Structure Analysis Research Articles

Synthesis of Efficient S-Scheme Heterostructures Composed of BiPO4 and KNbO3 for Photocatalytic N2 Fixation and Water Purification.

The preparation of catalysts with heterojunction structures is a strategy to achieve efficient charge separation and high photocatalytic activity of photocatalysts. In this work, BiPO4/KNbO3 heterostructure photocatalysts were fabricated by a combination of hydrothermal and precipitation methods and subsequently employed in catalyzing N2-to-NH3 conversion and RhB degradation under light illumination. Morphological analysis revealed the effective dispersion of BiPO4 on KNbO3 nanocubes. Band structure analysis suggests that KNbO3 and BiPO4 exhibit suitable band potentials to form an S-scheme heterojunction. Under the joint action of the built-in electric field at the interface, energy band bending, and Coulomb attraction force, photogenerated electrons and holes with low redox performance are consumed, while those with high redox performance are effectively spatially separated. Consequently, the BiPO4/KNbO3 shows enhanced photocatalytic activity. The NH3 production rate of the optimal sample is 2.6 and 5.8 times higher than that of KNbO3 and BiPO4, respectively. The enhanced photoactivity of BiPO4/KNbO3 is also observed in the photocatalytic degradation of RhB. This study offers valuable insights for the design and preparation of S-scheme heterojunction photocatalysts.

Unravelling genetic diversity and population structure of Sarocladium oryzae causing sheath rot disease in rice using hyper-variable SSR markers

Rice sheath rot, caused by the fungus Sarocladium oryzae, poses a major threat to rice crops. This pathogen exhibits substantial variability in the field, yet limited information on its genetic diversity and population structure hampers the development of effective disease management strategies. In this study, hyper-variable Simple Sequence Repeats (HV-SSR) markers were employed for the first time to assess the genetic diversity of Sarocladium oryzae, collected from various rice cultivating regions in Odisha, Eastern India. The isolates were identified using both morphological and molecular criteria. A pathogenicity test was performed for all the isolates. A total of 2558 HV-SSRs with more than 10 repeat units were identified in the genome of S. oryzae. The most prevalent types of repeats were dinucleotides (26.8%), followed by trinucleotides (22.8%), tetranucleotides (8.67%), pentanucleotides (2.83%), and hexanucleotides (1.83%). A total of 150 HV-SSR primers were designed and 24 were randomly selected and validated, of which ten of them demonstrating polymorphism in the 87 isolates. These ten polymorphic hyper-variable SSR markers were subsequently used to assess the genetic diversity and population structure of Sarocladium oryzae isolates. The markers revealed a total of 32 alleles, with the number of alleles per locus varying from 2 to 4. Gene diversity ranged from 0.409 to 0.641, while the major allele frequency varied from 0.448 to 0.736. The Polymorphic Information Content (PIC) values ranged from 0.325 to 0.569, with an average of 0.457. Cluster analysis categorized the sheath rot isolates into three distinct major clusters. Principal coordinate analysis and structure analysis identified two genetic clusters within S. oryzae isolates. Analysis of molecular variance indicated that there was more genetic variation within populations (55%) and less variation among populations (45%). The findings of this study provide insights into the genetic diversity of S. oryzae in the rice-cultivating regions of Odisha, which can be used to develop more effective disease management strategies.

DbGTi: Thermostable trypsin inhibitor from Dioscorea bulbifera L. ground tubers: assessment of antioxidant and antibacterial properties and cytotoxicity evaluation using zebrafish model

Oxidative stress disorders and diseases caused by drug-resistant bacteria have emerged as significant public health concerns. Plant-based medications like protease inhibitors are growing despite adverse effects therapies. Consecutively, in this study, trypsin inhibitors from Dioscorea bulbifera L. (DbGTi trypsin inhibitor) ground tubers were isolated, purified, characterized, and evaluated for their potential cytotoxicity, antibacterial, and antioxidant activities. DbGTi protein was purified by Q-Sepharose matrix, followed by trypsin inhibitory activity. The molecular weight of the DbGTi protein was found to be approximately 31 kDa by SDS-PAGE electrophoresis. The secondary structure analysis by circular dichroism (CD) spectroscopy revealed that the DbGTi protein predominantly comprises β sheets followed by α helix. DbGTi protein showed competitive type of inhibition with Vmax = 2.1372 × 10−1 μM/min, Km = 1.1805 × 102 μM, &Ki = 8.4 × 10−9 M and was stable up to 70 °C. DbGTi protein exhibited 58 % similarity with Dioscorin protein isolated from Dioscorea alata L. as revealed by LC-MS/MS analysis. DbGTi protein showed a non-toxic effect, analyzed by MTT, Haemolytic assay and in vivo studies on zebrafish model. DbGTi protein significantly inhibited K. pneumoniae and has excellent antioxidant properties, confirmed by various antioxidant assays. The results of anti-microbial, cytotoxicity and antioxidant assays demonstrate its bioactive potential and non-toxic nature.

Синтаксические средства экспрессивности (на материале заголовков удмуртских публицистических текстов)

The study aims to describe the features of the structural-semantic organization of the titles of journalistic texts in Udmurt within the framework of expressive syntax. The scientific novelty lies in identifying the expressive-evaluative potential of the title as a structural element of mass media texts; in determining syntactic redundancy and syntactic insufficiency in the lexico-grammatical structures of the Udmurt language. The results suggest that syntactic heterogeneity is peculiar to the titles of journalistic texts in Udmurt. Based on the analysis of the title structure of the “Udmurt dunne” newspaper for 2020-2023, it was found that the authors of the articles prefer such stylistic devices as inversion, elliptical sentences, rhetorical exclamations, which are primarily used to express the emotive, attractive and appellative functions. Various kinds of repetitions, gradation, parcelling and polysyndeton are characterized by low frequency, accounted for by the internal specifics of the newspaper title, which tends to brevity of expression. The use of various means and devices in the titles of journalistic texts makes it possible to perform the influencing, expressive, attractive, appellative, narrative functions of a newspaper text.

COMPARATIVE ANALYSIS OF THE CAPABILITIES OF SPECTRAL METHODS IN STUDYING INTERNAL ROTATION OF COMPOUNDS OF THE BENZOIC SERIES

t. In the review the comparison of the methods used to study internal rotation (IR) in the ground (S0) and excited (S1) electronic states for compounds of the benzoic series C6H5–COR, where R = H, F, CI. In (S0) electronic state differences in the values of (0-v) transitions of torsional vibration for studied compounds are revealed in the methods of analysis of the vibrational structure of n-π* transition of high-resolution UV absorption spectra and IR-Fourier-spectra. The reasons for such differences are established. In the excited (S1) state for benzaldehyde a comparison was made between the method of analyzing the vibrational structure of n-π* transition of high-resolution UV absorption spectra and the method of analyzing the excitation spectra of sensitized phosphorescence of this compound in a cooled jet. It is concluded that the method of analyzing the vibrational structure of n-π* transition of high-resolution UV absorption spectra of vapors of the investigated compounds is more reliable and accurate when studying (IR) in both electronic states.

Sound Quality Analysis and Optimization of Loudspeakers Based on Electromagnetic Principle

The sensory feeling brought by the speaker’s sound quality determines the speaker’s quality, and whether a better speaker can be designed depends on whether the factors affecting the speaker’s sound quality can be correctly analyzed. Through the analysis of the loudspeaker structure and the application of physics in the loudspeaker, the factors affecting the sound quality of the loudspeaker are analyzed from the two aspects of the magnetic circuit system and the vibration system, which is intended to help designers analyze and understand the physical characteristics of the loudspeaker, to make better audio equipment.

Analysis of the capital structure of the pharmaceutical industry —— Take Hengrui Pharmaceutical as an example

Capital structure results from the enterprise’s financing mix in a certain period, reflecting the value composition and proportionality of the enterprise’s various types of capital. As an important indicator for judging the financial status of an enterprise, capital structure reflects, to a large extent, the enterprise’s ability to repay debt and refinance. Reasonable capital structure can effectively play the regulatory role of financial leverage, reduce enterprises’ financing costs, and improve their profitability. Whether the capital structure is reasonable affects the future development of the enterprise. Therefore, the management of the company should adjust the capital structure according to the actual situation of the enterprise and the market situation, and how to achieve the optimal capital structure is a problem worth discussing. This paper takes Hengrui Pharmaceutical as an example and analyzes the capital structure of the pharmaceutical industry. The in-depth study of the historical data and financial report of Hengrui Pharmaceutical reveals the capital structure and influencing factors of Hengrui Pharmaceutical, as well as how these factors affect the company’s financial performance. By analyzing the capital structure of Hengrui Pharmaceutical, we can understand the company’s debt level, debt ratio, asset structure, and capital source.

Optimization of Perovskite/Colloidal Quantum Dot Monolithic Tandem Solar Cell to Enhance Device Performance via Solar Cell Capacitance Simulator 1D

Tandem solar cells (TSCs) based on metal halide perovskites offer a route to increase power conversion efficiency (PCE). However, there are limited options for narrow‐bandgap bottom subcells. Colloidal quantum dots‐based solar cells are found attractive for this role. Herein, a cost‐effective two‐terminal (2T) monolithic TSC structure consisting of wide‐bandgap all‐inorganic perovskite top subcell and narrow‐bandgap chalcogenide PbS quantum dots bottom subcell is proposed. For optimization of the PCE of the tandem structure, standalone and tandem analysis are done in terms of variation of absorber layer thickness, total defect density, interfacial defect density, back metal contact, current density voltage (J–V) curves, external quantum efficiency, current matching, and tandem photovoltaic parameters. Optimized TSCs designed with the 530 nm/450 nm‐thick absorber layers of top/bottom sub cells result in of 19.28 mA cm−2, of 1.89 V, and PCE of 27.32%. It is found that performance of the device is very sensitive to the total defect density of the bottom subcell. Therefore, high PCE can be obtained by controlling the total defect density of the bottom subcell. This work motivates the experimental realization of low‐cost, high‐efficiency TSCs for further research.

Long indium-rich InGaAs nanowires by SAG-HVPE

We demonstrate the selective area growth of InGaAs nanowires (NWs) on GaAs (111)B substrates using hydride vapor phase epitaxy (HVPE). A high growth rate of more than 50 μm h−1 and high aspect ratio NWs were obtained. Composition along the NWs was investigated by energy dispersive x-ray spectroscopy giving an average indium composition of 84%. This is consistent with the composition of 78% estimated from the photoluminescence spectrum of the NWs. Crystal structure analysis of the NWs by transmission electron microscopy indicated random stacking faults related to zinc-blende/wurtzite polytypism. This work demonstrates the ability of HVPE for growing high aspect ratio InGaAs NW arrays.

Comprehensive Analysis of the GRAS Gene Family in Paulownia fortunei and the Response of DELLA Proteins to Paulownia Witches' Broom.

The GRAS (GAI\RGA\SCL) gene family encodes plant-specific transcription factors that play crucial roles in plant growth and development, stress tolerance, and hormone network regulation. Plant dwarfing symptom is mainly regulated by DELLA proteins of the GRAS gene subfamily. In this study, the association between the GRAS gene family and Paulownia witches' broom (PaWB) was investigated. A total of 79 PfGRAS genes were identified using bioinformatics methods and categorized into 11 groups based on amino acid sequences. Tandem duplication and fragment duplication were found to be the main modes of amplification of the PfGRAS gene family. Gene structure analysis showed that more than 72.1% of the PfGRASs had no introns. The genes PfGRAS12/18/58 also contained unique DELLA structural domains; only PfGRAS12, which showed significant response to PaWB phytoplasma infection in stems, showed significant tissue specificity and responded to gibberellin (GA3) in PaWB-infected plants. We found that the internodes were significantly elongated under 100 µmol·L-1 GA3 treatment for 30 days. The subcellular localization analysis indicated that PfGRAS12 is located in the nucleus and cell membrane. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays confirmed that PfGRAS12 interacted with PfJAZ3 in the nucleus. Our results will lay a foundation for further research on the functions of the PfGRAS gene family and for genetic improvement and breeding of PaWB-resistant trees.

Revealing the role of high-valence elementary substitution in the hydrogen-induced Mottronic transitions of vanadium dioxide

Electron-doping Mottronics within correlated vanadium dioxide (e.g., VO2) opens up a paradigm to abruptly regulate the Mottronic phase transitions via adjusting the d-orbital occupancy and configuration. Nevertheless, the potential impact of high-valence elementary substitution in the hydrogen-associated Mottronic transitions of VO2 is yet unclear. Herein, we demonstrate the role of high-valence elementary substitution (e.g., W6+) in regulating the hydrogen-triggered Mottronic transitions of VO2, assisted by quantitative hydrogen analysis using the nuclear reaction analysis. Substituting vanadium with a high-valence transitional metal (e.g., W6+) within doped-VO2 largely reduces the hydrogen incorporation (e.g., ∼1.61 × 1021 cm−3 in H0.06V0.95W0.05O2) compared to the intrinsic VO2 (e.g., ∼1.08 × 1022 cm−3 in H0.35VO2) under the low temperature hydrogenation process. Therefore, in contrast to hydrogen-induced electron localization of intrinsic VO2 upon low-temperature hydrogenation, only the hydrogen-triggered metallic state is observed within the hydrogen-associated phase diagram of WxV1-xO2, as further probed by the near-edge x-ray absorption fine structure analysis and x-ray photoelectron spectroscopy. The present work reveals the overlooked role associated with the donor substitutions that largely influences the competitive equilibrium between the two rival hydrogen-induced Mottronic transitions within VO2 toward either the metallic or the highly insulating phase.

Genome-wide identification, expression and function analysis of the MTP gene family in tulip (Tulipa gesneriana).

Currently, soil heavy metal contamination is a severe issue, particularly with Cd pollution. The metal tolerance protein (MTP) proteins, as plant divalent cation transporters, play a crucial role in the transport and tolerance of heavy metals in plants. This study conducted comprehensive identification and characterization of the MTP gene family in the tulip. A total of 11 TgMTP genes were identified and phylogenetically classified into three subfamilies. Conserved motif and gene structure analyses unveiled commonalities and variations among subfamily members. Expression profiling demonstrated several TgMTPs were markedly upregulated under Cd exposure, including the TgMTP7.1. Heterologous expression in yeast validated that TgMTP7.1 could ameliorate Cd sensitivity and enhance its tolerance. These results provide primary insights into the MTP gene family in tulip. Phylogenetic relationships and functional analyses establish a framework for elucidating the transporters and molecular mechanisms governing Cd accumulation and distribution in tulip. Key TgMTPs identified, exemplified by TgMTP7.1, may illuminate molecular breeding efforts aimed at developing Cd-tolerant cultivars for the remediation of soil Cd contamination.

An Algorithm Based on Non-Negative Matrix Factorization for Detecting Communities in Networks

Community structure is a significant characteristic of complex networks, and community detection has valuable applications in network structure analysis. Non-negative matrix factorization (NMF) is a key set of algorithms used to solve the community detection issue. Nevertheless, the localization of feature vectors in the adjacency matrix, which represents the characteristics of complex network structures, frequently leads to the failure of NMF-based approaches when the data matrix has a low density. This paper presents a novel algorithm for detecting sparse network communities using non-negative matrix factorization (NMF). The algorithm utilizes local feature vectors to represent the original network topological features and learns regularization matrices. The resulting feature matrices effectively reveal the global structure of the data matrix, demonstrating enhanced feature expression capabilities. The regularized data matrix resolves the issue of localized feature vectors caused by sparsity or noise, in contrast to the adjacency matrix. The approach has superior accuracy in detecting community structures compared to standard NMF-based community detection algorithms, as evidenced by experimental findings on both simulated and real-world networks.

Cryogen-free 400-MHz nuclear magnetic resonance spectrometer as a versatile tool for pharmaceutical process analytical technology.

The discovery of new ceramic materials containing Ba-La-Cu oxides in 1986 that exhibited superconducting properties at high temperatures in the range of 35 K or higher, recognized with the Nobel Prize in Physics in 1987, opened a new world of opportunities for nuclear magnetic resonance (NMRs) and magnetic resonance imaging (MRIs) to move away from liquid cryogens. This discovery expands the application of high temperature superconducting (HTS) materials to fields beyond the chemical and medical industries, including electrical power grids, energy, and aerospace. The prototype 400-MHz cryofree HTS NMR spectrometer installed at Amgen's chemistry laboratory has been vital for a variety of applications such as structure analysis, reaction monitoring, and CASE-3D studies with RDCs. The spectrometer has been integrated with Amgen's chemistry and analytical workflows, providing pipeline project support in tandem with other Kinetic Analysis Platform technologies. The 400-MHz cryofree HTS NMR spectrometer, as the name implies, does not require liquid cryogens refills and has smaller footprint that facilitates installation into a chemistry laboratory fume hood, sharing the hood with a process chemistry reactor. Our evaluation of its performance for structural analysis with CASE-3D protocol and for reaction monitoring of Amgen's pipeline chemistry was successful. We envision that the HTS magnets would become part of the standard NMR and MRI spectrometers in the future. We believe that while the technology is being developed, there is room for all magnet options, including HTS, low temperature superconducting (LTS) magnets, and low field benchtop NMRs with permanent magnets, where utilization will be dependent on application type and costs.

Genome-Wide Identification and Expression Analysis of SWEET Gene Family in Strawberry

The Sugars Will Eventually be Exported Transporter (SWEET) is a class of bidirectional sugar transporter that is involved in critical physiological processes such as plant growth and development, and its response to biotic and abiotic stresses. Currently, there are few reports on the SWEET gene family in strawberry. In this study, we mined the SWEET gene family members in Fragaria × ananassa ‘Camarosa’ and carefully analyzed their molecular features and expression patterns. The results showed that 77 FanSWEET genes existed in the F. × ananassa ‘Camarosa’ genome, and the phylogenetic analysis classified them into four sub-groups. Analysis of gene structure, conserved structural domains, and conserved motifs showed that FanSWEETs were highly conserved during the evolutionary process. Expression profiling of the 11 FanSWEET genes revealed that three members were highly expressed in strawberry fruits, which were presumed to be involved in sugar transport during strawberry fruit ripening. In addition, based on the exogenous sugar-spraying treatment and quantitative real-time PCR analysis, we found that different members responded to different sugar treatments in different response patterns, and their functions in sugar transport need to be further explored. The present study provides a reference for further analysis of the functions of the SWEET gene in strawberry.

Revealing Urban Color Patterns via Drone Aerial Photography—A Case Study in Urban Hangzhou, China

Urban color, primarily emanating from building façades and roofs, plays a pivotal role in shaping a city’s image and influencing people’s overall impression. Understanding the nuances of color patterns contributes significantly to unraveling the uniqueness and identity of a city. This study introduces a statistical method for the systematic analysis of urban color and macroscopic urban structure. Specifically, we employ drones to collect and extract building roof and façade colors in the main urban area of Hangzhou, mapping these colors to the HSV color space. Subsequently, we establish a random walk model and an origin–destination trip model within the urban transportation network to simulate the movement of people. Our experiments reveal robust correlations between façade and roof values and passing frequency (with the Pearson correlations reaching 0.70). Through a rigorous statistical analysis, we gain insights into the distribution of urban color and the impact of architectural structures on color variations, identifying potential patterns or trends. By integrating color data with architectural structure data, our systematic research method deepens the understanding of the visual features that define cities. Beyond theoretical exploration, this approach offers practical insights for building planning and design. This study not only sheds light on the relationship between architectural structures and urban color but also provides valuable guidance for future urban development initiatives.

Insight into the Grain Refining Mechanism of Al–Ti–C and the Interfacial Properties between the Inoculants and Aluminum

The grain refinement mechanism of Al–Ti–C grain refiners used in the casting procedure of aluminum has been studied by first‐principles calculation. Considering the controversy over Al3Ti, TiC, or Al3Ti–TiC as nucleation sites, the adsorption behavior of possible nucleation surfaces for Al atoms, including adsorption energies and adsorption sites, as well as the interfacial properties of Al/Al3Ti/TiC are calculated and compared. In the results, it is shown that the Al3Ti(112) surface has a stronger adsorption capacity for Al than TiC. By using the edge‐to‐edge matching crystallographic model and the calculation of the adsorption energy, it is found that the monolayer Al3Ti(112) can be stabilized on the TiC(100) surface, and the combination of TiC and monolayer Al3Ti can significantly improve the adsorption capacity of Al. Interfacial electronic structure analysis shows stronger chemical bonding between Al and Ti at the Al/Al3Ti/TiC interface compared to Al/Al3Ti, which explains that the monolayer Al3Ti covering the TiC surface has the strongest adsorption capacity for Al atoms. Therefore, it is speculated that TiC with a monolayer of Al3Ti covering the surface will serve as a potential nucleation site during grain refinement, which will provide a theoretical reference for future research work.

Unveiling the mutual effects of hydroxyl and dibenzhydryl groups in α‐diimino‐nickel precatalysts for direct synthesis of polyethylene elastomers

The properties and practical applications of polyethylene are closely associated with the polymer molecular weight, polydispersity, degree of branching, and the type of branches and its arrangement within microstructure. In this study, a set of structurally diverse unsymmetrical 1‐(2,6‐dibenzhydryl‐4‐hydroxylphenylimino)‐2‐(2,6‐(R)‐4‐(R1)phenylimino)acenaphthene‐nickel dibromide precatalysts (where Ni2Me [R = Me, R1 = H], Ni2Et [R = Et, R1 = H], Ni2iPr [R = iPr, R1 = H], Ni3Me [R, R1 = Me], Ni2Et,Me [R = Et, R1 = Me]) has been prepared and studied for ethylene polymerization. Molecular structure analysis of Ni2Me and Ni2Et complexes revealed distorted tetrahedral geometries at nickel. The polymerization activities are extremely high for all precatalysts upon activation with either EASC or MMAO aluminum reagents, a trend notably pronounced in the case of the EASC‐activated systems, entering activity in the range of 10 million g mol−1 h−1 at 30°C. The Ni2Me demonstrated exceptional performance at higher temperatures, achieving an activity of 2.4 × 106 g mol−1 h−1 at 100°C and generated high molecular weight polyethylene (Mw = 105 g mol−1) with narrow polymer dispersity across all reaction temperatures (Ð ≈ 1.5). High temperature 13C NMR spectra identified 97–142/1000C branches in resulting polyethylene, a feature significantly dependent on the reaction temperature. In terms of mechanical properties, stress–strain analysis indicated that polyethylene synthesized at lower temperatures displayed superior tensile strength compared with that produced at higher reaction temperatures, while a reverse trend was observed in strain recovery analysis. The high strain recovery (up to 72%) of these polyethylene highlights the characteristic properties of thermoplastic elastomers.

Aerobic benzyl alcohol oxidation by copper(I)(2,2′-bipyridine)-based catalysts

“In situ” prepared cationic Cu(I) complexes bearing 2,2’-bipyridine ligands and trifluoromethylsulfonate (triflate) have been used to catalyze the aerobic oxidation of benzyl alcohol to benzaldehyde in acetonitrile in the presence of (2,2,6,6-tetramethylpiperidin-1-yl) oxyl (TEMPO). A combination of catalytic reactions, operando1H NMR spectroscopic studies and the analysis of the molecular structure of the Cu(I) precatalysts in acetonitrile by means of DFT calculations shed light on the notable influence of counter-anion ligand interactions on the observed catalytic activity.

Internal structure and invariance analysis of the EAGrit-LP-R scale for Grit assessment

Grit is a stable and measurable trait. It refers to the individual’s ability to maintain efforts and interest in projects that take time to complete and are useful in educational contexts. In this study we investigated the validity of a short version of the Grit |International Assessment Scale, Portuguese Version (EAGrit-LP) based on the internal structure and invariance. A total of 1402 students from Brazil (53.2%) and Portugal (46.8%) participated in the survey. The students answered online the EAGrit-LP and the sociodemographic questionnaire. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were used to reduce the EAGrit-LP from 12 to 8 items, with two factors explaining 55.7% variance and replicating the theoretical structure, with excellent fit indices. Invariance analysis showed no differences in the responses of male and female participants. The results demonstrate that the short version of the instrument presents evidence of internal structure validity and invariance in connection with genders.