Opportunistic Preventive Maintenance Scheduling Based on Theory of Constraints

Abstract In recent years, to improve system reliability and economy, machine maintenance strategies have been paid more and more intention by researchers. This paper aims to integrate the concept of theory of constraints (TOC) into multi-machine opportunistic maintenance policy. Based on the preventive maintenance algorithm, an improved model containing bottleneck strategy which influences opportunistic maintenance has been developed. By maximizing total cost saving, an optimal maintenance schedule of all machines in a series product line can be obtained. The results of a case study show that this model is valid for planning a comprehensive optimal maintenance schedule. Furthermore, by comparing with other models, this model has been proven to be more effectively especially in series product lines with bottleneck

Cell-free miRNAs may indicate diagnosis and docetaxel sensitivity of tumor cells in malignant effusions

<p>Abstract</p> <p>Background</p> <p>Circulating cell-free microRNAs have been identified as potential cancer biomarkers. However, the existence and the potential application of cell-free miRNAs in effusion samples are still uncertain. In order to explore the potential role of cell-free miRNA in malignant effusions, we selected 22 miRNAs differentially expressed in the serum of lung cancer patients and studied their expression levels in body cavity effusion samples.</p> <p>Methods</p> <p>We measured the expression of 22 miRNAs using qRT-PCR in two samples, which were pooled with 18 malignant and 12 benign effusions, respectively. After discarding 9 lowly expressed miRNAs, a panel of 13 miRNAs were measured in 29 samples (benign n = 11, malignant n = 18). We also carried out a WST-8 test to evaluate the docetaxel sensitivity of tumor cells directly isolated from 15 malignant effusions.</p> <p>Results</p> <p>We compared the miRNA expression levels between benign and malignant effusions using a Mann-Whitney U test and found miR-24, miR-26a and miR-30d were expressed differently between the two groups (<it>P </it>= 0.006, 0.021 and 0.011, respectively). Cells isolated from effusions rich in cell-free miR-152 were more sensitive to docetaxel (r = 0.60, <it>P </it>= 0.016).</p> <p>Conclusions</p> <p>Collectively, our study demonstrated that cell-free miRNAs in the supernatant of effusions may aid in the diagnosis of malignancy and predict chemosensitivity to docetaxel.</p

High-performance Coherent Optical Modulators based on Thin-film Lithium Niobate Platform

The coherent transmission technology using digital signal processing and advanced modulation formats, is bringing networks closer to the theoretical capacity limit of optical fibres, the Shannon limit. The in-phase quadrature electro-optic modulator that encodes information on both the amplitude and the phase of light, is one of the underpinning devices for the coherent transmission technology. Ideally, such modulator should feature low loss, low drive voltage, large bandwidth, low chirp and compact footprint. However, these requirements have been only met on separate occasions. Here, we demonstrate integrated thin-film lithium niobate in-phase/quadrature modulators that fulfil these requirements simultaneously. The presented devices exhibit greatly improved overall performance (half-wave voltage, bandwidth and optical loss) over traditional lithium niobate counterparts, and support modulation data rate up to 320 Gbit s-1. Our devices pave new routes for future high-speed, energy-efficient, and cost-effective communication networks