Spatter generation is considered to be a practical problem in the industrial short-circuiting transfer process of gas metal arc welding. Extensive experimental research has been conducted, and some ...novel approaches have been developed to mitigate splatter generation. In this study, a three-dimensional numerical model of the short-circuiting transfer process was constructed, and the behavior of the liquid bridge was analyzed. The accuracy of the model was verified by comparing the calculation results with the results of an experiment on a water bridge. When short-circuiting transfer was performed with an inclined electrode wire, the liquid bridge was deformed in a manner similar to the deformation of an arch, and it subsequently broke up. Thereafter, the bridge droplet detached as a spatter from the wire tip. This behavior was caused by the difference in the magnetic flux density between the two sides of the liquid bridge. The balance between the surface tension and the electromagnetic force is important for the spatter generation. The inclination angle of the electrode wire, the short-circuiting current, and the surface tension of the molten metal are the most important factors that influence spatter generation.
Identification of differentially expressed genes (DEGs) under different experimental conditions is an important task in many microarray studies. However, choosing which method to use for a particular ...application is problematic because its performance depends on the evaluation metric, the dataset, and so on. In addition, when using the Affymetrix GeneChip(R) system, researchers must select a preprocessing algorithm from a number of competing algorithms such as MAS, RMA, and DFW, for obtaining expression-level measurements. To achieve optimal performance for detecting DEGs, a suitable combination of gene selection method and preprocessing algorithm needs to be selected for a given probe-level dataset.
We introduce a new fold-change (FC)-based method, the weighted average difference method (WAD), for ranking DEGs. It uses the average difference and relative average signal intensity so that highly expressed genes are highly ranked on the average for the different conditions. The idea is based on our observation that known or potential marker genes (or proteins) tend to have high expression levels. We compared WAD with seven other methods; average difference (AD), FC, rank products (RP), moderated t statistic (modT), significance analysis of microarrays (samT), shrinkage t statistic (shrinkT), and intensity-based moderated t statistic (ibmT). The evaluation was performed using a total of 38 different binary (two-class) probe-level datasets: two artificial "spike-in" datasets and 36 real experimental datasets. The results indicate that WAD outperforms the other methods when sensitivity and specificity are considered simultaneously: the area under the receiver operating characteristic curve for WAD was the highest on average for the 38 datasets. The gene ranking for WAD was also the most consistent when subsets of top-ranked genes produced from three different preprocessed data (MAS, RMA, and DFW) were compared. Overall, WAD performed the best for MAS-preprocessed data and the FC-based methods (AD, WAD, FC, or RP) performed well for RMA and DFW-preprocessed data.
WAD is a promising alternative to existing methods for ranking DEGs with two classes. Its high performance should increase researchers' confidence in microarray analyses.
The aim of the present study was to evaluate the natural course of acute incomplete stent apposition (ISA) after second-generation everolimus-eluting stent (EES) when compared with first-generation ...sirolimus-eluting stent (SES) by using optical coherence tomography (OCT).
From the OCT substudy of the RESET trial, we identified 77 patients (EES = 38 and SES = 39) who successfully underwent serial OCT examination at post-stenting and 8-12-month follow-up. The presence of ISA was assessed in the OCT images, and ISA distance was measured from the centre of the strut blooming to the adjacent lumen border. Incomplete stent apposition was observed in all EES and SES at post-stenting, and it was persistent in 26% of EES and 38% of SES at 8-12-month follow-up. Maximum ISA distance was significantly decreased during the follow-up period in both EES (315 ± 94-110 ± 165 μm, P < 0.001) and SES (308 ± 119-143 ± 195 μm, P < 0.001). Receiver-operating curve analysis identified that the best cut-off value of OCT-estimated ISA distance at post-stenting for predicting late-persistent ISA at 8-12-month follow-up in EES and SES was >355 and >285 μm, respectively.
The second-generation EES showed better healing of acute ISA in comparison with the first-generation SES. Optical coherence tomography can predict late-persistent ISA after DES implantation and provide useful information to optimize PCI.
Recent progress in genome-wide expression analysis has identified hundreds of circadian genes not only in the suprachiasmatic nucleus (the mammalian master clock) but also in peripheral tissues, such ...as heart, liver and kidney of mammals. Glucocorticoid is thought to be a circadian time cue for mammalian peripheral clocks. To identify the genes of which the circadian expression is regulated by endogenous glucocorticoids, we performed DNA microarray analysis using hepatic RNA from adrenalectomized (ADX) and sham-operated mice. We identified 169 genes that fluctuated between day and night in the livers of the sham-operated mice. Among these, 100 lost circadian rhythmicity in ADX mice. These included the genes for key enzymes of liver metabolic functions, such as glucokinase, HMG-CoA reductase and glucose-6-phosphatase. The circadian expression of Lpin1, FKBP51 and S-adenosyl methionine decarboxylase was also abolished in the ADX mice. On the other hand, although the circadian expression of clock or clock-related genes, such as mPer2, DBP, E4BP4, mDec1, Usp2 and Wee1 remained almost totally intact in the liver of ADX mice, it was extremely damped in homozygous Clock mutant mice. The present findings suggested that one type of hepatic circadian genes in mice is transcriptionally regulated by core components of the circadian clock, such as CLOCK and BMAL1, and that the other depends on the adrenal gland.
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