Physics (IOP). - 0957-4484 .- 1361-6528. ; 23:30, s. 305708- Tidskriftsartikel (refereegranskat)abstract Growing InGaN quantum dots (QDs) at the apex of hexagonal GaN pyramids is an elegant approach to achieve a deterministic positioning of QDs. Despite similar synthesis procedures by metal–organic chemical vapor deposition, the optical properties of the QDs reported in the literature vary drastically. The QDs tend to exhibit either narrow or broad emission lines in the micro-photoluminescence spectra. By coupled microstructural and optical investigations, the QDs giving rise to narrow emission lines were concluded to nucleate in association with a (0001) facet at the apex of the GaN pyramid.
30.	Lundskog, Anders, et al. (författare) Unexpected behavior of InGaN quantum dot emission energy located at apices of hexagonal GaN pyramids Annan publikation (övrigt vetenskapligt/konstnärligt)abstract InGaN quantum dots (QDs) have been grown at the apices of hexagonal GaN pyramids. The pyramids were selectively grown on a (0001) oriented GaN template through circular apertures in a SiN mask positioned in square arrays. The emission of the InGaN QDs was shifted towards higher energies when the center-to-center distance of the pyramids was increased, while the emission from InGaN quantum wells located on the {1101} facets of the pyramids was energetically shifted towards lower energies. No energy shift was observed for (0001) truncated pyramids with truncation diameters larger than 100 nm.
31.	Mian, Li, et al. (författare) Synthesis of Novel MAX Phase Ti3ZnC2 via A-site-element-substitution Approach 2019 Ingår i: Journal of Inorganic Materials. - : SCIENCE PRESS. - 1000-324X. ; 34:1, s. 60-64 Tidskriftsartikel (refereegranskat)abstract Using Ti3AlC2 as the precursor, a new MAX phase Ti3ZnC2 was synthesized via an A-elemental substitution reaction in a molten salts bath. Composition and crystal structure of Ti3ZnC2 were confirmed by XRD, SEM and TEM analysis. Its structure stability and lattice parameter of Ti3ZnC2 were further proved by a theoretical calculation based on density function theory (DFT). Moreover, thermodynamics of A-elemental substitution reactions based on Fe, Co, Ni, and Cu were investigated. All results indicated that the similar substitution reactions are feasible to form series of MAX phases whose A sites are Fe, Co, Ni, and Cu elements. The substitution reaction was achieved by diffusion of Zn atoms into A-layers of Ti3AlC2, which requires Al-Zn eutectic formation at high temperatures. The molten salts provided a moderate environment for substitution reaction and accelerated reaction dynamics. The major advantage of this substitution reaction is that MAX phase keeps individual metal carbide layers intact, thus the formation of competitive phases, such as MA alloys, was avoided. The proposed A-elemental substitution reactions approach opens a new door to design and synthesize novel MAX phases which could not be synthesized by the traditional methods.
32.	Muhammad, Junaid, et al. (författare) Stress Evolution during Growth of GaN (0001)/Al2O3 (0001) by Reactive DC Magnetron Sputter Epitaxy 2014 Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 47:14, s. 145301- Tidskriftsartikel (refereegranskat)abstract We study the real time stress evolution, by in-situ curvature measurements, during magnetron sputter epitaxy of GaN (0001) epilayers at different growth temperatures, directly on Al2O3 (0001) substrates. The epilayers are grown by sputtering from a liquid Ga target in a mixed N2/Ar discharge. For 600 °C, a tensile biaxial stress evolution is observed, while for 700 °C and 800 °C, compressive stress evolutions are observed. Structural characterization by crosssectional transmission electron microscopy, and atomic force microscopy revealed that films grew at 700 °C and 800 °C in a layer-by-layer mode while a growth temperature of 600 °C led to an island growth mode. High resolution Xray diffraction data showed that edge and screw threading dislocation densities decreased with increasing growth temperature with a total density of 5.5×1010 cm-2. The observed stress evolution and growth modes are explained by a high adatom mobility during magnetron sputter epitaxy at 700 - 800 °C. Also other possible reasons for the different stress evolutions are discussed.
33.	Muhammad, Junaid, et al. (författare) Two-domain formation during the epitaxial growth of GaN (0001) on c-plane Al2O3 (0001) by high power impulse magnetron sputtering 2011 Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 110:12, s. 123519- Tidskriftsartikel (refereegranskat)abstract We study the effect of high power pulses in reactive magnetron sputter epitaxy on the structural properties of GaN (0001) thin films grown directly on Al2O3 (0001) substrates. The epilayers are grown by sputtering from a liquid Ga target, using a high power impulse magnetron sputtering power supply in a mixed N2/Ar discharge. X-ray diffraction, micro-Raman, micro-photoluminescence, and transmission electron microscopy investigations show the formation of two distinct types of domains. One almost fully relaxed domain exhibits superior structural and optical properties as evidenced by rocking curves with a full width at half maximum of 885 arc sec and a low temperature band edge luminescence at 3.47 eV with the full width at half maximum of 10 meV. The other domain exhibits a 14 times higher isotropic strain component, which is due to the higher densities of the point and extended defects, resulting from the ion bombardment during growth. Voids form at the domain boundaries. Mechanisms for the formation of differently strained domains, along with voids during the epitaxial growth of GaN are discussed.
34.	Nedfors, Nils, et al. (författare) Superhard NbB2-x thin films deposited by dc magnetron sputtering 2014 Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 257, s. 295-300 Tidskriftsartikel (refereegranskat)abstract We have deposited weakly textured substoichiometric NbB2-x thin films by magnetron sputtering from a NbB2 target. The films exhibit superhardness (42 ± 4 GPa), previously only observed in overstoichiometric TiB2 thin films, and explained by a self-organized nanostructuring, where thin TiB2 columnar grains hinder nucleation and slip of dislocations and a B-rich tissue phase between the grains prevent grain-boundary sliding. The wide homogeneity range for the NbB2 phase allows a similar ultra-thin B-rich tissue phase to form between thin (5 – 10 nm) columnar NbB2-x grains also for films with a B/Nb atomic ratio of 1.8, as revealed here by analytical aberration-corrected scanning transmission electron microscopy. Furthermore, a coefficient of friction of 0.16 is measured for a NbB2-x film sliding against stainless steel with a wear rate of 4x10-7 mm3/Nm. X-ray photoelectron spectroscopy results suggest that the low friction is due to the formation of a lubricating boric acid film.
35.	Tholander, Christopher, et al. (författare) Ab initio calculations and experimental study of piezoelectric YxIn1-xN thin films deposited using reactive magnetron sputter epitaxy 2016 Ingår i: Acta Materialia. - : Elsevier. - 1359-6454 .- 1873-2453. ; 105, s. 199-206 Tidskriftsartikel (refereegranskat)abstract By combining theoretical prediction and experimental verification we investigate the piezoelectric properties of yttrium indium nitride (YxIn1-xN). Ab initio calculations show that the YxIn1-xN wurtzite phase is lowest in energy among relevant alloy structures for 0≤x≤0.5. Reactive magnetron sputter epitaxy was used to prepare thin films with Y content up to x=0.51. The composition dependence of the lattice parameters observed in the grown films is in agreement with that predicted by the theoretical calculations confirming the possibility to synthesize a wurtzite solid solution. An AlN buffer layer greatly improves the crystalline quality and surface morphology of subsequently grown YxIn1-xN films. The piezoelectric response in films with x=0.09 and x=0.14 is observed using piezoresponse force microscopy. Theoretical calculations of the piezoelectric properties predict YxIn1âˆ’xN to have comparable piezoelectric properties to ScxAl1-xN.
36.	Wilhelmsson, O., et al. (författare) Deposition and characterization of ternary thin films within the Ti-Al-C system by DC magnetron sputtering 2006 Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 291:1, s. 290-300 Tidskriftsartikel (refereegranskat)abstract The formation of ternary compounds within the Ti-Al-C system was studied by magnetron sputtering for thin-film deposition and first-principles calculations for phase stability. As-deposited films were characterized with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM). The hardness and Young's moduli of the material were studied by nanoindentation. Epitaxial and phase-pure films of Mn+1AXn phases Ti3AlC2 and Ti2AlC as well as the perovskite phase Ti3AlC were deposited on Al2O3(00l) wafers kept at temperatures between 800 and 900 °C. The only ternary phases observed at low temperatures (300 °C) were Ti3AlC and cubic (Ti,Al)C, the latter can be described as a metastable solid solution of Al in TiC similar to the more studied (Ti,Al)N system. The difficulties to form MAX phases at low substrate temperatures were attributed of requirement for a sufficient diffusivity to partition the elements corresponding to the relatively complex crystal structures with long c-axes. While MAX-phase synthesis at 800 °C is significantly lower than contemporary bulk sintering processes, a reduction of the substrate temperature towards 300 °C in the present thin-film deposition experiments resulted in stacking sequence variations and the intergrowth of (Ti,Al)C. © 2006 Elsevier B.V. All rights reserved.
37.	Abom, A.E., et al. (författare) Influence of gate metal film growth parameters on the properties of gas sensitive field-effect devices 2002 Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 409:2, s. 233-242 Tidskriftsartikel (refereegranskat)abstract Thin films of Pt have been grown as gate metals on the oxide surface of gas sensitive field-effect devices. Both electron beam evaporation and dc magnetron sputtering has been used. The energy of the impinging Pt atoms, the substrate temperature and the thickness of the Pt film were used as parameters in this study. The influence of the growth parameters on the gas response has been investigated and compared with the properties of the films, studied by transmission electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The conditions during growth of the Pt film are found to have a large impact on the properties of the device. As expected, crystallinity, morphology and the metal/substrate interfacial structure are also affected by processing parameters. Three different growth processes stand out as the most promising from gas sensor considerations, namely room temperature evaporation, sputtering at high pressures and sputtering at high temperatures. The correlation between gas responses and properties of the gas sensitive layer is discussed. © 2002 Elsevier Science B.V. All rights reserved.
38.	Aili, Carola, 1963-, et al. (författare) Research on teachers' professional lives : time to build a research network. Paper presented at NERA's 31st Congress, 6-9 March, Copenhagen 2003 Konferensbidrag (refereegranskat)abstract Teachers’ work has during the last ten years gone through great changes. The effects of postmodern society has made the work more and morecomplex and difficult to handle and understand for those involved as well as outsiders. Researchers are trying to keep up with things. The developmentof knowledge of teachers’ work takes place on different levels, in separate disciplines, from various starting-points and with different foci.To be able to describe, understand and explain the »new« work of teachers in a vigorous way there is need of getting these research initiativestogether. Arenas should be established where interchanges and coordination between researchers could take place. In order to make this happen wehave the intention of building a Swedish (our aim is to expand the network to the Nordic countries after the establishment in Sweden) network ofresearch on teachers’ professional lives.Besides presenting the intention and design of our network we also bring along some examples of research projects in line with the network ideas.
39.	Aili, Carola, et al. (författare) Research on teachers' professional lives : time to build a research network. Paper presented at NERA's 31st Congress, 6-9 March, Copenhagen 2003 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Teachers’ work has during the last ten years gone through great changes. The effects of postmodern society has made the work more and morecomplex and difficult to handle and understand for those involved as well as outsiders. Researchers are trying to keep up with things. The developmentof knowledge of teachers’ work takes place on different levels, in separate disciplines, from various starting-points and with different foci.To be able to describe, understand and explain the »new« work of teachers in a vigorous way there is need of getting these research initiativestogether. Arenas should be established where interchanges and coordination between researchers could take place. In order to make this happen wehave the intention of building a Swedish (our aim is to expand the network to the Nordic countries after the establishment in Sweden) network ofresearch on teachers’ professional lives.Besides presenting the intention and design of our network we also bring along some examples of research projects in line with the network ideas.
40.	Alami, Jones, et al. (författare) High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target 2006 Ingår i: Thin Solid Films. - : Institutionen för fysik, kemi och biologi. - 0040-6090 .- 1879-2731. ; 515:4, s. 1731-1736 Tidskriftsartikel (refereegranskat)abstract We have deposited Ti-Si-C thin films using high-power impulse magnetron sputtering (HIPIMS) from a Ti3SiC2 compound target. The as-deposited films were composite materials with TiC as the main crystalline constituent. X-ray diffraction and photoelectron spectroscopy indicated that they also contained amorphous SiC, and for films deposited on inclined substrates, crystalline Ti5Si3Cx. The film morphology was dense and flat, while films deposited with dc magnetron sputtering under comparable conditions were rough and porous. Due to the high degree of ionization of the sputtered species obtained in HIPIMS, it is possible to control the film composition, in particular the C content, by tuning the substrate inclination angle, the Ar process pressure, and the bias voltage.
41.	Alkaissi, Hammoudi, et al. (författare) Bank1 and NF-kappaB as key regulators in anti-nucleolar antibody development 2018 Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 13:7 Tidskriftsartikel (refereegranskat)abstract Systemic autoimmune rheumatic disorders (SARD) represent important causes of morbidity and mortality in humans. The mechanisms triggering autoimmune responses are complex and involve a network of genetic factors. Mercury-induced autoimmunity (HgIA) in mice is an established model to study the mechanisms of the development of antinuclear antibodies (ANA), which is a hallmark in the diagnosis of SARD. A.SW mice with HgIA show a significantly higher titer of antinucleolar antibodies (ANoA) than the B10.S mice, although both share the same MHC class II (H-2). We applied a genome-wide association study (GWAS) to their Hg-exposed F2 offspring to investigate the non-MHC genes involved in the development of ANoA. Quantitative trait locus (QTL) analysis showed a peak logarithm of odds ratio (LOD) score of 3.05 on chromosome 3. Microsatellites were used for haplotyping, and fine mapping was conducted with next generation sequencing. The candidate genes Bank1 (B-cell scaffold protein with ankyrin repeats 1) and Nfkbl (nuclear factor kappa B subunit 1) were identified by additional QTL analysis. Expression of the Bank1 and Nfkb1 genes and their downstream target genes involved in the intracellular pathway (Tlr9,II6, Tnf) was investigated in mercury-exposed A.SW and B10.S mice by real-time PCR. Bank1 showed significantly lower gene expression in the A.SW strain after Hg-exposure, whereas the B10.S strain showed no significant difference. Nfkb1, Tlr9, II6 and Tnf had significantly higher gene expression in the A.SW strain after Hg-exposure, while the B10.S strain showed no difference. This study supports the roles of Bank1 (produced mainly in B-cells) and Nfkbl (produced in most immune cells) as key regulators of ANoA development in HgIA.
42.	Alkaissi, Hammoudi, et al. (författare) Genome-Wide Association Study to Identify Genes Related to Renal Mercury Concentrations in Mice 2016 Ingår i: Journal of Environmental Health Perspectives. - : U.S. Department of Health and Human Services * National Institute of Environmental Health Sciences. - 0091-6765 .- 1552-9924. ; 124:7, s. 920-926 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Following human mercury (Hg) exposure, the metal accumulates in considerable concentrations in kidney, liver, and brain. Although the toxicokinetics of Hg have been studied extensively, factors responsible for interindividual variation in humans are largely unknown. Differences in accumulation of renal Hg between inbred mouse strains suggest a genetic interstrain variation regulating retention or/and excretion of Hg. A. SW, DBA/2 and BALB/C mouse strains accumulate higher amounts of Hg than B10.S.OBJECTIVES: We aimed to find candidate genes associated with regulation of renal Hg concentrations.METHODS: A. SW, B10.S and their F1 and F2 offspring were exposed for 6 weeks to 2.0 mg Hg/L drinking water. Genotyping with microsatellites was conducted on 84 F2 mice for genome-wide scanning with ion pair reverse-phase high-performance liquid chromatography (IP RP HPLC). Quantitative trait loci (QTL) were established. Denaturing HPLC was used to detect single nucleotide polymorphisms for haplotyping and fine mapping in 184 and 32 F2 mice, respectively. Candidate genes (Pprc1, Btrc and Nfkb2) verified by fine mapping and QTL were further investigated by real-time polymerase chain reaction. Genes enhanced by Pprc1 (Nrf1 and Nrf2) were included for gene expression analysis.RESULTS: Renal Hg concentrations differed significantly between A. SW and B10. S mice and between males and females within each strain. QTL analysis showed a peak logarithm of odds ratio score 5.78 on chromosome 19 (p = 0.002). Haplotype and fine mapping associated the Hg accumulation with Pprc1, which encodes PGC-1-related coactivator (PRC), a coactivator for proteins involved in detoxification. Pprc1 and two genes coactivated by Pprc1 (Nrf1 and Nrf2) had significantly lower gene expression in the A. SW strain than in the B10. S strain.CONCLUSIONS: This study supports Pprc1 as a key regulator for renal Hg excretion.
43.	Alkaissi, Hammoudi, 1983- (författare) Identification of candidate genes involved in Mercury Toxicokinetics and Mercury Induced Autoimmunity 2018 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract BACKGROUND: Autoimmune diseases require the involvement and activation of immune cells and occur when the body builds up an immune response against its own tissues. This process takes place due to the inability to distinguish self-antigen from foreign antigen. Systemic autoimmunity represents an important cause of morbidity and mortality in humans. The mechanisms triggering autoimmune responses are complex and involve a network of genetic factors. Genome wide association study (GWAS) is a powerful method, used to identify genetic risk factors in numerous diseases, such as systemic autoimmune diseases. The goal of GWAS is to identify these genetic risk factors in order to make predictions about who is at risk and investigate the biological process of disease susceptibility. There are several valuable mouse models to investigate the underlying mechanisms causing systemic autoimmune diseases in which mercury induced autoimmunity (HgIA) is a well- established and relevant model. HgIA in mice includes development of autoantibodies, immune complex glomerulonephritis, lymphocyte proliferation, hypergammaglobulinemia and polyclonal B cell activation. In humans, mercury exposure accumulates with considerable concentrations in kidney, liver, and brain. Toxicokinetics of Hg has been studied extensively but the key for inter-individual variation in humans are largely unclear. Differences in accumulation of renal Hg between inbred mouse strains suggest a genetic inter-strain variation regulating retention or/and excretion of Hg.OBJECTIVES: To find loci and candidate genes associated with phenotypes involved in the development of autoimmunity and find candidate genes involved in the regulation of renal Hg excretion.METHODS: MHC II (H-2s) mice were paired (A.SW x B10.S) to obtain F2 offspring exposed to 2.0 or 4.0 mg Hg in drinking water for 6 weeks. Mercury induced autoimmune phenotypes were studied with immunofluorescence (anti-nucleolar antibodies (ANoA)), ELISA anti-DNP/anti-ssDNA (polyclonal B cell activation), anti-chromatin antibodies (ACA) (4.0 mg Hg), and serum IgG1 concentrations. Mercury accumulation in kidney was performed previously and data was included as phenotype. F2 mice exposed to 2.0 mg Hg were genotyped with microsatellites for genome-wide scan with Ion Pair Reverse Phase High Performance Liquid Chromatography (IP RP HPLC). F2 mice exposed to 4.0 mg Hg were genotyped with single nucleotide polymorphisms for genomewide scan with SNP&SEQ technology platform. Quantitative trait loci (QTL) was established with R/QTL. Denaturing HPLC, next generation sequencing, conserved region analysis and genetic mouse strain comparison were used for haplotyping and fine mapping on QTLs associated with Hg concentration in kidney, development of ANoA and serum IgG1 hypergammaglobulinemia. Candidate genes (Pprc1, Bank1 and Nfkb1) verified by additional QTL were further investigated by real time polymerase chain reaction. Genes involved in the intracellular signaling together with candidate genes were included for gene expression analysis.RESULTS: F2 mice exposed to 2.0 mg Hg had low or no development of autoantibodies and showed no significant difference in polyclonal B cell activation in the B10.S and F2 strains. F2 mice exposed to 4.0 mg Hg developed autoantibodies and significantly increased IgG1 concentration and polyclonal B cell activation (anti-DNP). QTL analysis showed a logarithm of odds ratio (LOD) score between 2.9 – 4.36 on all serological phenotypes exposed to 4.0 mg Hg, and a LOD score of 5.78 on renal Hg concentration. Haplotyping and fine mapping associated the development of ANoA with Bank1 (B-cell scaffold protein with ankyrin repeats 1) and Nfkb1 (nuclear factor kappa B subunit 1). The serum IgG1 concentration was associated with a locus on chromosome 3, in which Rxfp4 (Relaxin Family Peptide/INSL5 Receptor 4) is a potential candidate gene. The renal Hg concentration was associated with Pprc1 (Peroxisome Proliferator-Activated Receptor Gamma, Co-activator-Related). Gene expression analysis revealed that the more susceptible A.SW strain expresses significantly higher levels of Nfkb1, Il6 and Tnf than the less susceptible B10.S strain. The A.SW strain expresses significantly lower levels of Pprc1 and cascade proteins than the B10.S strain. Development of ACA was associated with chromosomes 3, 6, 7 and 16 (LOD 3.1, 3.2, 3.4 and 6.8 respectively). Polyclonal B cell activation was associated with chromosome 2 with a LOD score of 2.9.CONCLUSIONS: By implementing a GWAS on HgIA in mice, several QTLs were discovered to be associated with the development of autoantibodies, polyclonal B cell activation and hypergammaglobulinemia. This thesis plausibly supports Bank1 and Nfkb1 as key regulators for ANoA development and HgIA seems to be initiated by B cells rather than T cells. GWAS on renal mercury excretion plausibly supports Pprc1 as key regulator and it seems that this gene has a protective role against Hg.
44.	Alling, Björn, et al. (författare) Theoretical investigation of cubic B1-like and corundum (Cr1−xAlx)2O3 solid solutions Annan publikation (övrigt vetenskapligt/konstnärligt)abstract First-principles calculations are employed to investigate the stability and properties of cubic rock-salt like (Cr1−xAlx)2O3 solid solutions, stabilized by metal site vacancies as recently reported experimentally. It is demonstrated that the metal site vacancies can indeed be ordered in a way that gives rise to a favorable coordination of all O atoms in the lattice. B1-like structures with ordered and disordered metal site vacancies are studied for (Cr0.5Al0.5)2O3 and found to a have cubic lattice spacing close to the values reported experimentally, in contrast to fluorite-like and perovskite structures. The obtained B1-like structures are higher in energy than corundum solid solutions for all compositions, but with an energy offset per atom similar to other metastable systems possible to synthesize with physical vapor deposition techniques. The obtained electronic structures show that the B1-like systems are semiconducting although with smaller band gaps than the corundum structure.
45.	Alling, Björn, et al. (författare) Theoretical investigation of cubic B1-like and corundum (Cr1−xAlx)2O3 solid solutions 2013 Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 31:3 Tidskriftsartikel (refereegranskat)abstract First-principles calculations are employed to investigate the stability and properties of cubic rock-salt-like (Cr1−xAlx)2O3 solid solutions, stabilized by metal site vacancies as recently reported experimentally. It is demonstrated that the metal site vacancies can indeed be ordered in a way that gives rise to a suitable fourfold coordination of all O atoms in the lattice. B1-like structures with ordered and disordered metal site vacancies are studied for (Cr0.5Al0.5)2O3 and found to have a cubic lattice spacing close to the values reported experimentally, in contrast to fluorite-like and perovskite structures. The obtained B1-like structures are higher in energy than corundum solid solutions for all compositions, but with an energy offset per atom similar to other metastable systems possible to synthesize with physical vapor deposition techniques. The obtained electronic structures show that the B1-like systems are semiconducting although with smaller band gaps than the corundum structure.
46.	Almroth, Gabriel, 1953-, et al. (författare) Acute glomerulonephritis associated with streptococcus pyogenes with concomitant spread of streptococcus constellatus in four rural families 2005 Ingår i: Upsala Journal of Medical Sciences. - 0300-9734 .- 2000-1967. ; 110:3, s. 217-231 Tidskriftsartikel (refereegranskat)abstract We studied history, renal histopathology and microbiology of an epidemic of acute glomerulonephritis associated with throat infections and uncommon culture results in four neighbour families. A 40-year-old man (index patient) was referred to a university hospital for dialysis and kidney biopsy due to a suspected acute glomerulonephritis. An acute tonsillitis had preceded the condition. Penicillin treatment had been started four days before the discovery of renal failure. Throat swabs were positive for β-hemolytic streptococci, group C (GCS). GCS were also found in throat cultures from his wife and two of their children. The bacteria were typed as Streptococcus constellatus. A third child had S. constellatus expressing Lancefield antigen group G. A neighbour and two of his children fell ill the following week with renal involvement. Throat swabs from both these children were positive for S. constellatus. His third child had erythema multiforme and S. constellatus in the throat while a fourth child had β-hemolytic streptococci group A, Streptococcus pyogenes. Kidney biopsies on the index patient and his neighbour showed an acute diffuse prolipherative glomerulonephritis compatible with acute post-streptococcal nephritis and microbiological analysis of renal tissue revealed in both cases S. pyogenes and S. constellatus. The families had had much contact and had consumed unpasteurized milk from our index patient's farm. In four of seven persons in two additional neighbouring families S. constellatus was found in throat swabs during the same month while two persons carried Streptococcus anginosus expressing the Lancefield C antigen. In conclusion spread of S. constellatus coincided with the occurrence of four cases of acute glomerulonephritis. The two biopsied patients had both S. pyogenes and S. constellatus present in renal tissue. The epidemic either suggested that the outbreak of glomerulonephritis was due to S. pyogenes but coincided with the transmission and colonization of S. constellatus or that the S. constellatus strains were highly pathogenic or nephritogenic and that this organism can be transmitted in such cases.
47.	Alnoor, Hatim, et al. (författare) Exploring MXenes and their MAX phase precursors by electron microscopy 2021 Ingår i: Materials Today Advances. - : Elsevier. - 2590-0498. ; 9 Tidskriftsartikel (refereegranskat)abstract This review celebrates the width and depth of electron microscopy methods and how these have enabled massive research efforts on MXenes. MXenes constitute a powerful recent addition to 2-dimensional materials, derived from their parent family of nanolaminated materials known as MAX phases. Owing to their rich chemistry, MXenes exhibit properties that have revolutionized ranges of applications, including energy storage, electromagnetic interference shielding, water filtering, sensors, and catalysis. Few other methods have been more essential in MXene research and development of corresponding applications, compared with electron microscopy, which enables structural and chemical identification at the atomic scale. In the following, the electron microscopy methods that have been applied to MXene and MAX phase precursor research are presented together with research examples and are discussed with respect to advantages and challenges.
48.	Amirhosseini, Mehdi, et al. (författare) Autoantibodies in outbred Swiss Webster mice following exposure to gold and mercury 2021 Ingår i: Toxicology and Applied Pharmacology. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0041-008X .- 1096-0333. ; 412 Tidskriftsartikel (refereegranskat)abstract Exposure to heavy metals may have toxic effects on several human organs causing morbidity and mortality. Metals may trigger or exacerbate autoimmunity in humans. Inbred mouse strains with certain H-2 haplotypes are susceptible to xenobiotic-induced autoimmunity; and their immune response to metals such as mercury, gold, and silver have been explored. Serum antinuclear antibodies (ANA), polyclonal B-cell activation, hypergammaglobulinemia and tissue immune complex deposition are the main features of metal-induced autoimmunity in inbred mice. However, inbred mouse strains do not represent the genetic heterogeneity in humans. In this study, outbred Swiss Webster (SW) mice exposed to gold or mercury salts showed immune and autoimmune responses. Intramuscular injection of 22.5 mg/kg.bw aurothiomalate (AuTM) induced IgG ANA in SW mice starting after 5 weeks that persisted until week 15 although with a lower intensity. This was accompanied by elevated serum levels of total IgG antibodies against chromatin and total histones. Exposure to gold led to development of serum IgG autoantibodies corresponding to H1 and H2A histones, and dsDNA. Both gold and mercury induced polyclonal B-cell activation. Eight mg/L mercuric chloride (HgCl2) in drinking water, caused IgG antinucleolar antibodies (ANoA) after 5 weeks in SW mice accompanied by immune complex deposition in kidneys and spleen. Serum IgG antibodies corresponding to anti-fibrillarin, and anti-PM/Scl-100 antibodies, were observed in mercury-exposed SW mice. Gold and mercury trigger systemic autoimmune response in genetically heterogeneous outbred SW mice and suggest them as an appropriate model to study xenobiotic-induced autoimmunity.
49.	Anasori, Babak, et al. (författare) Experimental and theoretical characterization of ordered MAX phases Mo2TiAlC2 and Mo2Ti2AlC3 2015 Ingår i: Journal of Applied Physics. - : AMER INST PHYSICS. - 0021-8979 .- 1089-7550. ; 118:9, s. 094304- Tidskriftsartikel (refereegranskat)abstract Herein, we report on the phase stabilities and crystal structures of two newly discovered ordered, quaternary MAX phases-Mo2TiAlC2 and Mo2Ti2AlC3-synthesized by mixing and heating different elemental powder mixtures of mMo:(3-m) Ti:1.1Al:2C with 1.5 less than= m less than= 2.2 and 2Mo: 2Ti:1.1Al:2.7C to 1600 degrees C for 4 h under Ar flow. In general, for m greater than= 2 an ordered 312 phase, (Mo2Ti) AlC2, was the majority phase; for mless than 2, an ordered 413 phase (Mo2Ti2)AlC3, was the major product. The actual chemistries determined from X-ray photoelectron spectroscopy (XPS) are Mo2TiAlC1.7 and Mo2Ti1.9Al0.9C2.5, respectively. High resolution scanning transmission microscopy, XPS and Rietveld analysis of powder X-ray diffraction confirmed the general ordered stacking sequence to be Mo-Ti-Mo-Al-Mo-Ti-Mo for Mo2TiAlC2 and Mo-Ti-Ti-Mo-Al-Mo-Ti-Ti-Mo for Mo2Ti2AlC3, with the carbon atoms occupying the octahedral sites between the transition metal layers. Consistent with the experimental results, the theoretical calculations clearly show that M layer ordering is mostly driven by the high penalty paid in energy by having the Mo atoms surrounded by C in a face-centered configuration, i.e., in the center of the Mn+1Xn blocks. At 331 GPa and 367 GPa, respectively, the Youngs moduli of the ordered Mo2TiAlC2 and Mo2Ti2AlC3 are predicted to be higher than those calculated for their ternary end members. Like most other MAX phases, because of the high density of states at the Fermi level, the resistivity measurement over 300 to 10K for both phases showed metallic behavior. (C) 2015 AIP Publishing LLC.
50.	Anshelm, Jonas, 1960-, et al. (författare) Samhället, tekniken och säkerheten - En förstudie 2006 Annan publikation (populärvet., debatt m.m.)

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