| 1. |
- Kuzmenko, Volodymyr, 1987, et al.
(författare)
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Cellulose-derived carbon nanofibers/graphene composite electrodes for powerful compact supercapacitors
- 2017
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 7:73, s. 45968-45977
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we demonstrate a unique supercapacitor composite electrode material that is originated from a sustainable cellulosic precursor via simultaneous one-step carbonization/reduction of cellulose/graphene oxide mats at 800 degrees C. The resulting freestanding material consists of mechanically stable carbon nanofibrous (CNF, fiber diameter 50-500 nm) scaffolds tightly intertwined with highly conductive reduced graphene oxide (rGO) sheets with a thickness of 1-3 nm. The material is mesoporous and has electrical conductivity of 49 S cm(-1), attributed to the well-interconnected graphene layers. The electrochemical evaluation of the CNF/graphene composite electrodes in a supercapacitor device shows very promising volumetric values of capacitance, energy and power density (up to 46 F cm(-3), 1.46 W h L-1 and 1.09 kW L-1, respectively). Moreover, the composite electrodes retain an impressive 97% of the initial capacitance over 4000 cycles. With these superior properties, the produced composite electrodes should be the "looked-for" components in compact supercapacitors used for increasingly popular portable electronics and hybrid vehicles.
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| 2. |
- Adman, Per, et al.
(författare)
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171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
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Ingår i: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 3. |
- Karlsson, Johan, 1984, et al.
(författare)
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The effect of alendronate on biomineralization at the bone/implant interface
- 2016
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 104:3, s. 620-629
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Tidskriftsartikel (refereegranskat)abstract
- A recent approach to improve the osseointegration of implants is to utilize local drug administration. The presence of an osteoporosis drug may influence both bone quantity and quality at the bone/implant interface. Despite this, the performance of bone-anchoring implants is traditionally evaluated only by quantitative measurements. In the present study, the osteoporosis drug alendronate (ALN) was administrated from mesoporous titania thin films that were coated onto titanium implants. The effect that the drug had on biomineralization was explored both in vitro using simulated body fluid (SBF) and in vivo in a rat tibia model. The SBF study showed that the apatite formation was completely hindered at a high concentration of ALN (0.1 mg/mL). However, when ALN was administrated from the mesoporous coating the surface became completely covered with apatite. Ex vivo characterization of the bone/implant interface using Raman spectroscopy demonstrated that the presence of ALN enhanced the bone mineralization, and that the chemical signature of newly formed bone in the presence of ALN had a higher resemblance to the pre-existing mature bone than to the bone formed without drug. Taken together, this study demonstrates the importance of evaluating the quality of the formed bone to better understand the performance of implants.
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| 4. |
- Atefyekta, Saba, 1987, et al.
(författare)
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Antimicrobial performance of mesoporous titania thin films: role of pore size, hydrophobicity, and antibiotic release
- 2016
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Ingår i: International journal of nanomedicine. - : Informa UK Limited. - 1176-9114 .- 1178-2013. ; 11, s. 977-990
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Tidskriftsartikel (refereegranskat)abstract
- Implant-associated infections are undesirable complications that might arise after implant surgery. If the infection is not prevented, it can lead to tremendous cost, trauma, and even life threatening conditions for the patient. Development of an implant coating loaded with antimicrobial substances would be an effective way to improve the success rate of implants. In this study, the in vitro efficacy of mesoporous titania thin films used as a novel antimicrobial release coating was evaluated. Mesoporous titania thin films with pore diameters of 4, 6, and 7 nm were synthesized using the evaporation-induced self-assembly method. The films were characterized and loaded with antimicrobial agents, including vancomycin, gentamicin, and daptomycin. Staphylococcus aureus and Pseudomonas aeruginosa were used to evaluate their effectiveness toward inhibiting bacterial colonization. Drug loading and delivery were studied using a quartz crystal microbalance with dissipation monitoring, which showed successful loading and release of the antibiotics from the surfaces. Results from counting bacterial colony-forming units showed reduced bacterial adhesion on the drug-loaded films. Interestingly, the presence of the pores alone had a desired effect on bacterial colonization, which can be attributed to the documented nanotopographical effect. In summary, this study provides significant promise for the use of mesoporous titania thin films for reducing implant infections.
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| 5. |
- Ayatolahi, Fatemeh, 1984, et al.
(författare)
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Sources of Variation in Error Sensitivity Measurements, Significant or Not?
- 2018
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Ingår i: Proceedings - 48th Annual IEEE/IFIP International Conference on Dependable Systems and Networks Workshops, DSN-W 2018. - 9781538665534 ; , s. 71-72
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Konferensbidrag (refereegranskat)abstract
- Measuring the error sensitivity by fault injection is an important method for assessing the dependability of computer systems. In this paper, we define error sensitivity as the conditional probability that a hardware-related error causes a silent data corruption. When measuring the error sensitivity it is important to consider how the experimental setup and the workload characteristics affect the estimated error sensitivity. We consider five such potential sources of variation (PSVs) in this paper. Three of these are related to the workload: i) input profile, ii) source code implementation, and, iii) use of compiler optimization. Two are related to the experimental setup: i) single vs. double bit-flips, and ii) inject-on-read vs. inject-on-write. The paper discusses the applicability of different statistical tests for assessing whether a PSV has a significant impact on error sensitivity.
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| 6. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Strategies to improve usability and preserve accuracy in biological sequence databases
- 2016
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Ingår i: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861. ; 16:18, s. 2454-2460
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Tidskriftsartikel (refereegranskat)abstract
- Biology is increasingly dependent on large-scale analysis, such as proteomics, creating a requirement for efficient bioinformatics. Bioinformatic predictions of biological functions rely upon correctly annotated database sequences, and the presence of inaccurately annotated or otherwise poorly described sequences introduces noise and bias to biological analyses. Accurate annotations are, for example, pivotal for correct identifications of polypeptide fragments. However, standards for how sequence databases are organized and presented are currently insufficient. Here, we propose five strategies to address fundamental issues in the annotation of sequence databases: (i) to clearly separate experimentally verified and unverified sequence entries; (ii) to enable a system for tracing the origins of annotations; (iii) to separate entries with high-quality, informative annotation from less useful ones; (iv) to integrate automated quality-control software whenever such tools exist; and (v) to facilitate post-submission editing of annotations and metadata associated with sequences. We believe that implementation of these strategies, for example as requirements for publication of database papers, would enable biology to better take advantage of large-scale data.
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| 7. |
- Cecchinato, Francesca, et al.
(författare)
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Osteogenic potential of human adipose-derived stromal cells on 3-dimensional mesoporous TiO2 coating with magnesium impregnation
- 2015
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Ingår i: Materials Science and Engineering C. - : Elsevier BV. - 0928-4931 .- 1873-0191. ; 52, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the osteogenic response of human adipose-derived stromal cells (ADScs) to mesoporous titania (TiO2) coatings produced with evaporation-induced self-assembly method (EISA) and loaded with magnesium. Our emphasis with the magnesium release functionality was to modulate progenitor cell osteogenic differentiation under standard culture conditions. Osteogenic properties of the coatings were assessed for stromal cells by means of scanning electron microscopy (SEM) imaging, colorimetric mitochondrial viability assay (MTT), colorimetric alkaline phosphates activity (ALP) assay and real time RT-polymerase chain reaction (PCR). Using atomic force microscopy (AFM) it was shown that the surface expansion area (S-dr) was strongly enhanced by the presence of magnesium. From MTT results it was shown that ADSc viability was significantly increased on mesoporous surfaces compared to the non-porous one at a longer cell culture time. However, no differences were observed between the magnesium impregnated and non-impregnated surfaces. The alkaline phosphatase activity confirmed that ADSc started to differentiate into the osteogenic phenotype after 2 weeks of culturing. The gene expression profile at 2 weeks of cell growth showed that such coatings were capable to incorporate specific osteogenic markers inside their interconnected nano-pores and, at 3 weeks, ADSc differentiated into osteoblasts. Interestingly, magnesium significantly promoted the osteopontin gene expression, which is an essential gene for the early biomaterial-cell osteogenic interaction. (C) 2015 Elsevier B.V. All rights reserved.
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| 8. |
- Folkesson, Peter, 1968, et al.
(författare)
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Back-to-Back Fault Injection Testing in Model-Based Development
- 2015
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. - 9783319242545 - 9783319242552 ; 9337, s. 135-148
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Konferensbidrag (refereegranskat)abstract
- Today, embedded systems across industrial domains (e.g., avionics, automotive) are representatives of software-intensive systems with increasing reliance on software and growing complexity. It has become critically important to verify software in a time, resource and cost effective manner. Furthermore, industrial domains are striving to comply with the requirements of relevant safety standards. This paper proposes a novel workflow along with tool support to evaluate robustness of software in model-based development environment, assuming different abstraction levels of representing software. We then show the effectiveness of our technique, on a brake-by-wire application, by performing back-to-back fault injection testing between two different abstraction levels using MODIFI for the Simulink model and GOOFI-2 for the generated code running on the target microcontroller. Our proposed method and tool support facilitates not only verifying software during early phases of the development lifecycle but also fulfilling back-to-back testing requirements of ISO 26262 when using model-based development.
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| 9. |
- Galli, Silvia, et al.
(författare)
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Magnesium release from mesoporous carriers on endosseus implants does not influence bone maturation at 6 weeks in rabbit bone
- 2017
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Ingår i: Journal of Biomedical Materials Research - Part B Applied Biomaterials. - : Wiley. - 1552-4981 .- 1552-4973. ; 105:7, s. 2118-2125
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesThe release of magnesium ions (Mg2+) from titanium surfaces has been shown to boost the initial biological response of peri-implant bone and to increase the biomechanical strength of osseointegration. The objective of the present paper was to investigate if the initial improvement in osseointegration would influence the bone remodeling also during the maturation stage of bone healing. Methods: Titanium implants were coated with mesoporous titania layers and either loaded with Mg2+ (test group) or left untreated (control group). The implants were inserted in the tibiae of 10 New Zealand White rabbits. Osseointegration was assessed after 6 weeks by means of biomechanical testing (RTQ), non-decalcified histology and histomorphometry (BIC%, BA%, NBA%). The expression of genes involved in the bone formation and remodeling was quantified using qPCR. Results: Mg2+ releasing mesoporous titania coatings showed, on average, higher removal torques and histomorphometrical outcomes (RTQ: 17.2 Ncm vs. 15 Ncm; BIC: 38.8% vs. 32.1%; BA%: 71.6% vs. 64%; NBA% 62.5% vs. 54% for the tests vs the controls); however, the differences were not statistically significant. Three osteogenic markers, osteocalcin (OC), collagen 1 alpha 1 (COL1A1), and alkalin phosphatase (ALPL), were respectively 2-fold, 1.53-fold, and 1.13-fold up-regulated in the control group compared to the test. The expression of COL1A1 was particularly high in both groups, while the biomarkers for remodeling and inflammation showed a low expression in both groups. Significance: The results suggested that the initial enhancement in osseointegration induced by magnesium release from mesoporous titania coatings has no detrimental effects during bone maturation.
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| 10. |
- Galli, Silvia, et al.
(författare)
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Osteoconductive potential of mesoporous titania implant surfaces loaded with magnesium : an experimental study in the rabbit
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 17:6, s. 1048-1059
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mesoporous coatings enable incorporation of functional substances and sustainedly release them at the implant site. One bioactive substance that can be incorporated in mesoporous is magnesium, which is strongly involved in bone metabolism and in osteoblast interaction. Purpose: The aim of this experimental study was to evaluate the effect of incorporation of magnesium into mesoporous coatings of oral implants on early stages of osseointegration. Material and Methods: Titanium implants were coated with thin films of mesoporous TiO2 having pore diameters of 6 nm and were loaded with magnesium. The implant surfaces were extensively characterized by means of interferometry, atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy and then placed in the tibiae of 10 rabbits. After 3 weeks of healing, osseointegration was evaluated by means of removal torque testing and histology and histomorphometry. Results: Histological and biomechanical analyses revealed no side effects and successful osseointegration of the implants. The biomechanical evaluation evidenced a significant effect of magnesium doping on strengthening the implant-bone interface. Conclusions: A local release of magnesium from the implant surfaces enhances implant retention at the early stage of healing (3 weeks after implantation), which is highly desirable for early loading of the implant.
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