| 1. |
- Arvela, Riina K, et al.
(författare)
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A reassessment of the transition-metal free suzuki-type coupling methodology.
- 2005
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 70:1, s. 161-168
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Tidskriftsartikel (refereegranskat)abstract
- We present here a reassessment of our transition-metal free Suzuki-type coupling protocol. We believe that, although the reaction can be run without the need for addition of a metal catalyst, palladium contaminants down to a level of 50 ppb found in commercially available sodium carbonate are responsible for the generation of the biaryl rather than, as previously suggested, an alternative non-palladium-mediated pathway. We present a revised methodology for Suzuki couplings using ultralow palladium concentrations for use with aryl and vinyl boronic acids and discuss the effects of the purity of the boronic acid on the reaction.
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| 2. |
- Grutter, M., et al.
(författare)
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SO2 emissions from Popocatépetl volcano: emission rates and plume imaging using optical remote sensing techniques
- 2008
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 8, s. 6655-6663
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Tidskriftsartikel (refereegranskat)abstract
- Sulfur dioxide emissions from the Popocatépetl volcano in central Mexico were measured during the MILAGRO field campaign in March 2006. A stationary scanning DOAS (Differential Optical Absorption Spectrometer) was used to monitor the SO2 emissions from the volcano and the results were compared with traverses done with a COSPEC from the ground and a DOAS instrument on board an ultra-light aircraft. Daytime evolutions as well as day-to-day variation of the SO2 emissions are reported. A value of 2.45±1.39 Gg/day of SO2 is reported from all the daily averages obtained during the month of March 2006, with large variation in maximum and minimum daily averages of 5.97 and 0.56 Gg/day, respectively. The large short-term fluctuations in the SO2 emissions obtained could be confirmed through 2-D visualizations of the SO2 plume measured with a scanning imaging infrared spectrometer. This instrument, based on the passive detection of thermal radiation from the volcanic gas and analysis with FTIR spectrometry, is used for the first time for plume visualization of a specific volcanic gas. A 48-h forward trajectory analysis indicates that the volcanic plume was predominantly directed towards the Puebla/Tlaxcala region (63%), followed by the Mexico City and Cuernavaca/Cuautla regions with 19 and 18% occurrences, respectively. 25% of the modeled trajectories going towards the Puebla region reached altitudes lower than 4000 m a.s.l. but all trajectories remained over this altitude for the other two regions.
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| 3. |
- Linga Reddy, M. V. Prasad, et al.
(författare)
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Genetic association of IRF5 with SLE in Mexicans : higher frequency of the risk haplotype and its homozygozity than Europeans
- 2007
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 0340-6717 .- 1432-1203. ; 121:6, s. 721-727
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Tidskriftsartikel (refereegranskat)abstract
- The IRF5 gene was found to be strongly associated with SLE. We identified two functional polymorphisms and recently an insertion/deletion together with a tag SNP defining the risk haplotype in individuals of European ancestry. We now analyzed sets of Mexican patients with SLE. Three polymorphisms in the IRF5 gene were genotyped in two sets of Mexican individuals with SLE and controls as well as in families including a set of pediatric SLE patients. A set of healthy Mexican Indians was also typed. Genetic association with SLE was found for all three polymorphisms. The genetic association was very strong in the case–control analysis in both sets (for SNP rs2070197, combined P = 1.26 × 10−21) and in families (combined P = 0.000004). Compared to healthy individuals with European ancestry, the frequency of the risk haplotype in healthy Mexican individuals was significantly higher and even higher in the healthy Mexican Indian group. Further, a much higher frequency of the risk haplotype and of individual homozygote for it was found among Mexican SLE patients. The significantly higher frequency of homozygote individuals for the risk haplotype among Mexican SLE patients could be the result of genetic admixture, and suggests the possibility that IRF5 could be involved in the more active disease and organ involvement known to occur among Mexican SLE patients.
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| 4. |
- Matsson, Hans, et al.
(författare)
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Alpha-cardiac actin mutations produce atrial septal defects.
- 2008
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 17:2, s. 256-65
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Tidskriftsartikel (refereegranskat)abstract
- Atrial septal defect (ASD) is one of the most frequent congenital heart defects (CHDs) with a variable phenotypic effect depending on the size of the septal shunt. We identified two pedigrees comprising 20 members segregating isolated autosomal dominant secundum ASD. By genetic mapping, we identified the gene-encoding alpha-cardiac actin (ACTC1), which is essential for cardiac contraction, as the likely candidate. A mutation screen of the coding regions of ACTC1 revealed a founder mutation predicting an M123V substitution in affected individuals of both pedigrees. Functional analysis of ACTC1 with an M123V substitution shows a reduced affinity for myosin, but with retained actomyosin motor properties. We also screened 408 sporadic patients with CHDs and identified a case with ASD and a 17-bp deletion in ACTC1 predicting a non-functional protein. Morpholino (MO) knockdown of ACTC1 in chick embryos produces delayed looping and reduced atrial septa, supporting a developmental role for this protein. The combined results indicate, for the first time, that ACTC1 mutations or reduced ACTC1 levels may lead to ASD without signs of cardiomyopathy.
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| 5. |
- Rocca, J. J., et al.
(författare)
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High brightness table-top soft x-ray lasers at high repetition rate : injection-seeding of solid target plasma amplifiers and other developments - art. no. 670202
- 2007
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Ingår i: SOFT X-RAY LASERS AND APPLICATIONS VII. - : SPIE. ; , s. 70202-70202
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Konferensbidrag (refereegranskat)abstract
- We have recently demonstrated high repetition rate tabletop lasers operating at wavelengths as short as 10.9 rim based on collisional transient excitation of ions in plasmas created by laser heating of solid targets. As a further step in the development of these lasers into very high brightness and fully coherent soft x-ray sources, we have demonstrated injection seeding of the amplifiers with high harmonic seed pulses. We report results of an experiment in which a 32.6 rim Ne-like Ti amplifier was used to amplify a seed pulse from the 25(th) harmonic of Ti:Sapphire into the gain saturation regime. Simultaneous amplification of the 27(th) harmonic at 30.1 nm was also observed. The seeded soft x-ray laser beam was measured to approach full spatial coherence. We have demonstrated that this scheme is scalable to shorter wavelengths and that is capable of producing extremely bright soft x-ray laser pulse with essentially full coherence.
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