Genetic and Molecular Characterization of Flagellar Assembly in Shewanella oneidensis

Shewanella oneidensis is a highly motile organism by virtue of a polar flagellum. Unlike most flagellated bacteria, it contains only one major chromosome segment encoding the components of the flagellum with the exception of the motor proteins. In this region, three genes encode flagellinsaccording to the original genome annotation. However, we find that only flaA and flaB encode functional filament subunits. Although these two genesare under the control of different promoters, they are actively transcribed and subsequently translated, producing a considerable number of flagellin proteins. Additionally, both flagellins are able to interact with their chaperon FliS and are subjected to feedback regulation. Furthermore, FlaA and FlaB are glycosylated by a pathwayinvolving a major glycosylating enzyme,PseB, in spite of the lack of the majority of theconsensus glycosylation sites. In conclusion, flagellar assembly in S. oneidensis has novel features despite the conservation of homologous genes across taxa

Causal associations between pediatric asthma and united airways disease: a two-sample Mendelian randomization analysis

BackgroundPrior observational research has indicated a potential link between pediatric asthma and united airways disease (UAD). However, these findings could be subject to confounding factors and reverse causation. Therefore, our study utilizes Mendelian randomization (MR) method to further investigate the causal relationship between pediatric asthma and UAD.MethodsWe conducted a comprehensive two-sample Mendelian randomization (MR) analysis to investigate the association between pediatric asthma and seven groups of UAD, including chronic sinusitis, chronic rhinitis, nasopharyngitis and pharyngitis, chronic diseases of tonsils and adenoids, chronic laryngitis and laryngotracheitis, chronic bronchitis, bronchiectasis, chronic obstructive pulmonary disease (COPD). The present study employed a range of methods for two-sample MR analysis, including inverse variance weighted (IVW), MR-Egger regression, Simple mode, weighted median, and weighted models. The conclusion of the MR analysis primarily relies on the IVW results, while other analytical methods are utilized as supplementary evidence to ensure result robustness in this MR analysis. And sensitivity analyses were conducted, including heterogeneity test, horizontal pleiotropy test, MR-PRESSO test, and leave-one-out analysis to validate the results.ResultsThe results of the MR analysis indicate significant causal effects of pediatric asthma on chronic rhinitis, nasopharyngitis and pharyngitis (IVW: OR = 1.15, 95%CI: 1.05–1.26, p-value = 0.003), chronic diseases of tonsils and adenoids (IVW: OR = 1.07, 95%CI: 1.00–1.15, p-value = 0.038), chronic bronchitis (IVW: OR = 1.51, 95%CI: 1.42–1.62, p-value <0.001), bronchiectasis (IVW: OR = 1.51, 95%CI: (1.30–1.75), p-value <0.001), and COPD (IVW: OR = 1.43, 95%CI: 1.34–1.51, p-value <0.001). However, no significant causal association was observed between pediatric asthma and chronic sinusitis (IVW: OR = 1.00, 95%CI: 1.00–1.00, p-value = 0.085), chronic laryngitis and laryngotracheitis (IVW: OR = 1.05, 95%CI: 0.90–1.21, p-value = 0.558).ConclusionOur findings support a potential causal relationship between pediatric asthma and UAD, suggesting that pediatric asthma may be a potential risk factor for various UAD

The long noncoding RNA lncNB1 promotes tumorigenesis by interacting with ribosomal protein RPL35

The majority of patients with neuroblastoma due to MYCN oncogene amplification and consequent N-Myc oncoprotein over-expression die of the disease. Here our analyses of RNA sequencing data identify the long noncoding RNA lncNB1 as one of the transcripts most over-expressed in MYCN-amplified, compared with MYCN-non-amplified, human neuroblastoma cells and also the most over-expressed in neuroblastoma compared with all other cancers. lncNB1 binds to the ribosomal protein RPL35 to enhance E2F1 protein synthesis, leading to DEPDC1B gene transcription. The GTPase-activating protein DEPDC1B induces ERK protein phosphorylation and N-Myc protein stabilization. Importantly, lncNB1 knockdown abolishes neuroblastoma cell clonogenic capacity in vitro and leads to neuroblastoma tumor regression in mice, while high levels of lncNB1 and RPL35 in human neuroblastoma tissues predict poor patient prognosis. This study therefore identifies lncNB1 and its binding protein RPL35 as key factors for promoting E2F1 protein synthesis, N-Myc protein stability and N-Myc-driven oncogenesis, and as therapeutic targets

Investigating the biological roles of ABCE1 in neuroblastoma

Amplification of MYCN is one of the strongest prognostic factors for poor outcome in neuroblastoma, the most common extra-cranial solid tumour in children. With less than 50% of such patients surviving their disease, better therapies are needed. MYC transcription factors up-regulate protein synthesis to drive cancer progression. Since inhibiting protein synthesis is detrimental to the progression of c-MYC driven cancers, targeting this process may offer therapeutic benefit for MYCN-driven neuroblastoma. ABCE1 is a MYC target gene and encodes an ATP-binding cassette protein that powers the dissociation of ribosomes into small and large subunits. This process allows translation re-initiation and continued protein synthesis to provide essential building blocks for cancer growth and metastasis. High tumour ABCE1 expression is correlated with reduced survival of neuroblastoma patients. ABCE1 is thus a putative therapeutic target in MYCN-driven neuroblastoma. Therefore, experiments were conducted to test whether targeting ABCE1-mediated translation can block neuroblastoma progression.ABCE1 suppression by short interfering RNAs impaired the proliferation and migration of MYCN-amplified neuroblastoma cell lines. In contrast, ABCE1 knockdown did not affect these malignant characteristics in neuroblastoma or fibroblast cell lines lacking MYCN amplification. ABCE1 suppression also sensitised neuroblastoma cells to the chemotherapeutics topotecan, mafosfamide and etoposide, further supporting ABCE1 as a potential target in neuroblastoma.Polysome profiling showed that ABCE1 knockdown in MYCN-amplified SK-N-BE(2) neuroblastoma cells reduced translation efficiency. Similar decreases in translation were observed in all other MYCN-amplified cell lines tested, but not in cell lines lacking MYCN amplification. Induction of MYCN expression in the SH-EP Tet21N neuroblastoma cell line substantially increased translation; however, ABCE1 knockdown returned translation to basal levels. Therefore, ABCE1 is required for the elevated translation driven by MYCN dysregulation.In mice xenografted with MYCN-amplified neuroblastoma cells, ABCE1 suppression delayed tumour growth at both subcutaneous and orthotopic sites, prolonging the survival of tumour-bearing mice. This study shows that targeting ABCE1-mediated translation is a promising approach to selectively impair the progression of MYCN-amplified neuroblastoma

Research on the revitalization of the cultural tourism industry in the post-epidemic era——a case study of Guangxi

As a sudden public health event, the COVID-19 epidemic has brought a tremendous impact on the economic and social development of China. Its biggest and most direct impact is in the tertiary industry, especially the cultural tourism industry, which has a more far-reaching impact. This paper takes Guangxi as an example to study the current situation, problems, and future development direction of the cultural tourism industry in the post-epidemic era. The study found that the response to the epidemic in ethnic minority areas represented by Guangxi was timely and rapid, but due to their industrial resilience and the impact of the epidemic, the revitalization of the culture and tourism industry is still facing severe challenges. Therefore, this article put forward the key countermeasure to promote the cultural tourism industry revitalization of ethnic minority areas from list management, elements of development management, project construction, industry integration, and international cooperation, to provide policy recommendations and theoretical basis for the revitalization of the cultural tourism industry in ethnic minority areas

Learning to see high-density random images long-term transmitted in multimode fiber

An improved multi-channel symmetric network (MCSNet) is proposed to reconstruct high-channel-density random images after long-term transmission through multimode fibers (MMFs). Temporal correlation within a period of 25 minutes is calculated to investigate the time-varying characteristics of speckles. The results demonstrated that due to noise accumulation along the MMF path, the quality of speckles deteriorates significantly after long-term transmission. The MCSNet integrates U-Net and ConvNeXt Block, which enables to more fully extract the features of each channel within the entire speckle. After being trained by different random image datasets within the initial moment, tests on random images and realistic scenes of endoscopic surgery after 25 min of transmission are carried out, and all of them demonstrate a near-perfect reconstruction performance and superior scalability, which indicates that MCSNet is suitable for long-term imaging demodulation of endoscopes

Deep learning for highly efficient curvature recognition using fiber scattering speckles

A flexible fiber-optic sensor enabled by deep learning is proposed and experimentally demonstrated for highly efficient curvature sensing application. This sensing modulation system combines a deep optical neural network based on a small training dataset, aiming to simplify speckle data capture and sensor model evaluation. The multimode fiber concatenated with a section of single stress-applying fiber serves as a sensing unit as well as an image transport medium. A type of hybrid scattering speckle images is collected and employed to provide more freedom to identify the bending curvature with and without external disturbances. In a perturbed environment, the trained optical classification model is suitable for the speckle dataset recognition with high accuracy rate of 98.3%. Moreover, the deep-learning-enabled fiber curvature sensor shows great potential for practical applications in real-time structural safety test, including studies on health monitoring of infrastructure equipment and aerospace wings

Study on the Coupling Effect of a Solar-Coal Unit Thermodynamic System with Carbon Capture

Based on the structural theory of thermo-economics, a 600 MW unit was taken as an example. An integration system which uses fuel gas heat and solar energy as a heat source for post-combustion carbon capture was proposed. The physical structure sketch and productive structure sketch were drawn and a thermo-economics model and cost model based on the definition of fuel-product were established. The production relation between units was analyzed, and the composition and distribution of the exergy cost and thermo-economic cost of each unit were studied. Additionally, the influence of the fuel price and equipment investment cost of the thermo-economic cost for each product was studied. The results showed that the main factors affecting the unit cost are the fuel exergy cost, component exergy efficiency, and irreversible exergy cost of each unit, and the main factors affecting the thermo-economics cost are the specific irreversible exergy cost and investment exergy cost. The main factors affecting the thermal economics of solar energy collectors and low-pressure economizers are the invested exergy cost, negentropy exergy cost, and irreversible exergy cost of each unit

Selective comminution and grinding mechanisms of spent carbon anode from aluminum electrolysis using ball and rod mills

The recovery of spent carbon anode (SCA) materials plays important roles in environment protection and resources recycling, while this cannot be efficiently achieved without liberation. In this study, grinding characteristics of spent carbon anode from aluminum electrolysis in both ball mill and rod mill were analyzed, and compared based on the utilization of the selective Fuerstenau upgrading curves. In addition, the different grinding mechanisms of ball and rod milling were evaluated by analyzing the shape factor and surface roughness of the ground samples. Results of mineralogical characterizations indicated that carbon particles (d50 = 46.86 μm) presented in the SCA were closely associated with cryolite particles. At 5 min grinding time, the maximum selective comminution factor (β) values of ball milling and rod milling were 2.00 and 1.63, respectively, indicating a higher degree of selective comminution of SCA was achieved from ball milling. Comparisons of the valuable component content (cv, cum) of -125 μm ground particles and the shape characterizations of 74–125 μm ground particles generated from ball and rod milling manifest that a direct relationship exists between the degree of selective comminution and the grinding mechanism

A Crp-Dependent Two-Component System Regulates Nitrate and Nitrite Respiration in <em>Shewanella oneidensis</em>

<div><p>We have previously illustrated the nitrate/nitrite respiratory pathway of <em>Shewanella oneidensis</em>, which is renowned for its remarkable versatility in respiration. Here we investigated the systems regulating the pathway with a reliable approach which enables characterization of mutants impaired in nitrate/nitrite respiration by guaranteeing biomass. The <em>S. oneidensis</em> genome encodes an <em>Escherichia coli</em> NarQ/NarX homolog SO3981 and two <em>E. coli</em> NarP/NarL homologs SO1860 and SO3982. Results of physiological characterization and mutational analyses demonstrated that <em>S. oneidensis</em> possesses a single two-component system (TCS) for regulation of nitrate/nitrite respiration, consisting of the sensor kinase SO3981(NarQ) and the response regulator SO3982(NarP). The TCS directly controls the transcription of <em>nap</em> and <em>nrfA</em> (genes encoding nitrate and nitrite reductases, respectively) but regulates the former less tightly than the latter. Additionally, phosphorylation at residue 57 of SO3982 is essential for its DNA-binding capacity. At the global control level, Crp is found to regulate expression of <em>narQP</em> as well as <em>nap</em> and <em>nrfA</em>. In contrast to NarP-NarQ, Crp is more essential for <em>nap</em> rather than <em>nrfA</em>.</p> </div