| 1. |
- Abazov, V. M., et al.
(författare)
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The upgraded DO detector
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 565:2, s. 463-537
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Tidskriftsartikel (refereegranskat)abstract
- The DO experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid -argon calorimeters and central muon detector, remaining from Run 1, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DO.
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| 2. |
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| 3. |
- Bruzzi, M, et al.
(författare)
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Radiation-hard semiconductor detectors for SuperLHC
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 541:1-2, s. 189-201
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Tidskriftsartikel (refereegranskat)abstract
- An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 1035 cm-2 s-1 has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 1016cm-2. The CERN-RD50 project "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Float Zone silicon), the improvement of present detector designs and the understanding of the microscopic defects causing the degradation of the irradiated detectors. The latest advancements within the RD50 collaboration on radiation hard semiconductor detectors will be reviewed and discussed in this work.
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| 4. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 5. |
- Ballantyne, C., et al.
(författare)
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Collaborative meta-analysis of individual participant data from observational studies of Lp-PLA(2) and cardiovascular diseases
- 2007
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Ingår i: European Journal of Cardiovascular Prevention & Rehabilitation. - 1741-8275. ; 14:1, s. 41344-41344
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Forskningsöversikt (refereegranskat)abstract
- Background A large number of observational epidemiological studies have reported generally positive associations' between circulating mass and activity levels of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and the risk of cardiovascular diseases. Few studies have been large enough to provide reliable estimates in different circumstances, such as in different subgroups (e.g., by age group, sex, or smoking status) or at different Lp-PLA2 levels. Moreover, most published studies have related disease risk only to baseline values of Lp-PLA(2) markers (which can lead to substantial underestimation of any risk relationships because of within-person variability over time) and have used different approaches to adjustment for possible confounding factors. Objectives By combination of data from individual participants from all relevant observational studies in a systematic,meta-analysis, with correction for regression dilution (using available data on serial measurements of Lp-PLA(2)), the Lp-PLA(2) Studies Collaboration will aim to characterize more precisely than has previously been possible the strength and shape of the age and sex-specific associations of plasma Lp-PLA(2) with coronary heart disease (and, where data are sufficient with other vascular diseases, such as ischaemic stroke). It will also help to determine to what extent such associations are independent of possible confounding factors and to explore potential sources of heterogeneity among studies, such as those related to assay methods and study design. It is anticipated that the present collaboration will serve as a framework to investigate related questions on Lp-PLA(2) and cardiovascular outcomes. Methods A central database is being established containing data on circulating Lp-PLA(2) values, sex and other potential confounding factors, age at baseline Lp-PLA(2) Measurement, age at event or at last follow-up, major vascular morbidity and cause-specific mortality. Information about any repeat measurements of Lp-PLA2 and potential confounding factors has been sought to allow adjustment for possible confounding and correction for regression dilution. The analyses will involve age-specific regression models. Synthesis of the available observational studies of Lp-PLA(2) will yield information on a total of about 15 000 cardiovascular disease endpoints.
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| 6. |
- Ballantyne, C., et al.
(författare)
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Collaborative meta-analysis of individual participant data from observational studies of Lp-PLA2 and cardiovascular diseases
- 2007
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Ingår i: European Journal of Cardiovascular Prevention & Rehabilitation. - : Oxford University Press (OUP). - 1741-8267 .- 1741-8275 .- 2047-4873. ; 14:1, s. 3-11
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Forskningsöversikt (refereegranskat)abstract
- BACKGROUND: A large number of observational epidemiological studies have reported generally positive associations between circulating mass and activity levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular diseases. Few studies have been large enough to provide reliable estimates in different circumstances, such as in different subgroups (e.g., by age group, sex, or smoking status) or at different Lp-PLA2 levels. Moreover, most published studies have related disease risk only to baseline values of Lp-PLA2 markers (which can lead to substantial underestimation of any risk relationships because of within-person variability over time) and have used different approaches to adjustment for possible confounding factors. OBJECTIVES: By combination of data from individual participants from all relevant observational studies in a systematic 'meta-analysis', with correction for regression dilution (using available data on serial measurements of Lp-PLA2), the Lp-PLA2 Studies Collaboration will aim to characterize more precisely than has previously been possible the strength and shape of the age and sex-specific associations of plasma Lp-PLA2 with coronary heart disease (and, where data are sufficient, with other vascular diseases, such as ischaemic stroke). It will also help to determine to what extent such associations are independent of possible confounding factors and to explore potential sources of heterogeneity among studies, such as those related to assay methods and study design. It is anticipated that the present collaboration will serve as a framework to investigate related questions on Lp-PLA2 and cardiovascular outcomes. METHODS: A central database is being established containing data on circulating Lp-PLA2 values, sex and other potential confounding factors, age at baseline Lp-PLA2 measurement, age at event or at last follow-up, major vascular morbidity and cause-specific mortality. Information about any repeat measurements of Lp-PLA2 and potential confounding factors has been sought to allow adjustment for possible confounding and correction for regression dilution. The analyses will involve age-specific regression models. Synthesis of the available observational studies of Lp-PLA2 will yield information on a total of about 15 000 cardiovascular disease endpoints.
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| 7. |
- Mikkelsen, Tarjei S, et al.
(författare)
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Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7141, s. 167-177
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Tidskriftsartikel (refereegranskat)abstract
- We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian ('marsupial') species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation.
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| 8. |
- Tångring, I., et al.
(författare)
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Strong 1.3-1.6 mu m light emission from metamorphic InGaAs quantum wells on GaAs
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 86:17, s. 171902-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate strong 1.3-1.6 mu m photoluminescence (PL) from InGaAs quantum wells (QWs) grown on alloy graded InGaAs buffer layers on GaAs by molecular beam epitaxy. The epistructures show quite smooth surfaces with an average surface roughness less than 2 nm. The PL intensity is comparable with those from InAs quantum dots and InGaAs QWs on GaAs, and InGaAsP QWs on InP at similar wavelengths, but stronger than those from GaInNAs QWs (at least 10 times higher at around 1.5-1.6 mu m). The excellent optical quality implies that the metamorphic approach could be a promising alternative to GaInNAs(Sb) QWs for 1.55 mu m lasers on GaAs.
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| 9. |
- Berlijn, Sonja M., et al.
(författare)
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Laboratory Tests and Web Based Surveillance to Determine the Ice- and Snow Performance of Insulators
- 2007
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Ingår i: IEEE Transactions on Dielectrics and Electrical Insulation, Special Issue on Flashover of Ice or Snow-Covered Insulators. ; 14:6, s. 1373-1380, 2007
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Tidskriftsartikel (refereegranskat)abstract
- To be able to determine, verify and monitor the ice- and snow performance of different insulation solutions, laboratory test methods and an on-site, on-line web based surveillance system are needed. The method for determining the ice performance in laboratory conditions, Ice Progressive Stress (IPS) method, is described in this paper. Further it is described how to use the results of this type of test to estimate statistically the performance of complete overhead line equipped by different insulators. To verify the laboratory ice- and snow test method, to get an idea about the type and number of ice and snow events actually occurring in service and to get more information about ice and snow phenomena in real life an on-site on-line web based surveillance system was designed and built. This sophisticated system, including the automatic image analysis and used statistical tools is described in this paper. Besides the description of the laboratory test method and the surveillance system, service experience, pictures and interesting results obtained so far are also presented.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Mwaba, M.G., et al.
(författare)
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A State of the Art for Magnetic Based Fouling Mitigation Methods
- 2005
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Ingår i: International Journal of Heat Exchangers. ; 6:2, s. 235-266
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Tidskriftsartikel (refereegranskat)abstract
- Fouling mitigation, using magnets, is a technology that promises so much but still remains a mystery. It has been reported that magnets have been successful in controlling scaling, especially that due to calcium carbonate. In this article, the current state of magnetic based fouling mitigation strategies as found in the literature is presented. Experimental results and modeling efforts of magnetic influence on the scaling process are evaluated. The motivation for the evaluation is to identify key issues that require additional research. Evaluation of literature shows that there is an incomplete understanding of how exactly magnetic fields influence fluid systems. Significant knowledge gaps regarding effects of magnetic fields on (a) fluid flow, (b) elementary processes of scaling (nucleation, crystal growth and morphology). It is also evident that there is no clear agreement regarding the right conditions under which magnetic fields are effective in mitigating against fouling. Therefore, it is suggested that priority be placed on fundamental studies of the influence of magnetic fields on properties of the fluid systems under given conditions.
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| 14. |
- Sacco, R. L., et al.
(författare)
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Aspirin and extended-release dipyridamole versus clopidogrel for recurrent stroke
- 2008
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Ingår i: New England Journal of Medicine. - Boston : Massachusetts medical society. - 1533-4406 .- 0028-4793. ; 359:12, s. 1238-51
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recurrent stroke is a frequent, disabling event after ischemic stroke. This study compared the efficacy and safety of two antiplatelet regimens--aspirin plus extended-release dipyridamole (ASA-ERDP) versus clopidogrel. METHODS: In this double-blind, 2-by-2 factorial trial, we randomly assigned patients to receive 25 mg of aspirin plus 200 mg of extended-release dipyridamole twice daily or to receive 75 mg of clopidogrel daily. The primary outcome was first recurrence of stroke. The secondary outcome was a composite of stroke, myocardial infarction, or death from vascular causes. Sequential statistical testing of noninferiority (margin of 1.075), followed by superiority testing, was planned. RESULTS: A total of 20,332 patients were followed for a mean of 2.5 years. Recurrent stroke occurred in 916 patients (9.0%) receiving ASA-ERDP and in 898 patients (8.8%) receiving clopidogrel (hazard ratio, 1.01; 95% confidence interval [CI], 0.92 to 1.11). The secondary outcome occurred in 1333 patients (13.1%) in each group (hazard ratio for ASA-ERDP, 0.99; 95% CI, 0.92 to 1.07). There were more major hemorrhagic events among ASA-ERDP recipients (419 [4.1%]) than among clopidogrel recipients (365 [3.6%]) (hazard ratio, 1.15; 95% CI, 1.00 to 1.32), including intracranial hemorrhage (hazard ratio, 1.42; 95% CI, 1.11 to 1.83). The net risk of recurrent stroke or major hemorrhagic event was similar in the two groups (1194 ASA-ERDP recipients [11.7%], vs. 1156 clopidogrel recipients [11.4%]; hazard ratio, 1.03; 95% CI, 0.95 to 1.11). CONCLUSIONS: The trial did not meet the predefined criteria for noninferiority but showed similar rates of recurrent stroke with ASA-ERDP and with clopidogrel. There is no evidence that either of the two treatments was superior to the other in the prevention of recurrent stroke. (ClinicalTrials.gov number, NCT00153062.)
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| 15. |
- Shaffer, David R, et al.
(författare)
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Circulating tumor cell analysis in patients with progressive castration-resistant prostate cancer
- 2007
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 13:7, s. 2023-2029
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To better direct targeted therapies to the patients with tumors that express the target, there is an urgent need for blood-based assays that provide expression information on a consistent basis in real time with minimal patient discomfort. We aimed to use immunomagnetic-capture technology to isolate and analyze circulating tumor cells (CTC) from small volumes of peripheral blood of patients with advanced prostate cancer. EXPERIMENTAL DESIGN: Blood was collected from 63 patients with metastatic prostate cancer. CTCs were isolated by the Cell Search system, which uses antibodies to epithelial cell adhesion marker and immunomagnetic capture. CTCs were defined as nucleated cells positive for cytokeratins and negative for CD45. Captured cells were analyzed by immunofluorescence, Papanicolau staining, and fluorescence in situ hybridization. RESULTS: Most patients (65%) had 5 or more CTCs per 7.5 mL blood sample. Cell counts were consistent between laboratories (c = 0.99) and did not change significantly over 72 or 96 h of storage before processing (c = 0.99). Their identity as prostate cancer cells was confirmed by conventional cytologic analysis. Molecular profiling, including analysis of epidermal growth factor receptor (EGFR) expression, chromosome ploidy, and androgen receptor (AR) gene amplification, was possible for all prostate cancer patients with >or=5 CTCs. CONCLUSIONS: The analysis of cancer-related alterations at the DNA and protein level from CTCs is feasible in a hospital-based clinical laboratory. The alterations observed in EGFR and AR suggest that the methodology may have a role in clinical decision making.
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| 16. |
- Yusuf, S., et al.
(författare)
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Telmisartan to prevent recurrent stroke and cardiovascular events
- 2008
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Ingår i: New England Journal of Medicine. - : Massachusetts medical society. - 1533-4406 .- 0028-4793. ; 359:12, s. 1225-37
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prolonged lowering of blood pressure after a stroke reduces the risk of recurrent stroke. In addition, inhibition of the renin-angiotensin system in high-risk patients reduces the rate of subsequent cardiovascular events, including stroke. However, the effect of lowering of blood pressure with a renin-angiotensin system inhibitor soon after a stroke has not been clearly established. We evaluated the effects of therapy with an angiotensin-receptor blocker, telmisartan, initiated early after a stroke. METHODS: In a multicenter trial involving 20,332 patients who recently had an ischemic stroke, we randomly assigned 10,146 to receive telmisartan (80 mg daily) and 10,186 to receive placebo. The primary outcome was recurrent stroke. Secondary outcomes were major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure) and new-onset diabetes. RESULTS: The median interval from stroke to randomization was 15 days. During a mean follow-up of 2.5 years, the mean blood pressure was 3.8/2.0 mm Hg lower in the telmisartan group than in the placebo group. A total of 880 patients (8.7%) in the telmisartan group and 934 patients (9.2%) in the placebo group had a subsequent stroke (hazard ratio in the telmisartan group, 0.95; 95% confidence interval [CI], 0.86 to 1.04; P=0.23). Major cardiovascular events occurred in 1367 patients (13.5%) in the telmisartan group and 1463 patients (14.4%) in the placebo group (hazard ratio, 0.94; 95% CI, 0.87 to 1.01; P=0.11). New-onset diabetes occurred in 1.7% of the telmisartan group and 2.1% of the placebo group (hazard ratio, 0.82; 95% CI, 0.65 to 1.04; P=0.10). CONCLUSIONS: Therapy with telmisartan initiated soon after an ischemic stroke and continued for 2.5 years did not significantly lower the rate of recurrent stroke, major cardiovascular events, or diabetes. (ClinicalTrials.gov number, NCT00153062.)
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| 17. |
- Zhao, Qingxiang, 1962-, et al.
(författare)
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Optical properties of GaInNAs/GaAs quantum well structures
- 2007
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:10, s. 4423-4426
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Tidskriftsartikel (refereegranskat)abstract
- The radiative recombination in GaInNAs/GaAs quantum well structures was investigated by low temperature optical spectroscopy. In the temperature region, below 100 K, we found that the observed transition energies strongly depend on the excitation intensity and the temperature, which is indicative of carrier localization. The degree of carrier localization depends on the In-concentration but is not significantly influenced by the N-concentration when the N-concentration exceeds 1.6%. Photoluminescence studies indicate that the degree of the carrier localization decreases with increasing In-concentration at a constant N-concentration. In addition, the experimental results show that carrier localization is strongly correlated to deep level emission. Through post-growth thermal treatment at 650 °C both carrier localization and deep level emission can be eliminated.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Gu, B., et al.
(författare)
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Low-cost high-performance fiber-optic pH sensor based on thin-core fiber modal interferometer
- 2009
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Ingår i: Optics Express. - 1094-4087. ; 17:25, s. 22296-22302
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Tidskriftsartikel (refereegranskat)abstract
- A new fiber-optic pH sensor based on a thin-core fiber modal interferometer with electrostatic self-assembled nanocoating is presented. After inserting a segment of thin-core fiber into a standard single-mode fiber, high-order cladding modes are excited and interfere with the core mode to form an in-fiber modal interferometer. The side surface of the sensor is then deposited with poly(allylamine hydrochloride) and poly(acrylic acid) nanocoating by electrostatic self-assembly technique. A fast and linear response is obtained in either acid or alkali solution (in the pH range 2.5 to 10) with resolution of 0.013 pH unit.
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| 24. |
- Gu, G, et al.
(författare)
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Estrogen protects primary osteocytes against glucocorticoid-induced apoptosis
- 2005
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Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 10:3, s. 583-595
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Tidskriftsartikel (refereegranskat)abstract
- Glucocorticoid-induced osteoporosis may be at least in part due to the increased apoptosis of osteocytes. To study the role of osteocyte apoptosis in glucocorticoid-induced osteoporosis, we isolated primary osteocytes from murine calvaria for the analysis of the effects of dexamethasone in in vitro culture. The cells were identified by morphology, cytochemical staining, immunocytochemical staining and mRNA expression of phosphate-regulating gene with homology to endopeptidases on the X chromosome (PHEX) and sclerosteosis/van Buchem disease gene (SOST). We found that dexamethasone induced osteocyte apoptosis in a dose-dependent manner. A glucocorticoid receptor antagonist, mifepristone (RU486), suppressed dexamethasone-Induced osteocyte apoptosis, suggesting that it was mediated by glucocorticoid receptor. Immunocytochemical stainings showed that glucocorticoid receptors are present in primary osteocytes, and they were translocated to nuclei after the exposure to dexamethasone. Addition of estrogen prevented glucocorticoid receptor translocation into nuclei. Corresponding antiapoptotic effects in primary osteocytes were also seen after the pretreatment of primary osteocytes with a picomolar concentration of estrogen. The pure antiestrogen ICI 182,780 inhibited estrogen effect on apoptosis induced by dexamethasone. These data suggest that glucocorticoid receptors play an important role in glucocorticoid-induced osteocyte apoptosis. Most importantly, estrogen has a protective effect against osteocyte apoptosis. To conclude, the mechanism of glucocorticoid-induced osteoporosis may be due to the apoptosis of osteocytes, which can be opposed by estrogen.
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| 25. |
- Gu, Irene Yu-Hua, 1953, et al.
(författare)
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Automatic Surveillance and Analysis of Snow and Ice Coverage on Electrical Insulators of Power Transmission Lines
- 2008
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1611-3349 .- 0302-9743. - 9783642023446 ; 5337, s. 368-379
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Konferensbidrag (refereegranskat)abstract
- One of the large problems for electrical power delivery through power lines in the Northern countries is when snow or ice accumulates on electrical insulators. This could lead to snow or ice-induced outages and voltage collapse, causing huge economic loss. This paper proposes a novel real-time automatic surveillance and image analysis system for detecting and estimating the snow and ice coverage on electric insulators using images captured from an outdoor 420 kV power transmission line. In addition, the swing angle of insulators is estimated, as large swing angles due to wind cause short circuits. Hybrid techniques by combining histogram, edges, boundaries and cross-correlations are employed for handling a broad range of scenarios caused by changing weather and lighting conditions. Experiments have been conducted on the captured images over several month periods. Results have shown that the proposed system has provided valuable estimation results. For image pixels related to snows on the insulator, the current system has yielded an average detection rate of 93% for good quality images, and 67.6% for images containing large amount of poor quality ones, and the corresponding average false alarm ranges from 9% to 18.1%. Further improvement may be achieved by using video-based analysis and improved camera settings.
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