Search

Objective At present, a relatively systematic, mature and rapid excavation construction method for the connection passage construction in hard rock stratum has not been formed yet. Due to the small cross-section and limited operating space in the connection passage, construction with the conventional construction method is less efficient with significant construction risks. Therefore, it is necessary to conduct in-depth study on the technology of controlled blasting in the connection passage of metro shield section in hard rock stratum. Method Taking the connection passage in a shield section of Fuzhou Metro Line 4 as a case study, the controlled blasting technology suitable for this project is proposed. According to the engineering characteristics of the project, the calculating parameters required by the maximum single blast charge for a single-section are set up. In addition, based on the distance between the designed connection passage and the objects to be protected, three levels of maximum single-section charges are calculated, and the schemes for blasting hole design, charge structure design and charge blockage are proposed. Six ground settlement measuring points are selected on the ground above the connection passage, and the settlement curves of the six points during construction are obtained to analyze the influence of blasting on ground settlement. Result & Conclusion The measures of reserving protection layers, treating rock masses as rock walls, shallow hole differential blasting, and digital micro-difference initiation being taken in the process of construction, effectively reduce the explosion impact and blasting vibration, achieving the preset goal of safe blasting and rapid excavation.

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder, but its diagnosis and treatment remain obscure. Non-coding RNAs (ncRNAs), as potential biomarkers, have attracted increasing attention in digestive diseases. Here, we present a comprehensive research status, development trends, and valuable insights in this subject area. The literature search was performed using Web of Science Core Collection. VOSviewer 1.6.20, Citespace 6.2.R4, and Microsoft Excel 2021 were used for bibliometric analysis. A total of 124 articles were included in the analysis. Overall, publication patterns fluctuated. Globally, People's Republic of China, the USA, and Germany were the top three contributors of publications. Guangzhou University of Chinese Medicine, University of California, Mayo Clinic, and University of California, Los Angeles contributed the highest number of publications. The pathways and specific mechanisms by which ncRNAs regulate transcription and translation and thus regulate the pathophysiological processes of IBS are the main research hotspots in this field. We found that microRNA (miRNAs) are intricately involved in the regulation of key pathologies such as viscera sensitivity, intestinal permeability, intestinal mucosal barrier, immunoinflammatory response, and brain-gut axis in the IBS, and these topics have garnered significant attention in research community. Notably, microecological disorders are also associated with IBS pathogenesis, and ncRNA may play an important role in the interactions between host and intestinal flora. This is the first bibliometric study to comprehensively summarize the research hotspots and trends related to IBS and ncRNAs (especially miRNAs). Our findings will help understand the role of ncRNAs in IBS and provide guidance to future studies. [ABSTRACT FROM AUTHOR]

Walleye (Sander vitreus) is a popular sportfish threatened by overexploitation, habitat destruction, and loss of genetic integrity due to non-native walleye stocking. Previous studies have identified a genetically distinct lineage of walleye in the Mobile River Basin, but further work is needed to assess population structure and introgression among this southern lineage and northern populations. Here we generated 2782 genome-wide single nucleotide polymorphisms (SNPs) to characterize the genetic uniqueness of southern walleye. We also found strong evidence for a historical declining population trend with reduced genetic diversity and effective population size in a southern walleye population of conservation importance. A 68-SNP panel was developed for rapid identification of genetic integrity and hybrid classification among northern and southern walleye, enabling us to identify an anthropogenic hybrid zone resulting from the previous introduction of northern walleye into the Black Warrior River drainage, Alabama. Our results highlight the need for conservation management of southern walleye in the Mobile River Basin, with our 68-SNP assay already being implemented in ongoing stream survey and captive breeding programs. Le dore jaune (Sander vitreus), un poisson prise des pecheurs sportifs, est menace par la surexploitation, la destruction d'habitats et la perte d'integrite genetique causee par l'ensemencement de dores non indigenes. Des etudes anterieures ont cerne la presence d'une lignee de dores distincte sur le plan genetique dans le bassin du fleuve Mobile, mais d'autres travaux sont necessaires pour evaluer la structure des populations et l'introgression entre cette lignee meridionale et les populations septentrionales. Nous avons genere 2782 polymorphismes mononucleotidiques (SNPs) pangenomiques dans le but de caracteriser l'unicite genetique des dores du sud. Nous avons aussi releve des preuves solides d'une tendance demographique passee a la baisse accompagnee de reductions de la diversite genetique et de la taille effective de la population dans une population de dores meridionaux d'importance pour la conservation. Un panneau de 68 SNP a ete mis au point pour la determination rapide de l'integrite genetique et la classification d'hybrides au sein des dores du nord et du sud, nous permettant de cerner une region d'hybrides d'origine anthropique resultant de l'introduction passee de dores septentrionaux dans le bassin versant de la riviere Black Warrior (Alabama). Nos resultats soulignent la necessite de la gestion de la conservation des dores meridionaux dans le bassin du fleuve Mobile, notre epreuve de 68 SNP etant deja deployee dans des programmes en cours de releves dans les cours d'eau et d'elevage en captivite. [Traduit par la Redaction], Introduction Freshwater ecosystems are severely threatened by anthropogenic activities such as overexploitation, water pollution, destruction of habitats, and species invasion (Dudgeon et al. 2006). For exploited freshwater fishes of economic [...]

During the excavation of tunnels, the principal stress orientation changes, with a significant impact on the stress distribution, mechanical properties, and plastic zone evolution of rocks surrounding tunnels, causing severe deformation control, and monitoring problems in the stability of tunnels. Currently, biaxial compression tests were conducted to explore the influence of principal stress orientation on mechanical properties of rocks surrounding tunnels. The analytical solution of stress and the model of plastic zone of rocks considering the principal stress orientation and the distance from the excavation boundary were established to reveal the failure mechanism of surrounding rock under different principal stress orientations. With an increase in the angle between the principal stress orientation and the long axis of tunnel, the maximum tangential stress around the tunnel gradually changed to the minimum horizontal principal stress direction, and its value gradually increased, leading to quicker failure of surrounding rocks, and reducing the strength enhancement effect of the same section size of the tunnel. However, the increase in the angle reduced the damage range and the range of the plastic zone around the tunnel and caused the plastic zone to gradually approach the bottom and roof. The maximum depth of the plastic zone remained parallel to or nearly parallel to the minimum horizontal principal stress direction. When the principal stress orientation was kept constant, the maximum depth of the plastic zone shifted to the minimum horizontal principal stress direction with an increase in the vertical principal stress. [ABSTRACT FROM AUTHOR]

Genome assembly can be challenging for species that are characterized by high amounts of polymorphism, heterozygosity, and large effective population sizes. High levels of heterozygosity can result in genome mis‐assemblies and a larger than expected genome size due to the haplotig versions of a single locus being assembled as separate loci. Here, we describe the first chromosome‐level genome for the eastern oyster, Crassostrea virginica. Publicly released and annotated in 2017, the assembly has a scaffold N50 of 54 mb and is over 97.3% complete based on BUSCO analysis. The genome assembly for the eastern oyster is a critical resource for foundational research into molluscan adaptation to a changing environment and for selective breeding for the aquaculture industry. Subsequent resequencing data suggested the presence of haplotigs in the original assembly, and we developed a post hoc method to break up chimeric contigs and mask haplotigs in published heterozygous genomes and evaluated improvements to the accuracy of downstream analysis. Masking haplotigs had a large impact on SNP discovery and estimates of nucleotide diversity and had more subtle and nuanced effects on estimates of heterozygosity, population structure analysis, and outlier detection. We show that haplotig masking can be a powerful tool for improving genomic inference, and we present an open, reproducible resource for the masking of haplotigs in any published genome. [ABSTRACT FROM AUTHOR]