1,874 research outputs found
On the constant for the Banaś-Frączek space
No full textIn this paper, for any is the Banaś-Frączek space. The exact value of for this space will be calculated. Specifically, is the result thereafter through meticilous computation.for associated mpeg file, see http://myhost.domain/file.mp
Cancer-Associated Fibroblasts: Epigenetic Regulation and Therapeutic Intervention in Breast Cancer
No full textDistribution of N-alkanes and polycyclic aromatic hydrocarbons in the urban atmosphere of Guangzhou, China.
No full textMeso-Cenozoic uplifting and exhumation on Yunkaidashan: Evidence from fission track thermochronology
No full textINVESTIGATION OF MECHANICAL BEHAVIOR OF INTERFACES IN NANOSTRUCTURED METALS
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将常规多晶材料的粗晶粒尺寸缩小到纳米尺度时,这些纳米晶体材料会呈现出与其对应的粗晶材料迥异的物理现象.与材料力学行为最相关的是强度及塑形变形机理这两个方面.考虑到晶界的变形与破坏可能是纳米晶体材料低塑性的根源,克服纳米晶体材料中强度与韧性之间存在的“熊掌和鱼不可兼得”的问题,也通常称为晶界工程.在众多的晶界中,孪晶界面被发现可同时保持材料的强度和韧性.本文主要就纳米金属材料中界面的力学行为做一个简要述,包含晶界的强化力学机理以及新型孪晶界面的力学行为与揭示内在尺度效应的模型研究。</p
Expression of a full-length hepatitis C virus cDNA up-regulates the expression of CC chemokines MCP-1 and RANTES.
No full textAbstractWe had previously reported the cloning of the complete genome of an isolate of hepatitis C virus (HCV), HCV-S1, of genotype 1b. We have constructed a full-length complementary DNA (cDNA) clone of HCV-S1 using nine overlapping cDNA clones that encompassed its entire genome. HCV core, E1, E2, NS-3, -4B, -5A, and -5B proteins were detected in 293T cells by immunoblot analyses when expression of the full-length HCV-S1 was driven under a CMV promoter. Expression of full-length HCV-S1 led to induction of the CC chemokines RANTES and MCP-1 at both the mRNA and the protein levels in HeLa, Huh7, and HepG2 cells. Reporter gene assays showed that a minimal MCP-1 promoter construct containing 128 nucleotides upstream of its translational start site was sufficient for optimal HCV-mediated activation. HCV induced AP-1 binding activities to this region, as determined from electrophoretic mobility shift assays and supershifts with anti-AP-1 antibodies. Transfection of full-length HCV-S1 up-regulated both AP-1 binding activities as well as c-jun transcripts. A minimal promoter construct containing 181 nucleotides upstream of the RANTES translational start site was sufficient for maximal HCV-mediated induction. Gel mobility shift and supershift assays showed that HCV induced NF-κB and other unknown binding activities to the A/B-site within this region. In HeLa cells, HCV core and NS5A could separately augment promoter activities of both MCP-1 and RANTES. In Huh7 cells, only NS5A produced a similar effect, while rather surprisingly, HCV core induced a dramatic reduction in promoter activities of these two genes. This study provides the first direct evidence for the induction of CC chemokines in HCV infection and draws attention to their roles in affecting the progress and outcome of HCV-associated liver diseases
Two LTR retrotransposon elements within the abscisic acid gene cluster in Botrytis cinerea B05.10, but not in SAS56
No full textThe plant hormone abscisic acid has huge economic potential and can be applied in agriculture and forestry for it is considered to be involved in plant resistance to stresses such as cold, heat, salinity, drought, pathogens and wounding. Now overproducing strains of Botrytis cinerea are used for biotechnological production of abscisic acid. An LTR retrotransposon, Boty-aba, and a solo LTR were identified by in silico genomic sequence analysis, and both were detected within the abscisic acid gene cluster in B. cinerea B05.10, but not in B. cinerea SAS56. Boty-aba contains a pair of LTRs and two internal genes. The LTRs and the first gene have features characteristic of Ty3/gypsy LTR retrotransposons. The second gene is a novel gene, named brtn, which encodes for a protein (named BRTN) without putative conserved domains. The impressive divergence in structure of the abscisic acid gene clusters putatively gives new clues to investigate the divergence in the abscisic acid production yields of different B. cinerea strains
Boty-II, a novel LTR retrotransposon in Botrytis cinerea B05.10 revealed by genomic sequence
No full textBotrytis cinerea is a necrotrophic pathogen causing pre- and post-harvest diseases in at least 235 plant species. It manifests extraordinary genotype and phenotype variation. One of the causes of this variation is transposable elements. Two transposable elements have been discovered in this fungus, the retrotransposon (Boty), and the transposon (Flipper). In this work, two complete (Boty-II-76 and Boty-II-103) and two partial (Boty-II-95 and Boty-II-141) long terminal repeat (LTR) retrotransposons were identified by an in silico genomic sequence analysis. Boty-II-76 and Boty-II-103 contain 6439 bp nucleotides with a pair of LTRs at both ends, and an internal deduced pol gene encoding a polyprotein with reverse transcriptase and DDE integrase domains. They are flanked by 5 bp direct repeats (ACCAT, CTTTC). In Boty-II-141, two LTRs at both ends, and a partial internal pol gene encoding a protein with a DDE integrase domain were identified. In Boty-II-95, a right LTR and a partial internal pol gene encoding a protein with no conserved domains were identified. Boty-II uses a self-priming mechanism to initiate synthesis of reverse transcripts. The sequence of the presumed primer binding site for first-strand reverse transcription is 5'-TTGTACCAT-3'. The polypurine-rich sequence for plus-strand DNA synthesis is 5'-GCCTTGAGCGGGGGGTAC-3'. Fourteen Boty-II LTRs that contain 125-158 bp nucleotides and share 69.1 similar to 100% identities with the short inverted terminal repeats of 5 bp (TGTCA ... TGACA) were discovered. Analysis of structural features and phylogeny revealed that Boty-II is a novel LTR retrotransposon. It could potentially be used as a novel molecular marker for the investigation of genetic variation in B. cinerea
Public perception of the appropriateness of COVID-19 management strategies and level of disturbances in daily activities: A focus on educational level
No full textBackground This study investigated the association between public perception of the appropriateness of management strategies implemented during the COVID-19 pandemic and the level of disturbances in daily activities reported by the general population. Methods This cross-sectional study used Korea Community Health Survey conducted from August to November 2020. Public perception of COVID-19 management strategies included those implemented by the government (central, city or provincial, and administrative districts), the mass media, regional medical institutions, and neighbors. The subjective level of disturbances in daily activities was measured using a 0–100 numeric rating scale developed by Korea Disease Control and Prevention Agency. Multivariable linear regression analysis was used. A subgroup analysis was conducted based on education level. Results The present study analyzed 211,353 participants. Compared to individuals who perceived that the management strategies implemented during the pandemic was ‘highly appropriate,’ those who reported ‘mediocre appropriateness’ (β: -1.96, p-value: <0.001) or ‘low appropriateness’ (β: -3.60, p-value: 0.010) reported higher levels of subjective disturbances. The appropriateness of measures implemented by the mass media was associated with levels of subjective disturbances felt by individuals of lower education with statistical significance, whereas that applied by the mass media and the government were important in those with higher education. Conclusions The findings suggest the importance of public perception of management strategies when implementing containment policies and minimizing its disturbances on daily lives is essential. © 2023 Ju et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Structural and functional characterization of human DDX5 and its interaction with NS5B of hepatitis C virus
No full textPhilosophiae Doctor - PhDHepatitis C was first recognized as a transfusion-associated liver disease not caused by hepatitis A or hepatitis B virus after serological tests were developed to screen for their presence in the blood. The infectious agent was finally identified with the cloning of the cDNA of hepatitis C virus (HCV) using random polymerase chain reaction (PCR) screening of nucleic acids extracted from plasma of a large pool of chimpanzee infected with non-A non-B hepatitis.
NS5B, a membrane-associated RNA-dependent RNA polymerase essential in the replication of HCV, initiates the synthesis of a complementary negative-strand RNA from the genomic positive-strand RNA so that more positive-strand HCV RNA can then be generated from the newly synthesised negative-strand template. The crystal structure of NS5B presented typical fingers, palm and thumb sub-domains encircling the GDD active site, which is also seen in other RNA-dependent RNA polymerases, and is similar to the structure of reverse transcriptase of HIV-1 and murine Moloney leukaemia virus. The last 21 amino acids in the C-terminus of NS5B anchor the protein to the endoplasmic reticulum (ER)-derived membranous web. NS5B has been shown to interact with the core, NS3/NS4A, NS4B and NS5A proteins, either directly or indirectly. Numerous interactions with cellular proteins have also been reported. These proteins are mainly associated with genome replication, vesicular transport, protein kinase C-related kinase 2, P68 (DDX5), α-actinin, nucleolin, human eukaryotic initiation factor 4AII, and human VAMP-associated protein. Previous studies have confirmed that NS5B binds to full-length DDX5. By constructing deletion mutants of DDX5, we proceeded to characterize this interaction between DDX5 and HCV NS5B. We report here the identification of two exclusive HCV NS5B binding sites in DDX5, one in the N-terminal region of amino acids 1 to 384 and the other in the C-terminal region of amino acids 387 to 614. Proteins spanning different regions of DDX5 were expressed and purified for crystallization trials. The N-terminal region of DDX5 from amino acids 1 to 305 which contains the conserved domain I of the DEAD-box helicase was also cloned and expressed in Escherichia coli. The cloning, expression, purification and crystallization conditions are presented in this work. Subsequently, the crystal structure of DDX5 1-305 was solved and the high resolution three-dimensional structure shows that in front of domain I is the highly variable and disordered N terminal region (NTR) of which amino acids 51-78 is observable, but whose function is unknown. This region forms an extensive loop and supplements the core with an additional α-helix. Co-immunoprecipitation experiments demonstrated that the NTR of DDX5 1-305 auto-inhibit its interaction with NS5B. Interestingly, the α-helix in NTR is essential for this auto-inhibition and seems to mediate the interaction between the highly flexible 1-60 residues in NTR and NS5B binding site in DDX5 1-305, presumably located within residues 79-305. Furthermore, co-immunoprecipitation experiments revealed that DDX5 can also interact with other HCV proteins, besides NS5B
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