149 research outputs found

    Prediction of Depth Distribution Curve of Dissolution Rates Based on the Undulating Features of Rock Surfaces

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    In karst regions, the drilling into the rock layer is restricted, if the construction site has a thick overburden and a small upper load. The evaluation of karst development features beneath the site becomes a common technical difficulty in building foundation engineering. Drawing on our previous research into the depth distribution features of dissolution rate, this paper collects 1000 plus data on typical karst regions across China, and selects 65 data for detailed analysis. Specifically, the rock surface dissolution features were analyzed on the top and bottom of the strong dissolution zone, and used to set up the control conditions for the top and bottom predictions of the strong dissolution zone. On this basis, the authors provided a prediction method for the depth distribution curve of dissolution rates. The results show that the elevation of 75% dissolution rate can be regarded as the top elevation of the strong dissolution zone at the site, which controls the prediction error within 0.5 m. If the pores and fissures are not so developed at the karst site, the elevation of 15% dissolution rate can be regarded as the bottom elevation of the strong dissolution zone at the site. According to the top and bottom elevations, the authors derived the predicted curve of the depth distribution function for the dissolution rates at each site. The predicted curve basically overlapped the curve and scatterplot of the dissolution rates measured at the site, a sign of reliable prediction. The proposed prediction method for the depth distribution curve of the dissolution rates at karst construction sites mainly applies to the sites with undeveloped to moderately developed pores and fissures. Further research is needed to verify its effectiveness in sites with strongly developed pores and fissures

    Plant mRNAs move into a fungal pathogen via extracellular vesicles to reduce infection

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    Cross-kingdom small RNA trafficking between hosts and microbes modulates gene expression in the interacting partners during infection. However, whether other RNAs are also transferred is unclear. Here, we discover that host plant Arabidopsis thaliana delivers mRNAs via extracellular vesicles (EVs) into the fungal pathogen Botrytis cinerea. A fluorescent RNA aptamer reporter Broccoli system reveals host mRNAs in EVs and recipient fungal cells. Using translating ribosome affinity purification profiling and polysome analysis, we observe that delivered host mRNAs are translated in fungal cells. Ectopic expression of two transferred host mRNAs in B. cinerea shows that their proteins are detrimental to infection. Arabidopsis knockout mutants of the genes corresponding to these transferred mRNAs are more susceptible. Thus, plants have a strategy to reduce infection by transporting mRNAs into fungal cells. mRNAs transferred from plants to pathogenic fungi are translated to compromise infection, providing knowledge that helps combat crop diseases.</p

    Frequent alterations in cytoskeleton remodelling genes in primary and metastatic lung adenocarcinomas

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    The landscape of genetic alterations in lung adenocarcinoma derived from Asian patients is largely uncharacterized. Here we present an integrated genomic and transcriptomic analysis of 335 primary lung adenocarcinomas and 35 corresponding lymph node metastases from Chinese patients. Altogether 13 significantly mutated genes are identified, including the most commonly mutated gene TP53 and novel mutation targets such as RHPN2, GLI3 and MRC2. TP53 mutations are furthermore significantly enriched in tumours from patients harbouring metastases. Genes regulating cytoskeleton remodelling processes are also frequently altered, especially in metastatic samples, of which the high expression level of IQGAP3 is identified as a marker for poor prognosis. Our study represents the first large-scale sequencing effort on lung adenocarcinoma in Asian patients and provides a comprehensive mutational landscape for both primary and metastatic tumours. This may thus form a basis for personalized medical care and shed light on the molecular pathogenesis of metastatic lung adenocarcinoma

    The latest edition of WHO and ELN guidance and a new risk model for Chinese acute myeloid leukemia patients

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    ObjectiveDiagnosis classification and risk stratification are crucial in the prognosis prediction and treatment selection of acute myeloid leukemia (AML). Here, we used a database of 536 AML patients to compare the 4th and 5th WHO classifications and the 2017 and 2022 versions of ELN guidance.MethodsAML patients were classified according to the 4th and 5th WHO classifications, as well as the 2017 and 2022 versions of the European LeukemiaNet (ELN) guidance. Kaplan–Meier curves with log-rank tests were used for survival analysis.ResultsThe biggest change was that 25 (5.2%), 8 (1.6%), and 1 (0.2%) patients in the AML, not otherwise specified (NOS) group according to the 4th WHO classification, were re-classified into the AML-MR (myelodysplasia-related), KMT2A rearrangement, and NUP98 rearrangement subgroups based on the 5th WHO classification. Referring to the ELN guidance, 16 patients in the favorable group, six patients in the adverse group, and 13 patients in the intermediate group based on the 2017 ELN guidance were re-classified to the intermediate and adverse groups based on the 2022 ELN guidance. Regrettably, the Kaplan–Meier curves showed that the survival of intermediate and adverse groups could not be distinguished well according to either the 2017 or 2022 ELN guidance. To this end, we constructed a risk model for Chinese AML patients, in which the clinical information (age and gender), gene mutations (NPM1, RUNX1, SH2B3, and TP53), and fusions (CBFB::MYH11 and RUNX1::RUNX1T1) were included, and our model could help divide the patients into favorable, intermediate, and adverse groups.ConclusionThese results affirmed the clinical value of both WHO and ELN, but a more suitable prognosis model should be established in Chinese cohorts, such as the models we proposed

    siRNAs from miRNA sites mediate DNA methylation of target genes

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    Arabidopsis microRNA (miRNA) genes (MIR) give rise to 20- to 22-nt miRNAs that are generated predominantly by the type III endoribonuclease Dicer-like 1 (DCL1) but do not require any RNA-dependent RNA Polymerases (RDRs) or RNA Polymerase IV (Pol IV). Here, we identify a novel class of non-conserved MIR genes that give rise to two small RNA species, a 20- to 22-nt species and a 23- to 27-nt species, at the same site. Genetic analysis using small RNA pathway mutants reveals that the 20- to 22-nt small RNAs are typical miRNAs generated by DCL1 and are associated with Argonaute 1 (AGO1). In contrast, the accumulation of the 23- to 27-nt small RNAs from the miRNA-generating sites is dependent on DCL3, RDR2 and Pol IV, components of the typical heterochromatic small interfering RNA (hc-siRNA) pathway. We further demonstrate that these MIR-derived siRNAs associate with AGO4 and direct DNA methylation at some of their target loci in trans. In addition, we find that at the miRNA-generating sites, some conserved canonical MIR genes also produce siRNAs, which also induce DNA methylation at some of their target sites. Our systematic examination of published small RNA deep sequencing datasets of rice and moss suggests that this type of dual functional MIRs exist broadly in plants
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