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Super model for viruses The nematode Caenorhabditis elegans is an ideal model for the study of many aspects of cell biology, including the hot topic of RNA interference (RNAi). But there was a problem in using the worm to study antiviral RNAi responses: C. elegans seemed not to support viral replication. But now the insect pathogen Flock house virus and the mammalian pathogen vesicular stomatitis virus are both shown to infect the worm, and to provoke a strong RNAi-based antiviral defence. So this important genetic model is now available for the study of host–virus interactions, and the antiviral effect of RNAi. The worm Caenorhabditis elegans is a model system for studying many aspects of biology, including host responses to bacterial pathogens 1 , 2 , but it is not known to support replication of any virus. Plants and insects encode multiple Dicer enzymes that recognize distinct precursors of small RNAs and may act cooperatively 3 , 4 , 5 , 6 , 7 . However, it is not known whether the single Dicer of worms and mammals is able to initiate the small RNA-guided RNA interference (RNAi) antiviral immunity as occurs in plants 8 and insects 9 . Here we show complete replication of the Flock house virus (FHV) bipartite, plus-strand RNA genome in C. elegans . We show that FHV replication in C. elegans triggers potent antiviral silencing that requires RDE-1, an Argonaute protein 10 , 11 essential for RNAi mediated by small interfering RNAs (siRNAs) but not by microRNAs. This immunity system is capable of rapid virus clearance in the absence of FHV B2 protein, which acts as a broad-spectrum RNAi inhibitor 9 , 12 upstream of rde-1 by targeting the siRNA precursor. This work establishes a C. elegans model for genetic studies of animal virus–host interactions and indicates that mammals might use a siRNA pathway as an antiviral response.

A regulator of the protein phosphatase 2A (PP2A), α4, has been implicated in a variety of functions that regulate many cellular processes. To explore the role of α4 in human cell transformation and tumorigenesis, we show that α4 is highly expressed in human cells transformed by chemical carcinogens including benzo( a )pyrene, aflatoxin B 1 , N -methyl- N ′-nitro- N -nitrosoguanidine, nickel sulfate and in several hepatic and lung cancer cell lines. In addition, overexpression of α4 was detected in 87.5% (74/80) of primary hepatocellular carcinomas, 84.0% (21/25) of primary lung cancers and 81.8% (9/11) of primary breast cancers, indicating that α4 is ubiquitously highly expressed in human cancer. Functional studies revealed that elevated α4 expression results in an increase in cell proliferation, promotion of cell survival and decreased PP2A-attributable activity. Importantly, ectopic expression of α4 permits non-transformed human embryonic kidney cells (HEKTER) and L02R cells to form tumors in immunodeficient mice. Furthermore, we show that the highly expressed α4 in transformed cells or human tumors is not regulated by DNA hypomethylation. A microRNA, miR-34b, that suppresses the expression of α4 through specific binding to the 3′-untranslated region of α4 is downregulated in transformed or human lung tumors. Taken together, these observations identify that α4 possesses an oncogenic function. Reduction of PP2A activity due to an enhanced α4–PP2A interaction contributes directly to chemical carcinogen-induced tumorigenesis.

This paper proposes an advanced encryption standard (AES) cryptosystem based on memristive neural network. A memristive chaotic neural network is constructed by using the nonlinear characteristics of a memristor. A chaotic sequence, which is sensitive to initial values and has good random characteristics, is used as the initial key of AES grouping to realize \"one-time-one-secret\" dynamic encryption. In addition, the Rivest-Shamir-Adleman (RSA) algorithm is applied to encrypt the initial values of the parameters of the memristive neural network. The results show that the proposed algorithm has higher security, a larger key space and stronger robustness than conventional AES. The proposed algorithm can effectively resist initial key-fixed and exhaustive attacks. Furthermore, the impact of device variability on the memristive neural network is analyzed, and a circuit architecture is proposed.

The magnetic and compressive properties of the ternary Ni40.6Fe36.4Ti23 eutectic alloys solidified under electromagnetic levitation condition were investigated. An undercooling range from 32 to 141 K was achieved, and a ternary eutectic consisting of a fibrous Fe2Ti phase and lamellar γ-Fe(Ni) + Ni3Ti phases formed. In the ternary eutectic, the γ-Fe(Ni) and Ni3Ti phases kept cooperative growth, while the Fe2Ti phase grew either cooperatively with these two phases or sometimes independently. Theoretical calculations showed that there existed a vertical flow field and temperature gradient in the center of the levitated alloy droplet, contributing to the directional growth behavior of eutectic grain. The growth velocity of primary Ni3Ti dendrite increased by 2.4 times, while that of ternary eutectic increased by 77% as undercooling rose, and consequently, the microstructures were significantly refined. The temperature stability of coercivity and residual magnetization below ambient temperature was improved once alloy undercooling reached 128 K, ascribed to the enhancement of the exchange coupling effect between the magnetic domains inside refined grains. The fracture strain of the ternary eutectic alloy increased with undercooling because microcrack propagation was further hindered and the plastic deformation was more homogeneous. Meanwhile, the fracture was dominated by transgranular (TG) mode at an undercooling of 132 K because the bonding force of grain boundaries became stronger.

The microstructure and mechanical properties of the extruded Mg–2Gd–1.2Y–0.5Zn (at.%) alloy with Mn or Zr addition were investigated. The results show that Zr addition refines the microstructure of the homogenized alloy more efficiently and facilitates the dissolution of the secondary phases in comparison with Mn addition. After extrusion at 400 °C, both Mn and Zr added alloys exhibit bimodal microstructure comprising fine dynamically recrystallized (DRXed) grains with random orientations as well as coarse unDRXed grains with strong 101¯0//ED fiber texture. Thin long period stacking ordered phases and γ precipitates distribute in the unDRXed grains and nano-sized β phases mainly pin at the DRXed grain boundaries. While the coarse initial grain size of homogenized Mn added alloy leads to its lower DRX ratio and stronger texture intensity after extrusion with respect to Zr added alloy. High strength, moderate ductility and improved yield anisotropy are obtained in both extruded alloys. The Mn added alloy exhibits higher strength with ultimate tensile strength of 437 MPa, 0.2% tensile proof stress of 381 MPa but lower elongation to failure of 4.7% than Zr added alloy, which is mainly due to the lower DRX ratio of Mn added alloy.

Green leaf volatiles (GLVs) have been reported to play an important role in the host-locating behavior of several folivores that feed on angiosperms. However, next to nothing is known about how the green leafhopper, Empoasca vitis, chooses suitable host plants and whether it detects differing emission levels of GLV components among genetically different tea varieties. Here we found that the constitutive transcript level of the tea hydroperoxide lyase (HPL) gene CsiHPL1, and the amounts of (Z)-3-hexenyl acetate and of total GLV components are significantly higher in tea varieties that are susceptible to E. vitis (Enbiao (EB) and Banzhuyuan (BZY)) than in varieties that are resistant to E. vitis (Changxingzisun (CX) and Juyan (JY)). Moreover, the results of a Y-tube olfactometer bioassay and an oviposition preference assay suggest that (Z)-3-hexenyl acetate and (Z)-3-hexenol offer host and oviposition cues for E. vitis female adults. Taken together, the two GLV components, (Z)-3-hexenol and especially (Z)-3-hexenyl acetate, provide a plausible mechanism by which tea green leafhoppers distinguish among resistant and susceptible varieties. Future research should be carried out to obtain the threshold of the above indices and then assess their reasonableness. The development of practical detection indices would greatly improve our ability to screen and develop tea varieties that are resistant to E. vitis.

Lily is universally known for its large, showy, fragrant flower, and Sorbonne is one of the best-selling Oriental hybrid lily cultivars. To accelerate lily breeding for more robust, attractive, and disease-resistant cultivars, it is essential to introduce molecular marker-assisted breeding. However, the enormous genome size, of around 36 Gb, is an obstacle for genomic information mining. We sequenced and assembled a mixture of six tissues of Lilium ‘Sorbonne’ using Illumina HiSeq2000. A set of 49,991 Unigenes with an average length of 673 bp was produced, and 36,093 sequences were annotated against public protein databases. The number of transcripts with GO annotation was 26,212, with 55 subcategories. Virus transcripts were detected, even though in very small amounts. From the 49,991 Unigenes, 1,853 SSRs were identified. The most common repeat motifs were trinucleotide and dinucleotide with GA/CT and GGC/CCG the most common repeats. Fifty-seven EST-SSR markers were validated in 32 lily genotypes with a mean PIC value of 0.55. A 57-primer-based dendrogram was in accordance with the genetic background derived from complex breeding practices and previous studies. Thirty out of the 57 SSR-derived Unigenes were of function-known genes. Subsequently, a comprehensive hybrid assembly was generated, merging the current transcriptome with two more lily transcriptomes available on the public database. The distribution of gene ontology for the three sets of assembly and mismatch/gap uncovering for Unigenes before and after hybrid assembly was analyzed. Our data are an extensive complement to the lily genome database, which will benefit genetic research and candidate gene mining.

STAT1 has a key role in exerting the antiproliferative and proapoptotic effects of interferon (IFN)-α on tumors, and its defects in expression is associated with IFN-α resistance. In this study we want to investigate whether aspirin can improve the antitumor efficiency of IFN-α on hepatocellular carcinoma (HCC) through the activation of STAT1. We found that aspirin not only significantly enhanced IFN-α-induced antiproliferation and apoptosis of HCC in vitro study but also enhanced tumor growth inhibition in nude mice. Although IFN-α alone resulted in significant phosphorylation of both STAT1 and STAT3, aspirin only prompted the IFN-α-induced phosphorylation of STAT1. Further study revealed that aspirin-prompted phosphorylation of STAT1 was activated through phosphorylation of JAK1. Furthermore, aspirin-activated STAT1 upregulated the transcription of proapoptotic IFN-stimulated gene (ISG) of X-linked inhibitor of apoptosis-associated factor-1 and downregulated the transcription of antiapoptotic ISG of G1P3, which in turn promoted the expression of Bax and activation of caspase-9 and caspase-3, thereby sensitizing HCC cells to IFN-α-induced apoptosis. Taken together, our findings suggest a novel strategy of using aspirin to overcome tumor resistance and enhance the effectiveness of IFN-α in HCC treatment through activating STAT1 gene, and have potential implications for improving future IFN-α protein and gene therapy.

The aim of this study is to examine the response of Pinctada maxima shell to drilling predation, focusing on the underlying protective mechanisms. The shell exhibits a self-assembled smart architecture with a highly multilayered structure. The outer layer is composed of a prismatic structure, and the inner nacreous layer consists of several sub-layers that contain normal brick-like platelets and unique convex lens-like platelets, with myostracal layers laying in between them. Such a smart architecture provides several fundamental protective mechanisms against drilling penetration. First, the occurrence of multiple microcracking and the deformability of platelets in the nacre structure with brick-like platelets can effectively lock the damage locally during drilling penetration. Second, a few myostracal layers embedded within the nacre structure as a disguise of fresh body may induce the driller to inject the toxic salivary secretions, thus protecting the platelets at the bottom of the hole. Third, a new type of platelets with a convex lens-like shape is observed for the first time to be positioned in the internal part of the shell. This layer can effectively prevent the final attack due to its remarkable plastic deformation capacity or bendability via converting a part of tensile stresses into compressive stresses through interfacial sliding and rotation among the convex lens-like platelets. The findings of the present study can pave the way for the development of bioinspired advanced engineering structures with superior protectability against the penetration.

A multi-band microwave filter design method by using the defected microstrip structure (DMS) is developed. A new DMS bandpass filter with a tri-band is designed, fabricated and measured, and the experiment demonstrates the new proposal. The new DMS filter has the advantages of a compact and simple circuit topology, miniature circuit size, individually controllable centre frequencies and individually tunable bandwidths.