Three-dimensional Structure Research Articles

Experimental Study of Electromagnetic Interference from Concentrated Discharge Channels within the Soil to Adjacent Directly Buried Cables during Lightning Current Inflow to the Ground

Independent lightning rods are often installed in substation grounding systems for lightning protection. The concentrated discharge channel formed when a lightning current flows to the ground through a grounding electrode will cause electromagnetic interference to the directly buried secondary cable. And the three-dimensional structure of the discharge channel will affect the transient electromagnetic field distribution, thereby affecting the electromagnetic transients on cable shields. In order to explore the influence of soil discharge phenomena on the electromagnetic interference of the directly buried secondary cable, in this paper, we carried out experiments on cables in two different grounding modes, single-ended and double-ended grounding, and captured image of soil discharge channels. The results show that the cable grounding mode will affect the coupling mode that causes the shielding layer current. The relative spatial position of the soil discharge channel and the cable has a significant impact on the magnitude of the shielding layer current under both grounding modes. The water content and salt content of the soil also have different degrees of influence on the coupling current of the shielding layer in different grounding modes.

Impact of the Three-Dimensional Arrangements of Polyhydroxylated Crosslinkers on the Resulting Properties of Chitosan-Based Hydrogels

Chitosan was subjected to a crosslinking reaction with three polyhydroxylated diacids (glucaric (GlcA), mannaric (ManA), and mucic (MucA) acids) that only differ in the spatial orientation of their hydroxyl groups. This work aimed to obtain experimental evidence of the impact of the three-dimensional arrangement of the crosslinkers on the resulting properties of the products. In all the cases, the products were hydrogels, and their chemical structures were fully elucidated by FT-IR spectroscopy and conductometric titration. Thermogravimetric and morphological studies were also carried out. The specific surface area of all the products was similar and higher than that of native chitosan. Moreover, all hydrogels were characterized in terms of viscoelastic properties and long-term stability under external perturbation. Furthermore, their lead adsorption efficiency and swelling capacity were assessed. Despite the resemblant chemical structure in all the hydrogels, Ch/ManA exhibited the highest lead adsorption capacity, (Ch/ManA: 93.8 mg g−1, Ch/GlcA: 82.9 mg g−1, Ch/MucA: 79.2 mg g−1), while Ch/GlcA exhibited a remarkably higher swelling capacity (i.e., ~30% more than Ch/MucA and ~40% more than Ch/ManA). The results obtained herein evidenced that the selection of the polyhydroxylated crosslinker with the appropriate three-dimensional structure could be crucial to finely adjust the final materials’ features.

Experimental and numerical investigation of heat sinks constructed by anisotropic 3-D Turing patterns

Heat dissipation is a critical issue for various engineering applications such as electronic devices, turbine blades and batteries. Existing heat sink structures contained inherent shortages in geometric flexibility which prevented further development of heat dissipation technologies. This study proposed a self-organized design method for heat sinks inspired by Turing Patterns (TP) in nature morphogenesis. The biomimetic structures were parametrically controlled with the aid of reaction-diffusion equations in terms of feature size, feature density, structural morphology and structural orientation. The metallic selective laser melting (SLM) technology was adopted to fabricate the three-dimensional (3-D) heat sinks. Experimental and numerical evaluations were conducted to compare TP structures with traditional pin-fin (PF) arrays baselines. Results showed substantial advantages of the TP structures in regulating flow field and enhancing height-wise fluid mixing. The thermal performance factor (TPF) of TP structures is approximately 45 % higher than traditional PF structures with similar feature sizes. The globally averaged magnitude of height-wise velocities of TP structure is around 2.4 times larger than that of PF structures due to the existence of the threshold-like and bridge-like structures. With the aid of three-dimensional structures, full utilization of the coolant was achieved to further increase the heat transfer intensity, while a high synergic level was formed within the flow field and temperature field to reduce the pressure drop. The design method proposed in this study demonstrated strong capability in tuning three-dimensional flow field and is expected to provide new insights to the heat transfer area that faces nonuniform thermal conditions and inhomogeneous flow conditions.

Self-Propagating Fabrication of a 3D Graphite@rGO Film Anode for High-performance Potassium-Ion Batteries.

Graphite, with abundant resources and low cost, is regarded as a promising anode material for potassium-ion batteries (PIBs). However, because of the large size of potassium ions, the intercalation/deintercalation of potassium between the interlayers of graphite results in its huge volume expansion, leading to poor cycling stability and rate performance. Herein, a self-propagating reduction strategy is adopted to fabricate a flexible, self-supporting 3D porous graphite@reduced graphene oxide (3D-G@rGO) composite film for PIBs. The 3D porous network can not only effectively mitigate the volume expansion in graphite but also provide numerous active sites for potassium storage as well as allow for electrolyte penetration and rapid ion migration. Therefore, compared to the pristine graphite anode, the flexible 3D-G@rGO film electrode exhibits greatly improved K-storage performance with a reversible capacity of 452.8 mAh g-1 at 0.1 C and a capacity retention rate of 80.4% after 100 cycles. It also presents excellent rate capability with a high specific capacity of 139.1 and 94.2 mAh g-1 maintained at 2 and 5 C, respectively. The proposed self-propagating reduction strategy to construct a three-dimensional self-supporting structure is a viable route to improve the structural stability and potassium storage performance of graphite anodes.

Therapeutic Application and Structural Features of Adeno-Associated Virus Vector

Adeno-associated virus (AAV) is characterized by non-pathogenicity, long-term infection, and broad tropism and is actively developed as a vector virus for gene therapy products. AAV is classified into more than 100 serotypes based on differences in the amino acid sequence of the capsid protein. Endocytosis involves the uptake of viral particles by AAV and accessory receptors during AAV infection. After entry into the cell, they are transported to the nucleus through the nuclear pore complex. AAVs mainly use proteoglycans as receptors to enter cells, but the types of sugar chains in proteoglycans that have binding ability are different. Therefore, it is necessary to properly evaluate the primary structure of receptor proteins, such as amino acid sequences and post-translational modifications, including glycosylation, and the higher-order structure of proteins, such as the folding of the entire capsid structure and the three-dimensional (3D) structure of functional domains, to ensure the efficacy and safety of biopharmaceuticals. To further enhance safety, it is necessary to further improve the efficiency of gene transfer into target cells, reduce the amount of vector administered, and prevent infection of non-target cells.

Vanadium as a Ti-like mediator boosting electronic transmission in Fe-based MOFs for photocatalytic sterilization

Efficient metal–organic frameworks (MOFs) photocatalytic bactericidal catalysts are urgently needed in water purification. Herein, a Fe-MOF (MIL-88B-NH2(V1Fe5) with promoted electron transport was achieved by vanadium (V) ions doping and V/Fe ratio optimization, showing excellent photocatalytic bactericidal activity against E. coli under visible light irradiation (99.92%). The efficient antibacterial mechanism, V as a Ti-like mediator boosting electronic transmission in MIL-88B-NH2(V1Fe5), was revealed by its band structure, transient photocurrent, electrochemical impedance spectroscopy, and scavenger quenching experiments. The enhancement of photocatalytic bactericidal performance of Fe-MOFs by V–ion-doping was confirmed by two other Fe-MOFs, MIL-53-NH2(V1Fe5) and MIL-101-NH2(V1Fe5), with the same metal ions and ligands, both of which have higher performance than the corresponding undoped MOFs. Among them, MIL-88B-NH2(V1Fe5) exhibits the highest photocatalytic bactericidal activity due to its suitable metal clusters ([M(μ 3-O)] cluster) and topological structure (three-dimensional rhomboid network structure). This work demonstrated the amplification effect of V ion doping on electron transport in Fe-MOFs photocatalysts.

Soul: An OCTA dataset based on Human Machine Collaborative Annotation Framework

Branch retinal vein occlusion (BRVO) is the most prevalent retinal vascular disease that constitutes a threat to vision due to increased venous pressure caused by venous effluent in the space, leading to impaired visual function. Optical Coherence Tomography Angiography (OCTA) is an innovative non-invasive technique that offers high-resolution three-dimensional structures of retinal blood vessels. Most publicly available datasets are collected from single visits with different patients, encompassing various eye diseases for distinct tasks and areas. Moreover, due to the intricate nature of eye structure, professional labeling not only relies on the expertise of doctors but also demands considerable time and effort. Therefore, we have developed a BRVO-focused dataset named Soul (Source of ocular vascular) and propose a human machine collaborative annotation framework (HMCAF) using scrambled retinal blood vessels data. Soul is categorized into 6 subsets based on injection frequency and follow-up duration. The dataset comprises original images, corresponding blood vessel labels, and clinical text information sheets which can be effectively utilized when combined with machine learning.

A novel variant in the keratin 12 gene in a four-generation Chinese family with high myopia.

High myopia is a major cause of visual impairment, and genetic factors play crucial roles in the pathogenesis. We performed this study to identify candidate genes for the development of high myopia in a four-generation Chinese family with myopia. All family members with myopia and 100 healthy participants were included in this study. Data were obtained on demographics, disease history, and ocular examination results. We performed whole exome sequencing of the genomic DNA and Sanger sequencing to verify the variants. Functional analyses of the variant were performed using software programmes. Nine of thirteen family members were found to have high myopia, amongst which two members were also diagnosed keratoconus. A missense variant in the keratin 12 gene (KRT12, p.Val410Gly) was detected in all high myopia cases but not in other family members without high myopia or the controls. The variant was predicted to be benign by online software programmes. However, modelling of the three-dimensional structure of the protein clearly revealed conformational changes caused by the mutation. A missense mutation in the KRT12 gene was identified in this Chinese family, which may be associated with the pathogenesis of high myopia.

Immunoinformatics design and synthesis of a multi-epitope vaccine against Helicobacter pylori based on lipid nanoparticles

Helicobacter pylori (H. pylori) is responsible for various chronic or acute diseases, such as stomach ulcers, dyspepsia, peptic ulcers, gastroesophageal reflux, gastritis, lymphoma, and stomach cancers. Although specific drugs are available to treat the bacterium's harmful effects, there is an urgent need to develop a preventive or therapeutic vaccine. Therefore, the current study aims to create a multi-epitope vaccine against H. pylori using lipid nanoparticles. Five epitopes from five target proteins of H. pylori, namely, Urease, CagA, HopE, SabA, and BabA, were used. Immunogenicity, MHC (Major Histocompatibility Complex) bonding, allergenicity, toxicity, physicochemical analysis, and global population coverage of the entire epitopes and final construct were carefully examined. The study involved using various bioinformatic web tools to accomplish the following tasks: modeling the three-dimensional structure of a set of epitopes and the final construct and docking them with Toll-Like Receptor 4 (TLR4). In the experimental phase, the final multi-epitope construct was synthesized using the solid phase method, and it was then enclosed in lipid nanoparticles. After synthesizing the construct, its loading, average size distribution, and nanoliposome shape were checked using Nanodrop at 280 nm, dynamic light scattering (DLS), and atomic force microscope (AFM). The designed vaccine has been confirmed to be non-toxic and anti-allergic. It can bind with different MHC alleles at a rate of 99.05%. The construct loading was determined to be about 91%, with an average size of 54 nm. Spherical shapes were also observed in the AFM images. Further laboratory tests are necessary to confirm the safety and immunogenicity of the multi-epitope vaccine.

PhAI: A deep-learning approach to solve the crystallographic phase problem.

X-ray crystallography provides a distinctive view on the three-dimensional structure of crystals. To reconstruct the electron density map, the complex structure factors [Formula: see text] of a sufficiently large number of diffracted reflections must be known. In a conventional experiment, only the amplitudes [Formula: see text] are obtained, and the phases ϕ are lost. This is the crystallographic phase problem. In this work, we show that a neural network, trained on millions of artificial structure data, can solve the phase problem at a resolution of only 2 angstroms, using only 10 to 20% of the data needed for direct methods. The network works in common space groups and for modest unit-cell dimensions and suggests that neural networks could be used to solve the phase problem in the general case for weakly scattering crystals.

A Novel Frameshift Mutation of HBB Causing Dominant β-Thalassemia in a Chinese Individual

We reported a rare β-thalassemia patient, a 41-year-old Chinese male with small cell hypopigmentation anemia, jaundice and splenomegaly as the main clinical symptoms. By using Next-Generation Sequencing (NGS), we identified a novel de novo HBB mutation(c.358_365dup, p.Phe123Alafs*39) which resulted in an abnormally prolonged β-globin chain comprising 159 amino acid residues. The secondary and three-dimensional structures of the β-globin predicted that the novel prolonged β-globin chain has a considerable risk of instability in the hemoglobin, and leads to clinical phenotype. This study contributes to the enrichment of the genetic pathogenic mutation database for thalassemia and underscores the significance of NGS in the screening of mutations for thalassemia families.

Preparation and sensing performance of wet-spun fabric triboelectric nanogenerator for energy harvesting

Flexible, wearable triboelectric nanogenerators (TENGs) monitoring human movement and health signals have received more attention recently. In particular, developing a flexible TENG combining stress, strain, electrical output performance and durability becomes the current research focus. Herein, a highly stretchable, self-powered coaxial yarn TENGs were manufactured using a low-cost, efficient continuous wet-spinning method. Carbon nanotube/conductive thermoplastic polyurethane (MWCNT/CTPU) and polyvinylidene fluoride-hexafluoropropylene were utilized for the coaxial fibers conductive layers and dielectric layers, respectively. Fibers were continuously collected over a length of 10 m. Excellent electrical output with an open-circuit voltage (Voc) of 11.4 V, short-circuit current (Isc) of 114.8 nA, and short-circuit transfer charge (Qsc) of 6.1 nC was achieved. In addition, fabric TENGs with different two and three dimensional structures were further prepared by the developed coaxial fibers. The corresponding electrical output properties and practical performance were discussed. Results showed that the four-layer three-dimensional angle interlocking structure exhibited the optimal performance with an open-circuit voltage (Voc) of 38.4 V, short-circuit current (Isc) of 451.5 nA, and short-circuit transfer charge (Qsc) of 23.1 nC.

Numerical investigation of a three-dimensional flow structure influenced by the lateral expansion of a partially distributed submerged canopy

This study employed numerical simulations to investigate the three-dimensional hydrodynamic structure of a channel obstructed by submerged rigid canopies. After validating the model using existing experimental data, a series of numerical experiments varying the canopy density and the blocking ratio were conducted. The results indicate that submerged canopy, different from emergent canopies, triggers the generation of three-dimensional coherent vortices. When canopies expand laterally, the scale, location, and evolution characteristics of cross-sectional secondary flows vary. The direction of secondary circulation at the canopy top of the fully covered vegetation channel is affected by the river width/depth ratio. Three-dimensional coherent vortices are jointly controlled by vertical and transverse Reynolds stresses. When the channel is seriously blocked, the degree of momentum exchange in the mixing layer does not change significantly. The boundary friction effect dominates the momentum exchange process near the wall. An equation coupling the drag length scale and blocking ratio with the vertical coherent vortex penetration length is proposed, indicating that the penetration length increases exponentially with both variables. Higher canopy density exhibits a stronger resistance to the vertical coherent vortex penetration length. In the process of canopy lateral expansion, the evolution time of the outer vortex to scale stability is longer than that of the inner vortex. The significance of research on the three-dimensional vortex structure of rigid submerged vegetation is established based on previous studies and existing conclusions.

Fluorescence detection of Al3+ and mechanism exploration based on La-MOF

Al is the most abundant metallic element, and plays an important role in the production of life. However, excessive accumulation of Al3+ in our bodies poses potential threats to our health. Therefore, highly effective detection of Al3+ has been an important issue. In this work, a new La-MOF with a three-dimensional structure (HNU-96) has been synthesized, which can serve as effective fluorescence sensor to Al3+ detection. Due to the ion exchange between La3+ and Al3+ and the weak interaction between Al3+ and O atoms, the fluorescence quenching of the La-MOF was observed. HNU-96 shows high selectivity for Al3+ detection with the limit of detection (LOD) as low as 2.3 x 10-6 M. Furthermore, HNU-96 shows excellent anti-interference for the Al3+ detection. This work provides the feasible strategy for the metal ion detection.

Artificial intelligence in fusion protein three-dimensional structure prediction: Review and perspective.

Recent advancements in artificial intelligence (AI) have accelerated the prediction of unknown protein structures. However, accurately predicting the three-dimensional (3D) structures of fusion proteins remains a difficult task because the current AI-based protein structure predictions are focused on the WT proteins rather than on the newly fused proteins in nature. Following the central dogma of biology, fusion proteins are translated from fusion transcripts, which are made by transcribing the fusion genes between two different loci through the chromosomal rearrangements in cancer. Accurately predicting the 3D structures of fusion proteins is important for understanding the functional roles and mechanisms of action of new chimeric proteins. However, predicting their 3D structure using a template-based model is challenging because known template structures are often unavailable in databases. Deep learning (DL) models that utilize multi-level protein information have revolutionized the prediction of protein 3D structures. In this review paper, we highlighted the latest advancements and ongoing challenges in predicting the 3D structure of fusion proteins using DL models. We aim to explore both the advantages and challenges of employing AlphaFold2, RoseTTAFold, tr-Rosetta and D-I-TASSER for modelling the 3D structures. HIGHLIGHTS: This review provides the overall pipeline and landscape of the prediction of the 3D structure of fusion protein. This review provides the factors that should be considered in predicting the 3D structures of fusion proteins using AI approaches in each step. This review highlights the latest advancements and ongoing challenges in predicting the 3D structure of fusion proteins using deep learning models. This review explores the advantages and challenges of employing AlphaFold2, RoseTTAFold, tr-Rosetta, and D-I-TASSER to model 3D structures.

Enhanced differentiation of mesenchymal stem cells in coral-incorporated PCL/elastin scaffold enables 3D defect healing in osteoporosis rat model

In osteoporosis, bone quality adversely affects the tissue structural competence which increases the risk of a complicated fracture healing. In the present study highly potent scaffold containing natural coral particles was designed and considered for the healing of critical size bone defect in osteoporosis rat model. Scaffold morphological evaluation confirmed the porous nanofibrous structure. Water uptake of about 900 % was obtained for the fabricated scaffold as the result of its composition and three-dimensional structure. Mechanical analysis revealed the compressive modulus of about 50 kPa for the fabricated coral-incorporated nanofibrous structure. In vitro cellular assessments revealed that the designed scaffold induces no toxicity and provides the proper substrate for cell attachment together with increased and prolonged cell proliferation. In vivo experiments demonstrated that implantation of the fabricated scaffold in the femoral defects of osteoporotic rats significantly increased the number of osteocytes and osteoblasts, and enhanced the BTV, and BMP-2 expression compared with the control group. Furthermore, it was observed that seeding the scaffolds with MSCs prior to implantation, resulted in substantial improvements in mRNA expression of the BMP-2 and VEGF genes and considerable enhancement in stereological findings such as significantly higher number of osteoblasts, osteocytes, TVB, and BTV.

Dihydromyricetin-loaded oxidized polysaccharide/L-arginine chitosan adhesive hydrogel promotes bone regeneration by regulating PI3K/AKT signaling pathway and MAPK signaling pathway

Bone defects caused by trauma, infection and congenital diseases still face great challenges. Dihydromyricetin (DHM) is a kind of flavone extracted from Ampelopsis grossedentata, a traditional Chinese medicine. DHM can enhance the osteogenic differentiation of human bone marrow mesenchymal stem cells with the potential to promote bone regeneration. Hydrogel can be used as a carrier of DHM to promote bone regeneration due to its unique biochemical characteristics and three-dimensional structure. In this study, oxidized phellinus igniarius polysaccharides (OP) and L-arginine chitosan (CA) are used to develop hydrogel. The pore size and gel strength of the hydrogel can be changed by adjusting the oxidation degree of oxidized phellinus igniarius polysaccharides. The addition of DHM further reduce the pore size of the hydrogel (213 μm), increase the mechanical properties of the hydrogel, and increase the antioxidant and antibacterial activities of the hydrogel. The scavenging rate of DPPH are 72.30 ± 0.33 %, and the inhibition rate of E.coli and S.aureus are 93.12 ± 0.38 % and 94.49 ± 1.57 %, respectively. In addition, PCAD has good adhesion and biocompatibility, and its extract can effectively promote the osteogenic differentiation of MC3T3-E1 cells. Network pharmacology and molecular docking show that the promoting effect of DHM on osteogenesis may be achieved by activating the PI3K/AKT and MAPK signaling pathways. This is confirmed through in vitro cell experiments and in vivo animal experiments.

Cyclodextrin Nanosponges: A Revolutionary Drug Delivery Strategy.

Nanosponges are porous solid cross-linked polymeric nanostructures. This study focuses on cyclodextrin-based nanosponges. Nanosponges based on cyclodextrin can form interactions with various lipophilic or hydrophilic compounds. The release of the entrapped molecules can be altered by altering the structure to obtain either a longer or faster release kinetics. The nanosponges might increase the aqueous solubility of weakly water-soluble compounds, develop long-lasting delivery systems, or construct novel drug carriers for nanomedicine. CD-NS (cyclodextrin-based nanosponges) are evolving as flexible and promising nanomaterials for medication administration, sensing, and environmental cleanup. CD-NS are three-dimensional porous structures of cyclodextrin molecules cross-linked by a suitable polymeric network, resulting in a large surface area. This overview covers CD-NS synthesis methods and applications.

Fabrication of water-resistant and abrasion- resistant superhydrophilic coatings

Superhydrophilic coatings show promising applications in the anti-fogging and self-cleaning fields. However, the application of transparent superhydrophilic coatings faces two challenges: abrasion and water immersion leading to loss of superhydrophilicity. Herein, we contribute Halloysite nanotubes (HNTs) to enhancing abrasion resistance by integrating into network-like structures within coatings, and water resistance by adsorbing sodium alkenyl sulfonate (AOS) facilitated by the positive charge within their cavities, respectively. Hydrolyzed tetraethyl orthosilicate (TEOS) as crosslinking agents combines with the abundant hydroxyl groups (Si-OH) on the surface of HNTs nanotubes and glass substrate to form a three-dimensional network structure. The results demonstrate that the designed HNTs tube coatings have strong abrasion and water resistance accompanied by anti-fogging and self-cleaning properties, which can withstand 800 cycles of Taber abrasion under a load of 250 g, and 90 min of immersion in boiling water. Furthermore, the coated surface exhibited negligible contamination after 153 days in an outdoor environment, which indicates a commendable long-term self-cleaning capability. Therefore, the introduction of HNTs nanotubes can provide a useful strategy for the development of superhydrophilic coatings for anti-fogging and self-cleaning with excellent abrasion and water resistance.

2,6-Diaminoanthraquinone modified MXene (Ti3C2Tx)/graphene as the negative electrode materials for ionic liquid-based asymmetric supercapacitors

Due to insufficient energy density, supercapacitors (SCs) with preeminent-power and long cycle stability cannot be implemented in some practical applications. Exploring hybrid materials with redox activity to emerge high specific capacitance in ionic liquid (IL) electrolytes can solve this problem. Herein, we report a redox-organic molecule 2,6-diaminoanthraquinone (DAAQ) modified MXene (Ti3C2Tx)/Graphene (DAAQ-M/G) composite material. With the assist of graphene oxide (GO), MXene and graphene fabricate a three-dimensional (3D) interconnected structure as a conductive framework, which inhibits self-stacking of MXene monolayers and ensures high electronic conductivity. Meanwhile, DAAQ is loaded onto the M/G framework through covalent/non-covalent functionalization. The DAAQ as a spacer effectively enlarges the interlayer spacing of MXene nanosheets, and meanwhile produces reversible redox reactions during charge/discharge processes to provide additional Faradaic contribution to capacity. Therefore, the specific capacitance (capacity) of the DAAQ-M/G as the negative electrode material reaches to 226 F g-1 (306 C g-1) at 1 A g-1 in 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF4) electrolyte. Furthermore, an asymmetric supercapacitor (ASC) is assembled using DAAQ-M/G as the negative electrode and self-prepared organic molecule hydroquinone modified reduced graphene oxide (HQ-RGO) material as the positive electrode, with a high energy density of 43 Wh kg-1 at high power density of 1669 W kg-1. The ASC can maintain 80% of initial specific capacitance after 9000 cycles. This research can provide better support to develop advanced organic molecules-modified MXene composite materials for ionic liquid-based SCs.