25 research outputs found

    Поперечная зональность и скрытая расслоенность рудного тела Главного Сарановского месторождения, Западный Урал, Россия

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    We present the results of a detailed study of the transversal geochemical zonation in the northern flank of the layered chromitites of the Main Saranovskoe deposit. The precision methods of chemical and mineralogical analysis of the core samples, as well as microprobe studies of chromite grains were used. The primary magmatic two level transverse zonation was established in the ore body. Zonation of the first level is characterized by decrease of Cr2O3 content along with ferrochromite and picrochromite minals, and increase of Al2O3 along with spinel and hercynite minals in the direction from the primary bottom of the ore body to the roof.  Zonation of the second level appears as a hidden stratification within the ore body. It is characterized by a sinusoidal change of the component contents in chrome spinel. Magmatic zoning is complicated by the superposition of two processes: 1) metasomatic metamorphism with the release of the secondary chromemagnetite from chromite and origin of chrome chlorite from primary silicates, 2) hydrothermal processes with the formation of uvarovite-calcite veins. The obtained data allowed to detail the process of chromitite generation and to propose a model of ore formation. It supposes two types of stratification in the deposit: rhythmic with formation of ore layers and hidden within ore bodies.Приведены результаты детального исследования поперечной геохимической и минералогической зональности северного фланга Центрального рудного тела. Впервые применены прецизионные методы химического и минералогического анализа керна, а также микрозондовые исследования зерен хромшпинелидов. Установлена первичная магматическая поперечная зональность рудного тела (в направлении мощности) двух уровней. Зональность первого уровня проявляется в уменьшении в направлении от первичной подошвы рудного тела к кровле содержаний Cr2O3 вместе с хромитовым и пикрохромитовым миналами и в увеличении содержаний Al2O3 вместе со шпинелевым и герцинитовым миналами. Зональность второго уровня отражает скрытую расслоенность в пределах рудного тела и характеризуется синусоидальным изменением содержаний компонентов в хромититах. Первичная магматическая зональность осложнена наложением метасоматического метаморфизма с выделением из хромшпинелида вторичного хроммагнетита и образованием за счет первичных силикатов хромового хлорита и гидротермальных процессов с образованием уваровит-кальцитовых жил. Полученные данные позволили детализировать процесс формирования первичных руд и предложить тектономагматическую модель рудообразования. Она отражает присутствие на месторождении двух видов расслоенности: ритмической межрудной и скрытой внутрирудной

    Lef1 regulates caveolin expression and caveolin dependent endocytosis, a process necessary for Wnt5a/Ror2 signaling during Xenopus gastrulation

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    The activation of distinct branches of the Wnt signaling network is essential for regulating early vertebrate development. Activation of the canonical Wnt/β-catenin pathway stimulates expression of β-catenin-Lef/Tcf regulated Wnt target genes and a regulatory network giving rise to the formation of the Spemann organizer. Non-canonical pathways, by contrast, mainly regulate cell polarization and migration, in particular convergent extension movements of the trunk mesoderm during gastrulation. By transcriptome analyses, we found caveolin1, caveolin3 and cavin1 to be regulated by Lef1 in the involuting mesoderm of Xenopus embryos at gastrula stages. We show that caveolins and caveolin dependent endocytosis are necessary for proper gastrulation, most likely by interfering with Wnt5a/Ror2 signaling. Wnt5a regulates the subcellular localization of receptor complexes, including Ror2 homodimers, Ror2/Fzd7 and Ror2/dsh heterodimers in an endocytosis dependent manner. Live-cell imaging revealed endocytosis of Ror2/caveolin1 complexes. In Xenopus explants, in the presence of Wnt5a, these receptor clusters remain stable exclusively at the basolateral side, suggesting that endocytosis of non-canonical Wnt/receptor complexes preferentially takes place at the apical membrane. In support of this blocking endocytosis with inhibitors prevents the effects of Wnt5a. Thus, target genes of Lef1 interfere with Wnt5a/Ror2 signaling to coordinate gastrulation movements

    Экогеохимическая и биоиндикационная оценка загрязнения малых рек города Березники

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    This paper presents an assessment of the state of the rivers Tolych, Zyryanka and Bygel, flowing within the area with a high technogenic impact (Berezniki, Perm krai). Water quality was evaluated using the integrated geochemical parameters. The characteristics of the macrozoobenthos have been studied as a bioindicator of the ecological state of the reservoir. The formation of the trace element composition and, consequently, water quality is associated with both natural and anthropogenic factors. The obtained metal pollution index (MI) demonstrates the unsuitability of water from rivers Tolych, Zyryanka, and Bygel for domestic purposes.В данном исследовании представлены результаты оценки состояния рек Толыч, Зырянка и Быгель, протекающих в зоне с высокой техногенной нагрузкой (г. Березники, Пермский край). Проведена оценка качества воды с использованием интегральных геохимических показателей. Характеристики макрозообентоса изучены в качестве биоиндикатора экологического состояния водотоков. Формирование микроэлементного состава и, как следствие, качества вод связано как с естественными, так и с антропогенными факторами. В данном исследовании показана важность выбора подхода к оценке качества вод. Результаты расчета индекса нагрузки металлами (MI) демонстрируют непригодность водных биологических ресурсов рек Толыч, Зырянка и Быгель для использования в питании человека

    Prussian Blue Nanozymes with Enhanced Catalytic Activity: Size Tuning and Application in ELISA-like Immunoassay

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    Prussian blue nanozymes possessing peroxidase-like activity gather significant attention as alternatives to natural enzymes in therapy, biosensing, and environmental remediation. Recently, Prussian blue nanoparticles with enhanced catalytic activity prepared by reduction of FeCl3/K3[Fe(CN)6] mixture have been reported. These nanoparticles were denoted as ‘artificial peroxidase’ nanozymes. Our study provides insights into the process of their synthesis. We studied how the size of nanozymes and synthesis yield can be controlled via adjustment of the synthesis conditions. Based on these results, we developed a reproducible and scalable method for the preparation of ‘artificial peroxidase’ with tunable sizes and enhanced catalytic activity. Nanozymes modified with gelatin shell and functionalized with affine molecules were applied as labels in colorimetric immunoassays of prostate-specific antigen and tetanus antibodies, enabling detection of these analytes in the range of clinically relevant concentrations. Protein coating provides excellent colloidal stability of nanozymes in physiological conditions and stability upon long-term storage. © 2022 by the author. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 20-75-00029Funding: This study was supported by the Russian Science Foundation, grant 20-75-00029

    Expression of the T Cell Receptor αβ on a CD123+ BDCA2+ HLA-DR+ Subpopulation in Head and Neck Squamous Cell Carcinoma

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    Human Plasmacytoid Dendritic Cells (PDCs) infiltrating solid tumor tissues and draining lymph nodes of Head and Neck Squamous Cell Carcinoma (HNSCC) show an impaired immune response. In addition to an attenuated secretion of IFN-α little is known about other HNSCC-induced functional alterations in PDCs. Particular objectives in this project were to gain new insights regarding tumor-induced phenotypical and functional alterations in the PDC population. We showed by FACS analysis and RT-PCR that HNSCC orchestrates an as yet unknown subpopulation exhibiting functional autonomy in-vitro and in-vivo besides bearing phenotypical resemblance to PDCs and T cells. A subset, positive for the PDC markers CD123, BDCA-2, HLA-DR and the T cell receptor αβ (TCR-αβ) was significantly induced subsequent to stimulation with HNSCC in-vitro (p = 0.009) and also present in metastatic lymph nodes in-vivo. This subgroup could be functionally distinguished due to an enhanced production of IL-2 (p = 0.02), IL-6 (p = 0.0007) and TGF-β (not significant). Furthermore, after exposure to HNSCC cells, mRNA levels revealed a D-J-beta rearrangement of the TCR-beta chain besides a strong enhancement of the CD3ε chain in the PDC population. Our data indicate an interface between the PDC and T cell lineage. These findings will improve our understanding of phenotypical and functional intricacies concerning the very heterogeneous PDC population in-vivo

    A young boy with a paravertebral mass and symptoms of spinal compression

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