The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers, and KRAS mutational status testing has been highlighted in recent years. The most frequent mutations in this gene, point substitutions in co...The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers, and KRAS mutational status testing has been highlighted in recent years. The most frequent mutations in this gene, point substitutions in codons 12 and 13, were validated as negative predictors of response to anti-epidermal growth factor receptor antibodies. Therefore, determining the KRAS mutational status of tumor samples has become an essential tool for managing patients with colorectal cancers. Currently, a variety of detection methods have been established to analyze the mutation status in the key regions of the KRAS gene; however, several challenges remain related to standardized and uniform testing, including the selection of tumor samples, tumor sample processing and optimal testing methods. Moreover, new testing strategies, in combination with the mutation analysis of BRAF , PIK3CA and loss of PTEN proposed by many researchers and pathologists, should be promoted. In addition, we recommend that microsatellite instability, a prognostic factor, be added to the abovementioned concomitant analysis. This review provides an overview of KRAS biology and the recent advances in KRAS mutation testing. This review also addresses other aspects of status testing for determining the appropriate treatment and offers insight into the potential drawbacks of mutational testing.展开更多
Turbot （Scophthalmus maximus） is a flatfish species commercially important for aquaculture. In this study, we generated a microsatellite-enriched genomic DNA library for Scophthalmus rnaxirnus, and then isolated and...Turbot （Scophthalmus maximus） is a flatfish species commercially important for aquaculture. In this study, we generated a microsatellite-enriched genomic DNA library for Scophthalmus rnaxirnus, and then isolated and characterized 45 microsateIIite loci by genotyping 30 individuals. The observed number of alleles ranged from 2 to 19 with an average of 6.24, while the effective number of alleles ranged from 1.30 to 11.11 with an average of 3.66. The expected heterozygosities varied from 0.235 to 0.9254 and polymorphic information content ranged from 0.204 4 to 0.903 3, with an average of 0.622. Twelve loci deviated significantly from Hardy-Weinberg equilibrium, and no significant linkage disequilibrium was observed between any pair of loci after Bonferroni correction. In cross-species amplification, five flatfish species （Paralichthys lethostigma, Verasper rnoseri, platichthys stellatus, Hippoglossoides dubius and Cynoglossus semilaevis） showed at least one polymorphic locus. These polymorphic microsatellite loci should prove useful for population analysis of turbot and other related species.展开更多
A method is presented for near-Earth spacecraft or aviation vehicle's attitude rate estimation by using relative Doppler frequency shift; of the Global Positioning System (GPS) carrier. It comprises two GPS receiv...A method is presented for near-Earth spacecraft or aviation vehicle's attitude rate estimation by using relative Doppler frequency shift; of the Global Positioning System (GPS) carrier. It comprises two GPS receiving antennas, a signal processing circuit and an algorithm. The whole system is relatively simple, the cost and weight, as well as power consumption, are very low.展开更多
The three-axis active attitude control method with a momentum wheel and magnetic coils for a pico-satellite is considered. The designed satellite is a 2.5 kg class satellite stabilized to nadir pointing. The momentum ...The three-axis active attitude control method with a momentum wheel and magnetic coils for a pico-satellite is considered. The designed satellite is a 2.5 kg class satellite stabilized to nadir pointing. The momentum wheel performs a pitch-axis momentum bias, nominally spinning at a particular rate. Three magnetic coils are mounted perpendicularly along the body axis for precise attitude control through the switch control mechanism. Momentum wheel start up control, damping control and attitude acquisition control are considered. Simulation results show that the proposed combined control laws for the pico-satellite is reliable and has an appropriate accuracy under different separation conditions. The proposed strategy to start up the wheel after separation from the launch vehicle shows that its pitch momentum wheel can start up successfully to its nominal speed from rest, and the attitude convergence can be completed within several orbits, depending on separation conditions.展开更多
基金Supported by Science and Technology Commission of Shanghai Municipality, No. 10DJ1400501
文摘The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers, and KRAS mutational status testing has been highlighted in recent years. The most frequent mutations in this gene, point substitutions in codons 12 and 13, were validated as negative predictors of response to anti-epidermal growth factor receptor antibodies. Therefore, determining the KRAS mutational status of tumor samples has become an essential tool for managing patients with colorectal cancers. Currently, a variety of detection methods have been established to analyze the mutation status in the key regions of the KRAS gene; however, several challenges remain related to standardized and uniform testing, including the selection of tumor samples, tumor sample processing and optimal testing methods. Moreover, new testing strategies, in combination with the mutation analysis of BRAF , PIK3CA and loss of PTEN proposed by many researchers and pathologists, should be promoted. In addition, we recommend that microsatellite instability, a prognostic factor, be added to the abovementioned concomitant analysis. This review provides an overview of KRAS biology and the recent advances in KRAS mutation testing. This review also addresses other aspects of status testing for determining the appropriate treatment and offers insight into the potential drawbacks of mutational testing.
基金Supported by the Fund for Modern Agro-Industry Technology Research System (No. nycytx-50)the National Sustainability Plan of China (No. 2006BAD01A12012)+1 种基金the Agriculture Commonwealth Scientific Research Plan (No. nyhyzx07-046)the Yellow Sea Fisheries Research Institute Scientific and Research Fund (No. 2009-ts-11)
文摘Turbot （Scophthalmus maximus） is a flatfish species commercially important for aquaculture. In this study, we generated a microsatellite-enriched genomic DNA library for Scophthalmus rnaxirnus, and then isolated and characterized 45 microsateIIite loci by genotyping 30 individuals. The observed number of alleles ranged from 2 to 19 with an average of 6.24, while the effective number of alleles ranged from 1.30 to 11.11 with an average of 3.66. The expected heterozygosities varied from 0.235 to 0.9254 and polymorphic information content ranged from 0.204 4 to 0.903 3, with an average of 0.622. Twelve loci deviated significantly from Hardy-Weinberg equilibrium, and no significant linkage disequilibrium was observed between any pair of loci after Bonferroni correction. In cross-species amplification, five flatfish species （Paralichthys lethostigma, Verasper rnoseri, platichthys stellatus, Hippoglossoides dubius and Cynoglossus semilaevis） showed at least one polymorphic locus. These polymorphic microsatellite loci should prove useful for population analysis of turbot and other related species.
基金Supported by the National Aeronautics and Space Administration(NASA),Goddard Space Flight Center,USA,under Contract AN13709
文摘A method is presented for near-Earth spacecraft or aviation vehicle's attitude rate estimation by using relative Doppler frequency shift; of the Global Positioning System (GPS) carrier. It comprises two GPS receiving antennas, a signal processing circuit and an algorithm. The whole system is relatively simple, the cost and weight, as well as power consumption, are very low.
基金supported by the Program for New Century Excellent Talents in University (No. NCET-06-0514), Chinathe Postdoctoral Science Foundation of China (Nos. 20081458 and 20080431306)
文摘The three-axis active attitude control method with a momentum wheel and magnetic coils for a pico-satellite is considered. The designed satellite is a 2.5 kg class satellite stabilized to nadir pointing. The momentum wheel performs a pitch-axis momentum bias, nominally spinning at a particular rate. Three magnetic coils are mounted perpendicularly along the body axis for precise attitude control through the switch control mechanism. Momentum wheel start up control, damping control and attitude acquisition control are considered. Simulation results show that the proposed combined control laws for the pico-satellite is reliable and has an appropriate accuracy under different separation conditions. The proposed strategy to start up the wheel after separation from the launch vehicle shows that its pitch momentum wheel can start up successfully to its nominal speed from rest, and the attitude convergence can be completed within several orbits, depending on separation conditions.
