Research on the Reliability Tolerance Analysis Method of Electromagnetic Relay in Aerospace

AbstractElectromagnetic relay in aerospace is one of the main electronic components in aerospace electronic systems for information transfer, control and power distribution, and its reliability will influence the reliability of the whole aerospace electronic systems. Reliability design is the key technique of electromagnetic relay reliability engineering. This paper synthetically analyzes the present reliability design methods, and presents the reliability tolerance analyzing mathematic models of electromagnetic force basing on orthogonal design, mechanical spring force basing on probability statistics theory, and matching characteristics of electromagnetic force and mechanical spring force basing on method of stress-strength interference. Some instructive conclusions are draw by researching on the reliability tolerance of some type electromagnetic relay in aerospace

Epithelial protein lost in neoplasm-α (EPLIN-α) is a potential prognostic marker for the progression of epithelial ovarian cancer

Epithelial protein lost in neoplasm-α (EPLIN-α) is a cytoskeletal protein whose expression is often lost or is aberrant in cancerous cells and tissues and whose loss is believed to be involved in aggressive phenotypes. This study examined this molecule in human epithelial ovarian tissues and investigated the cellular impact of EPLIN-α on ovarian cancer cells (EOC), SKOV3 and COV504. The expression of EPLIN-α in human ovarian tissues and EOC was assessed at both the mRNA and protein levels using reverse transcription-PCR (RT-PCR) and immunohistochemistry, respectively. In vitro assays for cellular matrix adhesion and migration (confirmed by an electrical cell substrate impedance sensing (ECIS) based method), invasion and cell growth were employed in order to assess the biological influence of EPLIN-α expression on EOC cells. Immunohistochemical analysis of ovarian cancer samples demonstrated that only a small number expressed EPLIN-α protein. Downregulation of EPLIN-α protein in EOC cell lines increased the growth, invasion, adhesion and migration in vitro. This EPLIN-α downregulation may have a prognostic value. From these data, we conclude that downregulation of EPLIN-α may be associated with poorer patient prognosis, and that this molecule appears to play a tumour suppressor role by inhibition of EOC growth and migration

Existence and Uniqueness of Periodic Solutions for a Class of Nonlinear Equations with p-Laplacian-Like Operators

We investigate the following nonlinear equations with p-Laplacian-like operators (φ(x′(t)))′+f(x(t))x′(t)+g(x(t))=e(t): some criteria to guarantee the existence and uniqueness of periodic solutions of the above equation are given by using Mawhin's continuation theorem. Our results are new and extend some recent results due to Liu (B. Liu, Existence and uniqueness of periodic solutions for a kind of Lienard type p-Laplacian equation, Nonlinear Analysis TMA, 69, 724–729, 2008)

Generating accurate negative samples for landslide susceptibility mapping: A combined self-organizing-map and one-class SVM method

The accuracy of data-driven landslide susceptibility mapping (LSM) is closely affected by the quality of non-landslide samples. This research proposes a method combining a self-organizing-map (SOM) and a one-class SVM (SOM-OCSVM) to generate more reasonable non-landslide samples. We designed two steps: first, a random selection, a SOM network, a one class SVM model, and a SOM-OCSVM model were used to generate non-landslide sample datasets. Second, four machine learning models (MLs)—namely logistic regression (LRG), multilayer perceptron (MLP), support vector machine (SVM), and random forest (RF)—were used to verify the effects of four non-landslide sample datasets on LSM. From the region along the Sichuan-Tibet Highway, we selected 11 conditioning factors and 1186 investigated landslides to perform the aforementioned experiments. The results show that the SOM-OCSVM method achieves the highest AUC (>0.94) and minimum standard deviation (<0.081) compared with other methods. Moreover, RF achieves the best performance in different datasets compared with other ML models. The aforementioned results prove that the proposed method can enhance the performance of ML models to produce more reliable LSM

The Effect of Vinpocetine on Human Cytochrome P450 Isoenzymes by Using a Cocktail Method

Vinpocetine is a derivative of the alkaloid vincamine, which had been prescribed for chronic cerebral vascular ischemia and acute ischemic stroke or used as a dietary supplement for its several different mechanisms of biological activities. However, information on the cytochrome P450 (CYP) enzyme-mediated drug metabolism has not been previously studied. The present study was performed to investigate the effects of vinpocetine on CYPs activity, and cocktail method was used, respectively. To evaluate the effects of vinpocetine on the activity of human CYP3A4, CYP2C9, CYP2C19, CYP2D6, and CYP2E1, human liver microsomes were utilized to incubate with the mixed CYPs probe substrates and the target components. The results indicate that vinpocetine exhibited weak inhibitory effect on the CYP2C9, where the IC50 value is 68.96 μM, whereas the IC50 values for CYP3A4, CYP2C19, CYP2D6, and CYP2E1 were all over range of 100 μM, which showed that vinpocetine had no apparent inhibitory effects on these CYPs. In conclusion, the results indicated that drugs metabolized by CYP2C9 coadministrated with vinpocetine may require attention or dose adjustment

SPC-P1: a pathogenicity-associated prophage of Salmonella paratyphi C

<p>Abstract</p> <p>Background</p> <p><it>Salmonella paratyphi </it>C is one of the few human-adapted pathogens along with <it>S. typhi, S. paratyphi </it>A and <it>S. paratyphi </it>B that cause typhoid, but it is not clear whether these bacteria cause the disease by the same or different pathogenic mechanisms. Notably, these typhoid agents have distinct sets of large genomic insertions, which may encode different pathogenicity factors. Previously we identified a novel prophage, SPC-P1, in <it>S. paratyphi </it>C RKS4594 and wondered whether it might be involved in pathogenicity of the bacteria.</p> <p>Results</p> <p>We analyzed the sequence of SPC-P1 and found that it is an inducible phage with an overall G+C content of 47.24%, similar to that of most <it>Salmonella </it>phages such as P22 and ST64T but significantly lower than the 52.16% average of the RKS4594 chromosome. Electron microscopy showed short-tailed phage particles very similar to the lambdoid phage CUS-3. To evaluate its roles in pathogenicity, we lysogenized <it>S. paratyphi </it>C strain CN13/87, which did not have this prophage, and infected mice with the lysogenized CN13/87. Compared to the phage-free wild type CN13/87, the lysogenized CN13/87 exhibited significantly increased virulence and caused multi-organ damages in mice at considerably lower infection doses.</p> <p>Conclusions</p> <p>SPC-P1 contributes pathogenicity to <it>S. paratyphi </it>C in animal infection models, so it is possible that this prophage is involved in typhoid pathogenesis in humans. Genetic and functional analyses of SPC-P1 may facilitate the study of pathogenic evolution of the extant typhoid agents, providing particular help in elucidating the pathogenic determinants of the typhoid agents.</p

Structural and functional analyses of disease-causing missense mutations in Bloom syndrome protein

Bloom syndrome (BS) is an autosomal recessive disorder characterized by genomic instability and the early development of many types of cancer. Missense mutations have been identified in the BLM gene (encoding a RecQ helicase) in affected individuals, but the molecular mechanism and the structural basis of the effects of these mutations remain to be elucidated. We analysed five disease-causing missense mutations that are localized in the BLM helicase core region: Q672R, I841T, C878R, G891E and C901Y. The disease-causing mutants had low ATPase and helicase activities but their ATP binding abilities were normal, except for Q672, whose ATP binding activity was lower than that of the intact BLM helicase. Mutants C878R, mapping near motif IV, and G891E and C901Y, mapping in motif IV, displayed severe DNA-binding defects. We used molecular modelling to analyse these mutations. Our work provides insights into the molecular basis of BLM pathology, and reveals structural elements implicated in coupling DNA binding to ATP hydrolysis and DNA unwinding. Our findings will help to explain the mechanism underlying BLM catalysis and interpreting new BLM causing mutations identified in the future

TMRT observations of 26 pulsars at 8.6 GHz

Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities and pulse width parameters of these pulsars are estimated. For eleven pulsars these are the first high-frequency observations and for a further four, our observations have a better signal-to-noise ratio than previous observations. For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed profiles. A comparison of 19 profiles with those at other frequencies shows that in nine cases the separation between the outmost leading and trailing components decreases with frequency, roughly in agreement with radius-to-frequency mapping, whereas in the other ten the separation is nearly constant. Different spectral indices of profile components lead to the variation of integrated pulse profile shapes with frequency. In seven pulsars with multi-component profiles, the spectral indices of the central components are steeper than those of the outer components. For the 12 pulsars with multi-component profiles in the high-frequency sample, we estimate the core width using gaussian fitting and discuss the width-period relationship.Comment: 33 pages, 49 figures, 5 Tables; accepted by Ap