MicroRNAs (miRNAs) have great potential serving as tumor biomarkers and therapeutic targets. As the rapid development of high-throughput experimental technology, gene expression experiments have become more and more specialized and diversified. The complex data structure has brought great challenge for the identification of biomarkers. In the meantime, current statistical and machine learning methods for detecting biomarkers have the problem of low reliability and biased criteria. This study aims to select combinatorial miRNA biomarkers, which have higher sensitivity and specificity than single-gene biomarkers. In order to avoid exhaustive search and redundant information, miRNAs are firstly clustered, then the combinations of representative cluster members are assessed as potential biomarkers. Both the criteria for the partition of clusters and selection of representative members are based on Fisher linear discriminant analysis (FDA). The FDA-based criterion has been demonstrated to be superior to three other criteria in selecting representative members, and also good at refining clusters. In the comparison with eight common feature selection methods, this clustering-based method performs the best with regard to the discriminative ability of selected biomarkers. Our experimental results demonstrate that the clustering-based method can identify microRNA combinatorial biomarkers with high accuracy and efficiency. Our method and data are available to the public upon request.

Magnetic levitation vehicle (maglev) is a promising candidate for high-speed transportation with features like low pollution and power loss. And the maglev performances are further enhanced by introducing the high-temperature superconducting (HTS) technology to the maglev. In this paper, a 7.55-kW small-scale HTS linear synchronous motor (LSM) is designed as a preparatory research of the propulsion system for the future high-speed maglev. Different from those in a permanent magnet (PM) LSM, the primary and secondary parts are especially designed for an HTS LSM according to the design flow. Performances are analyzed including the comparison between the HTS LSM and the PM LSM. Under the same electromagnetic gap of 10 mm, the maximum propulsive force of the HTS LSM is 1510 N, which is ∼50% larger than that of the PM LSM though the commercial PMs with the strongest remnant field of 1.45 T (N52) are selected and arranged in a Halbach array. And the field waveform of HTS secondary is also more sinusoidal with lower total harmonic distortion. Overall, the HTS LSM performs better than the PM LSM, and the design results can provide possible references for the future high-speed maglev.

Superconducting magnetic levitation (maglev) is de-veloping rapidly in recent decades. Compared to traditional rail-ways, superconducting maglev is superior in aspects such as faster speed, less pollution and safer operation. The development of sec-ond generation (2G) high-temperature Superconducting (HTS) wires, which have higher in-field critical current density and me-chanical strength, has also improved the design performance of the superconducting maglev. This paper presents design and optimiza-tion processes of no-insulation magnets using 2G HTS wires for a prototype of linear propulsion system in the maglev. According to the design results, one of the coils in the magnets are manufactured for routine test including IC measurement and maglev-related tests including field quality comparison, charging characters like delay and loss, over-MMF test and mechanical vibration test simulating the running conditions of the maglev. The coil has no degradations or obvious changes of performances after the tests. And the test re-sults meet the expected requirements of the prototype.

Direct current carrying Type II superconductors present a dc electric field under external perpendicular AC magnetic field, commonly referred to as “dynamic resistance effect”. Two kinds of AC losses occur in this situation: dynamic loss due to the interaction between the DC current and moving fluxons, and magnetization loss due to shielding current caused by the external AC magnetic fields. In general, HTS coated conductors have one substrate layer, which can be non-magnetic (Hastelloy) or magnetic (NiW). In this paper, we present the impacts of the magnetic substrate and their strength of ferromagnetism on dynamic loss and magnetization loss by using a finite-element method model based on H -formulation. This work reveals that the magnetic substrate layer does influence the dynamic loss and magnetization loss of HTS coated conductors. The dynamic loss is reduced by the adjacent magnetic substrate in the low field region and is increase in the high field region. The magnetization loss is reduced significantly by the magnetic substrate. This work will help choose HTS coated conductors with different substrate layers in different applications.