365 research outputs found

    First complete mitochondrial genome of the tribe Coccini (Hemiptera, Coccomorpha, Coccidae) and its phylogenetic implications

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    Soft scale insects (Hemiptera, Coccidae) are important pests of various agricultural and horticultural crops and ornamental plants. They have negative impacts on agriculture and forestry. The tribe Coccini represents one of the most ancient evolutionary lineages of soft scale insects. However, no complete Coccini mitochondrial genome (mitogenome) is available in public databases. Here, we described the complete mitogenome of Coccus hesperidum L., 1758. The 15,566 bp mitogenome of C. hesperidum had a high A+T content (83.4%) and contained a typical set of 37 genes, with 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs) and two ribosomal RNA genes (rRNAs). Only seven tRNAs had the typical clover-leaf secondary structure and the remaining tRNAs lacked the DHU arm, TψC arm or both. Moreover, a comparative analysis of all reported scale insect mitogenomes from GenBank database was performed. The mitogenomes of scale insects showed high similarities in base composition and A+T content. Additionally, our phylogenetic analysis confirmed the monophyly of Coccomorpha and revealed that the archaeococcoids were the most basal lineage within Coccomorpha, while Ericerus pela and Didesmococcus koreanus, belonging to Coccidae, were often mixed with Aclerdidae, making Coccidae a paraphyletic group. These findings expand the mitogenome database of scale insects and provide new insights on mitogenome evolution for future studies across different insect groups

    Nanotube ferroelectric tunnel junctions with giant tunneling electroresistance ratio

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    Low-dimensional ferroelectric tunnel junctions are appealing for the realization of nanoscale nonvolatile memory devices due to their inherent advantage of device miniaturization. Those based on current mechanisms still have restrictions including low tunneling electroresistance (TER) effects and complex heterostructures. Here, we introduce an entirely new TER mechanism to construct the nanotube ferroelectric tunnel junction with ferroelectric nanotubes as the tunneling region. When rolling a ferroelectric monolayer into a nanotube, due to the coexistence of its intrinsic ferroelectric polarization with the flexoelectric polarization induced by bending, there occurs metal-insulator transition depending on radiative polarization states. For the pristine monolayer, its out-of-plane polarization is tunable by an in-plane electric field, the conducting states of the ferroelectric nanotube can thus be tuned between metallic and insulating via axial electric means. Using {\alpha}-In2Se3 as an example, our first-principles density functional theory calculations and nonequilibrium Green's function formalism confirm the feasibility of the TER mechanism and indicate an ultrahigh TER ratio exceeding 9.9*10^10% of the proposed nanotube ferroelectric tunnel junctions. Our findings provide a promising approach based on simple homogeneous structures for high density ferroelectric microelectronic devices with excellent ON/OFF performance.Comment: 15 pages, 5 figure

    Distribution of enteroviruses in hospitalized children with hand, foot and mouth disease and relationship between pathogens and nervous system complications

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    <p>Abstract</p> <p>Background</p> <p>To explore the relationship between enteroviruses and hospitalized children with hand, foot and mouth disease (HFMD) complicated with nervous system disease. 234 hospitalized HFMD patients treated in Shengjing Hospital, Liaoning Province were analyzed retrospectively. Based on the presence and severity of nervous system disease, the patients were grouped as follows: general patients, severely ill patients, critically ill patients and fatal patients. Based on the detected pathogen, the patients were grouped as follows: Enterovirus 71 (EV71) infection, coxsackie A16 (CA16) infection and other enterovirus (OE) infection.</p> <p>Results</p> <p>Of the 423 hospitalized patients, most were admitted in July 2010(129/423, 30.5%). Enteroviruses were detected in 177(41.8%). 272/423 patients were male (64.3%), and fatal patients had the greatest proportion of male patients (<it>p </it>< 0.05). EV71 infection was found in 89/423 patients (21%). CA16 infection was detected in 8/423 patients (16.1%). Compared to group CA16, patients in group EV71 were hospitalized earlier, and the duration of hospitalization was longer (<it>p </it>< 0.05). Of the 92 patients with nervous system damage, 65 were infected with EV71 and 19 were infected with CA16. Among these CA16 infected patients, 2 had brainstem encephalitis and 1 had AFP. There were more patients with nervous system dysfunction in group EV71 than in groups CA16 or OE (<it>p </it>< 0.05). The 5 fatalities all occurred in group EV71 patients (<it>p </it>< 0.05). Infection with EV71 was most likely to cause neurogenic pulmonary edema (<it>p </it>< 0.05). Patients in group EV71 had a higher rate of suffering from coma and limb movement disorder than patients in groups CA16 or OE (<it>p </it>< 0.05).</p> <p>Conclusion</p> <p>The disease progresses faster in EV71-infected HFMD patients. These patients are more likely to suffer nervous system damage, neurogenic pulmonary edema, severe sequelae or death. CA16 and other enteroviruses can also cause HFMD with severe nervous system complications.</p

    Development and characterization of a core set of SSR markers for fingerprinting analysis of Chinese maize varieties

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    A core set of 60 SSRs was selected and modified using 231 Chinese and USA maize (Zea mays L.) inbred lines from more than 2000 SSRs for DNA fingerprinting analysis. All 60 SSR markers met the following criteria: (1) amplification of a single locus; (2) distinct amplification products; (3) adequate intervals between adjacent alleles; (4) suitable PCR fragment size; (5) reasonable discrimination power (DP); and (6) even distribution across the maize genome. Furthermore, the 60 SSR primers were re-designed to adjust the PCR product size. Together with the application of four different fluorescent dyes, a high-throughput 10-plex capillary electrophoresis platform was explored. The 60 core SSR markers were further divided into three groups (20 SSRs per group) according to peak morphology and DP value. Groups I, II and III were used in DNA fingerprinting analysis as a basic core, an expanded core and a candidate core set respectively. The allele number per locus varied from three to 22 with an average of 8.95; the average number of alleles per group I, II and III was a respective 7.35, 7.8 and 11.4. The DP values ranged from 0.366 to 0.913, with an average of 0.718 among all loci; the average group DP values were 0.697, 0.718 and 0.737 for groups I, II and III respectively; and the cumulative values of discrimination power (CDP) approached 1 for all groups. Cluster analysis results using 60 selected loci divided the Chinese inbred lines into six groups, including Luda Red Cob, P, Improved Reid, Tang-si-ping-tou, Waxy and Lancaster. The USA inbred lines were segregated into four groups, including SSS, Lancaster, Iodent and Oh43/Oh07Mid mixed

    Oral administration of a select mixture of Bacillus probiotics generates Tr1 cells in weaned F4ab/acR− pigs challenged with an F4+ ETEC/VTEC/EPEC strain

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    Dose effect of oral administration of BLS-mix on the growth of newly weaned pigs before and after F4 + ETEC/VTEC/EPEC challenge. The table shows the growth of newly weaned pigs before and after F4+ ETEC/VTEC/EPEC challenge. In the first 2 weeks following the challenge, average daily weight gain and feed intake were lower in ETEC pigs compared with CONT pigs (P = 0.011 and P = 0.018, respectively), but there were no differences relative to the CONT pigs in these parameters in the LDBE or HDBE groups

    Lactobacillus rhamnosus GR-1 Ameliorates Escherichia coli-Induced Activation of NLRP3 and NLRC4 Inflammasomes With Differential Requirement for ASC

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    Escherichia coli is a common cause of mastitis in dairy cows. The adaptor protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) synergizes with caspase-1 to regulate inflammasome activation during pathogen infection. Here, the ASC gene was knocked out in bovine mammary epithelial (MAC-T) cells using clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated (Cas)-9 technology. MAC-T cells were pre-incubated with and without Lactobacillus rhamnosus GR-1 and then exposed to E. coli. Western blot analysis demonstrated increased expression of NLRP3 and NLRC4 following E. coli infection, but this increase was attenuated by pre-incubation with L. rhamnosus GR-1, regardless of ASC knockout. Western blot and immunofluorescence analyses revealed that pre-incubation with L. rhamnosus GR-1 decreased E. coli-induced caspase-1 activation at 6 h after E. coli infection, as also observed in ASC-knockout MAC-T cells. The E. coli-induced increase in caspase-4 mRNA expression was inhibited by pre-incubation with L. rhamnosus GR-1. ASC knockout diminished, but did not completely prevent, increased production of IL-1β and IL-18 and cell pyroptosis associated with E. coli infection, whereas pre-incubation with L. rhamnosus GR-1 inhibited this increase. Our data indicate that L. rhamnosus GR-1 suppresses activation of ASC-dependent NLRP3 and NLRC4 inflammasomes and production of downstream IL-lβ and IL-18 during E. coli infection. L. rhamnosus GR-1 also inhibited E. coli-induced cell pyroptosis, in part through attenuation of NLRC4 and non-canonical caspase-4 activation independently of ASC

    Uterine Microbiota of Dairy Cows With Clinical and Subclinical Endometritis

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    The objective of this study was to characterize the uterine microbiota of dairy cows with clinical and subclinical endometritis and to identify the potential bacterial genera as well as their interactions associated with uterine disease. Uterine flush samples (n = 27) were collected from 13 healthy, 5 subclinical endometritic (SE), and 9 clinical endometritic (CE) cows at 30 days postpartum. Microbial DNA from uterine flush samples was subjected to sequencing of the 16S rRNA gene on the Illumina MiSeq platform. The uterine microbiota of healthy, SE, and CE cows had similarly complex microbial diversity, and shared 293 of 445 operational taxonomic units. However, endometritic and healthy cows could be discriminated by the relative abundance of bacterial genera. In CE cows, the uterine microbiota was characterized by increased abundance of Fusobacterium and unique presence of Trueperella and Peptoniphilus. For SE cows, known intrauterine pathogens were almost absent and the uterine microbiota was characterized by enrichment of Lactobacillus and Acinetobacter. Analysis of correlations between bacterial genera showed that the uterine microbiota exhibited two co-occurrence groups (i.e., the Lactococcus and the Fusobacterium COGs), indicating that the synergistic effect by co-occurred bacteria may be an important aspect of pathogenesis. Our findings support that common uterine pathogens are not associated with subclinical endometritis at 30 days postpartum and indicate the need of investigating the role of commensal bacteria such as Lactobacillus, and Acinetobacter in the inflammatory process of uterine endometrium

    Magnesium Lithospermate B Protects Cardiomyocytes from Ischemic Injury Via Inhibition of TAB1–p38 Apoptosis Signaling

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    Danshen has been used in traditional Chinese medicine for hundreds of years to treat cardiovascular diseases. However, its precise cardioprotective components and the underlying mechanism are still unclear. In the present study, we demonstrated that in a rat model of acute myocardial infarction, the treatment with magnesium lithospermate B (MLB), the representative component of phenolic acids in Danshen, significantly reduced the infarct size and the blood lactate dehydrogenase level. In contrast, tanshinone IIA, the representative component of lipophilic tanshinones in Danshen, had no such protective effects. Moreover, in the simulated ischemia cell model, MLB treatment considerably increased the cell viability and reduced the sub-G1 population and the apoptotic nuclei, indicating its anti-apoptotic effect. Further mechanism study revealed that the ischemia-induced p38 phosphorylation was abolished by MLB treatment. Interestingly, MLB specifically inhibited the TGFβ-activated protein kinase 1-binding protein 1 (TAB1) mediated p38 phosphorylation through disrupting the interaction between TAB1 and p38, but it did not affect the mitogen-activated protein kinase 3/6 mediated p38 phosphorylation. In conclusion, the present study identifies MLB as an active component of Danshen in protecting cardiomyocytes from ischemic injury through specific inhibition of TAB1–p38 apoptosis signaling. These results indicate TAB1–p38 interaction as a putative drug target in treating ischemic heart diseases

    Construction of a cDNA library and preliminary analysis of the expressed sequence tags of the earthworm Eisenia fetida (Savigny, 1826)

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    Earthworms are useful indicator organisms of soil health and Eisenia fetida have been extensively used as test organisms in ecotoxicological studies. In order to gain insight into the gene expression profiles associated with physiological functions of earthworms, a full‑length enriched cDNA library of the Eisenia fetida genome was successfully constructed using Switching Mechanism at 5\u27End of RNA Template technology. Construction of a cDNA library and analysis of Expressed Sequence Tags (ESTs) are efficient approaches for collecting genomic information and identifying genes important for a given biological process. Furthermore, analysis of the expression abundance of ESTs was performed with the aim of providing genetic and transcriptomic information on the development and regenerative process of earthworms. Phrep and Crossmatch were used to process EST data and a total of 1,140 high‑quality EST sequences were determined by sequencing random cDNA clones from the library. Clustering analysis of sequences revealed a total of 593 unique sequences including 225 contiguous and 368 singleton sequences. Basic Local Alignment Search Tool analysis against the Kyoto Encyclopedia of Genes and Genomes database resulted in 593 significant hits (P‑value \u3c1x10‑8), of which 168 were annotated through Gene Ontology analysis. The STRING database was used to determine relationships among the 168 ESTs, identifying associated genes involved in protein‑protein interactions and gene expression regulation. Based on nucleic acid and protein sequence homology, the mutual relationships between 287 genes could be obtained, which identified a portion of the ESTs as known genes. The present study reports on the construction of a high‑quality cDNA library representative of adult earthworms, on a preliminary analysis of ESTs and on a putative functional analysis of ESTs. The present study is expected to enhance our understanding of the molecular basis underlying the biological development of earthworms

    Quantum key distribution over 658 km fiber with distributed vibration sensing

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    Twin-field quantum key distribution (TF-QKD) promises ultra-long secure key distribution which surpasses the rate distance limit and can reduce the number of the trusted nodes in long-haul quantum network. Tremendous efforts have been made towards implementation of TF-QKD, among which, the secure key with finite size analysis can distribute more than 500 km in the lab and in the field. Here, we demonstrate the sending-or-not-sending TF-QKD experimentally, achieving a secure key distribution with finite size analysis over 658 km ultra-low-loss optical fiber, improve the secure distance record by around 100 km. Meanwhile, in a TF-QKD system, any phase fluctuation due to temperature variation and ambient variation during the channel must be recorded and compensated, and all these phase information can then be utilized to sense the channel vibration perturbations. With our QKD system, we recovered the external vibrational perturbations on the fiber generated by an artificial vibroseis and successfully located the perturbation position with a resolution better than 1 km. Our results not only set a new distance record of QKD, but also demonstrate that the redundant information of TF-QKD can be used for remote sensing of the channel vibration, which can find applications in earthquake detection and landslide monitoring besides secure communication.Comment: 20 pages, 4 figures and 1 tabl
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