After analyzing the shortcomings of current feature extraction and fault diagnosis technologies, a new approach based on wavelet packet decomposition (WPD) and empirical mode decomposition (EMD) are ...combined to extract fault feature frequency and neural network for rotating machinery early fault diagnosis is proposed. Acquisition signals with fault frequency feature are decomposed into a series of narrow bandwidth using WPD method for de-noising, then, the intrinsic mode functions (IMFs), which usually denoted the features of corresponding frequency bandwidth can be obtained by applying EMD method. Thus, the component of IMF with signal feature can be separated from all IMFs and the energy moment of IMFs is proposed as eigenvector to effectively express the failure feature. The classical three layers BP neural network model taking the fault feature frequency as target input of neural network, the 5 spectral bandwidth energy of vibration signal spectrum as characteristic parameter, and the 10 types of representative rotor fault as output can be established to identify the fault pattern of a machine. Lastly, the fault identification model of rotating machinery with rotor lateral early crack based on BP neural network is taken as an example. The results show that the proposed method can effectively get the signal feature to diagnose the occurrence of early fault of rotating machinery.
► In this study a new fault diagnosis method based on the WPD–EMD and BP network is proposed. ► EMD energy is introduced to reflect the actual work condition and the fault pattern of rotating machinery. ► BP network served as a classifier to identify the work condition of rotating machinery. ► The method is useful for extracting the feature for weak signals and diagnosing the early fault.
CHARMM: The biomolecular simulation program Brooks, B.R; Brooks, C.L. III; Mackerell, A.D. Jr ...
Journal of computational chemistry,
30 July 2009, Volume:
30, Issue:
10
Journal Article
Peer reviewed
Open access
CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on ...molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.
Emerging evidences suggest that necrosis is programmed and is one of the main forms of cell death in the pathological process in cardiac diseases. Long noncoding RNAs (lncRNAs) are emerging as new ...players in gene regulation. However, it is not yet clear whether lncRNAs can regulate necrosis in cardiomyocytes. Here, we report that a long noncoding RNA, named necrosis-related factor (NRF), regulates cardiomyocytes necrosis by targeting miR-873 and RIPK1 (receptor-interacting serine/threonine-protein kinase 1)/RIPK3 (receptor-interacting serine/threonine-protein kinase 3). Our results show that RIPK1 and RIPK3 participate in H2O2-induced cardiomyocytes necrosis. miR-873 suppresses the translation of RIPK1/RIPK3 and inhibits RIPK1/RIPK3-mediated necrotic cell death in cardiomyocytes. miR-873 reduces myocardial infarct size upon ischemia/reperfusion (I/R) injury in the animal model. In exploring the molecular mechanism by which miR-873 expression is regulated, we identify NRF as an endogenous sponge RNA and repress miR-873 expression. NRF directly binds to miR-873 and regulates RIPK1/RIPK3 expression and necrosis. Knockdown of NRF antagonizes necrosis in cardiomyocytes and reduces necrosis and myocardial infarction upon I/R injury. Further, we identify that p53 transcriptionally activates NRF expression. P53 regulates cardiomyocytes necrosis and myocardial I/R injury through NRF and miR-873.Our results identify a novel mechanism involving NRF and miR-873 in regulating programmed necrosis in the heart and suggest a potential therapeutic avenue for cardiovascular diseases.
The cBioPortal for Cancer Genomics (http://cbioportal.org) provides a Web resource for exploring, visualizing, and analyzing multidimensional cancer genomics data. The portal reduces molecular ...profiling data from cancer tissues and cell lines into readily understandable genetic, epigenetic, gene expression, and proteomic events. The query interface combined with customized data storage enables researchers to interactively explore genetic alterations across samples, genes, and pathways and, when available in the underlying data, to link these to clinical outcomes. The portal provides graphical summaries of gene-level data from multiple platforms, network visualization and analysis, survival analysis, patient-centric queries, and software programmatic access. The intuitive Web interface of the portal makes complex cancer genomics profiles accessible to researchers and clinicians without requiring bioinformatics expertise, thus facilitating biological discoveries. Here, we provide a practical guide to the analysis and visualization features of the cBioPortal for Cancer Genomics.
The origin and history of the Amerasia basin are long‐running debates, which hinder our knowledge of the Mesozoic tectonic configurations and geodynamic processes in the Arctic. This lack of ...knowledge is due in part to the paucity of accurate magnetic data in the ice‐covered basin. Here, we identify the crustal age of the Canada Basin, a major part of the Amerasia Basin, through high‐resolution deep‐tow and sea‐surface magnetic data. The best fit of the four pairs of magnetic lineations revealed by the high‐resolution magnetic data is 139.5–128.6 Ma (or 142.4–132.8 Ma, depending on the geomagnetic polarity timescale). The crustal age provides crucial constraints on the evolution of the circum‐Arctic tectonic features and generally supports the hypothesis that the opening of the Amerasia Basin is related to the subductions during the closure of the South Anyui Ocean.
Plain Language Summary
The Amerasia Basin of the Arctic Ocean is one of the last major puzzles of the plate reconstructions, due to the lack of age knowledge. The identification of magnetic anomalies is the routine method of acquiring the age of oceanic crust, yet floating ice in the basin makes it difficult to obtain magnetic data. We collected deep‐tow magnetic data in the basin by lowering a magnetic sensor to a depth of ~2,000 m, which provides high‐resolution data and avoids floating ice. The identified magnetic lineations indicate the Amerasia Basin opened at 139.5–128.6 Ma (or 142.4–132.8 Ma, depending on the geomagnetic polarity timescale). The contemporaneous closure of the ancient South Anyui Ocean (~1,000 km in the south) may have provided space for the opening of the Amerasia Basin. This interpretation then generally supports the existing hypothesis that the opening of the Amerasia Basin is associated with the subduction process in the South Anyui Ocean. Nevertheless, a more sophisticated geodynamical model is still needed.
Key Points
High‐resolution deep‐tow and sea‐surface magnetic data in the ice‐covered Canada Basin of the Arctic Ocean are presented
The crustal age of the Canada Basin is 139.5–128.6 Ma (142.4–132.8 Ma), with a spreading rate of ~32 (38) mm/year
The opening of the Canada Basin was roughly contemporaneous with the closure of the ancient South Anyui Ocean
Background and purpose:
Perivascular adipose tissue (PVAT) attenuates vascular contraction, but the mechanisms remain largely unknown. The possible involvement of endothelium (E) and hydrogen ...peroxide (H2O2) was investigated.
Experimental approach:
Aortic rings from Wistar rats were prepared with both PVAT and E intact (PVAT+E+), with either PVAT or E removed (PVAT‐E+, or PVAT+E‐), or with both removed (PVAT‐E‐) for functional studies. Nitric oxide (NO) production was measured.
Key results:
Contraction to phenylephrine and 5‐HT respectively was highest in PVAT‐E‐, lowest in PVAT+E+, and intermediate in PVAT+E‐ or PVAT‐E+. In bioassay experiments, transferring bathing solution incubated with a PVAT+ ring (donor) to a PVAT‐ ring (recipient) induced relaxation in the recipient. This relaxation was abolished by E removal, NO synthase inhibition, scavenging of NO, high extracellular K+, or blockade of calcium‐dependent K+ channels (KCa). The solution stimulated NO production in isolated endothelial cells and in PVAT‐E+ rings. In E‐ rings, the contraction to phenylephrine of PVAT+ rings but not PVAT‐ rings was enhanced by catalase or soluble guanylyl cyclase (sGC) inhibitor, but reduced by superoxide dismutase and tiron. In PVAT‐E‐ rings, H2O2 attenuated phenylephrine‐induced contraction. This effect was counteracted by sGC inhibition. NO donor and H2O2 exhibited additive inhibition of the contraction to phenylephrine in PVAT‐E‐ rings.
Conclusion:
PVAT exerts its anti‐contractile effects through two distinct mechanisms: (1) by releasing a transferable relaxing factor which induces endothelium‐dependent relaxation through NO release and subsequent KCa channel activation, and (2) by an endothelium‐independent mechanism involving H2O2 and subsequent activation of sGC.
British Journal of Pharmacology (2007) 151, 323–331; doi:10.1038/sj.bjp.0707228
Remotely sensed imagery is ideally used to monitor and detect land cover changes that occur frequently in urban and peri-urban areas as a consequence of incessant urbanization. It is a lengthy ...process to convert satellite imagery into land cover map using the existing methods of manual interpretation and parametric image classification digitally. In this paper we propose a new method based on Normalized Difference Built-up Index (NDBI) to automate the process of mapping built-up areas. It takes advantage of the unique spectral response of built-up areas and other land covers. Built-up areas are effectively mapped through arithmetic manipulation of re-coded Normalized Difference Vegetation Index (NDVI) and NDBI images derived from TM imagery. The devised NDBI method was applied to map urban land in the city of Nanjing, eastern China. The mapped results at an accuracy of 92.6% indicate that it can be used to fulfil the mapping objective reliably. Compared with the maximum likelihood classification method, the proposed NDBI is able to serve as a worthwhile alternative for quickly and objectively mapping built-up areas.
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