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20 pages, 1753 KiB  
Article
Vitamin E Enhances Immune Function and the Intestinal Histological Structure by Regulating the Nodal-Mediated Signaling Pathway: A Case Study on the Sea Cucumber Apostichopus japonicus
by Zitong Wang, Yan Wang, Xianyu Wang, Guangyao Zhao, Haiqing Zeng, Haoran Xiao, Lingshu Han, Jun Ding, Yaqing Chang and Rantao Zuo
Biology 2025, 14(8), 1008; https://doi.org/10.3390/biology14081008 - 6 Aug 2025
Abstract
The histological integrity of the intestine depends on the tight and orderly arrangement of epithelial cells within the intestinal villi. Nodal, a transforming growth factor-β (TGF-β) family member, has been reported to promote epithelial cell proliferation. Collagen not only establishes physical connections [...] Read more.
The histological integrity of the intestine depends on the tight and orderly arrangement of epithelial cells within the intestinal villi. Nodal, a transforming growth factor-β (TGF-β) family member, has been reported to promote epithelial cell proliferation. Collagen not only establishes physical connections between adjacent cells but also serves as an anchoring platform for cell adhesion and regeneration processes. Therefore, a 21-day feeding trial was conducted using RNA interference to investigate the role of the Nodal gene in regulating intestinal collagen synthesis and histological structure integrity in juvenile A. japonicus fed diets containing graded levels of vitamin E (VE) (0, 200, and 400 mg/kg). The results showed that the addition of 200 mg/kg VE significantly improved the growth rate, immune enzyme activities and related gene expression, as well as intestinal villus morphology. Additionally, the addition of 200 mg/kg VE upregulated the expression of Nodal, which activated the expression of collagen synthesis-related genes and promoted collagen deposition in the intestines of A. japonicus. After Nodal gene knockdown, A. japonicus presented a decreased growth rate, damage to the intestinal histological structure, and impaired collagen synthesis, with the most notable findings observed in A. japonicus fed diets without VE addition. However, these detrimental effects were eliminated to some extent by the addition of 200 mg/kg VE. These findings indicate that VE improves immune function and intestinal histological structure in A. japonicus through a Nodal-dependent pathway. Full article
(This article belongs to the Special Issue Current Advances in Echinoderm Research (2nd Edition))
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28 pages, 9663 KiB  
Article
Investigation on Structural Performance of Integral Steel Wall Plate Structure in Cable–Pylon Anchorage Zone
by Chen Liang, Yuqing Liu, Yimin Liu and Chi Lu
Appl. Sci. 2025, 15(15), 8672; https://doi.org/10.3390/app15158672 (registering DOI) - 5 Aug 2025
Abstract
To enhance the bearing capacity of cable–pylon anchorage zones in cable-stayed bridges, this paper proposes the integral steel wall plate (IWP) structure and investigates the structural performance of its application in anchorage zones with a steel anchor beam and with a steel anchor [...] Read more.
To enhance the bearing capacity of cable–pylon anchorage zones in cable-stayed bridges, this paper proposes the integral steel wall plate (IWP) structure and investigates the structural performance of its application in anchorage zones with a steel anchor beam and with a steel anchor box. The proposed structure contains an end plate, a surface plate, and several perforated side plates, forming steel cabins that encase the concrete pylon wall, where the steel and concrete are connected by perfobond connectors on side plates. A half-scaled experiment and a finite element analysis were first conducted on the IWP with the steel anchor beam to study the deformation at the steel–concrete interface, as well as the stress distribution in steel plates and rebars. The results were compared with experimental data of a conventional type of anchorage zone. Then, finite element models of anchorages with steel anchor boxes were established based on the geometries of an as-built bridge, and the performance of the IWP structure was compared with conventional details. Finally, the effects of plate thickness and connector arrangement were investigated. Results show that the proposed IWP structure offers excellent performance when applied with an anchor beam or anchor box, and it can effectively reduce principal tensile stress on the concrete pylon wall compared with conventional anchorage details. Full article
(This article belongs to the Section Civil Engineering)
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21 pages, 15647 KiB  
Article
Research on Oriented Object Detection in Aerial Images Based on Architecture Search with Decoupled Detection Heads
by Yuzhe Kang, Bohao Zheng and Wei Shen
Appl. Sci. 2025, 15(15), 8370; https://doi.org/10.3390/app15158370 - 28 Jul 2025
Viewed by 259
Abstract
Object detection in aerial images can provide great support in traffic planning, national defense reconnaissance, hydrographic surveys, infrastructure construction, and other fields. Objects in aerial images are characterized by small pixel–area ratios, dense arrangements between objects, and arbitrary inclination angles. In response to [...] Read more.
Object detection in aerial images can provide great support in traffic planning, national defense reconnaissance, hydrographic surveys, infrastructure construction, and other fields. Objects in aerial images are characterized by small pixel–area ratios, dense arrangements between objects, and arbitrary inclination angles. In response to these characteristics and problems, we improved the feature extraction network Inception-ResNet using the Fast Architecture Search (FAS) module and proposed a one-stage anchor-free rotation object detector. The structure of the object detector is simple and only consists of convolution layers, which reduces the number of model parameters. At the same time, the label sampling strategy in the training process is optimized to resolve the problem of insufficient sampling. Finally, a decoupled object detection head is used to separate the bounding box regression task from the object classification task. The experimental results show that the proposed method achieves mean average precision (mAP) of 82.6%, 79.5%, and 89.1% on the DOTA1.0, DOTA1.5, and HRSC2016 datasets, respectively, and the detection speed reaches 24.4 FPS, which can meet the needs of real-time detection. Full article
(This article belongs to the Special Issue Innovative Applications of Artificial Intelligence in Engineering)
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25 pages, 2940 KiB  
Article
Sustainability in Action: Analyzing Mahasarakham University’s Integration of SDGs in Education, Research, and Operations
by Woraluck Sribanasarn, Anujit Phumiphan, Siwa Kaewplang, Mathinee Khotdee, Ounla Sivanpheng and Anongrit Kangrang
Sustainability 2025, 17(14), 6378; https://doi.org/10.3390/su17146378 - 11 Jul 2025
Viewed by 416
Abstract
The UI GreenMetric World University Ranking has become a widely adopted instrument for benchmarking institutional sustainability performance; nevertheless, empirically grounded evidence from universities in diverse regional contexts remains scarce. This study undertakes a rigorous appraisal of the extent to which Mahasarakham University (MSU) [...] Read more.
The UI GreenMetric World University Ranking has become a widely adopted instrument for benchmarking institutional sustainability performance; nevertheless, empirically grounded evidence from universities in diverse regional contexts remains scarce. This study undertakes a rigorous appraisal of the extent to which Mahasarakham University (MSU) has institutionalized the United Nations Sustainable Development Goals (SDGs) within its pedagogical offerings, research portfolio, community outreach, and governance arrangements during the 2021–2024 strategic cycle. Employing a mixed-methods design and guided by the 2024 UI GreenMetric Education and Research indicators, this investigation analyzed institutional datasets pertaining to curriculum provision, ring-fenced research funding, 574 peer-reviewed sustainability publications, student-led community initiatives, and supporting governance mechanisms; the analysis was interpreted through a Plan–Do–Check–Act management lens. The number of sustainability-oriented academic programs expanded from 49 to 58. Student participation in community service activities strongly recovered following the COVID-19 pandemic, and MSU’s GreenMetric score increased from 7575 to 8475, thereby elevating the institution to the 100th position globally. These gains were facilitated by strategic SDG-aligned investment, cross-sector collaboration, and the consolidation of international partnerships anchored in Thailand’s Isaan region. The MSU case provides a transferable model for universities—particularly those operating in resource-constrained contexts—endeavoring to align institutional development with the SDGs and internationally recognized quality benchmarks. The findings substantiate the capacity of transformative education and applied research to engender enduring societal and environmental benefits. Full article
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21 pages, 4313 KiB  
Article
Heat Shock Protein and Disaggregase Influencing the Casein Structuralisation
by Irena Roterman, Katarzyna Stapor, Dawid Dułak and Leszek Konieczny
Int. J. Mol. Sci. 2025, 26(13), 6360; https://doi.org/10.3390/ijms26136360 - 1 Jul 2025
Viewed by 299
Abstract
The contribution of the environment to protein folding seems obvious. The aqueous environment directs protein folding towards generating a centric hydrophobic core with a polar shell. The cell membrane environment—in which numerous proteins are anchored—to stabilise the arrangement, expects the exposure of hydrophobic [...] Read more.
The contribution of the environment to protein folding seems obvious. The aqueous environment directs protein folding towards generating a centric hydrophobic core with a polar shell. The cell membrane environment—in which numerous proteins are anchored—to stabilise the arrangement, expects the exposure of hydrophobic residues and the concentration of polar residues in the central part—a channel for the transport of numerous molecules. The influence of these environments seems evident due to the persistent residence of proteins in their surroundings providing an external force field for structure stabilisation. Structural forms are also obtained with the participation of supporting proteins—such as proteins from the heat shock protein group—which accompany the folding process and temporarily provide an appropriate external force field in which the protein, having obtained the correct structure for its activity, is released from interaction with the supporting protein. This paper discusses an example of the contribution of Hsp104 to casein folding and the effect of disaggregase preventing inappropriate aggregation. For this purpose, a model called the fuzzy oil drop (FOD-M) was used, which takes hydrophobic interactions into account in the assessment of protein structure status. Their distribution in the protein body highlights the contribution and influence of the external force field—originating from Hsp104 and the disaggregase in this case. Full article
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23 pages, 3242 KiB  
Hypothesis
Vaxtherapy, a Multiphase Therapeutic Protocol Approach for Longvax, the COVID-19 Vaccine-Induced Disease: Spike Persistence as the Core Culprit and Its Downstream Effects
by Jose Crespo-Barrios
Diseases 2025, 13(7), 204; https://doi.org/10.3390/diseases13070204 - 30 Jun 2025
Viewed by 2059
Abstract
Background/Objectives: Chronic illness after COVID-19 vaccination (longvax) lacks a therapeutic protocol anchored in pathophysiology. Persistent vaccine derived spike protein appears to trigger microvascular fibrin amyloid microclots, immune dysfunction, pathogen reactivation and multisystem injury. This article proposes an integrative approach, Vaxtherapy, to tackle these [...] Read more.
Background/Objectives: Chronic illness after COVID-19 vaccination (longvax) lacks a therapeutic protocol anchored in pathophysiology. Persistent vaccine derived spike protein appears to trigger microvascular fibrin amyloid microclots, immune dysfunction, pathogen reactivation and multisystem injury. This article proposes an integrative approach, Vaxtherapy, to tackle these mechanisms. Methods: A narrative synthesis of peer reviewed literature from 2021 to 2025 on spike related injury and vaccine adverse events was conducted, supplemented by clinical case series and mechanistic observations from long COVID. The findings were arranged into a four stage therapeutic sequence ordered by pathophysiological precedence. Results: Stage one aims to reopen hypoperfused tissue through oral fibrinolytics that degrade fibrin amyloid resistant microclots; stage two intends to neutralise circulating or tissue bound spike via a receptor binding domain monoclonal antibody cocktail; stage three seeks to eliminate reactivated viral or microbial reservoirs with targeted antivirals or antimicrobials once perfusion is improved; and stage four aspires to support tissue repair with mitochondrial supplements and, when indicated, cell based therapies. Omitting or reordering stages may reduce efficacy or foster resistance. Conclusions: This hypothesis driven framework outlines a biologically plausible roadmap for longvax research. By matching interventions to specific mechanisms (fibrinolysis, spike neutralisation, pathogen clearance and regeneration), it aims to guide controlled trials and compassionate pilot programs directed at durable recovery rather than chronic symptom management. Full article
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14 pages, 3364 KiB  
Article
Selection of an Optimum Anchoring Method of Composite Rock Stratum Based on Anchor Bolt Support Prestress Field
by Yiqun Zhou, Jianwei Yang, Chenyang Zhang, Dingyi Li and Bin Hu
Appl. Sci. 2025, 15(13), 6990; https://doi.org/10.3390/app15136990 - 20 Jun 2025
Viewed by 324
Abstract
In order to make the anchor bolt support prestress field fully diffuse in the composite rock stratum, improve the overall bearing capacity of surrounding rock, and give full play to the role of active support of the anchor bolt, a self-made 1:1-scale composite [...] Read more.
In order to make the anchor bolt support prestress field fully diffuse in the composite rock stratum, improve the overall bearing capacity of surrounding rock, and give full play to the role of active support of the anchor bolt, a self-made 1:1-scale composite rock stratum similarity simulation test bed was used to compare and analyze the distribution of the anchor bolt support prestress field using different anchoring surrounding rock lithology and anchorage lengths, and the principle for optimum selection of anchoring parameters of composite rock stratum was proposed based on the test results. Considered from the point of view of stress diffusion, the effect of prestress diffusion of end anchorage bolts is better than that of lengthening anchorage; at the same time, the anchorage section should be preferentially arranged in hard rock, and the area of anchorage section near the free section should avoid the structural plane of surrounding rock. In conclusion, an industrial test was carried out under the conditions of a deep composite roof of the 2# coal seam in Qinyuan Mining Area, which determined a reasonable anchoring method and position of the composite roof under different conditions and achieved good results. Full article
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13 pages, 4001 KiB  
Article
Growing Nanocrystalline Ru on Amorphous/Crystalline Heterostructure for Efficient and Durable Hydrogen Evolution Reaction
by Quanbin Huang, Xu Zhang, Li Tong, Yipu Liu and Shiwei Lin
Catalysts 2025, 15(5), 434; https://doi.org/10.3390/catal15050434 - 29 Apr 2025
Viewed by 567
Abstract
The design of efficient hydrogen evolution reaction (HER) catalysts to minimize reaction overpotentials plays a pivotal role in advancing water electrolysis and clean energy solutions. Ru-based catalysts, regarded as potential replacements for Pt-based catalysts, face stability challenges during catalytic process. The precise regulation [...] Read more.
The design of efficient hydrogen evolution reaction (HER) catalysts to minimize reaction overpotentials plays a pivotal role in advancing water electrolysis and clean energy solutions. Ru-based catalysts, regarded as potential replacements for Pt-based catalysts, face stability challenges during catalytic process. The precise regulation of metal–support interactions effectively prevents Ru nanoparticle degradation while optimizing interfacial electronic properties, enabling the simultaneous enhancement of catalytic activity and stability. Herein, we design an amorphous/crystalline support and employ in situ replacement to develop a Ru-NiPx-Ni structure. The crystalline Ni phase with ordered atomic arrangement ensures efficient charge transport, while the amorphous phase with unsaturated dangling bonds provides abundant anchoring sites for Ru nanoclusters. This synergistic structure significantly enhances HER performance, which attains overpotentials of 19 mV at 10 mA cm−2 and 70 mV at 100 mA cm−2 in 1 m KOH, with sustained operation exceeding 55 h at 100 mA cm−2. Electrochemical impedance spectroscopy analysis confirms that the Ru-NiPx-Ni structure not only has a high density of active centers for HER, but also reduces the charge transfer resistance at the electrode–electrolyte interface, which effectively enhances HER kinetics. This study presents new directions for designing high-efficiency HER catalysts. Full article
(This article belongs to the Section Photocatalysis)
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35 pages, 15716 KiB  
Article
Experimental Study of the Hydrodynamic Forces of Pontoon Raft Aquaculture Facilities Around a Wind Farm Monopile Under Wave Conditions
by Deming Chen, Mingchen Lin, Jinxin Zhou, Yanli Tang, Fenfang Zhao, Xinxin Wang, Mengjie Yu, Qiao Li and Daisuke Kitazawa
J. Mar. Sci. Eng. 2025, 13(4), 809; https://doi.org/10.3390/jmse13040809 - 18 Apr 2025
Viewed by 510
Abstract
The integrated development of offshore wind power and marine aquaculture represents a promising approach to the sustainable utilization of ocean resources. The present study investigated the hydrodynamic response of an innovative combination of a wind farm monopile and pontoon raft aquaculture facilities (PRAFs). [...] Read more.
The integrated development of offshore wind power and marine aquaculture represents a promising approach to the sustainable utilization of ocean resources. The present study investigated the hydrodynamic response of an innovative combination of a wind farm monopile and pontoon raft aquaculture facilities (PRAFs). Physical water tank experiments were conducted on PRAFs deployed around a wind farm monopile using the following configurations: single- and three-row arrangements of PRAFs with and without a monopile. The interaction between the aquaculture structure and the wind farm monopile was examined, with a particular focus on the mooring line tensions and bridle line tensions under different wave conditions. Utilizing the wind farm monopile foundation as an anchor, the mooring line tension was reduced significantly by 16–66% in the single-row PRAF. The multi-row PRAF arrangement experienced lower mooring line tension in comparison with the single-row PRAF arrangement, with the highest reduction of 73%. However, for the bridle line tension, the upstream component was enhanced, while the downstream one was weakened with a monopile, and they both decreased in the multi-row arrangement. Finally, we developed numerical models based on flume tank tests that examined the interactions between the monopile and PRAFs, including configurations of a single monopile, along with single- and three-row arrangements of PRAFs. The numerical simulation results confirmed that the monopile had a dampening effect on the wave propagation of 5% to 20%, and the impact of the pontoons on the monopile was negligible, implying that the integration of aquaculture facilities around wind farm infrastructure may not significantly alter the hydrodynamic loads experienced by the monopile. Full article
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18 pages, 20102 KiB  
Article
Time-Domain Simulation of Coupled Motions for Five Fishing Vessels Moored Side-by-Side in a Harbor
by Xuran Men, Jinlong He, Bo Jiao, Guibing Zhu, Haihua Lin and Hongyuan Sun
J. Mar. Sci. Eng. 2025, 13(2), 307; https://doi.org/10.3390/jmse13020307 - 7 Feb 2025
Viewed by 942
Abstract
With the rapid development and accelerated utilization of marine resources, multi-body floating systems have become extensively used in practical applications. This study examines the coupled motions of a side-by-side anchoring system for five fishing vessels in a harbor using ANSYS-AQWA. The system is [...] Read more.
With the rapid development and accelerated utilization of marine resources, multi-body floating systems have become extensively used in practical applications. This study examines the coupled motions of a side-by-side anchoring system for five fishing vessels in a harbor using ANSYS-AQWA. The system is connected by hawsers and equipped with fenders to reduce collisions between the vessels. It is designed to operate in the sheltered wind-wave combined environment within Ningbo Zhoushan Port, China. Considering the diverse types and quantities of fishing vessels in the anchorage area, this paper proposes a mixed arrangement of three large-scale fishing vessels in the middle and two small-scale vessels on both sides. The time-domain analysis is performed on this system under the combined effects of wind and waves, calculating the motion responses of the five fishing vessels along with the mechanical loads at the hawsers, fenders, and moorings. The results indicate that the maximum loads on these mechanical components remain well within the safe working limits, ensuring reliable operation. In addition, the impact of varying wind-wave angles on the coupled motions of the fishing vessel system are studied. As the wind-wave angle increases, the surge motion of the fishing vessels gradually decreases, while the sway motion intensifies. The forces on the hawsers, fenders, and mooring system exhibit distinct characteristics at different angles. Full article
(This article belongs to the Section Ocean Engineering)
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24 pages, 2465 KiB  
Article
Enantiopure Turbo Chirality Targets in Tri-Propeller Blades: Design, Asymmetric Synthesis, and Computational Analysis
by Yu Wang, Ting Xu, Ankit Pandey, Shengzhou Jin, Jasmine X. Yan, Qingkai Yuan, Sai Zhang, Jia-Yin Wang, Ruibin Liang and Guigen Li
Molecules 2025, 30(3), 603; https://doi.org/10.3390/molecules30030603 - 29 Jan 2025
Cited by 1 | Viewed by 974
Abstract
Enantiopure turbo chirality in small organic molecules, without other chiral elements, is a fascinating topic that has garnered significant interest within the chemical and materials science community. However, further research into and application of this concept have been severely limited by the lack [...] Read more.
Enantiopure turbo chirality in small organic molecules, without other chiral elements, is a fascinating topic that has garnered significant interest within the chemical and materials science community. However, further research into and application of this concept have been severely limited by the lack of effective asymmetric tools. To date, only a few enantiomers of turbo chiral targets have been isolated, and these were obtained through physical separation using chiral HPLC, typically on milligram scales. In this work, we report the first asymmetric approach to enantiopure turbo chirality in the absence of other chiral elements such as central and axial chirality. This is demonstrated by assembling aromatic phosphine oxides, where three propeller-like groups are anchored to a P(O) center via three axes. Asymmetric induction was successfully carried out using a chiral sulfonimine auxiliary, with absolute configurations and conformations unambiguously determined by X-ray diffraction analysis. The resulting turbo frameworks exhibit three propellers arranged in either a clockwise (P,P,P) or counterclockwise (M,M,M) configuration. In these arrangements, the bulkier sides of the aromatic rings are oriented toward the oxygen atom of the P=O bond rather than in the opposite direction. Additionally, the orientational configuration is controlled by the sulfonimine auxiliary as well, showing that one of the Naph rings is pushed away from the auxiliary group (-CH2-NHSO2-tBu) of the phenyl ring. Computational studies were conducted on relative energies for the rotational barriers of a turbo target along the P=O axis and the transition pathway between two enantiomers, meeting our expectations. This work is expected to have a significant impact on the fields of chemistry, biomedicine, and materials science in the future. Full article
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23 pages, 9476 KiB  
Article
Investigation of Bolt Support Mechanisms and Parameter Optimization for Hard Roof Control in Underground Mining
by Cong Wang, Xigui Zheng, Wei Xin, Jiyu Wang and Longhe Liu
Processes 2025, 13(1), 94; https://doi.org/10.3390/pr13010094 - 3 Jan 2025
Cited by 2 | Viewed by 908
Abstract
The control of hard roof conditions in underground coal mining is critical for ensuring mining safety and efficiency. Hard roof control remains a critical challenge in underground mining, particularly affecting mining safety and efficiency. Traditional support theories often show limitations in addressing the [...] Read more.
The control of hard roof conditions in underground coal mining is critical for ensuring mining safety and efficiency. Hard roof control remains a critical challenge in underground mining, particularly affecting mining safety and efficiency. Traditional support theories often show limitations in addressing the complex interactions between bolt spacing patterns and geological variability. This study focuses on the No. 10904 working face of Jingu Mine, where three distinct roof types are present: Type I (thick limestone roof, TLR, ≥1.2 m), Type II (moderate limestone roof, MLR, 0.5–1.2 m), and Type III (composite mudstone–limestone roof, CLR). Through FLAC3D numerical simulation and field validation, the mechanisms of bolt support under hard roof conditions were systematically investigated, and the optimization of bolt support parameters, including spacing, length, and pre-tension force, was conducted. The results indicate that: (1) when the ratio between lateral and row spacing approaches unity, reducing lateral spacing while increasing row spacing enhances support effectiveness, achieving 2 mm less roof subsidence with the 1.0 m × 1.5 m configuration compared to the 1.4 m × 0.8 m arrangement, despite a 21% reduction in bolt density; (2) an optimal rib bolt length of 1.8 m was determined, with support effectiveness diminishing beyond 2.0 m, and 1.5 m-long bolts reducing rib convergence by 15% compared to unsupported conditions; and (3) when the anchoring length exceeds 60% of the total bolt length, further increases in bolt length have minimal impact on deformation control under TLR, MLR, and CLR conditions. Field implementation of the optimized support scheme confirmed its effectiveness, with borehole television inspection showing no separation or fracturing within the monitored depth of 4 m in the roof strata. These findings provide practical guidelines for support design in similar geological settings, particularly for shallow-buried roadways with hard roof conditions. Full article
(This article belongs to the Section Separation Processes)
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15 pages, 7050 KiB  
Article
Formation and Surface Structures of Long-Range Ordered Self-Assembled Monolayers of 2-Mercaptopyrazine on Au(111)
by Dongjin Seo, Jin Wook Han, Hongki Kim, Yeon O Kim, Hyun Sun Sung, Riko Kaizu, Glenn Villena Latag, Tomohiro Hayashi, Nam-Suk Lee and Jaegeun Noh
Int. J. Mol. Sci. 2025, 26(1), 160; https://doi.org/10.3390/ijms26010160 - 27 Dec 2024
Cited by 1 | Viewed by 1025
Abstract
The effect of solution pH on the formation and surface structure of 2-pyrazinethiolate (2-PyzS) self-assembled monolayers (SAMs) formed by the adsorption of 2-mercaptopyrazine (2-PyzSH) on Au(111) was investigated using scanning tunneling microscopy (STM) and X-ray photoelectron microscopy (XPS). Molecular-scale STM observations clearly revealed [...] Read more.
The effect of solution pH on the formation and surface structure of 2-pyrazinethiolate (2-PyzS) self-assembled monolayers (SAMs) formed by the adsorption of 2-mercaptopyrazine (2-PyzSH) on Au(111) was investigated using scanning tunneling microscopy (STM) and X-ray photoelectron microscopy (XPS). Molecular-scale STM observations clearly revealed that 2-PyzS SAMs at pH 2 had a short-range ordered phase of (2√3 × √21)R30° structure with a standing-up adsorption structure. However, 2-PyzS SAMs at pH 8 had a very unique long-range ordered phase, showing a “ladder-like molecular arrangement” with bright repeating rows. This ordered phase was assigned to the (3 × √37)R43° structure, consisting of two different adsorption structures: standing-up and tilted adsorption structures. The average arial density of 2-PyzS SAMs on Au(111) at pH 8 was calculated to be 49.47 Å2/molecule, which is 1.52 times more loosely packed compared to the SAMs at pH 2 with 32.55 Å2/molecule. XPS measurements showed that 2-PyzS SAMs at pH 2 and pH 8 were mainly formed through chemical interactions between the sulfur anchoring group and the Au(111) substrates. The proposed structural models of packing structures for 2-PyzS SAMs on Au(111) at different pHs are well supported by the XPS results. The results of this study will provide new insights into the formation, surface structure, and molecular orientation of SAMs by N-heteroaromatic thiols with pyrazine molecular backbone on Au(111) at the molecular level. Full article
(This article belongs to the Section Biochemistry)
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21 pages, 16297 KiB  
Review
Silsesquioxanes as Promising Materials for the Development of Electrochemical (Bio)Sensors
by Felipe Zahrebelnei, Ariane Caroline Ribicki, Aline Martins Duboc Natal, Sérgio Toshio Fujiwara, Karen Wohnrath, Dhésmon Lima and Christiana Andrade Pessôa
Chemosensors 2024, 12(12), 259; https://doi.org/10.3390/chemosensors12120259 - 12 Dec 2024
Viewed by 1355
Abstract
Silsesquioxanes (SSQs) comprise an interesting and versatile class of three-dimensional organosilicate oligomers with diverse structural arrangements and interesting physicochemical properties. SSQs are of considerable technological interest, with applications that include the development of electrochemical detection devices. The presence of functional groups on their [...] Read more.
Silsesquioxanes (SSQs) comprise an interesting and versatile class of three-dimensional organosilicate oligomers with diverse structural arrangements and interesting physicochemical properties. SSQs are of considerable technological interest, with applications that include the development of electrochemical detection devices. The presence of functional groups on their structures enables the anchoring of different electroactive and conductive species, such as complexes, metal nanoparticles and carbon nanomaterials, and biomolecules, including enzymes, nucleic acids, and antibodies, which boosts the sensitivity and selectivity of the obtained (bio)sensors. These materials can also be incorporated into conductive matrices using a range of methods, which enhances their versatility. This mini review provides an overview of the most recent applications of hybrid organic–inorganic SSQs in the preparation of modified electrodes for the development of electrochemical sensors and biosensors. Special focus is placed on the incorporation of nanomaterials in their polymeric structure and on the design and fabrication of electrochemical devices using different strategies. Full article
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22 pages, 5018 KiB  
Article
Water Sorption on Isoreticular CPO-27-Type MOFs: From Discrete Sorption Sites to Water-Bridge-Mediated Pore Condensation
by Marvin Kloß, Lara Schäfers, Zhenyu Zhao, Christian Weinberger, Hans Egold and Michael Tiemann
Nanomaterials 2024, 14(22), 1791; https://doi.org/10.3390/nano14221791 - 7 Nov 2024
Cited by 1 | Viewed by 1447
Abstract
Pore engineering is commonly used to alter the properties of metal–organic frameworks. This is achieved by incorporating different linker molecules (L) into the structure, generating isoreticular frameworks. CPO-27, also named MOF-74, is a prototypical material for this approach, offering the potential [...] Read more.
Pore engineering is commonly used to alter the properties of metal–organic frameworks. This is achieved by incorporating different linker molecules (L) into the structure, generating isoreticular frameworks. CPO-27, also named MOF-74, is a prototypical material for this approach, offering the potential to modify the size of its one-dimensional pore channels and the hydrophobicity of pore walls using various linker ligands during synthesis. Thermal activation of these materials yields accessible open metal sites (i.e., under-coordinated metal centers) at the pore walls, thus acting as strong primary binding sites for guest molecules, including water. We study the effect of the pore size and linker hydrophobicity within a series of Ni2+-based isoreticular frameworks (i.e., Ni2L, L = dhtp, dhip, dondc, bpp, bpm, tpp), analyzing their water sorption behavior and the water interactions in the confined pore space. For this purpose, we apply water vapor sorption analysis and Fourier transform infrared spectroscopy. In addition, defect degrees of all compounds are determined by thermogravimetric analysis and solution 1H nuclear magnetic resonance spectroscopy. We find that larger defect degrees affect the preferential sorption sites in Ni2dhtp, while no such indication is found for the other materials in our study. Instead, strong evidence is found for the formation of water bridges/chains between coordinating water molecules, as previously observed for hydrophobic porous carbons and mesoporous silica. This suggests similar sorption energies for additional water molecules in materials with larger pore sizes after saturation of the primary binding sites, resulting in more bulk-like water arrangements. Consequently, the sorption mechanism is driven by classical pore condensation through H-bonding anchor sites instead of sorption at discrete sites. Full article
(This article belongs to the Special Issue Metal Organic Framework (MOF)-Based Micro/Nanoscale Materials)
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