Rotor fault classification technique and precision analysis with kernel principal component analysis and multi-support vector machines

To solve the diagnosis problem of fault classification for aero-engine vibration over standard during test, a fault diagnosis classification approach based on kernel principal component analysis (KPCA) feature extraction and multi-support vector machines (SVM) is proposed, which extracted the feature of testing cell standard fault samples through exhausting the capability of nonlinear feature extraction of KPCA. By computing inner product kernel functions of original feature space, the vibration signal of rotor is transformed from principal low dimensional feature space to high dimensional feature spaces by this nonlinear map. Then, the nonlinear principal components of original low dimensional space are obtained by performing PCA on the high dimensional feature spaces. During muti-SVM training period, as eigenvectors, the nonlinear principal components are separated into training set and test set, and penalty parameter and kernel function parameter are optimized by adopting genetic optimization algorithm. A high classification accuracy of training set and test set is sustained and over-fitting and under-fitting are avoided. Experiment results indicate that this method has good performance in distinguishing different aero-engine fault mode, and is suitable for fault recognition of a high speed rotor

Acox2 is a regulator of lysine crotonylation that mediates hepatic metabolic homeostasis in mice

Acyl-CoA oxidase 2 (Acox2) is an enzyme involved in peroxisomal bile acid synthesis and branched-chain fatty acid degradation. Acox2 knockout (−/−) mice spontaneously developed liver cancer with marked lymphocytic infiltrate. Tandem-affinity purification coupled with mass spectrometry analysis revealed that Acox2 interacted with methylcrotonoyl-CoA carboxylase followed by co-immunoprecipitation confirmation. Here we reported that non-histone lysine crotonylation (Kcr) levels were downregulated in Acox2 −/− mice livers. Interestingly, Kcr signals were concentrated in the nucleus of tumor cells but mostly located in the cytoplasm of adjacent normal liver cells of Acox2 −/− mice. Quantitative analysis of the global crotonylome further revealed that 54% (27/50) of downregulated non-histone Kcr sites were located in mitochondrial (11/50) and peroxisomal (17/50) enzymes including Ehhadh, Scp2, Hsd17b4, Crot, Etfa, Cpt1a, Eci1/2, Hadha, Etfdh, and Idh2. Subsequent site-directed mutagenesis and transcriptome analysis revealed that Ehhadh K 572 cr might have site-specific regulatory roles by downregulating TOP3B expression that lead to increased DNA damage in vitro. Our findings suggested Acox2 is a regulator of Kcr that might play critical role on hepatic metabolic homeostasis

Analysis on the Key Parameters of Aerospace Microminiaturization Decelerator

A high efficiency special transmission decelerator is designed by scheme design, structural design, optimization design, and return difference analysis and computer simulation. Small teeth difference transmission with the first level bevel gear pair and the second level beveloid gear pair is adopted as the form of transmission in the decelerating system. Great torque and big bending moment are available by transmission ratio formula deduction, force analysis and strength analysis. The particle swarm optimization and the genetic algorithm have been combined and the mutation operator optimization model has been proposed to optimize the design of decelerator. Then the transmission with large transmission ratio, high torque, high power and high precision will be realized in small space. This model has solved the problems of particle swarm optimization in mechanical design. For example, there are more variables, it is constrained and it is easily precocious. This model has provided the theoretical basis for the optimum design of microminiaturization gear system. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.339

The value of applying a melatonin antagonist (Luzindole) in improving the success rate of the bipedal rat scoliosis model

Abstract Background An ideal animal model has always been the key to research the pathogenesis and treatment of adolescent idiopathic scoliosis (AIS), while available methods have obvious disadvantages. The deficiency of melatonin has been proved relating to AIS. In this research, we intended to apply Luzindole, the melatonin antagonist, in bipedal rat model, for the block of combination of melatonin and its receptor, to inhibit the melatonin effect, and then to understand whether this method can effectively improve the scoliosis rate of bipedal rat model, and investigate the role of melatonin in scoliosis. To investigate the feasibility of improving the success rate of bipedal rat scoliosis model via intraperitoneal injection of melatonin antagonist (Luzindole). Methods A total of 60 3-weeks-old Sprague-Dawley rats were included in this study, and were divided into 3 groups (A, B and C). Each group included 20 rats. Osteotomy of the bilateral proximal humerus and proximal tailbone was performed in group A and group B; intraperitoneal injection of Luzindole (0.2 mg/kg) was performed in group A and group C. X-rays were taken before the surgery, 1 month after the surgery, 3 months after the surgery, and 6 months after the surgery, to calculate the Cobb’s angle of the spine (>10° was considered scoliosis). The weight of every rat was also measured at the same time. Rats were euthanized 6 months after surgery to determine the calmodulin level in thrombocytes. Results The rate of scoliosis in group A (14/20) was significantly higher than those in group B (6/20) and group C (0/20) (P < 0.05). The differences in the weights of the 3 groups were non-significant; as were differences in the calmodulin level in thrombocytes. Conclusion The application of the melatonin antagonist of Luzindole can improve the success rate of the bipedal rat scoliosis model. Meanwhile, this study indicates that a decreased melatonin level is not the primary cause of scoliosis, but that it may increase the likelihood and severity of scoliosis

Polarization Switching and Photoinduced Dielectric and Ferroelectric Properties in YMnO₃/La_0.67Sr_0.33MnO₃ Heterostructure

YMnO₃/La_0.67Sr_0.33MnO₃ heterostructure was fabricated on SrTiO₃ (110) substrate by pulse laser deposition technology. The photoinduced resistance is markedly decreased in the low temperature region (20–300 K), especially arresting at the <i>T′</i>_C of o-YMnO₃ (∼30 K), the <i>T′</i>_N of o-YMnO₃ (∼40 K), and the <i>T</i>_N of h-YMnO₃ (∼80 K). The variance tendency of the dielectric constant anomaly near the <i>T′</i>_N of o-YMnO₃ progressively decreases as the frequency increases, while the anomaly near the <i>T</i>_N of h-YMnO₃ is not observed in the same frequency region. Additionally, the dielectric constant is suppressed under photo excitation, and the variation increases with the rise in temperature and frequency. A distinct photoinduced suppression in the ferroelectric hysteresis loops is observed, maybe the trapping of photoinduced electrons to incur the reorientation of domain or increase the leakage current density. The obvious polarization switching in phase and amplitude images are observed when poling at ±8 V DC bias by the piezoresponse force microscopy technique at room temperature

Effect of sperm DNA fragmentation on clinical outcome of frozen-thawed embryo transfer and on blastocyst formation.

During the last decades, many studies have shown the possible influence of sperm DNA fragmentation on assisted reproductive technique outcomes. However, little is known about the impact of sperm DNA fragmentation on the clinical outcome of frozen-thawed embryo transfer (FET) from cycles of conventional in vitro fertilization (IVF) and intra-cytoplasmic sperm injection (ICSI). In the present study, the relationship between sperm DNA fragmentation (SDF) and FET clinical outcomes in IVF and ICSI cycles was analyzed. A total of 1082 FET cycles with cleavage stage embryos (C-FET) (855 from IVF and 227 from ICSI) and 653 frozen-thawed blastocyst transfer cycles (B-FET) (525 from IVF and 128 from ICSI) were included. There was no significant change in clinical pregnancy, biochemical pregnancy and miscarriage rates in the group with a SDF >30% compared with the group with a SDF ≤30% in IVF and ICSI cycles with C-FET or B-FET. Also, there was no significant impact on the FET clinic outcome in IVF and ICSI when different values of SDF (such as 10%, 20%, 25%, 35%, and 40%) were taken as proposed threshold levels. However, the blastulation rates were significantly higher in the SDF ≤30% group in ICSI cycle. Taken together, our data show that sperm DNA fragmentation measured by Sperm Chromatin Dispersion (SCD) test is not associated with clinical outcome of FET in IVF and ICSI. Nonetheless, SDF is related to the blastocyst formation in ICSI cycles