| 11. |
- Crispin, Xavier, 1972-, et al.
(författare)
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Photochromic Diodes
- 2006. - 2
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Ingår i: Semiconducting Polymers. - Weinheim, Tyskland : WileyVCH Verlag GmbH & Co. - 9783527312719 - 3527312714 ; , s. 579-611
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The field of semiconducting polymers has attracted many researchers from a diversity of disciplines. Printed circuitry, flexible electronics and displays are already migrating from laboratory successes to commercial applications, but even now fundamental knowledge is deficient concerning some of the basic phenomena that so markedly influence a device's usefulness and competitiveness. This two-volume handbook describes the various approaches to doped and undoped semiconducting polymers taken with the aim to provide vital understanding of how to control the properties of these fascinating organic materials. Prominent researchers from the fields of synthetic chemistry, physical chemistry, engineering, computational chemistry, theoretical physics, and applied physics cover all aspects from compounds to devices.Since the first edition was published in 2000, significant findings and successes have been achieved in the field, and especially handheld electronic gadgets have become billion-dollar markets that promise a fertile application ground for flexible, lighter and disposable alternatives to classic silicon circuitry. The second edition brings readers up-to-date on cutting edge research in this field.
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| 12. |
- Dibattista, Joseph D., et al.
(författare)
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A genetic assessment of polyandry and breeding-site fidelity in lemon sharks
- 2008
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Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 17:14, s. 3337-3351
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Tidskriftsartikel (refereegranskat)abstract
- We here employ 11 microsatellite markers and recently developed litter reconstruction methods to infer mating system parameters (i.e. polyandry and breeding-site fidelity) at a lemon shark nursery site in Marquesas Key, Florida. Four hundred and eight juvenile or subadult sharks were genotyped over eight complete breeding seasons. Using this information, we were able to infer family structure, as well as fully or partially reconstruct genotypes of 46 mothers and 163 fathers. Multiple litter reconstruction methods were used, and novel simulations helped define apparent bias and precision of at least some mating system parameters. For Marquesas Key, we find that adult female lemon sharks display high levels of polyandry (81% of all litters sampled) and stronger fidelity to the nursery site than do males. Indeed, few male sharks sired offspring from more than one litter during the course of the study. These findings were quite similar to previous results from another lemon shark nursery site (Bimini, Bahamas), suggesting conserved mating system parameters despite significant variation in early life-history traits (i.e. body size and growth) among sites. The finding of at least some site fidelity in females also supports the need for careful conservation of each nursery.
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| 13. |
- Herlogsson, Lars, et al.
(författare)
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Low-Voltage Polymer Field-Effect Transistors Gated Via a Proton Conductor
- 2007
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Ingår i: Advanced Materials. - : Wiley Online. - 0935-9648 .- 1521-4095. ; 19:1, s. 97-
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Tidskriftsartikel (refereegranskat)abstract
- Low operating voltages for p-channel organic field-effect transistors (OFETs) can be achieved by using an electrolyte as the gate insulator. However, mobile anions in the electrolyte can lead to undesired electrochemistry in the channel. In order to avoid this, a polyanionic electrolyte is used as the gate insulator. The resulting OFET has operating voltages of less than 1€‰V (see figure) shows fast switching (less than 0.3€‰ms) in ambient atmosphere._x000D_
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| 14. |
- Joura, Elmar A., et al.
(författare)
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HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine
- 2008
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Ingår i: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 26:52, s. 6844-6851
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Tidskriftsartikel (refereegranskat)abstract
- The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day I and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers. (C) 2008 Elsevier Ltd. All rights reserved.
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| 15. |
- Kahn, Kathleen, et al.
(författare)
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Research into health, population, and social transitions in rural South Africa : data and methods of the Agincourt health and demographic surveillance system
- 2007
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Ingår i: Scandinavian Journal of Public Health. - : Sage Publications. - 1403-4948 .- 1651-1905. ; 35:Suppl. 69, s. 8-20
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Tidskriftsartikel (refereegranskat)abstract
- Rationale for study: Vital registration is generally lacking in infrastructurally weak areas where health and development problems are most pressing. Health and demographic surveillance is a response to the lack of a valid information base that can provide high-quality longitudinal data on population dynamics, health, and social change to inform policy and practice. Design and measurement procedures: Continuous demographic monitoring of an entire geographically defined population involves a multi-round, prospective community study, with annual recording of all vital events (births, deaths, migrations). Status observations and special modules add value to particular research areas. A verbal autopsy is conducted on every death to determine its probable cause. A geographic surveillance system supports spatial analyses, and strengthens field management.Population and sample size considerations: Health and demographic surveillance covers the Agincourt sub-district population, sited in rural north-eastern South Africa, of some 70,000 people (nearly a third are Mozambican immigrants) in 21 villages and 11,700 households. Data enumerated are consistent or more detailed when compared with national sources; strategies to improve incomplete data, such as counts of perinatal deaths, have been introduced with positive effect.Basic characteristics: A major health and demographic transition was documented over a 12-year period with marked changes in population structure, escalating mortality, declining fertility, and high levels of temporary migration increasing particularly amongst women. A dual burden of infectious and non-communicable disease exists against a background of dramatically progressing HIV/AIDS.Potential and research questions: Health and demographic surveillance sites - fundamental to the INDEPTH Network - generate research questions and hypotheses from empirical data, highlight health, social and population priorities, provide cost-effective support for diverse study designs, and track population change and the impact of interventions over time.
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| 16. |
- McMullan, G, et al.
(författare)
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Electron imaging with medipix2 hybrid pixel detector
- 2007
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Ingår i: Ultramicroscopy. - : Elsevier BV. - 0304-3991 .- 1879-2723. ; 107:4-5, s. 401-413
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Tidskriftsartikel (refereegranskat)abstract
- The electron imaging performance of Medipix2 is described. Medipix2 is a hybrid pixel detector composed of two layers. It has a sensor layer and a layer of readout electronics, in which each 55 μm×55 μm pixel has upper and lower energy discrimination and MHz rate counting. The sensor layer consists of a 300 μm slab of pixellated monolithic silicon and this is bonded to the readout chip. Experimental measurement of the detective quantum efficiency, DQE(0) at 120 keV shows that it can reach 85% independent of electron exposure, since the detector has zero noise, and the DQE(Nyquist) can reach 35% of that expected for a perfect detector (4/π2). Experimental measurement of the modulation transfer function (MTF) at Nyquist resolution for 120 keV electrons using a 60 keV lower energy threshold, yields a value that is 50% of that expected for a perfect detector (2/π). Finally, Monte Carlo simulations of electron tracks and energy deposited in adjacent pixels have been performed and used to calculate expected values for the MTF and DQE as a function of the threshold energy. The good agreement between theory and experiment allows suggestions for further improvements to be made with confidence. The present detector is already very useful for experiments that require a high DQE at very low doses.
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| 17. |
- Moss, Brian D., et al.
(författare)
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Climate change and the future of freshwater biodiversity in Europe : a primer for policy-makers
- 2009
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Ingår i: Freshwater Reviews. - : Freshwater Biological Association. - 1755-084X. ; 2:2, s. 103-130
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Tidskriftsartikel (refereegranskat)abstract
- Earth's climate is changing, and by the end of the 21st century in Europe, average temperatures are likely to have risen by at least 2 °C, and more likely 4 °C with associated effects on patterns of precipitation and the frequency of extreme weather events. Attention among policy-makers is divided about how to minimise the change, how to mitigate its effects, how to maintain the natural resources on which societies depend and how to adapt human societies to the changes. Natural systems are still seen, through a long tradition of conservation management that is largely species-based, as amenable to adaptive management, and biodiversity, mostly perceived as the richness of plant and vertebrate communities, often forms a focus for planning. We argue that prediction of particular species changes will be possible only in a minority of cases but that prediction of trends in general structure and operation of four generic freshwater ecosystems (erosive rivers, depositional floodplain rivers, shallow lakes and deep lakes) in three broad zones of Europe (Mediterranean, Central and Arctic-Boreal) is practicable. Maintenance and rehabilitation of ecological structures and operations will inevitably and incidentally embrace restoration of appropriate levels of species biodiversity. Using expert judgement, based on an extensive literature, we have outlined, primarily for lay policy makers, the pristine features of these systems, their states under current human impacts, how these states are likely to alter with a warming of 2 °C to 4 °C and what might be done to mitigate this. We have avoided technical terms in the interests of communication, and although we have included full referencing as in academic papers, we have eliminated degrees of detail that could confuse broad policy-making
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| 18. |
- Rönn, Ann-Charlotte, et al.
(författare)
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Multiple displacement amplification for generating an unlimited source of DNA for genotyping in nonhuman primate species
- 2006
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Ingår i: International journal of primatology. - : Springer Science and Business Media LLC. - 0164-0291 .- 1573-8604. ; 27:4, s. 1145-1169
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated a whole genome amplification method-multiple displacement amplification (MDA)-as a means to conserve valuable nonhuman primate samples. We tested 148 samples from a variety of species and sample sources, including blood, tissue, cell-lines, plucked hair and noninvasively collected semen. To evaluate genotyping success and accuracy of MDA, we used routine genotyping methods, including short tandem repeat (STR) analysis, denaturing gradient gel electrophoresis (DGGE), Alu repeat analysis, direct sequencing, and nucleotide detection by tag-array minisequencing. We compared genotyping results from MDA products to genotypes generated from the original (non-MD amplified) DNA samples. All genotyping methods showed good results with the MDA products as a DNA template, and for some samples MDA improved genotyping success. We show that the MDA procedure has the potential to provide a long-lasting source of DNA for genetic studies, which would be highly valuable for the primate research field, in which genetic resources are limited and for other species in which similar sampling constraints apply.
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| 19. |
- Said, Elias, 1975-, et al.
(författare)
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Polymer field-effect transistor gated via a poly(styrenesulfonic acid) thin film
- 2006
-
Ingår i: Applied Physics Letters. - : American Institute of Physics. - 0003-6951 .- 1077-3118. ; 89:14, s. 143507-
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Tidskriftsartikel (refereegranskat)abstract
- A polyanionic proton conductor, named poly(styrenesulfonic acid) (PSSH), is used to gate an organic field-effect transistor (OFET) based on poly(3-hexylthiophene) (P3HT). Upon applying a gate bias, large electric double layer capacitors (EDLCs) are formed quickly at the gate-PSSH and P3HT-PSSH interfaces due to proton migration in the polyelectrolyte. This type of robust transistor, called an EDLC-OFET, displays fast response (<1 ms) and operates at low voltages (<1 V). The results presented are relevant for low-cost printed polymer electronics.
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| 20. |
- Tehrani, Payman, 1977-, et al.
(författare)
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The effect of pH on the elechtrochemical over-oxidation of PEDOT:PSS films
- 2007
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Ingår i: Solid State Ionics. - : ScienceDirect. - 0167-2738 .- 1872-7689. ; 177:39-40, s. 3521-3527
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Tidskriftsartikel (refereegranskat)abstract
- Chemical degradation of conjugated polymers is one cause of material failures in polymer-based (opto)electronic devices, but can also be used as a technique for subtractive patterning of polymer films. When a large anodic potential is applied to the conducting polymer blend poly(3,4-ethylenedioxythiophene)-poly(4styrenesulfonate), PEDOT:PSS, an over-oxidation reaction occurs, altering its electrical conductivity. Here, we have studied the effect of pH on the electrochemical over-oxidation process of PEDOT in PEDOT:PSS. High pH is associated with a decrease of over-oxidation potential and an increase of resistivity in the resulting film. Vibrational spectroscopy and photoelectron spectroscopy measurements on over-oxidized PEDOT:PSS films indicate that the decrease in conductivity results from cleavage of the conjugation pathway accompanied by the formation of sulfone, carbonyl and carboxylic groups in the polymer chain.
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