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There is a growing need to develop artificial intelligence technologies capable of accurately predicting the properties of materials. This necessitates the expansion of material databases beyond the scope of density functional theory, and also the development of deep learning (DL) models that can be effectively trained with a limited amount of high-fidelity data. We developed a DL model utilizing a crystal structure representation based on the orbital field matrix (OFM), which was modified to incorporate information on elemental properties and valence electron configurations. This model, effectively capturing the interrelation between the elemental properties in the crystal, was coined the PRoperty-networking Orbital Field maTrix-convolutional neural Network (PROFiT-Net). Remarkably, PROFiT-Net demonstrated high accuracy in predicting the dielectric constant, experimental band gaps, and formation enthalpies compared with other leading DL models. Moreover, our model accurately identifies physical patterns, such as avoiding the prediction of unphysical negative band gaps and exhibiting a Penn-model-like trend while maintaining the scalability. We envision that PROFiT-Net will accelerate the development of functional materials.
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Due to their optimal bandgap size and large defect tolerance, nitrides are becoming pivotal materials in several optoelectronic devices, photovoltaics, and photocatalysts. A computational method that can accurately predict their electronic structures is indispensable for exploring new nitride materials. However, the relatively small bandgap of nitrides, which stems from the subtle balance between ionic and covalent bond characteristics, makes conventional density functional theory challenging to achieve satisfactory accuracy. Here, we employed a self-consistent hybrid functional where the Hartree-Fock mixing parameter is self-consistently determined and thus the empiricism of the hybrid functional is effectively removed to calculate the bandgaps of various nitride compounds. By comparing the bandgaps from the self-consistent hybrid functional calculations with the available experimental and high-level GW calculation results, we found that the self-consistent hybrid functional can provide a computationally efficient approach for quantitative predictions of nitride electronic structures with an accuracy level comparable to the GW method. Additionally, we aligned the band edge positions of various nitride compounds using self-consistent hybrid functional calculations, providing material design principles for heterostructures of nitride-based optoelectronic devices. We anticipate the wide use of the self-consistent hybrid functional for accelerating explorations and predictions of new nitride-based functional materials in various photoactive applications.
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Many studies have focused on tailoring the photophysical properties of two-dimensional (2D) materials for photocatalytic (PC) or photoelectrochemical (PEC) applications. To understand the optical properties of 2D materials in solution, we established a computational method that combined the Bethe-Salpeter equation (BSE) calculations with our GW-GPE method, allowing for GW/BSE-level calculations with implicit solvation described using the generalized Poisson equation (GPE). We applied this method to MoS2, phosphorene (PP), and g-C3N4 and found that when the solvent dielectric increased, it reduced the exciton binding energy and quasiparticle bandgap, resulting in almost no solvatochromic shift in the excitonic peaks of MoS2 and PP, which is consistent with previous experiments. However, our calculations predicted that the solvent dielectric had a significant impact on the excitonic properties of g-C3N4, exhibiting a large solvatochromic shift. We expect that our GW/BSE-GPE method will offer insights into the design of 2D materials for PC and PEC applications.
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Endovascular treatment is an acceptable option for patients with aortoiliac occlusive disease. However, bilateral passage of guidewires through the aortoiliac occlusion can be a challenging step in achieving successful revascularization. The aim of this article is to present a novel strategy for successfully passing bilateral guidewires through long aortoiliac occlusive lesions. After one guidewire is passed through the aortic and iliac lesions via one side of the femoral artery, the other guidewire is passed using the up-and-over technique and pulled out from the ipsilateral side of the body. This contralateral guidewire is then inserted into the ipsilateral angiographic catheter along with the ipsilateral guidewire. Subsequently, the angiographic catheter is removed in a manner similar to a peel-away sheath. Eventually, bilateral guidewires can be passed through the lesion via a single aortic tract.
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Conductive 2D nanosheets have evoked tremendous scientific efforts because of their high efficiency as hybridization matrices for improving diverse functionalities of nanostructured materials. To address the problems posed by previously reported conductive nanosheets like poorly-interacting graphene and cost-ineffective RuO2 nanosheets, economically feasible noble-metal-free conductive [MnxCo1-2xNix]O2 oxide nanosheets are synthesized with outstanding interfacial interaction capability. The surface-optimized [Mn1/4Co1/2Ni1/4]O2 nanosheets outperformed RuO2/graphene nanosheets as hybridization matrices in exploring high-performance visible-light-active (λ >420 nm) photocatalysts. The most efficient g-C3N4-[Mn1/4Co1/2Ni1/4]O2 nanohybrid exhibited unusually high photocatalytic activity (NH4 + formation rate: 1.2 mmol g-1 h-1), i.e., one of the highest N2 reduction efficiencies. The outstanding hybridization effect of the defective [Mn1/4Co1/2Ni1/4]O2 nanosheets is attributed to the optimization of surface bonding character and electronic structure, allowing for improved interfacial coordination bonding with g-C3N4 at the defect sites. Results from spectroscopic measurements and theoretical calculations reveal that hybridization helps optimize the bandgap energy, and improves charge separation, N2 adsorptivity, and surface reactivity. The universality of the [Mn1/4Co1/2Ni1/4]O2 nanosheet as versatile hybridization matrices is corroborated by the improvement in the electrocatalytic activity of hybridized Co-Fe-LDH as well as the photocatalytic hydrogen production ability of hybridized CdS.
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SnSe2 with its layered structure is a promising thermoelectric material with intrinsically low lattice thermal conductivity. However, its poor electronic transport properties have motivated extensive doping studies. Br doping effectively improves the power factor and converts the dimorphic SnSe2 to a fully hexagonal structure. To understand the mechanisms underlying the power factor improvement of Br-doped SnSe2, the electronic band parameters of Br-doped dimorphic and hexagonal SnSe2 should be evaluated separately. Using the single parabolic band model, we estimate the intrinsic mobility and effective mass of the Br-doped dimorphic and hexagonal SnSe2. While Br doping significantly improves the mobility of dimorphic SnSe2 (with the dominant hexagonal phase), it results in a combination of band convergence and band flattening in fully hexagonal SnSe2. Br-doped dimorphic SnSe2 is predicted to exhibit higher thermoelectric performance (zT â¼0.23 at 300 K) than Br-doped fully hexagonal SnSe2 (zT â¼0.19 at 300 K). Characterisation of the other, currently unidentified, structural phases of dimorphic SnSe2 will enable us to tailor the thermoelectric properties of Br-doped SnSe2.
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Proteorhodopsin (PR) is a light-driven proton pump that has been found in a variety of marine bacteria. Recently, many PR-like genes were found in non-marine environments. The goal of this study is to explore the function of rhodopsins that exist only as partial proteo-opsin genes using chimeras with marine green PR (GPR). We isolated nine partial genes of PR homologues using polymerase chain reaction (PCR) and chose three homologues of GPR from the surface of the Ganges River, which has earned them the name "CFR, Chimeric Freshwater Rhodopsin." In order to characterize the proteins, we constructed the cassette based on GPR sequence without helices C to F and inserted the isolated conserved partial sequences. When expressed in E. coli, we could observe light-driven proton pumping activity similar to proteorhodopsin, however, photocycle kinetics of CFRs are much slower than proteorhodopsin. Half-time decay of O intermediates of CFRs ranged between 143 and 333 ms at pH 10; their absorption maxima were between 515 and 522 nm at pH 7. We can guess that the function of native rhodopsin, a retinal protein of fresh water bacteria, may be a light-driven proton transport based on the results from chimeric freshwater rhodopsins. This approach will enable many labs that keep reporting partial PCR-based opsin sequences to finally characterize their proteins.
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Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Rodopsinas Microbianas/química , Rodopsinas Microbianas/metabolismo , Água Doce , Concentração de Íons de Hidrogênio , Proteínas de Membrana/genética , Bombas de Próton/química , Bombas de Próton/genética , Bombas de Próton/metabolismo , Proteínas Recombinantes de Fusão/genética , Rodopsina/química , Rodopsina/genética , Rodopsina/metabolismo , Rodopsinas Microbianas/genéticaRESUMO
Defect engineering provides an effective way to explore efficient nanostructured catalysts. Herein, we synthesize defect-regulated two-dimensional superlattices comprising interstratified holey g-C3N4 and TiO2 monolayers with tailorable interfacial coupling. Using this interfacial-coupling-controlled hybrid system, a strong interdependence among vacancy content, performance, and interfacial coupling was elucidated, offering key insights for the design of high-performance catalysts. The defect-optimized g-C3N4-TiO2 superlattice exhibited higher photocatalytic activity toward visible-light-induced N2 fixation (â¼1.06 mmol g-1 h-1) than defect-unoptimized and disorderly assembled g-C3N4-TiO2 homologues. The high photocatalytic performance of g-C3N4-TiO2 was attributed to the hybridization-induced defect creation, facilitated hydrogenation of adsorbed nitrogen, and improvement in N2 adsorption and charge transport. A comparison of the defect-dependent photocatalytic activity of g-C3N4, g-C3N4 nanosheets, and g-C3N4-TiO2 revealed the presence of optimal defect content for improving photocatalytic performance and the continuous increase of hybridization impact with the defect content. Sophisticated mutual influence among defect, electronic coupling, and photocatalytic ability underscores the importance of defect fine control in exploring high-performance hybrid photocatalysts. Along with the DFT calculation, the excellent photocatalyst performance of defect-optimized g-C3N4-TiO2 can be ascribed to the promotion of the uphill *N hydrogenation step as well as to enhancement of N2 adsorption, charge transfer kinetics, and mass transports.
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Computational simulations have become of major interest to screen potential photocatalysts for optimal band edge positions which straddle the redox potentials. Unfortunately, these methods suffer from a difficulty in resolving the dynamic solvent response on the band edge positions. We have developed a computational method based on the GW approximation coupled with an implicit solvation model that solves a generalized Poisson equation (GPE), that is, GW-GPE. Using GW-GPE, we have investigated the band edge locations of (quasi) 2D materials immersed in water and found a good agreement with experimental data. We identify two contributions of the solvent effect, termed a "polarization-field effect" and an "environmental screening effect", which are found to be highly sensitive to the atomic and charge distribution of the 2D materials. We believe that the GW-GPE scheme can pave the way to predict band edge positions in solvents, enabling design of 2D material-based photocatalysts and energy systems.
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The hybridization of conductive nanospecies has garnered significant research interest because of its high efficacy in improving the diverse functionalities of nanostructured materials. In this study, a novel synthetic strategy is developed to optimize the defect structure, structural ordering, and energy-related functionality of nanostructured-materials by employing a multilayer multicomponent two-dimenstional (2D) graphene/metal oxide/graphene nanosheet (NS) as a versatile hybridization matrix. The hybridization of the robust trilayer, polydiallyldiammonium (PDDA)-anchored reduced-graphene oxide (prGO)/metal oxide/prGO NS effectively enhance the structural ordering and porosity of the hybridized MoS2 /MnO2 NS through suppression of defect formation and tight stacking. In comparison with monolayer rGO/RuO2 NS-based homologs, the 2D superlattice trilayer prGO/RuO2 /prGO NS hybrids deliver better functionalities as a hydrogen evolution electrocatalyst and as a supercapacitor electrode, demonstrating the merits of hybridization with multilayer NSs. The advantages of using multilayer multicomponent conductive NSs as hybridization matrices arise from the enhancement of charge and mass transport through the layer flattening or defect suppression of the hybridized NSs and the increase in porosity, as evidenced by density functional theory calculations. Finally, the universal utility of multilayer NSs is confirmed by investigating the strong effect of the stacking order on the electrocatalytic functionality of MoS2 /rGO/RuO2 films fabricated through layer-by-layer deposition.
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'Ideal' transparent p-type semiconductors are required for the integration of high-performance thin-film transistors (TFTs) and circuits. Although CuI has recently attracted attention owing to its excellent opto-electrical properties, solution processability, and low-temperature synthesis, the uncontrolled copper vacancy generation and subsequent excessive hole doping hinder its use as a semiconductor material in TFT devices. In this study, we propose a doping approach through soft chemical solution process and transparent p-type Zn-doped CuI semiconductor for high-performance TFTs and circuits. The optimised TFTs annealed at 80 °C exhibit a high hole mobility of over 5 cm2 V-1 s-1 and high on/off current ratio of ~107 with good operational stability and reproducibility. The CuI:Zn semiconductors show intrinsic advantages for next-generation TFT applications and wider applications in optoelectronics and energy conversion/storage devices. This study paves the way for the realisation of transparent, flexible, and large-area integrated circuits combined with n-type metal-oxide semiconductor.
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Escherichia coli has been a primary host for the prokaryotic production of antibody fragments (Fabs) and has contributed to several successes in the pharmaceutical industry. Nevertheless, the requirement of disulfide bonds often results in low-yield fermentation and a lack of cost-effectiveness. Despite the improved production of functional Fabs by fermentation below 30⯰C, the limited cellular growth needs further work. To address these issues, we investigated the effect of nitrogen supply on the cellular growth and the Fab productivity. We used the anti-human VEGF-A Fab as a model that exhibited poor expression at 37⯰C regardless of the amount of nitrogen supplied during fermentation. In stark contrast, the expression yield of soluble Fab with a gross nitrogen supply of 6.91â¯g/L of broth throughout the fermentation at 25⯰C was 332â¯mg/L. Furthermore, and increased nitrogen supply of 10.9â¯g/L significantly improved the yield of active form by 59.7% and the cellular growth rate by 39.3%. These results indicate that overdosing of a nitrogen source at low temperature is critical to Fab productivity in E. coli.
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Escherichia coli/metabolismo , Fermentação , Fragmentos de Imunoglobulinas/imunologia , Nitrogênio/metabolismo , Temperatura Baixa , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/imunologia , Humanos , Fragmentos de Imunoglobulinas/genética , Fator A de Crescimento do Endotélio Vascular/imunologiaRESUMO
Chemical and physical agents can alter the structure of DNA by modifying the bases and the phosphate-sugar backbone, consequently compromising both replication and transcription. During transcription elongation, RNA polymerase complexes can stall at a damaged site in DNA and mark the lesion for repair by a subset of proteins that are utilized to execute nucleotide excision repair, a pathway commonly associated with the removal of bulky DNA damage from the genome. This RNA polymerase-induced repair pathway is called transcription-coupled nucleotide excision repair. Although our understanding of DNA lesion effects on transcription elongation and the associated effects of stalled transcription complexes on DNA repair is broadening, the attainment of critical data is somewhat impeded by labor-intensive, time- consuming processes that are required to prepare damaged DNA templates. Here, we describe an approach for building linear DNA templates that contain a single, site-specific DNA lesion and support transcription by human RNA polymerase II. The method is rapid, making use of biotin-avidin interactions and paramagnetic particles to purify the final product. Data are supplied demonstrating that these templates support transcription, and we emphasize the potential versatility of the protocol and compare it with other published methods.