Cryo-Electron Microscopy in the Study of Antiviral Innate Immunity.

Cryo-electron microscopy is a powerful methodology in structural biology and has been broadly used in high-resolution structure determination for challenging samples, which are not readily available for traditional techniques. In particular, the strength of super macro-complexes and the lack of a need for crystals for cryo-EM make this technique feasible for the structural study of complexes involved in antiviral innate immunity. This chapter presents detailed information and experimental procedures of Cryo-EM for determining the structures of the complexes using STING as an example. The procedures included a sample quality check, high-resolution data acquisition, and image processing for Cryo-EM 3D structure determination.

Spatio-temporal composition of aquatic birds communityin Juluapan Lagoon, Colima, Mexican Central Pacific / Composición espacio-temporal de las aves acuáticas en la laguna Juluapan, Colima, en el Pacífico Central Mexicano

Abstract Introduction: Aquatic birds (AB) are usually associated with wetlands, which provide refuge, food, and/or nesting sites for resident and migratory species. Despite their ecological importance, there is little knowledge on AB in some tropical environments, such as those found on the Colima coast. Objective: To investigate the spatial and temporal composition of the AB community in Juluapan Lagoon, Colima, Central Mexican Pacific. Methods: Monthly counts were conducted between June 2017 and May 2018 during low-tide conditions to record habitat use by AB. Species richness and bird counts were obtained to compare sampling areas; mean richness and number of individuals were compared between seasons. Results: We detected 53 species and 5 750 individuals. The highest species richness and relative abundance values were obtained in winter at the lagoon area farthest from the connection with the marine system, where anthropogenic activity is lower. Diversity was greater in zones 2 and 3 in spring, summer, and fall. Muddy flats were the most used environment, and the most frequent activity was resting. Nesting activity was only recorded in the middle of the lagoon at the mangrove during spring. "Shorebirds" and "waders" were the most dominant groups in the bird community of the Juluapan lagoon. Conclusions: This coastal wetland is a site of great biological importance for aquatic birds; thus, conservation measures should be implemented, and there should be a continuous study of the effects of anthropogenic pressure.

Resumen Introducción: Las aves acuáticas (AA) son usualmente relacionadas a los humedales debido a que éstos funcionan como sitios de refugio, alimentación y anidación de diferentes especies residentes y migratorias. Sin embargo, el conocimiento sobre las aves acuáticas en algunos humedales es nulo. Objetivo: Investigar la composición espacio-temporal de la comunidad de AA en la laguna Juluapan, Colima, en el Pacífico Central Mexicano. Métodos: Entre junio de 2017 y mayo de 2018 se llevaron a cabo conteos mensuales en condiciones de marea baja para registrar el uso de hábitat de las AA. Se obtuvieron valores de riqueza de especies y número de individuos para realizar comparaciones entre zonas de muestreo, así como el promedio del número de especies y número de individuos para comparaciones entre temporadas. Resultados: Se registraron un total de 53 especies y 5 750 individuos. Los valores de riqueza de especies y densidad de individuos fueron más altos durante invierno, en la zona más alejada al ambiente marino, donde la actividad antropogénica es menor. La diversidad tuvo valores más altos en la zona 2 y 3, durante primavera, verano y otoño. El ambiente más explotado por las aves fueron las planicies lodosas; y el descanso fue la actividad más frecuente. Asimismo, la actividad de anidación sólo se registró en el manglar de la zona media durante primavera. Las "aves playeras" y "aves zancudas" fueron los grupos más predominantes en la comunidad de aves de la laguna Juluapan. Conclusiones: Este humedal costero es un sitio de gran importancia biológica para aves acuáticas, por lo que resulta necesario la implementación de medidas de conservación, así como el estudio de los efectos por la presión antropogénica.

Driving forces of herbaceous species diversity in natural broadleaf forests from in Maoershan from Northeast China.

The understory herbaceous flora plays a pivotal role in regulating the structural stability, complexity, and ecological function of forest communities. It is crucial to investigate the impact of the intricate connections between these factors and the forces driving the diversity of herbaceous species within natural broadleaf understory forests can assist forest managers in developing optimal forest structure optimization techniques, allowing them to adjust the forest species diversity. In this study, Pearson correlation analysis, conventional correlation analysis, and multiple linear regression were employed to elucidate the relationship between stand structure, soil nutrients, and understory herbaceous species richness in natural broadleaved forests. Structural equation modeling was utilized to ascertain the influence of multiple factors on understory herbaceous species diversity and to evaluate the underlying pathways. The results indicated a significant negative correlation between stand closure and the Simpson's and Shannon-Wiener's indices, and between the mixing degree and the Pielou evenness index, Simpson's index, and Shannon-Wiener's index (p<0.05). Furthermore, a significant positive correlation was observed between soil nutrients, specifically organic matter and total phosphorus, and the Pielou evenness index and Shannon-Wiener's index (p<0.05). It was found that total phosphorus was significantly positively correlated with both the Pielou evenness index and the Shannon-Wiener index (p<0.05). The correlation coefficients of the first group of typical variables in the typical correlation analysis were 0.498 and 0.585, respectively (p<0.05). From the set of typical variables of stand structure, it can be seen that the Hegyi competition index and the canopy density affected the diversity of understory herbaceous plants. The composite index demonstrated the greatest impact, with loadings of 0.872 and -0.506, respectively. The Simpson and Shannon-Wiener indices exhibited the most sensitive loadings of -0.441 and -0.408, respectively. The soil nutrients of SOM and TN affected the understory herbaceous plant species diversity composite index, with greater loadings of -0.184 and 1.002, respectively. The path coefficient of the understory herbaceous diversity stand structure was 0.35. The path coefficient with soil nutrient content was found to be 0.23 following structural equation analysis and the path coefficient between stand structure and soil nutrient content was 0.21, which indirectly affect the diversity of understory herbaceous species. To enhance the diversity of herbaceous species, it is recommended that the canopy density and tree density of the upper forest be reduced appropriately, while the degree of mixing and the level of spatial distribution of trees be adjusted in a manner that maintains a reasonable stand structure. Furthermore, a comprehensive forest management program for improving soil nutrients should be considered.

Race and ethnic differences in step- versus biological parent support to adult children.

Objective: This brief report examines differences in step- versus biological family support between White, Black, and Hispanic families in the United States. Background: The increasing share of stepfamilies reflects a potential shift in family relationships. Although research finds that stepfamilies are generally less likely to engage in instrumental support than biological families, recent work suggests that the relationship between family structure and family behaviors may vary across racial/ethnic groups. Method: Using data from the 2015-2017 Add Health Parent Study, this report examines racial/ethnic differences in step- versus biological family support between parents and adult children. Specifically, parents' likelihood of and hours of providing instrumental support to adult children are assessed. Results: Findings from this report indicate for Black and White families, stepfamilies are less likely to provide instrumental support to their adult children than biological families. Among Hispanic families, however, stepfamilies are not more or less likely to provide support than biological families. When hours of instrumental support are examined, White stepfamilies provide fewer hours of support than biological families, whereas no difference is found for Black or Hispanic families. Conclusion: Findings from this study contribute to broader work that calls for more nuanced understanding of the differential effects of family structure across social groups. Future research should consider applying within-race/ethnicity analyses when examining the association between family structure and intergenerational support.

Coconut milk allergenicity: Insight into reducing the affinity of coconut globulin to immunoglobulin E by atmospheric cold plasma.

Atmospheric cold plasma (ACP) presents a promising method for the sterilization of coconut milk and exhibits a modifying effect on coconut globulin (CG), the primary allergen in coconut milk. This study investigated the potential role of ACP treatment in mitigating the allergenic properties of coconut milk by examining changes in protein structure. ACP treatment induced structural alterations in CG, disrupting binding sites with immunoglobulin E (IgE). Consequently, this led to a reduction in the affinity between CG and IgE, evidenced by a decrease in Ka from 2.17 × 104/M to 0.64 × 104/M, thereby diminishing IgE-mediated allergic reactions. The findings from allergenic and cellular models further corroborated that ACP treatment decreased the allergenicity of CG by 55.18%, while inhibiting degranulation and the release of allergic mediators. This study presents an innovative methodology for producing hypoallergenic coconut milk, thereby expanding the applicability of ACP technology within the food industry.

The effectiveness of clinical thinking using a problem-solving model.

[Purpose] No established method for appropriately developing clinical thinking in physical therapy currently exists. This study examined whether clinical thinking can be appropriately developed using a problem-solving model. [Participants and Methods] Physical therapy students were asked to develop clinical thinking in the same two cases: one class using the problem-solving model and the other class using International Classification of Functioning, Disability and Health concepts. Each clinical thought was scored and compared based on consistency. [Results] In both cases, students who used the problem-solving model scored higher. [Conclusion] The hierarchical structure of the problem-solving model clarified the relationship between each element and this was easy to maintain, suggesting that it facilitated appropriate clinical thinking.

Experimental dataset on aluminium wedge slamming: Measurements of acceleration, pressure, strain, and video data.

This paper presents data from three experimental campaigns investigating slamming loads on a three-dimensional non-prismatic aluminium wedge, complementing the original research article "Slamming loads and responses on a non-prismatic stiffened aluminium wedge: Part I. Experimental study [1]." The experiments were designed to investigate the effects of slamming loads on structural responses through a series of free-fall drop tests. These tests included wedges with stiffened and unstiffened bottom plates to examine the influence of flexural rigidity on hydroelastic slamming. The experimental setup utilized three accelerometers for vertical acceleration measurement, sixteen pressure sensors for slamming pressure capture, and twenty strain gauges for recording structural responses. Detailed information on wedge geometry, material properties, and test plans is provided. Symmetric impact tests were conducted at drop heights from 25 cm to 200 cm with two different wedge masses. Asymmetric impact tests were carried out at three drop heights with heel angles ranging from 5 to 25°. The dataset includes time histories of sensor records, the geometry of the wedge section, and video footage from various runs. This comprehensive data offers insights into the effects of water impact velocity, deadrise angle, wedge mass, and bending stiffness on hydrodynamic pressures and structural responses on V-shaped sections. The experiments provide a valuable benchmark for future slamming impact research, aiding in the refinement of experiments, validation of numerical methods, and enhancement of mathematical models.

Scale Construction of "Breathing" Bi/N-CNSs Quasi-Array Structure with Hierarchical Bi Distribution for Sodium-Ion Battery.

Sodium ion batteries (SIBs) are promising postlithium battery technologies with high safety and low cost. However, their development is hampered by complicated electrode material preparation and unsatisfactory sodium storage performance. Here, a bismuth/N-doped carbon nanosheets (Bi/N-CNSs) composite featuring a quasi-array structure (alternated porous Bi layers and N-CNSs) with hierarchical Bi distribution (large particles of ∼35 nm in Bi layers and ultrafine Bi of ∼8 nm on N-CNSs) is prepared. Bi/N-CNSs delivers an ultralong-lifespan of 26000 cycles at 5 A g-1 and prominent rate capability of 91.5% capacity retention at 100 A g-1. Even at -40 °C, it exhibits a high rate capability of 161 mAh g-1 at 5 A g-1. Notably, the involved preparation method is characterized by a high yield of 14.53 g in a single laboratory batch, which can be further scaled up, and such a method can also be extended to synthesize other metallic-based materials.

Abiotic foldamer quaternary structures.

Abiotic aromatic foldamer sequences have been previously shown to fold in helix-turn-helix motifs in organic solvents. Using simple computational tools, a new helix-turn-helix motif was designed that bears additional hydrogen bond donor OH groups to promote its aggregation into a genuine, trimeric, abiotic quaternary structure. This sequence was synthesized and its self-assembly in solution was investigated by Nuclear Magnetic Resonance (NMR), Circular Dichroism (CD) and Molecular Dynamics (MD) simulations. The existence of two stable discrete aggregates was evidenced, one assigned to the initially designed trimer, the other to a dimer including multiple water molecules. The two species may be quantitatively interconverted upon changing the water content of the solution or the temperature. These results represent important steps in the design of protein-like abiotic architectures.

Building a Tailored Frame-Channel Structure for High-Performance Protein Air Filters.

To create a healthier indoor environment via sustainable technologies, there is a growing demand for constructing high-performance air filters from natural materials. Addressing this need, we have fabricated high-performance protein air filters with a tailored frame-channel structure via electrospinning. The innovative feature of the protein air filter is generated by adding a small amount of an organic salt, tetrabutylammonium chloride (TBAC), to modulate the denaturation of zein for tuning electrical charge distribution and hydrophilicity of the protein solutions. The results highlight that the optimized filter with 1.0 wt% TBAC exhibits a denser nanofiber assembly on the frame and a sparser arrangement on the channel. Functionally, the filter demonstrates ultralow pressure drop (ca. 9.04 Pa) that is only a third of that observed in unmodified formulation and commercial air filters, while it maintains high filtration efficiency in capturing PM2.5 (99.42% ± 0.30%) and PM0.3 (98.25 ± 0.39%). More importantly, the filter indicates multifunctional perspectives, e.g., high removal efficiency for formaldehyde (HCHO) and PM2.5 under high airflow rates (up to 8 L/min) or after prolonged testing period (120 min). Our design of the frame-channel structure for the protein air filter marks a leap forward in developing biomass-based structural materials.

Calculation method of temporary cable force in incremental launching construction of large span steel box girder without auxiliary pier.

The Fenshui River Bridge is a steel-concrete composite girder bridge with a main span of 90 m. Due to the topographical constraints, the steel box girder was constructed without the use of auxiliary piers, employing incremental launching techniques. This article focuses on the construction technology used for the steel box girder of the Fenshui River Bridge. Firstly, using the influence matrix method, the cable force is determined based on the maximum cantilever state of the structure, with the vertical deformation of the front end of the guide beam and the horizontal deformation of the top of the tower as the control objectives. The unstressed cable length is then calculated based on the mechanical relationship between cable deformation and cable force. A calculation method for adaptive cable force is proposed, which is based on the variation of the stress-free cable length within the adaptive structural system. Next, the finite element analysis method was employed to determine the optimal layout position for the tower. The results indicate that during the incremental launching construction of the steel box girder, the calculated cable forces using the method proposed in this paper are in close agreement with the measured cable forces. At the maximum cantilever state of the structure, the calculated and measured values of the cable force resulted in a percentage difference of 3.96%. The calculated values of deformation and stress in key sections showed a percentage difference of 6.4% for deformation and 6.6% for stress. To maximize the effectiveness of the tower and cable, the tower should be positioned above the bridge pier when the guide beam crosses the maximum span. The findings of this paper can serve as a reference for the construction of similar types of bridges.

Pore structure of the mixed sedimentary reservoir of Permian Fengcheng Formation in the Hashan area, Junggar Basin.

The Permian Fengcheng Formation (P1f.) in the Hashan area, situated on the southwestern margin of the Junggar Basin, has witnessed a remarkable breakthrough in shale oil exploration in recent years with nearly 789 million tons of shale oil resources. As a unique set of mixed sedimentary shales, the Fengcheng Formation in the Hashan area is characterized by mixed sedimentation of terrigenous siliciclastic sediments, authigenic minerals, and tuffaceous materials. However, the understanding of pore characteristics in the mixed sedimentary reservoir still remains limited, prohibiting accurate estimation of the oil content and insights into oil mobility. Scanning electron microscopy (SEM), X-ray diffraction (XRD), mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR), X-Ray Computer Tomography (X-CT), and geochemical analysis were performed to investigate the pore size distribution and main controlling factors of the mixed sedimentary reservoir. Results showed that the main pore types in the mixed sedimentary reservoir are intergranular pores and dissolution pores. The pores of the P1f. mixed shales in the Hashan area were classified into II-micropores (< 25 nm), I-micropores (25-100 nm), mesopores (100-1000 nm) and macropores (> 1000 nm). In general, the mixed sedimentary rocks of P1f. formation feature few macropores but a large number of micropores and mesopores. The CS exhibits the most favourable physical properties among all lithofacies. It is concluded that the abundance and maturity of organic matter, mineral composition, sedimentary structure, and diagenesis of reservoir together impact the pore structure in the mixed sedimentary reservoirs. The maturity of organic matter and the content of tuffaceous minerals are the most significant in influencing the pore structure of P1f. shales. Overall, the pore structure of complex lithologic reservoir formed by mixed deposition and its influence on physical properties are studied, and the characteristics of the microscopic pore-throat system of the dominant lithofacies in the Hashan area are clarified, which is of great significance as a guide for the exploration and development of mixed sedimentary reservoirs in continental shale oil in China.

Improved simultaneous mapping of epigenetic features and 3D chromatin structure via ViCAR.

Methods to measure chromatin contacts at genomic regions bound by histone modifications or proteins are important tools to investigate chromatin organization. However, such methods do not capture the possible involvement of other epigenomic features such as G-quadruplex DNA secondary structures (G4s). To bridge this gap, we introduce ViCAR (viewpoint HiCAR), for the direct antibody-based capture of chromatin interactions at folded G4s. Through ViCAR, we showcase the first G4-3D interaction landscape. Using histone marks, we also demonstrate how ViCAR improves on earlier approaches yielding increased signal-to-noise. ViCAR is a practical and powerful tool to explore epigenetic marks and 3D genome interactomes.

Brain-consistent architecture for imagination.

Background: Imagination represents a pivotal capability of human intelligence. To develop human-like artificial intelligence, uncovering the computational architecture pertinent to imaginative capabilities through reverse engineering the brain's computational functions is essential. The existing Structure-Constrained Interface Decomposition (SCID) method, leverages the anatomical structure of the brain to extract computational architecture. However, its efficacy is limited to narrow brain regions, making it unsuitable for realizing the function of imagination, which involves diverse brain areas such as the neocortex, basal ganglia, thalamus, and hippocampus. Objective: In this study, we proposed the Function-Oriented SCID method, an advancement over the existing SCID method, comprising four steps designed for reverse engineering broader brain areas. This method was applied to the brain's imaginative capabilities to design a hypothetical computational architecture. The implementation began with defining the human imaginative ability that we aspire to simulate. Subsequently, six critical requirements necessary for actualizing the defined imagination were identified. Constraints were established considering the unique representational capacity and the singularity of the neocortex's modes, a distributed memory structure responsible for executing imaginative functions. In line with these constraints, we developed five distinct functions to fulfill the requirements. We allocated specific components for each function, followed by an architectural proposal aligning each component with a corresponding brain organ. Results: In the proposed architecture, the distributed memory component, associated with the neocortex, realizes the representation and execution function; the imaginary zone maker component, associated with the claustrum, accomplishes the dynamic-zone partitioning function; the routing conductor component, linked with the complex of thalamus and basal ganglia, performs the manipulation function; the mode memory component, related to the specific agranular neocortical area executes the mode maintenance function; and the recorder component, affiliated with the hippocampal formation, handles the history management function. Thus, we have provided a fundamental cognitive architecture of the brain that comprehensively covers the brain's imaginative capacities.

Crystal structure of Kunitz-type trypsin inhibitor: Entomotoxic effect of native and encapsulated protein targeting gut trypsin of Tribolium castaneum Herbst.

Trypsin inhibitors are known to act against insect pests by inhibiting proteases of the digestive tract. In this study, we report structural and functional characterization of ∼ 19 kDa Albizia procera Kunitz-type trypsin inhibitor (ApKTI) protein with potential bio-insecticidal applications. Crystal structure of ApKTI protein has been refined to 1.42 Å and molecular structure (8HNR) showed highly beta sheeted conformation including 12 beta sheets, 15 loops and two small alpha helices. Docking between predicted model of Tribolium castaneum trypsin (TcPT) and 8HNR produced a stable complex (-11.3 kcal/mol) which reflects the inhibitory potential of ApKTI against insect gut trypsin. Significant mortality was observed in all life stages of T. castaneum including egg, larvae, pupae and adults with a 3.0 mg native ApKTI treatment in comparison to negative control. Although standard trypsin inhibitor (Glycine max trypsin inhibitors; GmKTI; 3.0 mg) produced maximum reduction against all above life stages; however, a non-significant mortality difference was observed in comparison to 3.0 mg native ApKTI. The study further explores the synthesis and characterization of Graphene (GNPs) and Zinc oxide (ZnONPs) nanoparticles, followed by the optimization of ApKTI and GmKTI loading on both nanoparticles to evaluate their enhanced insecticidal effectiveness. Encapsulated proteins showed significant mortality against T. castaneum across all concentrations, with GNPs proving more effective than ZnONPs. Additionally, encapsulated GmKTI produced significant mortality of eggs compared to loaded ApKTI treatments while other life stages were non-significantly affected by two proteins. This research highlights the importance of encapsulated ApKTI protein for eco-friendly pest management strategies.

Comprehensive insights of pretreatment strategies on the structures and bioactivities variation of lignin-carbohydrate complexes.

Introduction: Due to its unique structural features and bioactivities, the lignin-carbohydrate complex (LCC) displays great potential in vast industrial applications. However, the elucidation of how various pretreatment methods affect the structure and bioactivities remains unaddressed. Method: The three pretreatment methods were systematically studied on the variations of structures and bioactivities, and the Gramineae plant, i.e., wheat straw, was adopted in this study. The structures and bioactivities variation caused by different pretreatments were studied in detail. Result and Discussion: The results showed that compared to physical or chemical pretreatments, biological pretreatment was the most effective approach in improving the bioactivities of LCC. The LCC from biological pretreatment (enzymatic hydrolysis, ELCC4) had more functional groups while the lower weight-average molecular weight (Mw) and polydispersity index (PDI) were well-endowed. The highest antioxidant abilities against ABTS and DPPH of ELCC4 were high up to 95% and 84%, respectively. Furthermore, ELCC4 also showed the best ultraviolet (UV)-blocking rate of 96%, which was increased by 6% and 2% compared to LCC8 (physical pretreatment) and LLCC4 (chemical pretreatment). This work prospectively boosts the understanding of pretreatment strategies on the structures and bioactivities variation of LCC and facilitates its utilization as sustainable and biologically active materials in various fields.

Some biological aspects of chacunda gizzard shad, Anodontostoma chacunda (Hamilton, 1822) from the Bay of Bengal, Bangladesh.

Anodontostoma chacunda is a commercial fish species in the market and is usually consumed in fresh, smoked, and dried forms. This study investigated the population structure, length-weight relationships (LWR), condition factor (K F ), size at sexual maturity (L m ), and breeding season of A. chacunda in the Bay of Bengal, Bangladesh, using the data collected from January to December 2020. A total of 1061 individuals were collected in the sampling period with the help of fishers. Total length (TL) and body weight (BW) were measured using a measuring board and an electronic balance. The TL ranged from 12.50 to 26.70 cm. The allometric coefficient (b) value was 3.34, indicating positive allometric growth in this species. The fish is in good condition, evidenced by its condition factor (K F ) ranging between 0.88 and 1.73. Maturity size ranged from 15.40 to 16.80 cm (TL) based on three distinguished models. Spawning time lasts from January to May and from September to December. The peak spawning time was December of A. chacunda in the Bay of Bengal. This information could prove valuable for fisheries researchers and biologists, facilitating efforts toward the conservation and sustainable management of this species.

Medicinal potential of embelin and its nanoformulations: An update on the molecular mechanism and various applications.

Natural herbs have garnered significant research recently as their components target multiple disease signaling pathways, making them highly potential for various disease prevention and treatment. Embelin, a naturally occurring benzoquinone isolated from Embelia ribes, has shown promising biological activities such as antitumor, antidiabetic, anti-oxidant, and antimicrobial. Various mechanisms have been reported, including monitoring genes that synchronize the cell cycle, up-regulating multiple anti-oxidant enzymes, suppressing genes that prevent cell death, influencing transcription factors, and preventing inflammatory biomarkers. However, the hydrophobic nature of embelin leads to poor absorption and limits its therapeutic potential. This review highlights a wide range of nanocarriers used as delivery systems for embelin, including polymeric nanoparticles, liposomes, nanostructured lipid carriers, micelles, nanoemulsion, and metallic nanoparticles. These embelin nanomedicine formulations have been developed in preclinical studies as a possible treatment for many disorders and characterized using various in vitro, ex vivo, and in vivo models.

Complete Mapping of Thermodynamic Stability of Ternary Oxide SrTiO3 (001) Surface at Finite Temperatures.

The oxide surface structure plays a vital role in controlling and utilizing the emergent phenomena occurring at the interface of nanoarchitecture. A complete understanding of ternary oxide surfaces remains challenging due to complex surface reconstructions in various chemical and physical environments. Here a thermodynamic framework is developed to treat the stability of ternary oxide surfaces with finite temperature and chemical environments. Strontium titanate, as a representative ternary oxide, is used to establish the complete energy landscape of SrTiO3 (001) surface. The complete mapping yields a comprehensive understanding of various stable SrTiO3 surfaces with finite temperature and chemical potential or vapor pressure of the constituents, i.e., Sr (or Ti) metal and oxygen. This treatment also reveals a stable surface unknown yet with SrTi2O3 stoichiometry, which unveils the missing link between numerous previous experimental observations and the current understanding of SrTiO3 surface. Interestingly, the new surface shows an anisotropic surface-localized metallic state originating from the characteristic surface structure. The findings would provide a viable way to understand ternary oxide surfaces and further utilize SrTiO3 surfaces for oxide nanoarchitectures.

Synthesis and characterization of modified chitosan as a promising material for enterosorption of heavy metal ions.

Currently, an important ecological problem is environmental pollution and its negative impact on living organisms, the consequences of which are deterioration in general health and the manifestation of various diseases, poisoning, endo- and exotoxicosis. Enterosorption method was proposed as a promising method for removing toxic substances from the living organisms using enterosorbents which can absorb various toxic substances of endogenous and exogenous nature in the lumen of the gastrointestinal tract. It has been proposed to use polymer-containing enterosorbents for eliminating of heavy metals from the organism. The purpose of this research was to synthesize a quaternized derivative of chitosan, specifically N-(2-hydroxybenzyl)-N-ethyl-N-methyl chitosan chloride (Q-CHS). The synthesis of Q-CHS involved the formation of a Schiff base, followed by the quaternization of the amino group of chitosan (CHS). The structures of both pure CHS and quaternized CHS were studied using various physico-chemical methods, including FTIR, NMR, XRD, SEM, DSC and TGA analyses in order to determine the structure and confirm the formation of the final product.