16,010 research outputs found
5-(4-BromoÂanilinomethylÂene)-2,2-dimethyl-1,3-dioxane-4,6-dione
In the title compound, C13H12BrNO4, the dihedral angles between the aminoÂmethylÂene group and the dioxane ring and between the benzyl ring and the aminoÂmethylÂene unit are 7.96 (4) and 12.15 (4)°, respectively. The dioxane ring shows a half-boat conformation, in which the C atom between the dioxane ring O atoms is 0.460 (8) Å out of the plane through the remaining ring atoms. An intraÂmolecular N—H⋯O hydrogen bond may stabilize the planar conformation of the molÂecule. An interÂmolecular C—H⋯O interÂaction is also present
Robust Kalman filter-based dynamic state estimation of natural gas pipeline networks
To obtain the accurate transient states of the big scale natural gas pipeline
networks under the bad data and non-zero mean noises conditions, a robust
Kalman filter-based dynamic state estimation method is proposed using the
linearized gas pipeline transient flow equations in this paper. Firstly, the
dynamic state estimation model is built. Since the gas pipeline transient flow
equations are less than the states, the boundary conditions are used as
supplementary constraints to predict the transient states. To increase the
measurement redundancy, the zero mass flow rate constraints at the sink nodes
are taken as virtual measurements. Secondly, to ensure the stability under bad
data condition, the robust Kalman filter algorithm is proposed by introducing a
time-varying scalar matrix to regulate the measurement error variances
correctly according to the innovation vector at every time step. At last, the
proposed method is applied to a 30-node gas pipeline networks in several kinds
of measurement conditions. The simulation shows that the proposed robust
dynamic state estimation can decrease the effects of bad data and achieve
better estimating results.Comment: Accepted by Mathematical Problems in Engineerin
Genetic heterogeneity of pseudoxanthoma elasticum: the Chinese signature profile of ABCC6 and ENPP1 mutations.
Pseudoxanthoma elasticum (PXE), an autosomal recessive disorder characterized by ectopic mineralization, is caused by mutations in the ABCC6 gene. We examined clinically 29 Chinese PXE patients from unrelated families, so far the largest cohort of Asian PXE patients. In a subset of 22 patients, we sequenced ABCC6 and another candidate gene, ENPP1, and conducted pathogenicity analyses for each variant. We identified a total of 17 distinct mutations in ABCC6, 15 of them being, to our knowledge, previously unreported, including 5 frameshift and 10 missense variants. In addition, a missense mutation in combination with a recurrent nonsense mutation in ENPP1 was discovered in a pediatric PXE case. No cases with p.R1141X or del23-29 mutations, common in Caucasian patient populations, were identified. The 10 missense mutations in ABCC6 were expressed in the mouse liver via hydrodynamic tail-vein injections. One mutant protein showed cytoplasmic accumulation indicating abnormal subcellular trafficking, while the other nine mutants showed correct plasma membrane location. These nine mutations were further investigated for their pathogenicity using a recently developed zebrafish mRNA rescue assay. Minimal rescue of the morpholino-induced phenotype was achieved with eight of the nine mutant human ABCC6 mRNAs tested, implying pathogenicity. This study demonstrates that the Chinese PXE population harbors unique ABCC6 mutations. These genetic data have implications for allele-specific therapy currently being developed for PXE
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