| 1. |
- Elks, Cathy E, et al.
(författare)
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Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:12, s. 1077-85
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Tidskriftsartikel (refereegranskat)abstract
- To identify loci for age at menarche, we performed a meta-analysis of 32 genome-wide association studies in 87,802 women of European descent, with replication in up to 14,731 women. In addition to the known loci at LIN28B (P = 5.4 × 10⁻⁶⁰) and 9q31.2 (P = 2.2 × 10⁻³³), we identified 30 new menarche loci (all P < 5 × 10⁻⁸) and found suggestive evidence for a further 10 loci (P < 1.9 × 10⁻⁶). The new loci included four previously associated with body mass index (in or near FTO, SEC16B, TRA2B and TMEM18), three in or near other genes implicated in energy homeostasis (BSX, CRTC1 and MCHR2) and three in or near genes implicated in hormonal regulation (INHBA, PCSK2 and RXRG). Ingenuity and gene-set enrichment pathway analyses identified coenzyme A and fatty acid biosynthesis as biological processes related to menarche timing.
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| 2. |
- Coucheron, David A., et al.
(författare)
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Laser recrystallization and inscription of compositional microstructures in crystalline SiGe-core fibres
- 2016
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Glass fibres with silicon cores have emerged as a versatile platform for all-optical processing, sensing and microscale optoelectronic devices. Using SiGe in the core extends the accessible wavelength range and potential optical functionality because the bandgap and optical properties can be tuned by changing the composition. However, silicon and germanium segregate unevenly during non-equilibrium solidification, presenting new fabrication challenges, and requiring detailed studies of the alloy crystallization dynamics in the fibre geometry. We report the fabrication of SiGe-core optical fibres, and the use of CO2 laser irradiation to heat the glass cladding and recrystallize the core, improving optical transmission. We observe the ramifications of the classic models of solidification at the microscale, and demonstrate suppression of constitutional undercooling at high solidification velocities. Tailoring the recrystallization conditions allows formation of long single crystals with uniform composition, as well as fabrication of compositional microstructures, such as gratings, within the fibre core.
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| 3. |
- Huang, Meng, et al.
(författare)
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Continuous-wave Raman amplification in silicon core fibers pumped in the telecom band
- 2021
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Ingår i: APL PHOTONICS. - : AIP Publishing. - 2378-0967. ; 6:9, s. 096105-
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Tidskriftsartikel (refereegranskat)abstract
- Stimulated Raman amplification is observed for the first time in the silicon core fiber (SCF) platform. The SCFs were tapered to obtain sub-micrometer core dimensions and low optical transmission losses, facilitating efficient spontaneous scattering and stimulated Raman amplification using a continuous-wave pump source with milliwatt power levels. A maximum on-off gain of 1.1 dB was recorded at a pump power of only 48 mW with our numerical simulations, indicating that gains up to 6dB are achievable by increasing the fiber length. This work shows that the SCF platform could open a route to producing compact and robust all-fiber integrated Raman amplifiers and lasers across a broad wavelength region.
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| 4. |
- Huang, Meng, et al.
(författare)
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Fiber Integrated Wavelength Converter Based on a Silicon Core Fiber With a Nano-Spike Coupler
- 2019
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Ingår i: IEEE Photonics Technology Letters. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1041-1135 .- 1941-0174. ; 31:19, s. 1561-1564
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Tidskriftsartikel (refereegranskat)abstract
- An all-fiber integrated nonlinear silicon photonic wavelength converter has been proposed and fabricated using the silicon core fiber platform. The silicon fiber was spliced directly to a conventional single mode fiber, facilitated via an inverse tapered nano-spike that helped to reduce the mode mismatch between the different core materials. Four-wave mixing-based wavelength conversion with an efficiency as high as -22.1 dB has been achieved for selected wavelengths across the C-band in a device length of only similar to 1 cm. Successful conversion of quadrature phase-shift keying signals at a 20-Gb/s bitrate, with a 1 to 2 dB penalty level at the bit error ratio (BER) = 3.8 x 10(-3), was used to demonstrate the suitability of the silicon fiber device for the construction of ultra-compact, all-fiber-based optical signal processing systems.
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| 5. |
- Minzioni, Paolo, et al.
(författare)
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Roadmap on all-optical processing
- 2019
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Ingår i: Journal of Optics. - : IOP Publishing. - 2040-8978 .- 2040-8986. ; 21:6
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Tidskriftsartikel (refereegranskat)abstract
- The ability to process optical signals without passing into the electrical domain has always attracted the attention of the research community. Processing photons by photons unfolds new scenarios, in principle allowing for unseen signal processing and computing capabilities. Optical computation can be seen as a large scientific field in which researchers operate, trying to find solutions to their specific needs by different approaches; although the challenges can be substantially different, they are typically addressed using knowledge and technological platforms that are shared across the whole field. This significant know-how can also benefit other scientific communities, providing lateral solutions to their problems, as well as leading to novel applications. The aim of this Roadmap is to provide a broad view of the state-of-the-art in this lively scientific research field and to discuss the advances required to tackle emerging challenges, thanks to contributions authored by experts affiliated to both academic institutions and high-tech industries. The Roadmap is organized so as to put side by side contributions on different aspects of optical processing, aiming to enhance the cross-contamination of ideas between scientists working in three different fields of photonics: optical gates and logical units, high bit-rate signal processing and optical quantum computing. The ultimate intent of this paper is to provide guidance for young scientists as well as providing research-funding institutions and stake holders with a comprehensive overview of perspectives and opportunities offered by this research field.
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| 6. |
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| 7. |
- Wang, Thomas J, et al.
(författare)
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Common genetic determinants of vitamin D insufficiency: a genome-wide association study.
- 2010
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Ingår i: Lancet. - 1474-547X. ; 376:9736, s. 180-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Vitamin D is crucial for maintenance of musculoskeletal health, and might also have a role in extraskeletal tissues. Determinants of circulating 25-hydroxyvitamin D concentrations include sun exposure and diet, but high heritability suggests that genetic factors could also play a part. We aimed to identify common genetic variants affecting vitamin D concentrations and risk of insufficiency. METHODS: We undertook a genome-wide association study of 25-hydroxyvitamin D concentrations in 33 996 individuals of European descent from 15 cohorts. Five epidemiological cohorts were designated as discovery cohorts (n=16 125), five as in-silico replication cohorts (n=9367), and five as de-novo replication cohorts (n=8504). 25-hydroxyvitamin D concentrations were measured by radioimmunoassay, chemiluminescent assay, ELISA, or mass spectrometry. Vitamin D insufficiency was defined as concentrations lower than 75 nmol/L or 50 nmol/L. We combined results of genome-wide analyses across cohorts using Z-score-weighted meta-analysis. Genotype scores were constructed for confirmed variants. FINDINGS: Variants at three loci reached genome-wide significance in discovery cohorts for association with 25-hydroxyvitamin D concentrations, and were confirmed in replication cohorts: 4p12 (overall p=1.9x10(-109) for rs2282679, in GC); 11q12 (p=2.1x10(-27) for rs12785878, near DHCR7); and 11p15 (p=3.3x10(-20) for rs10741657, near CYP2R1). Variants at an additional locus (20q13, CYP24A1) were genome-wide significant in the pooled sample (p=6.0x10(-10) for rs6013897). Participants with a genotype score (combining the three confirmed variants) in the highest quartile were at increased risk of having 25-hydroxyvitamin D concentrations lower than 75 nmol/L (OR 2.47, 95% CI 2.20-2.78, p=2.3x10(-48)) or lower than 50 nmol/L (1.92, 1.70-2.16, p=1.0x10(-26)) compared with those in the lowest quartile. INTERPRETATION: Variants near genes involved in cholesterol synthesis, hydroxylation, and vitamin D transport affect vitamin D status. Genetic variation at these loci identifies individuals who have substantially raised risk of vitamin D insufficiency. FUNDING: Full funding sources listed at end of paper (see Acknowledgments).
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| 8. |
- Wu, Dong, et al.
(författare)
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Four-Wave Mixing-Based Wavelength Conversion and Parametric Amplification in Submicron Silicon Core Fibers
- 2021
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-260X .- 1558-4542. ; 27:2
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Tidskriftsartikel (refereegranskat)abstract
- Silicon core fibers represent a versatile platform for all-fiber integrated nonlinear optical applications. This paper describes the state of the art in four-wave mixing-based parametric amplification, and wavelength conversion in silicon fibers that have been tapered to improve the material quality, and engineer the dispersion profile. Fibers with submicron core dimensions have been fabricated, and used to demonstrate high gain parametric amplification in the C-Band, and broadband wavelength conversion extending out to the S-, and L-bands. The potential to use these fibers for all-optical signal processing of 20 Gbit/s data signals has also been demonstrated, with a robust all-fiber coupling scheme presented to improve the efficiency, and practicality of these devices. These results highlight the potential of silicon core fibers for use in nonlinear signal processing within future telecommunication systems.
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| 9. |
- Wu, Dong, et al.
(författare)
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Net optical parametric gain in a submicron silicon core fiber pumped in the telecom band
- 2019
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Ingår i: APL Photonics. - : AIP Publishing. - 2378-0967. ; 4:8
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Tidskriftsartikel (refereegranskat)abstract
- A silicon core fiber (SCF) has been designed and fabricated with a dispersion engineered profile to support broadband optical parametric amplification across the telecom window. The combination of low optical transmission losses and high coupling efficiency of the SCF platform has allowed for an on-off optical parametric gain up to 9 dB, without experiencing gain saturation due to nonlinear absorption, resulting in a net off-waveguide gain of similar to 2 dB. The ability to splice the SCFs with conventional silica fiber systems opens a route to compact and robust all-fiber integrated optical parametric amplifiers and oscillators that could find use in telecoms systems.
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