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Controlled-source electromagnetic method (CSEM), as a significant geophysical exploration technique, plays a crucial role in imaging subsurface structures. To enhance the accuracy and efficiency of CSEM simulations, this paper introduces a 3D unstructured vector finite element numerical simulation method based on the third-type boundary condition. Vector finite elements are particularly suitable for handling discontinuities in the electric field normal. They automatically satisfy tangential field continuity and zero-divergence requirements, providing a solid foundation for forward modeling in the CSEM. The adoption of the third-type boundary condition aims to reduce computational scale while ensuring higher simulation accuracy. Using this method, we conducted detailed numerical simulations on various models, including layered models, single-anomaly models, composite-anomaly models, and layered-anomaly models. The experimental results demonstrate that the algorithm accurately reproduces the electromagnetic responses of various geological models. It also exhibits superior computational accuracy under low-frequency conditions, outperforming traditional simulation methods. In summary, the 3D unstructured vector finite element numerical simulation method proposed in this study offers an efficient and reliable solution for CSEM, which is of great significance for advancing CSEM technology, especially in inversion techniques and data interpretation. Future work will focus on further optimizing algorithm performance and exploring its application potential in complex geological environments.

Sulfur–metal mass ratios (SMMRs) between sulfur and metal elements (Cu, Pb, Zn, Ag, Fe, etc.) in metal sulfides are fixed in idealized compositions, so they should have a relatively fixed proportion in terms of mass without considering the presence of structural defects such as vacancies or substitution elements. Rock bodies with an SMMR of S far greater than the common metal sulfides may contain additional sulfides of other metals. We studied the Tongshan copper deposit in NE China and calculated the mass transfer of various elements in drill hole ZK611 samples. The data show a S influx of 7160 g/t, a Cu influx of 5469 g/t, and an Fe influx of 8796 g/t in the Cu ore body. Below the Cu ores, the average influx is 18,600 g/t of S, 650 g/t of Cu, and 5360 g/t of Fe, which provides an SMMR far above common mineral sulfide values. Further studies indicated that this rock unit contains fine-grained sphalerite and galenite, and when Zn and Pb are included in the rock SMMR calculations, values closer to the mineral sulfides emerge. These results imply that the coordinating balance relationship of S content with Fe and other ore-forming metals could provide direct information for assessing metallogenic prospects.

Circular RNAs (circRNAs) act crucial roles in the progression of multiple malignancies including osteosarcoma (OS). But, the underlying mechanisms by which hsa_circ_0017311 (circCNST) contributes to the tumorigenesis of OS remain poorly understood. Our present study aimed to explore the role and mechanisms of circCNST in OS tumorigenesis. The differentially expressed circRNAs were identified by the Gene Expression Omnibus database. The association of circCNST with clinicopathological features and prognosis in patients with OS was analyzed by RNA fluorescence in situ hybridization (FISH) and quantitative real-time polymerase chain reaction (PCR) analysis. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation assays, and a xenograft tumor model were conducted to assess the role of circCNST in OS cells in vitro and in vivo. CircCNST-specific binding with miR-421 was confirmed by FISH, luciferase gene report, and RNA immunoprecipitation assays. As a result, we found that the expression levels of circCNST were dramatically increased in OS tissues and cell lines as compared with the adjacent normal tissues, and it was associated with tumor size and poor survival in OS patients. Knockdown of circCNST repressed cell viability, colony formation, and xenograft tumor growth, while restored expression of circCNST reversed these effects. Furthermore, circCNST was colocalized with miR-421 in the cytoplasm and acted as a sponge of miR-421, which attenuated circCNST-induced proliferation-promoting effects in OS cells by targeting SLC25A3. In conclusion, our findings demonstrate that circCNST promotes the tumorigenesis of OS cells by sponging miR-421, and provides a potential biomarker for patients with OS.

The Guodian Fe deposit is representative of the newly discovered Qihe–Yucheng high-grade Fe skarn ore cluster, Luxi Block, eastern North China Craton (NCC). The age of the Pandian Fe deposit remains elusive, which hinders the understanding of its metallogenic tectonic background. Phlogopites are recognized in syn-ore stages, and they are closely associated with magnetite in the Guodian skarn Fe deposit. Here, we carried out 40Ar/39Ar dating of phlogopite, which can place a tight constraint on the timing of Guodian iron mineralization and shed light on the geodynamic framework under which the Guodian Fe deposit formed. Ore-related phlogopite 40Ar/39Ar dating yielded 40Ar/39Ar plateau ages of 131.6 ± 1.7 Ma at 890–1400 °C, with the corresponding isochron age being 131.1 ± 2.6 Ma. These two ages are consistent within the error, indicating that they can represent the formation age of the Guodian iron deposit. The mineralization age overlaps the zircon U-Pb age of 124.4 Ma for ore-related Pandian pluton. This age consistency confirms that the iron skarn mineralization is temporally and likely genetically related to Pandian diorite. The present results, coupled with existing isotopic age data, indicate the Guodian skarn Fe deposit formed contemporaneously with large-scale skarn iron mineralization over the Luxi Block in the Late Mesozoic. The available data demonstrated that the eastern NCC was “destructed” in the Late Mesozoic, as marked by voluminous igneous rocks, faulted-basin formation, high crustal heat flow, and widespread metamorphic core complexes in the eastern part of the NCC. It is thus suggested that the Guodian Fe skarn deposits, together with other deposits of similar ages in the Luxi Block and even in the eastern NCC, were products of this craton destruction. Lithospheric extension and extensive magmatism related to the craton destruction may have provided sufficient heat energy, fluid, chlorine, and Fe for the formation of the Fe deposit.

The Minghuazhen Formation in the Cangdong Sag of the Bohai Bay Basin is a key sedimentary unit for investigating regional provenance evolution, paleoclimate variations, and hydrocarbon potential in Eastern China. This study integrates mineralogical and geochemical analyses to explore sedimentary characteristics. Techniques include X-ray diffraction (XRD), major/trace element compositions, rare earth element (REE) distributions, and organic carbon content. XRD data and elemental ratios (e.g., Al/Ti, Zr/Sc) suggest a predominant felsic provenance, sourced from acidic magmatic rocks. The enrichment with light rare earth elements (LREE: La–Eu) and notable negative Eu anomalies in the REE patterns support the interpretation of a provenance from the Taihangshan and Yanshan Orogenic Belts. Geochemical proxies, such as the Chemical Index of Alteration (CIA) and trace element ratios (e.g., U/Th, V/Cr, Ni/Co), indicate a warm and humid depositional environment, characterized by predominantly oxic freshwater conditions. Organic geochemical parameters, including total organic carbon (TOC), total nitrogen (TN), and C/N ratios, suggest that organic matter primarily originates from aquatic algae and plankton, with C/N values predominantly below 10 and a strong correlation between TOC and TN. The weak correlation between TOC and total carbon (TC) indicates that the organic carbon is mainly biological in origin rather than carbonate-derived. Although the warm and humid climate promoted the production of organic matter, the prevailing oxic conditions hindered its preservation, resulting in a relatively low hydrocarbon generation potential within the Minghuazhen Formation of the Cangdong Sag. These findings provide new insights into the sedimentary evolution and hydrocarbon potential of the Bohai Bay Basin.

The strategic development of selenium-enriched soil cultivation is essential for effective agricultural land management. This research explores the sustainable utilization of selenium-rich soils in Qiongzhong County, Hainan Island. An extensive evaluation was conducted on 7266 surface soil samples, assessing the selenium concentrations, nutrient levels, heavy metals, pH values, and soil organic matter (SOM). In addition, analyses of 70 samples for organochlorine compounds and PAHs were performed. The results indicated average selenium content of 0.46 mg/kg, with 55.2% of the samples surpassing the selenium enrichment threshold of 0.4 mg/kg. According to the GB15618-2018 standards, 127 samples (1.75%) showed medium or high chromium-associated risks. No contamination from organochlorine compounds or PAHs was found, including the 16 priority-controlled PAHs with an average concentration of 30.3 µg/kg, confirming the soil’s high quality. The correlation and factor analysis identified surface enrichment as the main factor influencing selenium accumulation, presenting minimal environmental risks. Consequently, three categories of selenium-rich soil were defined: selenium-rich, pollution-free, and high-nutrient selenium-rich soil. Recommendations based on the soil characteristics and existing agricultural practices were made for the cultivation of selenium-rich vegetables, rubber, and nuts. This study lays a foundation for the sustainable management of selenium-rich soils, providing insights for further research and decision-making to optimize these resources, thus promoting environmental protection and agricultural sustainability.

Circular RNAs (circRNAs) act crucial roles in the progression of multiple malignancies including osteosarcoma (OS). But, the underlying mechanisms by which hsa_(c)irc₀017311 (circCNST) contributes to the tumorigenesis of OS remain poorly understood. Our present study aimed to explore the role and mechanisms of circCNST in OS tumorigenesis. The differentially expressed circRNAs were identified by the Gene Expression Omnibus database. The association of circCNST with clinicopathological features and prognosis in patients with OS was analyzed by RNA fluorescence in situ hybridization (FISH) and quantitative real-time polymerase chain reaction (PCR) analysis. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation assays, and a xenograft tumor model were conducted to assess the role of circCNST in OS cells in vitro and in vivo. CircCNST-specific binding with miR-421 was confirmed by FISH, luciferase gene report, and RNA immunoprecipitation assays. As a result, we found that the expression levels of circCNST were dramatically increased in OS tissues and cell lines as compared with the adjacent normal tissues, and it was associated with tumor size and poor survival in OS patients. Knockdown of circCNST repressed cell viability, colony formation, and xenograft tumor growth, while restored expression of circCNST reversed these effects. Furthermore, circCNST was colocalized with miR-421 in the cytoplasm and acted as a sponge of miR-421, which attenuated circCNST-induced proliferation-promoting effects in OS cells by targeting SLC25A3. In conclusion, our findings demonstrate that circCNST promotes the tumorigenesis of OS cells by sponging miR-421, and provides a potential biomarker for patients with OS.

This paper examines the effect of space and race/ethnicity on labour force participation outcomes among minority and immigrant youth in the Los Angeles metropolitan areas. This research contributes to the spatial mismatch literature by analysing the differences between firstand second-generation immigrants in addition to exploring the role of race and job accessibility on the likelihood of working. It does so by comparing the employment status of comparable youth (16-21 years of age) who reside in central cities, inner-ring suburbs and outer-ring suburbs using 2000 Census PUMS data. Finally, the decision to attend school and to work is modelled in a bivariate probit framework to discover how the correlation across decisions may change the estimated impact of race and space on employment. The results of this study suggest that both space and race play a role in the probability that a youth will work, but that the decision to attend school does not influence the estimated impact of space and race on employment.

Emerging adulthood represents a pivotal phase in human development, demanding heightened attention from individuals, families, and society at large, given its profound impact on the future. In the contemporary landscape, emerging adults grapple with the relentless pace of technological advancement, which permeates various facets of their daily existence. This technological inundation, coupled with the inherent challenges of navigating social transitions and identity formation, underscores the fragility of mental health during this life stage. Research has shown that the intersection of technology and emerging adulthood exacerbates these challenges, necessitating urgent investigation and intervention. Mindfulness has emerged as a promising approach to alleviating anxiety symptoms in emerging adults. This study aims to examine the relationship between mindfulness and technology anxiety and explore the potential mediating role of intolerance of uncertainty. Results from this study indicated that higher levels of dispositional mindfulness were significantly associated with lower levels of technology anxiety. Furthermore, intolerance of uncertainty partially mediated this relationship, suggesting that mindfulness may reduce technology-related anxiety in part by enhancing individuals’ ability to tolerate uncertainty and unpredictability in digital contexts.

The arms race between bacteria and the phages that infect them drives the continual evolution of diverse anti-phage defences. Previously described anti-phage systems have highly varied defence mechanisms 1 – 11 ; however, all mechanisms rely on protein components to mediate defence. Here we report a chemical anti-phage defence system that is widespread in Streptomyces . We show that three naturally produced molecules that insert into DNA are able to block phage replication, whereas molecules that target DNA by other mechanisms do not. Because double-stranded DNA phages are the most numerous group in the biosphere and the production of secondary metabolites by bacteria is ubiquitous 12 , this mechanism of anti-phage defence probably has a major evolutionary role in shaping bacterial communities. Streptomyces secondary metabolites provide a chemical defence against phage predation.