Analysis Of Fine Structure Research Articles

Enhanced decoupling of conductivity relaxation from structural relaxation in non-stoichiometric protic ionic liquids involving triflic acid and 2-aminoethyl hydrogen sulfate.

The glass transition dynamics and conductivity relaxation are studied for a series of non-stoichiometric protic ionic liquids (PILs) based on 2-aminoethyl hydrogen sulfate and triflic acid with varying molar ratios (denoted as AT-55, AT-46, AT-37, AT-28, and AT-19) by broadband dielectric spectroscopy in a wide frequency (10-1-107Hz) and temperature range (173-353K). The results indicate that the addition of acid lowers the glass transition temperature, as confirmed by the activation energy fine structure analysis and a crossover in the conductivity relaxation time. Notably, samples with higher acid content deliver markedly increased conductivity. In addition, detailed analysis of the permittivity and modulus spectra reveals enhanced decoupling between the structural (α-process) and conductivity relaxation in samples with a higher acid content. Remarkably, nano-phase separation in AT-28 and AT-19 samples is observed, resulting in a second glass transition temperature indicating a more mobile phase. Based on the above-mentioned findings, we infer that increased acid content disrupts strong ionic interactions within the IL fraction, resulting in a decrease in the glass transition temperature and leading to nano-phase separation into distinct acid-rich and IL-rich phases with varying Tg values. This phase separation alters the long-range ionic pathways, shifting from being solely governed by IL cluster dynamics to a scenario where charge transport becomes largely decoupled from the dynamics of IL-rich clusters. Hence, modulating the stoichiometry of PILs appears a promising approach to enhance the conductivity together with widening the usable temperature range for applications.

Investigation of short-term chemical changes in stable ruthenium added to soil by using X-ray absorption fine-structure analysis.

Radioactive ruthenium may be accidentally released from spent nuclear fuel reprocessing plants to the surrounding environment. However, research on the chemical behavior of radioactive Ru in the environment is limited, and the complex chemical properties of this element complicate the application of extraction methods for the analyses of its chemical forms. To obtain basic information regarding the outcome of radioactive Ru in the environment, we investigated the changes in the form of stable Ru added to soil through X-ray absorption fine-structure (XAFS) analysis. This study uses ruthenium tetroxide (RuO4), ruthenium dioxide (RuO2), ruthenium nitrosyl nitrate (Ru(NO)(NO3)3) and ruthenium chloride (RuCl3) as test sources. These are added to ultrapure water, soil solution or fresh soil samples, which are analyzed using XAFS immediately or 5 days after Ru addition. The Ru K-edge X-ray absorption near edge structure spectra acquired immediately after Ru addition differed with respect to the source. The XAFS results suggest that RuO4 immediately changes to tetravalent form after deposition from air to soil. For RuCl3, the ionic structure in the vicinity of Ru is affected by the soil even if the valence does not change immediately. By contrast, RuO2 and Ru(NO)(NO3)3 are highly stable in soil. The results show that the chemical forms of RuO2 and Ru(NO)(NO3)3 added to the soil solution and soil are retained for 5 days, whereas those of RuCl3 and RuO4 are affected by the soil solution and soil within a short period. These results emphasize the need to focus on the chemical form of Ru deposits and the form change after Ru addition when investigating the environmental fate of radioactive Ru.

CCDC28A deficiency causes head-tail coupling defects and immotility in murine spermatozoa

Male infertility presents a substantial challenge in reproductive medicine, often attributed to impaired sperm motility. The present study investigates the role of CCDC28A, a protein expressed specifically in male germ cells, whose paralog CCDC28B has been implicated in ciliogenesis. We identify unique expression patterns for CCDC28A and CCDC28B within the mouse testes, where CCDC28A is expressed in germ cells, whereas CCDC28B is expressed in supporting somatic cells. Through knockout mouse models and histological analyses, we reveal that CCDC28A deficiency results in diminished sperm motility and structural aberrations in sperm tails, notably affecting the head-tail coupling apparatus (HTCA), thereby causing male infertility. Fine structural analyses by transmission electron microscopy reveal disruptions at the capitulum-basal plate junction of the HTCA in the CCDC28A mutants. This results in the bending of the head within the neck region, often accompanied by thickening of the tail midpiece. Our discovery demonstrates that CCDC28A plays an essential role in male fertility and sperm tail morphogenesis through the formation of HTCA.

A Janus Platinum/Tin Oxide Heterostructure for Durable Oxygen Reduction Reaction.

Designing efficient and durable electrocatalysts for oxygen reduction reaction (ORR) is essential for proton exchange membrane fuel cells (PEMFCs). Platinum-based catalysts are considered efficient ORR catalysts due to their high activity. However, the degradation of Pt species leads to poor durability of catalysts, limiting their applications in PEMFCs. Herein, a Janus heterostructure is designed for high durability ORR in acidic media. The Janus heterostructure composes of crystalline platinum and cassiterite tin oxide nanoparticles with carbon support (J-Pt@SnO2/C). Based on the synchrotron fine structure analysis and electrochemical investigation, the crystalline reconstruction and charge redistribution at the interface of Janus structure are revealed. The tightly coupled interface could optimize the valance states of Pt and the adsorption/desorption of oxygenated intermediates. As a result, the J-Pt@SnO2/C catalyst possesses distinguishing long-term stability during the accelerated durability test without obvious degradation after 40000 cycles and keeps the majority of activity after 70000 cycles. Meanwhile, the catalyst exhibits outstanding activity with half-wave potential at 0.905V and a mass activity of 0.355AmgPt -1 (2.7 times higher than Pt/C). The approach of the Janus catalyst paves an avenue for designing highly efficient and stable Pt-based ORR catalyst in the future implementation.

Fine Structural Analysis of Degummed Fibroin Fibers Reveals Its Superior Mechanical Capabilities.

Bombyx mori silk fibroin fibers constitute a class of protein building blocks capable of functionalization and reprocessing into various material formats. The properties of these fibers are typically affected by the intense thermal treatments needed to remove the sericin gum coating layer. Additionally, their mechanical characteristics are often misinterpreted by assuming the asymmetrical cross-sectional area (CSA) as a perfect circle. The thermal treatments impact not only the mechanics of the degummed fibroin fibers, but also the structural configuration of the resolubilized protein, thereby limiting the performance of the resulting silk-based materials. To mitigate these limitations, we explored varying alkali conditions at low temperatures for surface treatment, effectively removing the sericin gum layer while preserving the molecular structure of the fibroin protein, thus, maintaining the hierarchical integrity of the exposed fibroin microfiber core. The precise determination of the initial CSA of the asymmetrical silk fibers led to a comprehensive analysis of their mechanical properties. Our findings indicate that the alkali surface treatment raised the Young's modulus and tensile strength, by increasing the extent of the fibers' crystallinity, by approximately 40 % and 50 %, respectively, without compromising their strain. Furthermore, we have shown that this treatment facilitated further production of high-purity soluble silk protein with rheological and self-assembly characteristics comparable to those of native silk feedstock, initially stored in the animal's silk gland. The developed approaches benefits both the development of silk-based materials with tailored properties and the proper mechanical characterization of asymmetrical fibrous biological materials made of natural building blocks.

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications for Metabolomics.

Metabolomics is an interdisciplinary field that aims to study all metabolites < 1500 Da that are ubiquitously found within all organisms. Metabolomics is experiencing exponential growth and commonly relies on high-resolution mass spectrometry (HRMS). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is a form of HRMS that is particularly well suited for metabolomics research due to its exceptionally high resolution (105-106) and sensitivity with a mass accuracy in parts per billion (ppb). In this regard, FT-ICR-MS can provide valuable insights into the metabolomics analysis of complex biological systems due to unique capabilities such as the easy separation of isobaric and isomeric species, isotopic fine structure analysis, spatial resolution of metabolites in cells and tissues, and a high confidence (<1 ppm mass error) in metabolite identification. Alternatively, the large and complex data sets, long acquisition times, high cost, and limited access mainly through national mass spectrometry facilities may impede the routine adoption of FT-ICR-MS by metabolomics researchers. This review examines recent applications of FT-ICR-MS metabolomics in the search for clinical and non-human biomarkers; for the analysis of food, beverage, and environmental samples; and for the high-resolution imaging of tissues and other biological samples. We provide recent examples of metabolomics studies that highlight the advantages of FT-ICR-MS for the detailed and reliable characterization of the metabolome. Additionally, we offer some practical considerations for implementing FT-ICR-MS into a research program by providing a list of FT-ICR-MS facilities and by identifying different high-throughput interfaces, varieties of sample types, analysis methods (e.g., van Krevelen diagrams, Kendrick mass defect plot, etc.), and sample preparation and handling protocols used in FT-ICR-MS experiments. Overall, FT-ICR-MS holds great promise as a vital research tool for advancing metabolomics investigations.

High precision in a Fourier-transform spectrum of protactinium: extensive weighted least-squares fits of peak wavenumbers for analysis of fine and hyperfine structure

A Fourier-transform recording of protactinium in the infrared range is reanalysed with high precision in order to determine the hyperfine interaction constants A and B. Starting with a selection of best lines and least-squares fits of hyperfine structure intervals, large systems of linear equations compare experimental hyperfine peak wavenumbers with a theoretical representation. The theoretical representation is based on Ritz’s combination principle and Casimir’s formula according to the existing classification. Weighted least-squares fits allow a discrimination between unperturbed and perturbed data such as blended hyperfine structure components. For the first time, the wavenumbers of the hyperfine components of more than 600 lines are fitted using the characteristics of about 250 levels as parameters. 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Representative examples illustrate extensive results obtained for atomic protactinium. This high precision facilitates further search for new energy levels, and 20 new levels were presented. Foreword The data presented here are the results of a study carried out at the Laboratoire Aimé Cotton (LAC) at Paris-Orsay in the years 2003 and 2004, when I was there for a research stay. At this time, I worked together with Jean-François Wyart and Annie Ginibre on the re-examination of protactinium spectra that have been measured about 30 years earlier and that were available in the form of a printed list of peak wavenumbers and a printed paper chart of the intensity profile. The spectra had already been analysed, but there was still a lot of additional information that could be extracted from the spectra with time and effort. The review of the data, the selection of the data and the step-by-step optimization of the data set took a lot of time. When I returned to Berlin in 2004, we had made good progress, but in principle, it is like a bottomless pit. We continued together to optimize the data and tried to the finishing touches to it. At some point, we decided that we had reached a ‘level of maturity’ where the data could be published. We have discussed a lot about how detailed the text should be. This discussion has dragged on over the years and this project has repeatedly been lost in the stream of other everyday tasks. Every now and then there was a small attempt to return to this topic, but it quickly got lost in the daily hustle and bustle. In 2012, we presented the results at a conference. The death of both of them within two years hit me hard. I very much regret that this work was not published earlier. This special volume was the right motivation for me to finally publish this data. I no longer have access neither to the computer programs used at the time, which ran on large computer systems, nor to the original measurement data. I have not been able to find out what happened to the large quantity of paper (printed list of peak wavenumbers anda printed paper chart of spectra). But I have a bunch of input and output files of the calculations that have become a bit jumbled over the years, which contain a lot of information, as well as our unfinished manuscript. The resulting data contain important information for posterity – particularly since the element is radioactive and the experiments to collect laboratory data are unlikely to be repeated any time soon. I think it is worth publishing these data.Graphic abstractHigh precision FT spectra of Pa: analysis of fine and hyperfine structure

Synergy of LIDAR and hyperspectral remote sensing: health status assessment of architectural heritage based on normal cloud theory and variable weight theory

Architectural heritage health assessment is the basis of scientific repair and maintenance. However, existing methods do not adequately take into account the fuzziness, randomness and uncertainties unique to architectural heritage assessment. In this paper, a new evaluation model of VM-NCM is constructed by combining variable weight theory and normal cloud model theory. The model enables the combination of qualitative ratings and quantitative calculation, deals with the fuzziness in the assessment process, and resolves the randomness and reflects the uncertainty to a certain extent. Based on constructing the index system combining qualitative and quantitative indexes, the structural index values are acquired by the synergistic coupling of the fine laser point cloud model and finite element structural analysis model. The acquisition of surface index values is completed by the hyperspectral intelligent detection technology of surface materials and diseases. These reduce the generation of ambiguous information in the index detection process. An evaluation study is conducted using the Yingxian wooden pagoda in China as an example. The results show that this method takes into account the fuzziness and randomness in the evaluation process, and obtains more scientific and reliable evaluation results, which provides a research paradigm for assessing the architectural heritage health status.

A hybrid one‐step leapfrog ADI‐FDTD and subgridding approach based on a heterogeneous computing platform

AbstractThe finite‐difference time‐domain (FDTD) method often demands numerous grids for fine structure analysis, leading to high computational costs. To address this challenge, a subgridding scheme emerges as an attractive solution. However, the explicit nature of the FDTD subgrid method, constrained by Courant–Friedrichs–Lewy (CFL) conditions, can lead to inefficiencies with complex structures. In response, the leapfrog alternating‐direction implicit (ADI)‐FDTD method, exhibiting unconditional stability, has been developed to overcome CFL limitations. This paper presents a hybrid approach merging the one‐step leapfrog ADI‐FDTD method with a subgridding scheme using heterogeneous computing. By optimizing hardware usage and leveraging different device performances, this approach maximizes throughput in heterogeneous systems. Central processing units and graphics processing units handle workloads to minimize system latency. Simulation results on heterogeneous platforms demonstrate superior efficiency over single processor setups while maintaining simulation accuracy, especially in analyzing electromagnetic scattering from multiscale structures.

A wide-band, high-resolution semi-von Hamos spectrometer for K-shell multi-ionization atoms X-ray measurements

A wide-band, high-resolution vacuum semi-von Hamos spectrometer has been developed for analyzing the X-rays spectra of K-shell multi-ionization atoms. The spectrometer covers an energy dynamic range of 0.6 to 18 keV with a corresponding single exposure spectral bandwidth of 0.25–1.2 keV. This capability is achieved by the combination of different cylindrically bent crystals and an X-ray CCD detector mounted on a twistable bellows, allowing modulation of the Bragg angles from 27° to 47°. A detailed mathematical description is employed to understand the dependence of the geometrical parameters of the spectrometer on the imaging properties, energy spectrum bandwidth, resolving power, solid angle, and other relevant spectrometer characteristics. An energy calibration has been performed by using K X-rays generated by 10–30 keV electron beam interactions with solid KCl, CaF2 and Se targets. The spectrometer exhibits a resolving power better than 103, enabling the analysis of fine spectral structure of K X-ray transitions and the comparison of X-ray properties between pure elements and their compounds due to chemical effects. The spectrometer also finds applications in various fields requiring precise X-ray measurements, including synchrotron radiation experiments, tokamaks, laser plasma diagnostics and laboratory astrophysics.

The features of dome-shape Macula and related complications in high myopia on optical coherence tomography.

This study used optical coherence tomography scanning and 3D reconstruction of the macular region in high myopia to examine more thoroughly and carefully the differences between high myopia-related macular complications with and without dome-shape macula (DSM) and to determine whether the DSM's fine structure has an effect on them. Retrospective analysis of the medical records of 345 eyes with high myopia who underwent an optical coherence tomography (OCT) examination. They were divided into the DSM group (69 eyes) and the group without DSM (276 eyes). Macular complications between the two groups were compared. The height of the DSM and the diameter of the dome base were measured. And then the association between DSM type, protrusion height and macular problems were analyzed. Epiretinal membrane (ERM) and extrafoveal schisis occurred more frequently in the DSM group, but the was no statistically significant difference in the frequency of foveal schisis between the two groups. The majority of eyes in the DSM categorization had a horizontal oval-shaped domain. In the DSM group, there was no evident difference in the percentage of eyes with macular complications in the groups below 150 um and above 150 um. OCT examination-based fine macular structure analysis reveals that DSM affects various macular problems in distinct ways. DSM could increase the risk of extrafoveal schisis and ERM while decreasing the risk of foveal schisis. The height of the DSM had no obvious impact on the prevalence of macular complications.

Unveiling the significant promoting effect of SO2 on Ir/SiO2 catalyst for the CO-SCR of NOx in the presence of O2

Selective catalytic reduction of NOx by CO (CO-SCR) in the presence of O2 is challenging because in this process CO is prone to being oxidized by O2, thus inhibiting NOx reduction by CO. Furthermore, SO2 typically leads to the deactivation of the CO-SCR catalyst. Herein, a significant promoting effect of SO2 on Ir/SiO2 catalyst for the CO-SCR of NOx in the presence of O2 is reported. In-situ X-ray Absorption Fine Structure (XAFS) and X-ray photoelectron spectroscopy (XPS) analysis showed that SO2 does not affect the chemical nature of Ir0 under reaction conditions. However, SO2 can be oxidized to sulfate and deposit on the catalyst surface. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis demonstrated that the presence of SO2 can inhibit the CO + O2 reaction, thus leaving more CO available to reduce NOx over the active Ir0 sites. As a result, the reduction of NOx is remarkably promoted even in the presence of O2 and SO2.

A Fine Analysis of Zn Species Structure and Distribution in Zn/ZSM-5 Catalysts by Linear Combination Fitting Analysis of XANES Spectra

Investigating the distribution of different Zn species on Zn-containing zeolite catalysts is crucial for identifying the active sites and establishing the relationship between the catalyst’s structure and its activity in the process of ethylene aromatization. By utilizing X-ray absorption near edge spectra (XANES) of various reference samples, this study employed linear combination fitting (LCF) analysis on XANES spectra of real samples to accurately measure the changes in the distribution of Zn species in Zn-containing HZSM-5 zeolites under different Zn sources and loadings. The results showed that ZnOH+, ZnO clusters, and ZnO crystalline structures coexist in Zn/HZSM-5 catalysts prepared through physical mixing and incipient wet impregnation methods. A similar trend was observed for catalysts prepared using different methods, with an increase in Zn content resulting in a decrease in the proportion of ZnOH+ and a significant increase in the amount of larger ZnO crystals. Furthermore, ZnO clusters were confined within the zeolite pores. The findings of this study established a direct correlation between the amount of ZnOH+ determined through LCF analysis and both the rate of hydrogen production and the rate of aromatics formation, providing strong evidence for the catalytic role of ZnOH+ as an active center for dehydrogenation, which plays a key role in promoting the formation of aromatics. The method of LCF analysis on XANES spectra allows for the determination of the local structure of Zn species, facilitating a more precise analysis based on the distribution of these species. This method not only provides detailed information about the Zn species but also enhances the accuracy of the overall analysis.

Dirac equation and its contribution to atomic fine structure

This article aims to establish the comprehensiveness of the Dirac equation as an effective modification of quantum mechanics for the analysis of electrons and atomic fine structure. The Dirac equation is applied to investigate two scenarios involving electron interactions with different potentials. In the case where =0, the Dirac equation aligns naturally with electron theories and yields an electron gyromagnetic factor of g_s=2. With additional radiative corrections, it is possible to bring this value into closer proximity to experimental results. On the other hand, when considering spin-orbit coupling within a central field of V=(-e^2)r, the spin-orbit Hamiltonian derived from the Dirac equation is shown to match calculations based on Larmor and Thomas interactions. These cases collectively demonstrate the superior utility of Diracs theory when dealing with spin-1/2 particles like electrons, underscoring Diracs historical success in addressing the complexities of the time. His achievements in elucidating atomic fine structure and spin-orbit coupling hold pivotal significance for advancing technologies rooted in these theories. However, it is important to note that the Dirac equation primarily remains valid in weak external field situations, as observed in electron orbital motion, while challenges persist in unifying it with general relativity in stronger external field contexts.

106-fold faster C-H bond hydroxylation by a CoIII,IV2(µ-O)2 complex [via a CoIII2(µ-O)(µ-OH) intermediate] versus its FeIIIFeIV analog.

The hydroxylation of C-H bonds can be carried out by the high-valent CoIII,IV2(µ-O)2 complex 2a supported by the tetradentate tris(2-pyridylmethyl)amine ligand via a CoIII2(µ-O)(µ-OH) intermediate (3a). Complex 3a can be independently generated either by H-atom transfer (HAT) in the reaction of 2a with phenols as the H-atom donor or protonation of its conjugate base, the CoIII2(µ-O)2 complex 1a. Resonance Raman spectra of these three complexes reveal oxygen-isotope-sensitive vibrations at 560 to 590 cm-1 associated with the symmetric Co-O-Co stretching mode of the Co2O2 diamond core. Together with a Co•••Co distance of 2.78(2) Å previously identified for 1a and 2a by Extended X-ray Absorption Fine Structure (EXAFS) analysis, these results provide solid evidence for their "diamond core" structural assignments. The independent generation of 3a allows us to investigate HAT reactions of 2a with phenols in detail, measure the redox potential and pKa of the system, and calculate the O-H bond strength (DO-H) of 3a to shed light on the C-H bond activation reactivity of 2a. Complex 3a is found to be able to transfer its hydroxyl ligand onto the trityl radical to form the hydroxylated product, representing a direct experimental observation of such a reaction by a dinuclear cobalt complex. Surprisingly, reactivity comparisons reveal 2a to be 106-fold more reactive in oxidizing hydrocarbon C-H bonds than corresponding FeIII,IV2(µ-O)2 and MnIII,IV2(µ-O)2 analogs, an unexpected outcome that raises the prospects for using CoIII,IV2(µ-O)2 species to oxidize alkane C-H bonds.

Accumulation of Ag(0) Single Atoms at Water/Mineral Interfaces during Sunlight-Induced Reduction of Ionic Ag by Phenolic DOM.

Silver (Ag) undergoes a complex and dynamic Ag+/Ag0 cycle under environmental conditions. The Ag+ → Ag nanoparticles (AgNPs) transformation due to the combined actions of sunlight, O2, and dissolved organic matter has been a well-known environmental phenomenon. In this study, we indicate that this process may be accompanied by a pronounced accumulation of Ag(0) single atoms (Ag-SAs) on the minerals' surfaces. According to spherical aberration-corrected scanning transmission electron microscopy and high-energy-resolution X-ray adsorption fine structure analyses, humic acid (HA) and phenol (PhOH) can induce Ag-SAs accumulation, whereas oxalic acid causes only AgNPs deposition. Ag-SAs account for more than 20 wt % of total Ag(0) on the γ-Al2O3 surfaces during HA- and PhOH-mediated photolysis processes. HA also causes Ag-SAs to accumulate on two other prevalent soil minerals, SiO2 and Fe2O3, and the fractions of Ag-SAs are about 15 wt %. Our mechanism studies suggest that a phenolic molecule acts as a reducing agent of Ag+ and a stabilizer of Ag-SAs, protecting Ag-SAs against autocatalytic nucleation.

Exploring the partial degradation of polysaccharides: Structure, mechanism, bioactivities, and perspectives.

Polysaccharides are promising biomolecules with lowtoxicity and diverse bioactivities in food processing and clinical drug development. However, an essential prerequisite for their applications is the fine structure characterization. Due to the complexity of polysaccharide structure, partial degradation is a powerful tool for fine structure analysis, which can effectively provide valid information on the structure of backbone and branching glycosidic fragments of complex polysaccharides. This review aims to conclude current methods of partial degradation employed for polysaccharide structural characterization, discuss the molecular mechanisms, and describe the molecular structure and solution properties of degraded polysaccharides. In addition, the effects of polysaccharide degradation on the conformational relationships between the molecular structure and bioactivities, such as antioxidant, antitumor, and immunomodulatory activities, are also discussed. Finally, we summarize the prospects and current challenges for the partial degradation of polysaccharides. This review will be of great value for the scientific elucidation of polysaccharide fine structures and potential applications.

AQcalc: A web server that identifies weak molecular interactions in protein structures.

Weak molecular interactions play an important role in protein structure and function. Computational tools that identify weak molecular interactions are, therefore, valuable for the study of proteins. Here, we present AQcalc, a web server (https://aqcalcbiocomputing.com/) that can be used to identify anion-quadrupole (AQ) interactions, which are weak interactions involving aromatic residue (Trp, Tyr, and Phe) ring edges and anions (Asp, Glu, and phosphate ion) both within proteins and at their interfaces (protein-protein, protein-nucleic acids, and protein-lipid bilayer). AQcalc identifies AQ interactions as well as clusters involving AQ, cation-π, and salt bridges, among others. Utilizing AQcalc we analyzed weak interactions in protein models, even in the absence of experimental structures, to understand the contributions of weak interactions to deleterious structural changes, including those associated with oncogenic and germline disease variants. We identified several deleterious variants with disrupted AQ interactions (comparable in frequency to cation-π disruptions). Amyloid fibrils utilize AQ to bury anions at frequencies that far exceed those observed for globular proteins. AQ interactions were detected three and five times more frequently than the hydrogen-bonded AQ (HBAQ) in fibril structures and protein-lipid bilayer interfaces, respectively. By contrast, AQ and HBAQ interactions were detected with similar frequencies in globular proteins. Collectively, these findings suggest AQcalc will be effective in facilitating fine structural analysis. As other web utilities designed to identify protein residue interaction networks do not report AQ interactions, wide use of AQcalc will enrich our understanding of residue interaction networks and facilitate hypothesis testing by identifying and experimentally characterizing these comparably weak but important interactions.

Typical Fine Structure and Seismogenic Mechanism Analysis of the Surface Rupture of the 2022 Menyuan Mw 6.7 Earthquake

On 8 January 2022, a seismic event of significant magnitude (Mw 6.7, Ms 6.9) occurred in the northeastern region of the Tibetan Plateau. This earthquake was characterized by left-lateral strike-slip motion, accompanied by a minor reverse movement. The Menyuan earthquake resulted in the formation of two main ruptures and one secondary rupture. These ruptures were marked by a left-lateral step zone that extended over a distance of 1 km between the main ruptures. The length of the rupture zones was approximately 37 km. The surface rupture zone exhibited various features, including left-lateral offset small gullies, riverbeds, wire fences, road subgrades, mole tracks, cracks, and scarps. Through a comprehensive field investigation and precise measurement using unmanned aerial vehicle (UAV) imagery, 111 coseismic horizontal offsets were determined, with the maximum offset recorded at 2.6 ± 0.3 m. The analysis of aftershocks and the findings from the field investigation led to the conclusion that the earthquake was triggered by the Lenglongling fault and the Tuolaishan fault. These faults intersected at a release double-curved structure, commonly referred to as a stepover. During this particular process, the Lenglongling fault was responsible for initiating the coseismic rupture of the Sunan–Qilian fault. It is important to note that the stress applied to the Tuolaishan fault has not been fully relieved, indicating the presence of potential future hazards.

Metal Site-Specific Electrostatic Field Effects on a Tricopper(I) Cluster Probed by Resonant Diffraction Anomalous Fine Structure (DAFS).

Studies of multinuclear metal complexes are greatly enhanced by resonant diffraction measurements, which probe X-ray absorption profiles of crystallographically independent metal sites within a cluster. In particular, X-ray diffraction anomalous fine structure (DAFS) analysis provides data that can be interpreted akin to site-specific XANES, allowing for differences in metal K-edge resonances to be deconvoluted even for different metal sites within a homometallic system. Despite the prevalence of Cu-containing clusters in biology and energy science, DAFS has yet to be used to analyze multicopper complexes of any type until now. Here, we report an evaluation of trends using a series of strategically chosen Cu(I) and Cu(II) complexes to determine how energy dependencies of anomalous scattering factors are impacted by coordination geometry, ligand shell, cluster nuclearity, and oxidation state. This calibration data is used to analyze a formally tricopper(I) complex that was found by DAFS to be site-differentiated due to the unsymmetrical influence on different Cu sites of the electrostatic field from a proximal K+ cation.