225 research outputs found

    Coarse-grained Soft-Clusters Remain non-Diffusing in the Melt State

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    Melts of 3-dimensional dendritic beads-springs, namely coarse-grained soft-clusters, are studied by molecular dynamics simulations. The goal is to elucidate the unique dynamics of giant molecules, or generally speaking, 3-dimensional architectured polymers. When constituted by more than the critical number around 200 beads, soft-clusters cannot diffuse or relax far above their glass transition temperature, although relaxation can happen on the level of beads. Each soft-cluster can only rotate in the cage formed by neighboring soft-clusters. Such a non-diffusing state would transform to the liquid state at exceptionally high temperature, e.g. 10 times the glass transition temperature. Agreeing with experiments, 3D hierarchies lead to unique dynamics, especially their divergent relaxation times with the number of beads. These unique dynamics are in sharp contrast with 1-dimensional chain-like polymers. We name such a special state as 'cooperative glass', because of the 'cooperation' of the 3D-connected beads. The design of soft-clusters may also resemble cooperative rearranging regions where cooperativeness is contributed by low temperature, thus offer further insights into the glass problem

    Effects of Acrylamide on the Activity and Structure of Human Brain Creatine Kinase

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    Acrylamide is widely used worldwide in industry and it can also be produced by the cooking and processing of foods. It is harmful to human beings, and human brain CK (HBCK) has been proposed to be one of the important targets of acrylamide. In this research, we studied the effects of acrylamide on HBCK activity, structure and the potential binding sites. Compared to CKs from rabbit, HBCK was fully inactivated at several-fold lower concentrations of acrylamide, and exhibited distinct properties upon acrylamide-induced inactivation and structural changes. The binding sites of acrylamide were located at the cleft between the N- and C-terminal domains of CK, and Glu232 was one of the key binding residues. The effects of acrylamide on CK were proposed to be isoenzyme- and species-specific, and the underlying molecular mechanisms were discussed

    Inland post-glacial dispersal in East Asia revealed by mitochondrial haplogroup M9a'b

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    <p>Abstract</p> <p>Background</p> <p>Archaeological studies have revealed a series of cultural changes around the Last Glacial Maximum in East Asia; whether these changes left any signatures in the gene pool of East Asians remains poorly indicated. To achieve deeper insights into the demographic history of modern humans in East Asia around the Last Glacial Maximum, we extensively analyzed mitochondrial DNA haplogroup M9a'b, a specific haplogroup that was suggested to have some potential for tracing the migration around the Last Glacial Maximum in East Eurasia.</p> <p>Results</p> <p>A total of 837 M9a'b mitochondrial DNAs (583 from the literature, while the remaining 254 were newly collected in this study) pinpointed from over 28,000 subjects residing across East Eurasia were studied here. Fifty-nine representative samples were further selected for total mitochondrial DNA sequencing so we could better understand the phylogeny within M9a'b. Based on the updated phylogeny, an extensive phylogeographic analysis was carried out to reveal the differentiation of haplogroup M9a'b and to reconstruct the dispersal histories.</p> <p>Conclusions</p> <p>Our results indicated that southern China and/or Southeast Asia likely served as the source of some post-Last Glacial Maximum dispersal(s). The detailed dissection of haplogroup M9a'b revealed the existence of an inland dispersal in mainland East Asia during the post-glacial period. It was this dispersal that expanded not only to western China but also to northeast India and the south Himalaya region. A similar phylogeographic distribution pattern was also observed for haplogroup F1c, thus substantiating our proposition. This inland post-glacial dispersal was in agreement with the spread of the Mesolithic culture originating in South China and northern Vietnam.</p

    The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

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    We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

    A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

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    We established a method on measuring the \dzdzb mixing parameter yy for BESIII experiment at the BEPCII e+ee^+e^- collider. In this method, the doubly tagged ψ(3770)D0D0\psi(3770) \to D^0 \overline{D^0} events, with one DD decays to CP-eigenstates and the other DD decays semileptonically, are used to reconstruct the signals. Since this analysis requires good e/πe/\pi separation, a likelihood approach, which combines the dE/dxdE/dx, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of yy to be 0.007 based on a 20fb120fb^{-1} fully simulated MC sample.Comment: 6 pages, 7 figure

    Serological Thymidine Kinase 1 is a Biomarker for Early Detection of Tumours—A Health Screening Study on 35,365 People, Using a Sensitive Chemiluminescent Dot Blot Assay

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    Serological thymidine kinase 1 (STK1) is a reliable proliferation marker for prognosis, monitoring tumour therapy, and relapse. Here we investigated the use of STK1 in health screening for early detection of pre-malignant and malignant diseases. The investigation was based on 35,365 participants in four independent health screening studies in China between 2005–2011. All participants were clinically examined. The concentration of STK1 was determined by a sensitive chemiluminescent dot blot ECL assay. The ROCvalue of the STK1 assay was 0.96. At a cut-off STK1 value of 2.0 pM, the likelihood (+) value was 236.5, and the sensitivity and the specificity were 0.78 and 0.99, respectively. The relative number of city-dwelling people with elevated STK1 values (≥2.0 pM) was 0.8% (198/26,484), while the corresponding value for the group of oil-field workers was 5.8% (514/8,355). The latter group expressed significantly higher frequency of refractory anaemia, fatty liver, and obesity, compared to the city dwellers, but no cases of breast hyperplasia or prostate hyperplasia. Furthermore, people working in oil drilling/oil transportation showed higher STK1 values and higher frequency of pre-malignancies and benign diseases than people working in the oil-field administration. In the STK1 elevated group of the city-dwelling people, a statistically significantly higher number of people were found to have malignancies, pre-malignancies of all types, moderate/severe type of hyperplasia of breast or prostate, or refractory anaemia, or to be at high risk for hepatitis B, compared to people with normal STK1 values (<2.0 pM). No malignancies were found in the normal STK1 group. In the elevated STK1 group 85.4% showed diseases linked to a higher risk for pre-/early cancerous progression, compared to 52.4% of those with normal STK1 values. Among participants with elevated STK1 values, 8.8% developed new malignancies or progress in their pre-malignancies within 5 to 72 months, compared to 0.2% among people with normal STK1 values. People who showed elevated STK1 values were at about three to five times higher risk to develop malignancies compared to a calculated risk based on a cancer incidence rate of 0.2–0.3%. We conclude that serological TK1 protein concentration is a reliable marker for risk assessment of pre/early cancerous progression

    Wolfberry genomes and the evolution of Lycium (Solanaceae)

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    AbstractWolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of Solanaceae have been subjected to genome sequencing, thus far, no genome sequences of woody representatives have been available. Here, we sequenced the genomes of 13 perennial woody species of Lycium, with a focus on Lycium barbarum. Integration with other genomes provides clear evidence supporting a whole-genome triplication (WGT) event shared by all hitherto sequenced solanaceous plants, which occurred shortly after the divergence of Solanaceae and Convolvulaceae. We identified new gene families and gene family expansions and contractions that first appeared in Solanaceae. Based on the identification of self-incompatibility related-gene families, we inferred that hybridization hotspots are enriched for genes that might be functioning in gametophytic self-incompatibility pathways in wolfberry. Extremely low expression of LOCULE NUBER (LC) and COLORLESS NON-RIPENING (CNR) orthologous genes during Lycium fruit development and ripening processes suggests functional diversification of these two genes between Lycium and tomato. The existence of additional flowering locus C-like MADS-box genes might correlate with the perennial flowering cycle of Lycium. Differential gene expression involved in the lignin biosynthetic pathway between Lycium and tomato likely illustrates woody and herbaceous differentiation. We also provide evidence that Lycium migrated from Africa into Asia, and subsequently from Asia into North America. Our results provide functional insights into Solanaceae origins, evolution and diversification.</jats:p

    The Euscaphis japonica genome and the evolution of malvids

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    Malvids is one of the largest clades of rosids, includes 58 families and exhibits remarkable morphological and ecological diversity. Here, we report a high-quality chromosome-level genome assembly for Euscaphis japonica, an early-diverging species within malvids. Genome-based phylogenetic analysis suggests that the unstable phylogenetic position of E. japonica may result from incomplete lineage sorting and hybridization event during the diversification of the ancestral population of malvids. Euscaphis japonica experienced two polyploidization events: the ancient whole genome triplication event shared with most eudicots (commonly known as the c event) and a more recent whole genome duplication event, unique to E. japonica. By resequencing 101 samples from 11 populations, we speculate that the temperature has led to the differentiation of the evergreen and deciduous of E. japonica and the completely different population histories of these two groups. In total, 1012 candidate positively selected genes in the evergreen were detected, some of which are involved in flower and fruit development. We found that reddening and dehiscence of the E. japonica pericarp and long fruit-hanging time promoted the reproduction of E. japonica populations, and revealed the expression patterns of genes related to fruit reddening, dehiscence and abscission. The key genes involved in pentacyclic triterpene synthesis in E. japonica were identified, and different expression patterns of these genes may contribute to pentacyclic triterpene diversification. Our work sheds light on the evolution of E. japonica and malvids, particularly on the diversification of E. japonica and the genetic basis for their fruit dehiscence and abscission.DATA AVAILABILITY STATEMENT : All sequences described in this manuscript have been submitted to the National Genomics Data Center (NGDC). The raw whole-genome data of E. japonica have been deposited in BioProject/GSA (https://bigd.big.ac.cn/gsa.) under the accession codes PRJCA005268/CRA004271, and the assembly and annotation data have been deposited at BioProject/GWH (https://bigd.big.ac.cn/gwh) under the accession codes PRJCA005268/GWHBCHS00000000. The raw transcriptomes data of E. japonica have been deposited in BioProject/GSA (https://bigd.big.ac.cn/gsa.) under the accession codes PRJCA005298/CRA004272.SUPPLEMENTARY MATERIAL 1: Supplementary Note 1. Chromosome number assessment. Supplementary Note 2. Whole-genome duplication identification and dating. Supplementary Note 3. Observation of E. japonica seed dispersal. Supplementary Note 4. Determination of pentacyclic triterpene substances. Figure S1. Cytogenetic analysis of E. japonica. Figure S2. Genome size and heterozygosity of E. japonica estimation using 17 k-mer distribution. Figure S3. Interchromosomal of Hi-C chromosome contact map of E. japonica genome. Figure S4. Gene structure prediction results of E. japonica and other species. Figure S5. Venn diagram shows gene families of malvids. Figure S6. Phylogenetic tree constructed by chloroplast genomes from 17 species. Figure S7. Concatenated- and ASTRAL-based phylogenetic trees. Figure S8. Ks distribution in E. japonica. Figure S9. Distributions of synonymous substitutions per synonymous site (Ks) of one-to-one orthologs identified between E. japonica and P. trichocarpa and V. vinifera. Figure S10. Population structure plot. Figure S11. Fixation index (FST) heat map among E. japonica populations. Figure S12. Phylogenetic analysis of MADS-box genes from O. sativa, A. thaliana, E. japonica, and T. cacao. Figure S13. Observation the fruit development. Figure S14. Animal seed dispersal. Figure S15. Anthocyanin biosynthesis in E. japonica fruits. Figure S16. Carotenoid accumulation and the chlorophyll degradation in E. japonica fruits. Figure S17. Expression profile of fruit dehiscence-related genes. Figure S18. Phylogenetic tree of DELLA genes obtained from six malvids species. Figure S19. Phylogenetic tree of CAD genes obtained from seven malvids species. Figure S20. Expression pattern of fruit abscission-related genes. Figure S21. Structure of pentacyclic triterpene compounds separated from Euscaphis. Figure S22. Phylogenetic tree of HMGR gene in plants. Figure S23. Phylogenetic tree of P450s gene family obtained from A. thaliana and E. japonica.SUPPLEMENTARY MATERIAL 2: Table S1. Assembled statistics of E. japonica genome. Table S2. Evaluation of E. japonica genome assembly. Table S3. Chromosome length of E. japonica. Table S4. Prediction of gene structures of the E. japonica genome. Table S5. Statistics on the function annotation of the E. japonica genome. Table S6. Non-coding RNA annotation results of E. japonica genome. Table S7. BUSCO assessment of the E. japonica annotated genome. Table S8. Statistic of repeat sequence in E. japonica genome. Table S9. Gene-clustering statistics for 17 species. Table S10. KEGG enrichment result of unique genes families of E. japonica. Table S11. Gene Ontology (GO) and KEGG enrichment result of significant shared by malvids species gene families. Table S12. Gene Ontology (GO) and KEGG enrichment result of significant expansion of E. japonica gene families. Table S13. Gene Ontology (GO) enrichment result of significant contraction of E. japonica gene families. Table S14. Statistical sampling population information. Table S15. Statistics population resequencing information. Table S16. Statistical nucleotide polymorphisms in the populations. Table S17. Candidate positive selection genes (PSGs) in the evergreen population. Table S18. Candidate positive selection genes (PSGs) in the deciduous population. Table S19. Gene Ontology (GO) enrichment result of significant PSGs in the evergreen population. Table S20. List of MADS-box genes identified in E. japonica. Table S21. Genes involved in anthocyanin biosynthesis, carotenoid biosynthesis, and chlorophyll degradation. Table S22. Identification fruit dehiscence-related genes in E. japonica. Table S23. Genes related to lignin synthesis that are highly expressed during pericarp dehiscence. Table S24. Gene expression levels (FPKMs) of fruit abscission-related genes in pericarp. Table S25. Triterpene compounds separated from Euscaphis. Table S26. Number of putative pentacyclic triterpene-related genes in the malvids species. Table S27. Identified pentacyclic triterpene synthesis-related genes in E. japonica genome. Table S28. Statistical simple sequence repeat.Fund for Excellent Doctoral Dissertation of Fujian Agriculture and Forestry University, China; Fujian Provincial Department of Science E. japonica Evolution and Selection of Ornamental Medicinal Resources, China; the Project of Forestry Peak Discipline at Fujian Agriculture and Forestry University, China; the Collection, Development and Utilization of Eascaphis konlshli Germplasm Resources; the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program and from Ghent University.https://onlinelibrary.wiley.com/journal/1365313xam2022BiochemistryGeneticsMicrobiology and Plant Patholog

    Worldwide tests of generic attractants, a promising tool for early detection of non-native cerambycid species

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    A large proportion of the insects which have invaded new regions and countries are emerging species, being found for the first time outside their native range. Being able to detect such species upon arrival at ports of entry before they establish in non-native countries is an urgent challenge. The deployment of traps baited with broad-spectrum semiochemical lures at ports-of-entry and other high-risk sites could be one such early detection tool. Rapid progress in the identification of semiochemicals for cerambycid beetles during the last 15 years has revealed that aggregation-sex pheromones and sex pheromones are often conserved at global levels for genera, tribes or subfamilies of the Cerambycidae. This possibly allows the development of generic attractants which attract multiple species simultaneously, especially when such pheromones are combined into blends. Here, we present the results of a worldwide field trial programme conducted during 2018-2021, using traps baited with a standardised 8-pheromone blend, usually com-plemented with plant volatiles. A total of 1308 traps were deployed at 302 sites covering simultaneously or sequentially 13 European countries, 10 Chinese provinces and some regions of the USA, Canada, Australia, Russia (Siberia) and the Caribbean (Martinique). We intended to test the following hypotheses: 1) if a species is regularly trapped in significant numbers by the blend on a continent, it increases the prob-ability that it can be detected when it arrives in other countries/continents and 2) if the blend exerts an effective, generic attraction to multiple species, it is likely that previously unknown and unexpected spe-cies can be captured due to the high degree of conservation of pheromone structures within related taxa. A total of 78,321 longhorned beetles were trapped, representing 376 species from eight subfamilies, with 84 species captured in numbers greater than 50 individuals. Captures comprised 60 tribes, with 10 tribes including more than nine species trapped on different continents. Some invasive species were captured in both the native and invaded continents. This demonstrates the potential of multipheromone lures as ef-fective tools for the detection of 'unexpected' cerambycid invaders, accidentally translocated outside their native ranges. Adding new pheromones with analogous well-conserved motifs is discussed, as well as the limitations of using such blends, especially for some cerambycid taxa which may be more attracted by the trap colour or other characteristics rather than to the chemical blend
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