| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Sodergren, Erica, et al.
(författare)
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The genome of the sea urchin Strongylocentrotus purpuratus.
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 941-52
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Tidskriftsartikel (refereegranskat)abstract
- We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
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| 3. |
- Yun, Younsuk, et al.
(författare)
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Atomic diffusion mechanism of Xe in UO2
- 2008
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 378:1, s. 40-44
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated vacancy-assisted diffusion of Xe in uranium dioxide MOO calculating incorporation, binding, and migration energies. All the energy values have been obtained using the density functional theory (DFT) within the generalized gradient approximation (GGA) and the projector-augmented-wave (PAW) method. Considering spin-polarization effect, we find that the computed migration energy is reduced by and agrees well with experimental data compared to those obtained from nonmagnetic calculations. We also find that an oxygen vacancy lowers the migration energy of a uranium vacancy by about 1 eV, enhancing an effective movement of vacancy clusters consisting of both uranium and oxygen vacancies. Furthermore, the strain energy of Xe is large enough to contribute to the clustering of vacancies making it the driving force for the vacancy-assisted diffusion of Xe in UO2. In summary all the calculated results suggest that the trivacancy is a major diffusion pathway of Xe in UO2.
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| 4. |
- Do, Tan Tai, et al.
(författare)
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Cooperative diversity for wireless multicast transmission with truncated ARQ
- 2009
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Ingår i: 2009 9th International Symposium on Communications and Information Technology, ISCIT 2009. ; , s. 947-948
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a cooperative diversity protocol with truncated automatic repeat request (ARQ) for multicast transmission. The proposed method employs SNR threshold-based selective relaying for distributed space time block coding for retransmission. Numerical results will show that the proposed method with optimal SNR threshold improves the error and throughput performance remarkably.
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| 5. |
- Do, Tan Tai, et al.
(författare)
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Cross-Layer Design of Adaptive Wireless Multicast Transmission with Truncated HARQ
- 2009
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Ingår i: 2009 IEEE VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-5. - 9781424425167 ; , s. 1879-1883
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Konferensbidrag (refereegranskat)abstract
- This paper presents a cross-layer design of adaptive modulation and coding (AMC) with truncated hybrid automatic repeat request (HARQ) for one-to-many multicast transmission, in order to increase the spectral efficiency under the quality-of-service (QoS) constraints. For adaptive transmission over the channel common to the multicast group users, the AMC mode is chosen with the minimum SNR among the users to guarantee the target performance of all users. In the meanwhile, the minimum SNR required to support an AMC mode is aggressively designed by allowing retransmission with HARQ schemes. For the proposed design, we derive the average packet error rate, average number of transmission, and spectral efficiency and provide the performance numerically obtained. Numerical results show that the cross-layer design for multicast provides a significant performance gain at a small number of retransmissions as in unicast. In particular, it is observed that AMC design with HARQ is more beneficial in the low SNR region where multicast performs worse than unicast
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| 6. |
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| 7. |
- Li, Shanghua, et al.
(författare)
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Bulk synthesis of transparent and homogeneous polymeric hybrid materials with ZnO quantum dots and PMMA
- 2007
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 19:24, s. 4347-
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Tidskriftsartikel (refereegranskat)abstract
- [GRAPHICS] In situ sol-gel polymerization is demonstrated for fabricating transparent poly(methyl methacrylate) (PMMA)-ZnO quantum dot (QD)-hybrid materials in bulk dimension. ne transparent PMMA-ZnO QD hybrid materials exhibit enhanced UV-shielding effects in the entire UV range, even at concentrations as low as 0.02 wt %.
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| 8. |
- Li, Shanghua, et al.
(författare)
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Fabrication of transparent polymer-inorganic hybrid material
- 2005
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Ingår i: Materials Research Society Symposium Proceedings. - : Springer Science and Business Media LLC. - 9781558998308 ; , s. 190-194
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Konferensbidrag (refereegranskat)abstract
- Polymer-inorganic hybrid materials composed of polymethyl methacrylate (PMMA) and zinc compounds were prepared by sol-gel in-situ transition polymerization of zinc complex in PMMA matrix. Zinc acetate dihydrate dissolved in ethanol was used as the inorganic precursor. Monoethanolamine (MEA) acted as a complexing agent to control the hydrolysis of zinc acetate to produce a zinc compound network, and then PMMA, formed in-situ through a radical polymerization, were chemically bonded to the forming zinc compound network to realize a hybrid material. Transparent homogenous hybrid materials with slight colours from pink to yellow were fabricated by varying the composition. TEM, FT-IR were employed to investigate structural and physical properties. The UV-shielding effect was evaluated by UV-VIS. The low content of zinc (around 0.02 wt%) and the fine particle size rendered it visibly transparent and capable of greatly attenuating UV radiation in the full UV range.
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| 9. |
- Namjou, Bahram, et al.
(författare)
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High-density genotyping of STAT4 reveals multiple haplotypic associations with systemic lupus erythematosus in different racial groups
- 2009
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 60:4, s. 1085-1095
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Systemic lupus erythematosus (SLE) is the prototypical systemic autoimmune disorder, with complex etiology and a strong genetic component. Recently, gene products involved in the interferon pathway have been under intense investigation in terms of the pathogenesis of SLE. STAT-1 and STAT-4 are transcription factors that play key roles in the interferon and Th1 signaling pathways, making them attractive candidates for involvement in SLE susceptibility. METHODS: Fifty-six single-nucleotide polymorphisms (SNPs) across STAT1 and STAT4 on chromosome 2 were genotyped using the Illumina platform, as part of an extensive association study in a large collection of 9,923 lupus patients and control subjects from different racial groups. DNA samples were obtained from the peripheral blood of patients with SLE and control subjects. Principal components analyses and population-based case-control association analyses were performed, and the P values, false discovery rate q values, and odds ratios with 95% confidence intervals were calculated. RESULTS: We observed strong genetic associations with SLE and multiple SNPs located within STAT4 in different ethnic groups (Fisher's combined P = 7.02 x 10(-25)). In addition to strongly confirming the previously reported association in the third intronic region of this gene, we identified additional haplotypic association across STAT4 and, in particular, a common risk haplotype that is found in multiple racial groups. In contrast, only a relatively weak suggestive association was observed with STAT1, probably due to its proximity to STAT4. CONCLUSION: Our findings indicate that STAT4 is likely to be a crucial component in SLE pathogenesis in multiple racial groups. Knowledge of the functional effects of this association, when they are revealed, might improve our understanding of the disease and provide new therapeutic targets.
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| 10. |
- Qin, Jian, et al.
(författare)
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Thermosensitive nanospheres with a gold layer revealed as low-cytotoxic drug vehicles
- 2005
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 21:20, s. 9346-9351
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the positive effect of a gold layer on cell viability is demonstrated by examining the results given by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfop henyl)-2H-tetrazolium (MTS) assay and two-color cell fluorescence viability (TCCV) assay. These cytotoxicity tests were performed with human cervical adenocarcinoma cells (HeLa cell line) and transformed African green monkey kidney fibroblast cells (Cos-7 cell line). To fabricate the nanostructures as drug vehicles, first, poly((L),(L)-lactidec-co-ethylene glycol) (PLLA-PEG) and poly(N-isopropylacrylamide-co-(D),(D)-lactide) (PNIPAAm-PDLA) were synthesized, and then two kinds of thermosensitive nanospheres comprising "shell-in-shell" structures without a gold layer (PLLA-PEG@PNIPAAm-PDLA) and with a gold layer (Au@PLLA-PEG@PNIPAAmPDLA) were constructed by a modified double-emulsion method (MDEM). Both of them displayed a unique thermosensitive character exhibiting the lower critical solubility temperature (LCST) at 36.7 degrees C which was confirmed by LTV-vis spectroscopy and differential scanning calorimetry (DSC). The release profiles of entrapped bovine serum albumin (BSA) were monitored at 22 and 37 degrees C, respectively, to reveal the thermal dependence on the release rate. In cell viability tests, both PLLA-PEG@PNIPAAm-PDLA and Au@PLLAPEGCd)PNIPAAm-PDLA showed excellent cell viability, and furthermore, Au@PLLA-PEG@PNIPAAmPDLA, particularly at high doses, exhibited more enhanced cell viability than PLLA-PEGCa)PNTPAAm-PDLA. This effect is mainly attributed to the gold layer which binds the protein molecules first and consequently facilitates transmembrane uptake of essential nutrients in the cell media, resulting in favorable cell proliferation.
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