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- Abdesselam, A., et al.
(author)
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The ATLAS semiconductor tracker end-cap module
- 2007
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 575:3, s. 353-389
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Journal article (peer-reviewed)abstract
- The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker. (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip 3.3 mu s buffer. The highest anticipated dose after 10 years operation is 1.4x10(14) cm(-2) in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area similar to 70 cm(2), each having 2 x 768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X-0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e(-) equivalent noise charge (ENC) rising to only 1800e(-) ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide flex read-out circuit and the ABCD3TA read-out ASICs. Finally, the accuracy of module assembly must not compromise the 16 mu m (r phi) resolution perpendicular to the strip directions or 580 mu m radial resolution coming from the 40 mrad front-back stereo angle. A total of 2210 modules were built to the tight tolerances and specifications required for the SCT. This was 234 more than the 1976 required and represents a yield of 93%. The component flow was at times tight, but the module production rate of 40-50 per week was maintained despite this. The distributed production was not found to be a major logistical problem and it allowed additional flexibility to take advantage of where the effort was available, including any spare capacity, for building the end-cap modules. The collaboration that produced the ATLAS SCT end-cap modules kept in close contact at all times so that the effects of shortages or stoppages at different sites could be rapidly resolved.
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- Wilson, J. A., et al.
(author)
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The optical links of the ATLAS SemiConductor tracker
- 2007
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In: Journal of Instrumentation. - 1748-0221. ; 2, s. 1-28
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Journal article (peer-reviewed)abstract
- Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical link requirements are reviewed, with particular emphasis on the very demanding environment at the LHC. The on-detector components have to operate in high radiation levels for 10 years, with no maintenance, and there are very strict requirements on power consumption, material and space. A novel concept for the packaging of the on-detector optoelectronics has been developed to meet these requirements. The system architecture, including its redundancy features, is explained and the critical on-detector components are described. The results of the extensive Quality Assurance performed during all steps of the assembly are discussed.
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- Birney, Ewan, et al.
(author)
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Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project
- 2007
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7146, s. 799-816
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Journal article (peer-reviewed)abstract
- We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
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- Kuimova, M. K., et al.
(author)
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Determination of the triplet state energies of a series of conjugated porphyrin oligomers
- 2007
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In: Photochemical and Photobiological Sciences. - : Springer Science and Business Media LLC. - 1474-9092 .- 1474-905X. ; 6:6, s. 675-682
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Journal article (peer-reviewed)abstract
- We report a systematic study of the photophysical parameters relevant to photodynamic therapy (PDT) by a new type of sensitizers, conjugated porphyrin oligomers. Due to the strong nonlinear properties of oligomers containing 2, 4 and 8 porphyrin units, these molecules are attractive candidates for PDT via multiphoton excitation. The triplet state energy levels for all molecules have been determined by the triplet quenching method, phosphorescence measurements and DFT calculations. We find that the triplet energies of all the oligomers are sufficient to generate singlet oxygen, > 94 kJ mol(-1). However, low singlet oxygen quantum yields are observed for the tetramer and the octamer, as compared to the conjugated dimer and monomeric porphyrin, reflecting the decrease in triplet yield. Thus the conjugated porphyrin dimer is the most promising core structure for PDT applications via multiphoton excitation.
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5. |
- Andel, R, et al.
(author)
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Complexity of primary lifetime occupation and cognition in advanced old age
- 2007
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In: Journal of aging and health. - : SAGE Publications. - 0898-2643 .- 1552-6887. ; 19:3, s. 397-415
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Journal article (peer-reviewed)abstract
- Objectives: The authors explored the association between complexity of primary lifetime occupation and cognition in older adulthood. Method: The study included 386 participants from the Swedish Panel Study of Living Conditions of the Oldest Old, a nationally representative sample aged 77 years or older. The authors examined complexity of work with data, people, and things in relation to cognitive functioning, measured with a shortened version of Mini-Mental State Examination (MMSE) and cognitive impairment based on MMSE score cutoff. Results: Complexity of work with data and people were associated with better MMSE scores, controlling for age, sex, childhood socioeconomic status, and education. The association between complexity of work with data and MMSE remained statistically significant when adult occupational status was substituted for education as a covariate. Discussion: Complexity of primary lifetime occupation may be reflected in cognitive functioning even in advanced old age. This effect may be independent of education or occupational status.
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- von Haartman, M., et al.
(author)
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Impact of strain and channel orientation on the low-frequency noise performance of Si n- and pMOSFETs
- 2007
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In: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 51:5, s. 771-777
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Journal article (peer-reviewed)abstract
- Mobility and low-frequency (LF) noise were studied in tensile strained Si n- and pMOSFETs fabricated on relaxed SiGe virtual substrates. Both the impact of the channel orientation ((110) or (100) on (100) Si) and the tensile strain were carefully investigated. Two types of virtual substrates were used; a thin relaxed SiGe layer (20% Ge) and a thick one (27% Ge). The strained Si nMOSFETs fabricated on the thin substrate showed similar LF noise level as in the reference devices, whereas the thick substrate caused severely increased LF noise in the nMOSFETs. The latter was linked to the higher Ge concentration and explained by possible misfit dislocations and increased defect densities, likely resulting from strain relaxation caused by ion implantation damage. On the other hand, considerably lower LF noise was achieved in the pMOSFETs on the thick SiGe. The channel orientation was not found to have a significant influence on the LF noise performance in any of the studied devices.
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- Lee, Jung Eun, et al.
(author)
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Alcohol intake and renal cell cancer in a pooled analysis of 12 prospective studies
- 2007
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In: Journal of the National Cancer Institute. - Brigham & Womens Hosp, Channing Lab, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Boston, MA 02115 USA. Harvard Univ, Sch Publ Hlth, Dept Nutr, Boston, MA USA. Harvard Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA. Harvard Univ, Sch Publ Hlth, Dept Biostat, Boston, MA USA. Karolinska Inst, Dept Med Epidemiol & Biostat, Div Nutr Epidemiol, Natl Inst Environm Med, Stockholm, Sweden. NCI, Div Canc Epidemiol & Genet, Dept Hlth & Hlth Serv, NIH, Bethesda, MD USA. Univ So Calif, Dept Prevent Med, Los Angeles, CA USA. Univ So Calif, Norriss Comprehens Canc Ctr, Los Angeles, CA USA. Maastricht Univ, Dept Epidemiol, Nutr & Toxicol Res Inst, Maastricht, Netherlands. Univ Minnesota, Sch Publ Hlth, Dept Epidemiol & Community Hlth, Minneapolis, MN USA. SUNY Buffalo, Dept Social & Prevent Med, Buffalo, NY 14260 USA. No Calif Canc Ctr, Fremont, CA USA. Amer Canc Soc, Epidemiol & Surveillance Res, Atlanta, GA USA. Univ Toronto, Dept Publ Hlth Sci, Toronto, ON, Canada. Mayo Clin, Coll Med, Dept Urol, Jacksonville, FL USA. Albert Einstein Coll Med, Dept Epidemiol & Populat Hlth, Bronx, NY 10467 USA. Natl Publ Hlth Inst, Dept Hlth Promot & Chron Dis Prevent, Helsinki, Finland. : OXFORD UNIV PRESS INC. - 0027-8874 .- 1460-2105. ; 99:10, s. 801-810
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Journal article (peer-reviewed)abstract
- Background The association between alcohol intake and risk of renal cell cancer has been inconsistent in case-control studies. An inverse association between alcohol intake and risk of renal cell cancer has been suggested in a few prospective studies, but each of these studies included a small number of cases. Methods We performed a pooled analysis of 12 prospective studies that included 530469 women and 229575 men with maximum follow-up times of 7-20 years. All participants had completed a validated food-frequency questionnaire at baseline. Using the primary data from each study, the study-specific relative risks (RRs) for renal cell cancer were calculated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided. Results A total of 1430 (711 women and 719 men) cases of incident renal cell cancer were identified. The study-standardized incidence rates of renal cell cancer were 23 per 100000 person-years among nondrinkers and 15 per 100000 person-years among those who drank 15 g/day or more of alcohol. Compared with non-drinking, alcohol consumption (>= 15 g/day, equivalent to slightly more than one alcoholic drink per day) was associated with a decreased risk of renal cell cancer (pooled multivariable RR = 0.72, 95% confidence interval = 0.60 to 0.86; P-trend <.001); statistically significant inverse trends with increasing intake were seen in both women and men. No difference by sex was observed (P-heterogeneity = .89). Associations between alcohol intake and renal cell cancer were not statistically different across alcoholic beverage type (beer versus wine versus liquor) (P = .40). Conclusion Moderate alcohol consumption was associated with a lower risk of renal cell cancer among both women and men in this pooled analysis.
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