443 research outputs found

    Antiproliferative activity of recombinant human interferon-λ2 expressed in stably transformed BmN cells

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    This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the human IFN-λ2 gene. After the BmN cells were transfected with the pIZT/V5- His- hIFN-λ2 vector, the stably transformed BmN cells expressing hIFN-λ2 gene were selected using Zeocin. Following two months of screening, the transformed BmN cell line was obtained. Stable transformed BmN cell line can be maintained at a lower Zeocin concentration. The representing 26 kDa protein band of IFN-λ2 was detected by SDS-PAGE and Western blotting. The expression level of hIFN- λ2, determined by ELISA, was about 8.142 ng in 4 × 105 cells. The antiproliferative activity of hIFN-λ2 was determined by MTT assay. The 50% inhibitory concentrations (IC50) of the recombinant hIFN-λ2 on A549 (lung cancer cells), HL60 (acute promyelocytic leukemia cells), BEL-7402 (liver cancer cells) and M231 cells (breast cancer cells) were approximately 3.21, 2.84, 6.29 and 9.32 ng/ml, respectively. In summary, Human IFN-λ2 can be stably expressed in the transformed BmN cell line, and the expressed recombinant hIFN-λ2 demonstrated antiproliferative activity to tumor cells in vitro.Key words: Human interferon-λ2 protein, gene expression, antiproliferative activity

    Allelopathy of root exudates from different resistant eggplants to Verticillium dahliae and the identification of allelochemicals

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    Three eggplant cultivars were inoculated with Verticillium dahliae Kleb. to assess their resistance to Verticillium wilt. Solanum tor was resistant, “Liyuanziqie” was tolerant, and “Xi’anlvqie” susceptible. The disease incidence and disease index of Verticillium wilt and the amount of V. dahliae in rhizospheric soil, variation of microbial composition, the allelopathy of root exudates to mycelium growth of V. dahliae and the chemical substances of root exudates from eggplant cultivars with different resistance to Verticillium wilt were investigated in this experiment. The results showed that the root exudates of resistant type could not only affect the growth and development of V. dahliae, but also influence V. dahliae indirectly through regulating soil microbial community composition. This may be one of the reasons for the increase of disease resistance. However, the susceptible type exhibited an opposite trend. It was inferred that the resistant type contained some particular components, such as  acohd, amide, pyranoid, fluorene, while the susceptible one comprised more types of components, that is, ketone, phenol, ester and phenolic acid.Key words: Allelopathy, allelochemical, root exudates, eggplant, Verticillium dahliae, Verticillium wilt, microbial composition

    The sudden change phenomenon of quantum discord

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    Even if the parameters determining a system's state are varied smoothly, the behavior of quantum correlations alike to quantum discord, and of its classical counterparts, can be very peculiar, with the appearance of non-analyticities in its rate of change. Here we review this sudden change phenomenon (SCP) discussing some important points related to it: Its uncovering, interpretations, and experimental verifications, its use in the context of the emergence of the pointer basis in a quantum measurement process, its appearance and universality under Markovian and non-Markovian dynamics, its theoretical and experimental investigation in some other physical scenarios, and the related phenomenon of double sudden change of trace distance discord. Several open questions are identified, and we envisage that in answering them we will gain significant further insight about the relation between the SCP and the symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F. F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp 309-33

    Smoking, cessation and expenditure in low income Chinese: cross sectional survey

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    BACKGROUND: This study was carried-out to explore smoking behaviour and smoking expenditure among low income workers in Eastern China to inform tobacco control policy. METHODS: A self-completion questionnaire was administered to 1958 urban workers, 1909 rural workers and 3248 migrant workers in Zhejiang Province, Eastern China in 2004. RESULTS: Overall 54% of the men and 1.8% of all women were current smokers (at least 1 cigarette per day). Smoking was least common in migrant men (51%), compared with 58% of urban workers and 64% rural inhabitants (P < 0.0001). Forty-nine percent of rural males smoke more than 10 cigarettes/day, and 22% over 20/day. The prevalence of smoking increased with age. Overall 9% of the males had successfully quit smoking. Reasons for quitting were to prevent future illness (58%), current illness (31%), family pressures (20%) and financial considerations (20%). Thirteen percent of current smokers had ever tried to quit (cessation for at least one week) while 22% intended to quit, with migrants most likely to intend to quit. Almost all (96%) were aware that smoking was harmful to health, though only 25% were aware of the dangers of passive smoking. A mean of 11% of personal monthly income is spent on smoking rising to a mean of 15.4% in rural smokers. This expenditure was found to have major opportunity costs, including in terms of healthcare access. CONCLUSION: The prevalence of smoking and successful quitting suggest that smoking prevalence in low income groups in Eastern China may have peaked. Tobacco control should focus on support for quitters, on workplace/public place smoking restrictions and should develop specific programmes in rural areas. Health education messages should emphasise the opportunity costs of smoking and the dangers of passive smoking

    Tube Formation in Nanoscale Materials

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    The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities

    Male Germ Cell Apoptosis and Epigenetic Histone Modification Induced by Tripterygium wilfordii Hook F

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    Multiglycosides of Tripterygium wilfordii Hook f (GTW), a Chinese herb-derived medicine used as a remedy for rheumatoid arthritis, are considered to be a reversible anti-fertility drug affecting the mammalian spermatids. However, the mechanism behind this effect is still unknown. To study the possible mechanism behind the impact of GTW on spermatogenesis, we administered 4 groups of 4-week-old male mice with different doses of GTW. We found a dose-dependent decrease in the number of germ cells after 40 days of GTW treatment, and an increase in apoptotic cells from the low-dose to the high-dose group. During this same period the dimethylated level of histone H3 lysine 9 (H3K9me2) in GTW-treated testes germ cells declined. Additionally, spermatogonial stem cells (SSCs) from 6-day-old mice were isolated to evaluate the possible effect of GTW or triptolide on development of SSCs. We found a significantly higher incidence of apoptosis and lower dimethylation level of H3K9me2 in the SSCs of GTW or triptolide treatment than in controls. Thus, these data suggest that the GTW-induced apoptosis might be responsible for the fertility impairment in mice. This damage could be traced back to the early stages of spermatogenesis. GTW also affected the epigenetic modification of H3K9 in spermatogenesis. Molecular dynamics simulation suggested that triptolide and dimethylated or trimethylated H3K9 might have similar interaction mechanisms with EED (embryonic ectoderm development). These candidate activation mechanisms provide the first glimpse into the pathway of GTW-induced gonad toxicity, which is crucial for further research and clinical application

    Skp is a multivalent chaperone of outer membrane proteins

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    The trimeric chaperone Skp sequesters outer-membrane proteins (OMPs) within a hydrophobic cage, thereby preventing their aggregation during transport across the periplasm in Gram-negative bacteria. Here, we studied the interaction between Escherichia coli Skp and five OMPs of varying size. Investigations of the kinetics of OMP folding revealed that higher Skp/OMP ratios are required to prevent the folding of 16-stranded OMPs compared with their 8-stranded counterparts. Ion mobility spectrometry–mass spectrometry (IMS–MS) data, computer modeling and molecular dynamics simulations provided evidence that 10- to 16-stranded OMPs are encapsulated within an expanded Skp substrate cage. For OMPs that cannot be fully accommodated in the expanded cavity, sequestration is achieved by binding of an additional Skp trimer. The results suggest a new mechanism for Skp chaperone activity involving the coordination of multiple copies of Skp in protecting a single substrate from aggregation
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