Assembly Method Research Articles

Polymersomes for Therapeutic Protein and Peptide Delivery: Towards Better Loading Properties.

Therapeutics based on proteins and peptides have profoundly transformed the landscape of treatment for diseases, from diabetes mellitus to cancers, yet the short half-life and low bioavailability of therapeutic proteins and peptides hinder their wide applications. To break through this bottleneck, biomolecules-loaded polymersomes with strong adjustability and versatility have attracted more and more attentions recently. Loading proteins or peptides into polymersomes is the first but extremely important step towards developing high-quality formulation products. However, increasing protein and peptide loading content is quite challenging due to the inherent nature of self-assembled vesicle formation mechanism and physiochemical characteristics of biomacromolecules. This review highlights the potential of polymersomes as the next-generation therapeutic proteins and peptides carrier and emphatically introduces novel approaches and recent progress to achieve satisfactory encapsulation capability of polymersomes for proteins and peptides. On the one hand, with the help of intermolecular interactions, such as electrostatic, lipid-protein, and hydrophobic interactions, the drug loading could be significantly improved. On the other hand, loading improvement could be attained through innovation of preparation methods, ranging from modified traditional film hydration techniques to the novel phase-guided assembly method.

Superspreading‐Confined Assembly of Oriented 2D MOF Membranes for Biomimetic Cation‐Regulated Ion Transport

AbstractInspired by biological channels, metal‐organic framework (MOF) membranes with sub‐nanometer sized channels offer an ideal platform to construct high‐performance artificial nanofluidic system. However, fabricating long‐range ordered MOF membranes is still a significant challenge. Herein, a superspreading‐confined assembly method is developed to prepare large‐scale oriented 2D MOF (Zn‐TCPP (TCPP = meso‐tetra(4‐carboxyphenyl) porphine)) membranes. The superspreading of reactant liquid under oil phase to form liquid layer plays a critical role in membrane formation, which provides a dynamic confined space for layered assembly of Zn‐TCPP nanosheets. Accompanied with solvent diffusion, such liquid layer is completely converted into <001>‐oriented MOF membrane with controlled thickness. The prepared membrane exhibits distinct divalent cation (Mx2+)‐regulated ion transport behavior as that demonstrated in biological channels: K+ flux can be precisely adjusted by anchoring diverse Mx2+ ions to binding sites, which is appealing in designing high‐performance nanofluidic iontronics. Moreover, similar strategies can be employed to fabricate other MOF membranes (such as Hf‐BTB (BTB = 1,3,5‐tris(4‐carboxyphenyl)benzene) and Ni‐TCPE (TCPE = tetrakis(4‐carboxyphenyl)ethylene)), indicating the broad applicability of this method in 2D membrane fabrication.

Active Dual-Protein Coating Assisted by Stepwise Protein-Protein Interactions Assembly Reduces Thrombosis and Infection.

Universal protein coatings have recently gained wide interest in medical applications due to their biocompatibility and ease of fabrication. However, the challenge persists in protein activity preservation, significantly complicating the functional design of these coatings. Herein, an active dual-protein surface engineering strategy assisted by a facile stepwise protein-protein interactions assembly (SPPIA) method for catheters to reduce clot formation and infection is proposed. This strategy is realized first by the partial oxidation of bovine serum albumin (BSA) and lysozyme (LZM) for creating stable nucleation platforms via hydrophobic interaction, followed by the assembly of nonoxidized BSA (pI, the isoelectric point, ≈4.7) and LZM (pI ≈11) through electrostatic interaction owing to their opposite charge under neutral conditions. The SPPIA method effectively preserves the conformation and functionality of both BSA and LZM, thus endowing the resultant coating with potent antithrombotic and bactericidal properties. Furthermore, the stable nucleation platform ensures the adhesion and durability of the coating, resisting thrombosis and bacterial proliferation even after 15 days of PBS immersion. Overall, the SPPIA approach not only provides a new strategy for the fabrication of active protein coatings but also shows promise for the surface engineering technology of catheters.

Heterogeneous lineage-specific arginine deiminase expression within dental microbiome species.

Tooth decay is the most common preventable chronic disease, affecting more than two billion people globally. The development of caries on teeth is primarily a consequence of acid production by cariogenic bacteria that inhabit the plaque microbiome. Other bacterial strains in the oral cavity may suppress or prevent tooth decay by producing ammonia as a byproduct of the arginine deiminase metabolic pathway, increasing the pH of the plaque biofilm. While the benefits of arginine metabolism on oral health have been extensively documented in specific bacterial groups, the prevalence and consistency of arginine deiminase system (ADS) activity among oral bacteria in a community context remain an open question. In the current study, we use a multi-omics approach to document the pervasiveness of the expression of the ADS operon in both health and disease to better understand the conditions in which ADS activity may prevent tooth decay.

Preparation of TiO2/Ni‐NG Mesoporous Microspheres and Photocatalytic Hydrogen Evolution Properties

AbstractThe regulation of surface active sites and structures is a key factor affecting the performance of photocatalysts. In order to prepare monodisperse anatase TiO2 mesoporous microspheres with higher specific surface area, smaller pore size and particle size, a dual‐surfactant orientation assembly method was selected. Graphene (NG) was selected as a cocatalyst to compound with mesoporous TiO2 and nickel doping was performed on the cocatalyst to improve the photocatalytic hydrogen production activity of the semiconductor photocatalyst. Through proper regulation and rational design, the semiconductor photocatalyst with desired properties was prepared. SEM characterization of mesoporous titanium dioxide (TiO2/Ni‐NG) with graphene cocatalyst proved that TiO2 nanospheres have good monodispersion, and TiO2 nanospheres are well supported on graphene cocatalyst. The composite material belonged to mesoporous group with the pore size being mainly distributed between 10–20 nm. The loading of graphene and Ni‐NG cocatalyst increased the absorption band edge by 9 nm and 38 nm, respectively, and the band gap decreased by 0.07 eV and 0.16 eV, respectively. The selection of graphene as cocatalyst improved the hydrogen production activity of photocatalyst and nickel doping was very effective in the modification of graphene. For reaction time of 2.5 h, the H2 production of TiO2/Ni‐NG material reached 1.767 mmol/g which was 7.27 times that of TiO2/NG composite material.

Layer-by-layer assembled graphitic carbon nitride membranes for water treatment

Meeting societal demand for potable water supply remains one of the prioritized challenges faced in the modern era. The anthropogenic intervention has led to a dire situation threatening ecological balance and human health. There is an inevitable need for the development of new technologies and innovations in existing technologies for water treatment. Photocatalytic Membrane technology, encompassing the merits of membrane filtration and photocatalytic degradation has evolved as a potential and reliable technology for sustainable water treatment. Innovations in photocatalytic materials and membrane fabrication techniques can lead to the goal of commercialization of membrane water treatment technology. Herein, we demonstrate the potential of graphitic carbon nitride (g-C3N4) and its functionalized analog as photocatalytic membranes for sustainable water treatment. g-C3N4 and Tetracarboxyphenylporphyrin sensitized g-C3N4 (g-C3N4/TCPP) was introduced onto commercial nylon membrane surface via a layer-by-layer (LBL) assembly method using chitosan and sodium salt of polystyrene sulphonic acid as polyelectrolytes. The fabricated membranes were characterized to ensure the integration of the photocatalysts. The performance of the membranes for water treatment was assessed by selecting some common dyes as model pollutants. The modified membranes exhibited excellent flux recovery and could afford high rejection rates upon irradiation indicating the prospects for sustainable filtration.

Advances in Nanoarchitectonics: A Review of "Static" and "Dynamic" Particle Assembly Methods.

Particle assembly is a promising technique to create functional materials and devices from nanoscale building blocks. However, the control of particle arrangement and orientation is challenging and requires careful design of the assembly methods and conditions. In this study, the static and dynamic methods of particle assembly are reviewed, focusing on their applications in biomaterial sciences. Static methods rely on the equilibrium interactions between particles and substrates, such as electrostatic, magnetic, or capillary forces. Dynamic methods can be associated with the application of external stimuli, such as electric fields, magnetic fields, light, or sound, to manipulate the particles in a non-equilibrium state. This study discusses the advantages and limitations of such methods as well as nanoarchitectonic principles that guide the formation of desired structures and functions. It also highlights some examples of biomaterials and devices that have been fabricated by particle assembly, such as biosensors, drug delivery systems, tissue engineering scaffolds, and artificial organs. It concludes by outlining the future challenges and opportunities of particle assembly for biomaterial sciences. This review stands as a crucial guide for scholars and professionals in the field, fostering further investigation and innovation. It also highlights the necessity for continuous research to refine these methodologies and devise more efficient techniques for nanomaterial synthesis. The potential ramifications on healthcare and technology are substantial, with implications for drug delivery systems, diagnostic tools, disease treatments, energy storage, environmental science, and electronics.

Deep learning-based augmented reality work instruction assistance system for complex manual assembly

The manual assembly process of complex products is lengthy, the assembly requirements are difficult to recall, and the assembly quality requirements are high. The separation of the operation guidance information from the real physical object in the traditional paper manual easily distracts the operator, increasing their cognitive burden. To address this issue, we integrate augmented reality (AR) and artificial intelligence (AI) technologies for manual assembly assistance. A novel encoding and decoding convolutional neural network (CNN) is built to realize accurate AR registration under mark-less assembly environment. An assembly quality inspection method integrating a neural network and virtual model matching was proposed for AR systems. The specific process of the proposed method includes two stages: offline and online. In the first stage, a monocular RGB image dataset was built for assembling object keypoints and assembly object detection. CNN models were designed and trained for deployment in an AR-assisted assembly system. Second, the deployed CNN models were used to perform AR registration and assembly quality inspection. Experimental results demonstrate that the proposed method can accurately present AR work instruction guidance and assembly quality inspection for manual assembly. The proposed AR registration method can achieve a frame rate of 25FPS, which satisfies the timeliness requirements of the AR system. The accuracy rate of the proposed assembly quality inspection method for the MONA component assembly reached 92.5%.

Genomic insights into an extensively drug-resistant and hypervirulent Burkholderia dolosa N149 isolate of a novel sequence type (ST2237) from a Vietnamese patient hospitalised for stroke

Burkholderia dolosa is a clinically important opportunistic pathogen in inpatients. Here we characterised an extensively drug-resistant and hypervirulent B. dolosa isolate from a patient hospitalised for stroke. Resistance to 41 antibiotics was tested with the agar disc diffusion, minimum inhibitory concentration, or broth microdilution method. The complete genome was assembled using short-reads and long-reads and the hybrid de novo assembly method. Allelic profiles obtained by multilocus sequence typing were analysed using the PubMLST database. Antibiotic-resistance and virulence genes were predicted in silico using public databases and the 'baargin' workflow. B. dolosa N149 phylogenetic relationships with all available B. dolosa strains and Burkholderia cepacia complex strains were analysed using the pangenome obtained with Roary. B. dolosa N149 displayed extensive resistance to 31 antibiotics and intermediate resistance to 4 antibiotics. The complete genome included three circular chromosomes (6 338 630 bp in total) and one plasmid (167 591 bp). Genotypic analysis revealed various gene clusters (acr, amr, amp, emr, ade, bla and tet) associated with resistance to 35 antibiotic classes. The major intrinsic resistance mechanisms were multidrug efflux pump alterations, inactivation and reduced permeability of targeted antibiotics. Moreover, 91 virulence genes (encoding proteins involved in adherence, formation of capsule, biofilm and colony, motility, phagocytosis inhibition, secretion systems, protease secretion, transmission and quorum sensing) were identified. B. dolosa N149 was assigned to a novel sequence type (ST2237) and formed a mono-phylogenetic clade separated from other B. dolosa strains. This study provided insights into the antimicrobial resistance and virulence mechanisms of B. dolosa.

The mitochondrial genome of Huaaristarchorum (Heude, 1889) (Gastropoda, Cerithioidea, Semisulcospiridae) and its phylogenetic implications.

Research on complete mitochondrial genomes can help in understanding the molecular evolution and phylogenetic relationships of various species. In this study, the complete mitogenome of Huaaristarchorum was characterized to supplement the limited mitogenomic information on the genus Hua. Three distinct assembly methods, GetOrganelle, NovoPlasty and SPAdes, were used to ensure reliable assembly. The 15,691 bp mitogenome contains 37 genes and an AT-rich region. Notably, the cytochrome c oxidase subunit I (COX1) gene, commonly used for species identification, appears to be slow-evolving and less variable, which may suggest the inclusion of rapidly evolving genes (NADH dehydrogenase subunit 6 [ND6] or NADH dehydrogenase subunit 2 [ND2]) as markers in diagnostic, detection, and population genetic studies of Cerithioidea. Moreover, we identified the unreliability of annotations (e.g., the absence of annotations for NADH dehydrogenase subunit 4L [ND4L] in NC_037771) and potential misidentifications (NC_023364) in public databases, which indicate that data from public databases should be manually curated in future research. Phylogenetic analyses of Cerithioidea based on different datasets generated identical trees using maximum likelihood and Bayesian inference methods. The results confirm that Semisulcospiridae is closely related to Pleuroceridae. The sequences of Semisulcospiridae clustered into three clades, of which H.aristarchorum is one; H.aristarchorum is sister to the other two clades. The findings of this study will contribute to a better understanding of the characteristics of the H.aristarchorum mitogenome and the phylogenetic relationships of Semisulcospiridae. The inclusion of further mitochondrial genome sequences will improve knowledge of the phylogeny and origin of Cerithioidea.

Experimental study on axial compression performance of unbonded prestressed mortise-tenon precast concrete mid joint

This paper presents an unbonded prestressed mortise-tenon precast concrete (MTPC) structure, where the beam-column joints are connected by mortise and tenon construction and are tightly crimped using longitudinal prestressed steel strand. It has the advantages of no wet works, easy on-site assembly, short construction period and can be disassembled. First, the structure and assembly method of MTPC joints were introduced. Five full-scale models of MTPC mid joints and one full-scale model of cast-in-place joint were produced. Then the axial compression test was carried out on these models. According to the test results, the damage mode and axial bearing capacity of the MTPC mid joint were analyzed. The analysis results show that the mortise and tenon construction of MTPC joint can effectively transfer the axial compression load, and its axial compression load bearing capacity is about 37%–46% of that of the cast-in-place joint. Unlike cast-in-place joint, there is an obvious compaction stage in MTPC joint under the axial compression. The damage of MTPC joint is concentrated in the beam-column joint area, and the main damage mode is short column damage. The weakest part of the joint is the lower column mortise, which is weakened by the small cross-sectional area and shear-compression force state. The MTPC joint is sensitive to the construction error and assembly error, which will cause the joint to be in eccentric force state and lead to the decrease of its bearing capacity. Finally, this paper proposes a method to calculate the axial compression bearing capacity of MTPC mid joint.

Controlled Preparation of High Quality Bubble-Free and Uniform Conducting Interfaces of Vertical van der Waals Heterostructures of Arrays.

Sharp and clean interfaces of van der Waals (vdW) heterostructures are highly demanded in two-dimensional (2D) materials-based devices. However, current assembly methods usually cause interfacial bubbles and wrinkles, hindering carrier interlayer transport. The preparation of a large-scale vdW heterostructure with a bubble-free interface is still a challenge. Although many efforts have been made to eliminate bubbles, the evolution processes of the interfacial bubbles are rarely studied. Here, the interface bubble formation and evolution of the transferred 2D materials and their vdW heterostructure are systemically studied by the atomic force microscopy (AFM) technique and high-resolution surface current mapping. A thermal annealing procedure is developed to reduce the number of bubbles and to improve the quality of interfaces. In addition, influences of the interface residues and nanosteps on bubble evolution are also discussed. Further, we develop the polystyrene (PS)-mediated polydimethylsiloxane (PDMS) transfer technique to realize the high-quality transfer of heterostructure arrays. Finally, high-resolution surface current mapping results confirm that we can now produce highly uniform electrical conduction interfaces of heterojunctions. This study provides guidance for assembling high quality interfaces and paves the way for production of bubble-free heterostructure-based electronic devices with high performance and good uniformity.

Highly Light-Harvesting MOF-on-MOF Heterostructure: Cascading Functionality to Flexible Photogating of Organic Photoelectrochemical Transistor and Bienzyme Cascade Detection.

Recently, organic photoelectrochemical transistor (OPECT) bioanalysis has become a prominent technique for the high-performance detection of biomolecules. However, as a sensitive index of the OPECT, the dynamic regulation transconductance (gm) is still severely deficient. Herein, this work reports a new photosensitive metal-organic framework (MOF-on-MOF) heterostructure for the effective modulation of maximum gm and natural bienzyme interfacing toward choline detection. Specifically, the bidentate ligand MOF (b-MOF) was assembled onto the UiO-66 MOF (u-MOF) by a modular assembly method, which could facilitate the charge separation and generate enhanced photocurrents and offer a biophilic environment for the immobilization of choline oxidase (ChOx) and horseradish peroxidase (HRP) through hydrogen-bonded bridges. The transconductance of the OPECT could be flexibly altered by increased light intensity to maximal value at zero gate bias, and sensitive choline detection was achieved with a detection limit of 0.2 μM. This work reveals the potential of MOF-on-MOF heterostructures for futuristic optobioelectronics.

Enantioselective sulfur(VI) fluoride exchange reaction of iminosulfur oxydifluorides.

Linkage chemistry and functional molecules derived from the stereogenic sulfur(VI) centre have important applications in organic synthesis, bioconjugation, drug discovery, agrochemicals and polymeric materials. However, existing approaches for the preparation of optically active S(VI)-centred compounds heavily rely on synthetic chiral S(IV) pools, and the reported linkers of S(VI) lack stereocontrol. A modular assembly method, involving sequential ligand exchange at the S(VI) centre with precise control of enantioselectivity, is appealing but remains elusive. Here we report an asymmetric three-dimensional sulfur(VI) fluoride exchange (3D-SuFEx) reaction based on thionyl tetrafluoride gas (SOF4). A key step involves the chiral ligand-induced enantioselective defluorinative substitution of iminosulfur oxydifluorides using organolithium reagents. The resulting optically active sulfonimidoyl fluorides allow for further stereospecific fluoride-exchange by various nucleophiles, thereby establishing a modular platform for the asymmetric SuFEx ligation and the divergent synthesis of optically active S(VI) functional molecules.

Investigation of a multistage adaptive test based on test assembly methods

In this research, multistage adaptive tests (MST) were compared according to sample size, panel pattern and module length for top-down and bottom-up test assembly methods. Within the scope of the research, data from PISA 2015 were used and simulation studies were conducted according to the parameters estimated from these data. Analysis results for each condition were compared in terms of mean RMSE and bias. According to the results obtained from the MST simulation based on the top-down test assembly method, mean RMSE values reduced when the module length increased and when the panel pattern changed from 1-2 to 1-2-2 and 1-2-3 for MST applied to small and large samples. Within the scope of the research, data from PISA 2015 were used and simulation studies were conducted using the parameters estimated from these data. Analysis results for each condition were compared in terms of mean RMSE and bias.

Effect of assembly method on the performance of Ce-Mn-Ti system in NH3-SCR

The components of the composite catalyst show different properties when they appear in different positions. The research on the assembly method of the composite catalyst is beneficial for exploring the potential of the catalyst. In this work, the Ce-Mn-Ti catalyst is prepared by different assembly methods. The results show that the catalyst with Ce-Mn co-doping has the best structure assembly mode, which is suitable for the denitration reaction of NH3-SCR. As a protective agent, Ce is doped into TiO2 to make the intermetallic interaction become more intense. Since doping Ce would cause lattice distortion and form short-range ordered bonds of Ce-O-Ti, thus reducing the pore size of catalyst and increasing the specific surface area of catalyst. At the same time, Ce also has excellent oxygen storage and oxygen release capacity, which can produce more oxygen vacancies. Mn is the active center, and doping into TiO2 can produce more Brønsted acid sites. Meanwhile Mn doping is beneficial to charge dispersion bond energy and optimize electron transport path. Ce-Mn co-doping can also enhance the interaction between metals. In this work three catalysts – CeMnTiO2, Ce/MnTiO2 and Mn/CeTiO2 were prepared, and the effects of doping and load modification methods on the active components were investigated.

One-dimensional assemblies of magnetic iron-oxide nanoparticles

Abstract Although high-aspect-ratio iron-oxide nanoparticles (IONPs) are known to have higher heating efficiency than spherical and cubic IONPs and focused in cancer treatment areas, their synthesis methods require high temperatures, vacuum, reduction conditions, and substantial time. In this study, we proposed and established a facile manufacturing method for one-dimensional assemblies of IONPs, expected to increase heating efficiency similar to high-aspect-ratio IONPs. We investigated how the fabrication conditions affect the length of the assemblies and found that the average length of the one-dimensional assemblies increased with the extension of magnetic-field-application time. This result demonstrates that the length could be controlled by adjusting the duration of the magnetic field application.

Dimension Evolution of Self-Assembled Organic Microcrystal for Laser and Polarization-Rotation Function.

Multidimensional integrated micro/nanostructures are vitally important for the implementation of versatile photonic functionalities, whereas current material structures still suffer undesired surface defects and contaminations in either multistep micro/nanofabrications or extreme synthetic conditions. Herein, the dimension evolution of organic self-assembled structures 2D microrings and 3D microhelixes for multidimensional photonic devices is realized via a protic/aprotic solvent-directed molecular assembly method based on a multiaxial confined-assisted growth mechanism. The 2D microrings with consummate circle boundaries and molecular-smooth surfaces function as high-quality whispering-gallery-mode microcavities for dual-wavelength energy-influence-dependent switchable lasing. Moreover, the 3D microhelixes with smooth surfaces and natural twistable characteristics act as active photon-transport materials and polarization rotators. These results will broaden the horizon of constructing multidimensional microstructures for integrated photonic circuits.

Design features of drilling equipment elements using materials with shape memory effect

Alloys exhibiting thermoelastic phase transformations are getting more and more used in different industries. This is due to the shape memory effect and pseudo-elasticity (sometimes termed “superelasticity”) they exhibit, which can considerably improve the performance characteristics of various technical systems. One of the highest reliability and durability criterias are applied to equipment for drilling oil and gas wells, and according to this the above-described smart materials and the phenomena they exhibit have been gradually implemented in the oil and gas industry. This article analyzes the developed design of roller cone bits elements and proposes its assembly method, and presents its comparison with currently existing designs. Computational research and computer analysis of a drilling equipment assembly containing parts made of shape memory materials were performed, these studies showed significant advantages of the proposed method.

Solusi Berkelanjutan untuk Perbaikan Kualitas Innerbox di PT. BKI Surabaya

Surabaya is the center of a growing manufacturing industry that always strives to improve the quality of its products. One company that faces serious problems is PT. BKI, which faces a high rate of innerbox defects with potential negative impact on product quality. The study used Six Sigma methodology to identify and address the root cause of innerbox defects within two months. The results of the analysis show that the main causes of innerbox defects include structuring, material, management, environmental problems, as well as improper assembly methods. The proposed solution involves the use of duplex-type cardboard materials, improved assembly techniques, regular machine maintenance, and environmental control. The use of stripping bands instead of duct tape on innerbox packaging is an effective improvement. The implementation of control for two months showed an increase in sigma value from 2.94 to 2.83. The Six Sigma approach is proven to provide a systematic analytical foundation for significant improvement. The results help PT. BKI in improving quality, efficiency, and customer satisfaction