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Baculovirus is an ideal pathogenic microbial pesticide for the control of pests in agriculture and forestry. This study isolated and purified a new viral strain that can infect the larvae of Neodiprion zhejiangensis Zhou & Xiao, named NezhNPV. Ultrastructure studies indicated that the virus is a single nucleocapsid nucleopolyhedrovirus with a diameter of 0.47-0.91 ìm. Biological activity assays showed that NezhNPV is highly virulent in the third instar larvae of N. zhejiangensis, with an LC50 of 1.15×104 polyhedral inclusion bodies (PIB)/ml. The LT50 of the virus increased with decreasing viral concentrations. When the viral concentrations were 7×107, 7×106, 7×105, 7×104, and 7×103 PIB/ml, the LT50 values were 3.70, 4.12, 4.56, 5.08, and 6.24 d, respectively. Interestingly, unlike the Hymenoptera virus, which only infects the midgut, this virus can infect various tissues of parasites, such as the fat body, trachea, and epidermal cells. [ABSTRACT FROM AUTHOR]

Background: This study was carried out to investigate effects of threonine levels on growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp (Ctenopharyngodonidella). Results: Weight gain, specific growth rate, feed intake and feed efficiency were significantly improved by dietary threonine (P < 0.05). Intestinal activities of trypsin, chymotrypsin, alpha-amylase, lipase, alkaline phosphatase, γ-glutamyl transpeptidase and creatine kinase took the similar trends. Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation (P < 0.05). Anti-superoxide anion capacity, anti-hydroxyl radical capacity, glutathione content and activities of superoxide dismutase, catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine (P < 0.05). Conclusions: Dietary threonine could improve growth, enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp. The dietary threonine requirement of sub-adult grass carp (441.9-1,013.4 g) based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis. [ABSTRACT FROM AUTHOR]

Diapause hormone (DH), which can terminate diapause in Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), has shown promise as a pest control method. However, the main challenge in using DH as an insecticide lies in achieving effective oral delivery, since the peptide may be degraded by digestive enzymes in the gut. To improve the efficacy of oral DH application, the Clostera anastomosis (L.) (Lepidoptera: Notodontidae) diapause hormone (caDH) was fused to the Protein Transduction Domain (PTD) of the human immunodeficiency virus-1 transactivator of transcription (TAT). Cellular transduction of TAT-caDH was verified with the use of a green fluorescent protein fusion, and its ability to terminate diapause was verified by injection into diapausing H. armigera pupae. Orally administered TAT-caDH resulted in larval growth inhibition. In TAT-caDH–treated insects, larval duration was delayed and the pupation rates were decreased at both development promoting conditions [27°C, a photoperiod of 14:10(L:D) h] and diapause inducing conditions [20°C, a photoperiod of 10:14(L:D) h]. No significant difference in diapause rate was observed between the TAT-caDH– treated and caDH-treated or control pupae maintained at diapause inducing conditions. Our results show that treatment with a recombinant TAT-caDH protein can affect larval development in H. armigera, and it suggest that TAT-DH treatment may be useful for controlling pests. This study is the first record of oral DH application in insect. [ABSTRACT FROM AUTHOR]

A novel Al-7.5Zn-1.6Mg-1.4Cu-0.12Zr alloy was subjected to the retrogression and re-ageing (RRA) treatments at a lower range of retrogression temperatures from 170 to 200°C. The effect of RRA on the mechanical properties, electrical conductivity and the microstructure of the alloy has been investigated. The results indicate that an increase in the yield strength of the alloy can be achieved after RRA treatment. With increase of the retrogression temperature, the retrogression time for keeping the strength levels similar to T6 temper decreases rapidly. When submitted to RRA at 170°C for 90-120 min, the alloy can obtain a good performance on both SCC and mechanical strength; the electrical conductivity was above 40%IACS, reaching values typical for T76 condition and the tensile yield strength values were 552-570 MPa which is higher than that of the T6 temper. The microstructure is a very fine distribution of GP zones and η′ precipitates inside grains, similar to T6 condition and η precipitates on grain boundaries distributed similarly to T7 temper. [ABSTRACT FROM AUTHOR]

According to the problems which the researchers at home and abroad have studied, the article establishes the system of industry cluster model based on the value chain, and analyzes the process of collusion risk evolved in industry cluster by perturbation theory based on value chain, aiming to find theoretical basis for controlling the evolvement process of collusion risk. [ABSTRACT FROM AUTHOR]

With the rapid development of modern science and technology, the application of microscope technology has also matured and has been widely used in the observation and research of metal properties. Because high-strength aluminum alloys have corrosion resistance and high fracture toughness, the performance of the alloy can be checked by performing a microscopic fatigue test under a polarized light microscope. However, fatigue and fracture of high-strength aluminum alloys have become the biggest drawbacks that restrict its development. Therefore, it is necessary to carry out research on the micro-mechanism of short-fatigue crack growth of high-strength aluminum alloys. The purpose of this article is to solve the micro-mechanism of fatigue fracture of high-strength aluminum alloys. Through the study of the micro-mechanism of short fatigue crack growth of high-strength aluminum alloys, the electron backscatter diffraction technology is used to build a universal model of fatigue life reliability and fatigue performance reliability. Microscope experiments were performed on the microscope, and the results of fatigue experiments, fatigue crack growth rate tests, and fracture toughness tests were analyzed to obtain the relationship of fatigue fracture propagation of high-strength aluminum alloys. The research results show that the study of the micro-mechanism of short fatigue crack growth of this high-strength aluminum alloy can obtain the relationship between the grain orientation of adjacent grains and crack growth following the crystal plastic deformation mechanism of the crack tip. When the effective slip surface between two adjacent grains cannot form a 45-degree double-sided angle, the crack cannot directly pass through the grain boundary, and tends to propagate along the grain, which will cause fatigue fracture. [ABSTRACT FROM AUTHOR]

Type I IFNs (IFN-Is) play pivotal roles in host defense against viral infections but remain enigmatic against bacterial pathogens. In this study, we recombinantly expressed and purified intact grass carp (Ctenopharyngodon idella) IFNφ1 (gcIFNφ1), a teleost IFN-I. gcIFNφ1 widely powerfully directly kills both Gram-negative and Gram-positive bacteria in a dose-dependent manner. gcIFNφ1 binds to LPS or peptidoglycan and provokes bacterial membrane depolarization and disruption, resulting in bacterial death. Furthermore, gcIFNφ1 can efficiently protect zebrafish against Aeromonas hydrophila infection and significantly reduce the bacterial loads in tissues by an infection model. In addition, we wonder whether antibacterial IFN-I members exist in other vertebrates. The amino acid compositions of representative IFN-Is with strong positive charges from Pisces, Amphibia, reptiles, Aves, and Mammalia demonstrate high similarities with those of 2237 reported cationic antimicrobial peptides in antimicrobial peptide database. Recombinant intact representative IFN-I members from the nonmammalian sect exhibit potent broad-spectrum robust bactericidal activity through bacterial membrane depolarization; in contrast, the bactericidal activity is very weak from mammalian IFN-Is. The findings display a broad-spectrum potent direct antimicrobial function for IFN-Is, to our knowledge previously unknown. The results highlight that IFN-Is are important and robust in host defense against bacterial pathogens, and unify direct antibacterial and indirect antiviral bifunction in nonmammalian jawed vertebrates. [ABSTRACT FROM AUTHOR]

Type I IFN mediates the innate immune system to provide defense against viral infections. NF-kB-inducing kinase (NIK) potentiates the basal activation of endogenous STING, which facilitates the recruitment of TBK1 with the ectopically expressed IRF3 to induce IFN production. Moreover, NIK phosphorylates IKKa and confers its ability to phosphorylate p100 (also known as NF-kB2) in mammals. Our study demonstrated that NIK plays a critical role in IFN production in teleost fish. It was found that NIK interacts with IKKa in the cytoplasm and that IKKa phosphorylates the NIK at the residue Thr432, which is different from the mammals. Overexpression of NIK caused the activation of IRF3 and NF-kB, which in turn led to the production of IFN and IFN-stimulated genes (ISGs). Furthermore, the ectopic expression of NIK was observed to be associated with a reduced replication of the fish virus, whereas silencing of endogenous NIK had an opposite effect in vitro. Furthermore, NIK knockdown significantly reduced the expression of IFN and key ISGs in zebrafish larvae after spring viremia of carp virus infection. Additionally, the replication of spring viremia of carp virus was enhanced in NIK knockdown zebrafish larvae, leading to a lower survival rate. In summary, our findings revealed a previously undescribed function of NIK in activating IFN and ISGs as a host antiviral response. These findings may facilitate the establishment of antiviral therapy to combat fish viruses. [ABSTRACT FROM AUTHOR]