4,127 research outputs found
Dual Newton Proximal Point Algorithm for Solution Paths of the L1-Regularized Logistic Regression
The l1-regularized logistic regression is a widely used statistical model in
data classification. This paper proposes a dual Newton method based proximal
point algorithm (PPDNA) to solve the l1-regularized logistic regression problem
with bias term. The global and local convergence of PPDNA hold under mild
conditions. The computational cost of a semismooth Newton (Ssn) algoithm for
solving subproblems in the PPDNA can be effectively reduced by fully exploiting
the second-order sparsity of the problem. We also design an adaptive sieving
(AS) strategy to generate solution paths for the l1-regularized logistic
regression problem, where each subproblem in the AS strategy is solved by the
PPDNA. This strategy exploits active set constraints to reduce the number of
variables in the problem, thereby speeding up the PPDNA for solving a series of
problems. Numerical experiments demonstrate the superior performance of the
PPDNA in comparison with some state-of-the-art second-order algorithms and the
efficiency of the AS strategy combined with the PPDNA for generating solution
paths
Correlation between periostin and SNCG and esophageal cancer invasion, infiltration and apoptosis
AbstractObjectiveTo investigate the correlation between periostin and SNCG and esophageal cancer invasion, infiltration and apoptosis.MethodsA total of 78 cases esophageal surgical resection specimens were collected, expression of periostin and SNCG in esophageal cancer were detected. Effect of periostin and SNCG in esophageal carcinoma invasion and infiltration was analyzed.ResultsThe upregulated rate of periostin had significant difference in esophageal cancer tissues (39.74%), adjacent tissues (17.86%) and normal tissues (0.00%); The positive expression rates of SNCG had significant difference in esophageal cancer tissues (61.54%), adjacent tissues (32.14%) and normal tissues (1.96%); The upregulated rate of periostin had a significant correlation with lymph node metastasis, adventitia invasion, TNM stage; The positive expression rates of SNCG had a significant correlation with differentiation degree, lymph node metastasis, adventitia invasion, TNM stage; Apoptosis index of the positive of expression of SNCG of esophageal cancer tissue (4.541±2.267) was significantly lower than that of the negative expression (7.316±2.582) (P<0.05).ConclusionsSNCG may play an important role in invasion, infiltration and apoptosis of esophageal cancer and serve as target spots in the targeted therapy of esophageal cancer
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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