1,304 research outputs found

    Controlling sap-sucking insect pests with recombinant endophytes expressing plant lectin

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    We developed a novel pest management strategy, which uses endophytes to express anti-pest plant lectins. Fungal endophyte of Chaetomium globosum YY-11 with anti-fungi activities was isolated from rape seedlings, and bacterial endophytes of SJ-10 (Enterobacter sp.) and WB (Bacillus subtilis) were isolated from rice seedlings. Pinellia ternate agglutinin gene was cloned into SJ-10 and WB for expression by a shuttle vector, and YY-11 was mediated by Agrobacterium tumefaciens. Positive transformants were evaluated using PCR and Western blot assay. Recombinant endophytes colonized most of crops, and resistance of rice seedlings, which were inoculated with the recombinant endophytic bacteria, to white backed planthoppers was dramatically enhanced by decreasing the survival and fecundity of white backed planthoppers. Rape inoculated with recombinant endophytic fungi significantly inhibited the growth and reproduction of aphids. Recombinant endophytes expressing PTA may endow hosts with resistance against sap-sucking pests

    Molecular dynamics simulation of graphene sinking during chemical vapor deposition growth on semi-molten Cu substrate

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    Copper foil is the most promising catalyst for the synthesis of large-area, high-quality monolayer graphene. Experimentally, it has been found that the Cu substrate is semi-molten at graphene growth temperatures. In this study, based on a self-developed C-Cu empirical potential and density functional theory (DFT) methods, we performed systematic molecular dynamics simulations to explore the stability of graphene nanostructures, i.e., carbon nanoclusters and graphene nanoribbons, on semi-molten Cu substrates. Many atomic details observed in the classical MD simulations agree well with those seen in DFT-MD simulations, confirming the high accuracy of the C-Cu potential. Depending on the size of the graphene island, two different sunken-modes are observed: (i) graphene island sinks into the first layer of the metal substrate and (ii) many metal atoms surround the graphene island. Further study reveals that the sinking graphene leads to the unidirectional alignment and seamless stitching of the graphene islands, which explains the growth of large single-crystal graphene on Cu foil. This study deepens our physical insights into the CVD growth of graphene on semi-molten Cu substrate with multiple experimental mysteries well explained and provides theoretic references for the controlled synthesis of large-area single-crystalline monolayer graphene

    The formation and stability of junctions in single-wall carbon nanotubes

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    The structure and stability of molecular junctions, which connect two single-wall carbon nanotubes (SWCNTs) of different diameters and chiral angles, (n(1), m(1))-(n(2), m(2)), are systematically investigated by density functional tight binding calculations. More than 100 junctions, which connect well-aligned SWCNTs, were constructed and calculated. For a highly stable junction between two chiral (n(1), m(1)) and (n(2), m(2)) SWCNTs with opposite handedness, the number of pentagon-heptagon (5/7) pairs required to build the junction can be denoted as vertical bar vertical bar n(2) - n(1)vertical bar - vertical bar m(2) - m(1)vertical bar vertical bar + min{vertical bar n(2) - n(1)vertical bar, vertical bar m(2) - m(1)vertical bar} with (n(2), m(2)) rotating pi/3 angle or not. While for a junction connected by two zigzag, armchair or two chiral SWCNTs with the same handedness, the number of 5/7 pairs is equal to vertical bar n(1) - n(2)vertical bar + vertical bar m(1) - m(2)vertical bar. Similar to the formation energies of grain boundaries in graphene, the curve of the formation energies vs. chiral angle difference present an 'M' shape indicating the preference of similar to 30 degree junctions. Moreover, the formation energies of the zigzag-type and armchair-type junctions with zero misorientation angles are largely sensitive to the diameter difference of two sub-SWCNTs

    Social Preference Deficits in Juvenile Zebrafish Induced by Early Chronic Exposure to Sodium Valproate

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    Prenatal exposure to sodium valproate (VPA), a widely used anti-epileptic drug, is related to a series of dysfunctions, such as deficits in language and communication. Clinical and animal studies have indicated that the effects of VPA are related to the concentration and to the exposure window, while the neurobehavioral effects of VPA have received limited research attention. In the current study, to analyze the neurobehavioral effects of VPA, zebrafish at 24 hours post-fertilization (hpf) were treated with early chronic exposure to 20 μM VPA for 7 hours per day for 6 days or with early acute exposure to 100 μM VPA for 7 hours. A battery of behavioral screenings was conducted at 1 month of age to investigate social preference, locomotor activity, anxiety and behavioral response to light change. A social preference deficit was only observed in animals with chronic VPA exposure. Acute VPA exposure induced a change in the locomotor activity, while chronic VPA exposure did not affect locomotor activity. Neither exposure procedure influenced anxiety or the behavioral response to light change. These results suggested that VPA has the potential to affect some behaviors in zebrafish, such as social behavior and the locomotor activity, and that the effects were closely related to the concentration and the exposure window. Additionally, social preference seemed to be independent from other simple behaviors

    Dynamic changes and significance of sputum cells in bronchiolitis

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    Objective: To observe the cell composition and changes of sputum cells in children with bronchiolitis at different stages of disease, and to explore their role in the pathogenesis of disease. Methods: 75 children hospitalized in 2016 compliance with standard bronchiolitis were selected. The course of the disease was divided into acute attack period, the improvement period and remission period. The levels of sputum cells, such as sputum shedding epithelial cells, neutrophils, eosinophil, lymphocytes and other sputum cells were examined by light microscopy at different stages of acute exacerbation, disease progression and remission. The expression and proportion of cells were compared, and the differences of cell expression and clinical significance were compared. Results: In the early stage of acute bronchiolitis, the sputum cells were mainly neutral and exfoliated epithelium, lymphocytes and eosinophil were small. When the condition improved, the epithelial cells and the neutrophils decreased, while the lymphocytes and allergic family history of children with eosinophil correspondingly increased. During the remission period, neutrophils and sputum shedding epithelium continued to decrease, while the lymphocytes, eosinophil continued to increase. Conclusions: Epithelial cell shedding is a common phenomenon in the acute attack of bronchiolitis, which may be associated with the wheezing symptoms of children. During the acute stage and improvement phase, there is a significant increase in sputum neutrophils attributable to infection. Eosinophilia is associated with anaphylactic individual and family history, and increased eosinophilia is associated with high airway reactivity and prolonged wheezing. Lymphocytes play a role in maintaining chronic airway inflammation

    [5-Chloro-2-hy­droxy-N′-(2-oxidobenzyl­idene)benzohydrazidato]dimethyl­tin(IV)

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    In the title compound, [Sn(CH3)2(C14H9ClN2O3)], the SnIV ion is coordinated by one N and two O atoms from the tridentate 5-chloro-2-hy­droxy-N′-(2-oxidobenzyl­idene)benzohydrazidate (L) ligand and two methyl groups in a distorted trigonal–bipyramidal geometry. In the ligand, the hy­droxy group is involved in an intra­molecular O—H⋯N hydrogen bond and the two aromatic rings form a dihedral angle of 5.5 (1)°. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds and π–π inter­actions between the aromatic rings [centroid–centroid distance = 3.816 (3) Å] link the mol­ecules into centrosymmetric dimers

    Sequencing of blaIMP-Carrying IncN2 Plasmids, and Comparative Genomics of IncN2 Plasmids Harboring Class 1 Integrons

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    This work presents the complete nucleotide sequences of p0801-IMP from Klebsiella pneumoniae, p7121-IMP from K. oxytoca, and p17285-IMP from Citrobacter freundii, which are recovered from three different cases of nosocomial infection. These three plasmids represent the first fully sequenced bla(IMP)-carrying IncN2 plasmids. Further comparative genomics analysis of all the five integron-carrying IncN2 plasmids p0801-IMP, p7121-IMP, p17285-IMP, pJIE137, and p34983-59.134kb indicates that they possess conserved IncN2 backbones with limited genetic variations with respect to gene content and organization. Four class 1 integrons (bla(IMP-1)-carrying In1223 in p0801-IMP/p7121-IMP, bla(IMP-8)-carrying In655 in p17285-IMP, In27 in pJIE137, and In1130 in p34983-59.134kb), two insertion sequence-based transposition units (ISEcp1-orfRA1-14 in p17285-IMP, and ISEcp1-bla(CTX-M-62)-Δorf477-orfRA1-14 in pJIE137), and a novel Tn1696-related transposon Tn6325 carrying In1130 in p34983-59.134kb are indentified in the plasmid accessory regions. In1223 and In655 represent ancestral Tn402-associated integrons, while In27 and In1130 belong to complex class 1 integrons. The relatively small IncN2 backbones are able to integrate different mobile elements which carry various resistance markers, promoting the accumulation and spread of antimicrobial resistance genes among enterobacterial species

    3-Hy­droxy-N′-[(E)-3-pyridyl­methyl­idene]-2-naphtho­hydrazide

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    The title compound, C17H13N3O2, displays an E configuration about the C=N bond. The mean planes of the pyridine and benzene rings make a dihedral angle of 31.2 (2)°. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, inter­molecular N—H⋯N hydrogen bonding links the mol­ecules into a chain along [101]

    Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

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    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2, 5.19±3.8, and 6.23±3.9 μm at the center, paracenter, and mid-periphery, resp., P<0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp., P<0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia

    Identifying Tmem59 related gene regulatory network of mouse neural stem cell from a compendium of expression profiles

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    <p>Abstract</p> <p>Background</p> <p>Neural stem cells offer potential treatment for neurodegenerative disorders, such like Alzheimer's disease (AD). While much progress has been made in understanding neural stem cell function, a precise description of the molecular mechanisms regulating neural stem cells is not yet established. This lack of knowledge is a major barrier holding back the discovery of therapeutic uses of neural stem cells. In this paper, the regulatory mechanism of mouse neural stem cell (NSC) differentiation by <it>tmem59 </it>is explored on the genome-level.</p> <p>Results</p> <p>We identified regulators of <it>tmem59 </it>during the differentiation of mouse NSCs from a compendium of expression profiles. Based on the microarray experiment, we developed the parallelized SWNI algorithm to reconstruct gene regulatory networks of mouse neural stem cells. From the inferred <it>tmem59 </it>related gene network including 36 genes, <it>pou6f1 </it>was identified to regulate <it>tmem59 </it>significantly and might play an important role in the differentiation of NSCs in mouse brain. There are four pathways shown in the gene network, indicating that <it>tmem59 </it>locates in the downstream of the signalling pathway. The real-time RT-PCR results shown that the over-expression of <it>pou6f1 </it>could significantly up-regulate <it>tmem59 </it>expression in C17.2 NSC line. 16 out of 36 predicted genes in our constructed network have been reported to be AD-related, including <it>Ace</it>, <it>aqp1</it>, <it>arrdc3</it>, <it>cd14</it>, <it>cd59a</it>, <it>cds1</it>, <it>cldn1</it>, <it>cox8b</it>, <it>defb11</it>, <it>folr1</it>, <it>gdi2</it>, <it>mmp3</it>, <it>mgp</it>, <it>myrip</it>, <it>Ripk4</it>, <it>rnd3</it>, and <it>sncg</it>. The localization of <it>tmem59 </it>related genes and functional-related gene groups based on the Gene Ontology (GO) annotation was also identified.</p> <p>Conclusions</p> <p>Our findings suggest that the expression of <it>tmem59 </it>is an important factor contributing to AD. The parallelized SWNI algorithm increased the efficiency of network reconstruction significantly. This study enables us to highlight novel genes that may be involved in NSC differentiation and provides a shortcut to identifying genes for AD.</p
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