| 1. |
- Campbell, PJ, et al.
(författare)
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Pan-cancer analysis of whole genomes
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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| 2. |
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| 3. |
- Meng, X. X. Y., et al.
(författare)
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Humidity-Dependent Phase State of Gasoline Vehicle Emission-Related Aerosols
- 2021
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:2, s. 832-841
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Tidskriftsartikel (refereegranskat)abstract
- The phase states of primarily emitted and secondarily formed aerosols from gasoline vehicle exhausts were investigated by quantifying the particle rebound fraction (f). The rebound behaviors of gasoline vehicle emission-related aerosols varied with engines, fuel types, and photochemical aging time, showing distinguished differences from biogenic secondary organic aerosols. The nonliquid-to-liquid phase transition of primary aerosols emitted from port fuel injection (PFI) and gasoline direct injection (GDI) vehicles started at a relative humidity (RH) = 50 and 60%, and liquefaction was accomplished at 60 and 70%, respectively. The RH at which f declined to 0.5 decreased from 70 to 65% for the PFI case with 92# fuel, corresponding to the photochemical aging time from 0.37 to 4.62 days. For the GDI case, such RH enhanced from 60 to 65%. Our results can be used to imply the phase state of traffic-related aerosols and further understand their roles in urban atmospheric chemistry. Taking Beijing, China, as an example, traffic-related aerosols were mainly nonliquid during winter with the majority ambient RH below 50%, whereas they were mostly liquid during the morning rush hour of summer, and traffic-related secondary aerosols fluctuated between nonliquid and liquid during the daytime and tended to be liquid at night with increased ambient RH.
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| 4. |
- Yu, G., et al.
(författare)
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Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles
- 2005
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 127:17, s. 6335-6346
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Forskningsöversikt (refereegranskat)abstract
- The excellent electroluminescent (EL) properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles, 1-methyl-1,2,3,4,5-pentaphenylsilole (MPPS), and 1,1,2,3,4,5-hexaphenylsilole (HPS) have been found. Despite some studies devoted to these materials, very little is known about the real origin of their unique EL properties. Therefore, we investigated the structures, photoluminescence (PL), and charge carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles as well as the effect of substituents on these characteristics. The single crystals of the three siloles involving 1,1-dimethyl-2,3,4,5-tetraphenylsilole (DMTPS), MPPS, and HIPS were grown and their crystal structures were determined by X-ray diffraction. Three siloles have nonplanar molecular structures. The substituents at 1,1-positions enhance the steric hindrance and have predominant influence on the twisted degree of phenyl groups at ring carbons. This nonplanar structure reduces the intermolecular interaction and the likelihood of excimer formation, and increases PL efficiency in the solid state. The silole films show high fluorescence quantum yields (75-85%), whereas their dilute solutions exhibit a faint emission. The electronic structures of the three siloles were investigated using quantum chemical calculations. The highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular orbitals (LUMOs) are mainly localized on the silole ring and two phenyl groups at 2,5-positions in all cases, while the LUMOs have a significant orbital density at two exocyclic Si-C bonds. The extremely theoretical studies of luminescent properties were carried out. We calculated the nonradiative decay rate of the first excited state as well as the radiative one. It is found that the faint emission of DMTPS in solutions mainly results from the huge nonradiative decay rate. In solid states, molecular packing can remarkably restrict the intramolecular rotation of the peripheral side phenyl ring, which has a large contribution to the nonradiative transition process. This explains why the 1,1-disubstituted 2,3,4,5-tetraphenylsiloles in the thin films exhibit high fluorescence quantum yields. The charge carrier mobilities of the MPPS and HPS films were measured using a transient EL technique. We obtained a mobility of 2.1 x 10(-6) cm(2)/V(.)s in the MPPS film at an electric field of 1.2 x 10(6) V/cm. This mobility is comparable to that of Alq(3), which is one of the most extensively used electron transport materials in organic light-emitting diodes (LEDs), at the same electric field. The electron mobility of the HPS film is about similar to 1.5 times higher than that of the MPPS film. To the best of our knowledge, this kind of material is one of the most excellent emissive materials that possess both high charge carrier mobility and high PL efficiency in the solid states simultaneously. The excellent EL performances of MPPS and HPS are presumably ascribed to these characteristics.
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| 5. |
- Carlevaro-Fita, J, et al.
(författare)
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Cancer LncRNA Census reveals evidence for deep functional conservation of long noncoding RNAs in tumorigenesis
- 2020
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Ingår i: Communications biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1, s. 56-
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Tidskriftsartikel (refereegranskat)abstract
- Long non-coding RNAs (lncRNAs) are a growing focus of cancer genomics studies, creating the need for a resource of lncRNAs with validated cancer roles. Furthermore, it remains debated whether mutated lncRNAs can drive tumorigenesis, and whether such functions could be conserved during evolution. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, we introduce the Cancer LncRNA Census (CLC), a compilation of 122 GENCODE lncRNAs with causal roles in cancer phenotypes. In contrast to existing databases, CLC requires strong functional or genetic evidence. CLC genes are enriched amongst driver genes predicted from somatic mutations, and display characteristic genomic features. Strikingly, CLC genes are enriched for driver mutations from unbiased, genome-wide transposon-mutagenesis screens in mice. We identified 10 tumour-causing mutations in orthologues of 8 lncRNAs, including LINC-PINT and NEAT1, but not MALAT1. Thus CLC represents a dataset of high-confidence cancer lncRNAs. Mutagenesis maps are a novel means for identifying deeply-conserved roles of lncRNAs in tumorigenesis.
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| 6. |
- Chuwongin, S., et al.
(författare)
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Nanomembrane transfer printing for MR-VCSELs on silicon
- 2012
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Ingår i: 2012 IEEE Photonics Conference, IPC 2012. - : IEEE. - 9781457707315 ; , s. 951-952
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Konferensbidrag (refereegranskat)abstract
- The creation of silicon based light sources has been a major research and development effort world-wide. Among various approaches to silicon based light sources reported thus far, the hybrid gain-medium approach (especially integrated with group III-V materials) seems to be the most promising one due to its higher efficiencies than any others. [1-3]
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| 7. |
- Hu, W., et al.
(författare)
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Electron transport in self-assembled polymer molecular junctions
- 2006
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 96:2, s. 027801-
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Tidskriftsartikel (refereegranskat)abstract
- A molecular junction of a poly(p-phenyleneethynylene)s derivative with thioacetate end groups (TA-PPE) was fabricated by self-assembling. Nanogap electrodes made by electroplating technique was used to couple thiol end groups of TA-PPE molecules. Room temperature current-voltage characteristics of the molecular junction exhibited highly periodic, repeatable, and identical stepwise features. First-principles calculations suggest that one possibility for the equidistant step is due to the opening of different conducting channels that corresponds to the unoccupied molecular orbitals of the polymer in the junction. It is interesting to see that an 18 nm long polymer is of quantized electronic structures and behaves like a quantum transport device.
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| 8. |
- Khan, S N, et al.
(författare)
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Modified square uwb monopole antenna for improved impedance bandwidth
- 2008
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Ingår i: Journal Electromagnetic Waves and Applications. - : Informa UK Limited. - 0920-5071 .- 1569-3937. ; 22:14-15, s. 1883-1888
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Tidskriftsartikel (refereegranskat)abstract
- Square monopole is modified to improve the impedance bandwidth. The modified square monopole has a step-generated circular base. The measured return loss below -10 dB is from 2.42 GHz to over 20GHz and good omnidirectional radiation pattern is also achieved.
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| 9. |
- Pan, T., et al.
(författare)
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Compact circularly polarized RFID tag antenna with an embedded U-shaped feedline for metallic surfaces
- 2014
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Ingår i: Progress in Electromagnetics Research Symposium. - 9781934142288 ; , s. 1567-1571
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Konferensbidrag (refereegranskat)abstract
- A passive radio frequency identification (RFID) tag antenna with circular polarization (CP) radiation is proposed to operate at 902-928MHz and mount on metallic surfaces. A U-shaped terminal short-circuited feedline welded to a tag-chip is embedded in a rectangular slot to achieve a coupled feeding and a good impedance matching. By employing two truncated corners and two L-shaped slots with unequal length on the patch, a good left-hand circular polarization (LHCP) and compact size are obtained. The measured impedance bandwidth of the antenna is 85MHz (875-960 MHz), while the simulated 3-dB CP bandwidth is 6MHz (912-918 MHz). The proposed tag antenna shows reasonable read ranges when mounted on the metal plate in the following experiment.
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| 10. |
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| 11. |
- Rheinbay, E, et al.
(författare)
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Analyses of non-coding somatic drivers in 2,658 cancer whole genomes
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 102-
-
Tidskriftsartikel (refereegranskat)abstract
- The discovery of drivers of cancer has traditionally focused on protein-coding genes1–4. Here we present analyses of driver point mutations and structural variants in non-coding regions across 2,658 genomes from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium5 of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). For point mutations, we developed a statistically rigorous strategy for combining significance levels from multiple methods of driver discovery that overcomes the limitations of individual methods. For structural variants, we present two methods of driver discovery, and identify regions that are significantly affected by recurrent breakpoints and recurrent somatic juxtapositions. Our analyses confirm previously reported drivers6,7, raise doubts about others and identify novel candidates, including point mutations in the 5′ region of TP53, in the 3′ untranslated regions of NFKBIZ and TOB1, focal deletions in BRD4 and rearrangements in the loci of AKR1C genes. We show that although point mutations and structural variants that drive cancer are less frequent in non-coding genes and regulatory sequences than in protein-coding genes, additional examples of these drivers will be found as more cancer genomes become available.
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| 12. |
- Wang, Mengmeng, et al.
(författare)
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Statistical analysis of whistler precursors upstream of foreshock transient shocks : MMS observations
- 2024
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 51:8
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Tidskriftsartikel (refereegranskat)abstract
- Using the high-time-resolution data from the Magnetospheric Multiscale mission, precursor waves upstream of foreshock transient (FT) shocks are statistically investigated using the four-spacecraft timing method. The wave frequencies and wave vectors determined in the plasma rest frame (PRF) are shown to follow the cold plasma dispersion relation for whistler waves. Combining with the feature of the right-hand polarization in the PRF, the precursors are identified as whistler-mode waves around the lower hybrid frequency. The occurrence of whistler precursors is independent of the Alfvén Mach number and the FT shock normal angle. More importantly, all the whistler precursors have group velocities pointing upstream in the shock frame, suggesting the dispersive radiation to be a possible generation mechanism. The study improves the understanding of not only the whistler precursors but also the overall FT shock dynamics.
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| 13. |
- Yang, H., et al.
(författare)
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Transfer-printed stacked nanomembrane lasers on silicon
- 2012
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Ingår i: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 6:9, s. 615-620
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Tidskriftsartikel (refereegranskat)abstract
- The realization of silicon-based light sources has been the subject of a major research and development effort worldwide. Such sources may help make integrated photonic and electronic circuitry more cost-effective, with higher performance and greater energy efficiency. The hybrid approach, in which silicon is integrated with a III-V gain medium, is an attractive route in the development of silicon lasers because of its potential for high efficiency. Hybrid lasers with good performance have been reported that are fabricated by direct growth or direct wafer-bonding of the gain medium to silicon. Here, we report a membrane reflector surface-emitting laser on silicon that is based on multilayer semiconductor nanomembrane stacking and a stamp-assisted transfer-printing process. The optically pumped laser consists of a transferred III-V InGaAsP quantum-well heterostructure as the gain medium, which is sandwiched between two thin, single-layer silicon photonic-crystal Fano resonance membrane reflectors. We also demonstrate high-finesse single-or multiwavelength vertical laser cavities.
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| 14. |
- Yin, S., et al.
(författare)
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Aggregation-enhanced luminescence and vibronic coupling of silole molecules from first principles
- 2006
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 73:20, s. 205409-
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Tidskriftsartikel (refereegranskat)abstract
- Aggregate formation in molecular solids usually quenches the luminescence, a piece of bad news for molecular electronic devices. However, siloles present extremely high luminescent efficiency in solid state as well as in aggregation, but have almost no luminescence in solution. By employing a first-principles calculation to study excited states and vibronic couplings, we find that it is the low-frequency twisting motions of side rings which enhance the nonradiative decay. These motions can be suppressed either by solid-state packing, by aggregation formation in polar solvents, or by increasing the solvent viscosity; thereby, the radiative decay becomes dominant, resulting in peculiar aggregate-induced emission phenomena in siloles.
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| 15. |
- Zhang, Shuai, et al.
(författare)
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Body-effect-adaptive compact wideband LTE MIMO antenna array with quad elements for mobile terminals
- 2013
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Ingår i: PIERS Proceedings, Stockholm, Sweden, Aug. 12{15, 2013. - : Electromagnetics Academy. - 9781934142264 ; , s. 1858-1861
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Konferensbidrag (refereegranskat)abstract
- A body-effect-adaptive compact wideband LTE MIMO antenna array with quad elements for mobile terminals is proposed in this paper. It can cover the bands of 750-960 and 1700-2700MHz with a low envelope correlation coefficient. Through different combinations two of the four elements can be utilized as dual element LTE MIMO antenna array to reduce three kinds of body effects (head and hand; single hand; dual hands) with the other two ports open. Some common rules about the body effects are introduced. The conclusions about the optimal chassis locations of LTE MIMO antenna elements to improve MIMO performance are also presented.
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| 16. |
- Zhang, Shuai, et al.
(författare)
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Investigation of Diagonal Antenna-Chassis Mode in Mobile Terminal LTE MIMO Antennas for Bandwidth Enhancement
- 2015
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Ingår i: IEEE Antennas & Propagation Magazine. - 1045-9243 .- 1558-4143. ; 57:2, s. 217-228
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Tidskriftsartikel (refereegranskat)abstract
- A diagonal antenna-chassis mode is investigated in long-term evolution multiple-input-multiple-output (LTE MIMO) antennas. The MIMO bandwidth is defined in this paper as the overlap range of the low-envelope correlation coefficient, high total efficiency, and -6-dB impedance matching bandwidths. Utilizing the diagonal mode analysis, the MIMO bandwidth of the collocated MIMO antennas is improved efficiently at the frequencies of lower than 960 MHz. This is realized through moving the three bandwidths to the same range without the degradation of impedance bandwidth and total efficiency. The physical mechanism of the mismatch of these three bandwidth ranges is also explained. Furthermore, the diagonal antenna-chassis mode is also studied for MIMO elements in the adjacent and diagonal corner locations. As a practical example, a wideband collocated LTE MIMO antenna is proposed and measured. It covers the bands of 740-960 and 1700-2700 MHz, where the total efficiencies are better than -3.4 and -1.8 dB, with ρe lower than 0.5 and 0.1, respectively. The measurements agree well with the simulations. Since the proposed method only needs to modify the excitation locations of the MIMO elements on the chassis, this method is valid for different types of symmetrical or asymmetrical MIMO antennas to improve the MIMO bandwidth.
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| 17. |
- Zhang, Shuai, et al.
(författare)
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Mutual scattering mode for LTE MIMO antennas and its application to correlation reduction (invited)
- 2012
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Ingår i: Antennas and Propagation (APCAP), 2012 IEEE Asia-Pacific Conference on. - : IEEE. - 9781467306676 ; , s. 13-14
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Konferensbidrag (refereegranskat)abstract
- A - mutual scattering mode -is introduced in this paper as a novel method to reduce the correlation for the LTE MIMO antenna arrays. This mode is mainly based on the increase of the Q factor for the closely-positioned MIMO antenna elements. With the increased Q factor, each element becomes a scatter for the other elements. Consequently, without adding any structure in the MIMO system, the radiation patterns will be separated to achieve a low correlation (even close to zero) in LTE 700 MHz bands. In practice, this high Q factor is realized through better impedance matching, which makes this mode quite easy to excite. When the effective MIMO element distance is larger than a certain value, better matching (higher Q factor) can not only reduce the correlation but also improve the efficiency (even though the mutual coupling becomes stronger).
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| 18. |
- Zhao, Kun, et al.
(författare)
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Impact of size and decoupling element on some fundamental compact MIMO antennas
- 2014
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Ingår i: 2014 International Workshop on Antenna Technology. - 9781479923298 ; , s. 136-139
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Konferensbidrag (refereegranskat)abstract
- The effective bandwidth of fundamental MIMO antennas (ideal MIMO Dipole and ideal MIMO monopole) are studied in this paper. The S11 bandwidth, total efficiency bandwidth and envelope correlation coefficient bandwidth are shown, and effects from antenna sizes, matching and decoupling networks are analyzed. Furthermore, the effective bandwidth of MIMO antennas is defined in this paper as the overlap part of above three bandwidths; it can show a comprehensive performance of the MIMO system.
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| 19. |
- Zhao, Kun, et al.
(författare)
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SAR study for smart watch applications
- 2014
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Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - : IEEE conference proceedings. - 9781479935406 ; , s. 1198-1199
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Konferensbidrag (refereegranskat)abstract
- In this paper, we investigate the SAR performance of an IFA antenna for the smart watch application. The SAR performance is evaluated by both body shape phantoms and FCC standard flat phantoms. Differences of the SAR performance in different phantoms are compared and discussed.
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| 20. |
- Zhao, Kun, et al.
(författare)
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SAR study of different MIMO antenna designs for LTE application in smart mobile handsets
- 2013
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 61:6, s. 3270-3279
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Tidskriftsartikel (refereegranskat)abstract
- This paper mainly focuses on the specific absorption rate (SAR) of the dual-element LTE MIMO antenna in mobile phones. Four designs of dual-element MIMO antenna (namely, dual semi-ground-free planar inverted-F antenna (PIFA), co-located antenna, dual OG PIFA in parallel position, and dual OG PIFA in orthogonal position) are studied under four typical LTE frequency points (0.75, 0.85, 1.9, and 2.1/2.6 GHz) when the ground plane length varies from 90 to 150 mm. The SAR, when dual elements operate simultaneously, is also studied through the SAR to PEAK location spacing ratio (SPLSR) according to the FCC standard. The simulations are carried out on both an SAM head phantom and a flat phantom by CST 2011, and measurements on the flat phantom are made with iSAR and DASY4 to verify the accuracy of our simulations.
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| 21. |
- Zhao, Kun, et al.
(författare)
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SAR study of different MIMO antenna designs for LTE application in smart mobile phones
- 2012
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Ingår i: Antennas and Propagation Society International Symposium (APSURSI), 2012 IEEE. - : IEEE. - 9781467304627 ; , s. 6348485-
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Konferensbidrag (refereegranskat)abstract
- This paper reports a study of specific absorption rate (SAR) for LTE MIMO antennas in mobile phones, with special consideration to the effects of different chassis lengths and different types of MIMO antennas. Two designs of dual elements MIMO antenna are studied under two typical LTE and mobile phone frequency points. The simulations are carried out both for a specific anthropomorphic mannequin (SAM) head phantom and a flat phantom. The measurements on the flat phantom are carried out as well to verify our simulation results.
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| 22. |
- Zhao, Y. S., et al.
(författare)
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Single crystalline submicrotubes from small organic molecules
- 2005
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 17:25, s. 6430-6435
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Tidskriftsartikel (refereegranskat)abstract
- The single crystalline submicrotubes of a small organic functional molecule, 2,4,5-triphenylimidazole (TPI), were successfully prepared with a facile method. A series of characterizations indicated that the tubes were obtained from the rolling followed by seaming of a preorganized two-dimensional sheet-like structure, whose formation was due to the efficient cooperation of several molecular recognition elements. The length and diameter of the TPI tubes can be readily controlled by adjusting the experimental conditions. The as-prepared submicrotubes have intensive luminescence and size-dependent optical properties, which allows them to find potential applications in novel optical and optoelectronic devices together with their single crystalline structure and good stability. The strategy described here should give a useful enlightenment for the design and fabrication of tubular structures from small organic molecules.
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