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BACKGROUND With the increasing demand for scandium resources, countries around the world have carried out scandium metallogenic mechanism research and prospecting in recent years. One of the key research contents is to clarify the occurrence characteristics of scandium. According to previous studies, scandium mainly exists in the form of isomorphism and ion adsorption in various scandium deposits. At present, more than 800 kinds of scandium-bearing minerals have been found. The scandium resource of the Bayan Obo deposit is large, which has the characteristics of dispersed distribution and low content. Scandium enters other minerals in the form of isomorphism and no independent scandium mineral is found. Due to the limitation of testing technology and sampling, there is no accurate quantitative research to systematically explore the occurrence characteristics of scandium in different minerals in the Bayan Obo deposit. Therefore, the identification of the main scandium-bearing minerals is insufficient, which is not conducive to further exploration of the enrichment mechanism of scandium and the utilization of scandium resources in the deposit. OBJECTIVES To understand the occurrence of Sc in different minerals of the Bayan Obo deposit. METHODS 34 kinds of minerals in the Bayan Obo deposit were systematically determined by electron probe microanalyzer (EPMA) technology. RESULTS The test results showed that the average scandium content (Sc2O3) in 6 minerals was more than 0.100%. They were samarskite (with average Sc2O3 content of 2.485%), columbite (1.263%), manganocolumbite (0.251%), dark purple fluorite (0.181%), thorianite (0.145%) and Y-rich aeschynite (0.124%) from high to low. Samarskite had the highest scandium content (3.093%). The content of scandium in 16 minerals ranged from 0.004% to 0.067%, which were fergusonite (with average Sc2O3 content of 0.067%), alkaline amphibole (0.062%), ferrothorite (0.060%), pyrochlore (0.049%), fersmite (0.031%), bastnaesite (0.028%), apatite (0.028%), britholite (0.025%), monazite (0.023%), aegirine (0.02%), biotite (0.019%), humite (0.011%), fergusonite-(Ce) (0.008%), feldspar (0.007%), magnetite (0.005%), albite (0.004%). Scandium was not detected in the other 12 minerals. CONCLUSIONS Samarskite has the highest scandium content in the deposit, and the 6 main scandium-bearing minerals are samarskite, columbite, manganocolumbite, dark purple fluorite, thorianite and Y-rich aeschynite. Among the 34 minerals, the content of scandium in 22 minerals is higher than the detection limit of EPMA, and scandium is distributed in a dilute manner. The occurrence of scandium is related to titanium, yttrium and thorium, and the correlation coefficients are 0.869, 0.835 and 0.720, respectively. Scandium is closely related to niobium minerals such as columbite, manganocolumbite, fersmite and Y-rich aeschynite. It can be considered to comprehensively utilize scandium and niobium resources at the same time.

Bayan Obo deposit is famous for its rare earth, niobium, iron and other resources. In order to make good use of these resources, it is necessary to accurately identify the minerals. At present, the most basic mineral identification method is microscopic observation. However, the mineral composition of Bayan Obo deposit is complex and the particle size is fine. The optical characteristics of many minerals are not obvious or even similar under the microscope, which requires high personnel ability and experience and leads to the low efficiency. XRD analysis has its own advantages in the face of these difficulties. But the traditional XRD analysis requires powder sample. In order to carry out XRD analysis on the area observed under the supplemented while the results were compared. It is found that; 1) The XRD analysis results are basically consistent with the microscopic identification results. Through the appropriate placement of the microprobe slice, the area of XRD analysis is similar to the observation area under the microscope while the efficiency is higher. 2) XRD analysis is helpful to identify fine-grained minerals and similar minerals, and to provide reliable results for special minerals. 3) The strong metaplasia will lead to the omission of metaplasia minerals in XRD analysis. 4) The use of microprobe slice in Bayan Obo deposit is conducive to the subsequent joint analysis of multiple methods. It can give better play to the advantages of various equipment and form systematic and accurate identification results.microscope, microprobe slice is prepared as sample, which is a challenge to the accuracy of XRD analysis. To test the feasibility of this method, six samples from Bayan Obo main ore were collected and made into microprobe slices for microscope observation and XRD analysis. The EDS and EPMA tests were [ABSTRACT FROM AUTHOR]

Microtubules are vital components of the cytoskeleton. Their plus ends are dynamic and respond to changes in cell morphology, whereas the minus ends are stable and serve a crucial role in microtubule seeding and maintaining spatial organization. In mammalian cells, the calmodulin-regulated spectrin-associated proteins (CAMSAPs), play a key role in directly regulating the dynamics of non-centrosomal microtubules minus ends. However, the molecular mechanisms are not yet fully understood. Our study reveals that CAMSAP3 forms dimers through its C-terminal α-helix; this dimerization not only enhances the microtubule-binding affinity of the CKK domain but also enables the CKK domain to regulate the dynamics of microtubules. Furthermore, CAMSAP3 also specializes in decorating at the minus end of microtubules through the combined action of the microtubule-binding domain (MBD) and the C-terminal α-helix, thereby achieving dynamic regulation of the minus ends of microtubules. These findings are crucial for advancing our understanding and treatment of diseases associated with non-centrosomal microtubules., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Microtubule networks support many cellular processes and exhibit a highly ordered architecture. However, due to the limited axial resolution of conventional light microscopy, the structural features of these networks cannot be resolved in three-dimensional (3D) space. Here, we used customized ultra-high-resolution interferometric single-molecule localization microscopy to characterize the microtubule networks in Caco2 cells. We found that the calmodulin-regulated spectrin-associated proteins (CAMSAPs) localize at a portion of microtubule intersections. Further investigation showed that depletion of CAMSAP2 and CAMSAP3 leads to the narrowing of the inter-microtubule distance. Mechanistically, CAMSAPs recognize microtubule defects, which often occur near microtubule intersections, and then recruit katanin to remove the damaged microtubules. Therefore, the CAMSAP-katanin complex is a regulatory module for the distance between microtubules. Taken together, our results characterize the architecture of cellular microtubule networks in high resolution and provide molecular insights into how the 3D structure of microtubule networks is controlled., (© The Author(s) (2023). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, CEMCS, CAS.)

WDR62 is the second most common genetic alteration associated with microcephaly. It has been shown that Wdr62 is required for germ cell meiosis initiation in mice, and the majority of male germ cells are lost in the meiotic defect of first wave spermatogenesis in Wdr62 mutants. Strikingly, in this study, we found that the initiation of meiosis following spermatogenesis was not affected and the germ cells were gradually repopulated at later developmental stages. However, most germ cells were arrested at metaphase of meiosis I and no mature sperm were detected in epididymides. Further, this study demonstrated that metaphase I arrest of Wdr62 -deficient spermatocytes was caused by asymmetric distribution of the centrosome and aberrant spindle assembly. Also, mechanistic studies demonstrated that WDR62 interacts with centrosome-associated protein CEP170, and deletion of Wdr62 causes downregulation of the CEP170 protein, which in turn leads to the aberrant spindle assembly. In summary, this study indicates that the meiosis of first wave spermatogenesis and the following spermatogenesis started from spermatogonium is probably regulated by different mechanisms. We also demonstrated a new function of WDR62 in germ cell meiosis, through its interaction with CEP170., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

The adherens junction (AJ) is an element of the cell-cell junction in which cadherin receptors bridge the neighboring plasma membranes via their homophilic interactions. Cadherins associate with cytoplasmic proteins, called catenins, which in turn bind to cytoskeletal components, such as actin filaments and microtubules. These molecular complexes further interact with other proteins, including signaling molecules, rendering the AJs into highly dynamic and regulatable structures. The AJs of such nature contribute to the physical linking of cells, as well as to the regulation of cell-cell contacts, which is essential for morphogenesis and remodeling of tissues and organs. Thus, elucidating the molecular architecture of the AJs and their regulatory mechanisms are crucial for understanding how the multicellular system is organized.